Fine fuel heating by radiant flux

Treesearch

David Frankman; Brent W. Webb; Bret W. Butler; Don J. Latham

2010-01-01

Experiments were conducted wherein wood shavings and Ponderosa pine needles in quiescent air were subjected to a steady radiation heat flux from a planar ceramic burner. The internal temperature of these particles was measured using fine diameter (0.076mm diameter) type K thermocouples. A narrow angle radiometer was used to determine the emissive power generated by the...

Methanol Droplet Extinction in Oxygen/Carbon-dioxide/Nitrogen Mixtures in Microgravity: Results from the International Space Station Experiments

NASA Technical Reports Server (NTRS)

Nayagam, Vedha; Dietrich, Daniel L.; Ferkul, Paul V.; Hicks, Michael C.; Williams, Forman A.

2012-01-01

Motivated by the need to understand the flammability limits of condensed-phase fuels in microgravity, isolated single droplet combustion experiments were carried out in the Combustion Integrated Rack Facility onboard the International Space Station. Experimental observations of methanol droplet combustion and extinction in oxygen/carbon-dioxide/nitrogen mixtures at 0.7 and 1 atmospheric pressure in quiescent microgravity environment are reported for initial droplet diameters varying between 2 mm to 4 mm in this study.The ambient oxygen concentration was systematically lowered from test to test so as to approach the limiting oxygen index (LOI) at fixed ambient pressure. At one atmosphere pressure, ignition and some burning were observed for an oxygen concentration of 13% with the rest being nitrogen. In addition, measured droplet burning rates, flame stand-off ratios, and extinction diameters are presented for varying concentrations of oxygen and diluents. Simplified theoretical models are presented to explain the observed variations in extinction diameter and flame stand-off ratios.

Analysis of daylight performance of solar light pipes influenced by size and shape of sunlight captures

NASA Astrophysics Data System (ADS)

Wu, Yanpeng; Jin, Rendong; Zhang, Wenming; Liu, Li; Zou, Dachao

2009-11-01

Experimental investigations on three different sunlight captures with diameter 150mm, 212mm, 300mm were carried out under different conditions such as sunny conditions, cloudy conditions and overcast conditions and the two different size solar light pipes with diameter 360mm and 160mm under sunny conditions. The illuminance in the middle of the sunlight capture have relationship with its size, but not linear. To improve the efficiency of the solar light pipes, the structure and the performance of the sunlight capture must be enhanced. For example, University of Science and Technology Beijing Gymnasium, Beijing 2008 Olympic events of Judo and Taekwondo, 148 solar light pipes were installed with the diameter 530mm for each light pipe. Two sunlight captures with different shape were installed and tested. From the measuring results of the illuminance on the work plane of the gymnasium, the improvement sunlight captures have better effects with the size of augmenting and the machining of the internal surface at the same time, so that the refraction increased and the efficiency of solar light pipes improved. The better effects of supplementary lighting for the gymnasium have been achieved.

A study of the rheological properties of endodontic sealers.

PubMed

Lacey, S; Pitt Ford, T R; Watson, T F; Sherriff, M

2005-08-01

To test the hypothesis that there would be no statistically significant difference in viscosity-related measures of endodontic sealers or change in these with strain rate, internal diameter or powder : liquid ratio in a capillary system. Materials used were Apexit, Tubliseal EWT, Grossman's sealer and Ketac-endo. Viscosity-related measures were tested in a two-plate test, and in a capillary rheometer. The mean values (n = 12) for thickness and diameter of material formed between two glass plates were tested with one-way analysis of variance. Pressure was applied to a capillary rheometer at strain rates 5 and 10 mm min(-1) in tubes of internal diameter 0.6 and 1.2 mm. Tubliseal EWT had a thinner film thickness than the other sealers (alpha = 0.05). The difference in diameter between Tubliseal EWT and the other sealers was significant apart from Apexit. Increased strain rate gave a significant increase (alpha = 0.05) in the flow of all sealers. Narrower tubes produced increased velocity, which was significant for all sealers, and reduced volumetric flow, which was significant for all sealers except Grossman's 2 : 1 (Wilcoxon signed rank test). Reduction in powder : liquid ratio of Grossman's significantly increased flow in narrow tubes and at higher strain rate (Mann-Whitney test). There was a significant difference between the flow of Tubliseal EWT and the other sealers tested in the two-plate test; capillary flow was affected by sealer, internal diameter, strain rate and powder : liquid ratio. The null hypotheses were rejected.

Effects of laser-weld joint opening size on fatigue strength of Ti-6Al-4V structures with several diameters.

PubMed

Nuñez-Pantoja, J M C; Vaz, L G; Nóbilo, M A A; Henriques, G E P; Mesquita, M F

2011-03-01

This study was conducted to evaluate the fatigue strength of Ti-6Al-4V laser-welded joints with several diameters and joint openings. Sixty dumbbell rods were machined in Ti-6Al-4V alloy with central diameters of 1·5, 2·0 and 3·5 mm. The specimens were sectioned and then welded using two joint openings (0·0 and 0·6 mm). The combination of variables created six groups, which when added to the intact groups made a total of nine groups (n = 10). Laser welding was executed as follows: 360 V per 8 ms (1·5 and 2·0 mm) and 380 V per 9 ms (3·5 mm) with focus and frequency regulated to zero. The joints were finished, polished and submitted to radiographic examination to be analysed visually for the presence of porosity. The specimens were then subjected to a mechanical cyclic test, and the number of cycles until failure was recorded. The fracture surface was examined with a scanning electron microscope (SEM). The Kruskal-Wallis test and Dunn test (α = 0·05) indicated that the number of cycles required for fracture was lower for all specimens with joint openings of 0·6 mm, and for 3·5-mm-diameter specimens with joint openings of 0·0 mm. The Spearman correlation coefficient (α = 0·05) indicated that there was a negative correlation between the number of cycles and the presence of porosity. So, laser welding of Ti-6Al-4V structures with a thin diameter provides the best conditions for the juxtaposition of parts. Radiographic examination allows for the detection of internal voids in titanium joints. © 2010 Blackwell Publishing Ltd.

The uniform chest compression depth of 50 mm or greater recommended by current guidelines is not appropriate for all adults.

PubMed

Lee, Soo Hoon; Kim, Dong Hoon; Kang, Tae-Sin; Kang, Changwoo; Jeong, Jin Hee; Kim, Seong Chun; Kim, Dong Seob

2015-08-01

This study was conducted to evaluate the appropriateness of the chest compression (CC) depth recommended in the current guidelines and simulated external CCs, and to characterize the optimal CC depth for an adult by body mass index (BMI). Adult patients who underwent chest computed tomography as a screening test for latent pulmonary diseases in the health care center were enrolled in this study. We calculated the internal anteroposterior (AP) diameter (IAPD) and external AP diameter (EAPD) of the chest across BMIs (<18.50, 18.50-24.99, 25.00-29.99, and ≥30.00 kg/m(2)) for simulated CC depth. We also calculated the residual chest depths less than 20 mm for simulated CC depth. There was a statistically significant difference in the chest EAPD and IAPD measured at the lower half of the sternum for each BMI groups (EAPD: R(2) = 0.638, P < .001; IAPD: R(2) = 0.297, P < .001). For one-half external AP CC, 100% of the patients, regardless of BMI, had a calculated residual internal chest depth less than 20 mm. For one-fourth external AP CC, no patients had a calculated residual internal chest depth less than 20 mm. For one-third external AP CC, only 6.48% of the patients had a calculated residual internal chest depth less than 20 mm. It is not appropriate that the current CC depth (≥50 mm), expressed only as absolute measurement without a fraction of the depth of the chest, is applied uniformly in all adults. In addition, in terms of safety and efficacy, simulated CC targeting approximately between one-third and one-fourth EAPD CC depth might be appropriate. Copyright © 2015 Elsevier Inc. All rights reserved.

Application of X-ray television image system to observation in solid rocket motor

NASA Astrophysics Data System (ADS)

Fujiwara, T.; Ito, K.; Tanemura, T.; Shimizu, M.; Godai, T.

The X-ray television image system is used to observe the solid propellant burning surface during rocket motor operation as well as to inspect defects in solid rocket motors in a real time manner. This system can test 200 mm diameter dummy propellant rocket motors with under 2 percent discriminative capacity. Viewing of a 50 mm diameter internal-burning rocket motor, propellant burning surface time transition and propellant burning process of the surroundings of artificial defects were satisfactorily observed. The system was demonstrated to be effective for nondestructive testing and combustion research of solid rocket motors.

Differences and similarities of the Eocene to recent Sphaerogypsina tests collected from the Pannonian basin to the Adriatic Sea

NASA Astrophysics Data System (ADS)

Drobne, Katica; Ćosović, Vlasta; Čretnik, Janko; Turk, Janez; Briguglio, Antonino; Rögl, Fred; Praprotnik, Anton

2017-04-01

With a new series of shots in the X-ray tomographic techniques (CT), the study of fossil (Eocene and Miocene) and recent tests of Sphaerogypsina globulus (Reuss, 1848) sensu lato, sampled in the Adriatic Sea and adjacent coastal areas, have continued. The Eocene, Lutetian samples collected at the NW margin of the Central Neotethys (Benkovac) contain tests up to 2 mm in diameters, while specimens found in Priabonian deposits from the southern outskirts of the Eastern Alps (Šuštarica, Ravna Gora) and in the central Pannonian basin (Eger) are smaller, with diameters of 1.2 mm. In the Oligocene, Rupelian, sediments, deposited in the Slovenian corridor, area south of the E. Alps, known as representing transition between recessing Neotethys and emerging Pannonian Sea, (Gornji grad, Nova Štifta), foraminiferal tests are of 1.1 mm in diameter. Globular tests of Miocene, Badenian, specimens (Nussdorf, north of the E. Alps), originally described as bryozoan Ceriopora globulus by Reuss 1848, attained 1.2 mm in diameter. Comparison of tests diameters shows that Middle Eocene sphaerogypsinids had the largest tests among fossil taxa, implying that warm temperatures suited them a lot. The Oligocene tests, were smaller and the trend of decreasing in size persisted in the Miocene. Recent tests, although collected over decades from different places in the Adriatic Sea, just recently have been systematically sampled at Pakleni Is. (Hvar), Kornati archipelago and Mali Čutin Is., and studied.The tests, with diameters ranging from 0.3 to 1.0 mm (an average of 0.6 to 0.8 mm), are very small in comparison with fossil forms. The life habitats, as type of substrate, light (sunny vs. shadowed areas) have been investigated, revealing that sphaerogypsinids prefer to live at water depth up to 50 - 60 m. Special attention is payed to find live specimens, which would provide the basis for DNA analysis. The application of micro- tomography contributed significantly in studying test internal structure, because virtual slicing of test micrometer by micrometer allow study of the finest changes in skeletal elements and their imaging or filming. In taxonomic study, the criteria defined in Illustrated Glossary by Hottinger (2006) are applied. Comparison of internal structures of fossil and recent tests show the following differences: the size of embryonic chambers, positions of nepiont, compacted or loose adult cycles, various diameters of the stacks ; and the similarity demonstrated by the ultimate way of forming the globular tests no matter how eccentric position of proloculi are.

Change in human lens dimensions, lens refractive index distribution and ciliary body ring diameter with accommodation.

PubMed

Khan, Adnan; Pope, James M; Verkicharla, Pavan K; Suheimat, Marwan; Atchison, David A

2018-03-01

We investigated changes in ciliary body ring diameter, lens dimensions and lens refractive index distributions with accommodation in young adults. A 3T clinical magnetic resonance imaging scanner imaged right eyes of 38 18-29 year old participants using a multiple spin echo sequence to determine accommodation-induced changes along lens axial and equatorial directions. Accommodation stimuli were approximately 1 D and 5 D. With accommodation, ciliary body ring diameter, and equatorial lens diameter decreased (-0.43 ± 0.31 mm and -0.30 ± 0.23 mm, respectively), and axial lens thickness increased ( + 0.34 ± 0.16 mm). Lens shape changes cause redistribution of the lens internal structure, leading to change in refractive index distribution profiles. With accommodation, in the axial direction refractive index profiles became flatter in the center and steeper near the periphery of the lens, while in the equatorial direction they became steeper in the center and flatter in the periphery. The results suggest that the anatomical accuracy of lens optical models can be improved by accounting for changes in the refractive index profile during accommodation.

Gender differences of airway dimensions in anatomically matched sites on CT in smokers.

PubMed

Kim, Yu-Il; Schroeder, Joyce; Lynch, David; Newell, John; Make, Barry; Friedlander, Adam; Estépar, Raúl San José; Hanania, Nicola A; Washko, George; Murphy, James R; Wilson, Carla; Hokanson, John E; Zach, Jordan; Butterfield, Kiel; Bowler, Russell P; Copdgene Investigators

2011-08-01

There are limited data on, and controversies regarding gender differences in the airway dimensions of smokers. Multi-detector CT (MDCT) images were analyzed to examine whether gender could explain differences in airway dimensions of anatomically matched airways in smokers. We used VIDA imaging software to analyze MDCT scans from 2047 smokers (M:F, 1021:1026) from the COPDGene® cohort. The airway dimensions were analyzed from segmental to subsubsegmental bronchi. We compared the differences of luminal area, inner diameter, wall thickness, wall area percentage (WA%) for each airway between men and women, and multiple linear regression including covariates (age, gender, body sizes, and other relevant confounding factors) was used to determine the predictors of each airway dimensions. Lumen area, internal diameter and wall thickness were smaller for women than men in all measured airway (18.4 vs 22.5 mm(2) for segmental bronchial lumen area, 10.4 vs 12.5 mm(2) for subsegmental bronchi, 6.5 vs 7.7 mm(2) for subsubsegmental bronchi, respectively p < 0.001). However, women had greater WA% in subsegmental and subsubsegmental bronchi. In multivariate regression, gender remained one of the most significant predictors of WA%, lumen area, inner diameter and wall thickness. Women smokers have higher WA%, but lower luminal area, internal diameter and airway thickness in anatomically matched airways as measured by CT scan than do male smokers. This difference may explain, in part, gender differences in the prevalence of COPD and airflow limitation.

Measurement of the ascending aorta diameter in patients with severe bicuspid and tricuspid aortic valve stenosis using dual-source computed tomography coronary angiography.

PubMed

Son, Jee Young; Ko, Sung Min; Choi, Jin Woo; Song, Meong Gun; Hwang, Hweung Kon; Lee, Sook Jin; Kang, Joon-Won

2011-12-01

We aimed to evaluate the diagnostic performance of dual-source computed tomography coronary angiography (DSCT-CA) in the measurement of the ascending aorta (AA) diameter and compare the AA diameter in patients with severe bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) stenosis. Eighty-eight consecutive patients (50 men, mean age 60.3 ± 13 year) with severe aortic stenosis (AS) underwent DSCT-CA before aortic valve surgery. Seventy-four of the 88 patients underwent cardiovascular magnetic resonance (CMR). The internal diameter of AA was measured from early-systole with DSCT-CA and CMR by 2 radiologists independently at 4 levels (aortic annulus, sinuses of Valsalva, sinotubular junction, and tubular portion at the right pulmonary artery). The patients were divided in to 2 groups (BAV [n = 53]; TAV [n = 35]) according to operative findings. Patients with BAV were significantly younger than those with TAV (P = 0.0035). Inter-observer agreement of AA diameters at 4 levels with DSCT-CA and CMR was excellent (intraclass correlation coefficient = 0.89-0.97). Also, the DSCT-CA and CMR measurements of the AA diameter strongly correlated (r = 0.871-0.976). Mean diameter of the AA by DSCT-CA was significantly larger in patients with BAV (34.4 ± 8.2 mm) as compared to those with TAV (30.6 ± 5.5 mm). The diameters at the sinuses of Valsalva, sinotubular junction, and tubular portion were significantly larger in BAV than in TAV. Twenty-two of 53 (41.5%) patients with BAV and 2 of 35 (5.7%) patients with TAV had AA dilatation > 45 mm. DSCT-CA allows accurate assessment of the AA diameters in patients with severe AS. Patients with severe BAV stenosis had larger AA diameters and higher prevalence of AA dilatation > 45 mm as compared to those with severe TAV stenosis.

A helical scintillating fiber hodoscope

NASA Astrophysics Data System (ADS)

Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Bissel, T.; Bollmann, R.; Busch, M.; Büßer, K.; Colberg, T.; Demirörs, L.; Diehl, O.; Dohrmann, F.; Engelhardt, H. P.; Eversheim, P. D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Groß, A.; Groß-Hardt, R.; Hinterberger, F.; Jahn, R.; Jeske, M.; Jonas, E.; Krause, H.; Lahr, U.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuck, T.; Meinerzhagen, A.; Nähle, O.; Pfuff, M.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; von Rossen, P.; Sanz, B.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Thomas, S.; Trelle, H. J.; Weise, E.; Wellinghausen, A.; Wiedmann, W.; Woller, K.; Ziegler, R.; EDDA Collaboration

1999-07-01

A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9°⩽ Θ⩽72° and 0°⩽ ϕ⩽360° in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes.

INTERNAL REPAIR OF GAS PIPLINES SURVEY OF OPERATOR EXPERIENCE AND INDUSTRY NEEDS REPORT

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

Ian D. Harris

2003-09-01

A repair method that can be applied from the inside of a gas transmission pipeline (i.e., a trenchless repair) is an attractive alternative to conventional repair methods since the need to excavate the pipeline is precluded. This is particularly true for pipelines in environmentally sensitive and highly populated areas. The objectives of the project are to evaluate, develop, demonstrate, and validate internal repair methods for pipelines; develop a functional specification for an internal pipeline repair system; and prepare a recommended practice for internal repair of pipelines. The purpose of this survey is to better understand the needs and performance requirementsmore » of the natural gas transmission industry regarding internal repair. A total of fifty-six surveys were sent to pipeline operators. A total of twenty completed surveys were returned, representing a 36% response rate, which is considered very good given the fact that tailored surveys are known in the marketing industry to seldom attract more than a 10% response rate. The twenty survey responses produced the following principal conclusions: (1) Use of internal weld repair is most attractive for river crossings, under other bodies of water (e.g., lakes and swamps) in difficult soil conditions, under highways, under congested intersections, and under railway crossings. All these areas tend to be very difficult and very costly if, and where, conventional excavated repairs may be currently used. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling (HDD) when a new bore must be created to solve a leak or other problem in a water/river crossing. (3) The typical travel distances required can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). In concept, these groups require pig-based systems; despooled umbilical systems could be considered for the first two groups. For the last group a self-propelled system with an onboard self-contained power and welding system is required. (4) Pipe size range requirements range from 50.8 mm (2 in.) through 1,219.2 mm (48 in.) in diameter. The most common size range for 80% to 90% of operators surveyed is 508 mm to 762 mm (20 in. to 30 in.) diameter, with 95% using 558.8 mm (22 in.) diameter pipe.« less

Scapular thickness--implications for fracture fixation.

PubMed

Burke, Charity S; Roberts, Craig S; Nyland, John A; Radmacher, Paula G; Acland, Robert D; Voor, Michael J

2006-01-01

The purpose of this study was to measure and map scapula osseous thickness to identify the optimal areas for internal fixation. Eighteen (9 pairs) scapulae from 2 female and 7 male cadavers were used. After harvest and removal of all soft tissues, standardized measurement lines were made based on anatomic landmarks. For consistency among scapulae, measurements were taken at standard percentage intervals along each line approximating the distance between two consecutive reconstruction plate screw holes. Two-mm-diameter drill holes were made at each point, and a standard depth gauge was used to measure thickness. The glenoid fossa (25 mm) displayed the greatest mean osseous thickness, followed by the lateral scapular border (9.7 mm), the scapula spine (8.3 mm), and the central portion of the body of the scapula (3.0 mm). To optimize screw purchase and internal fixation strength, the lateral border, the lateral aspect of the base of the scapula spine, and the scapula spine itself should be used for anatomic sites of internal fixation of scapula fractures.

Methanol Droplet Extinction in Carbon-Dioxide-Enriched Environments in Microgravity

NASA Technical Reports Server (NTRS)

Hicks, Michael C.; Nayagam, Vedha; Williams, Forman A.

2010-01-01

Diffusive extinction of methanol droplets with initial diameters between 1.25 mm and 1.72 mm, burning in a quiescent microgravity environment at one atmosphere pressure, was obtained experimentally for varying levels of ambient carbon-dioxide concentrations with a fixed oxygen concentration of 21% and a balance of nitrogen. These experiments serve as precursors to those which are beginning to be performed on the International Space Station and are motivated by the need to understand the effectiveness of carbon-dioxide as a fire suppressant in low-gravity environments. In these experiments, the flame standoff distance, droplet diameter, and flame radiation are measured as functions of time. The results show that the droplet extinction diameter depends on both the initial droplet diameter and the ambient concentration of carbon dioxide. Increasing the initial droplet diameter leads to an increased extinction diameter, while increasing the carbon-dioxide concentration leads to a slight decrease in the extinction diameter. These results are interpreted using a critical Damk hler number for extinction as predicted by an earlier theory, which is extended here to be applicable in the presence of effects of heat conduction along the droplet support fibers and of the volume occupied by the support beads

Biometric study of the internal dimensions of subglottis and upper trachea in adult Indian population.

PubMed

Prasanna Kumar, S; Ravikumar, A

2014-01-01

The anatomy of the larynx and trachea is well described in literature, however the intraluminal dimensions and contour of the subglottis has not been well documented. Subglottis and trachea are dynamic structures and the internal dimensions and contours have been studied only on cadavers or by plain radiograph which has many technical and measurement errors. No data is available about the internal dimensions of the subglottic and trachea in Indian population. This is the first documented study to measure the dimensions of the trachea and subglottis in Indian population. The aim of this study is to measure the internal dimensions and contour of the subglottis and upper trachea of adult Indian population. We conducted cross-sectional, observational study in a university hospital in south India to measure the dimensions of the internal subglottic and upper tracheal lumen. CT scan with 3D reconstruction with multiplanar sections was used for precise measurements. Forty-eight subjects (30 male and 18 female) who had undergone CT scan of the neck and thorax for reasons other than airway compromise were included in the study. The internal coronal diameter (CD), sagittal diameter (SD), and circumference was measured at various levels from 5 to 70 mm below the level of glottis, in the subglottis and upper trachea. Measurements of the scan for each subject were done independently by a radiologist and ENT surgeon and average of the two were documented values of each subject. These measurements were then statistically analyzed using SSPS software. The mean CD of adult Indian male ranged from 13.18 to 17.68 mm. The average intraluminal circumference ranged from 48.82 mm at the subglottis 5 mm from the glottis to a maximum of 54.96 at 30 mm. The mean CD of adult Indian female ranged from 8.7 to 15.34 mm The average intraluminal circumference ranged from 36.5 at 5 mm and a maximum of 43.05 at 70 mm. The 95% CI for the coronal, sagittal and circumference of the subglottis and upper trachea for both genders have been calculated and discussed. We have observed that the average intraluminal dimensions of the subglottis and upper trachea in south Indian population is less than that reported in western literature and earlier studies.

Rapid surface colony counts determination with three new miniaturised techniques.

PubMed

Malik, K A

1977-01-01

Three different miniaturised methods for the rapid surface viable counting are described. The methods were tried in parallel to seven different existing methods (Table 1) for viable counts and were found to be easier, quicker and insome cases more accurate. The techniques require about 10% of the material and time needed for conventional spread-plates method and the results were in no way inferior to that (Table 1 and 2). Mini agar discs were cut aseptically with an especially designed stainless steel agar disc cutter (25 mm internal and 28 mm external diameter, Fig. 1b) or with a test tube of similar diameter. The area of the resulted mini-agar-disc of 25 mm diameter was kept such (about 1/10th of the normal plate) that the ratio of the colony-bearing area to the inoculm remained the same as on big plates in spread-plate-method (Table 2). In normal Petri dishes (about 90 mm diameter) up to seven mini agar discs were possible to cut. Each small agar disc was seperated from the other mini-disc by a distance of at least 6 mm (Fig. 1a). The empty place around the disc was still enlarged during over drying of the plates and during incubation. This created complete isolation from the neighbouring disc. For micro-determination of surface viable counts 10 micronl from each dilution was delivered on a well-dired mini-disc with a piston micropipette. The inoculm was immediately spread on the whole mini-disc with a specially designed flame sterilizable platinum-Mini-spreader (Fig. 2a). No spinning of the plate was needed. Alternatively the dropping pipette and spreader was replaced by a calibrated platinum wire Loop-spreader (Fig. 2b). A loop of 3 mm internal diameter made from a platinum-iridium wire of 0.75 mm thickness proved most useful and carried a drop of 10 micronl. Differences especially in surface tension of various diluting fluids did not influence to drop of this size and no recalibration was needed for water and nutrient broth. The loop was further shaped to Loop-spreader form. From each bacterial suspension 10 micronl were carried and spread on each mini-disc. The method is useful for pathogenic organisms as the loop can readily be flame sterilized. For routine purposes where only approximate numbers of bacteria need to be known a still rapid semiquantitative method was deviced making use of a calibrated stainless steel Stamping-disc (Fig. 2c). A disc of 25mm diameter and 1 mm thickness delivered approximateyl 10 microlitres of supensions and was found to be most useful to stamp seven dilutions on a single plate. In collections and bacteriology laboratories where by conventional methods large number of plates are to be plated and counted the presented techniques could prove most convenient, rapid and economical.

Diameters of the cavo-sinus-tricuspid area in relation to type I atrial flutter.

PubMed

Kozłowski, Dariusz; Hreczecha, Jolanta; Skwarek, Magdalena; Piwko, Grzegorz; Kosiński, Adam; Gawrysiak, Marcin; Grzybiak, Marek

2003-05-01

Cardiac arrhythmias have troubled patients and fascinated physicians for centuries. The twentieth century was an era of progress, when the mechanism of cardiac disorders became more commonly recognised. Arrhythmias may be due to abnormalities of automaticity, to abnormalities of conduction, or to a combination of both. In order for re-entry to occur, an area of slowing conduction combined with unidirectional block must be present. Much investigation has centred on the underlying re-entry mechanisms of atrial flutter. In the light of these facts, it would seem that a close acquaintance with the detailed topography of the vena cava orifice (cavo), coronary sinus orifice (sinus) and the attachment of the septal leaflet of the tricuspid valve (tricupid) area could be of great interest, especially for invasive cardiologists. The research was conducted carried out on material consisting of 41 hearts of humans of both sexes from the age of 12 to 80 (6 female, 35 male). Classical macroscopic methods of anatomical evaluation were used. The following measurements were made: the shortest distance between the Eustachian valve and the attachment of the tricuspid valve on the left margin of the coronary sinus orifice (diameter 1), the distance between the attachment of the tricuspid valve and the inferior margin of the sinus orifice (diameter 2), the distance between the Eustachian valve and the attachment of the tricuspid valve on the right margin of the coronary sinus orifice (diameter 3), the distance between the inferior margin of the vena cava inferior and the attachment of the tricuspid valve (diameter 4) and, finally, the diameter between the attachment of the septal cusp of the tricuspid valve and the extemal border of the vena cava inferior (diameter 5). No correlation was found between the age and sex of the three groups of the material. The dimensions of the structure examined were similar in the three groups of hearts. In young adult hearts all the diameters measured ranged from 4 to 47 mm. The average diameters were, respectively: 15.02 mm (diameter 1), 8.97 mm (diameter 2), 17.27 mm (diameter 3), 26.87 mm (diameter 4), 36.42 mm (diameter 5). In the mature adult hearts all the diameters measured ranged from 8 to 45 mm; 18.19 mm (diameter 1), 10.54 mm (diameter 2), 19.95 mm (diameter 3), 28.90 mm (diameter 4), 39.63 mm (diameter 5). In the older adults hearts all the diameters measured ranged from 4 to 47 mm. The average diameters were, respectively: 15.65 mm (diameter 1), 8.70 mm (diameter 2), 7.25 mm (diameter 3), 26.80 mm (diameter 4), 35.85 mm (diameter 5). On the basis of our study we were able to conclude that the diameters of the cavo-sinus-tricuspid area were constant and did not differ significantly within the three (young, mature, old) adult groups examined.

Radio-anatomical Study of the Greater Palatine Canal and the Pterygopalatine Fossa in a Lebanese Population: A Consideration for Maxillary Nerve Block

PubMed Central

Aoun, Georges; Nasseh, Ibrahim; Sokhn, Sayde

2016-01-01

Aim: The aim of this study was to describe the morphology of the component, greater palatine canal-pterygopalatine fossa (GPC-PPF), in a Lebanese population using cone-beam computed tomography (CBCT) technology. Materials and Methods: CBCT images of 79 Lebanese adult patients (38 females and 41 males) were included in this study, and a total of 158 cases were evaluated bilaterally. The length and path of the GPCs-PPFs were determined, and the data obtained analyzed statistically. Results: In the sagittal plane, of all the GPCs-PPFs assessed, the average length was 35.02 mm on the right and 35.01 mm on the left. The most common anatomic path consisted in the presence of a curvature resulting in an internal narrowing whose average diameter was 2.4 mm on the right and 2.45 mm on the left. The mean diameter of the upper opening was 5.85 mm on the right and 5.82 mm on the left. As for the lower opening corresponding to the greater palatine foramen, the right and left average diameters were 6.39 mm and 6.42 mm, respectively. Conclusion: Within the limits of this study, we concluded that throughout the Lebanese population, the GPC-PPF path is variable with a predominance of curved one (77.21% [122/158] in both the right and left sides); however, the GPC-PPF length does not significantly vary according to gender and side. PMID:27833777

Change in human lens dimensions, lens refractive index distribution and ciliary body ring diameter with accommodation

PubMed Central

Khan, Adnan; Pope, James M.; Verkicharla, Pavan K.; Suheimat, Marwan; Atchison, David A.

2018-01-01

We investigated changes in ciliary body ring diameter, lens dimensions and lens refractive index distributions with accommodation in young adults. A 3T clinical magnetic resonance imaging scanner imaged right eyes of 38 18-29 year old participants using a multiple spin echo sequence to determine accommodation-induced changes along lens axial and equatorial directions. Accommodation stimuli were approximately 1 D and 5 D. With accommodation, ciliary body ring diameter, and equatorial lens diameter decreased (–0.43 ± 0.31 mm and –0.30 ± 0.23 mm, respectively), and axial lens thickness increased ( + 0.34 ± 0.16 mm). Lens shape changes cause redistribution of the lens internal structure, leading to change in refractive index distribution profiles. With accommodation, in the axial direction refractive index profiles became flatter in the center and steeper near the periphery of the lens, while in the equatorial direction they became steeper in the center and flatter in the periphery. The results suggest that the anatomical accuracy of lens optical models can be improved by accounting for changes in the refractive index profile during accommodation. PMID:29541520

Gender Differences of Airway Dimensions in Anatomically Matched Sites on CT in Smokers

PubMed Central

Kim, Yu-Il; Schroeder, Joyce; Lynch, David; Newell, John; Make, Barry; Friedlander, Adam; Estépar, Raúl San José; Hanania, Nicola A.; Washko, George; Murphy, James R.; Wilson, Carla; Hokanson, John E.; Zach, Jordan; Butterfield, Kiel; Bowler, Russell P.

2013-01-01

Rationale and Objectives There are limited data on, and controversies regarding gender differences in the airway dimensions of smokers. Multi-detector CT (MDCT) images were analyzed to examine whether gender could explain differences in airway dimensions of anatomically matched airways in smokers. Materials and Methods We used VIDA imaging software to analyze MDCT scans from 2047 smokers (M:F, 1021:1026) from the COPDGene® cohort. The airway dimensions were analyzed from segmental to subsubsegmental bronchi. We compared the differences of luminal area, inner diameter, wall thickness, wall area percentage (WA%) for each airway between men and women, and multiple linear regression including covariates (age, gender, body sizes, and other relevant confounding factors) was used to determine the predictors of each airway dimensions. Results Lumen area, internal diameter and wall thickness were smaller for women than men in all measured airway (18.4 vs 22.5 mm2 for segmental bronchial lumen area, 10.4 vs 12.5 mm2 for subsegmental bronchi, 6.5 vs 7.7 mm2 for subsubsegmental bronchi, respectively p < 0.001). However, women had greater WA% in subsegmental and subsubsegmental bronchi. In multivariate regression, gender remained one of the most significant predictors of WA%, lumen area, inner diameter and wall thickness. Conclusion Women smokers have higher WA%, but lower luminal area, internal diameter and airway thickness in anatomically matched airways as measured by CT scan than do male smokers. This difference may explain, in part, gender differences in the prevalence of COPD and airflow limitation. PMID:21756032

Nailfold capillary patterns in healthy subjects: a real issue in capillaroscopy.

PubMed

Ingegnoli, Francesca; Gualtierotti, Roberta; Lubatti, Chiara; Bertolazzi, Chiara; Gutierrez, Marwin; Boracchi, Patrizia; Fornili, Marco; De Angelis, Rossella

2013-11-01

Nailfold capillaroscopy has been extensively applied in a broad spectrum of pathologic conditions, but very few data have been published in healthy individuals. The aim of this study was to describe the nailfold capillary findings on a large series of healthy subjects using the video-capillaroscopy technique. Nailfold capillaries were studied based on their morphology, dimensions and density. Then, to evaluate jointly the association between different capillary findings in groups of subjects which were homogeneous for their characteristics, cluster analysis was performed. The results (median) of capillary measurements were as follows: loop length 207μm, external diameter 39μm, internal diameter 17μm, apical diameter 17μm, and intercapillary distance 143μm. Based on the cluster analysis three major "normal" morphologic capillaroscopic patterns were depicted: 1) the "normal" pattern mainly with 2 to 5 U-shaped loops/mm and ≤2 tortuous loops/mm; 2) the "perfect normal" pattern with ≥5 U-shaped loops/mm and 3) the "unusual normal" with at least 1 meandering or bushy loop, or at least 1 microhemorrhage, or with >4 crossed loops/mm. Regarding the loop measurements, the majority of subjects had a median of 7capillaries/mm with a median length of 198μm. © 2013 Elsevier Inc. All rights reserved.

Anatomical dimensions of trachea, main bronchi, subcarinal and bronchial angles in fetuses measured ex vivo.

PubMed

Harjeet; Sahni, Daisy; Batra, Yatindra Kumar; Rajeev, Subramanyam

2008-11-01

The increasing opportunities to consider fetal intervention in selected cases of life-threatening malformations have necessitated airway management of fetuses with low gestational age. This study is aimed to determine the anatomical dimensions of trachea, main bronchi, subcarinal and bronchial angles and their correlation to age and crown rump length (CRL) in fetuses. Measurements of tracheo-bronchial dimensions including the subcarinal and bronchial angles with the vertical were taken in specimens obtained from 40 fetuses, varying in CRL from 61 to 270 mm. The incidence of different shapes at the upper end of trachea was studied. The subcarinal and angles of main bronchi with the vertical were measured radiographically with 20% barium sulfate, in another group of 21 fetuses varying in CRL from 63 to 129 mm. Forty fetuses (22 males, 18 females) were analyzed for the dimensions based on CRL (61-130 mm; 131-200 mm; 201-270 mm--CRL 1, 2, and 3 respectively). The internal transverse diameter of trachea was found to increase steadily from 1.87 +/- 0.56 to 2.67 +/- 0.7 mm (P < 0.001) and 3.68 +/- 0.39 mm (P < 0.001) with increasing CRL. Similarly the outer transverse and antero-posterior diameter of the trachea increased steadily with age. Tracheal length was found to increase significantly to 17.48 +/- 2.89 mm and 24.17 +/- 2.3 from 12.72 +/- 2.5 mm (P < 0.001). The length of paries membranaceous increased with gestational age. Although the length of bronchi increased significantly and linearly, subcarinal and bronchial angles did not show any significant changes with age. There was no sexual dimorphism in measurements in the fetuses of corresponding CRL. Oval shaped trachea was found in 60% and circular in 40% of fetuses. The measurements of subcarinal and bronchial angles performed by radiology were almost the same as those measured in trachea separated from fetuses. The internal transverse, outer transverse and antero-posterior diameters, length of trachea and bronchi and circumference of trachea, relate in a linear fashion to CRL and age. However, subcarinal and bronchial angles remained constant.

Measurements from preterm infants to guide face mask size.

PubMed

O'Shea, Joyce E; Thio, Marta; Owen, Louise S; Wong, Connie; Dawson, Jennifer A; Davis, Peter G

2016-07-01

International guidelines recommend that an appropriately sized face mask for providing positive pressure ventilation should cover the mouth and nose but not the eyes and should not overlap the chin. This study aimed to measure the dimensions of preterm infants' faces and compare these with the size of the most commonly available face masks (external diameter 50 mm) and the smallest masks available (external diameters 35 and 42 mm). Infants 24-33 weeks' postmenstrual age (PMA) were photographed in a standardised manner. Images were analysed using ImageJ software (National Institute of Health, USA) to calculate the distance from the nasofrontal groove to the mental protuberance. This facial measurement corresponds to the external diameter of an optimally fitting mask. A cohort of 107 infants between 24 and 33 weeks' gestational age, including at least 10 infants per week of gestation, was photographed within 72 h after birth and weekly until 33 weeks' PMA. 347 photographs were analysed. Infants of 24, 26, 28, 30 and 32 weeks' PMA had mean (SD) facial measurements of 32 (2), 36 (3), 38 (4), 41 (2) and 43 (4) mm, respectively. There were no significant differences when examined by gender or when small for gestational age infants were excluded. The smallest size of some brands of mask is too large for many preterm infants. Masks of 35 mm diameter are suitable for infants <29 weeks' PMA or 1000 g. Masks of 42 mm diameter are suitable for infants 27-33 weeks' PMA or 750-2500 g. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

An experimental investigation of the cooling channel geometry effects on the internal forced convection of liquid methane

NASA Astrophysics Data System (ADS)

Trejo, Adrian

Rocket engine fuel alternatives have been an area of discussion for use in high performance engines and deep spaceflight missions. In particular, LCH4 has showed promise as an alternative option in regeneratively cooled rocket engines due to its non-toxic nature, similar storage temperatures to liquid oxygen, and its potential as an in situ resource. However, data pertaining to the heat transfer characteristics of LCH4 is limited. For this reason, a High Heat Transfer Test Facility (HHTTF) at the University of Texas at El Paso's (UTEP) Center for Space Exploration Technology and Research has been developed for the purpose of flowing LCH4 through several heated tube geometry designs subjected to a constant heat flux. In addition, a Methane Condensing Unit (MCU) is integrated to the system setup to supply LCH4 to the test facility. Through the use of temperature and pressure measurements, this experiment will serve not only to study the heat transfer characteristics of LCH4; it serves as a method of simulating the cooling channels of a regeneratively cooled rocket engine at a subscale level. The cross sections for the cooling channels investigated are a 1.8 mm x 1.8 mm square channel, 1.8 mm x 4.1 mm rectangular channel, 3.2 mm and 6.34 mm inside diameter channel, and a 1.8 mm x 14.2 mm high aspect ratio cooling channel (HARCC). The test facility is currently designed for test pressures between 1.03 MPa to 2.06 MPa and heat fluxes up to 5 MW/m2. Results show that at the given test pressures, the Reynolds number reaches up to 140,000 for smaller cooling channels (3.2 mm diameter tube and 1.8 mm x 4.1 mm rectangle) while larger cooling channel geometries (6.35 mm diameter and HARCC) reached Reynolds number around 70,000. Nusselt numbers reached as high as 320 and 265 for a 3.2 mm diameter tube and 1.8 mm x 4.1 mm rectangular channel respectively. For cooling channel geometries with 6.35 mm diameter and HARCC geometry, Nusselt numbers reached 136 (excluding an outlier) and 106 respectively. Heat transfer predictions applied to the data yielded theoretical correlations within 40% of the experimental data. However, typical theoretical values fall within 10%-15% of the experimental values showing agreeable correlations and supporting theories stated in the present study.

Clinical effect of pancreaticojejunostomy with a long-internal stent during pancreaticoduodenectomy in patients with a main pancreatic duct of small diameter.

PubMed

Yamamoto, Tomohisa; Satoi, Sohei; Yanagimoto, Hiroaki; Hirooka, Satoshi; Yamaki, So; Ryota, Hironori; Kotsuka, Masaya; Matsui, Yoichi; Kon, Masanori

2017-06-01

Post-operative pancreatic fistula (POPF) is one of the most common causes of death following pancreaticoduodenectomy (PD). The aim of this study was to evaluate the clinical effect of a long-internal stent on the development of POPF in patients with a main pancreatic duct diameter of 3 mm or less. Patients (N = 108) with a main pancreatic duct (≤3 mm) who underwent PD were included in this single-institution historical control study. Between January 2012 and December 2013, 54 patients had undergone PJ with a long-internal stent across the duct-to-mucosa anastomosis (long-stent group), and between February 2009 and December 2011, 54 patients had undergone PJ without a stent (control). There was no significant difference between groups (long-stent vs control) in the incidence of POPF (70% vs. 56%, p = 0.110) and grade B/C POPF (26% vs. 26%, p = 1.000). Univariate analysis identified body mass index, extent of blood loss and soft pancreatic parenchyma as risk factors related to POPF. Multivariate analysis identified extent of blood loss and soft pancreatic parenchyma as significant risk factors. Placement of a long-internal stent during PJ did not reduce POPF after PD in patients with a main pancreatic duct of small diameter. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Evaluation de l'effet structurel de l'impact d'un micrometeorite ou d'un debris orbital sur le bras Canadien 2

NASA Astrophysics Data System (ADS)

Lanouette, Anne-Marie

Space structures are more and more likely to be impacted at hypervelocities, velocities greater than 3km/s, as the number of orbital debris has rapidly grown in the last two decades. These debris are mostly composed of pieces jettisoned from a launcher or a satellite during the deployment of a structure, dead spacecrafts and fragmentation debris. Collision between two debris, generating many smaller new debris, are more likely to happen. Large space debris (diameter over 10cm) are tracked by different space organizations and their position at all time is known. It is however impossible to track the smaller debris while several studies have already demonstrated that they can also cause significant damage to structures. It is now more and more common to add a kind of protection against collisions to the space structures, but the great majority of space structures currently in orbit, as the Canadarm2, are not protected against hypervelocity impacts. Damage caused by such impacts to different space materials such as aluminum, sandwich panels and laminates has already been characterized during different studies since the end of the 1980s while no study, dedicated to the experimental evaluation of the mechanical properties of a space structure after an impact, relevant to the case of the Canadarm2, has been published. It is only possible to find, in the literature, studies determining the residual mechanical properties after an impact at much lower velocities; the energy of impact is generally three orders of magnitude smaller. The Canadarm2, or Space Station Remote Manipulator System (SSRMS), is installed on the International Space Station (ISS) since 2001. It had an initial 10-year lifespan, but it is still very useful today for maintenance operations and to capture and release incoming space capsules. Understanding the effects of an orbital debris impact on the Canadarm2 structure is now primordial in order to adequately redefine the load levels that can be applied on the arm as a function of the observable damage on the thermal blankets. The main objectives of this study are: first, to obtain a correlation between the visible damage on the booms and the corresponding internal damage of the structure, second to study the cracks caused by the impact growth under different cyclic loads, and finally to provide considerations on the load levels to be applied on the robotic arm as a function of the observable damage. To achieve these objectives, samples representative of the Canadarm2 structure, four cylindrical samples of carbon fibers IM7/PEEK with an external diameter of 35cm and a thickness of 2.7mm, were obtained and covered by pieces of thermal blankets also representative of the Canadarm2. These four samples were impacted at the University of New Brunswick hypervelocity facility, HIT Dynamics. Two samples were impacted by projectiles 5.556mm in diameter and the two remaining samples were impacted with 7.938mm in diameter projectiles. All projectiles were aluminum spheres travelling at ˜7km/s. The samples underwent ultrasonic scanning thereafter to obtain images of their internal damage. In the case of the 5.556mm diameter projectiles, the damage left on the front side was an entry crater 6.2cm in diameter on the thermal blanket and a crater 14.8mm in diameter on the composite wall accompanied by no visual damage on the opposite side of the cylinder. In the case of the 7.938mm diameter projectiles, the damage left on the front side was an entry crater 9.2cm in diameter on the thermal blanket and a crater 17.0mm in diameter on the composite wall accompanied by visible damage on the opposite side in a zone 25.5cm in diameter. The suggestions given for the utilization of the Canadarm2 after an impact are thus the followings. If a crater ≤ 14mm on the composite wall is visible on one side accompanied by no damage on the opposite side of the structure, then the flight and emergency load levels can be maintained. However, if a crater ≤ 17.0mm on the composite wall is visible on one side accompanied by damage in a zone ≤ 25.5cm on the opposite side of the cylinder, only the flight load level can still be used for any position of the damaged zones. If the emergency level must be used, then the damaged zones must absolutely be positioned close to the bending neutral plan, otherwise the applied loads will aggravate the damage caused by the orbital debris impact. (Abstract shortened by ProQuest.).

Three-Dimensional Finite Element Analysis of Varying Diameter and Connection Type in Implants with High Crown-Implant Ratio.

PubMed

Moraes, Sandra Lúcia Dantas de; Verri, Fellippo Ramos; Santiago, Joel Ferreira; Almeida, Daniel Augusto de Faria; Lemos, Cleidiel Aparecido Araujo; Gomes, Jéssica Marcela de Luna; Pellizzer, Eduardo Piza

2018-01-01

The aim of this study was to evaluate the effect of varying the diameter, connection type and loading on stress distribution in the cortical bone for implants with a high crown-implant ratio. Six 3D models were simulated with the InVesalius, Rhinoceros 3D 4.0 and SolidWorks 2011 software programs. Models were composed of bone from the posterior mandibular region; they included an implant of 8.5 mm length, diameter Ø 3.75 mm or Ø 5.00 mm and connection types such as external hexagon (EH), internal hexagon (IH) and Morse taper (MT). Models were processed using the Femap 11.2 and NeiNastran 11.0 programs and by using an axial force of 200 N and oblique force of 100 N. Results were recorded in terms of the maximum principal stress. Oblique loading showed high stress in the cortical bone compared to that shown by axial loading. The results showed that implants with a wide diameter showed more favorable stress distribution in the cortical bone region than regular diameter, regardless of the connection type. Morse taper implants showed better stress distribution compared to other connection types, especially in the oblique loading. Thus, oblique loading showed higher stress concentration in cortical bone tissue when compared with axial loading. Wide diameter implant was favorable for improved stress distribution in the cortical bone region, while Morse taper implants showed lower stress concentration than other connections.

The effect of glenosphere diameter in reverse shoulder arthroplasty on muscle force, joint load, and range of motion.

PubMed

Langohr, G Daniel G; Giles, Joshua W; Athwal, George S; Johnson, James A

2015-06-01

Little is known about the effects of glenosphere diameter on shoulder joint loads. The purpose of this biomechanical study was to investigate the effects of glenosphere diameter on joint load, load angle, and total deltoid force required for active abduction and range of motion in internal/external rotation and abduction. A custom, instrumented reverse shoulder arthroplasty implant system capable of measuring joint load and varying glenosphere diameter (38 and 42 mm) and glenoid offset (neutral and lateral) was implanted in 6 cadaveric shoulders to provide at least 80% power for all variables. A shoulder motion simulator was used to produce active glenohumeral and scapulothoracic motion. All implant configurations were tested with active and passive motion with joint kinematics, loads, and moments recorded. At neutral and lateralized glenosphere positions, increasing diameter significantly increased joint load (+12 ± 21 N and +6 ± 9 N; P < .01) and deltoid load required for active abduction (+9 ± 22 N and +11 ± 15 N; P < .02), whereas joint load angle was unaffected (P > .8). Passive internal rotation was reduced with increased diameter at both neutral and lateralized glenosphere positions (-6° ± 6° and -12° ± 6°; P < .002); however, external rotation was not affected (P > .05). At neutral glenosphere position, increasing diameter increased the maximum angles of both adduction (+1° ± 1°; P = .03) and abduction (+8° ± 9°; P < .05). Lateralization also increased abduction range of motion compared with neutral (P < .01). Although increasing glenosphere diameter significantly increased joint load and deltoid force, the clinical impact of these changes is presently unclear. Internal rotation, however, was reduced, which contradicts previous bone modeling studies, which we postulate is due to increased posterior capsular tension as it is forced to wrap around a larger 42 mm implant assembly. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

A new device for slow progressive narrowing of vessels.

PubMed

Lange, P E; Sievers, H H; Nürnberg, J H; Engler, K; Pilarczyk, J; Onnasch, D G; Bernhard, A; Heintzen, P H

1985-01-01

The purpose of this work was to develop a device which allows slow progressive banding of a great artery in infants within 4 to 5 weeks. Employed was the hygroscopic casein ameroid. When brought in contact with fluids, an ameroid cylinder expands characteristically. An early phase of fast expansion proceeds gradually to a phase of slow growth. Size, shape, and encasement of ameroid as well as temperature and type of surrounding fluid modify but do not alter the typical pattern of expansion. The developed constrictor (weight: 5.8 kg, length: 18 mm, diameter: 12 mm) includes a stainless steel socket containing an ameroid cylinder (length: 8.5 mm, diameter: 8 mm). The expanding ameroid pushes a piston with a concave extension (makrolon) a maximum of 2 mm against the artery, which is fixed to the metal housing by a teflon band (width: 4 mm, thickness: 0.5 mm). The band runs in 2 fitting grooves on the metal housing to which it is fixed by a metal ring with a precisely manufactured internal thread allowing exact tightening and loosening of the band around the artery. Utilization of inert materials like teflon, makrolon, and stainless steel warrants experimental and possibly clinical application of the developed small constrictor.

Preoperative ultrasonographic evaluation of the contralateral patent processus vaginalis at the level of the internal inguinal ring is useful for predicting contralateral inguinal hernias in children: a prospective analysis.

PubMed

Kaneda, H; Furuya, T; Sugito, K; Goto, S; Kawashima, H; Inoue, M; Hosoda, T; Masuko, T; Ohashi, K; Ikeda, T; Koshinaga, T; Hoshino, M; Goto, H

2015-08-01

The current study aimed to verify the usefulness of preoperative ultrasonographic evaluation of contralateral patent processus vaginalis (PPV) at the level of the internal inguinal ring. This was a prospective study of patients undergoing unilateral inguinal hernia repair at two institutions during 2010-2011. The sex, age at initial operation, birth weight, initial operation side, and the preoperative diameter of the contralateral PPV as determined using ultrasonography (US) were recorded. We analyzed the incidence of contralateral inguinal hernia, risk factors, and the usefulness of the preoperative major diameter of the contralateral PPV. The follow-up period was 36 months. All 105 patients who underwent unilateral hernia repair completed 36 months of follow-up, during which 11 patients (10.5 %) developed a contralateral hernia. The following covariates were not associated with contralateral hernia development: sex (p = 0.350), age (p = 0.185), birth weight (p = 0.939), and initial operation side (p = 0.350). The preoperative major diameter of the contralateral PPV determined using US was significantly wider among patients with a contralateral hernia than those without a contralateral hernia (p = 0.001). When the 105 patients were divided into two groups according to cut-off values of the preoperative major diameter of the contralateral PPV (wide group, >2.0 mm; narrow group, ≤2.0 mm), a significant association was observed between the preoperative major diameter of the contralateral PPV and patient outcomes (p = 0.001). We used US and confirmed the usefulness of a preoperative evaluation of the major diameter of the contralateral PPV at the level of the internal inguinal ring in pediatric patients with unilateral inguinal hernias.

Thermal evaluation by infrared measurement of implant site preparation between single and gradual drilling in artificial bone blocks of different densities.

PubMed

Möhlhenrich, S C; Abouridouane, M; Heussen, N; Hölzle, F; Klocke, F; Modabber, A

2016-11-01

The aim of this study was to investigate the influence of bone density and drilling protocol on heat generation during implant bed preparation. Ten single and 10 gradual implant sites with diameters of 2.8, 3.5, and 4.2mm were prepared in four artificial bone blocks (density types I-IV; D1-D4). Drilling was done at constant speed (1500rpm) and with external irrigation (50ml/min); vertical speed was set at 2mm/s. An infrared camera was used for temperature measurements. Significantly higher temperatures for single drilling were found between 2.8-mm drills in D1 (P=0.0014) and D4 (P<0.0001) and between 3.5-mm drills in D3 (P=0.0087) and D4 (P<0.0001), as well as between 4.2-mm drills in D1 (P<0.0001) and D4 (P=0.0014). Low bone density led to a thermal decrease after single drilling and a thermal increase after gradual drilling. Burs with a large diameter always showed a higher temperature generation. In comparisons between 2.8- and 4.2-mm diameters for both single and gradual drills, significant differences (P<0.001) were noted for bone types II, III, and IV. Single drilling could generate more heat than traditional sequential drilling, and bone density, as well as drill diameter, influenced thermal increases. Particularly in lower-density bone, conventional sequential drilling seems to raise the temperature less. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Morphological Differences in the Aorto-iliac Segment in AAA Patients of Caucasian and Asian Origin.

PubMed

Banzic, I; Lu, Q; Zhang, L; Stepak, H; Davidovic, L; Oszkinis, G; Mladenovic, A; Markovic, M; Rancic, Z; Jing, Z; Brankovic, M

2016-06-01

The objective was to quantify aorto-iliac morphology differences between AAA patients of Caucasian and Asian origin. Additionally, the impact of patient demographic characteristics was assessed, which could influence the morphological differences. This international multicentre study included two tertiary referral institutions from Europe and one from China. CT scans with 3D reconstruction of 296 patients with infrarenal AAA >5 cm were analysed. Eighteen measurements were recorded from each CT scan and compared between Caucasian and Asian patients. Caucasian patients had longer common iliac arteries (right: 65.0 vs. 33.1 mm, p < .001 left: 65.0 vs. 35.2 mm, p < .001), longer aneurysm neck (33.0 vs. 28.4 mm, p < .001), greater aneurysm to aortic axis angle (153.0° vs. 142.2°, p < .001), and longer combined aorto-iliac length (195.7 vs. 189.2 mm, p < .001). However, Asian patients had a longer infrarenal abdominal aorta (152.0 vs. 130.0 mm, p < .001), longer AAA (126.2 vs. 93.0 mm), and greater linear distance from renal artery to aorto-iliac bifurcation (143.6 vs. 116.0 mm, p < .001). Caucasian patients had a larger inner common iliac artery diameter (right: 16.0 vs. 14.9 mm, p < .001, left: 16.0 vs. 15.2 mm, p < .001), larger inner exernal iliac artery diameter (right: 9.0 vs. 7.5 mm, p < .001 left: 9.0 vs. 7.7 mm, p < .001), and larger inner common femoral artery diameter (right: 10.0 vs. 5.9 mm, p < .001 left: 10.0 vs. 6.1 mm, p < .001). No difference was observed in AAA transverse diameter (62.0 vs. 63.1 mm, p = .492). The results showed that aorto-iliac anatomy in Caucasians differs significantly from Asians, particularly in the length of the common iliac arteries and infrarenal abdominal aorta, and in the transverse diameter of the common, external iliac, and common femoral arteries. Therefore, the exact criteria for stent graft design are dependent on the racial origin of the patient. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Computational modeling of HHH therapy and impact of blood pressure and hematocrit.

PubMed

Robinson, Joe Sam; Walid, M Sami; Hyun, Sinjae; O'Connell, Robert; Menard, Chris; Bohleber, Brandi

2010-01-01

After an aneurysmal subarachnoid hemorrhage, cerebral microcirculatory changes occur as a result cerebral vasospasm. The objective of this study is to investigate, with a computational model, how various degrees of vasospasm are influenced by increasing the mean blood pressure and decreasing the blood viscosity. Using ANSYS CFX software, a computational model was constructed to simulate steady-state fully developed laminar blood flow through a rigid wall system consisting of the internal carotid artery (ICA), anterior cerebral artery, posterior cerebral artery, and middle cerebral artery (MCA). The MCA was selected for the site of a single acute vasospasm. Five severities of vasospasm were studied: 3 mm (normal), 2.5, 2, 1.5, and 1 mm. The ICA was assumed to have a constant inlet flow rate of 315 mL/min. The anterior cerebral artery and posterior cerebral artery were assumed to have constant outlet flow rates of 105 mL/min and 30 mL/min, respectively. The MCA was assumed to have a constant outlet pressure of 92 mL/min. Two different hematocrits, 45% and 32%, were simulated using the models. For a hematocrit of 45, the mean ICA inlet pressure required to pump blood through the system was 104 mm Hg for the 3-mm diameter MCA and 105, 108, 116, and 158 mm Hg for vasospasm diameters of 2.5, 2, 1.5, and 1 mm, respectively. For a hematocrit of 32, the mean ICA inlet pressure required was 102, 103, 105, 113, and 152 mm Hg, respectively. The MCA required a large increase in mean ICA inlet pressure for vasospasm diameters less than 1.5 mm, which suggests that for vasospasms more than 50% diameter reduction, the blood pressure must be increased dramatically. Decreasing the hematocrit had minimal impact on blood flow in a constricted vessel. Copyright © 2010 Elsevier Inc. All rights reserved.

The influence of cervical finish line, internal relief, and cement type on the cervical adaptation of metal crowns.

PubMed

Bottino, Marco Antonio; Valandro, Luiz Felipe; Buso, Leonardo; Ozcan, Mutlu

2007-01-01

The aim of this investigation was to evaluate the cervical adaptation of metal crowns under several conditions, namely (1) variations in the cervical finish line of the preparation, (2) application of internal relief inside the crowns, and (3) cementation using different luting materials. One hundred eighty stainless-steel master dies were prepared simulating full crown preparations: 60 in chamfer (CH), 60 in 135-degree shoulder (OB), and 60 in rounded shoulder (OR). The finish lines were machined at approximate dimensions of a molar tooth preparation (height: 5.5 mm; cervical diameter: 8 mm; occlusal diameter: 6.4 mm; taper degree: 6; and cervical finish line width: 0.8 mm). One hundred eighty corresponding copings with the same finish lines were fabricated. A 30-Microm internal relief was machined 0.5 mm above the cervical finish line in 90 of these copings. The fit of the die and the coping was measured from all specimens (L0) prior to cementation using an optical microscope. After manipulation of the 3 types of cements (zinc phosphate, glass-ionomer, and resin cement), the coping was luted on the corresponding standard master die under 5-kgf loading for 4 minutes. Vertical discrepancy was again measured (L1), and the difference between L1 and L0 indicated the cervical adaptation. Significant influence of the finish line, cement type, and internal relief was observed on the cervical adaptation (P <.001). The CH type of cervical finish line resulted in the best cervical adaptation of the metal crowns regardless of the cement type either with or without internal relief (36.6 +/- 3 to 100.8 +/- 4 Microm) (3-way analysis of variance and Tukey's test, a = .05). The use of glass-ionomer cement resulted in the least cervical discrepancy (36.6 +/- 3 to 115 +/- 4 Microm) than those of other cements (45.2 +/- 4 to 130.3 +/- 2 Microm) in all conditions. The best cervical adaptation was achieved with the chamfer type of finish line. The internal relief improved the marginal adaptation significantly, and the glass-ionomer cement led to the best cervical adaptation, followed by zinc phosphate and resin cement.

A Score to Identify Patients with Brain Metastases from Colorectal Cancer Who May Benefit from Whole-brain Radiotherapy in Addition to Stereotactic Radiosurgery/Radiotherapy.

PubMed

Rades, Dirk; Dziggel, Liesa; Blanck, Oliver; Gebauer, Niklas; Bartscht, Tobias; Schild, Steven E

2018-05-01

To design a tool to predict the probability of new cerebral lesions after stereotactic radiosurgery/radiotherapy for patients with 1-3 brain metastases from colorectal cancer. In 21 patients, nine factors were evaluated for freedom from new brain metastases, namely age, gender, Karnofsky performance score (KPS), tumor type, number, maximum total diameter of all lesions and sites of cerebral lesions, extra-cranial metastases, and time from cancer diagnosis to irradiation. Freedom from new lesions was positively associated with KPS of 90-100 (p=0.013); maximum total diameter ≤15 mm showed a trend for positive association (p=0.09). Points were assigned as: KPS 70-80=1 point, KPS 90-100=2 points, maximum diameter ≤15 mm=2 points and maximum diameter >15 mm=1 point. Six-month rates of freedom from new lesions were 29%, 45% and 100% for those with total scores of 2, 3 and 4 points, respectively, with corresponding 12-month rates of 0%, 45% and 100% (p=0.027). This study identified three risk groups regarding new brain metastases after stereotactic irradiation. Patients with 2 points could benefit from additional whole-brain radiotherapy. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Development of tissue-engineered self-expandable aortic stent grafts (Bio stent grafts) using in-body tissue architecture technology in beagles.

PubMed

Kawajiri, Hidetake; Mizuno, Takeshi; Moriwaki, Takeshi; Ishibashi-Ueda, Hatsue; Yamanami, Masashi; Kanda, Keiichi; Yaku, Hitoshi; Nakayama, Yasuhide

2015-02-01

In this study, we aimed to describe the development of tissue-engineered self-expandable aortic stent grafts (Bio stent graft) using in-body tissue architecture technology in beagles and to determine its mechanical and histological properties. The preparation mold was assembled by insertion of an acryl rod (outer diameter, 8.6 mm; length, 40 mm) into a self-expanding nitinol stent (internal diameter, 9.0 mm; length, 35 mm). The molds (n = 6) were embedded into the subcutaneous pouches of three beagles for 4 weeks. After harvesting and removing each rod, the excessive fragile tissue connected around the molds was trimmed, and thus tubular autologous connective tissues with the stent were obtained for use as Bio stent grafts (outer diameter, approximately 9.3 mm in all molds). The stent strut was completely surrounded by the dense collagenous membrane (thickness, ∼150 µm). The Bio stent graft luminal surface was extremely flat and smooth. The graft wall of the Bio stent graft possessed an elastic modulus that was almost two times higher than that of the native beagle abdominal aorta. This Bio stent graft is expected to exhibit excellent biocompatibility after being implanted in the aorta, which may reduce the risk of type 1 endoleaks or migration. © 2014 Wiley Periodicals, Inc.

Half-peroneus-longus-tendon graft augmentation for unqualified hamstring tendon graft of anterior cruciate ligament reconstruction.

PubMed

Liu, Chung-Ting; Lu, Yung-Chang; Huang, Chang-Hung

2015-09-01

In some situations, harvested hamstring tendon grafts are not qualified for anterior cruciate ligament (ACL) reconstruction. This study aimed to present a reinforcing method with additional half peroneus longus tendon (half-PLT) graft augmentation. Eight cases underwent ACL reconstruction with unqualified hamstring tendon grafts (diameter <7 mm) and were salvaged by additional half-PLT graft augmentation. The pivot shift test and KT-1000 tests were performed 3 years after surgery. Functional evaluation of subjective International Knee Documentation Committee (IKDC) and Lysholm scores was also done. In addition, Foot and Ankle Disability Index (FADI) scores were used to evaluate the function of the ankle donor site. The diameter of unqualified four-strand hamstring tendon grafts was 6.2 mm on average (range, 6.0-6.5 mm). The average diameter of hamstring grafts with half-PLT augmentation was 9.6 mm (range, 9.5-10.0 mm). The pivot shift test was negative in all patients. No significant differences between normal and abnormal knees were found by KT-1000. The average IKDC score was 86.0 (range, 83 to 89), and the average Lysholm score was 84.4 (range, 80-90). The average FADI score for the donor sites of half-PLT was 135.8 (range, 134-136). Additional half-PLT can successfully and safely reinforce unqualified hamstring tendon grafts for ACL reconstruction.

Internal Diameter HVAF Spraying for Wear and Corrosion Applications

NASA Astrophysics Data System (ADS)

Lyphout, C.; Björklund, S.

2015-01-01

Electrolytic hard chrome (EHC) methods are still widely utilized in the printing, automotive and off-shore industries. Alternative methods to EHC have been widely developed in the past decade by conventional HVOF processes and more recently HVAF systems, which are processing at higher kinetic energy and more particularly at lower temperature, significantly increasing wear and corrosion resistance properties. A dedicated internal diameter HVAF system is here presented, and coatings characteristics are compared to the one obtained by standard HVAF coatings. Specially R&D designed fixtures with inside bore of 200 mm have been manufactured for this purpose, with a possibility to spray samples at increasing depth up to 400 mm while simulating closed bottom bore spraying. WC-based and Cr3C2-based powder feedstock materials have been deposited onto high-strength steel substrates. Respective coating microstructures, thermally induced stresses and corrosion resistance are discussed for further optimization of coating performances. The fact that the ID-HVAF system is utilized both for spraying and gritblasting procedures is also given a particular interest.

[Dynamic forces of Mitkovic self-dinamysible trochanteric Internal fixators (SIF)].

PubMed

Mitković, Milan M; Manić, Miodrag T; Petković, Dusan Lj; Milenković, Sasa S; Mitković, Milorad B

2013-01-01

Dynamic trochanteric fractures implants allow fracture fragments to be compressed. Dynamisation can be realized if the axial pin force overcome friction force between pin and body of the implant. Examination of sliding iniciation forces in Mitkovic Selfdinamysible Trochanteric Internal Fixator (SIF). SIF was attached for angle block in the position with vertical orientation of pins. The transversal load of 5 kg was connected to pins by a rope. A dynamometer was used to measure force during the movement of angle block in up direction. Regression coefficients were a1 = 4,052 i b1 = 0,623 for SIF with 2 sliding screws with diameter of 7mm and a2 = 4,534 i b2 = 0,422 for SIF with 1 screw with diameter of 10 mm. Coefficients of determination were: r12 = 0,470 and r22 = 0,123. Sliding of SIF pins can be achieved for each analysed body weight of patient (50-130 kg). Early bearing of operated leg is significant for sliding initiation of SIF sliding screws.

[Microsurgical anatomy importance of A1-anterior communicating artery complex].

PubMed

Monroy-Sosa, Alejandro; Pérez-Cruz, Julio César; Reyes-Soto, Gervith; Delgado-Hernández, Carlos; Macías-Duvignau, Mario Alberto; Delgado-Reyes, Luis

2013-01-01

The anterior cerebral artery originates from the bifurcation of the internal carotid artery lateral to the optic chiasm, then joins with its contralateral counterpart via the anterior communicating artery. A1-anterior communicating artery complex is the most frequent anatomical variants and is the major site of aneurysms between 30 to 37%. Know the anatomy microsurgical, variants anatomical and importance of complex precommunicating segment-artery anterior communicating in surgery neurological of the pathology vascular, mainly aneurysms, in Mexican population. The study was performed in 30 brains injected. Microanatomy was studied (length and diameter) of A1-anterior communicating artery complex and its variants. 60 segments A1, the average length of left side was 11.35 mm and 11.84 mm was right. The average diameter of left was 1.67 mm and the right was 1.64 mm. The average number of perforators on the left side was 7.9 and the right side was 7.5. Anterior communicating artery was found in 29 brains of the optic chiasm, its course depended on the length of the A1 segment. The average length of the segment was 2.84 mm, the average diameter was 1.41 mm and the average number of perforators was 3.27. A1-anterior communicating artery complex variants were found in 18 (60%) and the presence of two blister-like aneurysms. It is necessary to understand the A1-anterior communicating artery complex microanatomy of its variants to have a three-dimensional vision during aneurysm surgery.

Thermal performance comparison of oscillating heat pipes with and without helical micro-grooves

NASA Astrophysics Data System (ADS)

Qu, Jian; Li, Xiaojun; Xu, Qian; Wang, Qian

2017-11-01

This paper presents an experimental investigation to compare the thermal performance of three closed loop oscillating heat pipes (OHPs) with and without internal helical microgrooves at vertical and horizontal orientations. All of these OHPs were made from copper tubes and have three turns with lengths of 70, 230 and 110 mm at the evaporator, adiabatic and condenser sections, respectively. Deionized water was used as the working fluid at a volumetric filling ratio of 50%. The internal diameters (IDs) of two smooth-tube OHPs are 4.0 and 4.8 mm, respectively, and the internal diameter of micro-grooved OHP without groove structures is about 4.5 mm. Experimental results demonstrated that the addition of groove structures make the OHP remarkably outperform smooth-tube OHPs in both effective thermal conductivity and thermal resistance. The thermal resistance of vertically-oriented micro-grooved OHP could be lowered to 0.057 °C/W associated with an effective thermal conductivity of 6.1 × 104 W/ (m·K) at the input heat flux of 3.8 × 104 W/m2. Compared to smooth-tube OHPs, preliminary mechanism analysis reveals that local heat transfer coefficients both at the heating and cooling sections of micro-grooved OHP could be significantly improved. Moreover, enhanced liquid backflow to the evaporator due to microgroove-induced capillarity is also responsible for the OHP performance enhancement.

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2013 CFR

2013-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2011 CFR

2011-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2014 CFR

2014-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

33 CFR Appendix A to Part 155 - Specifications for Shore Connection

Code of Federal Regulations, 2012 CFR

2012-07-01

... of this part] Item Description Dimension 1 Outside diameter 215 mm. (8 in.). 2 Inside diameter According to pipe outside diameter. 3 Bolt circle diameter 183 mm. (7 3/16 in.). 4 Slots in flange 6 holes 22 mm. (7/8 in.) in diameter shall be equidistantly placed on a bolt circle of the above diameter...

Influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers fed on wheat-based diets.

PubMed

Abdollahi, M R; Ravindran, V; Wester, T J; Ravindran, G; Thomas, D V

2013-06-01

1. The influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers given wheat-based diets was examined from 10 to 42 d of age. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two pellet diameters (3 and 4.76 mm) and two pellet lengths (3 and 6 mm). From 0 to 9 d of age, all birds were offered a common starter diet pelleted with a 3-mm diameter die and 3-mm length. Broiler grower (d 10 to 21) and finisher (d 22 to 42) diets, based on wheat, were formulated and then subjected to the 4 different treatments. 2. In grower diets, increasing pellet diameter and pellet length reduced the gelatinised starch (GS) content of the diets. In finisher diets, GS content of 3-mm diameter pellets did not change with increasing pellet length but decreased in 4.76-mm diameter pellets. 3. In grower and finisher diets, increments in intact pellet weight, pellet durability index and pellet hardness with increasing pellet length were greater in 3-mm diameter pellets than those with 4.76-mm diameter. 4. Increasing pellet length from 3 to 6 mm increased apparent metabolisable energy values. Neither the interaction nor main effects were significant for the ileal digestibility of nitrogen and starch. 5. During the grower period (d 10 to 21), birds given pellets of 6-mm length had greater body-weight gain than those given 3-mm length pellets. Feeding 6-mm length pellets decreased feed per body-weight gain compared to 3-mm length pellets. During the finisher (d 22 to 42) and whole grow-out (d 10 to 42) periods, while different pellet lengths had no effect on feed per body-weight gain values at 3-mm pellet diameter, increasing the pellet length decreased feed per body-weight gain at 4.76-mm pellet diameter. 6. Increasing pellet diameter and pellet length reduced the relative length of duodenum. Birds given 3-mm diameter pellets had heavier proventriculus compared to those given 4.76-mm diameter pellets. 7. Overall, the data suggest that increasing the pellet length from 3 to 6 mm improved the body-weight gain and feed per body-weight gain during the grower period (d 10 to 21). While the positive effect on body-weight gain disappeared as the birds grew older, improvements in feed per body-weight gain were maintained over the finisher and whole grow-out periods only in 4.76-mm diameter pellets. Small diameter die holes and longer pellet lengths may be considered as potential manipulations to manufacture high-quality pellets under low conditioning temperatures.

[A case of laparoscopic surgery for a rectal carcinoid after ALTA therapy for an internal hemorrhoid].

PubMed

Aomatsu, Naoki; Nakamura, Masanori; Hasegawa, Tsuyoshi; Nakao, Shigetomi; Uchima, Yasutake; Aomatsu, Keiho

2014-11-01

We report a case of laparoscopic surgery for a rectal carcinoid after aluminum potassium and tannic acid (ALTA) therapy for an internal hemorrhoid. A 66-year-old man was admitted to our hospital because of bleeding during defecation. He was diagnosed via anoscopy with Goligher grade II internal hemorrhoids. Examination via colonoscopy revealed 2 yellowish submucosal tumors in the lower rectum that were 5mm and 10mm in diameter. A rectal carcinoid tumor was diagnosed based on histopathology. Abdominal computed tomography demonstrated no metastases to the liver or lymph nodes. First, we performed ALTA therapy for the internal hemorrhoids. Two weeks later, we performed laparoscopic-assisted low anterior resection (D2) for the rectal carcinoid. The patient was discharged without complications and has not experienced recurrence during the 2 years of follow-up care.

Optimizing working space in porcine laparoscopy: CT measurement of the effects of intra-abdominal pressure.

PubMed

Vlot, John; Wijnen, Rene; Stolker, Robert Jan; Bax, Klaas

2013-05-01

Several factors may affect volume and dimensions of the working space in laparoscopic surgery. The precise impact of these factors has not been well studied. In a porcine model, we used computed tomographic (CT) scanning for measuring working space volume and distances. In a first series of experiments, we studied the relationship between intra-abdominal pressure (IAP) and working space. Eleven 20 kg pigs were studied under standardized anesthesia and volume-controlled ventilation. Cardiorespiratory parameters were monitored continuously, and blood gas samples were taken at different IAP levels. Respiratory rate was increased when ETCO₂ exceeded 7 kPa. Breath-hold CT scans were made at IAP levels of 0, 5, 10, and 15 mmHg. Insufflator volumes were compared to CT-measured volumes. Maximum dimensions of pneumoperitoneum were measured on reconstructed CT images. Respiratory rate had to be increased in three animals. Mild hypercapnia and acidosis occurred at 15 mmHg IAP. Peak inspiratory pressure rose significantly at 10 and 15 mmHg. CT-measured volume increased relatively by 93 % from 5 to 10 mmHg IAP and by 19 % from 10 to 15 mmHg IAP. Comparing CT volumes to insufflator volumes gave a bias of 76 mL. The limits of agreement were -0.31 to +0.47, a range of 790 mL. The internal anteroposterior diameter increased by 18 % by increasing IAP from 5 to 10 mmHg and by 5 % by increasing IAP from 10 to 15 mmHg. At 15 mmHg, the total relative increase of the pubis-diaphragm distance was only 6 %. Abdominal width did not increase. CT allows for precise calculation of the actual CO₂ pneumoperitoneum volume, whereas the volume of CO₂ released by the insufflator does not. Increasing IAP up to 10 mmHg achieved most gain in volume and in internal anteroposterior diameter. At an IAP of 10 mmHg, higher peak inspiratory pressure was significantly elevated.

Micro-computed tomography study of the internal anatomy of mesial root canals of mandibular molars.

PubMed

Villas-Bôas, Marcelo Haas; Bernardineli, Norberti; Cavenago, Bruno Cavalini; Marciano, Marina; Del Carpio-Perochena, Aldo; de Moraes, Ivaldo Gomes; Duarte, Marco H; Bramante, Clovis M; Ordinola-Zapata, Ronald

2011-12-01

The aim of this study was to determine the mesiodistal and buccolingual diameter, apical volume, and the presence of isthmuses at the apical level of mesial root canals of mandibular molars. Sixty extracted first and second mandibular molars were scanned by using a SkyScan 1076 micro-computed tomography system with a voxel size of 18 μm. The apical thirds of the samples were reconstructed to allow a perpendicular section of the apical third by using the multiplanar reconstruction tool of the OsiriX software. The mesiodistal and the buccolingual distances of root canals were measured between the 1- to 4-mm levels. The type of root canal isthmuses present at these levels was classified by using modified criteria of Hsu and Kim. The volume of the root canal anatomy between the 1- to 3-mm apical levels was obtained by using the CTAN-CTVOL software. The medians of the mesiodistal diameter at the 1-, 2-, 3-, and 4-mm levels in the mesiobuccal and mesiolingual canals were 0.22 and 0.23 mm, 0.27 and 0.27 mm, 0.30 and 0.30 mm, and 0.36 and 0.35 mm, respectively. The buccolingual lengths at the 1-, 2-, 3-, and 4-mm levels were 0.37-0.35 mm, 0.55-0.41 mm, 0.54-0.49 mm, and 0.54 and 0.60 mm, respectively. The presence of isthmuses was more prevalent at the 3- to 4-mm level. However, 27 cases presented complete or incomplete isthmuses at the 1-mm apical level. The mean of the volume of the apical third was 0.83 mm(3), with a minimum value of 0.02 and a maximum value of 2.4 mm(3). Mesial root canals of mandibular molars do not present a consistent pattern. A high variability of apical diameters exists. The presence of isthmuses at the apical third was not uncommon even at the 1-mm apical level. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Radiographic inspection of porosity in pure titanium dumbbell castings.

PubMed

Nuñez, Juliana Maria Costa; Takahashi, Jessica Mie Ferreira Koyama; Henriques, Guilherme Elias Pessanha; Nóbilo, Mauro Antônio de Arruda; Consani, Rafael Leonardo Xediek; Mesquita, Marcelo Ferraz

2011-09-01

  Titanium frameworks are frequently indicated for implant supported prostheses; however, voids are usually encountered inside cast titanium.   This study aimed to confirm the efficacy of a radiographic technique for inspection of porosity in commercially pure titanium castings with different diameter.   Sixty dumbbell rods (n=20) with a central 1.5, 2.0 and 3.5mm diameter were prepared by lost-wax casting. Cast specimens were finished and polished and submitted to radiographic examination (90kV, 15mA, 0.6s and 10-13mm of distance) using periapical film. The radiographs were visually analysed for the presence of porosity in the extension of the dumbbell or in the central portion of the rods. Data were submitted to Pearson Chi-square test (5%).   The tested radiographic method proved to be suitable for the evaluation of cast frameworks. Internal porosities were observed in most of the specimens (91.7%) (p=0.0005); however, only 20% occurred on the central portion of the rods (p=0.612).   Internal porosities can be visualised through radiographs and occur mostly in small diameter structures. The radiographic evaluation of metal structures can improve the quality of frameworks and thereby potentially increase the longevity of the rehabilitation. © 2010 The Gerodontology Society and John Wiley & Sons A/S.

46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

Code of Federal Regulations, 2014 CFR

2014-10-01

... worn down to 6.4 mm (0.25 in) clearance for shafts of 229 mm (9 in) or less in diameter, 7.95 mm (0.3125 in) clearance for shafts exceeding 229 mm (9 in) but not exceeding 305 mm (12 in) in diameter, and 9.53 mm (0.375 in) clearance for shafts exceeding 305 mm (12 in) in diameter. (2) Where the...

46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

Code of Federal Regulations, 2012 CFR

2012-10-01

... worn down to 6.4 mm (0.25 in) clearance for shafts of 229 mm (9 in) or less in diameter, 7.95 mm (0.3125 in) clearance for shafts exceeding 229 mm (9 in) but not exceeding 305 mm (12 in) in diameter, and 9.53 mm (0.375 in) clearance for shafts exceeding 305 mm (12 in) in diameter. (2) Where the...

46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

Code of Federal Regulations, 2010 CFR

2010-10-01

... worn down to 6.4 mm (0.25 in) clearance for shafts of 229 mm (9 in) or less in diameter, 7.95 mm (0.3125 in) clearance for shafts exceeding 229 mm (9 in) but not exceeding 305 mm (12 in) in diameter, and 9.53 mm (0.375 in) clearance for shafts exceeding 305 mm (12 in) in diameter. (2) Where the...

46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

Code of Federal Regulations, 2011 CFR

2011-10-01

... worn down to 6.4 mm (0.25 in) clearance for shafts of 229 mm (9 in) or less in diameter, 7.95 mm (0.3125 in) clearance for shafts exceeding 229 mm (9 in) but not exceeding 305 mm (12 in) in diameter, and 9.53 mm (0.375 in) clearance for shafts exceeding 305 mm (12 in) in diameter. (2) Where the...

46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

Code of Federal Regulations, 2013 CFR

2013-10-01

... worn down to 6.4 mm (0.25 in) clearance for shafts of 229 mm (9 in) or less in diameter, 7.95 mm (0.3125 in) clearance for shafts exceeding 229 mm (9 in) but not exceeding 305 mm (12 in) in diameter, and 9.53 mm (0.375 in) clearance for shafts exceeding 305 mm (12 in) in diameter. (2) Where the...

Food waste impact on municipal solid waste angle of internal friction.

PubMed

Cho, Young Min; Ko, Jae Hac; Chi, Liqun; Townsend, Timothy G

2011-01-01

The impact of food waste content on the municipal solid waste (MSW) friction angle was studied. Using reconstituted fresh MSW specimens with different food waste content (0%, 40%, 58%, and 80%), 48 small-scale (100-mm-diameter) direct shear tests and 12 large-scale (430 mm × 430 mm) direct shear tests were performed. A stress-controlled large-scale direct shear test device allowing approximately 170-mm sample horizontal displacement was designed and used. At both testing scales, the mobilized internal friction angle of MSW decreased considerably as food waste content increased. As food waste content increased from 0% to 40% and from 40% to 80%, the mobilized internal friction angles (estimated using the mobilized peak (ultimate) shear strengths of the small-scale direct shear tests) decreased from 39° to 31° and from 31° to 7°, respectively, while those of large-scale tests decreased from 36° to 26° and from 26° to 15°, respectively. Most friction angle measurements produced in this study fell within the range of those previously reported for MSW. Copyright © 2010 Elsevier Ltd. All rights reserved.

Failure analysis of fractured dental zirconia implants.

PubMed

Gahlert, M; Burtscher, D; Grunert, I; Kniha, H; Steinhauser, E

2012-03-01

The purpose of the present study was the macroscopic and microscopic failure analysis of fractured zirconia dental implants. Thirteen fractured one-piece zirconia implants (Z-Look3) out of 170 inserted implants with an average in situ period of 36.75±5.34 months (range from 20 to 56 months, median 38 months) were prepared for macroscopic and microscopic (scanning electron microscopy [SEM]) failure analysis. These 170 implants were inserted in 79 patients. The patient histories were compared with fracture incidences to identify the reasons for the failure of the implants. Twelve of these fractured implants had a diameter of 3.25 mm and one implant had a diameter of 4 mm. All fractured implants were located in the anterior side of the maxilla and mandibula. The patient with the fracture of the 4 mm diameter implant was adversely affected by strong bruxism. By failure analysis (SEM), it could be demonstrated that in all cases, mechanical overloading caused the fracture of the implants. Inhomogeneities and internal defects of the ceramic material could be excluded, but notches and scratches due to sandblasting of the surface led to local stress concentrations that led to the mentioned mechanical overloading by bending loads. The present study identified a fracture rate of nearly 10% within a follow-up period of 36.75 months after prosthetic loading. Ninety-two per cent of the fractured implants were so-called diameter reduced implants (diameter 3.25 mm). These diameter reduced implants cannot be recommended for further clinical use. Improvement of the ceramic material and modification of the implant geometry has to be carried out to reduce the failure rate of small-sized ceramic implants. Nevertheless, due to the lack of appropriate laboratory testing, only clinical studies will demonstrate clearly whether and how far the failure rate can be reduced. © 2011 John Wiley & Sons A/S.

Micrometeoroid Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Smaller Particle Impacts

NASA Technical Reports Server (NTRS)

Ross, D. K.; Anz-Meador, P.; Liou, J.C.; Opiela, J.; Kearsley, A. T.; Grime, G.; Webb, R.; Jeynes, C.; Palitsin, V.; Colaux, J.;

Enhanced Numerical Tools for Computer Simulation of Coupled Physical Phenomena and Design of Components Made of Innovative Materials

NASA Astrophysics Data System (ADS)

Cegielski, M.; Hernik, S.; Kula, M.; Oleksy, M.

This section is based on paper [96], the objective of which is modeling of the unilateral damage effect in the aluminum alloy Al-2024, based on the nonlinear Armstrong-Frederick model Eq. 6.60 enriched by damage [170] with a continuous damage deactivation concept. The simulation is proposed in order to model the phenomenon of nonsymmetric hysteresis loop evolution due to different damage growth under tension and compression observed in the experiment [1]. The specimens used in the experiment were made of aluminum alloy Al-2024 (Table 7.1). The tests were carried out at room temperature on a servo-hydraulic INSTRON machine type 1340, using thin-walled tubes of the dimensions: internal diameter 15 mm and external diameter 18 mm.

[Distribution of corneal densitometry and its correlation with ocular stray light in healthy eyes].

