SU-8 microprobe with microelectrodes for monitoring electrical impedance in living tissues.

PubMed

Tijero, M; Gabriel, G; Caro, J; Altuna, A; Hernández, R; Villa, R; Berganzo, J; Blanco, F J; Salido, R; Fernández, L J

2009-04-15

This paper presents a minimally invasive needle-shaped probe capable of monitoring the electrical impedance of living tissues. This microprobe consists of a 160 microm thick SU-8 substrate containing four planar platinum (Pt) microelectrodes. We design the probe to minimize damage to the surrounding tissue and to be stiff enough to be inserted in living tissues. The proposed batch fabrication process is low cost and low time consuming. The microelectrodes obtained with this process are strongly adhered to the SU-8 substrate and their impedance does not depend on frequency variation. In vitro experiments are compared with previously developed Si and SiC based microprobes and results suggest that it is preferable to use the SU-8 based microprobes due to their flexibility and low cost. The microprobe is assembled on a flexible printed circuit FPC with a conductive glue, packaged with epoxy and wired to the external instrumentation. This flexible probe is inserted into a rat kidney without fracturing and succeeds in demonstrating the ischemia monitoring.

Evaluation of insertion characteristics of less invasive Si optoneural probe with embedded optical fiber

NASA Astrophysics Data System (ADS)

Morikawa, Takumi; Harashima, Takuya; Kino, Hisashi; Fukushima, Takafumi; Tanaka, Tetsu

2017-04-01

A less invasive Si optoneural probe with an embedded optical fiber was proposed and successfully fabricated. The diameter of the optical fiber was completely controlled by hydrogen fluoride etching, and the thinned optical fiber can propagate light without any leakage. This optical fiber was embedded in a trench formed inside a probe shank, which causes less damage to tissues. In addition, it was confirmed that the optical fiber embedded in the probe shank successfully irradiated light to optically stimulate gene transfected neurons. The electrochemical impedance of the probe did not change despite the light irradiation. Furthermore, probe insertion characteristics were evaluated in detail and less invasive insertion was clearly indicated for the Si optoneural probe with the embedded optical fiber compared with conventional optical neural probes. This neural probe with the embedded optical fiber can be used as a simple and easy tool for optogenetics and brain science.

pHLIP-FIRE, a Cell Insertion-Triggered Fluorescent Probe for Imaging Tumors Demonstrates Targeted Cargo Delivery In Vivo

PubMed Central

2015-01-01

We have developed an improved tool for imaging acidic tumors by reporting the insertion of a transmembrane helix: the pHLIP-Fluorescence Insertion REporter (pHLIP-FIRE). In acidic tissues, such as tumors, peptides in the pHLIP family insert as α-helices across cell membranes. The cell-inserting end of the pHLIP-FIRE peptide has a fluorophore–fluorophore or fluorophore–quencher pair. A pair member is released by disulfide cleavage after insertion into the reducing environment inside a cell, resulting in dequenching of the probe. Thus, the fluorescence of the pHLIP-FIRE probe is enhanced upon cell-insertion in the targeted tissues but is suppressed elsewhere due to quenching. Targeting studies in mice bearing breast tumors show strong signaling by pHLIP-FIRE, with a contrast index of ∼17, demonstrating (i) direct imaging of pHLIP insertion and (ii) cargo translocation in vivo. Imaging and targeted cargo delivery should each have clinical applications. PMID:25184440

Flexible poly(methyl methacrylate)-based neural probe: An affordable implementation

NASA Astrophysics Data System (ADS)

Gasemi, Pejman; Veladi, Hadi; Shahabi, Parviz; Khalilzadeh, Emad

2018-03-01

This research presents a novel technique used to fabricate a deep brain stimulation probe based on a commercial poly(methyl methacrylate) (PMMA) polymer. This technique is developed to overcome the high cost of available probes crucial for chronic stimulation and recording in neural disorders such as Parkinson’s disease and epilepsy. The probe is made of PMMA and its mechanical properties have been customized by controlling the reaction conditions. The polymer is adjusted to be stiff enough to be easily inserted and, on the other hand, soft enough to perform required movements. As cost is one of the issues in the use of neural probes, a simple process is proposed for the production of PMMA neural probes without using expensive equipment and operations, and without compromising performance and quality. An in vivo animal test was conducted to observe the recording capability of a PMMA probe.

Enhancing Continuous Online Microdialysis Using Dexamethasone: Measurement of Dynamic Neurometabolic Changes during Spreading Depolarization.

PubMed

Varner, Erika L; Leong, Chi Leng; Jaquins-Gerstl, Andrea; Nesbitt, Kathryn M; Boutelle, Martyn G; Michael, Adrian C

2017-08-16

Microdialysis is well established in chemical neuroscience as a mainstay technology for real time intracranial chemical monitoring in both animal models and human patients. Evidence shows that microdialysis can be enhanced by mitigating the penetration injury caused during the insertion of microdialysis probes into brain tissue. Herein, we show that retrodialysis of dexamethasone in the rat cortex enhances the microdialysis detection of K + and glucose transients induced by spreading depolarization. Without dexamethasone, quantification of glucose transients was unreliable by 5 days after probe insertion. With dexamethasone, robust K + and glucose transients were readily quantified at 2 h, 5 days, and 10 days after probe insertion. The amplitudes of the K + transients declined day-to-day following probe insertion, and the amplitudes of the glucose transients exhibited a decreasing trend that did not reach statistical significance. Immunohistochemistry and fluorescence microscopy confirm that dexamethasone is highly effective at preserving a healthy probe-brain interface for at least 10 days even though retrodialysis of dexamethasone ceased after 5 days.

Tensiometer, drive probe for use with environmental testing equipment, and methods of inserting environmental testing equipment into a sample

DOEpatents

Hubbell, Joel M.; Sisson, James B.

2005-07-26

A method of inserting a tensiometer into a sample, comprises providing a drive probe configured to be engaged by direct push equipment; supporting a porous member from the drive probe; and driving the drive probe into the sample using a cone penetrometer. A tensiometer comprises a drive probe configured to be engaged by direct push equipment or a cone penetrometer; a porous member supported by the drive probe; and a pressure sensor in pressure sensing relation to the porous member.

Is periprostatic nerve block a gold standard in case of transrectal ultrasound-guided prostate biopsy?

PubMed Central

Kumar, Ashok; Griwan, Mahavir Singh; Singh, Santosh Kumar; Sen, Jyotsna; Pawar, D. S.

2013-01-01

Introduction: Controversy exists over the pain during prostate biopsy. Periprostatic nerve block (PNB) is a gold standard anesthetic technique during transrectal ultrasound (TRUS)-guided prostate biopsy. Recent studies showed that PNB alone is insufficient as analgesic. We compared the efficacy of tramadol and intraprostatic nerve block (INB) in addition to PNB. Materials and Methods: We conducted a prospective double blinded placebo controlled study at our institute in 150 consecutive patients. Patients were randomized into three groups. Group A received PNB with INB with 1% lignocaine. Group B received oral tramadol with PNB. Group C patients were administered PNB only with 1% lignocaine. Patients were asked to grade the pain level using 11 point linear visual analog scale (VAS) at the time of ultrasound probe insertion, at time of anesthesia, during biopsy, and 30 min after biopsy. Results: The study groups were comparable in demographic profile, prostate-specific antigen (PSA) levels, and prostate size. Group A recorded the minimum mean pain score of 2.66 during prostate biopsy which was significantly lower than group 3 (P < 0.001). Group B recorded significantly lower pain score at time of probe insertion and at anesthetic needle insertion than other two groups. Conclusions: PNB provides better pain control in TRUS-guided prostate biopsy but still there is need of additional analgesic in the form of tramadol or INB. Tramadol has advantage of oral intake and analgesic effect at time of probe insertion and at nerve block. Both tramadol and INB may be used in combination along with PNB. PMID:24049376

Innovative SPM Probes for Energy-Storage Science: MWCNT-Nanopipettes to Nanobattery Probes

NASA Astrophysics Data System (ADS)

Larson, Jonathan; Talin, Alec; Pearse, Alexander; Kozen, Alexander; Reutt-Robey, Janice

As energy-storage materials and designs continue to advance, new tools are needed to direct and explore ion insertion/de-insertion at well-defined battery materials interfaces. Scanned probe tips, assembled from actual energy-storage materials, permit SPM measures of local cathode-anode (tip-sample) interactions, including ion transfer. We present examples of ``cathode'' MWCNT-terminated STM probe tips interacting with Li(s)/Si(111) anode substrates. The MWCNT tip functions as both SPM probe and Li-nanopipette,[1] for controlled transport and manipulation of Li. Local field conditions for lithium ionization and transfer are determined and compared to electrostatic models. Additional lithium metallic and oxide tips have been prepared by thin film deposition on conventional W tips, the latter of which effectively functions as a nanobattery. We demonstrate use of these novel probe materials in the local lithiation of low-index Si anode interfaces, probing local barriers for lithium insertion. Prospects and limitations of these novel SPM probes will be discussed. U.S. Department of Energy Award Number DESC0001160.

Probe insertion apparatus with inflatable seal

NASA Technical Reports Server (NTRS)

Trimarchi, Paul A. (Inventor)

1990-01-01

A sealing apparatus is disclosed for inserting a probe into a pressure vessel having an elongated opening includes a pair of resiliently deformable seals opposingly disposed in sealing engagement with each other. A retainer is connected to the pressure vessel around the elongated opening and holds the pair of seals rigidly to the pressure vessel. A wedge is engageable with the pair of seals and carries the probe, for longitudinally translating the probe in pressure vessel.

Effect of Probe Tube Insertion Depth on Spectral Measures of Speech

PubMed Central

Caldwell, Marc; Souza, Pamela E.; Tremblay, Kelly L.

2006-01-01

This study investigated how depth variations in the tip of the probe tube affected spectral measures of speech recorded in the external ear canal. Consonant-vowel nonsense syllables were recorded with a probe tube microphone system in 10 adult participants with normal middle ear function. Recordings were made with the probe tube tip placed 1 mm, 5 mm, and 10 mm beyond the medial tip of a custom earmold. The effect of probe depth was evaluated on spectral levels (one-third octave and one-twelfth octave band). Extending the probe tube 10 mm past the medial tip of the earmold gave the most accurate results, with relatively lower sound levels for either the 1-mm or 5-mm insertion depth. In general, the effect of insertion depth was minimal at frequencies below 3 to 4 kHz, although this varied with the specific phoneme and the width of the analysis bands. The authors found no significant difference between 1- and 5-mm insertion depths, suggesting that as long as the tip of the probe tube is sufficiently close to the tympanic membrane to capture the highest frequency of interest, it makes little difference if it is less than 5 mm beyond the earmold tip. PMID:16959735

Navigating conjugated polymer actuated neural probes in a brain phantom

NASA Astrophysics Data System (ADS)

Daneshvar, Eugene D.; Kipke, Daryl; Smela, Elisabeth

2012-04-01

Neural probe insertion methods have a direct impact on the longevity of the device in the brain. Initial tissue and vascular damage caused by the probe entering the brain triggers a chronic tissue response that is known to attenuate neural recordings and ultimately encapsulate the probes. Smaller devices have been found to evoke reduced inflammatory response. One way to record from undamaged neural networks may be to position the electrode sites away from the probe. To investigate this approach, we are developing probes with controllably movable electrode projections, which would move outside of the zone that is damaged by the insertion of the larger probe. The objective of this study was to test the capability of conjugated polymer bilayer actuators to actuate neural electrode projections from a probe shank into a transparent brain phantom. Parylene neural probe devices, having five electrode projections with actuating segments and with varying widths (50 - 250 μm) and lengths (200 - 1000 μm) were fabricated. The electroactive polymer polypyrrole (PPy) was used to bend or flatten the projections. The devices were inserted into the brain phantom using an electronic microdrive while simultaneously activating the actuators. Deflections were quantified based on video images. The electrode projections were successfully controlled to either remain flat or to actuate out-of-plane and into the brain phantom during insertion. The projection width had a significant effect on their ability to deflect within the phantom, with thinner probes deflecting but not the wider ones. Thus, small integrated conjugated polymer actuators may enable multiple neuro-experiments and applications not possible before.

Vacuum-actuated percutaneous insertion/implantation tool for flexible neural probes and interfaces

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

Sheth, Heeral; Bennett, William J.; Pannu, Satinderpall S.

A flexible device insertion tool including an elongated stiffener with one or more suction ports, and a vacuum connector for interfacing the stiffener to a vacuum source, for attaching the flexible device such as a flexible neural probe to the stiffener during insertion by a suction force exerted through the suction ports to, and to release the flexible device by removing the suction force.

An optical probe for local measurements of fast plasma ion dynamics

NASA Astrophysics Data System (ADS)

Fiksel, G.; Den Hartog, D. J.; Fontana, P. W.

1998-05-01

A novel insertable probe for local measurements of equilibrium and fluctuating plasma ion flow velocity and temperature via Doppler spectroscopy is described. Optical radiation is collected by two fused silica fiber optic bundles with perpendicular viewlines. Spatial resolution of about 5 cm is achieved by terminating each view with an optical dump. The collected light is transported by the fiber bundles to a high-resolution spectrometer. Two components of the velocity are measured simultaneously—the radial along the insertion of the probe and a perpendicular component (which can be varied by simply rotating the probe by 90°). The accuracy of the velocity measurements is better than 1 km/s. The probe is armored by a boron nitride enclosure and is inserted into a high temperature plasma to obtain radial profiles of the equilibrium and fluctuating plasma velocity. Initial measurements have been done in Madison Symmetric Torus reversed field pinch.

A modification of the trans-oesophageal echocardiography protocol can reduce post-operative dysphagia following cardiac surgery.

PubMed

Chin, J-H; Lee, E-H; Choi, D-K; Choi, I-C

2011-01-01

Use of intra-operative trans-oesophageal echocardiography (TEE) is an independent risk factor for post-operative dysphagia. This study investigated whether modifying the TEE probe-placement protocol could reduce the incidence of post-operative dysphagia. In group I (n = 100), the TEE probe was inserted after anaesthetic induction and remained in place until the completion of surgery. In group II (n = 100), the TEE probe was inserted after anaesthetic induction, the heart was examined, then the probe was removed. The probe was inserted again before weaning from cardiopulmonary bypass and then immediately removed after examination. The incidence of dysphagia was significantly higher in group I than in group II patients (51.1% versus 28.6%). Multivariate regression analysis showed that the length of time that the TEE probe was in the oesophagus was an independent predictor of dysphagia. Modification of the TEE protocol in this way can reduce the incidence of post-operative dysphagia in cardiac surgery patients.

Method and apparatus for probing relative volume fractions

DOEpatents

Jandrasits, Walter G.; Kikta, Thomas J.

1998-01-01

A relative volume fraction probe particularly for use in a multiphase fluid system includes two parallel conductive paths defining therebetween a sample zone within the system. A generating unit generates time varying electrical signals which are inserted into one of the two parallel conductive paths. A time domain reflectometer receives the time varying electrical signals returned by the second of the two parallel conductive paths and, responsive thereto, outputs a curve of impedance versus distance. An analysis unit then calculates the area under the curve, subtracts the calculated area from an area produced when the sample zone consists entirely of material of a first fluid phase, and divides this calculated difference by the difference between an area produced when the sample zone consists entirely of material of the first fluid phase and an area produced when the sample zone consists entirely of material of a second fluid phase. The result is the volume fraction.

Method and apparatus for probing relative volume fractions

DOEpatents

Jandrasits, W.G.; Kikta, T.J.

1998-03-17

A relative volume fraction probe particularly for use in a multiphase fluid system includes two parallel conductive paths defining therebetween a sample zone within the system. A generating unit generates time varying electrical signals which are inserted into one of the two parallel conductive paths. A time domain reflectometer receives the time varying electrical signals returned by the second of the two parallel conductive paths and, responsive thereto, outputs a curve of impedance versus distance. An analysis unit then calculates the area under the curve, subtracts the calculated area from an area produced when the sample zone consists entirely of material of a first fluid phase, and divides this calculated difference by the difference between an area produced when the sample zone consists entirely of material of the first fluid phase and an area produced when the sample zone consists entirely of material of a second fluid phase. The result is the volume fraction. 9 figs.

Design, fabrication and experimental validation of a novel dry-contact sensor for measuring electroencephalography signals without skin preparation.

PubMed

Liao, Lun-De; Wang, I-Jan; Chen, Sheng-Fu; Chang, Jyh-Yeong; Lin, Chin-Teng

2011-01-01

In the present study, novel dry-contact sensors for measuring electro-encephalography (EEG) signals without any skin preparation are designed, fabricated by an injection molding manufacturing process and experimentally validated. Conventional wet electrodes are commonly used to measure EEG signals; they provide excellent EEG signals subject to proper skin preparation and conductive gel application. However, a series of skin preparation procedures for applying the wet electrodes is always required and usually creates trouble for users. To overcome these drawbacks, novel dry-contact EEG sensors were proposed for potential operation in the presence or absence of hair and without any skin preparation or conductive gel usage. The dry EEG sensors were designed to contact the scalp surface with 17 spring contact probes. Each probe was designed to include a probe head, plunger, spring, and barrel. The 17 probes were inserted into a flexible substrate using a one-time forming process via an established injection molding procedure. With these 17 spring contact probes, the flexible substrate allows for high geometric conformity between the sensor and the irregular scalp surface to maintain low skin-sensor interface impedance. Additionally, the flexible substrate also initiates a sensor buffer effect, eliminating pain when force is applied. The proposed dry EEG sensor was reliable in measuring EEG signals without any skin preparation or conductive gel usage, as compared with the conventional wet electrodes.

Design, Fabrication and Experimental Validation of a Novel Dry-Contact Sensor for Measuring Electroencephalography Signals without Skin Preparation

PubMed Central

Liao, Lun-De; Wang, I-Jan; Chen, Sheng-Fu; Chang, Jyh-Yeong; Lin, Chin-Teng

2011-01-01

In the present study, novel dry-contact sensors for measuring electro-encephalography (EEG) signals without any skin preparation are designed, fabricated by an injection molding manufacturing process and experimentally validated. Conventional wet electrodes are commonly used to measure EEG signals; they provide excellent EEG signals subject to proper skin preparation and conductive gel application. However, a series of skin preparation procedures for applying the wet electrodes is always required and usually creates trouble for users. To overcome these drawbacks, novel dry-contact EEG sensors were proposed for potential operation in the presence or absence of hair and without any skin preparation or conductive gel usage. The dry EEG sensors were designed to contact the scalp surface with 17 spring contact probes. Each probe was designed to include a probe head, plunger, spring, and barrel. The 17 probes were inserted into a flexible substrate using a one-time forming process via an established injection molding procedure. With these 17 spring contact probes, the flexible substrate allows for high geometric conformity between the sensor and the irregular scalp surface to maintain low skin-sensor interface impedance. Additionally, the flexible substrate also initiates a sensor buffer effect, eliminating pain when force is applied. The proposed dry EEG sensor was reliable in measuring EEG signals without any skin preparation or conductive gel usage, as compared with the conventional wet electrodes. PMID:22163929

Modified perianal/pericapsular anesthesia for transrectal biopsy of prostate in patients with anal rectal problems.

PubMed

Kravchick, Sergey; Yoffe, Boris; Cytron, Shmuel

2007-01-01

To modify our technique of perianal anesthesia and use it in patients with painful conditions of the rectum and/or anus. A total of 31 consecutive patients with anal-rectal problems underwent prostate needle biopsy. Of these, 17 were referred to our hospital after vain attempts to insert a transrectal ultrasound probe. Patients received a perianal-pericapsular injection of 1% lidocaine. Pain perception was separately assessed for probe insertion and biopsies using a visual pain analog score. Only in 1 patient were we unable to insert the transrectal ultrasound probe. The mean patient age was 65.28 +/- 5.35 years. We performed a mean of 12.25 biopsies per case. At probe insertion, the mean pain score was 2.2 +/- 0.83. During the biopsy punctures, the mean pain level was 2.53 +/- 1.054. We did not find any increase in the complication rate related to the anesthesia method. Modified perianal anesthesia can be used for transrectal ultrasound-guided biopsy of the prostate in patients with anal-rectal problems, because it provides significant pain relief.

Hollow Cathode and Keeper-region Plasma Measurements Using Ultra-fast Miniature Scanning Probes

NASA Technical Reports Server (NTRS)

Goebel, Dan M.; Jameson, Kristina K.; Watkins, Ron M.; Katz, Ira

2004-01-01

In order to support the development of comprehensive performance and life models for future deep space missions that will utilize ion thrusters, we have undertaken a study of the plasma structure in hollow cathodes using an new pneumatic scanning probe diagnostic. This device is designed to insert a miniature probe directly into the hollow cathode orifice from either the upstream insert region in the interior of the hollow cathode, or from the downstream keeper-plasma region at the exit of the hollow cathode, to provide complete axial profiles of the discharge plasma parameters. Previous attempts to diagnose this region with probes was Limited by the melting of small probes in the intense discharge near the orifice, or caused significant perturbation of the plasma by probes large enough to survive. Our new probe is extremely compact, and when configured as a single Langmuir probe, the ceramic tube insulator is only 0.5mm in diameter and the current collecting conductor has a total area of 0.002 cm2. A series of current-voltage characteristics are obtained by applying a rapid sawtooth voltage waveform to the probe as it is scanned by the pneumatic actuator into and out of the plasma region, The bellow-sealed pneumatic drive scans the probe 4 cm in the cathode insert region and 10 cm in the anode/keeper plasmas region at average speeds of about 1 mm/msec, and the residence time at the end of the insertion stroke in the densest part of the plasma near the orifice is measured to be only 10 msec. Since the voltage sweep time is fast compared to the motion of the probe, axial profiles of the plasma density, temperature and potential with reasonable spatial resolution are obtained. Measurements of the internal cathode pressures and the axial plasma-parameter profiles for a hollow cathode operating at discharge currents of up to 35 A in xenon will be presented.

Profiling Groundwater Salt Concentrations in Mangrove Swamps and Tropical Salt Flats

NASA Astrophysics Data System (ADS)

Ridd, Peter V.; Sam, Renagi

1996-11-01

The salt concentration of groundwater in mangrove swamps is an important parameter controlling the growth of mangrove species. Extremely high salt concentrations of groundwater in tropical salt flats are responsible for the complete absence of macrophytes. Determining groundwater salt concentrations can be a very time-consuming and laborious process if conventional techniques are used. Typically, groundwater samples must be extracted for later laboratory analysis. In this work, a simple conductivity probe has been developed which may be inserted easily to a depth of 2 m into the sediment. The changes in conductivity of the sediment is due primarily to porewater salt concentration, and thus ground conductivity is useful in determining changes in groundwater salt concentrations. Using the conductivity probe, transects of sediment conductivity can be undertaken quickly. As an example of a possible application of the probe, transects of ground conductivity were taken on a mangrove swamp/saltflat system. The transects show clearly the sharp delineation in conductivity between the salt flat and mangrove swamp due to a change in groundwater salt concentrations. Horizontal and vertical salt concentration gradients of up to 50 g l -1 m -1and 150 g l -1 m -1, respectively, were found. Very sharp changes in groundwater salt concentrations at the interface between salt flats and mangroves indicate that the mangroves may be modifying the salinity of the groundwater actively.

Dedicated mobile high resolution prostate PET imager with an insertable transrectal probe

DOEpatents

Majewski, Stanislaw; Proffitt, James

2010-12-28

A dedicated mobile PET imaging system to image the prostate and surrounding organs. The imaging system includes an outside high resolution PET imager placed close to the patient's torso and an insertable and compact transrectal probe that is placed in close proximity to the prostate and operates in conjunction with the outside imager. The two detector systems are spatially co-registered to each other. The outside imager is mounted on an open rotating gantry to provide torso-wide 3D images of the prostate and surrounding tissue and organs. The insertable probe provides closer imaging, high sensitivity, and very high resolution predominately 2D view of the prostate and immediate surroundings. The probe is operated in conjunction with the outside imager and a fast data acquisition system to provide very high resolution reconstruction of the prostate and surrounding tissue and organs.

Development of a new mini-invasive tumour hyperthermia probe using high-temperature water vapour.

PubMed

Yu, Tian-Hua; Zhou, Yi-Xin; Liu, Jing

2004-01-01

A new mini-invasive hyperthermia probe using high-temperature water vapour for deep regional tumour treatment was developed in this paper. The vacuum insulation mechanism was incorporated into the probe to avoid heating damage to the normal tissues around the edge of the insertion path. To better understand the heat transfer behaviour in living tissues due to operation of the probe, theoretical models based on the Pennes' equation were established and two closed form analytical solutions under constant flux or temperature heating at the tip of probe were obtained. Parametric studies were performed to investigate the influence of various parameters on the temperature response of tissues heated by the probe. Further, several simulating experiments on the actual heating performance of the probe fabricated in this paper were conducted on the in vitro biological materials (fresh pork) and phantom gel. It was demonstrated that the probe can cause a high enough temperature over the treatment area to thermally destroy the tumour tissue in due time, while the temperature over the surrounding healthy tissues can be kept below a safe threshold value. This mini-invasive heating probe may have significant applications in future clinical tumour hyperthermia.

RNA detection using peptide-inserted Renilla luciferase.

PubMed

Andou, Takashi; Endoh, Tamaki; Mie, Masayasu; Kobatake, Eiry

2009-01-01

A novel complementation system with short peptide-inserted-Renilla luciferase (PI-Rluc) and split-RNA probes was constructed for noninvasive RNA detection. The RNA binding peptides HIV-1 Rev and BIV Tat were used as inserted peptides. They display induced fit conformational changes upon binding to specific RNAs and trigger complementation or discomplementation of Rluc. Split-RNA probes were designed to reform the peptide binding site upon hybridization with arbitrarily selected target RNA. This set of recombinant protein and split-RNA probes enabled a high degree of sensitivity in RNA detection. In this study, we show that the Rluc system is comparable to Fluc, but that its detection limit for arbitrarily selected RNA (at least 100 pM) exceeds that of Fluc by approximately two orders of magnitude.

Submillisecond Dynamics of Mastoparan X Insertion into Lipid Membranes.

PubMed

Schuler, Erin E; Nagarajan, Sureshbabu; Dyer, R Brian

2016-09-01

The mechanism of protein insertion into a lipid bilayer is poorly understood because the kinetics of this process is difficult to measure. We developed a new approach to study insertion of the antimicrobial peptide Mastoparan X into zwitterionic lipid vesicles, using a laser-induced temperature-jump to initiate insertion on the microsecond time scale and infrared and fluorescence spectroscopies to follow the kinetics. Infrared probes the desolvation of the peptide backbone and yields biphasic kinetics with relaxation lifetimes of 12 and 117 μs, whereas fluorescence probes the intrinsic tryptophan residue located near the N-terminus and yields a single exponential phase with a lifetime of 440 μs. Arrhenius analysis of the temperature-dependent rates yields an activation energy for insertion of 96 kJ/mol. These results demonstrate the complexity of the insertion process and provide mechanistic insight into the interplay between peptides and the lipid bilayer required for peptide transport across cellular membranes.

Silk and PEG as means to stiffen a parylene probe for insertion in the brain: toward a double time-scale tool for local drug delivery

NASA Astrophysics Data System (ADS)

Lecomte, A.; Castagnola, V.; Descamps, E.; Dahan, L.; Blatché, M. C.; Dinis, T. M.; Leclerc, E.; Egles, C.; Bergaud, C.

2015-12-01

The use of soft materials as substrate for neural probes aims at achieving better compliance with the surrounding neurons while maintaining minimal rejection. Many strategies have emerged to enable such probes to penetrate the cortex, among which the use of resorbable polymers. We performed several tests involving two resorbable polymers considered most promising: polyethylene glycol (PEG) and silk fibroin (SF) from Bombyx Mori silkworms. Our coating method provides a repeatable, uniform structure optimized for a stress-reduced insertion of a parylene-C neural probe. Standard compression tests as well as in vitro and in vivo insertion assessments show that both SF and PEG-coated probes are stiff enough to avoid the buckling effect during insertion in the cortex. However, with a buckling force of 300 mN and a mechanical holding in vitro of tens of minutes, we assess silk fibroin to be more reliable for practical handling. In vivo first try-outs in mouse brain showed neither buckling issues of the probe nor undesired alteration of the signal recording. Moreover, we evidenced two distinct time scales in the bioresorption of our polymer coatings: silk fibroin degrades itself in a matter of weeks and PEG dissolves itself within seconds in the presence of water. We then present a hybrid PEG and SF coating that could be used as a drug delivery system with different time scales to reduce both the acute and the chronic body reaction.

Improved efficiency of nanoneedle insertion by modification with a cell-puncturing protein

NASA Astrophysics Data System (ADS)

Ryu, Seunghwan; Matsumoto, Yuta; Matsumoto, Takahiro; Ueno, Takafumi; Silberberg, Yaron R.; Nakamura, Chikashi

2018-03-01

An atomic force microscope (AFM) probe etched into an ultra-sharp cylindrical shape (a nanoneedle) can be inserted into a living cell and mechanical responses of the insertion process are represented as force-distance curves using AFM. A probe-molecule-functionalized nanoneedle can be used to detect intracellular molecules of interest in situ. The insertion efficiencies of nanoneedles vary among cell types due to the cortex structures of cells, and some cell types, such as mouse fibroblast Balb/3T3 cells, show extremely low efficacy of insertion. We addressed this issue by using a cell membrane puncturing protein from bacteriophage T4 (gp5), a needle-like protein that spontaneously penetrates through the cell membrane. Gp5 was immobilized onto a nanoneedle surface. The insertion efficiency of the functionalized nanoneedle increased by over 15% compared to the non-functionalized control. Gp5-modification is a versatile approach in cell manipulation techniques for the insertion of other types of nanostructures into cells.

Method for reducing measurement errors of a Langmuir probe with a protective RF shield

NASA Astrophysics Data System (ADS)

Riaby, V.; Masherov, P.; Savinov, V.; Yakunin, V.

2018-04-01

Probe measurements were conducted in the middle cross-section of an inductive, low-pressure xenon plasma using a straight cylindrical Langmuir probe with a bare metal shield that protected the probe from radio frequency interference. As a result, reliable radial distributions of the plasma parameters were obtained. Subsequent analyses of these measurements revealed that the electron energy distribution function (EEDF) deviated substantially from the Maxwellian functions and that this deviation depended on the length of the probe shield. To evaluate the shield's influence on the measurement results, in addition to the probe (which was moved radially as its shield length varied in the range of lsh1 = lmax-0), an additional L-shaped probe was inserted at a different location. This probe was moved differently from the first probe and provided confirmational measurements in the common special position where lsh1 = 0 and lsh2 ≠ 0. In this position, the second shield decreased all the plasma parameters. A comparison of the probe datasets identified the principles of the relationships between measurement errors and EEDF distortions caused by the bare probe shields. This dependence was used to correct the measurements performed using the first probe by eliminating the influence of its shield. Physical analyses based on earlier studies showed that these peculiarities are caused by a short-circuited double-probe effect that occurs in bare metal probe protective shields.

Measurement of food texture by an acoustic vibration method

NASA Astrophysics Data System (ADS)

Sakurai, Naoki; Taniwaki, Mitsuru; Iwatani, Shin-ichiro; Akimoto, Hidemi

2011-09-01

Food texture was measured by a new acoustic vibration method. A piezoelectric sensor sandwiched between a probe and piston was inserted into a food sample by delivery of silicon oil to a cylinder by a pump. Vibration emitted from the food sample on insertion of the probe was monitored by voltage outputs of the sensor. The voltage signals were passed through 19 half octave bands to calculate texture index for each band. The texture index was defined as vibration energy of the probe caused by the food rupture and/or breakage per unit time.

A probe for blood-vessel and spinal interiors

NASA Technical Reports Server (NTRS)

Frazer, R. E.

1978-01-01

Probe design allows insertion into lumen of blood vessels to perform oximetry and investigate plaque on interior vessel walls. Probe is more accurate than standard oximetry procedures of determining oxygenation of circulating blood.

Method and apparatus for probing relative volume fractions

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

Jandrasits, W.G.; Kikta, T.J.

1996-12-31

A relative volume fraction probe particularly for use in a multiphase fluid system includes two parallel conductive paths defining there between a sample zone within the system. A generating unit generates time varying electrical signals which are inserted into one of the two parallel conductive paths. A time domain reflectometer receives the time varying electrical signals returned by the second of the two parallel conductive paths and, responsive thereto, outputs a curve of impedance versus distance. An analysis unit then calculates the area under the curve, subtracts the calculated area from an area produced when the sample zone consists entirelymore » of material of a first fluid phase, and divides this calculated difference by the difference between an area produced when the sample zone consists entirely of material of the first fluid phase and an area produced when the sample zone consists entirely of material of a second fluid phase. The result is the volume fraction.« less

Comparison of nine methods to estimate ear-canal stimulus levels

PubMed Central

Souza, Natalie N.; Dhar, Sumitrajit; Neely, Stephen T.; Siegel, Jonathan H.

2014-01-01

The reliability of nine measures of the stimulus level in the human ear canal was compared by measuring the sensitivity of behavioral hearing thresholds to changes in the depth of insertion of an otoacoustic emission probe. Four measures were the ear-canal pressure, the eardrum pressure estimated from it and the pressure measured in an ear simulator with and without compensation for insertion depth. The remaining five quantities were derived from the ear-canal pressure and the Thévenin-equivalent source characteristics of the probe: Forward pressure, initial forward pressure, the pressure transmitted into the middle ear, eardrum sound pressure estimated by summing the magnitudes of the forward and reverse pressure (integrated pressure) and absorbed power. Two sets of behavioral thresholds were measured in 26 subjects from 0.125 to 20 kHz, with the probe inserted at relatively deep and shallow positions in the ear canal. The greatest dependence on insertion depth was for transmitted pressure and absorbed power. The measures with the least dependence on insertion depth throughout the frequency range (best performance) included the depth-compensated simulator, eardrum, forward, and integrated pressures. Among these, forward pressure is advantageous because it quantifies stimulus phase. PMID:25324079

Diclofenac Suppository as a Preemptive Analgesia in Ultrasound-guided Biopsy of Prostate: Randomized Controlled Trial.

PubMed

Haroon, Naveed; Ather, M Hammad; Khan, Salma; Kumar, Pirkash; Salam, Basit

2015-10-01

To compare preprocedure Diclofenac suppository and Xylocaine gel with Xylocaine gel only in patients undergoing transrectal ultrasound (TRUS)-guided biopsy of prostate for pain. It is a randomized controlled trial conducted on patients undergoing TRUS-guided biopsy for clinical or biochemical suspicion of prostate cancer following a written informed consent and Ethics Review Committee approval. Patients were randomized into 2 groups. Group A included those patients who received Diclofenac suppository 2 hours before in combination with 10 mL of 2% Xylocaine gel 5 minutes before biopsy. Group B received Xylocaine gel only. A visual analog scale was used to measure the pain scores at the time of TRUS probe insertion, just after taking biopsy cores and 2 hours after biopsy. A total of 100 patients were recruited in the study with 50 patients each in group A and B. Mean age of group A was 69.1 ± 10 years and 67.3 ± 8.1 years for group B. The mean pain score for group A and B at the time of probe insertion was 0.08 ± 0.27 and 0.34 ± 0.63 (P = .032), immediately after taking biopsy cores was 1.46 ± 1.15 and 4.68 ± 0.77 (P = .000), and 2 hours after biopsy was 0.14 ± 0.45 vs 2.40 ± 0.81 (P = .000), respectively. The mean pain score at the time of TRUS probe insertion, immediately after taking biopsy cores, and 2 hours after biopsy is statistically significantly higher in group B. Copyright © 2015 Elsevier Inc. All rights reserved.

Methods and instruments for materials testing

NASA Technical Reports Server (NTRS)

Hansma, Paul (Inventor); Drake, Barney (Inventor); Rehn, Douglas (Inventor); Adams, Jonathan (Inventor); Lulejian, Jason (Inventor)

2011-01-01

Methods and instruments for characterizing a material, such as the properties of bone in a living human subject, using a test probe constructed for insertion into the material and a reference probe aligned with the test probe in a housing. The housing is hand held or placed so that the reference probe contacts the surface of the material under pressure applied either by hand or by the weight of the housing. The test probe is inserted into the material to indent the material while maintaining the reference probe substantially under the hand pressure or weight of the housing allowing evaluation of a property of the material related to indentation of the material by the probe. Force can be generated by a voice coil in a magnet structure to the end of which the test probe is connected and supported in the magnet structure by a flexure, opposing flexures, a linear translation stage, or a linear bearing. Optionally, a measurement unit containing the test probe and reference probe is connected to a base unit with a wireless connection, allowing in the field material testing.

Effects of high Z probe on plasma behavior in HT-6M tokamak

NASA Astrophysics Data System (ADS)

Li, J.; Gong, X.; Luo, L.; Yin, F. X.; Noda, N.; Wan, B.; Xu, W.; Gao, X.; Yin, F.; Jiang, J. G.; Wu, Z.; Zhao, J. Y.; Wu, M.; Liu, S.; Han, Y.

1997-02-01

Molybdenum and tungsten probes have been tested in HT-6M tokamak under various discharge conditions aiming to find out the conditions in which high Z PFC can be used without serious degradation of core plasma performance. In normal OH discharges, the degradation of core plasma performance was found only when the probe was inserted beyond 3.0 cm inside the last closed flux surface (LCFS). The plasma performance did not change with positive biasing to the probe, whereas central Te degraded during negative biasing of -100 V. The insertion of the Mo probe to 1.5 cm inside the LCFS made a change in the threshold power of the L-H transition in EOH discharges. These results suggest a certain operation range of the H-mode in the EOH discharge with the Mo probe in HT-6M.

Thermal Design, Analysis, and Testing of the Quench Module Insert Bread Board

NASA Technical Reports Server (NTRS)

Breeding, Shawn; Khodabandeh, Julia

2002-01-01

Contents include the following: Quench Module Insert (QMI) science requirements. QMI interfaces. QMI design layout. QMI thermal analysis and design methodology. QMI bread board testing and instrumentation approach. QMI thermal probe design parameters. Design features for gradient measurement. Design features for heated zone measurements. Thermal gradient analysis results. Heated zone analysis results. Bread board thermal probe layout. QMI bread board correlation and performance. Summary and conclusions.

Molecular cytogenetic mapping of 24 CEPH YACs and 24 gene-specific large insert probes to chromosome 17.

PubMed

Bärlund, M; Nupponen, N N; Karhu, R; Tanner, M M; Paavola, P; Kallioniemi, O P; Kallioniemi, A

1998-01-01

Defining boundaries of chromosomal rearrangements at the molecular level would benefit from landmarks that link the cytogenetic map to physical, genetic, and transcript maps, as well as from large-insert FISH probes for such loci to detect numerical and structural rearrangements in metaphase or interphase cells. Here, we determined the locations of 24 genetically mapped CEPH-Mega YACs along the FLpter scale (fractional length from p-telomere) by quantitative fluorescence in situ hybridization analysis. This generated a set of cytogenetically mapped probes for chromosome 17 with an average spacing of about 5 cM. We then developed large-insert YAC, BAC, PAC, or P1 clones to the following 24 known genes, and determined refined map locations along the same FLpter scale: pter-TP53-TOP3-cen-TNFAIP1-ERBB2-TOP2A- BRCA1-TCF11-NME1-HLF-ZNF147/CL N80-BCL5/MPO/SFRS1-TBX2-PECAM1-DDX5/ PRKCA-ICAM2-GH1/PRKAR1A-GRB2-CDK3 /FKHL13-qter. Taken together, these 48 cytogenetically mapped large-insert probes provide tools for the molecular analysis of chromosome 17 rearrangements, such as mapping amplification, deletion, and translocation breakpoints in this chromosome, in cancer and other diseases.

Tn5099, a xylE promoter probe transposon for Streptomyces spp.

PubMed Central

Hahn, D R; Solenberg, P J; Baltz, R H

1991-01-01

Tn5099, a promoter probe transposon for Streptomyces spp., was constructed by inserting a promoterless xylE gene and a hygromycin resistance gene into IS493. Tn5099 transposed into different sites in the Streptomyces griseofuscus genome, and the xylE reporter gene was expressed in some of the transposition mutants. Strains containing Tn5099 insertions that gave regulated expression of the xylE gene were identified. Images PMID:1653213

Effect of plastic-covered ultrasonic scalers on titanium implant surfaces.

PubMed

Mann, M; Parmar, D; Walmsley, A D; Lea, S C

2012-01-01

Maintaining oral health around titanium implants is essential. The formation of a biofilm on the titanium surface will influence the continuing success of the implant. These concerns have led to modified ultrasonic scaler instruments that look to reduce implant damage while maximising the cleaning effect. This study aimed to assess the effect of instrumentation, with traditional and modified ultrasonic scalers, on titanium implant surfaces and to correlate this with the oscillations of the instruments. Two ultrasonic insert designs (metallic TFI-10 and a plastic-tipped implant insert) were selected. Each scaler probe was scanned using a scanning laser vibrometer, under loaded and unloaded conditions, to determine their oscillation characteristics. Loads were applied against a titanium implant (100g and 200 g) for 10 s. The resulting implant surfaces were then scanned using laser profilometry and scanning electron microscopy (SEM). Insert probes oscillated with an elliptical motion with the maximum amplitude at the probe tip. Laser profilometry detected defects in the titanium surface only for the metallic scaler insert. Defect widths at 200 g high power were significantly larger than all other load/power conditions (P<0.02). Using SEM, it was observed that modifications to the implant surface had occurred following instrumentation with the plastic-tipped insert. Debris was also visible around the defects. Metal scalers produce defects in titanium implant surfaces and load and power are important factors in the damage caused. Plastic-coated scaler probes cause minimal damage to implant surfaces and have a polishing action but can leave plastic deposits behind on the implant surface. © 2011 John Wiley & Sons A/S.

In-plane ultrasonic needle tracking using a fiber-optic hydrophone

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

Xia, Wenfeng, E-mail: wenfeng.xia@ucl.ac.uk; Desjardins, Adrien E.; Mari, Jean Martial

Purpose: Accurate and efficient guidance of needles to procedural targets is critically important during percutaneous interventional procedures. Ultrasound imaging is widely used for real-time image guidance in a variety of clinical contexts, but with this modality, uncertainties about the location of the needle tip within the image plane lead to significant complications. Whilst several methods have been proposed to improve the visibility of the needle, achieving accuracy and compatibility with current clinical practice is an ongoing challenge. In this paper, the authors present a method for directly visualizing the needle tip using an integrated fiber-optic ultrasound receiver in conjunction withmore » the imaging probe used to acquire B-mode ultrasound images. Methods: Needle visualization and ultrasound imaging were performed with a clinical ultrasound imaging system. A miniature fiber-optic ultrasound hydrophone was integrated into a 20 gauge injection needle tip to receive transmissions from individual transducer elements of the ultrasound imaging probe. The received signals were reconstructed to create an image of the needle tip. Ultrasound B-mode imaging was interleaved with needle tip imaging. A first set of measurements was acquired in water and tissue ex vivo with a wide range of insertion angles (15°–68°) to study the accuracy and sensitivity of the tracking method. A second set was acquired in an in vivo swine model, with needle insertions to the brachial plexus. A third set was acquired in an in vivo ovine model for fetal interventions, with insertions to different locations within the uterine cavity. Two linear ultrasound imaging probes were used: a 14–5 MHz probe for the first and second sets, and a 9–4 MHz probe for the third. Results: During insertions in tissue ex vivo and in vivo, the imaged needle tip had submillimeter axial and lateral dimensions. The signal-to-noise (SNR) of the needle tip was found to depend on the insertion angle. With the needle tip in water, the SNR of the needle tip varied with insertion angle, attaining values of 284 at 27° and 501 at 68°. In swine tissue ex vivo, the SNR decreased from 80 at 15° to 16 at 61°. In swine tissue in vivo, the SNR varied with depth, from 200 at 17.5 mm to 48 at 26 mm, with a constant insertion angle of 40°. In ovine tissue in vivo, within the uterine cavity, the SNR varied from 46.4 at 25 mm depth to 18.4 at 32 mm depth, with insertion angles in the range of 26°–65°. Conclusions: A fiber-optic ultrasound receiver integrated into the needle cannula in combination with single-element transmissions from the imaging probe allows for direct visualization of the needle tip within the ultrasound imaging plane. Visualization of the needle tip was achieved at depths and insertion angles that are encountered during nerve blocks and fetal interventions. The method presented in this paper has strong potential to improve the safety and efficiency of ultrasound-guided needle insertions.« less

The Rectal Administration of Lignocaine Gel and Periprostatic Lignocaine Infiltration During Transrectal Ultrasound-Guided Prostate Biopsy Provides Effective Analgesia

PubMed Central

Siddiqui, EJ; Ali, S; Koneru, S

2006-01-01

INTRODUCTION Transrectal ultrasound guided prostate needle biopsy (TRUS) is the standard procedure to diagnose or exclude prostate cancer. This procedure can be associated with significant discomfort, both on insertion of the ultrasound probe as well as on taking the biopsy. We evaluated a new technique for pain relief during TRUS biopsy. PATIENTS AND METHODS In Group 1 (n = 60), the biopsies were taken without any analgesia. In Group 2 (n = 60), 11 ml of Instillagel (2% lignocaine) was administered rectally prior to probe insertion and 5 ml of 1% lignocaine periprostatic injection was administered before taking the biopsy. The discomfort encountered during the procedure was graded by the patient on a scale ranging from no discomfort to mild, moderate and severe pain. RESULTS In Group 2, there was a marked reduction in the pain experienced during the procedure. The Chi-squared test for trend showed a significant association between the rectal administration of local anaesthetic gel and reduction in pain on probe insertion (P = 0.0001). There was also a significant association between the use of periprostatic lignocaine injection and reduction in pain on taking the biopsy (P < 0.0001). CONCLUSIONS The use of lignocaine gel prior to probe insertion and periprostatic infiltration of lignocaine before taking the needle biopsy significantly reduces the pain experienced by the patient during TRUS-guided prostate biopsy. PMID:16551424

A Coaxial Dual-element Focused Ultrasound Probe for Guidance of Epidural Catheterization: An Experimental Study.

PubMed

Dong, Guo-Chung; Chiu, Li-Chen; Ting, Chien-Kun; Hsu, Jia-Ruei; Huang, Chih-Chung; Chang, Yin; Chen, Gin-Shin

2017-09-01

Ultrasound guidance for epidural block has improved clinical blind-trial problems but the design of present ultrasonic probes poses operating difficulty of ultrasound-guided catheterization, increasing the failure rate. The purpose of this study was to develop a novel ultrasonic probe to avoid needle contact with vertebral bone during epidural catheterization. The probe has a central circular passage for needle insertion. Two focused annular transducers are deployed around the passage for on-axis guidance. A 17-gauge insulated Tuohy needle containing the self-developed fiber-optic-modified stylet was inserted into the back of the anesthetized pig, in the lumbar region under the guidance of our ultrasonic probe. The inner transducer of the probe detected the shallow echo signals of the peak-peak amplitude of 2.8 V over L3 at the depth of 2.4 cm, and the amplitude was decreased to 0.8 V directly over the L3 to L4 interspace. The outer transducer could detect the echoes from the deeper bone at the depth of 4.5 cm, which did not appear for the inner transducer. The operator tilted the probe slightly in left-right and cranial-caudal directions until the echoes at the depth of 4.5 cm disappeared, and the epidural needle was inserted through the central passage of the probe. The needle was advanced and stopped when the epidural space was identified by optical technique. The needle passed without bone contact. Designs of the hollow probe for needle pass and dual transducers with different focal lengths for detection of shallow and deep vertebrae may benefit operation, bone/nonbone identification, and cost.

Cervix-to-rectum measuring device in a radiation applicator for use in the treatment of cervical cancer

NASA Technical Reports Server (NTRS)

Fischell, D. R.; Mazique, J. C. (Inventor)

1981-01-01

A cervix-to-rectum measuring device to be used in the treatment of cervical cancer is described. It includes a handle and a probe pivotably connected to the handle for insertion in the rectum. The measuring device further includes means for coupling the handle to an intrauterine radiation applicator when the latter is positioned in the uterine cervix and the probe is inserted in the rectum to pivot the handle about the probe. A gear is provided which is adapted to pivot with the probe. A pinion pivotably connected to the handle meshes with the gear. A pointer fixed to the pinion is displaced in response to the pivoting of the handle about the probe, and this displacement can be read from a scale on the handle, providing an indication of the cervix-to-rectum distance.

Estimating needle tip deflection in biological tissue from a single transverse ultrasound image: application to brachytherapy.

PubMed

Rossa, Carlos; Sloboda, Ron; Usmani, Nawaid; Tavakoli, Mahdi

2016-07-01

This paper proposes a method to predict the deflection of a flexible needle inserted into soft tissue based on the observation of deflection at a single point along the needle shaft. We model the needle-tissue as a discretized structure composed of several virtual, weightless, rigid links connected by virtual helical springs whose stiffness coefficient is found using a pattern search algorithm that only requires the force applied at the needle tip during insertion and the needle deflection measured at an arbitrary insertion depth. Needle tip deflections can then be predicted for different insertion depths. Verification of the proposed method in synthetic and biological tissue shows a deflection estimation error of [Formula: see text]2 mm for images acquired at 35 % or more of the maximum insertion depth, and decreases to 1 mm for images acquired closer to the final insertion depth. We also demonstrate the utility of the model for prostate brachytherapy, where in vivo needle deflection measurements obtained during early stages of insertion are used to predict the needle deflection further along the insertion process. The method can predict needle deflection based on the observation of deflection at a single point. The ultrasound probe can be maintained at the same position during insertion of the needle, which avoids complications of tissue deformation caused by the motion of the ultrasound probe.

Flexible deep brain neural probes based on a parylene tube structure

NASA Astrophysics Data System (ADS)

Zhao, Zhiguo; Kim, Eric; Luo, Hao; Zhang, Jinsheng; Xu, Yong

2018-01-01

Most microfabricated neural probes have limited shank length, which prevents them from reaching many deep brain structures. This paper reports deep brain neural probes with ultra-long penetrating shanks based on a simple but novel parylene tube structure. The mechanical strength of the parylene tube shank is temporarily enhanced during implantation by inserting a metal wire. The metal wire can be removed after implantation, making the implanted probe very flexible and thus minimizing the stress caused by micromotions of brain tissues. Optogenetic stimulation and chemical delivery capabilities can be potentially integrated by taking advantage of the tube structure. Single-shank prototypes with a shank length of 18.2 mm have been developed. The microfabrication process comprises of deep reactive ion etching (DRIE) of silicon, parylene conformal coating/refilling, and XeF2 isotropic silicon etching. In addition to bench-top insertion characterization, the functionality of developed probes has been preliminarily demonstrated by implanting into the amygdala of a rat and recording neural signals.

Fiber-optic temperature probe system for inner body

NASA Astrophysics Data System (ADS)

Liu, Bo; Deng, Xing-Zhong; Cao, Wei; Cheng, Xianping; Xie, Tuqiang; Zhong, Zugen

1991-08-01

The authors have designed a fiber-optic temperature probe system that can quickly insert its probe into bodies to measure temperature. Its thermometer unit has the function of program- controlled zeroing. The single-chip microcomputer is used to control the whole system and process data. The sample system has been tested in a coal furnace.

16 CFR 1505.51 - Hot surfaces.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

16 CFR 1505.51 - Hot surfaces.

Code of Federal Regulations, 2014 CFR

2014-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

16 CFR 1505.51 - Hot surfaces.

Code of Federal Regulations, 2012 CFR

2012-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

Deep Space Network capabilities for receiving weak probe signals

NASA Technical Reports Server (NTRS)

Asmar, Sami; Johnston, Doug; Preston, Robert

2004-01-01

This paper will describe the capability and highlight the cases of the critical communications for the Mars rovers and Saturn Orbit Insertion and preparation radio tracking of the Huygens probe at (non-DSN) radio telescopes.

Aligning Plasma-Arc Welding Oscillations

NASA Technical Reports Server (NTRS)

Norris, Jeff; Fairley, Mike

1989-01-01

Tool aids in alignment of oscillator probe on variable-polarity plasma-arc welding torch. Probe magnetically pulls arc from side to side as it moves along joint. Tensile strength of joint depends on alignment of weld bead and on alignment of probe. Operator installs new tool on front of torch body, levels it with built-in bubble glass, inserts probe in slot on tool, and locks probe in place. Procedure faster and easier and resulting alignment more accurate and repeatable.

Using SINEs to probe ancient explosive speciation: "hidden" radiation of African cichlids?

PubMed

Terai, Yohey; Takahashi, Kazuhiko; Nishida, Mutsumi; Sato, Tetsu; Okada, Norihiro

2003-06-01

Cichlid fishes of the east African Great Lakes represent a paradigm of adaptive radiation. We conducted a phylogenetic analysis of cichlids including pan-African and west African species by using insertion patterns of short interspersed elements (SINEs) at orthologous loci. The monophyly of the east African cichlids was consistently supported by seven independent insertions of SINE sequences that are uniquely shared by these species. In addition, data from four other loci indicated that the genera Tilapia (pan-African) and Steatocranus (west African) are the closest relatives to east African cichlids. However, relationships among Tilapia, Steatocranus, and the east African clade were ambiguous because of incongruencies among topologies suggested by insertion patterns of SINEs at six other loci. One plausible explanation for this phenomenon is incomplete lineage sorting of alleles containing or missing a SINE insertion at these loci during ancestral speciation. Such incomplete sorting may have taken place earlier than 14 MYA, followed by random and stochastic fixation of the alleles in subsequent lineages. These observations prompted us to consider the possibility that cichlid speciation occurred at an accelerated rate during this period when the African Great Lakes did not exist. The SINE method could be useful for detecting ancient exclusive speciation events that tend to remain hidden during conventional sequence analyses because of accumulated point mutations.

16 CFR § 1505.51 - Hot surfaces.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

Deep Space Network Capabilities for Receiving Weak Probe Signals

NASA Technical Reports Server (NTRS)

Asmar, Sami; Johnston, Doug; Preston, Robert

2005-01-01

Planetary probes can encounter mission scenarios where communication is not favorable during critical maneuvers or emergencies. Launch, initial acquisition, landing, trajectory corrections, safing. Communication challenges due to sub-optimum antenna pointing or transmitted power, amplitude/frequency dynamics, etc. Prevent lock-up on signal and extraction of telemetry. Examples: loss of Mars Observer, nutation of Ulysses, Galileo antenna, Mars Pathfinder and Mars Exploration Rovers Entry, Descent, and Landing, and the Cassini Saturn Orbit Insertion. A Deep Space Network capability to handle such cases has been used successfully to receive signals to characterize the scenario. This paper will describe the capability and highlight the cases of the critical communications for the Mars rovers and Saturn Orbit Insertion and preparation radio tracking of the Huygens probe at (non-DSN) radio telescopes.

Accuracy of a dynamic surgical guidance probe for screw insertion in the cervical spine: a cadaveric study.

PubMed

Dixon, Daniel; Darden, Bruce; Casamitjana, Jose; Weissmann, Karen A; Cristobal, San; Powell, David; Baluch, Daniel

2017-04-01

A fresh frozen cadaver study was conducted. To report the cortical breach rate using the dynamic surgical guidance (DSG) probe versus traditional freehand technique for cervical lateral mass, cervical pedicle and cervical laminar screws. Nine male fresh frozen cadaveric torsos were utilized for this study. Each investigator was assigned three specimens that were randomized by fixation point, side and order of technique for establishing a screw pilot hole. The technique for screw hole preparation utilized was either a DSG probe in the "on" mode or in the "off" mode using a freehand technique popularized by Lenke et al. Levels instrumented included C1 lateral mass, C2 pedicle screws and lamina screws, and C6-T1 pedicle screws. Fluoroscopy and other navigational assistance were not used for screw hole preparation or screw insertion. All specimens were CT imaged following insertion of all screws. A senior radiologist evaluated all scans and determined that a misplaced screw was a breach of ≥2 mm. A total of 104 drillings were performed, 52 with DSG and 52 without DSG There were 68 total pedicle drillings, 34 in each group. There were 18 drillings in the lamina and lateral mass. There was no significant difference between surgeons or between the left and right side. All breaches were in the pedicle, and none in the lamina or lateral mass. The breach rate for PG "on" was 6/68 = 8.96% (95% CI 3.69, 19.12%). The breach rate for PG "off" was 20/68 = 29.41% (95% CI 19.30, 41.87%). Of the 20 pedicle breaches in the non-DSG group, 7 were lateral and superior, 8 were lateral, 4 medial and 1 inferior. Of the six pedicle breaches in the DSG group, two were lateral/superior, two were lateral and two were medial in the pedicle. The dynamic surgical guidance probe is a safe tool to assist the surgeon with screw placement in the cervical spine. Additionally, the DSG potentially avoids the cumulative risks associated with fluoroscopy and provides real-time feedback to the surgeon allowing correction at the time of breach. Level of evidence Level IV.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Thermally induced optical damage to barium-sodium niobate crystals

NASA Astrophysics Data System (ADS)

Baryshev, S. A.; Goncharova, I. F.; Konvisar, P. G.; Kuznetsov, V. A.

1990-06-01

Thermally induced optical damage (TIOD) was observed in undoped barium-sodium niobate (BSN) crystals as a result of changes in their temperature. This damage was deduced from the behavior of YAG:Nd3+ laser radiation when a BSN crystal was inserted in the resonator and also using a helium-neon laser probe beam. The experimental results were satisfactorily explained by the familiar pyroelectric model of TIOD and, in the crystals studied, an inhomogeneity of the conductivity rather than an inhomogeneity of the pyroelectric constant played the main role.

Comparison of different local anesthesia techniques during TRUS-guided biopsies: a prospective pilot study.

PubMed

Kravchick, Sergey; Peled, Ronit; Ben-Dor, David; Dorfman, Dov; Kesari, David; Cytron, Shmuel

2005-01-01

To introduce two forms of anesthesia and compare them with standard local anesthesia techniques. A total of 114 consecutive patients underwent prostate needle biopsy. The patients were sequentially randomized to receive different kinds of anesthesia: 2% rectal lidocaine gel, 40% dimethyl sulfoxide (DMSO) with lidocaine, perianal injection of 1% lidocaine, or periprostatic nerve block. Pain perception was separately assessed for probe insertion and biopsies using a visual pain analog score. One-way analysis of variance was used to compare the data scale among the four groups. A linear regression model was used to define the independent variables that predicted the level of pain. The groups were similar in terms of age, prostate-specific antigen levels, digital rectal examination findings, prostate volume, pain tolerance, biopsy time, and number of cores taken. The lowest pain scores for probe insertion were for the perianal injection and DMSO/lidocaine groups (0.89 and 1.38, respectively). The difference between these scores and those for the other two groups was statistically significant (P <0.001). Pain perception during biopsy did not differ significantly among the DMSO/lidocaine, perianal, or periprostatic groups and was greatest in the lidocaine gel group (4.147; P <0.001). We did not observe any statistically significant correlation between the pain level during probe insertion and biopsy and pain tolerance (P = 0.514 and P = 0.788, respectively). The anesthesia type was the strongest single predictor of the pain level during biopsy (P <0.001). The use of 40% DMSO with lidocaine instilled into the rectal vault for 10 minutes avoids any need for injection and is capable of decreasing the discomfort or pain experienced during probe insertion and prostate biopsy comparable to the perianal and periprostatic protocols.

Use of radioactive sources in measuring characteristics of snowpacks

Treesearch

Henry W. Anderson; Philip M. McDonald; Lloyd W. Gay

1963-01-01

Use of radioactive probes inserted in mountain snowpacks may make possible more accurate appraisal and prediction of snowmelt water. Commercially available gamma and neutron probes were tested for their ability to measure snow density, ice lenses, and the thermal quality of individual layers in the snowpack.

Charge-tagged ligands: useful tools for immobilising complexes and detecting reaction species during catalysis

PubMed Central

Limberger, Jones; Leal, Bárbara C.; Monteiro, Adriano L.

2015-01-01

In recent years, charge-tagged ligands (CTLs) have become valuable tools in organometallic catalysis. Insertion of an ionic side chain into the molecular skeleton of a known ligand has become a useful protocol for anchoring ligands, and consequently catalysts, in polar and ionic liquid phases. In addition, the insertion of a cationic moiety into a ligand is a powerful tool that can be used to detect reaction intermediates in organometallic catalysis through electrospray ionisation mass spectrometry (ESI-MS) experiments. The insertion of an ionic tag ensures the charge in the intermediates independently of the ESI-MS. For this reason, these ligands have been used as ionic probes in mechanistic studies for several catalytic reactions. Here, we summarise selected examples on the use of CTLs as immobilising agents in organometallic catalysis and as probes for studying mechanisms through ESI-MS. PMID:28553458

Long-term stability of intracortical recordings using perforated and arrayed Parylene sheath electrodes

NASA Astrophysics Data System (ADS)

Hara, Seth A.; Kim, Brian J.; Kuo, Jonathan T. W.; Lee, Curtis D.; Meng, Ellis; Pikov, Victor

2016-12-01

Objective. Acquisition of reliable and robust neural recordings with intracortical neural probes is a persistent challenge in the field of neuroprosthetics. We developed a multielectrode array technology to address chronic intracortical recording reliability and present in vivo recording results. Approach. The 2 × 2 Parylene sheath electrode array (PSEA) was microfabricated and constructed from only Parylene C and platinum. The probe includes a novel three-dimensional sheath structure, perforations, and bioactive coatings that improve tissue integration and manage immune response. Coatings were applied using a sequential dip-coating method that provided coverage over the entire probe surface and interior of the sheath structure. A sharp probe tip taper facilitated insertion with minimal trauma. Fabricated probes were subject to examination by optical and electron microscopy and electrochemical testing prior to implantation. Main results. 1 × 2 arrays were successfully fabricated on wafer and then packaged together to produce 2 × 2 arrays. Then, probes having electrode sites with adequate electrochemical properties were selected. A subset of arrays was treated with bioactive coatings to encourage neuronal growth and suppress inflammation and another subset of arrays was implanted in conjunction with a virally mediated expression of Caveolin-1. Arrays were attached to a custom-made insertion shuttle to facilitate precise insertion into the rat motor cortex. Stable electrophysiological recordings were obtained during the period of implantation up to 12 months. Immunohistochemical evaluation of cortical tissue around individual probes indicated a strong correlation between the electrophysiological performance of the probes and histologically observable proximity of neurons and dendritic sprouting. Significance. The PSEA demonstrates the scalability of sheath electrode technology and provides higher electrode count and density to access a greater volume for recording. This study provided support for the importance of creating a supportive biological environment around the probes to promote the long-term electrophysiological performance of flexible probes in the cerebral cortex. In particular, we demonstrated beneficial effects of the Matrigel coating and the long-term expression of Caveolin-1. Furthermore, we provided support to an idea of using an artificial acellular tissue compartment as a way to counteract the walling-off effect of the astrocytic scar formation around the probes as a means of establishing a more intimate and stable neural interface.

Finite Element Modelling of the Apollo Heat Flow Experiments

NASA Astrophysics Data System (ADS)

Platt, J.; Siegler, M. A.; Williams, J.

2013-12-01

The heat flow experiments sent on Apollo missions 15 and 17 were designed to measure the temperature gradient of the lunar regolith in order to determine the heat flux of the moon. Major problems in these experiments arose from the fact that the astronauts were not able to insert the probes below the thermal skin depth. Compounding the problem, anomalies in the data have prevented scientists from conclusively determining the temperature dependent conductivity of the soil, which enters as a linear function into the heat flow calculation, thus stymieing them in their primary goal of constraining the global heat production of the Moon. Different methods of determining the thermal conductivity have yielded vastly different results resulting in downward corrections of up to 50% in some cases from the original calculations. Along with problems determining the conductivity, the data was inconsistent with theoretical predictions of the temperature variation over time, leading some to suspect that the Apollo experiment itself changed the thermal properties of the localised area surrounding the probe. The average temperature of the regolith, according to the data, increased over time, a phenomenon that makes calculating the thermal conductivity of the soil and heat flux impossible without knowing the source of error and accounting for it. The changes, possibly resulting from as varied sources as the imprint of the Astronauts boots on the lunar surface, compacted soil around the bore stem of the probe or even heat radiating down the inside of the tube, have convinced many people that the recorded data is unusable. In order to shed some light on the possible causes of this temperature rise, we implemented a finite element model of the probe using the program COMSOL Multi-physics as well as Matlab. Once the cause of the temperature rise is known then steps can be taken to account for the failings of the experiment and increase the data's utility.

Effects of FlAsH/Tetracysteine (TC) tag on PrP proteolysis and PrPres formation by TC-scanning

PubMed Central

Taguchi, Yuzuru; Hohsfield, Lindsay A.; Hollister, Jason R.

2014-01-01

The FlAsH/tetracysteine (FlAsH/TC) tag is a powerful tool for fluorescent labeling of proteins. However, even small tags such as FlAsH/TC could alter the behavior of the tagged proteins, especially if the insertion occurs at internal sites. Defining the influence of FlAsH/TC on nearby protein-protein interactions might aid in selecting appropriate positions for internal TC insertions and allow the exploitation of serial FlAsH/TC insertions (TC-scanning) as a probe to characterize sites of protein-protein interaction. To explore this application in the context of substrate-protease interactions, we analyzed the effect of FlAsH/TC insertions on proteolysis of cellular prion protein (PrPsen) in in vitro reactions and generation of the C1 metabolic fragment of PrPsen in live neuroblastoma cells. The influence of FlAsH/TC insertion was evaluated by TC-scanning across the cleavage sites of each protease. The results showed that FlAsH/TC inhibited protease cleavage only within limited ranges of the cleavage sites that varied from about 1 to 6 residues-wide depending on the protease, providing an estimate of the PrP residues interacting with each protease. TC-scanning was also used to probe a different type of protein-protein interaction, the conformational conversion of FlAsH-PrPsen to the prion disease-associated isoform, PrPres. PrP constructs with FlAsH/TC insertions at residues 90–96 but not 97–101 were converted to FlAsH-PrPres, identifying a boundary separating loosely versus compactly folded regions of PrPres. Our observations demonstrate that TC-scanning with the FlAsH/TC tag can be a versatile method for probing protein-protein interactions and folding processes. PMID:23943295

Efficacy of functional electrical stimulation-biofeedback with sexual cognitive-behavioral therapy as treatment of vaginismus.

PubMed

Seo, Ju Tae; Choe, Jin Ho; Lee, Won Sik; Kim, Kyung Hee

2005-07-01

To report 12 cases of vaginismus that were successfully treated with functional electrical stimulation (FES)-biofeedback with sexual cognitive-behavioral therapy (SCBT) to determine the efficacy of FES-biofeedback with SCBT as a standard therapy for vaginismus. Vaginismus is an involuntary spasm of the musculature of the outer third of the vagina that leads to impossible vaginal penetration, causing personal distress. Various therapeutic approaches, both physiologic and psychological, have been considered. Twelve women with vaginismus referred from a checkup outpatient clinic participated in this study. The patients enrolled in this study had vaginismus according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders. The patients were assessed before and after treatment with gynecologic examinations and structured interviews pertaining to sexual function and psychological adjustment. After the diagnosis of vaginismus, we conducted weekly pelvic floor muscle relaxation using FES-biofeedback. Once the patients became tolerable to vaginal manipulation, the eight-stage SCBT (eight-stage gradual desensitization described by Kaplan using vaginal self-dilation with fingers and vaginal probe insertion) was added for 8 weeks. After 8 weeks of treatment, all 12 couples had completed the program, had become tolerable to vaginal insertion of larger size probes, and could achieve satisfactory vaginal intercourse. FES-biofeedback with SCBT is an effective aid for patients with vaginismus to learn muscle control. Therefore, it may increase the success rate of treatment of vaginismus.

A fluorescent probe for ecstasy.

PubMed

Masseroni, D; Biavardi, E; Genovese, D; Rampazzo, E; Prodi, L; Dalcanale, E

2015-08-18

A nanostructure formed by the insertion in silica nanoparticles of a pyrene-derivatized cavitand, which is able to specifically recognize ecstasy in water, is presented. The absence of effects from interferents and an efficient electron transfer process occurring after complexation of ecstasy, makes this system an efficient fluorescent probe for this popular drug.

SESAME/CASSE listening to the insertion of the MUPUS PEN at Abydos site, 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Knapmeyer, M.; Fischer, H.-H.; Knollenberg, J.; Seidensticker, K. J.; Thiel, K.; Arnold, W.; Faber, C.; Möhlmann, D.

2015-10-01

SESAME is a suite of three instruments (the Comet Acoustic Surface Sounding Experiment CASSE, the Dust Impact Monitor DIM, and the electrical Permittivity Probe PP) that have sensors and transmitters distributed all over the Philae lander, but share common electronics for commanding and processing. SESAME is conducted by a consortium of DLR, the Max Planck Institute for Solar System Research (Göttingen), and the Finnish Meteorological Institute (Helsinki, [1]). The Multi-Purpose Sensor MUPUS, run also by DLR, combines a thermal conductivity and heat flow experiment with a mechanical properties experiment associated with the anchoring harpoons of the lander ([2]). It was recognized early in the preparation of both the SESAME and MUPUS experiments that the hammering mechanism of the latter, which drives the thermal probe into the ground, might as well serve as source of elastic waves for the CASSE experiment. To support the CASSE experiment, the MUPUS flight software provides information on its hammering process in a shared memory of the lander data management system. CASSE listening to the MUPUS PEN hammer mechanism proved to be the first active seismic experiment conducted on a celestial body other than Earth since the Lunar Seismic Profiling Experiment, which was carried out on the Moon by the Apollo 17 astronauts in 1972 (e.g. [3]).

How does a probe inserted into the discharge influence the plasma structure?

NASA Astrophysics Data System (ADS)

Yordanov, D.; Lishev, St.; Shivarova, A.

2016-05-01

Shielding the bias applied to the probe by the sheath formed around it and determination of parameters of unperturbed plasmas are in the basis of the probe diagnostics. The results from a two-dimensional model of a discharge with a probe inserted in it show that the probe influences the spatial distribution of the plasma parameters in the entire discharge. The increase (although slight) in the electron temperature, due to the increased losses of charged particles on the additional wall in the discharge (mainly the probe holder), leads to redistribution of the plasma density and plasma potential, as shown by the results obtained at the floating potential of the probe. The deviations due to the bias applied to the probe tip are stronger in the ion saturation region of the probe characteristics. The pattern of the spatial redistribution of the plasma parameters advances together with the movement of the probe deeper in the discharge. Although probe sheaths and probe characteristics resulting from the model are shown, the study does not aim at discussions on the theories for determination of the plasma density from the ion saturation current. Regardless of the modifications in the plasma behavior in the entire discharge, the deviations of the plasma parameters at the position of the probe tip and, respectively, the uncertainty which should be added as an error when the accuracy of the probe diagnostics is estimated do not exceed 10%. Consequently, the electron density and temperature obtained, respectively, at the position of the plasma potential on the probe characteristics and from its transition region are in reasonable agreement with the results from the model of the discharge without a probe. Being in the scope of research on a source of negative hydrogen ions with the design of a matrix of small radius inductive discharges, the model is specified for a low-pressure hydrogen discharge sustained in a small-radius tube.

[Wrong connection of a flexible medical air hose to a nitrous oxide outlet caused by a defective safety device].

