bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micro‐ and macroelectrochemical investigations of the corrosion behavior of an Al/Mg compound
Authors: Händel M. , Nickel D. , Alisch G. , Lampke T. 
Published: July 2012

AbstractThe motivation for the application of Al/Mg compounds is to achieve significant progress towards lightweight structures. However, they are not used frequently because of the high corrosion susceptibility of magnesium. For this reason, knowledge of the corrosion behavior and the protection against corrosion are essential for the safe use in the component. This article contains results concerning the corrosion characteristics of the unprotected and the plasma‐electrolytically anodized Al/Mg compound. At the same time, the usefulness of microelectrochemical corrosion studies is demonstrated, given that it is possible to check coatings with regard to their permeability due to the high sensitivity of this method. It was found that the coating significantly enhances the corrosion resistance.
Material properties and formability of extruded Al‐Mg compounds as a function of temperature
Authors: Feuerhack A. , Binotsch C. , Awiszus B. , Wolff A. , Brämer C. , Stockmann M. 
Published: July 2012

AbstractDie ersten Untersuchungen der hydrostatisch stranggepressten Al‐Mg Verbunde als Halbzeuge für Folgeprozesse wie Gesenkschmieden verdeutlichen das große Potenzial hybrider Werkstoffverbunde. Die experimentellen Analysen ergaben, dass die Grenzschicht ein hohes Umformvermögen aufweist. Mit verschiedenen Gesenkschmiedeoperationen konnten Umformgrade von 1,50 erreicht werden, ohne dass eine Schädigung in der Grenzschicht auftrat. Die numerischen Untersuchungen ergaben keine signifikanten Dehnungsunterschiede in der Grenzschicht und verdeutlichen somit die Stabilität der Zwischenschicht. Materialkennwerte der stranggepressten Einzelwerkstoffe wurden für unterschiedliche Temperaturen und Umformungsgeschwindigkeiten bestimmt, um zukünftig noch präzisere Simulationen zu ermöglichen.
Fatigue crack propagation in an ECAP‐processed aluminium alloy – influence of shear plane orientation
Authors: Hockauf K. , Hockauf M. , Wagner M. F.‐X. , Lampke T. , Halle T. 
Published: July 2012

AbstractIn this work, the orientation‐dependent fatigue crack propagation behaviour in an ECAP‐processed aluminium alloy is investigated. For a bimodal condition with elongated structures as well as for a homogeneous condition with equiaxed ultrafine grains, the tendency for crack path deviation was evaluated for different sample orientations. In the case of elongated structures, the crack path is deflected towards the elongation plane. However, the angle of deviation differs, depending on whether the fatigue crack propagation rate was in the near‐threshold and lower Paris‐Erdogan regime (higher angle of deviation) or the upper Paris‐Erdogan regime (smaller angle of deviation). Especially in the near‐threshold region, the crack path deviation is linked to higher crack growth rates when compared to ideally straight crack propagation. This effect can be explained by the effects of processing‐induced damage and local stress fields along the elongated structures.
Hypothesis for dimensioning of selected ultra‐fine grained aluminium bolts
Authors: Gröber D. , Georgi W. , Leidich E. , Mayr P. 
Published: July 2012

AbstractBei der angestrebten Energie‐ und Ressourceneinsparung in zukünftigen Leichtbaukonzepten spielen lösbare mechanische Verbindungen aus Aluminium eine zunehmende Rolle. Großes Potenzial hinsichtlich der Zuverlässigkeit besitzen dabei Schrauben aus ECAP‐iertem Aluminium. Die zur Auslegung notwendigen mechanischen Eigenschaften sind noch nicht ausreichend erforscht. Im vorliegenden Artikel werden daher aktuelle Ergebnisse von Schwingfestigkeits‐ und Betriebsfestigkeitsuntersuchungen von Aluminiumschrauben M10x50 aus den Werkstoffen EN‐AW 6082 und EN AW 6082 ECAP‐iert optimiert vorgestellt und mit denen der Serienschraube aus EN‐AW 6056 verglichen. Diese Erkenntnisse werden zur Beschreibung der Versagensursachen herangezogen und am Beispiel einer Fehlerbaumanalyse dargestellt.
Influencing the residual stresses in the surface layer by use of appropriate cutting parameters and tool geometries in turning of aluminium matrix composites
Authors: Schubert A. , Nestler A. , Mehner T. 
Published: July 2012

