Low-complexity video encoding method for wireless image transmission in capsule endoscope.

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Takizawa, Kenichi; Hamaguchi, Kiyoshi

2010-01-01

This paper presents a low-complexity video encoding method applicable for wireless image transmission in capsule endoscopes. This encoding method is based on Wyner-Ziv theory, in which side information available at a transmitter is treated as side information at its receiver. Therefore complex processes in video encoding, such as estimation of the motion vector, are moved to the receiver side, which has a larger-capacity battery. As a result, the encoding process is only to decimate coded original data through channel coding. We provide a performance evaluation for a low-density parity check (LDPC) coding method in the AWGN channel.

Motion analysis for duplicate frame removal in wireless capsule endoscope

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Lee, Hyun-Gyu; Choi, Min-Kook; Lee, Sang-Chul

2011-03-01

Wireless capsule endoscopy (WCE) has been intensively researched recently due to its convenience for diagnosis and extended detection coverage of some diseases. Typically, a full recording covering entire human digestive system requires about 8 to 12 hours for a patient carrying a capsule endoscope and a portable image receiver/recorder unit, which produces 120,000 image frames on average. In spite of the benefits of close examination, WCE based test has a barrier for quick diagnosis such that a trained diagnostician must examine a huge amount of images for close investigation, normally over 2 hours. The main purpose of our work is to present a novel machine vision approach to reduce diagnosis time by automatically detecting duplicated recordings caused by backward camera movement, typically containing redundant information, in small intestine. The developed technique could be integrated with a visualization tool which supports intelligent inspection method, such as automatic play speed control. Our experimental result shows high accuracy of the technique by detecting 989 duplicate image frames out of 10,000, equivalently to 9.9% data reduction, in a WCE video from a real human subject. With some selected parameters, we achieved the correct detection ratio of 92.85% and the false detection ratio of 13.57%.

A Wireless Capsule Endoscope System With Low-Power Controlling and Processing ASIC.

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Xinkai Chen; Xiaoyu Zhang; Linwei Zhang; Xiaowen Li; Nan Qi; Hanjun Jiang; Zhihua Wang

2009-02-01

This paper presents the design of a wireless capsule endoscope system. The proposed system is mainly composed of a CMOS image sensor, a RF transceiver and a low-power controlling and processing application specific integrated circuit (ASIC). Several design challenges involving system power reduction, system miniaturization and wireless wake-up method are resolved by employing optimized system architecture, integration of an area and power efficient image compression module, a power management unit (PMU) and a novel wireless wake-up subsystem with zero standby current in the ASIC design. The ASIC has been fabricated in 0.18-mum CMOS technology with a die area of 3.4 mm * 3.3 mm. The digital baseband can work under a power supply down to 0.95 V with a power dissipation of 1.3 mW. The prototype capsule based on the ASIC and a data recorder has been developed. Test result shows that proposed system architecture with local image compression lead to an average of 45% energy reduction for transmitting an image frame.

Wireless powering for a self-propelled and steerable endoscopic capsule for stomach inspection.

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Carta, R; Tortora, G; Thoné, J; Lenaerts, B; Valdastri, P; Menciassi, A; Dario, P; Puers, R

2009-12-15

This paper describes the integration of an active locomotion module in a wirelessly powered endoscopic capsule. The device is a submersible capsule optimized to operate in a fluid environment in a liquid-distended stomach. A 3D inductive link is used to supply up to 400mW to the embedded electronics and a set of 4 radio-controlled motor propellers. The design takes advantage of a ferrite-core in the receiving coil-set. This approach significantly improves the coupling with the external field source with respect to earlier work by the group. It doubles the power that can be received with a coreless coil-set under identical external conditions. The upper limit of the received power was achieved complying with the strict regulations for safe exposure of biological tissue to variable magnetic fields. The wireless transferred power was proven to be sufficient to achieve the speed of 7cm/s in any directions. An optimized locomotion strategy was defined which limits the power consumption by running only 2 motors at a time. A user interface and a joystick controller allow to fully drive the capsule in an intuitive manner. The device functionalities were successfully tested in a dry and a wet environment in a laboratory set-up.

Classification of endoscopic capsule images by using color wavelet features, higher order statistics and radial basis functions.

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Lima, C S; Barbosa, D; Ramos, J; Tavares, A; Monteiro, L; Carvalho, L

2008-01-01

This paper presents a system to support medical diagnosis and detection of abnormal lesions by processing capsule endoscopic images. Endoscopic images possess rich information expressed by texture. Texture information can be efficiently extracted from medium scales of the wavelet transform. The set of features proposed in this paper to code textural information is named color wavelet covariance (CWC). CWC coefficients are based on the covariances of second order textural measures, an optimum subset of them is proposed. Third and forth order moments are added to cope with distributions that tend to become non-Gaussian, especially in some pathological cases. The proposed approach is supported by a classifier based on radial basis functions procedure for the characterization of the image regions along the video frames. The whole methodology has been applied on real data containing 6 full endoscopic exams and reached 95% specificity and 93% sensitivity.

An Automated Self-Learning Quantification System to Identify Visible Areas in Capsule Endoscopy Images.

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Hashimoto, Shinichi; Ogihara, Hiroyuki; Suenaga, Masato; Fujita, Yusuke; Terai, Shuji; Hamamoto, Yoshihiko; Sakaida, Isao

2017-08-01

Visibility in capsule endoscopic images is presently evaluated through intermittent analysis of frames selected by a physician. It is thus subjective and not quantitative. A method to automatically quantify the visibility on capsule endoscopic images has not been reported. Generally, when designing automated image recognition programs, physicians must provide a training image; this process is called supervised learning. We aimed to develop a novel automated self-learning quantification system to identify visible areas on capsule endoscopic images. The technique was developed using 200 capsule endoscopic images retrospectively selected from each of three patients. The rate of detection of visible areas on capsule endoscopic images between a supervised learning program, using training images labeled by a physician, and our novel automated self-learning program, using unlabeled training images without intervention by a physician, was compared. The rate of detection of visible areas was equivalent for the supervised learning program and for our automatic self-learning program. The visible areas automatically identified by self-learning program correlated to the areas identified by an experienced physician. We developed a novel self-learning automated program to identify visible areas in capsule endoscopic images.

Advances in pediatric gastroenterology: introducing video camera capsule endoscopy.

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Siaw, Emmanuel O

2006-04-01

The video camera capsule endoscope is a gastrointestinal endoscope approved by the U.S. Food and Drug Administration in 2001 for use in diagnosing gastrointestinal disorders in adults. In 2003, the agency approved the device for use in children ages 10 and older, and the endoscope is currently in use at Arkansas Children's Hospital. A capsule camera, lens, battery, transmitter and antenna together record images of the small intestine as the endoscope makes its way through the bowel. The instrument is used with minimal risk to the patient while offering a high degree of accuracy in diagnosing small intestine disorders.

A portable wireless power transmission system for video capsule endoscopes.

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Shi, Yu; Yan, Guozheng; Zhu, Bingquan; Liu, Gang

2015-01-01

Wireless power transmission (WPT) technology can solve the energy shortage problem of the video capsule endoscope (VCE) powered by button batteries, but the fixed platform limited its clinical application. This paper presents a portable WPT system for VCE. Besides portability, power transfer efficiency and stability are considered as the main indexes of optimization design of the system, which consists of the transmitting coil structure, portable control box, operating frequency, magnetic core and winding of receiving coil. Upon the above principles, the correlation parameters are measured, compared and chosen. Finally, through experiments on the platform, the methods are tested and evaluated. In the gastrointestinal tract of small pig, the VCE is supplied with sufficient energy by the WPT system, and the energy conversion efficiency is 2.8%. The video obtained is clear with a resolution of 320×240 and a frame rate of 30 frames per second. The experiments verify the feasibility of design scheme, and further improvement direction is discussed.

A wireless power transmission system for an active capsule endoscope for colon inspection.

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Jia, Zhiwei; Yan, Guozheng; Shi, Yu; Zhu, Bingquan

2012-07-01

Multipurpose active capsule endoscopes (ACE) have drawn considerable attention in recent years, but these devices continue to suffer from energy limitations. In order to deliver stable and sufficient energy safely, a wireless power transmission system based on inductive coupling is presented. The system consists of a double-layer solenoid pair primary coil outside and a multiple secondary coils inside the body. At least 500 mW usable power can be transmitted under the worst geometrical conditions and the safety restraints in a volume of Φ13 × 13 mm. The wireless power transmission system is integrated to an ACE and applied in animal experiments. The designed wireless power transmission is proved to be feasible and potentially safe in a future application.

Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2

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Lorenzini, Enrico C.; Gullahorn, Gordon E.; Cosmo, Mario L.; Estes, Robert D.; Grossi, Mario D.

1994-01-01

This final report covers nine years of research on future tether applications and on the actual flights of the Small Expendable Deployment System (SEDS). Topics covered include: (1) a description of numerical codes used to simulate the orbital and attitude dynamics of tethered systems during station keeping and deployment maneuvers; (2) a comparison of various tethered system simulators; (3) dynamics analysis, conceptual design, potential applications and propagation of disturbances and isolation from noise of a variable gravity/microgravity laboratory tethered to the Space Station; (4) stability of a tethered space centrifuge; (5) various proposed two-dimensional tethered structures for low Earth orbit for use as planar array antennas; (6) tethered high gain antennas; (7) numerical calculation of the electromagnetic wave field on the Earth's surface on an electrodynamically tethered satellite; (8) reentry of tethered capsules; (9) deployment dynamics of SEDS-1; (10) analysis of SEDS-1 flight data; and (11) dynamics and control of SEDS-2.

Magnetically-driven medical robots: An analytical magnetic model for endoscopic capsules design

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Li, Jing; Barjuei, Erfan Shojaei; Ciuti, Gastone; Hao, Yang; Zhang, Peisen; Menciassi, Arianna; Huang, Qiang; Dario, Paolo

2018-04-01

Magnetic-based approaches are highly promising to provide innovative solutions for the design of medical devices for diagnostic and therapeutic procedures, such as in the endoluminal districts. Due to the intrinsic magnetic properties (no current needed) and the high strength-to-size ratio compared with electromagnetic solutions, permanent magnets are usually embedded in medical devices. In this paper, a set of analytical formulas have been derived to model the magnetic forces and torques which are exerted by an arbitrary external magnetic field on a permanent magnetic source embedded in a medical robot. In particular, the authors modelled cylindrical permanent magnets as general solution often used and embedded in magnetically-driven medical devices. The analytical model can be applied to axially and diametrically magnetized, solid and annular cylindrical permanent magnets in the absence of the severe calculation complexity. Using a cylindrical permanent magnet as a selected solution, the model has been applied to a robotic endoscopic capsule as a pilot study in the design of magnetically-driven robots.

Medical capsule robots: A renaissance for diagnostics, drug delivery and surgical treatment.

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Mapara, Sanyat S; Patravale, Vandana B

2017-09-10

The advancements in electronics and the progress in nanotechnology have resulted in path breaking development that will transform the way diagnosis and treatment are carried out currently. This development is Medical Capsule Robots, which has emerged from the science fiction idea of robots travelling inside the body to diagnose and cure disorders. The first marketed capsule robot was a capsule endoscope developed to capture images of the gastrointestinal tract. Today, varieties of capsule endoscopes are available in the market. They are slightly larger than regular oral capsules, made up of a biocompatible case and have electronic circuitry and mechanisms to capture and transmit images. In addition, robots with diagnostic features such as in vivo body temperature detection and pH monitoring have also been launched in the market. However, a multi-functional unit that will diagnose and cure diseases inside the body has not yet been realized. A remote controlled capsule that will undertake drug delivery and surgical treatment has not been successfully launched in the market. High cost, inadequate power supply, lack of control over drug release, limited space for drug storage on the capsule, inadequate safety and no mechanisms for active locomotion and anchoring have prevented their entry in the market. The capsule robots can revolutionize the current way of diagnosis and treatment. This paper discusses in detail the applications of medical capsule robots in diagnostics, drug delivery and surgical treatment. In diagnostics, detailed analysis has been presented on wireless capsule endoscopes, issues associated with the marketed versions and their corresponding solutions in literature. Moreover, an assessment has been made of the existing state of remote controlled capsules for targeted drug delivery and surgical treatment and their future impact is predicted. Besides the need for multi-functional capsule robots and the areas for further research have also been

Magnetic air capsule robotic system: proof of concept of a novel approach for painless colonoscopy.

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Valdastri, P; Ciuti, G; Verbeni, A; Menciassi, A; Dario, P; Arezzo, A; Morino, M

2012-05-01

Despite being considered the most effective method for colorectal cancer diagnosis, colonoscopy take-up as a mass-screening procedure is limited mainly due to invasiveness, patient discomfort, fear of pain, and the need for sedation. In an effort to mitigate some of the disadvantages associated with colonoscopy, this work provides a preliminary assessment of a novel endoscopic device consisting in a softly tethered capsule for painless colonoscopy under robotic magnetic steering. The proposed platform consists of the endoscopic device, a robotic unit, and a control box. In contrast to the traditional insertion method (i.e., pushing from behind), a "front-wheel" propulsion approach is proposed. A compliant tether connecting the device to an external box is used to provide insufflation, passing a flexible operative tool, enabling lens cleaning, and operating the vision module. To assess the diagnostic and treatment ability of the platform, 12 users were asked to find and remove artificially implanted beads as polyp surrogates in an ex vivo model. In vivo testing consisted of a qualitative study of the platform in pigs, focusing on active locomotion, diagnostic and therapeutic capabilities, safety, and usability. The mean percentage of beads identified by each user during ex vivo trials was 85 ± 11%. All the identified beads were removed successfully using the polypectomy loop. The mean completion time for accomplishing the entire procedure was 678 ± 179 s. No immediate mucosal damage, acute complications such as perforation, or delayed adverse consequences were observed following application of the proposed method in vivo. Use of the proposed platform in ex vivo and preliminary animal studies indicates that it is safe and operates effectively in a manner similar to a standard colonoscope. These studies served to demonstrate the platform's added advantages of reduced size, front-wheel drive strategy, and robotic control over locomotion and orientation.

Performance evaluation of power transmission coils for powering endoscopic wireless capsules.

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Basar, Md Rubel; Ahmad, Mohd Yazed; Cho, Jongman; Ibrahim, Fatimah

2015-01-01

This paper presents an analysis of H-field generated by a simple solenoid, pair of solenoids, pair of double-layer solenoids, segmented-solenoid, and Helmholtz power transmission coils (PTCs) to power an endoscopic wireless capsule (WC). The H-fields were computed using finite element analysis based on partial differential equations. Three parameters were considered in the analysis: i) the maximum level of H-field (Hmax) to which the patient's body would be exposed, ii) the minimum level of H-field (Hmin) effective for power transmission, and iii) uniformity of H-field. We validated our analysis by comparing the computed data with data measured from a fabricated Helmholtz PTC. This analysis disclosed that at the same excitation power, all the PTCs are able to transfer same amount of minimum usable power since they generated almost equal value of Hmin. The level of electromagnetic exposure and power transfer stability across all the PTCs would vary significantly which is mainly due to the different level of Hmax and H-field uniformity. The segmented solenoid PTC would cause the lowest exposure and this PTC can transfer the maximum amount of power. The Helmholtz PTC would be able to transfer the most stable power with a moderate level of exposure.

Small-bowel capsule endoscopy in patients with suspected Crohn's disease-diagnostic value and complications.

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Figueiredo, Pedro; Almeida, Nuno; Lopes, Sandra; Duque, Gabriela; Freire, Paulo; Lérias, Clotilde; Gouveia, Hermano; Sofia, Carlos

2010-01-01

The aim of this work was to assess the value of capsule enteroscopy in the diagnosis of patients with suspected Crohn's Disease (CD). Methods. This was a retrospective study in a single tertiary care centre involving patients undergoing capsule enteroscopy for suspected CD. Patients taking nonsteroidal anti inflammatory drugs during the thirty preceding days or with a follow-up period of less than six months were excluded. Results. Seventy eight patients were included. The endoscopic findings included mucosal breaks in 50%, ulcerated stenosis in 5%, and villous atrophy in 4%. The diagnosis of CD was established in 31 patients. The sensitivity, specificity, positive and negative predictive value of the endoscopic findings were 93%, 80%, 77%, and 94%, respectively. Capsule retention occurred in four patients (5%). The presence of ulcerated stenosis was significantly more frequent in patients with positive inflammatory markers. The diagnostic yield of capsule enteroscopy in patients with negative ileoscopy was 56%, with a diagnostic acuity of 93%. Small bowel capsule endoscopy is a safe and valid technique for assessing patients with suspected CD. Capsule retention is more frequent in patients with positive inflammatory markers. Patients with negative ileoscopy and suspected CD should be submitted to capsule enteroscopy.

Small-Bowel Capsule Endoscopy in Patients with Suspected Crohn's Disease—Diagnostic Value and Complications

Science.gov (United States)

Figueiredo, Pedro; Almeida, Nuno; Lopes, Sandra; Duque, Gabriela; Freire, Paulo; Lérias, Clotilde; Gouveia, Hermano; Sofia, Carlos

2010-01-01

Background. The aim of this work was to assess the value of capsule enteroscopy in the diagnosis of patients with suspected Crohn's Disease (CD). Methods. This was a retrospective study in a single tertiary care centre involving patients undergoing capsule enteroscopy for suspected CD. Patients taking nonsteroidal anti inflammatory drugs during the thirty preceding days or with a follow-up period of less than six months were excluded. Results. Seventy eight patients were included. The endoscopic findings included mucosal breaks in 50%, ulcerated stenosis in 5%, and villous atrophy in 4%. The diagnosis of CD was established in 31 patients. The sensitivity, specificity, positive and negative predictive value of the endoscopic findings were 93%, 80%, 77%, and 94%, respectively. Capsule retention occurred in four patients (5%). The presence of ulcerated stenosis was significantly more frequent in patients with positive inflammatory markers. The diagnostic yield of capsule enteroscopy in patients with negative ileoscopy was 56%, with a diagnostic acuity of 93%. Conclusions. Small bowel capsule endoscopy is a safe and valid technique for assessing patients with suspected CD. Capsule retention is more frequent in patients with positive inflammatory markers. Patients with negative ileoscopy and suspected CD should be submitted to capsule enteroscopy. PMID:20811612

Small-Bowel Capsule Endoscopy in Patients with Suspected Crohn's Disease—Diagnostic Value and Complications

Directory of Open Access Journals (Sweden)

Pedro Figueiredo

2010-01-01

Full Text Available Background. The aim of this work was to assess the value of capsule enteroscopy in the diagnosis of patients with suspected Crohn's Disease (CD. Methods. This was a retrospective study in a single tertiary care centre involving patients undergoing capsule enteroscopy for suspected CD. Patients taking nonsteroidal anti inflammatory drugs during the thirty preceding days or with a follow-up period of less than six months were excluded. Results. Seventy eight patients were included. The endoscopic findings included mucosal breaks in 50%, ulcerated stenosis in 5%, and villous atrophy in 4%. The diagnosis of CD was established in 31 patients. The sensitivity, specificity, positive and negative predictive value of the endoscopic findings were 93%, 80%, 77%, and 94%, respectively. Capsule retention occurred in four patients (5%. The presence of ulcerated stenosis was significantly more frequent in patients with positive inflammatory markers. The diagnostic yield of capsule enteroscopy in patients with negative ileoscopy was 56%, with a diagnostic acuity of 93%. Conclusions. Small bowel capsule endoscopy is a safe and valid technique for assessing patients with suspected CD. Capsule retention is more frequent in patients with positive inflammatory markers. Patients with negative ileoscopy and suspected CD should be submitted to capsule enteroscopy.

Capsule-odometer: a concept to improve accurate lesion localisation.

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Karargyris, Alexandros; Koulaouzidis, Anastasios

2013-09-21

In order to improve lesion localisation in small-bowel capsule endoscopy, a modified capsule design has been proposed incorporating localisation and - in theory - stabilization capabilities. The proposed design consists of a capsule fitted with protruding wheels attached to a spring-mechanism. This would act as a miniature odometer, leading to more accurate lesion localization information in relation to the onset of the investigation (spring expansion e.g., pyloric opening). Furthermore, this capsule could allow stabilization of the recorded video as any erratic, non-forward movement through the gut is minimised. Three-dimensional (3-D) printing technology was used to build a capsule prototype. Thereafter, miniature wheels were also 3-D printed and mounted on a spring which was attached to conventional capsule endoscopes for the purpose of this proof-of-concept experiment. In vitro and ex vivo experiments with porcine small-bowel are presented herein. Further experiments have been scheduled.

Study of a wireless power transmission system for an active capsule endoscope.

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Xin, Wenhui; Yan, Guozheng; Wang, Wenxin

2010-03-01

An active capsule endoscope (ACE) will consume much more energy than can be power by batteries. Its orientation and position are always undetermined when it continues the natural way down the gastrointestinal track. In order to deliver stable and sufficient energy to ACE safely, a wireless power transmission system based on inductive coupling is presented. The system consists of a Helmholtz primary coil outside and a multiple secondary coils inside the body. The Helmholtz primary coil is driven to generate a uniform alternating magnetic field covering the whole of the alimentary tract, and the multiple secondary coils receive energy regardless of the ACE's position and orientation relative to the generated magnetic field. The human tissue safety of the electromagnetic field generated by transmitting coil was evaluated, based on a high-resolution realistic human model. At least 310 mW usable power can be transmitted under the worst geometrical conditions. Outer dimensions of the power receiver, 10 mm diameter x 12 mm; transmitting power, 25 W; resonant frequency, 400 kHz. The maximum specific absorption rate (SAR) and current density of human tissues are 0.329 W/kg and 3.82 A/m(2), respectively, under the basic restrictions of the International Commission on Non-ionizing Radiation Protection (ICNIRP). The designed wireless power transmission is shown to be feasible and potentially safe in a future application. (c) 2010 John Wiley & Sons, Ltd.

Tether dynamics and control results for tethered satellite system's initial flight

Science.gov (United States)

Chapel, Jim D.; Flanders, Howard

The recent Tethered Satellite System-1 (TSS-1) mission has provided a wealth of data concerning the dynamics of tethered systems in space and has demonstrated the effectiveness of operational techniques designed to control these dynamics. In this paper, we review control techniques developed for managing tether dynamics, and discuss the results of using these techniques for the Tethered Satellite System's maiden flight on STS-46. In particular, the flight results of controlling libration dynamics, string dynamics, and slack tether are presented. These results show that tether dynamics can be safely managed. The overall stability of the system was found to be surprisingly good even at relatively short tether lengths. In fact, the system operated in passive mode at a tether length of 256 meters for over 9 hours. Only monitoring of the system was required during this time. Although flight anomalies prevented the planned deployment to 20 km, the extended operations at shorter tether lengths have proven the viability of using tethers in space. These results should prove invaluable in preparing for future missions with tethered objects in space.

Wireless capsule endoscopy of the small bowel: development, testing, and first human trials

Science.gov (United States)

Swain, Paul; Iddan, Gavriel J.; Meron, Gavriel; Glukhovsky, Arkady

2001-01-01

Small bowel endoscopy with existing endoscopes is limited by problems of discomfort and the technical difficulty of advancing far into the small-bowel. Our aim has been to develop and test wireless capsule endoscopy. Wireless endoscopes, in the form of capsules (11 x 33 mm), were constructed by Given Imaging. These were powered by silver oxide batteries and each contained a CMOS imaging chip and miniature processor, white light emitting diodes (LEDs), a short focal length lens, and a miniature transmitter and antenna. Two video frames per second were transmitted, using radio-frequency (approx. 410 MHz), to an array of aerials attached to the body. The array of aerials can also be used to calculate the position of the capsule in the body. The images were stored on a portable recorder carried on a belt and subsequently downloaded for analysis. The batteries allow more than 5 hours of recording, although the capsule generally passes through the whole small bowel in under two hours. Clear video images of the human bowel were recorded from the pylorus to the caecum. Wireless endoscopy, for the first time, allows painless optical imaging of the whole of the small bowel.

Safety and Feasibility of Using the Second-Generation Pillcam Colon Capsule to Assess Active Colonic Crohn's Disease

NARCIS (Netherlands)

D'Haens, Geert; Löwenberg, Mark; Samaan, Mark A.; Franchimont, Denis; Ponsioen, Cyriel; van den Brink, Gijs R.; Fockens, Paul; Bossuyt, Peter; Amininejad, Leila; Rajamannar, Gopalan; Lensink, Elsemieke M.; van Gossum, Andre M.

2015-01-01

The second-generation Pillcam Colon Capsule Endoscope (PCCE-2; Given Imaging Ltd, Yoqneam, Israel) is an ingestible capsule for visualization of the colon. We performed a multicenter pilot study to assess its safety and feasibility in evaluating the severity of Crohn's disease (CD). In a prospective

Video capsule endoscopy after bariatric and gastric surgery: oral ingestion is associated with satisfactory completion rate.

Science.gov (United States)

Stanich, Peter P; Kleinman, Bryan; Porter, Kyle M; Meyer, Marty M

2015-01-01

To investigate the outcomes of video capsule endoscopy (VCE) performed on patients after bariatric and gastric surgery with a focus on delivery method (oral ingestion or endoscopic placement). There is minimal published data regarding the use of VCE in patients after bariatric and gastric surgery and the optimal delivery method is unknown. Retrospective case series of patients with bariatric or gastric surgery undergoing VCE in a tertiary care center over 3 years. Outcomes of interest were completion of the procedure and bowel transit times. Twenty-three patients met study criteria. They underwent 24 VCE in the study period, with 13/16 (81.3%; 95% CI, 54%-96%) completed to the colon after oral ingestion and 5/8 (62.5%; 95% CI, 24%-91%) completed after endoscopic deployment. The median gastric transit time after oral ingestion was 440) (P=0.48). There were no instances of capsule retention. Oral ingestion of VCE resulted in a satisfactory completion rate with rapid gastric transit after bariatric and gastric surgery. There were no capsule retention events. Given this and the favorable risk and cost profile, oral ingestion should be favored over endoscopic placement in this patient population.

Wireless powered capsule endoscopy for colon diagnosis and treatment

International Nuclear Information System (INIS)

Chen, Wenwen; Yan, Guozheng; He, Shu; Ke, Quan; Wang, Zhiwu; Liu, Hua; Jiang, Pingping

2013-01-01

This paper presents a wireless power transfer system integrated with an active locomotion and biopsy module in an endoscopic capsule for colon inspection. The capsule, which can move automatically, is designed for non-invasive biopsy and visual inspection of the intestine. To supply enough power for multiple functions and ensure safety for the human body, the efficiency of the current power transmission system needs to be improved. To take full advantage of the volume in the capsule body, a novel structure of receiving coils wound on a multi-core of MnZn ferrite hollow cylinder was used; with this new core, the efficiency increased to more than 7.98%. Up to 1.4 W of dc power can be delivered to the capsule as it travels along the gastrointestinal tract. Three micro motors were integrated for pumping, anchoring, locomotion and biopsy. A user interface and RF communication enables the operator to drive the capsule in an intuitive manner. To gauge the efficacy of the wireless power supply in a simulated real-world application, the biopsy and locomotion capabilities of the device were successfully tested in a slippery, soft tube and gut environment in vitro. (paper)

Swallowable Wireless Capsule Endoscopy: Progress and Technical Challenges

Directory of Open Access Journals (Sweden)

Guobing Pan

2012-01-01

Full Text Available Wireless capsule endoscopy (WCE offers a feasible noninvasive way to detect the whole gastrointestinal (GI tract and revolutionizes the diagnosis technology. However, compared with wired endoscopies, the limited working time, the low frame rate, and the low image resolution limit the wider application. The progress of this new technology is reviewed in this paper, and the evolution tendencies are analyzed to be high image resolution, high frame rate, and long working time. Unfortunately, the power supply of capsule endoscope (CE is the bottleneck. Wireless power transmission (WPT is the promising solution to this problem, but is also the technical challenge. Active CE is another tendency and will be the next geneion of the WCE. Nevertheless, it will not come true shortly, unless the practical locomotion mechanism of the active CE in GI tract is achieved. The locomotion mechanism is the other technical challenge, besides the challenge of WPT. The progress about the WPT and the active capsule technology is reviewed.

Technology Insight: current status of video capsule endoscopy.

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Cave, David R

2006-03-01

Video capsule endoscopy (VCE) is the most recent major practical and conceptual development in the field of endoscopy. The video capsule endoscope-a small, pill-sized, passive imaging device-has been demonstrated to be the pre-eminent imaging device for disorders of the small intestine. The initial use for VCE was to detect the origin of obscure gastrointestinal bleeding. Several other indications have now been justified, or are in the process of evaluation. More than 200,000 of these disposable devices have been used worldwide, with an extraordinarily good safety record: indeed, the device has been approved for use in children as young as 10 years of age. In addition, a double-ended capsule has now been approved for the evaluation of mucosal disease in the esophagus. The now-widespread deployment of the device into gastrointestinal practice in the US and many other countries suggests that VCE has achieved mainstream utility. The development of similar competitor devices, and devices whose movement can be controlled, is in progress.

Expanded Endoscopic Endonasal Resection of Retrochiasmatic Craniopharyngioma.

Science.gov (United States)

Davanzo, Justin R; Goyal, Neerav; Zacharia, Brad E

2018-02-01

This video abstract demonstrates the use of the expanded endoscopic endonasal approach for the resection of a retrochiasmatic craniopharyngioma. These tumors are notoriously difficult to treat, and many approaches have been tried to facilitate safe and effective resection. The endoscopic endonasal approach has been increasingly utilized for selected sellar/suprasellar pathology. We present the case of a 39-year-old man who was found to have a cystic, partially calcified suprasellar mass consistent with a craniopharyngioma. To facilitate robust skull base repair, a vascularized nasoseptal flap was harvested. A wide sphenoidotomy was performed and the sella and tuberculum were exposed. After the dural opening and arachnoid dissection, the stalk was identified, merging seamlessly with the tumor capsule. The lesion was then internally debulked with the use of an ultrasonic aspirator. The capsule was then dissected off of the optic chiasm, thalamus, and hypothalamus. The cavity was inspected with an angled endoscope to ensure complete resection. A multilayered reconstruction was performed using autologous fascia lata, the previously harvested nasoseptal flap, and dural sealant. Postoperatively, the patient did have expected panhypopituitarism but remained neurologically intact and had improvement in his vision. In conclusion, this video demonstrates how an expanded endonasal approach can be used to safely resect a craniopharyngioma, even when in close proximity to delicate structures such as the optic chiasm. The link to the video can be found at: https://youtu.be/tahjHmrXhc4 .

Wireless power and data transmission strategies for next-generation capsule endoscopes

International Nuclear Information System (INIS)

Puers, R; Carta, R; Thoné, J

2011-01-01

Capsular endoscopy is becoming increasingly popular as an alternative to traditional gastro-intestinal (GI) examination techniques. However, the breakthrough of these devices is hindered by the limited amount of power that can be stored in a tiny pill. Most commercial devices use two watch batteries that can only provide an average power of 25 mW for about 6 h, certainly not sufficient for advanced robotic features. A dedicated inductive powering system, operating at 1 MHz to limit the human body absorption, has been developed which was proven to support the transfer of over 300 mW. The system relies on a condensed set of orthogonal ferrite coils, embedded in the capsule, and an external unit based on a Helmholtz coil driven by a class E amplifier. Control data can be sent through the inductive link by modulating the power carrier, whereas a dedicated high data rate RF link is used to transfer the images from the capsule to the base station. Besides evaluating the compatibility with radio transmission, several demonstrators were assembled combining the wireless powering system with various locomotion strategies and LED illumination. This paper describes the design and implementation of the inductive powering system, its combination with data transmission techniques and the testing activity with other capsule-dedicated modules

Capsule enteroscopy and radiology of the small intestine

Energy Technology Data Exchange (ETDEWEB)

Fork, Frans-Thomas [Malmoe University Hospital, Department of Diagnostic Radiology, Malmoe (Sweden); Aabakken, Lars [Rikshospitalet University Hospital, Department of Gastroenterology, Oslo (Norway)

2007-12-15

In a very few years, the video capsule for small bowel enteroscopy has gained widespread clinical acceptance. It is readily ingested, disposable, and allows for a complete, low-invasive endoscopic examination of the entire mucosa of the small bowel. It is a patient-friendly method and a first-line procedure in the difficult evaluation of obscure gastrointestinal bleeding. It has the highest proven figure of diagnostic sensitivity for detecting lesions of the mucosa, irrespective of aetiology. The limitations of capsule endoscopy include difficulty in localising mucosal lesions anatomically and its restricted use in patients with dysphagia, strictures or motor dysfunction. Strictures, transmural and extra-mural lesions in patients with small bowel Crohn's disease are evaluated by MRI- enterography and CT-enterography. (orig.)

Capsule enteroscopy and radiology of the small intestine

International Nuclear Information System (INIS)

Fork, Frans-Thomas; Aabakken, Lars

2007-01-01

In a very few years, the video capsule for small bowel enteroscopy has gained widespread clinical acceptance. It is readily ingested, disposable, and allows for a complete, low-invasive endoscopic examination of the entire mucosa of the small bowel. It is a patient-friendly method and a first-line procedure in the difficult evaluation of obscure gastrointestinal bleeding. It has the highest proven figure of diagnostic sensitivity for detecting lesions of the mucosa, irrespective of aetiology. The limitations of capsule endoscopy include difficulty in localising mucosal lesions anatomically and its restricted use in patients with dysphagia, strictures or motor dysfunction. Strictures, transmural and extra-mural lesions in patients with small bowel Crohn's disease are evaluated by MRI- enterography and CT-enterography. (orig.)

NASPGHAN Capsule Endoscopy Clinical Report.

Science.gov (United States)

Friedlander, Joel A; Liu, Quin Y; Sahn, Benjamin; Kooros, Koorosh; Walsh, Catharine M; Kramer, Robert E; Lightdale, Jenifer R; Khlevner, Julie; McOmber, Mark; Kurowski, Jacob; Giefer, Matthew J; Pall, Harpreet; Troendle, David M; Utterson, Elizabeth C; Brill, Herbert; Zacur, George M; Lirio, Richard A; Lerner, Diana G; Reynolds, Carrie; Gibbons, Troy E; Wilsey, Michael; Liacouras, Chris A; Fishman, Douglas S

2017-03-01

Wireless capsule endoscopy (CE) was introduced in 2000 as a less invasive method to visualize the distal small bowel in adults. Because this technology has advanced it has been adapted for use in pediatric gastroenterology. Several studies have described its clinical use, utility, and various training methods but pediatric literature regarding CE is limited. This clinical report developed by the Endoscopic and Procedures Committee of the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition outlines the current literature, and describes the recommended current role, use, training, and future areas of research for CE in pediatrics.

Tethers in Space

Science.gov (United States)

Johnson, Les; Bilén, Sven G.; Gilchrist, Brian E.; Krause, Linda Habash

2017-09-01

This Special Section of Acta Astronautica contains several peer-reviewed papers selected from among those presented at the Fifth International Conference on Tethers in Space (TiS2016). After a hiatus of 21 years since the last Conference on Tethers in Space, TiS2016 brought together experts, practitioners, and other interested in space tethers and related fields. TiS2016 was held May 24-26, 2016 at The University of Michigan in Ann Arbor, Michigan, U.S.A. Leveraging the hard work of a great many volunteers, the conference co-chairs Prof. Brian Gilchrist and Prof. Sven Bilén welcomed an international contingent with authors from the U.S., Canada, Japan, Spain, China, Finland, Estonia, and Italy. The community provided updates on what has transpired since their last gathering by providing lessons learned; describing new technologies and subsystems; and proposing new tether missions and applications. Papers overviewed de-orbit systems, power generation, orbital maneuvering, momentum capture, debris removal, space tugs, space elevators, collision avoidance, and tether dynamics, among others.

Swallowing Tablets and Capsules Increases the Risk of Penetration and Aspiration in Patients with Stroke-Induced Dysphagia.

Science.gov (United States)

Schiele, Julia T; Penner, Heike; Schneider, Hendrik; Quinzler, Renate; Reich, Gabriele; Wezler, Nikolai; Micol, William; Oster, Peter; Haefeli, Walter E

2015-10-01

We evaluated the prevalence of difficulties swallowing solid dosage forms in patients with stroke-induced dysphagia and whether swallowing tablets/capsules increases their risk of penetration and aspiration. Concurrently, we explored whether routinely performed assessment tests help identify patients at risk. Using video endoscopy, we evaluated how 52 patients swallowed four different placebos (round, oval, and oblong tablets and a capsule) with texture-modified water (TMW, pudding consistency) and milk and rated their swallowing performance according to the Penetration Aspiration Scale (PAS). Additionally, Daniels Test, Bogenhausener Dysphagiescore, Scandinavian Stroke Scale, Barthel Index, and Tinetti's Mobility Test were conducted. A substantial proportion of the patients experienced severe difficulties swallowing solid oral dosage forms (TMW: 40.4 %, milk: 43.5 %). Compared to the administration of TMW/milk alone, the placebos increased the PAS values in the majority of the patients (TMW: median PAS from 1.5 to 2.0; milk: median PAS from 1.5 to 2.5, each p value <0.0001) and residue values were significantly higher (p < 0.05). Whereas video-endoscopic examination reliably identified patients with difficulties swallowing medication, neither patients' self-evaluation nor one of the routinely performed bedside tests did. Therefore, before video-endoscopic evaluation, many drugs were modified unnecessarily and 20.8 % of these were crushed inadequately, although switching to another dosage form or drug would have been possible. Hence, safety and effectiveness of swallowing tablets and capsules should be evaluated routinely in video-endoscopic examinations, tablets/capsules should rather be provided with TMW than with milk, and the appropriateness of "non per os except medication" orders for dysphagic stroke patients should be questioned.

Why Not Space Tethers?

Science.gov (United States)

Stone, Noble H.

2007-01-01

The Tethered Satellite System Space Shuttle missions, TSS-1 in 1993 and TSS-1R in 1996, were the height of space tether technology development. Since NASA's investment of some $200M and two Shuttle missions in those two pioneering missions, there have been several smaller tether flight experiments, but interest in this promising technology has waned within NASA as well as the DOD agencies. This is curious in view of the unique capabilities of space tether systems and the fact that they have been flight validated and shown to perform as, or better than, expected in earth orbit. While it is true that the TSS-1, TSS-1R and SEDS-2 missions experienced technical difficulties, the causes of these early developmental problems are now known to be design or materials flaws that are (1) unrelated to the basic viability of space tether technology, and (2) they are readily corrected. The purpose of this paper is to review the dynamic and electrodynamic fundamentals of space tethers and the unique capabilities they afford (that are enabling to certain types of space missions); to elucidate the nature, cause, and solution of the early developmental problems; and to provide an update on progress made in development of the technology. Finally, it is shown that (1) all problems experienced during early development of the technology now have solutions; and (2) the technology has been matured by advances made in strength and robustness of tether materials, high voltage engineering in the space environment, tether health and status monitoring, and the elimination of the broken tether hazard. In view of this, it is inexplicable why this flight-validated technology has not been utilized in the past decade, considering the powerful and unique capabilities that space tethers can afford that are, not only required to carryout, otherwise, unobtainable missions, but can also greatly reduce the cost of certain on-going space operations.

3D magnetic-resonance-coupling (MRC) localization of wireless capsule endoscopy

DEFF Research Database (Denmark)

Xia, Yongming; Zhang, Lihui; Lu, Kaiyuan

2016-01-01

) technique, which has been widely developed for efficient wireless power transfer, is introduced. It is proposed that the distance dependent signal strength in a MRC system can be beneficially used for 3D localization. The new 3D-MRC localization system consists of three orthogonal emitting coils which......Wireless Capsule Endoscope (WCE) enables developing actively controlled capsule for potential complex surgeries, imaging, and new medicine tests. These tasks of WCE need safe, efficient, and precise 3D localization techniques. In this paper, a new application of the magnetic resonance coupling (MRC...... are powered by a battery in the capsule, and three pairs of orthogonal receiving coils which are placed outside human body. The distances between the WCE and the receiving coils can be estimated with good accuracy by studying the signal strengths in individual receiving coils. The proposed new 3D...

Capsule enteroscopy and radiology of the small intestine.

OpenAIRE

Fork, Thomas; Aabakken, Lars

2007-01-01

In a very few years, the video capsule for small bowel enteroscopy has gained widespread clinical acceptance. It is readily ingested, disposable, and allows for a complete, low-invasive endoscopic examination of the entire mucosa of the small bowel. It is a patient-friendly method and a first-line procedure in the difficult evaluation of obscure gastrointestinal bleeding. It has the highest proven figure of diagnostic sensitivity for detecting lesions of the mucosa, irrespective of aetiology....

Pneumoperitoneum after Endoscopic Retrograde Cholangiopancreatography due to Rupture of Intrahepatic Bile Ducts and Glisson’s Capsule in Hepatic Metastasis: A Case Report and Review of Literature

Directory of Open Access Journals (Sweden)

Zubair Khan

2017-10-01

Full Text Available Introduction: Endoscopic retrograde cholangiopancreatography (ERCP has been proven to be a safe and effective method for diagnosis and treatment of biliary and pancreatic disorders. Major complications of ERCP include pancreatitis, hemorrhage, cholangitis, and duodenal perforation. We report a third case in literature of pneumoperitoneum after ERCP due to rupture of intrahepatic bile ducts and Glisson’s capsule in a peripheral hepatic lesion. Case Report: A 50-year-old male with a history of metastatic pancreatic neuroendocrine tumor and who had a partially covered metallic stent placed in the biliary tree 1 year ago presented to the oncology clinic with fatigue, abdominal pain, and hypotension. He was planned for ERCP for possible cholangitis secondary to obstructed previously placed biliary stent. However, the duodenoscope could not be advanced to the level of the major papilla because of narrowed pylorus and severely strictured duodenal sweep. Forward-view gastroscope was then passed with careful manipulation to the severely narrowed second part of the duodenum where the previously placed metallic stent was visualized. Balloon sweeping of stenting was done. Cholangiography did not show any leak. Following the procedure, the patient underwent CT scan of the abdomen that showed pneumoperitoneum which was communicating with pneumobilia through a loculated air collection in necrotic hepatic metastasis perforating Glisson’s capsule. The patient was managed conservatively. Conclusion: In our case, pneumoperitoneum resulted from rupture of intrahepatic bile ducts and Glisson’s capsule in hepatic metastasis. This case emphasizes the need for close clinical and radiological observation of patients with hepatic masses (primary or metastatic subjected to ERCP.

Tethering sockets and wrenches

Science.gov (United States)

Johnson, E. P.

1990-01-01

The tethering of sockets and wrenches was accomplished to improve the safety of working over motor segments. To accomplish the tethering of the sockets to the ratchets, a special design was implemented in which a groove was machined into each socket. Each socket was then fitted with a snap ring that can spin around the machined groove. The snap ring is tethered to the handle of the ratchet. All open end wrenches are also tethered to the ratchet or to the operator, depending upon the type. Tests were run to ensure that the modified tools meet torque requirements. The design was subsequently approved by Space Safety.

Tethering sockets and wrenches

Science.gov (United States)

Johnson, E. P.

1990-07-01

The tethering of sockets and wrenches was accomplished to improve the safety of working over motor segments. To accomplish the tethering of the sockets to the ratchets, a special design was implemented in which a groove was machined into each socket. Each socket was then fitted with a snap ring that can spin around the machined groove. The snap ring is tethered to the handle of the ratchet. All open end wrenches are also tethered to the ratchet or to the operator, depending upon the type. Tests were run to ensure that the modified tools meet torque requirements. The design was subsequently approved by Space Safety.

Experiments and Numerical Simulations of Electrodynamic Tether

Science.gov (United States)

Iki, Kentaro; Kawamoto, Satomi; Takahashi, Ayaka; Ishimoto, Tomori; Yanagida, Atsushi; Toda, Susumu

As an effective means of suppressing space debris growth, the Aerospace Research and Development Directorate of the Japan Aerospace Exploration Agency (JAXA) has been investigating an active space debris removal system that employs highly efficient electrodynamic tether (EDT) technology for orbital transfer. This study investigates tether deployment dynamics by means of on-ground experiments and numerical simulations of an electrodynamic tether system. Some key parameters used in the numerical simulations, such as the elastic modulus and damping ratio of the tether, the spring constant of the coiling of the tether, and deployment friction, must be estimated, and various experiments are conducted to determine these values. As a result, the following values were obtained: The elastic modulus of the tether was 40 GPa, and the damping ratio of the tether was 0.02. The spring constant and the damping ratio of the tether coiling were 10-4 N/m and 0.025 respectively. The deployment friction was 0.038ν + 0.005 N. In numerical simulations using a multiple mass tether model, tethers with lengths of several kilometers are deployed and the attitude dynamics of satellites attached to the end of the tether and tether libration are calculated. As a result, the simulations confirmed successful deployment of the tether with a length of 500 m using the electrodynamic tether system.

Energy transmission transformer for a wireless capsule endoscope: analysis of specific absorption rate and current density in biological tissue.

Science.gov (United States)

Shiba, Kenji; Nagato, Tomohiro; Tsuji, Toshio; Koshiji, Kohji

2008-07-01

This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype energy transmission system for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, backbone, and blood. First, electric and magnetic strength in the same conditions as the analytical model were measured and compared to the analytical values to confirm the validity of the analysis. Then, SAR and current density as a function of frequency and output power were analyzed. The validity of the analysis was confirmed by comparing the analytical values with the measured ones. The SAR was below the basic restrictions of the International Commission on Nonionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit energy safely up to 160 mW. In addition, we confirmed that the current density has decreased by reducing the primary coil's current.

Tethered Satellite System Contingency Investigation Board

Science.gov (United States)

1992-11-01

The Tethered Satellite System (TSS-1) was launched aboard the Space Shuttle Atlantis (STS-46) on July 31, 1992. During the attempted on-orbit operations, the Tethered Satellite System failed to deploy successfully beyond 256 meters. The satellite was retrieved successfully and was returned on August 6, 1992. The National Aeronautics and Space Administration (NASA) Associate Administrator for Space Flight formed the Tethered Satellite System (TSS-1) Contingency Investigation Board on August 12, 1992. The TSS-1 Contingency Investigation Board was asked to review the anomalies which occurred, to determine the probable cause, and to recommend corrective measures to prevent recurrence. The board was supported by the TSS Systems Working group as identified in MSFC-TSS-11-90, 'Tethered Satellite System (TSS) Contingency Plan'. The board identified five anomalies for investigation: initial failure to retract the U2 umbilical; initial failure to flyaway; unplanned tether deployment stop at 179 meters; unplanned tether deployment stop at 256 meters; and failure to move tether in either direction at 224 meters. Initial observations of the returned flight hardware revealed evidence of mechanical interference by a bolt with the level wind mechanism travel as well as a helical shaped wrap of tether which indicated that the tether had been unwound from the reel beyond the travel by the level wind mechanism. Examination of the detailed mission events from flight data and mission logs related to the initial failure to flyaway and the failure to move in either direction at 224 meters, together with known preflight concerns regarding slack tether, focused the assessment of these anomalies on the upper tether control mechanism. After the second meeting, the board requested the working group to complete and validate a detailed integrated mission sequence to focus the fault tree analysis on a stuck U2 umbilical, level wind mechanical interference, and slack tether in upper tether

Space Station tethered elevator system

Science.gov (United States)

Haddock, Michael H.; Anderson, Loren A.; Hosterman, K.; Decresie, E.; Miranda, P.; Hamilton, R.

1989-01-01

The optimized conceptual engineering design of a space station tethered elevator is presented. The tethered elevator is an unmanned, mobile structure which operates on a ten-kilometer tether spanning the distance between Space Station Freedom and a platform. Its capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The report discusses the potential uses, parameters, and evolution of the spacecraft design. Emphasis is placed on the elevator's structural configuration and three major subsystem designs. First, the design of elevator robotics used to aid in elevator operations and tethered experimentation is presented. Second, the design of drive mechanisms used to propel the vehicle is discussed. Third, the design of an onboard self-sufficient power generation and transmission system is addressed.

Capsule endoscopy in the diagnosis of Crohn’s disease

Directory of Open Access Journals (Sweden)

Niv Y

2013-05-01

Full Text Available Yaron NivDepartment of Gastroenterology, Rabin Medical Center, Tel Aviv University, Petah Tikva, IsraelAbstract: Crohn’s disease is a chronic inflammatory disorder affecting any part of the gastrointestinal tract, but frequently involves the small and large bowel. Typical presenting symptoms include abdominal pain and diarrhea. Patients with this disorder may also have extraintestinal manifestations, including arthritis, uveitis, and skin lesions. The PillCam™SB capsule is an ingestible disposable video camera that transmits high quality images of the small intestinal mucosa. This enables the small intestine to be readily accessible to physicians investigating for the presence of small bowel disorders, such as Crohn’s disease. Four meta-analyses have demonstrated that capsule endoscopy identifies Crohn’s disease when other methods are not helpful. It should be noted that it is the best noninvasive procedure for assessing mucosal status, but is not superior to ileocolonoscopy, which remains the gold standard for assessment of ileocolonic disease. Mucosal healing along the small bowel can only be demonstrated by an endoscopic procedure such as capsule endoscopy. Achievement of long-term mucosal healing has been associated with a trend towards a decreased need for hospitalization and a decreased requirement for corticosteroid treatment in patients with Crohn’s disease. Recently, we have developed and validated the Capsule Endoscopy Crohn’s Disease Activity Index (also known as the Niv score for Crohn’s disease of the small bowel. The next step is to expand our score to the colon, and to determine the role and benefit of a capsule endoscopy activity score in patients suffering from Crohn’s ileocolitis and/or colitis. This scoring system will also serve to improve our understanding of the impact of capsule endoscopy, and therefore treatment, on the immediate outcome of this disorder. As the best procedure available for assessing

Coat/Tether Interactions—Exception or Rule?

Science.gov (United States)

Schröter, Saskia; Beckmann, Sabrina; Schmitt, Hans Dieter

2016-01-01

Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers. PMID:27243008

Coat/Tether Interactions-Exception or Rule?

Science.gov (United States)

Schroeter, Saskia; Beckmann, Sabrina; Schmitt, Hans Dieter

2016-01-01

Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers.

Two Tethered Balloon Systems

Science.gov (United States)

Youngbluth, Otto; Owens, Thomas L.; Storey, Richard W.

1990-01-01

Systems take meteorological measurements for variety of research projects. Report describes work done by NASA Langley Research Center in atmospheric research using tethered balloon systems composed of commercially available equipment. Two separate tethered balloon systems described in report have payloads and configurations tailored to requirements of specific projects. Each system capable of measuring atmospheric parameter or species in situ and then telemetering this data in real time to ground station. Meteorological data and concentration of ozone typically measured. Indicates instrumented tethered balloon systems have distinct advantages over other systems for gathering data on troposphere.

Development and Testing of a Magnetically Actuated Capsule Endoscopy for Obesity Treatment.

Directory of Open Access Journals (Sweden)

Thanh Nho Do

Full Text Available Intra-gastric balloons (IGB have become an efficient and less invasive method for obesity treatment. The use of traditional IGBs require complex insertion tools and flexible endoscopes to place and remove the balloon inside the patient's stomach, which may cause discomfort and complications to the patient. This paper introduces a new ingestible weight-loss capsule with a magnetically remote-controlled inflatable and deflatable balloon. To inflate the balloon, biocompatible effervescent chemicals are used. As the source of the actuation is provided via external magnetic fields, the magnetic capsule size can be significantly reduced compared to current weight-loss capsules in the literature. In addition, there are no limitations on the power supply. To lose weight, the obese subject needs only to swallow the magnetic capsule with a glass of water. Once the magnetic capsule has reached the patient's stomach, the balloon will be wirelessly inflated to occupy gastric space and give the feeling of satiety. The balloon can be wirelessly deflated at any time to allow the magnetic capsule to travel down the intestine and exit the body via normal peristalsis. The optimal ratio between the acid and base to provide the desired gas volume is experimentally evaluated and presented. A prototype capsule (9.6mm x 27mm is developed and experimentally validated in ex-vivo experiments. The unique ease of delivery and expulsion of the proposed magnetic capsule is slated to make this development a good treatment option for people seeking to lose excess weight.

Space tether dynamics: an introduction

Science.gov (United States)

Denny, Mark

2018-05-01

The dynamics of orbiting tethers (space elevators and skyhooks) is developed from an unusual direction: Lagrangian rather than Newtonian mechanics. These basic results are derived among others: space elevator required length with and without counterweight, location and magnitude of maximum tether tension, skyhook orbital parameters and tether tension. These conceptual devices are being increasingly discussed as technologically feasible; here they make an interesting pedagogical application of Lagrangian mechanics suitable for undergraduate physics students.

The space station tethered elevator system

Science.gov (United States)

Anderson, Loren A.

1989-01-01

The optimized conceptual engineering design of a space station tethered elevator is presented. The elevator is an unmanned mobile structure which operates on a ten kilometer tether spanning the distance between the Space Station and a tethered platform. Elevator capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The potential uses, parameters, and evolution of the spacecraft design are discussed. Engineering development of the tethered elevator is the result of work conducted in the following areas: structural configurations; robotics, drive mechanisms; and power generation and transmission systems. The structural configuration of the elevator is presented. The structure supports, houses, and protects all systems on board the elevator. The implementation of robotics on board the elevator is discussed. Elevator robotics allow for the deployment, retrieval, and manipulation of tethered objects. Robotic manipulators also aid in hooking the elevator on a tether. Critical to the operation of the tethered elevator is the design of its drive mechanisms, which are discussed. Two drivers, located internal to the elevator, propel the vehicle along a tether. These modular components consist of endless toothed belts, shunt-wound motors, regenerative power braking, and computer controlled linear actuators. The designs of self-sufficient power generation and transmission systems are reviewed. Thorough research indicates all components of the elevator will operate under power provided by fuel cells. The fuel cell systems will power the vehicle at seven kilowatts continuously and twelve kilowatts maximally. A set of secondary fuel cells provides redundancy in the unlikely event of a primary system failure. Power storage exists in the form of Nickel-Hydrogen batteries capable of powering the elevator under maximum loads.

Motion Analysis for Duplicate Frame Removal in Wireless Capsule Endoscope Video

OpenAIRE

Min Kook Choi; Hyun Gyu Lee; Ryan You; Byeong-Seok Shin; Sang-Chul Lee

2010-01-01

Wireless capsule Endoscopy (WCE) has rapidly shown its wide applications in medical domain last ten years thanks to its noninvasiveness for patients and support for thorough inspection through a patient-s entire digestive system including small intestine. However, one of the main barriers to efficient clinical inspection procedure is that it requires large amount of effort for clinicians to inspect huge data collected during the examination, i.e., over 55,000 frames in vi...

An artificial neural network architecture for non-parametric visual odometry in wireless capsule endoscopy

Science.gov (United States)

Dimas, George; Iakovidis, Dimitris K.; Karargyris, Alexandros; Ciuti, Gastone; Koulaouzidis, Anastasios

2017-09-01

Wireless capsule endoscopy is a non-invasive screening procedure of the gastrointestinal (GI) tract performed with an ingestible capsule endoscope (CE) of the size of a large vitamin pill. Such endoscopes are equipped with a usually low-frame-rate color camera which enables the visualization of the GI lumen and the detection of pathologies. The localization of the commercially available CEs is performed in the 3D abdominal space using radio-frequency (RF) triangulation from external sensor arrays, in combination with transit time estimation. State-of-the-art approaches, such as magnetic localization, which have been experimentally proved more accurate than the RF approach, are still at an early stage. Recently, we have demonstrated that CE localization is feasible using solely visual cues and geometric models. However, such approaches depend on camera parameters, many of which are unknown. In this paper the authors propose a novel non-parametric visual odometry (VO) approach to CE localization based on a feed-forward neural network architecture. The effectiveness of this approach in comparison to state-of-the-art geometric VO approaches is validated using a robotic-assisted in vitro experimental setup.

An artificial neural network architecture for non-parametric visual odometry in wireless capsule endoscopy

International Nuclear Information System (INIS)

Dimas, George; Iakovidis, Dimitris K; Karargyris, Alexandros; Ciuti, Gastone; Koulaouzidis, Anastasios

2017-01-01

Wireless capsule endoscopy is a non-invasive screening procedure of the gastrointestinal (GI) tract performed with an ingestible capsule endoscope (CE) of the size of a large vitamin pill. Such endoscopes are equipped with a usually low-frame-rate color camera which enables the visualization of the GI lumen and the detection of pathologies. The localization of the commercially available CEs is performed in the 3D abdominal space using radio-frequency (RF) triangulation from external sensor arrays, in combination with transit time estimation. State-of-the-art approaches, such as magnetic localization, which have been experimentally proved more accurate than the RF approach, are still at an early stage. Recently, we have demonstrated that CE localization is feasible using solely visual cues and geometric models. However, such approaches depend on camera parameters, many of which are unknown. In this paper the authors propose a novel non-parametric visual odometry (VO) approach to CE localization based on a feed-forward neural network architecture. The effectiveness of this approach in comparison to state-of-the-art geometric VO approaches is validated using a robotic-assisted in vitro experimental setup. (paper)

Detection of active bleeding from gastric antral vascular ectasia by capsule endoscopy

OpenAIRE

Ohira, Tetsuya; Hokama, Akira; Kinjo, Nagisa; Nakamoto, Manabu; Kobashigawa, Chiharu; Kise, Yuya; Yamashiro, Satoshi; Kinjo, Fukunori; Kuniyoshi, Yukio; Fujita, Jiro

2013-01-01

Gastric antral vascular ectasia (GAVE) has been recognized as one of the important causes of occult and obscure gastrointestinal bleeding. The diagnosis is typically made based on the characteristic endoscopic features, including longitudinal row of flat, reddish stripes radiating from the pylorus into the antrum that resemble the stripes on a watermelon. These appearances, however, can easily be misinterpreted as moderate to severe gastritis. Although it is believed that capsule endoscopy (C...

