Sample records for unilateral zmc fractures

  1. Unilateral Pedicle Fracture Accompanying Spondylolytic Spondylolisthesis

    PubMed Central

    Kim, Hyeun Sung; Ju, Chang Il; Kim, Yun Sung

    2015-01-01

    Unilateral pedicle stress fracture accompanying spondylolytic spondylolisthesis is rare even in the elderly. Most are associated with major trauma, previous spine surgery, or stress-related activity. Here, the authors describe an unique case of unilateral pedicle fracture associated with spondylolytic spondylolisthesis at the L5 level, which was successfully treated by posterior lumbar interbody fusion with screw fixation at the L5-S1 level. As far as the authors' knowledge, no such case has been previously reported in the literature. The pathophysiological mechanism of this uncommon entity is discussed and a review of relevant literature is included. PMID:26180621

  2. Unilateral Mydriasis After Mandibular Fracture Fixation Surgery

    PubMed Central

    Nesioonpour, Sholeh; Khiabani, Kazem; Hassanijirdehi, Marzieh

    2014-01-01

    Introduction: Unilateral mydriasis is a seriously significant finding in neurologic examinations indicating life-threatening conditions such as cerebral vascular injuries. Case Presentation: A 24 year old woman with mandibular trauma was referred to our center after five days for a reduction of the right mandibular angle fracture. The patient had no history of any loss of consciousness after the accident. Her physical examination showed no abnormalities, except those related to her mandibular fracture. The laboratory results were normal as well. At 8:30 am a general anesthesia was induced. The patient’s eyes were kept shut throughout the surgical procedure. The operation included an intraoral open reduction and fixation using two miniplates without any complications. After the operation, it was noticed that the left eye was completely dilated with no reaction to light, while the right eye was normal. The management and outcomes in this patient were described in the present case report. Conclusions: Evaluating the size of the patient’s pupils before, during and after the operation, careful history, consult, CT scan and MRI would help to diagnosis. Although no probable cause was found to explain the transient mydriasis in our patient. PMID:24829881

  3. Three-dimensional assessment of unilateral subcondylar fracture using computed tomography after open reduction

    PubMed Central

    Devireddy, Sathya Kumar; Kumar, R. V. Kishore; Gali, Rajasekhar; Kanubaddy, Sridhar Reddy; Rao, Dasari Mallikarjuna; Siddhartha, Mannava

    2014-01-01

    Objective: The aim was to assess the accuracy of three-dimensional anatomical reductions achieved by open method of treatment in cases of displaced unilateral mandibular subcondylar fractures using preoperative (pre op) and postoperative (post op) computed tomography (CT) scans. Materials and Methods: In this prospective study, 10 patients with unilateral sub condylar fractures confirmed by an orthopantomogram were included. A pre op and post op CT after 1 week of surgical procedure was taken in axial, coronal and sagittal plane along with three-dimensional reconstruction. Standard anatomical parameters, which undergo changes due to fractures of the mandibular condyle were measured in pre and post op CT scans in three planes and statistically analysed for the accuracy of the reduction comparing the following variables: (a) Pre op fractured and nonfractured side (b) post op fractured and nonfractured side (c) pre op fractured and post op fractured side. P < 0.05 was considered as significant. Results: Three-dimensional anatomical reduction was possible in 9 out of 10 cases (90%). The statistical analysis of each parameter in three variables revealed (P < 0.05) that there was a gross change in the dimensions of the parameters obtained in pre op fractured and nonfractured side. When these parameters were assessed in post op CT for the three variables there was no statistical difference between the post op fractured side and non fractured side. The same parameters were analysed for the three variables in pre op fractured and post op fractured side and found significant statistical difference suggesting a considerable change in the dimensions of the fractured side post operatively. Conclusion: The statistical and clinical results in our study emphasised that it is possible to fix the condyle in three-dimensional anatomical positions with open method of treatment and avoid post op degenerative joint changes. CT is the ideal imaging tool and should be used on a regular basis for cases of condylar fractures. PMID:25190915

  4. Occipital Condyle Fracture With Isolated Unilateral Hypoglossal Nerve Palsy

    PubMed Central

    Yoon, Jin Won; Lim, Oh Kyung; Park, Ki Deok

    2014-01-01

    Occipital condyle fractures (OCFs) with selective involvement of the hypoglossal canal are rare. OCFs usually occur after major trauma and combine multiple fractures. We describe a 38-year-old man who presented with neck pain and a tongue deviation to the right side after a traffic accident. Severe limitations were detected during active and passive range of neck motion in all directions. A physical examination revealed a normal gag reflex and normal mobility of the palate, larynx, and shoulder girdle. He had normal taste and general sensation in his tongue. However, he presented with a tongue deviation to the right side on protrusion. A videofluoroscopic swallowing study revealed piecemeal deglutition due to decreased tongue mobility but no aspiration of food. Plain X-ray film findings were negative, but a computed tomography study with coronal reconstruction demonstrated a right OCF involving the hypoglossal canal. An electrodiagnostic study revealed evidence of right hypoglossal nerve palsy. We report a rare case of isolated hypoglossal nerve palsy caused by an OCF. PMID:25379499

  5. Kinematic simulation of fracture reduction and bone deformity correction under unilateral external fixation.

    PubMed

    Kim, Yoon Hyuk; Inoue, Nozomu; Chao, Edmund Y S

    2002-08-01

    Combined kinematic analysis and graphic models of two unilateral external fixators are presented to simulate and visualize the correction of bone fracture deformities through systematic adjustments of the fixator joints. The models were developed as rigid linkage systems, and the analysis utilized the 4x4 transformation matrices and the kinematic chain theory to obtain the necessary rotations and translations at each joint of the fixator to correct bone deformities at the fracture site. Three-dimensional malalignments with fracture gaps were simulated to correct the deformities. Due to the redundant pair variables in the fixator joints and other problems in obtaining unique solutions, an optimization technique was used to solve the governing linkage loop equations. For each adjustment solution, the bone correction paths were infinite but a unique and optimal reduction path was obtained by applying corrections to all joints simultaneously and in small increments. When the deformity exceeded a certain range, no admissible solution could be obtained, partially due to the limitation of the unilateral fixator configuration and partially due to the restricted joint rotation and translation in the fixator design. The present models and analysis technique can be used to investigate a fixator's adjustability to correct a 3-D bone deformity at a fracture or lengthening site facilitating patient care planning and medical personnel training. PMID:12126664

  6. Development and validation of a new approach for computer-aided long bone fracture reduction using unilateral external fixator

    Microsoft Academic Search

    T. K. K. Koo; E. Y. S. Chao; A. F. T. Mak

    2006-01-01

    An innovative computer-aided method to plan and execute long bone fracture reduction using Dynafix™ unilateral external fixator (EF) is presented and validated. A matrix equation, which represents a sequential transformation from proximal to distal ends, was derived and solved for the amount of rotation and translation required at each EF joint to correct for a displaced fracture using a non-linear

  7. Prosthetic rehabilitation of a patient with unilateral dislocated condyle fracture after treatment with a mandibular repositioning splint: a clinical report.

    PubMed

    Noh, Kwantae; Choi, Woojin; Pae, Ahran; Kwon, Kung-Rock

    2013-06-01

    This clinical report describes the use of a mandibular repositioning splint and the subsequent prosthodontic treatment of a unilateral dislocated condyle fracture for a patient whose injury resulted in significant mandibular deviation and malocclusion. The use of a mandibular repositioning splint considerably reduced the mandibular deviation, and a stable mandibular position was maintained with the definitive prosthesis. PMID:23763780

  8. Unilateral atlanto-axial fractures in near side impact collisions: An under recognized entity in cervical trauma

    PubMed Central

    Lozen, Andrew M.; Pace, Jonathan; Yoganandan, Narayan; Pintar, Frank A.; Cusick, Joseph F.

    2014-01-01

    Objective: Nearside impact collisions presenting with lateral mass fractures of atlanto-axial vertebrae contralateral to the impact site represents a rare fracture pattern that does not correlate with previously described injury mechanism. We describe our clinical experience with such fractures and propose a novel description of biomechanical forces involved in this unique injury pattern. The findings serve to alert clinicians to potentially serious consequences of associated unrecognized and untreated vertebral artery injury. Material and Methods: In addition to describing our clinical experience with three of these fractures, a review of Crash Injury Research and Engineering Network (CIREN) database was conducted to further characterize such fractures. A descriptive analysis of three recent lateral mass fractures of the atlanto-axial segment is coupled with a review of the CIREN database. A total of 4047 collisions were screened for unilateral fractures of atlas or axis. Information was screened for side of impact and data regarding impact velocity, occupant injuries and use of restraints. Results: Following screening of unilateral fractures of atlas and axis for direct side impacts, 41 fractures were identified. Cross referencing these cases for occurrence contralateral to side of impact identified four such fractures. Including our recent clinical experience, seven injuries were identified: Five C1 and two C2 fractures. Velocity ranged from 14 to 43 km/h. Two associated vertebral artery injuries were identified. Conclusions: Complexity of the atlanto-axial complex is responsible for a sequence of events that define load application in side impacts. This study demonstrates the vulnerability of vertebral artery to injury under unique translational forces and supports the use or routine screening for vascular injury. Diminished sensitivity of plain radiography in identifying these injuries suggests that computerized tomography should be used in all patients wherein a similar pattern of injury is suspected. PMID:25013345

  9. Continuous paravertebral infusion of ropivacaine with or without fentanyl for pain relief in unilateral multiple fractured ribs

    PubMed Central

    Mohta, Medha; Ophrii, Emeni L; Sethi, Ashok Kumar; Agarwal, Deepti; Jain, Bhupendra Kumar

    2013-01-01

    Background: Continuous thoracic paravertebral block (TPVB) provides effective analgesia for unilateral multiple fractured ribs (MFR). However, prolonged infusion of local anaesthetic (LA) in high doses can predispose to risk of LA toxicity, which may be reduced by using safer drugs or drug combinations. This study was conducted to assess efficacy and safety of paravertebral infusion of ropivacaine and adrenaline with or without fentanyl to provide analgesia to patients with unilateral MFR. Methods: Thirty adults, having ?3 unilateral MFR, with no significant trauma outside chest wall, were studied. All received bolus of 0.5% ropivacaine 0.3 ml/kg through paravertebral catheter, followed by either 0.1-0.2 ml/kg/hr infusion of ropivacaine 0.375% with adrenaline 5 ?g/ml in group RA or ropivacaine 0.2% with adrenaline 5 ?g/ml and fentanyl 2 ?g/ml in group RAF. Rescue analgesia was provided by IV morphine. Results: Statistical analysis was performed using unpaired Student t-test, Chi-square test and repeated measures ANOVA. After TPVB, VAS scores, respiratory rate and PEFR improved in both groups with no significant inter-group differences. Duration of ropivacaine infusion, morphine requirements, length of ICU and hospital stay, incidence of pulmonary complications and opioid-related side-effects were similar in both groups. Ropivacaine requirement was higher in group RA than group RAF. No patient showed signs of LA toxicity. Conclusion: Continuous paravertebral infusion of ropivacaine 0.375% with adrenaline 5 ?g/ml at 0.1-0.2 ml/kg/hr provided effective and safe analgesia to patients with unilateral MFR. Addition of fentanyl 2 ?g/ml allowed reduction of ropivacaine concentration to 0.2% without decreasing efficacy or increasing opioid-related side-effects. PMID:24403614

  10. Monte Carlo Modeling of Diffuse Scattering from Single Crystals: The Program ZMC

    SciTech Connect

    Goossens, D.J.; Heerdegen, A.P.; Chan, E.J.; Welberry, T.R. (ANU)

    2012-04-30

    Diffuse scattering probes the local ordering in a crystal, whereas Bragg peaks are descriptive of the average long-range ordering. The population of local configurations can be explored by modeling the three-dimensional distribution of diffuse scattering. Local configurations are not constrained by the average crystallographic symmetry, so one way of modeling diffuse scattering is by modeling a disordered (short-range-ordered) structure and then calculating its diffuse scattering. The structure must contain enough unit cells to give a statistically valid model of the populations of local configurations, and so requirements for a program to model this ordering are very different from programs that model average crystal structures (used to fit the Bragg diffraction). ZMC is a program that has been developed to model diffuse scattering, particularly from molecular crystals. The strategies used to tackle the problem and the way in which they are implemented will be discussed.

