Triangular Depression Research Articles

Unique damage process in micro-sized copper single crystal with double-slip orientation in response to near-[112] tension-compression fatigue

In order to clarify the fatigue process for a micro-sized copper (Cu) single crystal with a double-slip orientation, a tension-compression cyclic loading test was carried out with in situ FE-SEM observation. Although the primary slip system B4 finally brought about a crack from eminent intrusions, the process was complex due to characteristic interactions among multiple slip systems. The process was approximately divided into three stages; early slipping, cave-in and damaging. In the early stage, two slip systems with high Schmid factor (SF), B4 and C1, worked at first, however both immediately stopped working. Extrusions/intrusions were caused by the survived slip system B5 (third-highest SF). In the second stage, a triangular depression was brought about by the cross-slip from B5 to C5 and localized wavy undulation was formed by the continuous cross slips. In the final stage, though both of B4 and B5 worked, the slip system with the highest SF, B4, dominated to form the eminent extrusions/intrusions, resulting in the fatigue cracking. The applied resolved shear stress amplitude was a few megapascals, indicating significantly lower fatigue strength than that of the bulk counterpart while it was in same range for that of micro-sized Cu with a single slip orientation. The complex fatigue damage morphology of the specimen was explained by accounting for the interaction of dislocations between the slip systems.

Clinical efficacy and safety of composite non-cross-linked hyaluronic acid for treating tear trough-lower eyelid bag deformity.

Tear trough-eye bag deformities may appear in young Asian patients due to the weak support of their facial skeletons. For these patients with better periorbital skin elasticity, the injection may be more suitable than surgery for treating tear trough-lower eyelid bag deformity. Identify the clinical efficacy and safety of non-cross-linked HA in the treatment of tear trough-lower eyelid bag deformity. In this study, we analyzed pre- and postinjection photographs of 55 patients treated with non-cross-linked hyaluronic acid (HA) for tear trough-lower eyelid bag deformity. The mean [SD] scores of modified Goldberg score suggested that the most significant improvement of preoperative and postoperative scores was in tear trough depression, followed by infraorbital triangular depression, orbital fat prolapse, loss of skin elasticity, and skin transparency. Only transient localized complications were observed, including bruising, swelling, and erythema. There were no serious complications, such as skin necrosis or visual impairment. Our study confirmed the beneficial efficacy and minor complications of composite non-cross-linked HA for the treatment of tear trough-lower eyelid bag deformity.

Theoretical and experimental investigation of a bubble collapsing near an asymmetric hydrofoil

In the present paper, the restricted cavitation bubble dynamics near an asymmetric Joukowsky hydrofoil are investigated theoretically and experimentally. This investigation employs the conformal transformation, the image method, and the Kelvin impulse model, together with high-speed photographic experiments. The characteristics of bubble collapse deformation and bubble wall movement are analyzed qualitatively and quantitatively, and the spatial distributions of the liquid velocity and Kelvin impulse are revealed by theoretical predictions. The main conclusions include (1) the bubble collapse deformations can be divided into three typical cases: penetrating deformation (mostly occurs when γ<2 with γ defined as the bubble-hydrofoil dimensionless distance), triangular depression (mostly occurs when 2<γ<4), and arc-shaped depression (mostly occurs when γ>4). (2) The impulse acting on the bubble is governed by a point source and a point sink, which is dominant, and the impulse is inversely correlated with the bubble-hydrofoil distance, which corresponds to the experimental results. (3) The Kelvin impulse exhibits different distributions at the tail, head, and middle regions of the hydrofoil, and the impulse angle remains basically unchanged in the concave region of the asymmetric hydrofoils (i.e., the range of 240°<θz<350° with θz defined as the bubble position angle).