Coat/tether interactions – exceptions or rule?

Directory of Open Access Journals (Sweden)

Saskia eSchroeter

2016-05-01

Full Text Available Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers.

Assessing the speed of kill of hookworms, Ancylostoma caninum, by Advantage Multi ® for Dogs using endoscopic methods.

Science.gov (United States)

Lee, Alice C Y; Hostetler, Joseph A; Bowman, Dwight D

2014-08-29

Endoscopic capsules and endoscopy were used to assess the speed of kill and the clearance of hookworms in dogs experimentally infected with Ancylostoma caninum. A total of four adult dogs were inoculated in two separate cohorts comprised of two 4-year-old females and two 7-year-old males. Dogs were treated topically with Advantage Multi(®) for Dogs 13 days (Cohort 1) or 16 days (Cohort 2) after infection. Endoscopic imaging of the small intestine was carried out both pre- and post-treatment. Examination of the first cohort revealed that the worms had been cleared and the hookworm-induced lacerations were markedly diminished within 48 h of treatment. In the second cohort, endoscopic capsules were given the day of, the day after, and two days after treatment; within 24h of product administration, the worms had been removed with a concurrent reduction in observed lesions. Topical application of Advantage Multi(®) for Dogs rapidly removed worms from the small intestine of the dogs in this study as early as 24h post-treatment, with a marked reduction in the number of mucosal lesions seen. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Tether Elevator Crawler Systems (TECS)

Science.gov (United States)

Swenson, Frank R.

1987-01-01

One of the needs of the experimenters on the space station is access to steady and controlled-variation microgravity environments. A method of providing these environments is to place the experiment on a tether attached to the space station. This provides a high degree of isolation from structural oscillations and vibrations. Crawlers can move these experiments along the tethers to preferred locations, much like an elevator. This report describes the motion control laws developed for these crawlers and the testing of laboratory models of these tether elevator crawlers.

Utility of capsule endoscopy for evaluating anthelmintic efficacy in fully conscious dogs.

Science.gov (United States)

Lee, Alice C Y; Epe, Christian; Simpson, Kenneth W; Bowman, Dwight D

2011-11-01

The current accepted standard for evaluating the efficacy of gastrointestinal anthelmintic drugs is necropsy of infected animals followed by a comparison of worm counts between treated and non-treated groups. In this study capsule endoscopy, a minimally invasive method of imaging the small intestine of humans, is evaluated as a possible alternative to necropsy for the purposes of worm quantification in dogs. Eighteen Beagle dogs were included in this study. These dogs were part of a separate trial intended to determine the efficacy of various candidate parasiticides against Ancylostoma caninum via the necropsy standard. Dogs were inoculated with A. caninum L3s 4 weeks prior to treatment with one of the candidate compounds; a control group (n=8) received no treatment. Capsule endoscopy was performed 6-14 days post-treatment, followed by necropsy the following day. Seventeen dogs had complete examinations, i.e. the capsule traversed the small intestine and reached the colon within the battery life of the capsule. A strong correlation (r(s)=0.87, Pcapsule endoscopy and necropsy. There was no clear relationship between the ability of the capsule endoscope to detect hookworms and either visibility of the intestinal lumen or small intestinal transit time. Generation of a virtual spatial record of hookworm location from the capsule endoscopy data revealed a temporal trend, with the majority of worms present in the proximal small intestine in the morning versus the central to distal small intestine in the afternoon. Worm distribution as determined by capsule endoscopy closely resembled post-mortem findings. In conclusion, capsule endoscopy shows promise as an alternative to necropsy for the enumeration of A. caninum in the canine small intestine, although further work is required to improve completion rates and optimise intestinal examination. Copyright © 2011 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Molecular Structure of Membrane Tethers

NARCIS (Netherlands)

Baoukina, Svetlana; Marrink, Siewert J.; Tieleman, D. Peter

2012-01-01

Membrane tethers are nanotubes formed by a lipid bilayer. They play important functional roles in cell biology and provide an experimental window on lipid properties. Tethers have been studied extensively in experiments and described by theoretical models, but their molecular structure remains

Space Environmental Effects on Coated Tether Materials

Science.gov (United States)

Gittemeier, Keith A.; Hawk, Clark W.; Finckenor, Miria M.; Watts, Ed

2005-01-01

The University of Alabama in Huntsville s Propulsion Research Center has teamed with NASA's Marshall Space Flight Center (MSFC) to research the effects of atomic oxygen (AO) bombardment on coated tether materials. Tethers Unlimited Inc. has provided several candidate tether materials with various coatings for AO exposure in MSFC s Atomic Oxygen Beam Facility. Additional samples were exposed to ultraviolet (UV) radiation at MSFC. AO erodes most organic materials, and ultraviolet radiation embrittles polymers. This test series was performed to determine the effect of AO and UV on the mechanical integrity of tether materials that were treated with AO-protective coatings, such as polyhedral oligomeric silsesquioxane (POSS) or metallization. Both TUI's Multi-Application Survivable Tether (MAST) Experiment and Marshall Space Flight Center s Momentum Exchange Electrodynamic Reboost (MXER) programs will benefit from this research by helping to determine tether materials and coatings that give the longest life with the lowest mass penalty.

Membrane tethering complexes in the endosomal system

Directory of Open Access Journals (Sweden)

Anne eSpang

2016-05-01

Full Text Available Vesicles that are generated by endocytic events at the plasma membrane are destined to early endosomes. A prerequisite for proper fusion is the tethering of two membrane entities. Tethering of vesicles to early endosomes is mediated by the CORVET complex, while fusion of late endosomes with lysosomes depends on the HOPS complex. Recycling through the TGN and to the plasma membrane is facilitated by the GARP and EARP complexes, respectively. However, there are other tethering functions in the endosomal system as there are multiple pathways through which proteins can be delivered from endosomes to either the TGN or the plasma membrane. Furthermore, complexes that may be part of novel tethering complexes have been recently identified. Thus it is likely that more tethering factors exist. In this review, I will provide an overview of different tethering complexes of the endosomal system and discuss how they may provide specificity in membrane traffic.

Attitude control analysis of tethered de-orbiting

Science.gov (United States)

Peters, T. V.; Briz Valero, José Francisco; Escorial Olmos, Diego; Lappas, V.; Jakowski, P.; Gray, I.; Tsourdos, A.; Schaub, H.; Biesbroek, R.

2018-05-01

The increase of satellites and rocket upper stages in low earth orbit (LEO) has also increased substantially the danger of collisions in space. Studies have shown that the problem will continue to grow unless a number of debris are removed every year. A typical active debris removal (ADR) mission scenario includes launching an active spacecraft (chaser) which will rendezvous with the inactive target (debris), capture the debris and eventually deorbit both satellites. Many concepts for the capture of the debris while keeping a connection via a tether, between the target and chaser have been investigated, including harpoons, nets, grapples and robotic arms. The paper provides an analysis on the attitude control behaviour for a tethered de-orbiting mission based on the ESA e.Deorbit reference mission, where Envisat is the debris target to be captured by a chaser using a net which is connected to the chaser with a tether. The paper provides novel insight on the feasibility of tethered de-orbiting for the various mission phases such as stabilization after capture, de-orbit burn (plus stabilization), stabilization during atmospheric pass, highlighting the importance of various critical mission parameters such as the tether material. It is shown that the selection of the appropriate tether material while using simple controllers can reduce the effort needed for tethered deorbiting and can safely control the attitude of the debris/chaser connected with a tether, without the danger of a collision.

Tethering factors as organizers of intracellular vesicular traffic.

Science.gov (United States)

Yu, I-Mei; Hughson, Frederick M

2010-01-01

Intracellular trafficking entails the budding, transport, tethering, and fusion of transport vesicles and other membrane carriers. Here we review recent progress toward a mechanistic understanding of vesicle tethering. The known tethering factors are large complexes important for one or more intracellular trafficking pathways and are capable of interacting directly with many of the other principal components of the cellular trafficking machinery. Our review emphasizes recent developments in the in vitro reconstitution of vesicle tethering and the structural characterization of multisubunit tethering factors. The combination of these and other approaches has led to exciting progress toward understanding how these essential nanomachines work.

Atmospheric Electricity and Tethered Aerostats, Volume 1

Science.gov (United States)

1976-05-11

CATALOG NUMBER AFETR -TR-76-07 __ 4. TITLE (and Subtitle) -. TYPE OF REPORT & PERIOD COVERED ATMOSPHERIC ELECTRICITY AND TETHERED AEROSTATS, FINAL. 1...Electricity Faraday Capes Balloons Lightning Effects , Protection, Warning Systems Conducting and Non-Conducting ’Tethers Potential Geadient Anomalies...and identifying feasible protective systems. After a brief introductory section math models of effects of tethered balloons on surrounding

In Vivo Characterization of a Wireless Telemetry Module for a Capsule Endoscopy System Utilizing a Conformal Antenna.

Science.gov (United States)

Faerber, Julia; Cummins, Gerard; Pavuluri, Sumanth Kumar; Record, Paul; Rodriguez, Adrian R Ayastuy; Lay, Holly S; McPhillips, Rachael; Cox, Benjamin F; Connor, Ciaran; Gregson, Rachael; Clutton, Richard Eddie; Khan, Sadeque Reza; Cochran, Sandy; Desmulliez, Marc P Y

2018-02-01

This paper describes the design, fabrication, packaging, and performance characterization of a conformal helix antenna created on the outside of a capsule endoscope designed to operate at a carrier frequency of 433 MHz within human tissue. Wireless data transfer was established between the integrated capsule system and an external receiver. The telemetry system was tested within a tissue phantom and in vivo porcine models. Two different types of transmission modes were tested. The first mode, replicating normal operating conditions, used data packets at a steady power level of 0 dBm, while the capsule was being withdrawn at a steady rate from the small intestine. The second mode, replicating the worst-case clinical scenario of capsule retention within the small bowel, sent data with stepwise increasing power levels of -10, 0, 6, and 10 dBm, with the capsule fixed in position. The temperature of the tissue surrounding the external antenna was monitored at all times using thermistors embedded within the capsule shell to observe potential safety issues. The recorded data showed, for both modes of operation, a low error transmission of 10 -3 packet error rate and 10 -5 bit error rate and no temperature increase of the tissue according to IEEE standards.

An Unusual Endoscopic Image of a Submucosal Angiodysplasia

Directory of Open Access Journals (Sweden)

Rita Carvalho

2012-01-01

Full Text Available Obscure gastrointestinal bleeding is responsible for 2–10% of the cases of digestive bleeding. Angiodysplasia is the most common cause. The authors report a case of a 70-year-old female patient admitted to our Gastrointestinal Intensive Care Unit with a significant digestive bleeding. Standard upper and lower endoscopy showed no abnormalities, and we decided to perform a capsule enteroscopy that revealed a submucosal nodule with active bleeding in the jejunum. An intraoperative enteroscopy confirmed the presence of a small submucosal lesion with a central ulceration, and subsequently a segmental enterectomy was performed. Surprisingly, the histopathological diagnosis was angiodysplasia. The patient remains well after a two-year period of follow-up. We present this case of obscure/overt gastrointestinal bleeding to emphasize the role of capsule and intraoperative enteroscopy in the evaluation of these situations, and because of the unusual endoscopic appearance of the angiodysplasia responsible for the hemorrhage.

Tether Deployer And Brake

Science.gov (United States)

Carroll, Joseph A.; Alexander, Charles M.

1993-01-01

Design concept promises speed, control, and reliability. Scheme for deploying tether provides for fast, free, and snagless payout and fast, dependable braking. Developed for small, expendable tethers in outer space, scheme also useful in laying transoceanic cables, deploying guidance wires to torpedoes and missiles, paying out rescue lines from ship to ship via rockets, deploying antenna wires, releasing communication and power cables to sonobuoys and expendable bathythermographs, and in reeling out lines from fishing rods.

Review of deployment technology for tethered satellite systems

Science.gov (United States)

Yu, B. S.; Wen, H.; Jin, D. P.

2018-03-01

Tethered satellite systems (TSSs) have attracted significant attention due to their potential and valuable applications for scientific research. With the development of various launched on-orbit missions, the deployment of tethers is considered a crucial technology for operation of a TSS. Both past orbiting experiments and numerical results have shown that oscillations of the deployed tether due to the Coriolis force and environmental perturbations are inevitable and that the impact between the space tether and end-body at the end of the deployment process leads to complicated nonlinear phenomena. Hence, a set of suitable control methods plays a fundamental role in tether deployment. This review article summarizes previous work on aspects of the dynamics, control, and ground-based experiments of tether deployment. The relevant basic principles, analytical expressions, simulation cases, and experimental results are presented as well.

Dynamic multibody modeling for tethered space elevators

Science.gov (United States)

Williams, Paul

2009-08-01

This paper presents a fundamental modeling strategy for dealing with powered and propelled bodies moving along space tethers. The tether is divided into a large number of discrete masses, which are connected by viscoelastic springs. The tether is subject to the full range of forces expected in Earth orbit in a relatively simple manner. Two different models of the elevator dynamics are presented. In order to capture the effect of the elevator moving along the tether, the elevator dynamics are included as a separate body in both models. One model treats the elevator's motion dynamically, where propulsive and friction forces are applied to the elevator body. The second model treats the elevator's motion kinematically, where the distance along the tether is determined by adjusting the lengths of tether on either side of the elevator. The tether model is used to determine optimal configurations for the space elevator. A modal analysis of two different configurations is presented which show that the fundamental mode of oscillation is a pendular one around the anchor point with a period on the order of 160 h for the in-plane motion, and 24 h for the out-of-plane motion. Numerical simulation results of the effects of the elevator moving along the cable are presented for different travel velocities and different elevator masses.

Atmospheric Electricity and Tethered Aerostats, Volume 2

Science.gov (United States)

1976-05-11

EASTERN TEST RANGE PATRICK AIR FORCE BASE, FLORIDA 11 MAY 1976 028 099 AFETR -TR-76-07 ATMOSPHERIC ELECTRICITY AND ~TETHERED AEROSTATS, VOLUME 11 Range...number) Atmospheric Electricity Lightning- Effects , Protection, Warning Balloons Systems Conducting & Nonconducting Tethers Potential Gradient Anomalies...if necessary and Identify by block number) Part A, "Atmospheric Electrical Effects of and on Tethered Balloon Systems," by Latham includes airborne

GRASP: A multitasking tether

Directory of Open Access Journals (Sweden)

Catherine eRabouille

2016-01-01

Full Text Available Originally identified as Golgi stacking factors in vitro, the Golgi reassembly stacking protein (GRASP family has been shown to act as membrane tethers with multiple cellular roles. As an update to previous comprehensive reviews of the GRASP family (Vinke et al., 2011 (Giuliani et al., 2011;Jarvela and Linstedt, 2012, we outline here the latest findings concerning their diverse roles. New insights into the mechanics of GRASP-mediated tethering come from recent crystal structures. The models of how GRASP65 and GRASP55 tether membranes relate directly to their role in Golgi ribbon formation in mammalian cells and the unlinking of the ribbon at the onset of mitosis. However, it is also clear that GRASPs act outside the Golgi with roles at the ER and ER exit sites (ERES. Furthermore, the proteins of this family display other roles upon cellular stress, especially in mediating unconventional secretion of both transmembrane proteins (Golgi bypass and cytoplasmic proteins (through secretory autophagosomes.

Passivity-Based Control of a Rigid Electrodynamic Tether

DEFF Research Database (Denmark)

Larsen, Martin Birkelund; Blanke, Mogens

2011-01-01

Electrodynamic tethers provide actuation for performing orbit correction of spacecrafts. When an electrodynamic tether system is orbiting the Earth in an inclined orbit, periodic changes in the magnetic field result in a family of unstable periodic solutions in the attitude motion. This paper shows...... how these periodic solutions can be stabilized by controlling only the current through the tether. A port-controlled Hamiltonian formulation is employed to describe the tethered satellite system and a passive input-output connection is utilized in the control design. The control law consists of two...

Endoscopic training in gastroenterology fellowship: adherence to core curriculum guidelines.

Science.gov (United States)

Jirapinyo, Pichamol; Imaeda, Avlin B; Thompson, Christopher C

2015-12-01

The Gastroenterology Core Curriculum and American Society of Gastrointestinal Endoscopy provide guidelines for endoscopic training. Program adherence to these recommendations is unclear. This study aims to assess endoscopic training experience during fellowship. Questionnaire study. The questionnaire was circulated to US fellowship programs, with the assistance of the American Gastroenterological Association. Graduating third-year fellows. Seventy-three fellows returned the questionnaire. Nearly all fellows met the required numbers for esophagoduodenoscopy (98%) and colonoscopy (100%), with fewer meeting requirements for PEG (73%) and non-variceal hemorrhage (75%). The majority of fellows did not meet minimum numbers for variceal banding (40%), esophageal dilation (43%), capsule endoscopy (42%). Fellows rated training in cognitive aspects of endoscopy as 3.86 [1 (inadequate), 5 (excellent)] and reported greatest emphasis on interpreting endoscopic findings and least on virtual colonography. Quality indicators of endoscopy received little emphasis (rating of 3.04; p = 0.00001), with adenoma detection rate being least emphasized. Fifty-six percent of fellows reported having routine endoscopy conferences. Half of the programs have endoscopic simulators, with 15% of fellows being required to use simulation. Following direct hands-on experience, fellows rated external endoscopy courses (64%) as the next most useful experience. Many fellows do not meet required numbers for several endoscopic procedures, and quality indicators receive little emphasis during training. Most programs do not provide simulation training or hold regular endoscopy conferences. Fellowship programs should perform internal audits and make feasible adjustments. Furthermore, it may be time for professional societies to revisit training guidelines.

Assessing tether anchor labeling and usability in pickup trucks.

Science.gov (United States)

Klinich, Kathleen D; Manary, Miriam A; Malik, Laura A; Flannagan, Carol A; Jermakian, Jessica S

2018-04-03

The objective of this study was to investigate vehicle factors associated with child restraint tether use and misuse in pickup trucks and evaluate 4 labeling interventions designed to educate consumers on proper tether use. Volunteer testing was performed with 24 subjects and 4 different pickup trucks. Each subject performed 8 child restraint installations among the 4 pickups using 2 forward-facing restraints: a Britax Marathon G4.1 and an Evenflo Triumph. Vehicles were selected to represent 4 different implementations of tether anchors among pickups: plastic loop routers (Chevrolet Silverado), webbing routers (Ram), back wall anchors (Nissan Frontier), and webbing routers plus metal anchors (Toyota Tundra). Interventions included a diagram label, Quick Response (QR) Code linked to video instruction, coordinating text label, and contrasting text tag. Subjects used the child restraint tether in 93% of trials. However, tether use was completely correct in only 9% of trials. An installation was considered functional if the subject attached the tether to a tether anchor and had a tight installation (ignoring routing and head restraint position); 28% of subjects achieved a functional installation. The most common installation error was attaching the tether hook to the anchor/router directly behind the child restraint (near the top of the seatback) rather than placing the tether through the router and attaching it to the anchor in the adjacent seating position. The Nissan Frontier, with the anchor located on the back wall of the cab, had the highest rate of correct installations but also had the highest rate of attaching the tether to components other than the tether anchor (seat adjustor, child restraint storage hook, around head restraint). None of the labeling interventions had a significant effect on correct installation; not a single subject scanned the QR Code to access the video instruction. Subjects with the most successful installations spent extensive time

Mobile tethering: Overview, perspectives and challengess

NARCIS (Netherlands)

Constantinescu, M.; Onur, E.; Durmus, Y.; Nikou, S.; Reuver, M. de; Bouwman, H.; Djurica, M.; Glatz, P.M.

2014-01-01

Purpose: The purpose of this paper is to analyze mobile tethering from technological and social perspectives. Mobile tethering allows us to share cellular data connection with others over WiFi, Bluetooth or USB. Although the technology is ready and has promising outcomes, service providers and the

Membrane Tethering Complexes in the Endosomal System

OpenAIRE

Spang, Anne

2016-01-01

Vesicles that are generated by endocytic events at the plasma membrane are destined to early endosomes. A prerequisite for proper fusion is the tethering of two membrane entities. Tethering of vesicles to early endosomes is mediated by the class C core vacuole/endosome tethering (CORVET) complex, while fusion of late endosomes with lysosomes depends on the homotypic fusion and vacuole protein sorting (HOPS) complex. Recycling through the trans-Golgi network (TGN) and to the plasma membrane is...

Enabling Tethered Exploration on Mars, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Strong science motivations exist for exploring hard to reach terrain on Mars and the leading systems proposed to do so require tethers. While tethers are used...

Tether applications for space station

Science.gov (United States)

Nobles, W.

1986-01-01

A wide variety of space station applications for tethers were reviewed. Many will affect the operation of the station itself while others are in the category of research or scientific platforms. One of the most expensive aspects of operating the space station will be the continuing shuttle traffic to transport logistic supplies and payloads to the space station. If a means can be found to use tethers to improve the efficiency of that transportation operation, it will increase the operating efficiency of the system and reduce the overall cost of the space station. The concept studied consists of using a tether to lower the shuttle from the space station. This results in a transfer of angular momentum and energy from the orbiter to the space station. The consequences of this transfer is studied and how beneficial use can be made of it.

Investigation of electrodynamic stabilization and control of long orbiting tethers

Science.gov (United States)

Colombo, G.; Arnold, D.

1984-01-01

The state-of-the-art in tether modelling among participants in the Tethered Satellite System (TSS) Program, the slack tether and its behavior, and certain advanced applications of the tether to problems in orbital mechanics are identified. The features and applications of the TSS software set are reviewed. Modelling the slack tether analytically with as many as 50 mass points and the application of this new model to a study of the behavior of a broken tether near the Shuttle are described. A reel control algorithm developed by SAO and examples of its use are described, including an example which also demonstrates the use of the tether in transferring a heavy payload from a low-orbiting Shuttle to a high circular orbit. Capture of a low-orbiting payload by a Space Station in high circular orbit is described. Energy transfer within a dumbbell-type spacecraft by cyclical reeling operations or gravitational effects on the natural elasticity of the connecting tether, it is shown, can circularize the orbit of the spacecraft.

Flowing Plasma Interaction with an Electric Sail Tether Element

Science.gov (United States)

Schneider, Todd; Vaughn, Jason; Wright, Kenneth; Anderson, Allen; Stone, Nobie

2017-01-01

Harnessing the power of the solar wind, an Electric Sail, or E-sail, is a relatively new concept that promises to deliver high speed propellant-less propulsion. The electric sail is an invention made in 2006 at the Kumpula Space Centre in Finland by Pekka Janhunen [Janhunen and Sandroos, 2007]. At its core, an electric sail utilizes multiple positively biased tethers which exchange momentum with solar wind protons via the repelling electric field established around each tether, in other words, by reflecting the solar wind protons. Recognizing the solar wind is a plasma, the effective repelling area of each tether is increased significantly by the formation a plasma sheath around each tether. Fig. 1 shows schematically a spacecraft employing an electric sail. The positive voltage bias (greater than10kV) applied to each tether naturally results in electron collection. Therefore, the electric sail concept necessarily includes an electron source (electron gun) to return collected electrons to space and maintain the positive bias of the tether system.

[The extended endoscopic endonasal transsphenoidal approach in surgery for epidermoid cysts of the chiasmatic region].

Science.gov (United States)

Fomichev, D V; Kalinin, P L; Kutin, M A; Sharipov, O I; Chernov, I V

Surgical treatment for epidermoid cysts of the chiasmatic region is a challenge because of the tendency to a massive spread of epidermoid masses through the cerebrospinal fluid pathways and a significant lesion deviation from the midline. To analyze capabilities of the extended endoscopic endonasal transsphenoidal approach in surgery for epidermoid cysts. The study included 6 patients with epidermoid cysts of the chiasmatic region who were operated on using the extended anterior endoscopic endonasal transsphenoidal approach at the Burdenko Neurosurgical Institute in the past 5 years. Epidermoid masses were completely removed in 5 patients; in none of the cases, complete removal of the epidermoid cyst capsule was achieved. There were no cases of vision deterioration and the development of new focal neurological symptoms. One female patient developed hypopituitary disorders in the postoperative period. There was no recurrence of epidermoid cysts during follow-up. Removal of epidermoid cysts of the chiasmatic region using the extended anterior endoscopic transsphenoidal approach may be an alternative to transcranial microsurgery.

Modeling and Simulation of a Tethered Harpoon for Comet Sampling

Science.gov (United States)

Quadrelli, Marco B.

2014-01-01

This paper describes the development of a dynamic model and simulation results of a tethered harpoon for comet sampling. This model and simulation was done in order to carry out an initial sensitivity analysis for key design parameters of the tethered system. The harpoon would contain a canister which would collect a sample of soil from a cometary surface. Both a spring ejected canister and a tethered canister are considered. To arrive in close proximity of the spacecraft at the end of its trajectory so it could be captured, the free-flying canister would need to be ejected at the right time and with the proper impulse, while the tethered canister must be recovered by properly retrieving the tether at a rate that would avoid an excessive amplitude of oscillatory behavior during the retrieval. The paper describes the model of the tether dynamics and harpoon penetration physics. The simulations indicate that, without the tether, the canister would still reach the spacecraft for collection, that the tether retrieval of the canister would be achievable with reasonable fuel consumption, and that the canister amplitude upon retrieval would be insensitive to variations in vertical velocity dispersion.

Tension waves in tethered satellite cables

Science.gov (United States)

Lallman, F. J.

1984-01-01

A one-degree-of-freedom simulation of the Tethered Satellite System (TSS) was programmed using a distributed system model of the tether based on the one-dimensional wave equation. This model represents the time varying tension profile along the tether as the sum of two traveling waves of tension moving in opposite directions. A control loop was devised which combines a deployment rate command with the measured tension at the deployer to produce a smooth, stable rate of deployment of the subsatellite. Simulation results show a buildup of periodic bursts of high frequency oscillation in tension. This report covers the mathematical modelling and simulation results and explains the reason for the observed oscillations. The design of a possible vibration damping device is discussed.

The stochastic dynamics of tethered microcantilevers in a viscous fluid

Energy Technology Data Exchange (ETDEWEB)

Robbins, Brian A.; Paul, Mark R. [Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Radiom, Milad; Ducker, William A. [Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Walz, John Y. [Department of Chemical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States)

2014-10-28

We explore and quantify the coupled dynamics of a pair of micron scale cantilevers immersed in a viscous fluid that are also directly tethered to one another at their tips by a spring force. The spring force, for example, could represent the molecular stiffness or elasticity of a biomolecule or material tethered between the cantilevers. We use deterministic numerical simulations with the fluctuation-dissipation theorem to compute the stochastic dynamics of the cantilever pair for the conditions of experiment when driven only by Brownian motion. We validate our approach by comparing directly with experimental measurements in the absence of the tether which shows excellent agreement. Using numerical simulations, we quantify the correlated dynamics of the cantilever pair over a range of tether stiffness. Our results quantify the sensitivity of the auto- and cross-correlations of equilibrium fluctuations in cantilever displacement to the stiffness of the tether. We show that the tether affects the magnitude of the correlations which can be used in a measurement to probe the properties of an attached tethering substance. For the configurations of current interest using micron scale cantilevers in water, we show that the magnitude of the fluid coupling between the cantilevers is sufficiently small such that the influence of the tether can be significant. Our results show that the cross-correlation is more sensitive to tether stiffness than the auto-correlation indicating that a two-cantilever measurement has improved sensitivity when compared with a measurement using a single cantilever.

Models of dynamic extraction of lipid tethers from cell membranes

International Nuclear Information System (INIS)

Nowak, Sarah A; Chou, Tom

2010-01-01

When a ligand that is bound to an integral membrane receptor is pulled, the membrane and the underlying cytoskeleton can deform before either the membrane delaminates from the cytoskeleton or the ligand detaches from the receptor. If the membrane delaminates from the cytoskeleton, it may be further extruded and form a membrane tether. We develop a phenomenological model for this process by assuming that deformations obey Hooke's law up to a critical force at which the cell membrane locally detaches from the cytoskeleton and a membrane tether forms. We compute the probability of tether formation and show that tethers can be extruded only within an intermediate range of force loading rates and pulling velocities. The mean tether length that arises at the moment of ligand detachment is computed as are the force loading rates and pulling velocities that yield the longest tethers

Lyapunov Orbits in the Jupiter System Using Electrodynamic Tethers

Science.gov (United States)

Bokelmann, Kevin; Russell, Ryan P.; Lantoine, Gregory

2013-01-01

Various researchers have proposed the use of electrodynamic tethers for power generation and capture from interplanetary transfers. The effect of tether forces on periodic orbits in Jupiter-satellite systems are investigated. A perturbation force is added to the restricted three-body problem model and a series of simplifications allows development of a conservative system that retains the Jacobi integral. Expressions are developed to find modified locations of equilibrium positions. Modified families of Lyapunov orbits are generated as functions of tether size and Jacobi integral. Zero velocity curves and stability analyses are used to evaluate the dynamical properties of tether-modified orbits.

The PROPEL Electrodynamic Tether Demonstration Mission

Science.gov (United States)

Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

2012-01-01

The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

Use of top tethers with forward-facing child restraints: observations and driver interviews.

Science.gov (United States)

Eichelberger, Angela H; Decina, Lawrence E; Jermakian, Jessica S; McCartt, Anne T

2014-02-01

Despite the safety benefits, many parents do not use top tethers with forward-facing child restraints. Detailed information was collected about why parents are not using tethers. The sample included 479 drivers who had forward-facing child restraints installed in passenger vehicles equipped with tether anchors. The survey was conducted primarily at shopping centers, recreation facilities, child care facilities, car seat check events, and health care facilities in mostly suburban areas surrounding Philadelphia, Washington, DC, Fredericksburg (VA), and Seattle. Drivers were surveyed about their knowledge and use of tethers and experience with child restraints. Tether use was observed to verify whether tethers were being used correctly. Fifty-six percent of forward-facing child restraints were installed with the tether; 39% were installed with the tether used correctly. The tether was used with 71% of LATCH lower anchor installations and 33% of seat belt installations. Drivers who installed child restraints without tethers most often said they did not know about the tether or how to use it. Although the tether use rate was slightly higher in the current research than in previous studies, many parents and caregivers still use forward-facing child restraints without attaching the tether. Because the main problem is lack of awareness of the tether or how to use it, public education should focus specifically on the safety benefits of tethers and how to use them. Information about why caregivers fail to use top tethers is potentially useful to child restraint manufacturers, child passenger safety technicians, and others who work with parents to improve motor vehicle safety. Copyright © 2013 Elsevier Ltd and National Safety Council. All rights reserved.

Numerical modelling of elastic space tethers

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall; Palmer, P. L.; Roberts, R. M.

2012-01-01

In this paper the importance of the ill-posedness of the classical, non-dissipative massive tether model on an orbiting tether system is studied numerically. The computations document that via the regularisation of bending resistance a more reliable numerical integrator can be produced. Furthermo....... It is also shown that on the slow manifold the dynamics of the satellites are well-approximated by the finite dimensional slack-spring model....

Modeling and Control of Electrodynamic Tethers - an Energy and Topology Approach

DEFF Research Database (Denmark)

Larsen, Martin Birkelund

A space tether is a cable used to connect spacecrafts in an orbiting structure. If an electrical current is lead through the tether, it can be utilized to provide propulsion for the spacecraft. In this case the cable is referred to as an electrodynamic tether. The system utilizes the magnetic field...... of the Earth for creating a Lorentz force along the tether which occur when a current carrying wire operates in a magnetic field. The use of electrodynamic tethers are interesting since they operate solely on electrical energy, which can be provided by solar panels of the spacecrafts. In this way the amount...... when using electrodynamic tethers is that the force created along the tether is based on an external uncontrollable condition, namely the magnetic field. Even whit a known model of the magnetic field, limitations to the creation of the Lorentz force still exists, since the force can only be generated...

Wireless capsule endoscopy for diagnosis of acute intestinal graft-versus-host disease.

Science.gov (United States)

Neumann, Susanne; Schoppmeyer, Konrad; Lange, Thoralf; Wiedmann, Marcus; Golsong, Johannes; Tannapfel, Andrea; Mossner, Joachim; Niederwieser, Dietger; Caca, Karel

2007-03-01

The small intestine is the most common location of intestinal graft-versus-host disease (GVHD). EGD with duodenal biopsies yields the highest diagnostic sensitivity, but the jejunum and ileum are not accessible by regular endoscopy. In contrast, wireless capsule endoscopy (WCE) is a noninvasive imaging procedure offering complete evaluation of the small intestine. The objective was to compare the diagnostic value of EGD, including biopsies, with the results of WCE in patients with acute intestinal symptoms who received allogeneic blood stem cell transplantation and to analyze the appearance and distribution of acute intestinal GVHD lesions in these patients. An investigator-blinded, single-center prospective study. Patients with acute intestinal symptoms after allogeneic stem cell transplantation underwent both EGD and WCE within 24 hours. Clinical data were recorded during 2 months of follow-up. Fourteen consecutive patients with clinical symptoms of acute intestinal GVHD were recruited. In 1 patient, the capsule remained in the stomach and was removed endoscopically. In 7 of 13 patients who could be evaluated, acute intestinal GVHD was diagnosed by EGD with biopsies, but 3 of these would have been missed by EGD alone. In all 7 patients with histologically confirmed acute intestinal GVHD, WCE revealed typical signs of GVHD. Lesions were scattered throughout the small intestine, but were most accentuated in the ileum. This study had a small number of patients. WCE, which is less invasive than EGD with biopsies, showed a comparable sensitivity and a high negative predictive value for diagnosing acute intestinal GVHD. It may be helpful to avoid repeated endoscopic procedures in patients who have undergone stem cell transplantation.

One kilometer (1 km) electric solar wind sail tether produced automatically.

Science.gov (United States)

Seppänen, Henri; Rauhala, Timo; Kiprich, Sergiy; Ukkonen, Jukka; Simonsson, Martin; Kurppa, Risto; Janhunen, Pekka; Hæggström, Edward

2013-09-01

We produced a 1 km continuous piece of multifilament electric solar wind sail tether of μm-diameter aluminum wires using a custom made automatic tether factory. The tether comprising 90,704 bonds between 25 and 50 μm diameter wires is reeled onto a metal reel. The total mass of 1 km tether is 10 g. We reached a production rate of 70 m/24 h and a quality level of 1‰ loose bonds and 2‰ rebonded ones. We thus demonstrated that production of long electric solar wind sail tethers is possible and practical.

Thermo-mechanical actuator-based miniature tagging module for localization in capsule endoscopy

Science.gov (United States)

Chandrappan, Jayakrishnan; Ruiqi, Lim; Su, Nandar; Yen Yi, Germaine Hoe; Vaidyanathan, Kripesh

2011-04-01

Capsule endoscopy is a frontline medical diagnostic tool for the gastro intestinal tract disorders. During diagnosis, efficient localization techniques are essential to specify a pathological area that may require further diagnosis or treatment. This paper presents the development of a miniature tagging module that relies on a novel concept to label the region of interest and has the potential to integrate with a capsule endoscope. The tagging module is a compact thermo-mechanical actuator loaded with a biocompatible micro tag. A low power microheater attached to the module serves as the thermal igniter for the mechanical actuator. At optimum temperature, the actuator releases the micro tag instantly and penetrates the mucosa layer of a GI tract, region of interest. Ex vivo animal trials are conducted to verify the feasibility of the tagging module concept. X-ray imaging is used to detect the location of the micro tag embedded in the GI tract wall. The method is successful, and radiopaque micro tags can provide valuable pre-operative position information on the infected area to facilitate further clinical procedures.

Selected Tether Applications Cost Model

Science.gov (United States)

Keeley, Michael G.

1988-01-01

Diverse cost-estimating techniques and data combined into single program. Selected Tether Applications Cost Model (STACOM 1.0) is interactive accounting software tool providing means for combining several independent cost-estimating programs into fully-integrated mathematical model capable of assessing costs, analyzing benefits, providing file-handling utilities, and putting out information in text and graphical forms to screen, printer, or plotter. Program based on Lotus 1-2-3, version 2.0. Developed to provide clear, concise traceability and visibility into methodology and rationale for estimating costs and benefits of operations of Space Station tether deployer system.

TMBM: Tethered Micro-Balloons on Mars

Science.gov (United States)

Sims, M. H.; Greeley, R.; Cutts, J. A.; Yavrouian, A. H.; Murbach, M.

2000-01-01

The use of balloons/aerobots on Mars has been under consideration for many years. Concepts include deployment during entry into the atmosphere from a carrier spacecraft, deployment from a lander, use of super-pressurized systems for long duration flights, 'hot-air' systems, etc. Principal advantages include the ability to obtain high-resolution data of the surface because balloons provide a low-altitude platform which moves relatively slowly. Work conducted within the last few years has removed many of the technical difficulties encountered in deployment and operation of balloons/aerobots on Mars. The concept proposed here (a tethered balloon released from a lander) uses a relatively simple approach which would enable aspects of Martian balloons to be tested while providing useful and potentially unique science results. Tethered Micro-Balloons on Mars (TMBM) would be carried to Mars on board a future lander as a stand-alone experiment having a total mass of one to two kilograms. It would consist of a helium balloon of up to 50 cubic meters that is inflated after landing and initially tethered to the lander. Its primary instrumentation would be a camera that would be carried to an altitude of up to tens of meters above the surface. Imaging data would be transmitted to the lander for inclusion in the mission data stream. The tether would be released in stages allowing different resolutions and coverage. In addition during this staged release a lander camera system may observe the motion of the balloon at various heights above he lander. Under some scenarios upon completion of the primary phase of TMBM operations, the tether would be cut, allowing TMBM to drift away from the landing site, during which images would be taken along the ground.

Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

KAUST Repository

Srivastava, Samanvaya

2012-04-17

Phase behavior of poly(ethylene glycol) (PEG) tethered silica nanoparticles dispersed in PEG hosts is investigated using small-angle X-ray scattering. Phase separation in dispersions of densely grafted nanoparticles is found to display strikingly different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer composites incorporating results from this as well as various other contemporary studies is presented. We show that in the range of moderate to high grafting densities the dispersion state of nanoparticles in composites is largely insensitive to the grafting density of the tethered chains and chemistry of the polymer host. Instead, the ratio of the particle diameter to the size of the tethered chain and the ratio of the molecular weights of the host and tethered polymer chains (P/N) are shown to play a dominant role. Additionally, we find that well-functionalized nanoparticles form stable dispersions in their polymer host beyond the P/N limit that demarcates the wetting/dewetting transition in polymer brushes on flat substrates interacting with polymer melts. A general strategy for achieving uniform nanoparticle dispersion in polymers is proposed. © 2012 American Chemical Society.

Small-bowel neoplasms in patients undergoing video capsule endoscopy

DEFF Research Database (Denmark)

Rondonotti, E; Pennazio, M; Toth, E

2008-01-01

BACKGROUND AND STUDY AIM: Small-bowel tumors account for 1% - 3% of all gastrointestinal neoplasms. Recent studies with video capsule endoscopy (VCE) suggest that the frequency of these tumors may be substantially higher than previously reported. The aim of the study was to evaluate the frequency......, clinical presentation, diagnostic/therapeutic work-up, and endoscopic appearance of small-bowel tumors in a large population of patients undergoing VCE. PATIENTS AND METHODS: Identification by a questionnaire of patients with VCE findings suggesting small-bowel tumors and histological confirmation...... of the neoplasm seen in 29 centers of 10 European Countries. RESULTS: Of 5129 patients undergoing VCE, 124 (2.4%) had small-bowel tumors (112 primary, 12 metastatic). Among these patients, indications for VCE were: obscure gastrointestinal bleeding (108 patients), abdominal pain (9), search for primary neoplasm...

Pilot cohort study of endoscopic botulinum neurotoxin injection in Parkinson's disease.

Science.gov (United States)

Triadafilopoulos, George; Gandhy, Rita; Barlow, Carrolee

2017-11-01

Gastrointestinal symptoms, such as dysphagia, postprandial bloating, and defecatory straining are common in Parkinson's Disease (PD) and they impact quality of life. Endoscopic botulinum neurotoxin (BoNT) injection has been used in the treatment of dysphagia, gastroparesis and chronic anismus. To examine the feasibility, safety and efficacy of endoscopically delivered BoNT injection to distal esophagus, pylorus or anal canal aiming at relieving regional gastrointestinal symptoms in patients with PD. This is a retrospective open cohort pilot study to assess the clinical response to endoscopic BoNT injection on selected PD patients with symptoms and identifiable abnormalities on high-resolution manometry and wireless motility capsule, to generate early uncontrolled data on feasibility, tolerability, safety and efficacy. Baseline symptoms and response to therapy were assessed by questionnaires. Fourteen PD patients (10 M:4 F), mean age 73 (range: 62-93) were treated. Three patients had esophageal Botox for ineffective esophageal motility (IEM) (n = 1), esophago-gastric junction outlet obstruction (EGJOO) & IEM (n = 1), and diffuse esophageal spasm (DES) (n = 1). Nine patients were treated with pyloric BoNT injection for gastroparesis with mean gastric transit time of 21.2 h; range 5.2-44.2 h. Two patients received anal Botox for defecatory dyssynergia ((Type I) (n = 1) and overlap (slow-transit and dyssynergic) constipation (n = 1). Endoscopic BoNT injection (100-200 units) was well tolerated and there were no significant adverse events. Endoscopic BoNT injection to esophagus, pylorus or anal canal is safe, well-tolerated and leads to symptomatic improvement that lasts up to several months. The procedure can be repeated as needed and combined with other therapies. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Science and Applications Tethered Platform (SATP) project

Science.gov (United States)

Merlina, P.

1986-01-01

The capabilities of tether systems in orbit are going to be demonstrated by the first planned flights of the Tethered Satellite System (TSS). These test flights will investigate the properties of tether systems as low altitude atmospheric research facilities and as electric power generators. Studies are being conducted with the purpose of testing a variety of concepts and approaches. A comparative analysis of results will allow the choosing of the most promising ideas for further development. The broad range of applications presently under study include applications in electrodynamics, transportation, microgravity in addition to basic research. The SATP project definition study is now about midway through its first phase. The analyses conducted have led to an appraisal of users interest in the project and to a deeper understanding of the problems associated with large, long-lived tether systems in space. In addition, two specialized platform designs, devoted to microgravity and precise pointing applications, are being studied because of their potential usefulness and the promise of technical feasibility.

Relaxation Dynamics of Nanoparticle-Tethered Polymer Chains

KAUST Repository

Kim, Sung A

2015-09-08

© 2015 American Chemical Society. Relaxation dynamics of nanoparticle-tethered cis-1,4-polyisoprene (PI) are investigated using dielectric spectroscopy and rheometry. A model system composed of polymer chains densely grafted to spherical SiO2 nanoparticles to form self-suspended suspensions facilitates detailed studies of slow global chain and fast segmental mode dynamics under surface and geometrical confinement-from experiments performed in bulk materials. We report that unentangled polymer molecules tethered to nanoparticles relax far more slowly than their tethered entangled counterparts. Specifically, at fixed grafting density we find, counterintuitively, that increasing the tethered polymer molecular weight up to values close to the entanglement molecular weight speeds up chain relaxation dynamics. Decreasing the polymer grafting density for a fixed molecular weight has the opposite effect: it dramatically slows down chain relaxation, increases interchain coupling, and leads to a transition in rheological response from simple fluid behavior to viscoelastic fluid behavior for tethered PI chains that are unentangled by conventional measures. Increasing the measurement temperature produces an even stronger elastic response and speeds up molecular relaxation at a rate that decreases with grafting density and molecular weight. These observations are discussed in terms of chain confinement driven by crowding between particles and by the existence of an entropic attractive force produced by the space-filling constraint on individual chains in a self-suspended material. Our results indicate that the entropic force between densely grafted polymer molecules couples motions of individual chains in an analogous manner to reversible cross-links in associating polymers.

High-quality endoscope reprocessing decreases endoscope contamination.

Science.gov (United States)

Decristoforo, P; Kaltseis, J; Fritz, A; Edlinger, M; Posch, W; Wilflingseder, D; Lass-Flörl, C; Orth-Höller, D

2018-02-24

Several outbreaks of severe infections due to contamination of gastrointestinal (GI) endoscopes, mainly duodenoscopes, have been described. The rate of microbial endoscope contamination varies dramatically in literature. The aim of this multicentre prospective study was to evaluate the hygiene quality of endoscopes and automated endoscope reprocessors (AERs) in Tyrol/Austria. In 2015 and 2016, a total of 463 GI endoscopes and 105 AERs from 29 endoscopy centres were analysed by a routine (R) and a combined routine and advanced (CRA) sampling procedure and investigated for microbial contamination by culture-based and molecular-based analyses. The contamination rate of GI endoscopes was 1.3%-4.6% according to the national guideline, suggesting that 1.3-4.6 patients out of 100 could have had contacts with hygiene-relevant microorganisms through an endoscopic intervention. Comparison of R and CRA sampling showed 1.8% of R versus 4.6% of CRA failing the acceptance criteria in phase I and 1.3% of R versus 3.0% of CRA samples failing in phase II. The most commonly identified indicator organism was Pseudomonas spp., mainly Pseudomonas oleovorans. None of the tested viruses were detected in 40 samples. While AERs in phase I failed (n = 9, 17.6%) mainly due to technical faults, phase II revealed lapses (n = 6, 11.5%) only on account of microbial contamination of the last rinsing water, mainly with Pseudomonas spp. In the present study the contamination rate of endoscopes was low compared with results from other European countries, possibly due to the high quality of endoscope reprocessing, drying and storage. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Climber Motion Optimization for the Tethered Space Elevator

NARCIS (Netherlands)

Williams, P.; Ockels, W.J.

The tethered space elevator could provide a revolutionary means for enabling cheap transportation to geostationary altitude and beyond. Assuming that such a system can be built, one of the dynamic design problems is determining a means of moving the elevator along the tether so as to minimize the

Capsule Endoscopy in the Assessment of Obscure Gastrointestinal Bleeding: An Evidence-Based Analysis

Science.gov (United States)

2015-01-01

Background Obscure gastrointestinal bleeding (OGIB) is defined as persistent or recurrent bleeding associated with negative findings on upper and lower gastrointestinal (GI) endoscopic evaluations. The diagnosis and management of patients with OGIB is particularly challenging because of the length and complex loops of the small intestine. Capsule endoscopy (CE) is 1 diagnostic modality that is used to determine the etiology of bleeding. Objectives The objective of this analysis was to review the diagnostic accuracy, safety, and impact on health outcomes of CE in patients with OGIB in comparison with other diagnostic modalities. Data Sources A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2007 and 2013. Review Methods Data on diagnostic accuracy, safety, and impact on health outcomes were abstracted from included studies. Quality of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results The search yielded 1,189 citations, and 24 studies were included. Eight studies reported diagnostic accuracy comparing CE with other diagnostic modalities. Capsule endoscopy has a higher sensitivity and lower specificity than magnetic resonance enteroclysis, computed tomography, and push enteroscopy. Capsule endoscopy has a good safety profile with few adverse events, although comparative safety data with other diagnostic modalities are limited. Capsule endoscopy is associated with no difference in patient health-related outcomes such as rebleeding or follow-up treatment compared with push enteroscopy, small-bowel follow-through, and angiography. Limitations There was significant heterogeneity in estimates of diagnostic accuracy, which prohibited a statistical summary of findings. The analysis was also limited by the fact that there is no

The effects of tether placement on antibody stability on surfaces

Science.gov (United States)

Grawe, Rebecca W.; Knotts, Thomas A.

2017-06-01

Despite their potential benefits, antibody microarrays have fallen short of performing reliably and have not found widespread use outside of the research setting. Experimental techniques have been unable to determine what is occurring on the surface of an atomic level, so molecular simulation has emerged as the primary method of investigating protein/surface interactions. Simulations of small proteins have indicated that the stability of the protein is a function of the residue on the protein where a tether is placed. The purpose of this research is to see whether these findings also apply to antibodies, with their greater size and complexity. To determine this, 24 tethering locations were selected on the antibody Protein Data Bank (PDB) ID: 1IGT. Replica exchange simulations were run on two different surfaces, one hydrophobic and one hydrophilic, to determine the degree to which these tethering sites stabilize or destabilize the antibody. Results showed that antibodies tethered to hydrophobic surfaces were in general less stable than antibodies tethered to hydrophilic surfaces. Moreover, the stability of the antibody was a function of the tether location on hydrophobic surfaces but not hydrophilic surfaces.

Endoscopic retrograde cholangiopancreatography and endoscopic ...

African Journals Online (AJOL)

An approach to suspected gallstone pancreatitis'based on endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy (ES) was adopted in 1976 and was followed in 29 patients. ERCp became the routine method of early biliary tract assessment when gallstone pancreatitis was suspected on ...

Tethered Pyrotechnic Apparatus for Acquiring a Ground Sample

Science.gov (United States)

Jones, Jack; Zimmerman, Wayne; Wu, Jiunn Jenq; Badescu, Mircea; Sherrit, Stewart

2009-01-01

A proposed alternative design for the balloon-borne ground-sampling system described in the immediately preceding article would not rely on free fall to drive a harpoonlike sample-collecting device into the ground. Instead, the harpoon-like sample-collecting device would be a pyrotechnically driven, tethered projectile. The apparatus would include a tripod that would be tethered to the gondola. A gun for shooting the projectile into the ground would be mounted at the apex of the tripod. The gun would include an electronic trigger circuit, a chamber at the breech end containing a pyrotechnic charge, and a barrel. A sabot would be placed in the barrel just below the pyrotechnic charge, and the tethered projectile would be placed in the barrel just below the sabot. The tripod feet would be equipped with contact sensors connected to the trigger circuit. In operation, the tripod would be lowered to the ground on its tether. Once contact with the ground was detected by the sensors on all three tripod feet, the trigger circuit would fire the pyrotechnic charge to drive the projectile into the ground. (Requiring contact among all three tripod feet and the ground would ensure that the projectile would be fired into the ground, rather than up toward the gondola or the balloon.) The tethered projectile would then be reeled back up to the gondola for analysis of the sample.

Posterior capsule opacification.

Science.gov (United States)

Wormstone, I Michael; Wang, Lixin; Liu, Christopher S C

2009-02-01

Posterior Capsule Opacification (PCO) is the most common complication of cataract surgery. At present the only means of treating cataract is by surgical intervention, and this initially restores high visual quality. Unfortunately, PCO develops in a significant proportion of patients to such an extent that a secondary loss of vision occurs. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens. The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. However, on the remaining anterior capsule, lens epithelial cells stubbornly reside despite enduring the rigours of surgical trauma. This resilient group of cells then begin to re-colonise the denuded regions of the anterior capsule, encroach onto the intraocular lens surface, occupy regions of the outer anterior capsule and most importantly of all begin to colonise the previously cell-free posterior capsule. Cells continue to divide, begin to cover the posterior capsule and can ultimately encroach on the visual axis resulting in changes to the matrix and cell organization that can give rise to light scatter. This review will describe the biological mechanisms driving PCO progression and discuss the influence of IOL design, surgical techniques and putative drug therapies in regulating the rate and severity of PCO.

Fluid-membrane tethers: minimal surfaces and elastic boundary layers.

Science.gov (United States)

Powers, Thomas R; Huber, Greg; Goldstein, Raymond E

2002-04-01

Thin cylindrical tethers are common lipid bilayer membrane structures, arising in situations ranging from micromanipulation experiments on artificial vesicles to the dynamic structure of the Golgi apparatus. We study the shape and formation of a tether in terms of the classical soap-film problem, which is applied to the case of a membrane disk under tension subject to a point force. A tether forms from the elastic boundary layer near the point of application of the force, for sufficiently large displacement. Analytic results for various aspects of the membrane shape are given.

New endoscope shaft for endoscopic transsphenoidal pituitary surgery.

NARCIS (Netherlands)

Lindert, E.J. van; Grotenhuis, J.A.

2005-01-01

OBJECTIVE: To describe a new endoscope shaft developed for suction-aspiration during endoscopic transsphenoidal pituitary surgery. METHODS: A custom-made shaft for a Wolf endoscope (Richard Wolf GmbH, Knittlingen, Germany) was developed with a height of 10 mm and a width of 5 mm, allowing an

Wireless Capsule Endoscopy Detects Meckel’s Diverticulum in a Child with Unexplained Intestinal Blood Loss

Directory of Open Access Journals (Sweden)

I. Xinias

2012-10-01

Full Text Available Meckel’s diverticulum (MD is the most common congenital anomaly of the gastrointestinal (GI tract, affecting about 2% of the population. Most cases of Meckel’s diverticula are asymptomatic. The diagnosis of symptomatic MD is often difficult to make. We report the case of an 8-year-old boy who presented with GI bleeding due to MD. The diagnostic difficulties after an initial negative endoscopic evaluation and the diagnostic value of the various endoscopic procedures are discussed. The patient had suffered from bright red stools for 20 h before hospital admission. GI scintigraphy with 99mTc-Na-pertechnetate was negative for heterotopic gastric tissue in the small bowel area. Colonoscopy performed in order to exclude Crohn’s disease was also negative. He was placed on ranitidine at a dose of 6 mg/kg body weight twice daily. The patient remained asymptomatic over a period of 6 months before he was readmitted due to macroscopic rectal bleeding. Upper endoscopy and colonoscopy used to investigate the source of bleeding showed normal macroscopic findings. Radiolabeling of blood constituents with 99mTc on delayed imaging showed radionucleotide concentration in the ascending and transverse colon suggestive of a lesion in the ileocecal area. Further investigation with the use of wireless capsule endoscopy revealed a MD. Wireless capsule endoscopy may thus be indicated for patients with GI blood loss when other diagnostic methods, such as upper and lower endoscopy and colonoscopy, have failed to identify the source of bleeding.

Autonomous Vision-Based Tethered-Assisted Rover Docking

Science.gov (United States)

Tsai, Dorian; Nesnas, Issa A.D.; Zarzhitsky, Dimitri

2013-01-01

Many intriguing science discoveries on planetary surfaces, such as the seasonal flows on crater walls and skylight entrances to lava tubes, are at sites that are currently inaccessible to state-of-the-art rovers. The in situ exploration of such sites is likely to require a tethered platform both for mechanical support and for providing power and communication. Mother/daughter architectures have been investigated where a mother deploys a tethered daughter into extreme terrains. Deploying and retracting a tethered daughter requires undocking and re-docking of the daughter to the mother, with the latter being the challenging part. In this paper, we describe a vision-based tether-assisted algorithm for the autonomous re-docking of a daughter to its mother following an extreme terrain excursion. The algorithm uses fiducials mounted on the mother to improve the reliability and accuracy of estimating the pose of the mother relative to the daughter. The tether that is anchored by the mother helps the docking process and increases the system's tolerance to pose uncertainties by mechanically aligning the mating parts in the final docking phase. A preliminary version of the algorithm was developed and field-tested on the Axel rover in the JPL Mars Yard. The algorithm achieved an 80% success rate in 40 experiments in both firm and loose soils and starting from up to 6 m away at up to 40 deg radial angle and 20 deg relative heading. The algorithm does not rely on an initial estimate of the relative pose. The preliminary results are promising and help retire the risk associated with the autonomous docking process enabling consideration in future martian and lunar missions.

Dynamics and stability of a tethered centrifuge in low earth orbit

Science.gov (United States)

Quadrelli, B. M.; Lorenzini, E. C.

1992-01-01

The three-dimensional attitude dynamics of a spaceborne tethered centrifuge for artificial gravity experiments in low earth orbit is analyzed using two different methods. First, the tethered centrifuge is modeled as a dumbbell with a straight viscoelastic tether, point tip-masses, and sophisticated environmental models such as nonspherical gravity, thermal perturbations, and a dynamic atmospheric model. The motion of the centrifuge during spin-up, de-spin, and steady-rotation is then simulated. Second, a continuum model of the tether is developed for analyzing the stability of lateral tether oscillations. Results indicate that the maximum fluctuation about the 1-g radial acceleration level is less than 0.001 g; the time required for spin-up and de-spin is less than one orbit; and lateral oscillations are stable for any practical values of the system parameters.

