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Sample records for adult optical penetrating

  1. Hermetic optical fiber penetrators for aquatic environments

    NASA Astrophysics Data System (ADS)

    Burke, Gregory C.

    1992-12-01

    The primary purpose of fiber optic penetrators is to provide a safe and reliable optical path through a hermetic barrier. The penetrators must resist pressure, humidity, corrosion, and maintain optical and mechanical integrity. Many optical fiber penetrators are manufactured from a combination of epoxies and application of a physical pressure seal onto the fiber. While providing a short term solution, epoxy lacks long term hermetic protection. Physical force applied to the fiber from a pressure seal may affect the refractive index of the optical cladding in soft and hard clad silica fibers. This presentation describes methods to provide a positive hermetic seal to a variety of optical fibers. These penetrators do not use lenses, prisms, or other conventional optical relay systems. Penetrators are intrinsically radiation hard and offer the convenience of providing a standard connector interface on one or both sides of the device. Examples of aquatic and high vacuum penetrators are presented. Application for this technology spans fiber geometry from single mode to large core step index fibers. Uses include communications and high energy transmission. This technology also is applicable to fiber based sensors.

  2. Optical penetration sensor for pulsed laser welding

    DOEpatents

    Essien, Marcelino; Keicher, David M.; Schlienger, M. Eric; Jellison, James L.

    2000-01-01

    An apparatus and method for determining the penetration of the weld pool created from pulsed laser welding and more particularly to an apparatus and method of utilizing an optical technique to monitor the weld vaporization plume velocity to determine the depth of penetration. A light source directs a beam through a vaporization plume above a weld pool, wherein the plume changes the intensity of the beam, allowing determination of the velocity of the plume. From the velocity of the plume, the depth of the weld is determined.

  3. Incomplete penetrance in mitochondrial optic neuropathies.

    PubMed

    Caporali, Leonardo; Maresca, Alessandra; Capristo, Mariantonietta; Del Dotto, Valentina; Tagliavini, Francesca; Valentino, Maria Lucia; La Morgia, Chiara; Carelli, Valerio

    2017-07-14

    Incomplete penetrance characterizes the two most frequent inherited optic neuropathies, Leber's Hereditary Optic Neuropathy (LHON) and dominant optic atrophy (DOA), due to genetic errors in the mitochondrial DNA (mtDNA) and the nuclear DNA (nDNA), respectively. For LHON, compelling evidence has accumulated on the complex interplay of mtDNA haplogroups and environmental interacting factors, whereas the nDNA remains essentially non informative. However, a compensatory mechanism of activated mitochondrial biogenesis and increased mtDNA copy number, possibly driven by a permissive nDNA background, is documented in LHON; when successful it maintains unaffected the mutation carriers, but in some individuals it might be hampered by tobacco smoking or other environmental factors, resulting in disease onset. In females, mitochondrial biogenesis is promoted and maintained within the compensatory range by estrogens, partially explaining the gender bias in LHON. Concerning DOA, none of the above mechanisms has been fully explored, thus mtDNA haplogroups, environmental factors such as tobacco and alcohol, and further nDNA variants may all participate as protective factors or, on the contrary, favor disease expression and severity. Next generation sequencing, complemented by transcriptomics and proteomics, may provide some answers in the next future, even if the multifactorial model that seems to apply to incomplete penetrance in mitochondrial optic neuropathies remains problematic, and careful stratification of patients will play a key role for data interpretation. The deep understanding of which factors impinge on incomplete penetrance may shed light on the pathogenic mechanisms leading to optic nerve atrophy, on their possible compensation and, thus, on development of therapeutic strategies. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Penetration and Splitting of Optic Nerve by Tuberculum Sellae Meningioma

    PubMed Central

    Park, Seong-Cheol

    2016-01-01

    Preservation of the optic nerves is an important issue in the resection of tuberculum sellae meningiomas. We report the case of a patient whose optic nerve was penetrated by a tuberculum sellae meningioma. During surgery, a bulging tumor was found to penetrate the right optic nerve. The tumor was gross totally removed, including tumors bulging through the optic nerve. Two trunks of the split optic nerve were preserved. The penetrated shape of the optic nerve may lead to misjudgment and its damage. Divided trunks of optic nerves are difficult to recognize and may be confused for the tumor capsule, because they may be thinned and seem to contain tumors. In addition, a single trunk may be confused for the whole nerve; thus, the other trunk may be easily damaged if not dissected cautiously. Treatment strategy according to the remnant visual acuity was suggested. PMID:27651874

  5. Optically modified fiber tips penetrate only when "dirty"

    NASA Astrophysics Data System (ADS)

    Verdaasdonck, Rudolf M.; Jansen, E. Duco; Holstege, F. C.; Borst, Cornelius

    1990-07-01

    Optically modified fiber tips are under investigation ox already in use clinically for the recanalization of totallyocciuded arteries. It has not been determined to what extent their mechanism of action is optical, thermal and mechanical. We studied a 2.2 mm diameter, rounded Sapphire Contact Probe (SLT, MTR 1.5) and a 1.5 mm diameter ball-shaped fiber (ACS) coupled to a continuous wave Nd-YAG laser using 1 second pulses. The probes were positioned perpendicular to homogeneous porcine fatty tissue samples in plasma using preset axial forces. Penetration depth per pulse and temperature of the collar of the probes were measured in relation to the force. Starting with new, clean probes no tissue penetration was achieved using forces up to the equivalent of 105 gr and powers up to 25 W for 10 s. On purpose, the probes where exposed to high powers in plasma until a coagulum was formed on the tip. After cleaning, a ring of carbonized particles deposited on the surface of the probe bordered the exit window of the beam on the tip. The power absorbed by the probes increased from 5 to 32 %. Tissue penetration with 'dirty' probes was force dependent. For sapphire contact probes it was 1.2 - 2.9 mm/pulse (1 mm diameter spot, 15 W, 1 s) in the force range of 23 - 105 gr. For the ball shaped fibers it was 2.7 10 mm/pulse (0.4 mm diameter spot, 10 W, 1 s) in force range of 23 - 35 gr. The optically modified fiber tips studied did not penetrate tissue by absorption of the Nd-YAG beam by the tissue only. Tissue penetration started when part of the laser beam was absorbed by pollution on the surface of the probe creating a 'hot tip'. Tissue penetration was force dependent due to the smaller diameter of the ablative beam in comparison to the diameter of the probe. Thus, the recanalization mechanism of both probes is partly mechanical.

  6. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    PubMed Central

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-01-01

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings. PMID:26229677

  7. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    SciTech Connect

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-15

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

  8. Neuroimaging in adult penetrating brain injury: a guide for radiographers.

    PubMed

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-01

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

  9. Optical penetration-based silkworm pupa gender sensor structure.

    PubMed

    Sumriddetchkajorn, Sarun; Kamtongdee, Chakkrit

    2012-02-01

    This paper proposes and experimentally demonstrates for what is believed to be the first time a highly sought-after optical structure for highly-accurate identification of the silkworm pupa gender. The key idea is to exploit a long wavelength optical beam in the red or near infrared spectrum that can effectively and safely penetrate the body of a silkworm pupa. Later on, simple image processing operations via image thresholding, blob filtering, and image inversion processes are applied in order to eliminate the unwanted image noises and at the same time highlight the gender gland. Experimental proof of concept using three 636 nm wavelength light emitting diodes, a two-dimensional web camera, an 8 bit microcontroller board, and a notebook computer shows a very high 95.6% total accuracy in identifying the gender of 45 silkworm pupae with a measured fast identification time of 96.6 ms. Other key features include low cost, low component counts, and ease of implementation and control.

  10. Penetration of the Optic Nerve and Falciform Ligament by an Internal Carotid Artery-Ophthalmic Artery Aneurysm: Case Reoport

    PubMed Central

    TAKAGI, Yasushi; MIYAMOTO, Susumu

    2014-01-01

    We report a case of an internal carotid artery (ICA)-ophthalmic artery aneurysm with penetration of the optic nerve. In addition, this case penetrated the falciform ligament, which severely disturbed optic canal unroofing during surgery. This is the first reported case in which penetration of the optic nerve and falciform ligament has been shown. To remove the anterior clinoid process in this case, the ultrasonic bone curette was a useful tool. PMID:24140766

  11. Penetration of an Optic Nerve by a Sellar/Suprasellar Arachnoid Cyst.

    PubMed

    Dawkins, Ross L; Hackney, James R; Riley, Kristen O

    2016-03-01

    Sellar/suprasellar cystic lesions can cause compression of the optic pathways and result in a decline in vision. There have been reports of optic pathways being fenestrated by intracranial aneurysms. This is the first report of a sellar/suprasellar arachnoid cyst causing fenestration of an optic nerve. Our patient presented with an 8-month history of worsening vision. Imaging revealed a sellar/suprasellar cystic lesion with compression of the optic pathways. He was treated surgically via an endoscopic transsphenoidal approach. The left optic nerve was found to have multiple round defects during surgery. Pathology was consistent with an arachnoid cyst. The patient has had progressive improvement in vision up to 6 months after surgery. Sellar/suprasellar arachnoid cysts likely form when a communication exists between the suprasellar arachnoid space and the sella turcica. We believe that our patient's cyst grew slowly enough to allow normal functioning of the optic nerve as it was being penetrated. Though visual symptoms may be gradual and not present until after the optic nerve has been penetrated, these symptoms and signs may still improve with removal of the cyst. Prognosis for visual improvement is difficult to predict with cases of compressive sellar/suprasellar cystic masses. Improvement in the vision examination after surgical resection is possible even when the optic nerve has been penetrated. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Penetrating radiation impact on NIF final optic components

    SciTech Connect

    Marshall, C.D.; Speth, J.A.; DeLoach, L.D.; Payne, S.A.

    1996-10-15

    Goal of the National Ignition Facility (NIF) is to achieve thermonuclear ignition in a laboratory environment in inertial confinement fusion (ICF). This will enable NIF to service the DOE stockpile stewardship management program, inertial fusion energy goals, and advance scientific frontiers. All of these applications will make use of the extreme conditions that the facility will create in the target chamber. In the case of a prospected 20 MJ yield scenario, NIF will produce 10{sup 19} neutrons with DT fusion 14 MeV energy per neutron. There will also be high-energy x rays as well as solid, liquid, and gaseous target debris produced either directly or indirectly by the inertial confinement fusion process. A critical design issue is the protection of the final optical components as well as sophisticated target diagnostics in such a harsh environment.

  13. Perioperative anaesthetic management of penetrating neck injury associated with Rh blood type in a young adult.

    PubMed

    Wang, Tao; Zhou, Yeting; Shi, Jiaohui; Wang, Zhichun

    2013-02-20

    We describe here a young adult patient with penetrating neck injuries (PNI) with an Rh negative blood type and discuss the perioperative anaesthetic management of single-stage surgical exploration under general anaesthesia and extracorporeal circulation in this patient. The patient had zone II PNI and he was in a haemodynamically progressive unstable state, and the knife penetrated the left internal jugular vein, superior thyroid artery and recurrent laryngeal nerve; the trachea and the oesophagus were swelling at a rapid rate. Eight weeks after operation, the patient was discharged from the hospital without any complications.

  14. Perioperative anaesthetic management of penetrating neck injury associated with Rh blood type in a young adult

    PubMed Central

    Wang, Tao; Zhou, Yeting; Shi, Jiaohui; Wang, Zhichun

    2013-01-01

    We describe here a young adult patient with penetrating neck injuries (PNI) with an Rh negative blood type and discuss the perioperative anaesthetic management of single-stage surgical exploration under general anaesthesia and extracorporeal circulation in this patient. The patient had zone II PNI and he was in a haemodynamically progressive unstable state, and the knife penetrated the left internal jugular vein, superior thyroid artery and recurrent laryngeal nerve; the trachea and the oesophagus were swelling at a rapid rate. Eight weeks after operation, the patient was discharged from the hospital without any complications. PMID:23429024

  15. Penetration and splitting of the optic apparatus by intrasaccular coils within an anterior communicating artery aneurysm.

    PubMed

    Lee, Seung Hwan; Koh, Jun Seok; Lee, Cheol Young; Kwon, Gi Young; Ryu, Chang Woo

    2011-09-01

    Penetration of the optic apparatus by an anterior communicating artery (ACoA) aneurysm is unique. A 43-year-old woman with a history of visual disturbance due to a previous aneurismal rupture underwent surgical neck clipping for a recurred ACoA aneurysm, which had previously been treated using detachable coils. The operation confirmed that the recurred aneurysm and the packed coils had penetrated the chiasm and the right optic nerve (ON), which was distorted and thinned. The aneurismal neck was clipped and the coils were left in place because damage to the optic apparatus by penetration is usually irreversible. As the patient was semicomatous at the former admission due to subarachnoid hemorrhage (SAH), she became aware of the visual disturbance 2 weeks after ictus when she had improved enough to communicate. The visual disturbance was found to have gradually improved at her 1-year follow-up. The absence of visual symptoms before the SAH and gradual visual improvement after coiling, even after recurrence due to coil compaction, were considered more compatible with a chronic compensated compressive, penetrating lesion of the ON. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Fiber optic microneedles for transdermal light delivery: ex vivo porcine skin penetration experiments.

    PubMed

    Kosoglu, Mehmet A; Hood, Robert L; Chen, Ye; Xu, Yong; Rylander, Marissa Nichole; Rylander, Christopher G

    2010-09-01

    Shallow light penetration in tissue has been a technical barrier to the development of light-based methods for in vivo diagnosis and treatment of epithelial carcinomas. This problem can potentially be solved by utilizing minimally invasive probes to deliver light directly to target areas. To develop this solution, fiber optic microneedles capable of delivering light for either imaging or therapy were manufactured by tapering step-index silica-based optical fibers employing a melt-drawing process. Some of the microneedles were manufactured to have sharper tips by changing the heat source during the melt-drawing process. All of the microneedles were individually inserted into ex vivo pig skin samples to demonstrate the feasibility of their application in human tissues. The force on each microneedle was measured during insertion in order to determine the effects of sharper tips on the peak force and the steadiness of the increase in force. Skin penetration experiments showed that sharp fiber optic microneedles that are 3 mm long penetrate through 2 mm of ex vivo pig skin specimens. These sharp microneedles had a minimum average diameter of 73 mum and a maximum tip diameter of 8 mum. Flat microneedles, which had larger tip diameters, required a minimum average diameter of 125 mum in order to penetrate through pig skin samples. Force versus displacement plots showed that a sharp tip on a fiber optic microneedle decreased the skin's resistance during insertion. Also, the force acting on a sharp microneedle increased more steadily compared with a microneedle with a flat tip. However, many of the sharp microneedles sustained damage during skin penetration. Two designs that did not accrue damage were identified and will provide a basis of more robust microneedles. Developing resilient microneedles with smaller diameters will lead to transformative, novel modes of transdermal imaging and treatment that are less invasive and less painful for the patient.

  17. Self-inflicted, trans-optic canal, intracranial penetrating injury with a ballpoint pen.

    PubMed

    Su, Yu-Min; Changchien, Chih-Hsuan

    2016-03-16

    Trans-orbital penetrating injuries are not common. If not promptly treated, these injuries can lead to serious disabilities and even death. A 60-year-old man, who had multiple underlying diseases, was admitted to our medical ward for the treatment of aspiration pneumonia; he attempted suicide by inserting a ballpoint pen into his left eye. CT of the brain showed a foreign body penetrating through the left optic canal into the intracranial parasellar region without obvious intracranial haemorrhage. The foreign body was withdrawn smoothly at bedside without a craniotomy. The patient was then transferred to the ICU for neuro-observation. The patient recovered with complete left ophthalmoplegia but intact visual function. Acute management of a trans-orbital penetrating injury involves prompt neuroimaging examinations and knowledge of common recurring patterns of injury. All clinicians should be aware of the psychological condition of each patient, and suicide precautions should be considered during clinical practice.

  18. Self-inflicted, trans-optic canal, intracranial penetrating injury with a ballpoint pen

    PubMed Central

    Su, Yu-Min; Changchien, Chih-Hsuan

    2016-01-01

    Trans-orbital penetrating injuries are not common. If not promptly treated, these injuries can lead to serious disabilities and even death. A 60-year-old man, who had multiple underlying diseases, was admitted to our medical ward for the treatment of aspiration pneumonia; he attempted suicide by inserting a ballpoint pen into his left eye. CT of the brain showed a foreign body penetrating through the left optic canal into the intracranial parasellar region without obvious intracranial haemorrhage. The foreign body was withdrawn smoothly at bedside without a craniotomy. The patient was then transferred to the ICU for neuro-observation. The patient recovered with complete left ophthalmoplegia but intact visual function. Acute management of a trans-orbital penetrating injury involves prompt neuroimaging examinations and knowledge of common recurring patterns of injury. All clinicians should be aware of the psychological condition of each patient, and suicide precautions should be considered during clinical practice. PMID:26984206

  19. A high performance fiber optic pressure penetrator for use in the deep ocean

    NASA Astrophysics Data System (ADS)

    Cowen, S. J.

    1981-02-01

    This report describes results obtained in an FY 80 developmental program carried out at the Naval Ocean System Center, San Diego, under Independent Exploratory Development funding. The objective was to develop a robust, fully-demountable, high pressure penetrator design suitable for coupling light signals transmitted by optical fiber elements in an undersea cable operated at high ambient hydrostatic pressure into an electronics package or manned space. The feasibility of constructing such penetrators utilizing Graded Refractive Index (GRIN) rod lenses as combination pressure barriers and imaging devices has been demonstrated. Prototype realizations have exhibited excellent optical throughput performance and readily survive in excess of 10,000 psi pressure differential as well as tolerating a wide temperature range. The design lends itself to hermetic construction for applications requiring no vapor diffusion over long mission durations. Such devices exhibit excellent potential for satisfying SUBSAFE requirements for manned submarine applications.

  20. Measurement of optical penetration depth and refractive index of human tissue

    NASA Astrophysics Data System (ADS)

    Xie, Shusen; Li, Hui; Li, Buhong

    2003-01-01

    Experimental techniques for measurement of optical penetration depth and refractive index of human tissue are presented, respectively. Optical penetration depth can be obtained from the measurement of the relative fluence-depth distribution inside the target tissue. The depth of normal and carcinomatous human lung tissues irradiated with the wavelengths of 406.7, 632.8 and 674.4 nm in vitro are respectively determined. In addition, a novel simple method based on total internal reflection for measuring the refractive index of biotissue in vivo is developed, and the refractive indices of skin from people of different age, sex and skin color are measured. Their refractive indices are almost same and the average is 1.533.

  1. Assessing the Penetrating Abilities of Experimental Preparation with Dental Infiltrant Features Using Optical Microscope: Preliminary Study.

    PubMed

    Skucha-Nowak, Małgorzata; Machorowska-Pieniążek, Agnieszka; Tanasiewicz, Marta

    2016-01-01

    The aim of the infiltration technique is to penetrate demineralized enamel with a low viscosity resin. Icon® (DMG) is the first ever and so far the only dental infiltrant. Bacteriostaticity is one of the properties that should be inherent in dental infiltrants, but Icon lacks this feature. The aim of the preliminary study was to properly choose a dye which would allow us to assess the penetrating abilities of our own, experimental preparation with features of a dental infiltrant with bacteriostatic properties and to compare using an optical microscope the depth of infiltration of the designed experimental preparation with the infiltrant available on the market. The preparation is supposed to infiltrate decalcified human enamel and be assessed with an optical microscope. Eosin, neutral fuchsine and methylene blue were added to experimental preparation with dental infiltrant features and to Icon® (DMG) in order to assess the depth of penetration of the experimental solution into the decalcified layers of enamel. The experimental solution mixes well with eosin, neutral fuchsine, and methylene blue. During the preliminary study, the authors concluded that the experimental solution mixes well with methylene blue, neutral fuchsine, and eosin. An addition of eosin to a preparation which infiltrates inner, demineralized enamel layers, facilitates the assessment of such a preparation with an optical microscope. A designed experimental solution with the main ingredients, i.e., 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethacrylate (TEGDMA) with a ratio of 75% to 25% penetrates the demineralized (decalcified) inner parts of the enamel and polymerizes when exposed to light. In order to assess the infiltration of the experimental solution into the demineralized enamel layers, it is required to improve the measurement techniques that utilize optical microscopy.

  2. Efficient mitochondrial biogenesis drives incomplete penetrance in Leber's hereditary optic neuropathy.

    PubMed

    Giordano, Carla; Iommarini, Luisa; Giordano, Luca; Maresca, Alessandra; Pisano, Annalinda; Valentino, Maria Lucia; Caporali, Leonardo; Liguori, Rocco; Deceglie, Stefania; Roberti, Marina; Fanelli, Francesca; Fracasso, Flavio; Ross-Cisneros, Fred N; D'Adamo, Pio; Hudson, Gavin; Pyle, Angela; Yu-Wai-Man, Patrick; Chinnery, Patrick F; Zeviani, Massimo; Salomao, Solange R; Berezovsky, Adriana; Belfort, Rubens; Ventura, Dora Fix; Moraes, Milton; Moraes Filho, Milton; Barboni, Piero; Sadun, Federico; De Negri, Annamaria; Sadun, Alfredo A; Tancredi, Andrea; Mancini, Massimiliano; d'Amati, Giulia; Loguercio Polosa, Paola; Cantatore, Palmiro; Carelli, Valerio

    2014-02-01

    Leber's hereditary optic neuropathy is a maternally inherited blinding disease caused as a result of homoplasmic point mutations in complex I subunit genes of mitochondrial DNA. It is characterized by incomplete penetrance, as only some mutation carriers become affected. Thus, the mitochondrial DNA mutation is necessary but not sufficient to cause optic neuropathy. Environmental triggers and genetic modifying factors have been considered to explain its variable penetrance. We measured the mitochondrial DNA copy number and mitochondrial mass indicators in blood cells from affected and carrier individuals, screening three large pedigrees and 39 independently collected smaller families with Leber's hereditary optic neuropathy, as well as muscle biopsies and cells isolated by laser capturing from post-mortem specimens of retina and optic nerves, the latter being the disease targets. We show that unaffected mutation carriers have a significantly higher mitochondrial DNA copy number and mitochondrial mass compared with their affected relatives and control individuals. Comparative studies of fibroblasts from affected, carriers and controls, under different paradigms of metabolic demand, show that carriers display the highest capacity for activating mitochondrial biogenesis. Therefore we postulate that the increased mitochondrial biogenesis in carriers may overcome some of the pathogenic effect of mitochondrial DNA mutations. Screening of a few selected genetic variants in candidate genes involved in mitochondrial biogenesis failed to reveal any significant association. Our study provides a valuable mechanism to explain variability of penetrance in Leber's hereditary optic neuropathy and clues for high throughput genetic screening to identify the nuclear modifying gene(s), opening an avenue to develop predictive genetic tests on disease risk and therapeutic strategies.

  3. Efficient Cargo Delivery into Adult Brain Tissue Using Short Cell-Penetrating Peptides

    PubMed Central

    Thomas, Alvin Kuriakose; Bhattarai, Prabesh; Zhang, Yixin; Brand, Michael

    2015-01-01

    Zebrafish brains can regenerate lost neurons upon neurogenic activity of the radial glial progenitor cells (RGCs) that reside at the ventricular region. Understanding the molecular events underlying this ability is of great interest for translational studies of regenerative medicine. Therefore, functional analyses of gene function in RGCs and neurons are essential. Using cerebroventricular microinjection (CVMI), RGCs can be targeted efficiently but the penetration capacity of the injected molecules reduces dramatically in deeper parts of the brain tissue, such as the parenchymal regions that contain the neurons. In this report, we tested the penetration efficiency of five known cell-penetrating peptides (CPPs) and identified two– polyR and Trans – that efficiently penetrate the brain tissue without overt toxicity in a dose-dependent manner as determined by TUNEL staining and L-Plastin immunohistochemistry. We also found that polyR peptide can help carry plasmid DNA several cell diameters into the brain tissue after a series of coupling reactions using DBCO-PEG4-maleimide-based Michael’s addition and azide-mediated copper-free click reaction. Combined with the advantages of CVMI, such as rapidness, reproducibility, and ability to be used in adult animals, CPPs improve the applicability of the CVMI technique to deeper parts of the central nervous system tissues. PMID:25894337

  4. Efficient Cargo Delivery into Adult Brain Tissue Using Short Cell-Penetrating Peptides.

    PubMed

    Kizil, Caghan; Iltzsche, Anne; Thomas, Alvin Kuriakose; Bhattarai, Prabesh; Zhang, Yixin; Brand, Michael

    2015-01-01

    Zebrafish brains can regenerate lost neurons upon neurogenic activity of the radial glial progenitor cells (RGCs) that reside at the ventricular region. Understanding the molecular events underlying this ability is of great interest for translational studies of regenerative medicine. Therefore, functional analyses of gene function in RGCs and neurons are essential. Using cerebroventricular microinjection (CVMI), RGCs can be targeted efficiently but the penetration capacity of the injected molecules reduces dramatically in deeper parts of the brain tissue, such as the parenchymal regions that contain the neurons. In this report, we tested the penetration efficiency of five known cell-penetrating peptides (CPPs) and identified two- polyR and Trans - that efficiently penetrate the brain tissue without overt toxicity in a dose-dependent manner as determined by TUNEL staining and L-Plastin immunohistochemistry. We also found that polyR peptide can help carry plasmid DNA several cell diameters into the brain tissue after a series of coupling reactions using DBCO-PEG4-maleimide-based Michael's addition and azide-mediated copper-free click reaction. Combined with the advantages of CVMI, such as rapidness, reproducibility, and ability to be used in adult animals, CPPs improve the applicability of the CVMI technique to deeper parts of the central nervous system tissues.

  5. Optical tweezers reveal relationship between microstructure and nanoparticle penetration of pulmonary mucus

    PubMed Central

    Kirch, Julian; Schneider, Andreas; Abou, Bérengère; Hopf, Alexander; Schaefer, Ulrich F.; Schneider, Marc; Schall, Christian; Wagner, Christian; Lehr, Claus-Michael

    2012-01-01

    In this study, the mobility of nanoparticles in mucus and similar hydrogels as model systems was assessed to elucidate the link between microscopic diffusion behavior and macroscopic penetration of such gels. Differences in particle adhesion to mucus components were strongly dependent on particle coating. Particles coated with 2 kDa PEG exhibited a decreased adhesion to mucus components, whereas chitosan strongly increased the adhesion. Despite such mucoinert properties of PEG, magnetic nanoparticles of both coatings did not penetrate through native respiratory mucus, resisting high magnetic forces (even for several hours). However, model hydrogels were, indeed, penetrated by both particles in dependency of particle coating, obeying the theory of particle mobility in an external force field. Comparison of penetration data with cryogenic scanning EM images of mucus and the applied model systems suggested particularly high rigidity of the mucin scaffold and a broad pore size distribution in mucus as reasons for the observed particle immobilization. Active probing of the rigidity of mucus and model gels with optical tweezers was used in this context to confirm such properties of mucus on the microscale, thus presenting the missing link between micro- and macroscopical observations. Because of high heterogeneity in the size of the voids and pores in mucus, on small scales, particle mobility will depend on adhesive or inert properties. However, particle translocation over distances larger than a few micrometers is restricted by highly rigid structures within the mucus mesh. PMID:23091027

  6. Preliminary lightning tests: Optical fiber penetration of an exclusion region barrier

    SciTech Connect

    Dinallo, M.A. ); Fisher, R.J. )

    1992-08-01

    As part of the Direct Optical Initiation (DOI) program, an assessment of the possibility of introducing lightning energy into an exclusion region via an Optical Barrier Feedthrough (OBF) is being carried out. One postulated penetration mechanism is the tracking of current past the OBF on the surface of the dielectric optical fiber itself. During September and October of 1991, a series of tests was conducted on a closed metallic cylindrical test object representing the electrical exclusion region of a weapon. Median-level (30-kA) and severe (200-kA) simulated lightning return strokes, singly, doubly, and in combination with a moderate continuing current, were attached directly to the exterior portion of a fiber optic cable, which penetrated through a hole of controlled size into the interior of the exclusion region. The thickness of the barrier surrounding the hole was 0.06 in. Attempts were made to measure any conducted current flowing on the fiber at distances of 1 and 4 inches from the interior surface of the stainless steel top of the cylinder. Test parameter variations included diameter of the penetration hole (475 and 500 microns), length of the exterior portion of the cable and whether or not its jacket was present, and the applied test currents. It is concluded that no signal above measurement noise was recorded on any of the data shots that made up the test series. Measurement resolution was of the order of several amperes. Based on the highest recorded response of 8.5 A, corresponding to a 200-kA input, the OBF can be characterized by a direct-strike lightning attenuation factor of approximately 5 {times} lO{sup {minus}5} or better. Based on the more typically observed noise level of a few amps, the attenuation is commensurately greater.

  7. Highly accurate and fast optical penetration-based silkworm gender separation system

    NASA Astrophysics Data System (ADS)

    Kamtongdee, Chakkrit; Sumriddetchkajorn, Sarun; Chanhorm, Sataporn

    2015-07-01

    Based on our research work in the last five years, this paper highlights our innovative optical sensing system that can identify and separate silkworm gender highly suitable for sericulture industry. The key idea relies on our proposed optical penetration concepts and once combined with simple image processing operations leads to high accuracy in identifying of silkworm gender. Inside the system, there are electronic and mechanical parts that assist in controlling the overall system operation, processing the optical signal, and separating the female from male silkworm pupae. With current system performance, we achieve a very highly accurate more than 95% in identifying gender of silkworm pupae with an average system operational speed of 30 silkworm pupae/minute. Three of our systems are already in operation at Thailand's Queen Sirikit Sericulture Centers.

  8. Optical pacing of the adult rabbit heart

    PubMed Central

    Jenkins, Michael W.; Wang, Y. T.; Doughman, Y. Q.; Watanabe, M.; Cheng, Y.; Rollins, A. M.

    2013-01-01

    Optical pacing has been demonstrated to be a viable alternative to electrical pacing in embryonic hearts. In this study, the feasibility of optically pacing an adult rabbit heart was explored. Hearts from adult New Zealand White rabbits (n = 9) were excised, cannulated and perfused on a modified Langendorff apparatus. Pulsed laser light (λ = 1851 nm) was directed to either the left or right atrium through a multimode optical fiber. An ECG signal from the left ventricle and a trigger pulse from the laser were recorded simultaneously to determine when capture was achieved. Successful optical pacing was demonstrated by obtaining pacing capture, stopping, then recapturing as well as by varying the pacing frequency. Stimulation thresholds measured at various pulse durations suggested that longer pulses (8 ms) had a lower energy capture threshold. To determine whether optical pacing caused damage, two hearts were perfused with 30 µM of propidium iodide and analyzed histologically. A small number of cells near the stimulation site had compromised cell membranes, which probably limited the time duration over which pacing was maintained. Here, short-term optical pacing (few minutes duration) is demonstrated in the adult rabbit heart for the first time. Future studies will be directed to optimize optical pacing parameters to decrease stimulation thresholds and may enable longer-term pacing. PMID:24049683

  9. Electrical stimulation with a penetrating optic nerve electrode array elicits visuotopic cortical responses in cats

    NASA Astrophysics Data System (ADS)

    Lu, Yiliang; Yan, Yan; Chai, Xinyu; Ren, Qiushi; Chen, Yao; Li, Liming

    2013-06-01

    Objective. A visual prosthesis based on penetrating electrode stimulation within the optic nerve (ON) is a potential way to restore partial functional vision for blind patients. We investigated the retinotopic organization of ON stimulation and its spatial resolution. Approach. A five-electrode array was inserted perpendicularly into the ON or a single electrode was advanced to different depths within the ON (˜1-2 mm behind the eyeball, 13 cats). A sparse noise method was used to map ON electrode position and the visual cortex. Cortical responses were recorded by a 5 × 6 array. The visuotopic correspondence between the retinotopic position of the ON electrode was compared with the visual evoked cortical map and the electrical evoked potentials elicited in response to ON stimulation. Main results. Electrical stimulation with penetrating ON electrodes elicited cortical responses in visuotopographically corresponding areas of the cortex. Stimulation of the temporal side of the ON elicited cortical responses corresponding to the central visual field. The visual field position shifted from the lower to central visual field as the electrode penetrated through the depth of the ON. A spatial resolution of ˜ 2° to 3° within a limited cortical visuotopic representation could be obtained by this approach. Significance. Visuotopic electrical stimulation with a relatively fine spatial resolution can be accomplished using penetrating electrodes implanted at multiple sites and at different depths within the ON just behind the globe. This study also provides useful experimental data for the design of electrode density and the distribution of penetrating ON electrodes for a visual prosthesis.

  10. A simulation of current focusing and steering with penetrating optic nerve electrodes

    NASA Astrophysics Data System (ADS)

    Li, Menghui; Yan, Yan; Wang, Qixin; Zhao, Honghong; Chai, Xinyu; Sui, Xiaohong; Ren, Qiushi; Li, Liming

    2013-12-01

    Objective. Current focusing and steering are both widely used to shape the electric field and increase the number of distinct perceptual channels in neural stimulation, yet neither technique has been used for an optic nerve (ON)-based visual prosthesis. In order to evaluate the effects of current focusing and steering in penetrative stimulation, we built an integrated computational model to simulate and investigate the influence of stimulating parameters on ON fibre recruitment. Approach. Finite element models with extremely fine meshes were first established to compute the 3D electric potential distribution under different stimulating parameters. Then the external electric potential was fed to randomized multi-compartment cable models to predict the distribution of fibres generating an action potential. Finally a statistical process was conducted to quantify the recruitment region. Main results. The simulation results show that a two-electrode mode is superior to a three-electrode mode in current steering. The three-electrode mode performs poorly in current focusing, albeit the localized recruitment from both configurations implies that current focusing might be unnecessary in penetrative ON stimulation. Significance. This study provides useful information for the optimized design of penetrating ON electrodes and stimulating strategies. The Monte Carlo style computation paradigm is designed to simulate neural responses of an ensemble of ON fibres, which can be immediately transferred to other similar problems.

  11. Electrically Evoked Responses in the Rabbit Cortex Induced by Current Steering With Penetrating Optic Nerve Electrodes.

    PubMed

    Yan, Yan; Lu, Yiliang; Li, Menghui; Ma, Zengguang; Cao, Pengjia; Chen, Yao; Sun, Xiaodong; Chai, Xinyu; Ren, Qiushi; Li, Liming

    2016-11-01

    Current steering is a neural stimulation strategy that uses simultaneous stimulation of adjacent electrodes to produce additional intermediate stimulation sites and thus improves spatial resolution. We investigated the feasibility of current steering using electrophysiological and computational methods after implanting paired penetrating electrodes into the rabbit's optic nerve (ON). Penetrating electrodes at different interelectrode distances were implanted into the ON and electrically evoked cortical potentials (EEPs) in V1 recorded with a 6 × 8 array. The current thresholds, EEP amplitudes, and spatial distributions were analyzed during current steering. Computational simulation studies were performed based on finite element models to calculate the area and spatial distribution of recruited ON fibers using a current steering stimulation strategy. Threshold reduction and EEP amplitude enhancement were found with simultaneous stimulation of closely spaced electrode pairs. Spatially shifted cortical responses were achieved using current steering, whereas the amplitudes and spatial spreads of the responses were similar to that elicited by a single electrode. Computational simulations suggested that the centroid of the ON recruitment area could be modulated by current steering while the total recruitment area did not show any appreciable variability at a fixed current intensity. Current steering is a useful strategy to enhance the spatial resolution of an ON prosthesis without increasing the number of physical electrodes. This study provides useful information for optimizing the design of stimulation strategies with a penetrating ON prosthesis.

  12. Optical coherence tomography using images of hair structure and dyes penetrating into the hair.

    PubMed

    Tsugita, Tetsuya; Iwai, Toshiaki

    2014-11-01

    Hair dyes are commonly evaluated by the appearance of the hair after dyeing. However, this approach cannot simultaneously assess how deep the dye has penetrated into hair. For simultaneous assessment of the appearance and the interior of hair, we developed a visible-range red, green, and blue (RGB) (three primary colors)-optical coherence tomography (OCT) using an RGB LED light source. We then evaluated a phantom model based on the assumption that the sample's absorbability in the vertical direction affects the tomographic imaging. Consistent with theory, our device showed higher resolution than conventional OCT with far-red light. In the experiment on the phantom model, we confirmed that the tomographic imaging is affected by absorbability unique to the sample. Furthermore, we verified that permeability can be estimated from this tomographic image. We also identified for the first time the relationship between penetration of the dye into hair and characteristics of wavelength by tomographic imaging of dyed hair. We successfully simultaneously assessed the appearance of dyed hair and inward penetration of the dye without preparing hair sections. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

    2010-07-01

    The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization.

  14. Mechanical analysis and fabrication of a penetrating silicon microprobe as an artificial optic nerve visual prosthesis.

    PubMed

    Sui, Xiaohong; Han, Zhaolong; Zhou, Dai; Ren, Qiushi

    2012-01-01

    To investigate the mechanical response of a silicon microprobe while it penetrates the optic nerve. The finite element method was adopted to analyze models of the mechanical aspects of the silicon microprobe, including the effects of dimensions, the buckling load, lateral load, and the interaction between the microprobe and the tissue of the optic nerve. The silicon microprobe was fabricated based on silicon-on-insulator (SOI) wafer by micro-electro-mechanical system (MEMS) processing techniques. The designed microprobe shank was 750 µm long and 110 µm wide with thickness of 15 µm. Lateral barbs were included so as to decrease the stress at stimulating-site regions. The microprobe could withstand a 50 MPa vertical load on the shank tip before buckling, but was more likely to be damaged by a lateral load rather than a vertical one. The silicon microprobe was successfully fabricated by MEMS processing techniques based on a four-inch SOI wafer. Mechanical analysis of the interactions between shank and optic nerve tissue showed that the maximum stress changed during the process of the microprobe insertion. A silicon microprobe was designed as a potential visual prosthesis to be used for optic nerve stimulation. The mechanical issues were analyzed by means of the finite element method, and the implantable microprobe was fabricated based on a silicon-on-insulator wafer to maintain a uniform thickness.

  15. Presence of infection influences the epithelial lining fluid penetration of oral levofloxacin in adult patients.

    PubMed

    Kuti, Joseph L; Nicolau, David P

    2015-05-01

    Although epithelial lining fluid (ELF) is the presumed site for pulmonary infections, most antibiotic penetration studies are conducted in uninfected patients or healthy volunteers. Levofloxacin concentrations in plasma and ELF were collected from two previous studies involving 18 infected patients with acute exacerbations of chronic bronchitis and 15 uninfected elderly patients undergoing diagnostic bronchoscopy. Concentration data were population modelled using the BigNPAG algorithm, and a 5000-patient Monte Carlo simulation was conducted to simulate ELF exposure for a dosing regimen 750mg every 24h for five doses in plasma and ELF of infected versus uninfected patients. Mean±S.D. model parameters for plasma in infected patients were similar to uninfected patients (volume of central compartment, 68.4±36.3 vs. 50.2±17.3L; clearance, 6.0±2.5 vs. 6.8±3.3L/h; and absorption rate, 5.4±2.5 vs. 4.7±2.7h(-1)), resulting in similar simulated AUC in plasma (infected, 140.5±54.8 vs. uninfected, 133.7±61.6μgh/mL). The volume of ELF was 57.2±25.0 and 14.8±9.0L in infected and uninfected patients, respectively, resulting in a lower simulated AUCELF exposure for infected patients (189.1±210.5 vs. 461.0±558.7μgh/mL). Penetration ratios for infected and uninfected patients were, respectively, 1.4±1.8 and 3.5±3.7, with median values of 0.9 and 2.4. ELF penetration in infected patients was approximately one-half that of uninfected adults. These data highlight the importance of confirming exposure in infected patients to further support dosage regimen selection.

  16. Investigation of multifocal choroiditis with panuveitis by three-dimensional high-penetration optical coherence tomography.

    PubMed

    Yasuno, Yoshiaki; Okamoto, Fumiki; Kawana, Keisuke; Yatagai, Toyohiko; Oshika, Tetsuro

    2009-07-01

    A single case of multifocal choroiditis with panuveitis (MFCPU) was investigated by a three-dimensional (3-D) high-penetration optical coherence tomography. The HP-OCT is based on a swept-source OCT technology, uses a probe beam with a center wavelength of 1060 nm, and possesses a depth resolution of 10.4 micromin tissue. Two eyes of an MFCPU patient were involved in this study. The eyes were also examined by color fundus photograph, fluorescein angiography (FA), and indocyanine green angiography (ICGA). Findings in these four modalities are comparatively discussed. The OCT scans revealed the following characteristic properties of the lesion sites. Thinning of the retina, destructuring of the retinal layers, and disappearance of the junction of the inner and outer segments of the photoreceptor (IS/OS). Due to the high penetration of this OCT system, the following characteristic properties of the lesions were also observed: localized thinning of the choroid, occlusion of the choroidal vessels, and localized hyper-reflectivity that may represent hyper-pigmentation of the choroid.

  17. Effects of wind speed on aerosol spray penetration in adult mosquito bioassay cages.

    PubMed

    Hoffmann, W Clint; Fritz, Bradley K; Farooq, Muhammad; Cooperband, Miriam F

    2008-09-01

    Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To correlate adult mortality readings to insecticidal efficacy and/or spray application parameters properly, it is important to know how the cage used in the bioassay interacts with the spray cloud containing the applied insecticide. This study compared the size of droplets, wind speed, and amount of spray material penetrating cages and outside of cages in a wind tunnel at different wind speeds. Two bioassay cages, Center for Medical, Agricultural and Veterinary Entomology (CMAVE) and Circle, were evaluated. The screen materials used on these cages reduced the size of droplets, wind speed, and amount of spray material inside the cages as compared to the spray cloud and wind velocity outside of the cages. When the wind speed in the dispersion tunnel was set at 0.6 m/sec (1.3 mph), the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.045 m/sec (0.10 mph) and 0.075 m/sec (0.17 mph), respectively. At air velocities of 2.2 m/sec (4.9 mph) in the dispersion tunnel, the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.83 m/sec (1.86 mph) and 0.71 m/sec (1.59 mph), respectively. Consequently, there was a consistent 50-70% reduction of spray material penetrating the cages compared to the spray cloud that approached the cages. These results provide a better understanding of the impact of wind speed, cage design, and construction on ultra-low-volume spray droplets.

  18. Magneto-optical studies of flux penetration in super-hard Nb wire

    NASA Astrophysics Data System (ADS)

    Young, D. P.; Moldovan, M.; Adams, P. W.; Prozorov, R.

    2005-05-01

    We present a study of the magnetic response of type-II superconductivity in the extreme pinning limit, where screening currents within an order of magnitude of the Ginzburg-Landau depairing critical current density develop upon the application of a magnetic field. We show that this 'super-hard' limit is realized in highly disordered, cold drawn, Nb wire whose magnetization response is characterized by a cascade of Meissner-like phases, each terminated by a catastrophic collapse of the magnetization. Direct magneto-optic measurements of the flux penetration depth in the virgin magnetization branch are in excellent agreement with the exponential model in which Jc(B) = Jcoexp(-B/B0), where Jco~5 × 106 A cm-2 for Nb. The implications for the fundamental limiting hardness of a superconductor are discussed.

  19. Anterior lamellar keratoplasty over penetrating keratoplasty for optical, therapeutic, and tectonic indications: a case series.

    PubMed

    Ang, Marcus; Mehta, Jodhbir S; Arundhati, Anshu; Tan, Donald T H

    2009-04-01

    To report a consecutive case series of patients who underwent anterior lamellar keratoplasty (ALK) over a preexisting penetrating keratoplasty (PK). Retrospective, interventional case series. Eight patients (8 eyes) were identified from the Singapore Corneal Transplant Study database, in a single institution (Singapore National Eye Center) from patients who underwent ALK performed over a PK. Main outcome measures were final visual acuity (VA), graft failure (ALK, PK or both), successful restoration of tectonic integrity in tectonic indications, and eradication of infection in therapeutic cases. The indications for surgery were therapeutic in 3 patients, optical in 3 patients, and tectonic in 2 patients. Postoperatively the best-corrected visual acuity (BCVA) improved in 5 eyes and remained unchanged in 3 eyes. Mean VA improved significantly after ALK; the mean preoperative BCVA was 1.52 +/- 0.25 and the mean postoperative BCVA was 0.87 +/- 0.26 (P = .032). Three of the 8 eyes post-lamellar keratoplasty (LK) managed to attain a BCVA equal to post-PK BCVA. Two patients had suture micro-perforations while 1 patient required a repeat ALK for recurrence of infection. ALK may be a considered as a viable alternative to a repeat PK for a variety of optical, therapeutic, and tectonic indications.

  20. Evaluation of the Central Corneal Thickness with Anterior Segment Optical Coherence Tomogram after Penetrating Keratoplasty

    PubMed Central

    Dhasmana, Renu; Bahadur, Harsh; Nagpal, Ramesh Chander

    2016-01-01

    Introduction Graft central thickness evaluates the graft quality which affects the outcome of Penetrating Keratoplasty (PK). It varies at different point of time after PK. Anterior Segment Optical Coherence Tomography (ASOCT) can measure graft’s central thickness with quite high precision. Aim The purpose of the study was to monitor the Central Corneal thickness (CCT) with ASOCT after PK and to evaluate its relationship with the pre-operative diagnosis. Materials and Methods This is an observational retrospective study where records of optical PK done in December 2012 and June 2015 were reviewed. Graft central thickness were analysed by ASOCT for all the patients post-operatively at first post-operative day, 3 and 6 months post PK by pachymetry scan and the images captured were analysed for CCT with inbuilt calipers. Results Fifty one eyes of 50 patients with age range of 17-80years (mean 51.64years ±SD 18.45 years) with clear grafts were reviewed in the present study. All subjects recruited were analysed for the indications of PK. Adherent leucoma 20(39.21%) was most common indication for PK. Mean CCT were 647.31±90.40, 605.31±75.08,564.66±66.26 and 537.37±64.09 respectively on first post-operative day, 1, 3 and 6 months. Graft CCT significantly decreased between first post-operative day and 1 month and it showed further decrease at 3 to 6 months post PK. The CCT at 6 month post-surgery showed a strongly positive correlation with the Intraocular Pressure (IOP) (r=0.66) and weakly positive correlation with Best Corrected Visual Acuity (BCVA) (r=0.28). Conclusion Graft central thickness is considered to be quantitative method for evaluating corneal oedema post PK. CCT decreases in post-operative period irrespective of indications of PK. PMID:27891366

  1. Optically-Activated GaAs Switches for Ground Penetrating Radar and Firing Set Applications

    SciTech Connect

    Aurand, J.; Brown, D.J.; Carin, L.; Denison, G.J.; Helgeson, W.D.; Loubriel, G.M.; Mar, A.; O'Malley, M.W.; Rinehart, L.F.; Zutavern, F.J.

    1999-07-14

    Optically activated, high gain GaAs switches are being tested for many different applications. TWO such applications are ground penetrating radar (GPR) and firing set switches. The ability of high gain GaAs Photoconductive Semiconductor Switches (PCSs) to deliver fast risetime pulses makes them suitable for their use in radars that rely on fast impulses. This type of direct time domain radar is uniquely suited for the detection of buried items because it can operate at low frequency, high average power, and close to the ground, greatly increasing power on target. We have demonstrated that a PCSs based system can be used to produce a bipolar waveform with a total duration of about 6 ns and with minimal ringing. Such a pulse is radiated and returns from a 55 gallon drum will be presented. For firing sets, the switch requirements include small size, high current, dc charging, radiation hardness and modest longevity. We have switched 1 kA at 1 kV and 2.8 kA at 3 kV dc charge.

  2. Towards next-generation time-domain diffuse optics for extreme depth penetration and sensitivity

    PubMed Central

    Mora, Alberto Dalla; Contini, Davide; Arridge, Simon; Martelli, Fabrizio; Tosi, Alberto; Boso, Gianluca; Farina, Andrea; Durduran, Turgut; Martinenghi, Edoardo; Torricelli, Alessandro; Pifferi, Antonio

    2015-01-01

    Light is a powerful tool to non-invasively probe highly scattering media for clinical applications ranging from oncology to neurology, but also for molecular imaging, and quality assessment of food, wood and pharmaceuticals. Here we show that, for a paradigmatic case of diffuse optical imaging, ideal yet realistic time-domain systems yield more than 2-fold higher depth penetration and many decades higher contrast as compared to ideal continuous-wave systems, by adopting a dense source-detector distribution with picosecond time-gating. Towards this aim, we demonstrate the first building block made of a source-detector pair directly embedded into the probe based on a pulsed Vertical-Cavity Surface-Emitting Laser (VCSEL) to allow parallelization for dense coverage, a Silicon Photomultiplier (SiPM) to maximize light harvesting, and a Single-Photon Avalanche Diode (SPAD) to demonstrate the time-gating capability on the basic SiPM element. This paves the way to a dramatic advancement in terms of increased performances, new high impact applications, and availability of devices with orders of magnitude reduction in size and cost for widespread use, including quantitative wearable imaging. PMID:26137377

  3. Stimulated penetrating keratoplasty using real-time virtual intraoperative surgical optical coherence tomography

    PubMed Central

    Lee, Changho; Kim, Kyungun; Han, Seunghoon; Kim, Sehui; Lee, Jun Hoon; Kim, Hong kyun; Kim, Chulhong; Jung, Woonggyu; Kim, Jeehyun

    2014-01-01

    Abstract. An intraoperative surgical microscope is an essential tool in a neuro- or ophthalmological surgical environment. Yet, it has an inherent limitation to classify subsurface information because it only provides the surface images. To compensate for and assist in this problem, combining the surgical microscope with optical coherence tomography (OCT) has been adapted. We developed a real-time virtual intraoperative surgical OCT (VISOCT) system by adapting a spectral-domain OCT scanner with a commercial surgical microscope. Thanks to our custom-made beam splitting and image display subsystems, the OCT images and microscopic images are simultaneously visualized through an ocular lens or the eyepiece of the microscope. This improvement helps surgeons to focus on the operation without distraction to view OCT images on another separate display. Moreover, displaying the OCT live images on the eyepiece helps surgeon’s depth perception during the surgeries. Finally, we successfully processed stimulated penetrating keratoplasty in live rabbits. We believe that these technical achievements are crucial to enhance the usability of the VISOCT system in a real surgical operating condition. PMID:24604471

  4. Penetration of Ceftaroline into the Epithelial Lining Fluid of Healthy Adult Subjects

    PubMed Central

    Pushkin, Richard; Jandourek, Alena; Knebel, William; Khariton, Tatiana

    2016-01-01

    Ceftaroline, the active metabolite of the prodrug ceftaroline fosamil, is a cephalosporin with bactericidal activity against Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to (i) evaluate ceftaroline concentrations in human plasma and epithelial lining fluid (ELF) and (ii) develop a population pharmacokinetic (PK) model for plasma and ELF to be used in PK/pharmacodynamic (PD) target attainment simulations. Ceftaroline concentrations in ELF and plasma at steady state (day 4) were measured in healthy adult subjects for two dosages: 600 mg every 12 h (q12h) and 600 mg every 8 h (q8h). Both were well tolerated with no serious adverse events. The penetration of free ceftaroline into ELF, assuming 20% protein binding in plasma and no protein binding in ELF, was ≈23%. The population PK model utilized a two-compartment model for both ceftaroline fosamil and ceftaroline. Goodness-of-fit criteria revealed the model was consistent with observed data and no systematic bias remained. At 600 mg q12h and a MIC of 1 mg/liter, 98.1% of simulated patients would be expected to achieve a target free drug concentration above the MIC (fT>MIC) in plasma of 42%, and in ELF 81.7% would be expected to achieve a target fT>MIC of 17%; at 600 mg q8h, 100% were predicted to achieve an fT>MIC in plasma of 42% and 94.7% to achieve an fT>MIC of 17% in ELF. The literature and data suggest the 600 mg q12h dose is adequate for MICs of ≤1 mg/liter. There is a need for clinical data in patients with MRSA pneumonia and data to correlate PK/PD relationships in ELF with clinical outcomes. PMID:27431215

  5. Penetration of Ceftaroline into the Epithelial Lining Fluid of Healthy Adult Subjects.

    PubMed

    Riccobene, Todd A; Pushkin, Richard; Jandourek, Alena; Knebel, William; Khariton, Tatiana

    2016-10-01

    Ceftaroline, the active metabolite of the prodrug ceftaroline fosamil, is a cephalosporin with bactericidal activity against Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to (i) evaluate ceftaroline concentrations in human plasma and epithelial lining fluid (ELF) and (ii) develop a population pharmacokinetic (PK) model for plasma and ELF to be used in PK/pharmacodynamic (PD) target attainment simulations. Ceftaroline concentrations in ELF and plasma at steady state (day 4) were measured in healthy adult subjects for two dosages: 600 mg every 12 h (q12h) and 600 mg every 8 h (q8h). Both were well tolerated with no serious adverse events. The penetration of free ceftaroline into ELF, assuming 20% protein binding in plasma and no protein binding in ELF, was ≈23%. The population PK model utilized a two-compartment model for both ceftaroline fosamil and ceftaroline. Goodness-of-fit criteria revealed the model was consistent with observed data and no systematic bias remained. At 600 mg q12h and a MIC of 1 mg/liter, 98.1% of simulated patients would be expected to achieve a target free drug concentration above the MIC (fT>MIC) in plasma of 42%, and in ELF 81.7% would be expected to achieve a target fT>MIC of 17%; at 600 mg q8h, 100% were predicted to achieve an fT>MIC in plasma of 42% and 94.7% to achieve an fT>MIC of 17% in ELF. The literature and data suggest the 600 mg q12h dose is adequate for MICs of ≤1 mg/liter. There is a need for clinical data in patients with MRSA pneumonia and data to correlate PK/PD relationships in ELF with clinical outcomes.

  6. In vivo and in vitro dermal penetration of 2,4,5,2 prime ,4 prime , 5 prime -hexachlorobiphenyl in young and adult rats

    SciTech Connect

    Shah, P.V.; Sumler, M.R. ); Fisher, H.L.; Hall, L.L. )

    1989-10-01

    Penetration of 2,4,5,2{prime},4{prime},5{prime}-({sup 14}C)hexachlorobiphenyl (HCB) through skin of young (33 days) and adult (82 days) female Fischer 344 rats was determined in vivo and by two in vitro methods. In vivo dermal penetration at 120 hr was 45% in young and 43% in adults. At 72 hr in vivo dermal penetration was 35% in young and 26% in adults compared to 1.5% for young and 1.0% for adult as measured with a continuous flow in vitro system and 2.9% for young and 1.9% for adults as measured with a static in vitro system. Most of the dermally absorbed HCB remained in the body as only 4.9 and 2.6% of that absorbed was excreted by young and adult rats, respectively, at the end of 120 hr. Significant differences in dermal penetration and kinetics of HCB between young and adult female rats were observed. The elimination of ECB-derived material was approximately six times higher in feces than in urine. A physiological pharmacokinetic model was fitted to the organ and tissue radioactivity distribution data. Parameters in the model determined from dermal dosing of female Fischer 344 rats were in reasonable agreement with those reported in the literature for adult male Sprague-Dawley rats (iv dose). The rate constant for dermal penetration was 0.83 {times} 10{sup {minus}4} min{sup {minus}1} for adults and 0.96 {times} 10{sup {minus}4} min{sup {minus}1} for young. The delay or lag time parameter for dermal penetration was 4.4 hr in adults and 1.1 hr in young.

  7. Monte Carlo model of the penetration depth for polarization gating spectroscopy: influence of illumination-collection geometry and sample optical properties

    PubMed Central

    Gomes, Andrew J.; Turzhitsky, Vladimir; Ruderman, Sarah; Backman, Vadim

    2013-01-01

    Polarization-gating has been widely used to probe superficial tissue structures, but the penetration depth properties of this method have not been completely elucidated. This study employs a polarization-sensitive Monte Carlo method to characterize the penetration depth statistics of polarization-gating. The analysis demonstrates that the penetration depth depends on both the illumination-collection geometry [illumination-collection area (R) and collection angle (θc)] and on the optical properties of the sample, which include the scattering coefficient (μs), absorption coefficient (μa), anisotropy factor (g), and the type of the phase function. We develop a mathematical expression relating the average penetration depth to the illumination-collection beam properties and optical properties of the medium. Finally, we quantify the sensitivity of the average penetration depth to changes in optical properties for different geometries of illumination and collection. The penetration depth model derived in this study can be applied to optimizing application-specific fiber-optic probes to target a sampling depth of interest with minimal sensitivity to the optical properties of the sample. PMID:22781238

  8. Coupling Ocean Models and Satellite Derived Optical Fields to Estimate LIDAR Penetration and Detection Performance

    DTIC Science & Technology

    2012-01-01

    eutrophic waters, which are dominated by seasonal blooms and river fluxes, specifically, runoff from the Mississippi River. Neglecting any...the majority of the Gulf domain. The higher the Kd values (i.e. eutrophic waters), the shallower the penetration of a laser. Similarly, lower Kd

  9. Sub-40 fs, 1060-nm Yb-fiber laser enhances penetration depth in nonlinear optical microscopy of human skin

    NASA Astrophysics Data System (ADS)

    Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

    2015-12-01

    Advancing the practical utility of nonlinear optical microscopy requires continued improvement in imaging depth and contrast. We evaluated second-harmonic generation (SHG) and third-harmonic generation images from ex vivo human skin and showed that a sub-40 fs, 1060-nm Yb-fiber laser can enhance SHG penetration depth by up to 80% compared to a >100 fs, 800 nm Ti:sapphire source. These results demonstrate the potential of fiber-based laser systems to address a key performance limitation related to nonlinear optical microscopy (NLOM) technology while providing a low-barrier-to-access alternative to Ti:sapphire sources that could help accelerate the movement of NLOM into clinical practice.

  10. Investigation on penetration of three conventional foodstuffs packaging polymers with two different thicknesses by larvae and adults of major species of stored-product pest insects.

    PubMed

    Allahvaisi, Somayeh; Purmirza, Ali Asghar; Safaralizade, Mohamad Hasan

    2009-01-01

    Despite modern methods of packaging, stored agricultural products are still under attack by stored-insect pests. Therefore, determination of the best polymer and appropriate thickness inhibiting the penetration of the insects must be considered. In this study, we investigated the ability of penetration and the rates of contamination by nine important stored product pest insects for three conventional flexible polymers (polyethylene, cellophane and polypropylene) at two thicknesses (16.5 and 29 microm), which are used as pouches for packing of agricultural products. We used adults of T. castaneum (Coleoptera), S. granarius (Coleoptera), R. dominica (Coleoptera), C. maculates (Coleoptera), O. surinamensis (Coleoptera), and larvae of P. interpunctella (Lepidoptera), E. kuehniella (Lepidoptera), S. cerealella (Lepidoptera) and T. granarium (Coleoptera). Results showed that for most of the species penetration occurred between 4 days and 2 weeks, but there were significant differences (p < or = 0.05) in the penetration of three polymers (cellophane, polyethylene and polypropylene) by the insects. Among the polymers, polyethylene with a thickness of 16.5 microm showed the highest degree of penetration and was the most unsuitable polymer for packaging of foodstuffs. Application of this polymer led to a complete infestation of the product and a lot of punctures were created by the insects. In contrast, no penetration was observed in polypropylene polymer with a thickness of 29 microm. Furthermore, adults and larvae of all species showed a much lower penetration when there was no food present in the pouches and this was the case for all polymers tested.

  11. Optical topographic studies of adults and neonates

    NASA Astrophysics Data System (ADS)

    Nissila, Ilkka T.; Kotilahti, Kalle; Noponen, Tommi E.; Huotilainen, Minna; Naatanen, Risto; Katila, Toivo E.

    2003-07-01

    We used a four-channel intensity-modulated near-infrared spectroscopy device to study the hemodynamic responses due to brain activation in adults and neonates. The stimuli included finger tapping, tickling of the heel, and auditory stimuli. The subjects included two adults and ten neonates of age between 0.5 and 4 days. A block paradigm was used in the studies, and responses were successfully obtained from both subject groups.

  12. Calculation of optical properties of dental composites as a basis for determining color impression and penetration depth of laser light

    NASA Astrophysics Data System (ADS)

    Weniger, Kirsten K.; Muller, Gerhard J.

    2005-03-01

    In order to achieve esthetic dental restorations, there should be no visible difference between restorative material and treated teeth. This requires a match of the optical properties of both restorative material and natural teeth. These optical properties are determined by absorption and scattering of light emerging not only on the surface but also inside the material. Investigating different dental composites in several shades, a method has been developed to calculate the optical parameters absorption coefficient μa, scattering coefficient μs, anisotropy factor g and reduced scattering coefficient μs'. The method includes sample preparation and measurements of transmittance and reflectance in an integrating sphere spectrometer, followed by inverse Monte Carlo simulations. Determination of optical properties is more precise and comprehensive than with the previously used Kubelka Munk theory because scattering can be looked at separated into pure scattering with the scattering coefficient μs and its direction with the anisotropy factor g. Moreover the use of the inverse Monte Carlo simulation not only minimizes systematic errors and considers the scattering phase function, but also takes into account the measuring geometry. The compilation of a data pool of optical parameters now enables the application of further calculation models as a basis for optimization of the composition of new materials. For example, a prediction of the general color impression for multiple layers can be carried out as well as the calculation of the wavelength dependent penetration depths of light with regard to photo polymerization. Further applications are possible in the area of laser ablation.

  13. Quantifying glucose permeability and enhanced light penetration in ex vivo human normal and cancerous esophagus tissues with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Zhao, Q. L.; Si, J. L.; Guo, Z. Y.; Wei, H. J.; Yang, H. Q.; Wu, G. Y.; Xie, S. S.; Li, X. Y.; Guo, X.; Zhong, H. Q.; Li, L. Q.

    2011-01-01

    We report our pilot results on quantification of glucose (G) diffusion permeability in human normal esophagus and ESCC tissues in vitro by using OCT technique. The permeability coefficient of 40% aqueous solution of G was found to be (1.74±0.04)×10-5 cm/s in normal esophagus and (2.45±0.06)×10-5 cm/s in ESCC tissues. The results from this study indicate that ESCC tissues had a higher permeability coefficient compared to normal esophageal tissues, and the light penetration depths gradually increase with the increase of applied topically with G time for the normal esophageal and ESCC tissues. The results indicate that the permeability coefficient of G in cancer tissues was 1.41-fold than that in normal tissues, and the light penetration depth for the ESCC tissues is significantly smaller than that of normal esophagus tissues in the same time range. These results demonstrate that the optical clearing of normal and cancer esophagus tissues are improved after application of G.

  14. Analysis of hydrofluoric acid penetration and decontamination of the eye by means of time-resolved optical coherence tomography.

    PubMed

    Spöler, Felix; Frentz, Markus; Först, Michael; Kurz, Heinrich; Schrage, Norbert F

    2008-06-01

    So far the study of chemical burns has lacked techniques to define penetration kinetics and the effects of decontamination within biological structures. In this study, we aim to demonstrate that high-resolution optical coherence tomography (HR-OCT) can close this gap. Rabbit corneas were exposed ex vivo to 2.5% hydrofluoric acid (HF) solution, and microstructural changes were monitored in the time domain by OCT imaging. HF application and penetration resulted in shrinkage of the corneal thickness, interpreted as a result of osmolar changes and of loss of water-binding capacity, and a substantial increase in OCT signal amplitudes. The effectiveness of different rinsing solutions on the chemical burn was also evaluated. With tap water and with 1% calcium gluconate, the deep corneal stroma remained clear until the end of the rinsing period but became opaque afterwards. With Hexafluorine, the cornea remained clear for 60 min after rinsing ceased. We conclude that HR-OCT can assist in the clinical evaluation of an ex vivo eye irritation test, and that decontamination of an HF burn using Hexafluorine is efficient.