PubMed

Wu, Zhiqing; Wang, Yan; Zhang, Lin; Wu, Di; Wei, Shengsheng; Su, Xiaolian

2014-01-01

To evaluate and investigate the distribution of corneal density and its Correlation with stray-light value in adult and healthy eyes. A prospective study. Human corneal specimens ranging in age between 20 and 49 years, 116 patients (232 eyes) in total, divided into three groups: 20-29, 30-39, 40-49. Pentacam was used to evaluate total corneal average density and corneal thickness at different diameter around the corneal apex, for corneal density were ≤ 2 mm, >2 mm and ≤ 6 mm, >6 mm and ≤ 10 mm, for corneal thickness were 2 mm, 6 mm and 10 mm, C-quant was used for the stray-light value. Software SPSS 17.0 was used for statistical analysis. Independent samples t testing method was applied to compare the corneal densitometry in different gender and between left eyes and right ones, One-way ANOVA was applied to analyze the differences of corneal density in different age groups and diameters. Pearson correlation analysis was applied to assess the correlation in corneal densitometry values of different diameters, between corneal density of different diameters and age, corneal density of different diameters and corneal thickness of different diameters, corneal density of different diameters and stray-light values. Corneal density for ≤ 2 mm, >2 mm and ≤ 6 mm, >6 mm and ≤ 10 mm diameter are 10.1 ± 1.5(8.2-16.7), 9.3 ± 1.3(7.9-14.2), 9.6 ± 1.7(7.3-16.2). Corneal density of >6 mm and ≤ 10 mm diameter in different age groups were 8.9 ± 1.1, 9.3 ± 1.2, 10.7 ± 2.1, there was a statistical difference in these values (F = 28.939, P = 0.000), and there was a positive correlation between corneal density of >6 mm and ≤ 10 mm diameter and age (r = 0.417, P = 0.000), There were no statistical differences in corneal density values of ≤ 2 mm and >2 mm and ≤ 6 mm in different age groups (F = 1.575, 1.436; P > 0.05), and they had no correlation with age (r = 0.002, 0.048; P > 0.05). There was no statistical difference in corneal density in different gender (t = 1.744, 1.647, -1.181; P > 0.05). Corneal density values of left eyes and right ones had positive relationships at the same diameter (r = 0.977, P = 0.000; r = 0.992, P = 0.000; r = 0.933, P = 0.000), and there were no statistical differences (t = 0.124, 0.199, -0.020;P > 0.05). Between corneal density values of different diameter, there are also some positive relationships, >6 mm and ≤ 10 mm and ≤ 2 mm (r = 0.710, P = 0.000), >6 mm and ≤ 10 mm and >2 mm and ≤ 6 mm (r = 0.748, P = 0.000), ≤ 2 mm and >2 mm and ≤ 6 mm (r = 0.973, P = 0.000), relationship between ≤ 2 mm and >2 mm and ≤ 6 mm, >2 mm and ≤ 6 mm and >6 mm and ≤ 10 mm was obvious, and there was statistical difference in them (F = 17.057, P = 0.000) . The ocular stray light value was 0.95 ± 0.19(0.48-1.38), Corneal density values of ≤ 2 mm, >2 mm and ≤ 6 mm and >6 mm and ≤ 10 mm diameter had positive relationships with the stray light value (r = 0.134,0.146,0.159, P = 0.042,0.026,0.016). Corneal density can be influenced by age, the influence from age infected the corneal density of peripheral more. There was no correlation between corneal density and corneal thickness. There were some influences of corneal density of healthy eyes to the ocular stray light.

Highly efficient solar-pumped Nd:YAG laser.

PubMed

Liang, Dawei; Almeida, Joana

2011-12-19

The recent progress in solar-pumped laser with Fresnel lens and Cr:Nd:YAG ceramic medium has revitalized solar laser researches, revealing a promising future for renewable reduction of magnesium from magnesium oxide. Here we show a big advance in solar laser collection efficiency by utilizing an economical Fresnel lens and a most widely used Nd:YAG single-crystal rod. The incoming solar radiation from the sun is focused by a 0.9 m diameter Fresnel lens. A dielectric totally internally reflecting secondary concentrator is employed to couple the concentrated solar radiation from the focal zone to a 4 mm diameter Nd:YAG rod within a conical pumping cavity. 12.3 W cw laser power is produced, corresponding to 19.3 W/m(2) collection efficiency, which is 2.9 times larger than the previous results with Nd:YAG single-crystal medium. Record-high slope efficiency of 3.9% is also registered. Laser beam quality is considerably improved by pumping a 3 mm diameter Nd:YAG rod.

Effect of the Coronal Wall Thickness of Dental Implants on the Screw Joint Stability in the Internal Implant-Abutment Connection.

PubMed

Lee, Ji-Hye; Huh, Yoon-Hyuk; Park, Chan-Jin; Cho, Lee-Ra

2016-01-01

To evaluate the effect of implant coronal wall thickness on load-bearing capacity and screw joint stability. Experimental implants were customized after investigation of the thinnest coronal wall thickness of commercially available implant systems with a regular platform diameter. Implants with four coronal wall thicknesses (0.2, 0.3, 0.4, and 0.5 mm) were fabricated. Three sets of tests were performed. The first set was a failure test to evaluate load-bearing capacity and elastic limit. The second and third sets were cyclic and static loading tests. After abutment screw tightening of each implant, vertical cyclic loading of 250 N or static loading from 250 to 800 N was applied. Coronal diameter expansion, axial displacement, and removal torque values of the implants were compared. Repeated measures analysis of variance (ANOVA) was used for statistical analysis (α = .05). Implants with 0.2-mm coronal wall thickness demonstrated significantly low load-bearing capacity and elastic limit (both P < .05). These implants also showed significantly large coronal diameter expansion and axial displacement after screw tightening (both P < .05). Greater vertical load and thinner coronal wall thickness significantly increased coronal diameter expansion of the implant, axial displacement of the abutment, and removal torque loss of the abutment screw (all P < .05). Implant coronal wall thickness of 0.2 mm produces significantly inferior load-bearing capacity and screw joint stability.

Atomization of liquids in a Pease-Anthony Venturi scrubber. Part II. Droplet dispersion.

PubMed

Gonçalves, J A S; Costa, M A M; Aguiar, M L; Coury, J R

2004-12-10

Droplet distribution is of fundamental importance to the performance of a Venturi scrubber. Ensuring good liquid distribution can increase performance at minimal liquid usage. In this study, droplet dispersion in a rectangular Pease-Anthony Venturi scrubber, operating horizontally, was examined both theoretically and experimentally. The Venturi throat cross-section was 24 mm x 35 mm, and the throat length varied from 63 to 140 mm. Liquid was injected through a single orifice (1.0 mm diameter) on the throat wall. This arrangement allowed the study of the influence of jet penetration on droplet distribution. Gas velocity at the throat was 58.3 and 74.6 m/s, and the liquid flow rate was 286, 559 and 853 ml/min. A probe with a 2.7 mm internal diameter was used to isokinetically remove liquid from several positions inside the equipment. It was possible to study liquid distribution close to the injection point. A new model for droplet dispersion, which incorporates the new description of the jet atomization process developed by the present authors in the first article of this series, is proposed and evaluated. The model predicted well the experimental data.

High-brightness-solar-pumped Nd:YAG laser design

NASA Astrophysics Data System (ADS)

Lando, Mordechai; Jenkins, David G.; Bernstein, Hana; O'Gallagher, Joseph J.; Winston, Roland; Lewandowski, Allan

1995-06-01

We have designed a Nd:YAG laser to be pumped by the High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory. Based on the unique features of the HFSF, the design objectives are high brightness and superior efficiency in primary mirror area utilization. The HFSF has a primary mirror of 11.5 m2 and a 1.85 f-number. With such a high f-number, the target is set off-axis and does not block incoming solar flux. Moreover, large f-number enables concentration which approaches the theoretical limit, and a two- dimensional non-imaging concentrator deposits the solar flux onto the internal part of a 10 mm diameter laser rod. For high brightness, we plan a wide low-loss fundamental mode and a laser rod aperture that suppresses high order modes. To get a fundamental mode, of up to a 2.5 mm waist, we have designed a convex-concave resonator, following well-known g1g2 equals 0.5 design for resonators with internal beam focusing. We have used the edge ray principle to design the concentrator, and ray traced the deposited power inside the laser rod. A 1.3% Nd doping level supports a maximal power deposition inside a 5 mm diameter.

Small Layer-wound ReBCO Solenoids

NASA Astrophysics Data System (ADS)

Polyakov, A. V.; Shcherbakov, V. I.; Shevchenko, S. A.; Surin, M. I.

The development of the next generation of high field superconducting magnet systems demands studies of new technological approach for its internal sections. Several small HTS solenoids (21 mm inner diameter, 32 layers) were fabricated by layer-winding technique from SuperPower type SCS-4050 ReBCO wire insulated by polyimide wrapping. Different designs of external and internal joints also were also tested. The highest field generated by HTS coil was 2.4 T in a 10 T background field (total field was 12.4 T) at 4.2 K and achieved current density in the coil was 498 A/mm2. The results will be used in development of HTS inner sections for 25 T superconducting magnet.

Morphology-related limitations of EVAR applicability in the treatment of AAA in West-Central Poland.

PubMed

Dzieciuchowicz, Łukasz; Tomczak, Jolanta; Strauss, Ewa; Oszkinis, Grzegorz

2018-05-14

To analyze the current applicability of endovascular aneurysm repair (EVAR) in patients with an infrarenal abdominal aortic aneurysm (AAAs) with indication for elective treatment in West-Central Poland. Computed tomography angiograms of 100 consecutive patients with infrarenal AAA deemed to require treatment were analyzed with an OsiriX DICOM viewer in 3D-MPR mode. Proximal neck diameter, length, angulation, shape, the presence of thrombus and calcification, distal neck diameter, and morphology of the iliac arteries were determined. Three sets of morphological criteria were established. The optimal criteria consisted of a non-conical proximal neck without moderate or severe calcification or thrombus, with a diameter of 18-28 mm, length of ≥15 mm, and β angulation of <60%; a distal neck with a diameter of ≥20 mm; a landing zone in the common iliac arteries with a length of ≥ 10 mm and diameter of ≤ 20 mm; and external iliac arteries with diameters of ≥7 mm. The suboptimal criteria included proximal neck diameters of 18-32 mm, neck lengths ≥10 mm, infrarenal neck angulations of up to 75˚, and common iliac artery diameters of up to 25 mm. Finally, the extended suboptimal criteria included proximal neck diameters of 16-34 mm and infrarenal neck angulations ≤90˚, without limits in the maximal diameter of the common iliac arteries. The median maximum aneurysm diameter was 61 mm. The optimal, suboptimal, and extended suboptimal criteria were met by 23%, 32%, and 53% of patients, respectively. The most common deviations were wide, conical, and angulated proximal necks and aneurysmal iliac arteries. The majority of patients with AAA deemed to be candidates for elective repair do not meet the most favorable criteria for EVAR. Availability of better endovascular solutions for conical, angulated, and wide necks and aneurysmal iliac arteries would likely expand EVAR applicability. Open repair remains a valid option. Copyright © 2018 Elsevier Inc. All rights reserved.

Aortoiliac morphologic correlations in aneurysms undergoing endovascular repair.

PubMed

Ouriel, Kenneth; Tanquilut, Eugene; Greenberg, Roy K; Walker, Esteban

2003-08-01

The feasibility of endovascular aneurysm repair depends on morphologic characteristics of the aortoiliac segment. Knowledge of such characteristics is relevant to safe deployment of a particular device in a single patient and to development of new devices for use in patients with a broader spectrum of anatomic variations. We evaluated findings on computed tomography scans for 277 patients being considered for endovascular aneurysm repair. Aortic neck length and angulation estimates were generated with three-dimensional trigonometry. Specific centerline points were recorded, corresponding to the aorta at the celiac axis, lowest renal artery, cranial aspect of the aneurysm sac, aortic terminus, right hypogastric artery origin, and left hypogastric origin. Aortic neck thrombus and calcium content were recorded, and neck conicity was calculated in degrees. Statistical analysis was performed with the Spearman rank correlation. Data are expressed as median and interquartile range. Median diameter of the aneurysms was 52 mm (interquartile range, 48-59 mm) in minor axis and 56 mm (interquartile range, 51-64 mm) in major axis, and median length was 88 mm (interquartile range, 74-103 mm). Median proximal aortic neck diameter was 26 mm (interquartile range, 22-29 mm), and median neck length was 30 mm (interquartile range, 18-45 mm). The common iliac arteries were similar in diameter (right artery, 16 mm [interquartile range, 13-20 mm]; left artery, 15 mm [interquartile range, 11-18 mm]) and length (right, 59 mm [interquartile range, 50-69 mm]; left, 60 mm [interquartile range, 49-70 mm]). Median angulation of the infrarenal aortic neck was 40 degrees (interquartile range, 29-51 degrees), and median angulation of the suprarenal segment was 45 degrees (interquartile range, 36-57 degrees). By gender, sac diameter, proximal neck diameter, and iliac artery diameter were significantly larger in men. Significant linear associations were identified between sac diameter and sac length, neck angulation, and iliac artery diameter. As the length of the aneurysm sac increased the proximal aortic neck length decreased. Conversely, as the sac length decreased sac eccentricity increased. Mural thrombus content within the neck increased with increasing neck diameter. There is considerable variability in aortoiliac morphologic parameters. Significant associations were found between various morphologic variables, links that are presumably related to a shared pathogenesis for aberration in aortoiliac diameter, length, and angulation. Ultimately this information can be used to develop new endovascular devices with broader applicability and improved long-term results.

Experimental application of pulsed Ho:YAG laser-induced liquid jet as a novel rigid neuroendoscopic dissection device.

PubMed

Ohki, Tomohiro; Nakagawa, Atsuhiro; Hirano, Takayuki; Hashimoto, Tokitada; Menezes, Viren; Jokura, Hidefumi; Uenohara, Hiroshi; Sato, Yasuhiko; Saito, Tsutomu; Shirane, Reizo; Tominaga, Teiji; Takayama, Kazuyoshi

2004-01-01

Although water jet technology has been considered as a feasible neuroendoscopic dissection methodology because of its ability to perform selective tissue dissection without thermal damage, problems associated with continuous use of water and the ensuing fountain-effect-with catapulting of the tissue-could make water jets unsuitable for endoscopic use, in terms of safety and ease of handling. Therefore, the authors experimented with minimization of water usage during the application of a pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser-induced liquid jet (LILJ), while assuring the dissection quality and the controllability of a conventional water jet dissection device. We have developed the LILJ generator for use as a rigid neuroendoscope, discerned its mechanical behavior, and evaluated its dissection ability using the cadaveric rabbit ventricular wall. The LILJ generator is incorporated into the tip of a stainless steel tube (length: 22 cm; internal diameter: 1.0 mm; external diameter: 1.4 mm), so that the device can be inserted into a commercial, rigid neuroendoscope. Briefly, the LILJ is generated by irradiating an internally supplied water column within the stainless steel tube using the pulsed Ho:YAG laser (wave length: 2.1 microm, pulse duration time: 350 microseconds) and is then ejected through the metal nozzle (internal diameter: 100 microm). The Ho:YAG laser pulse energy is conveyed through optical quartz fiber (core diameter: 400 microm), while cold water (5 degrees C) is internally supplied at a rate of 40 ml/hour. The relationship between laser energy (range: 40-433 mJ/pulse), standoff distance (defined as the distance between the tip of the optical fiber and the nozzle end; range: 10-30 mm), and the velocity, shape, pressure, and average volume of the ejected jet were analyzed by means of high-speed camera, PVDF needle hydrophone, and digital scale. The quality of the dissection plane, the preservation of blood vessels, and the penetration depth were evaluated using five fresh cadaveric rabbit ventricular walls, under neuroendoscopic vision. Jet velocity (7.0-19.6 m/second) and pressure (0.07-0.28 MPa) could be controlled by varying the laser energy, which determined the penetration depth in the cadaveric rabbit ventricular wall (0.07-1.30 mm/shot). The latter could be cut into desirable shapes-without thermal effects-under clear neuroendoscopic vision. The average volume of a single ejected jet could be confined to 0.42-1.52 microl/shot, and there was no accompanying generation of shock waves. Histological specimens revealed a sharp dissection plane and demonstrated that blood vessels of diameter over 100 microm could be preserved, without thermal damage. The present pulsed LILJ system holds promise as a safe and reliable dissection device for deployment in a rigid neuroendoscope. Copyright 2004 Wiley-Liss, Inc.

ERDEC Contribution to the 1993 International Treaty Verification Round Robin Exercise 4

DTIC Science & Technology

1994-07-01

COLUMN Detector: MS (Finnigan 5100) Phase: AT-5 Manufacturer: Alltech GC CONDITIONS Length: 25 m Carrier gas: Helium Inner diameter: 0.25 mm Carrier...ionized in the ion source. The resulting CH,* then chemically reacts with the analyte. The advantage of this technique is that because less energy is

Frequency of postnatal hydronephrosis in infants with a renal anterior-posterior pelvic diameter > 4 mm on midtrimester ultrasound.

PubMed

Chou, Ching-Yu; Chen, Li-Ching; Cheong, Mei-Leng; Tsai, Ming-Song

2015-10-01

To examine the association of antenatal renal pelvic dilatation observed on midtrimester ultrasound screening with the presence of hydronephrosis in newborn infants. The records of patients who received fetal ultrasound examination at 18-28 weeks' gestation from May 2008 to March 2012 were retrospectively reviewed. A fetal renal pelvic anterior-posterior (AP) diameter > 4 mm was considered abnormal and ≤ 4 mm was considered normal. On postnatal ultrasound, a renal pelvic AP diameter > 3 mm was considered to indicate hydronephrosis and ≤ 3 mm was considered normal. The association of postnatal hydronephrosis with prenatal pelvic AP diameter was determined using binary logistic regression analysis. The study comprised 1310 newborn infants: 684 (52.2%) male and 626 (47.8%) female. Multivariate analysis showed a right or left prenatal AP renal pelvic diameter > 4 mm was associated with a higher risk of postnatal hydronephrosis compared with a right and left prenatal AP renal pelvic diameter ≤ 4 mm. Boys had a higher risk for postnatal hydronephrosis than girls (odds ratio = 2.42, p < 0.05). An antenatal renal pelvic AP diameter > 4 mm on midtrimester ultrasound is predictive of postnatal hydronephrosis. Copyright © 2015. Published by Elsevier B.V.

Evaluation of in vivo behavior of ameroid ring constrictors in dogs with congenital extrahepatic portosystemic shunts using computed tomography.

PubMed

Hunt, Geraldine B; Culp, William T N; Mayhew, Kelli N; Mayhew, Philipp; Steffey, Michele A; Zwingenberger, Allison

2014-10-01

To evaluate the in vivo pattern of ameroid constrictor closure of congenital extrahepatic portosystemic shunts in dogs. Prospective study. Dogs (n = 22) with congenital extrahepatic portosystemic shunts. Contrast-enhanced computed tomography was performed immediately before, and at least 8 weeks after placement of ameroid ring constrictors. Plastic-encased ameroid constrictors were used in 17 dogs and metal constrictors in 5 dogs. Presence of residual flow through the portosystemic shunt, additional anomalous vessels, acquired shunts and soft tissue associated with the ameroid constrictor was recorded. Postoperative internal diameter was recorded for the 17 plastic constrictors. Correlations between internal diameter and pre- and postoperative serum protein concentration were analyzed. No ameroid constrictor closed completely: shunt occlusion was always dependent on soft tissue within the ameroid ring. Residual flow through the shunt was present in 4 dogs (18%), although this caused persistent elevation of shunt fraction in only 1 dog (dog 8). The change in ameroid constrictor internal diameter was not significantly correlated with serum protein concentration. Complete shunt occlusion after AC placement is usually dependent on soft tissue reaction. Ameroid constrictors ≥5 mm diameter may not promote complete shunt occlusion. © Copyright 2014 by The American College of Veterinary Surgeons.

Early pregnancy assessment with transvaginal ultrasound scanning.

PubMed Central

Daya, S; Woods, S; Ward, S; Lappalainen, R; Caco, C

1991-01-01

OBJECTIVE: To establish normal parameters in early pregnancy through transvaginal ultrasonography so that gestational age can be determined and to correlate the sonographic findings with serum human chorionic gonadotropin (hCG) levels calibrated against the first international reference preparation standard. SETTING: Infertility clinic. PATIENTS: Thirty-five women with normal intrauterine pregnancy. INTERVENTIONS: Serial measurement of the serum hCG level and the diameter of the gestational sac through transvaginal ultrasonography. MAIN RESULTS: The gestational sac could not be visualized when the hCG level was less than 1100 IU/L. The average growth rate of the sac was 0.9 mm/d. The threshold values for sac diameter, serum hCG level and gestational age below which the yolk sac was not visible were 3.7 mm, 1900 IU/L and 36 days respectively; the corresponding values above which the yolk sac was always visible were 6.7 mm, 5800 IU/L and 40 days. The threshold values below which cardiac activity was not visible were 8.3 mm, 9200 IU/L and 41 days respectively, and the corresponding values above which cardiac activity was always visible were 14.0 mm, 24,000 IU/L and 46 days. The mean gestational ages and the 95% confidence and prediction intervals were tabulated so that measurement of the gestational sac diameter could be used to estimate gestational age early in normal pregnancy. CONCLUSIONS: Transvaginal ultrasonography enables detection of an intrauterine sac and reliable estimation of gestational age on the basis of sac dimensions before an embryo can be seen. PMID:1993291

Depth of composite polymerization within simulated root canals using light-transmitting posts.

PubMed

Lui, J L

1994-01-01

In this study, the depth of cure of composite resins cured within simulated root canals by means of light-transmitting plastic posts was compared to that achieved by the conventional light-curing method. Six sizes of posts with diameters of 1.05 mm, 1.20 mm, 1.35 mm, 1.50 mm, 1.65 mm, and 1.80 mm were investigated. In general, the larger the post diameter, the greater was the depth of cure. There were significant differences in the depth of cure between the control and all sizes of posts investigated. There were also significant differences between the various post diameters except for the 1.35 mm and 1.50 mm diameter posts. It was possible to achieve a depth of cure exceeding 11 mm using these light-transmitting posts.

Damage analysis of CF/AF hybrid fabric reinforced plastic laminated composites with scanned image microscopy

NASA Astrophysics Data System (ADS)

Miyasaka, Chiaki; Kasano, Hideaki; Shull, Peter J.

2004-07-01

The article presents an experimental study that has been conducted to evaluate the impact loading damage within hybrid fabric laminates-carbon and Aramid fibers. The experiments have been undertaken on a series of interply hybrid specimens with different preprags stacking sequences. Impact damage was created using an air-gun like impact device propelling spherical steel balls with diameters of 5.0mm and 10.0mm and having velocities of 113m/s and 40m/s respectively. The resulting specimen surface and internal damage (e.g., micro-cracking and debonding) was visualized nondestructively by a scanning acoustic microscope (SAM) while further interrogation of specific internal damage was visualized using a scanning electron microscope (SEM) on cross-sectioned panels.

Abutment height influences the effect of platform switching on peri-implant marginal bone loss.

PubMed

Galindo-Moreno, Pablo; León-Cano, Ana; Monje, Alberto; Ortega-Oller, Inmaculada; O'Valle, Francisco; Catena, Andrés

2016-02-01

The purpose was to radiographically analyze and compare the marginal bone loss (MBL) between implants with different mismatching distance and to study the influence of the prosthetic abutment height on the MBL in association with the related mismatching distances. This retrospective study included 108 patients in whom 228 implants were placed, 180 with diameter of 4.5 mm and 48 with diameter of 5 mm. All patients received OsseoSpeed™ implants with internal tapered conical connection (Denstply Implants). Different mismatching distances were obtained, given that all implants were loaded with the same uni-abutment type (Lilac; Denstply Implants). Data were gathered on age, gender, bone substratum, smoking habits, previous history of periodontitis, and prosthetic features. MBL was analyzed radiographically at 6 and 18 months post-loading. Mixed linear analysis of mesial and distal MBL values yielded significant effects of abutment, implant diameter, follow-up period, bone substratum, smoking, and abutment × time interaction. MBL was greater at 18 vs. 6 months, for short vs. long abutments, for grafted vs. pristine bone, for a heavier smoking habit, and for implants with a diameter of 5.0 vs. 4.5 mm. Greater mismatching does not minimize the MBL; abutment height, smoking habit, and bone substratum may play a role in the MBL over the short- and medium term. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Experimental and numerical investigations of heat transfer and thermal efficiency of an infrared gas stove

NASA Astrophysics Data System (ADS)

Charoenlerdchanya, A.; Rattanadecho, P.; Keangin, P.

2018-01-01

An infrared gas stove is a low-pressure gas stove type and it has higher thermal efficiency than the other domestic cooking stoves. This study considers the computationally determine water and air temperature distributions, water and air velocity distributions and thermal efficiency of the infrared gas stove. The goal of this work is to investigate the effect of various pot diameters i.e. 220 mm, 240 mm and 260 mm on the water and air temperature distributions, water and air velocity distributions and thermal efficiency of the infrared gas stove. The time-dependent heat transfer equation involving diffusion and convection coupled with the time-dependent fluid dynamic equation is implemented and is solved by using the finite element method (FEM). The computer simulation study is validated with an experimental study, which is use standard experiment by LPG test for low-pressure gas stove in households (TIS No. 2312-2549). The findings revealed that the water and air temperature distributions increase with greater heating time, which varies with the three different pot diameters (220 mm, 240 mm and 260 mm). Similarly, the greater heating time, the water and air velocity distributions increase that vary by pot diameters (220, 240 and 260 mm). The maximum water temperature in the case of pot diameter of 220 mm is higher than the maximum water velocity in the case of pot diameters of 240 mm and 260 mm, respectively. However, the maximum air temperature in the case of pot diameter of 260 mm is higher than the maximum water velocity in the case of pot diameters of 240 mm and 220 mm, respectively. The obtained results may provide a basis for improving the energy efficiency of infrared gas stoves and other equipment, including helping to reduce energy consumption.

Improved spectrophotometric cell for hydrothermal solutions

USGS Publications Warehouse

Susak, N.J.; Crerar, D.A.; Forseman, T.C.; Haas, J.L.

1981-01-01

A simple, inexpensive spectrophotometric cell was designed for use with aqueous solutions for which temperature is a maximum of 325??C and pressure, 28 MPa. The cell has an internal volume of 5 ml and a path length of 1.31 cm. Each furnace assembly is 120 mm in diameter ?? 150 mm high and will fit into most commercial spectrophotometers. Temperature is controlled by a standard set-point controller and a balancing circuit that is used to maintain the temperature of the sample and reference cell within 1??C of each other at any temperature.

915MHz microwave ablation with high output power in in vivo porcine spleens.

PubMed

Gao, Yongyan; Wang, Yang; Duan, Yaqi; Li, Chunling; Sun, Yuanyuan; Zhang, Dakun; Lu, Tong; Liang, Ping

2010-07-01

The purpose of this study was to evaluate the efficacy of 915 MHz microwave (MW) ablation with high output power in in vivo porcine spleens. MW ablations were performed in 9 porcine spleens with an internally cooled 915 MHz antenna. Thermocouples were placed at 5, 10, 15, 20 mm away from the antenna to measure temperatures in real-time during MW emission. The energy was applied for 10 min at high output power of 60 W, 70 W or 80 W. Gross specimens were sectioned and measured to determine ablation size. Representative areas were examined by light microscopy and electron microscopy. Coagulation sizes and temperatures were compared among the three power groups. Hematoxylin-eosin staining showed irreversible necrosis in the splenic coagulation area after MW ablation. As the power was increased, long-axis diameter enlarged significantly (p<.05). Short-axis diameter also tended to increase, but there were no statistical difference (p>.05). The coagulation size of long-axis and short-axis diameter with 80 W in vivo spleen ablation was 6.43+/-0.52 and 4.95+/-0.30 cm, respectively. With the increase of output power, maximum temperatures at 5, 10, 15, 20 mm from the antenna were increased accordingly (p<.05). The maximum temperature with 80 W at 5 and 20 mm from the antenna reached 146.17+/-6.65 and 72.38+/-4.23 degrees C respectively. With internally cooled antenna and high output power, 915 MHz MW ablation in the spleen could produce irreversible tissue necrosis of clinical significance. MW ablation may be used as a promising minimally invasive method for the treatment of splenic diseases. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Impact verification of space suit design for space station

NASA Technical Reports Server (NTRS)

Fish, Richard H.

1987-01-01

The ballistic limits of single sheet and double sheet structures made of 6061 T6 Aluminum of 1.8 mm and larger nominal thickness were investigated for projectiles of 1.5 mm diameter fired in the Vertical Gun Range Test Facility and NASA Ames Research Center. The hole diameters and sheet deformation behavior were studied for various ratios of sheet spacing to projectile diameter. The results indicate that for projectiles of less than 1.5 mm diameter the ballistic limit exceeds the nominal 10 km/sec orbital debris encounter velocity, if a single-sheet suit of 1.8 mm thickness is behind a single bumper sheet of 1 mm thickness spaced 12.5 mm apart.

Variations the diameter tip of electrode on the resistance spot welding using electrode Cu on worksheet Fe

NASA Astrophysics Data System (ADS)

Baskoro, A. S.; Sugeng, S.; Sifa, Agus; Badruzzaman; Endramawan, Tito

2018-04-01

Resistance Spot Weld (RSW) is a welding technology which plays an important role that is often used in industry in large manufacturing industries, especially in the automotive sector, some of the parameters are affecting the welding process that give impact in the weld quality, diameter tip important impact on the resistance spot welding, This study can be categorized as experimental study by using Electrode material such as Cu and Fe Worksheet Materials, with a material thickness of 1 mm,0,8 mm, and 0,6 mm on each worksheet, and the large diameter of tip electrode (5√t) depend on the thickness of worksheet. Testing the material in the electrode and the worksheet by testing the composition and tensile test, and the hardness of the material used are to know the material used certainly. The result of the welding process was done by using the parameters voltage of 8KV, with a duty cycle of 50% using a variation of the time 8s-10s, and variations the electrode tip diameter that are affected by the thickness of the worksheet 5\\sqrt{t}, plate thickness used 1 mm, 0,8 mm and 0,6 mm, so that the electrodes was used to a thickness of 1 mm diameter tip electrode 5 mm, thickness 0,8 mm with an electrode tip diameter 4,5 mm and a thickness 0,6 mm with an electrode diameter of 4 mm, with current welding parameter 8kVA, and variations in holding time 10s, 9s and 8s 50% duty cycle, then testing welds with the standard shear test refers ASTM A370-2012 with more results to a thickness of 0,6 has the ability to withstand greater load on the holding time 8s and 9s, 10s, to a thickness 0,8 mm and 1 mm shear test results demonstrate the ability to withstand loads on the holding time of 10s and 9s have a greater ability than 8s on worksheet that has thickness 1 mm at a holding time of 10s, and then Maximum shear test averaging of 36,41 N at a worksheet with a thickness of 0,8 mm (diameter tip 4,5 mm) at a holding time of 8s and a mean minimum shear stress of 23,73 N at worksheet that has thickness 0,6 mm (diameter tip 4 mm).

Effect of embedded dexamethasone in cochlear implant array on insertion forces in an artificial model of scala tympani.

PubMed

Nguyen, Yann; Bernardeschi, Daniele; Kazmitcheff, Guillaume; Miroir, Mathieu; Vauchel, Thomas; Ferrary, Evelyne; Sterkers, Olivier

2015-02-01

Loading otoprotective drug into cochlear implant might change its mechanical properties, thus compromising atraumatic insertion. This study evaluated the effect of incorporation of dexamethasone (DXM) in the silicone of cochlear implant arrays on insertion forces. Local administration of DXM with embedded array can potentially reduce inflammation and fibrosis after cochlear implantation procedure to improve hearing preservation and reduce long-term impedances. Four models of arrays have been tested: 0.5-mm distal diameter array (n = 5) used as a control, drug-free 0.4-mm distal diameter array (n = 5), 0.4-mm distal diameter array with 1% eluded DXM silicone (n = 5), and 0.4-mm distal diameter array with 10% eluded DXM silicone (n = 5). Via a motorized insertion bench, each array has been inserted into an artificial scala tympani model. The forces were recorded by a 6-axis force sensor. Each array was tested seven times for a total number of 140 insertions. During the first 10-mm insertion, no difference between the four models was observed. From 10- to 24-mm insertion, the 0.5-mm distal diameter array presented higher insertion forces than the drug-free 0.4-mm distal diameter arrays, with or without DXM. Friction forces for drug-free 0.4-mm distal diameter array and 0.4-mm distal diameter DXM eluded arrays were similar on all insertion lengths. Incorporation of DXM in silicone for cochlear implant design does not change electrode array insertion forces. It does not raise the risk of trauma during array insertion, making it suitable for long-term in situ administration to the cochlea.

Heat transfer and hydrodynamic investigations of a baffled slurry bubble column

NASA Astrophysics Data System (ADS)

Saxena, S. C.; Chen, Z. D.

1992-09-01

Heat transfer and hydrodynamic investigations have been conducted in a 0.108 m internal diameter bubble column at ambient conditions. The column is equipped with seven 19mm diameter tubes arranged in an equilateral triangular pitch of 36.5 mm. A Monsanto synthetic heat transfer fluid, Therminol-66 having a viscosity of 39.8 cP at 303 K, is used as a liquid medium. Magnetite powders, average diameters 27.7 and 36.6 µm, in five concentrations up to 50 weight percent in the slurry, are used. As a gas phase, industrial grade nitrogen of purity 99.6 percent is employed. Gas holdup in different operating modes and regimes have been measured for the two- and three-phase systems over a superficial gas velocity range up to 0.20 m/s in the semi-batch mode. Heat transfer coefficients are measured at different tube locations in the bundle at different radial and vertical locations over a range of operating conditions. All these data are compared with the existing literature correlations and models. New correlations are proposed.

Hydrothermal growth of potassium titanyl arsenate (KTA) in large autoclaves

NASA Astrophysics Data System (ADS)

Belt, Roger F.; Ings, John B.

1993-03-01

Solubility and phase relations were investigated for selected K/As ratios in KH2AsO4-KOH solutions at 600°C and 2040 atm. All initial data were obtained with 5 mm diameter x 50 mm long platinum capsules in Tem-Pres type autoclaves. The most favorable results were repeated in Morey type autoclaves of 2.2 cm diameter. The P-V-T data were generated and extrapolated for use in gold liners and René 41 autoclaves with a pressure balancing method. Transfer to the 3.8 cm diameter x 46 cm long autoclaves with gold liners was achieved. Both nutrient and larger seed crystals were grown from a K2WO4-Li2WO4 flux. The internal and external degrees of fill were adjusted to obtain a balance of pressure at 1700 atm and 590°C. Initial growth runs were made for 1-2 weeks under a gradient of 30°C with a 4 molar KH2AsO4 mineralizer. Natural facet seeds were employed first while later runs utilized (011) cut and polished seeds.

Effect of mold diameter on the depth of cure of a resin-based composite material.

PubMed

Erickson, Robert L; Barkmeier, Wayne W

2017-02-01

The purpose of this study was to examine the effect of mold diameter on depth of cure of a resin-based composite material for varying amounts of irradiation. A resin-based composite was light-cured for 10-80 s in stainless-steel molds of either 6 mm or 4 mm in diameter and then dark-stored for 24 h. Specimens were then scraped back and the length of the cured specimens was measured to provide depth of cure (D SB ). Radiant exposure to each of the mold diameters was determined by measuring the power. The D SB values using the 4-mm molds were lower than those of the 6-mm molds. The average difference between the two groups for each irradiation time was 0.45 ± 0.02 mm. A fixed depth of cure required about 39% more irradiation time for the 4-mm mold than for the 6-mm mold but 75% more radiant exposure. The difference in cure depth for a fixed radiant exposure was 0.79 mm. A better comparison of depth of cure is obtained by using identical radiant exposures for different mold diameters. It is believed that greater loss of light by absorption at the stainless-steel cylinder walls for the 4-mm-diameter cylinders accounts for the lower depth of cure when compared with the 6-mm molds. © 2017 Eur J Oral Sci.

INTERNAL REPAIR OF PIPELINES

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

Robin Gordon; Bill Bruce; Ian Harris

2004-04-12

The two broad categories of deposited weld metal repair and fiber-reinforced composite liner repair technologies were reviewed for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Preliminary test programs were developed for both deposited weld metal repair and for fiber-reinforced composite liner repair. Evaluation trials have been conducted using a modified fiber-reinforced composite liner provided by RolaTube and pipe sections without liners. All pipe section specimens failed in areas of simulated damage. Pipe sections containing fiber-reinforcedmore » composite liners failed at pressures marginally greater than the pipe sections without liners. The next step is to evaluate a liner material with a modulus of elasticity approximately 95% of the modulus of elasticity for steel. Preliminary welding parameters were developed for deposited weld metal repair in preparation of the receipt of Pacific Gas & Electric's internal pipeline welding repair system (that was designed specifically for 559 mm (22 in.) diameter pipe) and the receipt of 559 mm (22 in.) pipe sections from Panhandle Eastern. The next steps are to transfer welding parameters to the PG&E system and to pressure test repaired pipe sections to failure. A survey of pipeline operators was conducted to better understand the needs and performance requirements of the natural gas transmission industry regarding internal repair. Completed surveys contained the following principal conclusions: (1) Use of internal weld repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling (HDD) when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) Pipe diameter sizes range from 50.8 mm (2 in.) through 1,219.2 mm (48 in.). The most common size range for 80% to 90% of operators surveyed is 508 mm to 762 mm (20 in. to 30 in.), with 95% using 558.8 mm (22 in.) pipe. An evaluation of potential repair methods clearly indicates that the project should continue to focus on the development of a repair process involving the use of GMAW welding and on the development of a repair process involving the use of fiber-reinforced composite liners.« less

Variations and anomalies of the posterior communicating artery in Northwest Indian brains.

PubMed

Sahni, Daisy; Jit, Indar; Lal, Vivek

2007-10-01

The PCoA is a major branch of the supraclinoid internal carotid artery. Thorough knowledge of the anatomy and awareness of the variations and anomalies are of clinical importance. The PCoA was studied in 200 male and 80 female adults and in 20 male and 25 female children. These were medicolegal cases that died of an accident or poisoning after staying in a hospital for a few days. In addition to autopsy specimens, PCoA was also examined in 45 fetuses obtained from the department of obstetrics and gynecology of this institute. In fetal brains, at 61 to 70 mm CR stage, the average diameter of PCoA was more than that of the proximal part of the PCA; at 91 to 100 mm CR stage, the diameters of both vessels were equal and remained so until 130 mm CR stage; thereafter, the diameter of the proximal part of PCA became larger than PCoA. Incidence of tortuosity was more on the left than on the right side in children, and the reverse was the case in adults. Tortuosity was not found in fetal brains. The incidence of hypoplasticity and absence of PCoA in children and adults in both sexes were noted. The embryonic type (where the diameter of PCoA is more than the diameter of proximal part of PCA) was observed in 3 children and 20 adults. The incidence of aneurysms involving PCoA was 0.92% in adults. They were not seen in fetuses, newborns, and children. Because of hemodynamic factors in fetuses of more than 130 mm CR stage, the diameter of PCA becomes larger than that of the PCoA. An aneurysm was seen in only 1 male adult (0.5%), other anomalies present were absence, hypoplasticity, and duplication of PCoA. Present observations were different from the findings of 2 groups of the Indian workers (J Neurosurg 1984;60:572-576; J Anat Soc India 1970;19:71-79). Case history of the patients with anomalies of PCoA did not show any mental aberration.

Influence of the weighing bar size to determine optimal time of biodiesel-glycerol separation by using the buoyancy weighing-bar method

NASA Astrophysics Data System (ADS)

Tambun, R.; Sibagariang, Y.; Manurung, J.

2018-02-01

The buoyancy weighing-bar method is a novel method in the particle size distribution measurement. This method can measure particle size distributions of the settling particles and floating particles. In this study, the buoyancy weighing-bar method is applied to determine optimal time of biodiesel-glycerol separation. The buoyancy weighing-bar method can be applied to determine the separation time because biodiesel and glycerol have the different densities. The influences of diameter of weighing-bar by using the buoyancy weighing-bar method would be experimentally investigated. The diameters of weighing-bar in this experiment are 8 mm, 10 mm, 15 mm and 20 mm, while the graduated cylinder (diameter : 65 mm) is used as vessel. The samples used in this experiment are the mixture of 95 % of biodiesel and 5 % of glycerol. The data obtained by the buoyancy weighing-bar method are analized by using the gas chromatography to determine the purity of biodiesel. Based on the data obtained, the buoyancy weighing-bar method can be used to detect the separation time of biodiesel-glycerol by using the weighing-bar diameter of 8 mm, 10 mm, 15 mm and 20 mm, but the most accuracy in determination the biodiesel-glycerol separation time is obtained by using the weighing-bar diameter of 20 mm. The biodiesel purity of 97.97 % could be detected at 64 minutes by using the buoyancy weighing-bar method when the weighing-bar diameter of 20 mm is used.

Predictors of antegrade flow at internal carotid artery during carotid artery stenting with proximal protection.

PubMed

Harada, Kei; Kakumoto, Kosuke; Oshikata, Shogo; Fukuyama, Kozo

2018-06-01

Carotid artery stenting (CAS) with proximal occlusion effectively prevent distal cerebral embolism by flow arrest at internal carotid artery (ICA); however, the method can expose antegrade flow at ICA due to incomplete flow arrest. The aim of this study was to identify predictors of antegrade flow during CAS with proximal protection. We retrospectively analyzed clinical and angiographic data among 143 lesions treated with CAS with proximal protection by occluding the common carotid artery (CCA) and external carotid artery (ECA). Flow arrest or antegrade flow at ICA was confirmed by contrast injection during proximal protection. Antegrade flow at ICA was observed in 12 lesions (8.4%). Compared with lesions in which flow arrest of ICA was achieved, the diameter of the superior thyroid artery (STA) was significantly larger (2.4 ± 0.34 vs. 1.4 ± 0.68 mm, p < 0.001), and the rate of ECA branches other than the STA located 0-10 mm above the bifurcation was significantly higher (50 vs. 8.4%, p < 0.001). Results of multivariate analysis revealed that a diameter of the STA ≥ 2.3 mm (OR 44, 95% CI 8.1-237; p < 0.001) and ECA branches other than the STA located 0-10 mm above the bifurcation (OR 6.0, 95% CI 1.1-32; p = 0.036) were independent predictors of antegrade flow. Distal filter protection should be combined with proximal protection for the lesions with antegrade flow to prevent distal migration of the carotid debris.

Implant-bone interface stress distribution in immediately loaded implants of different diameters: a three-dimensional finite element analysis.

PubMed

Ding, Xi; Zhu, Xing-Hao; Liao, Sheng-Hui; Zhang, Xiu-Hua; Chen, Hong

2009-07-01

To establish a 3D finite element model of a mandible with dental implants for immediate loading and to analyze stress distribution in bone around implants of different diameters. Three mandible models, embedded with thread implants (ITI, Straumann, Switzerland) with diameters of 3.3, 4.1, and 4.8 mm, respectively, were developed using CT scanning and self-developed Universal Surgical Integration System software. The von Mises stress and strain of the implant-bone interface were calculated with the ANSYS software when implants were loaded with 150 N vertical or buccolingual forces. When the implants were loaded with vertical force, the von Mises stress concentrated on the mesial and distal surfaces of cortical bone around the neck of implants, with peak values of 25.0, 17.6 and 11.6 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains (5854, 4903, 4344 muepsilon) were located on the buccal cancellous bone around the implant bottom and threads of implants. The stress and strain were significantly lower (p < 0.05) with the increased diameter of implant. When the implants were loaded with buccolingual force, the peak von Mises stress values occurred on the buccal surface of cortical bone around the implant neck, with values of 131.1, 78.7, and 68.1 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains occurred on the buccal surface of cancellous bone adjacent to the implant neck, with peak values of 14,218, 12,706, and 11,504 microm, respectively. The stress of the 4.1-mm diameter implants was significantly lower (p < 0.05) than those of 3.3-mm diameter implants, but not statistically different from that of the 4.8 mm implant. With an increase of implant diameter, stress and strain on the implant-bone interfaces significantly decreased, especially when the diameter increased from 3.3 to 4.1 mm. It appears that dental implants of 10 mm in length for immediate loading should be at least 4.1 mm in diameter, and uniaxial loading to dental implants should be avoided or minimized.

Temperature Effects on the Magnetic Properties of Silicon-Steel Sheets Using Standardized Toroidal Frame

PubMed Central

Wu, Cheng-Ju; Lin, Shih-Yu; Chou, Shang-Chin; Tsai, Chia-Yun; Yen, Jia-Yush

2014-01-01

This study designed a detachable and standardized toroidal test frame to measure the electromagnetic characteristic of toroidal laminated silicon steel specimens. The purpose of the design was to provide the measurements with standardized and controlled environment. The device also can withstand high temperatures (25–300°C) for short time period to allow high temperature tests. The accompanying driving circuit facilitates testing for high frequency (50–5,000 Hz) and high magnetic flux (0.2–1.8 T) conditions and produces both sinusoidal and nonsinusoidal test waveforms. The thickness of the stacked laminated silicon-steel sheets must be 30~31 mm, with an internal diameter of 72 mm and an outer diameter of 90 mm. With the standardized setup, it is possible to carry out tests for toroidal specimen in high temperature and high flux operation. The test results show that there is a tendency of increased iron loss under high temperature operation. The test results with various driving waveforms also provide references to the required consideration in engineering designs. PMID:25525629

Temperature effects on the magnetic properties of silicon-steel sheets using standardized toroidal frame.

PubMed

Wu, Cheng-Ju; Lin, Shih-Yu; Chou, Shang-Chin; Tsai, Chia-Yun; Yen, Jia-Yush

2014-01-01

This study designed a detachable and standardized toroidal test frame to measure the electromagnetic characteristic of toroidal laminated silicon steel specimens. The purpose of the design was to provide the measurements with standardized and controlled environment. The device also can withstand high temperatures (25-300°C) for short time period to allow high temperature tests. The accompanying driving circuit facilitates testing for high frequency (50-5,000 Hz) and high magnetic flux (0.2-1.8 T) conditions and produces both sinusoidal and nonsinusoidal test waveforms. The thickness of the stacked laminated silicon-steel sheets must be 30~31 mm, with an internal diameter of 72 mm and an outer diameter of 90 mm. With the standardized setup, it is possible to carry out tests for toroidal specimen in high temperature and high flux operation. The test results show that there is a tendency of increased iron loss under high temperature operation. The test results with various driving waveforms also provide references to the required consideration in engineering designs.

Excitation and relaxation of metastable atomic states in an active medium of a repetitively pulsed copper vapour laser

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

Bokhan, P A; Zakrevskii, D E; Lavrukhin, M A

2016-02-28

The influence of a pre-pulse population of copper atom metastable states and their sub-population at a current pulse edge on the copper vapour laser pulse energy is studied under optimal temperature conditions. Experiments have been performed with active elements of a commercial laser having an internal diameter of a discharge channel of 14 and 20 mm. It is found that at a pulse repetition frequency of 12 – 14 kHz, corresponding to a maximal output power, the reduction of the energy due to a residual population of metastable states is by an order of magnitude less than due to theirmore » sub-population at a current pulse edge. The modelling based on the experimental results obtained has shown that in the case of an active element with an internal diameter of 14 mm, a decrease in the pulse leading edge from ∼25 ns to 0.6 ns does not reduce the laser pulse energy up to the repetition frequency of ∼50 kHz at an average output power of 70 W m{sup -1} and efficiency of ∼11%. (lasers)« less

Determinants and Normal Values of Ascending Aortic Diameter by Age, Gender and Race/Ethnicity in the Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Turkbey, Evrim B.; Jain, Aditya; Johnson, Craig; Redheuil, Alban; Arai, Andrew E.; Gomes, Antoinette S.; Carr, James; Hundley, W. Gregory; Teixido-Tura, Gisela; Eng, John; Lima, Joao A.C.; Bluemke, David A.

2013-01-01

PURPOSE To determine the normal size and wall thickness of the ascending thoracic aorta (AA) and its relationship with cardiovascular risk factors in a large population-based study. MATERIALS AND METHODS The mean AA luminal diameter was measured in 3573 Multi-Ethnic Study of Atherosclerosis (MESA) participants (age: 45–84 years), using gradient echo phase contrast cine MRI. Multiple linear regression models were used to evaluate the associations between risk factors and AA diameter. The median and upper normal limit (95th percentile) was defined in a “healthy” subgroup as well as AA wall thickness. RESULTS The upper limits of body surface area indexed AA luminal diameter for age categories of 45–54, 55–64, 65–74, and 75–84 years are 21, 22, 22, and 28 mm/m2 in women and 20, 21, 22, 23 mm/m2 in men, respectively. The mean AA wall thickness was 2.8 mm. Age, gender and body surface area were major determinants of AA luminal diameter (~+1 mm/10 years; ~+1.9 mm in men than women; ~+1 mm/ 0.23 m2; p<0.001). The AA diameter in hypertensive subjects was +0.9 mm larger than in normotensives (p<0.001). CONCLUSION AA diameter increases gradually with aging for both genders, among all race/ethnicities. Normal value of AA diameter is provided. PMID:23681649

The cavernous sinus in cluster headache - a quantitative structural magnetic resonance imaging study.

PubMed

Arkink, Enrico B; Schoonman, Guus G; van Vliet, Jorine A; Bakels, Hannah S; Sneeboer, Marjolein Am; Haan, Joost; van Buchem, Mark A; Ferrari, Michel D; Kruit, Mark C

2017-03-01

Background It has been hypothesized that a constitutionally narrow cavernous sinus might predispose individuals to cluster headache. Cavernous sinus dimensions, however, have never been assessed. Methods In this case-control study, we measured the dimensions of the cavernous sinus, skull base, internal carotid and pituitary gland with high-resolution T2-weighted magnetic resonance imaging in 25 episodic, 24 chronic and 13 probable cluster headache patients, 8 chronic paroxysmal hemicrania patients and 22 headache-free controls. Dimensions were compared between groups, correcting for age, sex and transcranial diameter. Results On qualitative inspection, no relevant pathology or anatomic variants that were previously associated with cluster headache or chronic paroxysmal hemicranias were observed in the cavernous sinus or paracavernous structures. The left-to-right transcranial diameter at the temporal fossa level (mean ± SD) was larger in the headache groups (episodic cluster headache: 147.5 ± 7.3 mm, p = 0.044; chronic cluster headache: 150.2 ± 7.3 mm, p < 0.001; probable cluster headache: 146.0 ± 5.3 mm, p = 0.012; and chronic paroxysmal hemicrania: 145.2 ± 9.4 mm, p = 0.044) compared with controls (140.2 ± 8.0 mm). After adjusting for transcranial diameter and correcting for multiple comparisons, there were no differences in the dimensions of the cavernous sinus and surrounding structures between headache patients and controls. Conclusion Patients with cluster headache or chronic paroxysmal hemicrania had wider skulls than headache-free controls, but the proportional dimensions of the cavernous sinus were similar.

Aortic outflow occlusion predicts rupture of abdominal aortic aneurysm.

PubMed

Crawford, Jeffrey D; Chivukula, Venkat Keshav; Haller, Stephen; Vatankhah, Nasibeh; Bohannan, Colin J; Moneta, Gregory L; Rugonyi, Sandra; Azarbal, Amir F

2016-12-01

Current threshold recommendations for elective abdominal aortic aneurysm (AAA) repair are based solely on maximal AAA diameter. Peak wall stress (PWS) has been demonstrated to be a better predictor than AAA diameter of AAA rupture risk. However, PWS calculations are time-intensive, not widely available, and therefore not yet clinically practical. In addition, PWS analysis does not account for variations in wall strength between patients. We therefore sought to identify surrogate clinical markers of increased PWS and decreased aortic wall strength to better predict AAA rupture risk. Patients treated at our institution from 2001 to 2014 for ruptured AAA (rAAA) were retrospectively identified and grouped into patients with small rAAA (maximum diameter <6 cm) or large rAAA (>6 cm). Patients with large (>6 cm) non-rAAA were also identified sequentially from 2009 for comparison. Demographics, vascular risk factors, maximal aortic diameter, and aortic outflow occlusion (AOO) were recorded. AOO was defined as complete occlusion of the common, internal, or external iliac artery. Computational fluid dynamics and finite element analysis simulations were performed to calculate wall stress distributions and to extract PWS. We identified 61 patients with rAAA, of which 15 ruptured with AAA diameter <60 mm (small rAAA group). Patients with small rAAAs were more likely to have peripheral arterial disease (PAD) and chronic obstructive pulmonary disease (COPD) than were patients in the large non-rAAA group. Patients with small rAAAs were also more likely to have AOO compared with non-rAAAs >60 mm (27% vs 8%; P = .047). Among all patients with rAAAs, those with AOO ruptured at smaller mean AAA diameters than in patients without AOO (62.1 ± 11.8 mm vs 72.5 ± 16.4 mm; P = .024). PWS calculations of a representative small rAAA and a large non-rAAA showed a substantial increase in PWS with AOO. We demonstrate that AOO, PAD, and COPD in AAA are associated with rAAAs at smaller diameters. AOO appears to increase PWS, whereas COPD and PAD may be surrogate markers of decreased aortic wall strength. We therefore recommend consideration of early, elective AAA repair in patients with AOO, PAD, or COPD to minimize risk of early rupture. Copyright © 2016. Published by Elsevier Inc.

Management of colon stents based on Bernoulli's principle.

PubMed

Uno, Yoshiharu

2017-03-01

The colonic self-expanding metal stent (SEMS) has been widely used for "bridge to surgery" and palliative therapy. However, if the spread of SEMS is insufficient, not only can a decompression effect not be obtained but also perforation and obstructive colitis can occur. The mechanism of occurrence of obstructive colitis and perforation was investigated by flow dynamics. Bernoulli's principle was applied, assuming that the cause of inflammation and perforation represented the pressure difference in the proximal lumen and stent. The variables considered were proximal lumen diameter, stent lumen diameter, flow rate into the proximal lumen, and fluid density. To model the right colon, the proximal lumen diameter was set at 50 mm. To model the left-side colon, the proximal lumen diameter was set at 30 mm. For both the right colon model and the left-side colon model, the difference in pressure between the proximal lumen and the stent was less than 20 mmHg, when the diameter of the stent lumen was 14 mm or more. Both the right colon model and the left-side colon model were 30 mmHg or more at 200 mL s -1 when the stent lumen was 10 mm or less. Even with an inflow rate of 90-110 mL s -1 , the pressure was 140 mmHg when the stent lumen diameter was 5 mm. In theory, in order to maintain the effectiveness of SEMS, it is necessary to keep the diameter of the stent lumen at 14 mm or more.

Wear versus Thickness and Other Features of 5-Mrad Crosslinked UHMWPE Acetabular Liners

PubMed Central

Shen, Fu-Wen; Lu, Zhen

2010-01-01

Background The low wear rates of crosslinked polyethylenes provide the potential to use larger diameters to resist dislocation. However, this requires the use of thinner liners in the acetabular component, with concern that higher contact stresses will increase wear, offsetting the benefits of the crosslinking. Questions/purposes We asked the following questions: Is the wear of conventional and crosslinked polyethylene liners affected by ball diameter, rigidity of backing, and liner thickness? Are the stresses in the liner affected by thickness? Methods Wear rates were measured in a hip simulator and stresses were calculated using finite element modeling. Results Without crosslinking, the wear rate was 4% to 10% greater with a 36-mm diameter than a 28-mm diameter. With crosslinking, wear was 9% lower with a 36-mm diameter without metal backing and 4% greater with metal backing. Reducing the thickness from 6 mm to 3 mm increased the contact stress by 46%, but the wear rate decreased by 19%. Conclusions The reduction in wear with 5 Mrad of crosslinking was not offset by increasing the diameter from 28 mm to 36 mm or by using a liner as thin as 3 mm. Clinical Relevance The results indicate, for a properly positioned 5-Mrad crosslinked acetabular component and within the range of dimensions evaluated, neither wear nor stresses in the polyethylene are limiting factors in the use of larger-diameter, thinner cups to resist dislocation. PMID:20848244

Finite Element Analysis of Bone Stress around Micro-Implants of Different Diameters and Lengths with Application of a Single or Composite Torque Force.

PubMed

Lu, Ying-juan; Chang, Shao-hai; Ye, Jian-tao; Ye, Yu-shan; Yu, Yan-song

2015-01-01

Stress on the bone surrounding dental micro-implants affects implant success. To compare the stress on the bone surrounding a micro-implant after application of a single force (SF) of 200 g or a composite force (CF) of 200 g and 6 N.mm torque. Finite element models were developed for micro-implant diameters of 1.2, 1.6, and 2.0 mm, and lengths of 6, 8, 10, and 12 mm and either a SF or CF was applied. The maximum equivalent stress (Max EQS) of the bone surrounding the micro-implant was determined, and the relationships among type of force, diameter, and length were evaluated. The Max EQS of the CF exceeded that of the SF (P< 0.05). The effect of force on stress was related to implant diameter, but not to implant length. The larger CF led to greater instability of the micro-implant and the effect was most pronounced at an implant diameter of 1.2 mm. The use of implant diameters of 1.6 mm and 2.0 mm produced no significant difference in implant stability when either a CF or SF was applied. When considering the use of an implant to perform three-dimensional control on the teeth, the implant diameter chosen should be > 1.2 mm.

Finite Element Analysis of Bone Stress around Micro-Implants of Different Diameters and Lengths with Application of a Single or Composite Torque Force

PubMed Central

Lu, Ying-juan; Chang, Shao-hai; Ye, Jian-tao; Ye, Yu-shan; Yu, Yan-song

2015-01-01

Background Stress on the bone surrounding dental micro-implants affects implant success. Purpose To compare the stress on the bone surrounding a micro-implant after application of a single force (SF) of 200 g or a composite force (CF) of 200 g and 6 N.mm torque. Materials and Methods Finite element models were developed for micro-implant diameters of 1.2, 1.6, and 2.0 mm, and lengths of 6, 8, 10, and 12 mm and either a SF or CF was applied. The maximum equivalent stress (Max EQS) of the bone surrounding the micro-implant was determined, and the relationships among type of force, diameter, and length were evaluated. Results The Max EQS of the CF exceeded that of the SF (P< 0.05). The effect of force on stress was related to implant diameter, but not to implant length. The larger CF led to greater instability of the micro-implant and the effect was most pronounced at an implant diameter of 1.2 mm. The use of implant diameters of 1.6 mm and 2.0 mm produced no significant difference in implant stability when either a CF or SF was applied. Conclusion When considering the use of an implant to perform three-dimensional control on the teeth, the implant diameter chosen should be > 1.2 mm. PMID:26659581

Effect of baseplate size on primary glenoid stability and impingement-free range of motion in reverse shoulder arthroplasty.

PubMed

Chae, Soo-Won; Kim, Soung-Yon; Lee, Haea; Yon, Joung-Ro; Lee, Juneyoung; Han, Seung-Ho

2014-12-09

Use of a baseplate with a smaller diameter in reverse shoulder arthroplasty is increasing, especially in patients with a small glenoid or glenoid wear. However, the effect of a smaller baseplate on stability of the glenoid component has not been evaluated. Thus, the purpose of this study was to determine whether a smaller baseplate (25 mm) is beneficial to the initial stability of the glenoid component compared to that with a baseplate of a commonly used size (29 mm). Micromotion of glenoid components attached to 14 scapulae of fresh-frozen cadavers was measured and compared between 25- and 29-mm baseplates in biomechanical testing. Impingement-free range of motion in abduction, adduction, internal rotation, and external rotation was evaluated by using a simulated computer model constructed based on the same fresh-frozen cadavers used in biomechanical testing. Micromotion at the inferior third of the glenoid-glenosphere interface was higher in the 29-mm baseplate group than in the 25-mm baseplate group during both 0.7- and 1-body weight cyclic loading in biomechanical testing. Adduction deficit was smaller, and total impingement-free range of motion from abduction to adduction and rotation were greater in the 25-mm baseplate group than in the 29-mm baseplate group in the simulated computer model. Use of a baseplate with a smaller diameter (25 mm) in reverse shoulder arthroplasty is suitable for improving the primary stability of the glenoid component. With a smaller baseplate, impingement-free range of motion is optimized in a smaller glenoid.

Comparative in vitro flow study of 3 different Ex-PRESS miniature glaucoma device models.

PubMed

Estermann, Stephan; Yuttitham, Kanokwan; Chen, Julie A; Lee, On-Tat; Stamper, Robert L

2013-03-01

To determine the flow characteristics of the 3 different models of the Ex-PRESS miniature glaucoma device in a controlled laboratory study. The 3 different Ex-PRESS models (P-50, R-50, and P-200; Optonol Ltd; now Alcon Lab) were tested using a gravity-driven flow test. Three samples of each of the 3 Ex-PRESS models were subjected to a constant gravitational force of fluid at 5 different pressure levels (5 to 25 mm Hg). Four measurements per sample were taken at each pressure level. The main outcome measure was flow rate (Q) (µL/min). Resistance (R) was calculated by dividing pressure (P) by the measured flow (Q). The flow rate was primarily pressure dependent. The P-200 model (internal diameter 200 µm) showed a statistically significant higher flow rate and lower resistance compared with both the P-50 and R-50 models (internal diameter 50 µm) (P<0.0001). The P-50 and R-50 models demonstrated similar flow rates (P=0.08) despite their difference in tube length (2.64 vs. 2.94 mm). The 3 models of the Ex-PRESS mini shunt behaved in vitro as simple flow resistors by creating a relatively constant resistance to flow. Tube diameter was the only parameter with significant impact on flow and resistance. All models demonstrated flow rates per unit of pressure much higher than the outflow facility of a healthy human eye.

Effect of Electrical Current Stimulation on Pseudomonas Aeruginosa Growth

NASA Astrophysics Data System (ADS)

Alneami, Auns Q.; Khalil, Eman G.; Mohsien, Rana A.; Albeldawi, Ali F.

2018-05-01

The present study evaluates the effect of electrical current with different frequencies stimulation to kill pathogenic Pseudomonas aeruginosa (PA) bacteria in vitro using human safe level of electricity controlled by function generator. A wide range of frequencies has been used from 0.5 Hz-1.2 MHz to stimulate the bacteria at a voltage of 20 p-p volt for different periods of time (5 to 30) minutes. The culture of bacteria used Nickel, Nichrome, or Titanium electrode using agarose in phosphate buffer saline (PBS) and mixed with bacterial stock activated by trypticase soy broth (TSB). The results of frequencies between 0.5-1 KHz show the inhibition zone diameter of 20 mm in average at 30 minutes of stimulation. At frequencies between 3-60 KHz the inhibition zone diameter was only 10mm for 30 minutes of stimulation. While the average of inhibition zone diameter increased to more than 30mm for 30 minutes of stimulation at frequencies between 80-120 KHz. From this study we conclude that at specific frequency (resonance frequency) (frequencies between 0.5-1 KHz) there was relatively large inhibition zone because the inductive reactance effect is equal to the value of capacitive reactance effect (XC = XL). At frequencies over than 60 KHz, maximum inhibition zone noticed because the capacitance impedance becomes negligible (only the small resistivity of the bacterial internal organs).

Dosimetric evaluation of internal shielding in a high dose rate skin applicator

PubMed Central

Granero, Domingo; Perez-Calatayud, Jose; Carmona, Vicente; Pujades, M Carmen; Ballester, Facundo

2011-01-01

Purpose The Valencia HDR applicators are accessories of the microSelectron HDR afterloading system (Nucletron) shaped as truncated cones. The base of the cone is either 2 or 3 cm diameter. They are intended to treat skin lesions, being the typical prescription depth 3 mm. In patients with eyelid lesions, an internal shielding is very useful to reduce the dose to the ocular globe. The purpose of this work was to evaluate the dose enhancement from potential backscatter and electron contamination due to the shielding. Material and methods Two methods were used: a) Monte Carlo simulation, performed with the GEANT4 code, 2 cm Valencia applicator was placed on the surface of a water phantom in which 2 mm lead slab was located at 3 mm depth; b) radiochromic EBT films, used to verify the Monte Carlo results, positioning the films at 1.5, 3, 5 and 7 mm depth, inside the phantom. Two irradiations, with and without the lead shielding slab, were carried out. Results The Monte Carlo results showed that due to the backscatter component from the lead, the dose level raised to about 200% with a depth range of 0.5 mm. Under the lead the dose level was enhanced to about 130% with a depth range of 1 mm. Two millimeters of lead reduce the dose under the slab with about 60%. These results agree with film measurements within uncertainties. Conclusions In conclusion, the use of 2 mm internal lead shielding in eyelid skin treatments with the Valencia applicators were evaluated using MC methods and EBT film dosimetry. The minimum bolus thickness that was needed above and below the shielding was 0.5 mm and 1 mm respectively, and the shielding reduced the absorbed dose delivered to the ocular globe by about 60%. PMID:27877198

Bottle Characteristics of Topical International Glaucoma Medications versus Local Brands in Saudi Arabia

PubMed Central

Al-Jumaian, Nasser; Malik, Rizwan; Khandekar, Rajiv; Al-Humaidan, Abdullah; Al-Madany, Rana; Al-Qahtani, Reham; Altowairqi, Ahmed; Al-Theeb, Abdulwahab; Zaman, Babar; Al-Djasim, Leyla; Craven, E. Randy; Edward, Deepak P.

2016-01-01

WHAT IS KNOWN AND OBJECTIVE: Physical bottle characteristics differ of brand name topical glaucoma medications and local generic equivalents. This study compares the bottle characteristics of international topical glaucoma brands versus local brands from the Kingdom of Saudi Arabia. METHODS: Data were collected on bottle drum volume, drop volume, bottle squeezability, bottle tip diameter, labels and instructions, cap color coding, and clarity of the drug label. Density-based calculations of drops in bottle volume were assessed using an analytic balance. Bottle tip diameter was measured using 0.05 mm Vernier calipers. A Likert scale-based questionnaire was used to evaluate the subjective opinions of patients on bottle squeezability, clarity of usage and storage instructions, and the consistency of the cap color coding. RESULTS: The volumes of international brands were statistically significantly higher than the local brands (P < 0.001). A number of drops per bottle and tip diameter were comparable between the international local brands. Cap color coding was inconsistent for international and local brands. Patients were dissatisfied with the label font size. Patients reported that the international and local brands were similar in terms of the ease of opening the bottle, instilling a drop, and the clarity of the instructions; but the local brands were subjectively easier to squeeze than international brands. WHAT IS NEW AND CONCLUSIONS: This is the first study to compare bottle characteristics of local Saudi Arabia brands with international brands. The bottle characteristics and patient feedback were similar between the local and international topical glaucoma medications. However, there were differences between the local and international brands in drug volume, bottle squeezability. Hence, patient compliance and drop dosage may differ based on the origin of manufacture. PMID:27994392

[Experimental study of recovery force of surface-modified TiNi memory alloy rod].

PubMed

Wang, Aiyuan; Peng, Jiang; Zhang, Xian; Xu, Wenjin; Wang, Xing; Sun, Minxue; Lu, Shibi

2006-08-01

The recovery force of Ti-Nb coated and uncoated TiNi shape memory alloy rods was investigated. The rods were 6.0 mm, 6.5 mm and 7.0 mm in diameter respectively. The mean transition temperature was 33.0 degrees C. The rods were stored at -18 degrees C and pre-bent with a three-point bending fixture, the span was 20. 0 centimeters and the deflections were 5.0 mm, 10.0 mm, 15.0 mm and 20.0 mm, respectively. The rods were then heated in a constant temperature saline solution chamber. The experimental temperature was 37.0 C and 50.0 C respectively. The recovery force was measured in a constant displacement mode on biomaterial test machine. The results showed that the recovery force of the memory alloy rod increased with increasing recovery temperature, rod diameter and deformation of both Ti-Nb coated and uncoated surface. The recovery force of Ti-Nb coated rods of 6.0 and 6.5 millimeter in diameter was lower than the uncoated rods in the same diameter. However, the recovery force of 7.0-mm-diameter rods showed no significant difference between coated and uncoated surface.

1.65 mm diameter forward-viewing confocal endomicroscopic catheter using a flip-chip bonded electrothermal MEMS fiber scanner.

PubMed

Seo, Yeong-Hyeon; Hwang, Kyungmin; Jeong, Ki-Hun

2018-02-19

We report a 1.65 mm diameter forward-viewing confocal endomicroscopic catheter using a flip-chip bonded electrothermal MEMS fiber scanner. Lissajous scanning was implemented by the electrothermal MEMS fiber scanner. The Lissajous scanned MEMS fiber scanner was precisely fabricated to facilitate flip-chip connection, and bonded with a printed circuit board. The scanner was successfully combined with a fiber-based confocal imaging system. A two-dimensional reflectance image of the metal pattern 'OPTICS' was successfully obtained with the scanner. The flip-chip bonded scanner minimizes electrical packaging dimensions. The inner diameter of the flip-chip bonded MEMS fiber scanner is 1.3 mm. The flip-chip bonded MEMS fiber scanner is fully packaged with a 1.65 mm diameter housing tube, 1 mm diameter GRIN lens, and a single mode optical fiber. The packaged confocal endomicroscopic catheter can provide a new breakthrough for diverse in-vivo endomicroscopic applications.

Impact of vent pipe diameter on characteristics of waste degradation in semi-aerobic bioreactor landfill.

PubMed

Jiang, Guobin; Liu, Dan; Chen, Weiming; Ye, Zhicheng; Liu, Hong; Li, Qibin

2017-10-01

The evolution mechanism of a vent pipe diameter on a waste-stabilization process in semi-aerobic bioreactor landfills was analyzed from the organic-matter concentration, biodegradability, spectral characteristics of dissolved organic matter, correlations and principal-component analysis. Waste samples were collected at different distances from the vent pipe and from different landfill layers in semi-aerobic bioreactor landfills with different vent pipe diameters. An increase in vent pipe diameter favored waste degradation. Waste degradation in landfills can be promoted slightly when the vent pipe diameter increases from 25 to 50 mm. It could be promoted significantly when the vent pipe diameter was increased to 75 mm. The vent pipe diameter is important in waste degradation in the middle layer of landfills. The dissolved organic matter in the waste is composed mainly of long-wave humus (humin), short-wave humus (fulvic acid) and tryptophan. The humification levels of the waste that was located at the center of vent pipes with 25-, 50- and 75-mm diameters were 2.2682, 4.0520 and 7.6419 Raman units, respectively. The appropriate vent pipe diameter for semi-aerobic bioreactor landfills with an 800-mm diameter was 75 mm. The effect of different vent pipe diameters on the degree of waste stabilization is reflected by two main components. Component 1 is related mainly to the content of fulvic acid, biologically degradable material and organic matter. Component 2 is related mainly to the content of tryptophan and humin from the higher vascular plants.

[The tuberculin skin test in BCG-vaccinated individualse].

PubMed

Miret Cuadras, P; Pina Gutiérrez, J M

1998-10-01

The aim of this study was to evaluate the tuberculin skin test in individuals vaccinated with bacillus Calmette-Guérin (BCG) using 2 IU of RT-23. One hundred ninety-six individuals aged 22-40 years-old who had been vaccinated with BCG between 1965 and 1974 were enrolled along with 375 non-vaccinated individuals of the same age and with similar level of risk of infection. The positive predictive value of the test was assessed for three levels of response as indicated by areas of thickening in three diameters: 5, 10 and 15 mm. Vaccinated individuals with negative results were given a second skin test 7 days later to detect a booster effect. Positive diameters 5 mm were observed in 66% of the vaccinated individuals and 24% of the non-vaccinated subjects. Positive diameters 10 mm were observed in 51% of the vaccinated individuals and 19% of the non vaccinated ones. Positive diameters 15 mm were observed in 29% of the vaccinated subjects and in 13% of the non vaccinated ones. The differences were significant for all diameters. The positive predictive value of the test was 36.4% for a diameter 5 mm, 37.6% for diameter 10 mm and 44.8% for diameter 15 mm. The booster effect was detected in 25.8% of the vaccinated individuals who had tested negative at first. In vaccinated individuals, no guidelines can be established to guarantee that a positive reaction is due to infection by Mycobacterium tuberculosis infection, although the likelihood of infection (increased positive predictive value) increases with diameter. It is also impossible to fix a time limit. A second skin test is needed to detect a booster effect in all vaccinated individuals whose first test is negative.

Characterization of Navajo Sandstone concretions: Mars comparison and criteria for distinguishing diagenetic origins

NASA Astrophysics Data System (ADS)

Potter, Sally L.; Chan, Marjorie A.; Petersen, Erich U.; Dyar, M. Darby; Sklute, Elizabeth

2011-01-01

The eolian Jurassic Navajo Sandstone spheroidal hydrous ferric oxide (HFO) concretions are divided into two size classes: macro-concretions of > 5 mm diameter and micro-concretions of < 5 mm diameter. Three internal structural end-members of macro-concretions are described as rind, layered, and solid. Two end-members of micro-concretions are rind and solid. Chemical and mineralogical gradients (μm- to mm-scale) are identified with QEMSCAN (Quantitative Elemental Mineralogy using a SCANning electron microscope) and visible to near infrared (VNIR) reflectance spectroscopy. Three HFO phases are identified using VNIR reflectance spectroscopy. An amorphous HFO phase is typically located in the rinds. Goethite is present along interior edges of rinds and throughout the interiors of layered and solid concretions. Hematite is present in the centers of rind concretions. A synthesis of petrographic, mineralogical and chemical analyses suggests that concretions grow pervasively (as opposed to radially expanding). Our model proposes that concretions precipitate initially as an amorphous HFO that sets the radius and retains some original porosity. Subsequent precipitation fills remaining pore space with younger mineral phases. Inward digitate cement crystal growth corroborates concretion growth from a set radius toward the centers. Internal structure is modified during late stage precipitation that diffuses reactants through semi-permeable rinds and overprints the interiors with younger cements. Physical characterization of textures and minerals provides diagnostic criteria for understanding how similar concretions ("blueberries") form in Meridiani Planum, Mars. The analogous Navajo Sandstone concretions show similar characteristics of in situ self-organized spacing, spheroidal geometries, internal structures, conjoined forms, and precursor HFO phases that dehydrate to goethite or hematite. These characteristics indicate a common origin via groundwater diagenesis.

[Elective reconstruction of thoracoabdominal aortic aneurysm type IV by transabdominal approach].

PubMed

Marjanović, Ivan; Jevtić, Miodrag; Misović, Sidor; Sarac, Momir

2012-01-01

Thoracoabdominal aortic aneurysm (TAAA) type IV represents an aortic dilatation from the level of the diaphragmatic hiatus to the iliac arteries branches, including visceral branches of the aorta. In the traditional procedure of TAAA type IV repair, the body is opened using thoractomy and laparotomy in order to provide adequate exposure of the descending thoracic and abdominal aorta for safe aortic reconstruction. We reported a 71-year-old man with elective reconstruction of the TAAA type IV performed by transabdominal approach. Computed tomography scans angiography revealed a TAAA type IV with diameter of 62 mm in the region of celiac trunk andsuperior mesenteric artery branching, and the largest diameter of 75 mm in the infrarenal aortic level. The patient comorbidity included a chronic obstructive pulmonary disease and hypertension, therefore he was treated for a prolonged period. In preparation for the planned aortic reconstruction asymptomatic carotid disease (occlusion of the left internal carotid artery and subtotal stenosis of the right internal carotid artery) was diagnosed. Within the same intervention percutaneous transluminal angioplasty with stent placement in right internal carotid artery was made. In general, under endotracheal anesthesia and epidural analgesia, with transabdominal approach performed aortic reconstruction with tubular dakron graft 24 mm were, and reimplantation of visceral aortic branches into the graft performed. Postoperative course was uneventful, and the patient was discharged on the postoperative day 17. Control computed tomography scan angiography performed three months after the operation showed vascular state of the patient to be in order. Complete transabdominal approach to TAAA type IV represents an appropriate substitute for thoracoabdominal approach, without compromising safety of the patient. This approach is less traumatic, especially in patients with impaired pulmonary function, because there is no thoracotomy and any complications that could follow this approach.

The Big-Bubble Full Femtosecond Laser-Assisted Technique in Deep Anterior Lamellar Keratoplasty.

PubMed

Buzzonetti, Luca; Petrocelli, Gianni; Valente, Paola; Iarossi, Giancarlo; Ardia, Roberta; Petroni, Sergio; Parrilla, Rosa

2015-12-01

To describe the big-bubble full femtosecond laser-assisted (BBFF) technique, which could be helpful in standardizing the big-bubble technique in deep anterior lamellar keratoplasty (DALK). Ten eyes of 10 consecutive patients affected by keratoconus underwent the BBFF technique using the 150-kHz IntraLase femtosecond laser (Intra-Lase FS Laser; Abbott Medical Optics, Inc., Santa Ana, CA). A 9-mm diameter metal mask with a single fissure 0.7 mm wide oriented at the 12-o'clock position was positioned into the cone, over the laser glass. The laser performed a ring lamellar cut (internal diameter = 3 mm; external diameter = 8 mm) 100 µm above the thinnest point, with the photodisruption effectively occurring only in the corneal stroma corresponding to the fissure to create a deep stromal channel; subsequently, an anterior side cut created an arcuate incision, from the corneal surface to the deep stromal channel on the mask's opening site. The mask was removed and the laser performed a full lamellar cut 200 µm above the thinnest point to create a lamella. After the removal of the lamella, the air needle was inserted into the stromal channel and air was injected to achieve a big bubble. The big bubble was achieved in 9 eyes (all type 1 bubbles) and all procedures were completed as DALK. Preliminary results suggest that the BBFF technique could help in standardizing the big-bubble technique in DALK, reducing the "learning curve" for surgeons who approach this technique and the risks of intraoperative complications. Copyright 2015, SLACK Incorporated.

Evaluation of normal abdominal aortic diameters in the Indian population using computed tomography.

PubMed

Jasper, A; Harshe, G; Keshava, S N; Kulkarni, G; Stephen, E; Agarwal, S

2014-01-01

The aim of this study was to establish normal diameters for the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels in the Indian population and to study the variation in aortic diameters with age, sex, height, weight, body mass index (BMI), and body surface area (BSA). One hundred and forty-two patients who underwent helical contrast-enhanced computed tomography (CT) scans of the abdomen for non-cardiovascular reasons were recruited.. The mean internal diameters of the suprarenal and infrarenal abdominal aorta (maximum anteroposterior and transverse diameter) were measured at T12 and L3 vertebral levels and tabulated according to various age groups for both men and women. Pearson correlation coefficient was used to evaluate the correlation between aortic diameters, height, weight, BSA, and BMI. The mean diameters of the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels, in men were 19.0 ± 2.3 and 13.8 ± 1.9 mm and in women 17.1 ± 2.3 and 12.0 ± 1.6 mm, respectively. The aortic diameter progressively increased in caliber with increasing age of the patients and was smaller in women than men. A significant positive correlation was found in men between the suprarenal and infrarenal aortic diameters and weight, BSA, and BMI. In women, this correlation was significant in the infrarenal aorta but not in the suprarenal aorta. We obtained a set of normal values for the abdominal aorta in the Indian population. The aortic diameters correlated with age, gender, and body size of the patients as seen with previously published data in the Western population. A brief comparison of data between Indian and Western population showed that the values obtained were less than published elsewhere and hence, this should be considered while formulating intervention protocols.

Advanced designs for non-imaging submillimeter-wave Winston cone concentrators

NASA Astrophysics Data System (ADS)

Nelson, A. O.; Grossman, E. N.

2014-05-01

We describe the design and simulation of several non-imaging concentrators designed to couple submillimeter wavelength radiation from free space into highly overmoded, rectangular, WR-10 waveguide. Previous designs are altered to improve the uniformity of efficiency rather than the efficiency itself. The concentrators are intended for use as adapters between instruments using overmoded WR-10 waveguide as input or output and sources propagating through free space. Previous simulation and measurement have shown that the angular response is primarily determined by the Winston cone and is well predicted by geometric optics theory while the efficiencies are primarily determined by the transition section. Additionally, previous work has shown insensitivity to polarization, orientation and beam size. Several separate concentrator designs are studied, all of which use a Winston cone (also known as a compound parabolic concentrator) with an input diameter ranging from 4 mm to 16 mm, and "throat" diameters of less than 0.5 mm to 4 mm as the initial interface. The use of various length adiabatic circular-to-rectangular transition sections is investigated, along with the effect of an additional, 25 mm waveguide section designed to model the internal waveguide of the power meter. Adapters without a transition section and a rectangular Winston cone throat aperture and double cone configurations are also studied. Adapters are analyzed in simulation for consistent efficiency across the opening aperture.

The application research of microwave nondestructive testing and imaging based on ω-k algorithm

NASA Astrophysics Data System (ADS)

Qi, Shengxiang; Ren, Jian; Gu, Lihua; Xu, Hui; Wang, Yuanbo

2017-07-01

The Bridges had collapsed accidents in recent years due to bridges quality problems. Therefore, concretes nondestructive testing are particularly important. At present, most applications are Ground Penetrating Radar (GPR) technology in the detection of reinforced concretes structure. GPR are used the pulse method which alongside with definitive advantages, but the testing of the internal structure of the small thickness concretes has very low resolution by this method. In this paper, it's the first time to use the ultra-wideband (UWB) stepped frequency conversion radar above problems. We use vector network analyzer and double ridged horn antenna microwave imaging system to test the reinforced concretes block. The internal structure of the concretes is reconstructed with a method of synthetic aperture of ω-k algorithm. By this method, the depth of the steel bar with the diameter of 1cm is shown exactly in the depth of 450mm×400mm×500mm and the depth error do not exceed 1cm.

40 CFR Appendix B to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

Code of Federal Regulations, 2012 CFR

2012-07-01

... Analysis in Manufacturing and Assembly Processes (Process FMEA). Revised January 2009. SAE International. 3... submitted to demonstrate it can be used safely in this end-use. CFC-11, CFC-12, R-502 Industrial Process... Outside diameter of 20.955 +0/−0.127 mm (0.825 +0/−0.005 inches) and right-hand thread direction for CO2...

Optimal radial force and size for palliation in gastroesophageal adenocarcinoma: a comparative analysis of current stent technology.

PubMed

Mbah, Nsehniitooh; Philips, Prejesh; Voor, Michael J; Martin, Robert C G

2017-12-01

The optimal use of esophageal stents for malignant and benign esophageal strictures continues to be plagued with variability in pain tolerance, migration rates, and reflux-related symptoms. The aim of this study was to evaluate the differences in radial force exhibited by a variety of esophageal stents with respect to the patient's esophageal stricture. Radial force testing was performed on eight stents manufactured by four different companies using a hydraulic press and a 5000 N force gage. Radial force was measured using three different tests: transverse compression, circumferential compression, and a three-point bending test. Esophageal stricture composition and diameters were measured to assess maximum diameter, length, and proximal esophageal diameter among 15 patients prior to stenting. There was a statistically significant difference in mean radial force for transverse compression tests at the middle (range 4.25-0.66 newtons/millimeter N/mm) and at the flange (range 3.32-0.48 N/mm). There were also statistical differences in mean radial force for circumferential test (ranged from 1.19 to 10.50 N/mm, p < 0.001) and the three-point bending test (range 0.08-0.28 N/mm, p < 0.001). In an evaluation of esophageal stricture diameters and lengths, the smallest median diameter of the stricture was 10 mm (range 5-16 mm) and the median proximal diameter normal esophagus was 25 mm (range 22-33 mm), which is currently outside of the range of stent diameters. Tested stents demonstrated significant differences in radial force, which provides further clarification of stent pain and intolerance in certain patients, with either benign or malignant disease. Similarly, current stent diameters do not successfully exclude the proximal esophagus, which can lead to obstructive-type symptoms. Awareness of radial force, esophageal stricture composition, and proximal esophageal diameter must be known and understood for optimal stent tolerance.

Minimization of skin incisions at stripping by Mayo of large-diameter veins.

PubMed

Tsukanov, Yu

2018-03-15

To study the possibility of minimization of the skin incisions up to a puncture size at stripping by Mayo with the use of the stripper with an oval-ring head for large-diameter veins. The problem is solved due to the geometrical changing of the stripper head from a round to an oval one. The laboratory experiment showed that with a vein diameter of 10-20 mm the total cross-sectional area of its walls constituted 13.61 mm2, with a diameter of more than 20 mm it was 19.98 mm2. There were designed three types of the external dimensions for the stripper: 3.0 х 6.0 mm; 3,5 х 7.0 mm and 4.0 х 8.0 mm. From 1997 to 2017 the stripper with an oval-ring head was used in 1274 patients (male, n=421; female, n=853) for treating 1832 lower limbs. Average age was 46.4±12.3 years (range, 29 to 73). GSV and SSV stripping was performed in 1165 and 137 cases respectively in patients with the trunk diameter of more than 10 mm, severe vein tortuosity, for a vein located immediately under the skin, as well as for patients with the history of thrombophlebitis. The pain level in the 1st evening after the operation was 1.59, on the 7th day it decreased to 0.12 according to VAS-10. The motion activity level in the 1st evening after the operation was 7.24, on the 7th day it decreased to 9.96 according to VAS-10. All patients had primary wound healing. Hematomas along the location of the eliminated veins were of a moderate nature and resolved, on average, within 17 days. With the GSV diameter of 10-20 mm the skin scars were of 2.93 mm (95% CI: 3.09 mm - 4.47 mm), with the GSV diameter of more than 20 mm the skin scars were of 4.10 mm (95% CI: 4.01 mm - 5.07 mm). After 3 months 1102 patients (86,5%) were very satisfied and 172 (13,5%) were just satisfied with the performed operation. The use of the proposed stripper with an oval-ring head in patients with large-diameter subcutaneous trunks leads to the minimization of the skin incisions up to the punctures and, in general, makes the surgery significantly less traumatic, providing a quick recovery and minimization of the skin scars.

Experimental investigation of two-phase flow patterns in minichannels at horizontal orientation

NASA Astrophysics Data System (ADS)

Saljoshi, P. S.; Autee, A. T.