PubMed

Nicaise, C; Robert, C; Ancellin, J; Cazalaà, J B

1996-01-01

When plugging the O2, N2O and air hoses into the corresponding wall sockets, the air hose was wrongly inserted into the N2O wall outlet. This was made possible because of faulty retaining clasps of the male coupler of the air probe. French "fail-safe" connections consist of a two-clasp male coupler for air, three clasps for O2 and four clasps for N2O hoses. Additionally the clasps of the air probe are broader then those of the N2O probe. However, the latter difference was lost due to wear. The incident was recognized without delay as the N2O hose could not be inserted into the air outlet. However, it could have remained unnoticed had there been two N2O wall outlets and could have resulted in severe adverse effects.

Determination of medium electrical properties through full-wave modelling of frequency domain reflectrometry data

NASA Astrophysics Data System (ADS)

André, Frédéric; Lambot, Sébastien

2015-04-01

Accurate knowledge of the shallow soil properties is of prime importance in agricultural, hydrological and environmental engineering. During the last decade, numerous geophysical techniques, either invasive or resorting to proximal or remote sensing, have been developed and applied for quantitative characterization of soil properties. Amongst them, time domain reflectrometry (TDR) and frequency domain reflectometry (FDR) are recognized as standard techniques for the determination of soil dielectric permittivity and electrical conductivity, based on the reflected electromagnetic waves from a probe inserted into the soil. TDR data were first commonly analyzed in the time domain using methods considering only a part of the waveform information. Later, advancements have led to the possibility of analyzing the TDR signal through full-wave inverse modeling either in the time or the frequency domains. A major advantage of FDR compared to TDR is the possibility to increase the bandwidth, thereby increasing the information content of the data and providing more detailed characterization of the medium. Amongst the recent works in this field, Minet et al. (2010) developed a modeling procedure for processing FDR data based on an exact solution of Maxwell's equations for wave propagation in one-dimensional multilayered media. In this approach, the probe head is decoupled from the medium and is fully described by characteristic transfer functions. The authors successfully validated the method for homogeneous sand subject to a range of water contents. In the present study, we further validated the modelling approach using reference liquids with well-characterized frequency-dependent electrical properties. In addition, the FDR model was coupled with a dielectric mixing model to investigate the ability of retrieving water content, pore water electrical conductivity and sand porosity from inversion of FDR data acquired in sand subject to different water content levels. Finally, the possibility of reconstructing the vertical profile of the properties by inversion of FDR data collected during progressive insertion of the probe into a vertically heterogeneous medium was also investigated. Index Terms: Frequency domain reflectrometry (FDR), frequency dependence, dielectric permittivity, electrical conductivity Reference: Minet J., Lambot S., Delaide G., Huisman J.A., Vereecken H., Vanclooster M., 2010. A generalized frequency domain reflectometry modeling technique for soil electrical properties determination. Vadose Zone Journal, 9: 1063-1072.

REDOR solid-state NMR as a probe of the membrane locations of membrane-associated peptides and proteins

NASA Astrophysics Data System (ADS)

Jia, Lihui; Liang, Shuang; Sackett, Kelly; Xie, Li; Ghosh, Ujjayini; Weliky, David P.

2015-04-01

Rotational-echo double-resonance (REDOR) solid-state NMR is applied to probe the membrane locations of specific residues of membrane proteins. Couplings are measured between protein 13CO nuclei and membrane lipid or cholesterol 2H and 31P nuclei. Specific 13CO labeling is used to enable unambiguous assignment and 2H labeling covers a small region of the lipid or cholesterol molecule. The 13CO-31P and 13CO-2H REDOR respectively probe proximity to the membrane headgroup region and proximity to specific insertion depths within the membrane hydrocarbon core. One strength of the REDOR approach is use of chemically-native proteins and membrane components. The conventional REDOR pulse sequence with 100 kHz 2H π pulses is robust with respect to the 2H quadrupolar anisotropy. The 2H T1's are comparable to the longer dephasing times (τ's) and this leads to exponential rather than sigmoidal REDOR buildups. The 13CO-2H buildups are well-fitted to A × (1 - e-γτ) where A and γ are fitting parameters that are correlated as the fraction of molecules (A) with effective 13CO-2H coupling d = 3γ/2. The REDOR approach is applied to probe the membrane locations of the "fusion peptide" regions of the HIV gp41 and influenza virus hemagglutinin proteins which both catalyze joining of the viral and host cell membranes during initial infection of the cell. The HIV fusion peptide forms an intermolecular antiparallel β sheet and the REDOR data support major deeply-inserted and minor shallowly-inserted molecular populations. A significant fraction of the influenza fusion peptide molecules form a tight hairpin with antiparallel N- and C-α helices and the REDOR data support a single peptide population with a deeply-inserted N-helix. The shared feature of deep insertion of the β and α fusion peptide structures may be relevant for fusion catalysis via the resultant local perturbation of the membrane bilayer. Future applications of the REDOR approach may include samples that contain cell membrane extracts and use of lower temperatures and dynamic nuclear polarization to reduce data acquisition times.

Evaluating the in vivo glial response to miniaturized parylene cortical probes coated with an ultra-fast degrading polymer to aid insertion

NASA Astrophysics Data System (ADS)

Lo, Meng-chen; Wang, Shuwu; Singh, Sagar; Damodaran, Vinod B.; Ahmed, Ijaz; Coffey, Kevin; Barker, David; Saste, Kshitij; Kals, Karanvir; Kaplan, Hilton M.; Kohn, Joachim; Shreiber, David I.; Zahn, Jeffrey D.

2018-06-01

Objective. Despite the feasibility of short-term neural recordings using implantable microelectrodes, attaining reliable, chronic recordings remains a challenge. Most neural recording devices suffer from a long-term tissue response, including gliosis, at the device–tissue interface. It was hypothesized that smaller, more flexible intracortical probes would limit gliosis by providing a better mechanical match with surrounding tissue. Approach. This paper describes the in vivo evaluation of flexible parylene microprobes designed to improve the interface with the adjacent neural tissue to limit gliosis and thereby allow for improved recording longevity. The probes were coated with an ultrafast degrading tyrosine-derived polycarbonate (E5005(2K)) polymer that provides temporary mechanical support for device implantation, yet degrades within 2 h post-implantation. A parametric study of probes of varying dimensions and polymer coating thicknesses were implanted in rat brains. The glial tissue response and neuronal loss were assessed from 72 h to 24 weeks post-implantation via immunohistochemistry. Main results. Experimental results suggest that both probe and polymer coating sizes affect the extent of gliosis. When an appropriate sized coating dimension (100 µm  ×  100 µm) and small probe (30 µm  ×  5 µm) was implanted, a minimal post-implantation glial response was observed. No discernible gliosis was detected when compared to tissue where a sham control consisting of a solid degradable polymer shuttle of the same dimensions was inserted. A larger polymer coating (200 µm  ×  200 µm) device induced a more severe glial response at later time points, suggesting that the initial insertion trauma can affect gliosis even when the polymer shuttle degrades rapidly. A larger degree of gliosis was also observed when comparing a larger sized probe (80 µm  ×  5 µm) to a smaller probe (30 µm  ×  5 µm) using the same polymer coating size (100 µm  ×  100 µm). There was no significant neuronal loss around the implantation sites for most device candidates except the group with largest polymer coating and probe sizes. Significance. These results suggest that: (1) the degree of mechanical trauma at device implantation and mechanical mismatches at the probe-tissue interface affect long term gliosis; (2) smaller, more flexible probes may minimize the glial response to provide improved tissue biocompatibility when used for chronic neural signal recording; and (3) some degree of glial scarring did not significantly affect neuronal distribution around the probe.

Evaluating the in vivo glial response to miniaturized parylene cortical probes coated with an ultra-fast degrading polymer to aid insertion.

PubMed

Lo, Meng-Chen; Wang, Shuwu; Singh, Sagar; Damodaran, Vinod B; Ahmed, Ijaz; Coffey, Kevin; Barker, David; Saste, Kshitij; Kals, Karanvir; Kaplan, Hilton M; Kohn, Joachim; Shreiber, David I; Zahn, Jeffrey D

2018-06-01

Despite the feasibility of short-term neural recordings using implantable microelectrodes, attaining reliable, chronic recordings remains a challenge. Most neural recording devices suffer from a long-term tissue response, including gliosis, at the device-tissue interface. It was hypothesized that smaller, more flexible intracortical probes would limit gliosis by providing a better mechanical match with surrounding tissue. This paper describes the in vivo evaluation of flexible parylene microprobes designed to improve the interface with the adjacent neural tissue to limit gliosis and thereby allow for improved recording longevity. The probes were coated with an ultrafast degrading tyrosine-derived polycarbonate (E5005(2K)) polymer that provides temporary mechanical support for device implantation, yet degrades within 2 h post-implantation. A parametric study of probes of varying dimensions and polymer coating thicknesses were implanted in rat brains. The glial tissue response and neuronal loss were assessed from 72 h to 24 weeks post-implantation via immunohistochemistry. Experimental results suggest that both probe and polymer coating sizes affect the extent of gliosis. When an appropriate sized coating dimension (100 µm  ×  100 µm) and small probe (30 µm  ×  5 µm) was implanted, a minimal post-implantation glial response was observed. No discernible gliosis was detected when compared to tissue where a sham control consisting of a solid degradable polymer shuttle of the same dimensions was inserted. A larger polymer coating (200 µm  ×  200 µm) device induced a more severe glial response at later time points, suggesting that the initial insertion trauma can affect gliosis even when the polymer shuttle degrades rapidly. A larger degree of gliosis was also observed when comparing a larger sized probe (80 µm  ×  5 µm) to a smaller probe (30 µm  ×  5 µm) using the same polymer coating size (100 µm  ×  100 µm). There was no significant neuronal loss around the implantation sites for most device candidates except the group with largest polymer coating and probe sizes. These results suggest that: (1) the degree of mechanical trauma at device implantation and mechanical mismatches at the probe-tissue interface affect long term gliosis; (2) smaller, more flexible probes may minimize the glial response to provide improved tissue biocompatibility when used for chronic neural signal recording; and (3) some degree of glial scarring did not significantly affect neuronal distribution around the probe.

[Post mortem temperature equilibration of the structures of the head. I. Thermometric techniques and principal investigations (author's transl)].

PubMed

Brinkmann, B; May, D; Riemann, U

1976-06-30

Special thin and flexible thermometric probes showing a diameter of 1 mm and a sharp end were used for post mortem (p.m.) thermometric studies in several tissues. Brain temperatures were measured by inserting a double probe through the superior orbital fissura thus allowing to record the central and the peripheral brain regions separately. Another probe was inserted into the galea and a fourth into the liver. Temperature changes were recorded simultaneously. Many variables of the human head were measured. Sixteen corpses were investigated. The results were as follows: 1. Of all temperature curves registered those of the central brain regions showed the smallest variance. 2. The p.m. temperature curve of the brain shows a sigmoid shape with a rather short "plateau" in the beginning. 3. In the early p.m. phase there is an increasing difference of temperatures between central and peripheral brain regions amounting to 2-4, 6 degrees C in the time period between 78th and 128th minute. 4. The insertion of the thin probes does not cause visible damages. Thus it should be considered for use in forensic practice. 5. Some artificial "head models" were constructed and temperature decrease recorded after warming. The curves showed the same type of sigmoid shape as those obtained from the corpses. 6. Of the possible variables measured that could influence the temperature decrease only the density of the hair seems to be of interest.

Effects of ventrolateral thalamic nucleus cooling on initiation of forelimb ballistic flexion movements by conditioned cats.

PubMed

Bénita, M; Condé, H; Dormont, J F; Schmied, A

1979-02-15

Five cats were trained to perform a forelimb ballistic flexion on a reaction time paradigm including an upper limit of about 400 ms for reinforcement (food pellets). They were implanted with a cyrogenic probe thermically insulated, except at the tip, by a vacuum jacket (outer diameter, 1.1 mm). Four cats had the probe inserted into the ventrolateral thalamic nucleus (VL), contralateral to the moving limb. During cooling they showed increased reaction times, which remained constant throughout daily sessions performed during many weeks, independent of the foreperiod but varying from 25 to 100 ms according to the subject. The temperatures used to upset the reaction times varied from +10 decrees C to -8 degrees C, depending on the localisation of the probe and on the insulation of the silver tip used to prevent nervous tissue reaction, but for each subject the reaction times always increased when the temperature was lowered. The fifth cat, with a probe inserted between VL and the Centre Median, showed a decrease of reaction times on cooling to 0 degrees C and an increase of the reaction times for a cooling at -10 degrees C. For one of the four cats with a probe properly inserted into the VL, strain-gauges were stuck on the lever to measure the latency of the decrease of the pressure exerted by the subject when the subject initiated the forelimb flexion in response to the CS. Reaction times and latencies of pressure changes were closely correlated with the movement onset, and they were equally delayed during cooling. This result demonstrates that it is not by slowing down movement velocity that reaction times are upset during VL cooling but by delaying the movement onset.

Safety and efficiency of the new micro-multiplane transoesophageal probe in paediatric cardiology.

PubMed

Hascoët, Sébastien; Peyre, Marianne; Hadeed, Khaled; Alacoque, Xavier; Chausseray, Gérald; Fesseau, Rose; Amadieu, Romain; Léobon, Bertrand; Berthomieu, Lionel; Dulac, Yves; Acar, Philippe

2014-01-01

Transoesophageal echocardiography (TOE) is feasible in neonates using a miniaturized probe, but is not widely used because of low imaging quality. To assess handling and imaging quality of a new release of a micro-TOE probe in children. Thirty-eight consecutive children, enrolled during February and May 2013, underwent TOE with the Philips S8-3t probe. Insertion, handling and image quality were assessed. The 38 children (aged 7days to 12years; weight 3.1-27kg) underwent 75 TOE (30 [40.0%] before cardiac surgery, 31 [41.3%] after cardiac surgery, 4 [5.3%] during a percutaneous procedure, 10 [13.3%] in the intensive care unit). Insertion of the micro-TOE probe was 'very easy' in 37/38 patients (97.4%). Handling was better in the lightest children (P=0.001). Image quality was mainly 'good' or 'very good', with no significant changes between preoperative and postoperative examinations or over time. Total scores (insertion, handling, image quality) were significantly better in the lightest children (P=0.02). Preoperative TOE did not provide additional information over transthoracic echocardiography. Postoperative TOE was useful to assess surgical results, but no residual lesions required extracorporeal circulation return. Micro-TOE was useful during the postoperative care of neonatal surgery with open breastbone to assess the surgical result and ventricular function. It was also useful to guide extracorporeal membrane oxygenation (ECMO) indication and withdrawal; and was a useful guide for percutaneous procedures. Micro-multiplane TOE is safe and efficient for use in neonates and children. This minimally invasive tool increases the impact of TOE in paediatric cardiology. Copyright © 2014. Published by Elsevier Masson SAS.

Visualization of the extra-articular portion of the long head of the biceps tendon during intra-articular shoulder arthroscopy.

PubMed

Festa, Anthony; Allert, Jesse; Issa, Kimona; Tasto, James P; Myer, Jonathan J

2014-11-01

To quantify the amount of the extra-articular long head of the biceps tendon (LHBT) seen during intra-articular shoulder arthroscopy by pulling the tendon into the joint with a probe through an anterior portal while viewing through a standard posterior portal. Intra-articular shoulder arthroscopy was performed on 10 forequarter cadaveric specimens. The extra-articular portion of the LHBT was evaluated by pulling the tendon into the joint with an arthroscopic probe inserted through an anterior portal. The tendon was marked at the pulley insertion on the humerus with a vascular clip before and after the tendon was pulled into the joint. An open deltopectoral approach was performed, and the amount of extra-articular tendon visualized was calculated as an absolute amount and in relation to nearby anatomic structures. An additional 1.9 cm (range, 1.4 to 2.6 cm) of extra-articular LHBT was viewed by pulling the tendon into the joint with an arthroscopic probe through an anterior portal during shoulder arthroscopy. This represented 30.8% of the extra-articular portion of the tendon, 47.7% of tendon in the bicipital groove, and 76.3% of the tendon that lies under the area from the pulley insertion to the distal edge of the transverse humeral ligament. During intra-articular shoulder arthroscopy, the extra-articular portion of the LHBT is incompletely visualized by pulling the tendon into the joint with a probe placed through an anterior portal while viewing through a standard posterior portal. An additional extra-articular portion of the LHBT may be viewed by pulling the tendon into the joint with an arthroscopic probe during shoulder arthroscopy. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Use of molecular probes to detect parasites and retrotransposons in gypsy moths

Treesearch

John H. Werren; Thomas O' Dell

1991-01-01

Retrotransposon screen: Gypsy moth families containing straggling and nonstraggling individuals were divided into categories of straggling, medium, and nonstraggling individuals, from which DNA was extracted. Four families were tested by southern hybridization and probing with ribosomal sequences designed to detect R1 and R2 retrotransposon insertions. Results showed...

Chromosome-specific staining to detect genetic rearrangements associated with chromosome 3 and/or chromosome 17

DOEpatents

Gray, Joe W.; Pinkel, Daniel; Kallioniemi, Olli-Pekka; Kallioniemi, Anne; Sakamoto, Masaru

2009-10-06

Methods and compositions for staining based upon nucleic acid sequence that employ nudeic nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyses. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acid probes are typically of a complexity greater than 50 kb, the complexity depending upon the cytogenetic application. Methods and reagents are provided for the detection of genetic rearrangements. Probes and test kits are provided for use in detecting genetic rearrangements, particularly for use in tumor cytogenetics, in the detection of disease related loci, specifically cancer, such as chronic myelogenous leukemia (CML), retinoblastoma, ovarian and uterine cancers, and for biological dosimetry. Methods and reagents are described for cytogenetic research, for the differentiation of cytogenetically similar but genetically different diseases, and for many prognostic and diagnostic applications.

EFFECT OF PILOT HOLE TAPPING ON PULLOUT STRENGTH AND INSERTION TORQUE OF DUAL CORE PEDICLE SCREWS.

PubMed

Rosa, Rodrigo César; Silva, Patrícia; Falcai, Maurício José; Shimano, Antônio Carlos; Defino, Helton Luiz Aparecido

2010-01-01

To evaluate the influence of pilot hole tapping on pullout resistance and insertion torque of pedicle screws with a conical core. Mechanical tests using a universal testing machine were performed on pedicle screws with a conical core that were inserted into pedicles in the fifth lumbar vertebra of calves. The insertion torque was measured using a torque meter with a capacity of 10 Nm, which was considered to be the highest torque value. The pilot holes were prepared using a probe of external diameter 3.8 mm and tapping of the same dimensions and thread characteristics as the screw. Decreased insertion torque and pullout resistance were observed in the group with prior tapping of the pilot hole. Pilot hole tapping reduced the insertion torque and pullout resistance of pedicle screws with a conical core that had been inserted into the pedicle of the fifth lumbar vertebra of calves.

Physical mapping of complex genomes

DOEpatents

Evans, G.A.

1993-06-15

A method for the simultaneous identification of overlapping cosmid clones among multiple cosmid clones and the use of the method for mapping complex genomes are provided. A library of cosmid clones that contains the DNA to be mapped is constructed and arranged in a manner such that individual clones can be identified and replicas of the arranged clones prepared. In preferred embodiments, the clones are arranged in a two dimensional matrix. In such embodiments, the cosmid clones in a row are pooled, mixed probes complementary to the ends of the DNA inserts in the pooled clones are synthesized, hybridized to a first replica of the library. Hybridizing clones, which include the pooled row, are identified. A second portion of clones is prepared by pooling cosmid clones that correspond to a column in the matrix. The second pool thereby includes one clone from the first portion pooled clones. This common clone is located on the replica at the intersection of the column and row. Mixed probes complementary to the ends of the DNA inserts in the second pooled portion of clones are prepared and hybridized to a second replica of the library. The hybridization pattern on the first and second replicas of the library are compared and cross-hybridizing clones, other than the clones in the pooled column and row, that hybridize to identical clones in the first and second replicas are identified. These clones necessarily include DNA inserts that overlap with the DNA insert in the common clone located at the intersection of the pooled row and pooled column. The DNA in the entire library may be mapped by pooling the clones in each of the rows and columns of the matrix, preparing mixed end-specific probes and hybridizing the probes from each row or column to a replica of the library. Since all clones in the library are located at the intersection of a column and a row, the overlapping clones for all clones in the library may be identified and a physical map constructed.

Intracranial surgical operative apparatus

NASA Technical Reports Server (NTRS)

Sheldon, Charles H. (Inventor); Frazer, Robert E. (Inventor); Lutes, Harold R. (Inventor)

1983-01-01

Apparatus for operating on the brain with minimal disturbances thereto, including a bullet-shaped expandable device with an end that can be closed for insertion through a small hole in the brain. The device can be expanded after insertion to leave an air pocket through which to extend viewing and cutting devices which enable operation on tumors or the like that lie at the end of the expanded device. A set of probes of varying diameters are also provided, to progressively enlarge a passage leading to the tumor, prior to inserting the expandable device.

Cold cathode vacuum discharge tube

DOEpatents

Boettcher, Gordon E.

1998-01-01

A cold cathode vacuum discharge tube, and method for making same, with an interior surface of the trigger probe coated with carbon deposited by carbon vapor deposition (CVD) or diamond-like carbon (DLC) deposition. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging.

Insect-machine interface based neurocybernetics.

PubMed

Bozkurt, Alper; Gilmour, Robert F; Sinha, Ayesa; Stern, David; Lal, Amit

2009-06-01

We present details of a novel bioelectric interface formed by placing microfabricated probes into insect during metamorphic growth cycles. The inserted microprobes emerge with the insect where the development of tissue around the electronics during the pupal development allows mechanically stable and electrically reliable structures coupled to the insect. Remarkably, the insects do not react adversely or otherwise to the inserted electronics in the pupae stage, as is true when the electrodes are inserted in adult stages. We report on the electrical and mechanical characteristics of this novel bioelectronic interface, which we believe would be adopted by many investigators trying to investigate biological behavior in insects with negligible or minimal traumatic effect encountered when probes are inserted in adult stages. This novel insect-machine interface also allows for hybrid insect-machine platforms for further studies. As an application, we demonstrate our first results toward navigation of flight in moths. When instrumented with equipment to gather information for environmental sensing, such insects potentially can assist man to monitor the ecosystems that we share with them for sustainability. The simplicity of the optimized surgical procedure we invented allows for batch insertions to the insect for automatic and mass production of such hybrid insect-machine platforms. Therefore, our bioelectronic interface and hybrid insect-machine platform enables multidisciplinary scientific and engineering studies not only to investigate the details of insect behavioral physiology but also to control it.

Effect of nonparallel placement of in-circle bipolar radiofrequency ablation probes on volume of tissue ablated with heat sink.

PubMed

Pillai, Krishna; Al-Alem, Ihssan; Akhter, Javed; Chua, Terence C; Shehata, Mena; Morris, David L

2015-06-01

Percutaneous bipolar radiofrequency ablation (RFA) is a minimally invasive technique for treating liver tumors. It is not always possible to insert the bipolar probes parallel to each other on either side of tumor, since it restricts maneuverability away from vital structures or ablate certain tumor shape. Therefore, we investigated how nonparallel placement of probes affected ablation. Bipolar RFA in parallel and in divergent positions were submerged in tissue model (800 mL egg white) at 37°C and ablated. Temperature probes, T1 and T2 were placed 8.00 mm below the tip of the probes, T3 in between the probe coil elements and T4 and T5 at water inlet and outlet, respectively. Both models with heat sink (+HS) and without (-HS) were investigated. The mean ablated tissue volume, mass, density and height increased linearly with unit angle increase for -HS model. With +HS, a smaller increase in mean volume and mass, a slightly greater increase in mean density but a reduction in height of tissue was seen. The mean ablation time and duration of maximum temperature with +HS was slightly larger, compared with -HS, while -HS ablated at a slightly higher temperature. The heat sink present was minimal for probes in parallel position compared to nonparallel positions. Divergence from parallel insertion of bipolar RFA probes increased the mean volume, mass, and density of tissue ablated. However, the presence of large heat sinks may limit the application of this technique, when tumors border on larger vessels. © The Author(s) 2014.

Immediate implant placement into fresh extraction sockets versus delayed implants into healed sockets: A systematic review and meta-analysis.

PubMed

Mello, C C; Lemos, C A A; Verri, F R; Dos Santos, D M; Goiato, M C; Pellizzer, E P

2017-09-01

The aim of this systematic review and meta-analysis was to compare the survival rate of the implants and the peri-implant tissue changes associated with implants inserted in fresh extraction sockets and those inserted in healed sockets. This review has been registered at PROSPERO under the number CRD42016043309. A systematic search was conducted by two reviewers independently in the databases PubMed/MEDLINE, Embase, and the Cochrane Library using different search terms; articles published until November 2016 were searched for. The searches identified 30 eligible studies. A total of 3,049 implants were installed in a total of 1,435 patients with a mean age of 46.68 years and a minimum of 6 months of follow-up. The survival rate of delayed implants (98.38%) was significantly greater than immediate implants (95.21%) (p=.001). For the marginal bone loss (p=.32), implant stability quotients values (p=.44), and pocket probing depth (p=.94) there was no significant difference between the analysed groups. The immediate implants placed in fresh sockets should be performed with caution because of the significantly lower survival rates than delayed implants inserted in healed sockets. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The vector homology problem in diagnostic nucleic acid hybridization of clinical specimens.

PubMed Central

Ambinder, R F; Charache, P; Staal, S; Wright, P; Forman, M; Hayward, S D; Hayward, G S

1986-01-01

Nucleic acid hybridization techniques using cloned probes are finding application in assays of clinical specimens in research and diagnostic laboratories. The probes that we and others have used are recombinant plasmids composed of viral inserts and bacterial plasmid vectors such as pBR322. We suspected that there was material homologous to pBR322 present in many clinical samples. because hybridization occurred in samples which lacked evidence of virus by other techniques. If the presence of this vector-homologous material was unrecognized, hybridization in the test sample might erroneously be interpreted as indicating the presence of viral sequences. In this paper we demonstrate specific hybridization of labeled pBR322 DNA with DNA from various clinical samples. Evidence is presented that nonspecific probe trapping could not account for this phenomenon. In mixing experiments, it is shown that contamination of clinical samples with bacteria would explain such a result. Approaches tested to circumvent this problem included the use of isolated insert probes, alternate cloning vectors, and cold competitor pBR322 DNA in prehybridization and hybridization mixes. None proved entirely satisfactory. We therefore emphasize that it is essential that all hybridization detection systems use a control probe of the vector alone in order to demonstrate the absence of material with vector homology in the specimen tested. Images PMID:3013928

In vivo photoacoustic imaging of prostate brachytherapy seeds

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin; Boctor, Emad M.

2014-03-01

We conducted an approved canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. Brachytherapy seeds coated with black ink were inserted into the canine prostate using methods similar to a human procedure. A transperineal, interstitial, fiber optic light delivery method, coupled to a 1064 nm laser, was utilized to irradiate the prostate and the resulting acoustic waves were detected with a transrectal ultrasound probe. The fiber was inserted into a high dose rate (HDR) brachytherapy needle that acted as a light-diffusing sheath, enabling radial light delivery from the tip of the fiber inside the sheath. The axis of the fiber was located at a distance of 4-9 mm from the long axis of the cylindrical seeds. Ultrasound images acquired with the transrectal probe and post-operative CT images of the implanted seeds were analyzed to confirm seed locations. In vivo limitations with insufficient light delivery within the ANSI laser safety limit (100 mJ/cm2) were overcome by utilizing a short-lag spatial coherence (SLSC) beamformer, which provided average seed contrasts of 20-30 dB for energy densities ranging 8-84 mJ/cm2. The average contrast was improved by up to 20 dB with SLSC beamforming compared to conventional delay-and-sum beamforming. There was excellent agreement between photoacoustic, ultrasound, and CT images. Challenges included visualization of photoacoustic artifacts that corresponded with locations of the optical fiber and hyperechoic tissue structures.

Cold cathode vacuum discharge tube

DOEpatents

Boettcher, G.E.

1998-03-10

A cold cathode vacuum discharge tube, and method for making same, are disclosed with an interior surface of the trigger probe coated with carbon deposited by carbon vapor deposition (CVD) or diamond-like carbon (DLC) deposition. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging. 15 figs.

Cold cathode vacuum discharge tube

DOEpatents

Boettcher, G.E.

1998-04-14

A cold cathode vacuum discharge tube, and method for making same, with an interior surface of the trigger probe coated with carbon deposited by chemical vapor deposition (CVD) or diamond-like carbon (DLC) deposition are disclosed. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging. 14 figs.

Micro-optical fiber probe for use in an intravascular Raman endoscope.

PubMed

Komachi, Yuichi; Sato, Hidetoshi; Aizawa, Katsuo; Tashiro, Hideo

2005-08-01

We believe that we have developed the narrowest optical-fiber Raman probe ever reported, 600 microm in total diameter, that can be inserted into coronary arteries. The selection of suitable optical fibers, filters, and a processing method is discussed. Custom-made filters attached to the front end of a probe eliminate the background Raman signals of the optical fiber itself. The experimental evaluation of various optical fibers is carried out for the selection of suitable fibers. Measurement of the Raman spectra of an atherosclerotic lesion of a rabbit artery in vitro demonstrates the excellent performance of the micro-Raman probe.

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy.

PubMed

Yang, Joon-Mo; Chen, Ruimin; Favazza, Christopher; Yao, Junjie; Li, Chiye; Hu, Zhilin; Zhou, Qifa; Shung, K Kirk; Wang, Lihong V

2012-10-08

We have created a 2.5-mm outer diameter integrated photo-acoustic and ultrasonic mini-probe which can be inserted into a standard video endoscope's instrument channel. A small-diameter focused ultrasonic transducer made of PMN-PT provides adequate signal sensitivity, and enables miniaturization of the probe. Additionally, this new endoscopic probe utilizes the same scanning mirror and micromotor-based built-in actuator described in our previous reports; however, the length of the rigid distal section of the new probe has been further reduced to ~35 mm. This paper describes the technical details of the mini-probe and presents experimental results that both quantify the imaging performance and demonstrate its in vivo imaging capability, which suggests that it could work as a mini-probe for certain clinical applications.

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy

PubMed Central

Yang, Joon-Mo; Chen, Ruimin; Favazza, Christopher; Yao, Junjie; Li, Chiye; Hu, Zhilin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2012-01-01

We have created a 2.5-mm outer diameter integrated photo-acoustic and ultrasonic mini-probe which can be inserted into a standard video endoscope’s instrument channel. A small-diameter focused ultrasonic transducer made of PMN-PT provides adequate signal sensitivity, and enables miniaturization of the probe. Additionally, this new endoscopic probe utilizes the same scanning mirror and micromotor-based built-in actuator described in our previous reports; however, the length of the rigid distal section of the new probe has been further reduced to ~35 mm. This paper describes the technical details of the mini-probe and presents experimental results that both quantify the imaging performance and demonstrate its in vivo imaging capability, which suggests that it could work as a mini-probe for certain clinical applications. PMID:23188360

Cobra Probes Containing Replaceable Thermocouples

NASA Technical Reports Server (NTRS)

Jones, John; Redding, Adam

2007-01-01

A modification of the basic design of cobra probes provides for relatively easy replacement of broken thermocouples. Cobra probes are standard tube-type pressure probes that may also contain thermocouples and that are routinely used in wind tunnels and aeronautical hardware. They are so named because in side views, they resemble a cobra poised to attack. Heretofore, there has been no easy way to replace a broken thermocouple in a cobra probe: instead, it has been necessary to break the probe apart and then rebuild it, typically at a cost between $2,000 and $4,000 (2004 prices). The modified design makes it possible to replace the thermocouple, in minimal time and at relatively low cost, by inserting new thermocouple wire in a tube.

USSR Report, Electronics and Electrical Engineering, No. 102

DTIC Science & Technology

1983-04-29

S. IAbstract] The laser probing method is applied to measurement of absorption , transmission, and reflection coefficients, also insertion losses...electronic clock. The method of measurements is based on absorption of monochromatic radiation from the lasers, the latter being tuned to the fine...Acoustic-Wave Transducer by Laser Probing Method (A. B. Voroshnin, G. S. Felinskiy; IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY: RADIOELEKTRONIKA, Dec 82

Z-DNA binding protein from chicken blood nuclei

NASA Technical Reports Server (NTRS)

Herbert, A. G.; Spitzner, J. R.; Lowenhaupt, K.; Rich, A.

1993-01-01

A protein (Z alpha) that appears to be highly specific for the left-handed Z-DNA conformer has been identified in chicken blood nuclear extracts. Z alpha activity is measured in a band-shift assay by using a radioactive probe consisting of a (dC-dG)35 oligomer that has 50% of the deoxycytosines replaced with 5-bromodeoxycytosine. In the presence of 10 mM Mg2+, the probe converts to the Z-DNA conformation and is bound by Z alpha. The binding of Z alpha to the radioactive probe is specifically blocked by competition with linear poly(dC-dG) stabilized in the Z-DNA form by chemical bromination but not by B-form poly(dC-dG) or boiled salmon-sperm DNA. In addition, the binding activity of Z alpha is competitively blocked by supercoiled plasmids containing a Z-DNA insert but not by either the linearized plasmid or by an equivalent amount of the parental supercoiled plasmid without the Z-DNA-forming insert. Z alpha can be crosslinked to the 32P-labeled brominated probe with UV light, allowing us to estimate that the minimal molecular mass of Z alpha is 39 kDa.

Molecular cytogenetic analysis of feline leukemia virus insertions in cat lymphoid tumor cells.

PubMed

Fujino, Yasuhito; Satoh, Hitoshi; Ohno, Koichi; Tsujimoto, Hajime

2010-02-01

This study was conducted to map the acquired proviral insertions in the chromosomal genome of feline lymphoid tumors induced by feline leukemia virus (FeLV). Chromosome specimens of the lymphoid tumor-derived cell lines and normal cat lymphocytes were subjected to fluorescence in situ hybridization and tyramide signal amplification, using an exogenous FeLV-A genome as a probe. Specific hybridization signals were detected only on the metaphase chromosomes of the tumor cells. Poisson's distribution-based statistics indicated that 6 chromosomal loci in each cell line showed FeLV integration. In the examination of metaphase chromosomes of FL-74, FT-1 and KO-1 cells, significant signals were detected on B2p15-p14, B2q11, D1p14, E1p14-p13, E1q12 and F2q16; A2p23-p22, B2p15-p14, B4p15-p14, D4q23-q24, E1p14-p13 and E2p13-p12; and A2p22, A3q22, B1p13, B1q13, D1p13 and D3p15-p14, respectively. Consistently, Southern blot hybridization using an FeLV LTR-U3 probe specific for exogenous FeLV revealed the presence of at least 6 copies of exogenous FeLV proviruses at different integration sites in each cell line. These results indicate that there may be common FeLV integration sites at least in A2p22 and B2p15-p14. The cytogenetic analysis used in this study can promptly screen FeLV insertions and provide tags for identifying the novel common integration site. 2009 Elsevier B.V. All rights reserved.

Nanoscale laminin coating modulates cortical scarring response around implanted silicon microelectrode arrays

NASA Astrophysics Data System (ADS)

He, Wei; McConnell, George C.; Bellamkonda, Ravi V.

2006-12-01

Neural electrodes could significantly enhance the quality of life for patients with sensory and/or motor deficits as well as improve our understanding of brain functions. However, long-term electrical connectivity between neural tissue and recording sites is compromised by the development of astroglial scar around the recording probes. In this study we investigate the effect of a nanoscale laminin (LN) coating on Si-based neural probes on chronic cortical tissue reaction in a rat model. Tissue reaction was evaluated after 1 day, 1 week, and 4 weeks post-implant for coated and uncoated probes using immunohistochemical techniques to evaluate activated microglia/macrophages (ED-1), astrocytes (GFAP) and neurons (NeuN). The coating did not have an observable effect on neuronal density or proximity to the electrode surface. However, the response of microglia/macrophages and astrocytes was altered by the coating. One day post-implant, we observed an ~60% increase in ED-1 expression near LN-coated probe sites compared with control uncoated probe sites. Four weeks post-implant, we observed an ~20% reduction in ED-1 expression along with an ~50% reduction in GFAP expression at coated relative to uncoated probe sites. These results suggest that LN has a stimulatory effect on early microglia activation, accelerating the phagocytic function of these cells. This hypothesis is further supported by the increased mRNA expression of several pro-inflammatory cytokines (TNF-α, IL-1 and IL-6) in cultured microglia on LN-bound Si substrates. LN immunostaining of coated probes immediately after insertion and retrieval demonstrates that the coating integrity is not compromised by the shear force during insertion. We speculate, based on these encouraging results, that LN coating of Si neural probes could potentially improve chronic neural recordings through dispersion of the astroglial scar.

Conjugated Polymer Actuators for Articulating Neural Probes and Electrode Interfaces

NASA Astrophysics Data System (ADS)

Daneshvar, Eugene Dariush

This thesis investigated the potential use of polypyrrole (PPy) doped with dodecylbenzenesulfonate (DBS) to controllably articulate (bend or guide) flexible neural probes and electrodes. PPy(DBS) actuation performance was characterized in the ionic mixture and temperature found in the brain. Nearly all the ions in aCSF were exchanged into the PPy---the cations Na +, K+, Mg2+, Ca2+, as well as the anion PO43-; Cl- was not present. Nevertheless, deflections in aCSF were comparable to those in NaDBS and they were monotonic with oxidation level: strain increased upon reduction, with no reversal of motion despite the mixture of ionic charges and valences being exchanged. Actuation depended on temperature. Upon warming, the cyclic voltammograms showed additional peaks and an increase of 70% in the consumed charge. Actuation strain was monotonic under these conditions, demonstrating that conducting polymer actuators can indeed be used for neural interface and neural probe applications. In addition, a novel microelectro-mechanical system (MEMS) was developed to measure previously disregarded residual stress in a bilayer actuator. Residual stresses are a major concern for MEMS devices as that they can dramatically influence their yield and functionality. This device introduced a new technique to measure micro-scaled actuation forces that may be useful for characterization of other MEMS actuators. Finally, a functional movable parylene-based neural electrode prototype was developed. Employing PPy(DBS) actuators, electrode projections were successfully controlled to either remain flat or actuate out-of-plane and into a brain phantom during insertion. An electrode projection 800 microm long and 50 microm wide was able to deflect almost 800 microm away from the probe substrate. Applications that do not require insertion into tissue may also benefit from the electrode projections described here. Implantable neural interface devices are a critical component to a broad class of emerging neuroprosthetic and neurostimulation systems aimed to restore functionality, or abate symptoms related to physical impairments, loss of sensory abilities, and neurological disorders. The therapeutic outcome and performance of these systems hinge to a large degree on the proximity, size, and placement of the device or interface with respect to the targeted neurons or tissue.

Immediate Versus Delayed Loading of Implant for Replacement of Missing Mandibular First Molar: A Randomized Prospective Six Years Clinical Study.

PubMed

Chidagam, Prudhvi Raj Lakshmi Venkata; Gande, Vijaya Chandra; Yadlapalli, Sravanthi; Venkata, Ramani Yarlagadda; Kondaka, Sudheer; Chedalawada, Sravya

2017-04-01

Emergence of dental implants made the replacement of missing tooth easy. During the early days of introduction, implants were loaded three to six months after implant insertion, but understanding of healing cascade and improved production technology has changed the phase of restoration from delayed to immediate loading. To evaluate and compare the clinical outcome of immediate and delayed loaded implant supported prosthesis for missing mandibular first molar. The objectives were bleeding on probing, probing depth, implant mobility, marginal bone level and peri-implant radiolucency were evaluated during follow up period. Twenty patients were included in this study who were in the need of fixed implant supported prosthesis for missing mandibular first molar. Single tooth implant with immediate loading done within two days of implant insertion in one group and another group were loaded after three months of implant insertion. These groups were evaluated clinically and radiographically over a period of 72 months after loading using Wilcoxon matched pairs test and Mann-Whitney U test. The study consists of 14 male and six female patients with the age range of 19 to 31 years. There was no bleeding on probing and probing depth remained well within the normal range even after 72 months of loading among both the groups. Minimal marginal bone loss observed with no mobility and peri-implant radiolucency. Implant supported prosthesis for missing mandibular first molar with immediate loading can be used as a successful treatment modality. It reduces treatment time, provides early function and prevents undue migration of adjacent tooth. Immediate loading showed similar clinical and radiographic results as that of delayed loading, indicating it as an equally efficient technique for implant supported prosthesis.

Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak

NASA Astrophysics Data System (ADS)

Brunner, D.; Kuang, A. Q.; LaBombard, B.; Burke, W.

2017-07-01

A new servomotor drive system has been developed for the horizontal reciprocating probe on the Alcator C-Mod tokamak. Real-time measurements of plasma temperature and density—through use of a mirror Langmuir probe bias system—combined with a commercial linear servomotor and controller enable self-adaptive position control. Probe surface temperature and its rate of change are computed in real time and used to control probe insertion depth. It is found that a universal trigger threshold can be defined in terms of these two parameters; if the probe is triggered to retract when crossing the trigger threshold, it will reach the same ultimate surface temperature, independent of velocity, acceleration, or scrape-off layer heat flux scale length. In addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system.

Development and investigation of flexible polymer neural probe for chronic neural recording

NASA Astrophysics Data System (ADS)

Smith, Courtney; Song, Kyo D.; Yoon, Hargsoon; Kim, Woong-Ki; Zeng, Tao; Sanford, Larry D.

2012-04-01

Neural recording through microelectrodes requires biocompatibility and long term chronic usage. With a potential for various applications and effort to improve the performance of neural recording probes, consideration is taken to the tissue and cellular effects in these device designs. The degeneration of neurons due to brain tissue motion is an issue along with brain tissue inflammation in the insertion of the probes. To account for motion and irritation the material structure of the probes must be improved upon. This research presents the fabrication of neural probes on the microscale utilizing flexible polymers. Polyimide neural probes have been considered possibly to reduce degradation in their variability caused by brain motion. The microfabrication of the polyimide neural probe has an increased flexibility while accounting for biocompatibility and the needs for chronic use. Through microfabrication processes a needle probe is produced and tested for neural recording.

Interpretation of plasma impurity deposition probes. Analytic approximation

NASA Astrophysics Data System (ADS)

Stangeby, P. C.

1987-10-01

Insertion of a probe into the plasma induces a high speed flow of the hydrogenic plasma to the probe which, by friction, accelerates the impurity ions to velocities approaching the hydrogenic ion acoustic speed, i.e., higher than the impurity ion thermal speed. A simple analytic theory based on this effect provides a relation between impurity fluxes to the probe Γimp and the undisturbed impurity ion density nimp, with the hydrogenic temperature and density as input parameters. Probe size also influences the collection process and large probes are found to attract a higher flux density than small probes in the same plasma. The quantity actually measured, cimp, the impurity atom surface density (m-2) net-deposited on the probe, is related to Γimp and thus to nimp by taking into account the partial removal of deposited material caused by sputtering and the redeposition process.

Method for improving the durability of ion insertion materials

DOEpatents

Lee, Se-Hee; Tracy, C. Edwin; Cheong, Hyeonsik M.

2002-01-01

The invention provides a method of protecting an ion insertion material from the degradative effects of a liquid or gel-type electrolyte material by disposing a protective, solid ion conducting, electrically insulating, layer between the ion insertion layer and the liquid or gel-type electrolyte material. The invention further provides liquid or gel-type electrochemical cells having improved durability having a pair of electrodes, a pair of ion insertion layers sandwiched between the pair of electrodes, a pair of solid ion conducting layers sandwiched between the ion insertion layers, and a liquid or gel-type electrolyte material disposed between the solid ion conducting layers, where the solid ion conducting layer minimizes or prevents degradation of the faces of the ion insertion materials facing the liquid or gel-type electrolyte material. Electrochemical cells of this invention having increased durability include secondary lithium batteries and electrochromic devices.

Body Temperature Measurements for Metabolic Phenotyping in Mice.

PubMed

Meyer, Carola W; Ootsuka, Youichirou; Romanovsky, Andrej A

2017-01-01

Key Points Rectal probing is subject to procedural bias. This method is suitable for first-line phenotyping, provided probe depth and measurement duration are standardized. It is also useful for detecting individuals with out-of-range body temperatures (during hypothermia, torpor).The colonic temperature attained by inserting the probe >2 cm deep is a measure of deep (core) body temperature.IR imaging of the skin is useful for detecting heat leaks and autonomous thermoregulatory alterations, but it does not measure body temperature.Temperature of the hairy or shaved skin covering the inter-scapular brown adipose tissue can be used as a measure of BAT thermogenesis. However, obtaining such measurements of sufficient quality is very difficult, and interpreting them can be tricky. Temperature differences between the inter-scapular and lumbar areas can be a better measure of the thermogenic activity of inter-scapular brown adipose tissue.Implanted probes for precise determination of BAT temperature (changes) should be fixed close to the Sulzer's vein. For measurement of BAT thermogenesis, core body temperature and BAT temperature should be recorded simultaneously.Tail temperature is suitable to compare the presence or absence of vasoconstriction or vasodilation.Continuous, longitudinal monitoring of core body temperature is preferred over single probing, as the readings are taken in a non-invasive, physiological context.Combining core body temperature measurements with metabolic rate measurements yields insights into the interplay between heat production and heat loss (thermal conductance), potentially revealing novel thermoregulatory phenotypes. Endothermic organisms rely on tightly balanced energy budgets to maintain a regulated body temperature and body mass. Metabolic phenotyping of mice, therefore, often includes the recording of body temperature. Thermometry in mice is conducted at various sites, using various devices and measurement practices, ranging from single-time probing to continuous temperature imaging. Whilst there is broad agreement that body temperature data is of value, procedural considerations of body temperature measurements in the context of metabolic phenotyping are missing. Here, we provide an overview of the various methods currently available for gathering body temperature data from mice. We explore the scope and limitations of thermometry in mice, with the hope of assisting researchers in the selection of appropriate approaches, and conditions, for comprehensive mouse phenotypic analyses.

Intrasulcal Electrocorticography in Macaque Monkeys with Minimally Invasive Neurosurgical Protocols

PubMed Central

Matsuo, Takeshi; Kawasaki, Keisuke; Osada, Takahiro; Sawahata, Hirohito; Suzuki, Takafumi; Shibata, Masahiro; Miyakawa, Naohisa; Nakahara, Kiyoshi; Iijima, Atsuhiko; Sato, Noboru; Kawai, Kensuke; Saito, Nobuhito; Hasegawa, Isao

2011-01-01

Electrocorticography (ECoG), multichannel brain-surface recording and stimulation with probe electrode arrays, has become a potent methodology not only for clinical neurosurgery but also for basic neuroscience using animal models. The highly evolved primate's brain has deep cerebral sulci, and both gyral and intrasulcal cortical regions have been implicated in important functional processes. However, direct experimental access is typically limited to gyral regions, since placing probes into sulci is difficult without damaging the surrounding tissues. Here we describe a novel methodology for intrasulcal ECoG in macaque monkeys. We designed and fabricated ultra-thin flexible probes for macaques with micro-electro-mechanical systems technology. We developed minimally invasive operative protocols to implant the probes by introducing cutting-edge devices for human neurosurgery. To evaluate the feasibility of intrasulcal ECoG, we conducted electrophysiological recording and stimulation experiments. First, we inserted parts of the Parylene-C-based probe into the superior temporal sulcus to compare visually evoked ECoG responses from the ventral bank of the sulcus with those from the surface of the inferior temporal cortex. Analyses of power spectral density and signal-to-noise ratio revealed that the quality of the ECoG signal was comparable inside and outside of the sulcus. Histological examination revealed no obvious physical damage in the implanted areas. Second, we placed a modified silicone ECoG probe into the central sulcus and also on the surface of the precentral gyrus for stimulation. Thresholds for muscle twitching were significantly lower during intrasulcal stimulation compared to gyral stimulation. These results demonstrate the feasibility of intrasulcal ECoG in macaques. The novel methodology proposed here opens up a new frontier in neuroscience research, enabling the direct measurement and manipulation of electrical activity in the whole brain. PMID:21647392

Pioneer probe mission with orbiter option

NASA Technical Reports Server (NTRS)

1975-01-01

A spacecraft is described which is based on Pioneer 10 and 11, and existing propulsion technology; it can transport and release a probe for entry into Jupiter's atmosphere, and subsequently maneuver to place the spacecraft in orbit about Jupiter. Orbital operations last 3 years and include maneuvers to provide multiple close satellite encounters which allow the orbit to be significantly changed to explore different parts of the magnetosphere. A mission summary, a guide to related documents, and background information about Jupiter are presented along with mission analysis over the complete mission profile. Other topics discussed include the launch, interplanetary flight, probe release and orbit deflection, probe entry, orbit selection, orbit insertion, periapsis raising, spacecraft description, and the effects of Jupiter's radiation belt on both orbiter and the probe.

Concealed Accessory Pathways with a Single Ventricular and Two Discrete Atrial Insertion Sites.

PubMed

Kipp, Ryan T; Abu Sham'a, Raed; Hiroyuki, Ito; Han, Frederick T; Refaat, Marwan; Hsu, Jonathan C; Field, Michael E; Kopp, Douglas E; Marcus, Gregory M; Scheinman, Melvin M; Hoffmayer, Kurt S

2017-03-01

Atrioventricular reciprocating tachycardia (AVRT) utilizing a concealed accessory pathway is common. It is well appreciated that some patients may have multiple accessory pathways with separate atrial and ventricular insertion sites. We present three cases of AVRT utilizing concealed pathways with evidence that each utilizing a single ventricular insertion and two discrete atrial insertion sites. In case one, two discrete atrial insertion sites were mapped in two separate procedures, and only during the second ablation was the Kent potential identified. Ablation of the Kent potential at this site remote from the two atrial insertion sites resulted in the termination of the retrograde conduction in both pathways. Case two presented with supraventricular tachycardia (SVT) with alternating eccentric atrial activation patterns without alteration in the tachycardia cycle length. The two distinct atrial insertion sites during orthodromic AVRT and ventricular pacing were targeted and each of the two atrial insertion sites were successfully mapped and ablated. In case three, retrograde decremental conduction utilizing both atrial insertion sites was identified prior to ablation. After mapping and ablation of the first discrete atrial insertion site, tachycardia persisted utilizing the second atrial insertion site. Only after ablation of the second atrial insertion site was SVT noninducible, and VA conduction was no longer present. Concealed retrograde accessory pathways with discrete atrial insertion sites may have a common ventricular insertion site. Identification and ablation of the ventricular insertion site or the separate discrete atrial insertion sites result in successful treatment. © 2017 Wiley Periodicals, Inc.

Local opiate receptors in the sinoatrial node moderate vagal bradycardia.

PubMed

Farias, M; Jackson, K; Stanfill, A; Caffrey, J L

2001-02-20

Met-enkephalin-arg-phe (MEAP) interrupts vagal bradycardia when infused into the systemic circulation. This study was designed to locate the opiate receptors functionally responsible for this inhibition. Previous observations suggested that the receptors were most likely located in either intracardiac parasympathetic ganglia or the pre-junctional nerve terminals innervating the sinoatrial node. In this study 10 dogs were instrumented with a microdialysis probe inserted into the sinoatrial node. The functional position of the probe was tested by briefly introducing norepinephrine into the probe producing an increase in heart rate of more than 30 beats/min. Vagal stimulations were conducted at 0.5, 1.2 and 4 Hz during vehicle infusion (saline ascorbate). Cardiovascular responses during vagal stimulation were recorded on-line. MEAP was infused directly into the sinoatrial node via the microdialysis probe. The evaluation of vagal bradycardia was repeated during the nodal application of MEAP, diprenorphine (opiate antagonist), and diprenorphine co-infused with MEAP. MEAP introduced into the sinoatrial node via the microdialysis probe reduced vagal bradycardia by more than half. Simultaneous local nodal blockade of these receptors with the opiate antagonist, diprenorphine, eliminated the effect of MEAP demonstrating the participation by opiate receptors. Systemic infusions of MEAP produced a reduction in vagal bradycardia nearly identical to that observed during nodal administration. When local nodal opiate receptors were blocked with diprenorphine, the systemic effect of MEAP was eliminated. These data lead us to suggest that the opiate receptors responsible for the inhibition of vagal bradycardia are located within the sinoatrial node with few, if any, participating extra-nodal or ganglionic receptors.

Transvaginal ultrasound (image)

MedlinePlus

Transvaginal ultrasound is a method of imaging the genital tract in females. A hand held probe is inserted directly ... vaginal cavity to scan the pelvic structures, while ultrasound pictures are viewed on a monitor. The test ...

Advantages of Direct Insertion of a Straight Probe Without a Guide Tube During Anterior Odontoid Screw Fixation of Odontoid Fractures.

PubMed

Park, Jin Hoon; Kang, Dong-Ho; Lee, Moon Kyu; Yoo, Byoungwoo; Jung, Sang Ku; Hwang, Soo-Hyun; Kim, Jeoung Hee; Oh, Sunkyu; Lee, Eun Jung; Jeon, Sang Ryong; Roh, Sung Woo; Rhim, Seung Chul

2016-05-01

A retrospective cohort study. The aim of this study was to compare the anterior odontoid screw fixation (AOSF) with a guide tube or with a straight probe. AOSF associates with several complications, including malpositioning, fixation loss, and screw breakage. Screw pull-out from the C2 body is the most common complication. All consecutive patients with type II or rostral shallow type III odontoid fractures who underwent AOSFs during the study period were enrolled retrospectively. The guide-tube AOSF method followed the standard published method except C3 body and C2-3 disc annulus rimming was omitted to prevent disc injury; instead, the guide tube was anchored at the anterior inferior C2 vertebra corner. After 2 screw pull-outs, the guide-tube cohort was analyzed to identify the cause of instrument failure. Thereafter, the straight-probe method was developed. A guide tube was not used. A small pilot hole was made on the most anterior side of the inferior endplate, followed by insertion of a 2.5 mm straight probe through the C2 body. Non-union and instrument failure rates and screw-direction angles of the guide-tube and straight-probe groups were recorded. The guide-tube group (n = 13) had 2 screw pull-outs and 1 non-union. The straight-probe group (n = 8) had no complications and significantly larger screw-direction angles than the guide-tube group (60.5 ± 4.63 vs. 54.8 ± 3.82 degrees; P = 0.047). Straight-probe AOSF yielded larger direction angles without injuring bone and disc. Complications were absent. The procedure was easier than guide-tube AOSF and assured sufficient engagement, even in horizontal fracture orientation cases. 3.

An inverse method to estimate stem surface heat flux in wildland fires

Treesearch

Anthony S. Bova; Matthew B. Dickinson

2009-01-01

Models of wildland fire-induced stem heating and tissue necrosis require accurate estimates of inward heat flux at the bark surface. Thermocouple probes or heat flux sensors placed at a stem surface do not mimic the thermal response of tree bark to flames.We show that data from thin thermocouple probes inserted just below the bark can be used, by means of a one-...

Accurate multi-robot targeting for keyhole neurosurgery based on external sensor monitoring.

PubMed

Comparetti, Mirko Daniele; Vaccarella, Alberto; Dyagilev, Ilya; Shoham, Moshe; Ferrigno, Giancarlo; De Momi, Elena

2012-05-01

Robotics has recently been introduced in surgery to improve intervention accuracy, to reduce invasiveness and to allow new surgical procedures. In this framework, the ROBOCAST system is an optically surveyed multi-robot chain aimed at enhancing the accuracy of surgical probe insertion during keyhole neurosurgery procedures. The system encompasses three robots, connected as a multiple kinematic chain (serial and parallel), totalling 13 degrees of freedom, and it is used to automatically align the probe onto a desired planned trajectory. The probe is then inserted in the brain, towards the planned target, by means of a haptic interface. This paper presents a new iterative targeting approach to be used in surgical robotic navigation, where the multi-robot chain is used to align the surgical probe to the planned pose, and an external sensor is used to decrease the alignment errors. The iterative targeting was tested in an operating room environment using a skull phantom, and the targets were selected on magnetic resonance images. The proposed targeting procedure allows about 0.3 mm to be obtained as the residual median Euclidean distance between the planned and the desired targets, thus satisfying the surgical accuracy requirements (1 mm), due to the resolution of the diffused medical images. The performances proved to be independent of the robot optical sensor calibration accuracy.

Penthrox inhaler analgesia in transrectal ultrasound-guided prostate biopsy.

PubMed

Lee, Chanyang; Woo, Henry H

2015-06-01

Periprostatic injection of local anaesthetic (PILA) has been shown to significantly reduce pain in patients undergoing transrectal ultrasound-guided prostate biopsy (TRUSPB). However, this method does not address pain that is associated with ultrasound probe insertion, and the injection of local anaesthetic itself causes pain. The aim of this study was to explore the efficacy of methoxyflurane delivered by a Penthrox inhaler as a novel method of pain relief during TRUSPB. From July 2012 to July 2013, 64 patients were scheduled at a single centre to undergo TRUSPB while receiving analgesia via Penthrox inhaler. Fifteen minutes after the biopsy procedure, these patients were asked to complete a pain score survey using a 10-cm visual analogue scale (VAS) to separately report the degree of pain experienced during digital rectal examination (DRE), ultrasound probe insertion and core biopsy. The median pain scores on a 10-cm VAS were 2.0, 2.4 and 3.0 during DRE, probe insertion and needle biopsy, respectively, while using the Penthrox inhaler. Of the 64 patients, 11 had undergone TRUSPB previously receiving PILA. In these patients, PILA was significantly better than the Penthrox inhaler for pain relief during needle biopsy (median pain score 2.0 versus 4.0; P = 0.012). The Penthrox inhaler appears to be a safe and effective method of analgesia for TRUSPB. Patients who had experienced both PILA and Penthrox reported pain scores that significantly favoured PILA over the Penthrox inhaler. © 2014 Royal Australasian College of Surgeons.

Waveguide-coupled resonator filters on AlN on silicon

NASA Technical Reports Server (NTRS)

Liaw, H. M.; Cameron, T. P.; Hunt, W. D.; Hickernell, F. S.

1994-01-01

In the effort to continually reduce the size and cost of wireless communications products the level of integration has improved dramatically in recent years. In order to reduce future generations of wireless systems to single chip form, there is a need for on-chip filtering capabilities. In this paper, the first report of an experimental waveguide-coupled resonator filter for cellular radio applications is presented. Measured results indicate a typical insertion loss of 26 dB at a center frequency of 132 MHz using a 2 um AlN film on (001) less than 110 greater than Si. In addition, a laser probe analysis has been conducted and a theoretical analysis of the first order reflection coefficients is presented.

The fast reciprocating magnetic probe system on the J-TEXT tokamak

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

Li, Fuming; Chen, Zhipeng, E-mail: zpchen@hust.edu.cn; Zhuang, Ge

The fast reciprocating magnetic probe (FRMP) system is newly developed on the Joint Texas Experimental Tokamak (J-TEXT) to measure the local magnetic fluctuations at the plasma edge. The magnetic probe array in the FRMP consists of four 2-dimensional magnetic probes arranged at different radial locations to detect local poloidal and radial magnetic fields. These probes are protected by a graphite and boron nitride casing to improve the frequency response of each probe; they are mounted on the head of a movable rod, which is oriented along radial direction at the top of the torus. In the experiments, multiple core diagnosticsmore » show that the insertion of the FRMP has little impact on the equilibrium of the plasma. Local magnetic fluctuations inside the last closed flux surface are successfully measured by the FRMP.« less

Flow quality experiment in a tandem nozzle wind tunnel at Mach 3

NASA Astrophysics Data System (ADS)

Wu, Jie; Zamre, Pradip; Radespiel, Rolf

2015-01-01

In this study, the disturbance characterization and flow quality improvement of a newly designed Tandem Nozzle Mach 3 Wind Tunnel are presented. Firstly, a combined modal analysis is conducted to characterize the freestream disturbances with initial set-up of the settling chamber by using a Pitot probe and a hot-wire anemometry. Then, disturbance reduction in the supersonic wind tunnel is investigated by inserting various damping materials into the settling chamber, while a Pitot probe instrumented with Kulite sensor is employed to monitor the variation of the Pitot pressure fluctuation in the test section. Eventually, an optimized configuration of the settling chamber is determined by a combination of certain damping materials. Afterward, the freestream disturbances are re-characterized with the optimized set-up of the settling chamber, and the disturbance level is found to be significantly reduced. Through this study, valuable experience has been acquired for the disturbance reduction in tandem nozzle type supersonic wind tunnel for the first time, which enhances the feasibility of extending the operation range of conventional hypersonic Ludwieg tubes.

Visual probes and methods for placing visual probes into subsurface areas

DOEpatents

Clark, Don T.; Erickson, Eugene E.; Casper, William L.; Everett, David M.

2004-11-23

Visual probes and methods for placing visual probes into subsurface areas in either contaminated or non-contaminated sites are described. In one implementation, the method includes driving at least a portion of a visual probe into the ground using direct push, sonic drilling, or a combination of direct push and sonic drilling. Such is accomplished without providing an open pathway for contaminants or fugitive gases to reach the surface. According to one implementation, the invention includes an entry segment configured for insertion into the ground or through difficult materials (e.g., concrete, steel, asphalt, metals, or items associated with waste), at least one extension segment configured to selectively couple with the entry segment, at least one push rod, and a pressure cap. Additional implementations are contemplated.

A fluorogenic probe for SNAP-tagged plasma membrane proteins based on the solvatochromic molecule Nile Red.

PubMed

Prifti, Efthymia; Reymond, Luc; Umebayashi, Miwa; Hovius, Ruud; Riezman, Howard; Johnsson, Kai

2014-03-21

A fluorogenic probe for plasma membrane proteins based on the dye Nile Red and SNAP-tag is introduced. It takes advantage of Nile Red, a solvatochromic molecule highly fluorescent in an apolar environment, such as cellular membranes, but almost dark in a polar aqueous environment. The probe possesses a tuned affinity for membranes allowing its Nile Red moiety to insert into the lipid bilayer of the plasma membrane, becoming fluorescent, only after its conjugation to a SNAP-tagged plasma membrane protein. The fluorogenic character of the probe was demonstrated for different SNAP-tag fusion proteins, including the human insulin receptor. This work introduces a new approach for generating a powerful turn-on probe for "no-wash" labeling of plasma membrane proteins with numerous applications in bioimaging.

Real time sensor for therapeutic radiation delivery

DOEpatents

Bliss, M.; Craig, R.A.; Reeder, P.L.

1998-01-06

The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body. 14 figs.

Real time sensor for therapeutic radiation delivery

DOEpatents

Bliss, Mary; Craig, Richard A.; Reeder, Paul L.

1998-01-01

The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body.

Probing and Tapping: Are We Inserting Pedicle Screws Correctly?

PubMed

Prasad, Vishal; Mesfin, Addisu; Lee, Robert; Reigrut, Julie; Schmidt, John

2016-11-01

Although there are a significant number of research publications on the topic of bone morphology and the strength of bone, the clinical significance of a failed pedicle screw is often revision surgery and the potential for further postoperative complications; especially in elderly patients with osteoporotic bone. The purpose of this report is to quantify the mechanical strength of the foam-screw interface by assessing probe/pilot hole diameter and tap sizes using statistically relevant sample sizes under highly controlled test conditions. The study consisted of two experiments and used up to three different densities of reference-grade polyurethane foam (ASTM 1839), including 0.16, 0.24, and 0.32 g/cm 3 . All screws and rods were provided by K2M Inc. and screws were inserted to a depth of 25 mm. A series of pilot holes, 1.5, 2.2, 2.7, 3.2, 3.7, 4.2, 5.0, and 6.0 mm in diameter were drilled through the entire depth of the material. A 6.5 × 45-mm pedicle screw was inserted and axially pulled from the material (n = 720). A 3.0-mm pilot hole was drilled and tapped with: no tap, 3.5-, 4.5-, 5.5-, and 6.5-mm taps. A 6.5 × 45-mm pedicle screw was inserted and axially pulled from the material (n = 300). The size of the probe/pilot hole had a nonlinear, parabolic effect on pullout strength. This shape suggests an optimum-sized probe hole for a given size pedicle screw. Too large or too small of a probe hole causes a rapid falloff in pullout strength. The tap data demonstrated that not tapping and undertapping by two or three sizes did not significantly alter the pullout strength of the screws. The data showed an exponential falloff of pullout strength when as tap size increased to the diameter of the screw. In the current study, the data show that an ideal pilot hole size half the diameter of the screw is a starting point. Also, that if tapping was necessary, to use a tap two sizes smaller than the screw being implanted. A similar optimum pilot hole or tap size may be expected in the clinical scenario, however, it may not be the same as seen with the uniform density polyurethane foam tested in the current study. Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Isolation of an insertion sequence (IS1051) from Xanthomonas campestris pv. dieffenbachiae with potential use for strain identification and characterization.

PubMed Central

Berthier, Y; Thierry, D; Lemattre, M; Guesdon, J L

1994-01-01

A new insertion sequence was isolated from Xanthomonas campestris pv. dieffenbachiae. Sequence analysis showed that this element is 1,158 bp long and has 15-bp inverted repeat ends containing two mismatches. Comparison of this sequence with sequences in data bases revealed significant homology with Escherichia coli IS5. IS1051, which detected multiple restriction fragment length polymorphisms, was used as a probe to characterize strains from the pathovar dieffenbachiae. Images PMID:7906933

The use of endoillumination probe-assisted Descemet membrane endothelial keratoplasty for bullous keratopathy secondary to argon laser iridotomy

PubMed Central

Kobayashi, Akira; Yokogawa, Hideaki; Yamazaki, Natsuko; Masaki, Toshinori; Sugiyama, Kazuhisa

2015-01-01

Purpose To report the first case of Descemet membrane endothelial keratoplasty (DMEK) for bullous keratopathy (BK) secondary to argon laser iridotomy (ALI). Patient A 71-year-old woman presented with decreased visual acuity in her right eye due to BK secondary to ALI that was performed 10 years prior. Results Phacosurgery was performed first, followed by successful DMEK 4 months later. A DMEK shooter was used for donor insertion, which allowed for a stable anterior chamber during donor insertion, even when the anterior chamber was quite shallow. Also, removal of edematous epithelial cells and endoillumination probe-assisted DMEK was quite useful to visualize DMEK graft on the background of the dark brown iris seen in Asian eyes. The patient’s best corrected visual acuity rapidly increased from 20/200 to 25/20 after 1 month, with complete resolution of corneal edema. Conclusion We reported the first successful DMEK case for BK secondary to ALI. The use of a DMEK shooter for donor insertion and endoillumination assistance to visualize the DMEK graft was a useful technique for BK secondary to ALI. PMID:25609910

Lens-free all-fiber probe with an optimized output beam for optical coherence tomography.

PubMed

Ding, Zhihua; Qiu, Jianrong; Shen, Yi; Chen, Zhiyan; Bao, Wen

2017-07-15

A high-efficiency lensless all-fiber probe for optical coherence tomography (OCT) is presented. The probe is composed of a segment of large-core multimode fiber (MMF), a segment of tapered MMF, and a length of single-mode fiber (SMF). A controllable output beam can be designed by a simple adjustment of its probe structure parameters (PSPs), instead of the selection of fibers with different optical parameters. A side-view probe with a diameter of 340 μm and a rigid length of 6.37 mm was fabricated, which provides an effective imaging range of ∼0.6  mm with a full width at half-maximum beam diameter of less than 30 μm. The insertion loss of the probe was measured to be 0.81 dB, ensuring a high sensitivity of 102.25 dB. Satisfactory images were obtained by the probe-based OCT system, demonstrating the feasibility of the probe for endoscopic OCT applications.

Method for introducing unidirectional nested deletions

DOEpatents

Dunn, John J.; Quesada, Mark A.; Randesi, Matthew

2001-01-01

Disclosed is a method for the introduction of unidirectional deletions in a cloned DNA segment in the context of a cloning vector which contains an f1 endonuclease recognition sequence adjacent to the insertion site of the DNA segment. Also disclosed is a method for producing single-stranded DNA probes utilizing the same cloning vector. An optimal vector, PZIP is described. Methods for introducing unidirectional deletions into a terminal location of a cloned DNA sequence which is inserted into the vector of the present invention are also disclosed. These methods are useful for introducing deletions into either or both ends of a cloned DNA insert, for high throughput sequencing of any DNA of interest.

Forskolin-induced apical membrane insertion of virally expressed, epitope-tagged CFTR in polarized MDCK cells.

PubMed

Howard, M; Jiang, X; Stolz, D B; Hill, W G; Johnson, J A; Watkins, S C; Frizzell, R A; Bruton, C M; Robbins, P D; Weisz, O A

2000-08-01

Channel gating of the cystic fibrosis transmembrane conductance regulator (CFTR) is activated in response to cAMP stimulation. In addition, CFTR activation may also involve rapid insertion of a subapical pool of CFTR into the plasma membrane (PM). However, this issue has been controversial, in part because of the difficulty in distinguishing cell surface vs. intracellular CFTR. Recently, a fully functional, epitope-tagged form of CFTR (M2-901/CFTR) that can be detected immunologically in nonpermeabilized cells was characterized (Howard M, Duvall MD, Devor DC, Dong J-Y, Henze K, and Frizzell RA. Am J Physiol Cell Physiol 269: C1565-C1576, 1995; and Schultz BD, Takahashi A, Liu C, Frizzell RA, and Howard M. Am J Physiol Cell Physiol 273: C2080-C2089, 1997). We have developed replication-defective recombinant adenoviruses that express M2-901/CFTR and used them to probe cell surface CFTR in forskolin (FSK)-stimulated polarized Madin-Darby canine kidney (MDCK) cells. Virally expressed M2-901/CFTR was functional and was readily detected on the apical surface of FSK-stimulated polarized MDCK cells. Interestingly, at low multiplicity of infection, we observed FSK-stimulated insertion of M2901/CFTR into the apical PM, whereas at higher M2-901/CFTR expression levels, no increase in surface expression was detected using indirect immunofluorescence. Immunoelectron microscopy of unstimulated and FSK-stimulated cells confirmed the M2-901/CFTR redistribution to the PM upon FSK stimulation and demonstrates that the apically inserted M2-901/CFTR originates from a population of subapical vesicles. Our observations may reconcile previous conflicting reports regarding the effect of cAMP stimulation on CFTR trafficking.

Spectroscopic study of fluorescent probes based on G-quadruplex oligonucleotides labeled with ethynylpyrenyldeoxyuridine.

PubMed

Switalska, Angelika; Kierzek, Ryszard; Dembska, Anna; Juskowiak, Bernard

2017-12-01

The design, synthesis, and spectral properties of four pyrene labeled oligonucleotide probes with G-quadruplex structure (Tel22-Tpy, Tel22-Upy, Tel22-6Upy, Tel22-18Upy) based on the 22-mer human telomeric sequence (Tel22) have been reported. Pyrene labels in the form of ethynylpyrenyldeoxyuridine have been inserted efficiently into oligodeoxynucleotides probes using phosphoramidite chemistry. The probes exhibited abilities to fold into G-quadruplex structures and to bind metal cations (Na + and K + ). Folding properties of probes and their spectral behavior were examined by recording the UV-vis, fluorescence, and CD spectra as well as by analyzing melting profiles. Fluorescence characteristics and G-quadruplex folding of probes were also studied at the interface of cationic dioctadecyldimethylammonium bromide (DODAB) monolayer. Investigations included film balance measurements (π-A isotherms) and fluorescence spectra recording using a fiber optic accessory interfaced with a spectrofluorimeter. Copyright © 2017 Elsevier B.V. All rights reserved.