  11. Unilateral posterior vertebral column resection for severe thoracolumbar kyphotic deformity caused by old compressive vertebrae fracture: a technical improvement

    PubMed Central

    Wang, Hui; Zhang, Di; Sun, Ya-Peng; Ma, Lei; Ding, Wen-Yuan; Shen, Yong; Zhang, Ying-Ze

    2015-01-01

    Severe thoracolumbar kyphotic deformity caused by old compressive vertebrae fracture remains a big challenge for spine surgeons. When symptoms related to significant deformities cannot be adequately managed conservatively, posterior vertebral column resection (PVCR) is required, but with long operating time and severe blood loss. We develop a UPVCR technique, which is done through a unilateral approach instead of a bilateral approach, vertebral body resection advancing to cross the midline in an abrasive way from an extreme oblique orientation enable the resection of most contralateral vertebral body. In the present study, the effects of UPVCR for severe thoracolumbar kyphotic deformity were investigated. We did find that satisfactory correction of sagittal deformity, functional improvement and pain relief can be achieved by UPVCR, and it has the advantage of shortening surgery time, reducing blood loss and incidence of nerve root impingement over PVCR.

  12. Management of tripod fractures (zygomaticomaxillary complex) 1 point and 2 point fixations: A 5-year review

    PubMed Central

    Balakrishnan, K.; Ebenezer, Vijay; Dakir, Abu; Kumar, Saravana; Prakash, D.

    2015-01-01

    The zygomaticomaxillary complex (ZMC) plays a key role in the structure, function, and esthetic appearance of the facial skeleton. They can account for approximately 40% of mid-face fractures. They are the second most common facial bone fracture after nasal bone injuries. The fracture complex results from a direct blow to the malar eminence and results in three distinct fracture components that disrupt the anchoring of the zygoma. In addition, the fracture components may result in impingement of the temporalis muscle, trismus (difficulty with mastication) and may compromise the infraorbital foramen/nerve resulting in hypesthesia within its sensory distribution. A 4-year retrospective review of all patients treated with ZMC fractures at oral and maxillofacial surgery department, sree balaji dental college and hospital was performed. Computed tomography scans were reviewed. Demographics, treatment protocols, outcomes, complications, reoperations, and length of follow-up were identified. A total of 245 patients was identified by the Current Procedural Terminology codes for ZMC fractures. Closed or open reduction methods were performed with the goal of treatment being preservation of normal facial structure, sensory function, globe position, and mastication functionality. Unacceptably poor surgical outcomes are uncommon. Significant facial asymmetry requiring surgical revision occurs in 3-4% of patients. Postoperative infection rates are extremely low, and these infections nearly always resolve with oral antibiotics. In general, the long-term prognosis after repair of ZMC fractures is very good. PMID:26015723

  13. [Unilateral borderline ovarian tumor and unilateral adenexectomy?].

    PubMed

    Boujenah, J; Bricou, A; Moreaux, G; Grynberg, M; Sifer, C; Hugues, J N; Poncelet, C

    2014-09-01

    To perform an adnexectomy in case of unilateral borderline tumor must consider the risk of recurrence, the preservation of fertility, and to integrate a global comprehensive management of a couple. Adnexectomy can be considering as a legitimate option when the woman desire a pregnancy. The risk of recurrence is low and the global survey high. Identification of woman with a high risk of recurrence is necessary. Adnexectomy can be considering as a legitimate option to preserve fertility in case of unilateral tumor. However, ovarian reserve data are missing after the surgery. Adnexectomy can be considering for the management of infertile woman with unilateral borderline tumor. IVF can be performed in the absence of any poor prognosis factor. Management with ovarian cryopreservation and In vitro Maturation remain unclear. PMID:25164163

  14. Acute unilateral ophthalmoplegia

    Microsoft Academic Search

    Acute ophthalmoplegia is defined as an ophthalmoplegia which reaches maximum intensity within one week of onset. It may be partial or complete. In this case report we introduce a 4.5 year-old girl with diplopia, pain in left eye and head tilt. After complete evaluation, she has been operated with diagnosis of left orbital floor fracture and entrapment of left inferior

  15. Isolated unilateral rupture of the alar ligament.

    PubMed

    Wong, Sui-To; Ernest, Kimberly; Fan, Grace; Zovickian, John; Pang, Dachling

    2014-05-01

    Only 6 cases of isolated unilateral rupture of the alar ligament have been previously reported. The authors report a new case and review the literature, morbid anatomy, and pathogenesis of this rare injury. The patient in their case, a 9-year-old girl, fell head first from a height of 5 feet off the ground. She presented with neck pain, a leftward head tilt, and severe limitation of right rotation, extension, and right lateral flexion of the neck. Plain radiographs and CT revealed no fracture but a shift of the dens toward the right lateral mass of C-1. Magnetic resonance imaging of the cervical spine showed signal hyperintensity within the left dens-atlas space on both T1- and T2-weighted sequences and interruption of the expected dark signal representing the left alar ligament, suggestive of its rupture. After 12 weeks of immobilization in a Guilford brace, MRI showed lessened dens deviation, and the patient attained full and painless neck motion. Including the patient in this case, the 7 patients with this injury were between 5 and 21 years old, sustained the injury in traffic accidents or falls, presented with marked neck pain, and were treated with external immobilization. All patients had good clinical outcome. The mechanism of injury is hyperflexion with rotation. Isolated unilateral alar ligament rupture is a diagnosis made by excluding associated fracture, dislocation, or disruption of other major ligamentous structures in the craniovertebral junction. CT and MRI are essential in establishing the diagnosis. External immobilization is adequate treatment. PMID:24679079

  16. Monitoring and healing analysis of 100 tibial shaft fractures

    Microsoft Academic Search

    L. Claes; R. Grass; T. Schmickal; B. Kisse; C. Eggers; H. Gerngroß; W. Mutschler; M. Arand; T. Wintermeyer; A. Wentzensen

    2002-01-01

    Background. We assessed the value of measuring biomechanical stiffness by assessing the fixator's external deformation as an objective means for monitoring fracture healing and determining the postoperative treatment regime, as compared to clinical and radiographic means of evaluation. Patients and methods. One hundred patients with tibial shaft fractures managed by unilateral external fixation had their fracture stiffness monitored. Stiffness was

  17. Optic nerve trauma with unilateral edema as a result of head injury

    Microsoft Academic Search

    Henry J. Carson; Daniel Lingamfelter; Mary H. Dudley

    2010-01-01

    We encountered a patient who suffered a head injury that translated to the optic nerves, leading to dramatic unilateral right optic nerve edema. The decedent was a 20-year-old unsecured passenger in a convertible. The car collided with a pickup truck. The patient survived for 8 h. At autopsy, a comminuted skull fracture involving the right frontal bone including the right orbital

  18. Managing advanced unilateral pseudoexfoliative glaucoma.

    PubMed

    Marques, André

    2014-01-01

    The only proven therapy for glaucoma is intraocular pressure (IOP) reduction, which can be accomplished by different means. Each should be properly discussed with patients in order to best preserve visual function and quality of life. We report a case of unilateral pseudoexfoliative glaucoma, treated for years with triple topical IOP-lowering drugs. The patient presented with advanced optic neuropathy and important ocular side effects secondary to the treatment. Having discussed his options and prognosis, laser trabeculoplasty was performed while maintaining the remaining therapy considering the advanced stage of glaucoma. His IOP was effectively reduced and no progression was noted after 1-year follow-up. Although medical therapy is the mainstream in glaucoma management, its side effects should not be ignored, especially in unilateral cases. Surgery might have been a better solution, but we chose to perform laser trabeculoplasty, an effective and safer alternative, considering the unlikely but serious risk of the "wipe-out phenomenon" in this case. PMID:24850557

  19. Audiological assessment of unilateral deafness.

    PubMed

    Pruszewicz, A; Obrêbowski, A; Woznica, B; Sekula, A; Swidzi?ski, P; Karlik, M

    2001-01-01

    Unilateral deafness constitute medical (aetiological diagnosis, treatment, hearing aid fitting) and social problems (no certification of disability). Following audiological examinations were performed in the study: pure tone audiometry (PTA), impedance audiometry, auditory brainstem responses (ABR), otoacoustic emissions (OAE), as well as balance, taste, examinations and electric sensitivity of the acoustic nerve. In cases of tinnitus the parameters of its character were done. All of our patients underwent X-ray investigations, i.e. ear X-ray by Schüller and Stenvers methods, computerized tomography or magnetic resonance imaging. In some cases phoniatric and logopaedic examinations were performed. For aetiological diagnosis electrophoresis and immunological test (IgG and IgM against mumps) were carried out. The results were presented in two groups of patients with sudden and those of long lasting progressive unilateral deafness. Some of the patients were pharmacologically treated before the evaluation. It is concluded that the statistic analysis could be a basis for the management and prognosis of the unilateral deafness. PMID:11318476

  20. Atlas fractures

    Microsoft Academic Search

    S. Schären; B. Jeanneret

    1999-01-01

    Summary  \\u000a Fractures of the atlas account for 1–2 % of all vertebral fractures. We divide atlas fractures into 5 groups: isolated fractures\\u000a of the anterior arch of the atlas, isolated fractures of the posterior arch, combined fractures of the anterior and posterior\\u000a arch (so-called Jefferson fractures), isolated fractures of the lateral mass and fractures of the transverse process. Isolated\\u000a fractures

  1. Consequences of Unilateral Hearing Loss: Cortical Adjustment to Unilateral Deprivation

    PubMed Central

    Hutson, K.A.; Durham, D.; Imig, T.; Tucci, D.L.