T-Rex: A Japanese Space Tether Experiment

Science.gov (United States)

Johnson, Les

2009-01-01

Electrodynamic tether (EDT) thrusters work by virtue of the force a magnetic field exerts on a wire carrying an electrical current. The force, which acts on any charged particle moving through a magnetic field (including the electrons moving in a current-carrying wire), were concisely expressed by Lorentz in 1895 in an equation that now bears his name. The force acts in a direction perpendicular to both the direction of current flow and the magnetic field vector. Electric motors make use of this force: a wire loop in a magnetic field is made to rotate by the torque the Lorentz Force exerts on it due to an alternating current in the loop times so as to keep the torque acting in the same sense. The motion of the loop is transmitted to a shaft, thus providing work. Although the working principle of EDT thrusters is not new, its application to space transportation may be significant. In essence, an EDT thruster is just a clever way of getting an electrical current to flow in a long orbiting wire (the tether) so that the Earth s magnetic field will accelerate the wire and, consequently the payload attached to the wire. The direction of current flow in the tether, either toward or away from the Earth along the local vertical, determines whether the magnetic force will raise or lower the orbit. The bias voltage of a vertically deployed metal tether, which results just from its orbital motion (assumed eastward) through Earth s magnetic field, is positive with respect to the ambient plasma at the top and negative at the bottom. This polarization is due to the action of the Lorentz force on the electrons in the tether. Thus, the natural current flow is the result of negative electrons being attracted to the upper end and then returned to the plasma at the lower end. The magnetic force in this case has a component opposite to the direction of motion, and thus leads to a lowering of the orbit and eventually to re-entry. In this generator mode of operation the Lorentz Force

Tethered Forth system for FPGA applications

Science.gov (United States)

Goździkowski, Paweł; Zabołotny, Wojciech M.

2013-10-01

This paper presents the tethered Forth system dedicated for testing and debugging of FPGA based electronic systems. Use of the Forth language allows to interactively develop and run complex testing or debugging routines. The solution is based on a small, 16-bit soft core CPU, used to implement the Forth Virtual Machine. Thanks to the use of the tethered Forth model it is possible to minimize usage of the internal RAM memory in the FPGA. The function of the intelligent terminal, which is an essential part of the tethered Forth system, may be fulfilled by the standard PC computer or by the smartphone. System is implemented in Python (the software for intelligent terminal), and in VHDL (the IP core for FPGA), so it can be easily ported to different hardware platforms. The connection between the terminal and FPGA may be established and disconnected many times without disturbing the state of the FPGA based system. The presented system has been verified in the hardware, and may be used as a tool for debugging, testing and even implementing of control algorithms for FPGA based systems.

Cycloid scanning for wide field optical coherence tomography endomicroscopy and angiography in vivo

Science.gov (United States)

Liang, Kaicheng; Wang, Zhao; Ahsen, Osman O.; Lee, Hsiang-Chieh; Potsaid, Benjamin M.; Jayaraman, Vijaysekhar; Cable, Alex; Mashimo, Hiroshi; Li, Xingde; Fujimoto, James G.

2018-01-01

Devices that perform wide field-of-view (FOV) precision optical scanning are important for endoscopic assessment and diagnosis of luminal organ disease such as in gastroenterology. Optical scanning for in vivo endoscopic imaging has traditionally relied on one or more proximal mechanical actuators, limiting scan accuracy and imaging speed. There is a need for rapid and precise two-dimensional (2D) microscanning technologies to enable the translation of benchtop scanning microscopies to in vivo endoscopic imaging. We demonstrate a new cycloid scanner in a tethered capsule for ultrahigh speed, side-viewing optical coherence tomography (OCT) endomicroscopy in vivo. The cycloid capsule incorporates two scanners: a piezoelectrically actuated resonant fiber scanner to perform a precision, small FOV, fast scan and a micromotor scanner to perform a wide FOV, slow scan. Together these scanners distally scan the beam circumferentially in a 2D cycloid pattern, generating an unwrapped 1 mm × 38 mm strip FOV. Sequential strip volumes can be acquired with proximal pullback to image centimeter-long regions. Using ultrahigh speed 1.3 μm wavelength swept-source OCT at a 1.17 MHz axial scan rate, we imaged the human rectum at 3 volumes/s. Each OCT strip volume had 166 × 2322 axial scans with 8.5 μm axial and 30 μm transverse resolution. We further demonstrate OCT angiography at 0.5 volumes/s, producing volumetric images of vasculature. In addition to OCT applications, cycloid scanning promises to enable precision 2D optical scanning for other imaging modalities, including fluorescence confocal and nonlinear microscopy. PMID:29682598

Learning characteristics of a space-time neural network as a tether skiprope observer

Science.gov (United States)

Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

1993-01-01

The Software Technology Laboratory at the Johnson Space Center is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

Clinical endoscopic management and outcome of post-endoscopic sphincterotomy bleeding.

Directory of Open Access Journals (Sweden)

Wei-Chen Lin

Full Text Available Post-endoscopic sphincterotomy bleeding is a common complication of biliary sphincterotomy, and the incidence varies from 1% to 48%. It can be challenging to localize the bleeder or to administer various interventions through a side-viewing endoscope. This study aimed to evaluate the risk factors of post-endoscopic sphincterotomy bleeding and the outcome of endoscopic intervention therapies. We retrospectively reviewed the records of 513 patients who underwent biliary sphincterotomy in Mackay Memorial Hospital between 2011 and 2016. The blood biochemistry, comorbidities, indication for sphincterotomy, severity of bleeding, endoscopic features of bleeder, and type of endoscopic therapy were analyzed. Post-endoscopic sphincterotomy bleeding occurred in 65 (12.6% patients. Forty-five patients had immediate bleeding and 20 patients had delayed bleeding. The multivariate analysis of risk factors associated with post-endoscopic sphincterotomy bleeding were liver cirrhosis (P = 0.029, end-stage renal disease (P = 0.038, previous antiplatelet drug use (P<0.001, and duodenal ulcer (P = 0.023. The complications of pancreatitis and cholangitis were higher in the bleeding group, with statistical significance. Delayed bleeding occurred within 1 to 7 days (mean, 2.5 days, and 60% (12/20 of the patients received endoscopic evaluation. In the delayed bleeding group, the successful hemostasis rate was 71.4% (5/7, and 65% (13/20 of the patients had ceased bleeding without endoscopic hemostasis therapy. Comparison of different therapeutic modalities showed that cholangitis was higher in patients who received epinephrine spray (P = 0.042 and pancreatitis was higher in patients who received epinephrine injection and electrocoagulation (P = 0.041 and P = 0.039 respectively. Clinically, post-endoscopic sphincterotomy bleeding and further endoscopic hemostasis therapy increase the complication rate of pancreatitis and cholangitis. Realizing the effectiveness of each

Trace gas measurements from tethered balloon platforms

Science.gov (United States)

Bandy, Alan R.; Bandy, Terese L.; Youngbluth, Otto; Owens, Thomas L.

1987-01-01

Instrumentation and chemical sampling and analysis procedures are described for making measurements of atmospheric carbon disulfide in the concentration range 1-1000 pptv from tethered balloon platforms. Results of a study on the CS2 composition of air downward of a saltwater marsh are reported. A method for obtaining the necessary data for solving the budget equations for surface fluxes, chemical formation rates and chemical destruction rates using data acquired from tethered balloon platforms is presented.

Transitions of tethered chain molecules under tension.

Science.gov (United States)

Luettmer-Strathmann, Jutta; Binder, Kurt

2014-09-21

An applied tension force changes the equilibrium conformations of a polymer chain tethered to a planar substrate and thus affects the adsorption transition as well as the coil-globule and crystallization transitions. Conversely, solvent quality and surface attraction are reflected in equilibrium force-extension curves that can be measured in experiments. To investigate these effects theoretically, we study tethered chains under tension with Wang-Landau simulations of a bond-fluctuation lattice model. Applying our model to pulling experiments on biological molecules we obtain a good description of experimental data in the intermediate force range, where universal features dominate and finite size effects are small. For tethered chains in poor solvent, we observe the predicted two-phase coexistence at transitions from the globule to stretched conformations and also discover direct transitions from crystalline to stretched conformations. A phase portrait for finite chains constructed by evaluating the density of states for a broad range of solvent conditions and tensions shows how increasing tension leads to a disappearance of the globular phase. For chains in good solvents tethered to hard and attractive surfaces we find the predicted scaling with the chain length in the low-force regime and show that our results are well described by an analytical, independent-bond approximation for the bond-fluctuation model for the highest tensions. Finally, for a hard or slightly attractive surface the stretching of a tethered chain is a conformational change that does not correspond to a phase transition. However, when the surface attraction is sufficient to adsorb a chain it will undergo a desorption transition at a critical value of the applied force. Our results for force-induced desorption show the transition to be discontinuous with partially desorbed conformations in the coexistence region.

Dynamic analysis of the tether transportation system using absolute nodal coordinate formulation

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Sun, Xin; Xu, Ming; Zhong, Rui

2017-10-01

Long space tethers are becoming a rising concern as an alternate way for transportation in space. It benefits from fuel economizing. This paper focuses on the dynamics of the tether transportation system, which consists of two end satellites connected by a flexible tether, and a movable vehicle driven by the actuator carried by itself. The Absolute Nodal Coordinate Formulation is applied to the establishment of the equation of motion, so that the influence caused by the distributed mass and elasticity of the tether is introduced. Moreover, an approximated method for accelerating the calculation of the generalized gravitational forces on the tether is proposed by substituting the volume integral every step into summation of finite terms. Afterwards, dynamic evolutions of such a system in different configurations are illustrated using numerical simulations. The deflection of the tether and the trajectory of the crawler during the transportation is investigated. Finally, the effect on the orbit of the system due to the crawler is revealed.

Thrust Control During Towing of Space Debris using an Elastic Tether

Directory of Open Access Journals (Sweden)

A. D. Ledkov

2014-01-01

Full Text Available The paper considers a maneuver for deorbiting the large space debris using an active spacecraft connected with the debris by an elastic tether. Tether slacking during the maneuver can lead to the tether rupture, kinking, and winding on the descending object. Therefore it is important to prevent slacking. The objective of this work is to find the law of thrust force control of the active spacecraft to ensure a continuously strained tether during the maneuver.Using Lagrange formalism a mathematical model to describe the system plane motion is developed. This model considers the active spacecraft as a mass point, the space debris as a rigid body, and the tether as a weightless elastic rod. A thrust force is directed along the local horizon of the spacecraft. Linearization of nonlinear differential equation describing longitudinal oscillations of the tether length is performed. Its phase portrait is analyzed. An approximate expression describing the position of the center on the phase portrait is obtained. A time-optimal control with full feedback to ensure that the tether is in the strained state is found by solving the Bellman equation. To use the obtained optimal law it is necessary to set the measuring equipment on the spacecraft, which is capable of accurate measuring a distance to the space debris and its relative velocity. An alternative control law, which is simpler in terms of the practical implementation, is proposed. As an example, the descent from an orbit of nonfunctioning Soviet satellite Meteor-2 is considered. It is shown that both proposed laws provide continuous strain of the tether during deorbiting of the satellite. Moreover, slack does not occur even at the first period of oscillation of the tether length. It is shown that the use of the proposed control laws leads to slight increase of deorbiting time as compared to the case of using the constant thrust.The results can be used to develop the control systems of small spacecrafts

Scoping the scope: endoscopic evaluation of endoscope working channels with a new high-resolution inspection endoscope (with video).

Science.gov (United States)

Barakat, Monique T; Girotra, Mohit; Huang, Robert J; Banerjee, Subhas

2018-02-06

Outbreaks of transmission of infection related to endoscopy despite reported adherence to reprocessing guidelines warrant scrutiny of all potential contributing factors. Recent reports from ambulatory surgery centers indicated widespread significant occult damage within endoscope working channels, raising concerns regarding the potential detrimental impact of this damage on the adequacy of endoscope reprocessing. We inspected working channels of all 68 endoscopes at our academic institution using a novel flexible inspection endoscope. Inspections were recorded and videos reviewed by 3 investigators to evaluate and rate channel damage and/or debris. Working channel rinsates were obtained from all endoscopes, and adenosine triphosphate (ATP) bioluminescence was measured. Overall endoscope working channel damage was rated as minimal and/or mild and was consistent with expected wear and tear (median 1.59 on our 5-point scale). Our predominant findings included superficial scratches (98.5%) and scratches with adherent peel (76.5%). No channel perforations, stains, or burns were detected. The extent of damage was not predicted by endoscope age. Minor punctate debris was common, and a few small drops of fluid were noted in 42.6% of endoscopes after reprocessing and drying. The presence of residual fluid predicted higher ATP bioluminescence values. The presence of visualized working channel damage or debris was not associated with elevated ATP bioluminescence values. The flexible inspection endoscope enables high-resolution imaging of endoscope working channels and offers endoscopy units an additional modality for endoscope surveillance, potentially complementing bacterial cultures and ATP values. Our study, conducted in a busy academic endoscopy unit, indicated predominately mild damage to endoscope working channels, which did not correlate with elevated ATP values. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights

Sonography compared with MR imaging in the evaluation of card tethering following myelomeningocele repair

International Nuclear Information System (INIS)

Newman, B.; Bowen, A.; Albright, L.

1989-01-01

This paper reports on MR imaging and videotaped US spine examinations to evaluate cord tethering were retrospectively compared in 12 children with prior myelomeningocele repair and correlated with clinical and surgical findings. Although US did not delineate normal or abnormal anatomy as well as MR imaging, both types of studies confirmed the presence of tethering in 10 patients. One child with a normal US examination and abnormal MR images had tethering confirmed surgically. A second child had a US study suggestive of tethering with equivocal MR images. Postoperative studies in eight patients correlated less well; US suggested persistent tethering in five patients and MR imaging indicated tethering in two

Effects of food on a gastrically degraded drug: azithromycin fast-dissolving gelatin capsules and HPMC capsules.

Science.gov (United States)

Curatolo, William; Liu, Ping; Johnson, Barbara A; Hausberger, Angela; Quan, Ernest; Vendola, Thomas; Vatsaraj, Neha; Foulds, George; Vincent, John; Chandra, Richa

2011-07-01

Commercial azithromycin gelatin capsules (Zithromax®) are known to be bioequivalent to commercial azithromycin tablets (Zithromax®) when dosed in the fasted state. These capsules exhibit a reduced bioavailability when dosed in the fed state, while tablets do not. This gelatin capsule negative food effect was previously proposed to be due to slow and/or delayed capsule disintegration in the fed stomach, resulting in extended exposure of the drug to gastric acid, leading to degradation to des-cladinose-azithromycin (DCA). Azithromycin gelatin capsules were formulated with "superdisintegrants" to provide fast-dissolving capsules, and HPMC capsule shells were substituted for gelatin capsule shells, in an effort to eliminate the food effect. Healthy volunteers were dosed with these dosage forms under fasted and fed conditions; pharmacokinetics were evaluated. DCA pharmacokinetics were also evaluated for the HPMC capsule subjects. In vitro disintegration of azithromycin HPMC capsules in media containing food was evaluated and compared with commercial tablets and commercial gelatin capsules. When the two fast-dissolving capsule formulations were dosed to fed subjects, the azithromycin AUC was 38.9% and 52.1% lower than after fasted-state dosing. When HPMC capsules were dosed to fed subjects, the azithromycin AUC was 65.5% lower than after fasted-state dosing. For HPMC capsules, the absolute fasting-state to fed-state decrease in azithromycin AUC (on a molar basis) was similar to the increase in DCA AUC. In vitro capsule disintegration studies revealed extended disintegration times for commercial azithromycin gelatin capsules and HPMC capsules in media containing the liquid foods milk and Ensure®. Interaction of azithromycin gelatin and HPMC capsules with food results in slowed disintegration in vitro and decreased bioavailability in vivo. Concurrent measurement of serum azithromycin and the acid-degradation product DCA demonstrates that the loss of azithromycin

High-field MR imaging of tethered cord

International Nuclear Information System (INIS)

Sigal, R.; Bicetre, L.; Blass, C.; Doyon, D.; Pariente, D.

1986-01-01

MR imaging examinations of 12 patients with tethered cord syndrome have been performed on a 1.5-T MR imaging unit. Patients ranged in age from 3 to 60 years. MR findings were compared with those of myelography and metrizamide CT in all cases. Five patients underwent surgical control and postoperative MR imaging. Sagittal and axial sections were obtained using a spin-echo multisection, multiecho technique. T1-axial weighted images (SE 600/25) were sufficient to locate the position of the tip of the conus. They also allowed identification of extraspinal and intraspinal lipomas and clear-cut demarcation form associated tethered cord. Drawbacks of MR imaging were lack of precise depiction of the bone structures and the fact that clear identification of abnormal roots was problematic. The craniovertebral junction was always checked; two asymptomatic Chiari malformations were visualized. This study leads the authors to conclude that MR imaging should be used as the examination of first choice in the management of tethered cord syndrome

The investigation of tethered satellite system dynamics

Science.gov (United States)

Lorenzini, E. C.

1986-01-01

The analysis of the rotational dynamics of the satellite was focused on the rotational amplitude increase of the satellite, with respect to the tether, during retrieval. The dependence of the rotational amplitude upon the tether tension variation to the power 1/4 was thoroughly investigated. The damping of rotational oscillations achievable by reel control was also quantified while an alternative solution that makes use of a lever arm attached with a universal joint to the satellite was proposed. Comparison simulations between the Smithsonian Astrophysical Observatory and the Martin Marietta (MMA) computer code of reteival maneuvers were also carried out. The agreement between the two, completely independent, codes was extremely close, demonstrating the reliability of the models. The slack tether dynamics during reel jams was analytically investigated in order to identify the limits of applicability of the SLACK3 computer code to this particular case. Test runs with SLACK3 were also carried out.

Vesicle fusion observed by content transfer across a tethered lipid bilayer.

Science.gov (United States)

Rawle, Robert J; van Lengerich, Bettina; Chung, Minsub; Bendix, Poul Martin; Boxer, Steven G

2011-10-19

Synaptic transmission is achieved by exocytosis of small, synaptic vesicles containing neurotransmitters across the plasma membrane. Here, we use a DNA-tethered freestanding bilayer as a target architecture that allows observation of content transfer of individual vesicles across the tethered planar bilayer. Tethering and fusion are mediated by hybridization of complementary DNA-lipid conjugates inserted into the two membranes, and content transfer is monitored by the dequenching of an aqueous content dye. By analyzing the diffusion profile of the aqueous dye after vesicle fusion, we are able to distinguish content transfer across the tethered bilayer patch from vesicle leakage above the patch. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Hierarchical Structure in Semicrystalline Polymers Tethered to Nanospheres

KAUST Repository

Kim, Sung A

2014-01-28

We report on structural and dynamic transitions of polymers tethered to nanoparticles. In particular, we use X-ray diffraction, vibrational spectroscopy, and thermal measurements to investigate multiscale structure and dynamic transitions of poly(ethylene glycol) (PEG) chains densely grafted to SiO2 nanoparticles. The approach used for synthesizing these hybrid particles leads to homogeneous SiO2-PEG composites with polymer grafting densities as high as 1.5 chains/nm2, which allows the hybrid materials to exist as self-suspended suspensions with distinct hierarchical structure and thermal properties. On angstrom and nanometer length scales, the tethered PEG chains exhibit more dominant TTG conformations and helix unit cell structure, in comparison to the untethered polymer. The nanoparticle tethered PEG chains are also reported to form extended crystallites on tens of nanometers length scales and to exhibit more stable crystalline structure on small dimensions. On length scales comparable to the size of each hybrid SiO 2-PEG unit, the materials are amorphous presumably as a result of the difficulty fitting the nanoparticle anchors into the PEG crystal lattice. This structural change produces large effects on the thermal transitions of PEG molecules tethered to nanoparticles. © 2014 American Chemical Society.

NASA Langley Research Center tethered balloon systems

Science.gov (United States)

Owens, Thomas L.; Storey, Richard W.; Youngbluth, Otto

1987-01-01

The NASA Langley Research Center tethered balloon system operations are covered in this report for the period of 1979 through 1983. Meteorological data, ozone concentrations, and other data were obtained from in situ measurements. The large tethered balloon had a lifting capability of 30 kilograms to 2500 meters. The report includes descriptions of the various components of the balloon systems such as the balloons, the sensors, the electronics, and the hardware. Several photographs of the system are included as well as a list of projects including the types of data gathered.

Tethered catalysts for the hydration of carbon dioxide

Science.gov (United States)

Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

2014-11-04

A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

Numerical Simulation of Tethered Underwater Kites for Power Generation

Science.gov (United States)

Ghasemi, Amirmahdi; Olinger, David; Tryggvason, Gretar

2015-11-01

An emerging renewable energy technology, tethered undersea kites (TUSK), which is used to extract hydrokinetic energy from ocean and tidal currents, is studied. TUSK systems consist of a rigid-winged ``kite,'' or glider, moving in an ocean current which is connected by tethers to a floating buoy on the ocean surface. The TUSK kite is a current speed enhancement device since the kite can move in high-speed, cross-current motion at 4-6 times the current velocity, thus producing more power than conventional marine turbines. A computational simulation is developed to simulate the dynamic motion of an underwater kite and extendable tether. A two-step projection method within a finite volume formulation, along with an Open MP acceleration method, is employed to solve the Navier-Stokes equations. An immersed boundary method is incorporated to model the fluid-structure interaction of the rigid kite (with NACA 0012 airfoil shape in 2D and NACA 0021 airfoil shape in 3D simulations) and the fluid flow. PID control methods are used to adjust the kite angle of attack during power (tether reel-out) and retraction (reel-in) phases. Two baseline simulations (for kite motions in two and three dimensions) are studied, and system power output, flow field vorticity, tether tension, and hydrodynamic coefficients (lift and drag) for the kite are determined. The simulated power output shows good agreement with established theoretical results for a kite moving in two-dimensions.

Biomimicry enhances sequential reactions of tethered glycolytic enzymes, TPI and GAPDHS.

Directory of Open Access Journals (Sweden)

Chinatsu Mukai

Full Text Available Maintaining activity of enzymes tethered to solid interfaces remains a major challenge in developing hybrid organic-inorganic devices. In nature, mammalian spermatozoa have overcome this design challenge by having glycolytic enzymes with specialized targeting domains that enable them to function while tethered to a cytoskeletal element. As a step toward designing a hybrid organic-inorganic ATP-generating system, we implemented a biomimetic site-specific immobilization strategy to tether two glycolytic enzymes representing different functional enzyme families: triose phosphoisomerase (TPI; an isomerase and glyceraldehyde 3-phosphate dehydrogenase (GAPDHS; an oxidoreductase. We then evaluated the activities of these enzymes in comparison to when they were tethered via classical carboxyl-amine crosslinking. Both enzymes show similar surface binding regardless of immobilization method. Remarkably, specific activities for both enzymes were significantly higher when tethered using the biomimetic, site-specific immobilization approach. Using this biomimetic approach, we tethered both enzymes to a single surface and demonstrated their function in series in both forward and reverse directions. Again, the activities in series were significantly higher in both directions when the enzymes were coupled using this biomimetic approach versus carboxyl-amine binding. Our results suggest that biomimetic, site-specific immobilization can provide important functional advantages over chemically specific, but non-oriented attachment, an important strategic insight given the growing interest in recapitulating entire biological pathways on hybrid organic-inorganic devices.

Biomimicry enhances sequential reactions of tethered glycolytic enzymes, TPI and GAPDHS.

Science.gov (United States)

Mukai, Chinatsu; Gao, Lizeng; Bergkvist, Magnus; Nelson, Jacquelyn L; Hinchman, Meleana M; Travis, Alexander J

2013-01-01

Maintaining activity of enzymes tethered to solid interfaces remains a major challenge in developing hybrid organic-inorganic devices. In nature, mammalian spermatozoa have overcome this design challenge by having glycolytic enzymes with specialized targeting domains that enable them to function while tethered to a cytoskeletal element. As a step toward designing a hybrid organic-inorganic ATP-generating system, we implemented a biomimetic site-specific immobilization strategy to tether two glycolytic enzymes representing different functional enzyme families: triose phosphoisomerase (TPI; an isomerase) and glyceraldehyde 3-phosphate dehydrogenase (GAPDHS; an oxidoreductase). We then evaluated the activities of these enzymes in comparison to when they were tethered via classical carboxyl-amine crosslinking. Both enzymes show similar surface binding regardless of immobilization method. Remarkably, specific activities for both enzymes were significantly higher when tethered using the biomimetic, site-specific immobilization approach. Using this biomimetic approach, we tethered both enzymes to a single surface and demonstrated their function in series in both forward and reverse directions. Again, the activities in series were significantly higher in both directions when the enzymes were coupled using this biomimetic approach versus carboxyl-amine binding. Our results suggest that biomimetic, site-specific immobilization can provide important functional advantages over chemically specific, but non-oriented attachment, an important strategic insight given the growing interest in recapitulating entire biological pathways on hybrid organic-inorganic devices.

Tethered Ozonesonde Measurements During FRAPPE July-August 2014

Science.gov (United States)

Oltmans, S. J.; Johnson, B.; Sterling, C. W.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Wendell, J.; Schnell, R. C.; McClure-Begley, A.; Thompson, A. M.

2015-12-01

O3 and temperature profiles were measured from tethered ozonesondes from surface to 400 m above ground level on 9 days during the summer of 2014 Colorado Front Range Air Pollution and Photochemistry Experiment (FRAPPE). The portable tethered ozonesonde system was set up at one of 3 sites located next to a Colorado Department of Public Health and Environment surface monitoring station. The day and site chosen were based on the previous day O3 and weather forecast. Measurements typically began at 8:30 AM and ended at 4:30 PM, averaging 40 profiles in one day. The ozonesonde when sampling at the surface consistently read within 0-3 ppbv of the surface monitor at each of the sites with a typical daytime range of 20-90 ppbv. The hourly values were averaged at 50 meter intervals showing O3 production rates were consistently around 8 ppbv per hour from 50 to 300 meters above ground level. On sunny, light wind days the O3 mixing ratio reached a maximum of 80-90 ppbv between 14:00 and 15:00 local time. The generally constant mixing ratio with height and highest mixing ratios above the surface indicate that photochemical O3 production was taking place throughout the profile. Continuous O3 profiles from a tall tower (5 and 300 m) and daily ozonesondes tracked O3 variability through the experiment. High O3 at each site was associated with different local wind directions. At Ft. Collins winds were generally out of the southeast, at Chatfield from the northeast, and at City Park Golf Course more variable. The tether system was developed at NOAA/ESRL to provide a cost effective method to measure O3 profiles on a continuous basis. The tether system consisted of a deep sea fishing pole, electric motor driving the reel with light-weight fishing line attached to the balloon ozonesonde, a tether control box, and laptop. The in house software package monitored data and controlled the tether speed and turn-around point based on real time GPS altitude from the transmitting radiosonde.

An Effective Approach Control Scheme for the Tethered Space Robot System

Directory of Open Access Journals (Sweden)

Zhongjie Meng

2014-09-01

Full Text Available The tethered space robot system (TSR, which is composed of a platform, a gripper and a space tether, has great potential in future space missions. Given the relative motion among the platform, tether, gripper and the target, an integrated approach model is derived. Then, a novel coordinated approach control scheme is presented, in which the tether tension, thrusters and the reaction wheel are all utilized. It contains the open-loop trajectory optimization, the feedback trajectory control and attitude control. The numerical simulation results show that the rendezvous between TSR and the target can be realized by the proposed coordinated control scheme, and the propellant consumption is efficiently reduced. Moreover, the control scheme performs well in the presence of the initial state's perturbations, actuator characteristics and sensor errors.

Modelling a tethered mammalian sperm cell undergoing hyperactivation

KAUST Repository

Curtis, M.P.

2012-09-01

The beat patterns of mammalian sperm flagella can be categorised into two different types. The first involves symmetric waves propagating down the flagellum with a net linear propulsion of the sperm cell. The second, hyperactive, waveform is classified by vigorous asymmetric waves of higher amplitude, lower wavenumber and frequency propagating down the flagellum resulting in highly curved trajectories. The latter beat pattern is part of the capacitation process whereby sperm prepare for the prospective penetration of the zona pellucida and fusion with the egg. Hyperactivation is often observed to initiate as sperm escape from epithelial and ciliary bindings formed within the isthmic regions of the female oviducts, leading to a conjecture in the literature that this waveform is mechanically important for sperm escape. Hence, we explore the mechanical effects of hyperactivation on a tethered sperm, focussing on a Newtonian fluid. Using a resistive force theory model we demonstrate that hyperactivation can indeed generate forces that pull the sperm away from a tethering point and consequently a hyperactivated sperm cell bound to an epithelial surface need not always be pushed by its flagellum. More generally, directions of the forces generated by tethered flagella are insensitive to reductions in beat frequency and the detailed flagellar responses depend on the nature of the binding at the tethering point. Furthermore, waveform asymmetry and amplitude increases enhance the tendency for a tethered flagellum to start tugging on its binding. The same is generally predicted to be true for reductions in the wavenumber of the flagellum beat, but not universally so, emphasising the dynamical complexity of flagellar force generation. Finally, qualitative observations drawn from experimental data of human sperm bound to excised female reproductive tract are also presented and are found to be consistent with the theoretical predictions. © 2012 Elsevier Ltd.

Modelling a tethered mammalian sperm cell undergoing hyperactivation

KAUST Repository

Curtis, M.P.; Kirkman-Brown, J.C.; Connolly, T.J.; Gaffney, E.A.

2012-01-01

The beat patterns of mammalian sperm flagella can be categorised into two different types. The first involves symmetric waves propagating down the flagellum with a net linear propulsion of the sperm cell. The second, hyperactive, waveform is classified by vigorous asymmetric waves of higher amplitude, lower wavenumber and frequency propagating down the flagellum resulting in highly curved trajectories. The latter beat pattern is part of the capacitation process whereby sperm prepare for the prospective penetration of the zona pellucida and fusion with the egg. Hyperactivation is often observed to initiate as sperm escape from epithelial and ciliary bindings formed within the isthmic regions of the female oviducts, leading to a conjecture in the literature that this waveform is mechanically important for sperm escape. Hence, we explore the mechanical effects of hyperactivation on a tethered sperm, focussing on a Newtonian fluid. Using a resistive force theory model we demonstrate that hyperactivation can indeed generate forces that pull the sperm away from a tethering point and consequently a hyperactivated sperm cell bound to an epithelial surface need not always be pushed by its flagellum. More generally, directions of the forces generated by tethered flagella are insensitive to reductions in beat frequency and the detailed flagellar responses depend on the nature of the binding at the tethering point. Furthermore, waveform asymmetry and amplitude increases enhance the tendency for a tethered flagellum to start tugging on its binding. The same is generally predicted to be true for reductions in the wavenumber of the flagellum beat, but not universally so, emphasising the dynamical complexity of flagellar force generation. Finally, qualitative observations drawn from experimental data of human sperm bound to excised female reproductive tract are also presented and are found to be consistent with the theoretical predictions. © 2012 Elsevier Ltd.

Endoscopic root canal treatment.

Science.gov (United States)

Moshonov, Joshua; Michaeli, Eli; Nahlieli, Oded

2009-10-01

To describe an innovative endoscopic technique for root canal treatment. Root canal treatment was performed on 12 patients (15 teeth), using a newly developed endoscope (Sialotechnology), which combines an endoscope, irrigation, and a surgical microinstrument channel. Endoscopic root canal treatment of all 15 teeth was successful with complete resolution of all symptoms (6-month follow-up). The novel endoscope used in this study accurately identified all microstructures and simplified root canal treatment. The endoscope may be considered for use not only for preoperative observation and diagnosis but also for active endodontic treatment.

Tethered elevator and platforms as space station facilities: Systems studies and demonstrative experiments

Science.gov (United States)

1986-01-01

Several key concepts of the science and applications tethered platforms were studied. Some conclusions reached are herein listed. Tether elevator and platform could improve the space station scientific and applicative capabilities. The space elevator presents unique characteristics as microgravity facility and as a tethered platform servicing vehicle. Pointing platforms could represent a new kind of observation facility for large class of payloads. The dynamical, control and technological complexity of these concepts advised demonstrative experiments. The on-going tethered satellite system offers the opportunity to perform such experiments. And feasibility studies are in progress.

Status of the material capsule irradiation and the development of the new capsule technology in HANARO

International Nuclear Information System (INIS)

Choo, Kee-Nam; Kang, Young-Hwan; Choi, Myoung-Hwan; Cho, Man-Soon; Kim, Bong-Goo

2006-01-01

A material capsule system including a main capsule, fixing, control, cutting, and transport systems was developed for an irradiation test of non-fissile materials in HANARO. 14 irradiation capsules (12 instrumented and 2 non-instrumented capsules) have been designed, fabricated and successfully irradiated in the HANARO CT and IR test holes since 1995. The capsules were mainly designed for an irradiation of the RPV (Reactor Pressure Vessel), reactor core materials, and Zr-based alloys. Most capsules were made for KAERI material research projects, but 5 capsules were made as a part of national projects for the promotion of the HANARO utilization for universities. Based on the accumulated irradiation experience and the user's sophisticated requirements, development of new instrumented capsule technologies for a more precise control of the irradiation temperature and fluence of a specimen irrespective of the reactor operation has been performed in HANARO. (author)

Forces, energetics, and dynamics of conjugated-carbon ring tethers adhered to CNTs: a computational investigation.

Science.gov (United States)

Filla, Nicholas; Ramasamy, Ramaraja; Wang, Xianqiao

2018-04-25

The strength and nature of the interactions between carbon nanotubes (CNTs) and molecular tethers plays a vital role in technology such as CNT-enzyme sensors. Tethers that attach noncovalently to CNTs are ideal for retaining the electrical properties of the CNTs since they do not degrade the CNT surface and effect its electrical conductivity. However, leaching due to weak CNT-tether attachment is very common when using noncovalent tethers, and this has limited their use in commercial products including biosensors. Thus, understanding the fundamental mechanics governing the strength of CNT-tether adhesion is crucial for the design of highly sensitive, viable sensors. Here, we computationally investigate the adhesion strength of CNT-tether complexes with 8 different tethering molecules designed to adhere noncovalently to the CNT surface. We study the effects of CNT diameter, CNT chirality, and the size/geometry of the tethering molecule on the adhesion energy and force. Our results show an asymptotic relationship between adhesion strength and CNT diameter. Calculations show that noncovalent tethers tested here can reach adhesion forces and energies that are up to 21% and 54% of the strength of the carbon-carbon single bond force and bond energy respectively. We anticipate our results will help guide CNT-enzyme sensor design to produce sensors with high sensitivity and minimal leaching.

Novel roaming and stationary tethered aerial robots for continuous mobile missions in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Gu, Beom W.; Choi, Su Y.; Rim, Chun T. [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Choi, Young Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cai, Guowei; Seneviratne, Lakmal [Dept. of Aerospace Engineering, Khalifa University, Abu Dhabi (United Arab Emirates)

2016-08-15

In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

Novel Roaming and Stationary Tethered Aerial Robots for Continuous Mobile Missions in Nuclear Power Plants

Directory of Open Access Journals (Sweden)

Beom W. Gu

2016-08-01

Full Text Available In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs for radioactive material sampling and stationary tethered aerial robots (STARs for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

Electron Emitter for small-size Electrodynamic Space Tether using MEMS Technology

DEFF Research Database (Denmark)

Fleron, René A. W.; Blanke, Mogens

2004-01-01

Adjustment of the orbit of a spacecraft using the forces created by an electro-dynamic space-tether has been shown as a theoretic possibility in recent literature. Practical implementation is being pursued for larger scale missions where a hot filament device controls electron emission...... and the current flowing in the electrodynamic space tether. Applications to small spacecraft, or space debris in the 1–10 kg range, possess difficulties with electron emission technology, as low power emitting devices are needed. This paper addresses the system concepts of a small spacecraft electrodynamic tether...... system with focus on electron emitter design and manufacture using micro-electro-mechanical- system (MEMS) technology. The paper addresses the system concepts of a small size electrodynamic tether mission and shows a novel electron emitter for the 1-2 mA range where altitude can be effectively affected...

Summary Report for Capsule Dry Storage Project

Energy Technology Data Exchange (ETDEWEB)

JOSEPHSON, W S

2003-09-04

There are 1.936 cesium (Cs) and strontium (Sr) capsules stored in pools at the Waste Encapsulation and Storage Facility (WESF). These capsules will be moved to dry storage on the Hanford Site as an interim measure to reduce risk. The Cs/Sr Capsule Dry Storage Project (CDSP) is conducted under the assumption the capsules will eventually be moved to the repository at Yucca Mountain, and the design criteria include requirements that will facilitate acceptance at the repository. The storage system must also permit retrieval of capsules in the event vitrification of the capsule contents is pursued. A cut away drawing of a typical cesium chloride (CsCI) capsule and the capsule property and geometry information are provided in Figure 1.1. Strontium fluoride (SrF{sub 2}) capsules are similar in design to CsCl capsules. Further details of capsule design, current state, and reference information are given later in this report and its references. Capsule production and life history is covered in WMP-16938, Capsule Characterization Report for Capsule Dry Storage Project, and is briefly summarized in Section 5.2 of this report.

Results from a tethered rocket experiment (Charge-2)

Science.gov (United States)

Kawashima, N.; Sasaki, S.; Oyama, K. I.; Hirao, K.; Obayashi, T.; Raitt, W. J.; White, A. B.; Williamson, P. R.; Banks, P. M.; Sharp, W. F.

A tethered payload experiment (Charge-2) was carried out as an international program between Japan and the USA using a NASA sounding rocket at White Sands Missile Range. The objective of the experiment was to perform a new type of active experiment in space by injecting an electron beam from a mother-daughter rocket system connected with a long tether wire. The electron beam with voltage and current up to 1 kV and 80 mA (nominal) was injected from the mother payload. An insulated conductive wire of 426 m length connected the two payloads, the longest tether system flown so far. The electron gun system and diagnostic instruments (plasma, optical, particle and wave) functioned correctly throughout the flight. The potential rise of the mother payload during the electron beam emission was measured with respect to the daughter payload. The beam trajectory was detected by a camera onboard the mother rocket. Wave generation and current induction in the wire during the beam emission were also studied.

Analytical Model for the Probability Characteristics of a Crack Penetrating Capsules in Capsule-Based Self-Healing Cementitious Materials

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Zhong LV

2017-08-01

Full Text Available Autonomous crack healing using pre-embedded capsules containing healing agent is becoming a promising approach to restore the strength of damaged structures. In addition to the material properties, the size and volume fraction of capsules influence crack healing in the matrix. Understanding the crack and capsule interaction is critical in the development and design of structures made of capsule-based self-healing materials. Continuing our previous study, in this contribution a more practical rupturing mode of capsules characterizing the rupturing manner of capsules fractured by cracks in cementitious materials is presented, i.e., penetrating mode. With the underlying assumption that a crack penetrating capsules undoubtedly leads to crack healing, geometrical probability theory is employed to develop the quantitative relationship between crack size and capsule size, capsule concentration in capsule-based self-healing virtual cementitious material. Moreover, an analytical expression of probability of a crack penetrating with randomly dispersed capsules is developed in two-dimensional material matrix setup. The influences of the induced rupturing modes of capsules embedded on the self-healing efficiency are analyzed. Much attention is paid to compare the penetrating probability and the hitting probability, in order to assist the designer to make a choice of the optimal rupturing modes of capsules embedded. The accuracy of results of the theoretical model is also compared with Monte-Carlo numerical analysis of crack interacting with capsules. It shows that the developed probability characteristics of a crack interaction with capsules for different rupturing modes is helpful to provide guidelines for designer working with capsule-based self-healing cementitious materials.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16888

Polydopamine-coated capsules

Science.gov (United States)

White, Scott R.; Sottos, Nancy R.; Kang, Sen; Baginska, Marta B.

2018-04-17

One aspect of the invention is a polymer material comprising a capsule coated with PDA. In certain embodiments, the capsule encapsulates a functional agent. The encapsulated functional agent may be an indicating agent, healing agent, protecting agent, pharmaceutical drug, food additive, or a combination thereof.

Recurrent Lower Gastrointestinal Bleeding: Ileal GIST Diagnosed by Video Capsule Endoscopy—A Case Report and Literature Review

Directory of Open Access Journals (Sweden)

Jie Ling

2013-01-01

Full Text Available Introduction. Gastrointestinal stromal tumor (GIST in the ileum is an extremely rare cause of recurrent lower gastrointestinal bleeding (GIB. Case Report. An 89-year-old man was admitted with melana. He had extensive PMH of CAD post-CABG/AICD, AAA repair, chronic anemia, myelodysplastic syndrome, lung cancer after resection, and recurrent GIB. Prior EGDs, colonoscopies, and upper device-assisted enteroscopy showed duodenal ulcer, A-V malformation s/p cauterization, and angioectasia. On admission, Hb was 6.0 g/dL. An endoscopic capsule study showed an ulcerated tumor in the ileum. CT showed no distant metastasis. The lesion was resected successfully and confirmed as a high-grade GIST. The patient was discharged with no further bleeding. Discussion. Early diagnosis for patients with ileal GIST is often challenging. Video capsule endoscopy and double balloon enteroscopy could be useful diagnostic tools. Surgical removal is the first line for a resectable GIST. Imatinib has become the standard therapy. Conclusion. This is a unique case of an ileal GIST in a patient with recurrent GIB which was diagnosed by video capsule. Complicated medical comorbidities often lead to a significant delay in diagnosis. Therefore, we recommend that if GIB does not resolve after appropriate treatments for known causes, the alternative diagnosis for occult GIB must be considered, including malignancy such as GIST.

Long-term evaluation of intraoperative neurophysiological monitoring-assisted tethered cord surgery

NARCIS (Netherlands)

Dulfer, S E; Drost, G; Lange, F; Journee, H L; Wapstra, F H; Hoving, E W

2017-01-01

PURPOSE: Patients with tethered spinal cord have been investigated for short-term effects after tethered spinal cord surgery in the past. However, little is known about the long-term effects in this patient group. In this retrospective, longitudinal, observational study, a patient sample of a

Self-assembled tethered bimolecular lipid membranes.

Science.gov (United States)

Sinner, Eva-Kathrin; Ritz, Sandra; Naumann, Renate; Schiller, Stefan; Knoll, Wolfgang

2009-01-01

This chapter describes some of the strategies developed in our group for designing, constructing and structurally and functionally characterizing tethered bimolecular lipid membranes (tBLM). We introduce this platform as a novel model membrane system that complements the existing ones, for example, Langmuir monolayers, vesicular liposomal dispersions and bimolecular ("black") lipid membranes. Moreover, it offers the additional advantage of allowing for studies of the influence of membrane structure and order on the function of integral proteins, for example, on how the composition and organization of lipids in a mixed membrane influence the ion translocation activity of integral channel proteins. The first strategy that we introduce concerns the preparation of tethered monolayers by the self-assembly of telechelics. Their molecular architecture with a headgroup, a spacer unit (the "tether") and the amphiphile that mimics the lipid molecule allows them to bind specifically to the solid support thus forming the proximal layer of the final architecture. After fusion of vesicles that could contain reconstituted proteins from a liposomal dispersion in contact to this monolayer the tethered bimolecular lipid membrane is obtained. This can then be characterized by a broad range of surface analytical techniques, including surface plasmon spectroscopies, the quartz crystal microbalance, fluorescence and IR spectroscopies, and electrochemical techniques, to mention a few. It is shown that this concept allows for the construction of tethered lipid bilayers with outstanding electrical properties including resistivities in excess of 10 MOmega cm2. A modified strategy uses the assembly of peptides as spacers that couple covalently via their engineered sulfhydryl or lipoic acid groups at the N-terminus to the employed gold substrate, while their C-terminus is being activated afterward for the coupling of, for example, dimyristoylphosphatidylethanol amine (DMPE) lipid molecules

Robot-assisted endoscope guidance versus manual endoscope guidance in functional endonasal sinus surgery (FESS).

Science.gov (United States)

Eichhorn, Klaus Wolfgang; Westphal, Ralf; Rilk, Markus; Last, Carsten; Bootz, Friedrich; Wahl, Friedrich; Jakob, Mark; Send, Thorsten

2017-10-01

Having one hand occupied with the endoscope is the major disadvantage for the surgeon when it comes to functional endoscopic sinus surgery (FESS). Only the other hand is free to use the surgical instruments. Tiredness or frequent instrument changes can thus lead to shaky endoscopic images. We collected the pose data (position and orientation) of the rigid 0° endoscope and all the instruments used in 16 FESS procedures with manual endoscope guidance as well as robot-assisted endoscope guidance. In combination with the DICOM CT data, we tracked the endoscope poses and workspaces using self-developed tracking markers. All surgeries were performed once with the robot and once with the surgeon holding the endoscope. Looking at the durations required, we observed a decrease in the operating time because one surgeon doing all the procedures and so a learning curve occurred what we expected. The visual inspection of the specimens showed no damages to any of the structures outside the paranasal sinuses. Robot-assisted endoscope guidance in sinus surgery is possible. Further CT data, however, are desirable for the surgical analysis of a tracker-based navigation within the anatomic borders. Our marker-based tracking of the endoscope as well as the instruments makes an automated endoscope guidance feasible. On the subjective side, we see that RASS brings a relief for the surgeon.

Two-Way Tether Gun

Science.gov (United States)

Sanger, George F.

1994-01-01

Safety-tether device enables crewmembers on spacecraft to retrieve crewmember drifting away from spacecraft. Alternatively, drifting crewmember who carries device uses it to grasp and return to spacecraft. Also used on Earth. For example, rescuer on vessel or pier uses it to retrieve and haul drowning or unconscious person to safety; drifting person or rescuer in water uses it to grasp and hold onto support.

Hot cell examination on the surveillance capsule and HANARO capsule in IMEF

International Nuclear Information System (INIS)

Choo, Yong Sun; Oh, Wan Ho; Yoo, Byung Ok; Jung, Yang Hong; Ahn, Sang Bok; Baik, Seung Je; Song, Wung Sup; Hong, Kwon Pyo

2000-01-01

For the maintenance of integrity and safety of pressurizer of commercial power plant until its life span, it is required by US NRC 10CFR50 APP. G and H and ASTM E185-94 to periodically monitor irradiation embrittlement by neutron irradiation. In order to accomplished the requirement reactor operator has been carrying out the test by extracting the monitoring capsule embeded in reactor during the period of planned preventive maintenance. In relation to this irradiation samples are being used for prediction of reactor vessel life span and reactor vessel's adjusted reference temperature by irradiation of neutron flux enough to reach to end of life span. And also irradiation capsules with and without instrumentation are used for R and D on nuclear materials. Each capsule contains high radioactivity, therefore, post irradiation examination has to be handled by all means in the hot cell. The facility available for this purpose is Irradiated material examination facility (IMEF) to handle such works as capsule receiving, capsule cut and dismantling, sample classification, various examination, and finally development and improvement of examination equipment and instrumentation. (Hong, J. S.)

Diagnosis and surgical treatment of terminal syringomyelia within spinal cord combined with tethered cord syndrome

Directory of Open Access Journals (Sweden)

Jing-cheng XIE

2016-04-01

months to 14.50 years (average 6.10 years. All patients presented neurological intactness (McCormick gradeⅠ, recovery of conus medullaris, rising of the end of spinal cord, no recurrence of syringomyelia with favorable alignment of spine during follow- up period.  Conclusions Terminal syringomyelia in the spinal cord with TCS is rarely occurred and characterized by chronic dysfunction of spinal cord and nerve. The manifestation in MRI imaging is characterized by low level of spinal cord, disappearing of conus medullaris, long T1 and long T2 signal of filum terminale and spinal cord, and no enhancement of capsule wall. The surgical treatment includes resection of filum terminale, drainage of the cerebrospinal fluid (CSF in syringomyelia, and de-tethering of the spinal cord under microscope. The outcome is satisfactory. DOI: 10.3969/j.issn.1672-6731.2016.03.006

Investigation of electrodynamic stabilization and control of long orbiting tethers. [space shuttle payloads

Science.gov (United States)

Arnold, D. A.; Dobrowolny, M.

1981-01-01

An algorithm for using electric currents to control pendular oscillations induced by various perturbing forces on the Skyhook wire is considered. Transverse and vertical forces on the tether; tether instability modes and causes during retrieval by space shuttle; simple and spherical pendulum motion and vector damping; and current generation and control are discussed. A computer program for numerical integration of the in-plane and out-of-plane displacements of the tether vs time was developed for heuristic study. Some techniques for controlling instabilities during payload retrieval and methods for employing the tether for launching satellites from the space shuttle are considered. Derivations and analyses of a general nature used in all of the areas studied are included.

Position Control of an X4-Flyer Using a Tether

Directory of Open Access Journals (Sweden)

, Keigo Watanabe

2014-10-01

Full Text Available In Japan, aging of infrastructures, such as roads, bridges, and water and sewer services, etc. poses a problem, and it is required to extend the life-span of such infrastructures by maintenance. Among infrastructures, especially bridges are periodically inspected by short range visual observations, which check the damage and deterioration of the surface. However, since there are some cases where the short range visual observation is difficult, an alternative method is required so as to replace the short range visual observation with it. So, "X4-Flyer" is very attractive because of realizing a movement at high altitude easily. The objective of this study is to develop a tethered X4- Flyer, so that the conventional short range visual observation of bridges is replaced by it. In this paper, a method for the measurement and control of the position is described by using a tether for controlling the position of the X4-Flyer. In addition, it is checked whether the tethered X4-Flyer can control the position using the proposed method or not, letting it fly in a state in which a tether is being attached.

A video wireless capsule endoscopy system powered wirelessly: design, analysis and experiment

International Nuclear Information System (INIS)

Pan, Guobing; Chen, Jiaoliao; Xin, Wenhui; Yan, Guozheng

2011-01-01

Wireless capsule endoscopy (WCE), as a relatively new technology, has brought about a revolution in the diagnosis of gastrointestinal (GI) tract diseases. However, the existing WCE systems are not widely applied in clinic because of the low frame rate and low image resolution. A video WCE system based on a wireless power supply is developed in this paper. This WCE system consists of a video capsule endoscope (CE), a wireless power transmission device, a receiving box and an image processing station. Powered wirelessly, the video CE has the abilities of imaging the GI tract and transmitting the images wirelessly at a frame rate of 30 frames per second (f/s). A mathematical prototype was built to analyze the power transmission system, and some experiments were performed to test the capability of energy transferring. The results showed that the wireless electric power supply system had the ability to transfer more than 136 mW power, which was enough for the working of a video CE. In in vitro experiments, the video CE produced clear images of the small intestine of a pig with the resolution of 320 × 240, and transmitted NTSC format video outside the body. Because of the wireless power supply, the video WCE system with high frame rate and high resolution becomes feasible, and provides a novel solution for the diagnosis of the GI tract in clinic

Passive sorting of capsules by deformability

Science.gov (United States)

Haener, Edgar; Juel, Anne

We study passive sorting according to deformability of liquid-filled ovalbumin-alginate capsules. We present results for two sorting geometries: a straight channel with a half-cylindrical obstruction and a pinched flow fractioning device (PFF) adapted for use with capsules. In the half-cylinder device, the capsules deform as they encounter the obstruction, and travel around the half-cylinder. The distance from the capsule's centre of mass to the surface of the half-cylinder depends on deformability, and separation between capsules of different deformability is amplified by diverging streamlines in the channel expansion downstream of the obstruction. We show experimentally that capsules can be sorted according to deformability with their downstream position depending on capillary number only, and we establish the sensitivity of the device to experimental variability. In the PFF device, particles are compressed against a wall using a strong pinching flow. We show that capsule deformation increases with the intensity of the pinching flow, but that the downstream capsule position is not set by deformation in the device. However, when using the PFF device like a T-Junction, we achieve improved sorting resolution compared to the half-cylinder device.

Synthesis and insertion chemistry of mixed tether uranium metallocene complexes

Energy Technology Data Exchange (ETDEWEB)

Siladke, Nathan A.; LeDuc, Jennifer; Ziller, Joseph W.; Evans, William J. [Department of Chemistry, University of California, Irvine, CA (United States)

2012-11-12

The synthesis of mixed tethered alkyl uranium metallocenes has been investigated by examining the reactivity of the bis(tethered alkyl) metallocene [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC){sub 2}U] (1) with substrates that react with only one of the U-C linkages. The effect of these mixed tether coordination environments on the reactivity of the remaining U-C bond has been studied by using CO insertion chemistry. One equivalent of azidoadamantane (AdN{sub 3}) reacts with 1 to yield the mixed tethered alkyl triazenido complex [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC)U(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}-CH{sub 2}NNN-Ad-κ{sup 2}N{sup 1,3})]. Similarly, a single equivalent of CS{sub 2} reacts with 1 to form the mixed tethered alkyl dithiocarboxylate complex [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC)U(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}- CH{sub 2}C(S){sub 2}-κ{sup 2}S,S{sup '})], a reaction that constitutes the first example of CS{sub 2} insertion into a U{sup 4+}-C bond. Complex 1 reacts with one equivalent of pyridine N-oxide by C-H bond activation of the pyridine ring to form a mixed tethered alkyl cyclometalated pyridine N-oxide complex [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC)(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 3})U(C{sub 6}H{sub 4}NO-κ{sup 2} C,O)]. The remaining (η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC){sup 2-} ligand in each of these mixed tethered species show reactivity towards CO and tethered enolate ligands form by insertion. Subsequent rearrangement have been identified in [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 3})U(C{sub 5}H{sub 4}NO-κ{sup 2}C,O)(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}C(=CH{sub 2})O- κO)] and [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}NNN-Ad-κ{sup 2}N{sup 1,3})U(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}C(=CH{sub 2})O-κO)]. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Simulations of momentum transfer process between solar wind plasma and bias voltage tethers of electric sail thruster

Science.gov (United States)

Xia, Guangqing; Han, Yajie; Chen, Liuwei; Wei, Yanming; Yu, Yang; Chen, Maolin

2018-06-01

The interaction between the solar wind plasma and the bias voltage of long tethers is the basic mechanism of the electric sail thruster. The momentum transfer process between the solar wind plasma and electric tethers was investigated using a 2D full particle PIC method. The coupled electric field distribution and deflected ion trajectory under different bias voltages were compared, and the influence of bias voltage on momentum transfer process was analyzed. The results show that the high potential of the bias voltage of long tethers will slow down, stagnate, reflect and deflect a large number of ions, so that ion cavities are formed in the vicinity of the tether, and the ions will transmit the axial momentum to the sail tethers to produce the thrust. Compared to the singe tether, double tethers show a better thrust performance.

Low Earth Orbit Environmental Effects on Space Tether Materials

Science.gov (United States)

Finckernor, Miria M.; Gitlemeier, Keith A.; Hawk, Clark W.; Watts, Ed

2005-01-01

Atomic oxygen (AO) and ultraviolet (UV) radiation erode and embrittle most polymeric materials. This research was designed to test several different materials and coatings under consideration for their application to space tethers, for resistance to these effects. The samples were vacuum dehydrated, weighed and then exposed to various levels of AO or UV radiation at the NASA Marshall Space Flight Center. They were then re-weighed to determine mass loss due to atomic oxygen erosion, inspected for damage and tensile tested to determine strength loss. The experiments determined that the Photosil coating process, while affording some protection, damaged the tether materials worse than the AO exposure. TOR-LM also failed to fully protect the materials, especially from UV radiation. The POSS and nickel coatings did provide some protection to the tethers, which survived the entire test regime. M5 was tested, uncoated, and survived AO exposure, though its brittleness prevented any tensile testing.

Magnetically guided capsule endoscopy.

Science.gov (United States)

Shamsudhin, Naveen; Zverev, Vladimir I; Keller, Henrik; Pane, Salvador; Egolf, Peter W; Nelson, Bradley J; Tishin, Alexander M

2017-08-01

Wireless capsule endoscopy (WCE) is a powerful tool for medical screening and diagnosis, where a small capsule is swallowed and moved by means of natural peristalsis and gravity through the human gastrointestinal (GI) tract. The camera-integrated capsule allows for visualization of the small intestine, a region which was previously inaccessible to classical flexible endoscopy. As a diagnostic tool, it allows to localize the sources of bleedings in the middle part of the gastrointestinal tract and to identify diseases, such as inflammatory bowel disease (Crohn's disease), polyposis syndrome, and tumors. The screening and diagnostic efficacy of the WCE, especially in the stomach region, is hampered by a variety of technical challenges like the lack of active capsular position and orientation control. Therapeutic functionality is absent in most commercial capsules, due to constraints in capsular volume and energy storage. The possibility of using body-exogenous magnetic fields to guide, orient, power, and operate the capsule and its mechanisms has led to increasing research in Magnetically Guided Capsule Endoscopy (MGCE). This work shortly reviews the history and state-of-art in WCE technology. It highlights the magnetic technologies for advancing diagnostic and therapeutic functionalities of WCE. Not restricting itself to the GI tract, the review further investigates the technological developments in magnetically guided microrobots that can navigate through the various air- and fluid-filled lumina and cavities in the body for minimally invasive medicine. © 2017 American Association of Physicists in Medicine.