Method and system for fiber optic determination of gas concentrations in liquid receptacles

NASA Technical Reports Server (NTRS)

Nguyen, Quang-Viet (Inventor)

2008-01-01

A system for determining gas compositions includes a probe, inserted into a source of gaseous material, the probe having a gas permeable sensor tip and being capable of sending and receiving light to and from the gaseous material, a sensor body, connected to the probe, situated outside of the source and a fiber bundle, connected to the sensor body and communicating light to and from the probe. The system also includes a laser source, connected to one portion of the fiber bundle and providing laser light to the fiber bundle and the probe a Raman spectrograph, connected to another portion of the fiber bundle, receiving light from the probe and filtering the received light into specific channels and a data processing unit, receiving and analyzing the received light in the specific channels and outputting concentration of specific gas species in the gaseous material based on the analyzed received light.

Bioactive nitric oxide concentration does not increase during reactive hyperemia in human skin.

PubMed

Zhao, J L; Pergola, P E; Roman, L J; Kellogg, D L

2004-02-01

This study examined whether nitric oxide (NO) is involved in the cutaneous response to reactive hyperemia (RH) in the human forearm. We enrolled seven healthy volunteers. NO concentrations were monitored using a NO selective amperometric electrode (ISO-NOP200, World Precision Instruments) inserted into the skin of the forearm. Laser-Doppler flowmetry (Moor Instruments) was used for monitoring skin blood flow (SkBF) at the same site. SkBF and NO levels were monitored and recorded continuously throughout the experiment. An intradermal microdialysis probe was inserted adjacent to the NO electrode for drug delivery. Data collection began 140 min after the NO electrodes and microdialysis probes were inserted. RH was achieved by the inflation of a blood pressure cuff to 25 mmHg above systolic pressure for 7 min after which the pressure in the cuff was abruptly released. Acetylcholine (ACh) was given by microdialysis probe at the end of RH study to verify the ability of the electrode system to detect changes in the NO concentration. SkBF and NO data before RH and immediately, 2, 5, 7, and 10 min after cuff deflation were used for analysis. SkBF increased immediately after release of the occlusion (P < 0.0001) and remained elevated for 2 min. No significant NO changes occurred with the increases in LDF. ACh induced increases in both SkBF and NO (P < 0.000 and P < 0.037, respectively). We conclude that RH increases SkBF by mechanisms that do not require a measurable increase in NO concentrations.

Physical mapping of complex genomes

DOEpatents

Evans, Glen A.

1993-01-01

Method for simultaneous identification of overlapping cosmid clones among multiple cosmid clones and the use of the method for mapping complex genomes are provided. A library of cosmid clones that contains the DNA to be mapped is constructed and arranged in a manner such that individual clones can be identified and replicas of the arranged clones prepared. In preferred embodiments, the clones are arranged in a two dimensional matrix. In such embodiments, the cosmid clones in a row are pooled, mixed probes complementary to the ends of the DNA inserts int he pooled clones are synthesized, hybridized to a first replica of the library. Hybridizing clones, which include the pooled row, are identified. A second portion of clones is prepared by pooling cosmid clones that correspond to a column in the matrix. The second pool thereby includes one clone from the first portion pooled clones. This common clone is located on the replica at the intersection of the column and row. Mixed probes complementary to the ends of the DNA inserts in the second pooled portion of clones are prepared and hybridized to a second replica of the library. The hybridization pattern on the first and second replicas of the library are compared and cross-hybridizing clones, other than the clones in the pooled column and row, that hybridize to identical clones in the first and second replicas are identified. These clones necessarily include DNA inserts that overlap with the DNA insert int he common clone located at the intersection of the pooled row and pooled column. The DNA in the entire library may be mapped by pooling the clones in each of the rows and columns of the matrix, preparing mixed end-specific probes and hybridizing the probes from each row or column to a replica of the library. Since all clones in the library are located at the intersection of a column and a row, the overlapping clones for all clones in the library may be identified and a physical map constructed. In other preferred embodiments, the cosmid clones are arranged in a three dimensional matrix, pooled and compared in threes according to intersecting planes of the three dimensional matrix. Arrangements corresponding to geometries of higher dimensions may also be prepared and used to simultaneously identify overlapping clones in highly complex libraries with relatively few hybridization reactions.

A review on mechanical considerations for chronically-implanted neural probes

NASA Astrophysics Data System (ADS)

Lecomte, Aziliz; Descamps, Emeline; Bergaud, Christian

2018-06-01

This review intends to present a comprehensive analysis of the mechanical considerations for chronically-implanted neural probes. Failure of neural electrical recordings or stimulation over time has shown to arise from foreign body reaction and device material stability. It seems that devices that match most closely with the mechanical properties of the brain would be more likely to reduce the mechanical stress at the probe/tissue interface, thus improving body acceptance. The use of low Young’s modulus polymers instead of hard substrates is one way to enhance this mechanical mimetism, though compliance can be achieved through a variety of means. The reduction of probe width and thickness in comparison to a designated length, the use of soft hydrogel coatings and the release in device tethering to the skull, can also improve device compliance. Paradoxically, the more compliant the device, the more likely it will fail during the insertion process in the brain. Strategies have multiplied this past decade to offer partial or temporary stiffness to the device to overcome this buckling effect. A detailed description of the probe insertion mechanisms is provided to analyze potential sources of implantation failure and the need for a mechanically-enhancing structure. This leads us to present an overview of the strategies that have been put in place over the last ten years to overcome buckling issues. Particularly, great emphasis is put on bioresorbable polymers and their assessment for neural applications. Finally, a discussion is provided on some of the key features for the design of mechanically-reliable, polymer-based next generation of chronic neuroprosthetic devices.

Design and fabrication of PZN-7%PT single crystal high frequency angled needle ultrasound transducers.

PubMed

Zhou, Qifa; Wu, Dawei; Jin, Jing; Hu, Chang-hong; Xu, Xiaochen; Williams, Jay; Cannata, Jonathan M; Lim, Leongchew; Shung, K Kirk

2008-01-01

A high-frequency angled needle ultrasound transducer with an aperture size of 0.4 x 0.56 mm2 was fabricated using a lead zinc niobate-lead titanate (PZN- 7%PT) single crystal as the active piezoelectric material. The single crystal was bonded to a conductive silver particle matching layer and a conductive epoxy backing material through direct contact curing. A parylene outer matching layer was formed by vapor deposition. Angled needle probe configuration was achieved by dicing at 45 degrees to the single crystal poling direction to satisfy a clinical request for blood flow measurement in the posterior portion of the eye. The electrical impedance magnitude and phase of the transducer were 42 Omega and -63 degrees , respectively. The measured center frequency and the fractional bandwidth at -6 dB were 43 MHz and 45%, respectively. The two-way insertion loss was approximately 17 dB. Wire phantom imaging using fabricated PZN-7%PT single crystal transducers was obtained and spatial resolutions were assessed.

The Phoenix Mars Lander Robotic Arm

NASA Technical Reports Server (NTRS)

Bonitz, Robert; Shiraishi, Lori; Robinson, Matthew; Carsten, Joseph; Volpe, Richard; Trebi-Ollennu, Ashitey; Arvidson, Raymond E.; Chu, P. C.; Wilson, J. J.; Davis, K. R.

2009-01-01

The Phoenix Mars Lander Robotic Arm (RA) has operated for over 150 sols since the Lander touched down on the north polar region of Mars on May 25, 2008. During its mission it has dug numerous trenches in the Martian regolith, acquired samples of Martian dry and icy soil, and delivered them to the Thermal Evolved Gas Analyzer (TEGA) and the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The RA inserted the Thermal and Electrical Conductivity Probe (TECP) into the Martian regolith and positioned it at various heights above the surface for relative humidity measurements. The RA was used to point the Robotic Arm Camera to take images of the surface, trenches, samples within the scoop, and other objects of scientific interest within its workspace. Data from the RA sensors during trenching, scraping, and trench cave-in experiments have been used to infer mechanical properties of the Martian soil. This paper describes the design and operations of the RA as a critical component of the Phoenix Mars Lander necessary to achieve the scientific goals of the mission.

X-ray computed microtomography characterizes the wound effect that causes sap flow underestimation by thermal dissipation sensors.

PubMed

Marañón-Jiménez, S; Van den Bulcke, J; Piayda, A; Van Acker, J; Cuntz, M; Rebmann, C; Steppe, K

2018-02-01

Insertion of thermal dissipation (TD) sap flow sensors in living tree stems causes damage of the wood tissue, as is the case with other invasive methods. The subsequent wound formation is one of the main causes of underestimation of tree water-use measured by TD sensors. However, the specific alterations in wood anatomy in response to inserted sensors have not yet been characterized, and the linked dysfunctions in xylem conductance and sensor accuracy are still unknown. In this study, we investigate the anatomical mechanisms prompting sap flow underestimation and the dynamic process of wound formation. Successive sets of TD sensors were installed in the early, mid and end stage of the growing season in diffuse- and ring-porous trees, Fagus sylvatica (Linnaeus) and Quercus petraea ((Mattuschka) Lieblein), respectively. The trees were cut in autumn and additional sensors were installed in the cut stem segments as controls without wound formation. The wounded area and volume surrounding each sensor was then visually determined by X-ray computed microtomography (X-ray microCT). This technique allowed the characterization of vessel anatomical transformations such as tyloses formation, their spatial distribution and quantification of reduction in conductive area. MicroCT scans showed considerable formation of tyloses that reduced the conductive area of vessels surrounding the inserted TD probes, thus causing an underestimation in sap flux density (SFD) in both beech and oak. Discolored wood tissue was ellipsoidal, larger in the radial plane, more extensive in beech than in oak, and also for sensors installed for longer times. However, the severity of anatomical transformations did not always follow this pattern. Increased wound size with time, for example, did not result in larger SFD underestimation. This information helps us to better understand the mechanisms involved in wound effects with TD sensors and allows the provision of practical recommendations to reduce biases associated with wounding in field sap flow measurements. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Probing for Binding Regions of the FtsZ Protein Surface through Site-Directed Insertions: Discovery of Fully Functional FtsZ-Fluorescent Proteins

PubMed Central

Moore, Desmond A.; Whatley, Zakiya N.; Joshi, Chandra P.; Osawa, Masaki

2016-01-01

ABSTRACT FtsZ, a bacterial tubulin homologue, is a cytoskeletal protein that assembles into protofilaments that are one subunit thick. These protofilaments assemble further to form a “Z ring” at the center of prokaryotic cells. The Z ring generates a constriction force on the inner membrane and also serves as a scaffold to recruit cell wall remodeling proteins for complete cell division in vivo. One model of the Z ring proposes that protofilaments associate via lateral bonds to form ribbons; however, lateral bonds are still only hypothetical. To explore potential lateral bonding sites, we probed the surface of Escherichia coli FtsZ by inserting either small peptides or whole fluorescent proteins (FPs). Among the four lateral surfaces on FtsZ protofilaments, we obtained inserts on the front and back surfaces that were functional for cell division. We concluded that these faces are not sites of essential interactions. Inserts at two sites, G124 and R174, located on the left and right surfaces, completely blocked function, and these sites were identified as possible sites for essential lateral interactions. However, the insert at R174 did not interfere with association of protofilaments into sheets and bundles in vitro. Another goal was to find a location within FtsZ that supported insertion of FP reporter proteins while allowing the FtsZ-FPs to function as the sole source of FtsZ. We discovered one internal site, G55-Q56, where several different FPs could be inserted without impairing function. These FtsZ-FPs may provide advances for imaging Z-ring structure by superresolution techniques. IMPORTANCE One model for the Z-ring structure proposes that protofilaments are assembled into ribbons by lateral bonds between FtsZ subunits. Our study excluded the involvement of the front and back faces of the protofilament in essential interactions in vivo but pointed to two potential lateral bond sites, on the right and left sides. We also identified an FtsZ loop where various fluorescent proteins could be inserted without blocking function; these FtsZ-FPs functioned as the sole source of FtsZ. This advance provides improved tools for all fluorescence imaging of the Z ring and may be especially important for superresolution imaging. PMID:27795325

System design of the Pioneer Venus spacecraft. Volume 11: Launch vehicle utilization

NASA Technical Reports Server (NTRS)

Varga, R. J.

1973-01-01

A summary of the spacecraft descriptions; the probe bus, large probe, small probe, and orbiter is presented. The highlights on the designs of the Atlas/Centaur spacecraft as compared to the corresponding Thor/Delta spacecraft designs are contained. A comparison is made of the two Atlas/Centaur spacecraft for reference. The major differences are the replacement of the probes of the forward end of the probe bus with the mechanically despun antenna of the orbiter and the replacement of the bicone antenna on the aft end with the orbit insertion motor. The cross sections of the large and small probes are compared. The major features of each probe are described. The Thor/Delta and Atlas/Centaur designs for the probe bus and orbiter are analyzed. The usable spacecraft mass for the Atlas/Centaur is roughly twice that for the Thor/Delta if the Type I trajectory is assumed. It is somewhat less for the Type II trajectory in the designated launch years. This additional mass capability leads to cost savings in many areas which are described.

The influence on response of axial rotation of a six-group local-conductance probe in horizontal oil-water two-phase flow

NASA Astrophysics Data System (ADS)

Weihang, Kong; Lingfu, Kong; Lei, Li; Xingbin, Liu; Tao, Cui

2017-06-01

Water volume fraction is an important parameter of two-phase flow measurement, and it is an urgent task for accurate measurement in horizontal oil field development and optimization of oil production. The previous ring-shaped conductance water-cut meter cannot obtain the response values corresponding to the oil field water conductivity for oil-water two-phase flow in horizontal oil-producing wells characterized by low yield liquid, low velocity and high water cut. Hence, an inserted axisymmetric array structure sensor, i.e. a six-group local-conductance probe (SGLCP), is proposed in this paper. Firstly, the electric field distributions generated by the exciting electrodes of SGLCP are investigated by the finite element method (FEM), and the spatial sensitivity distributions of SGLCP are analyzed from the aspect of different separations between two electrodes and different axial rotation angles respectively. Secondly, the numerical simulation responses of SGLCP in horizontal segregated flow are calculated from the aspect of different water cut and heights of the water layer, respectively. Lastly, an SGLCP-based well logging instrument was developed, and experiments were carried out in a horizontal pipe with an inner diameter of 125 mm on the industrial-scale experimental multiphase flow setup in the Daqing Oilfield, China. In the experiments, the different oil-water two-phase flow, mineralization degree, temperature and pressure were tested. The results obtained from the simulation experiments and simulation well experiments demonstrate that the designed and developed SGLCP-based instrument still has a good response characteristic for measuring water conductivity under the different conditions mentioned above. The validity and reliability of obtaining the response values corresponding to the water conductivity through the designed and developed SGLCP-based instrument are verified by the experimental results. The significance of this work can provide an effective technology for measuring the water volume fraction of oil-water two-phase flow in horizontal oil-producing wells.

A microfluidic brain slice perfusion chamber for multisite recording using penetrating electrodes.

PubMed

Blake, Alexander J; Rodgers, Frank C; Bassuener, Anna; Hippensteel, Joseph A; Pearce, Thomas M; Pearce, Timothy R; Zarnowska, Ewa D; Pearce, Robert A; Williams, Justin C

2010-05-30

To analyze the spatiotemporal dynamics of network activity in a brain tissue slice, it is useful to record simultaneously from multiple locations. When obtained from laminar structures such as the hippocampus or neocortex, multisite recordings also yield information about subcellular current distributions via current source density analysis. Multisite probes developed for in vivo recordings could serve these purposes in vitro, allowing recordings to be obtained from brain slices at sites deeper within the tissue than currently available surface recording methods permit. However, existing recording chambers do not allow for the insertion of lamina-spanning probes that enter through the edges of brain slices. Here, we present a novel brain slice recording chamber design that accomplishes this goal. The device provides a stable microfluidic perfusion environment in which tissue health is optimized by superfusing both surfaces of the slice. Multichannel electrodes can be inserted parallel to the surface of the slice, at any depth relative to the surface. Access is also provided from above for the insertion of additional recording or stimulating electrodes. We illustrate the utility of this recording configuration by measuring current sources and sinks during theta burst stimuli that lead to the induction of long-term potentiation in hippocampal slices. (c) 2010 Elsevier B.V. All rights reserved.

An insertion approach electrochemical aptasensor for mucin 1 detection based on exonuclease-assisted target recycling.

PubMed

Wen, Wei; Hu, Rong; Bao, Ting; Zhang, Xiuhua; Wang, Shengfu

2015-09-15

In this work, a sensitive exonuclease-assisted amplification electrochemical aptasensor through insertion approach was developed for the detection of mucin 1 (MUC 1). In order to construct the aptasensor, 6-Mercapto-1-hexanol (MCH) was used to block partial sites of gold electrode (GE), followed by thiolated capture probe self-assembled on GE. Methylene blue (MB) labeled aptamer hybridized with capture probe at both ends to form double-strand DNA. For the MB labeled termini was close to GE, the electrochemical response was remarkable. The presence of MUC 1 caused the dissociation of the double-strand DNA owing to the specific recognition of aptamer to MUC 1. Then exonuclease I (Exo I) selectively digested the aptamer which bound with MUC 1, the released MUC 1 participated new binding with the rest aptamer. Insertion approach improved the reproducibility and Exo I-catalyzed target recycling improved the sensitivity of the aptasensor significantly. Under optimal experimental conditions, the proposed aptasensor had a good linear correlation ranged from 10 pM to 1 μM with a detection limit of 4 pM (Signal to Noise ratio, S/N=3). The strategy had great potential for the simple and sensitive detection of other cancer markers. Copyright © 2015 Elsevier B.V. All rights reserved.

Damping insert materials for settling chambers of supersonic wind tunnels

NASA Astrophysics Data System (ADS)

Wu, Jie; Radespiel, Rolf

2017-03-01

This study describes the application of a novel damping insert material for reducing the flow fluctuations in a tandem nozzle supersonic wind tunnel. This new damping material is composed of multi-layer stainless steel wired meshes. The influences of the multi-layer mesh, such as the quantity of the mesh layer and the installed location in the settling chamber, to the freestream quality have been investigated. A Pitot probe instrumented with a Kulite pressure sensor and a hot-wire probe are employed to monitor the flow fluctuation in the test section of the wind tunnel. Thereafter, a combined modal analysis is applied for the disturbance qualification. Additionally, the transient Mach number in the test section is measured. The disturbance qualification indicates that the multi-layer mesh performs well in providing reduction of vorticity reduction and acoustic fluctuations. Comparable flow quality of the freestream was also obtained using a combination of flexible damping materials. However, the life-span of the new damping materials is much longer. The time transient of the Mach number measured in the test section indicates that the mean flow is rather constant over run time. Furthermore, the time-averaged pressure along the settling chamber is recorded and it shows the distribution of pressure drop by settling chamber inserts.

Apparatus and method of capturing an orbiting spacecraft

NASA Technical Reports Server (NTRS)

Harwell, William D. (Inventor); Gardner, Dale A. (Inventor)

1987-01-01

Apparatus and a method of capturing an orbiting spacecraft by attaching a grapple fixture are discussed. A probe is inserted into an opening, such as a rocket nozzle, in the spacecraft until a stop on the prove mechanism contacts the spacecraft. A lever is actuated releasing a spring loaded rod which moves axially along the probe removing a covering sleeve to expose spring loaded toffle fingers which pivot open engaging the side of the opening. The probe is shortened and tensioned by turning a screw thread, pressing the fingers inside of the opening to compress the spacecraft between the toggle fingers and the stop. A grapple fixture attached to the probe, which is thus secured to the spacecraft, is engaged by appropriate retrieval means such as a remote manipulator arm.

Design and testing of an endoscopic photoacoustic probe for determination of treatment depth after photodynamic therapy

NASA Astrophysics Data System (ADS)

Viator, John A.; Paltauf, Guenther; Jacques, Steven L.; Prahl, Scott A.

2001-06-01

An endoscopic photoacoustic probe is designed and tested for use in PDT treatment of esophageal cancer. The probe, measuring less than 2.5 mm in diameter, was designed to fit within the lumen of an endoscope that will be inserted into an esophagus after PDT. PDT treatment results in a blanched, necrotic layer of cancerous tissue over a healthy, deeper layer of perfused tissue. The photoacoustic probe was designed to use acoustic propagation time to determine the thickness of the blanched surface of the esophagus, which corresponds to treatment depth. A side-firing 600 micrometers fiber delivered 532 nm laser light to induce acoustic waves in the perfused layer of the esophagus beneath the blanched (treated) layer. A PVDF transducer detected the induced acoustic waves and transmitted the signal to an oscilloscope. The probe was tested on clear and turbid tissue phantom layers over an optically absorbing dye solution.

Nanoneedle insertion into the cell nucleus does not induce double-strand breaks in chromosomal DNA.

PubMed

Ryu, Seunghwan; Kawamura, Ryuzo; Naka, Ryohei; Silberberg, Yaron R; Nakamura, Noriyuki; Nakamura, Chikashi

2013-09-01

An atomic force microscope probe can be formed into an ultra-sharp cylindrical shape (a nanoneedle) using micro-fabrication techniques such as focused ion beam etching. This nanoneedle can be effectively inserted through the plasma membrane of a living cell to not only access the cytosol, but also to penetrate through the nuclear membrane. This technique shows great potential as a tool for performing intranuclear measurements and manipulations. Repeated insertions of a nanoneedle into a live cell were previously shown not to affect cell viability. However, the effect of nanoneedle insertion on the nucleus and nuclear components is still unknown. DNA is the most crucial component of the nucleus for proper cell function and may be physically damaged by a nanoneedle. To investigate the integrity of DNA following nanoneedle insertion, the occurrence of DNA double-strand breaks (DSBs) was assessed. The results showed that there was no chromosomal DNA damage due to nanoneedle insertion into the nucleus, as indicated by the expression level of γ-H2AX, a molecular marker of DSBs. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Detection of beer spoilage bacteria Pectinatus and Megasphaera with acridinium ester labelled DNA probes using a hybridisation protection assay.

PubMed

Paradh, A D; Hill, A E; Mitchell, W J

2014-01-01

DNA probes specific for rRNA of selected target species were utilised for the detection of beer spoilage bacteria of the genera Pectinatus and Megasphaera using a hybridisation protection assay (HPA). All the probes were modified during synthesis by addition of an amino linker arm at the 5' end or were internally modified by inserting an amine modified thymidine base. Synthesised probes then were labelled with acridinium ester (AE) and purified using reverse phase HPLC. The internally AE labelled probes were able to detect target RNA within the range of 0.016-0.0032pmol. All the designed probes showed high specificity towards target RNA and could detect bacterial contamination within the range of ca. 5×10(2)1×10(3) CFU using the HPA. The developed assay was also compatible with MRS, NBB and SMMP beer enrichment media, routinely used in brewing laboratories. © 2013 Elsevier B.V. All rights reserved.

Electrical capacitance clearanceometer

NASA Technical Reports Server (NTRS)

Hester, Norbert J. (Inventor); Hornbeck, Charles E. (Inventor); Young, Joseph C. (Inventor)

1992-01-01

A hot gas turbine engine capacitive probe clearanceometer is employed to measure the clearance gap or distance between blade tips on a rotor wheel and its confining casing under operating conditions. A braze sealed tip of the probe carries a capacitor electrode which is electrically connected to an electrical inductor within the probe which is inserted into a turbine casing to position its electrode at the inner surface of the casing. Electrical power is supplied through a voltage controlled variable frequency oscillator having a tuned circuit in which the probe is a component. The oscillator signal is modulated by a change in electrical capacitance between the probe electrode and a passing blade tip surface while an automatic feedback correction circuit corrects oscillator signal drift. A change in distance between a blade tip and the probe electrode is a change in capacitance therebetween which frequency modulates the oscillator signal. The modulated oscillator signal which is then processed through a phase detector and related circuitry to provide an electrical signal is proportional to the clearance gap.

Effects of lithium insertion on thermal conductivity of silicon nanowires

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

Xu, Wen; Institute of High Performance Computing, A*STAR, Singapore, Singapore 138632; Zhang, Gang, E-mail: zhangg@ihpc.a-star.edu.sg

2015-04-27

Recently, silicon nanowires (SiNWs) have been applied as high-performance Li battery anodes, since they can overcome the pulverization and mechanical fracture during lithiation. Although thermal stability is one of the most important parameters that determine safety of Li batteries, thermal conductivity of SiNWs with Li insertion remains unclear. In this letter, using molecular dynamics simulations, we study room temperature thermal conductivity of SiNWs with Li insertion. It is found that compared with the pristine SiNW, there is as much as 60% reduction in thermal conductivity with 10% concentration of inserted Li atoms, while under the same impurity concentration the reductionmore » in thermal conductivity of the mass-disordered SiNW is only 30%. With lattice dynamics calculations and normal mode decomposition, it is revealed that the phonon lifetimes in SiNWs decrease greatly due to strong scattering of phonons by vibrational modes of Li atoms, especially for those high frequency phonons. The observed strong phonon scattering phenomenon in Li-inserted SiNWs is similar to the phonon rattling effect. Our study serves as an exploration of thermal properties of SiNWs as Li battery anodes or weakly coupled with impurity atoms.« less

Effects of lithium insertion on thermal conductivity of silicon nanowires

NASA Astrophysics Data System (ADS)

Xu, Wen; Zhang, Gang; Li, Baowen

2015-04-01

Recently, silicon nanowires (SiNWs) have been applied as high-performance Li battery anodes, since they can overcome the pulverization and mechanical fracture during lithiation. Although thermal stability is one of the most important parameters that determine safety of Li batteries, thermal conductivity of SiNWs with Li insertion remains unclear. In this letter, using molecular dynamics simulations, we study room temperature thermal conductivity of SiNWs with Li insertion. It is found that compared with the pristine SiNW, there is as much as 60% reduction in thermal conductivity with 10% concentration of inserted Li atoms, while under the same impurity concentration the reduction in thermal conductivity of the mass-disordered SiNW is only 30%. With lattice dynamics calculations and normal mode decomposition, it is revealed that the phonon lifetimes in SiNWs decrease greatly due to strong scattering of phonons by vibrational modes of Li atoms, especially for those high frequency phonons. The observed strong phonon scattering phenomenon in Li-inserted SiNWs is similar to the phonon rattling effect. Our study serves as an exploration of thermal properties of SiNWs as Li battery anodes or weakly coupled with impurity atoms.

NcoI and TaqI RFLPs for human M creatine kinase (CKM)

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

Perryman, M.B.; Hejtmancik, J.F.; Ashizawa, Tetsuo

1988-09-12

Probe pHMCKUT contains a 135 bp cDNA fragment inserted into pGEM 3. The probe corresponds to nucleotides 1,201 to 1,336 located in the 3{prime} untranslated region of human M creatine kinase. The probe is specific for human M creatine kinase and does not hybridize to human B cretine kinase sequences. NcoI identifies a two allele polymorphism of a band at either 2.5 kb or 3.6 kb. TaqI identifies a two allele polymorphism at either 3.8 kb or 4.5 kb. Human M creatine has been localized to chromosome 19q. Autosomal co-dominant inheritance was shown in six informative Caucasian families.

The Rosetta Stones of Mars — Should Meteorites be Considered as Samples of Opportunity for Mars Sample Return?

NASA Astrophysics Data System (ADS)

Tait, A. W.; Schröder, C.; Ashley, J. W.; Velbel, M. A.; Boston, P. J.; Carrier, B. L.; Cohen, B. A.; Bland, P. A.

2018-04-01

We summarize insights about Mars gained from investigating meteorites found on Mars. Certain types of meteorites can be considered standard probes inserted into the martian environment. Should they be considered for Mars Sample Return?

Noise elimination method using a transmission line for the diagnostics of radio frequency plasma

NASA Astrophysics Data System (ADS)

Shimizu, K.; Hallil, A.; Amemiya, H.

1997-04-01

A filter using a transmission line formed by a cascade connection of inverted L-type networks has been developed to reject the distortion of the probe characteristics by rf (radio-frequency) noise. Each inverse L network consists of two coaxial cables with the same physical constant and length. The filter can remove discrete frequency components including the fundamental and harmonic components, the cut-off frequencies being determined by the distributed circuit constant and the length of the cables. By inserting different kinds of the network in cascade, many noise components associated with the rf frequency can be eliminated at the end section of the filter. Experiments have been performed in rf plasmas by inserting three kinds of inverted L networks with the frequency f (13.56 MHz), 2 f and 4f as the cut-off frequency. Distortion free probe characteristics have been obtained, from which accurate determination of plasma parameter such as the electron energy distribution is possible.

Durable fiber optic sensor for gas temperature measurement in the hot section of turbine engines

NASA Astrophysics Data System (ADS)

Tregay, George W.; Calabrese, Paul R.; Finney, Mark J.; Stukey, K. B.

1994-10-01

An optical sensor system extends gas temperature measurement capability in turbine engines beyond the present generation of thermocouple technology. The sensing element which consists of a thermally emissive insert embedded inside a sapphire lightguide is capable of operating above the melting point of nickel-based super alloys. The emissive insert generates an optical signal as a function of temperature. Continued development has led to an optically averaged system by combining the optical signals from four individual sensing elements at a single detector assembly. The size of the signal processor module has been reduced to overall dimensions of 2 X 4 X 0.7 inches. The durability of the optical probe design has been evaluated in an electric-utility operated gas turbine under the sponsorship of the Electric Power Research Institute. The temperature probe was installed between the first stage rotor and second stage nozzle on a General Electric MS7001B turbine. The combined length of the ceramic support tube and sensing element reached 1.5 inches into the hot gas stream. A total of over 2000 hours has been accumulated at probe operation temperatures near 1600 degree(s)F. An optically averaged sensor system was designed to replace the existing four thermocouple probes on the upper half of a GE F404 aircraft turbine engine. The system was ground tested for 250 hours as part of GE Aircraft Engines IR&D Optical Engine Program. Subsequently, two flight sensor systems were shipped for use on the FOCSI (Fiber Optic Control System Integration) Program. The optical harnesses, each with four optical probes, measure the exhaust gas temperature in a GE F404 engine.

Results of convective heating tests of a longitudinal gap on the Rockwell flat plate model (15-0, insert 7) in the NASA/Ames Research Center

NASA Technical Reports Server (NTRS)

Quan, M.; Lockman, W. K.

1975-01-01

Results are presented which were obtained from tests in a hypersonic wind tunnel to determine aerodynamic heating rates in a gap running parallel or slightly askew to the flow direction. The model used was a flat plate instrumented in thin-skin sections with chromelconstantan thermocouples. Heating rate profiles lengthwise along and down into the gap were obtained, and additional data were obtained from a total temperature probe and rake fabricated during the test to investigate an apparent aerodynamic cooling trend in the gap. Model variables were width, depth, length, and orientation of the gap relative to the flow direction. The tests were conducted at Mach 5.1 and Reynolds numbers per foot of 500,000, 1,000,000, and 2,000,000.

Tissue imaging using full field optical coherence microscopy with short multimode fiber probe

NASA Astrophysics Data System (ADS)

Sato, Manabu; Eto, Kai; Goto, Tetsuhiro; Kurotani, Reiko; Abe, Hiroyuki; Nishidate, Izumi

2018-03-01

In achieving minimally invasive accessibility to deeply located regions the size of the imaging probes is important. We demonstrated full-field optical coherence tomography (FF-OCM) using an ultrathin forward-imaging short multimode fiber (SMMF) probe of 50 μm core diameter, 125 μm diameter, and 7.4 mm length for optical communications. The axial resolution was measured to be 2.14 μm and the lateral resolution was also evaluated to be below 4.38 μm using a test pattern (TP). The spatial mode and polarization characteristics of SMMF were evaluated. Inserting SMMF to in vivo rat brain, 3D images were measured and 2D information of nerve fibers was obtained. The feasibility of an SMMF as an ultrathin forward-imaging probe in FF-OCM has been demonstrated.

Flexible needle with integrated optical coherence tomography probe for imaging during transbronchial tissue aspiration

NASA Astrophysics Data System (ADS)

Li, Jiawen; Quirk, Bryden C.; Noble, Peter B.; Kirk, Rodney W.; Sampson, David D.; McLaughlin, Robert A.

2017-10-01

Transbronchial needle aspiration (TBNA) of small lesions or lymph nodes in the lung may result in nondiagnostic tissue samples. We demonstrate the integration of an optical coherence tomography (OCT) probe into a 19-gauge flexible needle for lung tissue aspiration. This probe allows simultaneous visualization and aspiration of the tissue. By eliminating the need for insertion and withdrawal of a separate imaging probe, this integrated design minimizes the risk of dislodging the needle from the lesion prior to aspiration and may facilitate more accurate placement of the needle. Results from in situ imaging in a sheep lung show clear distinction between solid tissue and two typical constituents of nondiagnostic samples (adipose and lung parenchyma). Clinical translation of this OCT-guided aspiration needle holds promise for improving the diagnostic yield of TBNA.

Spacecraft Charging and the Microwave Anisotropy Probe Spacecraft

NASA Technical Reports Server (NTRS)

Timothy, VanSant J.; Neergaard, Linda F.

1998-01-01

The Microwave Anisotropy Probe (MAP), a MIDEX mission built in partnership between Princeton University and the NASA Goddard Space Flight Center (GSFC), will study the cosmic microwave background. It will be inserted into a highly elliptical earth orbit for several weeks and then use a lunar gravity assist to orbit around the second Lagrangian point (L2), 1.5 million kilometers, anti-sunward from the earth. The charging environment for the phasing loops and at L2 was evaluated. There is a limited set of data for L2; the GEOTAIL spacecraft measured relatively low spacecraft potentials (approx. 50 V maximum) near L2. The main area of concern for charging on the MAP spacecraft is the well-established threat posed by the "geosynchronous region" between 6-10 Re. The launch in the autumn of 2000 will coincide with the falling of the solar maximum, a period when the likelihood of a substorm is higher than usual. The likelihood of a substorm at that time has been roughly estimated to be on the order of 20% for a typical MAP mission profile. Because of the possibility of spacecraft charging, a requirement for conductive spacecraft surfaces was established early in the program. Subsequent NASCAP/GEO analyses for the MAP spacecraft demonstrated that a significant portion of the sunlit surface (solar cell cover glass and sunshade) could have nonconductive surfaces without significantly raising differential charging. The need for conductive materials on surfaces continually in eclipse has also been reinforced by NASCAP analyses.

Survey of microsatellite DNA in pine

Treesearch

C. S. Echt; P. May-Marquardt

1997-01-01

A large insert genomic library from eastern white pine (Pinus strobus) was probed for the microsatellite motifs (AC)n and (AG)n, all 10 trinucleotide motifs, and 22 of the 33 possible tetranucleotide motifs. For comparison with a species from a different subgenus, a loblolly pine (Pinus taeda...

Survey of microsatellite DNA in pine

Treesearch

Craig S. Echt; P. May-Marquardt

1997-01-01

A large insert genomic library from eastern white pine (Pinus strobus) was probed for the microsatellite motifs (AC)n and (AG)n, all 10 trinucleotide motifs, and 22 of the 33 possible tetranucleotide motifs. For comparison with a species from a different subgenus, a loblolly pine (Pinus taeda) genomic...

A simple, efficient resistance soldering apparatus

NASA Technical Reports Server (NTRS)

Vermillion, C. M.

1972-01-01

Multiple resistance soldering device for attaching electric leads to multiple terminal block connectors uses power source with one terminal connected to working probe, and other terminal attached to connector carrying common pins for lead insertion. Mating of male and female connectors solders each lead to individual cup pin.

Evaluation of the Use of Optical Fiber Thermometers for Thermal Control of the Quench Module Insert

NASA Technical Reports Server (NTRS)

Jones, Matthew R.; Farmer, Jeffrey T.; Breeding, Shawn P.

2001-01-01

Issues regarding the use of optical fiber thermometers to control heater settings in a microgravity vacuum furnace are addressed. It is desirable to use these probes in environments such as the International Space Station, because they can be operated without re-calibration for extended periods. However, the analysis presented in this paper shows that temperature readings obtained using optical fiber thermometers can be corrupted by emissions from the fiber when extended portions of the probe are exposed to elevated temperatures.

Evaluation of the Use of Optical Fiber Thermometers for Thermal Control of the Quench Module Insert

NASA Technical Reports Server (NTRS)

Jones, Matthew R.; Farmer, Jeffrey T.; Breeding, Shawn P.

1999-01-01

Issues regarding the use of optical fiber thermometers to control heater settings in a microgravity vacuum furnace are addressed. It is desirable to use these probes in environments such as the International Space Station, because they can be operated without re-calibration for extended periods. However, the analysis presented in this paper shows that temperature readings obtained using optical fiber thermometers are corrupted due to emissions from the fiber when extended portions of the probe are exposed to elevated temperatures.

Mobile Interspersed Repeats Are Major Structural Variants in the Human Genome

PubMed Central

Huang, Cheng Ran Lisa; Schneider, Anna M.; Lu, Yunqi; Niranjan, Tejasvi; Shen, Peilin; Robinson, Matoya A.; Steranka, Jared P.; Valle, David; Civin, Curt I.; Wang, Tao; Wheelan, Sarah J.; Ji, Hongkai; Boeke, Jef D.; Burns, Kathleen H.

2010-01-01

Summary Characterizing structural variants in the human genome is of great importance, but a genome wide analysis to detect interspersed repeats has not been done. Thus, the degree to which mobile DNAs contribute to genetic diversity, heritable disease, and oncogenesis remains speculative. We perform transposon insertion profiling by microarray (TIP-chip) to map human L1(Ta) retrotransposons (LINE-1 s) genome-wide. This identified numerous novel human L1(Ta) insertional polymorphisms with highly variant allelic frequencies. We also explored TIP-chip's usefulness to identify candidate alleles associated with different phenotypes in clinical cohorts. Our data suggest that the occurrence of new insertions is twice as high as previously estimated, and that these repeats are under-recognized as sources of human genomic and phenotypic diversity. We have just begun to probe the universe of human L1(Ta) polymorphisms, and as TIP-chip is applied to other insertions such as Alu SINEs, it will expand the catalog of genomic variants even further. PMID:20602999

Learning nursing procedures: the influence of simulator fidelity and student gender on teaching effectiveness.

PubMed

Grady, Janet L; Kehrer, Rosemary G; Trusty, Carole E; Entin, Eileen B; Entin, Elliot E; Brunye, Tad T

2008-09-01

Simulation technologies are gaining widespread acceptance across a variety of educational domains and applications. The current research examines whether basic nursing procedure training with high-fidelity versus low-fidelity mannequins results in differential skill acquisition and perceptions of simulator utility. Fifty-two first-year students were taught nasogastric tube and indwelling urinary catheter insertion in one of two ways. The first group learned nasogastric tube and urinary catheter insertion using high-fidelity and low-fidelity mannequins, respectively, and the second group learned nasogastric tube and urinary catheter insertion using low-fidelity and high-fidelity mannequins, respectively. The dependent measures included student performance on nasogastric tube and urinary catheter insertion testing, as measured by observer-based instruments, and self-report questionnaires probing student attitudes about the use of simulation in nursing education. Results demonstrated higher performance with high-fidelity than with low-fidelity mannequin training. In response to a self-report posttraining questionnaire, participants expressed a more positive attitude toward the high-fidelity mannequin, especially regarding its responsiveness and realism.

Plasma Perturbations in High-Speed Probing of Hall Thruster Discharge Chambers: Quantification and Mitigation

NASA Technical Reports Server (NTRS)

Jorns, Benjamin A.; Goebel, Dan M.; Hofer, Richard R.

2015-01-01

An experimental investigation is presented to quantify the effect of high-speed probing on the plasma parameters inside the discharge chamber of a 6-kW Hall thruster. Understanding the nature of these perturbations is of significant interest given the importance of accurate plasma measurements for characterizing thruster operation. An array of diagnostics including a high-speed camera and embedded wall probes is employed to examine in real time the changes in electron temperature and plasma potential induced by inserting a high-speed reciprocating Langmuir probe into the discharge chamber. It is found that the perturbations onset when the scanning probe is downstream of the electron temperature peak, and that along channel centerline, the perturbations are best characterized as a downstream shift of plasma parameters by 15-20% the length of the discharge chamber. A parametric study is performed to investigate techniques to mitigate the observed probe perturbations including varying probe speed, probe location, and operating conditions. It is found that the perturbations largely disappear when the thruster is operated at low power and low discharge voltage. The results of this mitigation study are discussed in the context of recommended methods for generating unperturbed measurements of the discharge chamber plasma.

Potential variations around grain boundaries in impurity-doped BaSi₂ epitaxial films evaluated by Kelvin probe force microscopy

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

Tsukahara, D.; Baba, M.; Honda, S.

2014-09-28

Potential variations around the grain boundaries (GBs) in antimony (Sb)-doped n-type and boron (B)-doped p-type BaSi₂ epitaxial films on Si(111) were evaluated by Kelvin probe force microscopy. Sb-doped n-BaSi₂ films exhibited positively charged GBs with a downward band bending at the GBs. The average barrier height for holes was approximately 10 meV for an electron concentration n ≈ 10¹⁷ cm⁻³. This downward band bending changed to upward band bending when n was increased to n = 1.8 × 10¹⁸cm⁻³. In the B-doped p-BaSi₂ films, the upward band bending was observed for a hole concentration p ≈ 10¹⁸cm⁻³. The average barriermore » height for electrons decreased from approximately 25 to 15 meV when p was increased from p = 2.7 × 10¹⁸ to p = 4.0 × 10¹⁸ cm⁻³. These results are explained under the assumption that the position of the Fermi level E{sub f} at GBs depends on the degree of occupancy of defect states at the GBs, while E{sub f} approached the bottom of the conduction band or the top of the valence band in the BaSi₂ grain interiors with increasing impurity concentrations. In both cases, such small barrier heights may not deteriorate the carrier transport properties. The electronic structures of impurity-doped BaSi₂ are also discussed using first-principles pseudopotential method to discuss the insertion sites of impurity atoms and clarify the reason for the observed n-type conduction in the Sb-doped BaSi₂ and p-type conduction in the B-doped BaSi₂.« less

Elastic and viscoelastic mechanical properties of brain tissues on the implanting trajectory of sub-thalamic nucleus stimulation.

PubMed

Li, Yan; Deng, Jianxin; Zhou, Jun; Li, Xueen

2016-11-01

Corresponding to pre-puncture and post-puncture insertion, elastic and viscoelastic mechanical properties of brain tissues on the implanting trajectory of sub-thalamic nucleus stimulation are investigated, respectively. Elastic mechanical properties in pre-puncture are investigated through pre-puncture needle insertion experiments using whole porcine brains. A linear polynomial and a second order polynomial are fitted to the average insertion force in pre-puncture. The Young's modulus in pre-puncture is calculated from the slope of the two fittings. Viscoelastic mechanical properties of brain tissues in post-puncture insertion are investigated through indentation stress relaxation tests for six interested regions along a planned trajectory. A linear viscoelastic model with a Prony series approximation is fitted to the average load trace of each region using Boltzmann hereditary integral. Shear relaxation moduli of each region are calculated using the parameters of the Prony series approximation. The results show that, in pre-puncture insertion, needle force almost increases linearly with needle displacement. Both fitting lines can perfectly fit the average insertion force. The Young's moduli calculated from the slope of the two fittings are worthy of trust to model linearly or nonlinearly instantaneous elastic responses of brain tissues, respectively. In post-puncture insertion, both region and time significantly affect the viscoelastic behaviors. Six tested regions can be classified into three categories in stiffness. Shear relaxation moduli decay dramatically in short time scales but equilibrium is never truly achieved. The regional and temporal viscoelastic mechanical properties in post-puncture insertion are valuable for guiding probe insertion into each region on the implanting trajectory.

Peptic Ulcers

MedlinePlus

... pylori . The endoscopy is sometimes used with a test called a pH probe in which a small wire is inserted into the lower part of the esophagus to measure the amount of acid going into that area. If there's any evidence of inflammation, the doctor will test for H. pylori . This test is important because ...

Heat Fluxes and Evaporation Measurements by Multi-Function Heat Pulse Probe: a Laboratory Experiment

NASA Astrophysics Data System (ADS)

Sharma, V.; Ciocca, F.; Hopmans, J. W.; Kamai, T.; Lunati, I.; Parlange, M. B.

2012-04-01

Multi Functional Heat Pulse Probes (MFHPP) are multi-needles probes developed in the last years able to measure temperature, thermal properties such as thermal diffusivity and volumetric heat capacity, from which soil moisture is directly retrieved, and electric conductivity (through a Wenner array). They allow the simultaneous measurement of coupled heat, water and solute transport in porous media, then. The use of only one instrument to estimate different quantities in the same volume and almost at the same time significantly reduces the need to interpolate different measurement types in space and time, increasing the ability to study the interdependencies characterizing the coupled transports, especially of water and heat, and water and solute. A three steps laboratory experiment is realized at EPFL to investigate the effectiveness and reliability of the MFHPP responses in a loamy soil from Conthey, Switzerland. In the first step specific calibration curves of volumetric heat capacity and thermal conductivity as function of known volumetric water content are obtained placing the MFHPP in small samplers filled with the soil homogeneously packed at different saturation degrees. The results are compared with literature values. In the second stage the ability of the MFHPP to measure heat fluxes is tested within a homemade thermally insulated calibration box and results are matched with those by two self-calibrating Heatflux plates (from Huxseflux), placed in the same box. In the last step the MFHPP are used to estimate the cumulative subsurface evaporation inside a small column (30 centimeters height per 8 centimeters inner diameter), placed on a scale, filled with the same loamy soil (homogeneously packed and then saturated) and equipped with a vertical array of four MFHPP inserted close to the surface. The subsurface evaporation is calculated from the difference between the net sensible heat and the net heat storage in the volume scanned by the probes, and the values obtained are matched with the overall evaporation, estimated through the scale in terms of weight loss. A numerical model able to solve the coupled heat-moisture diffusive equations is used to interpolate the obtained measures in the second and third step.

Validation of a Projection-domain Insertion of Liver Lesions into CT Images

PubMed Central

Chen, Baiyu; Ma, Chi; Leng, Shuai; Fidler, Jeff L.; Sheedy, Shannon P.; McCollough, Cynthia H.; Fletcher, Joel G.; Yu, Lifeng

2016-01-01

Rationale and Objectives The aim of this study was to validate a projection-domain lesion-insertion method with observer studies. Materials and Methods A total of 51 proven liver lesions were segmented from computed tomography images, forward projected, and inserted into patient projection data. The images containing inserted and real lesions were then reconstructed and examined in consensus by two radiologists. First, 102 lesions (51 original, 51 inserted) were viewed in a randomized, blinded fashion and scored from 1 (absolutely inserted) to 10 (absolutely real). Statistical tests were performed to compare the scores for inserted and real lesions. Subsequently, a two-alternative-forced-choice test was conducted, with lesions viewed in pairs (real vs. inserted) in a blinded fashion. The radiologists selected the inserted lesion and provided a confidence level of 1 (no confidence) to 5 (completely certain). The number of lesion pairs that were incorrectly classified was calculated. Results The scores for inserted and proven lesions had the same median (8) and similar interquartile ranges (inserted, 5.5–8; real, 6.5–8). The means scores were not significantly different between real and inserted lesions (P value = 0.17). The receiver operating characteristic curve was nearly diagonal, with an area under the curve of 0.58 ± 0.06. For the two-alternative-forced-choice study, the inserted lesions were incorrectly identified in 49% (25 out of 51) of pairs; radiologists were incorrect in 38% (3 out of 8) of pairs even when they felt very confident in identifying the inserted lesion (confidence level ≥4). Conclusions Radiologists could not distinguish between inserted and real lesions, thereby validating the lesion-insertion technique, which may be useful for conducting virtual clinical trials to optimize image quality and radiation dose. PMID:27432267

Endocavity Ultrasound Probe Manipulators

PubMed Central

Stoianovici, Dan; Kim, Chunwoo; Schäfer, Felix; Huang, Chien-Ming; Zuo, Yihe; Petrisor, Doru; Han, Misop

2014-01-01

We developed two similar structure manipulators for medical endocavity ultrasound probes with 3 and 4 degrees of freedom (DoF). These robots allow scanning with ultrasound for 3-D imaging and enable robot-assisted image-guided procedures. Both robots use remote center of motion kinematics, characteristic of medical robots. The 4-DoF robot provides unrestricted manipulation of the endocavity probe. With the 3-DoF robot the insertion motion of the probe must be adjusted manually, but the device is simpler and may also be used to manipulate external-body probes. The robots enabled a novel surgical approach of using intraoperative image-based navigation during robot-assisted laparoscopic prostatectomy (RALP), performed with concurrent use of two robotic systems (Tandem, T-RALP). Thus far, a clinical trial for evaluation of safety and feasibility has been performed successfully on 46 patients. This paper describes the architecture and design of the robots, the two prototypes, control features related to safety, preclinical experiments, and the T-RALP procedure. PMID:24795525

ERRATUM: In vivo evaluation of a neural stem cell-seeded prosthesis In vivo evaluation of a neural stem cell-seeded prosthesis

NASA Astrophysics Data System (ADS)

Purcell, E. K.; Seymour, J. P.; Yandamuri, S.; Kipke, D. R.

2009-08-01

In the published article, an error was made in figure 5. Specifically, the three-month, NSC-seeded image is a duplicate of the six-week image, and the one-day, probe alone image is a duplicate of the three-month image. The corrected figure is reproduced below. Figure 5 Figure 5. Glial encapsulation of each probe condition over the 3 month time course. Ox-42 labeled microglia and GFAP labeled astrocytes are shown. Images are taken from probes implanted in the same animal at each time point. NSC seeding was associated with reduced non-neuronal density at 1 day post-implantation in comparison to alginate coated probes and at the 1 week time point in comparison to untreated probes (P < 0.001). Glial activation is at its overall peak 1 week after insertion. A thin encapsulation layer surrounds probes at the 6 week and 3 month time points, with NSC-seeded probes having the greatest surrounding non-neuronal density P < 0.001). Interestingly, microglia appeared to have a ramified, or `surveilling', morphology surrounding a neural stem cell-alginate probe initially, whereas activated cells with an amoeboid structure were found near an alginate probe in the same hemisphere of one animal (left panels).

Initial laboratory experience with a novel ultrasound probe for standard and single-port robotic kidney surgery: increasing console surgeon autonomy and minimizing instrument clashing.

PubMed

Yakoubi, Rachid; Autorino, Riccardo; Laydner, Humberto; Guillotreau, Julien; White, Michael A; Hillyer, Shahab; Spana, Gregory; Khanna, Rakesh; Isaac, Wahib; Haber, Georges-Pascal; Stein, Robert J; Kaouk, Jihad H

2012-06-01

The aim of this study was to evaluate a novel ultrasound probe specifically developed for robotic surgery by determining its efficiency in identifying renal tumors. The study was carried out using the Da Vinci™ surgical system in one female pig. Renal tumor targets were created by percutaneous injection of a tumor mimic mixture. Single-port and standard robotic partial nephrectomy were performed. Intraoperative ultrasound was performed using both standard laparoscopic probe and the new ProART™ Robotic probe. Probe maneuverability and ease of handling for tumor localization were recorded. The standard laparoscopic probe was guided by the assistant. Significant clashing with robotic arms was noted during the single-port procedure. The novel robotic probe was easily introduced through the assistant trocar, and held by the console surgeon using the robotic Prograsp™ with no registered clashing in the external operative field. The average time for grasping the new robotic probe was less than 10 s. Once inserted and grasped, no limitation was found in terms of instrument clashing during the single-port procedure. This novel ultrasound probe developed for robotic surgery was noted to be user-friendly when performing porcine standard and especially single-port robotic partial nephrectomy. Copyright © 2011 John Wiley & Sons, Ltd.

Miniature standoff Raman probe for neurosurgical applications

NASA Astrophysics Data System (ADS)

Stevens, Oliver A. C.; Hutchings, Joanne; Gray, William; Vincent, Rosa Louise; Day, John C.

2016-08-01

Removal of intrinsic brain tumors is a delicate process, where a high degree of specificity is required to remove all of the tumor tissue without damaging healthy brain. The accuracy of this process can be greatly enhanced by intraoperative guidance. Optical biopsies using Raman spectroscopy are a minimally invasive and lower-cost alternative to current guidance methods. A miniature Raman probe for performing optical biopsies of human brain tissue is presented. The probe allows sampling inside a conventional stereotactic brain biopsy system: a needle of length 200 mm and inner diameter of 1.8 mm. By employing a miniature stand-off Raman design, the probe removes the need for any additional components to be inserted into the brain. Additionally, the probe achieves a very low internal silica background while maintaining good collection of Raman signal. To illustrate this, the probe is compared with a Raman probe that uses a pair of optical fibers for collection. The miniature stand-off Raman probe is shown to collect a comparable number of Raman scattered photons, but the Raman signal to background ratio is improved by a factor of five at Raman shifts below ˜500 cm-1. The probe's suitability for use on tissue is demonstrated by discriminating between different types of healthy porcine brain tissue.

Lambda Probe Measurements of Laboratory Spheromaks

NASA Astrophysics Data System (ADS)

Jorne, E.; Bellan, P. M.; Hsu, S. C.; Moynihan, C.

2003-10-01

A combined current and magnetic probe (lambda probe) has been constructed and is being tested for the purpose of investigating the behavior of spheromaks formed by the Caltech planar spheromak gun. The probe consists of a 1.5cm diameter, 52 turn Rogowski coil and a single loop magnetic coil, housed in a ceramic shell attached to a 95cm long hollow, steel shaft. A high voltage power supply was used to test the probe's ability to measure pulsed currents with submicrosecond rise times. A calibrated current pulse was provided by a 1μF capacitor discharged by a krytron switch to a low inductance circuit. Magnetic calibration was obtained by using the capacitor bank to power a 16cm diameter Helmholtz coil. Both magnetic and current calibration were in good agreement with estimates based on geometry. An existing steel shaft will be replaced by a ceramic shaft in order to minimize undesired effects on the plasma by a conductor. Once sealed with epoxy, the probe will be ready for insertion into the vacuum chamber and used to measure the magnetic field and parallel current during spheromak formation.

Optimizing the specificity of nucleic acid hybridization.

PubMed

Zhang, David Yu; Chen, Sherry Xi; Yin, Peng

2012-01-22

The specific hybridization of complementary sequences is an essential property of nucleic acids, enabling diverse biological and biotechnological reactions and functions. However, the specificity of nucleic acid hybridization is compromised for long strands, except near the melting temperature. Here, we analytically derived the thermodynamic properties of a hybridization probe that would enable near-optimal single-base discrimination and perform robustly across diverse temperature, salt and concentration conditions. We rationally designed 'toehold exchange' probes that approximate these properties, and comprehensively tested them against five different DNA targets and 55 spurious analogues with energetically representative single-base changes (replacements, deletions and insertions). These probes produced discrimination factors between 3 and 100+ (median, 26). Without retuning, our probes function robustly from 10 °C to 37 °C, from 1 mM Mg(2+) to 47 mM Mg(2+), and with nucleic acid concentrations from 1 nM to 5 µM. Experiments with RNA also showed effective single-base change discrimination.

Molecular imaging needles: dual-modality optical coherence tomography and fluorescence imaging of labeled antibodies deep in tissue

PubMed Central

Scolaro, Loretta; Lorenser, Dirk; Madore, Wendy-Julie; Kirk, Rodney W.; Kramer, Anne S.; Yeoh, George C.; Godbout, Nicolas; Sampson, David D.; Boudoux, Caroline; McLaughlin, Robert A.

2015-01-01

Molecular imaging using optical techniques provides insight into disease at the cellular level. In this paper, we report on a novel dual-modality probe capable of performing molecular imaging by combining simultaneous three-dimensional optical coherence tomography (OCT) and two-dimensional fluorescence imaging in a hypodermic needle. The probe, referred to as a molecular imaging (MI) needle, may be inserted tens of millimeters into tissue. The MI needle utilizes double-clad fiber to carry both imaging modalities, and is interfaced to a 1310-nm OCT system and a fluorescence imaging subsystem using an asymmetrical double-clad fiber coupler customized to achieve high fluorescence collection efficiency. We present, to the best of our knowledge, the first dual-modality OCT and fluorescence needle probe with sufficient sensitivity to image fluorescently labeled antibodies. Such probes enable high-resolution molecular imaging deep within tissue. PMID:26137379

Communication: hybrid femtosecond/picosecond rotational coherent anti-Stokes Raman scattering thermometry using a narrowband time-asymmetric probe pulse.

PubMed

Stauffer, Hans U; Miller, Joseph D; Roy, Sukesh; Gord, James R; Meyer, Terrence R

2012-03-21

A narrowband, time-asymmetric probe pulse is introduced into the hybrid femtosecond/picosecond rotational coherent anti-Stokes Raman scattering (fs/ps RCARS) technique to provide accurate and precise single-shot, high-repetition-rate gas-phase thermometric measurements. This narrowband pulse-generated by inserting a Fabry-Pérot étalon into the probe-pulse beam path-enables frequency-domain detection of pure-rotational transitions. The unique time-asymmetric nature of this pulse, in turn, allows for detection of resonant Raman-active rotational transitions free of signal contamination by nonresonant four-wave-mixing processes while still allowing detection at short probe-pulse delays, where collisional dephasing processes are negligible. We demonstrate that this approach provides excellent single-shot thermometric accuracy (<1% error) and precision (~2.5%) in gas-phase environments. © 2012 American Institute of Physics

Neural Interfaces for Intracortical Recording: Requirements, Fabrication Methods, and Characteristics.

PubMed

Szostak, Katarzyna M; Grand, Laszlo; Constandinou, Timothy G

2017-01-01

Implantable neural interfaces for central nervous system research have been designed with wire, polymer, or micromachining technologies over the past 70 years. Research on biocompatible materials, ideal probe shapes, and insertion methods has resulted in building more and more capable neural interfaces. Although the trend is promising, the long-term reliability of such devices has not yet met the required criteria for chronic human application. The performance of neural interfaces in chronic settings often degrades due to foreign body response to the implant that is initiated by the surgical procedure, and related to the probe structure, and material properties used in fabricating the neural interface. In this review, we identify the key requirements for neural interfaces for intracortical recording, describe the three different types of probes-microwire, micromachined, and polymer-based probes; their materials, fabrication methods, and discuss their characteristics and related challenges.

cDNA cloning and analysis of RNA 2 of a Prunus stem pitting isolate of tomato ringspot virus.

PubMed

Hadidi, A; Powell, C A

1991-10-01

Recombinant plasmids containing sequences derived from the genome of a tomato ringspot virus (TomRSV) isolate associated with both stem pitting disease of stone fruits and apple union necrosis and decline were constructed. Selected inserts were subcloned into the polylinker region of the SP6 transcription vector pSP64. Using the SP6 promoter flanking this region, high specific activity 32P-labelled cRNA probes were generated by SP6 RNA polymerase. cRNA probes were specific for TomRSV RNA 2 present in purified virions or in extracts from woody and herbacous hosts. No sequence relatedness was detected between TomRSV RNA 2 and genomic RNA from tobacco ringspot, arabis mosaic, strawberry latent ringspot, or cucumber mosaic virus in Northern blot analysis using TomRSV cRNA probes. These probes detected TomRSV infection in woody and herbaceous hosts in dot-blot hybridization assays.

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

Nakayama, T.; Kubo, O.; Shingaya, Y.

the research of advanced materials based on nanoscience and nanotechnology, it is often desirable to measure nanoscale local electrical conductivity at a designated position of a given sample. For this purpose, multiple-probe scanning probe microscopes (MP-SPMs), in which two, three or four scanning tunneling microscope (STM) or atomic force microscope (AFM) probes are operated independently, have been developed. Each probe in an MP-SPM is used not only for observing high-resolution STM or AFM images but also for forming an electrical contact enabling nanoscale local electrical conductivity measurement. The world's first double-probe STM (DP-STM) developed by the authors, which was subsequentlymore » modified to a triple-probe STM (TP-STM), has been used to measure the conductivities of one-dimensional metal nanowires and carbon nanotubes and also two-dimensional molecular films. A quadruple-probe STM (QP-STM) has also been developed and used to measure the conductivity of two-dimensional molecular films without the ambiguity of contact resistance between the probe and sample. Moreover, a quadruple-probe AFM (QP-AFM) with four conductive tuning-fork-type self-detection force sensing probes has been developed to measure the conductivity of a nanostructure on an insulating substrate. A general-purpose computer software to control four probes at the same time has also been developed and used in the operation of the QP-AFM. These developments and applications of MP-SPMs are reviewed in this paper.« less

Fast and reliable method of conductive carbon nanotube-probe fabrication for scanning probe microscopy

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

Dremov, Vyacheslav, E-mail: dremov@issp.ac.ru; Fedorov, Pavel; Grebenko, Artem

2015-05-15

We demonstrate the procedure of scanning probe microscopy (SPM) conductive probe fabrication with a single multi-walled carbon nanotube (MWNT) on a silicon cantilever pyramid. The nanotube bundle reliably attached to the metal-covered pyramid is formed using dielectrophoresis technique from the MWNT suspension. It is shown that the dimpled aluminum sample can be used both for shortening/modification of the nanotube bundle by applying pulse voltage between the probe and the sample and for controlling the probe shape via atomic force microscopy imaging the sample. Carbon nanotube attached to cantilever covered with noble metal is suitable for SPM imaging in such modulationmore » regimes as capacitance contrast microscopy, Kelvin probe microscopy, and scanning gate microscopy. The majority of such probes are conductive with conductivity not degrading within hours of SPM imaging.« less

Microdialysis of glucose in subcutaneous adipose tissue up to 3 weeks in healthy volunteers.

PubMed

Wientjes, K J; Vonk, P; Vonk-van Klei, Y; Schoonen, A J; Kossen, N W

1998-09-01

To measure possible changes in dialysate glucose concentrations over time, to validate the diffusional model for glucose transport from tissue to the probe, and to evaluate the actual glucose concentration in adipose tissue. Glucose concentrations in the subcutaneous adipose tissue of five healthy subjects (age 25 +/- 2.7 years, BMI 23.2 +/- 2.3 kg/m2 [mean +/- SD]) were measured by the microdialysis technique and compared with blood glucose. We applied microdialysis probes with hollow fibers of various membrane length (10-35 mm), used eight perfusion flow rates (0.5-20 microl/min), and perfused four glucose solutions (0.0, 2.8, 8.3, 11.1 mmol/l). After implantation, a substantial decrease in glucose recovery to the lowest value of 26 +/- 10% of the final plateau value was noted during the first few hours (n = 4). Recovery increased and stabilized after 5-9 days at 84.0 +/- 7.4% of capillary blood glucose when a flow rate of 0.5 microl/min was applied. According to the zero net-flux method, the glucose concentration in equilibrium, Cequi, with the surrounding tissue can be obtained. This concentration also decreases; however, 1 h after recovery, Cequi increases again over 1 or 2 days to a stable value that is not significantly different from the measured capillary blood glucose (P < 0.05). Using various perfusion flow rates and probes (membrane length 10-35 mm), it is shown that diffusion is the rate-limiting process for glucose transport through tissue. Insertion of the microdialysis probes causes damage to the adipose cells and the vascular bed around the probe. Glucose recovery decreases because of a lower blood supply. In 5-9 days, glucose recovery increases; apparently, this time is needed to repair the microstructure of tissue around the probe. After stabilization of the recovery, no loss of probe permeability, which is due to biocompatibility problems, was seen. The change during the 2 days in equilibrium concentration is probably caused by an inflammation reaction that consumes glucose around the probe. The individual increase in recovery during the 1st days after probe insertion until a stable plateau value is reached (flow rate >0 microl/min) is complicated for short-term clinical glucose measurements in adipose tissue. After stabilization, the mean equilibrium concentration of all subjects was equal to the mean capillary blood glucose concentration. Therefore, we conclude that capillary blood glucose concentration probably is the driving force for diffusion through the capillary wall into the probe and is not some interstitial concentration.

Intraluminal pneumatic lithotripsy for the removal of encrusted urinary catheters.

PubMed

Canby-Hagino, E D; Caballero, R D; Harmon, W J

1999-12-01

Urologists frequently treat patients requiring long-term urinary drainage with a percutaneous nephrostomy tube or ureteral stent. When such tubes are neglected and become encrusted, removal challenges even experienced urologists. We describe a new, minimally invasive technique for safely and rapidly removing encrusted, occluded tubes using the Swiss Lithoclast pneumatic lithotriptor. Patients presenting with an encrusted urinary catheter were evaluated by excretory urography for renal function and obstruction. Gentle manual extraction of the tube was attempted, followed by traditional extracorporeal shock wave lithotripsy and/or ureteroscopy. When the tube was not extracted, patients were then treated with intraluminal insertion of a pneumatic lithotripsy probe. One patient presented with an encrusted, occluded nephrostomy tube and 2 had an encrusted, occluded, indwelling ureteral stent. None was removed by manual traction. Intraluminal encrustations prevented the pigtail portions of these tubes from uncoiling and removal. In each case a pneumatic lithotripsy probe was inserted into the lumen of the catheter and advanced in a jackhammer-like fashion. This technique resulted in disruption of the intraluminal encrustations and straightening of the tubes so that they were removed in an atraumatic manner. Intraluminal pneumatic lithotripsy is a safe, easy and rapid technique for removing encrusted urinary catheters. It is unique in that the pneumatic lithotripsy probe functions in an aqueous and nonaqueous environment, and dislodges intraluminal calcifications. We recommend its use as first line treatment for removing encrusted urinary catheters.

Detection of restriction fragment length polymorphisms in clinical isolates and serially passaged Pseudomonas aeruginosa strains.

PubMed Central

Hjelm, L N; Branstrom, A A; Warren, R L

1990-01-01

An 800-base-pair HindIII-PstI fragment that flanks a hot spot for Tn7 insertion was isolated from the chromosome of Pseudomonas aeruginosa and cloned into pUC12. The fragment was used to probe XhoI digests of genomic DNA from 18 P. aeruginosa isolates collected from sputum samples of seven cystic fibrosis patients. Only two XhoI restriction fragment length polymorphisms (RFLPs), of 3.7 and 7.7 kilobases (kb), were detected. Isolate WSU3531-1 (3.7-kb XhoI fragment) and WSU3860 (7.7-kb XhoI fragment), while isolated from the same patient, showed different RFLPs. Serial passages of isolate WSU3531-1 demonstrated that this strain was phenotypically stable. In contrast, colony and pigment variants were readily isolated at a frequency of 1% from serial passages of isolate WSU3860. When XhoI-digested genomic DNA from phenotypic variants of serially passaged WSU3860 were probed with the 800-base-pair HindIII-PstI fragment, the probe hybridized to a 10.4-kb XhoI fragment from three isolates. Restriction analysis of the genomic DNA digested with a variety of restriction enzymes showed that a 2.7-kb insertion occurred in the same region for all three isolates. There appeared to be no correlation between changes in the RFLP and changes in colony morphology. Images PMID:1977762

A low molecular weight artificial RNA of unique size with multiple probe target regions

NASA Technical Reports Server (NTRS)

Pitulle, C.; Dsouza, L.; Fox, G. E.

1997-01-01

Artificial RNAs (aRNAs) containing novel sequence segments embedded in a deletion mutant of Vibrio proteolyticus 5S rRNA have previously been shown to be expressed from a plasmid borne growth rate regulated promoter in E. coli. These aRNAs accumulate to high levels and their detection is a promising tool for studies in molecular microbial ecology and in environmental monitoring. Herein a new construct is described which illustrates the versatility of detection that is possible with aRNAs. This 3xPen aRNA construct carries a 72 nucleotide insert with three copies of a unique 17 base probe target sequence. This aRNA is 160 nucleotides in length and again accumulates to high levels in the E. coli cytoplasm without incorporating into ribosomes. The 3xPen aRNA illustrates two improvements in detection. First, by appropriate selection of insert size, we obtained an aRNA which provides a unique and hence, easily quantifiable peak, on a high resolution gel profile of low molecular weight RNAs. Second, the existence of multiple probe targets results in a nearly commensurate increase in signal when detection is by hybridization. These aRNAs are naturally amplified and carry sequence segments that are not found in known rRNA sequences. It thus may be possible to detect them directly. An experimental step involving RT-PCR or PCR amplification of the gene could therefore be avoided.

Aeroshell Design Techniques for Aerocapture Entry Vehicles

NASA Technical Reports Server (NTRS)

Dyke, R. Eric; Hrinda, Glenn A.

2004-01-01

A major goal of NASA s In-Space Propulsion Program is to shorten trip times for scientific planetary missions. To meet this challenge arrival speeds will increase, requiring significant braking for orbit insertion, and thus increased deceleration propellant mass that may exceed launch lift capabilities. A technology called aerocapture has been developed to expand the mission potential of exploratory probes destined for planets with suitable atmospheres. Aerocapture inserts a probe into planetary orbit via a single pass through the atmosphere using the probe s aeroshell drag to reduce velocity. The benefit of an aerocapture maneuver is a large reduction in propellant mass that may result in smaller, less costly missions and reduced mission cruise times. The methodology used to design rigid aerocapture aeroshells will be presented with an emphasis on a new systems tool under development. Current methods for fast, efficient evaluations of structural systems for exploratory vehicles to planets and moons within our solar system have been under development within NASA having limited success. Many systems tools that have been attempted applied structural mass estimation techniques based on historical data and curve fitting techniques that are difficult and cumbersome to apply to new vehicle concepts and missions. The resulting vehicle aeroshell mass may be incorrectly estimated or have high margins included to account for uncertainty. This new tool will reduce the guesswork previously found in conceptual aeroshell mass estimations.

NMR measurement system including two synchronized ring buffers, with 128 rf coils for in situ water monitoring in a polymer electrolyte fuel cell

NASA Astrophysics Data System (ADS)

Ogawa, Kuniyasu; Haishi, Tomoyuki; Aoki, Masaru; Hasegawa, Hiroshi; Morisaka, Shinichi; Hashimoto, Seitaro

2017-01-01

A small radio-frequency (rf) coil inserted into a polymer electrolyte fuel cell (PEFC) can be used to acquire nuclear magnetic resonance (NMR) signals from the water in a membrane electrode assembly (MEA) or in oxygen gas channels in the PEFC. Measuring the spatial distribution of the water in a large PEFC requires using many rf probes, so an NMR measurement system which acquires NMR signals from 128 rf probes at intervals of 0.5 s was manufactured. The system has eight rf transceiver units with a field-programmable gate array (FPGA) for modulation of the excitation pulse and quadrature phase detection of the NMR signal, and one control unit with two ring buffers for data control. The sequence data required for the NMR measurement were written into one ring buffer. The acquired NMR signal data were then written temporarily into the other ring buffer and then were transmitted to a personal computer (PC). A total of 98 rf probes were inserted into the PEFC that had an electrical generation area of 16 cm × 14 cm, and the water generated in the PEFC was measured when the PEFC operated at 100 A. As a result, time-dependent changes in the spatial distribution of the water content in the MEA and the water in the oxygen gas channels were obtained.