    2008-01-01

    The effect of unilateral hearing loss on 2-deoxyglucose (2-DG) uptake in the central auditory system was studied in post-natal day 21 gerbils. Three weeks following a unilateral conductive hearing loss (CHL) or cochlear ablation (CA), animals were injected with 2-DG and exposed to an alternating auditory stimulus (1 and 2 kHz tones). Uptake of 2-DG was measured in the inferior colliculus (IC), medial geniculate (MG), and auditory cortex (fields AI and AAF) of both sides of the brain in experimental animals and in anesthesia-only sham animals (SH). Significant differences in uptake, compared to SH, were found in the IC contralateral to the manipulated ear (CHL or CA) and in AAF contralateral to the CHL ear. We hypothesize that these findings may result from loss of functional inhibition in the IC contralateral to CA, but not CHL. Altered states of inhibition at the IC may affect activity in pathways ascending to auditory cortex, and ultimately activity in auditory cortex itself. Altered levels of activity in auditory cortex may explain some auditory processing deficits experienced by individuals with CHL. PMID:18261867

  2. UNILATERAL RENAL DISEASE AND HYPERTENSION

    PubMed Central

    Burns, Edgar

    1953-01-01

    Cure is obtained in about 20 per cent of patients with unilateral renal disease and hypertension who have nephrectomy primarily for relief of hypertension. Carrying out urologic studies on a larger number of hypertensive patients might result in tracing the condition to renal disease in more cases. Renal angiography more accurately indicates renal origin of hypertension than any other diagnostic study. When it can reasonably be established that hypertension is of renal origin, nephrectomy should be performed unless there is some general contraindication to an operative procedure. PMID:13106723

  3. Prepubertal Unilateral Gynecomastia: Report of 2 Cases

    PubMed Central

    Demirbilek, Hüseyin; Bacak, Gökhan; Baran, R?za Taner; Avc?, Yahya; Baran, Ahmet; Kele?, Ay?enur; Özbek, Mehmet Nuri; Alanay, Yasemin; Hussain, Khalid

    2014-01-01

    Prepubertal unilateral gynecomastia is an extremely rare condition. At present, its etiology and management strategy are not well known. Two unrelated prepubertal boys of ages 8 and 9 who presented with complaints of unilateral enlargement of breast tissue are reported. Physical examination, biochemical, hormonal and oncologic work-up findings were normal. Both patients were treated with peripheral liposuction successfully. Histopathological and immunohistochemical examinations showed benign fibroglandular gynecomastia and intensive (3+) estrogen receptor expression in 100% of periductal epithelial cells. Although an extremely rare and generally benign condition, patients with prepubertal unilateral gynecomastia should have a full endocrine and oncologic work-up. PMID:25541897

  4. Unilateral Posterior Atlantoaxial Transarticular Screw Fixation in Patients with Atlantoaxial Instability : Comparison with Bilateral Method

    PubMed Central

    Hue, Yun Hee; Yi, Hyeong-Joong; Oh, Seong Hoon; Oh, Suck Jun; Ko, Yong

    2009-01-01

    Objective Bilateral C1-2 transarticular screw fixation (TAF) with interspinous wiring has been the best treatment for atlantoaxial instability (AAI). However, several factors may disturb satisfactory placement of bilateral screws. This study evaluates the usefulness of unilateral TAF when bilateral TAF is not available. Methods Between January 2003 and December 2007, TAF was performed in 54 patients with AAI. Preoperative studies including cervical x-ray, three dimensional computed tomogram, CT angiogram, and magnetic resonance image were checked. The atlanto-dental interval (ADI) was measured in preoperative period, immediate postoperatively, and postoperative 1, 3 and 6 months. Results Unilateral TAF was performed in 27 patients (50%). The causes of unilateral TAF were anomalous course of vertebral artery in 20 patients (74%), severe degenerative arthritis in 3 (11%), fracture of C1 in 2, hemangioblastoma in one, and screw malposition in one. The mean ADI in unilateral group was measured as 2.63 mm in immediate postoperatively, 2.61 mm in 1 month, 2.64 mm in 3 months and 2.61 mm in 6 months postoperatively. The mean ADI of bilateral group was also measured as following; 2.76 mm in immediate postoperative, 2.71 mm in 1 month, 2.73 mm in 3 months, 2.73 mm in 6 months postoperatively. Comparison of ADI measurement showed no significant difference in both groups, and moreover fusion rate was 100% in bilateral and 96.3% in unilateral group (p=0.317). Conclusion Even though bilateral TAF is best option for AAI in biomechanical perspectives, unilateral screw fixation also can be a useful alternative in otherwise dangerous or infeasible cases through bilateral screw placement. PMID:19352478

  5. Enoxaparin-induced unilateral hemotympanum.

    PubMed

    Aydin, Umit; Asik, M Burak; Gokgoz, M Cemal; Karakoc, Omer

    2015-07-01

    Hemotympanum is defined as the presence of blood in the middle ear cavity. It is commonly associated with skull fractures. Spontaneous hemotympanum secondary to anticoagulant therapy is extremely rare. Herein, we report the first case of a 51-year-old woman with right spontaneous hemotympanum related to the use of enoxaparin. Complete resolution of signs and symptoms was accomplished by conservative management. Close follow-up is important to assure resolution and reduce long-term sequelae. The use of anticoagulants should be considered in the differential diagnosis of hemotympanum. This is also a good case for clinicians to be mindful about hemorrhagic complications of anticoagulant treatment. PMID:25811446

  6. Outcomes following unilateral uterine artery embolisation.

    PubMed

    McLucas, B; Reed, R A; Goodwin, S; Rappaport, A; Adler, L; Perrella, R; Dalrymple, J

    2002-02-01

    Uterine artery embolisation has been described as successful only when both arteries are embolised. However, results in patients with one congenitally absent or previously ligated artery are unknown. Women suffering from symptomatic uterine myomata were treated at a university teaching hospital, a community hospital and an outpatient surgery centre. Retrospective review of patient response to embolisation was assessed by chart review and questionnaire. Uterine and dominant fibroid size response was assessed by comparing pre- and post-embolisation ultrasound examinations. This study analysed three patient groups within the general population: those who underwent unilateral embolisation because of technical failure, those who ultimately underwent bilateral embolisation after initial technical failure and those who underwent unilateral embolisation because of an absent uterine artery. 12 patients underwent unilateral embolisation, 4 of whom underwent this procedure because of an absent uterine artery. Three of these four patients had a congenitally absent uterine artery arising from the internal iliac artery and all three experienced successful outcomes. The fourth patient had a previously ligated internal iliac artery and her symptoms worsened after the procedure. Eight patients had unilateral embolisation due to technical failure. Five of these patients underwent a subsequent procedure during which the contralateral uterine artery was embolised. Four of these five patients had successful outcomes and one was lost to follow-up. Another of the eight patients suffered an arterial injury leading to technical failure, and was lost to follow-up. Of the two remaining patients with unilateral technical failure, only one had a successful outcome. This study concluded that patients who undergo unilateral embolisation for technical reasons should be offered a second embolisation procedure shortly after the initial procedure. Patients with a congenitally absent uterine artery may respond with similar success to those who underwent bilateral embolisation. In contrast, the patient with a previously ligated internal iliac artery failed. The numbers in this study are too small for statistical analysis and subsequent studies should be performed to confirm these findings. PMID:11893635

  7. Case report: unilateral mydriasis following nasal cautery.

    PubMed

    Koo Ng, Nigel K F; Calder, Nick

    2010-12-01

    We report a case of unilateral mydriasis following nasal electrocautery presumed to be the result of retrograde flow of adrenaline and/or xylometazoline hydrochloride (Otrivine) through the nasolacrimal duct into the eye. We review the literature and highlight the importance of correct interpretation of finding a dilated pupil post-operatively. To our knowledge. we report the first such case involving xylometazoline hydrochloride and also following nasal electrocautery. Unilateral mydriasis is alarming after nasal surgery but must be interpreted with caution. During minimally invasive procedures it is likely to be due to the effects of topical medication to the nose rather than surgical trauma. PMID:21158576

  8. Asymmetric and unilateral hearing loss in children.

    PubMed

    Vila, Peter M; Lieu, Judith E C

    2015-07-01

    Asymmetric and unilateral hearing losses in children have traditionally been underappreciated, but health care practitioners are now beginning to understand their effect on development and the underlying pathophysiologic mechanisms. The common wisdom among medical and educational professionals has been that at least one normal-hearing or near-normal-hearing ear was sufficient for typical speech and language development in children. The objective of this review is to illustrate, to the non-otolaryngologist, the consequences of asymmetric and unilateral hearing loss in children on developmental and educational outcomes. Etiology, detection, and management are also discussed. Lastly, implications for further research are considered. PMID:26004144

  9. Penile fracture repair: assessment of early results and complications using color Doppler ultrasound

    Microsoft Academic Search

    P Gontero; PS Sidhu; GH Muir

    2000-01-01

    The aim of this study was to determine early results and complications of penile fracture treated with immediate surgical repair by means of color Doppler ultrasound study. Four patients with the clinical features of penile fracture were submitted to immediate surgical exploration via a subcoronal incision with repair of the torn cavernosal albuginea (unilateral in three cases, bilateral in one

  10. Contralateral Ureteral Meatal Advancement in Unilateral Antireflux Surgery

    Microsoft Academic Search

    Paolo Caione; Nicola Capozza; Alberto Lais; Simona Nappo; Ennio Matarazzo; Fabio Ferro

    1997-01-01

    PurposeContralateral vesicoureteral reflux is a well-known development after successful unilateral ureteral reimplantation that is not apparently influenced by the reimplantation technique. We sought to determine whether bilateral reimplantation should be performed routinely in unilateral cases.