The motion and control of a complex three-body space tethered system

Science.gov (United States)

Shi, Gefei; Zhu, Zhanxia; Chen, Shiyu; Yuan, Jianping; Tang, Biwei

2017-11-01

This paper is mainly devoted to investigating the dynamics and stability control of a three body-tethered satellite system which contains a main satellite and two subsatellites connected by two straight, massless and inextensible tethers. Firstly, a detailed mathematical model is established in the central gravitational field. Then, the dynamic characteristics of the established system are investigated and analyzed. Based on the dynamic analysis, a novel sliding mode prediction model (SMPM) control strategy is proposed to suppress the motion of the built tethered system. The numerical results show that the proposed underactuated control law is highly effective in suppressing the attitude/libration motion of the underactuated three-body tethered system. Furthermore, cases of different target angles are also examined and analyzed. The simulation results reveal that even if the final equilibrium states differ from different selections of the target angles, the whole system can still be maintained in acceptable areas.

Emerging insights into the roles of membrane tethers from analysis of whole organisms: The tip of an iceberg?

Directory of Open Access Journals (Sweden)

Wei Hong eToh

2016-02-01

Full Text Available Membrane tethers have been identified throughout different compartments of the endomembrane system. It is now well established that a number of membrane tethers mediate docking of membrane carriers in anterograde and retrograde transport and in regulating the organization of membrane compartments. Much of our information on membrane tethers have been obtained from the analysis of individual membrane tethers in cultured cells. In the future it will be important to better appreciate the network of interactions mediated by tethers and the potential co-ordination of their collective functions in vivo. There are now a number of studies which have analyzed membrane tethers in tissues and organisms which are providing new insights into the role of this class of membrane protein at the physiological level. Here we review recent advances in the understanding of the function of membrane tethers from knock outs (or knock downs in whole organisms and from mutations in tethers associated with disease.

Experiments and simulation of a net closing mechanism for tether-net capture of space debris

Science.gov (United States)

Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

2017-10-01

This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

Cooperative networks : The mobile tethering game

NARCIS (Netherlands)

Constantinescu, M.; Bouwman, H.; Djurica, M.; Durmus, Y.; Onur, E.; Reuver, M. de

2012-01-01

We propose an analysis of cooperation for data sharing and the behavioral aspects involved in the process of decision making. Starting with the tethering capabilities of recent devices we apply game theoretical principles and models, inquire what makes the cooperation work, and what are the

ER-to-plasma membrane tethering proteins regulate cell signaling and ER morphology.

Science.gov (United States)

Manford, Andrew G; Stefan, Christopher J; Yuan, Helen L; Macgurn, Jason A; Emr, Scott D

2012-12-11

Endoplasmic reticulum-plasma membrane (ER-PM) junctions are conserved structures defined as regions of the ER that tightly associate with the plasma membrane. However, little is known about the mechanisms that tether these organelles together and why such connections are maintained. Using a quantitative proteomic approach, we identified three families of ER-PM tethering proteins in yeast: Ist2 (related to mammalian TMEM16 ion channels), the tricalbins (Tcb1/2/3, orthologs of the extended synaptotagmins), and Scs2 and Scs22 (vesicle-associated membrane protein-associated proteins). Loss of all six tethering proteins results in the separation of the ER from the PM and the accumulation of cytoplasmic ER. Importantly, we find that phosphoinositide signaling is misregulated at the PM, and the unfolded protein response is constitutively activated in the ER in cells lacking ER-PM tether proteins. These results reveal critical roles for ER-PM contacts in cell signaling, organelle morphology, and ER function. Copyright © 2012 Elsevier Inc. All rights reserved.

Tethered balloon-based measurements of meteorological variables and aerosols

Science.gov (United States)

Sentell, R. J.; Storey, R. W.; Chang, J. J. C.; Jacobsen, S. J.

1976-01-01

Tethered balloon based measurements of the vertical distributions of temperature, humidity, wind speed, and aerosol concentrations were taken over a 4-hour period beginning at sunrise on June 29, 1976, at Wallops Island, Virginia. Twelve consecutive profiles of each variable were obtained from ground to about 500 meters. These measurements were in conjuction with a noise propagation study on remotely arrayed acoustic range (ROMAAR) at Wallops Flight Center. An organized listing of these vertical soundings is presented. The tethered balloon system configuration utilized for these measurements is described.

Current Innovations in Endoscopic Therapy for the Management of Colorectal Cancer: From Endoscopic Submucosal Dissection to Endoscopic Full-Thickness Resection

Directory of Open Access Journals (Sweden)

Shintaro Fujihara

2014-01-01

Full Text Available Endoscopic submucosal dissection (ESD is accepted as a minimally invasive treatment for colorectal cancer. However, due to technical difficulties and an increased rate of complications, ESD is not widely used in the colorectum. In some cases, endoscopic treatment alone is insufficient for disease control, and laparoscopic surgery is required. The combination of laparoscopic surgery and endoscopic resection represents a new frontier in cancer treatment. Recent developments in advanced polypectomy and minimally invasive surgical techniques will enable surgeons and endoscopists to challenge current practice in colorectal cancer treatment. Endoscopic full-thickness resection (EFTR of the colon offers the potential to decrease the postoperative morbidity and mortality associated with segmental colectomy while enhancing the diagnostic yield compared to current endoscopic techniques. However, closure is necessary after EFTR and natural transluminal endoscopic surgery (NOTES. Innovative methods and new devices for EFTR and suturing are being developed and may potentially change traditional paradigms to achieve minimally invasive surgery for colorectal cancer. The present paper aims to discuss the complementary role of ESD and the future development of EFTR. We focus on the possibility of achieving EFTR using the ESD method and closing devices.

Probing cell internalisation mechanics with polymer capsules.

Science.gov (United States)

Chen, Xi; Cui, Jiwei; Ping, Yuan; Suma, Tomoya; Cavalieri, Francesca; Besford, Quinn A; Chen, George; Braunger, Julia A; Caruso, Frank

2016-10-06

We report polymer capsule-based probes for quantifying the pressure exerted by cells during capsule internalisation (P in ). Poly(methacrylic acid) (PMA) capsules with tuneable mechanical properties were fabricated through layer-by-layer assembly. The P in was quantified by correlating the cell-induced deformation with the ex situ osmotically induced deformation of the polymer capsules. Ultimately, we found that human monocyte-derived macrophage THP-1 cells exerted up to approximately 360 kPa on the capsules during internalisation.

Endoscopic submucosal dissection

DEFF Research Database (Denmark)

Pimentel-Nunes, Pedro; Dinis-Ribeiro, Mário; Ponchon, Thierry

2015-01-01

evidence). 2 ESGE recommends endoscopic resection with a curative intent for visible lesions in Barrett's esophagus (strong recommendation, moderate quality evidence). ESD has not been shown to be superior to EMR for excision of mucosal cancer, and for that reason EMR should be preferred. ESD may...... RECOMMENDATIONS: 1 ESGE recommends endoscopic en bloc resection for superficial esophageal squamous cell cancers (SCCs), excluding those with obvious submucosal involvement (strong recommendation, moderate quality evidence). Endoscopic mucosal resection (EMR) may be considered in such lesions when...

Endoscopic Devices for Obesity.

Science.gov (United States)

Sampath, Kartik; Dinani, Amreen M; Rothstein, Richard I

2016-06-01

The obesity epidemic, recognized by the World Health Organization in 1997, refers to the rising incidence of obesity worldwide. Lifestyle modification and pharmacotherapy are often ineffective long-term solutions; bariatric surgery remains the gold standard for long-term obesity weight loss. Despite the reported benefits, it has been estimated that only 1% of obese patients will undergo surgery. Endoscopic treatment for obesity represents a potential cost-effective, accessible, minimally invasive procedure that can function as a bridge or alternative intervention to bariatric surgery. We review the current endoscopic bariatric devices including space occupying devices, endoscopic gastroplasty, aspiration technology, post-bariatric surgery endoscopic revision, and obesity-related NOTES procedures. Given the diverse devices already FDA approved and in development, we discuss the future directions of endoscopic therapies for obesity.

A tethering complex drives the terminal stage of SNARE-dependent membrane fusion

Science.gov (United States)

D'Agostino, Massimo; Risselada, Herre Jelger; Lürick, Anna; Ungermann, Christian; Mayer, Andreas

2017-11-01

Membrane fusion in eukaryotic cells mediates the biogenesis of organelles, vesicular traffic between them, and exo- and endocytosis of important signalling molecules, such as hormones and neurotransmitters. Distinct tasks in intracellular membrane fusion have been assigned to conserved protein systems. Tethering proteins mediate the initial recognition and attachment of membranes, whereas SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein complexes are considered as the core fusion engine. SNARE complexes provide mechanical energy to distort membranes and drive them through a hemifusion intermediate towards the formation of a fusion pore. This last step is highly energy-demanding. Here we combine the in vivo and in vitro fusion of yeast vacuoles with molecular simulations to show that tethering proteins are critical for overcoming the final energy barrier to fusion pore formation. SNAREs alone drive vacuoles only into the hemifused state. Tethering proteins greatly increase the volume of SNARE complexes and deform the site of hemifusion, which lowers the energy barrier for pore opening and provides the driving force. Thereby, tethering proteins assume a crucial mechanical role in the terminal stage of membrane fusion that is likely to be conserved at multiple steps of vesicular traffic. We therefore propose that SNAREs and tethering proteins should be considered as a single, non-dissociable device that drives fusion. The core fusion machinery may then be larger and more complex than previously thought.

Observing Formation of Flux Rope by Tether-cutting Reconnection in the Sun

Energy Technology Data Exchange (ETDEWEB)

Xue, Zhike; Yan, Xiaoli; Yang, Liheng; Wang, Jincheng; Zhao, Li, E-mail: zkxue@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, Kunming Yunnan 650216 (China)

2017-05-10

Tether-cutting reconnection is considered as one mechanism for the formation of a flux rope. It has been proposed for more than 30 years; however, so far, direct observations of it are very rare. In this Letter, we present observations of the formation of a flux rope via tether-cutting reconnection in NOAA AR 11967 on 2014 February 2 by combining observations with the New Vacuum Solar Telescope and the Solar Dynamic Observatory . The tether-cutting reconnection occurs between two sets of highly sheared magnetic arcades. Comprehensive observational evidence of the reconnection is as follows: changes of the connections between the arcades, brightenings at the reconnection site, hot outflows, formation of a flux rope, slow-rise motion of the flux rope, and flux cancelation. The outflows are along three directions from the reconnection site to the footpoints with the velocities from 24 ± 1 km s{sup −1} to 69 ± 5 km s{sup −1}. Additionally, it is found that the newly formed flux rope connects far footpoints and has a left-handed twisted structure with many fine threads and a concave-up-shape structure in the middle. All the observations are in agreement with the tether-cutting model and provide evidence that tether-cutting reconnection leads to the formation of the flux rope associated with flux shear flow and cancelation.

Relaxation Dynamics of Nanoparticle-Tethered Polymer Chains

KAUST Repository

Kim, Sung A; Mangal, Rahul; Archer, Lynden A.

2015-01-01

© 2015 American Chemical Society. Relaxation dynamics of nanoparticle-tethered cis-1,4-polyisoprene (PI) are investigated using dielectric spectroscopy and rheometry. A model system composed of polymer chains densely grafted to spherical SiO2

Phobos L1 Operational Tether Experiment (PHLOTE)

Data.gov (United States)

National Aeronautics and Space Administration — A sensor package that “floats” just above the surface of Phobos, suspended by a tether from a small spacecraft operating at the Mars/Phobos Lagrange 1 (L1) Point...

endoscope-i: an innovation in mobile endoscopic technology transforming the delivery of patient care in otolaryngology.

Science.gov (United States)

Mistry, N; Coulson, C; George, A

2017-11-01

Digital and mobile device technology in healthcare is a growing market. The introduction of the endoscope-i, the world's first endoscopic mobile imaging system, allows the acquisition of high definition images of the ear, nose and throat (ENT). The system combines the e-i Pro camera app with a bespoke engineered endoscope-i adaptor which fits securely onto the iPhone or iPod touch. Endoscopic examination forms a salient aspect of the ENT work-up. The endoscope-i therefore provides a mobile and compact alternative to the existing bulky endoscopic systems currently in use which often restrict the clinician to the clinic setting. Areas covered: This article gives a detailed overview of the endoscope-i system together with its applications. A review and comparison of alternative devices on the market offering smartphone adapted endoscopic viewing systems is also presented. Expert commentary: The endoscope-i fulfils unmet needs by providing a compact, highly portable, simple to use endoscopic viewing system which is cost-effective and which makes use of smartphone technology most clinicians have in their pocket. The system allows real-time feedback to the patient and has the potential to transform the way that healthcare is delivered in ENT as well as having applications further afield.

Status of irradiation capsule design

International Nuclear Information System (INIS)

Nagata, Hiroshi; Yamaura, Takayuki; Nagao, Yoshiharu

2013-01-01

For the irradiation test after the restart of JMTR, further precise temperature control and temperature prediction are required. In the design of irradiation capsule, particularly sophisticated irradiation temperature prediction and evaluation are urged. Under such circumstance, among the conventional design techniques of irradiation capsule, the authors reviewed the evaluation method of irradiation temperature. In addition, for the improvement of use convenience, this study examined and improved FINAS/STAR code in order to adopt the new calculation code that enables a variety of analyses. In addition, the study on the common use of the components for radiation capsule enabled the shortening of design period. After the restart, the authors will apply this improved calculation code to the design of irradiation capsule. (A.O.)

Endoscopic management of colorectal adenomas.

Science.gov (United States)

Meier, Benjamin; Caca, Karel; Fischer, Andreas; Schmidt, Arthur

2017-01-01

Colorectal adenomas are well known precursors of invasive adenocarcinoma. Colonoscopy is the gold standard for adenoma detection. Colonoscopy is far more than a diagnostic tool, as it allows effective treatment of colorectal adenomas. Endoscopic resection of colorectal adenomas has been shown to reduce the incidence and mortality of colorectal cancer. Difficult resection techniques are available, such as endoscopic mucosal resection, endoscopic submucosal dissection and endoscopic full-thickness resection. This review aims to provide an overview of the different endoscopic resection techniques and their indications, and summarizes the current recommendations in the recently published guideline of the European Society of Gastrointestinal Endoscopy.

Lumbosacral arachnoid cyst with tethered cord: A rare case report

Directory of Open Access Journals (Sweden)

S K Jain

2012-01-01

Full Text Available Arachnoid cysts are cerebrospinal fluid collections in the spine that can present with neurological symptoms or be discovered accidentally. Intradural location of such cysts especially in the lumbosacral region is relatively rare. The association of such cysts with other congenital anomalies such as tethered cord lends evidence to the developmental origin of arachnoid cysts. We report a case of lumbosacral arachnoid cyst with tethered cord in a 6-year-old male child and discuss the etiopathogenesis and management options.

Unilateral pedicle screws asymmetric tethering: an innovative method to create idiopathic deformity

Directory of Open Access Journals (Sweden)

Zhang Xuesong

2007-10-01

Full Text Available Abstract Objective To evaluate the feasibility of the method that unilateral pedicle screws asymmetric tethering in concave side in combination with convex rib resection for creating idiopathic deformity. Summary of background data Various methods are performed to create idiopathic deformity. Among these methods, posterior asmmetric tethering of the spine shows satisfying result, but some drawbacks related to the current posterior asymmetric tether were still evident. Materials and methods Unilateral pedicle screws asymmetric tethering was performed to 14 female goats (age: 5–8 week-old, weight: 6–8 kg in concave side in combination with convex rib resection. Dorsoventral and lateral plain radiographs were taken of each thoracic spine in the frontal and sagittal planes right after the surgery and later every 4 weeks. Results All animals ambulated freely after surgery. For technical reasons, 2 goats were excluded (one animal died for anesthetic during the surgery, and one animal was lost for instrumental fail due to postoperative infection. Radiography showed that 11 goats exhibited scoliosis with convex toward to the right side, and as the curve increased with time, only 1 goat showed nonprogressive. The initial scoliosis generated in the progressors after the procedures measured 29.0° on average (range 23.0°–38.5° and increased to 43.0° on average (range 36.0°–58.0° over 8 to 10 weeks. The average progression of 14.0° was measured. The curvature immediately after tethering surgery (the initial Cobb angle did have a highly significant correlation with the final curvature (p Conclusion Unilateral pedicle screws asymmetric tethering is a practical method to create experimental scoliosis, especially for those who would like to study the correction of this deformity.

Foot-controlled robotic-enabled endoscope holder for endoscopic sinus surgery: A cadaveric feasibility study.

Science.gov (United States)

Chan, Jason Y K; Leung, Iris; Navarro-Alarcon, David; Lin, Weiyang; Li, Peng; Lee, Dennis L Y; Liu, Yun-hui; Tong, Michael C F

2016-03-01

To evaluate the feasibility of a unique prototype foot-controlled robotic-enabled endoscope holder (FREE) in functional endoscopic sinus surgery. Cadaveric study. Using human cadavers, we investigated the feasibility, advantages, and disadvantages of the robotic endoscope holder in performing endoscopic sinus surgery with two hands in five cadaver heads, mimicking a single nostril three-handed technique. The FREE robot is relatively easy to use. Setup was quick, taking less than 3 minutes from docking the robot at the head of the bed to visualizing the middle meatus. The unit is also relatively small, takes up little space, and currently has four degrees of freedom. The learning curve for using the foot control was short. The use of both hands was not hindered by the presence of the endoscope in the nasal cavity. The tremor filtration also aided in the smooth movement of the endoscope, with minimal collisions. The FREE endoscope holder in an ex-vivo cadaver test corroborated the feasibility of the robotic prototype, which allows for a two-handed approach to surgery equal to a single nostril three-handed technique without the holder that may reduce operating time. Further studies will be needed to evaluate its safety profile and use in other areas of endoscopic surgery. NA. Laryngoscope, 126:566-569, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Titanium-tethered vancomycin prevents resistance to rifampicin in Staphylococcus aureus in vitro.

Directory of Open Access Journals (Sweden)

Martin Rottman

Full Text Available Rifampicin is currently recognized as the most potent drug against Gram positive implant related infections. The use of rifampicin is limited by the emergence of bacterial resistance, which is often managed by coadministration of a second antibiotic. The purpose of this study was to determine the effectiveness of soluble rifampicin in combination with vancomycin tethered to titanium metal as a means to control bacterial growth and resistance in vitro. Bacterial growth was inhibited when the vancomycin-tethered titanium discs were treated with Staphylococcus aureus inocula of ≤2×10⁶ CFU, however inocula greater than 2×10⁶ CFU/disc adhered and survived. The combination of surface-tethered vancomycin with soluble rifampicin enhanced the inhibitory effect of rifampicin for an inoculum of 10⁶ CFU/cm² by one dilution (combination MIC of 0.008 mg/L versus 0.015 mg/L for rifampicin alone. Moreover, surface tethered vancomycin prevented the emergence of a rifampicin resistant population in an inoculum of 2×10⁸ CFU.

Learning endoscopic resection in the esophagus

NARCIS (Netherlands)

van Vilsteren, Frederike G. I.; Pouw, Roos E.; Herrero, Lorenza Alvarez; Bisschops, Raf; Houben, Martin; Peters, Frans T. M.; Schenk, B. E.; Weusten, Bas L. A. M.; Schoon, Erik J.; Bergman, Jacques J. G. H. M.

Background: Endoscopic resection is the cornerstone of endoscopic management of esophageal early neoplasia. However, endoscopic resection is a complex technique requiring knowledge and expertise. Our aims were to identify the most important learning points in performing endoscopic resection in a

Intrauterine fertilization capsules--a clinical trial

DEFF Research Database (Denmark)

Lenz, S; Lindenberg, S; Sundberg, K

1991-01-01

Treatment of 26 women with tubal infertility was attempted using intrauterine capsules loaded with oocytes and spermatozoa. The stimulation protocol was as used for in vitro fertilization and embryo transfer and consisted of short-term use of Buserelin, human menopausal gonadotropin, and human...... and piston from an intrauterine device. Six complete capsules and parts of two other capsules were expelled. None of the women became pregnant, compared with a pregnancy rate of 21% per aspiration following in vitro fertilization and embryo transfer during the same period....... chorionic gonadotropin. Oocytes were collected by ultrasonically guided transvaginal aspiration, and spermatozoa were prepared by swim-up technique. The gametes were placed in agar capsules 4 hr after oocyte collection, and the capsules were introduced to the uterine fundus using an insertion tube...

Two-Stage Winch for Kites and Tethered Balloons or Blimps

Science.gov (United States)

Miles, Ted; Bland, Geoff

2011-01-01

A winch system provides a method for launch and recovery capabilities for kites and tethered blimps or balloons. Low power consumption is a key objective, as well as low weight for portability. This is accomplished by decoupling the tether-line storage and wind ing/ unwinding functions, and providing tailored and efficient mechanisms for each. The components of this system include rotational power input devices such as electric motors or other apparatus, line winding/unwinding reel(s), line storage reel(s), and independent drive trains. Power is applied to the wind/unwind reels to transport the tether line. Power is also applied to a line storage reel, from either the wind/unwind power source, the wind/unwind reel itself, or separate power source. The speeds of the two reels are synchronized, but not dependent on each other. This is accomplished via clutch mechanisms, variable transmissions, or independent motor controls. The speed of the storage reel is modulated as the effective diameter of the reel changes with line accumulation.

High-speed precision weighing of pharmaceutical capsules

International Nuclear Information System (INIS)

Bürmen, Miran; Pernuš, Franjo; Likar, Boštjan

2009-01-01

In this paper, we present a cost-effective method for fast and accurate in-line weighing of hard gelatin capsules based on the optimized capacitance sensor and real-time processing of the capsule capacitance profile resulting from 5000 capacitance measurements per second. First, the effect of the shape and size of the capacitive sensor on the sensitivity and stability of the measurements was investigated in order to optimize the performance of the system. The method was tested on two types of hard gelatin capsules weighing from 50 mg to 650 mg. The results showed that the capacitance profile was exceptionally well correlated with the capsule weight with the correlation coefficient exceeding 0.999. The mean precision of the measurements was in the range from 1 mg to 3 mg, depending on the size of the capsule and was significantly lower than the 5% weight tolerances usually used by the pharmaceutical industry. Therefore, the method was found feasible for weighing pharmaceutical hard gelatin capsules as long as certain conditions are met regarding the capsule fill properties and environment stability. The proposed measurement system can be calibrated by using only two or three sets of capsules with known weight. However, for most applications it is sufficient to use only empty and nominally filled capsules for calibration. Finally, a practical application of the proposed method showed that a single system is capable of weighing around 75 000 capsules per hour, while using multiple systems could easily increase the inspection rate to meet almost any requirements

Thermoregulation of Capsule Production by Streptococcus pyogenes

Science.gov (United States)

Kang, Song Ok; Wright, Jordan O.; Tesorero, Rafael A.; Lee, Hyunwoo; Beall, Bernard; Cho, Kyu Hong

2012-01-01

The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface. PMID:22615992

FCAPD Protective Coating for Space Tethers, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Alameda Applied Sciences Corporation (AASC) proposes to demonstrate extended service lifetime of space tethers in the Low Earth Orbit (LEO) environment by using...

NIF capsule performance modeling

Directory of Open Access Journals (Sweden)

Weber S.

2013-11-01

Full Text Available Post-shot modeling of NIF capsule implosions was performed in order to validate our physical and numerical models. Cryogenic layered target implosions and experiments with surrogate targets produce an abundance of capsule performance data including implosion velocity, remaining ablator mass, times of peak x-ray and neutron emission, core image size, core symmetry, neutron yield, and x-ray spectra. We have attempted to match the integrated data set with capsule-only simulations by adjusting the drive and other physics parameters within expected uncertainties. The simulations include interface roughness, time-dependent symmetry, and a model of mix. We were able to match many of the measured performance parameters for a selection of shots.

Herniation of the anterior lens capsule

Directory of Open Access Journals (Sweden)

Pereira Nolette

2007-01-01

Full Text Available Herniation of the anterior lens capsule is a rare abnormality in which the capsule bulges forward in the pupillary area. This herniation can be mistaken for an anterior lenticonus where both the capsule and the cortex bulge forward. The exact pathology behind this finding is still unclear. We report the clinical, ultrasound biomicroscopy (UBM and histopathological findings of a case of herniation of the anterior lens capsule. UBM helped to differentiate this entity from anterior lenticonus. Light microscopy revealed capsular splitting suggestive of capsular delamination and collection of fluid (aqueous in the area of herniation giving it a characteristic appearance.

Diagnostic and therapeutic radio pharmaceutical capsules

International Nuclear Information System (INIS)

Haney, T.A.; Wedeking, P.W.; Morcos, N.A.

1981-01-01

An improved pharmaceutical radioactive capsule consisting of a non-toxic, water soluble material adapted to being ingested and rapidly disintegrating on contact with fluids of the gastro-intestinal tract is described. Each capsule is provided with filler material supporting a pharmaceutically useful radioactive compound absorbable from the gastro-intestinal tract. The capsule is preferably of gelatin, methyl cellulose or polyvinyl alcohol and the filler is a polyethylene glycol. The radioactive compound may be iodine e.g. sodium radioiodide I-131 or 123. The capsule may also contain a reducing agent e.g. sodium thiosulphate, sulphite, or bisulphite. (author)

The ATPases of cohesin interface with regulators to modulate cohesin-mediated DNA tethering

Science.gov (United States)

Çamdere, Gamze; Guacci, Vincent; Stricklin, Jeremiah; Koshland, Douglas

2015-01-01

Cohesin tethers together regions of DNA, thereby mediating higher order chromatin organization that is critical for sister chromatid cohesion, DNA repair and transcriptional regulation. Cohesin contains a heterodimeric ATP-binding Cassette (ABC) ATPase comprised of Smc1 and Smc3 ATPase active sites. These ATPases are required for cohesin to bind DNA. Cohesin’s DNA binding activity is also promoted by the Eco1 acetyltransferase and inhibited by Wpl1. Recently we showed that after cohesin stably binds DNA, a second step is required for DNA tethering. This second step is also controlled by Eco1 acetylation. Here, we use genetic and biochemical analyses to show that this second DNA tethering step is regulated by cohesin ATPase. Furthermore, our results also suggest that Eco1 promotes cohesion by modulating the ATPase cycle of DNA-bound cohesin in a state that is permissive for DNA tethering and refractory to Wpl1 inhibition. DOI: http://dx.doi.org/10.7554/eLife.11315.001 PMID:26583750

Endoscopic submucosal dissection for locally recurrent colorectal lesions after previous endoscopic mucosal resection.

Science.gov (United States)

Zhou, Pinghong; Yao, Liqing; Qin, Xinyu; Xu, Meidong; Zhong, Yunshi; Chen, Weifeng

2009-02-01

The objective of this study was to determine the efficacy and safety of endoscopic submucosal dissection for locally recurrent colorectal cancer after previous endoscopic mucosal resection. A total of 16 patients with locally recurrent colorectal lesions were enrolled. A needle knife, an insulated-tip knife and a hook knife were used to resect the lesion along the submucosa. The rate of the curative resection, procedure time, and incidence of complications were evaluated. Of 16 lesions, 15 were completely resected with endoscopic submucosal dissection, yielding an en bloc resection rate of 93.8 percent. Histologic examination confirmed that lateral and basal margins were cancer-free in 14 patients (87.5 percent). The average procedure time was 87.2 +/- 60.7 minutes. None of the patients had immediate or delayed bleeding during or after endoscopic submucosal dissection. Perforation in one patient (6.3 percent) was the only complication and was managed conservatively. The mean follow-up period was 15.5 +/- 6.8 months; none of the patients experienced lesion residue or recurrence. Endoscopic submucosal dissection appears to be effective for locally recurrent colorectal cancer after previous endoscopic mucosal resection, making it possible to resect whole lesions and provide precise histologic information.

The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

Energy Technology Data Exchange (ETDEWEB)

Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A. [Department of Mechanical Engineering, University of Sheffield, Mappin St., Sheffield, S1 3JD, England (United Kingdom)

2014-12-10

The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design.

The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

International Nuclear Information System (INIS)

Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A.

2014-01-01

The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design

Electrodynamic Tethers and E-Sails as Active Experiment Testbeds and Technologies in Space

Science.gov (United States)

Gilchrist, B. E.; Wiegmann, B.; Johnson, L.; Bilen, S. G.; Habash Krause, L.; Miars, G.; Leon, O.

2017-12-01

The use of small-to-large flexible structures in space such as tethers continues to be studied for scientific and technology applications. Here we will consider tether electrodynamic and electrostatic interactions with magneto-plasmas in ionospheres, magnetospheres, and interplanetary space. These systems are enabling fundamental studies of basic plasma physics phenomena, allowing direct studies of the space environment, and generating technological applications beneficial for science missions. Electrodynamic tethers can drive current through the tether based on the Lorenz force adding or extracting energy from its orbit allowing for the study of charged bodies or plasma plumes moving through meso-sonic magnetoplasmas [1]. Technologically, this also generates propulsive forces requiring no propellant and little or no consumables in any planetary system with a magnetic field and ionosphere, e.g., Jupiter [2]. Further, so called electric sails (E-sails) are being studied to provide thrust through momentum exchange with the hypersonic solar wind. The E-sail uses multiple, very long (10s of km) charged, mostly bare rotating conducting tethers to deflect solar wind protons. It is estimated that a spacecraft could achieve a velocity over 100 km/s with time [3,4]. 1. Banks, P.M., "Review of electrodynamic tethers for space plasma science," J. Spacecraft and Rockets, vol. 26, no. 4, pp. 234-239, 1989. 2. Talley, C., J. Moore, D. Gallagher, and L. Johnson, "Propulsion and power from a rotating electrodynamic tether at Jupiter," 38th AIAA Aerospace Sciences Meeting and Exhibit, January 2000. 3. Janhunen, P., "The electric sail—A new propulsion method which may enable fast missions to the outer solar system," J. British Interpl. Soc., vol. 61, no. 8, pp. 322-325, 2008. 4. Wiegman, B., T. Scheider, A. Heaton, J. Vaughn, N. Stone, and K. Wright, "The Heliopause Electrostatic Rapid Transit System (HERTS)—Design, trades, and analyses performed in a two-year NASA investigation

Increasing Z-pinch vacuum hohlraum capsule coupling efficiency

International Nuclear Information System (INIS)

Callahan, Debbie; Vesey, Roger Alan; Cochrane, Kyle Robert; Nikroo, A.; Bennett, Guy R.; Schroen, Diana Grace; Ruggles, Laurence E.; Porter, John L.; Streit, Jon; Mehlhorn, Thomas Alan; Cuneo, Michael Edward

2004-01-01

Symmetric capsule implosions in the double-ended vacuum hohlraum (DEH) on Z have demonstrated convergence ratios of 14-21 for 2.15-mm plastic ablator capsules absorbing 5-7 kJ of x-rays, based on backlit images of the compressed ablator remaining at peak convergence (1). Experiments with DD-filled 3.3-mm diameter capsules designed to absorb 14 kJ of x-rays have begun as an integrated test of drive temperature and symmetry, complementary to thin-shell symmetry diagnostic capsules. These capsule implosions are characterized by excellent control of symmetry (< 3% time-integrated), but low hohlraum efficiency (< 2%). Possible methods to increase the capsule absorbed energy in the DEH include mixed-component hohlraums, large diameter foam ablator capsules, transmissive shine shields between the z-pinch and capsule, higher spoke electrode x-ray transmission, a double-sided power feed, and smaller initial radius z-pinch wire arrays. Simulations will explore the potential for each of these modifications to increase the capsule coupling efficiency for near-term experiments on Z and ZR

21 CFR 520.1660b - Oxytetracycline hydrochloride capsules.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride capsules. 520.1660b... Oxytetracycline hydrochloride capsules. (a) Specifications. The drug is in capsule form with each capsule containing 125 or 250 milligrams of oxytetracycline hydrochloride. Oxytetracycline is the antibiotic...

Thermal characteristic test for saturated temperature type capsule

International Nuclear Information System (INIS)

Niimi, Motoji; Someya, Hiroyuki; Kobayashi, Toshiki; Ohuchi, Mitsuo; Harayama, Yasuo

1989-08-01

The Japan Material Testing Reactor Project is developing a new type capsule so-called 'Saturated Temperature Capsule', as a part of irradiation technique improvement program. This type capsule, in which the water is supplied and boiled, bases on the conception of keeping the coolant at the saturated temperature and facilitating the temperature setting of specimens heated by gamma-ray in reactor. However, out-pile test was planned, because there were few usable data for design and operation of the capsule into which the coolant was injected. A out-pile apparatus, simulated the capsule with electric heaters, was fabricated and experiments were carried out, to obtain data concerning design and operation for the capsule into which the water was injected. As a structure of simulated capsule, a type of downward coolant supply was adopted. The downward coolant tube type injectes the water in the bottom of capsule by tube through the upper flange. Major objects of experiences were to grasp thermal features under operation and to provide performances of capsule control equipment. Experimental results proved that the temperature of water within the capsule was easily varied by controlling supply water flow rate, and that the control equipment was operated stably and safety. (author)

Tethered Aerostat Effects on Nearby Seismometers

Energy Technology Data Exchange (ETDEWEB)

Bowman, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-12-01

This report assesses seismic interference generated by a tethered aerostat. The study was motivated by a planned aerostat deployment within the footprint of the Dry Alluvium Geology seismic network. No evidence was found for seismic interference generated by the aerostat, and thus the e ects on the Dry Alluvium Geology sensors will be negligible.

Capsule safety analysis of PRTF irradiation facility

International Nuclear Information System (INIS)

Suwarto

2013-01-01

Power Ramp Test Facility (PRTF) is an irradiation facility used for fuel testing of power reactor. PRTF has a capsule which is a test fuel rod container. During operation, pressurized water of 160 bars flows through in the capsule. Due to the high pressure it should be analyzed the impact of the capsule on reactor core safety. This analysis has purpose to calculate the ability of capsule pressure capacity. The analysis was carried out by calculating pressure capacity. From the calculating results it can be concluded that the capsule with pressure capacity of 438 bars will be safe to prevent the operation pressure of PRTF. (author)

Endoscopic therapy of neoplasia related to Barrett's esophagus and endoscopic palliation of esophageal cancer.

Science.gov (United States)

Vignesh, Shivakumar; Hoffe, Sarah E; Meredith, Kenneth L; Shridhar, Ravi; Almhanna, Khaldoun; Gupta, Akshay K

2013-04-01

Barrett's esophagus (BE) is the most important identifiable risk factor for the progression to esophageal adenocarcinoma. This article reviews the current endoscopic therapies for BE with high-grade dysplasia and intramucosal cancer and briefly discusses the endoscopic palliation of advanced esophageal cancer. The diagnosis of low-grade or high-grade dysplasia (HGD) is based on several cytologic criteria that suggest neoplastic transformation of the columnar epithelium. HGD and carcinoma in situ are regarded as equivalent. The presence of dysplasia, particularly HGD, is also a risk factor for synchronous and metachronous adenocarcinoma. Dysplasia is a marker of adenocarcinoma and also has been shown to be the preinvasive lesion. Esophagectomy has been the conventional treatment for T1 esophageal cancer and, although debated, is an appropriate option in some patients with HGD due to the presence of occult cancer in over one-third of patients. Endoscopic ablative modalities (eg, photodynamic therapy and cryoablation) and endoscopic resection techniques (eg, endoscopic mucosal resection) have demonstrated promising results. The significant morbidity and mortality of esophagectomy makes endoscopic treatment an attractive potential option.

Endoscope-Assisted Transoral Fixation of Mandibular Condyle Fractures: Submandibular Versus Transoral Endoscopic Approach.

Science.gov (United States)

Hwang, Na-Hyun; Lee, Yoon-Hwan; You, Hi-Jin; Yoon, Eul-Sik; Kim, Deok-Woo

2016-07-01

In recent years, endoscope-assisted transoral approach for condylar fracture treatment has attracted much attention. However, the surgical approach is technically challenging: the procedure requires specialized instruments and the surgeons experience a steep learning curve. During the transoral endoscopic (TE) approach several instruments are positioned through a narrow oral incision making endoscope maneuvering very difficult. For this reason, the authors changed the entry port of the endoscope from transoral to submandibular area through a small stab incision. The aim of this study is to assess the advantage of using the submandibular endoscopic intraoral approach (SEI).The SEI approach requires intraoral incision for fracture reduction and fixation, and 4 mm size submandibular stab incision for endoscope and traction wires. Fifteen patients with condyle neck and subcondyle fractures were operated under the submandibular approach and 15 patients with the same diagnosis were operated under the standard TE approach.The SEI approach allowed clear visualization of the posterior margin of the ramus and condyle, and the visual axis was parallel to the condyle ramus unit. The TE approach clearly shows the anterior margin of the condyle and the sigmoid notch. The surgical time of the SEI group was 128 minutes and the TE group was 120 minutes (P >0.05). All patients in the TE endoscope group were fixated with the trocar system, but only 2 lower neck fracture patients in the SEI group required a trocar. The other 13 subcondyle fractures were fixated with an angulated screw driver (P <0.05). There were no differences in complication and surgical outcomes.The submandibular endoscopic approach has an advantage of having more space with good visualization, and facilitated the use of an angulated screw driver.

Template-directed ligation of tethered mononucleotides by t4 DNA ligase for kinase ribozyme selection.

Directory of Open Access Journals (Sweden)

David G Nickens

Full Text Available BACKGROUND: In vitro selection of kinase ribozymes for small molecule metabolites, such as free nucleosides, will require partition systems that discriminate active from inactive RNA species. While nucleic acid catalysis of phosphoryl transfer is well established for phosphorylation of 5' or 2' OH of oligonucleotide substrates, phosphorylation of diffusible small molecules has not been demonstrated. METHODOLOGY/PRINCIPAL FINDINGS: This study demonstrates the ability of T4 DNA ligase to capture RNA strands in which a tethered monodeoxynucleoside has acquired a 5' phosphate. The ligation reaction therefore mimics the partition step of a selection for nucleoside kinase (deoxyribozymes. Ligation with tethered substrates was considerably slower than with nicked, fully duplex DNA, even though the deoxynucleotides at the ligation junction were Watson-Crick base paired in the tethered substrate. Ligation increased markedly when the bridging template strand contained unpaired spacer nucleotides across from the flexible tether, according to the trends: A(2>A(1>A(3>A(4>A(0>A(6>A(8>A(10 and T(2>T(3>T(4>T(6 approximately T(1>T(8>T(10. Bridging T's generally gave higher yield of ligated product than bridging A's. ATP concentrations above 33 microM accumulated adenylated intermediate and decreased yields of the gap-sealed product, likely due to re-adenylation of dissociated enzyme. Under optimized conditions, T4 DNA ligase efficiently (>90% joined a correctly paired, or TratioG wobble-paired, substrate on the 3' side of the ligation junction while discriminating approximately 100-fold against most mispaired substrates. Tethered dC and dG gave the highest ligation rates and yields, followed by tethered deoxyinosine (dI and dT, with the slowest reactions for tethered dA. The same kinetic trends were observed in ligase-mediated capture in complex reaction mixtures with multiple substrates. The "universal" analog 5-nitroindole (dNI did not support ligation when

STICS: surface-tethered iterative carbohydrate synthesis.

Science.gov (United States)

Pornsuriyasak, Papapida; Ranade, Sneha C; Li, Aixiao; Parlato, M Cristina; Sims, Charles R; Shulga, Olga V; Stine, Keith J; Demchenko, Alexei V

2009-04-14

A new surface-tethered iterative carbohydrate synthesis (STICS) technology is presented in which a surface functionalized 'stick' made of chemically stable high surface area porous gold allows one to perform cost efficient and simple synthesis of oligosaccharide chains; at the end of the synthesis, the oligosaccharide can be cleaved off and the stick reused for subsequent syntheses.

Hierarchical Structure in Semicrystalline Polymers Tethered to Nanospheres

KAUST Repository

Kim, Sung A; Archer, Lynden A.

2014-01-01

We report on structural and dynamic transitions of polymers tethered to nanoparticles. In particular, we use X-ray diffraction, vibrational spectroscopy, and thermal measurements to investigate multiscale structure and dynamic transitions of poly

Adhesive capsulitis of the shoulder: MR arthrography

International Nuclear Information System (INIS)

Kim, Hyun Jeong; Han, Tae Il; Lee, Kwang Won; Choi, Youn Seon; Kim, Dae Hong; Han, Hyun Young; Song, Mun Kab; Kwon, Soon Tae

2001-01-01

Adhesive capsulitis is a clinical syndrome involving pain and decreased joint motion caused by thickening and contraction of the joint capsule. The purpose of this study is to describe the MR arthrographic findings of this syndrome. Twenty-nine sets of MR arthrographic images were included in the study. Fourteen patients had adhesive capsulitis diagnosed by physical examination and arthrography, and their MR arthrographic findings were compared with those of 15 subjects in the control group. The images were retrospectively reviewed with specific attention to the thickness of the joint capsule, volume of the axillary pouch (length, width, height(depth)), thinkness of the coracohumeral ligament, presence of extra-articular contrast extravasation, and contrst filling of the subcoracoid bursa. Mean capsular thickness measured at the inferior portion of the axillary pouch was 4.1 mm in patients with adhesive capsulitis and 1.5 mm in the control group. The mean width of the axillary pouch was 2.5 mm in patients and 9.5 mm in controls. In patients, the capsule was significantly thicker and the axillary pouch significantly narrower than in controls (p<0.05). Capsule thickness greater than 2.5 mm at the inferior portion of the axillary pouch (sensitivity 93%, specificity 80%) and a pouch narrower than 3.5 mm (sensitivity 93%, specificity 100%) were useful criteria for the diagnosis of adhesive capsulitis. In patients with this condition, extra-articular contrast extravasation was noted in six patients (43%) and contrast filling of the subcoracoid bursa in three (21%). The MR arthrographic findings of adhesive capsulitis are capsular thickening, a low-volume axillary pouch, extra-articular contrast extravasation, and contrast filling of the subcoracoid bursa. Capsule thickness greater than 2.5 mm at the inferior portion of the axillary pouch and a pouch width of less than 3.5 mm are useful diagnostic imaging characteristics

Biomechanical simulations of costo-vertebral and anterior vertebral body tethers for the fusionless treatment of pediatric scoliosis.

Science.gov (United States)

Aubin, Carl-Éric; Clin, Julien; Rawlinson, Jeremy

2018-01-01

Compression-based fusionless tethers are an alternative to conventional surgical treatments of pediatric scoliosis. Anterior approaches place an anterior (ANT) tether on the anterolateral convexity of the deformed spine to modify growth. Posterior, or costo-vertebral (CV), approaches have not been assessed for biomechanical and corrective effectiveness. The objective was to biomechanically assess CV and ANT tethers using six patient-specific, finite element models of adolescent scoliotic patients (11.9 ± 0.7 years, Cobb 34° ± 10°). A validated algorithm simulated the growth and Hueter-Volkmann growth modulation over a period of 2 years with the CV and ANT tethers at two initial tensions (100, 200 N). The models without tethering also simulated deformity progression with Cobb angle increasing from 34° to 56°, axial rotation 11° to 13°, and kyphosis 28° to 32° (mean values). With the CV tether, the Cobb angle was reduced to 27° and 20° for tensions of 100 and 200 N, respectively, kyphosis to 21° and 19°, and no change in axial rotation. With the ANT tether, Cobb was reduced to 32° and 9° for 100 and 200 N, respectively, kyphosis unchanged, and axial rotation to 3° and 0°. While the CV tether mildly corrected the coronal curve over a 2-year growth period, it had sagittal lordosing effect, particularly with increasing initial axial rotation (>15°). The ANT tether achieved coronal correction, maintained kyphosis, and reduced the axial rotation, but over-correction was simulated at higher initial tensions. This biomechanical study captured the differences between a CV and ANT tether and indicated the variability arising from the patient-specific characteristics. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:254-264, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Manipulating neuronal circuits with endogenous and recombinant cell-surface tethered modulators

Directory of Open Access Journals (Sweden)

Mandë Holford

2009-10-01

Full Text Available Neuronal circuits depend on the precise regulation of cell-surface receptors and ion channels. An ongoing challenge in neuroscience research is deciphering the functional contribution of specific receptors and ion channels using engineered modulators. A novel strategy, termed “tethered toxins”, was recently developed to characterize neuronal circuits using the evolutionary derived selectivity of venom peptide toxins and endogenous peptide ligands, such as lynx1 prototoxins. Herein, the discovery and engineering of cell-surface tethered peptides is reviewed, with particular attention given to their cell-autonomy, modular composition, and genetic targeting in different model organisms. The relative ease with which tethered peptides can be engineered, coupled with the increasing number of neuroactive venom toxins and ligand peptides being discovered, imply a multitude of potentially innovative applications for manipulating neuronal circuits and tissue-specific cell networks, including treatment of disorders caused by malfunction of receptors and ion channels.

Reinforcing effects of caffeine in coffee and capsules.

Science.gov (United States)

Griffiths, R R; Bigelow, G E; Liebson, I A

1989-09-01

In a residential research ward the reinforcing and subjective effects of caffeine were studied under double-blind conditions in volunteer subjects with histories of heavy coffee drinking. In Experiment 1, 6 subjects had 13 opportunities each day to self-administer either a caffeine (100 mg) or a placebo capsule for periods of 14 to 61 days. All subjects developed a clear preference for caffeine, with intake of caffeine becoming relatively stable after preference had been attained. Preference for caffeine was demonstrated whether or not preference testing was preceded by a period of 10 to 37 days of caffeine abstinence, suggesting that a recent history of heavy caffeine intake (tolerance/dependence) was not a necessary condition for caffeine to function as a reinforcer. In Experiment 2, 6 subjects had 10 opportunities each day to self-administer a cup of coffee or (on different days) a capsule, dependent upon completing a work requirement that progressively increased and then decreased over days. Each day, one of four conditions was studied: caffeinated coffee (100 mg/cup), decaffeinated coffee, caffeine capsules (100 mg/capsule), or placebo capsules. Caffeinated coffee maintained the most self-administration, significantly higher than decaffeinated coffee and placebo capsules but not different from caffeine capsules. Both decaffeinated coffee and caffeine capsules were significantly higher than placebo capsules but not different from each other. In both experiments, subject ratings of "linking" of coffee or capsules covaried with the self-administration measures. These experiments provide the clearest demonstrations to date of the reinforcing effects of caffeine in capsules and in coffee.

Position Control of an X4-Flyer Using a Tether

Directory of Open Access Journals (Sweden)

Yusuke Ouchi

2016-05-01

Full Text Available In Japan, aging of infrastructures, such as roads,bridges, and water and sewer services, etc. poses a problem, andit is required to extend the life-span of such infrastructures bymaintenance. Among infrastructures, especially bridges areperiodically inspected by short range visual observations, whichcheck the damage and deterioration of the surface. However,since there are some cases where the short range visualobservation is difficult, an alternative method is required so as toreplace the short range visual observation with it. So, "X4-Flyer"is very attractive because of realizing a movement at high altitudeeasily. The objective of this study is to develop a tethered X4-Flyer, so that the conventional short range visual observation ofbridges is replaced by it. In this paper, a method for themeasurement and control of the position is described by using atether for controlling the position of the X4-Flyer. In addition, itis checked whether the tethered X4-Flyer can control the positionusing the proposed method or not, letting it fly in a state in whicha tether is being attached

Tethered elevator: A unique opportunity for space processing

Science.gov (United States)

Monti, R.

1986-01-01

The latest fluid dynamic and material science experiments in the microgravity environment have emphasized the importance of the residual gravity level and of the g-jitter on fluid physics phenomena. The tethered elevator presents the possibility of providing variable g-levels (both steady and g-jitter) around a very low steady g-level (that can be realized when the elevator is near the center of mass of the space station-tether complex). When positioning a variable periodic oscillation to the payload a clean g-jitter disturbance can be obtained that would not be otherwise obtainable by other systems. These two possibilities make the elevator a facility to help resolve a number of still open questions that are preventing wider utilization of the space environment in the microgravity area.

Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

KAUST Repository

Srivastava, Samanvaya; Agarwal, Praveen; Archer, Lynden A.

2012-01-01

different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer

A New Family of Capsule Polymerases Generates Teichoic Acid-Like Capsule Polymers in Gram-Negative Pathogens.

Science.gov (United States)

Litschko, Christa; Oldrini, Davide; Budde, Insa; Berger, Monika; Meens, Jochen; Gerardy-Schahn, Rita; Berti, Francesco; Schubert, Mario; Fiebig, Timm

2018-05-29

Group 2 capsule polymers represent crucial virulence factors of Gram-negative pathogenic bacteria. They are synthesized by enzymes called capsule polymerases. In this report, we describe a new family of polymerases that combine glycosyltransferase and hexose- and polyol-phosphate transferase activity to generate complex poly(oligosaccharide phosphate) and poly(glycosylpolyol phosphate) polymers, the latter of which display similarity to wall teichoic acid (WTA), a cell wall component of Gram-positive bacteria. Using modeling and multiple-sequence alignment, we showed homology between the predicted polymerase domains and WTA type I biosynthesis enzymes, creating a link between Gram-negative and Gram-positive cell wall biosynthesis processes. The polymerases of the new family are highly abundant and found in a variety of capsule-expressing pathogens such as Neisseria meningitidis , Actinobacillus pleuropneumoniae , Haemophilus influenzae , Bibersteinia trehalosi , and Escherichia coli with both human and animal hosts. Five representative candidates were purified, their activities were confirmed using nuclear magnetic resonance (NMR) spectroscopy, and their predicted folds were validated by site-directed mutagenesis. IMPORTANCE Bacterial capsules play an important role in the interaction between a pathogen and the immune system of its host. During the last decade, capsule polymerases have become attractive tools for the production of capsule polymers applied as antigens in glycoconjugate vaccine formulations. Conventional production of glycoconjugate vaccines requires the cultivation of the pathogen and thus the highest biosafety standards, leading to tremendous costs. With regard to animal husbandry, where vaccines could avoid the extensive use of antibiotics, conventional production is not sufficiently cost-effective. In contrast, enzymatic synthesis of capsule polymers is pathogen-free and fast, offers high stereo- and regioselectivity, and works with high efficacy

Endoscopic resection of subepithelial tumors.

Science.gov (United States)

Schmidt, Arthur; Bauder, Markus; Riecken, Bettina; Caca, Karel

2014-12-16

Management of subepithelial tumors (SETs) remains challenging. Endoscopic ultrasound (EUS) has improved differential diagnosis of these tumors but a definitive diagnosis on EUS findings alone can be achieved in the minority of cases. Complete endoscopic resection may provide a reasonable approach for tissue acquisition and may also be therapeutic in case of malignant lesions. Small SET restricted to the submucosa can be removed with established basic resection techniques. However, resection of SET arising from deeper layers of the gastrointestinal wall requires advanced endoscopic methods and harbours the risk of perforation. Innovative techniques such as submucosal tunneling and full thickness resection have expanded the frontiers of endoscopic therapy in the past years. This review will give an overview about endoscopic resection techniques of SET with a focus on novel methods.

Dynamics Model for a Multi-Tethered Space-Based Interferometer

National Research Council Canada - National Science Library

Gates, Stephen

2000-01-01

.... Tether constitutive behavior is discussed. Prescribed motion of any system degrees of freedom is treated, and expressions for the corresponding constraint force/torque components are established.

Oxygen fugacity and piston cylinder capsule assemblies

Science.gov (United States)

Jakobsson, S.

2011-12-01

A double capsule assembly designed to control oxygen fugacity in piston cylinder experiments has been tested at 1200 °C and 10 kbar. The assembly consists of an outer Pt-capsule containing a solid buffer (Ni-NiO or Co-CoO plus H2O) and an inner AuPd-capsule containing the sample, H2O and a Pt-wire. To prevent direct contact with the buffer phases the AuPd-capsule is embedded in finely ground Al2O3 along with some coarser, fractured Al2O3 facilitating fluid inclusion formation. No water loss is observed in the sample even after 48 hrs but a slight increase in water content is observed in longer duration runs due to oxygen and hydrogen diffusion into the AuPd-capsule. Carbon from the furnace also diffuses through the outer Pt-capsule but reacts with H2O in the outer capsule to form CO2 and never reaches the inner capsule. Oxygen fugacity of runs in equilibrium with the Ni-NiO and Co-CoO buffers was measured by analyzing the Fe content of the Pt-wire in the sample1 and by analyzing Fe dissolved in the AuPd capsule2. The second method gives values that are in good agreement with established buffer whereas results from the first method are one half to one log units higher than the established values. References 1. E. Medard, C. A. McCammon, J. A. Barr, T. L. Grove, Am. Mineral. 93, 1838 (2008). 2. J. Barr, T. Grove, Contrib. Mineral. Petrol. 160, 631 (2010)

Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

KAUST Repository

Moganty, Surya S.

2010-10-22

A new class of solventless electrolytes was created by tethering ionic liquids to hard inorganic ZrO2 nanostructures (see picture; NIM=nanoscale ionic material). These hybrid fluids exhibit exceptional redox stability windows, excellent thermal stability, good lithium transference numbers, long-term interfacial stability in the presence of a lithium anode and, when doped with lithium salt, reasonable ionic conductivities.

A new robotic-assisted flexible endoscope with single-hand control: endoscopic submucosal dissection in the ex vivo porcine stomach.

Science.gov (United States)

Iwasa, Tsutomu; Nakadate, Ryu; Onogi, Shinya; Okamoto, Yasuharu; Arata, Jumpei; Oguri, Susumu; Ogino, Haruei; Ihara, Eikichi; Ohuchida, Kenoki; Akahoshi, Tomohiko; Ikeda, Tetsuo; Ogawa, Yoshihiro; Hashizume, Makoto

2018-04-17

Difficulties in endoscopic operations and therapeutic procedures seem to occur due to the complexity of operating the endoscope dial as well as difficulty in performing synchronized movements with both hands. We developed a prototype robotic-assisted flexible endoscope that can be controlled with a single hand in order to simplify the operation of the endoscope. The aim of this study was to confirm the operability of the robotic-assisted flexible endoscope (RAFE) by performing endoscopic submucosal dissection (ESD). Study 1: ESD was performed manually or with RAFE by an expert endoscopist in ex vivo porcine stomachs; six operations manually and six were performed with RAFE. The procedure time per unit circumferential length/area was calculated, and the results were statistically analyzed. Study 2: We evaluated how smoothly a non-endoscopist can move a RAFE compared to a manual endoscope by assessing the designated movement of the endoscope. Study 1: En bloc resection was achieved by ESD using the RAFE. The procedure time was gradually shortened with increasing experience, and the procedure time of ESD performed with the RAFE was not significantly different from that of ESD performed with a manual endoscope. Study 2: The time for the designated movement of the endoscope was significantly shorter with a RAFE than that with a manual endoscope as for a non-endoscopist. The RAFE that we developed enabled an expert endoscopist to perform the ESD procedure without any problems and allowed a non-endoscopist to control the endoscope more easily and quickly than a manual endoscope. The RAFE is expected to undergo further development.

System Dynamics and Feedforward Control for Tether-Net Space Robot System

Directory of Open Access Journals (Sweden)

Guang Zhai

2009-06-01

Full Text Available A new concept using flexible tether-net system to capture space debris is presented in this paper. With a mass point assumption the tether-net system dynamic model is established in orbital frame by applying Lagrange Equations. In order to investigate the net in-plane trajectories during after cast, the non-control R-bar and V-bar captures are simulated with ignoring the out-of-plane libration, the effect of in-plane libration on the trajectories of the capture net is demonstrated by simulation results. With an effort to damp the in-plane libration, the control scheme based on tether tension is investigated firstly, after that an integrated control scheme is proposed by introduced the thrusters into the system, the nonlinear close-loop dynamics is linearised by feedforward strategy, the simulation results show that feedforward controllor is effective for in-plane libration damping and enable the capture net to track an expected trajectory.

Vortex rings from Sphagnum moss capsules

Science.gov (United States)

Whitaker, Dwight; Strassman, Sam; Cha, Jung; Chang, Emily; Guo, Xinyi; Edwards, Joan

2010-11-01

The capsules of Sphagnum moss use vortex rings to disperse spores to suitable habitats many kilometers away. Vortex rings are created by the sudden release of pressurized air when the capsule ruptures, and are an efficient way to carry the small spores with low terminal velocities to heights where they can be carried by turbulent wind currents. We will present our computational model of these explosions, which are carried out using a 2-D large eddy simulation (LES) on FLUENT. Our simulations can reproduce the observed motion of the spore clouds observed from moss capsules with high-speed videos, and we will discuss the roles of bursting pressure, cap mass, and capsule morphology on the formation and quality of vortex rings created by this plant.