AbstractSurface properties of components often determine their proper functioning. More complex and increasing demands on operational systems require detailed understanding in the influence of machining on the surface layer. Besides surface structure, residual stresses are very important, especially for dynamically loaded boundary surfaces. But, for cutting of modern light weight construction materials like aluminium matrix composites there is insufficient information concerning residual stresses. On this account, experimental investigations in turning of SiC particle reinforced aluminium matrix composites with different cutting parameters and tool geometries are presented with the focus on residual stresses. They are determined by X‐ray diffraction analysis. The results show that in general the use of very small feeds, tools with a width of flank wear land of about 100 μm, or with a small corner radius cause high absolute values of the compressive residual stresses. In consequence, knowledge of the relation between machining and the residual stress state of the surface layer allows to selectively induce residual stresses in the surface layer. This can provide, for example, an increase of fatigue strength.
Ultrasound‐assisted resistance soldering of aluminium matrix composites
Authors: Weis S. , Wielage B. , Seehofer C. 
Published: July 2012

AbstractFür das Fügen der Aluminiumlegierung EN AW‐6012 und des Aluminiummatrix‐Verbundwerkstoffes EN AW‐2017 + 10 Vol.‐% (Al2O3)P mittels des Zinkbasislotes ZnAl4 wird das ultraschallunterstützte Widerstandslöten angewendet. Untersucht werden die Einflussgrößen Anpresskraft, Transformator‐ und Ultraschallleistung sowie die Auswirkung unterschiedlicher Fügeflächengeometrien auf die Verbindungseigenschaften. Als wesentlicher Indikator dient dabei die Verbindungsfestigkeit, welche im 3‐Punkt‐Biegeversuch ermittelt wird.
Free jejunum reconstruction of upper esophageal defects
Authors: Laing Tereze A. , Van Dam Helena , Rakshit Kaushik , Dilkes Mike , Ghufoor Khalid , Patel Hasu 
Published: July 2012

AbstractThe free jejunum has become an important method for reconstructing extensive oncologic defects of the upper esophagus and pharynx. The advantages of a single‐staged reconstruction with a low incidence of morbidity have generally outweighed criticisms such as the requirement for a laparotomy and poor voice quality. The aim of the study was to present the technique and outcomes of free jejunal reconstruction of the upper esophagus in 31 consecutive cases. We reviewed our experience of free jejunal flaps undertaken over a 6‐year period. Our surgical approach, complications, and results of swallow and speech restoration are described. A functional swallow was achieved by 27/31 patients. However, satisfactory voice restoration was seen in only a small proportion of patients. Complications at the donor site occurred in just one patient. The current review confirms the jejunal flap as a reliable reconstructive option with minimal donor site morbidity. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.
The oblique branch trap in the harvest of the anterolateral thigh myocutaneous flap
Authors: Wong Chin‐Ho 
Published: July 2012

AbstractA 67‐year‐old man with squamous cell carcinoma underwent reconstruction with a free anterolateral thigh myocutaneous flap. Unroofing the skin perforators found that the skin perforators originated from the oblique branch of the lateral circumflex femoral artery with no connections with the descending branch. Thus, the flap was harvested based on the oblique branch, leaving the descending branch in situ. Reconstruction was completed uneventfully and he had an excellent outcome at 1‐year follow‐up. The anterolateral thigh myocutaneous flap was reputed to be a technically easy flap to harvest. The perforators supplying the skin were visualized and a block of muscle incorporating the perforators harvested with the descending branch of the lateral circumflex femoral artery as the pedicle of the flap. However, not infrequently with this approach, the flap thus harvested has a well‐perfused muscle component, whereas the skin component was not viable. This situation is explained anatomically by the potential occurrence of an alternative pedicle that supplies the anterolateral thigh flap, called the oblique branch of the lateral circumflex femoral artery. Our case presented here was a “classic” intraoperative finding of this potential trap and the importance of defining the anatomy before committing oneself to the harvest by unroofing all the skin perforators was emphasized. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Transfer of two motor branches of the anterior obturator nerve to the motor portion of the femoral nerve: An anatomical feasibility study
Authors: Goubier Jean‐Noël , Teboul Frederic , Yeo Sitienehin 
Published: July 2012

