Pulmonary Lobe Segmentation with Probabilistic Segmentation of the Fissures and a Groupwise Fissure Prior

PubMed Central

Bragman, Felix J.S.; McClelland, Jamie R.; Jacob, Joseph; Hurst, John R.; Hawkes, David J.

2017-01-01

A fully automated, unsupervised lobe segmentation algorithm is presented based on a probabilistic segmentation of the fissures and the simultaneous construction of a population model of the fissures. A two-class probabilistic segmentation segments the lung into candidate fissure voxels and the surrounding parenchyma. This was combined with anatomical information and a groupwise fissure prior to drive non-parametric surface fitting to obtain the final segmentation. The performance of our fissure segmentation was validated on 30 patients from the COPDGene cohort, achieving a high median F1-score of 0.90 and showed general insensitivity to filter parameters. We evaluated our lobe segmentation algorithm on the LOLA11 dataset, which contains 55 cases at varying levels of pathology. We achieved the highest score of 0.884 of the automated algorithms. Our method was further tested quantitatively and qualitatively on 80 patients from the COPDGene study at varying levels of functional impairment. Accurate segmentation of the lobes is shown at various degrees of fissure incompleteness for 96% of all cases. We also show the utility of including a groupwise prior in segmenting the lobes in regions of grossly incomplete fissures. PMID:28436850

Expression profiling during ocular development identifies 2 Nlz genes with a critical role in optic fissure closure.

PubMed

Brown, Jacob D; Dutta, Sunit; Bharti, Kapil; Bonner, Robert F; Munson, Peter J; Dawid, Igor B; Akhtar, Amana L; Onojafe, Ighovie F; Alur, Ramakrishna P; Gross, Jeffrey M; Hejtmancik, J Fielding; Jiao, Xiaodong; Chan, Wai-Yee; Brooks, Brian P

2009-02-03

The gene networks underlying closure of the optic fissure during vertebrate eye development are poorly understood. Here, we profile global gene expression during optic fissure closure using laser capture microdissected (LCM) tissue from the margins of the fissure. From these data, we identify a unique role for the C(2)H(2) zinc finger proteins Nlz1 and Nlz2 in normal fissure closure. Gene knockdown of nlz1 and/or nlz2 in zebrafish leads to a failure of the optic fissure to close, a phenotype which closely resembles that seen in human uveal coloboma. We also identify misregulation of pax2 in the developing eye of morphant fish, suggesting that Nlz1 and Nlz2 act upstream of the Pax2 pathway in directing proper closure of the optic fissure.

Monitoring of the Ground Fissure Activity Within Yuncheng Basin by Time Series Insar

NASA Astrophysics Data System (ADS)

Zhang, F.; Yang, C. S.; Zhao, C. Y.; Liu, R. C.

2018-04-01

Yuncheng area is one of the most extensive distributions of ground fissures in Shanxi basin, especially in Yanhu District of Yuncheng, the disaster of ground fissures and ground subsidence are the most serious. According to previous studies, the development and distribution of the ground fissures in this area are mainly controlled by the underlying active faults. In order to provide a better understanding of the formation mechanism, the deformation of ground fissures and its surrounding environment should be taken into consideration. In this paper, PS-InSAR technology was employed to assess the time-series ground deformation of Yuncheng ground fissures and its surrounding area with X-band TerraSAR images from 2013 to 2015. The interaction between ground fissures activity and land subsidence, groundwater, precipitation and surrounding faults will be discussed.

A Case Series of Anal Carcinoma Misdiagnosed as Idiopathic Chronic Anal Fissure.

PubMed

Barbeiro, Sandra; Atalaia-Martins, Catarina; Marcos, Pedro; Gonçalves, Cláudia; Cotrim, Isabel; Vasconcelos, Helena

2017-09-01

Chronic anal fissure is a linear ulcer in the anal canal that has not cicatrized for more than 8-12 weeks of treatment. Most anal fissures are idiopathic and are located in the posterior midline. Squamous cell carcinoma of the anus commonly presents as bleeding and anal pain. It may also present as a mass, nonhealing ulcer, itching, discharge, fecal incontinence and fistulae. Not uncommonly, small and early cancers are misdiagnosed as benign anorectal disorders like anal fissures or hemorrhoids. The clinical suspicion of squamous cell carcinoma of the anus is of paramount importance in patients with nonhealing anal fissures, fissures in atypical positions or with indurated or ulcerated anal tags and in patients with risk factors for the development of anal squamous intraepithelial lesions that are precursors of invasive anal squamous cell carcinoma. The authors present 3 cases of squamous cell carcinoma of the anus initially misdiagnosed as benign chronic anal fissure.

Selection for fissure resistance now made possible in early breeding generations

USDA-ARS?s Scientific Manuscript database

Rice kernel fissuring is one of the leading causes of milling yield losses. Any reduction in fissuring can result in direct increases in yield and profit for both producers and millers. While most U.S. rice varieties yield around 55% head rice, the fissure-resistant varieties ‘Cypress’, ‘Saber’ an...

Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i

NASA Astrophysics Data System (ADS)

Fee, David; Garces, Milton; Orr, Tim; Poland, Mike

2011-03-01

Varied acoustic signals were recorded at Kīlauea Volcano in mid-2007, coincident with dramatic changes in the volcano's activity. Prior to this time period, Pu'u 'Ō'ō crater produced near-continuous infrasonic tremor and was the primary source of degassing and lava effusion at Kīlauea. Collapse and draining of Pu'u 'Ō'ō crater in mid-June produced impulsive infrasonic signals and fluctuations in infrasonic tremor. Fissure eruptions on 19 June and 21 July were clearly located spatially and temporally using infrasound arrays. The 19 June eruption from a fissure approximately mid-way between Kīlauea's summit and Pu'u 'Ō'ō produced infrasound for ˜30 minutes—the only observed geophysical signal associated with the fissure opening. The infrasound signal from the 21 July eruption just east of Pu'u 'Ō'ō shows a clear azimuthal progression over time, indicative of fissure propagation over 12.9 hours. The total fissure propagation rate is relatively slow at 164 m/hr, although the fissure system ruptured discontinuously. Individual fissure rupture times are estimated using the acoustic data combined with visual observations.

Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i

USGS Publications Warehouse

Fee, D.; Garces, M.; Orr, T.; Poland, M.

2011-01-01

Varied acoustic signals were recorded at Kīlauea Volcano in mid-2007, coincident with dramatic changes in the volcano's activity. Prior to this time period, Pu'u 'Ō'ō crater produced near-continuous infrasonic tremor and was the primary source of degassing and lava effusion at Kīlauea. Collapse and draining of Pu'u 'Ō'ō crater in mid-June produced impulsive infrasonic signals and fluctuations in infrasonic tremor. Fissure eruptions on 19 June and 21 July were clearly located spatially and temporally using infrasound arrays. The 19 June eruption from a fissure approximately mid-way between Kīlauea's summit and Pu'u 'O'o produced infrasound for ~30 minutes-the only observed geophysical signal associated with the fissure opening. The infrasound signal from the 21 July eruption just east of Pu'u 'Ō'ō shows a clear azimuthal progression over time, indicative of fissure propagation over 12.9 hours. The total fissure propagation rate is relatively slow at 164 m/hr, although the fissure system ruptured discontinuously. Individual fissure rupture times are estimated using the acoustic data combined with visual observations.

Silicic central volcanoes as precursors to rift propagation: the Afar case

NASA Astrophysics Data System (ADS)

Lahitte, Pierre; Gillot, Pierre-Yves; Courtillot, Vincent

2003-02-01

The Afar depression is a triple junction characterised by thinned continental crust, where three rift systems meet (Red Sea, Gulf of Aden and East African Rift). About 100 recent K-Ar ages obtained on Plio-Pleistocene lavas [Lahitte et al., J. Geophys. Res. (2002) in press; Kidane et al., J. Geophys. Res. (2002) in press], complemented by new geomorphological interpretations, allow better understanding of the volcano-tectonic activity linked to rift propagation. In Central Afar, a significant spatial and temporal correlation is observed between the occurrence of silicic central volcanoes and the initiation of the successive phases of on-land propagation of the Red Sea and Aden rifts. Inside the Afar depression, at the scale of both a whole ridge and a small rift segment, silicic lavas are systematically erupted close to the location of a future rift segment and prior to the main extensive phase associated with fissural basaltic activity. Central silicic volcanoes therefore appear to be precursor features, and their locations underline the preferred direction of future rift propagation. Evolved volcanoes (and associated magma chambers) form zones of localised lithospheric weakness, which concentrate stress and guide the development of fractures in which fissural magmatism is next emplaced. Differentiated silicic lavas are erupted first. Then, as extension increases, basaltic magma directly erupts to the surface. This composite style of rifting, with volcanic and tectonic components, is a scaled-down equivalent of the continental break-up process at the largest scale.

An Investigation of the Morphology of the Petrotympanic Fissure Using Cone-Beam Computed Tomography

PubMed Central

Syriopoulos, Konstantinos; Sens, Rogier L.; Politis, Constantinus

2018-01-01

ABSTRACT Objectives The purpose of the present study was: a) to examine the visibility and morphology of the petrotympanic fissure on cone-beam computed tomography images, and b) to investigate whether the petrotympanic fissure morphology is significantly affected by gender and age, or not. Material and Methods Using Newtom VGi (QR Verona, Italy), 106 cone-beam computed tomography examinations (212 temporomandibular joint areas) of both genders were retrospectively and randomly selected. Two observers examined the images and subsequently classified by consensus the petrotympanic fissure morphology into the following three types: type 1 - widely open; type 2 - narrow middle; type 3 - very narrow/closed. Results The petrotympanic fissure morphology was assessed as type 1, type 2, and type 3 in 85 (40.1%), 72 (34.0%), and 55 (25.9%) cases, respectively. No significant difference was found between left and right petrotympanic fissure morphology (Kappa = 0.37; P < 0.001). Furthermore, no significant difference was found between genders, specifically P = 0.264 and P = 0.211 for the right and left petrotympanic fissure morphology, respectively. However, the ordinal logistic regression analysis showed that males tend to have narrower petrotympanic fissures, in particular OR = 1.58 for right and OR = 1.5 for left petrotympanic fissure. Conclusions The current study lends support to the conclusion that an enhanced multi-planar cone-beam computed tomography yields a clear depiction of the petrotympanic fissure's morphological characteristics. We have found that the morphology is neither gender nor age-related. PMID:29707183

An Investigation of the Morphology of the Petrotympanic Fissure Using Cone-Beam Computed Tomography.

PubMed

Damaskos, Spyros; Syriopoulos, Konstantinos; Sens, Rogier L; Politis, Constantinus

2018-01-01

The purpose of the present study was: a) to examine the visibility and morphology of the petrotympanic fissure on cone-beam computed tomography images, and b) to investigate whether the petrotympanic fissure morphology is significantly affected by gender and age, or not. Using Newtom VGi (QR Verona, Italy), 106 cone-beam computed tomography examinations (212 temporomandibular joint areas) of both genders were retrospectively and randomly selected. Two observers examined the images and subsequently classified by consensus the petrotympanic fissure morphology into the following three types: type 1 - widely open; type 2 - narrow middle; type 3 - very narrow/closed. The petrotympanic fissure morphology was assessed as type 1, type 2, and type 3 in 85 (40.1%), 72 (34.0%), and 55 (25.9%) cases, respectively. No significant difference was found between left and right petrotympanic fissure morphology (Kappa = 0.37; P < 0.001). Furthermore, no significant difference was found between genders, specifically P = 0.264 and P = 0.211 for the right and left petrotympanic fissure morphology, respectively. However, the ordinal logistic regression analysis showed that males tend to have narrower petrotympanic fissures, in particular OR = 1.58 for right and OR = 1.5 for left petrotympanic fissure. The current study lends support to the conclusion that an enhanced multi-planar cone-beam computed tomography yields a clear depiction of the petrotympanic fissure's morphological characteristics. We have found that the morphology is neither gender nor age-related.

Groundwater-Mining-Induced Subsidence and Earth Fissures in Cedar Valley, Southwestern Utah

NASA Astrophysics Data System (ADS)

Knudsen, T. R.; Inkenbrandt, P.; Lund, W. R.; Lowe, M.; Bowman, S. D.

2014-12-01

Groundwater pumping in excess of recharge (groundwater mining) has lowered the potentiometric surface in Cedar Valley, southwestern Utah, by as much as 114 feet since 1939. Lowering the potentiometric surface (head decline) has caused permanent compaction of fine-grained sediments of the Cedar Valley aquifer. Recently acquired interferometric synthetic aperture radar (InSAR) imagery shows that land subsidence is occurring over an ~100 square-mile area, including two pronounced subsidence bowls in the northeastern (Enoch graben) and southwestern (Quichapa Lake area) parts of the valley. A lack of accurate historical benchmark elevation data over much of the valley prevents detailed long-term quantification of subsidence. In response to the land subsidence, earth fissures have formed along the margins of the Enoch graben and north and west of Quichapa Lake. Our initial inventory of Cedar Valley fissures, which relied on aerial-photography analysis, identified 3.9 miles of fissures in 2009. With newly acquired light detection and ranging (LiDAR) coverage in 2011, we more than doubled the total length of mapped fissures to 8.3 miles. Fissures on the west side of the Enoch graben exhibit ongoing vertical surface displacement with rates as high as 1.7 inches/year. The largest Enoch-graben-west fissure has displaced street surfaces, curb and gutter, and sidewalks, and has reversed the flow direction of a sewer line in a partially developed subdivision. Several Cedar Valley fissures are closely associated with, and in some places coincident with, mapped Quaternary faults. While the majority of Cedar Valley fissures are mapped in agricultural areas, continued groundwater mining and resultant subsidence will likely cause existing fissures to lengthen and new fissures to form that may eventually impact other developed areas of the valley.

Research on Integrated Geophysics Detect Potential Ground Fissure in City

NASA Astrophysics Data System (ADS)

Qian, R.

2017-12-01

North China confined aquifer lied 70 to 200 meters below the earth's surface has been exploited for several decades, which resulted in confined water table declining and has generated a mass of ground fissure. Some of them has reached the surface and the other is developing. As it is very difficult to stop the ground fissure coming into being, measures of avoiding are often taken. It brings great potential risk to urban architecture and municipal engineering. It is very important to find out specific distribution and characteristic of potential ground fissure in city with high resolution. The ground fissure is concealed, therefor, geophysical method is an important technology to detecting concealed ground fissure. However, it is very difficult to detect the characteristics of the superficial part of ground fissure directly, as it lies dozens of meters below and has only scores of centimeters fault displacement. This paper studies applied ground penetration radar, surface wave and shallow refleciton seismic to detect ground fissure. It sets up model of surface by taking advantage of high resolution of ground penetrating radar data, constrains Reilay wave inversion and improves its resolution. The high resolution reflection seismic is good at detecting the geology structure. The data processing and interpretation technique is developmented to avoid the pitfall and improve the aliability of the rusult. The experiment has been conducted in Shunyi District, Beijing in 2016. 5 lines were settled to collect data of integrated geophysical method. Development zone of concealed ground fissure was found and its ultra shallow layer location was detected by ground penetrating radar. A trial trench of 6 meters in depth was dug and obvious ground fissure development was found. Its upper end was 1.5 meters beneath the earth's surface with displacement of 0.3 meters. The favorable effect of this detection has provided a new way for detecting ground fissure in cities of China, such as Beijing and Xi'an etc. Keyword: Ground Fissure, GPR, Surface Wave; Shallow Reflection Seismic

Earth-Fissure Movements Associated with Fluctuations in Ground-Water Levels near the Picacho Mountains, South-Central Arizona, 1980-84

USGS Publications Warehouse

Carpenter, M.C.

1993-01-01

The Picacho earth fissure transects subsiding alluvial sediments near the east periphery of the Picacho basin in south-central Arizona. The basin has undergone land subsidence of as much as 3.8 meters since the 1930's owing to compaction of the aquifer system in response to ground-water-Ievel declines that have exceeded 100 meters. The fissure, which extends generally north-south for 15 kilometers, exhibits horizontal tensile failure and as much as 0.6 meter of normal dip-slip movement at the land surface. The west side of the fissure is down thrown. The fissure was observed as early as 1927 and is the longest earth fissure in Arizona. Vertical and horizontal displacements were monitored along a line normal to the fissure. The survey line extends from a bedrock outcrop in the Picacho Mountains on the east, past an observation well near the fissure, to a point 1,422 meters to the west. From May 1980 to May 1984, the downthrown west side of the fissure subsided 167+-1.8 millimeters and moved 18+-1.5 millimeters westward into the basin. Concurrently, the relatively upthrown east side subsided 148+-1.8 millimeters and moved 14+-1.5 millimeters westward. Dislocation modeling of deformation along the survey line near the fissure indicates that dip-slip movement has occurred along a vertical fault surface that extends from the land surface to a depth of about 300 meters. Slip was 9 millimeters from May to December 1980 and also 9 millimeters from March to November 1981. Continuous measurements were made of horizontal movement across the fissure using a buried invar-wire horizontal extensometer, while water-level fluctuations were continuously monitored in four piezometers nested in two observation wells. The range of horizontal movement was 4.620 millimeters, and the range of water-level fluctuation in the nearest piezometer in the deep alluvium was 9.05 meters. The maximum annual opening of the fissure during the study period was 3.740 millimeters from March to October 1981, while the water level declined 7.59 meters. The fissure closed 1.033 millimeters from October 1981 to March 1982, while the water level recovered 6.94 meters. Opening and closing of the fissure were smooth and were correlated with water-level decline and recovery, respectively, recorded in the nearby piezometers. Pearson correlation coefficients between the water-level fluctuations in the deeper piezometers and horizontal movement ranged from 0.913 to 0.925. The correlogram with water-level decline as ordinate and horizontal strain as abscissa exhibits hysteresis loops for annual cycles of water-level fluctuation as well as near-vertical excursions for shorter cycles of pumping and recovery. Vertical and horizontal displacements also were monitored along a second survey line 1 kilometer north of and nearly parallel to the first survey line. The north line extends from bedrock on the east across three fissures to a point 582 meters to the west but does not cross the Picacho earth fissure. From May 1980 to May 1984, the fissure farthest from the mountain front along this line exhibited 20+-1 millimeters of opening and 33.3+-1.1 millimeters of vertical offset; the west side of the fissure was downthrown. During the same period, the zone between this fissure and the mountain front exhibited compression. The hypothesis of generalized differential compaction is supported by data taken at the study site for several reasons. First, the vertical offset across fissures and the fit of deformation to a dislocation model are consistent with an elastic model of differential vertical movement deep in the alluvium. Second, correlation is high between horizontal movement across the Picacho earth fissure and water-level fluctuations in the deeper local piezometers. Third, correlation is high between horizontal movement across the fissure and compaction farther west in the basin. The hypothesis of rotation of a rigid plate is not supported because (1) fissures sometime

Automatic segmentation of pulmonary fissures in x-ray CT images using anatomic guidance

NASA Astrophysics Data System (ADS)

Ukil, Soumik; Sonka, Milan; Reinhardt, Joseph M.

2006-03-01

The pulmonary lobes are the five distinct anatomic divisions of the human lungs. The physical boundaries between the lobes are called the lobar fissures. Detection of lobar fissure positions in pulmonary X-ray CT images is of increasing interest for the early detection of pathologies, and also for the regional functional analysis of the lungs. We have developed a two-step automatic method for the accurate segmentation of the three pulmonary fissures. In the first step, an approximation of the actual fissure locations is made using a 3-D watershed transform on the distance map of the segmented vasculature. Information from the anatomically labeled human airway tree is used to guide the watershed segmentation. These approximate fissure boundaries are then used to define the region of interest (ROI) for a more exact 3-D graph search to locate the fissures. Within the ROI the fissures are enhanced by computing a ridgeness measure, and this is used as the cost function for the graph search. The fissures are detected as the optimal surface within the graph defined by the cost function, which is computed by transforming the problem to the problem of finding a minimum s-t cut on a derived graph. The accuracy of the lobar borders is assessed by comparing the automatic results to manually traced lobe segments. The mean distance error between manually traced and computer detected left oblique, right oblique and right horizontal fissures is 2.3 +/- 0.8 mm, 2.3 +/- 0.7 mm and 1.0 +/- 0.1 mm, respectively.

Retention of fissure sealants in young permanent molars affected by dental fluorosis: a 12-month clinical study.

PubMed

Hasanuddin, S; Reddy, E R; Manjula, M; Srilaxmi, N; Rani, S T; Rajesh, A

2014-10-01

To evaluate and compare retention and caries occurance following placement of Clinpro and FUJI VII fissure sealants, by two different techniques simultaneously in unsealed, contralateral young permanent molars of 7- to 10-year-old children affected by mild to moderate dental fluorosis at various recall intervals of 1 week, 1, 3, 6 and 12 months. 80 schoolchildren with mild to moderate dental fluorosis were assigned to Group A and Group B with 40 children in each group. In Group A Clinpro fissure sealant and in Group B Fuji VII fissure sealant was used. In both the groups fissure sealants were applied by conventional fissure sealant technique (CST) on one side and enameloplasty sealant technique (EST) on the other side of the same arch. The applied fissure sealants were evaluated clinically for retention and caries incidence. Clinpro fissure sealant showed a retention rate of 95% when compared with Fuji VII (57.5%) at the end of 12 months, which was statistically significant. Regarding techniques, EST showed better results than CST in both the groups. Comparison of groups with respect to retention and techniques at different time periods was performed using Mann-Whitney U test (p < 0.05). Comparison of different time periods with respect to retention and technique in all the groups was performed using Wilcoxon matched pairs test by ranks (p < 0.05). Clinpro fissure sealant showed better retention at all treatment intervals, when compared with Fuji VII. Further follow-up is required to study the efficacy of the fissure sealant placement techniques.

Effect of air abrasion and polishing on primary molar fissures.

PubMed

Lenzi, T L; Menezes, L B R; Soares, F Z M; Rocha, R O

2013-04-01

To evaluate the effect of air abrasion and polishing on primary molar fissures under light microscopy. 15 exfoliated primary second molars were longitudinally sectioned and photographed under a stereomicroscope (40×; baseline evaluation). Sections were then randomly allocated into one of the two groups (n = 15) and treated by either air abrasion (aluminium oxide jet) or air polishing (sodium bicarbonate jet) for 30 s. After treatment, sections were washed with an air/water spray, dried with absorbent paper, and photographed as previously described (final evaluation). Baseline and final morphology were compared by two blinded examiners who evaluated changes in the width and depth of fissures. The percentage of changed fissures was analysed, and the two treatments were compared using the Mann-Whitney test (α = 0.01). Both air systems resulted in fissure changes in most (93.3 %) of the sections. No significant differences in fissure width changes were found between treatments, but when changes in fissure depth were evaluated, air polishing was found to be less damaging than air abrasion (p < 0.01). Air abrasion and polishing cause changes to the anatomical configuration of occlusal fissures of primary molars.

Automatic lung lobe segmentation of COPD patients using iterative B-spline fitting

NASA Astrophysics Data System (ADS)

Shamonin, D. P.; Staring, M.; Bakker, M. E.; Xiao, C.; Stolk, J.; Reiber, J. H. C.; Stoel, B. C.

2012-02-01

We present an automatic lung lobe segmentation algorithm for COPD patients. The method enhances fissures, removes unlikely fissure candidates, after which a B-spline is fitted iteratively through the remaining candidate objects. The iterative fitting approach circumvents the need to classify each object as being part of the fissure or being noise, and allows the fissure to be detected in multiple disconnected parts. This property is beneficial for good performance in patient data, containing incomplete and disease-affected fissures. The proposed algorithm is tested on 22 COPD patients, resulting in accurate lobe-based densitometry, and a median overlap of the fissure (defined 3 voxels wide) with an expert ground truth of 0.65, 0.54 and 0.44 for the three main fissures. This compares to complete lobe overlaps of 0.99, 0.98, 0.98, 0.97 and 0.87 for the five main lobes, showing promise for lobe segmentation on data of patients with moderate to severe COPD.

Proximal lava drainage controls on basaltic fissure eruption dynamics

NASA Astrophysics Data System (ADS)

Jones, T. J.; Llewellin, E. W.; Houghton, B. F.; Brown, R. J.; Vye-Brown, C.

2017-11-01

Hawaiian basaltic eruptions commonly initiate as a fissure, producing fountains, spattering, and clastogenic lava flows. Most fissures rapidly localize to form a small number of eruptive vents, the location of which may influence the subsequent distribution of lava flows and associated hazards. We present results from a detailed field investigation of the proximal deposits of episode 1 of the 1969 fissure eruption of Mauna Ulu, Kīlauea, Hawai`i. Exceptional preservation of the deposits allows us to reconstruct vent-proximal lava drainage patterns and to assess the role that drainage played in constraining vent localization. Through detailed field mapping, including measurements of the height and internal depth of lava tree moulds, we reconstruct high-resolution topographic maps of the pre-eruption ground surface, the lava high-stand surface and the post-eruption ground surface. We calculate the difference in elevation between pairs of maps to estimate the lava inundation depth and lava drainage depth over the field area and along different segments of fissure. Aerial photographs collected during episode 1 of the eruption allow us to locate those parts of the fissure that are no longer exposed at the surface. By comparing with the inundation and drainage maps, we find that fissure segments that were inundated with lava to greater depths (typically 1-6 m) during the eruption later became foci of lava drainage back into the fissure (internal drain-back). We infer that, in these areas, lava ponding over the fissure suppressed discharge of magma, thereby favouring drain-back and stagnation. By contrast, segments with relatively shallow inundation (typically less than 1 m), such as where the fissure intersects pre-eruptive topographic highs, or where flow away from the vent (outflow) was efficient, are often associated with sub-circular vent geometries in the post-eruption ground surface. We infer that these parts of the fissure became localization points for ongoing magma ascent and discharge. We conclude that lava inundation and drainage processes in basaltic fissure eruptions can play an important role in controlling their localization and longevity.

Phreatic explosions during basaltic fissure eruptions: Kings Bowl lava field, Snake River Plain, USA

NASA Astrophysics Data System (ADS)

Hughes, Scott S.; Kobs Nawotniak, Shannon E.; Sears, Derek W. G.; Borg, Christian; Garry, William Brent; Christiansen, Eric H.; Haberle, Christopher W.; Lim, Darlene S. S.; Heldmann, Jennifer L.

2018-02-01

Physical and compositional measurements are made at the 7 km-long ( 2200 years B.P.) Kings Bowl basaltic fissure system and surrounding lava field in order to further understand the interaction of fissure-fed lavas with phreatic explosive events. These assessments are intended to elucidate the cause and potential for hazards associated with phreatic phases that occur during basaltic fissure eruptions. In the present paper we focus on a general understanding of the geological history of the site. We utilize geospatial analysis of lava surfaces, lithologic and geochemical signatures of lava flows and explosively ejected blocks, and surveys via ground observation and remote sensing. Lithologic and geochemical signatures readily distinguish between Kings Bowl and underlying pre-Kings Bowl lava flows, both of which comprise phreatic ejecta from the Kings Bowl fissure. These basalt types, as well as neighboring lava flows from the contemporaneous Wapi lava field and the older Inferno Chasm vent and outflow channel, fall compositionally within the framework of eastern Snake River Plain olivine tholeiites. Total volume of lava in the Kings Bowl field is estimated to be 0.0125 km3, compared to a previous estimate of 0.005 km3. The main (central) lava lake lost a total of 0.0018 km3 of magma by either drain-back into the fissure system or breakout flows from breached levees. Phreatic explosions along the Kings Bowl fissure system occurred after magma supply was cut off, leading to fissure evacuation, and were triggered by magma withdrawal. The fissure system produced multiple phreatic explosions and the main pit is accompanied by others that occur as subordinate pits and linear blast corridors along the fissure. The drop in magma supply and the concomitant influx of groundwater were necessary processes that led to the formation of Kings Bowl and other pits along the fissure. A conceptual model is presented that has relevance to the broader range of low-volume, monogenetic basaltic fissure eruptions on Earth, the Moon and other planetary bodies.

Effect of rotary instrumentation on composite bond strength with simulated pulpal pressure.

PubMed

Gupta, Ruchi; Tewari, Sanjay

2006-01-01

This study evaluated the effect of cutting teeth with different types of burs at various speeds on shear bond strength using Prime and Bond NT (Dentsply/DeTrey). A simulated pulpal pressure of 25-mmHg, equivalent to 34 cmH2O, was created in a false pulpal chamber filled with distilled water and maintained for seven days. The human teeth were divided into six groups of 10 teeth each: fine grit straight fissure diamond bur in air rotor (DA), fine grit straight fissure diamond bur in micromotor (DM), crosscut fissure carbide bur in air rotor (CCA), crosscut fissure carbide bur in micromotor (CCM), plain fissure carbide bur in micromotor (CM) and #600-grit silicon carbide paper (SiC). The tooth surfaces in these groups were cut under copious air-water spray and treated with Prime and Bond NT after etching with 38% phosphoric acid. Composite restorations were then prepared with TPH spectrum (Dentsply/ DeTrey). After soaking in water at 37 degrees C for 24 hours, the specimens were loaded at a 45 degrees angle to their longitudinal axes by using a Z 010 Universal Testing Machine (Zwick), and shear bond strengths were determined at a crosshead speed of 2 mm/minute. All of the specimens were then observed under Stereomicroscope at 10x. Statistical analysis was made using one-way and two-way ANOVA and t-test (p < 0.05). The bond strengths achieved with a fine grit straight fissure diamond bur, a crosscut fissure carbide bur in air rotor and a crosscut fissure carbide bur in micromotor, were significantly higher than a fine grit straight fissure diamond bur, a plain fissure carbide bur and #600-grit silicon carbide abrasive paper in the micromotor. Therefore, selecting an appropriate bur and its speed may improve bonding for adhesive systems, although crosscut fissure carbide burs produced high bond strengths at either speed used.

A new model for the growth of basaltic shields based on deformation of Fernandina volcano, Galápagos Islands

USGS Publications Warehouse

Bagnardi, Marco; Amelung, Falk; Poland, Michael P.

2013-01-01

Space-geodetic measurements of surface deformation produced by the most recent eruptions at Fernandina – the most frequently erupting volcano in the Galápagos Archipelago – reveal that all have initiated with the intrusion of subhorizontal sills from a shallow magma reservoir. This includes eruptions from fissures that are oriented both radially and circumferentially with respect to the summit caldera. A Synthetic Aperture Radar (SAR) image acquired 1–2 h before the start of a radial fissure eruption in 2009 captures one of these sills in the midst of its propagation toward the surface. Galápagos eruptive fissures of all orientations have previously been presumed to be fed by vertical dikes, and this assumption has guided models of the origin of the eruptive fissure geometry and overall development of the volcanoes. Our findings allow us to reinterpret the internal structure and evolution of Galápagos volcanoes and of similar basaltic shields. Furthermore, we note that stress changes generated by the emplacement of subhorizontal sills feeding one type of eruption may control the geometry of subsequent eruptive fissures. Specifically, circumferential fissures tend to open within areas uplifted by sill intrusions that initiated previous radial fissure eruptions. This mechanism provides a possible explanation for the pattern of eruptive fissures that characterizes all the western Galápagos volcanoes, as well as the alternation between radial and circumferential fissure eruptions at Fernandina. The same model suggests that the next eruption of Fernandina will be from a circumferential fissure in the area uplifted by the 2009 sill intrusion, just southwest of the caldera rim.

Mechanical Behavior of Brittle Rock-Like Specimens with Pre-existing Fissures Under Uniaxial Loading: Experimental Studies and Particle Mechanics Approach

NASA Astrophysics Data System (ADS)

Cao, Ri-hong; Cao, Ping; Lin, Hang; Pu, Cheng-zhi; Ou, Ke

2016-03-01

Joints and fissures with similar orientation or characteristics are common in natural rocks; the inclination and density of the fissures affect the mechanical properties and failure mechanism of the rock mass. However, the strength, crack coalescence pattern, and failure mode of rock specimens containing multi-fissures have not been studied comprehensively. In this paper, combining similar material testing and discrete element numerical method (PFC2D), the peak strength and failure characteristics of rock-like materials with multi-fissures are explored. Rock-like specimens were made of cement and sand and pre-existing fissures created by inserting steel shims into cement mortar paste and removing them during curing. The peak strength of multi-fissure specimens depends on the fissure angle α (which is measured counterclockwise from horizontal) and fissure number ( N f). Under uniaxial compressional loading, the peak strength increased with increasing α. The material strength was lowest for α = 25°, and highest for α = 90°. The influence of N f on the peak strength depended on α. For α = 25° and 45°, N f had a strong effect on the peak strength, while for higher α values, especially for the 90° sample, there were no obvious changes in peak strength with different N f. Under uniaxial compression, the coalescence modes between the fissures can be classified into three categories: S-mode, T-mode, and M-mode. Moreover, the failure mode can be classified into four categories: mixed failure, shear failure, stepped path failure, and intact failure. The failure mode of the specimen depends on α and N f. The peak strength and failure modes in the numerically simulated and experimental results are in good agreement.

Anal sphincter fibrillation: is this a new finding that identifies resistant chronic anal fissures that respond to botulinum toxin?

PubMed

Moon, A; Chitsabesan, P; Plusa, S

2013-08-01

Anal fissures can be resistant to treatment and some patients may undergo several trials of medical therapy before definitive surgery. It would be useful to identify predictors of poor response to medical therapy. This study assesses the role of anorectal physiological criteria to identify patients with anal fissure predicted to fail botulinum toxin (BT) treatment. A retrospective analysis of anorectal physiological data collected for patients with resistant chronic anal fissures, referred to one consultant surgeon between 2007 and 2011, was undertaken. These were correlated with treatment plans and healing rates. Twenty-five patients with idiopathic chronic anal fissures underwent anorectal physiology studies and were subsequently treated with BT injection. Eleven had a characteristic high-frequency low-amplitude 'saw tooth' waveform or anal sphincter fibrillation (ASF) and higher anal sphincter pressures. Nine (82%) of these patients had resolution of their anal fissure symptoms following treatment with BT. Of 14 patients with no evidence of ASF and a greater range of anal sphincter pressures, only one (7%) had resolution following BT. ASF appears to be an anorectal physiological criterion that helps predict response of anal fissures to BT injection. This could help streamline fissure management. © 2013 The Authors. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland.

Effect of Local Crystallographic Texture on the Fissure Formation During Charpy Impact Testing of Low-Carbon Steel

NASA Astrophysics Data System (ADS)

Ghosh, Abhijit; Patra, Sudipta; Chatterjee, Arya; Chakrabarti, Debalay

2016-06-01

The severity of the formation of fissures (also known as splitting or delamination) on the fracture surface of Charpy impact-tested samples of a low-carbon steel has been found to increase with the decrease in finish rolling temperature [1093 K to 923 K (820 °C to 650 °C)]. Combined scanning electron microscopy and electron back-scattered diffraction study revealed that crystallographic texture was the prime factor responsible for the fissure formation. Through-thickness texture band composed of cube [Normal Direction (ND)║<001>] and gamma [ND║<111>] orientations developed during the inter-critical rolling treatment. Strain incompatibility between these two texture bands causes fissure cracking on the main fracture plane. A new approach based on the angle between {001} planes of neighboring crystals has been employed in order to estimate the `effective grain size,' which is used to determine the cleavage fracture stress on different planes of a sample. The severity of fissure formation was found to be directly related to the difference in cleavage fracture stress between the `main fracture plane' and `fissure plane.' Clustering of ferrite grains having cube texture promoted the fissure crack propagation along the transverse `fissure plane,' by increasing the `effective grain size' and decreasing the cleavage fracture stress on that plane.

Monitoring on Xi'an ground fissures deformation with TerraSAR-X data

USGS Publications Warehouse

Zhao, C.; Zhang, Q.; Zhu, W.; Lu, Z.

2012-01-01

Owing to the fine resolution of TerraSAR-X data provided since 2007, this paper applied 6 TerraSAR data (strip mode) during 3rd Dec. 2009 to 23rd Mar. 2010 to detect and monitor the active fissures over Xi'an region. Three themes have been designed for high precision detection and monitoring of Xi'an-Chang'an fissures, as small baseline subsets (SBAS) to test the atmospheric effects of differential interferograms pair stepwise, 2-pass differential interferogram with very short baseline perpendicular to generate the whole deformation map with 44 days interval, and finally, corner reflector (CR) technique was used to closely monitor the relative deformation time series between two CRs settled crossing two ground fissures. Results showed that TerraSAR data are a good choice for small-scale ground fissures detection and monitoring, while special considerations should be taken for their great temporal and baseline decorrelation. Secondly, ground fissures in Xi'an were mostly detected at the joint section of stable and deformable regions. Lastly, CR-InSAR had potential ability to monitor relative deformation crossing fissures with millimeter precision.

Risk factors special to eastern culture for the development of anal fissure.

PubMed

Erel, Serap; Adahan, Didem; Kismet, Kemal; Caylan, Ayse; Tanrikulu, Yusuf; Akkus, Mehmet Ali

2009-01-01

To reveal the effect of diet, bowel functions and toilet habits on the development of anal fissure. One hundred patients complaining of anal fissure were included to the case group; and one hundred age- and gender-matched patients referred for other reasons except for anorectal complaints were included to the control group. The information was obtained by face to face interviews using questionnaires. Statistically significant differences were found in coffee, fruit, and meat consumption between the groups. The patients suffering from anal fissure avoided paprika consumption. The rate of anal fissure incidence was higher in squat toilet users. This study is the first study which evaluates the risk factors such as paprika consumption and squat toilet usage that are specific to Eastern culture. Further studies including large numbers of population are needed to evaluate different risk factors for anal fissure development (Tab. 2, Ref. 11). Full Text (Free, PDF) www.bmj.sk.

An Experimental and Numerical Study on Cracking Behavior of Brittle Sandstone Containing Two Non-coplanar Fissures Under Uniaxial Compression

NASA Astrophysics Data System (ADS)

Yang, Sheng-Qi; Tian, Wen-Ling; Huang, Yan-Hua; Ranjith, P. G.; Ju, Yang

2016-04-01

To understand the fracture mechanism in all kinds of rock engineering, it is important to investigate the fracture evolution behavior of pre-fissured rock. In this research, we conducted uniaxial compression experiments to evaluate the influence of ligament angle on the strength, deformability, and fracture coalescence behavior of rectangular prismatic specimens (80 × 160 × 30 mm) of brittle sandstone containing two non-coplanar fissures. The experimental results show that the peak strength of sandstone containing two non-coplanar fissures depends on the ligament angle, but the elastic modulus is not closely related to the ligament angle. With the increase of ligament angle, the peak strength decreased at a ligament angle of 60°, before increasing up to our maximum ligament angle of 120°. Crack initiation, propagation, and coalescence were all observed and characterized from the inner and outer tips of pre-existing non-coplanar fissures using photographic monitoring. Based on the results, the sequence of crack evolution in sandstone containing two non-coplanar fissures was analyzed in detail. In order to fully understand the crack evolution mechanism of brittle sandstone, numerical simulations using PFC2D were performed for specimens containing two non-coplanar fissures under uniaxial compression. The results are in good agreement with the experimental results. By analyzing the stress field, the crack evolution mechanism in brittle sandstone containing two non-coplanar fissures under uniaxial compression is revealed. These experimental and numerical results are expected to improve the understanding of the unstable fracture mechanism of fissured rock engineering structures.

Combined treatment approach to chronic anal fissure with associated anal fistula.

PubMed

FitzDowse, Andrew J; Behrenbruch, Corina C; Hayes, Ian P

2017-12-03

Anal fistula in association with chronic anal fissure (fissure-fistula) is infrequently described. Recognizing this association and managing both components may help prevent some treatment failures seen with chronic anal fissure. This study aims to report on the outcomes of 20 consecutive patients with fissure-fistula managed with fistulotomy and injection of botulinum A toxin. The study is a retrospective, observational study, assessing the success of symptom resolution following fistulotomy with botulinum A toxin, in patients identified as having a chronic anal fissure with associated anal fistula. The study included all patients with this condition treated with combination treatment by a single surgeon at a tertiary care hospital between January 2013 and January 2016. Twenty patients with fissure-fistula treated with fistulotomy and botulinum toxin A were identified. The median cohort age was 44 years (range 25-78), with a predominance of males (80%) and posterior fissure position (80%). The most common presenting symptoms were anal pain (70%), rectal bleeding (55%), anal discharge (35%) and anal pruritus (35%). Mean follow-up was 10.5 weeks and all patients who attended follow-up appointments reported resolution of symptoms. There were no cases of incontinence and none of the cohort required further surgical intervention for the condition. Chronic anal fissure with associated anal fistula can be successfully managed with fistulotomy and injection of botulinum toxin A. Further studies would be helpful in determining if recognition and management of the fistula component in isolation with fistulotomy is as effective as fistulotomy plus botulinum A toxin. © 2017 Royal Australasian College of Surgeons.

Numerical simulation of earth fissures caused by overly aquifer exploitation at Guangming Village, China

NASA Astrophysics Data System (ADS)

Ye, S.; Franceschini, A.; Zhang, Y.; Janna, C.; Gong, X.; Yu, J.; Teatini, P.

2017-12-01

Earth fissures accompanying anthropogenic land subsidence due to overly aquifer exploitation create significant geohazards in China. In the framework of an efficient and safe management of groundwater, numerical models represent a unique scientific approach to predict the generation and development of earth fissures. However, the common geomechanical simulators fail to reproduce fissure development because, due to compatibility conditions, they cannot be effectively applied in discontinuous mechanics. We present an innovative modelling approach for the simulation of fissure development. Firstly, a regional 3D groundwater model is calibrated on available piezometric records; secondly, the regional outcome is used to define the boundary conditions of a local 3D groundwater model developed at the fissure scale and implementing a refined discretization of the local hydrogeologic setting; finally, the pressure change are used as forcing factor in a local 3D geomechanical model, which combines Finite Elements and Interface Elements to simulate the deformation of the continuous aquifer system and the generation and sliding/opening of earth fissures The approach has been applied to simulate the earth fissure at Guangming Village in Wuxi, China with land subsidence of more than 1 m caused by the overexploitation of the second confined aquifer. The first earth fissure was observed in 1998. It developed fast from 1998 to 2007. The domain addressed by the local simulations is 2 km wide and 5 km long. The thickness of the aquifer system ranges from 0 m, in the proximity of a mountain ridge southward, to 210 m northward and includes a phreatic aquifer, the first and second confined aquifers, and four aquitards. The simulations spanned the period from 1980, i.e. before the inception of large groundwater withdrawals, to 2015. The modelling results highlight that the earth fissures at Guangming Village have been caused by tension and shear, which developed from the land surface downward. The main factors contributing to fissure generation include the shallow bedrock with a sharp ridge, the asymmetric shape of ridge, the uneven thickness of the sedimentary deposits at the west and east side of the buried ridge together with a different pressure change that have been responsible for differential land subsidence.

A secreted WNT-ligand-binding domain of FZD5 generated by a frameshift mutation causes autosomal dominant coloboma

PubMed Central

Liu, Chunqiao; Widen, Sonya A.; Williamson, Kathleen A.; Ratnapriya, Rinki; Gerth-Kahlert, Christina; Rainger, Joe; Alur, Ramakrishna P.; Strachan, Erin; Manjunath, Souparnika H.; Balakrishnan, Archana; Floyd, James A.; Li, Tiansen; Waskiewicz, Andrew; Brooks, Brian P.; Lehmann, Ordan J.; FitzPatrick, David R.; Swaroop, Anand

2016-01-01

Ocular coloboma is a common eye malformation resulting from incomplete fusion of the optic fissure during development. Coloboma is often associated with microphthalmia and/or contralateral anophthalmia. Coloboma shows extensive locus heterogeneity associated with causative mutations identified in genes encoding developmental transcription factors or components of signaling pathways. We report an ultra-rare, heterozygous frameshift mutation in FZD5 (p.Ala219Glufs*49) that was identified independently in two branches of a large family with autosomal dominant non-syndromic coloboma. FZD5 has a single-coding exon and consequently a transcript with this frameshift variant is not a canonical substrate for nonsense-mediated decay. FZD5 encodes a transmembrane receptor with a conserved extracellular cysteine rich domain for ligand binding. The frameshift mutation results in the production of a truncated protein, which retains the Wingless-type MMTV integration site family member-ligand-binding domain, but lacks the transmembrane domain. The truncated protein was secreted from cells, and behaved as a dominant-negative FZD5 receptor, antagonizing both canonical and non-canonical WNT signaling. Expression of the resultant mutant protein caused coloboma and microphthalmia in zebrafish, and disruption of the apical junction of the retinal neural epithelium in mouse, mimicking the phenotype of Fz5/Fz8 compound conditional knockout mutants. Our studies have revealed a conserved role of Wnt–Frizzled (FZD) signaling in ocular development and directly implicate WNT–FZD signaling both in normal closure of the human optic fissure and pathogenesis of coloboma. PMID:26908622

Shallow Subsurface transport and eruption of basaltic foam

NASA Astrophysics Data System (ADS)

Parcheta, C. E.; Mitchell, K. L.

2016-12-01

Volcanic fissure vents are difficult to quantify, and details of eruptive behavior are elusive even though it is the most common eruption mechanism on Earth and across the solar system. A fissure's surface expression is typically concealed, but when a fissure remains exposed, its subsurface conduit can be mapped post-eruptively with VolcanoBot. The robot uses a NIR structured light sensor that reproduces a 3D surface model to cm-scale accuracy, documenting the shallow conduit. VolcanoBot3 has probed >1000m3 of volcanic fissure vents at the Mauna Ulu fissure system on Kilauea. Here we present the new 3D model of a flared vent on the Mauna Ulu fissure system. We see a self-similar pattern of irregularities on the fissure walls throughout the entire shallow subsurface, implying a fracture mechanical origin similar to faults. These irregularities are typically 1 m across, protrude 30 cm horizontally into the drained fissure, and have a vertical spacing of 2-3 m. However, irregularity size is variable and distinct with depth, potentially reflecting stratigraphy in the wall rock. Where piercing points are present, we infer the dike broke the wall rock in order to propagate upwards; where they are not, we infer that syn-eruptive mechanical erosion has taken place. One mechanism for mechanical erosion is supersonic shocks, which may occur in Hawaiian fountains. We are calculating the speed of sound in 64% basaltic foam, which appears to be the same velocity (or slightly slower) than inferred eruption velocities. Irregularities are larger than the maximum 10% wall roughness used in engineering fluid dynamic studies, indicating that magma fluid dynamics during fissure eruptions are probably not as passive nor as simple as previously thought. We are currently using the mapped conduit geometries and derived speed of sound for basaltic foam in fluid dynamical modeling of fissure-fed lava fountains.

A One-Year Evaluation of a Free Fissure Sealant Program

PubMed Central

M, Bakhtiar; N, Azadi; A, Golkari

2016-01-01

Statement of Problem: Pit and fissure sealant therapy has been approved as an effective measure in the prevention of occlusal dental caries. Resin based materials are the most common materials used worldwide. A variety of resin based fissure sealants are produced and used. Most of them have been presented with ideal results in research environment. However, their effectiveness in the real life, especially in a mass application program such as Iran’s oral health reform plan is not clear. Objectives: To evaluate the longevity of different fissure sealant applied in Iran’s oral health reform plan in Fars Province (south of Iran) after one year. Materials and Methods: Seven counties were selected. One hundred 6- to 8-year-old school children who had undergone fissure sealant therapy in spring 2015 were randomly selected from each county. Their first molars were examined to evaluate the status of the fissure sealants which were applied one year ago. Data on the type/brand of fissure sealant materials, type and experience of clinicians who applied them, existence of a chair-side assistant, and whether the children were caries-free at the time of fissure sealant application were collected from the existing reports. Results: Data of 1974 teeth from 598 children were used for the final analysis. The effects of type/brand of the material was significant on the final results and remained significant (p < 0.001) after adjustments for the level of fluoride, urban/rural area, upper/lower jaw, type of clinician who applied the sealant, existence of a chair-side assistant, and child’s gender, age, and being caries-free. Conclusions: Many factors affect the success rate of a fissure sealant therapy program. The type/brand of the material remained significantly related to the success rate of the fissure sealant even after adjustments for other influencing factors. In this study, ClinproTM Sealant (3M/ESPE, USA) showed better longevity after one year of application. PMID:28959758

A One-Year Evaluation of a Free Fissure Sealant Program.

PubMed

M, Bakhtiar; N, Azadi; A, Golkari

2016-12-01

Pit and fissure sealant therapy has been approved as an effective measure in the prevention of occlusal dental caries. Resin based materials are the most common materials used worldwide. A variety of resin based fissure sealants are produced and used. Most of them have been presented with ideal results in research environment. However, their effectiveness in the real life, especially in a mass application program such as Iran's oral health reform plan is not clear. To evaluate the longevity of different fissure sealant applied in Iran's oral health reform plan in Fars Province (south of Iran) after one year. Seven counties were selected. One hundred 6- to 8-year-old school children who had undergone fissure sealant therapy in spring 2015 were randomly selected from each county. Their first molars were examined to evaluate the status of the fissure sealants which were applied one year ago. Data on the type/brand of fissure sealant materials, type and experience of clinicians who applied them, existence of a chair-side assistant, and whether the children were caries-free at the time of fissure sealant application were collected from the existing reports. Data of 1974 teeth from 598 children were used for the final analysis. The effects of type/brand of the material was significant on the final results and remained significant ( p < 0.001) after adjustments for the level of fluoride, urban/rural area, upper/lower jaw, type of clinician who applied the sealant, existence of a chair-side assistant, and child's gender, age, and being caries-free. Many factors affect the success rate of a fissure sealant therapy program. The type/brand of the material remained significantly related to the success rate of the fissure sealant even after adjustments for other influencing factors. In this study, ClinproTM Sealant (3M/ESPE, USA) showed better longevity after one year of application.

A study on using texture analysis methods for identifying lobar fissure regions in isotropic CT images.

PubMed

Wei, Q; Hu, Y

2009-01-01

The major hurdle for segmenting lung lobes in computed tomographic (CT) images is to identify fissure regions, which encase lobar fissures. Accurate identification of these regions is difficult due to the variable shape and appearance of the fissures, along with the low contrast and high noise associated with CT images. This paper studies the effectiveness of two texture analysis methods - the gray level co-occurrence matrix (GLCM) and the gray level run length matrix (GLRLM) - in identifying fissure regions from isotropic CT image stacks. To classify GLCM and GLRLM texture features, we applied a feed-forward back-propagation neural network and achieved the best classification accuracy utilizing 16 quantized levels for computing the GLCM and GLRLM texture features and 64 neurons in the input/hidden layers of the neural network. Tested on isotropic CT image stacks of 24 patients with the pathologic lungs, we obtained accuracies of 86% and 87% for identifying fissure regions using the GLCM and GLRLM methods, respectively. These accuracies compare favorably with surgeons/radiologists' accuracy of 80% for identifying fissure regions in clinical settings. This shows promising potential for segmenting lung lobes using the GLCM and GLRLM methods.

[Fissures in biliary calculi. Personal contribution (author's transl)].

PubMed

Nano, M; Potenzoni, F; Camandona, M; Casalegno, P A

1979-04-01

In a series of 70 patients suffering from biliary lithiasis, the roentgenologic findings of fissures in the calculi was observed in 5 cases examined by means of cholecystography and in 7 cases who underwent cholangiocholecystography. Fissures were demonstrated 11 times in calculi after surgery. The "Mercedes-Benz" sign was never observed at the abdominal examination without contrast medium. The presence of fissures may be an additional sign in the radiologic diagnosis of biliary calculi, but its value is not determinant.

Randomized clinical trial of transcutaneous electrical posterior tibial nerve stimulation versus lateral internal sphincterotomy for treatment of chronic anal fissure.

PubMed

Youssef, Tamer; Youssef, Mohamed; Thabet, Waleed; Lotfy, Ahmed; Shaat, Reham; Abd-Elrazek, Eman; Farid, Mohamed

2015-10-01

The objective of this study was to evaluate the efficacy of transcutaneous electrical posterior tibial nerve stimulation in treatment of patients with chronic anal fissure and to compare it with the conventional lateral internal sphincterotomy. Consecutive patients with chronic anal fissure were randomly allocated into two treatment groups: transcutaneous electrical posterior tibial nerve stimulation group and lateral internal sphincterotomy group. The primary outcome measures were number of patients with clinical improvement and healed fissure. Secondary outcome measures were complications, VAS pain scores, Wexner's constipation and Peascatori anal incontinence scores, anorectal manometry, and quality of life index. Seventy-three patients were randomized into two groups of 36 patients who were subjected to transcutaneous electrical nerve stimulation and 37 patients who underwent lateral internal sphincterotomy. All (100%) patients in lateral internal sphincterotomy group had clinical improvement at one month following the procedure in contrast to 27 (75%) patients in transcutaneous electrical nerve stimulation group. Recurrence of anal fissure after one year was reported in one (2.7%) and 11 (40.7%) patients in lateral internal sphincterotomy and transcutaneous electrical nerve stimulation groups respectively. Resting anal pressure and functional anal canal length were significantly reduced after lateral internal sphincterotomy. Transcutaneous electrical posterior tibial nerve stimulation for treatment of chronic anal fissure is a novel, non-invasive procedure and has no complications. However, given the higher rate of clinical improvement and fissure healing and the lower rate of fissure recurrence, lateral internal sphincterotomy remains the gold standard for treating chronic anal fissure. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Maps showing water-level declines, land subsidence, and earth fissures in south-central Arizona

USGS Publications Warehouse

Laney, R.L.; Raymond, R.H.; Winikka, C.C.

1978-01-01

From 1915 to 1975, more than 109 million acre-feet of ground water was withdrawn from about 4,500 square miles in Pinal and Maricopa Counties in south-central Arizona. The volume of water withdrawn greatly exceeds the volume of natural recharge, and water levels have been declining since 1923. As a result of the water-level declines, the land surface has subsided, the alluvial deposits have been subjected to stress, and earth fissures have developed. Land subsidence and earth fissures have damaged public and private properties. Subsidence and fissures will continue to occur as long as ground water is being mined and water levels continue to decline. As urban development expands, land subsidence and earth fissures will have an increasing socioeconomic impact. Information on maps includes change in water levels, measurements of land subsidence, and location of earth fissures. A section showing land subsidence between Casa Grande and the Picacho Peak Interchange also is included. Scale 1:250,000. (Woodard-USGS)

The immediate and long-term effects of invasive and noninvasive pit and fissure sealing techniques on the microflora in occlusal fissures of human teeth.

PubMed

Kramer, P F; Zelante, F; Simionato, M R

1993-01-01

The purpose of this study was to evaluate the effect of acid conditioning and occlusal sealant on microbial colonization of pit and fissures submitted to ameloplasty or left intact. Human enamel blocks containing fissures prepared from the occlusal surfaces of unerupted third molars were implanted in occlusal fillings in molars of 12 patients for seven, 30, 60, and 120 days. After seven days of exposure to the oral environment, the pit and fissure blocks were removed and found to be colonized, mainly with gram-positive coccal flora. The acid-etching procedure itself reduced the number of cultivable microorganisms by about 95%. Subsequent application of occlusal sealant caused a gradual decrease of the remaining viable microorganism throughout the experiment. Despite the decrease of 100% after acid etching in most of the fissures submitted to ameloplasty, the occlusal sealant did not lead to a subsequent significant reduction.

Ultrasound Fissure Observation: Assessment of Lung by Pleural-Hub Affiliates.

PubMed

Zanforlin, Alessandro; Livi, Vanina; Santoriello, Carlo; Ceruti, Paolo; Trigiani, Marco; Valerio, Manlio; Perani, Cristiano; Carlucci, Paolo; Palmiotti, Antonio; Marchetti, Giampietro

2018-02-22

Lung ultrasound examination is becoming an even more important part of pulmonologists' clinical routine. As indicated in the literature, the coordinates of any findings on lung parenchyma are based on surface landmarks or conventional quadrants. In our experience we have noticed that lung fissures are clearly detectable as interruptions of the pleural line, but this has never been investigated previously. The aim of this study was to evaluate whether lung fissures are detectable under normal conditions in routine clinical practice. Ten operators were enrolled from Pleural-Hub, a scientific discussion group. After compiling a prestudy survey to investigate whether they had observed fissures previously, they were asked to note if the following fissures were detectable: posterior right (PR) and left (PL), lateral right (LR) and left (LL), anterior right (AR), and anterolateral left (AL). Enrollment was competitive, aiming to reach 100 case subjects. We found that general fissure detection was 61.3%, in particular: PR, 59%; LR, 75%; AR, 69%; PL, 45%; LL, 64%; AL, 56%. Single operators yielded different detection rates ranging from 90% to 25%, showing strong operator dependency. Before being made aware of general results operators indicated operator's skill and rib shadow artifacts as the principal factors affecting fissure detection. Lung fissures may be detected with ultrasound once adequate training is provided. This may allow the clinician a more precise anatomical delineation of pathology identified by lung ultrasound. Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Fine Mapping and Introgressing a Fissure Resistance Locus

USDA-ARS?s Scientific Manuscript database

Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in rice kernels that increase breakage among kernels when transported or milled, which decrease the value of processed rice. This study employed molecular gene tagging methods to ...

[Application of individually designed trans-fissure approach in brain surgery: analysis of 90 cases].

PubMed

Zhao, Ji-Zong; Wang, Shuo; Zhang, Mao-Zhi; Wang, Lei; Wang, Rong; Tang, Ya-Juan

2009-01-06

To explore the feasibility and value of trans-fissure approaches in brain surgery through individually designed craniotomy. Ninety patients with intracranial space-occupying lesions, 47 males and 58 females, aged (43 +/- 14) (1 - 68), were treated by individualized trans-fissure approach surgeries. Linear scalp incision or "horseshoe shape" scalp incision were designed to perform the operation, with a bone flap 3 - 4 cm in diameter. The shortest approach to reach the lesion was decided under the guidance of neuro-navigation and real-time B-mode ultrasonography. Then the lesions were removed through natural cortical fissures. Another 79 patients with intracranial space-occupying lesions, 53 males and 51 females, aged (42 +/- 11) (15 -73), undergoing classical surgeries in the same period were used as control group. The average operation time, size of bone flap, amount of blood loss, hospitalization time, and hospitalization cost were compared between these 2 groups. The operation time of the individually designed trans-fissure approach group was (3.1 +/- 1.6) hours (1.33 - 10.83 hours), significantly shorter than that of the control group [(4.8 +/- 1.9) hrs, P < 0.05]. The amount of blood loss of the individually designed trans-fissure approach group was (173 +/- 168) ml (20 m - 500 ml), significantly less than that of the control group [(410 +/- 61) ml, P < 0.01]. The size of bone flap of the individually designed trans-fissure approach group was (12 +/- 5) cm2 [(1 - 25) cm2], significantly smaller than that of the control group [(20. +/- 9) cm2, P < 0.01]. Four of the 90 patients of the individually designed trans-fissure approach group received retransfusion, compared to 15 in the control group, during operation. No infection or other significant complications occurred after operation in the individually designed trans-fissure approach group. The hospitalization time of the individually designed trans-fissure approach group was (20 +/- 6) days (9 - 39 days), significantly shorter than that of the control group [(24 +/- 7) days, P < 0.01]. The average hospitalization cost of the individually designed trans-fissure approach group was (23171 +/- 7280) yuan RMB; significantly lower than that of the control group [(28096 +/- 10822) yuan, P < 0.01]. One of the land markers of minimally invasive neurosurgery, individualized trans-fissure approach has been proved to be an effective minimally invasive approach that leads to better outcome and fewer complications after operation.

Transperineal sonographic anal sphincter complex evaluation in chronic anal fissures.

PubMed

Bedair, Elsaid M; El Hennawy, Hany M; Moustafa, Ahmed Abdu; Meki, Gad Youssef; Bosat, Bosat Elwany

2014-11-01

The purpose of this study was to assess the role of transperineal sonography in assessment of pathologic changes to the anal sphincter complex in patients with chronic anal fissures. We conducted a prospective case-control study of 100 consecutive patients of any age and both sexes with chronic anal fissures who presented to a colorectal clinic between January 2012 and August 2013 (group A) and 50 healthy volunteers (group B). The most common patterns of radiologic changes to anal sphincters associated with chronic anal fissures were circumferential thickening of the anal sphincter complex in 5 patients (5%), circumferential thickening of the internal anal sphincter in 3 patients (3%), preferential thickening of the internal anal sphincter at the 6-o'clock position in 80 patients (80%) and the 12-o'clock position in 7 patients (7%), preferential thickening of the internal and external anal sphincters in 3 patients (3%), and thinning of the internal anal sphincter in 2 patients (2%). Chronic anal fissures cause differential thickening of both internal and external anal sphincters, with a trend toward increased thickness in relation to the site of the fissure. Routine preoperative transperineal sonography for patients with chronic anal fissures is recommended, and it is mandatory in high-risk patients. © 2014 by the American Institute of Ultrasound in Medicine.

Anomalous sylvian fissure morphology in Williams syndrome.

PubMed

Eckert, Mark A; Galaburda, Albert M; Karchemskiy, Asya; Liang, Alyssa; Thompson, Paul; Dutton, Rebecca A; Lee, Agatha D; Bellugi, Ursula; Korenberg, Julie R; Mills, Debra; Rose, Fredric E; Reiss, Allan L

2006-10-15

The unusual sensitivity and attraction to auditory stimuli in people with Williams syndrome (WS) has been hypothesized to be the consequence of atypical development of brain regions surrounding the Sylvian fissure. Planum temporale surface area, which is determined in part by Sylvian fissure patterning, was examined in 42 WS and 40 control participants to determine if anomalous Sylvian fissure morphology is present in WS. WS participants had significantly reduced leftward asymmetry of the planum temporale compared to control participants, due to a significant expansion in the size of the right planum temporale. The increased right planum temporale size was largely due to WS participants (24%) who had a right hemisphere Sylvian fissure that coursed horizontally and failed to ascend into the parietal lobe. This sulcal pattern is unusual in the right hemisphere and is more commonly found in the left hemisphere of typically developing individuals. There were no control participants with this type of right hemisphere Sylvian fissure pattern. The right hemisphere Sylvian fissure sulcal patterns were also related to a measure of cortical complexity and the amount of right hemisphere occipital lobe volume, suggesting that intrinsic genetic influences leading to anomalous visual system development in WS have widespread influences on cortical morphology that are similar in manner to extrinsic embryonic visual system lesions.

Treatment of anal fissures using a combination of minoxidil and lignocaine: a randomized, double-blind trial.

PubMed

Muthukumarassamy, Rajakannu; Robinson, Smile S; Sarath, Sistla Chandra; Raveendran, R

2005-01-01

Anal fissures are associated with hypertonia of the internal anal sphincter and pain. We evaluated the efficacy of local application of a combination of minoxidil and lignocaine in healing anal fissures. In this prospective, randomized, double-blind study, 90 patients with anal fissure were recruited. Patients received local applications of ointments containing 5% lignocaine (n=28), 0.5% minoxidil (n=36), or both (n=26). Healing of anal fissure at 6 weeks was used as the primary end-point. Rates of complete healing of fissure were similar in the three groups (lignocaine alone 8/27, minoxidil alone 10/34, combination 7/22; p=ns). Mean (SD) time taken for complete healing with combination treatment [1.9 (0.6) weeks] was significantly shorter than that with minoxidil alone (3.1 [1.7] weeks; p=0.001) or with lignocaine alone (3.3 [0.8] weeks; p=0.002). Rates of pain relief were similar in the three groups. Stoppage of bleeding occurred more often with combination treatment than with lignocaine alone. No patient had systemic or local side effects. Combination treatment with minoxidil and lignocaine helps in faster healing of anal fissures and provides better symptomatic relief than either drug alone.

Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

NASA Astrophysics Data System (ADS)

Amrani, Salah

La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues fabriquees industriellement. Cette technique a consiste a determiner le profil des differentes proprietes physiques. En effet, la methode basee sur la mesure de la distribution de la resistivite electrique sur la totalite de l'echantillon est la technique qui a ete utilisee pour localiser la fissuration et les macro-pores. La microscopie optique et l'analyse d'image ont, quant a elles, permis de caracteriser les zones fissurees tout en determinant la structure des echantillons analyses a l'echelle microscopique. D'autres tests ont ete menes, et ils ont consiste a etudier des echantillons cylindriques d'anodes de 50 mm de diametre et de 130 mm de longueur. Ces derniers ont ete cuits dans un four a UQAC a differents taux de chauffage dans le but de pouvoir determiner l'influence des parametres de cuisson sur la formation de la fissuration dans ce genre de carottes. La caracterisation des echantillons d'anodes cuites a ete faite a l'aide de la microscopie electronique a balayage et de l'ultrason. La derniere partie des travaux realises a l'UQAC contient une etude sur la caracterisation des anodes fabriquees au laboratoire sous differentes conditions d'operation. L'evolution de la qualite de ces anodes a ete faite par l'utilisation de plusieurs techniques. L'evolution de la temperature de refroidissement des anodes crues de laboratoire a ete mesuree; et un modele mathematique a ete developpe et valide avec les donnees experimentales. Cela a pour objectif d'estimer la vitesse de refroidissement ainsi que le stress thermique. Toutes les anodes fabriquees ont ete caracterisees avant la cuisson par la determination de certaines proprietes physiques (resistivite electrique, densite apparente, densite optique et pourcentage de defauts). La tomographie et la distribution de la resistivite electrique, qui sont des techniques non destructives, ont ete employees pour evaluer les defauts internes des anodes. Pendant la cuisson des anodes de laboratoire, l'evolution de la resistivite electrique a ete suivie et l'etape de devolatilisation a ete identifiee. Certaines anodes ont ete cuites a differents taux de chauffage (bas, moyen, eleve et un autre combine) dans l'objectif de trouver les meilleures conditions de cuisson en vue de minimiser la fissuration. D'autres anodes ont ete cuites a differents niveaux de cuisson, cela dans le but d'identifier a quelle etape de l'operation de cuisson la fissuration commence a se developper. Apres la cuisson, les anodes ont ete recuperees pour, a nouveau, faire leur caracterisation par les memes techniques utilisees precedemment. L'objectif principal de cette partie etait de reveler l'impact de differents parametres sur le probleme de fissuration, qui sont repartis sur toute la chaine de production des anodes. Le pourcentage de megots, la quantite de brai et la distribution des particules sont des facteurs importants a considerer pour etudier l'effet de la matiere premiere sur le probleme de la fissuration. Concernant l'effet des parametres du procede de fabrication sur le meme probleme, le temps de vibration, la pression de compaction et le procede de refroidissement ont ete a la base de cette etude. Finalement, l'influence de la phase de cuisson sur l'apparition de la fissuration a ete prise en consideration par l'intermediaire du taux de chauffage et du niveau de cuisson. Les travaux realises au niveau industriel ont ete faits lors d'une campagne de mesure dans le but d'evaluer la qualite des anodes de carbone en general et l'investigation du probleme de fissuration en particulier. Ensuite, il s'agissait de reveler les effets de differents parametres sur le probleme de la fissuration. Vingt-quatre anodes cuites ont ete utilisees. Elles ont ete fabriquees avec differentes matieres premieres (brai, coke, megots) et sous diverses conditions (pression, temps de vibration). Le parametre de la densite de fissuration a ete calcule en se basant sur l'inspection visuelle de la fissuration des carottes. Cela permet de classifier les differentes fissurations en plusieurs categories en se basant sur certains criteres tels que le type de fissures (horizontale, verticale et inclinee), leurs localisations longitudinales (bas, milieu et haut de l'anode) et transversales (gauche, centrale et droite). Les effets de la matiere premiere, les parametres de fabrication des anodes crues ainsi que les conditions de cuisson sur la fissuration ont ete etudies. La fissuration des anodes denses en carbones cause un serieux probleme pour l'industrie d'aluminium primaire. La realisation de ce projet a permis la revelation de differents mecanismes de fissuration, la classification de fissuration par plusieurs criteres (position, types localisation) et l'evaluation de l'impact de differents parametres sur la fissuration. Les etudes effectuees dans le domaine de cuisson ont donne la possibilite d'ameliorer l'operation et reduire la fissuration des anodes. Le travail consiste aussi a identifier des techniques capables d'evaluer la qualite d'anodes (l'ultrason, la tomographie et la distribution de la resistivite electrique). La fissuration des anodes en carbone est consideree comme un probleme complexe, car son apparition depend de plusieurs parametres repartis sur toute la chaine de production. Dans ce projet, plusieurs nouvelles etudes ont ete realisees, et elles permettent de donner de l'originalite aux travaux de recherches faits dans le domaine de la fissuration des anodes de carbone pour l'industrie de l'aluminium primaire. Les etudes realisees dans ce projet permettent d'ajouter d'un cote, une valeur scientifique pour mieux comprendre le probleme de fissuration des anodes et d'un autre cote, d'essayer de proposer des methodes qui peuvent reduire ce probleme a l'echelle industrielle.

The prevalence of dental caries and fissure sealants in 12 year old children by disadvantaged status in Dublin (Ireland).

PubMed

Sagheri, D; McLoughlin, J; Clarkson, J J

2009-03-01

The aim was to record dental caries levels and the presence of fissure sealants in 12-year-old schoolchildren whose domestic water supply had been fluoridated since birth in Dublin (Ireland). Cross-sectional study. Participants A representative, random sample of 12-year-old schoolchildren in north-west Dublin. Dental caries levels were recorded using WHO criteria and fissure sealant was recorded when sealant was detectable on a permanent molar tooth. Medical card ownership, as a surrogate for disadvantage, was recorded by use of a questionnaire. Three-hundred and thirty-two (332) children were examined. The mean DMFT was 0.80 (SD 1.24). Analysis (Mann-Whitney U test) based on stratification of the sample according to medical-card status revealed no statistically significant difference between DMFT median scores of children of medical-card holders (i.e., social disadvantage background) and non medical-card holders (p-value = 0.23). However, the data revealed a social gradient in the presence of at least one fissure sealant. Approximately 10% more children in the group of medical-card holders had no fissure sealants present. Fisher's exact test was used to examine the association between the absence of fissure sealants and at least one fissure sealant between the two groups and was considered to be statistically significant (p-value = 0.04). This study demonstrated a social gradient in the presence of fissure sealants, but no such gradient in dental caries levels. This demonstrates the importance of population-based measures in the prevention of dental caries, such as water fluoridation, in reducing oral health inequalities.

Preserving rice quality: fine mapping and introgressing a fissure resistance locus

USDA-ARS?s Scientific Manuscript database

Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in the rice kernels that increase the percentage of breakage among the kernels when they are transported and milled, which decreases the value of processed rice. This study employ...

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conditioner. (a) Identification. A pit and fissure sealant and conditioner is a device composed of resin, such...

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conditioner. (a) Identification. A pit and fissure sealant and conditioner is a device composed of resin, such...

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant and...

Focal dilation and paradoxical collapse of cortical fissures and sulci in patients with normal-pressure hydrocephalus.

PubMed

Holodny, A I; George, A E; de Leon, M J; Golomb, J; Kalnin, A J; Cooper, P R

1998-11-01

The authors describe a subgroup of patients with shunt-proven normal-pressure hydrocephalus (NPH) who presented with focal fissural and sulcal dilation on imaging studies. The specific radiological features and methods of differentiating this condition from cortical atrophy are delineated. Normal-pressure hydrocephalus has been described as dilation of the ventricles that is out of proportion to the sulci. Sulcal dilation has been taken as evidence of cortical atrophy and has even been used as a criterion to exclude patients from undergoing a shunting procedure. The authors describe five cases of patients with shunt-proven NPH who presented with focal dilation of cortical fissures and sulci. In three of the cases, there was a paradoxical decrease in the size of the dilated fissures and sulci that paralleled the decrease in the size of the lateral ventricles following successful shunting. This study demonstrates that focal fissural and sulcal dilation may represent reservoirs of cerebrospinal fluid analogous to the ventricular system. Patients should not be denied a shunting procedure solely on the basis of focally dilated fissures of sulci.

Adaptive Management of Land Subsidence and Ground Fissuring in the Chino Groundwater Basin, California

NASA Astrophysics Data System (ADS)

Malone, A.; Rolfe, T.; Wildermuth, M.; Kavounas, P.

2014-12-01

The Chino Basin, located in southern California, is a large alluvial groundwater basin with storage in excess of five million acre-feet. The basin has a long history of groundwater development for various uses dating back to the early 1900s. As a result, piezometric heads declined basin-wide during the past century - in some areas by more than 200 feet. Declines of this magnitude typically cause irreversible aquifer-system compaction, which in turn results in subsidence at the ground surface. In portions of Chino Basin, land subsidence has been differential and accompanied by ground fissuring, which damaged existing infrastructure and poses concerns for new and existing development.Chino Basin Watermaster, the agency responsible for groundwater basin management, has recognized that land subsidence and ground fissuring should be minimized to the extent possible. At the same time, Watermaster is implementing aggressive groundwater-supply programs that include controlled overdraft and the possibility of causing head declines in areas prone to subsidence and fissuring. The groundwater-supply programs must also address the subsidence and fissuring phenomena.From 2001 to 2005, Watermaster conducted a technical investigation to characterize the extent, rate, and mechanisms of subsidence and fissuring. The investigation employed InSAR and ground-level surveying of benchmarks to monitor ground-surface deformation, and borehole extensometers and piezometric monitoring to establish the relationships between groundwater production, piezometric levels, and aquifer-system deformation. Based on the results of the investigation, Watermaster developed: (i) subsidence-management criteria for the areas experiencing acute subsidence and fissuring, and (ii) an adaptive management program to minimize the potential for future subsidence and fissuring across the entire Chino Basin. The science-based program includes ongoing monitoring, which now includes sophisticated fissure-monitoring techniques, data analysis, annual reporting, and adjustment to the program as warranted by the data.

Microhardness evaluation of enamel adjacent to an improved GIC sealant after different enamel pre-treatment procedures.

PubMed

Haznedaroglu, E; Sozkes, S; Mentes, A R

2014-12-01

This in vitro study was carried out to evaluate the microhardness of enamel adjacent to a glass ionomer cement (GIC) with high fluoride content used as a sealant (Fuji Triage, GC Corp., Japan) after laser, bur or air abrasion treatment procedures. 200 freshly extracted non-carious human molars were divided into 10 experimental groups according to the enamel pre-treatment method: A air abrasion (Mach 4.1 Kreativ Inc., USA); AP, Air abrasion + conditioning with 20% polyacrylic acid (GC cavity conditioner); L, Er,Cr:YSGG laser application (Waterlase, Biolase Technology, Inc., San Clemente, USA); LP, Er,Cr:YSGG laser application and fissure conditioning; B, ameloplasty carried out with a diamond bur especially designed for preparing fissures (Komet #8833); BP, ameloplasty + fissure conditioning; P, application of 20% polyacrylic acid and all fissures sealed with GIC; C, no fissure treatment, the material was applied directly to the fissures (control); R, application of 37% orthophosphoric acid and fissures sealed with a resin-based sealant (Fissurit; Voco, Germany) (control); N, no treatment (control). Half of each group of teeth were left in artificial saliva for one month and the rest for three months. The teeth were then sectioned and microhardness was measured using a Vickers test apparatus. Kruskal-Wallis, Mann-Whitney U and Dunn's multiple comparison tests were carried out (5% significance). After one month results regarding hardness at the base and lateral walls of fissures were significantly higher in groups A, AP, L, LP, B, BP, P and C than in groups R and N (p<0.01), but no difference was seen between the treatment procedures. The results after three months produced similar findings with evenly increased values for all groups. The results of this study showed that the tested GIC with a higher fluoride content seemed to improve the enamel hardness of the fissure enamel and could be regarded as an alternative material in cases where resin sealant applications are questionable.

Novel QTLs affecting rice kernel fissure resistance discovered in the cultivar ‘Saber’ augment those from ‘Cybonnet’

USDA-ARS?s Scientific Manuscript database

Kernel fissures in rice (Oryza sativa L.) caused by pre- or post-harvest stresses are the leading cause of breakage among milled rice. Such breakage causes economic losses for producers, millers, and marketers. Five QTLs for kernel fissure resistance (FR) were identified among a set of 275 RILs de...

Fine mapping and introgressing qFIS1-2, a major QTL for kernel fissure resistance in rice (Oryza sativa L.)

USDA-ARS?s Scientific Manuscript database

Rice (Oryza sativa L.) kernel fissuring increases breakage during milling and decreases the value of processed rice. This study employed molecular gene tagging methods to fine-map a fissure resistance (FR) locus in ‘Cybonnet’, a semidwarf tropical japonica cultivar, as well as transfer this trait to...

Haemorrhoids and anal fissures during pregnancy and after childbirth: a prospective cohort study.

PubMed

Poskus, T; Buzinskienė, D; Drasutiene, G; Samalavicius, N E; Barkus, A; Barisauskiene, A; Tutkuviene, J; Sakalauskaite, I; Drasutis, J; Jasulaitis, A; Jakaitiene, A

2014-12-01

To identify the incidence and risk factors of haemorrhoids and fissures during pregnancy and after childbirth. Prospective observational cohort study. University hospital and outpatient clinics in Lithuania. A total of 280 pregnant women followed up until 1 month after delivery. Women were examined four times through pregnancy and after delivery; those that developed peri-anal diseases were compared with those that did not. Incidence, time and risk factors of haemorrhoids and fissures. In all, 123 (43.9%) women developed peri-anal disease: 1.6% in the first trimester, 61% during the third trimester, 34.1% after delivery and 3.3% 1 month after delivery; 114 (40.7%) women were diagnosed with haemorrhoids, seven (2.5%) with haemorrhoids and anal fissure and two (0.71%) with anal fissure. Ninety-nine (80.5%) women had vaginal delivery and 24 (19.5%) women had undergone caesarean section. Multivariate analysis identified personal history of peri-anal diseases (odds ratio [OR] 11.93; 95% confidence interval [95% CI] 2.18-65.30), constipation (OR 18.98; 95% CI 7.13-50.54), straining during delivery for more than 20 minutes (OR 29.75; 95% CI 4.00-221.23) and birthweight of newborn>3800 g (OR 17.99; 95% CI 3.29-98.49) as significant predictors of haemorrhoids and anal fissures during pregnancy and perinatal period. Haemorrhoids and fissures are common during the last trimester of pregnancy and 1 month after delivery, with constipation, personal history of haemorrhoids or fissures, birthweight of newborn>3800 g, straining during delivery for more than 20 minutes being independently associated risk factors. © 2014 Royal College of Obstetricians and Gynaecologists.

Minimally Invasive Exposure of the Maxillary Artery at the Anteromedial Infratemporal Fossa.

PubMed

Rodriguez Rubio, Roberto; Kola, Olivia; Tayebi Meybodi, Ali; Tabani, Halima; Feng, Xuequan; Burkhardt, Jan-Karl; Yousef, Sonia; Lawton, Michael T; Benet, Arnau

2018-04-12

The maxillary artery (MA) has been described as a reliable donor for extracranial-intracranial high-flow bypass. Existing techniques to harvest MA require brain retraction and drilling of the middle fossa (with or without a zygomatic osteotomy), carrying the potential risks of venous bleeding, injury to the branches of the maxillary or mandibular nerves, muscular transection, or temporomandibular junction disorders. To describe a novel technique to expose the MA without bony drilling and with minimal impact to surrounding structures. A conventional curvilinear incision was performed in 10 cadaveric specimens, prior to elevating the scalp to expose the zygomatic root and lateral orbital rim. The sphenozygomatic suture was followed to the anterolateral edge of the inferior orbital fissure (IOF) to locate and harvest the pterygoid segment of the MA. Topographic anatomy was assessed using surrounding landmarks and 3D Cartesian coordinates to define the surgical area. The number of visible MA branches and their lengths were recorded. The MA was successfully exposed in all specimens. This approach allowed 6 branches of MA to be exposed. The average length of exposure was 23.3 ± 8.3 mm and the average surgical area was 2.8 ± 0.9 cm2. The IOF was 11.5 ± 4.2 mm from the MA. Our technique provides landmarks to identify the distal pterygoid segment of MA as a donor for extracranial-intracranial bypasses without the need for additional craniectomies. Clear anatomical landmarks, including the sphenozygomatic suture, anterolateral edge of IOF, infraorbital artery, and the pterygomaxillary fissure defined a trajectory to efficiently localize the MA with minimal risk to surrounding structures.