Method for producing labeled single-stranded nucleic acid probes

DOEpatents

Dunn, John J.; Quesada, Mark A.; Randesi, Matthew

1999-10-19

Disclosed is a method for the introduction of unidirectional deletions in a cloned DNA segment. More specifically, the method comprises providing a recombinant DNA construct comprising a DNA segment of interest inserted in a cloning vector, the cloning vector having an f1 endonuclease recognition sequence adjacent to the insertion site of the DNA segment of interest. The recombinant DNA construct is then contacted with the protein pII encoded by gene II of phage f1 thereby generating a single-stranded nick. The nicked DNA is then contacted with E. coli Exonuclease III thereby expanding the single-stranded nick into a single-stranded gap. The single-stranded gapped DNA is then contacted with a single-strand-specific endonuclease thereby producing a linearized DNA molecule containing a double-stranded deletion corresponding in size to the single-stranded gap. The DNA treated in this manner is then incubated with DNA ligase under conditions appropriate for ligation. Also disclosed is a method for producing single-stranded DNA probes. In this embodiment, single-stranded gapped DNA, produced as described above, is contacted with a DNA polymerase in the presence of labeled nucleotides to fill in the gap. This DNA is then linearized by digestion with a restriction enzyme which cuts outside the DNA segment of interest. The product of this digestion is then denatured to produce a labeled single-stranded nucleic acid probe.

A semi-automated vascular access system for preclinical models

NASA Astrophysics Data System (ADS)

Berry-Pusey, B. N.; Chang, Y. C.; Prince, S. W.; Chu, K.; David, J.; Taschereau, R.; Silverman, R. W.; Williams, D.; Ladno, W.; Stout, D.; Tsao, T. C.; Chatziioannou, A.

2013-08-01

Murine models are used extensively in biological and translational research. For many of these studies it is necessary to access the vasculature for the injection of biologically active agents. Among the possible methods for accessing the mouse vasculature, tail vein injections are a routine but critical step for many experimental protocols. To perform successful tail vein injections, a high skill set and experience is required, leaving most scientists ill-suited to perform this task. This can lead to a high variability between injections, which can impact experimental results. To allow more scientists to perform tail vein injections and to decrease the variability between injections, a vascular access system (VAS) that semi-automatically inserts a needle into the tail vein of a mouse was developed. The VAS uses near infrared light, image processing techniques, computer controlled motors, and a pressure feedback system to insert the needle and to validate its proper placement within the vein. The VAS was tested by injecting a commonly used radiolabeled probe (FDG) into the tail veins of five mice. These mice were then imaged using micro-positron emission tomography to measure the percentage of the injected probe remaining in the tail. These studies showed that, on average, the VAS leaves 3.4% of the injected probe in the tail. With these preliminary results, the VAS system demonstrates the potential for improving the accuracy of tail vein injections in mice.

The effect of augmented reality training on percutaneous needle placement in spinal facet joint injections.

PubMed

Yeo, Caitlin T; Ungi, Tamas; U-Thainual, Paweena; Lasso, Andras; McGraw, Robert C; Fichtinger, Gabor

2011-07-01

The purpose of this study was to determine if augmented reality image overlay and laser guidance systems can assist medical trainees in learning the correct placement of a needle for percutaneous facet joint injection. The Perk Station training suite was used to conduct and record the needle insertion procedures. A total of 40 volunteers were randomized into two groups of 20. 1) The Overlay group received a training session that consisted of four insertions with image and laser guidance, followed by two insertions with laser overlay only. 2) The Control group received a training session of six classical freehand insertions. Both groups then conducted two freehand insertions. The movement of the needle was tracked during the series of insertions. The final insertion procedure was assessed to determine if there was a benefit to the overlay method compared to the freehand insertions. The Overlay group had a better success rate (83.3% versus 68.4%, p=0.002), and potential for less tissue damage as measured by the amount of needle movement inside the phantom (3077.6 mm(2) versus 5607.9 mm(2) , p =0.01). These results suggest that an augmented reality overlay guidance system can assist medical trainees in acquiring technical competence in a percutaneous needle insertion procedure. © 2011 IEEE

Experimental field study of problem-solving using tools in free-ranging capuchins (Sapajus nigritus, formerly Cebus nigritus).

PubMed

Garber, P A; Gomes, D F; Bicca-Marques, J C

2012-04-01

Some populations of capuchins are reported to use tools to solve foraging problems in the wild. In most cases, this involves the act of pounding and digging. The use of probing tools by wild capuchins is considerably less common. Here we report on the results of an experimental field study conducted in southern Brazil designed to examine the ability of wild black-horned capuchins (Sapajus nigritus) to use a wooden dowel as a lever or a probe to obtain an embedded food reward. A group of eight capuchins was presented with two experimental platforms, each housing a clear Plexiglas box containing two bananas on a shelf and four inserted dowels. Depending on the conditions of the experiment, the capuchins were required either to pull (Condition I) or push (Conditions II and III) the dowels, in order to dislodge the food reward from the shelf so that it could be manually retrieved. In Condition I, four individuals spontaneously solved the foraging problem by pulling the dowels in 25% (72/291) of visits. In Conditions II and III, however, no capuchin successfully pushed the dowels forward to obtain the food reward. During these latter two experimental conditions, the capuchins continued to pull the dowels (41/151 or 27% of visits), even though this behavior did not result in foraging success. The results of these field experiments are consistent with an identical study conducted on wild Cebus capucinus in Costa Rica, and suggest that when using an external object as a probe to solve a foraging problem, individual capuchins were able to rapidly learn an association between the tool and the food reward, but failed to understand exactly how the tool functioned in accomplishing the task. The results also suggest that once a capuchin learned to solve this tool-mediated foraging problem, the individual persisted in using the same solution even in the face of repeated failure (slow rate of learning extinction). © 2011 Wiley Periodicals, Inc.

Interface thermal conductance characterization by infrared thermography: A tool for the study of insertions in bronze ancient Statuary

NASA Astrophysics Data System (ADS)

Mercuri, F.; Caruso, G.; Orazi, N.; Zammit, U.; Cicero, C.; Colacicchi Alessandri, O.; Ferretti, M.; Paoloni, S.

2018-05-01

In this paper, a new method based on the use of infrared thermography is proposed for the characterization of repairs and inserted parts on ancient bronzes. In particular, the quality of the contact between different kind of insertions and the main body of bronze statues is investigated by analysing the heat conduction process occurring across the interface between them. The thermographic results have been used to establish the nature of these inserted elements and the way they have been coupled to the main body of the statue during and after the manufacturing process. A model for the heat conduction based on the numerical finite elements method has been applied to compare the obtained results to the theoretical predictions. Measurements have been first carried out on test samples and then in the field on the Boxer at Rest (Museo Nazionale Romano in Rome), a masterpiece of the Greek Statuary, which contains a large variety of inserted items and repairs which are typical of the manufacturing process of bronze artefacts in general.

49 CFR Appendix E to Part 227 - Use of Insert Earphones for Audiometric Testing

Code of Federal Regulations, 2010 CFR

2010-10-01

... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OCCUPATIONAL NOISE EXPOSURE Pt. 227, App. E Appendix.... B. Technicians who conduct audiometric tests must be trained to insert the earphones correctly into... audiometer. IV. Background Noise Levels Testing shall be conducted in a room where the background ambient...

EXPERIMENTAL EVALUATION OF GEOMETRICAL SHAPE FACTORS FOR SHORT CYLINDRICAL PROBES USED TO MEASURE SOIL PERMEABILITY TO AIR

EPA Science Inventory

Permeability of soil has become recognized as an important parameter in determining the rate of transport and entry of radon from the soil into indoor environments. This parameter is usually measured in the field by inserting a cylindrical tube with a short porous section into th...

Automatic cryogenic liquid level controller is safe for use near combustible substances

NASA Technical Reports Server (NTRS)

Krejsa, M.

1966-01-01

Automatic mechanical liquid level controller that is independent of any external power sources is used with safety in the presence of combustibles. A gas filled capillary tube which leads from a pressurized chamber, is inserted into the cryogenic liquid reservoir and becomes a liquid level sensing element or probe.

7 CFR 201.40 - Bulk.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Sampling in the Administration of the Act § 201.40 Bulk. Bulk seeds or screenings shall be sampled by inserting a long probe or thrusting the hand into the bulk as circumstances require in at least seven... 7 Agriculture 3 2011-01-01 2011-01-01 false Bulk. 201.40 Section 201.40 Agriculture Regulations of...

7 CFR 201.40 - Bulk.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Sampling in the Administration of the Act § 201.40 Bulk. Bulk seeds or screenings shall be sampled by inserting a long probe or thrusting the hand into the bulk as circumstances require in at least seven... 7 Agriculture 3 2010-01-01 2010-01-01 false Bulk. 201.40 Section 201.40 Agriculture Regulations of...

In Vivo Validation of Custom-Designed Silicon-Based Microelectrode Arrays for Long-Term Neural Recording and Stimulation

PubMed Central

Manoonkitiwongsa, Panya S.; Wang, Cindy X.; McCreery, Douglas B.

2012-01-01

We developed and validated silicon-based neural probes for neural stimulating and recording in long-term implantation in the brain. The probes combine the deep reactive ion etching process and mechanical shaping of their tip region, yielding a mechanically sturdy shank with a sharpened tip to reduce insertion force into the brain and spinal cord, particularly, with multiple shanks in the same array. The arrays’ insertion forces have been quantified in vitro. Five consecutive chronically-implanted devices were fully functional from 3 to 18 months. The microelectrode sites were electroplated with iridium oxide, and the charge injection capacity measurements were performed both in vitro and after implantation in the adult feline brain. The functionality of the chronic array was validated by stimulating in the cochlear nucleus and recording the evoked neuronal activity in the central nucleus of the inferior colliculus. The arrays’ recording quality has also been quantified in vivo with neuronal spike activity recorded up to 566 days after implantation. Histopathology evaluation of neurons and astrocytes using immunohistochemical stains indicated minimal alterations of tissue architecture after chronic implantation. PMID:22020666

Automatic insertion of simulated microcalcification clusters in a software breast phantom

NASA Astrophysics Data System (ADS)

Shankla, Varsha; Pokrajac, David D.; Weinstein, Susan P.; DeLeo, Michael; Tuite, Catherine; Roth, Robyn; Conant, Emily F.; Maidment, Andrew D.; Bakic, Predrag R.

2014-03-01

An automated method has been developed to insert realistic clusters of simulated microcalcifications (MCs) into computer models of breast anatomy. This algorithm has been developed as part of a virtual clinical trial (VCT) software pipeline, which includes the simulation of breast anatomy, mechanical compression, image acquisition, image processing, display and interpretation. An automated insertion method has value in VCTs involving large numbers of images. The insertion method was designed to support various insertion placement strategies, governed by probability distribution functions (pdf). The pdf can be predicated on histological or biological models of tumor growth, or estimated from the locations of actual calcification clusters. To validate the automated insertion method, a 2-AFC observer study was designed to compare two placement strategies, undirected and directed. The undirected strategy could place a MC cluster anywhere within the phantom volume. The directed strategy placed MC clusters within fibroglandular tissue on the assumption that calcifications originate from epithelial breast tissue. Three radiologists were asked to select between two simulated phantom images, one from each placement strategy. Furthermore, questions were posed to probe the rationale behind the observer's selection. The radiologists found the resulting cluster placement to be realistic in 92% of cases, validating the automated insertion method. There was a significant preference for the cluster to be positioned on a background of adipose or mixed adipose/fibroglandular tissues. Based upon these results, this automated lesion placement method will be included in our VCT simulation pipeline.

High-Throughput Analysis of T-DNA Location and Structure Using Sequence Capture.

PubMed

Inagaki, Soichi; Henry, Isabelle M; Lieberman, Meric C; Comai, Luca

2015-01-01

Agrobacterium-mediated transformation of plants with T-DNA is used both to introduce transgenes and for mutagenesis. Conventional approaches used to identify the genomic location and the structure of the inserted T-DNA are laborious and high-throughput methods using next-generation sequencing are being developed to address these problems. Here, we present a cost-effective approach that uses sequence capture targeted to the T-DNA borders to select genomic DNA fragments containing T-DNA-genome junctions, followed by Illumina sequencing to determine the location and junction structure of T-DNA insertions. Multiple probes can be mixed so that transgenic lines transformed with different T-DNA types can be processed simultaneously, using a simple, index-based pooling approach. We also developed a simple bioinformatic tool to find sequence read pairs that span the junction between the genome and T-DNA or any foreign DNA. We analyzed 29 transgenic lines of Arabidopsis thaliana, each containing inserts from 4 different T-DNA vectors. We determined the location of T-DNA insertions in 22 lines, 4 of which carried multiple insertion sites. Additionally, our analysis uncovered a high frequency of unconventional and complex T-DNA insertions, highlighting the needs for high-throughput methods for T-DNA localization and structural characterization. Transgene insertion events have to be fully characterized prior to use as commercial products. Our method greatly facilitates the first step of this characterization of transgenic plants by providing an efficient screen for the selection of promising lines.

Differential and directional effects of perfusion on electrical and thermal conductivities in liver.

PubMed

Podhajsky, Ronald J; Yi, Ming; Mahajan, Roop L

2009-01-01

Two different measurement probes--an electrical probe and a thermal conductivity probe--were designed, fabricated, calibrated, and used in experimental studies on a pig liver model that was designed to control perfusion rates. These probes were fabricated by photolithography and mounted in 1.5-mm diameter catheters. We measured the local impedance and thermal conductivity, respectively, of the artificially perfused liver at different flow rates and, by rotating the probes, in different directions. The results show that both the local electrical conductivity and the thermal conductivity varied location to location, that thermal conductivity increased with decreased distance to large blood vessels, and that significant directional differences exist in both electrical and thermal conductivities. Measurements at different perfusion rates demonstrated that both the local electrical and local thermal conductivities increased linearly with the square root of perfusion rate. These correlations may be of great value to many energy-based biomedical applications.

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

Tran, Ich C.; Tunuguntla, Ramya H.; Kim, Kyunghoon

Carbon nanotube porins (CNTPs), small segments of carbon nanotubes capable of forming defined pores in lipid membranes, are important future components for bionanoelectronic devices as they could provide a robust analog of biological membrane channels. Furthermore, in order to control the incorporation of these CNT channels into lipid bilayers, it is important to understand the structure of the CNTPs before and after insertion into the lipid bilayer as well as the impact of such insertion on the bilayer structure. Here we employed a noninvasive in situ probe, small-angle X-ray scattering, to study the integration of CNT porins into dioleoylphosphatidylcholine bilayers.more » These results show that CNTPs in solution are stabilized by a monolayer of lipid molecules wrapped around their outer surface. We also demonstrate that insertion of CNTPs into the lipid bilayer results in decreased bilayer thickness with the magnitude of this effect increasing with the concentration of CNTPs.« less

Phosphine-alkene ligands as mechanistic probes in the Pauson-Khand reaction.

PubMed

Ferrer, Catalina; Benet-Buchholz, Jordi; Riera, Antoni; Verdaguer, Xavier

2010-07-26

An alkyne tetracarbonyl dicobalt complex with a chelated phosphine-alkene ligand, in which the phosphorus atom and the alkene from the ligand are attached to the same cobalt atom has been prepared, isolated, and characterized by X-ray crystallography. The complex serves as a mechanistic model for an intermediate of the Pauson-Khand (PK) reaction. Although the alkene fragment is located in an equatorial coordination site with an appropriate orientation, and, therefore, should undergo insertion, it failed to give the PK product upon either thermal or N-methylmorpholine N-oxide activation. However, a phosphine-alkene complex that contains a terminal alkene readily provided the corresponding PK product. We attribute this change in reactivity to the different ability of each olefin to undergo 1,2-insertion. These results provide further insights into the factors that govern a crucial step in the PK reaction, the olefin insertion.

Influence of the Thermal Conductivity of Thermally Conductive Plastics on the Thermal Distribution of an Light-Emitting Diode Headlight for Vehicles.

PubMed

Lee, Dong Kyu; Lee, Jae Min; Cho, Moon Uk; Park, Hyun Jung; Cha, Yu-Jung; Kim, Hyeong Jin; Kwak, Joon Seop

2018-09-01

This paper investigates the thermal distribution of an LED headlight for vehicles based on the thermal conductivity of thermally conductive plastics (TCP). In general, heat dissipation structures used for LED headlights are made from metallic materials. However, headlight structures made from TCP have not been investigated. The headlights made from TCP having a various thermal conductivity were fabricated by injection molding with and without a metal plate insert. The temperature characteristics were compared and analyzed using thermal simulations and measurement. The inserted metal in TCP greatly reduced the temperature at solder point, indicating that the fast heat dissipation from the high power LED package to TCP though the inserted metal is essential. The measured temperature at solder points decreased as the thermal conductivity of TCP increased, which is well matched to the simulation results. The measured temperature at the solder point was lower than 150 °C when the thermal conductivity of the TCP was 10 W/mK.

Characterizing the performance of an affordable, multichannel conductivity probe for density measurements in stratified flows

NASA Astrophysics Data System (ADS)

Subramanian, Balaji; Carminati, Marco; Luzzatto-Fegiz, Paolo

2017-11-01

In stratified flows, conductivity (combined with temperature) is often used to measure density. The conductivity probes typically used can resolve very fine spatial scales, but on the downside they are fragile, expensive, sensitive to environmental noise and have only single channel capability. Recently a low-cost, robust, arduino-based probe called Conduino was developed, which can be valuable in a wide range of applications where resolving extremely small spatial scales is not needed. This probe uses micro-USB connectors as actual conductivity sensors with a custom designed electronic board for simultaneous acquisition from multiple probes, with conductivity resolution comparable to commercially available PME conductivity probe. A detailed assessment of performance of this Conduino probe is described here. To establish time response and sensitivity as a function of electrode geometry, we build a variety of shapes for different kinds of applications, with tip spacing ranging from 0.5-2.5 mm, and with electrode length ranging from 2.3-6 mm. We set up a two-layer density profile and traverse it rapidly, yielding a time response comparable to PME. The Conduino's multi-channel capability is used to operate probe arrays, which helps to construct density fields in stratified flows.

Development of Genetic Markers in Eucalyptus Species by Target Enrichment and Exome Sequencing

PubMed Central

Dasgupta, Modhumita Ghosh; Dharanishanthi, Veeramuthu; Agarwal, Ishangi; Krutovsky, Konstantin V.

2015-01-01

The advent of next-generation sequencing has facilitated large-scale discovery, validation and assessment of genetic markers for high density genotyping. The present study was undertaken to identify markers in genes supposedly related to wood property traits in three Eucalyptus species. Ninety four genes involved in xylogenesis were selected for hybridization probe based nuclear genomic DNA target enrichment and exome sequencing. Genomic DNA was isolated from the leaf tissues and used for on-array probe hybridization followed by Illumina sequencing. The raw sequence reads were trimmed and high-quality reads were mapped to the E. grandis reference sequence and the presence of single nucleotide variants (SNVs) and insertions/ deletions (InDels) were identified across the three species. The average read coverage was 216X and a total of 2294 SNVs and 479 InDels were discovered in E. camaldulensis, 2383 SNVs and 518 InDels in E. tereticornis, and 1228 SNVs and 409 InDels in E. grandis. Additionally, SNV calling and InDel detection were conducted in pair-wise comparisons of E. tereticornis vs. E. grandis, E. camaldulensis vs. E. tereticornis and E. camaldulensis vs. E. grandis. This study presents an efficient and high throughput method on development of genetic markers for family– based QTL and association analysis in Eucalyptus. PMID:25602379

Application of porous metal enrichment probe sampling to single cell analysis using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS).

PubMed

Fu, Qiang; Tang, Jun; Cui, Meng; Xing, Junpeng; Liu, Zhiqiang; Liu, Shuying

2016-01-01

There is an increasing need for analyzing metabolism in a single cell, which is important to understand the nature of cellular heterogeneity, disease, growth and specialization, etc. However, single cell analysis is often challenging for the traces of samples. In the present study, porous metal enrichment probe sampling combined with matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) has been applied for in situ analysis of live onion epidemic cell. Porous probe, treated by corroding copper wire with HCl, was directly inserted into a single cell to get cell solution. A self-made linear actuator was enough to control the penetration of probe into the target cell accurately. Then samples on the tip of probe were eluted and detected by a commercial MALDI-TOF-MS directly. The formation of porous microstructure on the probe surface increased the adsorptive capacity of cell solution. The sensitivity of porous probe sampling was 6 times higher than uncorroded probes generally. This method provides a sensitive and convenient way for the sampling and detection of single cell solution. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A strip-shield improves the efficiency of a solenoid coil in probes for high-field solid-state NMR of lossy biological samples.

PubMed

Wu, Chin H; Grant, Christopher V; Cook, Gabriel A; Park, Sang Ho; Opella, Stanley J

2009-09-01

A strip-shield inserted between a high inductance double-tuned solenoid coil and the glass tube containing the sample improves the efficiency of probes used for high-field solid-state NMR experiments on lossy aqueous samples of proteins and other biopolymers. A strip-shield is a coil liner consisting of thin copper strips layered on a PTFE (polytetrafluoroethylene) insulator. With lossy samples, the shift in tuning frequency is smaller, the reduction in Q, and RF-induced heating are all significantly reduced when the strip-shield is present. The performance of 800MHz (1)H/(15)N and (1)H/(13)C double-resonance probes is demonstrated on aqueous samples of membrane proteins in phospholipid bilayers.

Electron density measurements in STPX plasmas

NASA Astrophysics Data System (ADS)

Clark, Jerry; Williams, R.; Titus, J. B.; Mezonlin, E. D.; Akpovo, C.; Thomas, E.

2017-10-01

Diagnostics have been installed to measure the electron density of Spheromak Turbulent Physics Experiment (STPX) plasmas at Florida A. & M. University. An insertable probe, provided by Auburn University, consisting of a combination of a triple-tipped Langmuir probe and a radial array consisting of three ion saturation current / floating potential rings has been installed to measure instantaneous plasma density, temperature and plasma potential. As the ramp-up of the experimental program commences, initial electron density measurements from the triple-probe show that the electron density is on the order of 1019 particles/m3. For a passive measurement, a CO2 interferometer system has been designed and installed for measuring line-averaged densities and to corroborate the Langmuir measurements. We describe the design, calibration, and performance of these diagnostic systems on large volume STPX plasmas.

UW Imaging of Seismic-Physical-Models in Air Using Fiber-Optic Fabry-Perot Interferometer.

PubMed

Rong, Qiangzhou; Hao, Yongxin; Zhou, Ruixiang; Yin, Xunli; Shao, Zhihua; Liang, Lei; Qiao, Xueguang

2017-02-17

A fiber-optic Fabry-Perot interferometer (FPI) has been proposed and demonstrated for the ultrasound wave (UW) imaging of seismic-physical models. The sensor probe comprises a single mode fiber (SMF) that is inserted into a ceramic tube terminated by an ultra-thin gold film. The probe performs with an excellent UW sensitivity thanks to the nanolayer gold film, and thus is capable of detecting a weak UW in air medium. Furthermore, the compact sensor is a symmetrical structure so that it presents a good directionality in the UW detection. The spectral band-side filter technique is used for UW interrogation. After scanning the models using the sensing probe in air, the two-dimensional (2D) images of four physical models are reconstructed.

Fuel leak detection apparatus for gas cooled nuclear reactors

DOEpatents

Burnette, Richard D.

1977-01-01

Apparatus is disclosed for detecting nuclear fuel leaks within nuclear power system reactors, such as high temperature gas cooled reactors. The apparatus includes a probe assembly that is inserted into the high temperature reactor coolant gaseous stream. The probe has an aperture adapted to communicate gaseous fluid between its inside and outside surfaces and also contains an inner tube for sampling gaseous fluid present near the aperture. A high pressure supply of noncontaminated gas is provided to selectively balance the pressure of the stream being sampled to prevent gas from entering the probe through the aperture. The apparatus includes valves that are operable to cause various directional flows and pressures, which valves are located outside of the reactor walls to permit maintenance work and the like to be performed without shutting down the reactor.

Conformational Dynamics inside Amino-Terminal Disease Hotspot of Ryanodine Receptor

PubMed Central

Zhong, Xiaowei; Liu, Ying; Zhu, Li; Meng, Xing; Wang, Ruiwu; Van Petegem, Filip; Wagenknecht, Terence; Wayne Chen, S. R.; Liu, Zheng

2013-01-01

Summary The N-terminal region of both skeletal and cardiac ryanodine receptor is a disease mutation hotspot. Recently, a crystal structure of the RyR1 fragment (residues 1-559) was solved. This N-terminal structure contains three separate domains, A, B, and C, and was docked into a central vestibule in a full-length RyR1 cryo-EM map. Here we reconstructed 3D cryo-EM structures of two GFP-tagged RyR2s with GFP inserted after residue Glu-310 and Ser-437, respectively. The structures of RyR2E310-GFP and RyR2S437-GFP displayed an extra mass on domain B and C, directly validating the predicted docking model. Next, we revealed domain movements in molecular dynamics flexible fitting models in both the closed and open state cryo-EM maps. To further probe the conformational changes, we generated FRET pairs by inserting CFP or YFP in two selected domains, FRET studies of three dual-insertion pairs and three co-expressed single-insertion pairs showed the dynamic structural changes within the N-terminal domains. PMID:24139989

The role of probe oxide in local surface conductivity measurements

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

Barnett, C. J.; Kryvchenkova, O.; Wilson, L. S. J.

2015-05-07

Local probe methods can be used to measure nanoscale surface conductivity, but some techniques including nanoscale four point probe rely on at least two of the probes forming the same low resistivity non-rectifying contact to the sample. Here, the role of probe shank oxide has been examined by carrying out contact and non-contact I V measurements on GaAs when the probe oxide has been controllably reduced, both experimentally and in simulation. In contact, the barrier height is pinned but the barrier shape changes with probe shank oxide dimensions. In non-contact measurements, the oxide modifies the electrostatic interaction inducing a quantummore » dot that alters the tunneling behavior. For both, the contact resistance change is dependent on polarity, which violates the assumption required for four point probe to remove probe contact resistance from the measured conductivity. This has implications for all nanoscale surface probe measurements and macroscopic four point probe, both in air and vacuum, where the role of probe oxide contamination is not well understood.« less

LOCATION AND CHARACTERIZATION OF SUBSURFACE ANOMALIES USING A SOIL CONDUCTIVITY PROBE

EPA Science Inventory

An electrical conductivity probe, designed for use with "direct push" technology, has been successfully used to locate buried drums, contaminant plumes, and to precisely locate and characterize a previously installed permeable reactive iron wall. The conductivity probe was desig...

Analysis of non-contact and contact probe-to-sample thermal exchange for quantitative measurements of thin film and nanostructure thermal conductivity by the scanning hot probe method

NASA Astrophysics Data System (ADS)

Wilson, Adam A.

The ability to measure thermal properties of thin films and nanostructured materials is an important aspect of many fields of academic study. A strategy especially well-suited for nanoscale investigations of these properties is the scanning hot probe technique, which is unique in its ability to non-destructively interrogate the thermal properties with high resolution, both laterally as well as through the thickness of the material. Strategies to quantitatively determine sample thermal conductivity depend on probe calibration. State of the art calibration strategies assume that the area of thermal exchange between probe and sample does not vary with sample thermal conductivity. However, little investigation has gone into determining whether or not that assumption is valid. This dissertation provides a rigorous study into the probe-to-sample heat transfer through the air gap at diffusive distances for a variety of values of sample thermal conductivity. It is demonstrated that the thermal exchange radius and gap/contact thermal resistance varies with sample thermal conductivity as well as tip-to-sample clearance in non-contact mode. In contact mode, it is demonstrated that higher thermal conductivity samples lead to a reduction in thermal exchange radius for Wollaston probe tips. Conversely, in non-contact mode and in contact mode for sharper probe tips where air contributes the most to probe-to-sample heat transfer, the opposite trend occurs. This may be attributed to the relatively strong solid-to-solid conduction occurring between probe and sample for the Wollaston probes. A three-dimensional finite element (3DFE) model was developed to investigate how the calibrated thermal exchange parameters vary with sample thermal conductivity when calibrating the probe via the intersection method in non-contact mode at diffusive distances. The 3DFE model was then used to explore the limits of sensitivity of the experiment for a range of simulated experimental conditions. It is determined that, when operating the scanning hot probe technique in air at standard temperature and pressure using Wollaston probes, the technique is capable of measuring, within 20% uncertainty, samples with values of thermal conductivity up to 10 Wm-1K-1 in contact mode and up to 2 Wm-1K-1 in non-contact mode. By increasing the thermal conductivity of the probe's surroundings (i.e. changing air to a more conductive gas), sensitivity in non-contact mode to sample thermal conductivity is improved, which suggests potential for future investigations using non-contact scanning hot probe to measure thermal conductivity of higher thermal conductivity samples. The ability of the technique to differentiate thin films from the substrate is investigated, and the sensitivity of the technique to thin films and samples with anisotropic properties is explored. The models (both analytical and finite element) developed and reported in this dissertation lead to the ability to measure samples which, by the standard procedure before this work, were unable to be accurately measured. While other techniques failed to be able to successfully interrogate the film thermal conductivity of a full set of double-wall carbon nanotubes infused into polymers, the methods developed in this work allowed non-contact scanning hot probe measurements to be successfully performed to obtain the film thermal conductivity for each sample. Finite element simulations accounting for the anisotropy of these thin film on sample materials show similar trends with independently measured in-plane thermal conductivity for the only two (of five) samples in the set which were successfully able to be measured by the independent technique. Investigations in contact mode with high resolution Pd probes, whose probe-to-sample clearance is difficult to control in a repeatable fashion, show that surface roughness affects the thermal contact resistance. This can lead to values of reported sample thermal conductivity which are misleading, when using the standard calibrated thermal exchange parameters on samples with significantly different surface roughness than the calibration samples. This affect was taken into account to report sample thermal conductivity of Bi2Te3 nanoflakes.

Left ventricular, systemic arterial, and baroreflex responses to ketamine and TEE in chronically instrumented monkeys

NASA Technical Reports Server (NTRS)

Koenig, S. C.; Ludwig, D. A.; Reister, C.; Fanton, J. W.; Ewert, D.; Convertino, V. A.

2001-01-01

Effects of prescribed doses of ketamine five minutes after application and influences of transesophageal echocardiography (TEE) on left ventricular, systemic arterial, and baroreflex responses were investigated to test the hypothesis that ketamine and/or TEE probe insertion alter cardiovascular function. Seven rhesus monkeys were tested under each of four randomly selected experimental conditions: (1) intravenous bolus dose of ketamine (0.5 ml), (2) continuous infusion of ketamine (500 mg/kg/min), (3) continuous infusion of ketamine (500 mg/kg/min) with TEE, and (4) control (no ketamine or TEE). Monkeys were chronically instrumented with a high fidelity, dual-sensor micromanometer to measure left ventricular and aortic pressure and a transit-time ultrasound probe to measure aortic flow. These measures were used to calculate left ventricular function. A 4-element Windkessel lumped-parameter model was used to estimate total peripheral resistance and systemic arterial compliance. Baroreflex response was calculated as the change in R-R interval divided by the change in mean aortic pressure measured during administration of graded concentrations of nitroprusside. The results indicated that five minutes after ketamine application heart rate and left ventricular diastolic compliance decreased while TEE increased aortic systolic and diastolic pressure. We conclude that ketamine may be administered as either a bolus or continuous infusion without affecting cardiovascular function 5 minutes after application while the insertion of a TEE probe will increase aortic pressure. The results for both ketamine and TEE illustrate the classic "Hawthorne Effect," where the observed values are partly a function of the measurement process. Measures of aortic pressure, heart rate, and left ventricular diastolic pressure should be viewed as relative, as opposed to absolute, when organisms are sedated with ketamine or instrumented with a TEE probe.

Preliminary results from a simulated laboratory experiment or an encounter of cluster satellite probes with a reconnection layer

NASA Astrophysics Data System (ADS)

Yamada, M.; Ren, Y.; Ji, H.; Gerhardt, S.; Darfman, S.

2006-12-01

With the recent upgrade of the MRX (Magnetic Reconnection Experiment) device[1], our experimental operation allows us to carry out a jog experiment in which a current sheet can be moved swiftly across an inserted probe assembly. A cluster of probes with variable distances can be inserted into a known desired position in the MRX device. This setup can be similar to the situation in which a cluster of satellites encounters a rapidly moving reconnection layer. If necessary, we can create a neutral sheet where the density of one side is significantly higher than the other, as is the case for the magnetopause. A variable guide field will be applied to study its effect on reconnection. We proposed[2] to document basic patterns of data during a simulated encounter of the MRX reconnection layer with the four-probe mock-up system and compare them with data acquired from past satellites. Relative position of the MMS satellites in the magnetosphere can then be determined. Optimum cluster configuration or distance between the four satellites can be determined for various diagnostics or research missions. The relationship of magnetic fluctuations[3] with the observed out-of- plane quadrupole field, a characteristic signature of the Hall MHD, can be also studied in this series of experiments. In this paper, results from a preliminary experiment will be presented. These experiments utilize effectively the unique MRX ability to accurately know the location of diagnostics with respect to the moving reconnection layer. Supported by DoE, NASA, NSF. [1] M. Yamada et al, Phys. Plasmas 13, 052119 (2006), [2] M.Yamada et al, MMS-IDS proposal (2006), [3] H. Ji et al, Phys. Rev. Letts. 92, 115001 (2004)

Deep high-resolution fluorescence microscopy of full organs: the benefit of ultraminiature confocal miniprobes

NASA Astrophysics Data System (ADS)

Schwarz, France; Le Nevez, Arnaud; Genet, Magalie; Osdoit, Anne; Lacombe, François

2009-02-01

Background: Confocal Laser Endomicroscopy (CLE) based on ultraminiature miniprobes (Cellvizio®, Mauna Kea Technologies, Paris, France) is able to image the inner microstructure of retroperitoneal full organs punctured during EUS-FNA procedures, such as pancreas, liver or lymph nodes. Therefore, pCLE can provide an easy-to-use and precise adjunct tool to ultrasonographic interventions in order to target suspicious areas for biopsies in EUS-FNA. Material and Methods: Probe-based CLE (pCLE) was performed on ex-vivo surgically resected specimens after topical application of fluorophores in standard 19G and 22G needles. Two prototype miniprobes ("S-probe" 300 microns diameter, field of view 400*280 microns, and "S-probe" 650 microns diameter, field of view 500*600 microns) were then inserted into the needles and enabled visualization of the inner microstructures of uterus, lung, kidney, stomach and esophagus, in both healthy and cancerous conditions. Then, pCLE was performed in-vivo on four pigs during three NOTES and one EUS-FNA procedures after intravenous injection of 2-7mL fluorescein 1-10% using the prototype "S-probe" 350 microns diameter inserted in 19G FNA needles. Liver, pancreas and spleen were imaged. Results: During the ex-vivo experiments, pCLE made it possible to distinguish microstructures, such as alveoli and macrophages in the lungs. During the in-vivo experiments, Cellvizio® video sequences showed hepatic lobules and the portal vein in the liver, and red and white pulp in the spleen. Conclusion: pCLE provides in vivo cellular information about full organs. It has the potential to help target biopsies during EUSFNA, which suffers from a high rate of false negatives, thus increasing its sensitivity.

Inspecting Friction Stir Welding using Electromagnetic Probes

NASA Technical Reports Server (NTRS)

Kinchen, David G.

2004-01-01

A report describes the use of advanced electromagnetic probes to measure the dimensions, the spatial distribution of electrical conductivity, and related other properties of friction stir welds (FSWs) between parts made of the same or different aluminum alloy(s). The probes are of the type described in in another Tech Brief. To recapitulate: A probe of this type is essentially an eddy-current probe that includes a primary (driver) winding that meanders and multiple secondary (sensing) windings that meander along the primary winding. Electrical conductivity is commonly used as a measure of heat treatment and tempering of aluminum alloys, but prior to the development of these probes, the inadequate sensitivity and limited accuracy of electrical-conductivity probes precluded such use on FSWs between different aluminum alloys, and the resolution of those probes was inadequate for measurement of FSW dimensions with positions and metallurgical properties. In contrast, the present probes afford adequate accuracy and spatial resolution for the purposes of measuring the dimensions of FSW welds and correlating spatially varying electrical conductivities with metallurgical properties, including surface defects.

Noncontact Measurement Of Critical Current In Superconductor

NASA Technical Reports Server (NTRS)

Israelsson, Ulf E.; Strayer, Donald M.

1992-01-01

Critical current measured indirectly via flux-compression technique. Magnetic flux compressed into gap between superconductive hollow cylinder and superconductive rod when rod inserted in hole in cylinder. Hall-effect probe measures flux density before and after compression. Method does not involve any electrical contact with superconductor. Therefore, does not cause resistive heating and consequent premature loss of superconductivity.

2'-Bispyrene-modified 2'-O-methyl RNA probes as useful tools for the detection of RNA: synthesis, fluorescent properties, and duplex stability.

PubMed

Krasheninina, Olga A; Novopashina, Darya S; Lomzov, Alexander A; Venyaminova, Alya G

2014-09-05

The synthesis and properties two series of new 2'-O-methyl RNA probes, each containing a single insertion of a 2'-bispyrenylmethylphosphorodiamidate derivative of a nucleotide (U, C, A, and G), are described. As demonstrated by UV melting studies, the probes form stable complexes with model RNAs and DNAs. Significant increases (up to 21-fold) in pyrene excimer fluorescence intensity were observed upon binding of most of the probes with complementary RNAs, but not with DNAs. The fluorescence spectra are independent of the nature of the modified nucleotides. The nucleotides on the 5'-side of the modified nucleotide have no effect on the fluorescence spectra, whereas the natures of the two nucleotides on the 3'-side are important: CC, CG, and UC dinucleotide units on the 3'-side of the modified nucleotide provide the maximum increases in excimer fluorescence intensity. This study suggests that these 2'-bispyrene-labeled 2'-O-methyl RNA probes might be useful tools for detection of RNAs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quartz crystal microbalance (QCM) affinity biosensor for genetically modified organisms (GMOs) detection.

PubMed

Mannelli, Ilaria; Minunni, Maria; Tombelli, Sara; Mascini, Marco

2003-03-01

A DNA piezoelectric sensor has been developed for the detection of genetically modified organisms (GMOs). Single stranded DNA (ssDNA) probes were immobilised on the sensor surface of a quartz crystal microbalance (QCM) device and the hybridisation between the immobilised probe and the target complementary sequence in solution was monitored. The probe sequences were internal to the sequence of the 35S promoter (P) and Nos terminator (T), which are inserted sequences in the genome of GMOs regulating the transgene expression. Two different probe immobilisation procedures were applied: (a) a thiol-dextran procedure and (b) a thiol-derivatised probe and blocking thiol procedure. The system has been optimised using synthetic oligonucleotides, which were then applied to samples of plasmidic and genomic DNA isolated from the pBI121 plasmid, certified reference materials (CRM), and real samples amplified by the polymerase chain reaction (PCR). The analytical parameters of the sensor have been investigated (sensitivity, reproducibility, lifetime etc.). The results obtained showed that both immobilisation procedures enabled sensitive and specific detection of GMOs, providing a useful tool for screening analysis in food samples.

Method and apparatus for determining the physical properties of materials using dynamic light scattering techniques

NASA Technical Reports Server (NTRS)

Dhadwal, Harbans S. (Inventor)

1992-01-01

A system for determining the physical properties of materials through the use of dynamic light scattering is disclosed. The system includes a probe, a laser source for directing a laser beam into the probe, and a photodetector for converting scattered light detected by the probe into electrical signals. The probe includes at least one optical fiber connected to the laser source and a second optical fiber connected to the photodetector. Each of the fibers may adjoin a gradient index microlens which is capable of providing a collimated laser beam into a scattering medium. The position of the second optical fiber with respect to the optical axis of the probe determines whether homodyne or self-beating detection is provided. Self-beating detection may be provided without a gradient index microlens. This allows a very small probe to be constructed which is insertable through a hypodermic needle or the like into a droplet extending from such a needle. A method of detecting scattered light through the use of a collimated, Gaussian laser beam is also provided. A method for controlling the waist and divergence of the optical field emanating from the free end of an optical fiber is also provided.

Towards molecular electronics with large-area molecular junctions.

PubMed

Akkerman, Hylke B; Blom, Paul W M; de Leeuw, Dago M; de Boer, Bert

2006-05-04

Electronic transport through single molecules has been studied extensively by academic and industrial research groups. Discrete tunnel junctions, or molecular diodes, have been reported using scanning probes, break junctions, metallic crossbars and nanopores. For technological applications, molecular tunnel junctions must be reliable, stable and reproducible. The conductance per molecule, however, typically varies by many orders of magnitude. Self-assembled monolayers (SAMs) may offer a promising route to the fabrication of reliable devices, and charge transport through SAMs of alkanethiols within nanopores is well understood, with non-resonant tunnelling dominating the transport mechanism. Unfortunately, electrical shorts in SAMs are often formed upon vapour deposition of the top electrode, which limits the diameter of the nanopore diodes to about 45 nm. Here we demonstrate a method to manufacture molecular junctions with diameters up to 100 microm with high yields (> 95 per cent). The junctions show excellent stability and reproducibility, and the conductance per unit area is similar to that obtained for benchmark nanopore diodes. Our technique involves processing the molecular junctions in the holes of a lithographically patterned photoresist, and then inserting a conducting polymer interlayer between the SAM and the metal top electrode. This simple approach is potentially low-cost and could pave the way for practical molecular electronics.

Determination of Surface-Exposed, Functional Domains of Gonococcal Transferrin-Binding Protein A

PubMed Central

Yost-Daljev, Mary Kate; Cornelissen, Cynthia Nau

2004-01-01

The gonococcal transferrin receptor is composed of two distinct proteins, TbpA and TbpB. TbpA is a member of the TonB-dependent family of integral outer membrane transporters, while TbpB is lipid modified and thought to be peripherally surface exposed. We previously proposed a hypothetical topology model for gonococcal TbpA that was based upon computer predictions and similarity with other TonB-dependent transporters for which crystal structures have been determined. In the present study, the hemagglutinin epitope was inserted into TbpA to probe the surface topology of this protein and secondarily to test the functional impacts of site-specific mutagenesis. Twelve epitope insertion mutants were constructed, five of which allowed us to confirm the surface exposure of loops 2, 3, 5, 7, and 10. In contrast to the predictions set forth by the hypothetical model, insertion into the plug region resulted in an epitope that was surface accessible, while epitope insertions into two putative loops (9 and 11) were not surface accessible. Insertions into putative loop 3 and β strand 9 abolished transferrin binding and utilization, and the plug insertion mutant exhibited decreased transferrin-binding affinity concomitant with an inability to utilize it. Insertion into putative β strand 16 generated a mutant that was able to bind transferrin normally but that was unable to mediate utilization. Mutants with insertions into putative loops 2, 9, and 11 maintained wild-type binding affinity but could utilize only transferrin in the presence of TbpB. This is the first demonstration of the ability of TbpB to compensate for a mutation in TbpA. PMID:14977987

Discrepancy between culture and DNA probe analysis for the detection of periodontal bacteria.

PubMed

van Steenbergen, T J; Timmerman, M F; Mikx, F H; de Quincey, G; van der Weijden, G A; van der Velden, U; de Graaff, J

1996-10-01

The purpose of this study was to compare a commercially available DNA probe technique with conventional cultural techniques for the detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in subgingival plaque samples. Samples from 20 patients with moderate to severe periodontitis were evaluated at baseline and during a 15 months period of periodontal treatment. Paperpoints from 4 periodontal pockets per patient were forwarded to Omnigene for DNA probe analysis, and simultaneously inserted paperpoints from the same pockets were analyzed by standard culture techniques. In addition, mixed bacterial samples were constructed harbouring known proportions of 25 strains of A. actinomycetemcomitans, P. gingivalis and P. intermedia each. A relatively low concordance was found between both methods. At baseline a higher detection frequency was found for A. actinomycetemcomitans and P. gingivalis for the DNA probe technique; for P. intermedia the detection frequency by culture was higher. For A. actinomycetemcomitans, 21% of the culture positive samples was positive with the DNA probe. Testing the constructed bacterial samples with the DNA probe method resulted in about 16% false positive results for the 3 species tested. Furthermore, 40% of P. gingivalis strains were not detected by the DNA probe. The present data suggest that at least part of the discrepancies found between the DNA probe technique used and cultural methods are caused by false positive and false negative DNA probe results. Therefore, the value of this DNA probe method for the detection of periodontal pathogens is questionable.

[Application of acupoint anatomy localization method with colorful tube in education of acupoint anatomy].

PubMed

Song, Shi-Lin

2013-04-01

To seek a precise and simple method for localization of acupoint in anatomical experiment teaching. Medical bone needles were inserted into acupoints. Then, self-mode copper probe needles were thrust along the center of the bone needles to open the inner structures of acuppoints. And probe needles were replaced by colored plastic tubes. Finally, bone needles were withdrawn so as to fix the plastic tubes into the acupoints to facilitate the later cutting. This method for acupoint anatomic positioning is of low cost with accurate positioning and simple manipulation, which has advantages in strong experimental and innovative values.

Tube cutter tool and method of use for coupon removal

DOEpatents

Nachbar, H.D.; Etten, M.P. Jr.; Kurowski, P.A.

1997-05-06

A tube cutter tool is insertable into a tube for cutting a coupon from a damaged site on the exterior of the tube. Prior to using the tool, the damaged site is first located from the interior of the tube using a multi-coil pancake eddy current test probe. The damaged site is then marked. A fiber optic probe is used to monitor the subsequent cutting procedure which is performed using a hole saw mounted on the tube cutter tool. Prior to completion of the cutting procedure, a drill in the center of the hole saw is drilled into the coupon to hold it in place. 4 figs.

Tube cutter tool and method of use for coupon removal

DOEpatents

Nachbar, Henry D.; Etten, Jr., Marvin P.; Kurowski, Paul A.

1997-01-01

A tube cutter tool is insertable into a tube for cutting a coupon from a damaged site on the exterior of the tube. Prior to using the tool, the damaged site is first located from the interior of the tube using a multi-coil pancake eddy current test probe. The damaged site is then marked. A fiber optic probe is used to monitor the subsequent cutting procedure which is performed using a hole saw mounted on the tube cutter tool. Prior to completion of the cutting procedure, a drill in the center of the hole saw is drilled into the coupon to hold it in place.

Galileo Jupiter approach orbit determination

NASA Technical Reports Server (NTRS)

Miller, J. K.; Nicholson, F. T.

1984-01-01

Orbit determination characteristics of the Jupiter approach phase of the Galileo mission are described. Predicted orbit determination performance is given for the various mission events that occur during Jupiter approach. These mission events include delivery of an atmospheric entry probe, acquisition of probe science data by the Galileo orbiter for relay to earth, delivery of an orbiter to a close encounter of the Galilean satellite Io, and insertion of the orbiter into orbit about Jupiter. The orbit determination strategy and resulting accuracies are discussed for the data types which include Doppler, range, optical imaging of Io, and a new Very Long Baseline Interferometry (VLBI) data type called Differential One-Way Range (DOR).

High-throughput analysis of T-DNA location and structure using sequence capture

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

Inagaki, Soichi; Henry, Isabelle M.; Lieberman, Meric C.

Agrobacterium-mediated transformation of plants with T-DNA is used both to introduce transgenes and for mutagenesis. Conventional approaches used to identify the genomic location and the structure of the inserted T-DNA are laborious and high-throughput methods using next-generation sequencing are being developed to address these problems. Here, we present a cost-effective approach that uses sequence capture targeted to the T-DNA borders to select genomic DNA fragments containing T-DNA—genome junctions, followed by Illumina sequencing to determine the location and junction structure of T-DNA insertions. Multiple probes can be mixed so that transgenic lines transformed with different T-DNA types can be processed simultaneously,more » using a simple, index-based pooling approach. We also developed a simple bioinformatic tool to find sequence read pairs that span the junction between the genome and T-DNA or any foreign DNA. We analyzed 29 transgenic lines of Arabidopsis thaliana, each containing inserts from 4 different T-DNA vectors. We determined the location of T-DNA insertions in 22 lines, 4 of which carried multiple insertion sites. Additionally, our analysis uncovered a high frequency of unconventional and complex T-DNA insertions, highlighting the needs for high-throughput methods for T-DNA localization and structural characterization. Transgene insertion events have to be fully characterized prior to use as commercial products. As a result, our method greatly facilitates the first step of this characterization of transgenic plants by providing an efficient screen for the selection of promising lines.« less

High-throughput analysis of T-DNA location and structure using sequence capture

DOE PAGES

Inagaki, Soichi; Henry, Isabelle M.; Lieberman, Meric C.; ...

2015-10-07

Agrobacterium-mediated transformation of plants with T-DNA is used both to introduce transgenes and for mutagenesis. Conventional approaches used to identify the genomic location and the structure of the inserted T-DNA are laborious and high-throughput methods using next-generation sequencing are being developed to address these problems. Here, we present a cost-effective approach that uses sequence capture targeted to the T-DNA borders to select genomic DNA fragments containing T-DNA—genome junctions, followed by Illumina sequencing to determine the location and junction structure of T-DNA insertions. Multiple probes can be mixed so that transgenic lines transformed with different T-DNA types can be processed simultaneously,more » using a simple, index-based pooling approach. We also developed a simple bioinformatic tool to find sequence read pairs that span the junction between the genome and T-DNA or any foreign DNA. We analyzed 29 transgenic lines of Arabidopsis thaliana, each containing inserts from 4 different T-DNA vectors. We determined the location of T-DNA insertions in 22 lines, 4 of which carried multiple insertion sites. Additionally, our analysis uncovered a high frequency of unconventional and complex T-DNA insertions, highlighting the needs for high-throughput methods for T-DNA localization and structural characterization. Transgene insertion events have to be fully characterized prior to use as commercial products. As a result, our method greatly facilitates the first step of this characterization of transgenic plants by providing an efficient screen for the selection of promising lines.« less

Optimizing the specificity of nucleic acid hybridization

PubMed Central

Zhang, David Yu; Chen, Sherry Xi; Yin, Peng

2014-01-01

The specific hybridization of complementary sequences is an essential property of nucleic acids, enabling diverse biological and biotechnological reactions and functions. However, the specificity of nucleic acid hybridization is compromised for long strands, except near the melting temperature. Here, we analytically derived the thermodynamic properties of a hybridization probe that would enable near-optimal single-base discrimination and perform robustly across diverse temperature, salt and concentration conditions. We rationally designed ‘toehold exchange’ probes that approximate these properties, and comprehensively tested them against five different DNA targets and 55 spurious analogues with energetically representative single-base changes (replacements, deletions and insertions). These probes produced discrimination factors between 3 and 100+ (median, 26). Without retuning, our probes function robustly from 10 °C to 37 °C, from 1 mM Mg2+ to 47 mM Mg2+, and with nucleic acid concentrations from 1 nM to 5 μM. Experiments with RNA also showed effective single-base change discrimination. PMID:22354435

Discrimination of three types of homopolymers in single-stranded DNA with solid-state nanopores through external control of the DNA motion.

PubMed

Akahori, Rena; Yanagi, Itaru; Goto, Yusuke; Harada, Kunio; Yokoi, Takahide; Takeda, Ken-Ichi

2017-08-22

To achieve DNA sequencing with solid-state nanopores, the speed of the DNA in the nanopore must be controlled to obtain sequence-specific signals. In this study, we fabricated a nanopore-sensing system equipped with a DNA motion controller. DNA strands were immobilized on a Si probe, and approach of this probe to the nanopore vicinity could be controlled using a piezo actuator and stepper motor. The area of the Si probe was larger than the area of the membrane, which meant that the immobilized DNA could enter the nanopore without the need for the probe to scan to determine the location of the nanopore in the membrane. We demonstrated that a single-stranded DNA could be inserted into and removed from a nanopore in our experimental system. The number of different ionic-current levels observed while DNA remained in the nanopore corresponded to the number of different types of homopolymers in the DNA.

Contoured Surface Eddy Current Inspection System

DOEpatents

Batzinger, Thomas James; Fulton, James Paul; Rose, Curtis Wayne; Perocchi, Lee Cranford

2003-04-08

Eddy current inspection of a contoured surface of a workpiece is performed by forming a backing piece of flexible, resiliently yieldable material with a contoured exterior surface conforming in shape to the workpiece contoured surface. The backing piece is preferably cast in place so as to conform to the workpiece contoured surface. A flexible eddy current array probe is attached to the contoured exterior surface of the backing piece such that the probe faces the contoured surface of the workpiece to be inspected when the backing piece is disposed adjacent to the workpiece. The backing piece is then expanded volumetrically by inserting at least one shim into a slot in the backing piece to provide sufficient contact pressure between the probe and the workpiece contoured surface to enable the inspection of the workpiece contoured surface to be performed.

Dose verification of eye plaque brachytherapy using spectroscopic dosimetry.

PubMed

Jarema, T; Cutajar, D; Weaver, M; Petasecca, M; Lerch, M; Kejda, A; Rosenfeld, A

2016-09-01

Eye plaque brachytherapy has been developed and refined for the last 80 years, demonstrating effective results in the treatment of ocular malignancies. Current dosimetry techniques for eye plaque brachytherapy (such as TLD- and film-based techniques) are time consuming and cannot be used prior to treatment in a sterile environment. The measurement of the expected dose distribution within the eye, prior to insertion within the clinical setting, would be advantageous, as any errors in source loading will lead to an erroneous dose distribution and inferior treatment outcomes. This study investigated the use of spectroscopic dosimetry techniques for real-time quality assurance of I-125 based eye plaques, immediately prior to insertion. A silicon detector based probe, operating in spectroscopy mode was constructed, containing a small (1 mm(3)) silicon detector, mounted within a ceramic holder, all encapsulated within a rubber sheath to prevent water infiltration of the electronics. Preliminary tests of the prototype demonstrated that the depth dose distribution through the central axis of an I-125 based eye plaque may be determined from AAPM Task Group 43 recommendations to a deviation of 6 % at 3 mm depth, 7 % at 5 mm depth, 1 % at 10 mm depth and 13 % at 20 mm depth, with the deviations attributed to the construction of the probe. A new probe design aims to reduce these discrepancies, however the concept of spectroscopic dosimetry shows great promise for use in eye plaque quality assurance in the clinical setting.

Use of a fiberscope for examining cavity nests

Treesearch

Kathryn L. Purcell

1997-01-01

A system is described that uses a fiberscope to view nests in cavities to provide detailed information on eggs and nestlings. The flexible probe can be inserted around bends, and the tip articulates to allow viewing of the entire cavity and nest. A light guide bundle furnishes light to enable viewing of dark cavities and optical fibers transmit the impage from the lens...

Dinoprostone vaginal insert versus intravenous oxytocin to reduce postpartum blood loss following vaginal or cesarean delivery.

PubMed

Ozalp, E; Tanir, H M; Sener, T

2010-01-01

To compare the impact of a dinoprostone vaginal insert and intravenous oxytocin in reducing blood loss of women undergoing vaginal or cesarean delivery. This study was conducted among term singleton pregnancies delivered vaginally or by elective cesarean section. In the vaginally delivered cases, active management of the third stage of labor was conducted. During cesarean delivery, 20 IU of intravenous oxytocin was administered. Women, who either delivered via the vaginal or abdominal route, were then randomly allocated to receive 10 mg vaginal dinoprostone insert for 12 hours (group I, n: 100) or intravenous oxytocin (group II, n: 100), respectively. Mean blood loss and need for additional uterotonics and postpartum hemoglobin and hematocrit levels at 24 and 36 hours after delivery did not differ between the two groups. Women allocated to the dinoprostone vaginal insert arm experienced more nausea and vomiting. Dinoprostone vaginal insert was as effective as intravenous oxytocin in the prevention of postpartum blood loss.

Charge separation and transport of the n=2 instability in C-2 FRC plasmas

NASA Astrophysics Data System (ADS)

Deng, Bihe; Sun, Xuan; Tuszewski, Michel

2012-10-01

Charge separation is critical in the positive feedback loop for gravitational type instabilities to grow [1], such as in the case of the n=2 mode in the C-2 field reversed configuration (FRC) experiment [2]. A fast time response Langmuir probe with minimum perturbation to the plasma is inserted into the edge of the C-2 plasma to measure the plasma floating potential. With the combined plasma wobble motion and spin motion, 2-D scans of the plasma floating potential are obtained, and evidence of charge separation associated with the n=2 instability is observed. The transport due to charge separation is estimated. Charge neutralization can provide an alternative method to stabilize the n=2 mode. An experiment is proposed to test this method with two probes inserted into the plasma from two azimuthally separated ports and an external shorting circuit, to constantly neutralize the charge separation, thus suppress the growth of the n=2 mode. [4pt] [1] R.J. Goldston and P.H. Rutherford, Introduction to Plasma Physics (Institute of Physics Publishing, Bristol, 2000).[0pt] [2]. M.W. Binderbauer et al, Phys. Rev. Lett. 105, 045003 (2010).

Determining confounding sensitivities in eddy current thin film measurements

NASA Astrophysics Data System (ADS)

Gros, Ethan; Udpa, Lalita; Smith, James A.; Wachs, Katelyn

2017-02-01

Eddy current (EC) techniques are widely used in industry to measure the thickness of non-conductive films on a metal substrate. This is done by using a system whereby a coil carrying a high-frequency alternating current is used to create an alternating magnetic field at the surface of the instrument's probe. When the probe is brought near a conductive surface, the alternating magnetic field will induce ECs in the conductor. The substrate characteristics and the distance of the probe from the substrate (the coating thickness) affect the magnitude of the ECs. The induced currents load the probe coil affecting the terminal impedance of the coil. The measured probe impedance is related to the lift off between coil and conductor as well as conductivity of the test sample. For a known conductivity sample, the probe impedance can be converted into an equivalent film thickness value. The EC measurement can be confounded by a number of measurement parameters. It was the goal of this research to determine which physical properties of the measurement set-up and sample can adversely affect the thickness measurement. The eddy-current testing was performed using a commercially available, hand-held eddy-current probe (ETA3.3H spring-loaded eddy probe running at 8 MHz) that comes with a stand to hold the probe. The stand holds the probe and adjusts the probe on the z-axis to help position the probe in the correct area as well as make precise measurements. The signal from the probe was sent to a hand-held readout, where the results are recorded directly in terms of liftoff or film thickness. Understanding the effect of certain factors on the measurements of film thickness, will help to evaluate how accurate the ETA3.3H spring-loaded eddy probe was at measuring film thickness under varying experimental conditions. This research studied the effects of a number of factors such as i) conductivity, ii) edge effect, iii) surface finish of base material and iv) cable condition.

The influence of removable partial dentures on the periodontal health of abutment and non-abutment teeth.

PubMed

Dula, Linda J; Shala, Kujtim Sh; Pustina-Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F

2015-01-01

The aim of this study was to evaluate the influence of removable partial dentures (RPD) on the periodontal health of abutment and non-abutment teeth. A total 107 patients with RPD participated in this study. It was examined 138 RPD, they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth, plaque index (PLI), calculus index (CI), bleeding on probing (BOP), probing depth (PD) (mm) and tooth mobility (TM) index. These clinical measurements were taken immediately before insertion the RPD, then one and 3 months after insertion. The level of significance was set at (P < 0.05). The mean scores for PLI, CI, BOP, PD, and TM index, of the abutment teeth and non-abutment teeth were no statistically significant at the time of insertion of RPD. After 1-month, PLI was statistically significant (0.57 ± 0.55 for abutment and 0.30 ± 0.46 for non-abutment teeth). After 3 months, there were significant differences between abutment and non-abutment teeth with regard to the BOP (1.53 ± 0.50 and 1.76 ± 0.43 respectively), PD (0.28 ± 0.45 and 0.12 ± 0.33 respectively) and PLI (1.20 ± 0.46 and 0.75 ± 0.64 respectively). No significant mean difference in TM and CI was found between the abutment and non-abutment teeth (P > 0.05). With carefully planned prosthetic treatment and adequate maintenance of the oral and denture hygiene, we can prevent the periodontal diseases.

Monitoring probe for groundwater flow

DOEpatents

Looney, Brian B.; Ballard, Sanford

1994-01-01

A monitoring probe for detecting groundwater migration. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow.

Monitoring probe for groundwater flow

DOEpatents

Looney, B.B.; Ballard, S.

1994-08-23

A monitoring probe for detecting groundwater migration is disclosed. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow. 4 figs.

Novel, Miniature Multi-Hole Probes and High-Accuracy Calibration Algorithms for their use in Compressible Flowfields

NASA Technical Reports Server (NTRS)

Rediniotis, Othon K.

1999-01-01

Two new calibration algorithms were developed for the calibration of non-nulling multi-hole probes in compressible, subsonic flowfields. The reduction algorithms are robust and able to reduce data from any multi-hole probe inserted into any subsonic flowfield to generate very accurate predictions of the velocity vector, flow direction, total pressure and static pressure. One of the algorithms PROBENET is based on the theory of neural networks, while the other is of a more conventional nature (polynomial approximation technique) and introduces a novel idea of local least-squares fits. Both algorithms have been developed to complete, user-friendly software packages. New technology was developed for the fabrication of miniature multi-hole probes, with probe tip diameters all the way down to 0.035". Several miniature 5- and 7-hole probes, with different probe tip geometries (hemispherical, conical, faceted) and different overall shapes (straight, cobra, elbow probes) were fabricated, calibrated and tested. Emphasis was placed on the development of four stainless-steel conical 7-hole probes, 1/16" in diameter calibrated at NASA Langley for the entire subsonic regime. The developed calibration algorithms were extensively tested with these probes demonstrating excellent prediction capabilities. The probes were used in the "trap wing" wind tunnel tests in the 14'x22' wind tunnel at NASA Langley, providing valuable information on the flowfield over the wing. This report is organized in the following fashion. It consists of a "Technical Achievements" section that summarizes the major achievements, followed by an assembly of journal articles that were produced from this project and ends with two manuals for the two probe calibration algorithms developed.

Technical Note: Computer-Manufactured Inserts for Prosthetic Sockets

PubMed Central

Sanders, Joan E.; McLean, Jake B.; Cagle, John C.; Gardner, David W.; Allyn, Katheryn J.

2016-01-01

The objective of this research was to use computer-aided design software and a tabletop 3-D additive manufacturing system to design and fabricate custom plastic inserts for trans-tibial prosthesis users. Shape quality of inserts was tested right after they were inserted into participant’s test sockets and again after four weeks of wear. Inserts remained properly positioned and intact throughout testing. Right after insertion the inserts caused the socket to be slightly under-sized, by a mean of 0.11 mm, approximately 55% of the thickness of a nylon sheath. After four weeks of wear the under-sizing was less, averaging 0.03 mm, approximately 15% of the thickness of a nylon sheath. Thus the inserts settled into the sockets over time. If existing prosthetic design software packages were enhanced to conduct insert design and to automatically generate fabrication files for manufacturing, then computer manufactured inserts may offer advantages over traditional methods in terms of speed of fabrication, ease of design, modification, and record keeping. PMID:27212209

Tensiometer methods

DOEpatents

Grover, Blair K.; Hubbell, Joel M.; Sisson, James B.; Casper, William L.

2005-12-20

A method for collecting data regarding a matric potential of a media includes providing a tensiometer having a stainless steel tensiometer casing, the stainless steel tensiometer casing comprising a tip portion which includes a wetted porous stainless steel membrane through which a matric potential of a media is sensed; driving the tensiometer into the media using an insertion tube comprising a plurality of probe casing which are selectively coupled to form the insertion tube as the tensiometer is progressively driven deeper into the media, wherein the wetted porous stainless steel membrane is in contact with the media; and sensing the matric potential the media exerts on the wetted porous stainless steel membrane by a pressure sensor in fluid hydraulic connection with the porous stainless steel membrane. A tensiometer includes a stainless steel casing.

Folding and insertion thermodynamics of the transmembrane WALP peptide

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

Bereau, Tristan, E-mail: bereau@mpip-mainz.mpg.de; Bennett, W. F. Drew; Pfaendtner, Jim

The anchor of most integral membrane proteins consists of one or several helices spanning the lipid bilayer. The WALP peptide, GWW(LA){sub n} (L)WWA, is a common model helix to study the fundamentals of protein insertion and folding, as well as helix-helix association in the membrane. Its structural properties have been illuminated in a large number of experimental and simulation studies. In this combined coarse-grained and atomistic simulation study, we probe the thermodynamics of a single WALP peptide, focusing on both the insertion across the water-membrane interface, as well as folding in both water and a membrane. The potential of meanmore » force characterizing the peptide’s insertion into the membrane shows qualitatively similar behavior across peptides and three force fields. However, the Martini force field exhibits a pronounced secondary minimum for an adsorbed interfacial state, which may even become the global minimum—in contrast to both atomistic simulations and the alternative PLUM force field. Even though the two coarse-grained models reproduce the free energy of insertion of individual amino acids side chains, they both underestimate its corresponding value for the full peptide (as compared with atomistic simulations), hinting at cooperative physics beyond the residue level. Folding of WALP in the two environments indicates the helix as the most stable structure, though with different relative stabilities and chain-length dependence.« less

Folding and insertion thermodynamics of the transmembrane WALP peptide

NASA Astrophysics Data System (ADS)

Bereau, Tristan; Bennett, W. F. Drew; Pfaendtner, Jim; Deserno, Markus; Karttunen, Mikko

2015-12-01

The anchor of most integral membrane proteins consists of one or several helices spanning the lipid bilayer. The WALP peptide, GWW(LA)n (L)WWA, is a common model helix to study the fundamentals of protein insertion and folding, as well as helix-helix association in the membrane. Its structural properties have been illuminated in a large number of experimental and simulation studies. In this combined coarse-grained and atomistic simulation study, we probe the thermodynamics of a single WALP peptide, focusing on both the insertion across the water-membrane interface, as well as folding in both water and a membrane. The potential of mean force characterizing the peptide's insertion into the membrane shows qualitatively similar behavior across peptides and three force fields. However, the Martini force field exhibits a pronounced secondary minimum for an adsorbed interfacial state, which may even become the global minimum—in contrast to both atomistic simulations and the alternative PLUM force field. Even though the two coarse-grained models reproduce the free energy of insertion of individual amino acids side chains, they both underestimate its corresponding value for the full peptide (as compared with atomistic simulations), hinting at cooperative physics beyond the residue level. Folding of WALP in the two environments indicates the helix as the most stable structure, though with different relative stabilities and chain-length dependence.

Motorized fusion guided prostate biopsy: phantom study

NASA Astrophysics Data System (ADS)

Seifabadi, Reza; Xu, Sheng; Aalamifar, Fereshteh; Pinto, Peter; Wood, Bradford J.

2017-03-01

Purpose: Fusion of Magnetic Resonance Imaging (MRI) with intraoperative real-time Ultrasound (US) during prostate biopsy has significantly improved the sensitivity of transrectal ultrasound (TRUS) guided cancer detection. Currently, sweeping of the TRUS probe to build a 3D volume as part of the fusion process and the TRUS probe manipulation for needle guidance are both done manually. A motorized, joystick controlled, probe holder was custom fabricated that can potentially reduce inter-operator variability, provide standardization of needle placement, improve repeatability and uniformity of needle placement, which may have impacts upon the learning curve after clinical deployment of this emerging approach. Method: a 2DOF motorized probe holder was designed to provide translation and rotation of a triplane TRUS end firing probe for prostate biopsy. The probe holder was joystick controlled and can assist manipulation of the probe during needle insertion as well as in acquiring a smoother US 2D to 3D sweep in which the 3D US volume for fusion is built. A commercial MRI-US fusion platform was used. Three targets were specified on MR image of a commercial prostate phantom. After performing the registration, two operators performed targeting, once manually and once with the assistance of the motorized probe holder. They repeated these tasks 5 times resulting in a total of 30 targeting events. Time of completion and mechanical error i.e. distance of the target from the needle trajectory in the software user interface were measured. Repeatability in reaching a given target in a systematic and consistent way was measured using a scatter plot showing all targets in the US coordinate system. Pearson product-moment correlation coefficient (PPMCC) was used to demonstrate the probe steadiness during targeting. Results: the completion time was 25+/-17 sec, 25+/-24 sec, and 27+/-15 sec for free hand and 24+/-10 sec, 22.5+/-10 sec, and 37+/-10 sec for motorized insertion, for target 1, 2, and 3, respectively. The mechanical error was 0.75+/-0.4 mm, 0.45+/-0.4 mm, and 0.55+/-0.4 mm, for free hand approach while it was 1.0+/-0.57 mm, 0.45+/-0.4 mm, and 0.35+/-0.25 mm, for motorized approach, for target 1, 2, and 3, respectively. PPMCC remained almost at 1.0 for the motorized approach while having a variation between 0.9 and 1.0 for the free hand approach. Conclusions: motorized fusion guided prostate biopsy in a phantom study was feasible and non-inferior or comparable to the free hand manual approach in terms of accuracy and speed of targeting, while being superior in terms of repeatability and steadiness.

Neural Interfaces for Intracortical Recording: Requirements, Fabrication Methods, and Characteristics

PubMed Central

Szostak, Katarzyna M.; Grand, Laszlo; Constandinou, Timothy G.

2017-01-01

Implantable neural interfaces for central nervous system research have been designed with wire, polymer, or micromachining technologies over the past 70 years. Research on biocompatible materials, ideal probe shapes, and insertion methods has resulted in building more and more capable neural interfaces. Although the trend is promising, the long-term reliability of such devices has not yet met the required criteria for chronic human application. The performance of neural interfaces in chronic settings often degrades due to foreign body response to the implant that is initiated by the surgical procedure, and related to the probe structure, and material properties used in fabricating the neural interface. In this review, we identify the key requirements for neural interfaces for intracortical recording, describe the three different types of probes—microwire, micromachined, and polymer-based probes; their materials, fabrication methods, and discuss their characteristics and related challenges. PMID:29270103

The first neural probe integrated with light source (blue laser diode) for optical stimulation and electrical recording.

PubMed

Park, HyungDal; Shin, Hyun-Joon; Cho, Il-Joo; Yoon, Eui-sung; Suh, Jun-Kyo Francis; Im, Maesoon; Yoon, Euisik; Kim, Yong-Jun; Kim, Jinseok

2011-01-01

In this paper, we report a neural probe which can selectively stimulate target neurons optically through Si wet etched mirror surface and record extracellular neural signals in iridium oxide tetrodes. Consequently, the proposed approach provides to improve directional problem and achieve at least 150/m gap distance between stimulation and recording sites by wet etched mirror surface in V-groove. Also, we developed light source, blue laser diode (OSRAM Blue Laser Diode_PL 450), integration through simple jig for one-touch butt-coupling. Furthermore, optical power and impedance of iridium oxide tetrodes were measured as 200 μW on 5 mW from LD and 206.5 k Ω at 1 kHz and we demonstrated insertion test of probe in 0.5% agarose-gel successfully. We have successfully transmitted a light of 450 nm to optical fiber through the integrated LD using by butt-coupling method.

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

Hauer, John F.; Mittelstadt, William; Martin, Kenneth E.