What’s New in Transradial Access

Transradial access (TRA) is a key strategy to avoid bleeding during percutaneous coronary intervention (PCI) and coronary angiography, as it reduces the risk of bleeding associated with transfemoral access (TFA). The distal radial artery (dRA) is located at the anatomical snuffbox, or radial fossa, which is a triangular depression on the lateral aspect of the dorsum of the hand. Distal transradial access (dTRA) at the anatomical snuffbox has recently gained interest as a non-femoral alternative access route for vascular procedures. Opportunities and challenges in the TRA/dTRA space include adoption of different and more complex procedures, technical innovation in access and haemostasis, and financial savings for institutions and healthcare systems. Historically, the adoption of TRA has been concentrated among interventional cardiologists, with much less adoption in the interventional radiology, vascular surgery, and neurointerventional radiology communities. This article highlights key aspects of the Think Radial webinar, an educational training session conducted by Merit Medical. The training session was conducted by three experts: Sandeep Nathan, Department of Cardiology, University of Chicago Medicine, Illinois, USA; Darren Klass, Department of Radiology, University of British Columbia, Vancouver, and Department of Radiology, Vancouver General Hospital, British Columbia, Canada; and Ajit Puri, New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical Center, Worcester, USA, all of whom have a wealth of experience in vascular access. The experts provided valuable insights into topics such as why and how to adopt a dTRA approach, the value of ultrasound for guided vascular access, and dTRA and ultrasound tips and techniques. The experts also explored the challenges in transradial intervention and management of radial access complications. Drawing on their individual specialist knowledge, the experts concluded with presentations on PCI, radial approaches in interventional radiology, and dRA access in neurointervention. The aim of this educational article is to disseminate key information on TRA provided by the experts to guide and update healthcare practitioners, particularly interventional cardiologists and interventional radiologists, working in vascular access.

Morphometric Study on Types of Asterion in Dry Human Skull of Nepalese Origin

Introduction: The asterion is important bony landmark of skull important for surgical approach to the posterior cranial fossa. The variation is type of asterion is due to presence or absence of lambdoidal suture, parietomastoid suture and occipitomastoid suture. Asterion is starry or triangular depression located 2.5cm behind the upper part of root of ear. Asterion is meeting point of lambdoidal suture, parietomastoid suture and occipitomastoid suture. Materials and Methods: Altogether 26 dry adult human skulls were collected from Department of Anatomy at School of Basic Sciences in Chitwan Medical College for research. Gender and ethnicity were undefined. All damaged skull and newborns are excluded. Both sides of skull were studied for location and type of asterion. The types of asterion were noted by observing the presence or absence of all three sutures. Photograph were taken and studied. Statistical analysis was done using SPSS 17. Results: Twenty-six human skulls of unknown gender were examined. Two types of asterion were observed. The type I asterion was 88.5 percent and type II asterion was 11.5 percent on both side of skull. Conclusion: we believe that there are different types of asterion present in human skull. Asterion is the important surgical landmark. Thereby, the finding may be helpful in surgical approach and intervention.

A new kannemeyeriiform dicynodont (Ufudocyclops mukanelai, gen. et sp. nov.) from Subzone C of the Cynognathus Assemblage Zone, Triassic of South Africa, with implications for biostratigraphic correlation with other African Triassic faunas

ABSTRACTA new taxon of kannemeyeriiform dicynodont, Ufudocyclops mukanelai, is described based on a well-preserved skull from Subzone C of the Cynognathus Assemblage Zone, which are the youngest strata (probably Middle Triassic) of the Beaufort Group (uppermost Burgersdorp Formation) in South Africa. Ufudocyclops mukanelai is diagnosed by its autapomorphic intertemporal morphology: the intertemporal bar in this taxon is ‘X’-shaped—broad anteriorly and posteriorly but distinctly ‘pinched’ at mid-length and bears a deep, triangular depression immediately behind the enormous pineal foramen. The new kannemeyeriiform can also be diagnosed by the presence of a laterally expanded jugal plate beneath the orbit, and highly discrete, ovoid nasal bosses separated by a broad, unornamented median portion of the premaxilla and the nasals. Two partial dicynodont skulls from this subzone, previously identified as specimens of the otherwise Tanzanian taxon Angonisaurus, are also referable to U. mukanelai. Removal of these specimens from the hypodigm of Angonisaurus eliminates a crucial point of correlation between Cynognathus Subzone C and the Manda Beds of Tanzania and suggests that Subzone C preserves a distinct, endemic fauna, not just a southern extension of the better-known Middle–Late Triassic tetrapod faunas from Tanzania and Zambia. Inclusion of Ufudocyclops in a phylogenetic analysis of anomodonts recovers it as an early stahleckeriid, the first record of this clade from the Cynognathus Assemblage Zone.