  15. Optical Probe of the Superconducting Normal Mixed State in a Magnetic Penetration Thermometer

    NASA Technical Reports Server (NTRS)

    Stevenson, T. R.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Lee, S. -J.; Nagler, P. C.; Smith, S. J.

    2016-01-01

    Using ultraviolet photon pulses, we have probed the internal behavior of a molybdenum-gold Magnetic Penetration Thermometer (MPT) that we designed for x-ray microcalorimetry. In this low-temperature detector, the diamagnetic response of a superconducting MoAu bilayer is used to sense temperature changes in response to absorbed photons. We have previously described an approximate model that explains the high responsivity of the detector to temperature changes as a consequence of a Meissner transition of the molybdenum-gold film in the magnetic field applied by the superconducting circuit used to bias the detector. We compare measurements of MPT heat capacity and thermal conductance, derived from UV photon pulse data, to our model predictions for the thermodynamic properties of the sensor and for the electron cooling obtained by quasiparticle recombination. Our data on electron cooling power is also relevant to the operation of other superconducting detectors, such as Microwave Kinetic Inductance Detectors.

  16. Variable phenotypic penetrance of thrombosis in adult mice after tissue-selective and temporally controlled Thbd gene inactivation

    PubMed Central

    van Mens, Thijs E.; Liang, Hai-Po H.; Basu, Sreemanti; Hernandez, Irene; Zogg, Mark; May, Jennifer; Zhan, Min; Yang, Qiuhui; Foeckler, Jamie; Kalloway, Shawn; Sood, Rashmi; Karlson, Caren Sue; Weiler, Hartmut

    2017-01-01

    Thrombomodulin (Thbd) exerts pleiotropic effects on blood coagulation, fibrinolysis, and complement system activity by facilitating the thrombin-mediated activation of protein C and thrombin-activatable fibrinolysis inhibitor and may have additional thrombin- and protein C (pC)-independent functions. In mice, complete Thbd deficiency causes embryonic death due to defective placental development. In this study, we used tissue-selective and temporally controlled Thbd gene ablation to examine the function of Thbd in adult mice. Selective preservation of Thbd function in the extraembryonic ectoderm and primitive endoderm via the Meox2Cre-transgene enabled normal intrauterine development of Thbd-deficient (Thbd−/−) mice to term. Half of the Thbd−/− offspring expired perinatally due to thrombohemorrhagic lesions. Surviving Thbd−/− animals only rarely developed overt thrombotic lesions, exhibited low-grade compensated consumptive coagulopathy, and yet exhibited marked, sudden-onset mortality. A corresponding pathology was seen in mice in which the Thbd gene was ablated after reaching adulthood. Supplementation of activated PC by transgenic expression of a partially Thbd-independent murine pC zymogen prevented the pathologies of Thbd−/− mice. However, Thbd−/− females expressing the PC transgene exhibited pregnancy-induced morbidity and mortality with near-complete penetrance. These findings suggest that Thbd function in nonendothelial embryonic tissues of the placenta and yolk sac affects through as-yet-unknown mechanisms the penetrance and severity of thrombosis after birth and provide novel opportunities to study the role of the natural Thbd-pC pathway in adult mice and during pregnancy. PMID:28920104

  17. Increasing the penetration depth for ultrafast laser tissue ablation using glycerol based optical clearing

    NASA Astrophysics Data System (ADS)

    Gabay, Ilan; Subramanian, Kaushik G.; Martin, Chris; Yildirim, Murat; Tuchin, Valery V.; Ben-Yakar, Adela

    2016-03-01

    Background: Deep tissue ablation is the next challenge in ultrafast laser microsurgery. By focusing ultrafast pulses below the tissue surface one can create an ablation void confined to the focal volume. However, as the ablation depth increases in a scattering tissue, increase in the required power can trigger undesired nonlinear phenomena out of focus that restricts our ability to ablate beyond a maximum ablation depth of few scattering lengths. Optical clearing (OC) might reduce the intensity and increase the maximal ablation depth by lowering the refractive index mismatch, and therefore reducing scattering. Some efforts to ablate deeper showed out of focus damage, while others used brutal mechanical methods for clearing. Our clinical goal is to create voids in the scarred vocal folds and inject a biomaterial to bring back the tissue elasticity and restore phonation. Materials and methods: Fresh porcine vocal folds were excised and applied a biocompatible OC agent (75% glycerol). Collimated transmittance was monitored. The tissue was optically cleared and put under the microscope for ablation threshold measurements at different depths. Results: The time after which the tissue was optically cleared was roughly two hours. Fitting the threshold measurements to an exponential decay graph indicated that the scattering length of the tissue increased to 83+/-16 μm, which is more than doubling the known scattering length for normal tissue. Conclusion: Optical clearing with Glycerol increases the tissue scattering length and therefore reduces the energy for ablation and increases the maximal ablation depth. This technique can potentially improve clinical microsurgery.

  18. Physical insights from a penetration depth model of optically pumped NMR.

    PubMed

    Mui, Stacy; Ramaswamy, Kannan; Hayes, Sophia E

    2008-02-07

    A model of optically pumped NMR (OPNMR) behavior in GaAs that connects the photon energy dependence of the OPNMR signal intensity for (69)Ga with different polarizations of light has been developed. Inputs to this model include experimental conditions--external magnetic field (B(0)), temperature (T), and optical pumping parameters (tau(L), laser helicity)--as well as parameters that arise from sample-specific characteristics--electron spin lifetime (T(1e)), electron lifetime (tau(e)), electron-nuclear correlation time (tau(c)), and sample thickness (z). These various inputs affect the profile of the OPNMR signal intensity as a function of photon energy (E) in a predictable manner. Therefore, the profile can serve as a composite fingerprint by which individual parameters can be inferred when not known. Characteristics of the profile include the photon energy for maximum OPNMR signal intensity and the intensity ratio between sigma(+) and sigma(-) light.

  19. Pattern of stylet penetration activity by Homalodisca vitripennis (Hemiptera: Cicadellidae) adults in relation to environmental temperature and light conditions

    USDA-ARS?s Scientific Manuscript database

    Effects of ambient spring air temperature and light intensity on stylet penetration activities of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar) were studied outdoors, at ambient light and temperatures, using an electrical penetration graph (EPG). EPG waveforms representing saliva...

  20. Penetration kinetics of dimethyl sulphoxide and glycerol in dynamic optical clearing of porcine skin tissue in vitro studied by Fourier transform infrared spectroscopic imaging.

    PubMed

    Jiang, Jingying; Boese, Matthias; Turner, Paul; Wang, Ruikang K

    2008-01-01

    By use of a Fourier transform infrared (FTIR) spectroscopic imaging technique, we examine the dynamic optical clearing processes occurring in hyperosmotically biocompatible agents penetrating into skin tissue in vitro. The sequential collection of images in a time series provides an opportunity to assess penetration kinetics of dimethyl sulphoxide (DMSO) and glycerol beneath the surface of skin tissue over time. From 2-D IR spectroscopic images and 3-D false color diagrams, we show that glycerol takes at least 30 min to finally penetrate the layer of epidermis, while DMSO can be detected in epidermis after only 4 min of being topically applied over stratum corneum sides of porcine skin. The results demonstrate the potential of a FTIR spectroscopic imaging technique as an analytical tool for the study of dynamic optical clearing effects when the bio-tissue is impregnated by hyperosmotically biocompatible agents such as glycerol and DMSO.

  1. Postural adaptations to repeated optic flow stimulation in older adults.

    PubMed

    O'Connor, Kathryn W; Loughlin, Patrick J; Redfern, Mark S; Sparto, Patrick J

    2008-10-01

    The purpose of this study is to understand the processes of adaptation (changes in within-trial postural responses) and habituation (reductions in between-trial postural responses) to visual cues in older and young adults. Of particular interest were responses to sudden increases in optic flow magnitude. The postural sway of 25 healthy young adults and 24 healthy older adults was measured while subjects viewed anterior-posterior 0.4 Hz sinusoidal optic flow for 45 s. Three trials for each of three conditions were performed: (1) constant 12 cm optic flow amplitude (24 cm peak-to-peak), (2) constant 4 cm amplitude (8 cm p-t-p), and (3) a transition in amplitude from 4 to 12 cm. The average power of head sway velocity (P(vel)) was calculated for consecutive 5s intervals during the trial to examine the changes in sway within and between trials. A mixed factor repeated measures ANOVA was performed to examine the effects of subject Group, Trial, and Interval on the P(vel). P(vel) was greater in older adults in all conditions (p<0.001). During the 12 cm constant amplitude trials, within-trial adaptation occurred for all subjects, but there were differences in the between-trial habituation. P(vel) of the older adults decreased significantly between all 3 trials, but decreased only between Trials 1 and 2 in young adults. While the responses of the young adults to the transition in optic flow from 4 to 12 cm did not significantly change, older adults had an increase in P(vel) following the transition, ranging from 6.5 dB for the first trial to 3.4 dB for the third trial. These results show that older adults can habituate to repeated visual perturbation exposures; however, this habituation requires a greater number of exposures than young adults. This suggests aging impacts the ability to quickly modify the relative weighting of the sensory feedback for postural stabilization.

  2. Ginkgo biloba extract facilitates recovery from penetrating brain injury in adult male rats.

    PubMed

    Attella, M J; Hoffman, S W; Stasio, M J; Stein, D G

    1989-07-01

    Adult, male Sprague-Dawley rats received 100 mg/kg Ginkgo biloba extract (GBE) intraperitoneally for 30 days. GBE reduced overall activity and decreased sensitivity to light in the open field maze. The rats were also less responsive to noxious stimuli after 13 days of treatment with GBE. After the last injection, all subjects were trained on a delayed-spatial alternation task. Subsequent to acquisition of the spatial task, the rats received either sham operations and saline or bilateral frontal cortex lesions treated with either saline or GBE. Thirty additional days of treatment began on the day of injury, and open field behavior, analgesia, and metabolic activity measurements were again measured. The rats with lesions treated with saline were more active than their GBE-treated counterparts and sham controls but there were no differences in response to illumination or noxious stimuli. Retention of the delayed-spatial alternation indicated that rats with lesions treated with GBE were less impaired than brain-injured subjects receiving saline treatment. Histological examination showed that GBE reduced the extent of brain swelling in response to the injury.

  3. Optic Neuritis Caused by Rathke's Cleft Cyst in Young Adult

    PubMed Central

    Kobayashi, Namie; Oshitari, Toshiyuki; Kobayashi, Kentaro; Onoda, Takatsugu; Ikeda, Hidetoshi; Adachi-Usami, Emiko

    2014-01-01

    We report a case of right optic neuritis caused by Rathke's cleft cyst (RCC) in a young adult. A 15-year-old boy presented with reduced visual acuity in the right eye. He was diagnosed with optic neuritis in the right eye 4 years earlier at other clinics before he was referred to our department. During our one-year examinations, the cause of the reduced vision in his right eye could not be determined conclusively. At the age of 17 years, a RCC was detected by a neurosurgeon who specialized in hypophyseal diseases. He underwent microscopic transsphenoidal resection of the cyst, and his vision recovered to 1.2 and he has had no recurrence for at least 9 months. We suggest that repeated rupturing of the RCC was the cause of the optic neuritis, and a RCC can be successfully treated by surgery even after 3 years of optic neuritis. PMID:25045561

  4. Weld seam tracking and lap weld penetration monitoring using the optical spectrum of the weld plume

    SciTech Connect

    Mueller, R.E.; Hopkins, J.A.; Semak, V.V.; McCay, M.H.

    1996-12-31

    Joining of dissimilar materials is a long standing problem in manufacturing, with many tricks and special techniques developed to successfully join specific pairs of materials. Often, these special techniques impose stringent requirements on the process such as precise control of process parameters to achieve the desired joint characteristics. Laser welding is one of the techniques which has had some success in welding dissimilar metal alloys, and appears to be a viable process for these materials. Minimal heat input limits differential thermal expansion, and the small weld pool allows precise control of alloy mixing in the fusion zone. Obtaining optimal weld performance requires accurate monitoring and control of absorbed laser power and weld focus position. In order to monitor the laser welding process, the authors have used a small computer controlled optical spectrometer to observe the emission from the weld plume. Absorbed laser power can be related to the temperature of the weld pool surface and the plume above the weld. Focus position relative to the joint can easily be seen by the proportion of elements from each material existing in the plume. This monitor has been used to observe and optimize the performance of butt and lap welds between dissimilar alloys, where each alloy contains at least one element not found in the other alloy. Results will be presented for a copper-steel butt joint and a lap weld between stainless and low alloy steels.

  5. PENETRATING THE HOMUNCULUS-NEAR-INFRARED ADAPTIVE OPTICS IMAGES OF ETA CARINAE

    SciTech Connect

    Artigau, Etienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-06-15

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the 'butterfly nebula', outlined by bright Br{gamma} and H{sub 2} emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in {eta} Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10{sup 0}-20{sup 0} above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star.

  6. Penetrating the Homunculus -- Near-Infrared Adaptive Optics Images of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Martin, John C.; Artigau, E.; Davidson, K.; Humphreys, R. M.; Chesneau, O.; Smith, N.

    2010-01-01

    We present the extraordinary near-infrared images of Eta Carinae obtained with the Near-Infrared Coronagraphic Camera (NICI) with adaptive optics on the Gemini South telescope just after Eta Car's 2009 spectroscopic event. The K-band continuum and continuum-subtracted narrow-band Br-gamma and H2 images show a three-winged pattern outlined by bright emitting dust in the innermost region of the ejecta around the central star. This intriguing pattern was first noticed by Chesneau et al. (2005) from earlier VLT/NaCO images and was named the "butterfly nebula.” In contrast the with the Br-gamma and H2 images, the [Fe II] image does not follow the outline of the "butterfly wings,” but instead shows a much broader, bipolar distribution traced to about 2 arcsec from the star. We suggest that the [Fe II] emission is tracing the "little Homunculus" previously observed only spectroscopically, and attributed to a bipolar outflow from Eta Car's second eruption in the 1890's. The nature of the "butterfly nebula" is debated and may be due to an ouflow or to an equatorial torus. Kinematic data is needed to measure or set limits on its expansion, age and orientation within the larger Homunculus. In this poster we also report the results of our measurements of the transverse motions of the knots and filaments that outline the "butterfly."

  7. Implantation of a collagen scaffold seeded with adult rat hippocampal progenitors in a rat model of penetrating brain injury.

    PubMed

    Elias, Paul Z; Spector, Myron

    2012-07-30

    Penetrating brain injury (PBI) is a complex central nervous system injury in which mechanical damage to brain parenchyma results in hemorrhage, ischemia, broad areas of necrosis, and eventually cavitation. The permanent loss of brain tissue affords the possibility of treatment using a biomaterial scaffold to fill the lesion site and potentially deliver pharmacological or cellular therapeutic agents. The administration of cellular therapy may be of benefit in both mitigating the secondary injury process and promoting regeneration through replacement of certain cell populations. This study investigated the survival and differentiation of adult rat hippocampal neural progenitor cells delivered by a collagen scaffold in a rat model of PBI. The cell-scaffold construct was implanted 1 week after injury and was observed to remain intact with open pores upon analysis 4 weeks later. Implanted neural progenitors were found to have survived within the scaffold, and also to have migrated into the surrounding brain. Differentiated phenotypes included astrocytes, oligodendrocytes, vascular endothelial cells, and possibly macrophages. The demonstrated multipotency of this cell population in vivo in the context of traumatic brain injury has implications for regenerative therapies, but additional stimulation appears necessary to promote neuronal differentiation outside normally neurogenic regions. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Penetrating the Homunculus—Near-Infrared Adaptive Optics Images of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Artigau, Étienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-06-01

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the "butterfly nebula," outlined by bright Brγ and H2 emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in η Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10°-20° above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star. Based on observations obtained at the Gemini Observatory (program ID: GS-2008B-DD-6), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  9. Very high penetrance and occurrence of Leber’s hereditary optic neuropathy in a large Han Chinese pedigree carrying the ND4 G11778A mutation

    PubMed Central

    Zhou, Xiangtian; Zhang, Hongxing; Zhao, Fuxin; Ji, Yanchun; Tong, Yi; Zhang, Juanjuan; Zhang, Yu; Yang, Li; Qian, Yaping; Lu, Fan; Qu, Jia; Guan, Min-Xin

    2010-01-01

    We report here the clinical, genetics and molecular characterization of a five-generation Han Chinese family with Leber’s hereditary optic neuropathy (LHON). Strikingly, this family exhibits very high penetrance and occurrence of optic neuropathy. In particular, twenty-five (10 males/15 females) of 30 matrilineal relatives exhibited the variable severity, ranging from profound to mild of visual impairment. This penetrance of optic neuropathy in this Chinese family is much higher than those in many families with LHON worldwide. The age-at-onset for visual impairment in matrilineal relatives in this Chinese family varied from 7 to 24 years old, with the average of 15 years old. Furthermore, the ratio between affected male and female matrilineal relatives is 1:1.5 in the Chinese family. This observation is in contrast with the typical features in LHON pedigrees that there was predominance of affected males in LHON in many families from different ethnic origins. Molecular analysis of mitochondrial genome identified the known ND4 G11778A mutation and 51 variants, belonging to Asian haplogroup C4a1. The absence of other known secondary LHON-associated and functionally significant mtDNA mutations in this Chinese family suggested that mitochondrial variants may not play an important role in the phenotypic manifestation of the G11778A mutation in this Chinese family. Therefore, nuclear modifier gene(s) may be responsible for very high penetrance and occurrence of optic neuropathy in this Chinese pedigree. PMID:20627642

  10. Monte Carlo study of skin optical clearing to enhance light penetration in the tissue: implications for photodynamic therapy of acne vulgaris

    NASA Astrophysics Data System (ADS)

    Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.; Altshuler, Gregory B.; Yaroslavsky, Ilya V.

    2008-06-01

    Result of Monte Carlo simulations of skin optical clearing is presented. The model calculations were carried out with the aim of studying of spectral response of skin under immersion liquids action and calculation of enhancement of light penetration depth. In summary, we have shown that: 1) application of glucose, propylene glycol and glycerol produced significant decrease of light scattering in different skin layers; 2) maximal clearing effect will be obtained in case of optical clearing of skin dermis, however, absorbed light fraction in skin dermis changed insignificantly, independently on clearing agent and place it administration; 3) in contrast to it, the light absorbed fraction in skin adipose layer increased significantly in case of optical clearing of skin dermis. It is very important because it can be used for development of optical methods of obesity treatment; 4) optical clearing of superficial skin layers can be used for decreasing of power of light radiation used for treatment of acne vulgaris.

  11. Achilles Tendon Penetration for Continuous 810 nm and Superpulsed 904 nm Lasers Before and After Ice Application: An In Situ Study on Healthy Young Adults.

    PubMed

    Haslerud, Sturla; Naterstad, Ingvill Fjell; Bjordal, Jan Magnus; Lopes-Martins, Rodrigo Alvaro Brandão; Magnussen, Liv Heide; Leonardo, Patrícia Sardinha; Marques, Ricardo Henrique; Joensen, Jon

    2017-10-01

    There is a lack of knowledge about the influence tissue temperature may have on laser light penetration and tendon structure. The purpose of this study was to investigate whether penetration of laser energy in human Achilles tendons differed before and after ice pack application. The Achilles tendons (n = 54) from 27 healthy young adults were irradiated with two class 3B lasers (810 nm 200 mW continuous mode laser and a 904 nm 60 mW superpulsed mode laser). The optical energy penetrating the Achilles area was measured before and after 20 min of ice application. Measurements were obtained after 30, 60, and 120 sec irradiation with the 904 nm laser and after 30 and 60 sec irradiation with the 810 nm laser. Achilles tendon thickness was measured with ultrasonography. Optical energy penetration increased significantly (p < 0.01) after ice application for both lasers and at all time points from 0.34% to 0.39% of energy before ice application to 0.43-0.52% of energy after ice application for the 904 nm laser and from 0.24% to 0.25% of energy before ice application to 0.30-0.31% of energy after ice application for the 810 nm laser. The energy loss per centimeter of irradiated tissue was significantly higher (p < 0.05) at all time points after ice application. Ultrasonography imaging of skin-to-skin and transversal tendon thickness was significantly reduced after ice application at p = 0.05 and p = 0.03, respectively. Achilles tendon thickness in the longitudinal plane remained unchanged (p = 0.49). The penetration of laser light increased significantly through healthy Achilles tendons subjected to 20 min of cooling. These findings occurred in the presence of a significant reduction in skin temperature and Achilles tendon thickness.

  12. Liquid penetrants

    NASA Technical Reports Server (NTRS)

    Pasley, R. L.

    1973-01-01

    Liquid-penetrant inspection is discussed for surface defects in solids. The principle advantages are considered to be its simplicity and economy. The techniques and penetrants are described along with the developers. Commercially available equipment is also described.

  13. Penetration Testing of the OPRA Regolith Penetrator

    NASA Astrophysics Data System (ADS)

    El Shafie, A.; Kegege, O.; Barrows, S.; Roe, L.; Ulrich, R.

    2008-03-01

    Our work focuses on the mechanical design and penetration forces for the Optical Probe for Regolith Analysis. This is a spike-shaped probe delivered to a planet, asteroid, or cometary body by a lander to provide IR spectroscopy of the subsurface.

  14. Regeneration of optic nerve fibers of adult mammals.

    PubMed

    Watanabe, Masami

    2010-09-01

    The pathway from the retina to the brain in mammals provides a well-defined model system for investigation of not only surviving axotomy but also axonal regeneration of injured neurons. Here I introduce our recent works on axonal regeneration in the optic nerve (OpN) of adult cats. Fibers of retinal ganglion cells (RGCs) extend beyond the crush site of OpN with injections of a macrophage stimulator (oxidized galectin-1) or a Rho kinase (ROCK) inhibitor (Y-39983 or Y-27632) while axonal extension is blocked with injection of saline. Elongation of crushed optic fibers, however, is slowed after 2 weeks. Transplantation of peripheral nerve makes RGCs regenerate their transected axons into a graft but regenerated fibers extend only a few mm in the brain. Effectiveness of combination of the drugs and treatments has to be verified in future.

  15. Penetration equations

    SciTech Connect

    Young, C.W.

    1997-10-01

    In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.

  16. Sub‐40 fs, 1060‐nm Yb‐fiber laser enhances penetration depth in nonlinear optical microscopy of human skin

    PubMed Central

    Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

    2015-01-01

    Abstract. Advancing the practical utility of nonlinear optical microscopy requires continued improvement in imaging depth and contrast. We evaluated second‐harmonic generation (SHG) and third‐harmonic generation images from ex vivo human skin and showed that a sub‐40 fs, 1060‐nm Yb‐fiber laser can enhance SHG penetration depth by up to 80% compared to a >100  fs, 800 nm Ti:sapphire source. These results demonstrate the potential of fiber‐based laser systems to address a key performance limitation related to nonlinear optical microscopy (NLOM) technology while providing a low‐barrier‐to‐access alternative to Ti:sapphire sources that could help accelerate the movement of NLOM into clinical practice. PMID:26641198

  17. Characterization of penetration depth as a function of optical fiber separation at various absorption and scatter coefficients for a noninvasive metabolic sensor

    NASA Astrophysics Data System (ADS)

    DeMilo, Charles; Brukilacchio, Thomas; Soller, Babs R.; Soyemi, Olusola

    2004-06-01

    A visible-near IR (500-1,000nm) fiber optic sensor is under development that is intended to non-invasively assess muscle metabolism through the measurement of tissue pH and oxygen partial pressure. These parameters are calculated from the spectra of hemoglobin and myoglobin in muscle. The sensor consists of transmit (illumination) fibers and receive (detection) fibers that are coupled to a spectrometer. Light from the probe must penetrate below the surface of the skin and into a 5-10mm thick layer of muscle. A study was conducted to quantify the relationship between transmit and receive fiber separation and sensor penetration depth below the surface of the skin. A liquid phantom was created to replicate the absorption (μa) and reduced scatter coefficient (μs') profiles typically found in human blood and tissue. The phantom consisted of a solution of Intralipid and India ink in the appropriate concentrations to achieve desired reduced scatter coefficient and absorption profiles. The reduced scatter coefficient of the liquid phantom was achieved to an accuracy of +/-10% compared to previously published data. A fixed illumination fiber and translatable detector fiber were placed in the liquid phantom, and the fiber separation was varied from 3-40mm. Values of μa and μs' varied from 0.03-0.40 cm-1 and 5.0-15.0 cm-1 respectively. Results from the experiment demonstrate a strong correlation between penetration depth and fiber separation. Additionally, it was found that penetration depth was not substantially influenced by absorption and scatter concentration. As signal-to-noise is an important parameter in many non-invasive biomedical applications, the relative signal as a function of fiber separation was determined to follow an exponential relationship.

  18. Penetration studies of topically applied substances: Optical determination of the amount of stratum corneum removed by tape stripping.

    PubMed

    Lademann, J; Ilgevicius, A; Zurbau, O; Liess, H D; Schanzer, S; Weigmann, H J; Antoniou, C; Pelchrzim, R V; Sterry, W

    2006-01-01

    Tape stripping is a standard measuring method for the investigation of the dermatopharmacokinetics of topically applied substances using adhesive films. These tape strips are successively applied and removed from the skin after application and penetration of topically applied substances. Thus, layers of corneocytes and some amount of topical applied substances are removed. The amount of substances and the amount of stratum corneum removed with a single tape strip has to be determined for the calculation of the penetration profile. The topically applied substances removed from the skin can be determined by classical analytical methods like high-pressure liquid chromatography, mass spectroscopy, and spectroscopic measurements. The amount of corneocytes on the tape strips can be easily detected by their pseudoabsorption. In the present paper, an easy and cheap corneocyte density analyzer is presented that is based on a slide projector. Comparing the results of the measurements obtained by the corneocyte density analyzer and by uv-visible spectrometry, identical results were obtained.

  19. Pattern of stylet penetration activity by Homalodisca vitripennis (Hemiptera: Cicadellidae) adults in relation to environmental temperature and light conditions.

    PubMed

    Son, Youngsoo; Backus, Elaine A; Groves, Russell L; Johnson, Marshall W

    2012-10-01

    Effects of ambient spring air temperature and light intensity on stylet penetration activities of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar), were studied under field conditions by using an electrical penetration graph. Electrical penetration graph waveforms representing salivary sheath formation and searching (pathway phase), xylem contact (X waves), and ingestion of xylem fluid (waveform C) were analyzed. Previous research supported the concept that acquisition of Xylella fastidiosa, the Pierce's disease bacterium, occurs during ingestion, whereas inoculation occurs during xylem contact periods (X waves). Diel patterns of H. vitripennis stylet activity showed that, regardless of light condition, xylem ingestion occurred for the longest duration when temperature remained above the feeding threshold (10°C), and only occurred at temperatures below the threshold when ingestion was continued from a preceding, warmer time. Regression analysis indicated that mean waveform durations per insect (WDI) for combined stylet activities (pathway and ingestion) as well as X wave frequencies were significantly influenced by temperature, but there was no significant impact of light intensity or interaction between temperature and light intensity. The relationship between temperature and stylet activities in terms of WDI and X wave frequency was described using linear and nonlinear models. Validation of the nonlinear models indicated that they well predicted the WDIs for both ingestion and combined stylet activities, using temperature only as a single input. Overall, findings clearly demonstrate that temperature is an important factor that influences the H. vitripennis feeding behaviors responsible for transmission (acquisition and inoculation) of the Pierce's disease bacterium, with implications for vector ecology and management, as well as disease epidemiology.

  20. Development of a high power supercontinuum source in the 1.7 μm wavelength region for highly penetrative ultrahigh-resolution optical coherence tomography

    PubMed Central

    Kawagoe, H.; Ishida, S.; Aramaki, M.; Sakakibara, Y.; Omoda, E.; Kataura, H.; Nishizawa, N.

    2014-01-01

    We developed a high power supercontinuum source at a center wavelength of 1.7 μm to demonstrate highly penetrative ultrahigh-resolution optical coherence tomography (UHR-OCT). A single-wall carbon nanotube dispersed in polyimide film was used as a transparent saturable absorber in the cavity configuration and a high-repetition-rate ultrashort-pulse fiber laser was realized. The developed SC source had an output power of 60 mW, a bandwidth of 242 nm full-width at half maximum, and a repetition rate of 110 MHz. The average power and repetition rate were approximately twice as large as those of our previous SC source [20]. Using the developed SC source, UHR-OCT imaging was demonstrated. A sensitivity of 105 dB and an axial resolution of 3.2 μm in biological tissue were achieved. We compared the UHR-OCT images of some biological tissue samples measured with the developed SC source, the previous one, and one operating in the 1.3 μm wavelength region. We confirmed that the developed SC source had improved sensitivity and penetration depth for low-water-absorption samples. PMID:24688825

  1. Penetration of UV-A, UV-B, blue, and red light into leaf tissues of pecan measured by a fiber optic microprobe system

    NASA Astrophysics Data System (ADS)

    Qi, Yadong; Bai, Shuju; Vogelmann, Thomas C.; Heisler, Gordon M.

    2003-11-01

    The depth of light penetration from the adaxial surfaces of the mature leaves of pecan (Carya illinoensis) was measured using a fiber optic microprobe system at four wavelengths: UV-B (310nm), UV-A (360 nm), blue light (430nm), and red light (680nm). The average thickness of the leaf adaxial epidermal layer was 15um and the total leaf thickness was 219um. The patterns of the light attenuation by the leaf tissues exhibited strong wavelength dependence. The leaf adaxial epidermal layer was chiefly responsible for absorbing the UV-A UV-B radiation. About 98% of 310 nm light was steeply attenuated within the first 5 um of the adaxial epidermis; thus, very little UV-B radiation was transmitted to the mesophyll tissues where contain photosynthetically sensitive sites. The adaxial epidermis also attenuated 96% of the UV-A radiation. In contrast, the blue and red light penetrated much deeper and was gradually attenutated by the leaves. The mesophyll tissues attenuated 17% of the blue light and 42% of the red light, which were available for photosynthesis use. Since the epidermal layer absorbed nearly all UV-B light, it acted as an effective filter screening out the harmful radiation and protecting photosynthetically sensitive tissues from the UV-B damage. Therefore, the epidermal function of the UV-B screening effectiveness can be regarded as one of the UV-B protection mechanisms in pecan.

  2. Effect of masticatory load on crack deflection/penetration investigated with en-face optical coherence tomography in ceramic fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Marsavina, Liviu; Negru, Radu; Hluscu, Mihai; Caplescu, Cristiana; Bradu, Adrian; Hughes, Michael; Rominu, Mihai; Podoleanu, Adrian Gh.

    2009-02-01

    Optical Coherence Tomography (OCT) allows a better characterization of dental prostheses. The detection of substance defects within the ceramic layers for metal-ceramic prostheses was demonstrated. The detected defects have a large volume and therefore there is a high likelihood for fracture lines to be generated in the proximal areas of the ceramic fixed partial dentures. If the detection of such defects is feasible before inserting the prosthesis into the oral cavity, then timely corrective measures are possible in order to avoid the fracture of the ceramic component later on. After noninvasive localization of cracks in ceramic fixed partial dentures, the effect of the biaxial loading on crack deflection/penetration at the ceramic interface was investigated. A biaxial loaded geometry was numerically investigated using Finite Element Analysis in order to determine the energy release rate. The obtained results could be used in conjunction with criteria at interface for estimating the path of the crack after the interface was reached.

  3. Model for estimating the penetration depth limit of the time-reversed ultrasonically encoded optical focusing technique

    PubMed Central

    Jang, Mooseok; Ruan, Haowen; Judkewitz, Benjamin; Yang, Changhuei

    2014-01-01

    The time-reversed ultrasonically encoded (TRUE) optical focusing technique is a method that is capable of focusing light deep within a scattering medium. This theoretical study aims to explore the depth limits of the TRUE technique for biological tissues in the context of two primary constraints – the safety limit of the incident light fluence and a limited TRUE’s recording time (assumed to be 1 ms), as dynamic scatterer movements in a living sample can break the time-reversal scattering symmetry. Our numerical simulation indicates that TRUE has the potential to render an optical focus with a peak-to-background ratio of ~2 at a depth of ~103 mm at wavelength of 800 nm in a phantom with tissue scattering characteristics. This study sheds light on the allocation of photon budget in each step of the TRUE technique, the impact of low signal on the phase measurement error, and the eventual impact of the phase measurement error on the strength of the TRUE optical focus. PMID:24663917

  4. High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA

    USGS Publications Warehouse

    Mallinson, D.; Mahan, S.; Moore, Christine

    2008-01-01

    Geophysical surveys, sedimentology, and optically-stimulated luminescence age analyses were used to assess the geologic development of a coastal system near Swansboro, NC. This area is a significant Woodland Period Native American habitation and is designated the "Broad Reach" archaeological site. 2-d and 3-d subsurface geophysical surveys were performed using a ground penetrating radar system to define the stratigraphic framework and depositional facies. Sediment samples were collected and analyzed for grain-size to determine depositional environments. Samples were acquired and analyzed using optically stimulated luminescence techniques to derive the depositional age of the various features. The data support a low eolian to shallow subtidal coastal depositional setting for this area. Li-DAR data reveal ridge and swale topography, most likely related to beach ridges, and eolian features including low-relief, low-angle transverse and parabolic dunes, blowouts, and a low-relief eolian sand sheet. Geophysical data reveal dominantly seaward dipping units, and low-angle mounded features. Sedimentological data reveal mostly moderately-well to well-sorted fine-grained symmetrical to coarse skewed sands, suggesting initial aqueous transport and deposition, followed by eolian reworking and bioturbation. OSL data indicate initial coastal deposition prior to ca. 45,000 yBP, followed by eolian reworking and low dune stabilization at ca. 13,000 to 11,500 yBP, and again at ca. 10,000 yBP (during, and slightly after the Younger Dryas chronozone).

  5. Regenerating Fish Optic Nerves and a Regeneration-Like Response in Injured Optic Nerves of Adult Rabbits

    NASA Astrophysics Data System (ADS)

    Schwartz, M.; Belkin, M.; Harel, A.; Solomon, A.; Lavie, V.; Hadani, M.; Rachailovich, I.; Stein-Izsak, C.

    1985-05-01

    Regeneration of fish optic nerve (representing regenerative central nervous system) was accompanied by increased activity of regeneration-triggering factors produced by nonneuronal cells. A graft of regenerating fish optic nerve, or a ``wrap-around'' implant containing medium conditioned by it, induced a response associated with regeneration in injured optic nerves of adult rabbits (representing a nonregenerative central nervous system). This response was manifested by an increase of general protein synthesis and of selective polypeptides in the retinas and by the ability of the retina to sprout in culture.

  6. Histologically benign, clinically aggressive: Progressive non-optic pathway pilocytic astrocytomas in adults with NF1.

    PubMed

    Strowd, Roy E; Rodriguez, Fausto J; McLendon, Roger E; Vredenburgh, James J; Chance, Aaron B; Jallo, George; Olivi, Alessandro; Ahn, Edward S; Blakeley, Jaishri O

    2016-06-01

    Although optic pathway gliomas are the most common brain tumors associated with neurofibromatosis type 1 (NF1), extra-optic gliomas occur and may behave more aggressively with outcomes that differ by age. A retrospective case-control study was designed to describe the clinical course of adult NF1 patients with progressive extra-optic pilocytic astrocytomas (PAs) and compare to a pediatric cohort. Data for patients treated at the Johns Hopkins Comprehensive Neurofibromatosis Center from 2003 to 2013 were reviewed to identify cases (adults, age >18) and controls (pediatric, age <18) with clinically or radiographically progressive extra-optic PAs. Demographic, clinical, histologic, and radiographic data were collected. Three adult NF1 cases and four pediatric NF1 controls were identified. Mean age was 32.3 ± 9.5 years, 66% male (cases); 12.8 ± 4.2 years, 100% male (controls). Symptomatic progression occurred in two-of-three adults (67%) while the majority of pediatric patients presented with isolated radiographic progression (n = 3, 75%). Onset tended to be more rapid in adults (4 ± 1 vs. 14 ± 8.3 months, P = 0.10). Subtotal resection was the treatment for all pediatric patients. Radiotherapy (n = 2), chemotherapy (n = 2), and targeted, biologic agents (n = 2) were administered in adults. Although all pediatric patients are living, outcomes were universally poor in adults with progression to death in all (median survival 17.1 months, range 6.6-30.3). In conclusion, despite grade I histology, all three adult NF1 patients with progressive extra-optic PAs suffered an aggressive clinical course which was not seen in pediatric patients. Clinicians should be aware of this clinico-histologic discrepancy when counseling and managing adult NF1 patients with progressive extra-optic PAs. © 2016 Wiley Periodicals, Inc.

  7. Histologically Benign, Clinically Aggressive: Progressive Non-Optic Pathway Pilocytic Astrocytomas in Adults with NF1

    PubMed Central

    Strowd, Roy E.; Rodriguez, Fausto J.; McLendon, Roger E.; Vredenburgh, James J.; Chance, Aaron B.; Jallo, George; Olivi, Alessandro; Ahn, Edward S.; Blakeley, Jaishri O.

    2016-01-01

    Although optic pathway gliomas are the most common brain tumors associated with neurofibromatosis type 1 (NF1), extra-optic gliomas occur and may behave more aggressively with outcomes that differ by age. A retrospective case-control study was designed to describe the clinical course of adult NF1 patients with progressive extra-optic pilocytic astrocytomas (PAs) and compare to a pediatric cohort. Data for patients treated at the Johns Hopkins Comprehensive Neurofibromatosis Center from 2003 to 2013 were reviewed to identify cases (adults, age >18) and controls (pediatric, age <18) with clinically or radiographically progressive extra-optic PAs. Demographic, clinical, histologic, and radiographic data were collected. Three adult NF1 cases and four pediatric NF1 controls were identified. Mean age was 32.3 ± 9.5 years, 66% male (cases); 12.8±4.2 years, 100% male (controls). Symptomatic progression occurred in two-of-three adults (67%) while the majority of pediatric patients presented with isolated radiographic progression (n=3, 75%). Onset tended to be more rapid in adults (4±1 vs. 14±8.3 months, P=0.10). Subtotal resection was the treatment for all pediatric patients. Radiotherapy (n=2), chemotherapy (n=2), and targeted, biologic agents (n=2) were administered in adults. Although all pediatric patients are living, outcomes were universally poor in adults with progression to death in all (median survival 17.1 months, range 6.6–30.3). In conclusion, despite grade I histology, all three adult NF1 patients with progressive extra-optic PAs suffered an aggressive clinical course which was not seen in pediatric patients. Clinicians should be aware of this clinico-histologic discrepancy when counseling and managing adult NF1 patients with progressive extra-optic PAs. PMID:26992069

  8. Penetrant-Indication-Measuring Compass

    NASA Technical Reports Server (NTRS)

    Schaefer, Lloyd

    1991-01-01

    Modified drafting compass well suited to measurement of length of crack or width of area stained by penetrant-dye-inspection method. Equipped with any of variety of standard curved or straight pointed tips. Modification consists in coating tips with dye that fluoresces light pink under same ultraviolet inspection light causing penetrant dye to fluoresce yellow green. Used in locations inaccessible to conventional fluorescent comparator. Eliminates errors of optical distortion in comparator, also eliminates errors of interpolation.

  9. Time-Gated Optical Projection Tomography Allows Visualization of Adult Zebrafish Internal Structures

    PubMed Central

    Foglia, Efrem Alessandro; Pistocchi, Anna; D'Andrea, Cosimo; Valentini, Gianluca; Cubeddu, Rinaldo; De Silvestri, Sandro; Cerullo, Giulio; Cotelli, Franco

    2012-01-01

    Optical imaging through biological samples is compromised by tissue scattering and currently various approaches aim to overcome this limitation. In this paper we demonstrate that an all optical technique, based on non-linear upconversion of infrared ultrashort laser pulses and on multiple view acquisition, allows the reduction of scattering effects in tomographic imaging. This technique, namely Time-Gated Optical Projection Tomography (TGOPT), is used to reconstruct three dimensionally the internal structure of adult zebrafish without staining or clearing agents. This method extends the use of Optical Projection Tomography to optically diffusive samples yielding reconstructions with reduced artifacts, increased contrast and improved resolution with respect to those obtained with non-gated techniques. The paper shows that TGOPT is particularly suited for imaging the skeletal system and nervous structures of adult zebrafish. PMID:23185643

  10. Three-dimensional optical coherence tomography at 1050 nm versus 800 nm in retinal pathologies: enhanced performance and choroidal penetration in cataract patients.

    PubMed

    Povazay, Boris; Hermann, Boris; Unterhuber, Angelika; Hofer, Bernd; Sattmann, Harald; Zeiler, Florian; Morgan, James E; Falkner-Radler, Christiane; Glittenberg, Carl; Blinder, Susanne; Drexler, Wolfgang

    2007-01-01

    Frequency domain optical coherence tomography (FD-OCT), based on an all-reflective high-speed InGaAs spectrometer, operating in the 1050 nm wavelength region for retinal diagnostics, enables high-speed, volumetric imaging of retinal pathologies with greater penetration into choroidal tissue is compared to conventional 800 nm three-dimensional (3-D) ophthalmic FD-OCT systems. Furthermore, the lower scattering at this wavelength significantly improves imaging performance in cataract patients, thereby widening the clinical applicability of ophthalmic OCT. The clinical performance of two spectrometer-based ophthalmic 3-D OCT systems compared in respect to their clinical performance, one operating at 800 nm with 150 nm bandwidth (approximately 3 microm effective axial resolution) and the other at 1050 nm with 70 nm bandwidth (approximately 7 microm effective axial resolution). Results achieved with 3-D OCT at 1050 nm reveal, for the first time, decisive improvements in image quality for patients with retinal pathologies and clinically significant cataract.

  11. In vivo evaluation of optic nerve aging in adult rhesus monkey by diffusion tensor imaging

    PubMed Central

    Yan, Yumei; Li, Longchuan; Preuss, Todd M.; Hu, Xiaoping; Herndon, James G.

    2014-01-01

    Aging of the optic nerve can result in reduced visual sensitivity or vision loss. Normal optic nerve aging has been investigated previously in tissue specimens but poorly explored in vivo. In the present study, the normal aging of optic nerve was evaluated by diffusion tensor imaging (DTI) in non-human primates. Adult female rhesus monkeys at the ages of 9 to 13 years old (young group, n=8) and 21 to 27 years old (old group, n=7) were studied using parallel-imaging-based DTI on a clinical 3T scanner. Compared to young adults, the old monkeys showed 26% lower fractional anisotropy (P<0.01), and 44% greater radial diffusivity, although the latter difference was of marginal statistical significance (P=0.058). These MRI findings are largely consistent with published results of light and electron microscopic studies of optic nerve aging in macaque monkeys, which indicate a loss of fibers and degenerative changes in myelin sheaths. PMID:24649434

  12. Magnetic resonance diffusion tensor imaging of optic nerve and optic radiation in healthy adults at 3T.

    PubMed

    Sun, Hong-Hong; Wang, Dong; Zhang, Qiu-Juan; Bai, Zhi-Lan; He, Ping

    2013-01-01

    To investigate the diffusion characteristics of water of optic nerve and optic radiation in healthy adults and its related factors by diffusion tensor imaging (DTI) at 3T. A total of 107 healthy volunteers performed head conventional MRI and bilateral optic nerve and optic radiation DTI. The primary data of DTI was processed by post-processing software of DTI studio 2.3, obtaining fractional anisotropy value, mean diffusivity value, principal engine value, orthogonal engine value by measuring, and analyzed by the SPSS13.0 statistical software. The bilateral optic nerve and optic radiation fibers presented green color in directional encoded color (DEC) maps and presented high signal in fractional anisotropy (FA) maps. The FA value of the left optic nerve was 0.598±0.069 and the right was 0.593±0.065; the mean diffusivity (MD) value of the left optic nerve was (1.324±0.349)×10(-3)mm(2)/s and the right was (1.312±0.350)×10(-3)mm(2)/s; the principal engine value (λ‖) of the left optic nerve was (2.297±0.522)×10(-3)mm(2)/s and the right was (2.277±0.526)×10(-3)mm(2)/s; the orthogonal engine value (λ⊥) of the left optic nerve was (0.838±0.285)×10(-3)mm(2)/s and the right was (0.830±0.280)×10(-3)mm(2)/s; the FA value of the left optic radiation was 0.636±0.057 and the right was 0.628±0.056; the mean diffusivity (MD) value of the left optic radiation was (0.907±0.103)×10(-3)mm(2)/s and the right was (0.889±0.125)×10(-3)mm(2)/s; the principal eigenvalue (λ‖) of the left optic radiation was (1.655±0.210)×10(-3)mm(2)/s and the right was (1.614±0.171)×10(-3)mm(2)/s; the orthogonal enginvalue (λ⊥) of the left optic radiation was (0.531±0.103)×10(-3)mm(2)/s and the right was (0.524±0.152)×10(-3)mm(2)/s. There was no obvious difference between the FA, MD, λ‖, λ⊥ of the bilateral optic radiation and the bilateral optic nerve (P>0.05) and no obvious difference between male and female group. The FA, MD, λ‖, λ⊥ of the bilateral

  13. Cell proliferation and apoptosis in optic nerve and brain integration centers of adult trout Oncorhynchus mykiss after optic nerve injury

    PubMed Central

    Pushchina, Evgeniya V.; Shukla, Sachin; Varaksin, Anatoly A.; Obukhov, Dmitry K.

    2016-01-01

    Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA)-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix) area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1–4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration. PMID:27212918

  14. Cell proliferation and apoptosis in optic nerve and brain integration centers of adult trout Oncorhynchus mykiss after optic nerve injury.

    PubMed

    Pushchina, Evgeniya V; Shukla, Sachin; Varaksin, Anatoly A; Obukhov, Dmitry K

    2016-04-01

    Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA)-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix) area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1-4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration.

  15. A penetrating orbitocranial stab wound.

    PubMed Central

    MacEwen, C J; Fullarton, G

    1986-01-01

    An unusual case of intracranial penetration of a bread knife through the orbit is described. Despite the proximity of the blade to the internal carotids, the optic nerves and chiasm, and the pituitary the patient survived with only a minimal field defect affecting the eye opposite to the entry site; otherwise no neurological or endocrine deficit was evident. Images PMID:3947613

  16. Primary Gliosarcoma of the Optic Nerve: A Unique Adult Optic Pathway Glioma.

    PubMed

    Cimino, Patrick J; Sychev, Yevgeniy V; Gonzalez-Cuyar, Luis F; Mudumbai, Raghu C; Keene, C Dirk

    2016-10-11

    A 90-year-old woman presented with 1-year history of right-sided progressive proptosis, neovascular glaucoma, blindness, and worsening ocular pain. No funduscopic examination was possible because of a corneal opacity. Head CT scan without contrast demonstrated a heterogeneous 4.1 cm (anterior-posterior) by 1.7 cm (transverse) cylindrical mass arising in the right optic nerve and extending from the retrobulbar globe to the optic canal. She underwent palliative enucleation with subtotal resection of the orbital optic nerve and tumor. Pathological examination showed effacement of the optic nerve by an infiltrative high-grade glial neoplasm with biphasic sarcomeric differentiation. Invasion into the uvea and retina was present. The neoplasm was negative for melan-A, HMB45, tyrosinase, synaptophysin, smooth muscle actin, and epithelial membrane antigen. The glioma had strongly intense, but patchy immunopositivity for glial fibrillary acidic protein. Multiple foci of neoplastic cells had pericellular reticulin staining. The overall features were diagnostic of a gliosarcoma (World Health Organization grade IV) of the optic nerve. Postoperative MRI demonstrated postsurgical changes and residual gliosarcoma with extension into the optic chiasm. The patient died 2 and a half months after her enucleation surgery at her nursing home. Autopsy was unavailable due to the caregiver wishes, making a definitive cause of death unknown. Gliosarcoma is a rare variant of glioblastoma, and this is the first documented case presenting as a primary neoplasm of the optic nerve.

  17. Penetration of high-intensity Er:YAG laser light emitted by IR hollow optical fibers with sealing caps in water.

    PubMed

    Iwai, Katsumasa; Shi, Yi-Wei; Endo, Masashi; Ito, Kentaro; Matsuura, Yuji; Miyagi, Mitsunobu; Jelinkova, Helena

    2004-04-20

    The penetration depth in water was measured for Er:YAG laser light in a high density relevant to clinical applications. Various types of focusing elements were used to guide the light efficiently. We found that the transmission distance depended strongly on the beam shape in the water. When we used a plano-convex type of focusing cap, the penetration depth was larger than that when a dome- or ball-type cap were used.

  18. Application of ground-penetrating radar, digital optical borehole images, and cores for characterization of porosity hydraulic conductivity and paleokarst in the Biscayne aquifer, southeastern Florida, USA

    USGS Publications Warehouse

    Cunningham, K.J.

    2004-01-01

    This paper presents examples of ground-penetrating radar (GPR) data from two study sites in southeastern Florida where karstic Pleistocene platform carbonates that comprise the unconfined Biscayne aquifer were imaged. Important features shown on resultant GPR profiles include: (1) upward and lateral qualitative interpretative distribution of porosity and hydraulic conductivity; (2) paleotopographic relief on karstic subaerial exposure surfaces; and (3) vertical stacking of chronostratigraphic high-frequency cycles (HFCs). These characteristics were verified by comparison to rock properties observed and measured in core samples, and identified in digital optical borehole images. Results demonstrate that an empirical relation exists between measured whole-core porosity and hydraulic conductivity, observed porosity on digital optical borehole images, formation conductivity, and GPR reflection amplitudes-as porosity and hydraulic conductivity determined from core and borehole images increases, formation conductivity increases, and GPR reflection amplitude decreases. This relation allows for qualitative interpretation of the vertical and lateral distribution of porosity and hydraulic conductivity within HFCs. Two subtidal HFCs in the uppermost Biscayne aquifer have significantly unique populations of whole-core porosity values and vertical hydraulic conductivity values. Porosity measurements from one cycle has a median value about two to three times greater than the values from the other HFC, and median values of vertical hydraulic-conductivity about three orders of magnitude higher than the other HFC. The HFC with the higher porosity and hydraulic conductivity values is shown as a discrete package of relatively low-amplitude reflections, whereas the HFC characterized by lower porosity and hydraulic-conductivity measurements is expressed by higher amplitude reflections. Porosity and hydraulic-conductivity values measured from whole-core samples, and vuggy porosity

  19. Isolation of intact astrocytes from the optic nerve head of adult mice.

    PubMed

    Choi, Hee Joo; Sun, Daniel; Jakobs, Tatjana C

    2015-08-01

    The astrocytes of the optic nerve head are a specialized subtype of white matter astrocytes that form the direct cellular environment of the unmyelinated ganglion cell axons. Due to their potential involvement in glaucoma, these astrocytes have become a target of research. Due to the heterogeneity of the optic nerve tissue, which also contains other cell types, in some cases it may be desirable to conduct gene expression studies on small numbers of well-characterized astrocytes or even individual cells. Here, we describe a simple method to isolate individual astrocytes. This method permits obtaining astrocytes with intact morphology from the adult mouse optic nerve and reduces contamination of the isolated astrocytes by other cell types. Individual astrocytes can be recognized by their morphology and collected under microscopic control. The whole procedure can be completed in 2-3 h. We also discuss downstream applications like multiplex single-cell PCR and quantitative PCR (qPCR).

  20. Genetic testing in Tunisian families with heritable retinoblastoma using a low cost approach permits accurate risk prediction in relatives and reveals incomplete penetrance in adults.

    PubMed

    Ayari Jeridi, Hajer; Bouguila, Hédi; Ansperger-Rescher, Birgit; Baroudi, Olfa; Mdimegh, Imen; Omran, Ines; Charradi, Khaoula; Bouzayene, Hssan; Benammar-Elgaaïed, Amel; Lohmann, Dietmar R

    2014-07-01

    Heritable retinoblastoma is caused by oncogenic mutations in the RB1 tumor suppressor gene. Identification of these mutations in patients is important for genetic counseling and clinical management of relatives at risk. In order to lower analytical efforts, we designed a stepwise mutation detection strategy that was adapted to the spectrum of oncogenic RB1 gene mutations. We applied this strategy on 20 unrelated patients with familial and/or de novo bilateral retinoblastoma from Tunisia. In 19 (95%) patients, we detected oncogenic mutations including base substitutions, small length mutations, and large deletions. Further analyses on the origin of the mutations showed mutational mosaicism in one unilaterally affected father of a bilateral proband and incomplete penetrance in two mothers. In a large family with several retinoblastoma patients, the mutation identified in the index patient was also detected in several non-penetrant relatives. RNA analyses showed that this mutation results in an in-frame loss of exon 9. In summary, our strategy can serve as a model for RB1 mutation identification with high analytical sensitivity. Our results point out that genetic testing is needed to reveal or exclude incomplete penetrance specifically in parents of patients with sporadic disease.

  1. Penetration of concrete targets

    SciTech Connect

    Forrestal, M.J.; Cargile, J.D.; Tzou, R.D.Y.

    1993-08-01

    We developed penetration equations for ogive-nosed projectiles that penetrated concrete targets after normal impact. Our penetration equations predict axial force on the projectile nose, rigid-body motion, and final penetration depth. For target constitutive models, we conducted triaxial material experiments to confining pressures of 600 MPa and curve-fit these data with a linear pressure-volumetric strain relation and with a linear Mohr-Coulomb, shear strength-pressure relation. To verify our penetration equations, we conducted eleven penetration experiments with 0.90 kg, 26.9-mm-diameter, ogive-nosed projectiles into 1.37-m-diameter concrete targets with unconfined compressive strengths between 32-40 MPa. Predictions from our penetration equation are compared with final penetration depth measurements for striking velocities between 280--800 m/s.

  2. Bilateral simultaneous optic neuropathy in adults: clinical, imaging, serological, and genetic studies.

    PubMed Central

    Morrissey, S P; Borruat, F X; Miller, D H; Moseley, I F; Sweeney, M G; Govan, G G; Kelly, M A; Francis, D A; Harding, A E; McDonald, W I

    1995-01-01

    To elucidate the cause(s) of acute or subacute bilateral simultaneous optic neuropathy (BSON) in adult life, a follow up study of 23 patients was performed with clinical assessment, brain MRI, HLA typing, and mitochondrial DNA analysis. The results of CSF electrophoresis were available from previous investigations in 11 patients. At follow up, five (22%) had developed clinically definite multiple sclerosis, four (17%) had mitochondrial DNA point mutations indicating a diagnosis of Leber's hereditary optic neuropathy (LHON). The remaining 14 patients (61%) still had clinically isolated BSON a mean of 50 months after the onset of visual symptoms: three of 14 (21%) had multiple MRI white matter lesions compatible with multiple sclerosis, three of 14 (21%) had the multiple sclerosis associated HLA-DR15/DQw6 haplotype, and one of seven tested had CSF oligoclonal IgG bands; in total only five (36%) had one or more of these risk factors. The low frequency of risk factors for the development of multiple sclerosis in these 14 patients suggests that few will develop multiple sclerosis with more prolonged follow up. It is concluded that: (a) about 20% of cases of BSON without affected relatives are due to LHON; (b) multiple sclerosis develops after BSON in at least 20% of cases, but the long term conversion rate is likely to be considerably less than the rate of over 70% seen after an episode of acute unilateral optic neuritis in adult life. PMID:7823072

  3. FAA fluorescent penetrant activities

    SciTech Connect

    Moore, D.G.; Larson, B.F.

    1997-11-01

    The Federal Aviation Administration`s Airworthiness Assurance NDI Validation Center (AANC) and the Center for Aviation Systems Reliability (CASR) are currently working to develop a liquid penetrant inspection (LPI) system evaluation capability that will support the needs of the penetrant manufacturers, commercial airline industry and the FAA. The main focus of this facility is to support the evaluation of penetrant inspection materials, penetrant systems and to apply resources to support industry needs. This paper discusses efforts to create such a facility and an initial project to produce fatigue crack specimens for evaluation of Type 1 penetrant sensitivities.

  4. A new type of Schwann cell graft transplantation to promote optic nerve regeneration in adult rats.

    PubMed

    Fang, Yuan; Mo, Xiaofen; Guo, Wenyi; Zhang, Meng; Zhang, Peihua; Wang, Yan; Rong, Xianfang; Tian, Jie; Sun, Xinghuai

    2010-12-01

    Like other parts of the central nervous system, the adult mammalian optic nerve is difficult to regenerate after injury. Transplantation of the peripheral nerve or a Schwann cell (SC) graft can promote injured axonal regrowth. We tried to develop a new type of tissue-engineered SC graft that consisted of SCs seeded onto a poly(lactic-co-glycolic acid)/chitosan conduit. Meanwhile, SCs were transfected along the ciliary neurotrophic factor (CNTF) gene in vitro by electroporation to increase their neurotrophic effect. Four weeks after transplantation, GAP-43 labelled regenerating axons were found in the SC grafts, and axons in the CNTF-SC graft were longer than those in the SC graft. Tissue-engineered SC grafts can provide a feasible environment for optic nerve regeneration and may become an alternative for bridging damaged nerves and repairing nerve defects in the future.

  5. Assessment of optic disc parameters among healthy adult Malays by Heidelberg Retinal Tomograph II.

    PubMed

    Jusoh, Shawarinin; Shaharuddin, Bakiah; Wan Hitam, Wan H

    2011-01-01

    This study aims to assess the optic disc characteristics in healthy adult Malays and to correlate them with age, gender and refractive errors. Cross-sectional study. A total of 200 voluntary participants (106 women and 94 men) among Malay students aged 20 to 37 years at Health Campus, Universiti Sains Malaysia. The relationship between Heidelberg Retinal Tomograph parameters with age, gender and refractive error were analysed with correlation tests and multiple linear regression analyses.   Twelve parameters, that is, disc area, rim area, cup area, cup to disc area, cup volume, rim volume, height variation contour, cup shape measure, mean cup depth, maximum cup depth, mean retinal nerve fibre layer thickness and retinal nerve fibre layer cross-sectional area.   Disc area, rim area and cup : disc area ratio averaged 2.24 ± 0.52 (mean ± standard deviation), 1.64 ± 0.32 and 0.25 ± 0.12 mm(2) , respectively. Five parameters (disc area, cup area, cup volume, cup : disc area ratio and mean retinal nerve fibre layer thickness) showed statistically significant difference between men and women. Age was negatively and significantly correlated with rim area with coefficient r = -0.21, P = 0.003. All optic disc parameters were significantly correlated (P < 0.05) with disc area, except cup shape measure.   One or more of optic disc parameters were affected significantly by age, gender and disc area in healthy adult Malays' eyes. These factors need to be considered during the evaluation of optic disc. © 2010 The Authors. Clinical and Experimental Ophthalmology © 2010 Royal Australian and New Zealand College of Ophthalmologists.

  6. Applications of hybrid diffuse optics for clinical management of adults after brain injury

    NASA Astrophysics Data System (ADS)

    Kim, Meeri Nam

    Information about cerebral blood flow (CBF) is valuable for clinical management of patients after severe brain injury. Unfortunately, current modalities for monitoring brain are often limited by hurdles that include high cost, low throughput, exposure to ionizing radiation, probe invasiveness, and increased risk to critically ill patients when transportation out of their room or unit is required. A further limitation of current technologies is an inability to provide continuous bedside measurements that are often desirable for unstable patients. Here we explore the clinical utility of diffuse correlation spectroscopy (DCS) as an alternative approach for bedside CBF monitoring. DCS uses the rapid intensity fluctuations of near-infrared light to derive a continuous measure of changes in blood flow without ionizing radiation or invasive probing. Concurrently, we employ another optical technique, called diffuse optical spectroscopy (DOS), to derive changes in cerebral oxyhemoglobin ( HbO2) and deoxyhemoglobin (Hb) concentrations. Our clinical studies integrate DCS with DOS into a single hybrid instrument that simultaneously monitors CBF and HbO2/Hb in the injured adult brain. The first parts of this dissertation present the motivations for monitoring blood flow in injured brain, as well as the theory underlying diffuse optics technology. The next section elaborates on details of the hybrid instrumentation. The final chapters describe four human subject studies carried out with these methods. Each of these studies investigates an aspect of the potential of the hybrid monitor in clinical applications involving adult brain. The studies include: (1) validation of DCS-measured CBF against xenon-enhanced computed tomography in brain-injured adults; (2) a study of the effects of age and gender on posture-change-induced CBF variation in healthy subjects; (3) a study of the efficacy of DCS/DOS for monitoring neurocritical care patients during various medical interventions such

  7. Chemical penetration enhancers.

    PubMed

    Newton, Stephen J

    2013-01-01

    Chemical penetration enhancers are utilized in topical preparations as a method for enhancing permeation of drugs across the skin. In particular, they are utilized for transdermal delivery of medications in an attempt to produce a systemic response, to avoid first-pass metabolism, and to decrease the gastrointestinal transit time observed with oral medications. A review of the selection of chemical penetration enhancers, their mechanism of action, the most common chemical penetration enhancers in each class, and alternatives will be discussed in detail.

  8. Full penetration detection in Nd:YAG laser welding by analysis of oscillatory optical signals: application to overlap weld-seam tracking

    NASA Astrophysics Data System (ADS)

    Hand, Duncan P.; Haran, Frank M.; Jones, Julian D. C.; Peters, Christopher

    1997-04-01

    We describe a non-intrusive optical sensor for process monitoring of Nd:YAG laser welding, using light returned through the core of the power delivery optical fiber. This sensor is referred to as the core power monitor (core PM), and uses the delivery fiber to collect the broadband light generated in the process, which is then divided into spectral bands (designated as UV/visible and IR). These optical signals exhibit a characteristic oscillatory intensity modulation within the frequency range 2 - 5 kHz, which is believed to arise from a combination of keyhole, and weld pool oscillations. The frequency content may be related to the size and shape of the welding keyhole, and an alarm system for overlap weeding has been developed based on this principle. This can detect both misalignment of the focused laser spot off the seam, and any excessive gap between the plates.

  9. Morphometric analysis of infant and adult medullary nuclei through optical disector method.

    PubMed

    Porzionato, Andrea; Macchi, Veronica; Parenti, Anna; De Caro, Raffaele

    2009-10-01

    In the literature, comprehensive and comparative morphometric studies of infant and adult medullary nuclei performed with unbiased methods are still lacking. In this study, the unbiased quantitative method of the optical disector was applied to analyze neuronal densities, nuclear volumes, and total neuron numbers of the hypoglossal nucleus (XII), dorsal motor nucleus of the vagus (DMNV), nucleus tractus solitarii (NTS), medial vestibular nucleus (MedVe), cuneate nucleus (Cu), nucleus of the spinal trigeminal tract, principal inferior olivary nucleus (PION), medial inferior olivary nucleus (MION), and dorsal inferior olivary nucleus (DION) in adults (16 male, six female; mean age: 37 years) and infants (five male, five female; mean age: 5 months). In both infants and adults, higher neuronal densities were found in the more ventrally located nuclei of the spinal trigeminal tract (mean values (coefficient of variation): 20,947 (0.29) and 8,990 (0.18) neurons/mm(3), respectively) and inferior olivary complex (PION: 20,010 (0.15) and 9,076 (0.10); MION: 18,667 (0.20) and 9,989 (0.13); DION: 22,424 (0.17) and 10,986 (0.20), respectively) than in the nuclei of the medullary tegmentum, that is, XII (2,747 (0.39) and 1,026 (0.31)), DMNV (2,876 (0.19) and 1,553 (0.26)), NTS (7,993 (0.17) and 2,877 (0.13)), MedVe (7,010 (0.17) and 2,918 (0.12)), and Cu (2,563 (0.23) and 1,038 (0.16)). All the medullary nuclei showed higher volumes and lower neuronal densities in adults than in infants, without statistically significant differences in total neuron numbers, probably because of postnatal development of the neuropil and microvascularization.