2017-09-01

Two-phase flow is the simplest case of multiphase flow in which two phases are present for a pure component. The mini channel is considered as diameter below 3.0-0.2 mm and conventional channel is considered diameter above 3.0 mm. An experiment was conducted to study the adiabatic two-phase flow patterns in the circular test section with inner diameter of 1.1, 1.63, 2.0, 2.43 and 3.0 mm for horizontal orientation using air and water as a fluid. Different types of flow patterns found in the experiment. The parameters that affect most of these patterns and their transitions are channel size, phase superficial velocities (air and liquid) and surface tension. The superficial velocity of liquid and gas ranges from 0.01 to 66.70 and 0.01 to 3 m/s respectively. Two-phase flow pattern photos were recorded using a high speed CMOS camera. In this experiment different flow patterns were identified for different tube diameters that confirm the diameter effect on flow patterns in two-phase flows. Stratified flow was not observed for tube diameters less than 3.0 mm. Similarly, wavy-annular flow pattern was not observed in 1.6 and 1.0 mm diameter tubes due to the surface-tension effect and decrease in tube diameter. Buoyancy effects were clearly visible in 2.43 and 3.0 mm diameter tubes flow pattern. It has also observed that as the test-section diameter decreases the transition lines shift towards the higher gas and liquid velocity. However, the result of flow pattern lines in the present study has good agreement with the some of the existing flow patterns maps.

Sealing vessels up to 7 mm in diameter solely with ultrasonic technology.

PubMed

Timm, Richard W; Asher, Ryan M; Tellio, Karalyn R; Welling, Alissa L; Clymer, Jeffrey W; Amaral, Joseph F

2014-01-01

Ultrasonic energy is a mainstay in the armamentarium of surgeons, providing multifunctionality, precision, and control when dissecting and sealing vessels up to 5 mm in diameter. Historically, the inability to seal vessels in the 5-7 mm range has been perceived as an inherent limitation of ultrasonic technology. The purpose of this study was to evaluate sealing of vessels up to 7 mm in diameter with an ultrasonic device that modulates energy delivery during the sealing period. In ex vivo benchtop and in vivo acute and survival preclinical models, a new ultrasonic device, Harmonic ACE(®)+7 Shears (Harmonic 7), was compared with advanced bipolar devices in sealing vessels 1-7 mm in diameter with respect of burst pressure, seal reliability, and seal durability. Lateral thermal damage and transection time were also evaluated. Ex vivo tests of Harmonic 7 demonstrated significantly greater median burst pressures than an advanced bipolar device both for vessels <5 mm in diameter (1,078 mmHg and 836 mmHg, respectively, P=0.046) and for those in the range of 5-7 mm (1,419 mmHg and 591 mmHg, P<0.001). In vivo tests in porcine and caprine models demonstrated similar rates of hemostasis between Harmonic 7 and advanced bipolar devices, with high success rates at initial transection and seal durability of 100% after a 30-day survival period. Sealing 5-7 mm vessels is not a limitation of the type of energy used but of how energy is delivered to tissue. These studies document the ability of ultrasonic energy alone to reliably seal large vessels 5-7 mm in diameter, with significantly greater burst pressure observed in in vitro studies than those observed with an advanced bipolar technology when energy delivery is modulated during the sealing cycle. Furthermore, the seals created in 5-7 mm vessels are shown to be reliable and durable in in vivo preclinical studies.

Comparison of urethral diameters for calculating the urethral dose after permanent prostate brachytherapy.

PubMed

Tanaka, Osamu; Hayashi, Shinya; Matsuo, Masayuki; Nakano, Masahiro; Kubota, Yasuaki; Maeda, Sunaho; Ohtakara, Kazuhiro; Deguchi, Takashi; Hoshi, Hiroaki

2007-08-01

No studies have yet evaluated the effects of a dosimetric analysis for different urethral volumes. We therefore evaluated the effects of a dosimetric analysis to determine the different urethral volumes. This study was based on computed tomography/magnetic resonance imaging (CT/MRI) combined findings in 30 patients who had undergone prostate brachytherapy. Postimplant CT/MRI scans were performed 30 days after the implant. The urethra was contoured based on its diameter (8, 6, 4, 2, and 0 mm). The total urethral volume-in cubic centimeters [UrV150/200(cc)] and percent (UrV150%/200%), of the urethra receiving 150% or 200% of the prescribed dose-and the doses (UrD90/30/5) in Grays to 90%, 30%, and 5% of the urethral volume were measured based on the urethral diameters. The UrV150(cc) and UrD30 were statistically different between the of 8-, 6-, 4-, 2-, and 0-mm diameters, whereas the UrD5 was statistically different only between the 8-, 6-, and 4-mm diameters. Especially for UrD5, there was an approximately 40-Gy difference between the mean values for the 8- and 0-mm diameters. We recommend that the urethra should be contoured as a 4- to 6-mm diameter circle or one side of a triangle of 5-7 mm. By standardizing the urethral diameter, the urethral dose will be less affected by the total urethral volume.

Numerical analysis of specific absorption rate in the human head due to a 13.56 MHz RFID-based intra-ocular pressure measurement system

NASA Astrophysics Data System (ADS)

Hirtl, Rene; Schmid, Gernot

2013-09-01

A modern wireless intra-ocular pressure monitoring system, based on 13.56 MHz inductively coupled data transmission, was dosimetrically analyzed with respect to the specific absorption rate (SAR) induced inside the head and the eye due to the electromagnetic field exposure caused by the reader antenna of the transmission system. The analysis was based on numerical finite difference time domain computations using a high resolution anatomical eye model integrated in a modern commercially available anatomical model of a male head. Three different reader antenna configurations, a 7-turn elliptic (30 mm × 50 mm) antenna at 12 mm distance from the eye, a flexible circular antenna (60 mm diameter, 8 turns on 2 mm substrate) directly attached to the skin, and a circular 7-turn antenna (30 mm diameter at 12 mm distance to the eye) were analyzed, respectively. Possible influences of the eye-lid status (closed or opened) and the transponder antenna contained in a contact lens directly attached to the eye were taken into account. The results clearly demonstrated that for typical reader antenna currents required for proper data transmission, the SAR values remain far below the limits for localized exposure of the head, as defined by the International Commission for Non-Ionizing Radiation Protection. Particularly the induced SAR inside the eye was found to be substantially (orders of magnitudes for typical reader antenna currents in the order of 1 A turn) below values which have been reported to be critical with respect to thermally induced adverse health effects in eye tissues.

Ultrathin forward-imaging short multimode fiber probe for full-field optical coherence microscopy

NASA Astrophysics Data System (ADS)

Sato, Manabu; Saito, Daisuke; Shouji, Kou; Kurotani, Reiko; Abe, Hiroyuki; Nishidate, Izumi

2016-12-01

To extend the applications of optical coherence tomography (OCT) to the fields of physiology and clinical medicine, less invasive, robust, and reliable optical probes are required. Thus, we demonstrate an ultrathin forward-imaging short multimode fiber (SMMF) optical coherence microscopy (OCM) probe with a 50 μm core diameter, 125 μm total diameter, and 5.12 mm length. Imaging conditions and magnification were analyzed, and they correspond closely to the measured results. The dispersion of the SMMF was investigated, and the modal dispersion coefficient was found to be 2.3% of the material dispersion coefficient. The axial resolution was minimized at 2.15 μm using a 0.885-mm-thick dispersion compensator. The lateral resolution was evaluated to be 4.38 μm using a test pattern. The contrast of the OCM images was 5.7 times higher than that of the signal images owing to the coherence gate. The depth of focus and diameter of the field of view were measured to be 60 μm and 40-50 μm, respectively. OCM images of the dried fins of small fish (Medaka) were measured and internal structures could be recognized.

Assessing MMOD Impacts on Seal Performance

NASA Technical Reports Server (NTRS)

deGroh, Henry C., III; Daniels, C.; Dunlap, P.; Steinetz, B.

2007-01-01

The elastomer seal needed to seal in cabin air when NASA s Crew Exploration Vehicle is docked is exposed to space prior to docking. While open to space, the seal might be hit by orbital debris or meteoroids. The likelihood of damage of this type depends on the size of the particle. Our campaign is designed to find the smallest particle that will cause seal failure resulting in loss of mission. We will then be able to estimate environmental risks to the seal. Preliminary tests indicate seals can withstand a surprising amount of damage and still function. Collaborations with internal and external partners are in place and include seal leak testing, modeling of the space environment using a computer code known as BUMPER, and hypervelocity impact (HVI) studies at Caltech. Preliminary work at White Sands Test Facility showed a 0.5 mm diameter HVI damaged areas about 7 times that diameter, boring deep (5 mm) into elastomer specimens. BUMPER simulations indicate there is a 1 in 1440 chance of getting hit by a particle of diameter 0.08 cm for current Lunar missions; and 0.27 cm for a 10 year ISS LIDS seal area exposure.

Ignition and growth modeling of detonation reaction zone experiments on single crystals of PETN and HMX

NASA Astrophysics Data System (ADS)

White, Bradley W.; Tarver, Craig M.

2017-01-01

It has long been known that detonating single crystals of solid explosives have much larger failure diameters than those of heterogeneous charges of the same explosive pressed or cast to 98 - 99% theoretical maximum density (TMD). In 1957, Holland et al. demonstrated that PETN single crystals have failure diameters of about 8 mm, whereas heterogeneous PETN charges have failure diameters of less than 0.5 mm. Recently, Fedorov et al. quantitatively determined nanosecond time resolved detonation reaction zone profiles of single crystals of PETN and HMX by measuring the interface particle velocity histories of the detonating crystals and LiF windows using a PDV system. The measured reaction zone time durations for PETN and HMX single crystal detonations were approximately 100 and 260 nanoseconds, respectively. These experiments provided the necessary data to develop Ignition and Growth (I&G) reactive flow model parameters for the single crystal detonation reaction zones. Using these parameters, the calculated unconfined failure diameter of a PETN single crystal was 7.5 +/- 0.5 mm, close to the 8 mm experimental value. The calculated failure diameter of an unconfined HMX single crystal was 15 +/- 1 mm. The unconfined failure diameter of an HMX single crystal has not yet been determined precisely, but Fedorov et al. detonated 14 mm diameter crystals confined by detonating a HMX-based plastic bonded explosive (PBX) without initially overdriving the HMX crystals.

Aortic elongation in aortic aneurysm and dissection: the Tübingen Aortic Pathoanatomy (TAIPAN) project.

PubMed

Krüger, Tobias; Sandoval Boburg, Rodrigo; Lescan, Mario; Oikonomou, Alexandre; Schneider, Wilke; Vöhringer, Luise; Lausberg, Henning; Bamberg, Fabian; Blumenstock, Gunnar; Schlensak, Christian

2018-01-24

To study the lengths and diameters of aortic segments in healthy and diseased aortas and to assess the role of aortic elongation in Type A aortic dissection (TAD) prediction. Ectasia and aneurysm were defined by ascending aorta diameters of 45-54 mm and ≥55 mm, respectively. Computed tomography angiography studies of 256 healthy, 102 ectasia, 38 aneurysm, 17 pre-TAD and 166 TAD aortas were analysed using curved multiplanar reformats. The study groups were structurally equal. The diameter of the ascending aorta was 35 mm in the control group and was larger (P < 0.001) in the pre-TAD (43 mm) and TAD (56 mm) groups. The length of the ascending aorta from the aortic annulus to the brachiocephalic trunk was 92 mm in the control group, 113 mm in the ectasia group, 120 mm in the aneurysm group and 111 mm and 118 mm in the pre-TAD and TAD groups (all P < 0.001 compared with the control group). An ascending aorta length of 120 mm was exceeded in 2% of the control group, 31% of the ectasia group, 50% of the aneurysm group, 24% of the pre-TAD group and 48% of the TAD group. The correlation between the diameter and the length of the ascending aorta was r = 0.752; therefore, both parameters must be examined separately. A score considering both parameters identified 23.5% of pre-TAD patients, significantly more than the diameter alone, and 31.4% of ectasia aortas were elongated. Patients with ectatic (45-54 mm diameter) and elongated (≥120 mm) ascending aortas represent a high-risk subpopulation for TAD. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Participation in multilateral effort to develop high performance integrated CPC evacuated collectors

NASA Astrophysics Data System (ADS)

Winston, R.; Ogallagher, J. J.

1992-05-01

The University of Chicago Solar Energy Group has had a continuing program and commitment to develop an advanced evacuated solar collector integrating nonimaging concentration into its design. During the period from 1985-1987, some of our efforts were directed toward designing and prototyping a manufacturable version of an Integrated Compound Parabolic Concentrator (ICPC) evacuated collector tube as part of an international cooperative effort involving six organizations in four different countries. This 'multilateral' project made considerable progress towards a commercially practical collector. One of two basic designs considered employed a heat pipe and an internal metal reflector CPC. We fabricated and tested two large diameter (125 mm) borosilicate glass collector tubes to explore this concept. The other design also used a large diameter (125 mm) glass tube but with a specially configured internal shaped mirror CPC coupled to a U-tube absorber. Performance projections in a variety of systems applications using the computer design tools developed by the International Energy Agency (IEA) task on evacuated collectors were used to optimize the optical and thermal design. The long-term goal of this work continues to be the development of a high efficiency, low cost solar collector to supply solar thermal energy at temperatures up to 250 C. Some experience and perspectives based on our work are presented and reviewed. Despite substantial progress, the stability of research support and the market for commercial solar thermal collectors were such that the project could not be continued. A cooperative path involving university, government, and industrial collaboration remains the most attractive near term option for developing a commercial ICPC.

Infraorbital foramen: horizontal location in relation to ala nasi.

PubMed

Takahashi, Yasuhiro; Kakizaki, Hirohiko; Nakano, Takashi

2011-01-01

To examine the horizontal location of the infraorbital foramen in relation to the ala nasi. Fifty-six orbits of 28 Japanese cadavers (18 male and 10 female cadavers; average death age, 79.7 years), fixed in 10% buffered formalin, were used. The horizontal distance from the vertical line through the lateral margin of the ala nasi to the medial margin of the infraorbital foramen (the horizontal distance) and the transverse diameter of the infraorbital foramen (the transverse diameter) were examined. Values were compared between genders and sides using Student's t test. The mean horizontal distance was 4.9 mm, with no significant difference between genders (male, 5.2 mm; female, 4.4 mm; p = 0.150) or sides (right, 4.9 mm; left, 4.9 mm; p = 0.944). The mean transverse diameter was 5.5 mm. Although there was no significant difference in this diameter between sides (right, 5.3 mm; left, 5.6 mm; p = 0.358), there was a significant difference between genders (male, 5.7 mm; female, 5.1 mm; p = 0.033). The horizontal distance had no gender difference. This value is available irrespective of gender in surgery.

Argon hollow cathode. M.S. Thesis; [propellants for ion bombardment thrusters

NASA Technical Reports Server (NTRS)

Rehn, L. A.

1976-01-01

An interest in alternate propellants for ion-bombardment thrusters, together with ground applications of this technology, has prompted consideration of argon. Several variations of conventional hollow cathode designs were tried, but the bulk of the testing used a hollow tube with an internal tungsten emitter and an orifice at one end. The optimum cathode tube diameter was found to be in the range of 1.0-2.5 cm, somewhat larger than those used for cesium and mercury. Optimum orifice diameter depended on operating conditions, and varied from 0.5 to 5 mm. Biasing the internal emitter negative relative to the cathode chamber reduced the external coupling voltage and should therefore improve orifice lifetime. The expected effect of this bias on emitter lifetime was less clear. Lifetime tests were not conducted as part of this investigation, but several designs show promise of long lifetime in specific applications.

Natural history of the ascending aorta after aortic valve replacement: risk factor analysis for late aortic complications after aortic valve replacement.

PubMed

Tsutsumi, Koji; Hashizume, Kenichi; Inoue, Yoshito

2016-05-01

The purpose of this study was to clarify the natural history of the ascending aorta and to identify risk factors for late ascending aortic events after first isolated aortic valve replacement (AVR). A total of 287 patients undergoing AVR were enrolled. The patients were categorized into two groups based on the diameter of the ascending aorta at the time of AVR, as determined by computed tomography: Group A (n = 233) was defined as an ascending aortic diameter <40 mm, and Group B (n = 54) was defined as an ascending aortic diameter ≥40 mm. The mean follow-up period was 7.6 years. The baseline diameter of the ascending aorta was 31.4 ± 4.8 mm in Group A and 44.7 ± 4.2 mm in Group B. These values increased to 35.9 ± 7.4 mm in Group A and 50.1 ± 7.3 mm in Group B during the follow-up period (P < 0.001). Ten patients had acute type A aortic dissection (Group A: 1 patient vs. Group B: 9 patients; P < 0.001), and three patients had enlargement of the ascending aorta to ≥55 mm in diameter (Group A: 1 patient vs. Group B: 2 patients). Multivariate analysis revealed that the baseline ascending aortic diameter was the only significant risk factor for developing late ascending aortic events (P < 0.001). AVR alone may not prevent further enlargement of the ascending aorta. An ascending aorta ≥40 mm in diameter at the time of AVR increased the risk of late ascending aortic events.

Recent Shuttle Post Flight MMOD Inspection Highlights

NASA Technical Reports Server (NTRS)

Hyed, James L.; Christiansen, Eric L.; Lear, Dana M.; Herrin, Jason S.

2009-01-01

Post flight inspections on the Space Shuttle Atlantis conducted after the STS-11.5 mission revealed a 0.11 inch (2.8 mm) hole in the outer face sheet of the starboard payload bay door radiator panel #4. The payload bay door radiators in this region are 0.5 inch (12.7 mm) thick aluminum honeycomb with 0.011 in (0.279 mm) thick aluminum face sheets topped with 0.005 in (0.127 mm) silver-Teflon tape. Inner face sheet damage included a 0.267 in (6.78 mm) long through crack with measureable deformation in the area of 0.2 in (5.1 mm). There was also a 0.031 in (0.787 nun) diameter hole in the rear face sheet. A large approximately l in (25 mm) diameter region of honeycomb was also destroyed. Since the radiators are located on the inside of the shuttle payload bay doors which are closed during ascent and reentry, the damage could only have occurred during the on-orbit portion of the mission. During the August 2007 STS-118 mission to the International Space Station, a micro-meteoroid or orbital debris (MMOD) particle impacted and completely penetrated one of shuttle Endeavour's radiator panels and the underlying thermal control system (TCS) blanket, leaving deposits on (but no damage to) the payload bay door. While it is not unusual for shuttle orbiters to be impacted by small MMOD particles, the damage from this impact is larger than any previously seen on the shuttle radiator panels. One of the largest impacts ever observed on a crew module window occurred during the November 2008 STS-126 mission to the International Space Station. Damage to the window was documented by the crew on orbit. Post flight inspection revealed a 0.4 in (10.8 mm) crater in the window pane, with a depth of 0.03 in (0.76 mm). The window pane was replaced due to the damage caused by this impact. Analysis performed on residue contained in dental mold impressions taken of the site indicated that a meteoroid particle produced this large damage site. The post flight inspection after the subsequent mission, STS-119 in March of 2009, produced a large MMOD impact feature in a wing leading edge reinforced carbon-carbon panel. The crater measured 0.18 in (4.5 nun) in diameter and was nearly 0.037 in (0.93 nun) deep. The thickness of the silicon carbide coating that protects the carbon substrate is nominally 0.02 in (0.5 nun) to 0.04 in (1 mm), making this a significant impact into the RCC. The damage occurred on the upper surface of the panel, which experiences lower heat loads on re-entry. This poster will document the data collected from the impact sites and will include results of the Scanning Electron Microscope/Energy Dispersive X-ray (SEM/EDX) analysis. Evidence will be presented that suggests a source of the impacts.

Simulation on Effect of Preform Diameter in Injection Stretch Blow Molding

NASA Astrophysics Data System (ADS)

Tan, Z. Q.; Rosli, Nurrina; Oktaviandri, Muchamad

2018-03-01

Polyethylene terephthalate (PET) is the most common material of resin for manufacturing plastic bottle by injection stretch blow molding due to its excellent properties. As various issues of health and environmental hazards due to the PET use have risen, PET bottle manufacture may be improved by minimizing the wall thickness to reduce the PET use. One of the critical qualifications of the manufacturing process which lead to the wall thickness distribution is the initial preform diameter. In this project, we used the ANSYS Polyflow with aim to evaluate the wall thickness distribution of PET bottle for different diameter of initial preform. As a result, only 4 mm preform diameter presented wall thickness below than 1 mm. On the other hand, at least 6 mm preform diameter can permit the wall thickness 1.3 mm i.e. at the shoulder area.

Angiographic Anatomy of External Iliac Arteries in the Sheep.

PubMed

Joscht, M; Martin, M; Henin, M; Nisolle, J F; Kirschvink, N; Dugdale, A; Godart, B; Coulon, H; Simon, V; Hontoir, F; Graffin, R; De Raeve, Y; Vandeweerd, J M

2016-12-01

External iliac artery atherosclerotic disease and aneurism occur in man. For treatment, imaging is required to facilitate minimally invasive introduction and advancement of stents within the intended vessels. Sheep are commonly used to test and improve stents. However, little information is published regarding the angiographic anatomy of the iliac arteries in the ovine species. The objective of this study was to describe the angiographic anatomy of the iliac arteries in the sheep. Computed tomography (CT) angiography and gross anatomical dissection were performed in, respectively, 10 and 43 adult ewes. Diameters and lengths of the arteries were measured. In comparison with man, salient anatomical differences were identified in the sheep: (1) the absence of common iliac arteries, (2) the common trunk at the origin of internal iliac arteries and (3) the location of the bifurcation of the external iliac arteries into femoral arteries in the pelvis (not in the limb). External iliac arteries in this series of sheep were 86 mm long in average and had a mean diameter of 7.5 mm. Lengths of arteries are only slightly different between man and sheep, while diameters are rather similar. Therefore, the sheep model appears to be sufficiently similar to man to test stent properties. This study provides useful reference images and measures of lengths and diameters of relevant arteries that could be applied to research with ovine models. © 2015 Blackwell Verlag GmbH.

Optimization of a rod pinch diode radiography source at 2.3 MV

NASA Astrophysics Data System (ADS)

Menge, P. R.; Johnson, D. L.; Maenchen, J. E.; Rovang, D. C.; Oliver, B. V.; Rose, D. V.; Welch, D. R.

2003-08-01

Rod pinch diodes have shown considerable capability as high-brightness flash x-ray sources for penetrating dynamic radiography. The rod pinch diode uses a small diameter (0.4-2 mm) anode rod extended through a cathode aperture. When properly configured, the electron beam born off of the aperture edge can self-insulate and pinch onto the tip of the rod creating an intense, small x-ray source. Sandia's SABRE accelerator (2.3 MV, 40 Ω, 70 ns) has been utilized to optimize the source experimentally by maximizing the figure of merit (dose/spot diameter2) and minimizing the diode impedance droop. Many diode parameters have been examined including rod diameter, rod length, rod material, cathode aperture diameter, cathode thickness, power flow gap, vacuum quality, and severity of rod-cathode misalignment. The configuration producing the greatest figure of merit uses a 0.5 mm diameter gold rod, a 6 mm rod extension beyond the cathode aperture (diameter=8 mm), and a 10 cm power flow gap to produce up to 3.5 rad (filtered dose) at 1 m from a 0.85 mm x-ray on-axis spot (1.02 mm at 3° off axis). The resultant survey of parameter space has elucidated several physics issues that are discussed.

Effect of tracheal tube cuff shape on fluid leakage across the cuff: an in vitro study.

PubMed

Dave, M H; Frotzler, A; Spielmann, N; Madjdpour, C; Weiss, M

2010-10-01

This study compared the fluid leakage in the new 'tapered' shaped against the classic 'cylindrical' shaped tracheal tube cuffs when placed in different sized tracheas. The 7.5 mm internal diameter (ID) tracheal tube cuffs-Tapered Seal Guard (TSG), Standard Seal Guard (SSG), Hi-Lo, Microcuff, Ruesch, and Portex Profile-were compared in an in vitro apparatus. Vertical artificial tracheas with 16, 20, and 22 mm ID were intubated, 5 ml clear water was applied above the unlubricated tube cuffs, and fluid leakage was measured up to 60 min. Data of tapered vs non-tapered tube cuffs (16 observations) were compared for each tracheal diameter using the Mann-Whitney test. Median (range) fluid leakage (ml) at 60 min was 2.14 (0.05-4.88), 1.14 (0.00-4.84), and 0.13 (0.00-1.32), respectively, for 16, 20, and 22 mm tracheas in the TSG tube studies when compared with 4.58 (0.44-4.88), 2.21 (0.00-4.81), and 0.00 (0.00-4.81) in the SSG tube and 4.54 (1.54-4.82), 0.90 (0.00-4.49), and 4.85 (4.40-4.99) in the Microcuff tube studies. Leakage in all polyvinylchloride (PVC) tube cuffs was almost complete (5 ml) within 5 min (P<0.001). The tapered PU tube cuff was as effective as the cylindrical PU cuffs in smaller tracheal diameters and was more efficient than the cylindrical Microcuff PU tube cuff in larger tracheal diameter in preventing subglottic fluid leakage across the tube cuff tested in this in vitro study. PVC tube cuffs leaked much more and faster than PU cuffs.

Hair root diameter measurement as an indicator of protein deficiency in nonhospitalized alcoholics.

PubMed

Bregar, R R; Gordon, M; Whitney, E N

1978-02-01

Protein status of alcoholics admitted to a detoxification center was investigated with a view to adapting a hair root test for use in screening for protein deficiency. Hair root volume and hair root diameter had previously been shown to correlate well with hair root protein and to be sensitive indicators of protein deficiency. Hair root volumes in this study correlated well with mean maximum hair root diameters (n = 35, r = 0.9), which were simpler to measure, so diameter measurements were used. Mean maximum hair root diameters (range 0.02 to 0.19 mm) correlated with plasma RNase concentrations (range 6000 to 14,000 units/ml; n = 17, r = -0.7). Mean hair diameters of 84 alcoholics averaged 0.0864 +/- 0.0366 mm; those of 25 nonalcoholics were significantly greater: 0.100 +/- 0.0254 mm (P less than 0.05). Frequency of occurrence of hair root diameters of 0.06 mm or less was significantly higher in 71 alcoholics (29.5%) than in 23 nonalcoholics (8.6%) matched by age. Mean hair root diameters of 0.06 mm or less therefore can be used to signify protein deficiency where more expensive or technically demanding tests are not feasible. Protein deficiency occurs extensively in non hospitalized alcoholics. This method enables staff to single out those clients most likely to be in need of nutritional counseling and therapy.

Setup of Extruded Cementitious Hollow Tubes as Containing/Releasing Devices in Self-Healing Systems

PubMed Central

Formia, Alessandra; Terranova, Salvatore; Antonaci, Paola; Pugno, Nicola Maria; Tulliani, Jean Marc

2015-01-01

The aim of this research is to produce self-healing cementitious composites based on the use of cylindrical capsules containing a repairing agent. Cementitious hollow tubes (CHT) having two different internal diameters (of 2 mm and 7.5 mm) were produced by extrusion and used as containers and releasing devices for cement paste/mortar healing agents. Based on the results of preliminary mechanical tests, sodium silicate was selected as the healing agent. The morphological features of several mix designs used to manufacture the extruded hollow tubes, as well as the coatings applied to increase the durability of both core and shell materials are discussed. Three-point bending tests were performed on samples produced with the addition of the above-mentioned cementitious hollow tubes to verify the self-healing effectiveness of the proposed solution. Promising results were achieved, in particular when tubes with a bigger diameter were used. In this case, a substantial strength and stiffness recovery was observed, even in specimens presenting large cracks (>1 mm). The method is inexpensive and simple to scale up; however, further research is needed in view of a final optimization. PMID:28788038

Planning for Off-Road Recreational Vehicle Use on Army Installations

DTIC Science & Technology

1982-07-01

should include species composition, size of woody vegetation, and number of dead stems greater than 20 mm in diameter. (4) Record the general condition...Determine the following from test sections: (1) Impact on young vegetative growth. (2) Impact on larger trees and shrubs (compaction, direct damage...Association of Midwest Fish and Wildlife Com- missioners (1973), pp 37-49. International Snowuobiling Industry Association (ISIA), The Role of

The use of small (2.7 mm) screws for arthroscopically guided repair of carpal chip fractures.

PubMed

Wright, I M; Smith, M R W

2011-05-01

Removal of large chip fractures of the carpal bones and the osteochondral deficits that result, have been associated with a worse prognosis than removal of small fragments in similar locations. Reducing the articular defects by repair of large osteochondral fragments may have advantages over removal. Horses with osteochondral chip fractures that were of sufficient size and infrastructure to be repaired with small (2.7 mm diameter) AO/ASIF cortex screws were identified and repair effected by arthroscopically guided internal fixation. Thirty-three horses underwent surgery to repair 35 fractures of the dorsodistal radial carpal bone (n = 25), the dorsal margin of the radial facet of the third carpal bone (n = 9) and the intermediate facet of the distal radius (n = 1). There were no surgical complications and fractures healed satisfactorily in 26 of 28 horses and 23 horses returned to racing performance. Arthroscopically guided repair of carpal chip fractures with small diameter cortex screws is technically feasible and experiences with 33 cases suggest that this may have advantages over fragment removal in managing such cases. Surgeons treating horses with large chip fractures of the carpal bones should consider arthroscopically guided internal fixation as an alternative to removal. © 2010 EVJ Ltd.

Temporary Rectal Stenting for Management of Severe Perineal Wounds in Two Dogs.

PubMed

Skinner, Owen T; Cuddy, Laura C; Coisman, James G; Covey, Jennifer L; Ellison, Gary W

Perineal wounds in dogs present a challenge due to limited local availability of skin for closure and constant exposure to fecal contaminants. This report describes temporary rectal stenting in two dogs following severe perineal wounds. Dog 1 presented with a 4 × 4 cm full-thickness perineal slough secondary to multiple rectal perforations. A 12 mm internal diameter endotracheal tube was placed per-rectum as a temporary stent to minimize fecal contamination. The stent was removed 18 days after placement, and the perineal wound had healed at 32 days post-stent placement, when a minor rectal stricture associated with mild, intermittent tenesmus was detected. Long-term outcome was deemed good. Dog 2 presented with multiple necrotic wounds with myiasis, circumferentially surrounding the anus and extending along the tail. A 14 mm internal diameter endotracheal tube was placed per-rectum. The perineal and tail wounds were managed with surgical debridement and wet-to-dry and honey dressings prior to caudectomy and negative pressure wound therapy (NPWT). Delayed secondary wound closure and stent removal were performed on day six without complication. Long-term outcome was deemed excellent. Temporary rectal stenting may be a useful technique for fecal diversion to facilitate resolution of complex perineal injuries, including rectal perforation.

Facilitated giga-seal formation with a just originated glass surface.

PubMed

Böhle, T; Benndorf, K

1994-07-01

A simple technique of tip preparation in patch pipettes is described, which facilitates giga-seal formation. The pipettes were fabricated from thick-walled borosilicate glass tubing (external diameter 2.0 mm, internal diameter 0.5 mm) and the tips could be repeatedly broken in the bath. The pipette resistance correspondingly fell in steps of 3-20 M omega from about 80 M omega to about 2 M omega (double concentrated Tyrode). Scanning electron microscopy showed that the tip obtained after breaking was fairly plain. These broken tips were especially appropriate for patch-clamping. In cardiac myocytes in 11 out of 26 patches with Na+ channel activity, giga-seals developed spontaneously, i.e. without suction. In these patches the amplitude of the mean current with depolarizing pulses to -40 mV was significantly higher in comparison with patches formed under negative pressure. It is concluded that spontaneously sealed patches are most likely of planar configuration and the Na+ channel activity exceeds that in suction-induced patches.

Relationship of vocal cord paralysis to the coil diameter of vagus nerve stimulator leads.

PubMed

Robinson, Leslie C; Winston, Ken R

2015-03-01

This investigation was done to examine, following implantation of vagus nerve stimulators, the relationship of vocal cord paralysis to the inner diameter of the coils used to attach the stimulator lead to the nerve. All data in this investigation were collected, as mandated by the FDA, by the manufacturer of vagus nerve stimulators and were made available without restrictions for analysis by the authors. The data reflect all initial device implantations in the United States for the period from 1997 through 2012. Vocal cord paralysis was reported in 193 of 51,882 implantations. In patients aged 18 years and older, the incidence of paralysis was 0.26% when the stimulator leads had coil diameters of 3 mm and 0.51% when the leads had 2-mm-diameter coils (p < 0.05). Across all age groups, the incidence of vocal cord paralysis increased with age at implantation for leads having 2-mm-diameter coils. In patients aged 18 years and older, vocal cord paralysis occurred at almost twice the rate with the implantation of vagus nerve stimulator leads having 2-mm-diameter coils than with leads having 3-mm-diameter coils. The incidence of vocal cord paralysis increases with patient age at implantation.

Design of an Ultra-wide Band Waveguide Transition for the Ex-vessel Transmission Line of ITER Plasma Position Reflectometry

NASA Astrophysics Data System (ADS)

Simonetto, A.; Platania, P.; Garavaglia, S.; Gittini, G.; Granucci, G.; Pallotta, F.

2018-02-01

Plasma position reflectometry for ITER requires interfaces between in-vessel and ex-vessel waveguides. An ultra broadband interface (15-75 GHz) was designed between moderately oversized rectangular waveguide (20 × 12 mm), operated in TE01 (i.e., tall waveguide mode), and circular corrugated waveguide, with 88.9-mm internal diameter, propagating HE11. The interface was designed both as a sequence of waveguide components and as a quasi-optical confocal telescope. The design and the simulated performance are described for both concepts. The latter one requires more space but has better performance, and shall be prototyped.

Prevalence and morphometric analysis of three-rooted mandibular first molars in a Brazilian subpopulation

PubMed Central

Rodrigues, Clarissa Teles; de Oliveira-Santos, Christiano; Bernardineli, Norberti; Duarte, Marco Antonio Hungaro; Bramante, Clovis Monteiro; Minotti-Bonfante, Paloma Gagliardi; Ordinola-Zapata, Ronald

2016-01-01

ABSTRACT The knowledge of the internal anatomy of three-rooted mandibular molars may help clinicians to diagnose and plan the root canal treatment in order to provide adequate therapy when this variation is present. Objectives: To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT. Material and Methods: CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05). Results: The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals. Conclusions: Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter. PMID:27812625

Comparison of the size of persistent foramen ovale and atrial septal defects in divers with shunt-related decompression illness and in the general population.

PubMed

Wilmshurst, Peter T; Morrison, W Lindsay; Walsh, Kevin P

2015-06-01

Decompression illness (DCI) is associated with a right-to-left shunt, such as persistent foramen ovale (PFO), atrial septal defect (ASD) and pulmonary arteriovenous malformations. About one-quarter of the population have a PFO, but considerably less than one-quarter of divers suffer DCI. Our aim was to determine whether shunt-related DCI occurs mainly or entirely in divers with the largest diameter atrial defects. Case control comparison of diameters of atrial defects (PFO and ASD) in 200 consecutive divers who had transcatheter closure of an atrial defect following shunt-related DCI and in an historic group of 263 individuals in whom PFO diameter was measured at post-mortem examination. In the divers who had experienced DCI, the median atrial defect diameter was 10 mm and the mean (standard deviation) was 9.9 (3.6) mm. Among those in the general population who had a PFO, the median diameter was 5 mm and mean was 4.9 (2.6) mm. The difference between the two groups was highly significant (P < 0.0001). Of divers with shunt-related DCI, 101 (50.5%) had an atrial defect 10 mm diameter or larger, but only 1.3% of the general population studied had a PFO that was 10 mm diameter of larger. The risk of a diver suffering DCI is related to the size of the atrial defect rather than just the presence of a defect.

Quantitative angiographic anatomy of the renal arteries and adjacent aorta in the swine for preclinical studies of intravascular catheterization devices.

PubMed

Sakaoka, Atsushi; Koshimizu, Masafumi; Nakamura, Shintaro; Matsumura, Kiyoshi

2018-05-10

Swine are the most common animal model in preclinical studies of cardiovascular devices. Because of the recent trend for development of new devices for percutaneous catheterization, especially for the renal arteries (RAs), we examined the quantitative anatomical dimensions of the RAs and adjacent aorta in swine. Angiographic images were analyzed in 66 female Yorkshire/Landrace crossbred swine. The diameter of both the right and left main RA was 5.4 ± 0.6 mm. The length of the right main RA was significantly longer than that of the left (29.8 ± 7.5 mm vs. 20.6 ± 5.4 mm, respectively; P<0.001). The diameter of both the right and left branch RA with diameters ≥3 mm (the target vessel diameter of recently developed devices) was 3.8 ± 0.5 mm. The right branch RA was significantly longer than that of the left (18.9 ± 7.8 mm vs. 16.4 ± 7.4 mm, respectively; P<0.05). The branching angle of the right RA from the aorta was significantly smaller than that of the left (91 ± 12° vs. 103 ± 15°, respectively; P<0.001). The diameters of the suprarenal and infrarenal aorta were 10.6 ± 1.1 mm and 9.7 ± 0.9 mm, respectively. In conclusion, because of their similar dimensions to human, swine are an appropriate animal model for assessing the safety of, and determining optimal design of, catheter devices for RAs in simulated clinical use. However, there were species differences in the branching angle and adjacent aorta diameter, suggesting that swine models alone are inadequate to assess the delivery performance of catheter devices for RAs.

Quantitative angiographic anatomy of the renal arteries and adjacent aorta in the swine for preclinical studies of intravascular catheterization devices

PubMed Central

Sakaoka, Atsushi; Koshimizu, Masafumi; Nakamura, Shintaro; Matsumura, Kiyoshi

2018-01-01

Swine are the most common animal model in preclinical studies of cardiovascular devices. Because of the recent trend for development of new devices for percutaneous catheterization, especially for the renal arteries (RAs), we examined the quantitative anatomical dimensions of the RAs and adjacent aorta in swine. Angiographic images were analyzed in 66 female Yorkshire/Landrace crossbred swine. The diameter of both the right and left main RA was 5.4 ± 0.6 mm. The length of the right main RA was significantly longer than that of the left (29.8 ± 7.5 mm vs. 20.6 ± 5.4 mm, respectively; P<0.001). The diameter of both the right and left branch RA with diameters ≥3 mm (the target vessel diameter of recently developed devices) was 3.8 ± 0.5 mm. The right branch RA was significantly longer than that of the left (18.9 ± 7.8 mm vs. 16.4 ± 7.4 mm, respectively; P<0.05). The branching angle of the right RA from the aorta was significantly smaller than that of the left (91 ± 12° vs. 103 ± 15°, respectively; P<0.001). The diameters of the suprarenal and infrarenal aorta were 10.6 ± 1.1 mm and 9.7 ± 0.9 mm, respectively. In conclusion, because of their similar dimensions to human, swine are an appropriate animal model for assessing the safety of, and determining optimal design of, catheter devices for RAs in simulated clinical use. However, there were species differences in the branching angle and adjacent aorta diameter, suggesting that swine models alone are inadequate to assess the delivery performance of catheter devices for RAs. PMID:29353822

Calculation of laser pulse distribution maps for corneal reshaping with a scanning beam

NASA Astrophysics Data System (ADS)

Manns, Fabrice; Shen, Jin-Hui; Soederberg, Per G.; Matsui, Takaaki; Parel, Jean-Marie A.

1995-05-01

A method for calculating pulse distribution maps for scanning laser corneal surgery is presented. The accuracy, the smoothness of the corneal shape, and the duration of surgery were evaluated for corrections of myopia by using computer simulations. The accuracy and the number of pulses were computed as a function of the beam diameter, the diameter of the treatment zone, and the amount of attempted flattening. The ablation is smooth when the spot overlap is 80% or more. The accuracy does not depend on the beam diameter or on the diameter of the ablation zone when the ablation zone is larger than 5 mm. With an overlap of 80% and an ablation zone larger than 5 mm, the error is 5% of the attempted flattening, and 610 pulses are needed per Diopter of correction with a beam diameter of 1 mm. Pulse maps for the correction of astigmatism were computed and evaluated. The simulations show that with 60% overlap, a beam diameter of 1 mm, and a 5 mm treatment zone, 6 D of astigmatism can be corrected with an accuracy better than 1.8 D. This study shows that smooth and accurate ablations can be produced with a scanning spot.

Human thoracic duct in vitro: diameter-tension properties, spontaneous and evoked contractile activity.

PubMed

Telinius, Niklas; Drewsen, Nanna; Pilegaard, Hans; Kold-Petersen, Henrik; de Leval, Marc; Aalkjaer, Christian; Hjortdal, Vibeke; Boedtkjer, Donna Briggs

2010-09-01

The current study characterizes the mechanical properties of the human thoracic duct and demonstrates a role for adrenoceptors, thromboxane, and endothelin receptors in human lymph vessel function. With ethical permission and informed consent, portions of the thoracic duct (2-5 cm) were resected and retrieved at T(7)-T(9) during esophageal and cardia cancer surgery. Ring segments (2 mm long) were mounted in a myograph for isometric tension (N/m) measurement. The diameter-tension relationship was established using ducts from 10 individuals. Peak active tension of 6.24 +/- 0.75 N/m was observed with a corresponding passive tension of 3.11 +/- 0.67 N/m and average internal diameter of 2.21 mm. The equivalent active and passive transmural pressures by LaPlace's law were 47.3 +/- 4.7 and 20.6 +/- 3.2 mmHg, respectively. Subsequently, pharmacology was performed on rings from 15 ducts that were normalized by stretching them until an equivalent pressure of 21 mmHg was calculable from the wall tension. At low concentrations, norepinephrine, endothelin-1, and the thromboxane-A(2) analog U-46619 evoked phasic contractions (analogous to lymphatic pumping), whereas at higher contractions they induced tonic activity (maximum tension values of 4.46 +/- 0.63, 5.90 +/- 1.4, and 6.78 +/- 1.4 N/m, respectively). Spontaneous activity was observed in 44% of ducts while 51% of all the segments produced phasic contractions after agonist application. Acetylcholine and bradykinin relaxed norepinephrine preconstrictions by approximately 20% and approximately 40%, respectively. These results demonstrate that the human thoracic duct can develop wall tensions that permit contractility to be maintained across a wide range of transmural pressures and that isolated ducts contract in response to important vasoactive agents.

An anatomical study of the intersigmoid fossa and applications for internal hernia surgery.

PubMed

Somé, O R; Ndoye, J M; Yohann, R; Nolan, G; Roccia, H; Dakoure, W P; Chaffanjon, P

2017-03-01

To improve the knowledge of the morphometry and the surrounding anatomical structures of the intersigmoid fossa and to determine possible surgical applications. Forty eight adult cadavers (29 female and 19 male; mean age 83 years) underwent dissection in the Laboratoire d'Anatomie des Alpes Francaises. Two injections in the right carotid resulted in a total body concentration of formalin of 1.3 %. The study parameters were the dimensions of the intersigmoid fossa orifice and the fossa's relationship to surrounding structures. Data were recorded and analyzed using Microsoft Office Excel (MS Cerp). A Pearson coefficient r was used to examine the correlation between the length of colon and the ISF volume. The intersigmoid fossa was present in 75 % of cases (n = 36). The average dimensions for the transverse diameter, longitudinal diameter, and the depth were, respectively, 20.5 ± 0.2, 20.3 ± 0.13, and 26.8 ± 0.2 mm. The primary and secondary roots bordering this fossa measured on average 59.1 ± 0.1 and 48.3 ± 0.13 mm. In 13.9 % of cases (n = 5), the maximum depth was >40 mm and in 16.7 % of cases (n = 6), one of the diameters of the orifice entry of the fossa was >40 mm. The ureter and external iliac artery were the most frequently encountered structures during the dissection of the fundus of the intersigmoid fossa. The intersigmoid fossa remains present in most of the reported dissections of cadavers. It constitutes an essential landmark in the surgery of the sigmoid colon due to its deep structural relationship with the left ureter and external iliac artery.

Reliability of scanning laser acoustic microscopy for detecting internal voids in structural ceramics

NASA Technical Reports Server (NTRS)

Roth, D. J.; Baaklini, G. Y.

1986-01-01

The reliability of 100 MHz scanning laser acoustic microscopy (SLAM) for detecting internal voids in sintered specimens of silicon nitride and silicon carbide was evaluated. The specimens contained artificially implanted voids and were positioned at depths ranging up to 2 mm below the specimen surface. Detection probability of 0.90 at a 0.95 confidence level was determined as a function of material, void diameter, and void depth. The statistical results presented for void detectability indicate some of the strengths and limitations of SLAM as a nondestructive evaluation technique for structural ceramics.

Tracking chamber made of 15-mm mylar drift tubes

NASA Astrophysics Data System (ADS)

Kozhin, A.; Borisov, A.; Bozhko, N.; Fakhrutdinov, R.; Plotnikov, I.

2017-05-01

We are presenting a drift chamber composed from three layers of mylar drift tubes with outer diameter 15 mm. The pipe is made of strip of mylar film 125 micrometers thick covered with aluminium from the both sides. A strip of mylar is wrapped around the mandrel. Pipe is created by ultrasonic welding. A single drift tube is self-supported structure withstanding 350 g wire tension without supports and internal overpressure. About 400 such tubes were assembled. Design, quality control procedures of the drift tubes are described. Seven chambers were glued from these tubes of 560 mm length. Each chamber consists of 3 layers, 16 tubes per layer. Several chambers were tested with cosmic rays. Results of the tests, counting rate plateau and coordinate resolution are presented.

Transhepatic implant of a trimmed Melody™ valved stent in tricuspid position in a 1-year-old infant.

PubMed

Cools, Bjorn; Rega, Filip; Gewillig, Marc

2017-02-15

Percutaneous valved stent implantation is precluded in small infants because large delivery sheaths and large devices. We describe a procedure in a 1-year-old boy in whom a 19 mm Epic™ valve in tricuspid position had become dysfunctional. As the internal diameter of the prosthetic valve was about 16 mm, the only available valve was the Melody™ valved stent. Technical modifications were required to address issues like venous access, the bulky delivery system, and the length of the valved stent. The Melody™ valved stent was surgically trimmed and mounted on a 16 mm Tyshak balloon, access was provided transhepatically through a short 18 Fr sheath. After deployment, the intrahepatic route was sealed with two vascular plugs (8 and 10 mm) in tandem. The procedure was uncomplicated with perfect valve function 18 months after implant. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Gallbladder polyps: factors affecting surgical decision.

PubMed

Sarkut, Pinar; Kilicturgay, Sadik; Ozer, Ali; Ozturk, Ersin; Yilmazlar, Tuncay

2013-07-28

To determine the factors affecting the decision to perform surgery, and the efficiency of ultrasonography (USG) in detecting gallbladder polyps (GP). Data for 138 patients who underwent cholecystectomy between 1996 and 2012 in our clinic with a diagnosis of GP were retrospectively analyzed. Demographic data, clinical presentation, principal symptoms, ultrasonographic and histopathological findings were evaluated. Patients were evaluated in individual groups according to the age of the patients (older or younger than 50 years old) and polyp size (bigger or smaller than 10 mm) and characteristics of the polyps (pseudopolyp or real polyps). χ(2) tests were used for the statistical evaluation of the data. The median age was 50 (26-85) years and 91 of patients were female. Of 138 patients who underwent cholecystectomy with GP diagnosis, only 99 had a histopathologically defined polyp; 77 of them had pseudopolyps and 22 had true polyps. Twenty-one patients had adenocarcinoma. Of these 21 patients, 11 were male, their median age was 61 (40-85) years and all malignant polyps had diameters > 10 mm (P < 0.0001). Of 138 patients in whom surgery were performed, 112 had ultrasonographic polyps with diameters < 10 mm. Of the other 26 patients who also had polyps with diameters > 10 mm, 22 had true polyps. The sensitivity of USG was 84.6% for polyps with diameters > 10 mm (P < 0.0001); however it was only 66% in polyps with diameters < 10 mm. The risk of malignancy was high in the patients over 50 years old who had single polyps with diameters > 10 mm.

[Morphometric anatomic study and clinical significance of lunate fossa].

PubMed

Aldemir, Cengiz; Önder, Merve; Doğan, Ali; Duygun, Fatih; Oğuz, Nurettin

2015-01-01

This study aims to investigate the depth, transverse and sagittal diameters of lunate fossa which is a significant structure of the wrist in terms of reducing the risk for volar plate screws, which are administered in distal radius fractures, from penetrating into the joint. Depth, transverse and sagittal diameters of lunate fossa in 50 right and 50 left adult dried radius bones without distal tip damage were measured by using MicroscribeG2X from the MicroScribe G series. Mean lunate fossa depth: left 2.419886±0.51 mm/right 2.543052±0.78 mm, mean lunate fossa sagittal diameter: left 19.656±1.57 mm/right 18.796±1.53 mm, mean lunate fossa transverse diameter: left 11.382±0.65 mm/right 11.106±0.91 mm. There was no statistically significant difference between right and left depth values of lunate fossa (p=0.320), whereas there was statistically significant difference between right and left transverse and sagittal diameters (p=0.006, p=0.048). Measurements involving depth of lunate fossa may guide the development of new anatomic plates and decrease complications like the penetration of screw into joint whilst volar plate administrations.

Optimizing light delivery for a photoacoustic surgical system

NASA Astrophysics Data System (ADS)

Eddins, Blackberrie; Lediju Bell, Muyinatu A.

2017-03-01

This work explores light delivery optimization for a photoacoustic surgical system previously proposed to provide real-time, intraoperative visualization of the internal carotid arteries hidden by bone during minimally invasive neurosurgeries. Monte Carlo simulations were employed to study 3D light propagation in tissue. For a 2.4 mm diameter drill shaft and 2.9 mm spherical drill tip, the optimal fiber distance from the drill shaft was 2 mm, determined from the maximum normalized fluence seen by the artery. A single fiber was insufficient to deliver light to arteries separated by a minimum of 8 mm. Using similar drill geometry and the optimal 2 mm fiber-to-drill shaft distance, Zemax ray tracing simulations were employed to propagate a 950 nm wavelength Gaussian beam through one or more 600 μm core diameter optical fibers, and the resulting optical beam profile was detected on the representative bone surface. For equally spaced fibers, a single merged optical profile formed with 7 or more fibers, determined by thresholding the resulting light profile images at 1/e times the maximum intensity. The corresponding spot size was larger than that of a single fiber transmitting the same input energy, thus reducing the fluence delivered to the sphenoid bone and enabling higher energies within safety limits. A prototype was designed and built based on these optimization parameters. The methodology we used to optimize our light delivery system to surround surgical tools is generalizable to multiple interventional photoacoustic applications.

Mechanical stability of a novel screw design after repeated insertion: can the double-thread screw serve as a back up?

PubMed

Wiendieck, Kurt; Müller, Helge; Buchfelder, Michael; Sommer, Björn

2018-06-01

We investigated mechanical pull-out behavior and tightening torque of a novel dual-core pedicle "6T screw" (6T). The aim of this study was to test if these changes in screw geometry are increasing the strength of the pedicle screw fixation after repeated insertion. Three different types of pedicle screws were inserted in rigid foam blocks. Tightening torque and pull-out strength were measured during two repetitive insertions of a standard 6.5×45-mm conical screw. The third insertion into the pilot hole was performed using either standard 6.5×45-mm or 7.2×45-mm conical screws or the novel 6.5×45-mm (6T) screw. Additionally, we performed a surface analysis to investigate the bone/screw interface. The maximal tightening torque at the third insertion of the novel 6T screw was 194% higher compared to the standard 6.5×45-mm conical screw and 135% higher compared to the standard 7.2×45-mm conical screw. The pull-out strength of the 6T screw showed no significant changes, and surface analysis revealed a compression of the screw-foam interface due to the different internal diameters. The modified geometrical design of the 6T screw seems to have no statistically significant effect on the pull-out strength, although it achieved a higher tightening torque. This might be due to the different pitch angle cutting a new thread into the material and also to the enlarged inner diameter.

Three-dimensional workstation is useful for measuring the correct size of abdominal aortic aneurysm diameters.

PubMed

Ihara, Tsutomu; Komori, Kimihiro; Yamamoto, Kiyohito; Kobayashi, Masayoshi; Banno, Hiroshi; Kodama, Akio

2013-02-01

Abdominal aortic aneurysm diameter is usually measured by the maximum minor-axis diameter on axial computed tomography (CT). However, this "traditional" diameter may underestimate the real size, as the aorta is not always straight and the aneurysm shape is sometimes in the form of an ellipse along the cross section. Therefore, we measured maximum major-axis diameters using a three-dimensional (3D) workstation and compared them with the traditional maximum minor-axis diameters measured using thin-slice axial CT. CT data of 141 AAA patients (with fusiform aneurysms) were stored in a 3D workstation. These thin-slice CT images were reviewed on the 3D workstation to obtain curved multiplanar reconstruction images (CPR images). Using the CPR images, we measured the maximum major-axis and minor-axis diameters on CPR and the angle of the aneurysms to the body axis. The mean traditional maximum minor-axis diameter was 51.2 ± 8.2 mm, whereas the mean maximum major-axis diameter on CPR was 54.7 ± 10.1 mm. Sixty eight patients had a mean aneurysm size of <50 mm when measured by the traditional minor-axis diameter. Among these patients, five (7.4%) had a major-axis diameter >55 mm on CPR. The measurement of the traditional maximum minor-axis diameter of aneurysms is useful in the case of most patients. However, the traditional maximum minor-axis diameter may underestimate the real aneurysmal diameter, particularly in patients with an ellipse-shaped aneurysm. The maximum major-axis diameter as measured using CPR images is effective for representing the real aneurysmal size. Copyright © 2013 Elsevier Inc. All rights reserved.

Ultrasonographically detected gallbladder polyps: A reason for concern? A seven-year follow-up study

PubMed Central

Kratzer, Wolfgang; Haenle, Mark M; Voegtle, Andrea; Mason, Richard A; Akinli, Atilla S; Hirschbuehl, Klaus; Schuler, Andreas; Kaechele, Volker

2008-01-01

Background The management of coincidental detected gallbladder polyps (GP) is still nebulous. There are few published data regarding their long-term growth. Objective of the present study was to investigate the prevalence and growth of gallbladder polyps in a survey of unselected subjects from the general population of a complete rural community. Methods A total of 2,415 subjects (1,261 women; 1,154 men) underwent ultrasound examination of the gallbladder, in November 1996 as part of a prospective study. Subjects in whom GP were detected at the initial survey underwent follow-up ultrasound examinations after 30 and 84 months. Results At the initial survey gallbladder polyps were detected in 34 subjects (1.4%; females: 1.1%, range 14 to 74 years; males: 1.7%, range 19 to 63 years). Median diameter was 5 ± 2.1 mm (range 2 to10 mm) at the initial survey, 5 mm ± 2.8 mm (range 2 to 12 mm) at 30 months and 4 ± 2.3 mm (range 2 to 9 mm) at 84 months. At the time of first follow-up no change in diameter was found in 81.0% (n = 17), reduction in diameter in 4.8% (n = 1) and increase in diameter in 14.3% (n = 3). At the time of second follow-up no increase in polyp diameter was found in 76.9% (n = 10) and reduction in diameter in 7.7% (n = 1). No evidence of malignant disease of the gallbladder was found. Conclusion Over a period of seven years little change was measured in the diameter of gallbladder polyps. There was no evidence of malignant disease of the gallbladder in any subject. PMID:18793401

Ultrasonographically detected gallbladder polyps: a reason for concern? A seven-year follow-up study.

PubMed

Kratzer, Wolfgang; Haenle, Mark M; Voegtle, Andrea; Mason, Richard A; Akinli, Atilla S; Hirschbuehl, Klaus; Schuler, Andreas; Kaechele, Volker

2008-09-15

The management of coincidental detected gallbladder polyps (GP) is still nebulous. There are few published data regarding their long-term growth. Objective of the present study was to investigate the prevalence and growth of gallbladder polyps in a survey of unselected subjects from the general population of a complete rural community. A total of 2,415 subjects (1,261 women; 1,154 men) underwent ultrasound examination of the gallbladder, in November 1996 as part of a prospective study. Subjects in whom GP were detected at the initial survey underwent follow-up ultrasound examinations after 30 and 84 months. At the initial survey gallbladder polyps were detected in 34 subjects (1.4%; females: 1.1%, range 14 to 74 years; males: 1.7%, range 19 to 63 years). Median diameter was 5 +/- 2.1 mm (range 2 to 10 mm) at the initial survey, 5 mm +/- 2.8 mm (range 2 to 12 mm) at 30 months and 4 +/- 2.3 mm (range 2 to 9 mm) at 84 months. At the time of first follow-up no change in diameter was found in 81.0% (n = 17), reduction in diameter in 4.8% (n = 1) and increase in diameter in 14.3% (n = 3). At the time of second follow-up no increase in polyp diameter was found in 76.9% (n = 10) and reduction in diameter in 7.7% (n = 1). No evidence of malignant disease of the gallbladder was found. Over a period of seven years little change was measured in the diameter of gallbladder polyps. There was no evidence of malignant disease of the gallbladder in any subject.

Measurement of focal ground-glass opacity diameters on CT images: interobserver agreement in regard to identifying increases in the size of ground-glass opacities.

PubMed

Kakinuma, Ryutaro; Ashizawa, Kazuto; Kuriyama, Keiko; Fukushima, Aya; Ishikawa, Hiroyuki; Kamiya, Hisashi; Koizumi, Naoya; Maruyama, Yuichiro; Minami, Kazunori; Nitta, Norihisa; Oda, Seitaro; Oshiro, Yasuji; Kusumoto, Masahiko; Murayama, Sadayuki; Murata, Kiyoshi; Muramatsu, Yukio; Moriyama, Noriyuki

2012-04-01

To evaluate interobserver agreement in regard to measurements of focal ground-glass opacities (GGO) diameters on computed tomography (CT) images to identify increases in the size of GGOs. Approval by the institutional review board and informed consent by the patients were obtained. Ten GGOs (mean size, 10.4 mm; range, 6.5-15 mm), one each in 10 patients (mean age, 65.9 years; range, 58-78 years), were used to make the diameter measurements. Eleven radiologists independently measured the diameters of the GGOs on a total of 40 thin-section CT images (the first [n = 10], the second [n = 10], and the third [n = 10] follow-up CT examinations and remeasurement of the first [n = 10] follow-up CT examinations) without comparing time-lapse CT images. Interobserver agreement was assessed by means of Bland-Altman plots. The smallest range of the 95% limits of interobserver agreement between the members of the 55 pairs of the 11 radiologists in regard to maximal diameter was -1.14 to 1.72 mm, and the largest range was -7.7 to 1.7 mm. The mean value of the lower limit of the 95% limits of agreement was -3.1 ± 1.4 mm, and the mean value of their upper limit was 2.5 ± 1.1 mm. When measurements are made by any two radiologists, an increase in the length of the maximal diameter of more than 1.72 mm would be necessary in order to be able to state that the maximal diameter of a particular GGO had actually increased. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

Operation and commissioning of IFMIF (International Fusion Materials Irradiation Facility) LIPAc injector.

PubMed

Okumura, Y; Gobin, R; Knaster, J; Heidinger, R; Ayala, J-M; Bolzon, B; Cara, P; Chauvin, N; Chel, S; Gex, D; Harrault, F; Ichimiya, R; Ihara, A; Ikeda, Y; Kasugai, A; Kikuchi, T; Kitano, T; Komata, M; Kondo, K; Maebara, S; Marqueta, A; O'Hira, S; Perez, M; Phillips, G; Pruneri, G; Sakamoto, K; Scantamburlo, F; Senée, F; Shinto, K; Sugimoto, M; Takahashi, H; Usami, H; Valette, M

2016-02-01

The objective of linear IFMIF prototype accelerator is to demonstrate 125 mA/CW deuterium ion beam acceleration up to 9 MeV. The injector has been developed in CEA Saclay and already demonstrated 140 mA/100 keV deuterium beam [R. Gobin et al., Rev. Sci. Instrum. 85, 02A918 (2014)]. The injector was disassembled and delivered to the International Fusion Energy Research Center in Rokkasho, Japan. After reassembling the injector, commissioning has started in 2014. Up to now, 100 keV/120 mA/CW hydrogen and 100 keV/90 mA/CW deuterium ion beams have been produced stably from a 10 mm diameter extraction aperture with a low beam emittance of 0.21 π mm mrad (rms, normalized). Neutron production by D-D reaction up to 2.4 × 10(9) n/s has been observed in the deuterium operation.

Preclinical Assessment of a 980-nm Diode Laser Ablation System in a Large Animal Tumor Model

PubMed Central

Ahrar, Kamran; Gowda, Ashok; Javadi, Sanaz; Borne, Agatha; Fox, Matthew; McNichols, Roger; Ahrar, Judy U.; Stephens, Clifton; Stafford, R. Jason

2010-01-01

Purpose To characterize the performance of a 980-nm diode laser ablation system in an in vivo tumor model. Materials and Methods This study was approved by the Institutional Animal Care and Use Committee. The ablation system consisted of a 15-W, 980-nm diode laser, flexible diffusing tipped fiber optic, and 17-gauge internally cooled catheter. Ten immunosuppressed dogs were inoculated subcutaneously with canine transmissible venereal tumor fragments in eight dorsal locations. Laser ablations were performed at 79 sites where inoculations were successful (99%) using powers of 10 W, 12.5 W, and 15 W, with exposure times between 60 and 180 seconds. In 20 cases, multiple overlapping ablations were performed. After the dogs were euthanized, the tumors were harvested, sectioned along the applicator track, measured and photographed. Measurements of ablation zone were performed on gross specimen. Histopathology and viability staining was performed using hematoxylin and eosin (H&E) and nicotinamide adenine dinucleotide hydrogen (NADH) staining. Results Gross pathology confirmed well-circumscribed ablation zone with sharp boundaries between thermally ablated tumor in the center surrounded by viable tumor tissue. When a single applicator was used, the greatest ablation diameters ranged from 12 mm at the lowest dose (10 W, 60 sec) to 26 mm at the highest dose (15 W, 180 sec). Multiple applicators created ablation zones of up to 42 mm in greatest diameter (with the lasers operating at 15 W for 120 sec). Conclusions The new 980-nm diode laser and internally cooled applicator effectively creates large ellipsoid thermal ablations in less than 3 minutes. PMID:20346883

Purpura

MedlinePlus

Blood spots; Skin hemorrhages ... and 10 mm (millimeters) in diameter. When purpura spots are less than 4 mm in diameter, they are called petechiae . Purpura spots larger than 1 cm (centimeter) are called ecchymoses. ...

Numerical analysis of specific absorption rate in the human head due to a 13.56 MHz RFID-based intra-ocular pressure measurement system.

PubMed

Hirtl, Rene; Schmid, Gernot

2013-09-21

A modern wireless intra-ocular pressure monitoring system, based on 13.56 MHz inductively coupled data transmission, was dosimetrically analyzed with respect to the specific absorption rate (SAR) induced inside the head and the eye due to the electromagnetic field exposure caused by the reader antenna of the transmission system. The analysis was based on numerical finite difference time domain computations using a high resolution anatomical eye model integrated in a modern commercially available anatomical model of a male head. Three different reader antenna configurations, a 7-turn elliptic (30 mm × 50 mm) antenna at 12 mm distance from the eye, a flexible circular antenna (60 mm diameter, 8 turns on 2 mm substrate) directly attached to the skin, and a circular 7-turn antenna (30 mm diameter at 12 mm distance to the eye) were analyzed, respectively. Possible influences of the eye-lid status (closed or opened) and the transponder antenna contained in a contact lens directly attached to the eye were taken into account. The results clearly demonstrated that for typical reader antenna currents required for proper data transmission, the SAR values remain far below the limits for localized exposure of the head, as defined by the International Commission for Non-Ionizing Radiation Protection. Particularly the induced SAR inside the eye was found to be substantially (orders of magnitudes for typical reader antenna currents in the order of 1 A turn) below values which have been reported to be critical with respect to thermally induced adverse health effects in eye tissues.

Comparison of postoperative vault height predictability using white-to-white or sulcus diameter-based sizing for the visian implantable collamer lens.

PubMed

Reinstein, Dan Z; Lovisolo, Carlo F; Archer, Timothy J; Gobbe, Marine

2013-01-01

To compare vault height predictability of Implantable Collamer Lens (ICL; Staar Surgical) sizing using a sulcus diameter-based formula or the manufacturer-recommended white-to-white-based method. In 50 myopic eyes, ICL size was calculated using both a formula including sulcus diameter and the traditional formula based on white-to-white diameter. Sulcus diameter was measured using Artemis 2 very high-frequency (VHF) digital ultrasound (ArcScan Inc). Implantation was based on the sulcus diameter derived size. Actual postoperative vault height achieved was measured by VHF digital ultrasound scanning. Circle segment trigonometry was used to calculate the vault height that would have resulted had lens sizing been based on the white-to-white formula. The same lens size would have been used in 60% of eyes, a smaller lens would have been used in 34% of eyes and a larger lens in 6% of eyes had lens sizing been based on the white-to-white formula. Mean vault for eyes with lenses sized using the sulcus diameter formula was 0.37±0.16 mm (range: 0.08 to 0.92 mm), with 2% <0.09 mm, the recognized low-vault height for risk of cataract. Circle segment trigonometry predicted that the vault height would have been 0.24±0.28 mm (range: -0.31 to 0.92 mm), with 26% <0.09 mm had lens sizing been based on the white-to-white formula. Significantly better predictability of postoperative vault height was achieved by including sulcus diameter into the ICL sizing formula compared with using the traditional white-to-white-based formula. Copyright 2013, SLACK Incorporated.

Fatigue performance of joints executed in pure titanium structures with several diameters.

PubMed

Nuñez-Pantoja, Juliana Maria Costa; Vaz, Luis Geraldo; Nóbilo, Mauro Antônio de Arruda; Mesquita, Marcelo Ferraz

2011-01-01

This study evaluated fatigue strength of CP-Ti laser-welded joints. Sixty (20/diameter) CP-Ti casted dumbbell rods with diameters of 1.5, 2.0, and 3.5 mm were sectioned and welded using two joint openings (0.0 (00) and 0.6 mm (06)). Six groups were formed, amounting to a total of 9 (n=10) with inclusion of intact groups. Welding was executed using 360 V/8 ms (1.5 and 2.0 mm) and 380 V/9 ms (3.5 mm). Joints were finished, polished, and submitted to radiographic examination to visually analyze presence of porosity (PP). Specimens were submitted to cyclic tests, and the number of cycles until failure (NC) was recorded. Fractured surfaces were examined by SEM. Kruskal-Wallis and Dunn (α=0.05) tests demonstrated that NC was lower for all diameters with 06, and for 3.5 mm/00. NC and PP were found to have a negative correlation (Spearman Coefficient). For CP-Ti frameworks with thin diameters, laser welding is better when structures are juxtaposed.

Ascending aortic elongation and the risk of dissection.

PubMed

Krüger, Tobias; Forkavets, Oksana; Veseli, Kujtim; Lausberg, Henning; Vöhringer, Luise; Schneider, Wilke; Bamberg, Fabian; Schlensak, Christian

2016-08-01

Unlike aneurysm formation, the role of ascending aortic elongation in the pathogenesis of Type A aortic dissection (TAD) is largely unclear. We investigated the morphology of healthy, dissected and predissection aortas with a focus on ascending aortic length. We retrospectively compared clinical and computer tomography angiography (CTA) data from TAD patients (n = 130), patients who developed a TAD in the further clinical course (preTAD, n = 16) and healthy control patients who received a CTA for non-aortic emergencies (n = 165). The length of the ascending aorta was defined as the distance between the sinotubular junction (STJ) and the brachiocephalic trunk (BCT) at the central line, the outer and inner curvature as well as the direct distance in the frontal and sagittal planes. Additionally, the aortic diameters were analysed. In the healthy controls, we found a positive correlation of age with the aortic diameter (r = 0.57) and aortic length (r = 0.42). The correlation of the respective parameters with the body size was negligible (r < 0.2). The median ascending aortic diameter at the height of the pulmonary artery in TAD (50 mm) was significantly (P < 0.001) larger compared with the respective diameter of the healthy aortas (34 mm). The diameter of the preTAD aortas (40 mm) was also significantly larger compared with the healthy controls. These proportions were similar in all the aortic diameters. The midline length of the healthy ascending aortas was 71 mm. In the preTAD and TAD aortas, the same values were 81 mm and 92 mm, respectively (both P < 0.001). We evaluated the linear distance between the STJ and the BCT in the frontal plane as an easy-to-measure parameter of aortic length. In the TAD aortas (108 mm) and preTAD aortas (97 mm), this distance was significantly longer compared with the healthy aortas (84 mm). Aortic diameter might not be an optimal parameter to predict dissection. Most aortas dissect at diameters below 55 mm. Both the TAD and preTAD aortas were elongated compared with the healthy controls. Thus, aortic elongation may play a role in the pathogenesis of and may be a risk factor for TAD. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

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

Menikoff, Ralph

Previously the SURFplus reactive burn model was calibrated for the TATB based explosive PBX 9502. The calibration was based on fitting Pop plot data, the failure diameter and the limiting detonation speed, and curvature effect data for small curvature. The model failure diameter is determined utilizing 2-D simulations of an unconfined rate stick to find the minimum diameter for which a detonation wave propagates. Here we examine the effect of mesh resolution on an unconfined rate stick with a diameter (10mm) slightly greater than the measured failure diameter (8 to 9 mm).

Dissection and Exposure of the Whole Course of Deep Nerves in Human Head Specimens after Decalcification

PubMed Central

Liu, Longping; Arnold, Robin; Robinson, Marcus

2012-01-01

The whole course of the chorda tympani nerve, nerve of pterygoid canal, and facial nerves and their relationships with surrounding structures are complex. After reviewing the literature, it was found that details of the whole course of these deep nerves are rarely reported and specimens displaying these nerves are rarely seen in the dissecting room, anatomical museum, or atlases. Dissections were performed on 16 decalcified human head specimens, exposing the chorda tympani and the nerve connection between the geniculate and pterygopalatine ganglia. Measurements of nerve lengths, branching distances, and ganglia size were taken. The chorda tympani is a very fine nerve (0.44 mm in diameter within the tympanic cavity) and approximately 54 mm in length. The mean length of the facial nerve from opening of internal acoustic meatus to stylomastoid foramen was 52.5 mm. The mean length of the greater petrosal nerve was 26.1 mm and nerve of the pterygoid canal was 15.1 mm. PMID:22523494

Smaller-diameter circular stapler has an advantage in Billroth I stapled anastomosis after laparoscopy-assisted distal gastrectomy.

PubMed

Kim, Min-Kyoon; Park, Joong-Min; Choi, Yoo-Shin; Chi, Kyong-Choun

2012-04-01

Billroth I gastroduodenostomy using a circular stapler is the most preferred reconstruction method after laparoscopy-assisted distal gastrectomy (LADG). The optimal stapler size for this procedure has not yet been proposed. Sixty-five patients who underwent LADG and stapled anastomosis with a 25-mm stapler (25-mm group) and a 29-mm stapler (29-mm group) were enrolled in this study. Clinical data and gastroscopic findings at 6 and 12 months after surgery were retrospectively reviewed. Postoperative complications and postprandial symptoms were similar in both groups. Gastroscopically, food materials remained more frequently in the remnant stomach in the 25-mm group than in the 29-mm group at 6 months after surgery (P=.041). Gastritis and bile reflux were observed more frequently in the 29-mm group than in the 25-mm group (P=.012 and P=.015, respectively). All these differences in the gastroscopic findings between the two groups decreased at 12 months after surgery except for reflux esophagitis, which was observed more frequently in the 29-mm group (P=.002). The length of the incision was smaller in the 25-mm group than in the 29-mm group (4.39 cm versus 4.95 cm, P=.009). A small-diameter stapler is a risk factor for gastric stasis in the early postoperative period, whereas a large-diameter stapler is a risk factor for gastritis and bile reflux in the early postoperative period and for esophagitis in the late postoperative period. Thus, a small-diameter circular stapler has more advantages over a large-diameter circular stapler. It also enables a reliable anastomosis through a smaller incision and easy handling of the stapler during anastomosis.

Design of a simple cryogenic system for ultraviolet-visible absorption spectroscopy with a back-reflectance fiber optic probe.

PubMed

Vinyard, Andrew; Hansen, Kaj A; Byrd, Ross; Stuart, Douglas A; Hansen, John E

2014-01-01

We report a convenient and inexpensive technique for the rapid acquisition of absorption spectra from small samples at cryogenic temperatures using a home built cryostat with novel collection optics. A cylindrical copper block was constructed with a coaxial bore to hold a 4.00 mm diameter electron paramagnetic resonance (EPR) tube and mounted on a copper feed in thermal contact with liquid nitrogen. A 6.35 mm diameter hole was bored into the side of the cylinder so a fiber optic cable bundle could be positioned orthogonally to the EPR tube. The light passing through the sample is reflected off of the opposing surfaces of the EPR tube and surrounding copper, back through the sample. The emergent light is then collected using the fiber optic bundle and analyzed using a dispersive spectrometer. Absorption spectra for KMnO4 were measured between 400 and 700 nm. Absorption intensity at 506, 525, 545, and 567 nm was found to be proportional to concentration, displaying Beer's law-like behavior. The EPR tube had an internal diameter of 3.2 mm; the double pass of the probe beam through the sample affords a central path length of about 6.4 mm. Comparing these measurements with those recorded on a conventional tabletop spectrometer using a cuvette with a 10.00 mm path length, we consistently found a ratio between intensities of 0.58 rather than the anticipated 0.64. These 6% smaller values we attribute to the curvature of the EPR tube and transmission/reflection losses. This system is particularly well-suited to studying the kinetics and dynamics of chemical reactions at cryogenic temperatures. The rapid response (100 ms) and multiplex advantage provided the opportunity of recording simultaneous time courses at several wavelengths following initiation of a chemical reaction with a pulsed laser source.

Heat generated during seating of dental implant fixtures.

PubMed

Flanagan, Dennis

2014-04-01

Frictional heat can be generated during seating of dental implants into a drill-prepared osteotomy. This in vitro study tested the heat generated by implant seating in dense bovine mandible ramus. A thermocouple was placed approximately 0.5 mm from the rim of the osteotomy during seating of each dental implant. Four diameters of implants were tested. The average temperature increases were 0.075°C for the 5.7-mm-diameter implant, 0.97°C for the 4.7-mm-diameter implant, 1.4°C for the 3.7-mm-diameter implant, and 8.6°C for the 2.5-mm-diameter implant. The results showed that heat was indeed generated and a small temperature rise occurred, apparently by the friction of the implant surface against the fresh-cut bone surface. Bone is a poor thermal conductor. The titanium of the implant and the steel of the handpiece are much better heat conductors. Titanium may be 70 times more heat conductive than bone. The larger diameter and displacement implant may act as a heat sink to draw away any heat produced from the friction of seating the implant at the bone-implant interface. The peak temperature duration was momentary, and not measured, but this was approximately less than 1 second. Except for the 2.5-mm-diameter implants, the temperature rises and durations were found to be below those previously deemed to be detrimental, so no clinically significant osseous damage would be expected during dental implant fixture seating of standard and large-diameter-sized implants. A 2.5-mm implant may generate detrimental heat during seating in nonvital bone, but this may be clinically insignificant in vital bone. The surface area and thermal conductivity are important factors in removing generated heat transfer at the bone-implant interface. The F value as determined by analysis of variance was 69.22, and the P value was less than .0001, demonstrating significant differences between the groups considered as a whole.

Clinical experience in coronary stenting with the Vivant Z Stent.

PubMed

Chee, K H; Siaw, F S; Chan, C G; Chong, W P; Imran, Z A; Haizal, H K; Azman, W; Tan, K H

2005-06-01

This single centre study was designed to demonstrate feasibility, safety and efficacy of the Vivant Z stent (PFM AG, Cologne, Germany). Patients with de novo lesion were recruited. Coronary angioplasty was performed with either direct stenting or after balloon predilatation. Repeated angiogram was performed 6 months later or earlier if clinically indicated. Between January to June 2003, a total of 50 patients were recruited (mean age 55.8 +/- 9 years). A total of 52 lesions were stented successfully. Mean reference diameter was 2.77 mm (+/-0.59 SD, range 2.05-4.39 mm) with mean target lesion stenosis of 65.5% (+/-11.6 SD, range 50.1-93.3%). Forty-six lesions (88.5%) were American College of Cardiologist/American Heart Association class B/C types. Direct stenting was performed in 18 (34.6%) lesions. Mean stent diameter was 3.18 mm (+/-0.41 SD, range 2.5-4 mm), and mean stent length was 14.86 mm (+/-2.72 SD, range 9-18 mm). The procedure was complicated in only one case which involved the loss of side branch with no clinical sequelae. All treated lesions achieved Thrombolysis In Myocardial Infarction 3 flow. Mean residual diameter stenosis was 12.2% (+/-7.55 SD, range 0-22.6%) with acute gain of 1.72 mm (+/-0.50 SD, range 0.5-2.8). At 6 months, there was no major adverse cardiovascular event. Repeated angiography after 6 months showed a restenosis rate of 17% (defined as >50% diameter restenosis). Mean late loss was 0.96 mm (+/-0.48 SD) with loss index of 0.61 (+/-0.38 SD). The restenosis rate of those lesions less than 3.0 mm in diameter was 22.2% compared with 6.25% in those lesions more than 3.0 mm in diameter. The Vivant Z stent was shown to be safe and efficacious with low restenosis rate in de novo coronary artery lesion.

Biliary and pancreatic ductal dilation in patients on methadone maintenance therapy.

PubMed

Bates, David D B; Tamayo-Murillo, Dorathy; Kussman, Steven; Luce, Adam; LeBedis, Christina A; Soto, Jorge A; Anderson, Stephan W

2017-03-01

To determine whether the diameter of intrahepatic and extrahepatic bile ducts and pancreatic ducts in patients on methadone maintenance therapy is increased when compared with control subjects. Between January 1, 2000 and March 15, 2013, a total of 97 patients (mean age 49.9, range 22-79, 65 male, 32 female) were identified who were receiving chronic methadone maintenance therapy (MMT) when they underwent imaging with abdominal MRI or a contrast-enhanced abdominopelvic CT. A group of 97 consecutive non-MMT control patients (mean age 51.4, range 21-86, 45 male, 52 female) who underwent imaging with abdominal MRI or contrast-enhanced abdominopelvic CT were identified. Patients with known pancreaticobiliary pathology that may confound biliary ductal measurements were excluded. Blinded interpretation was performed, documenting the diameters of the intrahepatic and extrahepatic bile ducts and pancreatic ducts. Descriptive statistics were performed. Patients on MMT demonstrated increased bile duct diameter, with an average increase in duct diameter of 2.39 mm for the common bile duct (p < 0.001; 95% CI 1.88-2.90 mm), 1.43 mm for the intrahepatic bile ducts (p < 0.001; 95% CI 1.12-1.74 mm), and 0.90 mm for the pancreatic duct (p < 0.001; 95% CI 0.64-1.16 mm). No statistically significant correlation was found between ductal diameters and the daily dose of methadone. Patients on methadone maintenance therapy demonstrate significantly increased intra- and extrahepatic bile duct and pancreatic duct diameter when compared with controls. There was no correlation between the dose of methadone and ductal diameter.

Reduction of the Areolar Diameter After Ultrasound-Assisted Liposuction for Gynecomastia.

PubMed

Keskin, Mustafa; Sutcu, Mustafa; Hanci, Mustafa; Cigsar, Bulent

2017-08-01

One of the clinical aspects characterizing gynecomastia is the enlargement of the nipple-areolar complex (NAC) due to hypertrophic breast glands, and the excessive fatty tissue underneath. The purpose of this study was to quantify the reduction of the areolar diameter after ultrasound-assisted liposuction (UAL) of the male breast. The horizontal diameters of the NACs of 30 men who underwent UAL were measured before surgery, 1 month after surgery and 6 months after surgery in a standard fashion. Those patients with surgical gland removals of any kind were not included in this study. The mean age of the patients was 27.9 years, and all of the patients had bilateral grade I, II, or III gynecomastia. The mean diameter of the NACs before surgery was 35.36 mm (range, 26-55 mm), and after surgery, the mean diameter of the NACs was initially reduced to 28.8 mm (range, 23-44 mm) and later to 28.57 mm (range, 23-42 mm). The mean volume of breast tissue aspirated was 382 mL per breast, and the percentage of reduction was 17.3%. The reduction of areola diameter was statistically significant after first month. A significant positive correlation was identified between the liposuction volume and areolar diameter reduction. In cases of gynecomastia, the removal of the glandular and fatty tissue underneath the areola releases the expanding forces and pressure that enlarge it. In many cases of gynecomastia, UAL alone is effective in reducing the size of the NAC and allows the surgeon to avoid placing scars on the breast.

Fine root morphological traits determine variation in root respiration of Quercus serrata.

PubMed

Makita, Naoki; Hirano, Yasuhiro; Dannoura, Masako; Kominami, Yuji; Mizoguchi, Takeo; Ishii, Hiroaki; Kanazawa, Yoichi

2009-04-01

Fine root respiration is a significant component of carbon cycling in forest ecosystems. Although fine roots differ functionally from coarse roots, these root types have been distinguished based on arbitrary diameter cut-offs (e.g., 2 or 5 mm). Fine root morphology is directly related to physiological function, but few attempts have been made to understand the relationships between morphology and respiration of fine roots. To examine relationships between respiration rates and morphological traits of fine roots (0.15-1.4 mm in diameter) of mature Quercus serrata Murr., we measured respiration of small fine root segments in the field with a portable closed static chamber system. We found a significant power relationship between mean root diameter and respiration rate. Respiration rates of roots<0.4 mm in mean diameter were high and variable, ranging from 3.8 to 11.3 nmol CO2 g(-1) s(-1), compared with those of larger diameter roots (0.4-1.4 mm), which ranged from 1.8 to 3.0 nmol CO2 g(-1) s(-1). Fine root respiration rate was positively correlated with specific root length (SRL) as well as with root nitrogen (N) concentration. For roots<0.4 mm in diameter, SRL had a wider range (11.3-80.4 m g(-1)) and was more strongly correlated with respiration rate than diameter. Our results indicate that a more detailed classification of fine roots<2.0 mm is needed to represent the heterogeneity of root respiration and to evaluate root biomass and root morphological traits.

[Accuracy of Modulation Transfer Function for Target Size and Field of View in a Circular Edge Strategy Using the CT Image Measurement Program].

PubMed

Fukunaga, Masaaki; Onishi, Hideo; Matsutomo, Norikazu; Yamamoto, Hiroyuki

2016-06-01

The purpose of this study was to evaluate the effects of target diameter and display-field of view (D-FOV) in modulation transfer function (MTF) by circular edge strategy using the computed tomography (CT) image measurement program "CTmeasure". We calculated the MTF (MTF(edge)) using the circular edge strategy applied to cylindrical phantom (200 mmφ) that inserted with cylinders have 10, 20, 30, and 40 mm diameters. The phantom images were reconstructed using filtered back projection method varied with D-FOV (240, 320, 400, and 500 mm). The study compared both MTF(edge) and MTF(wire) at MTF50% and MTF(10%) for target diameter and D-FOV, respectively. The MTF(edge) by the different of target diameter indicated in rough compatibility. However, MTF(edge) of D-FOV diameters (320, 400, and 500 mm) decreased in the high frequency range. The circular edge strategy for MTF depended on the D-FOV, however, it was little dependent on target diameter using the CT image measurement program "CTmeasure".

Gallbladder polyps: Factors affecting surgical decision

PubMed Central

Sarkut, Pinar; Kilicturgay, Sadik; Ozer, Ali; Ozturk, Ersin; Yilmazlar, Tuncay

2013-01-01

AIM: To determine the factors affecting the decision to perform surgery, and the efficiency of ultrasonography (USG) in detecting gallbladder polyps (GP). METHODS: Data for 138 patients who underwent cholecystectomy between 1996 and 2012 in our clinic with a diagnosis of GP were retrospectively analyzed. Demographic data, clinical presentation, principal symptoms, ultrasonographic and histopathological findings were evaluated. Patients were evaluated in individual groups according to the age of the patients (older or younger than 50 years old) and polyp size (bigger or smaller than 10 mm) and characteristics of the polyps (pseudopolyp or real polyps). χ2 tests were used for the statistical evaluation of the data. RESULTS: The median age was 50 (26-85) years and 91 of patients were female. Of 138 patients who underwent cholecystectomy with GP diagnosis, only 99 had a histopathologically defined polyp; 77 of them had pseudopolyps and 22 had true polyps. Twenty-one patients had adenocarcinoma. Of these 21 patients, 11 were male, their median age was 61 (40-85) years and all malignant polyps had diameters > 10 mm (P < 0.0001). Of 138 patients in whom surgery were performed, 112 had ultrasonographic polyps with diameters < 10 mm. Of the other 26 patients who also had polyps with diameters > 10 mm, 22 had true polyps. The sensitivity of USG was 84.6% for polyps with diameters > 10 mm (P < 0.0001); however it was only 66% in polyps with diameters < 10 mm. CONCLUSION: The risk of malignancy was high in the patients over 50 years old who had single polyps with diameters > 10 mm. PMID:23901228

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

Mankovich, N.J.; Lambert, T.; Zrimec, T.

