Bent End Research Articles

Железные инструменты для кожевенного производства в пермском Предуралье (эпоха средневековья)

The article deals with a separate group of specialized tannery tools from materials of the Permian Urals in the Middle Ages. The chemical composition of the soils of the region does not provide preservation of organic materials including hides and leather. The main source for studying leather industry in Kama Urals are iron tools. Tools made of iron, in contrast to bone and wooden ones, had a special working part – a sharp blade. First of all, they were intended for scraping, cutting and piercing. The whole toolkit for tannery is represented by scrapers, specialized knives with an upward bent end, awls and needles. Scrapers were a special kind of tools, they are practically not represented in the collections of Eastern Europe and they have not been analyzed in local materials before. In this work, Prikamsky scrapers are first introduced into scientific turnover, analogies to them were found in Western Siberia. To estimate the level of tannery the metallographic analysis of several instruments from each category was performed. For all products, the raw material was mainly steel, less often crystalline iron. The quality of production of all forgings is at a high level, which indicates a conscious approach of the Kama blacksmiths to the manufacture of specialized tools for leather production.

Two new species of Chromadorida (Nematoda) from the intertidal zone of the Yellow Sea, China

ABSTRACT Two new species of free-living marine nematodes were discovered off the coast of the Yellow Sea, China, and they are described here as Actinonema diplobulba sp. nov. and Nannolaimoides brevicaudatus sp. nov. Actinonema diplobulba sp. nov. is characterised by amphideal fovea transverse oval-shaped, pharynx with double posterior bulbs, single spicule slender, arcuate with cephalated proximal end, gubernaculum spinous, and extra hammer-shaped lateral pieces (telamon) present. This species is distinguished from its congeners in having double pharyngeal bulbs and both spicule and telamon. Nannolaimoides brevicaudatus sp. nov. is characterised by a slender body with irregular lateral differentiation, multispiral amphideal fovea with five turns and close to anterior end, spicules arcuate with bent proximal end and tapered distal end, gubernaculum expanded distally and tapered proximally, a precloacal papilla and 14 button-shaped precloacal supplements almost equally arranged, and a conico-cylindrical tail 4.3–4.9 times as long as cloacal body diameter. This species differs from its congeners by having a precloacal papilla and 14 button-shaped precloacal supplements, and a comparatively short conico-cylindrical tail. http://www.zoobank.org/urn:lsid:zoobank.org:pub:D74795FE-168E-4F7F-A78C-08EF5B9783A9

Description of Ektaphelenchus phoenicis n. sp. (Rhabditida: Ektaphelenchinae), a morphological and molecular phylogenetic study

Summary A new species of Ektaphelenchinae was recovered from the bark of a dead date palm (Phoenix dactylifera) tree, and from a soil sample collected from the rhizosphere of gramineous grasses in Iraq and Iran, respectively. It was assigned to the genus Ektaphelenchus mainly by the lack of a functional anus and rectum, and having a conical posterior body end (tail) in female, not ending to a filiform tip, and males lacking a bursa. The recovered populations were described based on morphological and molecular data. Ektaphelenchus phoenicis n. sp. is characterised by 346-441 μm long females, having three lines in lateral field, a 12.3-15.8 μm long stylet with wide lumen lacking basal knobs or swellings, high lip region separated from the rest of body by a depression, metacorpus elliptical with refractive valve plates almost in the middle to slightly posterior, excretory pore posterior to metacorpus, postvulval uterine sac (PUS) 9.3-14.8 μm long, usually containing sperm, posterior body end (tail) with ventrally bent distal end, males common in population with seven precloacal + cloacal + caudal papillae and slightly elevated cloacal lips under SEM, appearing as a differentiated flap-like structure under LM. The new species was morphologically compared with typologically similar species of Ektaphelenchus with a similar body size, namely: E. golestanicus, E. oleae and E. taiwanensis; a similar female posterior body end, namely: E. cupressi, E. kanzakii, E. prolobos and E. riograndensis; and E. goffarti having a similar postcloacal structure. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using near full length sequences of small and D2-D3 expansion segments of large subunit (SSU and LSU D2-D3) rDNA. In both inferred phylogenies, the newly generated sequences of Ektaphelenchus phoenicis n. sp. occupied a placement inside a maximally supported clade including sequences of three genera Ektaphelenchus, Ektaphelenchoides and Devibursaphelenchus.