The pattern of circumferential and radial eruptive fissures on the volcanoes of Fernandina and Isabela islands, Galapagos

USGS Publications Warehouse

Chadwick, W.W.; Howard, K.A.

1991-01-01

Maps of the eruptive vents on the active shield volcanoes of Fernandina and Isabela islands, Galapagos, made from aerial photographs, display a distinctive pattern that consists of circumferential eruptive fissures around the summit calderas and radial fissures lower on the flanks. On some volcano flanks either circumferential or radial eruptions have been dominant in recent time. The location of circumferential vents outside the calderas is independent of caldera-related normal faults. The eruptive fissures are the surface expression of dike emplacement, and the dike orientations are interpreted to be controlled by the state of stress in the volcano. Very few subaerial volcanoes display a pattern of fissures similar to that of the Galapagos volcanoes. Some seamounts and shield volcanoes on Mars morphologically resemble the Galapagos volcanoes, but more specific evidence is needed to determine if they also share common structure and eruptive style. ?? 1991 Springer-Verlag.

The effects of dietary biotin supplementation on vertical fissures of the claw wall in beef cattle.

PubMed Central

Campbell, J R; Greenough, P R; Petrie, L

2000-01-01

A clinical field trial was performed on a herd of Hereford beef cows in central Saskatchewan. The herd had a history of being severely affected with vertical fissures. The objective of the study was to determine the effects of supplemental dietary biotin on the prevalence of vertical fissures in beef cows. In June 1994 and June 1995, 1- and 2-year-old heifers were randomly allocated into 2 treatment groups, each composed of 79 animals. One group received a 10 mg/head/day biotin-supplemented free-choice mineral supplement, while the other groups received an identical free-choice mineral without the biotin supplementation. The claws from these animals were evaluated in June 1994, October 1994, June 1995, October 1995, and June 1996 for the presence of vertical fissures. Supplemental dietary biotin significantly increased serum levels of biotin and significantly increased claw hardness in supplemented cows. Both groups of heifers started the trial without vertical fissures. After 18 months, 15% of the cows fed supplemental dietary biotin had vertical fissures compared with 33% in the nonsupplemented group. The difference was statistically significant (P = 0.01). PMID:10992986

Robust pulmonary lobe segmentation against incomplete fissures

NASA Astrophysics Data System (ADS)

Gu, Suicheng; Zheng, Qingfeng; Siegfried, Jill; Pu, Jiantao

2012-03-01

As important anatomical landmarks of the human lung, accurate lobe segmentation may be useful for characterizing specific lung diseases (e.g., inflammatory, granulomatous, and neoplastic diseases). A number of investigations showed that pulmonary fissures were often incomplete in image depiction, thereby leading to the computerized identification of individual lobes a challenging task. Our purpose is to develop a fully automated algorithm for accurate identification of individual lobes regardless of the integrity of pulmonary fissures. The underlying idea of the developed lobe segmentation scheme is to use piecewise planes to approximate the detected fissures. After a rotation and a global smoothing, a number of small planes were fitted using local fissures points. The local surfaces are finally combined for lobe segmentation using a quadratic B-spline weighting strategy to assure that the segmentation is smooth. The performance of the developed scheme was assessed by comparing with a manually created reference standard on a dataset of 30 lung CT examinations. These examinations covered a number of lung diseases and were selected from a large chronic obstructive pulmonary disease (COPD) dataset. The results indicate that our scheme of lobe segmentation is efficient and accurate against incomplete fissures.

Differential compaction mechanism for earth fissures near Casa Grande, Arizona.

USGS Publications Warehouse

Jachens, R.C.; Holzer, T.L.

1982-01-01

Precise gravity measurements indicate that earth fissures or tension cracks caused by ground-water withdrawal within a 10km2 area SE of Casa Grande are associated with relief on the buried interface between the alluvial aquifer and underlying bedrock. These relations suggest that the fissures are forming in response to localized differential compaction caused by localized variations of aquifer-system thickness. -from Authors

Radiological anatomy assessment of the fissura pterygomaxillaris for a surgical approach to ganglion pterygopalatinum.

PubMed

Puche-Torres, Miguel; Blasco-Serra, Arantxa; Campos-Peláez, Ana; Valverde-Navarro, Alfonso A

2017-12-01

The ganglion pterygopalatinum has become a therapeutic target to treat various pain syndromes in recent years. It is located in the fossa pterygopalatina, and the fissura pterygomaxillaris is the main access to surgically approach this structure. Recently, the neuromodulation of the ganglion pterygopalatinum by microstimulator implantation has become the first therapeutic line in refractory cluster headache treatment. This invasive technique is performed transorally through the fissura pterygomaxillaris, and is limited by the size of the implantation device, which requires an opening of at least 2 mm. Therefore, extensive knowledge about the anatomy of the fissura pterygomaxillaris prior to surgery is necessary to predict the success of both the approach and intervention. Likewise, establishing a morphological typology of the different fissura pterygomaxillaris variations would be a valuable predictive tool in the clinical practice. In this work, an anatomical analysis was performed of the morphological characteristics of the 242 fissurae pterygomaxillares, which corresponded to 121 adult patients, 58 males and 63 females, aged between 18 and 87 years. For each subject, right and left fissures were studied with radiological computed tomography images. Aperture fissura pterygomaxillaris measurements were taken in an upper (Measure A), middle (Measure B) and lower craneo-caudal third (Measure C). Intra-subject differences were studied between the measurements taken of each patient's right and left fissures, and the inter-subject measures in which fissures were compared according to patients' age and gender. The obtained results showed no significant differences between each patient's right and left fissures in any three measurements taken. Intra-subject differences were not significant for gender or age. No statistically significant differences were found for the inter-subject measures between the measures of fissures according to patients' age. However, our data revealed that males' fissurae pterygomaxillares were significantly larger than those of females in all three measures. Having analysed fissures, a typological classification was made according to the morphological patterns found. A 2-mm limiting measure was considered, and Measures A, B and C of each fissure were classified depending on whether they had a value above or equal to 2 mm, or below 2 mm. With this classification criterion, four fissurae pterygomaxillares types were obtained. Type I and II fissure values (with a higher prevalence) were equal to or were greater than 2 mm in all three measures, or in two measures. Type III fissure values were only greater than or equal to 2 mm in Measure A, whereas all the Type IV fissure values were below 2 mm. Future studies are necessary to correlate the fissure types successfully proposed in the surgical ganglion pterygopalatinum approach. © 2017 Anatomical Society.

The flow mechanism in the Chalk based on radio-isotope analyses of groundwater in the London Basin

USGS Publications Warehouse

Downing, R.A.; Pearson, F.J.; Smith, D.B.

1979-01-01

14C analyses of groundwaters from the Chalk of the London Basin are re-interpreted and the age of the groundwater is revised. Radio-isotope analyses are used to examine the flow mechanism in the aquifer. The evidence supports the view that a network of micro-fissures and larger intergranular pores in the matrix provides a significant part of the water pumped from Chalk wells and the major fissures distribute the water to the wells. Most of the matrix is fine-grained and contains a very old water. This diffuses into the micro-fissures and larger pores and is carried to the wells by the major fissures. ?? 1979.

Fundal variations in the eyes of the osteoglossomorph fishes.

PubMed

Saidel, W M; Braford, M R

1985-01-01

The appearance of the fundus of the eye varies among the families of osteoglossomorph teleosts. In this study, four different fundal patterns were observed: (i) an anteroposterior (or horizontal) embryonic fissure with a septal falciform process (family Osteoglossidae); (ii) an embryonic fissure from the optic disc nasoventrally with a falciform process (family Arapaimidae); (iii) an embryonic fissure nasoventrally from the optic disc without a falciform process (family Hiodontidae); and (iv) neither an embryonic fissure nor a falciform process (families Notopteridae and Mormyridae). The distribution of these various forms among the osteoglossomorph fishes is consistent with the recent cladogram for the Osteoglossomorpha [Lauder and Liem, 1983] which was based on many characters. The embryonic fissure in adult Amia calva was also examined. Its existence in adult Amia, in most Osteoglossomorpha, and in many non-euteleostean bony fishes suggests that its persistence in the adult stage is a primitive trait of bony fishes, and its absence in the Notopteroidei (with the exception of Hiodon) is a derived condition.

Natural Treatments for Fissure in Ano Used by Traditional Persian Scholars, Razi (Rhazes) and Ibn Sina (Avicenna)

PubMed Central

Derakhshan, Ali Reza

2016-01-01

Most cases of chronic fissure do not respond to medical treatment. Razi and Ibn Sina were 2 of the best-known scientists of ancient Persia. The purpose of this study was to find out new scientific evidence in modern medicine about their recommendations, in order to find certain clues to conduct useful researches in the future. First, treatments of anal fissure mentioned by Razi and Ibn Sina were reviewed. Then, literature search was made in electronic databases including PubMed, Scopus, and Google Scholar. Management of anal fissure according to Razi’s and Ibn Sina’s practices is done based on 3 interventions: lifestyle modifications, drug treatments, and manual procedures. Almost all remedies suggested by Razi and Ibn Sina have shown their effects on fissure in ano via several mechanisms of action in many in vitro and in vivo studies; Still there is lack of human studies on the subject. PMID:27279645

Microleakage and penetration depth of different fissure sealant materials after cyclic thermo-mechanic and brushing simulation.

PubMed

Hatirli, Hüseyin; Yasa, Bilal; Yasa, Elif

2018-01-30

The aim of the study was to evaluate microleakage and the penetration-depths of different fissure-sealant materials applied with/without enameloplasty after cyclic aging. One-hundred-sixty mandibular molars were divided into non-invasive and enameloplasty preparation groups and eight material subgroups, including: flowable composites (microhyrid, nanohybrid, and nanofilled), three resin-based (unfilled, filled, and highly-filled), a giomer-based, and a glass-ionomer-based fissure sealant. Specimens were subjected to two-year cyclic chewing and brushing simulation. After 5% basic-fuchsin dye penetration, specimens were sectioned and scored under stereomicroscope. Kruskal-Wallis statistical data showed that preparation type significantly affected the penetration of all tested materials (p<0.05), but not significantly affected microleakage (p>0.05). Flowable composites showed the best and the glass-ionomer-based sealant showed the worst penetration and microleakage. Slight preparation of fissures is not important in microleakage. However, enameloplasty significantly enhanced the depth of penetration of the sealants. Flowable composites offer promising results at the fissure sealing.

Natural Treatments for Fissure in Ano Used by Traditional Persian Scholars, Razi (Rhazes) and Ibn Sina (Avicenna).

PubMed

Derakhshan, Ali Reza

2016-06-08

Most cases of chronic fissure do not respond to medical treatment. Razi and Ibn Sina were 2 of the best-known scientists of ancient Persia. The purpose of this study was to find out new scientific evidence in modern medicine about their recommendations, in order to find certain clues to conduct useful researches in the future. First, treatments of anal fissure mentioned by Razi and Ibn Sina were reviewed. Then, literature search was made in electronic databases including PubMed, Scopus, and Google Scholar. Management of anal fissure according to Razi's and Ibn Sina's practices is done based on 3 interventions: lifestyle modifications, drug treatments, and manual procedures. Almost all remedies suggested by Razi and Ibn Sina have shown their effects on fissure in ano via several mechanisms of action in many in vitro and in vivo studies; Still there is lack of human studies on the subject. © The Author(s) 2016.

Hawaiian fissure fountains: Quantifying vent and shallow conduit geometry, episode 1 of the 1969-1974 Mauna Ulu eruption: Chapter 17

USGS Publications Warehouse

Parcheta, Carolyn; Fagents, Sarah; Swanson, Donald A.; Houghton, Bruce F.; Ericksen, Todd; Carey, Rebecca; Cayol, Valérie; Poland, Michael P.; Weis, Dominique

2015-01-01

Geometries of shallow magmatic pathways feeding volcanic eruptions are poorly constrained, yet many key interpretations about eruption dynamics depend on knowledge of these geometries. Direct quantification is difficult because vents typically become blocked with lava at the end of eruptions. Indirect geophysical techniques have shed light on some volcanic conduit geometries, but the scales are too coarse to resolve narrow fissures (widths typically 1 m). Kīlauea's Mauna Ulu eruption, which started with <50 m high Hawaiian fountains along a 4.5 km fissure on 24 May 1969, provides a unique opportunity to measure the detailed geometry of a shallow magmatic pathway, as the western vents remain unobstructed to depths >30 m. Direct measurements at the ground surface were augmented by tripod-mounted lidar measurements to quantify the shallow conduit geometry for three vents at a resolution <4 cm. We define the form of the fissure in terms of aspect ratio, flaring ratio, irregularity, sinuosity, and segmentation and discuss the factors influencing these parameters. In the past, simplified first-order fissure geometries have been used in computational modeling. Our data can provide more accurate conduit shapes for better understanding of shallow fissure fluid dynamics and how it controls eruptive behavior, especially if incorporated into computer models.

Deformation at longyao ground fissure and its surroundings, north China plain, revealed by ALOS PALSAR PS-InSAR

NASA Astrophysics Data System (ADS)

Yang, Chengsheng; Lu, Zhong; Zhang, Qin; Zhao, Chaoying; Peng, Jianbing; Ji, Lingyun

2018-05-01

The Longyao ground fissure (LGF) is the longest and most active among more than 1000 ground fissures on the North China Plain. There have been many studies on the formation mechanism of the LGF, due to its scientific importance and its potential for damage to the environment. These studies have been based on both regional tectonic analysis and numerical simulations. In order to provide a better understanding of the formation mechanism, the deformation of the crack and its surrounding environment should be taken into consideration. In this paper, PS-InSAR technology was employed to assess the ground deformation of LGF and its surrounding area, using L-band ALOS-1 PALSAR images from 2007 to 2011. The characteristics of ground deformation, relationships between fissure activity and surrounding faults and groundwater exploitation were analyzed. This study shows that the north side of Longyao fault (LF) is uplifting while the south side is subsiding. This provides the tectonic conditions responsible for the activity of the ground fissure. Local groundwater exploitation also plays an important role in the development of ground fissures. InSAR observations were modeled to infer the loading depth (-2.8 km) and the slip rate (31.1 mm/yr) of LF.

Crustal flushing and its relationship to magnetic and hydrothermal processes on the East Pacific Rise crest

NASA Technical Reports Server (NTRS)

Wright, Dawn J.; Haymon, Rachel M.; Fornari, Daniel J.

1995-01-01

The deep-towed Argo I optical/acoustical vehicle and a geographic information system (GIS) have been used to establish the abundance, widths, and spatial distribution of fissures, as well as the relative age distribution of lavas along the narrow (less than 500 m wide) axial zone of the East Pacific Rise (EPR) from 9 deg 12 min to 9 deg 54 min N. On a second-order scale (approximately 78 km long), wider but less numerous fissures are found in the northern portion of the survey area; this changes to narrower, more abundant fissures in the south. A profile of the cumulative width added by fissures to the axial zone exhibits minima in three areas along strike (near 9 deg 49 min, 9 deg 35 min, and 9 deg 15 min N), where the most recent eruptions have occurred above sites of magmatic injection from the upper mantle, filling and covering older fissures. On a fourth-order scale (5-15 km long) the mean density of fissuring on a given segment is greater where relative axial lava age is greater. Fissure density also correlates with hydrothermal vent abundance and type. Increased cracking toward segment tips is observed at the second-order scale, whereas fourth-order segments tend to be more cracked in the middle. Cracking on a fourth-order scale may be driven by the propagation of dikes, rather than by the far-field plate stresses. The above relations constrain the model of Haymon et al. (1991) in which individual fourth-order segments are in different phases of a volcanic-hydrothermal-tectonic cycle.

Hawaiian fissure fountains 1: decoding deposits-episode 1 of the 1969-1974 Mauna Ulu eruption

USGS Publications Warehouse

Parcheta, C.E.; Houghton, Bruce F.; Swanson, D.A.

2012-01-01

Deposits from episode 1 of the 1969–1974 Mauna Ulu eruption of Kīlauea provide an exceptional opportunity to study processes of low intensity Hawaiian fissure fountains. Episode 1 lava flows passed through dense forest that had little impact on flow dynamics; in contrast, the pattern of spatter preservation was strongly influenced by the forest (through the formation of tree molds) and the preexisting topography. A low, near-continuous spatter rampart is present upwind and upslope, on the north side of the fissure. Most of the pyroclastic products, however, fell downwind to the south of the fissure, but little was preserved due to two processes: (1) incorporation of proximal spatter in rheomorphic lava flows 10–20 m from the vents, and (2) the downslope transport of cooler spatter falling on top of these flows beyond 20 m from vent. The lava flow field itself shows a complex history. Initially, discharge from the fissure exceeded the transport capacity of the southern drainage pathways, and lava ponded dynamically to a maximum height of 4 m for 40–120 min, until fountains began to decline. During declining discharge, lava flowed both southward away from the fissure and increasingly back into the vents. There is a clear “lava-shed” or delineation between where lava drained northwards back into the fissure, and where it continued flowing to the south. The 1969 deposits suggest that care is needed when products of less well-documented eruptions are analyzed, as postdepositional transport of spatter may preclude the formation of classic paired (symmetrical) ramparts.

Monitoring of land subsidence and ground fissures in Xian, China 2005-2006: Mapped by sar Interferometry

USGS Publications Warehouse

Zhao, C.Y.; Zhang, Q.; Ding, X.-L.; Lu, Z.; Yang, C.S.; Qi, X.M.

2009-01-01

The City of Xian, China, has been experiencing significant land subsidence and ground fissure activities since 1960s, which have brought various severe geohazards including damages to buildings, bridges and other facilities. Monitoring of land subsidence and ground fissure activities can provide useful information for assessing the extent of, and mitigating such geohazards. In order to achieve robust Synthetic Aperture Radar Interferometry (InSAR) results, six interferometric pairs of Envisat ASAR data covering 2005–2006 are collected to analyze the InSAR processing errors firstly, such as temporal and spatial decorrelation error, external DEM error, atmospheric error and unwrapping error. Then the annual subsidence rate during 2005–2006 is calculated by weighted averaging two pairs of D-InSAR results with similar time spanning. Lastly, GPS measurements are applied to calibrate the InSAR results and centimeter precision is achieved. As for the ground fissure monitoring, five InSAR cross-sections are designed to demonstrate the relative subsidence difference across ground fissures. In conclusion, the final InSAR subsidence map during 2005–2006 shows four large subsidence zones in Xian hi-tech zones in western, eastern and southern suburbs of Xian City, among which two subsidence cones are newly detected and two ground fissures are deduced to be extended westward in Yuhuazhai subsidence cone. This study shows that the land subsidence and ground fissures are highly correlated spatially and temporally and both are correlated with hi-tech zone construction in Xian during the year of 2005–2006.

Lateral internal sphincterotomy for surgically recurrent chronic anal fissure.

PubMed

Liang, Jennifer; Church, James M

2015-10-01

Lateral internal sphincterotomy cures chronic anal fissure by preventing internal sphincter hypertonia. However, cutting sphincter predisposes to sphincter dysfunction, manifests as incontinence of gas, liquid, or stool. Surgeons, therefore, can be too cautious in its use, making ineffective superficial incisions or avoiding the operation altogether. This study is designed to confirm the role of redo lateral internal sphincterotomy in the treatment of surgically recurrent chronic anal fissure. Patients undergoing repeat lateral internal sphincterotomy for surgically recurrent chronic anal fissure were accessed from a prospectively maintained database. Chronicity was defined by symptoms persisting more than 3 weeks. Contralateral sphincterotomy was performed with electrocautery through a stab incision over the intersphincteric plane. The length of sphincter division was the same as the length of the fissure. Phone questionnaire was administered and fecal continence was assessed by modified Cleveland Clinic Incontinence Score. Patients were asked to rank their overall satisfaction with the operation, and pre- and postoperative quality of life. There were 57 patients, 24 women and 33 men; mean age was 47.9 ± 14.8 years. Mean follow-up was 12.5 ± 4.2 years (range 6.2 to 25.2 years). Presenting symptoms included pain (100%), bleeding (80%), pruritus ani (39%), constipation (26%), and diarrhea. Fifty patients (90%) presented with 1 fissure, and 40 were posterior. Most procedures were performed on an outpatient basis. Fissure healing rate was 98%, and 2 patients (4%) developed minor incontinence postoperatively (one of gas, the other, gas and seepage). Overall satisfaction was 9.7 ± .9 out of 10 with a significant improvement in the quality of life from 5.7 ± 2.4 out of 10 to 9.3 ± 1.4 out of 10 (P < .001). Judicious repeat lateral sphincterotomy cures recurrent chronic fissures with minimal risk of incontinence. Copyright © 2015 Elsevier Inc. All rights reserved.

High-resolution AUV mapping of the 2015 flows at Axial Seamount, Juan de Fuca Ridge

NASA Astrophysics Data System (ADS)

Paduan, J. B.; Chadwick, W. W., Jr.; Clague, D. A.; Le Saout, M.; Caress, D. W.; Thomas, H. J.; Yoerger, D.

2016-12-01

Lava flows erupted in April 2015 at Axial Seamount were mapped at 1-m resolution with the AUV Sentry in August 2015 and the MBARI Mapping AUVs in July 2016 and observed and sampled with ROVs on those same expeditions. Thirty percent of terrain covered by new flows had been mapped by the MBARI AUVs prior to the eruption. Differencing of before and after maps (using ship-collected bathymetry where the AUV had not mapped before) allows calculation of extents and volumes of flows and shows new fissures. The maps reveal unexpected fissure patterns and shifts in the style of flow emplacement through a single eruption. There were 11 separate flows totaling 1.48 x 108 m3 of lava erupted from numerous en echelon fissures over 19 km on the NE caldera floor, on the NE flank, and down the N rift zone. Flows in and around the caldera have maximum thicknesses of 5-19 m. Most erupted as sheet flows and spread along intricate channels that terminated in thin margins. Some utilized pre-existing fissures. Some flows erupted from short fissures, while at least two longer new fissures produced little or no lava. A flow on the upper N rift has a spectacular lava channel flanked by narrow lava pillars supporting a thin roof left after the flow drained. A shatter ring still emanating warm fluid is visible in the map as a 15-m wide low cone. Hundreds of exploded pillows were observed but are not discernable in the bathymetry. The northern-most three flows deep on the N rift are similar in area to the others but comprise the bulk of the eruption volume. Differencing of ship-based bathymetry shows only these flows. Near the eruptive fissures they are sheet flows, but as they flowed downslope they built complexes of coalesced pillow mounds up to 67-128 m thick. Changes in flow morphology occurred through the course of the eruption. Large pillow mounds had molten cores that deformed as the eruption progressed. One flow began as a thin, effusive sheet flow but as the eruption rate decreased, a pillow mound built over the fissure. As the eruption waned on the caldera floor, near the fissure a small inflated margin developed on top of channels from an earlier phase of the flow. Several landslides occurred at the caldera wall. One is near where a 2015 fissure on the caldera floor cut through the caldera-bounding fault into the flank of the volcano.

Increased anal basal pressure in chronic anal fissures may be caused by overreaction of the anal-external sphincter continence reflex.

PubMed

van Meegdenburg, Maxime M; Trzpis, Monika; Heineman, Erik; Broens, Paul M A

2016-09-01

Chronic anal fissure is a painful disorder caused by linear ulcers in the distal anal mucosa. Even though it counts as one of the most common benign anorectal disorders, its precise etiology and pathophysiology remains unclear. Current thinking is that anal fissures are caused by anal trauma and pain, which leads to internal anal sphincter hypertonia. Increased anal basal pressure leads to diminished anodermal blood flow and local ischemia, which delays healing and leads to chronic anal fissure. The current treatment of choice for chronic anal fissure is either lateral internal sphincterotomy or botulinum toxin injections. In contrast to current thinking, we hypothesize that the external, rather than the internal, anal sphincter is responsible for increased anal basal pressure in patients suffering from chronic anal fissure. We think that damage to the anal mucosa leads to hypersensitivity of the contact receptors of the anal-external sphincter continence reflex, resulting in overreaction of the reflex. Overreaction causes spasm of the external anal sphincter. This in turn leads to increased anal basal pressure, diminished anodermal blood flow, and ischemia. Ischemia, finally, prevents the anal fissure from healing. Our hypothesis is supported by two findings. The first concerned a chronic anal fissure patient with increased anal basal pressure (170mmHg) who had undergone lateral sphincterotomy. Directly after the operation, while the submucosal anesthetic was still active, basal anal pressure decreased to 80mmHg. Seven hours after the operation, when the anesthetic had completely worn off, basal anal pressure increased again to 125mmHg, even though the internal anal sphincter could no longer be responsible for the increase. Second, in contrast to previous studies, recent studies demonstrated that botulinum toxin influences external anal sphincter activity and, because it is a striated muscle relaxant, it seems reasonable to presume that it affects the striated external anal sphincter, rather than the smooth internal anal sphincter. If our hypothesis is proved correct, the treatment option of lateral internal sphincterotomy should be abandoned in patients suffering from chronic anal fissures, since it fails to eliminate the cause of high anal basal pressure. Additionally, lateral internal sphincterotomy may cause damage to the anal-external sphincter continence reflex, resulting in fecal incontinence. Instead, higher doses of botulinum toxin should be administered to those patients suffering from chronic anal fissure who appeared unresponsive to lower doses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Earth fissures and localized differential subsidence

USGS Publications Warehouse

Holzer, Thomas L.; Pampeyan, Earl H.

1981-01-01

Long linear tension cracks associated with declining groundwater levels at four sites in subsiding areas in south-central Arizona, Fremont Valley, California, and Las Vegas Valley, Nevada, occur near points of maximum convex-upward curvature in subsidence profiles oriented perpendicular to the cracks. Profiles are based on repeated precise vertical control surveys of lines of closely spaced bench marks. Association of these fissures with zones of localized differential subsidence indicates that linear earth fissures are caused by horizontal tensile strains probably resulting from localized differential compaction. Horizontal tensile strains across the fissures at the point of maximum convex-upward curvature, ranging from approximately 100 to 700 microstrains (0.01 to 0.07% per year), were indicated based on measurements with a tape or electronic distance meter.

Engineering a robotic approach to mapping exposed volcanic fissures

NASA Astrophysics Data System (ADS)

Parcheta, C. E.; Parness, A.; Mitchell, K. L.

2014-12-01

Field geology provides a framework for advanced computer models and theoretical calculations of volcanic systems. Some field terrains, though, are poorly preserved or accessible, making documentation, quantification, and investigation impossible. Over 200 volcanologists at the 2012 Kona Chapman Conference on volcanology agreed that and important step forward in the field over the next 100 years should address the realistic size and shape of volcanic conduits. The 1969 Mauna Ulu eruption of Kīlauea provides a unique opportunity to document volcanic fissure conduits, thus, we have an ideal location to begin addressing this topic and provide data on these geometries. Exposed fissures can be mapped with robotics using machine vision. In order to test the hypothesis that fissures have irregularities with depth that will influence their fluid dynamical behavior, we must first map the fissure vents and shallow conduit to deci- or centimeter scale. We have designed, constructed, and field-tested the first version of a robotic device that will image an exposed volcanic fissure in three dimensions. The design phase included three steps: 1) create the payload harness and protective shell to prevent damage to the electronics and robot, 2) construct a circuit board to have the electronics communicate with a surface-based computer, and 3) prototype wheel shapes that can handle a variety of volcanic rock textures. The robot's mechanical parts were built using 3d printing, milling, casting and laser cutting techniques, and the electronics were assembled from off the shelf components. The testing phase took place at Mauna Ulu, Kīlauea, Hawai'i, from May 5 - 9, 2014. Many valuable design lessons were learned during the week, and the first ever 3D map from inside a volcanic fissure were successfully collected. Three vents had between 25% and 95% of their internal surfaces imaged. A fourth location, a non-eruptive crack (possibly a fault line) had two transects imaging the textures of the walls with depth to compare to the fissure vents. The vent surface irregularity documented by Parcheta et al., (accepted) continues with depth into the fissure; depths are variable depending on the amount of talus filling them. We will show and discuss data from the main field vent location, and movies of descents in to the other vents.

Traumatic superior orbital fissure syndrome: assessment of cranial nerve recovery in 33 cases.

PubMed

Chen, Chien-Tzung; Wang, Theresa Y; Tsay, Pei-Kwei; Huang, Faye; Lai, Jui-Pin; Chen, Yu-Ray

2010-07-01

Superior orbital fissure syndrome is a rare complication that occurs in association with craniofacial trauma. The characteristics of superior orbital fissure syndrome are attributable to a constellation of cranial nerve III, IV, and VI palsies. This is the largest series describing traumatic superior orbital fissure syndrome that assesses the recovery of individual cranial nerve function after treatment. In a review from 1988 to 2002, 33 patients with superior orbital fissure syndrome were identified from 11,284 patients (0.3 percent) with skull and facial fractures. Severity of cranial nerve injury and functional recovery were evaluated by extraocular muscle movement. Patients were evaluated on average 6 days after initial injury, and average follow-up was 11.8 months. There were 23 male patients. The average age was 31 years. The major mechanism of injury was motorcycle accident (67 percent). Twenty-two received conservative treatment, five were treated with steroids, and six patients underwent surgical decompression of the superior orbital fissure. After initial injury, cranial nerve VI suffered the most damage, whereas cranial nerve IV sustained the least. In the first 3 months, recovery was greatest in cranial nerve VI. At 9 months, function was lowest in cranial nerve VI and highest in cranial nerve IV. Eight patients (24 percent) had complete recovery of all cranial nerves. Functional recovery of all cranial nerves reached a plateau at 6 months after trauma. Cranial nerve IV suffered the least injury, whereas cranial nerve VI experienced the most neurologic deficits. Cranial nerve palsies improved to their final recovery endpoints by 6 months. Surgical decompression is considered when there is evidence of bony compression of the superior orbital fissure.

Efficacy of nitroglycerine ointment in the treatment of pediatric anal fissure.

PubMed

Joda, Ali E; Al-Mayoof, Ali F

2017-11-01

Anal fissure is the most common anal disease in children. In the past few decades, the understanding of its pathophysiology has led to a progressive reduction in invasive procedures in favor of conservative treatment based on stool softeners and the relaxation of the anal sphincter. This randomized controlled study assessed the safety and efficacy of nitroglycerine (NTG) ointment in the treatment of pediatric anal fissure, which had not yet been proved. An unequal randomized controlled study included 105 pediatric patients with anal fissure who had presented to the private and outpatient clinics of the Central Teaching Hospital of Pediatrics during the period from February 2015 to May 2016. The control group consisted of 70 patients. Both groups were treated with classical conservative therapy of sitz bath, stool softener, and local anesthetic. In the second group, chemical sphincterotomy with 0.2% NTG ointment was used in 35 patients, and was applied at the anal canal twice daily for 8weeks. The primary outcomes of symptomatic improvement and healed fissure, as well as side effects, were analyzed. The average age of patients was 2years (range, 4months to 5years). Patients in the NTG group had 77% symptomatic relief and 60% healed fissure compared to the control group, which had 54% and 32.8% respectively. All were statistically significant. No serious adverse effects were noticed during the treatment period. The use of 0.2% NTG ointment is an effective therapy for anal fissure in children in terms of good healing rate and rapid symptom relief, but it has the drawback of a long treatment period, making patient compliance more difficult, in addition to the problems of tolerance and recurrence. Prospective randomized controlled study (treatment study). Type 2. Copyright © 2017 Elsevier Inc. All rights reserved.

A robotic approach to mapping post-eruptive volcanic fissure conduits

NASA Astrophysics Data System (ADS)

Parcheta, Carolyn E.; Pavlov, Catherine A.; Wiltsie, Nicholas; Carpenter, Kalind C.; Nash, Jeremy; Parness, Aaron; Mitchell, Karl L.

2016-06-01

VolcanoBot was developed to map volcanic vents and their underlying conduit systems, which are rarely preserved and generally inaccessible to human exploration. It uses a PrimeSense Carmine 1.09 sensor for mapping and carries an IR temperature sensor, analog distance sensor, and an inertial measurement unit (IMU) inside a protective shell. The first field test succeeded in collecting valuable scientific data but revealed several needed improvements, including more rugged cable connections and mechanical couplers, increased ground clearance, and higher-torque motors for uphill mobility. The second field test significantly improved on all of these aspects but it traded electrical ruggedness for reduced data collection speed. Data collected by the VolcanoBots, while intermittent, yield the first insights into the cm-scale geometry of volcanic fissures at depths of up to 25 m. VolcanoBot was deployed at the 1969 Mauna Ulu fissure system on Kīlauea volcano in Hawai'i. It collected first-of-its-kind data from inside the fissure system. We hypothesized that 1) fissure sinuosity should decrease with depth, 2) irregularity should be persistent with depth, 3) any blockages in the conduit should occur at the narrowest points, and 4) the fissure should narrow with depth until it is too narrow for VolcanoBot to pass or is plugged with solidified lava. Our field campaigns did not span enough lateral or vertical area to test sinuosity. The preliminary data indicate that 1) there were many irregularities along fissures at depth, 2) blockages occurred, but not at obviously narrow locations, and 3) the conduit width remained a consistent 0.4-0.5 m for most of the upper 10 m that we analyzed.

Fissurectomy Combined with High-Dose Botulinum Toxin Is a Safe and Effective Treatment for Chronic Anal Fissure and a Promising Alternative to Surgical Sphincterotomy.

PubMed

Barnes, Thomas G; Zafrani, Zakhi; Abdelrazeq, Ayman S

2015-10-01

There is paucity of data on the long-term outcome of the combination of fissurectomy and botulinum toxin A injection for the management of chronic anal fissure. The aim of this study is to assess the safety, efficacy, and long-term outcome of the combination of fissurectomy and botulinum toxin A injection. This is a nonrandomized prospective cohort study. This study was conducted at a district general hospital in the United Kingdom. The cohort included all patients treated with fissurectomy and botulinum toxin A for chronic anal fissure between September 2008 and March 2012. The patients were treated with a combination of fissurectomy and botulinum toxin A injection. Symptomatic relief, fissure healing, complications, recurrence, and the need for further surgical intervention. One hundred and two patients received fissurectomy and botulinum toxin A injection for chronic anal fissure. At 12-week follow-up, 68 patients had resolution of symptoms and complete healing of chronic anal fissure, 29 patients had improvement of symptoms but incomplete healing and had further topical or botulinum toxin A treatment with subsequent complete healing. Ninety-five patients (93%) reported no postoperative complications. Seven patients reported a degree of incontinence in the immediate postoperative period. All reported normal continence at12-week follow-up. No local complications were observed or reported. At the mean follow-up of 33 months, there was no evidence of recurrence. Twelve-month follow-up was conducted via telephone interview only. This study is nonrandomized and did not examine the dose response of Botulinum Toxin A. Fissurectomy combined with high-dose botulinum toxin A is a safe, effective, and durable option for the management of chronic anal fissure and a promising alternative to surgical sphincterotomy.

Cyp1b1 Regulates Ocular Fissure Closure Through a Retinoic Acid–Independent Pathway

PubMed Central

Williams, Antionette L.; Eason, Jessica; Chawla, Bahaar; Bohnsack, Brenda L.

2017-01-01

Purpose Mutations in the CYP1B1 gene are the most commonly identified genetic causes of primary infantile-onset glaucoma. Despite this disease association, the role of CYP1B1 in eye development and its in vivo substrate remain unknown. In the present study, we used zebrafish to elucidate the mechanism by which cyp1b1 regulates eye development. Methods Zebrafish eye and neural crest development were analyzed using live imaging of transgenic zebrafish embryos, in situ hybridization, immunostaining, TUNEL assay, and methylacrylate sections. Cyp1b1 and retinoic acid (RA) levels were genetically (morpholino oligonucleotide antisense and mRNA) and pharmacologically manipulated to examine gene function. Results Using zebrafish, we observed that cyp1b1 was expressed in a specific spatiotemporal pattern in the ocular fissures of the developing zebrafish retina and regulated fissure patency. Decreased Cyp1b1 resulted in the premature breakdown of laminin in the ventral fissure and altered subsequent neural crest migration into the anterior segment. In contrast, cyp1b1 overexpression inhibited cell survival in the ventral ocular fissure and prevented fissure closure via an RA-independent pathway. Cyp1b1 overexpression also inhibited the ocular expression of vsx2, pax6a, and pax6b and increased the extraocular expression of shha. Importantly, embryos injected with human wild-type but not mutant CYP1B1 mRNA also showed colobomas, demonstrating the evolutionary and functional conservation of gene function between species. Conclusions Cyp1b1 regulation of ocular fissure closure indirectly affects neural crest migration and development through an RA-independent pathway. These studies provide insight into the role of Cyp1b1 in eye development and further elucidate the pathogenesis of primary infantile-onset glaucoma. PMID:28192799

Conditions of Fissuring in a Pumped-Faulted Aquifer System

NASA Astrophysics Data System (ADS)

Hernandez-Marin, M.; Burbey, T. J.

2007-12-01

Earth fissuring associated with subsidence from groundwater pumping is problematic in many arid-zone heavily pumped basins such as Las Vegas Valley. Long-term pumping at rates considerably greater than the natural recharge rate has stressed the heterogeneous aquifer system resulting in a complex stress-strain regime. A rigorous artificial recharge program coupled with increased surface-water importation has allowed water levels to appreciably recover, which has led to surface rebound in some localities. Nonetheless, new fissures continue to appear, particularly near basin-fill faults that behave as barriers to subsidence bowls. The purpose of this research is to develop a series of computational models to better understand the influence that structure (faults), pumping, and hydrostratigraphy has in the generation and propagation of fissures. The hydrostratigraphy of Las Vegas Valley consists of aquifers, aquitards and a relatively dry vadoze zone that may be as thick as 100m in much of the valley. Quaternary faults are typically depicted as scarps resulting from pre- pumping extensional tectonic events and are probably not responsible for the observed strain. The models developed to simulate the stress-strain and deformation processes in a faulted pumped aquifer-aquitard system of Las Vegas use the ABAQUS CAE (Complete ABAQUS Environment) software system. ABAQUS is a sophisticated engineering industry finite-element modeling package capable of simulating the complex fault- fissure system described here. A brittle failure criteria based on the tensile strength of the materials and the acting stresses (from previous models) are being used to understand how and where fissures are likely to form. , Hypothetical simulations include the role that faults and the vadose zone may play in fissure formation

Three-Dimensional Numerical Simulation on Triaxial Failure Mechanical Behavior of Rock-Like Specimen Containing Two Unparallel Fissures

NASA Astrophysics Data System (ADS)

Huang, Yan-Hua; Yang, Sheng-Qi; Zhao, Jian

2016-12-01

A three-dimensional particle flow code (PFC3D) was used for a systematic numerical simulation of the strength failure and cracking behavior of rock-like material specimens containing two unparallel fissures under conventional triaxial compression. The micro-parameters of the parallel bond model were first calibrated using the laboratory results of intact specimens and then validated from the experimental results of pre-fissured specimens under triaxial compression. Numerically simulated stress-strain curves, strength and deformation parameters and macro-failure modes of pre-fissured specimens were all in good agreement with the experimental results. The relationship between stress and the micro-crack numbers was summarized. Crack initiation, propagation and coalescence process of pre-fissured specimens were analyzed in detail. Finally, horizontal and vertical cross sections of numerical specimens were derived from PFC3D. A detailed analysis to reveal the internal damage behavior of rock under triaxial compression was carried out. The experimental and simulated results are expected to improve the understanding of the strength failure and cracking behavior of fractured rock under triaxial compression.

Tracer Movement in a Single Fissure in Granitic Rock: Some Experimental Results and Their Interpretation

NASA Astrophysics Data System (ADS)

Neretnieks, Ivars; Eriksen, Tryggve; TäHtinen, PäIvi

1982-08-01

Radionuclide migration was studied in a natural fissure in a granite core. The fissure was oriented parallel to the axis in a cylindrical core 30 cm long and 20 cm in diameter. The traced solution was injected at one end of the core and collected at the other. Breakthrough curves were obtained for the nonsorbing tracers, tritiated water, and a large-molecular-weight lignosulphonate molecule and for the sorbing tracers, cesium and strontium. From the breakthrough curves for the nonsorbing tracers it could be concluded that channeling occurs in the single fissure. A `dispersion' model based on channeling is presented. The results from the sorbing tracers indicate that there is substantial diffusion into and sorption in the rock matrix. Sorption on the surface of the fissure also accounts for a part of the retardation effect of the sorbing species. A model which includes the mechanisms of channeling, surface sorption, matrix diffusion, and matrix sorption is presented. The experimental breakthrough curves can be fitted fairly well by this model by use of independently obtained data on diffusivities and matrix sorption.

Glaser Fissure, Huguier Canal, and Civinini Canal: A Confused Eponymical Imbroglio.

PubMed

Mudry, Albert

2015-07-01

Huguier canal or Civinini canal is a canaliculus in the Glaser fissure allowing the exit of the chorda tympani from the tympanic cavity. The aim of this study is to try to put some order in the origins and relations of these different eponyms, and to evaluate their pertinence in the actual anatomical terminology. This study demonstrates that Huguier and Civinini are not the first to describe this canal in the 1830s. Furthermore, it confirms that Glaser does not describe the related fissure in 1680. In conclusion, Glaser, Civinini, and Huguier no longer have a place in the actual anatomical nomenclature of the fine details of the temporal bone. To avoid confusion and errors, they must be replaced by anterior canaliculus for the chorda tympani and petrotympanic fissure.

Geometry of the September 1971 eruptive fissure at Kilauea volcano, Hawaii

USGS Publications Warehouse

Dvorak, J.J.

1990-01-01

A three-dimensional model has been used to estimate the location and dimensions of the eruptive fissure for the 24-29 September 1971 eruption along the southwest rift zone of Kilauea volcano, Hawaii. The model is an inclined rectangular sheet embedded in an elastic half-space with constant displacement on the plane of the sheet. The set of "best" model parameters suggests that the sheet is vertical, extends from a depth of about 2 km to the surface, and has a length of about 14 km. Because this sheet intersects the surface where eruptive vents and extensive ground cracking formed during the eruption, this sheet probably represents the conduit for erupted lava. The amount of displacement perpendicular to the sheet is about 1.9 m, in the middle range of values measured for the amount of opening across the September 1971 eruptive fissure. The thickness of the eruptive fissure associated with the January 1983 east rift zone eruption was determined in an earlier paper to be 3.6 m, about twice the thickness determined here for the September 1971 eruption. Because the lengths (12 km for 1983 and 14 km for 1971) and heights (about 2 km) of the sheet models derived for the January 1983 and September 1971 rift zone eruptions are nearly identical, the greater thickness for the January 1983 eruptive fissure implies that the magma pressure was about a factor of two greater to form the January 1983 eruptive fissure. Because the September 1971 and January 1983 eruptive fissures extent to depths of only a few kilometers, the region of greatest compressive stress produced along the volcano's flank by either of these eruptive fissures would also be within a few kilometers of the surface. Previous work has shown that rift eruptions and intrusions contribute to the buildup of compressive stress along Kilauea's south flank and that this buildup is released by increased seismicity along the south flank. Because south flank earthquakes occur at significantly greater depths, i.e., from 5 to 13 km, than the vertical extent of the 1971 and 1983 eruptiv fissures, the depth of emplacement of these eruptive fissures cannot be the main factor in controlling the hypocentral depths of south flank earthquakes. Two possible explanations for the occurrence of south flank earthquakes in the depth range of 5-13 km are (1) a deeper pressure source, possibly related to deeper magma storage within the rift zone, and (2) a lowstrength region located between 5 and 13 km beneath Kilauea's south flank, possibly at the interface between oceanic sediments and the base of the Hawaiian volcanics. ?? 1990 Springer-Verlag.

Deformation during the 1975-84 Krafla rifting crisis, NE Iceland, measured by optical image correlation

NASA Astrophysics Data System (ADS)

Hollingsworth, J.; Leprince, S.; Avouac, J.; Ayoub, F.

2011-12-01

In this study we combine results from optical image correlation of SPOT, KH-9 spy satellite and aerial photos, EDM data and high resolution topographic data to better constrain the 3D deformation associated with the 1975-84 Krafla rifting crisis, NE Iceland. Inversion of the various geodetic datasets yields new volumes for the amount of material injected into the crust during this rifting crisis. Correlation of aerial photos from 1957 and 1990 for the middle section of the 2 km-wide Krafla fissure swarm, along with DEM differencing of their respective 1957 and 1990 DEM's (extracted using photogrammetric techniques), provides constraints on the full 3D displacement field spanning the entire rifting period. Elastic dislocation modeling of this displacement data is then used to determine the geometry of faulting and diking in the crust. In contrast to leveling data from the northern end of the fissure swarm (Rubin, et al., 1988), we find that dikes do not extend into the upper 1-2 km, where extension is accommodated primarily by faulting in the fissure swarm. Dislocation modeling of a 4 m-wide dike injected between 2 km and 6 km in the crust produces a maximum surface strain which reaches the elastic yield limit for rock (derived from laboratory experiments of deformed granite) at two points spanning a 2 km-wide zone above the dike, and which corresponds with the location of the major rift-bounding faults of the Krafla fissure swarm. If dikes extend nearer to the surface, the predicted fissure zone width would be correspondingly smaller (consistent with the southern-end of the fissure swarm), while deeper diking produces a wider fissure swarm (consistent with the northern-end of the fissure swarm). The apparent northward increase in depth of diking is consistent with the flexural effects of rift-margin topography (Behn, et al., 2006); increased flexure in the south, where the Krafla caldera is located, results in the promotion of shallow diking, where as subdued topography in the north promotes deeper diking. Correlation of aerial photos between 1957 and 1976 (during the early stages of the rifting crisis) indicate 2 m extension, which is localized on faults along the northern end of the fissure swarm. No fault slip occurs in the central section of the fissure swarm during the same period, suggesting extension in the north during the early stages of rifting may result from dike injections sourced from the north (possibly offshore), rather than the Krafla caldera to the south. A similar variation in magmatic source region was also observed during the 2005-2009 Afar rifting crisis in East Africa.

Anal fissure - slideshow

MedlinePlus

... this page: //medlineplus.gov/ency/presentations/100154.htm Anal fissure - series—Normal anatomy To use the sharing ... rectum through which passes stool during defecation. The anal sphincter is a critical mechanism for control of ...

Sylvian fissure lipoma with angiomatous component and associated brain malformation: A case report.

PubMed

Thakur, Shruti; Sood, Ram Gopal; Jhobta, Anupam; Makhaik, Sushma; Thakur, Charusmita

2013-01-01

Intracranial lipomas are congenital malformations. These uncommon lesions have an incidence of 0.1 to 1.7% of all intracranial tumors. Most cases are located at midline and 5% are along the sylvian fissures. If symptomatic, seizures are the most common symptom. These tumors are slow growing and have favorable outcome. We report a case of a 25-year-old man whose CT and MRI revealed a lesion in right sylvian fissure suggesting a lipoma with abnormal vasculature and overlying cortical dysplasia.

Off-fault ground ruptures in the Santa Cruz Mountains, California: Ridge-top spreading versus tectonic extension during the 1989 Loma Prieta earthquake

USGS Publications Warehouse

Ponti, Daniel J.; Wells, Ray E.

1991-01-01

The Ms 7.1 Loma Prieta earthquake of 18 October 1989 produced abundant ground ruptures in an 8 by 4 km area along Summit Road and Skyland Ridge in the Santa Cruz Mountains. Predominantly extensional fissures formed a left-stepping, crudely en echelon pattern along ridges of the hanging-wall block southwest of the San Andreas fault, about 12 km northwest of the epicenter. The fissures are subparallel to the San Andreas fault and appear to be controlled by bedding planes, faults, joints, and other weak zones in the underlying Tertiary sedimentary strata of the hanging-wall block. The pattern of extensional fissures is generally consistent with tectonic extension across the crest of the uplifted hanging-wall block. Also, many displacements in Laurel Creek canyon and along the San Andreas and Sargent faults are consistent with right-lateral reverse faulting inferred for the mainshock. Additional small tensile failures along the axis of the Laurel anticline may reflect growth of the fold during deep-seated compression. However, the larger ridge-top fissures commonly have displacements that are parallel to the north-northeast regional slope directions and appear inconsistent with east-northeast extension expected from this earthquake. Measured cumulative displacements across the ridge crests are at least 35 times larger than that predicted by the geodetically determined surface deformation. These fissures also occur in association with ubiquitous landslide complexes that were reactivated by the earthquake to produce the largest concentration of co-seismic slope failures in the epicentral region. The anomalously large displacements and the apparent slope control of the geometry and displacement of many co-seismic surface ruptures lead us to conclude that gravity is an important driving force in the formation of the ridge-top fissures. Shaking-induced gravitational spreading of ridges and downslope movement may account for 90¿ or more of the observed displacements on the linear fissures. Similar fissures occurred in the same area and elsewhere near the San Andreas fault during the predominantly right-lateral 1906 San Francisco earthquake and suggest that the Loma Prieta ground ruptures may, in large part, be independent of fault kinematics.

Pulmonary lobe segmentation based on ridge surface sampling and shape model fitting

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

Ross, James C., E-mail: jross@bwh.harvard.edu; Surgical Planning Lab, Brigham and Women's Hospital, Boston, Massachusetts 02215; Laboratory of Mathematics in Imaging, Brigham and Women's Hospital, Boston, Massachusetts 02126

2013-12-15

Purpose: Performing lobe-based quantitative analysis of the lung in computed tomography (CT) scans can assist in efforts to better characterize complex diseases such as chronic obstructive pulmonary disease (COPD). While airways and vessels can help to indicate the location of lobe boundaries, segmentations of these structures are not always available, so methods to define the lobes in the absence of these structures are desirable. Methods: The authors present a fully automatic lung lobe segmentation algorithm that is effective in volumetric inspiratory and expiratory computed tomography (CT) datasets. The authors rely on ridge surface image features indicating fissure locations and amore » novel approach to modeling shape variation in the surfaces defining the lobe boundaries. The authors employ a particle system that efficiently samples ridge surfaces in the image domain and provides a set of candidate fissure locations based on the Hessian matrix. Following this, lobe boundary shape models generated from principal component analysis (PCA) are fit to the particles data to discriminate between fissure and nonfissure candidates. The resulting set of particle points are used to fit thin plate spline (TPS) interpolating surfaces to form the final boundaries between the lung lobes. Results: The authors tested algorithm performance on 50 inspiratory and 50 expiratory CT scans taken from the COPDGene study. Results indicate that the authors' algorithm performs comparably to pulmonologist-generated lung lobe segmentations and can produce good results in cases with accessory fissures, incomplete fissures, advanced emphysema, and low dose acquisition protocols. Dice scores indicate that only 29 out of 500 (5.85%) lobes showed Dice scores lower than 0.9. Two different approaches for evaluating lobe boundary surface discrepancies were applied and indicate that algorithm boundary identification is most accurate in the vicinity of fissures detectable on CT. Conclusions: The proposed algorithm is effective for lung lobe segmentation in absence of auxiliary structures such as vessels and airways. The most challenging cases are those with mostly incomplete, absent, or near-absent fissures and in cases with poorly revealed fissures due to high image noise. However, the authors observe good performance even in the majority of these cases.« less

Shift from magmatic to phreatomagmatic explosion controlled by the evolution of lateral fissure eruption in Suoana Crater, Miyakejima

NASA Astrophysics Data System (ADS)

Geshi, Nobuo; Nemeth, Karoly; Noguchi, Rina; Oikawa, Teruki

2016-04-01

Combined analysis of the proximal deposit and exposed feeder-diatreme structure of the Suoana Crater of Miyakejima reveals the process of magma-water interaction controlled by the evolution of lateral fissure eruption in a stratovolcanic edifice. The Suoana Crater, an oval maar with 400 x 300 m across is one of the craters of the Suoana-Kazahaya crater chain which is formed during a fissure eruption in the 7th Century. The eruption fissure extends ~3 km from the summit area (~700 m asl) to the lower-flank area (~200m asl). The eruption fissure consists of upper maar-chain (>450 m asl) and lower scora-cone chain. As the wall of the 2000 AD caldera truncated at near the center of the Suoana Crater, the vertical section of the feeder dike - diatreme - maar system of the Suoana Crater is exposed in the caldera wall (Geshi et al., 2011). The ejected materials from the Suoana crater indicate the transition of eruption style from magmatic to phreatomagmatic. The juvenile clasts in the lower half of the deposit exhibit spatter-like shape, indicating the typical deposit from a vigorous fire fountain. Contrary, the juvenile clasts in the upper half are less vesiculated and exhibit cauliflower-shape, indicating the typical phreatomagmatic activity. This transition indicates that the magma-water interaction started at the middle of the eruption. Judging from the ratio of the thickness of the lower and upper parts, the contrast of the content of juvenile clasts, and bulk density of the deposit, the total ejected volume of magma is larger in the lower part compare to the upper part. The transition from magmatic to phreatomagmatic occurred only in the upper half of the eruption fissure, including the Suoana crater, whereas the lower half of the fissure continued dry magmatic eruption throughout their activity. The limited distribution of phreatomagmatic activity can be resulted by the magma extraction from the upper feeder dike system to the lower eruption fissure as it contributed to the general drop of magmatic pressure in the upper section of the fissure-fed conduit. The cross section of the Suoana diatreme indicates that the phreatomagmatic explosion occurred ~260 m below the original ground surface, corresponding to ~400 m above the present sea level. This elevation is clearly higher than that of the lower part of the eruption fissure which reached to the point ~ 200 m above sea level. The drop of magma flux and the general gravitational instability of the conduit resulted that ground water was able to access the still hot feeder dikes and initiate phreatomagmatic explosive eruptions (e.g., Geshi and Neri, 2014). The existence of buried summit caldera that can host large quantity of groundwater also contributes the limited distribution of phreatomagmatic activity in the summit area. We propose that this seemingly reversal trend from early magmatic to later phreatomagmatic explosive eruption style in top of large mafic caldera volcanoes in fissure fed volcanic islands is probably a far more common eruption mechanism and hence it needs to be considered in volcanic hazard scenario descriptions.

"Who is talking to me?" - Self-other attribution of auditory hallucinations and sulcation of the right temporoparietal junction.

PubMed

Plaze, Marion; Mangin, Jean-François; Paillère-Martinot, Marie-Laure; Artiges, Eric; Olié, Jean-Pierre; Krebs, Marie-Odile; Gaillard, Raphaël; Martinot, Jean-Luc; Cachia, Arnaud

2015-12-01

Brain imaging research in schizophrenia has provided a better understanding of the neural basis of auditory hallucinations (AH). Recently, renewed interest in the phenomenology of AH raised questions related to their neural substrates. Hence, the neural basis of AH self/other attribution have yet to be investigated as beliefs regarding the origin of the voices is a cardinal feature of AH phenomenology. As the right temporoparietal junction (TPJ) and the inferior parietal lobule (IPL) play a key role in disentangling the origin of sensory events and in self/other distinction, we tested the hypothesis that the morphology of the IPL/TPJ area may be involved in AH self/other attribution. Magnetic resonance images of 39 right-handed patients with persistent auditory hallucinations and 19 healthy subjects were analyzed with sulcus-based morphometry. AH self-other attribution were found to be associated with the sulcal pattern of the posterior part of the Sylvian fissure, encompassing the IPL/TPJ area. The preference for the attribution of AH to self or to others could be associated with early neurodevelopmental events as the sulcal pattern is determined during fetal life and is stable after birth. Our study also raises basic cognitive questions regarding self-consciousness and suggest that impairments at a pre-reflexive level, leading to hearing his/her thoughts as voices ('I' level or feeling of agency), and a reflexive level leading to attribution belief ('Me' level or judgment of agency) are likely involved in AH. Copyright © 2015 Elsevier B.V. All rights reserved.

Calcified gallstone fissures: the reversed Mercedes Benz sign.

PubMed

Strijk, S P

1987-01-01

This article describes the occurrence of an unusual radiating pattern of calcification in the center of large radiolucent gallstones. The radiographic findings are attributed to calcium deposition within the fissures of biliary calculi.

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant and... depressions (faults in the enamel) in the biting surfaces of teeth to prevent cavities. (b) Classification...

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2013 CFR

2013-04-01

... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant and... depressions (faults in the enamel) in the biting surfaces of teeth to prevent cavities. (b) Classification...

The economics of pit and fissure sealants in preventive dentistry: a review.

PubMed

Kitchens, Dinah H

2005-08-15

Oral diseases are progressive, cumulative, and become more intricate to treat with advancement. While dental caries is an infectious transmissible disease with children being at the highest risk, primary prevention can reduce this risk. Primary prevention in dentistry is usually considered to be community fluoridated water supplies, professional fluoride treatments, and pit and fissure sealants. While community fluoridated water supplies have been proven to be cost-effective, the cost-effectiveness of pit and fissure sealants has primarily been studied in school-based programs of children from low socio-economic backgrounds. Dental sealant programs are just one way to help increase primary prevention in the oral health disparities of children. The purpose of this paper is to review the literature regarding the cost-effectiveness of pit and fissure sealants as a preventive strategy in preventive dentistry.

Comparative study of Ksharasutra suturing and Lord's anal dilatation in the management of Parikartika (chronic fissure-in-ano).

PubMed

Dudhamal, Tukaram S; Baghel, Madhav Singh; Bhuyan, Chaturbhuja; Gupta, Sanjay Kumar

2014-04-01

Parikartika resembles fissure-in-ano which is very common among all ano-rectal disorders. In Ayurvedic texts, Parikartika is described as a complication of Vamana and Virechana as well as complication of Atisara. Ksharasutra was proved successful in the management of fistula-in-ano, piles, and there is a need to try its efficacy in fissure-in-ano. To evaluate the role of Ksharasutra suturing (KSS) in fissure bed in chronic fissure-in-ano. Total 100 patients of chronic fissure-in-ano were selected and randomly divided into two groups (50 in each group). In group-A, patients were undergone by KSS; while in patients of Group-B Lord's anal dilatation followed by KSS was done under spinal anesthesia. The KSS was done once and after slough out of Ksharasutra, the wound was treated for 4 weeks and assessment of the result was done on the basis of gradation adopted. The pain relief on 14(th) day in Group-A was 86% while in Group-B 100% was observed. As on 7(th) day in Group-A, oozing was stopped in 68% patients, while in Group-B, oozing was stopped in 82% patients. On 21(st) day, Group-B showed more healing (85%) as compared to Group-A (69%). In this study 68% of patients were cured. In Group-B (KSS with Lord's anal dilatation) patients were cured early as compared to patients of Group-A (KSS alone).

Pumping-induced stress and strain in aquifer systems in Wuxi, China

NASA Astrophysics Data System (ADS)

Zhang, Yun; Yu, Jun; Gong, Xulong; Wu, Jichun; Wang, Zhecheng

2018-05-01

Excessive groundwater withdrawal from an aquifer system leads to three-dimensional displacement, causing changes in the states of stress and strain. Often, land subsidence and sometimes earth fissures ensue. Field investigation indicates that land subsidence and earth fissures in Wuxi, a city in eastern China, are mainly due to excessive groundwater withdrawal, and that they are temporally and spatially related to groundwater pumping. Groundwater withdrawal may cause tensile strain to develop in aquifer systems, but tensile strain does not definitely mean tensile stress. Where earth fissures are concerned, the stress state should be adopted in numerical simulations instead of the strain state and displacement. The numerical simulation undertaken for the Wuxi area shows that the zone of tensile strain occupies a large area on the ground surface; nevertheless, the zone of tensile stress is very limited. The zone of tensile stress often occurs near the ground surface, beneath which the depth to the bedrock surface is relatively small and has considerable variability. Earth fissures often initiate near the ground surface where tensile stress occurs. Tensile stress and earth fissures rarely develop at the centers of land subsidence bowls, where compressive stress is dominant.

A comparison between three different pit and fissure sealants with regard to marginal integrity.

PubMed

Fernandes, Kristlee Sabrin; Chalakkal, Paul; de Ataide, Ida de Noronha; Pavaskar, Rajdeep; Fernandes, Precylia Philo; Soni, Harleen

2012-04-01

THE AIM OF THIS STUDY IS TO COMPARE THE OCCURRENCE OF ENAMEL FRACTURES, SEALANT FRACTURES AND MARGINAL FISSURES AFTER PLACEMENT OF THREE SEALANTS: Helioseal F, Conseal F and Clinpro. Thirty individuals between 13 and 15 years of age, diagnosed with pit and fissure caries by visual and DIAGNOdent examination, were chosen for sealant placement on their mandibular molars. The sealants were placed at random, after which, impressions were made with polyvinyl siloxane and casts were fabricated. Dies were prepared, each of which were sputter coated with gold in order to be examined under a scanning electron microscope. The following morphologies were analyzed from dies from each of the sealant groups: Continuous margins, sealant fractures, marginal fissures and enamel fractures. After six months, they were recalled for impression making. Dies were prepared and microscopically analyzed as mentioned. Based on the time of evaluation, there were two groups: Initial group (soon after placement) and final group (after six months). Statistical analysis was done using the paired 't' test and One-way analysis of variance (ANOVA). Clinpro had the greatest fracture resistance, followed by Conseal F and Helioseal F. The occurrence of marginal fissure was found to be least with Clinpro.

[Diagnosis and surgical treatment of intraparenchymal sylvian fissure meningioma].

PubMed

Zheng, Jian; Wang, Shuo; Zhao, Ji-Zong; Cao, Yong

2009-09-08

To describe the characteristics of patients diagnosed with intraparenchymal sylvian meningioma at our department. A retrospective review was performed over 5 patients with intraparenchymal sylvian fissure meningioma confirmed by histopathology and receiving treatment at our department during January 1997 to September 2008. The mean age was 19.4 years old and there were 3 males and 2 females. On CT scanning, intraparenchymal sylvian meningioma was iso- or slightly hyper-dense masses. On MR imaging, tumors showed iso- or hypo- intense signal on T1WI and hyperintense signal on T2WI. After contrast enhancement, T1-weighted images revealed well-demarcated enhancing masses and intimately associated with the middle cerebral artery and its branches in the sylvian fissure. All the patients underwent craniotomy. As a rare disease with radiographic characteristics similar to those of general meningiomas, intraparenchymal sylvian fissure meningioma does not adhere to the dura matter but adhere to or even encase the middle cerebral artery and its branches in the sylvian fissure. All of the above have differential values. During the surgical procedures, a proper handling of tumor and encompassed main trunk of middle cerebral artery and its branches is crucial to patient prognosis.

The effect of Saqez (Pistacia atlantica) ointment on the treatment of nipple fissure and nipple pain in breastfeeding women

PubMed Central

As’adi, Nayereh; Kariman, Nourossadat; Mojab, Faraz; Pourhoseingholi, Mohammad Amin

2017-01-01

Background Nipple fissure is a common problem in breastfeeding women, and the main reason for the early discontinuation of breastfeeding. Objective To determine the effect of Saqez (Pistacia atlantica) ointment on the treatment of nipple fissure and nipple pain in breastfeeding women. Methods This randomized clinical trial was conducted on 100 subjects admitted to the health centers in Tehran, Iran from mid-July to mid-November 2015. The subjects were randomly divided into two equal groups of 50 for the Saqez ointment group and the control group. The subjects were divided into the two groups through random allocation in Excel. The subjects were monitored on day 1, 3 and 7. Data were analyzed in SAS using the Cumulative Logit model and in SPSS-21 using Mann-Whitney, independent-samples t-test, the Chi square and Fisher’s exact test. Results No significant differences were observed between the two groups in terms of their demographic and fertility characteristics. The Cumulative Logit model showed that high levels of nipple fissure and pain were significantly less frequent in the Saqez group compared to the control group (p<0.001). There was about 83% reduction in the severity of fissure and 85 %in the severity of pain in the Saqez group compared to the control group (p<0.001). Conclusion Saqez ointment is more effective in the treatment of nipple fissures and pain than breast milk. As this study was done for the first time, judgment about the conclusive efficacy of Saqez ointment on the nipple fissure, needs further similar studies. Trial registration The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT2015080723535N1. Funding The authors received no financial support for the research, authorship, and/or publication of this article. PMID:28979728

Enhancing caries resistance in occlusal fissures with a short-pulsed CO2 9.6-μm laser: an in vitro pH-cycling study, preliminary results

NASA Astrophysics Data System (ADS)

Charland, Daniel; Fulton, Crystal; Rechmann, Beate; Hewko, Mark; Featherstone, John; Choo-Smith, Lin-P'ing; Rechmann, Peter

2011-03-01

Treatment of occlusal surfaces with a short-pulsed CO2 9.6 μm wavelength laser has previously been proposed as a method for caries prevention. A sample of 20 extracted human molars were measured before and after demineralizationremineralization pH-cycling with ICDAS II visual inspection, DIAGNOdent, quantitative light-induced fluorescence (QLF), SoproLife in daylight and blue light-induced fluorescence mode, optical coherence tomography (OCT) and polarized Raman spectroscopy (PRS). Per tooth, one fissure was subjected to laser treatment using a short-pulsed CO2 laser at 9.6 μm wavelength with a fluence of 3.5 J/cm2, 20 Hz pulse repetition rate, 20 μs pulse duration, angulated handpiece, and focus diameter of 600 μm, while the other fissure was left untreated as control. The teeth were subjected to a demineralization-remineralization pH-cycling for 9 days. Cross-sectional micro-hardness testing was done as a gold standard to compare results with findings from the other detection methods used. Due to the small sample size reported, the trend observed was that laser treated fissures demonstrated a smaller relative mineral loss ▵Z than the controls. QLF findings followed a similar trend. Using a rotary catheter probe, OCT measurements were acquired from the various fissures to generate circularly mapped OCT depth images. PRS measurements of parallel- and cross-polarized spectra were acquired with a Raman microscope system. Preliminary OCT images showed differences in the initial air-tooth interface, with PRS results indicating a change in the surface property along with biochemical alterations after pH-cycling. Following pH-cycling, an increase in the OCT subsurface light backscattering intensity in the control fissures was observed compared to the laser test fissures. Porphyrin based fluorescence methods like DIAGNOdent and SoproLife, respectively demonstrated only additional light scattering due to the demineralization process.

Medical and surgical treatment of haemorrhoids and anal fissure in Crohn’s disease: a critical appraisal

PubMed Central

2013-01-01

Background The principle to avoid surgery for haemorrhoids and/or anal fissure in Crohn’s disease (CD) patients is still currently valid despite advances in medical and surgical treatments. In this study we report our prospectively recorded data on medical and surgical treatment of haemorrhoids and anal fissures in CD patients over a period of 8 years. Methods Clinical data of patients affected by perianal disease were routinely and prospectively inserted in a database between October 2003 and October 2011 at the Department of Surgery, Tor Vergata University Hospital, Rome. We reviewed and divided in two groups records on CD patients treated either medically or surgically according to the diagnosis of haemorrhoids or anal fissures. Moreover, we compared in each group the outcome in patients with prior diagnosis of CD and in patients diagnosed with CD only after perianal main treatment. Results Eighty-six CD patients were included in the study; 45 were treated for haemorrhoids and 41 presented with anal fissure. Conservative approach was initially adopted for all patients; in case of medical treatment failure, the presence of stable intestinal disease made them eligible for surgery. Fifteen patients underwent haemorrhoidectomy (open 11; closed 3; stapled 1), and two rubber band ligation. Fourteen patients required surgery for anal fissure (Botox ± fissurectomy 8; LIS 6). In both groups we observed high complication rate, 41.2% for haemorrhoids and 57.1% for anal fissure. Patients who underwent haemorrhoidectomy without certain diagnosis of CD had significantly higher risk of complications. Conclusions Conservative treatment of proctologic diseases in CD patients has been advocated given the high risk of complications and the evidence that spontaneous healing may also occur. From these preliminary results a role of surgery is conceivable in high selected patients, but definitve conclusions can’t be made. Further randomized trials are needed to establish the efficacy of the surgical approach, giving therapeutic recommendations and guidelines. PMID:23496835

Medical and surgical treatment of haemorrhoids and anal fissure in Crohn's disease: a critical appraisal.

PubMed

D'Ugo, Stefano; Franceschilli, Luana; Cadeddu, Federica; Leccesi, Laura; Blanco, Giovanna Del Vecchio; Calabrese, Emma; Milito, Giovanni; Di Lorenzo, Nicola; Gaspari, Achille L; Sileri, Pierpaolo

2013-03-11

The principle to avoid surgery for haemorrhoids and/or anal fissure in Crohn's disease (CD) patients is still currently valid despite advances in medical and surgical treatments. In this study we report our prospectively recorded data on medical and surgical treatment of haemorrhoids and anal fissures in CD patients over a period of 8 years. Clinical data of patients affected by perianal disease were routinely and prospectively inserted in a database between October 2003 and October 2011 at the Department of Surgery, Tor Vergata University Hospital, Rome. We reviewed and divided in two groups records on CD patients treated either medically or surgically according to the diagnosis of haemorrhoids or anal fissures. Moreover, we compared in each group the outcome in patients with prior diagnosis of CD and in patients diagnosed with CD only after perianal main treatment. Eighty-six CD patients were included in the study; 45 were treated for haemorrhoids and 41 presented with anal fissure. Conservative approach was initially adopted for all patients; in case of medical treatment failure, the presence of stable intestinal disease made them eligible for surgery. Fifteen patients underwent haemorrhoidectomy (open 11; closed 3; stapled 1), and two rubber band ligation. Fourteen patients required surgery for anal fissure (Botox ± fissurectomy 8; LIS 6). In both groups we observed high complication rate, 41.2% for haemorrhoids and 57.1% for anal fissure. Patients who underwent haemorrhoidectomy without certain diagnosis of CD had significantly higher risk of complications. Conservative treatment of proctologic diseases in CD patients has been advocated given the high risk of complications and the evidence that spontaneous healing may also occur. From these preliminary results a role of surgery is conceivable in high selected patients, but definitve conclusions can't be made. Further randomized trials are needed to establish the efficacy of the surgical approach, giving therapeutic recommendations and guidelines.

The effect of CT technical factors on quantification of lung fissure integrity

NASA Astrophysics Data System (ADS)

Chong, D.; Brown, M. S.; Ochs, R.; Abtin, F.; Brown, M.; Ordookhani, A.; Shaw, G.; Kim, H. J.; Gjertson, D.; Goldin, J. G.

2009-02-01

A new emphysema treatment uses endobronchial valves to perform lobar volume reduction. The degree of fissure completeness may predict treatment efficacy. This study investigated the behavior of a semiautomated algorithm for quantifying lung fissure integrity in CT with respect to reconstruction kernel and dose. Raw CT data was obtained for six asymptomatic patients from a high-risk population for lung cancer. The patients were scanned on either a Siemens Sensation 16 or 64, using a low-dose protocol of 120 kVp, 25 mAs. Images were reconstructed using kernels ranging from smooth to sharp (B10f, B30f, B50f, B70f). Research software was used to simulate an even lower-dose acquisition of 15 mAs, and images were generated at the same kernels resulting in 8 series per patient. The left major fissure was manually contoured axially at regular intervals, yielding 37 contours across all patients. These contours were read into an image analysis and pattern classification system which computed a Fissure Integrity Score (FIS) for each kernel and dose. FIS values were analyzed using a mixed-effects model with kernel and dose as fixed effects and patient as random effect to test for difference due to kernel and dose. Analysis revealed no difference in FIS between the smooth kernels (B10f, B30f) nor between sharp kernels (B50f, B70f), but there was a significant difference between the sharp and smooth groups (p = 0.020). There was no significant difference in FIS between the two low-dose reconstructions (p = 0.882). Using a cutoff of 90%, the number of incomplete fissures increased from 5 to 10 when the imaging protocol changed from B50f to B30f. Reconstruction kernel has a significant effect on quantification of fissure integrity in CT. This has potential implications when selecting patients for endobronchial valve therapy.

Overlapping Ballistic Ejecta Fields: Separating Distinct Blasts at Kings Bowl, Idaho

NASA Astrophysics Data System (ADS)

Borg, C.; Kobs-Nawotniak, S. E.; Hughes, S. S.; Sears, D. W. G.; Heldmann, J. L.; Lim, D. S. S.; Haberle, C. W.; Sears, H.; Elphic, R. C.; Kobayashi, L.; Garry, W. B.; Neish, C.; Karunatillake, S.; Button, N.; Purcell, S.; Mallonee, H.; Ostler, B.

2015-12-01

Kings Bowl is a ~2200ka pit crater created by a phreatic blast along a volcanic fissure in the eastern Snake River Plain (ESRP), Idaho. The main crater measures approximately 80m in length, 30m in width, and 30m in depth, with smaller pits located nearby on the Great Rift fissure, and has been targeted by the FINESSE team as a possible analogue for Cyane Fossae, Mars. The phreatic eruption is believed to have occurred due to the interaction of groundwater with lava draining back into the fissure following a lava lake high stand, erupting already solidified basalt from this and previous ERSP lava flows. The contemporaneous draw back of the lava with the explosions may conceal some smaller possible blast pits as more lava drained into the newly formed pits. Ballistic ejecta from the blasts occur on both sides of the fissure. To the east, the ballistic blocks are mantled by fine tephra mixed with eolian dust, the result of a westerly wind during the explosions. We use differential GPS to map the distribution of ballistic blocks on the west side of the fissure, recording position, percent vesiculation, and the length of 3 mutually perpendicular axes for each block >20cm along multiple transects parallel to the fissure. From the several hundred blocks recorded, we have been able to separate the ballistic field into several distinct blast deposits on the basis of size distributions and block concentration. The smaller pits identified from the ballistic fields correspond broadly to the northern and southern limits of the tephra/dust field east of the fissure. Soil formation and bioturbation of the tephra by sagebrush have obliterated any tephrostratigraphy that could have been linked to individual blasts. The ballistic block patterns at Kings Bowl may be used to identify distinct ejecta groups in high-resolution imagery of Mars or other planetary bodies.

Revisiting dirt cracking as a physical weathering process in warm deserts

NASA Astrophysics Data System (ADS)

Dorn, Ronald I.

2011-12-01

A half century ago C.D. Ollier proposed that insolation-driven temperature changes expand and contract fill in fissures enough to widen cracks, a process that would permit progressively deeper penetration of fissure fills, that would in turn generate a positive feedback of greater and greater strain until desert boulders and bedrock shatters. Although desert physical weathering by "dirt cracking" has occasionally been cited, this hypothesized process remains without support from subsequent research. Here, field observations, electron microscopy, X-ray powder diffraction, particle-size analysis, and laboratory experiments shed new light on dirt cracking. Little clear evidence supports the original notion of expansive pressures from thermal fluctuations. However, mineralogical, high resolution transmission electron microscopy, back-scattered electron microscopy, and experimental evidence support two alternative processes of widening fractures: wetting and drying of fills inside fissures; and the precipitation and remobilization of calcium carbonate. A re-envisioned dirt-cracking wedging process starts with calcium carbonate precipitating in fissures less than 5 μm wide. First precipitation, and then ongoing dissolution of this laminar calcrete, opens enough space for dust to penetrate into these narrow fractures. Wetting of expansive clays in the fissure fill exerts enough pressure to widen and deepen the fissure, allowing the carbonate precipitation process to penetrate even deeper and allowing even more dust to move into a fracture. As the dust infiltrates, its texture changes from a chaotic mix of particles to an alignment of clays parallel to fissure sides. This parallel alignment could increase the efficiency of fill wedging. Ollier's concept of a positive feedback remains supported; each increment of fracture deepening and widening permits more, even deeper infiltration of laminar calcrete and dust. Field and electron microscope observations of rock spalling in the winter of 2010 are consistent with Ollier's hypothesis that dirt cracking is a common physical weathering process in deserts that splits rocks of all different sizes.

Treatment algorithm for anal fissure. Consensus document of the Spanish Association of Coloproctology and the Coloproctology Division of the Spanish Association of Surgeons.

PubMed

Arroyo, Antonio; Montes, Elisa; Calderón, Teresa; Blesa, Isabel; Elía, Manuela; Salgado, Gervasio; García-Armengol, Juan; de-la-Portilla, Fernando

2018-03-08

The Spanish Association of Coloproctology and the Coloproctology Division of the Spanish Association of Surgeons propose this consensus document with a treatment algorithm for anal fissure that could be used for decision making. Non-surgical therapy and surgical treatment of anal fissure are explained, and the recommended algorithm is provided. The methodology used was: creation of a group of experts; search in PubMed, MEDLINE and the Cochrane Library for publications from the last 10 years about anal fissure; presentation at the 21st National Meeting of the Spanish Association of Coloproctology Foundation 2017 with voting for/against each conclusion by the attendees and review by the scientific committee of the Spanish Association of Coloproctology. Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Three-dimensional finite elements for the analysis of soil contamination using a multiple-porosity approach

NASA Astrophysics Data System (ADS)

El-Zein, Abbas; Carter, John P.; Airey, David W.

2006-06-01

A three-dimensional finite-element model of contaminant migration in fissured clays or contaminated sand which includes multiple sources of non-equilibrium processes is proposed. The conceptual framework can accommodate a regular network of fissures in 1D, 2D or 3D and immobile solutions in the macro-pores of aggregated topsoils, as well as non-equilibrium sorption. A Galerkin weighted-residual statement for the three-dimensional form of the equations in the Laplace domain is formulated. Equations are discretized using linear and quadratic prism elements. The system of algebraic equations is solved in the Laplace domain and solution is inverted to the time domain numerically. The model is validated and its scope is illustrated through the analysis of three problems: a waste repository deeply buried in fissured clay, a storage tank leaking into sand and a sanitary landfill leaching into fissured clay over a sand aquifer.

The effect of Saqez (Pistacia atlantica) ointment on nipple fissure improvement in breastfeeding women during one-month follow-up

PubMed Central

As’adi, Nayereh; Kariman, Nourossadat; Mojab, Faraz; Pourhoseingholi, Mohamad Amin

2017-01-01

Objective: Painful nipple fissure is a troublesome problem for breastfeeding mothers. This study was conducted to evaluate the effect of saqez (Pistacia atlantica) ointment on the improvement of nipple fissure in breastfeeding women during one-month follow-up. Materials and Methods: This randomized controlled clinical trial was conducted on 100 eligible women who visited the selected health centers affiliated to Shahid Beheshti University of Medical Sciences, Tehran, Iran, from July 2015 to December 2015 during their postpartum period. A total of 100 subjects were randomly divided into two equal groups of 50 women grouped as saqez ointment group and breast milk group, and followed-up for one month. Both groups received face-to-face instructions on breastfeeding techniques. For severity of nipple fissure, Storr scale and to measure the intensity of pain, visual analog scale (VAS) were used. Results: The results showed that the two groups were matched in terms of demographic and obstetric characteristics. Mean of nipple fissure severity in ointment group (42.62) was lower than that of the control group (48.02), that was significantly different between the two groups (p=0.047). In addition, Mean nipple pain intensity in ointment group (40.57) was lower than that of the control group (49.81), but there was no significant difference between the two groups (p=0.056). Conclusion: The present study showed that saqez ointment was more effective than breast milk in healing and controlling nipple fissures during one-month follow-up, without resulting in any side effects. PMID:29299430

Comparative study of Ksharasutra suturing and Lord's anal dilatation in the management of Parikartika (chronic fissure-in-ano)

PubMed Central

Dudhamal, Tukaram S.; Baghel, Madhav Singh; Bhuyan, Chaturbhuja; Gupta, Sanjay Kumar

2014-01-01

Background: Parikartika resembles fissure-in-ano which is very common among all ano-rectal disorders. In Ayurvedic texts, Parikartika is described as a complication of Vamana and Virechana as well as complication of Atisara. Ksharasutra was proved successful in the management of fistula-in-ano, piles, and there is a need to try its efficacy in fissure-in-ano. Aim: To evaluate the role of Ksharasutra suturing (KSS) in fissure bed in chronic fissure-in-ano. Materials and Methods: Total 100 patients of chronic fissure-in-ano were selected and randomly divided into two groups (50 in each group). In group-A, patients were undergone by KSS; while in patients of Group-B Lord's anal dilatation followed by KSS was done under spinal anesthesia. The KSS was done once and after slough out of Ksharasutra, the wound was treated for 4 weeks and assessment of the result was done on the basis of gradation adopted. Results: The pain relief on 14th day in Group-A was 86% while in Group-B 100% was observed. As on 7th day in Group-A, oozing was stopped in 68% patients, while in Group-B, oozing was stopped in 82% patients. On 21st day, Group-B showed more healing (85%) as compared to Group-A (69%). In this study 68% of patients were cured. Conclusion: In Group-B (KSS with Lord's anal dilatation) patients were cured early as compared to patients of Group-A (KSS alone). PMID:25558158

Medium-term results of anal advancement flap compared with lateral sphincterotomy for the treatment of anal fissure.