During 2005 and 2006 the Western Electricity Coordinating Council (WECC) performed three major tests of western system dynamics. These tests used a Wide Area Measurement System (WAMS) based primarily on Phasor Measurement Units (PMUs) to determine response to events including the insertion of the 1400-MW Chief Joseph braking resistor, probing signals, and ambient events. Test security was reinforced through real-time analysis of wide area effects, and high-quality data provided dynamic profiles for interarea modes across the entire western interconnection. The tests established that low-level optimized pseudo-random ±20-MW probing with the Pacific DC Intertie (PDCI) roughly doubles the apparent noise thatmore » is natural to the power system, providing sharp dynamic information with negligible interference to system operations. Such probing is an effective alternative to use of the 1400-MW Chief Joseph dynamic brake, and it is under consideration as a standard means for assessing dynamic security.« less

Coupling Microdialysis Sampling to Microchip Electrophoresis in a Reversibly Sealed Device

PubMed Central

Mecker, Laura C.; Martin, R. Scott

2007-01-01

In this paper, we describe the fabrication and characterization of a reversibly sealed microchip device that is used to couple microdialysis sampling to microchip electrophoresis. The ability to interface microdialysis sampling and microchip electrophoresis in a device that is amenable to reversible sealing is advantageous from a repeated use standpoint. Commercially available tubing coming from the microdialysis probe is directly inserted into the chip and flow from the probe is interfaced to the electrophoresis portion of the device through integrated pneumatic valves. Fluorescence detection was used to characterize the poly(dimethylsiloxane)-based device in terms of injection reproducibility. It was found that the entire system (microdialysis probe and microchip device) has a concentration response lag time of 170 sec. Microdialysis sampling followed by an electrophoretic separation of amino acids derivatized with naphthalene-2,3-dicarboxaldehyde/cyanide was also demonstrated. PMID:18836517

3D silicon neural probe with integrated optical fibers for optogenetic modulation.

PubMed

Kim, Eric G R; Tu, Hongen; Luo, Hao; Liu, Bin; Bao, Shaowen; Zhang, Jinsheng; Xu, Yong

2015-07-21

Optogenetics is a powerful modality for neural modulation that can be useful for a wide array of biomedical studies. Penetrating microelectrode arrays provide a means of recording neural signals with high spatial resolution. It is highly desirable to integrate optics with neural probes to allow for functional study of neural tissue by optogenetics. In this paper, we report the development of a novel 3D neural probe coupled simply and robustly to optical fibers using a hollow parylene tube structure. The device shanks are hollow tubes with rigid silicon tips, allowing the insertion and encasement of optical fibers within the shanks. The position of the fiber tip can be precisely controlled relative to the electrodes on the shank by inherent design features. Preliminary in vivo rat studies indicate that these devices are capable of optogenetic modulation simultaneously with 3D neural signal recording.

Enhancing electron transport in molecular wires by insertion of a ferrocene center.

PubMed

Sun, Yan-Yan; Peng, Zheng-Lian; Hou, Rong; Liang, Jing-Hong; Zheng, Ju-Fang; Zhou, Xiao-Yi; Zhou, Xiao-Shun; Jin, Shan; Niu, Zhen-Jiang; Mao, Bing-Wei

2014-02-14

We have determined the conductance of alkane-linked ferrocene molecules with carboxylic acid anchoring groups using the STM break junction technique, and three sets of conductance values were found, i.e. high conductance (HC), medium conductance (MC) and low conductance (LC) values. The enhancing effect of the incorporated ferrocene on the electron transport in saturated alkane molecular wires is demonstrated by the increased conductance of the ferrocene molecules, attributed to the reduction of the tunneling barrier and the HOMO-LUMO gap induced by the insertion of ferrocene. Furthermore, the electron-withdrawing carbonyl group on the unconjugated backbone has little or no influence on single-molecule conductance. The current work provides a feasible approach for the design of high-performance molecular wires.

Radial and circumferential flow surveys at the inlet and exit of the Space Shuttle Main Engine High Pressure Fuel Turbine Model

NASA Technical Reports Server (NTRS)

Hudson, S. T.; Bordelon, W. J., Jr.; Smith, A. W.; Ramachandran, N.

1995-01-01

The main objective of this test was to obtain detailed radial and circumferential flow surveys at the inlet and exit of the SSME High Pressure Fuel Turbine model using three-hole cobra probes, hot-film probes, and a laser velocimeter. The test was designed to meet several objectives. First, the techniques for making laser velocimeter, hot-film probe, and cobra probe measurements in turbine flows were developed and demonstrated. The ability to use the cobra probes to obtain static pressure and, therefore, velocity had to be verified; insertion techniques had to be established for the fragile hot-film probes; and a seeding method had to be established for the laser velocimetry. Once the measurement techniques were established, turbine inlet and exit velocity profiles, temperature profiles, pressure profiles, turbulence intensities, and boundary layer thicknesses were measured at the turbine design point. The blockage effect due to the model inlet and exit total pressure and total temperature rakes on the turbine performance was also studied. A small range of off-design points were run to obtain the profiles and to verify the rake blockage effects off-design. Finally, a range of different Reynolds numbers were run to study the effect of Reynolds number on the various measurements.

Intra-opeartive OCT imaging and sensing devices for clinical translation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Chen, Yu

2017-02-01

Stereotactic procedures that require insertion of needle-based instruments into the brain serve important roles in a variety of neurosurgical interventions, such as biopsy, catheterization, and electrode placement. A fundamental limitation of these stereotactic procedures is that they are blind procedures in that the operator does not have real-time feedback as to what lies immediately ahead of the advancing needle. Therefore, there is a great clinical need to navigate the instrument safely and accurately to the targets. Towards that end, we developed a forwarding-imaging needle-type optical coherence tomography (OCT) probe for avoiding the hemorrhage and guiding neurosurgical interventions. The needle probe has a thin diameter of 0.7 mm. The feasibility of vessel detection and neurosurgical guidance were demonstrated on sheep brain in vivo and human brain ex vivo. In addition, we further reduced the probe size to 0.3 mm using an optical Doppler sensing (ODS) fiber probe that can integrate with microelectrode recording (MER) to detect the blood vessels lying ahead to improve the safety of this procedure. Furthermore, to overcome the field-of-view limitation of OCT probe, we developed an MRI-compatible OCT imaging probe for neurosurgery. MRI/OCT multi-scale imaging integrates micro-resolution optical imaging with wide-field MRI imaging, and has potential to further improve the targeting accuracy.

Insights into the surface topology of polyhydroxyalkanoate synthase: self-assembly of functionalized inclusions.

PubMed

Hooks, David O; Rehm, Bernd H A

2015-10-01

The polyhydroxyalkanoate (PHA) synthase catalyzes the synthesis of PHA and remains attached to the hydrophobic PHA inclusions it creates. Although this feature is actively exploited to generate functionalized biobeads via protein engineering, little is known about the structure of the PHA synthase. Here, the surface topology of Ralstonia eutropha PHA synthase was probed to inform rational protein engineering toward the production of functionalized PHA beads. Surface-exposed residues were detected by conjugating biotin to inclusion-bound PHA synthase and identifying the biotin-conjugated lysine and cysteine residues using peptide fingerprinting analysis. The identified sites (K77, K90, K139, C382, C459, and K518) were investigated as insertion sites for the generation of new protein fusions. Insertions of FLAG epitopes into exposed sites K77, K90, K139, and K518 were tolerated, retaining >65 % of in vivo activity. Sites K90, K139, and K518 were also tested by insertion of the immunoglobulin G (IgG)-binding domain (ZZ), successfully producing PHA inclusions able to bind human IgG in vitro. Although simultaneous insertions of the ZZ domain into two sites was permissive, insertion at all three lysine sites inactivated the synthase. The K90/K139 double ZZ insertion had the optimum IgG-binding capacity of 16 mg IgG/g wet PHA beads and could selectively purify the IgG fraction from human serum. Overall, this study identified surface-exposed flexible regions of the PHA synthase which either tolerate protein/peptide insertions or are critical for protein function. This further elucidates the structure and function of PHA synthase and provides new opportunities for generating functionalized PHA biobeads.

48 CFR 2437.110 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... insert the clause at 2452.237-72, Coordination of Data Collection Activities, in solicitations and...) The Contracting Officer shall insert the clause at 48 CFR 2452.237-73, Conduct of Work and Technical...

OEDGE Modeling of Collector Probe measurements in L-mode from the DIII-D tungsten ring campaign

NASA Astrophysics Data System (ADS)

Elder, J. D.; Stangeby, P. C.; Unterberg, Z.; Donovan, D.; Wampler, W. R.; Watkins, J.; Abrams, T.; McLean, A. G.

2017-10-01

During the tungsten ring campaign on DIII-D, a collector probe system with multiple diameter, dual-facing collector rods was inserted into the far scrape off layer (SOL) near the outer midplane to measure the plasma tungsten content. For most probes more tungsten was observed on the side connected along field lines to the inner divertor, with the larger probes showing largest divertor-facing asymmetries The OEDGE code is used to model the tungsten erosion, transport and deposition. It has been enhanced with (i) a peripheral particle transport and deposition model to record the impurity content in the peripheral region outside the regular mesh, and (ii) a collector probe model. The OEDGE results approximately reproduce both the divertor-facing asymmetries and the radial decay of each collector probe profile. The effect of changing impurity transport assumptions and wall location are examined. The measured divertor-facing asymmetries imply a higher tungsten density in the plasma upstream of the probe; this was expected theoretically from the effect of the parallel ion temperature gradient force driving upstream transport of tungsten from the outer divertor and was also found in the code analysis. Work supported by the US Department of Energy under DE-FC02-04ER54698, DE-NA0003525, DE-AC05-00OR22725, and DE-AC52-07NA27344.

Microscale Electrode Implantation during Nerve Repair: Effects on Nerve Morphology, Electromyography, and Recovery of Muscle Contractile Function

PubMed Central

Urbanchek, Melanie G; Wei, Benjamin; Egeland, Brent M; Abidian, Mohammad R; Kipke, Daryl R; Cederna, Paul S

2011-01-01

Background Our goal is to develop a peripheral nerve electrode with long-term stability and fidelity for use in nerve-machine interfaces. Microelectromechanical systems (MEMS) use silicon probes that contain multi-channel actuators, sensors, and electronics. We tested the null hypothesis that implantation of MEMS probes do not have a detrimental effect on peripheral nerve function or regeneration. Methods A rat hindlimb, peroneal nerve model was utilized in all experimental groups: a) intact nerve (Control, n= 10); b) nerve division and repair (Repair, n= 9); and c) Nerve division, insertion of MEMS probe, and repair (Repair + Probe, n=9). Nerve morphology, nerve to muscle compound action potential (CMAP) studies, walking tracks, and extensor digitorum longus (EDL) muscle function tests were evaluated following an 80 day recovery. Results Repair and Repair + Probe showed no differences in axon count, axon size, percent non-neural area, CMAP amplitude, latency, muscle mass, muscle force, or walking track scores. Though there was some local fibrosis around each MEMS probe, this did not lead to measurable detrimental effects in any anatomic or functional outcome measurements. Conclusions The lack of a significant difference between Repair and Repair + Probe groups in histology, CMAP, walking tracks, and muscle force suggests that MEMS electrodes are compatible with regenerating axons and show promise for establishing chemical and electrical interfaces with peripheral nerves. PMID:21921739

Studies on interaction of an intramolecular charge transfer fluorescence probe: 4'-dimethylamino-2,5-dihydroxychalcone with DNA.

PubMed

Xu, Zhicheng; Bai, Guan; Dong, Chuan

2005-10-15

The interaction of a new intramolecular charge transfer probe, namely 4'-dimethylamino-2,5-dihydroxychalcone (DMADHC), with calf thymus DNA has been studied. Compared to the spectral characteristics of the free form in aqueous solution, the fluorescence of DMADHC enhanced dramatically accompanying a blueshift of the emission maxima in the presence of DNA. The absorption and fluorescence spectra, salt concentration effect, KI quenching, fluorescence polarization, and DNA denaturation experiments were given. These results give evidence that the DMADHC molecule is inserted into the base-stacking domain of the DNA double helix. The intrinsic binding constant and the binding site number were estimated. The analytical characteristics were also given.

Method and apparatus for preloading a joint by remotely operable means

NASA Technical Reports Server (NTRS)

Kahn, Jon B. (Inventor)

1993-01-01

The invention is a method and apparatus for joining structures, an active structure and a passive structure, and imposing a tensile pre-load on the joint by a remotely operable mechanism comprising a heat contractible joining element. The method and apparatus include mounting on the structure, a probe shaft of material which is transformable from an expanded length to a contracted length when heated to a specific temperature range. The shaft is provided with a probe head which is receivable in a receptacle opening formed in the passive structure, when the active structure is moved into engagement therewith by an appropriate manipulator mechanism. A latching system mounted on the structure adjacent to the receptacle opening captures the probe head, when the probe head is inserted a predetermined amount. A heating coil on the shaft is energizable by remote control for heating the shaft to a temperature range which transforms the shaft to its contracted length, whereby a latching shoulder thereof engages latching elements of the latching system and imposes a tensile preload on the structural joint. Provision is also made for manually adjusting the probe head on the shaft to allow for manual detachment of the structures or manual preloading of the structural joint.

Method and apparatus for preloading a joint by remotely operable means

NASA Technical Reports Server (NTRS)

Shelton, Robert O. (Inventor)

1992-01-01

The invention is a method and apparatus for joining structures, an active structure and a passive structure, and imposing a tensile pre-load on the joint by a remotely operable mechanism comprising a heat contractible joining element. The method and apparatus include mounting on the structure, a probe shaft of material which is transformable from an expanded length to a contracted length when heated to a specific temperature range. The shaft is provided with a probe head which is receivable in a receptacle opening formed in the passive structure, when the active structure is moved into engagement therewith by an appropriate manipulator mechanism. A latching system mounted on the structure adjacent to the receptacle opening captures the probe head, when the probe head is inserted a predetermined amount. A heating coil on the shaft is energizable by remote control for heating the shaft to a temperature range which transforms the shaft to its contracted length, whereby a latching shoulder thereof engages latching elements of the latching system and imposes a tensile preload on the structural joint. Provision is also made for manually adjusting the probe head on the shaft to allow for manual detachment of the structures or manual preloading of the structural joint.

Accuracy of non-operative identification of the sentinel lymph node using combined gamma and ultrasound scanning.

PubMed

Whelehan, P; Vinnicombe, S J; Brown, D C; McLean, D; Evans, A

2014-08-01

To assess how accurately the sentinel lymph node (SLN) can be identified percutaneously, using gamma probe and ultrasound technology. Women with breast cancer, scheduled for wide local excision or mastectomy with SLN biopsy (SLNB), were included. Peri-areolar intradermal injection of technetium-99 nanocolloid was performed on the morning of surgery and 1-2 ml of blue dye was injected in the peri-areolar region once the patient was anaesthetized. Prior to surgery, a gamma probe was used over the skin to identify any hot spot that could represent a SLN. Ultrasound, guided by the hot spot, was then used to visualize potential SLNs and guide the insertion of a localizing wire. The accuracy in localizing the SLN by preoperative gamma-probe guided ultrasonography was assessed by comparison to SLNB. A SLN was correctly identified and marked using gamma-probe guided ultrasonography in 44 of 59 cases (75%; 95% CI: 63-86%). This study supports the case for investigating percutaneous gamma probe and ultrasound guided interventions in the axilla in women with breast cancer, as a potential alternative to surgical SLNB. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Optical probe for determining the fat/lean interface in cuts of meat

DOEpatents

Weber, Thomas M.; Callow, Diane S.; Jones, James F.; Kuehl, Michael A.; Spletzer, Barry L.

2005-02-22

An apparatus and method for locating the boundary surface between a layer of fatty tissue and lean tissue in a cut of meat, such as beef, such as slabs of meat undergoing trimming and cutting in commercial meet processing facilitates. The invention exploits the fact that fatty tissue and lean tissue have significantly different responses to incident light energy. By gauging the degree to which a generated beam of light is scattered and reflected by the tissues under evaluation, the invention permits the character of the tissue to be ascertained. An incident beam of light, such as green light, is generated and transmitted to a probe tip, which tip is inserted into the cut of meat under investigation. The light beam is emitted into the meat tissues from the probe tip, and then is scattered and reflected by the tissues, whereupon some fraction of the emitted light returns to the probe tip. The returning light energy is transmitted to a detector; relative changes in the returning light transmitted to the detector permit the operator to determine when the probe tip is approaching or penetrating the fat/lean tissue interface.

Myofibroblasts Electrotonically Coupled to Cardiomyocytes Alter Conduction: Insights at the Cellular Level from a Detailed In silico Tissue Structure Model

PubMed Central

Jousset, Florian; Maguy, Ange; Rohr, Stephan; Kucera, Jan P.

2016-01-01

Fibrotic myocardial remodeling is typically accompanied by the appearance of myofibroblasts (MFBs). In vitro, MFBs were shown to slow conduction and precipitate ectopic activity following gap junctional coupling to cardiomyocytes (CMCs). To gain further mechanistic insights into this arrhythmogenic MFB-CMC crosstalk, we performed numerical simulations in cell-based high-resolution two-dimensional tissue models that replicated experimental conditions. Cell dimensions were determined using confocal microscopy of single and co-cultured neonatal rat ventricular CMCs and MFBs. Conduction was investigated as a function of MFB density in three distinct cellular tissue architectures: CMC strands with endogenous MFBs, CMC strands with coating MFBs of two different sizes, and CMC strands with MFB inserts. Simulations were performed to identify individual contributions of heterocellular gap junctional coupling and of the specific electrical phenotype of MFBs. With increasing MFB density, both endogenous and coating MFBs slowed conduction. At MFB densities of 5–30%, conduction slowing was most pronounced in strands with endogenous MFBs due to the MFB-dependent increase in axial resistance. At MFB densities >40%, very slow conduction and spontaneous activity was primarily due to MFB-induced CMC depolarization. Coating MFBs caused non-uniformities of resting membrane potential, which were more prominent with large than with small MFBs. In simulations of MFB inserts connecting two CMC strands, conduction delays increased with increasing insert lengths and block appeared for inserts >1.2 mm. Thus, electrophysiological properties of engineered CMC-MFB co-cultures depend on MFB density, MFB size and their specific positioning in respect to CMCs. These factors may influence conduction characteristics in the heterocellular myocardium. PMID:27833567

Building large mosaics of confocal edomicroscopic images using visual servoing.

PubMed

Rosa, Benoît; Erden, Mustafa Suphi; Vercauteren, Tom; Herman, Benoît; Szewczyk, Jérôme; Morel, Guillaume

2013-04-01

Probe-based confocal laser endomicroscopy provides real-time microscopic images of tissues contacted by a small probe that can be inserted in vivo through a minimally invasive access. Mosaicking consists in sweeping the probe in contact with a tissue to be imaged while collecting the video stream, and process the images to assemble them in a large mosaic. While most of the literature in this field has focused on image processing, little attention has been paid so far to the way the probe motion can be controlled. This is a crucial issue since the precision of the probe trajectory control drastically influences the quality of the final mosaic. Robotically controlled motion has the potential of providing enough precision to perform mosaicking. In this paper, we emphasize the difficulties of implementing such an approach. First, probe-tissue contacts generate deformations that prevent from properly controlling the image trajectory. Second, in the context of minimally invasive procedures targeted by our research, robotic devices are likely to exhibit limited quality of the distal probe motion control at the microscopic scale. To cope with these problems visual servoing from real-time endomicroscopic images is proposed in this paper. It is implemented on two different devices (a high-accuracy industrial robot and a prototype minimally invasive device). Experiments on different kinds of environments (printed paper and ex vivo tissues) show that the quality of the visually servoed probe motion is sufficient to build mosaics with minimal distortion in spite of disturbances.

Long-term effect of tetracycline fibers on recurrent lesions in periodontal maintenance patients.

PubMed

Corsair, A

1994-01-01

Thirty-one patients with chronic adult periodontitis participated in this long-term private practice study. Sixty-one sites with moderate (4-6 mm, n = 21) or deep (> or = 7 mm, n = 40) periodontal pockets and bleeding on probing were treated with an antibiotic-releasing fiber, Actisite (Periodontal Therapeutic System) (tetracycline hydrochloride). Scaling/root planing (SRP) was performed on all teeth 3 weeks before start of the study, and on most teeth immediately before fiber insertion. Monolithic fibers loaded with 25% tetracycline hydrochloride were inserted in periodontal pockets, where they were retained for a mean of 6.7 days, at which point they were removed. Patients were evaluated at 1, 3, and 6 months after treatment; subgroups were also evaluated at normalized 12-month (10 patients, 20 sites) and 24-month (13 patients, 20 sites) time points. Sites showed a mean probing depth reduction of 2.5 mm at 6 months, and 2.2 mm at 24 months, with the deepest sites showing the greatest reduction. Bleeding on probing was 100% at baseline, 34% at 3 months, and 50% at 6 months. Attachment gains in 18 patients (25 sites) were 2.4 mm at 1 month, 3.0 mm at 3 months, and 2.5 mm at 6 months. Fibers were well tolerated; no adverse effects from treatment were noted. These results indicate that use of tetracycline fiber plus SRP clearly reduced the clinical signs of periodontal disease and maintained or improved attachment for up to 24 months in sites previously refractory to treatment.

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

Yordanov, D., E-mail: yordanov@phys.uni-sofia.bg; Lishev, St.; Shivarova, A.

Shielding the bias applied to the probe by the sheath formed around it and determination of parameters of unperturbed plasmas are in the basis of the probe diagnostics. The results from a two-dimensional model of a discharge with a probe inserted in it show that the probe influences the spatial distribution of the plasma parameters in the entire discharge. The increase (although slight) in the electron temperature, due to the increased losses of charged particles on the additional wall in the discharge (mainly the probe holder), leads to redistribution of the plasma density and plasma potential, as shown by themore » results obtained at the floating potential of the probe. The deviations due to the bias applied to the probe tip are stronger in the ion saturation region of the probe characteristics. The pattern of the spatial redistribution of the plasma parameters advances together with the movement of the probe deeper in the discharge. Although probe sheaths and probe characteristics resulting from the model are shown, the study does not aim at discussions on the theories for determination of the plasma density from the ion saturation current. Regardless of the modifications in the plasma behavior in the entire discharge, the deviations of the plasma parameters at the position of the probe tip and, respectively, the uncertainty which should be added as an error when the accuracy of the probe diagnostics is estimated do not exceed 10%. Consequently, the electron density and temperature obtained, respectively, at the position of the plasma potential on the probe characteristics and from its transition region are in reasonable agreement with the results from the model of the discharge without a probe. Being in the scope of research on a source of negative hydrogen ions with the design of a matrix of small radius inductive discharges, the model is specified for a low-pressure hydrogen discharge sustained in a small-radius tube.« less

Evaluation of in vivo solid phase microextraction for minimally invasive analysis of nonvolatile phytochemicals in Amazonian plants.

PubMed

Musteata, Florin Marcel; Sandoval, Manuel; Ruiz-Macedo, Juan C; Harrison, Kathleen; McKenna, Dennis; Millington, William

2016-08-24

Although solid phase microextraction (SPME) has been used extensively for fingerprinting volatile compounds emitted by plants, there are very few such reports for direct insertion SPME. In this research, direct contact of SPME probes with the interstitial fluid of plants was investigated as a method for phytochemical analysis. Medicinal plants from the Amazon have been the source of numerous drugs used in western medicine. However, a large number of species used in traditional medicine have not been characterized chemically, partly due to the difficulty of field work. In this project, the phytochemical composition of plants from several genera was fingerprinted by combining convenient field sampling by solid phase microextraction (SPME) with laboratory analysis by LC-MS. The new method was compared with classical sampling followed by liquid extraction (LE). SPME probes were prepared by coating stainless steel wires with a mixture of polyacrylonitrile and either RP-amide or HS-F5 silica particles. Sampling was performed by inserting the microextraction probes into various tissues of living plants in their natural environment. After in vivo extraction, the probes were sealed under vacuum and refrigerated until analyzed. The probes were desorbed in mobile phase and analyzed on a Waters Acquity UPLC with triple quadrupole mass spectrometer in positive ion mode. Twenty Amazonian plant species were sampled and unique metabolomic fingerprints were obtained. In addition, quantitative analysis was performed for previously identified compounds in three species. Comparison of the fingerprints obtained by in vivo SPME with those obtained by LE showed that 27% of the chromatographic features were unique to SPME, 57% were unique to LE, and 16% were common to both methods. In vivo SPME caused minimal damage to the plants, was much faster than traditional liquid extraction, and provided unique fingerprints for all investigated plants. SPME revealed unique chromatographic features, undetected by traditional extraction, although it produced only half as many peaks as ethanol extraction. Copyright © 2016 Elsevier B.V. All rights reserved.

General expressions for the coupling coefficient, quality and filling factors for a cavity with an insert using energy coupled mode theory.

PubMed

Elnaggar, Sameh Y; Tervo, Richard; Mattar, Saba M

2014-05-01

A cavity (CV) with a dielectric resonator (DR) insert forms an excellent probe for the use in electron paramagnetic resonance (EPR) spectrometers. The probe's coupling coefficient, κ, the quality factor, Q, and the filling factor, η are vital in assessing the EPR spectrometer's performance. Coupled mode theory (CMT) is used to derive general expressions for these parameters. For large permittivity the dominating factor in κ is the ratio of the DR and CV cross sectional areas rather than the dielectric constant. Thus in some cases, resonators with low dielectric constant can couple much stronger with the cavity than do resonators with a high dielectric constant. When the DR and CV frequencies are degenerate, the coupled η is the average of the two uncoupled ones. In practical EPR probes the coupled η is approximately half of that of the DR. The Q of the coupled system generally depends on the eigenvectors, uncoupled frequencies (ω1,ω2) and the individual quality factors (Q1,Q2). It is calculated for different probe configurations and found to agree with the corresponding HFSS® simulations. Provided there is a large difference between the Q1, Q2 pair and the frequencies of DR and CV are degenerate, Q is approximately equal to double the minimum of Q1 and Q2. In general, the signal enhancement ratio, Iwithinsert/Iempty, is obtained from Q and η. For low loss DRs it only depends on η1/η2. However, when the DR has a low Q, the uncoupled Qs are also needed. In EPR spectroscopy it is desirable to excite only a single mode. The separation between the modes, Φ, is calculated as a function of κ and Q. It is found to be significantly greater than five times the average bandwidth. Thus for practical probes, it is possible to excite one of the coupled modes without exciting the other. The CMT expressions derived in this article are quite general and are in excellent agreement with the lumped circuit approach and finite numerical simulations. Hence they can also be applied to a loop-gap resonator in a cavity. For the design effective EPR probes, one needs to consider the κ, Q and η parameters. Copyright © 2014 Elsevier Inc. All rights reserved.

Task Shifting Provision of Contraceptive Implants to Community Health Extension Workers: Results of Operations Research in Northern Nigeria

PubMed Central

Oguntunde, Olugbenga; Orobaton, Nosa; Otolorin, Emmanuel; Inuwa, Fatima; Alalade, Olubisi; Abegunde, Dele; Danladi, Saba’atu

2015-01-01

Background: Contraceptive use remains low in Nigeria, with only 11% of women reporting use of any modern method. Access to long-acting reversible contraceptives (LARCs) is constrained by a severe shortage of human resources. To assess feasibility of task shifting provision of implants, we trained community health extension workers (CHEWs) to insert and remove contraceptive implants in rural communities of Bauchi and Sokoto states in northern Nigeria. Methods: We conducted 2- to 3-week training sessions for 166 selected CHEWs from 82 facilities in Sokoto state (September 2013) and 84 health facilities in Bauchi state (December 2013). To assess feasibility of the task shifting approach, we conducted operations research using a pretest–posttest design using multiple sources of information, including surveys with 151 trained CHEWs (9% were lost to follow-up) and with 150 family planning clients; facility observations using supply checklists (N = 149); direct observation of counseling provided by CHEWs (N = 144) and of their clinical (N = 113) skills; as well as a review of service statistics (N = 151 health facilities). The endline assessment was conducted 6 months after the training in each state. Results: CHEWs inserted a total of 3,588 implants in 151 health facilities over a period of 6 months, generating 10,088 couple-years of protection (CYP). After practicing on anatomic arm models, most CHEWs achieved competency in implant insertions after insertions with 4–5 actual clients. Clinical observations revealed that CHEWs performed implant insertion tasks correctly 90% of the time or more for nearly all checklist items. The amount of information that CHEWs provided clients increased between baseline and endline, and over 95% of surveyed clients reported being satisfied with CHEWs’ services in both surveys. The study found that supervisors not only observed and corrected insertion skills, as needed, during supervisory visits but also encouraged CHEWs to conduct more community mobilization to generate client demand, thereby promoting access to quality services. CHEWs identified a lack of demand in the communities as the major barrier for providing services. Conclusion: With adequate training and supportive supervision, CHEWs in northern Nigeria can provide high-quality implant insertion services. If more CHEWs are trained to provide implants and greater community outreach is conducted to generate demand, uptake of LARCs in Nigeria may increase. PMID:26374800

Force modulation and electrochemical gating of conductance in a cytochrome

NASA Astrophysics Data System (ADS)

Davis, Jason J.; Peters, Ben; Xi, Wang

2008-09-01

Scanning probe methods have been used to measure the effect of electrochemical potential and applied force on the tunnelling conductance of the redox metalloprotein yeast iso-1-cytochrome c (YCC) at a molecular level. The interaction of a proximal probe with any sample under test will, at this scale, be inherently perturbative. This is demonstrated with conductive probe atomic force microscopy (CP-AFM) current-voltage spectroscopy in which YCC, chemically adsorbed onto pristine Au(111) via its surface cysteine residue, is observed to become increasingly compressed as applied load is increased, with concomitant decrease in junction resistance. Electrical contact at minimal perturbation, where probe-molecule coupling is comparable to that in scanning tunnelling microscopy, brings with it the observation of negative differential resistance, assigned to redox-assisted probe-substrate tunnelling. The role of the redox centre in conductance is also resolved in electrochemical scanning tunnelling microscopy assays where molecular conductance is electrochemically gateable through more than an order of magnitude.

Plant Available Nutrients, Barrow, Alaska, Ver. 1

DOE Data Explorer

Sloan, Victoria; Liebig, Jenny; Curtis, Bryan; Hahn, Melanie; Iversen, Colleen; Siegrist, Julie

2014-02-19

This dataset consists of measurements of plant available nutrients made using Plant Root Simulator probes (Western Ag Innovations Inc.) during 2012 and 2013. In 2012, Ca, Mg, K, P, Fe, Mn, Cu, Zn, B, S, Pb, Al, Cd, NO3-N and NH4-N were measured during spring, summer and winter in the centers, edges and troughs of four polygons in each of four areas of contrasting moisture regime and polygon type. In 2013, probes were installed in centers, edges and troughs of four polygons in each of two areas (high-centered and low-centered polygons) at two-week intervals and at 3 soil depths to capture fine-scale season dynamics of NO3-N and NH4-N. PRS probes are ion exchange resin membranes held in plastic supports that are inserted into soil to measure ion supply in situ. The anion and cation exchange with the membrane is intended to mimic plant uptake and thus provide a relevant measure of soil nutrient bioavailability. Measurements are made per area of probe membrane and cannot be converted to concentrations or related to soil volume.

A Real-Time Method for Estimating Viscous Forebody Drag Coefficients

NASA Technical Reports Server (NTRS)

Whitmore, Stephen A.; Hurtado, Marco; Rivera, Jose; Naughton, Jonathan W.

2000-01-01

This paper develops a real-time method based on the law of the wake for estimating forebody skin-friction coefficients. The incompressible law-of-the-wake equations are numerically integrated across the boundary layer depth to develop an engineering model that relates longitudinally averaged skin-friction coefficients to local boundary layer thickness. Solutions applicable to smooth surfaces with pressure gradients and rough surfaces with negligible pressure gradients are presented. Model accuracy is evaluated by comparing model predictions with previously measured flight data. This integral law procedure is beneficial in that skin-friction coefficients can be indirectly evaluated in real-time using a single boundary layer height measurement. In this concept a reference pitot probe is inserted into the flow, well above the anticipated maximum thickness of the local boundary layer. Another probe is servomechanism-driven and floats within the boundary layer. A controller regulates the position of the floating probe. The measured servomechanism position of this second probe provides an indirect measurement of both local and longitudinally averaged skin friction. Simulation results showing the performance of the control law for a noisy boundary layer are then presented.

In situ detection of a PCR-synthesized human pancentromeric DNA hybridization probe by color pigment immunostaining: application for dicentric assay automation.

PubMed

Kolanko, C J; Pyle, M D; Nath, J; Prasanna, P G; Loats, H; Blakely, W F

2000-03-01

We report a low cost and efficient method for synthesizing a human pancentromeric DNA probe by the polymerase chain reaction (PRC) and an optimized protocol for in situ detection using color pigment immunostaining. The DNA template used in the PCR was a 2.4 kb insert containing human alphoid repeated sequences of pancentromeric DNA subcloned into pUC9 (Miller et al. 1988) and the primers hybridized to internal sequences of the 172 bp consensus tandem repeat associated with human centromeres. PCR was performed in the presence of biotin-11-dUTP, and the product was used for in situ hybridization to detect the pancentromeric region of human chromosomes in metaphase spreads. Detection of pancentromeric probe was achieved by immunoenzymatic color pigment painting to yield a permanent image detected at high resolution by bright field microscopy. The ability to synthesize the centromeric probe rapidly and to detect it with color pigment immunostaining will lead to enhanced identification and eventually to automation of various chromosome aberration assays.

Dextran as a fast resorbable and mechanically stiff coating for flexible neural probes

NASA Astrophysics Data System (ADS)

Kil, D.; Brancato, L.; Puers, R.

2017-11-01

In this paper we report on the use of dextran as a temporary, fast dissolving stiff coating for flexible neural probes. Although polymer-based neural implants offer several advantages, compared to their rigid silicon counterparts, they pose significant challenges during implantation. Due to their extreme flexibility, they have the tendency to buckle under the axial load applied during insertion. The structural stiffness of the implants can be temporarily increased by applying a bioresorbable dextran coating which eases the penetration of neural tissue. For this application three types of dextran with different molecular weights are analysed. The dissolution rate of the coatings is reported as well as the increased bending stiffness resulting from the dextran coating of Parylene C neural probes. Based on these findings the dissolution rate can be linked to parameters such as molecular weight, coating thickness and the surface area exposed to the dissolution medium. The mechanical characterization yields information on how the structural stiffness of neural probes can be tuned by varying the dextran’s molecular weight and coating thickness.

Technical note: Computer-manufactured inserts for prosthetic sockets.

PubMed

Sanders, Joan E; McLean, Jake B; Cagle, John C; Gardner, David W; Allyn, Katheryn J

2016-08-01

The objective of this research was to use computer-aided design software and a tabletop 3-D additive manufacturing system to design and fabricate custom plastic inserts for trans-tibial prosthesis users. Shape quality of inserts was tested right after they were inserted into participant's test sockets and again after four weeks of wear. Inserts remained properly positioned and intact throughout testing. Right after insertion the inserts caused the socket to be slightly under-sized, by a mean of 0.11mm, approximately 55% of the thickness of a nylon sheath. After four weeks of wear the under-sizing was less, averaging 0.03mm, approximately 15% of the thickness of a nylon sheath. Thus the inserts settled into the sockets over time. If existing prosthetic design software packages were enhanced to conduct insert design and to automatically generate fabrication files for manufacturing, then computer manufactured inserts may offer advantages over traditional methods in terms of speed of fabrication, ease of design, modification, and record keeping. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Molecular cloning of cDNAs for the nerve-cell specific phosphoprotein, synapsin I.

PubMed Central

Kilimann, M W; DeGennaro, L J

1985-01-01

To provide access to synapsin I-specific DNA sequences, we have constructed cDNA clones complementary to synapsin I mRNA isolated from rat brain. Synapsin I mRNA was specifically enriched by immunoadsorption of polysomes prepared from the brains of 10-14 day old rats. Employing this enriched mRNA, a cDNA library was constructed in pBR322 and screened by differential colony hybridization with single-stranded cDNA probes made from synapsin I mRNA and total polysomal poly(A)+ RNA. This screening procedure proved to be highly selective. Five independent recombinant plasmids which exhibited distinctly stronger hybridization with the synapsin I probe were characterized further by restriction mapping. All of the cDNA inserts gave restriction enzyme digestion patterns which could be aligned. In addition, some of the cDNA inserts were shown to contain poly(dA) sequences. Final identification of synapsin I cDNA clones relied on the ability of the cDNA inserts to hybridize specifically to synapsin I mRNA. Several plasmids were tested by positive hybridization selection. They specifically selected synapsin I mRNA which was identified by in vitro translation and immunoprecipitation of the translation products. The established cDNA clones were used for a blot-hybridization analysis of synapsin I mRNA. A fragment (1600 bases) from the longest cDNA clone hybridized with two discrete RNA species 5800 and 4500 bases long, in polyadenylated RNA from rat brain and PC12 cells. No hybridization was detected to RNA from rat liver, skeletal muscle or cardiac muscle. Images Fig. 1. Fig. 2. Fig. 4. Fig. 5. PMID:3933975

Probing the Failure Mechanism of SnO2 Nanowires for Sodium-ion Batteries

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

Gu, Meng; Kushima, Akihiro; Shao, Yuyan

2013-09-30

Non-lithium metals such as sodium have attracted wide attention as a potential charge carrying ion for rechargeable batteries, performing the same role as lithium in lithium- ion batteries. As sodium and lithium have the same +1 charge, it is assumed that what has been learnt about the operation of lithium ion batteries can be transferred directly to sodium batteries. Using in-situ TEM, in combination with DFT calculations, we probed the structural and chemical evolution of SnO2 nanowire anodes in Na-ion batteries and compared them quantitatively with results from Li-ion batteries [Science 330 (2010) 1515]. Upon Na insertion into SnO2, amore » displacement reaction occurs, leading to the formation of amorphous NaxSn nanoparticles covered by crystalline Na2O shell. With further Na insertion, the NaxSn core crystallized into Na15Sn4 (x=3.75). Upon extraction of Na (desodiation), the NaxSn core transforms to Sn nanoparticles. Associated with a volume shrinkage, nanopores appear and metallic Sn particles are confined in hollow shells of Na2O, mimicking a peapod structure. These pores greatly increase electrical impedance, therefore naturally accounting for the poor cyclability of SnO2. DFT calculations indicate that Na+ diffuses 30 times slower than Li+ in SnO2, in agreement with in-situ TEM measurement. Insertion of Na can chemo-mechanically soften the reaction product to greater extent than in lithiation. Therefore, in contrast to the lithiation of SnO2, no dislocation plasticity was seen ahead of the sodiation front. This direct comparison of the results from Na and Li highlights the critical role of ionic size and electronic structure of different ionic species on the charge/discharge rate and failure mechanisms in these batteries.« less

Microstructure evolution of the Ir-inserted Ni silicides with additional annealing

NASA Astrophysics Data System (ADS)

Yoon, Kijeong; Song, Ohsung

2009-02-01

Thermally-evaporated 10 nm-Ni/1 nm-Ir/(poly)Si structures were fabricated in order to investigate the thermal stability of Ir-inserted nickel silicide after additional annealing. The silicide samples underwent rapid thermal annealing at 300 ° C to 1200 ° C for 40 s, followed by 30 min annealing at the given RTA temperatures. Silicides suitable for the salicide process were formed on the top of the single crystal and polycrystalline silicon substrates, mimicking actives and gates. The sheet resistance was measured using a four-point probe. High resolution x-ray diffraction and Auger depth profiling were used for phase and chemical composition analysis, respectively. Transmission electron microscope and scanning probe microscope were used to determine the cross-section structure and surface roughness. The silicide, which formed on single crystal silicon substrate with surface agglomeration after additional annealing, could defer the transformation of Ni(Ir)Si to Ni(Ir)Si2 and was stable at temperatures up to 1200 °C. Moreover, the silicide thickness doubled. There were no outstanding changes in the silicide thickness on polycrystalline silicon. However, after additional annealing, the silicon-silicide mixing became serious and showed high resistance at temperatures >700 °C. Auger depth profiling confirmed the increased thickness of the silicide layers after additional annealing without a change in composition. For a single crystal silicon substrate, the sheet resistance increased slightly due to the significant increases in surface roughness caused by surface agglomeration after additional annealing. Otherwise, there were almost no changes in surface roughness on the polycrystalline silicon substrate. The Ir-inserted nickel monosilicide was able to maintain a low resistance in a wide temperature range and is considered suitable for the nano-thick silicide process.

Probing the Li Insertion Mechanism of ZnFe 2O 4 in Li-Ion Batteries: A Combined X-Ray Diffraction, Extended X-Ray Absorption Fine Structure, and Density Functional Theory Study [Probing the Li insertion mechanism of ZnFe 2O 4 in Li ion batteries: A combined XRD, EXAFS, and DFT study

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

Zhang, Yiman; Pelliccione, Christopher J.; Brady, Alexander B.

Here, we report an extensive study on fundamental properties that determine the functional electrochemistry of ZnFe 2O 4 spinel (theoretical capacity of 1000 mAh/g). For the first time, the reduction mechanism is followed through a combination of in situ X-ray diffraction data, synchrotron based powder diffraction, and ex-situ extended X-ray absorption fine structure allowing complete visualization of reduction products irrespective of their crystallinity. The first 0.5 electron equivalents (ee) do not significantly change the starting crystal structure. Subsequent lithiation results in migration of Zn 2+ ions from 8a tetrahedral sites into vacant 16c sites. Density functional theory shows that Limore » + ions insert into 16c site initially and then 8a site with further lithiation. Fe metal is formed over the next eight ee of reduction with no evidence of concurrent Zn 2+ reduction to Zn metal. Despite the expected formation of LiZn alloy from the electron count, we find no evidence for this phase under the tested conditions. Additionally, upon oxidation to 3 V, we observe an FeO phase with no evidence of Fe 2O 3. Electrochemistry data show higher electron equivalent transfer than can be accounted for solely based on ZnFe 2O 4 reduction indicating excess capacity ascribed to carbon reduction or surface electrolyte interphase formation.« less

The influence of removable partial dentures on the periodontal health of abutment and non-abutment teeth

PubMed Central

Dula, Linda J.; Shala, Kujtim Sh.; Pustina–Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F.

2015-01-01

Objective: The aim of this study was to evaluate the influence of removable partial dentures (RPD) on the periodontal health of abutment and non-abutment teeth. Materials and Methods: A total 107 patients with RPD participated in this study. It was examined 138 RPD, they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth, plaque index (PLI), calculus index (CI), bleeding on probing (BOP), probing depth (PD) (mm) and tooth mobility (TM) index. These clinical measurements were taken immediately before insertion the RPD, then one and 3 months after insertion. The level of significance was set at (P < 0.05). Results: The mean scores for PLI, CI, BOP, PD, and TM index, of the abutment teeth and non-abutment teeth were no statistically significant at the time of insertion of RPD. After 1-month, PLI was statistically significant (0.57 ± 0.55 for abutment and 0.30 ± 0.46 for non-abutment teeth). After 3 months, there were significant differences between abutment and non-abutment teeth with regard to the BOP (1.53 ± 0.50 and 1.76 ± 0.43 respectively), PD (0.28 ± 0.45 and 0.12 ± 0.33 respectively) and PLI (1.20 ± 0.46 and 0.75 ± 0.64 respectively). No significant mean difference in TM and CI was found between the abutment and non-abutment teeth (P > 0.05). Conclusions: With carefully planned prosthetic treatment and adequate maintenance of the oral and denture hygiene, we can prevent the periodontal diseases. PMID:26430367

Probing the Li Insertion Mechanism of ZnFe 2O 4 in Li-Ion Batteries: A Combined X-Ray Diffraction, Extended X-Ray Absorption Fine Structure, and Density Functional Theory Study [Probing the Li insertion mechanism of ZnFe 2O 4 in Li ion batteries: A combined XRD, EXAFS, and DFT study

DOE PAGES

Zhang, Yiman; Pelliccione, Christopher J.; Brady, Alexander B.; ...

2017-04-24

Here, we report an extensive study on fundamental properties that determine the functional electrochemistry of ZnFe 2O 4 spinel (theoretical capacity of 1000 mAh/g). For the first time, the reduction mechanism is followed through a combination of in situ X-ray diffraction data, synchrotron based powder diffraction, and ex-situ extended X-ray absorption fine structure allowing complete visualization of reduction products irrespective of their crystallinity. The first 0.5 electron equivalents (ee) do not significantly change the starting crystal structure. Subsequent lithiation results in migration of Zn 2+ ions from 8a tetrahedral sites into vacant 16c sites. Density functional theory shows that Limore » + ions insert into 16c site initially and then 8a site with further lithiation. Fe metal is formed over the next eight ee of reduction with no evidence of concurrent Zn 2+ reduction to Zn metal. Despite the expected formation of LiZn alloy from the electron count, we find no evidence for this phase under the tested conditions. Additionally, upon oxidation to 3 V, we observe an FeO phase with no evidence of Fe 2O 3. Electrochemistry data show higher electron equivalent transfer than can be accounted for solely based on ZnFe 2O 4 reduction indicating excess capacity ascribed to carbon reduction or surface electrolyte interphase formation.« less

Transesophageal echocardiography in critically ill acute postoperative infants: comparison of AcuNav intracardiac echocardiographic and microTEE miniaturized transducers.

PubMed

Ferns, Sunita; Komarlu, Rukmini; Van Bergen, Andrew; Multani, Kanwar; Cui, Vivian Wei; Roberson, David A

2012-08-01

Multiple barriers to transthoracic echocardiography are present in critically ill infants immediately after surgery. Transesophageal echocardiography (TEE) is sometimes needed to obtain specific important information that transthoracic echocardiography fails to demonstrate. Formerly, the investigators used the AcuNav intracardiac echocardiographic (ICE) intravascular ultrasound transducer (8 Fr, 2.5 mm, 64-element crystal array, multifrequency [5.5-10 MHz], single longitudinal plane, linear phased array [Siemens Medical Solutions USA, Inc., Mountain View, CA]). Recently, the investigators have also used the microTEE transducer (8-mm transducer tip, 5.2-mm shaft, multifrequency [3-8 MHz], multiplane phased array, 32-element probe [Philips Medical Systems, Andover, MA]). Both transducers have two-dimensional, M-mode, color Doppler, and pulsed-wave and continuous-wave Doppler capabilities. The aim of this study was to compare the efficacy, safety, ease of insertion, capabilities, utilization, and cost of the AcuNav ICE transducer versus those of the microTEE transducer. A retrospective review of all 50 postoperative critically ill infants who underwent TEE using the AcuNav and microTEE in the past 5 years was conducted. TEE was performed as ordered by the attending physician to answer a specific question not answered by transthoracic echocardiography. In all cases, the clinical information sought was obtained. The AcuNav ICE transducer was safe, easy to insert through the transnasal route, and did not require paralysis; however, it had a limited number of echocardiographic views and had greater sterilization cost. The microTEE transducer had greater echocardiographic capabilities and lower sterilization cost; however, it was slightly more difficult to insert, had a few manageable complications, and required more sedation and paralysis. TEE in this setting has increased because of demonstrated efficacy and safety. Both the AcuNav ICE and microTEE transducers are useful and effective in this critical clinical scenario. Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Theoretical analysis of a dual-probe scanning tunneling microscope setup on graphene.

PubMed

Settnes, Mikkel; Power, Stephen R; Petersen, Dirch H; Jauho, Antti-Pekka

2014-03-07

Experimental advances allow for the inclusion of multiple probes to measure the transport properties of a sample surface. We develop a theory of dual-probe scanning tunneling microscopy using a Green's function formalism, and apply it to graphene. Sampling the local conduction properties at finite length scales yields real space conductance maps which show anisotropy for pristine graphene systems and quantum interference effects in the presence of isolated impurities. Spectral signatures in the Fourier transforms of real space conductance maps include characteristics that can be related to different scattering processes. We compute the conductance maps of graphene systems with different edge geometries or height fluctuations to determine the effects of nonideal graphene samples on dual-probe measurements.

Tensiometer methods and apparatus

DOEpatents

Grover, Blair K.; Hubbell, Joel M.; Sisson, James B.; Casper, William L.

2004-08-10

A method for collecting data regarding a matric potential of a media includes providing a tensiometer having a stainless steel tensiometer casing, the stainless steel tensiometer casing comprising a tip portion which includes a wetted porous stainless steel membrane through which a matric potential of a media is sensed; driving the tensiometer into the media using an insertion tube comprising a plurality of probe casing which are selectively coupled to form the insertion tube as the tensiometer is progressively driven deeper into the media, wherein the wetted porous stainless steel membrane is in contact with the media; and sensing the matric potential the media exerts on the wetted porous stainless steel membrane by a pressure sensor in fluid hydraulic connection with the porous stainless steel membrane. A tensiometer includes a stainless steel casing.

Protein-Backbone Thermodynamics across the Membrane Interface.

PubMed

Bereau, Tristan; Kremer, Kurt

2016-07-07

The thermodynamics of insertion of a protein in a membrane depends on the fine interplay between backbone and side-chain contributions interacting with the lipid environment. Using computer simulations, we probe how different descriptions of the backbone glycyl unit affect the thermodynamics of insertion of individual residues, dipeptides, and entire transmembrane helices. Due to the lack of reference data, we first introduce an efficient methodology to estimate atomistic potential of mean force (PMF) curves from a series of representative and uncorrelated coarse-grained (CG) snapshots. We find strong discrepancies between two CG models, Martini and PLUM, against reference atomistic PMFs and experiments. Atomistic simulations suggest a weak free energy of insertion between water and a POPC membrane for the glycyl unit, in overall agreement with experimental results despite severe assumptions in our calculations. We show that refining the backbone contribution in PLUM significantly improves the PMF of insertion of the WALP16 transmembrane peptide. An improper balance between the glycyl backbone and the attached side chain will lead to energetic artifacts, rationalizing Martini's overstabilization of WALP's adsorbed interfacial state. It illustrates difficulties associated with free-energy-based parametrizations of single-residue models, as the relevant free energy of partitioning used for force-field parametrization does not arise from the entire residue but rather the solvent-accessible chemical groups.

Investigating the Mechanism of Reversible Lithium Insertion into Anti-NASICON Fe 2(WO 4) 3

DOE PAGES

Barim, Gozde; Cottingham, Patrick; Zhou, Shiliang; ...

2017-03-07

The gram-scale preparation of Fe 2(WO 4) 3 by a new solution-based route and detailed characterization of the material are presented. The resulting Fe 2(WO 4) 3 undergoes a reversible electrochemical reaction against lithium centered around 3.0 V with capacities near 93% of the theoretical maximum. Evolution of the Fe 2(WO 4) 3 structure upon lithium insertion and deinsertion is probed using a battery of characterization techniques, including in situ X-ray diffraction, neutron total scattering, and X-ray absorption spectroscopy (XAS). A structural transformation from monoclinic to orthorhombic phases is confirmed during lithium intercalation. XAS and neutron total scattering measurements verifymore » that Fe 2(WO 4) 3 consists of trivalent iron and hexavalent tungsten ions. As lithium ions are inserted into the framework, iron ions are reduced to the divalent state, while the tungsten ions are electrochemically inactive and remain in the hexavalent state. Lastly, lithium insertion occurs via a concerted rotation of the rigid polyhedra in the host lattice driven by electrostatic interactions with the Li + ions; the magnitude of these polyhedral rotations was found to be slightly larger for Fe 2(WO 4) 3 than for the Fe 2(MoO 4) 3 analog.« less

Investigating the Mechanism of Reversible Lithium Insertion into Anti-NASICON Fe 2(WO 4) 3

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

Barim, Gozde; Cottingham, Patrick; Zhou, Shiliang

The gram-scale preparation of Fe 2(WO 4) 3 by a new solution-based route and detailed characterization of the material are presented. The resulting Fe 2(WO 4) 3 undergoes a reversible electrochemical reaction against lithium centered around 3.0 V with capacities near 93% of the theoretical maximum. Evolution of the Fe 2(WO 4) 3 structure upon lithium insertion and deinsertion is probed using a battery of characterization techniques, including in situ X-ray diffraction, neutron total scattering, and X-ray absorption spectroscopy (XAS). A structural transformation from monoclinic to orthorhombic phases is confirmed during lithium intercalation. XAS and neutron total scattering measurements verifymore » that Fe 2(WO 4) 3 consists of trivalent iron and hexavalent tungsten ions. As lithium ions are inserted into the framework, iron ions are reduced to the divalent state, while the tungsten ions are electrochemically inactive and remain in the hexavalent state. Lastly, lithium insertion occurs via a concerted rotation of the rigid polyhedra in the host lattice driven by electrostatic interactions with the Li + ions; the magnitude of these polyhedral rotations was found to be slightly larger for Fe 2(WO 4) 3 than for the Fe 2(MoO 4) 3 analog.« less

Integrated Sensor Systems for UAS

DTIC Science & Technology

2008-04-01

2. Optical particle counter 0.27 5.4 3. Pyranometer 0.17 ɘ.2 4. Temp. & relative humidity 0.05 ɘ.1 5. Data acquisition system 0.15 ɘ.2 6...payload volume showing sensor instrument installation. The insert shows the Manta exterior with the cloud droplet probe and pyranometer mounted on...Instrumentation Above- 2.7 Aethalometer cloud 14 Optical particle counter Up and down pyranometers Condensation particle counter In- 3.7

Detection of discoloration and decay in living trees and utility poles

Treesearch

Alex L. Shigo; Alex Shigo

1974-01-01

A method is described for detecting discoloration and decay in living trees and creosoted utility poles. The method and devices have come from research involving many people over a seven-year period. A probe was inserted into a 3/32-inch (2.4 mm) diameter hole made by drill bits 8 inches (20.32 cm) and 12 inches (30.48 cm) long mounted in a portable, light-weight,...

Sparse sampling and reconstruction for electron and scanning probe microscope imaging

DOEpatents

Anderson, Hyrum; Helms, Jovana; Wheeler, Jason W.; Larson, Kurt W.; Rohrer, Brandon R.

2015-07-28

Systems and methods for conducting electron or scanning probe microscopy are provided herein. In a general embodiment, the systems and methods for conducting electron or scanning probe microscopy with an undersampled data set include: driving an electron beam or probe to scan across a sample and visit a subset of pixel locations of the sample that are randomly or pseudo-randomly designated; determining actual pixel locations on the sample that are visited by the electron beam or probe; and processing data collected by detectors from the visits of the electron beam or probe at the actual pixel locations and recovering a reconstructed image of the sample.

Development of Balanced SIS Mixers for ALMA Band-10

NASA Astrophysics Data System (ADS)

Shitov, Sergey V.; Koryukin, Oleg V.; Uzawa, Yoshinory; Noguchi, Takashi; Uvarov, Andrey V.; Cohn, Ilya A.

2006-05-01

A few concepts of a wide-band balanced SIS mixer employing submicron-sized SIS junctions are under development for 787-950 GHz frequency range. A quasioptical DSB balanced mixer with integrated cross-slot antenna is considered as the less laborious and cheaper option. The silicon lens-antenna beam efficiency is expected above 80 % across the whole band with first-order sidelobe below -16 dB. To use the conservative horn antenna solution, a single chamber waveguide DSB balanced mixer is developed. Two equal probe-type SIS chips are inserted into a full-height waveguide through its opposite broad walls; these two mixers are driven by the signal waveguide in series. The LO current is transferred to the mixers in parallel via a capacitive probe inserted through the narrow wall of the signal waveguide from the neighboring LO waveguide. The HFSS model demonstrated the LO power coupling efficiency above -3 dB, almost perfect signal transfer and the LO cross talk below -30 dB that take into account misalignment (misbalance) of the chips. It is demonstrated numerically using Tucker's 3-port model that unequal pump of junctions of a twin-SIS mixer can lead, in spite of the perfect signal coupling, to degradation of the gain performance up to -3 dB, especially at the top of the ALMA Band-10.

Photoacoustic imaging of prostate brachytherapy seeds with transurethral light delivery

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Guo, Xiaoyu; Song, Danny Y.; Boctor, Emad M.

2014-03-01

We present a novel approach to photoacoustic imaging of prostate brachytherapy seeds utilizing an existing urinary catheter for transurethral light delivery. Two canine prostates were surgically implanted with brachyther- apy seeds under transrectal ultrasound guidance. One prostate was excised shortly after euthanasia and fixed in gelatin. The second prostate was imaged in the native tissue environment shortly after euthanasia. A urinary catheter was inserted in the urethra of each prostate. A 1-mm core diameter optical fiber coupled to a 1064 nm Nd:YAG laser was inserted into the urinary catheter. Light from the fiber was either directed mostly parallel to the fiber axis (i.e. end-fire fire) or mostly 90° to the fiber axis (i.e. side-fire fiber). An Ultrasonix SonixTouch scanner, transrectal ultrasound probe with curvilinear (BPC8-4) and linear (BPL9-5) arrays, and DAQ unit were utilized for synchronized laser light emission and photoacoustic signal acquisition. The implanted brachytherapy seeds were visualized at radial distances of 6-16 mm from the catheter. Multiple brachytherapy seeds were si- multaneously visualized with each array of the transrectal probe using both delay-and-sum (DAS) and short-lag spatial coherence (SLSC) beamforming. This work is the first to demonstrate the feasibility of photoacoustic imaging of prostate brachytherapy seeds using a transurethral light delivery method.

Peripherally inserted central catheters. Guidewire versus nonguidewire use: a comparative study.

PubMed

Loughran, S C; Edwards, S; McClure, S

1992-01-01

To date, no research articles have been published that explore the practice of using guidewires for placement of peripherally inserted central catheters. The literature contains speculations regarding the pros and cons of guidewire use. However, no studies to date have compared patient outcomes when peripherally inserted central catheter lines are inserted with and without guidewires. To examine the use of guidewires for peripherally inserted central lines, a comparative study was conducted at two acute care facilities, one using guidewires for insertion and one inserting peripherally inserted central catheter lines without guidewires. 109 catheters were studied between January 1, 1990 and January 1, 1991. The primary focus of this study was to examine whether guidewire use places patients at higher risk for catheter-related complications, particularly phlebitis. No significant differences in phlebitis rates between the two study sites were found. Other catheter-related and noncatheter-related complications were similar between the two facilities. The results of this study do not support the belief that guidewire use increases complication rates.

Clinical tests of an ultrasonic periodontal probe

NASA Astrophysics Data System (ADS)

Hinders, Mark K.; Lynch, John E.; McCombs, Gayle B.

2002-05-01

A new ultrasonic periodontal probe has been developed that offers the potential for earlier detection of periodontal disease activity, non-invasive diagnosis, and greater reliability of measurement. A comparison study of the ultrasonic probe to both a manual probe, and a controlled-force probe was conducted to evaluate its clinical effectiveness. Twelve patients enrolled into this study. Two half-month examinations were conducted on each patient, scheduled one hour apart. A one-way analysis of variance was performed to compare the results for the three sets of probing depth measurements, followed by a repeated measures analysis to assess the reproducibility of the different probing techniques. These preliminary findings indicate that manual and ultrasonic probing measure different features of the pocket. Therefore, it is not obvious how the two depth measurements correspond to each other. However, both methods exhibited a similar tendency toward increasing pocket depths as Gingival Index scores increased. Based on the small sample size, further studies need to be conducted using a larger population of patients exhibiting a wider range of disease activity. In addition, studies that allow histological examination of the pocket after probing will help further evaluate the clinical effectiveness the ultrasonic probe. Future studies will also aid in the development of more effective automated feature recognition algorithms that convert the ultrasonic echoes into pocket depth readings.

Modelling of a laser-pumped light source for endoscopic surgery

NASA Astrophysics Data System (ADS)

Nadeau, Valerie J.; Elson, Daniel S.; Hanna, George B.; Neil, Mark A. A.

2008-09-01

A white light source, based on illumination of a yellow phosphor with a fibre-coupled blue-violet diode laser, has been designed and built for use in endoscopic surgery. This narrow light probe can be integrated into a standard laparoscope or inserted into the patient separately via a needle. We present a Monte Carlo model of light scattering and phosphorescence within the phosphor/silicone matrix at the probe tip, and measurements of the colour, intensity, and uniformity of the illumination. Images obtained under illumination with this light source are also presented, demonstrating the improvement in illumination quality over existing endoscopic light sources. This new approach to endoscopic lighting has the advantages of compact design, improved ergonomics, and more uniform illumination in comparison with current technologies.

Pressure generation during neural stimulation with infrared radiation

NASA Astrophysics Data System (ADS)

Xia, N.; Tan, X.; Xu, Y.; Richter, C.-P.

2017-02-01

This study quantifies laser evoked pressure waves in small confined volumes such as a small dish or the cochlea. The pressure was measured with custom fabricated pressure probes in front of the optical fiber. For the pressure measurements during laser stimulation the probes were inserted into scala tympani or vestibuli. At 164 μJ/pulse, the intracochlear pressure was between 96 and 106 dB (re 20 μPa). The pressure was also measured in the ear canal with a sensitive microphone. It was on average 63 dB (re 20 μPa). At radiant energies large enough to evoke an auditory compound action potential, the outer ear canal equivalent pressure was 36-56 dB (re 20 μPa).

Direct Electrospray Ionization Mass Spectrometric Profiling of Real-World Samples via a Solid Sampling Probe

NASA Astrophysics Data System (ADS)

Yu, Zhan; Chen, Lee Chuin; Mandal, Mridul Kanti; Yoshimura, Kentaro; Takeda, Sen; Hiraoka, Kenzo

2013-10-01

This study presents a novel direct analysis strategy for rapid mass spectrometric profiling of biochemicals in real-world samples via a direct sampling probe (DSP) without sample pretreatments. Chemical modification is applied to a disposable stainless steel acupuncture needle to enhance its surface area and hydrophilicity. After insertion into real-world samples, biofluid can be attached on the DSP surface. With the presence of a high DC voltage and solvent vapor condensing on the tip of the DSP, analyte can be dissolved and electrosprayed. The simplicity in design, versatility in application aspects, and other advantages such as low cost and disposability make this new method a competitive tool for direct analysis of real-world samples.

Liquid fuel vaporizer and combustion chamber having an adjustable thermal conductor

DOEpatents

Powell, Michael R; Whyatt, Greg A; Howe, Daniel T; Fountain, Matthew S

2014-03-04

The efficiency and effectiveness of apparatuses for vaporizing and combusting liquid fuel can be improved using thermal conductors. For example, an apparatus having a liquid fuel vaporizer and a combustion chamber can be characterized by a thermal conductor that conducts heat from the combustion chamber to the vaporizer. The thermal conductor can be a movable member positioned at an insertion depth within the combustion chamber that corresponds to a rate of heat conduction from the combustion chamber to the vaporizer. The rate of heat conduction can, therefore, be adjusted by positioning the movable member at a different insertion depth.

Identification of neonatal hearing impairment: ear-canal measurements of acoustic admittance and reflectance in neonates.

PubMed

Keefe, D H; Folsom, R C; Gorga, M P; Vohr, B R; Bulen, J C; Norton, S J

2000-10-01

1) To describe broad bandwidth measurements of acoustic admittance (Y) and energy reflectance (R) in the ear canals of neonates. 2) To describe a means for evaluating when a YR response is valid. 3) To describe the relations between these YR measurements and age, gender, left/right ear, and selected risk factors. YR responses were obtained at four test sites in well babies without risk indicators, well babies with at least one risk indicator, and graduates of neonatal intensive care units. YR responses were measured using a chirp stimulus at moderate levels over a frequency range from 250 to 8000 Hz. The system was calibrated based on measurements in a set of cylindrical tubes. The probe assembly was inserted in the ear canal of the neonate, and customized software was used for data acquisition. YR responses were measured in over 4000 ears, and half of the responses were used in exploratory data analyses. The particular YR variables chosen for analysis were energy reflectance, equivalent volume and acoustic conductance. Based on the view that unduly large negative equivalent volumes at low frequencies were physically impossible, it was concluded that approximately 13% of the YR responses showed evidence of improper probe seal in the ear canal. To test how these outliers influenced the overall pattern of YR responses, analyses were conducted both on the full data set (N = 2081) and the data set excluding outliers (N = 1825). The YR responses averaged over frequency varied with conceptional age (conception to date of test), gender, left/right ear, and selected risk factors; in all cases, significant effects were observed more frequently in the data set excluding outliers. After excluding outliers and controlling for conceptional age effects, the dichotomous risk factors accounting for the greatest variance in the YR responses were, in rank order, cleft lip and palate, aminoglycoside therapy, low birth weight, history of ventilation, and low APGAR scores. In separate analyses, YR responses varied in the first few days after birth. An analysis showed that the use of a YR test criterion to assess the quality of probe seal may help control the false-positive rate in evoked otoacoustic emission testing. This is the first report of wideband YR responses in neonates. Data were acquired in a few seconds, but the responses are highly sensitive to whether the probe is fully sealed in the ear canal. A real-time acoustic test of probe fit is proposed to better address the probe seal problem. The YR responses provide information on middle-ear status that varies over the neonatal age range and that is sensitive to the presence or absence of risk factors, ear, and gender differences. Thus, a YR test may have potential for use in neonatal screening tests for hearing loss.

Comparison of marginal bleeding using a periodontal probe or an interdental brush as indicators of gingivitis.

PubMed

Hofer, D; Sahrmann, P; Attin, T; Schmidlin, P R

2011-08-01

To compare the use of interdental brushes to a periodontal probe in assessing marginal bleeding, in natural gingivitis. Sixty-four consecutive volunteers presenting with gingival inflammation were recruited at their semi-annual recall appointments for this study. All had ≥50% papillary height and no pocketing that exceeded 4 mm. Contra-lateral quadrants (1 & 3 or 2 & 4) were randomly tested for bleeding with one pass-through with an interdental brush or with a periodontal probe inserted 2 mm into the gingival sulcus. The presence or absence of both bleeding and plaque were then recorded. Correlation coefficients were calculated for the interdental brushes and the periodontal probe, and the plaque and bleeding scores. The periodontal probe and the interdental brushes showed mean average bleeding scores of 47.39% and 45.74% respectively. The correlation coefficient for the two methods was 0.73 (P < 0.0001). No correlation between plaque and bleeding was found. Interdental brushes can be considered a valid alternative to a periodontal probe in assessing marginal bleeding in gingivitis patients. An interdental brush, sized correctly for each interdental space, is easy to handle, atraumatic to the papillae and will allow gingivitis patients to monitor their own progress, while at the same time performing a beneficial oral hygiene procedure and removing any interdental plaque present. © 2010 John Wiley & Sons A/S.

Electric field measurement in microwave discharge ion thruster with electro-optic probe.

PubMed

Ise, Toshiyuki; Tsukizaki, Ryudo; Togo, Hiroyoshi; Koizumi, Hiroyuki; Kuninaka, Hitoshi

2012-12-01

In order to understand the internal phenomena in a microwave discharge ion thruster, it is important to measure the distribution of the microwave electric field inside the discharge chamber, which is directly related to the plasma production. In this study, we proposed a novel method of measuring a microwave electric field with an electro-optic (EO) probe based on the Pockels effect. The probe, including a cooling system, contains no metal and can be accessed in the discharge chamber with less disruption to the microwave distribution. This method enables measurement of the electric field profile under ion beam acceleration. We first verified the measurement with the EO probe by a comparison with a finite-difference time domain numerical simulation of the microwave electric field in atmosphere. Second, we showed that the deviations of the reflected microwave power and the beam current were less than 8% due to inserting the EO probe into the ion thruster under ion beam acceleration. Finally, we successfully demonstrated the measurement of the electric-field profile in the ion thruster under ion beam acceleration. These measurements show that the electric field distribution in the thruster dramatically changes in the ion thruster under ion beam acceleration as the propellant mass flow rate increases. These results indicate that this new method using an EO probe can provide a useful guide for improving the propulsion of microwave discharge ion thrusters.

A multi-channel capacitive probe for electrostatic fluctuation measurement in the Madison Symmetric Torus reversed field pinch.

PubMed

Tan, Mingsheng; Stone, Douglas R; Triana, Joseph C; Almagri, Abdulgader F; Fiksel, Gennady; Ding, Weixing; Sarff, John S; McCollam, Karsten J; Li, Hong; Liu, Wandong

2017-02-01

A 40-channel capacitive probe has been developed to measure the electrostatic fluctuations associated with the tearing modes deep into Madison Symmetric Torus (MST) reversed field pinch plasma. The capacitive probe measures the ac component of the plasma potential via the voltage induced on stainless steel electrodes capacitively coupled with the plasma through a thin annular layer of boron nitride (BN) dielectric (also serves as the particle shield). When bombarded by the plasma electrons, BN provides a sufficiently large secondary electron emission for the induced voltage to be very close to the plasma potential. The probe consists of four stalks each with ten cylindrical capacitors that are radially separated by 1.5 cm. The four stalks are arranged on a 1.3 cm square grid so that at each radial position, there are four electrodes forming a square grid. Every two adjacent radial sets of four electrodes form a cube. The fluctuating electric field can be calculated by the gradient of the plasma potential fluctuations at the eight corners of the cube. The probe can be inserted up to 15 cm (r/a = 0.7) into the plasma. The capacitive probe has a frequency bandwidth from 13 Hz to 100 kHz, amplifier-circuit limit, sufficient for studying the tearing modes (5-30 kHz) in the MST reversed-field pinch.

Flexible probe for measuring local conductivity variations in Li-ion electrode films

NASA Astrophysics Data System (ADS)

Hardy, Emilee; Clement, Derek; Vogel, John; Wheeler, Dean; Mazzeo, Brian

2018-04-01

Li-ion battery performance is governed by electronic and ionic properties of the battery. A key metric that characterizes Li-ion battery cell performance is the electronic conductivity of the electrodes, which are metal foils with thin coatings of electrochemically active materials. To accurately measure the spatial variation of electronic conductivity of these electrodes, a micro-four-line probe (μ4LP) was designed and used to non-destructively measure the properties of commercial-quality Li-ion battery films. This previous research established that the electronic conductivity of film electrodes is not homogeneous throughout the entirety of the deposited film area. In this work, a micro-N-line probe (μNLP) and a flexible micro-flex-line probe (μFLP) were developed to improve the non-destructive micro-scale conductivity measurements that we can take. These devices were validated by comparing test results to that of the predecessor, the micro-four-line probe (μ4LP), on various commercial-quality Li-ion battery electrodes. Results show that there is significant variation in conductivity on a millimeter and even micrometer length scale through the electrode film. Compared to the μ4LP, the μNLP and μFLP also introduce additional measurement configuration possibilities, while providing a more robust design. Researchers and manufacturers can use these probes to identify heterogeneity in their electrodes during the fabrication process, which will lead to the development of better batteries.

Mercury ion thruster research, 1978

NASA Technical Reports Server (NTRS)

Wilbur, P. J.

1978-01-01

The effects of 8 cm thruster main and neutralizer cathode operating conditions on cathode orifice plate temperatures were studied. The effects of cathode operating conditions on insert temperature profiles and keeper voltages are presented for three different types of inserts. The bulk of the emission current is generally observed to come from the downstream end of the insert rather than from the cathode orifice plate. Results of a test in which the screen grid plasma sheath of a thruster was probed as the beam current was varied are shown. Grid performance obtained with a grid machined from glass ceramic is discussed. The effects of copper and nitrogen impurities on the sputtering rates of thruster materials are measured experimentally and a model describing the rate of nitrogen chemisorption on materials in either the beam or the discharge chamber is presented. The results of optimization of a radial field thruster design are presented. Performance of this device is shown to be comparable to that of a divergent field thruster and efficient operation with the screen grid biased to floating potential, where its susceptibility to sputter erosion damage is reduced, is demonstrated.

Structure of Carbon Nanotube Porins in Lipid Bilayers: An in Situ Small-Angle X-ray Scattering (SAXS) Study [Atomic-level structure of carbon nanotube porins in lipid bilayers: an in-situ small-angle x-ray scattering (SAXS) study

DOE PAGES

Tran, Ich C.; Tunuguntla, Ramya H.; Kim, Kyunghoon; ...