The skull of the Upper Cretaceous baurusuchid crocodileBaurusuchus albertoiNascimento & Zaher 2010, and its phylogenetic affinities

We here describe the cranial remains of Baurusuchus albertoi Nascimento & Zaher, 2010, a Baurusuchidae from the Upper Cretaceous of Brazil that is known from a partially complete and articulated skeleton. The cranial anatomy provided important new information that allowed a more accurate analysis of its phylogenetic affinities. Phylogenetic results suggest that B. albertoi is the sister-group of a clade formed by Baurusuchus pachecoi and Baurusuchus salgadoensis. Characters that place B. albertoi within the family Baurusuchidae are: antorbital portion of the jugal more than two times higher than the infratemporal part; rod-shaped infratemporal bar of the jugal; dorsal process of the quadratojugal extensively contacting the postorbital; posterolateral process of squamosal totally deflected ventrally; cervical neural spines anteroposteriorly large; spool-shaped vertebral centra; cranial table as wide as ventral portion. Baurusuchus albertoi differs from the remaining two species of the genus by having a more excavated triangular depression of the jugal suborbital portion, an area that is also more ventrally developed; a vertical and lateromedially thin retroarticular process; and descending expansion of the lateral edge of the squamosal anteriorly concave. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163, S116–S131.

Pentagons and Heptagons in the First Water Layer on Pt(111)

Scanning tunneling topography of long-unexplained "square root of 37" and "square root of 39" periodic wetting arrangements of water molecules on Pt(111) reveals triangular depressions embedded in a hexagonal H2O-molecule lattice. Remarkably, the hexagons are rotated 30° relative to the "classic bilayer" model of water-metal adsorption. With support from density functional theory energetics and image simulation, we assign the depressions to clusters of flat-lying water molecules. 5- and 7-member rings of H2O molecules separate these clusters from surrounding "H-down" molecules.

Fine structural analysis on the dry adhesion system of the jumping spider plexippus setipes (Araneae: Salticidae)

The cuticle of spider's exoskeleton is a hydrophobic and non‐adhesive material, but the jumping spiders have the distinctive attachment apparatus for adhesion on smooth dry surface without sticky fluids. We have examined the whole tarsal appendages of the jumping spider, Plexippus setipes with using scanning electron microscope to reveal the fine structural characteristics of the dry adhesion system. All eight legs have the scopulae with a pair of claws on the tip of feet. Each scopula is composed of two groups of setae that are capable of dry adhesion on smooth surface, and the hook structure of the claw is advanced to move on the rough surface. The setae toward the bottom of the tarsal segment are densely covered by numerous setules on the underside which broadened from middle to distal portion. It has been revealed by this research that the contact area of the setule is always a triangular shape, and these cuticular surfaces are connected by the elongated stalks from the underlying setae. It is likely that the nano‐scale structures including a triangular depression and a longitudinal groove on each setule could functionate when the spider detach its feet from the substrate.

Theropithecus atlanticus (Thomas, 1884) (Primates: Cercopithecidae) from the late Pliocene of Ahl al Oughlam, Casablanca, Morocco.