PubMed

Patel, Sanjay D; Oxenham, Tom; Praveen, Bhandhipalyan V

2011-09-01

Anal fissure is associated with anal pain and bleeding. Lateral internal sphincterotomy (LIS) has been a common form of surgical management. This can however cause incontinence and hence an equally effective alternative without this risk would be ideal. Anal fissurectomy and an anal advancement flap (AAF) have been used as an alternative to LIS. We carried out a retrospective analysis of the results of AAF and LIS for the treatment of anal fissure. Fifty patients underwent AAF and a further 50 cases were chosen who had undergone LIS over the same time period. Patient and procedural data were collected including post-operative course. Presenting symptoms included anal pain (94%), rectal bleeding (77%) and constipation (15%). Mean (±SD) follow-up was 20 ± 12 months in the AAF group vs 22 ± 12.5 months in the LIS group. Healing of fissure was achieved in 96% of patients after AAF and 88% after LIS (p = 0.27). Resolution of symptoms was achieved in 90% after AAF and 72% of patients after LIS (p = 0.04). LIS was associated with an increased incidence of readmission with infection and pain (8% vs 4%, p = 0.35). Seven patients whom had undergone successful AAF with complete resolution of symptoms had previously had LIS with failure of symptom relief. There was no incidence of faecal incontinence in either group. AAF is associated with a higher incidence of symptomatic relief and fissure healing and lower incidence of complications when compared with LIS. AAF is effective at healing fissures which are refractory to LIS.

A Volcanic Fissure

NASA Image and Video Library

2017-04-26

Although Mars is known for having the largest volcano in our solar system, Olympus Mons, we also find small-scale volcanic features on its surface, as shown in this image from HiRISE onboard NASA's Mars Reconnaissance Orbiter (MRO). This fissure, less than 500 meters across at its widest point, lies in the Tharsis region and is believed to be a vent from which lava flowed in ancient eruptions. The total volume of lava released from this fissure is much less than what would erupt from nearby volcanoes, but the mark left on the landscape is dramatic nonetheless. https://photojournal.jpl.nasa.gov/catalog/PIA21601

Response of rock-fissure seepage to snowmelt in Mount Taihang slope-catchment, North China.

PubMed

Cao, Jiansheng; Liu, Changming; Zhang, Wanjun

2013-01-01

The complex physiographic and hydrogeological systems of mountain terrains facilitate intense rock-fissure seepages and multi-functional ecological interactions. As mountain eco-hydrological terrains are the common water sources of river basins across the globe, it is critical to build sufficient understanding into the hydrological processes in this unique ecosystem. This study analyzes infiltration and soil/rock-fissure seepage processes from a 65 mm snowfall/melt in November 2009 in the typical granitic gneiss slope catchment in the Taihang Mountains. The snowfall, snowmelt and melt-water processes are monitored using soil-water time-domain reflectometry (TDR) probes and tipping bucket flowmeters. The results suggest that snowmelt infiltration significantly influences soil/rock water seepage in the 0-100 cm soil depth of the slope-catchment. It is not only air temperature that influences snowmelt, but also snowmelt infiltration and rock-fissure seepage. Diurnal variations in rock-fissure seepage are in close correlation with air temperature (R(2) > 0.7). Temperature also varies with soil/rock water viscosity, which element in turn influences soil/rock water flow. Invariably, water dynamics in the study area is not only a critical water supply element for domestic, industrial and agricultural uses, but also for food security and social stability.

New type of brittle deformations: two-axial turn structure of fractures in the Kovdor carbonatite intrusion (NW Russia)

NASA Astrophysics Data System (ADS)

Zhirov, Dmitry

2017-04-01

The Earth's crust is known for a few types of structural fissuring and faults organization. First of all, this is an orthogonal or some kind of non-orthogonal fissuring network with a various number of systems. The hierarchic model is also popular since it stipulates a regular arrangement and collateral subordination of several ranks of elements relative to each other, and a general fault and/or shear zone. An axis-symmetric fissuring structure is developed in the central (ring)-type massifs and some other geological bodies. It is formed due to the progressive turn of adjoining fissure planes around the massif symmetry axis (mostly vertical) at a discrete angle (within 5-15° on the average depending on the scale and internal structural features). The investigation of the fault tectonics in the Kovdor carbonatite intrusion (NW Russia) has resulted in the identification of a new brittle deformations type. It is formed due to the simultaneous turn of fissure planes at discrete angles around two orthogonal guiding lines (axes), where one is represented by a vertical massif symmetry axis (L1), and the other axis (L2) lies horizontally in the fracture plane. Nonetheless, the rotation along the both axes is codirectional, i.e., when moving counterclockwise around the L1 axis, the L2 rotation is also counterclockwise. If we very tentatively consider a fissure as an ellipse, and take into account the whole assemblage of long and short axes, the overall picture of their spatial distribution generates a screw conoid or ordinary helicoid type structure. It will be shown as an S-shaped plane poles chain in the stereogram. A sequence of large scale fissures (longer than 100 meters), which are 25 to 100 meters apart from each other and regularly vary in strike and dip angle, is mapped in the open pit of the Kovdor apatite-magnetite deposit. The accuracy of positioning for each fissure is a few centimeters in measurement spots, with a deviation from its actual surface due to the undulation induced by the generalized plane estimated at ±1 meter. The poles of the mapped planes are plotted in the stereogram and compared with model calculations while the planes themselves are visualized in a 3D model. The behavior of the fissure selection in the stereogram and in the 3D model fully corresponds to the laws of two-axial codirectional turn of fractures. This is a new type of brittle deformations, which is of significance for the interpretation of evolutional features and modern state of the stress field in the Kovdor central-type carbonatite intrusion.

The Transcription Factor Foxg1 Promotes Optic Fissure Closure in the Mouse by Suppressing Wnt8b in the Nasal Optic Stalk

PubMed Central

Smith, Rowena; Huang, Yu-Ting; Tian, Tian; Vojtasova, Dominika; Mesalles-Naranjo, Oscar; Price, David J.

2017-01-01

During vertebrate eye morphogenesis, a transient fissure forms at its inferior part, known as the optic fissure. This will gradually close, giving rise to a healthy, spherical optic cup. Failure of the optic fissure to close gives rise to an ocular disorder known as coloboma. During this developmental process, Foxg1 is expressed in the optic neuroepithelium, with highest levels of expression in the nasal optic stalk. Foxg1−/− mutant mice have microphthalmic eyes with a large ventral coloboma. We found Wnt8b expression upregulated in the Foxg1−/− optic stalk and hypothesized that, similar to what is observed in telencephalic development, Foxg1 directs development of the optic neuroepithelium through transcriptional suppression of Wnt8b. To test this, we generated Foxg1−/−;Wnt8b−/− double mutants of either sex and found that the morphology of the optic cup and stalk and the closure of the optic fissure were substantially rescued in these embryos. This rescue correlates with restored Pax2 expression in the anterior tip of the optic fissure. In addition, although we do not find evidence implicating altered proliferation in the rescue, we observe a significant increase in apoptotic cell density in Foxg1−/−;Wnt8b−/− double mutants compared with the Foxg1−/− single mutant. Upregulation of Wnt/β-catenin target molecules in the optic cup and stalk may underlie the molecular and morphological defects in the Foxg1−/− mutant. Our results show that proper optic fissure closure relies on Wnt8b suppression by Foxg1 in the nasal optic stalk to maintain balanced apoptosis and Pax2 expression in the nasal and temporal edges of the fissure. SIGNIFICANCE STATEMENT Coloboma is an ocular disorder that may result in a loss of visual acuity and accounts for ∼10% of childhood blindness. It results from errors in the sealing of the optic fissure (OF), a transient structure at the bottom of the eye. Here, we investigate the colobomatous phenotype of the Foxg1−/− mutant mouse. We identify upregulated expression of Wnt8b in the optic stalk of Foxg1−/− mutants before OF closure initiates. Foxg1−/−;Wnt8b−/− double mutants show a substantial rescue of the Foxg1−/− coloboma phenotype, which correlates with a rescue in molecular and cellular defects of Foxg1−/− mutants. Our results unravel a new role of Foxg1 in promoting OF closure providing additional knowledge about the molecules and cellular mechanisms underlying coloboma formation. PMID:28729440

Sealing effectiveness of fissure sealant bonded with universal adhesive systems on saliva-contaminated and noncontaminated enamel

PubMed Central

Shafiei, Fereshteh; Zarean, Mehran; Razmjoei, Faranak

2018-01-01

Background The effectiveness of sealants is dependent upon their adhesion to enamel surface. The aim of the study was to evaluate the sealing ability of a pit and fissure sealant used with a universal adhesive (etch-and-rinse vs. self-etch modes) when the site is contaminated with saliva. Adhesive properties were evaluated as microleakage and scanning electron microscopic (SEM) characteristics. Material and Methods A total of 72 mandibular third molars were randomly divided into 6 groups (n=12). Occlusal pits and fissures were sealed with an unfilled resin fissure sealant (FS) material with or without saliva contamination. The groups included: 1) phosphoric acid etching + FS (control), 2) phosphoric acid etching + Scotchbond Universal (etch-and-rinse) + FS, 3) phosphoric acid etching + saliva + Scotchbond Universal (etch-and-rinse) + FS, 4) Scotchbond Universal (self-etching) + FS,5) Scotchbond Universal (self-etching) + saliva + FS, and 6) Scotchbond Universal (self-etching) + saliva + Scotchbond Universal + FS. After thermocycling, the teeth were placed in 0.5% fuchsin, sectioned, and evaluated by digital microscopy. Two samples from each group were also observed by SEM. The data were analyzed with Kruskal-Wallis and Mann-Whitney tests for a significance of p<0.05. Results There were significant differences among groups. Groups 1,2 and 4 showed the least microleakage, with no significant differences among groups. Saliva contamination led to increased microleakage and gap formation in SEM images in groups 3, 5 and 6. Conclusions The fissure sealing ability of the universal adhesive in etch-and-rinse or self-etch modes was similar to that of conventional acid etching. Saliva contamination had a negative effect on sealant adhesion to pretreated enamel. Key words:Pit and fissure sealant, Universal adhesive, Saliva. PMID:29670708

Endosonographic and manometric evaluation of internal anal sphincter in patients with chronic anal fissure and its correlation with clinical outcome after topical glyceryl trinitrate therapy.

PubMed

Pascual, Marta; Pera, Miguel; Courtier, Ricard; Gil, Mariá José; Parés, David; Puig, Sonia; Andreu, Montserrat; Grande, Luis

2007-08-01

Anorectal pressure studies have demonstrated internal anal sphincter (IAS) hypertonia in patients with chronic anal fissure. It is unknown however, if these changes in IAS function are associated with any abnormality in sphincter morphology. The first aim was to investigate the clinical characteristics and the manometric and endosonographic findings of the IAS in a cohort of patients with chronic anal fissure. The second aim was to investigate the association between these findings and the outcome with topical Glyceryl trinitrate (GTN) therapy. All patients who presented with chronic anal fissure from November 1999 to May 2004 were included after failure of conservative therapy. Anorectal manometry and anal endosonography were performed before treatment with 0.2% GTN ointment twice daily was initiated. Patients were evaluated after 8 weeks. One hundred and twenty-four patients (66 women, mean age, 45.2 +/- 14.8 years) were included. Hypertonia of the IAS was found in 84 (68%) patients. The mean maximum IAS thickness was 3.6 +/- 0.76 mm (1.6-5.5). An abnormally thick IAS, adjusted by age, was observed in 113 (91.1%) patients. We found no correlation between resting pressure and IAS thickness (r = 0.074; p = 0.41). At 8 weeks, 52 patients (42%) had healed with complete symptoms resolution. No statistically significant differences were observed when clinical features and manometric and endosonographic findings were compared between healing and no-healing fissures. The majority of patients with chronic anal fissure present an abnormally thick IAS. Clinical, manometric and endosonographic features had no association with outcome after GTN treatment.

The length of pre-existing fissures effects on the mechanical properties of cracked red sandstone and strength design in engineering.

PubMed

Wu, Jiangyu; Feng, Meimei; Yu, Bangyong; Han, Guansheng

2018-01-01

It is important to study the mechanical properties of cracked rock to understand the engineering behavior of cracked rock mass. Consequently, the influence of the length of pre-existing fissures on the strength, deformation, acoustic emission (AE) and failure characteristics of cracked rock specimen was analyzed, and the optimal selection of strength parameter in engineering design was discussed. The results show that the strength parameters (stress of dilatancy onset and uniaxial compressive strength) and deformation parameters (axial strain and circumferential strain at dilatancy onset and peak point) of cracked rock specimen decrease with the increase of the number of pre-existing fissures, and the relations which can use the negative exponential function to fit. Compared with the intact rock specimens, the different degrees of stress drop phenomena were produced in the process of cracked rock specimens when the stress exceeds the dilatancy onset. At this moment, the cracked rock specimens with the existence of stress drop are not instantaneous failure, but the circumferential strain, volumetric strain and AE signals increase burstingly. And the yield platform was presented in the cracked rock specimen with the length of pre-existing fissure more than 23mm, the yield failure was gradually conducted around the inner tip of pre-existing fissure, the development of original fissures and new cracks was evolved fully in rock. However, the time of dilatancy onset is always ahead of the the time of that point with the existence of stress drop. It indicates that the stress of dilatancy onset can be as the parameter of strength design in rock engineering, which can effectively prevent the large deformation of rock. Copyright © 2017 Elsevier B.V. All rights reserved.

Sealing effectiveness of fissure sealant bonded with universal adhesive systems on saliva-contaminated and noncontaminated enamel.

PubMed

Memarpour, Mahtab; Shafiei, Fereshteh; Zarean, Mehran; Razmjoei, Faranak

2018-01-01

The effectiveness of sealants is dependent upon their adhesion to enamel surface. The aim of the study was to evaluate the sealing ability of a pit and fissure sealant used with a universal adhesive (etch-and-rinse vs. self-etch modes) when the site is contaminated with saliva. Adhesive properties were evaluated as microleakage and scanning electron microscopic (SEM) characteristics. A total of 72 mandibular third molars were randomly divided into 6 groups (n=12). Occlusal pits and fissures were sealed with an unfilled resin fissure sealant (FS) material with or without saliva contamination. The groups included: 1) phosphoric acid etching + FS (control), 2) phosphoric acid etching + Scotchbond Universal (etch-and-rinse) + FS, 3) phosphoric acid etching + saliva + Scotchbond Universal (etch-and-rinse) + FS, 4) Scotchbond Universal (self-etching) + FS,5) Scotchbond Universal (self-etching) + saliva + FS, and 6) Scotchbond Universal (self-etching) + saliva + Scotchbond Universal + FS. After thermocycling, the teeth were placed in 0.5% fuchsin, sectioned, and evaluated by digital microscopy. Two samples from each group were also observed by SEM. The data were analyzed with Kruskal-Wallis and Mann-Whitney tests for a significance of p <0.05. There were significant differences among groups. Groups 1,2 and 4 showed the least microleakage, with no significant differences among groups. Saliva contamination led to increased microleakage and gap formation in SEM images in groups 3, 5 and 6. The fissure sealing ability of the universal adhesive in etch-and-rinse or self-etch modes was similar to that of conventional acid etching. Saliva contamination had a negative effect on sealant adhesion to pretreated enamel. Key words: Pit and fissure sealant, Universal adhesive, Saliva.

A Novel Approach to Model Earth Fissure Caused by Extensive Aquifer Exploitation and its Application to the Wuxi Case, China

NASA Astrophysics Data System (ADS)

Ye, Shujun; Franceschini, Andrea; Zhang, Yan; Janna, Carlo; Gong, Xulong; Yu, Jun; Teatini, Pietro

2018-03-01

Initially observed in the semiarid basins of southwestern USA, earth fissures due to aquifer over-exploitation are presently threatening a large number of subsiding basins in various countries worldwide. Different mechanics have been proposed to explain this process, such as differential compaction, horizontal movements, and fault reactivation. Numerical modeling and prediction of this major geohazard caused by overuse of groundwater resources are challenging because of two main requirements: shifting from the classical continuous to discontinuous geomechanics and incorporating two-dimensional features (the earth fissures) into large three-dimensional (3-D) modeling domain (the subsiding basin). In this work, we proposed a novel modeling approach to simulate earth fissure generation and propagation in 3-D complex geological settings. A nested two-scale approach associated with an original nonlinear elastoplastic finite element/interface element simulator allows modeling the mechanics of earth discontinuities, in terms of both sliding and opening. The model is applied on a case study in Wuxi, China, where groundwater pumping between 1985 and 2004 has caused land subsidence larger than 2 m. The model outcomes highlight that the presence of a shallow (˜80 m deep) bedrock ridge crossing the Yangtze River delta is the key factor triggering the earth fissure development in this area. Bending of the alluvial deposits around the ridge tip and shear stress due to the uneven piezometric change and asymmetrical shape of the bedrock have caused the earth fissure to onset at the land surface and propagate downward to a maximum depth of about 20-30 m. Maximum sliding and opening are computed in the range of 10-40 cm, in agreement with the order of magnitude estimated in the field.

Subpial Hematoma and Extravasation in the Interhemispheric Fissure with Subarachnoid Hemorrhage

PubMed Central

Matsuoka, Go; Abe, Kayoko; Okada, Yoshikazu; Sakai, Shuji

2015-01-01

A recent report on computed tomography (CT) findings of contrast extravasation in subarachnoid hemorrhage (SAH) with Sylvian hematoma suggests that the occurrence of the hematoma is secondary to bleeding in the subpial space. Our patient was in his sixties and was admitted to the hospital because of loss of consciousness (Glasgow Coma Scale E4V1M4). SAH was diagnosed in plain head CT, and growing hematomas were observed in the Sylvian and interhemispheric fissures following a subarachnoid hemorrhage. CT angiography (CTA) using a dual-phase scan protocol revealed contrast extravasation in both the fissures in the latter phase, and hematoma in the interhemispheric fissure contained multiple bleeding points. This case indicates that the occurrence of subpial hematoma such as Sylvian hematoma can be a secondary event following subpial bleeding from damaged small vessels elsewhere in the cranium. Instead of four-dimensional (4D) CT, the dual-phase CTA technique may help detect minor extravasations with usual helical CT scanner. PMID:25963159

Femtosecond Laser in situ Keratomileusis Flap Creation in Narrow Palpebral Fissure Eyes without Suction.

PubMed

Chang, John S M; Law, Antony K P; Ng, Jack C M; Cheng, May S Y

2017-01-01

To evaluate a surgical technique used in eyes with narrow palpebral fissure undergoing femtosecond laser flap creation without suction during laser in situ keratomileusis (LASIK). All data of 2 patient groups were collected through chart review. Group 1 consisted of 6 eyes with narrow palpebral fissure in which the suction ring was manually fixated and femtosecond laser was applied accordingly. Thirty comparison cases were randomly drawn from among eyes that underwent a standard LASIK procedure matched for age and preoperative refraction (group 2). Only 1 eye of each patient was selected to compare the refractive and visual outcomes between groups. In all group 1 eyes, the flaps were created successfully with manual fixation of the suction ring without suction. No eyes lost 2 or more lines of vision. No significant difference was found in the safety and refractive outcomes between groups. Manual fixation of the suction ring in eyes with narrow palpebral fissure without suction was feasible for flap creation during LASIK.

Femtosecond Laser in situ Keratomileusis Flap Creation in Narrow Palpebral Fissure Eyes without Suction

PubMed Central

Chang, John S.M.; Law, Antony K.P.; Ng, Jack C.M.; Cheng, May S.Y.

2017-01-01

Purpose To evaluate a surgical technique used in eyes with narrow palpebral fissure undergoing femtosecond laser flap creation without suction during laser in situ keratomileusis (LASIK). Methods All data of 2 patient groups were collected through chart review. Group 1 consisted of 6 eyes with narrow palpebral fissure in which the suction ring was manually fixated and femtosecond laser was applied accordingly. Thirty comparison cases were randomly drawn from among eyes that underwent a standard LASIK procedure matched for age and preoperative refraction (group 2). Only 1 eye of each patient was selected to compare the refractive and visual outcomes between groups. Results In all group 1 eyes, the flaps were created successfully with manual fixation of the suction ring without suction. No eyes lost 2 or more lines of vision. No significant difference was found in the safety and refractive outcomes between groups. Conclusion Manual fixation of the suction ring in eyes with narrow palpebral fissure without suction was feasible for flap creation during LASIK. PMID:28690535

Automatic lung lobe segmentation using particles, thin plate splines, and maximum a posteriori estimation.

PubMed

Ross, James C; San José Estépar, Rail; Kindlmann, Gordon; Díaz, Alejandro; Westin, Carl-Fredrik; Silverman, Edwin K; Washko, George R

2010-01-01

We present a fully automatic lung lobe segmentation algorithm that is effective in high resolution computed tomography (CT) datasets in the presence of confounding factors such as incomplete fissures (anatomical structures indicating lobe boundaries), advanced disease states, high body mass index (BMI), and low-dose scanning protocols. In contrast to other algorithms that leverage segmentations of auxiliary structures (esp. vessels and airways), we rely only upon image features indicating fissure locations. We employ a particle system that samples the image domain and provides a set of candidate fissure locations. We follow this stage with maximum a posteriori (MAP) estimation to eliminate poor candidates and then perform a post-processing operation to remove remaining noise particles. We then fit a thin plate spline (TPS) interpolating surface to the fissure particles to form the final lung lobe segmentation. Results indicate that our algorithm performs comparably to pulmonologist-generated lung lobe segmentations on a set of challenging cases.

Automatic Lung Lobe Segmentation Using Particles, Thin Plate Splines, and Maximum a Posteriori Estimation

PubMed Central

Ross, James C.; Estépar, Raúl San José; Kindlmann, Gordon; Díaz, Alejandro; Westin, Carl-Fredrik; Silverman, Edwin K.; Washko, George R.

2011-01-01

We present a fully automatic lung lobe segmentation algorithm that is effective in high resolution computed tomography (CT) datasets in the presence of confounding factors such as incomplete fissures (anatomical structures indicating lobe boundaries), advanced disease states, high body mass index (BMI), and low-dose scanning protocols. In contrast to other algorithms that leverage segmentations of auxiliary structures (esp. vessels and airways), we rely only upon image features indicating fissure locations. We employ a particle system that samples the image domain and provides a set of candidate fissure locations. We follow this stage with maximum a posteriori (MAP) estimation to eliminate poor candidates and then perform a post-processing operation to remove remaining noise particles. We then fit a thin plate spline (TPS) interpolating surface to the fissure particles to form the final lung lobe segmentation. Results indicate that our algorithm performs comparably to pulmonologist-generated lung lobe segmentations on a set of challenging cases. PMID:20879396

King's Bowl Pit Crater, Lava Field and Eruptive Fissure, Idaho - A Multipurpose Volcanic Planetary Analog

NASA Astrophysics Data System (ADS)

Hughes, S. S.; Garry, B.; Kobs-Nawotniak, S. E.; Sears, D. W. G.; Borg, C.; Elphic, R. C.; Haberle, C. W.; Kobayashi, L.; Lim, D. S. S.; Sears, H.; Skok, J. R.; Heldmann, J. L.

2014-12-01

King's Bowl (KB) and its associated eruptive fissure and lava field on the eastern Snake River Plain, is being investigated by the NASA SSERVI FINESSE (Field Investigations to Enable Solar System Science and Exploration) team as a planetary analog to similar pits on the Moon, Mars and Vesta. The 2,220 ± 100 BP basaltic eruption in Craters of the Moon National Monument and Preserve represents early stages of low shield growth, which was aborted when magma supply was cut off. Compared to mature shields, KB is miniscule, with ~0.02 km3 of lava over ~3 km2, yet the ~6 km long series of fissures, cracks and pits are well-preserved for analog studies of volcanic processes. The termination of eruption was likely related to proximity of the 2,270 ± 50 BP eruption of the much larger Wapi lava field (~5.5 km3 over 325 km2 area) on the same rift. Our investigation extends early work by R. Greeley and colleagues, focusing on imagery, compositional variations, ejecta distribution, dGPS profiles and LiDAR scans of features related to: (1) fissure eruptions - spatter ramparts, cones, feeder dikes, extension cracks; (2) lava lake formation - surface morphology, squeeze-ups, slab pahoehoe lava mounds, lava drain-back, flow lobe overlaps; and (3) phreatic steam blasts - explosion pits, ejecta blankets of ash and blocks. Preliminary results indicate multiple fissure eruptions and growth of a basin-filled lava lake up to ~ 10 m thick with outflow sheet lava flows. Remnant mounds of original lake crust reveal an early high lava lake level, which subsided as much as 5 m as the molten interior drained back into the fissure system. Rapid loss of magma supply led to the collapse of fissure walls allowing groundwater influx that triggered multiple steam blasts along at least 500 m. Early blasts occurred while lake magma pressure was still high enough to produce squeeze-ups when penetrated by ejecta blocks. The King's Bowl pit crater exemplifies processes of a small, but highly energetic eruption that ejected blocks up to 2 m strewn over 200 m onto the lava lake surface.

Coupling Eruptive Dynamics Models to Multi-fluid Plasma Dynamic Simulations at Enceladus

NASA Astrophysics Data System (ADS)

Paty, C. S.; Dufek, J.; Waite, J. H.; Tokar, R. L.

2011-12-01

The interaction of Saturn's magnetosphere with Enceladus provides an exciting natural laboratory for expanding our understanding of charge-neutral-dust interactions and their impact on mass and momentum loading of the system and the associated magnetic perturbations. However, one of the more challenging questions regarding the Enceladus plume relates to the subsurface eruptive mechanism responsible for generating the observed jets of material that compose the plume, and the three-dimensional distribution of neutral gas and dust in the plume. In this work we implement a multiphase eruptive dynamics model [cf. Dufek & Bergantz, 2007; Dufek and Bergantz, 2005] to examine the evolution of the plume morphology for a given eruption. We model the eruptive mechanism in a two-part, coupled domain including a fissure model and a plume model. A high resolution, multiphase, fissure model examines eruptive processes in a fissure from fragmentation to the surface. The fissure model is two-dimensional and provides spatial and temporal information about the dust/ice grains and gas. The depth to the fragmentation surface is currently treated as a free parameter and we examine a range of fissure morphologies. We do not explicitly force choked conditions at the vent, but rather due to the geometry, the velocities of the particle and gas mixture approach the sound speed for a 'dusty' gas mixture. The fissure model provides a source for the 3D plume model which examines the morphology of the plume resulting from different fissure configurations and provides a self-consistent physical basis to link concentrations in different regions of the plume to an eruptive mechanism. These initial models describing the resulting gas and dust grain distribution will be presented in the context of existing observations. We will also demonstrate the first stages of integration of these results into the existing multi-fluid plasma dynamic simulations of Enceladus' interaction with Saturn's magnetosphere. These more sophisticated plume morphologies and their effects on the plasma dynamic interaction will be assessed in the context of existing modeling efforts for this system.

Dental Pit and Fissure Sealants: Implications for School Health Personnel.

ERIC Educational Resources Information Center

McCormack-Brown, K. R.; And Others

1989-01-01

To promote good personal hygiene practices in students, school health personnel must be informed about dental pit and fissure sealants and related programs. Adoption and maintenance of such programs may depend on the success of school health personnel in educating administrators and policymakers. (SM)

Internal sphincterotomy versus topical nitroglycerin ointment for chronic anal fissure.

PubMed

Aslam, Muhammad I; Pervaiz, Arif; Figueiredo, Rodrigo

2014-01-01

Anal fissure is a common benign condition. An anorectal problem is defined as a split in the anal canal mucosa that extends from the dentate line to the anal verge. Chronic anal fissure is defined by a history of symptoms present for more than 2 months' duration and with a triad of external skin tags, namely, a hypertrophied anal papilla, an ulcer with rolled edges, and a base exposing the internal sphincter. Because complications such as incontinence are associated with surgical treatment, chemical sphincterotomy is currently favored. The objective of this study is to compare the difference in outcome between open partial lateral anal sphincterotomy and application of topical 0.2% nitroglycerin ointment for the treatment of chronic anal fissure. This was a quasi-experimental study carried out between January 16, 2007 and January 15, 2008 in the Surgical Department of Jinnah Hospital, Lahore, Pakistan. Sixty consecutive cases with a clinical diagnosis of chronic anal fissure were recruited in the study. All recruited patients met the study inclusion criteria and were randomly assigned to one of the two groups. Group A was managed conservatively using topical 0.2% nitroglycerin ointment, whereas Group B underwent open partial lateral anal sphincterotomy. Both groups were followed up at 1 week, 2 weeks, 4 weeks, and 6 weeks after the treatment. All the patients complained of pain. A total of 43 (71.7%) patients had pain with constipation, whereas 31 (51.7%) patients had bleeding per rectum. Upon clinically examining the anal area, tenderness was elicited in all 60 (100%) patients. Group A included 30 (11 females and 19 males) cases treated with topical 0.2% nitroglycerin ointment and Group B included 30 (11 females and 19 males) cases who underwent open partial lateral anal sphincterotomy. In Group A, only 15 patients with fissures were successfully treated (50%). By contrast, 28 (93%) patients with fissures in Group B were successfully treated, and only two (7%) remained uncured. These two patients (6.6%) in Group B suffered from incontinence due to flatus and feces as a complication of the procedure. This quasi-experimental study demonstrates that open partial lateral internal sphincterotomy is superior to topical 0.2% nitroglycerin application in the treatment of chronic anal fissure, with good symptomatic relief, high rate of healing, fewer side effects, and a very low rate of early continence disturbances. Copyright © 2013. Published by Elsevier B.V.

Deformation Associated With the July 21 Fissure Eruption at Kilauea Volcano, Hawai`i

NASA Astrophysics Data System (ADS)

Poland, M.; Orr, T.; Miklius, A.

2007-12-01

Deformation measurements at the Pu`u `O`o cone on Kilauea volcano indicate that the vent is underlain by a shallow magma storage reservoir fed by magma transported from Kilauea's summit. The Pu`u `O`o reservoir was drained during the "Father's&pDay" intrusion of June 17-19, 2007, causing Pu`u `O`o's floor to collapse. Following the intrusion, the reservoir gradually refilled and lava reappeared on July 1-2. A lava lake grew in the crater during July 2-20, steadily raising the elevation of the crater floor. The crater interior and adjoining walls began to uplift on July 10, and 2 days later lava began to vent above the level of the lava lake along the margins of the crater. The number of crater margin vents and the magnitude of their activity increased until July 21, by which time crater uplift amounted to about 8 meters. Early that morning, the lava pond at Pu`u `O`o drained suddenly and an eruptive fissure opened on the east flank of the cone. The fissure propagated 2 km downrift, and within a few hours the eruption had localized on three fissure segments between 1 and 2 km east of Pu`u `O`o. Lava erupting from this series of vents formed a system of perched lava ponds feeding long `a`a flows. Deformation associated with the July 21 fissure was exceptionally well-documented by a borehole tiltmeter on the north flank of Pu`u `O`o and 7 continuous GPS stations within 2 km of the cone (the fissure propagated between two of these GPS stations). The time series of geodetic measurements suggests that deflation of Pu`u `O`o began at about 2250 HST (Hawaiian Standard Time - UTC minus 10 hours) on July 20, while a camera looking into Pu`u `O`o crater recorded draining of the lava lake starting at around 2355 HST. Deformation associated with opening of the fissure was apparent in the tilt and GPS records by 0012 HST, with the camera showing glow in the direction of the eruption site by 0039 HST on July 21. Localized deformation from InSAR suggests that the fissure has a shallow source, probably within 1 km of the surface; this interpretation is also supported by kinematic GPS results collected from points around Pu`u `O`o in July 2006 and July 2007.

Hemorrhoids and anal fissures in inflammatory bowel disease.

PubMed

D'Ugo, S; Stasi, E; Gaspari, A L; Sileri, P

2015-12-01

Perianal disease is a common complication of inflammatory bowel disease (IBD). It includes different conditions from more severe and potentially disabling ones, such as abscesses and fistulas, to more benign conditions such as hemorrhoids, skin tags and fissures. Most literature has been focused on anal sepsis and fistulae, as they carry the majority of disease burden and often alter the natural course of the disease. Hemorrhoids and anal fissures in patients with IBD have been overlooked, although they can represent a challenging problem. The management of hemorrhoids and fissures in IBD patients may be difficult and may significantly differ compared to the non-affected population. Historically surgery was firmly obstructed, and hemorrhoidectomy or sphincterotomy in patients with associated diagnosis of IBD was considered harmful, although literature data is scant and based on small series. Various authors reported an incidence of postoperative complications higher in IBD than in the general populations, with potential severe events. Considering that a spontaneous healing is possible, the first line management should be a medical therapy. In patients non-responding to conservative measures it is possible a judicious choice of surgical options on a highly selective basis; this can lead to acceptable results, but the risk of possible complications needs to be considered. In this review it is analyzed the current literature on the incidence, symptoms and treatment options of hemorrhoids and anal fissures in patients with Crohn's disease and ulcerative colitis.

An in vitro investigation of pre-treatment effects before fissure sealing.

PubMed

Bagheri, Mahshid; Pilecki, Peter; Sauro, Salvatore; Sherriff, Martyn; Watson, Timothy F; Hosey, Marie Therese

2017-11-01

Fissure sealants prevent occlusal caries in permanent molars. Enamel preparation methods are used before fissure sealing. To investigate effects of bioglass air-abrasion pre-treatment with and without an adhesive, on fissure enamel of permanent teeth, with respect to etchability, microleakage and microtensile bond strength. Half of the occlusal surfaces of 50 extracted premolars underwent bioglass air-abrasion. Dye was applied to the entire occlusal surface. Photographs were taken to score etched surface by dye uptake. Adhesive was applied to 25 of the bioglass-treated areas and all teeth were fissure sealed, sectioned, and evaluated using confocal microscopy. Buccal and lingual surfaces of a further eight premolars were acid-etched and randomly received: air-abrasion, adhesive, both, or none before sealant application for microtensile bond strength measurement in half of the samples immediately and half following 6 months of water immersion. Linear mixed models and multinomial logistic regression were used (P = 0.05). Bioglass air-abrasion significantly improved enamel etchability and reduced microleakage. The addition of an adhesive made no difference to either microleakage or microtensile bond strength. The combination of bioglass abrasion and adhesive led to more cohesive, rather than adhesive, failure. Bioglass air-abrasion improved enamel etchability and reduced microleakage irrespective of the adhesive use but neither pre-treatment affected the microtensile bond strength. © 2017 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Morbidity associated with treatment of chronic anal fissure

PubMed Central

Latif, Ansar; Ansar, Anila; Butt, Muhammad Qasim

2013-01-01

Objective: To assess the effectiveness of different modes of treatment of chronic anal fissure as regards improvement of symptoms and complications. Methods: This prospective study included 129 consecutive patients with chronic anal fissures presented to the Surgical Outpatients’ Department of Islam Teaching Hospital Sialkot, Pakistan; from September 2010 to November 2012. Patients were distributed in three groups. In “OBG group”, patients had attended Gynae/Obs OPD and got treated and were then referred to surgical OPD for failure of treatment or recurrence. Patients who presented with history of treatment by GPs were included in “GP Group” “SGR Group” included those who directly reported to surgical OPD for treatment. Patients were managed both pharmacologically as OPD patients and surgically as admitted patients. Patients were instructed to apply small amounts of 0.2% GTN paste in soft white paraffin, to the anoderm with finger tips three times a day. Patients were evaluated at two-week intervals and at each visit the symptoms control, adverse effects and fissure status were recorded. If there was symptomatic relief or the fissure healing was in progress, the treatment was continued for a total duration of eight weeks. Operated patients were nursed in wards after surgery i.e Internal Anal Sphicterotomy. They were advised to report to OPD weekly for one month or earlier if they experienced any symptoms suggestive of complications. Patients were declared cured in case of complete symptomatic relief with fissure healing. Success, failure and associated problems were recorded and analysed to get results. Results:This study included 129 patients who could be followed up for a minimum of three months. These patients were referred by gynaecologist i.e. 22 (17%) for treatment failure while 5 patients with wrong diagnosis were not included in statistical analysis; similarly 41 (32%) patients were referred by general practitioners and 9 patients with wrong diagnosis were excluded. Sixty six patients i.e. 51% were those who directly reported to surgical OPD and had no previous treatment. With surgical treatment, pain, bleeding per rectum and constipation showed significant improvement as compared to GTN ointment application. Fissure healing was 100% in surgical group as compared to 74% in medical group. Complications were recorded and were found to be headache with medical treatment; while the most feared complication with surgical treatment i.e. permanent incontinence was not encountered in our study. Conclusion: Topical glyceryl trinitrate is economical, has a good healing rate, and faecal incontinence has not been reported. Its effectiveness, however, depends on patients’ compliance which may be poor in view of associated headaches and a local burning sensation. It is first line of treatment for anal fissure but lateral internal sphincterotomy is superior, more effective and curative than the chemical sphincterotomy. Surgery is reserved for people with anal fissure who have tried medical therapy for at least one to three months but failed. PMID:24353726

Giant desiccation fissures on the Black Rock and Smoke Creek Deserts, Nevada

USGS Publications Warehouse

Willden, R.; Mabey, D.R.

1961-01-01

Open fissures, from 100 to several hundred feet apart, that have produced polygonal patterns on the Black Rock Desert, Nevada, are believed to be giant desiccation cracks resulting from a secular trend toward aridity in the last few decades. Similar features on the Smoke Creek Desert probably have the same origin.

Phase Transformations in a Human Tooth Tissue at the Initial Stage of Caries

PubMed Central

Prutskij, Tatiana; Ippolitov, Yury

2015-01-01

The aim of the paper is to study phase transformations in solid tissues of the human teeth during the development of fissure caries by Raman and fluorescence microspectroscopy. The study of the areas with fissure caries confirmed the assumption of the formation of a weak interaction between phosphate apatite enamel and organic acids (products of microorganisms). The experimental results obtained with by Raman microspectroscopy showed the formation of dicalcium phosphate dihydrate - CaHPO4-2H2O in the area of mural demineralization of carious fissure. A comparative analysis of structural and spectroscopic data for the intact and carious enamel shows that emergence of a more soluble phase - carbonate-substituted hydroxyapatite - is typical for the initial stage of caries. It is shown that microareas of dental hard tissues in the carious fissure due to an emerging misorientation of apatite crystals have a higher fluorescence yield than the area of the intact enamel. These areas can be easily detected even prior to a deep demineralization (white spot stage) for the case of irreversibly changed organomineral complex and intensive removal of the mineral component. PMID:25901743

Endoscopic endonasal anatomy of superior orbital fissure and orbital apex regions: critical considerations for clinical applications.

PubMed

Dallan, Iacopo; Castelnuovo, Paolo; de Notaris, Matteo; Sellari-Franceschini, Stefano; Lenzi, Riccardo; Turri-Zanoni, Mario; Battaglia, Paolo; Prats-Galino, Alberto

2013-05-01

The superior orbital fissure is a critical three-dimensional space connecting the middle cranial fossa and the orbit. From an endoscopic viewpoint, only the medial aspect has a clinical significance. It presents a critical relationship with the lateral sellar compartment, the pterygopalatine fossa and the middle cranial fossa. The connective tissue layers and neural and vascular structures of this region are described. The role of Muller's muscle is confirmed, and the utility of the maxillary and optic strut is outlined. Muller's muscle extends for the whole length of the inferior orbital fissure, passes over the maxillary strut and enters the superior orbital fissure, representing a critical surgical landmark. Dividing the tendon between the medial and inferior rectus muscle allows the identification of the main trunk of the oculomotor nerve, and a little laterally, it is usually possible to visualize the first part of the ophthalmic artery. Based on a better knowledge of anatomy, we trust that this area could be readily addressed in clinical situations requiring an extended approach in proximity of the orbital apex.

The student's dilemma, liver edition: incorporating the sonographer's language into clinical anatomy education.

PubMed

Hall, M Kennedy; Mirjalili, S Ali; Moore, Christopher L; Rizzolo, Lawrence J

2015-01-01

Anatomy students are often confused by multiple names ascribed to the same structure by different clinical disciplines. Increasingly, sonography is being incorporated into clinical anatomical education, but ultrasound textbooks often use names unfamiliar to the anatomist. Confusion is worsened when ultrasound names ascribed to the same structure actually refer to different structures. Consider the sonographic main lobar fissure (MLF). The sonographic MLF is a hyper-echoic landmark used by sonographers of the right upper quadrant. Found in approximately 70% of people, there is little consensus on what the sonographic MLF is anatomically. This structure appears to be related to the main portal fissure (aka principal plane of the liver or principal hepatic fissure), initially described by anatomists and surgeons as in intrahepatic division along the middle hepatic vein which in essence divides the territories of the left and right hepatic arteries and biliary systems. By exploring the relationship between the main portal fissure and the sonographic MLF in cadaveric livers ex vivo, the data suggest the sonographic MLF is actually an extrahepatic structure that parallels the rim of the main portal fissure. The authors recommend that this structure be renamed the "sonographic cystic pedicle," which includes the cystic duct and ensheathing fat and blood vessels. In the context of the redefined underlying anatomy, the absence of the sonographic cystic pedicle due to anatomic variation may serve an important clinical role in predicting complications from difficult laparoscopic cholecystectomies and is deserving of future study. © 2015 American Association of Anatomists.

A Comparative Evaluation of the Effect of Bonding Agent on the Tensile Bond Strength of Two Pit and Fissure Sealants Using Invasive and Non-invasive Techniques: An in-vitro Study.

PubMed

Singh, Shamsher; Adlakha, Vivek; Babaji, Prashant; Chandna, Preetika; Thomas, Abi M; Chopra, Saroj

2013-10-01

Newer technologies and the development of pit and fissure sealants have shifted the treatment philosophy from 'drill and fill' to that of 'seal and heal'. The purpose of this in-vitro study was to evaluate the effects of bonding agents on the tensile bond strengths of two pit and fissure sealants by using invasive and non-invasive techniques. One hundred and twenty bicuspids were collected and teeth were divided into two groups: Group-I (Clinpro) and Group-II (Conseal f) with 60 teeth in each group. For evaluating tensile bond strengths, occlusal surfaces of all the teeth were flattened by reducing buccal and lingual cusps without disturbing fissures. Standardised polyvinyl tube was bonded to occlusal surfaces with respective materials. Sealants were applied, with or without bonding agents, in increments and they were light cured. Tensile bond strengths were determined by using Universal Testing Machine. Data were then statistically analysed by using Student t-test for comparison. A statistically significant difference was found in tensile bond strength in invasive with bonding agent group than in non-invasive with bonding agent group. This study revealed that invasive techniques increase the tensile bond strengths of sealants as compared to non- invasive techniques and that the use of a bonding agent as an intermediate layer between the tooth and fissure sealant is beneficial for increasing the bond strength.

Who discovered the sylvian fissure?

PubMed

Collice, Massimo; Collice, Rosa; Riva, Alessandro

2008-10-01

Cerebral convolutions were unknown until the 17th century. A constant sulcus was not recognized until the mid-1600s; it was named "the fissure of Sylvius," after the person who had always been considered as the one who discovered it. It is commonly asserted that the first description of the lateral scissure was made by Caspar Bartholin, who attributed its discovery to Sylvius. However, this was not actually the case, as Caspar Bartholin died in 1629, whereas Sylvius started studying medicine in 1632. The description could have been made either by Caspar Bartholin's son Thomas or by Sylvius himself. Irrespective of the description's author, the key to the history of the lateral fissure is that it was first identified by Fabrici d'Acquapendente in 1600, 40 years before Sylvius' description. In one of the 300 colored plates (Tabulae Pictae) by Fabrici, the lateral fissure is perfectly depicted, as are the temporal convolutions. Therefore, even if it was an accidental discovery, Fabrici should be the one noted as having discovered the fissure. This article ends with a short history of the plates. They were painted in oil on paper and were thought to further a great work, the Theatrum Totius Animalis Fabricae, which was begun in 1591 and never completed or published. Only the colored illustrations of this project remain. These plates were forgotten for more than 200 years, until they were rediscovered by Giuseppe Sterzi in 1909. They are among the best examples of anatomic iconography in terms of innovation, accuracy, and artistic accomplishment.

Seismic and Infrasound Recordings from Kilauea Volcano: Volcanic Tremor, Lava Outbreaks, and Fissure Eruptions

NASA Astrophysics Data System (ADS)

Fee, D.; Garces, M.; Orr, T.

2007-12-01

The continuous effusion from the Pu'u 'O'o crater complex, the active vent of Kilauea Volcano, Hawaii, produced nearly continuous tremor for years. Recently this tremor was recorded by two infrasound arrays, one at 12.5 km and one at 2.5 km, as well as a broadband seismometer at the closer array. These recordings exhibit significant temporal changes. A sharp, complex spectral peak of ~0.6 Hz is present in nearly the entire dataset, and tends to bifurcate and shift frequency over time. Although the seismic wavefield at Kilauea is complex and path effects appear to play a significant role, this spectral peak is also weakly manifested in the seismic recordings. Array processing of the infrasonic data reveals an abundance of broadband signal as well. Most of the signal appears to originate from the main crater region. However, the 2.5 km array detected the presence of a skylight with growing hornitos ~400 m south of Pu'u 'O'o on the active lava tube system. On June 19th, 2007, the magmatic system at Pu'u 'O'o changed. An intrusion of magma reached the surface 6 km west of the crater complex. The timing and location of the lava outbreak were determined acoustically using array processing. Two distinct acoustic pulses were recorded from the correct azimuth, both exhibiting harmonics. The 7/21 fissure eruption also produced clear infrasound signals. The onset of the fissure eruption east of P'u' 'O'o was apparent beginning around midnight on 7/21 and was focused between ~1.5-5 Hz. Although the fissure eruption continued to produce infrasound, the character of the recorded signal changes over time. A third infrasound array was placed closer to P'u' 'O'o and the fissure to help further constrain the eruption. More detailed results on acoustic signals from the Father's Day Intrusion and Fissure eruption will be presented.

Can earthquake fissures predispose hillslopes to landslides? - Evidence from Central and East Asia

NASA Astrophysics Data System (ADS)

Sidle, Roy C.; Gomi, Takashi; Rajapbaev, Muslim; Chyngozhoev, Nurstan

2017-04-01

Factors affecting earthquake-initiated landslides include earthquake magnitude, focal depth, and seismic wave propagation and attenuation. In contrast to rainfall-initiated landslides, earthquake-induced landslides often occur on convex slopes and near ridgelines. Here we present evidence from Fergana Basin, Kyrgyzstan and Kumamoto, Japan on how fissures developed during earthquakes may promote subsequent initiation of rainfall-triggered landslides. More than 1800 recent major landslides in hilly terrain and soft sediments of the Fergana Basin have been largely attributed to accumulation of heavy rainfall and snowmelt. While no large earthquakes have occurred in the Fergana Basin, smaller earthquakes have generated fissures near ridgelines and on convex slopes. The connection of fissures, developed years or decades before slope failure, with preferential transport of rainwater and runoff into the soil has not been previously investigated. Fissures have been observed to expand with time, particularly during subsequent minor earthquakes, further promoting preferential infiltration. Because the soil mantle does not have large contrasts in permeability that would define a slip plane for landslides, it appears that the position and depth of these fissures may control the location and depth of failures. Zones in the soil where surficial inputs of water are preferentially transported, augment natural subsurface accumulation of antecedent rainfall. Many landslides in the eastern Fergana Basin occur after several months of accumulated precipitation and groundwater has been observed emerging on critical hillside locations (near ridgelines and on convex slopes) prior to slope failure. During the 2016 Kumamoto Earthquake (M 7.3), many landslides were triggered in forest and grassland hillslopes near Mount Aso. All of these earthquakes were shallow (focal depths about 10 km), causing high shaking intensity and ground rupturing. Because soils were relatively dry during these earthquakes, occurrence of debris flows was limited. Instead, most landslides travelled limited distances and consisted of ruptured soil blocks. Large, parallel fissures developed along ridgelines and convex slopes, providing opportunities for preferential flow to initiate mass wasting during later heavy rainfalls. The progressive deterioration of ridgelines could change future catchment drainage patterns. Additionally, sediment accumulated in headwater channels from the initial earthquake-triggered landslides may mobilize as devastating debris flows after additional sediment loading during a large storm. As such, cascading effects of prior earthquakes on later mass wasting appear evident in both regions.

Prevalence of Dental Caries and Fissure Sealants in a Portuguese Sample of Adolescents

PubMed Central

Veiga, Nélio J.; Pereira, Carlos M.; Ferreira, Paula C.; Correia, Ilidio J.

2015-01-01

Introduction The aims of this study were to assess the prevalence of dental caries and the DMFT index, as well as the distribution pattern of pit and fissure sealants on permanent teeth in a Portuguese sample of adolescents, and to assess whether the existing usage of sealants and socio-demographic factors are correlated to caries prevalence on the examined sample. Materials and Methods A cross-sectional study was designed with a sample of 447 adolescents aged 12 to 18 years old, attending a public school in Sátão, Portugal. A self-administered questionnaire with questions about oral health behaviours and socio-economic status was answered by adolescents in the classroom. Clinical examination of oral health status and assessment of fissure sealants were accomplished by only one trained member of the research team. Results We obtained a DMFT index of 3.32 (2.92), which indicates a moderate level of prevalence of dental caries. When considering a DMFT = 0, we found significant statistical differences between the parents´ level of education (≤ 4th grade = 26.3 vs 5th–12th grade = 18.8 vs <12th grade = 43.3, p = 0.001), gender (male = 27.3 vs female = 19.6, p = 0.04), age (≤15 years = 27.1 vs <15 years = 18.5, p = 0.02), presence of fissure sealants (yes = 30.6 vs no = 13.5, p = 0.001) and experience of dental pain (no = 25.4 vs yes = 16.8, p = 0.02). When analyzing the prevalence of fissure sealants, we verified that 58.8% of adolescents had at least one fissure sealant applied. Significant statistical differences were found when analyzing the presence of fissure sealants related with parents´educational level (<9th grade, OR = 1.56 CI95% = 1.05–2.54), gender (female, OR = 1.86 CI95% = 1.19–2.98), experience of dental pain (yes, OR = 0.62 CI95% = 0.39–0.97) and presence of dental caries (yes, OR = 0.35 CI95% = 0.19–0.65). Conclusions The moderate level of caries prevalence reveals the need of improvement of primary prevention interventions among Portuguese adolescents. The establishment of a more targeted preventive program with better and more effective oral health education is essential, having into account socio-demographic aspects. PMID:25803849

Multispectral near-infrared reflectance and transillumination imaging of occlusal carious lesions: variations in lesion contrast with lesion depth

NASA Astrophysics Data System (ADS)

Simon, Jacob C.; Curtis, Donald A.; Darling, Cynthia L.; Fried, Daniel

2018-02-01

In vivo and in vitro studies have demonstrated that near-infrared (NIR) light at λ=1300-1700-nm can be used to acquire high contrast images of enamel demineralization without interference of stains. The objective of this study was to determine if a relationship exists between the NIR image contrast of occlusal lesions and the depth of the lesion. Extracted teeth with varying amounts of natural occlusal decay were measured using a multispectral-multimodal NIR imaging system which captures λ=1300-nm occlusal transillumination, and λ=1500-1700-nm cross-polarized reflectance images. Image analysis software was used to calculate the lesion contrast detected in both images from matched positions of each imaging modality. Samples were serially sectioned across the lesion with a precision saw, and polarized light microscopy was used to measure the respective lesion depth relative to the dentinoenamel junction. Lesion contrast measured from NIR crosspolarized reflectance images positively correlated (p<0.05) with increasing lesion depth and a statistically significant difference between inner enamel and dentin lesions was observed. The lateral width of pit and fissures lesions measured in both NIR cross-polarized reflectance and NIR transillumination positively correlated with lesion depth.

Tensions and Fissures: The Politics of Standardised Testing and Accountability in Ontario, 1995-2015

ERIC Educational Resources Information Center

Pinto, Laura Elizabeth

2016-01-01

While Ontario has received international accolades for its enactment of province-wide standardised testing upon the formation of the Education Quality and Accountability Office (EQAO), a closer look at provincial assessments over a 20-year span reveals successes as well as systemic tensions and fissures. The purpose of this paper is twofold.…

Rice fissure resistance QTLs from ‘Saber’ complement those from ‘Cypress’

USDA-ARS?s Scientific Manuscript database

The economic value of broken rice is about half that of whole milled rice, so one goal of producers, millers, and rice breeders is to reduce grain breakage during the dehusking and milling processes. One of the primary causes of rice breakage is fissuring, or cracking, of the rice before it enters ...

Identification of genetic loci underlying the kernel fissure-resistance exhibited by 'cypress' and 'saber'

USDA-ARS?s Scientific Manuscript database

The economic value of broken rice is about half that of whole milled rice, so one goal of producers, millers, and rice breeders is to reduce broken grains that result from the dehusking and milling processes One of the primary causes of rice breakage is fissuring, or cracking, of the rice before it ...

Ground fissures in the area of Mavropigi Village (N. Greece): Seismotectonics or mining activity?

NASA Astrophysics Data System (ADS)

Kalogirou, Eleni; Tsapanos, Theodoros; Karakostas, Vassilios; Marinos, Vassilios; Chatzipetros, Alexandros

2014-12-01

In the beginning of July 2010, a ground fissure was observed in the field near the village of Mavropigi (Northern Greece) and specifically in its NW side. Later on (early September), a second ground fissure was perceived, close and almost parallel to the first one and very close to the limits of the lignite exploitation mine (by the Public Power Corporation, PPC). It was observed that the village of Mavropigi slides away slowly towards the PPC lignite mine. Geological, seismological, as well as geotechnical survey in the field indicated that the phenomenon is related to the coal mining exploitation in the near vicinity of the village rather than to any seismotectonic activity in the surrounding area.

Noninvasive pit and fissure sealing: microtensile bond strength to intact bovine enamel of different pit and fissure sealants in a simplified fissure model.

PubMed

Papacchini, Federica; Cury, Alvaro H; Goracci, Cecilia; Chieffi, Nicoletta; Tay, Franklin R; Polimeni, Antonella; Ferrari, Marco

2006-12-01

To measure the microtensile bond strength of different pit and fissure sealants in a simplified fissure model. Twenty extracted bovine mandibular permanent incisors were randomly divided into 4 groups for treatment: G1: 35% phosphoric acid/Clinpro Sealant; G2: 35% phosphoric acid/Delton; G3: Non-Rinse Conditioner/Dyract Seal; G4: 20% polyacrylic acid/Fuji IILC. Each tooth was sectioned into 6 pieces (4 x 6 mm) of buccal enamel. SEM examination was used to confirm the presence of aprismatic enamel on each tooth. Using a spacer, two pieces of etched enamel were secured to a glass slide at a mean distance of 0.6+/-0.1 mm. The space between enamel substrates was then etched/conditioned and sealed with different materials according to the tested groups. By serially cutting each double-bonded sample, multiple beam-shaped specimens about 0.8mm(2) in cross section were obtained and tested in tension (0.5 mm/min) until failure occurred at either one of the two stressed interfaces. Failure modes were classified by stereomicroscopy. G1 and G2 showed statistically higher bond strengths than G3 and G4. G4 demonstrated the significantly lowest bond strength. Failures were mostly adhesive in G1, G2, G3, and mainly cohesive/mixed in G4. According to this model, resin-based materials (Clinpro Sealant, Delton) showed better microtensile bond strength than compomer (Dyract Seal) or resin-modified glass ionomer (Fuji IILC).

Topographic measurements of eyelids and orbit in enucleated eyes with hydroxyapatite integrated implant versus PMMA implant.

PubMed

Gradinaru, S; Totir, M; Iancu, R; Leasu, C; Pricopie, S; Yasin, S; Ciuluvica, R; Ungureanu, E

2014-01-01

This study reports our results relating to palpebral eyelid fissure and orbital measurements following evisceration with orbital implantation of hydroxyapatite integrated implant and PMMA implant. This study is a prospective study of 43 patients that underwent evisceration for different ocular affections at University Emergency Hospital Bucharest, Ophthalmology department between January 2009 and September 2010 (Group A comprising of twenty patients had the coralline hydroxyapatite implant -Integrated Ocular Implants, USA and Group B comprising of twenty-three received non-integrated PMMA ocular implants) .The outcomes measured were the degree of exo /enophthalmos, horizontal eyelid fissure and palpebral fissure height at 4 years after surgical intervention related to measurement to the contralateral eye. Horizontal eyelid fissure (HEF) was suffering a shortening of 7.4% in the group B versus the contralateral eye, and only 1.9% in the group A related to the contralateral eye. Eyelid fissure height was greater in the group B with 5.2% regarding the contralateral eye, and 1.2% in group A. The degree of enophthalmia was higher in the group B of 4 mm versus the contralateral eye and lower in group A 1.5 mm regarding the contralateral eye. . Although a hydroxyapatite implant may be not as economic as a PMMA implant, a patient must be warned about the effect on its ocular structures in time and that cosmetic appearance over years will change more dramatically than in the fellow normal eye. Therefore preoperative counseling of the patient is crucial in long term patient satisfaction.

Mutation of SALL2 causes recessive ocular coloboma in humans and mice

PubMed Central

Kelberman, Daniel; Islam, Lily; Lakowski, Jörn; Bacchelli, Chiara; Chanudet, Estelle; Lescai, Francesco; Patel, Aara; Stupka, Elia; Buck, Anja; Wolf, Stephan; Beales, Philip L.; Jacques, Thomas S.; Bitner-Glindzicz, Maria; Liasis, Alki; Lehmann, Ordan J.; Kohlhase, Jürgen; Nischal, Ken K.; Sowden, Jane C.

2014-01-01

Ocular coloboma is a congenital defect resulting from failure of normal closure of the optic fissure during embryonic eye development. This birth defect causes childhood blindness worldwide, yet the genetic etiology is poorly understood. Here, we identified a novel homozygous mutation in the SALL2 gene in members of a consanguineous family affected with non-syndromic ocular coloboma variably affecting the iris and retina. This mutation, c.85G>T, introduces a premature termination codon (p.Glu29*) predicted to truncate the SALL2 protein so that it lacks three clusters of zinc-finger motifs that are essential for DNA-binding activity. This discovery identifies SALL2 as the third member of the Drosophila homeotic Spalt-like family of developmental transcription factor genes implicated in human disease. SALL2 is expressed in the developing human retina at the time of, and subsequent to, optic fissure closure. Analysis of Sall2-deficient mouse embryos revealed delayed apposition of the optic fissure margins and the persistence of an anterior retinal coloboma phenotype after birth. Sall2-deficient embryos displayed correct posterior closure toward the optic nerve head, and upon contact of the fissure margins, dissolution of the basal lamina occurred and PAX2, known to be critical for this process, was expressed normally. Anterior closure was disrupted with the fissure margins failing to meet, or in some cases misaligning leading to a retinal lesion. These observations demonstrate, for the first time, a role for SALL2 in eye morphogenesis and that loss of function of the gene causes ocular coloboma in humans and mice. PMID:24412933

Closure of the middle ear with special reference to the development of the tegmen tympani of the temporal bone

PubMed Central

Rodríguez-Vázquez, José Francisco; Murakami, Gen; Verdugo-López, Samuel; Abe, Shin-ichi; Fujimiya, Mineko

2011-01-01

Closure of the middle ear is believed to be closely related to the evolutionary development of the mammalian jaw. However, few comprehensive descriptions are available on fetal development. We examined paraffin-embedded specimens of 20 mid-term human fetuses at 8–25 weeks of ovulation age (crown-rump length or CRL, 38–220 mm). After 9 weeks, the tympanic bone and the squamous part of the temporal bone, each of which was cranial or caudal to Meckel's cartilage, grew to close the lateral part of the tympanosquamosal fissure. At the same time, the cartilaginous tegmen tympani appeared independently of the petrous part of the temporal bone and resulted in the petrosquamosal fissure. Subsequently, the medial part of the tympanosquamosal fissure was closed by the descent of a cartilaginous inferior process of the tegmen tympani. When Meckel's cartilage changed into the sphenomandibular ligament and the anterior ligament of the malleus, the inferior process of the tegmen tympani interposed between the tympanic bone and the squamous part of the temporal bone, forming the petrotympanic fissure for the chorda tympani nerve and the discomalleolar ligament. Therefore, we hypothesize that, in accordance with the regression of Meckel's cartilage, the rapidly growing temporomandibular joint provided mechanical stress that accelerated the growth and descent of the inferior process of the tegmen tympani via the discomalleolar ligament. The usual diagram showing bony fissures around the tegmen tympani may overestimate the role of the tympanic bone in the fetal middle-ear closure. PMID:21477146

Modeling plaque fissuring and dissection during balloon angioplasty intervention.

PubMed

Gasser, T Christian; Holzapfel, Gerhard A

2007-05-01

Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and/or dissection occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment site. We propose physical and finite element models, which are generally useable to trace fissuring and/or dissection in atherosclerotic plaques during balloon angioplasty interventions. The arterial wall is described as an anisotropic, heterogeneous, highly deformable, nearly incompressible body, whereas tissue failure is captured by a strong discontinuity kinematics and a novel cohesive zone model. The numerical implementation is based on the partition of unity finite element method and the interface element method. The later is used to link together meshes of the different tissue components. The balloon angioplasty-based failure mechanisms are numerically studied in 3D by means of an atherosclerotic-prone human external iliac artery, with a type V lesion. Image-based 3D geometry is generated and tissue-specific material properties are considered. Numerical results show that in a primary phase the plaque fissures at both shoulders of the fibrous cap and stops at the lamina elastica interna. In a secondary phase, local dissections between the intima and the media develop at the fibrous cap location with the smallest thickness. The predicted results indicate that plaque fissuring and dissection cause localized mechanical trauma, but prevent the main portion of the stenosis from high stress, and hence from continuous tissue damage.

The temporal requirement for vitamin A in the developing eye: mechanism of action in optic fissure closure and new roles for the vitamin in regulating cell proliferation and adhesion in the embryonic retina.

PubMed

See, Angela Wai-Man; Clagett-Dame, Margaret

2009-01-01

Mammalian eye development requires vitamin A (retinol, ROL). The role of vitamin A at specific times during eye development was studied in rat fetuses made vitamin A deficient (VAD) after embryonic day (E) 10.5 (late VAD). The optic fissure does not close in late VAD embryos, and severe folding and collapse of the retina is observed at E18.5. Pitx2, a gene required for normal optic fissure closure, is dramatically downregulated in the periocular mesenchyme in late VAD embryos, and dissolution of the basal lamina does not occur at the optic fissure margin. The addition of ROL to late VAD embryos by E12.5 restores Pitx2 expression, supports dissolution of the basal lamina, and prevents coloboma, whereas supplementation at E13.5 does not. Surprisingly, ROL given as late as E13.5 completely prevents folding of the retina despite the presence of an open fetal fissure, showing that coloboma and retinal folding represent distinct VAD-dependent defects. Retinal folding due to VAD is preceded by an overall reduction in the percentage of cyclin D1 positive cells in the developing retina, (initially resulting in retinal thinning), as well as a dramatic reduction in the cell adhesion-related molecules, N-cadherin and beta-catenin. Reduction of retinal cell number combined with a loss of the normal cell-cell adhesion proteins may contribute to the collapse and folding of the retina that occurs in late VAD fetuses.

Anal self-massage in the treatment of acute anal fissure: a randomized prospective study.

PubMed

Gaj, Fabio; Biviano, Ivano; Candeloro, Laura; Andreuccetti, Jacopo

2017-01-01

An anal fissure (AF) is a tear in the epithelial lining of the anal canal. This is a very common condition, but the choice of treatment is unclear. The use of anal dilators is effective, economic, and safe. The aim of the study was to compare the efficacy of two conservative treatments, the use of anal dilators or a finger for anal dilatation, in reducing anal pressure and resolving anal fissures. Fifty patients with a clinical diagnosis of AF were randomly assigned to one of the treatments, self-massage of the anal sphincter (group A, 25 patients) or passive dilatation using dilators (group B, 25 patients). All patients were evaluated at baseline, at the end of treatment, and after 12 weeks and 6 months. Pain was measured using a visual analog scale. After the treatment, 60% of patients treated with dilators and 80% of patients treated with anal self-massage using a finger showed disappearance of their anal fissures. A comparison between signs and symptoms reported by the patients in the two groups showed a statistically significant reduction in anal pain (group A, P=0.0001; group B, P=0.0001) and bleeding after defecation (group A, P=0.001, group B, P=0.001). At 6 months after treatment, a significantly greater reduction in anal pain was observed in Group A compared to Group B (P=0.02). The use of anal self-massage with a finger appears to induce a better resolution of acute anal fissure than do anal dilators, and in a shorter time.

Early generation selection for rice fissure resistance proves effective and indicates a fissure resistance gene on chromsome 1

USDA-ARS?s Scientific Manuscript database

Whole rice kernels have two to three times more market value than brokens, which means that any reduction in milling yield results in financial losses for both rice producers and millers. One of the leading causes of reduced milling yield is exposure of the rice kernels to severe moisture changes b...

Treatment for anal fissure: Is there a safe option?

PubMed

Brady, Justin T; Althans, Alison R; Neupane, Ruel; Dosokey, Eslam M G; Jabir, Murad A; Reynolds, Harry L; Steele, Scott R; Stein, Sharon L

2017-10-01

Surgeons often approach anal fissure with chemical denervation (Botulinum toxin, BT) instead of initial lateral internal sphincterotomy (LIS) due to concerns for long-term incontinence. We evaluated the characteristics and outcomes of patients who received BT or LIS. We performed a retrospective chart review of patients undergoing LIS and BT for anal fissure between 2009 and 2015. In 2015, a telephone survey was performed to evaluate durability, long-term incontinence and patient satisfaction. Ninety-four patients met criteria: 73 LIS and 21 BT. Age (BT 49 vs. LIS 52) was similar between groups (p = 1.0). Cleveland Clinic Fecal Incontinence (CCFI) score pre-intervention was higher in BT than LIS patients (2.1 vs. 0.4, p = 0.007) with fewer BT patients with perfect continence (50% vs. 88%). Telephone survey response was 61%. Fissure recurrence was significantly higher for BT than LIS patients (36% vs. 9%, p = 0.03). Patients undergoing LIS were less likely to recur. Both LIS and BT patients had some durable changes in continence raising the question of whether there is a safe technique. Copyright © 2017 Elsevier Inc. All rights reserved.

Propagation of dikes at Vesuvio (Italy) and the effect of Mt. Somma

NASA Astrophysics Data System (ADS)

Acocella, V.; Porreca, M.; Neri, M.; Massimi, E.; Mattei, M.

2006-04-01

Dikes provide crucial information on how magma propagates within volcanoes. Somma-Vesuvio (Italy) consists of the active Vesuvio cone, partly bordered by the older Mt. Somma edifice. Historical chronicles on the fissure eruptions in 1694-1944 are matched with an analytical solution to define the propagation path of the related dikes and to study any control of the Mt. Somma relief. The fissures always consisted of the downslope migration of vents from an open summit conduit, indicating lateral propagation as the predominant mechanism for shallow dike emplacement. No fissure emplaced beyond Mt. Somma, suggesting that its buttressing hinders the propagation of the radial dikes. An analytical solution is defined to describe the mechanism of formation of the laterally propagating dikes and to evaluate the effect of topography. The application to Somma-Vesuvio suggests that, under ordinary excess magmatic pressures, the dikes should not propagate laterally at depths >240-480 m below the surface, as the increased lithostatic pressure requires magmatic pressures higher than average. This implies that, when the conduit is open, the lateral emplacement of dikes is expectable on the S, W and E slopes. The lack of fissures N of Mt. Somma is explained by its buttressing, which hinders dike propagation.

Soil gas geochemistry in relation to eruptive fissures on Timanfaya volcano, Lanzarote Island (Canary Islands, Spain)

NASA Astrophysics Data System (ADS)

Padrón, Eleazar; Padilla, Germán; Hernández, Pedro A.; Pérez, Nemesio M.; Calvo, David; Nolasco, Dácil; Barrancos, José; Melián, Gladys V.; Dionis, Samara; Rodríguez, Fátima

2013-01-01

We report herein the first results of an extensive soil gas survey performed on Timanfaya volcano on May 2011. Soil gas composition at Timanfaya volcano indicates a main atmospheric source, slightly enriched in CO2 and He. Soil CO2 concentration showed a very slight deep contribution of the Timanfaya volcanic system, with no clear relation to the main eruptive fissures of the studied area. The existence of soil helium enrichments in Timanfaya indicates a shallow degassing of crustal helium and other possible deeper sources probably form cooling magma bodies at depth. The main soil helium enrichments were observed in good agreement with the main eruptive fissures of the 1730-36 eruption, with the highest values located at those areas with a higher density of recent eruptive centers, indicating an important structural control for the leakage of helium at Timanfaya volcano. Atmospheric air slightly polluted by deep-seated helium emissions, CO2 degassed from a cooling magma body, and biogenic CO2, might be the most plausible explanation for the existence of soil gas. Helium is a deep-seated gas, exhibiting important emission rates along the main eruptive fissure of the 1730-36 eruption of Timanfaya volcano.

River of Sand

NASA Image and Video Library

2016-09-21

A dominant driver of surface processes on Mars today is aeolian (wind) activity. In many cases, sediment from this activity is trapped in low-lying areas, such as craters. Aeolian features in the form of dunes and ripples can occur in many places on Mars depending upon regional wind regimes. The Cerberus Fossae are a series of discontinuous fissures along dusty plains in the southeastern region of Elysium Planitia. This rift zone is thought to be the result of combined volcano-tectonic processes. Dark sediment has accumulated in areas along the floor of these fissures as well as inactive ripple-like aeolian bedforms known as "transverse aeolian ridges" (TAR). Viewed through HiRISE infrared color, the basaltic sand lining the fissures' floor stands out as deep blue against the light-toned dust covering the region. This, along with the linearity of the fissures and the wave-like appearance of the TAR, give the viewer an impression of a river cutting through the Martian plains. However, this river of sand does not appear to be flowing. Analyses of annual monitoring images of this region have not detected aeolian activity in the form of ripple migration thus far. http://photojournal.jpl.nasa.gov/catalog/PIA21063

Underclad cracking of pressure vessel steels for light-water reactors

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

Lopez, H.F.

1987-06-01

Although fracture mechanics analyses have shown that underclad cracks have no detrimental effect on the integrity of thick walled pressure vessels (40 year service), in order to avoid unexpected failures the US Nuclear Regulatory Commission has issued Regulatory Guide 1.43 which sets limits on the extent of fissures permitted and describes acceptable means of controlling the weld cladding processes. Cavitation and intergranular fissuring in SA508-2 and 22NiMoCr37 steels can occur in the presence or absence of intergranular particles. The observations of intergranular fissuring and cavitation in those HAZ free from overlapping effects are attributed to grain boundary segregation. Other probablemore » void nucleation sites are the grain boundary-lath interface intersections which facilitate the formation of grain boundary discontinuities.« less

Low intensity hawaiian fountaining as exemplified by the March 2011, Kamoamoa eruption at Kilauea Volcano, Hawai`i (Invited)

NASA Astrophysics Data System (ADS)

Orr, T. R.; Houghton, B. F.; Poland, M. P.; Patrick, M. R.; Thelen, W. A.; Sutton, A. J.; Parcheta, C. E.; Thornber, C. R.

2013-12-01

The latest 'classic' hawaiian high-fountaining activity at Kilauea Volcano occurred in 1983-1986 with construction of the Pu`u `O`o pyroclastic cone. Since then, eruptions at Kilauea have been dominated by nearly continuous effusive activity. Episodes of sustained low hawaiian fountaining have occurred but are rare and restricted to short-lived fissure eruptions along Kilauea's east rift zone. The most recent of these weakly explosive fissure eruptions--the Kamoamoa eruption--occurred 5-9 March 2011. The Kamoamoa eruption was probably the consequence of a decrease in the carrying capacity of the conduit feeding the episode 58 eruptive vent down-rift from Pu`u `O`o in Kilauea's east rift zone. As output from the vent waned, Kilauea's summit magma storage and east rift zone transport system began to pressurize, as manifested by an increase in seismicity along the upper east rift zone, inflation of the summit and Pu`u `O`o, expansion of the east rift zone, and rising lava levels at both the summit and Pu`u `O`o. A dike began propagating towards the surface from beneath Makaopuhi Crater, 6 km west of Pu`u `O`o, at 1342 Hawaiian Standard Time (UTC - 10 hours) on 5 March. A fissure eruption started about 3.5 hours later near Nāpau Crater, 2 km uprift of Pu`u `O`o. Activity initially jumped between numerous en echelon fissure segments before centering on discrete vents near both ends of the 2.4-km-long fissure system for the final two days of the eruption. About 2.6 mcm of lava was erupted over the course of four days with a peak eruption rate of 11 m3/s. The petrologic characteristics of the fissure-fed lava indicate mixing between hotter mantle-derived magma and cooler rift-stored magma, with a greater proportion of the cooler component than was present in east rift zone lava erupting before March 2011. The fissure eruption was accompanied by the highest SO2 emission rates since 1986. Coincidentally, the summit and Pu`u `O`o deflated as magma drained away, causing expansion of the ERZ. The geological, geophysical, and geochemical datasets collected before, during, and after the Kamoamoa eruption provide an unprecedented account of what, at least in recent decades, is the 'normal' mode for hawaiian fountaining at Kilauea--that is, low intensity fissure-fed eruptions. This activity differs from high fountaining in that there is little physical coupling between melt and magmatic gas--for much of the Kamoamoa eruption lava ponded sluggishly over the vents and was weakly disrupted by bursts from trains of very closely spaced gas bubbles. Such eruptions enable us to examine the middle ground between strombolian and classical hawaiian behaviors at basaltic volcanoes.

Surface Deformation Associated With a Historical Diking Event in Afar From Correlation of Space and Air-Borne Optical Images

NASA Astrophysics Data System (ADS)

Harrington, J.; Peltzer, G.; Leprince, S.; Ayoub, F.; Kasser, M.

2011-12-01

We present new measurements of the surface deformation associated with the rifting event of 1978 in the Asal-Ghoubbet rift, Republic of Djibouti. The Asal-Ghoubbet rift forms a component of the Afar Depression, a broad extensional region at the junction between the Nubia, Arabia, and Somalia plates, which apart from Iceland, is the only spreading center located above sea-level. The 1978 rifting event was marked by a 2-month sequence of small to moderate earthquakes (Mb ~3-5) and a fissural eruption of the Ardukoba Volcano. Deformation in the Asal rift associated with the event included the reactivation of the main bordering faults and the development of numerous open fissures on the rift floor. The movement of the rift shoulders, measured using ground-based geodesy, showed up to 2.5 m of opening in the N40E direction. Our data include historical aerial photographs from 1962 and 1984 (less than 0.8 m/pixel) along the northern border fault, three KH-9 Hexagon(~8 m/pixel) satellite images from 1973, and recently acquired ASTER (15 m/pixel) and SPOT5 (2.5 m/pixel) data. The measurements are made by correlating pre- and post-event images using the COSI-Corr (Co-registration of Optically Sensed Images and Correlation) software developed at Caltech. The ortho-rectification of the images is done with a mosaic of a 10 m resolution digital elevation model, made by French Institut Geographique National (IGN), and the SRTM and GDEM datasets. Correlation results from the satellite images indicate 2-3 meters of opening across the rift. Preliminary results obtained using the 1962 and 1984 aerial photographs indicate that a large fraction of the opening occurred on or near Fault γ, which borders the rift to the North. These preliminary results are largely consistent with the ground based measurements made after the event. A complete analysis of the aerial photograph coverage will provide a better characterization of the spatial distribution of the deformation throughout the rift.

Anorectal pain and irritation: anal fissure, levator syndrome, proctalgia fugax, and pruritus ani.

PubMed

Vincent, C

1999-03-01

Anal fissures, proctalgia fugax, levator ani syndrome, and pruritus ani are common causes of anorectal pain and irritation. The clinician who obtains a thorough history and performs a complete examination can accurately diagnose these disorders. Ancillary tests seldom are helpful and rarely are necessary. Most patients suffering from these conditions readily respond to conservative therapy provided in the primary care practitioner's office.

Volcanic Eruptions of the EPR and Ridge Axis Segmentation: An Interdisciplinary View

NASA Astrophysics Data System (ADS)

White, S.; Soule, S. A.; Tolstoy, M.; Waldhauser, F.; Rubin, K.

2008-12-01

The eruption of the EPR in 2005-06 provides an ideal window into the relationship between fine-scale segmentation of the ridge axis and individual eruptive episodes. Lava flow mapping of the eruption by visual and acoustic images, precise dates on multiple eruptive units, stress information from seismicity, long-term records of hydrothermal activity, and well known segment boundaries illustrate the relationships between eruptions and segmentation of mid-ocean ridges. Lava flows emerged from several sections of the axial summit trough (AST) during the eruption, presumably from en echelon fissures between 9 45'N and 9 57'N. Each en echelon fissure is a 4th order segment, and the overall area matches the 3rd Order segment between ~9 45'N and ~9 58'N. Within the eruption, the primary eruptive fissure jumped east by 600 m at 9 53'N, and ran along an inward facing fault scarp, although limited lava effusion also extended northward along the axial fissure. A zone of high seismicity connects the normal fault bounding the eastern fissure eruption with the main locus of eruption on the ridge axis to the south, suggesting that the offset eruption may have occurred in response to stress buildup on this fault. Radiometric ages indicate that the entire along-axis extent of the eruptive fissures activated initially, but that volcanic activity focused to a single fourth-order segment within 1-3 months. Previously indentified breaks in the AST and its overall outline were largely unchanged by the eruption. These observations support the hypothesis that fourth-order segments are offsets controlled by the mechanics of dike emplacement, whereas third-order segments represent discrete volcanic systems. Dike segmentation may be controlled by variations in underlying ridge structure or the magma reservoir. Hydrothermal systems disrupted as far south as 9 37'N may be responding to cracking due to stress interaction or share a common deeper magmatic source. Comparisons between the 1991 EPR eruption at the same site, and several mapped southern EPR eruptions, the 10 45'N EPR eruption in ca. 2003 all show similar relationships to segmentation

Evaluation of different types of enamel conditioning before application of a fissure sealant.