A project is underway to develop automated methods of fusing cerebral magnetic resonance angiography (MRA) and x-ray angiography (XRA) for creating accurate visualizations used in planning treatment of vascular disease. The authors have developed a vascular phantom suitable for testing segmentation and fusion algorithms with either derived images (pseudo-MRA/pseudo-XRA) or actual MRA or XRA image sequences. The initial unilateral arterial phantom design, based on normal human anatomy, contains 48 tapering vascular segments with lumen diameters from 2.5 millimeter to 0.25 millimeter. The initial phantom used rapid prototyping technology (stereolithography) with a 0.9 millimeter vessel wall fabricated in an ultraviolet-cured plastic.more » The model fabrication resulted in a hollow vessel model comprising the internal carotid artery, the ophthalmic artery, and the proximal segments of the anterior, middle, and posterior cerebral arteries. The complete model was fabricated but the model`s lumen could not be cleared for vessels with less than 1 millimeter diameter. Measurements of selected vascular outer diameters as judged against the CAD specification showed an accuracy of 0.14 mm and precision (standard deviation) of 0.15 mm. The plastic vascular model produced provides a fixed geometric framework for the evaluation of imaging protocols and the development of algorithms for both segmentation and fusion.« less

Anatomic vascular phantom for the verification of MRA and XRA visualization and fusion

NASA Astrophysics Data System (ADS)

Mankovich, Nicholas J.; Lambert, Timothy; Zrimec, Tatjana; Hiller, John B.

1995-05-01

A project is underway to develop automated methods of fusing cerebral magnetic resonance angiography (MRA) and x-ray angiography (XRA) for creating accurate visualizations used in planning treatment of vascular disease. We have developed a vascular phantom suitable for testing segmentation and fusion algorithms with either derived images (psuedo-MRA/psuedo-XRA) or actual MRA or XRA image sequences. The initial unilateral arterial phantom design, based on normal human anatomy, contains 48 tapering vascular segments with lumen diameters from 2.5 millimeter to 0.25 millimeter. The initial phantom used rapid prototyping technology (stereolithography) with a 0.9 millimeter vessel wall fabricated in an ultraviolet-cured plastic. The model fabrication resulted in a hollow vessel model comprising the internal carotid artery, the ophthalmic artery, and the proximal segments of the anterior, middle, and posterior cerebral arteries. The complete model was fabricated but the model's lumen could not be cleared for vessels with less than 1 millimeter diameter. Measurements of selected vascular outer diameters as judged against the CAD specification showed an accuracy of 0.14 mm and precision (standard deviation) of 0.15 mm. The plastic vascular model produced provides a fixed geometric framework for the evaluation of imaging protocols and the development of algorithms for both segmentation and fusion.

Use of a specially designed partially covered self-expandable metal stent (PSEMS) with a 40-mm diameter for the treatment of upper gastrointestinal suture or staple line leaks in 11 cases.

PubMed

Fischer, Andreas; Bausch, Dirk; Richter-Schrag, Hans-Juergen

2013-02-01

The use of self-expandable stents to treat postoperative leaks and fistula in the upper gastrointestinal (GI) tract is an established treatment for leaks of the upper GI tract. However, lumen-to-stent size discrepancies (i.e., after sleeve gastrectomy or esophageal resection) may lead to insufficient sealing of the leaks requiring further surgical intervention. This is mainly due to the relatively small diameter (≤30 mm) of commonly used commercial stents. To overcome this problem, we developed a novel partially covered stent with a shaft diameter of 36 mm and a flare diameter of 40 mm. From September 2008 to September 2010, 11 consecutive patients with postoperative leaks were treated with the novel large diameter stent (gastrectomy, n = 5; sleeve gastrectomy, n = 2; fundoplication after esophageal perforation, n = 2; Roux-en-Y gastric bypass, n = 1; esophageal resection, n = 1). Treatment with commercially available stents (shaft/flare: 23/28 mm and 24/30 mm) had been unsuccessful in three patients before treatment with the large diameter stent. Due to dislocation, the large diameter stent was anchored in four patients (2× intraoperatively with transmural sutures, 2× endoscopically with transnasally externalized threads). Treatment was successful in 11 of 11 patients. Stent placement and removal was easy and safe. The median residence time of the stent was 24 (range, 18-41) days. Stent dislocation occurred in four cases (36 %). It was treated by anchoring the stent. Mean follow-up was 25 (range, 14-40) months. No severe complication occurred during or after intervention and no patient was dysphagic. Using the novel large diameter, partially covered stent to seal leaks in the upper GI tract is safe and effective. The large diameter of the stent does not seem to injure the wall of the upper GI tract. However, stent dislocation sometimes requires anchoring of the stent with sutures or transnasally externalized threads.

[Determination of a Friction Coefficient for THA Bearing Couples].

PubMed

Vrbka, M; Nečas, D; Bartošík, J; Hartl, M; Křupka, I; Galandáková, A; Gallo, J

2015-01-01

The wear of articular surfaces is considered one of the most important factors limiting the life of total hip arthroplasty (THA). It is assumed that the particles released from the surface of a softer material induce a complex inflammatory response, which will eventually result in osteolysis and aseptic loosening. Implant wear is related to a friction coefficient which depends on combination of the materials used, roughness of the articulating surfaces, internal clearance, and dimensions of the prosthesis. The selected parameters of the bearing couples tested were studied using an experimental device based on the principle of a pendulum. Bovine serum was used as a lubricant and the load corresponded to a human body mass of 75 kg. The friction coefficient was derived from a curve of slowdown of pendulum oscillations. Roughness was measured with a device working on the principle of interferometry. Clearance was assessed by measuring diameters of the acetabular and femoral heads with a 3D optical scanner. The specimens tested included unused metal-on-highly cross-linked polyethylene, ceramic-on-highly cross-linked polyethylene and ceramic-on-ceramic bearing couples with the diameters of 28 mm and 36 mm. For each measured parameter, an arithmetic mean was calculated from 10 measurements. 1) The roughness of polyethylene surfaces was higher by about one order of magnitude than the roughness of metal and ceramic components. The Protasul metal head had the least rough surface (0.003 μm). 2) The ceramic-on-ceramic couples had the lowest clearance. Bearing couples with polyethylene acetabular liners had markedly higher clearances ranging from 150 μm to 545 μm. A clearance increased with large femoral heads (up to 4-fold in one of the couple tested). 3) The friction coefficient was related to the combination of materials; it was lowest in ceramic-on-ceramic surfaces (0.11 to 0.12) and then in ceramic-on-polyethylene implants (0.13 to 0.14). The friction coefficient is supposed to increase with a decreasing femoral head diameter. However, in the bearing couples with polyethylene liners manufactured by one company, paradoxically, the friction coefficient slightly increased with an increase in femoral head size from 28 mm to 36 mm. 4) The lowest friction moment (< 3.5 Nm) was found for ceramic-on-ceramic implants 28 mm in diameter; the highest values were recorded in metal-on-polyethylene bearing couples 36 mm in diameter (> 7 Nm). Although our study confirmed that the bearing couples produced by different manufacturers varied to some extent in the parameters studied, in our opinion, this variability was not significant because it was not within an order of magnitude in any of the tests. The study showed that both the friction coefficient and the friction moment are affected more by the combination of materials than by the diameter of a femoral head. The best results were achieved in ceramic-on-ceramic implants.

Using polycrystalline diamond-veined drills on silicon carbide particulate-reinforced aluminium castings

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

Lane, C.

1993-12-31

Using several combinations of speeds and feeds, a series of 6.37-mm diameter holes were drilled through a 19-mm thick plate of DURALCAN F3S.20S-T6 (A359/SiC/20p-T6). Every 50th hole was drilled in a gage block to measure the following: torque, thrust, drill flank wear, hole diameter, hole roundness, and hole surface finish. Maximum tool life was attained using feed rates of 0.25 mm/revolution. Speed had little effect on tool forces or life. Under optimum conditions, PCD-veined drills can produce over 6000 diameters of through holes in this type of composite with tolerances of 0.01 mm and flank wear of only 0.1 mm.

A High-Performance Portable Transient Electro-Magnetic Sensor for Unexploded Ordnance Detection.

PubMed

Wang, Haofeng; Chen, Shudong; Zhang, Shuang; Yuan, Zhiwen; Zhang, Haiyang; Fang, Dong; Zhu, Jun

2017-11-17

Portable transient electromagnetic (TEM) systems can be well adapted to various terrains, including mountainous, woodland, and other complex terrains. They are widely used for the detection of unexploded ordnance (UXO). As the core component of the portable TEM system, the sensor is constructed with a transmitting coil and a receiving coil. Based on the primary field of the transmitting coil and internal noise of the receiving coil, the design and testing of such a sensor is described in detail. Results indicate that the primary field of the transmitting coil depends on the diameter, mass, and power of the coil. A higher mass-power product and a larger diameter causes a stronger primary field. Reducing the number of turns and increasing the clamp voltage reduces the switch-off time of the transmitting current effectively. Increasing the cross-section of the wire reduces the power consumption, but greatly increases the coil's weight. The study of the receiving coil shows that the internal noise of the sensor is dominated by the thermal noise of the damping resistor. Reducing the bandwidth of the system and increasing the size of the coil reduces the internal noise effectively. The cross-sectional area and the distance between the sections of the coil have little effect on the internal noise. A less damped state can effectively reduce signal distortion. Finally, a portable TEM sensor with both a transmitting coil (constructed with a diameter, number of turns, and transmitting current of 0.5 m, 30, and 5 A, respectively) and a receiving coil (constructed with a length and resonant frequency of 5.6 cm and 50 kHz, respectively) was built. The agreement between experimental and calculated results confirms the theory used in the sensor design. The responses of an 82 mm mortar shell at different distances were measured and inverted by the differential evolution (DE) algorithm to verify system performance. Results show that the sensor designed in this study can not only detect the 82 mm mortar shell within 1.2 m effectively but also locate the target precisely.

Raised levels of metal ions in the blood in patients who have undergone uncemented metal-on-polyethylene Trident-Accolade total hip replacement.

PubMed

Craig, P; Bancroft, G; Burton, A; Collier, S; Shaylor, P; Sinha, A

2014-01-01

The issues surrounding raised levels of metal ions in the blood following large head metal-on-metal total hip replacement (THR), such as cobalt and chromium, have been well documented. Despite the national popularity of uncemented metal-on-polyethylene (MoP) THR using a large-diameter femoral head, few papers have reported the levels of metal ions in the blood following this combination. Following an isolated failure of a 44 mm Trident-Accolade uncemented THR associated with severe wear between the femoral head and the trunnion in the presence of markedly elevated levels of cobalt ions in the blood, we investigated the relationship between modular femoral head diameter and the levels of cobalt and chromium ions in the blood following this THR. A total of 69 patients received an uncemented Trident-Accolade MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean age 67.0 years) were recruited and had levels of cobalt and chromium ions in the blood measured between May and June 2012. The patients were then divided into three groups according to the diameter of the femoral head used: 12 patients in the 28 mm group (controls), 18 patients in the 36 mm group and 13 patients in the 40 mm group. A total of four patients had identical bilateral prostheses in situ at phlebotomy: one each in the 28 mm and 36 mm groups and two in the 40 mm group. There was a significant increase in the mean levels of cobalt ions in the blood in those with a 36 mm diameter femoral head compared with those with a 28 mm diameter head (p = 0.013). The levels of cobalt ions in the blood were raised in those with a 40 mm diameter head but there was no statistically significant difference between this group and the control group (p = 0.152). The levels of chromium ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we have stopped using femoral heads with a diameter of ≤ 36 mm, and await further larger studies to clarify whether, for instance, this issue particularly affects this combination of components.

A three-dimensional finite element evaluation of magnetic attachment attractive force and the influence of the magnetic circuit.

PubMed

Kumano, Hirokazu; Nakamura, Yoshinori; Kanbara, Ryo; Takada, Yukyo; Ochiai, Kent T; Tanaka, Yoshinobu

2014-01-01

The finite element method has been considered to be excellent evaluative technique to study magnetic circuit optimization. The present study analyzed and quantitatively evaluated the different effects of magnetic circuit on attractive force and magnetic flux density using a three-dimensional finite element method for comparative evaluation. The diameter of a non-magnetic material in the shield disk of a magnetic assembly was variably increased by 0.1 mm to a maximum 2.0 mm in this study design. The analysis results demonstrate that attractive force increases until the diameter of the non-magnetic spacing material reaches a diameter of 0.5 mm where it peaks and then decreases as the overall diameter increases over 0.5 mm. The present analysis suggested that the attractive force for a magnetic attachment is optimized with an appropriate magnetic assembly shield disk diameter using a non-magnetic material to effectively change the magnetic circuit efficiency and resulting retention.

Clinical evidence on titanium-zirconium dental implants: a systematic review and meta-analysis.

PubMed

Altuna, P; Lucas-Taulé, E; Gargallo-Albiol, J; Figueras-Álvarez, O; Hernández-Alfaro, F; Nart, J

2016-07-01

The use of titanium implants is well documented and they have high survival and success rates. However, when used as reduced-diameter implants, the risk of fracture is increased. Narrow diameter implants (NDIs) of titanium-zirconium (Ti-Zr) alloy have recently been developed (Roxolid; Institut Straumann AG). Ti-Zr alloys (two highly biocompatible materials) demonstrate higher tensile strength than commercially pure titanium. The aim of this systematic review was to summarize the existing clinical evidence on dental NDIs made from Ti-Zr. A systematic literature search was performed using the Medline database to find relevant articles on clinical studies published in the English language up to December 2014. Nine clinical studies using Ti-Zr implants were identified. Overall, 607 patients received 922 implants. The mean marginal bone loss was 0.36±0.06mm after 1 year and 0.41±0.09mm after 2 years. The follow-up period ranged from 3 to 36 months. Mean survival and success rates were 98.4% and 97.8% at 1 year after implant placement and 97.7% and 97.3% at 2 years. Narrow diameter Ti-Zr dental implants show survival and success rates comparable to regular diameter titanium implants (>95%) in the short term. Long-term follow-up clinical data are needed to confirm the excellent clinical performance of these implants. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Ovum pick-up in sheep: a comparison between different aspiration devices for optimal oocyte retrieval.

PubMed

Rodríguez, C; Anel, L; Alvarez, M; Anel, E; Boixo, J C; Chamorro, C A; de Paz, P

2006-04-01

In vivo ovum pick-up (OPU) in sheep may be improved with a proper choice of aspiration elements (needle and tubing) and aspiration vacuum pressure. In the present study, two experiments were carried out. In Expt 1, visible follicles in ovaries of slaughtered ewes (treated separately according to their diameters: small<3 mm, medium 3-5 mm and large>5 mm) were aspirated using different combinations of the three studied factors such as aspiration flow rate (10, 20, 30, 40 and 50 ml water/min), needle gauge (18 and 20 G) and tubing inner diameter (1, 2 or 3 mm internal diameter). In Expt 2, a study with two 18 G needles of different lengths (18 G: 82 mm; 18 GL: 600 mm) was carried out, using ovaries obtained post-mortem, and performing in vivo laparoscopic follicular aspiration on ewes. We considered good quality oocytes as those with both complete compact cumulus and a homogeneous cytoplasm. Recovery rate, proportion of good quality oocytes (good quality oocytes/100 oocytes recovered) and overall efficiency (good quality oocytes/100 follicles aspirated) were noted. In Expt 1, aspiration flow rate affect remarkable proportion of good quality oocytes (69.5%, 50.5%, 44.8%, 36.5% and 28.3% for flows from 10 to 50 ml/min respectively, p<0.05). Needle gauge did not affect aspiration device efficiency. Thin and intermediate tubings were more effective (overall efficiency rates: 34.9%, 32.3% and 28.1% for 1, 2 and 3 mm respectively, p<0.05). Follicle size did not affect recovery rate, but proportion of good quality oocytes was higher for large (77.9%) and medium (64.4%) follicles (p<0.05). Finally, some combinations of the aspiration device showed greater effectiveness. In Expt 2, needle length did not influence recovery rate, but good quality oocytes rate was significantly modified both post-mortem and in vivo (good quality rate for 18 G vs 18 GL needles: 69.5% vs 47.7% and 58.1% vs 25.4%, post-mortem and in vivo respectively, p<0.05). We conclude that low-aspiration flow rates (10 and 20 ml/min) with thin or intermediate tubings (1 and 2 mm), and any short needle (18 G or 20 G) are the most adequate aspiration factors for OPU in sheep.

Residual stress measurements via neutron diffraction of additive manufactured stainless steel 17-4 PH.

PubMed

Masoomi, Mohammad; Shamsaei, Nima; Winholtz, Robert A; Milner, Justin L; Gnäupel-Herold, Thomas; Elwany, Alaa; Mahmoudi, Mohamad; Thompson, Scott M

2017-08-01

Neutron diffraction was employed to measure internal residual stresses at various locations along stainless steel (SS) 17-4 PH specimens additively manufactured via laser-powder bed fusion (L-PBF). Of these specimens, two were rods (diameter=8 mm, length=80 mm) built vertically upward and one a parallelepiped (8×80×9 mm 3 ) built with its longest edge parallel to ground. One rod and the parallelepiped were left in their as-built condition, while the other rod was heat treated. Data presented provide insight into the microstructural characteristics of typical L-PBF SS 17-4 PH specimens and their dependence on build orientation and post-processing procedures such as heat treatment. Data have been deposited in the Data in Brief Dataverse repository (doi:10.7910/DVN/T41S3V).

Small incision guarded hydroaspiration of iris lesions.

PubMed

Singh, Arun D

2017-11-01

To describe the technique and results of a minimally invasive surgical technique for resection of small iris lesions. Consecutive case series of 22 patients with localised, small iris lesions that were resected using the described surgical technique that composed of multiple, small corneal incisions created to allow for internal iris resection with 23-gauge horizontal vitrectomy scissors, followed by guarded tumour aspiration through a clear plastic tubing (diameter 3.5 mm) primed with viscoelastic agent. The mean largest basal diameter was 3.0 mm (range 1.5-5.0 mm; median 3.0 mm) and mean thickness was 1.3 mm (range 0.5-2.5 mm; median 1.0 mm). Use of multiple (2-4) small corneal incisions (range 2.0-3.0 mm; mean 2.8 mm) allowed reduced postoperative morbidity (significant hyphema (0%), hypotony (0%), wound leak (0%), >2 line change in best corrected visual acuity at postoperative 1 week (4.5%) and mean corneal astigmatism of 1.0 D (range 0.14-2.99 D; median 0.8 D) at postoperative 4-12 weeks. The tumour could be resected with clear surgical margins in all neoplastic cases (benign (2), borderline (1) and malignant (16)). Local recurrence or metastases were not observed in any melanoma case over a mean follow-up of 33.0 months (range 1.0-90.0 months; median 33.5 months). Small incision guarded hydroaspiration is a minimally invasive surgical technique for resection of select small iris lesions. Use of multiple small corneal incisions avoids morbidity associated with a single large corneoscleral incision, and use of guarded aspiration may eliminate the risk of wound contamination by the malignant tumour. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Angiographic predictors of 3-year patency of bypass grafts implanted on the right coronary artery system: a prospective randomized comparison of gastroepiploic artery, saphenous vein, and right internal thoracic artery grafts.

PubMed

Glineur, David; D'hoore, William; de Kerchove, Laurent; Noirhomme, Philippe; Price, Joel; Hanet, Claude; El Khoury, Gebrine

2011-11-01

Saphenous vein, in situ right gastroepiploic artery, and right internal thoracic artery grafts are routinely used to revascularize the right coronary artery. Little is known about the predictive value of objective preoperative angiographic parameters on midterm graft patency. We prospectively enrolled 210 consecutive patients undergoing coronary revascularization. Revascularization of the right coronary artery was randomly performed with the saphenous vein grafts in 81 patients and the right gastroepiploic artery in 92 patients. During the same study period, 37 patients received right coronary artery revascularization with the right internal thoracic artery used in a Y-composite fashion. All patients underwent a protocol-driven coronary angiogram 3 years after surgery. Preoperative angiographic parameters included minimum lumen diameter percent stenosis measured by quantitative angiography. A graft was considered "not functional" with patency scores of 0 to 2 and "functional" with patency scores of 3 or 4. Angiographic follow-up was 100% complete. A significant difference in the distribution of flow patterns was observed in the 3 groups. In multivariate analysis, the use of a saphenous vein graft was associated with superior graft functionality compared with the other conduits (odds ratio, 6.1; 95% confidence interval, 2.4-15). Graft function was negatively influenced by the minimum lumen diameter (odds ratio, 0.11; confidence interval, 0.05-0.25). In the right gastroepiploic artery and right internal thoracic artery groups, the proportion of functional grafts was higher when the minimum lumen diameter was below a threshold value in the third minimum lumen diameter quartile (0.64-1.30 mm). Preoperative angiography predicts graft patency in the right gastroepiploic artery and right internal thoracic artery, whereas the flow pattern in saphenous vein grafts is significantly less influenced by quantitative angiographic parameters. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Influence of glenoid component design and humeral component retroversion on internal and external rotation in reverse shoulder arthroplasty: a cadaver study.

PubMed

Berhouet, J; Garaud, P; Favard, L

2013-12-01

A common disadvantage of reverse shoulder arthroplasty is limitation of the range of arm rotation. Several changes to the prosthesis design and implantation technique have been suggested to improve rotation range of motion (ROM). Glenoid component design and degree of humeral component retroversion influence rotation ROM after reverse shoulder arthroplasty. The Aequalis Reversed™ shoulder prosthesis (Tornier Inc., Edina, MN, USA) was implanted into 40 cadaver shoulders. Eight glenoid component combinations were tested, five with the 36-mm sphere (centred seating, eccentric seating, inferior tilt, centred with a 5-mm thick lateralised spacer, and centred with a 7-mm thick lateralised spacer) and three with the 42-mm sphere (centred with no spacer or with a 7-mm or 10-mm spacer). Humeral component position was evaluated with 0°, 10°, 20°, 30°, and 40° of retroversion. External and internal rotation ROMs to posterior and anterior impingement on the scapular neck were measured with the arm in 20° of abduction. The large glenosphere (42 mm) was associated with significantly (P<0.05) greater rotation ROMs, particularly when combined with a lateralised spacer (46° internal and 66° external rotation). Rotation ROMs were smallest with the 36-mm sphere. Greater humeral component retroversion was associated with a decrease in internal rotation and a significant increase (P<0.05) in external rotation. The best balance between rotation ROMs was obtained with the native retroversion, which was estimated at 17.5° on average in this study. Our anatomic study in a large number of cadavers involved a detailed and reproducible experimental protocol. However, we did not evaluate the variability in scapular anatomy. Earlier studies of the influence of technical parameters did not take humeral component retroversion into account. In addition, no previous studies assessed rotation ROMs. Rotation ROM should be improved by the use of a large-diameter glenosphere with a spacer to lateralise the centre of rotation of the gleno-humeral joint, as well as by positioning the humeral component at the patient's native retroversion value. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Miniature fiber optic loop subcomponent for compact sensors and dense routing

NASA Astrophysics Data System (ADS)

Gillham, Frederick J.; Stowe, David W.; Ouellette, Thomas R.; Pryshlak, Adrian P.

1999-05-01

Fiber optic data links and embedded sensors, such as Fabry- Perot and Mach-Zehnders, are important elements in smart structure architectures. Unfortunately, one problem with optical fiber is the inherent limit through which fibers and cables can be looped. A revolutionary, patented technology has been developed which overcomes this problem. Based on processing the fiber into low loss miniature bends, it permits routing the fiber to difficult areas, and minimizing the size of sensors and components. The minimum bend diameter for singlemode fiber is typically over two inches in diameter, to avoid light attenuation and limit stresses which could prematurely break the fiber. With the new miniature bend technology, bend diameters as small as 1 mm are readily achieved. One embodiment is a sub-component with standard singlemode fiber formed into a 180 degree bend and packaged in a glass tube only 1.5 mm OD X 8 mm long, Figure 1. Measured insertion loss is less than 0.2 dB from 1260 nm to 1680 nm. A final processing step which anneals the fiber into the eventual curvature, reduces the internal stress, thereby resulting in long life expectancy with robust immunity to external loading. This paper addresses the optical and physical performance of the sub-component. Particular attention is paid to attenuation spectra, polarization dependent loss, reflectance, thermal cycle, damp heat, and shock tests. Applications are presented which employs the bend technology. Concatenating right angle bends into a 'wire harness' demonstrates the ability to route fiber through a smart engine or satellite structure. Miniature optical coils are proposed for sensors and expansion joints.

Transcatheter closure of moderate-to-large patent ductus arteriosus in infants using Amplatzer duct occluder.

PubMed

Wang, Jou-Kou; Wu, Mei-Hwan; Lin, Ming-Tai; Chiu, Shuenn-Nan; Chen, Chun-An; Chiu, Hsin-Hui

2010-02-01

There are difficulties in transcatheter closure of patent ductus arteriosus (PDA) in infants. The 46 infants (mean age 6.2+/-2.7 months; mean body weight 6.3+/-1.6 kg) who underwent PDA closure using the Amplatzer duct occluder (ADO). The indication for using an ADO was a ductus diameter > or =2.5 or 3 mm. Device diameter selected was 1-3 mm larger than ductal diameter. The mean systolic pulmonary artery pressure was 40.9+/-18.2 mmHg. The mean Qp/Qs ratio was 3.1+/-1.2. The mean ductus diameter was 3.3+/-0.8 mm. ADO was successfully deployed in 45 patients. Failure occurred in 1 case. The mean diameter of device used was 5.4+/-1.1 mm. No severe complications occurred. At the 1-month echocardiographic follow-up, a small residual shunt was present in 4 of 45 patients and had disappeared in all 4 patients at the 3-month follow-up. One patient developed a moderate degree of left ventricular outflow tract obstruction 2.3 years after the procedure. Transcatheter closure of PDA in infants using the ADO is a safe and effective method.

Rapid sealing of porcine renal blood vessels, ex vivo, using a high power, 1470-nm laser, and laparoscopic prototype

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Hutchens, Thomas C.; Larson, Eric R.; Gonzalez, David A.; Chang, Chun-Hung; Nau, William H.; Fried, Nathaniel M.

2017-05-01

Energy-based, radiofrequency (RF) and ultrasonic (US) devices currently provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternate energy modality for vessel sealing, capable of generating less collateral thermal damage. Previous studies demonstrated feasibility of sealing vessels in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for testing in open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices currently in surgical use was developed, and performance tests were conducted on porcine renal blood vessels, ex vivo. The 5-mm outer-diameter laparoscopic prototype featured a traditional Maryland jaw configuration that enables tissue manipulation and blunt dissection. Laser energy was delivered through a 550-μm-core-diameter optical fiber with side-delivery from the lower jaw and beam dimensions of 18-mm length×1.2-mm width. The 1470-nm diode laser delivered 68 W with 3-s activation time, consistent with vessel seal times associated with RF and US-based devices. A total of 69 fresh porcine renal vessels with mean diameter of 3.3±1.7 mm were tested, ex vivo. Vessels smaller than 5-mm diameter were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038±474 mmHg. Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174±221 mmHg. Seal width, thermal damage zone, and thermal spread averaged 1.7±0.8, 3.4±0.7, and 1.0±0.4 mm, respectively. Results demonstrated that the 5-mm optical laparoscopic prototype consistently sealed vessels less than 5-mm diameter with low thermal spread. Further in vivo studies are planned to test the performance across a variety of vessels and tissues.

Impact of water drops on small targets

NASA Astrophysics Data System (ADS)

Rozhkov, A.; Prunet-Foch, B.; Vignes-Adler, M.

2002-10-01

The collision of water drops against small targets was studied experimentally by means of a high-speed photography technique. The drop impact velocity was about 3.5 m/s. Drop diameters were in the range of 2.8-4.0 mm. The target was a stainless steel disk of 3.9 mm diameter. The drop spread beyond the target like a central cap surrounded by a thin, slightly conical lamella bounded by a thicker rim. By mounting a small obstacle near the target, surface-tension driven Mach waves in the flowing lamella were generated, which are formally equivalent to the familiar compressibility driven Mach waves in gas dynamics. From the measurement of the Mach angle, the values of some flow parameters could be obtained as functions of time, which provided insight into the flow structure. The liquid flowed from the central cap to the liquid rim through the thin lamella at constant momentum flux. At a certain stage of the process, most of the liquid accumulated in the rim and the internal part of the lamella became metastable. In this situation, a rupture wave propagating through the metastable internal part of the lamella caused the rim to retract while forming outwardly directed secondary jets. The jets disintegrated into secondary droplets due to the Savart-Plateau-Rayleigh instability. Prior to the end of the retraction, an internal circular wave of rupture was formed. It originated at the target and then it propagated to meet the retracting rim. Their meeting resulted in a crown of tiny droplets. A theoretical analysis of the ejection process is proposed.

2ND International Workshop on Adaptive Optics for Industry and Medicine.

DTIC Science & Technology

2000-02-08

The spots are well-separated, and there are only very weak interference peaks between adjacent spots, so identification of the spots is easy and...for transmission through an interference filter, a polarizing filter, the SLM, and a 12 mm diameter aperture to mask the active area in the SLM. A... interfere greatly with the visibility of the primary image. However, as the SLM power increases so does the contrast of the secondary images and

Human Paraoxonase Double Mutants Hydrolyze V and G Class Organophosphorus Nerve Agents

DTIC Science & Technology

2013-01-01

5]. It has been identified as a candidate enzyme for developing 0009-2797/$ - see front matter Published by Elsevier Ireland Ltd. http://dx.doi.org...toluidine salt (BCIP) and nitro-blue tetrazo- lium chloride (NBT) reagent (Sigma), identifying AP activity. Western blots were scanned with an EPSON...was a 20 m 0.25 mm internal diameter Astec G-TA Chiraldex c-cyclo- dextrin trifluoroacetyl column, 0.12 lm film thickness (Supelco, Bellefont, PA

Gate simulation of Compton Ar-Xe gamma-camera for radionuclide imaging in nuclear medicine

NASA Astrophysics Data System (ADS)

Dubov, L. Yu; Belyaev, V. N.; Berdnikova, A. K.; Bolozdynia, A. I.; Akmalova, Yu A.; Shtotsky, Yu V.

2017-01-01

Computer simulations of cylindrical Compton Ar-Xe gamma camera are described in the current report. Detection efficiency of cylindrical Ar-Xe Compton camera with internal diameter of 40 cm is estimated as1-3%that is 10-100 times higher than collimated Anger’s camera. It is shown that cylindrical Compton camera can image Tc-99m radiotracer distribution with uniform spatial resolution of 20 mm through the whole field of view.

Electronographic cameras for space astronomy.

NASA Technical Reports Server (NTRS)

Carruthers, G. R.; Opal, C. B.

1972-01-01

Magnetically-focused electronographic cameras have been under development at the Naval Research Laboratory for use in far-ultraviolet imagery and spectrography, primarily in astronomical and optical-geophysical observations from sounding rockets and space vehicles. Most of this work has been with cameras incorporating internal optics of the Schmidt or wide-field all-reflecting types. More recently, we have begun development of electronographic spectrographs incorporating an internal concave grating, operating at normal or grazing incidence. We also are developing electronographic image tubes of the conventional end-window-photo-cathode type, for far-ultraviolet imagery at the focus of a large space telescope, with image formats up to 120 mm in diameter.

Successful embolization using interlocking detachable coils for a congenital extrahepatic portosystemic venous shunt in a child.

PubMed

Yamagami, Takuji; Yoshimatsu, Rika; Matsumoto, Tomohiro; Terayama, Koshi; Nishiumra, Akira; Maeda, Yousuke; Nishimura, Tsunehiko

2007-11-01

The authors report the case of a 6-year-old boy with a congenital extrahepatic portosystemic venous shunt. He had hyperammonemia. The shunt was 18 mm in diameter and located between the inferior mesenteric vein and the left internal iliac vein. The flow in the shunt was very rapid. After decreasing blood flow by inflating a balloon catheter inserted into the left internal iliac vein from the femoral vein, a microcatheter was coaxially advanced to the shunt to embolize the shunt. Embolization was successfully performed with interlocking detachable coils and microcoils without any complication. This patient's hyperammonemia resolved soon after the procedure.

Development of internal magnetic probe for current density profile measurement in Versatile Experiment Spherical Torus

NASA Astrophysics Data System (ADS)

Yang, J.; Lee, J. W.; Jung, B. K.; Chung, K. J.; Hwang, Y. S.

2014-11-01

An internal magnetic probe using Hall sensors to measure a current density profile directly with perturbation of less than 10% to the plasma current is successfully operated for the first time in Versatile Experiment Spherical Torus (VEST). An appropriate Hall sensor is chosen to produce sufficient signals for VEST magnetic field while maintaining the small size of 10 mm in outer diameter. Temperature around the Hall sensor in a typical VEST plasma is regulated by blown air of 2 bars. First measurement of 60 kA VEST ohmic discharge shows a reasonable agreement with the total plasma current measured by Rogowski coil in VEST.

Retention of internal anchor tags by juvenile striped bass

USGS Publications Warehouse

Van Den Avyle, M.J.; Wallin, J.E.

2001-01-01

We marked hatchery-reared striped bass Morone saxatilis (145-265 mm total length) with internal anchor tags and monitored retention for 28 months after stocking in the Savannah River, Georgia and South Carolina. Anchor tags (with an 18-mm, T-shaped anchor and 42-mm streamer) were surgically implanted ventrally, and coded wire tags (1 mm long and 0.25 mm in diameter) were placed into the cheek muscle to help identify subsequent recaptures. The estimated probability of retention (SD) of anchor tags was 0.94 (0.05) at 4 months, 0.64 (0.13) at 16 months, and 0.33 (0.19) at 28 months. Of 10 fish recaptured with only coded wire tags, 5 showed an externally visible wound or scar near the point of anchor tag insertion. The incidence of wounds or scars, which we interpreted as evidence of tag shedding, increased to 50% in recaptures taken at 28 months (three of six fish). Our estimates for retention of anchor tags were generally lower than those in other studies of striped bass, possibly because of differences in the style of anchor or sizes of fish used. Because of its low rate of retention, the type of anchor tag we used may not be suitable for long-term assessments of stock enhancement programs that use striped bass of the sizes we evaluated.

Analysis of mandibular second molars with fused roots and shallow radicular grooves by using micro-computed tomography.

PubMed

Amoroso-Silva, Pablo; De Moraes, Ivaldo Gomes; Marceliano-Alves, Marilia; Bramante, Clovis Monteiro; Zapata, Ronald Ordinola; Hungaro Duarte, Marco Antonio

2018-01-01

This study aimed to describe the morphological and morphometric aspects of fused mandibular second molars with radicular shallow grooves using micro-computed tomography (CT). Eighty-eight mandibular second molars with fused roots were scanned in a micro-CT scanner at a voxel size of 19.6 μm. After reconstruction, only molars without C-shaped roots and presenting shallow radicular grooves were selected. 30 molars were chosen for further analysis. Canal cross-sections were classified according to Fan's modified classification (C1, C2, C3, and C4) and morphometric parameters at the apical region, examination of accessory foramina and tridimensional configuration were evaluated. Three-dimensional reconstructions indicated a higher prevalence of merging type ( n = 22). According to Fan's modified classification, the C4 configuration was predominant in the 3 apical mm. Roundness median values revealed a more round-shaped canals at 3 mm (0.72) than at 2 (0.63) and 1 (0.61) mm from the apex. High values of major and minor diameters were observed in the canals of these evaluated sections. In addition, few accessory apical foramina were observed at 1 and 2 mm from the apex. The average distance between last accessory foramina and the anatomic apex was 1.17 mm. A less complex internal anatomy is found when a mandibular second molar presents fused roots with shallow radicular grooves. The merging type canal was frequently observed. Moreover, the C4 configuration was predominant at a point 3 mm from the apex and presented rounded canals, large apical diameters, and few accessory foramina. The cervical and middle thirds presented C3 and C1 canal configurations most frequently. A minor morphological complexity is found when fused mandibular second molars present shallow radicular grooves.

Micro-Computed Tomography Analysis of the Root Canal Morphology of Palatal Roots of Maxillary First Molars.

PubMed

Marceliano-Alves, Marília; Alves, Flávio Rodrigues Ferreira; Mendes, Daniel de Melo; Provenzano, José Claudio

2016-02-01

A thorough knowledge of root canal anatomy is critical for successful root canal treatments. This study evaluated the internal anatomy of the palatal roots of maxillary first molars with micro-computed tomography (microCT). The palatal roots of extracted maxillary first molars (n = 169) were scanned with microCT to determine several anatomic parameters, including main canal classification, lateral canal occurrence and location, degree of curvature, main foramen position, apical constriction presence, diameters 1 and 2 mm from the apex and 1 mm from the foramen, minor dentin thickness in those regions, canal volume, surface area, and convexity. All canals were classified as Vertucci type I. The cross sections were oval in 61% of the canals. Lateral canals were found in 25% of the samples. The main foramen did not coincide with the root apex in 95% of the cases. Only 8% of the canals were classified as straight. Apical constriction was identified in 38% of the roots. The minor and major canal diameters and minor dentin thickness were decreased near the apex. The minor dentin thickness 1 mm from the foramen was 0.82 mm. The palatal canals exhibited a volume of 6.91 mm(3) and surface area of 55.31 mm(2) and were rod-shaped. The root canals of the palatal roots were classified as type I. However, some factors need to be considered during the treatment of these roots, including the frequent ocurrence of moderate/severe curvatures, oval-shaped cross-sections, and lateral canals, noncoincidence of the apical foramen with the root apex, and absence of apical constriction in most cases. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Trunnionosis: Does Head Size Affect Fretting and Corrosion in Total Hip Arthroplasty?

PubMed

Del Balso, Christopher; Teeter, Matthew G; Tan, Sok Chuen; Howard, James L; Lanting, Brent A

2016-10-01

Wear and tribocorrosion at the modular head-neck taper interface may be a cause of failure in metal-on-polyethylene total hip arthroplasty (THA). The present investigation endeavored to elucidate the effect of femoral head diameter on fretting and corrosion in retrieved head-neck tapers. A retrieval analysis of THA prostheses in vivo for a minimum of 1 year was performed. Twenty-three femoral heads of 32-mm diameter were matched with 28-mm heads based on time in vivo and head length (-3 mm to +8 mm). All included implants featured a single taper design from a single manufacturer. Fretting and corrosion damage scoring was performed for each implant under stereomicroscopic visualization. Head diameter was observed to affect fretting (P = .01), with 32-mm femoral heads exhibiting greater total fretting scores than 28-mm heads. Fretting damage was greatest (P = .01) in the central concentric zone of the femoral head bore tapers, regardless of head diameter, length, or stem offset. No significant effect on total corrosion scores was observed for any head or stem variable. Retrieved implant total corrosion scores were positively correlated (ρ = 0.51, P < .001) with implantation time. Increased femoral head diameter in THA may produce greater fretting damage owing to and increased head-neck moment arm. There is no associated increase in corrosion with 28-mm and 32-mm heads of this taper design. The longer a THA prosthesis is implanted, the greater the risk of damage due to corrosion. Copyright © 2016 Elsevier Inc. All rights reserved.

Transfer and development length of 15.2 mm (0.6 in.) diameter prestressing strand in high performance concrete : results of the Hoblitzell-Buckner beam tests

DOT National Transportation Integrated Search

1995-06-01

This study examines the transfer and development length of 15.2 mm (0.6 in.) diameter prestressing strand in high performance (high strength) concrete. Two 1067 mm (42.0 in.) deep rectangular beams, commonly called the Hoblitzell-Buckner beams, each ...

Effects of Mitral Annulus Remodeling Following MitraClip Procedure on Reduction of Functional Mitral Regurgitation.

PubMed

Hidalgo, Francisco; Mesa, Dolores; Ruiz, Martín; Delgado, Mónica; Rodríguez, Sara; Pardo, Laura; Pan, Manuel; López, Amador; Romero, Miguel A; Suárez de Lezo, José

2016-11-01

The percutaneous mitral valve repair procedure (MitraClip) appears to reduce mitral annulus diameter in patients with functional mitral regurgitation, but the relationship between this and regurgitation severity has not been demonstrated. The aim of this study was to determine the effect of mitral annulus remodeling on the reduction of mitral regurgitation in patients with functional etiology. The study included all patients with functional mitral regurgitation treated with MitraClip at our hospital until January 2015. Echocardiogram (iE33 model, Philips) was performed in all patients immediately after device positioning. Changes in the mitral annulus correlated with mitral regurgitation severity, as assessed using the effective regurgitant orifice area. The study included 23 patients (age, 65±14 years; 74% men; left ventricular ejection fraction, 31%±13%; systolic pulmonary artery pressure, 47±10 mmHg). After the procedure, the regurgitant orifice area decreased by 0.30 cm 2 ±0.04 cm 2 (P<.0005), from a baseline of 0.49 cm 2 ±0.09 cm 2 . Anteroposterior diameter decreased by 3.14 mm±1.01 mm (P<.0005) from a baseline of 28.27 mm±4.9 mm, with no changes in the intercommissural diameter (0.50 mm±0.91 mm vs 40.68 mm±4.7 mm; P=.26). A significant association was seen between anteroposterior diameter reduction and regurgitant orifice area reduction (r=.49; P=.020). In patients with functional mitral regurgitation, the MitraClip device produces an immediate reduction in the anteroposterior diameter. This remodeling may be related to the reduction in mitral regurgitation. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Mean Normal Portal Vein Diameter Using Sonography among Clients Coming to Radiology Department of Jimma University Hospital, Southwest Ethiopia.

PubMed

Geleto, Gemechu; Getnet, Wondim; Tewelde, Tsegaye

2016-05-01

Mean portal vein diameter is considered as the best indicator for portal hypertension. However, the cutoff point differs from study to study (above 10-15 mm) despite the existence of normal mean portal vein diameter between 10-15 mm in different settings.This implies the existence of limited evidence on normal portal vein diameter for all populations in all countries prior to setting the cutoff points. Therefore, the aim of this study was sonographic assessment of normal mean portal vein diameter among patients referred to The Department of Radiology in Jimma University Hospital. A facility based cross-sectional study was conducted from November to December 2014 at Jimma University Hospital on a total of 195 clients. Data about portal vein diameter for eligible clients were collected by radiologists using Sonography. Data were edited manually, entered and analyzed using SPSS version 16. Data were collected from a total of 195 participants. Among these, 121(62.1%) were males and the median age of the participants was 35 years. The study revealed a normal mean portal vein diameter of 10.6 mm ±1.8 SD with a respirophasic variation of 25.6%. Likewise, the normal mean portal vein diameter seemed to have varied significantly by age and sex. The study revealed a normal mean portal vein diameter ranging below 13 mm. Hence, decisions made in clinical settings should base on these findings. Besides, there is a need for large scale study to determine portal vein diameter variation by age and sex, controlling other confounders.

A new Doppler-echo method to quantify regurgitant volume.

PubMed

Wang, S S; Rubenstein, J J; Goldman, M; Sidd, J J

1992-01-01

An in vitro technique using color flow imaging and continuous wave Doppler was developed to measure the initial regurgitant flow jet diameter and velocity integral to yield the parameters for a volume calculation. Jets were produced by volume-controlled injection through tubes of various diameters (1.3, 1.9, 2.8, and 3.5 mm) to deliver volumes from 1 to 7 ml over 100 to 300 msec at pressures from 40 to 200 mm Hg. One hundred forty-five samples were obtained. Flow jet diameter consistently overestimated tube diameter by 2 mm when injected volume was 1.5 to 7 ml and by 1.5 mm when injected volume was less than 1.5 ml. This offset was stable with various transducers (2.5, 3.5, 5.0 MHz) at normal gain setting (just under noise). Therefore, corrected flow jet diameter (FJD) = FJD - 2 mm, and Doppler volume = corrected flow jet area x velocity integral. A range of injectates from 1.1 to 7 ml generated Doppler volume of 1.0 to 8.2 ml. The relation between Doppler volume (DV) and injected volume (IV) was DV = 1.079 IV - 0.22, r2 = 0.945, p less than 0.01. This relation was not altered by tube diameter. Thus a method combining color flow imaging and continuous wave Doppler provides a reliable and accurate measure of in vitro flow volume.

Three-Dimensional Finite Element Analysis of the Stress Distribution at the Internal Implant-Abutment Connection.

PubMed

Cho, Sung-Yong; Huh, Yoon-Hyuk; Park, Chan-Jin; Cho, Lee-Ra

2016-01-01

This study investigated stress distribution in four different implant-abutment interface conditions in the internal tapered connection implant system. Four different implant diameters (3.5 mm, 4.0 mm, 4.5 mm, and 5.0 mm) and two abutment types (hexagonal and conical) were simulated. Four unique implant-abutment interface conditions were assumed based on wall thickness, mating surface length, distance to the vertical stop, and abutment shape. Axial and oblique loading was applied during abutment screw preload, and the Von Mises stresses were measured at the implant-abutment and abutment-screw interfaces. The implant-abutment interface stress decreased as the wall thickness increased. As the mating surface increased, the stress distribution trended downward, and when the distance to the implant vertical stop was 0 μm, the Von Mises stress was extremely high at the vertical stop. Despite their different shapes, the abutments showed similar stress distributions. However, the maximum Von Mises stress was higher in the conical connection than in the hexagonal connection, particularly at the contralateral side to loading. To decrease the stress distribution at the implant-abutment interface, the implant wall thickness, mating surface contact length, distance to the vertical stop, and abutment shape should be carefully considered.

7 CFR 51.2932 - Damage.

Code of Federal Regulations, 2012 CFR

2012-01-01

... apparent. (e) Scab spots when cracked or aggregating more than three-eighths inch (9.5 mm) in diameter. (f... scattered and aggregating more than one-fourth inch (6.3 mm) in diameter. (g) Hail when the skin has been...

7 CFR 51.2932 - Damage.

Code of Federal Regulations, 2010 CFR

2010-01-01

... apparent. (e) Scab spots when cracked or aggregating more than three-eighths inch (9.5 mm) in diameter. (f... scattered and aggregating more than one-fourth inch (6.3 mm) in diameter. (g) Hail when the skin has been...

7 CFR 51.2932 - Damage.

Code of Federal Regulations, 2011 CFR

2011-01-01

... apparent. (e) Scab spots when cracked or aggregating more than three-eighths inch (9.5 mm) in diameter. (f... scattered and aggregating more than one-fourth inch (6.3 mm) in diameter. (g) Hail when the skin has been...

50 CFR 648.144 - Gear restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Untreated hemp, jute, or cotton string of 3/16 inches (4.8 mm) diameter or smaller; or (ii) Magnesium alloy... following degradable materials: (A) Untreated hemp, jute, or cotton string of 3/16 inches (4.8 mm) diameter...

Platform switching: biomechanical evaluation using three-dimensional finite element analysis.

PubMed

Tabata, Lucas Fernando; Rocha, Eduardo Passos; Barão, Valentim Adelino Ricardo; Assunção, Wirley Goncalves

2011-01-01

The objective of this study was to evaluate, using three-dimensional finite element analysis (3D FEA), the stress distribution in peri-implant bone tissue, implants, and prosthetic components of implant-supported single crowns with the use of the platform-switching concept. Three 3D finite element models were created to replicate an external-hexagonal implant system with peri-implant bone tissue in which three different implant-abutment configurations were represented. In the regular platform (RP) group, a regular 4.1-mm-diameter abutment (UCLA) was connected to regular 4.1-mm-diameter implant. The platform-switching (PS) group was simulated by the connection of a wide implant (5.0 mm diameter) to a regular 4.1-mm-diameter UCLA abutment. In the wide-platform (WP) group, a 5.0-mm-diameter UCLA abutment was connected to a 5.0-mm-diameter implant. An occlusal load of 100 N was applied either axially or obliquely on the models using ANSYS software. Both the increase in implant diameter and the use of platform switching played roles in stress reduction. The PS group presented lower stress values than the RP and WP groups for bone and implant. In the peri-implant area, cortical bone exhibited a higher stress concentration than the trabecular bone in all models and both loading situations. Under oblique loading, higher intensity and greater distribution of stress were observed than under axial loading. Platform switching reduced von Mises (17.5% and 9.3% for axial and oblique loads, respectively), minimum (compressive) (19.4% for axial load and 21.9% for oblique load), and maximum (tensile) principal stress values (46.6% for axial load and 26.7% for oblique load) in the peri-implant bone tissue. Platform switching led to improved biomechanical stress distribution in peri-implant bone tissue. Oblique loads resulted in higher stress concentrations than axial loads for all models. Wide-diameter implants had a large influence in reducing stress values in the implant system.

Uncovering the Forgotten Effect of Superior Cervical Ganglia on Pupil Diameter in Subarachnoid Hemorrhage: An Experimental Study.

PubMed

Onen, Mehmet Resid; Yilmaz, Ilhan; Ramazanoglu, Leyla; Aydin, Mehmet Dumlu; Keles, Sadullah; Baykal, Orhan; Aydin, Nazan; Gundogdu, Cemal

2018-01-01

To investigate the relationship between neuron density of the superior cervical sympathetic ganglia and pupil diameter in subarachnoid hemorrhage. This study was conducted on 22 rabbits; 5 for the baseline control group, 5 for the SHAM group and 12 for the study group. Pupil diameters were measured via sunlight and ocular tomography on day 1 as the control values. Pupil diameters were re-measured after injecting 0.5 cc saline to the SHAM group, and autologous arterial blood into the cisterna magna of the study group. After 3 weeks, the brain, superior cervical sympathetic ganglia and ciliary ganglia were extracted with peripheral tissues bilaterally and examined histopathologically. Pupil diameters were compared with neuron densities of the sympathetic ganglia and ciliary ganglia which were examined using stereological methods. Baseline values were; normal pupil diameter 7.180±620 ?m and mean neuron density of the superior cervical sympathetic ganglia 6.321±510/mm3, degenerated neuron density of ciliary ganglia was 5±2/mm3 after histopathological examination in the control group. These values were measured as 6.850±578 ?m, 5.950±340/mm3 and 123±39/mm3 in the SHAM group and 9.910±840 ?m, 7.950±764/mm3 and 650±98/mm3 in the study group. A linear relationship was determined between neuron density of the superior cervical sympathetic ganglia and pupil diameters (p < 0.005). Degenerated ciliary ganglia neuron density had an inverse effect on pupil diameters in all groups (p < 0.0001). Highly degenerated neuron density of the ciliary ganglion is not responsible for pupil dilatation owing to parasympathetic pupilloconstrictor palsy, but high neuron density of the pupillodilatatory superior cervical sympathetic ganglia should be considered an important factor for pupil dilatation.

Experimental Evaluation of the Canadarm2 Residual Flexural Strength After an Orbital Debris Impact

NASA Astrophysics Data System (ADS)

Lanouette, Anne-Marie; Potvin, Marie-Josee; Martin, Francis; Mondor, Sylvain; Houle, Dany; Therriault, Daniel

2014-06-01

The risk for spacecraft structures of being hit by an orbital debris is constantly increasing due to the steadily augmenting number of objects sent to space while only a fraction of them are deorbited after use. Numerous studies have taken place to characterize the damage of a hypervelocity impact on a space structure; however the structural effect of such impact usually isn't investigated. Four cylindrical samples 35cm in diameter and 2.7mm in thickness of carbon fibers IM7/PEEK, representative of the Canadarm2 structure, covered by thermal blankets, have been subjected to hypervelocity impacts. Projectiles with diameters between 5.0 and 8.0mm and velocities between 6.9 and 7.2km/s were used for the tests. The visible and internal damage on the booms and on the thermal blankets was characterized. The damaged cylinders underwent fatigue bending loading with two different amplitudes to study the residual resistance of a laminate space structure after an orbital debris impact. Damage propagation was detected with the higher amplitude fatigue loading only.

Influence of Age and Apical Diameter on the Success of Endodontic Regeneration Procedures.

PubMed

Estefan, Bishoy Safwat; El Batouty, Kariem Mostafa; Nagy, Mohamed Mokhtar; Diogenes, Anibal

2016-11-01

Treatment of immature permanent teeth with necrotic pulp and apical pathosis constitutes a challenge for endodontists. The present study was done to evaluate the effect of age and apical diameter on the regenerative potential of young permanent immature teeth with necrotic pulps. Immature necrotic permanent maxillary incisors (n = 40) of patients 9-18 years old were divided into 2 groups according to the treatment protocol: group Y (younger age group), 9-13 years and group O (older age group), 14-18 years. Each group was further subdivided into 2 subgroups according to apical diameter, subgroup (n) (narrower diameter) between 0.5 and 1 mm and subgroup (w) (wider diameter) equal to or greater than 1 mm. Revascularization procedures were performed for all patients. Follow-up was done for up to 12 months. Standardized radiographs were digitally evaluated for increase in root length and thickness and decrease in apical diameter. After the follow-up period, most of the cases demonstrated radiographic evidence of periapical healing. Group Y showed significant progressive increase in root length and width and decrease in apical diameter. Subgroup (w) representing wider apical diameter showed significant progress as well. It was found that revascularization procedures can be implemented in any age ranging from 9 to 18 years; however, younger age groups were better candidates for revascularization procedure than older ones. Regarding the apical diameter, regeneration procedures were successful with apical diameters as small as 0.5 mm. However, teeth with preoperative wider diameters (≥1 mm) demonstrated greater increase in root thickness, length, and apical narrowing. Copyright © 2016 American Association of Endodontists. All rights reserved.

Performance Evaluation and Initial Clinical Test of the Positron Emission Mammography System (PEMi)

NASA Astrophysics Data System (ADS)

Li, Lin; Gu, Xiao-Yue; Li, Dao-Wu; Huang, Xian-Chao; Chai, Pei; Feng, Bao-Tong; Wang, Pei-Lin; Yun, Ming-Kai; Dai, Dong; Zhang, Zhi-Ming; Yin, Peng-Fei; Xu, Wen-Gui; Wei, Long

2015-10-01

A new polygon positron emission mammography imaging system (PEMi) was developed in 2009 by the Institute of High Energy Physics, Chinese Academy of Sciences. PEMi is constructed in a polygon structure with lutetium yttrium orthosilicate crystal arrays mounted on a position-sensitive photomultiplier. The system consists of 64 blocks and each block is arranged in 16 ×16 crystal arrays with a pixel size of 1.9 ×1.9 ×15 mm. The diameter of the detector ring is 166 mm, and the axial length is 128 mm. The transaxial field of view of PEMi is 110 mm. The goal of the initial study was to test PEMi's performance and the clinical imaging ability with a small group of selected subjects. The detectors have a measured intrinsic spatial resolution averaging 1.67 mm. The axial and tangential resolution remained under 2.5-mm full width at half maximum within the central 5-cm diameter of the field of view. The hot rods with a diameter of 1.7 mm can be clearly identified, and the structure of the region containing 1.35-mm diameter rods can also be observed. Using a 6-ns coincidence timing window and a 360 660-keV energy window, the peak sensitivity of the tomograph is 6.88%. The noise-equivalent count rate peak is 110 766 cps for a breast-like cylindrical phantom of 100 mm in diameter at an activity concentration of 0.03 MBq/cc. The recovery coefficients ranged from 0.21 to 0.85 for rods between 1 mm and 5 mm in the image-quality phantom. The reconstructed image resolution achieved an improvement compared with whole-body positron emission tomography (PET), which might reduce the lower threshold on detectable lesion size. Example patient images demonstrate that PEMi is clinically feasible. And more detailed structure information was obtained with PEMi than with the whole-body PET imaging.

Quantitative Gross and CT measurements of Cadaveric Cervical Vertebrae (C3 – C6) as Guidelines for the Lateral mass screw fixation

PubMed Central

Heinneman, Thomas E.; Conti, Mathew S.; Dossous, Paul-Michel F.; Dillon, David J.; Tsiouris, Apostolos J.; Pyo, Se Young; Mtui, Estomih P.; Härtl, Roger

2016-01-01

Background Lateral mass screw fixation is the treatment of choice for posterior cervical stabilization. Long or misdirected screws carry a risk of injury to spinal nerve roots or vertebral artery. This study was aimed to assess the gross anatomic and CT measurements of typical cervical vertebrae for the selection of lateral mass screws. Methods Dimensions of the articular pillars were measured on 1) Dry cervical vertebrae with Vernier calipers and 2) Multiplanar reformations of CT scans of the same vertebrae with Viewer software package. The data was statistically evaluated. Results The transverse diameter of the articular pillars with Vernier calipers varied from 6.0 to 15.4 mm (mean=10.5 mm ± 1.5) and on CT scans ranged from 8.2 – 16.1 mm (mean=11.6 mm ± 1.4). The antero-posterior diameter, an estimate of the screw length by Roy-Camille technique varied from 3.9 to 12.7 mm (mean=8.6 mm ± 1.6) by Vernier calipers and from 6.4 to 13.3 mm (mean=9.1 ± 1.2) on CT scans. The oblique AP diameter, an estimate of screw length by Magerl method varied from 10.8 to 20.3 mm (mean=14.9 mm ± 1.8) by Vernier calipers and from 11.4 to 19.3 mm (mean=14.5 mm ± 1.7) on CT. The CT measurements for height, transverse and AP diameter of the articular pillars were 0.5 - 1.0 mm larger than dimensions by Vernier calipers. No statistically significant difference was observed between the caliper and CT measurements for the oblique AP diameter. Conclusion CT measurements of the articular pillars may slightly overestimate the desired screw length selected by spine surgeons when compared to actual anatomy. Although means of the articular pillars correspond to the screw lengths used, substantial number of observations below 10 mm for Roy-Camille trajectory and below 14 mm for Magerl trajectory requires careful preoperative planning and intra-operative confirmation to avoid long/misdirected lateral mass screws. PMID:28377857

Differences in stone size and ureteral dilation between obstructing proximal and distal ureteral calculi.

PubMed

Eisner, Brian H; Pedro, Renato; Namasivayam, Saravanan; Kambadakone, Avinash; Sahani, Dushyant V; Dretler, Stephen P; Monga, Manoj

2008-09-01

To examine the differences in ureteral dilation and calculus size between obstructing proximal and distal ureteral stones. A retrospective review of computed tomography (CT) scans from 176 consecutive patients with obstructing ureteral calculi was performed. For the calculi, the axial diameter was defined as the largest stone diameter on the axial CT images, and the coronal length was defined as the cephalocaudal length of the stone measured on the coronal CT images. Univariate and multivariate statistical analyses were performed. A total of 65 proximal and 111 distal ureteral calculi were analyzed. On univariate analysis, the proximal calculi were associated with a greater degree of ureteral dilation (mean 6.1 mm vs 5.3 mm, P = .01) and had a greater coronal length (mean 9.9 mm vs 8.3 mm, P = .005) than distal calculi. This association was also true on the multivariate analysis, which controlled for age and sex (P = .0004). No statistically significant difference was found in the axial calculus diameter for the proximal and distal stones (mean 5.3 mm vs 5.0 mm, P = .29). In a subset of 50 patients whose contralateral ureters (without stones) were measured for control comparison, the ureteral dilation in the ureters with stones was significantly greater than in the control ureters (proximal ureter 6.2 mm vs 4.3 mm, P = .001; distal ureter 4.7 mm vs 3.8 mm, P = .004). For proximal calculi, 72.3% were associated with ureteral dilation of less than 7 mm, 23.1% with 7-10 mm, and 4.6% with greater than 10 mm. For the distal calculi, 90.1% were associated with ureteral dilation of less than 7 mm, 6.3% with 7-10 mm, and 3.6% with greater than 10 mm. The coronal length was the largest measured diameter in 94% of the calculi, and the mean calculus coronal length was significantly greater than the mean axial diameter (8.9 mm vs 5.1 mm, respectively, P < .001). The results of our study have shown that proximal ureteral calculi are associated with a significantly greater degree of ureteral dilation and larger coronal length than are distal calculi. These findings should guide the endoscopist in planning intracorporeal ureteroscopic lithotripsy. We suggest obtaining CT coronal images to more accurately characterize obstructing ureteral stones.

Relevance of impacter shape to nonvisible damage and residual tensile strength of a thick graphite/epoxy laminate

NASA Technical Reports Server (NTRS)

Poe, Clarence C., Jr.

1991-01-01

A study was made to determine the relevance of impacter shape to nonvisible damage and tensile residual strength of a 36 mm thick graphite/epoxy motor case. The shapes of the impacters were as follows: 12.7 mm and 25.4 mm diameter hemispheres, a sharp corner, and a 6.3 mm diameter bolt-like rod. The investigation revealed that damage initiated when the contact pressure exceeded a critical level. However, the damage was not visible on the surface until an even higher pressure was exceeded. The impact energy to initiate damage or cause visible damage on the surface increased approximately with impacter diameter to the third power. The reduction in strength for nonvisible damage increased with increasing diameter, 9 and 30 percent for the 12.7 mm and 25.4 mm diameter hemispheres, respectively. The corner impacter made visible damage on the surface for even the smallest impact energy. The rod impacter acted like a punch and sliced through the composite. Even so, the critical level of pressure to initiate damage was the same for the rod and hemispherical impacters. Factors of safety for nonvisible damage increased with increasing kinetic energy of impact. The effects of impacter shape on impact force, damage size, damage visibility, and residual tensile strength were predicted quite well assuming Hertzian contact and using maximum stress criteria and a surface crack analysis.

Fecal retention in childhood: Evaluation on ultrasonography.

PubMed

Hatori, Reiko; Tomomasa, Takeshi; Ishige, Takashi; Tatsuki, Maiko; Arakawa, Hirokazu

2017-04-01

To assess the usefulness of rectal diameter measurement on ultrasonography as a diagnostic tool for fecal retention in children. One hundred children (median age, 5.0 years), consisting of 80 with functional constipation and 20 without constipation, participated in the study. All patients underwent physical examination that included digital rectal examination. Forty-five children underwent ultrasonography in three differential planes: transection above the symphysis; under the ischial spine; and at the bladder neck. The measurement of the rectal diameter at the transection above the symphysis could most easily detect fecal retention and had the closest correlations with retention among the three planes. Rectal diameter was wider at all measuring points (35.2 vs 20.9 mm above the symphysis, P < 0.0001; 35.7 vs 24.0 mm under the ischial spine, P < 0.0001; and 19.4 vs 8.7 mm at the bladder neck, P < 0.0001) in children with fecal retention than in those with no fecal retention. With regard to presence of constipation, children with fecal retention had a wider rectal diameter above the symphysis than those with no fecal retention (children with functional constipation, 35.3 vs 20.0 mm, P < 0.0001; children without constipation: 32.6 vs 14.6 mm, P = 0.0026). The cut-off for the rectal diameter measured above the symphysis to identify fecal retention was 27 mm, with high sensitivity and specificity (95.5% and 94.1%, respectively). Ultrasound rectal diameter measurement can be used to detect fecal retention in children. © 2016 Japan Pediatric Society.

Development of a probe for inner profile measurement and flaw detection

NASA Astrophysics Data System (ADS)

Yoshizawa, Toru; Wakayama, Toshitaka; Kamakura, Yoshihisa

2011-08-01

It is one of the important necessities to precisely measure the inner diameter and/or the inner profile of pipes, tubes and other objects similar in shape. Especially in mechanical engineering field, there are many requests from automobile industry because the inner surface of engine blocks and other die casts are strongly required to be inspected and measured by non-contact methods (not by the naked eyes inspection using a borescope). If the inner diameter is large enough like water pipes or drain pipes, complicated and large equipment may be applicable. However, small pipes with a diameter ranging from 10mm to 100mm are difficult to be inspected by such a large instrument as is used for sewers inspection. And we have proposed an instrument which has no moving elements such as a rotating mirror or a prism for scanning a beam. Our measurement method is based on optical sectioning using triangulation. This optically sectioned profile of an inner wall of pipe-like objects is analyzed to produce numerical data of inner diameter or profile. Here, we report recent development of the principle and applications of the optical instrument with a simple and compact configuration. In addition to profile measurement, we found flaws and defects on the inner wall were also detected by using the similar principle. Up to now, we have developed probes with the diameter of 8mm to 25mm for small size objects and another probe (80 mm in diameter) for such a larger container with the dimensional size of 600mm.

Progressive mechanical indentation of large-format Li-ion cells

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

Wang, Hsin; Kumar, Abhishek; Simunovic, Srdjan

We used large format Li-ion cells to study the mechanical responses of single cells of thickness 6.5 mm and stacks of three cells under compressive loading. We carried out various sequences of increasing depth indentations using a 1.0 inch (25.4 mm) diameter steel ball with steel plate as a rigid support surface. The indentation depths were between 0.025 and 0.250 with main indentation increments tests of 0.025 steps. Increment steps of 0.100 and 0.005 were used to pinpoint the onset of internal-short that occurred between 0.245 and 0.250 . The indented cells were disassembled and inspected for internal damage. Loadmore » vs. time curves were compared with the developed computer models. Separator thinning leading to the short circuit was simulated using both isotropic and anisotropic mechanical properties. This study show that separators behave differently when tested as a single layer vs. a stack in a typical pouch cell. The collective responses of the multiple layers must be taken into account in failure analysis. A model that resolves the details of the individual internal cell components was able to simulate the internal deformation of the large format cells and the onset of failure assumed to coincide with the onset of internal short circuit.« less

Progressive mechanical indentation of large-format Li-ion cells

NASA Astrophysics Data System (ADS)

Wang, Hsin; Kumar, Abhishek; Simunovic, Srdjan; Allu, Srikanth; Kalnaus, Sergiy; Turner, John A.; Helmers, Jacob C.; Rules, Evan T.; Winchester, Clinton S.; Gorney, Philip

2017-02-01

Large format Li-ion cells were used to study the mechanical responses of single cells of thickness 6.5 mm and stacks of three cells under compressive loading. Various sequences of increasing depth indentations were carried out using a 1.0 inch (25.4 mm) diameter steel ball with steel plate as a rigid support surface. The indentation depths were between 0.025″ and 0.250″ with main indentation increments tests of 0.025″ steps. Increment steps of 0.100″ and 0.005″ were used to pinpoint the onset of internal-short that occurred between 0.245″ and 0.250″. The indented cells were disassembled and inspected for internal damage. Load vs. time curves were compared with the developed computer models. Separator thinning leading to the short circuit was simulated using both isotropic and anisotropic mechanical properties. Our study show that separators behave differently when tested as a single layer vs. a stack in a typical pouch cell. The collective responses of the multiple layers must be taken into account in failure analysis. A model that resolves the details of the individual internal cell components was able to simulate the internal deformation of the large format cells and the onset of failure assumed to coincide with the onset of internal short circuit.

Progressive mechanical indentation of large-format Li-ion cells

DOE PAGES

Wang, Hsin; Kumar, Abhishek; Simunovic, Srdjan; ...

2016-12-07

We used large format Li-ion cells to study the mechanical responses of single cells of thickness 6.5 mm and stacks of three cells under compressive loading. We carried out various sequences of increasing depth indentations using a 1.0 inch (25.4 mm) diameter steel ball with steel plate as a rigid support surface. The indentation depths were between 0.025 and 0.250 with main indentation increments tests of 0.025 steps. Increment steps of 0.100 and 0.005 were used to pinpoint the onset of internal-short that occurred between 0.245 and 0.250 . The indented cells were disassembled and inspected for internal damage. Loadmore » vs. time curves were compared with the developed computer models. Separator thinning leading to the short circuit was simulated using both isotropic and anisotropic mechanical properties. This study show that separators behave differently when tested as a single layer vs. a stack in a typical pouch cell. The collective responses of the multiple layers must be taken into account in failure analysis. A model that resolves the details of the individual internal cell components was able to simulate the internal deformation of the large format cells and the onset of failure assumed to coincide with the onset of internal short circuit.« less

The effect of load obliquity on the strength of locking and nonlocking constructs in synthetic osteoporotic bone.

PubMed

Tensmeyer, Daniel F; Gustafson, Peter A; Jastifer, James R; Patel, Bipin; Chess, Joseph L

2015-11-01

The biomechanical performance of internal fracture fixation depends on several factors. One measure of performance is the strength of the construct. The objective of this biomechanical study was to identify the effect of load obliquity on the strength of locking and nonlocking plate and screw constructs. For this study, plates and screws were fixed to synthetic osteoporotic bone that had a 1 mm thick synthetic cortical shell. An 8-hole, 3.5 mm thick hybrid plate was fixed with either two 3.5 mm major diameter locking screws or two 4.0 mm major diameter cancellous screws. Forces were applied at 0, 45, and 90 degrees to the plate normal. Eight specimens were loaded to failure for each group. When loads were applied normal to the plate, the nonlocking construct failed initially at higher loads (123.2 ± 13.2 N) than the locking construct (108.7 ± 7.6 N, P = 0.020). For oblique loads, the locking construct failed at higher mean loads but the difference of means was not statistically significant (167.7 ± 14.9 N compared to 154.2 ± 9.4 N, P = 0.052). For loads parallel to the plate, the locking construct was much stronger than the nonlocking construct (1591 ± 227 N compared to 913 ± 237 N, P < 0.001). Stiffness and Energy outcomes are also compared. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Effects of foreign object damage from small hard particles on the high-cycle fatigue life of titanium-(6)aluminum-(4)vanadium

NASA Astrophysics Data System (ADS)

Hamrick, Joseph L., II

Thin rectangular samples of Ti-6Al-4V were damaged by four methods to represent foreign object damage found in turbine engine blades: (1) impact with 2 mm. and 5 mm diameter glass spheres at 305 m/s, (2) impact with 2 mm and 4 mm diameter steel spheres at 305 m/s, (3) quasi-static displacement controlled indentation using steel chisels with 1 mm, 2 nun and 5 mm diameter tips and (4) shearing notches with a 2 mm. diameter chisel point under a quasi-static loading condition. Finite element analysis was used to study the relationship between the stress state created by the plastic damage and the fatigue strength. A new method of quantifying the amount of plastic damage from multiple methods was developed. The fatigue strength required for crack initiation at 10E7 cycles was found to be a function of the total depth from the edge of the undeformed specimen up to the end of the plastically deformed zone. For damage depths less than 1750 mum, the reduction in fatigue strength is proportional to the depth of total damage. For depths > 1750 mum, there appears to be a threshold value of fatigue strength.

Analysis of the Factors Affecting Surgical Success of Implants Placed in Iranian Warfare Victims

PubMed Central

Jafarian, Mohammad; Bayat, Mohammad; Pakravan, Amir-Hossein; Emadi, Naghmeh

2016-01-01

Objective The aim was to evaluate the survival time and success rates of dental implants in warfare victims and factors that affect implant success. Subjects and Methods This retrospective study involved 250 Iranian warfare victims who received dental implants from 2003 to 2013. Patients' demographic characteristics, as well as the brand, diameter, length, location and failure rate of the implants were retrieved from patients' dental records and radiographs. The associations between these data and the survival rate were analyzed. Statistical analysis was carried out with χ2 and log-rank tests. Results Overall, out of the 1,533 dental implants, 61 (4s%) failed. The maxillary canine area had the highest failure rate [9 of 132 implants (6.8s%)], while the mandibular incisor region had the least number of failures [3 of 147 implants (2.0s%)] and the longest survival time (approximately 3,182 days). Maxillary canine areas had the shortest survival (about 2,996 days). The longest survival time was observed in implants with 11 mm length (3,179.72 ± 30.139 days) and 3.75-4 mm diameter (3,131.161 ± 35.96 days), and the shortest survival was found in implants with 11.5 mm length (2,317.79 ± 18.71 days) and 6.5 mm diameter (2,241.45 ± 182.21 days). Moreover, implants with 10 mm length (10.7s%) and 5.5-6 mm diameter (22.2s%) had the highest failure rate; however, the least failure rate occurred when the implants were 11.5 mm in length (1.9s%) and 3-3.5 mm in diameter (3.1s%). Conclusions The brand, length and diameter of implants affected the survival time, failure rate and time to failure. The location of the implant was not statistically significant regarding the mentioned factors, although it has clinical significance. PMID:27322534

MRI surface-coil pair with strong inductive coupling.

PubMed

Mett, Richard R; Sidabras, Jason W; Hyde, James S

2016-12-01

A novel inductively coupled coil pair was used to obtain magnetic resonance phantom images. Rationale for using such a structure is described in R. R. Mett et al. [Rev. Sci. Instrum. 87, 084703 (2016)]. The original rationale was to increase the Q-value of a small diameter surface coil in order to achieve dominant loading by the sample. A significant improvement in the vector reception field (VRF) is also seen. The coil assembly consists of a 3-turn 10 mm tall meta-metallic self-resonant spiral (SRS) of inner diameter 10.4 mm and outer diameter 15.1 mm and a single-loop equalization coil of 25 mm diameter and 2 mm tall. The low-frequency parallel mode was used in which the rf currents on each coil produce magnetic fields that add constructively. The SRS coil assembly was fabricated and data were collected using a tissue-equivalent 30% polyacrylamide phantom. The large inductive coupling of the coils produces phase-coherency of the rf currents and magnetic fields. Finite-element simulations indicate that the VRF of the coil pair is about 4.4 times larger than for a single-loop coil of 15 mm diameter. The mutual coupling between coils influences the current ratio between the coils, which in turn influences the VRF and the signal-to-noise ratio (SNR). Data on a tissue-equivalent phantom at 9.4 T show a total SNR increase of 8.8 over the 15 mm loop averaged over a 25 mm depth and diameter. The experimental results are shown to be consistent with the magnetic resonance theory of the emf induced by spins in a coil, the theory of inductively coupled resonant circuits, and the superposition principle. The methods are general for magnetic resonance and other types of signal detection and can be used over a wide range of operating frequencies.

Angular and radial dependence of the energy response factor for LIF-TLD micro-rods in 125L permanent implant source.

PubMed

Mobit, Paul; Badragan, Iulian

2006-01-01

EGSnrc Monte Carlo simulations were used to calculate the angular and radial dependence of the energy response factor for LiF-thermoluminescence dosemeters (TLDs) irradiated with a commercially available (125)I permanent brachytherapy source. The LiF-TLDs were modelled as cylindrical micro-rods of length 6 mm and with diameters of 1 mm and 5 mm. The results show that for a LiF-TLD micro-rod of 1 mm diameter, the energy response relative to (60)Co gamma rays is 1.406 +/- 0.3% for a polar angle of 90 degrees and radial distance of 1.0 cm. When the diameter of the micro-rod is increased from 1 to 5 mm, the energy response decreases to 1.32 +/- 0.3% at the same point. The variation with position of the energy response factor is not >5% in a 6 cm x 6 cm x 6 cm calculation grid for the 5 mm diameter micro-rod. The results show that there is a change in the photon spectrum with angle and radial distance, which causes the variation of the energy response.

Directional Solidification and Convection in Small Diameter Crucibles

NASA Technical Reports Server (NTRS)

Chen, J.; Sung, P. K.; Tewari, S. N.; Poirier, D. R.; DeGroh, H. C., III

2003-01-01

Pb-2.2 wt% Sb alloy was directionally solidified in 1, 2, 3 and 7 mm diameter crucibles. Pb-Sb alloy presents a solutally unstable case. Under plane-front conditions, the resulting macrosegregation along the solidified length indicates that convection persists even in the 1 mm diameter crucible. Al-2 wt% Cu alloy was directionally solidified because this alloy was expected to be stable with respect to convection. Nevertheless, the resulting macrosegregation pattern and the microstructure in solidified examples indicated the presence of convection. Simulations performed for both alloys show that convection persists for crucibles as small as 0.6 mm of diameter. For the solutally stable alloy, Al-2 wt% Cu, the simulations indicate that the convection arises from a lateral temperature gradient.

The assessment of the stability of the corneal structure after LASIK correction of myopia by different optical zone diameters.

PubMed

Milivojević, Milorad; Petrović, Vladimir; Vukosavljević, Miroslav; Marjanović, Ivan; Resan, Mirko

2016-06-01

Enlargement of optical zone (OZ) diameter during laser in situ keratomileusis (LASIK) correction of myopia postoperatively improves the optical outcome, however, it also leads to the increased stroma tissue consumption--progressive corneal thinning. The aim of this investigation was to present the possibility of safe OZ enlargement without impairing the structural stability of the cornea, while obtaining an improved optical outcome with LASIK treatment of short-sightedness. Preoperative assessment of the cornea structure and prediction of the ablated stroma tissue consumption was conducted in 37 patients (74 eyes) treated for short-sightedness by means of the LASIK method. With the eyes that, according to their cornea structure, had the capacity for OZ diameter enlargement of 0.5 mm, LASIK treatment was performed within the wider OZ diameter of 7.0 mm compared to the standard 6.5 mm. The following two groups were formed, depending on the diameter of the utilized OZ: the group I (the eyes treated with the OZ 6.5 mm, n = 37) and the group II (the eyes treated with the OZ 7.0 mm, n = 37). No significant difference in the observed structural parameters of the cornea was detected between the groups of patients treated with different OZ diameters. The values of all the parameters were significantly bellow the threshold values for the development of postoperative ectasia. Diameter enlargement of the treated OZ, if there is a preoperative cornea capacity for such enlargement, will not impair the postoperative stability of the cornea structure, and will significantly improve the optical outcome.

Footprint Reduction for the Acoustic Electric Feedthrough Technique

DTIC Science & Technology

2010-03-01

input current measured using a 1 Ω sense resistor . Modulation depth of the peak- to-peak input current was 2Δ ~ 20...behaviour of an AEF arrangement formed using piezo -ceramic disks with diameter 38 mm and thickness 2 mm, across an aluminium plate with thickness 1.6 to 5...the 38 mm diameter piezo -ceramic disks. In an attempt to resolve this matter, the DSTO has examined an AEF system formed using disks with 10 mm

A new high-resolution PET scanner dedicated to brain research

NASA Astrophysics Data System (ADS)

Watanabe, M.; Shimizu, K.; Omura, T.; Takahashi, M.; Kosugi, T.; Yoshikawa, E.; Sato, N.; Okada, H.; Yamashita, T.

2002-06-01

A high-resolution positron emission tomography (PET) scanner dedicated to brain studies has been developed and its physical performance was evaluated. The block detector consists of a new compact position-sensitive photomultiplier tube (PS-PMT, Hamamatsu R7600-C12) and an 8/spl times/4 bismuth germanate (BGO) array. The size of each crystal is 2.8 mm/spl times/6.55 mm/spl times/30 mm. The system has a total of 11 520 crystals arranged in 24 detector rings 508 mm in diameter (480 per ring). The field of view (FOV) is 330 mm in diameter/spl times/163 mm, which is sufficient to measure the entire human brain. The diameter of the scanner's opening is equal to the transaxial FOV (330 mm). The system can be operated in three-dimensional (3-D) data acquisition mode, when the slice septa are retracted. The mechanical motions of the gantry and bed are specially designed to measure the patient in various postures; lying, sitting, and even standing postures. The spatial resolution of 2.9 mm in both the transaxial and axial directions is obtained at the center of the FOV. The total system sensitivity is 6.4 kc/s/kBq/ml in two-dimensional (2-D) mode, with a 20-cm-diameter cylindrical phantom. The imaging capabilities of the scanner were studied with the Hoffman brain phantom and with a normal volunteer.

Effect of holed reflector on acoustic radiation force in noncontact ultrasonic dispensing of small droplets

NASA Astrophysics Data System (ADS)

Tanaka, Hiroki; Wada, Yuji; Mizuno, Yosuke; Nakamura, Kentaro

2016-06-01

We investigated the fundamental aspects of droplet dispensing, which is an important procedure in the noncontact ultrasonic manipulation of droplets in air. A holed reflector was used to dispense a droplet from a 27.4 kHz standing-wave acoustic field to a well. First, the relationship between the hole diameter of the reflector and the acoustic radiation force acting on a levitated droplet was clarified by calculating the acoustic impedance of the point just above the hole. When the hole diameter was half of (or equal to) the acoustic wavelength λ, the acoustic radiation force was ∼80% (or 50%) of that without a hole. The maximal diameters of droplets levitated above the holes through flat and half-cylindrical reflectors were then experimentally investigated. For instance, with the half-cylindrical reflector, the maximal diameter was 5.0 mm for a hole diameter of 6.0 mm, and droplets were levitatable up to a hole diameter of 12 mm (∼λ).

Progress on the Use of Internal Fins as Barriers to Reduce Magnetization on High Current Density Mono Element Internal Tin Conductors (MEIT)

NASA Astrophysics Data System (ADS)

Zeitlin, Bruce A.; Gregory, Eric; Pyon, Taeyoung; Scanlan, R. M.; Polyanskii, Anatolii A.; Lee, Peter J.

2004-06-01

A number of configurations of a mono element internal tin conductor (MEIT) were fabricated to explore the effect of internal fins on the effective filament size (Deff) and its effect on wire processing. A current density of 2.85 × 109 A/m2 (12 T) was achieved in a high tin, high Nb conductor. Wire lengths as long as 15.8 km at 0.254 mm diameter with breaks averaging 3 per unit length were achieved. Magnetization measurements and Magneto-Optical (MO) images were taken of the finned and non-fin conductor which indicated the fins appeared to be effective. The Deff achieved in the fin conductor was 80 μm compared with an equivalent conductor without a fin of 165 μm.

Maximizing coupling strength of magnetically anchored surgical instruments: how thick can we go?

PubMed

Best, Sara L; Bergs, Richard; Gedeon, Makram; Paramo, Juan; Fernandez, Raul; Cadeddu, Jeffrey A; Scott, Daniel J

2011-01-01

The Magnetic Anchoring and Guidance System (MAGS) includes an external magnet that controls intra-abdominal surgical instruments via magnetic attraction forces. We have performed NOTES (Natural Orifice Transluminal Endoscopic Surgery) and LESS (Laparoendoscopic Single Site) procedures using MAGS instruments in porcine models with up to 2.5-cm-thick abdominal walls, but this distance may not be sufficient in some humans. The purpose of this study was to determine the maximal abdominal wall thickness for which the current MAGS platform is suitable. Successive iterations of prototype instruments were developed; those evaluated in this study include external (134-583 g, 38-61 mm diameter) and internal (8-39 g, 10-22 mm diameter) components using various grades, diameters, thicknesses, and stacking/shielding/focusing configurations of permanent Neodymium-iron-boron (NdFeB) magnets. Nine configurations were tested for coupling strength across distances of 0.1-10 cm. The force-distance tests across an air medium were conducted at 0.5-mm increments using a robotic arm fitted with a force sensor. A minimum theoretical instrument drop-off (decoupling) threshold was defined as the separation distance at which force decreased below the weight of the heaviest internal component (39 g). Magnetic attraction forces decreased exponentially over distance. For the nine configurations tested, the average forces were 3,334 ± 1,239 gf at 0.1 cm, 158 ± 98 gf at 2.5 cm, and 8.7 ± 12 gf at 5 cm; the drop-off threshold was 3.64 ± 0.8 cm. The larger stacking configurations and magnets yielded up to a 592% increase in attraction force at 2.5 cm and extended the drop-off threshold distance by up to 107% over single-stack anchors. For the strongest configuration, coupling force ranged from 5,337 gf at 0.1 cm to 0 gf at 6.95 cm and yielded a drop-off threshold distance of 4.78 cm. This study suggests that the strongest configuration of currently available MAGS instruments is suitable for clinically relevant abdominal wall thicknesses. Further platform development and optimization are warranted.

24th International Symposium on Ballistics

DTIC Science & Technology

2008-09-26

production Samples dimensions were 0.3x0.05 m. Test set up Gas gun 5.5 mm diameter steel spheres and sabot Velocity measuring  systems High speed rate...Oilwell perforators – small caliber shaped charges – create the pathway for oil or gas to flow from the reservoir rock into the wellbore  Deep, clean ...overburden, tectonic) – Pore fluid pressure – Pore fluid type ( liquid vs. gas ) Background  Geomechanics considerations: – In-situ stresses (“total

[Difficult reintubation during a Fantoni's tracheostomy resolved using a laryngeal mask].

PubMed

Ould-Ahmed, M; Mas, B; Paris, A; Caroff, P; Segalen, F

2001-04-01

We report the failure of a reintubation under direct laryngoscopy, during a percutaneous tracheostomy by Fantoni method. After the accidental per-procedural extubation and in front of an unpredicted difficult conventional endotracheal intubation, a laryngeal mask was used as an airway intubator conduit for the blind passage of the set's ventilation tube. This ventilation tube is a 40 cm long, 4 mm internal diameter special catheter with low pressure cuff, included into the TLT kit. The end of the procedure was uneventful.

External Versus Internal Pancreatic Duct Drainage for the Early Efficacy After Pancreaticoduodenectomy: A Retrospectively Comparative Study.

PubMed

Wang, Gang; Li, Le; Ma, Yuan; Qu, Feng-Zhi; Zhu, Hong; Lv, Jia-Chen; Jia, Yue-Hui; Wu, Lin-Feng; Sun, Bei

2016-08-01

To compare the early efficacy of external versus internal pancreatic duct drainage after pancreaticoduodenectomy (PD), providing clinical evidence for selecting the optimal approach to pancreatic duct drainage. The clinical data of 395 consecutive patients undergoing PD from 2006 to 2013 were analyzed retrospectively. All the patients were divided into external and internal drainage group. Intraoperative blood loss, surgery duration, postoperative hospitalization duration, mortality rate, PF, and other complications were compared between the two groups. The perioperative relative risk factors that might induce PF were analyzed. External drainage significantly reduced the incidences of post-PD PF, delayed gastric emptying, abdominal infection, bowel obstruction, overall complications, and shortened the healing time of PF (p < .05). The univariate analysis showed that the pancreatic duct drainage method, body mass index (BMI), preoperative serum bilirubin level, perioperative blood transfusion, pancreaticojejunostomy approach, pancreatic texture, pancreatic duct diameter, and primary disease differed markedly between the two groups (p < .05). A multivariate analysis revealed that BMI ≥ 25 kg/m(2), internal pancreatic duct drainage, pancreatic duct diameter <3 mm, soft pancreatic texture, and ampullary disease were independent risk factors for PF. External pancreatic duct drainage can effectively reduce the morbidity of PF and overall complications after PD.