Capsule endoscopy in neoplastic diseases

Science.gov (United States)

Pennazio, Marco; Rondonotti, Emanuele; de Franchis, Roberto

2008-01-01

Until recently, diagnosis and management of small-bowel tumors were delayed by the difficulty of access to the small bowel and the poor diagnostic capabilities of the available diagnostic techniques. An array of new methods has recently been developed, increasing the possibility of detecting these tumors at an earlier stage. Capsule endoscopy (CE) appears to be an ideal tool to recognize the presence of neoplastic lesions along this organ, since it is non-invasive and enables the entire small bowel to be visualized. High-quality images of the small-bowel mucosa may be captured and small and flat lesions recognized, without exposure to radiation. Recent studies on a large population of patients undergoing CE have reported small-bowel tumor frequency only slightly above that reported in previous surgical series (range, 1.6%-2.4%) and have also confirmed that the main clinical indication to CE in patients with small-bowel tumors is obscure gastrointestinal (GI) bleeding. The majority of tumors identified by CE are malignant; many were unsuspected and not found by other methods. However, it remains difficult to identify pathology and tumor type based on the lesion’s endoscopic appearance. Despite its limitations, CE provides crucial information leading in most cases to changes in subsequent patient management. Whether the use of CE in combination with other new diagnostic (MRI or multidetector CT enterography) and therapeutic (Push-and-pull enteroscopy) techniques will lead to earlier diagnosis and treatment of these neoplasms, ultimately resulting in a survival advantage and in cost savings, remains to be determined through carefully-designed studies. PMID:18785274

[Evaluation of nopal capsules in diabetes mellitus].

Science.gov (United States)

Frati Munari, A C; Vera Lastra, O; Ariza Andraca, C R

1992-01-01

To find out if commercial capsules with dried nopal (prickle-pear cactus, Opuntia ficus indica may have a role in the management of diabetes mellitus, three experiments were performed: 30 capsules where given in fasting condition to 10 diabetic subjects and serum glucose was measured through out 3 hours; a control test was performed with 30 placebo capsules. OGTT with previous intake of 30 nopal or placebo capsules was performed in ten healthy individuals. In a crossover and single blinded study 14 diabetic patients withdrew the oral hypoglycemic treatment and received 10 nopal or placebo capsules t.i.d. during one week; serum glucose, cholesterol and tryglycerides levels were measured before and after each one-week period. Five healthy subjects were also studied in the same fashion. Opuntia capsules did not show acute hypoglycemic effect and did not influence OGTT. In diabetic patients serum glucose, cholesterol and tryglycerides levels did not change with Opuntia, but they increased with placebo (P nopal, while cholesterol and triglycerides decreased (P < 0.01 vs. placebo). The intake of 30 Opuntia capsules daily in patients with diabetes mellitus had a discrete beneficial effect on glucose and cholesterol. However this dose is unpractical and at present it is not recommended in the management of diabetes mellitus.

Application of the NASCAP Spacecraft Simulation Tool to Investigate Electrodynamic Tether Current Collection in LEO

Science.gov (United States)

Adams, Mitzi; HabashKrause, Linda

2012-01-01

Recent interest in using electrodynamic tethers (EDTs) for orbital maneuvering in Low Earth Orbit (LEO) has prompted the development of the Marshall ElectroDynamic Tether Orbit Propagator (MEDTOP) model. The model is comprised of several modules which address various aspects of EDT propulsion, including calculation of state vectors using a standard orbit propagator (e.g., J2), an atmospheric drag model, realistic ionospheric and magnetic field models, space weather effects, and tether librations. The natural electromotive force (EMF) attained during a radially-aligned conductive tether results in electrons flowing down the tether and accumulating on the lower-altitude spacecraft. The energy that drives this EMF is sourced from the orbital energy of the system; thus, EDTs are often proposed as de-orbiting systems. However, when the current is reversed using satellite charged particle sources, then propulsion is possible. One of the most difficult challenges of the modeling effort is to ascertain the equivalent circuit between the spacecraft and the ionospheric plasma. The present study investigates the use of the NASA Charging Analyzer Program (NASCAP) to calculate currents to and from the tethered satellites and the ionospheric plasma. NASCAP is a sophisticated set of computational tools to model the surface charging of three-dimensional (3D) spacecraft surfaces in a time-varying space environment. The model's surface is tessellated into a collection of facets, and NASCAP calculates currents and potentials for each one. Additionally, NASCAP provides for the construction of one or more nested grids to calculate space potential and time-varying electric fields. This provides for the capability to track individual particles orbits, to model charged particle wakes, and to incorporate external charged particle sources. With this study, we have developed a model of calculating currents incident onto an electrodynamic tethered satellite system, and first results are shown

Submucosal tunnel endoscopy: Peroral endoscopic myotomy and peroral endoscopic tumor resection

Science.gov (United States)

Eleftheriadis, Nikolas; Inoue, Haruhiro; Ikeda, Haruo; Onimaru, Manabu; Maselli, Roberta; Santi, Grace

2016-01-01

Peroral endoscopic myotomy (POEM) is an innovative, minimally invasive, endoscopic treatment for esophageal achalasia and other esophageal motility disorders, emerged from the natural orifice transluminal endoscopic surgery procedures, and since the first human case performed by Inoue in 2008, showed exciting results in international level, with more than 4000 cases globally up to now. POEM showed superior characteristics than the standard 100-year-old surgical or laparoscopic Heller myotomy (LHM), not only for all types of esophageal achalasia [classical (I), vigorous (II), spastic (III), Chicago Classification], but also for advanced sigmoid type achalasia (S1 and S2), failed LHM, or other esophageal motility disorders (diffuse esophageal spasm, nutcracker esophagus or Jackhammer esophagus). POEM starts with a mucosal incision, followed by submucosal tunnel creation crossing the esophagogastric junction (EGJ) and myotomy. Finally the mucosal entry is closed with endoscopic clip placement. POEM permitted relatively free choice of myotomy length and localization. Although it is technically demanding procedure, POEM can be performed safely and achieves very good control of dysphagia and chest pain. Gastroesophageal reflux is the most common troublesome side effect, and is well controllable with proton pump inhibitors. Furthermore, POEM opened the era of submucosal tunnel endoscopy, with many other applications. Based on the same principles with POEM, in combination with new technological developments, such as endoscopic suturing, peroral endoscopic tumor resection (POET), is safely and effectively applied for challenging submucosal esophageal, EGJ and gastric cardia tumors (submucosal tumors), emerged from muscularis propria. POET showed up to know promising results, however, it is restricted to specialized centers. The present article reviews the recent data of POEM and POET and discussed controversial issues that need further study and future perspectives. PMID

Design and fabrication of non-instrumented capsule

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Sung; Lee, Jeong Young; Kim, Joon Yeon; Lee, Sung Ho; Ji, Dae Young; Kim, Suk Hoon; Ahn, Sung Ho [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-04-01

The use of non-instrumented capsule designed and fabricated in this time is for the evaluation of material irradiation performance, it is to be installed in the inner core of HANARO. The design process of non-instrumented capsule was accomplished by the decision of the quality of material and the shape, thermal analysis, structural analysis. The temperature of the specimen and the stress in capsule during irradiation test was calculated by the thermal analysis and the structural analysis. GGENGTC code and ABAQUS code were used for the calculation of non-instrumented capsule. In case of installing the capsule in irradiation hole, the coolant flow rate and the pressure drop in the hole is changed, which will affect the coolant flow rate of the fuel region. Eventually the coolant flow rate outside capsule have to be restricted to the allowable range. In order to obtain the required pressure drop, the flow rate control mechanism, end plate and orifice ring were used in this test. The test results are compared with 36-element fuel pressure drop data which AECL performed by the SCTR facility.

Design and fabrication of non-instrumented capsule

International Nuclear Information System (INIS)

Kim, Yong Sung; Lee, Jeong Young; Kim, Joon Yeon; Lee, Sung Ho; Ji, Dae Young; Kim, Suk Hoon; Ahn, Sung Ho

1995-04-01

The use of non-instrumented capsule designed and fabricated in this time is for the evaluation of material irradiation performance, it is to be installed in the inner core of HANARO. The design process of non-instrumented capsule was accomplished by the decision of the quality of material and the shape, thermal analysis, structural analysis. The temperature of the specimen and the stress in capsule during irradiation test was calculated by the thermal analysis and the structural analysis. GGENGTC code and ABAQUS code were used for the calculation of non-instrumented capsule. In case of installing the capsule in irradiation hole, the coolant flow rate and the pressure drop in the hole is changed, which will affect the coolant flow rate of the fuel region. Eventually the coolant flow rate outside capsule have to be restricted to the allowable range. In order to obtain the required pressure drop, the flow rate control mechanism, end plate and orifice ring were used in this test. The test results are compared with 36-element fuel pressure drop data which AECL performed by the SCTR facility

Long distance cell communication using spherical tether balloons

Science.gov (United States)

Manchanda, R. K.; Rajagopalan, Vasudevan; Vasudevan, Rajagopalan; Mehrotra, R. K.; Sreenivasan, S.; Pawaskar, M.; Subba Rao Jonnalagadda, Venkata; Buduru, Suneelkumar; Kulkarni, P. M.

A proof-of-concept experiment was conducted for long-range cell communication for rural tele-phony and internet. We designed and fabricated a spherical tether balloon to carry the con-ventional micro base transceiver station (BTS) along with three slotted antenna to cover 2-pi radius. AC power and optical fiber were anchored along with the tether line. A special fre-quency license was obtained from Wireless Planning Commission (WPC) wing of Department of Telecommunication (DoT), India for the period of experiment so as not to affect the opera-tional networks. The experiments were carried out for different BTS heights up to 500 meter. Signal measurement both in data mode and voice quality were done in different quadrant using mobile vans. This paper describes the methodology (under patenting) and utility of technique for operational application.

Endoscopic approaches to treatment of achalasia

Science.gov (United States)

Friedel, David; Modayil, Rani; Iqbal, Shahzad; Grendell, James H.

2013-01-01

Endoscopic therapy for achalasia is directed at disrupting or weakening the lower esophageal sphincter (LES). The two most commonly utilized endoscopic interventions are large balloon pneumatic dilation (PD) and botulinum toxin injection (BTI). These interventions have been extensively scrutinized and compared with each other as well as with surgical disruption (myotomy) of the LES. PD is generally more effective in improving dysphagia in achalasia than BTI, with the latter reserved for infirm older people, and PD may approach treatment results attained with myotomy. However, PD may need to be repeated. Small balloon dilation and endoscopic stent placement for achalasia have only been used in select centers. Per oral endoscopic myotomy is a newer endoscopic modality that will likely change the treatment paradigm for achalasia. It arose from the field of natural orifice transluminal endoscopic surgery and represents a scarless endoscopic approach to Heller myotomy. This is a technique that requires extensive training and preparation and thus there should be rigorous accreditation and monitoring of outcomes to ensure safety and efficacy. PMID:23503707

Tethered "kiteplane" design for the Laddermill project

NARCIS (Netherlands)

Breukels, J.; Ockels, W.

2005-01-01

The Laddermill is an innovative concept for generating energy from wind using large kite-like wings on a tether. The wings are able to fly in both the regime of airplanes and kites. We therefore call these structures "kiteplanes". By providing a recurring motion with a large lift during ascending

Time Series Analysis of the Effectiveness and Safety of Capsule Endoscopy between the Premarketing and Postmarketing Settings: A Meta-Analysis.

Directory of Open Access Journals (Sweden)

Kazuo Iijima

Full Text Available Clinical studies for assessing the effectiveness and safety in a premarketing setting are conducted under time and cost constraints. In recent years, postmarketing data analysis has been given more attention. However, to our knowledge, no studies have compared the effectiveness and the safety between the pre- and postmarketing settings. In this study, we aimed to investigate the importance of the postmarketing data analysis using clinical data.Studies on capsule endoscopy with rich clinical data in both pre- and postmarketing settings were selected for the analysis. For effectiveness, clinical studies published before October 10, 2015 comparing capsule endoscopy and conventional flexible endoscopy measuring the detection ratio of obscure gastrointestinal bleeding were selected (premarketing: 4 studies and postmarketing: 8 studies from PubMed (MEDLINE, Cochrane Library, EMBASE and Web of Science. Among the 12 studies, 5 were blinded and 7 were non-blinded. A time series meta-analysis was conducted. Effectiveness (odds ratio decreased in the postmarketing setting (premarketing: 5.19 [95% confidence interval: 3.07-8.76] vs. postmarketing: 1.48 [0.81-2.69]. The change in odds ratio was caused by the increase in the detection ratio with flexible endoscopy as the control group. The efficacy of capsule endoscopy did not change between pre- and postmarketing settings. Heterogeneity (I2 increased in the postmarketing setting because of one study. For safety, in terms of endoscope retention in the body, data from the approval summary and adverse event reports were analyzed. The incidence of retention decreased in the postmarketing setting (premarketing: 0.75% vs postmarketing: 0.095%. The introduction of the new patency capsule for checking the patency of the digestive tract might contribute to the decrease.Effectiveness and safety could change in the postmarketing setting. Therefore, time series meta-analyses could be useful to continuously monitor the

[Endoscopic extraction of gallbladder calculi].

Science.gov (United States)

Kühner, W; Frimberger, E; Ottenjann, R

1984-06-29

Endoscopic extraction of gallbladder stones were performed, as far as we know for the first time, in three patients with combined choledochocystolithiasis. Following endoscopic papillotomy (EPT) and subsequent mechanical lithotripsy of multiple choledochal concrements measuring up to 3 cm the gallbladder stones were successfully extracted with a Dormia basket through the cystic duct. The patients have remained free of complications after the endoscopic intervention.

Capsule endoscopy—A mechatronics perspective

Science.gov (United States)

Lin, Lin; Rasouli, Mahdi; Kencana, Andy Prima; Tan, Su Lim; Wong, Kai Juan; Ho, Khek Yu; Phee, Soo Jay

2011-03-01

The recent advances in integrated circuit technology, wireless communication, and sensor technology have opened the door for development of miniature medical devices that can be used for enhanced monitoring and treatment of medical conditions. Wireless capsule endoscopy is one of such medical devices that has gained significant attention during the past few years. It is envisaged that future wireless capsule endoscopies replace traditional endoscopy procedures by providing advanced functionalities such as active locomotion, body fluid/tissue sampling, and drug delivery. Development of energy-efficient miniaturized actuation mechanisms is a key step toward achieving this goal. Here, we review some of the actuators that could be integrated into future wireless capsules and discuss the existing challenges.

Isolation of Capsulate Bacteria from Acute Dentoalveolar Abscesses

OpenAIRE

Lewis, M. A. O.; Milligan, S. G.; MacFarlane, T. W.; Carmichael, F. A.

2011-01-01

The presence of a capsule was determined for 198 bacterial strains (57 facultative anaerobes, 141 strict anaerobes) isobdted from pus samples aspirated from 40 acute dentoalveolar abscesses. A total of 133 (67 per cent) of the isolates (42 facultative anaerobes, 91 strict anaerobes) were found to have a capsule. Possession ofa capsule may in part explain the apparent pathogenicity of the bacterial species encountered in acute dentoalveolar abscess.Keywords - Bacterial capsule; Acute dentoalve...

Endoscopic findings following retroperitoneal pancreas transplantation.

Science.gov (United States)

Pinchuk, Alexey V; Dmitriev, Ilya V; Shmarina, Nonna V; Teterin, Yury S; Balkarov, Aslan G; Storozhev, Roman V; Anisimov, Yuri A; Gasanov, Ali M

2017-07-01

An evaluation of the efficacy of endoscopic methods for the diagnosis and correction of surgical and immunological complications after retroperitoneal pancreas transplantation. From October 2011 to March 2015, 27 patients underwent simultaneous retroperitoneal pancreas-kidney transplantation (SPKT). Diagnostic oesophagogastroduodenoscopy (EGD) with protocol biopsy of the donor and recipient duodenal mucosa and endoscopic retrograde pancreatography (ERP) were performed to detect possible complications. Endoscopic stenting of the main pancreatic duct with plastic stents and three-stage endoscopic hemostasis were conducted to correct the identified complications. Endoscopic methods showed high efficiency in the timely diagnosis and adequate correction of complications after retroperitoneal pancreas transplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Transanal endoscopic microsurgery versus endoscopic mucosal resection for large rectal adenomas (TREND-study)

NARCIS (Netherlands)

F.J.C. van den Broek (Frank); E.J.R. de Graaf (Eelco); M.G.W. Dijkgraaf (Marcel); J.B. Reitsma (Johannes); J. Haringsma (Jelle); R. Timmer (Robin); B.L. Weusten (Bas); M.F. Gerhards (Michael); E.C. Consten (Esther); M.P. Schwartz (Matthijs); M.J. Boom (Maarten); E.J. Derksen (Erik); A.B. Bijnen (Bart); P.H.P. Davids (Paul); C. Hoff (Christiaan); H.M. van Dullemen (Hendrik); G.D.N. Heine (Dimitri); K. van der Linde (Klaas); J.M. Jansen (Jeroen); R.C.H. Mallant-Hent (Rosalie); R. Breumelhof (Ronald); H. Geldof (Han); J.C. Hardwick (James); P. Doornebosch (Pascal); A.C.T.M. Depla (Annekatrien); M.F. Ernst (Miranda); I.P. van Munster (Ivo); I.H.J.T. de Hingh (Ignace); E.J. Schoon (Erik); W.A. Bemelman (Willem); P. Fockens (Paul); E. Dekker (Evelien)

2009-01-01

textabstractBackground: Recent non-randomized studies suggest that extended endoscopic mucosal resection (EMR) is equally effective in removing large rectal adenomas as transanal endoscopic microsurgery (TEM). If equally effective, EMR might be a more cost-effective approach as this strategy does

Measurement of calcium influx in tethered rings of rabbit aorta under tension

International Nuclear Information System (INIS)

Gleason, M.M.; Ratz, P.H.; Flaim, S.F.

1985-01-01

Calcium (Ca) influx in vascular smooth muscle is routinely measured in untethered preparations not under passive stretch, and Ca influx data are correlated with data for steady-state isometric tension obtained under parallel conditions from tethered preparations under passive stretch. The validity of this method was tested by simultaneous measurement of Ca influx and tension in tethered rings of rabbit thoracic aorta. Ca influx ( 45 Ca 3-min pulse) and tension were measured at 3 and 30 min after norepinephrine (NE) or KCl and under control (no agonist) conditions. Active tension was significantly altered by variations in passive tension. Ca influx was unaffected by passive tension under control, NE, or KCl conditions, and results were similar at 3 and 30 min. The results confirm the validity of correlating Ca influx data from untethered rings with steady-state contractile response data obtained from tethered rings under similar experimental conditions

Differential Regulation of Synaptic Vesicle Tethering and Docking by UNC-18 and TOM-1.

Science.gov (United States)

Gracheva, Elena O; Maryon, Ed B; Berthelot-Grosjean, Martine; Richmond, Janet E

2010-01-01

The assembly of SNARE complexes between syntaxin, SNAP-25 and synaptobrevin is required to prime synaptic vesicles for fusion. Since Munc18 and tomosyn compete for syntaxin interactions, the interplay between these proteins is predicted to be important in regulating synaptic transmission. We explored this possibility, by examining genetic interactions between C. elegans unc-18(Munc18), unc-64(syntaxin) and tom-1(tomosyn). We have previously demonstrated that unc-18 mutants have reduced synaptic transmission, whereas tom-1 mutants exhibit enhanced release. Here we show that the unc-18 mutant release defect is associated with loss of two morphologically distinct vesicle pools; those tethered within 25 nm of the plasma membrane and those docked with the plasma membrane. In contrast, priming defective unc-13 mutants accumulate tethered vesicles, while docked vesicles are greatly reduced, indicating tethering is UNC-18-dependent and occurs in the absence of priming. C. elegans unc-64 mutants phenocopy unc-18 mutants, losing both tethered and docked vesicles, whereas overexpression of open syntaxin preferentially increases vesicle docking, suggesting UNC-18/closed syntaxin interactions are responsible for vesicle tethering. Given the competition between vertebrate tomosyn and Munc18, for syntaxin binding, we hypothesized that C. elegans TOM-1 may inhibit both UNC-18-dependent vesicle targeting steps. Consistent with this hypothesis, tom-1 mutants exhibit enhanced UNC-18 plasma membrane localization and a concomitant increase in both tethered and docked synaptic vesicles. Furthermore, in tom-1;unc-18 double mutants the docked, primed vesicle pool is preferentially rescued relative to unc-18 single mutants. Together these data provide evidence for the differential regulation of two vesicle targeting steps by UNC-18 and TOM-1 through competitive interactions with syntaxin.

Differential regulation of synaptic vesicle tethering and docking by UNC-18 and TOM-1

Directory of Open Access Journals (Sweden)

Elena O Gracheva

2010-10-01

Full Text Available The assembly of SNARE complexes between syntaxin, SNAP-25 and synaptobrevin is required to prime synaptic vesicles for fusion. Since Munc18 and tomosyn compete for syntaxin interactions, the interplay between these proteins is predicted to be important in regulating synaptic transmission. We explored this possibility, by examining genetic interactions between C. elegans unc-18(Munc18, unc-64(syntaxin and tom-1(tomosyn. We have previously demonstrated that unc-18 mutants have reduced synaptic transmission, whereas tom-1 mutants exhibit enhanced release. Here we show that the unc-18 mutant release defect is associated with loss of two morphologically distinct vesicle pools; those tethered within 25nm of the plasma membrane and those docked with the plasma membrane. In contrast, priming defective unc-13 mutants accumulate tethered vesicles, while docked vesicles are greatly reduced, indicating tethering is UNC-18-dependent and occurs in the absence of priming. C. elegans unc-64 mutants phenocopy unc-18 mutants, losing both tethered and docked vesicles, whereas overexpression of open syntaxin preferentially increases vesicle docking, suggesting UNC-18/closed syntaxin interactions are responsible for vesicle tethering. Given the competition between vertebrate tomosyn and Munc18, for syntaxin binding, we hypothesized that C. elegans TOM-1 may inhibit both UNC-18-dependent vesicle targeting steps. Consistent with this hypothesis, tom-1 mutants exhibit enhanced UNC-18 plasma membrane localization and a concomitant increase in both tethered and docked synaptic vesicles. Furthermore, in tom-1;unc-18 double mutants the docked, primed vesicle pool is preferentially rescued relative to unc-18 single mutants. Together these data provide evidence for the differential regulation of two vesicle targeting steps by UNC-18 and TOM-1 through competitive interactions with syntaxin

Acquisition of Ice-Tethered Profilers with Velocity (ITP-V) Instruments for Future Arctic Studies

Science.gov (United States)

2016-11-15

San Diego, CA, IEEE Xplore . Toole, J. M., R. A. Krishfield, M.-L. Timmennans, and A. Proshutinsky, 2011: The Ice-Tethered Profiler: Argo ofthe Arctic, Oceanogr., 24, 126-135. 4 ...observations from Ice-Tethered Profilers, MTS/ IEEE Oceans’ 2015, Washington DC, 1-10. Krishfield, R., J. Toole, A. Proshutinsky, and M.-L. Timmennans, 2008

Capsule Endoscopy

Science.gov (United States)

... because experience with it is limited and traditional upper endoscopy is widely available. Why it's done Your doctor might recommend a capsule endoscopy procedure to: Find the cause of gastrointestinal bleeding. If you have unexplained bleeding in your digestive ...

Orbital Propagation of Momentum Exchange Tether Systems

Science.gov (United States)

Westerhoff, John

2002-01-01

An advanced concept in in-space transportation currently being studied is the Momentum-Exchange/Electrodynamic Reboost Tether System (MXER). The system acts as a large momentum wheel, imparting a Av to a payload in low earth orbit (LEO) at the expense of its own orbital energy. After throwing a payload, the system reboosts itself using an electrodynamic tether to push against Earth's magnetic field and brings itself back up to an operational orbit to prepare for the next payload. The ability to reboost itself allows for continued reuse of the system without the expenditure of propellants. Considering the cost of lifting propellant from the ,ground to LEO to do the same Av boost at $10000 per pound, the system cuts the launch cost of the payload dramatically, and subsequently, the MXER system pays for itself after a small number of missions.1 One of the technical hurdles to be overcome with the MXER concept is the rendezvous maneuver. The rendezvous window for the capture of the payload is on the order of a few seconds, as opposed to traditional docking maneuvers, which can take as long ets necessary to complete a precise docking. The payload, therefore, must be able to match its orbit to meet up with the capture device on the end of the tether at a specific time and location in the future. In order to be able to determine that location, the MXER system must be numerically propagated forward in time to predict where the capture device will be at that instant. It should be kept in mind that the propagation computation must be done faster than real-time. This study focuses on the efforts to find and/or build the tools necessary to numerically propagate the motion of the MXER system as accurately as possible.

Space webs based on rotating tethered formations

Science.gov (United States)

Palmerini, Giovanni B.; Sgubini, Silvano; Sabatini, Marco

2009-07-01

Several on-going studies indicate the interest for large, light orbiting structures, shaped as fish nets or webs: along the ropes of the web small spacecraft can move like spiders to position and re-locate, at will, pieces of hardware devoted to specific missions. The concept could be considered as an intermediate solution between the large monolithic structure, heavy and expensive to realize, but easy to control, and the formations of satellites, where all system members are completely free and should manoeuvre in order to acquire a desired configuration. Instead, the advantage of having a "hard-but-light" link among the different grids lays in the partition of the tasks among system components and in a possible overall reduction of the control system complexity and cost. Unfortunately, there is no stable configuration for an orbiting, two-dimensional web made by light, flexible tethers which cannot support compression forces. A possible solution is to make use of centrifugal forces to pull the net, with a reduced number of simple thrusters located at the tips of the tethers to initially acquire the required spin. In this paper a dynamic analysis of a simplified rotating web is performed, in order to evaluate the spinning velocity able to satisfy the requirement for the stability of the system. The model adopted overlaps simpler elements, each of them given by a tether (made up of a number of linear finite elements) connecting two extreme bodies accommodating the spinning thrusters. The combination of these "diameter-like" elements provides the web, shaped according to the specific requirements. The net is primarily considered as subjected to Keplerian attraction and J2 and drag perturbations only, but its behaviour under thermal inputs is also investigated.

Capsule development and utilization for material irradiation tests

Energy Technology Data Exchange (ETDEWEB)

Kang, Young Hwan; Kim, B G; Joo, K N [and others

2000-05-01

The development program of advanced nuclear structural and fuel materials includes the in-pile tests using the instrumented capsule at HANARO. The tests were performed in the in-core test holes of CT, IR 1 and 2 and OR 4 and 5 of HANARO. Extensive efforts have also been made to establish design and manufacturing technology for the instrumented capsule and its related system, which should be compatible with the HANARO's characteristics. Since the first instrumented capsule(97M-01K) had been designed and successfully fabricated, five tests were done to support the users and provided the economic benefits to user by generating the essential in-pile information on the performance and structural integrity of materials. This paper describes the present status and future plans of these R and D activities for the development of the instrumented capsule including in-situ material property measurement capsules and nuclear fuel test capsules.

Capsule development and utilization for material irradiation tests

International Nuclear Information System (INIS)

Kang, Young Hwan; Kim, B. G.; Joo, K. N.

2000-05-01

The development program of advanced nuclear structural and fuel materials includes the in-pile tests using the instrumented capsule at HANARO. The tests were performed in the in-core test holes of CT, IR 1 and 2 and OR 4 and 5 of HANARO. Extensive efforts have also been made to establish design and manufacturing technology for the instrumented capsule and its related system, which should be compatible with the HANARO's characteristics. Since the first instrumented capsule(97M-01K) had been designed and successfully fabricated, five tests were done to support the users and provided the economic benefits to user by generating the essential in-pile information on the performance and structural integrity of materials. This paper describes the present status and future plans of these R and D activities for the development of the instrumented capsule including in-situ material property measurement capsules and nuclear fuel test capsules

Current Status and Research into Overcoming Limitations of Capsule Endoscopy

Directory of Open Access Journals (Sweden)

Won Gun Kwack

2016-01-01

Full Text Available Endoscopic investigation has a critical role in the diagnosis and treatment of gastrointestinal (GI diseases. Since 2001, capsule endoscopy (CE has been available for small-bowel exploration and is under continuous development. During the past decade, CE has achieved impressive improvements in areas such as miniaturization, resolution, and battery life. As a result, CE is currently a first-line tool for the investigation of the small bowel in obscure gastrointestinal bleeding and is a useful alternative to wired enteroscopy. Nevertheless, CE still has several limitations, such as incomplete examination and limited diagnostic and therapeutic capabilities. To resolve these problems, many groups have suggested several models (e.g., controlled CO2 insufflation system, magnetic navigation system, mobile robotic platform, tagging and biopsy equipment, and targeted drug-delivery system, which are in development. In the near future, new technological advances will improve the capabilities of CE and broaden its spectrum of applications not only for the small bowel but also for the colon, stomach, and esophagus. The purpose of this review is to introduce the current status of CE and to review the ongoing development of solutions to address its limitations.

Transanal endoscopic microsurgery versus endoscopic mucosal resection for large rectal adenomas (TREND-study)

NARCIS (Netherlands)

van den Broek, Frank J. C.; de Graaf, Eelco J. R.; Dijkgraaf, Marcel G. W.; Haringsma, Jelle; Timmer, Robin; Weusten, Bas L. A. M.; Gerhards, Michael F.; Consten, Esther C. J.; Schwartz, Matthijs P.; Boom, Maarten J.; Derksen, Erik J.; Bijnen, A. Bart; Davids, Paul H. P.; Hoff, Christiaan; van Dullemen, Hendrik M.; Heine, G. Dimitri N.; van der Linde, Klaas; Jansen, Jeroen M.; Mallant-Hent, Rosalie C. H.; Breumelhof, Ronald; Geldof, Han; Hardwick, James C. H.; Doornebosch, Pascal G.; Depla, Annekatrien C. T. M.; Ernst, Miranda F.; van Munster, Ivo P.; de Hingh, Ignace H. J. T.; Schoon, Erik J.; Bemelman, Willem A.; Fockens, Paul; Dekker, Evelien; Reitsma, J.

2009-01-01

Background: Recent non-randomized studies suggest that extended endoscopic mucosal resection (EMR) is equally effective in removing large rectal adenomas as transanal endoscopic microsurgery (TEM). If equally effective, EMR might be a more cost-effective approach as this strategy does not require

[Endoscopic full-thickness resection].

Science.gov (United States)

Meier, B; Schmidt, A; Caca, K

2016-08-01

Conventional endoscopic resection techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are powerful tools for the treatment of gastrointestinal (GI) neoplasms. However, those techniques are limited to the superficial layers of the GI wall (mucosa and submucosa). Lesions without lifting sign (usually arising from deeper layers) or lesions in difficult anatomic positions (appendix, diverticulum) are difficult - if not impossible - to resect using conventional techniques, due to the increased risk of complications. For larger lesions (>2 cm), ESD appears to be superior to the conventional techniques because of the en bloc resection, but the procedure is technically challenging, time consuming, and associated with complications even in experienced hands. Since the development of the over-the-scope clips (OTSC), complications like bleeding or perforation can be endoscopically better managed. In recent years, different endoscopic full-thickness resection techniques came to the focus of interventional endoscopy. Since September 2014, the full-thickness resection device (FTRD) has the CE marking in Europe for full-thickness resection in the lower GI tract. Technically the device is based on the OTSC system and combines OTSC application and snare polypectomy in one step. This study shows all full-thickness resection techniques currently available, but clearly focuses on the experience with the FTRD in the lower GI tract.

Adsorption and desorption of phosphorus in ceramic capsules

International Nuclear Information System (INIS)

Almeida, J.R.F. de.

1983-01-01

Experiments were carried out in order to analyse the capacity of adsorving P from water using ceramic capsules with 32P, in the presence and absence of water flow through the capsule. Also studied was the desorption of 32 P from the capsule in water, with and without water flow. The desorption of residual 32 P was analysed by isotopic exchange with 31 P, also with and without water flow. It was observed that, in the presence of a flow, the capsule retained 32 P from the solution, which was weakly desorbed by water but was isotopically exchanged with 31 P. In the absence of a flow, the capsule was not an efficient P adsorber. (Author) [pt

Endoscopic full-thickness resection: Current status.

Science.gov (United States)

Schmidt, Arthur; Meier, Benjamin; Caca, Karel

2015-08-21

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

Production, deformation and mechanical investigation of magnetic alginate capsules

Science.gov (United States)

Zwar, Elena; Kemna, Andre; Richter, Lena; Degen, Patrick; Rehage, Heinz

2018-02-01

In this article we investigated the deformation of alginate capsules in magnetic fields. The sensitivity to magnetic forces was realised by encapsulating an oil in water emulsion, where the oil droplets contained dispersed magnetic nanoparticles. We solved calcium ions in the aqueous emulsion phase, which act as crosslinking compounds for forming thin layers of alginate membranes. This encapsulating technique allows the production of flexible capsules with an emulsion as the capsule core. It is important to mention that the magnetic nanoparticles were stable and dispersed throughout the complete process, which is an important difference to most magnetic alginate-based materials. In a series of experiments, we used spinning drop techniques, capsule squeezing experiments and interfacial shear rheology in order to determine the surface Young moduli, the surface Poisson ratios and the surface shear moduli of the magnetically sensitive alginate capsules. In additional experiments, we analysed the capsule deformation in magnetic fields. In spinning drop and capsule squeezing experiments, water droplets were pressed out of the capsules at elevated values of the mechanical load. This phenomenon might be used for the mechanically triggered release of water-soluble ingredients. After drying the emulsion-filled capsules, we produced capsules, which only contained a homogeneous oil phase with stable suspended magnetic nanoparticles (organic ferrofluid). In the dried state, the thin alginate membranes of these particles were rather rigid. These dehydrated capsules could be stored at ambient conditions for several months without changing their properties. After exposure to water, the alginate membranes rehydrated and became flexible and deformable again. During this swelling process, water diffused back in the capsule. This long-term stability and rehydration offers a great spectrum of different applications as sensors, soft actuators, artificial muscles or drug delivery systems.

Novel methods for endoscopic training.

Science.gov (United States)

Gessner, C E; Jowell, P S; Baillie, J

1995-04-01

The development of past, present, and future endoscopic training methods is described. A historical perspective of endoscopy training guidelines and devices is used to demonstrate support for the use of novel endoscopic training techniques. Computer simulation of endoscopy, interactive learning, and virtual reality applications in endoscopy and surgery are reviewed. The goals of endoscopic simulation and challenges facing investigators in this field are discussed, with an emphasis on current and future research.

Capsule endoscopy: Beyond small bowel

Directory of Open Access Journals (Sweden)

Samuel N Adler

2012-01-01

Full Text Available In this article the brief and dramatic history of capsule endoscopy of the digestive tract is reviewed. Capsule endoscopy offers a non invasive method to diagnose diseases that affect the esophagus, small bowel and colon. Technological improvements relating to optics, software, data recorders with two way communication have revolutionized this field. These advancements have produced better diagnostic performance.

The shear flow processing of controlled DNA tethering and stretching for organic molecular electronics.

Science.gov (United States)

Yu, Guihua; Kushwaha, Amit; Lee, Jungkyu K; Shaqfeh, Eric S G; Bao, Zhenan

2011-01-25

DNA has been recently explored as a powerful tool for developing molecular scaffolds for making reproducible and reliable metal contacts to single organic semiconducting molecules. A critical step in the process of exploiting DNA-organic molecule-DNA (DOD) array structures is the controlled tethering and stretching of DNA molecules. Here we report the development of reproducible surface chemistry for tethering DNA molecules at tunable density and demonstrate shear flow processing as a rationally controlled approach for stretching/aligning DNA molecules of various lengths. Through enzymatic cleavage of λ-phage DNA to yield a series of DNA chains of various lengths from 17.3 μm down to 4.2 μm, we have investigated the flow/extension behavior of these tethered DNA molecules under different flow strengths in the flow-gradient plane. We compared Brownian dynamic simulations for the flow dynamics of tethered λ-DNA in shear, and found our flow-gradient plane experimental results matched well with our bead-spring simulations. The shear flow processing demonstrated in our studies represents a controllable approach for tethering and stretching DNA molecules of various lengths. Together with further metallization of DNA chains within DOD structures, this bottom-up approach can potentially enable efficient and reliable fabrication of large-scale nanoelectronic devices based on single organic molecules, therefore opening opportunities in both fundamental understanding of charge transport at the single molecular level and many exciting applications for ever-shrinking molecular circuits.

Capsule development and utilization for material irradiation tests

Energy Technology Data Exchange (ETDEWEB)

Kang, Young Hwan; Kim, B. G.; Joo, K. N. [and others

2000-05-01

The development program of advanced nuclear structural and fuel materials includes the in-pile tests using the instrumented capsule at HANARO. The tests were performed in the in-core test holes of CT, IR 1 and 2 and OR 4 and 5 of HANARO. Extensive efforts have also been made to establish design and manufacturing technology for the instrumented capsule and its related system, which should be compatible with the HANARO's characteristics. Since the first instrumented capsule(97M-01K) had been designed and successfully fabricated, five tests were done to support the users and provided the economic benefits to user by generating the essential in-pile information on the performance and structural integrity of materials. This paper describes the present status and future plans of these R and D activities for the development of the instrumented capsule including in-situ material property measurement capsules and nuclear fuel test capsules.

Calculating Payload for a Tethered Balloon System

Science.gov (United States)

Charles D. Tangren

1980-01-01

A graph method to calculate payload for a tethered balloon system, with the supporting helium lift and payload equations. is described. The balloon system is designed to collect emissions data during the convective-lift and no-convective-lift phases of a forest fire. A description of the balloon system and a list of factors affecting balloon selection are included....

Endoscopic medial maxillectomy breaking new frontiers.

Science.gov (United States)

Mohanty, Sanjeev; Gopinath, M

2013-07-01

Endoscopy has changed the perspective of rhinologist towards the nose. It has revolutionised the surgical management of sinonasal disorders. Sinus surgeries were the first to get the benefit of endoscope. Gradually the domain of endoscopic surgery extended to the management of sino nasal tumours. Traditionally medial maxillectomy was performed through lateral rhinotomy or mid facial degloving approach. Endoscopic medial maxillectomy has been advocated by a number of authors in the management of benign sino-nasal tumours. We present our experience of endoscopic medial maxillectomy in the management of sinonasal pathologies.

Detection of active bleeding from gastric antral vascular ectasia by capsule endoscopy

Science.gov (United States)

Ohira, Tetsuya; Hokama, Akira; Kinjo, Nagisa; Nakamoto, Manabu; Kobashigawa, Chiharu; Kise, Yuya; Yamashiro, Satoshi; Kinjo, Fukunori; Kuniyoshi, Yukio; Fujita, Jiro

2013-01-01

Gastric antral vascular ectasia (GAVE) has been recognized as one of the important causes of occult and obscure gastrointestinal bleeding. The diagnosis is typically made based on the characteristic endoscopic features, including longitudinal row of flat, reddish stripes radiating from the pylorus into the antrum that resemble the stripes on a watermelon. These appearances, however, can easily be misinterpreted as moderate to severe gastritis. Although it is believed that capsule endoscopy (CE) is not helpful for the study of the stomach with its large lumen, GAVE can be more likely to be detected at CE rather than conventional endoscopy. CE can be regarded as “physiologic” endoscopy, without the need for gastric inflation and subsequent compression of the vasculature. The blood flow of the ecstatic vessels may be diminished in an inflated stomach. Therefore, GAVE may be prominent in CE. We herein describe a case of active bleeding from GAVE detected by CE and would like to emphasize a possibility that CE can improve diagnostic yields for GAVE. PMID:23515703

Motion of an elastic capsule in a square microfluidic channel.

Science.gov (United States)

Kuriakose, S; Dimitrakopoulos, P

2011-07-01

In the present study we investigate computationally the steady-state motion of an elastic capsule along the centerline of a square microfluidic channel and compare it with that in a cylindrical tube. In particular, we consider a slightly over-inflated elastic capsule made of a strain-hardening membrane with comparable shearing and area-dilatation resistance. Under the conditions studied in this paper (i.e., small, moderate, and large capsules at low and moderate flow rates), the capsule motion in a square channel is similar to and thus governed by the same scaling laws with the capsule motion in a cylindrical tube, even though in the channel the cross section in the upstream portion of large capsules is nonaxisymmetric (i.e., square-like with rounded corners). When the hydrodynamic forces on the membrane increase, the capsule develops a pointed downstream edge and a flattened rear (possibly with a negative curvature) so that the restoring tension forces are increased as also happens with droplets. Membrane tensions increase significantly with the capsule size while the area near the downstream tip is the most probable to rupture when a capsule flows in a microchannel. Because the membrane tensions increase with the interfacial deformation, a suitable Landau-Levich-Derjaguin-Bretherton analysis reveals that the lubrication film thickness h for large capsules depends on both the capillary number Ca and the capsule size a; our computations determine the latter dependence to be (in dimensionless form) h ~ a(-2) for the large capsules studied in this work. For small and moderate capsule sizes a, the capsule velocity Ux and additional pressure drop ΔP+ are governed by the same scaling laws as for high-viscosity droplets. The velocity and additional pressure drop of large thick capsules also follow the dynamics of high-viscosity droplets, and are affected by the lubrication film thickness. The motion of our large thick capsules is characterized by a Ux-U ~ h ~ a(-2

Endoscopic management of bleeding peptic ulcers

International Nuclear Information System (INIS)

Farooqi, J.I.; Farooqi, R.J.

2001-01-01

Peptic ulcers account for more than half of the cases of non variceal upper gastrointestinal (GI) bleeding and therefore, are the focus of most of the methods of endoscopic hemostasis. Surgical intervention is now largely reserved for patients in whom endoscopic hemostasis has failed. A variety of endoscopic techniques have been employed to stop bleeding and reduce the risk of rebleeding, with no major differences in outcome between these methods. These include injection therapy, fibrin injection, heater probe, mono polar electrocautery, bipolar electrocautery, lasers and mechanical hemo clipping. The most important factor in determining outcome after gastrointestinal bleeding is rebleeding or persistent bleeding. The endoscopic appearance of an ulcer, however, provides the most useful prognostic information for bleeding. Recurrent bleeding after initial endoscopic hemostasis occurs in 15-20% of patients with a bleeding peptic ulcer. The best approach to these patients remains controversial; the current options are repeat endoscopic therapy with the same or a different technique, emergency surgery or semi elective surgery after repeat endoscopic hemostasis. The combination of epinephrine injection with thermal coagulation may be more effective than epinephrine injection alone. Newer modalities such as fibrin injection or the application of hemo clips appear promising and comparative studies are awaited. (author)

Towing Asteroids with Gravity Tractors Enhanced by Tethers and Solar Sails

Science.gov (United States)

Shen, Haijun; Roithmayr, Carlos M.

2015-01-01

Material collected from an asteroid's surface can be used to increase gravitational attraction between the asteroid and a Gravity Tractor (GT); the spacecraft therefore operates more effectively and is referred to as an Enhanced Gravity Tractor (EGT). The use of tethers and solar sails to further improve effectiveness and simplify operations is investigated. By employing a tether, the asteroidal material can be placed close to the asteroid while the spacecraft is stationed farther away, resulting in a better safety margin and improved thruster efficiency. A solar sail on a spacecraft can naturally provide radial offset and inter-spacecraft separation required for multiple EGTs.

Per-oral endoscopic myotomy: Major advance in achalasia treatment and in endoscopic surgery

Science.gov (United States)

Friedel, David; Modayil, Rani; Stavropoulos, Stavros N

2014-01-01

Per-oral endoscopic myotomy (POEM) represents a natural orifice endoscopic surgery (NOTES) approach to laparoscopy Heller myotomy (LHM). POEM is arguably the most successful clinical application of NOTES. The growth of POEM from a single center in 2008 to approximately 60 centers worldwide in 2014 with several thousand procedures having been performed attests to the success of POEM. Initial efficacy, safety and acid reflux data suggest at least equivalence of POEM to LHM, the previous gold standard for achalasia therapy. Adjunctive techniques used in the West include impedance planimetry for real-time intraprocedural luminal assessment and endoscopic suturing for challenging mucosal defect closures during POEM. The impact of POEM extends beyond the realm of esophageal motility disorders as it is rapidly popularizing endoscopic submucosal dissection in the West and spawning offshoots that use the submucosal tunnel technique for a host of new indications ranging from resection of tumors to pyloromyotomy for gastroparesis. PMID:25548473

Stability control of a flexible maneuverable tethered space net robot

Science.gov (United States)

Zhang, Fan; Huang, Panfeng

2018-04-01

As a promising solution for active space debris capture and removal, a maneuverable Tethered Space Net Robot (TSNR) is proposed as an improved Space Tethered Net (TSN). In addition to the advantages inherit to the TSN, the TSNR's maneuverability expands the capture's potential. However, oscillations caused by the TSNR's flexibility and elasticity of make higher requests of the control scheme. Based on the dynamics model, a modified adaptive super-twisting sliding mode control scheme is proposed in this paper for TSNR stability control. The proposed continuous control force can effectively suppress oscillations. Theoretical verification and numerical simulations demonstrate that the desired trajectory can be tracked steadily and efficiently by employing the proposed control scheme.

Endoscopic tissue diagnosis of cholangiocarcinoma.

LENUS (Irish Health Repository)

Harewood, Gavin C

2008-09-01

The extremely poor outcome in patients with cholangiocarcinoma, in large part, reflects the late presentation of these tumors and the challenging nature of establishing a tissue diagnosis. Establishing a diagnosis of cholangiocarcinoma requires obtaining evidence of malignancy from sampling of the epithelium of the biliary tract, which has proven to be challenging. Although endoscopic ultrasound-guided fine needle aspiration performs slightly better than endoscopic retrograde cholangiopancreatography in diagnosing cholangiocarcinoma, both endoscopic approaches demonstrate disappointing performance characteristics.

Development of remote welding techniques for in-pile IASCC capsules and evaluation of material integrity on capsules for long irradiation period

Science.gov (United States)

Shibata, A.; Nakano, J.; Ohmi, M.; Kawamata, K.; Nakagawa, T.; Tsukada, T.

2012-03-01

To simulate irradiation assisted stress corrosion cracking (IASCC) behavior by in-pile experiments, it is necessary to irradiate specimens up to a neutron fluence that is higher than the IASCC threshold fluence. Pre-irradiated specimens must be relocated from pre-irradiation capsules to in-pile capsules. Hence, a remote welding machine has been developed. And the integrity of capsule housing for a long term irradiation was evaluated by tensile tests in air and slow strain rate tests in water. Two type specimens were prepared. Specimens were obtained from the outer tubes of capsule irradiated to 1.0-3.9 × 1026 n/m2 (E > 1 MeV). And specimens were irradiated in a leaky capsule to 0.03-1.0 × 1026 n/m2. Elongation more than 15% in tensile test at 423 K was confirmed and no IGSCC fraction was shown in SSRT at 423 K which was estimated as temperature at the outer tubes of the capsule under irradiation.

Development of remote welding techniques for in-pile IASCC capsules and evaluation of material integrity on capsules for long irradiation period

International Nuclear Information System (INIS)

Shibata, A.; Nakano, J.; Ohmi, M.; Kawamata, K.; Nakagawa, T.; Tsukada, T.

2012-01-01

To simulate irradiation assisted stress corrosion cracking (IASCC) behavior by in-pile experiments, it is necessary to irradiate specimens up to a neutron fluence that is higher than the IASCC threshold fluence. Pre-irradiated specimens must be relocated from pre-irradiation capsules to in-pile capsules. Hence, a remote welding machine has been developed. And the integrity of capsule housing for a long term irradiation was evaluated by tensile tests in air and slow strain rate tests in water. Two type specimens were prepared. Specimens were obtained from the outer tubes of capsule irradiated to 1.0–3.9 × 10 26 n/m 2 (E > 1 MeV). And specimens were irradiated in a leaky capsule to 0.03–1.0 × 10 26 n/m 2 . Elongation more than 15% in tensile test at 423 K was confirmed and no IGSCC fraction was shown in SSRT at 423 K which was estimated as temperature at the outer tubes of the capsule under irradiation.

Polar tent for reduced perturbation of NIF ignition capsules

Science.gov (United States)

Hammel, B. A.; Pickworth, L.; Stadermann, M.; Field, J.; Robey, H.; Scott, H. A.; Smalyuk, V.

2016-10-01

In simulations, a tent that contacts the capsule near the poles and departs tangential to the capsule surface greatly reduces the capsule perturbation, and the resulting mass injected into the hot-spot, compared to current capsule support methods. Target fabrication appears feasible with a layered tent (43-nm polyimide + 8-nm C) for increased stiffness. We are planning quantitative measurements of the resulting shell- ρR perturbation near peak implosion velocity (PV) using enhanced self-emission backlighting, achieved by adding 1% Ar to the capsule fill in Symcaps (4He + H). Layered DT implosions are also planned for an integrated test of capsule performance. We will describe the design and simulation predictions. Prepared by LLNL under Contract DE-AC52-07NA27344.

Current Status of Peroral Endoscopic Myotomy

Science.gov (United States)

Cho, Young Kwan; Kim, Seong Hwan

2018-01-01

Peroral endoscopic myotomy (POEM) has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders. PMID:29397656

Current Status of Peroral Endoscopic Myotomy.

Science.gov (United States)

Cho, Young Kwan; Kim, Seong Hwan

2018-01-01

Peroral endoscopic myotomy (POEM) has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders.

Current Status of Peroral Endoscopic Myotomy

Directory of Open Access Journals (Sweden)

Young Kwan Cho

2018-01-01

Full Text Available Peroral endoscopic myotomy (POEM has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders.

Diagnostic and therapeutic capsules and method of producing

International Nuclear Information System (INIS)

Morcos, N.A.; Haney, T.A.; Wedeking, P.W.

1981-01-01

An article of manufacture comprising a pharmaceutical radioactive capsule formed essentially of a non-toxic, water soluble material adapted to being ingested and rapidly disintegrating on contract with fluids of the gastro-intestinal tract, and having a filler material supporting a pharmaceutically useful radioactive compound absorbable from the gastro-intestinal tract said filler material being supported by said capsule. And a method of filling a pharmaceutical radioactive capsule comprising providing filler material supporting a pharmaceutically useful radioactive compound and transporting said filler material carrying a pharmaceutically useful radioactive compound into the chamber of said capsule

Evidence for an intact polysaccharide capsule in Bordetella pertussis.

Science.gov (United States)

Neo, YiLin; Li, Rui; Howe, Josephine; Hoo, Regina; Pant, Aakanksha; Ho, SiYing; Alonso, Sylvie

2010-03-01

Polysaccharide capsules contribute to the pathogenesis of many bacteria species by providing resistance against various defense mechanisms. The production of a capsule in Bordetella pertussis, the etiologic agent of whooping cough, has remained controversial; earlier studies reported this pathogen as a capsulated microorganism whereas the recent B. pertussis genome analysis revealed the presence of a truncated capsule locus. In this work, using transmission electron microscopy and immunostaining approaches, we provide a formal evidence for the presence of an intact microcapsule produced at the surface of both laboratory strain and clinical isolates of B. pertussis. In agreement with previous studies, we found that the capsule is optimally produced in avirulent phase. Unexpectedly, the presence of the capsule was also detected at the surface of virulent B. pertussis bacteria. Consistently, a substantial transcriptional activity of the capsule operon was detected in virulent phase, suggesting that the capsular polysaccharide may play a role during pertussis pathogenesis. In vitro assays indicated that the presence of the capsule does not affect B. pertussis adherence to mammalian cells and does not further protect the bacterium from phagocytosis, complement-mediated killing or antimicrobial peptide attack. Copyright 2009. Published by Elsevier SAS.

Endurance test for DUPIC capsule

International Nuclear Information System (INIS)

Chung, Heung June; Bae, K. K.; Lee, C. Y.; Park, J. M.; Ryu, J. S.

1999-07-01

This report presents the pressure drop, vibration and endurance test results for mini-plate fuel rig which were designed fabricately by KAERI. From the pressure drop test results, it is noted that the flow rate across the capsule corresponding to the pressure drop of 200 kPa is measured to be about 9.632 kg/sec. Vibration frequency for the capsule ranges from 14 to 18.5 Hz. RMS (Root Mean Square) displacement for the fuel rig is less than 14 μm, and the maximum displacement is less than 54 μm. Based on the endurance test results, the appreciable fretting wear for the DUPIC capsule was not detected. Oxidation on the support tube is observed, also tiny trace of wear between contact points observed. (author). 4 refs., 10 tabs., 45 figs

Tethered spinal cord: the effect of neurosurgery on the lower urinary tract and male sexual function

NARCIS (Netherlands)

Boemers, T. M.; van Gool, J. D.; de Jong, T. P.

1995-01-01

To determine the effect of neurosurgical untethering on the lower urinary tract and male sexual function, in patients with tethered spinal cord. Thirty-six children with tethered spinal cord due to neurospinal dysraphism were assessed clinically and urodynamically before and after surgical

A simple method for preparing radioactive capsules in colon transit study

International Nuclear Information System (INIS)

Wang Shyhjen; Lin Wanyu; Tsai Shihchuan; Chen Granhun

2000-01-01

Colon transit study is currently performed by delivering technetium-99m or indium-111 labelled activated charcoal to the colon in a methacrylate-coated capsule (coated capsule). However, the coating procedure is complicated and methacrylate has not been approved by the Food and Drug Administration. Therefore, a simpler method is needed for the clinical routine use of colon transit study. In this study, we used a commercial empty enteric capsule and a coated capsule for the measurement of colon transit time. We compared the in vitro stability and in vivo scintigraphy of 99m Tc-labelled activated charcoal in the coated capsule and the enteric capsule to evaluate the possibility of clinical usage of the enteric capsule for colon transit time study. Activated charcoal powder was mixed with 99m Tc-diethylene triamine penta-acetic acid (DTPA) and vaporized to dryness. The dry 99m Tc-DTPA activated charcoal was loaded into the coated capsule and the enteric capsule. In vitro stability study was performed by immersing these capsules in a colourless buffer of variable pH which mimicked the conditions in the stomach and the small bowel. Capsule disruption was determined. Colon transit scintigraphy with 99m Tc-DTPA charcoal was performed in five normal volunteers using these two capsules. The in vitro stability of these two types of capsule was similar and the colon transit scintigraphy findings were almost identical. Most capsules dissolved in the ascending colon and very few in the terminal ileum. It is concluded that enteric capsule is a suitable alternative to coated capsule for measurement of colon transit. (orig.)

Failure of the capsule for coated particles irradiation

International Nuclear Information System (INIS)

Yamaki, Jikei; Nomura, Yasushi; Nagamatsuya, Takaaki; Yamahara, Takeshi; Sakai, Haruyuki

1975-10-01

During operation cycle No. 27 of the JMTR (Japan Material Testing Reactor) on May 20, 1974, leakage of the fission product gas occurred from the capsule 72F-7A, which contained coated particles for the irradiation; the coated particles are for the development of a multi-purpose high temperature gas cooled reactor. The capsule was designed for heat 1600 0 C. Three nickel plates as the heat reflector were sandwiched in between the plates of titanium and zirconium, which were adsorbents for the impurity gases in the cladding tube (Nb-1%Zr). Temperatures of the plates were about 1000 0 C under the irradiation, so one metal diffused into the other metal through interfaces, resulting in the formation of an alloy. Its melting point was lower than those of metals in the capsule. The cladding material Nb-1%Zr was melted by the alloy and finally a pin hole developed through the cladding. The process of failure, design of the capsule, post-irradiation test of the capsule and the failure-reproducing experiment with a mock-up capsule are described. (auth.)

Ling classification describes endoscopic progressive process of achalasia and successful peroral endoscopy myotomy prevents endoscopic progression of achalasia.

Science.gov (United States)

Zhang, Wen-Gang; Linghu, En-Qiang; Chai, Ning-Li; Li, Hui-Kai

2017-05-14

To verify the hypothesis that the Ling classification describes the endoscopic progressive process of achalasia and determine the ability of successful peroral endoscopic myotomy (POEM) to prevent endoscopic progression of achalasia. We retrospectively reviewed the endoscopic findings, symptom duration, and manometric data in patients with achalasia. A total of 359 patients (197 women, 162 men) with a mean age of 42.1 years (range, 12-75 years) were evaluated. Symptom duration ranged from 2 to 360 mo, with a median of 36 mo. Patients were classified with Ling type I ( n = 119), IIa ( n = 106), IIb ( n = 60), IIc ( n = 60), or III ( n = 14), according to the Ling classification. Of the 359 patients, 349 underwent POEM, among whom 21 had an endoscopic follow-up for more than 2 years. Pre-treatment and post-treatment Ling classifications of these 21 patients were compared. Symptom duration increased significantly with increasing Ling classification (from I to III) ( P achalasia and may be able to serve as an endoscopic assessment criterion for achalasia. Successful POEM (Eckardt score ≤ 3) seems to have the ability to prevent endoscopic evolvement of achalasia. However, studies with larger populations are warranted to confirm our findings.

21 CFR 884.4100 - Endoscopic electrocautery and accessories.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Endoscopic electrocautery and accessories. 884... Surgical Devices § 884.4100 Endoscopic electrocautery and accessories. (a) Identification. An endoscopic electrocautery is a device used to perform female sterilization under endoscopic observation. It is designed to...

Operator's Manual for SHEBA Powered Tether Balloon System

Science.gov (United States)

Lappen, Cara-Lyn; Randall, David A.