  11. Unilateral pulmonary artery agenesis with vertebral anomaly

    PubMed Central

    Prasad, Rajniti; Srivastava, G N; Mishra, O P; Singh, Utpal Kant

    2013-01-01

    We report a two-and-half–year-old boy who presented with recurrent respiratory tract infections. He had cortriatum of right atrium, spina bifida occulta, hemivertebra and dysplastic right thumb. On CT of chest, he had also unilateral pulmonary artery agenesis. The case is being reported because of common manifestations of rare disease and its associated cardiac and skeletal abnormalities. PMID:23784756

  12. Unilateral vs. Bilateral Damage 1 Running head: UNILATERAL VS. BILATERAL DAMAGE

    E-print Network

    McClelland, James L. "Jay"

    Scoville produced a profound memory loss in patient HM by removing the hippocampus bilaterally. Scoville, 1955; Scoville & Milner, 2000). Why are there such different consequences of unilateral and bilateral

  13. Mandibular fracture patterns consistent with posterior maxillary fractures involving the posterior maxillary sinus, pterygoid plate or both: CT characteristics

    PubMed Central

    Sukegawa, S; Kanno, T; Fujita, G; Yamamoto, N; Furuki, Y; Michizawa, M

    2014-01-01

    Objectives: The aim of this study was to determine the incidence of posterior maxillary fractures involving the posterior maxillary sinus wall, pterygoid plate or both, unrelated to major midface fractures in patients with mandibular fractures, and to characterize associated fractures. Methods: A CT study was performed in patients with mandibular fractures to identify posterior maxillary fractures. Patients aged under 16 years, those with mandibular fractures involving only dentoalveolar components and those with concurrent major midfacial fractures were excluded. Results: 13 (6.7%) of 194 patients with mandibular fractures also had posterior maxillary fractures (case group). The injury pattern correlated with the external force directed to the lateral side of the mandible (p?fractures (p?=?0.002) and the fracture regions in the symphysis/parasymphysis (p?=?0.001) and the angle/ramus (p?=?0.001). No significant difference between the case and non-case groups was seen for age, sex or cause of trauma. Non-displaced fractures in the ipsilateral posterior mandible occurred with significant frequency (p?=?0.001) when the posterior maxillary fractures involved only the sinus. Conclusions: Mandibular fractures accompanied by posterior maxillary fractures are not rare. The finding of a unilateral posterior maxillary fracture on CT may aid the efficient radiological examination of the mandible based on possible patterns of associated fractures, as follows: in the ipsilateral posterior region as a direct fracture when the impact is a medially directed force, and in the symphysis/parasymphysis or contralateral condylar neck as an indirect fracture. PMID:24336313

  14. Lisfranc’s dislocation and fracture in the Charcot Foot

    Microsoft Academic Search

    Nauman Bashir Barlas; Muhammad Ali; Sajjad Hussain

    2009-01-01

    Diabetic patients may present with Lisfranc’s Fracture Dislocation which may be confused with osteomyelitis. Rapid diagnosis and early intervention can prevent deformity. We suggest that the diagnosis of Charcot’s foot should be considered in any diabetic patient with unilateral swelling of lower extremity and\\/or foot.

  15. Unilateral Punctate Keratitis Secondary to Wallenberg Syndrome

    PubMed Central

    Boto, Ana; Del Hierro, Almudena; Capote, Maria; Noval, Susana; Garcia, Amanda; Santiago, Susana

    2014-01-01

    We studied three patients who developed left unilateral punctate keratitis after suffering left-sided Wallenberg Syndrome. A complex evolution occurred in two of them. In all cases, neurophysiological studies showed damage in the trigeminal sensory component at the bulbar level. Corneal involvement secondary to Wallenberg syndrome is a rare cause of unilateral superficial punctate keratitis. The loss of corneal sensitivity caused by trigeminal neuropathy leads to epithelial erosions that are frequently unobserved by the patient, resulting in a high risk of corneal-ulcer development with the possibility of superinfection. Neurophysiological studies can help to locate the anatomical level of damage at the ophthalmic branch of the trigeminal nerve, confirming the suspected etiology of stroke, and demonstrating that prior vascular involvement coincides with the location of trigeminal nerve damage. In some of these patients, oculofacial pain is a distinctive feature. PMID:24882965

  16. Smell sparing unilateral intracranial dermoid resection.

    PubMed

    Grayson, Jessica W; Chaaban, Mohamad R; Riley, Kristen O; Woodworth, Bradford A

    2014-03-01

    Intracranial dermoid cysts are congenital ectodermal inclusion cysts that have a propensity to occur in the midline sellar, parasellar, or frontonasal regions. These cysts enlarge by means of glandular secretion and epithelial desquamation. Surgical resection has traditionally included a craniotomy, but endoscopic approaches are now used with increasing regularity. A binostril approach is normally used to access dermoid cysts due to the midline nature of the lesions. In this case report, we describe the successful surgical resection of a dermoid with 1.5-cm of intracranial extension using a unilateral endonasal endoscopic approach with no complications and with no postoperative anosmia. Although the unilateral endoscopic technique is not plausible for all epidermoid or dermoid cysts of the anterior cranial fossa, it should be considered a viable alternative technique when faced with a dermoid limited to one side of the falx cerebri. PMID:24612984

  17. Smell sparing unilateral intracranial dermoid resection

    PubMed Central

    Grayson, Jessica W.; Chaaban, Mohamad R.; Riley, Kristen O.

    2014-01-01

    Intracranial dermoid cysts are congenital ectodermal inclusion cysts that have a propensity to occur in the midline sellar, parasellar, or frontonasal regions. These cysts enlarge by means of glandular secretion and epithelial desquamation. Surgical resection has traditionally included a craniotomy, but endoscopic approaches are now used with increasing regularity. A binostril approach is normally used to access dermoid cysts due to the midline nature of the lesions. In this case report, we describe the successful surgical resection of a dermoid with 1.5-cm of intracranial extension using a unilateral endonasal endoscopic approach with no complications and with no postoperative anosmia. Although the unilateral endoscopic technique is not plausible for all epidermoid or dermoid cysts of the anterior cranial fossa, it should be considered a viable alternative technique when faced with a dermoid limited to one side of the falx cerebri. PMID:24612984

  18. [Unilateral nasal obstruction in children: Pai syndrome].

    PubMed

    Zanetta, Adrián; Cuestas, Giselle; Oviedo, Maricruz; Tiscorni, Carlos

    2011-10-01

    Unilateral obstruction of the nasal cavity in children is mainly caused by the introduction of foreign bodies further stated with rhinorrhea and fetid odor. Less commonly, it can be traumatic, neoplastic, due to congenital malformation or iatrogenic. Symptoms of congenital intranasal mass may present at birth, or go unnoticed and be a finding in a routine pediatric examination. Patient evaluation should include imaging studies to guide the diagnosis and rule out intracranial extension. A syndrome associated with congenital nasal tumor should be suspected when other abnormalities are present. Pai syndrome is a rare genetic disorder. Its manifestations are craniofacial being congenital nasal polyp his main marker. We present a patient with unilateral nasal respiratory failure secondary to congenital nasal lipoma, with craniofacial anomalies belonging to Pai syndrome. Nasal obstruction was successfully surgically resolved. PMID:22042063

  19. Spontaneous unilateral brainstem infarction in Swiss mice.

    PubMed

    Southard, T; Brayton, C F

    2011-05-01

    Spontaneous vestibular syndrome in mice, characterized clinically by head tilt, circling or rolling, can be caused by otitis media, arteritis or central nervous system lesions. Postmortem examination of eleven non-inbred Swiss mice submitted for necropsy due to acute onset of vestibular signs revealed lesions consistent with brainstem infarction. The lesions were characterized by unilateral, well-demarcated areas of necrosis, malacia, and gliosis, with variable amounts of hemorrhage, in the lateral aspect of the medulla and caudal pons. The affected area included the medial, lateral and superior vestibular nuclei, the facial nucleus and the spinal trigeminal nucleus. While vestibular disease secondary to otitis media, periarteritis, and central nervous system neoplasia has been reported in many mouse strains, these unilateral brainstem infarctions were only seen in Swiss mice. These lesions share features with Wallenberg's Lateral Medullary Syndrome, the most common type of brainstem infarct in humans. PMID:20466861

  20. Malignant seminoma in two unilaterally cryptorchid stallions.

    PubMed

    De Lange, V; Chiers, K; Lefère, L; Cools, M; Ververs, C; Govaere, J

    2015-06-01

    Two unilateral cryptorchid stallions were referred to the clinic because of chronic debilitating condition with emaciation. Rectal examination, and ultrasound and gross examination revealed in both animals an abdominal mass, caudally of the kidney, and multiple nodules spread over the abdomen. Histologic analysis revealed an intra-abdominal malignant seminoma with intraperitoneal and renal metastasis. Interestingly, a seminoma was also present in the descended testis of the draught horse. PMID:25759202

  1. [Hip fractures].

    PubMed

    Weisová, Drahomíra; Salášek, Martin; Pavelka, Tomáš

    2013-01-01

    Hip fractures are ranked among the frequent injuries. These fractures have been often coupled with high energy trauma in children and in patients with normal bone structure, low energy trauma and osteoporotic fracture (fragility fracture) is typical in elder patients. Hip fractures are divided into five groups: femoral head fracture, femoral neck fracture, pertrochanteric, intertrochateric and subtrochanteric fracture. Surgical treatment is indicated in all patients unless contraindications are present. Long bed rest has been accompanied by a high risk of development of thromboembolic disease, pneumonia and bed sore. Healing in the wrong position and nonunions are often the result of conservative treatment. Screw osteosynthesis is performed in isolated femoral head factures. Three cannulated screws or a DHS plate (dynamic hip screw) are used in fractures of the femoral neck with normal femoral head perfusion, total hip replacement is recommended in elder patients and in case of loss of blood supply of the femoral head. Pertrochanteric and intertrochanteric fractures can be stabilized by the femoral nails (PFN, PFN A, PFH - proximal femoral nail), nails are suitable for minimally invasive insertion and provide higher stability in the shaft, or plates (DHS) designed for stable pertronchanteric and intertrochanteric fractures. Subtrochanteric fractures can be fixed also intramedullary (nails - PFN long, PFN A long) and extramedullary (plates - DCS dynamic condylar screw, proximal femoral LCP - locking compression plate). Open reduction with internal plate fixation is advantageous for pathological fractures, as biopsy sampling can be performed. Hip fracture rehabilitation is integral part of the treatment, including walking on crutches or with a walker with partial weight bearing for at least six weeks. PMID:24131459

  2. Simultaneous Bilateral or Unilateral Carpal Tunnel Release?

    PubMed Central

    Osei, Daniel A.; Calfee, Ryan P.; Stepan, Jeffrey G.; Boyer, Martin I.; Goldfarb, Charles A.; Gelberman, Richard H.