  10. Follicular penetration and targeting.

    PubMed

    Lademann, Jürgen; Otberg, Nina; Jacobi, Ute; Hoffman, Robert M; Blume-Peytavi, Ulrike

    2005-12-01

    In the past, intercellular penetration was assumed to be the most important penetration pathway of topically applied substances. First hints that follicular penetration needs to be taken into consideration were confirmed by recent investigations, presented during the workshop "Follicular Penetration and Targeting" at the 4th Intercontinental Meeting of Hair Research Societies", in Berlin 2004. Hair follicles represent an efficient reservoir for the penetration of topically applied substances with subsequent targeting of distinct cell populations, e.g., nestin-expressing follicular bulge cells. The volume of this reservoir can be determined by differential stripping technology. The follicular penetration processes are significantly influenced by the state of the follicular infundibulum; recent experimental investigations could demonstrate that it is essential to distinguish between open and closed hair follicles. Topically applied substances can only penetrate into open hair follicle. Knowledge of follicular penetration is of high clinical relevance for functional targeting of distinct follicular regions. Human hair follicles show a hair-cycle-dependent variation of the dense neuronal and vascular network. Moreover, during hair follicle cycling with initiation of anagen, newly formed vessels occur. Thus, the potential of nestin-expressing hair follicle stem cells to form neurons and blood vessels was investigated.

  11. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  12. Thermomechanics of Impact & Penetration

    DTIC Science & Technology

    2005-09-30

    metallic projectiles into granular targets, at high striking velocities, formulate appropriate constitutive models , and solve selected problems by...constitutive models (preliminary work only) * Multiscale Numerical Simulations (preliminary work) PROGRESS Time-Dependent Penetration Path of...theory. A dislocation based plasticity model was also developed for the impact and penetration analysis. Numerical solutions were presented for selected

  13. New Insights in Vanishing White Matter Disease-Isolated Bilateral Optic Neuropathy in Adult Onset Disease.

    PubMed

    Barros, Sandra R; Parreira, Sónia C R; Miranda, Ana F B; Pereira, Ana M B; Campos, Nuno M P

    2017-09-07

    Vanishing white matter disease (VWMD) is a rare disease affecting cerebral white matter. The adult form is even rarer and manifests with motor symptoms, behavioral problems, and dementia. There is no treatment and progression is inevitable. We describe a case with atypical manifestations and an unusual course. Description of a 42-year-old man with VWMD complaining of progressive visual loss in the right eye. The patient's visual acuity was 20/60, right eye, and 20/25, left eye, with pale optic nerves bilaterally. MRI showed atrophy of the corpus callosum, diffuse rarefaction of cerebral white matter including the anterior and posterior visual pathways. Our patient had no further symptoms besides loss of visual acuity, which is rare in patients with VWMD of the same age and genetic mutation.

  14. Mapping cerebral pulse pressure and arterial compliance over the adult lifespan with optical imaging.

    PubMed

    Tan, Chin Hong; Low, Kathy A; Kong, Tania; Fletcher, Mark A; Zimmerman, Benjamin; Maclin, Edward L; Chiarelli, Antonio M; Gratton, Gabriele; Fabiani, Monica

    2017-01-01

    Cerebrovascular health is important for maintaining a high level of cognitive performance, not only in old age, but also throughout the lifespan. Recently, it was first demonstrated that diffuse optical imaging measures of pulse amplitude and arterial compliance can provide estimates of cerebral arterial health throughout the cortex, and were associated with age, estimated cardiorespiratory fitness (eCRF), neuroanatomy and cognitive function in older adults (aged 55-87). The current study replicates and extends the original findings using a broader age range (a new adult sample aged 18-75), longer recording periods (360 s), and a more extensive optical montage (1536 channels). These methodological improvements represent a 5-fold increase in recording time and a 4-fold increase in coverage compared to the initial study. Results show that reliability for both pulse amplitude and compliance measures across recording blocks was very high (r(45) = .99 and .75, respectively). Pulse amplitude and pulse pressure were shown to correlate with age across the broader age range. We also found correlations between arterial health and both cortical and subcortical gray matter volumes. Additionally, we replicated the correlations between arterial compliance and age, eCRF, global brain atrophy, and cognitive flexibility. New regional analyses revealed that higher performance on the operation span (OSPAN) working memory task was associated with greater localized arterial compliance in frontoparietal cortex, but not with global arterial compliance. Further, greater arterial compliance in frontoparietal regions was associated with younger age and higher eCRF. These associations were not present in the visual cortex. The current study not only replicates the initial one in a sample including a much wider age range, but also provides new evidence showing that frontoparietal regions may be especially vulnerable to vascular degeneration during brain aging, with potential functional

  15. Mapping cerebral pulse pressure and arterial compliance over the adult lifespan with optical imaging

    PubMed Central

    Tan, Chin Hong; Low, Kathy A.; Kong, Tania; Fletcher, Mark A.; Zimmerman, Benjamin; Maclin, Edward L.; Chiarelli, Antonio M.; Gratton, Gabriele

    2017-01-01

    Cerebrovascular health is important for maintaining a high level of cognitive performance, not only in old age, but also throughout the lifespan. Recently, it was first demonstrated that diffuse optical imaging measures of pulse amplitude and arterial compliance can provide estimates of cerebral arterial health throughout the cortex, and were associated with age, estimated cardiorespiratory fitness (eCRF), neuroanatomy and cognitive function in older adults (aged 55–87). The current study replicates and extends the original findings using a broader age range (a new adult sample aged 18–75), longer recording periods (360 s), and a more extensive optical montage (1536 channels). These methodological improvements represent a 5-fold increase in recording time and a 4-fold increase in coverage compared to the initial study. Results show that reliability for both pulse amplitude and compliance measures across recording blocks was very high (r(45) = .99 and .75, respectively). Pulse amplitude and pulse pressure were shown to correlate with age across the broader age range. We also found correlations between arterial health and both cortical and subcortical gray matter volumes. Additionally, we replicated the correlations between arterial compliance and age, eCRF, global brain atrophy, and cognitive flexibility. New regional analyses revealed that higher performance on the operation span (OSPAN) working memory task was associated with greater localized arterial compliance in frontoparietal cortex, but not with global arterial compliance. Further, greater arterial compliance in frontoparietal regions was associated with younger age and higher eCRF. These associations were not present in the visual cortex. The current study not only replicates the initial one in a sample including a much wider age range, but also provides new evidence showing that frontoparietal regions may be especially vulnerable to vascular degeneration during brain aging, with potential functional

  16. Upregulation of Gem relates to retinal ganglion cells apoptosis after optic nerve crush in adult rats.

    PubMed

    Xu, Fan; Huang, Hui; Wu, Yu; Lu, Lu; Jiang, Li; Chen, Lifei; Zeng, Siming; Li, Li; Li, Min

    2014-10-01

    GTP-binding protein Gem, a member protein of the Ras superfamily, can regulate actin cytoskeleton reorganization mediated by Rho-associated coiled-coil-containing protein kinase (ROCK). One attractive activity of the ROCK is playing a potential role in physiological and pathological process in retinal ganglion cells (RGCs) apoptosis. However, the function of Gem in retina is still with limited understanding. To investigate whether Gem is involved in optic nerve injury, we performed an optic nerve crush (ONC) model in adult rats. Western blot analysis indicated that Gem was significantly increased in the retina at the 3rd day after ONC. Meanwhile, double-immunofluorescent staining showed that Gem expression was mainly up-regulated in ganglion cell layer and co-localized with NeuN (a marker of RGCs). Additionally, the co-localizations of Gem/active-caspase-3 and Gem/TUNEL-positive cells were detected in RGCs. Furthermore, the expression of active-caspase-3 and TUNEL-positive cells was parallel with that of Gem. Finally, expression pattern of ROCK family (only ROCK2 but not ROCK1) was increased in the differentiated process, which was collected with the expression of GEM and active-caspase-3. Based on the present results, it is suggested that Gem might play a crucial role in RGCs apoptosis after ONC, which might be involved in ROCK pathway.

  17. Quantitative in vivo optical tomography of cancer progression & vasculature development in adult zebrafish

    PubMed Central

    Kumar, Sunil; Lockwood, Nicola; Ramel, Marie-Christine; Correia, Teresa; Ellis, Matthew; Alexandrov, Yuriy; Andrews, Natalie; Patel, Rachel; Bugeon, Laurence; Dallman, Margaret J.; Brandner, Sebastian; Arridge, Simon; Katan, Matilda; McGinty, James; Frankel, Paul; French, Paul M.W.

    2016-01-01

    We describe a novel approach to study tumour progression and vasculature development in vivo via global 3-D fluorescence imaging of live non-pigmented adult zebrafish utilising angularly multiplexed optical projection tomography with compressive sensing (CS-OPT). This “mesoscopic” imaging method bridges a gap between established ~μm resolution 3-D fluorescence microscopy techniques and ~mm-resolved whole body planar imaging and diffuse tomography. Implementing angular multiplexing with CS-OPT, we demonstrate the in vivo global imaging of an inducible fluorescently labelled genetic model of liver cancer in adult non-pigmented zebrafish that also present fluorescently labelled vasculature. In this disease model, addition of a chemical inducer (doxycycline) drives expression of eGFP tagged oncogenic K-RASV12 in the liver of immune competent animals. We show that our novel in vivo global imaging methodology enables non-invasive quantitative imaging of the development of tumour and vasculature throughout the progression of the disease, which we have validated against established methods of pathology including immunohistochemistry. We have also demonstrated its potential for longitudinal imaging through a study of vascular development in the same zebrafish from early embryo to adulthood. We believe that this instrument, together with its associated analysis and data management tools, constitute a new platform for in vivo cancer studies and drug discovery in zebrafish disease models. PMID:27259259

  18. Quantitative in vivo optical tomography of cancer progression & vasculature development in adult zebrafish.

    PubMed

    Kumar, Sunil; Lockwood, Nicola; Ramel, Marie-Christine; Correia, Teresa; Ellis, Matthew; Alexandrov, Yuriy; Andrews, Natalie; Patel, Rachel; Bugeon, Laurence; Dallman, Margaret J; Brandner, Sebastian; Arridge, Simon; Katan, Matilda; McGinty, James; Frankel, Paul; French, Paul M W

    2016-07-12

    We describe a novel approach to study tumour progression and vasculature development in vivo via global 3-D fluorescence imaging of live non-pigmented adult zebrafish utilising angularly multiplexed optical projection tomography with compressive sensing (CS-OPT). This "mesoscopic" imaging method bridges a gap between established ~μm resolution 3-D fluorescence microscopy techniques and ~mm-resolved whole body planar imaging and diffuse tomography. Implementing angular multiplexing with CS-OPT, we demonstrate the in vivo global imaging of an inducible fluorescently labelled genetic model of liver cancer in adult non-pigmented zebrafish that also present fluorescently labelled vasculature. In this disease model, addition of a chemical inducer (doxycycline) drives expression of eGFP tagged oncogenic K-RASV12 in the liver of immune competent animals. We show that our novel in vivo global imaging methodology enables non-invasive quantitative imaging of the development of tumour and vasculature throughout the progression of the disease, which we have validated against established methods of pathology including immunohistochemistry. We have also demonstrated its potential for longitudinal imaging through a study of vascular development in the same zebrafish from early embryo to adulthood. We believe that this instrument, together with its associated analysis and data management tools, constitute a new platform for in vivo cancer studies and drug discovery in zebrafish disease models.

  19. Penetrating the "zone of avoidance:. IV. an optical survey for hidden galaxies in the region 130d <= L <= 180d, -5d <= B <= +5d.

    NASA Astrophysics Data System (ADS)

    Saurer, W.; Seeberger, R.; Weinberger, R.

    1997-12-01

    As the fourth part in a series of papers on galaxies in the "zone of avoidance" (ZOA) of the Milky Way we present a compilation of 1067 galaxies discovered during a systematic search on Palomar Observatory Sky Survey I (POSS I) red-sensitive prints. The region searched comprises 500 square degrees, at 130d <= l <= 180d, -5d <= b <= +5d. In addition to galactic and equatorial coordinates, we list maximum and minimum optical diameters derived from both the red- and blue-sensitive prints and made cross checks with the IRAS PSC catalogue. An asymmetric distribution of the galaxies with respect to the galactic equator is found and is compared to the locations of optically visible dust clouds and/or the distribution of IR-emitting dust material. There is a pronounced bridge of galaxies across the galactic plane at l ~160d which will be discussed according to recent results on the extension of the Pisces-Perseus supercluster. Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

  20. Advanced Penetrator Materials

    DTIC Science & Technology

    2007-11-02

    development • Uranium (U-V-X) Alloys • Alternative Matrix (adiabatic shearing) Tungsten Composites • Amorphous and Nanocrystalline Alloys • Severe Deformation...WIDER CHANNEL • MUSHROOM NOSE • LESS DEPTH • REMAINS SHARP • NARROW CHANNEL • DEEPER CAVITY TUNGSTEN HEAVY ALLOY U-3/4 Ti ALLOY U-8Mo ALLOYW-Ni-Fe...martensite (from Staker)(from Staker) • U-V alloys have the potential to maintain penetration capability while reducing penetrator density and mass. Tungsten

  1. Retinal nerve fiber layer thickness measurements of normal Northern Nigerian adults using optical coherence tomography.

    PubMed

    Sani, Rabi Yahaya; Abdu, Lawal; Pam, Victoria

    2016-01-01

    To assess retinal nerve fiber layer (RNFL) thickness measurements of normal Northern Nigerian adults using optical coherence tomography (OCT). The OCT procedure was carried out with the Carl Zeiss Stratus OCT Model 3000 software version 4.0 (Carl Zeiss Meditec AG, Jena, Germany). The fast RNFL scan protocol was used to obtain RNFL thickness measurements. Student's t-test was used to compare mean RNFL thickness values. P ≤ 0.05 was considered as statistically significant. Average RNFL thickness was correlated with age. Two hundred and twenty eyes of 110 subjects aged 18-51 years were examined. The average RNFL thickness was 104.17 ± 10.71 μm. The mean values for the RNFL thickness were 129.15 ± 16.87 μm, 135.34 ± 20.40 μm, 85.10 ± 23.60 μm, and 67.19 ± 13.27 μm for the inferior, superior, nasal, and temporal quadrants, respectively. A statistically significant difference was found between males and females for the mean RNFL thickness (t = 3.30, P = 0.001) and for the mean superior and inferior RNFL thickness. There was a statistically significant difference between right and left eyes (t = 3.73, P = 0.001) for the mean RNFL thickness. A negative correlation was found between RNFL thickness and age (r = -0.313, P = 0.002). Normal RNFL thickness measurements in healthy Nigerian adults are presented. The RNFL was found to be thicker in females and in right eyes. The values were comparable to those of the Indian population but higher than some Caucasian values.

  2. Retinal nerve fiber layer thickness measurements of normal Northern Nigerian adults using optical coherence tomography

    PubMed Central

    Sani, Rabi Yahaya; Abdu, Lawal; Pam, Victoria

    2016-01-01

    Objective: To assess retinal nerve fiber layer (RNFL) thickness measurements of normal Northern Nigerian adults using optical coherence tomography (OCT). Subjects and Methods: The OCT procedure was carried out with the Carl Zeiss Stratus OCT Model 3000 software version 4.0 (Carl Zeiss Meditec AG, Jena, Germany). The fast RNFL scan protocol was used to obtain RNFL thickness measurements. Student's t-test was used to compare mean RNFL thickness values. P ≤ 0.05 was considered as statistically significant. Average RNFL thickness was correlated with age. Results: Two hundred and twenty eyes of 110 subjects aged 18–51 years were examined. The average RNFL thickness was 104.17 ± 10.71 μm. The mean values for the RNFL thickness were 129.15 ± 16.87 μm, 135.34 ± 20.40 μm, 85.10 ± 23.60 μm, and 67.19 ± 13.27 μm for the inferior, superior, nasal, and temporal quadrants, respectively. A statistically significant difference was found between males and females for the mean RNFL thickness (t = 3.30, P = 0.001) and for the mean superior and inferior RNFL thickness. There was a statistically significant difference between right and left eyes (t = 3.73, P = 0.001) for the mean RNFL thickness. A negative correlation was found between RNFL thickness and age (r = −0.313, P = 0.002). Conclusion: Normal RNFL thickness measurements in healthy Nigerian adults are presented. The RNFL was found to be thicker in females and in right eyes. The values were comparable to those of the Indian population but higher than some Caucasian values. PMID:27044727

  3. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  4. Inherited mitochondrial optic neuropathies

    PubMed Central

    Yu-Wai-Man, P; Griffiths, P G; Hudson, G; Chinnery, P F

    2009-01-01

    Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (DOA) are the two most common inherited optic neuropathies and they result in significant visual morbidity among young adults. Both disorders are the result of mitochondrial dysfunction: LHON from primary mitochondrial DNA (mtDNA) mutations affecting the respiratory chain complexes; and the majority of DOA families have mutations in the OPA1 gene, which codes for an inner mitochondrial membrane protein critical for mtDNA maintenance and oxidative phosphorylation. Additional genetic and environmental factors modulate the penetrance of LHON, and the same is likely to be the case for DOA which has a markedly variable clinical phenotype. The selective vulnerability of retinal ganglion cells (RGCs) is a key pathological feature and understanding the fundamental mechanisms that underlie RGC loss in these disorders is a prerequisite for the development of effective therapeutic strategies which are currently limited. PMID:19001017

  5. Maintenance of Glia in the Optic Lamina Is Mediated by EGFR Signaling by Photoreceptors in Adult Drosophila

    PubMed Central

    Lee, Yuan-Ming; Sun, Y. Henry

    2015-01-01

    The late onset of neurodegeneration in humans indicates that the survival and function of cells in the nervous system must be maintained throughout adulthood. In the optic lamina of the adult Drosophila, the photoreceptor axons are surrounded by multiple types of glia. We demonstrated that the adult photoreceptors actively contribute to glia maintenance in their target field within the optic lamina. This effect is dependent on the epidermal growth factor receptor (EGFR) ligands produced by the R1-6 photoreceptors and transported to the optic lamina to act on EGFR in the lamina glia. EGFR signaling is necessary and sufficient to act in a cell-autonomous manner in the lamina glia. Our results suggest that EGFR signaling is required for the trafficking of the autophagosome/endosome to the lysosome. The loss of EGFR signaling results in cell degeneration most likely because of the accumulation of autophagosomes. Our findings provide in vivo evidence for the role of adult neurons in the maintenance of glia and a novel role for EGFR signaling in the autophagic flux. PMID:25909451

  6. Microencapsulated Fluorescent Dye Penetrant.

    DTIC Science & Technology

    1979-07-01

    Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

  7. Penetration resistant barrier

    DOEpatents

    Hoover, William R.; Mead, Keith E.; Street, Henry K.

    1977-01-01

    The disclosure relates to a barrier for resisting penetration by such as hand tools and oxy-acetylene cutting torches. The barrier comprises a layer of firebrick, which is preferably epoxy impregnated sandwiched between inner and outer layers of steel. Between the firebrick and steel are layers of resilient rubber-like filler.

  8. Soil penetrometers and penetrability

    USDA-ARS?s Scientific Manuscript database

    Soil penetrometers are useful tools that measure the penetrability, or strength, of a soil. They can be as simple as a rod or shaft with a blunt or sharp end, or complicated mechanically driven instruments with digital data collection systems. Regardless of their design, soil penetrometers measure s...

  9. Single wall penetration equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    1991-01-01

    Five single plate penetration equations are compared for accuracy and effectiveness. These five equations are two well-known equations (Fish-Summers and Schmidt-Holsapple), two equations developed by the Apollo project (Rockwell and Johnson Space Center (JSC), and one recently revised from JSC (Cour-Palais). They were derived from test results, with velocities ranging up to 8 km/s. Microsoft Excel software was used to construct a spreadsheet to calculate the diameters and masses of projectiles for various velocities, varying the material properties of both projectile and target for the five single plate penetration equations. The results were plotted on diameter versus velocity graphs for ballistic and spallation limits using Cricket Graph software, for velocities ranging from 2 to 15 km/s defined for the orbital debris. First, these equations were compared to each other, then each equation was compared with various aluminum projectile densities. Finally, these equations were compared with test results performed at JSC for the Marshall Space Flight Center. These equations predict a wide variety of projectile diameters at a given velocity. Thus, it is very difficult to choose the 'right' prediction equation. The thickness of a single plate could have a large variation by choosing a different penetration equation. Even though all five equations are empirically developed with various materials, especially for aluminum alloys, one cannot be confident in the shield design with the predictions obtained by the penetration equations without verifying by tests.

  10. Frequency analysis of the visual steady-state response measured with the fast optical signal in younger and older adults

    PubMed Central

    Tse, Chun-Yu; Gordon, Brian A.; Fabiani, Monica; Gratton, Gabriele

    2010-01-01

    Relatively high frequency activity (>4 Hz) carries important information about the state of the brain or its response to high frequency events. The electroencephalogram (EEG) is commonly used to study these changes because it possesses high temporal resolution and a good signal-to-noise ratio. However, it provides limited spatial information. Non-invasive fast optical signals (FOS) have been proposed as a neuroimaging tool combining spatial and temporal resolution. Yet, this technique has not been applied to study high frequency brain oscillations because of its relatively low signal-to-noise ratio. Here we investigate the sensitivity of FOS to relatively high-frequency brain oscillations. We measured the steady-state optical response elicited in medial and lateral occipital cortex by checkerboard reversals occurring at 4, 6, and 8 Hz in younger and older adults. Stimulus-dependent oscillations were observed at the predicted stimulation frequency. In addition, in the younger adults the FOS steady-state response was smaller in lateral than medial areas, whereas in the older adults it was reversed in these two cortical regions. This may reflect diminished top-down inhibitory control in the older adults. The results indicate that FOS can be used to study the modulation of relatively high-frequency brain oscillations in adjacent cortical regions. PMID:20566389

  11. Corrosion Inhibitors as Penetrant Dyes for Radiography

    NASA Technical Reports Server (NTRS)

    Novak, Howard L.; Hall, Phillip B.

    2003-01-01

    Liquid/vapor-phase corrosion inhibitors (LVCIs) have been found to be additionally useful as penetrant dyes for neutron radiography (and perhaps also x-radiography). Enhancement of radiographic contrasts by use of LVCIs can reveal cracks, corrosion, and other defects that may be undetectable by ultrasonic inspection, that are hidden from direct optical inspection, and/or that are difficult or impossible to detect in radiographs made without dyes.

  12. Penetrating craniofacial arrow injury.

    PubMed

    Jain, Dk; Aggarwal, Gaurav; Lubana, Ps; Moses, Sonia

    2010-01-01

    Arrow injuries are an extinct form of injury in most parts of the developed world, but are still seen, albeit infrequently in developing countries. Reports of penetrating injuries of the craniofacial region secondary to projectiles are few and far between. The morbidity-free outcome of surgical removal, in case of penetrating arrow injuries, despite the delay in presentation and, moreover, in the emergency surgical practice, are the salient points to be remembered whilst managing such cases, for 'what the mind knows is what the eyes see and what the eyes see is what can be practiced'. We report the case of a patient who was attacked by a projectile fired from a crossbow. Immediate surgery under general anesthesia was required to remove the arrow, with utmost care to avoid any neurovascular compromise to the facial nerve, as well as minimize postoperative complications such as otitis media and subsequent meningitis.

  13. Cognitive Penetration and Attention

    PubMed Central

    Gross, Steven

    2017-01-01

    Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. PMID:28275358

  14. Optical methods for measurements of skin penetration.

    PubMed

    Gotter, B; Faubel, W; Neubert, R H H

    2008-01-01

    Fourier transform infrared photoacoustic (PAS), photothermal deflection (PDS) and Raman spectroscopy belong to the modern innovative noninvasive analytical tools that are beginning to be recognized as highly potential techniques for the noninvasive study of biological tissues and human skin under in vivo conditions. They can be applied to obtain information regarding the molecular composition of the skin down to several hundred micrometers below the skin surface. All three methods allow depth-resolved investigations. While PAS and PDS use a frequency modulation of the excitation beam to reach deeper regions in the sample, the principle of confocal Raman microspectroscopy (CRM) is a movement of the specimen in the focal plane. In consideration of depth measurements PAS and PDS complete the applicable spectrum of CRM, since Raman microscopy requires particular transparent materials.

  15. Penetration Mechanics of Composites

    DTIC Science & Technology

    1992-04-01

    distribution for tensile strength of hollow virgin filaments, based on 128 tests (source: Owens / Corning Fiberglas Corp). 14 1.2 Schematic of split Hopkinson...These were supplied by Owens / Corning Fiberglas Corporation, Granville, Ohio in two forms: 463AA750 (750 yd/lb) roving tow and G150 (1500 yd/lb...penetration of 12.7-mm thick (25-ply) GRP. Targets were fabricated by Owens Corning Fiberglas (OCF) by a licensed process designated HJ1. This complies

  16. Antibody tumor penetration

    PubMed Central

    Thurber, Greg M.; Schmidt, Michael M.; Wittrup, K. Dane

    2009-01-01

    Antibodies have proven to be effective agents in cancer imaging and therapy. One of the major challenges still facing the field is the heterogeneous distribution of these agents in tumors when administered systemically. Large regions of untargeted cells can therefore escape therapy and potentially select for more resistant cells. We present here a summary of theoretical and experimental approaches to analyze and improve antibody penetration in tumor tissue. PMID:18541331

  17. Prediction of alumina penetration

    SciTech Connect

    Mandell, D A

    1993-02-01

    The MESA hydrocode was used to predict two-dimensional tests of L/D 10 and L/D 15 tungsten rods impacting AD 90 alumina with a steel backing. The residual penetration into the steel is the measured quantity in these experiments conducted at the Southwest Research Institute (SWR). The interface velocity as a function of time between an alumina target and a lithium fluoride window, impacted by an alumina disk at velocities between 544 m/s and 2329 m/s, was also predicted. These one-dimensional flyer plate experiments were conducted at Sandia National Laboratories using Coors AD 995 alumina. The material strength and fracture models are important in the prediction of ceramic experiments. The models used in these predictions are discussed. The penetrations in the two-dimensional tests were predicted to 11.4 percent or better. In five of the six experiments, the predicted penetration depth was deeper than the measured value. This trend is expected since the calculation is based on ideal conditions. The results show that good agreement between the 1-D flyer plate data and the MESA predictions exists at the lower impact velocities, but the maximum velocity is overpredicted as the flyer plate velocity increases. At a flyer plate velocity of 2329 m/s the code overpredicted the data by 12.3 percent.

  18. [Penetrating abdominal injuries].

    PubMed

    Nesbakken, A; Pillgram-Larsen, J; Naess, F; Gerner, T; Solheim, K; Stadaas, J O; Gjøra, O

    1990-02-28

    We have reviewed the medical records of 111 patients treated for abdominal stab wounds during the period 1980-87. Our two hospitals serve a catchment area of about 450,000 people. Exploratory laparotomy was performed in 89 patients with suspected peritoneal penetration. In 16 patients the laparotomy was negative, and in 15 patients only minor injuries were noted. There were no serious complications in these 31 patients. Twenty-seven patients had thoracic wounds below the fourth intercostal space, 15 with intraabdominal injuries. The most common injuries were lacerations of the liver, the small bowel and the diaphragm. The mortality in the series was 2%. Stab wounds are infrequent in Norway, and most surgeons have limited experience of such injuries. We discuss whether to employ immediate exploratory laparotomy or selective management when the peritoneum has been penetrated. When there is no evidence of evisceration or omental protrusion, local exploration of the wound should be performed in order to confirm or exclude peritoneal penetration. Injury to the diaphragm and intraabdominal viscera should always be suspected in thoracic stab wounds below the fourth intercostal space.

  19. Mars penetrator: Subsurface science mission

    NASA Technical Reports Server (NTRS)

    Lumpkin, C. K.

    1974-01-01

    A penetrator system to emplace subsurface science on the planet Mars is described. The need for subsurface science is discussed, and the technologies for achieving successful atmospheric entry, Mars penetration, and data retrieval are presented.

  20. Optical mapping of the electrical activity of isolated adult zebrafish hearts: acute effects of temperature

    PubMed Central

    Lin, Eric; Ribeiro, Amanda; Ding, Weiguang; Hove-Madsen, Leif; Sarunic, Marinko V.; Beg, Mirza Faisal

    2014-01-01

    The zebrafish (Danio rerio) has emerged as an important model for developmental cardiovascular (CV) biology; however, little is known about the cardiac function of the adult zebrafish enabling it to be used as a model of teleost CV biology. Here, we describe electrophysiological parameters, such as heart rate (HR), action potential duration (APD), and atrioventricular (AV) delay, in the zebrafish heart over a range of physiological temperatures (18–28°C). Hearts were isolated and incubated in a potentiometric dye, RH-237, enabling electrical activity assessment in several distinct regions of the heart simultaneously. Integration of a rapid thermoelectric cooling system facilitated the investigation of acute changes in temperature on critical electrophysiological parameters in the zebrafish heart. While intrinsic HR varied considerably between fish, the ex vivo preparation exhibited impressively stable HRs and sinus rhythm for more than 5 h, with a mean HR of 158 ± 9 bpm (means ± SE; n = 20) at 28°C. Atrial and ventricular APDs at 50% repolarization (APD50) were 33 ± 1 ms and 98 ± 2 ms, respectively. Excitation originated in the atrium, and there was an AV delay of 61 ± 3 ms prior to activation of the ventricle at 28°C. APD and AV delay varied between hearts beating at unique HRs; however, APD and AV delay did not appear to be statistically dependent on intrinsic basal HR, likely due to the innate beat-to-beat variability within each heart. As hearts were cooled to 18°C (by 1°C increments), HR decreased by ∼40%, and atrial and ventricular APD50 increased by a factor of ∼3 and 2, respectively. The increase in APD with cooling was disproportionate at different levels of repolarization, indicating unique temperature sensitivities for ion currents at different phases of the action potential. The effect of temperature was more apparent at lower levels of repolarization and, as a whole, the atrial APD was the cardiac parameter most affected by acute

  1. Constructing a statistical atlas of the radii of the optic nerve and cerebrospinal fluid sheath in young healthy adults

    NASA Astrophysics Data System (ADS)

    Harrigan, Robert L.; Plassard, Andrew J.; Mawn, Louise A.; Galloway, Robert L.; Smith, Seth A.; Landman, Bennett A.

    2015-03-01

    Optic neuritis is a sudden inflammation of the optic nerve (ON) and is marked by pain on eye movement, and visual symptoms such as a decrease in visual acuity, color vision, contrast and visual field defects. The ON is closely linked with multiple sclerosis (MS) and patients have a 50% chance of developing MS within 15 years. Recent advances in multi-atlas segmentation methods have omitted volumetric assessment. In the past, measuring the size of the ON has been done by hand. We utilize a new method of automatically segmenting the ON to measure the radii of both the ON and surrounding cerebrospinal fluid (CSF) sheath to develop a normative distribution of healthy young adults. We examine this distribution for any trends and find that ON and CSF sheath radii do not vary between 20-35 years of age and between sexes. We evaluate how six patients suffering from optic neuropathy compare to this distribution of controls. We find that of these six patients, five of them qualitatively differ from the normative distribution which suggests this technique could be used in the future to distinguish between optic neuritis patients and healthy controls

  2. Regenerative and other responses to injury in the retinal stump of the optic nerve in adult albino rats: transection of the intracranial optic nerve.

    PubMed Central

    Zeng, B Y; Anderson, P N; Campbell, G; Lieberman, A R

    1995-01-01

    The response to injury of the proximal (retinal) stump of the intracranially transected optic nerve in adult rats has been studied by electron microscopy. The central part of the retinal stump of the optic nerve underwent severe ischaemic damage resulting in the formation by 3 days postoperation (dpo) of a cone-shaped region of necrotic tissue which extended from a base occupying most of the cross-sectional area of the nerve at the cut end to an apex within the intraorbital part of the nerve and only 2-3 mm from the eyeball. A mixture of apparently viable and dead or dying cells and axons was present in an intermediate zone surrounding the ischaemic core. Apparently intact nerve fibres occupied most of the periphery of the optic nerve. Small bundles of sprout-like axons were seen in the intermediate zone at 3 dpo, and by 5 dpo such sprouts were present at the periphery of the degenerative core. By 7 dpo, the sprouts were also found in the centre of the degenerative core, accompanied by astrocyte processes. The number of axonal sprouts present in the degenerative core and intermediate zone was much higher at 2 and 4 wk postoperation (wpo) than at 7 dpo, then declined gradually by 6 and 8 wpo. These results show that intracranial transection of the rat optic nerve produces extensive degeneration in the proximal stump and effectively produces an intraorbital axotomy of many retinal ganglion cells. Nevertheless, surviving axons display the ability to produce regenerative sprouts which persist for considerably longer than those produced after intraorbital injury. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 PMID:7559123

  3. Effects of low-energy He-Ne laser irradiation on posttraumatic degeneration of adult rabbit optic nerve

    SciTech Connect

    Schwartz, M.; Doron, A.; Erlich, M.; Lavie, V.; Benbasat, S.; Belkin, M.; Rochkind, S.

    1987-01-01

    Axons of the mammalian peripheral and central nervous systems degenerate after nerve injury. We have recently found that He-Ne laser irradiation may prevent some of the consequences of the injury in peripheral nerves of mammals. In the present study, the efficacy of the laser in treating injured neurons of the mammalian CNS was tested. Optic nerves of adult rabbits were exposed daily for 8-14 days to He-Ne laser irradiation (14 min, 15 mW) through the overlying muscles and skin. As a result of this treatment, the injured nerves maintained their histological integrity, which is invariably lost in injured mammalian CNS neurons.

  4. Penetrating neck traumas

    PubMed Central

    Kaczmarski, Jacek; Brzeziński, Daniel; Cieślik-Wolski, Bartosz; Kozak, Józef

    2014-01-01

    Aim of the study Aim of the study is to present our own experiences in the treatment of people suffering from penetrating neck traumas. Material and methods In the years 1996-2012, 10 patients with penetrating neck traumas were treated, including 3 women and 7 men. The patients’ age ranged from 16 to 55 (the average age being 40.7 years). In 9 cases the wound was caused by cutting or stabbing, while in one case it was inflicted by a gunshot. In 8 patients it was a single cut wound, while one patient suffered from 34 stab wounds to the neck, chest and stomach. Two cut wounds resulted from a suicide attempt. The remaining injuries were the result of a crime. Results All patients underwent immediate surgery, which involved revision of the neck wounds in 8 cases, one longitudinal sternotomy and one left-sided thoracotomy. The indications for surgery included increased subcutaneous emphysema in 5 patients, bleeding from the wound in 3 patients, and mediastinal hematoma in 2 patients. The damage assessed intraoperatively included tracheal damage in 6 patients, damage to carotid vessels in 3 patients, larynx in 2 patients, thoracic vessels in 2 patients, oesophagus in 1 patient and thyroid gland in 1 patient. In 9 patients, the treatment yielded positive results. The patient with a gunshot wound died during the surgery due to massive bleeding from the aorta. Conclusions In patients with penetrating neck wounds, early and rapid diagnostics allows one to determine the indications for surgery and prevent serious fatal complications. PMID:26336390

  5. Early decompression of the injured optic nerve reduces axonal degeneration and improves functional outcome in the adult rat.

    PubMed

    Ohlsson, Marcus; Svensson, Mikael

    2007-05-01

    The putative beneficial role of an early decompression of injured CNS tissue following trauma remains controversial. In this study, we approach this scientific query using a standardized injury of the optic nerve in adult rats. Adult Sprague-Dawley rats were subjected to a standardized optic nerve constriction injury by applying a loose ligature around the nerve for 5 min, 1, 6 or 24 h. All animals were sacrificed at 28 dpi. Viable axons distal to the injury were quantified using semithin sections, and regenerative fibers were studied using antisera to neurofilament and GAP43. Axonal degeneration and glial scar development were analyzed using Fluoro-Jade staining and anti-GFAP, respectively. Visual function was studied with visual evoked potentials (VEP). No significant differences were observed between 1 and 6 h of optic nerve compression. However, the number of viable axons analyzed with neurofilament and on semithin sections, decreased significantly between 6 and 24 h, paralleled by an increase in Fluoro-Jade labeled axonal debris (P < 0.001). GFAP-IR density was significantly higher (P < 0.001) in the 24 h compression group in comparison to 6 h. VEP showed preserved, but impaired visual function in animals subjected to compression up to 6 h, compared to an abolished cortical response at 24 h. Regenerative GAP43-positive sprouts were occasionally found distal to the lesion in animals subjected to compression up to 6 h, but not at 24 h. These findings suggest that early optic nerve decompression within hours after the initial trauma is beneficial for functional outcome.

  6. The deep penetrating nevus.

    PubMed

    Strazzula, Lauren; Senna, Maryanne Makredes; Yasuda, Mariko; Belazarian, Leah

    2014-12-01

    The deep penetrating nevus (DPN), also known as the plexiform spindle cell nevus, is a pigmented lesion that commonly arises on the head and neck in the first few decades of life. Histopathologically, the DPN is wedge-shaped and contains melanocytes that exhibit deep infiltration into the dermis. Given these features, DPN may clinically and histopathologically mimic malignant melanoma, sparking confusion about the appropriate evaluation and management of these lesions. The goal of this review is to summarize the clinical and histopathological features of DPN and to discuss diagnostic and treatment strategies for dermatologists.

  7. Penetrating thoracic trauma.

    PubMed

    Bastos, Renata; Baisden, Clinton E; Harker, Lori; Calhoon, John H

    2008-01-01

    The initial approach to penetrating thoracic trauma is directed towards the pathophysiologic syndrome upon presentation. Most patients are successfully treated with drainage tubes. The unstable patient may necessitate thoracotomy at the emergency room to drain cardiac tamponade, provide cardiac massage and control bleeding. The guidelines for this procedure are reviewed. Need for further work-up of potential injuries to other mediastinal organs is frequently screened by computerized tomography. Surgery might still be needed, on a less emergent basis, in order to repair injuries to the trachea/esophagus, retained hemothorax, or to rule out diaphragmatic injury. Laparoscopic and thoracoscopic procedures may be used in specific situations.

  8. Penetrating Fire Extinguisher

    NASA Technical Reports Server (NTRS)

    1985-01-01

    When Feecon Corporation, a manufacturer of fire protection systems, needed a piercing nozzle for larger aircraft, they were assisted by Kennedy Space Center who provided the company with a fire extinguisher with a hard pointed tip that had been developed in case of an orbiter crash landing. The nozzle can penetrate metal skins of aircraft, trains, etc. Feecon obtained a license and now markets its cobra ram piercing nozzle to airport firefighters. Its primary advantage is that the nozzle can be held in one spot during repeated blows of the ram. *This product has been discontinued and is no longer commercially available.

  9. Deep penetration of light into biotissue

    NASA Astrophysics Data System (ADS)

    Bearden, Edward D.; Wilson, James D.; Zharov, Vladimir P.; Lowery, Curtis L.

    2001-07-01

    The results of a study of deep (several centimeters) light penetration into biological tissue are presented in order to estimate its significance to potentially photosensitive structures and processes including the fetal eyes. In order to accomplish this goal, samples of various tissues (fat, muscle, and uterus) from surgical patients and autopsies were examined with a double integrating sphere arrangement to determine their optical properties. The results were implemented in a Monte Carlo modeling program. Next, optical fiber probes were inserted into the uterus and abdominal wall of patients undergoing laparoscopic procedures. The fibers were couples to a photomultiplier tube with intervening filters allowing measurements of light penetration at various wavelengths. To determine the feasibility of stimulation in utero, a xenon lamp and waveguide were used to transilluminate the abdomen of several labor patients. Light in the range of 630 to 670 nm where the eye sensitivity and penetration depth are well matched, will likely provide the best chance of visual stimulation. Fetal heart rate, fetal movement, and fetal magnetoencephalography (SQUID) and electroencephalography (EEG) were observed in different studies to determine if stimulation has occurred. Since internal organs and the fetus are completely dark adapted, the amount of light required to simulate in our opinion could be on the order of 10(superscript -8 Watts.

  10. Penetrating Trauma to the Ureter, Bladder, and Urethra

    PubMed Central

    Zaid, Uwais B.; Bayne, David B.; Harris, Catherine R.; Alwaal, Amjad; McAninch, Jack W.; Breyer, Benjamin N.

    2015-01-01

    We describe the epidemiology, diagnosis, and management of adult civilian penetrating trauma to the ureter, bladder, and urethra. Trauma is a significant source of death and morbidity. Genitourinary injuries are present in 10% of penetrating trauma cases. Prompt recognition and appropriate management of genitourinary injuries, which are often masked or overlooked due to concomitant injuries, is essential to minimize morbidity. Penetrating trauma most commonly results from gunshot wounds or stab wounds. Compared to blunt trauma, these typically require surgical exploration. An understanding of anatomy and a high index of suspicion are necessary for prompt recognition of genitourinary injuries. PMID:26623247

  11. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  12. Overview - Hard Rock Penetration

    SciTech Connect

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  13. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  14. Monolithic ballasted penetrator

    DOEpatents

    Hickerson, Jr., James P.; Zanner, Frank J.; Baldwin, Michael D.; Maguire, Michael C.

    2001-01-01

    The present invention is a monolithic ballasted penetrator capable of delivering a working payload to a hardened target, such as reinforced concrete. The invention includes a ballast made from a dense heavy material insert and a monolithic case extending along an axis and consisting of a high-strength steel alloy. The case includes a nose end containing a hollow portion in which the ballast is nearly completely surrounded so that no movement of the ballast relative to the case is possible during impact with a hard target. The case is cast around the ballast, joining the two parts together. The ballast may contain concentric grooves or protrusions that improve joint strength between the case and ballast. The case further includes a second hollow portion; between the ballast and base, which has a payload fastened within this portion. The penetrator can be used to carry instrumentation to measure the geologic character of the earth, or properties of arctic ice, as they pass through it.

  15. Sand Penetration Experiments

    NASA Astrophysics Data System (ADS)

    Bless, Stephan; Berry, Don; Lawhorn, William

    2009-06-01

    In an experimental program, steel bullets and short cylinders, and tungsten alloy rods were shot into dry silica sand at 600 to 1100 m/s. The rods included finsets that were designed for aerodynamic stabilization. The fins also apparently provided trajectory stabilization within the sand as well. Time-of-arrival screens allowed measurement of velocity. Analysis of those data indicated that drag coefficients increased as projectiles slowed down. Comparison with previous data indicates there was a slight increase in drag coefficient of rods over expected values for unfinned rods; however, the net result was penetration normalized by length was as high as 40, depending on nose shape. It was found that when the velocity exceeded about 80 m/s (which is close to the speed of sound in sand) sand particles were broken down into their constituent grains, resulting in a decrease in size by about 1000. Normalized penetration is expected to scale as kinetic energy per unit area, and it was significantly higher for the rods than for the other projectiles. This is attributed to stabilization from interaction of the fins with the cavity wall.

  16. Penetration in GTA welding

    SciTech Connect

    Heiple, C.R.; Burgardt, P.

    1990-01-01

    The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

  17. Post-penetrating keratoplasty glaucoma

    PubMed Central

    Aggarwal, Anand; Minudath, KB; Vanathi, M; Choudhary, Sunil; Gupta, Viney; Sihota, Ramanjit; Panda, Anita

    2008-01-01

    Post-penetrating keratoplasty (post-PK) glaucoma is an important cause of irreversible visual loss and graft failure. The etiology for this disorder is multifactorial, and with the use of new diagnostic equipment, it is now possible to elucidate the exact pathophysiology of this condition. A clear understanding of the various mechanisms that operate during different time frames following PK is essential to chalk out the appropriate management algorithms. The various issues with regard to its management, including the putative risk factors, intraocular pressure (IOP) assessment post-PK, difficulties in monitoring with regard to the visual fields and optic nerve evaluation, are discussed. A step-wise approach to management starting from the medical management to surgery with and without metabolites and the various cycloablative procedures in cases of failed filtering procedures and excessive perilimbal scarring is presented. Finally, the important issue of minimizing the incidence of glaucoma following PK, especially through the use of oversized grafts and iris tightening procedures in the form of concomitant iridoplasty are emphasized. It is important to weigh the risk-benefit ratio of any modality used in the treatment of this condition as procedures aimed at IOP reduction, namely trabeculectomy with antimetabolites, and glaucoma drainage devices can trigger graft rejection, whereas cyclodestructive procedures can not only cause graft failure but also precipitate phthisis bulbi. Watchful expectancy and optimal time of intervention can salvage both graft and vision in this challenging condition. PMID:18579984

  18. Water penetration study

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.

    1973-01-01

    Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.

  19. Characterization of Light Lesion Paradigms and Optical Coherence Tomography as Tools to Study Adult Retina Regeneration in Zebrafish

    PubMed Central

    Weber, Anke; Hochmann, Sarah; Cimalla, Peter; Gärtner, Maria; Kuscha, Veronika; Hans, Stefan; Geffarth, Michaela; Kaslin, Jan; Koch, Edmund; Brand, Michael

    2013-01-01

    Light-induced lesions are a powerful tool to study the amazing ability of photoreceptors to regenerate in the adult zebrafish retina. However, the specificity of the lesion towards photoreceptors or regional differences within the retina are still incompletely understood. We therefore characterized the process of degeneration and regeneration in an established paradigm, using intense white light from a fluorescence lamp on swimming fish (diffuse light lesion). We also designed a new light lesion paradigm where light is focused through a microscope onto the retina of an immobilized fish (focused light lesion). Focused light lesion has the advantage of creating a locally restricted area of damage, with the additional benefit of an untreated control eye in the same animal. In both paradigms, cell death is observed as an immediate early response, and proliferation is initiated around 2 days post lesion (dpl), peaking at 3 dpl. We furthermore find that two photoreceptor subtypes (UV and blue sensitive cones) are more susceptible towards intense white light than red/green double cones and rods. We also observed specific differences within light lesioned areas with respect to the process of photoreceptor degeneration: UV cone debris is removed later than any other type of photoreceptor in light lesions. Unspecific damage to retinal neurons occurs at the center of a focused light lesion territory, but not in the diffuse light lesion areas. We simulated the fish eye optical properties using software simulation, and show that the optical properties may explain the light lesion patterns that we observe. Furthermore, as a new tool to study retinal degeneration and regeneration in individual fish in vivo, we use spectral domain optical coherence tomography. Collectively, the light lesion and imaging assays described here represent powerful tools for studying degeneration and regeneration processes in the adult zebrafish retina. PMID:24303018

  20. Adenosine 5' triphosphate evoked mobilization of intracellular calcium in central nervous system white matter of adult mouse optic nerve.

    PubMed

    James, G; Butt, A M

    1999-06-11

    Although it has been established that immature glial cells express functional purinergic receptors, the responsiveness of mature glial cells in vivo had not been elucidated. This question was addressed using fura-2 ratiometric measurements of [Ca2+]i in the adult mouse optic nerve, a central nervous system (CNS) white matter tract, taking advantage of the facts that (i), the optic nerve contains glial cells but not neurons and (ii), that fura-2 loads primarily astrocytes in isolated intact optic nerves. We show that adenosine 5' triphosphate (ATP) evoked an increase in [Ca2+]i in a concentration-dependent manner with a half-maximal effect at 3 microm ATP, and with a rank order of agonist potency of ATP > ADP > alpha,beta-methyline-ATP > UDP > adenosine. The results indicate mainly P2Y and P2X components, consistent with the in vitro astroglial purinergic receptor profile. The in vivo response of mature glia to ATP may be important in their response to CNS damage.

  1. Monitoring of Single-Cell Responses in the Optic Tectum of Adult Zebrafish with Dextran-Coupled Calcium Dyes Delivered via Local Electroporation

    PubMed Central

    Kassing, Vanessa

    2013-01-01

    The zebrafish (Danio rerio) has become one of the major animal models for in vivo examination of sensory and neuronal computation. Similar to Xenopus tadpoles neural activity in the optic tectum, the major region controlling visually guided behavior, can be examined in zebrafish larvae by optical imaging. Prerequisites of these approaches are usually the transparency of larvae up to a certain age and the use of two-photon microscopy. This principle of fluorescence excitation was necessary to suppress crosstalk between signals from individual neurons, which is a critical issue when using membrane-permeant dyes. This makes the equipment to study neuronal processing costly and limits the approach to the study of larvae. Thus there is lack of knowledge about the properties of neurons in the optic tectum of adult animals. We established a procedure to circumvent these problems, enabling in vivo calcium imaging in the optic tectum of adult zebrafish. Following local application of dextran-coupled dyes single-neuron activity of adult zebrafish can be monitored with conventional widefield microscopy, because dye labeling remains restricted to tens of neurons or less. Among the neurons characterized with our technique we found neurons that were selective for a certain pattern orientation as well as neurons that responded in a direction-selective way to visual motion. These findings are consistent with previous studies and indicate that the functional integrity of neuronal circuits in the optic tectum of adult zebrafish is preserved with our staining technique. Overall, our protocol for in vivo calcium imaging provides a useful approach to monitor visual responses of individual neurons in the optic tectum of adult zebrafish even when only widefield microscopy is available. This approach will help to obtain valuable insight into the principles of visual computation in adult vertebrates and thus complement previous work on developing visual circuits. PMID:23667529

  2. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, Phillip W.; Stampfer, Joseph F.; Bradley, Orvil D.

    1999-01-01

    A universal penetration test apparatus for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material.

  3. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, P.W.; Stampfer, J.F.; Bradley, O.D.

    1999-02-02

    A universal penetration test apparatus is described for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material. 23 figs.

  4. Optic nerve atrophy

    MedlinePlus

    Optic atrophy; Optic neuropathy ... There are many causes of optic atrophy. The most common is poor blood flow. This is called ischemic optic neuropathy. The problem most often affects older adults. ...

  5. Long-Term Optical Device Use by Young Adults with Low Vision

    ERIC Educational Resources Information Center

    Bachofer, Cynthia Susan

    2013-01-01

    The purpose of this study was to investigate the long-term use of optical devices by individuals who participated in a school-based comprehensive low vision program focusing on use of devices, both near and distance. Thirty-seven participants (five non-users), ages 18-28, completed phone interviews giving information on their personal…

  6. Systematic evaluation of a time-domain Monte Carlo fitting routine to estimate the adult brain optical properties

    NASA Astrophysics Data System (ADS)

    Selb, Juliette; Ogden, Tyler M.; Dubb, Jay; Fang, Qianqian; Boas, David A.

    2013-03-01

    Time-domain near-infrared spectroscopy (TD-NIRS) offers the ability to measure the absolute baseline optical properties of a tissue. Specifically, for brain imaging, the robust assessment of cerebral blood volume and oxygenation based on measurement of cerebral hemoglobin concentrations is essential for reliable cross-sectional and longitudinal studies. In adult heads, these baseline measurements are complicated by the presence of thick extra-cerebral tissue (scalp, skull, CSF). A simple semi-infinite homogeneous model of the head has proven to have limited use because of the large errors it introduces in the recovered brain absorption. Analytical solutions for layered media have shown improved performance on Monte-Carlo simulated data and layered phantom experiments, but their validity on real adult head data has never been demonstrated. With the advance of fast Monte Carlo approaches based on GPU computation, numerical methods to solve the radiative transfer equation become viable alternatives to analytical solutions of the diffusion equation. Monte Carlo approaches provide the additional advantage to be adaptable to any geometry, in particular more realistic head models. The goals of the present study were twofold: (1) to implement a fast and flexible Monte Carlo-based fitting routine to retrieve the brain optical properties; (2) to characterize the performances of this fitting method on realistic adult head data. We generated time-resolved data at various locations over the head, and fitted them with different models of light propagation: the homogeneous analytical model, and Monte Carlo simulations for three head models: a two-layer slab, the true subject's anatomy, and that of a generic atlas head. We found that the homogeneous model introduced a median 20 to 25% error on the recovered brain absorption, with large variations over the range of true optical properties. The two-layer slab model only improved moderately the results over the homogeneous one. On

  7. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  8. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  9. Top Sounder Ice Penetration

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Goemmer, S. A.; Sweeney, J. H.

    2014-12-01

    Ice draft measurements are made as part of normal operations for all US Navy submarines operating in the Arctic Ocean. The submarine ice draft data are unique in providing high resolution measurements over long transects of the ice covered ocean. The data has been used to document a multidecadal drop in ice thickness, and for validating and improving numerical sea-ice models. A submarine upward-looking sonar draft measurement is made by a sonar transducer mounted in the sail or deck of the submarine. An acoustic beam is transmitted upward through the water column, reflecting off the bottom of the sea ice and returning to the transducer. Ice thickness is estimated as the difference between the ship's depth (measured by pressure) and the acoustic range to the bottom of the ice estimated from the travel time of the sonar pulse. Digital recording systems can provide the return off the water-ice interface as well as returns that have penetrated the ice. Typically, only the first return from the ice hull is analyzed. Information regarding ice flow interstitial layers provides ice age information and may possibly be derived with the entire return signal. The approach being investigated is similar to that used in measuring bottom sediment layers and will involve measuring the echo level from the first interface, solving the reflection loss from that transmission, and employing reflection loss versus impedance mismatch to ascertain ice structure information.

  10. Electromagnetic Field Penetration Studies

    NASA Technical Reports Server (NTRS)

    Deshpande, M.D.

    2000-01-01

    A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

  11. Transorbital orbitocranial penetrating injury caused by a metal bar

    PubMed Central

    Arslan, Mehmet; Eseoğlu, Metehan; Güdü, Burhan Oral; Demir, Ismail

    2012-01-01

    Transorbital intracranial injury is uncommon, representing 0.04% of penetrating head trauma with a high mortality rate. Orbital penetrating injuries may cause severe brain injury if the cranium is entered, typically via the orbital roof, the superior orbital fissure, or the optic canal. A 13-year-old male sustained a severe brain injury due to penetration of the right orbit with an iron bar. The bar entered the inferiomedial aspect of the orbit and emerged from the left occipital bone. Neurological examination revealed deep coma (GCS: E1M2V1) with fixed, dilated, and non-reactive pupils. The bar followed an intracranial trajectory, through the third ventricle and suprasellar cistern. The patient underwent an immediate exploration with removal of the bar. Unfortunately, he died 10 days postoperatively due to severe diencephalic injury with brainstem herniation. In this case report, we discuss the radiologic diagnosis and surgical management of transorbital orbitocranial injury by foreign body penetration. PMID:22865972

  12. Static penetration resistance of soils

    NASA Technical Reports Server (NTRS)

    Durgunoglu, H. T.; Mitchell, J. K.

    1973-01-01

    Model test results were used to define the failure mechanism associated with the static penetration resistance of cohesionless and low-cohesion soils. Knowledge of this mechanism has permitted the development of a new analytical method for calculating the ultimate penetration resistance which explicitly accounts for penetrometer base apex angle and roughness, soil friction angle, and the ratio of penetration depth to base width. Curves relating the bearing capacity factors to the soil friction angle are presented for failure in general shear. Strength parameters and penetrometer interaction properties of a fine sand were determined and used as the basis for prediction of the penetration resistance encountered by wedge, cone, and flat-ended penetrometers of different surface roughness using the proposed analytical method. Because of the close agreement between predicted values and values measured in laboratory tests, it appears possible to deduce in-situ soil strength parameters and their variation with depth from the results of static penetration tests.

  13. An Earth Penetrating Modeling Assessment

    SciTech Connect

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  14. Studying skin penetration by NMR imaging

    NASA Astrophysics Data System (ADS)

    Burg, J. M.; Voelker, M.; Schlupp, P.; Schmidts, T.; Maeder, U.; Bergmann, T.; Runkel, F.; Heverhagen, J. T.; Fiebich, M.

    2011-03-01

    Skin penetration studies are an important part for the development of dermal drug carrier systems. As a novel approach a 7-tesla Magnetic Resonance Imaging (MRI) Scanner was used to obtain information about the penetration of agents into the skin. The main advantage of this method is, that the properties of the skin does not influence the signals. Compared to optical assessments the MRI method is not limited to imaging depth. Furthermore, it is possible to analyze fat and water components of the skin separately. The aim of this work was to evaluate, if this method is a promising analysis tool for the visualization of the transport of substances across the skin. Gadobutrol (Gadovist®1.0), respresenting a coventional contrast agent in MRI, was used as a model drug for the visualization of the skin penetration. These first promising results showed that Gadobutrol, incorporated in an oil-in-water emulsion, could be detected across the skin tissue compared to an aqueous solution. After 24 hours, the pixel intensity value was increased about 4-fold compared to an untreated tissue.

  15. Neuropsychiatric changes following penetrating head injury in children

    PubMed Central

    Badhiwala, Jetan H.; Blackham, Janet R.; Bhardwaj, Ratan D.

    2014-01-01

    Background: Penetrating head injuries demand the prompt attention of a neurosurgeon. While most neurosurgical centers are experienced in the acute management of these injuries, less is known about the long-term neuropsychiatric sequelae of penetrating head trauma. In adults, direct injury to the frontal lobe classically has been associated with mental status changes. However, there is less published data in children. Case Description: We report the case of a 12-year-old boy who suffered a penetrating head injury to the frontal lobes secondary to a self-inflicted gunshot wound, and experienced subsequent resolution of pre-existing bipolar disorder and new onset of attention deficit hyperactivity disorder. Conclusion: Children with penetrating head injury require close multidisciplinary follow-up in order to monitor, and accordingly implement management strategies, for associated sequelae, including behavioral and neuropsychiatric changes. PMID:25422782

  16. Optical coherence tomography reveals in vivo cortical structures of adult rats in response to cerebral ischemia injury

    NASA Astrophysics Data System (ADS)

    Ni, Yi-rong; Guo, Zhou-yi; Shu, So-yun; Bao, Xin-min

    2008-12-01

    Optical coherence tomography(OCT) is a high resolution imaging technique which uses light to directly image living tissue. we investigate the potential use of OCT for structural imaging of the ischemia injury mammalian cerebral cortex. And we examine models of middle cerebral artery occlusion (MCAO) in rats in vivo using OCT. In particular, we show that OCT can perform in vivo detection of cortex and differentiate normal and abnormal cortical anatomy. This OCT system in this study provided an axial resolution of 10~15μ m, the transverse resolution of the system is about 25 μm. OCT can provide cross-sectional images of cortical of adult rats in response to cerebral ischemia injury.We conclude that OCT represents an exciting new approach to visualize, in real-time, pathological changes in the cerebral cortex structures and may offer a new tool for Possible neuroscience clinical applications.

  17. Laterality of Stance during Optic Flow Stimulation in Male and Female Young Adults

    PubMed Central

    Persiani, Michela; Piras, Alessandro; Squatrito, Salvatore; Raffi, Milena

    2015-01-01

    During self-motion, the spatial and temporal properties of the optic flow input directly influence the body sway. Men and women have anatomical and biomechanical differences that influence the postural control during visual stimulation. Given that recent findings suggest a peculiar role of each leg in the postural control of the two genders, we investigated whether the body sway during optic flow perturbances is lateralized and whether anteroposterior and mediolateral components of specific center of pressure (COP) parameters of the right and left legs differ, reexamining a previous experiment (Raffi et al. (2014)) performed with two, side-by-side, force plates. Experiments were performed on 24 right-handed and right-footed young subjects. We analyzed five measures related to the COP of each foot and global data: anteroposterior and mediolateral range of oscillation, anteroposterior and mediolateral COP velocity, and sway area. Results showed that men consistently had larger COP parameters than women. The values of the COP parameters were correlated between the two feet only in the mediolateral axis of women. These findings suggest that optic flow stimulation causes asymmetry in postural balance and different lateralization of postural controls in men and women. PMID:26539509

  18. Penetration effect in gyrotropic slab: theory and applications.

    PubMed

    Vytovtov, Konstantin; Mospan, Lyudmila

    2012-06-01

    Scattering properties of a homogeneous anisotropic slab are investigated at fixed crystal anisotropy axis orientation. The penetration phenomenon for an incident wave propagating tangentially to the crystal surface is discussed. Slab-based nonreciprocal optical devices are proposed. Their operating principles are based on the slab scattering properties, but not on the Faraday effect. Numerical data for an optical isolator and frequency detector are presented.

  19. Tyrosine-mutated AAV2-mediated shRNA silencing of PTEN promotes axon regeneration of adult optic nerve

    PubMed Central

    Huang, ZhengRu; Hu, ZiZhong; Xie, Ping; Liu, QingHuai

    2017-01-01

    Activating PI3K/AKT/mTOR signaling pathway via deleting phosphatase and tensin homolog (PTEN) has been confirmed to enhance intrinsic growth capacity of neurons to facilitate the axons regeneration of central nervous system after injury. Considering conditional gene deletion is currently not available in clinical practice, we exploited capsid residue tyrosine 444 to phenylalanine mutated single-stranded adeno-associated virus serotype 2 (AAV2) as a vector delivering short hairpin RNA to silence PTEN to promote retinal ganglion cells (RGCs) survival and axons regeneration in adult rat optic nerve axotomy paradigm. We found that mutant AAV2 displayed higher infection efficiency to RGCs and Müller cells by intravitreal injection, mediated PTEN suppression, resulted in much more RGCs survival and more robust axons regeneration compared with wild type AAV2, due to the different extent of the mTOR complex-1 activation and glutamate aspartate transporter (GLAST) regulation. These results suggest that high efficiency AAV2-mediated PTEN knockdown represents a practicable therapeutic strategy for optic neuropathy. PMID:28323869

  20. Projectile penetration into ballistic gelatin.

    PubMed

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (<120m/s). The results of sphere penetration depth versus projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. © 2013 Published by Elsevier Ltd.

  1. Evaluation of Microencapsulated Penetrant Inspection.

    DTIC Science & Technology

    1980-12-01

    AD-A9b 826 GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE GROUP F/6 IA/2ADG EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION.(U) DEC 80 J M...4156 ADA096826 EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION i :I J.M. Portaz Aircraft Engine Group General Electric Company Cincinnati, Ohio... Microencapsulated Penetrant 5 7riJF-Iehica17 = Inspection p un May@84 -1 ---- --- ---- 19AMFGK657j7 7. AiJTHOR(s) nVCWRACT OR GRANT m 𔃻 " JO J.M./Portaz

  2. Enriched Environment Protects the Optic Nerve from Early Diabetes-Induced Damage in Adult Rats

    PubMed Central

    Dorfman, Damián; Aranda, Marcos L.; Rosenstein, Ruth E.