1998-01-01

The Surface Heat and Energy Budget of the Arctic (SHEBA) was an intensive field project which took place in the Arctic Ocean from October 1997 through October 1998. Its purpose was to measure as many facets of the Arctic environment as possible so that we would be able to better understand the interaction between the ice, atmosphere, and ocean and their interactions with global climate. One aspect of the atmospheric field component was launching tethered balloons to monitor the profiles of temperature, wind, pressure, and humidity, as well as examine the vertical structure of cloud droplet sizes and distributions. The tethered balloon that we used was one specially designed for use in freezing climates by SPEC Corporation in Boulder, Colorado. A special winch that was able to withstand Arctic temperature and weather became necessary when the testing of simple winch systems used in warmer climates failed under these extreme conditions. The purpose of this manual is to acquaint any new user to the powered tethered balloon system deployed at the The Surface Heat and Energy Budget of the Arctic (SHEBA ice camp. It includes a description of the preparations necessary to get ready for a launch, the mechanics of the actual launch, and an account of the proper procedure for taking down the equipment when finished. It will also include tips on how to minimize potential equipment failures, some trouble shooting, and some safety ideas. This manual is designed so that new operators can use the system with minimal previous training. At the end of this manual, the reader will find a quick checklist.

Liquid-core nanocellulose-shell capsules with tunable oxygen permeability.

Science.gov (United States)

Svagan, A J; Bender Koch, C; Hedenqvist, M S; Nilsson, F; Glasser, G; Baluschev, S; Andersen, M L

2016-01-20

Encapsulation of oxygen sensitive components is important in several areas, including those in the food and pharmaceutical sectors, in order to improve shelf-life (oxidation resistance). Neat nanocellulose films demonstrate outstanding oxygen barrier properties, and thus nanocellulose-based capsules are interesting from the perspective of enhanced protection from oxygen. Herein, two types of nanocellulose-based capsules with liquid hexadecane cores were successfully prepared; a primary nanocellulose polyurea-urethane capsule (diameter: 1.66 μm) and a bigger aggregate capsule (diameter: 8.3 μm) containing several primary capsules in a nanocellulose matrix. To quantify oxygen permeation through the capsule walls, an oxygen-sensitive spin probe was dissolved within the liquid hexadecane core, allowing non-invasive measurements (spin-probe oximetry, electron spin resonance, ESR) of the oxygen concentration within the core. It was observed that the oxygen uptake rate was significantly reduced for both capsule types compared to a neat hexadecane solution containing the spin-probe, i.e. the slope of the non-steady state part of the ESR-curve was approximately one-third and one-ninth for the primary nanocellulose capsule and aggregated capsule, respectively, compared to that for the hexadecane sample. The transport of oxygen was modeled mathematically and by fitting to the experimental data, the oxygen diffusion coefficients of the capsule wall was determined. These values were, however, lower than expected and one plausible reason for this was that the ESR-technique underestimate the true oxygen uptake rate in the present systems at non-steady conditions, when the overall diffusion of oxygen was very slow. Copyright © 2015 Elsevier Ltd. All rights reserved.

Deformation of ovalbumin-alginate capsules in a T-Junction

Science.gov (United States)

Häner, Edgar; Juel, Anne

2015-11-01

We study experimentally the flow-induced deformation of liquid-filled ovalbumin-alginate capsules in a T-junction. In applications, capsules/cells often negotiate branched networks with junctions thus experiencing large deformations. We investigate the constant volume-flux viscous flow of buoyancy-neutral thin-walled capsules close to the centreline of rectangular channels, by comparison to near-rigid gelled beads. The motion of the capsules in straight channels scales with the capillary number - the ration of viscous to elastic forces. However, the effect of elastic deformation on the motion is sufficiently weak that a rigid sphere model predicts the velocity of capsules with diameters of up to 70% of that of the channel to within 5%. In the T-junction, systematic selection of daughter channel (right-left) occurs outside a finite region around the channel centreline, by contrast with near-rigid gelled beads, where the actual centreline is the separator. We quantify the behaviour of capsules in terms of their longitudinal stretching (up to a factor of three without rupture). We show the large range of deformations encountered can be applied to the measurement of the elastic properties of capsules as well as to the geometric-induced sorting and manipulation of capsules.

Development of a Low Temperature Irradiation Capsule for Research Reactor Materials

International Nuclear Information System (INIS)

Choo, Kee Nam; Cho, Man Soon; Lee, Cheol Yong; Yang, Sung Woo; Shin, Yoon Taek; Park, Seng Jae; Kang, Suk Hoon; Kang, Young Hwan; Park, Sang Jun

2013-01-01

A new capsule design was prepared and tested at HANARO for a neutron irradiation of core materials of research reactors as a part of the research reactor development project. Irradiation testing of the materials including graphite, beryllium, and zircaloy-4 that are supposed to be used as core materials in research reactors was required for irradiation at up to 8 reactor operation cycles at low temperature (<100 .deg. C). Therefore, three instrumented capsules were designed and fabricated for an evaluation of the neutron irradiation properties of the core materials (Graphite, Be, Zircaloy-4) of research reactors. The capsules were first designed and fabricated to irradiate materials at low temperature (<100 .deg. C) for a long cycle of 8 irradiation cycles at HANARO. Therefore, the safety of the new designed capsule should be fully checked before irradiation testing. Out-pile performance and endurance testing before HANARO irradiation testing was performed using a capsule under a 110% condition of a reactor coolant flow amount. The structural integrity of the capsule was analyzed in terms of a vibration-induced fatigue cracking of a rod tip of the capsule that is suspected to be the most vulnerable part of a capsule. Another two capsules were irradiated at HANARO for 4 cycles, and one capsule was transferred to a hot cell to examine the integrity of the rod tip of the capsule. After confirming the soundness of the 4 cycle-irradiated capsule, the remaining capsule was irradiated at up to 8 cycles at HANARO. Based on the structural integrity analysis of the capsule, an improved capsule design will be suggested for a longer irradiation test at HANARO

Three-dimensional simulations of Nova capsule implosion experiments

International Nuclear Information System (INIS)

Marinak, M.M.; Tipton, R.E.; Landen, O.L.

1995-01-01

Capsule implosion experiments carried out on the Nova laser are simulated with the three-dimensional HYDRA radiation hydrodynamics code. Simulations of ordered near single mode perturbations indicate that structures which evolve into round spikes can penetrate farthest into the hot spot. Bubble-shaped perturbations can burn through the capsule shell fastest, however, causing even more damage. Simulations of a capsule with multimode perturbations shows spike amplitudes evolving in good agreement with a saturation model during the deceleration phase. The presence of sizable low mode asymmetry, caused either by drive asymmetry or perturbations in the capsule shell, can dramatically affect the manner in which spikes approach the center of the hot spot. Three-dimensional coupling between the low mode shell perturbations intrinsic to Nova capsules and the drive asymmetry brings the simulated yields into closer agreement with the experimental values

Electromechanical engineering in SnO2 nanoparticle tethered hybrid ionic liquid

Science.gov (United States)

Deb, Debalina; Bhattacharya, Subhratanu

2017-05-01

Challenge of developing electrolytes comprising synergic properties of high mechanical strength with superior electrical and electrochemical properties has so far been unmet towards the application of secondary storage devices. In this research, we have engineered the electromechanical properties of 2-(trimethylamino) ethyl methacrylate bis(trifluoromethylsulfonyl) imide [TMEM]TFSI ionic liquid by tethering silane modified SnO2 nanoparticles within it. Different percentages of tethering are employed to achieve improved ionic conductivity, better discharge/ charging ratio (40%) along with gel like mechanical properties. Our findings appear to provide an optimal solution towards the future prospects in application in a number of areas, notably in energy-related technologies.

Equilibrium ignition for ICF capsules

International Nuclear Information System (INIS)

Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

1993-01-01

There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative

Endoscopic management of hilar biliary strictures

Science.gov (United States)

Singh, Rajiv Ranjan; Singh, Virendra

2015-01-01

Hilar biliary strictures are caused by various benign and malignant conditions. It is difficult to differentiate benign and malignant strictures. Postcholecystectomy benign biliary strictures are frequently encountered. Endoscopic management of these strictures is challenging. An endoscopic method has been advocated that involves placement of increasing number of stents at regular intervals to resolve the stricture. Malignant hilar strictures are mostly unresectable at the time of diagnosis and only palliation is possible.Endoscopic palliation is preferred over surgery or radiological intervention. Magnetic resonance cholangiopancreaticography is quite important in the management of these strictures. Metal stents are superior to plastic stents. The opinion is divided over the issue of unilateral or bilateral stenting.Minimal contrast or no contrast technique has been advocated during endoscopic retrograde cholangiopancreatography of these patients. The role of intraluminal brachytherapy, intraductal ablation devices, photodynamic therapy, and endoscopic ultrasound still remains to be defined. PMID:26191345

Endoscopes with latest technology and concept.

Science.gov (United States)

Gotoh

2003-09-01

Endoscopic imaging systems that perform as the "eye" of the operator during endoscopic surgical procedures have developed rapidly due to various technological developments. In addition, since the most recent turn of the century robotic surgery has increased its scope through the utilization of systems such as Intuitive Surgical's da Vinci System. To optimize the imaging required for precise robotic surgery, a unique endoscope has been developed, consisting of both a two dimensional (2D) image optical system for wider observation of the entire surgical field, and a three dimensional (3D) image optical system for observation of the more precise details at the operative site. Additionally, a "near infrared radiation" endoscopic system is under development to detect the sentinel lymph node more readily. Such progress in the area of endoscopic imaging is expected to enhance the surgical procedure from both the patient's and the surgeon's point of view.

Positron radiography of ignition-relevant ICF capsules

Science.gov (United States)

Williams, G. J.; Chen, Hui; Field, J. E.; Landen, O. L.; Strozzi, D. J.

2017-12-01

Laser-generated positrons are evaluated as a probe source to radiograph in-flight ignition-relevant inertial confinement fusion capsules. Current ultraintense laser facilities are capable of producing 2 × 1012 relativistic positrons in a narrow energy bandwidth and short time duration. Monte Carlo simulations suggest that the unique characteristics of such positrons allow for the reconstruction of both capsule shell radius and areal density between 0.002 and 2 g/cm2. The energy-downshifted positron spectrum and angular scattering of the source particles are sufficient to constrain the conditions of the capsule between preshot and stagnation. We evaluate the effects of magnetic fields near the capsule surface using analytic estimates where it is shown that this diagnostic can tolerate line integrated field strengths of 100 T mm.

Endoscopic transmission of Helicobacter pylori

NARCIS (Netherlands)

Tytgat, G. N.

1995-01-01

The contamination of endoscopes and biopsy forceps with Helicobacter pylori occurs readily after endoscopic examination of H. pylori-positive patients. Unequivocal proof of iatrogenic transmission of the organism has been provided. Estimates for transmission frequency approximate to 4 per 1000

Stationary Tether Device for Buoy Apparatus and System for Using

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A rigid, neutrally buoyant hydrodynamicaly-faired tether and associated fastening hardware that loosely holds a bathymetric float at a predetermined distance from a...

Fiber Optic Shape Sensing for Tethered Marsupial Rovers, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Building upon the successful proof of concept work in Phase I, Luna Innovations Incorporated is proposing to design, build, and test a sensing tether for marsupial...

Gynaecological Endoscopic Surgical Education and Assessment. A diploma programme in gynaecological endoscopic surgery.

Science.gov (United States)

Campo, Rudi; Wattiez, Arnaud; Tanos, Vasilis; Di Spiezio Sardo, Attilio; Grimbizis, Grigoris; Wallwiener, Diethelm; Brucker, Sara; Puga, Marco; Molinas, Roger; O'Donovan, Peter; Deprest, Jan; Van Belle, Yves; Lissens, Ann; Herrmann, Anja; Tahir, Mahmood; Benedetto, Chiara; Siebert, Igno; Rabischong, Benoit; De Wilde, Rudy Leon

2016-04-01

In recent years, training and education in endoscopic surgery has been critically reviewed. Clinicians, both surgeons as gynaecologist who perform endoscopic surgery without proper training of the specific psychomotor skills are at higher risk to increased patient morbidity and mortality. Although the apprentice-tutor model has long been a successful approach for training of surgeons, recently, clinicians have recognised that endoscopic surgery requires an important training phase outside the operating theatre. The Gynaecological Endoscopic Surgical Education and Assessment programme (GESEA), recognises the necessity of this structured approach and implements two separated stages in its learning strategy. In the first stage, a skill certificate on theoretical knowledge and specific practical psychomotor skills is acquired through a high stake exam; in the second stage, a clinical programme is completed to achieve surgical competence and receive the corresponding diploma. Three diplomas can be awarded: (a) the Bachelor in Endoscopy; (b) the Minimally Invasive Gynaecological Surgeon (MIGS); and (c) the Master level. The Master level is sub-divided into two separate diplomas: the Master in Laparoscopic Pelvic Surgery and the Master in Hysteroscopy. The complexity of modern surgery has increased the demands and challenges to surgical education and the quality control. This programme is based on the best available scientific evidence and it counteracts the problem of the traditional surgical apprentice tutor model. It is seen as a major step toward standardization of endoscopic surgical training in general. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Production of 131I gelatin capsules

International Nuclear Information System (INIS)

Freud, A.; Hirshfeld, N.; Canfi, A.; Melamud, Y.

1997-01-01

Radioiodine ( 131 I) hard-gelatin capsules are widely used for the diagnosis and treatment of various thyroid disorders. Until 1980 radioiodine was supplied by us as a liquid dosage. This proved to be a rather inconvenient form since it resulted in inaccurate dosing by the physicians and caused frequent contamination of the patients and the hospital personnel. In an attempt to overcome these problems we have designed and constructed a production facility for capsules in which 1311 is packaged. Because of the extreme precautions necessary in handling radioactive compounds, encapsulation of radioactive materials requires specifically designed production techniques, special instrumentation and unique quality control procedures that are not encountered in the standard capsule production processes in the pharmaceutical industry

Pneumatic capsule with a measuring system for in-pile irradiation

International Nuclear Information System (INIS)

Oshima, Keiichi; Yamazaki, Yasaburo; Hirata, Mitsuho; Ishii, Toshio; Shimozawa, Ryohei.

1967-01-01

A prior-art in-pile irradiation apparatus wherein a rabbit containing an irradiation specimen therein is inserted into and removed from a pile by a pneumatic system does not include means for measuring the temperature and pressure of the specimen under irradiation. When the rabbit is deformed during irradiation, it cannot be reliably recovered. A pneumatic capsule assembly with a measuring system according to this invention has a double structure which consists of an inner capsule containing the specimen therein and an outer capsule evacuated or filled with a gas. A thermocouple lace wire and a strain gauge are welded on the outside surface of the inner capsule as detection terminals for measuring the temperature and pressure. A rupture plate which bursts when the pressure in the inner capsule reaches a predetermined value is provided at a part of the inner capsule, and a fin for heat transmission is provided between the inner and outer capsules to thus prevent the deformation of the pneumatic capsule assembly as a whole. (Takasuka, S.)

75 FR 47316 - Centennial Challenges 2010 Strong Tether Challenge

Science.gov (United States)

2010-08-05

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Centennial Challenges 2010 Strong Tether Challenge... teams that wish to compete may register. Centennial Challenges is a program of prize competitions to..., please visit: http://www.spaceward.org/elevator2010-ts . For general information on the NASA Centennial...

No stabilizing effect of the elbow joint capsule. A kinematic study

DEFF Research Database (Denmark)

Nielsen, K K; Olsen, Bo Sanderhoff

1999-01-01

We dissected 7 cadaveric elbow specimens, leaving the collateral ligaments and the joint capsule intact. The anterior and the posterior capsule were sequentially transected, followed by kinematic testings. We found no change in joint laxity after total transection of the capsule.......We dissected 7 cadaveric elbow specimens, leaving the collateral ligaments and the joint capsule intact. The anterior and the posterior capsule were sequentially transected, followed by kinematic testings. We found no change in joint laxity after total transection of the capsule....

Endoscopic Medial Maxillectomy Breaking New Frontiers

OpenAIRE

Mohanty, Sanjeev; Gopinath, M.

2011-01-01

Endoscopy has changed the perspective of rhinologist towards the nose. It has revolutionised the surgical management of sinonasal disorders. Sinus surgeries were the first to get the benefit of endoscope. Gradually the domain of endoscopic surgery extended to the management of sino nasal tumours. Traditionally medial maxillectomy was performed through lateral rhinotomy or mid facial degloving approach. Endoscopic medial maxillectomy has been advocated by a number of authors in the management ...

Endoscopic management of intraoperative small bowel laceration during natural orifice translumenal endoscopic surgery: a blinded porcine study.

Science.gov (United States)

Fyock, Christopher J; Forsmark, Chris E; Wagh, Mihir S

2011-01-01

Natural orifice translumenal endoscopic surgery (NOTES) has recently gained great enthusiasm, but there is concern regarding the ability to endoscopically manage complications purely via natural orifices. To assess the feasibility of endoscopically managing enteral perforation during NOTES using currently available endoscopic accessories. Twelve pigs underwent transgastric or transcolonic endoscopic exploration. Full-thickness enterotomies were intentionally created to mimic accidental small bowel lacerations during NOTES. These lacerations were then closed with endoclips. In the blinded arm of the study, small bowel repair was performed by a second blinded endoscopist. Adequate closure of the laceration was confirmed with a leak test. Primary access sites were closed with endoclips or T-anchors. At necropsy, the peritoneal cavity was inspected for abscesses, bleeding, or damage to surrounding structures. The enterotomy site was examined for adequacy of closure, adhesions, or evidence of infection. Fifteen small bowel lacerations were performed in 12 animals. Successful closure was achieved in all 10 cases in the nonblinded arm. Survival animals had an uncomplicated postoperative course and all enterotomy sites were well healed without evidence of necrosis, adhesions, abscess, or bleeding at necropsy. Leak test was negative in all animals. In the blinded arm, both small intestinal lacerations could not be identified by the blinded endoscopist. Necropsy revealed open small bowel lacerations. Small intestinal injuries are difficult to localize with currently available flexible endoscopes and accessories. Endoscopic clips, however, may be adequate for closure of small bowel lacerations if the site of injury is known.

Radioactive gas-containing polymeric capsule

International Nuclear Information System (INIS)

Winchell, H.S.; Lewis, R.E.

1975-01-01

A disposable ventilation study system for dispensing a single patient dosage of gaseous radioisotopes to patients for pulmonary function studies is disclosed. A gas impermeable capsule encloses the gaseous radioisotope and is stored within a radioactivity shielding body of valve means which shears the capsule to dispense the radioisotope to the patient. A breathing bag receives the patient's exhalation of the radioisotope and permits rebreathing of the radioisotope by the patient. 18 claims, 7 drawing figures

Clustering of tethered satellite system simulation data by an adaptive neuro-fuzzy algorithm

Science.gov (United States)

Mitra, Sunanda; Pemmaraju, Surya

1992-01-01

Recent developments in neuro-fuzzy systems indicate that the concepts of adaptive pattern recognition, when used to identify appropriate control actions corresponding to clusters of patterns representing system states in dynamic nonlinear control systems, may result in innovative designs. A modular, unsupervised neural network architecture, in which fuzzy learning rules have been embedded is used for on-line identification of similar states. The architecture and control rules involved in Adaptive Fuzzy Leader Clustering (AFLC) allow this system to be incorporated in control systems for identification of system states corresponding to specific control actions. We have used this algorithm to cluster the simulation data of Tethered Satellite System (TSS) to estimate the range of delta voltages necessary to maintain the desired length rate of the tether. The AFLC algorithm is capable of on-line estimation of the appropriate control voltages from the corresponding length error and length rate error without a priori knowledge of their membership functions and familarity with the behavior of the Tethered Satellite System.

Design procedure of capsule with multistage heater control (named MUSTAC)

International Nuclear Information System (INIS)

Someya, Hiroyuki; Endoh, Yasuichi; Hoshiya, Taiji; Niimi, Motoji; Harayama, Yasuo

1990-11-01

A capsule with electric heaters at multistage (named MUSTAC) is a type of capsule used in JMTR. The heaters are assembled in the capsule. Supply electric current to the heaters can be independently adjusted with a control systems that keeps irradiation specimens to constant temperature. The capsule being used, the irradiation specimen are inserted into specimen holders. Gas-gap size, between outer surface of specimen holders and inner surface of capsule casing, is calculated and determined to be flatten temperature of loaded specimens over the region. The rise or drop of specimen temperature in accordance with reactor power fluctuations is corrected within the target temperature of specimen by using the heaters filled into groove at specimen holder surface. The present report attempts to propose a reasonable design procedure of the capsules by means of compiling experience for designs, works and irradiation data of the capsules and to prepare for useful informations against onward capsule design. The key point of the capsule lies on thermal design. Now design thermal calculations are complicated in case of specimen holder with multihole. Resolving these issues, it is considered from new on that an emphasis have to placed on settling a thermal calculation device, for an example, a computer program on calculation specimen temperature. (author)

Tethered balloon operation for wintering aerosol measurements in the lower troposphere at Syowa Station, Antarctica

OpenAIRE

Keiichiro Hara; Kazuo Osada; Takashi Yamanouchi

2007-01-01

The 46th Japanese Antarctic Research Expedition (JARE-46) carried out twenty seven tethered-balloon-borne aerosol measurements at Syowa Station for better understanding of aerosol chemical and physical properties in the lower troposphere from 6th January 2005 until 11 December 2005. This report summarizes the plan, preparation, field activities and some troubles/problems in the tethered-balloon observations.

Tethered balloon operation for wintering aerosol measurements in the lower troposphere at Syowa Station, Antarctica

Directory of Open Access Journals (Sweden)

Keiichiro Hara

2007-03-01

Full Text Available The 46th Japanese Antarctic Research Expedition (JARE-46 carried out twenty seven tethered-balloon-borne aerosol measurements at Syowa Station for better understanding of aerosol chemical and physical properties in the lower troposphere from 6th January 2005 until 11 December 2005. This report summarizes the plan, preparation, field activities and some troubles/problems in the tethered-balloon observations.

Ingestible capsule for remote controlled release of a substance

DEFF Research Database (Denmark)

2014-01-01

The application relates to an ingestible capsule (102) for delivery of a substance e.g. a pharmaceutical drug, to a human or animal. The ingestible capsule comprises a capsule wall structure (202) forming a substantially sealed reservoir or lumen holding the substance (204). An electrical resonance...

Lifting options for stratospheric aerosol geoengineering: advantages of tethered balloon systems.

Science.gov (United States)

Davidson, Peter; Burgoyne, Chris; Hunt, Hugh; Causier, Matt

2012-09-13

The Royal Society report 'Geoengineering the Climate' identified solar radiation management using albedo-enhancing aerosols injected into the stratosphere as the most affordable and effective option for geoengineering, but did not consider in any detail the options for delivery. This paper provides outline engineering analyses of the options, both for batch-delivery processes, following up on previous work for artillery shells, missiles, aircraft and free-flying balloons, as well as a more lengthy analysis of continuous-delivery systems that require a pipe connected to the ground and supported at a height of 20 km, either by a tower or by a tethered balloon. Towers are shown not to be practical, but a tethered balloon delivery system, with high-pressure pumping, appears to have much lower operating and capital costs than all other delivery options. Instead of transporting sulphuric acid mist precursors, such a system could also be used to transport slurries of high refractive index particles such as coated titanium dioxide. The use of such particles would allow useful experiments on opacity, coagulation and atmospheric chemistry at modest rates so as not to perturb regional or global climatic conditions, thus reducing scale-up risks. Criteria for particle choice are discussed, including the need to minimize or prevent ozone destruction. The paper estimates the time scales and relatively modest costs required if a tethered balloon system were to be introduced in a measured way with testing and development work proceeding over three decades, rather than in an emergency. The manufacture of a tether capable of sustaining the high tensions and internal pressures needed, as well as strong winds, is a significant challenge, as is the development of the necessary pumping and dispersion technologies. The greatest challenge may be the manufacture and launch of very large balloons, but means have been identified to significantly reduce the size of such balloons or aerostats.

Stabilization of periodic solutions in a tethered satellite system by damping injection

DEFF Research Database (Denmark)

Larsen, Martin Birkelund; Blanke, Mogens

2009-01-01

presents a control design for stabilizing these periodic solutions. The design consists of a control law for stabilizing the open-loop equilibrium and a bias term which forces the system trajectory away from the equilibrium. The tether needs to be positioned away from open-loop equilibrium for the tether...... to affect the orbit parameters. An approximation of the periodic solutions of the closed loop system is found as a series expansion in the parameter plane spanned by the controller gain and the bias term. The stability of the solutions is investigated using linear Floquet analysis of the variational...

Crowded, Confined, and Frustrated: Dynamics of Molecules Tethered to Nanoparticles

KAUST Repository

Agarwal, Praveen; Kim, Sung A.; Archer, Lynden A.

2012-01-01

Above a critical chemistry-dependent molecular weight, all polymer molecules entangle and, as a result, exhibit slow dynamics, enhanced viscosity, and elasticity. Herein we report on the dynamics of low molecular weight polymers tethered

Disaster Coverage Predication for the Emerging Tethered Balloon Technology: Capability for Preparedness, Detection, Mitigation, and Response.

Science.gov (United States)

Alsamhi, Saeed H; Samar Ansari, Mohd; Rajput, Navin S

2018-04-01

A disaster is a consequence of natural hazards and terrorist acts, which have significant potential to disrupt the entire wireless communication infrastructure. Therefore, the essential rescue squads and recovery operations during a catastrophic event will be severely debilitated. To provide efficient communication services, and to reduce casualty mortality and morbidity during the catastrophic events, we proposed the Tethered Balloon technology for disaster preparedness, detection, mitigation, and recovery assessment. The proposed Tethered Balloon is applicable to any type of disaster except for storms. The Tethered Balloon is being actively researched and developed as a simple solution to improve the performance of rescues, facilities, and services of emergency medical communication in the disaster area. The most important requirement for rescue and relief teams during or after the disaster is a high quality of service of delivery communication services to save people's lives. Using our proposed technology, we report that the Tethered Balloon has a large disaster coverage area. Therefore, the rescue and research teams are given higher priority, and their performance significantly improved in the particular coverage area. Tethered Balloon features made it suitable for disaster preparedness, mitigation, and recovery. The performance of rescue and relief teams was effective and efficient before and after the disaster as well as can be continued to coordinate the relief teams until disaster recovery. (Disaster Med Public Health Preparedness. 2018;12:222-231).

Refining the tethering of American oysters (Crassostrea virginica) to measure the effects of two environmental stressors.

Science.gov (United States)

Poirier, Luke A; Gilbert, Shane T C; St-Hilaire, Sophie; Davidson, Jeff; Cox, Ruth; Quijón, Pedro A

2018-02-01

Tethering assays, or the physical restraint of test organisms, has been used in the past to measure selected organisms' response to stressors while removing the observer from the experimental setting. Although informative for monitoring and hypothesis testing, these assays often used microfilaments that have been found to be too invasive or prone to biases given their effects on test organisms' behavior. Here, we describe a new variation of tethering using American oysters (Crassostrea virginica) and illustrate its use in the study of their mortality rates as a result of two stressors: siltation and predation by a non-indigenous species. Our protocol identified a resistant (non-toxic) glue that could be used to attach oysters to stone slabs, thus partially mimicking the natural cementation of the shell to natural substrates. This variation of tethering was harmless and maintained oysters' body position and natural ability to filter feed. Using tethered oysters in separate two-week field cage experiments, we also show how siltation and predation by a non-indigenous species (the European green crab, Carcinus maenas), caused a gradual, easily measurable increase in oyster mortality rates. We argue that this variation of tethering is a cost-effective and advantageous way to monitor or test the effects of these and other stressors on oysters and similar species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isothermal pumping analysis for high-altitude tethered balloons.

Science.gov (United States)

Kuo, Kirsty A; Hunt, Hugh E M

2015-06-01

High-altitude tethered balloons have potential applications in communications, surveillance, meteorological observations and climate engineering. To maintain balloon buoyancy, power fuel cells and perturb atmospheric conditions, fluids could be pumped from ground level to altitude using the tether as a hose. This paper examines the pumping requirements of such a delivery system. Cases considered include delivery of hydrogen, sulfur dioxide (SO2) and powders as fluid-based slurries. Isothermal analysis is used to determine the variation of pressures and velocities along the pipe length. Results show that transport of small quantities of hydrogen to power fuel cells and maintain balloon buoyancy can be achieved at pressures and temperatures that are tolerable in terms of both the pipe strength and the current state of pumping technologies. To avoid solidification, transport of SO2 would require elevated temperatures that cannot be tolerated by the strength fibres in the pipe. While the use of particle-based slurries rather than SO2 for climate engineering can reduce the pipe size significantly, the pumping pressures are close to the maximum bursting pressure of the pipe.

Towards automated visual flexible endoscope navigation.

Science.gov (United States)

van der Stap, Nanda; van der Heijden, Ferdinand; Broeders, Ivo A M J

2013-10-01

The design of flexible endoscopes has not changed significantly in the past 50 years. A trend is observed towards a wider application of flexible endoscopes with an increasing role in complex intraluminal therapeutic procedures. The nonintuitive and nonergonomical steering mechanism now forms a barrier in the extension of flexible endoscope applications. Automating the navigation of endoscopes could be a solution for this problem. This paper summarizes the current state of the art in image-based navigation algorithms. The objectives are to find the most promising navigation system(s) to date and to indicate fields for further research. A systematic literature search was performed using three general search terms in two medical-technological literature databases. Papers were included according to the inclusion criteria. A total of 135 papers were analyzed. Ultimately, 26 were included. Navigation often is based on visual information, which means steering the endoscope using the images that the endoscope produces. Two main techniques are described: lumen centralization and visual odometry. Although the research results are promising, no successful, commercially available automated flexible endoscopy system exists to date. Automated systems that employ conventional flexible endoscopes show the most promising prospects in terms of cost and applicability. To produce such a system, the research focus should lie on finding low-cost mechatronics and technologically robust steering algorithms. Additional functionality and increased efficiency can be obtained through software development. The first priority is to find real-time, robust steering algorithms. These algorithms need to handle bubbles, motion blur, and other image artifacts without disrupting the steering process.

Spheroidal and conical shapes of ferrofluid-filled capsules in magnetic fields

Science.gov (United States)

Wischnewski, Christian; Kierfeld, Jan

2018-04-01

We investigate the deformation of soft spherical elastic capsules filled with a ferrofluid in external uniform magnetic fields at fixed volume by a combination of numerical and analytical approaches. We develop a numerical iterative solution strategy based on nonlinear elastic shape equations to calculate the stretched capsule shape numerically and a coupled finite element and boundary element method to solve the corresponding magnetostatic problem and employ analytical linear response theory, approximative energy minimization, and slender-body theory. The observed deformation behavior is qualitatively similar to the deformation of ferrofluid droplets in uniform magnetic fields. Homogeneous magnetic fields elongate the capsule and a discontinuous shape transition from a spheroidal shape to a conical shape takes place at a critical field strength. We investigate how capsule elasticity modifies this hysteretic shape transition. We show that conical capsule shapes are possible but involve diverging stretch factors at the tips, which gives rise to rupture for real capsule materials. In a slender-body approximation we find that the critical susceptibility above which conical shapes occur for ferrofluid capsules is the same as for droplets. At small fields capsules remain spheroidal and we characterize the deformation of spheroidal capsules both analytically and numerically. Finally, we determine whether wrinkling of a spheroidal capsule occurs during elongation in a magnetic field and how it modifies the stretching behavior. We find the nontrivial dependence between the extent of the wrinkled region and capsule elongation. Our results can be helpful in quantitatively determining capsule or ferrofluid material properties from magnetic deformation experiments. All results also apply to elastic capsules filled with a dielectric liquid in an external uniform electric field.

Associative visual learning by tethered bees in a controlled visual environment.

Science.gov (United States)

Buatois, Alexis; Pichot, Cécile; Schultheiss, Patrick; Sandoz, Jean-Christophe; Lazzari, Claudio R; Chittka, Lars; Avarguès-Weber, Aurore; Giurfa, Martin

2017-10-10

Free-flying honeybees exhibit remarkable cognitive capacities but the neural underpinnings of these capacities cannot be studied in flying insects. Conversely, immobilized bees are accessible to neurobiological investigation but display poor visual learning. To overcome this limitation, we aimed at establishing a controlled visual environment in which tethered bees walking on a spherical treadmill learn to discriminate visual stimuli video projected in front of them. Freely flying bees trained to walk into a miniature Y-maze displaying these stimuli in a dark environment learned the visual discrimination efficiently when one of them (CS+) was paired with sucrose and the other with quinine solution (CS-). Adapting this discrimination to the treadmill paradigm with a tethered, walking bee was successful as bees exhibited robust discrimination and preferred the CS+ to the CS- after training. As learning was better in the maze, movement freedom, active vision and behavioral context might be important for visual learning. The nature of the punishment associated with the CS- also affects learning as quinine and distilled water enhanced the proportion of learners. Thus, visual learning is amenable to a controlled environment in which tethered bees learn visual stimuli, a result that is important for future neurobiological studies in virtual reality.

Effect of endoscopic transpapillary biliary drainage with/without endoscopic sphincterotomy on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with biliary stricture (E-BEST): a protocol for a multicentre randomised controlled trial.

Science.gov (United States)

Kato, Shin; Kuwatani, Masaki; Sugiura, Ryo; Sano, Itsuki; Kawakubo, Kazumichi; Ono, Kota; Sakamoto, Naoya

2017-08-11

The effect of endoscopic sphincterotomy prior to endoscopic biliary stenting to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis remains to be fully elucidated. The aim of this study is to prospectively evaluate the non-inferiority of non-endoscopic sphincterotomy prior to stenting for naïve major duodenal papilla compared with endoscopic sphincterotomy prior to stenting in patients with biliary stricture. We designed a multicentre randomised controlled trial, for which we will recruit 370 patients with biliary stricture requiring endoscopic biliary stenting from 26 high-volume institutions in Japan. Patients will be randomly allocated to the endoscopic sphincterotomy group or the non-endoscopic sphincterotomy group. The main outcome measure is the incidence of pancreatitis within 2 days of initial transpapillary biliary drainage. Data will be analysed on completion of the study. We will calculate the 95% confidence intervals (CIs) of the incidence of pancreatitis in each group and analyse weather the difference in both groups with 95% CIs is within the non-inferiority margin (6%) using the Wald method. This study has been approved by the institutional review board of Hokkaido University Hospital (IRB: 016-0181). Results will be submitted for presentation at an international medical conference and published in a peer-reviewed journal. The University Hospital Medical Information Network ID: UMIN000025727 Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

New techniques in gastrointestinal endoscopic surgery

Directory of Open Access Journals (Sweden)

Rafael Antonio Luengas Tello

2012-09-01

Full Text Available Gastrointestinal endoscopic surgery has been making great progress since the seventies in the management paradigms of conditions such as gastrointestinal bleeding, polyp resection and diagnostic and therapeutic management of the biliary tract. The current challenge is the development of techniques that allow endoscopic treatment of emerging diseases such as cancer, morbid obesity, gastro-esophageal reflux and achalasia. This article reports on new techniques and expectations for the future in the endoscopic management of these diseases.

A Fiber-Optic Tether for the Hull Search UUV System Documentation

National Research Council Canada - National Science Library

Buescher, J. G

2006-01-01

...) conducting ship hull inspection missions, defines the required specifications that will allow the integration and installation of a FO tether system on UUVs with ship hull inspection capability...

[Natural Orifice Transluminal Endoscopic Surgery (NOTES)].

Science.gov (United States)

Kim, Yong Sik; Kim, Chul Young; Chun, Hoon Jai

2008-03-01

Recently, the field of gastrointestinal endoscopy is developing rapidly. Once limited to the gastroinstestinal lumen, the endoscopic technology is now breaking the barriers and extending its boundary to peritoneal and pleural space. In 2004, Dr. Kalloo, a gastroenterologist, observed intraperitoneal organs of a pig using a conventional endoscope through the stomach wall. Since then, new endoscopic technique of intraperitoneal intervention with transluminal approach named the Natural Orifice Transluminal Endoscopic Surgery or NOTES has been introduced. NOTES reaches the target organ by inserting the endoscope through a natural orifice (e.g. mouth, anus, vagina, urethra) and entering the peritoneal lumen by means of making an incision on the luminal wall. After a series of successful experiences in animal studies, NOTES are now being tried on human subjects. There are still many obstacles to overcome, but bright future for this new technology is expected because of its proposed advantages of less pain, lower complication rate, short recovery time, and scarless access. In this review, we plan to learn about NOTES.

A simplified tether model for molecular motor transporting cargo

International Nuclear Information System (INIS)

Fang-Zhen, Li; Li-Chun, Jiang

2010-01-01

Molecular motors are proteins or protein complexes which function as transporting engines in biological cells. This paper models the tether between motor and its cargo as a symmetric linear potential. Different from Elston and Peskin's work for which performance of the system was discussed only in some limiting cases, this study produces analytic solutions of the problem for general cases by simplifying the transport system into two physical states, which makes it possible to discuss the dynamics of the motor–cargo system in detail. It turns out that the tether strength between motor and cargo should be greater than a threshold or the motor will fail to transport the cargo, which was not discussed by former researchers yet. Value of the threshold depends on the diffusion coefficients of cargo and motor and also on the strength of the Brownian ratchets dragging the system. The threshold approaches a finite constant when the strength of the ratchet tends to infinity. (general)

Phase 3 study of selected tether applications in space. Volume 2: Study results

Science.gov (United States)

1986-01-01

Engineering designs were developed relative to a tethered launch assist from the Shuttle for payloads up to 10,000 kg mass and the tethering of a 15,000 kg science platform from the space station. These designs are used for a cost benefit analysis which assesses the feasibility of using such systems as a practical alternative to what would otherwise be accomplished by conventional means. The term conventional as related to both these applications is intended to apply to the use of some form(s) of chemical propulsion system.

[Tracheotomy-endoscop for dilatational percutaneous tracheotomy (TED)].

Science.gov (United States)

Klemm, Eckart

2006-09-01

While surgical tracheotomies are currently performed using state-of-the-art operative techniques, percutaneous dilatational tracheostomy (PDT) is in a rapidly evolving state with regard to its technology and the number of techniques available. This has resulted in a range of new complications that are difficult to quantify on a scientific basis, given the fact that more than half of the patients who are tracheotomized in intensive care units die from their underlying disease. The new Tracheotomy Endoscope (TED) is designed to help prevent serious complications in dilatational tracheotomies and facilitate their management. The endoscope has been specifically adapted to meet the require-ments of percutaneous dilatational tracheotomies. It is fully compatible with all current techniques of PDT. The method is easy to learn. The percutaneous dilatational tracheotomy with the Tracheotomy Endoscope is a seven-step procedure: Advantages of the Tracheotomy Endoscope: Injuries to the posterior tracheal wall ar impossible (tracheoesophageal fistulas, pneumothorax). Minor bleeding sites on the tracheal mucosa can be controlled with a specially curved suction-coagulation tube introudeced through the Tracheotomy Endoscope. In cases with heavy bleeding and a risk of aspiration, the rigid indwelling Tracheotomy Endoscope provides a secure route for reintubating the patient with a cuffed endotracheal tube. It also allows for rapid conversion to an open surgical procedure if necessary. All the parts are easy to clean and are autoclavable. This type of endoscopically guided PDT creates an optimal link between the specialties of intensive care medicine and otorhinolaryngology. The Tracheotomy Endoscope (TED) increases the standard of safety in PDT.

Tethered Contactless Mobile Nuclear Environment Monitoring Robot

International Nuclear Information System (INIS)

Choi, S. Y.; Lee, E. S.; Lee, Kun J.; Kim, Su H.; Rim, C. T.

2013-01-01

In fact, the nuclear environment monitoring is significantly crucial for early detection of NPP accident, radiological emergency, the estimation of radiation exposure to nearby residents as well as the long term radioactivity. In the UAE, the nuclear environment monitoring is, however, quite challenging because sampling locations are far from NPPs and the outdoor temperature and humidity are very high for NPP workers to collect soil, air, and water samples. Therefore, nuclear environment monitoring robots (Nubos) are strongly needed for the NPPs in the UAE. The Nubos can be remotely controlled to collect samples in extreme environment instead of NPP workers. Moreover, the Nubos can be unmanned ground vehicles (UGVs), unmanned aerial vehicles (UAVs) and unmanned marine vehicles (UMVs) to collect soil, air, and water samples, respectively. In this paper, the prototype development of UGV type Nubos using power cable for a long distance power delivery, called Tethered contactless mobile Nubo is introduced and validated by experiments. In this paper, the prototype development of Tethered Contactless Mobile (TeCoM) Nubo, which can be powered continuously within several km distance and avoid tangled cable, and the indoor test are finished. As further works, outdoor demonstration and a grand scale R and D proposal of practical Nubo will be proceeded

Tethered Contactless Mobile Nuclear Environment Monitoring Robot

Energy Technology Data Exchange (ETDEWEB)

Choi, S. Y.; Lee, E. S.; Lee, Kun J.; Kim, Su H.; Rim, C. T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2013-05-15

In fact, the nuclear environment monitoring is significantly crucial for early detection of NPP accident, radiological emergency, the estimation of radiation exposure to nearby residents as well as the long term radioactivity. In the UAE, the nuclear environment monitoring is, however, quite challenging because sampling locations are far from NPPs and the outdoor temperature and humidity are very high for NPP workers to collect soil, air, and water samples. Therefore, nuclear environment monitoring robots (Nubos) are strongly needed for the NPPs in the UAE. The Nubos can be remotely controlled to collect samples in extreme environment instead of NPP workers. Moreover, the Nubos can be unmanned ground vehicles (UGVs), unmanned aerial vehicles (UAVs) and unmanned marine vehicles (UMVs) to collect soil, air, and water samples, respectively. In this paper, the prototype development of UGV type Nubos using power cable for a long distance power delivery, called Tethered contactless mobile Nubo is introduced and validated by experiments. In this paper, the prototype development of Tethered Contactless Mobile (TeCoM) Nubo, which can be powered continuously within several km distance and avoid tangled cable, and the indoor test are finished. As further works, outdoor demonstration and a grand scale R and D proposal of practical Nubo will be proceeded.

Stability analysis and trend study of a balloon tethered in a wind, with experimental comparisons

Science.gov (United States)

Redd, L. T.; Bland, S. R.; Bennett, R. M.

1973-01-01

A stability analysis and trend study for a balloon tethered in a steady wind are presented. The linearized, stability-derivative type analysis includes balloon aerodynamics, buoyancy, mass (including apparent mass), and static forces resulting from the tether cable. The analysis has been applied to a balloon 7.64 m in length, and the results are compared with those from tow tests of this balloon. This comparison shows that the analysis gives reasonable predictions for the damping, frequencies, modes of motion, and stability boundaries exhibited by the balloon. A trend study for the 7.64-m balloon was made to illustrate how the stability boundaries are affected by changes in individual stability parameters. The trends indicated in this study may also be applicable to many other tethered-balloon systems.

Tethered by Self-Generated Flow: Mucus String Augmented Feeding Current Generation in Larval Oysters

Science.gov (United States)

Jiang, H.; Wheeler, J.; Anderson, E.

2016-02-01

Marine zooplankton live in a nutritionally dilute environment. To survive, they must process an enormous volume of water relative to their own body volume for food. To achieve this, many zooplankters including copepods, invertebrate larvae, and protists create a feeding current to concentrate and transport food items to their food gathering structures. To enhance the efficiency of the feeding current, these zooplankters often rely on certain "tethering" mechanisms to retard their translational motion for producing a strong feeding current. The tethering force may include excess weight due to gravity, force from attachment to solid surfaces, and drag experienced by strategically placed morphological structures. Larval oysters are known from previous studies to release mucus strings during feeding, presumably for supplying a tethering force to enhance their feeding-current efficiency. But the underlying mechanism is unclear. In this study, we used a high-speed microscale imaging system (HSMIS) to observe the behavior of freely swimming and feeding larval oysters. We also used HSMIS to measure larval imposed feeding currents via a micro-particle image velocimetry (µPIV) technique. HSMIS allows observations along a vertically oriented focal plane in a relatively large water vessel with unprecedented spatial and temporal resolutions. Our high-speed videos show that a feeding larval oyster continuously released a long mucus string into its feeding current that flows downward; the feeding current subsequently dragged the mucus string downward. Analysis of our µPIV data combined with a hydrodynamic model further suggests that the drag force experienced by the mucus string in the feeding current contributes significantly to the tethering force required to generate the feeding current. Thus, mucus strings in larval oysters act as "anchors" in larval self-generated flow to actively tether the feeding larvae.

Scaling effects in spiral capsule robots.

Science.gov (United States)

Liang, Liang; Hu, Rong; Chen, Bai; Tang, Yong; Xu, Yan

2017-04-01

Spiral capsule robots can be applied to human gastrointestinal tracts and blood vessels. Because of significant variations in the sizes of the inner diameters of the intestines as well as blood vessels, this research has been unable to meet the requirements for medical applications. By applying the fluid dynamic equations, using the computational fluid dynamics method, to a robot axial length ranging from 10 -5 to 10 -2  m, the operational performance indicators (axial driving force, load torque, and maximum fluid pressure on the pipe wall) of the spiral capsule robot and the fluid turbulent intensity around the robot spiral surfaces was numerically calculated in a straight rigid pipe filled with fluid. The reasonableness and validity of the calculation method adopted in this study were verified by the consistency of the calculated values by the computational fluid dynamics method and the experimental values from a relevant literature. The results show that the greater the fluid turbulent intensity, the greater the impact of the fluid turbulence on the driving performance of the spiral capsule robot and the higher the energy consumption of the robot. For the same level of size of the robot, the axial driving force, the load torque, and the maximum fluid pressure on the pipe wall of the outer spiral robot were larger than those of the inner spiral robot. For different requirements of the operating environment, we can choose a certain kind of spiral capsule robot. This study provides a theoretical foundation for spiral capsule robots.

Dynamics of an elastic capsule in moderate Reynolds number Poiseuille flow

International Nuclear Information System (INIS)

Shin, Soo Jai; Sung, Hyung Jin

2012-01-01

Highlights: ► Dynamics of a capsule in moderate Re Poiseuille flow were explored numerically. ► Capsule tends to tumbling motion for larger membrane elasticity and higher Re flow. ► Capsule undergoes swinging motion for larger size and aspect ratio of the capsule. ► Capsule tends to migrate to a specific lateral equilibrium as Re increases. ► Equilibrium position varies differently around the transition of the dynamic motion. - Abstract: The dynamic motions and lateral equilibrium positions of a two-dimensional elastic capsule in a Poiseuille flow were explored at moderate Reynolds number (10 ⩽ Re ⩽ 100) as a function of the initial lateral position (y 0 ), Re, aspect ratio (ε), size ratio (λ), membrane stretching coefficient (φ) and bending coefficient (γ). The transition between tank-treading (TT) and swinging (SW) to tumbling (TU) motions was observed and the lateral equilibrium positions of the capsules varied according to the conditions. The initial behavior of the elastic capsule was influenced by variation in the initial lateral position (y 0 ), but the equilibrium position and dynamic motion of the capsule were not affected by such variation. The capsules had a stronger tendency toward TU motion at higher values of Re, φ and γ, whereas the capsules underwent TT or SW motion as the values of ε and λ increased. Under moderate Re Poiseuille flows, capsules tended to migrate across streamlines to a specific equilibrium position. The lateral equilibrium position shifted toward the centerline at larger λ and migrated toward the wall at larger ε,φandγ. As Re increased, the equilibrium position first shifted toward the bottom wall, then toward the channel center. However, different equilibrium position trends were obtained around the SW–TU transition. The capsule undergoing TU motion tended to migrate downward toward the bottom wall more than the capsule undergoing SW motion, all other conditions being similar.

Gastroesophageal reflux disease. Scintigraphic, endoscopic and histologic considerations

Energy Technology Data Exchange (ETDEWEB)

Kault, B.; Halvorsen, T.; Petersen, H.; Grette, K.; Myrvold, H.E.

1986-01-01

Radionucleotide scintigraphy and esophagoscopy with biopsy were carried out in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. GER was visualized by scintigraphy in 86.1% of the patients. Endoscopic and histologic esophagitis were found in 68.1% and 58.4% of the patients, respectively, whereas both examinations taken together showed evidence of esophagitis in 82%. Histologic evidence of esophagitis was found in nearly all patients with severe endoscopic changes, and in 43.7% of the patients with no endoscopic abnormality. Scintigraphic reflux was demonstrated more frequently in the patients with severe endoscopic esophagitis (97.5%) than in those with no or only mild endoscopic changes (78.6%). Scintigraphic reflux was found in 91.5% and 78.5% of the patients with and without histologic evidence of esophagitis. 15 of the 18 patients (83.3%) without endoscopic and histologic abnormalities in the esophagus had scintigraphic evidence of reflux. The present study strongly supports the clinical significance of scintigraphy in GER disease and confirms that esophageal biopsy specimens increase the sensitivity of endoscopic evaluation. 31 refs.

Capsule Shields the Function of Short Bacterial Adhesins

OpenAIRE

Schembri, Mark A.; Dalsgaard, Dorte; Klemm, Per

2004-01-01

Bacterial surface structures such as capsules and adhesins are generally regarded as important virulence factors. Here we demonstrate that capsules block the function of the self-recognizing protein antigen 43 through physical shielding. The phenomenon is not restricted to Escherichia coli but can occur in other gram-negative bacteria. Likewise, we show that other short adhesins exemplified by the AIDA-I protein are blocked by the presence of a capsule. The results support the notion that cap...

Myocardial Infarction Alters Adaptation of the Tethered Mitral Valve

NARCIS (Netherlands)

Dal-Bianco, Jacob P; Aikawa, Elena; Bischoff, Joyce; Guerrero, J Luis; Hjortnaes, Jesper; Beaudoin, Jonathan; Szymanski, Catherine; Bartko, Philipp E; Seybolt, Margo M; Handschumacher, Mark D; Sullivan, Suzanne; Garcia, Michael L; Mauskapf, Adam; Titus, James S; Wylie-Sears, Jill; Irvin, Whitney S; Chaput, Miguel; Messas, Emmanuel; Hagège, Albert A; Carpentier, Alain; Levine, Robert A

2016-01-01

BACKGROUND: In patients with myocardial infarction (MI), leaflet tethering by displaced papillary muscles induces mitral regurgitation (MR), which doubles mortality. Mitral valves (MVs) are larger in such patients but fibrosis sets in counterproductively. The investigators previously reported that

Moisture diffusion and permeability characteristics of hydroxypropylmethylcellulose and hard gelatin capsules.

Science.gov (United States)

Barham, Ahmad S; Tewes, Frederic; Healy, Anne Marie

2015-01-30

The primary objective of this paper is to compare the sorption characteristics of hydroxypropylmethylcellulose (HPMC) and hard gelatin (HG) capsules and their ability to protect capsule contents. Moisture sorption and desorption isotherms for empty HPMC and HG capsules have been investigated using dynamic vapour sorption (DVS) at 25°C. All sorption studies were analysed using the Young-Nelson model equations which distinguishes three moisture sorption types: monolayer adsorption moisture, condensation and absorption. Water vapour diffusion coefficients (D), solubility (S) and permeability (P) parameters of the capsule shells were calculated. ANOVA was performed with the Tukey comparison test to analyse the effect of %RH and capsule type on S, P, and D parameters. The moisture uptake of HG capsules were higher than HPMC capsules at all %RH conditions studied. It was found that values of D and P across HPMC capsules were greater than for HG capsules at 0-40 %RH; whereas over the same %RH range S values were higher for HG than for HPMC capsules. S values decreased gradually as the %RH was increased up to 60% RH. To probe the effect of moisture ingress, spray dried lactose was loaded into capsules. Phase evolution was characterised by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and differential scanning calorimetry (DSC). The capsules under investigation are not capable of protecting spray dried lactose from induced solid state changes as a result of moisture uptake. For somewhat less moisture sensitive formulations, HPMC would appear to be a better choice than HG in terms of protection of moisture induced deterioration. Copyright © 2014 Elsevier B.V. All rights reserved.

Utilization of the capsule out-pile test facilities(2000-2003)

Energy Technology Data Exchange (ETDEWEB)

Cho, M. S.; Oh, J. M.; Cho, Y. G. and others

2003-06-01

Two out-pile test facilities were installed and being utilized for the non-irradiation tests outside the HANARO. The names of the facilities are the irradiation equipment design verification test facilities and the one-channel flow test device. In these facilities, the performance test of all capsules manufactured before loading in the HANARO and the design verification test for newly developed capsules were performed. The tests in these facilities include loading/unloading, pressure drop, endurance and vibration test etc. of capsules. In the period 2000{approx}2003, the performance tests for 8 material capsules of 99M-01K{approx}02M-05U were carried out, and the design verification tests of creep and fuel capsules developed newly were performed. For development of the creep capsule, pressure drop measurement, operation test of heater, T/C, LVDT and stress loading test were performed. In the design stage of the fuel capsule, the endurance and vibration test besides the above mentioned tests were carried out for verification of the safe operation during irradiation test in the HANARO. And in-chimeny bracket and the capsule supporting system were fixed and the flow tubes and the handling tools were manufactured for use at the facilities.

Development of a Tethered Formation Flight Testbed for ISS, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The development of a testbed for the development and demonstration of technologies needed by tethered formation flying satellites is proposed. Such a testbed would...

Materials for advancement of MXER tether design (1000-371), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — There exist a need to develop, identify, and classify various materials that can be used in the fabrication of electrodynamic tethers for various applications. These...

[PACS-based endoscope image acquisition workstation].

Science.gov (United States)

Liu, J B; Zhuang, T G

2001-01-01

A practical PACS-based Endoscope Image Acquisition Workstation is here introduced. By a Multimedia Video Card, the endoscope video is digitized and captured dynamically or statically into computer. This workstation realizes a variety of functions such as the endoscope video's acquisition and display, as well as the editing, processing, managing, storage, printing, communication of related information. Together with other medical image workstation, it can make up the image sources of PACS for hospitals. In addition, it can also act as an independent endoscopy diagnostic system.

Endoscopic treatment of vesicoureteral reflux in pediatric patients

Directory of Open Access Journals (Sweden)

Jong Wook Kim

2013-04-01

Full Text Available Endoscopic treatment is a minimally invasive treatment for managing patients with vesicoureteral reflux (VUR. Although several bulking agents have been used for endoscopic treatment, dextranomer/hyaluronic acid is the only bulking agent currently approved by the U.S. Food and Drug Administration for treating VUR. Endoscopic treatment of VUR has gained great popularity owing to several obvious benefits, including short operative time, short hospital stay, minimal invasiveness, high efficacy, low complication rate, and reduced cost. Initially, the success rates of endoscopic treatment have been lower than that of open antireflux surgery. However, because injection techniques have been developed, a recent study showed higher success rates of endoscopic treatment than open surgery in the treatment of patients with intermediate- and high-grade VUR. Despite the controversy surrounding its effectiveness, endoscopic treatment is considered a valuable treatment option and viable alternative to long-term antibiotic prophylaxis.

Implementation Options for the PROPEL Electrodynamic Tether Demonstration Mission

Science.gov (United States)

Bilen, Sven G.; Johnson, C. Les; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael; Stone, Nobie

2014-01-01

The PROPEL ("Propulsion using Electrodynamics") flight demonstration mission concept will demonstrate the use of an electrodynamic tether (EDT) for generating thrust, which will allow the propulsion system to overcome the limitations of the rocket equation. The mission concept has been developed by a team of government, industry, and academia partners led by NASA Marshall Space Flight Center (MSFC). PROPEL is being designed for versatility of the EDT system with multiple end users in mind and to be flexible with respect to platform. Previously, we reported on a comprehensive mission design for PROPEL with a mission duration of six months or longer with multiple mission goals including demonstration of significant boost, deboost, inclination change, and drag make-up activities. To explore a range of possible configurations, primarily driven by cost considerations, other mission concept designs have been pursued. In partnership with the NASA's Office of Chief Technologist (OCT) Game Changing Program, NASA MSFC Leadership, and the MSFC Advanced Concepts Office, a mission concept design was developed for a near-term EDT propulsion flight validation mission. The Electrodynamic Tether Propulsion Study (ETPS) defined an EDT propulsion system capable of very large delta-V for use on future missions developed by NASA, DoD, and commercial customers. To demonstrate the feasibility of an ETPS, the study focused on a space demonstration mission concept design with configuration of a pair of tethered satellite busses, one of which is the Japanese H-II Transfer Vehicle (HTV). The HTV would fly its standard ISS resupply mission. When resupply mission is complete, the ISS reconfigures and releases the HTV to perform the EDT experiment at safe orbital altitudes below the ISS. Though the focus of this particular mission concept design addresses a scenario involving the HTV or a similar vehicle, the propulsion system's capability is relevant to a number of applications, as noted above

Endoscopic versus surgical drainage treatment of calcific chronic pancreatitis.

