bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling and simulation of explosions in soil interacting with deformable structures
Authors: Zakrisson Björn , Häggblad Hans-Áke , Jonsén Pär 
Published: August 2012

Abstract
A detonating explosive interacting with a deformable structure is a highly transient and non-linear event. In field blast trials of military vehicles, a standard procedure is often followed in order to reduce the uncertainties and increase the quality of the test. If the explosive is buried in the ground, the state of the soil must meet specific demands. In the present work, laboratory experiments have been performed to characterize the behaviour of a soil material. Soil may be considered a three-phase medium, consisting of solid grains, water and air. Variations between the amounts of these phases affect the mechanical properties of the soil. The experimental outcome has formed input data to represent the soil behaviour included in a three-phase elastic-plastic cap model. This unified constitutive model for soil has been used for numerical simulations representing field blast trials, where the explosive load is interacting with a deformable structure. The blast trials included explosive buried at different depths in wet or dry sand. A dependence of the soil initial conditions can be shown, both in the past field trials along with the numerical simulations. Even though some deviations exist, the simulations showed in general acceptable agreement with the experimental results.
Impact damage assessment by using peridynamic theory
Authors: Oterkus Erkan , Guven Ibrahim , Madenci Erdogan 
Published: August 2012

Abstract
This study presents an application of peridynamic theory for predicting residual strength of impact damaged building components by considering a reinforced panel subjected to multiple load paths. The validity of the approach is established first by simulating a controlled experiment resulting in mixed-mode fracture of concrete. The agreement between the PD prediction and the experimentally observed behavior is remarkable especially considering the simple material model used for the concrete. Subsequently, the PD simulation concerns damage assessment and residual strength of a reinforced panel under compression after impact due to a rigid penetrator.
An investigation on low-velocity impact response of elastomeric & crushable foams
Authors: Sadighi Mojtaba , Salami Sattar 
Published: August 2012

Abstract
The mechanical behavior of elastomeric foam, in particular, Ethylene Propylene Diene Methyle (EPDM) and crushable foams, in particular, Expanded Poly-Propylene (EPP) and Poly Urthane Rigid (PUR), under low-velocity impact are studied experimentally and numerically. At first, these foams were loaded under quasi-static loading in compression. In order to study the dependence of their behavior on strain rate, the loadings were performed in two rates, 3 mm/min and 100 mm/min. The low-velocity impact tests were applied using a drop hammer testing machine. The drop heights of projectile in all tests were 0.5 and 1 m. The thickness effect of specimens on absorption of energy and parameters such as, contact force and displacement of specimens are discussed. Then, the dynamic factors of force and energy for three types of foam are investigated. Since, EPP showed an insensitive property to the thickness of specimen in the impact tests, it is possible to define dynamic factors for different thickness of this type of foam. Finally, all test results are compared with numerical results through implementation of ABAQUS finite element package. Good agreements between numerical results and experimental data show the capability of numerical modeling to fulfill the experimental investigation.
Analysis of CT-based Navigation System for Pedicle Screw Placement
Authors: Hodges Scott D. , Eck Jason C. , Newton Danette 
Published: August 2012

The incidence of pedicle screw breech varies based on anatomic location, body habitus, surgeon experience, spinal deformity, and surgical technique. Pedicle breeches have been reported to occur in up to 40% of screws. The purpose of this retrospective study was to compare the rates of revision of pedicle screw placement when using intraoperative C-arm vs O-arm (Medtronic, Memphis, Tennessee) assessment of pedicle screws. An economic analysis was also performed based on the estimated cost of pedicle screw revision.
Four (1%) of 386 control patients required pedicle screw revision for a breeched pedicle screw not identified with intraoperative C-arm fluoroscopy. In the study group, none of the 331 patients returned to the operating room when O-arm was used to assess pedicle screw placement. Based on the 1% rate of returning to the operating room in the control group, the annual rate of cases nationwide requiring pedicle screw revision would be approximately 2300, with a cost of approximately $40,595,000.
These results suggest that the use of intraoperative O-arm can reduce the need for revision of a breeched pedicle screw. This can potentially lead to a major cost savings.
Surgical Strategy for Ossification of the Posterior Longitudinal Ligament in the Cervical Spine
Authors: Chen Yu , Liu Xiaowei , Chen Deyu , Wang Xinwei , Yuan Wen 
Published: August 2012