PubMed

Ciucchi, Philip; Neuhaus, Klaus W; Emerich, Marta; Peutzfeldt, Anne; Lussi, Adrian

2015-01-01

The aim of the study was to compare fissure sealant quality after mechanical conditioning of erbium-doped yttrium aluminium garnet (Er:YAG) laser or air abrasion prior to chemical conditioning of phosphoric acid etching or of a self-etch adhesive. Twenty-five permanent molars were initially divided into three groups: control group (n = 5), phosphoric acid etching; test group 1 (n = 10), air abrasion; and test group 2, (n = 10) Er:YAG laser. After mechanical conditioning, the test group teeth were sectioned buccolingually and the occlusal surface of one half tooth (equal to one sample) was acid etched, while a self-etch adhesive was applied on the other half. The fissure system of each sample was sealed, thermo-cycled and immersed in 5% methylene dye for 24 h. Each sample was sectioned buccolingually, and one slice was analysed microscopically. Using specialized software microleakage, unfilled margin, sealant failure and unfilled area proportions were calculated. A nonparametric ANOVA model was applied to compare the Er:YAG treatment with that of air abrasion and the self-etch adhesive with phosphoric acid (α = 0.05). Test groups were compared to the control group using Wilcoxon rank sum tests (α = 0.05). The control group displayed significantly lower microleakage but higher unfilled area proportions than the Er:YAG laser + self-etch adhesive group and displayed significantly higher unfilled margin and unfilled area proportions than the air-abrasion + self-etch adhesive group. There was no statistically significant difference in the quality of sealants applied in fissures treated with either Er:YAG laser or air abrasion prior to phosphoric acid etching, nor in the quality of sealants applied in fissures treated with either self-etch adhesive or phosphoric acid following Er:YAG or air-abrasion treatment.

Tongue prints in biometric authentication: A pilot study

PubMed Central

Jeddy, Nadeem; Radhika, T; Nithya, S

2017-01-01

Background and Objectives: Biometric authentication is an important process for the identification and verification of individuals for security purposes. There are many biometric systems that are currently in use and also being researched. Tongue print is a new biometric authentication tool that is unique and cannot be easily forged because no two tongue prints are similar. The present study aims to evaluate the common morphological features of the tongue and its variations in males and females. The usefulness of alginate impression and dental cast in obtaining the lingual impression was also evaluated. Materials and Methods: The study sample included twenty participants. The participants were subjected to visual examination following which digital photographs of the dorsal surface of the tongue were taken. Alginate impressions of the tongue were made, and casts were prepared using dental stone. The photographs and the casts were analyzed by two observers separately for the surface morphology including shape, presence or absence of fissures and its pattern of distribution. Three reference points were considered to determine the shape of the tongue. Results: The most common morphological feature on the dorsum of the tongue was the presence of central fissures. Multiple vertical fissures were observed in males whereas single vertical fissure was a common finding in females. The fissures were predominantly shallow in males and deep in females. The tongue was predominantly U shaped in males and females. V-shaped tongue was observed in 25% of females. Conclusion: Tongue prints are useful in biometric authentication. The methodology used in the study is simple, easy and can be adopted by dentists on a regular basis. However, large-scale studies are required to validate the results and also identify other features of the tongue that can be used in forensics and biometric authentication process. PMID:28479712

Tongue prints in biometric authentication: A pilot study.

PubMed

Jeddy, Nadeem; Radhika, T; Nithya, S

2017-01-01

Biometric authentication is an important process for the identification and verification of individuals for security purposes. There are many biometric systems that are currently in use and also being researched. Tongue print is a new biometric authentication tool that is unique and cannot be easily forged because no two tongue prints are similar. The present study aims to evaluate the common morphological features of the tongue and its variations in males and females. The usefulness of alginate impression and dental cast in obtaining the lingual impression was also evaluated. The study sample included twenty participants. The participants were subjected to visual examination following which digital photographs of the dorsal surface of the tongue were taken. Alginate impressions of the tongue were made, and casts were prepared using dental stone. The photographs and the casts were analyzed by two observers separately for the surface morphology including shape, presence or absence of fissures and its pattern of distribution. Three reference points were considered to determine the shape of the tongue. The most common morphological feature on the dorsum of the tongue was the presence of central fissures. Multiple vertical fissures were observed in males whereas single vertical fissure was a common finding in females. The fissures were predominantly shallow in males and deep in females. The tongue was predominantly U shaped in males and females. V-shaped tongue was observed in 25% of females. Tongue prints are useful in biometric authentication. The methodology used in the study is simple, easy and can be adopted by dentists on a regular basis. However, large-scale studies are required to validate the results and also identify other features of the tongue that can be used in forensics and biometric authentication process.

Randomized clinical trial assessing the side-effects of glyceryl trinitrate and diltiazem hydrochloride in the treatment of chronic anal fissure.

PubMed

Kocher, H M; Steward, M; Leather, A J M; Cullen, P T

2002-04-01

Glyceryl trinitrate (GTN) ointment (0 small middle dot2 per cent) has an efficacy of up to 68 per cent in healing chronic anal fissure, but with headache as a major side-effect. Diltiazem hydrochloride (DTZ) cream (2 per cent) is expected to have fewer side-effects. A prospective double-blind randomized two-centre trial requiring at least 26 patients in each group (alpha = 0.05, beta = 0.9) was instituted after approval of the local ethics committee, to compare the incidence of side-effects (primary endpoint) with 0.2 per cent GTN ointment and 2 per cent DTZ cream in the treatment of chronic anal fissure. Treatments were applied perianally, twice daily for 6-8 weeks. All patients gave written informed consent. Both groups were comparable in patient demographics and clinical characteristics. Twelve patients violated the protocol, withdrew or did not attend follow-up. There were more side-effects with GTN (21 of 29 patients) than with DTZ (13 of 31) (relative risk (RR) 1.84 (95 per cent confidence interval (c.i.) 1.11 to 3.04), P = 0.01). In particular, more headaches occurred with GTN (17 of 29 patients) than with DTZ (eight of 31) (RR 2.06 (95 per cent c.i. 1.18 to 3.59), P = 0.01). There were no significant differences in healing and symptomatic improvement rates between patients receiving GTN (25 of 29) and DTZ (24 of 31). DTZ cream caused substantially fewer headaches than GTN ointment. There was no significant difference in the healing or improvement of chronic anal fissure between the treatments. DTZ may be the preferred first-line treatment for chronic anal fissure.

Modeling of reservoir compaction and surface subsidence at South Belridge

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

Hansen, K.S.; Chan, C.K.; Prats, M.

1995-08-01

Finite-element models of depletion-induced reservoir compaction and surface subsidence have been calibrated with observed subsidence, locations of surface fissures, and regions of subsurface casing damage at South Belridge and used predictively for the evaluation of alternative reservoir-development plans. Pressure maintenance through diatomite waterflooding appears to be a beneficial means of minimizing additional subsidence and fissuring as well as reducing axial-compressive-type casing damage.

The role of faulting on surface deformation patterns from pumping-induced groundwater flow (Las Vegas Valley, USA)

NASA Astrophysics Data System (ADS)

Hernandez-Marin, Martin; Burbey, Thomas J.

2009-12-01

Land subsidence and earth fissuring can cause damage in semiarid urbanized valleys where pumping exceeds natural recharge. In places such as Las Vegas Valley (USA), Quaternary faults play an important role in the surface deformation patterns by constraining the migration of land subsidence and creating complex relationships with surface fissures. These fissures typically result from horizontal displacements that occur in zones where extensional stress derived from groundwater flow exceeds the tensile strength of the near-surface sediments. A series of hypothetical numerical models, using the finite-element code ABAQUS and based on the observed conditions of the Eglington Fault zone, were developed. The models reproduced the (1) long-term natural recharge and discharge, (2) heavy pumping and (3) incorporation of artificial recharge that reflects the conditions of Las Vegas Valley. The simulated hydrostratigraphy consists of three aquifers, two aquitards and a relatively dry vadose zone, plus a normal fault zone that reflects the Quaternary Eglington fault. Numerical results suggest that a 100-m-wide fault zone composed of sand-like material produces: (1) conditions most similar to those observed in Las Vegas Valley and (2) the most favorable conditions for the development of fissures to form on the surface adjacent to the fault zone.

Caries-preventive effect of fissure sealant containing surface reaction-type pre-reacted glass ionomer filler and bonded by self-etching primer.

PubMed

Shimazu, Kisaki; Ogata, Kiyokazu; Karibe, Hiroyuki

2012-01-01

We aimed to evaluate the caries-preventive effect of a fissure sealant containing surface reaction-type pre-reacted glass ionomer (S-PRG) filler and bonded by self-etching primer versus those of 2 conventional resin-based sealants bonded by acid etching in terms of its impact on enamel demineralization and remineralization, enamel bond strength, and integrity of debonded enamel surfaces. Demineralization, remineralization, and bond strength on untreated enamel and enamel subsurface lesions of bovine incisors were assessed among the sealants by polarizing microscopy and microradiography; debonded enamel surfaces were examined by scanning electron microscopy. The conventional resin-based sealants bonded by acid etching caused surface defects on the enamel subsurface lesions and significantly increased the lesion depth (p = 0.014), indicative of enamel demineralization. However the S-PRG filler-containing sealant bonded by self-etching primer maintained the enamel surface integrity and inhibited enamel demineralization. No difference in bond strength on both untreated enamel and enamel subsurface lesions was noted among the sealants. An S-PRG filler-containing fissure sealant bonded by self-etching primer can prevent enamel demineralization, microleakage, and gaps without the tags created by acid etching regardless of the enamel condition. Such sealants are suitable for protecting the pits and fissures of immature permanent teeth.

Anaplasic astrocytoma with exophytic growth in Sylvian fissure in a pediatric patient: a case report

PubMed Central

Bravo-Ángel, Ulises; Hernández-Reséndiz, Rodrigo Efraín; Vicuña-González, Rosa María; Frías-Guillén, Jessica; Bercholc-Urinowsky, Irina Jeanette; Bravo-Reyna, Carlos Cesar; García-González, Ulises

2018-01-01

Abstract Gliomas are the most frequent supratentorial intracranial tumors in the pediatric population. Usually, they are intra-axial lesions with a characteristic image pattern, however, there are few reported cases of gliomas with exophytic growth. There are no previous reports in the literature of gliomas with exophytic growth in the Sylvian fissure. Fourteen year-old female patient who started with seizures. In imaging studies, a neoplasic mass with an exophytic portion in the left Sylvian fissure was found. Macroscopically, total resection was performed, definitive diagnosis was anaplastic astrocytoma. She presented recurrence and is currently receiving adjuvant treatment. Supratentorial gliomas with exophytic growth are extremely rare. We report the first case in the pediatric population, and we consider it is important to know its imaging and macroscopic characteristics for its initial management and to take it into account as a differential diagnosis of exophytic lesions. PMID:29732137

Anaplasic astrocytoma with exophytic growth in Sylvian fissure in a pediatric patient: a case report.

PubMed

Guerra-Mora, José Raúl; Bravo-Ángel, Ulises; Hernández-Reséndiz, Rodrigo Efraín; Vicuña-González, Rosa María; Frías-Guillén, Jessica; Bercholc-Urinowsky, Irina Jeanette; Bravo-Reyna, Carlos Cesar; García-González, Ulises

2018-04-01

Gliomas are the most frequent supratentorial intracranial tumors in the pediatric population. Usually, they are intra-axial lesions with a characteristic image pattern, however, there are few reported cases of gliomas with exophytic growth. There are no previous reports in the literature of gliomas with exophytic growth in the Sylvian fissure. Fourteen year-old female patient who started with seizures. In imaging studies, a neoplasic mass with an exophytic portion in the left Sylvian fissure was found. Macroscopically, total resection was performed, definitive diagnosis was anaplastic astrocytoma. She presented recurrence and is currently receiving adjuvant treatment. Supratentorial gliomas with exophytic growth are extremely rare. We report the first case in the pediatric population, and we consider it is important to know its imaging and macroscopic characteristics for its initial management and to take it into account as a differential diagnosis of exophytic lesions.

Flows of Newtonian and Power-Law Fluids in Symmetrically Corrugated Cappilary Fissures and Tubes

NASA Astrophysics Data System (ADS)

Walicka, A.

2018-02-01

In this paper, an analytical method for deriving the relationships between the pressure drop and the volumetric flow rate in laminar flow regimes of Newtonian and power-law fluids through symmetrically corrugated capillary fissures and tubes is presented. This method, which is general with regard to fluid and capillary shape, can also be used as a foundation for different fluids, fissures and tubes. It can also be a good base for numerical integration when analytical expressions are hard to obtain due to mathematical complexities. Five converging-diverging or diverging-converging geometrics, viz. wedge and cone, parabolic, hyperbolic, hyperbolic cosine and cosine curve, are used as examples to illustrate the application of this method. For the wedge and cone geometry the present results for the power-law fluid were compared with the results obtained by another method; this comparison indicates a good compatibility between both the results.

Lung lobe modeling and segmentation with individualized surface meshes

NASA Astrophysics Data System (ADS)

Blaffert, Thomas; Barschdorf, Hans; von Berg, Jens; Dries, Sebastian; Franz, Astrid; Klinder, Tobias; Lorenz, Cristian; Renisch, Steffen; Wiemker, Rafael

2008-03-01

An automated segmentation of lung lobes in thoracic CT images is of interest for various diagnostic purposes like the quantification of emphysema or the localization of tumors within the lung. Although the separating lung fissures are visible in modern multi-slice CT-scanners, their contrast in the CT-image often does not separate the lobes completely. This makes it impossible to build a reliable segmentation algorithm without additional information. Our approach uses general anatomical knowledge represented in a geometrical mesh model to construct a robust lobe segmentation, which even gives reasonable estimates of lobe volumes if fissures are not visible at all. The paper describes the generation of the lung model mesh including lobes by an average volume model, its adaptation to individual patient data using a special fissure feature image, and a performance evaluation over a test data set showing an average segmentation accuracy of 1 to 3 mm.

Ground Subsidence Monitoring with MT-InSAR and Mechanism Inversion Over Xi'an, China

NASA Astrophysics Data System (ADS)

Peng, M. M.; Zhao, C. Y.; Zhang, Q.; Zhang, J.; Liu, Y. Y.

2018-04-01

The ancient Xi'an, China, has been suffering severe land subsidence and ground fissure hazards since the 1960s, which has affected the safety of Subways. Multi-sensor SAR data are conducted to monitor the latest complex ground deformation and its influence on subway line No.3 over Xi'an. Annual deformation rates have been retrieved to reveal the spatiotemporal evolution of ground subsidence in Xi'an city from 2013 to 2017. Meanwhile, the correlation between land subsidence and ground fissures are analyzed by retrieving the deformation differences in both sides of the fissures. Besides, the deformation along subway line No. 3 is analyzed, and the fast deformation section is quantitatively studied. Finally, a flat lying sill model with distributed contractions is implemented to model the InSAR deformation over YHZ subsidence center, which manifests that the ground deformation is mainly caused by groundwater withdrawal.

Simulation of the Flow Through Porous Layers Composed of Converging-Diverging Capillary Fissures or Tubes

NASA Astrophysics Data System (ADS)

Walicka, A.

2018-02-01

In this paper, a porous medium is modelled by a network of converging-diverging capillaries which may be considered as fissures or tubes. This model makes it necessary to consider flows through capillary fissures or tubes. Therefore an analytical method for deriving the relationships between pressure drops, volumetric flow rates and velocities for the following fluids: Newtonian, polar, power-law, pseudoplastic (DeHaven and Sisko types) and Shulmanian, was developed. Next, considerations on the models of pore network for Newtonian and non-Newtonian fluids were presented. The models, similar to the schemes of central finite differences may provide a good basis for transforming the governing equations of a flow through the porous medium into a set of linear or quasi-linear algebraic equations. It was shown that the some coefficients in these algebraic equations depend on the kind of the capillary convergence.

Genotyping in 46 patients with tentative diagnosis of Treacher Collins syndrome revealed unexpected phenotypic variation.

PubMed

Teber, Ozge Altug; Gillessen-Kaesbach, Gabriele; Fischer, Sven; Böhringer, Stefan; Albrecht, Beate; Albert, Angelika; Arslan-Kirchner, Mine; Haan, Eric; Hagedorn-Greiwe, Monika; Hammans, Christof; Henn, Wolfram; Hinkel, Georg Klaus; König, Rainer; Kunstmann, Erdmute; Kunze, Jürgen; Neumann, Luitgard M; Prott, Eva-Christina; Rauch, Anita; Rott, Hans-Dieter; Seidel, Heide; Spranger, Stephanie; Sprengel, Martin; Zoll, Barbara; Lohmann, Dietmar R; Wieczorek, Dagmar

2004-11-01

To define the range of phenotypic expression in Treacher Collins syndrome (TCS; Franceschetti-Klein syndrome), we performed mutation analysis in the TCOF1 gene in 46 patients with tentative diagnosis of TCS and evaluated the clinical data, including a scoring system. A total of 27 coding exons of TCOF1 and adjacent splice junctions were analysed by direct sequencing. In 36 patients with a clinically unequivocal diagnosis of TCS, we detected 28 pathogenic mutations, including 25 novel alterations. No mutation was identified in the remaining eight patients with unequivocal diagnosis of TCS and 10 further patients, in whom the referring diagnosis of TCS was clinically doubtful. There is no overt genotype-phenotype correlation except that conductive deafness is significantly less frequent in patients with mutations in the 3' part of the open reading frame. Inter- and intrafamilial variation is wide. Some mutation carriers, parents of typically affected patients, are so mildly affected that the diagnosis might be overlooked clinically. This suggests that modifying factors are important for phenotypic expression. Based on these findings, minimal diagnostic criteria were defined: downward slanting palpebral fissures and hypoplasia of the zygomatic arch. The difficulties in genetic counselling, especially diagnosis of family members with a mild phenotype, are described.

Review: Groundwater development and management in the Deccan Traps (basalts) of western India

NASA Astrophysics Data System (ADS)

Limaye, Shrikant Daji

2010-05-01

The Deccan Traps or the basalts of western India are the largest exposure of basic lava flows covering about 500,000 km2. Groundwater occurrence in the Deccan Traps is in phreatic condition in the weathered zone above the hard rock and in semi-confined condition in the fissures, fractures, joints, cooling cracks, lava flow junctions and in the inter-trappean beds between successive lava flows, within the hard rock. Dug wells, dug-cum-bored wells and boreholes or bore wells are commonly used for obtaining groundwater. The yield is small, usually in the range of 1-100 m3/day. The average land holding per farming family is only around 2 ha. Recently, due to the ever increasing number of dug wells and deep bore wells, the water table has been falling in several watersheds, especially in those lying in the semi-arid region of the traps, so that now the emphasis has shifted from development to sustainable management. Issues like climatic change, poverty mitigation in villages, sustainable development, rapid urbanization of the population, and resource pollution have invited the attention of politicians, policy makers, government agencies and non-governmental organizations towards watershed management, forestation, soil and water conservation, recharge augmentation and, above all, the voluntary control of groundwater abstraction in the Deccan Traps terrain.

Fissureless fissure-last video-assisted thoracoscopic lobectomy for all lung lobes: a better alternative to decrease the incidence of prolonged air leak?

PubMed

Stamenovic, Davor; Bostanci, Korkut; Messerschmidt, Antje; Jahn, Tillmann; Schneider, Thomas

2016-07-01

Prolonged air leak (PAL) after major lung resections is a common postoperative complication that leads to extended length of hospital stay (LOS) and increased hospital costs. Dissection of the lung tissue through the fissure may increase the incidence of PAL especially in the patients with incomplete fissures. The objective of this study was to evaluate the impact of the fissureless fissure-last technique in VATS lobectomy on immediate outcome, especially relating to air leak and LOS. This is an observational analysis on prospectively collected data of a single thoracic surgery unit. A total of 54 consecutive patients underwent VATS lobectomy and mediastinal lymphadenectomy-in 24 patients conventional VATS lobectomy (Group 1), in 30 patients fissureless VATS lobectomy (Group 2) was performed. The two groups were compared according to preoperative, operative and postoperative parameters. No differences were found when comparing patient characteristics, operation time (M1 = 185 min; M2 = 176 min; P = 0.52) and number of staplers used (M1 = 6.2; M2 = 7.7; P = 0.088). The presence of air leak (P = 0.004; RR = 3.5), PAL (P = 0.003; RR = 10), in days with chest tube (M1 = 7.2; M2 = 4.2; P = 0.028) and LOS (M1 = 12.7; M2 = 8.9; P = 0.020) was significantly more frequent in patients that underwent conventional VATS lobectomy. Focusing on the air leak, significance was present in male gender (P = 0.034; RR = 2.41), higher ASA (M1 = 3.04; M2 = 2.67; P = 0.012), postoperative complications other than air leak (P = 0.001; RR = 5.78) and age between groups with and without air leak (M1 = 63.9; M2 = 74.1; P < 0.001). Fissureless fissure-last VATS lobectomy is a feasible and equivalent to conventional VATS lobectomy in terms of operation time, stapler use and complications. Fissureless fissure-last VATS lobectomy, however, appears to be a superior technique to conventional VATS lobectomy in terms of preventing PAL and reducing the LOS. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Very-low-frequency resistivity, self-potential and ground temperature surveys on Taal volcano (Philippines): Implications for future activity

NASA Astrophysics Data System (ADS)

Zlotnicki, J.; Vargemezis, G.; Johnston, M. J. S.; Sasai, Y.; Reniva, P.; Alanis, P.

2017-06-01

Taal volcano is one of the most dangerous volcanoes in the Philippines. Thirty-three eruptions have occurred through historical time with several exhibiting cataclysmic phases. Most recent eruptions are confined to Volcano Island located within the prehistoric Taal collapse caldera that is now filled by Taal Lake. The last eruptive activity from 1965 to 1977 took place from Mt. Tabaro, about 2 km to the southwest of the Main Crater center. Since this time, episodes of seismic activity, ground deformation, gas release, surface fissuring, fumarole activity and temperature changes are recorded periodically around the main crater, but no major eruption has occurred. This period of quiescence is the third longest period without eruptive activity since 1572. In March 2010, a campaign based on Very-Low-Frequency (VLF) resistivity surveys together with repeated surveys of self-potential, ground temperature and fissure activity was intensified and the results compared to a large-scale Electrical Resistivity Tomography experiment. This work fortunately occurred before, within and after a new seismovolcanic crisis from late April 2010 to March 2011. The joint analysis of these new data, together with results from previous magnetotelluric soundings, allows a better description of the electrical resistivity and crustal structure beneath the Main Crater down to a depth of several kilometers. No indication of growth of the two geothermal areas located on both sides of the northern crater rim was apparent from 2005 to March 2010. These areas appear controlled by active fissures, opened during the 1992 and 1994 crises, that dip downward towards the core of the hydrothermal system located at about 2.5 km depth beneath the crater. Older mineralized fissures at lower elevations to the North of the geothermal areas also dip downward under the crater. Repeated self-potential and ground temperature surveys completed between 2005 and 2015 show new geothermal and hydrothermal activity in the areas of these older mineralized fissures that occurred during the April 2010 to March 2011 seismovolcanic crisis. This dramatically extends the geothermal activity further to the North on the volcano. The occurrence of these newly activated fissures after a long period of quiescence and indications of inflation in mid-2010 under the North rim of the Main Crater suggests that new eruptive activity near the North rim of the crater could occur in the future.

[Acute anal pain].

PubMed

Pittet, Olivier; Demartines, Nicolas; Hahnloser, Dieter

2013-07-01

Acute anal pain is a common proctological problem. A detailed history together with the clinical examination are crucial for the diagnosis. An acute perianal vein thrombosis can be successfully excised within the first 72 hours. Acute anal fissures are best treated conservatively using stool regulation and topical medications reducing the sphincter spasm. A chronic anal fissure needs surgery. Perianal abscesses can very often be incised and drained in local anesthesia. Proctalgia fugax and the levator ani syndrome are exclusion diagnoses and are treated symptomatically.

Artificial recharge through a well in fissured carbonate rock, west St. Paul, Minnesota

USGS Publications Warehouse

Reeder, Harold O.; Wood, Warren W.; Ehrlich, G.G.; Sun, Ren Jen

1976-01-01

The injection test demonstrated that it is hydrologically feasible to recharge the Prairie du Chien Group and the Jordan Sandstone artificially through wells completed in the Prairie du Chien Group. The fissures in the Prairie du Chien Group act as conduits through which water spreads. The water passes into the Jordan Sandstone from the Prairie du Chien over a larger area than it would if it were injected directly into the Jordan.

East Pacific rise at 21°N: the volcanic, tectonic, and hydrothermal processes of the central axis

USGS Publications Warehouse

Ballard, Richard D.; Francheteau, Jean; Juteau, Tierre; Rangan, Claude; Normark, William

1981-01-01

Photographs obtained by the ANGUS survey system at 21°N reveal many similarities to the geological processes delineated at other spreading centers and in particular those observed in the Galapagos Rift at 86°W. The region of recent volcanism is restricted to a narrow zone (Zone 1) approximately 1 km wide. This suggests that the width of the magma chamber feeding these flows is also narrow at the top. Variations in sediment cover are used to subdivide the flows within Zone 1 into three sheet-flow/pillow-flow pairs. The youngest pair appears to have erupted form a linear fissure 8 km long running parallel to the valley axis. This fissure is part of a larger en echelon pattern of eruptive fissures. Active hydrothermal vents associated with the youngest flows are situated directly above the apparent eruptive fissure. The high (350°C) temperature for some of the fluids exiting from the vents suggests a highly restricted circulation system involving, at times, little to no mixing with cold seawater. The lava terrain in the remainder of Zone 1 and bordering regions is characterized by extensive fracturing, further suggesting a narrow upper dimension to the magma chamber and also that subsurface hydrothermal deposition of massive sulfides may lead to a reduction in the mixing processes.

East Pacific Rise at 21 °N: The volcanic, tectonic, and hydrothermal processes of the central axis

USGS Publications Warehouse

Ballard, Richard D.; Francheteau, Jean; Juteau, Tierre; Rangan, Claude; Normark, William R.

1981-01-01

Photographs obtained by the ANGUS survey system at 21°N reveal many similarities to the geological processes delineated at other spreading centers and in particular those observed in the Galapagos Rift at 86°W. The region of recent volcanism is restricted to a narrow zone (Zone l) approximately l km wide. This suggests that the width of the magma chamber feeding these flows is also narrow at the top. Variations in sediment cover are used to subdivide the flows within Zone 1 into three sheet-flow/pillow-flow pairs. The youngest pair appears to have erupted form a linear fissure 8 km long running parallel to the valley axis. This fissure is part of a larger en echelon pattern of eruptive fissures. Active hydrothermal vents associated with the youngest flows are situated directly above the apparent eruptive fissure. The high (350°C) temperature for some of the fluids exiting from the vents suggests a highly restricted circulation system involving, at times, little to no mixing with cold seawater. The lava terrain in the remainder of Zone l and bordering regions is characterized by extensive fracturing, further suggesting a narrow upper dimension to the magma chamber and also that subsurface hydrothermal deposition of massive sulfides may lead to a reduction in the mixing processes.

Parents' Attitude towards the Use of Fluorides and Fissure Sealants and its Effect on their Children's Oral Health.

PubMed

Blumer, Sigalit; Ratson, Tal; Peretz, Benjamin; Dagon, Nurit

To characterize the attitudes of Israeli parents towards caries preventive measures. participating parents completed a 21-item questionnaire on their demographics, dental history, attitudes and satisfaction from fluorides and fissure sealants. One hundred parents (average age 41.62±4.9 years, 85 females) participated. Most of the parents (88% of the mothers and 84% of the fathers) had an academic education. Most of the parents (54%) had a favorable attitude towards the use of fluoridated gels, while only 37% of them had a positive opinion regarding fluoridated water. The satisfaction levels were very high regarding fissure sealants, fluoridated mouth rinses and fluoridated gels (78.1%, 73.6% and 72.5% respectively). The satisfaction from fluoridated water was split almost equally (50.8% were 'pleased' and 49.2% 'not pleased'). The main source for parental oral health knowledge was the dentist (83%). Parents' attitude towards caries preventive measures was significantly correlated to their gender, dental experience, level of education and the number of children in the family. positive attitude towards caries preventive measures was found among parents with higher awareness for preventive oral health measures and among bigger families. Mothers were more positive about fissure sealants than fathers. Mothers with up to 12 years of education tended to have a positive opinion regarding water fluoridation.

A comparative study of fissure sealants Helioseal Clear Chroma and Delton FS(+): 3 year results.

PubMed

Kargul, B; Tanboga, I; Gulman, N

2009-12-01

To evaluate the retention rates of a resin based colour changing fissure sealant (Helioseal Clear Chroma; Ivoclar Vivadent AG Schaan, Liechtenstein) compared with a coloured resin based fluoride fissure sealant (Delton FS(+); Dentsply De Trey GmbH,Konstanz,Germany). The fissure sealants (FS) were placed on all 4 caries-free first permanent molars of 31 children aged 6-9 years, using a half mouth experimental design by a paediatric dentist according to the manufacturers' instructions. A total of 121 FS were placed at baseline. Teeth were evaluated at 3 month intervals for 36 months where a preventive program including topical fluoride application was applied. Retention rates for 36 months showed a differences between Delton FS(+) and Helioseal Clear Chroma that were statistically significant (p<0.05). Delton FS(+) had total retention rate of 30.4% for 36 months compared with Helioseal Clear Chroma at 10.8% for the same evaluation period. Although Delton FS(+) showed significantly better results than Helioseal Clear Chroma for the evaluation periods, there were no statistically significant differences between Delton FS(+) (90.7%) and Helioseal Clear Chroma (80.4%) with respect to caries incidence at 36 months(p>0.05). Delton FS(+) showed a better complete retention rate for occlusal FS at one year. Both FS were aesthetically acceptable and easy to see during application and follow-up periods and gave significant protection from occlusal decay.

Endoscopic transmaxillary transMüller's muscle approach for decompression of superior orbital fissure: a cadaveric study with illustrative case.

PubMed

Wang, Xiang; Li, Yi-Ming; Huang, Cheng-Guang; Liu, Hong-Chao; Li, Qing-Chu; Yu, Ming-Kun; Hou, Li-Jun

2014-03-01

In an effort to avoid the damage and inconvenience associated with transcranial approaches, we developed an endoscopic transmaxillary transMüller's muscle approach for decompression of the superior orbital fissure (SOF). The endoscopic transmaxillary transMüller's muscle route was performed in ten cadaveric heads. We measured important anatomic landmarks, and angles radiographically. This approach was initially attempted in one patient with traumatic superior orbital fissure syndrome (tSOFS). A maxillary antrostomy was carried out with a buccal sulcus incision. The sinus ostium and the course of infraorbital nerve were used as endoscopic anatomic landmarks. Then the inferior orbital fissure was drilled out, followed by separating the Müller's muscle. The periorbita were peeled off from the lateral wall, followed by the endoscope going along the periorbital space, until the lateral aspect of the SOF could be visualized. Decompression was successfully performed in all specimens. The initial clinical application justified this approach. The patient had an uneventful postoperative course and satisfactory recovery. This approach offers sufficient endoscopic visualization and reliable decompression of SOF. It avoids the need for brain retraction, temporalis muscle manipulation, or any external incision, and appears to be able to deliver satisfying aesthetic results as well as favourable functional recovery. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

East Pacific rise at 21°N: The volcanic, tectonic, and hydrothermal processes of the central axis

NASA Astrophysics Data System (ADS)

Ballard, Robert D.; Francheteau, Jean; Juteau, Tierre; Rangan, Claude; Normark, William

1981-09-01

Photographs obtained by the ANGUS survey system at 21°N reveal many similarities to the geological processes delineated at other spreading centers and in particular those observed in the Galapagos Rift at 86°W. The region of recent volcanism is restricted to a narrow zone (Zone 1) approximately 1 km wide. This suggests that the width of the magma chamber feeding these flows is also narrow at the top. Variations in sediment cover are used to subdivide the flows within Zone 1 into three sheet-flow/pillow-flow pairs. The youngest pair appears to have erupted form a linear fissure 8 km long running parallel to the valley axis. This fissure is part of a larger en echelon pattern of eruptive fissures. Active hydrothermal vents associated with the youngest flows are situated directly above the apparent eruptive fissure. The high (350°C) temperature for some of the fluids exiting from the vents suggests a highly restricted circulation system involving, at times, little to no mixing with cold seawater. The lava terrain in the remainder of Zone 1 and bordering regions is characterized by extensive fracturing, further suggesting a narrow upper dimension to the magma chamber and also that subsurface hydrothermal deposition of massive sulfides may lead to a reduction in the mixing processes.

Spatially resolved near infrared observations of Enceladus' tiger stripe eruptions from Cassini VIMS

NASA Astrophysics Data System (ADS)

Dhingra, Deepak; Hedman, Matthew M.; Clark, Roger N.; Nicholson, Philip D.

2017-08-01

Particle properties of individual fissure eruptions within Enceladus' plume have been analyzed using high spatial resolution Visible and Infrared Mapping Spectrometer (VIMS) observations from the Cassini mission. To first order, the spectra of the materials emerging from Cairo, Baghdad and Damascus sulci are very similar, with a strong absorption band around 3 μm due to water-ice. The band minimum position indicates that the ice grains emerging from all the fissures are predominantly crystalline, which implies that the water-ice particles' formation temperatures are likely above 130 K. However, there is also evidence for subtle variations in the material emerging from the different source fissures. Variations in the spectral slope between 1-2.5 μm are observed and probably reflect differences in the size distributions of particles between 0.5 and 5 μm in radius. We also note variations in the shape of the 3 μm water-ice absorption band, which are consistent with differences in the relative abundance of > 5 μm particles. These differences in the particle size distribution likely reflect variations in the particle formation conditions and/or their transport within the fissures. These observations therefore provide strong motivation for detailed modeling to help place important constraints on the diversity of the sub-surface environmental conditions at the geologically active south-pole of Enceladus.

Spatial Variability in Enceladus' Plume Material Properties across Tiger Stripes: Observed Correlations and Implications

NASA Astrophysics Data System (ADS)

Dhingra, D.; Hedman, M. M.; Clark, R. N.; Postberg, F.

2016-12-01

The plume material emerging from Enceladus' south-pole has contributions from many sources distributed along four distinct fissures designated as Alexandria, Cairo, Baghdad and Damascus. In principle, the properties of the material escaping into the plume would depend upon the conditions within these individual fissures. Therefore, the particles emitted from different sources could have different properties. Indeed, observations made by the Visual and Infrared Mapping Spectrometer (VIMS) and Cosmic Dust Analyzer (CDA) instruments indicate differences in the water-ice grain sizes and abundance of organic-rich particles along the various fissures. These differences can be detected in both the plume surface deposits around the fissures [e.g. Brown et al., 2006; Jaumann et al, 2008] as well as in the active plume eruptions [Postberg et al., 2011; Dhingra et al., 2015, 2016]. Furthermore, these variations may represent systematic trends in particle size and organic content across the south polar terrain. We are analyzing these spatial correlations between different parameters and what they mean for the sub-surface environment in the active south polar terrain of Enceladus. Brown et al. (2006) Science, 311, 1425-1428Dhingra at al. (2015) 46th Lunar Planet. Sci. Conf., Abst#1648Dhingra et al. (2016) Icarus, under reviewJaumann et al. (2008) Icarus, 193, 407-419Postberg et al. (2011) Nature, 474, 620-622

Cerebellar foliation in rats. 2. Effects of maternal malnutrition on the formation of fissures in foetal rats.

PubMed

Conradi, N G; Müntzing, K

1985-11-01

The effects of maternal malnutrition on the formation of cerebellar fissures was studied in foetal rats. The rats were given a diet containing either 14 (normal) or 7 (protein-deprived) per cent protein by weight from two weeks before conception and throughout gestation. The first day with a sperm-positive vaginal smear was designated as Embryonic day 1 (E 1). Foetuses were examined on days E 19 to 22. In seventy-five foetuses, a sagittal slice of the cerebellum, 3-4 mm thick was embedded in Sorvall embedding medium. Sagittal sections, 2 micron thick were cut at levels 100 micron apart through the specimen. Sixty-three foetuses were examined for presence of cerebellar fissures only after filling their vascular system with ink-gelatin and cutting serial sagittal frozen sections, 100 micron thick. A morphological comparison of the foliation in normal and malnourished foetuses suggested a slight delay in the malnourished ones, albeit the earliest fissures were visible on the same day as in normal foetuses. The existence of a developmental alteration due to malnutrition was demonstrated by a decrease in the length of the pial surface and a surface folding index day on E 22. The alteration is discussed in relation to previously reported changes in cerebellar development during malnutrition, such as delayed Purkinje cell formation and alterations in proliferation/differentiation in the EGL.

Microscopic effects of predator digestion on the surfaces of bones and teeth.

PubMed

Rensberger, J M; Krentz, H B

1988-09-01

Concentrations of small fossil mammals are frequently encountered in Cenozoic deposits, but the causes for such accumulations have seldom been determined. In many cases the tooth, jaw, and limb fragments appear to be well-preserved under light microscopy, and it is difficult to differentiate damage due to predator digestion from breakage and abrasion due to physical agents. In order to find more specific evidence of predator digestion, we used a scanning electron microscope (SEM) to examine the surface microstructure of bones and teeth consumed by Bubo virginianus (great horned owl) and Canis latrans (coyote), which prey upon similar species. Effects of digestion were found on all the digested bones and teeth examined. The effects on bone include distinctive sets of pits and fissures, dissolution, and physical polishing. The pits and fissures are apparently caused by solution that commences in canals beneath the surface of the bone. The most conspicuous effects on teeth are island-like pillars of dentin surrounded by deep solution fissures. The effects of digestion by coyote and owl are fundamentally the same but differ in degree of development. Bone digested by the owl shows a greater degree of polishing and rounding of edges but has less extensive fissuring. Wide variation in the degree of surface damage occurs in bones digested by the coyote, even within a single fecal pellet.

In vitro fragmentation efficiency of holmium: yttrium-aluminum-garnet (YAG) laser lithotripsy--a comprehensive study encompassing different frequencies, pulse energies, total power levels and laser fibre diameters.

PubMed

Kronenberg, Peter; Traxer, Olivier

2014-08-01

To assess the fragmentation (ablation) efficiency of laser lithotripsy along a wide range of pulse energies, frequencies, power settings and different laser fibres, in particular to compare high- with low-frequency lithotripsy using a dynamic and innovative testing procedure free from any human interaction bias. An automated laser fragmentation testing system was developed. The unmoving laser fibres fired at the surface of an artificial stone while the stone was moved past at a constant velocity, thus creating a fissure. The lithotripter settings were 0.2-1.2 J pulse energies, 5-40 Hz frequencies, 4-20 W power levels, and 200 and 550 μm core laser fibres. Fissure width, depth, and volume were analysed and comparisons between laser settings, fibres and ablation rates were made. Low frequency-high pulse energy (LoFr-HiPE) settings were (up to six times) more ablative than high frequency-low pulse energy (HiFr-LoPE) at the same power levels (P < 0.001), as they produced deeper (P < 0.01) and wider (P < 0.001) fissures. There were linear correlations between pulse energy and fragmentation volume, fissure width, and fissure depth (all P < 0.001). Total power did not correlate with fragmentation measurements. Laser fibre diameter did not affect fragmentation volume (P = 0.81), except at very low pulse energies (0.2 J), where the large fibre was less efficient (P = 0.015). At the same total power level, LoFr-HiPE lithotripsy was most efficient. Pulse energy was the key variable that drove fragmentation efficiency. Attention must be paid to prevent the formation of time-consuming bulky debris and adapt the lithotripter settings to one's needs. As fibre diameter did not affect fragmentation efficiency, small fibres are preferable due to better scope irrigation and manoeuvrability. © 2013 The Authors. BJU International © 2013 BJU International.

FREQUENCY OF POST-OPERATIVE FAECAL INCONTINENCE IN PATIENTS WITH CLOSED AND OPEN INTERNAL ANAL SPHINCTEROTOMY.

PubMed

Ghayas, Nighat; Younus, Syed Muneeb; Mirani, Abdul Jabbar; Ghayasuddin, Mohammed; Qazi, Aamna; Suchdev, Sunil Dutt; Bakshi, Saqib Kamran

2015-01-01

Fissure in ano is one of the commonest benign and painful proctologic diseases causing considerable morbidity and reduction in quality of life. There are medical as well as surgical treatment options for anal fissure. The study was conducted to compare the frequency of postoperative faecal incontinence in patients with closed lateral internal anal sphincterotomy with von-greaves knife versus standard Park's operation (open method) for chronic anal fissure. This was a randomized controlled trial (RCT) was conducted at the Department of Surgery, KVSS, S.I.T.E. Hospital, Karachi, for a period of six months from 13th February to 12th August 2011. Ninety four consecutive patients having chronic anal fissure were assigned through blocked randomization to groups A & B, with 47 patients in each group. Closed lateral internal anal sphincterotomy (CLIAS) via von-greaves knife was carried out in patients of group-A whereas patients of group-B were subjected to open internal anal sphincterotomy (OIAS) also known as Parks' procedure. Faecal incontinence was noted on the 5th post-operative day. Data was analysed using SPSS 16. There were 81 (86.2%) males and 13 (13.8%) females with male to female ratio being 6:1. Mean age was 38.38 mp ± 14.56 years. Post-operative faecal incontinence in patients undergoing CLIAS was 4.3% while it was 21.3% in those undergoing OIAS with a p-value of 0.027. CLIAS with von-greaves knife is effective in reducing faecal incontinence on 5th postoperative day as compared to standard OIAS. CLIAS with von-greaves knife is effective in reducing faecal incontinence on 5th postoperative day as compared to OIAS (Park's procedure). Therefore, this technique may be used in future regularly to treat chronic anal fissure for prevention of this morbidity.

A conceptual hydrodynamic model of a geological discontinuity in hard rock aquifers: Example of a quartz reef in granitic terrain in South India

NASA Astrophysics Data System (ADS)

Dewandel, Benoît; Lachassagne, Patrick; Zaidi, Faisal K.; Chandra, Subash

2011-08-01

SummaryThe structure and hydrodynamic properties of geological discontinuities and of a deeply weathered granite aquifer near these structures are described on the basis of geological, geophysical and hydrodynamic investigations in two sites of South India located along a 20-40-m-wide quartz reef intruding a weathered Archean biotite granite. One of the two sites also comprises a metre-wide dolerite dyke. Weathering processes appear to be at the origin of fissures development and of a related enhanced local hydraulic conductivity, both in the quartz reef and in the surrounding granite. The weathering profile in the granite (saprolite and fissured layer) is characterized by an abrupt deepening of the weathered layers in the granite near the contact and in the quartz reef itself. Therefore, the weathering profile shows a 'U'-shape geometry with, among others, the verticalization of the granite's fissured layer. The hydraulic conductivity of this verticalized layer is on average 5 × 10 -6 m/s and storativity about 10 -3 (-). The hydraulic conductivity of the fissured quartz is 4-6 × 10 -6 m/s and its storativity about 3-5 × 10 -4 (-). Both media are also characterized by a matrix hydraulic conductivity (10 -7-10 -9 m/s) and by a significant heterogeneity in hydrodynamic properties that generates preferential flow paths along the sub-vertical fissures parallel to the reef axis. A special attention has been paid for characterizing this heterogeneity. The weathering of the dolerite dyke, however, results in a local low hydraulic conductivity, which consequently does not enhance either the thickness of weathered granite layers or its hydraulic conductivity. The obtained results complete the conceptual hydrogeological model developed for weathered granite aquifers in characterizing the relationships between weathering processes and hydrodynamic properties near geological discontinuities.

Optimal Dosing of Botulinum Toxin for Treatment of Chronic Anal Fissure: A Systematic Review and Meta-Analysis.

PubMed

Lin, Jin Xin; Krishna, Sanjeev; Su'a, Bruce; Hill, Andrew G

2016-09-01

Chronic anal fissures are associated with significant morbidity and reduced quality of life. Studies have investigated the efficacy of botulinum toxin with variable results; thus, there is currently no consensus on botulinum toxin dose or injection sites. This study aimed to systematically analyze trials studying the efficacy of botulinum toxin for treatment of chronic anal fissure to identify an optimum dosage and injection regimen. A comprehensive review of the literature was conducted according to PRISMA guidelines. PubMed/Medline, Embase, Scopus, and the Cochrane Library were searched from inception to June 2015. All clinical trials that investigated the efficacy of botulinum toxin for chronic anal fissure were selected according to specific criteria. The interventions used were various doses of botulinum toxin. Clinical outcomes, dosage, and injection site data were evaluated with weighted pooled results for each dosage and 95% confidence intervals. There were 1158 patients, with 661 in botulinum toxin treatment arms, from 18 clinical trials included in this review. The outcomes of interest were 3-month healing, incontinence, and recurrence rates. Meta-regression analysis demonstrated a small decrease in healing rate (0.34%; 95% CI, 0-0.68; p = 0.048) with each increase in dosage, a small increase in incontinence rate (1.02 times; 95% CI, 1.0002-1.049; p = 0.048) with each increase in dosage and a small increase in recurrence rate (1.037 times; 95% CI, 1.018-1.057; p = 0.0002) with each increase in dosage. The optimum injection site could not be determined. This study was limited by weaknesses in the underlying evidence, such as variable quality, short follow-up, and a limited range of doses represented. Fissure healing with lower doses of botulinum toxin is as effective as with high doses. Lower doses also reduce the risk of incontinence and recurrence in the long term.

Modelling the migration of contaminants through variably saturated dual-porosity, dual-permeability chalk.

PubMed

Brouyère, Serge

2006-01-10

In the Hesbaye region in Belgium, tracer tests performed in variably saturated fissured chalk rocks presented very contrasting results in terms of transit times, according to artificially controlled water recharge conditions prevailing during the experiments. Under intense recharge conditions, tracers migrated across the partially or fully saturated fissure network, at high velocity in accordance with the high hydraulic conductivity and low effective porosity (fracture porosity). At the same time, a portion of the tracer was temporarily retarded in the almost immobile water located in the matrix. Under natural infiltration conditions, the fissure network remained inactive. Tracers migrated downward through the matrix, at low velocity in relation with the low hydraulic conductivity and the large porosity of the matrix. Based on these observations, Brouyère et al. (2004a) [Brouyère, S., Dassargues, A., Hallet, V., 2004a. Migration of contaminants through the unsaturated zone overlying the Hesbaye chalky aquifer in Belgium: a field investigation, J. Contam. Hydrol., 72 (1-4), 135-164, doi: 10.1016/j.conhyd.2003.10.009] proposed a conceptual model in order to explain the migration of solutes in variably saturated, dual-porosity, dual-permeability chalk. Here, mathematical and numerical modelling of tracer and contaminant migration in variably saturated fissured chalk is presented, considering the aforementioned conceptual model. A new mathematical formulation is proposed to represent the unsaturated properties of the fissured chalk in a more dynamic and appropriate way. At the same time, the rock water content is partitioned between mobile and immobile water phases, as a function of the water saturation of the chalk rock. The groundwater flow and contaminant transport in the variably saturated chalk is solved using the control volume finite element method. Modelling the field tracer experiments performed in the variably saturated chalk shows the adequacy and usefulness of the new conceptual, mathematical and numerical model.

Cracks in a Debris Apron

NASA Image and Video Library

2015-03-11

This observation from NASA Mars Reconnaissance Orbiter shows the nature of large fissures in a smooth apron around a mound in the Phlegra region. The apron could be (or could have been) ice-rich, so one possibility is that the fissures are related to ice loss. Based on radar data from MRO combined with studies of the region's geology from other orbiters, scientists think that extensive glaciers covered this region several hundred million years ago. http://photojournal.jpl.nasa.gov/catalog/PIA19307

Impact of adhesive and photoactivation method on sealant integrity and polymer network formation.

PubMed

Borges, Boniek Castillo Dutra; Pereira, Fabrício Lopes da Rocha; Alonso, Roberta Caroline Bruschi; Braz, Rodivan; Montes, Marcos Antônio Japiassú Resende; Pinheiro, Isauremi Vieira de Assunção; Santos, Alex José Souza dos

2012-01-01

We evaluated the influence of photoactivation method and hydrophobic resin (HR) application on the marginal and internal adaptation, hardness (KHN), and crosslink density (CLD) of a resin-based fissure sealant. Model fissures were created in bovine enamel fragments (n = 10) and sealed using one of the following protocols: no adhesive system + photoactivation of the sealant using continuous light (CL), no adhesive system + photoactivation of the sealant using the soft-start method (SS), HR + CL, or HR + SS. Marginal and internal gaps and KHN were assessed after storage in water for 24 h. The CLD was indirectly assessed by repeating the KHN measurement after 24 h of immersion in 100% ethanol. There was no difference among the samples with regard to marginal or internal adaptation. The KHN and CLD were similar for samples cured using either photoactivation method. Use of a hydrophobic resin prior to placement of fissure sealants and curing the sealant using the soft-start method may not provide any positive influence on integrity or crosslink density.

Choroidal fissure acts as an overflow device in cerebrospinal fluid drainage: morphological comparison between idiopathic and secondary normal-pressure hydrocephalus

PubMed Central

Yamada, Shigeki; Ishikawa, Masatsune; Iwamuro, Yasushi; Yamamoto, Kazuo

2016-01-01

To clarify the pathogenesis of two different types of adult-onset normal-pressure hydrocephalus (NPH), we investigated cerebrospinal fluid distribution on the high-field three-dimensional MRI. The subarachnoid spaces in secondary NPH were smaller than those in the controls, whereas those in idiopathic NPH were of similar size to the controls. In idiopathic NPH, however, the basal cistern and Sylvian fissure were enlarged in concurrence with ventricular enlargement towards the z-direction, but the convexity subarachnoid space was severely diminished. In this article, we provide evidence that the key cause of the disproportionate cerebrospinal fluid distribution in idiopathic NPH is the compensatory direct CSF communication between the inferior horn of the lateral ventricles and the ambient cistern at the choroidal fissure. In contrast, all parts of the subarachnoid spaces were equally and severely decreased in secondary NPH. Blockage of CSF drainage from the subarachnoid spaces could cause the omnidirectional ventricular enlargement in secondary NPH. PMID:27941913

[Banana peel: a possible source of infection in the treatment of nipple fissures].

PubMed

Novak, Franz Reis; de Almeida, João Aprígio Guerra; de Souza e Silva, Rosana

2003-01-01

To study the microbiology of banana peel being sold in the city of Rio de Janeiro, in an attempt to determine the possibility that the peel may represent a source of infection for women who use it to treat nipple fissures. The following microorganisms were studied in 20 banana peel samples: mesophiles, total coliforms, fecal coliforms, Pseudomonas aeruginosa, lipolytic and proteolytic microorganisms, molds and yeasts, lactic bacteria, and coagulase-positive staphylococcus. The microbiological analyses revealed the occurrence of several typical groups of microorganisms, with the following distribution of positive results being detected in banana peel samples: mesophiles, 100%; total coliforms, 20%; coagulase-positive staphylococcus, 25%; molds and yeasts, 30%; proteolytic microorganisms, 70%; lipolytic microorganisms, 30%, and lactic bacteria, 95%. Fecal coliforms and Pseudomonas aeruginosa were not isolated. The results show the presence of potentially pathogenic microorganisms in levels which could compromise the microbiological quality of the banana peel. Its use for the treatment of nipple fissures can initiate an infectious process.

Can prevention eliminate caries?

PubMed

O'Mullane, D

1995-07-01

There are four main factors involved in the carious process: at-risk tooth structure, plaque flora, fermentable carbohydrates, and time. Based on our knowledge of the carious process, four main preventive strategies have been developed over the years, namely, fluorides, fissure sealing, dietary choice, and plaque control. Fluorides are having a major impact on smooth-surface caries; hence, strategies combining fluorides and fissure sealing are very effective. However, use of fissure sealing is still problematic. Changing dietary practices with a view to reducing dental caries seems to be having little impact on a global scale. Plaque control, as practiced routinely by the majority of people, is not sufficient to result in caries reductions. Deprivation and poverty are strongly associated with high caries levels. Although the preventive strategies currently available are likely to result in lower caries levels for many, for logistical reasons and because of factors associated with deprivation and poverty, caries is likely to remain a major public health problem in most communities for the foreseeable future.

Double-porosity models for a fissured groundwater reservoir with fracture skin

USGS Publications Warehouse

Moench, Allen F.

1984-01-01

Theories of flow to a well in a double-porosity groundwater reservoir are modified to incorporate effects of a thin layer of low-permeability material or fracture skin that may be present at fracture-block interfaces as a result of mineral deposition or alteration. The commonly used theory for flow in double- porosity formations that is based upon the assumption of pseudo–steady state block-to-fissure flow is shown to be a special case of the theory presented in this paper. The latter is based on the assumption of transient block-to-fissure flow with fracture skin. Under conditions where fracture skin has a hydraulic conductivity that is less than that of the matrix rock, it may be assumed to impede the interchange of fluid between the fissures and blocks. Resistance to flow at fracture-block interfaces tends to reduce spatial variation of hydraulic head gradients within the blocks. This provides theoretical justification for neglecting the divergence of flow in the blocks as required by the pseudo–steady state flow model. Coupled boundary value problems for flow to a well discharging at a constant rate were solved in the Laplace domain. Both slab-shaped and sphere-shaped blocks were considered, as were effects of well bore storage and well bore skin. Results obtained by numerical inversion were used to construct dimensionless-type curves that were applied to well test data, for a pumped well and for an observation well, from the fractured volcanic rock terrane of the Nevada Test Site.

Thermomechanical behavior of mica layers with lenticular fissures

NASA Astrophysics Data System (ADS)

Yang, Michael Xinyi

The thermomechanical behavior of natural phlogopite mica specimens from seven different origins is characterized. An initial heat treatment, to a temperature between 300°C and 400°C, is found to form fissures that stabilize in the material. Following the initial heat treatment, all the phlogopite specimens, regardless of their origin and polytype, exhibit the extraordinarily large thermal expansion (intumescence), more than 200% at 600°C, in the direction perpendicular to the basal planes. This phenomenon is strictly reproducible when tested under a range of thermal conditions including thermal shock, multiple thermal fatigue cycles, varying heating or cooling rates and isothermal heating over an extensive period of time at different temperatures up to 585°C. The hysteresis, associated with the thermal cycle, is increased when the specimen is heated or cooled at a faster rate. The maximum coefficient of linear thermal expansion, approximately 10 -2°C-1, is observed over the temperature range 100--120°C. This is due to the non-structural water, entrapped within the layer structure, which undergoes a phase transition and causes the mica layers to expand abruptly. A model of lenticular fissures is developed based on thin-plate mechanics and thermodynamics assumptions. The state of a lenticular fissure with water vapor molecules is determined to correlate the experimental parameters with the material properties. The average density of water vapor molecules within a lenticular fissure is calculated to be ˜1025 m 3 for the temperature interval between 100°C and 275°C. The concentration of non-structure water, based on the model calculation, is less than 0.1% by weight. Acoustic emission (AE) signals have been reported by Pranevicius et al. (1995) to correspond to the microstructure changes as the internal lenticular fissures develop in phlogopite. This technique has also been proven feasible to characterize the thermomechanical behavior of other layer structures (Pranevicius 1995). Other layer structures are reviewed to determine their potential reversible thermomechanical properties. When phlogopite is used as a model specimen to relate microstructure to intumescence, two criteria are established for selection of the layer structures of potential intumescence. The first is the need for flexible and elastic layers to withstand the strain imposed by large lateral expansion. The second is the requirement of a high degree for intercalation. Possible candidates that fit these two criteria are identified. Finally, a few potential applications of layer structures of intumescence are discussed, and future research in this area is proposed. (Abstract shortened by UMI.)

Enceladus: Starting Hydrothermal Activity

NASA Technical Reports Server (NTRS)

Matson, D. L.; Castillo-Rogez, J. C.; Johnson, T. V.; Lunine, J. I.; Davies, A. G.

2011-01-01

We describe a process for starting the hydrothermal activity in Enceladus' South Polar Region. The process takes advantage of fissures that reach the water table, about 1 kilometer below the surface. Filling these fissures with fresh ocean water initiates a flow of water up from an ocean that can be self-sustaining. In this hypothesis the heat to sustain the thermal anomalies and the plumes comes from a slightly warm ocean at depth. The heat is brought to the surface by water that circulates up, through the crust and then returns to the ocean.

Painful ophthalmoplegia secondary to a mucocele involving the sella turcica, superior orbital fissure, and sphenoid sinus.

PubMed

Clarke, H; Clarke, V; Gill, J; St John, A; Lashley, M

1992-03-01

A case of painful ophthalmoplegia associated with an extensive lesion involving the sella turcica, superior orbital fissure, and sphenoid sinus in a 57-year-old man is reported. Even though nasal and ocular symptoms and signs represent the usual features of sphenoidal mucoceles, extension to the intracranial cavity as seen in this lesion is rare. Surgical exploration via a sublabial, transseptal approach revealed a mucocele of the sphenoid sinus. This case exhibited extensive and aggressive behavior simulating a malignant neoplasm.

Surface fracturing and graben subsidence during the 2014 Bárdarbunga dike intrusion in Iceland

NASA Astrophysics Data System (ADS)

Rut Hjartardóttir, Ásta; Einarsson, Páll; Tumi Gudmundsson, Magnús; Högnadóttir, Thordís

2015-04-01

A dike propagated laterally away from the Bárdarbunga central volcano in August 2014. The dike propagated about 48 km towards the northeast and north-northeast, mostly beneath the Vatnajökull glacier. However, the farthest 8 km of the dike were located north of the glacier, where the ice-free area allowed surface fractures and graben subsidence to be observed. This dike intrusion was accompanied by eruptions, the most prominent ones occurring within the graben at the distal end of the dike. In this study, photographs taken from airplanes were rectified by using the ArcGIS software. This was done in order to map the fractures and eruptive fissures which were formed or reactivated during this dike intrusion, and to show the temporal evolution of the fracture pattern. Ground deformation across the graben was measured from an airplane with a radar altimeter and kinematic GPS. The propagation of the dike was shown by laterally propagating earthquakes and by ground deformation recorded by GPS geodetic network. Three days after the dike had propagated north of the Vatnajökull glacier, new and reactivated fractures were detected in this area, above the dike. The fractures delineated two grabens in direct continuation of each other. The southern graben extended 5 km northwards from the glacier boundary, and was 700-1000 m wide. Before the eruptions, the northern graben was seen ~6.6-7.5 km north of the glacier, and was only 250-450 m wide. Two days later, on the 29th of August, a four-hour long eruption took place on a 600 m long eruptive fissure 6 km north of the glacier. Then, the narrow northern graben was seen extending about 1-1.6 km farther to the south than before the eruption, with the new eruptive fissure in the middle of it. The eruption resumed again two days later, extending the same eruptive fissure towards the south and north, to a total of ~1900 m length. This eruption is still ongoing (in January 2014). On the 5th of September, three short (~100 to 250 m) eruptive fissures also opened up ~3 km north of the glacier, although these eruptions only lasted two days. Notably, the eruptive fissures activated on 29th and 31st August were located within the eruptive fissures of the older Holuhraun lava, which erupted in the 17th and/or 18th century. A profile taken on the 30th December 2014 by radar measurements across the southern graben, 4 km north of the glacier, showed that the graben had then subsided ~4-5 m, compared with a TanDEM-X Digital Elevation Model acquired before the dike intrusion. The width of a graben implies the depth to the top of the dike. The narrow grabens observed before the eruptions thus indicated that the dike was shallow, and that an eruption was likely to occur. The width of active grabens therefore is an important observable in hazard assessment during dike intrusions.

Chronic anal fissure: morphometric analysis of the anal canal at 3.0 Tesla MR imaging.

PubMed

Erden, Ayşe; Peker, Elif; Gençtürk, Zeynep Bıyıklı

2017-02-01

OBJECTıVE: To compare the morphometric data relating to the muscular structures of the anal canal, in patients with chronic anal fissure and in control group, examined at a 3.0 Tesla MR system. Forty-seven consecutive patients with chronic anal fissure and randomly selected 40 patients who had no claims for perianal disease during their life time were included in the study. T2-weighted sagittal, high-resolution (HR) T2-weighted, and contrast-enhanced fat-suppressed T1-weighted oblique axial and oblique coronal images were retrospectively analyzed by two observers in consensus. Thickness of sphincteric muscles, anal canal length, anorectal angle, thickness of anococcygeal ligament, depth of Minor triangle, width between subcutaneous sphincters, vascularity of posterior commissure, visibility of posterosuperior projection of external sphincter, and angle between the distal anal canal and posterosuperior projection of external sphincter (H angle) in patients and in controls were compared and analyzed using t test, Mann-Whitney U test, and Spearman correlation. The patients with chronic anal fissure had longer anal canal (51.50 mm ± 0.91 vs. 44.11 mm ± 0.71; p = 0.000), thicker internal anal sphincter muscle at mid-anal level (4.18 ± 0.15 vs. 3.39 ± 0.07; p = 0.007), and wider space between subcutaneous external sphincters (11.39 ± 0.50 vs. 6.89 ± 0.22; p = 0.000). In patients, there was a positive correlation between H angle and external sphincter thickness at proximal (r = 0.347; p = 0.021), middle (r = 0427; p = 0.000), and distal (r = 0.518; p = 0.000)) levels of the anal canal. CONCLUSıON: 3.0 Tesla MR imaging provides detailed information about the morphometric changes in the anal sphincter muscles in patients with chronic anal fissure.

Assessing eruption column height in ancient flood basalt eruptions

NASA Astrophysics Data System (ADS)

Glaze, Lori S.; Self, Stephen; Schmidt, Anja; Hunter, Stephen J.

2017-01-01

A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12-16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13-17 km for source widths of between 4-16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at ∼ 45 ° N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the ∼ 180km of known Roza fissure length could have supported ∼36 explosive events/phases, each with a duration of 3-4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (∼ 66Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained flood basalt eruptions could have influenced climate on time scales of decades to centuries but the location (i.e., latitude) of the province and relevant paleoclimate is important and must be considered.

Assessing Eruption Column Height in Ancient Flood Basalt Eruptions

NASA Technical Reports Server (NTRS)

Glaze, Lori S.; Self, Stephen; Schmidt, Anja; Hunter, Stephen J.

2015-01-01

A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12-16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13-17 km for source widths of between 4-16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at approximately 45 deg N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the approximately 180 km of known Roza fissure length could have supported approximately 36 explosive events/phases, each with a duration of 3-4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (approximately 66 Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained flood basalt eruptions could have influenced climate on time scales of decades to centuries but the location (i.e., latitude) of the province and relevant paleoclimate is important and must be considered.

An emerging, recognizable facial phenotype in association with mutations in GLI-similar 3 (GLIS3).

PubMed

Dimitri, Paul; De Franco, Elisa; Habeb, Abdelhadi M; Gurbuz, Fatih; Moussa, Khairya; Taha, Doris; Wales, Jerry K H; Hogue, Jacob; Slavotinek, Anne; Shetty, Ambika; Balasubramanian, Meena

2016-07-01

Neonatal diabetes and hypothyroidism (NDH) syndrome was first described in 2003 in a consanguineous Saudi Arabian family where two out of four siblings were reported to have presented with proportionate IUGR, neonatal non-autoimmune diabetes mellitus, severe congenital hypothyroidism, cholestasis, congenital glaucoma, and polycystic kidneys. Liver disease progressed to hepatic fibrosis. The renal disease was characterized by enlarged kidneys and multiple small cysts with deficient cortico-medullary junction differentiation and normal kidney function. There was minor facial dysmorphism (depressed nasal bridge, large anterior fontanelle, long philtrum) reported but no facial photographs were published. Mutations in the transcription factor GLI-similar 3 (GLIS3) gene in the original family and two other families were subsequently reported in 2006. All affected individuals had neonatal diabetes, congenital hypothyroidism but glaucoma and liver and kidney involvement were less consistent features. Detailed descriptions of the facial dysmorphism have not been reported previously. In this report, we describe the common facial dysmorphism consisting of bilateral low-set ears, depressed nasal bridge with overhanging columella, elongated, upslanted palpebral fissures, persistent long philtrum with a thin vermilion border of the upper lip in a cohort of seven patients with GLIS3 mutations and report the emergence of a distinct, probably recognizable facial gestalt in this group which evolves with age. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Long term radiological features of radiation-induced lung damage.

PubMed

Veiga, Catarina; Landau, David; McClelland, Jamie R; Ledermann, Jonathan A; Hawkes, David; Janes, Sam M; Devaraj, Anand

2018-02-01

To describe the radiological findings of radiation-induced lung damage (RILD) present on CT imaging of lung cancer patients 12 months after radical chemoradiation. Baseline and 12-month CT scans of 33 patients were reviewed from a phase I/II clinical trial of isotoxic chemoradiation (IDEAL CRT). CT findings were scored in three categories derived from eleven sub-categories: (1) parenchymal change, defined as the presence of consolidation, ground-glass opacities (GGOs), traction bronchiectasis and/or reticulation; (2) lung volume reduction, identified through reduction in lung height and/or distortions in fissures, diaphragm, anterior junction line and major airways anatomy, and (3) pleural changes, either thickening and/or effusion. Six patients were excluded from the analysis due to anatomical changes caused by partial lung collapse and abscess. All remaining 27 patients had radiological evidence of lung damage. The three categories, parenchymal change, shrinkage and pleural change were present in 100%, 96% and 82% respectively. All patients had at least two categories of change present and 72% all three. GGOs, reticulation and traction bronchiectasis were present in 44%, 52% and 37% of patients. Parenchymal change, lung shrinkage and pleural change are present in a high proportion of patients and are frequently identified in RILD. GGOs, reticulation and traction bronchiectasis are common at 12 months but not diagnostic. Copyright © 2017 Elsevier B.V. All rights reserved.

Pax2 regulates a fadd-dependent molecular switch that drives tissue fusion during eye development.

PubMed

Viringipurampeer, Ishaq A; Ferreira, Todd; DeMaria, Shannon; Yoon, Jookyung J; Shan, Xianghong; Moosajee, Mariya; Gregory-Evans, Kevin; Ngai, John; Gregory-Evans, Cheryl Y

2012-05-15

Tissue fusion is an essential morphogenetic mechanism in development, playing a fundamental role in developing neural tube, palate and the optic fissure. Disruption of genes associated with the tissue fusion can lead to congenital malformations, such as spina bifida, cleft lip/palate and ocular coloboma. For instance, the Pax2 transcription factor is required for optic fissure closure, although the mechanism of Pax2 action leading to tissue fusion remains elusive. This lack of information defining how transcription factors drive tissue morphogenesis at the cellular level is hampering new treatments options. Through loss- and gain-of-function analysis, we now establish that pax2 in combination with vax2 directly regulate the fas-associated death domain (fadd) gene. In the presence of fadd, cell proliferation is restricted in the developing eye through a caspase-dependent pathway. However, the loss of fadd results in a proliferation defect and concomitant activation of the necroptosis pathway through RIP1/RIP3 activity, leading to an abnormal open fissure. Inhibition of RIP1 with the small molecule drug necrostatin-1 rescues the pax2 eye fusion defect, thereby overcoming the underlying genetic defect. Thus, fadd has an essential physiological function in protecting the developing optic fissure neuroepithelium from RIP3-dependent necroptosis. This study demonstrates the molecular hierarchies that regulate a cellular switch between proliferation and the apoptotic and necroptotic cell death pathways, which in combination drive tissue morphogenesis. Furthermore, our data suggest that future therapeutic strategies may be based on small molecule drugs that can bypass the gene defects causing common congenital tissue fusion defects.

Land subsidence and earth fissures in south-central and southern Arizona, USA

NASA Astrophysics Data System (ADS)

Conway, Brian D.

2016-05-01

Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth fissure attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth fissuring. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005-2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth fissures. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR's InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal.

European Fissure Sealant Guidelines: assessment using AGREE II.

PubMed

San Martin-Galindo, L; Rodríguez-Lozano, F J; Abalos-Labruzzi, C; Niederman, R

2017-02-01

Pit and fissure sealants are effective in reducing the incidence of occlusal caries, and multiple clinical practice guidelines (CPGs) have been developed for recommending their proper use. The usefulness of CPGs depends on their quality and on the rigour of the guideline development process. A study was made to assess the quality of current European CPGs based on the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument, which uses 23 key items rated on a 7-point scale to assess practice guideline development and the quality of reporting. A search was conducted for fissure sealant guidelines for preventing caries in children and adults at high and low risk published in the last 10 years. Calibration was carried out before scoring to assess agreement between the appraisers using the AGREE II instrument. The searches identified 19 relevant guidelines, and following application of the inclusion/exclusion criteria, three guidelines were retained for evaluation. The proportion of observed agreement was calculated, expressed by the agreement separately for positive and negative ratings (PA = 0.89, NA = 0-91). The results of the guideline assessments revealed the highest score for the Irish guideline, a moderate score for the French guideline and the lowest score for the European guideline. Based on the AGREE II instrument, the results obtained show significant variation in the quality assessment of the three European Fissure Sealant Guidelines. Future studies should be carried out both to develop quality dental CPGs and to investigate effective ways of adopting them. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fractography of the high temperature hydrogen attack of a medium carbon steel

NASA Technical Reports Server (NTRS)

Melson, H. G.; Moorhead, R. D.

1975-01-01

Microscopic fracture processes were studied which are associated with hydrogen attack of a medium carbon steel in a well-controlled, high-temperature, high-purity hydrogen environment. Exposure to a hydrogen pressure and temperature of 3.5 MN/m2 and 575 C was found to degrade room temperature tensile properties with increasing exposure time. After 408 hr, yield and ultimate strengths were reduced by more than 40 percent and elongation was reduced to less than 2 percent. Initial fissure formation was found to be associated with manganese rich particles, most probably manganese oxide, aligned in the microstructure during the rolling operation. Fissure growth was found to be associated with a reduction in carbide content of the microstructure and was inhibited by the depletion of carbon. The interior surfaces of sectioned fissures or bubbles exhibit both primary and secondary cracking by intergranular separation. The grain surfaces were rough and rounded, suggesting a diffusion-associated separation process. Specimens that failed at room temperature after exposure to hydrogen were found to exhibit mixed mode fracture having varying amounts of intergranular separation, dimple formation, and cleavage, depending on exposure time.

Hydrogen attack - Influence of hydrogen sulfide. [on carbon steel

NASA Technical Reports Server (NTRS)

Eliezer, D.; Nelson, H. G.

1978-01-01

An experimental study is conducted on 12.5-mm-thick SAE 1020 steel (plain carbon steel) plate to assess hydrogen attack at room temperature after specimen exposure at 525 C to hydrogen and a blend of hydrogen sulfide and hydrogen at a pressure of 3.5 MN/sq m for exposure times up to 240 hr. The results are discussed in terms of tensile properties, fissure formation, and surface scales. It is shown that hydrogen attack from a high-purity hydrogen environment is severe, with the formation of numerous methane fissures and bubbles along with a significant reduction in the room-temperature tensile yield and ultimate strengths. However, no hydrogen attack is observed in the hydrogen/hydrogen sulfide blend environment, i.e. no fissure or bubble formation occurred and the room-temperature tensile properties remained unchanged. It is suggested that the observed porous discontinuous scale of FeS acts as a barrier to hydrogen entry, thus reducing its effective equilibrium solubility in the iron lattice. Therefore, hydrogen attack should not occur in pressure-vessel steels used in many coal gasification processes.

Fractography of the high temperature hydrogen attack of a medium carbon steel

NASA Technical Reports Server (NTRS)

Nelson, H. G.; Moorhead, R. D.

1976-01-01

Results are reported for an experimental study of the microscopic fracture processes associated with hydrogen attack of a commercially produced plain carbon steel in a well-controlled high-temperature hydrogen environment of high purity. In the experiments, sheet samples were exposed to laboratory-grade hydrogen at a pressure of 3.5 MN/sq m and a temperature of 575 C. The fractography of gas-filled fissures and failed tension specimens is analyzed in an effort to identify any predominant microstructural defect associated with fissure formation, the prevalent modes of fracture, and the contribution of gas-filled fissures to the overall failure process. It is found that the tensile properties of the examined steel were significantly degraded after as few as 136 hr of exposure to a high-purity hydrogen atmosphere at 575 C; that the yield strength, ultimate strength, and elongation at fracture were all reduced progressively with increasing exposure time; and that the yield and ultimate strengths were reduced more than 40% after 408 hr while elongation was reduced to less than 2%.

Systematic review of noninvasive treatments to arrest dentin non-cavitated caries lesions

PubMed Central

de Assunção, Isauremi Vieira; da Costa, Giovanna de Fátima Alves; Borges, Boniek Castillo Dutra

2014-01-01

AIM: To systematically review the literature on the efficacy of noninvasive methods of arresting the progression of non-cavitated occlusal carious lesions in dentin. METHODS: The Medline/PubMed, LILACS, SciELO and Scopus databases were searched to identify relevant publications through to November 2013. Only clinical trials evaluating the ability of noninvasive methods to arrest the progression of occlusal non-cavitated carious lesions in dentin were included. Screening, data extraction and quality assessment were conducted independently and in duplicate. RESULTS: Of 167 citations identified, nine full text articles were screened and five were included in the analysis. All papers reported on occlusal fissure sealing using a self-curing glass ionomer (n = 1) or resin-based (n = 4) sealant. Only the use of resin-based sealant to obliterate occlusal fissures arrested the progression of non-cavitated occlusal carious lesions in dentin. CONCLUSION: Occlusal fissure sealing with a resin-based sealant may arrest the progression of non-cavitated occlusal dentinal caries. Further clinical trials with longer follow-up times should be performed to increase scientific evidence. PMID:24868513

The relationship between the nitrate concentration and hydrology of a small chalk spring; Israel

NASA Astrophysics Data System (ADS)

Burg, Avi; Heaton, Tim H. E.

1998-01-01

Discharge from a spring draining a small, perched, Cretaceous chalk aquifer in the Upper Galilee, Israel, was monitored over a period of two years. The water has elevated nitrate concentrations, with 15N/ 14N and chemical data suggesting that it is a mixture of low-nitrate and high-nitrate end-members; the latter derived from the sewage of a centuries-old village served by septic tanks. Hydrograph data allowed distinction between fissure flow during the period of winter rainfall, and matrix drainage during the dry summer months. These different flow types, however, did not have markedly different nitrate concentrations: a 50-fold increase in spring discharge due to fissure flow, compared with matrix drainage, was reflected in only a 35% decrease in nitrate concentrations. The relatively high nitrate concentrations in the fissure waters suggests that they have had close contact with, and are possibly displaced from the matrix. This should help to accelerate the decline in the spring's nitrate concentrations following the recent completion of the village's central sewage drainage system.

Granicus Valles

NASA Image and Video Library

2002-12-16

The force of moving water from a flood carved these teardrop-shaped islands within Granicus Valles. The orientation of the islands can be used as an indicator of the direction the water flowed. In this case, the water flowed primarily towards the upper left of the image. The image also contains many narrow sinuous channels. Geologists can determine that the floods occurred before a later tectonic event in the region. This event caused the crust to fracture into numerous blocks and fissures (grabens). Many fissures can be seen cutting across the former flood pathways. http://photojournal.jpl.nasa.gov/catalog/PIA04037

A systematic review and meta-analysis of the treatment of anal fissure.

PubMed

Nelson, R L; Manuel, D; Gumienny, C; Spencer, B; Patel, K; Schmitt, K; Castillo, D; Bravo, A; Yeboah-Sampong, A

2017-08-01

Anal fissure has a very large number of treatment options. The choice is difficult. In an effort to assist in that, choice presented here is a systematic review and meta-analysis of all published treatments for anal fissure that have been studied in randomized controlled trials. Randomized trials were sought in the Cochrane Controlled Trials Register, Medline, EMBASE and the trials registry sites clinicaltrials.gov and who/int/ictrp/search/en. Abstracts were screened, full-text studies chosen, and finally eligible studies selected and abstracted. The review was then divided into those studies that compared two or more surgical procedures and those that had at least one arm that was non-surgical. Studies were further categorized by the specific interventions and comparisons. The outcome assessed was treatment failure. Negative effects of treatment assessed were headache and anal incontinence. Risk of bias was assessed for each study, and the strength of the evidence of each comparison was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. One hundred and forty-eight eligible trials were found and assessed, 31 in the surgical group and 117 in the non-surgical group. There were 14 different operations described in the surgical group and 29 different non-surgical treatments in the non-surgical group along with partial lateral internal sphincterotomy (LIS). There were 61 different comparisons. Of these, 47 were reported in 2 or fewer studies, usually with quite small patient samples. The largest single comparison was glyceryl trinitrate (GTN) versus control with 19 studies. GTN was more effective than control in sustained cure (OR 0.68; 95% CI 0.63-0.77), but the quality of evidence was very poor because of severe heterogeneity, and risk of bias due to inadequate clinical follow-up. The only comparison to have a GRADE quality of evidence of high was a subgroup analysis of LIS versus any medical therapy (OR 0.12; CI 0.07-0.21). Most of the other studies were downgraded in GRADE due to imprecision. LIS is superior to non-surgical therapies in achieving sustained cure of fissure. Calcium channel blockers were more effective than GTN and with less risk of headache, but with only a low quality of evidence. Anal incontinence, once thought to be a frequent risk with LIS, was found in various subgroups in this review to have a risk between 3.4 and 4.4%. Among the surgical studies, manual anal stretch performed worse than LIS in the treatment of chronic anal fissure in adults. For those patients requiring surgery for anal fissure, open LIS and closed LIS appear to be equally efficacious, with a moderate GRADE quality of evidence. All other GRADE evaluations of procedures were low to very low due mostly to imprecision.

Geochemical evidence of mantle reservoir evolution during progressive rifting along the western Afar margin

NASA Astrophysics Data System (ADS)

Rooney, Tyrone O.; Mohr, Paul; Dosso, Laure; Hall, Chris

2013-02-01

The Afar triple junction, where the Red Sea, Gulf of Aden and African Rift System extension zones converge, is a pivotal domain for the study of continental-to-oceanic rift evolution. The western margin of Afar forms the southernmost sector of the western margin of the Red Sea rift where that margin enters the Ethiopian flood basalt province. Tectonism and volcanism at the triple junction had commenced by ˜31 Ma with crustal fissuring, diking and voluminous eruption of the Ethiopian-Yemen flood basalt pile. The dikes which fed the Oligocene-Quaternary lava sequence covering the western Afar rift margin provide an opportunity to probe the geochemical reservoirs associated with the evolution of a still active continental margin. 40Ar/39Ar geochronology reveals that the western Afar margin dikes span the entire history of rift evolution from the initial Oligocene flood basalt event to the development of focused zones of intrusion in rift marginal basins. Major element, trace element and isotopic (Sr-Nd-Pb-Hf) data demonstrate temporal geochemical heterogeneities resulting from variable contributions from the Afar plume, depleted asthenospheric mantle, and African lithosphere. The various dikes erupted between 31 Ma and 22 Ma all share isotopic signatures attesting to a contribution from the Afar plume, indicating this initial period in the evolution of the Afar margin was one of magma-assisted weakening of the lithosphere. From 22 Ma to 12 Ma, however, diffuse diking during continued evolution of the rift margin facilitated ascent of magmas in which depleted mantle and lithospheric sources predominated, though contributions from the Afar plume persisted. After 10 Ma, magmatic intrusion migrated eastwards towards the Afar rift floor, with an increasing fraction of the magmas derived from depleted mantle with less of a lithospheric signature. The dikes of the western Afar margin reveal that magma generation processes during the evolution of this continental rift margin are increasingly dominated by shallow decompressional melting of the ambient asthenosphere, the composition of which may in part be controlled by preferential channeling of plume material along the developing neo-oceanic axes of extension.