AbstractFemoral nerve lesions are uncommon, but very distressing at the functional level because of the absence of knee locking mechanism by the quadriceps muscle. We propose here a new neurotization procedure of obturator nerve motor branches to the motor portion of the femoral nerve in the thigh. This study was conducted on five cadavers. The motor portion of the femoral nerve and the motor branches of the obturator nerve, supplying the gracilis and adductor longus muscles, were isolated. The distance between nerve endings and diameter were measured to determine if a direct neurorrhaphy was possible between the femoral nerve and the two united branches of the obturator nerve. The overlap between the two nerve endings was 26 mm on average, and the mean diameter of the two nerve endings was 3.6 mm for the united branches of the obturator nerve and 3.7 mm for the femoral nerve. Thus, a direct suture was possible in all cases. In this anatomical study, access to the femoral nerve and two united branches of the obturator nerve was easy, in contrast to transfer in the pelvis. Moreover, direct suture without tension was possible in all cases. Thus, this transfer is simple and perfectly reproducible and may have a clinical application in proximal femoral nerve injuries. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Vascular endothelial growth factor‐loaded poly(lactic‐co‐glycolic acid) microspheres‐induced lateral axonal sprouting into the vein graft bridging two healthy nerves: Nerve graft prefabrication using controlled release system
Authors: Karagoz Huseyin , Ulkur Ersin , Kerimoglu Oya , Alarcin Emine , Sahin Cihan , Akakin Dilek , Dortunc Betul 
Published: July 2012

AbstractThe most commonly used surgical technique for repairing segmental nerve defects is autogenous nerve grafting; however, this method causes donor site morbidity. In this study, we sought to produce prefabricated nerve grafts that can serve as a conduit instead of autologous nerve using a controlled release system created with vascular endothelial growth factor (VEGF)‐loaded poly(lactic‐co‐glycolic acid) (PLGA) microspheres. The study was performed in vitro and in vivo. For the in vitro studies, VEGF‐loaded PLGA microspheres were prepared. Thirty rats were used for the in vivo studies. Vein grafts were sutured between the tibial and peroneal nerves in all animals. Three groups were created, and an epineural window, partial incision, and microsphere application were performed, respectively. Walking track analysis, morphologic, and electron microscopic assessment were performed at the end of the eight weeks. Microspheres were produced in spherical shapes as required. Controlled release of VEGF was achieved during a 30‐days period. Although signs of nerve injury occurred initially in the partial incision groups according to the indexes of peroneal and tibial function, it improved gradually. The index values were not affected in the other groups. There were many myelinated fibers with large diameters in the partial incision and controlled release groups, while a few myelinated fibers that passed through vein graft in the epineural window group. Thereby, prefabrication was carried out for the second and third groups. It was demonstrated that nerve graft can be prefabricated by the controlled delivery of VEGF. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Anti‐inflammatory effects of anthocyanins from black soybean seed coat on the keratinocytes and ischemia‐reperfusion injury in rat skin flaps
Authors: Kim Hye Jung , Xu Lianji , Chang Ki Churl , Shin Sung Chul , Chung Jong Il , Kang Dawon , Kim Sang‐Hyon , Hur Ji An , Choi Tae Hyun , Kim Sukwha , Choi Jaehoon 
Published: July 2012