Ossification of the posterior longitudinal ligament is a common cause of cervical myelopathy, and controversy remains regarding surgical options. Between January 2004 and December 2007, a total of 164 patients with ossification of the posterior longitudinal ligament in the cervical spine who underwent surgical treatment at the authors’ institution were included in this study. The choice of surgical option was based on pathological extent and cervical alignment. Short-segment pathology was treated via the anterior approach and long-segment pathology via the posterior approach. When the posterior approach was selected, laminoplasty was performed for the patients with cervical lordosis and laminectomy with fusion for those with cervical kyphosis. Consequently, anterior corpectomy and fusion was performed in 91 patients, laminoplasty in 41 patients, and laminectomy and instrumented fusion in 32 patients. The Japanese Orthopedic Association scoring system was used to evaluate patients’ neurological status, and related complications were also recorded. Clinical results between different approaches and techniques were compared at mid-term follow-up.
Based on the results of this study and a review of previous literature, no significant differences existed between different approaches and techniques for patients with mild ossification of the posterior longitudinal ligament, but anterior corpectomy and fusion had significantly better results in patients with severe ossification of the posterior longitudinal ligament. With respect to the posterior approach, laminectomy and instrumented fusion improved the surgical results of patients with cervical kyphosis, but a high incidence of C5 palsy existed simultaneously.
Effects of Interleukin-1 Receptor Antagonist on Collagen and Matrix Metalloproteinases in Stress-shielded Achilles Tendons of Rats
Authors: Ma Yanhong , Yan Xiaoyan , Zhao Huakun , Wang Wei 
Published: August 2012

Based on previous studies showing that interleukin-1 (IL-1) significantly increased after stress shielding, this article reports further research into the possible therapeutic applications of IL-1 receptor antagonist (IL-1Ra).
Forty rats whose left Achilles tendons were denervated and completely stress shielded were divided into 5 groups: 2-week phosphate-buffered saline (PBS); 4-week PBS; 2-week IL-1Ra; 4-week IL-1Ra; and normal control. The Achilles tendons were tested morphologically, and the changes in collagen I and III, matrix metalloproteinases (MMP)-1 and -3, and tissue inhibitors of metalloproteinase (TIMP)-1 were determined. The collagen fibrils in the IL-1Ra groups were morphologically more similar to those in the control group than to those in the PBS groups. The collagen I levels increased in the 2-week groups. Significant differences existed between the PBS and IL-1Ra groups at 4 weeks. The MMP-1 level increased dramatically after stress shielding and increased less in the 2-week IL-1Ra group than in the 2-week PBS group. The degree of decrease of MMP-3 in the IL-1Ra groups was significantly less than that in the PBS groups. The collagen III and TIMP-1 levels continued to increase, and no difference was found between the PBS and IL-1Ra groups. Interleukin-1 receptor antagonist prevented morphological deterioration and collagen metabolism of the denervated Achilles tendons after stress shielding, likely by inhibiting the decline of MMP-3 and increasing MMP-1 levels at an early stage.
Extra-articular Synovial Fluid Extravasation Following Operative Fixation of an Osteochondral Fracture of the Patella
Authors: Marberry Kevin M. , Ginsburg Zach 
Published: August 2012

Osteochondral fracture of the patella following a lateral patellar dislocation can be treated with operative and nonoperative techniques that are dictated by the clinical presentation. In the presence of large fragments following acute fractures, arthroscopic retrieval and fixation are advocated, whereas smaller displaced fragments may be removed and discarded as loose bodies. Several methods of fixation exist for osteochondral fractures of the patella, including the use of cannulated and noncannulated screws.
This article describes a case of an elite competitive swimmer who sustained a lateral patellar dislocation with a large osteochondral fracture of the patella that was treated with open reduction and fixation using absorbable cannulated screws in an inside-out fashion. In the early postoperative period, the patient developed a symptomatic synovial fluid fistula through a cannulated screw to the prepatellar space. The diagnosis of this condition was made clinically and confirmed with noncontrast magnetic resonance imaging 6 weeks postoperatively. The symptoms of pain, skin erythema, and swelling were self-limited and eventually resolved with observation, allowing the athlete to return to his previous activity level. Magnetic resonance imaging 3 years postoperatively showed the complete resolution of the fluid extravasation.
Extra-articular synovial fluid extravasation is as a rare complication following routine knee arthroscopy, accounting for 3.2% of the complications. This article describes a rare, self-limited complication following open fixation of an osteochondral fracture of the patella.
Isolated Tear of the Pectoralis Minor Tendon in a High School Football Player
Authors: Li Xinning , Gorman Matthew T. , Dines Joshua S. , Limpisvasti Orr 
Published: August 2012