A continuously variable beam-diameter, high-fluence, Q-switched Nd:YAG laser for tattoo removal: comparison of the maximum beam diameter to a standard 4-mm-diameter treatment beam.

PubMed

Bernstein, Eric F; Civiok, Jennifer M

2013-12-01

Laser beam diameter affects the depth of laser penetration. Q-switched lasers tend to have smaller maximum spot sizes than other dermatologic lasers, making beam diameter a potentially more significant factor in treatment outcomes. To compare the clinical effect of using the maximum-size treatment beam available for each delivered fluence during laser tattoo removal to a standard 4-mm-diameter treatment beam. Thirteen tattoos were treated in 12 subjects using a Q-switched Nd:YAG laser equipped with a treatment beam diameter that was adjustable in 1 mm increments and a setting that would enable the maximally achievable diameter ("MAX-ON" setting) with any fluence. Tattoos were randomly bisected and treated on one side with the MAX-ON setting and on the contralateral side with a standard 4-mm-diameter spot ("MAX-OFF" setting). Photographs were taken 8 weeks following each treatment and each half-tattoo was evaluated for clearance on a 10-point scale by physicians blinded to the treatment conditions. Tattoo clearance was greater on the side treated with the MAX-ON setting in a statistically significant manner following the 1st through 4th treatments, with the MAX-OFF treatment site approaching the clearance of the MAX-ON treatment site after the 5th and 6th treatments. This high-energy, Q-switched Nd:YAG laser with a continuously variable spot-size safely and effectively removes tattoos, with greater removal when using a larger spot-size. © 2013 Wiley Periodicals, Inc.

Risk factors for neurological worsening and symptomatic watershed infarction in internal carotid artery aneurysm treated by extracranial-intracranial bypass using radial artery graft.

PubMed

Matsukawa, Hidetoshi; Tanikawa, Rokuya; Kamiyama, Hiroyasu; Tsuboi, Toshiyuki; Noda, Kosumo; Ota, Nakao; Miyata, Shiro; Oda, Jumpei; Takeda, Rihee; Tokuda, Sadahisa; Kamada, Kyousuke

2016-08-01

OBJECT The revascularization technique, including bypass created using the external carotid artery (ECA), radial artery (RA), and M2 portion of middle cerebral artery (MCA), has remained indispensable for treatment of complex aneurysms. To date, it remains unknown whether diameters of the RA, superficial temporal artery (STA), and C2 portion of the internal carotid artery (ICA) and intraoperative MCA blood pressure have influences on the outcome and the symptomatic watershed infarction (WI). The aim of the present study was to evaluate the factors for the symptomatic WI and neurological worsening in patients treated by ECA-RA-M2 bypass for complex ICA aneurysm with therapeutic ICA occlusion. METHODS The authors measured the sizes of vessels (RA, C2, M2, and STA) and intraoperative MCA blood pressure (initial, after ICA occlusion, and after releasing the RA graft bypass) in 37 patients. Symptomatic WI was defined as presence of the following: postoperative new neurological deficits, WI on postoperative diffusion-weighted imaging, and ipsilateral cerebral blood flow reduction on SPECT. Neurological worsening was defined as the increase in 1 or more modified Rankin Scale scores. First, the authors performed receiver operating characteristic curve analysis for continuous variables and the binary end point of the symptomatic WI. The clinical, radiological, and physiological characteristics of patients with and without the symptomatic WI were compared using the log-rank test. Then, the authors compared the variables between patients with and without neurological worsening at discharge and at the 12-month follow-up examination or last hospital visit. RESULTS Symptomatic WI was observed in 2 (5.4%) patients. The mean MCA pressure after releasing the RA graft (< 55 mm Hg; p = 0.017), mean (MCA pressure after releasing the RA graft)/(initial MCA pressure) (< 0.70 mm Hg; p = 0.032), and mean cross-sectional area ratio ([RA/C2 diameter](2) < 0.40 mm [p < 0.0001] and [STA/C2 diameter](2) < 0.044 mm [p < 0.0001]) were related to the symptomatic WI. All preoperatively independent patients remained independent (modified Rankin Scale score < 3). After adjusting for age and sex, left operative side (p = 0.0090 and 0.038) and perforating artery ischemia (p = 0.0050 and 0.022) were related to neurological worsening at discharge (11 [29%] patients) and at the 12-month follow-up or last hospital visit (8 [22%] patients). CONCLUSIONS Results of the present study showed that the vessel diameter and intraoperative MCA pressure had impacts on the symptomatic WI and that operative side and perforating artery ischemia were related to neurological worsening in patients with complex ICA aneurysms treated by ECA-RA-M2 bypass.

Determination of ion mobility in EHD flow zone of plasma generator

NASA Astrophysics Data System (ADS)

Sumariyah, Kusminarto, Hermanto, Arief; Nuswantoro, Pekik

2015-12-01

Determination has been carried out for ion mobility in EHD flow zone generated using a pin-concentric multiple ring electrodes and a pin-single ring electrode used as a comparator. The pin needle was made from stainless steel with a tip diameter of 0.18 mm. The concentris multiple ring electrode in form three/two concentric ring electrodes which made of metal material connected to each other. Each ring of three concentric ring electrode has a diameter of 24 mm, 16 mm and 8 mm. And each ring of two concentric ring electrode has a diameter of 24 mm and 16 mm. Single ring electrode has a diameter24 mm. The all ring has same of width and thickness were 2 mm and 3 mm. EHD was generated by using a DC high voltage of 10 kV. Pin functional as an active electrode of corona discharge while the all ring electrodes acted as ions collector and passive electrodes. The experimental results show that the ion current is proportional to V2 according to calculations by Chouelo for hyperbolic-field approach. Ion mobility obtained from the quadratic polynomial fitting of experimental data were current and voltage as well as Choelo formulation. The results showed that the mobility of ions in the EHD flow zones utilizing pin-consentric multiple ring electrode larger than utilizing pin-single ring electrode. Pin-three Consentic ring electrode has the largest of ion mobility

Pyrolysis of Large Black Liquor Droplets

NASA Technical Reports Server (NTRS)

Bartkus, Tadas P.; Dietrich, Daniel L.; T'ien, James S.; Wessel, Richard A.

2007-01-01

This paper presents the results of experiments involving the pyrolysis of large black liquor droplets in the NASA KC-135 reduced gravity aircraft. The reduced gravity environment facilitated the study of droplets up to 9 mm in diameter extending the results of previous studies to droplet sizes that are similar to those encountered in recovery boilers. Single black liquor droplets were rapidly inserted into a 923 K oven. The primary independent variables were the initial droplet diameter (0.5 mm to 9 mm), the black liquor solids content (66.12% - 72.9% by mass), and the ambient oxygen mole fraction (0.0 - 0.21). Video records of the experiments provided size and shape of the droplets as a function of time. The results show that the particle diameter at the end of the drying stage (D(sub DRY)) increases linearly with the initial particle diameter (D(sub O)). The results further show that the ratio of the maximum swollen diameter (D(sub MAX)) to D(sub O) decreases with increasing D(sub O) for droplets with D(sub O) less than 4 mm. This ratio was independent of D(sub O) for droplets with D(sub O) greater than 4 mm. The particle is most spherical at the end of drying, and least spherical at maximum swollen size, regardless of initial sphericity and droplet size.

Pyrolysis of Large Black Liquor Droplets

NASA Technical Reports Server (NTRS)

Bartkus, Tadas P.; T'ien, James S.; Dietrich, Daniel L.; Wessel, Richard A.

2007-01-01

This paper presents the results of experiments involving the pyrolysis of large black liquor droplets in the NASA KC-135 reduced gravity aircraft. The reduced gravity environment facilitated the study of droplets up to 9 mm in diameter extending the results of previous studies to droplet sizes that are similar to those encountered in recovery boilers. Single black liquor droplets were rapidly inserted into a 923 K oven. The primary independent variables were the initial droplet diameter (0.5 mm to 9 mm), the black liquor solids content (66.12% - 72.9% by mass), and the ambient oxygen mole fraction (0.0 - 0.21). Video records of the experiments provided size and shape of the droplets as a function of time. The results show that the particle diameter at the end of the drying stage (D(sub DRY) ) increases linearly with the initial particle diameter (D(sub O)). The results further show that the ratio of the maximum swollen diameter (D(sub MAX)) to D(sub O) decreases with increasing D(sub O) for droplets with D(sub O) less than 4 mm. This ratio was independent of D(sub O) for droplets with D(sub O) greater than 4 mm. The particle is most spherical at the end of drying, and least spherical at maximum swollen size, regardless of initial sphericity and droplet size.

Esophageal varices on computed tomography and subsequent variceal hemorrhage.

PubMed

Somsouk, Ma; To'o, Katherine; Ali, Mujtaba; Vittinghoff, Eric; Yeh, Benjamin M; Yee, Judy; Monto, Alex; Inadomi, John M; Aslam, Rizwan

2014-04-01

Endoscopy is recommended to screen for esophageal varices in patients with cirrhosis. The objective of this study was to identify features on abdominal CT imaging associated variceal hemorrhage (VH). A case-control study was performed among patients with cirrhosis who had a CT scan. Consecutive patients who experienced VH were included as cases, and patients without VH served as controls. Two radiologists recorded the maximal esophageal varix diameter in addition to other measures of portal hypertension at CT. The most powerful CT parameter associated with VH was the esophageal varix diameter (5.8 vs. 2.7 mm, p < 0.001; adjusted OR 1.84 per mm, p = 0.009). 63% of individuals with VH had a maximal varix diameter ≥5 mm compared to 7.5% of cirrhotic patients without VH (p < 0.001). In contrast, the proportion of individuals whose largest varix was <3 mm was 7.4% among VH cases compared to 54.7% among controls (p = 0.001). The varix diameter powerfully discriminated those with and without VH (C-statistic 0.84). A large esophageal varix diameter is strongly associated with subsequent VH. A threshold of <3 and ≥5 mm appears to identify patients with cirrhosis at low and high risk for hemorrhage.

Esophageal varices on computed tomography and subsequent variceal hemorrhage

PubMed Central

Somsouk, Ma; To'o, Katherine; Ali, Mujtaba; Vittinghoff, Eric; Yeh, Benjamin M.; Yee, Judy; Monto, Alex; Inadomi, John M.; Aslam, Rizwan

2014-01-01

Purpose Endoscopy is recommended to screen for esophageal varices in patients with cirrhosis. The objective of this study was to identify features on abdominal CT imaging associated variceal hemorrhage (VH). Methods A case–control study was performed among patients with cirrhosis who had a CT scan. Consecutive patients who experienced VH were included as cases, and patients without VH served as controls. Two radiologists recorded the maximal esophageal varix diameter in addition to other measures of portal hypertension at CT. Results The most powerful CT parameter associated with VH was the esophageal varix diameter (5.8 vs. 2.7 mm, p < 0.001; adjusted OR 1.84 per mm, p = 0.009). 63% of individuals with VH had a maximal varix diameter ≥5 mm compared to 7.5% of cirrhotic patients without VH (p < 0.001). In contrast, the proportion of individuals whose largest varix was <3 mm was 7.4% among VH cases compared to 54.7% among controls (p = 0.001). The varix diameter powerfully discriminated those with and without VH (C-statistic 0.84). Conclusions A large esophageal varix diameter is strongly associated with subsequent VH. A threshold of <3 and ≥5 mm appears to identify patients with cirrhosis at low and high risk for hemorrhage. PMID:24366107

Numerical investigation of combustion phenomena in pulse detonation engine with different fuels

NASA Astrophysics Data System (ADS)

Alam, Noor; Sharma, K. K.; Pandey, K. M.

2018-05-01

The effects of different fuel-air mixture on the cyclic operation of pulse detonation engine (PDE) are numerically investigated. The present simulation is to be consider 1200 mm long straight tube combustor channel and 60 mm internal diameter, and filled with stoichiometric ethane-air and ethylene-air (C2H6-air & C2H4) fuel mixture at atmospheric pressure and temperature of 0.1 MPa and 300 K respectively. The obstacles of blockage ratio (BR) 0.5 and having 60 mm spacing among them are allocated inside the combustor tube. There are realizable k-ɛ turbulence model used to analyze characteristic of combustion flame. The objective of present simulation is to analyze the variation in combustion mechanism for two different fuels with one-step reduced chemical reaction model. The obstacles were creating perturbation inside the PDE tube. Therefore, flame surface area increases and reduces deflagration-to-detonation transition (DDT) run-up length.

Corneal Power Distribution and Functional Optical Zone Following Small Incision Lenticule Extraction for Myopia.

PubMed

Qian, Yishan; Huang, Jia; Zhou, Xingtao; Hanna, Rewais Benjamin

2015-08-01

To evaluate corneal power distribution using the ray tracing method (corneal power) in eyes undergoing small incision lenticule extraction (SMILE) surgery and compare the functional optical zone with two lenticular sizes. This retrospective study evaluated 128 patients who underwent SMILE for the correction of myopia and astigmatism with a lenticular diameter of 6.5 mm (the 6.5-mm group) and 6.2 mm (the 6.2-mm group). The data include refraction, correction, and corneal power obtained via a Scheimpflug camera from the pupil center to 8 mm. The surgically induced changes in corneal power (Δcorneal power) were compared to correction and Δrefraction. The functional optical zone was defined as the largest ring diameter when the difference between the ring power and the pupil center power was 1.50 diopters or less. The functional optical zone was compared between two lenticular diameter groups. Corneal power distribution was measured by the ray tracing method. In the 6.5-mm group (n=100), Δcorneal power at 5 mm showed the smallest difference from Δrefraction and Δcorneal power at 0 mm exhibited the smallest difference from correction. In the 6.2-mm group (n=28), Δcorneal power at 2 mm displayed the lowest dissimilarity from Δrefraction and Δcorneal power at 4 mm demonstrated the lowest dissimilarity from correction. There was no significant difference between the mean postoperative functional optical zones in either group when their spherical equivalents were matched. Total corneal refactive power can be used in the evaluation of surgically induced changes following SMILE. A lenticular diameter of 6.2 mm should be recommended for patients with high myopia because there is no functional difference in the optical zone. Copyright 2015, SLACK Incorporated.

Independent Suture Tape Reinforcement of Small and Standard Diameter Grafts for Anterior Cruciate Ligament Reconstruction: A Biomechanical Full Construct Model.

PubMed

Bachmaier, Samuel; Smith, Patrick A; Bley, Jordan; Wijdicks, Coen A

2018-02-01

To compare the dynamic elongation, stiffness behavior, and ultimate failure load of standard with small diameter soft tissue grafts for anterior cruciate ligament (ACL) reconstruction with and without high-strength suture tape reinforcement. Both a tripled "small" diameter and a "standard" quadrupled tendon graft with and without suture tape reinforcement were tested using suspensory fixation (n = 8 each group). The suture tape was passed through the suspensory fixation button on the femur and tibia to ensure independent (safety belt) fixation from the graft in vitro. The testing of the constructs included position-controlled cyclic loading, force-controlled cyclic loading at 250 N and 400 N as well as pull to failure (50 mm/min). Reinforcement of a small diameter graft significantly reduced dynamic elongation of 38% (1.46 ± 0.28 mm vs 2.34 ± 0.44 mm, P < .001) and 50% (2.55 ± 0.44 mm vs 5.06 ± 0.67 mm, P < .001) after the 250 N and 400 N load protocol, respectively. Reinforcement of a standard diameter tendon graft decreased dynamic elongation of 15% (1.59 ± 0.34 mm vs 1.86 ± 0.17 mm, P = .066) and 26% (2.62 ± 0.44 mm vs 3.55 ± 0.44 mm, P < .001). No significant difference was found between both reinforced models. The ultimate failure loads of small and standard diameter reinforced grafts were 1592 ± 105 N and 1585 ± 265 N, resulting in a 64% (P < .001) and 40% (P < .001) increase compared with their respective controls. Independent suture tape reinforcement of soft tissue grafts for ACL reconstruction leads to significantly reduced elongation and higher ultimate failure load according to in vivo native ACL function data without stress-shielding the soft tissue graft. If in vitro results are translational to human knees in vivo, the suture tape reinforcement technique for ACL reconstruction may decrease the risk of graft tears, particularly in the case of small diameter soft tissue grafts. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Left Atrial Size and Left Ventricular End-Systolic Dimension Predict the Progression of Paroxysmal Atrial Fibrillation After Catheter Ablation.

PubMed

Liao, Ying-Chieh; Liao, Jo-Nan; Lo, Li-Wei; Lin, Yenn-Jiang; Chang, Shih-Lin; Hu, Yu-Feng; Chao, Tze-Fan; Chung, Fa-Po; Tuan, Ta-Chuan; Te, Abigail Louise D; Walia, Rohit; Yamada, Shinya; Lin, Chung-Hsing; Lin, Chin-Yu; Chang, Yao-Ting; Allamsetty, Suresh; Yu, Wen-Chung; Huang, Jing-Long; Wu, Tsu-Juey; Chen, Shih-Ann

2017-01-01

Although rare, some paroxysmal atrial fibrillations (AF) still progress despite radiofrequency (RF) ablation. In the study, we evaluated the long-term efficacy of RF ablation and the predictors of AF progression. A total of 589 paroxysmal AF patients (404 men and 185 women; aged 54 ± 12 years) who received 3-dimensional mapping and ablation were enrolled. Their clinical parameters and electrophysiological characteristics were collected. They were divided into Group 1 (N = 13, with AF progression) and Group 2 (N = 576, no AF progression). AF progression was defined as recurrence of persistent AF. Group 1 patients had larger left atrial (LA) diameter, larger left ventricle (LV) end-systolic and end-diastolic diameters, poorer LV systolic function, and more amiodarone use at baseline. After 1.2 ± 0.5 procedures, 123 (21%) patients experienced recurrence during 56 ± 29 months' follow-up. In the multivariate analysis, LA diameter (P = 0.018, HR = 1.12, 95% CI = 1.02-1.24) and LV end-systolic diameter (P = 0.005, HR = 1.10, 95% CI = 1.03-1.17) independently predicted AF progression. LA diameter >43 mm and LV end-systolic diameter >31 mm were the best cut-off values for predicting AF progression by ROC analysis. AF progression rate achieved 19% if they had both larger LA diameter (>43 mm) and LV end-systolic diameter (>31 mm). RF ablation prevents the progression of paroxysmal AF effectively, except in patients with increased LA diameter and LV end-systolic diameter on echocardiogram, suggesting more aggressive rhythm control therapies should be considered in these patients. © 2016 Wiley Periodicals, Inc.

Validating automated kidney stone volumetry in computed tomography and mathematical correlation with estimated stone volume based on diameter.

PubMed

Wilhelm, Konrad; Miernik, Arkadiusz; Hein, Simon; Schlager, Daniel; Adams, Fabian; Benndorf, Matthias; Fritz, Benjamin; Langer, Mathias; Hesse, Albrecht; Schoenthaler, Martin; Neubauer, Jakob

2018-06-02

To validate AutoMated UroLithiasis Evaluation Tool (AMULET) software for kidney stone volumetry and compare its performance to standard clinical practice. Maximum diameter and volume of 96 urinary stones were measured as reference standard by three independent urologists. The same stones were positioned in an anthropomorphic phantom and CT scans acquired in standard settings. Three independent radiologists blinded to the reference values took manual measurements of the maximum diameter and automatic measurements of maximum diameter and volume. An "expected volume" was calculated based on manual diameter measurements using the formula: V=4/3 πr³. 96 stones were analyzed in the study. We had initially aimed to assess 100. Nine were replaced during data acquisition due of crumbling and 4 had to be excluded because the automated measurement did not work. Mean reference maximum diameter was 13.3 mm (5.2-32.1 mm). Correlation coefficients among all measured outcomes were compared. The correlation between the manual and automatic diameter measurements to the reference was 0.98 and 0.91, respectively (p<0.001). Mean reference volume was 1200 mm³ (10-9000 mm³). The correlation between the "expected volume" and automatically measured volume to the reference was 0.95 and 0.99, respectively (p<0.001). Patients' kidney stone burden is usually assessed according to maximum diameter. However, as most stones are not spherical, this entails a potential bias. Automated stone volumetry is possible and significantly more accurate than diameter-based volumetric calculations. To avoid bias in clinical trials, size should be measured as volume. However, automated diameter measurements are not as accurate as manual measurements.

Use of 5-mm-diameter implants: Periotest values related to a clinical and radiographic evaluation.

PubMed

Aparicio, C; Orozco, P

1998-12-01

A modified design of the original Brånemark implant consisting of a cp. Titanium 5.0-mm-diameter self-tapping implant threaded up to the marginal platform has been proposed for specific indications. From February 1992 to November 1995, a total of 185 machined screw implants (Nobel Biocare, Gothenburg, Sweden) were installed in 45 patients to withstand 58 prostheses. Of these, 91 were 3.75-mm diameter and 94 were 5.0-mm wide. Most of the implants were placed in type B and C bone quantity and type 2 and 3 bone quality. A retrospective evaluation with regard to indications, marginal bone remodelling, Periotest values (PTv) and survival rate is presented. PTv and radiographic measurements were made at abutment connection and repeated 3, 6 and 12 months later and thereafter every year. The follow-up ranged from 16 to 55 months (mean 32.9 months) post-loading. Three patients with 8 5.0-mm implants dropped-out of the study at different stages. Out of the wide implants, 1 was expelled during the healing period; 3 were found mobile at the abutment connection; 1 lost its osseointegration suddenly after 2 years of function; 4 belonging to 1 patient did not meet the success criteria due to continuous marginal bone loss. The cumulative success rate of 5.0-mm implants (CSR) after 1 year of function was 97.2% for upper jaws and 88.4% in mandibles, whereas the CSR in maxilla after 48 months was 97.2% and 83.4% in mandibles. The obtained PTv from 5.0-mm-wide fixtures in maxilla and mandibles were respectively 1.1 and 0.6 units lower than those obtained PTv for 3.75-mm-diameter implants in the same patients. The hypothesis that there are differences in the damping capacity of the bone surrounding a 5.0-mm-wide implant compared to the 3.75-mm-diameter implant is supported by the PTv results.

Effect of varying fixture width on stress and strain distribution associated with an implant stack system.

PubMed

Mahon, J M; Norling, B K; Phoenix, R D

2000-01-01

The purpose of this investigation was to evaluate the dissipation of a force applied to an assembled stack of implant components. The stack consisted of a 10-mm threaded implant, a screw-retained abutment and a screw-retained gold crown. The dissipation of force was analyzed in relation to varying the implant diameter with and without a concomitant change in abutment diameter. Two experimental groups were evaluated. The first group consisted of 25 titanium screw-form implants (Implant Innovations, Inc.). These implants measured 10 mm in length and 3.25 mm, 3.75 mm, 4.0 mm, 5.0 mm, and 6.0 mm in diameter. The second group included 15 titanium screw-form implants (Nobel Biocare, Inc.) measuring 10 mm in length and 3.75 mm, 4.0 mm, and 5.0 mm in diameter. All implants were embedded in standardized photoelastic resin blocks. Points of interest were marked on each block using standardized templates to ensure consistency. Implants were restored using system-specific conical abutments and standardized single-unit restorations. A strain gauge was affixed to each abutment, and an eccentric load of 176 N was applied to the restoration. Periimplant stresses were measured using photoelastic analysis. Abutment strain was determined using an electronic strain indicator. Data were collated and compared using ANOVA and the Duncan multiple range statistical tests. When stress was analyzed at points on the resin-implant interface or a fixed distance from the interface, stress tended to decrease from the 5-mm-wide implant to the 6-mm-wide implant. Stress in relation to the 3.25-mm, 3.75-mm, and 4.0-mm implant was not as well defined, indicating the possibility that some deformation of implants was occurring. Increased abutment width resulted in decreased abutment strain. Therefore, using a wider abutment may be helpful in preventing preload reduction in clinical applications. This may reduce the incidence of loosening and fracture of abutment and restoration screws.

Comparison of epidermal/dermal damage between the long-pulsed 1064 nm Nd:YAG and 755 nm alexandrite lasers under relatively high fluence conditions: quantitative and histological assessments.

PubMed

Lee, Ju Hwan; Park, So Ra; Jo, Jeong Ho; Park, Sung Yun; Seo, Young Kwon; Kim, Sung Min

2014-07-01

The purpose of this study was to compare degrees of epidermal/dermal tissue damage quantitatively and histologically after laser irradiation, to find ideal treatment conditions with relatively high fluence for skin rejuvenation. A number of recent studies have evaluated the clinical efficacy and safety of therapeutic lasers under relatively low fluence conditions. We transmitted the long-pulsed 1064 nm Nd:YAG and 755 nm Alexandrite lasers into pig skin according to different fluences and spot diameters, and estimated epidermal/dermal temperatures. Pig skin specimens were stained with hematoxylin and eosin for histological assessments. The fluence conditions comprised 26, 30, and 36 J/cm2, and the spot diameter conditions were 5, 8, and 10 mm. Pulse duration was 30 ms for all experiments. Both lasers produced reliable thermal damage on the dermis without any serious epidermal injuries, under relatively high fluence conditions. The 1064 nm laser provided more active fibrous formations than the 755 nm laser, while higher risks for tissue damages simultaneously occurred. The ideal treatment conditions for skin rejuvenation were 8 mm diameter with 30 J/cm2 and 10 mm diameter with 26 J/cm2 for the 1064 nm laser, and 8 mm diameter with 36 J/cm2 and 10 mm diameter with 26 J/cm2 for the 755 nm laser.

Follicles and gonadotropins during waves 2 and 3 in three-wave interovulatory intervals in Bos taurus heifers.

PubMed

Ginther, O J; Siddiqui, M A R; Araujo, E R; Dangudubiyyam, S V

2017-12-01

Observations were made on follicle dynamics and gonadotropin concentrations in anovulatory wave 2 and ovulatory wave 3 in three-wave interovulatory intervals (n = 15). Hypotheses were not used owing to inadequate availability of rationale. The future dominant follicles for waves 2 and 3 were designated DF2 and DF3 and the largest future subordinate follicles as SF2 and SF3, respectively. The day of expected diameter deviation (day 0) was defined as the day that DF2 or DF3 was closest to 8.5 mm. The first day that DF2 became smaller (P < 0.05) than DF3 was day 2 (10.7 ± 0.2 mm vs 11.8 ± 0.3 mm). The FSH surges 2 and 3 that stimulated waves 2 and 3 were similar at peak concentration, but the postsurge nadir of surge 2 occurred 1 day earlier than for surge 3. An LH increase was not temporally associated with deviation in wave 2, but an increase (P < 0.05) in LH in wave 3 began on day -1. Diameter of SF2 (6.5 ± 0.2 mm) on day 0 was less (P < 0.005) than for SF3 (7.2 ± 0.2 mm). Mean diameter of subordinate follicles in wave 2 did not differ among days. Diameter of subordinate follicles that attained ≥6 mm in wave 3 was greater (interaction, P < 0.02) by day 3 when in the right ovary (RO, 7.4 ± 0.2 mm) than when in the left ovary (LO, 5.6 ± 0.2 mm). The frequency of a conventional classification of deviation (future SF greater than 7.0 mm on day 0) was less (P < 0.001) for wave 2 (1 of 15 waves) than for wave 3 (8 of 15 waves). Novel observations involving DF2 and DF3 were (1) before deviation, diameter of DF2 vs DF3 and an incline in FSH surge 2 vs surge 3 were similar and (2) after deviation, smaller diameter of DF2 vs DF3 by day 2 was associated with an earlier cessation (nadir) in FSH surge 2 vs surge 3 and an absence of an LH increase during deviation. Novel observations involving subordinate follicles ≥6 mm were (1) before deviation, diameters were similar between waves 2 and 3 in association with the similar incline in FSH surges 2 vs 3 and (2) after deviation, a greater diameter increase of subordinates occurred in RO than in LO for wave 3, but an increase did not occur for either ovary in wave 2. The characteristics of diameter deviation were profoundly different between waves 2 and 3 owing to a smaller SF2 than SF3 at deviation but similar diameter of DF2 and DF3. Copyright © 2017 Elsevier Inc. All rights reserved.

Thermal Management Investigations in Ceramic Thin Disk Lasers

DTIC Science & Technology

2011-01-14

techniques. 10-14mm diameter 0.2mm thick disks are mounted on silicon carbide ( SiC ), sapphire, and diamond submounts. From a larger platform, more than 6kW...along with various cooling techniques. 10-14mm diameter O.2mm thick disks are mounted on silicon carbide ( SiC ), sapphire, and diamond submounts. From a...assemblies are either attached to heat sinks or directly to the Cu W cooling mount, see Fig. I (c) & (d). The heat sinks tested are SiC , sapphire, and

An experimental study of the reflection from spherical and flat ended cylindrical targets suitable for fetal Doppler performance assessment.

PubMed

Preston, R C; Bond, A D

1997-01-01

The performance of small-diameter targets suitable for use as oscillating targets for testing the sensitivity of Doppler fetal heartbeat detectors has been systematically studied. Experimental results are presented in the 1.6-3.0 MHz frequency range for the plane-wave reflection loss for a total of 16 targets: spherical balls made of stainless steel; hemispherical-ended rods made of PTFE; and flat-ended rods made of stainless steel, PTFE, polycarbonate, and tungsten carbide. Results show that the fine-structure variation of reflection loss with frequency is greatest in the case of spherical ball targets and least for flat-ended targets. It has been shown that, providing care is taken during manufacture, the reflection loss from a flat-ended target can be predicted using a simple theory based on a plane disc reflector. Tungsten carbide targets consisting of a long rod with a diameter of 1.6 mm tapered down to a cylindrical flat end with a diameter of 0.4, 0.5, and 0.6 mm have been shown to provide reflection losses of between 60 and 40 dB, and to have a smooth variation of reflection loss with frequency. They can also be manufactured in a form that allows no significant interference from the supporting structure and, therefore, are ideal targets to meet the requirements of International Electrotechnical Commission 1266:1995.

Evaluation of right ventricular function in early period following transcatheter closure of atrial septal defect.

PubMed

Ağaç, Mustafa Tarık; Akyüz, Ali Rıza; Acar, Zeydin; Akdemir, Ramazan; Korkmaz, Levent; Kırış, Abdülkadir; Erkuş, Emre; Erkan, Hakan; Celik, Sükrü

2012-03-01

There is limited data on alterations in novel right ventricular (RV) function indices like tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic velocity (TASV) after transcatheter atrial septal defect (ASD) closure. We aimed to evaluate RV function by echocardiography (ECG) with these novel indices in early period in patients with secundum-type ASD that was closed percutaneously. Patients were enrolled to study if they had secundum-type ASD that was suitable for percutaneous closure. Patient population consisted of 4 men and 16 women. Echocardiography was performed before and 1 month after closure. Mean age was 37 ± 16. Mean diameter of ASD and total atrial septum length measured by ECG were 19 ± 6 mm and 49 ± 7 mm, respectively. Mean diameter of defect in transesophageal echocardiography was 20 ± 6 mm. Stretched mean diameter in catheterization was 23 ± 6 mm. One month after closure, there were statistically significant decreases in RV end-diastolic diameters (43.3 ± 10.7 mm vs. 34.9 ± 5.5 mm; P < 0.001), RV/left ventricular (LV) end-diastolic diameter ratio (1.1 ± 0.3 vs. 0.87 ± 0.1; P < 0.001), TASV (16.9 ± 3.2 cm/sec vs. 14.3 ± 3.3 cm/sec; P < 0.05), early diastolic tricuspid annular velocity (15.3 ± 3.1 cm/sec vs. 13.4 ± 2.4 cm/sec P <0.05), late diastolic tricuspid annular velocity (16.2 ± 5.4 cm/sec vs. 14.3 ± 6.3 cm/sec; P < 0.05), and TAPSE (29.9 ± 6.2 mm vs. 22.4 ± 7.4 mm; P < 0.001). LV end-diastolic diameter (38.0 ± 6.9 mm and 40.0 ± 4.5 P < 0.05) was increased, whereas there was no change in LV ejection fraction. Closure of ASD by using Amplatzer devices led to decrease in right heart chamber size, tissue Doppler-derived tricuspid annular velocities and TAPSE in early period. © 2011, Wiley Periodicals, Inc.

[Analysis of normal pelvis morphometry of modern Chinese southern Han female and its correlation with age].

PubMed

Liu, Ping; Yu, Yan-Hong; Chen, Chun-Lin; Tang, Yi-Xin; Wang, Li; Mao, Dong-Rui; Xu, Yi-Kai; Chen, Lan

2013-07-01

To analyze the normal pelvis morphometry of Chinese southern Han female and its correlation with age. From August 2009 to September 2011, 289 Han nationality females who received pelvis CT scan at Nanfang Hospital of Southern Medical University were eligible for the study. Their mean age was 43.5 years, with normal body development and no pelvic abnormality. The patients were divided into 3 age groups: 25 to 40 (n = 109), 41 to 50 (n = 115), and >50 years (n = 65). After constructing a three-dimensional digital model of the pelvis, the following parameters were measured, including transverse inlet diameter, posterior sagittal diameter of pelvic inlet, sagittal inlet, diagonal conjugate, biischial diameter, posterior sagittal diameter of midpelvis, sagittal midpelvic diameter, intertuberous distance, posterior sagittal diameter of outlet, angle of pubic arch, sagittal outlet, penal height, sacrum length and sacrum curvature. The relationship between all parameters and age was analyzed. (1) The posterior sagittal diameters of pelvic inlet of the 25 to 40 age group, 41 to 50 age group, >50 years age group were (53 ± 8), (51 ± 7), (48 ± 6) mm. The sagittal inlet of the three groups were (122 ± 8), (120 ± 9), (114 ± 8) mm. And the diagonal conjugate of the three groups were (135 ± 10), (132 ± 9), (127 ± 9) mm. All had significant differences among the three groups (P < 0.01) . (2) The posterior sagittal diameter of midpelvis of the three groups were (43 ± 6), (44 ± 6), (43 ± 7) mm, and the sagittal midpelvic diameter of the three groups were (119 ± 8), (120 ± 8), (119 ± 7) mm, with no significant difference among the three groups (P > 0.05). (3) The intertuberous distance of the three groups were (122 ± 11), (121 ± 10), (117 ± 11) mm, and the posterior sagittal diameter of outlet of the three groups were (56 ± 9), (58 ± 8), (57 ± 9) mm. There was no significant difference among the three groups (P > 0.05) .(4) Penal height of three groups were (31 ± 3), (33 ± 3), (34 ± 3) mm, there was with significant differences (P < 0.01) .(5) Pearson correlation analysis showed that penal height was positively correlated with age (r = 0.331, P < 0.05), while sagittal inlet, posterior sagittal diameter of inlet, diagonal conjugate, intertuberous distance, angle of pubic arch, sacrum length and sacrum curvature were negatively correlated with age (r = -0.120 to -0.343, P < 0.05). The shape of the pelvic inlet of Chinese southern Han female changed from sagittal elliptic into transverse elliptic form, and the posterior part of pelvic inlet became larger.Sacral concavity was increased and the pelvis became deeper. Mid pelvis and the pelvic outlet was almost unchanged, and showed no correlation with age.

Retinal arteriolar remodeling evaluated with adaptive optics camera: Relationship with blood pressure levels.

PubMed

Gallo, A; Mattina, A; Rosenbaum, D; Koch, E; Paques, M; Girerd, X

2016-06-01

To research a retinal arterioles wall-to-lumen ratio or lumen diameter cut-off that would discriminate hypertensive from normal subjects using adaptive optics camera. One thousand and five hundred subjects were consecutively recruited and Adaptive Optics Camera rtx1™ (Imagine-Eyes, Orsay, France) was used to measure wall thickness, internal diameter, to calculate wall-to-lumen ratio (WLR) and wall cross-sectional area of retinal arterioles. Sitting office blood pressure was measured once, just before retinal measurements and office blood pressure was defined as systolic blood pressure>=140mmHg and diastolic blood pressure>=90mmHg. ROC curves were constructed to determine cut-off values for retinal parameters to diagnose office hypertension. In another population of 276 subjects office BP, retinal arterioles evaluation and home blood pressure monitoring were obtained. The applicability of retinal WLR or diameter cut-off values were compared in patients with controlled, masked, white-coat and sustained hypertension. In 1500 patients, a WLR>0.31 discriminated office hypertensive subjects with a 0.57 sensitivity and 0.71 specificity. Lumen diameter<78.2μm discriminated office hypertension with a 0.73 sensitivity and a 0.52 specificity. In the other 276 patients, WLR was higher in sustained hypertension vs normotensive patients (0.330±0.06 vs 0.292±0.05; P<0.001) and diameter was narrower in masked hypertensive vs normotensive subjects (73.0±11.2 vs 78.5±11.6μm; P<0.005). A WLR higher than 0.31 is in favour of office arterial hypertension; a diameter under<78μm may indicate a masked hypertension. Retinal arterioles analysis through adaptive optics camera may help the diagnosis of arterial hypertension, in particular in case of masked hypertension. Copyright © 2016. Published by Elsevier SAS.

The search for valved conduit tissue grafts for adults (>22 mm): an ultrasonographic study of jugular vein diameters of horses and cattle

PubMed Central

Schwarzwald, Colin C; Jenni, Rolf

2009-01-01

Background Natural heterologous valved conduits with a diameter greater than 22 mm that can be used for right ventricular outflow tract reconstruction in adults are not commercially available. The purpose of this study was to measure by ultrasonography the maximum diameter of the distended jugular veins of horses and cattle, respectively, to identify a population of animals that would be suitable for post-mortem collection of jugular veins at sizes greater than 22 mm. Methods The study population included 60 Warmblood horses, 25 Freiberger horses, 20 Brown Swiss cows, and 20 Holstein cows (including 10 Holstein and 10 Red Holstein). The maximum cross-sectional diameter of the distended jugular veins was measured at a location half-way between the mandibular angle and the thoracic inlet. The thoracic circumference (heart girth length) was used as a surrogate of body size. The jugular vein diameters of the different populations were compared by analysis of variance and the association between heart girth length and jugular vein diameter was determined in each of the four study populations by linear regression analysis. Results There was considerable individual variation of jugular vein diameters within each of the four study populations. There was no statistically significant relationship between thoracic circumference and jugular vein diameter in any of the populations. The jugular vein diameters of Brown Swiss cows were significantly larger than those of any of the other populations. Warmblood horses had significantly larger jugular vein diameters compared to Freiberger horses. Conclusion The results of this study suggest that the production of bovine or equine xenografts with diameters of greater than 22 mm would be feasible. Differences between species and breeds need to be considered. However, prediction of the jugular vein diameter based on breed and heart girth length in an individual animal is inaccurate. PMID:19678940

Fresnel Lens Characterization for Potential Use in an Unpiloted Atmospheric Vehicle DIAL Receiver System

NASA Technical Reports Server (NTRS)

Fastig, Shlomo; Deoung, Russell J.

1998-01-01

Acrylic plastic Fresnel lenses are very light and can have large diameters. Such lenses could be used in lidar telescope receivers if the focal spot is not too large or distorted. This research effort characterizes the focal spot diameter produced by a Fresnel lens with a diameter of 30.5 cm (12 in.). It was found that the focal spot diameter varied from 1.2 mm at 750 nm to 1.6 mm at 910 nm. The focal spot was irregular and not easily described by a Gaussian profile.

Potential Bone to Implant Contact Area of Short Versus Standard Implants: An In Vitro Micro-Computed Tomography Analysis.

PubMed

Quaranta, Alessandro; DʼIsidoro, Orlando; Bambini, Fabrizio; Putignano, Angelo

2016-02-01

To compare the available potential bone-implant contact (PBIC) area of standard and short dental implants by micro-computed tomography (μCT) assessment. Three short implants with different diameters (4.5 × 6 mm, 4.1 × 7 mm, and 4.1 × 6 mm) and 2 standard implants (3.5 × 10 mm and 3.3 × 9 mm) with diverse design and surface features were scanned with μCT. Cross-sectional images were obtained. Image data were manually processed to find the plane that corresponds to the most coronal contact point between the crestal bone and implant. The available PBIC was calculated for each sample. Later on, the cross-sectional slices were processed by a 3-dimensional (3D) software, and 3D images of each sample were used for descriptive analysis and display the microtopography and macrotopography. The wide-diameter short implant (4.5 × 6 mm) showed the higher PBIC (210.89 mm) value followed by the standard (178.07 mm and 185.37 mm) and short implants (130.70 mm and 110.70 mm). Wide-diameter short implants show a surface area comparable with standard implants. Micro-CT analysis is a promising technique to evaluate surface area in dental implants with different macrodesign, microdesign, and surface features.

Morphometric analysis of torso arterial anatomy with implications for resuscitative aortic occlusion.

PubMed

Stannard, Adam; Morrison, Jonathan J; Sharon, Danny J; Eliason, Jonathan L; Rasmussen, Todd E

2013-08-01

Hemorrhage is a leading cause of death in military and civilian trauma. Despite the importance of the aorta as a site of hemorrhage control and resuscitative occlusion, detailed knowledge of its morphometry is lacking. The objective of this study was to characterize aortic morphometry in a trauma population, including quantification of distances as well as and diameters and definition of relevant aortic zones. Center line measures were made (Volume Viewer) from contrast computed tomography (CT) scans of male trauma patients (18-45 years). Aortic zones were defined based on branch arteries. Zone I includes left subclavian to celiac; Zone II includes celiac to caudal renal; Zone III includes caudal renal to aortic bifurcation. Zone lengths were calculated and correlated to a novel external measure of torso extent (symphysis pubis to sternal notch). Eighty-eight males (mean [SD], 28 [4] years) had CT scans for the study. The median (interquartile range) lengths (mm) of Zones I, II, and III were 210 mm (202-223 mm), 33 mm (28-38 mm), and 97 mm (91-103 mm), respectively. Median aortic diameters at the left subclavian, celiac, and lowest renal arteries were 21 mm (20-23 mm), 18 mm (16-19 mm), and 15 mm (14-16 mm), respectively, and the terminal aortic diameter was 14 mm (13-15 mm). The correlation of determination for descending aortic length (all zones) against torso extend was r = 0.454. This study provides a morphometric analysis of the aorta in a male population, demonstrating consistency of length and diameter while defining distinct axial zones. Findings suggest that center line aortic distances correlate with a simple, external measure of torso extent. Morphometric study of the aorta using CT data may facilitate the development and implementation of occlusion techniques to manage noncompressible torso, pelvic, and junctional femoral hemorrhage.

[Transcatheter closure of atrial septal defects in 40 pediatric patients].

PubMed

Deng, Dong-an; Zhu, Xian-yang; Hou, Chuan-ju; Han, Xiu-min; Wang, Qi-guang; Jin, Yan; Quan, Wei; Liu, Yang; Wang, Shu-fan

2003-07-01

To evaluate the clinical efficiency of transcatheter closure of atrial septal defect (ASD) with AGA-Amplatzer occlusion device in pediatric patients. Forty patients with ASD, 16 males, 24 females, at a mean age of 10.2 years (ranged from 3 to 15 years of age) and with a mean weight of 35.8 kg (ranged from 11 to 87 kg) were studied. Six cases were complicated with pulmonary stenosis (PS), 1 was complicated with ventricular tachycardia (VT). Right heart catheterizations were done in 40 patients for measuring the pressures of right ventricle and pulmonary artery. The balloon diameter of ASD was measured using balloon catheter with guiding wire. The diameter of ASD was measured by TTE and/or TEE, ascertaining the location and size of ASD. Amplatzer occlusion device was sized to be equal to or 1 - 2 mm more than the diameter of balloon stretched. All patients had successful implantation of the Amplatzer device. The success rate was 100%. The diameter measured by TTE was 7 - 30 mm (mean 17.12 mm). The diameter measured by TEE was 7 - 32 mm (mean 18.44 mm). The diameter of balloon stretched of ASD was 8 - 34 mm. Of the 40 cases, 6 were complicated with PS and accepted percutaneous balloon valvuloplasty (PBPV). One case was complicated with VT and accepted radiofrequency catheter ablation (RFCA). Neither complication nor residual shunt was found in any of the patients. The patients were recovered and followed up for 3 or 4 days after deployment of the Amplatzer device. Clinical symptom, cardiac murmur, and findings in ECG, echocardiography and X-ray were improved markedly. AGA-Amplatzer occlusion device is safe and efficient in pediatric patients with ASD.

1-mm catheterscope

NASA Astrophysics Data System (ADS)

Seibel, Eric J.

2008-02-01

Flexible endoscopes use one sensor element per display pixel. When diameter is reduced to the size of a catheter, there is a significant reduction in the number of pixels within the image. By placing a sub-millimeter microscanner at the tip of a catheter, image quality can be significantly improved. The microscanner consists of a 0.4 mm diameter piezoelectric tube with quadrant electrodes, surrounding a cantilevered singlemode optical fiber. At the distal end, the fiber microscanner is sealed with a 0.9 mm diameter lens assembly, creating a rigid length less than 10 mm at the tip of a highly flexible shaft. The cantilevered fiber is vibrated at the first mode of resonance for bending to generate a circular scan pattern. A spiral scan pattern is generated that constitutes an image frame by modulating the piezoelectric drive signals. By using a custom optical fiber at 80 microns cladding diameter, >10 KHz resonant scanning is achieved, resulting in a 30 Hz frame rate. Red (635 nm), green (532 nm), and blue (442 nm) laser light is scanned by coupling to the fiber scanner. The scanned illumination is detected in a non-confocal arrangement by having one or more optical fibers collecting the backscattered light at MHz pixel rates. Current 1-mm diameter catheterscopes generate 500-line images at maximum fields of view of 100 degrees and spatial resolutions of <20 microns with image zooming. Shaft length of four meters have been fabricated with flexibility of <10 mm bending radius to image previously inaccessible regions of the body.

The Risk Factors for Metastasis in Non-Ampullary Duodenal Neuroendocrine Tumors Measuring 20 mm or Less in Diameter.

PubMed

Hatta, Waku; Koike, Tomoyuki; Iijima, Katsunori; Asanuma, Kiyotaka; Asano, Naoki; Musha, Hiroaki; Inomata, Yoshifumi; Sano, Toshikazu; Endo, Hiroyuki; Ikehata, Atsushi; Horii, Toru; Ohyauchi, Motoki; Yokosawa, Satoshi; Kasajima, Atsuko; Fujishima, Fumiyoshi; Sasano, Hironobu; Nakaya, Naoki; Nakamura, Tomohiro; Shimosegawa, Tooru

2017-01-01

The treatment strategy for non-ampullary duodenal neuroendocrine tumors (NAD-NETs) ≤20 mm in diameter has not been established. In this study, we aimed to evaluate the detailed characteristics of NAD-NETs ≤20 mm in diameter to clarify the risk factors of subsequent metastasis. The patients with NAD-NETs ≤20 mm in diameter who had been treated at 12 institutions between 1992 and 2013 were enrolled. Clinical records were retrieved, and histopathological findings of all cases were centrally reviewed by 2 pathologists. We studied 49 patients with a mean follow-up period of 66.5 months. Thirty-five patients were initially treated with endoscopic resection (ER), and 14 with surgery. A univariate analysis revealed the ORs and 95% CIs of the risk factors for metastasis were lymphovascular invasion (12.5 [2.01-77.9]), multiple tumors (9.75 [1.46-65.4]), a tumor size of 11-20 mm (6.67 [1.21-36.6]), and World Health Organization grade G2 (7.13 [1.16-43.9]). Five-year overall and disease-specific survival rates were 86.1 and 97.2%, respectively. This is the first study to demonstrate the risk factors of metastasis in NAD-NETs ≤20 mm in diameter. These findings may be helpful for determining the appropriate therapeutic approach and the clinical strategy of treatment following ER. © 2017 S. Karger AG, Basel.

Minimizing masses in explosively driven two-shockwave physics applications

NASA Astrophysics Data System (ADS)

Buttler, William; Cherne, Frank; Furlanetto, Michael; Payton, Jeremy; Stone, Joseph; Tabaka, Leonard; Vincent, Samuel

2015-06-01

We have experimentally investigated different two-shockwave high-explosives (HE) physics package designs to maximize the variability of the second shockwave peak stress, while minimizing the total HE load of the physics tool. A critical requirement is to also have a large radial diameter of the second shockwave to maintain its value as an HE driven two-shockwave drive. We have previously shown that we could vary the peak-stress of the second-shockwave with a 76 mm diameter HE lens driving different composite boosters of PBX 9501 and TNT. Here we report on our results with a 56- and 50-mm diameter HE lens driving Baritol. The results indicate that the 56-mm diameter HE lens works well, as does the Baritol, giving total HE loads of about 250 mg TNT equivalent explosives.

Fracture strength of zirconia implant abutments on narrow diameter implants with internal and external implant abutment connections: A study on the titanium resin base concept.

PubMed

Sailer, Irena; Asgeirsson, Asgeir G; Thoma, Daniel S; Fehmer, Vincent; Aspelund, Thor; Özcan, Mutlu; Pjetursson, Bjarni E

2018-04-01

There is limited knowledge regarding the strength of zirconia abutments with internal and external implant abutment connections and zirconia abutments supported by a titanium resin base (Variobase, Straumann) for narrow diameter implants. To compare the fracture strength of narrow diameter abutments with different types of implant abutment connections after chewing simulation. Hundred and twenty identical customized abutments with different materials and implant abutment connections were fabricated for five groups: 1-piece zirconia abutment with internal connection (T1, Cares-abutment-Straumann BL-NC implant, Straumann Switzerland), 1-piece zirconia abutment with external hex connection (T2, Procera abutment-Branemark NP implant, Nobel Biocare, Sweden), 2-piece zirconia abutments with metallic insert for internal connection (T3, Procera abutment-Replace NP implant, Nobel Biocare), 2-piece zirconia abutment on titanium resin base (T4, LavaPlus abutment-VarioBase-Straumann BL-NC implant, 3M ESPE, Germany) and 1-piece titanium abutment with internal connection (C, Cares-abutment-Straumann BL-NC implant, Straumann, Switzerland). All implants had a narrow diameter ranging from 3.3 to 3.5 mm. Sixty un-restored abutments and 60 abutments restored with glass-ceramic crowns were tested. Mean bending moments were compared using ANOVA with p-values adjusted for multiple comparisons using Tukey's procedure. The mean bending moments were 521 ± 33 Ncm (T4), 404 ± 36 Ncm (C), 311 ± 106 Ncm (T1) 265 ± 22 Ncm (T3) and 225 ± 29 (T2) for un-restored abutments and 278 ± 84 Ncm (T4), 302 ± 170 Ncm (C), 190 ± 55 Ncm (T1) 80 ± 102 Ncm (T3) and 125 ± 57 (T2) for restored abutments. For un-restored abutments, C and T4 had similar mean bending moments, significantly higher than those of the three other groups (p < .05). Titanium abutments (C) had significantly higher bending moments than identical zirconia abutments (T1) (p < .05). Zirconia abutments (T1) with internal connection had higher bending moments than zirconia abutments with external connection (T2) (p < .05). For all test groups, the bending moments were significantly reduced when restored with all-ceramic crowns. For narrow diameter abutments, the fracture strength of 2-piece internal connected zirconia abutments fixed on titanium resin bases was similar to those obtained for 1-piece titanium abutments. Narrow diameter zirconia abutments with internal connection exhibited higher fracture strength than zirconia abutments with an external connection. Titanium abutments with an internal connection were significantly stronger than identical zirconia abutments. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Enhancing the Bounce of a Ball

NASA Astrophysics Data System (ADS)

Cross, Rod

2010-10-01

In sports such as baseball, softball, golf, and tennis, a common objective is to hit the ball as fast or as far as possible. Another common objective is to hit the ball so that it spins as fast as possible, since the trajectory of the ball through the air is strongly affected by ball spin. In an attempt to enhance both the coefficient of restitution (COR) and the spin of a golf ball, I conducted several experiments to see what would happen when a 45-g, 42.8-mm diameter golf ball bounced on: (a) a 58-mm diameter, 103-g Super Ball®; (b) an 8-mm thick, 56-mm diameter circular disk of Super Ball material cut from a large Super Ball and glued to a 3.4-kg lead brick; and (c) a 3-mm thick sheet of rubber glued to a 3.4-kg lead brick. (See Fig. 1.)

Effects of Pin Detached Space on Heat Transfer and Pin-Fin Arrays

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

Siw, Sin Chien; Chyu, Minking K.; Shih, Tom I. -P.

2012-01-01

Heat transfer and pressure characteristics in a rectangular channel with pin-fin arrays of partial detachment from one of the endwalls have been experimentally studied. The overall channel geometry (W=76.2 mm, E=25.4 mm) simulates an internal cooling passage of wide aspect ratio (3:1) in a gas turbine airfoil. With a given pin diameter, D=6.35 mm=¼E, three different pin-fin height-to-diameter ratios, H/D=4, 3, and 2, were examined. Each of these three cases corresponds to a specific pin array geometry of detachment spacing (C) between the pin tip and one of the endwalls, i.e., C/D=0, 1, 2, respectively. The Reynolds number, based onmore » the hydraulic diameter of the unobstructed cross-section and the mean bulk velocity, ranges from 10,000 to 25,000. The experiment employs a hybrid technique based on transient liquid crystal imaging to obtain the distributions of the local heat transfer coefficient over all of the participating surfaces, including the endwalls and all the pin elements. Experimental results reveal that the presence of a detached space between the pin tip and the endwall has a significant effect on the convective heat transfer and pressure loss in the channel. The presence of pin-to-endwall spacing promotes wall-flow interaction, generates additional separated shear layers, and augments turbulent transport. In general, an increase in detached spacing, or C/D, leads to lower heat transfer enhancement and pressure drop. However, C/D=1, i.e., H/D=3, of a staggered array configuration exhibits the highest heat transfer enhancement, followed by the cases of C/D=0 and C/D=2, i.e., H/D=4 or 2, respectively.« less

The effect of a finite focal spot size on location dependent detectability in a fan beam CT system

NASA Astrophysics Data System (ADS)

Kim, Byeongjoon; Baek, Jongduk

2017-03-01

A finite focal spot size is one of the sources to degrade the resolution performance in a fan beam CT system. In this work, we investigated the effect of the finite focal spot size on signal detectability. For the evaluation, five spherical objects with diameters of 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm were used. The optical focal spot size viewed at the iso-center was a 1 mm (height) × 1 mm (width) with a target angle of 7 degrees, corresponding to an 8.21 mm (i.e., 1 mm / sin (7°)) focal spot length. Simulated projection data were acquired using 8 × 8 source lets, and reconstructed by Hanning weighted filtered backprojection. For each spherical object, the detectability was calculated at (0 mm, 0 mm) and (0 mm, 200 mm) using two image quality metrics: pixel signal to noise ratio (SNR) and detection SNR. For all signal sizes, the pixel SNR is higher at the iso-center since the noise variance at the off-center is much higher than that at the iso-center due to the backprojection weightings used in direct fan beam reconstruction. In contrast, detection SNR shows similar values for different spherical objects except 1 mm and 2 mm diameter spherical objects. Overall, the results indicate the resolution loss caused by the finite focal spot size degrades the detection performance, especially for small objects with less than 2 mm diameter.

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

Antsiferov, P. S., E-mail: Ants@isan.troitsk.ru; Dorokhin, L. A.

The influence of the discharge cavity dimensions on the properties of the spherical plasma formed in a fast discharge was studied experimentally. The passage of a current pulse with an amplitude of 30–40 kA and a rise rate of ~10{sup 12} A/s (a fast discharge) through a spherical ceramic (Al{sub 2}O{sub 3}) cavity with an inner diameter of 11 mm filled with argon at a pressure of 80 Pa results in the formation of a 1- to 2-mm-diameter spherical plasma with an electron temperature of several tens of electronvolts and a density of 10{sup 18}–10{sup 19} cm{sup –3}. It ismore » shown that an increase in the inner diameter of the discharge cavity from 11 to 21 mm leads to the fourfold increase in the formation time of the spherical plasma and a decrease in the average ion charge. A decrease in the cavity diameter to 7 mm makes the spherical plasma unstable.« less

Measurement of the photoneutron flux density distribution from cylindrical targets

NASA Astrophysics Data System (ADS)

Golovkov, V. M.; Basina, T. N.; Yakovlev, M. R.

1989-09-01

Measurements are performed of the density of photoneutron fluxes from cylindrical targets of2H2O (diameter 64 and height 86 mm), Be (outer diameter 70, inner diameter 40, height 100mm), and238U (diameter 44.5 mm, height 50 mm) under the action of braking radiation from electrons with energies of 4 to 8 MeV in order to determine the effect of target form and orientation relative to the detector upon the recorded photoneutron level. The fluxes were measured by an “all-wave” neutron detector based on an SNM-11 counter in a paraffin retarder at an angle of 90‡ to the axis of the braking radiation beam for various target orientations relative to the detector. Measurement results are compared to calculations. Photoneutron fluxes from heavy water and beryllium targets of the indicated dimensions were also measured for angles of 90, 135, and 167‡. An isotropic nature was noted in the photoneutron fluxes from both targets.

Analysis of lumbar pedicle morphology in degenerative spines using multiplanar reconstruction computed tomography: what can be the reliable index for optimal pedicle screw diameter?

PubMed

Makino, Takahiro; Kaito, Takashi; Fujiwara, Hiroyasu; Yonenobu, Kazuo

2012-08-01

The measurement of transverse pedicle width is still recommended for selecting a screw diameter despite being weakly correlated with the minimum pedicle diameter, except in the upper lumbar spine. The purpose of this study was to reveal the difference between the minimum pedicle diameter and conventional transverse or sagittal pedicle width in degenerative lumbar spines. A total of 50 patients with degenerative lumbar disorders without spondylolysis or lumbar scoliosis of >10° who preoperatively underwent helical CT scans were included. The DICOM data of the scans were reconstructed by imaging software, and the transverse pedicle width (TPW), sagittal pedicle width (SPW), minimum pedicle diameter (MPD), and the cephalocaudal inclination of the pedicles were measured. The mean TPW/SPW/MPD values were 5.46/11.89/5.09 mm at L1, 5.76/10.44/5.39 mm at L2, 7.25/10.23/6.52 mm at L3, 9.01/9.36/6.83 mm at L4, and 12.86/8.95/7.36 mm at L5. There were significant differences between the TPW and MPD at L3, L4, and L5 (p < 0.01) and between the SPW and MPD at all levels (p < 0.01). The MPD was significantly smaller than the TPW and SPW at L3, L4, and L5. The actual measurements of the TPW were not appropriate for use as a direct index for the optimal pedicle screw diameter at these levels. Surgeons should be careful in determining pedicle screw diameter based on plain CT scans especially in the lower lumbar spine.

Pulsed cavitational therapy using high-frequency ultrasound for the treatment of deep vein thrombosis in an in vitro model of human blood clot

NASA Astrophysics Data System (ADS)

Goudot, G.; Mirault, T.; Arnal, B.; Boisson-Vidal, C.; Le Bonniec, B.; Gaussem, P.; Galloula, A.; Tanter, M.; Messas, E.; Pernot, M.

2017-12-01

Post-thrombotic syndrome, a frequent complication of deep venous thrombosis, can be reduced with early vein recanalization. Pulsed cavitational therapy (PCT) using ultrasound is a recent non-invasive approach. We propose to test the efficacy and safety of high-frequency focused PCT for drug-free thrombolysis (thrombotripsy) in a realistic in vitro model of venous thrombosis. To reproduce venous thrombosis conditions, human whole blood was allowed to clot by stasis in silicone tubes (6 mm internal diameter) at a 30 cm H2O pressure, maintained during the whole experiment. We engineered an ultrasound device composed of dual 2.25 MHz transducers centered around a 6 MHz imaging probe. A therapeutic focus was generated at a 3.2 cm depth from the probe. Thrombotripsy was performed by longitudinally scanning the thrombus at three different speeds: 1 mm s-1 (n  =  6) 2 mm s-1 (n  =  6) 3 mm s-1 (n  =  12). Restored outflow was measured every three passages. Filters were placed to evaluate the debris size. Twenty-four occlusive thrombi, of 2.5 cm mean length and 4.4 kPa mean stiffness, were studied. Flow restoration was systematically obtained by nine subsequent passages (4.5 min maximum). By varying the device’s speed, we found an optimal speed of 1 mm s-1 to be efficient for effective recanalization with 90 s (three passages). Within 90 s, flow restoration was of 80, 62 and 74% at respectively 1, 2 and 3 mm s-1. For all groups, cavitation cloud drilled a 1.7 mm mean diameter channel throughout the clot. Debris analysis showed 92% of debris  <10 µm, with no fragment  >  200 µm.

The effect of vessel material properties and pulsatile wall motion on the fixation of a proximal stent of an endovascular graft.

PubMed

Corbett, T J; Molony, D S; Callanan, A; McGloughlin, T M

2011-01-01

Migration is a serious failure mechanism associated with endovascular abdominal aortic aneurysm (AAA) repair (EVAR). The effect of vessel material properties and pulsatile wall motion on stent fixation has not been previously investigated. A proximal stent from a commercially available stent graft was implanted into the proximal neck of silicone rubber abdominal aortic aneurysm models of varying proximal neck stiffness (β=25.39 and 20.44). The stent was then dislodged by placing distal force on the stent struts. The peak force to completely dislodge the stent was measured using a loadcell. Dislodgment was performed at ambient pressure with no flow (NF) and during pulsatile flow (PF) at pressures of 120/80 mmHg and 140/100 mmHg to determine if pulsatile wall motions affected the dislodgement force. An imaging analysis was performed at ambient pressure and at pressures of 120 mmHg and 140 mmHg to investigate diameter changes on the model due to the radial force of the stent and internal pressurisation. Stent displacement forces were ~50% higher in the stiffer model (7.16-8.4 N) than in the more compliant model (3.67-4.21 N). The mean displacement force was significantly reduced by 10.95-12.83% from the case of NF to the case of PF at 120/80 mmHg. A further increase in pressure to 140/120 mmHg had no significant effect on the displacement force. The imaging analysis showed that the diameter in the region of the stent was 0.37 mm greater in the less stiff model at all the pressures which could reduce the fixation of the stent. The results suggest that the fixation of passively fixated aortic stents could be comprised in more compliant walls and that pulsatile motions of the wall can reduce the maximum stent fixation. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

Experimental development of rod pinch diode radiographic source using modified KALI 1000 pulsed power system

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

Satyanarayana, N.; Basu, Shibaji; Rajawat, R.K., E-mail: satya_3026@yahoo.com

2014-07-01

This paper highlights the development of Rod Pinch (RP) diode for flash X-ray generation as intense radiographic source at BARC, Vizag. The typical RP diode employed used a small diameter (1-2 mm) anode rod extended through a cathode circular aperture (5-6 mm inner diameter). The diode chamber is maintained at 10{sup -5} Torr vacuum by a rotary backed diffusion pump. Experiments performed on a modified Kali 1000 Pulsed Power System (300 kV, 30 kA, 100 ns) were aimed at optimizing the source by maximizing the figure of merit (dose @ 1m in rad/spot diameter{sup 2} in mm{sup 2}) with minimizingmore » of the diode impedance. The typical electron beam parameters used in the experiments are 240-270 kV, 20-25 kA, 100 ns, with a few hundreds of kA/cm{sup 2} current density. The optimization resulted in a configuration with tungsten anode rod having dimensions of a 1.6 mm diameter, tapering extension length 5-25 mm beyond the graphite cathode aperture (Cathode disk ID = 5 mm, thickness = 3mm) to produce a radiation dose of 150-200 milli rad at 1 m distance having an estimated spot-size of 1-2 mm. The radiation emitted from a rod-pinch diode is measured using Thermoluminescence dosimeters (TLDs) at an angular interval of 15° on either side of the rod in horizontal and vertical plane. (author)« less

Evaluation of a novel, ultrathin, tip-bending endoscope in a synthetic force-sensing pancreas with comparison to medical guide wires

PubMed Central

Chandler, John E; Lee, Cameron M; Babchanik, Alexander P; Melville, C David; Saunders, Michael D; Seibel, Eric J

2012-01-01

Purpose Direct visualization of pancreatic ductal tissue is critical for early diagnosis of pancreatic diseases and for guiding therapeutic interventions. A novel, ultrathin (5 Fr) scanning fiber endoscope (SFE) with tip-bending capability has been developed specifically to achieve high resolution imaging as a pancreatoscope during endoscopic retrograde cholangiopancreatography (ERCP). This device has potential to dramatically improve both diagnostic and therapeutic capabilities during ERCP by providing direct video feedback and tool guidance to clinicians. Methods Invasiveness of the new tip-bending SFE was evaluated by a performance comparison to ERCP guide wires, which are routinely inserted into the pancreatic duct during ERCP. An in vitro test model with four force sensors embedded in a synthetic pancreas was designed to detect and compare the insertion forces for 0.89 mm and 0.53 mm diameter guide wires as well as the 1.7 mm diameter SFE. Insertions were performed through the working channel of a therapeutic duodenoscope for the two types of guide wires and using a statistically similar direct insertion method for comparison to the SFE. Results Analysis of the forces detected by the sensors showed the smaller diameter 0.53 mm wire produced significantly less average and maximum forces during insertion than the larger diameter 0.89 mm wire. With the use of tip-bending and optical visualization, the 1.7 mm diameter SFE produced significantly less average force during insertion than the 0.89 mm wire at every sensor, despite its larger size. It was further shown that the use of tip-bending with the SFE significantly reduced the forces at all sensors, compared to insertions when tip-bending was not used. Conclusion Combining high quality video imaging with two-axis tip-bending allows a larger diameter guide wire-style device to be inserted into the pancreatic duct during ERCP with improved capacity to perform diagnostics and therapy. PMID:23166452

Anatomic characteristics of ruptured abdominal aortic aneurysm on conventional CT scans: Implications for rupture risk.

PubMed

Fillinger, Mark F; Racusin, Jessica; Baker, Robert K; Cronenwett, Jack L; Teutelink, Arno; Schermerhorn, Marc L; Zwolak, Robert M; Powell, Richard J; Walsh, Daniel B; Rzucidlo, Eva M

2004-06-01

The purpose of this study was to analyze anatomic characteristics of patients with ruptured abdominal aortic aneurysms (AAAs), with conventional two-dimensional computed tomography (CT), including comparison with control subjects matched for age, gender, and size. Records were reviewed to identify all CT scans obtained at Dartmouth-Hitchcock Medical Center or referring hospitals before emergency AAA repair performed because of rupture or acute severe pain (RUP group). CT scans obtained before elective AAA repair (ELEC group) were reviewed for age and gender match with patients in the RUP group. More than 40 variables were measured on each CT scan. Aneurysm diameter matching was achieved by consecutively deleting the largest RUP scan and the smallest ELEC scan to prevent bias. CT scans were analyzed for 259 patients with AAAs: 122 RUP and 137 ELEC. Patients were well matched for age, gender, and other demographic variables or risk factors. Maximum AAA diameter was significantly different in comparisons of all patients (RUP, 6.5 +/- 2 cm vs ELEC, 5.6 +/- 1 cm; P <.0001), and mean diameter of ruptured AAAs was 5 mm smaller in female patients (6.1 +/- 2 cm vs 6.6 +/- 2 cm; P =.007). Two hundred patients were matched for diameter, gender, and age (100 from each group; maximum AAA diameter, 6.0 +/- 1 cm vs 6.0 +/- 1 cm). Analysis of diameter-matched AAAs indicated that most variables were statistically similar in the two groups, including infrarenal neck length (17 +/- 1 mm vs 19 +/- 1 mm; P =.3), maximum thrombus thickness (25 +/- 1 mm vs 23 +/- 1 mm, P =.4), and indices of body habitus, such as [(maximum AAA diameter)/(normal suprarenal aorta diameter)] or [(maximum AAA diameter)/(L3 transverse diameter)]. Multivariate analysis controlling for gender indicated that the most significant variables for rupture were aortic tortuosity (odds ratio [OR] 3.3, indicating greater risk with no or mild tortuosity), diameter asymmetry (OR, 3.2 for a 1-cm difference in major-minor axis), and current smoking (OR, 2.7, with the greater risk in current smokers). When matched for age, gender, and diameter, ruptured AAAs tend to be less tortuous, yet have greater cross-sectional diameter asymmetry. On conventional two-dimensional CT axial sections, it appears that when diameter asymmetry is associated with low aortic tortuosity, the larger diameter on axial sections more accurately reflects rupture risk, and when diameter asymmetry is associated with moderate or severe aortic tortuosity, the smaller diameter on axial sections more accurately reflects rupture risk. Current smoking is significantly associated with rupture, even when controlling for gender and AAA anatomy.

75 FR 20931 - Airworthiness Directives; Eurocopter France (ECF) Model SA-365N1, AS-365N2, AS 365 N3, EC 155B...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-22

... Community. The MCAI AD reports the separation and loss of a stainless steel ring (75 millimeter (mm) in... of a stainless steel ring (75 mm in diameter) from a blade sleeve resulting in severe, high-frequency... information specifies checking the blade sleeve for slippage of the stainless steel ring (75 mm in diameter...

Classification of corkscrew collaterals in thromboangiitis obliterans (Buerger's disease): relationship between corkscrew type and prevalence of ischemic ulcers.

PubMed

Fujii, Yuichi; Soga, Junko; Nakamura, Shuji; Hidaka, Takayuki; Hata, Takaki; Idei, Naomi; Fujimura, Noritaka; Nishioka, Kenji; Chayama, Kazuaki; Kihara, Yasuki; Higashi, Yukihito

2010-08-01

A corkscrew collateral appearance on angiography is one of the diagnostic criteria for Buerger's disease. The purpose of the present study was to classify the angiographic findings of corkscrew collaterals and to evaluate the relationship between corkscrew collateral type and the severity of Buerger's disease. Corkscrew collaterals were assessed on digital subtraction angiography in lower extremities of 28 patients with Buerger's disease (55 limbs). The corkscrew sign was classified into 4 types by size and pattern as follows: type I, artery diameter >2 mm, large helical sign; type II, diameter >1.5 mm and or=1 mm and

Transsacral Osseous Corridor Anatomy Is More Amenable To Screw Insertion In Males: A Biomorphometric Analysis of 280 Pelves.

PubMed

Gras, Florian; Gottschling, Heiko; Schröder, Manuel; Marintschev, Ivan; Hofmann, Gunther O; Burgkart, Rainer

2016-10-01

Percutaneous iliosacral screw placement is the standard procedure for fixation of posterior pelvic ring lesions, although a transsacral screw path is being used more frequently in recent years owing to increased fracture-fixation strength and better ability to fix central and bilateral sacral fractures. However, biomorphometric data for the osseous corridors are limited. Because placement of these screws in a safe and effective manner is crucial to using transsacral screws, we sought to address precise sacral anatomy in more detail to look for anatomic variation in the general population. We asked: (1) What proportion of healthy pelvis specimens have no transsacral corridor at the level of the S1 vertebra owing to sacral dysmorphism? (2) If there is no safe diameter for screw placement in the transsacral S1 corridor, is an increased and thus safe diameter of the transsacral S2 corridor expected? (3) Are there sex-specific differences in sacral anatomy and are these correlated with known anthropometric parameters? CT scans of pelves of 280 healthy patients acquired exclusively for medical indications such as polytrauma (20%), CT angiography (70%), and other reasons (10%), were segmented manually. Using an advanced CT-based image analysis system, the mean shape of all segmented pelves was generated and functioned as a template. On this template, the cylindric transsacral osseous corridor at the level of the S1 and S2 vertebrae was determined manually. Each pelvis then was registered to the template using a free-form registration algorithm to measure the maximum screw corridor diameters on each specimen semiautomatically. Thirty of 280 pelves (11%) had no transsacral S1 corridor owing to sacral dysmorphism. The average of maximum cylindrical diameters of the S1 corridor for the remaining 250 pelves was 12.8 mm (95% CI, 12.1-13.5 mm). A transverse corridor for S2 was found in 279 of 280 pelves, with an average of maximum cylindrical diameter of 11.6 mm (95% CI, 11.3-11.9 mm). Decreasing transsacral S1 corridor diameters are correlated with increasing transsacral S2 corridor diameters (R value for females, -0.260, p < 0.01; for males, -0.311, p < 0.001). Female specimens were more likely to have sacral dysmorphism (defined as a pelvis without a transsacral osseous corridor at the level of the S1 vertebra) than were male specimens (females, 16%; males, 7%; p < 0.003). Furthermore female pelves had smaller-corridor diameters than did male pelves (females versus males for S1: 11.7 mm [95% CI, 10.6-12.8 mm] versus 13.5 mm [95% CI, 12.6-14.4 mm], p < 0.01; and for S2: 10.6 mm [95% CI, 10.1-11.1 mm] versus 12.2 mm [95% CI, 11.8-12.6 mm ], p < 0.0001). Narrow corridors and highly individual, sex-dependent variance of morphologic features of the sacrum make transsacral implant placement technically demanding. Individual preoperative axial-slice CT scan analyses and orthogonal coronal and sagittal reformations are recommended to determine the prevalence of sufficient-sized osseous corridors on both levels for safe screw placements, especially in female patients, owing to their smaller corridor diameters and higher rate of sacral dysmorphism.

The principle of low frictional torque in the Charnley total hip replacement.

PubMed

Wroblewski, B M; Siney, P D; Fleming, P A

2009-07-01

The design of the Charnley total hip replacement follows the principle of low frictional torque. It is based on the largest possible difference between the radius of the femoral head and that of the outer aspect of the acetabular component. The aim is to protect the bone-cement interface by movement taking place at the smaller radius, the articulation. This is achieved in clinical practice by a 22.225 mm diameter head articulating with a 40 mm or 43 mm diameter acetabular component of ultra-high molecular weight polyethylene. We compared the incidence of aseptic loosening of acetabular components with an outer diameter of 40 mm and 43 mm at comparable depths of penetration with a mean follow-up of 17 years (1 to 40). In cases with no measurable wear none of the acetabular components were loose. With increasing acetabular penetration there was an increased incidence of aseptic loosening which reflected the difference in the external radii, with 1.5% at 1 mm, 8.8% at 2 mm, 9.7% at 3 mm and 9.6% at 4 mm of penetration in favour of the larger 43 mm acetabular component. Our findings support the Charnley principle of low frictional torque. The level of the benefit is in keeping with the predicted values.

An amplitude modulated radio frequency plasma generator

NASA Astrophysics Data System (ADS)

Lei, Fan; Li, Xiaoping; Liu, Yanming; Liu, Donglin; Yang, Min; Xie, Kai; Yao, Bo

2017-04-01

A glow discharge plasma generator and diagnostic system has been developed to study the effects of rapidly variable plasmas on electromagnetic wave propagation, mimicking the plasma sheath conditions encountered in space vehicle reentry. The plasma chamber is 400 mm in diameter and 240 mm in length, with a 300-mm-diameter unobstructed clear aperture. Electron densities produced are in the mid 1010 electrons/cm3. An 800 W radio frequency (RF) generator is capacitively coupled through an RF matcher to an internally cooled stainless steel electrode to form the plasma. The RF power is amplitude modulated by a waveform generator that operates at different frequencies. The resulting plasma contains electron density modulations caused by the varying power levels. A 10 GHz microwave horn antenna pair situated on opposite sides of the chamber serves as the source and detector of probe radiation. The microwave power feed to the source horn is split and one portion is sent directly to a high-speed recording oscilloscope. On mixing this with the signal from the pickup horn antenna, the plasma-induced phase shift between the two signals gives the path-integrated electron density with its complete time dependent variation. Care is taken to avoid microwave reflections and extensive shielding is in place to minimize electronic pickup. Data clearly show the low frequency modulation of the electron density as well as higher harmonics and plasma fluctuations.

In Vivo Magnetic Stimulation of Rat Sciatic Nerve With Centimeter- and Millimeter-Scale Solenoid Coils.

PubMed

Kagan, Zachary B; RamRakhyani, Anil Kumar; Lazzi, Gianluca; Normann, Richard A; Warren, David J

2016-11-01

Previous reports of magnetic stimulation of the peripheral nervous system (PNS) used various coil geometries, all with outer diameters larger than 35 mm, and stimulation energies in the 50 J range to evoke neural excitation. Recent reports of central nervous system (CNS) activation used sub-mm-scale solenoid coils with mJ energy levels. The goal of this study was to translate the lower energy levels from the CNS to the PNS via using smaller coils placed in closer proximity to the neural tissue. Such a performance improvement would advance the state of the art of magnetic stimulation and provide a path towards new neuroprosthetic devices. Primarily, we investigated the range of coil outer diameters from 25 mm down to 5 mm to better understand the dependence of coil diameter on energy required for PNS activation. Nine cm- and mm-scale copper solenoid coils, with various resistances, inductances, inner and outer diameters, and heights were compared by quantizing neuromuscular responses to magnetic stimulation via capacitive discharge excitation of rat sciatic nerves in vivo. Additionally, the effects of stimulus duration and coil position were investigated. As opposed to prior work, this study compares a subset of stimulation parameters in an intact nerve preparation, and shows that magnetic stimulation with coils that abut the nerve is a reliable, effective method of neuromuscular stimulation. Although we observed different energies required for neuromuscular activation depending on the coil and excitation parameters used, for the experimental configuration, devices, and stimulus waveform shapes presented in this manuscript, no systematic dependence of PNS activation on coil diameter was found, even for the mm-scale coils investigated herein. However, there was a clear relationship between discharge circuit capacitance and energy required to evoke a neuromuscular response. Coils approximately 12 mm in outer diameter and larger consistently evoked responses, whereas coils 5 mm in outer diameter did not. Furthermore, we observed meaningful neuromuscular excitation when stimulating with energies as low as 20 J. Although this is an improvement over prior work, it is still orders of magnitude greater than the energy required for conventional electrical stimulation, suggesting that these devices are presently not suitable for use in an application requiring continued pulsed stimulation. Nevertheless, these devices are suitable for basic research and as clinical tools that infrequently stimulate, such as in diagnostic applications.

The influence of implantoplasty on the diameter, chemical surface composition, and biocompatibility of titanium implants.

PubMed

Schwarz, Frank; John, Gordon; Becker, Jürgen

2017-09-01

The objective of the study was to assess the influence of implantoplasty (IP) on the diameter, chemical surface composition, and biocompatibility of titanium implants in vitro. Twenty soft tissue-level (TL; machined transmucosal-M and rough endosseous part-SLA) and 20 bone-level (BL; SLA) implants were allocated to IP covering 3 or 6 mm of the structured surface (SLA) area. The samples were subjected to diameter, energy-dispersive X-ray spectroscopy (EDX), and cell viability (ginigval fibroblasts, 6 days) assessments. Median diameter reductions varied between 0.1 (TL 3 mm) and 0.2 mm (TL 6 mm). EDX analysis revealed that IP and M surfaces were characterized by a comparable quantity (Wt%) of elements C, O, Na, Cl, K, and Si, but a significantly different quantity of elements Ti and Al. When compared to SLA surfaces, significant differences were noted for elements C, O, Na, Ti, and Al. At BL implants, the extension of IP (i.e., 3 to 6 mm) was associated with a significant increase in cell viability. IP applied to SLA implants was associated with (i) a minimal diameter reduction, (ii) an undisturbed cell viability, and (iii) a chemical elemental composition comparable to M surfaces. This specific IP procedure appears to be suitable for the management of exposed SLA implant surfaces.

The influence of plain bar on bond strength of geopolymer concrete

NASA Astrophysics Data System (ADS)

Dewi, Evrianti Syntia; Ekaputri, Januarti Jaya

2017-06-01

This paper presents some results of experimental study of bond strength of plain bar embedded in geopolymer concrete. Fly ash class F was used as a raw material activated with alkali solutions. The combination of 8 Molar of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as alkali activators was examined in the mixture with ratio of 2.5 by weight. Nine cubical specimens with a size of 150 × 150 × 150 mm were prepared to measure bond strength and slip between reinforcement and concrete. The influential factors studied for the experimental investigation were the diameter of reinforcement bar, bond area, and concrete cover to diameter (c/d) of reinforcement. The result showed that the average bond strength decreased as the diameter of plain bar and bonded length were increased from 16 mm to 19 mm. However, the 12 mm showed the different result allegedly caused by the effect of bond area and the passive confined provided by the concrete. Based on several equations used to compare the bond strength, it is clear that deformed bar of 12 mm in diameter is potential to increase the bond strength.

Comparison of Epidermal/Dermal Damage Between the Long-Pulsed 1064 nm Nd:YAG and 755 nm Alexandrite Lasers Under Relatively High Fluence Conditions: Quantitative and Histological Assessments

PubMed Central

Lee, Ju Hwan; Park, So Ra; Jo, Jeong Ho; Park, Sung Yun; Seo, Young Kwon

2014-01-01

Abstract Objective: The purpose of this study was to compare degrees of epidermal/dermal tissue damage quantitatively and histologically after laser irradiation, to find ideal treatment conditions with relatively high fluence for skin rejuvenation. Background data: A number of recent studies have evaluated the clinical efficacy and safety of therapeutic lasers under relatively low fluence conditions. Methods: We transmitted the long-pulsed 1064 nm Nd:YAG and 755 nm Alexandrite lasers into pig skin according to different fluences and spot diameters, and estimated epidermal/dermal temperatures. Pig skin specimens were stained with hematoxylin and eosin for histological assessments. The fluence conditions comprised 26, 30, and 36 J/cm2, and the spot diameter conditions were 5, 8, and 10 mm. Pulse duration was 30 ms for all experiments. Results: Both lasers produced reliable thermal damage on the dermis without any serious epidermal injuries, under relatively high fluence conditions. The 1064 nm laser provided more active fibrous formations than the 755 nm laser, while higher risks for tissue damages simultaneously occurred. Conclusions: The ideal treatment conditions for skin rejuvenation were 8 mm diameter with 30 J/cm2 and 10 mm diameter with 26 J/cm2 for the 1064 nm laser, and 8 mm diameter with 36 J/cm2 and 10 mm diameter with 26 J/cm2 for the 755 nm laser. PMID:24992273

Whole-globe biomechanics using high-field MRI.

PubMed

Voorhees, Andrew P; Ho, Leon C; Jan, Ning-Jiun; Tran, Huong; van der Merwe, Yolandi; Chan, Kevin; Sigal, Ian A

2017-07-01

The eye is a complex structure composed of several interconnected tissues acting together, across the whole globe, to resist deformation due to intraocular pressure (IOP). However, most work in the ocular biomechanics field only examines the response to IOP over smaller regions of the eye. We used high-field MRI to measure IOP induced ocular displacements and deformations over the whole globe. Seven sheep eyes were obtained from a local abattoir and imaged within 48 h using MRI at multiple levels of IOP. IOP was controlled with a gravity perfusion system and a cannula inserted into the anterior chamber. T2-weighted imaging was performed to the eyes serially at 0 mmHg, 10 mmHg, 20 mmHg and 40 mmHg of IOP using a 9.4 T MRI scanner. Manual morphometry was conducted using 3D visualization software to quantify IOP-induced effects at the globe scale (e.g. axial length and equatorial diameters) or optic nerve head scale (e.g. canal diameter, peripapillary sclera bowing). Measurement sensitivity analysis was conducted to determine measurement precision. High-field MRI revealed an outward bowing of the posterior sclera and anterior bulging of the cornea due to IOP elevation. Increments in IOP from 10 to 40 mmHg caused measurable increases in axial length in 6 of 7 eyes of 7.9 ± 5.7% (mean ± SD). Changes in equatorial diameter were minimal, 0.4 ± 1.2% between 10 and 40 mmHg, and in all cases less than the measurement sensitivity. The effects were nonlinear, with larger deformations at normal IOPs (10-20 mmHg) than at elevated IOPs (20-40 mmHg). IOP also caused measurable increases in the nasal-temporal scleral canal diameter of 13.4 ± 9.7% between 0 and 20 mmHg, but not in the superior-inferior diameter. This study demonstrates that high-field MRI can be used to visualize and measure simultaneously the effects of IOP over the whole globe, including the effects on axial length and equatorial diameter, posterior sclera displacement and bowing, and even changes in scleral canal diameter. The fact that the equatorial diameter did not change with IOP, in agreement with previous studies, indicates that a fixed boundary condition is a reasonable assumption for half globe inflation tests and computational models. Our results demonstrate the potential of high-field MRI to contribute to understanding ocular biomechanics, and specifically of the effects of IOP in large animal models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Blast Wave Experiments at Z

DTIC Science & Technology

2007-06-01

radiation flows upward, it passes though a 1.7-mm high, tapered, 25-μm thick gold wall cone that is filled 20 ± 3 mg/cm3 silica aerogel (SiO2). Above...this cone is a 20 ± 3 mg/cm3 silica aerogel filled, 1-mm high, 2.4-mm inner diameter, 25-μm thick gold wall cylinder. On the cylinder rests a 4-mm...diameter gold platform that supports a higher density (40-60 mg/cm3) silica aerogel . This aerogel is the region where the blast wave forms after

Single crystal growth of submillimeter diameter sapphire tube by the micro-pulling down method

NASA Astrophysics Data System (ADS)

Kamada, Kei; Murakami, Rikito; Kochurikhin, Vladimir V.; Luidmila, Gushchina; Jin Kim, Kyoung; Shoji, Yasuhiro; Yamaji, Akihiro; Kurosawa, Shunsuke; Ohashi, Yuji; Yokota, Yuui; Yoshikawa, Akira

2018-06-01

This paper addresses several aspects of the μ-PD growth technology as applied to submillimeter diameter sapphire tubes for UFD application. The μ-PD method has been successfully adapted for single crystal sapphire tube growth. A compound crucible made possible the growth of single crystal sapphire tube as small as around 0.70-0.72 mm in outer diameter and 0.28-0.29 in inner diameter over 160 mm in length at growth rate of 2-4 mm/min along 〈0 0 1〉 direction. An Ir crucible with a die composed of an equivalent hole and Ir wire was heated by RF coil in N2 atmosphere. The μ-PD method has been successfully adapted for single crystal sapphire tube growth. Grown crystal tube showed good XRC value of 30.2 arcsec.