AbstractIschemia‐reperfusion injury is a phenomenon that occurs when tissues are subjected to ischemia for a variable period of time, and then reperfused. Inflammatory reaction has been implicated as one of the most important mechanism of ischemia‐reperfusion injury. The purpose of this study was to evaluate the anti‐inflammatory effects of anthocyanins from black soybean seed coat on keratinocytes in vitro and ischemia‐reperfusion injury in vivo. We investigated the inhibition, by anthocyanins, of the expression of various inflammatory genes associated with ischemia‐reperfusion injury in the tumor necrosis factor‐alpha‐treated (TNF‐α) immortalized epidermal keratinocyte cell line (HaCaT). We also investigated the effects of anthocyanins on the survival of skin flaps after ischemia‐reperfusion injury in the rats. According to Western blot analysis and a luciferase activity assay, anthocyanins inhibited TNF‐α‐induced intercellular adhesion molecule‐1 and cyclooxygenase‐2 (COX‐2) levels through the NF‐κB‐dependent pathway. Administration of anthocyanins (50 and 100 mg/kg) significantly improved the flap area survival in the 10‐hour ischemic model from 62% to 74.5% and 83%, respectively (P = 0.001). The related cytokines in skin flap also changed as the same pattern as in vitro. Our results indicate that anthocyanins from black soybean seed coat had anti‐inflammatory effects on the HaCaT cell line and increase the survival of skin flaps through anti‐inflammatory properties against ischemia‐reperfusion injury. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
A three‐dimensional stereoscopic monitor system in microscopic vascular anastomosis
Authors: Cheng Hsiu‐Ting , MA Hsu , Tsai Chao‐Hsu , Hsu Wei‐Liang , WANG TIEN‐HSIANG 
Published: July 2012

AbstractMicrovascular procedures not only demand precise movements but also usually require a long operation time. Using a conventional surgical microscope, microvascular surgeons need to keep the neck in a fixed flexion posture, which can lead to physical fatigue. Thus, our aim was to develop a three‐dimensional (3D) monitoring system to improve the microsurgery environment. It consists of four main parts: the surgical microscope, the charge‐coupled devices, the 3D multiplexer, and the 3D monitor. Two patients with head and neck cancers who underwent tumor resections were reconstructed with free flap microsurgeries. Both artery anastomoses were completed successfully and the postoperative courses of the two patients were smooth. Vascular anastomosis can be performed successfully with the help of the new 3D display system. Although the artery anastomosis procedures took longer than under a surgical microscope, the 3D system offers another option to improve the working environment for surgeons. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
An algorithm for the calculation of three‐dimensional collagen fiber orientation in ligaments using angle‐sensitive MRI
Authors: Seidel Thomas , Hammer Niels , Garnov Nikita , Schneider Grace , Steinke Hanno 
Published: July 2012

AbstractA method based on angle‐sensitive magnetic resonance imaging for determining unknown orientations of collagen fibers in ligaments is presented. Collagen fibers were stepwise rotated around two independent axes within a 3T magnetic resonance tomograph (from 0° to 180°, step size = 10°). Analyzing the magnetic resonance signal intensity of each voxel as a function of the rotation angle, directions were calculated by means of a computational algorithm. The accuracy of the algorithm was validated using 1000 random test directions, revealing an average deviation of 4.4° (median ± standard deviation: 2.7° ± 9°). Subsequently, the presented method was applied to three specimens of the human iliotibial tract mounted in different directions in a rotatable plastic box. Polarized light microscopy was used to verify parallel alignment of the collagen fibers in the three specimens. The calculated directions were compared with the directions of the specimens. Analyzing each voxel separately, average deviations (median ± standard deviation) in the three specimens were: 11.2° (3.6° ± 20.4°), 12° (5° ± 24.1°), and 20.4° (8.7° ± 27°). If the magnetic resonance signal intensity of each voxel was averaged with the intensity of immediately neighboring voxels, average deviations (median ± standard deviation) were 8.5° (3.6° ± 17.4°), 6.2° (0° ± 18°), and 9.2° (5° ± 19.2°). The presented method has the potential to be applied in situ to anatomical structures like cartilage, ligaments, tendons and fascia. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Fetal ductal constriction caused by maternal ingestion of green tea in late pregnancy: an experimental study
Authors: Zielinsky Paulo , Manica João L. L. , Piccoli Antonio L. , Nicoloso Luiz Henrique S. , Barra Marinez , Alievi Marcelo M. , Vian Izabele , Zilio Ana , Pizzato Patrícia E. , Silva Júlia S. , Bender Luciano P. , Pizzato Marcelo , Menezes Honório S. , Garcia Solange C. 
Published: July 2012