The site of Ahl al Oughlam near Casablanca, Morocco, dated to ca. 2.5 Ma, has yielded a good sample of Theropithecus atlanticus (Thomas, 1884), a North African late Pliocene species previously known only by its holotype, a lower molar from Algeria. Theropithecus atlanticus, which can now be much better defined, is clearly distinct from other species of the genus, which is thus more diverse than previously thought. The mandible of T. atlanticus has a very characteristic deep and long post-molar sulcus and a deep and well excavated supra-lateral triangular depression of the ramus, with a sharp postero-inferior ridge. The upper and lower canines are rather large but low. The male P3 is very wide, with well developed posterior crests; the P4 is rounded, with a large talonid and weak notches and clefts. Median lingual notches of the lower molars form an acute angle. Although our incomplete knowledge of T. atlanticus precludes a detailed phylogenetic analysis, we suggest that it arose by cladogenesis from the T. darti-T. oswaldi lineage; it is replaced by the latter species in the Pleistocene.

Lead isotope systematics of epigenetic lead-zinc mineralization in the western part of the Rheinisches Schiefergebirge, Germany

In the western part of the Rheinisches Schiefergebirge three different types of epigenetic lead-zinc vein mineralization in Paleozoic rocks can be distinguished: 1. Syntectonic Variscan veins, 2. post-Variscan (Saxonian) veins mainly in Paleozoic siliceous clastic rocks, 3. post-Variscan carbonate-hosted mineralization in the Aachen-Stolberg area. Ore impregnations occur in the Triassic Buntsandstein (Bunter sandstone) and Muschelkalk of the Maubach-Mechernich triangular depression covering the Paleozoic rocks. Data points define two distinct populations in both lead isotope diagrams and thus indicate two major Variscan and post-Variscan mineralization events. The lead isotope pattern of the Paleozoic sedimentary rocks bears good evidence that this thick rock sequence may be the main source of metals for the mineralization. The metals were mobilized at deeper levels by saline fluids at different times. There are no direct indications for remobilization of the older Variscan vein ore deposits. The sandstone- and carbonate-hosted ore impregnations of Maubach-Mechernich have a similar lead isotope pattern to the post-Variscan mineralization in the Paleozoic sedimentary basement.

Ultramorphology of some boraginaceous taxa used as Ratanjot

AbstractThe present study was undertaken with a view to determine some ultramorphological characters which could help in characterizing various boraginaceous taxa used as ‘Ratanjot’ in the traditional Indian system of medicine. Some of the distinguishing characters of the species studied are: broad two armed hair basis with triangular depression at the proximal end in Arnebia benthamii; the surface of upper epidermal cells tracheal shaped in A. euchroma; the hair bases saucer shaped with warty blobs in A. nobilis; the basal cells of large hairs digitally arranged in Maharanga emodi; and similarly these are arranged in cystolith‐like fashion in Onosma hispidum.

The Caveate Pollen of Streptosiphon hirsutus (Acanthaceae: Acantheae) and Its Taxonomic Significance

The pollen morphology of Streptosiphon hirsutus Mildbr. is described and illustrated with light, scanning and transmission electron microscopy. The pollen is isopolar, prolate to subprolate, 3-colpate, with a triangular outline in polar view and a rectangular outline in equatorial view. The surface is perforate on the apices of the mesocolpia, and perforate and fossulate towards the apertures. On each apocolpium is a triangular depression with a granular protuberance at the pole. The exine stratification is complex and is believed to be unique to this species. At each mesocolpial apex of the grain is a double arcade of columellae, separated by a cavea. The foot layer is discontinuous. The endexine is highly fractionated and lamellated at the colpi. The pollen morphology confirms the position of Streptosiphon as a separate genus within the Acantheae and suggests affinities with Crossandra Salisbury and Crossandrella C. B. Clarke.