Multiple pectoralis major tendon tears have been reported in the literature; however, isolated rupture of the pectoralis minor tendon is rare and has been reported 3 times (4 patients).
This article describes a case of an isolated pectoralis minor tendon tear in a male high school football player after a traumatic injury. The patient was injured while making a tackle and leading with his arm and chest. He presented with left anterior shoulder and chest wall pain with direct tenderness on palpation over the coracoid. Magnetic resonance imaging of the chest revealed an isolated tear of the pectoralis minor tendon with slight retraction and significant edema in the muscle belly. The patient returned to full activities after conservative management.
Although rare, the diagnosis of pectoralis minor tendon rupture should be considered in patients who sustain a contact injury to the shoulder with tenderness on palpation over the coracoid. The mechanism of injury can be related to a direct anterior force to the shoulder, forced external rotation of the arm in slight abduction, or with the arm in extension and shoulder in flexion (eg, blocking in football). The diagnosis can be confirmed with magnetic resonance imaging when edema exists on the medial aspect of the coracoid and extends into the muscle belly. Physical therapy with scapular stabilization exercises and avoidance of abduction and active adduction can be successful in returning these patients to their previous activity levels.
Effect of Nd:YAG Laser Capsulotomy on Refraction in Multifocal Apodized Diffractive Pseudophakia
Authors: Vrijman Violette , van der Linden Jan Willem , Nieuwendaal Carla P. , van der Meulen Ivanka J.E. , Mourits Maarten P. , Lapid-Gortzak Ruth 
Published: August 2012

PURPOSE:
To evaluate the effect on refraction of neodymium:YAG (Nd:YAG) laser posterior capsulotomy for posterior capsule opacification (PCO), and to evaluate the correlation between automated and subjective refraction in multifocal apodized diffractive pseudophakia.

METHODS:
A retrospective study of 75 pseudophakic eyes (50 patients) with multifocal apodized diffractive pseudophakia, treated for PCO with Nd:YAG laser posterior capsulotomy, was performed. Pre- and postintervention values of refractive and visual parameters were compared. The outcomes of autorefraction and subjective refraction were also compared.

RESULTS:

Uncorrected and corrected distance visual acuity improved significantly after Nd:YAG capsulotomy (
P<
.001). No significant changes were noted in defocus equivalent, astigmatic power vectors J
0
and J
45
, and overall blurring strength in subjective refraction and autorefraction. Spherical equivalent changed significantly in autorefraction (
P
=.008), but not in subjective refraction. Autorefraction and subjective refraction were highly correlated in spherical equivalent, defocus equivalent, and blurring strength (r
2
>0.59). In approximately 7% of eyes, a change of more than 0.50 diopters in spherical equivalent in subjective refraction occurred.

CONCLUSIONS:
In most cases, Nd:YAG laser capsulotomy in patients with multifocal pseudophakia did not result in a change in refraction. However, 7% of eyes experienced a significant change in subjective refraction. Autorefraction correlated well with subjective refraction in apodized diffractive multifocal IOLs.
Effect of Combined Topical Heparin and Steroid on Corneal Neovascularization in Children
Authors: Michels Rike , Michels Stephan , Kaminski Stephan 
Published: August 2012