Natural history of moderately dilated tubular ascending aorta: implications for determining the optimal imaging interval.

PubMed

Park, Kay-Hyun; Chung, Suryeun; Kim, Dong Jung; Kim, Jun Sung; Lim, Cheong

2017-05-01

For a moderately dilated ascending aorta (diameter 35-54 mm), current guidelines recommend continuous annual or semi-annual examinations with computed tomography or magnetic resonance imaging. However, few data have shown the yield and benefit of such a protocol. This study aimed to investigate the fate of a moderately dilated ascending aorta and thereby determine the adequate imaging interval. In our institutional database, we identified adult patients having an ascending aortic diameter ≥40 mm in contrast-enhanced computed tomography and follow-up imaging(s) after ≥1 year. Of the 509 patients (mean age 67.2 ± 10.4 years) enrolled in the study, the maximal diameter of the ascending aorta was compared between the first and last images. Also, their medical records were reviewed to investigate the associated illness and clinical events. The mean growth rate of the patients with a 40-44 mm ( n  = 321), 45-49 mm ( n  = 142) and ≥50 mm ( n  = 46) ascending aorta was 0.3 ± 0.5, 0.3 ± 0.5 and 0.7 ± 0.9 mm/year, respectively. During the mean interval of 4.3 ± 2.4 years, significant progression (diameter increase by ≥5 mm) occurred in 3.4, 5.6 and 21.7%, respectively. The 3- to 5-year rates of freedom from significant progression were 99.1%-96.5% (40-44 mm) and 97.8%-96.4% (45-49 mm). In multivariate analysis, initial ascending aortic diameter ≥45 mm and aortic valve regurgitation were significantly associated with significant progression. Acute type A aortic dissection occurred in 5 patients (1%), before the maximal diameter of the ascending aorta reached 55 mm or significant progression was observed. For a moderately dilated ascending aorta not exceeding 45 mm in maximal diameter and stable in the first annual follow-up image, a 3- to 4-year interval would be reasonable before subsequent imaging. More frequent imaging may be warranted in patients with aortic valve insufficiency or with an aortic diameter ≥45 mm. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Elasticity assessment of electrospun nanofibrous vascular grafts: a comparison with femoral ovine arteries.

PubMed

Bagnasco, D Suarez; Ballarin, F Montini; Cymberknop, L J; Balay, G; Negreira, C; Abraham, G A; Armentano, R L

2014-12-01

Development of successful small-diameter vascular grafts constitutes a real challenge to biomaterial engineering. In most cases these grafts fail in-vivo due to the presence of a mechanical mismatch between the native vessel and the vascular graft. Biomechanical characterization of real native vessels provides significant information for synthetic graft development. Electrospun nanofibrous vascular grafts emerge as a potential tailor made solution to this problem. PLLA-electrospun nanofibrous tubular structures were prepared and selected as model bioresorbable grafts. An experimental setup, using gold standard and high resolution ultrasound techniques, was adapted to characterize in vitro the poly(L-lactic acid) (PLLA) electrospun structures. The grafts were subjected to near physiologic pulsated pressure conditions, following the pressure-diameter loop approach and the criteria stated in the international standard for cardiovascular implants-tubular vascular prostheses. Additionally, ovine femoral arteries were subjected to a similar evaluation. Measurements of pressure and diameter variations allowed the estimation of dynamical compliance (%C, 10(-2) mmHg) and the pressure-strain elastic modulus (E(Pε), 10(6) dyn cm(-2)) of the abovementioned vessels (grafts and arteries). Nanofibrous PLLA showed a decrease in %C (1.38±0.21, 0.93±0.13 and 0.76±0.15) concomitant to an increase in EPε (10.57±0.97, 14.31±1.47 and 17.63±2.61) corresponding to pressure ranges of 50 to 90 mmHg, 80 to 120 mmHg and 100 to 150 mmHg, respectively. Furthermore, femoral arteries exhibited a decrease in %C (8.52±1.15 and 0.79±0.20) and an increase in E(Pε) (1.66±0.30 and 15.76±4.78) corresponding to pressure ranges of 50-90 mmHg (elastin zone) and 100-130 mmHg (collagen zone). Arterial mechanics framework, extensively applied in our previous works, was successfully used to characterize PLLA vascular grafts in vitro, although its application can be directly extended to in vivo experiences, in conscious and chronically instrumented animals. The specific design and construction of the electrospun nanofibrous PLLA vascular grafts assessed in this work, showed similar mechanical properties as the ones observed in femoral arteries, at the collagen pressure range. Copyright © 2014 Elsevier B.V. All rights reserved.

The Volumetric Imaging System for the Ionosphere (VISION)

DTIC Science & Technology

2011-01-01

telescope mirror is an 80 mm focal length, 50 mm diameter, first surface mirror with magnesium fluoride over aluminum coating on a zerodur blank...will be either a wedge–and–strip anode or a codacon. The telescope mirror is an 80 mm focal length, 2.5 cm diameter, first surface mirror with...magnesium fluoride over aluminum coating on a zerodur blank. The filters are the three reflection bandpass filters developed for and flown on

Determination of Graphite-Liquid-Vapor Triple Point by Laser Heating

DTIC Science & Technology

1976-01-30

difficulties in the temperature measure- ments, which were made with an optical pyrometer . He considered that the failure of graphite rod was caused by...temperature measurements were made with a calibrated optical pyrometer . Spherical shiny frozen droplets of graphite, 1 to 3 mm in diameter, indicated...0.8 mm in diameter and 10 mm long in argon until failure by rupture occurred. They measured the tempera- ture with a two-color pyrometer . The

Morphometry of A1 segment of the anterior cerebral artery and its clinical importance.

PubMed

Krishnamurthy, A; Nayak, S R; Bagoji, I B; D'Costa, S; Pai, M M; Jiji, P J; Kumar, C G; Rai, R

2010-01-01

Anterior cerebral artery, one of the terminal branches of the internal carotid artery is an important vessel taking part in the formation of circle of Willis. It supplies a large part of the medial surface of the cerebral hemisphere containing the areas of motor and somatosensory cortices of the lower limb. Aim of this study was the morphometry of A1 segment of the anterior cerebral artery. 93 formalin fixed brain specimen of either sex and of Indian origin were studied. The mean length, mean external diameter and the anomalies present in A1 segment of the vessel were studied in detail and photographed. The mean length of A1 segment of the vessel was 14.49+/-0.28 mm and 14.22+/-0.22 mm on right and left side respectively. The mean external diameter of the vessel on right and left side was 2.12+/-0.07 mm and 2.32+/-0.06 mm respectively. Narrowing, aneurysm formation, buttonhole formation and median anterior cerebral artery were the anomalies seen with an occurrence of 15.05%, 5.37%, 3.22% and 12.9%, respectively. The above anomalies did not have any sex or side predilection. Knowledge of morphometry of the vessel will be of use to neurosurgeons while performing the shunt operation, in assessing the feasibility of such operations and in the choice of patients. From this study we infer that the morphometry of anterior cerebral artery varies in different population and that the neurosurgeons operating should have a thorough knowledge of the possible variations.

Excretion rates of indigestible plastic balls of different specific gravities and diameters in dairy cattle.

PubMed

Seyama, Tomohiro; Hirayasu, Hirofumi; Kasai, Koji

2017-01-01

We used plastic balls to investigate how their specific gravity and diameter affect excretion rate and rumination in dairy cattle, to develop a capsule that can be used for reaching the lower gastrointestinal tract without physical breakdown and/or degradation in the rumen. Twelve types of indigestible plastic balls composed of a combination of four specific gravities (0.95, 1.19, 1.41, or 2.20) and three diameters (3.97, 6.35, or 7.94 mm) were orally administered to lactating dairy cows, and the balls were collected from feces, after 120 h post-administration, to evaluate the recovery rate. Recovery rate of the balls with specific gravity 1.19 or 1.41 and diameter 6.35 or 7.94 mm was higher than those with specific gravity 0.95 or 2.20 and diameter 3.97 mm. The cumulative recovery rate at 24 and 48 h post-administration was higher for balls with specific gravity 1.19 than that for balls with other specific gravities. These results suggest that specific gravity 1.19 or 1.41 and diameters 6.35-7.94 mm are optimal for use in bypass capsules for administration to cattle. In addition, the passage time of capsules differed between specific gravities 1.19 and 1.41. © 2016 Japanese Society of Animal Science.

Fiber-Supported Droplet Combustion. Experiment 32

NASA Technical Reports Server (NTRS)

Dietrich, Daniel L.; Haggard, John B., Jr.; Nayagam, Vedha; Dryer, Frederick L.; Williams, Forman A.; Shaw, Ben D.

1998-01-01

Individual droplets with diameters ranging from about 2 mm to 5 mm were burned under microgravity conditions in air at 1 bar with an ambient temperature of 300 K. Each droplet was tethered by a silicon carbide fiber of 80 mm or 150 mm diameter to keep it in view of video recording, and, in some tests, a forced air flow was applied in a direction parallel to the fiber axis. Methanol, two methanol-water mixtures, two methanol-dodecanol mixtures, and two heptane-hexadecane mixtures were the fuels. Droplet diameters were measured as functions of time and compared with existing theoretical predictions. The prediction that methanol droplets extinguish at diameters that increase with increasing initial droplet diameter is verified by these experiments. In addition, the quasi-steady burning rate constant of the heptane-hexadecane mixtures appears to decrease with increasing droplet diameter; obscuration consistent with very heavy sooting, but without the formation of soot shells, is observed for the largest of these droplets. Forced convective flow around methanol droplets was found to increase the burning rate and to produce a ratio of downstream-to-upstream flame radius that remained constant as the droplet size decreased, a trend in agreement with earlier results obtained at higher convective velocities for smaller droplets having larger flame standoff ratios. There are a number of implications of the experimental results regarding droplet-combustion theory.

Pulsed dye laser treatment of rosacea using a novel 15 mm diameter treatment beam.

PubMed

Bernstein, Eric F; Schomacker, Kevin; Paranjape, Amit; Jones, Christopher J

2018-04-10

The pulsed-dye laser has been used to treat facial redness and rosacea for decades. Recent advances in dye laser technology enable 50% higher output energies supporting 50% larger treatment areas, and beam-diameters up to 15 mm with clinically-relevant fluences. In this study, we investigate this novel pulsed-dye laser using a 15 mm diameter beam for treatment of rosacea. Twenty subjects with erythemato-telangiectatic rosacea were enrolled in the study. A total of 4 monthly treatments were administered, first treating linear vessels with a 3 × 10 mm elliptical beam, then diffuse redness with a 15-mm diameter circular beam. Blinded assessment of digital, cross-polarized photographs taken 2 months following the last treatment was performed using an 11-point clearance scale. Nineteen subjects completed the study. Blinded reviewers correctly identified baseline photos in 55 out of the total of 57 images (96.5%). The blinded reviewers scored 17 of the 19 subjects with an improvement greater than 40%, and 11 of the 19 subjects greater than 50%. The average improvement was 53.9%. Side effects were limited to mild edema, mild to moderate erythema, and mild to moderate bruising. This study demonstrates that a newly designed pulsed-dye laser having a novel 15-mm diameter treatment beam improves the appearance of rosacea with a favorable safety profile. Lasers Surg. Med. 9999:1-5, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Effects of acute exercise on the diameter of the spermatic vein, and duration of reflux in patients with varicocele.

PubMed

Atar, Murat; Söylemez, Haluk; Oguz, Fatih; Beytur, Ali; Altunoluk, Bülent; Kahraman, Bayram; Islamoglu, Yahya; Soylu, Ahmet

2013-06-01

The aim of this study was to investigate the effects of acute exercise on the diameter of the spermatic vein, and on the duration of reflux in patients with varicocele. The study included 38 patients with complaints of infertility and scrotal pain between 2009 and 2010. The diagnoses were made by physical examination and colour Doppler ultrasound, with both performed before and after exercise tests. The mean age of the participants was 25.7 ± 4.9 years. During the first examination, the grades of the varicoceles detected were as follows: grade I, n = 7; II, n = 10; and III, n = 21. The diameters of veins in patients with grades I, II and III varicocele were 2.1 mm, 2.9 mm and 4.2 mm, respectively, before exercise, whereas they were 2.6 mm, 3.2 mm and 4.3 mm, respectively, after exercise. In patients with grade I varicoceles, compared with pre-exercise values, the diameter of the left spermatic vein and duration of reflux measured during Valsalva manoeuvres were increased significantly after exercise (p = 0.042 and p = 0.034, respectively); similar results were obtained for the patients with grade II varicoceles (p = 0.007 and p = 0.008, respectively). However, the minimal relative increase in cases with grade III varicoceles was not statistically significant (p > 0.05). This study demonstrates that acute exercise increases the spermatic vein diameter and reflux time in patients with varicoceles. These outcomes demonstrate that acute exercise may be an aggravating factor for varicocele, as seen in chronic exercise.

Comparison of the stability of various internal fixators used in the treatment of osteochondritis dissecans--a mechanical model.

PubMed

Morelli, Moreno; Poitras, Philippe; Grimes, Valentine; Backman, David; Dervin, Geoffrey

2007-04-01

The purpose of this study was to determine what characteristics of fixation devices used in the treatment of osteochondritis dissecans (OCD) contribute to improved stability to resist shear loading. An OCD model was designed using rigid polyurethane foam. Each specimen consisted of two components, an osteochondral fragment and a corresponding defect. A total of 40 specimens were prepared and assigned to one of four groups: control (no extrinsic stabilizer); two 2-mm-diameter Kirschner wires (K-wires), 40 mm in length; one threaded washer and a 28-mm screw; and one threaded washer and a 38 mm screw. Each specimen was mounted onto an Iosipescu shear test fixture and subjected to shear loads at a pseudo-static displacement rate of 0.075 mm/s. All groups demonstrated some stability; controls were significantly less stable than all other groups. The group with the threaded washer and 38-mm screw demonstrated the greatest stability (p < 0.001), and no difference was noted between the K-wire and 28-mm screw groups. These results suggest that, in this OCD model, friction conferred some intrinsic stability to resist loads in shear. However, stability was improved with the use of long implants that compressed the fragments together.

Effect of Delayed Bonding and Antioxidant Application on the Bond Strength to Enamel after Internal Bleaching.

PubMed

Kılınç, Halil İbrahim; Aslan, Tuğrul; Kılıç, Kerem; Er, Özgür; Kurt, Gökmen

2016-07-01

This study evaluated the effect of delayed bonding and antioxidant application (AA, 10% sodium ascorbate) after internal bleaching (35% carbamide peroxide) on the shear bond strength of an adhesive cement to enamel. Eighty-four human maxillary central incisors were endodontically treated. The control group remained unbleached with no AA. Experimental groups were all internally bleached. The buccal enamel was finished and polished with metallographic paper to a refinement of #600, in order to obtain a 5-mm(2) flat bonding area. An adhesive cement (Clearfil Esthetic) was placed into a plastic tube with internal diameter of 3 mm and a 3-mm height and cured on the enamel. Bonding occurred either immediately after bleaching (group Im), a 7-day delay (group 7), or a 14-day delay (group 14), and half the specimens were treated with antioxidant application (groups Im-AA, 7-AA, and 14-AA). Shear bond strength testing was performed on a universal testing machine, and data were analyzed with ANOVA and Fisher test (5%). Delaying of bonding is a useful factor for enhancing shear bond strength (p < 0.05), whereas AA only enhanced shear bond strength after 7 days delayed bleaching (p < 0.05). The highest bond strength was noted in groups 7-AA (20.51 ± 4.5 MPa), 14 (19.82 ± 4.6), 14-AA (20.27 ± 4.4), and control (20.51 ± 5.1), which were not significantly different from each other. After internal bleaching, adhesive cementation to enamel is recommended only when delayed 14 days, or delayed 7 days with sodium ascorbate application. © 2015 by the American College of Prosthodontists.

A Comparison of the Marginal and Internal Fit of Cobalt- Chromium Copings Fabricated by Two Different CAD/CAM Systems (CAD/ Milling, CAD/ Ceramill Sintron).

PubMed

Vojdani, Mahroo; Torabi, Kianoosh; Atashkar, Berivan; Heidari, Hossein; Torabi Ardakani, Mahshid

2016-12-01

Marginal fitness is the most important criteria for evaluation of the clinical acceptability of a cast restoration. Marginal gap which is due to cement solubility and plaque retention is potentially detrimental to both tooth and periodontal tissues. This in vitro study aimed to evaluate the marginal and internal fit of cobalt- chromium (Co-Cr) copings fabricated by two different CAD/CAM systems: (CAD/ milling and CAD/ Ceramill Sintron). We prepared one machined standard stainless steel master model with following dimensions: 7 mm height, 5mm diameter, 90˚ shoulder marginal finish line with 1 mm width, 10˚ convergence angle and anti-rotational surface on the buccal aspect of the die. There were 10 copings produced from hard presintered Co-Cr blocks according to CAD/ Milling technique and ten copings from soft non- presintered Co-Cr blocks according to CAD/ Ceramill Sintron technique. Marginal and internal accuracies of copings were documented by the replica technique. Replicas were examined at ten reference points under a digital microscope (230X). The Student's t-test was used for statistical analysis. p < 0.001 was considered significant. Statistically significant differences existed between the groups ( p < 0.001). The CAD/milling group (hard copings) had a mean marginal discrepancy (MD) of 104 µm, axial discrepancy (AD) of 23 µm and occlusal discrepancy of 130 µm. For CAD/ Ceramill Sintron group, these values were 195 µm (MD), 46 µm (AD), and 232 µm (OD). Internal total discrepancy (ITD) for the CAD/milling group was 77 µm, whereas for the CAD/Ceramill Sintron group was 143 µm. Hard presintered Co-Cr copings had significantly higher marginal and internal accuracies compared to the soft non-presintered copings.

Surface flux density distribution characteristics of bulk high- Tc superconductor in external magnetic field

NASA Astrophysics Data System (ADS)

Torii, S.; Yuasa, K.

2004-10-01

Various magnetic levitation systems using oxide superconductors are developed as strong pinning forces are obtained in melt-processed bulk. However, the trapped flux of superconductor is moved by flux creep and fluctuating magnetic field. Therefore, to examine the internal condition of superconductor, the authors measure the dynamic surface flux density distribution of YBCO bulk. Flux density measurement system has a structure with the air-core coil and the Hall sensors. Ten Hall sensors are arranged in series. The YBCO bulk, which has 25 mm diameter and 13 mm thickness, is field cooled by liquid nitrogen. After that, magnetic field is changed by the air-core coil. This paper describes about the measured results of flux density distribution of YBCO bulk in the various frequencies of air-core coils currents.

Investigation of Infant Brain with or without Hydrocephalous in Our Environment Using Anterior Transfontanelle Ultrasound Scan.

PubMed

Marchie, Tobechukwu T; Ayara, Charles O

2013-01-01

A prospective study aimed to suggest easy and simple reproducible ventricular site that will be basic measurement plane and normal dimension determined, correlated to sizes of infants for comparative evaluation of hydrocephalous infants and should be reproducible in follow-up. A prospective study done in University of Benin Teaching Hospital Benin, Nigeria. This study used 50 consecutive infants with Ultrasound scan (US) diagnosis of hydrocephalus and a control group of 50 US normal from 1(st) January 2007 to 30(th) June 2008. The infants were scan through the mid-patent anterior fontanelle in sagittal, and transverse planes with minor angulations to properly outline the ventricles and the position of measurement determined at the foramen of Monro of lateral ventricles and the diameter measured. The infants' weight, crown-heel length, and head circumference were measured and body mass index (BMI) calculated and correlated to lateral ventricular measurement. Data analysis was conducted using the Statistical Package for Social Sciences (SPSS Inc, USA), Version 11.0. There was no statistically sex and age-related difference. There is statistically comparative high mean weight and height and lower BMI in hydrocephalic infants as against the control group (P < 0.001). The mean head circumference for hydrocephalus was 45.6 (± 10.5 standard deviation [SD]), whereas the control group was 35.9 (± 2.7 SD) with P < 0.001. The mean diameter of the anterior horn of left and right lateral ventricles at the level of foramen of Monro in hydrocephalic subjects is 18.4 mm ± 14.3 mm and 20.1 mm ± 16.8 mm with median diameter of 14.1 mm and 15.2 mm, respectively, whereas control group is 2.5 mm ± 0.6 mm and 2.5 mm ± 0.7 mm with median diameter of 2.5 mm and 2.4 mm, respectively. Transfontanelle US was found highly useful in investigation of hydrocephalous in infant.

Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data

PubMed Central

LAZARI, Priscilla Cardoso; de OLIVEIRA, Rodrigo Caldeira Nunes; ANCHIETA, Rodolfo Bruniera; de ALMEIDA, Erika Oliveira; FREITAS JUNIOR, Amilcar Chagas; KINA, Sidney; ROCHA, Eduardo Passos

2013-01-01

Objective The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis. Material and Methods Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σmax) values were evaluated for the root dentin, cement layer, and glass fiber post. Results: The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa). Conclusion The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root. PMID:24473716

Electronically steerable ultrasound-driven long narrow air stream

NASA Astrophysics Data System (ADS)

Hasegawa, Keisuke; Qiu, Liwei; Noda, Akihito; Inoue, Seki; Shinoda, Hiroyuki

2017-08-01

Acoustic streaming, which is the unidirectional movement of a medium driven by its internal intense acoustic vibrations, has been known for more than a century. Despite the long history of research, there have been no scientific reports on the creation of long stretching steerable airflows in an open space, generated by ultrasound. Here, we demonstrated the creation of a narrow, straight flow in air to a distance of 400 mm from an ultrasound phased array emitting a Bessel beam. We also demonstrated that the direction of the flow could be controlled by appropriately tuning the wavefronts of the emission from the phased array. Unlike conventional airflows such as those generated by jets or fans, which decelerate and spread out as they travel farther, the flow that we created proceeded while being accelerated by the kinetic energy supplied from the ultrasound beam and keeping the diameter as small as the wavelength. A flow of 3 m/s with a 10 mm diameter extended for several hundreds of millimeters in a room that was large enough to be regarded as an open-boundary environment. These properties of the generated flow will enable fine and rapid control of three-dimensional airflow distributions.

Concurrent Angioplasty Balloon Placement for Stent Delivery through Jugular Venous Bulb for Treating Cerebral Venous Sinus Stenosis. Technical Report.

PubMed

Qureshi, Adnan I; Khan, Asif A; Capistrant, Rachel; Qureshi, Mushtaq H; Xie, Kevin; Suri, M Fareed K

2016-10-01

To report upon technique of concurrent placement of angioplasty balloon at the internal jugular vein and sigmoid venous sinus junction to facilitate stent delivery in two patients in whom stent delivery past the jugular bulb was not possible. A 21-year-old woman and a 41-year-old woman with worsening headaches, visual obscuration or diplopia were treated for pseudotumor cerebri associated with transverse venous stenosis. Both patients had undergone primary angioplasty, which resulted in improvement in clinical symptoms followed by the recurrence of symptoms with restenosis at the site of angioplasty. After multiple attempts at stent delivery through jugular venous bulb were unsuccessful, a second guide catheter was placed in the ipsilateral internal jugular vein through contralateral femoral venous approach. A 6 mm × 20 mm (left) or 5 × 15 mm (right) angioplasty balloon was placed across the internal jugular vein and sigmoid sinus junction and partially inflated until the inflation and relative straightening of the junction was observed. In both patients, the internal jugular vein and sigmoid sinus junction was successfully traversed by the stent delivery system in a parallel alignment to inflated balloon. Balloon mounted stent was deployed at the site of restenosis with near complete resolution of lumen narrowing delivery and improvement in clinical symptoms. We report a technique for realignment and diameter change with concurrent placement and partial inflation of angioplasty balloon at the jugular venous bulb to facilitate stent delivery into the sigmoid and transverse venous sinuses in circumstances where multiple attempts at stent delivery are unsuccessful.

A solar-pumped Nd:YAG laser in the high collection efficiency regime

NASA Astrophysics Data System (ADS)

Lando, Mordechai; Kagan, Jacob; Linyekin, Boris; Dobrusin, Vadim

2003-07-01

Solar-pumped lasers can be used for space and terrestrial applications. We report on solar side-pumped Nd:YAG laser experiments, which included comprehensive beam quality measurements and demonstrated record collection efficiency and day long operation. A 6.75 m 2 segmented primary mirror was mounted on a commercial two-axis positioner and focused the solar radiation towards a stationary non-imaging-optics secondary concentrator, which illuminated a Nd:YAG laser rod. Solar side-pumped laser experiments were conducted in both the low and the high pumping density regimes. The low density system was composed of a 89 × 98-mm 2 aperture two-dimensional compound parabolic concentrator (CPC) and a 10-mm diameter 130-mm long Nd:YAG laser rod. The laser emitted up to 46 W and operated continuously for 5 h. The high density system was composed of a three-dimensional CPC with 98 mm entrance diameter and 24 mm exit diameter, followed by a two-dimensional CPC with a rectangular 24 × 33 mm 2 aperture. It pumped a 6-mm diameter 72 mm long Nd:YAG laser rod, which emitted up to 45 W. The results constitute a record collection efficiency of 6.7 W/m 2 of primary mirror. We compare the current results to previous solar side-pumped laser experiments, including experiments at higher pumping density but with low collection efficiency. Finally, we present a scaled up design for a 400 W laser pumped by a solar collection area of 60 m 2, incorporating simultaneously high collection efficiency and high pumping density.

Summary of a study to determine low-velocity impact damage and residual tension strength for a thick graphite/epoxy motor case

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.

1990-01-01

Impacters of various shapes and masses were dropped from various heights onto 36 mm (1.4 in.) thick graphite/epoxy cylinders, which represented filament wound cases (FWC) for the booster motors of the Space Shuttle. Insert solid propellant was cast into some of the cylinders. The cylinders were impacted numerous times around the circumference and then cut into 51 mm (2.0 in.) wide tension specimens, each containing an impact site. Four indenters were used: a sharp corner, two hemispheres, and a bolt-like rod. The diameters of the hemispheres were 12.7 mm mm (0.5 in.) and 25.4 mm (1.0 in.), and the diameter of the rod was 6.3 mm (0.25 in.). Impacts with the rod were simulated by pressing the rod against the face of specimens. For the hemispheres, the damage initiated beneath the surface at a critical contact pressure and was not visible on the surface until an even larger pressure was exceeded. The damage consisted of matrix cracking and broken fiber. The rod an corner made visible surface damage in all tests. For the hemispheres, the tension strength was reduced considerably before the damage was visible on the surface, 30 percent for the 25.4 mm (1.0 in.) diameter hemisphere and 10 percent for the 12.7 mm (0.5 in.) diameter hemisphere. Analytical methods were used to predict the damage and residual tension strength. A factor of safety to account for nonvisible damage was determined.

A Novel Ex Vivo Training Model for Acquiring Supermicrosurgical Skills Using a Chicken Leg.

PubMed

Cifuentes, Ignacio J; Rodriguez, José R; Yañez, Ricardo A; Salisbury, María C; Cuadra, Álvaro J; Varas, Julian E; Dagnino, Bruno L

2016-11-01

Background  Supermicrosurgery is a technique used for dissection and anastomosis of submillimeter diameter vessels. This technique requires precise hand movements and superb eye-hand coordination, making continuous training necessary. Biological in vivo and ex vivo models have been described for this purpose, the latter being more accessible and cost-effective. The aim of this study is to present a new ex vivo training model using a chicken leg. Methods  In 28 chicken legs, an anatomical study was performed. An intramuscular perforator vessel was identified and dissected. Arterial diameters of 0.7, 0.5, and 0.3 mm were identified and consistency of the perforator was assessed. In additional 10 chicken legs, 25 submillimeter arteries were anastomosed using this perforator vessel. Five arteries of 0.3 and 10 of 0.5 mm were anastomosed with nylon 11-0 and 12-0 sutures. Intravascular stent (IVaS) technique and open guide (OG) technique were used in 0.5-mm arteries. A total of 10 arteries of 0.7 mm were anastomosed using 10-0 sutures in a conventional fashion. Dissection and anastomosis time were recorded and patency was tested. Results  We were able to identify 0.7 to 0.3 mm diameter arteries in all the specimens and confirm the consistency of the perforator. The median time for dissection was 13.4 minutes. The median time for anastomosis was 32.3 minutes for 0.3-mm arteries, 24.3 minutes for 0.5-mm arteries using IVaS, 29.5 minutes for the OG technique, and 20.9 minutes for the 0.7 mm diameter arteries. All the anastomoses were permeable. Conclusion  Due to its consistent and adequate diameter vessels, this model is adequate for training supermicrosurgical skills. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A newly designed big cup nitinol stent for gastric outlet obstruction

PubMed Central

Shi, Ding; Liao, Sheng-Hui; Geng, Jian-Ping

2010-01-01

AIM: To find out whether a newly designed big cup nitinol stent is suitable for treatment of patients with gastric outlet obstruction resulting from gastric cancer. METHODS: The new stent is composed of a proximal big cup segment (20 mm in length and 48-55 mm in diameter), a middle part (60 mm in length and 20 mm in diameter) covered by a polyethylene membrane and a distal sphericity (20 mm in length and 28 mm in diameter). Half of the proximal big cup segment is also covered by a polyethlene membrane, which is adjacent to the middle part of the stent. The stent is preloaded in a 6.0-mm-diameter introducer system. Thirteen patients with gastric outlet obstruction resulting from gastric cancer received the new stents under endoscopic and fluoroscopic guidance. RESULTS: Technical success was achieved in 12 of 13 (92.3%) patients. Among the 12 patients in whom endoscopic stent was placed successfully, the clinical success rate was 91.7% during a follow-up of average 6.5 mo. During the first month follow-up, the migration rate was 0%, recurrent obstruction 0% and gastric bleeding 8.3%. During the follow-up between 2-12 mo, no migration, recurrent obstruction and gastric bleeding occurred. CONCLUSION: The proximal big cup segment seems to be effective and promising for technical efficacy, clinical outcome, and preventing migration and tumor ingrowth and increasing the emptying rate of sinus ventriculi. PMID:20806440

Risk factors associated with delayed gastric emptying after subtotal gastrectomy with Billroth-I anastomosis using circular stapler for early gastric cancer patients.

PubMed

Kim, Ki Han; Kim, Min Chan; Jung, Ghap Joong

2012-11-01

Gastric surgery may potentiate delayed gastric emptying. Billroth I gastroduodenostomy using a circular stapler is the most preferable reconstruction method. The purpose of this study is to analyze the risk factors associated with delayed gastric emptying after radical subtotal gastrectomy with Billroth I anastomosis using a stapler for early gastric cancer. Three hundred and seventy-eight patients who underwent circular stapled Billroth I gastroduodenostomy after subtotal gastrectomy due to early gastric cancer were analyzed retrospectively. One hundred and eighty-two patients had Billroth I anastomosis using a 25 mm diameter circular stapler, and 196 patients had anastomosis with a 28 or 29 mm diameter circular stapler. Clinicopathological features and postoperative outcomes were evaluated and compared between the two groups. Delayed gastric emptying was diagnosed by symptoms and simple abdomen X-ray with or without upper gastrointestinal series or endoscopy. Postoperative delayed gastric emptying was found in 12 (3.2%) of the 378 patients. Among all the variables, distal margin and circular stapler diameter were significantly different between the cases with delayed gastric emptying and no delayed gastric emptying. There were statistically significant differences in sex, body mass index, comorbidity, complication, and operation type according to circular stapler diameter. In both univariate and multivariate logistic regression analyses, only the stapler diameter was found to be a significant factor affecting delayed gastric emptying (P = 0.040). In this study, the circular stapler diameter was one of the most significant predictable factors of delayed gastric emptying for Billroth I gastroduodenostomy. The use of a 28 or 29 mm diameter circular stapler rather than a 25 mm diameter stapler in stapled gastroduodenostomy for early gastric cancer can reduce postoperative delayed gastric emptying associated with anastomosic stenosis or edema with relative safety.

Generation of uniform light by use of diode lasers and a truncated paraboloid with a Lambertian scatterer.

PubMed

Alahautala, Taito; Hernberg, Rolf

2004-02-01

Uniform illumination was generated by use of a large number of diode laser emitters and a single nonimaging paraboloid with a Lambertian scatterer in the truncation plane. Laser light traverses a path toward the Lambertian surface and back by total internal reflection. An overall efficiency of 69% was demonstrated. Improvements that would increase the efficiency to more than 85% are suggested. The illuminated area is circular, with 14-mm diameter. The spatial nonuniformity of the beam profile is less than +/- 2%.

Feature extraction in MFL signals of machined defects in steel tubes

NASA Astrophysics Data System (ADS)

Perazzo, R.; Pignotti, A.; Reich, S.; Stickar, P.

2001-04-01

Thirty defects of various shapes were machined on the external and internal wall surfaces of a 177 mm diameter ferromagnetic steel pipe. MFL signals were digitized and recorded at a frequency of 4 Khz. Various magnetizing currents and relative tube-probe velocities of the order of 2m/s were used. The identification of the location of the defect by a principal component/neural network analysis of the signal is shown to be more effective than the standard procedure of classification based on the average signal frequency.

Electrical and Structural Characterization of Web Dendrite Crystals

NASA Technical Reports Server (NTRS)

Schwuttke, G. H.; Koliwad, K.; Dumas, K. A.

1985-01-01

Minority carrier lifetime distributions in silicon web dendrites are measured. Emphasis is placed on measuring areal homogeneity of lifetime, show its dependency on structural defects, and its unique change during hot processing. The internal gettering action of defect layers present in web crystals and their relation to minority carrier lifetime distributions is discussed. Minority carrier lifetime maps of web dendrites obtained before and after high temperature heat treatment are compared to similar maps obtained from 100 mm diameter Czochralski silicon wafers. Such maps indicate similar or superior areal homogeneity of minority carrier lifetime in webs.

The New Dual-beam Spectropluviometer Concept

NASA Astrophysics Data System (ADS)

Delahaye, J. Y.; Barthes, L.; Golé, P.; Lavergnat, J.; Vinson, J. P.

A Dual Beam Spectropluviometer (DBS) measuring the equivalent diameter D, the vertical velocity V and the time T of arrival of particles is presented. Its main advan- tage over previous optical disdrometers is the extensive measurement range of atmo- spheric precipitations near ground. In particular, 0.15 mm diameter particles can be observed in quiet laboratory conditions and 0.2 mm is the smallest diameter observed in the outdoor turbulent air velocity field. The means for obtaining such results are (i) two uniform beams of rectangular cross-section 2 mm in height, 40 mm in width and 250 mm in length, with a 2 mm vertical gap, (ii) a dual 16-bit analog to digital converter, (iii) a dedicated program for extracting the 3 parameters in real time by computing the signal slopes and determining the correlation between both channels, (iii) various means for reducing splashing and vibration. Laboratory tests and typical rain measurements are shown. The DBS is particularly suited for extensive atmospheric and radio propagation research applications where the smallest drops were not correctly estimated in the distributions because of the lack of appropriate measurement devices.

Dimensions of stabident intraosseous perforators and needles.

PubMed

Ramlee, R A; Whitworth, J

2001-09-01

Problems can be encountered inserting intraosseous injection needles through perforation sites. This in vitro study examined the variability and size compatibility of Stabident intraosseous injection components. The diameters of 40 needles and perforators from a single Stabident kit were measured in triplicate with a toolmakers microscope. One-way ANOVA revealed that mean needle diameter (0.411 mm) was significantly narrower than mean perforator diameter (0.427 mm) (p < 0.001). A frequency distribution plot revealed that needle diameter followed a normal distribution, indicating tight quality control during manufacture. The diameter of perforators was haphazardly distributed, with a clustering of 15% at the lower limit of the size range. However on no occasion was the diameter of a perforator smaller than that of an injection needle. We conclude that components of the Stabident intraosseous anaesthetic system are size-compatible, but there is greater and more haphazard variability in the diameter of perforators than injection needles.

Retrospective cohort clinical investigation of a dental implant with a narrow diameter and short length for the partial rehabilitation of extremely atrophic jaws.

PubMed

Maló, Paulo S; de Araújo Nobre, Miguel A; Lopes, Armando V; Ferro, Ana S

2017-01-01

We investigated the short-term clinical outcomes of narrow-diameter short-length implants for the fixed-prosthetic partial rehabilitation of extremely resorbed jaws. Twenty-three patients requiring partial rehabilitations with narrow-platform short-length implants in any jaw were included in this study. In total, 30 implants 3.3 mm in diameter and 7 (n = 15 implants) or 8.5 (n = 15 implants) mm in length were inserted. The primary outcome measure was implant cumulative survival rate (CSR); the secondary outcome measures were marginal bone resorption at 1 and 3 years and the incidence of biologic and mechanical complications. Five patients (21.7%) with six implants (20%) were lost to follow-up. Two implants failed in two patients, yielding a CSR at 3 years of follow-up of 93.4%. The average (standard deviation) marginal bone resorption was 1.34 mm (0.95 mm) after the first year and 1.38 mm (0.78 mm) after the third year. Biologic complications occurred in three patients; mechanical complications occurred in three patients. Despite the limitations of the study, our findings show that the use of new narrow-diameter short-length implants for the rehabilitation of extremely atrophic regions is viable in the short-term, and can be considered a treatment alternative in extremely resorbed jaws.

Ultra-Compact Multitip Scanning Probe Microscope with an Outer Diameter of 50 mm

NASA Astrophysics Data System (ADS)

Cherepanov, Vasily; Zubkov, Evgeny; Junker, Hubertus; Korte, Stefan; Blab, Marcus; Coenen, Peter; Voigtländer, Bert

We present a multitip scanning tunneling microscope (STM) where four independent STM units are integrated on a diameter of 50 mm. The coarse positioning of the tips is done under the control of an optical microscope or an SEM in vacuum. The heart of this STM is a new type of piezoelectric coarse approach called Koala Drive which can have a diameter greater than 2.5 mm and a length smaller than 10 mm. Alternating movements of springs move a central tube which holds the STM tip or AFM sensor. This new operating principle provides a smooth travel sequence and avoids shaking which is intrinsically present for nanopositioners based on inertial motion with saw tooth driving signals. Inserting the Koala Drive in a piezo tube for xyz-scanning integrates a complete STM inside a 4 mm outer diameter piezo tube of <10 mm length. The use of the Koala Drive makes the scanning probe microscopy design ultra-compact and accordingly leads to a high mechanical stability. The drive is UHV, low temperature, and magnetic field compatible. The compactness of the Koala Drive allows building a four-tip STM as small as a single-tip STM with a drift of <0.2 nm/min and lowest resonance frequencies of 2.5 (xy) and 5.5 kHz (z). We present examples of the performance of the multitip STM designed using the Koala Drive.

Effects of tool handle dimension and workpiece orientation and size on wrist ulnar/radial torque strength, usability and discomfort in a wrench task.

PubMed

Dianat, Iman; Rahimi, Soleyman; Nedaei, Moein; Asghari Jafarabadi, Mohammad; Oskouei, Ali E

2017-03-01

The effects of tool handle dimension (three modified designs of wrenches with 30-50 mm diameter cylindrical handles and traditional design with rectangular cross-sectional (5 mm × 25 mm) handle), workpiece orientation (vertical/horizontal) and workpiece size (small/large) as well as user's hand size on wrist ulnar/radial (U/R) torque strength, usability and discomfort, and also the relationship between these variables were evaluated in a maximum torque task using wrenches. The highest and lowest levels of maximal wrist U/R torque strength were recorded for the 30 mm diameter handle and traditional wrench design, respectively. The prototype handle with 30 mm diameter, together with 40 mm diameter handle, was also better than other designs as they received higher usability ratings and caused less discomfort. The mean wrist torque strength exerted on a vertically oriented workpiece (in the sagittal plane) was 23.8% higher than that exerted on a horizontally oriented one (in the transverse plane). The user's hand size had no effect on torque exertions. The wrist torque strength and usability were negatively correlated with hand and finger discomfort ratings. The results are also discussed in terms of their implications for hand tool and workstation configuration in torque tasks involving wrenches. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ability of the Confined Explosive Component Water Gap Test STANAG 4363 to Assess the Shock Sensitivity of MM-Scale Detonators

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

Lefrancois, A S; Roeske, F; Benterou, J

2006-02-10

The Explosive Component Water Gap Test (ECWGT) has been validated to assess the shock sensitivity of lead and booster components having a diameter larger than 5 mm. Several countries have investigated by experiments and numerical simulations the effect of confinement on the go/no go threshold for Pentaerythritol Tetranitrate (PETN) pellets having a height and diameter of 3 mm, confined by a steel annulus of wall thickness 1-3.5 mm. Confinement of the PETN by a steel annulus of the same height of the pellet with 1-mm wall thickness makes the component more sensitive (larger gap). As the wall thickness is increasedmore » to 2-mm, the gap increases a lesser amount, but when the wall thickness is increased to 3.5-mm a decrease in sensitivity is observed (smaller gap). This decrease of the water gap has been reproduced experimentally. Recent numerical simulations using Ignition and Growth model [1] for the PETN Pellet have reproduced the experimental results for the steel confinement up to 2 mm thick [2]. The presence of a stronger re-shock following the first input shock from the water and focusing on the axis have been identified in the pellet due to the steel confinement. The double shock configuration is well-known to lead in some cases to shock desensitization. This work presents the numerical simulations using Ignition and Growth model for LX16 (PETN based HE) and LX19 (CL20 based HE) Pellets [3] in order to assess the shock sensitivity of mm-scale detonators. The pellets are 0.6 mm in diameter and 3 mm length with different type of steel confinement 2.2 mm thick and 4.7 mm thick. The influence of an aluminum confinement is calculated for the standard LX 16 pellet 3 mm in diameter and 3 mm in height. The question of reducing the size of the donor charge is also investigated to small scale the test itself.« less

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

Woloshun, Keith Albert; Dale, Gregory E.; Olivas, Eric Richard

The Northstar target for Mo99 production is made up of Mo100 disks in a stack separated by coolant gaps for helium flow. A number of targets have been tested at ANL for both production of Mo99 and for thermal-hydraulic performance. These have all been with a 12 mm diameter target, even while the production goals have increased the diameter to now 29 mm. A 29 mm diameter target has been designed that is consistent with the ANL beam capabilities and the capabilities of the helium circulation system currently in use at ANL. This target is designed for 500 μA atmore » 35 MeV electrons. While the plant design calls for 42 MeV, the chosen design point is more favorable and higher power given the limits of the ANL accelerator. The intended beam spot size is 12 mm FWHM, but the thermal analysis presented herein conservatively assumed a 10 mm FWHM beam, which results in a 44% higher beam current density at beam center.« less

Role of Plasma Temperature and Residence Time in Stagnation Plasma Synthesis of c-BN Nanopowders

DTIC Science & Technology

2013-01-01

outer diameter of 15mm. A center injection 19 nozzle of 1.4mm diameter is implemented for precursor introduction. Plasma and sheath gas ... Gas Phase Synthesis of Nanoparticles..................................................... 5 2.2 Cubic Boron Nitride Synthesis...11 2.2.4 Effects of gas composition ............................................................................................ 11

Thermocouple design for measuring temperatures of small insects

Treesearch

A.A. Hanson; R.C. Venette

2013-01-01

Contact thermocouples often are used to measure surface body temperature changes of insects during cold exposure. However, small temperature changes of minute insects can be difficult to detect, particularly during the measurement of supercooling points. We developed two thermocouple designs, which use 0.51 mm diameter or 0.127 mm diameter copper-constantan wires, to...

7 CFR 51.784 - Classification of defects.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS) United States Standards for Grades of Florida Grapefruit Definitions § 51.784 Classification of... discoloration permitted in the grade Very deep or very rough aggregating more than a circle 1/2 inch (12.7 mm) in diameter; deep or rough aggregating more than a circle 1 inch (25.4 mm) in diameter; slightly...

7 CFR 51.1837 - Classification of defects.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS) United States Standards for Grades of Florida Tangerines Definitions § 51.1837 Classification of....1828.] Deep or rough aggregating more than a circle 1/4 inch (6.4 mm) in diameter; slightly rough with... slight depth aggregating more than a circle 11/8 inches (28.6 mm) in diameter Deep or rough aggregating...

A thin gold coated hydrogen heat pipe-cryogenic target for external experiments at COSY

NASA Astrophysics Data System (ADS)

Abdel-Bary, M.; Abdel-Samad, S.; Elawadi, G. A.; Kilian, K.; Ritman, J.

2009-05-01

A gravity assisted Gold coated heat pipe (GCHP) with 5-mm diameter has been developed and tested to cool a liquid hydrogen target for external beam experiments at COSY. The need for a narrow target diameter leads us to study the effect of reducing the heat pipe diameter to 5 mm instead of 7 mm, to study the effect of coating the external surface of the heat pipe by a shiny gold layer (to decrease the radiation heat load), and to study the effect of using the heat pipe without using 20 layers of' super-insulation around it (aluminized Mylar foil) to keep the target diameter as small as possible. The developed gold coated heat pipe was tested with 20 layers of super-insulation (WI) and without super-insulation (WOI). The operating characteristics for both conditions were compared to show the advantages and disadvantages.

Ion extraction capabilities of closely spaced grids

NASA Technical Reports Server (NTRS)

Rovang, D. C.; Wilbur, P. J.

1982-01-01

The ion extraction capabilities of accelerator systems with small screen hole diameters (less than 2.0 mm) are investigated at net-accelerating voltages of 100, 300, and 500 V. Results show that the impingement-limited perveance is not dramatically affected by reductions in screen hole diameter to 1.0 mm, but impingement-limited performance was found to be dependent on the grid separation distance, the discharge-to-total accelerating voltage ratio, and the net-to-total accelerating voltage ratio. Results obtained using small hole diameters and closely spaced grids indicate a new mode of grid operation where high current density operation can be achieved with a specified net acceleration voltage by operating the grids at a high rather than low net-to-total acceleration voltage. Beam current densities as high as 25 mA/sq cm were obtained using grids with 1.0 mm diameter holes operating at a net accelerating voltage of 500 V.

[Correlation between the width of lingual vein and the changes of hemodynamics of portal system in patients with primary liver cancer].

PubMed

Yue, Xiao-Qiang; Gao, Jing-Dong; Zhai, Xiao-Feng; Liu, Qing; Jiang, Dong; Ling, Chang-Quan

2006-09-01

To explore the correlation between the width of lingual varix and changes of hemodynamics of portal system in patients with primary liver cancer so as to supply the data for the forecast of portal hypertension by observing lingual varix. The diameter of lingual vein (Dlv) was measured by vernier caliper as dependent variable, and the diameters and indexes of hemodynamics of portal vessels were measured by Doppler as independent variables, then a multipe stepwise analysis was performed. The diameters of portal vein (Dpv) and splenic vein (Dsv) entered the formula Dlv (mm) = 0.185 + 0.311 Dsv (mm) + 0.236 Dpv (mm) when the entry and removal values were alpha(in)=0.10 and alpha(out)=0.15, respectively. The width of lingual vein is closely correlated with the diameters of portal vein and splenic vein in patients with primary liver cancer.

Importance of filament diameter when using bass brushing technique.

PubMed

Vowles, A D; Wade, A B

1977-08-01

A comparative study using a crossover experimental construction was made of the effectiveness of brushes containing 6/10 nylon filaments of 0.132 mm mean diameter using a Bass technique with those containing filaments of the same type of nylon but 0.280 mm diameter. Each type of brush was used for a 2-week period. Even though the finer filament brushes contained more than three times as many filaments, they were inferior in cleaning achievement to the brushes with the broader filaments. The difference was particularly marked on the facial aspect, but was largely nullified lingually. The effectiveness of the Bass technique in the gingival zone demonstrated in a previous investigation when brushes containing filaments of 0.18 and 0.20 mm were used, was not found in this investigation. It is concluded that filament diameter is critical in achieving effective cleaning using the Bass technique.

Unconstrained tripolar hip implants: effect on hip stability.

PubMed

Guyen, Olivier; Chen, Qing Shan; Bejui-Hugues, Jacques; Berry, Daniel J; An, Kai-Nan

2007-02-01

Tripolar implants were developed to treat unstable total hip arthroplasties. However, there is limited confirmation that they achieve this purpose despite their increasing use. Because they have a larger effective head size, these implants are expected to increase range of motion to impingement and improve stability in situations at risk for impingement compared with conventional implants. We assessed the range of motion to impingement using a tripolar implant mounted to an automated hip simulator using 22.2-mm and 28-mm femoral head sizes. The 22 and 28-mm tripolar implants provided increases of 30.5 degrees in flexion, 15.4 degrees in adduction, and 22.4 degrees in external rotation compared with the conventional 22.2-mm femoral head diameter implant. At the critical position of 90 degrees hip flexion, there was an increase of 45.2 degrees in internal rotation. At 0 degrees and 30 degrees external rotation, extension increases were 18.8 degrees and 7.8 degrees, respectively. Bony impingement was the limiting factor. Tripolar implants increased the arc of motion before impingement in positions at risk for dislocation and are expected to provide greater stability.

Design, Development and Testing of Inconel Alloy IN718 Spherical Gas Bottle for Oxygen Storage

NASA Astrophysics Data System (ADS)

Chenna Krishna, S.; Agilan, M.; Sudarshan Rao, G.; Singh, Satish Kumar; Narayana Murty, S. V. S.; Venkata Narayana, Ganji; Beena, A. P.; Rajesh, L.; Jha, Abhay K.; Pant, Bhanu

2017-11-01

This paper describes the details of design, manufacture and testing of 200 mm diameter spherical gas bottle of Inconel 718 (IN718) with nominal wall thickness of 2.3 mm. Gas bottle was designed for the specified internal pressure loading with a thickness of 2.9 mm at the circumferential weld which was brought down to 2.3 mm at the membrane locations. Hemispherical forgings produced through closed-die hammer forging were machined and electron beam welded to produce a spherical gas bottle. Duly welded gas bottle was subjected to standard aging treatment to achieve the required tensile strength. Aged gas bottle was inspected for dimensions and other stringent quality requirements using various nondestructive testing techniques. After inspection, gas bottle was subjected to pressure test for maximum expected operating pressure and proof pressure of 25 and 37.5 MPa, respectively. Strain gauges were bonded at different locations on the gas bottle to monitor the strains during the pressure test and correlated with the predicted values. The predicted strain matched well with the experimental strain confirming the design and structural integrity.

Sodium chloride crystallization from thin liquid sheets, thick layers, and sessile drops in microgravity

NASA Astrophysics Data System (ADS)

Fontana, Pietro; Pettit, Donald; Cristoforetti, Samantha

2015-10-01

Crystallization from aqueous sodium chloride solutions as thin liquid sheets, 0.2-0.7 mm thick, with two free surfaces supported by a wire frame, thick liquid layers, 4-6 mm thick, with two free surfaces supported by metal frame, and hemispherical sessile drops, 20-32 mm diameter, supported by a flat polycarbonate surface or an initially flat gelatin film, were carried out under microgravity on the International Space Station (ISS). Different crystal morphologies resulted based on the fluid geometry: tabular hoppers, hopper cubes, circular [111]-oriented crystals, and dendrites. The addition of polyethylene glycol (PEG-3350) inhibited the hopper growth resulting in flat-faced surfaces. In sessile drops, 1-4 mm tabular hopper crystals formed on the free surface and moved to the fixed contact line at the support (polycarbonate or gelatin) self-assembling into a shell. Ring formation created by sessile drop evaporation to dryness was observed but with crystals 100 times larger than particles in terrestrially formed coffee rings. No hopper pyramids formed. By choosing solution geometries offered by microgravity, we found it was possible to selectively grow crystals of preferred morphologies.

Efficacy and economic impact evaluation of a navigation system for assisted lung biopsy

PubMed Central

Giannatiempo, Sara; Petitti, Tommasangelo; Zobel, Bruno B.; Grasso, Rosario F.; Guglielmelli, Eugenio

2018-01-01

This Letter reports on the testing and assessment of an optical computed tomography-navigation system for percutaneous lung interventional, SIRIO, showing how the lesion diameter affects the bioptic procedure. Clinical data, relating to 501 patients, were collected at the Department of Interventional Radiology of Policlinico Universitario Campus Bio-Medico. This Letter shows that the diameter of lesion affects only the procedure duration (50.91 ± 18.87 min for lesions of diameter ≤20 mm and 44.98 ± 19.43 min for lesions of diameter >20 and ≤40 mm). For the nodules with a diameter ≤20 mm, there is a significant increase in the duration of the procedure (for each mm less the time increases by 6 s). Other parameters like the mean effective radiation dose and the presence of a diagnostic or non-diagnostic specimen do not depend, instead, on the lesion size. The economic analysis based on the biopsy procedure with SIRIO shows the necessity to adopt a new reimbursement system for percutaneous biopsy performed using navigation systems to stimulate their use to get important non-economic gains such as early diagnosis, reduction of the absorbed dose of X-rays and increasing number of lung cancers in a curable early stage. PMID:29750112

Efficacy and economic impact evaluation of a navigation system for assisted lung biopsy.

PubMed

Giannatiempo, Sara; Carpino, Giorgio; Petitti, Tommasangelo; Zobel, Bruno B; Grasso, Rosario F; Guglielmelli, Eugenio

2018-04-01

This Letter reports on the testing and assessment of an optical computed tomography-navigation system for percutaneous lung interventional, SIRIO, showing how the lesion diameter affects the bioptic procedure. Clinical data, relating to 501 patients, were collected at the Department of Interventional Radiology of Policlinico Universitario Campus Bio-Medico. This Letter shows that the diameter of lesion affects only the procedure duration (50.91 ± 18.87 min for lesions of diameter ≤20 mm and 44.98 ± 19.43 min for lesions of diameter >20 and ≤40 mm). For the nodules with a diameter ≤20 mm, there is a significant increase in the duration of the procedure (for each mm less the time increases by 6 s). Other parameters like the mean effective radiation dose and the presence of a diagnostic or non-diagnostic specimen do not depend, instead, on the lesion size. The economic analysis based on the biopsy procedure with SIRIO shows the necessity to adopt a new reimbursement system for percutaneous biopsy performed using navigation systems to stimulate their use to get important non-economic gains such as early diagnosis, reduction of the absorbed dose of X-rays and increasing number of lung cancers in a curable early stage.

CFD-DEM modeling the effect of column size and bed height on minimum fluidization velocity in micro fluidized beds with Geldart B particles

DOE PAGES

Xu, Yupeng; Li, Tingwen; Musser, Jordan; ...

2017-06-07

The fluidization behavior of Geldart B particles in micro fluidized beds is investigated numerically using Computational Fluid Dynamics coupled with Discrete Element Method (CFD-DEM) available in the open-source Multiphase Flow with Interphase eXchanges (MFIX) code. The effects of different bed inner diameters (D) of 8 mm, 12 mm, 16 mm and various initial static bed heights (H) were examined. It is found that both decreasing the column diameter and increasing the bed height in a micro fluidized bed increases the minimum fluidization velocity (Umf). The observed overshoot in pressure drop that occurs before the onset of fluidization decreases in magnitudemore » with increasing column diameter, however there is less sensitivity to bed height. Overall, the numerical results agree qualitatively with existing theoretical correlations and experimental studies. The simulations show that both column diameter and particle-wall friction contribute to the variation in minimum fluidization velocity. Finally, these two factors are coupled and hard to separate. The detailed influences of wall friction on minimum fluidization velocity are then investigated for a prescribed column diameter of 8 mm by varying the wall friction from 0 to 0.4.« less

Effects of body conformation and udder morphology on milk yield of zebu cows in North region of Cameroon

PubMed Central

Mingoas, Kilekoung Jean-Pierre; Awah-Ndukum, Julius; Dakyang, Houinga; Zoli, Pagnah André

2017-01-01

Aim: The aim of the study was to assess the effect of udder morphological characteristics on milk yield in zebu cows of Cameroon. Materials and Methods: The diameter and height of the udder, length and diameter of the teat, and the milk yield were measured in 29 Djafun (Red Mbororo) and 19 Aku (White Fulani) cows in Louggueré zootechnical station in the North region of Cameroon. Results: Overall, strong positive correlation (rp=0.60) between the diameter (240.21±28.58 mm) and height (131.12±23.64 mm) of udders (p<0.001) and between length (39.51±6.44 mm) and diameter (19.85±3.08 mm) of teats (rp=0.78) were found in the zebu cows. Udder morphologic characteristics varied significantly (p<0.005) according to breed, lactation stage and parity, and height at whiters. There was significant (p<0.001) correlations between udder diameter (rp=0.541) and height (rp=0.549) with milk yield. Conclusion: This study ascertained udder morphological characteristics values in local zebu cows, and showed that udder size is strong and positively correlated to milk yield. The findings are useful in genetic improvement programs of zebu cows. PMID:28919680

CFD-DEM modeling the effect of column size and bed height on minimum fluidization velocity in micro fluidized beds with Geldart B particles

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

Xu, Yupeng; Li, Tingwen; Musser, Jordan

The fluidization behavior of Geldart B particles in micro fluidized beds is investigated numerically using Computational Fluid Dynamics coupled with Discrete Element Method (CFD-DEM) available in the open-source Multiphase Flow with Interphase eXchanges (MFIX) code. The effects of different bed inner diameters (D) of 8 mm, 12 mm, 16 mm and various initial static bed heights (H) were examined. It is found that both decreasing the column diameter and increasing the bed height in a micro fluidized bed increases the minimum fluidization velocity (Umf). The observed overshoot in pressure drop that occurs before the onset of fluidization decreases in magnitudemore » with increasing column diameter, however there is less sensitivity to bed height. Overall, the numerical results agree qualitatively with existing theoretical correlations and experimental studies. The simulations show that both column diameter and particle-wall friction contribute to the variation in minimum fluidization velocity. Finally, these two factors are coupled and hard to separate. The detailed influences of wall friction on minimum fluidization velocity are then investigated for a prescribed column diameter of 8 mm by varying the wall friction from 0 to 0.4.« less

The longest wheal diameter is the optimal measurement for the evaluation of skin prick tests.

PubMed

Konstantinou, George N; Bousquet, Philippe-Jean; Zuberbier, Torsten; Papadopoulos, Nikolaos G

2010-01-01

Mean diameter or longest diameter are the 2 most frequently used parameters for wheal response assessment after skin prick testing (SPT). We aimed to compare these 2 parameters taking as gold standard the surface of the wheal skin response. Patients suspected of having an allergic reaction against inhalant allergens have been skin prick tested using the Pan-European GA(2)LEN SPT panel. Fifteen minutes later, macroscopically evident wheal and flare reactions were marked with a pen and transferred to paper with a transparent scotch tape. Each paper-transferred wheal was scanned with an ordinary scanner, and its surface-corresponding maximum perpendicular diameters and longest diameters were measured using a computer software application for image recognition, developed for this purpose. Correlation coefficients (Spearman's rho) between surfaces and respective mean (rho(mean)) or longest (rho(longest)) diameters were calculated and subsequently compared. 1,554 SPTs were performed in 74 patients. In 264, a macroscopically evident wheal and flare response was observed. Both mean and longest diameters correlated significantly with the wheal surfaces. However, rho(longest) was statistically significantly larger than rho(mean) when the surface of the wheal was >17 mm(2) (rho(longest) > 0.860 vs. rho(mean) < 0.660; p < 0.05).Such a surface corresponds to a maximum diameter of approximately 7 mm and a mean diameter of approximately 6 mm. Thus, the larger the surface of the wheal, the more appropriate the usage of the longest diameter. The longest wheal diameter alone seems to be a better surrogate marker of the wheal surface in comparison with the mean diameter. In addition, it is easier and faster to measure. Therefore, we propose this as the optimal methodology to evaluate SPTs. 2009 S. Karger AG, Basel.

Undercooling Behavior and Intermetallic Compound Coalescence in Microscale Sn-3.0Ag-0.5Cu Solder Balls and Sn-3.0Ag-0.5Cu/Cu Joints

NASA Astrophysics Data System (ADS)

Zhou, M. B.; Ma, X.; Zhang, X. P.

2012-11-01

The microstructure of microscale solder interconnects and soldering defects have long been known to have a significant influence on the reliability of electronic packaging, and both are directly related to the solidification behavior of the undercooled solder. In this study, the undercooling behavior and solidification microstructural evolution of Sn-3.0Ag-0.5Cu solder balls with different diameters (0.76 mm, 0.50 mm, and 0.30 mm) and the joints formed by soldering these balls on Cu open pads of two diameters (0.48 mm and 0.32 mm) on a printed circuit board (PCB) substrate were characterized by differential scanning calorimetry (DSC) incorporated into the reflow process. Results show that the decrease in diameter of the solder balls leads to an obvious increase in the undercooling of the balls, while the undercooling of the solder joints shows a dependence on both the diameter of the solder balls and the diameter ratio of solder ball to Cu pad (i.e., D s/ D p), and the diameter of the solder balls has a stronger influence on the undercooling of the joints than the dimension of the Cu pad. Coarse primary intermetallic compound (IMC) solidification phases were formed in the smaller solder balls and joints. The bulk Ag3Sn IMC is the primary solidification phase in the as-reflowed solder balls. Due to the interfacial reaction and dissolution of Cu atoms into the solder matrix, the primary Ag3Sn phase can be suppressed and the bulk Cu6Sn5 IMC is the only primary solidification phase in the as-reflowed solder joints.

Racial Differences in Left Atrial Size: Results from the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

PubMed

Dewland, Thomas A; Bibbins-Domingo, Kirsten; Lin, Feng; Vittinghoff, Eric; Foster, Elyse; Ogunyankin, Kofo O; Lima, Joao A; Jacobs, David R; Hu, Donglei; Burchard, Esteban G; Marcus, Gregory M

2016-01-01

Whites have an increased risk of atrial fibrillation (AF) compared to Blacks. The mechanism underlying this association is unknown. Left atrial (LA) size is an important AF risk factor, and studies in older adults suggest Whites have larger LA diameters. However, because AF itself causes LA dilation, LA size differences may be due to greater subclinical AF among older Whites. We therefore assessed for racial differences in LA size among young adults at low AF risk. The Coronary Artery Risk Development in Young Adults (CARDIA) study enrolled White and Black participants between 18 and 30 years of age. LA diameter was measured in a subset of participants using echocardiography at Year 5 (n = 4,201) and Year 25 (n = 3,373) of follow up. LA volume was also assessed at Year 5 (n = 2,489). Multivariate linear regression models were used to determine the adjusted association between race and LA size. In unadjusted analyses, mean LA diameter was significantly larger among Blacks compared to Whites both at Year 5 (35.5 ± 4.8 mm versus 35.1 ± 4.5 mm, p = 0.01) and Year 25 (37.4 ± 5.1 mm versus 36.8 ± 4.9 mm, p = 0.002). After adjusting for demographics, comorbidities, and echocardiographic parameters, Whites demonstrated an increased LA diameter (0.7 mm larger at Year 5, 95% CI 0.3-1.1, p<0.001; 0.6 mm larger at Year 25, 95% CI 0.3-1.0, p<0.001). There was no significant association between race and adjusted Year 5 LA volume. In conclusion, in a young, well-characterized cohort, the larger adjusted LA diameter among White participants suggests inherent differences in atrial structure may partially explain the higher risk of AF in Whites. The incongruent associations between race, LA diameter, and LA volume suggest that LA geometry, rather than size alone, may have implications for AF risk.

Consideration of growth (age)-related effects on globe size and corneal thickness in ovine eyes for use in laboratory studies.

PubMed

Doughty, Michael J

2017-07-01

The aim was to assess differences in eyeball mass, corneal diameter and central corneal thickness in slaughterhouse-procured ovine eyes. Over a 12-year period, measurements of eye globe mass, horizontal corneal diameter and central corneal thickness were routinely undertaken within two hours post-mortem. Only eyes free of obvious mechanical damage or disease were used. From measurements on 736 quality-selected and trimmed eyes, globe wet mass ranged from 10.4 to 25.2 g, horizontal corneal diameter from 19.0 to 26.5 mm and central corneal thickness measured by ultrasonic pachymetry from 0.543 to 0.836 mm (with an overall average of 690 ± 0.056 mm). The ocular globe mass was strongly correlated to horizontal corneal diameter (r 2  = 0.829). Central corneal thickness correlated with globe mass (r = 0.543) and to horizontal corneal diameter (r = 0.402). Based on the different anatomical measurements, a lamb's eye would be expected to have a thinner cornea (average 0.640 mm) than that of an adult outbred ewe (average 0.730 mm). In freshly procured eyes showing signs of slight corneal oedema, central corneal thickness was greater (average 0.856 ± 0.052 mm) and up to 24 hours of cold storage resulted in predictable increases in central corneal thickness of six to 24 per cent, especially in eyes showing signs of corneal oedema before storage. Based on the correlations obtained, differences in ovine eyes can be attributed to growth-related differences in the animals and thus, indirectly to their expected ages. A simple measure of the horizontal corneal diameter in ovine eyes used for laboratory studies would be a useful indicator in reporting these studies. © 2016 Optometry Australia.

Adapted preparation technique for screw-type implants: explorative in vitro pilot study in a porcine bone model.

PubMed

Beer, Andreas; Gahleitner, André; Holm, Anders; Birkfellner, Wolfgang; Homolka, Peter

2007-02-01

The aim of this study was to quantify the effect of adapted preparation on the insertion torque of self-tapping implants in cancellous bone. In adapted preparation, bone condensation - and thus, insertion torque - is controlled by changing the diameter of the drilling. After preparation of cancellous porcine vertebral bone with drills of 2.85, 3, 3.15 or 3.35 mm final diameters, Brånemark sytem Mk III implants (3.75 x 11.5 mm) were inserted in 141 sites. During implantation, the insertion torque was recorded. Prior to implant insertion, bone mineralization (bone mineral density (BMD)) was measured with dental quantative computed tomography. The BMD values measured at the implant position were correlated with insertion torque for varying bone condensation. Based on the average torque recorded during implant insertion into the pre-drilled canals with a diameter of 3 mm, torque increased by approximately 17% on reducing the diameter of the drill by 5% (to 2.85 mm). On increasing the diameter of the osteotomy to 3.15 mm (5%) or 3.35 mm (12%), torque values decreased by approximately 21% and 50%, respectively. The results demonstrate a correlation between primary stability (average insertion torque) and the diameter of the implant bed on using a screw-shaped implant. Thus, using an individualized bone mineralization-dependent drilling technique, optimized torque values could be achieved in all tested bone qualities with BMDs ranging from 330 to 500 mg/cm(3). The results indicate that using a bone-dependent drilling technique, higher torque values can also be achieved in poor bone using an individualized drilling resulting in higher bone condensation. As immediate function is dependent on primary stability (high insertion torque), this indicates that primary stability can be increased using a modified drilling technique in lesser mineralized bone.

Acoustic propulsion of nanorod motors inside living cells.

PubMed

Wang, Wei; Li, Sixing; Mair, Lamar; Ahmed, Suzanne; Huang, Tony Jun; Mallouk, Thomas E

2014-03-17

The ultrasonic propulsion of rod-shaped nanomotors inside living HeLa cells is demonstrated. These nanomotors (gold rods about 300 nm in diameter and about 3 mm long) attach strongly to the external surface of the cells, and are readily internalized by incubation with the cells for periods longer than 24 h. Once inside the cells, the nanorod motors can be activated by resonant ultrasound operating at 4 MHz, and show axial propulsion as well as spinning. The intracellular propulsion does not involve chemical fuels or high-power ultrasound and the HeLa cells remain viable. Ultrasonic propulsion of nanomotors may thus provide a new tool for probing the response of living cells to internal mechanical excitation, for controllably manipulating intracellular organelles, and for biomedical applications.

Device-less patent foramen ovale closure by radiofrequency thermal energy.

PubMed

Walpoth, Nazan B; Habermacher, Kathrin; Moarof, Igal; Watson, Sandy; Wahl, Andreas; Windecker, Stephan; Schönenberger, Christa; Meier, Bernhard

2008-02-23

The goal of this study was to assess the feasibility, safety and success of a system which uses radiofrequency energy (RFE) rather than a device for percutaneous closure of patent foramen ovale (PFO). Sixteen patients (10 men, 6 women, mean age 50 years) were included in the study. All of them had a proven PFO with documented right-to-left shunt (RLS) after Valsalva manoeuvre (VM) during transoesophageal echocardiography (TEE). The patients had an average PFO diameter of 6 +/- 2 mm at TEE and an average of 23 +/- 4 microembolic signals (MES) in power M-mode transcranial Doppler sonography (pm-TCD), measured over the middle cerebral artery. An atrial septal aneurysm (ASA) was present in 7 patients (44%). Balloon measurement, performed in all patients, revealed a stretched PFO diameter of 8 +/- 3 mm. In 2 patients (stretched diameter 11 and 14 mm respectively, both with ASA >10 mm), radiofrequency was not applied (PFO too large) and the PFO was closed with an Amplatzer PFO occluder instead. A 6-month follow-up TEE was performed in all patients. There were no serious adverse events during the procedure or at follow-up (12 months average). TEE 6 months after the first RFE procedure showed complete closure of the PFO in 50% of the patients (7/14). Closure appeared to be influenced by PFO diameter, complete closure being achieved in 89% (7/8) with a balloon-stretched diameter < or =7 mm but in none of the patients >7 mm. Only one of the complete closure patients had an ASA. Of the remainder, 4 (29%) had an ASA. Although the PFO was not completely closed in this group, some reduction in the diameter of the PFO and in MES was documented by TEE and pm-TCD with VM. Five of the 7 residual shunt patients received an Amplatzer PFO occluder. Except for one patient with a minimal residual shunt, all showed complete closure of PFO at 6-month follow-up TEE and pm-TCD with VM. The other two refused a closure device. The results confirm that radiofrequency closure of the PFO is safe albeit less efficacious and more complex than device closure. The technique in its current state should not be attempted in patients with a balloon-stretched PFO diameter >7 mm and an ASA.

Anatomy of vastus lateralis muscle flap.

PubMed

Tayfur, Volkan; Magden, Orhan; Edizer, Mete; Atabey, Atay

2010-11-01

A vastus lateralis muscle flap is used as a pedicled and free flap. In this study, the vastus lateralis muscles of 15 adult formalin-fixed cadavers (30 cases) were dissected. The dominant pedicle was found to be descending branch of the lateral circumflex femoral artery. The mean diameter of the artery was found to be 2.1 mm. This pedicle was located 119.4 mm distal to the pubic symphysis. The mean length of the major pedicle was found to be 56.8 mm when the dominant pedicle was chosen to nourish the flap. The dominant pedicle entered the muscle 155.8 and 213.7 mm from the greater trochanter and the anterior superior iliac spine, respectively. The muscle had proximal minor pedicles from the ascending and transverse branches of lateral circumflex femoral artery. These arteries had mean diameters of 1.8 and 2.0 mm, respectively. The distal minor branches were present in all of the dissections. The distal branch had a mean diameter of 1.8 mm. The origin of this distal branch was located 83.7 mm proximal to the intercondylar line. The motor nerve of the vastus lateralis was found to be originating from femoral nerve. The nerve entered the muscle 194.6 mm from the anterior superior iliac spine.

Three-dimensional relationship between high-order root-mean-square wavefront error, pupil diameter, and aging

PubMed Central

Applegate, Raymond A.; Donnelly, William J.; Marsack, Jason D.; Koenig, Darren E.; Pesudovs, Konrad

2007-01-01

We report root-mean-square (RMS) wavefront error (WFE) for individual aberrations and cumulative high-order (HO) RMS WFE for the normal human eye as a function of age by decade and pupil diameter in 1 mm steps from 3 to 7 mm and determine the relationship among HO RMS WFE, mean age for each decade of life, and luminance for physiologic pupil diameters. Subjects included 146 healthy individuals from 20 to 80 years of age. Ocular aberration was measured on the preferred eye of each subject (for a total of 146 eyes through dilated pupils; computed for 3, 4, 5, 6, and 7 mm pupils; and described with a tenth-radial-order normalized Zernike expansion. We found that HO RMS WFE increases faster with increasing pupil diameter for any given age and pupil diameter than it does with increasing age alone. A planar function accounts for 99% of the variance in the 3-D space defined by mean log HO RMS WFE, mean age for each decade of life, and pupil diameter. When physiologic pupil diameters are used to estimate HO RMS WFE as a function of luminance and age, at low luminance (9 cd/m2) HO RMS WFE decreases with increasing age. This normative data set details (1) the 3-D relationship between HO RMS WFE and age for fixed pupil diameters and (2) the 3-D relationship among HO RMS WFE, age, and luminance for physiologic pupil diameters. PMID:17301847

High energy, widely tunable Si-prism-array coupled terahertz-wave parametric oscillator with a deformed pump and optimal crystal location for angle tuning.

PubMed

Zhang, Ruiliang; Qu, Yanchen; Zhao, Weijiang; Chen, Zhenlei

2017-03-20

A high energy, widely tunable Si-prism-array coupled terahertz-wave parametric oscillator (TPO) has been demonstrated by using a deformed pump. The deformed pump is cut from a beam spot of 2 mm in diameter by a 1-mm-wide slit. In comparison with a small pump spot (1-mm diameter), the THz-wave coupling area for the deformed pump is increased without limitation to the low-frequency end of the tuning range. Besides, the crystal location is specially designed to eliminate the alteration of the output position of the pump during angle tuning, so the initially adjusted nearest pumped region to the THz-wave exit surface is maintained throughout the tuning range. The tuning range is 0.58-2.5 THz for the deformed pump, while its low frequency end is limited at approximately 1.2 THz for the undeformed pump with 2 mm diameter. The highest THz-wave output of 2 μJ, which is 2.25 times as large as that from the pump of 1 mm in diameter, is obtained at 1.15 THz under 38 mJ (300  MW/cm²) pumping. The energy conversion efficiency is 5.3×10^-5.

Relevance of impacter shape to nonvisible damage and residual tensile strength of a thick graphite/epoxy laminate

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.

1990-01-01

A study was made to determine the relevance of impacter shape to nonvisible damage and tensile residual strength of a 36 mm (1.4 in.) thick graphite/epoxy motor case. The shapes of the impacters were as follows: 12.7 mm (0.5 in.) and 25.4 mm (1.0 in.) diameter hemispheres, a sharp corner, and a 6.3 mm (0.25 in.) diameter bolt-like rod. The investigation revealed that damage initiated when the contact pressure exceeded a critical level. However, the damage was not visible on the surface until an even higher pressure was exceeded. The damage on the surface consisted of a crater shaped like the impacter, and the damage below the surface consisted of broken fibers. The impact energy to initiate damage or cause visible damage on the surface increased approximately with impacter diameter to the third power. The reduction in strength for nonvisible damage increased with increasing diameter, 9 and 30 percent for the 12.7 mm (0.5 in.) and 25.4 mm (1.0 in.) diameter hemispheres, respectively. The corner impacter made visible damage on the surface for even the smallest impact energy. The rod impacter acted like a punch and sliced through the composite. Even so, the critical level of pressure to initiate damage was the same for the rod and hemispherical impacters. Factors of safety for nonvisible damage increased with increasing kinetic energy of impact. The effects of impacter shape on impact force, damage size, damage visibility, and residual tensile strength were predicted quite well assuming Hertzian contact and using maximum stress criteria and a surface crack analysis.

Immediate provisionalization in the esthetic zone: 1-year interim results from a prospective single-cohort multicenter study evaluating 3.0-mm-diameter tapered implants.

PubMed

Kolinski, Martin; Hess, Pablo; Leziy, Sonia; Friberg, Bertil; Bellucci, Gionata; Trisciuoglio, Davide; Wagner, Wilfried; Moergel, Maximilian; Pozzi, Alessandro; Wiltfang, Jörg; Behrens, Eleonore; Zechner, Werner; Vasak, Christoph; Weigl, Paul

2018-07-01

The aim of this interim analysis of a 5-year prospective multicenter study is to evaluate clinical and radiological performance of immediately provisionalized 3.0-mm-diameter tapered implants. Patients needing implant rehabilitation of maxillary lateral incisors or mandibular lateral and central incisors were treated with 3.0-mm-diameter implants placed in extraction or healed sites and immediately provisionalized. Clinical and radiographic examinations were performed at implant insertion, 6 months thereafter, and are ongoing. Marginal bone levels and changes, complications, the papilla, plaque, and bleeding indices, and the pink esthetic score (PES) were evaluated at each follow-up visit. Of 112 enrolled patients, 77 patients (91 implants) met the inclusion criteria. Seventy-one patients with 82 implants completed the 1-year follow-up. Three implants failed yielding a CSR of 96.7%. All failures occurred within the first 3 months after implant insertion. Marginal bone level changes from insertion to 6 months was - 0.57 ± 1.30 mm (n = 75) and from insertion to 12 months - 0.25 ± 1.38 mm (n = 72). Fifteen non-serious complications were recorded. Papilla index score and PES improved at the 1-year follow-up. Plaque formation and bleeding-on-probing showed no statistically significant differences between the 6-month and the 1-year visit. This 1-year analysis demonstrated high survival, stable bone levels, and healthy soft tissue with 3.0-mm-diameter implants. Narrow diameter implants are a safe and predictable treatment option in patients with limited bone volume and/or limited interdental space and eligible for immediate loading protocols.

Eligibility for Renal Denervation: Anatomical Classification and Results in Essential Resistant Hypertension

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

Okada, Takuya, E-mail: okabone@gmail.com; Pellerin, Olivier; Savard, Sébastien

PurposeTo classify the renal artery (RA) anatomy based on specific requirements for endovascular renal artery denervation (RDN) in patients with drug-resistant hypertension (RH).Materials and MethodsThe RA anatomy of 122 consecutive RH patients was evaluated by computed tomography angiography and classified as two types: A (main RA ≥20 mm in length and ≥4.0 mm in diameter) or B (main RA <20 mm in length or main RA <4.0 mm in diameter). The A type included three subtypes: A1 (without accessory RAs), A2 (with accessory RAs <3.0 mm in diameter), and A3 (with accessory RAs ≥3.0 mm in diameter]. A1 and A2 types were eligible for RDN withmore » the Simplicity Flex catheter. Type B included twi subtypes based on the main RA length and diameter. Patients were accordingly classified into three eligibility categories: complete (CE; both RAs were eligible), partial (PE; one eligible RA), and noneligibility (NE; no eligible RA).ResultsBilateral A1 type was the most prevalent and was observed in 48.4 % of the patients followed by the A1/A2 type (18 %). CE, PE, and NE were observed in 69.7, 22.9, and 7.4 % of patients, respectively. The prevalence of accessory RAs was 41 %.ConclusionsOf RH patients, 30.3 % were not eligible for bilateral RDN with the current Simplicity Flex catheter. This classification provides the basis for standardized reporting to allow for pooling of results of larger patient cohorts in the future.« less

[Comparison of the anterior corneal asphericity after small incision lenticule extraction and femtosecond laser in situ keratomileusis].

PubMed

Su, X L; Wang, Y; Wu, W J; Wu, Z Q; Wu, Y N; Yu, C J

2016-09-11

To evaluate and compare the anterior corneal asphericity after small incision lenticule extraction(SMILE)and femtosecond laser in situ keratomileusis(FS-LASIK). In this case-control study, 45 subjects who underwent SMILE operation comprised the study group, and 33 subjects with FS-LASIK operation comprised the control group. The asphericity coefficient Q-value of the right eyes in both groups was measured at diameters of 6, 7, 8 and 9 mm, respectively, before surgery and at 1 day, 1 week, 1 month and 6 months following surgery. The correlation between the variation of Q-value and the central cutting depth was analyzed. The Q-value of anterior corneal surface was 0.85 ± 0.31, 0.80±0.28, 0.69±0.25 and 0.51±0.23 after SMILE, and 1.13±0.56, 1.01±0.47, 0.80±0.39 and 0.51±0.31 after FS-LASIK at 1 week. In both groups, the Q-value was significantly different before and after surgery(P< 0.05); there were interaction effects between the operation method and time; the difference between the two groups at 6-mm and 7-mm diameters was statistically significant(P<0.05). The variation of the Q-value before and after operation(ΔQ)showed significant difference(P6mm=0.004, P7mm=0.014)between the two groups at 6-mm and 7-mm diameters. The cap diameter of the SMILE group was smaller than that of the FS-LASIK group, but the cutting depth was larger. There was no correlation between ΔQ and the cap/disc diameter. It showed a linear relationship(P<0.05)between ΔQ and the central cutting depth at all examined diameters in the two groups, and the relation degree in the FS-LASIK group was superior to the SMILE group. Both SMILE and FS-LASIK operations can change the negative Q-value of the anterior corneal surface to the positive. The impact of SMILE on the asphericity is smaller than that of FS-LASIK. (Chin J Ophthalmol, 2016, 52: 681-685).

Impact of the Curve Diameter and Laser Settings on Laser Fiber Fracture.

PubMed

Haddad, Mattieu; Emiliani, Esteban; Rouchausse, Yann; Coste, Frederic; Doizi, Steeve; Berthe, Laurent; Butticé, Salvatore; Somani, Bhaskar; Traxer, Olivier

2017-09-01

To analyze the risk factors for laser fiber fractures when deflected to form a curve, including laser settings, size of the laser fiber, and the fiber bending diameter. Single-use 272 and 365 μm fibers (Rocamed ® , Monaco) were employed along with a holmium laser (Rocamed). Five different fiber curve diameters were tested: 9, 12, 15, 18, and 20 mm. Fragmentation and dusting settings were used at a theoretical power of 7.5 W. The laser was activated for 5 minutes and the principal judgment criterion was fiber fracture. Every test for each parameter, bending diameter, and fiber size combinations was repeated 10 times. With dusting settings, fibers broke more frequently at a curved diameter of 9 mm for both 272 and 365 μm fibers (p = 0.037 and 0.006, respectively). Using fragmentation settings, fibers broke more frequently at 12 mm for 272 μm and 15 mm for 365 μm (p = 0.007 and 0.033, respectively). Short pulse and high energy were significant risk factors for fiber fracture using the 365 μm fibers (p = 0.02), but not for the 272 μm fibers (p = 0.35). Frequency was not a risk factor for fiber rupture. Fiber diameters also seemed to be involved in the failure with a higher number of broken fibers for the 365 μm fibers, but this was not statistically significant when compared with the 272 μm fibers (p > 0.05). Small-core fibers are more resistant than large-core fibers as lower bending diameters (<9 mm) are required to break smaller fibers. In acute angles, the use of small-core fibers, at a low energy and long-pulse (dusting) setting, will reduce the risk of fiber rupture.

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

Lindsay, P. E., E-mail: Patricia.Lindsay@rmp.uhn.on.ca; Granton, P. V.; Hoof, S. van

Purpose: To compare the dosimetric and geometric properties of a commercial x-ray based image-guided small animal irradiation system, installed at three institutions and to establish a complete and broadly accessible commissioning procedure. Methods: The system consists of a 225 kVp x-ray tube with fixed field size collimators ranging from 1 to 44 mm equivalent diameter. The x-ray tube is mounted opposite a flat-panel imaging detector, on a C-arm gantry with 360° coplanar rotation. Each institution performed a full commissioning of their system, including half-value layer, absolute dosimetry, relative dosimetry (profiles, percent depth dose, and relative output factors), and characterization ofmore » the system geometry and mechanical flex of the x-ray tube and detector. Dosimetric measurements were made using Farmer-type ionization chambers, small volume air and liquid ionization chambers, and radiochromic film. The results between the three institutions were compared. Results: At 225 kVp, with 0.3 mm Cu added filtration, the first half value layer ranged from 0.9 to 1.0 mm Cu. The dose-rate in-air for a 40 × 40 mm{sup 2} field size, at a source-to-axis distance of 30 cm, ranged from 3.5 to 3.9 Gy/min between the three institutions. For field sizes between 2.5 mm diameter and 40 × 40 mm{sup 2}, the differences between percent depth dose curves up to depths of 3.5 cm were between 1% and 4% on average, with the maximum difference being 7%. The profiles agreed very well for fields >5 mm diameter. The relative output factors differed by up to 6% for fields larger than 10 mm diameter, but differed by up to 49% for fields ≤5 mm diameter. The mechanical characteristics of the system (source-to-axis and source-to-detector distances) were consistent between all three institutions. There were substantial differences in the flex of each system. Conclusions: With the exception of the half-value layer, and mechanical properties, there were significant differences between the dosimetric and geometric properties of the three systems. This underscores the need for careful commissioning of each individual system for use in radiobiological experiments.« less

Magnetic Resonance-Based Electrical Property Tomography (MR- EPT) for Prostate Cancer Grade Imaging

DTIC Science & Technology

2014-07-01

TV 2D 5 10 15 2 4 6 8 10 12 14 i 5 10 15 2 4 6 8 10 12 14 Figure 10. Prostate-like gelatin phantom with one inclusion (5mm, play dough ...magnitude image (TSE) and reconstructions. 11 c) Multiple Inclusions Two 5 mm diameter inclusions ( play dough to provide significant conductivity...reconstruction, 2D inverse reconstruction with Total Variation, 3D inverse reconstruction 10 b) Single inclusion A single 5 mm diameter inclusion ( play

Analysis of stresses at the bore of a drilled ball operating in a high-speed bearing. [with stiffening web

NASA Technical Reports Server (NTRS)

Coe, H. H.; Lynch, J. E.