    2014-01-01

    Background: Over 60% of patients with carpal tunnel syndrome present with symptoms and findings of nerve compression in both hands. Our goal was to compare patient-rated difficulties in performing activities of daily living in the early postoperative period between those undergoing bilateral carpal tunnel release and those undergoing unilateral carpal tunnel release. Methods: This prospective cohort study enrolled consecutive patients with bilateral carpal tunnel syndrome undergoing bilateral carpal tunnel release (n = 47) or unilateral carpal tunnel release (n = 41). Patient function and disease severity were measured by an abbreviated form of the Disabilities of the Arm, Shoulder and Hand questionnaire, QuickDASH, and the Boston Carpal Tunnel Questionnaire at baseline, at postoperative visit 1 at a mean time (and standard deviation) of 10 ± 3 days, and at postoperative visit 2 at a mean time (and standard deviation) of 30 ± 6 days. Patients rated their difficulty in completing fifteen activities of daily living each day for the first postoperative week. Patients reported the factors that influenced their choice of surgery. Results: There was no difference in baseline function or disease severity between the two groups with regard to QuickDASH and the Boston Carpal Tunnel Questionnaire. Patients in both groups improved after carpal tunnel release with no difference between groups either at postoperative visit 1 for QuickDASH (p = 0.97) and the Boston Carpal Tunnel Questionnaire (p = 0.86) or at postoperative visit 2 for QuickDASH (p = 0.43) and the Boston Carpal Tunnel Questionnaire (p = 0.34). Patients undergoing bilateral carpal tunnel release had more difficulty only during postoperative days 1 to 2 in opening jars (p = 0.03), cooking (p = 0.008), and doing household chores (p = 0.02). Patients in the two groups did not differ (p > 0.05) in their abilities to perform activities of daily living necessary for personal hygiene or independence on any day during the first seven days following surgery with regard to using the bathroom, bathing, dressing, or eating. Although the most common reason why patients chose bilateral carpal tunnel release was to avoid two surgical procedures (42%), the most common reason why patients chose unilateral carpal tunnel release was concern for self-care (36%). Conclusions: Patients with bilateral carpal tunnel syndrome can anticipate more severe functional impairment during the first few postoperative days with bilateral carpal tunnel release compared with unilateral carpal tunnel release, but limitations beyond postoperative day 2 or 3 are similar for bilateral and unilateral carpal tunnel release. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence. PMID:24897736

  3. Efficacy analysis of pedicle screw internal fixation of fractured vertebrae in the treatment of thoracolumbar fractures.

    PubMed

    Huang, Weijie; Luo, Tao

    2013-03-01

    The present study aimed to discuss the method and effect of posterior internal fixation of thoracolumbar fractures strengthened by the vertical stress pedicle screw fixation of fractured vertebrae. Patients with single thoracolumbar fractures were examined retrospectively. Fourteen patients (group A) had been treated with vertical stress pedicle screw fixation of a fractured vertebra and sixteen patients (group B) received traditional double-plate fixation, as a control. All patients were diagnosed with fresh fractures with a complete unilateral or bilateral pedicle and no explosion of the inferior half of the vertebral body or inferior endplate. In group A, patients received conventional posterior distraction and lumbar lordosis restoration, as well as pedicle screws in the fractured vertebra in a vertical direction to relieve stress to achieve a local stress balance. All patients were followed up postoperatively for 4-18 months (average, 12.6 months). The vertical stress pedicle screw fixation assisted in the reduction of vertebrae fracture, which reduced the postoperative Cobb's angle loss. There was a significant difference in the change of Cobb's angle between the two groups one year after surgery (P<0.01). Conditional application of pedicle screws in a single thoracolumbar fracture enhances the stability of the internal fixation system and is conducive to the correction of kyphosis and maintenance of the corrective effects. PMID:23407593

  4. Unilateral hearing loss following shunt placement for normal pressure hydrocephalus with a unilateral patent cochlear aqueduct

    Microsoft Academic Search

    Sun-Ho Lee; Seong-Hyun Park; Sung-Kyoo Hwang

    2007-01-01

    Hearing loss in patients who have undergone shunt placement for a hydrocephalus is perhaps an underestimated complication rather than a rare event. There appears to be a correlation between the occurrence of hearing loss and patient characteristics consistent with excessive drainage of cerebrospinal fluid (CSF) and patent cochlear aqueduct (CA). We present the case of a 77-year-old man with unilateral

  5. Temporal Bone Fracture Causing Superior Semicircular Canal Dehiscence

    PubMed Central

    Peng, Kevin A.; Yang, Isaac; Gopen, Quinton

    2014-01-01

    Importance. Superior semicircular canal dehiscence (SCD) is a third window lesion of the inner ear causing symptoms of vertigo, autophony, tinnitus, and hearing loss. A “two-hit” hypothesis has traditionally been proposed, whereby thinly developed bone overlying the superior canal is disrupted by a sudden change in intracranial pressure. Although the symptoms of SCD may be precipitated by head injury, no previous reports have described a temporal bone fracture directly causing SCD. Observations. Two patients sustained temporal bone fractures after closed head trauma, and developed unilateral otologic symptoms consistent with SCD. In each instance, computed tomography imaging revealed fractures extending through the bony roof of the superior semicircular canal. Conclusions and Relevance. Temporal bone fractures, which are largely treated nonoperatively, have not previously been reported to cause SCD. As it is a potentially treatable entity, SCD resulting from temporal bone fracture must be recognized as a possibility and diagnosed promptly if present. PMID:25295207

  6. Molecular Karyotype of Sporadic Unilateral Retinoblastoma Tumors

    PubMed Central

    Ganguly, Arupa; Nichols, Kim E.; Grant, Gregory; Rappaport, Eric; Shields, Carol

    2009-01-01

    Background Retinoblastoma (RB) is a childhood ocular malignancy associated with mutations in RB1, a tumor susceptibility gene. Inactivation of both copies of the RB1 gene in a retinal cell is followed by the sequential acquisition of additional genetic changes that define the course to tumor formation. Methods To identify the genetic events that cooperate with loss of the RB1 gene function, we performed a whole genome sampling assay (WGSA) based on SNP genotyping. We used DNA isolated from 25 sporadic, unilateral RB tumors and matched blood samples. Results Genomic profiles were analyzed to identify regions of loss of heterozygosity (LOH) and/or amplification. Two major subclasses of RB tumors were defined by the presence (n=18) or absence (n=7) of LOH of chromosome 13. LOH in most cases was due to copy neutral events caused by mitotic recombination and mitotic non-disjunction. Tumors harbored novel regions of amplification at 1q44, 3p25, 11q14, 11q25, 14q23, 15q21, 16p13, 17p11.2, 19q13, and 20q13 while regions of loss included 6q22, 7q21and 21q2. Conclusion WGSA-based analysis of unilateral RB tumors revealed novel regions as significant. These minimum critical regions that are lost or amplified are expected to harbor genes that aid the process of tumorigenesis. PMID:19491728

  7. Unilateral diaphragmatic dysfunction in blunt chest trauma.

    PubMed

    Gastinne, H; Venot, J; Dupuy, J P; Gay, R

    1988-03-01

    This study was undertaken to evaluate unilateral diaphragmatic dysfunction within ten days after blunt chest trauma. Thirty patients with unilateral chest injury, or predominantly one-sided injuries, were investigated in the supine position, under analgesia. Right and left hemidiaphragm displacement (DD) was measured, using digital subtraction radiography, during quiet and forced breathing. The diaphragmatic contribution to breathing was determined by rib cage and abdominal circumference measurement changes. In both breathing modes, DD of the injured side was lower than DD of the uninjured side (p less than 0.01, p less than 0.001). Six patients had complete diaphragmatic motionlessness. The inspired air volume due to diaphragmatic motion (Vab) was reduced when compared to normal subjects and Vab/VT ratio was always found to be less than 0.65. The degree of diaphragmatic dysfunction appeared related to injury location and is most severe in injuries of the lower chest which implies direct diaphragm muscle injury, although other mechanisms may be implicated. Diaphragmatic dysfunction can contribute to respiratory failure in these patients, and should be considered. PMID:3277805

  8. Hypertropia in unilateral isolated abducens palsy

    PubMed Central

    Pihlblad, Matthew S.; Demer, Joseph L.

    2014-01-01

    Purpose To evaluate the incidence and features of hypertropia in abducens nerve palsy. Methods The records of consecutive patients with unilateral, isolated, previously unoperated abducens nerve palsy were reviewed for binocular alignment on cover testing, Krimsky measurement, or Hess screen testing. Patients with associated cranial nerve palsy (including bilateral abducens palsies), orbital disease, myasthenia gravis, Horner syndrome, hemiplegia, cerebellar signs, arteritis, or previous strabismus surgery were excluded. Control subjects underwent complete examination to confirm normality. Results A total of 79 patients were included (40 males; mean age 49.2 years). Hypertropia in lateral or central gazes was present in 15 of 79 cases (19%) on alternate cover or Krimsky testing, in 32 of 56 cases (57%) on Hess screen testing, and absent in all 30 normal controls. Of cases with hypertropia, the mean of the greatest hypertropia in lateral or central gaze on was 5.0? ± 2.3? (standard deviation; range, 1?–8?) routine clinical examination, and 5.8? ± 4.2? (range, 2?–24?) on Hess screen testing. Of 39 cases with partial abducens palsy evaluated by Hess screen testing, the ipsilesional eye was hypertropic in 24 (61%) and hypotropic in 15 cases (39%). Conclusions Small-angle hypertropia is common in isolated, unilateral abducens and does not necessarily imply existence of multiple cranial neuropathies or skew deviation. PMID:24924275

  9. Unilateral choanal atresia: initial presentation and endoscopic repair

    Microsoft Academic Search

    Brian J. Wiatrak

    1998-01-01

    The purpose of this study was to investigate the severity of presenting symptomatology in patients with unilateral choanal atresia and to assess the surgical results of patients undergoing transnasal endoscopic repair. A retrospective review of all patients with choanal atresia presenting to the author between 1990 and 1997 was performed, identifying 13 patients with unilateral choanal atresia. These patients were

  10. Postural fluctuations during pointing from a unilateral or bilateral stance

    Microsoft Academic Search

    Ing-Shiou Hwang; Chien-Ting Huang; Rong-Ju Cherng; Chien-Chun Huang

    2006-01-01

    An experiment was conducted to compare the effects of bilateral and unilateral stance on postural fluctuations and intralimb coordination during active balance control. Fifteen participants stood bilaterally and unilaterally while conducting a pointing task with an outstretched arm. Excursion of center of foot pressure (CoP) and limb movements were recorded with a force plate and eight dual-axis accelerometers, respectively. Compared

  11. Bilateral Effects of Unilateral Cochlear Implantation in Congenitally Deaf Cats

    E-print Network

    Ryugo, David K.