Science.gov (United States)

Jiang, Li; Ning, Deng; Cheng, Qi; Chen, Xiao-Ping

2018-04-21

Endoscopic therapy and surgery are both conventional treatments to remove pancreatic duct stones that developed during the natural course of chronic pancreatitis. However, few studies comparing the effect and safety between surgery drainage and endoscopic drainage (plus Extracorporeal Shock Wave Lithotripsy, ESWL).The aim of this study was to compare the benefits between endoscopic and surgical drainage of the pancreatic duct for patients with calcified chronic pancreatitis. A total of 86 patients were classified into endoscopic/ESWL (n = 40) or surgical (n = 46) treatment groups. The medical records of these patients were retrospectively analyzed. Pain recurrence and hospital stays were similar between the endoscopic/ESWL treatment and surgery group. However, endoscopic/ESWL treatment yielded significantly lower medical expense and less complications compared with the surgical treatment. In selective patients, endoscopic/ESWL treatment could achieve comparable efficacy to the surgical treatment. With lower medical expense and less complications, endoscopic/ESWL treatment would be much preferred to be the initial treatment of choice for patients with calcified chronic pancreatitis. Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Endoscopic and keyhole endoscope-assisted neurosurgical approaches: a qualitative survey on technical challenges and technological solutions.

Science.gov (United States)

Marcus, Hani J; Cundy, Thomas P; Hughes-Hallett, Archie; Yang, Guang-Zhong; Darzi, Ara; Nandi, Dipankar

2014-10-01

The literature reflects a resurgence of interest in endoscopic and keyhole endoscope-assisted neurosurgical approaches as alternatives to conventional microsurgical approaches in carefully selected cases. The aim of this study was to assess the technical challenges of neuroendoscopy, and the scope for technological innovations to overcome these barriers. All full members of the Society of British Neurosurgeons (SBNS) were electronically invited to participate in an online survey. The open-ended structured survey asked three questions; firstly, whether the surgeon presently utilises or has experience with endoscopic or endoscope-assisted approaches; secondly, what they consider to be the major technical barriers to adopting such approaches; and thirdly, what technological advances they foresee improving safety and efficacy in the field. Responses were subjected to a qualitative research method of multi-rater emergent theme analysis. Three clear themes emerged: 1) surgical approach and better integration with image-guidance systems (20%), 2) intra-operative visualisation and improvements in neuroendoscopy (49%), and 3) surgical manipulation and improvements in instruments (74%). The analysis of responses to our open-ended survey revealed that although opinion was varied three major themes could be identified. Emerging technological advances such as augmented reality, high-definition stereo-endoscopy, and robotic joint-wristed instruments may help overcome the technical difficulties associated with neuroendoscopic approaches. Results of this qualitative survey provide consensus amongst the technology end-user community such that unambiguous goals and priorities may be defined. Systems integrating these advances could improve the safety and efficacy of endoscopic and endoscope-assisted neurosurgical approaches.

Asymptomatic Esophageal Varices Should Be Endoscopically Treated

Directory of Open Access Journals (Sweden)

Nib Soehendra

1998-01-01

Full Text Available Endoscopic treatment has generally been accepted in the management of bleeding esophageal varices. Both the control of acute variceal bleeding and elective variceal eradication to prevent recurrent bleeding can be achieved via endoscopic methods. In contrast to acute and elective treatment, the role of endoscopic therapy in asymptomatic patients who have never had variceal bleeding remains controversial because of the rather disappointing results obtained from prophylactic sclerotherapy. Most published randomized controlled trials showed that prophylactic sclerotherapy had no effect on survival. In some studies, neither survival rate nor bleeding risk was improved. In this article, the author champions the view that asymptomatic esophageal varices should be endoscopically treated.

Development of Multiple Capsule Robots in Pipe

Directory of Open Access Journals (Sweden)

Shuxiang Guo

2018-05-01

Full Text Available Swallowable capsule robots which travel in body cavities to implement drug delivery, minimally invasive surgery, and diagnosis have provided great potential for medical applications. However, the space constraints of the internal environment and the size limitations of the robots are great challenges to practical application. To address the fundamental challenges of narrow body cavities, a different-frequency driven approach for multiple capsule robots with screw structure manipulated by external electromagnetic field is proposed in this paper. The multiple capsule robots are composed of driven permanent magnets, joint permanent magnets, and a screw body. The screw body generates a propulsive force in a fluidic environment. Moreover, robots can form new constructions via mutual docking and release. To provide manipulation guidelines for active locomotion, a dynamic model of axial propulsion and circumferential torque is established. The multiple start and step-out frequencies for multiple robots are defined theoretically. Moreover, the different-frequency driven approach based on geometrical parameters of screw structure and the overlap angles of magnetic polarities is proposed to drive multiple robots in an identical electromagnetic field. Finally, two capsule robots were prototyped and experiments in a narrow pipe were conducted to verify the different motions such as docking, release, and cooperative locomotion. The experimental results demonstrated the validity of the driven approach for multiple capsule robots in narrow body cavities.

Folding of multidomain proteins: biophysical consequences of tethering even in apparently independent folding.

Science.gov (United States)

Arviv, Oshrit; Levy, Yaakov

2012-12-01

Most eukaryotic and a substantial fraction of prokaryotic proteins are composed of more than one domain. The tethering of these evolutionary, structural, and functional units raises, among others, questions regarding the folding process of conjugated domains. Studying the folding of multidomain proteins in silico enables one to identify and isolate the tethering-induced biophysical determinants that govern crosstalks generated between neighboring domains. For this purpose, we carried out coarse-grained and atomistic molecular dynamics simulations of two two-domain constructs from the immunoglobulin-like β-sandwich fold. Each of these was experimentally shown to behave as the "sum of its parts," that is, the thermodynamic and kinetic folding behavior of the constituent domains of these constructs seems to occur independently, with the folding of each domain uncoupled from the folding of its partner in the two-domain construct. We show that the properties of the individual domains can be significantly affected by conjugation to another domain. The tethering may be accompanied by stabilizing as well as destabilizing factors whose magnitude depends on the size of the interface, the length, and the flexibility of the linker, and the relative stability of the domains. Accordingly, the folding of a multidomain protein should not be viewed as the sum of the folding patterns of each of its parts, but rather, it involves abrogating several effects that lead to this outcome. An imbalance between these effects may result in either stabilization or destabilization owing to the tethering. Copyright © 2012 Wiley Periodicals, Inc.

Dynamic computed tomography of hepatocellular carcinoma with particular reference to capsule

Energy Technology Data Exchange (ETDEWEB)

Otsuji, Hideaki [Nara Prefectural Hospital (Japan); Uchida, Hideo; Ohishi, H

1983-11-01

Dynamic CT of 117 hepatocellular carcinoma was analyzed about the capsule. Capsules were detected in 57 cases (49%) and they were classified into three types. The tumor showed high density during 15 to 26 sec after bolus injection of conrast medium, but the capsule was not enhanced. Incidence of the capsule enhanced as ring high density was 73% during 37 to 90 sec and over 90% after 4 min. Dynamic CT was very useful in the elucidation of hemodynamics of capsules of hepatocellular carcinoma.

Results from annual testing of ARECO cesium capsules from 1990-1994

Energy Technology Data Exchange (ETDEWEB)

Lundeen, J.E.

1994-10-01

The purpose of this report is to compile the results of the cesium capsule inspections and testing at the Applied Radiant Energy Corporation (ARECO) facility in Lynchburg, VA, performed in 1990, 1991, 1992, 1993, and 1994. The 25 cesium capsules at the ARECO facility were visually identified and clunk tested. A Go/No Go gauge test was required for capsules failing the clunk test. A visual inspection of capsules was required for the initial testing (1990). All 25 capsules passed the inspections and testing each year.

Clinical curative effect of electroacupuncture combined with zhizhukuanzhong capsules for treating gastroesophageal reflux disease.

Science.gov (United States)

Zhang, Chaoxian; Guo, Like; Guo, Xiaofeng; Guo, Xiaohe; Li, Guangyan

2012-09-01

To study the clinical curative effect, safety and mechanism of action of electroacupuncture combined with Zhizhukuanzhong capsules (ZZKZC) in treating gastroesophageal reflux disease (GERD). A total of 480 patients with confirmed GERD were randomly divided into four groups: the electroacupuncture group, the ZZKZC group, the combined therapy group, and the control group, with 120 cases in each group. Each case in the electroacupuncture group was treated with electroacupuncture on Zusanli (ST 36), Zhongwan (CV 12), Neiguan (PC 6),Taichong (LR 3) and Gongsun (SP 4) once daily for 6 weeks. Each case in the ZZKZC group was treated with oral administration of 1.29 g ZZKZC three times daily. The combined therapy group had electroacupuncture and ZZKZC. The control group was given oral administration of 5 mg mosapride three times and 20 mg pantoprazole twice daily. The 24-hour intraesophageal total number of reflux episodes with pH or = 0.14), the number of long-term (> or = 5 min) reflux episodes, the percentage of upright time, the percentage of supine time, the percentage of total time of pH or = 0.14), endoscopic grading score, symptom score, quality of life score, and adverse reactions were observed before treatment, at the end of treatment and 54 weeks after treatment in the four groups. The 24-hour intraesophageal pH and bile reflux, endoscopic grading score and symptom score were all significantly decreased at the end of treatment in every group, while the scores of 8 dimensions of quality of life were all increased compared with those before treatment (Pelectroacupuncture group 54 weeks after treatment compared with the end of treatment (P>0.05); however, these indices all significantly deteriorated in the ZZKZC and control groups (P>0.05). The short and long-term total efficacy rates in the combined therapy group showed significant superiority to those in the other groups (PElectroacupuncture and ZZKZC play an important role in inhibiting intraesophageal acid and

Endoscopic Management of an Intramural Sinus Leak After Per- Oral Endoscopic Myotomy

Science.gov (United States)

Al Taii, Haider; Confer, Bradley; Gabbard, Scott; Kroh, Matthew; Jang, Sunguk; Rodriguez, John; Parsi, Mansour A.; Vargo, John J.; Ponsky, Jeffrey

2016-01-01

Per-oral endoscopic myotomy (POEM) was developed less than a decade ago for the treatment of achalasia. Its minimally invasive approach and the favorable short-term outcome have led to rapid adoption of the technique throughout the world. As with any new technique, there will be adverse events, and it is important that effective treatments for these adverse events be discussed. We present a case of successful endoscopic management of an intramural sinus leak after a POEM procedure using tandem fully covered esophageal stents. PMID:27921057

Biomimetic chimeric peptide-tethered hydrogels for human mesenchymal stem cell delivery.

Science.gov (United States)

Shim, Gayong; Kim, Gunwoo; Choi, Junhyeok; Yi, TacGhee; Cho, Yun Kyoung; Song, Sun Uk; Byun, Youngro; Oh, Yu-Kyoung

2015-12-01

Here, we report a chimeric peptide-tethered fibrin hydrogel scaffold for delivery of human mesenchymal stem cells (hMSC). Osteopontin-derived peptide (OP) was used as an hMSC-tethering moiety. OP showed hMSC adhesion properties and enhanced hMSC proliferation. A natural fibrin-binding protein-derived peptide (FBP) was tested for its ability to tether hMSC to the fibrin gel matrix. FBP loading on fibrin gels was 8.2-fold higher than that of a scrambled peptide (scFBP). FBP-loaded fibrin gels were retained at injection sites longer than scFBP-loaded fibrin gels, showing a 15.9-fold higher photon intensity of fluorescent FBP-grafted fibrin gels than fluorescent scFBP-loaded fibrin gels 48 h after injection. On the basis of the fibrin gel-binding properties of FBP and the hMSC-binding and proliferation-supporting properties of OP, we constructed chimeric peptides containing FBP and OP linked with a spacer (FBPsOP). Four days after transplantation, the survival of hMSC in FBPsOP-grafted fibrin gels was 3.9-fold higher than hMSC in fibrin gels alone. Our results suggest the potential of FBPsOP-grafted fibrin gels as a bioactive delivery system for enhanced survival of stem cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Acquisition of Human Operation Characteristics for Kite-based Tethered Flying Robot using Human Operation Data

OpenAIRE

Todoroki, Chiaki; Takahashi, Yasutake; Nakamura, Takayuki

2015-01-01

This paper shows human skill acquisition systems to control the kite-based tethered flying robot. The kite-based tethered flying robot has been proposed as a flying observation system with long-term activity capability[1]. It is a relatively new system and aimed to complement other information gathering systems using a balloon or an air vehicle. This paper shows some approaches of human operation characteristics acquisition based on fuzzy learning controller, knearest neighbor algorithm, and ...

Wide-field phase imaging for the endoscopic detection of dysplasia and early-stage esophageal cancer

Science.gov (United States)

Fitzpatrick, C. R. M.; Gordon, G. S. D.; Sawyer, T. W.; Wilkinson, T. D.; Bohndiek, S. E.

2018-02-01

Esophageal cancer has a 5-year survival rate below 20%, but can be curatively resected if it is detected early. At present, poor contrast for early lesions in white light imaging leads to a high miss rate in standard-of- care endoscopic surveillance. Early lesions in the esophagus, referred to as dysplasia, are characterized by an abundance of abnormal cells with enlarged nuclei. This tissue has a different refractive index profile to healthy tissue, which results in different light scattering properties and provides a source of endogenous contrast that can be exploited for advanced endoscopic imaging. For example, point measurements of such contrast can be made with scattering spectroscopy, while optical coherence tomography generates volumetric data. However, both require specialist interpretation for diagnostic decision making. We propose combining wide-field phase imaging with existing white light endoscopy in order to provide enhanced contrast for dysplasia and early-stage cancer in an image format that is familiar to endoscopists. Wide-field phase imaging in endoscopy can be achieved using coherent illumination combined with phase retrieval algorithms. Here, we present the design and simulation of a benchtop phase imaging system that is compatible with capsule endoscopy. We have undertaken preliminary optical modelling of the phase imaging setup, including aberration correction simulations and an investigation into distinguishing between different tissue phantom scattering coefficients. As our approach is based on phase retrieval rather than interferometry, it is feasible to realize a device with low-cost components for future clinical implementation.

High-gain capsule design for the HIDIF project

International Nuclear Information System (INIS)

Honrubia, J.J.; Cerrada, J.A.; Gomez, R.

2000-01-01

A high-gain capsule has been designed for the HIDIF project. The goal has been to relax the accelerator requirements by using a radiation pulse with lower peak temperature (220 eV) than previous designs (260 eV). The ablator material is beryllium doped with a very low concentration (0.2 atom %) of copper. The capsule absorbs 1.3 MJ and yields, approximately, 450 MJ in I-D simulations. The effect of the opacity of the ablator on capsule performance has been studied in detail. (authors)

Endoscopic versus open bursectomy of lateral malleolar bursitis.

Science.gov (United States)

Choi, Jae Hyuck; Lee, Kyung Tai; Lee, Young Koo; Kim, Dong Hyun; Kim, Jeong Ryoul; Chung, Woo Chull; Cha, Seung Do

2012-06-01

Compare the result of endoscopic versus open bursectomy in lateral malleolar bursitis. Prospective evaluation of 21 patients (22 ankles) undergoing either open or endoscopic excision of lateral malleolar bursitis. The median age was 64 (38-79) years old. The median postoperative follow-up was 15 (12-18) months. Those patients undergoing endoscopic excision showed a higher satisfaction rate (excellent 9, good 2) than open excision (excellent 4, good 3, fair 1). The wounds also healed earlier in the endoscopic group although the operation time was slightly longer. One patient in the endoscopic group had recurrence of symptoms but complications in the open group included one patient with skin necrosis, one patient with wound dehiscence, and two patients of with superficial peroneal nerve injury. Endoscopic resection of the lateral malleolar bursitis is a promising technique and shows favorable results compared to the open resection. Therapeutic studies-Investigating the result of treatment, Level II.

Ultrasound-assisted endoscopic partial plantar fascia release.

Science.gov (United States)

Ohuchi, Hiroshi; Ichikawa, Ken; Shinga, Kotaro; Hattori, Soichi; Yamada, Shin; Takahashi, Kazuhisa

2013-01-01

Various surgical treatment procedures for plantar fasciitis, such as open surgery, percutaneous release, and endoscopic surgery, exist. Skin trouble, nerve disturbance, infection, and persistent pain associated with prolonged recovery time are complications of open surgery. Endoscopic partial plantar fascia release offers the surgeon clear visualization of the anatomy at the surgical site. However, the primary medial portal and portal tract used for this technique have been shown to be in close proximity to the posterior tibial nerves and their branches, and there is always the risk of nerve damage by introducing the endoscope deep to the plantar fascia. By performing endoscopic partial plantar fascia release under ultrasound assistance, we could dynamically visualize the direction of the endoscope and instrument introduction, thus preventing nerve damage from inadvertent insertion deep to the fascia. Full-thickness release of the plantar fascia at the ideal position could also be confirmed under ultrasound imaging. We discuss the technique for this new procedure.

Capsule Development and Utilization for Material Irradiation Tests

International Nuclear Information System (INIS)

Kang, Young Hwan; Kim, B. G.; Joo, K. N.

2003-05-01

The objective of this project was to establish basic capsule irradiation technology using the multi-purpose research reactor [HANARO] to eventually support national R and D projects of advanced fuel and materials related to domestic nuclear power plants and next generation reactors. There are several national nuclear projects in KAERI, which require several irradiation tests to investigate in-pile behavior of nuclear reactor fuel and materials for the R and D of several types of fuels such as advanced PWR and DUPIC fuels and for the R and D of structural materials such as RPV(reactor pressure vessel) steel, Inconel, zirconium alloy, and stainless steel. At the moment, internal and external researchers in institutes, industries and universities are interested in investigating the irradiation characteristics of materials using the irradiation facilities of HANARO. For these kinds of material irradiation tests, it is important to develop various capsules using our own techniques. The development of capsules requires several leading-edge technologies and our own experiences related to design and fabrication. In the second phase from April 1,2000 to March 31, 2003, the utilization technologies were developed using various sensors for the measurements of temperature, pressure and displacement, and instrumented capsule technologies for the required fuel irradiation tests were developed. In addition, the improvement of the existing capsule technologies and the development of an in-situ measurable creep capsule for specific purposes were done to meet the various requirements of users

Crosslinking studies in gelatin capsules treated with formaldehyde and in capsules exposed to elevated temperature and humidity.

Science.gov (United States)

Ofner, C M; Zhang, Y E; Jobeck, V C; Bowman, B J

2001-01-01

Incomplete in vitro capsule shell dissolution and subsequent drug release problems have recently received attention. A modified USP dissolution method was used to follow capsule shell dissolution, and a 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay was used to follow loss of epsilon-amino groups to study this shell dissolution problem postulated to be due to gelatin crosslinking. The dissolution problems were simulated using hard gelatin capsule (HGC) shells previously treated with formaldehyde to crosslink the gelatin. These methods were also used to study the effect of uncrosslinked HGC stored under stressed conditions (37 degrees C and 81% RH) with or without the presence of soft gelatin capsule shells (SGC). A 120 ppm formaldehyde treatment reduced gelatin shell dissolution to 8% within 45 min in water at 37 degrees C. A 200 ppm treatment reduced gelatin epsilon-amino groups to 83% of the original uncrosslinked value. The results also support earlier reports of non-amino group crosslinking by formaldehyde in gelatin. Under stressed conditions, HGC stored alone showed little change over 21 weeks. However, by 12 to 14 weeks, the HGC exposed to SGC showed a 23% decrease in shell dissolution and an 8% decrease in the number of epsilon-amino groups. These effects on the stressed HGC are ascribed to a volatile agent from SGC shells, most likely formaldehyde, that crosslinked nearby HGC shells. This report also includes a summary of the literature on agents that reduce gelatin and capsule shell dissolution and the possible mechanisms of this not-so-simple problem. Copyright 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90: 79-88, 2001

Control by damping Injection of Electrodynamic Tether System in an Inclined Orbit

DEFF Research Database (Denmark)

Larsen, Martin Birkelund; Blanke, Mogens

2009-01-01

dynamical system. Based on this model, a nonlinear controller is designed that will make the system asymptotically stable around its open-loop equilibrium. The control scheme handles the time-varying nature of the system in a suitable manner resulting in a large operational region. The performance...... of the closed loop system is treated using Floquet theory, investigating the closed loop properties for their dependency of the controller gain and orbit inclination.......Control of a satellite system with an electrodynamic tether as actuator is a time-periodic and underactuated control problem. This paper considers the tethered satellite in a Hamiltonian framework and determines a port-controlled Hamiltonian formulation that adequately describes the nonlinear...

Contrast-enhanced endoscopic ultrasonography

DEFF Research Database (Denmark)

Reddy, Nischita K; Ioncica, Ana Maria; Saftoiu, Adrian

2011-01-01

Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...

Is endoscopic nodular gastritis associated with premalignant lesions?

Science.gov (United States)

Niknam, R; Manafi, A; Maghbool, M; Kouhpayeh, A; Mahmoudi, L

2015-06-01

Nodularity on the gastric mucosa is occasionally seen in general practice. There is no consensus about the association of nodular gastritis and histological premalignant lesions. This study is designed to investigate the prevalence of histological premalignant lesions in dyspeptic patients with endoscopic nodular gastritis. Consecutive patients with endoscopic nodular gastritis were compared with an age- and sex-matched control group. Endoscopic nodular gastritis was defined as a miliary nodular appearance of the gastric mucosa on endoscopy. Biopsy samples of stomach tissue were examined for the presence of atrophic gastritis, intestinal metaplasia, and dysplasia. The presence of Helicobacter pylori infection was determined by histology. From 5366 evaluated patients, a total of 273 patients with endoscopic nodular gastritis and 1103 participants as control group were enrolled. H. pylori infection was detected in 87.5% of the patients with endoscopic nodular gastritis, whereas 73.8% of the control group were positive for H. pylori (p gastritis were significantly higher than in the control group. Prevalence of atrophic gastritis and complete intestinal metaplasia were also more frequent in patients with endoscopic nodular gastritis than in the control group. Dysplasia, incomplete intestinal metaplasia and H. pylori infection are significantly more frequent in patients with endoscopic nodular gastritis. Although further studies are needed before a clear conclusion can be reached, we suggest that endoscopic nodular gastritis might serve as a premalignant lesion and could be biopsied in all patients for the possibility of histological premalignancy, in addition to H. pylori infection.

A Correlational Analysis of Tethered Swimming, Swim Sprint Performance and Dry-land Power Assessments.

Science.gov (United States)

Loturco, I; Barbosa, A C; Nocentini, R K; Pereira, L A; Kobal, R; Kitamura, K; Abad, C C C; Figueiredo, P; Nakamura, F Y

2016-03-01

Swimmers are often tested on both dry-land and in swimming exercises. The aim of this study was to test the relationships between dry-land, tethered force-time curve parameters and swimming performances in distances up to 200 m. 10 young male high-level swimmers were assessed using the maximal isometric bench-press and quarter-squat, mean propulsive power in jump-squat, squat and countermovement jumps (dry-land assessments), peak force, average force, rate of force development (RFD) and impulse (tethered swimming) and swimming times. Pearson product-moment correlations were calculated among the variables. Peak force and average force were very largely correlated with the 50- and 100-m swimming performances (r=- 0.82 and -0.74, respectively). Average force was very-largely/largely correlated with the 50- and 100-m performances (r=- 0.85 and -0.67, respectively). RFD and impulse were very-largely correlated with the 50-m time (r=- 0.72 and -0.76, respectively). Tethered swimming parameters were largely correlated (r=0.65 to 0.72) with mean propulsive power in jump-squat, squat-jump and countermovement jumps. Finally, mean propulsive power in jump-squat was largely correlated (r=- 0.70) with 50-m performance. Due to the significant correlations between dry-land assessments and tethered/actual swimming, coaches are encouraged to implement strategies able to increase leg power in sprint swimmers. © Georg Thieme Verlag KG Stuttgart · New York.

Capsule-Fixated Intraocular Lens Implantation in Small Pupil Cases.

Science.gov (United States)

Schojai, Merita; Schultz, Tim; Burkhard Dick, H

2017-08-01

To describe a new technique for implantation of capsule-fixated intraocular lenses (IOLs) (FEMTIS; Oculentis, Berlin, Germany) in patients with small pupils. In 4 eyes with small pupils, an anterior capsule-fixated IOL was implanted into the capsular bag after femtosecond laser treatment. The two large and two small flaps of the IOL were elevated to the front of the iris and the anterior capsule. Finally, the iris was flipped over the flaps to ensure a fixation of the capsule inside of the capsulotomy. In all cases, the implantation of anterior capsule-fixated IOLs was possible. No complications occurred during surgery or within the first months after surgery. With the described technique, capsulefixated IOLs can be implanted in eyes with small pupil easily and safely. This type of IOL has great potential to improve the refractive outcome by better prediction of the postoperative IOL position and eliminating IOL rotation after cataract surgery. [J Refract Surg. 2017;33(8):568-570.]. Copyright 2017, SLACK Incorporated.

Triggered Release from Polymer Capsules

Energy Technology Data Exchange (ETDEWEB)

Esser-Kahn, Aaron P. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Odom, Susan A. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Sottos, Nancy R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Materials Science and Engineering; White, Scott R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Aerospace Engineering; Moore, Jeffrey S. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry

2011-07-06

Stimuli-responsive capsules are of interest in drug delivery, fragrance release, food preservation, and self-healing materials. Many methods are used to trigger the release of encapsulated contents. Here we highlight mechanisms for the controlled release of encapsulated cargo that utilize chemical reactions occurring in solid polymeric shell walls. Triggering mechanisms responsible for covalent bond cleavage that result in the release of capsule contents include chemical, biological, light, thermal, magnetic, and electrical stimuli. We present methods for encapsulation and release, triggering methods, and mechanisms and conclude with our opinions on interesting obstacles for chemically induced activation with relevance for controlled release.

Single-Molecule Tethered Particle Motion: Stepwise Analyses of Site-Specific DNA Recombination

Directory of Open Access Journals (Sweden)

Hsiu-Fang Fan

2018-05-01

Full Text Available Tethered particle motion/microscopy (TPM is a biophysical tool used to analyze changes in the effective length of a polymer, tethered at one end, under changing conditions. The tether length is measured indirectly by recording the Brownian motion amplitude of a bead attached to the other end. In the biological realm, DNA, whose interactions with proteins are often accompanied by apparent or real changes in length, has almost exclusively been the subject of TPM studies. TPM has been employed to study DNA bending, looping and wrapping, DNA compaction, high-order DNA–protein assembly, and protein translocation along DNA. Our TPM analyses have focused on tyrosine and serine site-specific recombinases. Their pre-chemical interactions with DNA cause reversible changes in DNA length, detectable by TPM. The chemical steps of recombination, depending on the substrate and the type of recombinase, may result in a permanent length change. Single molecule TPM time traces provide thermodynamic and kinetic information on each step of the recombination pathway. They reveal how mechanistically related recombinases may differ in their early commitment to recombination, reversibility of individual steps, and in the rate-limiting step of the reaction. They shed light on the pre-chemical roles of catalytic residues, and on the mechanisms by which accessory proteins regulate recombination directionality.

What we have learned and what to expect from capsule endoscopy.

Science.gov (United States)

Adler, Samuel N; Bjarnason, Ingvar

2012-10-16

Capsule endoscopy was conceived by Gabriel Iddan and Paul Swain independently two decades ago. These applications include but are not limited to Crohn's disease of the small bowel, occult gastrointestinal bleeding, non steroidal anti inflammatory drug induced small bowel disease, carcinoid tumors of the small bowel, gastro intestinal stromal tumors of the small bowel and other disease affecting the small bowel. Capsule endoscopy has been compared to traditional small bowel series, computerized tomography studies and push enteroscopy. The diagnostic yield of capsule endoscopy has consistently been superior in the diagnosis of small bowel disease compared to the competing methods (small bowel series, computerized tomography, push enteroscopy) of diagnosis. For this reason capsule endoscopy has enjoyed a meteoric success. Image quality has been improved with increased number of pixels, automatic light exposure adaptation and wider angle of view. Further applications of capsule endoscopy of other areas of the digestive tract are being explored. The increased transmission rate of images per second has made capsule endoscopy of the esophagus a realistic possibility. Technological advances that include a double imager capsule with a nearly panoramic view of the colon and a variable frame rate adjusted to the movement of the capsule in the colon have made capsule endoscopy of the colon feasible. The diagnostic rate for the identification of patients with polyps equal to or larger than 6 mm is high. Future advances in technology and biotechnology will lead to further progress. Capsule endoscopy is following the successful modern trend in medicine that replaces invasive tests with less invasive methodology.

Quinine-Promoted, Enantioselective Boron-Tethered Diels-Alder Reaction by Anomeric Control of Transition State Conformation.

Science.gov (United States)

Scholl, Katie; Dillashaw, John; Timpy, Evan; Lam, Yu-Hong; DeRatt, Lindsey; Benton, Tyler R; Powell, Jacqueline P; Houk, Kendall N; Morgan, Jeremy B

2018-05-01

Diels-Alder reactions of tethered vinyl-metal species offer the opportunity to fashion highly functionalized diol intermediates for synthesis. We have developed the first enantioselective boron-tethered Diels-Alder reaction using quinine as a chiral promoter. Quinine recovery, enantioselectivity enhancement, and manipulation of the cyclohexene core are also investigated. DFT modeling calculations confirm the role of quinine as a bidentate ligand enhancing reaction rates. The enantioselectivity of the cycloaddition is proposed to originate from a boron-centered anomeric effect.

A technical review of flexible endoscopic multitasking platforms.

Science.gov (United States)

Yeung, Baldwin Po Man; Gourlay, Terence

2012-01-01

Further development of advanced therapeutic endoscopic techniques and natural orifice translumenal endoscopic surgery (NOTES) requires a powerful flexible endoscopic multitasking platform. Medline search was performed to identify literature relating to flexible endoscopic multitasking platform from year 2004-2011 using keywords: Flexible endoscopic multitasking platform, NOTES, Instrumentation, Endoscopic robotic surgery, and specific names of various endoscopic multitasking platforms. Key articles from articles references were reviewed. Flexible multitasking platforms can be classified as either mechanical or robotic. Purely mechanical systems include the dual channel endoscope (DCE) (Olympus), R-Scope (Olympus), the EndoSamurai (Olympus), the ANUBIScope (Karl-Storz), Incisionless Operating Platform (IOP) (USGI), and DDES system (Boston Scientific). Robotic systems include the MASTER system (Nanyang University, Singapore) and the Viacath (Hansen Medical). The DCE, the R-Scope, the EndoSamurai and the ANUBIScope have integrated visual function and instrument manipulation function. The IOP and DDES systems rely on the conventional flexible endoscope for visualization, and instrument manipulation is integrated through the use of a flexible, often lockable, multichannel access device. The advantage of the access device concept is that it allows optics and instrument dissociation. Due to the anatomical constrains of the pharynx, systems are designed to have a diameter of less than 20 mm. All systems are controlled by traction cable system actuated either by hand or by robotic machinery. In a flexible system, this method of actuation inevitably leads to significant hysteresis. This problem will be accentuated with a long endoscope such as that required in performing colonic procedures. Systems often require multiple operators. To date, the DCE, the R-Scope, the IOP, and the Viacath system have data published relating to their application in human. Alternative forms of

Safety evaluation for packaging (onsite) singly encapsulated cesium chloride capsules

International Nuclear Information System (INIS)

Smyth, W.W.

1997-01-01

Three nonstandard Waste Encapsulation and Storage Facility (WESF) cesium chloride capsules are being shipped from WESF (225B building) to the 324 building. They would normally be shipped in the Beneficial Uses Shipping System (BUSS) cask under its US Department of Energy (DOE) license (DOE 1996), but these capsules are nonstandard: one has a damaged or defective weld in the outer layer of encapsulation, and two have the outer encapsulation removed. The 3 capsules, along with 13 other capsules, will be overpacked in the 324 building to meet the requirements for storage in WESF's pool

UV-Curable Hybrid Nanocomposite Coating to Protect Tether Polymer Materials, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — To address the NASA need for coatings to protect and strengthen tether materials for Momentum-exchange Electrodynamic Reboost (MXER) technology, Luminit, LLC,...

Usefulness of combined percutaneous-endoscopic rendezvous techniques after failed therapeutic endoscopic retrograde cholangiography in the era of endoscopic ultrasound guided rendezvous.

Science.gov (United States)

Yang, Min Jae; Kim, Jin Hong; Hwang, Jae Chul; Yoo, Byung Moo; Kim, Soon Sun; Lim, Sun Gyo; Won, Je Hwan

2017-12-01

The rendezvous approach is a salvage technique after failure of endoscopic retrograde cholangiography (ERC). In certain circumstances, percutaneous-endoscopic rendezvous (PE-RV) is preferred, and endoscopic ultrasound-guided rendezvous (EUS-RV) is difficult to perform. We aimed to evaluate PE-RV outcomes, describe the PE-RV techniques, and identify potential indications for PE-RV over EUS-RV.Retrospective analysis was conducted of a prospectively designed ERC database between January 2005 and December 2016 at a tertiary referral center including cases where PE-RV was used as a salvage procedure after ERC failure.During the study period, PE-RV was performed in 42 cases after failed therapeutic ERC; 15 had a surgically altered enteric anatomy. The technical success rate of PE-RV was 92.9% (39/42), with a therapeutic success rate of 88.1% (37/42). Potential indications for PE-RV over EUS-RV were identified in 23 cases, and either PE-RV or EUS-RV could have effectively been used in 19 cases. Endoscopic bile duct access was successfully achieved with PE-RV in 39 cases with accessible biliary orifice using one of PE-RV cannulation techniques (classic, n = 11; parallel, n = 19; and adjunctive maneuvers, n = 9).PE-RV uses a unique technology and has clinical indications that distinguish it from EUS-RV. Therefore, PE-RV can still be considered a useful salvage technique for the treatment of biliary obstruction after ERC failure.

Capsule shields the function of short bacterial adhesins

DEFF Research Database (Denmark)

Schembri, Mark; Dalsgaard, D.; Klemm, Per

2004-01-01

Bacterial surface structures such as capsules and adhesins are generally regarded as important virulence factors. Here we demonstrate that capsules block the function of the self-recognizing protein antigen 43 through physical shielding. The phenomenon is not restricted to Escherichia coli but can...

Toward an integrated model of capsule regulation in Cryptococcus neoformans.

Directory of Open Access Journals (Sweden)

Brian C Haynes

2011-12-01

Full Text Available Cryptococcus neoformans is an opportunistic fungal pathogen that causes serious human disease in immunocompromised populations. Its polysaccharide capsule is a key virulence factor which is regulated in response to growth conditions, becoming enlarged in the context of infection. We used microarray analysis of cells stimulated to form capsule over a range of growth conditions to identify a transcriptional signature associated with capsule enlargement. The signature contains 880 genes, is enriched for genes encoding known capsule regulators, and includes many uncharacterized sequences. One uncharacterized sequence encodes a novel regulator of capsule and of fungal virulence. This factor is a homolog of the yeast protein Ada2, a member of the Spt-Ada-Gcn5 Acetyltransferase (SAGA complex that regulates transcription of stress response genes via histone acetylation. Consistent with this homology, the C. neoformans null mutant exhibits reduced histone H3 lysine 9 acetylation. It is also defective in response to a variety of stress conditions, demonstrating phenotypes that overlap with, but are not identical to, those of other fungi with altered SAGA complexes. The mutant also exhibits significant defects in sexual development and virulence. To establish the role of Ada2 in the broader network of capsule regulation we performed RNA-Seq on strains lacking either Ada2 or one of two other capsule regulators: Cir1 and Nrg1. Analysis of the results suggested that Ada2 functions downstream of both Cir1 and Nrg1 via components of the high osmolarity glycerol (HOG pathway. To identify direct targets of Ada2, we performed ChIP-Seq analysis of histone acetylation in the Ada2 null mutant. These studies supported the role of Ada2 in the direct regulation of capsule and mating responses and suggested that it may also play a direct role in regulating capsule-independent antiphagocytic virulence factors. These results validate our experimental approach to dissecting

Balancing the shortcomings of microscope and endoscope: endoscope-assisted technique in microsurgical removal of recurrent epidermoid cysts in the posterior fossa.

Science.gov (United States)

Ebner, F H; Roser, F; Thaher, F; Schittenhelm, J; Tatagiba, M

2010-10-01

We report about endoscope-assisted surgery of epidermoid cysts in the posterior fossa focusing on the application of neuro-endoscopy and the clinical outcome in cases of recurrent epidermoid cysts. 25 consecutively operated patients with an epidermoid cyst in the posterior fossa were retrospectively analysed. Surgeries were performed both with an operating microscope (OPMI Pentero or NC 4, Zeiss Company, Oberkochen, Germany) and endoscopic equipment (4 mm rigid endoscopes with 30° and 70° optics; Karl Storz Company, Tuttlingen, Germany) under continuous intraoperative monitoring. Surgical reports and DVD-recordings were evaluated for identification of adhesion areas and surgical details. 7 (28%) of the 25 patients were recurrences of previously operated epidermoid cysts. Mean time to recurrence was 17 years (8-22 years). In 5 cases the endoscope was used as an adjunctive tool for inspection/endoscope-assisted removal of remnants. The effective time of use of the endoscope was limited to the end stage of the procedure, but was very effective. In a modern operative setting and with the necessary surgical experience recurrent epidermoid cysts may be removed with excellent clinical results. The combined use of microscope and endoscope offers relevant advantages in demanding anatomic situations. © Georg Thieme Verlag KG Stuttgart · New York.

Endoscopic Radiofrequency Ablation-Assisted Resection of Juvenile Nasopharyngeal Angiofibroma: Comparison with Traditional Endoscopic Technique.

Science.gov (United States)

McLaughlin, Eamon J; Cunningham, Michael J; Kazahaya, Ken; Hsing, Julianna; Kawai, Kosuke; Adil, Eelam A

2016-06-01

To evaluate the feasibility of radiofrequency surgical instrumentation for endoscopic resection of juvenile nasopharyngeal angiofibroma (JNA) and to test the hypothesis that endoscopic radiofrequency ablation-assisted (RFA) resection will have superior intraoperative and/or postoperative outcomes as compared with traditional endoscopic (TE) resection techniques. Case series with chart review. Two tertiary care pediatric hospitals. Twenty-nine pediatric patients who underwent endoscopic transnasal resection of JNA from January 2000 to December 2014. Twenty-nine patients underwent RFA (n = 13) or TE (n = 16) JNA resection over the 15-year study period. Mean patient age was not statistically different between the 2 groups (P = .41); neither was their University of Pittsburgh Medical Center classification stage (P = .79). All patients underwent preoperative embolization. Mean operative times were not statistically different (P = .29). Mean intraoperative blood loss and the need for a transfusion were also not statistically different (P = .27 and .47, respectively). Length of hospital stay was not statistically different (P = .46). Recurrence rates did not differ between groups (P = .99) over a mean follow-up period of 2.3 years. There were no significant differences between RFA and TE resection in intraoperative or postoperative outcome parameters. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Non-destructive tests of capsules for JMTR irradiation examination

International Nuclear Information System (INIS)

Tanaka, Hidetaka; Nagao, Yoshiharu; Sato, Masashi; Osawa, Kenji

2007-03-01

Irradiation examination are increasing in advanced irradiation research for accurate prediction control and evaluation of irradiation parameter such as neutron fluence, etc. by using JMTR. Irradiation capsule internals are therefore structurally complicated recently. This report described the procedure of non destructive tests such as radiographic test, penetrant test, ultrasonic test, etc. for inspection of irradiation capsules in JMTR, and the result of Test-case of confirmation procedure for internal parts of irradiation capsules. (author)

Regional Variation Is Present in Elbow Capsules after Injury

OpenAIRE

Germscheid, Niccole M.; Hildebrand, Kevin A.

2006-01-01

Myofibroblast numbers and α-smooth muscle actin expression are increased in anterior joint capsules of patients with posttraumatic elbow contractures. The purpose of our study was to determine whether these changes occur regionally or throughout the entire joint capsule. We hypothesized that the α-smooth muscle actin mRNA expression and the myofibroblast numbers in posterior joint capsules would be elevated in elbows obtained from patients with posttraumatic joint contractures compared with j...

Taking NOTES: translumenal flexible endoscopy and endoscopic surgery.

Science.gov (United States)

Willingham, Field F; Brugge, William R

2007-09-01

To review the current state of natural orifice surgery and examine the concerns, challenges, and opportunities presented by translumenal research. Translumenal endoscopic procedures have been the focus of extensive research. Researchers have reported natural orifice translumenal endoscopic surgery in a swine model in several areas involving the abdominal cavity. Diagnostic procedures have included endoscopic peritoneoscopy, liver biopsy, lymphadenectomy, and abdominal exploration. Several gynecologic procedures including tubal ligation, oophorectomy, and partial hysterectomy have been demonstrated using current commercial endoscopes. Gastrointestinal surgical procedures, including gastrojejunostomy, cholecystectomy, splenectomy, and distal pancreatectomy have been performed successfully via transgastric and/or transcolonic approaches. There have been no studies of natural orifice translumenal endoscopic surgery procedures published in humans. While fundamental questions about the emerging technology have not been scrutinized, limitations of the large animal model will pose a challenge to the development of large randomized trials. While natural orifice translumenal endoscopic surgery may represent a paradigm shift and may offer significant benefits to patients, rigorous testing of the techniques is lacking and current data have been drawn from case series.

Mini-open spinal column shortening for the treatment of adult tethered cord syndrome.

Science.gov (United States)

Safaee, Michael M; Winkler, Ethan A; Chou, Dean

2017-10-01

Tethered cord syndrome (TCS) is a challenging entity characterized by adhesions at the caudal spinal cord that prevent upward movement during growth and result in stretching of the cord with a concomitant constellation of neurologic symptoms. Although growth in height stops in adulthood, some patients still develop progressive symptoms; many underwent detethering as a child or adolescent, resulting in significant scar tissue and re-tethering. Recent strategies have focused on spinal column shortening to reduce tension on the spinal cord without exposing the previous de-tethering site. Mini-open and minimally invasive approaches avoid the large dissection and exposure associated with traditional approaches and are associated with reduced blood loss, shorter hospital stay, and similar outcomes when compared to conventional open approaches. We describe a technique for mini-open spinal column shortening. Using intraoperative navigation pedicle screws were placed at T10, T11, L1, and L2. A mini-open 3-column "egg shell" decancellation osteotomy of T12 was performed through a transpedicular approach with preservation of the superior and inferior endplates. This procedure was performed on a 28year old male with recurrent TCS and neurogenic bladder. Postoperative imaging showed a reduction in spinal column length of 1.5cm and evidence of decreased tension on the spinal cord. At last follow-up he was recovering well with improved urinary function. Spinal column shortening for adult TCS can be safely achieved through a mini-open approach. Future studies should compare the efficacy of this technique to both traditional de-tethering and open spinal column shortening. Copyright © 2017 Elsevier Ltd. All rights reserved.

SATCAP-C : a program for thermal hydraulic design of pressurized water injection type capsule

International Nuclear Information System (INIS)

Harayama, Yasuo; Someya, Hiroyuki; Asoh, Tomokazu; Niimi, Motoji

1992-10-01

There are capsules called 'Pressure Water Injection Type Capsule' as a kind of irradiation devices at the Japan Materials Testing Reactor (JMTR). A type of the capsules is a 'Boiling Water Capsule' (usually named BOCA). The other type is a 'Saturated Temperature Capsule' (named SATCAP). When the water is kept at a constant pressure, the water temperature does not become higher than the saturated temperature so far as the water does not fully change to steam. These type capsules are designed on the basis of the conception of applying the water characteristic to the control of irradiation temperature of specimens in the capsules. In designing of the capsules in which the pressurized water is injected, thermal performances have to be understood as exactly as possible. It is not easy however to predict thermal performances such as axially temperature distribution of water injected in the capsule, because there are heat-sinks at both side of inner and outer of capsule casing as the result that the water is fluid. Then, a program (named SATCAP-C) for the BOCA and SATCAP was compiled to grasp the thermal performances in the capsules and has been used the design of the capsules and analysis of the data obtained from some actual irradiation capsules. It was confirmed that the program was effective in thermal analysis for the capsules. The analysis found out the values for heat transfer coefficients at various surfaces of capsule components and some thermal characteristics of capsules. (author)

Endoscopic approach to the infratemporal fossa

Directory of Open Access Journals (Sweden)

Ahmed Youssef

2014-06-01

Conclusions: Endoscopic endonasal transpterygoid approach is considered one of the most useful surgical solutions to manage selected tumors that involve the infratemporal fossa. A good understanding of the endoscopic anatomy of infratemporal fossa allows safe and complete resection of lesions arising or extending to infratemporal fossa.

Simulations of indirectly driven gas-filled capsules at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Weber, S. V.; Casey, D. T.; Eder, D. C.; Pino, J. E.; Smalyuk, V. A.; Remington, B. A.; Rowley, D. P.; Yeamans, C. B.; Tipton, R. E.; Barrios, M.; Benedetti, R.; Berzak Hopkins, L.; Bleuel, D. L.; Bond, E. J.; Bradley, D. K.; Caggiano, J. A.; Callahan, D. A.; Cerjan, C. J.; Clark, D. S.; Divol, L. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2014-11-15

Gas-filled capsules imploded with indirect drive on the National Ignition Facility have been employed as symmetry surrogates for cryogenic-layered ignition capsules and to explore interfacial mix. Plastic capsules containing deuterated layers and filled with tritium gas provide a direct measure of mix of ablator into the gas fuel. Other plastic capsules have employed DT or D{sup 3}He gas fill. We present the results of two-dimensional simulations of gas-filled capsule implosions with known degradation sources represented as in modeling of inertial confinement fusion ignition designs; these are time-dependent drive asymmetry, the capsule support tent, roughness at material interfaces, and prescribed gas-ablator interface mix. Unlike the case of cryogenic-layered implosions, many observables of gas-filled implosions are in reasonable agreement with predictions of these simulations. Yields of TT and DT neutrons as well as other x-ray and nuclear diagnostics are matched for CD-layered implosions. Yields of DT-filled capsules are over-predicted by factors of 1.4–2, while D{sup 3}He capsule yields are matched, as well as other metrics for both capsule types.

[Endoscopic ultrasound guided rendezvous for biliary drainage].

Science.gov (United States)

Knudsen, Marie Høxbro; Vilmann, Peter; Hassan, Hazem; Karstensen, John Gésdal

2015-04-27

Endoscopic retrograde cholangiography (ERCP) is currently standard treatment for biliary drainage. Endoscopic ultrasound guided rendezvous (EUS-RV) is a novel method to overcome an unsuccessful biliary drainage procedure. Under endoscopic ultrasound guidance a guidewire is passed via a needle from the stomach or duodenum to the common bile duct and from there on to the duodenum enabling ERCP. With a relatively high rate of success EUS-RV should be considered as an alternative to biliary drainage and surgical intervention.

The first capsule implosion experiments on Orion

International Nuclear Information System (INIS)

Garbett, W J; Horsfield, C J; Gales, S G; Leatherland, A E; Rubery, M S; Coltman, J E; Meadowcroft, A E; Rice, S J; Simons, A J; Woolhead, V E

2016-01-01

Direct drive capsule implosions are being developed on the Orion laser at AWE as a platform for ICF and HED physics experiments. The Orion facility combines both long pulse and short-pulse beams, making it well suited for studying the physics of alternative ignition approaches. Orion implosions also provide the opportunity to study aspects of polar direct drive. Limitations on drive symmetry from the relatively small number of laser beams makes predictive modelling of the implosions challenging, resulting in some uncertainty in the expected capsule performance. Initial experiments have been fielded to evaluate baseline capsule performance and inform future design optimization. Highly promising DD fusion neutron yields in excess of 10 9 have been recorded. Results from the experiments are presented alongside radiation-hydrocode modelling. (paper)

Elimination of high titre HIV from fibreoptic endoscopes.

Science.gov (United States)

Hanson, P J; Gor, D; Jeffries, D J; Collins, J V

1990-06-01

Concern about contamination of fibreoptic endoscopes with human immunodeficiency virus (HIV) has generated a variety of disruptive and possibly unnecessary infection control practices in endoscopy units. Current recommendations on the cleaning and disinfection of endoscopes have been formulated without applied experimental evidence of the effective removal of HIV from endoscopes. To study the kinetics of elimination of HIV from endoscope surfaces, we artificially contaminated the suction-biopsy channels of five Olympus GIF XQ20 endoscopes with high titre HIV in serum. The air and water channels of two instruments were similarly contaminated. Contamination was measured by irrigating channels with viral culture medium and collecting 3 ml at the distal end for antigen immunoassay. Endoscopes were then cleaned manually in neutral detergent according to the manufacturer's recommendations and disinfected in 2% alkaline glutaraldehyde (Cidex, Surgikos) for two, four, and ten minutes. Contamination with HIV antigens was measured before and after cleaning and after each period of disinfection. Initial contamination comprised 4.8 x 10(4) to 3.5 x 10(6) pg HIV antigen/ml. Cleaning in detergent achieved a reduction to 165 pg/ml (99.93%) on one endoscope and to undetectable levels (100%) on four. After two minutes in alkaline glutaraldehyde all samples were negative and remained negative after the longer disinfection times. Air and water channels, where contaminated, were tested after 10 minutes' disinfection and were negative. These findings underline the importance of cleaning in removing HIV from endoscope and indicate that the use of dedicated equipment and long disinfection times are unnecessary.

Residual mercury content and leaching of mercury and silver from used amalgam capsules.

Science.gov (United States)

Stone, M E; Pederson, E D; Cohen, M E; Ragain, J C; Karaway, R S; Auxer, R A; Saluta, A R

2002-06-01

The objective of this investigation was to carry out residual mercury (Hg) determinations and toxicity characteristic leaching procedure (TCLP) analysis of used amalgam capsules. For residual Hg analysis, 25 capsules (20 capsules for one brand) from each of 10 different brands of amalgam were analyzed. Total residual Hg levels per capsule were determined using United States Environmental Protection Agency (USEPA) Method 7471. For TCLP analysis, 25 amalgam capsules for each of 10 brands were extracted using a modification of USEPA Method 1311. Hg analysis of the TCLP extracts was done with USEPA Method 7470A. Analysis of silver (Ag) concentrations in the TCLP extract was done with USEPA Method 6010B. Analysis of the residual Hg data resulted in the segregation of brands into three groups: Dispersalloy capsules, Group A, retained the most Hg (1.225 mg/capsule). These capsules were the only ones to include a pestle. Group B capsules, Valliant PhD, Optaloy II, Megalloy and Valliant Snap Set, retained the next highest amount of Hg (0.534-0.770 mg/capsule), and were characterized by a groove in the inside of the capsule. Group C, Tytin regular set double-spill, Tytin FC, Contour, Sybraloy regular set, and Tytin regular set single-spill retained the least amount of Hg (0.125-0.266 mg/capsule). TCLP analysis of the triturated capsules showed Sybraloy and Contour leached Hg at greater than the 0.2 mg/l Resource Conservation and Recovery Act (RCRA) limit. This study demonstrated that residual mercury may be related to capsule design features and that TCLP extracts from these capsules could, in some brands, exceed RCRA Hg limits, making their disposal problematic. At current RCRA limits, the leaching of Ag is not a problem.

[Exploring the clinical characters of Shugan Jieyu capsule through text mining].

Science.gov (United States)

Pu, Zheng-Ping; Xia, Jiang-Ming; Xie, Wei; He, Jin-Cai

2017-09-01

The study was main to explore the clinical characters of Shugan Jieyu capsule through text mining. The data sets of Shugan Jieyu capsule were downloaded from CMCC database by the method of literature retrieved from May 2009 to Jan 2016. Rules of Chinese medical patterns, diseases, symptoms and combination treatment were mined out by data slicing algorithm, and they were demonstrated in frequency tables and two dimension based network. Then totally 190 literature were recruited. The outcomess suggested that SC was most frequently correlated with liver Qi stagnation. Primary depression, depression due to brain disease, concomitant depression followed by physical diseases, concomitant depression followed by schizophrenia and functional dyspepsia were main diseases treated by Shugan Jieyu capsule. Symptoms like low mood, psychic anxiety, somatic anxiety and dysfunction of automatic nerve were mainy relieved bv Shugan Jieyu capsule.For combination treatment. Shugan Jieyu capsule was most commonly used with paroxetine, sertraline and fluoxetine. The research suggested that syndrome types and mining results of Shugan Jieyu capsule were almost the same as its instructions. Syndrome of malnutrition of heart spirit was the potential Chinese medical pattern of Shugan Jieyu capsule. Primary comorbid anxiety and depression, concomitant comorbid anxiety and depression followed by physical diseases, and postpartum depression were potential diseases treated by Shugan Jieyu capsule.For combination treatment, Shugan Jieyu capsule was most commonly used with paroxetine, sertraline and fluoxetine. Copyright© by the Chinese Pharmaceutical Association.

Significance of endoscopic screening and endoscopic resection for esophageal cancer in patients with hypopharyngeal cancer

International Nuclear Information System (INIS)

Morimoto, Masahiro; Nishiyama, Kinji; Nakamura, Satoaki

2010-01-01

The efficacy of endoscopic screening for esophageal cancer in patients with hypopharyngeal cancer remains controversial and its impact on prognosis has not been adequately discussed. We studied the use of endoscopic screening to detect esophageal cancer in hypopharyngeal cancer patients by analyzing the incidence, stage and prognosis. We included 64 patients with hypopharyngeal cancer who received radical radiotherapy at our institute. Chromoendoscopic esophageal examinations with Lugol dye solution were routinely performed at and after treatment for hypopharyngeal cancer. Twenty-eight esophageal cancers were detected in 28 (41%) patients (18 synchronous and 10 metachronous cancers). Of the 28 cancers, 23 were stage 0 or I cancer and 15 of these were treated with endoscopic resection. Local control was achieved in all of these 23 stage 0 or I cancers. The 5-year overall survival rates with esophageal cancer were 83% in stage 0, 47% in stage I and 0% in stage IIA-IVB. This study showed a strikingly high incidence of esophageal cancer in hypopharyngeal cancer patients. We suppose that the combination of early detection by chromoendoscopic examination and endoscopic resection for associated esophageal cancer in hypopharyngeal cancer patients improve prognosis and maintain quality of life. (author)

Tuning peptide self-assembly by an in-tether chiral center

Science.gov (United States)

Hu, Kuan; Xiong, Wei; Li, Hu; Zhang, Pei-Yu; Yin, Feng; Zhang, Qianling; Jiang, Fan; Li, Zigang

2018-01-01

The self-assembly of peptides into ordered nanostructures is important for understanding both peptide molecular interactions and nanotechnological applications. However, because of the complexity and various self-assembling pathways of peptide molecules, design of self-assembling helical peptides with high controllability and tunability is challenging. We report a new self-assembling mode that uses in-tether chiral center-induced helical peptides as a platform for tunable peptide self-assembly with good controllability. It was found that self-assembling behavior was governed by in-tether substitutional groups, where chirality determined the formation of helical structures and aromaticity provided the driving force for self-assembly. Both factors were essential for peptide self-assembly to occur. Experiments and theoretical calculations indicate long-range crystal-like packing in the self-assembly, which was stabilized by a synergy of interpeptide π-π and π-sulfur interactions and hydrogen bond networks. In addition, the self-assembled peptide nanomaterials were demonstrated to be promising candidate materials for applications in biocompatible electrochemical supercapacitors.

Limits of the endoscopic transnasal transtubercular approach.

Science.gov (United States)

Gellner, Verena; Tomazic, Peter V

2018-06-01

The endoscopic transnasal trans-sphenoidal transtubercular approach has become a standard alternative approach to neurosurgical transcranial routes for lesions of the anterior skull base in particular pathologies of the anterior tubercle, sphenoid plane, and midline lesions up to the interpeduncular cistern. For both the endoscopic and the transcranial approach indications must strictly be evaluated and tailored to the patients' morphology and condition. The purpose of this review was to evaluate the evidence in literature of the limitations of the endoscopic transtubercular approach. A PubMed/Medline search was conducted in January 2018 entering following keywords. Upon initial screening 7 papers were included in this review. There are several other papers describing the endoscopic transtubercular approach (ETTA). We tried to list the limitation factors according to the actual existing literature as cited. The main limiting factors are laterally extending lesions in relation to the optic canal and vascular encasement and/or unfavorable tumor tissue consistency. The ETTA is considered as a high level transnasal endoscopic extended skull base approach and requires excellent training, skills and experience.

The double capsules in macro-textured breast implants.

Science.gov (United States)

Giot, Jean-Philippe; Paek, Laurence S; Nizard, Nathanael; El-Diwany, Mostafa; Gaboury, Louis A; Nelea, Monica; Bou-Merhi, Joseph S; Harris, Patrick G; Danino, Michel A

2015-10-01

Breast implants are amongst the most widely used types of permanent implants in modern medicine and have both aesthetic and reconstructive applications with excellent biocompatibility. The double capsule is a complication associated with textured prostheses that leads to implant displacement; however, its etiology has yet to be elucidated. In this study, 10 double capsules were sampled from breast expander implants for in-depth analysis; histologically, the inner capsular layer demonstrated highly organized collagen in sheets with delamination of fibers. At the prosthesis interface (PI) where the implant shell contacts the inner capsular layer, scanning electron microscopy (SEM) revealed a thin layer which mirrored the three-dimensional characteristics of the implant texture; the external surface of the inner capsular layer facing the intercapsular space (ICS) was flat. SEM examination of the inner capsule layer revealed both a large bacterial presence as well as biofilm deposition at the PI; a significantly lower quantity of bacteria and biofilm were found at the ICS interface. These findings suggest that the double capsule phenomenon's etiopathogenesis is of mechanical origin. Delamination of the periprosthetic capsule leads to the creation of the ICS; the maintained separation of the 2 layers subsequently alters the biostability of the macro-textured breast implant. Copyright © 2015 Elsevier Ltd. All rights reserved.