    2015-01-01

    Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Axoglial alterations of the distal (close to the chiasm) optic nerve (ON) could be the first structural change of the visual pathway in streptozotocin (STZ)-induced diabetes in rats. We analyzed the effect of environmental enrichment on axoglial alterations of the ON provoked by experimental diabetes. For this purpose, three days after vehicle or STZ injection, animals were housed in enriched environment (EE) or remained in a standard environment (SE) for 6 weeks. Anterograde transport, retinal morphology, optic nerve axons (toluidine blue staining and phosphorylated neurofilament heavy immunoreactivity), microglia/macrophages (ionized calcium binding adaptor molecule 1 (Iba-1) immunoreactivity), astrocyte reactivity (glial fibrillary acid protein-immunostaining), myelin (myelin basic protein immunoreactivity), ultrastructure, and brain derived neurotrophic factor (BDNF) levels were assessed in non-diabetic and diabetic animals housed in SE or EE. No differences in retinal morphology or retinal ganglion cell number were observed among groups. EE housing which did not affect the STZ-induced weight loss and hyperglycemia, prevented a decrease in the anterograde transport from the retina to the superior colliculus, ON axon number, and phosphorylated neurofilament heavy immunoreactivity. Moreover, EE housing prevented an increase in Iba-1 immunoreactivity, and astrocyte reactivity, as well as ultrastructural myelin alterations in the ON distal portion at early stages of diabetes. In addition, EE housing avoided a decrease in BDNF levels induced by experimental diabetes. These results suggest that EE induced neuroprotection in the diabetic visual pathway. PMID:26312758

  3. THE KINETICS OF PENETRATION

    PubMed Central

    Osterhout, W. J. V.; Kamerling, S. E.

    1934-01-01

    A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external

  4. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  5. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  6. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  7. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

  8. Penetration through the Skin Barrier.

    PubMed

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates. During recent decades, the latter has received increased attention as a route for intentionally delivering drugs to patients. This has stimulated research in methods for sampling, measuring and predicting percutaneous penetration. Previous chapters have described how different endogenous, genetic and exogenous factors may affect barrier characteristics. The present chapter introduces the theory for barrier penetration (Fick's law), and describes and discusses different methods for measuring the kinetics of percutaneous penetration of chemicals, including in vitro methods (static and flow-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous penetration. Finally, a short discussion of the advantages and challenges of each method is provided, which will hopefully allow the reader to improve decision making and treatment planning, as well as the evaluation of experimental studies of percutaneous penetration of chemicals. © 2016 S. Karger AG, Basel.

  9. THE PENETRATION OF STRONG ELECTROLYTES

    PubMed Central

    Cooper, W. C.; Dorcas, M. J.; Osterhout, W. J. V.

    1929-01-01

    The entrance of strong electrolytes into Valonia is very slow unless the cells are injured. This, together with the very high electrical resistance of the protoplasm, suggests that they may penetrate largely as undissociated molecules formed at the surface of the protoplasm by the collision of ions. Under favorable circumstances KCl may be absorbed to the extent of 3 x 10–8 mols per hour per sq. cm. of surface together with about 0.17 as much NaCl. Other substances which seem to penetrate to some extent are Li, Rb, Br, BrO3, I, IO3, and selenite. Little or no penetration is shown by SCN, ferricyanide, ferrocyanide, formate, salicylate, tungstate, seleniate, NO2, SO3, Sb, glycerophosphate, and many heavy metals and the alkaline earths. In sea water whose specific gravity had been increased by CsCl cells of Valonia floated for over a year and there was little or no penetration of Cs except as the result of injury. The penetration of NH4Cl decreases the specific gravity of the sap and causes the cells to float: under these circumstances they live indefinitely. It is probable that NH3 or NH4OH penetrates and is subsequently changed to NH4Cl. It would seem that if the sea contained a little more ammonia this would be a floating organism. PMID:19872471

  10. Is Color Experience Cognitively Penetrable?

    PubMed

    Brogaard, Berit; Gatzia, Dimitria E

    2017-01-01

    Is color experience cognitively penetrable? Some philosophers have recently argued that it is. In this paper, we take issue with the claim that color experience is cognitively penetrable. We argue that the notion of cognitive penetration that has recently dominated the literature is flawed since it fails to distinguish between the modulation of perceptual content by non-perceptual principles and genuine cognitive penetration. We use this distinction to show that studies suggesting that color experience can be modulated by factors of the cognitive system do not establish that color experience is cognitively penetrable. Additionally, we argue that even if color experience turns out to be modulated by color-related beliefs and knowledge beyond non-perceptual principles, it does not follow that color experience is cognitively penetrable since the experiences of determinate hues involve post-perceptual processes. We conclude with a brief discussion of the implications that these ideas may have on debates in philosophy. Copyright © 2016 Cognitive Science Society, Inc.

  11. Optic Nerve Tilt, Crescent, Ovality, and Torsion in a Multi-Ethnic Cohort of Young Adults With and Without Myopia

    PubMed Central

    Marsh-Tootle, Wendy L.; Harb, Elise; Hou, Wei; Zhang, Qinghua; Anderson, Heather A.; Weise, Katherine; Norton, Thomas T.; Gwiazda, Jane; Hyman, Leslie

    2017-01-01

    Purpose The purpose of this article is to evaluate optic nerve head (ONH) characteristics in an ethnically diverse cohort of young U.S. adults. Methods In this study, 409 myopes and 206 nonmyopes (median age 22 years) completed measures including biometry and spectral domain optical coherence tomography from enface (ovality and torsion) and cross-sectional (tilt and crescent width) scans. Associated factors were evaluated using multivariable models. Results In myopic versus nonmyopic right eyes, median tilt (6.0° vs. 2.4°; P < 0.0001) and frequency of crescents (49% vs. 10%; P < 0.0001) were higher in myopes. Right eyes with crescents had higher median tilts (8.8° [myopic], 9.0° [nonmyopic]) than those without crescent (2.5° [myopic], 2.1° [nonmyopic]), irrespective of refractive group (both P < 0.0001). Torsion was similar between groups, with a slight difference in ovality (0.89 vs. 0.91; P < 0.03). Data in the left eyes were similar, and modeling was done only for the right myopic eyes. Multivariable models showed that an increased tilt was associated with ethnicity (P < 0.001), the presence of crescent (P < 0.001), and smaller ONH diameter (P < 0.0031), with interactions between ethnicity and crescent (P = 0.002). Specifically, ONH tilt was significantly higher in Asian eyes without crescent (P < 0.0001 for all comparisons), and crescent width was associated with increased tilt in non-Asian eyes (P < 0.02). Crescent width was associated with ethnicity (greatest in Asians) and disc tilt. Interactions were observed between tilt and ethnicity, whereby tilt had a greater effect on crescent width in non-Asian eyes, and crescent width was associated with increased tilt in non-Asian eyes. Conclusions The data clarify the influence of ethnicity and myopia on ONH characteristics in young adults and may inform future studies of biomechanical properties or of retinal pathology of the myopic eye. PMID:28654981

  12. Normal macular thickness measurements using optical coherence tomography in healthy eyes of adult Chinese persons: the Handan Eye Study.

    PubMed

    Duan, Xin Rong; Liang, Yuan Bo; Friedman, David S; Sun, Lan Ping; Wong, Tien Yin; Tao, Qiu Shan; Bao, Lingzhi; Wang, Ning Li; Wang, Jie Jin

    2010-08-01

    To describe macular thickness measured by optical coherence tomography (OCT) in healthy eyes of adult Chinese persons. Population-based cross-sectional study. Chinese adults aged 30+ years who were residents of Handan, North China. The Handan Eye Study is a population-based study of eye disease in Chinese persons. Eligible residents underwent a comprehensive ophthalmic examination including OCT (Stratus OCT, Carl Zeiss Meditec Inc., Jena, Germany). Fast macular thickness scans were performed over maculae within 6 mm in diameter, divided into 3 regions (central, inner, and outer, with a diameter of 1, 3, and 6 mm, respectively) and 9 quadrants (1 in the central region and 4 each in the inner and outer regions). Retinal thickness (means and standard deviations) was calculated by OCT mapping software, presented for foveal minimum, central macula (within 1 mm diameter), and inner and outer regions divided by 8 quadrants. Macular thickness measured by OCT. Of the 6830 participants (90.4% response rate) examined, 2230 eyes of healthy subjects with high-quality OCT scans were selected (32.7% of participants; mean age, 46.4+/-9.9 years, 58.4% were women). The mean foveal minimum, central, inner, and outer macular thicknesses were 150.3 (18.1) microm, 176.4 (17.5) microm, 255.3 (14.9) microm, and 237.7 (12.4) microm, respectively (overall differences, P<0.001). The mean foveal volume was 0.139 (0.014) mm(3), and the mean total macular volume was 6.761 (0.516) mm(3). In the inner region, the nasal quadrant was thinner than the superior and inferior quadrants, and in the outer region, the nasal quadrant was the thickest (P<0.001). Age was positively correlated with foveal (beta coefficient = 3.582) and central macular (beta coefficient = 2.422) thicknesses. The foveal minimum, central, inner, and outer macular thicknesses were significantly greater in men than in women. Fasting plasma glucose was negatively correlated with central macular thickness (2.416 mm reduction per

  13. Double-Plate Penetration Equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    2000-01-01

    This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

  14. Development and testing of a Europa Penetrator for Astrobiology

    NASA Astrophysics Data System (ADS)

    Vijendran, S.; Perkinson, M.-C.; Waugh, L.; Ratcliffe, A.; Kennedy, T.; Church, P.; Fielding, J.; Taylor, N.

    2014-04-01

    Two phases of Penetrator development activities have been funded by ESA. The first phase focussed on the mission and system definition of a penetrator and delivery system for a mission to Europa and the second phase provided an update of the penetrator design for a larger suite of instruments focused on astrobiology and the demonstration of key system technologies through a programme of small scale and full scale testing. The science focus for the Europa penetrator is Astrobiology while the key science goals can be achieved within the first day of operation but a longer lifetime is required for the transmission of the science data to the orbiter. The extreme temperature environment of the Europan surface drove the design to a solution of a Penetrator with two separate bays. The front bay will be a short lifetime bay which will sample the surface and complete all analysis and data transfer within 10 hours. The rear bay is a warm bay which will house EPSC Abstracts Vol. 9, EPSC2014-642, 2014 European Planetary Science Congress 2014 c Author(s) 2014 EPSC European Planetary Science Congress the penetrator support systems required to transmit all collected data to the orbiter. The scientific instruments housed by the penetrator includeds a optical microimager, a habitability package and a mass spectrometer. A drilling and sampling mechanism is used for accessing the icy material outside the Penetrator for analysis. Small scale trails have been undertaken at the University of Cambridge Cavendish Laboratory to validate the impact modelling techniques and the robustness of critical components. A range of trials have been carried out to assess survivability of key elements of the design, including the sampling mechanism, potting compounds, accelerometers, shell, batteries and Torlon suspension springs. Full scale trials have been carried out to test the overall structural integrity of the system and the penetration profile. This programme was carried out in June 2013 at the

  15. Quantitative characterization of mechanically indented in vivo human skin in adults and infants using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Huang, Pin-Chieh; Pande, Paritosh; Shelton, Ryan L.; Joa, Frank; Moore, Dave; Gillman, Elisa; Kidd, Kimberly; Nolan, Ryan M.; Odio, Mauricio; Carr, Andrew; Boppart, Stephen A.

    2017-03-01

    Influenced by both the intrinsic viscoelasticity of the tissue constituents and the time-evolved redistribution of fluid within the tissue, the biomechanical response of skin can reflect not only localized pathology but also systemic physiology of an individual. While clinical diagnosis of skin pathologies typically relies on visual inspection and manual palpation, a more objective and quantitative approach for tissue characterization is highly desirable. Optical coherence tomography (OCT) is an interferometry-based imaging modality that enables in vivo assessment of cross-sectional tissue morphology with micron-scale resolution, which surpasses those of most standard clinical imaging tools, such as ultrasound imaging and magnetic resonance imaging. This pilot study investigates the feasibility of characterizing the biomechanical response of in vivo human skin using OCT. OCT-based quantitative metrics were developed and demonstrated on the human subject data, where a significant difference between deformed and nondeformed skin was revealed. Additionally, the quantified postindentation recovery results revealed differences between aged (adult) and young (infant) skin. These suggest that OCT has the potential to quantitatively assess the mechanically perturbed skin as well as distinguish different physiological conditions of the skin, such as changes with age or disease.

  16. Lunar regolith penetrators and cutters

    NASA Technical Reports Server (NTRS)

    Barnes, Frank; Sture, Stein

    1991-01-01

    An apparatus was designed and built for conducting simulation experiments on cutting tool penetration in the centrifuge. This equipment is mounted on the laminar container which is used for the regolith densification study, so that the end product of the latter, i.e., a regolith bed with the proper density profile, can be used directly for the penetration tests. In this apparatus, an etching tool is suspended through a pulley system by the action of a double acting air cylinder. By adjusting the air pressure acting on each side of the cylinder, the net downward force acting on the tool can be controlled. The penetration of the tool is measured by an LVDT. This apparatus was proof-tested in the centrifuge and is ready for use in conjunction with the regolith densification experiments.

  17. [Penetrating transorbital intracranial foreign body].

    PubMed

    Civelek, Erdinç; Bilgiç, Salih; Kabataş, Serdar; Hepgül, Kemal Tanju

    2006-07-01

    We report a seven year-old boy who suffered left orbital penetration of an industrial sewing machine needle. The needle passing through the left orbit and sphenoid bone at the posterior was extending into the layers of the dura of the left temporal lobe. In this patient, we preferred surgical approach and there was no complication after surgery. Penetrating intraorbital foreign materials with intracranial extension may lead to complications such as intracerebral hematoma, brain abscess, CSF fistula, proptosis of the eye, diplopia, orbital cellulitis and periorbital abscess. They have to be removed by surgical approach to prevent potential complications.

  18. Fluconazole Penetration into the Pancreas

    PubMed Central

    Shrikhande, Shailesh; Friess, Helmut; Issenegger, Claudia; Martignoni, Marcus E.; Yong, Huang; Gloor, Beat; Yeates, Rodney; Kleeff, Jörg; Büchler, Markus W.

    2000-01-01

    Because of antibiotic prophylaxis for necrotizing pancreatitis, the frequency of fungal superinfection in patients with pancreatic necrosis is increasing. In this study we analyzed the penetration of fluconazole into the human pancreas and in experimental acute pancreatitis. In human pancreatic tissues, the mean fluconazole concentration was 8.19 ± 3.38 μg/g (96% of the corresponding concentration in serum). In experimental edematous and necrotizing pancreatitis, 88 and 91% of the serum fluconazole concentration was found in the pancreas. These data show that fluconazole penetration into the pancreas is sufficient to prevent and/or treat fungal contamination in patients with pancreatic necrosis. PMID:10952621

  19. Mars surface penetrator: System description

    NASA Technical Reports Server (NTRS)

    Manning, L. A. (Editor)

    1977-01-01

    A point design of a penetrator system for a Mars mission is described. A strawman payload which is to conduct measurements of geophysical and meteorological parameters is included in the design. The subsystems used in the point design are delineated in terms of power, mass, volume, data, and functional modes. The prospects for survival of the rigors of emplacement are described. Data handling and communications plans are presented to allow consideration of the requirements placed by the penetrator on the orbiter and ground operations. The point design is technically feasible and the payload selection scientifically desirable.

  20. Penetrating trauma to the facial skeleton by pickaxe - case report.

    PubMed

    Neskoromna-Jędrzejczak, Aneta; Bogusiak, Katarzyna; Przygoński, Aleksander; Timler, Dariusz

    2016-01-01

    Number of deaths related with injuries suffered as a result of experienced traumas is increasing. Penetrating traumas of the facial skeleton occur relatively rarely and much more often concern rather children than adults. Epidemiology relating this kind of trauma differs depending on the region of the world. In Poland, gunshot injuries as well as traumas caused by explosions of firecrackers or fireworks amount only to a slight percentage among all facial skeleton traumas, and the most common reason for penetrating traumas lies in accidents or assault with the use of sharp, narrow and long objects that easily enter bones of the facial skeleton. The present study reported the case of 50-year-old man who suffered from trauma of the facial skeleton, which resulted from foreign body (pickaxe) penetration into the subtemporal area, zygomatic arch and the right orbital cavity. The surgical treatment method and final outcome was presented and discussed.

  1. Optical detection of intravenous infiltration

    NASA Astrophysics Data System (ADS)

    Winchester, Leonard W.; Chou, Nee-Yin

    2006-02-01

    Infiltration of medications during infusion therapy results in complications ranging from erythema and pain to tissue necrosis requiring amputation. Infiltration occurs from improper insertion of the cannula, separation of the cannula from the vein, penetration of the vein by the cannula during movement, and response of the vein to the medication. At present, visual inspection by the clinical staff is the primary means for detecting intravenous (IV) infiltration. An optical sensor was developed to monitor the needle insertion site for signs of IV infiltration. Initial studies on simulated and induced infiltrations on a swine model validated the feasibility of the methodology. The presence of IV infiltration was confirmed by visual inspection of the infusion site and/or absence of blood return in the IV line. Potential sources of error due to illumination changes, motion artifacts, and edema were also investigated. A comparison of the performance of the optical device and blinded expert observers showed that the optical sensor has higher sensitivity and specificity, and shorter detection time than the expert observers. An improved model of the infiltration monitoring device was developed and evaluated in a clinical study on induced infiltrations of healthy adult volunteers. The performance of the device was compared with the observation of a blinded expert observer. The results show that the rates of detection of infiltrations are 98% and 82% for the optical sensor and the observer, respectively. The sensitivity and specificity of the optical sensor are 0.97 and 0.98, respectively.

  2. FAA Fluorescent Penetrant Laboratory Inspections

    SciTech Connect

    WINDES,CONNOR L.; MOORE,DAVID G.

    2000-08-02

    The Federal Aviation Administration Airworthiness Assurance NDI Validation Center currently assesses the capability of various non-destructive inspection (NDI) methods used for analyzing aircraft components. The focus of one such exercise is to evaluate the sensitivity of fluorescent liquid penetrant inspection. A baseline procedure using the water-washable fluorescent penetrant method defines a foundation for comparing the brightness of low cycle fatigue cracks in titanium test panels. The analysis of deviations in the baseline procedure will determine an acceptable range of operation for the steps in the inspection process. The data also gives insight into the depth of each crack and which step(s) of the inspection process most affect penetrant sensitivities. A set of six low cycle fatigue cracks produced in 6.35-mm thick Ti-6Al-4V specimens was used to conduct the experiments to produce sensitivity data. The results will document the consistency of the crack readings and compare previous experiments to find the best parameters for water-washable penetrant.

  3. Penetrating trauma to the extremity.

    PubMed

    Manthey, David E; Nicks, Bret A

    2008-02-01

    Penetrating trauma to the extremities is a complex disease that foremost requires the evaluation for vascular injury. This monograph will address an algorithm to assess for associated vascular injury that includes current evaluation techniques. Approaches to wound management and use of antibiotics in the ED are also addressed.

  4. Localizing Ground-Penetrating Radar

    DTIC Science & Technology

    2014-11-01

    determine the vehicles location when adverse conditions, such as heavy rain or fog , snow-covered roads, or lost GPS signals, hamper the...penetrate rain, fog , dust, and snow. LGPR Methodology For subsurface sensing, GPR is one of the most versatile and prolific sensing modal- ities today

  5. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  6. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  7. Optic nerve sheath diameter measurement: a means of detecting raised ICP in adult traumatic and non-traumatic neurosurgical patients.

    PubMed

    Raffiz, Mohd; Abdullah, Jafri M

    2017-01-01

    Bedside ultrasound measurement of optic nerve sheath diameter (ONSD) is emerging as a non-invasive technique to evaluate and predict raised intracranial pressure (ICP). It has been shown in previous literature that ONSD measurement has good correlation with surrogate findings of raised ICP such as clinical and radiological findings suggestive of raised ICP. The objective of the study is to find a correlation between sonographic measurements of ONSD value with ICP value measured via the gold standard invasive intracranial ICP catheter, and to find the cut-off value of ONSD measurement in predicting raised ICP, along with its sensitivity and specificity value. A prospective observational study was performed using convenience sample of 41 adult neurosurgical patients treated in neurosurgical intensive care unit with invasive intracranial pressure monitoring placed in-situ as part of their clinical care. Portable SonoSite ultrasound machine with 7 MHz linear probe were used to measure optic nerve sheath diameter using the standard technique. Simultaneous ICP readings were obtained directly from the invasive monitoring. Seventy-five measurements were performed on 41 patients. The non-parametric Spearman correlation test revealed a significant correlation at the 0.01 level between the ICP and ONSD value, with correlation coefficient of 0.820. The receiver operating characteristic curve generated an area under the curve with the value of 0.964, and with standard error of 0.22. From the receiver operating characteristic curve, we found that the ONSD value of 5.205 mm is 95.8% sensitive and 80.4% specific in detecting raised ICP. ONSD value of 5.205 is sensitive and specific in detecting raised ICP. Bedside ultrasound measurement of ONSD is readily learned, and is reproducible and reliable in predicting raised ICP. This non-invasive technique can be a useful adjunct to the current invasive intracranial catheter monitoring, and has wide potential clinical applications in

  8. Near infrared laser penetration and absorption in human skin

    NASA Astrophysics Data System (ADS)

    Nasouri, Babak; Murphy, Thomas E.; Berberoglu, Halil

    2014-02-01

    For understanding the mechanisms of low level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. In this paper, we present a three dimensional, multi-layer Monte Carlo simulation tool for studying light penetration and absorption in human skin. The skin is modeled as a three-layer participating medium, namely epidermis, dermis, and subcutaneous, where its geometrical and optical properties are obtained from the literature. Both refraction and reflection are taken into account at the boundaries according to Snell's law and Fresnel relations. A forward Monte Carlo method was implemented and validated for accurately simulating light penetration and absorption in absorbing and anisotropically scattering media. Local profiles of light penetration and volumetric absorption densities were simulated for uniform as well as Gaussian profile beams with different spreads at 155 mW average power over the spectral range from 1000 nm to 1900 nm. The results show the effects of beam profiles and wavelength on the local fluence within each skin layer. Particularly, the results identify different wavelength bands for targeted deposition of power in different skin layers. Finally, we show that light penetration scales well with the transport optical thickness of skin. We expect that this tool along with the results presented will aid researchers resolve issues related to dose and targeted delivery of energy in tissues for LLLT.

  9. Drifting while stepping in place in old adults: Association of self-motion perception with reference frame reliance and ground optic flow sensitivity.

    PubMed

    Agathos, Catherine P; Bernardin, Delphine; Baranton, Konogan; Assaiante, Christine; Isableu, Brice

    2017-04-07

    Optic flow provides visual self-motion information and is shown to modulate gait and provoke postural reactions. We have previously reported an increased reliance on the visual, as opposed to the somatosensory-based egocentric, frame of reference (FoR) for spatial orientation with age. In this study, we evaluated FoR reliance for self-motion perception with respect to the ground surface. We examined how effects of ground optic flow direction on posture may be enhanced by an intermittent podal contact with the ground, and reliance on the visual FoR and aging. Young, middle-aged and old adults stood quietly (QS) or stepped in place (SIP) for 30s under static stimulation, approaching and receding optic flow on the ground and a control condition. We calculated center of pressure (COP) translation and optic flow sensitivity was defined as the ratio of COP translation velocity over absolute optic flow velocity: the visual self-motion quotient (VSQ). COP translation was more influenced by receding flow during QS and by approaching flow during SIP. In addition, old adults drifted forward while SIP without any imposed visual stimulation. Approaching flow limited this natural drift and receding flow enhanced it, as indicated by the VSQ. The VSQ appears to be a motor index of reliance on the visual FoR during SIP and is associated with greater reliance on the visual and reduced reliance on the egocentric FoR. Exploitation of the egocentric FoR for self-motion perception with respect to the ground surface is compromised by age and associated with greater sensitivity to optic flow.

  10. Nonhost Root Penetration by Soybean Cyst Nematode

    PubMed Central

    Riggs, R. D.

    1987-01-01

    A total of 66 plants in 50 species were inoculated with eggs and juveniles of soybean cyst nematode, Heterodera glycines. Roots were stained and observed for penetration and development of the nematode. Twenty-six plants were not penetrated; twenty-three were penetrated, but there was no development of the nematode; eight were penetrated with some nematode development; two were penetrated and had considerable nematode development, but few nematodes, if any, matured; and seven were penetrated with many nematodes maturing. The penetration of nonhosts may imply some susceptibility and that populations eventually would build up on the penetrated plants. Plants not penetrated may be useful as rotation plants because no reproduction would occur. PMID:19290137

  11. Exogenous Modulation of Retinoic Acid Signaling Affects Adult RGC Survival in the Frog Visual System after Optic Nerve Injury

    PubMed Central

    Duprey-Díaz, Mildred V.; Blagburn, Jonathan M.; Blanco, Rosa E.

    2016-01-01

    After lesions to the mammalian optic nerve, the great majority of retinal ganglion cells (RGCs) die before their axons have even had a chance to regenerate. Frog RGCs, on the other hand, suffer only an approximately 50% cell loss, and we have previously investigated the mechanisms by which the application of growth factors can increase their survival rate. Retinoic acid (RA) is a vitamin A-derived lipophilic molecule that plays major roles during development of the nervous system. The RA signaling pathway is also present in parts of the adult nervous system, and components of it are upregulated after injury in peripheral nerves but not in the CNS. Here we investigate whether RA signaling affects long-term RGC survival at 6 weeks after axotomy. Intraocular injection of all-trans retinoic acid (ATRA), the retinoic acid receptor (RAR) type-α agonist AM80, the RARβ agonist CD2314, or the RARγ agonist CD1530, returned axotomized RGC numbers to almost normal levels. On the other hand, inhibition of RA synthesis with disulfiram, or of RAR receptors with the pan-RAR antagonist Ro-41-5253, or the RARβ antagonist LE135E, greatly reduced the survival of the axotomized neurons. Axotomy elicited a strong activation of the MAPK, STAT3 and AKT pathways; this activation was prevented by disulfiram or by RAR antagonists. Finally, addition of exogenous ATRA stimulated the activation of the first two of these pathways. Future experiments will investigate whether these strong survival-promoting effects of RA are mediated via the upregulation of neurotrophins. PMID:27611191

  12. Penetration of nanoparticles into human skin.

    PubMed

    Liang, Xiao Wen; Xu, Zhi Ping; Grice, Jeffrey; Zvyagin, Andrei V; Roberts, Michael S; Liu, Xin

    2013-01-01

    Exposure of human skin to nanoparticles (NPs) is increasing with the development of nanotechnology and new applications of NPs in medicine. Safety concerns have sparked debate on the capacity of NPs to penetrate through skin and enter into the body. This article attempts to summarize the recent evidence on whether NPs penetrate human skin and the factors that may affect the penetration. Skin structure and penetration mechanisms are reviewed to provide background information. Size, shape, formulation, surface properties and application methods and their effects on skin penetration are specifically discussed. Finally, the relationship between skin penetration and nanotoxicity is reviewed to further emphasise the importance of the research in this area.

  13. Akon - A Penetrator for Europa

    NASA Astrophysics Data System (ADS)

    Jones, Geraint

    2016-04-01

    Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

  14. Predicting light penetration into river waters

    NASA Astrophysics Data System (ADS)

    Davies-Colley, Robert J.; Nagels, John W.

    2008-09-01

    Lighting in rivers often needs to be quantified, particularly for modeling benthic plant growth, but is seldom measured because of difficulties associated with limited depth and strong currents. Therefore, methods for predicting light attenuation from river water quality data would be very useful. We used measurements of the diffuse light attenuation coefficient, Kd (m-1), at 17 optically diverse rivers in New Zealand to develop simple empirical models of light penetration as functions of the beam attenuation coefficient at 550 nm, c550 (m-1, an index of visual water clarity) and the light absorption coefficient of membrane filtrates at 340 nm, g340 (m-1, an index of colored dissolved organic matter). The beam attenuation coefficient can be measured by beam transmissometer or estimated, as in this study, from black disc visibility observations. Alternatively, nephelometric turbidity, Tn (an index of light scattering), which is more commonly measured in water quality monitoring programs, can be used to predict Kd. The models performed satisfactorily when tested over a wide range of optical water quality (varying with flow) at one river site. We expect that these empirical models will have wide practical application for estimating light availability in rivers and streams.

  15. IPMN penetration of the stomach.

    PubMed

    Nakano, Masakazu; Tominaga, Keiichi; Watanabe, Hidetaka; Kanke, Kazunari; Tamano, Masaya; Hiraishi, Hideyuki

    2010-01-01

    An 83-year old Japanese man was transferred to our hospital due to a 1-week history of melena and signs of disordered awareness. Esophagogastroduodenoscopy showed a villous tumor associated with massive white mucous discharge in the posterior wall of the gastric corpus, where pathologically identified mucin-producing epithelium with nuclear atypia had developed into a papillary form. An abdominal enhanced computed tomography scan demonstrated communication between the dilated main pancreatic duct and the gastric lumen. Based on these findings, we reached a diagnosis of gastric penetration by an intraductal papillary mucinous neoplasm (IPMN) of the main pancreatic duct. IPMN is partly characterized by expansive mucinous growth that may result in penetration into adjacent organs.

  16. Computational Model for Armor Penetration

    DTIC Science & Technology

    1987-10-01

    the penetration calculation with a slide line in the target, the impact velocity was artificially raised to avoid impact of the projectile sides onto...Lagrangian equations governing motion of a continuous medium. The solution technique is called the method of artificial viscosity because of the...fronts, although no discontinuities occur in the computed flow field. With this artificial viscosity method, the equations of continuous flow can be

  17. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  18. Fragment Penetration Tests of Armor

    DTIC Science & Technology

    1983-03-15

    Identify by block numbhr) Provides techniques for evaluating armor resistance to attack by HE projectile fragments. Includes static detonations of shell...DISTRIBUTION D. REFERENCES * . . . ........ . ........... D-1 1. SCOPE. This TOP describes the available techniques for testing armor for resistance to attack by...Projectiles Against Armor Plates ("Yankee Stadium" Test-). 4.1.1 hCjective. The objective is to determine the resistance to penetration of various armor

  19. Penetration Enzymes of Schistosome Cercariae.

    DTIC Science & Technology

    1982-10-12

    82 10 29 025 SUMMARY In view of the facts that schistosomiasis Is one of man’s most important infectious tropical diseases and that our present...schistosomules; *: (4) differences in intraspecific geographical strains of Schistosoma mansoni ; and (5) snail-parasite relationships. (1) Cercarial Enzymes...of schistosomiasis , a critical stage in the infective process needing elucidation is the transformation In skin of the penetrating cercarlae to the

  20. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  1. Liquid penetration of barrier materials

    NASA Astrophysics Data System (ADS)

    Miller, Angela Maria

    1998-12-01

    Liquid penetration of porous materials is important for applications such as protective clothing, resin impregnation of fibers for composites, and filtration. A test apparatus for determining pressure at liquid breakthrough as a function of flow rate has been designed and constructed. Using this method, it was determined that liquid penetration of a material produces an interesting pressure curve where liquid breakthrough is followed by a peak in pressure and then a drop corresponding to equilibrium flow. This test method allows for comparison of materials in terms of barrier performance and also gives insight into the liquid saturation process. Three materials were tested with water as challenge liquids of varying viscosity and wettability. It was determined that pressure at liquid breakthrough was not dependent on the flow rate nor the viscosity of the challenge liquid but was dependent on the wettability of the challenge liquid. Also of interest was that more passages were opened through the material as flow rate was increased. A numerical model of liquid penetration of a barrier material was created based on invasion percolation. The model has been shown to be consistent with experimental results.

  2. Behavior of Segmented Rods during Penetration

    DTIC Science & Technology

    1990-07-01

    full-scale penetrators which had been swaged 24%. The density of this tungsten alloy was 17.2 Mg/m 3. Gold-alloy penetrators were composed of 92Au-4.9Ag...of behavior. Segmented rods of tungsten alloy always penetrated less than the equivalent unitary rod. Successive rod segments were found to...gold-alloy penetrators because unitary rods of this material surpassed the perform- ance of unitary tungsten -alloy rods, while leaving almost no

  3. Assessment of the frequency-domain multi-distance method to evaluate the brain optical properties: Monte Carlo simulations from neonate to adult

    PubMed Central

    Dehaes, Mathieu; Grant, P. Ellen; Sliva, Danielle D.; Roche-Labarbe, Nadège; Pienaar, Rudolph; Boas, David A.; Franceschini, Maria Angela; Selb, Juliette

    2011-01-01

    The near infrared spectroscopy (NIRS) frequency-domain multi-distance (FD-MD) method allows for the estimation of optical properties in biological tissue using the phase and intensity of radiofrequency modulated light at different source-detector separations. In this study, we evaluated the accuracy of this method to retrieve the absorption coefficient of the brain at different ages. Synthetic measurements were generated with Monte Carlo simulations in magnetic resonance imaging (MRI)-based heterogeneous head models for four ages: newborn, 6 and 12 month old infants, and adult. For each age, we determined the optimal set of source-detector separations and estimated the corresponding errors. Errors arise from different origins: methodological (FD-MD) and anatomical (curvature, head size and contamination by extra-cerebral tissues). We found that the brain optical absorption could be retrieved with an error between 8–24% in neonates and infants, while the error increased to 19–44% in adults over all source-detector distances. The dominant contribution to the error was found to be the head curvature in neonates and infants, and the extra-cerebral tissues in adults. PMID:21412461

  4. Network Penetration Testing and Research

    NASA Technical Reports Server (NTRS)

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised

  5. Adaptive plasticity of the auditory space map in the optic tectum of adult and baby barn owls in response to external ear modification.

    PubMed

    Knudsen, E I; Esterly, S D; Olsen, J F

    1994-01-01

    1. This study demonstrates the influence of experience on the establishment and maintenance of the auditory map of space in the optic tectum of the barn owl. Auditory experience was altered either by preventing the structures of the external ears (the facial ruff and preaural flaps) from appearing in baby barn owls (baby ruff-cut owls) or by removing these structures in adults (adult ruff-cut owls). These structures shape the binaural cues used for localizing sounds in both the horizontal and vertical dimensions. 2. The acoustic effects of removing the external ear structures were measured using probe tube microphones placed in the ear canals. In both baby and adult ruff-cut owls, the spatial pattern of binaural localization cues was dramatically different from normal: interaural level difference (ILD) changed with azimuth instead of with elevation, the rate of change of ILD across space was decreased relative to normal, and the rate of change of interaural time difference (ITD) across frontal space was increased relative to normal. 3. The neurophysiological representations of ITD and ILD in the optic tectum were measured before and > or = 3 mo after ruff removal in adults and beginning at 4.5 months of age in baby ruff-cut owls. Multiunit tuning to ITD and to ILD was measured using dichotic stimulation in ketamine-anesthetized owls. The tectal maps of ITD and ILD were reconstructed using visual receptive field location as a marker for recording site location in the optic tectum. 4. Adjustment of the tectal map of ITD to the altered spatial pattern of acoustic ITD was essentially complete in adults as well as in baby ruff-cut owls. This adjustment changed the magnification of ITD across the tectum, with resultant changes in ITD tuning at individual tectal sites of up to approximately 25 microseconds (approximately 5% of the physiological range) relative to normal values. 5. Adaptation of the tectal ILD map to the ruff-cut spatial pattern of acoustic ILD was

  6. Standard Penetration Test and Relative Density

    DTIC Science & Technology

    1971-02-01

    penetration resistan ( e of soil, an empirical relation was established between the number of blows applied in the standard pene- tration test to sand below...more to a change in the mean grain diameter than did the pene- trometer in the standard penetration test. CONC LUSIONS In the standard penetration

  7. Effect of compressibility on the hypervelocity penetration

    NASA Astrophysics Data System (ADS)

    Song, W. J.; Chen, X. W.; Chen, P.

    2017-06-01

    We further consider the effect of rod strength by employing the compressible penetration model to study the effect of compressibility on hypervelocity penetration. Meanwhile, we define different instances of penetration efficiency in various modified models and compare these penetration efficiencies to identify the effects of different factors in the compressible model. To systematically discuss the effect of compressibility in different metallic rod-target combinations, we construct three cases, i.e., the penetrations by the more compressible rod into the less compressible target, rod into the analogously compressible target, and the less compressible rod into the more compressible target. The effects of volumetric strain, internal energy, and strength on the penetration efficiency are analyzed simultaneously. It indicates that the compressibility of the rod and target increases the pressure at the rod/target interface. The more compressible rod/target has larger volumetric strain and higher internal energy. Both the larger volumetric strain and higher strength enhance the penetration or anti-penetration ability. On the other hand, the higher internal energy weakens the penetration or anti-penetration ability. The two trends conflict, but the volumetric strain dominates in the variation of the penetration efficiency, which would not approach the hydrodynamic limit if the rod and target are not analogously compressible. However, if the compressibility of the rod and target is analogous, it has little effect on the penetration efficiency.

  8. Toody-Wondy calculations of penetration events

    NASA Astrophysics Data System (ADS)

    Hicks, D. L.; Norwood, F. R.; Trucano, T. G.

    1982-04-01

    One and two-dimensional Lagrangian wavecode calculations simulating penetration of a conical-nosed steel penetrator into Antelope Lake Tuff are summarized. These calculations are used to investigate the validity of the cylindrical cavity expansion theory, which has been used to simplify the analysis of earth-penetration events.

  9. TOODY-WONDY calculations of penetration events

    SciTech Connect

    Hicks, D.L.; Norwood, F.R.; Trucano, T.G.

    1981-01-01

    One- and two-dimensional Lagrangian wavecode calculations simulating penetration of a conical-nosed steel penetrator into Antelope Lake Tuff are summarized. These calculations are used to investigate the validity of the cylindrical cavity expansion theory, which has been used to simplify the analysis of earth-penetration events.

  10. FAA Fluorescent Penetrant Activities - An Update

    SciTech Connect

    Moore, D.G.

    1998-10-20

    The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently characterizing low cycle fatigue specimens that will support the needs of penetrant manufacturers, commercial airline industry and the Federal Aviation Administration. The main focus of this characterization is to maintain and enhance the evaluation of penetrant inspection materials and apply resources to support the aircraft community needs. This paper discusses efforts to-date to document the Wright Laboratory penetrant evaluation process and characterize penetrant brightness readings in the initial set of sample calibration panels using Type 1 penetrant.

  11. Determination of folate in infant formula and adult/pediatric nutritional formula by optical biosensor assay: First Action 2011.05.

    PubMed

    Indyk, Harvey; Dowell, Dawn

    2012-01-01

    After a review of data from a single-laboratory validation (SLV) study published in the International Dairy Journal 21, 783-789 (2011), a method for folate in infant formula and adult/pediatric nutritional formula was submitted for consideration of adoption by AOAC as an automated assay that is rapid and simple. The method uses an optical biosensor assay to quantitate total folate content in milk and milk-based pediatric and adult nutritional products. The assay uses folate binding protein and a functionalized sensor surface. The SLV showed an instrumental LOD of 0.1 ng/mL (equivalent to 2.5 microg/100 g for a typical infant formula). The method detection limit was 6.5 microg/100 g with a repeatability of 3.48% and an intermediate reproducibility of 4.63% RSD.

  12. [Reparative Neurogenesis in the Brain and Changes in the Optic Nerve of Adult Trout Oncorhynchus mykiss after Mechanical Damage of the Eye].

    PubMed

    Puschina, E V; Varaksin, A A; Obukhov, D K

    2016-01-01

    Reparative proliferation and neurogenesis in the brain integrative centers after mechanical eye injury in an adult trout Oncorhynchus mykiss have been studied. We have found that proliferation and neurogenesis in proliferative brain regions, the cerebellum, and the optic tectum were significantly enhanced after the eye injury. The cerebellum showed a significant increase in the proliferative activity of the cells of the dorsal proliferative zone and parenchymal cells of the molecular and granular layers. One week after the injury, PCNA-positive radial glia cells have been identified in the tectum. We have found for the first time that the eye trauma resulted in the development of local clusters of undifferentiated cells forming so called neurogenic niches in the tectum and cerebellum. The differentiation of neuronal cells detected by labeling cells with antibodies against the protein HuC/D occurred in the proliferative zones of the telencephalon, the optic tectum, cerebellum, and medulla of a trout within 2 days after the injury. We have shown that the HuC/D expression is higher in the proliferative brain regions than in the definitive neurons of a trout. In addition, we have examined cell proliferation, migration, and apoptosis caused by the eye injury in the contra- and ipsilateral optic nerves and adjacent muscle fibers 2 days after the trauma. The qualitative and quantitative assessment of proliferation and apoptosis in the cells of the optic nerve of a trout has been made using antibodies against PCNA and the TUNEL method.

  13. Management of penetrating brain injury.

    PubMed

    Kazim, Syed Faraz; Shamim, Muhammad Shahzad; Tahir, Muhammad Zubair; Enam, Syed Ather; Waheed, Shahan

    2011-07-01

    Penetrating brain injury (PBI), though less prevalent than closed head trauma, carries a worse prognosis. The publication of Guidelines for the Management of Penetrating Brain Injury in 2001, attempted to standardize the management of PBI. This paper provides a precise and updated account of the medical and surgical management of these unique injuries which still present a significant challenge to practicing neurosurgeons worldwide. The management algorithms presented in this document are based on Guidelines for the Management of Penetrating Brain Injury and the recommendations are from literature published after 2001. Optimum management of PBI requires adequate comprehension of mechanism and pathophysiology of injury. Based on current evidence, we recommend computed tomography scanning as the neuroradiologic modality of choice for PBI patients. Cerebral angiography is recommended in patients with PBI, where there is a high suspicion of vascular injury. It is still debatable whether craniectomy or craniotomy is the best approach in PBI patients. The recent trend is toward a less aggressive debridement of deep-seated bone and missile fragments and a more aggressive antibiotic prophylaxis in an effort to improve outcomes. Cerebrospinal fluid (CSF) leaks are common in PBI patients and surgical correction is recommended for those which do not close spontaneously or are refractory to CSF diversion through a ventricular or lumbar drain. The risk of post-traumatic epilepsy after PBI is high, and therefore, the use of prophylactic anticonvulsants is recommended. Advanced age, suicide attempts, associated coagulopathy, Glasgow coma scale score of 3 with bilaterally fixed and dilated pupils, and high initial intracranial pressure have been correlated with worse outcomes in PBI patients.

  14. Management of penetrating brain injury

    PubMed Central

    Kazim, Syed Faraz; Shamim, Muhammad Shahzad; Tahir, Muhammad Zubair; Enam, Syed Ather; Waheed, Shahan

    2011-01-01

    Penetrating brain injury (PBI), though less prevalent than closed head trauma, carries a worse prognosis. The publication of Guidelines for the Management of Penetrating Brain Injury in 2001, attempted to standardize the management of PBI. This paper provides a precise and updated account of the medical and surgical management of these unique injuries which still present a significant challenge to practicing neurosurgeons worldwide. The management algorithms presented in this document are based on Guidelines for the Management of Penetrating Brain Injury and the recommendations are from literature published after 2001. Optimum management of PBI requires adequate comprehension of mechanism and pathophysiology of injury. Based on current evidence, we recommend computed tomography scanning as the neuroradiologic modality of choice for PBI patients. Cerebral angiography is recommended in patients with PBI, where there is a high suspicion of vascular injury. It is still debatable whether craniectomy or craniotomy is the best approach in PBI patients. The recent trend is toward a less aggressive debridement of deep-seated bone and missile fragments and a more aggressive antibiotic prophylaxis in an effort to improve outcomes. Cerebrospinal fluid (CSF) leaks are common in PBI patients and surgical correction is recommended for those which do not close spontaneously or are refractory to CSF diversion through a ventricular or lumbar drain. The risk of post-traumatic epilepsy after PBI is high, and therefore, the use of prophylactic anticonvulsants is recommended. Advanced age, suicide attempts, associated coagulopathy, Glasgow coma scale score of 3 with bilaterally fixed and dilated pupils, and high initial intracranial pressure have been correlated with worse outcomes in PBI patients. PMID:21887033

  15. Microbial Keratitis After Penetrating Keratoplasty.

    PubMed

    Sun, Jen-Pin; Chen, Wei-Li; Huang, Jehn-Yu; Hou, Yu-Chih; Wang, I-Jong; Hu, Fung-Rong

    2017-06-01

    To report the incidence, microbiological profile, graft survival, and determining factors of microbial keratitis after penetrating keratoplasty (PK). Observational case series. The study involved 51 patients (52 eyes) who were treated at a single tertiary referral center during a 10-year period. Retrospective chart review included medical records of all patients diagnosed with microbial keratitis after penetrating keratoplasty at the National Taiwan University Hospital between January 2000 and December 2009. The main outcome measures were incidence of graft infection, microbial profile, and graft survival status. There were 871 PKs performed and 67 episodes in 52 eyes of culture-positive microbial keratitis during the study period. There were 32 infectious episodes (47.8%) in the first year post-PK and 35 episodes (52.2%) after the first year post-PK. Forty-four gram-positive bacterial isolates (57.9%), 17 gram-negative bacterial isolates (22.4%), and 15 fungal isolates (19.7%) were found. Twenty-three (34.3%) grafts remained clear after the infection episode with a mean follow-up of 1127 days (range, 25-3962 days). There was no difference in graft survival rate regarding the original indication of PK or offending pathogen. Suture-related infection was associated with decreased risk of graft failure (P = .02), while the factor associated with increased risk of graft failure was usage of antiglaucoma agents (P = .01). Infectious keratitis after penetrating keratoplasty leads to a high graft failure rate. Such complications can occur before or after the first year post-PK. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. [In vivo fluorescence spectroscopy of human skin: principles and application to penetration measurements].

    PubMed

    Harendt, N; Giese, K; Kölmel, K

    1994-08-01

    The fluorescence properties of untreated human skin and the penetration of topically applied drugs were measured in vivo using a commercially available fluorescence spectrometer which was adapted to in vivo-measurements on skin by means of optical fibres and a remote viewing head. The intensity and characteristics of the intrinsic fluorescences of human skin and their dependences upon several parameters like pigmentation, water content of the skin or depth of the horny layer are shown. The principles of the penetration measurements based on the fluorescence of the skin or the fluorescence of the drug topically applied to the skin are described and measurements of the penetration of some drugs are reported.

  17. Study into penetration speed during laser cutting of brain tissues.

    PubMed

    Yilbas, Z; Sami, M; Patiroglu, T

    1998-01-01

    The applications of CO2 continuous-wave lasers in neurosurgery have become important in recent years. Theoretical considerations of laser applicability in medicine are subsequently confirmed experimentally. To obtain precision operation in the laser cutting process, further theoretical developments and experimental studies need to be conducted. Consequently, in the present study, the heat transfer mechanism taking place during laser-tissue interaction is introduced using Fourier theory. The results obtained from the theoretical model are compared with the experimental results. In connection with this, an experiment is designed to measure the penetration speed during the laser cutting process. The measurement is carried out using an optical method. It is found that both results for the penetration speed obtained from the theory and experiment are in a good agreement.

  18. Penetrating Cardiac Nail Gun Injury in a Child.

    PubMed

    Kulaylat, Afif N; Chesnut, Charles H; Patel, Sunil; Rocourt, Dorothy V; Clark, Joseph B

    2016-08-01

    Nail gun injuries primarily occur in the extremities of adult males as a consequence of accidental occupational trauma. Such injury involving the thorax is much less common, and penetrating cardiac injury secondary to pneumatic nail gun discharge is rare. Although potentially lethal, most cases with cardiac trauma are survivable with expedient surgical intervention. Despite improvements in engineered safety mechanisms, the incidence of nail gun injuries has risen as use of the devices has increased. The widespread availability of these tools to nonprofessional consumers exposes a broader population to the potential hazards associated with these devices. We describe the presentation and successful management of the first reported case of penetrating cardiac nail gun injury in a young child.

  19. Cable Braid Electromagnetic Penetration Model.

    SciTech Connect

    Warne, Larry K.; Langston, William L.; Basilio, Lorena I.; Johnson, W. A.

    2015-06-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles and reciprocity for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also setup in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multipoles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinite periodic planar geometry. This is used in a simplified application of reciprocity to be able to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.

  20. A lightweight ground penetrating radar

    SciTech Connect

    Koppenjan, S.K.; Allen, C.M.; Gardner, D.; Wong, H.R.

    1998-12-31

    The detection of buried objects, particularly unexploded ordnance (UXO), has gained significant interest in the US in the late 1990s. The desire to remediate the thousands of sites worldwide has become an increasing humanitarian concern. The application of radar to this problem has received renewed attention. Bechtel Nevada, Special Technologies Laboratory (STL) has developed several frequency modulated, continuous wave (FM-CW) ground penetrating radar (GPR) units for the US Department of Energy since 1984. To meet these new technical requirements for high resolution data and UXO detection, STL is moving forward with advances to GPR technology, signal processing, and imaging with the development of an innovative system. The goal is to design and fabricate a lightweight, battery operated unit that does not require surface contact and can be operated by a novice user.

  1. Tissue Penetration of Antifungal Agents

    PubMed Central

    Felton, Timothy; Troke, Peter F.

    2014-01-01

    SUMMARY Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection. PMID:24396137

  2. ENAM Mutations with Incomplete Penetrance

    PubMed Central

    Seymen, F.; Lee, K.-E.; Koruyucu, M.; Gencay, K.; Bayram, M.; Tuna, E.B.; Lee, Z.H.; Kim, J.-W.

    2014-01-01

    Amelogenesis imperfecta (AI) is a genetic disease affecting tooth enamel formation. AI can be an isolated entity or a phenotype of syndromes. To date, more than 10 genes have been associated with various forms of AI. We have identified 2 unrelated Turkish families with hypoplastic AI and performed mutational analysis. Whole-exome sequencing identified 2 novel heterozygous nonsense mutations in the ENAM gene (c.454G>T p.Glu152* in family 1, c.358C>T p.Gln120* in family 2) in the probands. Affected individuals were heterozygous for the mutation in each family. Segregation analysis within each family revealed individuals with incomplete penetrance or extremely mild enamel phenotype, in spite of having the same mutation with the other affected individuals. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations. PMID:25143514

  3. Bodily action penetrates affective perception

    PubMed Central

    Rigutti, Sara; Gerbino, Walter

    2016-01-01

    Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

  4. Bodily action penetrates affective perception.

    PubMed

    Fantoni, Carlo; Rigutti, Sara; Gerbino, Walter

    2016-01-01

    Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer's internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer's internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

  5. In-place HEPA filter penetration test

    SciTech Connect

    Bergman, W.; Wilson, K.; Elliott, J.

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  6. The water penetration of different ventilation tubes.

    PubMed

    Ricks, Rupert G; Easto, Rachel; Reddy, Venkat M

    2016-10-01

    The insertion of middle ear ventilation tubes remains one of the most common procedures for ENT surgeons. A common concern amongst patients undergoing such procedures is the effect on their ability to partake in swimming and other water sports. Currently there is little evidence comparing the penetration ability of different water solutions encountered by swimmers. This study compares the water penetration of four different water solutions for Shah, mini-Shah, T tube and titanium bobbin ventilation tubes. A model was constructed to replicate a grommet inserted through a tympanic membrane using a syringe barrel, latex membrane and one of the ventilation tubes. Four solutions (sea water, chlorinated water, freshwater and soapy water) were then pipetted down the barrel until penetration of the tube occurred. The volume required for penetration was recorded. For all tubes soapy water was the most penetrating, followed by seawater. Titanium bobbins required significantly less of each solution for penetration. Mini-Shah grommets required significantly more of all solutions except soapy water for penetration to occur. Shah grommets were more resistant to chlorinated and sea water than T tubes. Mini-Shah grommets appear to protect against water penetration into the middle ear cleft and their use should be considered in patients who are keen water-sport enthusiasts. Furthermore, swimmers in sea or chlorinated water seem to be at higher risk than freshwater swimmers. Titanium bobbins were relatively easily penetrated by all four solutions and should be avoided in keen swimmers.

  7. Ground Penetrating Radar in Hydrogeophysics

    SciTech Connect

    Hubbard, Susan; Lambot, S.; Binley, A.; Slob, E.; Hubbard, S.

    2008-01-15

    To meet the needs of a growing population and to provide us with a higher quality of life, increasing pressures are being placed on our environment through the development of agriculture, industry, and infrastructures. Soil erosion, groundwater depletion, salinization, and pollution have been recognized for decades as major threats to ecosystems and human health. More recently, the progressive substitution of fossil fuels by biofuels for energy production and climate change have been recognized as potential threats to our water resources and sustained agricultural productivity. The vadose zone mediates many of the processes that govern water resources and quality, such as the partition of precipitation into infiltration and runoff , groundwater recharge, contaminant transport, plant growth, evaporation, and energy exchanges between the Earth's surface and its atmosphere. It also determines soil organic carbon sequestration and carbon-cycle feedbacks, which could substantially impact climate change. The vadose zone's inherent spatial variability and inaccessibility precludes direct observation of the important subsurface processes. In a societal context where the development of sustainable and optimal environmental management strategies has become a priority, there is a strong prerequisite for the development of noninvasive characterization and monitoring techniques of the vadose zone. In particular, hydrogeophysical approaches applied at relevant scales are required to appraise dynamic subsurface phenomena and to develop optimal sustainability, exploitation, and remediation strategies. Among existing geophysical techniques, ground penetrating radar (GPR) technology is of particular interest for providing high-resolution subsurface images and specifically addressing water-related questions. Ground penetrating radar is based on the transmission and reception of VHF-UHF (30-3000 MHz) electromagnetic waves into the ground, whose propagation is determined by the soil

  8. [Penetrating air gun pellet into the orbital apex].

    PubMed

    Belmonte-Caro, Rodolfo; Garcia-Perla-Garcia, Alberto; Romero-Arce, Jose; Infante-Cossio, Pedro

    2017-04-14

    A foreign body penetrating into the intraconal orbital compartment poses a surgical challenge because of its deep location behind the globe and near the optic nerve. We present a case of an air gun pellet lodged into the orbital apex, which was removed via superolateral orbitotomy through coronal incision. This additional craniofacial technique is a safe procedure to access the lateral aspect of the intraconal compartment in the unusual event of having to remove an orbital foreign body. Copyright © 2017 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Enabling kinetic micro-penetrator technology for Solar System research

    NASA Astrophysics Data System (ADS)

    Gowen, R. A.

    2008-09-01

    , to e.g. simple fins for bodies with atmospheres Whilst a 2Kg payload may be considered to be very low mass we propose that it is sufficient to carry out a comprehensive range of scientific investigations of the highest priority, and can include a chemistry package (e.g. mass spectrometer with drill, doped optical fibres), micro-seismometers and accelerometers, together with a package of environment sensors capable of measuring temperature, heat flow, dielectric constant, radiation levels, magnetic fields, and a descent camera. Other very low mass options also include a subsurface mineralogy/astrobiology camera; simple redox and pH instruments; and a beeping transmitter to allow radio interferometery from Earth to detect surface motions whether seismic or tidally induced. At present most of these payload instruments either have good space heritage but no impact qualification; are very simple; or have been fully space qualified with the previous space hardware developments. The UK penetrator consortium is currently actively pursuing a program to provide full space qualification for most of the above instruments, of which sensor elements of the mass spectrometer, prototype drill component, micro-seismometers, magnetometer, radiation sensors have currently survived the recent (May 2008) impact test at 310ms-1with a worst case 8- 10 degrees attack angle (offset between velocity vector and normal incidence angle) where forces in excess of 10Kgee were experienced. Such a payload is capable of significant sub-surface chemical inventory identification including refactory, organic materials; seismic investigations of the interior of active bodies; sub-surface mechanical information including layering from accelerometers and mineralogy/astrobiology camera, and ground truth from orbiting experiments such as dielectric constant which is particularly relevant to orbiting ground penetrating radar measurements. A descent camera can provide both impact site geophysical context as

  10. Ultrasonic/Sonic Impacting Penetrators

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Stark, Randall A.

    2008-01-01

    Ultrasonic/sonic impacting penetrators (USIPs) are recent additions to the series of apparatuses based on ultrasonic/sonic drill corers (USDCs). A USIP enables a rod probe to penetrate packed soil or another substance of similar consistency, without need to apply a large axial force that could result in buckling of the probe or in damage to some buried objects. USIPs were conceived for use in probing and analyzing soil to depths of tens of centimeters in the vicinity of buried barrels containing toxic waste, without causing rupture of the barrels. USIPs could also be used for other purposes, including, for example, searching for pipes, barrels, or other hard objects buried in soil; and detecting land mines. USDCs and other apparatuses based on USDCs have been described in numerous previous NASA Tech Briefs articles. The ones reported previously were designed, variously, for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. To recapitulate: A USDC can be characterized as a lightweight, low-power, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. As shown in the figure, a basic USDC includes a piezoelectric stack, a backing and a horn connected to the stack, a free mass (free in the sense that it can slide axially a short distance between the horn and the shoulder of tool bit), and a tool bit, i.e., probe for USIP. The piezoelectric stack is driven at the resonance frequency of the stack/horn/backing assembly to create ultrasonic vibrations that are mechanically amplified by the horn. To prevent fracture during operation, the piezoelectric stack is held in compression by a bolt. The bouncing of the free mass between the horn and the tool bit at sonic frequencies generates hammering actions to the bit that are more effective for drilling than is the microhammering action of ultrasonic vibrations in ordinary ultrasonic drills. The hammering actions

  11. Surface keratopathy after penetrating keratoplasty.

    PubMed

    Feiz, V; Mannis, M J; Kandavel, G; McCarthy, M; Izquierdo, L; Eckert, M; Schwab, I R; Torabian, S; Wang, J L; Wang, W

    2001-01-01

    To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium. Prospective cohort study. We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy. Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also associated with an increased

  12. Surface keratopathy after penetrating keratoplasty.

    PubMed Central

    Feiz, V; Mannis, M J; Kandavel, G; McCarthy, M; Izquierdo, L; Eckert, M; Schwab, I R; Torabian, S; Wang, J L; Wang, W

    2001-01-01

    PURPOSE: To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium. DESIGN: Prospective cohort study. METHODS: We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy. RESULTS: Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also

  13. Social Penetration: A Description, Research, and Evaluation.

    ERIC Educational Resources Information Center

    Allensworth, Nicole J.

    Social penetration has been described by S.W. Littlejohn (1992) as "the process of increasing disclosure and intimacy in a relationship." The phrase "social penetration" originated with I. Altman and D. Taylor, the foremost researchers in this area. From other theories, Altman and Taylor developed a unified theory which…

  14. Tungsten-uranium penetrator target interaction

    NASA Astrophysics Data System (ADS)

    Dunn, P. S.; Damkroger, B. K.

    Several studies performed in recent years have been directed at determining the penetration mechanism of long rod kinetic energy penetrators into Rolled Homogeneous Armor (RHA). Much of the work has centered on comparing U-0.75Ti and Tungsten Heavy Alloys (WHA), with the goal being to relate the superior ballistic performance of the uranium materials to a fundamental difference in penetration mechanisms. This has been found to be true, with the dominant mechanisms being adiabatic shear in U-0.75Ti and bulk deformation in WHA. Recent work has sought to achieve improvements in the ballistic performance of the tungsten materials via both mechanical property improvements and alloy modifications designed to bring about adiabatic shear. As an alternative, the authors propose the consideration of materials which utilize mechanisms other than bulk deformation and adiabatic shear to optimize ballistic performance. This paper will present the postmortem analysis of a uranium-20 vol% tungsten composite penetrator fired into RHA at 0 degree obliquity. The analysis shows that the penetration mechanism in this material is bulk heating and extensive co-melting of the target and penetrator at the penetration interface. The results of the analysis will then be compared to a similar analysis made of targets into which U-0.75Ti penetrators had been fired.

  15. FRACTIONAL PENETRATION OF PAINT OVERSPRAY ARRESTORS

    EPA Science Inventory

    The report describes the development of fractional penetration curves for liquid droplet penetration of overspray arrestors for discrete droplet diameters from 0.3 to 10 micrometers. (NOTE: Fine particulates are particles with diameters of 10 micrometers or less.) These data poin...

  16. Fluorescent penetration enhancers for transdermal applications.

    PubMed

    Seto, Jennifer E; Polat, Baris E; VanVeller, Brett; Lopez, Renata F V; Langer, Robert; Blankschtein, Daniel

    2012-02-28

    Chemical penetration enhancers are often used to enhance transdermal drug delivery. However, the fundamental mechanisms that govern the interactions between penetration enhancers and skin are not fully understood. Therefore, the goal of this work was to identify naturally fluorescent penetration enhancers (FPEs) in order to utilize well-established fluorescence techniques to directly study the behavior of FPEs within skin. In this study, 12 fluorescent molecules with amphiphilic characteristics were evaluated as skin penetration enhancers. Eight of the molecules exhibited significant activity as skin penetration enhancers, determined using skin current enhancement ratios. In addition, to illustrate the novel, direct, and non-invasive visualization of the behavior of FPEs within skin, three case studies involving the use of two-photon fluorescence microscopy (TPM) are presented, including visualizing glycerol-mitigated and ultrasound-enhanced FPE skin penetration. Previous TPM studies have indirectly visualized the effect of penetration enhancers on the skin by using a fluorescent dye to probe the transdermal pathways of the enhancer. These effects can now be directly visualized and investigated using FPEs. Finally, future studies are proposed for generating FPE design principles. The combination of FPEs with fluorescence techniques represents a useful novel approach for obtaining physical insights on the behavior of penetration enhancers within the skin. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Fluorescent Penetration Enhancers for Transdermal Applications

    PubMed Central

    Seto, Jennifer E.; Polat, Baris E.; VanVeller, Brett; Lopez, Renata F.V.; Langer, Robert; Blankschtein, Daniel

    2011-01-01

    Chemical penetration enhancers are often used to enhance transdermal drug delivery. However, the fundamental mechanisms that govern the interactions between penetration enhancers and skin are not fully understood. Therefore, the goal of this work was to identify naturally fluorescent penetration enhancers (FPEs) in order to utilize well-established fluorescence techniques to directly study the behavior of FPEs within skin. In this study, 12 fluorescent molecules with amphiphilic characteristics were evaluated as skin penetration enhancers. Eight of the molecules exhibited significant activity as skin penetration enhancers, determined using skin current enhancement ratios. In addition, to illustrate the novel, direct, and non-invasive visualization of the behavior of FPEs within skin, three case studies involving the use of two-photon fluorescence microscopy (TPM) are presented, including visualizing glycerol-mitigated and ultrasound-enhanced FPE skin penetration. Previous TPM studies have indirectly visualized the effect of penetration enhancers on skin by using a fluorescent dye to probe the transdermal pathways of the enhancer. These effects can now be directly visualized and investigated using FPEs. Finally, future studies are proposed for generating FPE design principles. The combination of FPEs with fluorescence techniques represents a useful novel approach for obtaining physical insights on the behavior of penetration enhancers within skin. PMID:22062691

  18. FRACTIONAL PENETRATION OF PAINT OVERSPRAY ARRESTORS

    EPA Science Inventory

    The report describes the development of fractional penetration curves for liquid droplet penetration of overspray arrestors for discrete droplet diameters from 0.3 to 10 micrometers. (NOTE: Fine particulates are particles with diameters of 10 micrometers or less.) These data poin...

  19. Stepped frequency ground penetrating radar

    DOEpatents

    Vadnais, Kenneth G.; Bashforth, Michael B.; Lewallen, Tricia S.; Nammath, Sharyn R.

    1994-01-01

    A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass filter. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.