    Bilateral Effects of Unilateral Cochlear Implantation in Congenitally Deaf Cats Jahn N. O'Neil,1 system via cochlear implants would restore the endbulb synapses to their normal morphology. Three and 6-month-old con- genitally deaf cats received unilateral cochlear implants and were stimulated

  12. Should lung volume reduction for emphysema be unilateral or bilateral?

    Microsoft Academic Search

    Robert J. McKenna; Matthew Brenner; Richard J. Fischel; Arthur F. Gelb

    1996-01-01

    Both unilateral and bilateral lung volume reduction procedures are being advocated for treatment of severe, generalized emphysema. We analyzed the results of 166 consecutive patients who underwent unilateral (n = 87) or bilateral (n = 79) thoracoscopic stapled lung volume reductions to help define the role for these procedures. There was no statistically significant difference in the operative mortality (3.5%

  13. GENERALIZATION OF USUAL CAPABILITY INDICES FOR UNILATERAL DANIEL GRAU

    E-print Network

    Boyer, Edmond

    of the usual family. Key words: Process Capability Indices, Unilateral Tolerances, Non-normal Processes. 1 target value T. Accordingly, the capability indices used to measure the quality of the process are linkedGENERALIZATION OF USUAL CAPABILITY INDICES FOR UNILATERAL TOLERANCES DANIEL GRAU Laboratory

  14. Reproducibility of Tactile Assessments for Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Auld, Megan Louise; Ware, Robert S.; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2012-01-01

    A systematic review identified tactile assessments used in children with cerebral palsy (CP), but their reproducibility is unknown. Sixteen children with unilateral CP and 31 typically developing children (TDC) were assessed 2-4 weeks apart. Test-retest percent agreements within one point for children with unilateral CP (and TDC) were…

  15. Neuromuscular fatigue differs following unilateral vs bilateral sustained submaximal

    E-print Network

    Paris-Sud XI, Université de

    Neuromuscular fatigue differs following unilateral vs bilateral sustained submaximal contractions 1 of Medicine & Science in Sports Volume 21, Issue 2, pages 268­276, April 2011 Additional Information(Show All. and Lepers, R. (2011), Neuromuscular fatigue differs following unilateral vs bilateral sustained submaximal

  16. Hydraulic fracturing in a naturally fractured reservoir

    SciTech Connect

    Britt, L.K.; Hager, C.J.; Thompson, J.W.

    1994-12-31

    Hydraulic fracturing of wells in naturally fractured reservoirs can differ dramatically from fracturing wells in conventional isotropic reservoirs. Fluid leakoff is the primary difference. In conventional reservoirs, fluid leakoff is controlled by reservoir matrix and fracture fluid parameters. The fluid leakoff rate in naturally fractured reservoirs is typically excessive and completely dominated by the natural fractures. This paper presents several field examples of a fracture stimulation program performed on the naturally fractured Devonia carbonate of West Texas. Qualitative pressure decline analysis and net treating pressure interpretation techniques were utilized to evaluate the existence of natural fractures in the Devonian Formation. Quantitative techniques were utilized to assess the importance of the natural fractures to the fracturing process. This paper demonstrates that bottomhole pressure monitoring of fracture stimulations has benefits over conducting minifrac treatments in naturally fractured reservoirs. Finally, the results of this evaluation were used to redesign fracture treatments to ensure maximum productivity and minimize costs.

  17. Evaluation of unilateral cage-instrumented fixation for lumbar spine

    PubMed Central

    2010-01-01

    Background To investigate how unilateral cage-instrumented posterior lumbar interbody fusion (PLIF) affects the three-dimensional flexibility in degenerative disc disease by comparing the biomechanical characteristics of unilateral and bilateral cage-instrumented PLIF. Methods Twelve motion segments in sheep lumbar spine specimens were tested for flexion, extension, axial rotation, and lateral bending by nondestructive flexibility test method using a nonconstrained testing apparatus. The specimens were divided into two equal groups. Group 1 received unilateral procedures while group 2 received bilateral procedures. Laminectomy, facectomy, discectomy, cage insertion and transpedicle screw insertion were performed sequentially after testing the intact status. Changes in range of motion (ROM) and neutral zone (NZ) were compared between unilateral and bilateral cage-instrumented PLIF. Results Both ROM and NZ, unilateral cage-instrumented PLIF and bilateral cage-instrumented PLIF, transpedicle screw insertion procedure did not revealed a significant difference between flexion-extension, lateral bending and axial rotation direction except the ROM in the axial rotation. The bilateral group's ROM (-1.7 ± 0. 8) of axial rotation was decreased significantly after transpedicle screw insertion procedure in comparison with the unilateral group (-0.2 ± 0.1). In the unilateral cage-instrumented PLIF group, the transpedicle screw insertion procedure did not demonstrate a significant difference between right and left side in the lateral bending and axial rotation direction. Conclusions Based on the results of this study, unilateral cage-instrumented PLIF and bilateral cage-instrumented PLIF have similar stability after transpedicle screw fixation in the sheep spine model. The unilateral approach can substantially reduce exposure requirements. It also offers the biomechanics advantage of construction using anterior column support combined with pedicle screws just as the bilateral cage-instrumented group. The unpleasant effect of couple motion resulting from inherent asymmetry was absent in the unilateral group. PMID:21070626

  18. Congenital unilateral fibrosis, blepharoptosis, and enophthalmos syndrome.

    PubMed

    Hertle, R W; Katowitz, J A; Young, T L; Quinn, G E; Farber, M G

    1992-03-01

    The authors report four cases of the rarest form of the congenital fibrosis syndrome. This disorder is exhibited in infancy as unilateral blepharoptosis, strabismus, limited ductions, globe displacement (enophthalmos and blepharoptosis), and decreased vision, usually due to amblyopia. Forced ductions are positive and surgical exploration confirms anomalous muscle structure. Computed tomography and magnetic resonance imaging studies in these four patients were diagnostically beneficial, showing extraocular muscle and tendinous insertion involvement, and poorly defined intraconal and extraconal masses that had the appearance of scar or inflammatory tissue. All patients had globe displacement. The opposite eye and intracranial contents were normal in all of our patients. Results of histopathologic examination obtained at surgery in three of these patients show replacement of affected structures by fibrous tissue and included the extraocular muscles, orbital fat, Tenon's capsule, and conjunctiva. PMID:1565446

  19. Spontaneous Idiopathic Unilateral Adrenal Haemorrhage (SIAH).

    PubMed

    Naqvi, Syed Ali; Zaman, Shamas; Ahmed, Irfan

    2015-04-01

    Spontaneous Idiopathic Adrenal Haemorrhage (SIAH) is an unusual surgical emergency which can present with life threatening massive retroperitoneal bleeding. Most of the cases reported in the literature are associated with use of anticoagulation or underlying adrenal pathology such as tumors or cysts. Since this clinical entity is uncommon and clinical presentation is very indistinct, the diagnosis can be easily missed and can be challenging for the treating physicians. Nevertheless a raised clinical suspicion coupled with advances in radiological imaging have considerably improved the detection of SIAH in recent times. We report an unusual case of a 20 years old healthy female student who presented to our hospital with sudden onset of abdominal pain and shock. She was diagnosed as a case of massive spontaneous idiopathic unilateral adrenal haemorrhage, unaccompanied by any hematologic disorder, trauma or underlying pathology. Although patient was hemodynamically unstable at presentation, she was resuscitated promptly, investigated appropriately, hence recovered uneventfully with conservative management alone. PMID:25933454

  20. Unilateral corneal leukoplakia without limbal involvement

    PubMed Central

    Hirano, Koji; Koide, Mihoko; Mizoguchi, Yoshikazu; Osakabe, Yasuhiro; Sasaki, Kaoru-Araki

    2015-01-01

    Purpose Leukoplakia is the term given to a white patch or plaque that is found mainly on the oral mucus membrane. It can occasionally be seen on the corneal surface. We report our clinical and histopathological findings in a case of unilateral corneal leukoplakia. Methods A 26-year-old woman was referred to our hospital because of a white patch on her right cornea that continued to expand. She first noticed the white patch when she was 20 years old, and the white patch had expanded to cover the pupillary area affecting her vision. After plastic surgery on both eyelids for bilateral entropion to alleviate the pain caused by the eyelashes rubbing the cornea, the white corneal patch decreased in size. Because of this reduction, we performed surgery to remove the patch with microforceps under topical anesthesia. The plaque was removed easily and completely, and submitted for histopathological examination. Results Histopathological examination showed that the specimen had characteristics of epidermis with a basal cell layer, spinous cell layer, granular cell layer, and horny layer with hyperkeratosis. She was diagnosed with leukoplakia of the corneal surface. The basic structure of the squamous cell layer was preserved, and there were no signs of metaplasia. Six months after the removal of the leukoplakia, no recurrence was seen and her corrected decimal visual acuity recovered to 1.0. Conclusion Our case of unilateral corneal leukoplakia without limbal involvement was most likely caused by chronic irritation of the cornea by the eyelashes. Although it was totally removed with good recovery of vision, we continue to follow the patient because of the potential of malignant transformation. PMID:26056494

  1. Unilateral versus Bilateral Instrumentation in Spinal Surgery: A Systematic Review

    PubMed Central

    Molinari, Robert W.; Saleh, Ahmed; Molinari, Robert; Hermsmeyer, Jeff; Dettori, Joseph R.

    2015-01-01

    Study Design?Systematic review. Clinical Questions?(1) What is the comparative efficacy of unilateral instrumentation compared with bilateral instrumentation in spine surgery? (2) What is the safety of unilateral instrumentation compared with bilateral instrumentation in spine surgery? Methods?Electronic databases and reference lists of key articles were searched up to September 30, 2014, to identify studies reporting the comparative efficacy and safety of unilateral versus bilateral instrumentation in spine surgery. Studies including recombinant human bone morphogenetic protein 2 as adjunct therapy and those with follow-up of less than 2 years were excluded. Results?Ten randomized controlled trials met the inclusion criteria: five compared unilateral with bilateral instrumentation using open transforaminal or posterior lumbar interbody fusion (TLIF/PLIF), one used open posterolateral fusion, and four used minimally invasive TLIF/PLIF. There were no significant differences between unilateral and bilateral screw instrumentation with respect to nonunion, low back or leg pain scores, Oswestry Disability Index, reoperation, or complications. Conclusions?The existing literature does not identify significant differences in clinical outcomes, union rates, and complications when unilateral instrumentation is used for degenerative pathologic conditions in the lumbar spine. The majority of published reports involve single-level lumbar unilateral instrumentation.

  2. An interesting radiological picture of post traumatic TMJ ankylosis due to sagittal condylar fracture

    PubMed Central

    Kumar L.K., Surej; Manuel, Suvy; Kurien, Nikhil M.; Khalam, Sherin A.; P. Menon, Varun

    2015-01-01

    Introduction In a condylar fracture whether to intervene or to go for conservative management still remains a dilemma. Studies and hypothesis suggests that it's medially dislocated condylar fracture segment that is more likely to ankylose, moreover no consensus have been put forth as to whether to remove the medially displaced fracture segment. Presentation of case The current article describes a case of unilateral temporomandibular joint (TMJ) ankylosis, which resulted as a sequlae from conservative management of a bilateral condylar fracture of which, the ankylosed side had a sagittal fracture of condyle. In our case the post trauma CT shows the lateral segment abutting with the arch and that the area has become ankylotic in a span of 2 years. Here we report a case of posttraumatic unilateral TMJ ankylosis resulting from closed reduction of a bilateral condylar fracture with interesting radiological findings. Discussion We have tried to discuss a rather interesting radiological picture of posttraumatic TMJ ankylosis which resulted as a sequlae from conservative management of a bilateral condylar fracture. Conclusion The dilemma for a clinician as to whether to intervene in a condylar fracture or to go for conservative management still remains at large. As in this case the medial fracture segment was intact and the lateral segment was resulting in ankylosis. PMID:25985295

  3. Unilateral pupillary dilatation following septoplasty: cause for concern?

    PubMed

    Shakeel, Muhammad; Trinidade, Aaron; Khan, Imran; Johnston, Graham; Hussain, Akhtar

    2013-07-01

    We report and explain unilateral pupillary dilatation following routine septoplasty and trimming of inferior turbinates. The unilateral pupillary dilatation was caused by inadvertent instillation of sympathomimetic, (xylometazoline hydrochloride) in the eye during preparation for nasal surgery. The effect was short-lived and the patient made a full recovery. Unilateral pupillary dilatation after sinonasal surgery can be alarming due to the possibility of injury to the globe and intracranial haemorrhage but can also be explained by the mydriatic effect of the sympathomimetic nasal drops and sprays used to decongest the nose. Such possibility should be borne in mind and would help to explain and reduce the anxiety and avoid unnecessary investigations. PMID:23823962

  4. Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients

    PubMed Central

    Wit, H. P.