Topographic organization of substance p and monoamine cells in the ventral medulla of the cat

A topographic map of the substance P and monoamine neurons in the ventrolateral medulla of the cat has been constructed from peroxidase anti-peroxidase immunohistochemically stained sections. The coordinates of this map use the foramen cecum of the medulla oblongata (i.e. the triangular depression at the junction between the caudal boundary of the pons and the rostral limit of the median fissure between the pyramidal tracts) as the zero point. Two distinct groups of substance P neurons have been found: a rostral group lies ventral to the facial nucleus and a caudal one is found ventrolateral to the inferior olivary nucleus. Two dopamine β-hydroxylase-containing cell groups were identified that correspond to the A1 and A5 cell groups. The A5 cell group lies dorsal, lateral and caudal to superior olivary nucleus. The A1 cell group lies ∼4.0–5.0 mm lateral to the midline at the level of the inferior olive; these cells lie mainly dorsolateral to the region of the magnocellular division of the lateral reticular nucleus. The B1 and B3 serotonin (5-hydroxytryptamine) cell groups of the ventrolateral medulla appear to form a continuous column with a rostral and a caudal swelling. The rostral group begins at the level of the facial nucleus (−4 mm caudal to the foramen cecum) and is concentrated in the area just lateral to the pyramidal tract. It becomes reduced in size ∼8.0 mm caudal to the foramen cecum, and then enlarges to form a caudal group (∼10 mm caudal to foramen cecum). Portions of this column overlap with the caudal substance P cell group. The C1 cell group lies in a restricted zone ∼4.0 mm lateral to the midline at the level of the rostral part of the inferior olivary nucleus.

A model of the geoelectric structure beneath Japan.

A quantitative evaluation of the geoelectric subterranean model beneath Japan is made on the basis of the analyses of short-period geomagnetic variations. For the model it has been surmised that the surface of a highly conducting mantle layer must steeply drop to a depth of 200km or so from a depth of 40-50km beneath the Pacific coast of central Japan. The depression seems likely to become shallower toward the Japan Sea underneath which the depth of the layer again reaches 40km.As the above “depression model” was derived on the basis of a perfect conductor approximation, it is important to see whether the model can account for the frequency characteristics of geomagnetic variation as brought out by intensive observations in recent years.The electromagnetic response of a conductive half-space having a triangular depression on its surface is estimated entirely numerically. Similar studies are also made for a case in which thin conductive sheets representing the sea are added. It turns out that the model seems likely to account for the characteristics of geomagnetic variations having a period range of a few tens of minutes. Although there is no guarantee for uniqueness, the depression model cannot be ruled out as a possible geoelectric structure beneath Japan.

The identification and some properties of point defects and non-basal dislocations in molybdenite surfaces

From electron and optical microscopic studies of the topography of oxidized and cleaved basal faces of naturally occurring single crystals of molybdenite, quantitative estimates of both the density of (surface) point-defects and non-basal dislocations have been made. The point defects, probably vacancies, were rendered detectable by a combination of anisotropic oxidation (which ‘expands’ the defects in two dimensions parallel to the basal plane) and gold-decoration. The conditions for both the oxidation, to yield volatile products and triangular depressions, and the decoration, to facilitate the surface migration of gold, are critical. The gold-decoration technique is shown to be capable (i) of revealing ‘monomolecular’ (i. e. unit layer thickness of 6.15 Å ) steps and triangular depressions, (ii) of delineating pinned basal-plane dislocations lying close to the surface, and (iii) of discriminating, in principle, between ‘surface’ and ‘bulk’ defect concentration. For samples of molybdenite emanating from Australia, Korea and the United States, no significant differences in point-defect concentrations are detectable; and the density of defects at the surface (10 7 cm -2 ) is roughly equal to that in the bulk. Terraced depressions, penetrating ten to twelve layers, are thought to be associated with the termini of non-basal edge dislocations, the geometry of which is outlined. Non-basal screw dislocations are detected entirely by optical microscopy, chiefly because the Burgers vectors of such dislocations fall in the range 300 to 4000 Å, a situation reminiscent of natural graphite. Their density is ca . 10 3 cm -2 and many are inclined to the c -axis. From the dimensions of pits and depressions produced by oxidation it is possible to make order of magnitude estimates of the degree of kinetic anisotropy associated with the reaction at specific surface locations. The values of the ratio of the rate of oxidation along the c -axis to that along the basal planes, R c/a , at 600 °C, is found to be 10 -1 at (emergent) non-basal screw-dislocations, 10 -2 at non-basal edge dislocations, and 10 -11 at ‘ideal’ sites in the basal surface. The preferred direction of cleavage steps, which originate at the cores of forest screw dislocations, is <112̄0>, indicating that the interfacial energy, in air, of the {101̄l} face is smaller than that of {112̄l}. The techniques described should now be applicable to the study of defects in other layer structures.