Complexities in Shallow Magma Transport at Kilauea (Invited)

NASA Astrophysics Data System (ADS)

Swanson, D. A.

2013-12-01

The standard model of Kilauea's shallow plumbing system includes magma storage under the caldera and conduits in the southwest rift zone (SWRZ) and the east rift zone (ERZ). As a field geologist, I find that seemingly aberrant locations and trends of some eruptive vents indicate complexities in shallow magma transport not addressed by the standard model. This model is not wrong but instead incomplete, because it does not account for the development of offshoots from the main plumbing. These offshoots supply magma to the surface at places that tell us much about the complicated stress system within the volcano. Perhaps most readily grasped are fissures peripheral to the north and south sides of the caldera. Somehow magma can apparently be injected into caldera-bounding faults from the summit reservoir complex, but the process and pathways are unclear. Of more importance is the presence of fissures with ENE trends on the east side of the caldera, including Kilauea Iki. Is this a rift zone that forms an acute angle with the ERZ? I think there is another explanation: the main part of the ERZ has migrated ~5 km SSE during the past few tens of thousands of years owing to seaward movement of the south flank, but older parts of the rift zone can be reactivated. The fissures east of the caldera have the ERZ trend and may record such reactivation; this interpretation includes the location of the largest eruption (15th century) known from Kilauea. Whether or not this interpretation has validity, the question remains: what changes in the plumbing system allow magma to erupt east of the caldera? The SWRZ can be divided into two sections, the SWRZ proper and the seismically active part (SASWRZ) southeast of the SWRZ. The total width of both sections is ~4 km. The SWRZ might be migrating SSE, as is the ERZ. Fissures in the SWRZ proper trend SW. Fissures in the SASWRZ, however, have ENE trends like that of the ERZ, although, because of en echelon offsets, the fissure zone itself trends SW. Seismicity in the SASWRZ also trends SW. This complicated area is not adequately addressed by the standard model. Possibly stresses related to seaward spreading control surface fracture patterns in the SASWRZ, but stresses related to the summit reservoir control somewhat deeper magma movement. Perhaps the hyaloclastic zone, formed as Kilauea grew above sea level, separates the two stress layers. Whatever the explanation, the observations demand attention because of the disparity between fracture trend and magma movement. In the upper ERZ, surface fractures and eruptive fissures trend ENE, but the overall magma plumbing, as defined by seismicity and pit craters, trends SE. Again a layered stress system is one interpretation, with seaward migration of the ERZ superposed on the plumbing connecting the summit magma reservoir with the ERZ. Clearly this area demands close scrutiny, since most of the magma erupted from Kilauea passes through the upper ERZ. Dikes also intrude the Koa`e fault system, which connects the active ERZ with the SWRZ. Faults and fractures in the Koa`e and ERZ have the same ENE fracture trend and structural style. Vents in the Koa`e occur ~6 km west of the ERZ. Deformation measurements show that magma intrudes the Koa`e during eruptions in the adjacent ERZ. What drives the magma to move so far from well established conduits? Once more, the observations raise more questions than answers.

[About Cryptophthalmos (2nd Czech Study)].

PubMed

Krásný, J; Čakrtová, M; Kletenský, J; Novák, V; Šach, J

To get acquainted with the 2nd Czech study about cryptophthamos and with self-surgical methods. The boy with unilateral complete cryptophthalmos of left eye was treated from 2 to 20 years. The girls was treated from 4 month to 5 year yet for right abortive cryptophthalmos with microblepharon and left complete type still waiting for solutions.Surgical methods and results: Authors present a surgical procedures for correction of the upper and lower eyelids and ocular anomalies both patients studied. Successful reconstruction of palpebral fissure took place in several stages at the boy. The surgical procedure gradually contained: the insertion of gradually increased convex concave circular-shaped implant (silicone ruber) due a modeling of palpebral fissure, an enucleation of rudimentary eye, a reconstruction of bottom palpebral fissure by retro-auricular skin graf and a releasing of the lower transitory fold by the cul-de-sac method. An adequate depth of palpebral fissure to allow perfect position of an aesthetic protesis. Enucleated eye was atypically shaped, remiding partly sand-glass clock. The cornea was replaced by thick fibrous membrane, the iris and the lens were not revealed. Gliomatic retina was detached nearly totaly and the optic nerv was rudimental. The repairing the upper lid coloboma of girl by a lid rotation flap reconstruction using the inferior eyelid was performed at the age 17 month. Corneal dermoid simultaneously removed (histologically verified). Upper conjunctival fornix was formed using the spherical covering foil (silicone rubber) before and after the reconstruction of the lid. Plastic reconstructions required the need for patient access without trying immediate effect. An important role played silicone rubber implants (elastomer medical grade) which used temporarily. cryptophthalmos, microblepharon, relief surgery, silicon ruber implants.

Supai salt karst features: Holbrook Basin, Arizona

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

Neal, J.T.

1994-12-31

More than 300 sinkholes, fissures, depressions, and other collapse features occur along a 70 km (45 mi) dissolution front of the Permian Supai Formation, dipping northward into the Holbrook Basin, also called the Supai Salt Basin. The dissolution front is essentially coincident with the so-called Holbrook Anticline showing local dip reversal; rather than being of tectonic origin, this feature is likely a subsidence-induced monoclinal flexure caused by the northward migrating dissolution front. Three major areas are identified with distinctive attributes: (1) The Sinks, 10 km WNW of Snowflake, containing some 200 sinkholes up to 200 m diameter and 50 mmore » depth, and joint controlled fissures and fissure-sinks; (2) Dry Lake Valley and contiguous areas containing large collapse fissures and sinkholes in jointed Coconino sandstone, some of which drained more than 50 acre-feet ({approximately}6 {times} 10{sup 4} m{sup 3}) of water overnight; and (3) the McCauley Sinks, a localized group of about 40 sinkholes 15 km SE of Winslow along Chevelon Creek, some showing essentially rectangular jointing in the surficial Coconino Formation. Similar salt karst features also occur between these three major areas. The range of features in Supai salt are distinctive, yet similar to those in other evaporate basins. The wide variety of dissolution/collapse features range in development from incipient surface expression to mature and old age. The features began forming at least by Pliocene time and continue to the present, with recent changes reportedly observed and verified on airphotos with 20 year repetition. The evaporate sequence along interstate transportation routes creates a strategic location for underground LPG storage in leached caverns. The existing 11 cavern field at Adamana is safely located about 25 miles away from the dissolution front, but further expansion initiatives will require thorough engineering evaluation.« less

Origins of feeding arteries of hepatocellular carcinoma located near the umbilical fissure of the left hepatic lobe: angiographic evaluation.

PubMed

Miyayama, Shiro; Yamashiro, Masashi; Shibata, Yoshihiro; Hashimoto, Masahiro; Yoshida, Miki; Tsuji, Kazunobu; Toshima, Fumihito; Matsui, Osamu

2012-12-01

To analyze the origins of the feeding arteries of hepatocellular carcinomas (HCCs) near the umbilical fissure of the left hepatic lobe. Twenty-eight HCCs with a mean ± SD tumor diameter of 3.4 ± 1.0 cm (range 1-4.4 cm) in contact with the right or left side of the umbilical fissure were treated by superselective transcatheter arterial chemoembolization (TACE). The origins of the tumor-feeding arteries were analyzed with arteriograms and computed tomography or cone-beam computed tomography images obtained during and 1 week after TACE. Twenty-one HCC lesions were located in segment 3 and seven were located in segment 4. Of 21 tumors in segment 3, 13 (61.9%) were supplied by the lateral inferior subsegmental artery (A3), three (14.3%) by the medial subsegmental artery (A4), three (14.3%) by both A4 and A3, one (4.8%) by a branch arising from the left lateral hepatic artery, and one (4.8%) by a branch of the right gastric artery. In particular, all tumor-feeding branches arising from A4 were the first branch of A4. Of seven tumors in segment 4, four (57.1%) were supplied by A4 and three (42.9%) by A3. In particular, all tumor-feeding branches arising from A3 were the first branch of A3. This study demonstrates crossover blood supply to HCC lesions located near the umbilical fissure, in addition to direct feeding from a separate branch. In particular, the first branch of the opposite subsegmental artery may feed tumors when crossover blood supply is present.

Non-destructive measurement of demineralization and remineralization in the occlusal pits and fissures of extracted 3rd molars with PS-OCT

NASA Astrophysics Data System (ADS)

Lee, Chulsung; Hsu, Dennis J.; Le, Michael H.; Darling, Cynthia L.; Fried, Daniel

2009-02-01

Previous studies have demonstrated that Polarization Sensitive Optical Coherence Tomography (PS-OCT) can be used to image the remineralization of early artificial caries lesion on smooth enamel surfaces of human and bovine teeth. However, most new dental decay is found in the pits and fissures of the occlusal surfaces of posterior dentition and it is in these high risk areas where the performance of new caries imaging devices need to be investigated. The purpose of this study was to demonstrate that PS-OCT can be used to measure the subsequent remineralization of artificial lesions produced in the pits and fissures of extracted 3rd molars. A PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of occlusal surfaces exposed to a demineralizing solution at pH-4.5 followed by a fluoride containing remineralizing solution at pH-7.0 containing 2-ppm fluoride. The integrated reflectivity was calculated to a depth of 200-µm in the entire lesion area using an automated image processing algorithm. Although a well-defined surface zone was clearly resolved in only a few of the samples that underwent remineralization, the PS-OCT measurements indicated a significant (p<0.05) reduction in the integrated reflectivity between the severity of the lesions that were exposed to the remineralization solution and those that were not. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth. These results show that PS-OCT can be used to non-destructively monitor the remineralization potential of anti-caries agents in the important pits and fissures of the occlusal surface.

Performance of some diagnostic systems in the prediction of occlusal caries in permanent molars in 6- and 11-year-old children.

PubMed

Fennis-Ie, Y L; Verdonschot, E H; van't Hof, M A

1998-01-01

Attempts have been made to develop diagnostic methods which enable an early diagnosis of occlusal lesions which are not detectable by visual inspection. The aim of this study was to compare the performance of visual inspection focused on finding signs of fissure decalcification and discoloration, visual inspection upon fibre-optic transillumination (FOTI), and electrical conductance measurements (ECMs) in predicting the onset of occlusal caries in 6- and 11-year-old children. Fifty children aged 5-7 and 11-15 years, having first or second permanent molar teeth that were not exposed to the oral environment for more than half a year, participated in the study. Following baseline data recording, the diagnostic measurements were repeated six times at 6-month intervals over a period of 2.5 years. Data were collected at predefined sites in the fissures. During the study, 220 of the 652 sites, i.e. 75 of 197 molars in 31 of the 50 children were judged to require a sealant or a sealant restoration. Two examiners jointly decided on the decay status at the sites. Survival plots showed that ECMs were superior to FOTI and fissure discoloration in predicting the onset of occlusal caries, although the differences were small. ECM is a better predictor of occlusal caries than fissure discoloration and FOTI, although the differences among the performance of the three methods in this study were very small. A cost-effective analysis is envisaged to obtain insight into the practical value of ECMs in the prediction of occlusal caries and, thus, into the effectiveness of sealant application.

The effect of pit and fissure sealants on the detection of occlusal caries in vitro.

PubMed

Manton, D J; Messer, L B

2007-03-01

To compare, in vitro, the effect of placing opaque (OPS) and clear fluorescing (CFS) pit and fissure sealants (PFS) on the detection of occlusal caries (OCD). Occlusal surfaces of 67 extracted molars were examined under standardised conditions by 6 final year undergraduate dental students, using visual, bitewing radiography, transillumination (FOTI), laser fluorescence (LF) and tactile methods of caries detection. The teeth were then assigned randomly to two groups for PFS placement: OPS and CFS; then the OCD methods were repeated. Caries presence/absence was determined histologically on serial sections examined under stereo-microscopy (10x). Before PFS placement the sensitivity and specificity for the OCD methods were: visual: 68%, 71%; radiographic: 15%, 95%; FOTI: 36%, 93%; LF: 49%, 83% and tactile: 39%, 67%, respectively. After placement of OPS, the sensitivity of LF (20%) and visual (13%) methods decreased and specificity increased (93%, 98% respectively). Placement of CFS resulted in minor changes in sensitivity and specificity. Correlation (Spearman's Rho coefficients) between OCD methods and histological intra-dentinal caries for pre- PFS, OPS, and CFS were: visual: 0.38, 0.34, 0.33; FOTI: 0.42, 0.35, 0.43; and LF: 0.41, 0.30, and 0.45 respectively. The sensitivity of all OCD methods was low, as well as their correlation to the histological gold standard. Placing OPS further decreased the sensitivity of LF and visual methods, whereas placing CFS had little effect on all OCD methods. It is recommended that tactile detection of occlusal caries should be discontinued, and the probe used only to clean the pits and fissures gently for more accurate visual detection, or prior to pit and fissure sealant placement. Further research into the development of an affordable, robust, accurate and easy to use method for OCD is required.

Origins of Feeding Arteries of Hepatocellular Carcinoma Located Near the Umbilical Fissure of the Left Hepatic Lobe: Angiographic Evaluation

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

Miyayama, Shiro, E-mail: s-miyayama@fukui.saiseikai.or.jp; Yamashiro, Masashi; Shibata, Yoshihiro

2012-12-15

Purpose: To analyze the origins of the feeding arteries of hepatocellular carcinomas (HCCs) near the umbilical fissure of the left hepatic lobe. Methods: Twenty-eight HCCs with a mean {+-} SD tumor diameter of 3.4 {+-} 1.0 cm (range 1-4.4 cm) in contact with the right or left side of the umbilical fissure were treated by superselective transcatheter arterial chemoembolization (TACE). The origins of the tumor-feeding arteries were analyzed with arteriograms and computed tomography or cone-beam computed tomography images obtained during and 1 week after TACE.ResultsTwenty-one HCC lesions were located in segment 3 and seven were located in segment 4. Ofmore » 21 tumors in segment 3, 13 (61.9%) were supplied by the lateral inferior subsegmental artery (A3), three (14.3%) by the medial subsegmental artery (A4), three (14.3%) by both A4 and A3, one (4.8%) by a branch arising from the left lateral hepatic artery, and one (4.8%) by a branch of the right gastric artery. In particular, all tumor-feeding branches arising from A4 were the first branch of A4. Of seven tumors in segment 4, four (57.1%) were supplied by A4 and three (42.9%) by A3. In particular, all tumor-feeding branches arising from A3 were the first branch of A3. Conclusion: This study demonstrates crossover blood supply to HCC lesions located near the umbilical fissure, in addition to direct feeding from a separate branch. In particular, the first branch of the opposite subsegmental artery may feed tumors when crossover blood supply is present.« less

Two novel de novo mutations of KRT6A and KRT16 genes in two Chinese pachyonychia congenita pedigrees with fissured tongue or diffuse plantar keratoderma.

PubMed

Du, Zhen-Fang; Xu, Chen-Ming; Zhao, Yan; Liu, Wen-Ting; Chen, Xiao-Ling; Chen, Chun-Yue; Fang, Hong; Ke, Hai-Ping; Zhang, Xian-Ning

2012-01-01

Mutations in the KRT6A or KRT16 gene cause pachyonychia congenita type 1 (PC-1), while mutations in KRT16 or KRT6C underlie focal palmoplantar keratoderma (FPPK). A new classification system of PC has been adopted based on the mutated gene. PC rarely presents the symptoms of diffuse plantar keratoderma. Mutation in the tail domain of keratins is rarely reported. PC combined with fissured tongue has never been described. To investigate the genotype-phenotype correlations between clinical features and gene mutational sites in two unrelated southern Chinese PC pedigrees (one family presented with specific fissured tongue, the other with diffuse plantar keratoderma). The whole coding regions of the KRT6A/KRT16/KRT17/KRT6B genes were amplified and directly sequenced to detect the mutation. To confirm the effect of the IVS8-2A>C mutation in KRT6A at the mRNA level, total RNA from the plantar lesion of a patient was extracted and reverse-transcribed to cDNA for sequence analysis. Two novel de novo mutations, a splice acceptor site variant IVS8-2A>C (p.S487FfsX72) in KRT6A and a heterozygous substitution c.AA373_374GG (p.N125G) within exon 1 of KRT16, were found separately in the two PC families. Genotype-phenotype correlations among PC patients with codon-125 mutation in KRT16 were established, while the phenotypes caused by the IVS8-2A>C mutation in KRT6A need further studies to confirm the rare feature of fissured tongue.

Assessment of microleakage of class V restored by resin composite and resin-modified glass ionomer and pit and fissure resin-based sealants following Er:YAG laser conditioning and acid etching: in vitro study

PubMed Central

Luong, Emilie; Shayegan, Amir

2018-01-01

Aim The aim of this study was to make a comparison between microleakage of conventionally restored class V cavities using acid etchant and the ones conditioned by erbium-doped yttrium aluminum garnet (Er:YAG) laser, and also to assess and compare the effectiveness of enamel surface treatments of occlusal pits and fissures by acid etching and conditioned by Er:YAG laser-etch. Materials and methods Seventy-two extracted third molars were used in this study. The samples were divided into two major groups: class V cavities and pit and fissure sealants. Each subgroup was divided into conventional acid etching, Er:YAG laser conditioning and conventional acid etching, and combination with Er:YAG laser conditioning (n=12). The teeth were placed in 2% methylene blue dye solution, were sectioned, and were evaluated according to the dye penetration criteria. Two samples per subgroup were chosen for scanning electron microscopic (SEM) analysis. Results There was a significant difference between occlusal and cervical margin groups. Laser conventional composite cementum group showed more microleakage values compared to other groups. There was no significant difference between occlusal margin groups. However, there was a significant difference between cervical margin groups in terms of microleakage. In sealant groups, there was a significant difference between laser and conventional with/without laser treatment groups in terms of microleakage. Conclusion Based on the results reported in this study, it can be concluded that the application of the Er:YAG laser beneath the resin composite, the resin-modified glass ionomers (GIs), and the fissure sealant placement may be an alternative enamel and dentin etching method to acid etching. PMID:29881311

Laser fluorescence of dentin caries covered with a novel nano-filled sealant.

PubMed

Braun, Andreas; Beisel, Christian; Brede, Olivier; Krause, Felix

2013-01-01

The aim of the present study was to assess the possibility to measure caries-induced laser fluorescence underneath a novel nano-filled fissure sealant. Sixty freshly extracted human teeth with occlusal dentine carious lesions were horizontally divided, exposing the respective lesion. Teeth were randomly assigned to three groups: (I) white fissure sealant with filler particles (Fissurit F, Voco), (II) clear fissure sealant without filler particles (Fissurit, Voco) and (III) novel experimental fissure sealant with nano-filler particles (Voco). Starting with a sealant thickness of 3 mm, laser fluorescence measurements (DIAGNOdent, KaVo) were performed after finishing the sealant surfaces with polishing papers, reducing the material at intervals of 0.5 mm until the sealant was removed completely. Evaluating a thickness of 0.5 mm, both the clear (83 % of the baseline fluorescence after fine grit polishing) and the white sealant (25 %) did not allow to measure baseline fluorescence (p < 0.05) with no fluorescence reduction in the experimental sealant group (p > 0.05). With increasing sealer thickness, fluorescence was influenced even by the experimental material (89 % of the baseline value at 1 mm). However, by using the experimental material, statistically significant higher fluorescence values than those for the other materials under study (p < 0.05) were obtained. Thicker sealant layers and coarse grit polishing caused a decrease of laser fluorescence in all groups (p < 0.05). Employing the experimental nano-filled sealant, laser fluorescence measurements for caries detection can be performed through thicker sealant layers compared to conventional sealant materials. Thus, it might be possible to use this material to assess a caries progression underneath the sealant and administer an appropriate therapy in due time.

Long-term outcomes of Botulinum toxin in the treatment of chronic anal fissure: 5 years of follow-up.

PubMed

Barbeiro, Sandra; Atalaia-Martins, Catarina; Marcos, Pedro; Gonçalves, Cláudia; Canhoto, Manuela; Arroja, Bruno; Silva, Filipe; Cotrim, Isabel; Eliseu, Liliana; Santos, Antonieta; Vasconcelos, Helena

2017-03-01

Chronic anal fissure is a frequent and disabling disease, often affecting young adults. Botulinum toxin and lateral internal sphincterotomy are the main therapeutic options for refractory cases. Botulinum toxin is minimally invasive and safer compared with surgery, which carries a difficult post-operative recovery and fecal incontinence risk. The long-term efficacy of Botulinum toxin is not well known. The aim of this study was to evaluate the long-term efficacy and safety of Botulinum toxin in the treatment of chronic anal fissure. This was a retrospective study at a single center, including patients treated with Botulinum toxin from 2005 to 2010, followed over at least a period of 5 years. All patients were treated with injection of 25U of Botulinum toxin in the intersphincteric groove. The response was registered as complete, partial, refractory and relapse. Botulinum toxin was administered to 126 patients, 69.8% ( n  = 88) were followed over a period of 5 years. After 3 months, 46.6% ( n  = 41) had complete response, 23.9% ( n  = 21) had partial response and 29.5% ( n  = 26) were refractory. Relapse was observed in 1.2% ( n  = 1) at 6 months, 11.4% ( n  = 10) at 1 year, 2.3% ( n  = 2) at 3 years; no relapse at 5 years. The overall success rate was 64.8% at 5 years of follow-up. Botulinum toxin was well tolerated by all patients and there were no complications. The use of Botulinum toxin to treat patients with chronic anal fissure was safe and effective in long-term follow-up.

Seismic processes and migration of magma during the Great Tolbachik Fissure Eruption of 1975-1976 and Tolbachik Fissure Eruption of 2012-2013, Kamchatka Peninsula

NASA Astrophysics Data System (ADS)

Fedotov, S. A.; Slavina, L. B.; Senyukov, S. L.; Kuchay, M. S.

2015-12-01

Seismic and volcanic processes in the area of the northern group of volcanoes (NGV) in Kamchatka Peninsula that accompanied the Great Tolbachik Fissure Eruption (GTFE) of 1975-1976 and the Tolbachik Fissure Eruption (TFE, or "50 let IViS" due to anniversary of the Institute of Volcanology and Seismology, Far East Branch, Russian Academy of Sciences) of 2012-2013 and the seismic activity between these events are considered. The features of evolution of seismic processes of the major NGV volcanoes (Ploskii Tolbachik, Klyuchevskoy, Bezymannyi, and Shiveluch) are revealed. The distribution of earthquakes along depth, their spatial and temporal migration, and the relation of seismic and volcanic activity are discussed. The major features of seismic activity during the GTFE preparation and evolution and a development of earthquake series preceding the origin of the northern and southern breaks are described. The character of seismic activity between the GTFE and TFE is shown. The major peculiarities of evolution of seismic activity preceding and accompanying the TFE are described. The major magma sources and conduits of the NGV volcanoes are identified, as is the existence of a main conduit in the mantle and a common intermediate source for the entire NGV, the depth of which is 25-35 km according to seismic data. The depth of a neutral buoyancy layer below the NGV is 15-20 km and the source of areal volcanism of magnesian basalts northeast of the Klyuchevskoy volcano is located at depth of ~20 km. These data support the major properties of a 2010 geophysical model of magmatic feeding system of the Klyuchevskoy group of volcanoes. The present paper covers a wider NGV area and is based on the real experimental observations.

Fluoride content and distribution pattern in groundwater of eastern Yunnan and western Guizhou, China.

PubMed

Luo, Kunli; Liu, Yonglin; Li, Huijie

2012-02-01

For study, the fluoride (F) content and distribution pattern in groundwater of eastern Yunnan and western Guizhou fluorosis area in southwestern China, the F content of 93 water samples [groundwater (fissure water, cool spring, and hot springs), rivers water] and 60 rock samples were measured. The result shows the F content of the fissure water and cold spring water is 0.027-0.47 mg/L, and river water is 0.048-0.224 mg/L. The F content of hot spring water is 1.02-6.907 mg/L. The drinking water supplied for local resident is mainly from fissure water, cool spring, and river water. And the F content in all of them is much lower than the Chinese National Standard (1.0 mg/L), which is the safe intake of F in drinking water. The infected people in eastern Yunnan and western Guizhou fluorosis area have very little F intake from the drinking water. The hot spring water in fluorosis area of eastern Yunnan and western Guizhou, southwest China has high F content, which is not suitable for drinking. © Springer Science+Business Media B.V. 2011

Evaluation of oral mucosal lesions in 598 referred Iranian patients.

PubMed

Jahanbani, Jahanfar; Sandvik, Leiv; Lyberg, Torstein; Ahlfors, Eva

2009-03-27

The mucosal membrane of the oral cavity displays at times classical developmental lesions considered to be variations of normal structures rather than having disease characteristics. Of these lesions leukoedema, Fordyce granules, geographic-, fissured- and hairy tongue, median rhomboid glossitis and lingual varices were studied in 598 patients referred to the School of Dentistry, Tehran, Iran. The prevalence was studied in relation to age, gender, occupation, education, smoking habits, general health, addictions and or drug therapies. Oral developmental lesions were seen in 295 patients (49.3%). Only Fordyce granules (27,9%), fissured tongue (12,9%), leukoedema (12,5%) and hairy tongue (8,9%) had enough cases for statistical analysis. Three of these lesions increased with age but not fissured tongue. All were more common in men. After adjusting for age, the parameters education, occupation and complaints upon referral had little influence on the prevalence of the lesions. Fewer Fordyce granules were seen in oral mucosa of smoking men. Leukoedema and hairy tongue were significantly associated with smoking, leukoedema with diabetes mellitus. We conclude that there was a highly significant association between these oral lesions and age, gender and smoking. Few significant associations were found between oral lesions and general diseases.

Normative findings for periocular anthropometric measurements among Chinese young adults in Hong Kong.

PubMed

Jayaratne, Yasas S N; Deutsch, Curtis K; Zwahlen, Roger A

2013-01-01

Measurement of periocular structures is of value in several clinical specialties including ophthalmology, optometry, medical and clinical genetics, oculoplastic surgery, and traumatology. Therefore we aimed to determine the periocular anthropometric norms for Chinese young adults using a noninvasive 3D stereophotography system. Craniofacial images using the 3dMDface system were acquired for 103 Chinese subjects (51 males and 52 females) between the ages of 18 and 35 years. Anthropometric landmarks were identified on these digital images according to standard definitions, and linear distances between these landmarks were calculated. It was found that ocular measurements were significantly larger in Chinese males than females for intercanthal width, biocular width, and eye fissure lengths. No gender differences were found in the eye fissure height and the canthal index which ranged between 43 and 44. Both right and left eye fissure height-length ratios were significantly larger in females. This is the first study to employ 3D stereophotogrammetry to create a database of anthropometric normative data for periocular measurements. These data would be useful for clinical interpretation of periocular pathology and serve as reference values when planning aesthetic and posttraumatic surgical interventions.

Lava flow hazards-An impending threat at Miyakejima volcano, Japan

NASA Astrophysics Data System (ADS)

Cappello, Annalisa; Geshi, Nobuo; Neri, Marco; Del Negro, Ciro

2015-12-01

The majority of the historic eruptions recorded at Miyakejima volcano were fissure eruptions that occurred on the flanks of the volcano. During the last 1100 years, 17 fissure eruptions have been reported with a mean interval of about 76-78 years. In the last century, the mean interval between fissure eruptions decreased to 21-22 years, increasing significantly the threat of lava flow inundations to people and property. Here we quantify the lava flow hazards posed by effusive eruptions in Miyakejima by combining field data, numerical simulations and probability analysis. Our analysis is the first to assess both the spatiotemporal probability of vent opening, which highlights the areas most likely to host a new eruption, and the lava flow hazard, which shows the probabilities of lava-flow inundation in the next 50 years. Future eruptive vents are expected in the vicinity of the Hatchodaira caldera, radiating from the summit of the volcano toward the costs. Areas more likely to be threatened by lava flows are Ako and Kamitsuki villages, as well as Miike port and Miyakejima airport. Thus, our results can be useful for risk evaluation, investment decisions, and emergency response preparation.

Characterising the biophysical properties of normal and hyperkeratotic foot skin.

PubMed

Hashmi, Farina; Nester, Christopher; Wright, Ciaran; Newton, Veronica; Lam, Sharon

2015-01-01

Plantar foot skin exhibits unique biophysical properties that are distinct from skin on other areas of the body. This paper characterises, using non-invasive methods, the biophysical properties of foot skin in healthy and pathological states including xerosis, heel fissures, calluses and corns. Ninety three people participated. Skin hydration, elasticity, collagen and elastin fibre organisation and surface texture was measured from plantar calluses, corns, fissured heel skin and xerotic heel skin. Previously published criteria were applied to classify the severity of each skin lesion and differences in the biophysical properties compared between each classification. Calluses, corns, xerotic heel skin and heel fissures had significantly lower levels of hydration; less elasticity and greater surface texture than unaffected skin sites (p < 0.01). Some evidence was found for a positive correlation between hydration and elasticity data (r ≤ 0.65) at hyperkeratotic sites. Significant differences in skin properties (with the exception of texture) were noted between different classifications of skin lesion. This study provides benchmark data for healthy and different severities of pathological foot skin. These data have applications ranging from monitoring the quality of foot skin, to measuring the efficacy of therapeutic interventions.

Glass ionomer ART sealant and fluoride-releasing resin sealant in fissure caries prevention – results from a randomized clinical trial

PubMed Central

2014-01-01

Background The relative performance of ART sealant and fluoride-releasing resin sealant in preventing fissure caries in permanent molars was compared in a randomized clinical trial conducted in southern China (ClinicalTrials.gov NCT01829334). Methods After obtaining ethical approval, healthy schoolchildren who had permanent first molars with occlusal fissures which were sound but deep or presented with only incipient caries were recruited for the study. Included molars were randomly allocated into one of four parallel study groups in units of left/right teeth per mouth. Two of the four groups adopted the methods of ART or fluoride-releasing resin sealant placement while the other two groups adopted the topical fluoride application methods. Fissure status of the molars in each group was evaluated every 6 months. Development of dentine caries and sealant retention over 24 months in the molars in the two sealant-using groups was compared in this report. Outcome on cost-effectiveness of all four groups over 36 months will be reported elsewhere. Results At baseline, a total of 280 children (383 molars) with mean age 7.8 years were involved for the two sealant groups. After 24 months, 261 children (357 molars) were followed. Proportions of molars with dentine caries were 7.3% and 3.9% in the ART sealant and fluoride-releasing resin sealant groups, respectively (chi-square test, p = 0.171). Life-table survival analysis showed that sealant retention (full and partial) rate over 24 months for the resin sealant (73%) was significantly higher than that (50%) for the ART sealant (p < 0.001). Molar survival (no development of dentine caries) rates in the ART sealant (93%) and fluoride-releasing resin sealant (96%) groups were not significantly different (p = 0.169). Multilevel logistic regression (GEE modeling) accounting for the effects of data clustering and confounding factors confirmed this finding. Conclusions Though the retention of fluoride-releasing resin sealant was better than that of the ART sealant, their effectiveness in preventing fissure caries in permanent molars did not differ significantly over 24 months. ART sealants could be a good alternative when and where resources for resin sealant placement are not readily available. PMID:24886444

Stone decay assessment of the Madrid's Royal Palace (Spain) by means of ultrasound and magnetometric prospection

NASA Astrophysics Data System (ADS)

Fort, R.; Alvarez de Buergo, M.

2012-04-01

The architrave of the entablature of the 4 façades of the Palace was built in a limestone known as Colmenar stone (biomicrite), a traditional material used for construction in Madrid. This stone shows such petrophysical properties that make it resistant to decay processes. Despite its high quality, the ashlars of the architrave have undergone fissuring processes resulting on fragments fall, some of them being blocks weighing more than 300 Kg, with the consequent risk for visitors and passers-by. Fissures were caused by the presence of metallic elements (iron-based) used to tie ashlars. These elements, which could have performed properly in absence of water, underwent oxidation processes due to the water entrance, exerting significant pressures inside the stone that derive into fractures with their planes being almost parallel to the façade surface. Once verified that the presence of these metallic elements, and their oxidation, was the cause of the ashlars fissuring, an inspection of the building façades architrave was performed by using two portable and non destructive techniques: magnetometry for detecting iron elements, and ultrasound velocity prospection for detecting non visible stone fissures behind the surface. This survey will allow defining the guidelines for a restoration intervention. The inspection of the architrave consisted of analysing around 1100 ashlars (circa 600 meters long were surveyed), during a lapse of time of one year, in 4 survey campaigns, one for each façade, with the aid of a mobile and self-operating that allows to reach up to 40 m high. Results from the magnetometry prospection made possible to locate metallic elements (flat bars and cramps), and sometimes the flat bars overlapping. Such bars are usually located at 3-5 cm deep from the surface, just below the freeze and in a case cut in the architrave limestone. In the areas of flat bars overlapping, a depth from the surface into the façade of 8-10 cm was measured. Such bars were several meters long, tieing several ashlars, from 55 to 65 mm wide, and 15-20 mm thick. In vaulted areas of the frieze, iron beams were detected, of around 9 cm thick, as well as iron angle bars behind the mentioned iron beams, vertically arranged and going through the architrave. The ultrasound propagation velocity survey in all the architrave ashlars was carried out by means of the indirect or surface mode, using a measuring net of 15 cm side and 20 to 30 readings in each element. Results obtained allowed detecting fissures inside the ashlars non visible at the stone surface. Main fissures were located in areas of cramp-stone coupling. Therefore, this technique was sucessful in locating architrave ashlars with risk of fall, and thus it made possible to plan the structural intervention to consolidate these elements by micro reinforcement with stainless materials (e.g. glass fiber).

[Surgical treatment for cicatrix strictures of anal canal].

PubMed

Pomazkin, V I; Mansurov, Iu V

2011-01-01

Classification of anal canal strictures with gradation of intensity, extent and localization is proposed. In 12 patients with compensated strictures combination of stenosis and anal fissure served as an indication for operation. These patients underwent fissure excision with dosed sphincterotomy. Anoplasty with displacement of island skin flaps to anal canal defects was carried out to 29 patients with sub-or decompensated strictures after dissection of scarry stricture. Good direct results were achieved in 38 patients. Compensated re-stenosis treated conservatively was observed in 3 patients after anoplasty. It is drawn a conclusion about necessity of differential approach to choice of treatment mode for anal scarry strictures. Anoplasty according to proposed method is considered to be optimal for marked strictures.

Diffusion of knowledge in dentistry. The pit and fissure sealant conferences.

PubMed

Chapko, M K

1988-01-01

This paper presents data on the diffusion to dentists of information from the May 1981 American Dental Association conference and December 1983 National Institutes of Health (NIH) conference on pit and fissure sealants. A mail survey was sent to 521 (72.2% returned) randomly selected dentists in general practice and all 47 (76.6% returned) pedodontists in the State of Washington. Approximately 70% of the dentists were aware that the conferences had taken place and a little over 50% were aware of the conference recommendations. Awareness was related to: being a pedodontist, number of continuing education hours taken, number of referred journals read, and being an officer in a dental organization.

A geochemical evaluation of the Ash Sha'ib mineral prospect, Asir quadrangle, Kingdom of Saudi Arabia

USGS Publications Warehouse

Allcott, Glenn H.

1970-01-01

The mineralized zone at the remotely located Ash Sha'ib ancient mine contains only a small tonnage of moderately low grade sulfide- bearing rock. Based on present data the gross value of the deposit, with a value of $25.00 or more per ton, is $20,000,000. A belt of metasedimentary rocks, intruded by gabbro to the south and granite to the north, was the host for fissure vein-replacement type mineralization. Most of the mineralization is in a siliceous dolomite transected by fissures. The main sulfide mineral is sphalerite, but minor amounts of chalcopyrlte and argentlferous galena contribute to the value of the mineralized sections.

Clinical and imaging features in lung torsion and description of a novel imaging sign.

PubMed

Hammer, Mark M; Madan, Rachna

2018-04-01

We set out to identify the clinical and imaging features seen in lung torsion, a rare but emergent diagnosis leading to vascular compromise of a lobe or entire lung. We retrospectively identified 10 patients with torsion who underwent chest CT. We evaluated each case for the presence of bronchial obstruction and abnormal fissure orientation. In seven patients who underwent contrast-enhanced CTs, we assessed for the presence of the antler sign, a novel sign seen on axial images demonstrating abnormal curvature of the artery and branches originating on one side. Five patients had right middle lobe (RML) torsion after right upper lobectomy, and the remaining occurred following thoracentesis, aortic surgery, or spontaneously. Chest CTs demonstrated bronchial obstruction in eight cases and presence of abnormal fissure orientation in four patients. The antler sign was present in three patients with whole-lung torsion and one patient with lobar torsion; vascular swirling was seen on 3-D images in all seven patients with contrast-enhanced CTs. Lung parenchymal imaging findings in lung torsion may be non-specific. Identification of the antler sign on contrast-enhanced chest CT, in combination with other signs such as bronchial obstruction and abnormal fissure orientation, indicates rotation of the bronchovascular pedicle. The presence of this sign should prompt further evaluation with 3-dimensional reconstructions.

Effect of occlusal calculus utilized as a potential "biological sealant" in special needs patients with gastric feeding tubes: a qualitative in vitro contrast to pit and fissure sealant restorations.

PubMed

Owens, Barry M; Sharp, Harry K; Fourmy, Emily E; Phebus, Jeffrey G

2016-01-01

The aim of this case report and in vitro investigation was to evaluate the marginal microleakage of intact occlusal calculus of primary molars extracted from a special needs patient who received nutrition via a gastric feeding tube. An adolescent with a history of developmental disturbance presented for routine dental care in a hospital facility. Prophylaxis was performed, and 2 mandibular permanent molars were restored. Five primary molars were extracted due to mobility and delayed retention. Heavy deposits of intact calculus were present on the occlusal surfaces of the primary teeth. The extracted teeth were immersed in methylene blue dye solution, invested in acrylic resin, sectioned into blocks, and photographed at 20× and 40× magnification. Previously photographed calculus-free molars with pit and fissure sealants were reviewed and served as contrasting "restorations." The occlusal calculus on the primary teeth extracted from the patient absorbed the dye, while the comparison teeth containing pit and fissure sealants exhibited varying degrees of marginal dye penetration (microleakage). No marginal microleakage was noted in the calculus specimens, indicating that this substrate may serve as a "natural" occlusal surface sealant and that its removal from occlusal surfaces during routine oral prophylaxis may be unnecessary.

Anal lesions presenting in a cohort of child gastroenterological examinations. Implications for sexual traumatic injuries.

PubMed

Rougé-Maillart, Clotilde; Houdu, Sora; Darviot, Estelle; Buchaillet, Céline; Baron, Céline

2015-05-01

The purpose of this study was to describe the anal lesions found in children during a pediatric gastroenterology consultation when the reason for the complaint was related to a digestive disease. This prospective descriptive study included 100 children under 15 years of age over a 13-month period, consulting due to digestive symptoms. The children were under 8 years old (90%) and 25% were under 3.1 years old. Constipation was the most frequent reason for consultation (69%). Fifty-one anal lesions were observed, of which 58.8% were anal fissures, 15.7% were skin tags and 5.8% were venous congestions related to straining. Anal fissures and skin tags were located at the median line, according to the clock-face method in supine position. No child had more than two anal lesions. No anal dilatation, sphincter hypotonia, anal scars, anal lacerations or bruises were found. The two most common anal lesions were anal fissures and skin tags. These anal lesions were mainly observed at the median line and were due to constipation. No cases of multiple anal lesions were found in terms of common digestive diseases. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Quantitative volcanic susceptibility analysis of Lanzarote and Chinijo Islands based on kernel density estimation via a linear diffusion process

PubMed Central

Galindo, I.; Romero, M. C.; Sánchez, N.; Morales, J. M.

2016-01-01

Risk management stakeholders in high-populated volcanic islands should be provided with the latest high-quality volcanic information. We present here the first volcanic susceptibility map of Lanzarote and Chinijo Islands and their submarine flanks based on updated chronostratigraphical and volcano structural data, as well as on the geomorphological analysis of the bathymetric data of the submarine flanks. The role of the structural elements in the volcanic susceptibility analysis has been reviewed: vents have been considered since they indicate where previous eruptions took place; eruptive fissures provide information about the stress field as they are the superficial expression of the dyke conduit; eroded dykes have been discarded since they are single non-feeder dykes intruded in deep parts of Miocene-Pliocene volcanic edifices; main faults have been taken into account only in those cases where they could modified the superficial movement of magma. The application of kernel density estimation via a linear diffusion process for the volcanic susceptibility assessment has been applied successfully to Lanzarote and could be applied to other fissure volcanic fields worldwide since the results provide information about the probable area where an eruption could take place but also about the main direction of the probable volcanic fissures. PMID:27265878

Quantitative volcanic susceptibility analysis of Lanzarote and Chinijo Islands based on kernel density estimation via a linear diffusion process.

PubMed

Galindo, I; Romero, M C; Sánchez, N; Morales, J M

2016-06-06

Risk management stakeholders in high-populated volcanic islands should be provided with the latest high-quality volcanic information. We present here the first volcanic susceptibility map of Lanzarote and Chinijo Islands and their submarine flanks based on updated chronostratigraphical and volcano structural data, as well as on the geomorphological analysis of the bathymetric data of the submarine flanks. The role of the structural elements in the volcanic susceptibility analysis has been reviewed: vents have been considered since they indicate where previous eruptions took place; eruptive fissures provide information about the stress field as they are the superficial expression of the dyke conduit; eroded dykes have been discarded since they are single non-feeder dykes intruded in deep parts of Miocene-Pliocene volcanic edifices; main faults have been taken into account only in those cases where they could modified the superficial movement of magma. The application of kernel density estimation via a linear diffusion process for the volcanic susceptibility assessment has been applied successfully to Lanzarote and could be applied to other fissure volcanic fields worldwide since the results provide information about the probable area where an eruption could take place but also about the main direction of the probable volcanic fissures.

Quantitative volcanic susceptibility analysis of Lanzarote and Chinijo Islands based on kernel density estimation via a linear diffusion process

NASA Astrophysics Data System (ADS)

Galindo, I.; Romero, M. C.; Sánchez, N.; Morales, J. M.

2016-06-01

Risk management stakeholders in high-populated volcanic islands should be provided with the latest high-quality volcanic information. We present here the first volcanic susceptibility map of Lanzarote and Chinijo Islands and their submarine flanks based on updated chronostratigraphical and volcano structural data, as well as on the geomorphological analysis of the bathymetric data of the submarine flanks. The role of the structural elements in the volcanic susceptibility analysis has been reviewed: vents have been considered since they indicate where previous eruptions took place; eruptive fissures provide information about the stress field as they are the superficial expression of the dyke conduit; eroded dykes have been discarded since they are single non-feeder dykes intruded in deep parts of Miocene-Pliocene volcanic edifices; main faults have been taken into account only in those cases where they could modified the superficial movement of magma. The application of kernel density estimation via a linear diffusion process for the volcanic susceptibility assessment has been applied successfully to Lanzarote and could be applied to other fissure volcanic fields worldwide since the results provide information about the probable area where an eruption could take place but also about the main direction of the probable volcanic fissures.

Evaluation of microtensile bond strength of different fissure sealants to bovine enamel.

PubMed

Sen Tunc, E; Bayrak, S; Tuloglu, N; Ertas, E

2012-03-01

The aim of this study was to evaluate the microtensile bond strength (μTBS) of a new fissure sealant and compare it with conventional sealants which are applied to enamel alone, and also with self-etch and etch-and-rinse adhesives. Enamel specimens were prepared and randomly distributed into three groups according to fissure sealant (Aegis, Helioseal F, Helioseal Clear). Each group was then subdivided according to adhesive system (Clearfil S3, Single Bond, no adhesive). A universal testing machine was used to measure μTBS, and data were analysed using one-way ANOVA and Tukey's tests. μTBS values for all Aegis subgroups were significantly lower than for comparable Helioseal F and Helioseal Clear subgroups (p < 0.05). No differences were observed in μTBS of Helioseal F and Helioseal Clear (p > 0.05). In the Helioseal Clear group, μTBS values for Single Bond were significantly higher than for Clearfil S3 (p < 0.05). However, no significant differences were found between the μTBS values of the adhesive subgroups in the Aegis or Helioseal F groups (p > 0.05). Sealant μTBS values may be affected by material content. The addition of an adhesive may improve μTBS values of sealant to enamel. © 2012 Australian Dental Association.

Remote sensing and petrological observations on the 2012-2013 fissure eruption at Tolbachik volcano, Kamchatka: Implications for reconstruction of the eruption chronology

NASA Astrophysics Data System (ADS)

Melnikov, Dmitry; Volynets, Anna O.

2015-12-01

We present a reconstruction of the chronological sequence of events that took place during the first days of the 2012-2013 Tolbachik fissure eruption using petrological data and remote sensing methods. We were forced to use this approach because bad weather conditions did not allow direct observations during the first two days of the eruption. We interpreted infrared images from the scanning radiometer VIIRS Suomi NPP and correlated the output with the results of the geochemical study, including comparison of the ash, deposited at the period from 27 to 29 November, with the samples of lava and bombs erupted from the Menyailov and Naboko vents. We argue that the compositional change observed in the eruption products (the decrease of SiO2 concentration and K2O/MgO ratio, increase of MgO concentration and Mg#) started approximately 24 h after the eruption began. At this time the center of activity moved to the southern part of the fissure, where the Naboko group of vents was formed; therefore, this timeframe also characterizes the timing of the Naboko vent opening. The Naboko group of vents remained active until the end of eruption in September 2013.

Effects of subpressure on the sealing ability of dental sealant in vitro.

PubMed

Tian, Y M; Zhuge, R S; Zhang, Z T; Zheng, D X; Ding, N; Li, Y M

2018-06-06

Pits and fissures sealing with flowable materials is a popular method for preventing caries in preventive dentistry while there is still microleakage existed. This in vitro study aimed to explore the effects of subpressure technique on the sealing ability of pit and fissure sealant. One hundred and forty-one extracted human premolars were collected in this study and treated with different pressure (atmosphere pressure as group C, -0.04 MPa as group S 4 and -0.08 MPa as group S 8 ). Thermocycling (×5000) was also performed. Penetration percentage, microleakage, cross-sectional microhardness (Knoop, KMH) and mineral loss were evaluated. Kappa tests, Friedman nonparametric and two-way ANOVA were used for data analysis. Penetration percentages of group S 4 and S 8 were significant higher compared to that of group C. Microleakage of groups was similar before thermocycling, while subpressure groups showed lower scale of microleakage after thermocycling. Data of KMH and mineral loss showed significant differences between subpressure and thermocycling groups. Subpressure technique could increase the penetration of pit and fissure sealant, decrease microleakage and increase resistance of demineralization after thermocycling. This novel technique may have great potential for preventing from secondary caries. Copyright © 2018 Elsevier Ltd. All rights reserved.

Safety and efficacy of new glyceryl trinitrate suppository formula: first double blind placebo-controlled clinical trial.

PubMed

Emami, M H; Sayedyahossein, S; Aslani, A

2008-07-01

This study was designed to assess the safety and efficacy of 0.2 percent glyceryl trinitrate suppository form in the healing of chronic anal fissure. Thirty-four patients with symptomatic chronic anal fissures were assigned to 0.2 percent glyceryl trinitrate suppository (n = 21) or placebo (n = 13) in a double blind design. Patient's symptom scores were registered at first visit. A validated daily chart was given to assess their symptoms on a daily basis. Both groups received psyllium from the beginning of the study. They were assessed at two-week intervals for six weeks. Then, they started a washout period of one month and after that were crossed over for another six weeks. Chi-squared, t-tests, and analysis of variance were used for statistical analysis. Complete healing at six weeks was achieved in 12 of 21 patients (57 percent) in the glyceryl trinitrate group and 5 of 13 patients (38 percent) in the placebo (P < 0.05). The overall healing rates at the end of study were 15 of 21 (71 percent) vs. 11 of 13 (84 percent) in the glyceryl trinitrate and placebo groups, respectively (P > 0.05). Application of 0.2 percent glyceryl trinitrate suppository form represents a new, promising, and effective treatment for chronic anal fissure.

Cascaded image analysis for dynamic crack detection in material testing

NASA Astrophysics Data System (ADS)

Hampel, U.; Maas, H.-G.

Concrete probes in civil engineering material testing often show fissures or hairline-cracks. These cracks develop dynamically. Starting at a width of a few microns, they usually cannot be detected visually or in an image of a camera imaging the whole probe. Conventional image analysis techniques will detect fissures only if they show a width in the order of one pixel. To be able to detect and measure fissures with a width of a fraction of a pixel at an early stage of their development, a cascaded image analysis approach has been developed, implemented and tested. The basic idea of the approach is to detect discontinuities in dense surface deformation vector fields. These deformation vector fields between consecutive stereo image pairs, which are generated by cross correlation or least squares matching, show a precision in the order of 1/50 pixel. Hairline-cracks can be detected and measured by applying edge detection techniques such as a Sobel operator to the results of the image matching process. Cracks will show up as linear discontinuities in the deformation vector field and can be vectorized by edge chaining. In practical tests of the method, cracks with a width of 1/20 pixel could be detected, and their width could be determined at a precision of 1/50 pixel.

[Evaluation of the effect of one-step self etching adhesives applied in pit and fissure sealing].

PubMed

Su, Hong-Ru; Xu, Pei-Cheng; Qian, Wen-Hao

2016-06-01

To observe the effect of three one-step self etching adhesive systems used in fit and fissure sealant and explore the feasibility of application in caries prevention in school. Seven hundred and twenty completely erupted mandibular first molars in 360 children aged 7 to 9 years old were chosen. The split-mouth design was used to select one side as the experimental group, divided into A1(Easy One Adper), B1(Adper Easy One), and C1(iBond SE).The contra lateral teeth served as A2,B2 and C2 groups (phosphoric acid). The retention and caries status were regularly reviewed .The clinical effect of the two groups was compared using SPSS19.0 software package for Chi - square test. At 3 and 6 months, pit and fissure sealant retention rate in A1 and A2, B1 and B2,C1 and C2 group had no significant difference. At 12 months, sealant retention in A1 and B1 group was significantly lower than A2 and B2 group (P<0.05). No significant difference was found between C1 and C2 groups (P>0.05). At 24 months, sealant retention rate in A1, B1 and C1 group was significantly lower than A2, B2 and C2 group (P<0.05). The caries rate in A1and A2, B1 and B2, C1 and C2 group had no significant difference during different follow-up time (P>0.05). The clinical anticariogenic effect of three kinds of one-step etching adhesives and phosphoric acid etching sealant was similar .One-step self etching adhesive system was recommended for pit and fissure sealant to improve the students' oral health. The long-term retention rate of one-step self etching adhesive system was lower than the phosphoric acid method to long term observation is needed.

Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

PubMed Central

Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

Objective We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Materials and Methods Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Results Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Conclusion Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung. PMID:21228937

Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

PubMed

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

Surface Deformation in Quetta Valley, Balochistan, Pakistan

NASA Astrophysics Data System (ADS)

Huang, J.; Shuhab, K.; Wulamu, A.; Crupa, W.; Khan, A. S.; Kakar, D. M.; Kasi, A.

2015-12-01

In February 2011, several ground fissures up to ~1.8 km in length appeared in the Quetta Valley, Balochsitan, Pakistan. It is not clear what caused the sudden occurrence of these fissures. The region is tectonically active and bounded to the west by several regional strike-slip faults including the north-south striking left-lateral Chaman fault system that slips at ~10 mm per year. Several large earthquakes have occurred recently in this area, one fatal 6.4 magnitude (Mw) earthquake occurred on October 28th, 2008. Some parts of Quetta Valley are subsiding; GPS data from two stations in Quetta that span mid-2006 - 2009 recorded subsidence rates of ~10 cm per year. Although subsidence in urban areas is generally attributed to groundwater depletion, it is not clear whether ground fissures are caused by water withdrawal or related to tectonics of the region. This study is designed to quantify and assess the source of surface deformation in Quetta Valley using InSAR, GPS, seismic and earthquake centroid moment tensor data. To detect and map the spatial-temporal features of the processes that led to the surface deformation, we used two time series, i.e., 15 European Remote Sensing (ERS-1/2) satellite images from 1992 - 1999 and 27 ENVISAT images spanning 2003 - 2010. A Differential Interferometric Synthetic Aperture Radar (DInSAR) Small Baseline Subset (SBAS) technique was used to investigate surface deformation. Eleven continuous-GPS stations within the InSAR antenna footprint were compared with the InSAR time series for quality control. Preliminary InSAR results revealed that the areas in and around the fissures are subsiding at 5 cm per year. Five seismic lines totaling ~60 km, acquired in 2003, were used to interpret faults beneath Holocene alluvium in the Quetta Valley. One of the blind faults is a north-south striking thrust fault mapped north into the Takatu range. However, a focal mechanism for the 2008 earthquake in this region indicated northwest-southeast strike-slip fault movement.

Campaign gravity results From kilauea volcano, hawaii, 2009-2011

NASA Astrophysics Data System (ADS)

Wilkinson, S. K.; Poland, M. P.; Battaglia, M.

2011-12-01

The gravity and leveling networks at Kilauea's summit caldera consist of approximately 60 benchmarks that are measured with a gravimeter as well as leveled for elevation data. Gravity data were collected in December 2009, June 2010 and March 2011. Elevation data were collected in 2009 and 2010. For the gravity survey completed in March 2011, we use InSAR and GPS data to assess elevation changes at the time of the gravity survey. During December 2009-March 2011, Kilauea's summit was characterized by minor deflation, following trends established in mid-2007. In mid-2010, however, the summit began to inflate, with a rate that increased significantly in October 2010. This inflation was associated with a decrease in the effusion rate from the volcano's east rift zone eruptive vents, suggesting that Kilauea's magma plumbing system was backing up. On March 5, 2011, a 2-km-long fissure eruption began about 3 km west of Pu`u `O`o, causing rapid summit deflation as magma drained from beneath the summit to feed the new eruptive vents. The fissure eruption ended on March 9, at which time the summit began to reinflate. Preliminary analysis of gravity data collected before and after the fissure eruption indicates a complex pattern of mass flow beneath the summit caldera. Net summit deformation was negligible between December 2009 and June 2010, but there is a residual gravity high centered near Halema'uma'u Crater. For the December 2009 to March 2011 time period, the caldera shows net subsidence. A positive residual gravity anomaly is located southeast of Halema'uma'u Crater while a negative residual gravity anomaly exists north of Halema'uma'u Crater. These patterns are somewhat unexpected, given the sudden draining of magma from beneath the summit during the March 5-9 fissure eruption. We conclude that the campaign gravity data were not collected at the optimal times to "catch" this event. Nevertheless, the data can still be used to assess different aspects of Kilauea's magma system.

Evidence-based clinical practice guideline for the use of pit-and-fissure sealants: A report of the American Dental Association and the American Academy of Pediatric Dentistry.

PubMed

Wright, John T; Crall, James J; Fontana, Margherita; Gillette, E Jane; Nový, Brian B; Dhar, Vineet; Donly, Kevin; Hewlett, Edmond R; Quinonez, Rocio B; Chaffin, Jeffrey; Crespin, Matt; Iafolla, Timothy; Siegal, Mark D; Tampi, Malavika P; Graham, Laurel; Estrich, Cameron; Carrasco-Labra, Alonso

2016-08-01

This article presents evidence-based clinical recommendations for the use of pit-and-fissure sealants on the occlusal surfaces of primary and permanent molars in children and adolescents. A guideline panel convened by the American Dental Association (ADA) Council on Scientific Affairs and the American Academy of Pediatric Dentistry conducted a systematic review and formulated recommendations to address clinical questions in relation to the efficacy, retention, and potential side effects of sealants to prevent dental caries; their efficacy compared with fluoride varnishes; and a head-to-head comparison of the different types of sealant material used to prevent caries on pits and fissures of occlusal surfaces. This is an update of the ADA 2008 recommendations on the use of pit-and-fissure sealants on the occlusal surfaces of primary and permanent molars. The authors conducted a systematic search in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and other sources to identify randomized controlled trials reporting on the effect of sealants (available on the US market) when applied to the occlusal surfaces of primary and permanent molars. The authors used the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the quality of the evidence and to move from the evidence to the decisions. The guideline panel formulated 3 main recommendations. They concluded that sealants are effective in preventing and arresting pit-and-fissure occlusal carious lesions of primary and permanent molars in children and adolescents compared with the nonuse of sealants or use of fluoride varnishes. They also concluded that sealants could minimize the progression of noncavitated occlusal carious lesions (also referred to as initial lesions) that receive a sealant. Finally, based on the available limited evidence, the panel was unable to provide specific recommendations on the relative merits of 1 type of sealant material over the others. These recommendations are designed to inform practitioners during the clinical decision-making process in relation to the prevention of occlusal carious lesions in children and adolescents. Clinicians are encouraged to discuss the information in this guideline with patients or the parents of patients. The authors recommend that clinicians reorient their efforts toward increasing the use of sealants on the occlusal surfaces of primary and permanent molars in children and adolescents. Copyright © 2016 American Academy of Pediatric Dentistry and American Dental Association. Published by Elsevier Inc. All rights reserved.

Anorectal abscess

MedlinePlus

Anal abscess; Rectal abscess; Perirectal abscess; Perianal abscess; Gland abscess; Abscess - anorectal ... of anorectal abscess include: Blocked glands in the anal area Infection of an anal fissure Sexually transmitted ...

Isolated nonpulsatile enophthalmos in neurofibromatosis: An uncommon entity

PubMed Central

Singh, Swati; Mulay, Kaustubh; Mittal, Vikas

2017-01-01

Isolated enophthalmos is a rarely observed entity in neurofibromatosis (NF). A 12-year-old male presented with right lower eyelid fat prolapse and enophthalmos for the past 7 years. There was no history of antecedent trauma/surgery. Computed tomography of orbit revealed an ill-defined intraconal hyperdense lesion located between lateral and inferior rectus along with an enlarged inferior orbital fissure (IOF). Superior orbital fissure was minimally widened without prolapse of any intracranial contents. Excision biopsy along with repair of widened IOF was performed through inferior transconjunctival route. Histopathology was suggestive of plexiform neurofibroma with positivity for S-100 and epithelial membrane antigen. No associated cutaneous lesions were present. Nonpulsatile enophthalmos with eyelid fat prolapse can be a presenting sign of NF. PMID:29044092

Isolated nonpulsatile enophthalmos in neurofibromatosis: An uncommon entity.

PubMed

Singh, Swati; Mulay, Kaustubh; Mittal, Vikas

2017-10-01

Isolated enophthalmos is a rarely observed entity in neurofibromatosis (NF). A 12-year-old male presented with right lower eyelid fat prolapse and enophthalmos for the past 7 years. There was no history of antecedent trauma/surgery. Computed tomography of orbit revealed an ill-defined intraconal hyperdense lesion located between lateral and inferior rectus along with an enlarged inferior orbital fissure (IOF). Superior orbital fissure was minimally widened without prolapse of any intracranial contents. Excision biopsy along with repair of widened IOF was performed through inferior transconjunctival route. Histopathology was suggestive of plexiform neurofibroma with positivity for S-100 and epithelial membrane antigen. No associated cutaneous lesions were present. Nonpulsatile enophthalmos with eyelid fat prolapse can be a presenting sign of NF.

[The management of 126 cases of posterior cracked crown of tooth and its effective observation].

PubMed

Chen, L L

2000-06-01

To detect the treatment and effect of posterior cracked tooth. 162 posterior cracked teeth of 158 cases, including enamel fissure and dentin fissure, all there cases undergone the synthetical treatment and follow up in different period, the longest observation period was 2.5 years. The healing and improved rate of 162 cracked teeth 90.74%. Among cases of failure, we have founded 6 cases of acute pulpitis (3.7%), 3 cases of alveodental abscess (1.85%), 2 cases of chronic apical periodontitis (1.24%), 4 cases of tooth fracture (2.4%). Cracked tooth was caused by multiple factors. Early diagnosis, synthetical treatment, and follow up in different period are 3 main factors in treatment.

Method for laser drilling subterranean earth formations

DOEpatents

Shuck, Lowell Z.

1976-08-31

Laser drilling of subterranean earth formations is efficiently accomplished by directing a collimated laser beam into a bore hole in registry with the earth formation and transversely directing the laser beam into the earth formation with a suitable reflector. In accordance with the present invention, the bore hole is highly pressurized with a gas so that as the laser beam penetrates the earth formation the high pressure gas forces the fluids resulting from the drilling operation into fissures and pores surrounding the laser-drilled bore so as to inhibit deleterious occlusion of the laser beam. Also, the laser beam may be dynamically programmed with some time dependent wave form, e.g., pulsed, to thermally shock the earth formation for forming or enlarging fluid-receiving fissures in the bore.

A model of the plumes above basaltic fissure eruptions

NASA Astrophysics Data System (ADS)

Woods, Andrew W.

1993-06-01

A simple model of the ascent of the volatiles above basaltic fissure eruptions shows that atmospheric moisture may play an important role in injecting volatiles high into the atmosphere. As ambient water vapor is entrained and carried upwards by the plume, it decompresses and some condensation may occur. This causes the release of latent heat which heats up the air and thereby increases the buoyancy of the plume enabling it to ascend several kilometers higher than in a dry atmosphere. The height of such plumes also increases with the mass fraction of fine ash in the fountain. Although very simple, the model predictions are in accord with observations of plume heights during historical eruptions including the 1984 eruption of Mauna Loa.

Magma chamber deflation recorded by the Global Positioning System - The Hekla 1991 eruption

NASA Astrophysics Data System (ADS)

Sigmundsson, Freysteinn; Einarsson, Pall; Bilham, Roger

1992-07-01

Between January 17 and March 11, 1991, 0.15 cu km of lava erupted initially from several radial fissures and subsequently from a single fissure on the SE flank of Hekla volcano, Iceland. Hekla is surrounded by an array of control points measured in 1989 using GPS geodesy and re-measured after the eruption. These measurements indicate that the eruption was associated with a surface deflation volume of 0.1 + 0.08 - 0.04 centered on Hekla (63.995 deg N +4 -3 km, 19.69 deg W +1.5 -2 km). The depth to the magma reservoir is 9 +6 -7 km, poorly constrained due to the absence of GPS control points close to the volcano.

Black Psyllium

MedlinePlus

... in the skin around the anus (anal fissures), surgery on the rectum, and pregnancy. It is also used for diarrhea, dysentery, irritable bowel syndrome (IBS), reducing high cholesterol, and treating cancer.

Influence of etching time and bonding strategies on the microshear bond strength of self- and light-cured pit-and-fissure sealants.

PubMed

Souza-Junior, Eduardo José; Borges, Boniek Castillo Dutra; Montes, Marcos Antônio Japiassú Resende; Alonso, Roberta Caroline Bruschi; Ambrosano, Glaucia Maria Bovi; Sinhoreti, Mário Alexandre Coelho

2012-01-01

This study evaluated the impact of extended etching and bonding strategies on the microshear bond strength of three sealant materials. Two pit-and-fissure sealants [FluroShield, Dentsply (light-cured) and AlphaSeal, DFL (self-cured)] and one light-cured flowable composite resin (Permaflo, Ultradent) were evaluated according to different enamel etching times (15 s or 30 s) and bonding procedures (no adhesive application, application of primer/hydrophobic resin or hydrophobic resin only). Intact enamel blocks were obtained from bovine teeth and sealed via the tested protocols. After 24 h, the microshear bond strength test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were classified by stereomicroscopy. Data were submitted to a three-way ANOVA and to Tukey's test (α=0.05). There was no statistically significant difference (p>0.05) among the materials. Permaflo showed higher bond strength when etched for 30 s alone. Enamel overetching decreased the bond strength of the light-cured sealant. Primer/bond previous treatment improved bond performance for AlphaSeal. In conclusion, from the tested conditions, all sealant materials presented similar bond strength values in relation to bonding protocol and etching time. The flowable composite can be used as a pit-and-fissure sealant. The use of a three-step adhesive system was essential for the self-cured sealant application.

Damage from the El Mayor-Cucapah earthquake, April 2010: Why society cannot afford to ignore seismic risks to agricultural regions

NASA Astrophysics Data System (ADS)

Stenner, H. D.; Mathieson, E. L.; Okubo, S.; Anderson, R.; Rodriguez C., M. A.

2010-12-01

The M7.2 El Mayor-Cucapah earthquake of April 4, 2010 in Mexico’s Baja California caused extensive damage to the agricultural area of Mexicali Valley. The damage included wide-spread liquefaction and lateral spreading which destroyed or damaged irrigation canals. Without water, wheat, alfalfa, and other crops were lost. Fields were cut by fissures and partially buried by massive sand blows. Regional tilting from the earthquake was a serious issue for the gravity-controlled irrigation system. Ruptured canals and groundwater from sand blows flooded fields, roads, and towns. Flooding further damaged crops and brought contamination with it. Fissures and scarps through farm communities cracked buildings; ruptured water, sewer, and other pipelines; and made roads temporarily difficult to pass. Economically, farmers, seasonal farm workers, and agricultural suppliers were affected; reducing their ability to consume the goods and services of businesses unrelated to agriculture. Similar damage was observed in earlier earthquakes over the past 100 years. Society quickly forgets how the earth responds to strong shaking. We hope to provide a vivid portrait of this agricultural disaster so that other farming communities prone to strong seismic shaking may visualize what can happen from their own inevitable future earthquake. Fissure and sand blows southeast of Cucapah, Baja California, April 16, 2010. Heavily damaged irrigation canal northwest of Zacamoto, Baja California, April 15, 2010.

Study of texture stitching in 3D modeling of lidar point cloud based on per-pixel linear interpolation along loop line buffer

NASA Astrophysics Data System (ADS)

Xu, Jianxin; Liang, Hong

2013-07-01

Terrestrial laser scanning creates a point cloud composed of thousands or millions of 3D points. Through pre-processing, generating TINs, mapping texture, a 3D model of a real object is obtained. When the object is too large, the object is separated into some parts. This paper mainly focuses on problem of gray uneven of two adjacent textures' intersection. The new algorithm is presented in the paper, which is per-pixel linear interpolation along loop line buffer .The experiment data derives from point cloud of stone lion which is situated in front of west gate of Henan Polytechnic University. The model flow is composed of three parts. First, the large object is separated into two parts, and then each part is modeled, finally the whole 3D model of the stone lion is composed of two part models. When the two part models are combined, there is an obvious fissure line in the overlapping section of two adjacent textures for the two models. Some researchers decrease brightness value of all pixels for two adjacent textures by some algorithms. However, some algorithms are effect and the fissure line still exists. Gray uneven of two adjacent textures is dealt by the algorithm in the paper. The fissure line in overlapping section textures is eliminated. The gray transition in overlapping section become more smoothly.

Effects of the New Madrid earthquake series in the Mississippi Alluvial Valley. Final report

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

Saucier, R.T.

1977-02-01

Geological effects of the New Madrid earthquake series of 1811-12 in the upper portion of the Lower Mississippi Valley include land subsidence, uplift or doming, landslides, bank caving, fissuring, and sand blow phenomena. Features resulting from the liquefaction of sand are widespread in the alluvial valley and offer the greatest potential for definitively assessing the effects of major earthquakes on thick alluvial deposits and predicting the recurrence interval of infrequent major earthquakes in the region. However, liquefaction phenomena have not been the subject of detailed geological investigations applying knowledge of alluvial morphology and earth sciences methodology. Comparative aerial photo interpretationmore » has been used to classify liquefaction phenomena according to morphology, distribution, and relationship to major depositional environments. Surface morphology and spatial distribution of sand blows and fissures indicate basic control by drainage lines, water table position, and thickness of fine-grained topstratum deposits, Research efforts have been aimed at locating field test sites where the subsurface expression of the liquefaction phenomena can be investigated through trenching and land planing. Subsurface expression is presumed to be more permanent than surface expression and may permit the recognition of such features in older formations. Evidence of fissures and related phenomena is being sought in older Quaternary deposits to permit estimates of the frequency of past major earthquakes.« less

Sylvian Fissure Asymmetries in Nonhuman Primates Revisited: A Comparative MRI Study

PubMed Central

Hopkins, William D.; Pilcher, Dawn L.; MacGregor, Leslie

2007-01-01

Magnetic resonance images (MRI) were collected in a sample of 28 apes, 16 Old World monkeys and 8 New World monkeys. The length of the sylvian fissure (SF) and the superior temporal sulcus (STS) was traced in each hemisphere from three regions of the cerebral cortex. These three regions were labeled according to their position on the sagittal plane as lateral, medial and insular. It was hypothesized that the length and asymmetry of these fissures would be dependent on the region of measurement and that a leftward asymmetry in the SF and STS would be more robust in the great ape sample than for the monkeys. The results indicated within the ape sample a population-level leftward asymmetry in the medial and insular regions of the SF. Within the Old and New World monkey samples, the SF was leftward in the medial region at the population level, but not at the insular region. Additionally, the Old World monkeys exhibited a population-level rightward lateral SF and a rightward lateral STS. No other families exhibited population-level asymmetries in the lateral region of the SF or in any region of the STS. These results are consistent with findings reported in apes and, to a lesser extent, monkeys. MRI has excellent potential for comparing neuroanatomy across taxonomic families that will help future investigations. PMID:11326134

Hiccups

MedlinePlus

... Mentioned In This Article Medical Dictionary Also of Interest (Quiz) Anal Fissure (News) Don't Fret Delays ... to switch to the Professional version Also of Interest Test your knowledge Which of the following is ...

Anoscopy

MedlinePlus

... What Abnormal Results Mean Abnormal results may include: Abscess Fissures Foreign object in the anus Hemorrhoids Infection ... Wechter, MD, FACS, general surgery practice specializing in breast cancer, Virginia Mason Medical Center, Seattle, WA. Also ...

Anal Fissure

MedlinePlus

... Career Center DC&R Journal Access Member Directory Mentor Match Educational Resources American Board of Colon and ... Media Policy Corporate Partners Contact Us Media Center Mentor Match Disclaimer ASCRS Product Store Donate to ASCRS ...

Gastrointestinal bleeding

MedlinePlus

... conditions that are not serious, including: Anal fissure Hemorrhoids GI bleeding may also be a sign of ... the bowel Home Care There are home stool tests for microscopic blood that may be recommended for ...

Anal fissure

MedlinePlus

... Kliegman RM, Stanton BF, St. Geme JW, Schor NF. Surgical conditions of anus and rectum. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, ...

[Cerebellar atrophy in Minamata disease: comparison with spino-cerebellar degeneration on MR images].

PubMed

Ikeda, O; Okajima, T; Korogi, Y; Kitajima, M; Uchino, M; Takahasi, M

1997-02-01

We evaluated atrophic patterns of the cerebellar vermis in seven patients with Minamata disease (MD) and nine patients with spino-cerebellar degeneration (SCD) on MR images. Twenty-five control subjects were also examined. The cerebellar vermis was divided into superior, middle, and inferior parts by the primary fissure and the prepyramidal fissure on the median sagittal T1-weighted MR image. The length and area of each part were measured. In the patients with SCD, there were no significant differences in the degree of atrophy among the three parts. However, MR images of the patients with MD showed more severe atrophy in the middle and inferior parts than in the superior part. Atrophy of the superior part was less frequently observed in MD patients.

A chronology of Late-Pleistocene permafrost events in southern New Jersey, eastern USA

USGS Publications Warehouse

French, H.M.; Demitroff, M.; Forman, S.L.; Newell, Wayne L.

2007-01-01

Frost fissures, filled with wind-abraded sand and mineral soil, and numerous small-scale non-diastrophic deformations, occur in the near-surface sediments of the Pine Barrens of southern New Jersey. The fissures are the result of thermal-contraction cracking and indicate the previous existence of either permafrost or seasonally-frozen ground. The deformations reflect thermokarst activity that occurred when permafrost degraded, icy layers melted and density-controlled mass displacements occurred in water-saturated sediments. Slopes and surficial materials of the area reflect these cold-climate conditions. Optically-stimulated luminescence permits construction of a tentative Late-Pleistocene permafrost chronology. This indicates Illinoian, Early-Wisconsinan and Late-Wisconsinan episodes of permafrost and/or deep seasonal frost and a Middle-Wisconsinan thermokarst event. Copyright ?? 2007 John Wiley & Sons, Ltd.

Gigantic self-confined pahoehoe inflated lava flows in Argentina

NASA Astrophysics Data System (ADS)

Pasquare', G.; Bistacchi, A.

2007-05-01

The largest lava flows on Earth are pahoehoe basalts emplaced by inflation, a process which can change lava lobes initially a few decimetres thick into large lava sheets several metres thick. Inflation involves the initial formation of a thin, solidified, viscoelastic crust, under which liquid lava is continually added. This thermally efficient endogenous growth process explains the spread of huge volumes of lava over large, almost flat areas, as in the sheet flows which characterise the distal portions of Hawaiian volcanoes or some continental flood basalt provinces. Long, narrow, inflated pahoehoe flows have occasionally been described, either emplaced along pre-existing river channels or confined within topographic barriers. In this contribution we present previously unknown inflated pahoehoe lava flows following very long, narrow pathways over an almost flat surface, with no topographic confinement. Lava, which erupted in Late Quaternary times from the eastern tip of a 60 km long volcanic fissure in Argentina, formed several discrete flows extending as far as 180 km from the source. This fissure was characterized by a long-lasting and complex activity. Alkali-basaltic lava flows were emitted at the two extremities of the fissure system. In the intermediate section of the fissure, the Payun Matru, a great trachitic composite volcano, developed, giving rise to a large caldera which produced large pyroclastic flows. Alkali-basalts predate and postdate the trachitic activity, in fact at the end of the trachitic activity, new basaltic lava flows (mainly aa) were emitted from both ends of the fissure. We studied in details the youngest of the gigantic flows (Pampas Onduladas lava flow), which progressively develops through differing thermally-efficient flow mechanisms. The flow created a large shield volcanic structure at the eastern tip of the E-W fissure and spread to the E forming a very large and thick inflated pahoehoe sheet flow. Leaving the flanks of the volcano, the flow spreads all over a large tectonic depression, forming a large inflated pahoehoe sheet flow. The flow continues downstream, always showing typical inflation features, forming a very long and narrow tongue, developed over the nearly flat Pampa plain (gradient 0.5%) with an average width of 3 km and a length of 120 km. A peculiar feature of this portion of the flow, apart from its exceptional length, is the very low width-to-length ratio. This is even more surprising if we consider that no pre-existing topographic feature (e.g. river channel, etc.) is responsible for this behaviour, which appears to be only the result of some kind of self-confinement mechanism. The structural, morphological and eruptive complexities of this volcanic structure are exceptional by themselves since there are no similar features both in the Andes calcalkaline volcanism or in the Patagonian basaltic plateaus and they pose problems even in the nomenclatural definition of the Payun Matru as an individual volcanic construct. Moreover, understanding the mechanisms responsible for the exceptional behaviour of this lava flow may provide new constraints on the physics of inflated pahoehoe flow emplacement. Results in this direction may also offer useful proxies for interpreting volcanic processes on terrestrial planets such as Mars and Venus, on which individual lava flows of similar shape and dimensions have been observed.

Kilauea's Ongoing Eruption: 25th Year Brings Major Changes

NASA Astrophysics Data System (ADS)

Orr, T. R.

2007-12-01

2007 marks the 25th year of nearly continuous eruption on Kilauea's east rift zone. Episodic high lava fountains, which built the Pu`u `O`o cone during the first three years of the eruption, ended in 1986. Activity then migrated downrift and the Kupaianaha shield was formed by passive effusion of lava. The change in eruptive style resulted in a switch at Pu`u `O`o from cone construction to cone collapse that has been ongoing for the last two decades. Activity at Kupaianaha ceased in 1992, and the eruption resumed at Pu`u `O`o. The eruptive style established at Kupaianaha continued, however, with continuous effusion from vents on the southwest flank of the Pu`u `O`o cone. The last 15 years have been characterized by the formation of relatively stable tube systems---broken only by a brief fissure eruption uprift of Pu`u `O`o in 1997---that have carried lava from the flank vents to the ocean about 9 km away. The Prince Kuhio Kalanianaole (PKK) tube, the most recent of these tube systems to develop, was active from March 2004 to June 2007. The PKK flow was emplaced almost entirely on older flows of this eruption and entered the ocean in several locations over a span of 6 km. The "Father's Day" intrusion of June 17--19, 2007, robbed the supply of magma to Pu`u `O`o and, thus, the active flow field. The floor of the Pu`u `O`o crater dropped 80--100 m, the PKK tube system drained, and the active flows and ocean entry quickly stagnated. On June 19, a short-lived fissure eruption broke out low on the east flank of Kane Nui o Hamo, about 6 km uprift of Pu`u `O`o, burying only 0.22 hectares. The eruption at Kilauea paused from June 20 through July 1 or 2, when lava returned to Pu`u `O`o and began refilling the collapsed crater. Near midnight on July 20--21, after at least 19 days of lava lake growth, the lava pond within the Pu`u `O`o crater drained suddenly when a series of fissures opened on the east flank of the cone and propagated ~2 km downrift. The new activity, dubbed the July 21 eruption, initially fed `a`a and pahoehoe flows but, within a few days, developed into a system of perched lava ponds. By the end of July, the perched pond over the easternmost fissure evolved into an open channel feeding a series of `a`a flows heading downrift around the north side of the Kupaianaha shield. The lava supply from other fissure segments declined and stagnated within a few days of the lava channel's formation. As of September 4, 2007, `a`a flows have extended up to ~6 km from the fissure and have covered more than 600 hectares. Unless the eruption supply rate increases, `a`a flows fed by the open channel will likely travel no more than a few kilometers from the vent and pose no threat to those living downslope. If the eruptive style changes, however, to one characterized by tube-fed pahoehoe, then downslope communities could be directly impacted.

3D model of fault and fissures structure of the Kovdor Baddeleyite-Apatite-Magnetite Deposit (NE of the Fennoscandian Shield)

NASA Astrophysics Data System (ADS)

Zhirov, Dmitry; Klimov, Sergey

2015-04-01

The Kovdor baddeleyite-apatite-magnetite deposit (KBAMD) is represented by a large vertical ore body and is located in the southwestern part of the Kovdor ultramafic-alkaline central-type intrusion. The intrusion represents a concentrically zoned complex of rocks with an oval shape in plan, and straight zoning, which complies with the injection and displacement of each of further magma phases from the center towards the periphery. The operation of the deposit in open pits started in 1962, and nowadays, it has produced over 500,000,000 tons of ore. This is one of the largest open pits in the Kola region, which is ca. 2 km long, 1.8 km wide, and over 400 m deep. Regular structural studies has been carried out since late 1970. A unique massif of spatial data has been accumulated so far to include over 25,000 measurements of fissures and faults from the surface, ca. 20,000 measurements of fissures in the oriented drill core (over 18 km) etc. Using this data base the 3D model of fault and fissures structure was designed. The analysis of one has resulted in the identification of a series of laws and features, which are necessary to be taken into account when designing a deep open pit and mining is carried out. These are mainly aspects concerning the origin, kinematics, mechanics and ratio of spatial extension of various fault systems, variation of their parameters at deep horizons, features of a modern stress field in the country rocks, etc. The 3D model has allowed to divide the whole fracture / fissure systems of the massif rocks into 2 large groups: prototectonic system of joints, including cracks of 'liquid magmatic (carbonatite stage) contraction genesis', and newly formed faults due to the superimposed tectonic stages. With regard to the deposit scale, these are characterized as intraformational and transformational, respectively. Each group shows a set (an assemblage) of fault systems with unique features and signs, as well as regular interconnections. The prototectonic assemblage of fissures includes the following main systems: 2-3 subsystems Rd of radial with angle of dip within 65-90° (median at 78°), two subsystems S of a circular subvertical (tangential, crossing Rd) with angle of dip within 60-90° (74°), and two diagonal-conic ones: a centriclinal C dipping towards the center of the intrusion at angles of 25-55° (43°), and a periclinal P dipping from the center of the intrusion at angles of 5-35° (18°). The system of subhorizontal joints L (angle of dip within 0-12°) at deep horizons is insignificantly manifested. All the prototectonic systems are regularly interrelated, and vary asymuthal features according to the law of axial symmetry (when moving around the vertical axis of symmetry passed through the geometric center of the carbonatite intrusion). The superimposed tectonics of post-ore stages forms a few large faults and systems of rupture discontinuities. A few (up to 3) variously oriented displacements are documented in the field on kinematic features (slide furrows, oriented cleavages). They were used for reconstruction of stresses and tectonic evolution. The superimposed tectonic faulting has heterogeneous (local) distribution in the rocks of the deposit, and slight predictability of main parameters. This study was supported by the Russian Scientific Fund (project nos. 14-17-00751).