2016-06-20

Carbon nanotube porins (CNTPs), small segments of carbon nanotubes capable of forming defined pores in lipid membranes, are important future components for bionanoelectronic devices as they could provide a robust analog of biological membrane channels. Furthermore, in order to control the incorporation of these CNT channels into lipid bilayers, it is important to understand the structure of the CNTPs before and after insertion into the lipid bilayer as well as the impact of such insertion on the bilayer structure. Here we employed a noninvasive in situ probe, small-angle X-ray scattering, to study the integration of CNT porins into dioleoylphosphatidylcholine bilayers.more » These results show that CNTPs in solution are stabilized by a monolayer of lipid molecules wrapped around their outer surface. We also demonstrate that insertion of CNTPs into the lipid bilayer results in decreased bilayer thickness with the magnitude of this effect increasing with the concentration of CNTPs.« less

Method And Apparatus For Two Dimensional Surface Property Analysis Based On Boundary Measurement

DOEpatents

Richardson, John G.

2005-11-15

An apparatus and method for determining properties of a conductive film is disclosed. A plurality of probe locations selected around a periphery of the conductive film define a plurality of measurement lines between each probe location and all other probe locations. Electrical resistance may be measured along each of the measurement lines. A lumped parameter model may be developed based on the measured values of electrical resistance. The lumped parameter model may be used to estimate resistivity at one or more selected locations encompassed by the plurality of probe locations. The resistivity may be extrapolated to other physical properties if the conductive film includes a correlation between resistivity and the other physical properties. A profile of the conductive film may be developed by determining resistivity at a plurality of locations. The conductive film may be applied to a structure such that resistivity may be estimated and profiled for the structure's surface.

Optimizing the performance of neural interface devices with hybrid poly(3,4-ethylene dioxythiophene) (PEDOT)

NASA Astrophysics Data System (ADS)

Kuo, Chin-chen

This thesis describes methods for improving the performance of poly(3,4-ethylenedioxythiophene) (PEDOT) as a direct neural interfacing material. The chronic foreign body response is always a challenge for implanted bionic devices. After long-term implantation (typically 2-4 weeks), insulating glial scars form around the devices, inhibiting signal transmission, which ultimately leads to device failure. The mechanical mismatch at the device-tissue interface is one of the issues that has been associated with chronic foreign body response. Another challenge for using PEDOT as a neural interface material is its mechanical failure after implantation. We observed cracking and delamination of PEDOT coatings on devices after extended implantations. In the first part of this thesis, we present a novel method for directly measuring the mechanical properties of a PEDOT thin film. Before investigating methods to improve the mechanical behavior of PEDOT, a comprehensive understanding of the mechanical properties of PEDOT thin film is required. A PEDOT thin film was machined into a dog-bone shape specimen with a dual beam FIB-SEM. With an OmniProbe, this PEDOT specimen could be attached onto a force sensor, while the other side was attached to OmniProbe. By moving the OmniProbe, the specimen could be deformed in tension, and a force sensor recorded the applied load on the sample simultaneously. Mechanical tensile tests were conducted in the FIB-SEM chamber along with in situ observation. With precise force measurement from the force sensor and the corresponding high resolution SEM images, we were able to convert the data to a stress-strain curve for further analysis. By analyzing these stress-strain curves, we were able to obtain information about PEDOT including the Young's modulus, strength of failure, strain to failure, and toughness (energy to failure). This information should be useful for future material selection and molecular design for specific applications. The second section of this thesis is mainly focused on developing a soft and conductive material by in situ PEDOT polymerization into soft matrix. First, PEDOT was in situ polymerized into extracellular matrix (ECM) as a conductive, soft, and bioactive material for neural interfacing. ECM is basically a matrix of proteins which provides biological cues with the potential to promote neural attachment. We modified the electrode to a needle shape, which could be inserted into the ECM film. The limited surface area on the electrode and the close contact with ECM made it possible to polymerize PEDOT into the ECM more easily. The conductivity of PEDOT-ECM was confirmed to be similar to intrinsic PEDOT. A cell adhesion test using the PC12 cell line was used to evaluate its biocompatibility. PEDOT-ECM shows improved cell adhesion for PC12 cells, as compared either bare metal electrodes or PEDOT coated surfaces. In the future this approach may be elevated to an " autologous" concept, where the ECM could be derived from the host patients themselves to further reduce the foreign body response. Second, low modulus hydrogels were used as templates for PEDOT polymerization. EDOT monomers were premixed into agarose hydrogels. The electrochemical polymerization was typically conducted in potentiostatic (constant voltage) mode with working voltage of 2 V. After 0.8 C/cm2 charge density, a significant dark blue cloud was observed indicating that PEDOT was in situ polymerized into hydrogel matrix. A series of studies was conducted to confirm the improved mechanical properties, electrical properties and biocompatibility of the PEDOT-gel as compared to the typical solid PEDOT. Animal studies were conducted to evaluate the performance of PEDOT-gel coated electrode in vivo. Rats were used as the animal model with 3 rats in each group of bare electrode, PEDOT-coated, and PEDOT-gel coated electrode (n=9). The in vivo impedance was used to confirm the performance of the implanted electrodes. The results showed that the impedance had a significant increase after 4 weeks with the bare and solid PEDOT-coated electrode. This is consistent with the typical glial scar encapsulation around the electrode leading to an impedance increase. PEDOT-gel presents consistently low impedance along with 10 weeks implantation implying there was much less reactive response around the insertion site. These in vivo experiments on PEDOT-gels suggest that PEDOT-gels are promising neural interfacing materials for patients clinically.

Non-invasive estimation of middle-ear input impedance and efficiency.

PubMed

Lewis, James D; Neely, Stephen T

2015-08-01

A method to transform the impedance measured in the ear canal, ZEC, to the plane of the eardrum, ZED, is described. The portion of the canal between the probe and eardrum was modeled as a concatenated series of conical segments, allowing for spatial variations in its cross-sectional area. A model of the middle ear (ME) and cochlea terminated the ear-canal model, which permitted estimation of ME efficiency. Acoustic measurements of ZEC were made at two probe locations in 15 normal-hearing subjects. ZEC was sensitive to measurement location, especially near frequencies of canal resonances and anti-resonances. Transforming ZEC to ZED reduced the influence of the canal, decreasing insertion-depth sensitivity of ZED between 1 and 12 kHz compared to ZEC. Absorbance, A, was less sensitive to probe placement than ZEC, but more sensitive than ZED above 5 kHz. ZED and A were similarly insensitive to probe placement between 1 and 5 kHz. The probe-placement sensitivity of ZED below 1 kHz was not reduced from that of either A or ZEC. ME efficiency had a bandpass shape with greatest efficiency between 1 and 4 kHz. Estimates of ZED and ME efficiency could extend the diagnostic capability of wideband-acoustic immittance measurements.

Fiber optics spectrochemical emission sensors

DOEpatents

Griffin, Jeffrey W.; Olsen, Khris B.

1992-01-01

A method of in situ monitoring of a body of a fluid stored in a tank or groundwater or vadose zone gases in a well for the presence of selected chemical species uses a probe insertable into the well or tank via a cable and having electrical apparatus for exciting selected chemical species in the body of fluid. The probe can have a pair of electrodes for initiating a spark or a plasma cell for maintaining a plasma to excite the selected chemical species. The probe also has optical apparatus for receiving optical emissions emitted by the excited species and optically transmitting the emissions via the cable to an analysis location outside the well. The analysis includes detecting a selected wavelength in the emissions indicative of the presence of the selected chemical species. A plurality of probes can be suspended at an end of a respective cable, with the transmitting and analyzing steps for each probe being synchronized sequentially for one set of support equipment and instrumentation to monitor at multiple test points. The optical apparatus is arranged about the light guide axis so that the selected chemical species are excited the fluid in alignment with the light guide axis and optical emissions are received from the excited chemical species along such axis.

Fiber optics spectrochemical emission sensors

DOEpatents

Griffin, J.W.; Olsen, K.B.

1992-02-04

A method is described of in situ monitoring of a body of a fluid stored in a tank or groundwater or vadose zone gases in a well for the presence of selected chemical species. The method uses a probe insertable into the well or tank via a cable and having an electrical apparatus for exciting selected chemical species in the body of fluid. The probe can have a pair of electrodes for initiating a spark or a plasma cell for maintaining a plasma to excite the selected chemical species. The probe also has an optical apparatus for receiving optical emissions emitted by the excited species and optically transmitting the emissions via the cable to an analysis location outside the well. The analysis includes detecting a selected wavelength in the emissions indicative of the presence of the selected chemical species. A plurality of probes can be suspended at an end of a respective cable, with the transmitting and analyzing steps for each probe being synchronized sequentially for one set of support equipment and instrumentation to monitor at multiple test points. The optical apparatus is arranged about the light guide axis so that the selected chemical species are excited in the fluid in alignment with the light guide axis. Optical emissions are received from the excited chemical species along such axis. 18 figs.

Apparatus for detecting alpha radiation in difficult access areas

DOEpatents

Steadman, Peter; MacArthur, Duncan W.

1997-09-02

An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure. A voltage source is connected between the indicator means and the electrically conductive enclosure for creating an electric field between the electrically conductive expandable electrode and the enclosure.

Measuring Fluxes Of Heat To A Plasma-Arc Anode

NASA Technical Reports Server (NTRS)

Sankovic, John M.; Menart, James A.; Pfender, Emil; Heberlein, Joachim

1995-01-01

Three probes constructed to provide measurements indicative of conductive, convective, and radiative transfer of heat from free-burning plasma arc to water-cooled copper anode used in generating arc. Each probe consists mainly of copper body with two thermocouples embedded at locations 4 mm apart along length. Thermocouples provide measure of rate of conduction of heat along probe and transfers of heat from plasma to sensing surface at tip of probe. Probes identical except sensing surface of one uncoated and other two coated with different materials to make them sensitive to different components of overall flux of heat.

An intervention to improve the catheter associated urinary tract infection rate in a medical intensive care unit: Direct observation of catheter insertion procedure.

PubMed

Galiczewski, Janet M; Shurpin, Kathleen M

2017-06-01

Healthcare associated infections from indwelling urinary catheters lead to increased patient morbidity and mortality. The purpose of this study was to determine if direct observation of the urinary catheter insertion procedure, as compared to the standard process, decreased catheter utilization and urinary tract infection rates. This case control study was conducted in a medical intensive care unit. During phase I, a retrospective data review was conducted on utilsiation and urinary catheter infection rates when practitioners followed the institution's standard insertion algorithm. During phase II, an intervention of direct observation was added to the standard insertion procedure. The results demonstrated no change in utilization rates, however, CAUTI rates decreased from 2.24 to 0 per 1000 catheter days. The findings from this study may promote changes in clinical practice guidelines leading to a reduction in urinary catheter utilization and infection rates and improved patient outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rotating concave eddy current probe

DOEpatents

Roach, Dennis P [Albuquerque, NM; Walkington, Phil [Albuquerque, NM; Rackow, Kirk A [Albuquerque, NM; Hohman, Ed [Albuquerque, NM

2008-04-01

A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

Strand Invasion Based Amplification (SIBA®): a novel isothermal DNA amplification technology demonstrating high specificity and sensitivity for a single molecule of target analyte.

PubMed

Hoser, Mark J; Mansukoski, Hannu K; Morrical, Scott W; Eboigbodin, Kevin E

2014-01-01

Isothermal nucleic acid amplification technologies offer significant advantages over polymerase chain reaction (PCR) in that they do not require thermal cycling or sophisticated laboratory equipment. However, non-target-dependent amplification has limited the sensitivity of isothermal technologies and complex probes are usually required to distinguish between non-specific and target-dependent amplification. Here, we report a novel isothermal nucleic acid amplification technology, Strand Invasion Based Amplification (SIBA). SIBA technology is resistant to non-specific amplification, is able to detect a single molecule of target analyte, and does not require target-specific probes. The technology relies on the recombinase-dependent insertion of an invasion oligonucleotide (IO) into the double-stranded target nucleic acid. The duplex regions peripheral to the IO insertion site dissociate, thereby enabling target-specific primers to bind. A polymerase then extends the primers onto the target nucleic acid leading to exponential amplification of the target. The primers are not substrates for the recombinase and are, therefore unable to extend the target template in the absence of the IO. The inclusion of 2'-O-methyl RNA to the IO ensures that it is not extendible and that it does not take part in the extension of the target template. These characteristics ensure that the technology is resistant to non-specific amplification since primer dimers or mis-priming are unable to exponentially amplify. Consequently, SIBA is highly specific and able to distinguish closely-related species with single molecule sensitivity in the absence of complex probes or sophisticated laboratory equipment. Here, we describe this technology in detail and demonstrate its use for the detection of Salmonella.

Direct measurement of time-dependent anesthetized in vivo human pulp temperature.

PubMed

Runnacles, Patrício; Arrais, Cesar Augusto Galvão; Pochapski, Marcia Thais; dos Santos, Fábio André; Coelho, Ulisses; Gomes, João Carlos; De Goes, Mário Fernando; Gomes, Osnara Maria Mongruel; Rueggeberg, Frederick Allen

2015-01-01

Human intrapupal tooth temperature is considered to be similar to that of the body (≈37 °C), although the actual temperature has never been measured. This study evaluated the in vivo, human, basal, coronal intrapulpal temperature of anesthetized upper first premolars. After approval of the local Ethics Committee was obtained (protocol no. 255,945), upper right and left first premolars requiring extraction for orthodontic reasons from 8 volunteers, ranging from 12 to 30 years old, received infiltrative and intraligamental anesthesia. The teeth (n=15) were isolated using rubber dam and a small, occlusal preparation was made using high-speed handpiece, under constant air-water spray, until a minute pulp exposure was attained. The sterile probe from a wireless, NIST-traceable, temperature acquisition system (Thermes WFI) was inserted directly into the coronal pulp. Once the probe was properly positioned and stable, real-time temperature data were continuously acquired for approximately 25 min. Data (°C) were subjected to 2-tailed, paired t-test (α=0.05), and the 95% confidence intervals for the initial and 25-min mean temperatures were also determined. The initial pulp temperature value (31.8±1.5 °C) was significantly lower than after 25-min (35.3±0.7 °C) (p<0.05). The 95% confidence interval for the initial temperature ranged from 31.0 to 32.6 °C and from 35.0 to 35.7 °C after 25 min. A slow, gradual temperature increase was observed after probe insertion until the pulp temperature reached a plateau, usually after 15 min. Consistent coronal, human, in vivo temperature values were observed and were slightly, but significantly below that of body core temperature. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Coupling neutron reflectivity with cell-free protein synthesis to probe membrane protein structure in supported bilayers

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

Soranzo, Thomas; Martin, Donald K.; Lenormand, Jean -Luc

Here, the structure of the p7 viroporin, an oligomeric membrane protein ion channel involved in the assembly and release of the hepatitis C virus, was determined from proteins expressed and inserted directly into supported model lipid membranes using cell-free protein expression. Cell-free protein expression allowed (i) high protein concentration in the membrane, (ii) control of the protein’s isotopic constitution, and (iii) control over the lipid environment available to the protein. Here, we used cell-free protein synthesis to directly incorporate the hepatitis C virus (HCV) p7 protein into supported lipid bilayers formed from physiologically relevant lipids (POPC or asolectin) for bothmore » direct structural measurements using neutron reflectivity (NR) and conductance measurements using electrical impedance spectroscopy (EIS). We report that HCV p7 from genotype 1a strain H77 adopts a conical shape within lipid bilayers and forms a viroporin upon oligomerization, confirmed by EIS conductance measurements. This combination of techniques represents a novel approach to the study of membrane proteins and, through the use of selective deuteration of particular amino acids to enhance neutron scattering contrast, has the promise to become a powerful tool for characterizing the protein conformation in physiologically relevant environments and for the development of biosensor applications.« less

Coupling neutron reflectivity with cell-free protein synthesis to probe membrane protein structure in supported bilayers

DOE PAGES

Soranzo, Thomas; Martin, Donald K.; Lenormand, Jean -Luc; ...

2017-06-13

Here, the structure of the p7 viroporin, an oligomeric membrane protein ion channel involved in the assembly and release of the hepatitis C virus, was determined from proteins expressed and inserted directly into supported model lipid membranes using cell-free protein expression. Cell-free protein expression allowed (i) high protein concentration in the membrane, (ii) control of the protein’s isotopic constitution, and (iii) control over the lipid environment available to the protein. Here, we used cell-free protein synthesis to directly incorporate the hepatitis C virus (HCV) p7 protein into supported lipid bilayers formed from physiologically relevant lipids (POPC or asolectin) for bothmore » direct structural measurements using neutron reflectivity (NR) and conductance measurements using electrical impedance spectroscopy (EIS). We report that HCV p7 from genotype 1a strain H77 adopts a conical shape within lipid bilayers and forms a viroporin upon oligomerization, confirmed by EIS conductance measurements. This combination of techniques represents a novel approach to the study of membrane proteins and, through the use of selective deuteration of particular amino acids to enhance neutron scattering contrast, has the promise to become a powerful tool for characterizing the protein conformation in physiologically relevant environments and for the development of biosensor applications.« less

Cell response to long term mechanical interaction with nanopipettes

NASA Astrophysics Data System (ADS)

Orynbayeva, Zulfiya; Singhal, Riju; Vitol, Elina; Bouchard, Michael; Azizkhan-Clifford, Jane; Layton, Bradley; Friedman, Gary; Gogotsi, Yury

2009-03-01

Traditional microinjection into cells is performed over a relatively short term. Pipettes are typically withdrawn following any kind of injection. On the other hand, there is growing interest in using nanopipettes for cellular and subcellular probing. This interest is partly due to new developments in nanopipette technology which employ carbon nanotubes and provide robustness, flexibility, and biocompatibility. However, as far as we know, no systematic study of physiological, biochemical, and biophysical processes associated with cell response to lengthy mechanical stimulations by nanopipette probing have been performed so far. We present a detailed investigation of a wide range of effects of long term pipette insertion into a cell. Both traditional glass micropipettes and the novel carbon nanotube-tipped probes were involved in this study. The mechanism of Ca2+ response to the mechanical stimuli introduced by the nanopipette, and the role of different organelles in this mechanism were studied. We hypothesize that the calcium response is a function of cytoskeleton integrity and the mode of coupling between the cytoskeleton and the plasma membrane domains.

Dependence of fluorescent protein brightness on protein concentration in solution and enhancement of it

PubMed Central

Morikawa, Takamitsu J.; Fujita, Hideaki; Kitamura, Akira; Horio, Takashi; Yamamoto, Johtaro; Kinjo, Masataka; Sasaki, Akira; Machiyama, Hiroaki; Yoshizawa, Keiko; Ichimura, Taro; Imada, Katsumi; Nagai, Takeharu; Watanabe, Tomonobu M.

2016-01-01

Fluorescent proteins have been widely used in biology because of their compatibility and varied applications in living specimens. Fluorescent proteins are often undesirably sensitive to intracellular conditions such as pH and ion concentration, generating considerable issues at times. However, harnessing these intrinsic sensitivities can help develop functional probes. In this study, we found that the fluorescence of yellow fluorescent protein (YFP) depends on the protein concentration in the solution and that this dependence can be enhanced by adding a glycine residue in to the YFP; we applied this finding to construct an intracellular protein-crowding sensor. A Förster resonance energy transfer (FRET) pair, involving a cyan fluorescent protein (CFP) insensitive to protein concentration and a glycine-inserted YFP, works as a genetically encoded probe to evaluate intracellular crowding. By measuring the fluorescence of the present FRET probe, we were able to detect dynamic changes in protein crowding in living cells. PMID:26956628

Measurement of low temperature plasma properties using non-invasive impedance measurements

NASA Astrophysics Data System (ADS)

Gillman, Eric; Amatucci, Bill; Tejero, Erik; Blackwell, David

2017-10-01

A plasma discharge can be modeled electrically as a combination of capacitors, resistors, and inductors. The plasma, much like an RLC circuit, will have resonances at particular frequencies. The location in frequency space of these resonances provides information about the plasma parameters. These resonances can be detected using impedance measurements, where the AC impedance of the plasma is measured by sweeping the frequency of an AC voltage applied to a sensor and determining the magnitude and phase of the measured current. In this work, an electrode used to sustain a glow discharge is also used as an impedance probe. The novelty of this method is that insertion of a physical probe, which can introduce perturbation and/or contamination, is not necessary. This non-invasive impedance probe method is used to measure the plasma discharge density in various regimes of plasma operation. Experimental results are compared to the basic circuit model results. The potential applications of this diagnostic method and regimes over which this measurement method is valid will be discussed.

Real-time PCR Detection of Brucella Abortus: A Comparative Study of SYBR Green I, 5'-exonuclease, and Hybridization Probe Assays

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

Newby, Deborah Trishelle; Hadfield, Ted; Roberto, Francisco Figueroa

Real-time PCR provides a means of detecting and quantifying DNA targets by monitoring PCR product accumulation during cycling as indicated by increased fluorescence. A number of different approaches can be used to generate the fluorescence signal. Three approaches—SYBR Green I (a double-stranded DNA intercalating dye), 5'-exonuclease (enzymatically released fluors), and hybridization probes (fluorescence resonance energy transfer)—were evaluated for use in a real-time PCR assay to detect Brucella abortus. The three assays utilized the same amplification primers to produce an identical amplicon. This amplicon spans a region of the B. abortus genome that includes portions of the alkB gene and themore » IS711 insertion element. All three assays were of comparable sensitivity, providing a linear assay over 7 orders of magnitude (from 7.5 ng down to 7.5 fg). However, the greatest specificity was achieved with the hybridization probe assay.« less

Performance of a combined three-hole conductivity probe for void fraction and velocity measurement in air-water flows

NASA Astrophysics Data System (ADS)

Borges, João Eduardo; Pereira, Nuno H. C.; Matos, Jorge; Frizell, Kathleen H.

2010-01-01

The development of a three-hole pressure probe with back-flushing combined with a conductivity probe, used for measuring simultaneously the magnitude and direction of the velocity vector in complex air-water flows, is described in this paper. The air-water flows envisaged in the current work are typically those occurring around the rotors of impulse hydraulic turbines (like the Pelton and Cross-Flow turbines), where the flow direction is not known prior to the data acquisition. The calibration of both the conductivity and three-hole pressure components of the combined probe in a rig built for the purpose, where the probe was placed in a position similar to that adopted for the flow measurements, will be reported. After concluding the calibration procedure, the probe was utilized in the outside region of a Cross-Flow turbine rotor. The experimental results obtained in the present study illustrate the satisfactory performance of the combined probe, and are encouraging toward its use for characterizing the velocity field of other complex air-water flows.

Virtual impactor

DOEpatents

Yeh, Hsu-Chi; Chen, Bean T.; Cheng, Yung-Sung; Newton, George J.

1988-08-30

A virtual impactor having improved efficiency and low wall losses in which a core of clean air is inserted into the aerosol flow while aerosol flow is maintained adjacent inner wall surfaces of the focusing portion of the impactor. The flow rate of the core and the length of the throat of the impactor's collection probe, as well as the dimensional relationships of other components of the impactor adjacent the separation region of the impactor, are selected to optimize separation efficiency.

Use of fathometers and electrical-conductivity probes to monitor riverbed scour at bridge piers

USGS Publications Warehouse

Hayes, Donald C.; Drummond, F.E.

1995-01-01

Two methods, a fathometer system and an electrical- conductivity probe system, were developed to monitor scour at bridge piers. The scour-monitoring systems consisted of a sensor (fathometer or electrical- conductivity probe), power supply, data logger, relay, and system program. The fathometer system was installed and tested at a bridge over the Leipsic River at Leipsic, Delaware, and at a bridge over Sinepuxent Bay near Ocean City. Maryland. Field data collected indicate that fathometers can be used to identify and monitor the riverbed elevation if post processing of the data and trends in the data are used to determine the riverbed location in relation to the transducer. The accuracy of the system is approximately the same as the resolution of the fathometer. Signal scatter can be a major source of error in the data. The electrical- conductivity probe system was installed and tested at a bridge over the Pamunkey River near Hanover, Virginia. The approximate elevation of the riverbed is determined by comparing conductivities of the surface-water flow with conductivities of submerged bed material from sensors located in each. Field data collected indicate that an electrical- conductivity probe, as tested, has limited usefulness in identifying and monitoring the riverbed elevation during high flows. As the discharge increases, the concentration of sediment in the surface-water flow increases, especially near the riverbed. Conductivities, measured at the sensors in the surface-water flow could not be distinguished from conductivities measured at the shallowest sensor in the submerged bed material.

P-Element Insertion Alleles of Essential Genes on the Third Chromosome of Drosophila Melanogaster: Correlation of Physical and Cytogenetic Maps in Chromosomal Region 86e-87f

PubMed Central

Deak, P.; Omar, M. M.; Saunders, RDC.; Pal, M.; Komonyi, O.; Szidonya, J.; Maroy, P.; Zhang, Y.; Ashburner, M.; Benos, P.; Savakis, C.; Siden-Kiamos, I.; Louis, C.; Bolshakov, V. N.; Kafatos, F. C.; Madueno, E.; Modolell, J.; Glover, D. M.

1997-01-01

We have established a collection of 2460 lethal or semi-lethal mutant lines using a procedure thought to insert single P elements into vital genes on the third chromosome of Drosophila melanogaster. More than 1200 randomly selected lines were examined by in situ hybridization and 90% found to contain single insertions at sites that mark 89% of all lettered subdivisions of the Bridges' map. A set of chromosomal deficiencies that collectively uncover ~25% of the euchromatin of chromosome 3 reveal lethal mutations in 468 lines corresponding to 145 complementation groups. We undertook a detailed analysis of the cytogenetic interval 86E-87F and identified 87 P-element-induced mutations falling into 38 complementation groups, 16 of which correspond to previously known genes. Twenty-one of these 38 complementation groups have at least one allele that has a P-element insertion at a position consistent with the cytogenetics of the locus. We have rescued P elements and flanking chromosomal sequences from the 86E-87F region in 35 lines with either lethal or genetically silent P insertions, and used these as probes to identify cosmids and P1 clones from the Drosophila genome projects. This has tied together the physical and genetic maps and has linked 44 previously identified cosmid contigs into seven ``supercontigs'' that span the interval. STS data for sequences flanking one side of the P-element insertions in 49 lines has identified insertions in the αγ element at 87C, two known transposable elements, and the open reading frames of seven putative single copy genes. These correspond to five known genes in this interval, and two genes identified by the homology of their predicted products to known proteins from other organisms. PMID:9409831

Instability of the insertional mutation in CftrTgH(neoim)Hgu cystic fibrosis mouse model

PubMed Central

Charizopoulou, Nikoletta; Jansen, Silke; Dorsch, Martina; Stanke, Frauke; Dorin, Julia R; Hedrich, Hans-Jürgen; Tümmler, Burkhard

2004-01-01

Background A major boost to the cystic fibrosis disease research was given by the generation of various mouse models using gene targeting in embryonal stem cells. Moreover, the introduction of the same mutation on different inbred strains generating congenic strains facilitated the search for modifier genes. From the original CftrTgH(neoim)Hgu CF mouse model we have generated using strict brother × sister mating two inbred CftrTgH(neoim)Hgu mouse lines (CF/1 and CF/3). Thereafter, the insertional mutation was introgressed from CF/3 into three inbred backgrounds (C57BL/6, BALB/c, DBA/2J) generating congenic animals. In every backcross cycle germline transmission of the insertional mutation was monitored by direct probing the insertion via Southern RFLP. In order to bypass this time consuming procedure we devised an alternative PCR based protocol whereby mouse strains are differentiated at the Cftr locus by Cftr intragenic microsatellite genotypes that are tightly linked to the disrupted locus. Results Using this method we were able to identify animals carrying the insertional mutation based upon the differential haplotypic backgrounds of the three inbred strains and the mutant CftrTgH(neoim)Hgu at the Cftr locus. Moreover, this method facilitated the identification of the precise vector excision from the disrupted Cftr locus in two out of 57 typed animals. This reversion to wild type status took place without any loss of sequence revealing the instability of insertional mutations during the production of congenic animals. Conclusions We present intragenic microsatellite markers as a tool for fast and efficient identification of the introgressed locus of interest in the recipient strain during congenic animal breeding. Moreover, the same genotyping method allowed the identification of a vector excision event, posing questions on the stability of insertional mutations in mice. PMID:15102331

Mission Advantages of Constant Power, Variable Isp Electrostatic Thrusters

NASA Technical Reports Server (NTRS)

Oleson, Steven R.

2000-01-01

Electric propulsion has moved from station-keeping capability for spacecraft to primary propulsion with the advent of both the Deep Space One asteroid flyby and geosynchronous spacecraft orbit insertion. In both cases notably more payload was delivered than would have been possible with chemical propulsion. To provide even greater improvements electrostatic thruster performance could be varied in specific impulse, but kept at constant power to provide better payload or trip time performance for different mission phases. Such variable specific impulse mission applications include geosynchronous and low earth orbit spacecraft stationkeeping and orbit insertion, geosynchronous reusable tug missions, and interplanetary probes. The application of variable specific impulse devices is shown to add from 5 to 15% payload for these missions. The challenges to building such devices include variable voltage power supplies and extending fuel throughput capabilities across the specific impulse range.

Detection of explosives in soils

DOEpatents

Chambers, William B.; Rodacy, Philip J.; Phelan, James M.; Woodfin, Ronald L.

2002-01-01

An apparatus and method for detecting explosive-indicating compounds in subsurface soil. The apparatus has a probe with an adsorbent material on some portion of its surface that can be placed into soil beneath the ground surface, where the adsorbent material can adsorb at least one explosive-indicating compound. The apparatus additional has the capability to desorb the explosive-indicating compound through heating or solvent extraction. A diagnostic instrument attached to the probe detects the desorbed explosive-indicating compound. In the method for detecting explosive-indicating compounds in soil, the sampling probe with an adsorbent material on at least some portion of a surface of the sampling probe is inserted into the soil to contact the adsorbent material with the soil. The explosive-indicating compounds are then desorbed and transferred as either a liquid or gas sample to a diagnostic tool for analysis. The resulting gas or liquid sample is analyzed using at least one diagnostic tool selected from the group consisting of an ion-mobility spectrometer, a gas chromatograph, a high performance liquid chromatograph, a capillary electrophoresis chromatograph, a mass spectrometer, a Fourier-transform infrared spectrometer and a Raman spectrometer to detect the presence of explosive-indicating compounds.

CFD evaluation of an advanced thrust vector control concept

NASA Technical Reports Server (NTRS)

Tiarn, Weihnurng; Cavalleri, Robert

1990-01-01

A potential concept that can offer an alternate method for thrust vector control of the Space Shuttle Solid Rocket Booster is the use of a cylindrical probe that is inserted (on demand) through the wall of the rocket nozzle. This Probe Thrust Vector Control (PTVC) concept is an alternate to that of a gimbaled nozzle or a Liquid Injection Thrust Vector (LITVC) system. The viability of the PTVC concept can be assessed either experimentally and/or with the use of CFD. A purely experimental assessment can be time consuming and expensive, whereas a CFD assessment can be very time- and cost-effective. Two key requirements of the proposed concept are PTVC vectoring performance and the active cooling requirements for the probe to maintain its thermal and structural integrity. An active thermal cooling method is the injection of coolant around the pheriphery of the probe. How much coolant is required and how this coolant distributes itself in the flow field is of major concern. The objective of the work reported here is the use of CFD to answer these question and in the design of test hardware to substantiate the results of the CFD predictions.

Lung vasculature imaging using speckle variance optical coherence tomography

NASA Astrophysics Data System (ADS)

Cua, Michelle; Lee, Anthony M. D.; Lane, Pierre M.; McWilliams, Annette; Shaipanich, Tawimas; MacAulay, Calum E.; Yang, Victor X. D.; Lam, Stephen

2012-02-01

Architectural changes in and remodeling of the bronchial and pulmonary vasculature are important pathways in diseases such as asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. However, there is a lack of methods that can find and examine small bronchial vasculature in vivo. Structural lung airway imaging using optical coherence tomography (OCT) has previously been shown to be of great utility in examining bronchial lesions during lung cancer screening under the guidance of autofluorescence bronchoscopy. Using a fiber optic endoscopic OCT probe, we acquire OCT images from in vivo human subjects. The side-looking, circumferentially-scanning probe is inserted down the instrument channel of a standard bronchoscope and manually guided to the imaging location. Multiple images are collected with the probe spinning proximally at 100Hz. Due to friction, the distal end of the probe does not spin perfectly synchronous with the proximal end, resulting in non-uniform rotational distortion (NURD) of the images. First, we apply a correction algorithm to remove NURD. We then use a speckle variance algorithm to identify vasculature. The initial data show a vascaulture density in small human airways similar to what would be expected.

Expansion of genetic testing in the division of functional genomics, research center for bioscience and technology, tottori university from 2000 to 2013.

PubMed

Adachi, Kaori

2014-03-01

At the Division of Functional Genomics, Research Center for Bioscience and Technology, Tottori University, we have been making an effort to establish a genetic testing facility that can provide the same screening procedures conducted worldwide. Direct Sequencing of PCR products is the main method to detect point mutations, small deletions and insertions. Multiplex Ligation-dependent Probe Amplification (MLPA) was used to detect large deletions or insertions. Expansion of the repeat was analyzed for triplet repeat diseases. Original primers were constructed for 41 diseases when the reported primers failed to amplify the gene. Prediction of functional effects of human nsSNPs (PolyPhen) was used for evaluation of novel mutations. From January 2000 to September 2013, a total of 1,006 DNA samples were subjected to genetic testing in the Division of Functional Genomics, Research Center for Bioscience and Technology, Tottori University. The hospitals that requested genetic testing were located in 43 prefectures in Japan and in 11 foreign countries. The genetic testing covered 62 diseases, and mutations were detected in 287 out of 1,006 with an average mutation detection rate of 24.7%. There were 77 samples for prenatal diagnosis. The number of samples has rapidly increased since 2010. In 2013, the next-generation sequencers were introduced in our facility and are expected to provide more comprehensive genetic testing in the near future. Nowadays, genetic testing is a popular and powerful tool for diagnosis of many genetic diseases. Our genetic testing should be further expanded in the future.

Casting copper to tungsten for high-power arc lamp cathodes

NASA Technical Reports Server (NTRS)

Will, H. A.

1974-01-01

Voids forming at interface when copper is cast onto tungsten can be eliminated by adding wetting agent during casting process. Small amount of copper and nickel are cast onto thoriated tungsten insert, insert is recast with more copper to form electrode. Good thermal conductance results in long-lived cathode.

NASA DART

NASA Technical Reports Server (NTRS)

Hale, L. C.

1977-01-01

A low cost conductivity probe system for use with the Super Loki Dart meteorological sounding rocket is described. Miniaturization of the Super Arcas blunt probe, operation of the blunt probe experiment, flight tests, and development of a Lyman-alpha probe are among the topics discussed.

Differentiation of surface and bulk conductivities in topological insulator via four-probe spectroscopy

DOE PAGES

Zhang, Xiaoguang; McGuire, Michael A.; Chen, Yong P.; ...

2016-03-08

Topological insulators, with characteristic topological surface states, have emerged as a new state of matter with rich potentials for both fundamental physics and device applications. However, the experimental detection of the surface transport has been hampered by the unavoidable extrinsic conductivity associated with the bulk crystals. Here we show that a four-probe transport spectroscopy in a multi-probe scanning tunneling microscopy system can be used to differentiate conductivities from the surface states and the coexisting bulk states in topological insulators. We derive a scaling relation of measured resistance with respect to varying inter-probe spacing for two interconnected conduction channels, which allowsmore » quantitative determination of conductivities from both channels. Using this method, we demonstrate the separation of 2D and 3D conduction in topological insulators by comparing the conductance scaling of Bi 2Se 3, Bi 2Te 2Se, and Sb-doped Bi 2Se 3 with that of a pure 2D conductance of graphene on SiC substrate. We also report the 2D conductance enhancement due to the surface doping effect in topological insulators. This technique can be applied to reveal 2D to 3D crossover of conductance in other complex systems.« less

Isentropic compression of argon

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

Veeser, L.R.; Ekdahl, C.A.; Oona, H.

1997-06-01

The compression was done in an MC-1 flux compression (explosive) generator, in order to study the transition from an insulator to a conductor. Since conductivity signals were observed in all the experiments (except when the probe is removed), both the Teflon and the argon are becoming conductive. The conductivity could not be determined (Teflon insulation properties unknown), but it could be bounded as being {sigma}=1/{rho}{le}8({Omega}cm){sub -1}, because when the Teflon breaks down, the dielectric constant is reduced. The Teflon insulator problem remains, and other ways to better insulate the probe or to measure the conductivity without a probe is beingmore » sought.« less

Large-scale synthesis of arrays of high-aspect-ratio rigid vertically aligned carbon nanofibres

NASA Astrophysics Data System (ADS)

Melechko, A. V.; McKnight, T. E.; Hensley, D. K.; Guillorn, M. A.; Borisevich, A. Y.; Merkulov, V. I.; Lowndes, D. H.; Simpson, M. L.

2003-09-01

We report on techniques for catalytic synthesis of rigid, high-aspect-ratio, vertically aligned carbon nanofibres by dc plasma enhanced chemical vapour deposition that are tailored for applications that require arrays of individual fibres that feature long fibre lengths (up to 20 µm) such as scanning probe microscopy, penetrant cell and tissue probing arrays and mechanical insertion approaches for gene delivery to cell cultures. We demonstrate that the definition of catalyst nanoparticles is the critical step that enables growth of individual, long-length fibres and discuss methods for catalyst particle preparation that allow the growth of individual isolated nanofibres from catalyst dots with diameters as large as 500 nm. This development enables photolithographic definition of catalyst and therefore the inexpensive, large-scale production of such arrays.

Nanowire-based single-cell endoscopy

NASA Astrophysics Data System (ADS)

Yan, Ruoxue; Park, Ji-Ho; Choi, Yeonho; Heo, Chul-Joon; Yang, Seung-Man; Lee, Luke P.; Yang, Peidong

2012-03-01

One-dimensional smart probes based on nanowires and nanotubes that can safely penetrate the plasma membrane and enter biological cells are potentially useful in high-resolution and high-throughput gene and drug delivery, biosensing and single-cell electrophysiology. However, using such probes for optical communication across the cellular membrane at the subwavelength level remains limited. Here, we show that a nanowire waveguide attached to the tapered tip of an optical fibre can guide visible light into intracellular compartments of a living mammalian cell, and can also detect optical signals from subcellular regions with high spatial resolution. Furthermore, we show that through light-activated mechanisms the endoscope can deliver payloads into cells with spatial and temporal specificity. Moreover, insertion of the endoscope into cells and illumination of the guided laser did not induce any significant toxicity in the cells.

Heat Deposition and Heat Removal in the UCLA Continuous Current Tokamak

NASA Astrophysics Data System (ADS)

Brown, Michael Lee

1990-01-01

Energy transfer processes in a steady-state tokamak are examined both theoretically and experimentally in order to determine the patterns of plasma heat deposition to material surfaces and the methods of heat removal. Heat transfer experiments involving actively cooled limiters and heat flux probes were performed in the UCLA Continuous Current Tokamak (CCT). The simple exponential model of plasma power deposition was extended to describe the global heat deposition to the first wall of a steady-state tokamak. The heat flux distribution in CCT was determined from measurements of heat flow to 32 large-area water-cooled Faraday shield panels. Significant toroidal and poloidal asymmetries were observed, with the maximum heat fluxes tending to fall on the lower outside panels. Heat deposition to the water-cooled guard limiters of an ion Bernstein wave antenna in CCT was measured during steady-state operation. Very strong asymmetries were observed. The heat distribution varied greatly with magnetic field. Copper heat flux sensors incorporating internal thermocouples were developed to measure plasma power deposition to exterior probe surfaces and heat removal from water -cooled interior surfaces. The resulting inverse heat conduction problem was solved using the function specification method. Cooling by an impinging liquid jet was investigated. One end of a cylindrical copper heat flux sensor was heated by a DC electrical arc and the other end was cooled by a low velocity water jet at 1 atm. Critical heat flux (CHF) values for the 55-80 ^circC sub-cooled free jets were typically 2.5 times published values for saturated free jets. For constrained jets, CHF values were about 20% lower. Heat deposition and heat removal in thick (3/4 inch diameter) cylindrical metal probes (SS304 or copper) inserted into a steady-state tokamak plasma were measured for a broad range of heat loads. The probes were cooled internally by a constrained jet of either air or water. Steady -state heat removal rates of up to 400 W/cm^2 were attained at the water cooled surface, and conditions of CHF were experimentally identified. Heat transfer in a hemispherical limiter is discussed.

Effect of photoelectric emission on blunt probe conductivity measurements in the stratosphere

NASA Astrophysics Data System (ADS)

John, Thomas; Chopra, P.; Garg, S. C.

2009-06-01

Two identical planar blunt probes of stainless steel material, biased with a bipolar ramp voltage, are used to measure the stratospheric polar conductivities to altitudes of 34 km. One probe (DP) is mounted closer to the gondola, looking downwards and shielded from sunlight, while the other (SP) is mounted looking sideways, away from the gondola. The daytime observations of positive ions in the 29-34 km altitude range with SP, and of negative ions at 34 km with DP, show photoelectric contaminations induced by solar UV radiations in the 190-230 nm band. These contaminations are found to be due to photoemissions from the SP probe steel surface and from the carbon paint that coats the surface of the gondola, respectively. It is found that, a segment of the photocurrent contaminated I-V curve, recorded with SP at higher negative probe potentials, is linear, and it can give the ambient positive polar conductivity.

General expressions for the coupling coefficient, quality and filling factors for a cavity with an insert using energy coupled mode theory

NASA Astrophysics Data System (ADS)

Elnaggar, Sameh Y.; Tervo, Richard; Mattar, Saba M.

2014-05-01

A cavity (CV) with a dielectric resonator (DR) insert forms an excellent probe for the use in electron paramagnetic resonance (EPR) spectrometers. The probe’s coupling coefficient, κ, the quality factor, Q, and the filling factor, η are vital in assessing the EPR spectrometer’s performance. Coupled mode theory (CMT) is used to derive general expressions for these parameters. For large permittivity the dominating factor in κ is the ratio of the DR and CV cross sectional areas rather than the dielectric constant. Thus in some cases, resonators with low dielectric constant can couple much stronger with the cavity than do resonators with a high dielectric constant. When the DR and CV frequencies are degenerate, the coupled η is the average of the two uncoupled ones. In practical EPR probes the coupled η is approximately half of that of the DR. The Q of the coupled system generally depends on the eigenvectors, uncoupled frequencies (ω1, ω2) and the individual quality factors (Q1, Q2). It is calculated for different probe configurations and found to agree with the corresponding HFSS® simulations. Provided there is a large difference between the Q1, Q2 pair and the frequencies of DR and CV are degenerate, Q is approximately equal to double the minimum of Q1 and Q2. In general, the signal enhancement ratio, I/Iempty, is obtained from Q and η. For low loss DRs it only depends on η1/η2. However, when the DR has a low Q, the uncoupled Qs are also needed. In EPR spectroscopy it is desirable to excite only a single mode. The separation between the modes, Φ, is calculated as a function of κ and Q. It is found to be significantly greater than five times the average bandwidth. Thus for practical probes, it is possible to excite one of the coupled modes without exciting the other. The CMT expressions derived in this article are quite general and are in excellent agreement with the lumped circuit approach and finite numerical simulations. Hence they can also be applied to a loop-gap resonator in a cavity. For the design effective EPR probes, one needs to consider the κ, Q and η parameters.

Bacterio-opsin mutants of Halobacterium halobium

PubMed Central

Betlach, Mary; Pfeifer, Felicitas; Friedman, James; Boyer, Herbert W.

1983-01-01

The bacterio-opsin (bop) gene of Halobacterium halobium R1 has been cloned with about 40 kilobases of flanking genomic sequence. The 40-kilobase segment is derived from the (G+C)-rich fraction of the chromosome and is not homologous to the major (pHH1) or minor endogenous covalently closed circular DNA species of H. halobium. A 5.1-kilobase Pst I fragment containing the bop gene was subcloned in pBR322 and a partial restriction map was determined. Defined restriction fragments of this clone were used as probes to analyze the defects associated with the bop gene in 12 bacterio-opsin mutants. Eleven out of 12 of the mutants examined had inserts ranging from 350 to 3,000 base pairs either in the bop gene or up to 1,400 base pairs upstream. The positions of the inserts were localized to four regions in the 5.1-kilobase genomic fragment: within the gene (one mutant), in a region that overlaps the 5′ end of the gene (seven mutants), and in two different upstream regions (three mutants). Two revertants of the mutant with the most distal insert had an additional insert in the same region. The polar effects of these inserts are discussed in terms of inactivation of a regulatory gene or disruption of part of a coordinately expressed operon. Given the defined nature of the bop mRNA—i.e., it has a 5′ leader sequence of three ribonucleotides—these observations indicate that the bop mRNA might be processed from a large mRNA transcript. Images PMID:16593291

Determining Confounding Sensitivities In Eddy Current Thin Film Measurements

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

Gros, Ethan; Udpa, Lalita; Smith, James A.

Determining Confounding Sensitivities In Eddy Current Thin Film Measurements Ethan Gros, Lalita Udpa, Electrical Engineering, Michigan State University, East Lansing MI 48824 James A. Smith, Experiment Analysis, Idaho National Laboratory, Idaho Falls ID 83415 Eddy current (EC) techniques are widely used in industry to measure the thickness of non-conductive films on a metal substrate. This is done using a system whereby a coil carrying a high-frequency alternating current is used to create an alternating magnetic field at the surface of the instrument's probe. When the probe is brought near a conductive surface, the alternating magnetic field will induce ECs inmore » the conductor. The substrate characteristics and the distance of the probe from the substrate (the coating thickness) affect the magnitude of the ECs. The induced currents load the probe coil affecting the terminal impedance of the coil. The measured probe impedance is related to the lift off between coil and conductor as well as conductivity of the test sample. For a known conductivity sample, the probe impedance can be converted into an equivalent film thickness value. The EC measurement can be confounded by a number of measurement parameters. It is the goal of this research to determine which physical properties of the measurement set-up and sample can adversely affect the thickness measurement. The eddy current testing is performed using a commercially available, hand held eddy current probe (ETA3.3H spring loaded eddy probe running at 8 MHz) that comes with a stand to hold the probe. The stand holds the probe and adjusts the probe on the z-axis to help position the probe in the correct area as well as make precise measurements. The signal from the probe is sent to a hand held readout, where the results are recorded directly in terms of liftoff or film thickness. Understanding the effect of certain factors on the measurements of film thickness, will help to evaluate how accurate the ETA3.3H spring loaded eddy probe is at measuring film thickness under varying experimental conditions. This research will study the effects of a number of factors such as i) calibration, ii) conductivity, iii) edge effect, iv) surface finish of base material and v) cable condition and compare with the long term reproducibility of a standard measurement. This work was performed with support from the Department of Energy under the United States National Nuclear Security Administration (NNSA) at the Idaho National Laboratory.« less

Timing performance of the silicon PET insert probe

PubMed Central

Studen, A.; Burdette, D.; Chesi, E.; Cindro, V.; Clinthorne, N. H.; Cochran, E.; Grošičar, B.; Kagan, H.; Lacasta, C.; Linhart, V.; Mikuž, M.; Stankova, V.; Weilhammer, P.; Žontar, D.

2010-01-01

Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 × 1 mm2 pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an 22Na source, and a scintillator (LYSO)–PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron–hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns. PMID:20215445

Timing performance of the silicon PET insert probe.

PubMed

Studen, A; Burdette, D; Chesi, E; Cindro, V; Clinthorne, N H; Cochran, E; Grosicar, B; Kagan, H; Lacasta, C; Linhart, V; Mikuz, M; Stankova, V; Weilhammer, P; Zontar, D

2010-01-01

Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an (22)Na source, and a scintillator (LYSO)-PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron-hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns.

The Sheath-less Planar Langmuir Probe

NASA Astrophysics Data System (ADS)

Cooke, D. L.

2017-12-01

The Langmuir probe is one of the oldest plasma diagnostics, provided the plasma density and species temperature from analysis of a current-voltage curve as the voltage is swept over a practically chosen range. The analysis depends on a knowledge or theory of the many factors that influence the current-voltage curve including, probe shape, size, nearby perturbations, and the voltage reference. For applications in Low Earth Orbit, the Planar Langmuir Probe, PLP, is an attractive geometry because the ram ion current is very constant over many Volts of a sweep, allowing the ion density and electron temperature to be determined independently with the same instrument, at different points on the sweep. However, when the physical voltage reference is itself small and electrically floating as with a small spacecraft, the spacecraft and probe system become a double probe where the current collection theory depends on the interaction of the spacecraft with the plasma which is generally not as simple as the probe itself. The Sheath-less PLP, SPLP, interlaces on a single ram facing surface, two variably biased probe elements, broken into many small and intertwined segments on a scale smaller than the plasma Debye length. The SPLP is electrically isolated from the rest of the spacecraft. For relative bias potentials of a few volts, the ion current to all segments of each element will be constant, while the electron currents will vary as a function of the element potential and the electron temperature. Because the segments are small, intertwined, and floating, the assembly will always present the same floating potential to the plasma, with minimal growth as a function of voltage, thus sheath-less and still planar. This concept has been modelled with Nascap, and tested with a physical model inserted into a Low Earth Orbit-like chamber plasma. Results will be presented.

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

Zanchetta, Mario, E-mail: emodinacit@ulss15.pd.it; Rigatelli, Gianluca; Pedon, Luigi

To assess the accuracy and efficacy of intravascular ultrasound guidance obtained by an intracardiac ultrasound probe during complex aortic endografting. Between November 1999 and July 2002, 19 patients (5 female, 14 male; mean age 73.5 {+-} 2.1 years) underwent endovascular repair of thoracic (n = 10), complex abdominal (n = 6) and concomitant thoraco-abdominal (n = 3) aortic aneurysm. The most suitable size and configuration of the stent-graft were chosen on the basis of preoperative computed tomographic angiography (CTA) or magnetic resonance angiography (MRA). Intraoperative intravascular ultrasound imaging was obtained using a 9 Fr, 9 MHz intracardiac echocardiography (ICE) probe,more » 110 cm in length, inserted through a 10 Fr precurved long sheath. The endografts were deployed as planned by CTA or MRA. Before stent-graft deployment, the ICE probe allowed us to view the posterior aortic arch and descending thoraco-abdominal aorta without position-related artifacts, and to identify both sites of stent-graft positioning. After stent-graft deployment, the ICE probe allowed us to detect the need for additional modular components to internally reline the aorta in 11 patients, and to discover 2 incomplete graft expansions subsequently treated with adjunctive balloon angioplasty. In 1 patient, the ICE probe supported the decision that the patient was ineligible for the endovascular exclusion procedure. The ICE probe provides accurate information on the anatomy of the posterior aortic arch and thoracic and abdominal aortic aneurysms and a rapid identification of attachment sites and stent-graft pathology, allowing refinement and improvement of the endovascular strategy.« less

Ex vivo imaging of early dental caries within the interproximal space

NASA Astrophysics Data System (ADS)

Choo-Smith, Lin-P'ing; Hewko, Mark D.; Dufour, Marc L.; Fulton, Crystal; Qiu, Pingli; Gauthier, Bruno; Padioleau, Christian; Bisaillon, Charles-Etienne; Dong, Cecilia; Cleghorn, Blaine M.; Lamouche, Guy; Sowa, Michael G.

2009-02-01

Optical coherence tomography (OCT) is emerging as a technology that can potentially be used for the detection and monitoring of early dental enamel caries since it can provide high-resolution depth imaging of early lesions. To date, most caries detection optical technologies are well suited for examining caries at facial, lingual, incisal and occlusal surfaces. The approximal surfaces between adjacent teeth are difficult to examine due to lack of visual access and limited space for these new caries detection tools. Using a catheter-style probe developed at the NRC-Industrial Materials Institute, the probe was inserted into the interproximal space to examine the approximal surfaces with OCT imaging at 1310 nm. The probe was rotated continuously and translated axially to generate depth images in a spiral fashion. The probe was used in a mock tooth arch model consisting of extracted human teeth mounted with dental rope wax in their anatomically correct positions. With this ex vivo model, the probe provided images of the approximal surfaces revealing morphological structural details, regions of calculus, and especially regions of early dental caries (white spot lesions). Results were compared with those obtained from OCT imaging of individual samples where the approximal surfaces of extracted teeth are accessible on a lab-bench. Issues regarding access, regions of interest, and factors to be considered in an in vivo setting will be discussed. Future studies are aimed at using the probe in vivo with patient volunteers.

Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

DOEpatents

Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

1996-10-22

An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

DOEpatents

Majewski, Stanislaw; Kross, Brian J.; Zorn, Carl J.; Majewski, Lukasz A.

1996-01-01

An optimized examination system and method based on the Reverse Geometry X-Ray.RTM. (RGX.RTM.) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging.

Estimating thermal diffusivity and specific heat from needle probe thermal conductivity data

USGS Publications Warehouse

Waite, W.F.; Gilbert, L.Y.; Winters, W.J.; Mason, D.H.

2006-01-01

Thermal diffusivity and specific heat can be estimated from thermal conductivity measurements made using a standard needle probe and a suitably high data acquisition rate. Thermal properties are calculated from the measured temperature change in a sample subjected to heating by a needle probe. Accurate thermal conductivity measurements are obtained from a linear fit to many tens or hundreds of temperature change data points. In contrast, thermal diffusivity calculations require a nonlinear fit to the measured temperature change occurring in the first few tenths of a second of the measurement, resulting in a lower accuracy than that obtained for thermal conductivity. Specific heat is calculated from the ratio of thermal conductivity to diffusivity, and thus can have an uncertainty no better than that of the diffusivity estimate. Our thermal conductivity measurements of ice Ih and of tetrahydrofuran (THF) hydrate, made using a 1.6 mm outer diameter needle probe and a data acquisition rate of 18.2 pointss, agree with published results. Our thermal diffusivity and specific heat results reproduce published results within 25% for ice Ih and 3% for THF hydrate. ?? 2006 American Institute of Physics.

Mechanisms of Radiation-Induced Emesis

DTIC Science & Technology

1988-08-31

in these studies. The assistance of Mr. Laurie Duncan, Mr. Joseph Hutchinson, and Mr. Robert Bochniewicz in dosimetry and irradiaion is greatly...rectal probe (model 555) was inserted and centered in the port window to record the radiation exposure. TLDs were al~o munted, with three on both back...and stomach at the center and extremes of the port, and one on each side and on the dorsal surface of the head. Te TLDs were used only to independently

Left Ventricular, Systemic Arterial and Baroreflex Responses to Ketamine and TEE in Chronically Instrumented Monkeys

DTIC Science & Technology

2001-12-01

instrumented with a high fidelity, dual-sensor micromanometer to measure left ventricular and aortic pressure and a transit-time ultrasound probe to...isoflurane in 100% oxy- gen) prior to insertion of the high -fidelity pressure micromanome- ters during cardiac fluoroscopy. Once the micromanometer trans...and allowed to fully recover from the isoflurane seda- tion for a period of 60 min, during which blood pressure and aortic flow were monitored to ensure

Method for introducing unidirectional nested deletions

DOEpatents

Dunn, J.J.; Quesada, M.A.; Randesi, M.

1999-07-27

Disclosed is a method for the introduction of unidirectional deletions in a cloned DNA segment. More specifically, the method comprises providing a recombinant DNA construct comprising a DNA segment of interest inserted in a cloning vector. The cloning vector has an f1 endonuclease recognition sequence adjacent to the insertion site of the DNA segment of interest. The recombinant DNA construct is then contacted with the protein pII encoded by gene II of phage f1 thereby generating a single-stranded nick. The nicked DNA is then contacted with E. coli Exonuclease III thereby expanding the single-stranded nick into a single-stranded gap. The single-stranded gapped DNA is then contacted with a single-strand-specific endonuclease thereby producing a linearized DNA molecule containing a double-stranded deletion corresponding in size to the single-stranded gap. The DNA treated in this manner is then incubated with DNA ligase under conditions appropriate for ligation. Also disclosed is a method for producing single-stranded DNA probes. In this embodiment, single-stranded gapped DNA, produced as described above, is contacted with a DNA polymerase in the presence of labeled nucleotides to fill in the gap. This DNA is then linearized by digestion with a restriction enzyme which cuts outside the DNA segment of interest. The product of this digestion is then denatured to produce a labeled single-stranded nucleic acid probe. 1 fig.

Mechanical Validation of an MRI Compatible Stereotactic Neurosurgery Robot in Preparation for Pre-Clinical Trials.

PubMed

Nycz, Christopher J; Gondokaryono, Radian; Carvalho, Paulo; Patel, Nirav; Wartenberg, Marek; Pilitsis, Julie G; Fischer, Gregory S

2017-09-01

The use of magnetic resonance imaging (MRI) for guiding robotic surgical devices has shown great potential for performing precisely targeted and controlled interventions. To fully realize these benefits, devices must work safely within the tight confines of the MRI bore without negatively impacting image quality. Here we expand on previous work exploring MRI guided robots for neural interventions by presenting the mechanical design and assessment of a device for positioning, orienting, and inserting an interstitial ultrasound-based ablation probe. From our previous work we have added a 2 degree of freedom (DOF) needle driver for use with the aforementioned probe, revised the mechanical design to improve strength and function, and performed an evaluation of the mechanism's accuracy and effect on MR image quality. The result of this work is a 7-DOF MRI robot capable of positioning a needle tip and orienting it's axis with accuracy of 1.37 ± 0.06 mm and 0.79° ± 0.41°, inserting it along it's axis with an accuracy of 0.06 ± 0.07 mm , and rotating it about it's axis to an accuracy of 0.77° ± 1.31°. This was accomplished with no significant reduction in SNR caused by the robot's presence in the MRI bore, ≤ 10.3% reduction in SNR from running the robot's motors during a scan, and no visible paramagnetic artifacts.

Method for introducing unidirectional nested deletions

DOEpatents

Dunn, John J.; Quesada, Mark A.; Randesi, Matthew

1999-07-27

Disclosed is a method for the introduction of unidirectional deletions in a cloned DNA segment. More specifically, the method comprises providing a recombinant DNA construct comprising a DNA segment of interest inserted in a cloning vector, the cloning vector having an f1 endonuclease recognition sequence adjacent to the insertion site of the DNA segment of interest. The recombinant DNA construct is then contacted with the protein pII encoded by gene II of phage f1 thereby generating a single-stranded nick. The nicked DNA is then contacted with E. coli Exonuclease III thereby expanding the single-stranded nick into a single-stranded gap. The single-stranded gapped DNA is then contacted with a single-strand-specific endonuclease thereby producing a linearized DNA molecule containing a double-stranded deletion corresponding in size to the single-stranded gap. The DNA treated in this manner is then incubated with DNA ligase under conditions appropriate for ligation. Also disclosed is a method for producing single-stranded DNA probes. In this embodiment, single-stranded gapped DNA, produced as described above, is contacted with a DNA polymerase in the presence of labeled nucleotides to fill in the gap. This DNA is then linearized by digestion with a restriction enzyme which cuts outside the DNA segment of interest. The product of this digestion is then denatured to produce a labeled single-stranded nucleic acid probe.

Effects of interfaces on the thermal conductivity in Si/Si0.75Ge0.25 multilayer with varying Au layers

NASA Astrophysics Data System (ADS)

Hu, Yangsen; Wu, Zhenghua; Ye, Fengjie; Hu, Zhiyu

2018-02-01

The manoeuvre of thermal transport property across multilayer films with inserted metal layers through controlling the metal-nonmetal interfaces is of fundamental interest. In this work, amorphous Si/Si0.75Ge0.25 multilayer films inserted with varying Au layers were fabricated by magnetron sputtering. The structure and sharp interface of multilayers films were characterized by low angle x-ray diffraction (LAXRD), grazing incidence small angle x-ray scattering (GISAXS) and scanning electron microscopy (SEM). A differential 3ω method was applied to measure the effective thermal conductivity. The measurements show that thermal conductivity has changed as varying Au layers. Thermal conductivity increased from 0.94 to 1.31 Wm-1K-1 while Si0.75Ge0.25 layer was replaced by different Au layers, which was attributed to the strong electron-phonon coupling and interface thermal resistance in a metal-nonmetal multilayered system. Theoretical calculation combined with experimental results indicate that the thermal conductivity of the multilayer film could be facilely controlled by introducing different number of nanoconstructed metal-nonmetal interfaces, which provide a more insightful understanding of the thermal transport manipulation mechanism of the thin film system with inserting metal layers.

Characterization of terahertz waves on foreign materials of composite materials

NASA Astrophysics Data System (ADS)

Im, Kwang-Hee; Kim, Sun-Kyu; Chiou, Chien-Ping; Jung, Jong-An

2018-04-01

Carbon-fiber reinforced plastics (CFRP) are widely utilized due to their comparatively high performance in engineering structures. It is well understood that a nondestructive technique would be very beneficial. A new terahertz radiation has been recognized for its importance in technological applications. Recently, T-ray (terahertz ray) advances in technology and instrumentation have provided a probing field on the electromagnetic spectrum. In carbon composites, the penetration characterization of T-ray waves was fundamentally investigated in order to measure the painting thickness. Also, another study dealt with THz scan images of honeycomb sandwich composite panels using a refractive index (n), an absorption coefficient (α), the electrical conductivity of glass fiber embedded epoxy matrix composites, and carbon fiber reinforced plastics (CFRP) skin. For experiments, a method of detecting FRP composites with impact damage is presented, which utilizes aluminum wires intertwined with woven carbon fibers as they are inserted into the surface of the CFRP honeycomb sandwich panels. Intensive characterization of T-ray for the nondestructive evaluation (NDE) of carbon composite reinforced plastics (CFRP) composites is discussed in relation to the E-field influence with CFRP composite laminates.

Observations of structuring in the downstream region of a large spherical model in a laboratory simulated solar wind plasma

NASA Technical Reports Server (NTRS)

Intriligator, D. S.; Steele, G. R.

1982-01-01

The effects of inserting a spherical conducting model, large in comparison with the Debye length, into a free streaming high-energy 1 kV) unmagnetized hydrogen plasma are investigated in order to measure energies and compositions directly relevant to solar wind and astrophysical plasma phenomena. Holding the incident plasma parameters constant, transverse profiles of the net Langmuir probe current are plotted at various locations downstream in the model wake and are divided into three regions (the shadow, transition, and boundary). Results attributable to the use of a high-energy plasma show that enhancements in the shadow exist at downstream locations where the Mach ratio is less than one, and turbulence exists in the transition region on the shadow edges and outside in the boundary region. In addition, a small current enhancement is found in the boundary and can be attributed to the plasma/model interaction. It is concluded that many similar features observed by spacecraft downstream from planetary bodies are relatively permanent and are due to the intrinsic nature of the interaction between the solar wind plasma and the obstacle.

Carbon Nanotube Fiber Ionization Mass Spectrometry: A Fundamental Study of a Multi-Walled Carbon Nanotube Functionalized Corona Discharge Pin for Polycyclic Aromatic Hydrocarbons Analysis.

PubMed

Nahan, Keaton S; Alvarez, Noe; Shanov, Vesselin; Vonderheide, Anne

2017-11-01

Mass spectrometry continues to tackle many complicated tasks, and ongoing research seeks to simplify its instrumentation as well as sampling. The desorption electrospray ionization (DESI) source was the first ambient ionization source to function without extensive gas requirements and chromatography. Electrospray techniques generally have low efficiency for ionization of nonpolar analytes and some researchers have resorted to methods such as direct analysis in real time (DART) or desorption atmospheric pressure chemical ionization (DAPCI) for their analysis. In this work, a carbon nanotube fiber ionization (nanoCFI) source was developed and was found to be capable of solid phase microextraction (SPME) of nonpolar analytes as well as ionization and sampling similar to that of direct probe atmospheric pressure chemical ionization (DP-APCI). Conductivity and adsorption were maintained by utilizing a corona pin functionalized with a multi-walled carbon nanotube (MWCNT) thread. Quantitative work with the nanoCFI source with a designed corona discharge pin insert demonstrated linearity up to 0.97 (R 2 ) of three target PAHs with phenanthrene internal standard. Graphical Abstract ᅟ.

Carbon Nanotube Fiber Ionization Mass Spectrometry: A Fundamental Study of a Multi-Walled Carbon Nanotube Functionalized Corona Discharge Pin for Polycyclic Aromatic Hydrocarbons Analysis

NASA Astrophysics Data System (ADS)

Nahan, Keaton S.; Alvarez, Noe; Shanov, Vesselin; Vonderheide, Anne

2017-09-01

Mass spectrometry continues to tackle many complicated tasks, and ongoing research seeks to simplify its instrumentation as well as sampling. The desorption electrospray ionization (DESI) source was the first ambient ionization source to function without extensive gas requirements and chromatography. Electrospray techniques generally have low efficiency for ionization of nonpolar analytes and some researchers have resorted to methods such as direct analysis in real time (DART) or desorption atmospheric pressure chemical ionization (DAPCI) for their analysis. In this work, a carbon nanotube fiber ionization (nanoCFI) source was developed and was found to be capable of solid phase microextraction (SPME) of nonpolar analytes as well as ionization and sampling similar to that of direct probe atmospheric pressure chemical ionization (DP-APCI). Conductivity and adsorption were maintained by utilizing a corona pin functionalized with a multi-walled carbon nanotube (MWCNT) thread. Quantitative work with the nanoCFI source with a designed corona discharge pin insert demonstrated linearity up to 0.97 (R2) of three target PAHs with phenanthrene internal standard. [Figure not available: see fulltext.

Magnetic induction spectroscopy (MIS)-probe design for cervical tissue measurements.

PubMed

Wang, Jau-Yi; Healey, Timothy; Barker, Anthony; Brown, Brian; Monk, Chris; Anumba, Dilly

2017-05-01

Gradiometers have the advantage of increasing measuring sensitivity, which is particularly useful in magnetic induction spectroscopy (MIS) for bio-impedance measurements. Traditional gradiometers use a pair of field sensing coils equally distant and on opposite sides of a drive coil, which provides high immunity to interference. In this paper, a ferrite-cored coaxial gradiometer probe of 29 mm diameter has been developed for measuring the impedance spectra of cervical tissues in vivo. It consists of a ferrite rod with outer ferrite confinement screening in order to eliminate the signals from surrounding tissue. The magnetic screening efficiency was compared with an air-cored gradiometer probe. For both gradiometer probes, a drive coil and two sensing coils were wound on a borosilicate glass former aligned coaxially with two sensing coils equidistant from the drive coil. The signal sensitivity of those two MIS gradiometers has been measured using saline samples with a conductivity range between 0.1 and 1.1 S m -1 . Finite element methods using COMSOL Multiphysics have been used to simulate the distribution of sensitivity to conductivity over the face of each probe and with depth. The ferrite-cored probe has a sensitivity confined to the volume defined by the gap between the ferrite core and outer tube of ferrite while the air-cored probe without any magnetic shielding had a wide sensitivity over the face and the side of the probe. Four saline samples and one of distilled water with conductivities from 0.1 to 1.1 S m -1 have been used to make conductivity measurements at frequencies of 50 kHz, 100 kHz, and 300 kHz. The measurement accuracy of the air-cored MIS probe was 0.09 S m -1 at 50 kHz, improving to 0.05 S m -1 at 300 kHz. For the ferrite-cored MIS probe, the measurement accuracy was 0.28 S m -1 at 50 kHz, improving to 0.04 S m -1 at 300 kHz. In vivo measurements on human hand have been performed using both types of gradiometers and the conductivity is consistent with reported data.

Electric conductivity for laboratory and field monitoring of induced partial saturation (IPS) in sands

NASA Astrophysics Data System (ADS)

Kazemiroodsari, Hadi

Liquefaction is loss of shear strength in fully saturated loose sands caused by build-up of excess pore water pressure, during moderate to large earthquakes, leading to catastrophic failures of structures. Currently used liquefaction mitigation measures are often costly and cannot be applied at sites with existing structures. An innovative, practical, and cost effective liquefaction mitigation technique titled "Induced Partial Saturation" (IPS) was developed by researchers at Northeastern University. The IPS technique is based on injection of sodium percarbonate solution into fully saturated liquefaction susceptible sand. Sodium percarbonate dissolves in water and breaks down into sodium and carbonate ions and hydrogen peroxide which generates oxygen gas bubbles. Oxygen gas bubbles become trapped in sand pores and therefore decrease the degree of saturation of the sand, increase the compressibility of the soil, thus reduce its potential for liquefaction. The implementation of IPS required the development and validation of a monitoring and evaluation technique that would help ensure that the sands are indeed partially saturated. This dissertation focuses on this aspect of the IPS research. The monitoring system developed was based on using electric conductivity fundamentals and probes to detect the transport of chemical solution, calculate degree of saturation of sand, and determine the final zone of partial saturation created by IPS. To understand the fundamentals of electric conductivity, laboratory bench-top tests were conducted using electric conductivity probes and small specimens of Ottawa sand. Bench-top tests were used to study rate of generation of gas bubbles due to reaction of sodium percarbonate solution in sand, and to confirm a theory based on which degree of saturation were calculated. In addition to bench-top tests, electric conductivity probes were used in a relatively large sand specimen prepared in a specially manufactured glass tank. IPS was implemented in the prepared specimen to validate the numerical simulation model and explore the use of conductivity probes to detect the transport of chemical solution, estimate degree of saturation achieved due to injection of chemical solution, and evaluate final zone of partial saturation. The conductivity probe and the simulation results agreed well. To study the effect of IPS on liquefaction response of the sand specimen, IPS was implemented in a large (2-story high) sand specimen prepared in the laminar box of NEES Buffalo and then the specimen was subjected to harmonic shaking. Electric conductivity probes were used in the specimen treatment by controlling the duration and spacing of injection of the chemical solution, in monitoring the transport of chemical solution, in the estimation of zone of partial saturation achieved, and in the estimation of degree of saturation achieved due to implementation of IPS. The conductivity probes indicated partial saturation of the specimen. The shaking tests results confirmed the partial saturation state of the sand specimen. In addition, to the laboratory works, electric conductivity probes were used in field implementation of IPS in a pilot test at the Wildlife Liquefaction Array (WLA) of NEES UCSB site. The conductivity probes in the field test helped decide the optimum injection pressure, the injection tube spacing, and the degree of saturation that could be achieved in the field. The various laboratory and field tests confirmed that electric conductivity and the probes devised and used can be invaluable in the implementation of IPS, by providing information regarding transport of the chemical solution, the spacing of injection tubes, duration of injection, and the zone and degree of partial saturation caused by IPS.