BACKGROUND AND OBJECTIVE:To demonstrate the effect of topical heparin combined with topical steroid on corneal neovascularization (CN) in children.PATIENTS AND METHODS:Four children (5 eyes) with new-onset progressive CN in at least one eye received topical rimexolone or dexamethasone in combination with heparin until complete regression of CN was obtained. The regression of CN was documented by slit-lamp or anterior segment photography.RESULTS:All 5 eyes showed complete regression of CN within 5 months. An anti-angiogenic effect was found as early as 1 week after starting topical combination treatment. No ocular and systemic side effects were detected and treatment was well tolerated by all children. In the 3 eyes with involvement of the optical axis, symmetrical visual acuity was obtained by amblyopia treatment. Recurrence of the CN was detectable in 2 eyes at 1 and 6 months, respectively, after ending combination therapy. Both eyes responded favorably to re-treatment.CONCLUSION:Combination of topical heparin and steroid leads to rapid regression and complete inactivity of CN. This therapeutic approach is promising, especially in children with limited therapeutic alternatives and a high risk for amblyopia.
Comparison of Postoperative Refractive Outcomes: IOLMaster
®
Versus Immersion Ultrasound
Authors: Whang Woong-Joo , Jung Byung-Ju , Oh Tae-Hoon , Byun Yong-Soo , Joo Choun-Ki 
Published: August 2012

BACKGROUND AND OBJECTIVE:
To compare the postoperative refractive outcomes between IOLMaster biometry (Carl Zeiss Meditec, Inc., Dublin, CA) and immersion ultrasound biometry for axial length measurements.

PATIENTS AND METHODS:
Refractive outcomes in 354 eyes were compared using the IOLMaster and the immersion ultrasound biometry. Predicted refraction was determined using manual keratometry and the SRK-T formula with personalized A-constant.

RESULTS:

The axial lengths measured using the IOLMaster and immersion ultrasound were 24.49 ± 2.11 and 24.46 ± 2.11 mm, respectively, and the difference was significant (
P
< .05). The mean errors were 0.000 ± 0.578 D with the IOLMaster, and 0.000 ± 0.599 D with the immersion ultrasound, but the difference was not significant. The mean absolute error was smaller with the IOLMaster than with immersion ultrasound (0.463 ± 0.341 vs 0.479 ± 0.359 D), but the difference was not significant.

CONCLUSION:
IOLMaster biometry yields highly accurate results in cataract surgery. However, if the IOLMaster is unavailable, immersion ultrasound biometry with personalized intraocular lens constants is an acceptable alternative.
Rationale for Performing Penetrating Keratoplasty Rather Than DSAEK in Patients With Bullous Keratopathy in Japan
Authors: Yokogawa Hideaki , Kobayashi Akira , Saito Yoshiaki , Yamazaki Natsuko , Masaki Toshinori , Sugiyama Kazuhisa 
Published: August 2012

BACKGROUND AND OBJECTIVE:
To analyze the rationale for performing penetrating keratoplasty (PK) rather than Descemet’s stripping automated endothelial keratoplasty (DSAEK) in patients with bullous keratopathy (BK) in Japan.

PATIENTS AND METHODS:
A total of 136 eyes of 130 patients with consecutive BK were enrolled. Patients treated by DSAEK were categorized as the DSAEK group. The remaining patients were considered unsuitable for DSAEK due to the presence of risk factors, and were treated by PK (PK group). In both groups, the number of the patients and the causes of BK were analyzed. Also, specifically in the PK group, the reasons for not performing DSAEK were analyzed.

RESULTS:

The causes of BK differed significantly between the two groups (
P
< .001). Risk factors considered unsuitable for DSAEK include significant stromal scarring, iris abnormalities, and lens abnormalities.

CONCLUSION:
For successful DSAEK, risk factors and contraindications should be carefully evaluated before surgery.
Semi‐automated characterisation of seabed pockmarks in the central North Sea
Authors: Gafeira J. , Long D. , Diaz‐Doce D. 
Published: August 2012