  20. Grepafloxacin: pharmacokinetics and tissue penetration.

    PubMed

    Wise, Richard

    1998-03-01

    Pharmacokinetic and tissue penetration studies of grepafloxacin, a new broad-spectrum fluoroquinolone, show that it has useful properties for the treatment of respiratory tract infections. Grepafloxacin has a volume of distribution that is larger than those of many of the other fluoroquinolones and is concentrated in alveolar macrophages, bronchial mucosa and epithelial lining fluid to a greater extent than are certain other fluoroquinolones. Grepafloxacin concentrations achieved in plasma after a 400-mg oral dose are well in excess of those required to inhibit the respiratory pathogens Staphylococcus aureus, Haemophilus influenzae and Moraxella catarrhalis. Streptococcus pneumoniae is also covered for most of the dosing interval, but at normal dose levels grepafloxacin might not inhibit Enterococcus faecalis. The maximum plasma concentrations and area under the concentration---time curve achieved with grepafloxacin suggest that it will be effective for the treatment of community-acquired pneumonia and acute exacerbations of chronic bronchitis. The pharmacokinetics of fluoroquinolones are among their most useful properties. The aim of this paper is to demonstrate whether the differences between grepafloxacin and the other fluoroquinolones are of therapeutic significance.

  1. Penetrating Wounds of Great Vessels

    PubMed Central

    Symbas, P. N.; Kourias, E.; Tyras, D. H.; Hatcher, C. R.

    1974-01-01

    Thirty-six patients with penetrating wounds of the great vessels treated at Grady Memorial Hospital during a 7-year period were reviewed. In more than 50% of the cases, diagnosis of the injury was made at the time of emergency thoracotomy for massive bleeding. In the remaining patients the diagnosis was suspected: 1) when the pulse distal to the vascular injury was absent or weak; 2) when the patient had symptoms and signs of impaired central nervous system perfusion; 3) when the missile had traversed the mediastinum and there was roentgenographic evidence of widening of the mediastinal shadow; or, 4) when a new murmur appeared. In all suspected cases with great vessel injury, the diagnosis was confirmed arteriographically. Arteriography in such patients should be performed to define the type and site of vascular injury so that its repair can be properly planned. Twenty-nine patients recovered from their injury, 6 succumbed as a result of it and 1 required midforearm amputation following repair of a subclavian artery and vein injury. Most of these patients underwent autotransfusion which greatly contributed to their successful outcome. Local temporary shunt was used for protection of the spinal cord and/or brain when impairment of their perfusion was required for the repair of the vascular wounds. ImagesFig. 1.Fig. 3.Fig. 4. PMID:17859862

  2. Quick-Connect Windowed Non-Stick Penetrator Tips for Rapid Sampling

    NASA Technical Reports Server (NTRS)

    Sherritt, Stewart; Jones, Jack A.; Badescu, Mircea

    2009-01-01

    Standard penetrator sampling systems were designed in order to allow for sampling via penetrators to produce a full set of sample acquisitions including volatile liquids, fine powders, and solid fragments. A gravity harpoon sampler has been designed with a removable tip and a quick coupling. The separation allows for sample handling and eliminates sample cross-contamination. Also, this design allows for multiple use of the penetrator body, which is the largest and heaviest part of the penetrator, while allowing for multiple changes of the light-mass, penetrator tip to avoid sample cross-contamination. The penetrator tip design has been improved by adding a spring trap to retain the sample, as well as a means for connecting to a quick coupling. Quick connect tips have been demonstrated in a sample handling carousel. The penetrator was released and rewound and the tips were released into a circular platter for rotation into instrument stations. The pyro-harpoon sampler was fabricated and tested with a NASA Standard Initiator (NSI) pyrotechnic charge. Initial tests collected cryogenic ice, but removal of the small pyro-harpoon from the ice was difficult. A brass metal sheath was then fitted over the harpoon tip, and removal from the ice was greatly alleviated by leaving the sheath in the ice. Quartz windows in the tips allow direct optical and spectral imaging and gas chromatography-mass spectrometer (GCMS) pyrolysis, and were found to survive impact. All systems were successfully tested by dropping into sand and into cryogenic ice.

  3. Closed Loop Control of Penetration Depth during CO2 Laser Lap Welding Processes

    PubMed Central

    Sibillano, Teresa; Rizzi, Domenico; Mezzapesa, Francesco P.; Lugarà, Pietro Mario; Konuk, Ali Riza; Aarts, Ronald; Veld, Bert Huis in 't; Ancona, Antonio

    2012-01-01

    In this paper we describe a novel spectroscopic closed loop control system capable of stabilizing the penetration depth during laser welding processes by controlling the laser power. Our novel approach is to analyze the optical emission from the laser generated plasma plume above the keyhole, to calculate its electron temperature as a process-monitoring signal. Laser power has been controlled by using a quantitative relationship between the penetration depth and the plasma electron temperature. The sensor is able to correlate in real time the difference between the measured electron temperature and its reference value for the requested penetration depth. Accordingly the closed loop system adjusts the power, thus maintaining the penetration depth. PMID:23112646

  4. Closed-loop power and focus control of laser welding for full-penetration monitoring.

    PubMed

    Bardin, Fabrice; Cobo, Adolfo; Lopez-Higuera, Jose M; Collin, Olivier; Aubry, Pascal; Dubois, Thierry; Högström, Mats; Nylen, Per; Jonsson, Peter; Jones, Julian D C; Hand, Duncan P

    2005-01-01

    We describe a closed-loop control system ensuring full penetration in welding by controlling the focus position and power of a 4-kW Nd:YAG laser. A focus position monitoring system was developed based on the chromatic aberration of the focusing optics. With the laser power control system we can determine the degree of penetration by analyzing the keyhole image intensity profile. We demonstrate performance in bead-on-plate welding of Inconel 718 and titanium. The focus control system maintained a focal position on tilted and nonflat workpieces, and the penetration monitoring technique successfully controlled the laser power to maintain the full-penetration regime in the presence of linear and step changes of thickness. Finally we discuss the performances and the limits of the systems when applied to a realistic complex aerospace component.

  5. Spatial distribution of penetration depth in Taihu Lake (China) during spring and autumn

    NASA Astrophysics Data System (ADS)

    Zhao, Qiaohua; Wei, Yingzhu; Ouyang, Xiaoran

    2013-07-01

    In the context of remote sensing, sunlight penetration depth is the depth above which 90% of the diffusely reflected irradiance from a water body surface originates. Model algorithms to simulate water quality variables such as chlorophyll a, dissolved organic matter, suspended matter, and Secchi depth are sensitive to the variations of this variable. The penetration depth for Taihu Lake in China, a shallow and turbid lake, was calculated by using a multiple scattering model, and in situ optical measurements were carried out during May and October 2010. The results show that: 1) the penetration depth generally increased from west to east during spring and from southeast to northwest during autumn, reflecting the prevailing wind direction and; 2) there was strong dependence of the penetration depth on the concentration of suspended matter.

  6. Penetration of aflatoxins through isolated human epidermis

    SciTech Connect

    Riley, R.T.; Kemppainen, B.W.; Norred, W.P.

    1985-01-01

    The purpose of this study was to determine if aflatoxin B1 (AFB1) could penetrate through isolated human epidermis (stratum corneum plus viable epidermis). ( UC)AFB1 (7.5-9.3 micrograms) was applied to the stratum corneum of epidermal disks mounted in Teflon diffusion cells. ( UC)AFB1 penetrated chemically unaltered through the isolated epidermis. Chloroform-extractable radioactivity accounted for 82.5 +/- 3.7% of the total penetrating radioactivity in the receptor fluid of the diffusion cells. The rate of penetration was very slow when experiments were conducted under nonoccluded conditions, but was approximately 40 times greater under conditions of occlusion. Penetration after 46 h was less than 0.05% and 3.41% of the applied dose under nonoccluded and occluded conditions, respectively. Total recovery expressed as a percentage of the applied radioactivity was 98.6 +/- 6.4%.

  7. Rapid Treatment of Subungual Onychomycosis Using Controlled Micro Nail Penetration and Terbinafine Solution.

    PubMed

    Bristow, Ivan; Baran, Robert; Score, Michelle

    2016-08-01

    Onychomycosis continues to be a common and intractable problem in adults, often responding poorly to topical treatment due to limited drug penetration of the nail plate. Improving penetration has been attempted previously by chemical and physical means with some success. The authors present three cases of toenail onychomycosis treated topical terbinafine 1% solution using controlled micro-penetration of the nail using a novel intelligent nail drill system which is able to drill nail plate without penetrating the delicate nail bed beneath. The cases illustrate how the device has been successfully employed to deliver the anti-fungal drug directly and rapidly to the site of infection with minimal side effects or complications, whilst maintaining the nail integrity.

    J Drugs Dermatol. 2016;15(8):974-978.

  8. An in vitro skin penetration model for compromised skin: estimating penetration of polyethylene glycol [¹⁴C]-PEG-7 phosphate.

    PubMed

    Dey, Swatee; Rothe, Helga; Page, Leanne; O'Connor, Robert; Farahmand, Sara; Toner, Frank; Marsh, Randy; Wehmeyer, Ken; Zhou, Shaoying

    2015-01-01

    Establishing dermal penetration rates is important to better understand the safety of topically applied materials, especially for premature infant skin with compromised skin barrier function. Skin prematurity involves thinner stratum corneum and underdeveloped epidermis/dermis resulting in decreased barrier function, higher transepidermal water loss and greater chemical penetration, when compared to healthy full-term neonate/adult skin. We developed an in vitro skin penetration model using human ex vivo skin to estimate penetration for premature/compromised skin barrier conditions by tape stripping. Skin barrier deficiency was characterized by transepidermal water loss. Baby wipe lotion containing 5 mg/cm(2) [(14)C]-PEG-7 phosphate was applied 5 times to human skin samples of intact, moderately or highly compromised skin barrier and once at 25 mg/cm(2) over 24 h. Overall penetration of [(14)C]-PEG-7 phosphate was low (<5%) even for highly compromised skin. The absorption rate was higher (p < 0.001) for compromised skin versus intact skin. No significant difference was seen between moderately and highly compromised skin by repeated dosing. Under single-dose conditions, penetration through highly compromised skin was significantly higher compared to intact skin (p = 0.001). Our model demonstrates that even under highly compromised skin conditions, penetration of [(14)C]-PEG-7 phosphate is low (<5%) and only 4-6 times higher compared to mature/intact skin and does not approach 100%. Penetration was unaffected by single or multiple dosing conditions. © 2014 S. Karger AG, Basel.

  9. Review of spectral domain-enhanced depth imaging optical coherence tomography of tumors of the retina and retinal pigment epithelium in children and adults.

    PubMed

    Shields, Carol L; Manalac, Janet; Das, Chandana; Saktanasate, Jarin; Shields, Jerry A

    2015-02-01

    Spectral domain (SD) enhanced depth imaging optical coherence tomography (EDI-OCT) is a useful tool for anatomic, cross-sectional imaging of retinal conditions. The aim was to identify characteristic patterns of retinal and retinal pigment epithelial tumors on EDI-OCT in children and adults. Retrospective review. Analysis of published reports and personal observations using office-based EDI-OCT for adults and portable hand-held SD OCT for infants and children. Using EDI-OCT, retinal tumors such as small retinoblastoma, astrocytic hamartoma, and hemangioblastoma arose abruptly from the retina, immediately adjacent to normal retina. Small exophytic retinoblastoma and retinal hemangioblastoma showed the full-thickness, homogeneous retinal disorganization with surrounding normal retina "draping" over the margins. Retinoblastoma occasionally had intralesional cavities and surrounding subretinal fluid. Hemangioblastoma often had adjacent intraretinal edema and subretinal fluid. Astrocytic hamartoma arose within the nerve fiber layer and sometimes with a "moth-eaten" or cavitary appearance. Retinal pigment epithelial (RPE) lesions such as congenital hypertrophy of RPE appeared flat with shadowing, occasional subretinal cleft, and abrupt photoreceptor loss. Congenital simple hamartoma showed an abrupt elevation from the inner retina with crisp, dark posterior shadowing. Combined hamartoma of the retina/RPE showed vitreoretinal traction causing "sawtooth mini-peak" or gently "maxi-peak" folding of the retina. RPE adenoma often produces remote macular edema or epiretinal membrane and the tumor has an irregular, "rugged" surface with deep shadowing. Enhanced depth imaging optical coherence tomography shows characteristic patterns that are suggestive of certain retinal and RPE tumors.

  10. Military penetrating spine injuries compared with blunt.

    PubMed

    Blair, James A; Possley, Daniel R; Petfield, Joseph L; Schoenfeld, Andrew J; Lehman, Ronald A; Hsu, Joseph R

    2012-09-01

    The nature of blunt and penetrating injuries to the spine and spinal column in a military combat setting has been poorly documented in the literature. To date, no study has attempted to characterize and compare blunt and penetrating spine injuries sustained by American servicemembers. The purpose of this study was to compare the military penetrating spine injuries with blunt spine injuries in the current military conflicts. Retrospective study. All American military servicemembers who have been injured while deployed in Iraq (Operation Iraqi Freedom) and Afghanistan (Operation Enduring Freedom) whose medical data have been entered into the Joint Theater Trauma Registry (JTTR). The JTTR was queried for all American servicemembers sustaining an injury to the spinal column or spinal cord while deployed in Iraq or Afghanistan. These data were manually reviewed for relevant information regarding demographics, mechanism of injury, surgical intervention, and neurologic injury. A total of 598 servicemembers sustained injuries to the spine or spinal cord. Isolated blunt injuries were recorded in 396 (66%) servicemembers and 165 (28%) sustained isolating penetrating injuries. Thirty servicemembers (5%) sustained combined blunt and penetrating injuries to the spine. The most commonly documented injuries were transverse process fractures, compression fractures, and burst fractures in the blunt-injured servicemembers versus transverse process fractures, lamina fractures, and spinous process fractures in those injured with a penetrating injury. One hundred four (17%) servicemembers sustained spinal cord injuries, comprising 10% of blunt injuries and 38% of penetrating injuries (p<.0001). Twenty-eight percent (28%) of blunt-injured servicemembers underwent a surgical procedure compared with 41% of those injured by penetrating mechanisms (p=.4). Sixty percent (n=12/20) of blunt-injured servicemembers experienced a neurologic improvement after surgical intervention at follow

  11. The balance of NMDA- and AMPA/kainate receptor-mediated activity in normal adult goldfish and during optic nerve regeneration.

    PubMed

    Taylor, Andrew L; Rodger, Jennifer; Stirling, R Victoria; Beazley, Lyn D; Dunlop, Sarah A

    2005-10-01

    Retinotectal topography is established during development and relies on the sequential recruitment of glutamate receptors within postsynaptic tectal cells. NMDA receptors underpin plastic changes at early stages when retinal ganglion cell (RGC) terminal arbors are widespread and topography is coarse; AMPA/kainate receptors mediate fast secure neurotransmission characteristic of mature circuits once topography is refined. Here, we have examined the relative contributions of these receptors to visually evoked activity in normal adult goldfish, in which retinotectal topography is constantly adjusted to compensate for the continual neurogenesis and the addition of new RGC arbors. Furthermore, we examined animals at two stages of optic nerve regeneration. In the first, RGC arbors are widespread and receptive fields large resulting in coarse topography; in the second, RGC arbors are pruned to reduce receptive fields leading to refined topography. Antagonists were applied to the tectum during multiunit recording of postsynaptic responses. Normal goldfish have low levels of NMDA receptor-mediated activity and high levels of AMPA/kainate. When coarse topography has been restored, NMDA receptor-mediated activity is increased and that of AMPA/kainate decreased. Once topography has been refined, the balance of NMDA and AMPA/kainate receptor-mediated activity returns to normal. The data suggest that glutamatergic neurotransmission in normal adult goldfish is dual with NMDA receptors fine-tuning topography and AMPA receptors allowing stable synaptic function. Furthermore, the normal operation of both receptors allows a response to injury in which the balance can be transiently reversed to restore topography and vision.

  12. Automated voxel classification used with atlas-guided diffuse optical tomography for assessment of functional brain networks in young and older adults.

    PubMed

    Li, Lin; Cazzell, Mary; Babawale, Olajide; Liu, Hanli

    2016-10-01

    Atlas-guided diffuse optical tomography (atlas-DOT) is a computational means to image changes in cortical hemodynamic signals during human brain activities. Graph theory analysis (GTA) is a network analysis tool commonly used in functional neuroimaging to study brain networks. Atlas-DOT has not been analyzed with GTA to derive large-scale brain connectivity/networks based on near-infrared spectroscopy (NIRS) measurements. We introduced an automated voxel classification (AVC) method that facilitated the use of GTA with atlas-DOT images by grouping unequal-sized finite element voxels into anatomically meaningful regions of interest within the human brain. The overall approach included volume segmentation, AVC, and cross-correlation. To demonstrate the usefulness of AVC, we applied reproducibility analysis to resting-state functional connectivity measurements conducted from 15 young adults in a two-week period. We also quantified and compared changes in several brain network metrics between young and older adults, which were in agreement with those reported by a previous positron emission tomography study. Overall, this study demonstrated that AVC is a useful means for facilitating integration or combination of atlas-DOT with GTA and thus for quantifying NIRS-based, voxel-wise resting-state functional brain networks.

  13. Evaluation of selective treatment of penetrating abdominal trauma.

    PubMed

    Schmelzer, Thomas M; Mostafa, Gamal; Gunter, Oliver L; Norton, H James; Sing, Ronald F

    2008-01-01

    In penetrating abdominal trauma, diagnostic imaging and the application of selective clinical management may avoid negative celiotomy and improve outcome. We prospectively observed patients with penetrating abdominal trauma over 15 months and recorded demographics, presentation, imaging, surgical procedure, and outcome. Patients who underwent immediate laparotomy were compared with patients who were observed and/or had a computed tomography (CT) scan. Outcomes of negative versus positive and immediate versus delayed celiotomy were compared. Chi-square and Student t tests were used. A p value of less than 0.05 was considered significant. A level 1 trauma center. Adult patients who presented with penetrating abdominal injury. In all, 100 consecutive patients (mean age, 32 years) were included (male:female, 91:9; gunshot wound:stab wound, 65:35). Overall, 60 immediate and 10 delayed laparotomies were performed; 30 patients did not undergo surgery. Predictors of immediate celiotomy were hypotension (p = 0.03), anteriorly located entrance wounds (p = 0.0005), and transaxial wounds (p = 0.03). Overall morbidity and mortality was 32% and 2%, respectively. The negative celiotomy rate was 25%. Patients with a positive celiotomy had higher morbidity (p = 0.006) and longer hospital length of stay (p = 0.003) compared with negative celiotomy. A CT scan was employed in 32% of patients, with 100% sensitivity and 94% specificity. Delayed celiotomy (10%) did not adversely impact morbidity (p = 0.70) and was 100% therapeutic, with no deaths. Nonselective immediate celiotomy for penetrating abdominal trauma results in a high rate of unnecessary surgery. Hemodynamically stable patients can safely be observed and/or have contrast CT scans and undergo delayed celiotomy, if indicated. This selective treatment had no adverse effect on patient outcomes and can potentially improve overall outcome.

  14. Penetration depth measurement of near-infrared hyperspectral imaging light for milk powder

    USDA-ARS?s Scientific Manuscript database

    The increasingly common application of near-infrared (NIR) hyperspectral imaging technique to the analysis of food powders has led to the need for optical characterization of samples. This study was aimed at exploring the feasibility of quantifying penetration depth of NIR hyperspectral imaging ligh...

  15. Modeling pollutant penetration across building envelopes

    SciTech Connect

    Liu, De-Ling; Nazaroff, William W.

    2001-04-01

    As air infiltrates through unintentional openings in building envelopes, pollutants may interact with adjacent surfaces. Such interactions can alter human exposure to air pollutants of outdoor origin. We present modeling explorations of the proportion of particles and reactive gases (e.g., ozone) that penetrate building envelopes as air enters through cracks and wall cavities. Calculations were performed for idealized rectangular cracks, assuming regular geometry, smooth inner crack surface and steady airflow. Particles of 0.1-1.0 {micro}m diameter are predicted to have the highest penetration efficiency, nearly unity for crack heights of 0.25 mm or larger, assuming a pressure difference of 4 Pa or greater and a flow path length of 3 cm or less. Supermicron and ultrafine particles are significantly removed by means of gravitational settling and Brownian diffusion, respectively. In addition to crack geometry, ozone penetration depends on its reactivity with crack surfaces, as parameterized by the reaction probability. For reaction probabilities less than {approx}10{sup -5}, penetration is complete for cracks heights greater than 1 mm. However, penetration through mm scale cracks is small if the reaction probability is {approx}10{sup -4} or greater. For wall cavities, fiberglass insulation is an efficient particle filter, but particles would penetrate efficiently through uninsulated wall cavities or through insulated cavities with significant airflow bypass. The ozone reaction probability on fiberglass fibers was measured to be 10{sup -7} for fibers previously exposed to high ozone levels and 6 x 10{sup -6} for unexposed fibers. Over this range, ozone penetration through fiberglass insulation would vary from >90% to {approx}10-40%. Thus, under many conditions penetration is high; however, there are realistic circumstances in which building envelopes can provide substantial pollutant removal. Not enough is yet known about the detailed nature of pollutant penetration

  16. Results of analyses performed on basalt adjacent to penetrators emplaced into volcanic rock at Amboy, California, April 1976

    NASA Technical Reports Server (NTRS)

    Blanchard, M.; Bunch, T.; Davis, A.; Shade, H.; Erlichman, J.; Polkowski, G.

    1977-01-01

    The physical and chemical modifications found in the basalt after impact of four penetrators were studied. Laboratory analyses show that mineralogical and elemental changes are produced in the powdered and crushed basalt immediately surrounding the penetrator. Optical microscopy studies of material next to the skin of the penetrator revealed a layer, 0-2 mm thick, of glass and abraded iron alloy mixed with fractured mineral grains of basalt. Elemental analysis of the 0-2 mm layer revealed increased concentrations of Fe, Cr, Ni, No, and Mn, and reduced concentrations of Mg, Al, Si, and Ca. The Fe, Cr, Ni, and Mo were in fragments abraded from the penetrator. Mineralogical changes occurring in the basalt sediment next to the penetrator include the introduction of micron-size grains of alpha-iron, magnetite, and hematite. The newly formed silicate minerals include metastable phases of silica (tridymite and cristobalite). An increased concentration of Fe, Cr, Ni, and Mo occurred in the 2-mm to 1-cm layer of penetrator no. 1, which impacted at the highest velocity. No elemental concentration increase was noted for penetrators nos. 2 and 3 in the 2-mm to 1-cm layer. Contaminants introduced by the penetrator occur up to 1 cm away from the penetrator's skin. Although volatile elements do migrate and new minerals are formed during the destruction of host minerals in the crushed rock, no changes were observed beyond the 1-cm distance.

  17. Penetrating Orbital Injury From a Needlefish.

    PubMed

    Miller, Kyle E; Coan, Erin B

    2016-08-01

    Orbital penetrating injuries are an unfortunately common occurrence; however, those from marine animals are rare. Injuries from marine animals can be quite profound and there are no known reports of complete visual recovery after an orbital penetrating injury. Complications range from secondary infection to a carotid-cavernous fistula, which can complicate the management of these patients. We report a case of penetrating orbital injury from a needlefish with complete return of visual function after surgical removal of foreign debris and an extended course of antibiotics. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

  18. Aqueous marker penetration into ion irradiated polyimide

    NASA Astrophysics Data System (ADS)

    Fink, D.; Müller, M.; Petrov, A.; Klett, R.; Palmetshofer, L.; Hnatowicz, V.; Vacik, J.; Cervena, J.; Chadderton, L. T.

    2002-05-01

    The penetration of aqueous 6Li + markers into low energy ion irradiated polyimide (PI) foils was examined by the neutron depth profiling technique in combination with a modified tomographic approach. The ion irradiation always leads to an enhancement in marker uptake. After irradiation at low fluence the marker profiles follow the nuclear damage distribution even in three dimensions. At elevated fluences saturation in the marker uptake is clearly seen. The polymer's penetrant uptake can be described well by regular diffusion, with nuclear damage centres acting as saturable traps. These observations are strikingly different from the marker penetration into high-energy heavy-ion irradiated PI.

  19. Earthquakes induced by deep penetrating bombing?

    NASA Astrophysics Data System (ADS)

    Balassanian, Serguei Y.

    2005-11-01

    The data of M≥5 earthquakes occurred in one year before and after 4 deep penetrating bombs in the region within 500 km and 1 000 km from the shooting site are presented. The 4 bombs are those happened in 1999 Kosovo of Yugoslavia, the 1991 Baghdad of Iraq, the 2001 Tora Bora of Afghanistan, and the 2003 Kirkuk of Iraq, respectively. The data indicate that the deep penetrating bombs may have remotely triggered some earthquakes. The deep penetrating bombs in seismically active regions should be forbidden.

  20. Sphere impact and penetration into wet sand.

    PubMed

    Marston, J O; Vakarelski, I U; Thoroddsen, S T

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  1. Sphere impact and penetration into wet sand

    NASA Astrophysics Data System (ADS)

    Marston, J. O.; Vakarelski, I. U.; Thoroddsen, S. T.

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  2. Pressure enhanced penetration with shaped charge perforators

    DOEpatents

    Glenn, Lewis A.

    2001-01-01

    A downhole tool, adapted to retain a shaped charge surrounded by a superatmospherically pressurized light gas, is employed in a method for perforating a casing and penetrating reservoir rock around a wellbore. Penetration of a shaped charge jet can be enhanced by at least 40% by imploding a liner in the high pressure, light gas atmosphere. The gas pressure helps confine the jet on the axis of penetration in the latter stages of formation. The light gas, such as helium or hydrogen, is employed to keep the gas density low enough so as not to inhibit liner collapse.

  3. Miniature Ground Penetrating Radar, CRUX GPR

    NASA Technical Reports Server (NTRS)

    Kim, Soon Sam; Carnes, Steven R.; Haldemann, Albert F.; Ulmer, Christopher T.; Ng, Eddie; Arcone, Steven A.

    2006-01-01

    Under NASA instrument development programs (PIDDP 2000-2002, MIPD 2003-2005, ESR and T, 2005) we have been developing miniature ground penetrating radars (GPR) for use in mapping subsurface stratigraphy from planetary rovers for Mars and lunar applications. The Mars GPR is for deeper penetration (up to 50 m depth) into the Martian subsurface at moderate resolution (0.5 m) for a geological characterization. As a part of the CRUX (Construction and Resource Utilization Explorer) instrument suite, the CRUX GPR is optimized for a lunar prospecting application. It will have shallower penetration (5 m depth) with higher resolution (10 cm) for construction operations including ISRU (in-situ resource utilization).

  4. Simulated meteoroid penetration of reusable surface insulation

    NASA Technical Reports Server (NTRS)

    Lehman, J. K.; Christensen, H. E.

    1973-01-01

    Meteoroid impact simulation test results on insulation tiles were used to determine penetration resistance of reusable surface insulation attached to simulated shuttle structures. The probability of no meteoroid damage to a typical shuttle orbiter was determined. Specimens were plasma jet tested to determine effects of various size meteoroid cavities on their thermal performance. None of the tiles failed catastrophically, but large, egg-shaped craters did result from meteoroid penetration. The metallic side of a specimen that was completely penetrated showed a petalled hole typical for thin gage shielded structures.

  5. Penetrating Dust Tori in AGN

    NASA Astrophysics Data System (ADS)

    Canalizo, G.; Max, C.; Antonucci, R.; Whysong, D.; Stockton, A.; Lacy, M.

    2004-01-01

    We present preliminary results from high resolution (~ 0.05") adaptive optics observations of Cygnus A. The images show a bi-conic structure strongly suggestive of an obscuring torus around a quasar nucleus. A bright (K'=18.5) point source is found near the expected position of the nucleus. We interpret this source as the hot inner rim of the torus seen through the opening of the torus. Using high angular resolution K-band spectroscopy, we measure the ratio of molecular to recombination hydrogen lines as a function of distance to the center of the putative torus. These measurements place constraints on the properties of the torus and indicate a projected diameter of ~600 pc.

  6. Laser weld penetration estimation using temperature measurements

    SciTech Connect

    Lankalapalli, K.N.; Tu, J.F.; Leong, K.H.; Gartner, M.

    1997-10-01

    Penetration depth is an important factor critical to the quality of a laser weld. This paper examines the feasibility of using temperature measurements on the bottom surface of the work-piece to estimate weld penetration. A three-dimensional analytical model relating penetration depth, weld bead width and welding speed to temperature distribution at the bottom surface of the workpiece is developed. Temperatures on the bottom surface of the workpiece are measured using infrared thermocouples located behind the laser beam. Experimental results from bead-on-plate welds on low carbon steel plates of varying thickness at different levels of laser power and speeds validate the model and show that the temperature on the bottom surface is a sensitive indicator of penetration depth. The proposed model is computationally efficient and is suitable for on-line process monitoring application.

  7. Temporary fire sealing of penetrations on TFTR

    SciTech Connect

    Hondorp, H.L.

    1981-02-01

    The radiation shielding provided for TFTR for D-D and D-T operation will be penetrated by numerous electrical and mechanical services. Eventually, these penetrations will have to be sealed to provide the required fire resistance, tritium sealability, pressure integrity and radiation attenuation. For the initial hydrogen operation, however, fire sealing of the penetrations in the walls and floor is the primary concern. This report provides a discussion of the required and desirable properties of a temporary seal which can be used to seal these penetrations for the hydrogen operation and then subsequently be removed and replaced as required for the D-D and D-T operations. Several candidate designs are discussed and evaluated and recommendations are made for specific applications.

  8. Non-normal impact of earth penetrators

    SciTech Connect

    Duffey, T.A.; Macek, R.W.

    1996-12-31

    A brief literature review of the general subject of projectile penetration into soil media is presented. Particular emphasis is placed on projectiles impacting soil targets at other than normal incidence and/or at an angle of attack, for which lateral accelerations exist and can dominate the structural response. Comparisons of predicted lateral accelerations with recent earth penetrator experiments are then made using a 3 degree-of-freedom rigid-body approach developed elsewhere to determine the external penetrator loading. Agreement between experimental and calculated accelerations is favorable, but the need to include flexible-body response is indicated. Finally a scheme to incorporate a spherical-cavity-expansion analytical procedure into a detailed finite element model of the penetrator is developed to account for flexible-body response.

  9. Shaving effects on percutaneous penetration: clinical implications.

    PubMed

    Hamza, Muhammad; Tohid, Hassaan; Maibach, Howard

    2015-01-01

    Human/animal shaving biology. To assess the effect of shaving on percutaneous penetration and skin function. We screened 500+publications in Pub Med, Scopus, Cochrane Library and pertinent journals out of which only 17 were deemed relevant. Terms for searches included shaving and skin, percutaneous penetration and shaving, skin absorption and shaving, absorption of dyes and shaving, skin penetration, effects of shaving and absorption, shave and dyes, axillary shaving and stratum corneum, shaving and breast cancer, shaving and infections, etc. Shaving appears to have an exaggerated effect on percutaneous absorption; however, some studies do not support this evidence. Shaving enhances percutaneous penetration of some chemicals; however this effect is species and chemical specific. Further investigations of chemicals of varying physio-chemical properties are mandated before a generalized theory can be promulgated.

  10. Magnetic field penetration of erosion switch plasmas

    NASA Astrophysics Data System (ADS)

    Mason, Rodney J.; Jones, Michael E.; Grossmann, John M.; Ottinger, Paul F.

    1988-10-01

    Computer simulations demonstrate that the entrainment (or advection) of magnetic field with the flow of cathode-emitted electrons can constitute a dominant mechanism for the magnetic field penetration of erosion switch plasmas. Cross-field drift in the accelerating electric field near the cathode starts the penetration process. Plasma erosion propagates the point for emission and magnetic field injection along the cathode toward the load-for the possibility of rapid switch opening.

  11. Low Force Penetration of Icy Regolith

    NASA Technical Reports Server (NTRS)

    Mantovani, J. G.; Galloway, G. M.; Zacny, K.

    2016-01-01

    A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

  12. Anomalous toroidal field penetration in Tormac V

    SciTech Connect

    Feinberg, B.; Vaucher, B. G.; Shaw, R. S.; Vella, M. C.

    1981-07-01

    We investigate magnetic field penetration into a cool, collisional, magnetized plasma in Tormac V. Magnetic probe and laser interferometer studies reveal anomalous penetration of the applied toroidal field into a plasma with an initial parallel bias toroidal field. The applied poloidal field, however, formed a well-defined magnetic front which was effective at sweeping up particles. Lastly, strong shear in the vacuum magnetic field does not inhibit the apparent decoupling of the applied toroidal field from the applied poloidal field.

  13. Dentinal Tubule Penetration of Tricalcium Silicate Sealers.

    PubMed

    McMichael, Greer E; Primus, Carolyn M; Opperman, Lynne A

    2016-04-01

    The treatments for which mineral trioxide aggregate (MTA)-based materials can be used in dentistry are expanding. Smaller particle size and easier handling properties have allowed the advent of tricalcium silicate sealers including EndoSequence BC Sealer (Brasseler USA, Savannah, GA), QuickSet2 (Avalon Biomed, Bradenton, FL), NeoMTA Plus (Avalon Biomed), and MTA Fillapex (Angelus, Londrina, Brazil). The objective of this study was to measure the tubule penetration with these sealers using continuous wave (CW) and single-cone (SC) obturation techniques. Eighty single-rooted teeth were randomly divided into 8 groups of 10 and obturated with 1 of the previously mentioned sealers mixed with trace amounts of rhodamine using either the CW or SC technique. Teeth were sectioned at 1 mm and 5 mm from the apex and examined under a confocal laser microscope. The percentage of sealer penetration and the maximum sealer penetration were measured. The tricalcium silicate sealers penetrated tubules as deep as 2000 μm (2 mm). The percentage of sealer penetration was much higher 5 mm from the apex, with many specimens having 100% penetration for both SC and warm vertical techniques. MTA Fillapex, a resin-based sealer with less than 20% MTA particles, had significantly greater tubule penetration with a warm vertical technique versus the SC technique at the 1-mm level. Within the limitations of this study, the CW and SC techniques produced similar tubule penetration at both the 1-mm and the 5-mm level with the tricalcium silicate sealers BC Sealer, QuickSet2, and NeoMTA Plus. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Romanomermis culicivorax: penetration of larval mosquitoes.

    PubMed

    Shamseldean, M M; Platzer, E G

    1989-09-01

    In the presence of second larval instars of three mosquito species the preparasites of Romanomermis culicivorax swam near the water surface in an orthokinetic manner. When the preparasites were ca. 1 mm from the host, they stopped and swam klinotactically toward the host. During this phase, the preparasites secreted a small amount of a putative adhesive material from the anterior region and host contact was completed. The adhesive appeared to aid in attachment of the preparasites to the host and initiation of the search-boring phase. The preparasites glided over the host until a suitable penetration site was found. The penetration phase was initiated by probing with the odontostyle. This was followed by partial paralysis, decreased intestinal peristaltic movement, and temporary cardiac arrest in all host mosquitoes which was probably related to injection of esophageal secretions. SEM observations showed that the abdominal walls were the most frequent site for penetration. As the preparasites entered through the penetration hole, microorganisms adhering to the cuticle of the preparasites were retained by the adhesive which accumulated around the penetration site. Thus, microbial contamination of the host was avoided by a mechanical cleansing mechanism. Penetration was usually completed in less than 10 min.

  15. Estimating Consequences of MMOD Penetrations on ISS

    NASA Technical Reports Server (NTRS)

    Evans, H.; Hyde, James; Christiansen, E.; Lear, D.

    2017-01-01

    The threat from micrometeoroid and orbital debris (MMOD) impacts on space vehicles is often quantified in terms of the probability of no penetration (PNP). However, for large spacecraft, especially those with multiple compartments, a penetration may have a number of possible outcomes. The extent of the damage (diameter of hole, crack length or penetration depth), the location of the damage relative to critical equipment or crew, crew response, and even the time of day of the penetration are among the many factors that can affect the outcome. For the International Space Station (ISS), a Monte-Carlo style software code called Manned Spacecraft Crew Survivability (MSCSurv) is used to predict the probability of several outcomes of an MMOD penetration-broadly classified as loss of crew (LOC), crew evacuation (Evac), loss of escape vehicle (LEV), and nominal end of mission (NEOM). By generating large numbers of MMOD impacts (typically in the billions) and tracking the consequences, MSCSurv allows for the inclusion of a large number of parameters and models as well as enabling the consideration of uncertainties in the models and parameters. MSCSurv builds upon the results from NASA's Bumper software (which provides the probability of penetration and critical input data to MSCSurv) to allow analysts to estimate the probability of LOC, Evac, LEV, and NEOM. This paper briefly describes the overall methodology used by NASA to quantify LOC, Evac, LEV, and NEOM with particular emphasis on describing in broad terms how MSCSurv works and its capabilities and most significant models.

  16. Penetration of erythromycin through Staphylococcus epidermidis biofilm.

    PubMed

    Lin, Mao-hu; He, Lei; Gao, Jie; Liu, Yun-xi; Suo, Ji-jiang; Xing, Yu-bin; Jia, Ning

    2013-07-01

    The catheter related infection caused by Staphylococcus epidermidis biofilm is increasing and difficult to treat by antimicrobial chemotherapy. The properties of biofilms that give rise to antibiotic resistance are only partially understood. This study aimed to elucidate the penetration of erythromycin through Staphylococcus epidermidis biofilm. The penetration ratio of erythromycin through Staphylococcus epidermidis biofilms of 1457, 1457-msrA, and wild isolate S68 was detected by biofilm penetration model at different time points according to the standard regression curve. The RNA/DNA ratio and the cell density within the biofilms were observed by confocal laser microscope and transmission electromicroscope, respectively. The penetration ratios of erythromycin through the biofilms of 1457, 1457-msrA, and S68 after cultivation for 36 hours were 0.93, 0.55 and 0.4, respectively. The erythromycin penetration ratio through 1457 biofilm (0.58 after 8 hours) was higher than that through the other two (0.499 and 0.31 after 24 hours). Lower growth rate of the cells in biofilm was shown, with reduction of RNA/DNA proportion observed by confocal laser microscope through acridine orange stain. Compared with the control group observed by transmission electrmicroscope, the cell density of biofilm air face was lower than that of agar face, with more cell debris. Erythromycin could penetrate to the Staphylococcus epidermidis biofilm, but could not kill the cells thoroughly. The lower growth rate of the cells within biofilm could help decreasing the erythromycin susceptibility.

  17. Are cognitive outcome and recovery different in civilian penetrating versus non-penetrating brain injuries?

    PubMed

    Ylioja, Shelley; Hanks, Robin; Baird, Anne; Millis, Scott

    2010-10-01

    The present study sought to determine whether cognitive outcome and course of recovery in civilian penetrating brain injury due to gunshot can be distinguished from that of non-penetrating brain injury due to motor vehicle accident. Matched survivors of penetrating and non-penetrating brain injury were assessed with a brief neuropsychological test battery at inpatient rehabilitation, 1 year post-injury, and 2 years post-injury. The traumatic brain injury groups were found to have patterns of performance marked by reliably distinct differences in isolated areas, with different cognitive predictors of brain injury type present in early versus later recovery. The degree of recovery over the first 2 years appeared to be quite similar for penetrating and non-penetrating injuries.

  18. Whole-body and multispectral photoacoustic imaging of adult zebrafish

    NASA Astrophysics Data System (ADS)

    Huang, Na; Xi, Lei

    2016-10-01

    Zebrafish is a top vertebrate model to study developmental biology and genetics, and it is becoming increasingly popular for studying human diseases due to its high genome similarity to that of humans and the optical transparency in embryonic stages. However, it becomes difficult for pure optical imaging techniques to volumetric visualize the internal organs and structures of wild-type zebrafish in juvenile and adult stages with excellent resolution and penetration depth. Even with the establishment of mutant lines which remain transparent over the life cycle, it is still a challenge for pure optical imaging modalities to image the whole body of adult zebrafish with micro-scale resolution. However, the method called photoacoustic imaging that combines all the advantages of the optical imaging and ultrasonic imaging provides a new way to image the whole body of the zebrafish. In this work, we developed a non-invasive photoacoustic imaging system with optimized near-infrared illumination and cylindrical scanning to image the zebrafish. The lateral and axial resolution yield to 80 μm and 600 μm, respectively. Multispectral strategy with wavelengths from 690 nm to 930 nm was employed to image various organs inside the zebrafish. From the reconstructed images, most major organs and structures inside the body can be precisely imaged. Quantitative and statistical analysis of absorption for organs under illumination with different wavelengths were carried out.

  19. Expressed sequence tag analysis of adult human optic nerve for NEIBank: Identification of cell type and tissue markers

    PubMed Central

    Bernstein, Steven L; Guo, Yan; Peterson, Katherine; Wistow, Graeme

    2009-01-01

    Background The optic nerve is a pure white matter central nervous system (CNS) tract with an isolated blood supply, and is widely used in physiological studies of white matter response to various insults. We examined the gene expression profile of human optic nerve (ON) and, through the NEIBANK online resource, to provide a resource of sequenced verified cDNA clones. An un-normalized cDNA library was constructed from pooled human ON tissues and was used in expressed sequence tag (EST) analysis. Location of an abundant oligodendrocyte marker was examined by immunofluorescence. Quantitative real time polymerase chain reaction (qRT-PCR) and Western analysis were used to compare levels of expression for key calcium channel protein genes and protein product in primate and rodent ON. Results Our analyses revealed a profile similar in many respects to other white matter related tissues, but significantly different from previously available ON cDNA libraries. The previous libraries were found to include specific markers for other eye tissues, suggesting contamination. Immune/inflammatory markers were abundant in the new ON library. The oligodendrocyte marker QKI was abundant at the EST level. Immunofluorescence revealed that this protein is a useful oligodendrocyte cell-type marker in rodent and primate ONs. L-type calcium channel EST abundance was found to be particularly low. A qRT-PCR-based comparative mammalian species analysis reveals that L-type calcium channel expression levels are significantly lower in primate than in rodent ON, which may help account for the class-specific difference in responsiveness to calcium channel blocking agents. Several known eye disease genes are abundantly expressed in ON. Many genes associated with normal axonal function, mRNAs associated with axonal transport, inflammation and neuroprotection are observed. Conclusion We conclude that the new cDNA library is a faithful representation of human ON and EST data provide an initial overview

  20. Collaborative effects of wavefront shaping and optical clearing agent in optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Yu, Hyeonseung; Lee, Peter; Jo, YoungJu; Lee, KyeoReh; Tuchin, Valery V.; Jeong, Yong; Park, YongKeun

    2016-12-01

    We demonstrate that simultaneous application of optical clearing agents (OCAs) and complex wavefront shaping in optical coherence tomography (OCT) can provide significant enhancement of penetration depth and imaging quality. OCA reduces optical inhomogeneity of a highly scattering sample, and the wavefront shaping of illumination light controls multiple scattering, resulting in an enhancement of the penetration depth and signal-to-noise ratio. A tissue phantom study shows that concurrent applications of OCA and wavefront shaping successfully operate in OCT imaging. The penetration depth enhancement is further demonstrated for ex vivo mouse ears, revealing hidden structures inaccessible with conventional OCT imaging.

  1. Multiple scattering model for the penetration depth of low-coherence enhanced backscattering.

    PubMed

    Turzhitsky, Vladimir; Mutyal, Nikhil N; Radosevich, Andrew J; Backman, Vadim

    2011-09-01

    Low-coherence enhanced backscattering (LEBS) is a depth-selective self-interference phenomenon that originates from light traveling time-reversed paths in a scattering medium. The depth selectivity of LEBS and its sensitivity to optical properties of the scattering medium has made it a promising technique for probing the structure of biological tissue with applications to disease diagnosis and, in particular, precancerous conditions. The ability to accurately predict the penetration depth of the LEBS signal is important in targeting an optimal tissue depth for detecting precancerous cells. This prediction is further complicated by the variation in optical properties of different tissue types. In this paper, the effects of the reduced scattering coefficient (μ(s)'), the phase function and the instrument spatial coherence length (L(sc)) on the LEBS penetration depth are quantified. It is determined that the LEBS penetration depth is primarily dependent on L(sc), μ(s)', and the anisotropy factor (g), but has minimal dependence on higher moments of the phase function. An empirical expression, having a similar form as the double scattering approximation for LEBS, is found to accurately predict the average penetration depth in the multiple scattering regime. The expression is shown to be accurate for a broad range of experimentally relevant optical properties and spatial coherence lengths.

  2. Dynamics of crack penetration vs. branching at a weak interface: An experimental study

    NASA Astrophysics Data System (ADS)

    Sundaram, Balamurugan M.; Tippur, Hareesh V.

    2016-11-01

    In this paper, the dynamic crack-interface interactions and the related mechanics of crack penetration vs. branching at a weak interface are studied experimentally. The interface is oriented perpendicular to the incoming mode-I crack in an otherwise homogeneous bilayer. The focus of this investigation is on the effect of interface location and the associated crack-tip parameters within the bilayer on the mechanics of the ensuing fracture behavior based on the optical methodologies laid down in Ref. Sundaram and Tippur (2016). Time-resolved optical measurement of crack-tip deformations, velocity and stress intensity factor histories in different bilayer configurations is performed using Digital Gradient Sensing (DGS) technique in conjunction with high-speed photography. The results show that the crack path selection at the interface and subsequently the second layer are greatly affected by the location of the interface within the geometry. Using optically measured fracture parameters, the mechanics of crack penetration and branching are explained. Counter to the intuition, a dynamically growing mode-I approaching a weak interface at a lower velocity and stress intensity factor penetrates the interface whereas a higher velocity and stress intensity factor counterpart gets trapped by the interface producing branched daughter cracks until they kink out into the next layer. An interesting empirical observation based on measured crack-tip parameters for crack penetration and branching is also made.

  3. Quantifying cerebral blood flow in an adult pig ischemia model by a depth-resolved dynamic contrast-enhanced optical method.

    PubMed

    Elliott, Jonathan T; Diop, Mamadou; Morrison, Laura B; d'Esterre, Christopher D; Lee, Ting-Yim; St Lawrence, Keith

    2014-07-01

    Dynamic contrast-enhanced (DCE) near-infrared (NIR) methods have been proposed for bedside monitoring of cerebral blood flow (CBF). These methods have primarily focused on qualitative approaches since scalp contamination hinders quantification. In this study, we demonstrate that accurate CBF measurements can be obtained by analyzing multi-distance time-resolved DCE data with a combined kinetic deconvolution optical reconstruction (KDOR) method. Multi-distance time-resolved DCE-NIR measurements were made in adult pigs (n=8) during normocapnia, hypocapnia and ischemia. The KDOR method was used to calculate CBF from the DCE-NIR measurements. For validation, CBF was measured independently by CT under each condition. The mean CBF difference between the techniques was -1.7 mL/100 g/min with 95% confidence intervals of -16.3 and 12.9 mL/100 g/min; group regression analysis revealed a strong agreement between the two techniques (slope=1.06±0.08, y-intercept=-4.37±4.33 mL/100 g/min, p<0.001). The results of an error analysis suggest that little a priori information is needed to recover CBF, due to the robustness of the analytical method and the ability of time-resolved NIR to directly characterize the optical properties of the extracerebral tissue (where model mismatch is deleterious). The findings of this study suggest that the DCE-NIR approach presented is a minimally invasive and portable means of determining absolute hemodynamics in neurocritical care patients.

  4. Results of analyses performed on soil adjacent to penetrators emplaced into sediments at McCook, Nebraska, January 1976. [simulated penetration into wind-deposited sediments on Martian plains

    NASA Technical Reports Server (NTRS)

    Blanchard, M.; Bunch, T.; Davis, A.; Kyte, F.; Shade, H.; Erlichman, J.; Polkowski, G.

    1977-01-01

    During 1976 several penetrators (full and 0.58 scale) were dropped into a test site McCook, Nebraska. The McCook site was selected because it simulated penetration into wind-deposited sediments (silts and sands) on Martian plains. The physical and chemical modifications found in the sediment after the penetrators' impact are described. Laboratory analyses have shown mineralogical and elemental changes are produced in the sediment next to the penetrator. Optical microscopy studies of material next to the skin of the penetrator revealed a layer of glassy material about 75 microns thick. Elemental analysis of a 0-1-mm layer of sediment next to the penetrator revealed increased concentrations for Cr, Fe, Ni, Mo, and reduced concentrations for Mg, Al Si, P, K, and Ca. The Cr, Fe, Ni, and Mo were in fragments abraded from the penetrator. Mineralogical changes occurring in the sediment next to the penetrator included the introduction of micron-size grains of alpha iron and several hydrated iron oxide minerals. The newly formed silicate minerals include metastable phases of silica (cristobalite, lechatelierite, and opal). The glassy material was mostly opal which formed when the host minerals (mica, calcite, and clay) decomposed. In summary, contaminants introduced by the penetrator occur up to 2 mm away from the penetrator's skin. Although volatile elements do migrate and new minerals are formed during the destruction of host minerals in the sediment, no changes were observed beyond the 2-mm distance. The analyses indicate 0.58-scale penetrators do effectively simulate full-scale testing for soil modification effects.

  5. Use of the star sign to diagnose internal fistulas in pediatric patients with penetrating Crohn disease by MR enterography.

    PubMed

    Braithwaite, Kiery A; Alazraki, Adina L

    2014-08-01

    Development of internal fistula due to extramural spread of inflammatory bowel disease is a characteristic feature of penetrating disease in patients with Crohn disease. The "star sign" is a radiological finding of internal fistula that has previously been described in the gastroenterology literature in adult Crohn disease patients undergoing MR enteroclysis. The goal of this paper is to review the clinical and imaging features of penetrating disease in pediatric Crohn disease patients, highlighting the star sign as a useful diagnostic tool for diagnosing internal fistula in children by MR enterography. The recognition of penetrating complications by MR imaging can have important therapeutic and prognostic implications.

  6. Penetrating eye globe injury from trauma with a metallic nail: a case report.

    PubMed

    Almodóvar-Mercado, Juan C; López-Beauchamp, Vanessa

    2013-01-01

    We report a case of penetrating eye globe injury due to a metallic nail. This is the first case evaluated by our service that presented with an intact 2.5-centimeter nail penetrating the right eye with a significant intraocular component that the patient did not remove. We describe the initial presentation and the multi-step surgery that this complicated injury required. The early postoperative visual acuity remained unchanged when compared to the presenting. In addition, the patient had no retinal pathology or optic nerve damage after the procedure.

  7. Study on reflection of human skin with liquid paraffin as the penetration enhancer by spectroscopy.

    PubMed

    Chen, Kun; Liang, Yanmei; Zhang, Yuan

    2013-10-01

    Optical clearing agents can improve tissue optical transmittance by reducing the diffuse reflection. The reflection on in vivo human skin before and after applying anhydrous glycerol and 30 to 50% liquid paraffin glycerol mixed solution are investigated in this paper. From their visible and near-infrared reflection spectroscopy, all of their diffuse reflections are reduced after applying the agents. It is found that the three mixed solutions show stronger effect than that of anhydrous glycerol. These results further prove liquid paraffin can enhance the percutaneous penetration of glycerol and take synergistically optical clearing effect with glycerol over visible and near-infrared wave bands.

  8. Detectability of penetration depth based on weld pool geometry and process emission spectrum in laser welding of copper

    NASA Astrophysics Data System (ADS)

    Özmert, Alp; Neisser-Deiters, Paul; Drenker, Alexander

    2014-05-01

    Laser welding is a promising joining process for copper interconnections. A key criterion of quality for these welds is the penetration depth. The penetration depth is subject to intrinsic variation, i.e. by the nature of the welding process. Online detection of penetration depth enables quality assurance and furthermore welding of joint configurations with tighter tolerances via closed-loop control. Weld pool geometry and keyhole optical emission in the wavelength interval of 400-1100 nm are investigated with regard to how suitable they are for the detection of penetration depth in laser welding of copper Cu-ETP. Different penetration depths were induced by stepwise modulation of laser power in bead-on-plate welds. The welds have been monitored with illuminated high-speed videography of the work piece surface and spectrometry. Increase of the weld pool length (in direction of travel) corresponding to increase in penetration depth has been observed while no noticeable change was observed of the weld pool width (transverse to the direction of travel). No significant lines were observed in the spectrum. The radiant power in VIS-spectrum was observed to increase with increasing penetration depth as well. As future work, with increasing understanding and experimental data, online monitoring by indirectly measuring the penetration depth would be possible. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 260153 (QCOALA: Quality Control for Aluminium Laser-Welded Assemblies).

  9. Dopant penetration studies through Hf silicate

    NASA Astrophysics Data System (ADS)

    Quevedo-Lopez, M. A.; Visokay, M. R.; Chambers, J. J.; Bevan, M. J.; LiFatou, A.; Colombo, L.; Kim, M. J.; Gnade, B. E.; Wallace, R. M.

    2005-02-01

    We present a study of the penetration of B, P, and As through Hf silicate (HfSixOy) and the effect of N incorporation in Hf silicate (HfSixOyNz) on dopant penetration from doped polycrystalline silicon capping layers. The extent of penetration through Hf silicate was found to be dependent upon the thermal annealing budget for each dopant investigated as follows: B(T⩾950°C/60s), P(T⩾1000°C/20s), and As (T⩾1050°C/60s). We propose that the enhanced diffusion observed for these dopants in HfSixOy, compared with that of SiO2 films, is related to grain boundary formation resulting from HfSixOy film crystallization. We also find that, as in the case of SiO2, N incorporation inhibits dopant (B, P, and As) diffusion through the Hf silicate and thus penetration into the underlying Si substrate. Only B penetration is clearly observed through HfSiON films for anneals at 1050 °C for durations of 10 s or longer. The calculated B diffusivity through the HfSixOyNz layer is D0=5.2×10-15cm2/s.

  10. Dose-Dependent Protective Effect of Lithium Chloride on Retinal Ganglion Cells Is Interrelated with an Upregulated Intraretinal BDNF after Optic Nerve Transection in Adult Rats

    PubMed Central

    Wu, Ming-Mei; Zhu, Ting-Ting; Wang, Peng; Kuang, Fang; Hao, Ding-Jun; You, Si-Wei; Li, Yao-Yu

    2014-01-01

    Neuroprotection of lithium for axotomized retinal ganglion cells (RGCs) is attributed to upregulated intraretinal Bcl-2. As lithium also upregulates brain-derived neurotrophic factor (BDNF) which can rescue axotomized RGCs, it is hypothesized that lithium could protect RGCs through BDNF. This study investigated this hypothesis and a possible relationship between the dose and protection of lithium. All adult experimental rats received daily intraperitoneal injections of lithium chloride (LiCl) at 30, 60 or 85 mg/kg·bw until they were euthanized 2, 7 or 14 days after left intraorbital optic nerve (ON) transection. Our results revealed that RGC densities promoted and declined with increased dose of LiCl and the highest RGC densities were always in the 60 mg/kg·bw LiCl group at both 7 and 14 day points. Similar promotion and decline in the mRNA and protein levels of intraretinal BDNF were also found at the 14 day point, while such BDNF levels increased in the 30 mg/kg·bw LiCl group but peaked in the 60 and 85 mg/kg·bw LiCl groups at the 7 day point. These findings suggested that lithium can delay the death of axotomized RGCs in a dose-dependent manner within a certain period after ON injury and such beneficial effect is interrelated with an upregulated level of intraretinal BDNF. PMID:25100168

  11. Odd-skipped labels a group of distinct neurons associated with the mushroom body and optic lobe in the adult Drosophila brain

    PubMed Central

    Levy, Peter; Larsen, Camilla

    2013-01-01

    Olfactory processing has been intensively studied in Drosophila melanogaster. However, we still know little about the descending neural pathways from the higher order processing centers and how these connect with other neural circuits. Here we describe, in detail, the adult projections patterns that arise from a cluster of 78 neurons, defined by the expression of the Odd-skipped transcription factor. We term these neurons Odd neurons. By using expression of genetically encoded axonal and dendritic markers, we show that a subset of the Odd neurons projects dendrites into the calyx of the mushroom body (MB) and axons into the inferior protocerebrum. We exclude the possibility that the Odd neurons are part of the well-known Kenyon cells whose projections form the MB and conclude that the Odd neurons belong to a previously not described class of extrinsic MB neurons. In addition, three of the Odd neurons project into the lobula plate of the optic lobe, and two of these cells extend axons ipsi- and contralaterally in the brain. Anatomically, these cells do not resemble any previously described lobula plate tangential cells (LPTCs) in Drosophila. We show that the Odd neurons are predominantly cholinergic but also include a small number of γ-aminobutyric acid (GABA)ergic neurons. Finally, we provide evidence that the Odd neurons are a hemilineage, suggesting they are born from a defined set of neuroblasts. Our anatomical analysis hints at the possibility that subgroups of Odd neurons could be involved in olfactory and visual processing. PMID:23749685

  12. A high-density EEG study of differences between three high speeds of simulated forward motion from optic flow in adult participants

    PubMed Central

    Vilhelmsen, Kenneth; van der Weel, F. R. (Ruud); van der Meer, Audrey L. H.

    2015-01-01

    A high-density EEG study was conducted to investigate evoked and oscillatory brain activity in response to high speeds of simulated forward motion. Participants were shown an optic flow pattern consisting of a virtual road with moving poles at either side of it, simulating structured forward motion at different driving speeds (25, 50, and 75 km/h) with a static control condition between each motion condition. Significant differences in N2 latencies and peak amplitudes between the three speeds of visual motion were found in parietal channels of interest P3 and P4. As motion speed increased, peak latency increased while peak amplitude decreased which might indicate that higher driving speeds are perceived as more demanding resulting in longer latencies, and as fewer neurons in the motion sensitive areas of the adult brain appear to be attuned to such high visual speeds this could explain the observed inverse relationship between speed and amplitude. In addition, significant differences between alpha de-synchronizations for forward motion and alpha synchronizations in the static condition were found in the parietal midline (PM) source. It was suggested that the alpha de-synchronizations reflect an activated state related to the visual processing of simulated forward motion, whereas the alpha synchronizations in response to the static condition reflect a deactivated resting period. PMID:26578903

  13. Penetrators (penetrating sondes) and new possibilities for study of the planets

    NASA Technical Reports Server (NTRS)

    Davydov, V. D.; Skuridin, G. A.

    1979-01-01

    The fields of possible use of penetrators in space research are considered. A survey of the condition of development and plans for use of penetrators abroad is presented and an analysis is given of the significance of scientific problems when probing planets.

  14. Normative Data for Vascular Density in Superficial and Deep Capillary Plexuses of Healthy Adults Assessed by Optical Coherence Tomography Angiography.

    PubMed

    Coscas, Florence; Sellam, Alexandre; Glacet-Bernard, Agnès; Jung, Camille; Goudot, Mathilde; Miere, Alexandra; Souied, Eric H

    2016-07-01

    To establish a normative database for vascular density (VD) and foveal avascular zone (FAZ) at the superficial (SCP) and deep capillary plexus (DCP) in healthy subjects with optical coherence tomography (OCT) angiography. The study was a retrospective chart review of healthy patients who had undergone OCT angiography imaging. A 3- × 3-mm area, centered on the fovea, was scanned for all the study eyes. The automated segmentation allowed separate analysis of the SCP, the DCP, and a comprehensive C-scan including both vascular layers. On the obtained images, VD and FAZ measurements were computed. Interobserver reproducibility and intraobserver repeatability were also assessed. A total of 135 eyes of 70 subjects (51% male) were analyzed. The mean age was 48.3 ± 17.5. We divided patients into group 1, from 20 to 39 years of age; group 2, from 40 to 59 years; and group 3, age 60 years or older. At the level of the SCP, mean VD and mean FAZ ± SD were, respectively, 52.58 ± 3.22% and 0.28 ± 0.1 mm2. At the level of the DCP, mean VD and mean FAZ were 57.87 ± 2.82% and 0.37 ± 0.12 mm2, respectively. The mean VD was significantly higher (P < 0.05) in DCP compared with SCP in all Early Treatment Diabetic Retinopathy Study (ETDRS) sectors and in all age groups. Vascular density was higher in women than in men after 60 years (P < 0.01). After adjustment on the signal strength index (SSI), the mean VD remained directly correlated with the age range and sex. The mean FAZ area was lower in group 3 (P < 0.05). Interobserver reproducibility was 0.78 to 0.99 in SCP and 0.67 to 0.92 in DCP, and intraobserver repeatability was 0.64 to 0.93 in SCP and 0.63 to 0.87 in DCP. Our study has provided, for the first time, age-related VD mapping data using OCT angiography in healthy subjects. The prototype software used in this study may help to improve the concept of VD grading with high inter- and intraexaminer repeatability and interexaminer reproducibility.

  15. Sunshot Initiative High Penetration Solar Portal

    DOE Data Explorer

    The DOE SunShot Initiative is a collaborative national initiative to make solar energy cost-competitive with other forms of energy by the end of the decade. Reducing the installed cost of solar energy systems by about 75% will drive widespread large-scale adoption of this renewable energy and restore U.S. leadership in the global clean energy race. The High Penetration Solar Portal was created as a resource to aggregate the most relevant and timely information related to high penetration solar scenarios and integrating solar into the grid. The site is designed so that utilities, grant awardees, regulators, researchers, and other solar professionals can easily share data, case studies, lessons learned, and demonstration project findings. [from https://solarhighpen.energy.gov/about_the_high_penetration_solar_portal

  16. METHOD AND APPARATUS FOR EARTH PENETRATION

    DOEpatents

    Adams, W.M.

    1963-12-24

    A nuclear reactor apparatus for penetrating into the earth's crust is described. The apparatus comprises a cylindrical nuclear core operating at a temperature that is higher than the melting temperature of rock. A high-density ballast member is coupled to the nuclear core such that the overall density of the core-ballast assembly is greater than the density of molten rock. The nuclear core is thermally insulated so that its heat output is constrained to flow axially, with radial heat flow being minimized. In operation, the apparatus is placed in contact with the earth's crust at the point desired to be penetrated. The heat output of the reactor melts the underlying rock, and the apparatus sinks through the resulting magma. The fuel loading of the reactor core determines the ultimate depth of crust penetration. (AEC)

  17. Penetrating power of resonant electromagnetic induction imaging

    NASA Astrophysics Data System (ADS)

    Guilizzoni, Roberta; Watson, Joseph C.; Bartlett, Paul; Renzoni, Ferruccio

    2016-09-01

    The possibility of revealing the presence and identifying the nature of conductive targets is of central interest in many fields, including security, medicine, industry, archaeology and geophysics. In many applications, these targets are shielded by external materials and thus cannot be directly accessed. Hence, interrogation techniques are required that allow penetration through the shielding materials, in order for the target to be identified. Electromagnetic interrogation techniques represent a powerful solution to this challenge, as they enable penetration through conductive shields. In this work, we demonstrate the power of resonant electromagnetic induction imaging to penetrate through metallic shields (1.5-mm-thick) and image targets (having conductivities σ ranging from 0.54 to 59.77 MSm-1) concealed behind them.

  18. Approach for estimating soil attachment during penetration events

    SciTech Connect

    McNeill, R.L.