Treatment of Distal Humerus Articular Fracture with Pin-and-Plate Technique

Background: Distal Humerus Articular Fracture (classified by Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association as 13-B3) is an uncommon fracture with significant complications. We report results of 14 patients treated by open reduction and pin-and-plate fixation technique. Methods: In this retrospective study, we applied pin-and-plate fixation to 14 distal humerus articular fractures, in which screw fixation alone was inefficient or inadequate to provide stable fixation. After anatomical reduction of articular fragments, multiple Kirschner wires were inserted through the fragments. To prevent migration of Kirschner wires a small plate was placed proximally on the bent end of the pins. Results: The average age of 14 patients (8 males and 6 females) was 36.4 years (range: 16-57) and the mean follow up period was 43 months (range: 12-80). At last follow up the average quick Disabilities of the Arm, Shoulder and Hand score was 18.9 (range: 2.3-42.5) and the mean points for Mayo Elbow Performance Index was 75.3 (range: 50-100). Mean final arc of flexion-extension was 97° (range: 40-131). Conclusions: Distal humerus articular fracture is sometimes difficult to fix with conventional methods. We used pin-and-plate technique that could make a stable fixation and allow early range of motion with acceptable results.

Biomechanical comparison of bi- and tricortical k-wire fixation in tension band wiring osteosynthesis

BackgroundPatients with a simple transversal fracture of the olecranon are often treated with a tension band wiring (TBW), because it is known as a biomechanically appropriate and cost-effective procedure. Nevertheless, the technique is in detail more challenging than thought, resulting in a considerable high rate of implant-related complications like k-wire loosening and soft tissue irritation. In the literature, a distinction is generally only made between transcortical (bi-) and intramedullary (mono-) fixation of the wires. There is the additional possibility to fix the proximal bent end of k-wire in the cortex of the bone and thus create a tricortical fixation. The present study investigates the effectiveness of bi- and tricortical k-wire fixation in a biomechanical approach.MethodsTBW of the olecranon was performed at 10 cadaver ulnas from six donors in a usual manner and divided into two groups: In group 1, the k-wire was inserted by bicortical fixation (BC), and in group 2, a tricortical fixation (TC) was chosen. Failure behavior and maximum pullout strength were assessed and evaluated by using a Zwick machine. The statistical evaluation was descriptive and with a paired t test for the evaluation of significances between the two techniques.ResultsThe average age of the used donors was 81.5 ± 11.5 (62–92) years. Three donors were female, and three were male. Ten k-wires were examined in BC group and 10 in the TC group. The mean bone density of the used proximal ulnas was on average 579 ± 186 (336–899) HU. The maximum pullout strength was 263 ± 106 (125–429) N in the BC group and increased significantly in the TC group to 325 ± 102 (144–466) N [p = .005].ConclusionThis study confirms for the first time biomechanical superiority of tricortical k-wire fixation in the olecranon when using a TBW and may justify the clinical use of this method.