Fluid regimes during late stages of a continental collision: Physical, chemical, and stable isotope measurements of fluid inclusions in fissure quartz from a geotraverse through the Central Alps, Switzerland

NASA Astrophysics Data System (ADS)

Mullis, Josef; Dubessy, Jean; Poty, Bernard; O'Neil, James

1994-05-01

Fluid evolution during neo-alpine metamorphism during late stages of the continental collision between Europe and Africa was studied by analyzing fluid inclusions in alpine fissure quartz collected in forty-nine localities along a geotraverse through the Central Alps, Switzerland. The methods employed include microthermometry, micro-Raman spectroscopy, K/Na thermometry, and stable isotope analysis. Early fluid inclusions provide evidence of close to peak metamorphic temperatures of the late Tertiary or neo-alpine metamorphic event. Fluid composition evolved along the geotraverse from north to south as follows: higher hydrocarbons were dominant in the low- and medium-grade diagenetic zones, methane was the main volatile in the high-grade diagenetic and low-grade anchizone, water dominated in the highgrade anchizone and low-grade epizone, with CO2 > 10 mol% in the high-grade epizone and in the mesozone. Higher hydrocarbons and CH 4 were the products of kerogen maturation and cracking of preexisting petroleum. Large water supplies originated from the dehydration of cooler metasedimentary rocks that were overthrust by crystalline basements of the Lepontines, Aar, and Gotthard massifs. Carbon isotope analyses suggest that the CO 2 component was derived from oxidation of graphitic matter, especially in the vicinity of sulfate-bearing metasediments and from decarbonation reactions. In the Aar and Gotthard massifs as well as in the Helvetic Axen nappe and its underlying North Helvetic flysch, high fluid pressures prevailed and favored nappe transport. By contrast, in the southern Lepontine area, very low early fluid pressures were probably related to dry rocks and scarce metasediments, and to high geothermal gradients that resulted from intense uplift and erosion between 26 and 18 Ma. Retrograde fluid evolution was recorded by a succession of fluid inclusion populations in each alpine fissure. It was controlled by uplift and cooling and characterized by decreasing contents of volatiles and an increase in δ 18O of host quartz. Tectonic activity led to episodic pressure drops of at least 0.5 to 2 kbar and promoted fluid unmixing, channelized flow, and rapid growth of skeletal quartz. Channelized rather than pervasive fluid migration at temperatures < 450° C and under conditions of brittle deformation is documented by episodic increases in salinity and by fluid flushing through the massifs. There is stable isotope evidence for involvement of meteoric water only in late-crystallizing quartz. Formation of Alpine fissures and fissure minerals was the result of a unique coincidence of late continental collision (< 450° C), fluid expulsion from overthrust metasediments, uplift, and erosion.

Physical simulation and theoretical evolution for ground fissures triggered by underground coal mining

PubMed Central

Yu, Xiang; Yang, Yi; Yang, Zeng-Qiang

2018-01-01

Underground coal mining activities are prone to cause movement and breakage in geological strata and also lead to mining subsidence and even ground fissures. Along the direction working panel advancing, ground fissures may occur in roof in front and/or behind working panel. However, the investigations of previous similarity tests in lab only emphasize on the region behind working panel. By improving strata material property in construction and mounting artificial pressure devices, two physical simulation tests were conducted and successfully investigated the simulated results. Then, the mechanical model of “cantilever beam and elastic foundation beam” was proposed to calculate the stress distribution and the crack initiation angle in overlying strata and it well explains the mechanisms of ground fissures generation and propagation. Results show that, the maximum internal force in roof always occurred in front of working panel. However, because the void space in gob due to excavation is large enough to cause the bend and rotation of roof strata, compare to the triaxially compressed region in front of working panel, the roof always broke off at some positions above gob since the stress concentration resulting from such bend and rotation of strata could easily reach the limit strength of strata rocks. Also, the length of cantilever beam changed dynamically as respect to the panel advancing and the breakage intervals. Thus, the breakage position where the internal force first reached the limit tensile strength is not fixed and there will be two different kinds of relative positions between the crack initiation point and the working panel. The crack initiation direction is always perpendicular to the internal force, and the crack propagation direction is affected by the initiation angle, overburden-separation degree and the position of the hydraulic shields. If there is no overburden-separation or less, the roofs will break off as a composite beam and the propagation direction will be roughly along the central line between the initial broken point and the support position. Otherwise, the roof strata will bend with the support shields moving forward, then the fracture angle will be close to the initiation angle and the fault surface will be stepped. PMID:29513703

Applying psychological theories to evidence-based clinical practice: identifying factors predictive of placing preventive fissure sealants.

PubMed

Bonetti, Debbie; Johnston, Marie; Clarkson, Jan E; Grimshaw, Jeremy; Pitts, Nigel B; Eccles, Martin; Steen, Nick; Thomas, Ruth; Maclennan, Graeme; Glidewell, Liz; Walker, Anne

2010-04-08

Psychological models are used to understand and predict behaviour in a wide range of settings, but have not been consistently applied to health professional behaviours, and the contribution of differing theories is not clear. This study explored the usefulness of a range of models to predict an evidence-based behaviour -- the placing of fissure sealants. Measures were collected by postal questionnaire from a random sample of general dental practitioners (GDPs) in Scotland. Outcomes were behavioural simulation (scenario decision-making), and behavioural intention. Predictor variables were from the Theory of Planned Behaviour (TPB), Social Cognitive Theory (SCT), Common Sense Self-regulation Model (CS-SRM), Operant Learning Theory (OLT), Implementation Intention (II), Stage Model, and knowledge (a non-theoretical construct). Multiple regression analysis was used to examine the predictive value of each theoretical model individually. Significant constructs from all theories were then entered into a 'cross theory' stepwise regression analysis to investigate their combined predictive value. Behavioural simulation - theory level variance explained was: TPB 31%; SCT 29%; II 7%; OLT 30%. Neither CS-SRM nor stage explained significant variance. In the cross theory analysis, habit (OLT), timeline acute (CS-SRM), and outcome expectancy (SCT) entered the equation, together explaining 38% of the variance. Behavioural intention - theory level variance explained was: TPB 30%; SCT 24%; OLT 58%, CS-SRM 27%. GDPs in the action stage had significantly higher intention to place fissure sealants. In the cross theory analysis, habit (OLT) and attitude (TPB) entered the equation, together explaining 68% of the variance in intention. The study provides evidence that psychological models can be useful in understanding and predicting clinical behaviour. Taking a theory-based approach enables the creation of a replicable methodology for identifying factors that may predict clinical behaviour and so provide possible targets for knowledge translation interventions. Results suggest that more evidence-based behaviour may be achieved by influencing beliefs about the positive outcomes of placing fissure sealants and building a habit of placing them as part of patient management. However a number of conceptual and methodological challenges remain.

Physical simulation and theoretical evolution for ground fissures triggered by underground coal mining.

PubMed

Yang, Jing-Hu; Yu, Xiang; Yang, Yi; Yang, Zeng-Qiang

2018-01-01

Underground coal mining activities are prone to cause movement and breakage in geological strata and also lead to mining subsidence and even ground fissures. Along the direction working panel advancing, ground fissures may occur in roof in front and/or behind working panel. However, the investigations of previous similarity tests in lab only emphasize on the region behind working panel. By improving strata material property in construction and mounting artificial pressure devices, two physical simulation tests were conducted and successfully investigated the simulated results. Then, the mechanical model of "cantilever beam and elastic foundation beam" was proposed to calculate the stress distribution and the crack initiation angle in overlying strata and it well explains the mechanisms of ground fissures generation and propagation. Results show that, the maximum internal force in roof always occurred in front of working panel. However, because the void space in gob due to excavation is large enough to cause the bend and rotation of roof strata, compare to the triaxially compressed region in front of working panel, the roof always broke off at some positions above gob since the stress concentration resulting from such bend and rotation of strata could easily reach the limit strength of strata rocks. Also, the length of cantilever beam changed dynamically as respect to the panel advancing and the breakage intervals. Thus, the breakage position where the internal force first reached the limit tensile strength is not fixed and there will be two different kinds of relative positions between the crack initiation point and the working panel. The crack initiation direction is always perpendicular to the internal force, and the crack propagation direction is affected by the initiation angle, overburden-separation degree and the position of the hydraulic shields. If there is no overburden-separation or less, the roofs will break off as a composite beam and the propagation direction will be roughly along the central line between the initial broken point and the support position. Otherwise, the roof strata will bend with the support shields moving forward, then the fracture angle will be close to the initiation angle and the fault surface will be stepped.

Three-dimensional flow and trace metal mobility in shallow Chalk groundwater, Dorset, United Kingdom

NASA Astrophysics Data System (ADS)

Schürch, Marc; Edmunds, W. Michael; Buckley, David

2004-06-01

The three-dimensional groundwater flow and the hydrogeochemical regime have been determined in the Bere Stream valley, North Dorset Downs, southern England. The dual porosity characteristics of the Portsdown Chalk have been established using geophysical and hydrochemical borehole logging. Chemical properties have been established using major and trace element analyses of depth samples and groundwaters. The study site is located at the unconfined-confined boundary of the Chalk aquifer, where it is overflowing in the observation boreholes. The Chalk dips locally at about 5 m/km to the south-east under Palaeogene confining beds and three distinctive flow horizons may be recognised. The Chalk groundwater is of Ca-HCO 3 type and three separate geochemical groundwater zones were also determined with depth, having different oxygen levels and trace element characteristics. (1) A shallow O 2-rich zone with around 80% dissolved O 2 and low trace element concentrations. (2) A mixing and transition zone with significant concentrations of trace elements and high trace metal concentrations at its base: manganese 29 μg/l, nickel 55 μg/l, cadmium 146 μg/l, and zinc 214 μg/l. (3) A deeper zone with depleted oxygen (5-20% dissolved O 2) and with longer water residence times shown by higher Mg/Ca and K/Na ratios as well as higher Sr and F. The groundwater geochemistry in the Chalk aquifer is dominated by incongruent reactions with the fine-grained carbonate sediments, which release trace element impurities to the water. Some of the metals are co-precipitated with Mn- and Fe-oxide phases on fissure surfaces, whilst producing a purer calcite. During subsequent recrystallisation to purer iron- and manganese-oxides on fissure surfaces under specific geochemical and hydrodynamic conditions, trace metals are released into the fissure water. The results demonstrate the need to monitor quality stratification and the changes in the groundwater baseline chemistry in areas close to the redox boundary which, in the dual porosity Chalk is likely to be a diffuse zone with exchange between oxygen poor matrix waters and more oxic water flowing through the fissures.

Video monitoring reveals pulsating vents and propagation path of fissure eruption during the March 2011 Pu'u 'Ō'ō eruption, Kilauea volcano

NASA Astrophysics Data System (ADS)

Witt, Tanja; Walter, Thomas R.

2017-01-01

Lava fountains are a common eruptive feature of basaltic volcanoes. Many lava fountains result from fissure eruptions and are associated with the alignment of active vents and rising gas bubbles in the conduit. Visual reports suggest that lava fountain pulses may occur in chorus at adjacent vents. The mechanisms behind such a chorus of lava fountains and the underlying processes are, however, not fully understood. The March 2011 eruption at Pu'u 'Ō'ō (Kilauea volcano) was an exceptional fissure eruption that was well monitored and could be closely approached by field geologists. The fissure eruption occurred along groups of individual vents aligned above the feeding dyke. We investigate video data acquired during the early stages of the eruption to measure the height, width and velocity of the ejecta leaving eight vents. Using a Sobel edge-detection algorithm, the activity level of the lava fountains at the vents was determined, revealing a similarity in the eruption height and frequency. Based on this lava fountain time series, we estimate the direction and degree of correlation between the different vents. We find that the height and velocity of the eruptions display a small but systematic shift in time along the vents, indicating a lateral migration of lava fountaining at a rate of 11 m/s from W to E. This finding is in agreement with a propagation model of a pressure wave originating at the Kilauea volcano and propagating through the dyke at 10 m/s from W to E. Based on this approach from videos only 30 s long, we are able to obtain indirect constraints on the physical dyke parameters, with important implications for lateral magma flow processes at depth. This work shows that the recording and analysis of video data provide important constraints on the mechanisms of lava fountain pulses. Even though the video sequence is short, it allows for the confirmation of the magma propagation direction and a first-order estimation of the dyke dimensions.

Radiologic evaluation of vasculobiliary anatomy in the umbilical fissure.

PubMed

Ji, Gu-Wei; Zhu, Fei-Peng; Wang, Ke; Xia, Yong-Xiang; Jiao, Chen-Yu; Shao, Zi-Cheng; Li, Xiang-Cheng

2017-06-15

Preoperative evaluation of vasculobiliary anatomy in the umbilical fissure (U-point) is pivotal for perihilar cholangiocarcinoma (PCCA) applied to right-sided hepatectomy. The purpose of our study was to review the vasculobiliary anatomy in the U-point using three-dimensional (3D) reconstruction technique, to investigate the diagnostic ability of 2D scans to evaluate anatomic variations, and to discuss its surgical implications. A retrospective study of 159 patients with Bismuth type I, II, and IIIa PCCA, who received surgery at our institution from November 2012 to September 2016, was conducted. Anatomic structures were assessed using multidetector computed tomography (MDCT) by one hepatobiliary surgeon, whereas 3D images were reconstructed by an independent radiologist. Normal confluence pattern of left biliary system was defined as the left medial segmental bile duct (B4) joining the common trunk of segment II (B2) and segment III (B3) ducts, whereas aberrant confluence patterns were classified into 3 types: type I, triple confluence of B2, B3, and B4; type II, B2 draining into the common trunk of B3 and B4; type III, other patterns. Surgical anatomy of B4 was classified into the central, peripheral, and combined type according to its relation to the hepatic confluence. The lengths from the bile duct branch of Spiegel's lobe (B1l) to the orifice of B4 and the junction of B2 and B3 were measured on 3D images. The anatomy of left hepatic artery (LHA) was classified according to different origins and the spatial relationship related to the U-point. 3D reconstruction revealed that normal confluence pattern of left biliary system was observed in 71.1% (113/159) of all patients, and variant patterns were type I in 11.9% (19/159), type II in 12.6% (20/159), and type III in 4.4% (7/159). The length from B1l to the junction of B2 and B3 was 12.1 ± 3.1 mm in type I variation, which was significantly shorter than that in normal configuration (30.0 ± 6.8 mm, P < 0.001) but significantly longer than that in type II variation (9.6 ± 3.4 mm, P = 0.019). Surgical anatomy of B4: the peripheral type was most commonly seen (74.2%, 118/159), followed by central type (15.7%, 25/159) and combined type (10.1%, 16/159). The distance between the B1l and B4 was 8.4 ± 2.4 mm in central and combined type, which was significantly shorter than that in peripheral type (14.5 ± 4.1 mm, P < 0.001). A replaced or accessory LHA from the left gastric artery was present in 6 (3.8%) and 9 (5.7%) patients, respectively. LHA running along the left caudal position of U-point was present in 143 cases (89.9%), along the right cranial position of U-point in nine cases (5.7 %), and combined position in seven cases (4.4%). Interobserver agreement of two imaging modalities was almost perfect in biliary confluence pattern (kappa = 0.90; 95% confidence interval: 0.79-1.00), substantial in surgical anatomy of B4 (kappa = 0.74; 95% confidence interval: 0.62-0.86), and perfect in LHA (kappa = 1.00). Thoroughly understanding the imaging characters of surgical anatomy in the U-point may be benefit for preoperative evaluation of PCCA by successive review of 2D images alone, whereas 3D reconstruction technique allows detailed hepatic anatomy and individualized surgical planning for advanced cases. Copyright © 2017 Elsevier Inc. All rights reserved.

Anal Fissures

MedlinePlus

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Fissure near Cerberus Fossae with Tectonic Morphologies

NASA Image and Video Library

2014-01-15

The linearity of the volcanic vent shown in this image observed by NASA Mars Reconnaissance Orbiter, in conjunction with evidence of lava flow from the vent, suggests control by combined volcano-tectonic processes.

Fissured Tongue

MedlinePlus

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Cortical and diencephalic lesions in Korsakoff's syndrome: a clinical and CT scan study.

PubMed

Jacobson, R R; Lishman, W A

1990-02-01

Twenty-five male alcoholic Korsakoff patients were compared with age and sex-matched non-Korsakoff chronic alcoholics and healthy volunteers on clinical and CT brain scan parameters. The scans were assessed by planimetry, visual grading procedures and computerized analysis. Reliable measures of third ventricular size were developed. The Korsakoff patients had wider third ventricles, larger lateral ventricles and wider interhemispheric fissures than the comparison groups; but sulcal and Sylvian fissure widths were equivalent in Korsakoff and non-Korsakoff alcoholics. The results suggest that, in addition to their well-established diencephalic lesions, many Korsakoff patients have sustained widespread cerebral damage. Shrinkage in the frontal brain regions appears to be especially pronounced. The implications for a dual aetiology of alcoholic Korsakoff's syndrome involving thiamine deficiency and features associated with alcoholism, probably direct alcohol neurotoxicity, are discussed.

Knowledge, value, opinion and practice about usage of pit and fissure sealant among dental professionals in Chennai, Tamil Nadu, India.

PubMed

Nagappan, N; Dhamodhar, M Dinesh; Nithin, M G; Kumar, E Senthil

2015-12-01

A study was aimed to assess the knowledge, value, opinion, and practice regarding the use of dental sealants among private dental practitioners in Chennai, Tamil Nadu, India. A self-administrated questionnaire were distributed to 192 private dental practitioners in Chennai, Tamil Nadu, India by using simple random sampling. A convenience sampling technique was employed. The questionnaire consisted of 28 items, which included information about knowledge, value, opinion, and practice regarding dental sealants. The questionnaire was obtained from the study by San Martin et al. 2013 and Kailash Asawa et al. 2014. Frequency distribution was tabulated. For frequency distribution strongly, strongly agree, and agree were combined as "agree" and strongly disagree and disagree were combined as "disagree." There were no changes in "neutral." Among the 196 study subjects 56.2% were males and 43.8% were females with their clinical experience of 52.1% for <5 years, 35.4% for 5-10 years, and 13.5% for >15 years. The mean scores for knowledge, value, opinion, and practice were 41.8 ± 3.7, 18.7 ± 2.8, 18.1 ± 1.4, and 12.9 ± 2.3, respectively. The results suggest that dental practitioners had satisfactory knowledge about pit and fissure sealant and had neutral attitudes about sealants being effective. Dental practitioners adequately used the pit and fissure sealants but they did not follow the standardized procedures and specific guidelines.

The modified Ottawa method to establish the update need of a systematic review: glass-ionomer versus resin sealants for caries prevention

PubMed Central

MICKENAUTSCH, Steffen; YENGOPAL, Veerasamy

2013-01-01

Objective To demonstrate the application of the modified Ottawa method by establishing the update need of a systematic review with focus on the caries preventive effect of GIC versus resin pit and fissure sealants; to answer the question as to whether the existing conclusions of this systematic review are still current; to establish whether a new update of this systematic review was needed. Methods: Application of the Modified Ottawa method. Application date: April/May 2012. Results Four signals aligned with the criteria of the modified Ottawa method were identified. The content of these signals suggest that higher precision of the current systematic review results might be achieved if an update of the current review were conducted at this point in time. However, these signals further indicate that such systematic review update, despite its higher precision, would only confirm the existing review conclusion that no statistically significant difference exists in the caries-preventive effect of GIC and resin-based fissure sealants. Conclusion In conclusion, this study demonstrated the modified Ottawa method as an effective tool in establishing the update need of the systematic review. In addition, it was established that the conclusions of the systematic review in relation to the caries preventive effect of GIC versus resin based fissure sealants are still current, and that no update of this systematic review was warranted at date of application. PMID:24212996

A clinical trial to evaluate the retention of a silver cermet-ionomer cement used as a fissure sealant.

PubMed

Mills, R W; Ball, I A

1993-01-01

A randomized clinical trial was under-taken to compare the retention of a silver cermet-ionomer cement, Ketac Silver, with a conventional, autopolymerizing BIS-GMA resin sealant, Delton, using matched pairs of fissure sites within each subject's mouth. One hundred twenty matched contralateral pairs of fissure sites in first and second permanent molars of 53 school children were sealed with the two materials. The choice of site and material was selected at random. The ages of the children ranged from five to 16 years; first permanent molars were sealed in the five- to 10-year age group, and second permanent molars in the 11- to 16-year age group. Sealants were assessed as present, partly present, or absent at 6, 12, and 24 months. The number of pairs of sites available for reassessment declined from 102 at six months to 59 at 24 months as patients were lost to the study. Retention rates were higher for the Ketac Silver sealants at all three inspection intervals (P < 0.01): 93% compared with 74% at six months, 81% compared with 65% at 12 months, and 83% compared with 58% at 24 months. When analyzed according to age range, the difference between the retention rates was statistically significant in the five- to 10-year-olds but not significant in the 11- to 16-year-olds. The conclusion reached in this study was that cermet cement was better retained than conventional resin sealants in younger children.

Evaluation of the remineralization potential of amorphous calcium phosphate and fluoride containing pit and fissure sealants using scanning electron microscopy.

PubMed

Choudhary, Prashant; Tandon, Shobha; Ganesh, M; Mehra, Anshul

2012-01-01

To evaluate the remineralization potential of Amorphous Calcium Phosphate (ACP) and Fluoride containing pit and Fissure Sealants using Scanning Electron Microscopy. Thirty maxillary first premolars were divided into three groups of ten each and were randomly selected for ACP containing (Aegis- Opaque White, Bosworth Co. Ltd.), Fluoride containing (Teethmate F1 Natural Clear, Kuraray Co. Ltd.), resin based (Concise- Opaque White, 3M ESPE Co. Ltd.) pit and fissure sealant applications. The Concise group served as a control. The teeth weresubjected to the pH-cycling regimen for a period of two weeks. After two weeks, the teeth were sectioned bucco-lingually into 4mm sections and were observed under Scanning Electron Microscope at 50X, 250X, 500X, 1000X and 1500X magnifications. The qualitative changes at the tooth surface and sealant interface were examined and presence of white zone at the interface was considered positive for remineralization. Both ACP containing (Aegis) and Fluoride containing (Teethmate F1) group showed white zone at the tooth surface-sealant interface. The resin based group (Concise) showed regular interface between the sealant and the tooth structure, but no clear cut white zone was observed. Both, Aegis and Teethmate F1 have the potential to remineralize. Release of Amorphous Calcium Phosphate molecules in Aegis group and formation of Fluoroapetite in Teethmate F1 group, were probably responsible for the remineralization.

Volcano-tectonics of the Al Haruj Volcanic Province, Central Libya

NASA Astrophysics Data System (ADS)

Elshaafi, Abdelsalam; Gudmundsson, Agust

2016-10-01

The Al Haruj intra-continental Volcanic Province (AHVP), located at the south-western margin of the Sirt Basin, hosts the most extensive and recent volcanic activity in Libya - which is considered typical for plate interiors. From north to south the AHVP is divided into two subprovinces, namely Al Haruj al Aswad and Al Haruj al Abiyad. The total area of the AHVP is around 42,000 km2. Despite the great size of the AHVP, its volcano-tectonic evolution and activity have received very little attention and are poorly documented and understood. Here we present new field data, and analytical and numerical results, on the volcano-tectonics of the AHVP. The length/thickness ratio of 47 dykes and volcanic fissures were measured to estimate magmatic overpressure at the time of eruption. The average dyke (length/thickness) ratio of 421 indicates magmatic overpressures during the associate fissure eruptions of 8-19 MPa (depending on host-rock elastic properties). Spatial distributions of 432 monogenetic eruptions sites/points (lava shields, pyroclastic cones) in the AHVP reveal two main clusters, one in the south and another in the north. Aligned eruptive vents show the dominating strike of volcanic fissures/feeder-dykes as WNW-ESE to NW-SE, coinciding with the orientation of one of main fracture/fault zones. Numerical modelling and field observations suggest that some feeder-dykes may have used steeply dipping normal-fault zones as part of their paths to the surface.

Can extended photoactivation time of resin-based fissure sealer materials improve ultimate tensile strength and decrease water sorption/solubility?

PubMed

Borges, Boniek Castillo Dutra; Souza-Júnior, Eduardo José; Catelan, Anderson; Paulillo, Luís Alexandre Maffei Sartini; Aguiar, Flávio Henrique Baggio

2012-10-01

This study aimed to evaluate the impact of extended photoactivation time on ultimate tensile strength (UTS), water sorption (WS) and solubility (WSB) of resin-based materials used as fissure-sealants. A fissure-sealant (Fluroshield) and a flowable composite (Permaflo) polymerized for 20 and 60 seconds were tested. For UTS, 20 hourglass shaped samples were prepared representing two materials and two photoactivation time (n=5). After 24-h dry-storage, samples were tested in tension using a universal testing machine at a cross-head speed of 0.5 mm/min (UTS was calculated in MPa). For WS and WSB, 20 disks with 5 mm diameter and 1 mm height (n=5) were prepared and volumes were calculated (mm(3)). They were transferred to desiccators until a constant mass was obtained (m1) and were subsequently immersed in distilled water until no alteration in mass was detected (m2). Samples were reconditioned to constant mass in desiccators (m3). WS and WSB were determined using the equations m2-m3/V and m1-m3/V, respectively. Data were subjected to two-way ANOVA and Tukey's HSD test (P<.05). There was no significant difference between materials or photoactivation times for the UTS and WS. Permaflo presented lower but negative WSB compared to Fluroshield. Extended photoactivation time did not improve the physical properties tested. Fluroshield presented physical properties that were similar to or better than Permaflo.

Oral mucosal lesions in older people: relation to salivary secretion, systemic diseases and medications.

PubMed

Lynge Pedersen, A M; Nauntofte, B; Smidt, D; Torpet, L A

2015-09-01

To determine the prevalence of oral mucosal lesions in a sample of older Danish people and to investigate their associations with age, gender, systemic diseases, medications, xerostomia and salivary secretion. A total of 668 community-dwelling individuals aged 65-95 years underwent a clinical examination, measurements of unstimulated and stimulated whole and labial salivary flow rates and an interview regarding xerostomia, general health, medication, tobacco and alcohol habits. Seventy-five per cent of all participants and 70% of the non-medicated ones had one or more oral mucosal lesions. The most prevalent lesions were lingual varicosities (28.3%), denture stomatitis (12.7%), candidiasis (11.8%), fissured tongue (9.1%) and frictional keratosis (8.4%). Lesions were generally associated with smoking and xerostomia. Varicosities were more common in participants with systemic diseases and medication intake, particularly with cardiovascular diseases and agents. Fissured tongue and atrophic tongue were associated with female gender, xerostomia and low unstimulated whole and labial salivary secretion. Oral candidiasis was associated with older age; being male; current smoker; having >3 diseases, intake of medications and low salivary flow rates; and identified in relation to denture stomatitis, fissured tongue and atrophic tongue and median rhomboid glossitis. Oral mucosal lesions are prevalent in older Danish people and generally associated with changes in both local and systemic factors. Tongue lesions in particular appeared as indicators that may identify patients with specific need of oral intervention. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Surface deformation in volcanic rift zones

USGS Publications Warehouse

Pollard, D.D.; Delaney, P.T.; Duffield, W.A.; Endo, E.T.; Okamura, A.T.

1983-01-01

The principal conduits for magma transport within rift zones of basaltic volcanoes are steeply dipping dikes, some of which feed fissure eruptions. Elastic displacements accompanying a single dike emplacement elevate the flanks of the rift relative to a central depression. Concomitant normal faulting may transform the depression into a graben thus accentuating the topographic features of the rift. If eruption occurs the characteristic ridge-trough-ridge displacement profile changes to a single ridge, centered at the fissure, and the erupted lava alters the local topography. A well-developed rift zone owes its structure and topography to the integrated effects of many magmatic rifting events. To investigate this process we compute the elastic displacements and stresses in a homogeneous, two-dimensional half-space driven by a pressurized crack that may breach the surface. A derivative graphical method permits one to estimate the three geometric parameters of the dike (height, inclination, and depth-to-center) and the mechanical parameter (driving pressure/rock stiffness) from a smoothly varying displacement profile. Direct comparison of measured and theoretical profiles may be used to estimate these parameters even if inelastic deformation, notably normal faulting, creates discontinuities in the profile. Geological structures (open cracks, normal faults, buckles, and thrust faults) form because of stresses induced by dike emplacement and fissure eruption. Theoretical stress states associated with dilation of a pressurized crack are used to interpret the distribution and orientation of these structures and their role in rift formation. ?? 1983.

Wear of two pit and fissure sealants in contact with primary teeth

PubMed Central

Galo, Rodrigo; Contente, Marta Maria Martins Giamatei; Borsatto, Maria Cristina

2014-01-01

Objectives: Wear simulations may provide an indication of the clinical performance of pit-and-fissure sealants when associated with primary teeth as counterbody, restricting the involved variables. The aim of this study was to evaluate wear of dental materials used as pit-and-fissure sealants in contact with primary teeth. Materials and Methods: A resinous sealant (Fluroshield®) and a resin-modified glass ionomer cement (Vitremer®) were selected in a post-plate design, using as counterbody primary tooth pins (4 × 4 × 2 mm) at 3 and 10 N vertical load, 1 Hz frequency, 900 wear cycles in artificial saliva (n = 15). Attrition coefficient values were obtained and the material and primary tooth volumes were analyzed. Data were analyzed statistically by ANOVA and Duncan's test (P < 0.05). Results: Fluroshield® presented the highest attrition coefficient values for the 3 N but these values decreased significantly for the 10 N load. The means for volume loss (3 mm) of the different samples after the wear test were not statistically different for the materials. The volume loss values for the primary teeth were statistically different and there was an increase in volume loss with the increase of the load applied in the wear tests. Conclusions: Differences were also observed with regard to the surface deformation characteristics. The wear rates of primary tooth enamel vary according to the type of material and the load applied during mastication. PMID:24966777

The prevalence of tongue lesions in Malaysian dental outpatients from the Klang Valley area.

PubMed

Koay, C L; Lim, J A; Siar, C H

2011-03-01

 To determine the prevalence of tongue lesions in Malaysian dental outpatients from the Klang Valley area.  A cross sectional study was conducted on 600 Malaysian outpatients (257 men, 343 women, mean age, 37.7 years) attending the Primary Dental Care Unit at the Faculty of Dentistry, University of Malaya. Demographic and medical data were recorded for all respondents.  One hundred eighty-one patients (30.2%) (81 men, 100 women, mean age 42.0 years) were diagnosed with at least one tongue lesion (n = 207) at the time of examination. Of these, 24 patients (4%) had two or more tongue lesions present synchronously. Seven different lesions were diagnosed: fissured tongue (13.8%), crenated tongue (7.8%), pigmented tongue (6.2%), geographic tongue (2.2%), ankyloglossia (1.7%), hairy tongue (1.0%) and median rhomboid glossitis (0.2%). Their racial prevalences were Malays (n = 65, 10.8%), Indians (n = 62, 10.3%), Chinese (n = 53, 8.8%) and other race (n = 1, 0.2%). A significant relationship was observed between crenated tongue and race; between four types of tongue lesions (fissured tongue, geographic tongue, crenated tongue and pigmented tongue) and age; and between fissured tongue and gender (P < 0.05). Distribution characteristics of tongue lesions in Malaysians are important as local reference data in the daily clinical practice. © 2010 John Wiley & Sons A/S.

Unilateral Trans-cerebellomedullary Fissure Approach for Occipital Artery to Posterior Inferior Cerebellar Artery Bypass during Aneurysmal Surgery.

PubMed

Abe, Hiroshi; Miki, Koichi; Kobayashi, Hiromasa; Ogata, Toshiyasu; Iwaasa, Mitsutoshi; Matsushima, Toshio; Inoue, Tooru

2017-06-15

Occipital artery (OA) to the posterior inferior cerebellar artery (PICA) bypass is indispensable for the management of complex aneurysms of the PICA that cannot be reconstructed with surgical clipping or coil embolization. Although OA-PICA bypass is a comparatively standard procedure, the bypass is difficult to perform in some cases because of the location and situation of the PICA. We describe the usefulness of the unilateral trans-cerebellomedullary fissure (CMF) approach for OA-PICA bypass. Thirty patients with aneurysms in the vertebral artery (VA) or PICA were treated using OA-PICA bypasses between 2010 and 2015. Among them, the unilateral trans-CMF approach was used for OA-PICA anastomosis in 13 patients. The surgical procedures performed on and the medical records of all the patients were retrospectively reviewed. The unilateral trans-CMF approach was performed for two reasons depending on the PICA location or situation: either because the caudal loop could not be used as a recipient artery because of arterial dissection (3 patients) or because the tonsillo-medullary segment that was located in the upper part of the CMF did not have a caudal loop that was large enough (10 patients). The trans-CMF approach provided a good operative field for the OA-PICA bypass and the anastomosis were successfully performed in all patients. When the recipient artery was located in the upper part of the CMF, the unilateral trans-cerebello-medullary fissure approach provided a sufficient operative field for OA-PICA anastomosis.

Unilateral Trans-cerebellomedullary Fissure Approach for Occipital Artery to Posterior Inferior Cerebellar Artery Bypass during Aneurysmal Surgery

PubMed Central

ABE, Hiroshi; MIKI, Koichi; KOBAYASHI, Hiromasa; OGATA, Toshiyasu; IWAASA, Mitsutoshi; MATSUSHIMA, Toshio; INOUE, Tooru

2017-01-01

Occipital artery (OA) to the posterior inferior cerebellar artery (PICA) bypass is indispensable for the management of complex aneurysms of the PICA that cannot be reconstructed with surgical clipping or coil embolization. Although OA-PICA bypass is a comparatively standard procedure, the bypass is difficult to perform in some cases because of the location and situation of the PICA. We describe the usefulness of the unilateral trans-cerebellomedullary fissure (CMF) approach for OA-PICA bypass. Thirty patients with aneurysms in the vertebral artery (VA) or PICA were treated using OA-PICA bypasses between 2010 and 2015. Among them, the unilateral trans-CMF approach was used for OA-PICA anastomosis in 13 patients. The surgical procedures performed on and the medical records of all the patients were retrospectively reviewed. The unilateral trans-CMF approach was performed for two reasons depending on the PICA location or situation: either because the caudal loop could not be used as a recipient artery because of arterial dissection (3 patients) or because the tonsillo-medullary segment that was located in the upper part of the CMF did not have a caudal loop that was large enough (10 patients). The trans-CMF approach provided a good operative field for the OA-PICA bypass and the anastomosis were successfully performed in all patients. When the recipient artery was located in the upper part of the CMF, the unilateral trans-cerebello-medullary fissure approach provided a sufficient operative field for OA-PICA anastomosis. PMID:28484132

Three-junction solar cell

DOEpatents

Ludowise, Michael J.

1986-01-01

A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

Foreign Objects in the Rectum

MedlinePlus

... Resources In This Article Medical Dictionary Also of Interest (Quiz) Anal Fissure (News) Could a Common Blood Thinner Lower Cancer Risk? (News) Study Untangles Disparity in Colon Cancer Survival Rates (News) Poor Prognosis for Diabetic Foot Sores (News) ...

Supramolecular Systems and Chemical Reactions in Single-Molecule Break Junctions.

PubMed

Li, Xiaohui; Hu, Duan; Tan, Zhibing; Bai, Jie; Xiao, Zongyuan; Yang, Yang; Shi, Jia; Hong, Wenjing

2017-04-01

The major challenges of molecular electronics are the understanding and manipulation of the electron transport through the single-molecule junction. With the single-molecule break junction techniques, including scanning tunneling microscope break junction technique and mechanically controllable break junction technique, the charge transport through various single-molecule and supramolecular junctions has been studied during the dynamic fabrication and continuous characterization of molecular junctions. This review starts from the charge transport characterization of supramolecular junctions through a variety of noncovalent interactions, such as hydrogen bond, π-π interaction, and electrostatic force. We further review the recent progress in constructing highly conductive molecular junctions via chemical reactions, the response of molecular junctions to external stimuli, as well as the application of break junction techniques in controlling and monitoring chemical reactions in situ. We suggest that beyond the measurement of single molecular conductance, the single-molecule break junction techniques provide a promising access to study molecular assembly and chemical reactions at the single-molecule scale.

Monolithic multi-color light emission/detection device

DOEpatents

Wanlass, Mark W.

1995-01-01

A single-crystal, monolithic, tandem, multi-color optical transceiver device is described, including (a) an InP substrate having upper and lower surfaces, (b) a first junction on the upper surface of the InP substrate, (c) a second junction on the first junction. The first junction is preferably GaInAsP of defined composition, and the second junction is preferably InP. The two junctions are lattice matched. The second junction has a larger energy band gap than the first junction. Additional junctions having successively larger energy band gaps may be included. The device is capable of simultaneous and distinct multi-color emission and detection over a single optical fiber.

Electronic thermometry in tunable tunnel junction

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

Maksymovych, Petro

A tunable tunnel junction thermometry circuit includes a variable width tunnel junction between a test object and a probe. The junction width is varied and a change in thermovoltage across the junction with respect to the change in distance across the junction is determined. Also, a change in biased current with respect to a change in distance across the junction is determined. A temperature gradient across the junction is determined based on a mathematical relationship between the temperature gradient, the change in thermovoltage with respect to distance and the change in biased current with respect to distance. Thermovoltage may bemore » measured by nullifying a thermoelectric tunneling current with an applied voltage supply level. A piezoelectric actuator may modulate the probe, and thus the junction width, to vary thermovoltage and biased current across the junction. Lock-in amplifiers measure the derivatives of the thermovoltage and biased current modulated by varying junction width.« less

Gap junctions contain different amounts of cholesterol which undergo unique sequestering processes during fiber cell differentiation in the embryonic chicken lens.

PubMed

Biswas, Sondip K; Lo, Woo-Kuen

2007-03-09

To determine the possible changes in the distribution of cholesterol in gap junction plaques during fiber cell differentiation and maturation in the embryonic chicken lens. The possible mechanism by which cholesterol is removed from gap junction plaques is also investigated. Filipin cytochemistry in conjunction with freeze-fracture TEM was used to visualize cholesterol, as represented by filipin-cholesterol complexes (FCCs) in gap junction plaques. Quantitative analysis on the heterogeneous distribution of cholesterol in gap junction plaques was conducted from outer and inner cortical regions. A novel technique combining filipin cytochemistry with freeze-fracture replica immunogold labeling (FRIL) was used to label Cx45.6 and Cx56 antibodies in cholesterol-containing gap junctions. Filipin cytochemistry and freeze-fracture TEM and thin-section TEM were used to examine the appearance and nature of the cholesterol-containing vesicular structures associated with gap junction plaques. Chicken lens fibers contain cholesterol-rich, cholesterol-intermediate and cholesterol-free gap junction populations in both outer and inner cortical regions. Filipin cytochemistry and FRIL studies confirmed that cholesterol-containing junctions were gap junctions. Quantitative analysis showed that approximately 86% of gap junctions in the outer cortical zone were cholesterol-rich gap junctions, whereas approximately 81% of gap junctions in the inner cortical zone were cholesterol-free gap junctions. A number of pleiomorphic cholesterol-rich vesicles of varying sizes were often observed in the gap junction plaques. They appear to be involved in the removal of cholesterol from gap junction plaques through endocytosis. Gap junctions in the young fibers are enriched with cholesterol because they are assembled in the unique cholesterol-rich cell membranes in the lens. A majority of cholesterol-rich gap junctions in the outer young fibers are transformed into cholesterol-free ones in the inner mature fibers during fiber cell maturation. A distinct endocytotic process appears to be involved in removing cholesterol from the cholesterol-containing gap junctions, and it may play a major role in the transformation of cholesterol-rich gap junctions into cholesterol-free ones during fiber cell maturation.

Monolithic multi-color light emission/detection device

DOEpatents

Wanlass, M.W.

1995-02-21

A single-crystal, monolithic, tandem, multi-color optical transceiver device is described, including (a) an InP substrate having upper and lower surfaces, (b) a first junction on the upper surface of the InP substrate, (c) a second junction on the first junction. The first junction is preferably GaInAsP of defined composition, and the second junction is preferably InP. The two junctions are lattice matched. The second junction has a larger energy band gap than the first junction. Additional junctions having successively larger energy band gaps may be included. The device is capable of simultaneous and distinct multi-color emission and detection over a single optical fiber. 5 figs.

Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa

PubMed Central

Borgonie, G.; Linage-Alvarez, B.; Ojo, A. O.; Mundle, S.O.C.; Freese, L B.; Van Rooyen, C.; Kuloyo, O.; Albertyn, J.; Pohl, C.; Cason, E. D.; Vermeulen, J.; Pienaar, C.; Litthauer, D.; Van Niekerk, H.; Van Eeden, J.; Lollar, B. Sherwood.; Onstott, T. C.; Van Heerden, E.

2015-01-01

Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system. PMID:26597082

Discrete domains of gene expression in germinal layers distinguish the development of gyrencephaly

PubMed Central

de Juan Romero, Camino; Bruder, Carl; Tomasello, Ugo; Sanz-Anquela, José Miguel; Borrell, Víctor

2015-01-01

Gyrencephalic species develop folds in the cerebral cortex in a stereotypic manner, but the genetic mechanisms underlying this patterning process are unknown. We present a large-scale transcriptomic analysis of individual germinal layers in the developing cortex of the gyrencephalic ferret, comparing between regions prospective of fold and fissure. We find unique transcriptional signatures in each germinal compartment, where thousands of genes are differentially expressed between regions, including ∼80% of genes mutated in human cortical malformations. These regional differences emerge from the existence of discrete domains of gene expression, which occur at multiple locations across the developing cortex of ferret and human, but not the lissencephalic mouse. Complex expression patterns emerge late during development and map the eventual location of folds or fissures. Protomaps of gene expression within germinal layers may contribute to define cortical folds or functional areas, but our findings demonstrate that they distinguish the development of gyrencephalic cortices. PMID:25916825

Thermal areas on Kilauea and Mauna Loa Volcanoes, Hawaii

USGS Publications Warehouse

Casadevall, Thomas J.; Hazlett, Richard W.

1983-01-01

Active thermal areas are concentrated in three areas on Mauna Loa and three areas on Kilauea. High-temperature fumaroles (115-362°C) on Mauna Loa are restricted to the summit caldera, whereas high-temperature fumaroles on Kilauea are found in the upper East Rift Zone (Mauna Ulu summit fumaroles, 562°C), middle East Rift Zone (1977 eruptive fissure fumaroles), and in the summit caldera. Solfataric activity that has continued for several decades occurs along border faults of Kilauea caldera and at Sulphur Cone on the southwest rift zone of Mauna Loa. Solfataras that are only a few years old occur along recently active eruptive fissures in the summit caldera and along the rift zones of Kilauea. Steam vents and hot-air cracks also occur at the edges of cooling lava ponds, on the summits of lava shields, along faults and graben fractures, and in diffuse patches that may reflect shallow magmatic intrusions.

Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa.

PubMed

Borgonie, G; Linage-Alvarez, B; Ojo, A O; Mundle, S O C; Freese, L B; Van Rooyen, C; Kuloyo, O; Albertyn, J; Pohl, C; Cason, E D; Vermeulen, J; Pienaar, C; Litthauer, D; Van Niekerk, H; Van Eeden, J; Sherwood Lollar, B; Onstott, T C; Van Heerden, E

2015-11-24

Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system.

Methylmercury poisoning in common marmosets--a study of selective vulnerability within the cerebral cortex.

PubMed

Eto, K; Yasutake, A; Kuwana, T; Korogi, Y; Akima, M; Shimozeki, T; Tokunaga, H; Kaneko, Y

2001-01-01

Neuropathological lesions found in chronic human Minamata disease tend to be localized in the calcarine cortex of occipital lobes, the pre- and postcentral lobuli, and the temporal gyri. The mechanism for the selective vulnerability is still not clear, though several hypotheses have been proposed. One hypothesis is vascular and postulates that the lesions are the result of ischemia secondary to compression of sulcal arteries from methylmercury-induced cerebral edema. To test this hypothesis, we studied common marmosets because the cerebrum of marmosets has 2 distinct deep sulci, the calcarine and Sylvian fissures. MRI analysis, mercury assays of tissue specimens, histologic and histochemical studies of the brain are reported and discussed. Brains sacrificed early after exposure to methylmercury showed high contents of methylmercury and edema of the cerebral white matter. These results may explain the selective cortical degeneration along the deep cerebral fissures or sulci.

The first case of Niikawa-Kuroki syndrome in Kazakhstan associated with café au lait spots.

PubMed

Al Mosawi, A J; Fewin, L

2009-10-01

Niikawa-Kuroki syndrome (Kabuki syndrome) is a multiple congenital anomaly syndrome of unknown etiology with a very wide spectrum of abnormalities and severity. The aim of this paper was to report the first case of the syndrome in Kazakhstan associated café au lait. Five year and half old boy from Kazakhstan (Uzbek-of Turk ethnicity) presented with dysmorphic facial features (long palpebral fissures, a broad and depressed nasal tip, large prominent earlobes, small head, epicanthic folds short stature, delayed language development, hypotonia, bilateral developmental dysplasia of the hip (DDH), large ears and triangular chin, café au lait spots. The clinical diagnosis was based on the triad of characteristic facial abnormalities (long palpebral fissures, a broad and depressed nasal tip, large prominent earlobes, small head), growth retardation, (DDH). In this paper the authors report the first case of Kabuki syndrome associated with café au lait spots.

Spatially resolved SO2 flux emissions from Mt Etna.

PubMed

D'Aleo, R; Bitetto, M; Delle Donne, D; Tamburello, G; Battaglia, A; Coltelli, M; Patanè, D; Prestifilippo, M; Sciotto, M; Aiuppa, A

2016-07-28

We report on a systematic record of SO 2 flux emissions from individual vents of Etna volcano (Sicily), which we obtained using a permanent UV camera network. Observations were carried out in summer 2014, a period encompassing two eruptive episodes of the New South East Crater (NSEC) and a fissure-fed eruption in the upper Valle del Bove. We demonstrate that our vent-resolved SO 2 flux time series allow capturing shifts in activity from one vent to another and contribute to our understanding of Etna's shallow plumbing system structure. We find that the fissure eruption contributed ~50,000 t of SO 2 or ~30% of the SO 2 emitted by the volcano during the 5 July to 10 August eruptive interval. Activity from this eruptive vent gradually vanished on 10 August, marking a switch of degassing toward the NSEC. Onset of degassing at the NSEC was a precursory to explosive paroxysmal activity on 11-15 August.

Development of a fused slurry silicide coating for the protection of tantalum alloys

NASA Technical Reports Server (NTRS)

Packer, C. M.; Perkins, R. A.

1974-01-01

Results are reported of a research program to develop a reliable high-performance, fused slurry silicide protective coating for a tantalum-10 tungsten alloy for use at 1427 to 1538 C at 0.1 to 10 torr air pressure under cyclic temperature conditions. A review of silicide coating performance under these conditions indicated that the primary wear-out mode is associated with widening of hairline fissures in the coating. Consideration has been given to modifying the oxidation products that form on the coating surface to provide a seal for these fissures and to minimize their widening. On the basis of an analysis of the phase relationships between silica and various other oxides, a coating having the slurry composition 2.5Mn-33Ti-64.5Si was developed that is effective in the pressure range from 1 to 10 torr.

Gap/silicon Tandem Solar Cell with Extended Temperature Range

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A. (Inventor)

2006-01-01

A two-junction solar cell has a bottom solar cell junction of crystalline silicon, and a top solar cell junction of gallium phosphide. A three (or more) junction solar cell has bottom solar cell junctions of silicon, and a top solar cell junction of gallium phosphide. The resulting solar cells exhibit improved extended temperature operation.

Groundwater drainage from fissures as a source for lahars

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

Johnson, P. J.; Valentine, G. A.; Stauffer, P. H.

One mechanism for generating lahars at volcanoes experiencing unrest is the disruption of internal aquifers. These disruptions can trigger releases of large quantities of groundwater. An example of such aquifer disruption occurred at Nevado del Huila Volcano, Colombia, during February and April 2007 when large fractures formed across the summit area of the volcano and lahars were emitted from them. Previous work interpreted that lahar volumes could not be accounted for by melted glacial snow or precipitation, and by elimination suggested that the primary water source was groundwater. Conceptual models have been developed for perched, confined aquifers that have beenmore » heated and pressurized by magma intrusions, followed by sudden pressure release and water emission during fracture formation. In this paper, we consider an alternative end member wherein water release from large fissures at volcanoes is driven by simple gravity drainage. We apply numerical modeling to quantify water discharge from the porous medium surrounding a fissure with a low-elevation free exit. If a long fracture with high vertical extent (on the order of hundreds of meters) intersects a highly connected saturated porous medium, large volumes (on order 10 3 m 3/m of crack length) of water may be released within tens of minutes. The drainage rates from the model may be adequate to account for the Nevado del Huila events if the medium surrounding the crack contains a large volume of water and has high horizontal permeability. Finally, this simple but poorly understood mechanism can present a hazard on its own or compound other processes releasing water from volcanoes.« less

Microbial Diversity in Endostromatolites (cf. Fissure Calcretes) and in the Surrounding Permafrost Landscape, Haughton Impact Structure Region, Devon Island, Canada

NASA Astrophysics Data System (ADS)

Pellerin, André; Lacelle, Denis; Fortin, Danielle; Clark, Ian D.; Lauriol, Bernard

2009-11-01

In recent years, endostromatolites, which consist of finely laminated calcite columns that grow orthogonally within millimeter- to centimeter-thick fissures in limestone bedrock outcrops, have been discovered in dolomitic outcrops in the Haughton impact structure region, Devon Island, Canada. The growth mechanism of the endostromatolites is believed to be very slow and possibly intertwined with biotic and abiotic processes. Therefore, to discern how endostromatolites form in this polar desert environment, the composition of the microbial community of endostromatolites was determined by means of molecular phylogenetic analysis and compared to the microbial communities found in the surrounding soils. The microbial community present within endostromatolites can be inferred to be (given the predominant metabolic traits of related organisms) mostly aerobic and chemoheterotrophic, and belongs in large part to the phylum Actinobacteria and the subphylum Alphaproteobacteria. The identification of these bacteria suggests that the conditions within the fissure were mostly oxidizing during the growth of endostromatolite. The DNA sequences also indicate that a number of bacteria that closely resemble Rubrobacter radiotolerans are abundant in the endostromatolites as well as other Actinobacteria and Alphaproteobacteria. Some of these taxa have been associated with calcite precipitation, which suggests that the endostromatolites might in fact be microbially mediated. Bacterial communities from nearby permanently frozen soils were more diverse and harbored all the phyla found in the endostromatolites with additional taxa. This study on the microbial communities preserved in potentially microbially mediated secondary minerals in the Arctic could help in the search for evidence of life-forms near the edge of habitability on other planetary bodies.

Remineralization Capacity of Three Fissure Sealants with and without Gaseous Ozone on Non-Cavitated Incipient Pit and Fissure Caries.

PubMed

Unal, M; Oztas, N

2015-01-01

The purpose of this study was to investigate the remineralization activation of the application of three fissure sealants (FSs), alone or with gaseous ozone (GO), on non-cavitated initial caries and evaluate the clinical success of FS. Sixty children who had DIAGNOdent scores between 10-30 on bilateral symmetric mandibular first permanent molars were included in study. In a split-mouth design, teeth were assigned to experimental (with GO) and control (without GO) groups. GO was applied to teeth on one side and then the same brand of randomly selected FSs was applied to the teeth on both sides. Children were divided into 3 groups based on type of FS (Group 1: Aegis {Bosworth Co, North Hamlin Avenue Skokie, Illinois, USA}, Group 2: Fuji Triage {GC, Tokyo, Japan}, Group 3: Helioseal {Ivoclar Vivadent, Liechtenstein, Germany}). All FSs were then examined for retention rates at 1, 3, 6, 9, and 12 months; at the end of 12 months, all FSs were removed with an air-abrasion device and DIAGNOdent scores noted to compare with the initial values. The application of GO with either Fuji Triage or Aegis FS was effective on remineralization (p<0.05); however, the application of Helioseal FSs was not effective (p>0.05). The 1(st) and 12(th) months' full retention rates of Fuji Triage FSs was a significant difference (p<0.05) from other FSs (Aegis and Helioseal) (p>0.05). GO+Aegis FS showed the highest remineralization; and, at the end of 12 months, its clinical success was higher than other FSs.

Starch granule evidence for the earliest potato use in North America

PubMed Central

Louderback, Lisbeth A.; Pavlik, Bruce M.

2017-01-01

The prehistory of wild potato use, leading to its domestication and diversification, has been well-documented in, and confined to, South America. At least 20 tuber-bearing, wild species of Solanum are known from North and Central America, yet their importance in ancient diets has never been assessed from the archaeological record. Here, we report the earliest evidence of wild potato use in North America at 10,900–10,100 calendar years (cal) B.P. in the form of well-preserved starch granules extracted from ground stone tools at North Creek Shelter, southern Utah. These granules have been identified as those of Solanum jamesii Torr. (Four Corners potato), a tuber-bearing species native to the American Southwest. Identification was based on applying five strictly defined diagnostic characteristics (eccentric hilum, longitudinal fissure, lack of fissure branching, fissure ratio, and maximum granule size) to each of 323 archaeological granules. Of those, nine were definitively assigned to S. jamesii based on possession of all characteristics, and another 61 were either likely or possibly S. jamesii depending on the number of characteristics they possessed. The oldest granules were found in substratum 4k (10,900–10,100 cal B.P.). Younger deposits, dating to ∼6,900 cal B.P., also contained tools with S. jamesii granules, indicating at least 4,000 y of intermittent use. Ethnographic and historical accounts extend the period of use to more than 10,000 y. The question then arises as to whether some S. jamesii populations could have undergone transport, cultivation, and eventual domestication over such a long period of time. PMID:28673982

Low and high dietary folic acid levels perturb postnatal cerebellar morphology in growing rats.

PubMed

Partearroyo, Teresa; Pérez-Miguelsanz, Juliana; Peña-Melián, Ángel; Maestro-de-Las-Casas, Carmen; Úbeda, Natalia; Varela-Moreiras, Gregorio

2016-06-01

The brain is particularly sensitive to folate metabolic disturbances, because methyl groups are critical for brain functions. This study aimed to investigate the effects of different dietary levels of folic acid (FA) on postnatal cerebellar morphology, including the architecture and organisation of the various layers. A total of forty male OFA rats (a Sprague-Dawley strain), 5 weeks old, were classified into the following four dietary groups: FA deficient (0 mg/kg FA); FA supplemented (8 mg/kg FA); FA supra-supplemented (40 mg/kg FA); and control (2 mg/kg FA) (all n 10 per group). Rats were fed ad libitum for 30 d. The cerebellum was quickly removed and processed for histological and immunohistochemical analysis. Slides were immunostained for glial fibrillary acidic protein (to label Bergmann glia), calbindin (to label Purkinje cells) and NeuN (to label post-mitotic neurons). Microscopic analysis revealed two types of defect: partial disappearance of fissures and/or neuronal ectopia, primarily in supra-supplemented animals (incidence of 80 %, P≤0·01), but also in deficient and supplemented groups (incidence of 40 %, P≤0·05), compared with control animals. The primary fissure was predominantly affected, sometimes accompanied by defects in the secondary fissure. Our findings show that growing rats fed an FA-modified diet, including both deficient and supplemented diets, have an increased risk of disturbances in cerebellar corticogenesis. Defects caused by these diets may have functional consequences in later life. The present study is the first to demonstrate that cerebellar morphological defects can arise from deficient, as well as high, FA levels in the diet.

Groundwater drainage from fissures as a source for lahars

NASA Astrophysics Data System (ADS)

Johnson, P. J.; Valentine, G. A.; Stauffer, P. H.; Lowry, C. S.; Sonder, I.; Pulgarín, B. A.; Santacoloma, C. C.; Agudelo, A.

2018-04-01

One mechanism for generating lahars at volcanoes experiencing unrest is the disruption of internal aquifers. These disruptions can trigger releases of large quantities of groundwater. An example of such aquifer disruption occurred at Nevado del Huila Volcano, Colombia, during February and April 2007 when large fractures formed across the summit area of the volcano and lahars were emitted from them. Previous work interpreted that lahar volumes could not be accounted for by melted glacial snow or precipitation, and by elimination suggested that the primary water source was groundwater. Conceptual models have been developed for perched, confined aquifers that have been heated and pressurized by magma intrusions, followed by sudden pressure release and water emission during fracture formation. We consider an alternative end member wherein water release from large fissures at volcanoes is driven by simple gravity drainage. We apply numerical modeling to quantify water discharge from the porous medium surrounding a fissure with a low-elevation free exit. If a long fracture with high vertical extent (on the order of hundreds of meters) intersects a highly connected saturated porous medium, large volumes (on order 103 m3/m of crack length) of water may be released within tens of minutes. The drainage rates from the model may be adequate to account for the Nevado del Huila events if the medium surrounding the crack contains a large volume of water and has high horizontal permeability. This simple but poorly understood mechanism can present a hazard on its own or compound other processes releasing water from volcanoes.

The hyaloid vasculature facilitates basement membrane breakdown during choroid fissure closure in the zebrafish eye.

PubMed

James, Andrea; Lee, Chanjae; Williams, Andre M; Angileri, Krista; Lathrop, Kira L; Gross, Jeffrey M

2016-11-15

A critical aspect of vertebrate eye development is closure of the choroid fissure (CF). Defects in CF closure result in colobomas, which are a significant cause of childhood blindness worldwide. Despite the growing number of mutated loci associated with colobomas, we have a limited understanding of the cell biological underpinnings of CF closure. Here, we utilize the zebrafish embryo to identify key phases of CF closure and regulators of the process. Utilizing Laminin-111 as a marker for the basement membrane (BM) lining the CF, we determine the spatial and temporal patterns of BM breakdown in the CF, a prerequisite for CF closure. Similarly, utilizing a combination of in vivo time-lapse imaging, β-catenin immunohistochemistry and F-actin staining, we determine that tissue fusion, which serves to close the fissure, follows BM breakdown closely. Periocular mesenchyme (POM)-derived endothelial cells, which migrate through the CF to give rise to the hyaloid vasculature, possess distinct actin foci that correlate with regions of BM breakdown. Disruption of talin1, which encodes a regulator of the actin cytoskeleton, results in colobomas and these correlate with structural defects in the hyaloid vasculature and defects in BM breakdown. cloche mutants, which entirely lack a hyaloid vasculature, also possess defects in BM breakdown in the CF. Taken together, these data support a model in which the hyaloid vasculature and/or the POM-derived endothelial cells that give rise to the hyaloid vasculature contribute to BM breakdown during CF closure. Copyright © 2016 Elsevier Inc. All rights reserved.

Groundwater drainage from fissures as a source for lahars

DOE PAGES

Johnson, P. J.; Valentine, G. A.; Stauffer, P. H.; ...

2018-03-22

One mechanism for generating lahars at volcanoes experiencing unrest is the disruption of internal aquifers. These disruptions can trigger releases of large quantities of groundwater. An example of such aquifer disruption occurred at Nevado del Huila Volcano, Colombia, during February and April 2007 when large fractures formed across the summit area of the volcano and lahars were emitted from them. Previous work interpreted that lahar volumes could not be accounted for by melted glacial snow or precipitation, and by elimination suggested that the primary water source was groundwater. Conceptual models have been developed for perched, confined aquifers that have beenmore » heated and pressurized by magma intrusions, followed by sudden pressure release and water emission during fracture formation. In this paper, we consider an alternative end member wherein water release from large fissures at volcanoes is driven by simple gravity drainage. We apply numerical modeling to quantify water discharge from the porous medium surrounding a fissure with a low-elevation free exit. If a long fracture with high vertical extent (on the order of hundreds of meters) intersects a highly connected saturated porous medium, large volumes (on order 10 3 m 3/m of crack length) of water may be released within tens of minutes. The drainage rates from the model may be adequate to account for the Nevado del Huila events if the medium surrounding the crack contains a large volume of water and has high horizontal permeability. Finally, this simple but poorly understood mechanism can present a hazard on its own or compound other processes releasing water from volcanoes.« less

Fissure sealant materials: Wear resistance of flowable composite resins.

PubMed

Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

2016-01-01

Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

Tracking the hidden growth of a lava flow field: the 2014-15 eruption of Fogo volcano (Cape Verde)

NASA Astrophysics Data System (ADS)

Silva, Sonia; Calvari, Sonia; Hernandez, Pedro; Perez, Nemesio; Ganci, Gaetana; Alfama, Vera; Barrancos, José; Cabral, Jeremias; Cardoso, Nadir; Dionis, Samara; Fernandes, Paulo; Melian, Gladys; Pereira, José; Semedo, Hélio; Padilla, German; Rodriguez, Fatima

2017-04-01

Fogo volcano erupted in 2014-15 producing an extensive lava flow field in the summit caldera that destroyed two villages, Portela and Bangaeira. The eruption started with powerful explosive activity, lava fountaining, and a substantial ash column accompanying the opening of an eruptive fissure. Lava flows spreading from the base of the eruptive fissure produced three arterial lava flows, spreading S (Flow 1), N-NW (Flow 2) and W (Flow 3). By a week after the start of the eruption, a master lava tube had already developed within the eruptive fissure and along Flow 2. When Flow 2 front stopped against the N caldera cliff, the whole flow field behind it inflated, and eventually its partial drainage produced a short tube that fed Flow 3, but no lava tube formed within Flow 1. Here we analyze the emplacement processes on the basis of observations carried out directly on the lava flow field and through satellite image, in order to unravel the key factors leading to the development of lava tubes. These tubes were responsible for the rapid expansion of lava for the 7.9 km length of the flow field, as well as the destruction of the Portela and Bangaeira villages. Comparing time-averaged effusion rates (TADR) obtained from satellite and Supply Rate (SR) derived from SO2 flux data, we estimate the amount and timing of the lava flow field endogenous growth, with the aim of developing a tool that could be used for risk mitigation at this and other volcanoes.

Fissure sealant materials: Wear resistance of flowable composite resins

PubMed Central

Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

2016-01-01

Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics. PMID:27651887

Bladed Terrain on Pluto: Possible Origins and Evolutions

NASA Technical Reports Server (NTRS)

Moore, Jeffrey M.; Howard, Alan D.; Umurhan, Orkan M.; White, Oliver L.; Schenk, Paul; Beyer, Ross A.; McKinnon, William B.; Spencer, John R.; Singer, Kelsi N.; Grundy, William N.;

Bladed Terrain on Pluto: Possible Origins and Evolutions

NASA Astrophysics Data System (ADS)

Moore, J. M.; Howard, A. D.; Umurhan, O. M.; White, O. L.; Schenk, P.; Beyer, R. A.; McKinnon, W. B.; Spencer, J. R.; Singer, K. N.; Grundy, W. M.; Nimmo, F.; Young, L. A.; Stern, A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.; Collins, G. C.

2016-12-01

Pluto's Bladed Terrain (centered roughly 20°N, 225°E) covers the flanks and crests of the informally named Tartarus Dorsa with numerous roughly aligned blade-like ridges oriented North-South; it may also stretch considerably farther east onto the non-close approach hemisphere but that inference is tentative. Individual ridges are typically several hundred meters high, and are spaced 5 to 10 km crest to crest, separated by V-shaped valleys. Many ridges merge at acute angles to form Y-shape junctions in plan view. The principle composition of the blades themselves we suspect is methane or a methane-rich mixture. (Methane is spectroscopically strongly observed on the optical surfaces of blades.) Nitrogen ice is very probably too soft to support their topography. Cemented mixtures of volatile and non-volatile ices may also provide a degradable but relief supporting "bedrock" for the blades, perhaps analogous to Callisto. Currently we are considering several hypotheses for the origins of the deposit from which Bladed Terrain has evolved, including aeolian disposition, atmospheric condensation, updoming and exhumation, volcanic intrusions or extrusions, crystal growth, among others. We are reviewing several processes as candidate creators or sculptors of the blades. Perhaps they are primary depositional patterns such as dunes, or differential condensation patterns (like on Callisto), or fissure extrusions. Or alternatively perhaps they are the consequence of differential erosion (such as sublimation erosion widening and deepening along cracks), variations in substrate properties, mass wasting into the subsurface, or sculpted by a combination of directional winds and solar isolation orientation. We will consider the roles of the long-term increasing solar flux and short periods of warm thick atmospheres. Hypotheses will be ordered based on observational constrains and modeling to be presented at the conference.

Zooming in on heat at Baghdad Sulcus

NASA Image and Video Library

2010-02-23

This map shows a dramatically improved view of heat radiation from a warm fissure near the south pole of Saturn icy moon Enceladus. It was obtained by NASA Cassini spacecraft during its Nov. 21, 2009, flyby of that moon.

Lava Flow at Kilauea, Hawaii

NASA Image and Video Library

2007-08-31

On July 21, 2007, the world most active volcano, Kilauea on Hawaii Big Island, produced a fissure eruption from the Puu Oo vent, which fed an open lava channel and lava flows toward the east. This image is from NASA Terra satellite.

Gap and tight junctions in the formation of feather branches: A descriptive ultrastructural study.

PubMed

Alibardi, Lorenzo

2010-08-20

The present study has focused on the distribution and ultrastructure of gap and tight junctions responsible for the formation of the barb/barbule branching in developing feathers using immunocytochemical detection. Apart from desmosomes, both tight and gap junctions are present between differentiating barb/barbule cells and during keratinization. While gap junctions are rare along the perimeter of these cells, tight junctions tend to remain localized in nodes joining barbule cells and between barb cells of the ramus. Occludin and connexin-26 but not connexin-43 have been detected between barb medullary, barb cortical and barbule cells during formation of barbs. Gap junctions are present in supportive cells located in the vicinity of barbule cells and destined to degenerate, but no close junctions are present between supportive and barb/barbule cells. Close junctions mature into penta-laminar junctions that are present between mature barb/barbule cells. Immunolabeling for occludin and Cx26 is rare along these cornified junctions. The junctions allow barb/barbule cells to remain connected until feather-keratin form the mature corneous syncytium that constitutes the barbs. A discussion of the role of gap and tight junctions during feather morphogenesis is presented. 2010 Elsevier GmbH. All rights reserved.

An EMMPRIN-γ-catenin-Nm23 complex drives ATP production and actomyosin contractility at endothelial junctions.

PubMed

Moreno, Vanessa; Gonzalo, Pilar; Gómez-Escudero, Jesús; Pollán, Ángela; Acín-Pérez, Rebeca; Breckenridge, Mark; Yáñez-Mó, María; Barreiro, Olga; Orsenigo, Fabrizio; Kadomatsu, Kenji; Chen, Christopher S; Enríquez, José A; Dejana, Elisabetta; Sánchez-Madrid, Francisco; Arroyo, Alicia G

2014-09-01

Cell-cell adhesions are important sites through which cells experience and resist forces. In endothelial cells, these forces regulate junction dynamics and determine endothelial barrier strength. We identify the Ig superfamily member EMMPRIN (also known as basigin) as a coordinator of forces at endothelial junctions. EMMPRIN localization at junctions correlates with endothelial junction strength in different mouse vascular beds. Accordingly, EMMPRIN-deficient mice show altered junctions and increased junction permeability. Lack of EMMPRIN alters the localization and function of VE-cadherin (also known as cadherin-5) by decreasing both actomyosin contractility and tugging forces at endothelial cell junctions. EMMPRIN ensures proper actomyosin-driven maturation of competent endothelial junctions by forming a molecular complex with γ-catenin (also known as junction plakoglobin) and Nm23 (also known as NME1), a nucleoside diphosphate kinase, thereby locally providing ATP to fuel the actomyosin machinery. These results provide a novel mechanism for the regulation of actomyosin contractility at endothelial junctions and might have broader implications in biological contexts such as angiogenesis, collective migration and tissue morphogenesis by coupling compartmentalized energy production to junction assembly. © 2014. Published by The Company of Biologists Ltd.

An EMMPRIN–γ-catenin–Nm23 complex drives ATP production and actomyosin contractility at endothelial junctions

PubMed Central

Moreno, Vanessa; Gonzalo, Pilar; Gómez-Escudero, Jesús; Pollán, Ángela; Acín-Pérez, Rebeca; Breckenridge, Mark; Yáñez-Mó, María; Barreiro, Olga; Orsenigo, Fabrizio; Kadomatsu, Kenji; Chen, Christopher S.; Enríquez, José A.; Dejana, Elisabetta; Sánchez-Madrid, Francisco; Arroyo, Alicia G.

2014-01-01

ABSTRACT Cell–cell adhesions are important sites through which cells experience and resist forces. In endothelial cells, these forces regulate junction dynamics and determine endothelial barrier strength. We identify the Ig superfamily member EMMPRIN (also known as basigin) as a coordinator of forces at endothelial junctions. EMMPRIN localization at junctions correlates with endothelial junction strength in different mouse vascular beds. Accordingly, EMMPRIN-deficient mice show altered junctions and increased junction permeability. Lack of EMMPRIN alters the localization and function of VE-cadherin (also known as cadherin-5) by decreasing both actomyosin contractility and tugging forces at endothelial cell junctions. EMMPRIN ensures proper actomyosin-driven maturation of competent endothelial junctions by forming a molecular complex with γ-catenin (also known as junction plakoglobin) and Nm23 (also known as NME1), a nucleoside diphosphate kinase, thereby locally providing ATP to fuel the actomyosin machinery. These results provide a novel mechanism for the regulation of actomyosin contractility at endothelial junctions and might have broader implications in biological contexts such as angiogenesis, collective migration and tissue morphogenesis by coupling compartmentalized energy production to junction assembly. PMID:24994937

Strain Partitioning and Accumulation across Overlapping Spreading Centers: Geodetic GPS Measurements in South Iceland

NASA Astrophysics Data System (ADS)

La Femina, P. C.; Dixon, T. H.; Malservisi, R.; Árnadóttir, T.; Sigmundsson, F.; Sturkell, E.

2004-12-01

Overlapping spreading centers (OSCs) and propagating ridges are important classes of mid-ocean ridges. Kinematic models of OSCs predict along strike variability in spreading rate associated with the propagation of one center and deactivation of the other. Iceland offers a unique opportunity to investigate strain accumulation and partitioning across slow, overlapping spreading centers, and the influence of a ridge centered hotspot on ridge kinematics and morphology. We present results of detailed GPS observations across the Eastern and Western Volcanic Zones, south Iceland, spanning a seven to nine year inter-rifting period, and compare our observations with two-dimensional elastic half-space models that simulate the long-term spreading process. We then compare the elastic half-space models with simple viscoelastic coupling models. We model three velocity profiles across the EVZ-WVZ system, solving for the spreading rate, locking depth and horizontal location of each spreading center. Our spreading rate estimates indicate along strike variations as expected in an OSC system and total spreading rates consistent with geodetic and geologic plate motion models. Spreading rates in the WVZ increase from northeast (3 ±1 mm/yr) to southwest (7 ±1 mm/yr). Spreading rates in the southwest propagating EVZ decrease from northeast (17 ±1 mm/yr) to southwest (12 ±1 mm/yr). These results are consistent with a model whereby the WVZ is deactivating in the direction of EVZ propagation. The morphology of the two spreading centers reflects the spreading rate differences and their location relative to the Iceland hotspot. The predicted locations of the spreading axis for each zone are consistent with mapped Holocene fissure swarms. The neovolcanic zone of the slower WVZ consists of a narrow (10-20 km wide) axial graben and has had few Holocene eruptions. The faster EVZ consists of two parallel neovolcanic zones separated by a 20 km gap of inactivity, little normal faulting, higher topography and five historical fissure eruptions, reflecting its proximity to the hotspot. The maximum velocity gradient in the EVZ is located on the Veidivotn fissure swarm, which had a small volume eruption in 1864. The last major fissure eruption in the EVZ was the 1783 Lakagigar, located 20 km to the east. This pattern of current and past strain accumulation and release suggests intra-ridge jumping of activity and crustal accretion across a 60 km wide area.

Near-Vent, Fissure-Fed Lava Channel Network Morphologies in the Kīlauea December 1974 Flow: Implications for Differentiating Lava Construction From Fluvial Erosion on Planets

NASA Astrophysics Data System (ADS)

Bleacher, J. E.

2015-12-01

Streamlined islands are often assumed to be the product of erosion by water and are cited as evidence of aqueous flows on Mars. However, lava can build streamlined islands in a manner that is more easily explained by flow thickening followed by partial drainage of preferred lava pathways. Kīlauea's December 1974 (D1974) flow was emplaced as a broad sheet-like flow from a series of en echelon fissures across an older hummocky pāhoehoe tumulus field. The lavas surrounded the tumuli and coalesced to fill a topographic low near the basal scarp of the Koae Fault System. As these obstacles were inundated by the D1974 flow, the lava preferentially cooled around the tumuli to form a higher viscosity zone beneath a smooth crust. Stagnation of these thinner, cooler, and more viscous zones focused the flow into a series of preferred lava pathways located between the stagnant islands. Changes in the local discharge rate disrupted the crust of the flow above the lower viscosity pathways. Older tumuli adjacent to the D1974 flow display the same relief as the flow's islands and uncovered portions of this older flow are exposed at the tops of many islands, supporting an interpretation that islands were anchored by high-standing pre-flow tumuli. As the local lava supply waned, partial drainage of the preferred pathways occurred between the higher-standing surfaces anchored to the older tumuli. The resulting morphology consists of a relatively smooth flow field with thin margins that is dissected by depressed pathways or channels. This morphology resembles an erosional surface incised into a smooth plain, but actually represents an initial constructional process followed by partial drainage within a viscous lava flow. Many other Hawaiian rift zone, fissure-fed flow fields display comparable morphologies in the near vent facies, including islands, terraces, thin flow margins and a lack of well defined topographic levees along channels. Thus, branching channel networks and streamlined islands within fissure-fed flow fields on Mars could have resulted from a combination of initial flow thickening followed by partial drainage of preferred lava pathways, and therefore do not necessarily imply substrate erosion or modification by fluvial processes.

Abundance and ultrastructural diversity of neuronal gap junctions in the OFF and ON sublaminae of the inner plexiform layer of rat and mouse retina.

PubMed

Kamasawa, N; Furman, C S; Davidson, K G V; Sampson, J A; Magnie, A R; Gebhardt, B R; Kamasawa, M; Yasumura, T; Zumbrunnen, J R; Pickard, G E; Nagy, J I; Rash, J E

2006-11-03

Neuronal gap junctions are abundant in both outer and inner plexiform layers of the mammalian retina. In the inner plexiform layer (IPL), ultrastructurally-identified gap junctions were reported primarily in the functionally-defined and anatomically-distinct ON sublamina, with few reported in the OFF sublamina. We used freeze-fracture replica immunogold labeling and confocal microscopy to quantitatively analyze the morphologies and distributions of neuronal gap junctions in the IPL of adult rat and mouse retina. Under "baseline" conditions (photopic illumination/general anesthesia), 649 neuronal gap junctions immunogold-labeled for connexin36 were identified in rat IPL, of which 375 were photomapped to OFF vs. ON sublaminae. In contrast to previous reports, the volume-density of gap junctions was equally abundant in both sublaminae. Five distinctive morphologies of gap junctions were identified: conventional crystalline and non-crystalline "plaques" (71% and 3%), plus unusual "string" (14%), "ribbon" (7%) and "reticular" (2%) forms. Plaque and reticular gap junctions were distributed throughout the IPL. However, string and ribbon gap junctions were restricted to the OFF sublamina, where they represented 48% of gap junctions in that layer. In string and ribbon junctions, curvilinear strands of connexons were dispersed over 5 to 20 times the area of conventional plaques having equal numbers of connexons. To define morphologies of gap junctions under different light-adaptation conditions, we examined an additional 1150 gap junctions from rats and mice prepared after 30 min of photopic, mesopic and scotopic illumination, with and without general anesthesia. Under these conditions, string and ribbon gap junctions remained abundant in the OFF sublamina and absent in the ON sublamina. Abundant gap junctions in the OFF sublamina of these two rodents with rod-dominant retinas revealed previously-undescribed but extensive pathways for inter-neuronal communication; and the wide dispersion of connexons in string and ribbon gap junctions suggests unique structural features of gap junctional coupling in the OFF vs. ON sublamina.

1.00 MeV proton radiation resistance studies of single-junction and single gap dual-junction amorphous-silicon alloy solar cells

NASA Technical Reports Server (NTRS)

Abdulaziz, Salman; Payson, J. S.; Li, Yang; Woodyard, James R.

1990-01-01

A comparative study of the radiation resistance of a-Si:H and a-SiGe:H single-junction and a-Si:H dual-junction solar cells was conducted. The cells were irradiated with 1.00-MeV protons with fluences of 1.0 x 10 to the 14th, 5.0 x 10 to the 14th and 1.0 x 10 to the 15th/sq cm and characterized using I-V and quantum efficiency measurements. The radiation resistance of single-junction cells cannot be used to explain the behavior of dual-junction cells at a fluence of 1.0 x 10 to the 15th/sq cm. The a-Si H single-junction cells degraded the least of the three cells; a-SiGe:H single-junction cells showed the largest reduction in short-circuit current, while a-Si:H dual-junction cells exhibited the largest degradation in the open-circuit voltage. The quantum efficiency of the cells degraded more in the red part of the spectrum; the bottom junction degrades first in dual-junction cells.

Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers

DOEpatents

Chang, Y. Austin; Yang, Jianhua Joshua

2008-11-11

This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

Possible involvement of gap junctions in the barrier function of tight junctions of brain and lung endothelial cells.

PubMed

Nagasawa, Kunihiko; Chiba, Hideki; Fujita, Hiroki; Kojima, Takashi; Saito, Tsuyoshi; Endo, Toshiaki; Sawada, Norimasa

2006-07-01

Gap-junction plaques are often observed with tight-junction strands of vascular endothelial cells but the molecular interaction and functional relationships between these two junctions remain obscure. We herein show that gap-junction proteins connexin40 (Cx40) and Cx43 are colocalized and coprecipitated with tight-junction molecules occludin, claudin-5, and ZO-1 in porcine blood-brain barrier (BBB) endothelial cells. Gap junction blockers 18beta-glycyrrhetinic acid (18beta-GA) and oleamide (OA) did not influence expression of Cx40, Cx43, occludin, claudin-5, junctional adhesion molecule (JAM)-A, JAM-B, JAM-C, or ZO-1, or their subcellular localization in the porcine BBB endothelial cells. In contrast, these gap-junction blocking agents inhibited the barrier function of tight junctions in cells, determined by measurement of transendothelial electrical resistance and paracellular flux of mannitol and inulin. 18beta-GA also significantly reduced the barrier property in rat lung endothelial (RLE) cells expressing doxycycline-induced claudin-1, but did not change the interaction between Cx43 and either claudin-1 or ZO-1, nor their expression levels or subcellular distribution. These findings suggest that Cx40- and/or Cx43-based gap junctions might be required to maintain the endothelial barrier function without altering the expression and localization of the tight-junction components analyzed. Copyright 2006 Wiley-Liss, Inc.