    1981-08-01

    It is not presently known if significant soil attachment occurs during a penetration event. If attachment occurs, the penetrator may thereby experience increased decelerating forces and the design loads on the penetrator body may be different from the nonattached case. A method is developed to identify when attachment may occur and to estimate the resulting loads on the penetrator. The important parameters are the weight and dimensions of the penetrator, the velocity of the penetrator, and the stiffness of the soil. The method is intended to guide the design of definitive experiments to identify if attachment occurs and to assess the significance of attachment to the design of penetrators.

  19. Defining success in infant penetrating keratoplasty for developmental corneal opacities.

    PubMed

    Medsinge, Anagha; Speedwell, Lynne; Nischal, Ken K

    2014-01-01

    Neonatal corneal opacities (NCO) are one of the common causes of visual impairment in infants. We present the two infants with penetrating keratoplasty (PKP) for unilateral NCO with different visual and graft outcomes, and illustrate the importance of timing of surgery, importance of visual rehabilitation, and the lack of necessity of a clear graft to achieve reasonable visual function in infants with NCO. Two infants with unilateral NCO (Peters anomaly) underwent PKP at age of 5.5 weeks (Case One) and 16 weeks (Case Two). Postoperative optical correction, amblyopia therapy, visual and graft outcomes were recorded. At the last follow-up (9.5 years in both the cases), Case One achieved a best-corrected visual acuity (BCVA) of 20/80 with -22 D of contact lens. The graft had a small clear zone centrally but otherwise was opacified to some extent. Case Two achieved a BCVA of 20/125 at 30 cms eccentrically with a clear graft. Case Two was uncooperative for amblyopia therapy and optical treatment. For a successful visual outcome in NCO, early PKP, aggressive amblyopia therapy, optical correction, and commitment from the parents for longterm follow-up and demanding treatment are required. © 2014 Board of regents of the University of Wisconsin System, American Orthoptic Journal, Volume 64, 2014, ISSN 0065-955X, E-ISSN 1553-4448.

  20. The effect of welding parameters on penetration in GTA welds

    SciTech Connect

    Shirali, A.A. ); Mills, K.C. )

    1993-07-01

    The effect of various welding parameters on the penetration of GTA welds has been investigated. Increases in welding speed were found to reduce penetration; however, increases in welding current were observed to increase the penetration in high sulfur (HS) casts and decrease penetration in low sulfur (LS) steels. Plots of penetration as a function of increasing linear energy (the heat supplied per unit length of weld) revealed a similar trend with increased penetration in HS casts, but the penetration in LS casts was unaffected by increases in linear energy. These results support the Burgardt-Heiple proposition that changes in welding parameters on penetration can be explained in terms of their effect, sequentially, on the temperature gradient and the Marangoni forces operating in the weld pool. Increases in arc length were found to decrease weld penetration regardless of the sulfur concentration of the steel, and the effects of electrode geometry and welding position on weld penetration were also investigated.

  1. Corneal Penetrating Elastin-Like Polypeptide Carriers

    PubMed Central

    George, Eric M.; Mahdi, Fakhri; Logue, Omar C.; Robinson, Grant G.

    2016-01-01

    Abstract Purpose: Elastin-like polypeptide (ELP) is a bioengineered protein widely applied as a drug carrier due to its biocompatibility and amenability to modification with cell-penetrating peptides (CPPs) and therapeutic agents. The purpose of this study was to determine whether topically applied ELP or CPP-fused ELPs penetrate the corneal barrier. Methods: In vitro binding and cytotoxicity to human corneal epithelial (HCE) cells were determined for ELP or CPP-ELPs. Corneal binding, clearance, and penetration were assessed in a rabbit model following topical application of the fluorescently labeled proteins by quantitative fluorescence imaging and histology. Results: ELP bound to HCE cells in vitro, and binding/uptake was enhanced 2- to 3-fold by the addition of CPPs. When applied topically to rabbit eyes, ELP accumulated in the cornea at levels 7.4-fold higher than did an equivalent dose of immunoglobulin G. Both ELP and a CPP-ELP penetrated the corneal epithelium and were detectable in the stroma. Addition of CPPs to ELP, however, did not significantly enhance corneal uptake or penetration in vivo relative to ELP alone. The polypeptides cleared from the cornea over a period of 20–30 min after application, after which cornea levels reached a steady state of 15–30 μg/mL for up to 3 h. Conclusions: The ELP drug carrier can penetrate the corneal epithelium and accumulate in the stroma. Given its amenability for fusion to multiple types of therapeutic agents, ELP has the potential to serve as a drug carrier for topical ocular applications. PMID:26672799

  2. Failure and penetration response of borosilicate glass during short-rod impact

    SciTech Connect

    Anderson, C. E. Jr.; Orphal, D. L.; Behner, Th.; Hohler, V.; Wickert, M.; Templeton, D. W.

    2007-12-12

    The failure characterization of brittle materials like glass is of fundamental importance in describing the penetration resistance against projectiles. A critical question is whether this failure front remains 'steady' after the driving stress is removed. A test series with short gold rods (D = 1 mm, L/D{approx_equal}5-11) impacting borosilicate glass at {approx}1 to 2 km/s was carried out to investigate this question. The reverse ballistic method was used for the experiments, and the impact and penetration process was observed simultaneously with five flash X-rays and a 16-frame high-speed optical camera. Very high measurement accuracy was established to ensure reliable results. Results show that the failure front induced by rod impact and penetration does arrest (ceases to propagate) after the rod is totally eroded inside the glass. The impact of a second rod after a short time delay reinitiates the failure front at about the same speed.

  3. Modulation of the penetration depth of Nb and NbN films by quasiparticle injection

    NASA Astrophysics Data System (ADS)

    Track, E. K.; Radparvar, M.; Faris, S. M.

    1989-03-01

    A novel approach to modulating the inductance of a superconducting microstrip is described. This approach could be the basis for numerous practical applications, such as phase-shifters and high-frequency tuning elements. The physical mechanisms involved are quasiparticle injection, gap suppression, and penetration-depth modulation. The authors have investigated the modulation of the penetration depth of niobium and niobium nitride films by excess quasiparticle injection. To this effect, all niobium and all-niobium-nitride SQUID (superconducting quantum interference device) circuits were designed and fabricated. These circuits allow quasiparticle injection into the inductive element of the SQUID. This injection is achieved by optical irradiation through an opening in a Nb reflective layer which partially masks the rest of the circuit or electronic current injection through a tunnel junction overlaid on the microstrip inductance. Penetration-depth modulation is achieved with both methods. The magnitude of the effect varies from 10 percent to over 200 percent change in inductance.

  4. Explosive shaped charge penetration into tuff rock

    SciTech Connect

    Vigil, M.G.

    1988-10-01

    Analysis and data for the use of Explosive Shaped Charges (ESC) to generate holes in tuff rock formation is presented. The ESCs evaluated include Conical Shaped Charges (CSC) and Explosive Formed Projectiles (EFP). The CSCs vary in size from 0.158 to 9.1 inches inside cone diameter. The EFPs were 5.0 inches in diameter. Data for projectile impact angles of 30 and 90 degrees are presented. Analytically predicted depth of penetration data generally compared favorably with experimental data. Predicted depth of penetration versus ESC standoff data and hole profile dimensions in tuff are also presented. 24 refs., 45 figs., 6 tabs.

  5. Data penetration transmission in P2P

    NASA Astrophysics Data System (ADS)

    Zheng, Shiping; Feng, Xuezhi

    2007-06-01

    This paper analyzed the type of work principles of the NAT server, and by using UDP Hole Punching and port speculation technology, a program was designed to penetrate the NAT server and direct communication among the intranet users was achieved. This paper also evaluated the communications among users in various types of NAT servers, and it showed a success rate of 95%. By analyzing the principles and setting rules of firewall, together with the application of HTTP tunnel, the designed procedures have penetrated the firewall to visite the user without lowering the security level of the system. The eventual establishment of communication modules facilitated the direct peer-to-peer GIS data transmission.

  6. FREEFALL: A seabed penetrator flight code

    SciTech Connect

    Hickerson, J.

    1988-01-01

    This report presents a one-dimensional model and computer program for predicting the motion of seabed penetrators. The program calculates the acceleration, velocity, and depth of a penetrator as a function of time from the moment of launch until the vehicle comes to rest in the sediment. The code is written in Pascal language for use on a small personal computer. Results are presented as printed tables and graphs. A comparison with experimental data is given which indicates that the accuracy of the code is perhaps as good as current techniques for measuring vehicle performance. 31 refs., 12 figs., 5 tabs.

  7. Mechanics of Penetration: Analysis and Experiment

    DTIC Science & Technology

    1979-02-01

    essentially a 6 MeV x - ray source capable of shining through six inches of steel. It is invaluable for penetration studies since for the first time...data obtained with standard 150-300 KeV x - ray facilities.) Figures 7 and 8 show EPIC3 results for the same situation and Figure 9 depicts results for...for penetration and ricochet have been reviewed by ■p 03 CD CD ■P CO c ■H Xi H bO ■H •H u ■p co o oi X o 0) •p bo B E2 0) 3

  8. HMO penetration: has it hurt public hospitals?

    PubMed

    Clement, J P; Grazier, K L

    2001-01-01

    The purpose of this study is to determine the extent to which health maintenance organization (HMO) penetration within the public hospitals' market area affects the financial performance and viability of these institutions, relative to private hospitals. Hospital- and market-specific measures are examined in a fully interacted model of over 2,300 hospitals in 321 metropolitan statistical areas (MSAs) in 1995. Although hospitals located in markets with higher HMO penetration have lower financial performance as reflected in revenues, expenses and operating margin, public hospitals are not more disadvantaged than other hospitals by managed care.

  9. Corrosion Penetration in Crevices of Dental Amalgam.

    DTIC Science & Technology

    1978-09-07

    AD-AC59 301 LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CALIF PA-ETC F/6 A/S .9 CORROSION PENETRATION IN CREVICES OF DENTAL AMALGAM. (U) SEP 78 T...OF RE;-ORT & PERIOD COVERED ./CORROSION PENETRATION IN CREVICES OF _. Itm . / DENTAL AMALGAM, - . .... ,,, T 7 AUTHOR(s) / L S i DG3t1 , T. Katan and...identify by block number) amalgam corrosion, crevice corrosion, dental amalgam. 20.- ABSTRACT (Continue on reverse side If necessary and Identify by

  10. Penetrating eye injury from a metal wedge.

    PubMed

    Kozielec, G F; To, K

    1999-01-01

    The authors describe a patient with a penetrating ocular injury from a metal wedge, a common hand tool used by road service technicians for the purpose of opening a locked car door. The patient had a penetrating eye injury from a metal wedge when its sharp end released from a car door lock and retracted upward, striking the right eye. No report exists of ocular injury using a metal wedge for its intended purpose of opening a car door lock. The use of polycarbonate lenses might afford some protection.

  11. Dosimetry for lasers and light in dermatology: Monte Carlo simulations of 577 nm-pulsed laser penetration into cutaneous vessels

    NASA Astrophysics Data System (ADS)

    Jacques, Steven L.; Keijzer, Marleen

    1991-06-01

    The role of skin optics in planning proper dosimetry for radiant energy delivered by lasers and conventional light sources is presented. The optical properties of the epidermis, dermis, and cutaneous blood are summarized. The ability of laser pulses at 577-nm wavelength to penetrate into and around a large blood vessel is studied using Monte Carlo simulations. The variation in laser penetration for variable beam diameters and variable vessel depths in presented. The distinction between TOTAL PULSE ENERGY versus PULSE ENERGY DENSITY is illustrated. The topic of this paper is especially pertinent to laser therapy for portwine stain lesions.

  12. Single And Multiple Jet Penetration Experiments Into Geologic Materials

    SciTech Connect

    Kuklo, R; Murphy, M J; Rambur, T A; Switzer, L L; Summers, M A

    2003-12-19

    This paper presents the results of experiments that investigate the effect of single and multiple jet penetration into geologic materials. In previous studies of jet penetration into concrete targets, we demonstrated that an enhanced surface crater could be created by the simultaneous penetration of multiple shaped charge jets and that an enhanced target borehole could be created by the subsequent delayed penetration of a single shaped charge jet. This paper describes an extension of the multiple jet penetration research to limestone and granite.

  13. Penetration of UV Radiation in the Earth's Oceans

    NASA Technical Reports Server (NTRS)

    Mitchell, B. Greg; Lubin, Dan

    2005-01-01

    This project was a collaboration between SIO/UCSD and NASA/GSFC to develop a global estimation of the penetration of UV light into open ocean waters, and into coastal waters. We determined the ocean UV reflectance spectra seen by satellites above the atmosphere by combining existing sophisticated radiative transfer models with in situ UV Visible data sets to improve coupled radiance estimates both underwater and within the atmosphere. Results included improved estimates of surface spectral irradiance, 0.3-1.0 micron, and estimates of photosynthetic inhibition, DNA mutation, and CO production. Data sets developed under this proposal have been made publicly available via submission to the SeaWiFS Bio-Optical Archive and Storage System. Numerous peer-reviewed publications and conference proceedings and abstracts resulted from the work supported by this research award.

  14. Sub-microsecond vapor plume dynamics under different keyhole penetration regimes in deep penetration laser welding

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Pang, Shengyong; Shao, Xinyu; Wang, Chunming; Zhang, Xiaosi; Jiang, Ping; Xiao, Jianzhong

    2017-05-01

    It is well-known that distinct vapor plume dynamics occur during deep penetration laser welding under different keyhole penetration states. However, there is little knowledge about the physical characteristics of vapor plumes (velocity, pressure, flow patterns, etc) located inside transient keyholes of varying penetration regimes in laser welding. This lack of knowledge is primarily because mesoscale vapor plumes are highly dynamic and generally invisible. Based on a well-tested three-dimensional multiphase laser welding model, we conducted a computational study on vapor plume dynamics inside transient keyholes during the fiber laser welding of 304 austenite stainless steel as a function of keyhole penetration regimes. We observed three keyhole regimes of penetration: full penetration, partial penetration and no penetration. We then physically analyzed the vapor plumes in these regimes. We determined that the vapor plume velocities and pressures in all three regimes were uneven and oscillated following the dynamic keyhole with a characteristic timescale in sub-microseconds. Only when the keyhole approached the full penetration regime did vapor plumes begin to violently eject from the bottom of the keyhole opening, whereas in the partial penetration regime, even when the bottom part of the keyhole was open, most of the vapor plume ejected from the upper keyhole opening. This latter observation was similar to that in the no penetration mode. We studied the physical mechanism of this behavior by analyzing the keyhole temperature and vapor plume velocity distributions. We determined that the upward ejection of the vapor plume from the upper keyhole opening was the result of an uneven micro-meter scale boiling phenomenon of the transient keyhole governed by Fresnel absorptions dependent on the local inclination angle of the keyhole wall. Similarly, we determined that the ejection of the vapor plume from the bottom of the keyhole opening resulted from pressure

  15. Trans-eyebrow supraorbital approach in large suprasellar craniopharyngioma surgery in adults: analysis of optic nerve length and extent of tumor resection. Original article.

    PubMed

    Prat, Ricardo; Galeano, Inma; Evangelista, Rocío; Pancucci, Giovanni; Guarín, Juliana; Ayuso, Angel; Misra, Mukesh

    2017-05-01

    One of the main drawbacks in the surgery of large craniopharyngiomas is the presence of a prefixed optic chiasm. Our main objective in this study is to compare the predictive value of the optic nerve length and optic chiasm location on large craniopharyngiomas' extent of resection. We retrospectively studied 21 consecutive patients with large craniopharyngiomas who underwent tumor resection through the trans-eyebrow supraorbital approach. Clinical and radiological findings on preoperative MRI were recorded, including the optic chiasm location classified as prefixed, postfixed or normal. We registered the optic nerve length measured intraoperatively prior to tumor removal and confirmed the measurements on preoperative MRI. Using a linear regression model, we calculated a prediction formula of the percentage of the extent of resection as a function of optic nerve length. On preoperative MRI, 15 patients were considered to have an optic chiasm in a normal location, 3 cases had a prefixed chiasm, and the remaining 3 had a postfixed chiasm. In the group with normal optic chiasm location, a wide range of percentage of extent of resection was observed (75-100%). The percentage of extent of resection of large craniopharyngiomas was observed to be dependent on the optic nerve length in a linear regression model (p < 0.0001). According to this model in the normal optic chiasm location group, we obtained an 87% resection in 9-mm optic nerve length patients, a 90.5% resection in 10-mm optic nerve length patients and 100% resection in 11-mm optic nerve length patients. Optic chiasm location provides useful information to predict the percentage of resection in both prefixed and postfixed chiasm patients but not in the normal optic chiasm location group. Optic nerve length was proven to provide a more accurate way to predict the percentage of resection than the optic chiasm location in the normal optic chiasm location group.

  16. An investigation of penetrant techniques for detection of machining-induced surface-breaking cracks on monolithic ceramics

    SciTech Connect

    Forster, G.A.; Ellingson, W.A.

    1996-02-01

    The purpose of this effort was to evaluate penetrant methods for their ability to detect surface-breaking cracks in monolithic ceramic materials with an emphasis on detection of cracks generated by machining. There are two basic penetrant types, visible and fluorescent. The visible penetrant method is usually augmented by powder developers and cracks detected can be seen in visible light. Cracks detected by fluorescent penetrant are visible only under ultraviolet light used with or without a developer. The developer is basically a powder that wicks up penetrant from a crack to make it more observable. Although fluorescent penetrants were recommended in the literature survey conducted early in this effort, visible penetrants and two non-standard techniques, a capillary gaseous diffusion method under development at the institute of Chemical Physics in Moscow, and the {open_quotes}statiflux{close_quotes} method which involves use of electrically charged particles, were also investigated. SiAlON ring specimens (1 in. diameter, 3/4 in. wide) which had been subjected to different thermal-shock cycles were used for these tests. The capillary gaseous diffusion method is based on ammonia; the detector is a specially impregnated paper much like litmus paper. As expected, visible dye penetrants offered no detection sensitivity for tight, surface-breaking cracks in ceramics. Although the non-standard statiflux method showed promise on high-crack-density specimens, it was ineffective on limited-crack-density specimens. The fluorescent penetrant method was superior for surface-breaking crack detection, but successful application of this procedure depends greatly on the skill of the user. Two presently available high-sensitivity fluorescent penetrants were then evaluated for detection of microcracks on Si{sub 3}N{sub 4} and SiC from different suppliers. Although 50X optical magnification may be sufficient for many applications, 200X magnification provides excellent delectability.

  17. Enhancement Of Penetrant-Inspection Images

    NASA Technical Reports Server (NTRS)

    Wilson, Rhonda C.

    1990-01-01

    Proposed computerized video system processes images of fluorescent dyes absorbed in flaws in welds. Video camera, held by operator or by remote manipulator, views weld illuminated by visible white and ultraviolet light. Images of penetrating dye in cracks and voids in weld joint appear on video monitor. Fluorescent features enhanced by software to facilitate identification of true flaws and record important data.

  18. Computed tomographic findings in penetrating peptic ulcer

    SciTech Connect

    Madrazo, B.L.; Halpert, R.D.; Sandler, M.A.; Pearlberg, J.L.

    1984-12-01

    Four cases of peptic ulcer penetrating the head of the pancreas were diagnosed by computed tomography (CT). Findings common to 3 cases included (a) an ulcer crater, (b) a sinus tract, and (c) enlargement of the head of the pancreas. Unlike other modalities, the inherent spatial resolution of CT allows a convenient diagnosis of this important complication of peptic ulcer disease.

  19. Sealing Penetrating Eye Injuries With Photoactivated Bonding

    DTIC Science & Technology

    2010-09-01

    linking in response to treatment with topical riboflavin and long-wavelength ultraviolet radiation (UVA). Investigative ophthalmology & visual science...in warfighters sustaining penetrating eye injuries. Scope: In year 1, the scope was to establish the treatment parameters for sealing amniotic...established safe limits. Major findings: We identified the treatment parameters (amnion patch size, dye concentration, dye staining time and the

  20. On the penetration of fast charged particles.

    PubMed

    Perry, D J

    1988-07-01

    We pursue Yang's multiple scattering analysis and develop a wave description of electron penetration which permits the calculation of spatial distributions under realistic conditions. We give special emphasis to the longitudinal part of the problem and illustrate with sample calculations of particular interest to medical physicists.

  1. Subsurface investigation with ground penetrating radar

    USDA-ARS?s Scientific Manuscript database

    Ground penetrating radar (GPR) data was collected on a small test plot at the OTF/OSU Turfgrass Research & Education Facility in Columbus, Ohio. This test plot was built to USGA standards for a golf course green, with a constructed sand layer just beneath the surface overlying a gravel layer, that i...

  2. Penetration of amalgam constituents into dentine.

    PubMed

    Scholtanus, Johannes D; Ozcan, Mutlu; Huysmans, Marie-Charlotte D N J M

    2009-05-01

    Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. It is questioned whether penetration of metals into dentine affects the dentine as a substrate for adhesive procedures. This study has been performed to clarify the origin of dark discoloration of dentine by metals from amalgam with special regards to corrosion products. A review of the literature has been performed using Medline database. As keywords dentine and amalgam, subsequently combined with penetration, interface, crevice, interaction, corrosion, were used. This was followed up by extensive hand search using reference lists of relevant articles. Data in the literature have been gathered from extracted amalgam filled teeth and from artificially aged amalgam filled teeth. Corrosion studies have been performed in vivo aged teeth as well as in vitro. Sn is the main element, followed by Zn and Cu, that is consistently found in dentine underneath amalgam, as well as in amalgam corrosion products and in marginal seal deposits. Penetration of elements from amalgam has only been observed in discolored and in demineralised dentine. Darkly discolored dentine as found underneath amalgam restorations contains amalgam corrosion products and is demineralised. Therefore it must be considered a different substrate for clinical procedures than sound dentine.

  3. Penetration and haptenation of p-phenylenediamine.

    PubMed

    Pot, Laura M; Scheitza, Simone M; Coenraads, Pieter-Jan; Blömeke, Brunhilde

    2013-04-01

    Although p-phenylenediamine (PPD) has been recognized as an extreme sensitizer for many years, the exact mechanism of sensitization has not been elucidated yet. Penetration and the ability to bind to proteins are the first two hurdles that an allergen has to overcome to be able to sensitize. This review is an overview of studies regarding PPD penetration through skin (analogues) and studies on the amino acids that are targeted by PPD. To complete this review, the auto-oxidation and N-acetylation steps involved in PPD metabolism are described. In summary, under normal hair dyeing exposure conditions, <1% of the applied PPD dose penetrates the skin. The majority (>80%) of PPD that penetrates will be converted into the detoxification products monoacetyl-PPD and diacetyl-PPD by the N-acetyltransferase enzymes. The small amount of PPD that does not become N-acetylated is susceptible to auto-oxidation reactions, yielding protein-reactive PPD derivatives. These derivatives may bind to specific amino acids, and some of the formed adducts might be the complexes responsible for sensitization. However, true in vivo evidence is lacking, and further research to unravel the definite mechanism of sensitization is needed. © 2013 John Wiley & Sons A/S.

  4. Excimer laser mushroom penetrating keratoplasty: new technique.

    PubMed

    Della Valle, Vincenzo; Bonci, Paolo

    2014-01-01

    To evaluate retrospectively the outcomes of 15 consecutive mushroom-shaped penetrating keratoplasties performed by using excimer laser for both the recipient bed and the fresh donor corneas. Fifteen eyes of 14 patients who underwent excimer laser mushroom-shaped penetrating keratoplasty from October 13, 2010, to October 14, 2011, were included in our retrospective study. Eight were men and 6 were women, with a mean age of 31.45 ± 6.52 (range 27-65) years. Eleven (73.3%) had postinfective central deep corneal scar; 4 (26.7%) had severe keratoconus with Descemet opacity. The mean follow-up was 11.9 ± 2.7 months. The mean preoperative best-corrected visual acuity (BCVA) was 0.15 ± 0.16; the postoperative BCVA was 0.69 ± 0.24 after 12 months with a mean refractive astigmatism of 1.8 ± 1.1 D. The mean preoperative endothelial cell count of the donor corneas was 2297.0 ± 189.7 cells/mm²; after 12 months, it was 1906.5 ± 165.8 with a decrease of 17.0%. No intraoperative complications occurred. Our results showed that excimer laser mushroom penetrating keratoplasty is safe. Furthermore, it does not appear to influence the visual outcomes of the penetrating keratoplasty surgery. This technique is useful for those who use an excimer laser.

  5. Sealing Penetrating Eye Injuries Using Photoactivated Bonding

    DTIC Science & Technology

    2011-09-01

    skin requires specialized training to precisely place hair- fine sutures and requires long surgery time. Cyanoacrylate glues can complicate further... cyanoacrylate glues can cause damage upon removal and interfere with subsequent surgery. In Year 2 (Kochever) we established that lacerations in thin... glue was not competitive with PTB for sealing is amnion over penetrating cornea injuries, determined that two potential adverse effects

  6. Scattering from inhomogeneous penetrable bodies of revolution

    NASA Astrophysics Data System (ADS)

    Govind, S.; Wilton, D. R.; Glisson, A. W.

    1984-11-01

    A systematic procedure for studying scattering from inhomogeneous penetrable bodies in which the inhomogeneity is modeled by piecewise homogeneous layers, is presented. The procedure utilizes the block tridiagonal property of the system matrix to simplify the computations and is applied to examples of dielectric bodies of revolution. An extension of the technique permits the solution of a composite missile/plume scattering problem.

  7. Good penetration of moxifloxacin into human abscesses.

    PubMed

    Sauermann, Robert; Karch, Rudolf; Kjellsson, Maria C; Feurstein, Thomas; Püspök, Andreas; Langenberger, Herbert; Böhmdorfer, Michaela; Jäger, Walter; Zeitlinger, Markus

    2012-01-01

    Abscesses are often treated with antibiotics in addition to incision or when incision is unfeasible, but accurate information about antibiotic abscess penetration in humans is missing. This study aimed at evaluating the penetration of moxifloxacin into human abscesses. After administration of a single dose of 400 mg moxifloxacin, drug concentrations were measured in 10 differently located abscesses at incision, and in plasma over 8 h. At incision performed 0.9-4.8 h after administration, moxifloxacin concentrations in abscesses ranged from ≤0.01 to 9.2 mg/l (1.9 ± 3.4 mg/l), indicating pronounced drug accumulation in some abscesses. The degree of abscess penetration could not be explained by covariates like the ratio of surface area to volume or pH of abscesses, or by moxifloxacin plasma concentrations. Concluding, moxifloxacin was detectable in most abscesses and may be a useful antibiotic for this indication. However, antibiotic abscess penetration was highly variable and unpredictable, suggesting surgical abscess incision whenever possible.

  8. Light penetration in the human prostate: a whole prostate clinical study at 763 nm

    NASA Astrophysics Data System (ADS)

    Moore, Caroline M.; Mosse, C. Alexander; Allen, Clare; Payne, Heather; Emberton, Mark; Bown, Stephen G.

    2011-01-01

    Photodynamic therapy (PDT) is being investigated as a treatment for localized prostate cancer. Photodynamic therapy uses a photosensitizing drug which is activated by a specific wavelength of light, in the presence of oxygen. The activated drug reacts with tissue oxygen to produce reactive oxygen species which are responsible for localized tissue necrosis. One of the determinants of the PDT effect is the penetration of light in the prostate. This study assesses the penetration depth of 763 nm light throughout the prostate. Eight men undergoing multiple hollow needle insertion for high dose rate brachytherapy were recruited. 763 nm light, produced by a diode laser, was delivered to the prostate using cylindrically diffusing optical fibers within the plastic needles. Light was detected at different distances from the source, using an isotropic detector within nearby needles. Penetration depth was calculated using the Boltzmann approximation to the diffusion equation. Delivery detector fiber separation was measured on computed tomography. The mean penetration depth was 0.57 cm, but there was within patient variation of a mean factor of 4.3. Further work is ongoing to assess the effect of such variability in light penetration, on the PDT effect.

  9. Assessment of Quantum Dot Penetration into Skin in Different Species Under Different Mechanical Actions

    NASA Astrophysics Data System (ADS)

    Monteiro-Riviere, N. A.; Zhang, L. W.

    Skin penetration is one of the major routes of exposure for nanoparticles to gain access to a biological system. QD nanoparticles have received a great deal of attention due to their fluorescent characteristics and potential use in medical applications. However, little is known about their permeability in skin. This study focuses on three types of quantum dots (QD) with different surface coatings and concentrations on their ability to penetrate skin. QD621 (polyethylene glycol coated, PEG) was studied for 24 h in porcine skin flow-through diffusion cells. QD565 and QD655 coated with carboxylic acid were studied for 8 and 24 h in flow-through diffusion cells with flexed, tape stripped and abraded rat skin to determine if these mechanical actions could perturb the barrier and affect penetration. Confocal microscopy depicted QD621 penetration through the uppermost layers of the stratum corneum (SC) and fluorescence was found in the SC and near hair follicles. QD621 were found in the intercellular lipid layers of the SC by transmission electron microscopy (TEM). QD565 and 655 with flexed and tape-stripped skin did not show penetration; only abraded skin showed penetration in the viable dermal layers. In all QD studies, inductively coupled plasma-optical emission spectroscopy (ICP-OES) analysis for cadmium (Cd) and fluorescence for QD did not detect Cd or fluorescence signal in the perfusate at any time point, concentration or type of QD. These results indicate that porcine skin penetration of QD621 is minimal and limited primarily to the outer SC layers, while QD565 and 655 penetrated into the dermis of abraded skin. The anatomical complexity of skin and species differences should be taken into consideration when selecting an animal model to study nanoparticle absorption/penetration. These findings are of importance to risk assessment for nanoscale materials because it indicates that if skin barrier is altered such as in wounds, scrapes, or dermatitis conditions could

  10. Experimental study on penetration of dental implants into the maxillary sinus in different depths.

    PubMed

    Zhong, Weijian; Chen, Binke; Liang, Xin; Ma, Guowu

    2013-01-01

    The exposing of dental implant into the maxillary sinus combined with membrane perforation might increase risks of implant failure and sinus complications. The purpose of this study was to investigate the effects of the dental implant penetration into the maxillary sinus cavity in different depths on osseointegration and sinus health in a dog model. Sixteen titanium implants were placed in the bilateral maxillary molar areas of eight adult mongrel dogs, which were randomly divided into four groups according to the different penetrating extents of implants into the sinus cavities (group A: 0 mm; group B: 1 mm; group C: 2 mm; group D: 3 mm). The block biopsies were harvested five months after surgery and evaluated by radiographic observation and histological analysis. No signs of inflammatory reactions were observed in any maxillary sinus of the eight dogs. The tips of the implants with penetrating depth of 1 mm and 2 mm were found to be fully covered with newly formed membrane and partially with new bone. The tips of the implants with penetrating depth over 3 mm were exposed in the sinus cavity and showed no membrane or bone coverage. No significant differences were found among groups regarding implant stability, bone-to-implant contact (BIC) and bone area in the implant threads (BA). Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant osseointegration in canine.

  11. Penetrating Neck Trauma: Review of 192 Cases

    PubMed Central

    Mahmoodie, Mohsen; Sanei, Behnam; Moazeni-Bistgani, Mohammad; Namgar, Mohammad

    2012-01-01

    Background The neck region contains a high density of vital organ structures within a relatively small and unprotected anatomic region, making it one of the most vulnerable areas of the body for all types of injuries. Objectives In this article, we studied penetrating neck trauma cases in Alzahra Hospital over a 10-year period. Patients and Methods In this retrospective, descriptive, analytical study, penetrating neck trauma cases admitted to Alzahra Hospital between April 2000 and April 2010 were analyzed for epidemiology, mechanism of trauma, zone of trauma, therapeutic method, injuries to other organs, complications, and mortality. Results Among 192 penetrating neck injuries, the mean age at the time of injury was 25.08 ± 15.02 years. Of these cases, 96.4% occurred in men. The most common mechanisms of trauma was stab wounds (85.93%). In 56.3% of penetrating neck injuries, zone 2 was involved. Neck exploration was positive in 84.4% of cases, and 52.1% of patients underwent surgery. Vascular exploration was the most common cause of surgery (67.2% of patients). The most common surgical intervention was vein ligation (50.8% of cases). In 11.98% of cases, another organ injury occurred simultaneously, and chest injury was the most common coexisting problem (65.2%). Complications were reported in 9.3% of patients, and the need for intubation was the most common complication (5.2% of patients). Mortality rate was 1.5%. Conclusions According to the findings of this study, the most common cause of penetrating neck injuries was stab wounds, and the majority of patients were young men, therefore, preventive measures should be implemented. Because of fatal complications associated with neck injuries, we recommend early neck exploration in unstable cases or when injuries are deeper than the platysma. PMID:24719835

  12. Laryngeal penetration during deglutition in normal subjects of various ages.

    PubMed

    Daggett, Alicia; Logemann, Jeri; Rademaker, Alfred; Pauloski, Barbara

    2006-10-01

    This study examined the frequency of penetration of liquid, paste, and masticated materials into the airway during videofluoroscopic studies of normal swallow in 98 normal subjects who were from 20 to 94 years of age. The purposes of the study were to define frequency and level of penetration using the penetration-aspiration scale as a result of age, bolus volume, viscosity, and gender, and to describe the body's sensorimotor response to the penetration based on audible coughs or throat clearing on the audio channel of each videotaped fluoroscopic study. Frequencies of penetration were defined in relation to bolus volume, age, gender, and bolus viscosity from swallows of 1, 3, 5, and 10 ml and cup-drinking of thin liquids; 3 ml of pudding; (1/4) of a Lorna Doone cookie; and a bite of an apple. Results showed that penetrations were significantly more frequent after age 50 and thick viscosities penetrated only in subjects age 50 and over. For persons under 50, 7.4% of swallows exhibited penetration, while for people age 50 and over, 16.8% of swallows showed penetration. Significantly more penetration occurred on larger liquid boluses. There was no relationship between gender and frequency of penetration. None of the subjects that penetrated showed a sensorimotor response to the penetration, which may relate to the relatively shallow depth of the penetration.

  13. Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen saturation in old and young adults with near-infrared spectroscopy.

    PubMed

    Hallacoglu, Bertan; Sassaroli, Angelo; Wysocki, Michael; Guerrero-Berroa, Elizabeth; Schnaider Beeri, Michal; Haroutunian, Vahram; Shaul, Merav; Rosenberg, Irwin H; Troen, Aron M; Fantini, Sergio

    2012-08-01

    We present near-infrared spectroscopy measurement of absolute cerebral hemoglobin concentration and saturation in a large sample of 36 healthy elderly (mean age, 85 ± 6 years) and 19 young adults (mean age, 28 ± 4 years). Non-invasive measurements were obtained on the forehead using a commercially available multi-distance frequency-domain system and analyzed using a diffusion theory model for a semi-infinite, homogeneous medium with semi-infinite boundary conditions. Our study included repeat measurements, taken five months apart, on 16 elderly volunteers that demonstrate intra-subject reproducibility of the absolute measurements with cross-correlation coefficients of 0.9 for absorption coefficient (μa), oxy-hemoglobin concentration ([HbO2]), and total hemoglobin concentration ([HbT]), 0.7 for deoxy-hemoglobin concentration ([Hb]), 0.8 for hemoglobin oxygen saturation (StO2), and 0.7 for reduced scattering coefficient (μ's). We found significant differences between the two age groups. Compared to young subjects, elderly subjects had lower cerebral [HbO2], [Hb], [HbT], and StO2 by 10 ± 4 μM, 4 ± 3 μM, 14 ± 5 μM, and 6%±5%, respectively. Our results demonstrate the reliability and robustness of multi-distance near-infrared spectroscopy measurements based on a homogeneous model in the human forehead on a large sample of human subjects. Absolute, non-invasive optical measurements on the brain, such as those presented here, can significantly advance the development of NIRS technology as a tool for monitoring resting/basal cerebral perfusion, hemodynamics, oxygenation, and metabolism.

  14. Measurement of microstructure and eutectic penetration rate on irradiated metallic fuel after high-temperature heating test

    NASA Astrophysics Data System (ADS)

    Kim, June-Hyung; Cheon, Jin-Sik; Lee, Byoung-Oon; Kim, Jun-Hwan; Kim, Hee-Moon; Yoo, Boung-Ok; Jung, Yang-Hong; Ahn, Sang-Bok; Lee, Chan-Bock

    2017-05-01

    Microstructural development of irradiated U-10Zr fuel slug with T92 cladding specimen was examined after thermal exposure of 750 °C for 1 h. Optical microscopy, scanning electron microcopy and electron microprobe analysis were employed to examine the microstructure, constituent migration, and eutectic penetration. Migration phenomena of U, Zr, Fe, and Cr indicative of Soret effect was observed, and Nd lanthanide fission product was found at the eutectic melting region. Eutectic penetration was quantified and correlated to a thermal activation model with a good agreement. Compared to the previously reported eutectic penetration rates for the unirradiated U-10Zr fuel slug with FMS (Ferritic Martensitic Steel, HT9) cladding specimens, the eutectic penetration rate determined from this study for the irradiated fuel specimen was higher. This phenomenon can be caused by the effect of lanthanide fission product migration into fuel slug-cladding interface during irradiation, and lowering the eutectic threshold temperature for the irradiated fuel.

  15. Low penetrance hereditary retinoblastoma in a family: what should we consider in the genetic counselling process and follow up?

    PubMed

    Serrano, C; Alonso, J; Gómez-Mariano, G; Aguirre, E; Diez, O; Gadea, N; Bosch, N; Balmaña, J; Graña, B

    2011-09-01

    Hereditary retinoblastoma (Rb) is a high penetrance autosomal dominant disease showing not only an increased risk of suffering bilateral Rb but also other second neoplasms. However, some families show a low-penetrance phenotype with reduced expressivity and incomplete penetrance of the retinoblastoma gene (RB1). Given the lack of specific guidelines for the follow-up of adult patients with hereditary Rb, the authors present a case report of a family with a low-penetrance phenotype and review the recommended surveillance in this setting, stressing the difficulties found in the genetic counselling process and follow up. Thus, since patients are at an increased risk, lifelong regular medical surveillance to detect any second malignancy at a stage that can be cured is required. In addition, avoidance of DNA-damaging agents and genetic testing should be considered for a throughout management of these families.

  16. Penetrating keratoplasty restoring vision in an unusual case of corneal opacity following exposure to Euphorbia latex.

    PubMed

    Dutta, Jayanta; Choudhury, Somnath; Lahiri, Kapildeb; Savale, Smruti; Banerjee, Monideepa; Datta, Himadri

    2015-10-01

    The milky sap of the Euphorbia plant is highly toxic and causes inflammation to the skin and eyes. Damage to the eye ranges from superficial epithelial defects, keratoconjunctivitis, mild to moderate corneal edema, anterior uveitis, Descemet membrane folds, raised intraocular pressure and rarely corneal opacity in severe untreated cases. Here we report a case of visual restoration by optical penetrating keratoplasty in a patient with severe corneal opacity following exposure to Euphorbia latex.

  17. The penetrating depth analysis of Lunar Penetrating Radar onboard Chang’e-3 rover

    NASA Astrophysics Data System (ADS)

    Xing, Shu-Guo; Su, Yan; Feng, Jian-Qing; Dai, Shun; Xiao, Yuan; Ding, Chun-Yu; Li, Chun-Lai

    2017-04-01

    Lunar Penetrating Radar (LPR) has successfully been used to acquire a large amount of scientific data during its in-situ detection. The analysis of penetrating depth can help to determine whether the target is within the effective detection range and contribute to distinguishing useful echoes from noise. First, this study introduces two traditional methods, both based on a radar transmission equation, to calculate the penetrating depth. The only difference between the two methods is that the first method adopts system calibration parameters given in the calibration report and the second one uses high-voltage-off radar data. However, some prior knowledge and assumptions are needed in the radar equation and the accuracy of assumptions will directly influence the final results. Therefore, a new method termed the Correlation Coefficient Method (CCM) is provided in this study, which is only based on radar data without any a priori assumptions. The CCM can obtain the penetrating depth according to the different correlation between reflected echoes and noise. To be exact, there is a strong correlation in the useful reflected echoes and a random correlation in the noise between adjacent data traces. In addition, this method can acquire a variable penetrating depth along the profile of the rover, but only one single depth value can be obtained from traditional methods. Through a simulation, the CCM has been verified as an effective method to obtain penetration depth. The comparisons and analysis of the calculation results of these three methods are also implemented in this study. Finally, results show that the ultimate penetrating depth of Channel 1 and the estimated penetrating depth of Channel 2 range from 136.9 m to 165.5 m ({\\varepsilon }r=6.6) and from 13.0 m to 17.5 m ({\\varepsilon }r=2.3), respectively.

  18. The contemporary management of penetrating splenic injury.

    PubMed

    Berg, Regan J; Inaba, Kenji; Okoye, Obi; Pasley, Jason; Teixeira, Pedro G; Esparza, Michael; Demetriades, Demetrios

    2014-09-01

    Selective non-operative management (NOM) is standard of care for clinically stable patients with blunt splenic trauma and expectant management approaches are increasingly utilised in penetrating abdominal trauma, including in the setting of solid organ injury. Despite this evolution of clinical practice, little is known about the safety and efficacy of NOM in penetrating splenic injury. Trauma registry and medical record review identified all consecutive patients presenting to LAC+USC Medical Center with penetrating splenic injury between January 2001 and December 2011. Associated injuries, incidence and nature of operative intervention, local and systemic complications and mortality were determined. During the study period, 225 patients experienced penetrating splenic trauma. The majority (187/225, 83%) underwent emergent laparotomy. Thirty-eight clinically stable patients underwent a deliberate trial of NOM and 24/38 (63%) were ultimately managed without laparotomy. Amongst patients failing NOM, 3/14 (21%) underwent splenectomy while an additional 6/14 (42%) had splenorrhaphy. Hollow viscus injury (HVI) occurred in 21% of all patients failing NOM. Forty percent of all NOM patients had diaphragmatic injury (DI). All patients undergoing delayed laparotomy for HVI or a splenic procedure presented symptomatically within 24h of the initial injury. No deaths occurred in patients undergoing NOM. Although the vast majority of penetrating splenic trauma requires urgent operative management, a group of patients does present without haemodynamic instability, peritonitis or radiologic evidence of hollow viscus injury. Management of these patients is complicated as over half may remain clinically stable and can avoid laparotomy, making them potential candidates for a trial of NOM. HVI is responsible for NOM failure in up to a fifth of these cases and typically presents within 24h of injury. Delayed laparotomy, within this limited time period, did not appear to increase

  19. Heterologous ovum penetration by human spermatozoa.

    PubMed

    Tyler, J P; Pryor, J P; Collins, W P

    1981-11-01

    An evaluation of a method utilizing zona-free hamster ova to test the fertility of human spermatozoa has shown that (i) the induction of superovulation in immature animals provides the most convenient method of obtaining mature ova for study; (ii) motile spermatozoa are best prepared by the technique of layering; (iii) an 18 h incubation at 37 degrees C (which is associated with capacitation) in an atmosphere of air (pH of medium 8.2) is preferable to one of 5% CO2 (pH of medium 7.2); (iv) the incubation and insemination densities of spermatozoa should be greater than 1 X 10(6) and less than 10 X 10(6)/ml; (v) spermatozoa do not remain motile, or capable of binding to or penetrating ova, after about 30 h in culture; and (vi) intra- and inter-assay variations are acceptable. The spermatozoa from 15 healthy men of proven fertility and 15 subfertile patients with normal spermiograms were evaluated for their ability to bind to and penetrate zona-free hamster ova. Of the 476 ova inseminated with spermatozoa from the fertile men greater than 5 spermatozoa/ovum consistently bound to the vitelline membrane and 284 ova (59.7%) had swollen sperm heads to pronuclei (still with tails attached) in their ooplasm. The range of individual penetration rates was 23.5-88.9%. Of the 586 ova tested with spermatozoa from the infertile subjects only 11 (1.9%) showed any evidence of penetration (range of individual penetration rates 0-8.7%) and binding to the vitelline membrane was poor (0 or less than 5 spermatozoa/ovum). Spermatozoa from a further 9 infertile men who had abnormal spermiograms also gave poor penetration rates (4/300 ova, 1.3%). It is concluded that this bioassay has a useful role as an additional test to the classic spermiogram, but that its routine use is best reserved for selected cases of unexplained infertility.

  20. Recent progress in tissue optical clearing.

    PubMed

    Zhu, Dan; Larin, Kirill V; Luo, Qingming; Tuchin, Valery V

    2013-09-01

    Tissue optical clearing technique provides a prospective solution for the application of advanced optical methods in life sciences. This paper gives a review of recent developments in tissue optical clearing techniques. The physical, molecular and physiological mechanisms of tissue optical clearing are overviewed and discussed. Various methods for enhancing penetration of optical-clearing agents into tissue, such as physical methods, chemical-penetration enhancers and combination of physical and chemical methods are introduced. Combining the tissue optical clearing technique with advanced microscopy image or labeling technique, applications for 3D microstructure of whole tissues such as brain and central nervous system with unprecedented resolution are demonstrated. Moreover, the difference in diffusion and/or clearing ability of selected agents in healthy versus pathological tissues can provide a highly sensitive indicator of the tissue health/pathology condition. Finally, recent advances in optical clearing of soft or hard tissue for in vivo imaging and phototherapy are introduced. [Formula: see text].

  1. Recent progress in tissue optical clearing

    PubMed Central

    Zhu, Dan; Larin, Kirill V; Luo, Qingming; Tuchin, Valery V

    2013-01-01

    Tissue optical clearing technique provides a prospective solution for the application of advanced optical methods in life sciences. This paper gives a review of recent developments in tissue optical clearing techniques. The physical, molecular and physiological mechanisms of tissue optical clearing are overviewed and discussed. Various methods for enhancing penetration of optical-clearing agents into tissue, such as physical methods, chemical-penetration enhancers and combination of physical and chemical methods are introduced. Combining the tissue optical clearing technique with advanced microscopy image or labeling technique, applications for 3D microstructure of whole tissues such as brain and central nervous system with unprecedented resolution are demonstrated. Moreover, the difference in diffusion and/or clearing ability of selected agents in healthy versus pathological tissues can provide a highly sensitive indicator of the tissue health/pathology condition. Finally, recent advances in optical clearing of soft or hard tissue for in vivo imaging and phototherapy are introduced. PMID:24348874

  2. Penetrating Retrobulbar Orbital Foreign Body: A Transcranial Approach

    PubMed Central

    Chung, In-Young; Han, Yong-Seop; Kim, Eurie; Jung, Jin-Myung

    2007-01-01

    We report the successful removal of a retrobulbar foreign body using a transcranial approach in a 63-year-old patient with a penetrating injury to the left eye. Initial ocular examination revealed a corneoscleral laceration, hyphema, a traumatic cataract, and vitreous hemorrhage. Visual acuity consisted only of the perception of hand motion. Computed tomography demonstrated an orbital foreign body in the retrobulbar area. Emergency corneoscleral suturing, phacoemulsification of the cataract, and vitrectomy with posterior vitreous detachment were performed. Fifteen days after the emergency operation, we successfully removed the orbital foreign body using a transcranial approach, although the foreign body was very close to the optic nerve. On fundus examination 6 months later, a white, fibrous lesion was seen inferior to the optic disc, and the corrected visual acuity was 20/30. These positive results may be due to the complete vitrectomy at the correct time performed by a retina specialist and the minimal pressure on the eyeball while removing the foreign body, which resulted from the use of a transcranial approach. PMID:17461536

  3. Penetration of UV irradiance into the global ocean

    NASA Astrophysics Data System (ADS)

    Smyth, T. J.

    2011-11-01

    A new global ocean-atmosphere model has been developed to determine the penetration of ultraviolet (UV) radiation through the water column. This is accomplished by combining an atmospheric UV irradiance model, taking into consideration the effects of aerosols, clouds, and the air-sea interface, with empirical in-water diffuse attenuation coefficient (Kd(λUV)) relationships. These empirical relationships are derived from simultaneous in situ profiles of visible wavelength inherent optical properties and downwelling UV irradiances. The combined model is applied to global data sets using a look-up table approach to speed up calculation time. The atmospheric model compared against ˜3000 data points gave a root-mean-square error (RMSE) of between 10% and 15% at wavelengths of 305, 325, 340, and 380 nm; the coupled global model compared against 30 independent in-water irradiance profiles gave a logarithmic RMSE of between 0.15 and 0.35 at these wavelengths. On the global scale the 10% irradiance levels were found to be deepest in the oceanic gyres (˜18, 32, 44, and 70 m at 305, 325, 340 and 380 nm, respectively) and shallowest in the optically complex continental shelf regions. The calculated UV doses were shown to be spectrally and seasonally variable, with the highest values being encountered in the eastern Mediterranean during July, with values of ˜0.5, 4, 7, and 10 kJ m-2 d-1 nm-1 at 305, 325, 340, and 380 nm, respectively.

  4. Benchmark field study of deep neutron penetration

    SciTech Connect

    Morgan, J.F.; Sale, K. ); Gold, R.; Roberts, J.H.; Preston, C.C. )

    1991-06-10

    A unique benchmark neutron field has been established at the Lawrence Livermore National Laboratory (LLNL) to study deep penetration neutron transport. At LLNL, a tandem accelerator is used to generate a monoenergetic neutron source that permits investigation of deep neutron penetration under conditions that are virtually ideal to model, namely the transport of mono-energetic neutrons through a single material in a simple geometry. General features of the Lawrence Tandem (LATAN) benchmark field are described with emphasis on neutron source characteristics and room return background. The single material chosen for the first benchmark, LATAN-1, is a steel representative of Light Water Reactor (LWR) Pressure Vessels (PV). Also included is a brief description of the Little Boy replica, a critical reactor assembly designed to mimic the radiation doses from the atomic bomb dropped on Hiroshima, and its us in neutron spectrometry. 18 refs.

  5. [Cell penetrating peptides in cancer therapy].

    PubMed

    Huang, Shao; Liu, Ya-Wei; Jiang, Yong

    2007-10-01

    The genomic information obtained through the human genome project has been accelerating the analysis of the functions of various disease relevant genes. The high molecular weight biomolecules becomes increasingly important for the development of molecular therapies. However, the usage of such therapeutic macromolecules has been limited by the poor permeability across the lipid bilayer of the cellular plasma membrane. In order to overcome this barrier, several chemical and physical methods have been developed, such as electroporation and cationic lipids/liposomes. The drawbacks of these methods are the unwanted cellular effects and their limitation to in vitro applications. Cell penetrating peptides (CPPs) is a group of oligopeptides that could penetrate the cell membrane via a receptor-independent and non-endocytotic process with various conjungated bioactive molecules. Such ability makes them outstanding transmembrane vectors for various therapuetic biomolecules. In this review, we will introduce several representative strategies to develop antitumor macromolecules using CPPs.

  6. Vacuum radiation pressure fluctuations and barrier penetration

    NASA Astrophysics Data System (ADS)

    Huang, Haiyun; Ford, L. H.

    2017-07-01

    We apply recent results on the probability distribution for quantum stress tensor fluctuations to the problem of barrier penetration by quantum particles. The probability for large stress tensor fluctuations decreases relatively slowly with increasing magnitude of the fluctuation, especially when the quantum stress tensor operator has been averaged over a finite time interval. This can lead to large vacuum radiation pressure fluctuations on charged or polarizable particles, which can in turn push the particle over a potential barrier. The rate for this effect depends sensitively upon the details of the time averaging of the stress tensor operator, which might be determined by factors such as the shape of the potential. We make some estimates for the rate of barrier penetration by this mechanism and argue that in some cases this rate can exceed the rate for quantum tunneling through the barrier. The possibility of observation of this effect is discussed.

  7. Penetrating Heart Injury due to Screwdriver Assault

    PubMed Central

    Dieng, P. A.; Diop, M. S.; Ciss, A. G.; Ba, P. S.; Diatta, S.; Gaye, M.; Fall, M. L.; Ndiaye, A.; Ndiaye, M.

    2015-01-01

    Penetrating heart injuries cause wounds in the cardiac chambers. Most of them are due to gunshot or stabbing by knives. Screwdriver is an uncommon weapon. Authors report a case of stab wound by screwdriver, treated at cardiovascular center in Dakar. This is a 16-year-old boy who experienced physical aggression. He was assaulted with a screwdriver and had stab wound on the anterior wall of the chest. Physical examination showed a screwdriver penetrating the sternum bone over a right angle. He had a mild pericardial blood effusion and a right ventricle wound 5 mm in diameter with transection of the right coronary vein. The screwdriver was removed without cardiopulmonary bypass (CPB) and the ventricle wound repaired by direct suture of stitches reinforced with Teflon pledgets. The right coronary artery was ligated. Postoperative period was free of events. Screwdriver is uncommonly used as a weapon. It is a dangerous device because of its rigid structure and narrow tip. PMID:25945263

  8. Passive and iontophoretic transdermal penetration of chlorpromazine.

    PubMed

    Alvarez-Figueroa, María Javiera; González-Aramundiz, José Vicente

    2008-01-01

    The in vitro iontophoretic transdermal delivery of chlorpromazine (CPZ) across pig skin was investigated. Anodal iontophoresis considerably increased CPZ skin penetration and accumulation compared with the passive controls. The effect of CPZ concentration in the donor solution was studied (1.4-8.2 mM). A higher penetration was observed with an increase of the concentration. In addition, the effect of NaCl concentration was also studied (154-200 mM). As expected, CPZ iontophoretic transport decreased with NaCl content. Finally, the influence of the current density (0.20-0.50 mA/cm(2)) was investigated. The iontophoretic transport of CPZ tends to increase with current density, although this effect was not statistically significant between 0.35 and 0.5 mA/cm(2). On the whole, this work shows that iontophoresis may be used to improve the transdermal delivery of CPZ for the treatment of chronic psychosis.

  9. Improved ground-penetrating radar, bridge decks

    SciTech Connect

    Warhus, J.P.; Mast, J.E.; Johansson, E.M.; Nelson, S.D.

    1993-11-29

    Inspection of high-value structures, like bridges and buildings, using Ground Penetrating Radar (GPR) is an application of a technology that is growing in importance. In a typical inspection application, inspectors use GPR to locate structural components, like embedded reinforcing bars, to avoid weakening the structure while collecting core samples for detailed inspection. Advanced GPR, integrated with imaging technologies for use as an NDE tool, can provide the capability to quickly locate and characterize construction flaws and wear- or age-induced damage in these structures without resorting to destructive methods. In this paper, we discuss an important inspection application, namely, concrete bridge deck inspection. We describe an advanced bridge deck inspection system concept (Ground Penetrating Imaging Radar, GPIR) and present results from experiments designed to simulate the concept.

  10. Containment penetration elastomer seal leak rate tests

    SciTech Connect

    Bridges, T.L.

    1987-07-01

    Tests were performed on three elastomer seal designs commonly used for nuclear plant containment mechanical penetrations. The objective of this research project is to obtain an understanding of the integrity and leakage behavior of these seal designs under severe accident temperature and pressure conditions. The three designs tested and the seal materials used in the tests were: (1) double tongue-and-groove design with silicone rubber seals, (2) double-O-ring design with neoprene and ethylene-propylene (EPDM) seals, and (3) double gumdrop design with neoprene and EPDM seals. The effects of thermal aging and angular rotations of flange mating surfaces were determined. The test results provide information required to characterize the leakage behavior of penetrations under severe accident conditions. 3 refs., 10 figs., 12 tabs.

  11. Market penetration of new energy technologies

    SciTech Connect

    Packey, D.J.

    1993-02-01

    This report examines the characteristics, advantages, disadvantages, and, for some, the mathematical formulas of forecasting methods that can be used to forecast the market penetration of renewable energy technologies. Among the methods studied are subjective estimation, market surveys, historical analogy models, cost models, diffusion models, time-series models, and econometric models. Some of these forecasting methods are more effective than others at different developmental stages of new technologies.

  12. A Spatial Display for Ground Penetrating Radar

    DTIC Science & Technology

    2015-04-14

    interfaces present the raw GPR data to an operator in cross sections organized by time and depth. The intent of these displays is to allow a human operator...imagery and generating a mental model required to formulate a plan of action. II. METHODOLOGY The Gopher radar data is captured and analyzed by...1 A Spatial Display for Ground-Penetrating Radar Paul W. Quimby, Member, IEEE, Mary Cummings, Member, IEEE, and Matthew Cornick Abstract---Regardless

  13. Efficient Calculation of Earth Penetrating Projectile Trajectories

    DTIC Science & Technology

    2006-09-01

    seconds and stable trajectories are solved in less than three seconds. 15. NUMBER OF PAGES 119 14 . SUBJECT TERMS Ballistic, Penetration, Simulation...Bottom Half of Weapon from 2 Degree Angle of Attack ............... 14 Figure 9. Moment on Top Half of Weapon from a 2 Degree Angle of Attack... 14 Figure 10. Forces on Bottom Half of Weapon from 2 Degree Angle of Attack ...............15 Figure 11. Additional Areas of Stress Due to

  14. Penetration of Projectiles into Seafloor Soils

    DTIC Science & Technology

    1975-05-01

    data have shown that the assumed to be as given by Equations 10 and 11. A ratio of dynamic to static soi strength, terme the bearing capacity factor of... bearing pressure theory and dynamic (Smith 1971, and Taylor and Beard. 1973) with rea- soil strength can be generalized readily to the shallow sonable... penetrometers and in the utilization of dynamic of free-falling objects into soft seafloor materials. penetration data to evaluate the engineering proper

  15. Engineering and Design: Standard Penetration Test

    DTIC Science & Technology

    2007-11-02

    Penetration TestDe Contract Number Grant Number Program Element Number Author(s) Project Number Task Number Work Unit Number Performing Organization Name...jsfi I I US* of drlXXi~ mucl -r*ueusiog In I Decrm8e8 hcrea8ea Zither Increases Increases Increeses Decrea8es lncreeaes Increases Increeaes Zither &creases DecrU8e* nem8*s hcruses Xnt-ses tieee Utber k~ee Enclosure 2

  16. Market penetration of new energy technologies

    SciTech Connect

    Packey, D.J.

    1993-02-01

    This report examines the characteristics, advantages, disadvantages, and, for some, the mathematical formulas of forecasting methods that can be used to forecast the market penetration of renewable energy technologies. Among the methods studied are subjective estimation, market surveys, historical analogy models, cost models, diffusion models, time-series models, and econometric models. Some of these forecasting methods are more effective than others at different developmental stages of new technologies.

  17. Robust Algorithms for Penetration Mechanics Problems

    DTIC Science & Technology

    1998-02-01

    strain rate and studied a purely mechanical problem. Recht26 has adapted the Taylor27 model of mushrooming to the situation in which the penetrator...for tungsten. However, when either the shear modulus for the tungsten block was artificially changed to that for the uranium block, or the defects ...the intense deformations of the rod in the mushroomed region. Computed results for a trial problem indicated that the height of the mushroomed

  18. Whole-body multispectral photoacoustic imaging of adult zebrafish

    PubMed Central

    Huang, Na; Guo, Heng; Qi, Weizhi; Zhang, Zhiwei; Rong, Jian; Yuan, Zhen; Ge, Wei; Jiang, Huabei; Xi, Lei

    2016-01-01

    The zebrafish, an ideal vertebrate for studying developmental biology and genetics, is increasingly being used to understand human diseases, due to its high similarity to the human genome and its optical transparency during embryonic stages. Once the zebrafish has fully developed, especially wild-type breeds, conventional optical imaging techniques have difficulty in imaging the internal organs and structures with sufficient resolution and penetration depth. Even with established mutant lines that remain transparent throughout their life cycle, it is still challenging for purely optical imaging modalities to visualize the organs of juvenile and adult zebrafish at a micro-scale spatial resolution. In this work, we developed a non-invasive three-dimensional photoacoustic imaging platform with an optimized illumination pattern and a cylindrical-scanning-based data collection system to image entire zebrafish with micro-scale resolutions of 80 μm and 600 μm in the lateral and axial directions, respectively. In addition, we employed a multispectral strategy that utilized excitation wavelengths from 690 nm to 930 nm to statistically quantify the relative optical absorption spectrum of major organs. PMID:27699119

  19. Percutaneous penetration modifiers and formulation effects.

    PubMed

    Kaushik, Diksha; Costache, Aurora; Michniak-Kohn, Bozena

    2010-02-15

    The enhancement/retardation of percutaneous permeation of diethyl-m-toluamide (DEET) in the presence of five percutaneous penetration modifiers (laurocapram, 3-dodecanoyloxazolidin-2-one (N-0915), S,S-dimethyl-N-(4-bromobenzoyl) iminosulfurane (DMBIS), S,S-dimethyl-N-(2-methoxycarbonylbenzenesulfonyl) iminosulfurane (DMMCBI) and tert-butyl 1-dodecyl-2-oxoazepan-3-yl-carbamate (TBDOC)) was investigated. These permeation modifiers were formulated in either water, propylene glycol (PG), ethanol or polyethylene glycol 400 (PEG 400). The permeation studies indicated that laurocapram enhanced DEET permeation in PG, but retarded in PEG 400. Likewise, N-0915 acted as a retardant with ethanol and PEG 400, but not with water. DMBIS decreased the permeation with ethanol as compared to permeation with water, PEG 400 or PG. Similarly, DMMCB acted as a retardant with ethanol and PEG 400, but not with water or PG. TBDOC formulations revealed its activity as a retardant with ethanol, but behaved as enhancer with water, PG and PEG 400. In addition, penetration modifier interactions with stratum corneum ceramide were investigated using chemical modeling. This investigation is significant since it confirms the role of pharmaceutical formulations and shows for the first time that an enhancer can become a retardant or vice versa depending upon the vehicle in which it is applied to the skin. Hence, we should be using the term "penetration modifiers" for all such compounds. Copyright 2009 Elsevier B.V. All rights reserved.

  20. Cooperative penetration in a light granular medium

    NASA Astrophysics Data System (ADS)

    Ruiz-Suarez, J. Carlos; Pacheco-Vazquez, Felipe

    2010-11-01

    A projectile impacting against a granular medium exemplifies the interesting nature of granular matter. Whether the projectile is an asteroid striking the crust of a planet or an object thrown against a granular bed in the laboratory, once the intruder makes contact with the medium it inevitably encounters a stopping force. The character of this force underscore several fundamental issues, from geological and biological sciences, to soil research and technological applications. The impact velocity dependence, the final penetration depth as a function of different parameters, the nature of the drag force, are nowadays well understood thanks to the recent work carried out by different groups. Furthermore, the effects of confinement, object symmetry and fragility of the medium have also been considered. However, despite all this effort, we know very little about what occurs when more than one intruder impact simultaneously a granular medium. Here we show and discuss some experimental findings about the penetration dynamics followed by a group of intruders impacting a granular medium. The particles used in our study are much lighter than water, therefore, intruders penetrate deeply into the system depicting intriguing cooperative behaviours that hint to hydrodynamic-like interactions.

  1. Rifle bullet penetration into ballistic gelatin.

    PubMed

    Wen, Yaoke; Xu, Cheng; Jin, Yongxi; Batra, R C

    2017-03-01

    The penetration of a rifle bullet into a block of ballistic gelatin is experimentally and computationally studied for enhancing our understanding of the damage caused to human soft tissues. The gelatin is modeled as an isotropic and homogeneous elastic-plastic linearly strain-hardening material that obeys a polynomial equation of state. Effects of numerical uncertainties on penetration characteristics are found by repeating simulations with minute variations in the impact speed and the angle of attack. The temporary cavity formed in the gelatin and seen in pictures taken by two high speed cameras is found to compare well with the computed one. The computed time histories of the hydrostatic pressure at points situated 60 mm above the line of impact are found to have "two peaks", one due to the bullet impact and the other due to the bullet tumbling. Contours of the von Mises stress and of the effective plastic strain in the gelatin block imply that a very small region adjacent to the cavity surface is plastically deformed. The angle of attack is found to noticeably affect the penetration depth at the instant of the bullet tumbling through 90°. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Temperature matching of multilayer insulation to penetrations

    NASA Astrophysics Data System (ADS)

    Johnson, W. L.; Plachta, D. W.; Rhys, N. O.; Kelly, A. O.