A New Coronary Retroinfusion Technique in theRat Infarct Model: Transjugular Cardiac Vein Catheterization

Cell delivery via the retrograde coronary route boasts less vessel embolism, myocardial injury, and arrhythmogenicity when compared with those via antegrade coronary administration or myocardial injection. However, conventional insertion into the coronary sinus and consequent bleeding complication prevent its application in small animals. To overcome the complication of bleeding, we described a modified coronary retroinfusion technique via the jugular vein route in rats with myocardial infarction (MI). A flexible wire with a bent end was inserted into the left internal jugular vein and advanced slowly along the left superior vena cava. Under direct vision, the wire was run into the left cardiac vein by rotating the wire and changing the position of its tip. A fine tube was then advanced along the wire to the left cardiac vein. This modified technique showed less lethal hemorrhage than the conventional technique. Retroinfusion via transjugular catheter enabled efficient fluid or cell dissemination to the majority areas of the free wall of the left ventricle, covering the infarcted anterior wall. In conclusion, transjugular cardiac vein catheterization may make retrocoronary infusion a more safe and practical route for delivering cell, drug, and gene therapy into the infarcted myocardium of rats.

High-Resolution Imaging of Plasmid DNA in Liquids in Dynamic Mode Atomic Force Microscopy Using a Carbon Nanofiber Tip

To understand the motion of DNA and DNA complexes, the real-time visualization of living DNA in liquids is quite important. Here, we report the high-resolution imaging of plasmid DNA in water using a rapid-scan atomic force microscopy (AFM) system equipped with a carbon nanofiber (CNF) probe. To achieve a rapid high-resolution scan, small SiN cantilevers with dimensions of 2 (width) × 0.1 (thickness) × 9 µm (length) and a bent end (tip view structure) were employed as base cantilevers onto which single CNFs were grown. The resonant frequencies of the cantilever were 1.5 MHz in air and 500 kHz in water, and the spring constant was calculated to be 0.1 N/m. Single CNFs, typically 88 nm in length, were formed on an array of the cantilevers in a batch process by the ion-irradiation method. An AFM image of a plasmid DNA taken in water at 0.2 fps (5 s/image) using a batch-fabricated CNF-tipped cantilever clearly showed the helix turns of the double strand DNA. The average helical pitch measured 3.4 nm (σ: 0.5 nm), which was in good agreement with that determined by the X-ray diffraction method, 3.4 nm. Thus, it is presumed that the combined use of the rapid-scan AFM system with the ion-induced CNF probe is promising for the dynamic analysis of biomolecules.

Bending in extrusion of optical fibre preforms

An optical fibre is made by stretching, or `drawing', a glass or polymer preform in a drawing tower. Extrusion through dies has received much recent attention as a suitable method for manufacture of preforms of complex shape and novel material composition. However, the preforms are subject to bending during extrusion, so that the final preform has a bent end that must be removed to yield a straight preform to be drawn into a fibre. Control of bending is needed to improve the efficiency of preform extrusion and reduce wastage of high-cost material. Bending occurs even for simple axisymmetric die geometries and in the absence of heating. Hence, we here examine asymmetry in the applied pressure as a cause of bending. Assuming a linear stress profile, and using a quasi-static approach, we determine the relationship between the magnitude of asymmetry and the amount of bend of the preform, for preforms with circular or annular cross section. We show that significant bend may be caused by an asymmetry that is small relative to the applied pressure. A simple idea for controlling bending is also suggested. Undergraduate university level mathematics is used in the analysis, making this a useful educational illustration of the role of mathematics in understanding engineering problems. References G. Barakos and E. Mitsoulis. Non-isothermal viscoelastic simulations of extrusion through dies and prediction of the bending phenomenon, J. Non-Newtonian Fluid Mech., 62, 1996, 55--79. doi:10.1016/0377-0257(95)01385-7 H. Ebendorff-Heidepriem and T. M. Monro. Extrusion of complex preforms for microstructred optical fibres, Optics Express, 15, 2007, 15086--15092. doi:10.1364/OE.15.015086 H. Ebendorff-Heidepriem, Centre of Excellence in Photonics, The University of Adelaide. Personal communication, 2006--9. A. Karagiannis, A. N. Hrymak and J. Vlachopoulos. Three-dimensional non-isothermal extrusion flows, Rheol. Acta, 28, 1989, 121--133. doi:10.1007/BF01356973 S. C. Warren-Smith, H. Ebendorff-Heidepriem, T. C. Foo, R. Moore, C. Davis and T.M. Monro. Exposed-core microstructured optical fibers for real-time fluorescence sensing, Optics Express, 17, 2009, 18533--18542. doi:10.1364/OE.17.018533