ABSTRACTPockmarks are indicators of focused fluid seepage, most notably gas such as methane, and can occur in vast numbers in many marine and even in lacustrine environments. The presence and distribution of pockmarks need to be considered in the development of any infrastructure at the seabed. However, manual mapping of these features can be extremely time‐consuming and it is implicitly subjective.An extensive area in the central North Sea, where the seabed comprises a thick sequence of muds and sandy muds of the late glacial Witch Ground Formation, shows numerous inactive pockmarks, typically 20–100 m diameter and 3–4 m deep. Within this area a few larger, active pockmarks, 500 m diameter and up to 17 m deep are known. Modern site investigations in this area regularly include multibeam sonar mapping, a technique that collects large volumes of bathymetric data that can be used to produce digital depth models of the seafloor with sufficient resolution to characterize individual pockmarks.This paper presents a semi‐automated method to recognize, spatially delineate and characterise morphometrically pockmarks at the seabed. The method comprises two scripts, Pockmark Mapping and Pockmark Characterization, that allow the systematic application of a sequence of well defined tools available within the ESRI ArcGIS toolbox. Almost 4150 pockmarks were mapped applying this method to 18 selected site surveys across the central North Sea. The mapping and morphometric characterization of such vast number of pockmarks allows the identification of certain trends reflecting the hydrodynamic regime, whereas the pockmarks density and spatial distribution appears to be attributable to differences in shallow gas availability and deeper geology controlling fluid migration pathways.
Contribution of high‐resolution 3D seismic near‐seafloor imaging to reservoir‐scale studies: application to the active North Anatolian Fault, Sea of Marmara
Authors: Thomas Y. , Marsset B. , Westbrook G.K. , Grail C. , Géli L. , Henry P. , Çifçi G. , Rochat A. , Saritas H. 
Published: August 2012

ABSTRACTHigh Resolution (HR) marine seismic acquisition contributes to numerous research fields. The vertical resolution is of metric scale in order to study geological processes at a short time scale or to characterise small objects. 3D seismic imaging allows optimal resolution to be reached whereas 2D images are blurred mainly by side effects. Developed for the oil industry decades ago and tailored to the exploration for hydrocarbon reservoirs, 3D seismic, as applied to higher resolution targets, is more recent. Available technological advances in acquisition have allowed research institutes to develop innovative 3D high‐resolution marine seismic systems tailored to these targets.The seismic survey carried out in 2009 on the Western High, Sea of Marmara, illustrates the value of HR3D imaging. Since the destructive İzmit earthquake in 1999, an intensive international research effort has demonstrated that the Western High is one of the key structures for assessing the processes of deformation related to the North Anatolian Fault (NAF). The 30‐km2 HR3D survey centred on the main NAF was acquired using a dual streamers ‐ dual source‐array configuration. In spite of the minimal 3D processing sequence that was applied to the data, the fine imaging of the seabed and of the sedimentary stratigraphy and structures is much better than HR2D seismic. Comparison with an autonomous underwater vehicle (AUV) multi‐beam bathymetric survey carried out at the same location enables the limits of the vertical resolution of the seismic data to be assessed. The lateral resolution is between 13.5 and 25 metres at the seabed. The HR3D seismic data highlight the interplay between tectonic processes and stratigraphy. In particular, differential uplift leads to syntectonic deposition and submarine slides. The widespread occurrence of gas in the sedimentary sequence is clearly shown by anomalously high seismic amplitudes. 3D imaging of these high amplitudes enables the identification of the pathways through faults and permeable units that gas takes as it migrates to the seabed.
An ice‐ moulded surface from the middle Pleistocene of the Central North Sea
Authors: Buckley Francis 
Published: August 2012

ABSTRACTA collection of seismic datasets, including Ultra‐High Resolution 2D, High Resolution 2D and Exploration 3D data, have been compared with geotechnical borehole logs, to investigate a Middle to Late Pleistocene sequence within the Central North Sea (CNS). An Elsterian glacial erosion surface is interpreted to be overlain by a series of seismo‐stratigraphic formations which can mostly be referenced to the accepted stratigraphic model for the area, though with some significant qualifications. Evidence is shown for the presence of at least three grounded ice‐sheets within the Middle‐Late Pleistocene of the CNS, including a previously unreported, pre‐Weichselian, ice‐moulded and lineated surface. The late and post‐glacial history of the CNS is re‐constructed by reference to borehole lithological data, compared with seismic textures. It is proposed that a seismo‐stratigraphic unit at seabed and named in published sources as the late glacial Forth Fm. is much older, with implications for the prediction of geotechnical properties of the unit elsewhere in the region.