    2014-01-01

    To accurately predict the heat load into a cryogenic tank or cold mass which includes multilayer insulation (MLI), heat loads other than just through the pristine MLI must be accounted for. One such type of heat load is the integration of the MLI system around penetrations. While a number of different methods that have been developed, the ideal solution would be one in which there are zero thermal losses due to the integration. Theoretically, the be st method to achieving zero integration losses is to match the individual MLI temperature layers with the corresponding penetration location having the same temperature; this method is known as temperature matching. Recently, NASA has employed temperature matching integration of multilayer insulation systems onto several different cryogenic tanks with different structural elements and attachments. T esting included the Methane Lunar Surface Thermal Control testing at Glenn Research Center, the CRYOTE Ground Test Article testing at Marshall Space Flight Center, and the Penetration Calorimetery work done at Kennedy Space Center. Each test was instrumented to determine the effects of temperature matching within MLI and each system was designed in a different manner. The testing showed that temperature matching can indeed produce nearly zero thermal losses. However, our findings show that there are many practical limitations to this approach. Temperature matching integration schemes were found to be very sensitive to thermal environmental changes and even tank liquid level changes. The approach is therefore considered useful only for a select few cases and not useful for most engineering applications.

  3. Penetrating eye injuries in road traffic accidents.

    PubMed

    Patel, B C; Morgan, L H

    1988-03-01

    A review of all penetrating eye injuries treated by the Manchester Eye Hospital over four years (1 February 1982-31 January 1986) was undertaken. One hundred and ninety-six penetrating eye injuries were seen, of which 16 (8.2%) were due to road traffic accidents. Eight patients (nine eyes) were seen in the 12 months prior to the introduction of the seat-belt legislation on 1 February 1983. None of these patients was wearing a seat-belt whereas two of the eight patients (10 eyes) seen after the seat-belt legislation were. Both these patients suffered severe visual loss due to intraocular glass from shattered windscreens. Three patients had bilateral penetrating eye injuries, one before and two after the seat-belt legislation. Two of the nine eyes involved prior to the legislation and three of the 10 eyes after the legislation had an eventual visual acuity of 6/12 or better. In the majority of patients, failure to wear seat-belts or defective use is to blame. Flying glass from shattered toughened windscreens is a preventable danger. Nine of the 16 patients were first seen in the general accident and emergency department and, of these, seven did not have visual acuities recorded prior to referral to an ophthalmologist. The importance of measurement of the visual acuity and detection of an afferent pupillary defect is stressed based on these findings.

  4. Penetrating ocular injuries in the home.

    PubMed

    Bhogal, G; Tomlins, P J; Murray, P I

    2007-03-01

    We studied the prevalence and aetiology of penetrating ocular injuries, in particular ones that were sustained whilst undertaking Do It Yourself (DIY) or gardening in the domestic environment. We also examined the extent of eye safety promotion in DIY stores and garden centres and on their websites. We conducted a case note review of patients who underwent surgery for penetrating ocular trauma between January 2000 and June 2004. Eight DIY stores and garden centres and 10 websites were visited and evaluated using standardized questions. Of the 85 patients identified, 35 (41.2%) patients had injuries that occurred in the home with 10 patients having visual acuities of <6/60 at final follow up. Accidents from DIY or gardening were the cause in 17 of 33 (51.5%) patients, with a failure to wear eye protection in all cases. Overall, DIY stores and garden centres were poor at promoting eye safety both in their stores and on their websites. The home is a frequent place for severe penetrating ocular injury, with highly popular pastimes such as DIY and gardening as common causes. As many of these injuries are preventable, additional safety information is essential to educate the public on the potential dangers of these pastimes.

  5. Penetration in bimodal, polydisperse granular material.

    PubMed

    Kouraytem, N; Thoroddsen, S T; Marston, J O

    2016-11-01

    We investigate the impact penetration of spheres into granular media which are compositions of two discrete size ranges, thus creating a polydisperse bimodal material. We examine the penetration depth as a function of the composition (volume fractions of the respective sizes) and impact speed. Penetration depths were found to vary between δ=0.5D_{0} and δ=7D_{0}, which, for mono-modal media only, could be correlated in terms of the total drop height, H=h+δ, as in previous studies, by incorporating correction factors for the packing fraction. Bimodal data can only be collapsed by deriving a critical packing fraction for each mass fraction. The data for the mixed grains exhibit a surprising lubricating effect, which was most significant when the finest grains [d_{s}∼O(30) μm] were added to the larger particles [d_{l}∼O(200-500) μm], with a size ratio, ε=d_{l}/d_{s}, larger than 3 and mass fractions over 25%, despite the increased packing fraction. We postulate that the small grains get between the large grains and reduce their intergrain friction, only when their mass fraction is sufficiently large to prevent them from simply rattling in the voids between the large particles. This is supported by our experimental observations of the largest lubrication effect produced by adding small glass beads to a bed of large sand particles with rough surfaces.

  6. Penetration in bimodal, polydisperse granular material

    NASA Astrophysics Data System (ADS)

    Kouraytem, N.; Thoroddsen, S. T.; Marston, J. O.

    2016-11-01

    We investigate the impact penetration of spheres into granular media which are compositions of two discrete size ranges, thus creating a polydisperse bimodal material. We examine the penetration depth as a function of the composition (volume fractions of the respective sizes) and impact speed. Penetration depths were found to vary between δ =0.5 D0 and δ =7 D0 , which, for mono-modal media only, could be correlated in terms of the total drop height, H =h +δ , as in previous studies, by incorporating correction factors for the packing fraction. Bimodal data can only be collapsed by deriving a critical packing fraction for each mass fraction. The data for the mixed grains exhibit a surprising lubricating effect, which was most significant when the finest grains [ds˜O (30 ) μ m ] were added to the larger particles [dl˜O (200 -500 ) μ m ] , with a size ratio, ɛ =dl/ds , larger than 3 and mass fractions over 25%, despite the increased packing fraction. We postulate that the small grains get between the large grains and reduce their intergrain friction, only when their mass fraction is sufficiently large to prevent them from simply rattling in the voids between the large particles. This is supported by our experimental observations of the largest lubrication effect produced by adding small glass beads to a bed of large sand particles with rough surfaces.

  7. Cutaneous mucormycosis secondary to penetrative trauma.

    PubMed

    Zahoor, Bilal; Kent, Stephen; Wall, Daryl

    2016-07-01

    Mucormycosis is a rare but serious sequelae of penetrating trauma [1-5]. In spite of aggressive management, mortality remains high due to dissemination of infection. We completed a review of literature to determine the most optimal treatment of cutaneous mucormycosis which occurs secondary to penetrating trauma. We completed a review regarding the management of mucormycosis in trauma patients. We selected a total of 36 reports, of which 18 were case-based, for review. Surgical debridement is a primary predictor of improved outcomes in the treatment of mucormycosis [3,6,7]. Anti-fungal therapy, especially lipid soluble formulation of Amphotericin B, is helpful as an adjunct or when surgical debridement has been maximally achieved. Further research is needed to fully evaluate the impact of topical dressings; negative pressure wound therapy is helpful. An aggressive and early surgical approach, even at the expense of disfigurement, is necessary to reduce mortality in the setting of cutaneous mucormycosis that results from penetrating trauma [4,8,9]. Anti-fungal therapy and negative pressure wound therapy are formidable adjuncts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Ballistic penetration response of intermetallic matrix composites

    SciTech Connect

    Kumar, K.S.; DiPietro, M.S. )

    1995-03-01

    Titanium aluminides and their composites exhibit about the same density as alumina, are tougher and can be produced by conventional casting and powder metallurgy techniques; further, they can be ground and machined more easily than alumina and lend themselves to better microstructural manipulation via heat treatments. Graded composite tiles with a high refractory reinforcement content on the outside and a lower amount on the inside may provide the desired abrasion resistance and toughness to effectively stop an incoming projectile. Likewise, alternating layers of hard and soft materials (e.g. Ti foils and TiAl) suitably graded in their spacings can serve as an effective armor tile. Testing of these materials gave the following conclusions: (1) Titanium aluminide composites are comparable to alumina in ballistic penetration resistance (for BS-41 and M-61 AP threats, and from the work of Chin and Woolsey, to long-rod penetrators) with perhaps improved resistance to shattering. (2) Incorporation of a residual compressive stress in the titanium aluminide composite tile significantly improved its penetration resistance. This concept could be utilized to decrease the required minimum tile thickness and hence, overall system weight.

  9. Value of storage with increased renewable penetration.

    SciTech Connect

    Brainard, James Robert; Roach, Jesse Dillon

    2010-10-01

    The problem statement for this project is: (1) Renewable energy portfolio standards - (a) high penetration of intermittent and variable renewable generation on the grid, (b) utilities constrained by NERC Control Performance Standards, (c) requires additional resources to match generation with load; and (2) mitigation of impacts with energy storage - at what level of renewable penetration does energy storage become an attractive value proposition. Use a simplified, yet robust dispatch model that: (a) incorporates New Mexico Balance Area load and wind generation data, (b) distributes the load among a suite of generators, (c) quantifies increased generation costs with increased penetration of intermittent and variable renewable generation - fuel, startup, shut down, ramping, standby, etc., (d) tracks and quantifies NERC pentalties and violations, and (e) quantifies storage costs. Dispatch model has been constructed and it: (a) accurately distributes a load among a suite of generators, (b) quantifies duty cycle metrics for each of the generators - cumulative energy production, ramping and non ramping duration, spinning reserves, number of start-ups, and shut down durations, etc., (c) quantifies energy exchanges - cumulative exchanges, duration, and number of exchanges, (d) tracks ACE violations.

  10. Penetrating chest wound of the foetus.

    PubMed

    Wandaogo, Albert; Tapsoba, Toussaint Wendlamita; Ouédraogo, Isso; Béré, Bernadette; Ouédraogo, S F; Bandré, E

    2016-01-01

    Traumas of the foetus caused by stabbings are rare but actually life-threatening for both the foetus and the mother. We report a case of penetrating chest wound on a baby taken from the obstetrics unit to the paediatric surgical department. His mother was assaulted by his father, a mentally sick person with no appropriate follow-up. The foetus did not show any sign of vital distress. Surgical exploration of the wound has revealed a section of the 10 th rib, a laceration of the pleura and a tearing of the diaphragm. A phrenorraphy and a pleural drainage were performed. The new-born and its mother were released from hospital after 5 days and the clinical control and X-ray checks 6 months later showed nothing abnormal. We insisted a medical, psychiatric follow-up be initiated for the father. As regards pregnant women with penetrating wounds, the mortality rate of the foetus is 80%. The odds are good for our newborn due to the mild injuries and good professional collaboration of the medical staff. Penetrating transuterine wounds of the foetus can be very serious. The health care needed should include many fields due to the mother and the foetus' lesions extreme polymorphism. In our case, it could have prevented by a good psychiatric followed up of the offender.

  11. The role of testosterone in trichloroethylene penetration in vitro

    SciTech Connect

    McCormick, K.; Abdel-Rahman, M.S. )

    1991-02-01

    Sex differences are known to exist in the metabolism and bioavailability of trichloroethylene (TCE). This study revealed that dermal penetration of ({sup 14}C)TCE in vitro was twofold greater in untreated female than in untreated male Sprague-Dawley rats. Since testosterone has been shown to mediate a wide variety of sex differences, its role in dermal penetration of ({sup 14}C)TCE was investigated. Penetration was measured by using an in vitro evaporation-penetration cell with a 10-hour collection period. Depriving male rats of testosterone (by castration) resulted in increased values for total penetration, area under the curve (AUC), and penetration slopes compared to those found in the female control group. Administration of testosterone to female animals produced values for total penetration, AUC, and penetration slopes significantly lower than those of the female control group.

  12. Deploying High Penetration Photovoltaic Systems: A Case Study

    SciTech Connect

    Coddington, M. H.; Baca, D.; Kroposki, B. D.; Basso, T.

    2011-01-01

    Photovoltaic (PV) system capacity penetration, or simply 'penetration,' is often defined as the rated power output of the aggregate PV systems on a distribution circuit segment divided by the peak load of that circuit segment. Industry experts agree that a single value defining high penetration is not universally applicable. However, it is generally agreed that a conservative value to designate high penetration is the condition when the ratio of aggregate PV systems ratings to peak load exceeds 15%. This case study illustrates the case of a distribution feeder which is able to accommodate a traditional capacity penetration level of 47%, and perhaps more. New maximum penetration levels need to be defined and verified and enhanced definitions for penetration on a distribution circuit need to be developed. The new penetration definitions and studies will help utility engineers, system developers, and regulatory agencies better agree what levels of PV deployment can be attained without jeopardizing the reliability and power quality of a circuit.

  13. Capillary Penetration into Inclined Circular Glass Tubes.

    PubMed

    Trabi, Christophe L; Ouali, F Fouzia; McHale, Glen; Javed, Haadi; Morris, Robert H; Newton, Michael I

    2016-02-09

    The spontaneous penetration of a wetting liquid into a vertical tube against the force of gravity and the imbibition of the same liquid into a horizontal tube (or channel) are both driven by capillary forces and described by the same fundamental equations. However, there have been few experimental studies of the transition from one orientation to the other. We report systematic measurements of capillary penetration of polydimethylsiloxane oils of viscosities 9.6, 19.2, and 48.0 mPa·s into glass capillary tubes. We first report the effect of tube radii R between 140 and 675 μm on the dynamics of spontaneous imbibition. We show that the data can be fitted using the exact numerical solution to the governing equations and that these are similar to fits using the analytical viscogravitational approximation. However, larger diameter tubes show a rate of penetration slower than expected using an equilibrium contact angle and the known value of liquid viscosity. To account for the slowness, an increase in viscosity by a factor (η/ρ)(scaling) is needed. We show full agreement with theory requires the ratio R/κ(-1) ∼ 0.1 or less, where κ(-1) is the capillary length. In addition, we propose an experimental method that enables the determination of the dynamic contact angle during imbibition, which gives values that agree with the literature values. We then report measurements of dynamic penetration into the tubes of R = 190 and 650 μm for a range of inclination angles to the horizontal, φ, from 5 to 90°. We show that capillary penetration can still be fitted using the viscogravitational solution, rather than the Bosanquet solution which describes imbibition without gravity, even for inclination angles as low as 10°. Moreover, at these low angles, the effect of the tube radius is found to diminish and this appears to relate to an effective capillary length, κ(-1)(φ) = (γ(LV)/ρg sin φ)(1/2).

  14. Verifying Removal Of Red Penetrant Dye From Inspected Welds

    NASA Technical Reports Server (NTRS)

    Torkelson, Jan R.

    1996-01-01

    Clean surface assured for more sensitive inspection with fluorescent penetrant dye. Simple procedure devised to ensure visible (red) penetrant dye used to identify flaws in welded surface completely removed from surface. Consists in applying reversible penetrant developer to surface to be inspected.

  15. Optic nerve sheath diameter threshold by ocular ultrasonography for detection of increased intracranial pressure in Korean adult patients with brain lesions

    PubMed Central

    Lee, Si Un; Jeon, Jin Pyeong; Lee, Hannah; Han, Jung Ho; Seo, Mingu; Byoun, Hyoung Soo; Cho, Won-Sang; Ryu, Ho Geol; Kang, Hyun-Seung; Kim, Jeong Eun; Kim, Heung Cheol; Jang, Kyung-Sool

    2016-01-01

    Abstract Optic nerve sheath diameter (ONSD) seen on ocular US has been associated with increased intracranial pressure (IICP). However, most studies have analyzed normal range of ONSD and its optimal cut-off point for IICP in Caucasian populations. Considering ONSD differences according to ethnicity, previous results may not accurately reflect the association between IICP and ONSD in Koreans. Therefore, we conducted this study to investigate normal range of ONSD and its optimal threshold for detecting IICP in Korean patients. This prospective multicenter study was performed for patients with suspected IICP. ONSD was measured 3 mm behind the globe using a 13-MHz US probe. IICP was defined as significant brain edema, midline shift, compression of ventricle or basal cistern, effacement of sulci, insufficient gray/white differentiation, and transfalcine herniation by radiologic tests. The results of the ONSD are described as the median (25th–75th percentile). The differences of ONSD according to disease entity were analyzed. A receiver operator characteristic (ROC) curve was generated to determine the optimal cut-off point for identifying IICP. A total of 134 patients were enrolled. The patients were divided into 3 groups as follows: patients with IICP, n = 81 (60.5%); patients without IICP, n = 27 (20.1%); and control group, n = 26 (19.4%). ONSD in patients with IICP (5.9 mm [5.8–6.2]) is significantly higher than those without IICP (5.2 mm [4.8–5.4]) (P < 0.01) and normal control group (4.9 mm [4.6–5.2]) (P < 0.001). Between patients without IICP and normal control group, the difference of ONSD did not reach statistical significance (P = 0.31). ONSD >5.5 mm yielded a sensitivity of 98.77% (95% CI: 93.3%–100%) and a specificity of 85.19% (95% CI: 66.3%–95.8%). In conclusion, the optimal cut-off point of ONSD for identifying IICP was 5.5 mm. ONSD seen on ocular US can be a feasible method for detection and serial monitoring of ICP in

  16. Field Testing the STRATA Ground Penetrating Radar for Mars

    NASA Astrophysics Data System (ADS)

    Williams, K. K.; Grant, J. A.; Leuschen, C. J.; Schutz, A. E.

    2005-12-01

    With the MARSIS and SHARAD orbital radar sounders now in operation at and in transit to Mars, respectively, radar investigation of the deep structure of Mars down to several kilometers is underway. By contrast, optical and thermal instruments both in orbit and on the surface have provided information about the top several millimeters and the Mars Exploration Rovers have dug to several cm with their wheels. Nevertheless, little is known about the shallow subsurface of Mars to depths of meters except at locations where continuation of outcrop into the subsurface can be extrapolated. As the methods for exploring Mars evolve, the utility of ground penetrating radar (GPR) for investigating the shallow subsurface of that planet is being considered. GPR has been used for several decades on Earth as a non-invasive tool for studying subsurface structures and stratigraphy for applications in geology, engineering, and archaeology. The STRATA GPR for Mars has been developed as an adaptable, low power, compact, rover-mounted instrument capable of penetrating 10-20 m to reveal subsurface information. Field-testing of this instrument has taken place in volcanic, cratered, permafrost, and deltaic settings, and data collected at 400 MHz possess vertical resolutions of a few cm, sufficient to interpret the subsurface geologic setting. Results from the permafrost environment showed detection of buried massive ground ice as well as the base of the active layer. GPR analysis of this ice distribution was confirmed by resistivity measurements. The fine vertical resolution and good penetration in a variety of geologic settings show that the STRATA instrument provides data quality indistinguishable from commercial systems used on Earth. Most recently, the STRATA instrument has been tested in aeolian and filled crater environments. Data were collected over a sand dune overlying a basalt lava flow near St. Anthony, ID, and at the Campo del Cielo impact crater field in Chaco Province

  17. Temporal discrimination, a cervical dystonia endophenotype: penetrance and functional correlates.

    PubMed

    Kimmich, Okka; Molloy, Anna; Whelan, Robert; Williams, Laura; Bradley, David; Balsters, Joshua; Molloy, Fiona; Lynch, Tim; Healy, Daniel G; Walsh, Cathal; O'Riordan, Seán; Reilly, Richard B; Hutchinson, Michael

    2014-05-01

    The pathogenesis of adult-onset primary dystonia remains poorly understood. There is variable age-related and gender-related expression of the phenotype, the commonest of which is cervical dystonia. Endophenotypes may provide insight into underlying genetic and pathophysiological mechanisms of dystonia. The temporal discrimination threshold (TDT)-the shortest time interval at which two separate stimuli can be detected as being asynchronous-is abnormal both in patients with cervical dystonia and in their unaffected first-degree relatives. Functional magnetic resonance imaging (fMRI) studies have shown that putaminal activation positively correlates with the ease of temporal discrimination between two stimuli in healthy individuals. We hypothesized that abnormal temporal discrimination would exhibit similar age-related and gender-related penetrance as cervical dystonia and that unaffected relatives with an abnormal TDT would have reduced putaminal activation during a temporal discrimination task. TDTs were examined in a group of 192 healthy controls and in 158 unaffected first-degree relatives of 84 patients with cervical dystonia. In 24 unaffected first-degree relatives, fMRI scanning was performed during a temporal discrimination task. The prevalence of abnormal TDTs in unaffected female relatives reached 50% after age 48 years; whereas, in male relatives, penetrance of the endophenotype was reduced. By fMRI, relatives who had abnormal TDTs, compared with relatives who had normal TDTs, had significantly less activation in the putamina and in the middle frontal and precentral gyri. Only the degree of reduction of putaminal activity correlated significantly with worsening of temporal discrimination. These findings further support abnormal temporal discrimination as an endophenotype of cervical dystonia involving disordered basal ganglia circuits.

  18. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants.

    PubMed

    Nielson, K K; Rogers, V C; Holt, R B; Pugh, T D; Grondzik, W A; de Meijer, R J

    1997-10-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP < or = 60 Pa) was negligible for the slabs (10(-16) m2 permeability), pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not.

  19. Optic glioma

    MedlinePlus

    Glioma - optic; Optic nerve glioma; Juvenile pilocytic astrocytoma; Brain cancer - optic glioma ... Optic gliomas are rare. The cause of optic gliomas is unknown. Most optic gliomas are slow-growing ...

  20. Evaluation of time-resolved multi-distance methods to retrieve absorption and reduced scattering coefficients of adult heads in vivo: Optical parameters dependences on geometrical structures of the models used to calculate reflectance

    NASA Astrophysics Data System (ADS)

    Tanifuji, T.

    2016-03-01

    Time-resolved multi-distance measurements are studied to retrieve absorption and reduced scattering coefficients of adult heads, which have enough depth sensitivity to determine the optical parameters in superficial tissues and brain separately. Measurements were performed by putting the injection and collection fibers on the left semi-sphere of the forehead, with the injection fiber placed toward the temporal region, and by moving the collection fiber between 10 and 60 mm from the central sulcus. It became clear that optical parameters of the forehead at all collection fibers were reasonably determined by selecting the appropriate visibility length of the geometrical head models, which is related to head surface curvature at each position.

  1. Phenomenological Investigation of Rapid Projectile Penetration in Granular Media

    NASA Astrophysics Data System (ADS)

    Omidvar, Mehdi

    There has been a recent flurry of research in rapid penetration into granular media, motivated by military and civilian applications including underground target penetration, design of fortifications, drilling for resource extraction, offshore foundations and anchors, probing of in situ mechanical properties, and study of high strain rate response of granular media, among others. The present study contributes to the state of the art in rapid penetration into granular media, by producing data at the macro and meso scales. In-house projectile accelerators are used to launch projectiles into laboratory scale physical models. The experimental program is divided into two sections. In the first section, penetration tests are performed at impact velocities in the range of 60-300 m/s. High-speed imaging and photonic Doppler velocimetry are used to record time history of penetration. In the second section, low velocity penetration tests are performed in refractive index matched transparent soils. Images are acquired form a mid plane within the sample. Digital image correlation is employed to describe granular kinematics. Macro scale test results point to the existence of at least two transition regimes in penetration resistance. The first, occurring at penetration velocities of approximately 60- 80 m/s, may be due the role of particle crushing, while the second is linked to frictional resistance dominating over inertial resistance at penetration velocities below approximately 15 m/s. It is also found that the role of nose shape is related to particle crushing. An attached false cone forms ahead of the projectile due to significant particle crushing, rendering nose shape effects less significant. Packing density and saturation are also found to affect penetration characteristics. Penetration tests in transparent soils reveal significant differences between quasi-static and dynamic penetration. Greater vertical displacements occur ahead of the projectile in dynamic

  2. Surface penetrators for planetary exploration: Science rationale and development program

    NASA Technical Reports Server (NTRS)

    Murphy, J. P.; Reynolds, R. T.; Blanchard, M. B.; Clanton, U. S.

    1981-01-01

    Work on penetrators for planetary exploration is summarized. In particular, potential missions, including those to Mars, Mercury, the Galilean satellites, comets, and asteroids are described. A baseline penetrator design for the Mars mission is included, as well as potential instruments and their status in development. Penetration tests in soft soil and basalt to study material eroded from the penetrator; changes in the structure, composition, and physical properties of the impacted soil; seismic coupling; and penetrator deflection caused by impacting rocks, are described. Results of subsystem studies and tests are given for design of entry decelerators, high-g components, thermal control, data acquisition, and umbilical cable deployment.

  3. Effect of Liquid Penetrant Sensitivity on Probability of Detection

    NASA Technical Reports Server (NTRS)

    Parker, Bradford H.

    2008-01-01

    The objective of the task is to investigate the effect of liquid penetrant sensitivity level on probability of crack detection (POD). NASA-STD-5009 currently requires the use of only sensitivity level 4 liquid penetrants. This requirement is based on the fact that the data generated in the NTIAC Nondestructive Evaluation (NDE) Capabilities Data Book was produced using only sensitivity level 4 penetrants. Many NDE contractors supporting NASA Centers routinely use sensitivity level 3 penetrants. Because of the new NASA-STD-5009 requirement, these contractors will have to either shift to sensitivity level 4 penetrants or perform formal POD demonstration tests to qualify their existing process.

  4. A novel function of neuroglobin for neuroregeneration in mice after optic nerve injury.

    PubMed

    Sugitani, Kayo; Koriyama, Yoshiki; Sera, Mayuko; Arai, Kunizo; Ogai, Kazuhiro; Wakasugi, Keisuke

    2017-09-23

    Neuroglobin (Ngb) is a recently discovered heme protein in the vertebrate brain that can bind to oxygen molecules. Mammalian Ngb plays a crucial role in neuroprotection under conditions of oxidative stress. To investigate other potential functions of Ngb, we investigated the mouse retinal Ngb system following optic nerve injury. In the retina of control mice, Ngb immunoreactivity was limited to the retinal ganglion cell (RGC) layer, and this immunoreactivity rapidly decreased to less than 50% of the control level 5 days after optic nerve injury. On the basis of this decrease, we designed in vivo experiments with enhanced expression of Ngb using adult mouse retina. The enhanced expression of Ngb was achieved by injecting chimeric human Ngb protein, which included the cell membrane-penetrating module of fish Ngb. One-day pretreatment with chimeric Ngb increased immunoreactivity levels of Ngb two-fold in mouse RGCs and increased the number of surviving RGCs three-fold by 14 days after optic nerve injury compared with vehicle controls. Furthermore, in the mouse retinas showing enhanced Ngb expression, several regenerating central optic axons exhibited outgrowth and were found to pass through the nerve crush site 14 days after nerve injury. No such regenerating optic axons were observed in the control mouse optic nerve during the same time frame. The data obtained from in vivo experiments strongly indicate that mammalian Ngb has neuroprotective and neuroregenerative properties. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Influence of some plant extracts on the transdermal absorption and penetration of marker penetrants.

    PubMed

    Muhammad, Faqir; Wiley, June; Riviere, Jim E

    2017-03-01

    Plant extracts are commonly used in a number of cosmetics and topical pharmaceuticals. The effects on such extracts on the subsequent dermal absorption and penetration of other cosmetic ingredients needs to be evaluated. This study demonstrates the effect of some natural extracts routinely found in cosmetics on the dermal absorption and penetration of marker penetrants. Aqueous ethanolic extracts of Gingko biloba, Lavendula angustifolia, Rosmarinus officinale, Mentha piperita, Matricaria recutita, Persea Americana, Avena sativa, Zingiber officinale were prepared. (14)C-caffeine and (14)C-salicylic acid were topically dosed with either 10% solutions of natural extracts or ethanol (control) using a flow through in vitro porcine skin diffusion system. Samples were analyzed with liquid scintillation counter. The parameters of flux, permeability, and percent dose absorbed/retained were calculated and compared. The dermal absorption of (14)C-caffeine was significantly higher (p ≥ 0.05) with avocado, chamomile, ginger and peppermint extract as compared to the control ethanol; while dermal absorption of (14)C-salicylic acid was significantly greater with ginkgo and chamomile extract as compared to ethanol. Over four fold increase in flux and permeability of caffeine with avocado extract was observed while chamomile and peppermint extracts increased the flux and permeability of caffeine over three fold. Gingko and chamomile extracts increased salicylic acid's flux and permeability by two fold. Sum of %dose skin residue + %absorption in receptor fluid for different extracts exhibited the similar trend as shown by flux and permeability. The other natural extracts tested did not produce statistically significant effects on dermal penetration parameters for both caffeine and salicylic acid (p ≥ 0.05). These results emphasize the influence of natural plant extracts on the transdermal penetration of hydrophilic (caffeine) and hydrophobic (salicylic acid

  6. Market penetration scenarios for fuel cell vehicles

    SciTech Connect

    Thomas, C.E.; James, B.D.; Lomax, F.D. Jr.

    1997-12-31

    Fuel cell vehicles may create the first mass market for hydrogen as an energy carrier. Directed Technologies, Inc., working with the US Department of Energy hydrogen systems analysis team, has developed a time-dependent computer market penetration model. This model estimates the number of fuel cell vehicles that would be purchased over time as a function of their cost and the cost of hydrogen relative to the costs of competing vehicles and fuels. The model then calculates the return on investment for fuel cell vehicle manufacturers and hydrogen fuel suppliers. The model also projects the benefit/cost ratio for government--the ratio of societal benefits such as reduced oil consumption, reduced urban air pollution and reduced greenhouse gas emissions to the government cost for assisting the development of hydrogen energy and fuel cell vehicle technologies. The purpose of this model is to assist industry and government in choosing the best investment strategies to achieve significant return on investment and to maximize benefit/cost ratios. The model can illustrate trends and highlight the sensitivity of market penetration to various parameters such as fuel cell efficiency, cost, weight, and hydrogen cost. It can also illustrate the potential benefits of successful R and D and early demonstration projects. Results will be shown comparing the market penetration and return on investment estimates for direct hydrogen fuel cell vehicles compared to fuel cell vehicles with onboard fuel processors including methanol steam reformers and gasoline partial oxidation systems. Other alternative fueled vehicles including natural gas hybrids, direct injection diesels and hydrogen-powered internal combustion hybrid vehicles will also be analyzed.

  7. Percutaneous penetration enhancers in cigarette mainstream smoke.

    PubMed

    Smith, Carr J; Perfetti, Thomas A; Garg, Rajni; Martin, Patricia; Hansch, Corwin

    2004-01-01

    Percutaneous penetration enhancers (PPEs) are chemicals used to enhance the transdermal delivery of drugs. Fifty-eight of the approximately 150 PPEs used for the transdermal delivery of drugs have been reported in cigarette mainstream smoke (MS). MS is a complex aerosol of minute liquid droplets (termed the particulate phase) suspended within a mixture of gases (CO(2), CO, NO(x), etc.) and semi-volatile compounds. The gases and many of the semi-volatiles are termed the vapor phase. Twenty-nine of the 58 PPEs have been identified in MS vapor phase, 15 in the particulate phase and 14 in both the vapor and particulate phases. There is a tendency for MS PPEs to be hydrophobic, with 40 of the 58 compounds (69%) being either hydrophobic or strongly hydrophobic, and only 24% being hydrophilic. Many of the 4800 known constituents of MS are hydrophilic and would not be expected to readily cross cell membranes or penetrate tissue when delivered as single compounds. The in vivo effect on biological activity of the juxtaposition within the cigarette smoke aerosol of the large number of hydrophilic constituents with the 58 PPEs is currently unknown. As an initial step in understanding this potential complex interaction, the 58 PPEs in MS have been identified and a number of molecular parameters related to the ability to penetrate tissue have been calculated, including MS concentration, measured and calculated base ten logarithm of the octanol-water partition coefficient (Mlog P and Clog P), molecular volume (MgVol) and calculated molar refractivity (CMR).

  8. Analysis of liquid penetration in paper structures by advanced imaging techniques

    NASA Astrophysics Data System (ADS)

    Arthur, Beth Ann

    Ink penetration in paper is influenced by the structure of the interfiber and intrafiber void spaces and the surface characteristics of the fibers. This dissertation describes new techniques to determine the influence of the fiber surfaces and the cell wall internal structure on ink spreading and penetration. The location and penetration of ink is demonstrated by optical, scanning electron, confocal laser scanning, and transmission electron (TEM) microscopy methods. Ink penetration, as determined by each of these methods, is compared. The hemicelluloses of the fiber's internal void surfaces can be determined by immunochemical labeling in conjunction with TEM imaging. It is demonstrated through the use of primary monoclonal antibodies with specificity for hemicelluloses with a secondary colloidal gold marker. This technique provides a way to visualize the location of hemicelluloses inside the cell wall and on the surfaces of nanopores. Combining paper structure with fluid spreading and wicking models can identify the influence of fiber surfaces and the cell wall on drop absorption. Ink spreading coefficients for such modeling are determined through a series of designed experiments (DoE) and comparisons to a theoretical sessile drop. Application: Microscopic techniques used to determine biological and physical locations in plants on a fibrous level also can be used to study ink diffusion, water uptake, and other characteristics of fibrous material. Key Words: Immunolableing of hemicelluloses, DoE, drop spread modeling, ink diffusion.

  9. Optimizing penetration depth, contrast, and resolution in 3D dermatologic OCT

    NASA Astrophysics Data System (ADS)

    Aneesh, Alex; Považay, Boris; Hofer, Bernd; Zhang, Edward Z.; Kendall, Catherine; Laufer, Jan; Popov, Sergei; Glittenberg, Carl; Binder, Susanne; Stone, Nicholas; Beard, Paul C.; Drexler, Wolfgang

    2010-02-01

    High speed, three-dimensional optical coherence tomography (3D OCT) at 800nm, 1060nm and 1300nm with approximately 4μm, 7μm and 6μm axial and less than 15μm transverse resolution is demonstrated to investigate the optimum wavelength region for in vivo human skin imaging in terms of contrast, dynamic range and penetration depth. 3D OCT at 1300nm provides deeper penetration, while images obtained at 800nm were better in terms of contrast and speckle noise. 1060nm region was a compromise between 800nm and 1300nm in terms of penetration depth and image contrast. Optimizing sensitivity, penetration and contrast enabled unprecedented visualization of micro-structural morphology underneath the glabrous skin, hairy skin and in scar tissue. Higher contrast obtained at 800 nm appears to be critical in the in vitro tumor study. A multimodal approach combining OCT and PA helped to obtain morphological as well as vascular information from deeper regions of skin.

  10. Space station integrated wall design and penetration damage control. Task 3: Theoretical analysis of penetration mechanics

    NASA Technical Reports Server (NTRS)

    Bjorkman, M. D.; Geiger, J. D.; Wilhelm, E. E.

    1987-01-01

    The efforts to provide a penetration code called PEN4 version 10 is documented for calculation of projectile and target states for the impact of 2024-T3 aluminum, R sub B 90 1018 steel projectiles and icy meteoroids onto 2024-T3 aluminum plates at impact velocities from 0 to 16 km/s. PEN4 determines whether a plate is perforated by calculating the state of fragmentation of projectile and first plate. Depth of penetration into the second to n sup th plate by fragments resulting from first plate perforation is determined by multiple cratering. The results from applications are given.

  11. Shaped Charge Jet Penetration of Discontinuous Media

    DTIC Science & Technology

    1977-07-01

    dimensional Computer Code 20L A96TRACT (Cidow on tevem sM N nmeaev and IlmttUy by block number) A computer study was made of the penetration by a copper ...operational at the Ballistic1Research Laboratory. These codes are OIL, 1 TOIL, 2 DORF, 3 and HELP,4 ,5 which are Eulerian formulated, and HEMP ,6 which...computer study of rod-target interaction consisted of a copper rod, or jet, impacting normally upon a steel plate which, in turn, was backed-up by a semi

  12. [Penetrating abdominal wounds. Apropos of 330 cases].

    PubMed

    Nejjar, M; Bennani, S; Zerouali, O N

    1991-01-01

    Penetrating abdominal wounds are frequent and serious. 330 cases have been treated in the Department of Emergencies and visceral Surgery at Averroes Hospital of Casablanca from 1980 to 1990. The predominance of male sex is noted, and these wounds are always the result of aggression by white arm. All patients have been operated, the white laparotomy rate is of 36%. The classic interventionist attitude is still recommended in spite of this high rate, because our present conditions can't permit us a rigorous watching. According to abdominal lesions, the different interventions are reviewed, and their indications are detailed.

  13. Retained crossbow bolt after penetrating facial trauma.

    PubMed

    Shah, Manan U; Sridhara, Shankar K; Wolf, Jeffrey S; Ambro, Bryan T

    2016-01-01

    We present an unusual case of a retained crossbow bolt in the maxillofacial area of a 31-year-old man. While crossbow injuries are rare, this case is of interest because otolaryngologists are often faced with treating retained foreign objects after penetrating facial trauma. These cases are difficult to manage because of the complexity and variety of injuries that can occur during both the initial trauma and the removal. We focus on the management of the bolt's removal and provide a brief discussion of the relevant literature on crossbow injuries to the head and neck.

  14. Magnetic flux penetration into superconducting thin films.

    NASA Technical Reports Server (NTRS)

    Peabody, G. E.; Meservey, R.

    1972-01-01

    The quantum-interference technique developed by Meservey (1965) is used to measure directly the absolute value of the penetration depth in lead in tin superconducting thin films. The technique assumes that the change in phase of the superconducting wave function around any contour within the superconductor must be 2 pi n, where n is a nonnegative integer. Results show that the critical current of a superconducting interferometer with two parallel junctions is not strictly periodic in the applied magnetic flux with a period equal to the flux quantum because of the magnetic field dependence of the critical currents of the junctions.

  15. Filter Enhances Fluorescent-Penetrant-Inspecting Borescope

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Slip-on eyepiece for commercial ultraviolet-light borescope reduces both amount of short-wave ultraviolet light that reaches viewer's eye and apparent intensity of unwanted reflections of white light from surfaces undergoing inspection. Fits on stock eyepiece of borescope, which illuminates surface inspected with intense ultraviolet light. Surface, which is treated with fluorescent dye, emits bright-green visible light wherever dye penetrates - in cracks and voids. Eyepiece contains deep-yellow Wratten 15 (G) filter, which attenuates unwanted light strongly but passes yellow-green fluorescence so defects seen clearly.

  16. The Penetration of Fragments into Collection Media

    DTIC Science & Technology

    1989-01-01

    S_1-2(v/v )a dv1 (vo) = vl d0( represents the integral on the right in equation 4. In Collins’ test, the impact medium was Celotex , with a density of...8217 calibration data (Table A-I) gives v and P for numerous shots of the steel spheres into the Celotex impact medium. Tests yielding penetrations of...fragments impacting the Celotex impact medium. Collins’ data for small fragments (approximately the same mass as the calibration spheres), presented

  17. A novel approach to penetrator calculations

    SciTech Connect

    Budge, K.G.

    1998-08-01

    The author presents a novel method for calculating the penetration of soft targets by hard projectiles by using a combination of ALE and contact surface techniques. This method allows the bifurcation in the softer material (at the point of the projectile) to be represented without sacrificing the Lagrangian representation of either the harder material or the contact interface. A series of calculations using this method show good agreement with the experimental data of Forrestal et al. This method may prove useful for a range of semi-fluid/structure interactions with friction, including simulations of manufacturing processes.

  18. Radar penetration in the Amazonian rain forest

    NASA Technical Reports Server (NTRS)

    Pereiradacunha, Roberto; Ford, John

    1986-01-01

    Radar return from vegetation covered terrains is due to three components: the scattering resulting from the top surface of the vegetation canopy (surface scattering); the scattering which occurs within the vegetation layer (volume scattering); and the scattering which takes place at the surface below the vegetation canopy (ground scattering). Through the studies of selected areas in the Amazon Region a case is presented where most of the radar returns observed in radar imagery results from the scattering at the surface below vegetation layer (ground scattering). Thus, radar penetration occurred.

  19. [Penetrating ocular trauma with intraocular foreign body].

    PubMed

    Musat, O; Ochinciuc, Uliana; Gutu, Tatiana; Cristescu, T R; Coman, Corina

    2012-01-01

    We present the case of a 65 years old pacient which was admitted for the sudden decrease of visual acuity in the left eye, accompanied by ocular pain and conjunctival hiperemia, simptoms appeared after an ocular trauma. After the clinical and paraclinical examination we determined the diagnosis of OS: Penetrating ocular trauma with retention of a foreign body; posttraumatic cataract. Surgical treatement was warrented and we performed OS : Facoemulsification + PFK implant in sulcus + 23 Ga posterior vitrectomy + peeling of the posterior hyaloid membrane + extraction of the foreign body + LASER endofotocoagulation + transscleral cryotherapy + SF6 gas injection. The post-operatory evolution was favorable.

  20. Penetrating oil and method of preparation

    SciTech Connect

    Dulin, C.A.

    1987-03-10

    A penetrating oil is described comprising: (a) from about 1 part to about 5 parts of a formula oil comprising a lubricating oil and surface active agents, the lubricating oil having a viscosity of from between about 135 to about 220 SSU at 100/sup 0/F; (b) from about 20 parts to about 30 parts of a hydrocarbon-based viscosity controller having a viscosity of from between about 75 to 200 SSU 100/sup 0/F; and, (c) from about 65 to about 80 parts of a hydrocarbon-based volatility controller having a viscosity of from between about 32 to about 45 SSU 100/sup 0/F.

  1. Extensive Penetration of Evaporated Electrode Metals into Fullerene Films: Intercalated Metal Nanostructures and Influence on Device Architecture.

    PubMed

    Zhang, Guangye; Hawks, Steven A; Ngo, Chilan; Schelhas, Laura T; Scholes, D Tyler; Kang, Hyeyeon; Aguirre, Jordan C; Tolbert, Sarah H; Schwartz, Benjamin J

    2015-11-18

    Although it is known that evaporated metals can penetrate into films of various organic molecules that are a few nanometers thick, there has been little work aimed at exploring the interaction of the common electrode metals used in devices with fullerene derivatives, such as organic photovoltaics (OPVs) or perovskite solar cells that use fullerenes as electron transport layers. In this paper, we show that when commonly used electrode metals (e.g., Au, Ag, Al, Ca, etc.) are evaporated onto films of fullerene derivatives (such as [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)), the metal penetrates many tens of nanometers into the fullerene layer. This penetration decreases the effective electrical thickness of fullerene-based sandwich structure devices, as measured by the device's geometric capacitance, and thus significantly alters the device physics. For the case of Au/PCBM, the metal penetrates a remarkable 70 nm into the fullerene, and we see penetration of similar magnitude in a wide variety of fullerene derivative/evaporated metal combinations. Moreover, using transmission electron microscopy to observed cross-sections of the films, we show that when gold is evaporated onto poly(3-hexylthiophene) (P3HT)/PCBM sequentially processed OPV quasi-bilayers, Au nanoparticles with diameters of ∼3-20 nm are formed and are dispersed entirely throughout the fullerene-rich overlayer. The plasmonic absorption and scattering from these nanoparticles are readily evident in the optical transmission spectrum, demonstrating that the interpenetrated metal significantly alters the optical properties of fullerene-rich active layers. This opens a number of possibilities in terms of contact engineering and light management so that metal penetration in devices that use fullerene derivatives could be used to advantage, making it critical that researchers are aware of the electronic and optical consequences of exposing fullerene-derivative films to evaporated electrode metals.

  2. Ultra-deep penetration of temporally-focused two-photon excitation

    NASA Astrophysics Data System (ADS)

    Sela, Gali; Dana, Hod; Shoham, Shy

    2013-02-01

    Temporal focusing (TF) nonlinear microscopy enables simultaneous illumination of relatively large areas while maintaining optical sectioning, by relying on the sensitivity of multiphoton processes to pulse duration. Line temporal focusing (LITEF) combines temporal focusing in one plane (xz) and spatial focusing in the perpendicular plane (yz). The additional spatial focusing improves optical sectioning compared to wide field temporal focusing and exhibits improved performance in scattering medium. Two photon microscopy's ultimate depth of penetration is limited by out-of-focus excitation. This work explores whether LITEF can be used to address this limitation. Here, we present experimental results displaying the feasibility of ultra-deep penetration two-photon excitation in scattering media (<<1mm) using LITEF without significant distortions or out-of-focus-excitation. Our experimental setup is based on an amplified 800nm ultrafast laser where a dual-prism grating (DPG) is used as a diffractive element, allowing light to propagate on-axis throughout the optical setup, and providing a high diffraction efficiency. These results present new opportunities for ultra deep, optically sectioned 3D two photon imaging and stimulation within scattering biological tissue, beyond the known out-of-focus excitation limit.

  3. Derivation of effective penetration depth of femtosecond laser pulses in metal from ablation rate dependence on laser fluence, incidence angle, and polarization

    SciTech Connect

    Miyasaka, Yasuhiro; Hashida, Masaki; Nishii, Takaya; Inoue, Shunsuke; Sakabe, Shuji

    2015-01-05

    Ablation rate dependence on laser fluence for copper subjected to oblique femtosecond laser irradiation has been determined experimentally in order to investigate processing induced by oblique irradiation. A difference of ablation rate between p-polarized and s-polarized oblique irradiation is clearly observed. Effective penetration depth is defined to explain the ablation rate dependence instead of using optical penetration depth, which is treated as a key value for determining the ablation rate in conventional theory. The effective penetration depth for copper is presented in simple formulas as a function of laser incidence angle for each polarization.

  4. Posterior Vitreous Detachment With Microplasmin Alters the Retinal Penetration of Intravitreal Bevacizumab (Avastin) in Rabbit Eyes

    PubMed Central

    Goldenberg, David T.; Giblin, Frank J.; Cheng, Mei; Chintala, Shravan K.; Trese, Michael T.; Drenser, Kimberly A.; Ruby, Alan J.

    2010-01-01

    Purpose Intravitreal bevacizumab (Avastin) is frequently used for the treatment of age-related macular degeneration. Previous studies have demonstrated full thickness retinal penetration. Intravitreal recombinant microplasmin (MP) has been shown to successfully induce a posterior vitreous detachment (PVD) and vitreous liquefaction in animals. It has been suggested that a PVD may alter the retinal penetration of molecules in the vitreous cavity. The aim of this study was to compare bevacizumab (BV) retinal penetration in rabbit eyes with and without a MP-induced PVD. Methods Twelve adult rabbits were injected with 0.1 ml (0.4 mg) of MP into the vitreous cavity of one eye. One week later, the rabbits were injected with 0.05 ml (1.25 mg) of BV into both eyes. Both eyes of three rabbits each were harvested at 6, 12, 24, and 72 hours after the BV injection. Frozen retinal cross sections were prepared, and BV retinal penetration was evaluated with immunohistochemistry using a fluorescence-labeled antibody against BV. Two eyes from one rabbit were not injected with either agent and used as controls to compare the background autofluorescence. Peripapillary retinal sections were recorded with a digital camera, and intra-retinal BV fluorescence-labeled antibody was measured by qualitative photographic interpretation. Two additional rabbits received an intravitreal injection of 0.1 ml of MP in one eye. One week later, both eyes from each rabbit were enucleated and frozen retinal sections were prepared and analyzed with light microscopy to evaluate for histologic damage. Results Full thickness BV retinal penetration was observed throughout the retina in both eyes of each rabbit. All of the MP-injected eyes exhibited increased antibody labeling in retinas evaluated 6, 12, and 24 hours after BV injection when compared with the contralateral non-MP-injected eyes. By three days after BV injection, all eyes demonstrated decreased antibody labeling compared to earlier time periods

  5. Comprehensive analysis of the capillary depth in deep penetration laser welding

    NASA Astrophysics Data System (ADS)

    Fetzer, Florian; Boley, Meiko; Weber, Rudolf; Graf, Thomas

    2017-02-01

    Laser welding is the state of the art joining technology regarding productivity and thermal loads and stress on the workpiece. In deep penetration laser welding the quality of the resultant welds strongly depends on the stability of the capillary. The highly dynamic depth fluctuations are of major influence on the controllability of the laser welding process and on the prevention of weld defects. In the present paper the capillary dynamics is investigated by means of time- and spatially resolved in-process X-ray imaging and optical coherence tomography. The X-ray diagnostics allows measuring the geometry of the capillary with frame rates of 1 kHz, while the optical coherence tomography enables the determination of the capillary depth with an acquisition rate of up to 70 kHz. These measurements are correlated to time varying input laser power to provide profound insight in the dynamics of the laser welding process. The measurements are performed for copper, aluminum and mild steel. The capillary depth resulting from arbitrary laser power modulation was investigated. Thereby, the response of the capillary depth to laser power changes was determined. Based on these measurements the changes of the capillary depth in deep penetration laser welding were described by methods known from control theory. These analyses can be utilized to optimize control strategies, to calibrate transient simulations of deep penetration laser welding and to identify the influence of material properties.

  6. Stiffness of RBC optical confinement affected by optical clearing

    NASA Astrophysics Data System (ADS)

    Grishin, Oleg V.; Fedosov, Ivan V.; Tuchin, Valery V.

    2017-03-01

    In vivo optical trapping is a novel applied direction of an optical manipulation, which enables one to noninvasive measurement of mechanical properties of cells and tissues in living animals directly. But an application area of this direction is limited because strong scattering of many biological tissues. An optical clearing enables one to decrease the scattering and therefore increase a depth of light penetration, decrease a distortion of light beam, improve a resolution in imaging applications. Now novel methods had appeared for a measurement an optical clearing degree at a cellular level. But these methods aren't applicable in vivo. In this paper we present novel measurement method of estimate of the optical clearing, which are based on a measurement of optical trap stiffness. Our method may be applicable in vivo.

  7. Clinical study assessing the photosensitizer accumulation and light penetration for esophageal cancer prior to treatment by PDT

    NASA Astrophysics Data System (ADS)

    Bargo, Paulo R.; Jacques, Steven L.

    2001-07-01

    The FDA has approved PDT using Photofrin for certain esophageal and lung cancers, specifying an approved prescription of administered drug (mg/kg body weight) and administered light (J/linear cm of cylindrical fiber). This paper describes our development of a multi-optical fiber catheter for endoscopic use which documents the drug accumulated in the target tissues and the light penetration into the target tissues. The catheter uses reflectance to specify the light penetration depth and uses reflectance- corrected fluorescence to document drug accumulation. The goal is to document the variation in drug and light received by patients who are administered the FDA-approved prescription.

  8. Asbestos penetration test system for clothing materials

    SciTech Connect

    Bradley, O.D.; Stampfer, J.F.; Sandoval, A.N.; Heath, C.A.; Cooper, M.H.

    1997-04-01

    For hazardous work such as asbestos abatement, there is a need to assess protective clothing fabrics and seam constructions to assure an adequate barrier against hazardous material. The penetration of aerosols through fabrics usually is measured by challenging fabric samples with an aerosol stream at a constant specified airflow. To produce the specified airflow, pressure differentials across the samples often are higher than exist in a work environment. This higher airflow results in higher aerosol velocities through the fabric and, possibly, measured penetration values not representative of those actually experienced in the field. The objective of the reported work was to develop a test method that does not require these higher airflows. The authors have designed and fabricated a new system that tests fabric samples under a low, constant, specified pressure differential across the samples. This differential is adjustable from tenths of a mm Water Gauge (hundredths of an in WG) to over 25-mm WG (1-in WG). The system operates at a pressure slightly lower than its surroundings. Although designed primarily for asbestos, the system is equally applicable to the testing of other aerosols by changing the aerosol generator and detector. Through simple modification of the sample holders, the test apparatus would be capable of evaluating seam and closure constructions.

  9. Foliar penetration enhanced by biosurfactant rhamnolipid.

    PubMed

    Liu, Haojing; Shao, Bing; Long, Xuwei; Yao, Yang; Meng, Qin

    2016-09-01

    With recent environmental and health concerns, biosurfactants have obtained increasing interest in replacing conventional surfactants for diverse applications. In agriculture, the use of surfactant in stimulating foliar uptake is mainly for wetting leaf surface, resisting deposition/evaporation, enhancing penetration across cuticular membrane (CM) and translocation. This paper aimed to address the improved foliar uptake by rhamnolipid (RL) in comparison with the currently used alkyl polyglucoside (APG). As found, compared with APG at 900mg/L (1×critical micellar concentration, CMC), RL at a much lower concentration of 50mg/L (1×CMC) showed much better wettability and surface activity, indicative of its high effectiveness as surfactants. Its performance on resistance to deposition and evaporation was at least as same as APG. Moreover, RL could significantly improve the penetration of herbicide glyphosate and other two small water-soluble molecules (phenol red and Fe(2+)) across CM at an equivalent efficiency as APG at 1×CMC. Finally, the greatly enhanced herbicidal actitivity of glyphosate on greenhouse plants confirmed that RL and APG could both enhance the foliar uptake including translocation. Overall, RL should be more applicable than APG in agriculture due to its more promising properties on health/environmental friendliness. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Penetration of projectiles into granular targets.

    PubMed

    Ruiz-Suárez, J C

    2013-06-01

    Energetic collisions of subatomic particles with fixed or moving targets have been very valuable to penetrate into the mysteries of nature. But the mysteries are quite intriguing when projectiles and targets are macroscopically immense. We know that countless debris wandering in space impacted (and still do) large asteroids, moons and planets; and that millions of craters on their surfaces are traces of such collisions. By classifying and studying the morphology of such craters, geologists and astrophysicists obtain important clues to understand the origin and evolution of the Solar System. This review surveys knowledge about crater phenomena in the planetary science context, avoiding detailed descriptions already found in excellent papers on the subject. Then, it examines the most important results reported in the literature related to impact and penetration phenomena in granular targets obtained by doing simple experiments. The main goal is to discern whether both schools, one that takes into account the right ingredients (planetary bodies and very high energies) but cannot physically reproduce the collisions, and the other that easily carries out the collisions but uses laboratory ingredients (small projectiles and low energies), can arrive at a synergistic intersection point.

  11. Simulation of Hypervelocity Penetration in Limestone

    SciTech Connect

    Antoun, T; Glenn, L; Walton, O; Goldstein, P; Lomov, I; Liu, B

    2005-05-31

    A parameter study was performed to examine the (shock) damage obtained with long-rod and spherical mono-material penetrators impacting two varieties of limestone. In all cases, the impacts were assumed to be normal to the plane of the rock and at zero angle of attack (in the case of the rods). Impact velocities ranged to 15 km/s but most calculations were performed at 4 and 6 km/s and the penetrator mass was fixed at 1000 kg. For unlined underground structures, incipient damage was defined to occur when the peak stress, {sigma}{sub pk}, exceeds 1 kb (100 MPa) and the applied impulse per unit area, I{sub pk}, exceeds 1 ktap (1 kb-{micro}s). Severe damage was assumed to occur when {sigma}{sub pk} exceeds 1 kb and I{sub pk} exceeds 1000 ktaps. Using the latter definition it was found that severe damage in hard, non-porous limestone with spherical impactors extended to a depth of 9 m on-axis for an impact velocity of 4 km/s and 12 m at 6 km/s. Cylinders with length-to-diameter (L/D) ratio of 8.75 achieved depth to severe damage of 23 m and 40 m, respectively under the same conditions. For a limestone medium with 2% initial gas porosity, the latter numbers were reduced to 12 m and 18 m.

  12. Penetrated arrow shot injury in anterior neck.

    PubMed

    Aremu, Shuaib K; Dike, Benjamin

    2011-03-01

    Although gunshot injuries are the most common penetrating anterior neck injuries in the developed world, this finding is not the case in the developing world, where knives, spears, arrows, and machetes are the preferred weapons, particularly in tribal societies. To present the case report of a patient with arrow shot injury to the anterior neck. A 48 year old cattle rearer in a village in northern part of Nigeria presented with 3 hr history of an arrow shot in anterior part of the neck which he sustained the while trying to prevent some armed robbers from stealing his cow. There was scanty bleeding from the site with the arrow in-situ sealing the wound. The entrance point of the arrow, about 1 cm in diameter, was just at the anterior border of the right sternocleidomastoid muscle; about 4 cm above the medial end of the right clavicle. There was a small skin bruise with slight swelling and tenderness around the opening but no active bleeding and no crepitus. Penetrating neck trauma from arrow shot may lead to potentially life-threatening injuries. A prompt diagnosis, a systematic treatment protocol, and an experienced trauma team are necessary to prevent a potential catastroph.

  13. High Penetration Photovoltaic Case Study Report

    SciTech Connect

    Bank, J.; Mather, B.; Keller, J.; Coddington, M.

    2013-01-01

    Technical concerns with integrating higher penetrations of photovoltaic (PV) systems include grid stability, voltage regulation, power quality (voltage rise, sags, flicker, and frequency fluctuations), and protection and coordination. The current utility grid was designed to accommodate power flows from the central generation source to the transmission system and eventually to the distribution feeders. At the distribution level, the system was designed to carry power from the substation toward the load. Renewable distributed generation, particularly solar PV, provides power at the distribution level challenging this classical paradigm. As these resources become more commonplace the nature of the distribution network and its operation is changing to handle power flow in both directions. This report is focused on large PV installations in which penetration is significantly greater than 15% of maximum daytime feeder load. These case studies are intended to demonstrate success stories with integration of large PV plants at the distribution level as well as some of the solutions used by the utility to ensure safe, reliable operation of both the PV system and the distribution network.

  14. Penetration of projectiles into granular targets

    NASA Astrophysics Data System (ADS)

    Ruiz-Suárez, J. C.

    2013-06-01

    Energetic collisions of subatomic particles with fixed or moving targets have been very valuable to penetrate into the mysteries of nature. But the mysteries are quite intriguing when projectiles and targets are macroscopically immense. We know that countless debris wandering in space impacted (and still do) large asteroids, moons and planets; and that millions of craters on their surfaces are traces of such collisions. By classifying and studying the morphology of such craters, geologists and astrophysicists obtain important clues to understand the origin and evolution of the Solar System. This review surveys knowledge about crater phenomena in the planetary science context, avoiding detailed descriptions already found in excellent papers on the subject. Then, it examines the most important results reported in the literature related to impact and penetration phenomena in granular targets obtained by doing simple experiments. The main goal is to discern whether both schools, one that takes into account the right ingredients (planetary bodies and very high energies) but cannot physically reproduce the collisions, and the other that easily carries out the collisions but uses laboratory ingredients (small projectiles and low energies), can arrive at a synergistic intersection point.

  15. Factors affecting penetrating captive bolt gun performance.

    PubMed

    Gibson, Troy J; Mason, Charles W; Spence, Jade Y; Barker, Heather; Gregory, Neville G

    2015-01-01

    Captive bolt stunning is used for rendering livestock insensible at slaughter. The mechanical factors relating to performance of 6 penetrating captive bolt gun (CBG) models were examined. The Matador Super Sécurit 3000 and the .25 Cash Euro Stunner had the highest kinetic energy values (443 J and 412 J, respectively) of the CBGs tested. Ninety percent (27/30) of CBGs held at a government gun repository (United Kingdom) were found to have performed at a normal standard for the model, while 53% (10/19) of commercial contractor CBGs tested were found to underperform for the gun model. When the .22 Cash Special was fired 500 times at 4 shots per min, the gun reached a peak temperature of 88.8°C after 2.05 hr. Repeat firing during extended periods significantly reduced the performance of the CBG. When deciding on the appropriate CBG/cartridge combination, the kinetic energy delivered to the head of the nonhuman animal, bolt penetration depth, and species/animal type must be considered. It is recommended that CBGs are routinely checked for wear to the bolt and barrel if they are repeatedly fired in a session.

  16. EFFECTS OF PENETRATIVE CONVECTION ON SOLAR DYNAMO

    SciTech Connect

    Masada, Youhei; Yamada, Kohei; Kageyama, Akira

    2013-11-20

    Spherical solar dynamo simulations are performed. A self-consistent, fully compressible magnetohydrodynamic system with a stably stratified layer below the convective envelope is numerically solved with a newly developed simulation code based on the Yin-Yang grid. The effects of penetrative convection are studied by comparing two models with and without the stable layer. The differential rotation profile in both models is reasonably solar-like with equatorial acceleration. When considering the penetrative convection, a tachocline-like shear layer is developed and maintained beneath the convection zone without assuming any forcing. While the turbulent magnetic field becomes predominant in the region where the convective motion is vigorous, mean-field components are preferentially organized in the region where the convective motion is less vigorous. Particularly in the stable layer, the strong, large-scale field with a dipole symmetry is spontaneously built up. The polarity reversal of the mean-field component takes place globally and synchronously throughout the system regardless of the presence of the stable layer. Our results suggest that the stably stratified layer is a key component for organizing the large-scale strong magnetic field, but is not essential for the polarity reversal.

  17. Ground-penetrating SAR: a strawman design

    NASA Astrophysics Data System (ADS)

    Gough, Peter T.; Hunt, Bobby R.

    1997-12-01

    There is a great deal of interest in subsurface imaging of the earth's surface using SAR; however, most current and planned satellite SARs are not optimized for this purpose. Here we present a set of specifications for an earth-orbit satellite SAR specifically designed for subsurface imaging. In the design of a satellite borne ground penetrating SAR, there are several competing requirements all of which have to be balanced in a cost/benefit analysis. Here we look at two possible scenarios both using a 300 MHz carrier with one in a sun-synchronous orbit at 700 km altitude, the other at 250 km. Some of the critical parameters that are considered for this ground-penetrating SAR (n addition to those for a normal satellite SAR) include the wavelength, the dimensions of the real antenna, ground incidence angles and power density as well as polarization diversity. The intention here is to propose a system designed to maximize the subsurface back-scatter as a proportion of the total returned echo.

  18. Ground penetrating radar for asparagus detection

    NASA Astrophysics Data System (ADS)

    Seyfried, Daniel; Schoebel, Joerg

    2016-03-01

    Ground penetrating radar is a promising technique for detection of buried objects. Recently, radar has more and more been identified to provide benefits for a plurality of applications, where it can increase efficiency of operation. One of these fields is the industrial automatic harvesting process of asparagus, which is performed so far by cutting the soil ridge at a certain height including all the asparagus spears and subsequently sieving the latter out of the soil. However, the height where the soil is cut is a critical parameter, since a wrong value leads to either damage of the roots of the asparagus plants or to a reduced crop yield as a consequence of too much biomass remaining in the soil. In this paper we present a new approach which utilizes ground penetrating radar for non-invasive sensing in order to obtain information on the optimal height for cutting the soil. Hence, asparagus spears of maximal length can be obtained, while keeping the roots at the same time undamaged. We describe our radar system as well as the subsequent digital signal processing steps utilized for extracting the information required from the recorded radar data, which then can be fed into some harvesting unit for setting up the optimal cutting height.

  19. [Videothoracospy in thoracic trauma and penetrating injuries].