1973-01-01

Three-dimensional stress distributions were calculated for both a regular drilled ball with a stiffening web. The balls were 20.6 mm (0.8125 in.) in diameter and had a 12.6 mm (0.496 in.) diameter concentric hole. The stiffening web was 1.5 mm (0.06 in.) thick. The calculations showed that a large reversing tangential stress at the hole bore was reduced by one-half by the addition of the web.

[Effect of staining method and sintering temperature on the color of porcelain-fused-to-metal restorations].

PubMed

Wang, Yan; Yan, Wei-hao; Zhang, Xin-chun; Huang, Yue; Shen, Lin-han

2004-12-01

To investigate the effect of staining method and sintering temperature on the color of porcelain-fused-metal restorations. 40 cylindrical stained porcelain-metal specimens of 15 mm in diameter and 6 mm in height were fabricated with customized mould, consisting of 2 mm Ni-Cr metal, 1 mm opaque porcelain, 2 mm dentine porcelain and 1 mm enamel porcelain. The specimens were prepared by 5 techniques, 8 for each group. Group A: internal staining, Group B: external staining, 900 degrees centigrade sintering temperature was used in both A and B group; Group C to E: external staining, with the sintering temperature of 880 degrees centigrade, 900 degrees centigrade and 920 degrees centigrade respectively. Sofu A2 porcelain and Sofu 44 stain system were used for the study. Using standard white plate as a reference, colors (L*,a*,b* coordinates) of the specimens were measured with a computerized colorimeter. Student's t test and one way ANOVA were used to analyze the data. DeltaE, b* and Delta C(ab)* of Group B (external staining) and group A (internal staining) were 43.72 +/- 2.99/26.51 +/- 1.64/31.31 +/- 2.48 and 39.71 +/- 1.78/23.69 +/- 0.36/26.55 +/- 2.16, respectively. The values of the former group were significantly higher than that of the latter (P < 0.05); For Group C to E, there were no significant differences in all the color parameters. Staining method has a significant effect on the color parameters of porcelain-fused-to-metal restorations; For external staining, within the clinically-used range, changing the sintering temperature does not have an obvious effect on the color.

Correction factors for the ISO rod phantom, a cylinder phantom, and the ICRU sphere for reference beta radiation fields of the BSS 2

NASA Astrophysics Data System (ADS)

Behrens, R.

2015-03-01

The International Organization for Standardization (ISO) requires in its standard ISO 6980 that beta reference radiation fields for radiation protection be calibrated in terms of absorbed dose to tissue at a depth of 0.07 mm in a slab phantom (30 cm x 30 cm x 15 cm). However, many beta dosemeters are ring dosemeters and are, therefore, irradiated on a rod phantom (1.9 cm in diameter and 30 cm long), or they are eye dosemeters possibly irradiated on a cylinder phantom (20 cm in diameter and 20 cm high), or area dosemeters irradiated free in air with the conventional quantity value (true value) being defined in a sphere (30 cm in diameter, made of ICRU tissue (International Commission on Radiation Units and Measurements)). Therefore, the correction factors for the conventional quantity value in the rod, the cylinder, and the sphere instead of the slab (all made of ICRU tissue) were calculated for the radiation fields of 147Pm, 85Kr, 90Sr/90Y, and, 106Ru/106Rh sources of the beta secondary standard BSS 2 developed at PTB. All correction factors were calculated for 0° up to 75° (in steps of 15°) radiation incidence. The results are ready for implementation in ISO 6980-3 and have recently been (partly) implemented in the software of the BSS 2.

Abnormal splenic artery diameter/hepatic artery diameter ratio in cirrhosis-induced portal hypertension

PubMed Central

Zeng, Dao-Bing; Dai, Chuan-Zhou; Lu, Shi-Chun; He, Ning; Wang, Wei; Li, Hong-Jun

2013-01-01

AIM: To determine an optimal cutoff value for abnormal splenic artery diameter/proper hepatic artery diameter (S/P) ratio in cirrhosis-induced portal hypertension. METHODS: Patients with cirrhosis and portal hypertension (n = 770) and healthy volunteers (n = 31) underwent volumetric computed tomography three-dimensional vascular reconstruction to measure the internal diameters of the splenic artery and proper hepatic artery to calculate the S/P ratio. The cutoff value for abnormal S/P ratio was determined using receiver operating characteristic curve analysis, and the prevalence of abnormal S/P ratio and associations between abnormal S/P ratio and major complications of portal hypertension were studied using logistic regression. RESULTS: The receiver operating characteristic analysis showed that the cutoff points for abnormal splenic artery internal diameter and S/P ratio were > 5.19 mm and > 1.40, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 74.2%, 45.2%, 97.1%, and 6.6%, respectively. The prevalence of an abnormal S/P ratio in the patients with cirrhosis and portal hypertension was 83.4%. Patients with a higher S/P ratio had a lower risk of developing ascites [odds ratio (OR) = 0.708, 95%CI: 0.508-0.986, P = 0.041] and a higher risk of developing esophageal and gastric varices (OR = 1.483, 95%CI: 1.010-2.175, P = 0.044) and forming collateral circulation (OR = 1.518, 95%CI: 1.033-2.230, P = 0.034). After splenectomy, the portal venous pressure and maximum and mean portal venous flow velocities were reduced, while the flow rate and maximum and minimum flow velocities of the hepatic artery were increased (P < 0.05). CONCLUSION: The prevalence of an abnormal S/P ratio is high in patients with cirrhosis and portal hypertension, and it can be used as an important marker of splanchnic hemodynamic disturbances. PMID:23483462

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

Denys, Alban, E-mail: alban.denys@chuv.ch; Lachenal, Yann; Duran, Rafael

PurposeTo report feasibility and potential benefits of high-frequency jet ventilation (HFJV) in tumor ablations techniques in liver, kidney, and lung lesions.MethodsThis prospective study included 51 patients (14 women, mean age 66 years) bearing 66 tumors (56 hepatic, 5 pulmonary, 5 renal tumors) with a median size of 16 ± 8.7 mm, referred for tumor ablation in an intention-to-treat fashion before preoperative anesthesiology visit. Cancellation and complications of HFJV were prospectively recorded. Anesthesia and procedure duration, as well as mean CO{sub 2} capnea, were recorded. When computed tomography guidance was used, 3D spacial coordinates of an anatomical target <2 mm in diameter on 8 slabs ofmore » 4 slices of 3.75-mm slice thickness were registered.ResultsHFJV was used in 41 of 51 patients. Of the ten patients who were not candidate for HFJV, two patients had contraindication to HFJV (severe COPD), three had lesions invisible under HFJV requiring deep inspiration apnea for tumor targeting, and five patients could not have HFJV because of unavailability of a trained anesthetic team. No specific complication or hypercapnia related to HFJV were observed despite a mean anesthetic duration of 2 h and ventilation performed in procubitus (n = 4) or lateral decubitus (n = 6). Measured internal target movement was 0.3 mm in x- and y-axis and below the slice thickness of 3.75 mm in the z-axis in 11 patients.ConclusionsHFJV is feasible in 80 % of patients allowing for near immobility of internal organs during liver, kidney, and lung tumor ablation.« less

Innovative Application of a Microlaryngeal Surgery Tube for difficult Airway Management in a Case of Down's Syndrome.

PubMed

Gulabani, Michell; Gupta, Akhilesh; Bannerjee, Neerja Gaur; Sood, Rajesh; Dass, Prashant

2016-04-01

An 11-year-old male child, known case of down's syndrome with congenital oesophageal stricture was posted for oesophageal dilatation. Preoperative airway assessment revealed a high arched palate, receding mandible and Mallampati Score of 2. During surgery, after loss of consciousness which was described as loss of eyelash reflex and adequate jaw relaxation, direct laryngoscopy and endotracheal intubation was attempted with a cuffed endotracheal tube number 5.0mm ID (internal diameter). The endotracheal tube could not be negotiated smoothly, so 5.0mm ID uncuffed endotracheal tube was used which passed through easily, but on auscultation revealed a significant leak. Later, intubation via a Micro Laryngeal Surgery (MLS) cuffed tube 4.0mm ID was attempted. The MLS tube advanced smoothly and there was no associated leak on positive pressure ventilation. Thus by innovative thinking and avant-garde reasoning, a definitive airway device could be positioned with no other suitable alternative at hand.

Folded path LWIR system for SWAP constrained platforms

NASA Astrophysics Data System (ADS)

Fleet, Erin F.; Wilson, Michael L.; Linne von Berg, Dale; Giallorenzi, Thomas; Mathieu, Barry

2014-06-01

Folded path reflection and catadioptric optics are of growing interest, especially in the long wave infrared (LWIR), due to continuing demands for reductions in imaging system size, weight and power (SWAP). We present the optical design and laboratory data for a 50 mm focal length low f/# folded-path compact LWIR imaging system. The optical design uses 4 concentric aspheric mirrors, each of which is described by annular aspheric functions well suited to the folded path design space. The 4 mirrors are diamond turned onto two thin air-spaced aluminum plates which can be manually focused onto the uncooled LWIR microbolometer array detector. Stray light analysis will be presented to show how specialized internal baffling can be used to reduce stray light propagation through the folded path optical train. The system achieves near diffraction limited performance across the FOV with a 15 mm long optical train and a 5 mm back focal distance. The completed system is small enough to reside within a 3 inch diameter ball gimbal.

Electrohydrodynamic (edh) drying of ginger slices (zingiber officinale)

NASA Astrophysics Data System (ADS)

Sumariyah; Khuriati, Ainie; Fachriyah, Enny

2018-05-01

Electrohydrodynamic (EHD) flow or ion wind of corona discharges has been generated utilizing pin-multi ring concentred electrodes. The pin was made of stainless steel with a tip diameter of 0.018 mm. The multi-ring constructed electrodes by a metal material connected to each other and each ring has a diameter of 24 mm, 16 mm and 8 mm in the same width and thickness is 4 mm and 1 mm. EHD was generated by using a DC high voltage of 5 kV. Pin as an active electrode of corona discharge and multi-ring concentric electrodes as a collector and passive electrodes. The ion wind or EHD flow is produced through changes in voltage and distance between electrodes. The ionic wind generated system outputs through multi-ring concentric electrodes which will further dry the sample. A circle ginger slices as a sample with a diameter of 26 mm with a thickness of 2 mm. The drying is done at the distance between the fixed electrodes of 4 mm and the varied voltages are 1.2 kV, 1.4 kV, and 1.6 kV. The sample drying time varied 30 minutes, 60 minutes, 90 minutes, 120 minutes and 150 minutes. The result of drying the sample at a fixed voltage is obtained moisture of ginger slices decreased with increased drying time.

Influence of implant diameter in the displacement of dental implants in trabecular bovine bone under a static lateral load: experimental results and computational modeling.

PubMed

Engelke, Wilfried; Decco, Oscar A; Cura, Andrea C; Maldonado, Isai; Crippa, Federico G

2014-12-01

Primary stability and micromovement of dental implants depend on structural properties of the surrounding bone and on implant dimension and design. The purpose of this study was to provide objective data for the influence of implant diameter on the displacement of titanium screw implants. Ninety Semados implants (length 15 mm, diameter 3.25, 3.75, and 4.5 mm; Bego, Bremen, Germany) were inserted in trabecular bone specimens. All implants were inserted with a torque up to 30 N·cm and loaded horizontally with 10, 20, and 30 N for 2 seconds. All implants showed primary stability. With increasing force, a gradual increase of micromovement was observed (Kruskal-Wallis test, P = 0.000). No significant differences were found (Kruskal-Wallis test, P = 0.148) comparing different diameters for every force. Variation of the diameter of standard implants between 3.25 and 4.5 mm does not seem to influence the primary stability in trabecular bone specimen. Differences between experimental and computational results may be due to the simplification used when modeling.

Spatial resolution limits for the isotropic-3D PET detector X’tal cube

NASA Astrophysics Data System (ADS)

Yoshida, Eiji; Tashima, Hideaki; Hirano, Yoshiyuki; Inadama, Naoko; Nishikido, Fumihiko; Murayama, Hideo; Yamaya, Taiga

2013-11-01

Positron emission tomography (PET) has become a popular imaging method in metabolism, neuroscience, and molecular imaging. For dedicated human brain and small animal PET scanners, high spatial resolution is needed to visualize small objects. To improve the spatial resolution, we are developing the X’tal cube, which is our new PET detector to achieve isotropic 3D positioning detectability. We have shown that the X’tal cube can achieve 1 mm3 uniform crystal identification performance with the Anger-type calculation even at the block edges. We plan to develop the X’tal cube with even smaller 3D grids for sub-millimeter crystal identification. In this work, we investigate spatial resolution of a PET scanner based on the X’tal cube using Monte Carlo simulations for predicting resolution performance in smaller 3D grids. For spatial resolution evaluation, a point source emitting 511 keV photons was simulated by GATE for all physical processes involved in emission and interaction of positrons. We simulated two types of animal PET scanners. The first PET scanner had a detector ring 14.6 cm in diameter composed of 18 detectors. The second PET scanner had a detector ring 7.8 cm in diameter composed of 12 detectors. After the GATE simulations, we converted the interacting 3D position information to digitalized positions for realistic segmented crystals. We simulated several X’tal cubes with cubic crystals from (0.5 mm)3 to (2 mm)3 in size. Also, for evaluating the effect of DOI resolution, we simulated several X’tal cubes with crystal thickness from (0.5 mm)3 to (9 mm)3. We showed that sub-millimeter spatial resolution was possible using cubic crystals smaller than (1.0 mm)3 even with the assumed physical processes. Also, the weighted average spatial resolutions of both PET scanners with (0.5 mm)3 cubic crystals were 0.53 mm (14.6 cm ring diameter) and 0.48 mm (7.8 cm ring diameter). For the 7.8 cm ring diameter, spatial resolution with 0.5×0.5×1.0 mm3 crystals was improved 39% relative to the (1 mm)3 cubic crystals. On the other hand, spatial resolution with (0.5 mm)3 cubic crystals was improved 47% relative to the (1 mm)3 cubic crystals. The X’tal cube promises better spatial resolution for the 3D crystal block with isotropic resolution.

Endovascular abdominal aortic stenosis treatment with the OptiMed self-expandable nitinol stent.

PubMed

Ghazi, Payam; Haji-Zeinali, Ali-Mohammad; Shafiee, Nahid; Qureshi, Shakeel A

2009-10-01

To evaluate the safety and feasibility of self-expandable stents (OptiMed) for treatment of abdominal aortic stenosis in the situations in which the aortic stenosis locates near the origin of celiac, superior mesenteric, renal and inferior mesenteric arteries. Five consecutive patients scheduled for endovascular treatment of abdominal aortic stenosis by self-expandable nitinol stent (Sinus-Aorta/OptiMed) implantation. The diameter of the stent was chosen as 10-30% more than that of the normal portion of the aorta above the stenosis. Long stents of 60 mm or longer were chosen. After stent deployment, balloon postdilation was performed with a balloon in patients with residual gradient > 5 mm Hg. All patients were successfully treated with the OptiMed stents. The balloon predilation was performed in one patient due to severe stenosis. The mean diameter and length of the stents deployed were 20.4 +/- 2.9 (range, 16-24 mm) and 64 +/- 8.9 (range, 60-80 mm), respectively. The balloon postdilation was performed in all cases. The mean diameter of the balloons was 13.6 +/- 1.5 (range, 12-15 mm). The mean diameter of stenosis increased from 4.8 +/- 1.9 to 14.4 +/- 1.8 mm after stent placement. The mean peak systolic gradient decreased from 46.8 +/- 31.5 mm Hg to 0.8 +/- 1.8 mm Hg. During follow-up (22.8 +/- 14.3 months), none of the patients had restenosis within the stent, occlusion of any branches of the aorta, or other related complications. In our small series, we observed that abdominal aortic stenosis can be successfully and effectively treated with OptiMed stents in the situations in which the stenotic segment is located next to the origins of the main visceral branches of abdominal aorta.

Suprascarpal fat pad thickness may predict venous drainage patterns in abdominal wall flaps.

PubMed

Bast, John; Pitcher, Austin A; Small, Kevin; Otterburn, David M

2016-02-01

Abdominal wall flaps are routinely used in reconstructive procedures. In some patients inadequate venous drainage from the deep vein may cause fat necrosis or flap failure. Occasionally the superficial inferior epigastric vessels (SIEV) are of sufficient size to allow for microvascular revascularization. This study looked at the ratio of the sub- and suprascarpal fat layers, the number of deep system perforators, and SIEV diameter to determine any correlation of the fat topography and SIEV. 50 abdominal/pelvic CT angiograms (100 hemiabdomens) were examined in women aged 34-70 years for number of perforators, SIEV diameter, and fat pad thickness above and below Scarpa's fascia. Data was analyzed using multivariate model. The average suprascarpal and subscarpal layers were 18.6 ± 11.5 mm and 6.2 ± 7.2 mm thick, respectively. The average SIEV diameter was 2.06 ± 0.81 mm and the average number of perforators was 2.09 ± 1.03 per hemiabdomen. Hemiabdomens with suprascarpal thickness>23 mm had greater SIEV diameter [2.69 mm vs. 1.8 mm (P < 0.0001)] The fat layer thickness did not correlate with the number of perforators. Neither subscarpal fat thickness nor suprascarpal-to-subscarpal fat layer thickness correlated significantly with SIEV caliber or number of perforators in multivariate model. Suprascarpal fat pad thicker than 23 mm had larger SIEVs irrespective of the number of deep system perforators. This may indicate a cohort of patients at risk of venous congestion from poor venous drainage if only the deep system is revascularized. We recommend harvesting the SIEV in patients with suprascarpal fat pad >23 mm to aid in superficial drainage. © 2015 Wiley Periodicals, Inc.

Coronary artery size and disease in UK South Asian and Caucasian men.

PubMed

Zindrou, Dlear; Taylor, Kenneth M; Bagger, Jens Peder

2006-04-01

South Asian patients in the UK have a higher mortality rate after coronary artery bypass grafting (CABG) than Caucasian patients. As coronary artery size has been shown to correlate to outcome from bypass grafting, it has been suggested that smaller coronary arteries in South Asians as compared to Caucasians could contribute to a poorer outcome in the Asian population. We aimed to measure coronary artery size and disease in matched South Asian and Caucasian men undergoing first time coronary artery bypass grafting. Coronary arteriograms from 53 matched first generation South Asian and Caucasian men were examined. The patients had no history of myocardial infarction, coronary revascularisation, familial dyslipidaemia, diabetes or renal disease. They were individually matched for age, height, weight, body mass index and body surface area. Thereafter, coronary artery diameters and significant (> or =50%) diameter stenoses were measured in a blinded fashion using quantitative coronary angiography (QCA). In South Asian men, diameters of the left main stem (LMS) and the proximal left anterior descending, the circumflex and the right coronary arteries were 4.6+/-0.9 mm, 3.5+/-0.8 mm, 3.4+/-0.8 mm and 3.5+/-0.8 mm, respectively. The corresponding arterial diameters among Caucasian men (4.5+/-0.9 mm, 3.5+/-0.7 mm, 3.5+/-0.8 mm and 3.8+/-0.8 mm) did not differ from those in South Asians. There was no difference in the number of significant coronary artery stenoses between the two groups and no difference in bypass and cross-clamp times or in adverse outcome (one from each group died after coronary artery bypass grafting). Proximal coronary artery size and number of significant coronary stenoses did not differ between matched pairs of South Asian and Caucasian men using strict inclusion/exclusion criteria.

The effect of geometry and operation conditions on the performance of a gas-liquid cylindrical cyclone separator with new structure

NASA Astrophysics Data System (ADS)

Han, Qing; Zhang, Chi; Xu, Bo; Chen, Jiangping

2013-07-01

The hydrodynamic flow behavior, effects of geometry and working conditions of a gas-liquid cylindrical cyclone separator with a new structure are investigated by computational fluid dynamic and experiment. Gas liquid cylindrical cyclone separator is widely used in oil industry, refrigeration system because of its simple structure, high separating efficiency, little maintenance and no moving parts nor internal devices. In this work, a gas liquid cylindrical cyclone separator with new structure used before evaporator in refrigeration system can remove the vapor from the mixture and make evaporator compact by improving its heat exchange efficiency with the lower inlet quality. It also decreases evaporator pressure drop and reduces compressor work. The two pipes are placed symmetrically which makes each of them can be treated as inlet. It means when the fluids flow reverse, the separator performance will not be influence. Four samples with different geometry parameters are tested by experiment with different inlet quality (0.18-0.33), inlet mass flow rate (65-100kg/h). Compared with the experimental data, CFD simulation results show a good agreement. Eulerian multiphase model and Reynolds Stress Turbulence model are applied in the CFD simulation and obtained the inner flow field such as phase path lines, tangential velocity profiles and pressure and volume of fraction distribution contours. The separator body diameter (24, 36, 48mm) and inlet diameter (3.84, 4.8, 5.76mm) decide the maximum tangential velocity which results in the centrifugal force. The tangential velocity profiles are simulated and compared among different models. The higher tangential velocity makes higher quality of gas outlet but high pressure drop at the same time. Decreasing the inlet diameter increases quality of gas outlet pipe and pressure drop. High gas outlet quality is cost at high pressure drop. Increasing of separator diameter makes gas outlet quality increase first and then decrease but the pressure drop decreases all the way. The offset (0, 2.4, 3.6mm) of gas outlet is an insensitive factor which influences the quality and pressure drop little.

Summary of a study to determine low-velocity impact damage and residual tension strength for a thick graphite/epoxy motor case

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.

1990-01-01

Impacters of various shapes and masses were dropped from various heights onto 36 mm (1.4 in.) thick graphite/epoxy cylinders, which represented filament wound cases (FWC) for the booster motors of the Space Shuttle. Insert solid propellant was cast into some of the cylinders. The cylinders were impacted numerous times around the circumference and then cut into 51 mm (2.0 in.) wide tension specimens, each containing an impact site. Four indenters were used: a sharp corner, two hemispheres, and a bolt-like rod. The diameters of the hemispheres were 12.7 mm (0.5 in.) and 25.4 mm (1.0 in.), and the diameter of the rod was 6.3 mm (0.25 in.). Impacts with the rod were simulated by pressing the rod against the face of specimens. For the hemispheres, the damage initiated beneath the surface at a critical contact pressure and was not visible on the surface until an even larger pressure was exceeded. The damage consisted of matrix cracking and broken fiber. The rod and corner made visible surface damage in all tests. For the hemispheres, the tension strength was reduced considerably before the damage was visible on the surface, 30 percent for the 25.4 mm (1.0 in.) diameter hemisphere and 10 percent for the 12.7 mm (0.5 in.) diameter hemisphere. Analytical methods were used to predict the damage and residual tension strength. A factor of safety to account for nonvisible damage was determined.

SU-E-J-229: Magnetic Resonance Imaging of Small Fiducial Markers for Proton Beam Therapy

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

Hu, Y; James, J; Panda, A

2015-06-15

Purpose: For proton beam therapy, small fiducial markers are preferred for patient alignment due to less interference with the proton beam. Visualizing small fiducial markers can be challenging in MRI. This study intends to investigate MRI imaging protocols for better visualization of small fiducial markers. Methods: Two carbon and two coil-shaped gold markers were placed into a gel phantom. Both carbon markers had a diameter of 1mm and a length of 3mm. Both gold markers had a length of 5mm. One gold marker had a diameter of 0.5mm and the other had a diameter of 0.75mm. T1 VIBE, T2 SPACE,more » TrueFISP and susceptibility weighted (SW) images were acquired. To improve marker contrast, high spatial resolution was used to reduce partial volume effect. Slice thickness was 1.5mm for all four sequences and in-plane resolution was 0.6mm for TrueFISP, 0.7mm for T1 VIBE, and 0.8mm for T2 SPACE and SW. For comparison purpose, a 3D T1 VIBE image set at 3mm slice thickness and 1.2mm in-plane resolution was also acquired. Results: All markers were visible in all high-resolution image sets. In each image set, marker-induced signal void was the smallest (in diameter) for carbon markers, followed by the 0.5mm gold marker and the largest for the 0.75mm gold marker. The SW images had the largest marker-induced signal void. However, those might be confused by susceptibility-gradient-induced signal voids. T1 VIBE had good visualization of markers with nicely defined edges. T2 SPACE had reasonable visualization of markers but edges were slightly blurred. TrueFISP had good visualization of markers only if they were not masked by banding artifacts. As a comparison, all markers were hardly visible in the standard resolution T1 VIBE images. Conclusion: 3D high-resolution T1 VIBE and SW have great potential in providing good visualization of small fiducial markers for proton beam therapy.« less

Beat-to-beat respiratory motion correction with near 100% efficiency: a quantitative assessment using high-resolution coronary artery imaging.

PubMed

Scott, Andrew D; Keegan, Jennifer; Firmin, David N

2011-05-01

This study quantitatively assesses the effectiveness of retrospective beat-to-beat respiratory motion correction (B2B-RMC) at near 100% efficiency using high-resolution coronary artery imaging. Three-dimensional (3D) spiral images were obtained in a coronary respiratory motion phantom with B2B-RMC and navigator gating. In vivo, targeted 3D coronary imaging was performed in 10 healthy subjects using B2B-RMC spiral and navigator gated balanced steady-state free-precession (nav-bSSFP) techniques. Vessel diameter and sharpness in proximal and mid arteries were used as a measure of respiratory motion compensation effectiveness and compared between techniques. Phantom acquisitions with B2B-RMC were sharper than those acquired with navigator gating (B2B-RMC vs. navigator gating: 1.01±0.02 mm(-1) vs. 0.86±0.08 mm(-1), P<.05). In vivo B2B-RMC respiratory efficiency was significantly and substantially higher (99.7%±0.5%) than nav-bSSFP (44.0%±8.9%, P<.0001). Proximal and mid vessel sharpnesses were similar (B2B-RMC vs. nav-bSSFP, proximal: 1.00±0.14 mm(-1) vs. 1.08±0.11 mm(-1), mid: 1.01±0.11 mm(-1) vs. 1.05±0.12 mm(-1); both P=not significant [ns]). Mid vessel diameters were not significantly different (2.85±0.39 mm vs. 2.80±0.35 mm, P=ns), but proximal B2B-RMC diameters were slightly higher (2.85±0.38 mm vs. 2.70±0.34 mm, P<.05), possibly due to contrast differences. The respiratory efficiency of B2B-RMC is less variable and significantly higher than navigator gating. Phantom and in vivo vessel sharpness and diameter values suggest that respiratory motion compensation is equally effective. Copyright © 2011 Elsevier Inc. All rights reserved.

Influence of fine threads and platform-switching on crestal bone stress around implant-a three-dimensional finite element analysis.

PubMed

Khurana, Pardeep; Sharma, Arun; Sodhi, Kiranmeet Kaur

2013-12-01

The aims of this study were to investigate the effect of implant fine threads on crestal bone stress compared to a standard smooth implant collar and to analyze how different abutment diameters influenced the crestal bone stress level. Three-dimensional finite element imaging was used to create a cross-sectional model in SolidWorks 2007 software of an implant (5-mm platform and 10 mm in length) placed in the premolar region of the mandible. The implant model was created to resemble a commercially available fine thread implant. Abutments of different diameters (5.0 mm: standard, 4.5 mm, 4.0 mm, and 3.5 mm) were loaded with a force of 100 N at 90° vertical and 40° oblique angles. Finite element analysis was done in COSMOSWorks software, which was used to analyze the stress patterns in bone, especially in the crestal region. Upon loading, the fine thread implant model had greater stress at the crestal bone adjacent to the implant than the smooth neck implant in both vertical and oblique loading. When the abutment diameter decreased progressively from 5.0 mm to 4.5 mm to 4 mm and to 3.5 mm the thread model showed a reduction of stress at the crestal bone level from 23.2 MPa to 15.02 MPa for fine thread and from 22.7 to 13.5 MPa for smooth collar implant group after vertical loading and from 43.7 MPa to 33.1 MPa in fine thread model and from 36.9 to 20.5 MPa in smooth collar implant model after oblique loading. Fine threads increase crestal stress upon loading. Reduced abutment diameter that is platform switching resulted in less stress translated to the crestal bone in the fine thread and smooth neck.

Aortic elongation and the risk for dissection: the Tübingen Aortic Pathoanatomy (TAIPAN) project†.

PubMed

Krüger, Tobias; Oikonomou, Alexandre; Schibilsky, David; Lescan, Mario; Bregel, Katharina; Vöhringer, Luise; Schneider, Wilke; Lausberg, Henning; Blumenstock, Gunnar; Bamberg, Fabian; Schlensak, Christian

2017-06-01

We measured aortic dimensions, particularly length parameters, using 3D imaging with the aim of refining the risk-morphology for Stanford type A aortic dissection (TAD). Computer tomography angiography studies were analysed using the curved multiplanar reformats. At defined landmarks, the diameters and lengths of aortic segments were recorded. Three groups were compared retrospectively: patients actually suffering from a TAD (TAD-group; n  = 150), patients before suffering a TAD (preTAD-group n  = 15) and a healthy control group ( n  = 215). Receiver operating characteristic curves (ROCs) were analysed (control versus preTAD) to study the diagnostic value of the individual variables. Median diameters of preTAD (43 mm) and TAD (50 mm) aortas were significantly ( P  < 0.001) larger than those of the control group (35 mm). Ninety-three percent of preTAD and 68% of TAD aortas were less than 55 mm in the mid-ascending aorta. The ascending aorta and the aortic arch were significantly longer in both preTAD and TAD aortas compared to control aortas ( P  < 0.001); in the control aortas the central line distance from the aortic valve to the brachiocephalic trunk was 93 mm. In preTAD aortas, it was 111 mm, and it was 117 mm in TAD aortas ( P  < 0.001). In ROC analysis, the area under the curve was 0.912 for the ascending diameter and 0.787 for the ascending and arch lengths. TAD-prediction based on the aortic diameter is ineffective. Besides circumferential dilatation, ascending aorta elongation precedes TAD and appears to be a useful additional parameter for prognostication. We propose a diagnostic score involving ascending aorta diameter and length. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Ring-Sheared Drop (RSD): Microgravity Module for Containerless Flow Studies

NASA Astrophysics Data System (ADS)

Gulati, Shreyash; Raghunandan, Aditya; Rasheed, Fayaz; McBride, Samantha A.; Hirsa, Amir H.

2017-02-01

Microgravity is potentially a powerful tool for investigating processes that are sensitive to the presence of solid walls, since fluid containment can be achieved by surface tension. One such process is the transformation of protein in solution into amyloid fibrils; these are protein aggregates associated with neurodegenerative diseases such as Alzheimer's and Parkinson's. In addition to solid walls, experiments with gravity are also subject to influences from sedimentation of aggregates and buoyancy-driven convection. The ring-sheared drop (RSD) module is a flow apparatus currently under development to study formation of amyloid fibrils aboard the International Space Station (ISS). A 25 mm diameter drop of protein solution will be contained by surface tension and constrained by a pair of sharp-edged tubes, forming two contact rings. Shear can be imparted by rotating one ring with the other ring kept stationary. Here we report on parabolic flights conducted to test the growth and pinning of 10 mm diameter drops of water in under 10 s of microgravity. Finite element method (FEM) based fluid dynamics computations using a commercial package (COMSOL) assisted in the design of the parabolic flight experiments. Prior to the parabolic flights, the code was validated against experiments in the lab (1 g), on the growth of sessile and pendant droplets. The simulations show good agreement with the experiments. This modeling capability will enable the development of the RSD at the 25 mm scale for the ISS.

Influence of dust particles on the neon spectral line intensities at the uniform positive column of dc discharge at the space apparatus “Plasma Kristall-4”

NASA Astrophysics Data System (ADS)

Usachev, A. D.; Zobnin, A. V.; Shonenkov, A. V.; Lipaev, A. M.; Molotkov, V. I.; Petrov, O. F.; Fortov, V. E.; Pustyl'nik, M. Y.; Fink, M. A.; Thoma, M. A.; Thomas, H. M.; Padalka, G. I.

2018-01-01

Influence of the elongated dust cloud on the intensities of different neon spectral lines in visible and near ir spectral ranges in the uniform positive column has been experimentally investigated using the Russian-European space apparatus “Plasma Kristall-4” (SA PK-4) on board of the International Space Station (ISS). The investigation was performed in the low pressure (0.5 mbar) direct current (dc, 1 mA) gas discharge in neon. Microgravity allowed us to perform experiments with a large dust cloud in the steady-state regime. To avoid the dust cloud drift in the dc electric field a switching dc polarity discharge mode has been applied. During the experiment a dust cloud of 9 mm in diameter in the discharge tube of 30 mm in diameter with the length of about 100 mm has been observed in the steady-state regime. In this regard, the intensities of neon spectral lines corresponding to 3p → 3s electronic transitions have increased by a factor of 1.4 times, while the intensities of neon spectral lines corresponding to 3d → 3p electronic transitions have increased by a factor of 1.6 times. The observed phenomenon is explained on the basis of the Schottky approach by a self-consistent rising dc electric field in the dusty plasma cloud resulting in an increase of the electron temperature.

Holmium: YAG laser-induced liquid jet knife: possible novel method for dissection.

PubMed

Nakagawa, Atsuhiro; Hirano, Takayuki; Komatsu, Makoto; Sato, Mariko; Uenohara, Hiroshi; Ohyama, Hideki; Kusaka, Yasuko; Shirane, Reizo; Takayama, Kazuyoshi; Yoshimoto, Takashi

2002-01-01

Making surgical incisions in vessel-rich organs without causing bleeding is difficult. Thus, it is necessary to develop new devices for this purpose, especially for surgery involving small vessels as in neurosurgery, where damage against even small cerebral vessels result in severe neurological deficits. A laser-induced liquid jet was generated by irradiating pulsed Holmium Yttrium-Aluminum-Garnet (Ho: YAG) laser (beams of 350 microseconds pulse width) within a copper tube (internal diameter, 1 mm) with pure water (150 ml /hour). Ho: YAG laser beams were irradiated through an optical fiber (core diameter, 0.4 mm). The influence of the input of laser energy, structure of the nozzle, and the stand-off distance between the optical fiber tip and nozzle exit on the jet velocity was measured by a high-speed video camera to evaluate controllability of jet. The effect on artificial organs made of 10 and 30%(w/v) gelatin, each of which represent features of soft tissue and blood vessels. Jet velocity increased in proportion to gain in laser energy input, and maximum penetration depth into 10%(w/v) gelatin was 35 mm by single exposure at 350 mJ/pulse without impairing a vessel model. Shapes of nozzle also modified jet velocity with optimal nozzle/tube area ratio of 0.25. The laser-induced liquid jet has excellent potential as a new tool for removing soft tissue without damaging vital structures. Copyright 2002 Wiley-Liss, Inc.

Experimental study of cryogen spray properties for application in dermatologic laser surgery.

PubMed

Aguilar, Guillermo; Majaron, Boris; Karapetian, Emil; Lavernia, Enrique J; Nelson, J Stuart

2003-07-01

Cryogenic sprays are used for cooling human skin during laser dermatologic surgery. In this paper, six straight-tube nozzles are characterized by photographs of cryogenic spray shapes, as well as measurements of average droplet diameter, velocity, and temperature. A single-droplet evaporation model to predict average spray droplet diameter and temperature is tested using the experimental data presented here. The results show two distinct spray patterns--sprays for 1.4-mm-diameter nozzles (wide nozzles) show significantly larger average droplet diameters and higher temperatures as a function of distance from the nozzle compared with those for 0.5-0.8-mm-diameter nozzles (narrow nozzles). These results complement and support previously reported studies, indicating that wide nozzles induce more efficient heat extraction than the narrow nozzles.

Effect of hole geometry and Electric-Discharge Machining (EDM) on airflow rates through small diameter holes in turbine blade material

NASA Technical Reports Server (NTRS)

Hippensteele, S. A.; Cochran, R. P.

1980-01-01

The effects of two design parameters, electrode diameter and hole angle, and two machine parameters, electrode current and current-on time, on air flow rates through small-diameter (0.257 to 0.462 mm) electric-discharge-machined holes were measured. The holes were machined individually in rows of 14 each through 1.6 mm thick IN-100 strips. The data showed linear increase in air flow rate with increases in electrode cross sectional area and current-on time and little change with changes in hole angle and electrode current. The average flow-rate deviation (from the mean flow rate for a given row) decreased linearly with electrode diameter and increased with hole angle. Burn time and finished hole diameter were also measured.

A numerical study of zone-melting process for the thermoelectric material of Bi2Te3

NASA Astrophysics Data System (ADS)

Chen, W. C.; Wu, Y. C.; Hwang, W. S.; Hsieh, H. L.; Huang, J. Y.; Huang, T. K.

2015-06-01

In this study, a numerical model has been established by employing a commercial software; ProCAST, to simulate the variation/distribution of temperature and the subsequent microstructure of Bi2Te3 fabricated by zone-melting technique. Then an experiment is conducted to measure the temperature variation/distribution during the zone-melting process to validate the numerical system. Also, the effects of processing parameters on crystallization microstructure such as moving speed and temperature of heater are numerically evaluated. In the experiment, the Bi2Te3 powder are filled into a 30mm diameter quartz cylinder and the heater is set to 800°C with a moving speed 12.5 mm/hr. A thermocouple is inserted in the Bi2Te3 powder to measure the temperature variation/distribution of the zone-melting process. The temperature variation/distribution measured by experiment is compared to the results of numerical simulation. The results show that our model and the experiment are well matched. Then the model is used to evaluate the crystal formation for Bi2Te3 with a 30mm diameter process. It's found that when the moving speed is slower than 17.5 mm/hr, columnar crystal is obtained. In the end, we use this model to predict the crystal formation of zone-melting process for Bi2Te3 with a 45 mm diameter. The results show that it is difficult to grow columnar crystal when the diameter comes to 45mm.

Anatomical Thin Titanium Mesh Plate Structural Optimization for Zygomatic-Maxillary Complex Fracture under Fatigue Testing.

PubMed

Wang, Yu-Tzu; Huang, Shao-Fu; Fang, Yu-Ting; Huang, Shou-Chieh; Cheng, Hwei-Fang; Chen, Chih-Hao; Wang, Po-Fang; Lin, Chun-Li

2018-01-01

This study performs a structural optimization of anatomical thin titanium mesh (ATTM) plate and optimal designed ATTM plate fabricated using additive manufacturing (AM) to verify its stabilization under fatigue testing. Finite element (FE) analysis was used to simulate the structural bending resistance of a regular ATTM plate. The Taguchi method was employed to identify the significance of each design factor in controlling the deflection and determine an optimal combination of designed factors. The optimal designed ATTM plate with patient-matched facial contour was fabricated using AM and applied to a ZMC comminuted fracture to evaluate the resting maxillary micromotion/strain under fatigue testing. The Taguchi analysis found that the ATTM plate required a designed internal hole distance to be 0.9 mm, internal hole diameter to be 1 mm, plate thickness to be 0.8 mm, and plate height to be 10 mm. The designed plate thickness factor primarily dominated the bending resistance up to 78% importance. The averaged micromotion (displacement) and strain of the maxillary bone showed that ZMC fracture fixation using the miniplate was significantly higher than those using the AM optimal designed ATTM plate. This study concluded that the optimal designed ATTM plate with enough strength to resist the bending effect can be obtained by combining FE and Taguchi analyses. The optimal designed ATTM plate with patient-matched facial contour fabricated using AM provides superior stabilization for ZMC comminuted fractured bone segments.

Flexible waveguides for IR laser radiation and surgery applications.

PubMed

Gannot, I; Dror, J; Calderon, S; Kaplan, I; Croitoru, N

1994-01-01

Flexible plastic waveguides were developed to deliver IR radiation, especially at 10.6 microns, which is the CO2 laser radiation wavelength. The waveguide is made from teflon tube with the inner wall coated with a metal layer and a dielectric overlayer. The internal diameter (ID) is 1.0 mm, length 1.0-1.2 m, and the distal tip decreases moderately to ID approximately 0.6 mm. The distal part on the last 10 centimeters is coated externally with a metal layer. Maximum power that can be delivered at the outlet is approximately 30 W and 10.6 x 10(3) W/cm2. This type of waveguide was used in several medical operations to evaluate its cutting characteristics and the resistances to heat reflection from the tissue while operating in orifices containing liquid substances.

Moissanite anvil cell design for Giga-Pascal nuclear magnetic resonance.

PubMed

Meier, Thomas; Herzig, Tobias; Haase, Jürgen

2014-04-01

A new design of a non-magnetic high-pressure anvil cell for nuclear magnetic resonance (NMR) experiments at Giga-Pascal pressures is presented, which uses a micro-coil inside the pressurized region for high-sensitivity NMR. The comparably small cell has a length of 22 mm and a diameter of 18 mm, so it can be used with most NMR magnets. The performance of the cell is demonstrated with external-force vs. internal-pressure experiments, and the cell is shown to perform well at pressures up to 23.5 GPa using 800 μm 6H-SiC large cone Boehler-type anvils. (1)H, (23)Na, (27)Al, (69)Ga, and (71)Ga NMR test measurements are presented, which show a resolution of better than 4.5 ppm, and an almost maximum possible signal-to-noise ratio.

Congenital lumbar spinal stenosis: a prospective, control-matched, cohort radiographic analysis.

PubMed

Singh, Kern; Samartzis, Dino; Vaccaro, Alexander R; Nassr, Ahmad; Andersson, Gunnar B; Yoon, S Tim; Phillips, Frank M; Goldberg, Edward J; An, Howard S

2005-01-01

Degenerative lumbar spinal stenosis manifests primarily after the sixth decade of life as a result of facet hypertrophy and degenerative disc disease. Congenital stenosis, on the other hand, presents earlier in age with similar clinical findings but with multilevel involvement and fewer degenerative changes. These patients may have subtle anatomic variations of the lumbar spine that may increase the likelihood of thecal sac compression. However, to the authors' knowledge, no quantitative studies have addressed various radiographic parameters of symptomatic, congenitally stenotic individuals to normal subjects. To radiographically quantify and compare the anatomy of the lumbar spine in symptomatic, congenitally stenotic individuals to age- and sex-matched, asymptomatic, nonstenotic controlled individuals. A prospective, control-matched, cohort radiographic analysis. Axial and sagittal magnetic resonance imaging (MRI) and lateral, lumbar, plain radiographs of 20 surgically treated patients who were given a clinical diagnosis of congenital lumbar stenosis by the senior author were randomized with images of 20, asymptomatic age- and sex-matched subjects. MRIs and lateral, lumbar, plain radiographs were independently quantitatively assessed by two individuals. Measurements obtained from the axial MRIs included: midline anterior-posterior (AP) vertebral body diameter, vertebral body width, midline AP canal diameter, canal width, spinal canal cross-sectional area, pedicle length, and pedicle width. From the sagittal MRIs, the following measurements were calculated: AP vertebral body diameter, vertebral body height, and AP canal diameter at the mid-vertebral level. On the lateral, lumbar, plain radiograph (L3 level), the AP diameters of the vertebral body spinal canal were measured. The images of these 40 individuals were then randomized and distributed in a blinded fashion to five separate spine surgeons who graded the presence and severity of congenital stenosis utilizing a five-tier scale. Images consisting of 15 symptomatic individuals, graded definitely congenitally stenotic (mean age, 51.7 years; range, 43-65 years), and 15 asymptomatic individuals, graded definitely not stenotic (mean age, 50.7 years; range, 41-55 years), were age- and sex-matched and included for further review. From these 30 patients, a lateral, lumbar, plain radiograph and axial and sagittal MRIs (T1/T2 weighted) from L2-L5 were quantitatively analyzed. Rater reliability was assessed by Kappa coefficient testing. The cross-sectional area of the canal was significantly smaller in the congenitally stenotic patients at all lumbar levels measured (L2: 176 mm(2) vs. 259 mm(2), L3: 177 mm(2) vs. 275 mm(2), L4: 183 mm(2) vs. 283 mm(2), L5: 213 mm(2) vs. 323 mm(2), p<.05). Pedicle length was markedly shorter in the stenosis group at each lumbar level (L2: 5.9 mm vs. 8.9 mm, L3: 6.0 mm vs. 8.8 mm, L4: 6.5 mm vs. 9.2 mm, L5: 5.8 mm vs. 9.1 mm, p<.05). Furthermore, midline, axial AP canal diameter, vertebral body width, and sagittal AP canal diameter were all significantly smaller than the control patients (p<.05). A ratio of the AP diameter of the pedicle length to the vertebral body was also noted to be statistically significant on both the lateral plain radiographs (L3: 0.426 vs. 0.704) and sagittal MRI (L2: 0.343 vs. 0.461, L3: 0.361 vs. 0.461, L4: 0.362 vs. 0.481, L5: 0.354 vs. 0.452, p<.05). No difference was noted comparing the AP diameter of the vertebral body (axial and sagittal images), vertebral body height, canal width, and pedicle width. Kappa testing coefficient indicated a strong rater reliability (k=0.81, 95% confidence interval: 0.62-0.94). Congenital lumbar stenosis has not been clearly defined radiographically. Clinically, congenitally stenotic patients present at a younger age with fewer degenerative changes and multiple levels of involvement. Radiographically, these patients have a shorter pedicular length and as a result a smaller cross-sectional spinal canal area (mean critical values of 6.5 mm and 213 mm(2) were observed, respectively). The mean critical ratios were 0.43 (2:1 AP vertebral body: pedicle length) on the lateral lumbar radiograph and 0.36 on the sagittal MRI. The altered canal anatomy resulting from a decreased pedicle length may anatomically predispose these patients to earlier complaints of symptomatic neurogenic claudication. Identification of the presence of congenital stenosis should increase the treating surgeon's awareness of the potential need for multilevel treatment.

Large eccentric laser angioplasty catheter

NASA Astrophysics Data System (ADS)

Taylor, Kevin D.; Reiser, Christopher

1997-05-01

In response to recent demand for increased debulking of large diameter coronary vascular segments, a large eccentric catheter for excimer laser coronary angioplasty has been developed. The outer tip diameter is 2.0 mm and incorporates approximately 300 fibers of 50 micron diameter in a monorail- type percutaneous catheter. The basic function of the device is to ablate a coronary atherosclerotic lesion with 308 nm excimer laser pulses, while passing the tip of the catheter through the lesion. By employing multiple passes through the lesion, rotating the catheter 90 degrees after each pass, we expect to create luminal diameters close to 3 mm with this device. Design characteristics, in-vitro testing, and initial clinical experience is presented.

Internal Flow of Contra-Rotating Small Hydroturbine at Off- Design Flow Rates

NASA Astrophysics Data System (ADS)

SHIGEMITSU, Toru; TAKESHIMA, Yasutoshi; OGAWA, Yuya; FUKUTOMI, Junichiro

2016-11-01

Small hydropower generation is one of important alternative energy, and enormous potential lie in the small hydropower. However, efficiency of small hydroturbines is lower than that of large one. Then, there are demands for small hydroturbines to keep high performance in wide flow rate range. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance. In this research, performance of the contra-rotating small hydroturbine with 60mm casing diameter was investigated by an experiment and numerical analysis. Efficiency of the contra-rotating small hydroturbine was high in pico-hydroturbine and high efficiency could be kept in wide flow rate range, however the performance of a rear rotor decreased significantly in partial flow rates. Then, internal flow condition, which was difficult to measure experimentally, was investigated by the numerical flow analysis. Then, a relation between the performance and internal flow condition was considered by the numerical analysis result.

Application of face centred central composite design to optimise compression force and tablet diameter for the formulation of mechanically strong and fast disintegrating orodispersible tablets.

PubMed

Pabari, Ritesh M; Ramtoola, Zebunnissa

2012-07-01

A two factor, three level (3(2)) face centred, central composite design (CCD) was applied to investigate the main and interaction effects of tablet diameter and compression force (CF) on hardness, disintegration time (DT) and porosity of mannitol based orodispersible tablets (ODTs). Tablet diameters of 10, 13 and 15 mm, and CF of 10, 15 and 20 kN were studied. Results of multiple linear regression analysis show that both the tablet diameter and CF influence tablet characteristics. A negative value of regression coefficient for tablet diameter showed an inverse relationship with hardness and DT. A positive value of regression coefficient for CF indicated an increase in hardness and DT with increasing CF as a result of the decrease in tablet porosity. Interestingly, at the larger tablet diameter of 15 mm, while hardness increased and porosity decreased with an increase in CF, the DT was resistant to change. The optimised combination was a tablet of 15 mm diameter compressed at 15 kN showing a rapid DT of 37.7s and high hardness of 71.4N. Using these parameters, ODTs containing ibuprofen showed no significant change in DT (ANOVA; p>0.05) irrespective of the hydrophobicity of the ibuprofen. Copyright © 2012 Elsevier B.V. All rights reserved.

Probe for Sampling of Interstitial Fluid From Bone

NASA Technical Reports Server (NTRS)

Janle, Elsa M.

2004-01-01

An apparatus characterized as both a membrane probe and a bone ultrafiltration probe has been developed to enable in vivo sampling of interstitial fluid in bone. The probe makes it possible to measure the concentration of calcium and other constituents of the fluid that may be relevant to bone physiology. The probe could be especially helpful in experimental studies of microgravitational bone loss and of terrestrial bone-loss disease states, including osteoporosis. The probe can be implanted in the bone tissue of a living animal and can be used to extract samples of the interstitial bone fluid from time to time during a long-term study. The probe includes three 12-cm-long polyacrylonitrile fibers configured in a loop form and attached to polyurethane tubing [inside diameter 0.025 in. (0.64 mm), outside diameter 0.040 in. (1 mm)]; the attachment is made by use of a 1-cm-long connecting piece of polyurethane tubing [inside diameter 0.035 0.003 in. (0.89 0.08 mm), outside diameter 0.060 0.003 in. (1.52 0.08 mm)]. At the distal end, a 2-cm-long piece of polyurethane tubing of the same inner and outer diameters serves as a connector to a hub. A 1-cm long piece of expanded poly (tetrafluoroethylene) tubing over the joint between the fibers and the connecting tubing serves as a tissue-in-growth site.

A low cost adaptive silicone membrane lens

NASA Astrophysics Data System (ADS)

Schneider, F.; Müller, C.; Wallrabe, U.

2008-04-01

This article introduces adaptive liquid lenses with thick silicone membranes of 5 mm diameter. These membranes are produced by means of casting in a batch process. The lenses feature an integrated piezo-bending actuator, which is also embedded in silicone. The lenses presented comprise areas of application which are not covered by the electrowetting lenses (diameter <3 mm) already established on the market.

Evaluating the risk of eye injuries: intraocular pressure during high speed projectile impacts.

PubMed

Duma, Stefan M; Bisplinghoff, Jill A; Senge, Danielle M; McNally, Craig; Alphonse, Vanessa D

2012-01-01

To evaluate the risk of eye injuries by determining intraocular pressure during high speed projectile impacts. A pneumatic cannon was used to impact eyes with a variety of projectiles at multiple velocities. Intraocular pressure was measured with a small pressure sensor inserted through the optic nerve. A total of 36 tests were performed on 12 porcine eyes with a range of velocities between 6.2 m/s and 66.5 m/s. Projectiles selected for the test series included a 6.35  mm diameter metal ball, a 9.25  mm diameter aluminum rod, and an 11.16  mm diameter aluminum rod. Experiments were designed with velocities in the range of projectile consumer products such as toy guns. A range of intraocular pressures ranged between 2017 mmHg to 26,426 mmHg (39 psi-511 psi). Four of the 36 impacts resulted in globe rupture. Intraocular pressures dramatically above normal physiological pressure were observed for high speed projectile impacts. These pressure data provide critical insight to chronic ocular injuries and long-term complications such as glaucoma and cataracts.

[Inspecting the cochlear scala tympanic with flexible and semi-flexible micro-endoscope].

PubMed

Zhang, Daoxcing; Zhang, Yankun

2006-02-01

Flexible and semi-flexible micro-endoscopes were used in cochlear scala tympani inspection , to explore their application in inner ear examination. Fifteen profound hearing loss patients preparing for cochlear implant were included in this study. During the operation, micro-endoscopy was performed after opening the cochlear scala tympani. And 1 mm diameter semi-flexible micro-endoscope could go as deep as 9 mm into the cochlear scala tympani, while 0. 5 mm diameter flexible micro-endoscope could go as deep as 25 mm. The inspecting results were compared with video recording. Using 0.5 mm flexible micro-endoscope, we canould check cochlear scala tympani with depth range of 15-25 mm, but the video imaging was not clear enough to examine the microstructure in the cochlear. With 1 mm diameter semi-flexible micro-endoscope, we could reach 9 mm deep into the cochlear. During the examination, we found 3 cases with calcification deposit in osseous spiral lamina, l case with granulation tissue in the lateral wall of scala tympani, no abnormal findings in the other 11 cases. Inspecting the cochlear scala tympani with 0.5 mm flexible micro-endoscope, even though we can reach the second circuit of the cochlear, it is difficult to find the pathology in the cochlear because of the poor video imaging. With 1 mm semi-flexible micro-endoscope, we can identify the microstructure of the cochlear clearly and find the pathologic changes, but the inserting depth was limited to 9 mm with limitation to examine the whole cochlear.

Enhanced MicroChannel Heat Transfer in Macro-Geometry using Conventional Fabrication Approach

NASA Astrophysics Data System (ADS)

Ooi, KT; Goh, AL

2016-09-01

This paper presents studies on passive, single-phase, enhanced microchannel heat transfer in conventionally sized geometry. The intention is to allow economical, simple and readily available conventional fabrication techniques to be used for fabricating macro-scale heat exchangers with microchannel heat transfer capability. A concentric annular gap between a 20 mm diameter channel and an 19.4 mm diameter insert forms a microchannel where heat transfer occurs. Results show that the heat transfer coefficient of more than 50 kW/m·K can be obtained for Re≈4,000, at hydraulic diameter of 0.6 mm. The pressure drop values of the system are kept below 3.3 bars. The present study re-confirms the feasibility of fabricating macro-heat exchangers with microchannel heat transfer capability.

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

PubMed

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

2012-10-08

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

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy

PubMed Central

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

2012-01-01

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

Effect of fiber diameter and matrix alloys on impact-resistant boron/aluminum composites

NASA Technical Reports Server (NTRS)

Mcdanels, D. L.; Signorelli, R. A.

1976-01-01

Efforts to improve the impact resistance of B/Al are reviewed and analyzed. Nonstandard thin-sheet charpy and Izod impact tests and standard full-size Charpy impact tests were conducted on composites containing unidirectional 0.10mm, 0.14mm, and 0.20mm diameter boron fibers in 1100, 2024, 5052, and 6061 Al matrices. Impact failure modes of B/Al are proposed in an attempt to describe the mechanisms involved and to provide insight for maximizing impact resistance. The impact strength of B/Al was significantly increased by proper selection of materials and processing. The use of a ductile matrix and large diameter boron fibers gave the highest impact strengths. This combination resulted in improved energy absorption through matrix shear deformation and multiple fiber breakage.

Catalyzed Ignition of Bipropellants in Microtubes

NASA Technical Reports Server (NTRS)

Schneider, Steven J.; Boyarko, George A.; Sung, Chih-Jen

2003-01-01

This paper addresses the need to understand the physics and chemistry involved in propellant combustion processes in micro-scale combustors for propulsion systems on micro-spacecraft. These spacecraft are planned to have a mass less than 50 kilograms with attitude control estimated to be in the 10 milli-Newton thrust class. These combustors are anticipated to be manufactured using Micro Electrical Mechanical Systems (MEMS) technology and are expected to have diameters approaching the quenching diameter of the propellants. Combustors of this size are expected to benefit significantly from surface catalysis processes. Miniature flame tube apparatus is chosen for this study because microtubes can be easily fabricated from known catalyst materials and their simplicity in geometry can be used in fundamental simulations to more carefully characterize the measured heat transfer and pressure losses for validation purposes. Experimentally, we investigate the role of catalytically active surfaces within 0.4 and 0.8 mm internal diameter micro-tubes, with special emphases on ignition and extinction processes in fuel rich gaseous hydrogen and gaseous oxygen. Flame thickness and reaction zone thickness calculations predict that the diameters of our test apparatus are below the quenching diameter of the propellants in sub-atmospheric tests. Temperature and pressure rises in resistively heated platinum and palladium micro-tubes are used as an indication of exothermic reactions. Specific data on mass flow versus preheat temperature required to achieve ignition are presented.

A rare case of large isolated internal iliac artery aneurysm with ureteral obstruction and hydronephrosis: Compression symptoms are limitation for endovascular procedures.

PubMed

Nenezic, Dragoslav; Tanaskovic, Slobodan; Gajin, Predrag; Ilijevski, Nenad; Novakovic, Aleksandra; Radak, Djordje

2015-04-01

In this report, we aim to present a rare case of isolated internal iliac artery aneurysm with associated left ureteric obstruction and consequent hydronephrosis. A 66-year-old male patient was admitted for occasional pain in the lower back that appeared one month earlier. CT arteriography revealed isolated internal iliac artery (diameter 99 mm) with ureteral obstruction, hydroureter and left kidney hydronephrosis occurrence. Aneurysm was resected, after six months the patient was doing well. Bearing in mind that 77% of the patients with isolated internal iliac artery have symptoms caused by aneurysmal compression on adjacent organs, we wanted to highlight that despite the amazing expansion of endovascular procedures in the last decades, its therapeutic effect in isolated internal iliac artery's treatment is to a great extent limited since compression symptoms cannot be solved. Open surgery remains the gold standard for isolated internal iliac artery's treatment considering significant limitations of endovascular procedures due to the inability to eliminate problems caused by compression. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Three-dimensional growth dynamics of the liver in the human fetus.

PubMed

Szpinda, Michał; Paruszewska-Achtel, Monika; Woźniak, Alina; Badura, Mateusz; Mila-Kierzenkowska, Celestyna; Wiśniewski, Marcin

2015-07-01

The fetal liver is indubitably the earliest and the most severely affected organ by abnormal fetal growth. The size of the fetal liver assessed by three-dimensional ultrasonography is indispensable in determining the status of fetal growth, nutrition and maturity, and in the early recognition and monitoring fetal micro- and macrosomias. The aim of the present study was to measure the human fetal liver length, transverse and sagittal diameters to establish their age-specific reference intervals, the 3rd, 10th, 50th, 90th, and 97th smoothed centile curves, and the relative growth of the liver calculated for the 50th centile. Using anatomical, digital (NIS-Elements AR 3.0, Nikon) and statistical methods (one-way ANOVA test for paired data and post hoc RIR Tukey test, Shapiro-Wilk test, Fisher's test, Student's t test, the Altman-Chitty method), length, transverse and sagittal diameters of the liver for the 3rd, 10th, 50th, 90th, and 97th centiles were assessed in 69 human fetuses of both sexes (32 males and 37 females) aged 18-30 weeks, derived from spontaneous abortions or stillbirths. No male-female differences (P > 0.05) concerning the three parameters studied were found. During the study period, the fetal liver increased tri-dimensionally: in length from 19.51 ± 1.02 to 39.65 ± 7.05 mm, in transverse diameter from 29.44 ± 3.73 to 53.13 ± 5.31 mm, and in sagittal diameter from 22.97 ± 3.79 to 43.22 ± 5.49 mm. The natural logarithmic models were found to fit the data with gestational age (P < 0.001) in the following five cutoff points: 3rd, 10th, 50th, 90th and 97th centiles. The values of liver parameters in relation to gestational age in weeks were calculated by the following logarithmic regressions: y = -82.778 + 35.752 × ln(age) ± Z × (-2.778 + 0.308 × age) for liver length, y = -123.06 + 52.668 × ln(age) ± Z × (3.156 + 0.049 × age) for liver transverse diameter, and y = -108.94 + 46.052 × ln(age) ± Z × (-0.541 + 0.188 × age) for liver sagittal diameter. For the 50th centile, at the range of 18-30 weeks, the growth rates per week were gradually decreasing from 1.93 to 1.21 mm for length, from 2.85 to 1.79 mm for transverse diameter, and from 2.49 to 1.56 mm for sagittal diameter of the liver (P < 0.05). During the study period both the length-to-transverse diameter ratio and the sagittal-to-transverse diameter ratio of the liver changed little, attaining the values of 0.71 ± 0.11 and 0.87 ± 0.12, respectively. The fetal liver does not reveal sex differences in its length, transverse and sagittal diameters. The fetal liver length, transverse and sagittal diameters grow logarithmically. The regression equations for the estimation of the mean and standard deviation of liver length, transverse and sagittal diameters allow for calculating any desired centiles according to gestational age. The three-dimensional evolution of the fetal liver follows proportionately. The age-specific reference intervals for evolving liver length, transverse and sagittal diameters constitute the normative values of potential relevance in monitoring normal fetal development and screening for disturbances in fetal growth.

Piezoelectric ultrasonic micromotor with 1.5 mm diameter.

PubMed

Dong, Shuxiang; Lim, Siak P; Lee, Kwork H; Zhang, Jingdong; Lim, Leong C; Uchino, Kenji

2003-04-01

A piezoelectric ultrasonic micromotor has been developed using a lead zirconate titanate (PZT) ceramic/metal composite tube stator that was 1.5 mm in diameter and 7 mm in length. The micromotor was operated in its first bending vibration mode (approximately 70 kHz), producing speeds from hundreds to over 2000 rpm in both rotational directions. The maximum torque-output was 45 microN-m, which is far superior to previous PZT thin film-based micromotors. This micromotor showed good reliability and stability for more than 300 hours of continued operation.

Corneal Thickness Profile and Associations in Chinese Children Aged 7 to 15 Years Old.

PubMed

Ma, Yingyan; Zhu, Xiaofeng; He, Xiangui; Lu, Lina; Zhu, Jianfeng; Zou, Haidong

2016-01-01

Corneal thickness (CT) maps of the central (2-mm diameter), para-central (2 to 5-mm diameter), peripheral (5 to 6-mm diameter), and minimum (5-mm diameter) cornea were measured in normal Chinese school children aged 7 to 15 years old using Fourier-domain optical coherence tomography. Multiple regression analyses were performed to explore the effect of associated factors [age, gender, refraction, axial length and corneal curvature radius (CCR)] on CT and the relationship between central corneal thickness (CCT) and intraocular pressure (IOP). A total of 1228 eyes from 614 children were analyzed. The average CCT was 532.96 ± 28.33 μm for right eyes and 532.70 ±28.45 μm for left eyes. With a 10 μm increase in CCT, the IOP was elevated by 0.37 mm Hg, as measured by noncontact tonometry. The CT increased gradually from the center to the periphery. The superior and superior nasal regions had the thickest CTs, while the thinnest points were primarily located in the inferior temporal cornea. The CCT was associated with CCR (p = 0.008) but not with gender (p = 0.075), age (p = 0.286), axial length (p = 0.405), or refraction (p = 0.985). In the para-central region and the peripheral cornea, increased CT was associated with younger age, male gender, and a flatter cornea.

Efficacy of a Novel Narrow Knife with Water Jet Function for Colorectal Endoscopic Submucosal Dissection.

PubMed

Yoshida, Naohisa; Toyonaga, Takashi; Murakami, Takaaki; Hirose, Ryohei; Ogiso, Kiyoshi; Inada, Yutaka; Rani, Rafiz Abdul; Naito, Yuji; Kishimoto, Mitsuo; Ohara, Yoshiko; Azuma, Takeshi; Itoh, Yoshito

2017-01-01

With respect to the knife's design in colorectal endoscopic submucosal dissection (ESD), diameter, water jet function, and electric power are important because these relate to efficient dissection. In this study, we analyzed a novel, narrow ball tip-typed ESD knife with water jet function (Flush knife BT-S, diameter: 2.2 mm, length: 2000 mm, Fujifilm Co., Tokyo, Japan) compared to a regular diameter knife (Flush knife BT, diameter: 2.6 mm, length: 1800 mm). In laboratory and clinical research, electric power, knife insertion time, vacuum/suction amount with knife in the endoscopic channel, and water jet function were analyzed. We used a knife 2.0 mm long for BT-S and BT knives. The BT-S showed faster mean knife insertion time (sec) and better vacuum amount (ml/min) compared to the BT (insertion time: 16.7 versus 21.6, p < 0.001, vacuum amount: 38.0 versus 14.0, p < 0.01). Additionally, the water jet function of the BT-S was not inferior. In 39 colorectal ESD cases in two institutions, there were mean 4.7 times (range: 1-28) of knife insertion. Suction under knife happened 59% (23/39) and suction of fluid could be done in 100%. Our study showed that the narrow knife allows significantly faster knife insertion, better vacuum function, and effective clinical results.

Hydrodynamic flow in capillary-channel fiber columns for liquid chromatography.

PubMed

Stanelle, Rayman D; Sander, Lane C; Marcus, R Kenneth

2005-12-23

The flow characteristics of capillary-channel polymer (C-CP) fiber liquid chromatographic (LC) columns have been investigated. The C-CP fibers are manufactured with eight longitudinal grooves (capillary channels) extending the length of the fibers. Three C-CP fiber examples were studied, with fiber dimensions ranging from approximately 35 microm to 65 microm, and capillary-channel dimensions ranging from approximately 6 microm to 35 microm. The influence of fiber packing density and column inner diameter on peak asymmetry, peak width, and run-to-run reproducibility have been studied for stainless steel LC columns packed with polyester (PET) and polypropylene (PP) C-CP fibers. The van Deemter A-term was evaluated as a function of fiber packing density (approximately 0.3 g/cm(3)-0.75 g/cm(3)) for columns of 4.6 mm inner diameter (i.d.) and at constant packing densities for 1.5 mm, 3.2 mm, 4.6 mm, and 7.7 mm i.d. columns. Although column diameter had little influence on the eluting peak widths, peak asymmetry increased with increasing column diameter. The A-terms for the C-CP fiber packed columns are somewhat larger than current commercial, microparticulate-packed columns, and means for improvement are discussed. Applications in the area of protein (macromolecule) separations appear the most promising at this stage of the system development.

What do sales data tell us about implant survival?

PubMed

Seemann, Rudolf; Jirku, Alexander; Wagner, Florian; Wutzl, Arno

2017-01-01

The aim of this study was to evaluate the influence of implant diameter, length and shape on a surrogate parameter of implant survival; i.e. the implant return rate in a big data analysis. A retrospective study was conducted and the factors influencing the success rates of 69,377 sold implants over a seven-year period were evaluated. The osseointegration program of a reseller provides reliable data of a single country. Implant loss rates were investigated using logistic regression models and regressed by implant type, diameter, and length. The return rate of 69,377 sold implants was 2.78% and comparable to implant loss rates in previous published prospective studies as its surrogate parameter. A total of 80% of implant returns had occurred within 157 days, and an additional 15% within 750.25 days. Diameters of 3.8 to 5.0mm showed the lowest return rates with its bottom in the 4.3mm implant whilst 6.0mm implants had significantly higher return rates. In comparison to the most sold implant length (13mm) shorter implants showed significantly higher early return rates. The study provides evidence that in cases of standard indications and sufficient bone, the use of screw typed dental implants with 3.8 or 4.3 diameter and 11 or 13 mm length shows the lowest implant return rates. Other implants may be selected only in specific indications.

Risk factors associated with delayed gastric emptying after subtotal gastrectomy with Billroth-I anastomosis using circular stapler for early gastric cancer patients

PubMed Central

Kim, Ki Han; Jung, Ghap Joong

2012-01-01

Purpose Gastric surgery may potentiate delayed gastric emptying. Billroth I gastroduodenostomy using a circular stapler is the most preferable reconstruction method. The purpose of this study is to analyze the risk factors associated with delayed gastric emptying after radical subtotal gastrectomy with Billroth I anastomosis using a stapler for early gastric cancer. Methods Three hundred and seventy-eight patients who underwent circular stapled Billroth I gastroduodenostomy after subtotal gastrectomy due to early gastric cancer were analyzed retrospectively. One hundred and eighty-two patients had Billroth I anastomosis using a 25 mm diameter circular stapler, and 196 patients had anastomosis with a 28 or 29 mm diameter circular stapler. Clinicopathological features and postoperative outcomes were evaluated and compared between the two groups. Delayed gastric emptying was diagnosed by symptoms and simple abdomen X-ray with or without upper gastrointestinal series or endoscopy. Results Postoperative delayed gastric emptying was found in 12 (3.2%) of the 378 patients. Among all the variables, distal margin and circular stapler diameter were significantly different between the cases with delayed gastric emptying and no delayed gastric emptying. There were statistically significant differences in sex, body mass index, comorbidity, complication, and operation type according to circular stapler diameter. In both univariate and multivariate logistic regression analyses, only the stapler diameter was found to be a significant factor affecting delayed gastric emptying (P = 0.040). Conclusion In this study, the circular stapler diameter was one of the most significant predictable factors of delayed gastric emptying for Billroth I gastroduodenostomy. The use of a 28 or 29 mm diameter circular stapler rather than a 25 mm diameter stapler in stapled gastroduodenostomy for early gastric cancer can reduce postoperative delayed gastric emptying associated with anastomosic stenosis or edema with relative safety. PMID:23166886

Peri-implant soft tissue and marginal bone adaptation on implant with non-matching healing abutments: micro-CT analysis.

PubMed

Finelle, Gary; Papadimitriou, Dimitrios E V; Souza, André B; Katebi, Negin; Gallucci, German O; Araújo, Mauricio G

2015-04-01

To assess (i) the outcome of changing the horizontal-offset dimension on the peri-implant soft tissues and the crestal bone and (ii) the effect of different healing abutments (flared vs. straight) on the marginal peri-implant soft tissues and crestal bone. Two-piece dental implants diameters of 3.5 and 4.5 mm were placed at least 1 mm subcrestal in five beagle dogs. Three different investigational groups: (i) 3.5-mm-diameter implant with narrow healing abutment (3.5N), (ii) 4.5-mm-diameter implant with narrow healing abutment (4.5N), and (iii) 3.5-mm-diameter implant with wide healing abutment (3.5W), were assessed. After 4 months of healing, the vertical distance from the marginal crestal bone (MB) to the implant shoulder (IS); the vertical distance from the IS to the first bone-to-implant contact; and the horizontal distance of bone ingrowth on the implant platform were measured with a high-resolution micro-CT (Xradia MicroXCT-200 system). Implants with a narrow healing caps showed an interproximal MB located between 0 and 1 mm above the implant shoulder, while the 3.5W group exhibits a mean value -0.50 mm. As all implants in group 3.5N presented a fBIC located at the level of the IS. For the 4.5N group, the mean fBIC-IS distance was -0.52 mm apically to the IS. For the 3.5WC group, the mean fBIC-IS distance was -1.42 mm. Horizontal bone apposition was only observed for the 3.5N group and the 4.5N group. The dimension of the horizontal offset would play a minimal role in reducing bone remodeling, whereas the configuration of the transmucosal component would directly influence marginal bone remodeling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Safety of Percutaneous Patent Ductus Arteriosus Closure: An Unselected Multicenter Population Experience

PubMed Central

El‐Said, Howaida G.; Bratincsak, Andras; Foerster, Susan R.; Murphy, Joshua J.; Vincent, Julie; Holzer, Ralf; Porras, Diego; Moore, John; Bergersen, Lisa

2013-01-01

Background The technique and safety of transcatheter patent ductus arteriosus (PDA) closure have evolved during the past 20 years. We sought to report a multicenter experience of PDA closure with a focus on the rate of adverse events (AE) and a review of institutional practice differences. Methods and Results Outcome data on transcatheter PDA closure were collected at 8 centers prospectively using a multicenter registry (Congenital Cardiac Catheterization Project on Outcome Registry). Between February 2007 and June 2010, 496 PDA closures were recorded using a device in 338 (68%) or coils in 158 (32%). Most patients had an isolated PDA (90%). Fifty percent of patients were between 6 months and 3 years old, with only 40 patients (8%) <6 months old. Median minimum PDA diameter was 2.5 mm (range 1 to 12 mm; IQR 2 to 3 mm) for device closure and 1 mm (range 0.5 to 6 mm; IQR 1 to 2 mm) for coil closure (P<0.001). A device rather than coil was used in patients <3 years, weight <11 kg, and with a PDA minimum diameter >2 mm (all P<0.001). Three of 8 centers exclusively used a device for PDAs with a diameter >1.5 mm. In 9% of cases (n=46), an AE occurred; however, only 11 (2%) were classified as high severity. Younger age was associated with a higher AE rate. Coil‐related AEs were more common than device‐related AEs (10% versus 2%, P<0.001). Conclusions PDA closure in the present era has a very low rate of complications, although these are higher in younger children. Technical intervention‐related events were more common in coil procedures compared with device procedures. For PDAs ≤2.5 mm in diameter, institutional differences in preference for device versus coil exist. PMID:24284214

The high velocity, high adiabat, "Bigfoot" campaign and tests of indirect-drive implosion scaling

NASA Astrophysics Data System (ADS)

Casey, D. T.; Thomas, C. A.; Baker, K. L.; Spears, B. K.; Hohenberger, M.; Khan, S. F.; Nora, R. C.; Weber, C. R.; Woods, D. T.; Hurricane, O. A.; Callahan, D. A.; Berger, R. L.; Milovich, J. L.; Patel, P. K.; Ma, T.; Pak, A.; Benedetti, L. R.; Millot, M.; Jarrott, C.; Landen, O. L.; Bionta, R. M.; MacGowan, B. J.; Strozzi, D. J.; Stadermann, M.; Biener, J.; Nikroo, A.; Goyon, C. S.; Izumi, N.; Nagel, S. R.; Bachmann, B.; Volegov, P. L.; Fittinghoff, D. N.; Grim, G. P.; Yeamans, C. B.; Gatu Johnson, M.; Frenje, J. A.; Rice, N.; Kong, C.; Crippen, J.; Jaquez, J.; Kangas, K.; Wild, C.

2018-05-01

The Bigfoot approach is to intentionally trade off high convergence, and therefore areal-density, in favor of high implosion velocity and good coupling between the laser, hohlraum, shell, and hotspot. This results in a short laser pulse that improves hohlraum symmetry and predictability, while the reduced compression reduces hydrodynamic instability growth. The results thus far include demonstrated low-mode symmetry control at two different hohlraum geometries (5.75 mm and 5.4 mm diameters) and at two different target scales (5.4 mm and 6.0 mm hohlraum diameters) spanning 300-405 TW in laser power and 0.8-1.6 MJ in laser energy. Additionally, by carefully scaling the 5.4 mm design to 6.0 mm, an increase in target scale of 13%, equivalent to 40% increase in laser energy, has been demonstrated.

Reference range of fetal transverse cerebellar diameter between 18 and 24 weeks of pregnancy in a Brazilian population.

PubMed

Araujo Júnior, Edward; Martins, Wellington P; Nardozza, Luciano Marcondes Machado; Pires, Claudio Rodrigues; Filho, Sebastião Marques Zanforlin

2015-02-01

To determine a reference range of fetal transverse cerebellar diameter in Brazilian population. This was a retrospective cross-sectional study with 3772 normal singleton pregnancies between 18 and 24 weeks of pregnancy. The transverse cerebellar diameter was measured on the axial plane of the fetal head at the level of the lateral ventricles, including the thalamus, cavum septum pellucidum, and third ventricle. To assess the correlation between transverse cerebellar diameter and gestational age, polynomial equations were calculated, with adjustments by the determination coefficient (R2). The mean of fetal transverse cerebellar diameter ranged from 18.49 ± 1.24 mm at 18 weeks to 25.86 ± 1.66 mm at 24 weeks of pregnancy. We observed a good correlation between transverse cerebellar diameter and gestational age, which was best represented by a linear equation: transverse cerebellar diameter: -6.21 + 1.307*gestational age (R2 = 0.707). We determined a reference range of fetal transverse cerebellar diameter for the second trimester of pregnancy in Brazilian population. © The Author(s) 2014.

Internal sphincter and the nature of haemorrhoids.

PubMed Central

Hancock, B D

1977-01-01

Internal anal sphincter activity has been studied in 84 patients with haemorrhoids and 40 asymptomatic subjects. Activity was estimated by measuring maximum resting anal pressure with a water filled anal balloon probe 7 mm in diameter connected to a strain gauge pressure transducer. There was greater activity of the internal sphincter in patients with haemorrhoids than in controls, but there was no significant relationship between sphincter activity and duration of symptoms, predominant symptom (bleeding or prolapse), severity of symptoms, history of pain, history of straining at stool, or size of haemorrhoids. Straining at stool occurred significantly more often in patients whose main complaint was prolapse than in those whose main complaint was bleeding. Anal dilatation reduced sphincter activity and the best clinical results were obtained in those with the most active sphincter. An internal sphincter abnormality may be an aetiological factor in some patients but there must be other factors as well. Straining at stool may determine whether bleeding or prolapse is the predominant symptom. Images Fig. 1 PMID:892612

A new corrective technique for adolescent idiopathic scoliosis: convex manipulation using 6.35 mm diameter pure titanium rod followed by concave fixation using 6.35 mm diameter titanium alloy

PubMed Central

2015-01-01

Background It has been thought that corrective posterior surgery for adolescent idiopathic scoliosis (AIS) should be started on the concave side because initial convex manipulation would increase the risk of vertebral malrotation, worsening the rib hump. With the many new materials, implants, and manipulation techniques (e.g., direct vertebral rotation) now available, we hypothesized that manipulating the convex side first is no longer taboo. Methods Our technique has two major facets. (1) Curve correction is started from the convex side with a derotation maneuver and in situ bending followed by concave rod application. (2) A 6.35 mm diameter pure titanium rod is used on the convex side and a 6.35 mm diameter titanium alloy rod on the concave side. Altogether, 52 patients were divided into two groups. Group N included 40 patients (3 male, 37 female; average age 15.9 years) of Lenke type 1 (23 patients), type 2 (2), type 3 (3), type 5 (10), type 6 (2). They were treated with a new technique using 6.35 mm diameter different-stiffness titanium rods. Group C included 12 patients (all female, average age 18.8 years) of Lenke type 1 (6 patients), type 2 (3), type 3 (1), type 5 (1), type 6 (1). They were treated with conventional methods using 5.5 mm diameter titanium alloy rods. Radiographic parameters (Cobb angle/thoracic kyphosis/correction rates) and perioperative data were retrospectively collected and analyzed. Results Preoperative main Cobb angles (groups N/C) were 56.8°/60.0°, which had improved to 15.2°/17.1° at the latest follow-up. Thoracic kyphosis increased from 16.8° to 21.3° in group N and from 16.0° to 23.4° in group C. Correction rates were 73.2% in group N and 71.7% in group C. There were no significant differences for either parameter. Mean operating time, however, was significantly shorter in group N (364 min) than in group C (456 min). Conclusion We developed a new corrective surgical technique for AIS using a 6.35 mm diameter pure titanium rod initially on the convex side. Correction rates in the coronal, sagittal, and axial planes were the same as those achieved with conventional methods, but the operation time was significantly shorter. PMID:25815053

Calcified aquatic insect larval constructions in the Pleistocene tufa of Jebel El Mida, Gafsa, southern Tunisia: Recognition and paleoenvironmental significance

NASA Astrophysics Data System (ADS)

Ben Ahmed, Walid; Henchiri, Mohsen; Mastouri, Amna; Slim S'himi, Najet

2018-04-01

Calcified aquatic larval cases were recognized and identified in the Pleistocene tufa masses of Jebel El Mida, Gafsa, southern Tunisia. These larval constructions belong to three main insect families: caddisflies (Trichoptera, Hydropsychidae), midges (Diptera, Chironomidae) and aquatic moths (Lepidoptera, Pyralidae) that inhabited tubes in the tufa and spun nets. Each insect community has its distinctive characteristics of larval constructions that allow their recognition. The larval constructions recognized comprise fixed and portable (for caddisflies) dwelling cases and silken retreats and feeding capture nets. These last-mentioned are almost completely eroded and only remnants are preserved. The spatial distribution of these larval cases within the tufa is not random but, rather imposed by some specific paleohydraulic conditions. It's the reason why aquatic insect larval constructions are considered as prominent tool for the reconstruction of tufa and travertine depositional environments. Chironomid fixed dwelling cases (diameters range from 0.6 mm for clustered tubes to 3 mm) indicate the deposition of tufa under lotic (flowing) or lentic (standing) water conditions. The later hydraulic condition is shared with hydropsychids with fixed retreats (0.2-4 mm in diameter). Portable case-building caddisflies (case length ranging from 5 to 20 mm, and diameter from 3 to 5 mm at the cephalic end) prefer lentic conditions and are almost completely missing in high-energy flowing water locations that are preferred by pyralids (tubes are between 5 and 10 mm long and 3 mm in diameter). These insect families benefit from inhabiting the tufa by the availability of construction materials of their cases and the necessary space for their development.

Process influences and correction possibilities for high precision injection molded freeform optics

NASA Astrophysics Data System (ADS)

Dick, Lars; Risse, Stefan; Tünnermann, Andreas

2016-08-01

Modern injection molding processes offer a cost-efficient method for manufacturing high precision plastic optics for high volume applications. Besides form deviation of molded freeform optics, internal material stress is a relevant influencing factor for the functionality of a freeform optics in an optical system. This paper illustrates dominant influence parameters of an injection molding process relating to form deviation and internal material stress based on a freeform demonstrator geometry. Furthermore, a deterministic and efficient way for 3D mold correcting of systematic, asymmetrical shrinkage errors is shown to reach micrometer range shape accuracy at diameters up to 40 mm. In a second case, a stress-optimized parameter combination using unusual molding conditions was 3D corrected to reach high precision and low stress freeform polymer optics.

[Melanosis maculosa in a calf].

PubMed

Camenzind, D; Winzap, B; Hässig, M

2003-07-01

This work describes findings in a fattened calf, which were seen in a routine slaughter. The most important findings by the meat inspector were diffuse, black spots between 2 and 70 mm in diameter. This hyperpigmentation was observed on the entire carcass as well as on the outside and inside of all internal organs. Removal of the spinal cord produced black colored liquor. Subsequent microbiological examination of the meat resulted in sterile findings. The muscle pH was 5.8. On histological examination many macrophages containing melanin were found in the lung and liver. Based on these findings the diagnosis of Melanosis maculosa was made.

Surface acoustic wave solid-state rotational micromotor

NASA Astrophysics Data System (ADS)

Shilton, Richie J.; Langelier, Sean M.; Friend, James R.; Yeo, Leslie Y.

2012-01-01

Surface acoustic waves (SAWs) are used to drive a 1 mm diameter rotor at speeds exceeding 9000 rpm and torque of nearly 5 nNm. Unlike recent high-speed SAW rotary motors, however, the present design does not require a fluid coupling layer but interestingly exploits adhesive stiction as an internal preload, a force usually undesirable at these scales; with additional preloads, smaller rotors can be propelled to 15 000 rpm. This solid-state motor has no moving parts except for the rotor and is sufficiently simple to allow integration into miniaturized drive systems for potential use in microfluidic diagnostics, optical switching and microrobotics.

Supercooling Water in Cylindrical Capsules

NASA Astrophysics Data System (ADS)

Guzman, J. J. Milón; Braga, S. L.

2005-11-01

An experimental apparatus was developed to investigate the supercooling phenomenon of water inside cylindrical capsules used for a cold storage process. The coolant is a water-alcohol mixture controlled by a constant temperature bath (CTB). Temperatures varying with time are measured inside and outside the capsule. Cylinders with an internal diameter and thickness of 45 and 1.5 mm, respectively, were made from four different materials: acrylic, PVC, brass, and aluminum. The supercooling period of the water and the nucleation temperature were investigated for different coolant temperatures. The supercooling and nucleation probabilities are shown as a function of the coolant temperature for the four different materials.

Effects of Pin Detached Space on Heat Transfer in a Rib Roughened Channel

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

Siw, Sin Chien; Chyu, Minking K.; Alvin, Mary Anne

2012-11-08

An experimental study is performed to investigate the heat transfer characteristics and frictional losses in a rib roughened channel combined with detached pin-fins. The overall channel geometry (W=76.2 mm, E=25.4 mm) simulates an internal cooling passage of wide aspect ratio (3:1) in a gas turbine airfoil. With a given pin diameter, D=6.35 mm=[1/4]E, three different pin-fin height-to-diameter ratios, H/D=4, 3, and 2, were examined. Each of these three cases corresponds to a specific pin array geometry of detachment spacing (C) between the pin-tip and one of the endwalls, i.e., C/O=0, 1, 2, respectively. The rib height-to-channel height ratio is 0.0625.more » Two newly proposed cross ribs, namely the broken rib and full rib are evaluated in this effort. The broken ribs are positioned in between two consecutive rows of pin-fins, while the full ribs are fully extended adjacent to the pin-fins. The Reynolds number, based on the hydraulic diameter of the unobstructed cross section and the mean bulk velocity, ranges from 10,000 to 25,000. The experiment employs a hybrid technique based on transient liquid crystal imaging to obtain distributions of the local heat transfer coefficient over all of the participating surfaces, including the endwalls and all pin elements. The presence of ribs enhances local heat transfer coefficient on the endwall substantially by approximately 20% to 50% as compared to the neighboring endwall. In addition, affected by the rib geometry, which is a relatively low profile as compared to the overall height of the channel, the pressure loss seems to be insensitive to the presence of the ribs. However, from the overall heat transfer enhancement standpoint, the baseline cases (without ribs) outperform cases with broken ribs or full ribs.« less

6D.03: FLOW-MEDIATED DILATATION (FMD) AND ENDOTHELIUM-INDEPENDENT DILATATION (EID) IN PATIENTS WITH MULTIFOCAL FIBROMUSCULAR DYSPLASIA: A CROSS-SECTIONAL STUDY.