Research and develop locking design for NJDOT junction boxes : final report, April 2009.

DOT National Transportation Integrated Search

2009-04-01

The report outlines the guidelines for securing electrical junction box covers to the junction box to prevent vandalism. The report provides details drawings that show various methods for securing the junction box cover to the junction box.

Four-junction superconducting circuit

PubMed Central

Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

2016-01-01

We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit. PMID:27356619

Intercellular junctions between palisade nerve endings and outer root sheath cells of rat vellus hairs.

PubMed

Kaidoh, T; Inoué, T

2000-05-15

Hair follicles have a longitudinal set of sensory nerve endings called palisade nerve endings (PN). We examined the junctional structures between the PN and outer root sheath (ORS) cells of hair follicles in the rat external ear. Transmission electron microscopy of serial thin sections showed that the processes of the ORS cells penetrated the basal lamina of the hair follicle, forming intercellular junctions with the PN (PN-ORS junctions). Two types of junctions were found: junctions between nerve endings and ORS cells (N-ORS junctions) and those between Schwann cell processes and ORS cells (S-ORS junctions). The N-ORS junctions had two subtypes: 1) a short process or small eminence of the ORS cell was attached to the nerve ending (type I); or 2) a process of the ORS cell was invaginated into the nerve ending (type II). The S-ORS junctions also had two subtypes: 1) a short process or small eminence of the ORS cell was abutted on the Schwann cell process (type I); or 2) a process of the ORS cell was invaginated into the Schwann cell process (type II). Vesicles, coated pits, coated vesicles, and endosomes were sometimes seen in nerve endings, Schwann cells, and ORS cells near the junctions. Computer-aided reconstruction of the serial thin sections displayed the three-dimensional structure of these junctions. These results suggested that the PN-ORS junctions provided direct relationships between the PN and ORS in at least four different patterns. The discovery of these junctions shows the PN-ORS relationship to be closer than previously realized. We speculate that these junctions may have roles in attachment of the PN to the ORS, contributing to increases in the sensitivity of the PN, and in chemical signaling between the PN and ORS.

Superstrate sub-cell voltage-matched multijunction solar cells

DOEpatents

Mascarenhas, Angelo; Alberi, Kirstin

2016-03-15

Voltage-matched thin film multijunction solar cell and methods of producing cells having upper CdTe pn junction layers formed on a transparent substrate which in the completed device is operatively positioned in a superstate configuration. The solar cell also includes a lower pn junction formed independently of the CdTe pn junction and an insulating layer between CdTe and lower pn junctions. The voltage-matched thin film multijunction solar cells further include a parallel connection between the CdTe pn junction and lower pn junctions to form a two-terminal photonic device. Methods of fabricating devices from independently produced upper CdTe junction layers and lower junction layers are also disclosed.

Effect of solar-cell junction geometry on open-circuit voltage

NASA Technical Reports Server (NTRS)

Weizer, V. G.; Godlewski, M. P.

1985-01-01

Simple analytical models have been found that adequately describe the voltage behavior of both the stripe junction and dot junction grating cells as a function of junction area. While the voltage in the former case is found to be insensitive to junction area reduction, significant voltage increases are shown to be possible for the dot junction cell. With regard to cells in which the junction area has been increased in a quest for better performance, it was found that (1) texturation does not affect the average saturation current density J0, indicating that the texturation process is equivalent to a simple extension of junction area by a factor of square root of 3 and (2) the vertical junction cell geometry produces a sizable decrease in J0 that, unfortunately, is more than offset by the effects of attendant areal increases.

Anisotropic-Scale Junction Detection and Matching for Indoor Images.

PubMed

Xue, Nan; Xia, Gui-Song; Bai, Xiang; Zhang, Liangpei; Shen, Weiming

Junctions play an important role in characterizing local geometrical structures of images, and the detection of which is a longstanding but challenging task. Existing junction detectors usually focus on identifying the location and orientations of junction branches while ignoring their scales, which, however, contain rich geometries of images. This paper presents a novel approach for junction detection and characterization, which especially exploits the locally anisotropic geometries of a junction and estimates its scales by relying on an a-contrario model. The output junctions are with anisotropic scales, saying that a scale parameter is associated with each branch of a junction and are thus named as anisotropic-scale junctions (ASJs). We then apply the new detected ASJs for matching indoor images, where there are dramatic changes of viewpoints and the detected local visual features, e.g., key-points, are usually insufficient and lack distinctive ability. We propose to use the anisotropic geometries of our junctions to improve the matching precision of indoor images. The matching results on sets of indoor images demonstrate that our approach achieves the state-of-the-art performance on indoor image matching.Junctions play an important role in characterizing local geometrical structures of images, and the detection of which is a longstanding but challenging task. Existing junction detectors usually focus on identifying the location and orientations of junction branches while ignoring their scales, which, however, contain rich geometries of images. This paper presents a novel approach for junction detection and characterization, which especially exploits the locally anisotropic geometries of a junction and estimates its scales by relying on an a-contrario model. The output junctions are with anisotropic scales, saying that a scale parameter is associated with each branch of a junction and are thus named as anisotropic-scale junctions (ASJs). We then apply the new detected ASJs for matching indoor images, where there are dramatic changes of viewpoints and the detected local visual features, e.g., key-points, are usually insufficient and lack distinctive ability. We propose to use the anisotropic geometries of our junctions to improve the matching precision of indoor images. The matching results on sets of indoor images demonstrate that our approach achieves the state-of-the-art performance on indoor image matching.

High-efficiency solar cell and method for fabrication

DOEpatents

Hou, Hong Q.; Reinhardt, Kitt C.

1999-01-01

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

High-efficiency solar cell and method for fabrication

DOEpatents

Hou, H.Q.; Reinhardt, K.C.

1999-08-31

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD). 4 figs.

[Influence of Cx26/Cx32 gap junction channel on antineoplastic effect of etoposide in Hela cells].

PubMed

Tong, Xu-Hui; Dong, Shu-Ying; Jiang, Guo-Jun; Fan, Gao-Fu

2012-03-01

To observe the influence of Cx26/Cx32 gap junction channel on the antineoplastic effect of etoposide in Hela cervical cancer cells. Fluorescence trace was used to assay the gap junction intercellular communication mediated by Cx26/Cx32 in Hela cells and its functional modulation by the pharmacological agents (oleamide, retinoid acid). A standard colony-forming assay was applied to determine the cell growth-inhibiting effect of etoposide in Hela cells with functional modulation of the gap junction. Hoechst 33258 staining was used to assess the changes in etoposide-induced apoptosis of Hela cells with altered gap junction functions. Oleamide markedly decreased while retinoid acid obviously increased the gap junction function in Hela cells. Standard colony-forming assay showed that etoposide produced a lowered antiproliferative effect in Hela cells with reduced gap junction and an increased antiproliferative effect in cells with enhanced gap junction function. In cells with a reduced gap junction function, etoposide induced a lowered apoptosis rate, which increased obviously in cells with an enhanced gap junction function. The antineoplastic effect of etoposide is reduced in Hela cells with a decreased gap junction intercellular communication mediated by Cx26/Cx32 and is enhanced in cells with an increased gap junction intercellular communication.

Effects of 18beta-glycyrrhetinic acid on the junctional complex and steroidogenesis in rat adrenocortical cells.

PubMed

Huang, Shih-Horng; Wu, Jiahn-Chun; Hwang, Ra-Der; Yeo, Hui-Lin; Wang, Seu-Mei

2003-09-01

Cellular junctions play important roles in cell differentiation, signal transduction, and cell function. This study investigated their function in steroid secretion by adrenal cells. Immunofluorescence staining revealed the presence of gap junctions and adherens junctions between adrenal cells. The major gap junction protein, connexin43, was seen as a linear dotted pattern of the typical gap junction plaques, in contrast to alpha-, beta-, and gamma-catenin, which were seen as continuous, linear staining of cell-cell adherens junction. Treatment with 18beta-glycyrrhetinic acid, a gap junction inhibitor, reduced the immunoreactivity of these proteins in a time- and dose-dependent manner, and caused the gap junction and adherens junction to separate longitudinally from the cell-cell contact sites, indicating the structural interdependency of these two junctions. Interestingly, 18beta-glycyrrhetinic acid stimulated a two- to three-fold increase in steroid production in these adrenal cells lacking intact cell junctions. These data raise the question of the necessity for cell communication for the endocrine function of adrenal cells. Pharmacological analyses indicated that the steroidogenic effect of 18beta-glycyrrhetinic acid was partially mediated by extracellular signal-related kinase and calcium/calmodulin-dependent kinase, a pathway distinct from the protein kinase A signaling pathway already known to mediate steroidogenesis in adrenal cells. Copyright 2003 Wiley-Liss, Inc.

Gap junctions modulate glioma invasion by direct transfer of microRNA.

PubMed

Hong, Xiaoting; Sin, Wun Chey; Harris, Andrew L; Naus, Christian C

2015-06-20

The invasiveness of high-grade glioma is the primary reason for poor survival following treatment. Interaction between glioma cells and surrounding astrocytes are crucial to invasion. We investigated the role of gap junction mediated miRNA transfer in this context. By manipulating gap junctions with a gap junction inhibitor, siRNAs, and a dominant negative connexin mutant, we showed that functional glioma-glioma gap junctions suppress glioma invasion while glioma-astrocyte and astrocyte-astrocyte gap junctions promote it in an in vitro transwell invasion assay. After demonstrating that glioma-astrocyte gap junctions are permeable to microRNA, we compared the microRNA profiles of astrocytes before and after co-culture with glioma cells, identifying specific microRNAs as candidates for transfer through gap junctions from glioma cells to astrocytes. Further analysis showed that transfer of miR-5096 from glioma cells to astrocytes is through gap junctions; this transfer is responsible, in part, for the pro-invasive effect. Our results establish a role for glioma-astrocyte gap junction mediated microRNA signaling in modulation of glioma invasive behavior, and that gap junction coupling among astrocytes magnifies the pro-invasive signaling. Our findings reveal the potential for therapeutic interventions based on abolishing alteration of stromal cells by tumor cells via manipulation of microRNA and gap junction channel activity.

Gap junctions modulate glioma invasion by direct transfer of microRNA

PubMed Central

Hong, Xiaoting; Sin, Wun Chey; Harris, Andrew L.; Naus, Christian C.

2015-01-01

The invasiveness of high-grade glioma is the primary reason for poor survival following treatment. Interaction between glioma cells and surrounding astrocytes are crucial to invasion. We investigated the role of gap junction mediated miRNA transfer in this context. By manipulating gap junctions with a gap junction inhibitor, siRNAs, and a dominant negative connexin mutant, we showed that functional glioma-glioma gap junctions suppress glioma invasion while glioma-astrocyte and astrocyte-astrocyte gap junctions promote it in an in vitro transwell invasion assay. After demonstrating that glioma-astrocyte gap junctions are permeable to microRNA, we compared the microRNA profiles of astrocytes before and after co-culture with glioma cells, identifying specific microRNAs as candidates for transfer through gap junctions from glioma cells to astrocytes. Further analysis showed that transfer of miR-5096 from glioma cells to astrocytes is through gap junctions; this transfer is responsible, in part, for the pro-invasive effect. Our results establish a role for glioma-astrocyte gap junction mediated microRNA signaling in modulation of glioma invasive behavior, and that gap junction coupling among astrocytes magnifies the pro-invasive signaling. Our findings reveal the potential for therapeutic interventions based on abolishing alteration of stromal cells by tumor cells via manipulation of microRNA and gap junction channel activity. PMID:25978028

Genetics Home Reference: DNMT3A overgrowth syndrome

MedlinePlus

... eyes (narrowed palpebral fissures). Additionally, the upper front teeth are often larger than normal. Intellectual disability in DNMT3A overgrowth syndrome ranges from mild to severe. Individuals may have features of autism spectrum disorder , which are characterized by impaired communication ...

CSReport: A New Computational Tool Designed for Automatic Analysis of Class Switch Recombination Junctions Sequenced by High-Throughput Sequencing.

PubMed

Boyer, François; Boutouil, Hend; Dalloul, Iman; Dalloul, Zeinab; Cook-Moreau, Jeanne; Aldigier, Jean-Claude; Carrion, Claire; Herve, Bastien; Scaon, Erwan; Cogné, Michel; Péron, Sophie

2017-05-15

B cells ensure humoral immune responses due to the production of Ag-specific memory B cells and Ab-secreting plasma cells. In secondary lymphoid organs, Ag-driven B cell activation induces terminal maturation and Ig isotype class switch (class switch recombination [CSR]). CSR creates a virtually unique IgH locus in every B cell clone by intrachromosomal recombination between two switch (S) regions upstream of each C region gene. Amount and structural features of CSR junctions reveal valuable information about the CSR mechanism, and analysis of CSR junctions is useful in basic and clinical research studies of B cell functions. To provide an automated tool able to analyze large data sets of CSR junction sequences produced by high-throughput sequencing (HTS), we designed CSReport, a software program dedicated to support analysis of CSR recombination junctions sequenced with a HTS-based protocol (Ion Torrent technology). CSReport was assessed using simulated data sets of CSR junctions and then used for analysis of Sμ-Sα and Sμ-Sγ1 junctions from CH12F3 cells and primary murine B cells, respectively. CSReport identifies junction segment breakpoints on reference sequences and junction structure (blunt-ended junctions or junctions with insertions or microhomology). Besides the ability to analyze unprecedentedly large libraries of junction sequences, CSReport will provide a unified framework for CSR junction studies. Our results show that CSReport is an accurate tool for analysis of sequences from our HTS-based protocol for CSR junctions, thereby facilitating and accelerating their study. Copyright © 2017 by The American Association of Immunologists, Inc.

Regulation of gap junctional charge selectivity in cells coexpressing connexin 40 and connexin 43.

PubMed

Heyman, Nathanael S; Kurjiaka, David T; Ek Vitorin, Jose F; Burt, Janis M

2009-07-01

Expression of connexin 40 (Cx40) and Cx43 in cardiovascular tissues varies as a function of age, injury, and development with unknown consequences on the selectivity of junctional communication and its acute regulation. We investigated the PKC-dependent regulation of charge selectivity in junctions composed of Cx43, Cx40, or both by simultaneous assessment of junctional permeance rate constants (B(dye)) for dyes of similar size but opposite charge, N,N,N-trimethyl-2-[methyl-(7-nitro-2,1,3-benzoxadiol-4-yl)amino]ethanaminium (NBD-M-TMA; +1) and Alexa 350 (-1). The ratio of dye rate constants (B(NBD-M-TMA)/B(Alexa 350)) indicated that Cx40 junctions are cation selective (10.7 +/- 0.5), whereas Cx43 junction are nonselective (1.22 +/- 0.14). In coexpressing cells, a broad range of junctional selectivities was observed with mean cation selectivity increasing as the Cx40 to Cx43 expression ratio increased. PKC activation reduced or eliminated dye permeability of Cx43 junctions without altering their charge selectivity, had no effect on either permeability or charge selectivity of Cx40 junctions, and significantly increased the cation selectivity of junctions formed by coexpressing cells (approaching charge selectivity of Cx40 junctions). Junctions composed of Cx43 truncated at residue 257 (Cx43tr) were also not charge selective, but when Cx43tr was coexpressed with Cx40, a broad range of junctional selectivities that was unaffected by PKC activation was observed. Thus, whereas the charge selectivities of homomeric/homotypic Cx43 and Cx40 junctions appear invariant, the selectivities of junctions formed by cells coexpressing Cx40 and Cx43 vary considerably, reflecting both their relative expression levels and phosphorylation-dependent regulation. Such regulation could represent a mechanism by which coexpressing cells such as vascular endothelium and atrial cells regulate acutely the selective intercellular communication mediated by their gap junctions.

Method of making high breakdown voltage semiconductor device

DOEpatents

Arthur, Stephen D.; Temple, Victor A. K.

1990-01-01

A semiconductor device having at least one P-N junction and a multiple-zone junction termination extension (JTE) region which uniformly merges with the reverse blocking junction is disclosed. The blocking junction is graded into multiple zones of lower concentration dopant adjacent termination to facilitate merging of the JTE to the blocking junction and placing of the JTE at or near the high field point of the blocking junction. Preferably, the JTE region substantially overlaps the graded blocking junction region. A novel device fabrication method is also provided which eliminates the prior art step of separately diffusing the JTE region.

Methods for the fabrication of thermally stable magnetic tunnel junctions

DOEpatents

Chang, Y Austin [Middleton, WI; Yang, Jianhua J [Madison, WI; Ladwig, Peter F [Hutchinson, MN

2009-08-25

Magnetic tunnel junctions and method for making the magnetic tunnel junctions are provided. The magnetic tunnel junctions are characterized by a tunnel barrier oxide layer sandwiched between two ferromagnetic layers. The methods used to fabricate the magnetic tunnel junctions are capable of completely and selectively oxidizing a tunnel junction precursor material using an oxidizing gas containing a mixture of gases to provide a tunnel junction oxide without oxidizing the adjacent ferromagnetic materials. In some embodiments the gas mixture is a mixture of CO and CO.sub.2 or a mixture of H.sub.2 and H.sub.2O.

Possible Involvement of Tight Junctions, Extracellular Matrix and Nuclear Receptors in Epithelial Differentiation

PubMed Central

Ichikawa-Tomikawa, Naoki; Sugimoto, Kotaro; Satohisa, Seiro; Nishiura, Keisuke; Chiba, Hideki

2011-01-01

Tight junctions are intercellular junctions localized at the most apical end of the lateral plasma membrane. They consist of four kinds of transmembrane proteins (occludin, claudins, junctional adhesion molecules, and tricellulin) and huge numbers of scaffolding proteins and contribute to the paracellular barrier and fence function. The mutation and deletion of these proteins impair the functions of tight junctions and cause various human diseases. In this paper, we provide an overview of recent studies on transmembrane proteins of tight junctions and highlight the functional significance of tight junctions, extracellular matrix, and nuclear receptors in epithelial differentiation. PMID:22162632

Gap junction- and hemichannel-independent actions of connexins.

PubMed

Jiang, Jean X; Gu, Sumin

2005-06-10

Connexins have been known to be the protein building blocks of gap junctions and mediate cell-cell communication. In contrast to the conventional dogma, recent evidence suggests that in addition to forming gap junction channels, connexins possess gap junction-independent functions. One important gap junction-independent function for connexins is to serve as the major functional component for hemichannels, the un-apposed halves of gap junctions. Hemichannels, as independent functional units, play roles that are different from that of gap junctions in the cell. The other functions of connexins appear to be gap junction- and hemichannel-independent. Published studies implicate the latter functions of connexins in cell growth, differentiation, tumorigenicity, injury, and apoptosis, although the mechanistic aspects of these actions remain largely unknown. In this review, gap junction- and hemichannel-independent functions of connexins are summarized, and the molecular mechanisms underlying these connexin functions are speculated and discussed.

Atomic-scaled characterization of graphene PN junctions

NASA Astrophysics Data System (ADS)

Zhou, Xiaodong; Wang, Dennis; Dadgar, Ali; Agnihotri, Pratik; Lee, Ji Ung; Reuter, Mark C.; Ross, Frances M.; Pasupathy, Abhay N.

Graphene p-n junctions are essential devices for studying relativistic Klein tunneling and the Veselago lensing effect in graphene. We have successfully fabricated graphene p-n junctions using both lithographically pre-patterned substrates and the stacking of vertical heterostructures. We then use our 4-probe STM system to characterize the junctions. The ability to carry out scanning electron microscopy (SEM) in our STM instrument is essential for us to locate and measure the junction interface. We obtain both the topography and dI/dV spectra at the junction area, from which we track the shift of the graphene chemical potential with position across the junction interface. This allows us to directly measure the spatial width and roughness of the junction and its potential barrier height. We will compare the junction properties of devices fabricated by the aforementioned two methods and discuss their effects on the performance as a Veselago lens.

Molecular mechanisms regulating formation, trafficking and processing of annular gap junctions.

PubMed

Falk, Matthias M; Bell, Cheryl L; Kells Andrews, Rachael M; Murray, Sandra A

2016-05-24

Internalization of gap junction plaques results in the formation of annular gap junction vesicles. The factors that regulate the coordinated internalization of the gap junction plaques to form annular gap junction vesicles, and the subsequent events involved in annular gap junction processing have only relatively recently been investigated in detail. However it is becoming clear that while annular gap junction vesicles have been demonstrated to be degraded by autophagosomal and endo-lysosomal pathways, they undergo a number of additional processing events. Here, we characterize the morphology of the annular gap junction vesicle and review the current knowledge of the processes involved in their formation, fission, fusion, and degradation. In addition, we address the possibility for connexin protein recycling back to the plasma membrane to contribute to gap junction formation and intercellular communication. Information on gap junction plaque removal from the plasma membrane and the subsequent processing of annular gap junction vesicles is critical to our understanding of cell-cell communication as it relates to events regulating development, cell homeostasis, unstable proliferation of cancer cells, wound healing, changes in the ischemic heart, and many other physiological and pathological cellular phenomena.

ABUNDANCE AND ULTRASTRUCTURAL DIVERSITY OF NEURONAL GAP JUNCTIONS IN THE OFF AND ON SUBLAMINAE OF THE INNER PLEXIFORM LAYER OF RAT AND MOUSE RETINA

PubMed Central

KAMASAWA, N.; FURMAN, C. S.; DAVIDSON, K. G. V.; SAMPSON, J. A.; MAGNIE, A. R.; GEBHARDT, B. R.; KAMASAWA, M.; YASUMURA, T.; ZUMBRUNNEN, J. R.; PICKARD, G. E.; NAGY, J. I.; RASH, J. E.

2007-01-01

Neuronal gap junctions are abundant in both outer and inner plexiform layers of the mammalian retina. In the inner plexiform layer (IPL), ultrastructurally-identified gap junctions were reported primarily in the functionally-defined and anatomically-distinct ON sublamina, with few reported in the OFF sublamina. We used freeze-fracture replica immunogold labeling and confocal microscopy to quantitatively analyze the morphologies and distributions of neuronal gap junctions in the IPL of adult rat and mouse retina. Under “baseline” conditions (photopic illumination/general anesthesia), 649 neuronal gap junctions immunogold-labeled for connexin36 were identified in rat IPL, of which 375 were photomapped to OFF vs. ON sublaminae. In contrast to previous reports, the volume-density of gap junctions was equally abundant in both sublaminae. Five distinctive morphologies of gap junctions were identified: conventional crystalline and non-crystalline “plaques” (71% and 3%), plus unusual “string” (14%), “ribbon” (7%) and “reticular” (2%) forms. Plaque and reticular gap junctions were distributed throughout the IPL. However, string and ribbon gap junctions were restricted to the OFF sublamina, where they represented 48% of gap junctions in that layer. In string and ribbon junctions, curvilinear strands of connexons were dispersed over 5 to 20 times the area of conventional plaques having equal numbers of connexons. To define morphologies of gap junctions under different light-adaptation conditions, we examined an additional 1150 gap junctions from rats and mice prepared after 30 min of photopic, mesopic and scotopic illumination, with and without general anesthesia. Under these conditions, string and ribbon gap junctions remained abundant in the OFF sublamina and absent in the ON sublamina. Abundant gap junctions in the OFF sublamina of these two rodents with rod-dominant retinas revealed previously-undescribed but extensive pathways for inter-neuronal communication; and the wide dispersion of connexons in string and ribbon gap junctions suggests unique structural features of gap junctional coupling in the OFF vs. ON sublamina. PMID:17010526

Geologically recent small-scale surface features in Meridiani Planum and Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Horne, David

2014-05-01

Enigmatic small scale (<1m) depositional and erosional features have been imaged at several locations in the equatorial Meridiani Planum region by the rover Opportunity. They occur in loose, dark basaltic sands partly covering exposures of light-toned bedrock. Leveed fissures are narrow, elongate, steep-sided depressions flanked by raised levees or half-cones of soil, typically 2-10 cm wide and up to 50 cm long in most cases. Some cross-cut and are therefore younger than eolian ripples thought to have last been active c. 50,000 years ago. Gutters are elongate, straight or sinuous surface depressions, typically 2-10cm wide and 1-5 cm deep, sometimes internally terraced or with a hollow near one end, and in one case seem to give way to small depositional fans downslope; they have the appearance of having been formed by liquid flow rather than by wind erosion. Leveed fissures were imaged at more than 25 locations by Opportunity between 2004 and 2013, particularly near the rims of Endurance, Erebus and Endeavour craters, but also on the plains between Santa Maria and Endeavour craters; sharply-defined gutters are less common but examples were imaged close to the rim of Endurance and on the approach to Endeavour, whereas subdued, possibly wind-softened examples are more widespread. Scrutiny of images obtained by the rover Spirit in Gusev Crater between 2004 and 2010 has so far failed to find any leveed fissures or gutters, but examples of both types of features, as well as numerous small holes suggestive of surface sediment falling into underlying voids, were imaged by the rover Curiosity in the Yellowknife Bay region of Gale Crater during 2013. Leveed fissures appear to have been formed by venting from beneath. Ground disturbance by the rover can be ruled out in many cases by the appearance of features in images taken before close approach. Blowholes seem plausible close to crater rims (where wind might enter a connected void system through a crater wall) but less so in plains areas between craters. Fumaroles seem unlikely since there is no other evidence of geologically young volcanic activity in the region. There is evidence elsewhere that contemporary ground-ice thaw and consequent transient surface run-off may occur occasionally under present conditions in low, near-equatorial latitudes on Mars; short-lived (even for just a few minutes) meltwater emission and flow at the surface could erode gutters before evaporating. The decomposition of buried pockets of methane clathrates, which theoretical considerations suggest might be present and stable even in equatorial regions, could give rise to both methane venting (leveed fissures) and transient surface water (gutters). Another possibility is the decomposition, due to local changes in thermal conditions, of hydrated magnesium sulphates in the bedrock, releasing liquid water. Whatever their explanation, these features hint at previously unrecognized, young martian surface processes which may even be active at the present day; in this context, the apparent downslope extension of a discrete dark dust streak on Burns Cliff (inside Endurance Crater), during Opportunity's approach to that locality, is particularly thought-provoking.

Arrested diatreme development: Standing Rocks East, Hopi Buttes, Navajo Nation, USA

NASA Astrophysics Data System (ADS)

Lefebvre, Nathalie S.; White, James D. L.; Kjarsgaard, Bruce A.

2016-01-01

Maar-diatreme volcanoes, defined by their relatively large pyroclastic debris-filled subsurface structures and craters that cut into the pre-eruptive land surface, are typically found in small-volume mafic to ultramafic monogenetic volcanic fields. Diatremes are associated with strong explosions throughout most of their development, focused along feeder dikes and generally attributed to magma-water interaction, or high magmatic volatiles. Detailed mapping of the magnificently exposed Standing Rocks East (SRE) diatreme shows evidence of additional eruptive complexity, and offers new insights into how the plumbing and vent structures of small-volume volcanoes evolve during an eruption. SRE is part of a larger, basanitic volcanic complex that includes several diatremes formed along a series of irregular, offset NW-SE trending dikes exposed 300 m below the pre-eruptive land surface. Its similarly oriented elliptical-shaped diatreme structure comprises predominantly country rock lithic-rich breccia of coarse inhomogeneously mixed wall-rock blocks sourced from above and below the current surface, plus sparse juvenile material. Domains of pyroclastic deposits crosscut the country rock breccia deposits, and the best exposed is the NW massif rising 35 m above the current erosional surface. It represents a cross-section of an evolving crater floor, and comprises matrix-rich lapilli tuff and spatter deposits cut by irregularly distributed dikes, some with very complex textures. The most significant deposit, in terms of volume, is an unbedded lapilli tuff that is poorly sorted and has a well-mixed population of wall-rock and juvenile clast varieties, thus resembling deposits typical of diatremes. It is overlain by and locally intercalated with spatter deposits, and this irregular contact demarcates the base of what was during eruption an uneven, evolving crater floor. The generally massive, variably welded spatter deposits constitute mostly lapilli-sized juvenile clasts with fluidal, folded-over shapes and ropy surfaces, subordinate thermally altered wall-rock and variegated domains of lapilli tuff. SRE shows a progressive transition from fissure to diatreme, and overall evolution from more explosive to weakly explosive eruption styles recorded at the conduit-crater transition. Diatreme development was initiated by deep-quarrying explosive eruptions along a fissure to form the country rock-rich breccia. Only parts of the fissure remained active as magma feeding the highly explosive eruptions along the fissure localized into discrete point sources forming the matrix-rich lapilli tuff deposits. These superimposed deposits record the passage of multiple debris-jets and subvertical fallback from shallow cratering arising from explosions triggered by magma-water interaction at numerous, discrete sites. However, instead of continuing to build a well-formed diatreme, the system switched to weak spattering with intermittent explosive activity and near-surface dike emplacement into the unconsolidated anisotropic, pyroclastic debris of the crater floor. Dominant spatter from strombolian-style bursts accumulated on the topographically varied, evolving unstable syn-eruptive crater floor, and led to local failure and remobilization. This study demonstrates how the combination of fissure behavior and sensitivity of the shallow plumbing system to local conditions during an eruption can lead to a decrease in eruptive footprint within the diatreme structure, and an overall decrease in explosivity resulting in the arrested development of an immature diatreme.

Density analysis of magmatic and phreatomagmatic phases of the 934 AD Eldgjá Eruption, southern Iceland

NASA Astrophysics Data System (ADS)

Moreland, William; Thordarson, Thorvaldur

2014-05-01

Eldgjá is a ~75 km long volcanic fissure vent system associated with the Katla volcanic system in southern Iceland, formed during an eruption in the mid-tenth century. The fissure is of the mixed-cone row type and produced both large lava fields and a widespread basaltic tephra deposit. Proximal tephra fall deposits are up to 4 m thick and contain numerous fall units of varying thickness which run parallel to the fissure, indicating many sources of eruption. The lower-most fall units thicken towards Mýrdalsjökull, demonstrating that the initial explosive phases took place within the glacier. Later fall units generally thicken towards the northeast with dispersal axes indicating origin at the more easterly segments of the Eldgjá vent system and a stepwise migration in an easterly direction. Both magmatic and phreatomagmatic explosive activity occurred along the vent system, where phreatomagmatic activity is confined to fissure segments within the Mýrdalsjökull glacier. Two key sections, chosen to represent magmatic and phreatomagmatic deposits, were logged and sampled for density analysis. A section at Skælingar, half a kilometre southeast of Eldgjá Proper was chosen to represent the magmatic products. It is 3.70 m thick and contains 9 fall-units including a distinct bomb-layer. The phreatomagmatic products are represented by a section from Stóragil, 20 km north-northeast of the Katla caldera and the sampled section is 1.12 m thick. Density analysis involves selecting 100 clasts 8-32 mm in diameter from <5 cm layers within the sub-units of each section. These clasts are then weighed, sealed and then weighed again in water to calculate their volume by Archimedes' principle and therefore their density, from which vesicularity can be calculated. The results were then plotted as histograms and compared with the section logs. The magmatic samples have unimodal, normal vesicularity distributions with typical modal values of 60-70% and a span of ~40%. Several of the samples have weakly negatively skewed distributions - the bomb layer has a plateau-like vesicularity distribution and a span of 51% - indicating that outgassed magma was also involved in the explosive activity. This outgassed portion of the tephra deposits is best explained by the pulsating explosions on the same fissure segment. The section at Stóragil contains both phreatomagmatic and magmatic products. The phreatomagmatic samples exhibit characteristic plateau-like distributions with modal vesicularity between 70-80% and a span of 40-50%. In one of the fall units a gradual change from plateau-like to normal distribution is observed indicating a change from phreatomagmatic to magmatic activity during the course of a single explosive phase. This implies that either gradual change in access of external water to the erupting vents or that the external water source was being exhausted. Thin-sections will be made of clasts in each sample which show extreme vesicularities. SEM photographs will be taken of these and vesicle-size distributions measured by image analysis. These results will also be presented.

Signaling from the Podocyte Intercellular Junction to the Actin Cytoskeleton

PubMed Central

George, Britta; Holzman, Lawrence B.

2012-01-01

Observations of hereditary glomerular disease support the contention that podocyte intercellular junction proteins are essential for junction formation and maintenance. Genetic deletion of most of these podocyte intercellular junction proteins results in foot process effacement and proteinuria. This review focuses on the current understanding of molecular mechanisms by which podocyte intercellular junction proteins such as the Nephrin-Neph1-Podocin receptor complex coordinate cytoskeletal dynamics and thus intercellular junction formation, maintenance and injury-dependent remodeling. PMID:22958485

Visualizing the effect of dynamin inhibition on annular gap vesicle formation and fission

PubMed Central

Nickel, Beth; Boller, Marie; Schneider, Kimberly; Shakespeare, Teresa; Gay, Vernon; Murray, Sandra A.

2013-01-01

Summary Although gap junction plaque assembly has been extensively studied, mechanisms involved in plaque disassembly are not well understood. Disassembly involves an internalization process in which annular gap junction vesicles are formed. These vesicles undergo fission, but the molecular machinery needed for these fissions has not been described. The mechanoenzyme dynamin has been previously demonstrated to play a role in gap junction plaque internalization. To investigate the role of dynamin in annular gap junction vesicle fission, immunocytochemical, time-lapse and transmission electron microscopy were used to analyze SW-13 adrenocortical cells in culture. Dynamin was demonstrated to colocalize with gap junction plaques and vesicles. Dynamin inhibition, by siRNA knockdown or treatment with the dynamin GTPase inhibitor dynasore, increased the number and size of gap junction ‘buds’ suspended from the gap junction plaques. Buds, in control populations, were frequently released to form annular gap junction vesicles. In dynamin-inhibited populations, the buds were larger and infrequently released and thus fewer annular gap junction vesicles were formed. In addition, the number of annular gap junction vesicle fissions per hour was reduced in the dynamin-inhibited populations. We believe this to be the first report addressing the details of annular gap junction vesicle fissions and demonstrating a role of dynamin in this process. This information is crucial for elucidating the relationship between gap junctions, membrane regulation and cell behavior. PMID:23591819

Role of heteromeric gap junctions in the cytotoxicity of cisplatin.

PubMed

Tong, Xuhui; Dong, Shuying; Yu, Meiling; Wang, Qin; Tao, Liang

2013-08-09

In several systems, the presence of gap junctions made of a single connexin has been shown to enhance the cytotoxicity of cisplatin. However, most gap junction channels in vivo appear to be heteromeric (composed of more than one connexin isoform). Here we explore in HeLa cells the cytotoxicity to cisplatin that is enhanced by heteromeric gap junctions composed of Cx26 and Cx32, which have been shown to be more selective among biological permeants than the corresponding homomeric channels. We found that survival and subsequent proliferation of cells exposed to cisplatin were substantially reduced when gap junctions were present than when there were no gap junctions. Functional inhibition of gap junctions by oleamide enhanced survival/proliferation, and enhancement of gap junctions by retinoic acid decreased survival/proliferation. These effects occurred only in high density cultures, and the treatments were without effect when there was no opportunity for gap junction formation. The presence of functional gap junctions enhanced apoptosis as reflected in markers of both early-stage and late-stage apoptosis. Furthermore, analysis of caspases 3, 8 and 9 showed that functional gap junctions specifically induced apoptosis by the mitochondrial pathway. These results demonstrate that heteromeric Cx26/Cx32 gap junctions increase the cytotoxicity of cisplatin by induction of apoptosis via the mitochondrial pathway. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Visualizing the effect of dynamin inhibition on annular gap vesicle formation and fission.

PubMed

Nickel, Beth; Boller, Marie; Schneider, Kimberly; Shakespeare, Teresa; Gay, Vernon; Murray, Sandra A

2013-06-15

Although gap junction plaque assembly has been extensively studied, mechanisms involved in plaque disassembly are not well understood. Disassembly involves an internalization process in which annular gap junction vesicles are formed. These vesicles undergo fission, but the molecular machinery needed for these fissions has not been described. The mechanoenzyme dynamin has been previously demonstrated to play a role in gap junction plaque internalization. To investigate the role of dynamin in annular gap junction vesicle fission, immunocytochemical, time-lapse and transmission electron microscopy were used to analyze SW-13 adrenocortical cells in culture. Dynamin was demonstrated to colocalize with gap junction plaques and vesicles. Dynamin inhibition, by siRNA knockdown or treatment with the dynamin GTPase inhibitor dynasore, increased the number and size of gap junction 'buds' suspended from the gap junction plaques. Buds, in control populations, were frequently released to form annular gap junction vesicles. In dynamin-inhibited populations, the buds were larger and infrequently released and thus fewer annular gap junction vesicles were formed. In addition, the number of annular gap junction vesicle fissions per hour was reduced in the dynamin-inhibited populations. We believe this to be the first report addressing the details of annular gap junction vesicle fissions and demonstrating a role of dynamin in this process. This information is crucial for elucidating the relationship between gap junctions, membrane regulation and cell behavior.

A WAVE2–Arp2/3 actin nucleator apparatus supports junctional tension at the epithelial zonula adherens

PubMed Central

Verma, Suzie; Han, Siew Ping; Michael, Magdalene; Gomez, Guillermo A.; Yang, Zhe; Teasdale, Rohan D.; Ratheesh, Aparna; Kovacs, Eva M.; Ali, Radiya G.; Yap, Alpha S.

2012-01-01

The epithelial zonula adherens (ZA) is a specialized adhesive junction where actin dynamics and myosin-driven contractility coincide. The junctional cytoskeleton is enriched in myosin II, which generates contractile force to support junctional tension. It is also enriched in dynamic actin filaments, which are replenished by ongoing actin assembly. In this study we sought to pursue the relationship between actin assembly and junctional contractility. We demonstrate that WAVE2–Arp2/3 is a major nucleator of actin assembly at the ZA and likely acts in response to junctional Rac signaling. Furthermore, WAVE2–Arp2/3 is necessary for junctional integrity and contractile tension at the ZA. Maneuvers that disrupt the function of either WAVE2 or Arp2/3 reduced junctional tension and compromised the ability of cells to buffer side-to-side forces acting on the ZA. WAVE2–Arp2/3 disruption depleted junctions of both myosin IIA and IIB, suggesting that dynamic actin assembly may support junctional tension by facilitating the local recruitment of myosin. PMID:23051739

A WAVE2-Arp2/3 actin nucleator apparatus supports junctional tension at the epithelial zonula adherens.

PubMed

Verma, Suzie; Han, Siew Ping; Michael, Magdalene; Gomez, Guillermo A; Yang, Zhe; Teasdale, Rohan D; Ratheesh, Aparna; Kovacs, Eva M; Ali, Radiya G; Yap, Alpha S

2012-12-01

The epithelial zonula adherens (ZA) is a specialized adhesive junction where actin dynamics and myosin-driven contractility coincide. The junctional cytoskeleton is enriched in myosin II, which generates contractile force to support junctional tension. It is also enriched in dynamic actin filaments, which are replenished by ongoing actin assembly. In this study we sought to pursue the relationship between actin assembly and junctional contractility. We demonstrate that WAVE2-Arp2/3 is a major nucleator of actin assembly at the ZA and likely acts in response to junctional Rac signaling. Furthermore, WAVE2-Arp2/3 is necessary for junctional integrity and contractile tension at the ZA. Maneuvers that disrupt the function of either WAVE2 or Arp2/3 reduced junctional tension and compromised the ability of cells to buffer side-to-side forces acting on the ZA. WAVE2-Arp2/3 disruption depleted junctions of both myosin IIA and IIB, suggesting that dynamic actin assembly may support junctional tension by facilitating the local recruitment of myosin.

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

Schimmenti, L.A.; Berry, S.A.; Tuchman, M.

The authors report on a male infant with developmental delay, growth failure, hypotonia, dolichocephaly, hypoplastic midface, epicanthal folds, down-slanting palpebral fissures, foveal hypoplasia, tracheomalacia, pectus excavatum, supraventricular tachycardia, gut malrotation, hypospadias, talipes equinovarus, short third metatarsals, capillary hemangiomata, and a de novo terminal deletion at 9q34.3.

Earthquakes in the New Zealand Region.

ERIC Educational Resources Information Center

Wallace, Cleland

1995-01-01

Presents a thorough overview of earthquakes in New Zealand, discussing plate tectonics, seismic measurement, and historical occurrences. Includes 10 figures illustrating such aspects as earthquake distribution, intensity, and fissures in the continental crust. Tabular data includes a list of most destructive earthquakes and descriptive effects…

40 CFR 401.11 - General definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Environmental Protection Agency. (d) The term point source means any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure... which pollutants are or may be discharged. (e) The term new source means any building, structure...

Disruption of gap junctions attenuates aminoglycoside-elicited renal tubular cell injury.

PubMed

Yao, Jian; Huang, Tao; Fang, Xin; Chi, Yuan; Zhu, Ying; Wan, Yigang; Matsue, Hiroyuki; Kitamura, Masanori

2010-08-01

Gap junctions play important roles in the regulation of cell phenotype and in determining cell survival after various insults. Here, we investigated the role of gap junctions in aminoglycoside-induced injury to renal tubular cells. Two tubular epithelial cell lines NRK-E52 and LLC-PK1 were compared for gap junction protein expression and function by immunofluorescent staining, Western blot and dye transfer assay. Cell viability after exposure to aminoglycosides was evaluated by WST assay. Gap junctions were modulated by transfection of the gap junction protein, connexin 43 (Cx43), use of Cx43 siRNA and gap junction inhibitors. NRK-E52 cells expressed abundant Cx43 and were functionally coupled by gap junctional intercellular communication (GJIC). Exposure of NRK-E52 cells to aminoglycosides, G418 and hygromycin, increased Cx43 phosphorylation and GJIC. The aminoglycosides also decreased cell viability that was prevented by gap junction inhibitors and Cx43 siRNA. LLC-PK1 cells were gap junction-deficient and resistant to aminoglycoside-induced cytotoxicity. Over-expression of a wild-type Cx43 converted LLC-PK1 cells to a drug-sensitive phenotype. The gap junction inhibitor alpha-glycyrrhetinic acid (alpha-GA) activated Akt in NRK-E52 cells. Inhibition of the Akt pathway enhanced cell toxicity to G418 and abolished the protective effects of alpha-GA. In addition, gentamycin-elicited cytotoxicity in NRK-E52 cells was also significantly attenuated by alpha-GA. Gap junctions contributed to the cytotoxic effects of aminoglycosides. Modulation of gap junctions could be a promising approach for prevention and treatment of aminoglycoside-induced renal tubular cell injury.

Ion release and in vitro enamel fluoride uptake associated with pit and fissure sealants containing microencapsulated remineralizing agents.

PubMed

Burbank, Brant D; Cooper, Ryan L; Kava, Alyssa; Hartjes, Jennifer M; McHale, William A; Latta, Mark A; Gross, Stephen M

2017-04-01

To determine if pit-and-fissure sealants with microencapsulated remineralizing agents with sustained release of fluoride, calcium and phosphate ions could promote enamel fluoride uptake by demineralized tooth structure. Sealants that contained 5 w/w% microcapsules with aqueous solutions of 5M Ca(NO3)2 or 0.8M NaF or 6.0M K2HPO4 or a mixture of all three were prepared. Ion release profiles were measured as a function of time. Enamel fluoride uptake by demineralized tooth structure was determined. Sustained release of fluoride, calcium and phosphate ions from a sealant was demonstrated. Fluoride uptake by demineralized enamel was significantly increased compared to a control sealant manufactured without microcapsules (P< 0.01). Bovine enamel that contained 2.2±2.1 µg F/g of enamel prior to exposure to a sealant without microcapsules had 2.3±0.5 after 90 days. Enamel exposed to sealant with 5w/% NaF microcapsules went from 3.5±3.5 µg F/g of enamel prior to exposure to 148±76 after 90 days. Enamel exposed to sealant with 2 w/w% NaF, 2 w/w% Ca(NO3)2 and 1 w/w% K2HPO4 microcapsules went from 1.7±0.7 µg F/g of enamel prior to exposure to 190±137 after 90 days. Sealants with encapsulated remineralizing agents were capable of releasing biologically available fluoride, calcium, and phosphate ions. Incorporation of these microcapsules in pit and fissure sealants is a promising method for remineralization determined by enamel fluoride uptake measurements.

Translational bypass of nonsense mutations in zebrafish rep1, pax2.1 and lamb1 highlights a viable therapeutic option for untreatable genetic eye disease.

PubMed

Moosajee, Mariya; Gregory-Evans, Kevin; Ellis, Charles D; Seabra, Miguel C; Gregory-Evans, Cheryl Y

2008-12-15

The extensive molecular genetic heterogeneity seen with inherited eye disease is a major barrier to the development of gene-based therapeutics. The underlying molecular pathology in a considerable proportion of these diseases however are nonsense mutations leading to premature termination codons. A therapeutic intervention targeted at this abnormality would therefore potentially be relevant to a wide range of inherited eye diseases. We have taken advantage of the ability of aminoglycoside drugs to suppress such nonsense mutations and partially restore full-length, functional protein in a zebrafish model of choroideraemia (chm(ru848); juvenile chorio-retinal degeneration) and in two models of ocular coloboma (noi(tu29a) and gup(m189); congenital optic fissure closure defects). In vitro cell-based assays showed significant readthrough with two drugs, gentamicin and paromomycin, which was confirmed by western blot and in vitro prenylation assays. The presence of either aminoglycoside during zebrafish development in vivo showed remarkable prevention of mutant ocular phenotypes in each model and a reduction in multisystemic defects leading to a 1.5-1.7-fold increase in survival. We also identified a significant reduction in abnormal cell death shown by TUNEL assay. To test the hypothesis that optic fissure closure was apoptosis-dependent, the anti-apoptotic agents, curcumin and zVAD-fmk, were tested in gup(m189) embryos. Both drugs were found to reduce the size of the coloboma, providing molecular evidence that cell death is required for optic fissure remodelling. These findings draw attention to the value of zebrafish models of eye disease as useful preclinical drug screening tools in studies to identify molecular mechanisms amenable to therapeutic intervention.

Time Trends, Clinical Characteristics, and Risk Factors of Chronic Anal Fissure Among a National Cohort of Patients with Inflammatory Bowel Disease.

PubMed

Malaty, Hoda M; Sansgiry, Shubhada; Artinyan, Avo; Hou, Jason K

2016-03-01

Chronic anal fissure (CAF) is a common problem that causes significant morbidity. Little is known about the risk factors of CAF among patients with inflammatory bowel disease (IBD). To study the clinical characteristics and prevalence of CAF among a cohort of IBD patients. We performed a population-based study on IBD patients from the National Veterans Affairs administrative datasets from 1998 to 2011. IBD and AF were identified by ICD-9 diagnosis codes. We identified 60,376 patients with IBD between the ages of 18-90 years, 94% males, 59% diagnosed with ulcerative colitis (UC), and 88% were Caucasians. The overall prevalence of CAF was 4% for both males and females. African Americans (AA) were two times more likely to have CAF compared to Caucasians (8 vs. 4%; OR 2.0, 95% CI 1.6-20.2, p = 0.0001) or Hispanics (8 vs. 4.8%; OR 2.1, 95% CI 1.4-25.2, p = 0.0001). The prevalence of CAF significantly dropped with age from 7% at age group 20-50 to 1.5% at 60-90 (p = 0.0001). CD patients were two times more likely to have CAF than UC patients (6 vs. 3%; OR 1.9, 95% CI 1.5-18.2, p = 0.0001). The initial diagnosis of CAF occurred within 14 years after the initial diagnosis of IBD in 74.5% patients. CAF is more prevalent among IBD than what is reported in the general population and diagnosed after the diagnosis of IBD. CAF is more prevalent among patients with CD, younger patients, and AA. The current results lay the groundwork for further outcome studies relate to anal fissure such as utilization, hospitalization, and cost.

Ocular adnexal asymmetry in models: a magazine photograph analysis.

PubMed

Ing, Edsel; Safarpour, Azien; Ing, Tom; Ing, Sabrina

2006-04-01

Symmetry of facial features often correlates with a perception of physical attractiveness, and ophthalmologists are sometimes consulted by patients for eyelid, eyebrow, or orbital asymmetry. Our objective was to determine the prevalence of ocular adnexal asymmetry among people generally regarded as attractive. The mean width of the horizontal palpebral fissure (MHPF) for both men and women was determined in 40 adult volunteers. Then unobscured, head-on photographs of models looking in the primary position were digitally scanned from popular magazines. Eyelid height, eyelid folds, eyebrow height, medial canthus to midline distance, pupil to midline distance, and orbital dystopia measurements were made. After the measurements from the models were scaled to size by factoring with the MHPF obtained from the volunteers, the results were analyzed by paired samples t test for right-left asymmetry of the ocular adnexal measurements. We also examined for antimongoloid slant in the models. The MHPF of the volunteers was 27+/-1.3 mm for women and 29.6+/-2.0 mm for men. Of 102 magazine photographs analyzed, 55 were women and 47 men. As a group, the models showed a statistically significant asymmetry (p<0.05) in the horizontal fissure width, upper central lid fold, upper temporal lid fold, central eyebrow height, temporal eyebrow height, medial canthal to midline distance, pupil to midline distance, and orbital dystopia. The female models had more eyebrow asymmetry. The male models had more asymmetry at the horizontal fissure and with orbital dystopia. Two male models also had a unilateral antimongoloid slant. Small to moderate amounts of eyelid, eyebrow, and orbital asymmetry were observed in faces generally perceived as attractive. This fact should be considered during preoperative discussions with patients considering oculoplastic surgery.

Dike Propagation Mechanisms from Seismicity Accompanying the 2014 Bárðarbunga-Holuhraun Fissure Eruption, Iceland

NASA Astrophysics Data System (ADS)

Woods, J.; Ágústsdóttir, T.; Greenfield, T. S.; Green, R. G.; White, R. S.; Brandsdottir, B.

2015-12-01

We present data from our dense seismic network which captured in unprecedented detail the micro-seismicity associated with the 2014 dike intrusion from the subglacial Bárðarbunga volcano in central Iceland. Over 30,000 automatically located earthquakes delineate a complex 46 km dike propagation during the days preceding the onset of effusive magmatism at the Holuhraun lava field on 29 August 2014. Approximately 1.5 km3 of lava was erupted, making this the largest eruption in Iceland for over 200 years.Micro-seismicity tracks the lateral migration of the dike, with a concentration of earthquakes in the advancing tip where stresses are greatest, and trailing zones of lesser or no seismicity behind. Onset of an initial 4 hour fissure eruption was accompanied simultaneously by a backward retreat in seismic activity, followed by a gradual re-advance prior to the onset of a second, sustained fissure eruption in the same location on 31 August. Rock fracture mechanisms are determined from fault plane solutions of these seismic events. At the tip of the advancing dike, left-lateral strike-slip faulting parallel to the propagation is dominant, utilising pre-existing lineations and releasing stress accumulated in the brittle layer from rift zone extension. Behind the dike tip, both right-lateral and left-lateral strike-slip earthquakes are found, marking failure of solidifying magma plugs within the dike conduit. Contrary to many models of dike propagation, both normal faulting and failure at high angles to the dike are rare. Furthermore, a distinct lack of seismicity is observed in the 3-4 km region beneath the surface rupture. This suggests that opening is occuring aseismically, with earthquakes focused at the base of the dike near the brittle-ductile boundary.

Fissuration en relaxation des aciers inoxydables austénitiques au voisinage des soudures

NASA Astrophysics Data System (ADS)

Auzoux, Q.; Allais, L.; Gourgues, A. F.; Pineau, A.

2003-03-01

Des fissures intergranulaires peuvent se développer au voisinage des soudures des aciers inoxydables austénitiques lorsqu'ils sont réchauffés dans le domaine de température compris entre 500^{circ}C et 700^{circ}C. A ces températures, les contraintes résiduelles post-soudage se relaxent par déformation viscoplastique. Il peut arriver que ces zones proches de la soudure soient tellement fragiles, qu'elles ne puissent accommoder cette faible déformation. Afin de préciser quelles peuvent être les modifications microstructurales qui conduisent à une telle fragilisation, on a examiné les microstructures de ces zones et révélé ainsi un écrouissage résiduel, responsable d'une forte élévation de la dureté. On a pu reproduire par hypertrempe puis laminage entre 400^{circ}C et 600^{circ}C une microstructure similaire. Des essais mécaniques (traction, fluage, relaxation, sur éprouvettes lisses et pré-fissurées) ont été réalisés à 550^{circ}C et à 600^{circ}C sur ces zones affectées simulées et sur un état de référence hypertrempé. Ils ont montré que l'écrouissage diminuait la ductilité dans le domaine de rupture intergranulaire, sans modifier qualitativement le mécanisme d'endommagement. Pendant la pré-déformation les incompatibilités de déformation entre grains conduiraient à l'existence de contraintes locales élevées qui favoriseraient la germination des cavités intergranulaires.

Selective removal of composite sealants with near-UV laser pulses

NASA Astrophysics Data System (ADS)

Louie, Tiffany M.; Jones, Robert S.; Sarma, Anupama V.; Fried, Daniel

2004-05-01

It is often necessary to replace pit and fissure sealants and composite restorations. This task is complicated by the necessity for complete removal of the remaining composite to enable suitable adhesion of new composite. Previous studies have shown that lasers pulses from a frequency-tripled Nd:YAG laser (355-nm) can selectively remove residual composite after orthodontic bracket removal on enamel surfaces. UV laser light is preferentially absorbed by polymeric resins and the organic content of the tooth enamel. The objective of this study was to determine if such laser pulses are suitable for selective removal of the old composite from pit and fissure sealants and restorations without damaging surrounding sound tissues. Optical coherence tomography was used to acquire optical cross sections of the occlusal topography and peripheral tooth structure non-destructively before application of the sealants, after sealant application, and after sealant removal with 355-nm laser pulses with intensities ranging from 0-10 J/cm2. Thermocouples were used to monitor the temperature in the pulp chamber during composite removal under clinically relevant ablation rates, i.e., 30 Hz and 30 mJ per laser pulse. At an irradiation intensity of 1.3 J/cm2 pit and fissure sealants were completely removed without visible damage to the underlying enamel. At intensities above 1.5 J/cm2, the laser removes the resin layer while at the same time preferentially etching the surface of the enamel. Temperature excursions in the pulp chamber of extracted teeth was limited to less than 5°C if air-cooling was used during the rapid removal (1-2 min) of sealants, water-cooling was not needed. This is the first presentation of a method for the selective removal of composite restorative materials without damage to the underlying sound tooth structure.

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

Leonard, C.M.; Hauser, P.; Weintraub, B.D.

Resistance to thyroid hormone (RTH) is an autosomal dominant disease caused by mutations in the human thyroid receptor beta gene on chromosome 3. Individuals with RTH have an increased incidence of attention deficit hyperactivity disorder (ADHD). The purpose of this study was to search for developmental brain malformations associated with RTH. Forty-three subjects (20 affected males [AM], 23 affected females [AF]) with resistance to thyroid hormone and 32 unaffected first degree relatives (18 unaffected males [UM], 14 unaffected females [UF]) underwent MRI brain scans with a volumetric acquisition that provided 90 contiguous 2 mm thick sagittal images. Films of sixmore » contiguous images beginning at a standard sagittal position lateral to the insula were analyzed by an investigator who was blind with respect to subject characteristics. The presence of extra or missing gyri in the parietal bank of the Sylvian fissure (multimodal association cortex) and multiple Heschl`s transverse gyri (primary auditory cortex) were noted. There was a significantly increased frequency of anomalous Sylvian fissures in the left hemisphere in males with RTH (AM: 70%; AF: 30%; UM: 28% UF: 28%). Also, there was an increased frequency of anomalous Sylvian fissures on the left combined with multiple Heschl`s gyri in either hemisphere in males with RTH (AM: 50%; AF: 9%; UM: 6%; UF: 0%). However, RTH subjects with anomalies did not have an increased frequency of ADHD as compared with RTH subjects with no anomalies. Abnormal thyroid hormone action in the male fetus early during brain development may be associated with grossly observable cerebral anomalies of the left hemisphere. The effects of mutations in the thyroid receptor beta gene provide a model system for studying the complex interaction of genetic and non-genetic factors on brain and behavioral development. 19 refs., 2 figs., 2 tabs.« less

Deep Structure of the Zone of Tolbachik Fissure Eruptions (Kamchatka, Klyuchevskoy Volcano Group): Evidence from a Complex of Geological and Geophysical Data

NASA Astrophysics Data System (ADS)

Kugaenko, Yu. A.; Saltykov, V. A.; Gorvatikov, A. V.; Stepanova, M. Yu.

2018-05-01

With the use of the method of low-frequency microseismic sounding, the configuration of the magmatic feeding system of the Tolbachinsky Dol—a regional zone of areal basaltic volcanism in the southern part of the Klyuchevskoy volcano group in Kamchatka—is studied. The initial data are obtained by a stepby-step recording of the background microseismic noise in 2010-2015 within a thoroughly marked-out survey area covering the zones of fissure eruptions in 1975-1976 and 2012-2013 and, partly, the edifice of the Ploskii (flat) Tolbachik volcano. The depth sections reflecting the distributions of the relative velocities of seismic waves in the Earth's crust are constructed. For a more reliable interpretation of the revealed deep anomalies, the results of independent geological and geophysical studies are used. The ascertained low-velocity structures are closely correlated to the manifestations of present-day volcanism. It is shown that the feeding structure of the Tolbachinsky Dol is spatially heterogeneous, incorporating subvertical and lateral pipeshaped magma conduits, closely spaced magma feeding channels, and shallow magma reservoirs. A longlived local transcrustal magma conducting zone is revealed, and regularities in the deep structure of the feeding systems of fissure eruptions are identified. The configuration of the established subvertical magma conduits permits basalts moving to rise to the surface by different paths, which, inter alia, explains the contrasting magma compositions observed during a single eruption. Thus, based on the instrumental data, it is shown that the magmatic feeding structure of the Tolbachinsky Dol has a number of specific peculiarities and is significantly more complicated than has been previously thought about the areal volcanic fields.

Glass ionomer ART sealants in Chinese school children-6-year results.

PubMed

Holmgren, Christopher J; Lo, Edward C M; Hu, Deyu

2013-09-01

To evaluate longitudinally ART sealants placed in Chinese school children under field conditions. 191 ART sealants were placed in 140 children, aged 11-14 years, by five assistant dentists in four secondary schools in Deyang, Sichuan Province, China. Teeth selected for sealing were those with pits and fissures that were deep or showing early enamel caries. Teeth were excluded if there was obvious cavitation extending into dentine. Standard instruments and procedures for ART sealants were used. The material used was a high-viscosity glass-ionomer (Ketac-Molar, 3MESPE) that was inserted into the pits and fissures with the "press-finger" technique. The status of the sealants was evaluated annually over 6 years after placement by the same examiner who was not involved in the placement of the sealants using explorers, mouth-mirrors and an intra-oral fibre-optic light. No missing sealants were replaced during the study. 107 sealants (56% of the original) were examined after 6 years. The cumulative survival rates of the sealants (partially or fully retained) after 2, 4 and 6 years were 79%, 68% and 59%, respectively. Caries prevention lagged the fall in sealant survival but remained high throughout the study period, being over 90% in the first 4 years and 85% after 6 years. ART sealants placed under field conditions in Chinese schoolchildren have a high retention rate. Missing sealants should be replaced to maintain their preventive efficacy. The sealing of pits and fissures can be an effective caries preventive approach. Resin-based sealants have the disadvantage in that they require an optimal level of moisture control during placement. In children and in outreach situations glass ionomer ART sealants, which are more moisture tolerant, can offer a viable alternative. Copyright © 2013 Elsevier Ltd. All rights reserved.

Imaging subsurface density structure in Luynnier volcanic field, Saudi Arabia, using 3D gravity inversion technique

NASA Astrophysics Data System (ADS)

Aboud, Essam; El-shrief, Adel; Alqahtani, Faisal; Mogren, Saad

2017-04-01

On 19 May, 2009, an earthquake of magnitude (M=5.4) shocked the most volcanically active recent basaltic fields, Luynnier volcanic field, northwestern Saudi Arabia. This event was the largest recorded one since long time ago. Government evacuated the surrounding residents around the epicenter for over 3 months away from any future volcanic activity. The seismic event caused damages to buildings in the village around the epicenter and resulted in surface fissure trending in NNW-SSE direction with about 8 km length. Seismologists from Saudi Geological Survey (SGS) worked out on locating the epicenter and the cause of this earthquake. They collected seismic data from Saudi Geological Surveys Station Network as well as installed broadband seismic stations around the region of the earthquake. They finally concluded that the main cause of the M=5.4 event is dike intrusion at depth of about 5 km (not reached to the surface). In the present work, we carried out detailed ground/airborne gravity survey around the surficial fissure to image the subsurface volcanic structure where about 380 gravity stations were recorded covering the main fissure in an area of 600 km2. Gravity data was analyzed using CET edge detection tools and 3D inversion technique. The results revealed that, there is a magma chamber/body beneath the surface at 5-20 km depth and the main reason for the M=5.4 earthquake is tectonic settings of the Red Sea. Additionally, the area is characterized by set of faults trending in NW direction, parallel to the Red Sea, and most of the volcanic cones were located on faults/contacts implying that, they are structurally controlled. The 8-km surficial crack is extended SE underneath the surface.

Assessing future vent opening locations at the Somma-Vesuvio volcanic complex: 1. A new information geodatabase with uncertainty characterizations

NASA Astrophysics Data System (ADS)

Tadini, A.; Bisson, M.; Neri, A.; Cioni, R.; Bevilacqua, A.; Aspinall, W. P.

2017-06-01

This study presents new and revised data sets about the spatial distribution of past volcanic vents, eruptive fissures, and regional/local structures of the Somma-Vesuvio volcanic system (Italy). The innovative features of the study are the identification and quantification of important sources of uncertainty affecting interpretations of the data sets. In this regard, the spatial uncertainty of each feature is modeled by an uncertainty area, i.e., a geometric element typically represented by a polygon drawn around points or lines. The new data sets have been assembled as an updatable geodatabase that integrates and complements existing databases for Somma-Vesuvio. The data are organized into 4 data sets and stored as 11 feature classes (points and lines for feature locations and polygons for the associated uncertainty areas), totaling more than 1700 elements. More specifically, volcanic vent and eruptive fissure elements are subdivided into feature classes according to their associated eruptive styles: (i) Plinian and sub-Plinian eruptions (i.e., large- or medium-scale explosive activity); (ii) violent Strombolian and continuous ash emission eruptions (i.e., small-scale explosive activity); and (iii) effusive eruptions (including eruptions from both parasitic vents and eruptive fissures). Regional and local structures (i.e., deep faults) are represented as linear feature classes. To support interpretation of the eruption data, additional data sets are provided for Somma-Vesuvio geological units and caldera morphological features. In the companion paper, the data presented here, and the associated uncertainties, are used to develop a first vent opening probability map for the Somma-Vesuvio caldera, with specific attention focused on large or medium explosive events.

Controls on atrazine leaching through a soil-unsaturated fractured limestone sequence at Brévilles, France.

PubMed

Roulier, Stéphanie; Baran, Nicole; Mouvet, Christophe; Stenemo, Fredrik; Morvan, Xavier; Albrechtsen, Hans-Jørgen; Clausen, Liselotte; Jarvis, Nicholas

2006-03-01

The objective of this study was to identify the main controls on atrazine leaching through luvisols and calcisols overlying fissured limestone using the dual-permeability model MACRO. The model parameterisation was based on a combination of direct measurements (e.g. hydraulic properties, adsorption and degradation), literature data and calibration against bromide leaching experiments in field plots. A Monte Carlo sensitivity analysis was carried out for a typical application pattern, considering two different depths of unsaturated limestone (15 and 30 m). MACRO calibrations to the field experiments demonstrated the occurrence of strong macropore flow in the luvisol, while transport in the calcisol could be described by the advection-dispersion equation. MACRO simulations of tritium and atrazine leaching qualitatively matched tritium concentration profiles measured in the limestone and atrazine concentrations measured in piezometers and in aquifer discharge via a spring. The sensitivity analysis suggested that the thickness of the limestone, as well as the transport properties and processes occurring in the unsaturated rock (e.g. matrix vs. fissure flow) will have little significant long-term effect on atrazine leaching, mainly because degradation is very slow in the limestone. No mineralization of atrazine was detected in one-year incubations and a mean half-life of 10 years was assumed in the simulations. Instead, processes occurring in the soil exerted the main control on predicted atrazine leaching, especially variations in the degradation rate and the strength of sorption and macropore flow. However, fissure flow in unsaturated rock is expected to exert a much more significant control on groundwater contamination for compounds that degrade more readily in the deep vadose zone.

Macropolygon morphology, development, and classification on North Panamint and Eureka playas, Death Valley National Park CA

USGS Publications Warehouse

Messina, P.; Stoffer, P.; Smith, W.C.

2005-01-01

Panamint and Eureka playas, both located within Death Valley National Park, exhibit a host of surficial features including fissures, pits, mounds, and plant-covered ridges, representing topographic highs and lows that vary up to 2 m of relief from the playa surface. Aerial photographs reveal that these linear strands often converge to form polygons, ranging in length from several meters to nearly a kilometer. These features stand out in generally dark contrast to the brighter intervening expanse of flat, plant-free, desiccated mud of the typical playa surface. Ground-truth mapping of playa features with differential GPS (Global Positioning System) was conducted in 1999 (North Panamint Valley) and 2002 (Eureka Valley). High-resolution digital maps reveal that both playas possess macropolygons of similar scale and geometry, and that fissures may be categorized into one of two genetic groups: (1) shore-parallel or playa-interior desiccation and shrinkage; and (2) tectonic-induced cracks. Early investigations of these features in Eureka Valley concluded that their origin may have been related to agricultural activity by paleo-Indian communities. Although human artifacts are abundant at each locale, there is no evidence to support the inference that surface features reported on Eureka Playa are anthropogenic in origin. Our assumptions into the genesis of polygons on playas is based on our fortuitous experience of witnessing a fissure in the process of formation on Panamint Playa after a flash flood (May 1999); our observations revealed a paradox that saturation of the upper playa crusts contributes to the establishment of some desiccation features. Follow-up visits to the same feature over 2 yrs' time are a foundation for insight into the evolution and possible longevity of these features. ?? 2005 Elsevier B.V. All rights reserved.

The Benslimane's Artistic Model for Females' Gaze Beauty: An Original Assessment Tool.

PubMed

Benslimane, Fahd; van Harpen, Laura; Myers, Simon R; Ingallina, Fabio; Ghanem, Ali M

2017-02-01

The aim of this paper is to analyze the aesthetic characteristics of the human females' gaze using anthropometry and to present an artistic model to represent it: "The Frame Concept." In this model, the eye fissure represents a painting, and the most peripheral shadows around it represent the frame of this painting. The narrower the frame, the more aesthetically pleasing and youthful the gaze appears. This study included a literature review of the features that make the gaze appear attractive. Photographs of models with attractive gazes were examined, and old photographs of patients were compared to recent photographs. The frame ratio was defined by anthropometric measurements of modern portraits of twenty consecutive Miss World winners. The concept was then validated for age and attractiveness across centuries by analysis of modern female photographs and works of art acknowledged for portraying beautiful young and older women in classical paintings. The frame height inversely correlated with attractiveness in modern female portrait photographs. The eye fissure frame ratio of modern idealized female portraits was similar to that of beautiful female portraits idealized by classical artists. In contrast, the eye fissure frames of classical artists' mothers' portraits were significantly wider than those of beautiful younger women. The Frame Concept is a valid artistic tool that provides an understanding of both the aesthetic and aging characteristics of the female periorbital region, enabling the practitioner to plan appropriate aesthetic interventions. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the A3 online Instructions to Authors. www.springer.com/00266 .

Coincidence of features of emitted THz electromagnetic wave power form a single Josephson junction and different current components

NASA Astrophysics Data System (ADS)

Hamdipour, Mohammad

2017-12-01

By applying a voltage to a Josephson junction, the charge in superconducting layers (S-layers) will oscillate. Wavelength of the charge oscillations in S-layers is related to external current in junction, by increasing the external current, the wavelength will decrease which cause in some currents the wavelength be incommensurate with width of junction, so the CVC shows Fiske like steps. External current throwing along junction has some components, resistive, capacitive and superconducting current, beside these currents there is a current in lateral direction of junction, (x direction). On the other hand, the emitted electromagnetic wave power in THz region is related to AC component of electric field in junction, which itself is related to charge density in S-layers, which is related to currents in the system. So we expect that features of variation of current components reflect the features of emitted THz power form junction. Here we study in detail the superconductive current in a long Josephson junction (JJ), the current voltage characteristics (CVC) of junction and emitted THz power from the system. Then we compare the results. Comparing the results we see that there is a good qualitative coincidence in features of emitted THz power and supercurrent in junction.

Tunnel junction multiple wavelength light-emitting diodes

DOEpatents

Olson, Jerry M.; Kurtz, Sarah R.

1992-01-01

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.

The influence of faults in basin-fill deposits on land subsidence, Las Vegas Valley, Nevada, USA

NASA Astrophysics Data System (ADS)

Burbey, Thomas

2002-07-01

The role of horizontal deformation caused by pumping of confined-aquifer systems is recognized as contributing to the development of earth fissures in semiarid regions, including Las Vegas Valley, Nevada. In spite of stabilizing water levels, new earth fissures continue to develop while existing ones continue to lengthen and widen near basin-fill faults. A three-dimensional granular displacement model based on Biot's consolidation theory (Biot, MA, 1941, General theory of three-dimensional consolidation. Jour. Applied Physics 12:155-164) has been used to evaluate the nature of displacement in the vicinity of two vertical faults. The fault was simulated as (1) a low-permeability barrier to horizontal flow, (2) a gap or structural break in the medium, but where groundwater flow is not obstructed, and (3) a combination of conditions (1) and (2). Results indicate that the low-permeability barrier greatly enhances horizontal displacement. The fault plane also represents a location of significant differential vertical subsidence. Large computed strains in the vicinity of the fault may suggest high potential for failure and the development of earth fissures when the fault is assumed to have low permeability. Results using a combination of the two boundaries suggest that potential fissure development may be great at or near the fault plane and that horizontal deformation is likely to play a key role in this development. Résumé. On considère que la déformation horizontale provoquée par un pompage dans un aquifère captif joue un rôle dans le développement des fissures du sol en régions semi-arides, comme la vallée de Las Vegas (Nevada). Malgré des niveaux d'eau stabilisés, de nouvelles fissures du sol continuent de se développer en longueur et en largeur au voisinage de failles dans les bassins sédimentaires. Un modèle de déplacement granulaire tri-dimensionnel, basé sur la théorie de la consolidation de Biot (Biot, M A, 1941, General theory of three-dimensional consolidation. Jour. Applied Physics 12:155-164), a été utilisé pour évaluer la nature du déplacement au voisinage de deux failles verticales. La faille a été simulée comme 1) une barrière de faible perméabilité pour l'écoulement horizontal, 2) une rupture structurale dans le milieu, mais sans obstruction de l'écoulement, et 3) une combinaison des deux précédentes conditions. Les résultats indiquent que la barrière de faible perméabilité favorise fortement le déplacement horizontal. Le plan de faille constitue aussi un lieu de subsidence différentielle verticale significative. Les fortes contraintes calculées au voisinage de la faille laissent penser qu'il existe un fort potentiel de rupture et le développement de fissures du sol quand on suppose que la faille possède une faible perméabilité. Les résultats utilisant une combinaison des deux conditions suggèrent que le développement potentiel de fissures peut être grand sur ou à proximité du plan de faille et que la déformation horizontale joue vraisemblablement un rôle clé dans ce développement. Resumen. Se conoce la contribución que la deformación horizontal causada por el bombeo de sistemas acuíferos confinados tienen en el desarrollo de fisuras en regiones semiáridas, como es el caso del Valle de Las Vegas (Nevada, Estados Unidos de América). A pesar de la estabilización de los niveles, se continúa desarrollando nuevas fisuras, mientras las ya existentes se alargan y ensanchan cerca de las fallas de relleno de cuenca. Se ha utilizado un modelo tridimensional de desplazamiento granular basado en la teoría de consolidación de Biot (Biot, M.A., 1941. General theory of three-dimensional consolidation. J. Applied Physics, 12: 155-164) para evaluar la naturaleza del desplazamiento junto a dos fallas verticales. Se ha simulado cada falla como (1) una barrera de baja permeabilidad al flujo horizontal, (2) un hueco o ruptura estructural en el medio pero sin obstrucción al flujo de aguas subterráneas, y (3) una combinación de las dos condiciones anteriores. Los resultados indican que la barrera de baja permeabilidad incrementa enormemente el desplazamiento horizontal. El plano de falla también representa una situación de subsidencia diferencial vertical significativa. Los valores elevados que se han calculado para la deformación en la proximidad de la falla pueden sugerir que existe un alto potencial de fallo y desarrollo de fisuras cuando se supone que la falla posee una baja permeabilidad. Si se combinan los dos contornos, los resultados sugieren que el desarrollo potencial de fisuras puede ser mayor en o cerca de el plano de falla, y que es probable que la deformación horizontal desempeñe un papel clave en él.

Specific Cx43 phosphorylation events regulate gap junction turnover in vivo

PubMed Central

Solan, Joell L.; Lampe, Paul D.

2014-01-01

Gap junctions, composed of proteins from the connexin gene family, are highly dynamic structures that are regulated by kinase-mediated signaling pathways and interactions with other proteins. Phosphorylation of Connexin43 (Cx43) at different sites controls gap junction assembly, gap junction size and gap junction turnover. Here we present a model describing how Akt, mitogen activated protein kinase (MAPK) and src kinase coordinate to regulate rapid turnover of gap junctions. Specifically, Akt phosphorylates Cx43 at S373 eliminating interaction with zona occludens-1 (ZO-1) allowing gap junctions to enlarge. Then MAPK and src phosphorylate Cx43 to initiate turnover. We integrate published data with new data to test and refine this model. Finally, we propose that differential coordination of kinase activation and Cx43 phosphorylation controls the specific routes of disassembly, e.g., annular junction formation or gap junctions can potentially “unzip” and be internalized/endocytosed into the cell that produced each connexin. PMID:24508467

Nanotube junctions

DOEpatents

Crespi, Vincent Henry; Cohen, Marvin Lou; Louie, Steven Gwon; Zettl, Alexander Karlwalte

2004-12-28

The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

Nanotube junctions

DOEpatents

Crespi, Vincent Henry; Cohen, Marvin Lou; Louie, Steven Gwon Sheng; Zettl, Alexander Karlwalter

2003-01-01

The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

Short Ballistic Josephson Coupling in Planar Graphene Junctions with Inhomogeneous Carrier Doping

NASA Astrophysics Data System (ADS)

Park, Jinho; Lee, Jae Hyeong; Lee, Gil-Ho; Takane, Yositake; Imura, Ken-Ichiro; Taniguchi, Takashi; Watanabe, Kenji; Lee, Hu-Jong

2018-02-01

We report on short ballistic (SB) Josephson coupling in junctions embedded in a planar heterostructure of graphene. Ballistic Josephson coupling is confirmed by the Fabry-Perot-type interference of the junction critical current Ic . The product of Ic and the normal-state junction resistance RN , normalized by the zero-temperature gap energy Δ0 of the superconducting electrodes, turns out to be exceptionally large close to 2, an indication of strong Josephson coupling in the SB junction limit. However, Ic shows a temperature dependence that is inconsistent with the conventional short-junction-like behavior based on the standard Kulik-Omel'yanchuk prediction. We argue that this feature stems from the effects of inhomogeneous carrier doping in graphene near the superconducting contacts, although the junction is in fact in the short-junction limit.

Correlation between the graft-host junction of penetrating keratoplasty by anterior segment-optical coherence tomography and the magnitude of postoperative astigmatism.

PubMed

Nassar, Ghada Azab; Arfeen, Shaimaa Abd El Salam

2017-07-01

This study aimed to evaluate the alignment pattern of the graft-host junction after penetrating keratoplasty (PK) by anterior segment-optical coherence tomography (AS-OCT) and to correlate this pattern with the magnitude of postoperative astigmatism. This retrospective observational study was carried out on forty patients who underwent PK from February 2013 to August 2014. AS-OCT was performed, and the graft-host junctions were classified into well-apposed junction, malapposed junction, and equally apposed junction. Mal-apposition is subdivided into gap and protrusion. The correlations between clinical characteristics, wound profiles from the AS-OCT, and the magnitude of postoperative astigmatism by Sirius camera (Costruzione Strumenti Oftalmici [CSO], Florence, Italy (CSO, Sirius), were analyzed. Graft-host junctions from forty patients were analyzed; 18 eyes had well-apposed junctions, ten eyes had malapposed junctions, and 12 had equally apposed junctions. The mean cylinder was -9.44 ± -4.00D in well-apposed group, -13.40 ± -5.01D in malapposed group, and -4.67 ± -0.94D in equally apposed group. Alignment pattern of the graft-host junction correlated significantly with the magnitude of astigmatism (P = 0.034). Preoperative corneal diseases did not have an effect on the magnitude of astigmatism (P = 0.123). The alignment pattern of the graft-host junction by AS-OCT can explain the postoperative astigmatism after PK where it correlates significantly with the magnitude of astigmatism.

Membrane junctions in Xenopus eggs: their distribution suggests a role in calcium regulation.

PubMed

Gardiner, D M; Grey, R D

1983-04-01

We have observed the presence of membrane junctions formed between the plasma membrane and cortical endoplasmic reticulum of mature, unactivated eggs of xenopus laevis. The parallel, paired membranes of the junction are separated by a 10-mn gap within which electron-dense material is present. This material occurs in patches with an average center-to-center distance of approximately 30 nm. These junctions are rare in immature (but fully grown) oocytes (approximately 2 percent of the plasma membrane is associated with junctions) and increase dramatically during progesterone-induced maturation. Junctions in the mature, unactivated egg are two to three times more abundant in the animal hemisphere (25-30 percent of the plasma membrane associated with junction) as compared with the vegetal hemisphere (10-15 percent). Junction density decreases rapidly to values characteristic of immature oocytes in response to egg activation. The plasma membrane-ER junctions of xenopus eggs are strikingly similar in structure to membrane junctions in muscle cells thought to be essential in the triggering of intracellular calcium release from the sarcoplasmic reticulum. In addition, the junctions' distinctive, animal-vegetal polarity of distribution, their dramatic appearance during maturation, and their disapperance during activation are correlated with previously documented patterns of calcium-mediated events in anuran eggs. We discuss several lines of evidence supporting the hypothesis that these junctions in xenopus eggs are sites that transduce extracellular events into intracellular calcium release during fertilization and activation of development.

Ballistic Graphene Josephson Junctions from the Short to the Long Junction Regimes.

PubMed

Borzenets, I V; Amet, F; Ke, C T; Draelos, A W; Wei, M T; Seredinski, A; Watanabe, K; Taniguchi, T; Bomze, Y; Yamamoto, M; Tarucha, S; Finkelstein, G

2016-12-02

We investigate the critical current I_{C} of ballistic Josephson junctions made of encapsulated graphene-boron-nitride heterostructures. We observe a crossover from the short to the long junction regimes as the length of the device increases. In long ballistic junctions, I_{C} is found to scale as ∝exp(-k_{B}T/δE). The extracted energies δE are independent of the carrier density and proportional to the level spacing of the ballistic cavity. As T→0 the critical current of a long (or short) junction saturates at a level determined by the product of δE (or Δ) and the number of the junction's transversal modes.