An Archaeal Peptidase Assembles into Two Different Quaternary Structures

Cellular proteolysis involves large oligomeric peptidases that play key roles in the regulation of many cellular processes. The cobalt-activated peptidase TET1 from the hyperthermophilic Archaea Pyrococcus horikoshii (PhTET1) was found to assemble as a 12-subunit tetrahedron and as a 24-subunit octahedral particle. Both quaternary structures were solved by combining x-ray crystallography and cryoelectron microscopy data. The internal organization of the PhTET1 particles reveals highly self-compartmentalized systems made of networks of access channels extended by vast catalytic chambers. The two edifices display aminopeptidase activity, and their organizations indicate substrate navigation mechanisms different from those described in other large peptidase complexes. Compared with the tetrahedron, the octahedron forms a more expanded hollow structure, representing a new type of giant peptidase complex. PhTET1 assembles into two different quaternary structures because of quasi-equivalent contacts that previously have only been identified in viral capsids.

A Modified Rapid Sequence Induction Using the ProSeal™ Laryngeal Mask Airway and an Eschmann Tracheal Tube Introducer or Gum Elastic Bougie

A Modified Rapid Sequence Induction Using the ProSeal™ Laryngeal Mask Airway and an Eschmann Tracheal Tube Introducer or Gum Elastic Bougie

Simple and safe puncture technique for voice prosthesis implantation

A simplified esophagotracheal (ET) puncture technique is described for use instead of the Blom-Singer method for voice prosthesis implantation, with the aim to offer an easier alternative for the same purpose. Study population Of 68 study patients, there were 10 women and 58 men (age range, 46 to 80 years) who had been operated on during a 5-year period with use of this technique. Of the 68 patients, 57 were able to learn to speak in a fluent voice acceptable for everyday communication after the implantation. Seven of the 57 patients had a spasm in the cricopharyngeus muscles and were able to speak only after myotomy. Sixty-eight patients were implanted with voice prosthesis using the ET puncture technique as follows: through the laryngoscope, the distal bent blunt end of the endoextralaryngeal needle carrier is led into the esophagus. The needle with the leading thread (2-0 Prolene) is pushed through in the upper third of the tracheostoma from inside out. Afterward, the cone-trocar catheter is pulled through the stitching canal in the upper third of the tracheostoma. Using the ET puncture technique, the puncture site is the same as with the use of the Blom-Singer method, 5 to 8 mm below the mucocutaneous junction. Then the cone-trocar is cut off from the 18 charrier catheter and the guide wire is pushed inside the catheter through the esophagus, pharynx, and mouth. The voice prosthesis will be fixed on the guide wire and then pulled back in the opening of the fistula. There were no problems or complications with this technique. In 4 cases, the ET puncture could be performed on patients in whom it was not previously possible with the Blom-Singer technique. This management approach offers an alternative to the Blom-Singer technique. The advantage of the ET puncture is that it is simple and safe and that the back wall of the pharynx or esophagus cannot be damaged. Using the ET puncture technique, the possibility of complications is eliminated.

Simple and safe puncture technique for voice prosthesis implantation.