PubMed

Khettab, H; Lorthior, A; Niarra, R; Chambon, Y; Jeunemaitre, X; Plouin, P F; Laurent, S; Boutouyrie, P; Azizi, M

2015-06-01

Fibromuscular dysplasia (FD) is a rare idiopathic, segmental, non-atherosclerotic non-inflammatory vascular disease. We previously showed that FD is a general arterial disease with focal exacerbation of the trait. However, whether endothelial dysfunction may be involved in the pathophysiology of FD is unclear. In a cross sectional study, we compared the endothelial function between 50 patients with multifocal FD of renal/carotid arteries confirmed by CT-angiography, 50 essential hypertensive (EH) patients matched for age, sex, ethnicity and BP and 50 healthy subjects (HS) matched for age, sex and ethnicity. Exclusion criteria were: tobacco consumption, hypercholesterolemia, diabetes, aspirin or statin treatment. Brachial artery (BA) FMD after release of hand ischemia and glyceryl trinitrate (GTN)-induced EID was measured using a high-resolution radiofrequency-based echotracking system blind to the diagnosis. FD, EH and HS were well matched (52yrs, 85% women, 80% caucasian). SBP was higher in FD (125 ± 15mmHg) and EH (121 ± 12mmHg) than EH (113 ± 10mmHg) despite antihypertensive treatments. BA external diameter was significantly lower in FD than in both HS and EH before, during and after hand ischemia and after GTN. BA intima media thickness (IMT), internal diameter did not differ between the 3 groups. FMD (%) or EID (%) did not significantly differ between the 3 groups. BA flow velocity did not significantly differ in any experimental condition.(Figure is included in full-text article.) : In conclusion, despite showing similar acute vasodilatory responses to flow and GTN, FD patients differed from EH and HS in terms of arterial morphology with smaller BA diameter associated with similar IMT. This paradoxical remodeling may suggest a chronic defect in the endothelium-dependent pathways involved in arterial remodeling in FD patients.

The structure optimization of gas-phase surface discharge and its application for dye degradation

NASA Astrophysics Data System (ADS)

Ying, CAO; Jie, LI; Nan, JIANG; Yan, WU; Kefeng, SHANG; Na, LU

2018-05-01

A gas-phase surface discharge (GSD) was employed to optimize the discharge reactor structure and investigate the dye degradation. A dye mixture of methylene blue, acid orange and methyl orange was used as a model pollutant. The results indicated that the reactor structure of the GSD system with the ratio of tube inner surface area and volume of 2.48, screw pitch between a high-voltage electrode of 9.7 mm, high-voltage electrode wire diameter of 0.8 mm, dielectric tube thickness of 2.0 mm and tube inner diameter of 16.13 mm presented a better ozone (O3) generation efficiency. Furthermore, a larger screw pitch and smaller wire diameter enhanced the O3 generation. After the dye mixture degradation by the optimized GSD system, 73.21% and 50.74% of the chemical oxygen demand (COD) and total organic carbon removal rate were achieved within 20 min, respectively, and the biochemical oxygen demand (BOD) and biodegradability (BOD/COD) improved.

Measurement and analysis of a small nozzle plume in vacuum

NASA Technical Reports Server (NTRS)

Penko, P. F.; Boyd, I. D.; Meissner, D. L.; Dewitt, K. J.

1993-01-01

Pitot pressures and flow angles are measured in the plume of a nozzle flowing nitrogen and exhausting to a vacuum. Total pressures are measured with Pitot tubes sized for specific regions of the plume and flow angles measured with a conical probe. The measurement area for total pressure extends 480 mm (16 exit diameters) downstream of the nozzle exit plane and radially to 60 mm (1.9 exit diameters) off the plume axis. The measurement area for flow angle extends to 160 mm (5 exit diameters) downstream and radially to 60 mm. The measurements are compared to results from a numerical simulation of the flow that is based on kinetic theory and uses the direct-simulation Monte Carlo (DSMC) method. Comparisons of computed results from the DSMC method with measurements of flow angle display good agreement in the far-field of the plume and improve with increasing distance from the exit plane. Pitot pressures computed from the DSMC method are in reasonably good agreement with experimental results over the entire measurement area.

Gravity-Independent Mobility and Drilling on Natural Rock using Microspines

NASA Technical Reports Server (NTRS)

Parness, Aaron; Frost, Matthew; Thatte, Nitish; King, Jonathan P.

2012-01-01

To grip rocks on the surfaces of asteroids and comets, and to grip the cliff faces and lava tubes of Mars, a 250 mm diameter omni-directional anchor is presented that utilizes a hierarchical array of claws with suspension flexures, called microspines, to create fast, strong attachment. Prototypes have been demonstrated on vesicular basalt and a'a lava rock supporting forces in all directions away from the rock. Each anchor can support >160 N tangent, >150 N at 45?, and >180 N normal to the surface of the rock. A two-actuator selectively- compliant ankle interfaces these anchors to the Lemur IIB robot for climbing trials. A rotary percussive drill was also integrated into the anchor, demonstrating self-contained rock coring regardless of gravitational orientation. As a harder- than-zero-g proof of concept, 20mm diameter boreholes were drilled 83 mm deep in vesicular basalt samples, retaining a 12 mm diameter rock core in 3-6 pieces while in an inverted configuration, literally drilling into the ceiling.

Inert gas thrusters

NASA Technical Reports Server (NTRS)

Kaufman, H. R.

1976-01-01

Inert gases are of interest as possible alternatives to the usual electric thruster propellants of mercury and cesium. The multipole discharge chamber investigated was shown capable of low discharge chamber losses and flat ion beam profiles with a minimum of optimization. Minimum discharge losses were 200 to 250 eV/ion for xenon and 300 to 350 eV/ion for argon, while flatness parameters in the plane of the accelerator grid were 0.85 to 0.95. The design used employs low magnetic field strengths, which permits the use of sheet-metal parts. The corner problem of the discharge chamber was resolved with recessed corner anodes, which approximately equalized both the magnetic field above the anodes and the electron currents to these anodes. Argon hollow cathodes were investigated at currents up to about 5 amperes using internal thermionic emitters. Cathode chamber diameter optimized in the 1.0 to 2.5 cm range, while orifices diameter optimized in the 0.5 to 5 mm range. The use of a bias voltage for the internal emitter extended the operating range and facilitated starting. The masses of 15 and 30 cm flight type thrusters were estimated at about 4.2 and 10.8 kg.

Graft Diameter as a Predictor for Revision Anterior Cruciate Ligament Reconstruction and KOOS and EQ-5D Values: A Cohort Study From the Swedish National Knee Ligament Register Based on 2240 Patients.

PubMed

Snaebjörnsson, Thorkell; Hamrin Senorski, Eric; Ayeni, Olufemi R; Alentorn-Geli, Eduard; Krupic, Ferid; Norberg, Fredrik; Karlsson, Jón; Samuelsson, Kristian

2017-07-01

Anterior cruciate ligament (ACL) reconstruction (ACLR) using a hamstring tendon (HT) autograft is an effective and widespread method. Recent studies have identified a relationship between the graft diameter and revision ACLR. To evaluate the influence of the graft diameter on revision ACLR and patient-reported outcomes in patients undergoing primary ACLR using HT autografts. Cohort study; Level of evidence, 2. A prospective cohort study was conducted using the Swedish National Knee Ligament Register (SNKLR) involving all patients undergoing primary ACLR using HT autografts. Patients with graft failure who needed revision surgery (cases) were compared with patients not undergoing revision surgery (controls). The control group was matched for sex, age, and graft fixation method in a 3:1 ratio. Conditional logistic regression was performed to produce odds ratios and 95% CIs. Univariate linear regression analyses were performed for patient-related outcomes. The Knee injury and Osteoarthritis Outcome Score (KOOS) and EuroQol 5 dimensions questionnaire (EQ-5D) values were obtained. A total of 2240 patients were included in which there were 560 cases and 1680 controls. No significant differences between the cases and controls were found for sex (52.9% male), mean age (21.7 years), and femoral and tibial fixation. The mean graft diameter for the cases was 8.0 ± 0.74 mm and for the controls was 8.1 ± 0.76 mm. In the present cohort, the likelihood of revision surgery for every 0.5-mm increase in the HT autograft diameter between 7.0 and 10.0 mm was 0.86 (95% CI, 0.75-0.99; P = .03). Univariate linear regression analysis found no significant regression coefficient for the change in KOOS or EQ-5D values. In a large cohort of patients after primary ACLR with HT autografts, an increase in the graft diameter between 7.0 and 10.0 mm resulted in a 0.86 times lower likelihood of revision surgery with every 0.5-mm increase. This study provides further evidence of the importance of the HT autograft size in intraoperative decision making.

Gender, smoking, body size, and aneurysm geometry influence the biomechanical rupture risk of abdominal aortic aneurysms as estimated by finite element analysis.

PubMed

Lindquist Liljeqvist, Moritz; Hultgren, Rebecka; Siika, Antti; Gasser, T Christian; Roy, Joy

2017-04-01

Finite element analysis (FEA) has been suggested to be superior to maximal diameter measurements in predicting rupture of abdominal aortic aneurysms (AAAs). Our objective was to investigate to what extent previously described rupture risk factors were associated with FEA-estimated rupture risk. One hundred forty-six patients with an asymptomatic AAA of a 40- to 60-mm diameter were retrospectively identified and consecutively included. The patients' computed tomography angiograms were analyzed by FEA without (neutral) and with (specific) input of patient-specific mean arterial pressure (MAP), gender, family history, and age. The maximal wall stress/wall strength ratio was described as a rupture risk equivalent diameter (RRED), which translated this ratio into an average aneurysm diameter of corresponding rupture risk. In multivariate linear regression, RRED neutral increased with female gender (3.7 mm; 95% confidence interval [CI], 0.13-7.3) and correlated with patient height (0.27 mm/cm; 95% CI, 0.11-0.43) and body surface area (BSA, 16 mm/m 2 ; 95% CI, 8.3-24) and inversely with body mass index (BMI, -0.40 mm/kg m -2 ; 95% CI, -0.75 to -0.054) in a wall stress-dependent manner. Wall stress-adjusted RRED neutral was raised if the patient was currently smoking (1.1 mm; 95% CI, 0.21-1.9). Age, MAP, family history, and patient weight were unrelated to RRED neutral . In specific FEA, RRED specific increased with female gender, MAP, family history positive for AAA, height, and BSA, whereas it was inversely related to BMI. All results were independent of aneurysm diameter. Peak wall stress and RRED correlated with aneurysm diameter and lumen volume. Female gender, current smoking, increased patient height and BSA, and low BMI were found to increase the mechanical rupture risk of AAAs. Previously described rupture risk factors may in part be explained by patient characteristic-dependent variations in aneurysm biomechanics. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

SU-E-J-215: Towards MR-Only Image Guided Identification of Calcifications and Brachytherapy Seeds: Application to Prostate and Breast LDR Implant Dosimetry

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

Elzibak, A; Fatemi-Ardekani, A; Soliman, A

Purpose: To identify and analyze the appearance of calcifications and brachytherapy seeds on magnitude and phase MRI images and to investigate whether they can be distinguished from each other on corrected phase images for application to prostate and breast low dose rate (LDR) implant dosimetry. Methods: An agar-based gel phantom containing two LDR brachytherapy seeds (Advantage Pd-103, IsoAid, 0.8mm diameter, 4.5mm length) and two spherical calcifications (large: 7mm diameter and small: 4mm diameter) was constructed and imaged on a 3T Philips MR scanner using a 16-channel head coil and a susceptibility weighted imaging (SWI) sequence (2mm slices, 320mm FOV, TR/more » TE= 26.5/5.3ms, 15 degree flip angle). The phase images were unwrapped and corrected using a 32×32, 2D Hanning high pass filter to remove background phase noise. Appearance of the seeds and calcifications was assessed visually and quantitatively using Osirix (http://www.osirix-viewer.com/). Results: As expected, calcifications and brachytherapy seeds appeared dark (hypointense) relative to the surrounding gel on the magnitude MRI images. The diameter of each seed without the surrounding artifact was measured to be 0.1 cm on the magnitude image, while diameters of 0.79 and 0.37 cm were measured for the larger and smaller calcifications, respectively. On the corrected phase images, the brachytherapy seeds and the calcifications appeared bright (hyperintense). The diameter of the seeds was larger on the phase images (0.17 cm) likely due to the dipole effect. Conclusion: MRI has the best soft tissue contrast for accurate organ delineation leading to most accurate implant dosimetry. This work demonstrated that phase images can potentially be useful in identifying brachytherapy seeds and calcifications in the prostate and breast due to their bright appearance, which helps in their visualization and quantification for accurate dosimetry using MR-only. Future work includes optimizing phase filters to best identify and delineate seeds and calcifications.« less

Characterization of a 3D optrode array for infrared neural stimulation

PubMed Central

Abaya, T.V.F.; Diwekar, M.; Blair, S.; Tathireddy, P.; Rieth, L.; Clark, G.A.; Solzbacher, F.

2012-01-01

This paper characterizes the Utah Slant Optrode Array (USOA) as a means to deliver infrared light deep into tissue. An undoped crystalline silicon (100) substrate was used to fabricate 10 × 10 arrays of optrodes with rows of varying lengths from 0.5 mm to 1.5 mm on a 400-μm pitch. Light delivery from optical fibers and loss mechanisms through these Si optrodes were characterized, with the primary loss mechanisms being Fresnel reflection, coupling, radiation losses from the tapered shank and total internal reflection in the tips. Transmission at the optrode tips with different optical fiber core diameters and light in-coupling interfaces was investigated. At λ = 1.55μm, the highest optrode transmittance of 34.7%, relative to the optical fiber output power, was obtained with a 50-μm multi-mode fiber butt-coupled to the optrode through an intervening medium of index n = 1.66. Maximum power is directed into the optrodes when using fibers with core diameters of 200 μm or less. In addition, the output power varied with the optrode length/taper such that longer and less tapered optrodes exhibited higher light transmission efficiency. Output beam profiles and potential impacts on physiological tests were also examined. Future work is expected to improve USOA efficiency to greater than 64%. PMID:23024914

Characterization of a 3D optrode array for infrared neural stimulation.

PubMed

Abaya, T V F; Diwekar, M; Blair, S; Tathireddy, P; Rieth, L; Clark, G A; Solzbacher, F

2012-09-01

This paper characterizes the Utah Slant Optrode Array (USOA) as a means to deliver infrared light deep into tissue. An undoped crystalline silicon (100) substrate was used to fabricate 10 × 10 arrays of optrodes with rows of varying lengths from 0.5 mm to 1.5 mm on a 400-μm pitch. Light delivery from optical fibers and loss mechanisms through these Si optrodes were characterized, with the primary loss mechanisms being Fresnel reflection, coupling, radiation losses from the tapered shank and total internal reflection in the tips. Transmission at the optrode tips with different optical fiber core diameters and light in-coupling interfaces was investigated. At λ = 1.55μm, the highest optrode transmittance of 34.7%, relative to the optical fiber output power, was obtained with a 50-μm multi-mode fiber butt-coupled to the optrode through an intervening medium of index n = 1.66. Maximum power is directed into the optrodes when using fibers with core diameters of 200 μm or less. In addition, the output power varied with the optrode length/taper such that longer and less tapered optrodes exhibited higher light transmission efficiency. Output beam profiles and potential impacts on physiological tests were also examined. Future work is expected to improve USOA efficiency to greater than 64%.

Parametric study of shock-induced combustion in a hydrogen air system

NASA Technical Reports Server (NTRS)

Ahuja, J. K.; Tiwari, Surendra N.

1994-01-01

A numerical parametric study is conducted to simulate shock-induced combustion under various free-stream conditions and varying blunt body diameter. A steady combustion front is established if the free-stream Mach number is above the Chapman-Jouguet speed of the mixture, whereas an unsteady reaction front is established if the free-stream Mach number is below or at the Chapman-Jouguet speed of the mixture. The above two cases have been simulated for Mach 5.11 and Mach 6.46 with a projectile diameter of 15 mm. Mach 5.11, which is an underdriven case, shows an unsteady reaction front, whereas Mach 6.46, which is an overdriven case, shows a steady reaction front. Next for Mach 5. 11 reducing the diameter to 2.5 mm causes the instabilities to disappear, whereas, for Mach 6.46 increasing the diameter of the projectile to 225 mm causes the instabilities to reappear, indicating that Chapman-Jouguet speed is not the only deciding factor for these instabilities to trigger. The other key parameters are the projectile diameter, induction time, activation energy and the heat release. The appearance and disappearance of the instabilities have been explained by the one-dimensional wave interaction model.

Influence of rainfall microstructure on rainfall interception

NASA Astrophysics Data System (ADS)

Zabret, Katarina; Rakovec, Jože; Mikoš, Matjaž; Šraj, Mojca

2016-04-01

Rainfall interception is part of the hydrological cycle. Precipitation, which hits vegetation, is retained on the leaves and branches, from which it eventually evaporates into the atmosphere (interception) or reaches the ground by dripping from the canopy, falling through the gaps (throughfall) and running down the stems (stemflow). The process is influenced by various meteorological and vegetation parameters. Often neglected meteorological parameter influencing rainfall interception is also rainfall microstructure. Rain is a discrete process consisting of various numbers of individual raindrops with different sizes and velocities. This properties describe rainfall microstructure which is often neglected in hydrological analysis and replaced with rainfall intensity. Throughfall, stemflow and rainfall microstructure have been measured since the beginning of the year 2014 under two tree species (Betula pendula and Pinus nigra) on a study plot in Ljubljana, Slovenia. The preliminary analysis of the influence of rainfall microstructure on rainfall interception has been conducted using three events with different characteristics measured in May 2014. Event A is quite short with low rainfall amount and moderate rainfall intensity, whereas events B and C have similar length but low and high intensities, respectively. Event A was observed on the 1st of May 2014. It was 22 minutes long and delivered 1.2 mm of rainfall. The average rainfall intensity was equal to 3.27 mm/h. The event consisted of 1,350 rain drops with average diameter of 1.517 mm and average velocity of 5.110 m/s. Both Betula pendula and Pinus nigra intercepted similar amount of rainfall, 68 % and 69 %, respectively. Event B was observed in the night from the 7th to 8th of May 2014, it was 16 hours and 18 minutes long, and delivered 4.2 mm of rainfall with average intensity of 0.97 mm/h. There were 39,108 raindrops detected with average diameter of 0.858 mm and average velocity of 3.855 m/s. Betula pendula (23 %) has intercepted significantly less rainfall than Pinus nigra (85%). Event C was also observed in the night time between 11th and 12th of May 2014, it lasted 4 hours and 12 minutes and delivered 34.6 mm of rainfall with an average intensity equal to 8.24 mm/h. During the event 147,236 raindrops with average diameter of 1.020 mm and average velocity of 4.078 m/s were detected. Betula pendula has intercepted only 6 % of rainfall whereas Pinus nigra intercepted majority of rainfall, namely 85 %. In case of B. pendula rainfall interception is increasing with higher velocity whereas it is lower for medium diameters than for smaller or larger diameters. Rainfall interception under P. nigra is decreasing with higher velocities and behaving similar as under B. pendula for different diameters but with less obvious difference between diameter classes. We will continue with the measurements and further analysis of several rainfall events will be prepared.

Physical and mechanical characterization of PLLA interference screws produced by two stage injection molding method.

PubMed

Sadeghi-Avalshahr, Ali Reza; Khorsand-Ghayeni, Mohammad; Nokhasteh, Samira; Molavi, Amir Mahdi; Sadeghi-Avalshahr, Mohammad

2016-12-01

The purpose of this study was to produce and evaluate different mechanical, physical and in vitro cell culture characteristics of poly(L-lactic) acid (PLLA) interference screws. This work will focus on evaluating the effect of two important parameters on operation of these screws, first the tunnel diameter which is one of the most important parameters during the operation and second the thermal behavior, the main effective characteristic in production process. In this work, PLLA screws were produced by a two-stage injection molding machine. For mechanical assessment of the produced screws, Polyurethane rigid foam was used as cancellous bone and polypropylene rope as synthetic graft to simulate bone and ligament in real situation. Different tunnel diameters including 7-10 mm were evaluated for fixation strength. When the tunnel diameter was changed from 10 to 9 mm, the pull-out force has increased to about 12 %, which is probably due to the aforementioned frictional forces, however, by reducing the tunnel diameter to 8 and 7 mm, the pull-out force reduced to 16 and 50 % for 8 and 7 mm tunnel diameter, respectively. The minimum and maximum pull-out force was obtained 160.57 and 506.86 N for 7 and 9 mm tunnel diameters, respectively. For physicochemical assay, Fourier transform infrared spectroscopy (FTIR), degradation test and differential scanning calorimetry (DSC) were carried out. The crystallinity (Xc) of samples were decreased considerably from 64.3 % before injection to 32.95 % after injection with two different crystallographic forms α' and α. probably due to the fast cooling rate at room temperature. In addition, MTT and cell attachment assays were utilized by MG63 osteoblast cell line, to evaluate the cytotoxicity of the produced screws. The results revealed no cytotoxicity effect.

Anisocoria

MedlinePlus

... the diameter difference is less than 0.5 mm, but it can be up to 1 mm (0.05 inch). Babies born with different sized ... about. Unequal pupil sizes of more than 1 mm that develop later in life and do NOT ...

Association of Severity of Coronary Artery Aneurysms in Patients With Kawasaki Disease and Risk of Later Coronary Events.

PubMed

Miura, Masaru; Kobayashi, Tohru; Kaneko, Tetsuji; Ayusawa, Mamoru; Fukazawa, Ryuji; Fukushima, Naoya; Fuse, Shigeto; Hamaoka, Kenji; Hirono, Keiichi; Kato, Taichi; Mitani, Yoshihide; Sato, Seiichi; Shimoyama, Shinya; Shiono, Junko; Suda, Kenji; Suzuki, Hiroshi; Maeda, Jun; Waki, Kenji; Kato, Hitoshi; Saji, Tsutomu; Yamagishi, Hiroyuki; Ozeki, Aya; Tomotsune, Masako; Yoshida, Makiko; Akazawa, Yohei; Aso, Kentaro; Doi, Shouzaburoh; Fukasawa, Yoshi; Furuno, Kenji; Hayabuchi, Yasunobu; Hayashi, Miyuki; Honda, Takafumi; Horita, Norihisa; Ikeda, Kazuyuki; Ishii, Masahiro; Iwashima, Satoru; Kamada, Masahiro; Kaneko, Masahide; Katyama, Hiroshi; Kawamura, Yoichi; Kitagawa, Atushi; Komori, Akiko; Kuraishi, Kenji; Masuda, Hiroshi; Matsuda, Shinichi; Matsuzaki, Satoshi; Mii, Sayaka; Miyamoto, Tomoyuki; Moritou, Yuji; Motoki, Noriko; Nagumo, Kiyoshi; Nakamura, Tsuneyuki; Nishihara, Eiki; Nomura, Yuichi; Ogata, Shohei; Ohashi, Hiroyuki; Okumura, Kenichi; Omori, Daisuke; Sano, Tetsuya; Suganuma, Eisuke; Takahashi, Tsutomu; Takatsuki, Shinichi; Takeda, Atsuhito; Terai, Masaru; Toyono, Manatomo; Watanabe, Kenichi; Watanabe, Makoto; Yamamoto, Masaki; Yamamura, Kenichiro

2018-05-07

Few studies with sufficient statistical power have shown the association of the z score of the coronary arterial internal diameter with coronary events (CE) in patients with Kawasaki disease (KD) with coronary artery aneurysms (CAA). To clarify the association of the z score with time-dependent CE occurrence in patients with KD with CAA. This multicenter, collaborative retrospective cohort study of 44 participating institutions included 1006 patients with KD younger than 19 years who received a coronary angiography between 1992 and 2011. The time-dependent occurrence of CE, including thrombosis, stenosis, obstruction, acute ischemic events, and coronary interventions, was analyzed for small (z score, <5), medium (z score, ≥5 to <10; actual internal diameter, <8 mm), and large (z score, ≥10 or ≥8 mm) CAA by the Kaplan-Meier method. The Cox proportional hazard regression model was used to identify risk factors for CE after adjusting for age, sex, size, morphology, number of CAA, resistance to initial intravenous immunoglobulin (IVIG) therapy, and antithrombotic medications. Of 1006 patients, 714 (71%) were male, 341 (34%) received a diagnosis before age 1 year, 501 (50%) received a diagnosis between age 1 and 5 years, and 157 (16%) received a diagnosis at age 5 years or older. The 10-year event-free survival rate for CE was 100%, 94%, and 52% in men (P < .001) and 100%, 100%, and 75% in women (P < .001) for small, medium, and large CAA, respectively. The CE-free rate was 100%, 96%, and 79% in patients who were not resistant to IVIG therapy (P < .001) and 100%, 96%, and 51% in patients who were resistant to IVIG therapy (P < .001), respectively. Cox regression analysis revealed that large CAA (hazard ratio, 8.9; 95% CI, 5.1-15.4), male sex (hazard ratio, 2.8; 95% CI, 1.7-4.8), and resistance to IVIG therapy (hazard ratio, 2.2; 95% CI, 1.4-3.6) were significantly associated with CE. Classification using the internal diameter z score is useful for assessing the severity of CAA in relation to the time-dependent occurrence of CE and associated factors in patients with KD. Careful management of CE is necessary for all patients with KD with CAA, especially men and IVIG-resistant patients with a large CAA.

Cumulative Damage in Strength-Dominated Collisions of Rocky Asteroids: Rubble Piles and Brick Piles

NASA Technical Reports Server (NTRS)

Housen, Kevin

2009-01-01

Laboratory impact experiments were performed to investigate the conditions that produce large-scale damage in rock targets. Aluminum cylinders (6.3 mm diameter) impacted basalt cylinders (69 mm diameter) at speeds ranging from 0.7 to 2.0 km/s. Diagnostics included measurements of the largest fragment mass, velocities of the largest remnant and large fragments ejected from the periphery of the target, and X-ray computed tomography imaging to inspect some of the impacted targets for internal damage. Significant damage to the target occurred when the kinetic energy per unit target mass exceeded roughly 1/4 of the energy required for catastrophic shattering (where the target is reduced to one-half its original mass). Scaling laws based on a rate-dependent strength were developed that provide a basis for extrapolating the results to larger strength-dominated collisions. The threshold specific energy for widespread damage was found to scale with event size in the same manner as that for catastrophic shattering. Therefore, the factor of four difference between the two thresholds observed in the lab also applies to larger collisions. The scaling laws showed that for a sequence of collisions that are similar in that they produce the same ratio of largest fragment mass to original target mass, the fragment velocities decrease with increasing event size. As a result, rocky asteroids a couple hundred meters in diameter should retain their large ejecta fragments in a jumbled rubble-pile state. For somewhat larger bodies, the ejection velocities are sufficiently low that large fragments are essentially retained in place, possibly forming ordered "brick-pile" structures.

Primary Water Stress Corrosion Cracks in Nickel Alloy Dissimilar Metal Welds: Detection and Sizing Using Established and Emerging Nondestructive Examination Techniques

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

Braatz, Brett G.; Cumblidge, Stephen E.; Doctor, Steven R.

2012-12-31

The U.S. Nuclear Regulatory Commission has established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) as a follow-on to the international cooperative Program for the Inspection of Nickel Alloy Components (PINC). The goal of PINC was to evaluate the capabilities of various nondestructive evaluation (NDE) techniques to detect and characterize surface-breaking primary water stress corrosion cracks in dissimilar-metal welds (DMW) in bottom-mounted instrumentation (BMI) penetrations and small-bore (≈400-mm diameter) piping components. A series of international blind round-robin tests were conducted by commercial and university inspection teams. Results from these tests showed that a combination of conventional andmore » phased-array ultrasound techniques provided the highest performance for flaw detection and depth sizing in dissimilar metal piping welds. The effective detection of flaws in BMIs by eddy current and ultrasound shows that it may be possible to reliably inspect these components in the field. The goal of PARENT is to continue the work begun in PINC and apply the lessons learned to a series of open and blind international round-robin tests that will be conducted on a new set of piping components including large-bore (≈900-mm diameter) DMWs, small-bore DMWs, and BMIs. Open round-robin testing will engage universities and industry worldwide to investigate the reliability of emerging NDE techniques to detect and accurately size flaws having a wide range of lengths, depths, orientations, and locations. Blind round-robin testing will invite testing organizations worldwide, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from easy to very difficult to detect and size. This paper presents highlights of PINC and reports on the plans and progress for PARENT round-robin tests.« less

Reliability testing of ultra-low noise InGaAs quad photoreceivers

NASA Astrophysics Data System (ADS)

Joshi, Abhay M.; Datta, Shubhashish; Prasad, Narasimha; Sivertz, Michael

2018-02-01

We have developed ultra-low noise quadrant InGaAs photoreceivers for multiple applications ranging from Laser Interferometric Gravitional Wave Detection, to 3D Wind Profiling. Devices with diameters of 0.5 mm, 1mm, and 2 mm were processed, with the nominal capacitance of a single quadrant of a 1 mm quad photodiode being 2.5 pF. The 1 mm diameter InGaAs quad photoreceivers, using a low-noise, bipolar-input OpAmp circuitry exhibit an equivalent input noise per quadrant of <1.7 pA/√Hz in 2 to 20 MHz frequency range. The InGaAs Quad Photoreceivers have undergone the following reliability tests: 30 MeV Proton Radiation up to a Total Ionizing Dose (TID) of 50 krad, Mechanical Shock, and Sinusoidal Vibration.

Clinical outcome of narrow-diameter (3.3-mm) locking-taper implants: a prospective study with 1 to 10 years of follow-up.

PubMed

Mangano, Francesco; Shibli, Jamil A; Sammons, Rachel L; Veronesi, Giovanni; Piattelli, Adriano; Mangano, Carlo

2014-01-01

To evaluate the outcome of narrow-diameter (3.3-mm) locking-taper implants used in the rehabilitation of partially and fully edentulous patients over a 10-year period. Between January 2002 and December 2011, all patients referred to a private dental clinic for treatment with narrow-diameter implants were enrolled in this study. At each annual follow-up session, clinical and radiographic parameters were assessed; the outcome measurements were implant failure, peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact [DIB]), and biologic and technical complications. The cumulative survival rate (CSR) was assessed using the Kaplan-Meier survival estimator; Tarone-Ware and chi-square analyses were used to evaluate correlations between the study variables. The statistical analysis was performed at the patient- and implant-level. A total of 324 narrow-diameter implants were placed in 279 patients (159 men, 120 women; age: 25 to 73 years). Four implants failed, for an overall CSR of 98.5% (patient-based) and 98.7% (implant-based) at the 10-year follow-up. The survival rate did not differ significantly with respect to patients' sex, age, smoking or parafunctional habits, bone type, prosthetic restoration, or implant location, position, or length. Among the surviving implants, a mean DIB of 0.31 ± 0.23 mm, 0.45 ± 0.27 mm, and 0.69 ± 0.28 mm was observed at the 1-, 5-, and 10-year follow-up examinations, respectively. A few biologic (1.2%) and technical complications (7.5%) were reported. Within the limitations of this study, it can be concluded that narrow-diameter locking-taper implants represent a good treatment option for the prosthetic rehabilitation of partially and totally edentulous patients.

Initial stability of cementless acetabular cups: press-fit and screw fixation interaction--an in vitro biomechanical study.

PubMed

Tabata, Tomonori; Kaku, Nobuhiro; Hara, Katsutoshi; Tsumura, Hiroshi

2015-04-01

Press-fit and screw fixation are important technical factors to achieve initial stability of a cementless acetabular cup for good clinical results of total hip arthroplasty. However, how these factors affect one another in initial cup fixation remains unclear. Therefore, this study aimed to evaluate the mutual influence between press-fit and screw fixation on initial cup stability. Foam bone was subjected to exact hemispherical-shape machining to diameters of 48, 48.5 and 49 mm. A compressive force was applied to ensure seating of a 48-mm-diameter acetabular cup in the foam bone prior to testing. Screws were inserted in six different conditions and tightened in a radial direction at the same torque strength. Then, the socket was rotated with a twist-testing machine, and the torque value at the start of axial rotation between the socket and the foam bone was measured under each screw condition. The torque values for the 48-mm-diameter reaming were >20 N m higher than those for the 48.5- and 49-mm-diameter reaming in each screw condition, indicating that press-fit fixation is stronger than screw fixation. Meanwhile, torque values for the 48.5- and 49-mm-diameter reaming tended to increase with increasing the number of screws. According to our experiment, press-fit fixation of a cementless acetabular cup achieved rigid stability. Although the supplemental screws increased stability of the implant under good press-fit conditions, they showed little impact on whole-cup stability. In the case of insufficient press-fit fixation, cup stability depends on screw stability and increasing the number of additional screws increases cup stability.

Influence of Apical Diameter on the Outcome of Regenerative Endodontic Treatment in Teeth with Pulp Necrosis: A Review.

PubMed

Fang, Yanjun; Wang, Xinhuan; Zhu, Jingjing; Su, Chaonan; Yang, Ying; Meng, Liuyan

2018-03-01

The aim of this review was to evaluate whether the apical diameter of teeth with necrotic pulp affects the outcomes of regenerative endodontic treatment and to determine the minimal apical size needed to obtain proper pulp revascularization. A literature search was performed from January 1, 2001, to November 25, 2016. Studies that satisfied the inclusion criteria were subjected to data extraction and analysis. In total, 14 studies with 85 patients were included. There were 10 case reports, 3 case series, and 1 prospective cohort study. The apical diameters of the teeth were divided into 3 groups: a narrow-sized group (group N), <0.5 mm (n = 10); a medium-sized group (group M), 0.5-1.0 mm (n = 25); and a wide-sized group (group W), >1.0 mm (n = 60). In group N, 1 tooth failed, 2 teeth completely healed, and 7 teeth incompletely healed. In group M, 2 teeth were excluded, and 1 tooth failed. In group W, 3 teeth were excluded, and 4 teeth failed. The clinical success rates were 90%, 95.65%, and 92.98% in groups N, M, and W, respectively. Within the limitations, the teeth with apical diameters <1.0 mm achieved clinical success after regenerative endodontic treatment. Meanwhile, the teeth with apical diameters of 0.5-1.0 mm attained the highest clinical success rate, which may be related to other potential factors, including patient age, pulp necrosis etiology, preoperative apical radiolucency, procedure details, follow-up period, and sample size. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A new technique for the diagnosis of acute appendicitis: abdominal CT with compression to the right lower quadrant.

PubMed

Kılınçer, Abidin; Akpınar, Erhan; Erbil, Bülent; Ünal, Emre; Karaosmanoğlu, Ali Devrim; Kaynaroğlu, Volkan; Akata, Deniz; Özmen, Mustafa

2017-08-01

To determine the diagnostic accuracy of abdominal CT with compression to the right lower quadrant (RLQ) in adults with acute appendicitis. 168 patients (age range, 18-78 years) were included who underwent contrast-enhanced CT for suspected appendicitis performed either using compression to the RLQ (n = 71) or a standard protocol (n = 97). Outer diameter of the appendix, appendiceal wall thickening, luminal content and associated findings were evaluated in each patient. Kruskal-Wallis, Fisher's and Pearson's chi-squared tests were used for statistical analysis. There was no significant difference in the mean outer diameter (MOD) between compression CT scans (10.6 ± 1.9 mm) and standard protocol (11.2 ± 2.3 mm) in patients with acute appendicitis (P = 1). MOD was significantly lower in the compression group (5.2 ± 0.8 mm) compared to the standard protocol (6.5 ± 1.1 mm) (P < 0.01) in patients without appendicitis. A cut-off value of 6.75 mm for the outer diameter of the appendix was found to be 100% sensitive in the diagnosis of acute appendicitis for both groups. The specificity was higher for compression CT technique (67.7 vs. 94.9%). Normal appendix diameter was significantly smaller in the compression-CT group compared to standard-CT group, increasing diagnostic accuracy of abdominal compression CT. • Normal appendix diameter is significantly smaller in compression CT. • Compression could force contrast material to flow through the appendiceal lumen. • Compression CT may be a CT counterpart of graded compression US.

Canine and Premolar Root Dimensions in Chinese. A Reference for Osteoodontokeratoprosthesis Surgery.

PubMed

Sun, Stella Yue; Yeo, Woon Chee; Tay, Andrew Ban Guan; Tan, Donald Tiang Hwee; Tan, Danny Ben Poon

2018-01-01

Osteoodontokeratoprosthesis (OOKP) surgery is used to restore vision in end-stage corneal disorders, where an autogenous tooth supporting an optical cylinder is implanted through the cornea under a buccal mucosal graft. The ideal tooth for OOKP is a healthy single-rooted permanent tooth with sufficient buccolingual/palatal root diameter to accommodate an optical cylinder. The aim of this study was to determine the buccolingual/palatal diameters of canine and premolar roots in Chinese, for selection of teeth for OOKP surgery. This was an anatomical study on root dimensions of extracted intact teeth. Extracted canine and premolar teeth (excluding maxillary first premolars) were collected and the buccolingual/palatal and mesiodistal diameters of the root at the cervical line and at 2-mm intervals below the cervical line were measured with Vernier calipers. Other measurements included total tooth length, crown buccolingual/palatal diameter, and root length. Mean and minimum buccolingual/palatal root diameters were compiled for each 2-mm interval. A total of 415 extracted teeth (198 male, 217 female) were collected and measured. Recorded dimensions of keratoprostheses in 55 previous OOKP surgeries were used to establish acceptable lamina dimensions to ascertain root size adequacy. Premolars in Chinese female patients were undersized in a small minority. Minimal dimensions of teeth were insufficient if at 6 mm root level, the buccolingual/palatal width was less than 5 mm, or the mesiodistal width was less than 3 mm. This was noted in female mandibular first premolars (5.6%), maxillary second premolars (4.5%), and mandibular second premolars (1.5%). Canines have adequate dimensions for OOKP surgery. However, premolars in Chinese females may be undersized in a small minority. Copyright 2017 Asia-Pacific Academy of Ophthalmology.

Surface coverage with single vs. multiple gaze surface topography to fit scleral lenses.

PubMed

DeNaeyer, Gregory; Sanders, Donald R; Farajian, Timothy S

2017-06-01

To determine surface coverage of measurements using the sMap3D ® corneo-scleral topographer in patients presenting for scleral lens fitting. Twenty-five eyes of 23 scleral lens patients were examined. Up-gaze, straight-gaze, and down-gaze positions of each eye were "stitched" into a single map. The percentage surface coverage between 10mm and 20mm diameter circles from corneal center was compared between the straight-gaze and stitched images. Scleral toricity magnitude was calculated at 100% coverage and at the same diameter after 50% of the data was removed. At a 10mm diameter from corneal center, the straight-gaze and stitched images both had 100% coverage. At the 14, 15, 16, 18 and 20mm diameters, the straight-gaze image only covered 68%, 53%, 39%, 18%, and 6% of the ocular surface diameters while the stitched image covered 98%, 96%, 93%, 75%, and 32% respectively. In the case showing the most scleral coverage at 16mm (straight-gaze), there was only 75% coverage (straight-gaze) compared to 100% (stitched image); the case with the least coverage had 7% (straight gaze) and 92% (stitched image). The 95% limits of agreement between the 50% and 100% coverage scleral toricity was between -1.4D (50% coverage value larger) and 1.2D (100% coverage larger), a 2.6D spread. The absolute difference between 50% to 100% coverage scleral toricity was ≥0.50D in 28% and ≥1.0D in 16% of cases. It appears that a single straight-gaze image would introduce significant measurement inaccuracy in fitting scleral lenses using the sMap3D while a 3-gaze stitched image would not. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Influence of the implant-abutment connection design and diameter on the screw joint stability.

PubMed

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung; Jeong, Chang-Mo

2014-04-01

This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). THE POSTLOAD REMOVAL TORQUE VALUE WAS HIGH IN THE FOLLOWING ORDER WITH REGARD TO MAGNITUDE: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate.

Influence of the implant-abutment connection design and diameter on the screw joint stability

PubMed Central

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung

2014-01-01

PURPOSE This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. MATERIALS AND METHODS Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). RESULTS The postload removal torque value was high in the following order with regard to magnitude: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). CONCLUSION The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate. PMID:24843398

Evaluation of 1.0 mm i.d. column performances on ultra high pressure liquid chromatography instrumentation.

PubMed

Lestremau, François; Wu, Di; Szücs, Roman

2010-07-23

The present study focuses on the evaluation of 1.0 mm i.d. (internal diameter) columns on a commercial Ultra-High Pressure system. These systems have been developed specifically to operate columns with small volumes, typically 2.1 mm i.d., by reducing extra-column volume dispersion. The use of columns with smaller i.d. results in a reduced solvent consumption and required sample volume. The evaluation of the columns was carried out with samples containing neutral and pharmaceutical compounds. In isocratic mode, the extra-column volume produced additional band broadening leading to poor performances compared to equivalent 2.1 mm i.d. columns. By increasing the length of the column, the influence of the extra-column bandspreading could be reduced and 75,000 plates were obtained when four columns were coupled. In gradient mode, the effect of the extra-column contribution on efficiency was limited and about 80% of the performance of the 2.1 mm i.d. columns was obtained. Optimum conditions in gradient mode were further investigated by changing flow rate, gradient time and column length. A different approach of the calculation of peak capacity was also considered for the comparison of the influence of these different parameters. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Analysis of initial fixation strength of press-fit fixation technique in anterior cruciate ligament reconstruction. A comparative study with titanium and bioabsorbable interference screw using porcine lower limb.

PubMed

Lee, Myung Chul; Jo, Hyunchul; Bae, Tae-Soo; Jang, Jin Dae; Seong, Sang Cheol

2003-03-01

We performed a controlled laboratory study to evaluate the initial fixation strength of press-fit technique. Forty porcine lower limbs were used and divided into four groups according to the method of fixation; group 1 (press-fit+1.4 mm), in which the diameter difference between the bone plug and the femoral tunnel was 1.4 mm; group 2 (press-fit+1.4 mm, 30 degrees), in which the diameter difference was the same with group 1, but the tensile loading axis was 30 degrees away from the long axis of the femoral tunnel; group 3 (titanium), in which a titanium interference screw was used for fixation; group 4 (bioabsorbable), in which a bioabsorbable interference screw was used for fixation. The graft in the press-fit group was harvested with a hollow oscillating saw with inner diameter of 9.4 mm to obtain consistent and completely circular shape of the bone plug. The femoral tunnel with diameter of 8 mm was drilled at the original ACL insertion. Following the bone plug insertion into the femoral tunnel and applying a preload of 20 N, the specimen underwent 500 loading cycles between 0 and 2 mm of displacement. Thereafter the specimen was loaded to failure. There was no fixation site failure during the cyclic loading test. Significant differences in the stiffness, linear load, or failure mode among the groups were not found. The average ultimate failure load of group 1 and group 2 were not significantly different from those of group 3 and group 4. The press-fit groups demonstrated sufficient fixation strength for the rehabilitation and interference screw groups. The completely circular shape of the bone plug and increased diameter difference between the bone plug and the femoral tunnel seemed to contribute to the strong fixation.

Efficacy of losartan vs. atenolol for the prevention of aortic dilation in Marfan syndrome: a randomized clinical trial.

PubMed

Forteza, Alberto; Evangelista, Arturo; Sánchez, Violeta; Teixidó-Turà, Gisela; Sanz, Paz; Gutiérrez, Laura; Gracia, Teresa; Centeno, Jorge; Rodríguez-Palomares, José; Rufilanchas, Juan Jose; Cortina, José; Ferreira-González, Ignacio; García-Dorado, David

2016-03-21

To determine the efficacy of losartan vs. atenolol in aortic dilation progression in Marfan syndrome (MFS) patients. A phase IIIb, randomized, parallel, double-blind study was conducted in 140 MFS patients, age range: 5-60 years, with maximum aortic diameter <45 mm who received losartan (n = 70) or atenolol (n = 70). Doses were raised to a maximum of 1.4 mg/kg/day or 100 mg/day. The primary end-point was the change in aortic root and ascending aorta maximum diameter indexed by body surface area on magnetic resonance imaging after 36 months of treatment. No serious drug-related adverse effects were observed. Five patients presented aortic events during a follow-up (one in the losartan and four in the atenolol groups, P = 0.366). After 3 years of follow-up, aortic root diameter increased significantly in both groups: 1.1 mm (95% CI 0.6-1.6) in the losartan and 1.4 mm (95% CI 0.9-1.9) in the atenolol group, with aortic dilatation progression being similar in both groups: absolute difference between losartan and atenolol -0.3 mm (95% CI -1.1 to 0.4, P = 0.382) and indexed by BSA -0.5 mm/m2 (95% CI -1.2 to 0.1, P = 0.092). Similarly, no significant differences were found in indexed ascending aorta diameter changes between the losartan and atenolol groups: -0.3 mm/m2 (95% CI -0.8 to 0.3, P = 0.326). Among patients with MFS, the use of losartan compared with atenolol did not result in significant differences in the progression of aortic root and ascending aorta diameters over 3 years of follow-up. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

A stereotaxic atlas of the forebrain of the bank vole (Clethrionomys glareolus).

PubMed

Vandebroek, I; Bouche, K; D'Herde, K; Caemaert, J; Roels, F; Odberg, F O

1999-04-01

In this article part of the forebrain of the bank vole (Clethrionomys glareolus) is presented in stereotaxic coordinates. The stereotaxic procedure was performed as follows. With the vole's head mounted in a stereotaxic adaptor, internal reference tracks were made with a 0.5-mm diameter microdialysis cannula and India ink, 2 mm in front and 2.6 mm behind the skull landmark bregma. Brains were fixed for 72 h in 4% commercial formaldehyde in sodiumcacodylate buffer containing 1% CaCl2. To determine shrinkage they were weighed before and after fixation. After embedding in paraffin they were sectioned at 25 microm and stained with Nissl. Photomicrographs were taken from the brain of one animal while its frontal (antero-posterior) coordinates of five neural structures were compared with those of 12 other voles. Variability was also checked in lateral and vertical directions at frontal level -1.0 mm (relative to bregma). The results show that the distance between the two skull landmarks bregma and lambda correlates significantly and negatively with the antero-posterior position of each of the brain areas. On the basis of these results an equation is proposed to improve accuracy in locating neural structures that deviate due to biological variability.

Design, Modelling and Teleoperation of a 2 mm Diameter Compliant Instrument for the da Vinci Platform.

PubMed

Francis, P; Eastwood, K W; Bodani, V; Looi, T; Drake, J M

2018-05-07

This work explores the feasibility of creating and accurately controlling an instrument for robotic surgery with a 2 mm diameter and a three degree-of-freedom (DoF) wrist which is compatible with the da Vinci platform. The instrument's wrist is composed of a two DoF bending notched-nitinol tube pattern, for which a kinematic model has been developed. A base mechanism for controlling the wrist is designed for integration with the da Vinci Research Kit. A basic teleoperation task is successfully performed using two of the miniature instruments. The performance and accuracy of the instrument suggest that creating and accurately controlling a 2 mm diameter instrument is feasible and the design and modelling proposed in this work provide a basis for future miniature instrument development.

Improvement in trapped fields by stacking bulk superconductors

NASA Astrophysics Data System (ADS)

Suzuki, A.; Wongsatanawarid, A.; Seki, H.; Murakami, M.

2009-10-01

We studied the effects of stacking several bulk superconductor blocks on the field trapping properties. In order to avoid the detrimental effects of the bottom deteriorated parts, bulk Dy-Ba-Cu-O superconductors 45 mm in diameter and 10 mm in thickness were cut from the top parts of as-grown bulk blocks of 25 mm diameter. We stacked the superconductors and measured the field distribution as a function of the gap. The trapped field measurements were performed by field-cooling the samples inserted in between two permanent magnets with liquid nitrogen. It was found that the trapped field values are almost doubled when the number of stacked bulk superconductors increased from two to three. The present results clearly show that one can expect beneficial effects of increasing the ratio of the height to the diameter even in bulk high temperature superconductors.

Protection of Buried Pipe under Repeated Loading by Geocell Reinforcement

NASA Astrophysics Data System (ADS)

Khalaj, Omid; Joz Darabi, N.; Moghaddas Tafreshi, S. N.; Mašek, Bohuslav

2017-12-01

With increase in cities’ population and development of urbane life, passing buried pipelines near ground’s surface is inevitable in urban areas, roads, subways and highways. This paper presents the results of three-dimensional full scale model tests on high-density polyethylene (HDPE) pipe with diameter of 250 mm in geocell reinforced soil, subjected to repeated loading to simulate the vehicle loads. The effect of geocell’s pocket size (55*55 mm and 110*110 mm) and embedment depth of buried pipe (1.5 and 2 times pipe diameter) in improving the behaviour of buried pipes was investigated. The geocell’s height of 100 mm was used in all tests. The repeated load of 800 kPa was applied on circular loading plate with diameter of 250 mm. The results show that the pipe displacement, soil surface settlement and transferred pressure on the pipe’s crown has been influenced significantly upon the use of geocells. For example, the vertical diametric strain (VDS) and soil surface settlement (SSS), in a way that using a geocell with pocket size of 110*110 mm reduces by 27% and 43%, respectively, compared with the unreinforced one. Meanwhile, by increasing buried depth of pipe from 1.5D to 2D, the use of geocell of 110*110 mm delivers about 50% reduction in SSS and VDS, compared with the unreinforced soil.

PORTS MINIMIZATION WITH MINI-PORT AND LIVER FLEXIBLE RETRACTOR: AN ERGONOMIC AND AESTHETIC ALTERNATIVE FOR SINGLE PORT IN LAPAROSCOPIC GASTRIC BYPASS

PubMed Central

de MOURA-JÚNIOR, Luiz Gonzaga; de CASTRO-FILHO, Heládio Feitosa; MACHADO, Francisco Heine Ferreira; BABADOPULOS, Rodrigo Feitosa; FEIJÓ, Francisca das Chagas; FERNANDES, Silvana Duarte

2014-01-01

Background The laparoscopic access, with its classically known benefits, pushed implementation in other components, better ergonomy and aesthetic aspect. Aim To minimize the number and diameter of traditional portals using miniport and flexible liver retractor on bariatric surgery. Method This prospective study was used in patients with less than 45 kg/m2, with peripheral fat, normal umbilicus implantation, without previous abdominoplasties. Were used one 30o optical device with 5 mm in diameter, four accesses (one mini of 3 mm to the left hand of the surgeon, one of 5 mm to the right hand alternating with optics, one of 12 mm for umbilical for surgical maneuvers as dissection, clipping, in/out of gauze, and one portal of 5 mm for the assistant surgeon), resulting in a total of 25 mm linear incision; additionally, one flexible liver retractor (covered with a nelaton probe to protect the liver parenchyma, anchored in the right diaphragmatic pillar and going out through the surgeon left portal) to visualize the esophagogastric angle. Results In selected patients (48 operations), gastric bypass was performed at a similar time to the procedures with larger diameters (5 or 6 portals and 10 mm optics, with sum of linear incision of 42 mm) including oversuture line on excluded stomach, gastric tube and mesenteric closing. The non sutured portal of 3 mm and the two of 5 mm with subdermal sutures, were hardly visible in the folds of the skin; the one of 12 mm was buried inside the umbilicus or in the abdominoplasty incision. Conclusion Minimizing portals is safe, effective, good ergonomic alternative with satisfactory aesthetic profile without need for specific instruments, new learning curve and limited movement of the instruments, as required by the single port. PMID:25409973

Influence of circular stapler diameter on postoperative stenosis after laparoscopic gastrojejunal anastomosis in morbid obesity.

PubMed

Markar, Sheraz R; Penna, Marta; Venkat-Ramen, Vishal; Karthikesalingam, Alan; Hashemi, Majid

2012-01-01

The aim of the present study was to provide a pooled analysis of individual small trials comparing 21-mm and 25-mm circular stapled laparoscopic gastrojejunal (GJ) anastomosis in morbid obesity surgery. A systematic literature search of MEDLINE, Embase, and Cochrane library databases was performed to identify all relevant studies comparing 21-mm and 25-mm circular stapled laparoscopic GJ anastomosis in morbid obesity surgery. The primary outcomes were GJ stenosis and the interval to GJ stenosis. The secondary outcomes were the estimated weight loss, GJ diameter, and the number of endoscopic dilations. Pooled odds ratios were calculated for categorical outcomes and weighted mean differences for continuous outcomes. Five trials were included, comprising 1217 patients (393 with 21-mm and 824 with 25-mm circular GJ anastomoses). The primary outcome analysis revealed a significantly increased incidence of intraluminal stenosis associated with the 21-mm circular stapler (pooled odds ratio 3.54; P < .0001). The secondary outcome analysis revealed a significantly reduced GJ anastomotic diameter on endoscopy with the 21-mm circular stapler group (weighted mean difference -1.67; P = .002). Statistical analysis revealed no significant difference between the groups for the interval to stenosis, number of endoscopic dilations, and estimated weight loss. The results of the present pooled analysis have demonstrated a significantly increased incidence of symptomatic stenosis associated with the 21-mm circular stapler compared with the 25-mm stapler. This serves as evidence to validate the preferential selection of the 25-mm circular stapler for laparoscopic GJ bypass. Copyright © 2012 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Radiographic inspection of porosity in Ti-6Al-4V laser-welded joints.

PubMed

Nuñez-Pantoja, Juliana Maria Costa; Takahashi, Jessica Mie Ferreira Koyama; Nóbilo, Mauro Antônio de Arruda; Consani, Rafael Leonardo Xediek; Mesquita, Marcelo Ferraz

2011-01-01

Widely used in dentistry, Ti-6Al-4V alloy is difficult to cast and solder, as it frequently exhibits pores inside the structure. This study was conducted to evaluate the effect of joint openings and diameters of laser-welded joints executed in Ti-6Al-4V structures on the presence of pores as checked by radiographic procedures. Sixty dumbbell rods with central diameters of 1.5, 2.0 and 3.5 mm were created from Ti-6Al-4V-wrought bars. Specimens were sectioned and welded using two joint openings (0.0 and 0.6 mm). The combination of variables created six groups (n = 10). Laser welding was executed using 360V/8ms (1.5 and 2.0 mm) and 380V/9ms (3.5 mm), with the focus and frequency set to zero. The joints were finished, polished and submitted to radiographic examination. The radiographs were visually examined for the presence of pores in the joints, qualitatively. The percentage of radiographic presence of pores was calculated without counting pores per joint. Data were analyzed using a chi-square test (α = 0.05). For the 1.5-mm specimens, the incidence of pore presence was significantly higher (p = 0.0001) when using 0.6-mm joint openings (40%) compared to 0.0-mm openings (0%). For the 2.0-mm specimens, there was no significant difference between groups (p = 0.2008). However, for the 3.5-mm specimens, the incidence of pore presence was lower (p = 0.0061) for 0.6-mm openings (50%) compared to 0.0-mm openings (70%). Therefore, laser welding of Ti-6Al-4V structures with thin diameters provides the best condition for the juxtaposition of the parts.

Coronary artery dimensions in normal Indians.

PubMed

Raut, Barendra Kumar; Patil, Vijaysinh Namdeo; Cherian, George

Diameter of coronary artery is an important predictor of outcome after percutaneous coronary interventions and coronary artery bypass graft surgery. There is very limited data available about coronary artery dimensions in an Indian population. To study the normal dimensions of the coronary artery segments in Indians without coronary artery disease by using quantitative coronary angiography and also to compare the dimensions in Indians with Western. 229 patients who have undergone coronary angiography with entirely normal coronary angiogram were included in our study. This study showed the diameter of vessels in males and females when taken together the left main was larger in size followed by proximal LAD, proximal RCA & proximal LCX respectively (4.08±0.44mm, 3.27±0.23mm, 3.20±0.37mm, 2.97±0.37mm).When the vessel diameter was indexed to body surface area there was no statistical difference between male and female (p value>0.05). The computed value of proximal coronary artery diameter unadjusted for individual body surface area, when compared to Caucasians showed that Caucasians have larger coronary artery dimensions than Indians. But when the proximal vessel diameter was indexed to body surface area there was no statistical significant difference between Indians and Caucasians (p value>0.05). We found that coronary artery size when indexed to body surface area is not statistically different in Indian males and females and compared to Caucasians. However with a smaller body habitus Indians have smaller coronary arteries. Copyright © 2017. Published by Elsevier B.V.

Plumbing Fixture for a Microfluidic Cartridge

NASA Technical Reports Server (NTRS)

Francis, Kevin

2007-01-01

A fixture has been devised for making the plumbing connections between a microfluidic device in a replaceable cartridge and an external fluidic system. The fixture includes a 0.25-in. (6.35-mm) thick steel plate, to which the cartridge is fastened by two 10-32 thumb screws. The plate holds one plumbing fitting for the inlet and one for the outlet of the microfluidic device. Each fitting includes a fused-silica tube of 0.006-in. (approx.0.15-mm) inside diameter within a fluorinated ethylene-propylene (FEP) tube of 0.0155-in. (approx.0.39-mm) inside diameter and 0.062- in. (approx.1.57-mm) outside diameter. The FEP tube is press-fit through the steel plate so that its exposed end is flush with the surface of the plate, and the silica tube protrudes 0.03 in. (approx.0.76 mm) from the plate/FEP-tube-end surface. The cartridge includes a glass cover plate that contains 0.06-mm-wide access ports. When the cartridge is fastened to the steel plate, the silica tubes become inserted through the access ports and into the body of the cartridge, while the ends of the FEP tubes become butted against the glass cover plate. An extremely tight seal is thereby made.

Optical coherence tomography with a 2.8-mm beam diameter and sensorless defocus and astigmatism correction

NASA Astrophysics Data System (ADS)

Reddikumar, Maddipatla; Tanabe, Ayano; Hashimoto, Nobuyuki; Cense, Barry

2017-02-01

An optical coherence tomography (OCT) system with a 2.8-mm beam diameter is presented. Sensorless defocus correction can be performed with a Badal optometer and astigmatism correction with a liquid crystal device. OCT B-scans were used in an image-based optimization algorithm for aberration correction. Defocus can be corrected from -4.3 D to +4.3 D and vertical and oblique astigmatism from -2.5 D to +2.5 D. A contrast gain of 6.9 times was measured after aberration correction. In comparison with a 1.3-mm beam diameter OCT system, this concept achieved a 3.7-dB gain in dynamic range on a model retina. Both systems were used to image the retina of a human subject. As the correction of the liquid crystal device can take more than 60 s, the subject's spectacle prescription was adopted instead. This resulted in a 2.5 times smaller speckle size compared with the standard OCT system. The liquid crystal device for astigmatism correction does not need a high-voltage amplifier and can be operated at 5 V. The correction device is small (9 mm×30 mm×38 mm) and can easily be implemented in existing designs for OCT.

MR imaging of the inner ear: comparison of a three-dimensional fast spin-echo sequence with use of a dedicated quadrature-surface coil with a gadolinium-enhanced spoiled gradient-recalled sequence.

PubMed

Naganawa, S; Ito, T; Fukatsu, H; Ishigaki, T; Nakashima, T; Ichinose, N; Kassai, Y; Miyazaki, M

1998-09-01

To prospectively evaluate the sensitivity and specificity of magnetic resonance (MR) imaging in the inner ear with a long echo train, three-dimensional (3D), asymmetric Fourier-transform, fast spin-echo (SE) sequence with use of a dedicated quadrature-surface phased-array coil to detect vestibular schwannoma in the cerebellopontine angle and the internal auditory canal. In 205 patients (410 ears) with ear symptoms, 1.5-T MR imaging was performed with unenhanced 3D asymmetric fast SE and gadolinium-enhanced 3D gradient-recalled (SPGR) sequences with use of a quadrature surface phased-array coil. The 3D asymmetric fast SE images were reviewed by two radiologists, with the gadolinium-enhanced 3D SPGR images used as the standard of reference. Nineteen lesions were detected in the 410 ears (diameter range, 2-30 mm; mean, 10.5 mm +/- 6.4 [standard deviation]; five lesions were smaller than 5 mm). With 3D asymmetric fast SE, sensitivity, specificity, and accuracy, respectively, were 100%, 99.5%, and 99.5% for observer 1 and 100%, 99.7%, and 99.8% for observer 2. The unenhanced 3D asymmetric fast SE sequence with a quadrature-surface phased-array coli allows the reliable detection of vestibular schwannoma in the cerebellopontine angle and internal auditory canal.

Sound absorption enhancement of nonwoven felt by using coupled membrane - sonic crystal inclusion

NASA Astrophysics Data System (ADS)

Fitriani, M. C.; Yahya, I.; Harjana; Ubaidillah; Aditya, F.; Siregar, Y.; Moeliono, M.; Sulaksono, S.

2016-11-01

The experimental results from laboratory test on the sound absorption performance of nonwoven felt with an array thin tubes and sonic crystal inclusions reported in this paper. The nonwoven felt sample was produced by a local company with 15 mm in its thickness and 900 gsm. The 6.4 mm diameter plastic straw was used to construct the thin tubes array while the sonic crystal is arranged in a 4 × 4 lattice crystal formation. It made from a PVC cylinder with 17 mm and 50 mm in diameter and length respectively. All cylinders have two holes positioned on 10 mm and 25 mm from the base. The results show that both treatments, array of thin tube and sonic crystal inclusions are effectively increased the sound absorption coefficient of the nonwoven felt significantly especially in the low frequency range starting from 200Hz.

Symmetric tape round REBCO wire with J e (4.2 K, 15 T) beyond 450 A mm‑2 at 15 mm bend radius: a viable candidate for future compact accelerator magnet applications

NASA Astrophysics Data System (ADS)

Kar, Soumen; Luo, Wenbo; Ben Yahia, Anis; Li, Xiaofen; Majkic, Goran; Selvamanickam, Venkat

2018-04-01

Round REBCO (RE = rare earth) wires of 1.6–1.85 mm diameter have been fabricated using ultrathin REBCO tapes where the superconductor film is positioned near the geometric center. Such symmetric tape round (STAR) wires exhibit excellent tolerance to bend strain with a critical current retention of more than 97% when bent to a radius of 15 mm. A 1.6 mm diameter REBCO STAR wire made with six 2.5 mm wide symmetric tapes reached an engineering current density (J e) of 454 A mm‑2 at 4.2 K in a background field of 15 T at a bend radius of 15 mm. Such superior performance at a small bend radius can enable fabrication of future accelerator magnets, operating at magnetic fields above 20 T.

Size ratio correlates with intracranial aneurysm rupture status: a prospective study.

PubMed

Rahman, Maryam; Smietana, Janel; Hauck, Erik; Hoh, Brian; Hopkins, Nick; Siddiqui, Adnan; Levy, Elad I; Meng, Hui; Mocco, J

2010-05-01

The prediction of intracranial aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation aneurysms (<7 mm) have a 0% risk of subarachnoid hemorrhage in 5 years is difficult to reconcile with other studies that reported a significant portion of ruptured IAs are small. These discrepancies have led to the search for better aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs. We prospectively enrolled 40 consecutive patients presenting to a single institution with either ruptured IA or for first-time evaluation of an incidental IA. Blinded technologists acquired all measurements from 2-dimensional angiographic images. Aneurysm rupture status, location, IA maximum size, and parent vessel diameter were documented. The SR was calculated by dividing the aneurysm size (mm) by the average parent vessel size (mm). A 2-tailed Mann-Whitney test was performed to assess statistical significance between ruptured and unruptured groups. Fisher exact test was used to compare medical comorbidities between the ruptured and unruptured groups. Significant differences between the 2 groups were subsequently tested with logistic regression. SE and probability values are reported. Forty consecutive patients with 24 unruptured and 16 ruptured aneurysms met the inclusion criteria. No significant differences were found in age, gender, smoking status, or medical comorbidities between ruptured and unruptured groups. The average maximum size of the unruptured IAs (6.18 + or - 0.60 mm) was significantly smaller compared with the ruptured IAs (7.91 + or - 0.47 mm; P=0.03), and the unruptured group had significantly smaller SRs (2.57 + or - 0.24 mm) compared with the ruptured group (4.08 + or - 0.54 mm; P<0.01). Logistic regression was used to evaluate the independent predictive value of those variables that achieved significance in univariate analysis (IA maximum size and SR). Using stepwise selection, only SR remained in the final predictive model (OR, 2.12; 95% CI, 1.09 to 4.13). SR, the ratio between aneurysm size and parent artery diameter, can be easily calculated from 2-dimensional angiograms and correlates with IA rupture status on presentation in a blinded analysis. SR should be further studied in a large prospective observational cohort to predict true IA risk of rupture.

A novel strategy to translate the biomechanical rupture risk of abdominal aortic aneurysms to their equivalent diameter risk: method and retrospective validation.

PubMed

Gasser, T C; Nchimi, A; Swedenborg, J; Roy, J; Sakalihasan, N; Böckler, D; Hyhlik-Dürr, A

2014-03-01

To translate the individual abdominal aortic aneurysm (AAA) patient's biomechanical rupture risk profile to risk-equivalent diameters, and to retrospectively test their predictability in ruptured and non-ruptured aneurysms. Biomechanical parameters of ruptured and non-ruptured AAAs were retrospectively evaluated in a multicenter study. General patient data and high resolution computer tomography angiography (CTA) images from 203 non-ruptured and 40 ruptured aneurysmal infrarenal aortas. Three-dimensional AAA geometries were semi-automatically derived from CTA images. Finite element (FE) models were used to predict peak wall stress (PWS) and peak wall rupture index (PWRI) according to the individual anatomy, gender, blood pressure, intra-luminal thrombus (ILT) morphology, and relative aneurysm expansion. Average PWS diameter and PWRI diameter responses were evaluated, which allowed for the PWS equivalent and PWRI equivalent diameters for any individual aneurysm to be defined. PWS increased linearly and PWRI exponentially with respect to maximum AAA diameter. A size-adjusted analysis showed that PWS equivalent and PWRI equivalent diameters were increased by 7.5 mm (p = .013) and 14.0 mm (p < .001) in ruptured cases when compared to non-ruptured controls, respectively. In non-ruptured cases the PWRI equivalent diameters were increased by 13.2 mm (p < .001) in females when compared with males. Biomechanical parameters like PWS and PWRI allow for a highly individualized analysis by integrating factors that influence the risk of AAA rupture like geometry (degree of asymmetry, ILT morphology, etc.) and patient characteristics (gender, family history, blood pressure, etc.). PWRI and the reported annual risk of rupture increase similarly with the diameter. PWRI equivalent diameter expresses the PWRI through the diameter of the average AAA that has the same PWRI, i.e. is at the same biomechanical risk of rupture. Consequently, PWRI equivalent diameter facilitates a straightforward interpretation of biomechanical analysis and connects to diameter-based guidelines for AAA repair indication. PWRI equivalent diameter reflects an additional diagnostic parameter that may provide more accurate clinical data for AAA repair indication. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Eustachian tube diameter: Is it associated with chronic otitis media development?

PubMed

Paltura, Ceki; Can, Tuba Selçuk; Yilmaz, Behice Kaniye; Dinç, Mehmet Emre; Develioğlu, Ömer Necati; Külekçi, Mehmet

To evaluate the effect of ET diameter on Chronic Otitis Media (COM) pathogenesis. Retrospective. Patients with unilateral COM disease are included in the study. The connection between fibrocartilaginous and osseous segments of the Eustachian Tube (ET) on axial Computed Tomography (CT) images was defined and the diameter of this segment is measured. The measurements were carried out bilaterally and statistically compared. 154 (76 (49%) male, 78 (51%) female patients were diagnosed with unilateral COM and included in the study. The mean diameter of ET was 1947mm (Std. deviation±0.5247) for healthy ears and 1788mm (Std. deviation±0.5306) for diseased ears. The statistical analysis showed a significantly narrow ET diameter in diseased ear side (p<0.01). The dysfunction or anatomical anomalies of ET are correlated with COM. Measuring of the bony diameter of ET during routine Temporal CT examination is recommended for our colleagues. Copyright © 2017 Elsevier Inc. All rights reserved.

Carbon dioxide‐mediated vasomotion of extra‐cranial cerebral arteries in humans: a role for prostaglandins?

PubMed Central

Tymko, Michael M.; Bain, Anthony R.; Wildfong, Kevin W.; Monteleone, Brad; Ainslie, Philip N.

2016-01-01

Key points Cerebral blood flow increases during hypercapnia and decreases during hypocapnia; it is unknown if vasomotion of the internal carotid artery is implicated in these responses.Indomethacin, a non‐selective cyclooxygenase inhibitor (used to inhibit prostaglandin synthesis), has a unique ability to blunt cerebrovascular carbon dioxide reactivity, while other cyclooxygenase inhibitors have no effect.We show significant dilatation and constriction of the internal carotid artery during hypercapnia and hypocapnia, respectively.Indomethacin, but not ketorolac or naproxen, reduced the dilatatory response of the internal carotid artery to hypercapniaThe differential effect of indomethacin compared to ketorolac and naproxen suggests that indomethacin inhibits vasomotion of the internal carotid artery independent of prostaglandin synthesis inhibition. Abstract Extra‐cranial cerebral blood vessels are implicated in the regulation of cerebral blood flow during changes in arterial CO2; however, the mechanisms governing CO2‐mediated vasomotion of these vessels in humans remain unclear. We determined if cyclooxygenase inhibition with indomethacin (INDO) reduces the vasomotor response of the internal carotid artery (ICA) to changes in end‐tidal CO2 (P ETC O2). Using a randomized single‐blinded placebo‐controlled study, participants (n = 10) were tested on two occasions, before and 90 min following oral INDO (1.2 mg kg–1) or placebo. Concurrent measurements of beat‐by‐beat velocity, diameter and blood flow of the ICA were made at rest and during steady‐state stages (4 min) of iso‐oxic hypercapnia (+3, +6, +9 mmHg P ETC O2) and hypocapnia (−3, −6, −9 mmHg P ETC O2). To examine if INDO affects ICA vasomotion independent of cyclooxygenase inhibition, two participant subsets (each n = 5) were tested before and following oral ketorolac (post 45 min, 0.25 mg kg–1) or naproxen (post 90 min, 4.2 mg kg–1). During pre‐drug testing in the INDO trial, the ICA dilatated during hypercapnia at +6 mmHg (4.72 ± 0.45 vs. 4.95 ± 0.51 mm; P < 0.001) and +9 mmHg (4.72 ± 0.45 mm vs. 5.12 ± 0.47 mm; P < 0.001), and constricted during hypocapnia at −6 mmHg (4.95 ± 0.33 vs. 4.88 ± 0.27 mm; P < 0.05) and −9 mmHg (4.95 ± 0.33 vs. 4.82 ± 0.27 mm; P < 0.001). Following INDO, vasomotor responsiveness of the ICA to hypercapnia was reduced by 67 ± 28% (0.045 ± 0.015 vs. 0.015 ± 0.012 mm mmHg P ETC O2 −1). There was no effect of the drug in the ketorolac and naproxen trials. We conclude that: (1) INDO markedly reduces the vasomotor response of the ICA to changes in P ETC O2; and (2) INDO may be reducing CO2‐mediated vasomotion via a mechanism(s) independent of cyclooxygenase inhibition. PMID:26880615

Plasma Discharge with Different Electrode Diameters for Reducing Methylene Blue Concentration

NASA Astrophysics Data System (ADS)

Rasyidah, H.; Kusumandari; Saraswati, T. E.; Anwar, M.

2018-03-01

Recently, plasma technology has gained attention since it overcomes the shortcomings of water treatment. This research studies the effect of electrode diameter of plasma discharge reactors on the concentration reduction of methylene blue as an organic solution. The plasma discharge reactor was built from a pair of stainless needle electrodes connected with high-AC voltage. The electrodes were placed approximately 2 mm above the solution and stirred at 5.5 rpm. The diameters of the electrodes were 2, 3.2 and 4 mm. The times for plasma treatment were set at 2, 4, 6, 8 and 10 min. Absorbance, temperature and pH of the solution were measured to know the effects of electrode diameter of the plasma reactor. Absorbance and pH significantly decreased after plasma treatment. The best of the absorbance reduction were obtained when the sample was treated under plasma discharge using the smallest diameter electrodes for 8-10 min.

Sensing and Timekeeping Using A Light Trapping

DTIC Science & Technology

2017-06-01

bioassays, condensed matter physics, mate- rial science, biothermometry, bulk magnetometry for surveying, and hyper -polarized media for NMR. 1.3.2...obtained under continuous-wave (CW) microwave field excitation when a 3 mm diameter loop of 200 µm-diameter wire is placed 5 mm above the LTDW. An...frequency-locking technique was also developed to monitor both resonances simultaneously. A closed- loop system that locks to the center frequency of

Design of a multifiber light delivery system for photoacoustic-guided surgery.

PubMed

Eddins, Blackberrie; Bell, Muyinatu A Lediju

2017-04-01

This work explores light delivery optimization for photoacoustic-guided minimally invasive surgeries, such as the endonasal transsphenoidal approach. Monte Carlo simulations were employed to study three-dimensional light propagation in tissue, comprising one or two 4-mm diameter arteries located 3 mm below bone, an absorbing metallic drill contacting the bone surface, and a single light source placed next to the 2.4-mm diameter drill shaft with a 2.9-mm diameter spherical drill tip. The optimal fiber distance from the drill shaft was determined from the maximum normalized fluence to the underlying artery. Using this optimal fiber-to-drill shaft distance, Zemax simulations were employed to propagate Gaussian beams through one or more 600 micron-core diameter optical fibers for detection on the bone surface. When the number of equally spaced fibers surrounding the drill increased, a single merged optical profile formed with seven or more fibers, determined by thresholding the resulting light profile images at 1 / e times the maximum intensity. We used these simulations to inform design requirements, build a one to seven multifiber light delivery prototype to surround a surgical drill, and demonstrate its ability to simultaneously visualize the tool tip and blood vessel targets in the absence and presence of bone. The results and methodology are generalizable to multiple interventional photoacoustic applications.

Design of a multifiber light delivery system for photoacoustic-guided surgery

NASA Astrophysics Data System (ADS)

Eddins, Blackberrie; Bell, Muyinatu A. Lediju

2017-04-01

This work explores light delivery optimization for photoacoustic-guided minimally invasive surgeries, such as the endonasal transsphenoidal approach. Monte Carlo simulations were employed to study three-dimensional light propagation in tissue, comprising one or two 4-mm diameter arteries located 3 mm below bone, an absorbing metallic drill contacting the bone surface, and a single light source placed next to the 2.4-mm diameter drill shaft with a 2.9-mm diameter spherical drill tip. The optimal fiber distance from the drill shaft was determined from the maximum normalized fluence to the underlying artery. Using this optimal fiber-to-drill shaft distance, Zemax simulations were employed to propagate Gaussian beams through one or more 600 micron-core diameter optical fibers for detection on the bone surface. When the number of equally spaced fibers surrounding the drill increased, a single merged optical profile formed with seven or more fibers, determined by thresholding the resulting light profile images at 1/e times the maximum intensity. We used these simulations to inform design requirements, build a one to seven multifiber light delivery prototype to surround a surgical drill, and demonstrate its ability to simultaneously visualize the tool tip and blood vessel targets in the absence and presence of bone. The results and methodology are generalizable to multiple interventional photoacoustic applications.

Effects of abutment diameter, luting agent type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments.

PubMed

Safari, Sina; Hosseini Ghavam, Fereshteh; Amini, Parviz; Yaghmaei, Kaveh

2018-02-01

The aim of this study was to evaluate the effects of abutment diameter, cement type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments. Sixty abutments with two different diameters, the height of which was reduced to 3 mm, were vertically mounted in acrylic resin blocks with matching implant analogues. The specimens were divided into 2 diameter groups: 4.5 mm and 5.5 mm (n=30). For each abutment a CAD/CAM metal coping was manufactured, with an occlusal loop. Each group was sub-divided into 3 sub-groups (n=10). In each subgroup, a different cement type was used: resin-modified glass-ionomer, resin cement and zinc-oxide-eugenol. After incubation and thermocycling, the removal force was measured using a universal testing machine at a cross-head speed of 0.5 mm/min. In zinc-oxide-eugenol group, after removal of the coping, the cement remnants were completely cleaned and the copings were re-cemented with resin cement and re-tested. Two-way ANOVA, post hoc Tukey tests, and paired t-test were used to analyze data (α=.05). The highest pulling force was registered in the resin cement group (414.8 N), followed by the re-cementation group (380.5 N). Increasing the diameter improved the retention significantly ( P =.006). The difference in retention between the cemented and recemented copings was not statistically significant ( P =.40). Resin cement provided retention almost twice as strong as that of the RMGI. Increasing the abutment diameter improved retention significantly. Re-cementation with resin cement did not exhibit any difference from the initial cementation with resin cement.

Effects of abutment diameter, luting agent type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments

PubMed Central

Safari, Sina; Amini, Parviz; Yaghmaei, Kaveh

2018-01-01

PURPOSE The aim of this study was to evaluate the effects of abutment diameter, cement type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments. MATERIALS AND METHODS Sixty abutments with two different diameters, the height of which was reduced to 3 mm, were vertically mounted in acrylic resin blocks with matching implant analogues. The specimens were divided into 2 diameter groups: 4.5 mm and 5.5 mm (n=30). For each abutment a CAD/CAM metal coping was manufactured, with an occlusal loop. Each group was sub-divided into 3 sub-groups (n=10). In each subgroup, a different cement type was used: resin-modified glass-ionomer, resin cement and zinc-oxide-eugenol. After incubation and thermocycling, the removal force was measured using a universal testing machine at a cross-head speed of 0.5 mm/min. In zinc-oxide-eugenol group, after removal of the coping, the cement remnants were completely cleaned and the copings were re-cemented with resin cement and re-tested. Two-way ANOVA, post hoc Tukey tests, and paired t-test were used to analyze data (α=.05). RESULTS The highest pulling force was registered in the resin cement group (414.8 N), followed by the re-cementation group (380.5 N). Increasing the diameter improved the retention significantly (P=.006). The difference in retention between the cemented and recemented copings was not statistically significant (P=.40). CONCLUSION Resin cement provided retention almost twice as strong as that of the RMGI. Increasing the abutment diameter improved retention significantly. Re-cementation with resin cement did not exhibit any difference from the initial cementation with resin cement. PMID:29503708

Unruptured cerebral aneurysms do not shrink when they rupture: multicenter collaborative aneurysm study group.

PubMed

Rahman, Maryam; Ogilvy, Christopher S; Zipfel, Gregory J; Derdeyn, Colin P; Siddiqui, Adnan H; Bulsara, Ketan R; Kim, Louis J; Riina, Howard A; Mocco, J; Hoh, Brian L

2011-01-01

The International Study of Intracranial Aneurysms found that for patients with no previous history of subarachnoid hemorrhage, small (< 7 mm) anterior circulation and posterior circulation aneurysms had a 0% and 2.5% risk of subarachnoid hemorrhage over 5 years, respectively. To determine whether cerebral aneurysms shrink with rupture. The clinical databases of 7 sites were screened for patients with imaging of cerebral aneurysms before and after rupture. Inclusion criteria included documented subarachnoid hemorrhage by imaging or lumbar puncture and intracranial imaging before and after cerebral aneurysm rupture. The patients were evaluated for aneurysm maximal height, maximal width, neck diameter, and other measurement parameters. Only a change of ≥ 2 mm was considered a true change. Data on 13 patients who met inclusion criteria were collected. The median age was 60, and 11 of the 13 patients (84.6%) were female. Only 5 patients had posterior circulation aneurysms. None of the aneurysms had a significant decrease in size. One aneurysm decreased by 1.8 mm in maximum size after rupture (7.7%). Six aneurysms had an increase in maximum size of at least 2 mm after rupture (46.2%) with a mean increase of 3.5 mm (± 0.5 mm). Unruptured aneurysms do not shrink when they rupture. The large percentage of ruptured small aneurysms in previous studies were likely small before they ruptured.

Comparative Evaluation of the Ostium After External and Nonendoscopic Endonasal Dacryocystorhinostomy Using Image Processing (Matlabs and Image J) Softwares.

PubMed

Ganguly, Anasua; Kaza, Hrishikesh; Kapoor, Aditya; Sheth, Jenil; Ali, Mohammad Hasnat; Tripathy, Devjyoti; Rath, Suryasnata

The purpose of this study was to compare the characteristics of the ostium after external dacryocystorhinostomy and nonendoscopic endonasal dacryocystorhinostomy (NEN-DCR). This cross-sectional study included patients who underwent a successful external dacryocystorhinostomy or NEN-DCR and had ≥1 month follow up. Pictures of the ostium were captured with a nasal endoscope (4 mm, 30°) after inserting a lacrimal probe premarked at 2 mm. Image analyses were performed using Image J and Contour softwares. Of the 113 patients included, external dacryocystorhinostomy group had 53 patients and NEN-DCR group had 60 patients. The mean age of patients in the NEN-DCR group (38 years) was significantly (p < 0.05) lower than the external dacryocystorhinostomy group (50 years). There was no statistically significant difference (2 sample t test, p > 0.05) in mean follow up (6 vs. 4 months), maximum diameter of ostium (8 vs. 7 mm), perpendicular drawn to it (4 vs. 4 mm), area of ostium (43 vs. 36 mm), and the minimum distance between common internal punctum and edge of the ostium (1 vs. 1 mm) between the external and NEN-DCR groups. Image processing softwares offer simple and objective method to measure the ostium. While ostia are comparable in size, their relative position differs with posteriorly placed ostia in external compared with inferior in NEN-DCR.

Vibrational spectra of individual millimeter-size membrane patches using miniature infrared waveguides.

PubMed Central

Plunkett, S E; Jonas, R E; Braiman, M S

1997-01-01

We have used miniature planar IR waveguides, consisting of Ge strips 30-50 microm thick and 2 mm wide, as evanescent-wave sensors to detect the mid-(IR) evanescent-wave absorbance spectra of small areas of biomolecular monolayers and multilayers. Examples include picomolar quantities of an integral transmembrane protein (bacteriorhodopsin) and lipid (dimyristoyl phosphatidylcholine). IR bands due to the protein and lipid components of the plasma membrane of individual 1.5-mm-diameter devitellinized Xenopus laevis oocytes, submerged in buffer and sticking to the waveguide surface, were also detected. A significant improvement in sensitivity was observed, as compared to previous sizes and geometries of evanescent-wave sensors (e.g., commercially available internal reflection elements or tapered optical fibers). These measurements suggest the feasibility of using such miniature supported planar IR waveguides to observe structural changes in transmembrane proteins functioning in vivo in single cells. PMID:9336219

Minimally invasive sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure: a multicenter retrospective study.

PubMed

Kim, Ji-Min; Sohn, Dong-Seok; Heo, Jeong-Uk; Park, Jun-Sub; Jung, Heui-Seung; Moon, Jee-Won; Lee, Ju-Hyoung; Park, In-Sook

2012-12-01

The purpose of this study was to evaluate the success rate of implants and vertical bone gain of edentulous posterior maxilla using ultrasonic piezoelectric vibration and hydraulic pressure, namely the hydrodynamic piezoelectric internal sinus elevation (HPISE) technique through a crestal approach. A total of 250 maxillary sinuses were augmented using HPISE and 353 implants (averaging 11.8 mm in length and 4.5 mm in diameter), with 12 different systems, were placed simultaneously with or without additional bone grafting. Plain radiograms and cone beam computed tomograms were taken in all patients to evaluate sinus augmentation. Membrane perforation was recorded at 10 of the 353 implant sites. The perforation rate was 2.83%. The total success rate of implantation was 97.2% after an average of 69.3 weeks of loading. The crestally approached sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure is an additional method of maxillary sinus augmentation.

High resolution NMR imaging using a high field yokeless permanent magnet.

PubMed

Kose, Katsumi; Haishi, Tomoyuki

2011-01-01

We measured the homogeneity and stability of the magnetic field of a high field (about 1.04 tesla) yokeless permanent magnet with 40-mm gap for high resolution nuclear magnetic resonance (NMR) imaging. Homogeneity was evaluated using a 3-dimensional (3D) lattice phantom and 3D spin-echo imaging sequences. In the central sphere (20-mm diameter), peak-to-peak magnetic field inhomogeneity was about 60 ppm, and the root-mean-square was 8 ppm. We measured room temperature, magnet temperature, and NMR frequency of the magnet simultaneously every minute for about 68 hours with and without the thermal insulator of the magnet. A simple mathematical model described the magnet's thermal property. Based on magnet performance, we performed high resolution (up to [20 µm](2)) imaging with internal NMR lock sequences of several biological samples. Our results demonstrated the usefulness of the high field small yokeless permanent magnet for high resolution NMR imaging.