Laparoscopic-endoscopic rendezvous versus preoperative endoscopic sphincterotomy in people undergoing laparoscopic cholecystectomy for stones in the gallbladder and bile duct.

Science.gov (United States)

Vettoretto, Nereo; Arezzo, Alberto; Famiglietti, Federico; Cirocchi, Roberto; Moja, Lorenzo; Morino, Mario

2018-04-11

The management of gallbladder stones (lithiasis) concomitant with bile duct stones is controversial. The more frequent approach is a two-stage procedure, with endoscopic sphincterotomy and stone removal from the bile duct followed by laparoscopic cholecystectomy. The laparoscopic-endoscopic rendezvous combines the two techniques in a single-stage operation. To compare the benefits and harms of endoscopic sphincterotomy and stone removal followed by laparoscopic cholecystectomy (the single-stage rendezvous technique) versus preoperative endoscopic sphincterotomy followed by laparoscopic cholecystectomy (two stages) in people with gallbladder and common bile duct stones. We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, Science Citation Index Expanded Web of Science, and two trials registers (February 2017). We included randomised clinical trials that enrolled people with concomitant gallbladder and common bile duct stones, regardless of clinical status or diagnostic work-up, and compared laparoscopic-endoscopic rendezvous versus preoperative endoscopic sphincterotomy procedures in people undergoing laparoscopic cholecystectomy. We excluded other endoscopic or surgical methods of intraoperative clearance of the bile duct, e.g. non-aided intraoperative endoscopic retrograde cholangiopancreatography or laparoscopic choledocholithotomy (surgical incision of the common bile duct for removal of bile duct stones). We used standard methodological procedures recommended by Cochrane. We included five randomised clinical trials with 517 participants (257 underwent a laparoscopic-endoscopic rendezvous technique versus 260 underwent a sequential approach), which fulfilled our inclusion criteria and provided data for analysis. Trial participants were scheduled for laparoscopic cholecystectomy because of suspected cholecysto-choledocholithiasis. Male/female ratio was 0.7; age of men and women ranged from 21 years to 87

Versatile Loading of Diverse Cargo into Functional Polymer Capsules.

Science.gov (United States)

Richardson, Joseph J; Maina, James W; Ejima, Hirotaka; Hu, Ming; Guo, Junling; Choy, Mei Y; Gunawan, Sylvia T; Lybaert, Lien; Hagemeyer, Christoph E; De Geest, Bruno G; Caruso, Frank

2015-02-01

Polymer microcapsules are of particular interest for applications including self-healing coatings, catalysis, bioreactions, sensing, and drug delivery. The primary way that polymer capsules can exhibit functionality relevant to these diverse fields is through the incorporation of functional cargo in the capsule cavity or wall. Diverse functional and therapeutic cargo can be loaded into polymer capsules with ease using polymer-stabilized calcium carbonate (CaCO 3 ) particles. A variety of examples are demonstrated, including 15 types of cargo, yielding a toolbox with effectively 500+ variations. This process uses no harsh reagents and can take less than 30 min to prepare, load, coat, and form the hollow capsules. For these reasons, it is expected that the technique will play a crucial role across scientific studies in numerous fields.

Endoscopic inspection of steam turbines

International Nuclear Information System (INIS)

Maliniemi, H.; Muukka, E.

1990-01-01

For over ten years, Imatran Voima Oy (IVO) has developed, complementary inspection methods for steam turbine condition monitoring, which can be applied both during operation and shutdown. One important method used periodically during outages is endoscopic inspection. The inspection is based on the method where the internal parts of the turbine is inspected through access borings with endoscope and where the magnified figures of the internal parts is seen on video screen. To improve inspection assurance, an image-processing based pattern recognition method for cracks has been developed for the endoscopic inspection of turbine blades. It is based on the deduction conditions derived from the crack shape. The computer gives an alarm of a crack detection and prints a simulated image of the crack, which is then checked manually

Endoscopic Palliation for Pancreatic Cancer

Directory of Open Access Journals (Sweden)

Mihir Bakhru

2011-04-01

Full Text Available Pancreatic cancer is devastating due to its poor prognosis. Patients require a multidisciplinary approach to guide available options, mostly palliative because of advanced disease at presentation. Palliation including relief of biliary obstruction, gastric outlet obstruction, and cancer-related pain has become the focus in patients whose cancer is determined to be unresectable. Endoscopic stenting for biliary obstruction is an option for drainage to avoid the complications including jaundice, pruritus, infection, liver dysfunction and eventually failure. Enteral stents can relieve gastric obstruction and allow patients to resume oral intake. Pain is difficult to treat in cancer patients and endoscopic procedures such as pancreatic stenting and celiac plexus neurolysis can provide relief. The objective of endoscopic palliation is to primarily address symptoms as well improve quality of life.

Cost-effectiveness of endoscopic ultrasonography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography in patients suspected of pancreaticobiliary disease

DEFF Research Database (Denmark)

Ainsworth, A P; Rafaelsen, S R; Wamberg, P A

2004-01-01

BACKGROUND: It is not known whether initial endoscopic ultrasonography (EUS) or magnetic resonance cholangiopancreatography (MRCP) is more cost effective than endoscopic retrograde cholangiopancreatography (ERCP). METHODS: A cost-effectiveness analysis of EUS, MRCP and ERCP was performed on 163...

Method of forming capsules containing a precise amount of material

Science.gov (United States)

Grossman, M.W.; George, W.A.; Maya, J.

1986-06-24

A method of forming a sealed capsule containing a submilligram quantity of mercury or the like, the capsule being constructed from a hollow glass tube, by placing a globule or droplet of the mercury in the tube. The tube is then evacuated and sealed and is subsequently heated so as to vaporize the mercury and fill the tube therewith. The tube is then separated into separate sealed capsules by heating spaced locations along the tube with a coiled heating wire means to cause collapse spaced locations there along and thus enable separation of the tube into said capsules. 7 figs.

Iodometric determination of ampicillin in proprietary capsules | Ejele ...

African Journals Online (AJOL)

The concentration of ampicillin in ampicillin capsule preparations purchased in Owerri main market, Imo State of Nigeria, was determined using the iodometric titration method. The results showed that the ampicillin concentrations in the capsules contained between 250 and 260 mg/cap of ampicillin trihydrate. Statistical ...

Diamond surface functionalization with biomimicry – Amine surface tether and thiol moiety for electrochemical sensors

Energy Technology Data Exchange (ETDEWEB)

Sund, James B., E-mail: jim@jamessund.com [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Causey, Corey P. [Departments of Chemistry and Biochemistry, Duke University, Durham, NC (United States); Wolter, Scott D. [Department of Physics, Elon University, Elon, NC 27244 (United States); Parker, Charles B., E-mail: charles.parker@duke.edu [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Stoner, Brian R. [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Research Triangle Institute (RTI) International, Research Triangle Park, NC (United States); Toone, Eric J. [Departments of Chemistry and Biochemistry, Duke University, Durham, NC (United States); Glass, Jeffrey T. [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States)

2014-05-01

Highlights: • Diamond surfaces were functionalized with organic molecules using a novel approach. • Used biomimicry to select a molecule to bind NO, similar to the human body. • Molecular orbital theory predicted the molecule-analyte oxidation behavior. • A thiol moiety was attached to an amine surface tether on the diamond surface. • XPS analysis verified each surface functionalization step. - Abstract: The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen–oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis.

Diamond surface functionalization with biomimicry – Amine surface tether and thiol moiety for electrochemical sensors

International Nuclear Information System (INIS)

Sund, James B.; Causey, Corey P.; Wolter, Scott D.; Parker, Charles B.; Stoner, Brian R.; Toone, Eric J.; Glass, Jeffrey T.

2014-01-01

Highlights: • Diamond surfaces were functionalized with organic molecules using a novel approach. • Used biomimicry to select a molecule to bind NO, similar to the human body. • Molecular orbital theory predicted the molecule-analyte oxidation behavior. • A thiol moiety was attached to an amine surface tether on the diamond surface. • XPS analysis verified each surface functionalization step. - Abstract: The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen–oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis

Technical and economical assessment on tethered wind-energy systems (TWES)

Energy Technology Data Exchange (ETDEWEB)

Furuya, O.; Maekawa, S.

1982-06-01

The objective of the work reported was to establish the potential of tethered wind energy systems for energy conversion in the upper atmosphere. Of the concepts investigated, the Vertical Takeoff and Landing (VTOL) lift generation concept had the highest potential as compared to balloon, wind and hybrid concepts.

Endoscopic management of bile leaks after laparoscopic ...

African Journals Online (AJOL)

Endoscopic management of bile leaks after laparoscopic cholecystectomy. ... endoscopic management at a median of 12 days (range 2 - 104 days) after surgery. Presenting features included intra-abdominal collections with pain in 58 cases ...

Endoscopic Ultrasonography in the Diagnosis of Gastric Subepithelial Lesions

Directory of Open Access Journals (Sweden)

Eun Jeong Gong

2016-09-01

Full Text Available Subepithelial lesions occasionally found in the stomach of patients undergoing endoscopy may be either benign lesions or tumors with malignant potential. They may also appear due to extrinsic compression. Discrimination of gastric subepithelial lesions begins with meticulous endoscopic examination for size, shape, color, mobility, consistency, and appearance of the overlying mucosa. Accurate diagnosis can be achieved with endoscopic ultrasonography, which provides useful information on the exact size, layer-of-origin, and characteristic morphologic features to support a definitive diagnosis. Endoscopic ultrasonography also aids in the prediction of malignant potential, especially in gastrointestinal stromal tumors. Features of subepithelial lesions identified on endoscopic ultrasonography can be used to determine whether further diagnostic procedures such as endoscopic resection, fine needle aspiration, or core biopsy are required. Endoscopic ultrasonography is a valuable tool for diagnosis and clinical decision making during follow-up of gastric subepithelial lesions.

Endoscopic Management of Tumor Bleeding from Inoperable Gastric Cancer

Science.gov (United States)

Kim, Young-Il

2015-01-01

Tumor bleeding is not a rare complication in patients with inoperable gastric cancer. Endoscopy has important roles in the diagnosis and primary treatment of tumor bleeding, similar to its roles in other non-variceal upper gastrointestinal bleeding cases. Although limited studies have been performed, endoscopic therapy has been highly successful in achieving initial hemostasis. One or a combination of endoscopic therapy modalities, such as injection therapy, mechanical therapy, or ablative therapy, can be used for hemostasis in patients with endoscopic stigmata of recent hemorrhage. However, rebleeding after successful hemostasis with endoscopic therapy frequently occurs. Endoscopic therapy may be a treatment option for successfully controlling this rebleeding. Transarterial embolization or palliative surgery should be considered when endoscopic therapy fails. For primary and secondary prevention of tumor bleeding, proton pump inhibitors can be prescribed, although their effectiveness to prevent bleeding remains to be investigated. PMID:25844339

Bowman Capsulitis Predicts Poor Kidney Allograft Outcome in T Cell-Mediated Rejection.

Science.gov (United States)

Gallan, Alexander J; Chon, W James; Josephson, Michelle A; Cunningham, Patrick N; Henriksen, Kammi J; Chang, Anthony

2018-02-28

Acute T cell-mediated rejection (TCMR) is an important cause of renal allograft loss. The Banff classification for tubulointerstitial (type I) rejection is based on the extent of both interstitial inflammation and tubulitis. Lymphocytes may also be present between parietal epithelial cells and Bowman capsules in this setting, which we have termed "capsulitis." We conducted this study to determine the clinical significance of capsulitis. We identified 42 patients from the pathology archives at the University of Chicago with isolated Banff type I TCMR from 2010-2015. Patient demographic data, Banff classification, and graft outcome measurements were compared between capsulitis and non-capsulitis groups using Mann-Whitney U test. Capsulitis was present in 26 (62%), and was more frequently seen in Banff IB than IA TCMR (88% vs 44%, P=.01). Patients with capsulitis had a higher serum creatinine at biopsy (4.6 vs 2.9mg/dL, P=.04) and were more likely to progress to dialysis (42% vs 13%, P=.06) with fewer recovering their baseline serum creatinine (12% vs 38%, P=.08). Patients with both Banff IA TCMR and capsulitis have clinical outcomes similar or possibly worse than Banff IB TCMR compared to those with Banff IA and an absence of capsulitis. Capsulitis is an important pathologic parameter in the evaluation of kidney transplant biopsies with potential diagnostic, prognostic, and therapeutic implications in the setting of TCMR. Copyright © 2018. Published by Elsevier Inc.

Diamond surface functionalization with biomimicry - Amine surface tether and thiol moiety for electrochemical sensors

Science.gov (United States)

Sund, James B.; Causey, Corey P.; Wolter, Scott D.; Parker, Charles B.; Stoner, Brian R.; Toone, Eric J.; Glass, Jeffrey T.

2014-05-01

The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen-oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis.

The effect of glicerol and sorbitol plasticizers toward disintegration time of phyto-capsules

Science.gov (United States)

Pudjiastuti, Pratiwi; Hendradi, Esti; Wafiroh, Siti; Harsini, Muji; Darmokoesoemo, Handoko

2016-03-01

The aim of research is determining the effect of glycerol and sorbitol toward the disintegration time of phyto-capsules, originated capsules from plant polysaccharides. Phyto-capsules were made from polysaccharides and 0.5% (v/v) of glycerol and sorbitol of each. The seven capsules of each were determined the disintegration time using Erweka disintegrator. The mean of disintegration time of phyto-capsules without plasticizers, with glycerol and sorbitol were 25'30"; 45'15" and 35'30" respectively. The color and colorless gelatin capsules showed the mean of disintegration time 7'30" and 2'35" respectively.

Alginate/sodium caseinate aqueous-core capsules: a pH-responsive matrix.

Science.gov (United States)

Ben Messaoud, Ghazi; Sánchez-González, Laura; Jacquot, Adrien; Probst, Laurent; Desobry, Stéphane

2015-02-15

Alginate capsules have several applications. Their functionality depends considerably on their permeability, chemical and mechanical stability. Consequently, the creation of composite system by addition of further components is expected to control mechanical and release properties of alginate capsules. Alginate and alginate-sodium caseinate composite liquid-core capsules were prepared by a simple extrusion. The influence of the preparation pH and sodium caseinate concentration on capsules physico-chemical properties was investigated. Results showed that sodium caseinate influenced significantly capsules properties. As regards to the membrane mechanical stability, composite capsules prepared at pH below the isoelectric point of sodium caseinate exhibited the highest surface Young's modulus, increasing with protein content, explained by potential electrostatic interactions between sodium caseinate amino-groups and alginate carboxylic group. The kinetic of cochineal red A release changed significantly for composite capsules and showed a pH-responsive release. Sodium caseinate-dye mixture studied by absorbance and fluorescence spectroscopy confirmed complex formation at pH 2 by electrostatic interactions between sodium caseinate tryptophan residues and cochineal red sulfonate-groups. Consequently, the release mechanism was explained by membrane adsorption process. This global approach is useful to control release mechanism from macro and micro-capsules by incorporating guest molecules which can interact with the entrapped molecule under specific conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

Unsedated peroral wireless pH capsule placement vs. standard pH testing: A randomized study and cost analysis

Directory of Open Access Journals (Sweden)

Andrews Christopher N

2012-05-01

Full Text Available Abstract Background Wireless capsule pH-metry (WC is better tolerated than standard nasal pH catheter (SC, but endoscopic placement is expensive. Aims: to confirm that non-endoscopic peroral manometric placement of WC is as effective and better tolerated than SC and to perform a cost analysis of the available esophageal pH-metry methods. Methods Randomized trial at 2 centers. Patients referred for esophageal pH testing were randomly assigned to WC with unsedated peroral placement or SC after esophageal manometry (ESM. Primary outcome was overall discomfort with pH-metry. Costs of 3 different pH-metry strategies were analyzed: 1 ESM + SC, 2 ESM + WC and 3 endoscopically placed WC (EGD + WC using publicly funded health care system perspective. Results 86 patients (mean age 51 ± 2 years, 71% female were enrolled. Overall discomfort score was less in WC than in SC patients (26 ± 4 mm vs 39 ± 4 mm VAS, respectively, p = 0.012 but there were no significant group differences in throat, chest, or overall discomfort during placement. Overall failure rate was 7% in the SC group vs 12% in the WC group (p = 0.71. Per patient costs ($Canadian were $1475 for EGD + WC, $1014 for ESM + WC, and $906 for ESM + SC. Decreasing the failure rate of ESM + WC from 12% to 5% decreased the cost of ESM + WC to $991. The ESM + SC and ESM + WC strategies became equivalent when the cost of the WC device was dropped from $292 to $193. Conclusions Unsedated peroral WC insertion is better tolerated than SC pH-metry both overall and during placement. Although WC is more costly, the extra expense is partially offset when the higher patient and caregiver time costs of SC are considered. Trial registration Clinicaltrials.gov Identifier NCT01364610

Antibiotic prophylaxis for patients undergoing elective endoscopic ...

African Journals Online (AJOL)

Antibiotic prophylaxis for patients undergoing elective endoscopic retrograde cholangiopancreatography. M Brand, D Bisoz. Abstract. Background. Antibiotic prophylaxis for endoscopic retrograde cholangiopancreatography (ERCP) is controversial. We set out to assess the current antibiotic prescribing practice among ...

Analysis of lomustine drug content in FDA-approved and compounded lomustine capsules.

Science.gov (United States)

KuKanich, Butch; Warner, Matt; Hahn, Kevin

2017-02-01

OBJECTIVE To determine the lomustine content (potency) in compounded and FDA-approved lomustine capsules. DESIGN Evaluation study. SAMPLE 2 formulations of lomustine capsules (low dose [7 to 11 mg] and high dose [40 to 48 mg]; 5 capsules/dose/source) from 3 compounders and from 1 manufacturer of FDA-approved capsules. PROCEDURES Lomustine content was measured by use of a validated high-pressure liquid chromatography method. An a priori acceptable range of 90% to 110% of the stated lomustine content was selected on the basis of US Pharmacopeia guidelines. RESULTS The measured amount of lomustine in all compounded capsules was less than the stated content (range, 59% to 95%) and was frequently outside the acceptable range (failure rate, 2/5 to 5/5). Coefficients of variation for lomustine content ranged from 4.1% to 16.7% for compounded low-dose capsules and from 1.1% to 10.8% for compounded high-dose capsules. The measured amount of lomustine in all FDA-approved capsules was slightly above the stated content (range, 104% to 110%) and consistently within the acceptable range. Coefficients of variation for lomustine content were 0.5% for low-dose and 2.3% for high-dose FDA-approved capsules. CONCLUSIONS AND CLINICAL RELEVANCE Compounded lomustine frequently did not contain the stated content of active drug and had a wider range of lomustine content variability than did the FDA-approved product. The sample size was small, and larger studies are needed to confirm these findings; however, we recommend that compounded veterinary formulations of lomustine not be used when appropriate doses can be achieved with FDA-approved capsules or combinations of FDA-approved capsules.

Magnesium Ion Acts as a Signal for Capsule Induction in Cryptococcus neoformans.

Science.gov (United States)

Rathore, Sudarshan S; Raman, Thiagarajan; Ramakrishnan, Jayapradha

2016-01-01

Cryptococcal meningitis caused by Cryptococcus neoformans, is a common opportunistic neural infection in immunocompromised individuals. Cryptococcus meningitis is associated with fungal burden with larger capsule size in cerebrospinal fluid (CSF). To understand the role of CSF constituents in capsule enlargement, we have evaluated the effect of artificial CSF on capsule induction in comparison with various other capsule inducing media. Two different strains of C. neoformans, an environmental and a clinical isolates were used in the present study. While comparing the various capsule inducing media for the two different strains of C. neoformans, it was observed that the capsule growth was significantly increased when grown in artificial CSF at pH 5.5, temperature 34°C for ATCC C. neoformans and 37°C for Clinical C. neoformans and with an incubation period of 72 h. In addition, artificial CSF supports biofilm formation in C. neoformans. While investigating the individual components of artificial CSF, we found that Mg(2+) ions influence the capsule growth in both environmental and clinical strains of C. neoformans. To confirm our results we studied the expression of four major CAP genes namely, CAP10, CAP59, CAP60, and CAP64 in various capsule inducing media and in different concentrations of Mg(2+) and Ca(2+). Our results on gene expression suggest that, Mg(2+) does have an effect on CAP gene expression, which are important for capsule biosynthesis and virulence. Our findings on the role of Mg(2+) ion as a signal for capsule induction will promote a way to elucidate the control mechanisms for capsule biosynthesis in C. neoformans.

Irradiation capsules VISA-2a-f, chapter VI

International Nuclear Information System (INIS)

Pavicevic, M.

1962-01-01

Irradiation capsules VISA-2a, b,c,d, and e were constructed in Saclay according to the drawings from Vinca and according to the demand of the experimentators. This chapter VI includes documentation for each type of capsule, review about each experiment within the VISA-2 project, the objective and purpose of the experiment as well as experimental device. Irradiation capsule VISA-2f was placed in the RA reactor core in September 1962. It was completely manufactured in Vinca including sample holders and leak tight shells. It will remain in the reactor core for about month in order to obtain the integral fast neutron flux [sr

Some views on mechanical safety of capsules for radioactive waste

International Nuclear Information System (INIS)

Nilsson, F.

1978-02-01

Three different concepts for encapsulation of used nuclear fuel are discussed with respect to their mechanical safety. In the first concept the burnt out fuel elements are encapsulated into a copper capsule. The material properties of copper are discussed especially with reference to toughness and creep. A simple fracture mechanical analysis shows that the risk for direct fracture is negligible at the actual stress levels. The loads on the capsule are studied and are found to be normally less than 40 MPa (residual stresses). Transient loads that might arise in the handling of the capsule might however be dangerous to its integrity. The next concept is encapsulation of the fuel elements into a sintered aluminium oxide capsule. A fracture probability analysis based on Weibull's statistical fracture theory gives fracture probabilities that are acceptable. Extended studies of this concept, especially of the risk for delayed fracture, is recommended. The last concept is a Pb-Ti capsule for glassed refined fuel. An analysis of the relaxation of internal stresses is performed. The critical point of these capsules appears to be the welds on the titanium shell where the risk for a direct fracture is not neglibigle

Endoscopic Instruments and Electrosurgical Unit for Colonoscopic Polypectomy

OpenAIRE

Park, Hong Jun

2016-01-01

Colorectal polypectomy is an effective method for prevention of colorectal cancer. Many endoscopic instruments have been used for colorectal polypectomy, such as snares, forceps, endoscopic clips, a Coagrasper, retrieval net, injector, and electrosurgery generator unit (ESU). Understanding the characteristics of endoscopic instruments and their proper use according to morphology and size of the colorectal polyp will enable endoscopists to perform effective polypectomy. I reviewed the characte...

The Antiphagocytic Activity of SeM of Streptococcus equi Requires Capsule.

Science.gov (United States)

Timoney, John F; Suther, Pranav; Velineni, Sridhar; Artiushin, Sergey C

2014-01-01

Resistance to phagocytosis is a crucial virulence property of Streptococcus equi (Streptococcus equi subsp. equi; Se), the cause of equine strangles. The contribution and interdependence of capsule and SeM to killing in equine blood and neutrophils were investigated in naturally occurring strains of Se. Strains CF32, SF463 were capsule and SeM positive, strains Lex90, Lex93 were capsule negative and SeM positive and strains Se19, Se1-8 were capsule positive and SeM deficient. Phagocytosis and killing of Se19, Se1-8, Lex90 and Lex93 in equine blood and by neutrophils suspended in serum were significantly (P ≤ 0.02) greater compared to CF32 and SF463. The results indicate capsule and SeM are both required for resistance to phagocytosis and killing and that the anti-phagocytic property of SeM is greatly reduced in the absence of capsule.

Membrane support of accelerated fuel capsules for inertial fusion energy reactors

International Nuclear Information System (INIS)

Petzoldt, R.W.; Moir, R.W.

1993-01-01

The use of a thin membrane to suspend an (inertial fusion energy) fuel capsule in a holder for injection into a reactor chamber is investigated. Capsule displacement and membrane deformation angle are calculated for an axisymmetric geometry for a range of membrane strain and capsule size. This information is used to calculate maximum target accelerations. Membranes must be thin (perhaps of order one micron) to minimize their effect on capsule implosion symmetry. For example, a 5 μm thick cryogenic mylar membrane is calculated to allow 1,000 m/s 2 acceleration of a 3 mm radius, 100 mg capsule. Vibration analysis (for a single membrane support) shows that if membrane vibration is not deliberately minimized, allowed acceleration may be reduced by a factor of four. A two membrane alternative geometry would allow several times greater acceleration. Therefore, alternative membrane geometry's should be used to provide greater target acceleration potential and reduce capsule displacement within the holder (for a given membrane thickness)

Phase coupling of a circadian neuropeptide with rest/activity rhythms detected using a membrane-tethered spider toxin.

Directory of Open Access Journals (Sweden)

Ying Wu

2008-11-01

Full Text Available Drosophila clock neurons are self-sustaining cellular oscillators that rely on negative transcriptional feedback to keep circadian time. Proper regulation of organismal rhythms of physiology and behavior requires coordination of the oscillations of individual clock neurons within the circadian control network. Over the last decade, it has become clear that a key mechanism for intercellular communication in the circadian network is signaling between a subset of clock neurons that secrete the neuropeptide pigment dispersing factor (PDF and clock neurons that possess its G protein-coupled receptor (PDFR. Furthermore, the specific hypothesis has been proposed that PDF-secreting clock neurons entrain the phase of organismal rhythms, and the cellular oscillations of other clock neurons, via the temporal patterning of secreted PDF signals. In order to test this hypothesis, we have devised a novel technique for altering the phase relationship between circadian transcriptional feedback oscillation and PDF secretion by using an ion channel-directed spider toxin to modify voltage-gated Na(+ channel inactivation in vivo. This technique relies on the previously reported "tethered-toxin" technology for cell-autonomous modulation of ionic conductances via heterologous expression of subtype-specific peptide ion channel toxins as chimeric fusion proteins tethered to the plasma membrane with a glycosylphosphatidylinositol (GPI anchor. We demonstrate for the first time, to our knowledge, the utility of the tethered-toxin technology in a transgenic animal, validating four different tethered spider toxin ion channel modifiers for use in Drosophila. Focusing on one of these toxins, we show that GPI-tethered Australian funnel-web spider toxin delta-ACTX-Hv1a inhibits Drosophila para voltage-gated Na(+ channel inactivation when coexpressed in Xenopus oocytes. Transgenic expression of membrane-tethered delta-ACTX-Hv1a in vivo in the PDF-secreting subset of clock neurons

Effect of Heat Flux on the Specimen Temperature of an LBE Capsule

International Nuclear Information System (INIS)

Kang, Y. H.; Park, S. J.; Cho, M. S.; Choo, K. N.; Lee, Y. S.

2011-01-01

For application of high-temperature irradiation tests in the HANARO reactor for Gen IV reactor material development, a number of newly designed LBE capsules have been investigated at KAERI since 2008. Recent study on heat transfer experiment of an LBE capsule with a single heater has shown that the specimen temperature of the mock-up increased linearly with an increase of heat input. The work highlighted only the heat transfer capability of an LBE capsule with a single heater as a simulated specimen in a liquid metal medium. Hence, a new LBE capsule with multi specimen sets has been designed and fabricated for the heat transfer experiment of an LBE capsule of 11M-01K. In this paper, a series of thermal analyses and heat transfer experiments for a newly designed LBE capsule was implemented to study the effect of an increase in the value of heat input and its influence on temperature distribution in the capsule mock-up

Computer Programs for Calculating and Plotting the Stability Characteristics of a Balloon Tethered in a Wind

Science.gov (United States)

Bennett, R. M.; Bland, S. R.; Redd, L. T.

1973-01-01

Computer programs for calculating the stability characteristics of a balloon tethered in a steady wind are presented. Equilibrium conditions, characteristic roots, and modal ratios are calculated for a range of discrete values of velocity for a fixed tether-line length. Separate programs are used: (1) to calculate longitudinal stability characteristics, (2) to calculate lateral stability characteristics, (3) to plot the characteristic roots versus velocity, (4) to plot the characteristic roots in root-locus form, (5) to plot the longitudinal modes of motion, and (6) to plot the lateral modes for motion. The basic equations, program listings, and the input and output data for sample cases are presented, with a brief discussion of the overall operation and limitations. The programs are based on a linearized, stability-derivative type of analysis, including balloon aerodynamics, apparent mass, buoyancy effects, and static forces which result from the tether line.

Use of Tethered Enzymes as a Platform Technology for Rapid Analyte Detection.

Directory of Open Access Journals (Sweden)

Roy Cohen

Full Text Available Rapid diagnosis for time-sensitive illnesses such as stroke, cardiac arrest, and septic shock is essential for successful treatment. Much attention has therefore focused on new strategies for rapid and objective diagnosis, such as Point-of-Care Tests (PoCT for blood biomarkers. Here we use a biomimicry-based approach to demonstrate a new diagnostic platform, based on enzymes tethered to nanoparticles (NPs. As proof of principle, we use oriented immobilization of pyruvate kinase (PK and luciferase (Luc on silica NPs to achieve rapid and sensitive detection of neuron-specific enolase (NSE, a clinically relevant biomarker for multiple diseases ranging from acute brain injuries to lung cancer. We hypothesize that an approach capitalizing on the speed and catalytic nature of enzymatic reactions would enable fast and sensitive biomarker detection, suitable for PoCT devices.We performed in-vitro, animal model, and human subject studies. First, the efficiency of coupled enzyme activities when tethered to NPs versus when in solution was tested, demonstrating a highly sensitive and rapid detection of physiological and pathological concentrations of NSE. Next, in rat stroke models the enzyme-based assay was able in minutes to show a statistically significant increase in NSE levels in samples taken 1 hour before and 0, 1, 3 and 6 hours after occlusion of the distal middle cerebral artery. Finally, using the tethered enzyme assay for detection of NSE in samples from 20 geriatric human patients, we show that our data match well (r = 0.815 with the current gold standard for biomarker detection, ELISA-with a major difference being that we achieve detection in 10 minutes as opposed to the several hours required for traditional ELISA.Oriented enzyme immobilization conferred more efficient coupled activity, and thus higher assay sensitivity, than non-tethered enzymes. Together, our findings provide proof of concept for using oriented immobilization of active

Spinal column shortening for tethered cord syndrome associated with myelomeningocele, lumbosacral lipoma, and lipomyelomeningocele in children and young adults.

Science.gov (United States)

Aldave, Guillermo; Hansen, Daniel; Hwang, Steven W; Moreno, Amee; Briceño, Valentina; Jea, Andrew

2017-06-01

OBJECTIVE Tethered cord syndrome is the clinical manifestation of an abnormal stretch on the spinal cord, presumably causing mechanical injury, a compromised blood supply, and altered spinal cord metabolism. Tethered cord release is the standard treatment for tethered cord syndrome. However, direct untethering of the spinal cord carries potential risks, such as new neurological deficits from spinal cord injury, a CSF leak from opening the dura, and retethering of the spinal cord from normal scar formation after surgery. To avoid these risks, the authors applied spinal column shortening to children and transitional adults with primary and secondary tethered cord syndrome and report treatment outcomes. The authors' aim with this study was to determine the safety and efficacy of spinal column shortening for tethered cord syndrome by analyzing their experience with this surgical technique. METHODS The authors retrospectively reviewed the demographic and procedural data of children and young adults who had undergone spinal column shortening for primary or secondary tethered cord syndrome. RESULTS Seven patients with tethered cord syndrome caused by myelomeningocele, lipomyelomeningocele, and transitional spinal lipoma were treated with spinal column shortening. One patient with less than 24 months of follow-up was excluded from further analysis. There were 3 males and 4 females; the average age at the time was surgery was 16 years (range 8-30 years). Clinical presentations for our patients included pain (in 5 patients), weakness (in 4 patients), and bowel/bladder dysfunction (in 4 patients). Spinal column osteotomy was most commonly performed at the L-1 level, with fusion between T-12 and L-2 using a pedicle screw-rod construct. Pedicle subtraction osteotomy was performed in 6 patients, and vertebral column resection was performed in 1 patient. The average follow-up period was 31 months (range 26-37 months). Computed tomography-based radiographic outcomes showed solid

Post-endoscopic biliary sphincterotomy bleeding: an interventional radiology approach.

LENUS (Irish Health Repository)

Dunne, Ruth

2013-12-01

Endoscopic sphincterotomy is an integral component of endoscopic retrograde cholangiopancreatography. Post-sphincterotomy hemorrhage is a recognized complication. First line treatment involves a variety of endoscopic techniques performed at the time of sphincterotomy. If these are not successful, transcatheter arterial embolization or open surgical vessel ligation are therapeutic considerations.

Endogenous opioids are involved in abnormal stereotyped behaviour of tethered sows

NARCIS (Netherlands)

Cronin, G.M.; Wiepkema, P.R.; Ree, van J.M.

1985-01-01

Tethered sows continuously performed stereotypies during a substantial part of the day time. A single subcutaneous injection with naloxone significantly decreased the profound stereotypies, while explorative behaviours of pigs were not affected by naloxone. In addition a long-term effect of naloxone

Endogenous opioids are involved in abnormal stereotyped behaviours of tethered sows

NARCIS (Netherlands)

Cronin, G.M.; Wiepkema, P.R.; Ree, J.M. van

1985-01-01

Tethered sows continuously performed stereotypies during a substantial part of the day time. A single subcutaneous injection with naloxone significantly decreased the profound stereotypies, while explorative behaviours of pigs were not affected by naloxone. In addition a long-term effect of naloxone

TETHERED BALLOON MEASUREMENTS OF BIOGENIC VOCS IN THE ATMOSPHERIC BOUNDARY LAYER

Science.gov (United States)

Measurements of biogenic volatile organic compounds (BVOCs) have been made on a tethered balloon platform in eleven field deployments between 1985 and 1996. A series of balloon sampling packages have been developed for these campaigns and they have been used to describe boundary ...

Endoscopic electrosurgical papillotomy and manometry in biliary tract disease.

Science.gov (United States)

Geenen, J E; Hogan, W J; Shaffer, R D; Stewart, E T; Dodds, W J; Arndorfer, R C

1977-05-09

Endoscopic papillotomy was performed in 13 patients after cholecystectomy for retained or recurrent common bile duct calculi (11 patients) and a clinical picture suggesting papillary stenosis (two patients). Following endoscopic papillotomy, ten of the 11 patients spontaneously passed common bile duct (CBD) stones verified on repeated endoscopic retrograde cholangiopancreatography (ERCP) study. One patient failed to pass a large CBD calculus; one patient experienced cholangitis three months after in inadequate papillotomy and required operative intervention. Endoscopic papillotomy substantially decreased the pressure gradient existing between the CBD and the duodenum in all five patients studied with ERCP manometry. Endoscopic papillotomy is a relatively safe and effective procedure for postcholecystectomy patients with retained or recurrent CBD stones. The majority of CBD stones will pass spontaneously if the papillotomy is adequate.

Huge biloma after endoscopic retrograde cholangiopancreatography and endoscopic biliary sphincterotomy

Directory of Open Access Journals (Sweden)

Harith M. Alkhateeb

2015-01-01

Conclusions: (1 Following endoscopic retrograde cholangiopancreatography, a patient’s complaints should not be ignored. (2 A massive biloma can occur due to such procedures. (3 Conservative treatment with minimal invasive technique can prove to be effective.

Adhesive capsulitis of the shoulder: evaluation with MR arthrography

International Nuclear Information System (INIS)

Jung, Joon-Yong; Jee, Won-Hee; Chun, Ho Jong; Kim, Yang-Soo; Chung, Yang Guk; Kim, Jung-Man

2006-01-01

The purpose of this study was to determine the usefulness of magnetic resonance (MR) arthrography for diagnosing adhesive capsulitis. Shoulder MR images of 28 patients with (n=14) and without (n=14) adhesive capsulitis were retrospectively analyzed. MR images were assessed for capsule and synovium thickness as well as the width of the axillary recess on oblique coronal fat-suppressed T1-weighted images and T2-weighted images, respectively. On oblique sagittal fat-suppressed T1-weighted images, the width of the rotator interval and the presence of abnormal tissue in the interval were evaluated. Significant differences were found between the two groups in capsule and synovium thickness on both sides of the recess on oblique coronal T2-weighted images (P=0.000), whereas thickness on the humeral aspect showed no significant difference on oblique coronal fat-suppressed T1-weighted images (P=0.109). On oblique coronal T2-weighted images, a cut-off value of 3-mm thickness gave the highest diagnostic accuracy for adhesive capsulitis with sensitivity, specificity, and accuracy of 79% (11/14), 100% (14/14), and 89% (25/28) at the humeral side and 93% (13/14), 86% (12/14), and 89% (25/28) at the glenoid side, respectively. There were significant differences in rotator interval width, presence of abnormal tissue in the rotator interval, and axillary recess width between the two groups (P<0.05). Thickness of capsule and synovium of the axillary recess greater than 3 mm is a practical MR criterion for diagnosing adhesive capsulitis when measured on oblique coronal T2-weighted MR arthrography images without fat suppression. The presence of abnormal tissue in the rotator interval showed high sensitivity but rather low specificity. (orig.)

Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2

Science.gov (United States)

Lorenzini, E. C.; Arnold, D. A.; Cosmo, M.; Grossi, M. D.

1986-10-01

The following topics related to the dynamics of the 4-mass tethered system are addressed: (1) the development of damping algorithms for damping the out-of-plane libration of the system and the interaction of the out-of-plane control with the other degrees of freedom; and (2) the development of environmental models to be added to the dynamics simulation computer code. The environmental models are specifically a new drag routine based on the Jacchia's 1977 model, a J(2) model and an accurate thermal model of the wire. Regarding topic (1) a survey of various out-of-plane libration control laws was carried out. Consequently a yo-yo control law with amplitude of the tether length variation proportional to the amplitude of the out-of-game libration has been selected. This control law provides good damping when applied to a (theoretical) two-dimensional system. In the actual 3-dimensional 4-mass tethered system, however, energy is transferred to the least damped degrees of freedom (the out-of-plane lateral deflections are still undamped in the present simulations) in such a way as to decrease the effectiveness of the algorithm for out-of-plane libration control. The addition of damping algorithms for the out-of-plane lateral deflections is therefore necessary.

Method for radiometric calibration of an endoscope's camera and light source

Science.gov (United States)

Rai, Lav; Higgins, William E.

2008-03-01

An endoscope is a commonly used instrument for performing minimally invasive visual examination of the tissues inside the body. A physician uses the endoscopic video images to identify tissue abnormalities. The images, however, are highly dependent on the optical properties of the endoscope and its orientation and location with respect to the tissue structure. The analysis of endoscopic video images is, therefore, purely subjective. Studies suggest that the fusion of endoscopic video images (providing color and texture information) with virtual endoscopic views (providing structural information) can be useful for assessing various pathologies for several applications: (1) surgical simulation, training, and pedagogy; (2) the creation of a database for pathologies; and (3) the building of patient-specific models. Such fusion requires both geometric and radiometric alignment of endoscopic video images in the texture space. Inconsistent estimates of texture/color of the tissue surface result in seams when multiple endoscopic video images are combined together. This paper (1) identifies the endoscope-dependent variables to be calibrated for objective and consistent estimation of surface texture/color and (2) presents an integrated set of methods to measure them. Results show that the calibration method can be successfully used to estimate objective color/texture values for simple planar scenes, whereas uncalibrated endoscopes performed very poorly for the same tests.

Duodenal diverticular bleeding: an endoscopic challenge

Directory of Open Access Journals (Sweden)

Eduardo Valdivielso-Cortázar

Full Text Available Duodenal diverticula are an uncommon cause of upper gastrointestinal bleeding. Until recently, it was primarily managed with surgery, but advances in the field of endoscopy have made management increasingly less invasive. We report a case of duodenal diverticular bleeding that was endoscopically managed, and review the literature about the various endoscopic therapies thus far described.

Evaluation of robotically controlled advanced endoscopic instruments

NARCIS (Netherlands)

Reilink, Rob; Kappers, Astrid M.L.; Stramigioli, Stefano; Misra, Sarthak

Background Advanced flexible endoscopes and instruments with multiple degrees of freedom enable physicians to perform challenging procedures such as the removal of large sections of mucosal tissue. However, these advanced endoscopes are difficult to control and require several physicians to

Chord length distribution for a compound capsule

International Nuclear Information System (INIS)

Pitřík, Pavel

2017-01-01

Chord length distribution is a factor important in the calculation of ionisation chamber responses. This article describes Monte Carlo calculations of the chord length distribution for a non-convex compound capsule. A Monte Carlo code was set up for generation of random chords and calculation of their lengths based on the input number of generations and cavity dimensions. The code was written in JavaScript and can be executed in the majority of HTML viewers. The plot of occurrence of cords of different lengths has 3 peaks. It was found that the compound capsule cavity cannot be simply replaced with a spherical cavity of a triangular design. Furthermore, the compound capsule cavity is directionally dependent, which must be taken into account in calculations involving non-isotropic fields of primary particles in the beam, unless equilibrium of the secondary charged particles is attained. (orig.)

Comparative assessment of hepatic Glisson's capsule and bovine pericardium in heart valve bioprostheses.

Science.gov (United States)

Kagramanov, I I; Kokshenev, I V; Dobrova, N B; Kastava, V T; Serov, R A; Zaets, S B

1998-05-01

The optimal material for heart valve bioprostheses remains disputable. This investigation was initiated to compare the properties of hepatic Glisson's capsule, clinical experience of which in cardiovascular surgery is minimal, with those of bovine pericardium. Hepatic Glisson's capsule was harvested from bull calves and used to create composite pulmonary arterial monocusp grafts and bioprostheses. Comparison of the strength and elastic properties of Glisson's capsule and bovine pericardium, as well as the hydrodynamic characteristics of valves made from these materials, was performed. Late results of operations using these materials were estimated echocardiographically. Although Glisson's capsule tissue is thinner than the bovine pericardium, its elasticity modulus is greater. However, the hydrodynamic characteristics of heart valves made from either tissue are similar. Moreover, valves made from Glisson's capsule have a lower systolic pressure gradient on the prosthesis and a higher effective orifice area. Composite pulmonary arterial xenopericardial grafts with a monocusp of Glisson's capsule were used in 30 patients during tetralogy of Fallot repair. Glisson's capsule was also used for tricuspid valve reconstruction and as a bioprosthesis in six patients with Ebstein's anomaly. At 1-2 years after surgery, the Glisson's capsule tissue remained thin and flexible, with no calcification. Although the hydrodynamic properties of hepatic Glisson's capsule and the bovine pericardium are similar, the capsule tissue is thinner and has a greater elasticity modulos. Thus, Glisson's capsule may be used for bioprosthesis construction both independently and in combination with bovine pericardium.

Capsule Performance Optimization for the National Ignition Facility

Science.gov (United States)

Landen, Otto

2009-11-01

The overall goal of the capsule performance optimization campaign is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. This will be accomplished using a variety of targets that will set key laser, hohlraum and capsule parameters to maximize ignition capsule implosion velocity, while minimizing fuel adiabat, core shape asymmetry and ablator-fuel mix. The targets include high Z re-emission spheres setting foot symmetry through foot cone power balance [1], liquid Deuterium-filled ``keyhole'' targets setting shock speed and timing through the laser power profile [2], symmetry capsules setting peak cone power balance and hohlraum length [3], and streaked x-ray backlit imploding capsules setting ablator thickness [4]. We will show how results from successful tuning technique demonstration shots performed at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design meet the required sensitivity and accuracy. We will also present estimates of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors, and show that these get reduced after a number of shots and iterations to meet an acceptable level of residual uncertainty. Finally, we will present results from upcoming tuning technique validation shots performed at NIF at near full-scale. Prepared by LLNL under Contract DE-AC52-07NA27344. [4pt] [1] E. Dewald, et. al. Rev. Sci. Instrum. 79 (2008) 10E903. [0pt] [2] T.R. Boehly, et. al., Phys. Plasmas 16 (2009) 056302. [0pt] [3] G. Kyrala, et. al., BAPS 53 (2008) 247. [0pt] [4] D. Hicks, et. al., BAPS 53 (2008) 2.

Compact, planar, translational piezoelectric bimorph actuator with Archimedes’ spiral actuating tethers

International Nuclear Information System (INIS)

Yang, Chenye; Liu, Sanwei; Livermore, Carol; Xie, Xin

2016-01-01

The design, analytical modelling, finite element analysis (FEA), and experimental characterization of a microelectromechanical system (MEMS) out-of-plane (vertical) translational piezoelectric lead–zirconate–titanate (PZT) bimorph actuator supported on Archimedes’ spiral tethers are presented. Three types of bimorph actuators with different electrode patterns (with spiral tethers half actuated, fully actuated with uniform polarity, or fully actuated with reversed polarity) are designed and modelled. The two actuators with the highest predicted performance (half actuated and fully actuated with uniform polarity) are implemented and characterized. Both designs are fabricated by commercial processes and are compatible with integration into more complex MEMS systems. Analytical modelling and FEA are used to analyze and predict the actuators’ displacements and blocking forces. Experimental measurements of the deflections and blocking forces of actuators with full uniform actuation and half actuation validate the design. At an applied voltage of 110 V, the out-of-plane deflections of the actuators with half actuation and full uniform actuation are measured at about 17 µ m and 29 µ m respectively, in good agreement with analytical predictions of 17.3 µ m and 34.2 µ m and FEA predictions of 17.1 µ m and 25.8 µ m. The blocking force for devices with half-actuated tethers is predicted to be 12 mN (analytical) and 10 mN (FEA), close to the experimental value of 9 mN. The blocking force for devices with full uniform actuation is predicted to be 23 mN (analytical) and 17 mN (FEA), as compared with 15 mN in experiments. (paper)

[Current Status of Endoscopic Resection of Early Gastric Cancer in Korea].

Science.gov (United States)

Jung, Hwoon Yong

2017-09-25

Endoscopic resection (Endoscopic mucosal resection [EMR] and endoscopic submucosal dissection [ESD]) is already established as a first-line treatment modality for selected early gastric cancer (EGC). In Korea, the number of endoscopic resection of EGC was explosively increased because of a National Cancer Screening Program and development of devices and techniques. There were many reports on the short-term and long-term outcomes after endoscopic resection in patients with EGC. Long-term outcome in terms of recurrence and death is excellent in both absolute and selected expanded criteria. Furthermore, endoscopic resection might be positioned as primary treatment modality replacing surgical gastrectomy. To obtain these results, selection of patients, perfect en bloc procedure, thorough pathological examination of resected specimen, accurate interpretation of whole process of endoscopic resection, and rational strategy for follow-up is necessary.

Thermal analysis of an instrumented capsule using an ANSYS program

International Nuclear Information System (INIS)

Choi, Myoung Hwan; Choo, Kee Nam; Kang, Young Hwan; Cho, Man Soon; Sohn, Jae Min; Kim, Bong Goo

2006-01-01

An instrumented capsule has been used for an irradiation test of various nuclear materials in the research reactor, HANARO. To obtain the design data of the instrumented capsule, a thermal analysis is performed using a finite element analysis program, ANSYS. The 2-dimensional model for a cross section of the capsule including the specimens is generated, and a gamma-heating rate of the materials for the HANARO power of 24 or 30 MW is considered as an input force. The effect of the gap size and the control rod position on the temperature of the specimens or other components is discussed. From the analysis it is found that the gap between the thermal media and the external tube has a significant effect on the temperature of the specimen. In the case of the material capsule, the maximum temperature for the reactor power of 24 MW is 255degC for an irradiation test and 257degC for a FE analysis at the center stage of the capsule in the axial direction. It is expected that the analysis models using an ANSYS program will be useful in designing the instrumented capsules for an irradiation test and estimating the test results. (author)

The secret life of tethers: the role of tethering factors in SNARE complex regulation

Directory of Open Access Journals (Sweden)

Michelle L Dubuke

2016-05-01

Full Text Available Trafficking in eukaryotic cells is a tightly regulated process to ensure correct cargo delivery to the proper destination organelle or plasma membrane. In this review, we focus on how the vesicle fusion machinery, the SNARE complex, is regulated by the interplay of the multisubunit tethering complexes (MTC with the SNAREs and Sec1/Munc18 (SM proteins. Although these factors are used in different stages of membrane trafficking, e.g. Golgi to plasma membrane transport vs vacuolar fusion, and in a variety of diverse eukaryotic cell types, many commonalities between their functions are being revealed. We explore the various protein-protein interactions and findings from functional reconstitution studies in order to highlight both their common features and the differences in their modes of regulation. These studies serve as a starting point for mechanistic explorations in other systems.

Endoscopic Management of Peri-Pancreatic Fluid Collections.

Science.gov (United States)

Yip, Hon Chi; Teoh, Anthony Yuen Bun

2017-09-15

In the past decade, there has been a progressive paradigm shift in the management of peri-pancreatic fluid collections after acute pancreatitis. Refinements in the definitions of fluid collections from the updated Atlanta classification have enabled better communication amongst physicians in an effort to formulate optimal treatments. Endoscopic ultrasound (EUS)-guided drainage of pancreatic pseudocysts has emerged as the procedure of choice over surgical cystogastrostomy. The approach provides similar success rates with low complications and better quality of life compared with surgery. However, an endoscopic "step up" approach in the management of pancreatic walled-off necrosis has also been advocated. Both endoscopic and percutaneous drainage routes may be used depending on the anatomical location of the collections. New-generation large diameter EUS-specific stent systems have also recently been described. The device allows precise and effective drainage of the collections and permits endoscopic necrosectomy through the stents.

Safety Analysis Report for Primary Capsule of Ir-192 Radiation Source

International Nuclear Information System (INIS)

Lee, J. C.; Bang, K. S.; Choi, W. S.; Seo, K. S.; Son, K. J.; Park, W. J.

2008-12-01

All of the source capsules to transport a special form radioactive material should be designed and fabricated in accordance with the design criteria prescribed in IAEA standards and domestic regulations. The objective of this project is to prove the safety of a primary capsule for Ir-192 radiation source which produced in the HANARO. The safety tests of primary capsules were carried out for the impact, percussion and heat conditions. And leakage tests were carried out before and after the each tests. The capsule showed slight scratches and their deformations were not found after each tests. It also met the allowable limits of leakage rate after each test. Therefore, it has been verified that the capsule was designed and fabricated to meet all requirements for the special form radioactive materials

Tethered Lubricants for Small Systems

Energy Technology Data Exchange (ETDEWEB)

Lynden A. Archer

2006-01-09

The objective of this research project is two-fold. First, to fundamentally understand friction and relaxation dynamics of polymer chains near surfaces; and second, to develop novel self-lubricated substrates suitable for MEMS devices. During the three-year performance period of this study the PI and his students have shown using theory and experiments that systematic introduction of disorder into tethered lubricant coatings (e.g. by using self-assembled monolayer (SAM) mixtures or SAMs with nonlinear, branched architectures) can be used to significantly reduce the friction coefficient of a surface. They have also developed a simple procedure based on dielectric spectroscopy for quantifying the effect of surface disorder on molecular relaxation in lubricant coatings. Details of research accomplishments in each area of the project are described in the body of the report.

Theseus: tethered distributed robotics (TDR)

Science.gov (United States)

Digney, Bruce L.; Penzes, Steven G.

2003-09-01

The Defence Research and Development Canada's (DRDC) Autonomous Intelligent System's program conducts research to increase the independence and effectiveness of military vehicles and systems. DRDC-Suffield's Autonomous Land Systems (ALS) is creating new concept vehicles and autonomous control systems for use in outdoor areas, urban streets, urban interiors and urban subspaces. This paper will first give an overview of the ALS program and then give a specific description of the work being done for mobility in urban subspaces. Discussed will be the Theseus: Thethered Distributed Robotics (TDR) system, which will not only manage an unavoidable tether but exploit it for mobility and navigation. Also discussed will be the prototype robot called the Hedgehog, which uses conformal 3D mobility in ducts, sewer pipes, collapsed rubble voids and chimneys.

Therapeutic applications of radioactive 131iodine: Procedures and incidents with capsules

International Nuclear Information System (INIS)

Al Aamri, Marwa; Ravichandran, Ramamoorthy; Binukumar, John Pichy; Al Balushi, Naima

2016-01-01

Treatments for thyrotoxicosis and carcinoma thyroid are carried out by oral administration of radioactive iodine ( 131 I) in the form of liquid or capsules. The liquid form of 131 I has higher risk factors such as vapourization, spillage and need for management of higher activity wastes. Use of 131 I in capsule form simplify procedures of handling compared to liquid form of 131 I. The guidelines of safe handling and quality assurance aspects for therapeutic use 131 I are well outlined by International Atomic Energy Agency (IAEA) reports. A few unusual incidents with I-131 capsules encountered in the past need to be highlighted from health physics point of view. In Royal Hospital, Oman, I-131 is imported in capsules, and the total activity handled/year steadily increased over 10 years. Discrete activities range from 185 MBq (5 mCi) up to 7.4 GBq (200 mCi). In four incidents deviations in standard operational procedures were recorded. Nature of incidents is described as follows: (1) After assay of activity, the capsule was directly put in the lead container with missing of inner cap. (2) Patient poured water in the Perspex tube, when the capsule was handed over to her, making an emergency situation. (3) In 3 high activity capsules (2 nos 2.96 GBq, 1 no. 4.26 GBq), observed sticky behavior in capsule holder on the 2 nd day post receipt, which were in order on the 1 st day. (4) A capsule could not be swallowed by a patient, which was taken back from the mouth. Monitoring of patient later did not show residual ingested activity. The report documents some of the unusual incidents for information to other centers engaged in such radioactive administrations

Myofibroblast Numbers are Elevated in Human Elbow Capsules After Trauma

OpenAIRE

Hildebrand, Kevin A.; Zhang, Mei; van Snellenberg, Wistara; King, Graham J. W.; Hart, David A.

2004-01-01

Elbow contractures, a frequent problem after injury, can be treated by excision of the joint capsule. However, the underlying changes in the joint capsule are poorly understood. Based on skin healing work, we examined the hypotheses that myofibroblast numbers and expression of a myofibroblast marker α-smooth muscle actin, are elevated in patients with posttraumatic joint contractures. Anterior capsules were obtained from six patients who had operative release of posttraumatic contractures gre...

Cholesterol tethered bioresponsive polycation as a candidate for gene delivery

Energy Technology Data Exchange (ETDEWEB)

Zhu Ying [Second Affiliated Hospital, Medical College, Zhejiang University, Hangzhou 310009 (China); Wang Youxiang, E-mail: yx_wang@zju.edu.cn [Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Zhejiang University, Hangzhou 310027 (China); Hu Qiaoling; Shen Jiacong [Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Zhejiang University, Hangzhou 310027 (China)

2009-04-30

The efficient unpacking of viral protein shell gave the inspiration for the synthesized vectors. In this research, novel cholesterol tethered bioresponsive polyethylenimine (PEI) was specially designed via disulfide-containing cross-linker. The cholesterol lipid had proved to increase the permeability of gene vector through cell membrane. The acid-base titration indicated that the synthesized polycation possessed efficient proton sponge effect, which was suggested to increase endosomal release of pDNA complexes into the cytoplasm. The cholesterol tethered polycation could effectively induce DNA condensation and form spherical particles with diameter about 200 nm at N/P ratio of 10. At glutathione concentration of 3 mM, the polyplexes were unpacked due to the bioresponsive cleavage of the disulfide bonds. The in-vitro experiment indicated that the polyplexes showed efficient transfection efficiency to HEK293T cells. All the results indicated that the bioresponsive polycation could be served as an effective trigger to control the release of DNA at the intracellular environment. The novel bioresponsive polycation might have great potential in non-viral gene delivery research and application.

Endoscopic management of peripancreatic fluid collections.

Science.gov (United States)

Goyal, Jatinder; Ramesh, Jayapal

2015-07-01

Peripancreatic fluid collections are a well-known complication of pancreatitis and can vary from fluid-filled collections to entirely necrotic collections. Although most of the fluid-filled pseudocysts tend to resolve spontaneously with conservative management, intervention is necessary in symptomatic patients. Open surgery has been the traditional treatment modality of choice though endoscopic, laparoscopic and transcutaneous techniques offer alternative drainage approaches. During the last decade, improvement in endoscopic ultrasound technology has enabled real-time access and drainage of fluid collections that were previously not amenable to blind transmural drainage. This has initiated a trend towards use of this modality for treatment of pseudocysts. In this review, we have summarised the existing evidence for endoscopic drainage of peripancreatic fluid collections from published studies.

Fabrication of Non-instrumented capsule for DUPIC simulated fuel irradiation test in HANARO