    PubMed

    Lang-Lazdunski, L; Chapuis, O; Pons, F; Jancovici, R

    2003-03-01

    Videothoracoscopy represents a valid and useful approach in some patients with blunt chest trauma or penetrating thoracic injury. This technique has been validated for the treatment of clotted hemothorax or posttraumatic empyema, traumatic chylothorax, traumatic pneumothorax, in patients with hemodynamic stability. Moreover, it is probably the most reliable technique for the diagnosis of diaphragmatic injury. It is also useful for the extraction of intrathoracic projectiles and foreign bodies. This technique might be useful in hemodynamically stable patients with continued bleeding or for the exploration of patients with penetrating injury in the cardiac area, although straightforward data are lacking to confirm those indications. Thoracotomy or median sternotomy remain indicated in patients with hemodynamic instability or those that cannot tolerate lateral decubitus position or one-lung ventilation. Performing video-surgery in the trauma setting require expertise in both video-assisted thoracic surgery and chest trauma management. The contra-indications to videothoracoscopy and indications for converting the procedure to an open thoracotomy should be perfectly known by surgeons performing video-assisted thoracic surgery in the trauma setting. Conversion to thoracotomy or median sternotomy should be performed without delay whenever needed to avoid blood loss and achieve an adequate procedure.

  20. Penetration enhancer-containing vesicles: composition dependence of structural features and skin penetration ability.

    PubMed

    Manconi, M; Caddeo, C; Sinico, C; Valenti, D; Mostallino, M C; Lampis, S; Monduzzi, M; Fadda, A M

    2012-10-01

    In this work, we focused on how composition and preparation method of vesicles might affect their morphological features and delivery performances. Penetration Enhancer-containing Vesicles, PEVs, vesicles containing a water miscible penetration enhancer (Transcutol® P; 10%, 20%, 30% v/v) and encapsulating diclofenac sodium, were formulated and compared with conventional liposomes. A cheap and unpurified commercial mixture of phospholipids, fatty acids, and triglycerides (Phospholipon® 50) was used, and the effects of this heterogeneous composition (along with the presence or absence of transcutol and the production method) on vesicle morphology, size, surface charge, drug loading, and stability were investigated. The variations in vesicle structure, bilayer thickness, and number of lamellae were assessed by TEM and Small and Wide Angle X-ray Scattering, which also proved the liquid state of the vesicular bilayer. Further, vesicles were evaluated for ex vivo (trans)dermal delivery, and their mode of action was studied performing a pre-treatment test and confocal laser scanning microscopy analyses. Results showed the formation of multi- and unilamellar vesicles that provided improved diclofenac delivery to pig skin, influenced by vesicle lipid composition and structure. Images of the qualitative CLSM analyses support the conclusion that PEVs enhance drug transport by penetrating intact the stratum corneum, thanks to a synergic effect of vesicles and penetration enhancer. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Adult Learning, Adult Teaching.

    ERIC Educational Resources Information Center

    Daines, John; And Others

    This book is designed to provide specific and practical suggestions for teachers and tutors of adult students. It is divided into two major parts. Part 1, which is devoted to adult learning, includes information on the characteristics of adult learners, their expectations and motivation, and issues related to equal opportunities and access. Part 2…

  2. Da Vinci Xi Robot-Assisted Penetrating Keratoplasty.

    PubMed

    Chammas, Jimmy; Sauer, Arnaud; Pizzuto, Joëlle; Pouthier, Fabienne; Gaucher, David; Marescaux, Jacques; Mutter, Didier; Bourcier, Tristan

    2017-06-01

    This study aims (1) to investigate the feasibility of robot-assisted penetrating keratoplasty (PK) using the new Da Vinci Xi Surgical System and (2) to report what we believe to be the first use of this system in experimental eye surgery. Robot-assisted PK procedures were performed on human corneal transplants using the Da Vinci Xi Surgical System. After an 8-mm corneal trephination, four interrupted sutures and one 10.0 monofilament running suture were made. For each procedure, duration and successful completion of the surgery as well as any unexpected events were assessed. The depth of the corneal sutures was checked postoperatively using spectral-domain optical coherence tomography (SD-OCT). Robot-assisted PK was successfully performed on 12 corneas. The Da Vinci Xi Surgical System provided the necessary dexterity to perform the different steps of surgery. The mean duration of the procedures was 43.4 ± 8.9 minutes (range: 28.5-61.1 minutes). There were no unexpected intraoperative events. SD-OCT confirmed that the sutures were placed at the appropriate depth. We confirm the feasibility of robot-assisted PK with the new Da Vinci Surgical System and report the first use of the Xi model in experimental eye surgery. Operative time of robot-assisted PK surgery is now close to that of conventional manual surgery due to both improvement of the optical system and the presence of microsurgical instruments. Experimentations will allow the advantages of robot-assisted microsurgery to be identified while underlining the improvements and innovations necessary for clinical use.

  3. Experimental verification of the effects of optical wavelength on the amplitude of laser generated ultrasound in polymer-matrix composites.

    PubMed

    Dubois, M; Lorraine, P W; Filkins, R J; Drake, T E; Yawn, K R; Chuang, S Y

    2002-05-01

    Laser ultrasound is now integrated into the manufacturing process of some of the most modern aircraft for the inspection of composite parts. Unfortunately, for some material and process combinations, laser-ultrasound suffers from a lack of sensitivity. In laser-ultrasound generation, optical penetration depth plays a very important role. It was shown that changing the generation wavelength from the 10.6 microm of the CO2 laser to the 3-4 microm range can significantly improve generation efficiency. In this paper, ultrasonic displacements are compared to measurements of optical penetration depth in different polymer-matrix composites. Ultrasonic waves were generated using an optical parametric oscillator operating in the 3.0-3.5 microm band and optical penetration depth spectra were evaluated using quantitative photoacoustic spectroscopy. The relative amplitudes of the generated ultrasonic waves track closely the optical penetration depth spectra. These results experimentally demonstrate the importance of optical penetration in the laser-ultrasound generation process.

  4. Ultraviolet (UVB and UVA) photoprotector activity and percutaneous penetration of extracts obtained from Arrabidaea chica.

    PubMed

    Siraichi, Jackeline T G; Pedrochi, Franciana; Natali, Maria R M; Ueda-Nakamura, Tânia; Filho, Benedito P Dias; Bento, Antonio C; Baesso, Mauro L; Nakamura, Celso V

    2013-10-01

    The aim of this work is to investigate the photoprotection activity and toxicity level of formulations containing the extract and its fractions obtained from leaves of Arrabidaea chica. The ex vivo percutaneous penetration of the extract was evaluated using the photoacoustic spectroscopy technique. The formulation presented optical absorption in the ultraviolet region, including UVA and UVB. This formulation was obtained without adding inorganic UV filters, as is frequently used in commercial sunscreens. The results showed a penetration rate similar to those of commercial sunscreens with its presence on the skin surface at least 180 min after the application. This formulation presented no toxic effects evaluated using hematological, biochemical, and histological assays. The results suggest that the formulation from the leaves of A. chica provides substantial protection against UVA + UVB radiation with a possible advantage of being natural and free of inorganic compounds compared with the majority of available commercial sunscreens.

  5. Measurements of laser-induced plasma temperature field in deep penetration laser welding

    NASA Astrophysics Data System (ADS)

    Chen, Genyu; Zhang, Mingjun; Zhao, Zhi; Zhang, Yi; Li, Shichun

    2013-02-01

    Laser-induced plasma in deep penetration laser welding is located inside or outside the keyhole, namely, keyhole plasma or plasma plume, respectively. The emergence of laser-induced plasma in laser welding reveals important information of the welding technological process. Generally, electron temperature and electron density are two important characteristic parameters of plasma. In this paper, spectroscopic measurements of electron temperature and electron density of the keyhole plasma and plasma plume in deep penetration laser welding conditions were carried out. To receive spectra from several points separately and simultaneously, an Optical Multi-channel Analyser (OMA) was developed. On the assumption that the plasma was in local thermal equilibrium, the temperature was calculated with the spectral relative intensity method. The spectra collected were processed with Abel inversion method to obtain the temperature fields of keyhole plasma and plasma plume.

  6. Imaging penetrating radiation through ion photon emission microscopy

    NASA Astrophysics Data System (ADS)

    Hattar, Khalid; Branson, Janelle V.; Powell, Cody J.; Vizkelethy, Gyorgy; Rossi, Paolo; Doyle, Barney L.

    2010-08-01

    The ion photon emission microscope (IPEM), a new radiation effects microscope for the imaging of single event effects from penetrating radiation, is being developed at Sandia National Laboratories and implemented on the 88" cyclotron at Lawrence Berkeley National Laboratories. The microscope is designed to permit the direct correlation between the locations of high-energy heavy-ion strikes and single event effects in microelectronic devices. The development of this microscope has required the production of a robust optical system that is compatible with the ion beam lines, design and assembly of a fast single photon sensitive measurement system to provide the necessary coincidence, and the development and testing of many scintillating films. A wide range of scintillating material for application to the ion photon emission microscope has been tested with few meeting the stringent radiation hardness, intensity, and photon lifetime requirements. The initial results of these luminescence studies and the current operation of the ion photon emission microscope will be presented. Finally, the planned development for future microscopes and ion luminescence testing chambers will be discussed.

  7. Penetration and Toxicity of Nanomaterials in Higher Plants

    PubMed Central

    Chichiriccò, Giuseppe; Poma, Anna

    2015-01-01

    Nanomaterials (NMs) comprise either inorganic particles consisting of metals, oxides, and salts that exist in nature and may be also produced in the laboratory, or organic particles originating only from the laboratory, having at least one dimension between 1 and 100 nm in size. According to shape, size, surface area, and charge, NMs have different mechanical, chemical, electrical, and optical properties that make them suitable for technological and biomedical applications and thus they are being increasingly produced and modified. Despite their beneficial potential, their use may be hazardous to health owing to the capacity to enter the animal and plant body and interact with cells. Studies on NMs involve technologists, biologists, physicists, chemists, and ecologists, so there are numerous reports that are significantly raising the level of knowledge, especially in the field of nanotechnology; however, many aspects concerning nanobiology remain undiscovered, including the interactions with plant biomolecules. In this review we examine current knowledge on the ways in which NMs penetrate plant organs and interact with cells, with the aim of shedding light on the reactivity of NMs and toxicity to plants. These points are discussed critically to adjust the balance with regard to the risk to the health of the plants as well as providing some suggestions for new studies on this topic. PMID:28347040

  8. Simulation and measurement of transcranial near infrared light penetration

    NASA Astrophysics Data System (ADS)

    Yue, Lan; Monge, Manuel; Ozgur, Mehmet H.; Murphy, Kevin; Louie, Stan; Miller, Carol A.; Emami, Azita; Humayun, Mark S.

    2015-03-01

    We are studying the transmission of LED array-emitted near-infrared (NIR) light through human tissues. Herein, we simulated and measured transcranial NIR penetration in highly scattering human head tissues. Using finite element analysis, we simulated photon diffusion in a multilayered 3D human head model that consists of scalp, skull, cerebral spinal fluid, gray matter and white matter. The optical properties of each layer, namely scattering and absorption coefficient, correspond to the 850 nm NIR light. The geometry of the model is minimally modified from the IEEE standard and the multiple LED emitters in an array were evenly distributed on the scalp. Our results show that photon distribution produced by the array exhibits little variation at similar brain depth, suggesting that due to strong scattering effects of the tissues, discrete spatial arrangements of LED emitters in an array has the potential to create a quasi-radially symmetrical illumination field. Measurements on cadaveric human head tissues excised from occipital, parietal, frontal and temporal regions show that illumination with an 850 nm LED emitter rendered a photon flux that closely follows simulation results. In addition, prolonged illumination of LED emitted NIR showed minimal thermal effects on the brain.

  9. Improving Outcomes Following Penetrating Colon Wounds

    PubMed Central

    Miller, Preston R.; Fabian, Timothy C.; Croce, Martin A.; Magnotti, Louis J.; Elizabeth Pritchard, F.; Minard, Gayle; Stewart, Ronald M.

    2002-01-01

    Introduction During World War II, failure to treat penetrating colon injuries with diversion could result in court martial. Based on this wartime experience, colostomy for civilian colon wounds became the standard of care for the next 4 decades. Previous work from our institution demonstrated that primary repair was the optimal management for nondestructive colon wounds. Optimal management of destructive wounds requiring resection remains controversial. To address this issue, we performed a study that demonstrated risk factors (pre or intraoperative transfusion requirement of more than 6 units of packed red blood cells, significant comorbid diseases) that were associated with a suture line failure rate of 14%, and of whom 33% died. Based on these outcomes, a clinical pathway for management of destructive colon wounds was developed. The results of the implementation of this pathway are the focus of this report. Methods Patients with penetrating colon injury were identified from the registry of a level I trauma center over a 5-year period. Records were reviewed for demographics, injury characteristics, and outcome. Patients with nondestructive injuries underwent primary repair. Patients with destructive wounds but no comorbidities or large transfusion requirement underwent resection and anastomosis, while patients with destructive wounds and significant medical illness or transfusion requirements of more than 6 units/blood received end colostomy. The current patients (CP) were compared to the previous study (PS) to determine the impact of the clinical pathway. Outcomes examined included colon related mortality and morbidity (suture line leak and abscess). Results Over a 5.5-year period, 231 patients had penetrating colon wounds. 209 survived more 24 hours and comprise the study population. Primary repair was performed on 153 (73%) patients, and 56 patients had destructive injuries (27%). Of these, 40 (71%) had resection and anastomosis and 16 (29%) had diversion

  10. Modeling of Oblique Penetration into Geologic Targets Using Cavity Expansion Penetrator Loading with Target free-Surface Effects

    SciTech Connect

    Jung, Joe; Longcope, Donald B.; Tabbara, Mazen R.

    1999-05-03

    A procedure has been developed to represent the loading on a penetrator and its motion during oblique penetration into geologic media. The penetrator is modeled with the explicit dynamics, finite element computer program PRONTO 3D and the coupled pressure on the penetrator is given in a new loading option based on a separate cavity expansion (CE) solution that accounts for the pressure-reduction from a nearby target free surface. The free-surface influ- ence distance is selected in a predictive manner by considering the pressure to expand a spherical cavity in a finite radius sphere of the target material. The CE/PRONTO 3D procedure allows a detailed description of the penetrator for predicting shock environments or structural failure dur- ing the entire penetration event and is sufficiently rapid to be used in design optimization. It has been evaluated by comparing its results with data from two field tests of a full-scale penetrator into frozen soil at an impact angles of 49.6 and 52.5 degrees from the horizontal. The measured penetrator rotations were 24 and 22 degrees, respectively. In the simulation, the rotation was21 degrees and predominately resulted from the pressure reduction of the free surface. Good agree- ment was also found for the penetration depth and axial and lateral acceleration at two locations in the penetrator.

  11. The full penetration hole as a stochastic process: controlling penetration depth in keyhole laser-welding processes

    NASA Astrophysics Data System (ADS)

    Blug, A.; Abt, F.; Nicolosi, L.; Heider, A.; Weber, R.; Carl, D.; Höfler, H.; Tetzlaff, R.

    2012-07-01

    Although laser-welding processes are frequently used in industrial production the quality control of these processes is not satisfactory yet. Until recently, the "full penetration hole" was presumed as an image feature which appears when the keyhole opens at the bottom of the work piece. Therefore it was used as an indicator for full penetration only. We used a novel camera based on "cellular neural networks" which enables measurements at frame rates up to 14 kHz. The results show that the occurrence of the full penetration hole can be described as a stochastic process. The probability to observe it increases near the full penetration state. In overlap joints, a very similar image feature appears when the penetration depth reaches the gap between the sheets. This stochastic process is exploited by a closed-loop system which controls penetration depth near the bottom of the work piece ("full penetration") or near the gap in overlap joints ("partial penetration"). It guides the welding process at the minimum laser power necessary for the required penetration depth. As a result, defects like spatters are reduced considerably and the penetration depth becomes independent of process drifts such as feeding rate or pollution on protection glasses.

  12. Optic neuritis

    MedlinePlus

    Retro-bulbar neuritis; Multiple sclerosis - optic neuritis; Optic nerve - optic neuritis ... The exact cause of optic neuritis is unknown. The optic nerve carries visual information from your eye to the brain. The nerve can swell when ...

  13. Stability of Full Penetration, Flat Position Weld Pools

    NASA Technical Reports Server (NTRS)

    Nunes, Arthur C., Jr.; Coan, Al. B.

    1999-01-01

    The dynamics of the dropthrough distance of a full penetration, flat position weld pool is described. Close to incipient root side penetration the dropthrough is metastable, so that a small drop in power can cause a loss of penetration if not followed soon enough by a compensating rise in power. The SPA (Soft Plasma Arc) process with higher pressure on top of the weld pool loses penetration more quickly than the GTA (Gas Tungsten Arc) process. 2195 aluminum-lithium alloy with a lower surface tension loses penetration more quickly than 2219 aluminum alloy. An instance of loss of penetration of a SPA weld in 2195 aluminum-lithium alloy is discussed in the light of the model.

  14. Automatic control of oscillatory penetration apparatus

    DOEpatents

    Lucon, Peter A

    2015-01-06

    A system and method for controlling an oscillatory penetration apparatus. An embodiment is a system and method for controlling a sonic drill having a displacement and an operating range and operating at a phase difference, said sonic drill comprising a push-pull piston and eccentrics, said method comprising: operating the push-pull piston at an initial push-pull force while the eccentrics are operated at a plurality of different operating frequencies within the operating range of the sonic drill and measuring the displacement at each operating frequency; determining an efficient operating frequency for the material being drilled and operating the eccentrics at said efficient operating frequency; determining the phase difference at which the sonic drill is operating; and if the phase difference is not substantially equal to minus ninety degrees, operating the push-pull piston at another push-pull force.

  15. First principles cable braid electromagnetic penetration model

    SciTech Connect

    Warne, Larry Kevin; Langston, William L.; Basilio, Lorena I.; Johnson, William A.

    2016-01-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also set up in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multi-poles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinite periodic planar geometry. Furthermore, this is used to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.

  16. Fluorescent Penetrant INSPECTION—CLEANING Study Update

    NASA Astrophysics Data System (ADS)

    Eisenmann, D.; Brasche, L.

    2009-03-01

    Fluorescent penetrant inspection (FPI) is widely used in the aviation industry and other industries for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. There is variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. Before the FPI process begins, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. From the first three phases of this project it has been found that a hot water rinse can aid in the detection process when using this nondestructive method.

  17. Pharmacokinetics and inflammatory fluid penetration of sparfloxacin.

    PubMed Central

    Johnson, J H; Cooper, M A; Andrews, J M; Wise, R

    1992-01-01

    A single 400-mg oral dose of sparfloxacin was given to each of six healthy male volunteers, and the concentrations of the drug were measured in plasma, cantharides-induced inflammatory fluid, and urine over the subsequent 52 h. The mean peak concentration in plasma of 1.6 micrograms/ml was attained at a mean time of 2.7 h postdose. The mean peak concentration in inflammatory fluid of 1.3 micrograms/ml was attained at a mean time of 5 h postdose. The mean elimination half-life in plasma was 17.6 h, and that in inflammatory fluid was 19.7 h. The overall penetration into inflammatory fluid was 117%. Urinary recovery within the first 52 h postdose was 8.8% of the administered dose. Our results indicate that a once-daily dosage of sparfloxacin should be adequate to treat systemic infections caused by most common bacterial pathogens. PMID:1336947

  18. The penetration of ceftazidime into extravascular fluid.

    PubMed

    Ryan, D M; Mason, U; Harding, S M

    1981-09-01

    Ceftazidime achieved high concentrations in extravascular fluid following intravenal or intramuscular administration to healthy male volunteers. Subcutaneous fluid was sampled using the implanted cotton thread technique. The concentration/time curves of ceftazidime in subcutaneous fluid, after a short distributive phase, were similar in profile to concurrent serum concentrations. The degree of penetration as determined by ratio of the area under curve for subcutaneous fluid levels to the area under curve for the serum levels was 54%. There is evidence from experiments in animals that antibiotic concentration/time profiles in the subcutaneous compartment reflect levels found in rapidly equilibriating tissue fluids or well perfused tissues. It is therefore concluded that ceftazidime will achieve therapeutically useful levels in a wide range of tissues and tissue fluids in man in exess of the MIC90 for Pseudomonas aeruginosa, Staphylococcus aureus and members of the Enterobacteriaceae.

  19. Wide band stepped frequency ground penetrating radar

    DOEpatents

    Bashforth, Michael B.; Gardner, Duane; Patrick, Douglas; Lewallen, Tricia A.; Nammath, Sharyn R.; Painter, Kelly D.; Vadnais, Kenneth G.

    1996-01-01

    A wide band ground penetrating radar system (10) embodying a method wherein a series of radio frequency signals (60) is produced by a single radio frequency source (16) and provided to a transmit antenna (26) for transmission to a target (54) and reflection therefrom to a receive antenna (28). A phase modulator (18) modulates those portion of the radio frequency signals (62) to be transmitted and the reflected modulated signal (62) is combined in a mixer (34) with the original radio frequency signal (60) to produce a resultant signal (53) which is demodulated to produce a series of direct current voltage signals (66) the envelope of which forms a cosine wave shaped plot (68) which is processed by a Fast Fourier Transform unit 44 into frequency domain data (70) wherein the position of a preponderant frequency is indicative of distance to the target (54) and magnitude is indicative of the signature of the target (54).

  20. Wide band stepped frequency ground penetrating radar

    DOEpatents

    Bashforth, M.B.; Gardner, D.; Patrick, D.; Lewallen, T.A.; Nammath, S.R.; Painter, K.D.; Vadnais, K.G.

    1996-03-12

    A wide band ground penetrating radar system is described embodying a method wherein a series of radio frequency signals is produced by a single radio frequency source and provided to a transmit antenna for transmission to a target and reflection therefrom to a receive antenna. A phase modulator modulates those portions of the radio frequency signals to be transmitted and the reflected modulated signal is combined in a mixer with the original radio frequency signal to produce a resultant signal which is demodulated to produce a series of direct current voltage signals, the envelope of which forms a cosine wave shaped plot which is processed by a Fast Fourier Transform Unit 44 into frequency domain data wherein the position of a preponderant frequency is indicative of distance to the target and magnitude is indicative of the signature of the target. 6 figs.

  1. First principles cable braid electromagnetic penetration model

    DOE PAGES

    Warne, Larry Kevin; Langston, William L.; Basilio, Lorena I.; ...

    2016-01-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also set up in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multi-poles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinitemore » periodic planar geometry. Furthermore, this is used to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.« less

  2. Penetration of surfactant solutions into hydrophobic capillaries.

    PubMed

    Bain, Colin D

    2005-08-21

    The initial rise velocity of surfactant solutions in hydrophobic capillaries is independent of time (F. Tiberg, B. Zhmud, K. Hallstensson and M. von Bahr, Phys. Chem. Chem. Phys., 2000, 2, 5189). By analogy with the hydrodynamics of an overflowing cylinder, we present a steady-state solution for capillary penetration in which the velocity is determined by the adsorption kinetics at the air-water interface. Good agreement between the model predictions and experimental data of Tiberg and coworkers is obtained for the non-ionic surfactant C10E6 under the assumption of diffusion-controlled adsorption. The longer chain homologue, C14E6, shows evidence of kinetic barriers to adsorption.

  3. Processing depleted uranium quad alloy penetrator rods

    SciTech Connect

    Bokan, S.L.

    1987-02-19

    Two depleted uranium (DU) quad alloys were cast, extruded and rolled to produce penetrator rods. The two alloy combinations were (1) 1 wt % molybdenum (Mo), 1 wt % niobium (Nb), and 0.75 wt % titanium (Ti); and (2) 1 wt % tantalum (Ta), 1 wt % Nb, and 0.75 wt % Ti. This report covers the processing and results with limited metallographic information available. The two alloys were each vacuum induction melted (VIM) into an 8-in. log, extruded into a 3-in. log, then cut into 4 logs and extruded at 4 different temperatures into 0.8-in. bars. From the 8 conditions (2 alloys, 4 extrusion temperatures each), 10 to 13 16-in. rods were cut for rolling and swaging. Due to cracking problems, the final processing changed from rolling and swaging to limited rolling and heat treating. The contracted work was completed with the delivery of 88 rods to Dr. Zabielski. 28 figs.

  4. Estimation of penetrance from twin data.

    PubMed

    Praxedes, L A; Otto, P A

    2000-12-01

    A simple method for estimating the gene frequency p and the penetrance value K from data on polymorphic monogenic characteristics on monozygotic twin pairs is presented. In spite of the method here presented having limited value because the results it yields cannot be evaluated on their own, the estimates of p and K it provides can be indirectly tested by comparing them to the ones obtained in familial aggregates through classical segregation analysis or by using the latter to calculate the expected proportions of dominant-dominant, dominant-recessive and recessive-recessive monozygotic twin pairs. When the method is applied to data on tongue-rolling ability published in the literature, a good agreement is observed between twin and familial estimates, thus indicating that the method is reliable and that it can be used as an ancillary way of corroborating or otherwise evidence of monogenic autosomal dominant mechanism inferred from the analysis of familial data.

  5. Cell Penetrating Peptides and Cationic Antibacterial Peptides

    PubMed Central

    Rodriguez Plaza, Jonathan G.; Morales-Nava, Rosmarbel; Diener, Christian; Schreiber, Gabriele; Gonzalez, Zyanya D.; Lara Ortiz, Maria Teresa; Ortega Blake, Ivan; Pantoja, Omar; Volkmer, Rudolf; Klipp, Edda; Herrmann, Andreas; Del Rio, Gabriel

    2014-01-01

    Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) because it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs. PMID:24706763

  6. A nonparametric method for penetrance function estimation.

    PubMed

    Alarcon, F; Bonaïti-Pellié, C; Harari-Kermadec, H

    2009-01-01

    In diseases caused by a deleterious gene mutation, knowledge of age-specific cumulative risks is necessary for medical management of mutation carriers. When pedigrees are ascertained through at least one affected individual, ascertainment bias can be corrected by using a parametric method such as the Proband's phenotype Exclusion Likelihood, or PEL, that uses a survival analysis approach based on the Weibull model. This paper proposes a nonparametric method for penetrance function estimation that corrects for ascertainment on at least one affected: the Index Discarding EuclideAn Likelihood or IDEAL. IDEAL is compared with PEL, using family samples simulated from a Weibull distribution and under alternative models. We show that, under Weibull assumption and asymptotic conditions, IDEAL and PEL both provide unbiased risk estimates. However, when the true risk function deviates from a Weibull distribution, we show that the PEL might provide biased estimates while IDEAL remains unbiased.

  7. Obstacle penetrating dynamic radar imaging system

    DOEpatents

    Romero, Carlos E.; Zumstein, James E.; Chang, John T.; Leach, Jr.. Richard R.

    2006-12-12

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  8. Penetration of chlorhexidine into human skin.

    PubMed

    Karpanen, T J; Worthington, T; Conway, B R; Hilton, A C; Elliott, T S J; Lambert, P A

    2008-10-01

    This study evaluated a model of skin permeation to determine the depth of delivery of chlorhexidine into full-thickness excised human skin following topical application of 2% (wt/vol) aqueous chlorhexidine digluconate. Skin permeation studies were performed on full-thickness human skin using Franz diffusion cells with exposure to chlorhexidine for 2 min, 30 min, and 24 h. The concentration of chlorhexidine extracted from skin sections was determined to a depth of 1,500 microm following serial sectioning of the skin using a microtome and analysis by high-performance liquid chromatography. Poor penetration of chlorhexidine into skin following 2-min and 30-min exposures to chlorhexidine was observed (0.157 +/- 0.047 and 0.077 +/- 0.015 microg/mg tissue within the top 100 microm), and levels of chlorhexidine were minimal at deeper skin depths (less than 0.002 microg/mg tissue below 300 microm). After 24 h of exposure, there was more chlorhexidine within the upper 100-microm sections (7.88 +/- 1.37 microg/mg tissue); however, the levels remained low (less than 1 microg/mg tissue) at depths below 300 microm. There was no detectable penetration through the full-thickness skin. The model presented in this study can be used to assess the permeation of antiseptic agents through various layers of skin in vitro. Aqueous chlorhexidine demonstrated poor permeation into the deeper layers of the skin, which may restrict the efficacy of skin antisepsis with this agent. This study lays the foundation for further research in adopting alternative strategies for enhanced skin antisepsis in clinical practice.

  9. Two-step LASIK after penetrating keratoplasty

    PubMed Central

    Kollias, Aris N; Schaumberger, Markus M; Kreutzer, Thomas C; Ulbig, Michael W; Lackerbauer, Carlo A

    2009-01-01

    Purpose: The point of interest of this retrospective case review is to study refractive changes caused by the hinged lamellar keratotomy and the refractive outcome after laser ablation in a second step within the scope of laser in situ keratomileusis (LASIK) in patients with penetrating keratoplasty. Methods: Data from eight patients obtained before lamellar keratotomy, before laser ablation, and three months later were evaluated. Keratotomies were performed with the Moria® LSK one and the Amadeus® 2 microkeratome, laser ablation was performed with the Schwind® Keratome I and the Wavelight® Allegretto WaveEyeQ. Results: Uncorrected visual acuity (UCVA) improved significantly from 1 [logMar] to 0.4 [logMar] at the last visit. Median gain of UCVA was 7.38 ± 2.96 Snellen lines. Best spectacle-corrected visual acuity did not change significantly. Preoperative manifest refraction spherical equivalent decreased from −4.02 ± 4.77 diopters (D) to −1.11 ± 2.45 D after laser ablation. Mean preoperative manifest astigmatism was −7.27 ± 3.65 D, after lamellar keratotomy −6.72 ± 3.68 D, and after laser ablation −2.08 ± 1.80 D. Manifest astigmatism did not change significantly after the keratotomy. Conclusions: Lamellar keratotomy causes biomechanical changes to the cornea. We favor a two-step LASIK in penetrating keratoplasty patients in order to improve precision and predictability of the refractive outcome. PMID:19898662

  10. Pathway Controlled Penetration (PcP)

    SciTech Connect

    Knight, Earl E.; Rougier, Esteban; Zubelewicz, Aleksander

    2012-08-29

    The technical approach employs advanced computational simulation tools to demonstrate how current assets can destroy RWK-RFI-12-0001's HDBT, a tunnel complex with two portals built into the base of a granite mountain. The granite over layer is assumed to be 60 meters thick over both portals and 80 meters over the facility's mission space. Key S&T is the completed development of a highly innovative viscoplastic fracture material model, 3D parallel gas-fracture capabilities into FDEM, and a stochastic handling of the material properties. Phase I - Develop and validate code simulation tools: (1) develop, incorporate and validate AZ-Frac material model for granite; and (2) Develop and incorporate gas-driven-fracture modeling into LANL's FDEM MUNROU code; (3) Develop and incorporate stochastic features into FDEM modeling. Phase II - Conduct PcP analysis on above HDBT: (1) Acquire HDBT design data, develop simulation model; and (2) Evaluate and select most promising defeat alternative. Phase III - Deliver code, train Service target analysts, and conduct simulations against real world HDBTs. PcP uses advanced computer simulations to enhance HDBT functional defeat efforts. Newly developed material models that account for fractural energy coupled with the finite discrete element methodology (FDEM) will provide targeting packages that will create penetration avenues for current or future lethality options. This novel computational approach requires full 3D geologic and structure characterization as well as significant high performance computing capabilities. The goal is to distinctively alter the targeting paradigm by leveraging critical DoD assets along with insitu geologic strata. In other words, assets will utilize underground rock structure to their benefit by creating rubbilization zones that will allow pathway controlled penetration.

  11. Novel cell-penetrating peptide targeting mitochondria.

    PubMed

    Cerrato, Carmine Pasquale; Pirisinu, Marco; Vlachos, Efstathios Nikolaos; Langel, Ülo

    2015-11-01

    Cell-penetrating peptides (CPPs) are short, nontoxic peptides with cationic and/or amphipathic properties able to cross the cellular membrane. CPPs are used for the delivery of a wide variety of cargoes, such as proteins, oligonucleotides, and therapeutic molecules. The aim of the present study was to synthesize unusually small novel CPPs targeting mitochondria based on the Szeto-Schiller peptide (SS-31) to influence intramitochondrial processes and to improve the biologic effects. All the peptides used were synthesized manually using 9-fluorenylmethyloxycarbonyl chemistry. In the first part of the study, HeLa 705, U87, and bEnd.3 cells were used as in vitro delivery model. Cells were incubated for 24 h at 37°C and 5% CO2 with different concentrations of our peptides. Cell proliferation assay was performed to evaluate cell viability. Biologic effects such as mitochondrial membrane potential and antioxidant activity were evaluated. H2O2 was used as positive control. Uptake studies were performed using peptides conjugated with 5(6)-carboxyfluorescein (FAM). Fluorescent microscopy was used to determine presence and localization of peptides into the cells. Isolated mitochondria from pretreated cells and mitochondria treated after isolation were used to confirm the targeting ability of the peptide. Uptake of FAM alone was used as negative control. Microscopy studies confirmed the ability of peptides to penetrate cell. Localization analysis showed increase in uptake by 35% compared with SS-31. Mitochondrial CPP 1 (mtCPP-1) had no effect on mitochondrial membrane potential and prevented reactive oxygen species formation in bEnd.3 cells by 2-fold compared with SS-31. No cytotoxicity was observed even at high concentration (100 µM). These data suggest that mtCPP-1 is a mitochondrial CPP and protect mitochondria from oxidative damage due to its own antioxidant activities. © FASEB.

  12. Socio-optics: optical knowledge applied in modeling social phenomena

    NASA Astrophysics Data System (ADS)

    Chisleag, Radu; Chisleag Losada, Ioana-Roxana

    2011-05-01

    The term "Socio-optics" (as a natural part of Socio-physics), is rather not found in literature or at Congresses. In Optics books, there are not made references to optical models applied to explain social phenomena, in spite of Optics relying on the duality particle-wave which seems convenient to model relationships among society and its members. The authors, who have developed a few models applied to explain social phenomena based on knowledge in Optics, along with a few other models applying, in Social Sciences, knowledge from other branches of Physics, give their own examples of such optical models, f. e., of relationships among social groups and their sub-groups, by using kowledge from partially coherent optical phenomena or to explain by tunnel effect, the apparently impossible penetration of social barriers by individuals. They consider that the term "Socio-optics" may come to life. There is mentioned the authors' expertise in stimulating Socio-optics approach by systematically asking students taken courses in Optics to find applications of the newly got Wave and Photon Optics knowledge, to model social and even everyday life phenomena, eventually engaging in such activities other possibly interested colleagues.

  13. Study of Comet Nucleus Gamma-Ray Spectrometer Penetration System

    NASA Technical Reports Server (NTRS)

    Adams, G. L.; Amundsen, R. J.; Beardsley, R. W.; Cash, R. H.; Clark, B. C.; Knight, T. C. D.; Martin, J. P.; Monti, P.; Outteridge, D. A.; Plaster, W. D.

    1986-01-01

    A penetrator system has been suggested as an approach for making in situ measurements of the composition and physical properties of the nucleus of a comet. This study has examined in detail the feasibility of implementing the penetrator concept. The penetrator system and mission designs have been developed and iterated in sufficient detail to provide a high level of confidence that the concept can be implemented within the constraints of the Mariner Mark 2 spacecraft.

  14. Cercarial Penetration Studies. Steps toward Chemoprophylaxis in Schistosomiasis.

    DTIC Science & Technology

    1986-10-15

    is increased at slightly acidic pH when compared to slightly alkaline pH. 3. The Effect of Ibuprofen and Esculetin on Cercarial Penetration...Transformation and Eicosanoid Production (in vitro). Ibuprofen has no effect on cercarial penetration or transformation rates at concentrations as high as lOm...Cercarial Eicosanoid Production. -7 3. The Effect of Ibuprofen and Esculetin on Cercarial Penetration, Trans- formation and Eicosanoid Production (in vitro

  15. Fire Resistance Testing of Bulkhead and Deck Penetrations. Phase 2

    DTIC Science & Technology

    1988-12-01

    thick steel plate. All sample 12 construction was representative of Class A-0 construction. The UL staff secured insulation ( rockwool batts) to the...designated side of the steel plates and penetrants for testing as Class A-60 deck assemblies. The rockwool batts complied with the Class A-60...insulated with rockwool batts and tested for a Class A-60 rating. This group consisted of one steel penetration, eight copper penetrations, four PVC

  16. Fast magnetic field penetration into low resistivity plasma

    NASA Astrophysics Data System (ADS)

    Fruchtman, Amnon

    2017-02-01

    Penetration of a magnetic field into plasma that is faster than resistive diffusion can be induced by the Hall electric field in a non-uniform plasma. This mechanism explained successfully the measured velocity of the magnetic field penetration into pulsed plasmas. Major related issues have not yet been resolved. Such is the theoretically predicted, but so far not verified experimentally, high magnetic energy dissipation, as well as the correlation between the directions of the density gradient and of the field penetration.

  17. Vehicle effects on human stratum corneum absorption and skin penetration.

    PubMed

    Zhang, Alissa; Jung, Eui-Chang; Zhu, Hanjiang; Zou, Ying; Hui, Xiaoying; Maibach, Howard

    2016-07-19

    This study evaluated the effects of three vehicles-ethanol (EtOH), isopropyl alcohol (IPA), and isopropyl myristate (IPM)-on stratum corneum (SC) absorption and diffusion of the [(14)C]-model compounds benzoic acid and butenafine hydrochloride to better understand the transport pathways of chemicals passing through and resident in SC. Following application of topical formulations to human dermatomed skin for 30 min, penetration flux was observed for 24 h post dosing, using an in vitro flow-through skin diffusion system. Skin absorption and penetration was compared to the chemical-SC (intact, delipidized, or SC lipid film) binding levels. A significant vehicle effect was observed for chemical skin penetration and SC absorption. IPA resulted in the greatest levels of intact SC/SC lipid absorption, skin penetration, and total skin absorption/penetration of benzoic acid, followed by IPM and EtOH, respectively. For intact SC absorption and total skin absorption/penetration of butenafine, the vehicle that demonstrated the highest level of sorption/penetration was EtOH, followed by IPA and IPM, respectively. The percent doses of butenafine that were absorbed in SC lipid film and penetrated through skin in 24 h were greatest for IPA, followed by EtOH and IPM, respectively. The vehicle effect was consistent between intact SC absorption and total chemical skin absorption and penetration, as well as SC lipid absorption and chemical penetration through skin, suggesting intercellular transport as a main pathway of skin penetration for model chemicals. These results suggest the potential to predict vehicle effects on skin permeability with simple SC absorption assays. As decontamination was applied 30 min after chemical exposure, significant vehicle effects on chemical SC partitioning and percutaneous penetration also suggest that skin decontamination efficiency is vehicle dependent, and an effective decontamination method should act on chemical solutes in the lipid domain.

  18. Superior cell penetration by a rigid and anisotropic synthetic protein.

    PubMed

    Nakayama, Norihisa; Hagiwara, Kyoji; Ito, Yoshihiro; Ijiro, Kuniharu; Osada, Yoshihito; Sano, Ken-Ichi

    2015-03-10

    Molecules with structural anisotropy and rigidity, such as asbestos, demonstrate high cell-penetrating activity but also high toxicity. Here we synthesize a biodegradable, rigid, and fibrous artificial protein, CCPC 140, as a potential vehicle for cellular delivery. CCPC 140 penetrated 100% of cells tested in vitro, even at a concentration of 3.1 nM-superior to previously reported cell-penetrating peptides. The effects of cell-strain-dependency and aspect ratio on the cell-penetrating activity of CCPC 140 were also investigated.

  19. Analysis of thermal performance of penetrated multi-layer insulation

    NASA Technical Reports Server (NTRS)

    Foster, Winfred A., Jr.; Jenkins, Rhonald M.; Yoo, Chai H.; Barrett, William E.

    1988-01-01

    Results of research performed for the purpose of studying the sensitivity of multi-layer insulation blanket performance caused by penetrations through the blanket are presented. The work described in this paper presents the experimental data obtained from thermal vacuum tests of various penetration geometries similar to those present on the Hubble Space Telescope. The data obtained from these tests is presented in terms of electrical power required sensitivity factors referenced to a multi-layer blanket without a penetration. The results of these experiments indicate that a significant increase in electrical power is required to overcome the radiation heat losses in the vicinity of the penetrations.

  20. Analysis of vertical projectile penetration in granular soils

    NASA Astrophysics Data System (ADS)

    Boguslavskii, Yu; Drabkin, S.; Salman, A.

    1996-03-01

    A model of vertical dynamic penetration of projectiles in granular soils was developed based on known experiments and the theory of dimensions. The depth of penetration is derived as a function of initial velocity and material properties. Velocity and acceleration are obtained as functions of time and depth of penetration. Under certain conditions two acceleration peaks are observed, an initial one due to dynamic and a second one due to static characteristics of penetration. Static properties of soils are derived using dynamic measurements. Numerical examples are provided. Theoretical and experimental results coincide reasonably well.

  1. Mechanism of Intergranular Penetration of Ga in an Aluminum Alloy

    NASA Astrophysics Data System (ADS)

    Ding, Boxiong; Hoagland, Richard

    1998-03-01

    The intergranular penetration rates of gallium in 7050-T74 aluminum alloy were examined at temperatures from 25C to 180C under stress free condition. The results provide an estimate of activation energy of the penetration process. The penetration of Ga is observed to occur along the grain boundary and also spread over the surface, but much more slowly. Experiments were also performed at 23C involving solid Ga. These results together with mechanism controlling the intergranular penetration of Ga in Al will be discussed. This work was supported by DARPA.

  2. Characterization of nuclear reactor containment penetrations. Preliminary report

    SciTech Connect

    Bump, T.R.; Seidensticker, R.W.; Shackelford, M.A.; Gambhir, V.K.; McLennan, G.L.

    1984-06-01

    This report summarizes the survey work conducted by Argonne National Laboratory on the design and details of major penetrations in 22 nuclear power plants. The survey includes all containment types and materials in current use. It also includes details of all types of penetrations (except for electrical penetration assemblies and valves) and the seals and gaskets used in them. The report provides a test matrix for testing major penetrations and for testing seals and gaskets in order to evaluate their leakage potential under severe accident conditions.

  3. Penetration depth at green wavelengths in turbid waters

    NASA Technical Reports Server (NTRS)

    Whitlock, C. H.; Witte, W. G.; Usry, J. W.; Gurganus, E. A.

    1978-01-01

    A laboratory and field measurement program was conducted to determine apparent remote sensing penetration depths at a wavelength of 520 nm. Tests were made for various types of sediments under controlled conditions in a laboratory. Field tests were conducted in several different water bodies over a wide range of solar elevation angles. Laboratory results indicate that apparent penetration depth is significantly influenced by mineral content and/or size of suspended sediments. Field measurements show wide variation in apparent penetration depth, even when suspended solids concentration is nearly constant. Apparent penetration depth does not appear to be a strong function of solar elevation angle so long as the water mixture remains constant.

  4. Mechanisms of Skin Penetration by Schistosoma Mansoni Cercariae.

    DTIC Science & Technology

    Schistosoma mansoni , Penetration, Skin(Anatomy), Cercariae, Enzymes, Chymotrypsin, Blood serum, Calcium, Zinc, Parasitic diseases, Control...Inhibitors, Gamma globulin, Infections, Surfaces, Schistosomiasis , Humans, In vitro analysis

  5. Evaluation of offshore penetration tests at El Palito refinery, Venezuela

    SciTech Connect

    Rodriguez, J.I.; Simone, A.; Tichatscheck, C.; Boggess, R.

    1995-12-01

    Data from an offshore study in the western part of Venezuela are presented in terms of the penetration test data and liquefaction evaluation. Two types of penetration test were performed (SPT and DCPT) and the results of each are compared. This was made possible by the comparison testing performed at two different locations where the separation between boreholes with different penetration tests was small enough to allow direct comparison of the results. To the authors` knowledge, this is the first time that dynamic cone measurements have been made in an offshore environment. Comments in relation to the evaluation of liquefaction resistance based on the results of the offshore penetration testing are made.

  6. A SYSTEMIZATION AND PENETRATION STUDY FOR STRAIGHT CYLINDRICAL DUCTS,

    DTIC Science & Technology

    DUCTS, *NEUTRON BEAMS, DUCTED BODIES, ALUMINUM, NEUTRON DETECTORS, POLONIUM , BERYLLIUM, SOURCES, NEUTRON SCATTERING, SHIELDING, WATER, NEUTRON TRANSPORT THEORY, ISOTROPISM, DUCT BENDS, NEUTRON FLUX, PENETRATION.

  7. Effect of Liquid Penetrant Sensitivity on Probability of Detection

    NASA Technical Reports Server (NTRS)

    Parker, Bradford H.

    2011-01-01

    The objective of the task is to investigate the effect of liquid penetrant sensitivity level on probability of detection (POD) of cracks in various metals. NASA-STD-5009 currently requires the use of only sensitivity level 4 liquid penetrants for NASA Standard Level inspections. This requirement is based on the fact that the data used to establish the reliably detectable flaw sizes penetrant inspection was from studies performed in the 1970s using penetrant deemed to be equivalent only to modern day sensitivity level 4 penetrants. However, many NDE contractors supporting NASA Centers routinely use sensitivity level 3 penetrants. Because of the new NASA-STD-5009 requirement, these contractors will have to either shift to sensitivity level 4 penetrants or perform formal POD demonstration tests to qualify their existing process. We propose a study to compare the POD generated for two penetrant manufactures, Sherwin and Magnaflux, and for the two most common penetrant inspection methods, water washable and post emulsifiable, hydrophilic. NDE vendors local to GSFC will be employed. A total of six inspectors will inspect a set of crack panels with a broad range of fatigue crack sizes. Each inspector will perform eight inspections of the panel set using the combination of methods and sensitivity levels described above. At least one inspector will also perform multiple inspections using a fixed technique to investigate repeatability. The hit/miss data sets will be evaluated using both the NASA generated DOEPOD software and the MIL-STD-1823 software.

  8. Depth of penetration achieved by instrumented seabed penetrators during initial systems demonstration tests

    SciTech Connect

    Calloway, T.M.

    1984-02-01

    Two versions of a gun-launched Instrumented Seabed Penetrator (ISP-1 and ISP-2) were tested in the Gulf of Mexico in May 1982. In each case the gun was loaded with propellant and a penetrator, lowered to the seabed, then fired. ISP-1 traveled 28 m into the seabed, and ISP-2 traveled 36 m. ISP-1 determined its displacement from the gun by means of an on-board accelerometer and microprocessor; after coming to rest, it used an Explosive Acoustic Telemetry System to transmit this information. ISP-2 was connected to the gun with a wire rope which unspooled during flight, allowing the instrumentation package to be retrieved. The measured deceleration profiles from the instrumentation's data memory were then processed off-line to compute the speed and displacement of ISP-2 as a function of time. 14 references, 5 figures, 4 tables.

  9. Quantitative analysis of transcranial and intraparenchymal light penetration in human cadaver brain tissue.

    PubMed

    Tedford, Clark E; DeLapp, Scott; Jacques, Steven; Anders, Juanita

    2015-04-01

    Photobiomodulation (PBM) also known as low-level light therapy has been used successfully for the treatment of injury and disease of the nervous system. The use of PBM to treat injury and diseases of the brain requires an in-depth understanding of light propagation through tissues including scalp, skull, meninges, and brain. This study investigated the light penetration gradients in the human cadaver brain using a Transcranial Laser System with a 30 mm diameter beam of 808 nm wavelength light. In addition, the wavelength-dependence of light scatter and absorbance in intraparenchymal brain tissue using 660, 808, and 940 nm wavelengths was investigated. Intact human cadaver heads (n = 8) were obtained for measurement of light propagation through the scalp/skull/meninges and into brain tissue. The cadaver heads were sectioned in either the transverse or mid-sagittal. The sectioned head was mounted into a cranial fixture with an 808 nm wavelength laser system illuminating the head from beneath with either pulsed-wave (PW) or continuous-wave (CW) laser light. A linear array of nine isotropic optical fibers on a 5 mm pitch was inserted into the brain tissue along the optical axis of the beam. Light collected from each fiber was delivered to a multichannel power meter. As the array was lowered into the tissue, the power from each probe was recorded at 5 mm increments until the inner aspect of the dura mater was reached. Intraparenchymal light penetration measurements were made by delivering a series of wavelengths (660, 808, and 940 nm) through a separate optical fiber within the array, which was offset from the array line by 5 mm. Local light penetration was determined and compared across the selected wavelengths. Unfixed cadaver brains provide good anatomical localization and reliable measurements of light scatter and penetration in the CNS tissues. Transcranial application of 808 nm wavelength light penetrated the scalp, skull, meninges, and brain

  10. Aerosol generation by blower motors as a bias in assessing aerosol penetration into cabin filtration systems.

    PubMed

    Heitbrink, William A; Collingwood, Scott

    2005-01-01

    In cabin filtration systems, blower motors pressurize a vehicle cabin with clean filtered air and recirculate air through an air-conditioning evaporator coil and a heater core. The exposure reduction offered by these cabins is evaluated by optical particle counters that measure size-dependent aerosol concentration inside and outside the cabin. The ratio of the inside-to-outside concentration is termed penetration. Blower motors use stationary carbon brushes to transmit an electrical current through a rotating armature that abrades the carbon brushes. This creates airborne dust that may affect experimental evaluations of aerosol penetration. To evaluate the magnitude of these dust emissions, blower motors were placed in a test chamber and operated at 12 and 13.5 volts DC. A vacuum cleaner drew 76 m3/hour (45 cfm) of air through HEPA filters, the test chamber, and through a 5 cm diameter pipe. An optical particle counter drew air through an isokinetic sampling probe and measured the size-dependent particle concentrations from 0.3 to 15 microm. The concentration of blower motor aerosol was between 2 x 10(5) and 1.8 x 10(6) particles/m3. Aerosol penetration into three stationary vehicles, two pesticide application vehicles and one tractor were measured at two conditions: low concentration (outside in the winter) and high concentration (inside repair shops and burning incense sticks used as a supplemental aerosol source). For particles smaller than 1 microm, the in-cabin concentrations can be explained by the blower motor emissions. For particles larger than 1 microm, other aerosol sources, such as resuspended dirt, are present. Aerosol generated by the operation of the blower motor and by other sources can bias the exposure reduction measured by optical particle counters.

  11. Penetration, Post-penetration Development, and Reproduction of Meloidogyne incognita on Cucumis melo var. texanus.

    PubMed

    Faske, T R

    2013-03-01

    Cucumis melo var. texanus, a wild melon commonly found in the southern United States and two accessions, Burleson Co. and MX 1230, expressed resistance to Meloidogyne incognita in preliminary experiments. To characterize the mechanism of resistance, we evaluated root penetration, post-penetration development, reproduction, and emigration of M. incognita on these two accessions of C. melo var. texanus. Additionally, we evaluated 22 accessions of C. melo var. texanus for their reaction against M. incognita in a greenhouse experiment. Fewer (P ≤ 0.05) J2 penetrated the root system of C. melo var. texanus accessions (Burleson Co. and MX 1230) and C. metuliferus (PI 482452) (resistant control), 7 days after inoculation (DAI) than in C. melo 'Hales Best Jumbo' (susceptible control). A delayed (P ≤ 0.05) rate of nematode development was observed at 7, 14, and 21 DAI that contributed to lower (P ≤ 0.05) egg production on both accessions and C. metuliferus compared with C. melo. Though J2 emigration was observed on all Cucumis genotypes a higher (P ≤ 0.05) rate of J2 emigration was observed from 3 to 6 DAI on accession Burleson Co. and C. metuliferus than on C. melo. The 22 accessions of C. melo var. texanus varied relative to their reaction to M. incognita with eight supporting similar levels of nematode reproduction to that of C. metuliferus. Cucumis melo var. texanus may be a useful source of resistance against root-knot nematode in melon.

  12. Features of mtDNA mutation patterns in European pedigrees and sporadic cases with leber hereditary optic neuropathy

    SciTech Connect

    Obermaier-Kusser, B.; Schubring, S.; Paprotta, A.; Meitinger, T.; Jaksch, M.; Gerbitz, K.D.; Lorenz, B.; Zerres, K.; Meire, F.; Cochaux, P.

    1994-11-01

    Leber hereditary optic neuropathy (LHON) is maternally transmitted and is characterized by bilateral loss of central vision in young adults as a result of optic nerve degeneration. Fifteen transition mutations located in different genes for the mitochondrially encoded subunits of respiratory chain complexes have been associated thus far with the disease. Genetic studies have led to the classification of the pathogenic significance of these different mutations. However, more research is required to determine the causality of the mutations and the penetrance of the disease. The present study compares studies of populations of different ethnic origins, namely European LHON pedigrees and sporadic cases, in order to elucidate the pathogenic mechanisms involved. 21 refs., 2 figs., 1 tab.

  13. In vivo methods for the analysis of the penetration of topically applied substances in and through the skin barrier.

    PubMed

    Lademann, J; Meinke, M C; Schanzer, S; Richter, H; Darvin, M E; Haag, S F; Fluhr, J W; Weigmann, H-J; Sterry, W; Patzelt, A

    2012-12-01

    The efficacy of a drug is characterized by its action mechanism and its ability to pass the skin barrier. In this article, different methods are discussed, which permit this penetration process to be analysed non-invasively. Providing qualitative and quantitative information, tape stripping is one of the oldest procedures for penetration studies. Although single cell layers of corneocytes are removed from the skin surface, this procedure is considered as non-invasive and is applicable exclusively to the stratum corneum. Recently, optical and spectroscopic methods have been used to investigate the penetration process. Fluorescence-labelled drugs can be easily detected in the skin by laser scanning microscopy. This method has the disadvantage that the dye labelling changes the molecular structures of the drug and consequently might influence the penetration properties. The penetration process of non-fluorescent substances can be analysed by Raman spectroscopy, electron paramagnetic resonance, CARS and multiphoton microscopic measurements. Using these methods, the concentration of the topically applied formulations in different depths of the stratum corneum can be detected by moving the laser focus from the skin surface deeper into the stratum corneum. The advantages and disadvantages of these methods will be discussed in this article.

  14. Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries

    NASA Astrophysics Data System (ADS)

    Zhang, Hairong; Salo, Daniel; Kim, David M.; Komarov, Sergey; Tai, Yuan-Chuan; Berezin, Mikhail Y.

    2016-12-01

    Measurement of photon penetration in biological tissues is a central theme in optical imaging. A great number of endogenous tissue factors such as absorption, scattering, and anisotropy affect the path of photons in tissue, making it difficult to predict the penetration depth at different wavelengths. Traditional studies evaluating photon penetration at different wavelengths are focused on tissue spectroscopy that does not take into account the heterogeneity within the sample. This is especially critical in shortwave infrared where the individual vibration-based absorption properties of the tissue molecules are affected by nearby tissue components. We have explored the depth penetration in biological tissues from 900 to 1650 nm using Monte-Carlo simulation and a hyperspectral imaging system with Michelson spatial contrast as a metric of light penetration. Chromatic aberration-free hyperspectral images in transmission and reflection geometries were collected with a spectral resolution of 5.27 nm and a total acquisition time of 3 min. Relatively short recording time minimized artifacts from sample drying. Results from both transmission and reflection geometries consistently revealed that the highest spatial contrast in the wavelength range for deep tissue lies within 1300 to 1375 nm however, in heavily pigmented tissue such as the liver, the range 1550 to 1600 nm is also prominent.

  15. Improving 6061-Al Grain Growth and Penetration across HIP-Bonded Clad Interfaces in Monolithic Fuel Plates: Initial Studies

    SciTech Connect

    Hackenberg, Robert E.; McCabe, Rodney J.; Montalvo, Joel D.; Clarke, Kester D.; Dvornak, Matthew J.; Edwards, Randall L.; Crapps, Justin M.; Trujillo, R. Ralph; Aikin, Beverly; Vargas, Victor D.; Hollis, Kendall J.; Lienert, Thomas J.; Forsyth, Robert T.; Harada, Kiichi L.

    2013-05-06

    Grain penetration across aluminum-aluminum cladding interfaces in research reactor fuel plates is desirable and was obtained by a legacy roll-bonding process, which attained 20-80% grain penetration. Significant grain penetration in monolithic fuel plates produced by Hot Isostatic Press (HIP) fabrication processing is equally desirable but has yet to be attained. The goal of this study was to modify the 6061-Al in such a way as to promote a much greater extent of crossinterface grain penetration in monolithic fuel plates fabricated by the HIP process. This study documents the outcomes of several strategies attempted to attain this goal. The grain response was characterized using light optical microscopy (LOM) electron backscatter diffraction (EBSD) as a function of these prospective process modifications done to the aluminum prior to the HIP cycle. The strategies included (1) adding macroscopic gaps in the sandwiches to enhance Al flow, (2) adding engineering asperities to enhance Al flow, (3) adding stored energy (cold work), and (4) alternative cleaning and coating. Additionally, two aqueous cleaning methods were compared as baseline control conditions. The results of the preliminary scoping studies in all the categories are presented. In general, none of these approaches were able to obtain >10% grain penetration. Recommended future work includes further development of macroscopic grooving, transferred-arc cleaning, and combinations of these with one another and with other processes.

  16. Ground Penetrating Radar Technologies in Ukraine

    NASA Astrophysics Data System (ADS)

    Pochanin, Gennadiy P.; Masalov, Sergey A.

    2014-05-01

    Transient electromagnetic fields are of great interest in Ukraine. The following topics are studied by research teams, with high-level achievements all over the world: (i) Ultra-Wide Band/Short-pulse radar techniques (IRE and LLC "Transient Technologies", for more information please visit http://applied.ire.kharkov.ua/radar%20systems_their%20components%20and%20relevant%20technologies_e.html and http://viy.ua); (ii) Ground Penetrating Radar (GPR) with stepped frequency sounding signals (IRE); (iii) Continuous-Wave (CW) radar with phase-shift keying signals (IRE); and (iv) Radio-wave interference investigation (Scientific and Technical Centre of The Subsurface Investigation, http://geophysics.ua). GPR applications are mainly in search works, for example GPR is often used to search for treasures. It is also used to identify leaks and diffusion of petroleum in soil, in storage areas, as well as for fault location of pipelines. Furthermore, GPR is used for the localization of underground utilities and for diagnostics of the technical state of hydro dams. Deeper GPR probing was performed to identify landslides in Crimea. Rescue radar with CW signal was designed in IRE to search for living people trapped under the rubble of collapsed buildings. The fourth version of this radar has been recently created, showing higher stability and noise immunity. Radio-wave interference investigation allows studying the soil down to tens of meters. It is possible to identify areas with increased conductivity (moisture) of the soil. LLC "Transient Technologies" is currently working with Shevchenko Kyiv University on a cooperation program in which the construction of a test site is one of the planned tasks. In the framework of this program, a GPR with a 300 MHz antenna was handed to the geological Faculty of the University. Employees of "Transient Technologies" held introductory lectures with a practical demonstration for students majoring in geophysics. The authors participated to GPR

  17. EDITORIAL: Special section on foliage penetration

    NASA Astrophysics Data System (ADS)

    Fiddy, M. A.; Lang, R.; McGahan, R. V.

    2004-04-01

    Waves in Random Media was founded in 1991 to provide a forum for papers dealing with electromagnetic and acoustic waves as they propagate and scatter through media or objects having some degree of randomness. This is a broad charter since, in practice, all scattering obstacles and structures have roughness or randomness, often on the scale of the wavelength being used to probe them. Including this random component leads to some quite different methods for describing propagation effects, for example, when propagating through the atmosphere or the ground. This special section on foliage penetration (FOPEN) focuses on the problems arising from microwave propagation through foliage and vegetation. Applications of such studies include the estimation for forest biomass and the moisture of the underlying soil, as well as detecting objects hidden therein. In addition to the so-called `direct problem' of trying to describe energy propagating through such media, the complementary inverse problem is of great interest and much harder to solve. The development of theoretical models and associated numerical algorithms for identifying objects concealed by foliage has applications in surveillance, ranging from monitoring drug trafficking to targeting military vehicles. FOPEN can be employed to map the earth's surface in cases when it is under a forest canopy, permitting the identification of objects or targets on that surface, but the process for doing so is not straightforward. There has been an increasing interest in foliage penetration synthetic aperture radar (FOPEN or FOPENSAR) over the last 10 years and this special section provides a broad overview of many of the issues involved. The detection, identification, and geographical location of targets under foliage or otherwise obscured by poor visibility conditions remains a challenge. In particular, a trade-off often needs to be appreciated, namely that diminishing the deleterious effects of multiple scattering from leaves is

  18. Shifting bubble-guided sutureless technique for performing descemetorhexis for retained Descemet's membrane after penetrating keratoplasty.

    PubMed

    Khokhar, Sudarshan; Agarwal, Tushar; Gupta, Shikha; Sehra, Srivats; Panda, Anita

    2014-02-01

    We describe the use of anterior segment optical coherence tomography in the diagnosis of inadvertent retention of Descemet's membrane (DM) after penetrating keratoplasty, and a novel technique for its removal in a case of congenital hereditary endothelial dystrophy. In this technique, we use a modification of the shifting bubble technique, commonly used in deep anterior lamellar keratoplasty where a viscocohesive ophthalmic viscosurgical device is injected into the false anterior chamber which causes migration of the central air bubble placed in the anterior chamber peripherally and helps in confirming the correct space. The DM is then peeled in a circular fashion with the help of 23-G vitreoretinal micro forceps.

  19. Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen saturation in old and young adults with near-infrared spectroscopy

    USDA-ARS?s Scientific Manuscript database

    We present near-infrared spectroscopy measurement of absolute cerebral hemoglobin concentration and saturation in a large sample of 36 healthy elderly (mean age, 85 ± 6 years) and 19 young adults (mean age, 28 ± 4 years). Non-invasive measurements were obtained on the forehead using a commercially a...

  20. Ice-Penetrating Robot for Scientific Exploration

    NASA Technical Reports Server (NTRS)

    Zimmerman, Wayne; Carsey, Frank; French, Lloyd

    2007-01-01

    The cryo-hydro integrated robotic penetrator system (CHIRPS) is a partially developed instrumentation system that includes a probe designed to deeply penetrate the European ice sheet in a search for signs of life. The CHIRPS could also be used on Earth for similar exploration of the polar ice caps especially at Lake Vostok in Antarctica. The CHIRPS probe advances downward by a combination of simple melting of ice (typically for upper, non-compacted layers of an ice sheet) or by a combination of melting of ice and pumping of meltwater (typically, for deeper, compacted layers). The heat and electric power for melting, pumping, and operating all of the onboard instrumentation and electronic circuitry are supplied by radioisotope power sources (RPSs) and thermoelectric converters energized by the RPSs. The instrumentation and electronic circuitry includes miniature guidance and control sensors and an advanced autonomous control system that has fault-management capabilities. The CHIRPS probe is about 1 m long and 15 cm in diameter. The RPSs generate a total thermal power of 1.8 kW. Initially, as this power melts the surrounding ice, a meltwater jacket about 1 mm thick forms around the probe. The center of gravity of the probe is well forward (down), so that the probe is vertically stabilized like a pendulum. Heat is circulated to the nose by means of miniature pumps and heat pipes. The probe melts ice to advance in a step-wise manner: Heat is applied to the nose to open up a melt void, then heat is applied to the side to allow the probe to slip down into the melt void. The melt void behind the probe is allowed to re-freeze. Four quadrant heaters on the nose and another four quadrant heaters on the rear (upper) surface of the probe are individually controllable for steering: Turning on two adjacent nose heaters on the nose and two adjacent heaters on the opposite side at the rear causes melt voids to form on opposing sides, such that the probe descends at an angle from