ABSTRACTObjectivesThe aim of this study was to test the hypothesis that experimental maternal intake of green tea in late pregnancy causes fetal ductus arteriosus constriction, probably because of prostaglandin inhibition.Methods and ResultsTwelve fetal lambs (pregnancy > 120 days) were assessed before and after maternal administration of green tea (n = 8) or water (n = 4; controls) as the only source of liquid. After 1 week, echocardiography showed signs of constriction of the ductus arteriosus in all fetuses from mothers ingesting green tea, with increase in mean systolic velocity(from 0.70 ± 0.19 m/s to 0.92 ± 0.15 m/s, 31.4%, p = 0.001) and mean diastolic velocity (0.19 ± 0.05 m/s to 0.31 ± 0.01 m/s, 63.1%, p < 0.001), decrease of pulsatility index (2.2 ± 0.4 to 1.8 ± 0.3, 22.2%, p = 0.003) and increase of mean right ventricular/left ventricular diameter ratio (0.89 ± 0.14 to 1.43 ± 0.23, 60.6%, p < 0.001). In the four control fetuses, there were no significant changes. All lambs exposed to green tea also showed at autopsy dilated and hypertrophic right ventricles, which was not present in control fetuses. Histological analysis showed a significantly larger mean thickness of the medial avascular zone of the ductus arteriosus in fetuses exposed to green tea than in controls (747.6 ± 214.6 µm vs 255.3 ± 97.9 µm, p < 0.001).ConclusionsThis study in fetal lambs shows a cause and effect relationship between experimental maternal exposure of green tea and fetal ductus arteriosus constriction in late pregnancy. © 2012 John Wiley & Sons, Ltd.
Processing and characterization of oriented electrospun poly(vinylidene fluoride) mats
Authors: Gasparini Thiago Manha , Suman Bretas Rosário Elida , da Silva Aline Bruna , Gregorio Rinaldo 
Published: July 2012

AbstractMats of highly oriented poly(vinylidene fluoride) nanofibers were electrospun by means of a conventional electrospinning equipment; the orientation, however, was obtained using a disk collector rotating at a speed of 4000 rpm and a device that reduced the influence of air displacement during nanofiber orientation. Thermal transitions of the mats were determined by differential scanning calorimetry, the predominant crystalline phase by Fourier transform infrared spectroscopy and wide‐angle X‐ray scattering and the nanofiber orientation and morphology by scanning electron microscopy. Relative permittivity, loss index, stable remnant polarization, and coercive field of the mats were also determined and compared with those obtained for a mat electrospun at 2000 rpm and an oriented commercial film. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 000: 000–000, 2012
Effect of HFNC flow rate, cannula size, and nares diameter on generated airway pressures: An in vitro study
Authors: Sivieri Emidio M. , Gerdes Jeffrey S. , Abbasi Soraya 
Published: July 2012

AbstractIncreased use of non‐invasive forms of respiratory support such as CPAP and HFNC in premature infants has generated a need for further investigation of the pulmonary effects of such therapies. In a series of in vitro tests, we measured delivered proximal airway pressures from a HFNC system while varying both the cannula flow and the ratio of nasal prong to simulated nares diameters. Neonatal and infant sized nasal prongs (3.0 and 3.7 mm O.D.) were inserted into seven sizes of simulated nares (range: 3–7 mm I.D. from anatomical measurements in 1–3 kg infants) for nasal prong‐to‐nares ratios ranging from 0.43 to 1.06. The nares were connected to an active test lung set at: TV 10 ml, 60 breaths/min, Ti 0.35 sec, compliance 1.6 ml/cm H2O and airway resistance 70 cm H2O/(L/sec), simulating a 1–3 kg infant with moderately affected lungs. A Fisher & Paykel Healthcare HFNC system with integrated pressure relief valve was set to flow rates of 1–6 L/min while cannula and airway pressures and cannula and mouth leak flows were measured during simulated mouth open, partially closed and fully closed conditions.Airway pressure progressively increased with both increasing HFNC flow rate and nasal prong‐to‐nares ratio. At 6 L/min HFNC flow with mouth open, airway pressures remained <1.7 cm H2O for all ratios; and <10 cm H2O with mouth closed for ratios <0.9. For ratios >0.9 and 50% mouth leak, airway pressures rapidly increased to 18 cm H2O at 2 L/min HFNC flow followed by a pressure relief valve limited increase to 24 cm H2O at 6 L/min.Safe and effective use of HFNC requires careful selection of an appropriate nasal prong‐to‐nares ratio even with an integrated pressure relief valve. Pediatr Pulmonol. 2013; 48:506–514. © 2012 Wiley Periodicals, Inc.