    2010-01-01

    Vestibular evoked myogenic potentials (VEMPs) were measured in 22 unilateral Menière patients with monaural and binaural stimulation with 250 and 500 Hz tone bursts. For all measurement situations significantly lower VEMP amplitudes were on average measured at the affected side compared to the unaffected side. Unilateral Menière patients have, in contrast to normal subjects, asymmetric VEMPs, indicating a permanently affected vestibular (most likely otolith) system at the side of hearing loss. The diagnostic value of VEMP amplitude asymmetry measurement in individual patients is low, because of the large overlap of the VEMP amplitude asymmetry range for unilateral Menière patients with that for normal subjects. PMID:20665043

  5. Unilateral Altruism in Network Routing Games with Atomic Players Amar Prakash Azad John Musacchio

    E-print Network

    Paris-Sud XI, Université de

    Unilateral Altruism in Network Routing Games with Atomic Players Amar Prakash Azad John Musacchio of Unilateral Altruism (VoU) to be the ratio of the equilibrium utility of the altruistic user of unilateral altruism. We find by way of example that the effect of unilateral altruism can be arbitrarily

  6. Unilateral Altruism in Network Routing Games with Atomic Players Amar Prakash Azad John Musacchio

    E-print Network

    Boyer, Edmond

    1 Unilateral Altruism in Network Routing Games with Atomic Players Amar Prakash Azad John Musacchio of Unilateral Altruism (VoU) to be the ratio of the equilibrium utility of the altruistic user of unilateral altruism. We find by way of example that the effect of unilateral altruism can be arbitrarily

  7. Comparison between Bilateral C2 Pedicle Screwing and Unilateral C2 Pedicle Screwing, Combined with Contralateral C2 Laminar Screwing, for Atlantoaxial Posterior Fixation

    PubMed Central

    Hongo, Michio; Kobayashi, Takashi; Suzuki, Tetsuya; Abe, Eiji; Shimada, Yoichi

    2014-01-01

    Study Design A retrospective study. Purpose To compare clinical and radiological outcomes between bilateral C2 pedicle screwing (C2PS) and unilateral C2PS, combined with contralateral C2 laminar screwing (LS), for posterior atlantoaxial fixation. Overview of Literature Posterior fixation with C1 lateral mass screwing (C1LMS) and C2PS (C1LMS-C2PS method) is an accepted procedure for rigid atlantoaxial stabilization. However, conventional bilateral C2PS is not always allowed in this method due to anatomical variations of C2 pedicles and/or asymmetry of the vertebral artery. Although unilateral C2PS plus contralateral LS (C2PS+LS) is an alternative in such cases, the efficacy of this procedure has not been evaluated in controlled studies (i.e., with bilateral C2PS as a control). Methods Clinical and radiological records of patients who underwent the C1LMS-C2PS method, using unilateral C2PS+LS (n=9), and those treated using conventional bilateral C2PS (n=10) were compared, with a minimum two years follow-up. Results Postoperative complications related to the unilateral C2PS+LS technique included one case of spontaneous spinous process fracture of C2. A C1 anterior arch fracture occurred after a fall in one patient, who underwent bilateral C2PS and C1 laminectomy. No significant differences were seen between the groups in reduction of neck pain after surgery or improvement of neurological status, as evaluated using the Japanese Orthopaedic Association score. A delayed union occurred in one patient each of the groups, with the final fusion rate being 100% in both groups. Conclusions Clinical and radiological outcomes of unilateral C2PS+LS were comparable with those of the bilateral C2PS fixation technique for the C1LMS-C2PS method. PMID:25558320

  8. A transaction cost approach to unilateral presidential action 

    E-print Network

    Marchbanks, Miner Peek, III

    2006-04-12

    chooses between seeking congressional action versus acting unilaterally through executive orders to accomplish policy change. The theory holds that when presidents desire policy change, they balance the transaction costs executive orders and legislative...

  9. Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients

    Microsoft Academic Search

    C. M. Kingma; H. P. Wit

    2011-01-01

    Vestibular evoked myogenic potentials (VEMPs) were measured in 22 unilateral Menière patients with monaural and binaural stimulation\\u000a with 250 and 500 Hz tone bursts. For all measurement situations significantly lower VEMP amplitudes were on average measured\\u000a at the affected side compared to the unaffected side. Unilateral Menière patients have, in contrast to normal subjects, asymmetric\\u000a VEMPs, indicating a permanently affected vestibular

  10. Surgery for unilateral bronchiectasis: Results and prognostic factors

    Microsoft Academic Search

    M. Ashour; K. M. Al-Kattan; S. K. Jain; S. Al-Majed; F. Al-Kassimi; A. Mobaireek; M. Al-Hajjaj; A. Al-Zear

    1996-01-01

    Setting: King Khalid University Hospital referral centre for thoracic surgery, Riyadh, Saudi Arabia.Objective: To assess the results of surgery and factors influencing its outcome in patients with unilateral bronchiectasis.Design: A retrospective analysis of 40 patients with unilateral bronchiectasis who were operated upon consecutively at King Khalid Hospital, between July 1987 and May 1993.Results: Left-sided disease was seen in 60% (n

  11. Grip Force Coordination during Bimanual Tasks in Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Islam, Mominul; Gordon, Andrew M.; Skold, Annika; Forssberg, Hans; Eliasson, Ann-Christin

    2011-01-01

    Aim: The aim of the study was to investigate coordination of fingertip forces during an asymmetrical bimanual task in children with unilateral cerebral palsy (CP). Method: Twelve participants (six males, six females; mean age 14y 4mo, SD 3.3y; range 9-20y;) with unilateral CP (eight right-sided, four left-sided) and 15 age-matched typically…

  12. Advances of unilateral mobile NMR in nondestructive materials testing

    Microsoft Academic Search

    Bernhard Blümich; Federico Casanova; Juan Perlo; Sophia Anferova; Vladimir Anferov; Kai Kremer; Nicolae Goga; Klaus Kupferschläger; Michael Adams

    2005-01-01

    Unilateral mobile NMR employs portable instrumentation with sensors, which are applied to the object from one side. Based on the principles of well-logging NMR, a hand-held sensor, the NMR-MOUSE (MObile Universal Surface Explorer) has been developed for nondestructive materials testing. In the following, a number of new applications of unilateral NMR in materials science are reviewed. They are the state

  13. Major haemorrhage in pubic rami fractures.

    PubMed

    Tang, Chun Hong; Shivji, Faiz; Forward, Daren

    2015-01-01

    A 62-year-old man presented to the emergency department, having fallen 6?ft from a ladder, with pain over his left hip and shoulder. He was managed according to the Advanced Trauma Life Support (ATLS) protocol, and his primary survey showed no haemodynamic compromise. Initial radiographs showed a unilateral left superior and inferior pubic rami fracture, which was treated conservatively. Forty-eight hours post-admission, the patient became tachycardic and hypotensive and was found to have dropped his haemoglobin from 125 to 89?g/L. After resuscitation, a repeat contrast CT scan revealed an enlarging haematoma in his pelvis. This was treated with urgent angioembolisation and the patient was further stabilised in the intensive care unit. This report shows the need for a low threshold in suspecting intrapelvic bleeds in patients with pubic rami fractures, and the need for prompt treatment of such patients, either surgically or radiologically. PMID:25739798

  14. Unilateral cryptorchidism in mice mutant for Ptgds.

    PubMed

    Philibert, Pascal; Boizet-Bonhoure, Brigitte; Bashamboo, Anu; Paris, Françoise; Aritake, Kosuke; Urade, Yoshihiro; Leger, Juliane; Sultan, Charles; Poulat, Francis

    2013-02-01

    The pathophysiology of cryptorchidism, abnormal testicular descent, remains poorly understood. In this study, we show that both heterozygous and homozygous mice deficient for lipocalin-type prostaglandin D(2) (PGD(2) ) synthase (Ptgds) presented unilateral cryptorchidism affecting the second phase of testicular descent in 16% and 24% of cases, respectively. The adult cryptorchid testes show an increase in spermatogonia apoptosis along with a global decrease in the tubule size parameters, whereas the gubernaculum of newborn mutants present some histological abnormalities. Disruption of the inguinoscrotal phase did not present impairment of the androgen pathway but rather a decrease in Rxfp2 mRNA expression in the gubernaculum. These observations led us to investigate the role of the PGD(2) signaling pathway in human testicular migration through PTGDS sequencing of DNA from 29 children with cryptorchidism. However, none of the investigated cases presented mutations in the PTGDS gene. Nevertheless, our results identify the PTGDS enzyme as a novel component in the cryptorchidism puzzle. PMID:23076868

  15. Trigeminal Neuralgia: Unilateral Episodic Facial Pain.

    PubMed

    Zakrzewska, Joanna M

    2015-06-01

    Trigeminal neuralgia is a rare cause of episodic unilateral facial pain and often in the initial presentation dental causes need to be eliminated, as it frequently presents in the lower trigeminal divisions. The pain description is characteristic of electric shock-like pain that is light-touch provoked, paroxysmal, and occurring daily; the condition can go into remission for weeks or months, however. The first-line drug is either carbamazepine or oxcarbazepine and has to be started in low doses. Over 70% of patients will initially obtain immediate relief. If efficacy or tolerability becomes a problem, then referral to a secondary care specialist should be made. Magnetic resonance imaging (MRI) scans can determine if there is a symptomatic cause and whether surgery is indicated. Surgical options provide longest pain relief periods. Patients need to be given information about all treatment options so they can make a decision about treatment. This report is adapted from paineurope 2014; Issue 4, © Haymarket Medical Publications Ltd., and is presented with permission. paineurope is provided as a service to pain management by Mundipharma International, Ltd., and is distributed free of charge to health care professionals in Europe. Archival issues can be viewed via the Web site: www.paineurope.com , at which health professionals can find links to the original articles and request copies of the quarterly publication and access additional pain education and pain management resources. PMID:26095494