Gold-decoration of topographical features at surfaces of synthetic molybdenum disulphide

It is confirmed that the gold-decoration technique is capable of revealing monolayer steps of 6.15 Å at molybdenite surfaces; and the supposition that individual vacancies are detectable is strongly supported by the observed orientation of triangular depressions, formed as a result of anisotropic oxidation at vacancies in the surface layer. Stacking faults may also be detected from the orientation of oxidation-etch pits, and the nature of the stacking faults, involving one or more infractions to the regular stacking sequence, is discussed.

Laser-induced Damage in Diamond

AN observation of laser-induced damage in clear diamond has recently been reported1 and the conclusions there drawn are that damage occurred on the exit face only and that small holes cannot be drilled because of damage by acoustic phonons. This is contrary to our experience. Using a ruby laser operating in relaxation oscillations with an output of only 0.2 joule and a beam divergence of 3 milliradians, we can produce a hole with two laser shots. Fig. 1 shows such a hole of 40µ diameter through a diamond plate 0-5 mm thick cut parallel to the (110) plane. The laser beam was focused on to the front (110) surface by a plano-convex lens of 17 mm focal length, creating a triangular depression in this surface. Blackening of the walls of the hole also occurred, probably due to graphitization. This diamond plate had also been hit by the same laser operating with a rotating prism Q-switch to give a 5 MW pulse, beam divergence 1 milliradian, focused by an 8-mm microscope objective. Under these conditions blackening and damage occurred on the exit surface only and can be seen on the right of Fig. 1. The microscope objective was wrecked in the process.

Protection of the recurrent laryngeal nerves in thyroidectomy

1. 1. In the past injury to the recurrent laryngeal nerves has been of much concern to the thyroid surgeon. Many technics have been improvised to prevent injury to the nerves but too often these methods complicate or prolong the operation unnecessarily. 2. 2. In our experience injury usually occurs when attempts are made to control hemorrhage. It is well known that the nerve is most vulnerable where it lies in close proximity to the inferior thyroid artery. This is the danger area. 3. 3. At this point a triangular depression is seen when the lobe of the gland is elevated. This depression might be called an artefact because it is not an anatomic depression but a surgical one. It is this depression which must be avoided. 4. 4. The technic presented, we believe, not only avoids injury to the nerves but also simplifies thyroidectomy in such a way as to make hemorrhage a rarity.

On a Foramen in the Lower Extremity of the Humerus

DURING flexion of the forearm the coronoid fossa of the humerus receives the coronoid process of the ulna. On the posterior surface above the trochlea is a deep triangular depression, the olecranon fossa, in which the summit of the olecranon is received in extension of the forearm. These two fossae are separated from one another by a thin, more or less transparent lamina of bone, lined in the fresh state by the synovial membrane of the elbow joint.1 The plate of bone separating the coronoid and the olecranon fossae may be perforated. This opening is called the supratrochlear foramen.2 It is a more or less oval or elliptical opening with a smooth margin and sloping edges with the long axis transverse, about 5 to 9 mm. wide and 3 to 4 mm. high. It is located above the epiphyseal line and is in the intra-articular part of the olecranon fossa below the line of reflection of the synovial membrane which crosses the middle of the fossa. When large, the hole is actually in an open state; when small, it may be cover...