A simplified esophagotracheal (ET) puncture technique is described for use instead of the Blom-Singer method for voice prosthesis implantation, with the aim to offer an easier alternative for the same purpose. Study population Of 68 study patients, there were 10 women and 58 men (age range, 46 to 80 years) who had been operated on during a 5-year period with use of this technique. Of the 68 patients, 57 were able to learn to speak in a fluent voice acceptable for everyday communication after the implantation. Seven of the 57 patients had a spasm in the cricopharyngeus muscles and were able to speak only after myotomy. Sixty-eight patients were implanted with voice prosthesis using the ET puncture technique as follows: through the laryngoscope, the distal bent blunt end of the endoextralaryngeal needle carrier is led into the esophagus. The needle with the leading thread (2-0 Prolene) is pushed through in the upper third of the tracheostoma from inside out. Afterward, the cone-trocar catheter is pulled through the stitching canal in the upper third of the tracheostoma. Using the ET puncture technique, the puncture site is the same as with the use of the Blom-Singer method, 5 to 8 mm below the mucocutaneous junction. Then the cone-trocar is cut off from the 18 charrier catheter and the guide wire is pushed inside the catheter through the esophagus, pharynx, and mouth. The voice prosthesis will be fixed on the guide wire and then pulled back in the opening of the fistula. There were no problems or complications with this technique. In 4 cases, the ET puncture could be performed on patients in whom it was not previously possible with the Blom-Singer technique. This management approach offers an alternative to the Blom-Singer technique. The advantage of the ET puncture is that it is simple and safe and that the back wall of the pharynx or esophagus cannot be damaged. Using the ET puncture technique, the possibility of complications is eliminated.

Ground rotational motions of the 1999 Chi‐Chi, Taiwan earthquake as inferred from dense array observations

Large rotational motions excited by the 1999 Chi‐Chi, Taiwan earthquake are inferred from a dense acceleration array near the northern end of the rupture fault where large surface slips along the fault are observed. The estimated major frequency content is from 0.1 to 1.0 Hz with a peak near 0.2 Hz. It is found that in the footwall region the observed strong rotational ground motions were most probably excited by the slip of the northern rupture ending segment of the Chi‐Chi earthquake fault and that its thrust slips induced a major rock motion in the radial component. The analysis here indicates that during the Chi‐Chi earthquake significant rotation seismic energy was radiated from the bent northern end of the earthquake fault. Further analysis of rotational ground motions may provide useful constraints for its rupture mechanisms.

Different Molecular Conformations in Ferroelectric and Antiferroelectric Liquid Crystals Studied by 19F-NMR Spectroscopy

In order to discuss the relationship between molecular conformation and phase sequence, static 19F-NMR measurements were performed using a high-resolution solid nuclear magnetic resonance spectrometer. In the homologous series of 10BIMFn, dipole coupling constants between fluorines of the phenyl ring and CF3 were found to be larger in the antiferroelectric compounds (n=8 and 10) than in the ferroelectric ones (n=7 and 9). This result indicates that the molecules exhibiting SmC* have a different conformation around the chiral part from those exhibiting SmCA*. Based on the MOPAC calculation in 10BIMF7, which gives two stable conformations with bent and extended chiral end chains, two different conformations obtained by NMR in 10BIMFn are suggested to correspond to the bent and extended structures in antiferroelectric and ferroelectric compounds, respectively.

Management of Pediatric Femoral Fractures using K-Wires

Management of Pediatric Femoral Fractures using K-Wires

Hydro-jet dissection for laparoscopic nephrectomy: a new technique

Objectives. The Hydro-Jet technique has been used to cut various industrial materials. In the medical field, this technique has been successfully used for selective dissection of the parenchyma of organs such as the liver. Recently, this technique was successfully used for laparoscopic cholecystectomy in humans. We developed a new Hydro-Jet probe and a technique of Hydro-Jet dissection during laparoscopic nephrectomy (LN) in a porcine model and compared the results with those of conventional laparoscopy. Methods. Fourteen pigs underwent unilateral LN using the Hydro-Jet and a conventional LN on the contralateral side. A Muritz 1000 Hydro-Jet generator was used. An adjustable water pressure gauge allowed manual control up to a maximum of 30 atm, and coagulation was applied by way of a bipolar thermoapplicator. The bent end of the probe allowed both blunt dissection and concomitant high-pressure water application. Results were compared with regard to ease of anatomic dissection, complications, and operative time between the two techniques. Results. LN was successful in all animals with no conversion to open surgery. The dissector allowed anatomic planes to be created in a relatively bloodless field, and continuous water flow allowed a clear view for the operator. The high-pressure stream resulted in excellent dissection of adventitial and soft tissue adjacent to vascular structures, with complete preservation of vessels and ureter for selective ligation. The dissection time was shortened (mean 27 minutes for the Hydro-Jet versus 40 minutes for the conventional technique). Conclusions. To our knowledge, we describe the first report of Hydro-Jet dissection for LN as an alternative to the conventional technique. The improved anatomic dissection may decrease complications. Moreover, shorter operating times were achieved, which may result in cost savings. Further studies in humans are necessary to investigate this technique.