Single P-N junction tandem photovoltaic device

DOEpatents

Walukiewicz, Wladyslaw [Kensington, CA; Ager, III, Joel W.; Yu, Kin Man [Lafayette, CA

2012-03-06

A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

Single P-N junction tandem photovoltaic device

DOEpatents

Walukiewicz, Wladyslaw [Kensington, CA; Ager, III, Joel W.; Yu, Kin Man [Lafayette, CA

2011-10-18

A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

Knowledge and Teaching

ERIC Educational Resources Information Center

Rata, Elizabeth

2017-01-01

The paper addresses a major fissure in the sociology of knowledge with respect to the theories of knowledge which inform teaching and learning. Instructional teaching, or "teaching knowledge to the child", is compared to facilitation teaching, the "teaching the child" approach to show the extent to which their differences are…

Variation in bark characters and wood specific gravity of sugar maple

Treesearch

Robert L. Sajdak

1968-01-01

The external appearance of the bark of sugar maple (Acer saccharum Marsh.) has been described as "deeply furrowed," "fissured with long irregular thick plates or ridges," "somewhat scaly," "sometimes curling," and "highly variable." Adjacent trees in natural stands often have strikingly different...

Homologies of the meningeal-orbital arteries of humans: a reappraisal.

PubMed Central

Diamond, M K

1991-01-01

Two arteries connect the anterior branch of the middle meningeal artery to the lacrimal artery. One vessel, the sphenoidal artery, passes through the superior orbital fissure. The other vessel, the meningolacrimal artery, passes through the cranio-orbital foramen. An analysis of data derived from embryology, comparative anatomy, and patterns of adult variation indicates that the meningolacrimal artery is homologous with the ramus superior of the stapedial artery, an embryologically and phylogenetically primitive vessel. The sphenoidal artery probably forms late in human ontogeny and represents an evolutionary novelty. Its distribution is probably restricted to hominoids and may be exclusive to humans and orangutans (Pongo pygmaeus). The sphenoidal artery is associated with three other derived features: the sphenoparietal sinus and sulcus and a laterally expanded superior orbital fissure. The high frequency of the sphenoidal artery in Homo and Pongo probably represents a case of parallelism. The earliest paleontological evidence of an enlarged sphenoidal artery in the Hominidae occurs in Indonesian Homo erectus (Sangiran VI). PMID:1810930

[Prediction of the efficiency of endoscopic lung volume reduction by valves in severe emphysema].

PubMed

Bocquillon, V; Briault, A; Reymond, E; Arbib, F; Jankowski, A; Ferretti, G; Pison, C

2016-11-01

In severe emphysema, endoscopic lung volume reduction with valves is an alternative to surgery with less morbidity and mortality. In 2015, selection of patients who will respond to this technique is based on emphysema heterogeneity, a complete fissure visible on the CT-scan and absence of collateral ventilation between lobes. Our case report highlights that individualized prediction is possible. A 58-year-old woman had severe, disabling pulmonary emphysema. A high resolution thoracic computed tomography scan showed that the emphysema was heterogeneous, predominantly in the upper lobes, integrity of the left greater fissure and no collateral ventilation with the left lower lobe. A valve was inserted in the left upper lobe bronchus. At one year, clinical and functional benefits were significant with complete atelectasis of the treated lobe. The success of endoscopic lung volume reduction with a valve can be predicted, an example of personalized medicine. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

High Resolution Chest Computerized Tomography in the Diagnosis of Ocular Sarcoidosis in a High TB Endemic Population.

PubMed

Babu, Kalpana; Shukla, Sai Bhakti; Philips, Mariamma

2017-04-01

To review the role of high resolution chest computed tomography (HRCT) in ocular sarcoidosis in a high TB endemic population. This was a retrospective study. Out of 140 cases, 54 had ocular sarcoidosis, while 86 cases had ocular tuberculosis. Abnormal HRCT findings was noted in 52 cases (96.3%) of ocular sarcoidosis compared with 55 cases (64.7%) of ocular tuberculosis (p = 0.001). Mediastinal lymphadenopathy was the most common finding in both groups (p = 0.544). Hilar lymphadenopathy and fissural nodules were significantly seen in ocular sarcoidosis (p = 0.001). Necrosis was seen in three cases of ocular sarcoidosis. In nearly half of the cases, it was not possible to differentiate between sarcoidosis and tuberculosis on HRCT. HRCT is a useful diagnostic tool in ocular sarcoidosis. Bilateral hilar lymphadenopathy and fissural nodules are significant findings in ocular sarcoidosis. A confident diagnosis of ocular sarcoidosis is made by the amalgamation of results of clinical, radiologic, and other laboratory investigations.

Analysis of Temporal-spatial Co-variation within Gene Expression Microarray Data in an Organogenesis Model

NASA Astrophysics Data System (ADS)

Ehler, Martin; Rajapakse, Vinodh; Zeeberg, Barry; Brooks, Brian; Brown, Jacob; Czaja, Wojciech; Bonner, Robert F.

The gene networks underlying closure of the optic fissure during vertebrate eye development are poorly understood. We used a novel clustering method based on Laplacian Eigenmaps, a nonlinear dimension reduction method, to analyze microarray data from laser capture microdissected (LCM) cells at the site and developmental stages (days 10.5 to 12.5) of optic fissure closure. Our new method provided greater biological specificity than classical clustering algorithms in terms of identifying more biological processes and functions related to eye development as defined by Gene Ontology at lower false discovery rates. This new methodology builds on the advantages of LCM to isolate pure phenotypic populations within complex tissues and allows improved ability to identify critical gene products expressed at lower copy number. The combination of LCM of embryonic organs, gene expression microarrays, and extracting spatial and temporal co-variations appear to be a powerful approach to understanding the gene regulatory networks that specify mammalian organogenesis.

Questioning hagfish affinities of the enigmatic Devonian vertebrate Palaeospondylus

NASA Astrophysics Data System (ADS)

Johanson, Zerina; Smith, Moya; Sanchez, Sophie; Senden, Tim; Trinajstic, Kate; Pfaff, Cathrin

2017-07-01

Palaeospondylus gunni Traquair, 1890 is an enigmatic Devonian vertebrate whose taxonomic affinities have been debated since it was first described. Most recently, Palaeospondylus has been identified as a stem-group hagfish (Myxinoidea). However, one character questioning this assignment is the presence of three semicircular canals in the otic region of the cartilaginous skull, a feature of jawed vertebrates. Additionally, new tomographic data reveal that the following characters of crown-group gnathostomes (chondrichthyans + osteichthyans) are present in Palaeospondylus: a longer telencephalic region of the braincase, separation of otic and occipital regions by the otico-occipital fissure, and vertebral centra. As well, a precerebral fontanelle and postorbital articulation of the palatoquadrate are characteristic of certain chondrichthyans. Similarities in the structure of the postorbital process to taxa such as Pucapampella, and possible presence of the ventral cranial fissure, both support a resolution of Pa. gunni as a stem chondrichthyan. The internally mineralized cartilaginous skeleton in Palaeospondylus may represent a stage in the loss of bone characteristic of the Chondrichthyes.

Timetable for oral prevention in childhood-a current opinion.

PubMed

Fleming, Paddy

2015-01-01

Dental caries in young children remains a public health problem particularly for children whose families are socioeconomically deprived. A child's first dental visit should be at approximately 12 months of age and this should facilitate the provision of anticipatory guidance concerning oral health and dental development to the child's parents/guardians. Compliance with dietary advice is of key importance and motivational interviewing shows promise in relation to parents adopting good oral health practices for their children. Twice daily toothbrushing using toothpaste that contains in the range of 1000- 1500ppmF is a most important preventive measure. It is important to use a minimal amount of toothpaste, insure that it is not swallowed, have parental or adult supervision during toothbrushing and avoid rinsing with water following brushing with toothpaste. The professional application of topical fluoride varnish twice yearly is a proven caries preventative measure. The application of pit and fissure sealants to teeth with deep pits and fissures is recommended.

Tunnel junction multiple wavelength light-emitting diodes

DOEpatents

Olson, J.M.; Kurtz, S.R.

1992-11-24

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect. 5 figs.

Supercurrent and multiple Andreev reflections in micrometer-long ballistic graphene Josephson junctions.

PubMed

Zhu, Mengjian; Ben Shalom, Moshe; Mishchsenko, Artem; Fal'ko, Vladimir; Novoselov, Kostya; Geim, Andre

2018-02-08

Ballistic Josephson junctions are predicted to support a number of exotic physics processess, providing an ideal system to inject the supercurrent in the quantum Hall regime. Herein, we demonstrate electrical transport measurements on ballistic superconductor-graphene-superconductor junctions by contacting graphene to niobium with a junction length up to 1.5 μm. Hexagonal boron nitride encapsulation and one-dimensional edge contacts guarantee high-quality graphene Josephson junctions with a mean free path of several micrometers and record-low contact resistance. Transports in normal states including the observation of Fabry-Pérot oscillations and Sharvin resistance conclusively witness the ballistic propagation in the junctions. The critical current density J C is over one order of magnitude larger than that of the previously reported junctions. Away from the charge neutrality point, the I C R N product (I C is the critical current and R N the normal state resistance of junction) is nearly a constant, independent of carrier density n, which agrees well with the theory for ballistic Josephson junctions. Multiple Andreev reflections up to the third order are observed for the first time by measuring the differential resistance in the micrometer-long ballistic graphene Josephson junctions.

Imaging snake orbits at graphene n -p junctions

NASA Astrophysics Data System (ADS)

Kolasiński, K.; Mreńca-Kolasińska, A.; Szafran, B.

2017-01-01

We consider conductance mapping of the snake orbits confined along the n -p junction defined in graphene by the electrostatic doping in the quantum Hall regime. We explain the periodicity of conductance oscillations at the magnetic field and the Fermi energy scales by the properties of the n -p junction as a conducting channel. We evaluate the conductance maps for a floating gate scanning the surface of the device. In the quantum Hall conditions the currents flow near the edges of the sample and along the n -p junction. The conductance mapping resolves only the n -p junction and not the edges. The conductance oscillations along the junction are found in the maps with periodicity related to the cyclotron orbits of the scattering current. Stronger probe potentials provide support to localized resonances at one of the sides of the junction with current loops that interfere with the n -p junction currents. The interference results in a series of narrow lines parallel to the junction with positions that strongly depend on the magnetic field through the Aharonov-Bohm effect. The consequences of a limited transparency of finite-width n -p junctions are also discussed.

Geodynamical simulation of the RRF triple junction

NASA Astrophysics Data System (ADS)

Wang, Z.; Wei, D.; Liu, M.; Shi, Y.; Wang, S.

2017-12-01

Triple junction is the point at which three plate boundaries meet. Three plates at the triple junction form a complex geological tectonics, which is a natural laboratory to study the interactions of plates. This work studies a special triple junction, the oceanic transform fault intersects the collinear ridges with different-spreading rates, which is free of influence of ridge-transform faults and nearby hotspots. First, we build 3-D numerical model of this triple junction used to calculate the stead-state velocity and temperature fields resulting from advective and conductive heat transfer. We discuss in detail the influence of the velocity and temperature fields of the triple junction from viscosity, spreading rate of the ridge. The two sides of the oceanic transform fault are different sensitivities to the two factors. And, the influence of the velocity mainly occurs within 200km of the triple junction. Then, we modify the model by adding a ridge-transform fault to above model and directly use the velocity structure of the Macquarie triple junction. The simulation results show that the temperature at both sides of the oceanic transform fault decreases gradually from the triple junction, but the temperature difference between the two sides is a constant about 200°. And, there is little effect of upwelling velocity away from the triple junction 100km. The model results are compared with observational data. The heat flux and thermal topography along the oceanic transform fault of this model are consistent with the observed data of the Macquarie triple junction. The earthquakes are strike slip distributed along the oceanic transform fault. Their depths are also consistent with the zone of maximum shear stress. This work can help us to understand the interactions of plates of triple junctions and help us with the foundation for the future study of triple junctions.

Disruption of gap junctions attenuates aminoglycoside-elicited renal tubular cell injury

PubMed Central

Yao, Jian; Huang, Tao; Fang, Xin; Chi, Yuan; Zhu, Ying; Wan, Yigang; Matsue, Hiroyuki; Kitamura, Masanori

2010-01-01

BACKGROUND AND PURPOSE Gap junctions play important roles in the regulation of cell phenotype and in determining cell survival after various insults. Here, we investigated the role of gap junctions in aminoglycoside-induced injury to renal tubular cells. EXPERIMENTAL APPROACH Two tubular epithelial cell lines NRK-E52 and LLC-PK1 were compared for gap junction protein expression and function by immunofluorescent staining, Western blot and dye transfer assay. Cell viability after exposure to aminoglycosides was evaluated by WST assay. Gap junctions were modulated by transfection of the gap junction protein, connexin 43 (Cx43), use of Cx43 siRNA and gap junction inhibitors. KEY RESULTS NRK-E52 cells expressed abundant Cx43 and were functionally coupled by gap junctional intercellular communication (GJIC). Exposure of NRK-E52 cells to aminoglycosides, G418 and hygromycin, increased Cx43 phosphorylation and GJIC. The aminoglycosides also decreased cell viability that was prevented by gap junction inhibitors and Cx43 siRNA. LLC-PK1 cells were gap junction-deficient and resistant to aminoglycoside-induced cytotoxicity. Over-expression of a wild-type Cx43 converted LLC-PK1 cells to a drug-sensitive phenotype. The gap junction inhibitor α-glycyrrhetinic acid (α-GA) activated Akt in NRK-E52 cells. Inhibition of the Akt pathway enhanced cell toxicity to G418 and abolished the protective effects of α-GA. In addition, gentamycin-elicited cytotoxicity in NRK-E52 cells was also significantly attenuated by α-GA. CONCLUSION AND IMPLICATIONS Gap junctions contributed to the cytotoxic effects of aminoglycosides. Modulation of gap junctions could be a promising approach for prevention and treatment of aminoglycoside-induced renal tubular cell injury. PMID:20649601

Expression pattern of adhesion molecules in junctional epithelium differs from that in other gingival epithelia.

PubMed

Hatakeyama, S; Yaegashi, T; Oikawa, Y; Fujiwara, H; Mikami, T; Takeda, Y; Satoh, M

2006-08-01

The gingival epithelium is the physiologically important interface between the bacterially colonized gingival sulcus and periodontal soft and mineralized connective tissues, requiring protection from exposure to bacteria and their products. However, of the three epithelia comprising the gingival epithelium, the junctional epithelium has much wider intercellular spaces than the sulcular epithelium and oral gingival epithelium. Hence, the aim of the present study was to characterize the cell adhesion structure in the junctional epithelium compared with the other two epithelia. Gingival epithelia excised at therapeutic flap surgery from patients with periodontitis were examined for expression of adhesion molecules by immunofluorescence. In the oral gingival epithelium and sulcular epithelium, but not in the junctional epithelium, desmoglein 1 and 2 in cell-cell contact sites were more abundant in the upper than the suprabasal layers. E-cadherin, the main transmembranous molecule of adherens junctions, was present in spinous layers of the oral gingival epithelium and sulcular epithelium, but was scarce in the junctional epithelium. In contrast, desmoglein 3 and P-cadherin were present in all layers of the junctional epithelium as well as the oral gingival epithelium and sulcular epithelium. Connexin 43 was clearly localized to spinous layers of the oral gingival epithelium, sulcular epithelium and parts of the junctional epithelium. Claudin-1 and occludin were expressed in the cell membranes of a few superficial layers of the oral gingival epithelium. These findings indicated that the junctional epithelium contains only a few desmosomes, composed of only desmoglein 3; adherens junctions are probably absent because of defective E-cadherin. Thus, the anchoring junctions connecting junctional epithelium cells are lax, causing widened intercellular spaces. In contrast, the oral gingival epithelium, which has a few tight junctions, functions as a barrier.

Endoplasmic reticulum-plasma membrane junctions: structure, function and dynamics.

PubMed

Okeke, Emmanuel; Dingsdale, Hayley; Parker, Tony; Voronina, Svetlana; Tepikin, Alexei V

2016-06-01

Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are contact sites between the ER and the PM; the distance between the two organelles in the junctions is below 40 nm and the membranes are connected by protein tethers. A number of molecular tools and technical approaches have been recently developed to visualise, modify and characterise properties of ER-PM junctions. The junctions serve as the platforms for lipid exchange between the organelles and for cell signalling, notably Ca(2+) and cAMP signalling. Vice versa, signalling events regulate the development and properties of the junctions. Two Ca(2+) -dependent mechanisms of de novo formation of ER-PM junctions have been recently described and characterised. The junction-forming proteins and lipids are currently the focus of vigorous investigation. Junctions can be relatively short-lived and simple structures, forming and dissolving on the time scale of a few minutes. However, complex, sophisticated and multifunctional ER-PM junctions, capable of attracting numerous protein residents and other cellular organelles, have been described in some cell types. The road from simplicity to complexity, i.e. the transformation from simple 'nascent' ER-PM junctions to advanced stable multiorganellar complexes, is likely to become an attractive research avenue for current and future junctologists. Another area of considerable research interest is the downstream cellular processes that can be activated by specific local signalling events in the ER-PM junctions. Studies of the cell physiology and indeed pathophysiology of ER-PM junctions have already produced some surprising discoveries, likely to expand with advances in our understanding of these remarkable organellar contact sites. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Ferromagnetic Josephson Junctions for Cryogenic Memory

NASA Astrophysics Data System (ADS)

Niedzielski, Bethany M.; Gingrich, Eric C.; Khasawneh, Mazin A.; Loloee, Reza; Pratt, William P., Jr.; Birge, Norman O.

2015-03-01

Josephson junctions containing ferromagnetic materials are of interest for both scientific and technological purposes. In principle, either the amplitude of the critical current or superconducting phase shift across the junction can be controlled by the relative magnetization directions of the ferromagnetic layers in the junction. Our approach concentrates on phase control utilizing two junctions in a SQUID geometry. We will report on efforts to control the phase of junctions carrying either spin-singlet or spin-triplet supercurrent for cryogenic memory applications. Supported by Northorp Grumman Corporation and by IARPA under SPAWAR Contract N66001-12-C-2017.

Calcium/Ask1/MKK7/JNK2/c-Src signalling cascade mediates disruption of intestinal epithelial tight junctions by dextran sulfate sodium.

PubMed

Samak, Geetha; Chaudhry, Kamaljit K; Gangwar, Ruchika; Narayanan, Damodaran; Jaggar, Jonathan H; Rao, RadhaKrishna

2015-02-01

Disruption of intestinal epithelial tight junctions is an important event in the pathogenesis of ulcerative colitis. Dextran sodium sulfate (DSS) induces colitis in mice with symptoms similar to ulcerative colitis. However, the mechanism of DSS-induced colitis is unknown. We investigated the mechanism of DSS-induced disruption of intestinal epithelial tight junctions and barrier dysfunction in Caco-2 cell monolayers in vitro and mouse colon in vivo. DSS treatment resulted in disruption of tight junctions, adherens junctions and actin cytoskeleton leading to barrier dysfunction in Caco-2 cell monolayers. DSS induced a rapid activation of c-Jun N-terminal kinase (JNK), and the inhibition or knockdown of JNK2 attenuated DSS-induced tight junction disruption and barrier dysfunction. In mice, DSS administration for 4 days caused redistribution of tight junction and adherens junction proteins from the epithelial junctions, which was blocked by JNK inhibitor. In Caco-2 cell monolayers, DSS increased intracellular Ca(2+) concentration, and depletion of intracellular Ca(2+) by 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester) (BAPTA/AM) or thapsigargin attenuated DSS-induced JNK activation, tight junction disruption and barrier dysfunction. Knockdown of apoptosis signal-regulated kinase 1 (Ask1) or MKK7 blocked DSS-induced tight junction disruption and barrier dysfunction. DSS activated c-Src by a Ca2+ and JNK-dependent mechanism. Inhibition of Src kinase activity or knockdown of c-Src blocked DSS-induced tight junction disruption and barrier dysfunction. DSS increased tyrosine phosphorylation of occludin, zonula occludens-1 (ZO-1), E-cadherin and β-catenin. SP600125 abrogated DSS-induced tyrosine phosphorylation of junctional proteins. Recombinant JNK2 induced threonine phosphorylation and auto-phosphorylation of c-Src. The present study demonstrates that Ca(2+)/Ask1/MKK7/JNK2/cSrc signalling cascade mediates DSS-induced tight junction disruption and barrier dysfunction.

Fluorescence recovery after photobleaching reveals regulation and distribution of connexin36 gap junction coupling within mouse islets of Langerhans

PubMed Central

Farnsworth, Nikki L; Hemmati, Alireza; Pozzoli, Marina; Benninger, Richard K P

2014-01-01

The pancreatic islets are central to the maintenance of glucose homeostasis through insulin secretion. Glucose-stimulated insulin secretion is tightly linked to electrical activity in β cells within the islet. Gap junctions, composed of connexin36 (Cx36), form intercellular channels between β cells, synchronizing electrical activity and insulin secretion. Loss of gap junction coupling leads to altered insulin secretion dynamics and disrupted glucose homeostasis. Gap junction coupling is known to be disrupted in mouse models of pre-diabetes. Although approaches to measure gap junction coupling have been devised, they either lack cell specificity, suitable quantification of coupling or spatial resolution, or are invasive. The purpose of this study was to develop fluorescence recovery after photobleaching (FRAP) as a technique to accurately and robustly measure gap junction coupling in the islet. The cationic dye Rhodamine 123 was used with FRAP to quantify dye diffusion between islet β cells as a measure of Cx36 gap junction coupling. Measurements in islets with reduced Cx36 verified the accuracy of this technique in distinguishing between distinct levels of gap junction coupling. Analysis of individual cells revealed that the distribution of coupling across the islet is highly heterogeneous. Analysis of several modulators of gap junction coupling revealed glucose- and cAMP-dependent modulation of gap junction coupling in islets. Finally, FRAP was used to determine cell population specific coupling, where no functional gap junction coupling was observed between α cells and β cells in the islet. The results of this study show FRAP to be a robust technique which provides the cellular resolution to quantify the distribution and regulation of Cx36 gap junction coupling in specific cell populations within the islet. Future studies utilizing this technique may elucidate the role of gap junction coupling in the progression of diabetes and identify mechanisms of gap junction regulation for potential therapies. PMID:25172942

Fluorescence recovery after photobleaching reveals regulation and distribution of connexin36 gap junction coupling within mouse islets of Langerhans.

PubMed

Farnsworth, Nikki L; Hemmati, Alireza; Pozzoli, Marina; Benninger, Richard K P

2014-10-15

The pancreatic islets are central to the maintenance of glucose homeostasis through insulin secretion. Glucose‐stimulated insulin secretion is tightly linked to electrical activity in β cells within the islet. Gap junctions, composed of connexin36 (Cx36), form intercellular channels between β cells, synchronizing electrical activity and insulin secretion. Loss of gap junction coupling leads to altered insulin secretion dynamics and disrupted glucose homeostasis. Gap junction coupling is known to be disrupted in mouse models of pre‐diabetes. Although approaches to measure gap junction coupling have been devised, they either lack cell specificity, suitable quantification of coupling or spatial resolution, or are invasive. The purpose of this study was to develop fluorescence recovery after photobleaching (FRAP) as a technique to accurately and robustly measure gap junction coupling in the islet. The cationic dye Rhodamine 123 was used with FRAP to quantify dye diffusion between islet β cells as a measure of Cx36 gap junction coupling. Measurements in islets with reduced Cx36 verified the accuracy of this technique in distinguishing between distinct levels of gap junction coupling. Analysis of individual cells revealed that the distribution of coupling across the islet is highly heterogeneous. Analysis of several modulators of gap junction coupling revealed glucose‐ and cAMP‐dependent modulation of gap junction coupling in islets. Finally, FRAP was used to determine cell population specific coupling, where no functional gap junction coupling was observed between α cells and β cells in the islet. The results of this study show FRAP to be a robust technique which provides the cellular resolution to quantify the distribution and regulation of Cx36 gap junction coupling in specific cell populations within the islet. Future studies utilizing this technique may elucidate the role of gap junction coupling in the progression of diabetes and identify mechanisms of gap junction regulation for potential therapies.

Calcium Channels and Oxidative Stress Mediate a Synergistic Disruption of Tight Junctions by Ethanol and Acetaldehyde in Caco-2 Cell Monolayers.

PubMed

Samak, Geetha; Gangwar, Ruchika; Meena, Avtar S; Rao, Roshan G; Shukla, Pradeep K; Manda, Bhargavi; Narayanan, Damodaran; Jaggar, Jonathan H; Rao, RadhaKrishna

2016-12-13

Ethanol is metabolized into acetaldehyde in most tissues. In this study, we investigated the synergistic effect of ethanol and acetaldehyde on the tight junction integrity in Caco-2 cell monolayers. Expression of alcohol dehydrogenase sensitized Caco-2 cells to ethanol-induced tight junction disruption and barrier dysfunction, whereas aldehyde dehydrogenase attenuated acetaldehyde-induced tight junction disruption. Ethanol up to 150 mM did not affect tight junction integrity or barrier function, but it dose-dependently increased acetaldehyde-mediated tight junction disruption and barrier dysfunction. Src kinase and MLCK inhibitors blocked this synergistic effect of ethanol and acetaldehyde on tight junction. Ethanol and acetaldehyde caused a rapid and synergistic elevation of intracellular calcium. Calcium depletion by BAPTA or Ca 2+ -free medium blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. Diltiazem and selective knockdown of TRPV6 or Ca V 1.3 channels, by shRNA blocked ethanol and acetaldehyde-induced tight junction disruption and barrier dysfunction. Ethanol and acetaldehyde induced a rapid and synergistic increase in reactive oxygen species by a calcium-dependent mechanism. N-acetyl-L-cysteine and cyclosporine A, blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. These results demonstrate that ethanol and acetaldehyde synergistically disrupt tight junctions by a mechanism involving calcium, oxidative stress, Src kinase and MLCK.

Assembly of the Escherichia coli RuvABC resolvasome directs the orientation of Holliday junction resolution

PubMed Central

van Gool, Alain J.; Hajibagheri, Nasser M.A.; Stasiak, Andrzej; West, Stephen C.

1999-01-01

Genetic recombination can lead to the formation of intermediates in which DNA molecules are linked by Holliday junctions. Movement of a junction along DNA, by a process known as branch migration, leads to heteroduplex formation, whereas resolution of a junction completes the recombination process. Holliday junctions can be resolved in either of two ways, yielding products in which there has, or has not, been an exchange of flanking markers. The ratio of these products is thought to be determined by the frequency with which the two isomeric forms (conformers) of the Holliday junction are cleaved. Recent studies with enzymes that process Holliday junctions in Escherichia coli, the RuvABC proteins, however, indicate that protein binding causes the junction to adopt an open square-planar configuration. Within such a structure, DNA isomerization can have little role in determining the orientation of resolution. To determine the role that junction-specific protein assembly has in determining resolution bias, a defined in vitro system was developed in which we were able to direct the assembly of the RuvABC resolvasome. We found that the bias toward resolution in one orientation or the other was determined simply by the way in which the Ruv proteins were positioned on the junction. Additionally, we provide evidence that supports current models on RuvABC action in which Holliday junction resolution occurs as the resolvasome promotes branch migration. PMID:10421637

Models and methods for in vitro testing of hepatic gap junctional communication.

PubMed

Maes, Michaël; Yanguas, Sara Crespo; Willebrords, Joost; Vinken, Mathieu

2015-12-25

Inherent to their pivotal roles in controlling all aspects of the liver cell life cycle, hepatocellular gap junctions are frequently disrupted upon impairment of the homeostatic balance, as occurs during liver toxicity. Hepatic gap junctions, which are mainly built up by connexin32, are specifically targeted by tumor promoters and epigenetic carcinogens. This renders inhibition of gap junction functionality a suitable indicator for the in vitro detection of nongenotoxic hepatocarcinogenicity. The establishment of a reliable liver gap junction inhibition assay for routine in vitro testing purposes requires a cellular system in which gap junctions are expressed at an in vivo-like level as well as an appropriate technique to probe gap junction activity. Both these models and methods are discussed in the current paper, thereby focusing on connexin32-based gap junctions. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of inductive and capacitive coupling on the current–voltage characteristic and electromagnetic radiation from a system of Josephson junctions

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

Rahmonov, I. R., E-mail: rahmonov@theor.jinr.ru, E-mail: ilhom-tj@inbox.ru; Shukrinov, Yu. M.; Atanasova, P. Kh.

We have studied the current–voltage characteristic of a system of long Josephson junctions taking into account the inductive and capacitive coupling. The dependence of the average time derivative of the phase difference on the bias current and spatiotemporal dependences of the phase difference and magnetic field in each junction are considered. The possibility of branching of the current–voltage characteristic in the region of zero field step, which is associated with different numbers of fluxons in individual Josephson junctions, is demonstrated. The current–voltage characteristic of the system of Josephson junctions is compared with the case of a single junction, and itmore » is shown that the observed branching is due to coupling between the junctions. The intensity of electromagnetic radiation associated with motion of fluxons is calculated, and the effect of coupling between junctions on the radiation power is analyzed.« less

Varactor with integrated micro-discharge source

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

Elizondo-Decanini, Juan M.; Manginell, Ronald P.; Moorman, Matthew W.

2016-10-18

An apparatus that includes a varactor element and an integrated micro-discharge source is disclosed herein. In a general embodiment, the apparatus includes at least one np junction and at least one voltage source that is configured to apply voltage across the np junction. The apparatus further includes an aperture that extends through the np junction. When the voltage is applied across the np junction, gas in the aperture is ionized, forming a plasma, in turn causing a micro-discharge (of light, charge particles, and space charge) to occur. The light (charge particles, and space charge) impinges upon the surface of themore » np junction exposed in the aperture, thereby altering capacitance of the np junction. When used within an oscillator circuit, the effect of the plasma on the np-junction extends the capacitance changes of the np-junction and extends the oscillator frequency range in ways not possible by a conventional voltage controlled oscillator (VCO).« less

Extension of the ADC Charge-Collection Model to Include Multiple Junctions

NASA Technical Reports Server (NTRS)

Edmonds, Larry D.

2011-01-01

The ADC model is a charge-collection model derived for simple p-n junction silicon diodes having a single reverse-biased p-n junction at one end and an ideal substrate contact at the other end. The present paper extends the model to include multiple junctions, and the goal is to estimate how collected charge is shared by the different junctions.

Cell-specific expression of connexins and evidence of restricted gap junctional coupling between glial cells and between neurons.

PubMed

Rash, J E; Yasumura, T; Dudek, F E; Nagy, J I

2001-03-15

The transmembrane connexin proteins of gap junctions link extracellularly to form channels for cell-to-cell exchange of ions and small molecules. Two primary hypotheses of gap junction coupling in the CNS are the following: (1) generalized coupling occurs between neurons and glia, with some connexins expressed in both neurons and glia, and (2) intercellular junctional coupling is restricted to specific coupling partners, with different connexins expressed in each cell type. There is consensus that gap junctions link neurons to neurons and astrocytes to oligodendrocytes, ependymocytes, and other astrocytes. However, unresolved are the existence and degree to which gap junctions occur between oligodendrocytes, between oligodendrocytes and neurons, and between astrocytes and neurons. Using light microscopic immunocytochemistry and freeze-fracture replica immunogold labeling of adult rat CNS, we investigated whether four of the best-characterized CNS connexins are each present in one or more cell types, whether oligodendrocytes also share gap junctions with other oligodendrocytes or with neurons, and whether astrocytes share gap junctions with neurons. Connexin32 (Cx32) was found only in gap junctions of oligodendrocyte plasma membranes, Cx30 and Cx43 were found only in astrocyte membranes, and Cx36 was only in neurons. Oligodendrocytes shared intercellular gap junctions only with astrocytes, with each oligodendrocyte isolated from other oligodendrocytes except via astrocyte intermediaries. Finally, neurons shared gap junctions only with other neurons and not with glial cells. Thus, the different cell types of the CNS express different connexins, which define separate pathways for neuronal versus glial gap junctional communication.

Regulation of Gap Junction Dynamics by UNC-44/ankyrin and UNC-33/CRMP through VAB-8 in C. elegans Neurons

PubMed Central

Yan, Dong

2016-01-01

Gap junctions are present in both vertebrates and invertebrates from nematodes to mammals. Although the importance of gap junctions has been documented in many biological processes, the molecular mechanisms underlying gap junction dynamics remain unclear. Here, using the C. elegans PLM neurons as a model, we show that UNC-44/ankyrin acts upstream of UNC-33/CRMP in regulation of a potential kinesin VAB-8 to control gap junction dynamics, and loss-of-function in the UNC-44/UNC-33/VAB-8 pathway suppresses the turnover of gap junction channels. Therefore, we first show a signal pathway including ankyrin, CRMP, and kinesin in regulating gap junctions. PMID:27015090

Many-junction photovoltaic device performance under non-uniform high-concentration illumination

NASA Astrophysics Data System (ADS)

Valdivia, Christopher E.; Wilkins, Matthew M.; Chahal, Sanmeet S.; Proulx, Francine; Provost, Philippe-Olivier; Masson, Denis P.; Fafard, Simon; Hinzer, Karin

2017-09-01

A parameterized 3D distributed circuit model was developed to calculate the performance of III-V solar cells and photonic power converters (PPC) with a variable number of epitaxial vertically-stacked pn junctions. PPC devices are designed with many pn junctions to realize higher voltages and to operate under non-uniform illumination profiles from a laser or LED. Performance impacts of non-uniform illumination were greatly reduced with increasing number of junctions, with simulations comparing PPC devices with 3 to 20 junctions. Experimental results using Azastra Opto's 12- and 20-junction PPC illuminated by an 845 nm diode laser show high performance even with a small gap between the PPC and optical fiber output, until the local tunnel junction limit is reached.

Mechanically Stacked Dual-Junction and Triple-Junction III-V/Si-IBC Cells with Efficiencies Exceeding 31.5% and 35.4%: Preprint

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

Schnabel, Manuel; Tamboli, Adele C; Warren, Emily L

Despite steady advancements in the efficiency of crystalline Silicon (c-Si) photovoltaics (PV) within the last decades, the theoretical efficiency limit of 29.4 percent depicts an insurmountable barrier for silicon-based single-junction solar cells. Combining the Si cell with a second absorber material on top in a dual junction tandem or triple junction solar cell is an attractive option to surpass this limit significantly. We demonstrate a mechanically stacked GaInP/Si dual-junction cell with an in-house measured efficiency of 31.5 percent and a GaInP/GaAs/Si triple-junction cell with a certified efficiency of 35.4 percent.

Controlling formation of single-molecule junctions by electrochemical reduction of diazonium terminal groups.

PubMed

Hines, Thomas; Díez-Pérez, Ismael; Nakamura, Hisao; Shimazaki, Tomomi; Asai, Yoshihiro; Tao, Nongjian

2013-03-06

We report controlling the formation of single-molecule junctions by means of electrochemically reducing two axialdiazonium terminal groups on a molecule, thereby producing direct Au-C covalent bonds in situ between the molecule and gold electrodes. We report a yield enhancement in molecular junction formation as the electrochemical potential of both junction electrodes approach the reduction potential of the diazonium terminal groups. Step length analysis shows that the molecular junction is significantly more stable, and can be pulled over a longer distance than a comparable junction created with amine anchoring bonds. The stability of the junction is explained by the calculated lower binding energy associated with the direct Au-C bond compared with the Au-N bond.

MLN0264 in Previously Treated Asian Participants With Advanced Gastrointestinal Carcinoma or Metastatic or Recurrent Gastric or Gastroesophageal Junction Adenocarcinoma Expressing Guanylyl Cyclase C

ClinicalTrials.gov

2017-02-08

Advanced Gastrointestinal Carcinoma; Gastroesophageal Junction Adenocarcinoma; Recurrent Gastric Adenocarcinoma; Recurrent Gastroesophageal Junction Adenocarcinoma; Metastatic Gastric Adenocarcinoma; Metastatic Gastroesophageal Junction Adenocarcinoma; Recurrent Gastrointestinal Carcinoma

Performance comparison between p–i–n and p–n junction tunneling field-effect transistors

NASA Astrophysics Data System (ADS)

Yoon, Young Jun; Seo, Jae Hwa; Kang, In Man

2018-06-01

In this study, we investigated the direct-current (DC) and radio-frequency (RF) performances of p–i–n and p–n junction tunneling field-effect transistors (TFETs). Compared to the p–i–n junction TFET, the p–n junction TFET exhibited higher on-state current (I on) because the channel formation mechanism of the p–n junction TFET resulted in a narrower tunneling barrier and an expanded tunneling area. Further, the reduction of I on of the p–n junction TFET by the interface trap was smaller. Moreover, the p–n junction TFET exhibited lower gate-to-drain capacitance (C gd) because a depletion capacitance (C gd,dep) was formed by the depletion region under gate dielectric. Consequently, the p–n junction TFET achieved an improvement of cut-off frequency (f T) and intrinsic delay time (τ), which are related to the current performance and total gate capacitance (C gg). We confirmed the enhancement of device performances in terms of I on, f T, and τ by the conduction mechanism of the p–n junction TFET.

Tight junctions negatively regulate mechanical forces applied to adherens junctions in vertebrate epithelial tissue.

PubMed

Hatte, Guillaume; Prigent, Claude; Tassan, Jean-Pierre

2018-02-05

Epithelia are layers of polarised cells tightly bound to each other by adhesive contacts. Epithelia act as barriers between an organism and its external environment. Understanding how epithelia maintain their essential integrity while remaining sufficiently plastic to allow events such as cytokinesis to take place is a key biological problem. In vertebrates, the remodelling and reinforcement of adherens junctions maintains epithelial integrity during cytokinesis. The involvement of tight junctions in cell division, however, has remained unexplored. Here, we examine the role of tight junctions during cytokinesis in the epithelium of the Xenopus laevis embryo. Depletion of the tight junction-associated proteins ZO-1 and GEF-H1 leads to altered cytokinesis duration and contractile ring geometry. Using a tension biosensor, we show that cytokinesis defects originate from misregulation of tensile forces applied to adherens junctions. Our results reveal that tight junctions regulate mechanical tension applied to adherens junctions, which in turn impacts cytokinesis.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

Gap junction-mediated intercellular communication in the immune system.

PubMed

Neijssen, Joost; Pang, Baoxu; Neefjes, Jacques

2007-01-01

Immune cells are usually considered non-attached blood cells, which would exclude the formation of gap junctions. This is a misconception since many immune cells express connexin 43 (Cx43) and other connexins and are often residing in tissue. The role of gap junctions is largely ignored by immunologists as is the immune system in the field of gap junction research. Here, the current knowledge of the distribution of connexins and the function of gap junctions in the immune system is discussed. Gap junctions appear to play many roles in antibody productions and specific immune responses and may be important in sensing danger in tissue by the immune system. Gap junctions not only transfer electrical and metabolical but also immunological information in the form of peptides for a process called cross-presentation. This is essential for proper immune responses to viruses and possibly tumours. Until now only 40 research papers on gap junctions in the immune system appeared and this will almost certainly expand with the increased mutual interest between the fields of immunology and gap junction research.

Development of molecular tools for use in beech bark disease management

Treesearch

Jennifer L. Koch; David W. Carey; Mary E. Mason; C. Dana Nelson; Abdelali Barakat; John E. Carlson; David Neale

2011-01-01

Beech bark disease (BBD) has been killing American beech trees in eastern North America since the late 1890s. The disease is initiated by feeding of the beech scale insect, Cryptococcus fagisuga, which leads to the development of small fissures in the bark.

Accounting for Teacher Knowledge: Reterritorializations as Epistemic Suicide

ERIC Educational Resources Information Center

Webb, P. Taylor

2007-01-01

Educators are experiencing a knowledge crisis and, as a result, they are committing epistemological suicide. The crisis is born out of two different conceptions of teacher knowledge, each containing a limitation that generates fissures within the respective knowledge paradigm. Educators commit epistemic suicide when surveillance technologies,…

Comparison of Periorbital Anthropometry Between Beauty Pageant Contestants and Ordinary Young Women with Korean Ethnicity: A Three-Dimensional Photogrammetric Analysis.

PubMed

Kim, Young Chul; Kwon, Jin Geun; Kim, Sung Chan; Huh, Chang Hun; Kim, Hee Jin; Oh, Tae Suk; Koh, Kyung S; Choi, Jong Woo; Jeong, Woo Shik

2018-04-01

The purpose of this study is to investigate the differences in the periorbital anthropometry between national Beauty Pageant Contestants and Ordinary Young Women with Korean ethnicity. Forty-three Beauty Pageant Contestants who were elected for the national beauty contest and forty-eight Ordinary Young Women underwent 3D photography. The authors analyzed 3D photogrammetric measures regarding periorbital soft tissue. The palpebral fissure width was significantly higher in the Beauty Pageant Contestants than the Ordinary Young Women (27.7 ± 1.2 vs. 26.3 ± 1.6 mm) (p < 0.001). The palpebral fissure height was also significantly higher in the Beauty Pageant Contestants (11.5. ± 1.0 vs. 9.1 ± 1.2 mm) (p < 0.001). The intercanthal width and upper eyelid height were smaller for the Beauty Pageant Contestants (intercanthal width, 34.3 ± 1.86 mm vs. 36.7 ± 3.1 mm; upper eyelid height, 11.5 ± 1.4 mm vs. 13.4 ± 2.3 mm) (p < 0.05). The nasal width and midfacial width were significantly smaller in the Beauty Pageant Contestants (nasal width, 38.0 ± 1.8 vs. 39.5 ± 2.2 mm; midfacial width 144.5 ± 3.9 vs. 146.9 ± 5.2 mm) (p < 0.05). The eyebrow showed significantly different features between the two groups in terms of vertical position in the upper face and the shape of the brow apex. The interpupillary distance, binocular distance, slant of palpebral fissure and width of pretarsal crease showed no significant difference between the two groups. Periorbital features in Beauty Pageant Contestants are wide-set eyes, larger palpebral fissure in width and height, relatively small upper eyelid height and intercanthal width, and relatively small nose and facial width compared to normal women. Our anthropometric results can be referable values for Asian eyelid surgery and help surgeons to establish individualized surgical planning. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Basaltic ring structures of the Serra Geral Formation at the southern Triângulo Mineiro, Água Vermelha region, Brazil

NASA Astrophysics Data System (ADS)

Pacheco, Fernando Estevão Rodrigues Crincoli; Caxito, Fabricio de Andrade; Moraes, Lucia Castanheira de; Marangoni, Yara Regina; Santos, Roberto Paulo Zanon dos; Pedrosa-Soares, Antonio Carlos

2018-04-01

The Serra Geral Formation constitutes a continental magmatic province on the southern part of South America within the Paraná basin. Basaltic magmatism of the Serra Geral Formation occurred as extrusions at around 134.5 to 131.5 My ago. The formation is part of the Paraná-Etendeka large igneous province, spanning South America and southwestern Africa. The main extrusion mechanism was probably through fissures related to extensional regime during the breakup of Gondwana in the Cretaceous. Basaltic ring structures (BRS) with tens of meters of diameter, cropping out downstream of Grande river at Água Vermelha hydroelectric dam in southern Triângulo Mineiro region, enable the study of the mechanism of extrusion. The origin of the BRS has been subject to differing interpretations in the past, either collapsed lava flows or central conduits. Detailed geological mapping at 1:1000 scale, stratigraphic, petrographic and gravimetric analysis of the most well preserved of the BRS, with a 200 m diameter, has enabled the description of thirteen different basalt lava flows, along with single a central lava lake and a ring dyke structure. The central flow, interpreted as a preserved lava lake, comprises vesicle- and amygdale-rich basalt, spatter, ropy and degassing structures. The most basal of the thirteen lava flows has massive basalt containing geodes filled with quartz. Above, the lava flows show massive basalt with vertical columnar jointing where is possible to identify the top and bottom of each individual flow, with gentle dips towards the perimeter of the structure. A prominent ring dyke dipping towards the lava lake presents horizontal columnar jointing and cuts the basal and central flows. The gravimetric analysis shows a weak negative Bouguer anomaly on the center of the BRS. The proposed model describes the volcanism of the region in three main steps: (1) fissure flow occurs with lava input; (2) this lava cools and crystallizes cementing most of the fissures, promoting the formation of localized central conduits; and (3) the presence of dissolved gas in lava produces ring and radial fractures around the solidified lava lake. The magma uses some of the ring fissures to ascend and the following lava flows assume the ring shape of the dyke vent. Thus, the BRS in Água Vermelha region can be interpreted as remnants of central conduits representing the late stage magmatism of the Serra Geral Formation.

Contact hypersensitivity in hand dermatitis.

PubMed

Li, Lin-feng; Wang, Jing

2002-10-01

Contact hypersensitivity (CHS) in hand dermatitis (HD) was studied by patch testing (PT) 105 consecutive adult HD patients and 361 cases of suspected non-hand allergic contact dermatitis (NHD). The suspected offending agents were also investigated by a questionnaire. Age and sex distribution was no different between the 2 groups. The total positivity rate of PT in the HD group was much lower than in the control group (46.7% versus 63.2%, p < 0.01, chi2-test). The most common allergens in HD were rubber mix(17.1%), p-phenylenediamine (PPD) (14.3%), fragrance mix (9.5%), nickel (9.5%), colophonium (6.7%) and potassium dichromate (2.9%), while those in the control group, in sequence, were nickel (20.5%), rubber mix (16.9%), PPD (14.1%), fragrance mix (12.7%), potassium dichromate (5.5%) and colophonium (5.0%). The positivity rate to nickel was lower in the HD group (9.5% versus 20.5%, p < 0.05, chi2-test), while there was no significant difference for the other allergens. HD was divided arbitrarily into 5 groups: (1) vesicular form, in which fine papules and vesicles can be detected. 65.7% of the HD was vesicular form and 55.1% of them were PT positive; (2) fissured form, in which dry skin with fine fissures or desquamation is seen. 8.6% of the HD was fissured form and 30% of them were PT positive; (3) hyperkeratotic form, in which the lesions are thick, hyperkeratotic plaques - 6.7% of the HD was this form and no positive reaction was found; (4) hand and foot dermatitis (HFD) - 12.4% of HD was HFD and 53.8% of them were PT positive; (5) pompholyx - 6.7% of the patients had pompholyx and one positive result to nickel was detected. The suspected offending agents were reported in only 13 (12.4%) patients. These results suggest that CHS is less common in HD than in NHD and that other factors, such as skin irritation, may play more of a role in HD. Nickel allergy is less common in HD than in NHD. CHS may play a role in more than 1/2 of vesicular form HD, HFD and in some fissured HD also, but is less common in hyperkeratotic HD and pompholyx. Only a small proportion of the HD patients could report the suspected offending agents and PT should be performed in all patients with chronic HD.

Intergranular corrosion in AA5XXX aluminum alloys with discontinuous precipitation at the grain boundaries

NASA Astrophysics Data System (ADS)

Bumiller, Elissa

The US Navy currently uses AA5xxx aluminum alloys for structures exposed to a marine environment. These alloys demonstrate excellent corrosion resistance over other aluminum alloys (e.g., AA2xxx or AA7xxx) in this environment, filling a niche in the marine structures market when requiring a light-weight alternative to steel. However, these alloys are susceptible to localized corrosion; more specifically, intergranular corrosion (IGC) is of concern. IGC of AA5xxx alloys due to the precipitation of beta phase on the grain boundaries is a well-established phenomenon referred to as sensitization. At high degrees of sensitization, the IGC path is a continuous anodic path of beta phase particles. At lower degrees of sensitization, the beta phase coverage at the grain boundaries is not continuous. The traditional ranges of susceptibility to IGC as defined by ASTM B928 are in question due to recent studies. These studies showed that even at mid range degrees of sensitization where the beta phase is no longer continuous, IGC may still occur. Previous thoughts on IGC of these alloy systems were founded on the idea that once the grain boundary precipitate became discontinuous the susceptibility to IGC was greatly reduced. Additionally, IGC susceptibility has been defined metallurgically by compositional gradients at the grain boundaries. However, AA5xxx alloys show no compositional gradients at the grain boundaries, yet are still susceptible to IGC. The goal of this work is to establish criteria necessary for IGC to occur given no continuous beta phase path and no compositional gradient at the grain boundaries. IGC performance of the bulk alloy system AA5083 has been studied along with the primary phases present in the IGC system: alpha and beta phases using electrochemistry and modeling as the primary tools. Numerical modeling supports that at steady-state the fissure tip is likely saturated with Mg in excess of the 4% dissolved in the matrix. By combining these results, quantitative insights into the IGC susceptibility of AA5xxx alloys is gained. As the aspect ratio increases, the concentration of metal ions in the fissure solution increases, thus driving up the ability to form corrosion product, whether precipitate or gelatinous product. As the theta beta increases, the IGC rates increase for a constant potential. By a combination of aspect ratio, φp, thetabeta, and likely fissure chemistry, the potential drop within the fissure is fully described and the IGC penetration rate can be predicted.

Volcanic systems of Iceland and their magma source

NASA Astrophysics Data System (ADS)

Sigmarsson, Olgeir

2017-04-01

Several active hot-spot volcanoes produce magma from mantle sources which composition varies on decadal time scale. This is probably best demonstrated by the recent work of Pietruszka and collaborators on Kilauea, Hawaii. In marked contrast, basalt lavas from volcanic system in Iceland located above the presumed centre of the Iceland mantle plume have uniform isotope composition over the last 10 thousand years. Volcanic systems are composed of a central volcano and a fissure swarm, or a combination of both and they represent a fundamental component of the neovolcanic zones in Iceland. Four such systems, those of Askja, Bárðarbunga, Kverkfjöll and Grímsvötn in central Iceland were chosen for investigation. The last three have central volcanoes covered by the Vatnajökull ice-sheet whereas part of their fissure swarms is ice-free. Tephra produced during subglacial eruptions together with lavas from the fissure swarms of Holocene age have been collected and analysed for Sr, Nd and Th isotope ratios. Those volcanic formations that can be univocally correlated to a given volcanic system display uniform isotope ratio but different from one volcanic system to another. An exception to this regularity is that Askja products have isotope ratios indistinguishable from those of Gímsvötn, but since these volcanic systems lies far apart their lava fields do not overlap. A practical aspect of these findings was demonstrated during the rifting event of Bárðarbunga and fissure eruption forming the Holuhraun lava field. Relatively low, O isotope ratios in these basalts and heterogeneous macrocrystal composition have been ascribed to important metabasaltic crustal contamination with or without crystal mush recycling. In that case a surprisingly efficient magma mixing and melt homogenization must have occurred in the past beneath the volcanic systems. One possibility is that during the rapid deglaciation much mantle melting occurred and melts accumulated at the mantle-crust boundary or within the crust in magma reservoirs that are still feeding the volcanic systems. A second possible explanation for absence of temporal variations of isotope ratios for a given volcanic system during the last 10 thousand years is that the roots of these systems lie at further depths within the mantle. In that case, extensive fertile source rock of recycled origin with distinct isotope composition must feed the volcanic system and that the melt extraction mechanism from these source regions does not alter (or homogenize) the final melt products. The consequences of these two mechanisms and possible discrimination between them will be discussed.

Overview of the precursors and dynamics of the 2012-13 basaltic fissure eruption of Tolbachik Volcano, Kamchatka, Russia

NASA Astrophysics Data System (ADS)

Belousov, Alexander; Belousova, Marina; Edwards, Benjamin; Volynets, Anna; Melnikov, Dmitry

2015-12-01

We present a broad overview of the 2012-13 flank fissure eruption of Plosky Tolbachik Volcano in the central Kamchatka Peninsula. The eruption lasted more than nine months and produced approximately 0.55 km3 DRE (volume recalculated to a density of 2.8 g/cm3) of basaltic trachyandesite magma. The 2012-13 eruption of Tolbachik is one of the most voluminous historical eruptions of mafic magma at subduction related volcanoes globally, and it is the second largest at Kamchatka. The eruption was preceded by five months of elevated seismicity and ground inflation, both of which peaked a day before the eruption commenced on 27 November 2012. The batch of high-Al magma ascended from depths of 5-10 km; its apical part contained 54-55 wt.% SiO2, and the main body 52-53 wt.% SiO2. The eruption started by the opening of a 6 km-long radial fissure on the southwestern slope of the volcano that fed multi-vent phreatomagmatic and magmatic explosive activity, as well as intensive effusion of lava with an initial discharge of > 440 m3/s. After 10 days the eruption continued only at the lower part of the fissure, where explosive and effusive activity of Hawaiian-Strombolian type occurred from a lava pond in the crater of the main growing scoria cone. The discharge rate for the nine month long, effusion-dominated eruption gradually declined from 140 to 18 m3/s and formed a compound lava field with a total area of 36 km2; the effusive activity evolved from high-discharge channel-fed 'a'a lavas to dominantly low-discharge tube-fed pahoehoe lavas. On 23 August, the effusion of lava ceased and the intra-crater lava pond drained. Weak Strombolian-type explosions continued for several more days on the crater bottom until the end of the eruption around 5 September 2013. Based on a broad array of new data collected during this eruption, we develop a model for the magma storage and transport system of Plosky Tolbachik that links the storage zones of the two main genetically related magma types of the volcano (high-Al and high-Mg basalts) with the clusters of local seismicity. The model explains why precursory seismicity and dynamics of the 2012-13 eruption was drastically different from those of the previous eruption of the volcano in 1975-76.

Magma plumbing in the Grímsvötn volcanic system, Iceland: an overview

NASA Astrophysics Data System (ADS)

Thordarson, T.

2016-12-01

The basaltic Grímsvötn volcanic system (GVS) consists of Grímsvötn central volcano (GCV) and an immature fissure swarm extending 70 km to the southwest from GCV. The GCV has the highest eruption frequency of all central volcanos in Iceland, or 7 events per 100 years. In contrast, the GVS fissure swarm has only featured two events in postglacial times, the 1783-4 Laki and the prehistoric Lambavatnsgígar fissure eruptions. These two events account for 25% of the total Holocene magma output from the GVS and 80% of the output in historic time (i.e. last 1100 years). Although GVS magma plumbing has been a topic of research for four decades, its general structure, extent and geometry is still deliberated. Is mantle-derived magma delivered straight up beneath the GCV to an upper crustal magma chamber and then vertically to eruptions at the GCV and laterally to eruption on the GVS fissure swarm? Or does the system feature two levels of crustal storage, one in the upper crust beneath GCV and another at mid-crustal depth? Or is the structure of the GVS plumbing more complex? The data that we have so far and is pertinent to GVS magma plumbing is summarised below: Geophysical measurements imply that shallowest magma storage beneath GCV is at 3-4 km. The Zr and Nb concentrations in the tephra from the 1998 and 2004 GCV plus Laki eruptions show that the parent magmas for each was produced by different degrees of partial melting of a similar mantle source. It also demonstrates transport to the surface via separate pathways and that neither magma can be derived by fractional crystallization from a Laki-like magma. Detailed petrological studies on the Laki tephra and lava indicate polybaric magma evolution within the mid-crust (at 6 to 15 km depth), with further evolution at shallower depths induced either by disequilibrium crystal growth during ascent of magma from the mid-crust storage or a brief residence at 3-6 km depths. The Laki magma contains significant abundances of polymineralic glomerocrysts, signifying that erupted magma interacted with preexisting crystal mushes. These data support the notion of a crustal plumbing system with multiple storage level involving polybaric magma evolution and are inconsistent with the idea that all of the magma erupted within the GVS is delivered from a single upper crustal magma chamber beneath GCV.

76 FR 40293 - Proposed Amendment of Class D and Modification of Class E Airspace; Grand Junction, CO

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-08

... Junction, Walker Field. DATES: Comments must be received on or before August 22, 2011. ADDRESSES: Send... E airspace areas to update the airport name from Grand Junction, Walker Field, to Grand Junction...

76 FR 56966 - Amendment of Class D and Modification of Class E Airspace; Grand Junction, CO

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-15

... and Class E airspace to update the airport name from Grand Junction, Walker Field. DATES: Effective... airspace to update the airport name from Grand Junction, Walker Field, to Grand Junction Regional Airport...

Holographic s-wave and p-wave Josephson junction with backreaction

NASA Astrophysics Data System (ADS)

Wang, Yong-Qiang; Liu, Shuai

2016-11-01

In this paper, we study the holographic models of s-wave and p-wave Josephoson junction away from probe limit in (3+1)-dimensional spacetime, respectively. With the backreaction of the matter, we obtained the anisotropic black hole solution with the condensation of matter fields. We observe that the critical temperature of Josephoson junction decreases with increasing backreaction. In addition to this, the tunneling current and condenstion of Josephoson junction become smaller as backreaction grows larger, but the relationship between current and phase difference still holds for sine function. Moreover, condenstion of Josephoson junction deceases with increasing width of junction exponentially.

Tight junctions and the modulation of barrier function in disease

PubMed Central

2008-01-01

Tight junctions create a paracellular barrier in epithelial and endothelial cells protecting them from the external environment. Two different classes of integral membrane proteins constitute the tight junction strands in epithelial cells and endothelial cells, occludin and members of the claudin protein family. In addition, cytoplasmic scaffolding molecules associated with these junctions regulate diverse physiological processes like proliferation, cell polarity and regulated diffusion. In many diseases, disruption of this regulated barrier occurs. This review will briefly describe the molecular composition of the tight junctions and then present evidence of the link between tight junction dysfunction and disease. PMID:18415116

Multifluxon dynamics in driven Josephson junctions

NASA Astrophysics Data System (ADS)

Lawrence, Albert; Kim, Nung Soo; McDaniel, James; Jack, Michael

1985-06-01

The dynamics of fluxons in a long Josephson junction driven by time-varying nonuniform bias currents are described by a generalization of the sine-Gordon equation. This equation has solitary wave solutions which correspond to current vortices or quantized packets of magnetic flux in the junction. As with the sine-Gordon equation, multifluxon solutions may be demonstrated for the long Josephson junction. Our numerical calculations show that several fluxons may be launched or annihilated at the end of a junction. We also show multiple steady state conditions which correspond to one or more flux quanta trapped in the junction.

Garlic (Allium sativum) feeding impairs Sertoli cell junctional proteins in male Wistar rat testis: microscopy study.

PubMed

Hammami, I; Nahdi, A; Atig, F; El May, A; El May, M V

2016-12-01

Sertoli cell junctions, such as adhesion junction (AJ), gap junction (GJ) and tight junction (TJ), are important for maintaining spermatogenesis. In previous studies, we showed the inhibitory effect of crude garlic (Allium sativum, As) on spermatogenesis and steroidogenesis. The aim of this work was to complete our investigation on the impact of this plant, especially on Sertoli cell junctional proteins (SCJPs). During 1 month, 24 male rats were divided into groups: group control (0% of As) and treated groups fed 5%, 10% and 15% of As. Light and electron microscopy observations were performed to localise junctional proteins: connexin-43, Zona Occluding-1 and N-cadherin (immunohistochemistry) and to describe junctions. We showed that the specific cells involved in the localisation of the SCJP were similar in both control and treated groups, but with different immunoreactivity intensity between them. The electron microscopy observation focused on TJs between Sertoli cells, constituting the blood-testis barrier, showed ultrastructural changes such as fragmentation of TJs between adjacent Sertoli cell membranes and dilatation of rough endoplasmic reticulum saccules giving an aspect of scale to these junctions. We concluded that crude garlic consumption during 1 month induces perturbations on Sertoli cell junctions. These alterations can explain apoptosis in testicular germ cells previously showed. © 2016 Blackwell Verlag GmbH.

Neisseria gonorrhoeae breaches the apical junction of polarized epithelial cells for transmigration by activating EGFR

PubMed Central

Edwards, Vonetta L.; Wang, Liang-Chun; Dawson, Valerie; Stein, Daniel C.; Song, Wenxia

2017-01-01

Summary Neisseria gonorrhoeae initiates infection at the apical surface of columnar endocervical epithelial cells in the female reproductive tract. These cells provide a physical barrier against pathogens by forming continuous apical junctional complexes between neighbouring cells. This study examines the interaction of gonococci (GC) with polarized epithelial cells. We show that viable GC preferentially localize at the apical side of the cell–cell junction in polarized endometrial and colonic epithelial cells, HEC-1-B and T84. In GC-infected cells, continuous apical junctional complexes are disrupted, and the junction-associated protein β-catenin is redistributed from the apical junction to the cytoplasm and to GC adherent sites; however, overall cellular levels remain unchanged. This redistribution of junctional proteins is associated with a decrease in the ‘fence’ function of the apical junction but not its ‘gate’ function. Disruption of the apical junction by removing calcium increases GC transmigration across the epithelial monolayer. GC inoculation induces the phosphorylation of both epidermal growth factor receptor (EGFR) and β-catenin, while inhibition of EGFR kinase activity significantly reduces both GC-induced β-catenin redistribution and GC transmigration. Therefore, the gonococcus is capable of weakening the apical junction and polarity of epithelial cells by activating EGFR, which facilitates GC transmigration across the epithelium. PMID:23279089

Characterization of the column and autocellular junctions that define the vasculature of gill lamellae.

PubMed

Kato, Akira; Nakamura, Korefumi; Kudo, Hisayuki; Tran, Yen Ha; Yamamoto, Yoko; Doi, Hiroyuki; Hirose, Shigehisa

2007-09-01

Novel adhesion junctions have been characterized that are formed at the interface between pillar cells and collagen columns, both of which are essential constituents of the gill lamellae in fish. We termed these junctions the "column junction" and "autocellular junction" and determined their molecular compositions by immunofluorescence microscopy using pufferfish. We visualized collagen columns by concanavalin A staining and found that the components of integrin-mediated cell-matrix adhesion, such as talin, vinculin, paxillin, and fibronectin, were concentrated on plasma membranes surrounding collagen columns (column membranes). This connection is analogous to the focal adhesion of cultured mammalian cells, dense plaque of smooth muscle cells, and myotendinous junction of skeletal muscle cells. We named this connection the "column junction." In the cytoplasm near the column, actin fibers, actinin, and a phosphorylated myosin light chain of 20 kDa are densely located, suggesting the contractile nature of pillar cells. The membrane infoldings surrounding the collagen columns were found to be connected by the autocellular junction, whose components are highly tyrosine-phosphorylated and contain the tight junction protein ZO-1. This study represents the first molecular characterization and fluorescence visualization of the column and autocellular junctions involved in both maintaining structural integrity and the hemodynamics of the branchial lamellae.

Tight junctions and human diseases.

PubMed

Sawada, Norimasa; Murata, Masaki; Kikuchi, Keisuke; Osanai, Makoto; Tobioka, Hirotoshi; Kojima, Takashi; Chiba, Hideki

2003-09-01

Tight junctions are intercellular junctions adjacent to the apical end of the lateral membrane surface. They have two functions, the barrier (or gate) function and the fence function. The barrier function of tight junctions regulates the passage of ions, water, and various macromolecules, even of cancer cells, through paracellular spaces. The barrier function is thus relevant to edema, jaundice, diarrhea, and blood-borne metastasis. On the other hand, the fence function maintains cell polarity. In other words, tight junctions work as a fence to prevent intermixing of molecules in the apical membrane with those in the lateral membrane. This function is deeply involved in cancer cell biology, in terms of loss of cell polarity. Of the proteins comprising tight junctions, integral membrane proteins occludin, claudins, and JAMs have been recently discovered. Of these molecules, claudins are exclusively responsible for the formation of tight-junction strands and are connected with the actin cytoskeleton mediated by ZO-1. Thus, both functions of tight junctions are dependent on the integrity of the actin cytoskeleton as well as ATP. Mutations in the claudin14 and the claudin16 genes result in hereditary deafness and hereditary hypomagnesemia, respectively. Some pathogenic bacteria and viruses target and affect the tight-junction function, leading to diseases. In this review, the relationship between tight junctions and human diseases is summarized.

Synaptopodin couples epithelial contractility to α-actinin-4–dependent junction maturation

PubMed Central

Kannan, Nivetha

2015-01-01

The epithelial junction experiences mechanical force exerted by endogenous actomyosin activities and from interactions with neighboring cells. We hypothesize that tension generated at cell–cell adhesive contacts contributes to the maturation and assembly of the junctional complex. To test our hypothesis, we used a hydraulic apparatus that can apply mechanical force to intercellular junction in a confluent monolayer of cells. We found that mechanical force induces α-actinin-4 and actin accumulation at the cell junction in a time- and tension-dependent manner during junction development. Intercellular tension also induces α-actinin-4–dependent recruitment of vinculin to the cell junction. In addition, we have identified a tension-sensitive upstream regulator of α-actinin-4 as synaptopodin. Synaptopodin forms a complex containing α-actinin-4 and β-catenin and interacts with myosin II, indicating that it can physically link adhesion molecules to the cellular contractile apparatus. Synaptopodin depletion prevents junctional accumulation of α-actinin-4, vinculin, and actin. Knockdown of synaptopodin and α-actinin-4 decreases the strength of cell–cell adhesion, reduces the monolayer permeability barrier, and compromises cellular contractility. Our findings underscore the complexity of junction development and implicate a control process via tension-induced sequential incorporation of junctional components. PMID:26504173

Analyzing phorbol ester effects on gap junctional communication: a dramatic inhibition of assembly

PubMed Central

1994-01-01

The effect of 12-O-tetradeconylphorbol-13-acetate (TPA) on gap junction assembly between Novikoff hepatoma cells was examined. Cells were dissociated with EDTA to single cells and then reaggregated to form new junctions. When TPA (25 nM) was added to the cells at the onset of the 60-min reaggregation, dye transfer was detected at only 0.6% of the cell-cell interfaces compared to 72% for the untreated control and 74% for 4-alpha TPA, an inactive isomer of TPA. Freeze-fracture electron microscopy of reaggregated control cells showed interfaces containing an average of more than 600 aggregated intramembranous gap junction particles, while TPA-treated cells had no gap junctions. However, Lucifer yellow dye transfer between nondissociated cells via gap junctions was unaffected by 60 min of TPA treatment. Therefore, TPA dramatically inhibited gap junction assembly but did not alter channel gating nor enhance disassembly of preexisting gap junction structures. Short term TPA treatment (< 30 min) increased phosphorylation of the gap junction protein molecular weight of 43,000 (Cx43), but did not change the cellular level of Cx43. Cell surface biotinylation experiments suggested that TPA did not substantially reduce the plasma membrane concentration of Cx43. Therefore, the simple presence of Cx43 in the plasma membrane is not sufficient for gap junction assembly, and protein kinase C probably exerts an effect on assembly of gap junctions at the plasma membrane level. PMID:7806568

Design of thin InGaAsN(Sb) n-i-p junctions for use in four-junction concentrating photovoltaic devices

NASA Astrophysics Data System (ADS)

Wilkins, Matthew M.; Gupta, James; Jaouad, Abdelatif; Bouzazi, Boussairi; Fafard, Simon; Boucherif, Abderraouf; Valdivia, Christopher E.; Arès, Richard; Aimez, Vincent; Schriemer, Henry P.; Hinzer, Karin

2017-04-01

Four-junction solar cells for space and terrestrial applications require a junction with a band gap of ˜1 eV for optimal performance. InGaAsN or InGaAsN(Sb) dilute nitride junctions have been demonstrated for this purpose, but in achieving the 14 mA/cm2 short-circuit current needed to match typical GaInP and GaAs junctions, the open-circuit voltage (VOC) and fill factor of these junctions are compromised. In multijunction devices incorporating materials with short diffusion lengths, we study the use of thin junctions to minimize sensitivity to varying material quality and ensure adequate transmission into lower junctions. An n-i-p device with 0.65-μm absorber thickness has sufficient short-circuit current, however, it relies less heavily on field-aided collection than a device with a 1-μm absorber. Our standard cell fabrication process, which includes a rapid thermal anneal of the contacts, yields a significant improvement in diffusion length and device performance. By optimizing a four-junction cell around a smaller 1-sun short-circuit current of 12.5 mA/cm2, we produced an InGaAsN(Sb) junction with open-circuit voltage of 0.44 V at 1000 suns (1 sun=100 mW/cm2), diode ideality factor of 1.4, and sufficient light transmission to allow >12.5 mA/cm2 in all four subcells.

Shear zone junctions: Of zippers and freeways

NASA Astrophysics Data System (ADS)

Passchier, Cees W.; Platt, John P.

2017-02-01

Ductile shear zones are commonly treated as straight high-strain domains with uniform shear sense and characteristic curved foliation trails, bounded by non-deforming wall rock. Many shear zones, however, are branched, and if movement on such branches is contemporaneous, the resulting shape can be complicated and lead to unusual shear sense arrangement and foliation geometries in the wall rock. For Y-shaped shear zone triple junctions with three joining branches and transport direction at a high angle to the branchline, only eight basic types of junction are thought to be stable and to produce significant displacement. The simplest type, called freeway junctions, have similar shear sense in all three branches. The other types show joining or separating behaviour of shear zone branches similar to the action of a zipper. Such junctions may have shear zone branches that join to form a single branch (closing zipper junction), or a single shear zone that splits to form two branches, (opening zipper junction). All categories of shear zone junctions show characteristic foliation patterns and deflection of markers in the wall rock. Closing zipper junctions are unusual, since they form a non-active zone with opposite deflection of foliations in the wall rock known as an extraction fault or wake. Shear zipper junctions can form domains of overprinting shear sense along their flanks. A small and large field example are given from NE Spain and Eastern Anatolia. The geometry of more complex, 3D shear zone junctions with slip parallel and oblique to the branchline is briefly discussed.

Justification of Structural and Technological Solutions on Junction Perfecting on Permyakova and Shirotnaya Streets Intersection in Tyumen

NASA Astrophysics Data System (ADS)

Sannikov, S. P.; Timohovetz, V. D.; Kuzuek, A. Y.

2017-11-01

This article presents the justification of structurally-technological decisions on a junction perfecting on the intersection of Permyakova and Shirotnaya Streets in Tyumen. The authors made a comparative analysis of typical road junctions. Based on the comparison, the engineering decisions were made for an individual type of transport junctions. Several options of individual design were proposed and analyzed and three most suitable types for the road junctions were offered. On the basis of a multilateral studying and evaluation of the developed transport the article further proposed a transport junction with change-side traffic. The use of this type of intersection will increase the road junction capacity, reduce the number of accidents due to conflicting flows reduction which, in its turn, will increase the speed of cars.

Switching and Rectification in Carbon-Nanotube Junctions

NASA Technical Reports Server (NTRS)

Srivastava, Deepak; Andriotis, Antonis N.; Menon, Madhu; Chernozatonskii, Leonid

2003-01-01

Multi-terminal carbon-nanotube junctions are under investigation as candidate components of nanoscale electronic devices and circuits. Three-terminal "Y" junctions of carbon nanotubes (see Figure 1) have proven to be especially interesting because (1) it is now possible to synthesize them in high yield in a controlled manner and (2) results of preliminary experimental and theoretical studies suggest that such junctions could exhibit switching and rectification properties. Following the preliminary studies, current-versus-voltage characteristics of a number of different "Y" junctions of single-wall carbon nanotubes connected to metal wires were computed. Both semiconducting and metallic nanotubes of various chiralities were considered. Most of the junctions considered were symmetric. These computations involved modeling of the quantum electrical conductivity of the carbon nanotubes and junctions, taking account of such complicating factors as the topological defects (pentagons, heptagons, and octagons) present in the hexagonal molecular structures at the junctions, and the effects of the nanotube/wire interfaces. A major component of the computational approach was the use of an efficient Green s function embedding scheme. The results of these computations showed that symmetric junctions could be expected to support both rectification and switching. The results also showed that rectification and switching properties of a junction could be expected to depend strongly on its symmetry and, to a lesser degree, on the chirality of the nanotubes. In particular, it was found that a zigzag nanotube branching at a symmetric "Y" junction could exhibit either perfect rectification or partial rectification (asymmetric current-versus-voltage characteristic, as in the example of Figure 2). It was also found that an asymmetric "Y" junction would not exhibit rectification.

Poster - Thur Eve - 57: Craniospinal irradiation with jagged-junction IMRT approach without beam edge matching for field junctions.

PubMed

Cao, F; Ramaseshan, R; Corns, R; Harrop, S; Nuraney, N; Steiner, P; Aldridge, S; Liu, M; Carolan, H; Agranovich, A; Karva, A

2012-07-01

Craniospinal irradiation were traditionally treated the central nervous system using two or three adjacent field sets. A intensity-modulated radiotherapy (IMRT) plan (Jagged-Junction IMRT) which overcomes problems associated with field junctions and beam edge matching, improves planning and treatment setup efficiencies with homogenous target dose distribution was developed. Jagged-Junction IMRT was retrospectively planned on three patients with prescription of 36 Gy in 20 fractions and compared to conventional treatment plans. Planning target volume (PTV) included the whole brain and spinal canal to the S3 vertebral level. The plan employed three field sets, each with a unique isocentre. One field set with seven fields treated the cranium. Two field sets treated the spine, each set using three fields. Fields from adjacent sets were overlapped and the optimization process smoothly integrated the dose inside the overlapped junction. For the Jagged-Junction IMRT plans vs conventional technique, average homogeneity index equaled 0.08±0.01 vs 0.12±0.02, and conformity number equaled 0.79±0.01 vs 0.47±0.12. The 95% isodose surface covered (99.5±0.3)% of the PTV vs (98.1±2.0)%. Both Jagged-Junction IMRT plans and the conventional plans had good sparing of the organs at risk. Jagged-Junction IMRT planning provided good dose homogeneity and conformity to the target while maintaining a low dose to the organs at risk. Jagged-Junction IMRT optimization smoothly distributed dose in the junction between field sets. Since there was no beam matching, this treatment technique is less likely to produce hot or cold spots at the junction in contrast to conventional techniques. © 2012 American Association of Physicists in Medicine.

dc properties of series-parallel arrays of Josephson junctions in an external magnetic field

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

Lewandowski, S.J.

1991-04-01

A detailed dc theory of superconducting multijunction interferometers has previously been developed by several authors for the case of parallel junction arrays. The theory is now extended to cover the case of a loop containing several junctions connected in series. The problem is closely associated with high-{ital T}{sub {ital c}} superconductors and their clusters of intrinsic Josephson junctions. These materials exhibit spontaneous interferometric effects, and there is no reason to assume that the intrinsic junctions form only parallel arrays. A simple formalism of phase states is developed in order to express the superconducting phase differences across the junctions forming amore » series array as functions of the phase difference across the weakest junction of the system, and to relate the differences in critical currents of the junctions to gaps in the allowed ranges of their phase functions. This formalism is used to investigate the energy states of the array, which in the case of different junctions are split and separated by energy barriers of height depending on the phase gaps. Modifications of the washboard model of a single junction are shown. Next a superconducting inductive loop containing a series array of two junctions is considered, and this model is used to demonstrate the transitions between phase states and the associated instabilities. Finally, the critical current of a parallel connection of two series arrays is analyzed and shown to be a multivalued function of the externally applied magnetic flux. The instabilities caused by the presence of intrinsic serial junctions in granular high-{ital T}{sub {ital c}} materials are pointed out as a potential source of additional noise.« less

The prevalence of increased proximal junctional flexion following posterior instrumentation and arthrodesis for adolescent idiopathic scoliosis.

PubMed

Hollenbeck, S Matt; Glattes, R Christopher; Asher, Marc A; Lai, Sue Min; Burton, Douglas C

2008-07-01

Retrospective case series. To determine the prevalence of proximal junctional sagittal plane flexion increase after posterior instrumentation and arthrodesis. Increased flexion proximal to the junction of the instrumented and fused spinal region with the adjacent mobile spine seems to be a relatively recent observation, may be increasing, and is occasionally problematic. The proximal junctional sagittal angulation 2 motion segments above the upper end instrumentation levels was measured on lateral standing preoperative and follow-up radiographs. One hundred seventy-four of 208 consecutive patients (84%) at an average radiograph follow-up of 4.9 +/- 2.73 years had increased proximal junctional flexion in 9.2%. The preoperative junctional measurements were normal for both normal and increased flexion groups. At follow-up, proximal junctional flexion had increased significantly more in the increased flexion group (2.1 degrees vs. 14.1 degrees , P < 0.0001). None of the possible risk factors studied, including demographic comparisons, Lenke classification (including lumbar and sagittal modifiers), end-instrumented vertebrae, end vertebra anchor configurations, surgical sequence, additional anterior surgery, rib osteotomies, and instrumentation length, were significantly associated with increased proximal junctional flexion at follow-up. Lenke 6 curves were at marginal risk of increased proximal junctional flexion (P = 0.0108). There were no differences between the groups in total Scoliosis Research Society-22r scores at an average follow-up of 8.0 +/- 3.74 years. No patient had additional surgery related to increased proximal junctional flexion. The prevalence of increased proximal junctional flexion was 9.2%. No significant risk factors were identified. Total Scoliosis Research Society-22r scores were similar for groups with normal and increased proximal junctional flexion at follow-up.

High voltage series connected tandem junction solar battery

DOEpatents

Hanak, Joseph J.

1982-01-01

A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

CHLORAL HYDRATE DECREASES GAP JUNCTION COMMUNICATION IN RAT LIVER EPITHELIAL CELLS

EPA Science Inventory

Chloral hydrate decreases gap junction communication in rat liver epithelial cells

Gap junction communication (GJC) is involved in controlling cell proliferation and differentiation. Connexins (Cx) that make up these junctions are composed of a closely related group of m...

Monocytic cell junction proteins serve important roles in atherosclerosis via the endoglin pathway

PubMed Central

Chen, Lina; Chen, Zhongliang; Ge, Menghua; Tang, Oushan; Cheng, Yinhong; Zhou, Haoliang; Shen, Yu; Qin, Fengming

2017-01-01

The formation of atherosclerosis is recognized to be caused by multiple factors including pathogenesis in monocytes during inflammation. The current study provided evidence that monocytic junctions were significantly altered in patients with atherosclerosis, which suggested an association between cell junctions and atherosclerosis. Claudin-1, occludin-1 and ZO-1 were significantly enhanced in atherosclerosis, indicating that the tight junction pathway was activated during the pathogenesis of atherosclerosis. In addition, the gene expression of 5 connexin members involved in the gap junction pathway were quantified, indicating that connexin 43 and 46 were significantly up-regulated in atherosclerosis. Furthermore, inflammatory factors including endoglin and SMAD were observed, suggesting that immune regulative factors were down-regulated in this pathway. Silicon-based analysis additionally identified that connexins and tight junctions were altered in association with monocytic inflammation regulations, endoglin pathway. The results imply that reduced expression of the immune regulation pathway in monocytes is correlated with the generation of gap junctions and tight junctions which serve important roles in atherosclerosis. PMID:28901429

A generic concept to overcome bandgap limitations for designing highly efficient multi-junction photovoltaic cells

PubMed Central

Guo, Fei; Li, Ning; Fecher, Frank W.; Gasparini, Nicola; Quiroz, Cesar Omar Ramirez; Bronnbauer, Carina; Hou, Yi; Radmilović, Vuk V.; Radmilović, Velimir R.; Spiecker, Erdmann; Forberich, Karen; Brabec, Christoph J.

2015-01-01

The multi-junction concept is the most relevant approach to overcome the Shockley–Queisser limit for single-junction photovoltaic cells. The record efficiencies of several types of solar technologies are held by series-connected tandem configurations. However, the stringent current-matching criterion presents primarily a material challenge and permanently requires developing and processing novel semiconductors with desired bandgaps and thicknesses. Here we report a generic concept to alleviate this limitation. By integrating series- and parallel-interconnections into a triple-junction configuration, we find significantly relaxed material selection and current-matching constraints. To illustrate the versatile applicability of the proposed triple-junction concept, organic and organic-inorganic hybrid triple-junction solar cells are constructed by printing methods. High fill factors up to 68% without resistive losses are achieved for both organic and hybrid triple-junction devices. Series/parallel triple-junction cells with organic, as well as perovskite-based subcells may become a key technology to further advance the efficiency roadmap of the existing photovoltaic technologies. PMID:26177808