Method and apparatus for assembling solid oxide fuel cells

DOEpatents

Szreders, Bernard E.; Campanella, Nicholas

1989-01-01

A plurality of jet air tubes are supported and maintained in a spaced matrix array by a positioning/insertion assembly for insertion in respective tubes of a solid oxide fuel cell (SOFC) in the assembly of an SOFC module. The positioning/insertion assembly includes a plurality of generally planar, elongated, linear vanes which are pivotally mounted at each end thereof to a support frame. The vanes, which each include a plurality of spaced slots along the facing edges thereof, may be pivotally displaced from a generally vertical orientation, wherein each jet air tube is positioned within and engaged by the aligned slots of a plurality of paired upper and lower vanes to facilitate their insertion in respective aligned SOFC tubes arranged in a matrix array, to an inclined orientation, wherein the jet air tubes may be removed from the positioning/insertion assembly after being inserted in the SOFC tubes. A rectangular compression assembly of adjustable size is adapted to receive and squeeze a matrix of SOFC tubes so as to compress the inter-tube nickel felt conductive pads which provide series/parallel electrical connection between adjacent SOFCs, with a series of increasingly larger retainer frames used to maintain larger matrices of SOFC tubes in position. Expansion of the SOFC module housing at the high operating temperatures of the SOFC is accommodated by conductive, flexible, resilient expansion, connector bars which provide support and electrical coupling at the top and bottom of the SOFC module housing.

DESIGN NOTE: The measurement of thermal conductivities of solid fruits and vegetables

NASA Astrophysics Data System (ADS)

Liang, Xin-Gang; Zhang, Yinping; Ge, Xinshi

1999-07-01

A thermal conductivity probe consisting of a heating cell, a thermocouple and a guard tube over the heating cell was developed and is described here. Analyses demonstrate that the guard tube acts as a thermal contact resistance. This resistance does not influence measurements of thermal conductivity significantly, but it must be considered in an accurate measurement of thermal diffusivity, especially when there is a gap between the heater and the guard tube. Calibration of the probe with glycerine in this work exhibits an accuracy of 1.4% for thermal conductivity measurements. The probe was used to measure the thermal conductivities of some solid fruits and vegetables. The sizes of both specimen and probe were analysed and their influences controlled to be under 1.0%. Each measurement was completed within two minutes and the temperature rise was less than under 6 °C. The water content of fruits and vegetables was found to be the dominant factor in determining their thermal conductivities. An empirical relationship between thermal conductivity and mass density is proposed based on the measurements. It is shown that this relation gives a deviation from experimental data of only 11%.

Effectiveness of a Wedge Probe to Measure Sonic Boom Signatures in a Supersonic Wind Tunnel

NASA Technical Reports Server (NTRS)

Wilcox, Floyd J., Jr.; Elmiligui, Alaa A.

2013-01-01

A wind tunnel investigation was conducted in the Langley Unitary Plan Wind Tunnel (UPWT) to determine the effectiveness of a wedge probe to measure sonic boom pressure signatures compared to a slender conical probe. A generic business jet model at a constant angle of attack and at a single model to probe separation distance was used to generate a sonic boom signature. Pressure signature data were acquired with both the wedge probe and a slender conical probe for comparison. The test was conducted at a Mach number of 2.0 and a free-stream unit Reynolds number of 2 million per foot. The results showed that the wedge probe was not effective in measuring the sonic boom pressure signature of the aircraft model in the supersonic wind tunnel. Data plots and a discussion of the results are presented. No tabulated data or flow visualization photographs are included.

Limitations of the widely used GAM42a and BET42a probes targeting bacteria in the Gammaproteobacteria radiation.

PubMed

Yeates, Christine; Saunders, Aaron M; Crocetti, Gregory R; Blackall, Linda L

2003-05-01

The 23S rRNA-targeted probes GAM42a and BET42a provided equivocal results with the uncultured gammaproteobacterium 'Candidatus Competibacter phosphatis' where some cells bound GAM42a and other cells bound BET42a in fluorescence in situ hybridization (FISH) experiments. Probes GAM42a and BET42a span positions 1027-1043 in the 23S rRNA and differ from each other by one nucleotide at position 1033. Clone libraries were prepared from PCR products spanning the 16S rRNA genes, intergenic spacer region and 23S rRNA genes from two mixed cultures enriched in 'Candidatus C. phosphatis'. With individual clone inserts, the 16S rDNA portion was used to confirm the source organism as 'Candidatus C. phosphatis' and the 23S rDNA portion was used to determine the sequence of the GAM42a/BET42a probe target region. Of the 19 clones sequenced, 8 had the GAM42a probe target (T at position 1033) and 11 had G at position 1033, the only mismatch with GAM42a. However, none of the clones had the BET42a probe target (A at 1033). Non-canonical base-pairing between the 23S rRNA of 'Candidatus C. phosphatis' with G at position 1033 and GAM42a (G-A) or BET42a (G-T) is likely to explain the probing anomalies. A probe (GAM42_C1033) was optimized for use in FISH, targeting cells with G at position 1033, and was found to highlight not only some 'Candidatus C. phosphatis' cells, but also other bacteria. This demonstrates that there are bacteria in addition to 'Candidatus C. phosphatis' with the GAM42_C1033 probe target and not the BET42a or GAM42a probe target.

Apparatus for detecting alpha radiation in difficult access areas

DOEpatents

Steadman, P.; MacArthur, D.W.

1997-09-02

An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure is disclosed. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure. A voltage source is connected between the indicator means and the electrically conductive enclosure for creating an electric field between the electrically conductive expandable electrode and the enclosure. 4 figs.

The Tgm9-induced indexed insertional mutant collection to conduct community-based reverse genetics studies in soybean

USDA-ARS?s Scientific Manuscript database

Until now, functional analyses of soybean genes have been very arduous because of the lack of a rapid transformation procedure. Recently identified the active endogenous type II transposable element, Tgm9, excises from insertion sites and restores wild-type phenotypes. Thus, this element provides a ...

Insert Design and Manufacturing for Foam-Core Composite Sandwich Structures

NASA Astrophysics Data System (ADS)

Lares, Alan

Sandwich structures have been used in the aerospace industry for many years. The high strength to weight ratios that are possible with sandwich constructions makes them desirable for airframe applications. While sandwich structures are effective at handling distributed loads such as aerodynamic forces, they are prone to damage from concentrated loads at joints or due to impact. This is due to the relatively thin face-sheets and soft core materials typically found in sandwich structures. Carleton University's Uninhabited Aerial Vehicle (UAV) Project Team has designed and manufactured a UAV (GeoSury II Prototype) which features an all composite sandwich structure fuselage structure. The purpose of the aircraft is to conduct geomagnetic surveys. The GeoSury II Prototype serves as the test bed for many areas of research in advancing UAV technologies. Those areas of research include: low cost composite materials manufacturing, geomagnetic data acquisition, obstacle detection, autonomous operations and magnetic signature control. In this thesis work a methodology for designing and manufacturing inserts for foam-core sandwich structures was developed. The results of this research work enables a designer wishing to design a foam-core sandwich airframe structure, a means of quickly manufacturing optimized inserts for the safe introduction of discrete loads into the airframe. The previous GeoSury II Prototype insert designs (v.1 & v.2) were performance tested to establish a benchmark with which to compare future insert designs. Several designs and materials were considered for the new v.3 inserts. A plug and sleeve design was selected, due to its ability to effectively transfer the required loads to the sandwich structure. The insert material was chosen to be epoxy, reinforced with chopped carbon fibre. This material was chosen for its combination of strength, low mass and also compatibility with the face-sheet material. The v.3 insert assembly is 60% lighter than the previous insert designs. A casting process for manufacturing the v.3 inserts was developed. The developed casting process, when producing more than 13 inserts, becomes more economical than machining. An exploratory study was conducted looking at the effects of dynamic loading on the v.3 insert performance. The results of this study highlighted areas for improving dynamic testing of foam-core sandwich structure inserts. Correlations were developed relating design variables such as face-sheet thickness and insert diameter to a failure load for different load cases. This was done through simulations using Computer Aided Engineering (CAE) software, and experimental testing. The resulting correlations were integrated into a computer program which outputs the required insert dimensions given a set of design parameters, and load values.

Correlation of oxygenation and perfusion sensitive MRI with invasive micro probe measurements in healthy mice brain.

PubMed

Sedlacik, Jan; Reitz, Matthias; Bolar, Divya S; Adalsteinsson, Elfar; Schmidt, Nils O; Fiehler, Jens

2015-03-01

The non-invasive assessment of (patho-)physiological parameters such as, perfusion and oxygenation, is of great importance for the characterization of pathologies e.g., tumors, which may be helpful to better predict treatment response and potential outcome. To better understand the influence of physiological parameters on the investigated oxygenation and perfusion sensitive MRI methods, MRI measurements were correlated with subsequent invasive micro probe measurements during free breathing conditions of air, air+10% CO2 and 100% O2 in healthy mice brain. MRI parameters were the irreversible (R2), reversible (R2') and effective (R2*) transverse relaxation rates, venous blood oxygenation level assessed by quantitative blood oxygenation level dependent (qBOLD) method and cerebral blood flow (CBF) assessed by arterial spin labeling (ASL) using a 7 T small animal MRI scanner. One to two days after MRI, tissue perfusion and pO2 were measured by Laser-Doppler flowmetry and fluorescence quenching micro probes, respectively. The tissue pO2 values were converted to blood oxygen saturation by using the Hill equation. The animals were anesthetized by intra peritoneal injection of ketamine-xylazine-acepromazine (10-2-0.3 mg/ml · kg). Results for normal/hypercapnia/hyperoxia conditions were: R2[s(∧)-1] = 20.7/20.4/20.1, R2*[s(∧)-1] = 31.6/29.6/25.9, R2'[s-(∧)1] = 10.9/9.2/5.7, qBOLD venous blood oxygenation level = 0.43/0.51/0.56, CBF[ml · min(∧)-1 · 100 g(∧)-1] = 70.6/105.5/81.8, Laser-Doppler flowmetry[a.u.] = 89.2/120.2/90.6 and pO2[mmHg] = 6.3/32.3/46.7. All parameters were statistically significantly different with P < 0.001 between all breathing conditions. All MRI and the corresponding micro probe measurements were also statistically significantly (P ≤ 0.03) correlated with each other. However, converting the tissue pO2 to blood oxygen saturation = 0.02/0.34/0.63, showed only very limited agreement with the qBOLD venous blood oxygenation level. We found good correlation between MRI and micro probe measurements. However, direct conversion of tissue pO2 to blood oxygen saturation by using the Hill equation is very limited. Furthermore, adverse effects of anesthesia and trauma due to micro probe insertion are strong confounding factors and need close attention for study planning and conduction of experiments. Investigation of the correlation of perfusion and oxygenation sensitive MRI methods with micro probe measurements in pathologic tissue such as tumors is now of compelling interest. Copyright © 2014. Published by Elsevier GmbH.

New concepts of fluorescent probes for specific detection of DNA sequences: bis-modified oligonucleotides in excimer and exciplex detection.

PubMed

Gbaj, A; Bichenkova, Ev; Walsh, L; Savage, He; Sardarian, Ar; Etchells, Ll; Gulati, A; Hawisa, S; Douglas, Kt

2009-12-01

The detection of single base mismatches in DNA is important for diagnostics, treatment of genetic diseases, and identification of single nucleotide polymorphisms. Highly sensitive, specific assays are needed to investigate genetic samples from patients. The use of a simple fluorescent nucleoside analogue in detection of DNA sequence and point mutations by hybridisation in solution is described in this study. The 5'-bispyrene and 3'-naphthalene oligonucleotide probes form an exciplex on hybridisation to target in water and the 5'-bispyrene oligonucleotide alone is an adequate probe to determine concentration of target present. It was also indicated that this system has a potential to identify mismatches and insertions. The aim of this work was to investigate experimental structures and conditions that permit strong exciplex emission for nucleic acid detectors, and show how such exciplexes can register the presence of mismatches as required in SNP analysis. This study revealed that the hybridisation of 5'-bispyrenyl fluorophore to a DNA target results in formation of a fluorescent probe with high signal intensity change and specificity for detecting a complementary target in a homogeneous system. Detection of SNP mutations using this split-probe system is a highly specific, simple, and accessible method to meet the rigorous requirements of pharmacogenomic studies. Thus, it is possible for the system to act as SNP detectors and it shows promise for future applications in genetic testing.

Integrated OCT-US catheter for detection of cancer in the gastrointestinal tract

NASA Astrophysics Data System (ADS)

Li, Jiawen; Ma, Teng; Cummins, Thomas; Shung, K. Kirk; Van Dam, Jacques; Zhou, Qifa; Chen, Zhongping

2015-03-01

Gastrointestinal tract cancer, the most common type of cancer, has a very low survival rate, especially for pancreatic cancer (five year survival rate of 5%) and bile duct cancer (five year survival rate of 12%). Here, we propose to use an integrated OCT-US catheter for cancer detection. OCT is targeted to acquire detailed information, such as dysplasia and neoplasia, for early detection of tumors. US is used for staging cancers according to the size of the primary tumor and whether or not it has invaded lymph nodes and other parts of the body. Considering the lumen size of the GI tract, an OCT system with a long image range (>10mm) and a US imaging system with a center frequency at 40MHz (penetration depth > 5mm) were used. The OCT probe was also designed for long-range imaging. The side-view OCT and US probes were sealed inside one probe cap piece and one torque coil and became an integrated probe. This probe was then inserted into a catheter sheath which fits in the channel of a duodenoscope and is able to be navigated smoothly into the bile duct by the elevator of the duodenoscope. We have imaged 5 healthy and 2 diseased bile ducts. In the OCT images, disorganized layer structures and heterogeneous regions demonstrated the existence of tumors. Micro-calcification can be observed in the corresponding US images.

Optimisation of readout performance of phase-change probe memory in terms of capping layer and probe tip

NASA Astrophysics Data System (ADS)

Wang, Lei; Wright, C. David; Aziz, Mustafa. M.; Yang, Ci Hui; Yang, Guo Wei

2014-11-01

The capping layer and the probe tip that serve as the protective layer and the recording tool, respectively, for phase-change probe memory play an important role on the writing performance of phase-change probe memory, thus receiving considerable attention. On the other hand, their influence on the readout performance of phasechange probe memory has rarely been reported before. A three-dimensional parametric study based on the Laplace equation was therefore conducted to investigate the effect of the capping layer and the probe tip on the resulting reading contrast for the two cases of reading a crystalline bit from an amorphous matrix and reading an amorphous bit from a crystalline matrix. The results indicated that a capping layer with a thickness of 2 nm and an electrical conductivity of 50 Ω-1m-1 is able to provide an appropriate reading contrast for both the cases, while satisfying the previous writing requirement, particularly with the assistance of a platinum silicide probe tip.

Acute myeloid leukaemia (FAB AML-M4Eo) with cryptic insertion of cbfb resulting in cbfb-Myh11 fusion.

PubMed

Douet-Guilbert, Nathalie; Chauveau, Aurelie; Gueganic, Nadia; Guillerm, Gaëlle; Tous, Corine; Le Bris, Marie-Josee; Basinko, Audrey; Morel, Frederic; Ugo, Valerie; De Braekeleer, Marc

2017-09-01

Inv(16)(p13q22) and t(16;16)(p13;q22) are cytogenetic hallmarks of acute myelomonoblastic leukaemia, most of them associated with abnormal bone marrow eosinophils [acute myeloid leukaemia French-American-British classification M4 with eosinophilia (FAB AML-M4Eo)] and a relatively favourable clinical course. They generate a 5'CBFB-3'MYH11 fusion gene. However, in a few cases, although RT-PCR identified a CBFB-MYH11 transcript, normal karyotype and/or fluorescent in situ hybridization (FISH) analyses using commercially available probes are found. We identified a 32-year-old woman with AML-M4Eo and normal karyotype and FISH results. Using two libraries of Bacterial Artificial Chromosome clones on 16p13 and 16q22, FISH analyses identified an insertion of 16q22 material in band 16p13, generating a CBFB-MYH11 type A transcript. Although very rare, insertions should be searched for in patients with discordant cytological and cytogenetic features because of the therapeutic consequences. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A Particle and Energy Balance Model of the Orificed Hollow Cathode

NASA Technical Reports Server (NTRS)

Domonkos, Matthew T.

2002-01-01

A particle and energy balance model of orificed hollow cathodes was developed to assist in cathode design. The model presented here is an ensemble of original work by the author and previous work by others. The processes in the orifice region are considered to be one of the primary drivers in determining cathode performance, since the current density was greatest in this volume (up to 1.6 x 10(exp 8) A/m2). The orifice model contains comparatively few free parameters, and its results are used to bound the free parameters for the insert model. Next, the insert region model is presented. The sensitivity of the results to the free parameters is assessed, and variation of the free parameters in the orifice dominates the calculated power consumption and plasma properties. The model predictions are compared to data from a low-current orificed hollow cathode. The predicted power consumption exceeds the experimental results. Estimates of the plasma properties in the insert region overlap Langmuir probe data, and the predicted orifice plasma suggests the presence of one or more double layers. Finally, the model is used to examine the operation of higher current cathodes.

Origins of Protons in C-H Bond Insertion Products of Phenols: Proton-Self-Sufficient Function via Water Molecules.

PubMed

Luo, Zhoujie; Gao, Ya; Zhu, Tong; Zhang, John Zenghui; Xia, Fei

2017-08-31

Water molecules can serve as proton shuttles for proton transfer in the C-H bond insertion reactions catalyzed by transition metal complexes. Recently, the control experiments performed for C-H bond insertion of phenol and anisol by gold carbenes show that large discrepancy exists in the yields of hydrogenated and deuterated products. Thus, we conducted a detailed theoretical analysis on the function of water molecules in the C-H bond insertion reactions. The comparison of calculated results and control experiments indicates that the solution water molecules play a crucial role of proton shuttle in C-H bond insertion. In particular, it was found that the hydroxyl groups in phenols were capable of donating protons via water shuttles for the production of C-H products, which had a substantial influence on the yields of inserted products. The hydroxyl groups instead of C-H bonds in phenols function like "proton reservoirs" in the C-H bond insertion, which we call the "proton self-sufficient" (PSS) function of phenol. The PSS function of phenol indicates that the substrates with and without proton reservoirs will lead to different C-H bond insertion products.

Overnight Changes Recorded by Phoenix Conductivity Probe

NASA Image and Video Library

2008-12-15

This graph presents simplified data from overnight measurements by the Thermal and Electrical Conductivity Probe on NASA Phoenix Mars Lander from noon of the mission 70th Martian day, or sol, to noon the following sol Aug. 5 to Aug. 6, 2008.

Two-phase flow measurements with advanced instrumented spool pieces and local conductivity probes

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

Turnage, K.G.; Davis, C.E.

1979-01-01

A series of two-phase, air-water and steam-water tests performed with instrumented spool pieces and with conductivity probes obtained from Atomic Energy of Canada, Ltd. is described. The behavior of the three-beam densitometer, turbine meter, and drag flowmeter is discussed in terms of two-phase models. Application of some two-phase mass flow models to the recorded spool piece data is made and preliminary results are shown. Velocity and void fraction information derived from the conductivity probes is presented and compared to velocities and void fractions obtained using the spool piece instrumentation.

Mass Spec Studio for Integrative Structural Biology

PubMed Central

Rey, Martial; Sarpe, Vladimir; Burns, Kyle; Buse, Joshua; Baker, Charles A.H.; van Dijk, Marc; Wordeman, Linda; Bonvin, Alexandre M.J.J.; Schriemer, David C.

2015-01-01

SUMMARY The integration of biophysical data from multiple sources is critical for developing accurate structural models of large multiprotein systems and their regulators. Mass spectrometry (MS) can be used to measure the insertion location for a wide range of topographically sensitive chemical probes, and such insertion data provide a rich, but disparate set of modeling restraints. We have developed a software platform that integrates the analysis of label-based MS data with protein modeling activities (Mass Spec Studio). Analysis packages can mine any labeling data from any mass spectrometer in a proteomics-grade manner, and link labeling methods with data-directed protein interaction modeling using HADDOCK. Support is provided for hydrogen/ deuterium exchange (HX) and covalent labeling chemistries, including novel acquisition strategies such as targeted HX-tandem MS (MS2) and data-independent HX-MS2. The latter permits the modeling of highly complex systems, which we demonstrate by the analysis of microtubule interactions. PMID:25242457

Cardiovascular results from a rhesus monkey flown aboard the Cosmos 1514 spaceflight

NASA Technical Reports Server (NTRS)

Sandler, H.; Hines, J.; Benjamin, B. A.; Halpryn, B. M.; Krotov, V. P.

1987-01-01

The results of the Cosmos 1514 cardiovascular experiment, in which the blood flow to the head and the carotid pressure of a rhesus monkey were measured during the 5-d spaceflight, are reported. A single cylindrical probe containing both pressure and flow transducers was chronically implanted as a cuff around the left common carotid artery; measurements were obtained for 4 min every 2 h and compared to identical recordings obtained during a preflight control period and during 12 h on a launch pad. Immediately on its insertion into orbit, mean arterial pressure increased by 10 percent and has maintained a 16-27 percent increase over the first few hours of flight before returning to baseline level. Blood flow showed reciprocal changes to pressure on orbital insertion. Cardiovascular system changes persisted into the second day of flight, with the signs of adaptation appearing on days 3-5.

Study on Quality of IUD Services Provided by Trained Professionals at Teaching Institutes.

PubMed

Prasad, Noopur; Jain, M L; Meena, B S

2018-06-01

Access the completeness in IUD services provided by trained professionals and find out the weak links. Study was conducted on 100 IUD trained professionals of tertiary care hospital and nursing teaching institute. All were given questionnaire that was duly filled by them. Data obtained were analysed. Protocols of case selection, pre-insertion counselling, insertion process and follow-up were assessed. All the four criteria were assessed on score of ten. Study group could not get ten points under any of the set criteria. Average of 53% case selection, 31.4% pre-insertion counselling, 42.5% insertion protocols and 46.1% follow-up counselling criteria were observed by study group. Highest compliance of protocols was seen among postgraduate students. Although IUD training is given to all medical professionals and IUD facility is available up to subcentres but the study shows that completeness in services is still lacking. Ensuring ideal place for IUD insertion, proper case selection, use of specific instruments for insertion and observance of insertion protocols are very vital for the success of IUD.

Anatomic variations found on dissection of depressor septi nasi muscles in cadavers.

PubMed

Ebrahimi, Ali; Nejadsarvari, Nasrin; Motamedi, Mohammad Hosein Kalantar; Rezaee, Maryam; Koushki, Ehsan Shams

2012-01-01

To define variations of the depressor septi muscle in Iranians; to provide guidance for modification of this muscle during rhinoplasty in patients with an active muscle and short upper lip; and to correlate our findings with our clinical experience to develop the applied algorithms. This study was conducted by dissecting 82 depressor septi nasi muscles in 41 Iranian cadavers. Origin and insertion points of each muscle were studied. Three variations were found in muscle insertion points: periosteal, orbicularis oris, and floating. Forty-four percent of the muscles were inserted into the periosteum of the maxilla (n = 36); 39% of muscles were inserted into the orbicularis oris muscle (n = 32); and 17% were diminutive or floating (n = 14). Periosteal insertion was thicker and stronger than the other variations. In all cadavers, the origin of the muscle was medial crus of alar cartilage and caudal of the nasal septum. This cadaveric dissection showed that the percentage of depressor septi muscle insertions is not similar to that found in other surveys. In this study, periosteal insertion of the depressor septi muscle was the most common variation.

Influence of probe geometry on pitot-probe displacement in supersonic turbulent flow

NASA Technical Reports Server (NTRS)

Allen, J. M.

1975-01-01

An experiment was conducted to determine the varying effects of six different probe-tip and support-shaft configurations on pitot tube displacement. The study was stimulated by discrepancies between supersonic wind-tunnel tests conducted by Wilson and Young (1949) and Allen (1972). Wilson (1973) had concluded that these discrepancies were caused by differences in probe geometry. It is shown that in fact, no major differences in profiles of streamwise velocity over streamwise velocity at boundary-layer edge vs normal coordinate over boundary-layer total thickness result from geometry. The true cause of the discrepancies, however, remains to be discovered.

Fiberoptic probe and system for spectral measurements

DOEpatents

Dai, Sheng; Young, Jack P.

1998-01-01

A fused fiberoptic probe, a system, method and embodiments thereof for conducting spectral measurements are disclosed. The fused fiberoptic probe comprises a probe tip having a specific geometrical configuration, an exciting optical fiber and at least one collection optical fiber fused within a housing, preferrably silica. The specific geometrical configurations in which the probe tip can be shaped include a slanted probe tip with an angle greater than 0.degree., an inverted cone-shaped probe tip, and a lens head.

Construction, in vitro and in vivo evaluation of an in-house conductance meter for measurement of skin hydration.

PubMed

Hamed, Saja H; Altrabsheh, Bilal; Assa'd, Tareq; Jaradat, Said; Alshra'ah, Mohammad; Aljamal, Abdulfattah; Alkhatib, Hatim S; Almalty, Abdul-Majeed

2012-12-01

Different probes are used in dermato-cosmetic research to measure the electrical properties of the skin. The principle governing the choice of the geometry and material of the measuring probe is not well defined in the literature and some device's measuring principles are not accessible for the scientific community. The purpose of this work was to develop a simple inexpensive conductance meter for the objective in vivo evaluation of skin hydration. The conductance meter probe was designed using the basic equation governing wave propagation along Transverse Electromagnetic transmission lines. It consisted of two concentric copper circular electrodes printed on FR4 dielectric material. The performance of the probe was validated by evaluating its measurement depth, its ability to monitor in vitro water sorption-desorption and in vivo skin hydration effect in comparison to that of the Corneometer CM 825. The measurement depth of the probe, 15 μm, was comparable to that of CM 825. The in vitro readings of the probe correlated strongly with the amount of water adsorbed on filter paper. Skin hydration after application of a moisturizer was monitored effectively by the new probe with good correlation to the results of CM 825. In conclusion, a simple probe for evaluating skin hydration was made from off-the-shelf materials and its performance was validated in comparison to a commercially available probe. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Decrypting protein insertion through the translocon with free-energy calculations.

PubMed

Gumbart, James C; Chipot, Christophe

2016-07-01

Protein insertion into a membrane is a complex process involving numerous players. The most prominent of these players is the Sec translocon complex, a conserved protein-conducting channel present in the cytoplasmic membrane of bacteria and the membrane of the endoplasmic reticulum in eukaryotes. The last decade has seen tremendous leaps forward in our understanding of how insertion is managed by the translocon and its partners, coming from atomic-detailed structures, innovative experiments, and well-designed simulations. In this review, we discuss how experiments and simulations, hand-in-hand, teased out the secrets of the translocon-facilitated membrane insertion process. In particular, we focus on the role of free-energy calculations in elucidating membrane insertion. Amazingly, despite all its apparent complexity, protein insertion into membranes is primarily driven by simple thermodynamic and kinetic principles. This article is part of a Special Issue entitled: Membrane proteins edited by J.C. Gumbart and Sergei Noskov. Copyright © 2016 Elsevier B.V. All rights reserved.

Insertional Inactivation of Genes Responsible for the d-Alanylation of Lipoteichoic Acid in Streptococcus gordonii DL1 (Challis) Affects Intrageneric Coaggregations

PubMed Central

Clemans, Daniel L.; Kolenbrander, Paul E.; Debabov, Dmitri V.; Zhang, Qunying; Lunsford, R. Dwayne; Sakone, Holly; Whittaker, Catherine J.; Heaton, Michael P.; Neuhaus, Francis C.

1999-01-01

Most human oral viridans streptococci participate in intrageneric coaggregations, the cell-to-cell adherence among genetically distinct streptococci. Two genes relevant to these intrageneric coaggregations were identified by transposon Tn916 mutagenesis of Streptococcus gordonii DL1 (Challis). A 626-bp sequence flanking the left end of the transposon was homologous to dltA and dltB of Lactobacillus rhamnosus ATCC 7469 (formerly called Lactobacillus casei). A 60-kb probe based on this flanking sequence was used to identify the homologous DNA in a fosmid library of S. gordonii DL1. This DNA encoded d-alanine-d-alanyl carrier protein ligase that was expressed in Escherichia coli from the fosmid clone. The cloned streptococcal dltA was disrupted by inserting an ermAM cassette, and then it was linearized and transformed into S. gordonii DL1 for allelic replacement. Erythromycin-resistant transformants containing a single insertion in dltA exhibited a loss of d-alanyl esters in lipoteichoic acid (LTA) and a loss of intrageneric coaggregation. This phenotype was correlated with the loss of a 100-kDa surface protein reported previously to be involved in mediating intrageneric coaggregation (C. J. Whittaker, D. L. Clemans, and P. E. Kolenbrander, Infect. Immun. 64:4137–4142, 1996). The mutants retained the parental ability to participate in intergeneric coaggregation with human oral actinomyces, indicating the specificity of the mutation in altering intrageneric coaggregations. The mutants were altered morphologically and exhibited aberrant cell septa in a variety of pleomorphs. The natural DNA transformation frequency was reduced 10-fold in these mutants. Southern analysis of chromosomal DNAs from various streptococcal species with the dltA probe revealed the presence of this gene in most viridans streptococci. Thus, it is hypothesized that d-alanyl LTA may provide binding sites for the putative 100-kDa adhesin and scaffolding for the proper presentation of this adhesin to mediate intrageneric coaggregation. PMID:10225909

Insertional inactivation of genes responsible for the D-alanylation of lipoteichoic acid in Streptococcus gordonii DL1 (Challis) affects intrageneric coaggregations.

PubMed

Clemans, D L; Kolenbrander, P E; Debabov, D V; Zhang, Q; Lunsford, R D; Sakone, H; Whittaker, C J; Heaton, M P; Neuhaus, F C

1999-05-01

Most human oral viridans streptococci participate in intrageneric coaggregations, the cell-to-cell adherence among genetically distinct streptococci. Two genes relevant to these intrageneric coaggregations were identified by transposon Tn916 mutagenesis of Streptococcus gordonii DL1 (Challis). A 626-bp sequence flanking the left end of the transposon was homologous to dltA and dltB of Lactobacillus rhamnosus ATCC 7469 (formerly called Lactobacillus casei). A 60-kb probe based on this flanking sequence was used to identify the homologous DNA in a fosmid library of S. gordonii DL1. This DNA encoded D-alanine-D-alanyl carrier protein ligase that was expressed in Escherichia coli from the fosmid clone. The cloned streptococcal dltA was disrupted by inserting an ermAM cassette, and then it was linearized and transformed into S. gordonii DL1 for allelic replacement. Erythromycin-resistant transformants containing a single insertion in dltA exhibited a loss of D-alanyl esters in lipoteichoic acid (LTA) and a loss of intrageneric coaggregation. This phenotype was correlated with the loss of a 100-kDa surface protein reported previously to be involved in mediating intrageneric coaggregation (C. J. Whittaker, D. L. Clemans, and P. E. Kolenbrander, Infect. Immun. 64:4137-4142, 1996). The mutants retained the parental ability to participate in intergeneric coaggregation with human oral actinomyces, indicating the specificity of the mutation in altering intrageneric coaggregations. The mutants were altered morphologically and exhibited aberrant cell septa in a variety of pleomorphs. The natural DNA transformation frequency was reduced 10-fold in these mutants. Southern analysis of chromosomal DNAs from various streptococcal species with the dltA probe revealed the presence of this gene in most viridans streptococci. Thus, it is hypothesized that D-alanyl LTA may provide binding sites for the putative 100-kDa adhesin and scaffolding for the proper presentation of this adhesin to mediate intrageneric coaggregation.

A cool approach to reducing electrode-induced trauma: Localized therapeutic hypothermia conserves residual hearing in cochlear implantation.

PubMed

Tamames, Ilmar; King, Curtis; Bas, Esperanza; Dietrich, W Dalton; Telischi, Fred; Rajguru, Suhrud M

2016-09-01

The trauma caused during cochlear implant insertion can lead to cell death and a loss of residual hair cells in the cochlea. Various therapeutic approaches have been studied to prevent cochlear implant-induced residual hearing loss with limited success. In the present study, we show the efficacy of mild to moderate therapeutic hypothermia of 4 to 6 °C applied to the cochlea in reducing residual hearing loss associated with the electrode insertion trauma. Rats were randomly distributed in three groups: control contralateral cochleae, normothermic implanted cochleae and hypothermic implanted cochleae. Localized hypothermia was delivered to the middle turn of the cochlea for 20 min before and after implantation using a custom-designed probe perfused with cooled fluorocarbon. Auditory brainstem responses (ABRs) were recorded to assess the hearing function prior to and post-cochlear implantation at various time points up to 30 days. At the conclusion of the trials, inner ears were harvested for histology and cell count. The approach was extended to cadaver temporal bones to study the potential surgical approach and efficacy of our device. In this case, the hypothermia probe was placed next to the round window niche via the facial recess or a myringotomy. A significant loss of residual hearing was observed in the normothermic implant group. Comparatively, the residual hearing in the cochleae receiving therapeutic hypothermia was significantly conserved. Histology confirmed a significant loss of outer hair cells in normothermic cochleae receiving the surgical trauma when compared to the hypothermia treated group. In human temporal bones, a controlled and effective cooling of the cochlea was achieved using our approach. Collectively, these results suggest that therapeutic hypothermia during cochlear implantation may reduce traumatic effects of electrode insertion and improve conservation of residual hearing. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Interface engineering in epitaxial growth of layered oxides via a conducting layer insertion

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

Yun, Yu; Meng, Dechao; Wang, Jianlin

2015-07-06

There is a long-standing challenge in the fabrication of layered oxide epitaxial films due to their thermodynamic phase-instability and the large stacking layer number. Recently, the demand for high-quality thin films is strongly pushed by their promising room-temperature multiferroic properties. Here, we find that by inserting a conducting and lattice matched LaNiO{sub 3} buffer layer, high quality m = 5 Bi{sub 6}FeCoTi{sub 3}O{sub 18} epitaxial films can be fabricated using the laser molecular beam epitaxy, in which the atomic-scale sharp interface between the film and the metallic buffer layer explains the enhanced quality. The magnetic and ferroelectric properties of the high qualitymore » Bi{sub 6}FeCoTi{sub 3}O{sub 18} films are studied. This study demonstrates that insertion of the conducting layer is a powerful method in achieving high quality layered oxide thin films, which opens the door to further understand the underline physics and to develop new devices.« less

In Vitro Measurement Of Insertion Torque, Removal Torque And Resonance Frequency Analysis Of Implants Placed Into Simulated Bony Defects

DTIC Science & Technology

2014-05-14

2002). "Healing after standardized clinical probing of perlimlant soft tissue seal; a histomorphometric study in dogs." Clinical oral Implants...implant and periodontal tissues . A study in the beagle dog." Clin Oral Implants Res3(1): 9-16. Luterbacher, S., Mayfield, L. (2000). "Diagnostic...encapsulation around the implant and soft tissue . This type of healing and encapsulation led to inflammation, infection, mobility and failure of the

Strike Rescue - Are We on the Right Path?

DTIC Science & Technology

1990-11-16

Vietnam, a pilot had more to worry about than just enemy SAM’s and flak. More than one POW was bagged by his own weapon system. CDR Jeremiah A. Denton ...Squadron (SOS) based at Eglin AFB in Florida. The MH-60G features an air-to-air refueling probe and auxiliary internal fuel tanks. This allows for 4.5...missions in a contaminated NBC environment. Specifically, let’s consider SC𔄁 missions to rescue "human shields" that Hussein has inserted to protect

Services to Operate and Maintain Walter Reed Army Institute of Research’s (WRAIR) Microwave Facility.

DTIC Science & Technology

1994-06-20

Sixty-four day old rats were euthanized individually in a polycarbonate cage with carbon dioxide from a 100 % carbon dioxide cylinder. Eyes were removed...grams were used. Rats were euthanized with carbon dioxide . A thermistor based temperature probe (Yellow Spring Instruments, YSI 423) was inserted 5 cm...gals). This has been a necessary procedure which evacuates carbon from the oil which in turn will build-up on the HV components and conductors in the

The design and instrumentation of the Purdue annular cascade facility with initial data acquisition and analysis

NASA Technical Reports Server (NTRS)

Stauter, R. C.; Fleeter, S.

1982-01-01

Three dimensional aerodynamic data, required to validate and/or indicate necessary refinements to inviscid and viscous analyses of the flow through turbomachine blade rows, are discussed. Instrumentation and capabilities for pressure measurement, probe insertion and traversing, and flow visualization are reviewed. Advanced measurement techniques including Laser Doppler Anemometers, are considered. Data processing is reviewed. Predictions were correlated with the experimental data. A flow visualization technique using helium filled soap bubbles was demonstrated.

Virtual impactor

DOEpatents

Yeh, H.C.; Chen, B.T.; Cheng, Y.S.; Newton, G.J.

1988-08-30

A virtual impactor is described having improved efficiency and low wall losses in which a core of clean air is inserted into the aerosol flow while aerosol flow is maintained adjacent to the inner wall surfaces of the focusing portion of the impactor. The flow rate of the core and the length of the throat of the impactor's collection probe, as well as the dimensional relationships of other components of the impactor adjacent the separation region of the impactor, are selected to optimize separation efficiency. 4 figs.

Advanced Cathodes for Next Generation Electric Propulsion Technology

DTIC Science & Technology

2008-03-01

learning opportunity- of which it did. Finally, Dr. Glen Perram of the physics department at AFIT was so gracious to let us borrow his Langmuir Probe in...Applications Like Hall thrusters, ion thrusters also employ hollow cathodes.15,18,19,20,21 Harold Kaufman at NASA Glen Research Center (GRC... brittle nature, a problem common to CeB6 and LaB6. As a result, easier to machine polycrystalline inserts for LaB6 have been used for hollow cathodes in

Design, Fabrication, and Testing of a Composite Rack Prototype in Support of the Deep Space Habitat Program

NASA Technical Reports Server (NTRS)

Smith, Russ; Hagen, Richard

2015-01-01

In support of the Deep Space Habitat project a number of composite rack prototypes were developed, designed, fabricated and tested to various extents ( with the International Standard Payload Rack configuration, or crew quarters, as a baseline). This paper focuses specifically on a composite rack prototype with a direct tie in to Space Station hardware. The outlined prototype is an all composite construction, excluding metallic fasteners, washers, and their associated inserts. The rack utilizes braided carbon composite tubing for the frame with the sidewalls, backwall and flooring sections utilizing aircraft grade composite honeycomb sandwich panels. Novel additively manufactured thermoplastic joints and tube inserts were also developed in support of this effort. Joint and tube insert screening tests were conducted at a preliminary level. The screening tests allowed for modification, and enhancement, of the fabrication and design approaches, which will be outlined. The initial joint tests did not include mechanical fasteners. Adhesives were utilized at the joint to composite tube interfaces, along with mechanical fasteners during final fabrication (thus creating a stronger joint than the adhesive only variant). In general the prototype was focused on a potential in-space assembly approach, or kit-of-parts construction concept, which would not necessarily require the inclusion of an adhesive in the joint regions. However, given the tie in to legacy Station hardware (and potential flight loads with imbedded hardware mass loadings), the rack was built as stiff and strong as possible. Preliminary torque down tests were also conducted to determine the feasibility of mounting the composite honeycomb panels to the composite tubing sections via the additively manufactured tube inserts. Additional fastener torque down tests were also conducted with inserts (helicoils) imbedded within the joints. Lessons learned are also included and discussed.

Galileo Outreach Compilation

NASA Technical Reports Server (NTRS)

1998-01-01

This NASA JPL (Jet Propulsion Laboratory) video production is a compilation of the best short movies and computer simulation/animations of the Galileo spacecraft's journey to Jupiter. A limited number of actual shots are presented of Jupiter and its natural satellites. Most of the video is comprised of computer animations of the spacecraft's trajectory, encounters with the Galilean satellites Io, Europa and Ganymede, as well as their atmospheric and surface structures. Computer animations of plasma wave observations of Ganymede's magnetosphere, a surface gravity map of Io, the Galileo/Io flyby, the Galileo space probe orbit insertion around Jupiter, and actual shots of Jupiter's Great Red Spot are presented. Panoramic views of our Earth (from orbit) and moon (from orbit) as seen from Galileo as well as actual footage of the Space Shuttle/Galileo liftoff and Galileo's space probe separation are also included.

Transcriptional organization of the Escherichia coli pilus adhesin K99.

PubMed

Inoue, O J; Lee, J H; Isaacson, R E

1993-11-01

The production of the Escherichia coli pilus adhesin K99 requires the expression of eight unique proteins: FanA-H. The transcriptional organization of the K99 operon was investigated by Northern blot analysis. Four RNAs of 0.54, 1.4, 2.5 and 3.5 kb were detected. When a fanC probe was used all four RNAs were detected while the use of fanD, fanF and fanG probes detected two RNAs each. Using several deletion and TnphoA insertion mutants it was concluded that there were seven unique K99-specific transcripts, several of which were of the same approximate sizes (1.4 and 2.5 kb). It also was concluded that K99 was comprised of at least three complementation groups, two of which were regulated by catabolite repression.

An affordable and accurate conductivity probe for density measurements in stratified flows

NASA Astrophysics Data System (ADS)

Carminati, Marco; Luzzatto-Fegiz, Paolo

2015-11-01

In stratified flow experiments, conductivity (combined with temperature) is often used to measure density. The probes typically used can provide very fine spatial scales, but can be fragile, expensive to replace, and sensitive to environmental noise. A complementary instrument, comprising a low-cost conductivity probe, would prove valuable in a wide range of applications where resolving extremely small spatial scales is not needed. We propose using micro-USB cables as the actual conductivity sensors. By removing the metallic shield from a micro-B connector, 5 gold-plated microelectrodes are exposed and available for 4-wire measurements. These have a cell constant ~550m-1, an intrinsic thermal noise of at most 30pA/Hz1/2, as well as sub-millisecond time response, making them highly suitable for many stratified flow measurements. In addition, we present the design of a custom electronic board (Arduino-based and Matlab-controlled) for simultaneous acquisition from 4 sensors, with resolution (in conductivity, and resulting density) exceeding the performance of typical existing probes. We illustrate the use of our conductivity-measuring system through stratified flow experiments, and describe plans to release simple instructions to construct our complete system for around 200.

Characteristics of Ferromagnetic Flux Focusing Lens in the Development of Surface/Subsurface Flaw Detector

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Fulton, Jim; Nath, Shridhar; Namkung, Min; Simpson, John

1993-01-01

Electromagnetic NDE techniques have in the past steered away from the use of ferromagnetic materials. Although their high permeabilities lead to increased field levels, the properties of ferrous elements in the presence of alternating magnetic fields are difficult to determine. In addition, their use leads to losses which can be minimized through the use of low conductivity ferrites. In fact, the eddy current probes which do incorporate ferromagnetic materials have focused on these losses and the shielding which can be obtained by surrounding a probe with a high permeability, conducting material. Eddy current probes enclosed in conducting and magnetic shields have been used to prevent the generated fields from interacting with materials in the vicinity of the probe, such as when testing near material boundaries. A recent invention has used ferromagnetic shielding to magnetically separate individual concentric eddy current probes in order to eliminate cross-talk between the probes so that simultaneous detection of different types of flaws at different depths can be achieved. In contrast to the previous uses of ferromagnetic materials purely as magnetic shields, an electromagnetic flaw detector recently developed at NASA Langley Research Center takes advantage of the flux focusing properties of a ferromagnetic mild steel in order to produce a simple, effective device for the non-destructive evaluation of conducting materials. The Flux Focusing Eddy Current Probe has been shown to accurately measure material thickness and fatigue damage. The straight forward flaw response of the probe makes the device ideal for rapid inspection of large structures, and has lead to its incorporation in a computer controlled search routine to locate fatigue crack tips and monitor experimental fatigue crack growth experiments.

Fiberoptic probe and system for spectral measurements

DOEpatents

Dai, S.; Young, J.P.

1998-10-13

A fused fiberoptic probe, a system, method and embodiments thereof for conducting spectral measurements are disclosed. The fused fiberoptic probe comprises a probe tip having a specific geometrical configuration, an exciting optical fiber and at least one collection optical fiber fused within a housing, preferably silica. The specific geometrical configurations in which the probe tip can be shaped include a slanted probe tip with an angle greater than 0{degree}, an inverted cone-shaped probe tip, and a lens head. 12 figs.

Random insertion and gene disruption via transposon mutagenesis of Ureaplasma parvum using a mini-transposon plasmid

PubMed Central

Aboklaish, Ali F.; Dordet-Frisoni, Emilie; Citti, Christine; Toleman, Mark A; Glass, John I.; Spiller, O. Brad

2015-01-01

While transposon mutagenesis has been successfully used for Mycoplasma spp. to disrupt and determine non-essential genes, previous attempts with Ureaplasma spp. have been unsuccessful. Using a polyethylene glycol-transformation enhancing protocol, we were able to transform three separate serovars of Ureaplasma parvum with a Tn4001-based mini-transposon plasmid containing a gentamicin resistance selection marker. Despite the large degree of homology between Ureaplasma parvum and Ureaplasma urealyticum, all attempts to transform the latter in parallel failed, with the exception of a single clinical U. urealyticum isolate. PCR probing and sequencing were used to confirm transposon insertion into the bacterial genome and identify disrupted genes. Transformation of prototype serovar 3 consistently resulted in transfer only of sequence between the mini-transposon inverted repeats, but some strains showed additional sequence transfer. Transposon insertion occurred randomly in the genome resulting in unique disruption of genes UU047, UU390, UU440, UU450, UU520, UU526, UU582 for single clones from a panel of screened clones. An intergenic insertion between genes UU187 and UU188 was also characterised. Two phenotypic alterations were observed in the mutated strains: Disruption of a DEAD-box RNA helicase (UU582) altered growth kinetics, while the U. urealyticum strain lost resistance to serum attack coincident with disruption of gene UUR10_137 and loss of expression of a 41 kDa protein. Transposon mutagenesis was used successfully to insert single copies of a mini-transposon into the genome and disrupt genes leading to phenotypic changes in Ureaplasma parvum strains. This method can now be used to deliver exogenous genes for expression and determine essential genes for Ureaplasma parvum replication in culture and experimental models. PMID:25444567

Random insertion and gene disruption via transposon mutagenesis of Ureaplasma parvum using a mini-transposon plasmid.

PubMed

Aboklaish, Ali F; Dordet-Frisoni, Emilie; Citti, Christine; Toleman, Mark A; Glass, John I; Spiller, O Brad

2014-11-01

While transposon mutagenesis has been successfully used for Mycoplasma spp. to disrupt and determine non-essential genes, previous attempts with Ureaplasma spp. have been unsuccessful. Using a polyethylene glycol-transformation enhancing protocol, we were able to transform three separate serovars of Ureaplasma parvum with a Tn4001-based mini-transposon plasmid containing a gentamicin resistance selection marker. Despite the large degree of homology between Ureaplasma parvum and Ureaplasma urealyticum, all attempts to transform the latter in parallel failed, with the exception of a single clinical U. urealyticum isolate. PCR probing and sequencing were used to confirm transposon insertion into the bacterial genome and identify disrupted genes. Transformation of prototype serovar 3 consistently resulted in transfer only of sequence between the mini-transposon inverted repeats, but some strains showed additional sequence transfer. Transposon insertion occurred randomly in the genome resulting in unique disruption of genes UU047, UU390, UU440, UU450, UU520, UU526, UU582 for single clones from a panel of screened clones. An intergenic insertion between genes UU187 and UU188 was also characterised. Two phenotypic alterations were observed in the mutated strains: Disruption of a DEAD-box RNA helicase (UU582) altered growth kinetics, while the U. urealyticum strain lost resistance to serum attack coincident with disruption of gene UUR10_137 and loss of expression of a 41 kDa protein. Transposon mutagenesis was used successfully to insert single copies of a mini-transposon into the genome and disrupt genes leading to phenotypic changes in Ureaplasma parvum strains. This method can now be used to deliver exogenous genes for expression and determine essential genes for Ureaplasma parvum replication in culture and experimental models. Copyright © 2014 Elsevier GmbH. All rights reserved.

A comparison of needle tip localization accuracy using 2D and 3D trans-rectal ultrasound for high-dose-rate prostate cancer brachytherapy treatment planning

NASA Astrophysics Data System (ADS)

Hrinivich, W. Thomas; Hoover, Douglas A.; Surry, Kathleen; Edirisinghe, Chandima; Montreuil, Jacques; D'Souza, David; Fenster, Aaron; Wong, Eugene

2016-03-01

Background: High-dose-rate brachytherapy (HDR-BT) is a prostate cancer treatment option involving the insertion of hollow needles into the gland through the perineum to deliver a radioactive source. Conventional needle imaging involves indexing a trans-rectal ultrasound (TRUS) probe in the superior/inferior (S/I) direction, using the axial transducer to produce an image set for organ segmentation. These images have limited resolution in the needle insertion direction (S/I), so the sagittal transducer is used to identify needle tips, requiring a manual registration with the axial view. This registration introduces a source of uncertainty in the final segmentations and subsequent treatment plan. Our lab has developed a device enabling 3D-TRUS guided insertions with high S/I spatial resolution, eliminating the need to align axial and sagittal views. Purpose: To compare HDR-BT needle tip localization accuracy between 2D and 3D-TRUS. Methods: 5 prostate cancer patients underwent conventional 2D TRUS guided HDR-BT, during which 3D images were also acquired for post-operative registration and segmentation. Needle end-length measurements were taken, providing a gold standard for insertion depths. Results: 73 needles were analyzed from all 5 patients. Needle tip position differences between imaging techniques was found to be largest in the S/I direction with mean+/-SD of -2.5+/-4.0 mm. End-length measurements indicated that 3D TRUS provided statistically significantly lower mean+/-SD insertion depth error of -0.2+/-3.4 mm versus 2.3+/-3.7 mm with 2D guidance (p < .001). Conclusions: 3D TRUS may provide more accurate HDR-BT needle localization than conventional 2D TRUS guidance for the majority of HDR-BT needles.

Integrated circuit amplifiers for multi-electrode intracortical recording.

PubMed

Jochum, Thomas; Denison, Timothy; Wolf, Patrick

2009-02-01

Significant progress has been made in systems that interpret the electrical signals of the brain in order to control an actuator. One version of these systems senses neuronal extracellular action potentials with an array of up to 100 miniature probes inserted into the cortex. The impedance of each probe is high, so environmental electrical noise is readily coupled to the neuronal signal. To minimize this noise, an amplifier is placed close to each probe. Thus, the need has arisen for many amplifiers to be placed near the cortex. Commercially available integrated circuits do not satisfy the area, power and noise requirements of this application, so researchers have designed custom integrated-circuit amplifiers. This paper presents a comprehensive survey of the neural amplifiers described in publications prior to 2008. Methods to achieve high input impedance, low noise and a large time-constant high-pass filter are reviewed. A tutorial on the biological, electrochemical, mechanical and electromagnetic phenomena that influence amplifier design is provided. Areas for additional research, including sub-nanoampere electrolysis and chronic cortical heating, are discussed. Unresolved design concerns, including teraohm circuitry, electrical overstress and component failure, are identified.

Transurethral illumination probe design for deep photoacoustic imaging of prostate

NASA Astrophysics Data System (ADS)

Ai, Min; Salcudean, Tim; Rohling, Robert; Abolmaesumi, Purang; Tang, Shuo

2018-02-01

Photoacoustic (PA) imaging with internal light illumination through optical fiber could enable imaging of internal organs at deep penetration. We have developed a transurethral probe with a multimode fiber inserted in a rigid cystoscope sheath for illuminating the prostate. At the distal end, the fiber tip is processed to diffuse light circumferentially over 2 cm length. A parabolic cylinder mirror then reflects the light to form a rectangular-shaped parallel beam which has at least 1 cm2 at the probe surface. The relatively large rectangular beam size can reduce the laser fluence rate on the urethral wall and thus reduce the potential of tissue damage. A 3 cm optical penetration in chicken tissue is achieved at a fluence rate around 7 mJ/cm2 . For further validation, a prostate phantom was built with similar optical properties of the human prostate. A 1.5 cm penetration depth is achieved in the prostate mimicking phantom at 10 mJ/cm2 fluence rate. PA imaging of prostate can potentially be carried out in the future by combining a transrectal ultrasound transducer and the transurethral illumination.

Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts.

PubMed

Katagiri, Takashi; Shibayama, Kyosuke; Iida, Takeru; Matsuura, Yuji

2018-03-27

A real-time gas monitoring system based on optical absorption spectroscopy is proposed for localized carbon dioxide (CO₂) measurement in respiratory tracts. In this system, a small gas cell is attached to the end of a hollow optical fiber that delivers mid-infrared light with small transmission loss. The diameters of the fiber and the gas cell are smaller than 1.2 mm so that the probe can be inserted into a working channel of common bronchoscopes. The dimensions of the gas cell are designed based on absorption spectra of CO₂ standard gases in the 4.2 μm wavelength region, which are measured using a Fourier-transform infrared spectrometer. A miniature gas cell that is comprised of a stainless-steel tube with slots for gas inlet and a micro-mirror is fabricated. A compact probing system with a quantum cascade laser (QCL) light source is built using a gas cell with a hollow optical fiber for monitoring CO₂ concentration. Experimental results using human breaths show the feasibility of the system for in-situ measurement of localized CO₂ concentration in human airways.

Target-catalyzed hairpin assembly and metal-organic frameworks mediated nonenzymatic co-reaction for multiple signal amplification detection of miR-122 in human serum.

PubMed

Li, Yuliang; Yu, Chao; Yang, Bo; Liu, Zhirui; Xia, Peiyuan; Wang, Qian

2018-04-15

Herein, a new type of multifunctional iron based metal-organic frameworks (PdNPs@Fe-MOFs) has been synthesized by assembly palladium nanoparticles on the surface of Fe-MIL-88NH 2 MOFs microcrystals, and first applied in electrochemical biosensor for ultrasensitive detection of microRNA-122 (miR-122, a biomarker of drug-induced liver injury). The nanohybrids have not only been utilized as ideal nanocarriers for immobilization of signal probes, but also used as redox probes and electrocatalysts. In this biosensor, two hairpin probes were designed as capture probes and signal probes, respectively. The nanohybrids conjugated with streptavidin and biotinylated signal probes were used as the tracer labels, target miR-122 was sandwiched between the tracer labels and thiol-terminated capture probes inserted in MCH monolayer on the gold nanoparticles-functionalized nitrogen-doped graphene sheets (AuNPs@N-G) modified electrode. Based on target-catalyzed hairpin assembly, target miR-122 could trigger the hybridization of capture probes and signal probes to further be released to initiate the next reaction process resulted in numerous tracer indicators anchored onto the sensing interfaces. Thus, the detection signal could be dramatically enhanced towards the electrocatalytic oxidation of 3,3',5,5'-tetramethylbenzidine in the presence of H 2 O 2 owing to the intrinsic and intriguing peroxidase-like activity of the nanohybrids. With the assist of target-catalyzed hairpin assembly and PdNPs@Fe-MOFs mimetic co-reaction for signal amplification, a wide detection range from 0.01fM to 10pM was achieved with a low detection limit of 0.003fM (S/N =3). Furthermore, the proposed biosensor exhibited excellent specificity and recovery in spiked serum samples, and was successfully used for detecting miR-122 in real biological samples, which provided a rapid and efficient method for detecting drug-induced liver injury at an early stage. Copyright © 2017. Published by Elsevier B.V.

A High-Resolution Cluster of Oceanographic Instruments for Boundary Layer Measurements under Ice.

DTIC Science & Technology

1985-11-01

arrangement for use with laser velocimetry. The EO components are mounted on an aluminum chassis, which is in turn placed in an underwater housing made...temperature/conductivity probe pair used * on the HRC cluster. It consists of a thermistor probe (FASTIP, Model FP07, Thermometrics , Inc.) and a dual...component. The orientation of all three DLT)V pairs is shown in Figure 1. 3.2 Temperature and Conductivity Probes The FASTIP thermistor by Thermometrics

Radioguided localisation of impalpable breast lesions using 99m-Technetium macroaggregated albumin: Lessons learnt during introduction of a new technique to guide preoperative localisation

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

Landman, Joanne; Kulawansa, Sagarika; McCarthy, Michael

2015-03-15

Preoperative wire-guided localisation (WGL) of impalpable breast lesions is widely used but can be technically difficult. Risks include wire migration, inaccurate placement, and inadequate surgical margins. Research shows that radioguided occult lesion localisation (ROLL) is quicker, easier, and can improve surgical and cosmetic outcomes. An audited introduction of ROLL was conducted to validate the technique as a feasible alternative to WGL. Fifty patients with single impalpable lesions and biopsy proven malignancy or indeterminate histology underwent WGL followed by intralesional radiopharmaceutical injection of 99m-Technetium macroaggregated albumin. Postprocedural mammography was performed to demonstrate wire position, and scintigraphy to evaluate radiopharmaceutical migration. Lymphoscintigraphymore » and intraoperative sentinel node biopsy were performed if indicated, followed by lesion localisation and excision using a gamma probe. Specimen imaging was performed, with immediate reexcision for visibly inadequate margins. Accurate localisation was achieved in 86% of patients with ROLL compared to 72% with WGL. All lesions were successfully removed, with clear margins in 71.8% of malignant lesions. Reexcision and intraoperative sentinel node localisation rates were equivalent to preaudit figures for WGL. ROLL was easy to perform and problems were infrequent. Inaccurate radiopharmaceutical placement necessitating WGL occurred in four patients. Minor radiopharmaceutical migration was common, but precluded using ROLL in only two cases. ROLL is effective, simple, inexpensive, and easily learnt; however, preoperative confirmation of correct radiopharmaceutical placement using mammography and the gamma probe is important to help ensure successful lesion removal. Insertion of a backup hookwire is recommended during the initial introduction of ROLL.« less

Insertion of linear 8.4 μm diameter 16 channel carbon fiber electrode arrays for single unit recordings

PubMed Central

Patel, Paras R.; Na, Kyounghwan; Zhang, Huanan; Kozai, Takashi D. Y.; Kotov, Nicholas A.; Yoon, Euisik; Chestek, Cynthia A.

2016-01-01

Objective Single carbon fiber electrodes (d=8.4 μm) insulated with parylene-c and functionalized with PEDOT:pTS have been shown to record single unit activity but manual implantation of these devices with forceps can be difficult. Without an improvement in the insertion method any increase in the channel count by fabricating carbon fiber arrays would be impractical. In this study, we utilize a water soluble coating and structural backbones that allow us to create, implant, and record from fully functionalized arrays of carbon fibers with ~150 μm pitch. Approach Two approaches were tested for the insertion of carbon fiber arrays. The first method used a PEG coating that temporarily stiffened the fibers while leaving a small portion at the tip exposed. The small exposed portion (500 μm – 1 mm) readily penetrated the brain allowing for an insertion that did not require the handling of each fiber by forceps. The second method involved the fabrication of silicon support structures with individual shanks spaced 150 μm apart. Each shank consisted of a small groove that held an individual carbon fiber. Main results Our results showed that the PEG coating allowed for the chronic implantation of carbon fiber arrays in 5 rats with unit activity detected at 31 days post-implant. The silicon support structures recorded single unit activity in 3 acute rat surgeries. In one of those surgeries a stacked device with 3 layers of silicon support structures and carbon fibers was built and shown to readily insert into the brain with unit activity on select sites. Significance From these studies we have found that carbon fibers spaced at ~150 μm readily insert into the brain. This greatly increases the recording density of chronic neural probes and paves the way for even higher density devices that have a minimal scarring response. PMID:26035638

All-Atom Molecular Dynamics-Based Analysis of Membrane-Stabilizing Copolymer Interactions with Lipid Bilayers Probed under Constant Surface Tensions.

PubMed

Houang, Evelyne M; Bates, Frank S; Sham, Yuk Y; Metzger, Joseph M

2017-11-30

An all-atom phospholipid bilayer and triblock copolymer model was developed for molecular dynamics (MD) studies. These were performed to investigate the mechanism of interaction between membrane-stabilizing triblock copolymer P188 and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid bilayers under applied lateral surface tension (γ) to model membrane mechanical stress. Results showed that P188 insertion is driven by the hydrophobic poly(propylene oxide) (PPO) core and dependent on bilayer area per lipid. Moreover, insertion of P188 increased the bilayer's resistance to mechanical rupture, as observed by a significant increase in the absolute lateral pressure required to disrupt the bilayer. To further investigate the specific chemical features of P188 underlying membrane stabilizer function, a series of MD simulations with triblock copolymers of the same class as P188 but of varying chemical composition and sizes were performed. Results showed that triblock copolymer insertion into the lipid bilayer is dependent on overall copolymer hydrophobicity, with higher copolymer hydrophobicity requiring a reduced bilayer area per lipid ratio for insertion. Further analysis revealed that the effect of copolymer insertion on membrane mechanical integrity was also dependent on hydrophobicity. Here, P188 insertion significantly increased the absolute apparent lateral pressure required to rupture the POPC bilayer, thereby protecting the membrane against mechanical stress. In marked contrast, highly hydrophobic copolymers decreased the lateral pressure necessary for membrane rupture and thus rendering the membrane significantly more susceptible to mechanical stress. These new in silico findings align with recent experimental findings using synthetic lipid bilayers and in muscle cells in vitro and mouse models in vivo. Collectively, these data underscore the importance of PEO-PPO-PEO copolymer chemical composition in copolymer-based muscle membrane stabilization in vitro and in vivo. All-atom modeling with MD simulations holds promise for investigating novel copolymers with enhanced membrane interacting properties.

Comparative Assessment of Cutting Inserts and Optimization during Hard Turning: Taguchi-Based Grey Relational Analysis

NASA Astrophysics Data System (ADS)

Venkata Subbaiah, K.; Raju, Ch.; Suresh, Ch.

2017-08-01

The present study aims to compare the conventional cutting inserts with wiper cutting inserts during the hard turning of AISI 4340 steel at different workpiece hardness. Type of insert, hardness, cutting speed, feed, and depth of cut are taken as process parameters. Taguchi’s L18 orthogonal array was used to conduct the experimental tests. Parametric analysis carried in order to know the influence of each process parameter on the three important Surface Roughness Characteristics (Ra, Rz, and Rt) and Material Removal Rate. Taguchi based Grey Relational Analysis (GRA) used to optimize the process parameters for individual response and multi-response outputs. Additionally, the analysis of variance (ANOVA) is also applied to identify the most significant factor.

Multi-function diamond film fiberoptic probe and measuring system employing same

DOEpatents

Young, Jack P.

1998-01-01

A fused fiberoptic probe having a protective cover, a fiberoptic probe system, and embodiments thereof for conducting electromagnetic spectral measurements are disclosed. The fused fiberoptic probe comprises a probe tip having a specific geometrical configuration, an exciting optical fiber and at least one collection optical fiber fused within a housing, preferrably silica, with a protective cover disposed over at least a portion of the probe tip. The specific geometrical configurations in which the probe tip can be shaped include a slanted probe tip with an angle greater than 0.degree., an inverted cone-shaped probe tip, and a lens head.

Lidocaine-Prilocaine Cream as Analgesia for IUD Insertion: A Prospective, Randomized, Controlled, Triple Blinded Study

PubMed Central

Tavakolian, Samira; Doulabi, Mahbobeh Ahmadi; Baghban, Alireza Akbarzade; Mortazavi, Alireza; Ghorbani, Maryam

2015-01-01

Introduction: Copper IUD is a long term and reversible contraception which equals tubal ligation in terms of sterilization. One of the barriers to using this contraception method is the fear and the pain associated with its insertion. Eutectic mixture of local anesthetics (EMLA) 5% is a local anesthetic that contains 25 mg lidocaine and 25 mg of prilocaine per gram. Application of topical analgesic cream to the cervix for laser surgery, hysteroscopy and hysterosalpingography is known Aims: this study aimed to determine the effect of EMLA on IUD insertion pain. Methods: This triple blind clinical trial was conducted on 92 women in a clinic in Hamedan in 2012. After applying the cream on the cervix, pain in three steps, after using Tenaculum, after inserting hystrometr and after inserting IUD and removing IUD insertion tube were assessed with visual analog scale and were compared in EMLA group and placebo group Statistical analysis used to determine and compare the pain of independent t tests, Mann-Whitney U test and repeated measures analysis of variance and chi-square tests to determine the homogeneity of variables and Fisher’s exact test was used Results: Insertion hystrometr was determined as the most painful IUD insertion. The mean pain at step 2 (inserting hystrometr) was (3/11±2/53) in EMLA group, (5/23±2/31) in placebo group. EMLA cream significantly reduced the pain after using tenaculum (P<0/001), pain inserting Hystrometr (P< 0/001) and pain at IUD insertion and removing insertion tube (P< 0/001) Conclusions: Topical Application of EMLA 5% cream as a topical anesthetic on the cervix before insertion IUD reduced the pain during this procedure. PMID:25946948

Mode control using two electrodes on HBT-EP

NASA Astrophysics Data System (ADS)

Stewart, I. G.; Brooks, J. W.; Levesque, J. P.; Mauel, M. E.; Navratil, G. A.

2017-10-01

Understanding the effects of plasma rotation on magnetohydrodynamic (MHD) modes and tokamak plasma stability is important for performance enhancement of current magnetic confinement experiments and to future fusion devices such as ITER. In order to control plasma rotation, two molybdenum electrodes have been installed on HBT-EP toroidally separated by 144 degrees. This allows independent biasing of the two probes both spatially and temporally. When the bias probes are inserted into the edge of the plasma and a voltage is applied, the probes drive radial currents and produce plasma flow from the torque induced by the currents. If the bias probe voltage is sufficiently positive, the MHD mode rotation transitions into a state with a rapid mode rotation frequency (in excess of 25 kHz) in the direction opposite to mode rotation without bias. The transition into this reversed rotation state occurs when the torque exceeds a threshold, which can depend upon the phase of an applied n = 1 error field. We present recent studies of the two-electrode system on mode rotation, mode stability, and the toroidal symmetry of the radial current through the scrape-off-layer (SOL) during MHD activity and applied magnetic perturbations. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Clinical and genetic characteristics of chinese patients with Birt-Hogg-Dubé syndrome.

PubMed

Liu, Yaping; Xu, Zhiyan; Feng, Ruie; Zhan, Yongzhong; Wang, Jun; Li, Guozhen; Li, Xue; Zhang, Weihong; Hu, Xiaowen; Tian, Xinlun; Xu, Kai-Feng; Zhang, Xue

2017-05-30

Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant disorder, the main manifestations of which are fibrofolliculomas, renal tumors, pulmonary cysts and recurrent pneumothorax. The known causative gene for BHD syndrome is the folliculin (FLCN) gene on chromosome 17p11.2. Studies of the FLCN mutation for BHD syndrome are less prevalent in Chinese populations than in Caucasian populations. Our study aims to investigate the genotype spectrum in a group of Chinese patients with BHD. We enrolled 51 patients with symptoms highly suggestive of BHD from January 2014 to February 2017. The FLCN gene was examined using PCR and Sanger sequencing in every patient, for those whose Sanger sequencing showed negative mutation results, multiplex ligation-dependent probe amplification (MLPA) testing was conducted to detect any losses of large segments. Among the 51 patients, 27 had FLCN germline mutations. In total, 20 mutations were identified: 14 were novel mutations, including 3 splice acceptor site mutations, 2 different deletions, 6 nonsense mutations, 1 missense mutation, 1 small insertion, and 1 deletion of the whole exon 8. We found a similar genotype spectrum but different mutant loci in Chinese patients with BHD compared with European and American patients, thus providing stronger evidence for the clinical molecular diagnosis of BHD in China. It suggests that mutation analysis of the FLCN gene should be systematically conducted in patients with cystic lung diseases.

High pressure optical combustion probe

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

Woodruff, S.D.; Richards, G.A.

1995-06-01

The Department of Energy`s Morgantown Energy Technology Center has developed a combustion probe for monitoring flame presence and heat release. The technology involved is a compact optical detector of the OH radical`s UV fluorescence. The OH Monitor/Probe is designed to determine the flame presence and provide a qualitative signal proportional to the flame intensity. The probe can be adjusted to monitor a specific volume in the combustion zone to track spatial fluctuations in the flame. The probe is capable of nanosecond time response and is usually slowed electronically to fit the flame characteristics. The probe is a sapphire rod inmore » a stainless steel tube which may be inserted into the combustion chamber and pointed at the flame zone. The end of the sapphire rod is retracted into the SS tube to define a narrow optical collection cone. The collection cone may be adjusted to fit the experiment. The fluorescence signal is collected by the sapphire rod and transmitted through a UV transmitting, fused silica, fiber optic to the detector assembly. The detector is a side window photomultiplier (PMT) with a 310 run line filter. A Hamamatsu photomultiplier base combined with a integral high voltage power supply permits this to be a low voltage device. Electronic connections include: a power lead from a modular DC power supply for 15 VDC; a control lead for 0-1 volts to control the high voltage level (and therefore gain); and a lead out for the actual signal. All low voltage connections make this a safe and easy to use device while still delivering the sensitivity required.« less

Multiwaveguide implantable probe for light delivery to sets of distributed brain targets.

PubMed

Zorzos, Anthony N; Boyden, Edward S; Fonstad, Clifton G

2010-12-15

Optical fibers are commonly inserted into living tissues such as the brain in order to deliver light to deep targets for neuroscientific and neuroengineering applications such as optogenetics, in which light is used to activate or silence neurons expressing specific photosensitive proteins. However, an optical fiber is limited to delivering light to a single target within the three-dimensional structure of the brain. We here demonstrate a multiwaveguide probe capable of independently delivering light to multiple targets along the probe axis, thus enabling versatile optical control of sets of distributed brain targets. The 1.45-cm-long probe is microfabricated in the form of a 360-μm-wide array of 12 parallel silicon oxynitride (SiON) multimode waveguides clad with SiO(2) and coated with aluminum; probes of custom dimensions are easily created as well. The waveguide array accepts light from a set of sources at the input end and guides the light down each waveguide to an aluminum corner mirror that efficiently deflects light away from the probe axis. Light losses at each stage are small (input coupling loss, 0.4 ± 0.3 dB; bend loss, negligible; propagation loss, 3.1 ± 1 dB/cm using the outscattering method and 3.2 ± 0.4 dB/cm using the cutback method; corner mirror loss, 1.5 ± 0.4 dB); a waveguide coupled, for example, to a 5 mW source will deliver over 1.5 mW to a target at a depth of 1 cm.

Increasing use of less-invasive hemodynamic monitoring in 3 specialty surgical intensive care units: a 5-year experience at a tertiary medical center.

PubMed

Kirton, Orlando C; Calabrese, Rebecca C; Staff, Ilene

2015-01-01

Less-invasive hemodynamic monitoring (eg, esophageal doppler monitoring [EDM] and arterial pressure contour analysis, FloTrac) is increasingly used as an alternative to pulmonary artery catheters (PACs) in critically ill intensive care unit (ICU). The decrease in use of PACs is not associated with increased mortality. Five-year retrospective review of 1894 hemodynamically monitored patients admitted to 3 surgical ICUs in a university-affiliate, tertiary care urban hospital. Data included the number of admissions, diagnosis-related group discharge case mix, length of stay, insertion of monitoring devices (PAC, EDM, and FloTrac probes), administered intravenous vasoactive agents (β-predominant agonists--dobutamine, epinephrine, and dopamine; vasopressors--norepinephrine and phenylephrine), and mortality. Data from hospital administrative databases were compiled to create patient characteristic and monitoring variables across a 5-year time period, 2005 to 2009 inclusive. Chi-square for independent proportions, 1-way analysis of variance, and Kruskal-Wallis tests were used; tests for trend were conducted. An α level of .05 was considered significant. Statistical Package for the Social Sciences v14 was used for all statistical testing. There was a significant change in the type of hemodynamic monitors inserted in 2 of the 3 surgical ICUs (in the general surgery and neurointensive care but not in the cardiac ICU) from PACs to less-invasive devices (FloTrac or EDM) during the 5-year study period (P < .001). There was no change in mortality rate over the time period (P = .492). There was an overall increase in the proportion of monitored patients who received intravenous vasoactive agents (P < .001) with a progressive shift from β-agonists to vasopressors (P < .002). Multivariate analyses indicated that age, case mix, and use of vasoactive agents were all independent predictors of inhospital mortality (P = .001) but that type of monitoring was not (P = .638). In a 5-year period, the decreased insertions of PACs were replaced by increased utilization of less-invasive hemodynamic monitoring devices. This change in practice did not adversely impact mortality. © The Author(s) 2013.

Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement

DOEpatents

Kikta, Thomas J.; Mitchell, Ronald D.

1992-01-01

A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet.

Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement

DOEpatents

Kikta, T.J.; Mitchell, R.D.

1992-11-24

A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet. 4 figs.

Molecular Simulation of Gas Solubility in Nitrile Butadiene Rubber.

PubMed

Khawaja, M; Sutton, A P; Mostofi, A A

2017-01-12

Molecular simulation is used to compute the solubility of small gases in nitrile butadiene rubber (NBR) with a Widom particle-insertion technique biased by local free volume. The convergence of the method is examined as a function of the number of snapshots upon which the insertions are performed and the number of insertions per snapshot and is compared to the convergence of the unbiased Widom insertion technique. The effect of varying the definition of local free volume is also investigated. The acrylonitrile content of the polymer is altered to examine its influence on the solubility of helium, CO 2 , and H 2 O, and the solubilities of polar gases are found to be enhanced relative to those of nonpolar gases, in qualitative agreement with experiment. To probe this phenomenon further, the solubilities are decomposed into contributions from the neighborhoods of different atoms, using a Voronoi cell construction, and a strong bias is found for CO 2 and H 2 O in particular to be situated near nitrogen sites in the elastomer. Temperature is shown to suppress the solubility of CO 2 and H 2 O but to increase that of helium. Increasing pressure is found to suppress the solubility of all gases but at different rates, according to a balance between their molecular sizes and electrostatic interactions with the polymer. These results are relevant to the use of NBR seals at elevated temperatures and pressures, such as in oil and gas wells.

Scanning Electrochemical Microscopy as a Novel Proximity Sensor for Atraumatic Cochlear Implant Insertion

PubMed Central

Velmurugan, J.; Mirkin, M. V.; Svirsky, M. A.; Lalwani, A. K.; Llinas, R. R.

2014-01-01

A growing number of minimally invasive surgical and diagnostic procedures require the insertion of an optical, mechanical, or electronic device in narrow spaces inside a human body. In such procedures, precise motion control is essential to avoid damage to the patient’s tissues and/or the device itself. A typical example is the insertion of a cochlear implant which should ideally be done with minimum physical contact between the moving device and the cochlear canal walls or the basilar membrane. Because optical monitoring is not possible, alternative techniques for sub millimeter-scale distance control can be very useful for such procedures. The first requirement for distance control is distance sensing. We developed a novel approach to distance sensing based on the principles of scanning electrochemical microscopy (SECM). The SECM signal, i.e., the diffusion current to a microelectrode, is very sensitive to the distance between the probe surface and any electrically insulating object present in its proximity. With several amperometric microprobes fabricated on the surface of an insertable device, one can monitor the distances between different parts of the moving implant and the surrounding tissues. Unlike typical SECM experiments, in which a disk-shaped tip approaches a relatively smooth sample, complex geometries of the mobile device and its surroundings make distance sensing challenging. Additional issues include the possibility of electrode surface contamination in biological fluids and the requirement for a biologically compatible redox mediator. PMID:24845292

Generation of 24 T at 4.2 K using a layer-wound GdBCO insert coil with Nb3Sn and Nb-Ti external magnetic field coils

NASA Astrophysics Data System (ADS)

Matsumoto, S.; Kiyoshi, T.; Otsuka, A.; Hamada, M.; Maeda, H.; Yanagisawa, Y.; Nakagome, H.; Suematsu, H.

2012-02-01

High-temperature superconducting (HTS) magnets are believed to be a practical option in the development of high field nuclear magnetic resonance (NMR) systems. The development of a 600 MHz NMR system that uses an HTS magnet and a probe with an HTS radio frequency coil is underway. The HTS NMR magnet is expected to reduce the volume occupied by the magnet and to encourage users to install higher field NMR systems. The tolerance to high tensile stress is expected for HTS conductors in order to reduce the magnet in volume. A layer-wound Gd-Ba-Cu-O (GdBCO) insert coil was fabricated in order to investigate its properties under a high electromagnetic force in a high magnetic field. The GdBCO insert coil was successfully operated at a current of up to 321 A and an electromagnetic force BJR of 408 MPa in an external magnetic field generated by Nb3Sn and Nb-Ti low-temperature superconducting coils. The GdBCO insert coil also managed to generate a magnetic field of 6.8 T at the center of the coil in an external magnetic field of 17.2 T. The superconducting magnet consisting of GdBCO, Nb3Sn and Nb-Ti coils successfully generated a magnetic field of 24.0 T at 4.2 K, which represents a new record for a superconducting magnet.

Study of polarization properties of fiber-optics probes with use of a binary phase plate.

PubMed

Alferov, S V; Khonina, S N; Karpeev, S V

2014-04-01

We conduct a theoretical and experimental study of the distribution of the electric field components in the sharp focal domain when rotating a zone plate with a π-phase jump placed in the focused beam. Comparing the theoretical and experimental results for several kinds of near-field probes, an analysis of the polarization sensitivity of different types of metal-coated aperture probes is conducted. It is demonstrated that with increasing diameter of the non-metal-coated tip part there occurs an essential redistribution of sensitivity in favor of the transverse electric field components and an increase of the probe's energy throughput.

Improved data reduction algorithm for the needle probe method applied to in-situ thermal conductivity measurements of lunar and planetary regoliths

NASA Astrophysics Data System (ADS)

Nagihara, Seiichi; Hedlund, Magnus; Zacny, Kris; Taylor, Patrick T.

2014-03-01

The needle probe method (also known as the ‘hot wire’ or ‘line heat source’ method) is widely used for in-situ thermal conductivity measurements on terrestrial soils and marine sediments. Variants of this method have also been used (or planned) for measuring regolith on the surfaces of extra-terrestrial bodies (e.g., the Moon, Mars, and comets). In the near-vacuum condition on the lunar and planetary surfaces, the measurement method used on the earth cannot be simply duplicated, because thermal conductivity of the regolith can be ~2 orders of magnitude lower. In addition, the planetary probes have much greater diameters, due to engineering requirements associated with the robotic deployment on extra-terrestrial bodies. All of these factors contribute to the planetary probes requiring a much longer time of measurement, several tens of (if not over a hundred) hours, while a conventional terrestrial needle probe needs only 1 to 2 min. The long measurement time complicates the surface operation logistics of the lander. It also negatively affects accuracy of the thermal conductivity measurement, because the cumulative heat loss along the probe is no longer negligible. The present study improves the data reduction algorithm of the needle probe method by shortening the measurement time on planetary surfaces by an order of magnitude. The main difference between the new scheme and the conventional one is that the former uses the exact mathematical solution to the thermal model on which the needle probe measurement theory is based, while the latter uses an approximate solution that is valid only for large times. The present study demonstrates the benefit of the new data reduction technique by applying it to data from a series of needle probe experiments carried out in a vacuum chamber on a lunar regolith simulant, JSC-1A. The use of the exact solution has some disadvantage, however, in requiring three additional parameters, but two of them (the diameter and the volumetric heat capacity of the probe) can be measured and the other (the volumetric heat capacity of the regolith/stimulant) may be estimated from the surface geologic observation and temperature measurements. Therefore, overall, the new data reduction scheme would make in-situ thermal conductivity measurement more practical on planetary missions.

Improved Data Reduction Algorithm for the Needle Probe Method Applied to In-Situ Thermal Conductivity Measurements of Lunar and Planetary Regoliths

NASA Technical Reports Server (NTRS)

Nagihara, S.; Hedlund, M.; Zacny, K.; Taylor, P. T.

2013-01-01

The needle probe method (also known as the' hot wire' or 'line heat source' method) is widely used for in-situ thermal conductivity measurements on soils and marine sediments on the earth. Variants of this method have also been used (or planned) for measuring regolith on the surfaces of extra-terrestrial bodies (e.g., the Moon, Mars, and comets). In the near-vacuum condition on the lunar and planetary surfaces, the measurement method used on the earth cannot be simply duplicated, because thermal conductivity of the regolith can be approximately 2 orders of magnitude lower. In addition, the planetary probes have much greater diameters, due to engineering requirements associated with the robotic deployment on extra-terrestrial bodies. All of these factors contribute to the planetary probes requiring much longer time of measurement, several tens of (if not over a hundred) hours, while a conventional terrestrial needle probe needs only 1 to 2 minutes. The long measurement time complicates the surface operation logistics of the lander. It also negatively affects accuracy of the thermal conductivity measurement, because the cumulative heat loss along the probe is no longer negligible. The present study improves the data reduction algorithm of the needle probe method by shortening the measurement time on planetary surfaces by an order of magnitude. The main difference between the new scheme and the conventional one is that the former uses the exact mathematical solution to the thermal model on which the needle probe measurement theory is based, while the latter uses an approximate solution that is valid only for large times. The present study demonstrates the benefit of the new data reduction technique by applying it to data from a series of needle probe experiments carried out in a vacuum chamber on JSC-1A lunar regolith stimulant. The use of the exact solution has some disadvantage, however, in requiring three additional parameters, but two of them (the diameter and the volumetric heat capacity of the probe) can be measured and the other (the volumetric heat capacity of the regolith/stimulant) may be estimated from the surface geologic observation and temperature measurements. Therefore, overall, the new data reduction scheme would make in-situ thermal conductivity measurement more practical on planetary missions.

Cassini-Huygens enters orbit around the ringed planet

NASA Astrophysics Data System (ADS)

2004-07-01

“This shows international space co-operation at its best,” said ESA’s Director of Science, Prof. David Southwood, after confirmation of the orbit insertion. “Few deep-space planetary missions have carried the hopes of such a large community of scientists and space enthusiasts around the world. Congratulations to the teams in the US and Europe who made this possible and to all participants in the programme, who have a lot to do over the years ahead.” The Saturn Orbit Insertion was the last and most critical manoeuvre performed by the spacecraft to achieve its operational orbit. If it had failed, the spacecraft would have just flown past Saturn and got lost in the outer Solar System. Cassini-Huygens was launched from Cape Canaveral, Florida, on 15 October 1997, atop a Titan 4B/Centaur, the most powerful expendable launch vehicle in the US fleet at the time. To reach Saturn it had to perform a series of gravity assist manoeuvres around Venus (April 1998 and June 1999), Earth (August 1999) and Jupiter (December 2000). Last night, Cassini-Huygens approached Saturn from below the plane of its rings. Using its high-gain antenna dish as a shield to protect its fragile body from dust impacts, it first crossed the ring plane at 02:03 UT, some 158 500 kilometres from the centre of Saturn, in the gap that separates the F-ring from the G-ring. About 25 minutes later, at 02:36 UT, the probe fired one of its twin main engines for a 96-minute burn to enter orbit. The signal confirming this ignition took 84 minutes to reach Earth, some 1500 million kilometres from Saturn. The burn went smoothly and reduced Cassini-Huygens’s relative velocity to Saturn while the spacecraft passed only 19 000 kilometres from the planet’s upper clouds. After completion of the burn, the probe was tilted first toward Earth to confirm insertion and then toward Saturn’s rings in order to take close-up pictures as it flew only a few thousand kilometres above them. This was a unique opportunity to attempt to discriminate individual components within the rings, as Cassini is not planned to come this close to them again. The orbiter’s instruments also took advantage of its proximity to the planet to make an in-depth study of its atmosphere and environment. A second crossing of the ring plane took place at 05:50 UT. The spacecraft is in perfect shape to begin its tour of the Saturnian system with at least 76 orbits around the ringed planet and 52 close encounters with seven of its 31 known moons. This tour actually began before insertion with a close fly-by of an eighth moon, Phoebe, on 11 June. The primary target for Cassini-Huygens will be the largest of these moons, Titan, with a first fly-by at an altitude of 1200 kilometres on 26 October. During the coming months, ESA’s scientists will prepare for the release of their main contribution to the mission, the Huygens probe, which will be released on 25 December to enter the atmosphere of Titan on 14 January 2005. Built for ESA by an industrial team led by Alcatel Space, this 320 kilogram probe carries six science instruments to analyse and characterise the atmosphere and its dynamics during its descent. If the probe survives the impact on reaching the surface, it will also analyse the physical properties of its environment after landing. Actually bigger than Mercury, Titan features a hazy nitrogen-rich atmosphere containing carbon-based compounds. The chemical environment on Titan is thought to be similar to that of Earth before life, although colder (-180°C) and lacking liquid water. The in situ results from Huygens, combined with global observations from repeated fly-bys of Titan by the Cassini orbiter, are expected to help us understand the evolution of the early Earth's atmosphere and provide clues about the mechanisms that led to the dawn of life on our planet. The Cassini orbiter, the largest and most complex deep-space probe ever launched, carries 12 science instruments developed by US and international teams to conduct in-depth studies of Saturn, Titan, the icy moons, the ring system and the magnetospheric environment. Two of the orbiter’s instruments were provided by Europe. “More than twenty years have passed since Pioneer 11 and the Voyagers gave us a first glimpse of Saturn, as they crossed this complex system in only a few days,” explained Prof. Southwood, who is also principal investigator for Cassini’s magnetometer. “Now, with Cassini, we are here to stay, watch and investigate. And with Huygens we will go even deeper and further, not only plunging into an extraterrestrial atmosphere but also an atmosphere like the early Earth’s. This means we are travelling billions of years back into our own past to investigate one of the Universe’s best kept secrets: where we came from.” The Cassini-Huygens mission is a co-operation between NASA, ESA, the European Space Agency and ASI, the Italian space agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, is managing the mission for NASA’s Office of Space Science, Washington.

48 CFR 52.203-13 - Contractor Code of Business Ethics and Conduct.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Business Ethics and Conduct. 52.203-13 Section 52.203-13 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.203-13 Contractor Code of Business Ethics and Conduct. As prescribed in 3.1004(a), insert the following clause: Contractor Code of Business Ethics and Conduct (APR 2010) (a) Definitions...

48 CFR 52.203-13 - Contractor Code of Business Ethics and Conduct.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Business Ethics and Conduct. 52.203-13 Section 52.203-13 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.203-13 Contractor Code of Business Ethics and Conduct. As prescribed in 3.1004(a), insert the following clause: Contractor Code of Business Ethics and Conduct (APR 2010) (a) Definitions...

48 CFR 52.203-13 - Contractor Code of Business Ethics and Conduct.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Business Ethics and Conduct. 52.203-13 Section 52.203-13 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.203-13 Contractor Code of Business Ethics and Conduct. As prescribed in 3.1004(a), insert the following clause: Contractor Code of Business Ethics and Conduct (APR 2010) (a) Definitions...

48 CFR 52.203-13 - Contractor Code of Business Ethics and Conduct.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Business Ethics and Conduct. 52.203-13 Section 52.203-13 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.203-13 Contractor Code of Business Ethics and Conduct. As prescribed in 3.1004(a), insert the following clause: Contractor Code of Business Ethics and Conduct (APR 2010) (a) Definitions...

48 CFR 52.203-13 - Contractor Code of Business Ethics and Conduct.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Business Ethics and Conduct. 52.203-13 Section 52.203-13 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.203-13 Contractor Code of Business Ethics and Conduct. As prescribed in 3.1004(a), insert the following clause: Contractor Code of Business Ethics and Conduct (APR 2010) (a) Definitions...

Radiometric Measurements of the Thermal Conductivity of Complex Planetary-like Materials

NASA Astrophysics Data System (ADS)

Piqueux, S.; Christensen, P. R.

2012-12-01

Planetary surface temperatures and thermal inertias are controlled by the physical and compositional characteristics of the surface layer material, which result from current and past geological activity. For this reason, temperature measurements are often acquired because they provide fundamental constraints on the geological history and habitability. Examples of regolith properties affecting surface temperatures and inertias are: grain sizes and mixture ratios, solid composition in the case of ices, presence of cement between grains, regolith porosity, grain roughness, material layering etc.. Other important factors include volatile phase changes, and endogenic or exogenic heat sources (i.e. geothermal heat flow, impact-related heat, biological activity etc.). In the case of Mars, the multitude of instruments observing the surface temperature at different spatial and temporal resolutions (i.e. IRTM, Thermoskan, TES, MiniTES, THEMIS, MCS, REMS, etc.) in conjunction with other instruments allows us to probe and characterize the thermal properties of the surface layer with an unprecedented resolution. While the derivation of thermal inertia values from temperature measurements is routinely performed by well-established planetary regolith numerical models, constraining the physical properties of the surface layer from thermal inertia values requires the additional step of laboratory measurements. The density and specific heat are usually constant and sufficiently well known for common geological materials, but the bulk thermal conductivity is highly variable as a function of the physical characteristics of the regolith. Most laboratory designs do not allow an investigation of the thermal conductivity of complex regolith configurations similar to those observed on planetary surfaces (i.e. cemented material, large grains, layered material, and temperature effects) because the samples are too small and need to be soft to insert heating or measuring devices. For this reason, we have built a new type of apparatus to measure the thermal conductivity of sample significantly larger than previous apparatus under planetary conditions of atmosphere and gas composition. Samples' edges are cooled down from room to LN2 temperature and the surface material temperature is recorded by an infrared camera without inserting thermocouples or heat sources. Sample surface cooling trends are fit with finite element models of heat transfer to retrieve the material thermal conductivity. Preliminary results confirm independent numerical modeling results predicting the thermal conductivity of complex materials: the thermal inertia of particulate material under Mars conditions is temperature-dependent, small amounts of cements significantly increase the bulk conductivity and inertia of particulate material, and one-grain-thick armors similar to those observed by the Mars Exploration Rovers behave like a thin highly conductive layer that does not significantly influence apparent thermal inertias. These results are used to further our interpretation of Martian temperature observations. For example local amounts of subsurface water ice or the fraction of cementing phase in the global Martian duricrust can be constrained; the search for subtle changes in near-surface heat flow can be performed more accurately, and surface thermal inertias under various atmospheric conditions of pressure and gas composition can be predicted.

Development of Metal Plate with Internal Structure Utilizing the Metal Injection Molding (MIM) Process.

PubMed

Shin, Kwangho; Heo, Youngmoo; Park, Hyungpil; Chang, Sungho; Rhee, Byungohk

2013-12-12

In this study, we focus on making a double-sided metal plate with an internal structure, such as honeycomb. The stainless steel powder was used in the metal injection molding (MIM) process. The preliminary studies were carried out for the measurement of the viscosity of the stainless steel feedstock and for the prediction of the filling behavior through Computer Aided Engineering (CAE) simulation. PE (high density polyethylene (HDPE) and low density polyethylene (LDPE)) and polypropylene (PP) resins were used to make the sacrificed insert with a honeycomb structure using a plastic injection molding process. Additionally, these sacrificed insert parts were inserted in the metal injection mold, and the metal injection molding process was carried out to build a green part with rectangular shape. Subsequently, debinding and sintering processes were adopted to remove the sacrificed polymer insert. The insert had a suitable rigidity that was able to endure the filling pressure. The core shift analysis was conducted to predict the deformation of the insert part. The 17-4PH feedstock with a low melting temperature was applied. The glass transition temperature of the sacrificed polymer insert would be of a high grade, and this insert should be maintained during the MIM process. Through these processes, a square metal plate with a honeycomb structure was made.

Development of Metal Plate with Internal Structure Utilizing the Metal Injection Molding (MIM) Process

PubMed Central

Shin, Kwangho; Heo, Youngmoo; Park, Hyungpil; Chang, Sungho; Rhee, Byungohk

2013-01-01

In this study, we focus on making a double-sided metal plate with an internal structure, such as honeycomb. The stainless steel powder was used in the metal injection molding (MIM) process. The preliminary studies were carried out for the measurement of the viscosity of the stainless steel feedstock and for the prediction of the filling behavior through Computer Aided Engineering (CAE) simulation. PE (high density polyethylene (HDPE) and low density polyethylene (LDPE)) and polypropylene (PP) resins were used to make the sacrificed insert with a honeycomb structure using a plastic injection molding process. Additionally, these sacrificed insert parts were inserted in the metal injection mold, and the metal injection molding process was carried out to build a green part with rectangular shape. Subsequently, debinding and sintering processes were adopted to remove the sacrificed polymer insert. The insert had a suitable rigidity that was able to endure the filling pressure. The core shift analysis was conducted to predict the deformation of the insert part. The 17-4PH feedstock with a low melting temperature was applied. The glass transition temperature of the sacrificed polymer insert would be of a high grade, and this insert should be maintained during the MIM process. Through these processes, a square metal plate with a honeycomb structure was made. PMID:28788427

Implant Insertion Torque: Its Role in Achieving Primary Stability of Restorable Dental Implants.

PubMed

Greenstein, Gary; Cavallaro, John

2017-02-01

A literature review was conducted to determine the role of insertion torque in attaining primary stability of dental implants. The review is comprised of articles that discussed the amount of torque needed to achieve primary implant stability in healed ridges and fresh extraction sockets prior to immediate implant loading. Studies were appraised that addressed the effects of minimum and maximum forces that can be used to successfully place implants. The minimum torque that can be employed to attain primary stability is undefined. Forces ≥30 Ncm are routinely used to place implants into healed ridges and fresh extraction sockets prior to immediate loading of implants. Increased insertion torque (≥50 Ncm) reduces micromotion and does not appear to damage bone. In general, the healing process after implant insertion provides a degree of biologic stability that is similar whether implants are placed with high or low initial insertion torque. Primary stability is desirable when placing implants, but the absence of micromotion is what facilitates predictable implant osseointegration. Increased insertion torque helps achieve primary stability by reducing implant micromotion. Furthermore, tactile information provided by the first surgical twist drill can aid in selecting the initial insertion torque to achieve predictable stability of inserted dental implants.

Influence of native defects on structural and electronic properties of magnesium silicide

NASA Astrophysics Data System (ADS)

Hirayama, Naomi; Iida, Tsutomu; Nishio, Keishi; Kogo, Yasuo; Takarabe, Kenji; Hamada, Noriaki

2017-05-01

The narrow-gap semiconductor magnesium silicide (Mg2Si) is a promising candidate for mid-temperature (500-800 K) thermoelectric applications. Mg2Si exhibits intrinsic n-type conductivity because of its interstitial Mg defects and is generally doped with n-type dopants; however, the synthesis of p-type Mg2Si has proven difficult. In the present study, we examined several types of defects, such as vacancies and the insertion of constituent atoms (Mg and Si) into crystals, to elucidate their stability in Mg2Si and their influence on its electronic states. A first-principles calculation has revealed that the insertion of Mg into a cell is the most stable and causes n-type conductivity in terms of formation energy. In contrast, the vacancy of Mg produces hole doping although its formation energy per conventional unit cell is approximately 0.07 eV higher than that of the insertion of Mg, at their concentration of 1.04 at. %. Furthermore, the insertion and vacancy of Si atoms generate electrons with higher formation energies compared to the Mg-related defects. As these defects alter the carrier concentration, they can compensate for intentional doping because of the added impurity atoms.

Ultrasonic airborne insertion loss measurements at normal incidence (L).

PubMed

Farley, Jayrin; Anderson, Brian E

2010-12-01

Transmission loss and insertion loss measurements of building materials at audible frequencies are commonly made using plane wave tubes or as a panel between reverberant rooms. These measurements provide information for noise isolation control in architectural acoustics and in product development. Airborne ultrasonic sound transmission through common building materials has not been fully explored. Technologies and products that utilize ultrasonic frequencies are becoming increasingly more common, hence the need to conduct such measurements. This letter presents preliminary measurements of the ultrasonic insertion loss levels for common building materials over a frequency range of 28-90 kHz using continuous-wave excitation.

From the Cover: Understanding nature's design for a nanosyringe

NASA Astrophysics Data System (ADS)

Lopez, Carlos F.; Nielsen, Steve O.; Moore, Preston B.; Klein, Michael L.

2004-03-01

Synthetic and natural peptide assemblies can possess transport or conductance activity across biomembranes through the formation of nanopores. The fundamental mechanisms of membrane insertion necessary for antimicrobial or synthetic pore formation are poorly understood. We observe a lipid-assisted mechanism for passive insertion into a model membrane from molecular dynamics simulations. The assembly used in the study, a generic nanotube functionalized with hydrophilic termini, is assisted in crossing the membrane core by transleaflet lipid flips. Lipid tails occlude a purely hydrophobic nanotube. The observed insertion mechanism requirements for hydrophobic-hydrophilic matching have implications for the design of synthetic channels and antibiotics.

Generation of highly N-type, defect passivated transition metal oxides using plasma fluorine insertion

DOEpatents

Baker, L. Robert; Seo, Hyungtak; Hervier, Antoine; Somorjai, Gabor A.

2016-04-12

A new composition of matter is disclosed wherein oxygen vacancies in a semiconducting transition metal oxide such as titanium dioxide are filled with a halogen such as Fluorine, whereby the conductivity of the composition is greatly enhanced, while at the same time the chemical stability of the composition is greatly improved. Stoichiometric titanium dioxide having less than 3 % oxygen vacancies is subject to fluorine insertion such that oxygen vacancies are filled, limited amounts of fluorine replace additional oxygen atoms and fluorine interstitially inserts into the body of the TiO.sub.2 composition.

Assessment of Oral Conditions and Quality of Life in Morbid Obese and Normal Weight Individuals: A Cross-Sectional Study.

PubMed

Yamashita, Joselene Martinelli; Moura-Grec, Patrícia Garcia de; Freitas, Adriana Rodrigues de; Sales-Peres, Arsênio; Groppo, Francisco Carlos; Ceneviva, Reginaldo; Sales-Peres, Sílvia Helena de Carvalho

2015-01-01

The aim of this study was to identify the impact of oral disease on the quality of life of morbid obese and normal weight individuals. Cohort was composed of 100 morbid-obese and 50 normal-weight subjects. Dental caries, community periodontal index, gingival bleeding on probing (BOP), calculus, probing pocket depth, clinical attachment level, dental wear, stimulated salivary flow, and salivary pH were used to evaluate oral diseases. Socioeconomic and the oral impacts on daily performances (OIDP) questionnaires showed the quality of life in both groups. Unpaired Student, Fisher's Exact, Chi-Square, Mann-Whitney, and Multiple Regression tests were used (p<0.05). Obese showed lower socio-economic level than control group, but no differences were found considering OIDP. No significant differences were observed between groups considering the number of absent teeth, bruxism, difficult mastication, calculus, initial caries lesion, and caries. However, saliva flow was low, and the salivary pH was changed in the obese group. Enamel wear was lower and dentine wear was higher in obese. More BOP, insertion loss, and periodontal pocket, especially the deeper ones, were found in obese subjects. The regression model showed gender, smoking, salivary pH, socio-economic level, periodontal pocket, and periodontal insertion loss significantly associated to obesity. However, both OIDP and BOP did not show significant contribution to the model. The quality of life of morbid obese was more negatively influenced by oral disease and socio-economic factors than in normal weight subjects.

Rapid metaphase and interphase detection of radiation-induced chromosome aberrations in human lymphocytes by chromosomal suppression in situ hybridization

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

Cremer, T.; Popp, S.; Emmerich, P.

1990-01-01

Chromosomal in situ suppression (CISS)-hybridization of biotinylated phage DNA-library inserts from sorted human chromosomes was used to decorate chromosomes 1 and 7 specifically from pter to qter and to detect structural aberrations of these chromosomes in irradiated human peripheral lymphocytes. In addition, probe pUC1.77 was used to mark the 1q12 subregion in normal and aberrant chromosomes 1. Low LET radiation (60Co-gamma-rays; 1.17 and 1.33 MeV) of lymphocyte cultures was performed with various doses (D = 0, 2, 4, 8 Gy) 5 h after stimulation with phytohaemagglutinin. Irradiated cells were cultivated for an additional 67 h before Colcemid arrested metaphase spreadsmore » were obtained. Aberrations of the specifically stained chromosomes, such as deletions, dicentrics, and rings, were readily scored after in situ hybridization with either the 1q12 specific probe or DNA-library inserts. By the latter approach, translocations of the specifically stained chromosomes could also be reliably assessed. A linear increase of the percentage of specifically stained aberrant chromosomes was observed when plotted as a function of the square of the dose D. A particular advantage of this new approach is provided by the possibility to delineate numerical and structural chromosome aberrations directly in interphase nuclei. These results indicate that cytogenetic monitoring of ionizing radiation may be considerably facilitated by CISS-hybridization.« less

Mechanical Validation of an MRI Compatible Stereotactic Neurosurgery Robot in Preparation for Pre-Clinical Trials

PubMed Central

Nycz, Christopher J; Gondokaryono, Radian; Carvalho, Paulo; Patel, Nirav; Wartenberg, Marek; Pilitsis, Julie G; Fischer, Gregory S

2018-01-01

The use of magnetic resonance imaging (MRI) for guiding robotic surgical devices has shown great potential for performing precisely targeted and controlled interventions. To fully realize these benefits, devices must work safely within the tight confines of the MRI bore without negatively impacting image quality. Here we expand on previous work exploring MRI guided robots for neural interventions by presenting the mechanical design and assessment of a device for positioning, orienting, and inserting an interstitial ultrasound-based ablation probe. From our previous work we have added a 2 degree of freedom (DOF) needle driver for use with the aforementioned probe, revised the mechanical design to improve strength and function, and performed an evaluation of the mechanism’s accuracy and effect on MR image quality. The result of this work is a 7-DOF MRI robot capable of positioning a needle tip and orienting it’s axis with accuracy of 1.37 ± 0.06mm and 0.79° ± 0.41°, inserting it along it’s axis with an accuracy of 0.06 ± 0.07mm, and rotating it about it’s axis to an accuracy of 0.77° ± 1.31°. This was accomplished with no significant reduction in SNR caused by the robot’s presence in the MRI bore, ≤ 10.3% reduction in SNR from running the robot’s motors during a scan, and no visible paramagnetic artifacts. PMID:29696097

Preferential location of lidocaine and etidocaine in lecithin bilayers as determined by EPR, fluorescence and 2H NMR.

PubMed

de Paula, Eneida; Schreier, Shirley; Jarrell, Harold C; Fraceto, Leonardo Fernandes

2008-01-01

We have examined the effect of the uncharged species of lidocaine (LDC) and etidocaine (EDC) on the acyl chain moiety of egg phosphatidylcholine liposomes. Changes in membrane organization caused by both anesthetics were detected through the use of EPR spin labels (5, 7 and 12 doxyl stearic acid methyl ester) or fluorescence probes (4, 6, 10, 16 pyrene-fatty acids). The disturbance caused by the LA was greater when the probes were inserted in more external positions of the acyl chain and decreased towards the hydrophobic core of the membrane. The results indicate a preferential insertion of LDC at the polar interface of the bilayer and in the first half of the acyl chain, for EDC. Additionally, (2)H NMR spectra of multilamellar liposomes composed by acyl chain-perdeutero DMPC and EPC (1:4 mol%) allowed the determination of the segmental order (S(mol)) and dynamics (T(1)) of the acyl chain region. In accordance to the fluorescence and EPR results, changes in molecular orientation and dynamics are more prominent if the LA preferential location is more superficial, as for LDC while EDC seems to organize the acyl chain region between carbons 2-8, which is indicative of its positioning. We propose that the preferential location of LDC and EDC inside the bilayers creates a "transient site", which is related to the anesthetic potency since it could modulate the access of these molecules to their binding site(s) in the voltage-gated sodium channel.

Self-tapping ability of carbon fibre reinforced polyetheretherketone suture anchors.

PubMed

Feerick, Emer M; Wilson, Joanne; Jarman-Smith, Marcus; Ó'Brádaigh, Conchur M; McGarry, J Patrick

2014-10-01

An experimental and computational investigation of the self-tapping ability of carbon fibre reinforced polyetheretherketone (CFR-PEEK) has been conducted. Six CFR-PEEK suture anchor designs were investigated using PEEK-OPTIMA® Reinforced, a medical grade of CFR-PEEK. Experimental tests were conducted to investigate the maximum axial force and torque required for self-taping insertion of each anchor design. Additional experimental tests were conducted for some anchor designs using pilot holes. Computational simulations were conducted to determine the maximum stress in each anchor design at various stages of insertion. Simulations also were performed to investigate the effect of wall thickness in the anchor head. The maximum axial force required to insert a self-tapping CFR-PEEK suture anchor did not exceed 150 N for any anchor design. The maximum torque required to insert a self-tapping CFR-PEEK suture anchor did not exceed 0.8 Nm. Computational simulations reveal significant stress concentrations in the region of the anchor tip, demonstrating that a re-design of the tip geometry should be performed to avoid fracture during self-tapping, as observed in the experimental component of this study. This study demonstrates the ability of PEEK-OPTIMA Reinforced suture anchors to self-tap polyurethane foam bone analogue. This provides motivation to further investigate the self-tapping ability of CFR-PEEK suture anchors in animal/cadaveric bone. An optimised design for CFR-PEEK suture anchors offers the advantages of radiolucency, and mechanical properties similar to bone with the ability to self-tap. This may have positive implications for reducing surgery times and the associated costs with the procedure. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Inductive Measurement of Plasma Jet Electrical Conductivity

NASA Technical Reports Server (NTRS)

Turner, Matthew W.; Hawk, Clark W.; Litchford, Ron J.

2005-01-01

An inductive probing scheme, originally developed for shock tube studies, has been adapted to measure explosive plasma jet conductivities. In this method, the perturbation of an applied magnetic field by a plasma jet induces a voltage in a search coil, which, in turn, can be used to infer electrical conductivity through the inversion of a Fredholm integral equation of the first kind. A 1-inch diameter probe was designed and constructed, and calibration was accomplished by firing an aluminum slug through the probe using a light-gas gun. Exploratory laboratory experiments were carried out using plasma jets expelled from 15-gram high explosive shaped charges. Measured conductivities were in the range of 3 kS/m for unseeded octol charges and 20 kS/m for seeded octol charges containing 2% potassium carbonate by mass.

Cloning, sequencing, and expression of the Pseudomonas testosteroni gene encoding 3-oxosteroid delta 1-dehydrogenase.

PubMed Central

Plesiat, P; Grandguillot, M; Harayama, S; Vragar, S; Michel-Briand, Y

1991-01-01

Pseudomonas testosteroni ATCC 17410 is able to grow on testosterone. This strain was mutagenized by Tn5, and 41 mutants defective in the utilization of testosterone were isolated. One of them, called mutant 06, expressed 3-oxosteroid delta 1- and 3-oxosteroid delta 4-5 alpha-dehydrogenases only at low levels. The DNA region around the Tn5 insertion in mutant 06 was cloned into pUC19, and the 1-kbp EcoRI-BamHI segment neighbor to the Tn5 insertion was used to probe DNA from the wild-type strain. The probe hybridized to a 7.8-kbp SalI fragment. Plasmid pTES5, which is a pUC19 derivative containing this 7.8-kbp SalI fragment, was isolated after the screening by the 1-kbp EcoRI-BamHI probe. This plasmid expressed delta 1-dehydrogenase in Escherichia coli cells. The 2.2-kbp KpnI-KpnI segment of pTES5 was subcloned into pUC18, and pTEK21 was constructed. In E. coli containing the lacIq plasmid pRG1 and pTEK21, the expression of delta 1-dehydrogenase was induced by isopropyl-beta-D-thiogalactopyranoside (IPTG). The induced level was about 40 times higher than the induced level in P. testosteroni. Delta 1-Dehydrogenase synthesized in E. coli was localized in the inner membrane fraction. The minicell experiments showed that a 59-kDa polypeptide was synthesized from pTEK21, and this polypeptide was located in the inner membrane fraction. The complete nucleotide sequence of the 2.2-kbp KpnI-KpnI segment of pTEK21 was determined. An open reading frame which encodes a 62.4-kDa polypeptide and which is preceded by a Shine-Dalgarno-like sequence was identified. The first 44 amino acids of the putative product exhibited significant sequence similarity to the N-terminal sequences of lipoamide dehydrogenases. Images FIG. 4 PMID:1657885

Coupled modes, frequencies and fields of a dielectric resonator and a cavity using coupled mode theory

NASA Astrophysics Data System (ADS)

Elnaggar, Sameh Y.; Tervo, Richard; Mattar, Saba M.

2014-01-01

Probes consisting of a dielectric resonator (DR) inserted in a cavity are important integral components of electron paramagnetic resonance (EPR) spectrometers because of their high signal-to-noise ratio. This article studies the behavior of this system, based on the coupling between its dielectric and cavity modes. Coupled-mode theory (CMT) is used to determine the frequencies and electromagnetic fields of this coupled system. General expressions for the frequencies and field distributions are derived for both the resulting symmetric and anti-symmetric modes. These expressions are applicable to a wide range of frequencies (from MHz to THz). The coupling of cavities and DRs of various sizes and their resonant frequencies are studied in detail. Since the DR is situated within the cavity then the coupling between them is strong. In some cases the coupling coefficient, κ, is found to be as high as 0.4 even though the frequency difference between the uncoupled modes is large. This is directly attributed to the strong overlap between the fields of the uncoupled DR and cavity modes. In most cases, this improves the signal to noise ratio of the spectrometer. When the DR and the cavity have the same frequency, the coupled electromagnetic fields are found to contain equal contributions from the fields of the two uncoupled modes. This situation is ideal for the excitation of the probe through an iris on the cavity wall. To verify and validate the results, finite element simulations are carried out. This is achieved by simulating the coupling between a cylindrical cavity's TE011 and the dielectric insert's TE01δ modes. Coupling between the modes of higher order is also investigated and discussed. Based on CMT, closed form expressions for the fields of the coupled system are proposed. These expressions are crucial in the analysis of the probe's performance.

Nucleic acid probes as a diagnostic method for tick-borne hemoparasites of veterinary importance.

PubMed

Figueroa, J V; Buening, G M

1995-03-01

An increased number of articles on the use of nucleic acid-based hybridization techniques for diagnostic purposes have been recently published. This article reviews nucleic acid-based hybridization as an assay to detect hemoparasite infections of economic relevance in veterinary medicine. By using recombinant DNA techniques, selected clones containing inserts of Anaplasma, Babesia, Cowdria or Theileria genomic DNA sequences have been obtained, and they are now available to be utilized as specific, highly sensitive DNA or RNA probes to detect the presence of the hemoparasite DNA in an infected animal. Either in an isotopic or non-isotopic detection system, probes have allowed scientists to test for--originally in samples collected from experimentally infected animals and later in samples collected in the field--the presence of hemoparasites during the prepatent, patent, convalescent, and chronic periods of the infection in the host. Nucleic acid probes have given researchers the opportunity to carry out genomic analysis of parasite DNA to differentiate hemoparasite species and to identify genetically distinct populations among and within isolates, strains and clonal populations. Prevalence of parasite infection in the tick vector can now be accomplished more specifically with the nucleic acid probes. Lately, with the advent of the polymerase chain reaction technique, small numbers of hemoparasites can be positively identified in the vertebrate host and tick vector. These techniques can be used to assess the veterinary epidemiological situation in a particular geographical region for the planning of control measures.

New Concepts of Fluorescent Probes for Specific Detection of DNA Sequences: Bis-Modified Oligonucleotides in Excimer and Exciplex Detection

PubMed Central

Gbaj, A; Bichenkova, EV; Walsh, L; Savage, HE; Sardarian, AR; Etchells, LL; Gulati, A; Hawisa, S; Douglas, KT

2009-01-01

The detection of single base mismatches in DNA is important for diagnostics, treatment of genetic diseases, and identification of single nucleotide polymorphisms. Highly sensitive, specific assays are needed to investigate genetic samples from patients. The use of a simple fluorescent nucleoside analogue in detection of DNA sequence and point mutations by hybridisation in solution is described in this study. The 5′-bispyrene and 3′-naphthalene oligonucleotide probes form an exciplex on hybridisation to target in water and the 5′-bispyrene oligonucleotide alone is an adequate probe to determine concentration of target present. It was also indicated that this system has a potential to identify mismatches and insertions. The aim of this work was to investigate experimental structures and conditions that permit strong exciplex emission for nucleic acid detectors, and show how such exciplexes can register the presence of mismatches as required in SNP analysis. This study revealed that the hybridisation of 5′-bispyrenyl fluorophore to a DNA target results in formation of a fluorescent probe with high signal intensity change and specificity for detecting a complementary target in a homogeneous system. Detection of SNP mutations using this split-probe system is a highly specific, simple, and accessible method to meet the rigorous requirements of pharmacogenomic studies. Thus, it is possible for the system to act as SNP detectors and it shows promise for future applications in genetic testing. PMID:21483539

Multi-function diamond film fiber optic probe and measuring system employing same

DOEpatents

Young, J.P.

1998-11-24

A fused fiber optic probe having a protective cover, a fiber optic probe system, and embodiments thereof for conducting electromagnetic spectral measurements are disclosed. The fused fiber optic probe comprises a probe tip having a specific geometrical configuration, an exciting optical fiber and at least one collection optical fiber fused within a housing, preferably silica, with a protective cover disposed over at least a portion of the probe tip. The specific geometrical configurations in which the probe tip can be shaped include a slanted probe tip with an angle greater than 0{degree}, an inverted cone-shaped probe tip, and a lens head. 9 figs.

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

Hinderliter, Paul M.; Thrall, Karla D.; Corley, Rick A.

Vinyl acetate has been shown to induce nasal lesions in rodents in inhalation bioassays. A physiologically based pharmacokinetic (PBPK) model for vinyl acetate has been used in human risk assessment, but previous in vivo validation was conducted only in rats. Controlled human exposures to vinyl acetate were conducted to provide validation data for the application of the model in humans. Five volunteers were exposed to 1, 5, and 10 ppm 13 C1 , 13 C2 vinyl acetate via inhalation. A probe inserted into thenasopharyngeal region sampled both 13 C1 , 13 C2 vinyl acetate and the major metabolite 13 C1more » , 13 C2 acetaldehyde during rest and light exercise. Nasopharyngeal air concentrations were analyzed in real time by ion trap mass spectrometry (MS/MS). Experimental concentrations of both vinyl acetate and acetaldehyde were then compared to predicted concentrations calculated from the previously published human model. Model predictions of vinyl acetate nasal extraction compared favorably with measured values of vinyl acetate, as did predictions of nasopharyngeal acetaldehyde when compared to measured acetaldehyde. The results showed that the current PBPK model structure and parameterization are appropriate for vinyl acetate. These analyses were conducted from 1 to 10 ppm vinyl acetate, a range relevant to workplace exposure standards but which would not be expected to saturate vinyl acetate metabolism. Risk assessment based on this model further concluded that 24 h per day exposures up to 1 ppm do not present concern regarding cancer or non-cancer toxicity. Validation of the vinyl acetate human PBPK model provides support for these conclusions.« less

Method for determining thermal conductivity and thermal capacity per unit volume of earth in situ

DOEpatents

Poppendiek, Heinz F.

1982-01-01

A method for determining the thermal conductivity of the earth in situ is based upon a cylindrical probe (10) having a thermopile (16) for measuring the temperature gradient between sets of thermocouple junctions (18 and 20) of the probe after it has been positioned in a borehole and has reached thermal equilibrium with its surroundings, and having means (14) for heating one set of thermocouple junctions (20) of the probe at a constant rate while the temperature gradient of the probe is recorded as a rise in temperature over several hours (more than about 3 hours). A fluid annulus thermally couples the probe to the surrounding earth. The recorded temperature curves are related to the earth's thermal conductivity, k.sub..infin., and to the thermal capacity per unit volume, (.gamma.c.sub.p).sub..infin., by comparison with calculated curves using estimates of k.sub..infin. and (.gamma.c.sub.p).sub..infin. in an equation which relates these parameters to a rise in the earth's temperature for a known and constant heating rate.

CE: Original Research: Does Certification in Vascular Access Matter? An Analysis of the PICC1 Survey.

PubMed

Chopra, Vineet; Kuhn, Latoya; Vaughn, Valerie; Ratz, David; Winter, Suzanne; Moureau, Nancy; Meyer, Britt; Krein, Sarah

2017-12-01

: Background: Although certification by an accredited agency is often a practice prerequisite in health care, it is not required of vascular access specialists who insert peripherally inserted central catheters (PICCs). Whether certification is associated with differences in practice among inserters is unknown. The purpose of this study was to gather information regarding whether certified and noncertified PICC inserters differ with respect to their practices and views about PICC use. We conducted a national survey of vascular access specialists, identifying certified PICC inserters as those who had received board certification from the Association for Vascular Access, the Infusion Nurses Society, or both. The 76-item survey asked about PICC policies and procedures at respondents' facilities, use of insertion technologies, device management, management of complications, perceptions about PICC use, and relationships with other health care providers. Additional data about respondents, including years in practice and primary practice settings, were also gathered. Bivariable comparisons were made using χ tests; two-sided α with P ≤ 0.05 was considered statistically significant. Of the 1,450 respondents in the final sample, 1,007 (69%) said they were certified inserters and 443 (31%) said they were not. Significantly higher percentages of certified than noncertified inserters reported having practiced for five or more years (78% versus 54%) and having placed 1,000 or more PICCs (58% versus 32%). Significantly more certified than noncertified inserters also reported being the vascular access lead for their facility (56% versus 44%). Reported practice patterns for insertion, care, and management of PICCs varied based on certification status. Some evidence-based practices (such as the use of ultrasound to measure catheter-to-vein ratios) were more often reported by certified inserters, while others (such as the use of maximal sterile barriers during PICC insertion) were not. Asked about their perceptions of PICC use at their institution, certified inserters reported higher percentages of inappropriate insertion and removal than noncertified inserters. Certified PICC inserters appear to be a distinct group of vascular access specialists. A better understanding of how and why practices differ between certified and noncertified inserters is necessary to ensuring safer, high-quality patient care.

Ab initio modeling of transport and thermodynamic stability for hafnia memristive devices

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

Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter

HfO 2-based memristive switching devices are currently under intensive investigation due to their high performance and mature fabrication techniques. However, several critical issues have to be addressed to bring them from lab to market. We have recently looked into two important issues with the use of density functional theory methods. One is the wide distribution of device resistance in off-states. We have modeled the switching process of a Pt-HfO 2-Pt structure for which quantized conductance was observed. Oxygen atoms moving inside a conductive oxygen vacancy filament divide the filament into several quantum wells. Device conductance changes exponentially when one oxygenmore » atom moves away from interface into filament. We propose that the high sensitivity of device conductance to the position of oxygen atoms results in the large variation of device off-state resistance. Another issue that we have recently addressed is the poor switching performance of devices based on a TiN-HfO 2-TiN structure. While recent experiments have shown that by inserting an "oxygen scavenger" metal between positive electrode and oxide significantly improves device performance, the fundamental understanding of the improvement is lacking.We provide detailed understanding how scavenger layers improve device performance. First, we show that Ta insertion facilitates formation of on-states by reducing the formation energy. Second, the inserted Ta layer reduces the Schottky barrier height in the off-states by changing interface electric dipole at the oxide electrode interface. Nevertheless, the device maintains a high on/off resistance ratio. Finally, with Ta insertion the on-state conductance becomes much less sensitive to the specific location from which the oxygen was removed from the oxide. In conclusion, our studies provide fundamental understanding needed for enabling realization of a non-volatile memory technology with reduced energy consumption.« less

Ab initio modeling of transport and thermodynamic stability for hafnia memristive devices

DOE PAGES

Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter; ...

2017-09-05

HfO 2-based memristive switching devices are currently under intensive investigation due to their high performance and mature fabrication techniques. However, several critical issues have to be addressed to bring them from lab to market. We have recently looked into two important issues with the use of density functional theory methods. One is the wide distribution of device resistance in off-states. We have modeled the switching process of a Pt-HfO 2-Pt structure for which quantized conductance was observed. Oxygen atoms moving inside a conductive oxygen vacancy filament divide the filament into several quantum wells. Device conductance changes exponentially when one oxygenmore » atom moves away from interface into filament. We propose that the high sensitivity of device conductance to the position of oxygen atoms results in the large variation of device off-state resistance. Another issue that we have recently addressed is the poor switching performance of devices based on a TiN-HfO 2-TiN structure. While recent experiments have shown that by inserting an "oxygen scavenger" metal between positive electrode and oxide significantly improves device performance, the fundamental understanding of the improvement is lacking.We provide detailed understanding how scavenger layers improve device performance. First, we show that Ta insertion facilitates formation of on-states by reducing the formation energy. Second, the inserted Ta layer reduces the Schottky barrier height in the off-states by changing interface electric dipole at the oxide electrode interface. Nevertheless, the device maintains a high on/off resistance ratio. Finally, with Ta insertion the on-state conductance becomes much less sensitive to the specific location from which the oxygen was removed from the oxide. In conclusion, our studies provide fundamental understanding needed for enabling realization of a non-volatile memory technology with reduced energy consumption.« less

Dissipationless conductance in a topological coaxial cable

NASA Astrophysics Data System (ADS)

Schuster, Thomas; Iadecola, Thomas; Chamon, Claudio; Jackiw, Roman; Pi, So-Young

2016-09-01

We present a dynamical mechanism leading to dissipationless conductance, whose quantized value is controllable in a (3+1)-dimensional electronic system. The mechanism is exemplified by a theory of Weyl fermions coupled to a Higgs field, also known as an axion insulator. We show that the insertion of an axial gauge flux can induce vortex lines in the Higgs field, similar to the development of vortices in a superconductor upon the insertion of magnetic flux. We further show that the necessary axial gauge flux can be generated using Rashba spin-orbit coupling or a magnetic field. Vortex lines in the Higgs field are known to bind chiral fermionic modes, each of which serves as a one-way channel for electric charge with conductance e2/h . Combining these elements, we present a physical picture, the "topological coaxial cable," illustrating how the value of the quantized conductance could be controlled in such an axion insulator.

Equalizer reduces SNP bias in Affymetrix microarrays.

PubMed

Quigley, David

2015-07-30

Gene expression microarrays measure the levels of messenger ribonucleic acid (mRNA) in a sample using probe sequences that hybridize with transcribed regions. These probe sequences are designed using a reference genome for the relevant species. However, most model organisms and all humans have genomes that deviate from their reference. These variations, which include single nucleotide polymorphisms, insertions of additional nucleotides, and nucleotide deletions, can affect the microarray's performance. Genetic experiments comparing individuals bearing different population-associated single nucleotide polymorphisms that intersect microarray probes are therefore subject to systemic bias, as the reduction in binding efficiency due to a technical artifact is confounded with genetic differences between parental strains. This problem has been recognized for some time, and earlier methods of compensation have attempted to identify probes affected by genome variants using statistical models. These methods may require replicate microarray measurement of gene expression in the relevant tissue in inbred parental samples, which are not always available in model organisms and are never available in humans. By using sequence information for the genomes of organisms under investigation, potentially problematic probes can now be identified a priori. However, there is no published software tool that makes it easy to eliminate these probes from an annotation. I present equalizer, a software package that uses genome variant data to modify annotation files for the commonly used Affymetrix IVT and Gene/Exon platforms. These files can be used by any microarray normalization method for subsequent analysis. I demonstrate how use of equalizer on experiments mapping germline influence on gene expression in a genetic cross between two divergent mouse species and in human samples significantly reduces probe hybridization-induced bias, reducing false positive and false negative findings. The equalizer package reduces probe hybridization bias from experiments performed on the Affymetrix microarray platform, allowing accurate assessment of germline influence on gene expression.

Probe Microphone Measurements: 20 Years of Progress

PubMed Central

Mueller, H. Gustav

2001-01-01

Probe-microphone testing was conducted in the laboratory as early as the 1940s (e.g., the classic work of Wiener and Ross, reported in 1946), however, it was not until the late 1970s that a “dispenser friendly” system was available for testing hearing aids in the real ear. In this case, the term “dispenser friendly,” is used somewhat loosely. The 1970s equipment that I'm referring to was first described in a paper that was presented by Earl Harford, Ph.D. in September of 1979 at the International Ear Clinics' Symposium in Minneapolis. At this meeting, Earl reported on his clinical experiences of testing hearing aids in the real ear using a miniature (by 1979 standards) Knowles microphone. The microphone was coupled to an interfacing impedance matching system (developed by David Preves, Ph.D., who at the time worked at Starkey Laboratories) which could be used with existing hearing aid analyzer systems (see Harford, 1980 for review of this early work). Unlike today's probe tube microphone systems, this early method of clinical real-ear measurement involved putting the entire microphone (about 4mm by 5mm by 2mm) in the ear canal down by the eardrum of the patient. If you think cerumen is a problem with probe-mic measurements today, you should have seen the condition of this microphone after a day's work! While this early instrumentation was a bit cumbersome, we quickly learned the advantages that probe-microphone measures provided in the fitting of hearing aids. We frequently ran into calibration and equalization problems, not to mention a yelp or two from the patient, but the resulting information was worth the trouble. Help soon arrived. In the early 1980s, the first computerized probe-tube microphone system, the Rastronics CCI-10 (developed in Denmark by Steen Rasmussen), entered the U.S. market (Nielsen and Rasmussen, 1984). This system had a silicone tube attached to the microphone (the transmission of sound through this tube was part of the calibration process), which eliminated the need to place the microphone itself in the ear canal. By early 1985, three or four different manufactures had introduced this new type of computerized probe-microphone equipment, and this hearing aid verification procedure became part of the standard protocol for many audiology clinics. At his time, the POGO (Prescription Of Gain and Output) and Libby 1/3 prescriptive fitting methods were at the peak of their popularity, and a revised NAL (National Acoustic Laboratories) procedure was just being introduced. All three of these methods were based on functional gain, but insertion gain easily could be substituted, and therefore, manufacturers included calculation of these prescriptive targets as part of the probe-microphone equipment software. Audiologists, frustrated with the tedious and unreliable functional gain procedure they had been using, soon developed a fascination with matching real-ear results to prescriptive targets on a computer monitor. In some ways, not a lot has changed since those early days of probe-microphone measurements. Most people who use this equipment simply run a gain curve for a couple inputs and see if it's close to prescriptive target—something that could be accomplished using the equipment from 1985. Contrary to the predictions of many, probe-mic measures have not become the “standard hearing aid verification procedure.” (Mueller and Strouse, 1995). There also has been little or no increase in the use of this equipment in recent years. In 1998, I reported on a survey that was conducted by The Hearing Journal regarding the use of probe-microphone measures (Mueller, 1998). We first looked at what percent of people dispensing hearing aids own (or have immediate access to) probe-microphone equipment. Our results showed that 23% of hearing instrument specialists and 75% of audiologists have this equipment. Among audiologists, ownership varied among work settings: 91% for hospitals/clinics, 73% for audiologists working for physicians, and 69% for audiologists in private practice. But more importantly, and a bit puzzling, was the finding that showed that nearly one half of the people who fit hearing aids and have access to this equipment, seldom or never use it. I doubt that the use rate of probe-microphone equipment has changed much in the last three years, and if anything, I suspect it has gone down. Why do I say that? As programmable hearing aids have become the standard fitting in many clinics, it is tempting to become enamoured with the simulated gain curves on the fitting screen, somehow believing that this is what really is happening in the real ear. Additionally, some dispensers have been told that you can't do reliable probe-mic testing with modern hearing aids—this of course is not true, and we'll address this issue in the Frequently Asked Questions portion of this paper. The infrequent use of probe-mic testing among dispensers is discouraging, and let's hope that probe-mic equipment does not suffer the fate of the rowing machine stored in your garage. A lot has changed over the years with the equipment itself, and there are also expanded clinical applications and procedures. We have new manufacturers, procedures, acronyms and noises. We have test procedures that allow us to accurately predict the output of a hearing aid in an infant's ear. We now have digital hearing aids, which provide us the opportunity to conduct real-ear measures of the effects of digital noise reduction, speech enhancement, adaptive feedback, expansion, and all the other features. Directional microphone hearing aids have grown in popularity and what better way to assess the real-ear directivity than with probe-mic measures? The array of assistive listening devices has expanded, and so has the role of the real-ear assessment of these products. And finally, with today's PC -based systems, we can program our hearing aids and simultaneously observe the resulting real-ear effects on the same fitting screen, or even conduct an automated target fitting using earcanal monitoring of the output. There have been a lot of changes, and we'll talk about all of them in this issue of Trends. PMID:25425897

Wind-instrument reflection function measurements in the time domain.

PubMed

Keefe, D H

1996-04-01

Theoretical and computational analyses of wind-instrument sound production in the time domain have emerged as useful tools for understanding musical instrument acoustics, yet there exist few experimental measurements of the air-column response directly in the time domain. A new experimental, time-domain technique is proposed to measure the reflection function response of woodwind and brass-instrument air columns. This response is defined at the location of sound regeneration in the mouthpiece or double reed. A probe assembly comprised of an acoustic source and microphone is inserted directly into the air column entryway using a foam plug to ensure a leak-free fit. An initial calibration phase involves measurements on a single cylindrical tube of known dimensions. Measurements are presented on an alto saxophone and euphonium. The technique has promise for testing any musical instrument air columns using a single probe assembly and foam plugs over a range of diameters typical of air-column entryways.

Genomic clones for human cholinesterase

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

Kott, M.; Venta, P.J.; Larsen, J.

1987-05-01

A human genomic library was prepared from peripheral white blood cells from a single donor by inserting an MboI partial digest into BamHI poly-linker sites of EMBL3. This library was screened using an oligolabeled human cholinesterase cDNA probe over 700 bp long. The latter probe was obtained from a human basal ganglia cDNA library. Of approximately 2 million clones screened with high stringency conditions several positive clones were identified; two have been plaque purified. One of these clones has been partially mapped using restriction enzymes known to cut within the coded region of the cDNA for human serum cholinesterase. Hybridizationmore » of the fragments and their sizes are as expected if the genomic clone is cholinesterase. Sequencing of the DNA fragments in M13 is in progress to verify the identify of the clone and the location of introns.« less

Design of a DNA chip for detection of unknown genetically modified organisms (GMOs).

PubMed

Nesvold, Håvard; Kristoffersen, Anja Bråthen; Holst-Jensen, Arne; Berdal, Knut G

2005-05-01

Unknown genetically modified organisms (GMOs) have not undergone a risk evaluation, and hence might pose a danger to health and environment. There are, today, no methods for detecting unknown GMOs. In this paper we propose a novel method intended as a first step in an approach for detecting unknown genetically modified (GM) material in a single plant. A model is designed where biological and combinatorial reduction rules are applied to a set of DNA chip probes containing all possible sequences of uniform length n, creating probes capable of detecting unknown GMOs. The model is theoretically tested for Arabidopsis thaliana Columbia, and the probabilities for detecting inserts and receiving false positives are assessed for various parameters for this organism. From a theoretical standpoint, the model looks very promising but should be tested further in the laboratory. The model and algorithms will be available upon request to the corresponding author.

Application of Stereo Vision to the Reconnection Scaling Experiment

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

Klarenbeek, Johnny; Sears, Jason A.; Gao, Kevin W.

The measurement and simulation of the three-dimensional structure of magnetic reconnection in astrophysical and lab plasmas is a challenging problem. At Los Alamos National Laboratory we use the Reconnection Scaling Experiment (RSX) to model 3D magnetohydrodynamic (MHD) relaxation of plasma filled tubes. These magnetic flux tubes are called flux ropes. In RSX, the 3D structure of the flux ropes is explored with insertable probes. Stereo triangulation can be used to compute the 3D position of a probe from point correspondences in images from two calibrated cameras. While common applications of stereo triangulation include 3D scene reconstruction and robotics navigation, wemore » will investigate the novel application of stereo triangulation in plasma physics to aid reconstruction of 3D data for RSX plasmas. Several challenges will be explored and addressed, such as minimizing 3D reconstruction errors in stereo camera systems and dealing with point correspondence problems.« less

Allele frequency distribution for the variable number of tandem repeat locus D10S28 in Tamil Nadu (south India) population.

PubMed

Pandian, S K; Kumar, S; Krishnan, M; Dharmalingam, K; Damodaran, C

1995-09-01

Allele frequencies were determined in unrelated individuals of Tamil speaking population from the Madras City (Tamil Nadu, South India) area for the polymorphic DNA locus D10S28 using the probe TBQ7. Membranes hybridized with the probe YNH24 were subjected to deprobing and were subsequently hybridized with random priming - labeled, purified inserts of TBQ7. The sizes of the fragments were grouped to 100 bp as well as to arbitrary fixed bins (Federal Bureau of Investigation / Royal Canadian Mounted Police). There were 14 bins in the latter with the most common bin being 11 (1789-1924 bp) with a frequency of 9.8%. We observed a heterozygosity of 92% comparable to Caucasian populations. The data presented here can be used as the basis for utilizing this variable number of tandem repeats (TNTR) DNA marker for paternity determinations and forensic investigations.

Pioneer Venus 1978

NASA Technical Reports Server (NTRS)

1976-01-01

An orbiter and a multiprobe spacecraft will be sent to Venus in 1978 to conduct a detailed examination of the planet's atmosphere and weather. The spin-stabilized multiprobe spacecraft consists of a bus, a large probe and three identical small probes, each carrying a complement of scientific instruments. The large probe will conduct a detailed sounding of the lower atmosphere, obtaining measurements of the clouds, atmospheric structure, wind speed, and atmospheric composition. Primary emphasis will be placed on the planet's energy balance and clouds. The three small probes will provide information on the circulation pattern of the lower atmosphere. The probe bus will provide data on the upper atmosphere and ionosphere down to an altitude of about 120 km. The orbiter is designed to globally map the atmosphere, ionosphere, and the solar wind/ionosphere interaction. In addition, it will utilize radar mapping techniques to study the surface.

Cyclic voltammetry modeling of proton transport effects on redox charge storage in conductive materials: application to a TiO2 mesoporous film.

PubMed

Kim, Y S; Balland, V; Limoges, B; Costentin, C

2017-07-21

Cyclic voltammetry is a particularly useful tool for characterizing charge accumulation in conductive materials. A simple model is presented to evaluate proton transport effects on charge storage in conductive materials associated with a redox process coupled with proton insertion in the bulk material from an aqueous buffered solution, a situation frequently encountered in metal oxide materials. The interplay between proton transport inside and outside the materials is described using a formulation of the problem through introduction of dimensionless variables that allows defining the minimum number of parameters governing the cyclic voltammetry response with consideration of a simple description of the system geometry. This approach is illustrated by analysis of proton insertion in a mesoporous TiO 2 film.

Automatic switching matrix

DOEpatents

Schlecht, Martin F.; Kassakian, John G.; Caloggero, Anthony J.; Rhodes, Bruce; Otten, David; Rasmussen, Neil

1982-01-01

An automatic switching matrix that includes an apertured matrix board containing a matrix of wires that can be interconnected at each aperture. Each aperture has associated therewith a conductive pin which, when fully inserted into the associated aperture, effects electrical connection between the wires within that particular aperture. Means is provided for automatically inserting the pins in a determined pattern and for removing all the pins to permit other interconnecting patterns.

Subsequent Tests of Trench Inserts as Barriers to Root Transmission for Control of Oak Wilt in Texas Live Oaks

Treesearch

A. Dan Wilson; D.G. Lester

1997-01-01

Second-year field evaluations of four trench insert materials, including water-permeable Typar® polypropylene spunbonded fabric, Biobarrier® or Typar® with trifluralin-impregnated nodules, and water-impermeable polyethylene Geomembrane liners of two thicknesses (20 and 30 mil), were conducted to further test the effectiveness of these physical and/or chemical barriers...

Clinical training alone is not sufficient for reducing barriers to IUD provision among private providers in Pakistan

PubMed Central

2011-01-01

Background IUD uptake remains low in Pakistan, in spite of three major efforts to introduce the IUD since the 1960s, the most recent of these being through the private sector. This study examines barriers to IUD recommendation and provision among private providers in Pakistan. Methods A facility-based survey was conducted among randomly selected private providers who were members of the Greenstar network and among similar providers located within 2 Kilometers. In total, 566 providers were interviewed in 54 districts of Pakistan. Logistic regression analysis was conducted to determine whether correct knowledge regarding the IUD, self-confidence in being able to insert the IUD, attitudes towards suitability of candidates for the IUD and medical safety concerns were influenced by provider type (physician vs. Lady Health Visitor), whether the provider had received clinical training in IUD insertion in the last three years, membership of the Greenstar network and experience in IUD insertion. OLS regression was used to identify predictors of provider productivity (measured by IUD insertions conducted in the month before the survey). Results Private providers consider women with children and in their peak reproductive years to be ideal candidates for the IUD. Women below age 19, above age 40 and nulliparous women are not considered suitable IUD candidates. Provider concerns about medical safety, side-effects and client satisfaction associated with the IUD are substantial. Providers' experience in terms of the number of IUDs inserted in their careers, appears to improve knowledge, self-confidence in the ability provide the IUD and to lower age-related attitudinal barriers towards IUD recommendation. Physicians have greater medical safety concerns about the IUD than Lady Health Visitors. Clinical training does not have a consistent positive effect on lowering barriers to IUD recommendation. Membership of the Greenstar network also has little effect on lowering these barriers. Providers' barriers to IUD recommendation significantly lower their monthly IUD insertions. Conclusions Technical training interventions do not reduce providers' attitudinal barriers towards IUD provision. Formative research is needed to better understand reasons for the high levels of provider barriers to IUD provision. "Non-training" interventions should be designed to lower these barriers. PMID:22208449

Teaching Special Education Teachers How to Conduct Functional Analysis in Natural Settings

ERIC Educational Resources Information Center

Erbas, Dilek; Tekin-Iftar, Elif; Yucesoy, Serife

2006-01-01

Effects of a training program utilized to teach how to conduct functional analysis process to teachers of children with developmental disabilities was examined. Furthermore, teachers' opinions regarding this process were investigated. A multiple probe design across subjects with probe conditions was used. Teacher training was in two phases. In the…

Probing the mechanistic role of the long α-helix in subunit L of respiratory Complex I from Escherichia coli by site-directed mutagenesis

PubMed Central

Belevich, Galina; Knuuti, Juho; Verkhovsky, Michael I; Wikström, Mårten; Verkhovskaya, Marina

2011-01-01

The C-terminus of the NuoL subunit of Complex I includes a long amphipathic α-helix positioned parallel to the membrane, which has been considered to function as a piston in the proton pumping machinery. Here, we have introduced three types of mutations into the nuoL gene to test the piston-like function. First, NuoL was truncated at its C- and N-termini, which resulted in low production of a fragile Complex I with negligible activity. Second, we mutated three partially conserved residues of the amphipathic α-helix: Asp and Lys residues and a Pro were substituted for acidic, basic or neutral residues. All these variants exhibited almost a wild-type phenotype. Third, several substitutions and insertions were made to reduce rigidity of the amphipathic α-helix, and/or to change its geometry. Most insertions/substitutions resulted in a normal growth phenotype, albeit often with reduced stability of Complex I. In contrast, insertion of six to seven amino acids at a site of the long α-helix between NuoL and M resulted in substantial loss of proton pumping efficiency. The implications of these results for the proton pumping mechanism of Complex I are discussed. PMID:22060017

INS studies of Cobalt-Copper Catalyst for the Conversion of Syngas to Higher Oxygenates

NASA Astrophysics Data System (ADS)

Sprunger, Phillip; Wang, Zi; Patterson, Matthew; Kurtz, Richard; Spivey, James

Cobalt-copper catalysts have been proposed for the synthesis of ethanol and higher oxygenates as a substitute of Rh and other high-cost noble metal catalysts. Two types of sites with atomic proximity are needed to form higher oxygenates: one to dissociate CO and a second to insert CO to the intermediates to form the CHxCO intermediate. Metallic cobalt is responsible for CO dissociation, while the nature of the site for CO insertion is still under study. We have utilized inelastic neutron scattering (INS) at the VISION beamline at SNS to probe intermediate surface species of this cobalt-copper catalyst. This unique technique allows for elucidation of mechanistic details of the CO insertion and subsequent CHxCO intermediate formation on the metal surfaces (Co0, Co2C and/or Cu0) . In addition to XRD and EXAFS which show a unique surface Co-C carbide formation, a combination of both INS and computational modeling indicate that the active site for CHxCO intermediates. Sponsored through the Louisiana Consortium for Neutron Scattering, DOE No. DE-SC0012432 with additional support from the LA BOR; also ORNL's Spallation Neutron Source (VISION Beamline), DOE-BES under Contract No. DE-AC0500OR22725.

Development of a duplex real-time RT-qPCR assay to monitor genome replication, gene expression and gene insert stability during in vivo replication of a prototype live attenuated canine distemper virus vector encoding SIV gag.

PubMed

Coleman, John W; Wright, Kevin J; Wallace, Olivia L; Sharma, Palka; Arendt, Heather; Martinez, Jennifer; DeStefano, Joanne; Zamb, Timothy P; Zhang, Xinsheng; Parks, Christopher L

2015-03-01

Advancement of new vaccines based on live viral vectors requires sensitive assays to analyze in vivo replication, gene expression and genetic stability. In this study, attenuated canine distemper virus (CDV) was used as a vaccine delivery vector and duplex 2-step quantitative real-time RT-PCR (RT-qPCR) assays specific for genomic RNA (gRNA) or mRNA have been developed that concurrently quantify coding sequences for the CDV nucleocapsid protein (N) and a foreign vaccine antigen (SIV Gag). These amplicons, which had detection limits of about 10 copies per PCR reaction, were used to show that abdominal cavity lymphoid tissues were a primary site of CDV vector replication in infected ferrets, and importantly, CDV gRNA or mRNA was undetectable in brain tissue. In addition, the gRNA duplex assay was adapted for monitoring foreign gene insert genetic stability during in vivo replication by analyzing the ratio of CDV N and SIV gag genomic RNA copies over the course of vector infection. This measurement was found to be a sensitive probe for assessing the in vivo genetic stability of the foreign gene insert. Copyright © 2014 Elsevier B.V. All rights reserved.

Neutron Reflectometry Study of the Conformation of HIV Nef Bound to Lipid Membranes

PubMed Central

Kent, Michael S.; Murton, Jaclyn K.; Sasaki, Darryl Y.; Satija, Sushil; Akgun, Bulent; Nanda, Hirsh; Curtis, Joseph E.; Majewski, Jaroslaw; Morgan, Christopher R.; Engen, John R.

2010-01-01

Nef is an HIV-1 accessory protein that directly contributes to AIDS progression. Nef is myristoylated on the N-terminus, associates with membranes, and may undergo a transition from a solution conformation to a membrane-associated conformation. It has been hypothesized that conformational rearrangement enables membrane-associated Nef to interact with cellular proteins. Despite its medical relevance, to our knowledge there is no direct information about the conformation of membrane-bound Nef. In this work, we used neutron reflection to reveal what we believe are the first details of the conformation of membrane-bound Nef. The conformation of Nef was probed upon binding to Langmuir monolayers through the interaction of an N-terminal His tag with a synthetic metal-chelating lipid, which models one of the possible limiting cases for myr-Nef. The data indicate that residues are inserted into the lipid headgroups during interaction, and that the core domain lies directly against the lipid headgroups, with a thickness of ∼40 Å. Binding of Nef through the N-terminal His tag apparently facilitates insertion of residues, as no insertion occurred upon binding of Nef through weak electrostatic interactions in the absence of the specific interaction through the His tag. PMID:20858440