Object-based visual selective attention and perceptual organization.

We report the results of four experiments that were conducted to examine both the representations that provide candidate entities available for object-based attentional selection and the influence of bottom-up factors (i.e., geometric and surface characteristics of objects) and top-down factors (i.e., context and expectancies) on the selection process. Subjects performed the same task in each of the experiments. They were asked to determine whether two target properties, a bent end and an open end of a wrench, appeared in a brief display of two wrenches. In each experiment, the target properties could occur on a single wrench or one property could occur on each of two wrenches. The question of central interest was whether a same-object effect (faster and/or more accurate performance when the target properties appeared on one vs. two wrenches) would be observed in different experimental conditions. Several interesting results were obtained. First, depending on the geometric (i.e., concave discontinuities on object contours) and surface characteristics (i.e., homogeneous regions of color and texture) of the stimuli, attention was preferentially directed to one of three representational levels, as indicated by the presence or absence of the same-object effect. Second, although geometric and surface characteristics defined the candidate objects available for attentional selection, top-down factors were quite influential in determining which representational level would be selected. Third, the results suggest that uniform connectedness plays an important role in defining the entities available for attention selection. These results are discussed in terms of the manner in which attention selects objects in the visual environment.

Hepatic Vein Catheterization: A New Technique in Rats

Blood samples taken directly from the hepatic veins are often required for evaluation of liver function or ischemia/reperfusion injury and for direct determination of metabolic products of the liver. In the rat, blood samples are usually obtained by direct puncture of the hepatic veins. Successful catheterization of these small vessels is only possible under direct vision because great dexterity is needed to persuade the catheter to enter the hepatic vein. In this report a procedure for hepatic vein catheterization under direct vision is described in the rat. After performing a median laparotomy, a flexible catheter (Buchbinder, 3.0 F/1 mm, as used in cardiology) with a bent end is inserted into the infrahepatic vena cava. Under direct vision through the thin walls of the inferior vena cava the bent end of the catheter is slowly pushed up until the tip slides into a hepatic vein, which opens into the inferior vena cava at a right angle. Selective catheterization of the desired hepatic vein is possible by rotating the catheter and changing the position of its tip. This is a reliable new technique of hepatic vein catheterization in rats, by which blood samples can be collected directly from the hepatic veins.

Mathematical model of rail straightening and experimental estimation of its adequacy

The mathematical model of elasto-plastic rail bending is used to develop a rational technology of rail straightening, determining the point of application of press heads with respect to the length of the bent end, the dimensions and configuration of the surface of heads, the distance between the press supports and the operating travel of the heads. The rational technology of straightening offers minimum residual bending (the bent straightness) of rail ends after straightening, which results in higher durability of the rails.

Tension-band fixation of olecranon fractures: A cadaver study of elbow extension

The loss of extension produced by tension-band wiring was studied using cadaveric elbows. Extension loss was found to be due to impingement of the longitudinal wires against the humerus independent of the tension band. Reducing the size of the bent end of the longitudinal wire is recommended, and bending the wire into a loop achieves this. In addition, passing the tension band through the loops prevents the wire from backing out.