  16. Ventriloquism in patients with unilateral visual neglect.

    PubMed

    Bertelson, P; Pavani, F; Ladavas, E; Vroomen, J; de Gelder B

    2000-01-01

    Can visual stimuli that go undetected, because they are presented in the extinguished region of neglect patients' visual field, nevertheless shift in their direction the apparent location of simultaneous sounds (the well-known 'ventriloquist effect')? This issue was examined using a situation in which each trial involved the simultaneous presentation of a tone over loudspeakers, together with a bright square area on either the left, the right or both sides of fixation. Participants were required to report the presence of squares, and indicate by hand pointing the apparent location of the tone. Five patients with left hemineglect consistently failed to detect the left square, either presented alone or together with another square on the right. Nevertheless, on bimodal trials with a single undetected square to the left, their sound localization was significantly shifted in the direction of that undetected square. By contrast, in bimodal trials with either a single square on the right or a square on each side, their sound localization showed only small and non-significant shifts. This particular result might be due to a combination of low discrimination of lateral sound deviations with variable individual strategies triggered by conscious detection of the right square. The important finding is the crossmodal bias produced by the undetected left visual distractors. It provides a new example of implicit processing of inputs affected by unilateral visual neglect, and on the other hand is consistent with earlier demonstrations of the automaticity of crossmodal bias. PMID:11074086

  17. Vertical Fracture Containment During Massive Hydraulic Fracturing

    Microsoft Academic Search

    D. E. Cormack; R. L. Fung; S. Vijayakumar

    1983-01-01

    Massive hydraulic fractures are projected to play a major role in the recovery of the tremendous reserves of gas tied up in the tight gas sands of the Deep Basin of N. Alberta and British Columbia. One of the major problems in designing fractures in such formations is the uncertain vertical extent of these fractures: fracture containment. This work presents

  18. The impacts of Unilateral Stratospheric Geoengineering

    NASA Astrophysics Data System (ADS)

    Jones, A.; Haywood, J. M.; Bellouin, N.; Stephenson, D.

    2013-12-01

    Stratospheric geoengineering proposals have been suggested on the premise that the cooling impacts of volcanic eruptions could be deliberately mimicked to offset the impacts of increased greenhouse gas concentrations in the future by counterbalance global warming. Here, we examine both the impacts of hemispherically asymmetric volcanoes in the observational record and the impact of prolonged deliberate injection of stratospheric aerosol into either the northern or southern hemisphere stratosphere or into both hemispheres equally to assess the impacts on Sahelian rainfall and agriculture (Haywood et al., 2013). While the frequency of volcanic eruptions during the past 100 years is too sparse for definitive attribution, there is a suggestion that volcanic eruptions that preferentially load the northern hemisphere are the harbinger of Sahelian drought. Simulations are then performed with the HadGEM2 couple atmospheric-ocean model to assess the impacts of these volcanic eruptions and deliberate unilateral stratospheric geoengineering. Figure 1 shows the impacts of the geoengineering simulations which show that stratospheric injection into the northern hemisphere induces a severe and prolonged Sahelian drought with undoubted detrimental consequences for the local population. Conversely injection into the southern hemisphere causes a significant greening of the Sahel with vegetation productivity enhanced by over 100%. On the face of it, this suggests potential advocacy of injection into the southern hemisphere: we will investigate potential other side-effects from such a strategy...... Haywood, J.M., A. Jones, N. Bellouin, and D.B. Stephenson, Asymmetric forcing from stratospheric aerosols impacts Sahelian drought, Nature Climate Change, Vol 3, No 7, 660-665, doi: 10.1038/NCLIMATE1857, 2013.

  19. Perception of colour in unilateral tritanopia.

    PubMed Central

    Alpern, M; Kitahara, K; Krantz, D H

    1983-01-01

    The unilateral tritanope described in the previous paper (Alpern, Kitahara & Krantz, 1983) was able to match every narrow-band light presented to his tritanopic eye with lights from a tristimulus colorimeter viewed in the adjacent field by the normal eye. In two regions of the spectrum (called isochromes) physically identical lights appeared identical to the observer's two eyes. One isochrome was close to 'blue' for the normal eye, the other was in the long-wave spectral region seen by the normal eye predominantly as 'red'. Between these isochromes the normal eye required less than spectral purity to match, dropping to near zero purity at 560-570 nm. A mixture of the two isochromes that appeared purple to the normal eye appeared neutral to the tritanopic eye. Hence dichoptic matches grossly violate Grassmann's additivity law. For the normal eye colour naming conformed to typical normal results. For the tritanopic eye the results were coherent with those found by dichoptic matching: the spectrum was divided into two regions by the achromatic neutral band. To the short-wave side, only the colour names 'blue' and 'white' were ever used. To the long-wave side the predominant colour names were 'red' and 'white' with some 'yellow'. Spectral lights appeared neither 'red-blue' nor greenish. Surrounding the test with an annulus either 430 nm, 650 nm, or a mixture of these, fails to induce any greenish appearance, although the achromatic band shifted in the expected directions. It is concluded that there must be exactly three functionally independent, essentially non-linear central codes for colour perception, and that these codes are different from those suggested in existing theories of colour perception. PMID:6603509

  20. Impact of unilateral denervation on transdiaphragmatic pressure.

    PubMed

    Gill, Luther C; Mantilla, Carlos B; Sieck, Gary C

    2015-05-01

    The diaphragm muscle (DIAm) has a large reserve capacity for force generation such that in rats, the transdiaphragmatic pressure (Pdi) generated during ventilatory behaviors is less than 50% of maximal Pdi (Pd(imax)) elicited by bilateral phrenic nerve stimulation. Accordingly, we hypothesized that following unilateral denervation (DNV), the ability of the contralateral DIAm to generate sufficient Pdi to accomplish ventilatory behaviors will not be compromised and normal ventilation (as determined by arterial blood gas measurements) will not be impacted, although neural drive to the DIAm increases. In contrast, we hypothesized that higher force, non-ventilatory behaviors requiring Pdi generation greater than 50% of Pd(imax) will be compromised following DIAm hemiparalysis, i.e., increased neural drive cannot fully compensate for lack of force generating capacity. Pdi generated during ventilatory behaviors (eupnea and hypoxia (10% O2)-hypercapnia (5% CO2)) did not change after DNV and arterial blood gases were unaffected by DNV. However, neural drive to the contralateral DIAm, assessed by the rate of rise of root mean squared (RMS) EMG at 75 ms after onset of inspiratory activity (RMS75), increased after DNV (p<0.05). In contrast, Pdi generated during higher force, non-ventilatory behaviors was significantly reduced after DNV (p < 0.01), while RMS75 was unchanged. These findings support our hypothesis that only non-ventilatory behaviors requiring Pdi generation greater than 50% of Pd(imax) are impacted after DNV. Clinically, these results indicate that an evaluation of DIAm weakness requires examination of Pdi across multiple motor behaviors, not just ventilation. PMID:25641347

  1. Sleep Disordered Breathing in Isolated Unilateral and Bilateral Diaphragmatic Dysfunction

    PubMed Central

    Khan, Akram; Morgenthaler, Timothy I.; Ramar, Kannan

    2014-01-01

    Introduction: The effect of isolated unilateral or bilateral diaphragmatic dysfunction (DD), in the absence of a generalized neuromuscular disorder, on sleep disordered breathing (SDB) is not well understood. The type of positive airway pressure (PAP) device needed to treat SDB in patients with isolated DD is also not well established. Methods: We retrospectively analyzed data on patients with isolated unilateral or bilateral DD who were referred for polysomnography (PSG) for clinical symptoms or abnormal oximetry between 1994 and 2006. Results: We found 66 patients who met criteria, of whom 74.2% were males with an average age of 58.8 ± 10.9 years. 56 had isolated unilateral DD, and 10 had isolated bilateral DD. All had significant SDB with an apnea-hypopnea index (AHI) of 26.6 ± 28.4. There were no significant differences in PSG measures, arterial blood gas analysis, pulmonary function tests, or echocardiographic data, except for lower maximal inspiratory pressure in patients with bilateral DD compared to unilateral DD (40.2% ± 17.8% vs. 57.7% ± 20.5%, p = 0.02). Control of SDB with continuous PAP (CPAP) was possible in only 37.9% of patients with the rest requiring bilevel PAP (BPAP). Patients with isolated bilateral DD and SDB were 6.8 times more likely to fail CPAP than those with unilateral DD (p = 0.03). Conclusions: Most patients with isolated DD failed CPAP and required BPAP. Patients with bilateral DD were more likely to require BPAP than those with unilateral DD. Patients with isolated DD should be considered for in-lab titration to determine adequacy of therapy. Citation: Khan A, Morgenthaler TI, Ramar K. Sleep disordered breathing in isolated unilateral and bilateral diaphragmatic dysfunction. J Clin Sleep Med 2014;10(5):509-515. PMID:24910552

  2. Analysis of nasal bone fractures; a six-year study of 503 patients.

    PubMed

    Hwang, Kun; You, Sun Hye; Kim, Sun Goo; Lee, Se Il

    2006-03-01

    The aim of this study is to classify the nasal bone fractures based on computed tomography (CT) analysis and patterns of the nasal bone fractures, and review 503 cases treated between 1998-2004 at the Department of Plastic Surgery, Inha University Hospital, Incheon, South Korea. The age, sex, etiology, associated injuries, pattern of fractures and treatments were reviewed and a radiographic study was analyzed. Plain simple radiographs of lateral and Waters view of the nasal bones combined with computed tomography scans were done. Nasal bone fractures were classified into six types: Type I) Simple without displacement; Type II) Simple with displacement/without telescoping; IIA; Unilateral; IIAs) Unilateral with septal fracture; IIB) Bilateral; IIBs) Bilateral with septal fracture; Type III) Comminuted with telescoping or depression. Diagnosis of nasal bone fractures were made positively by plain x-ray films in 82% of cases, negative finding was 9.5% and 8.5% of cases were suspicious of the fractures. Reliability of the plain film radiographs of the nasal bone fracture was 82% in this study. In the most of the fractured nasal bones (93%) the closed reduction was done, open reduction in 4% and no surgical intervention in 3%. Nasal reduction was carried out in average 6.5 days post the injury. The patterns of the nasal bones fractures classified by CT findings were type IIA (182 cases, 36%), IIBs (105 cases, 21%), IIB (90 cases, 18%), IIAs (66 cases, 13%), I (39 cases, 8%) and III (21 cases, 4.3%). We think the CT is necessary for diagnosing nasal bone fracture because the reliability of the plain film was only 82%. PMID:16633172

  3. Comparison of plate-screw systems used in mandibular fracture reduction: finite element analysis.

    PubMed

    Lovald, Scott T; Khraishi, Tariq; Wagner, Jon; Baack, Bret; Kelly, James; Wood, John

    2006-10-01

    A finite element model of the human dentate mandible has been developed to provide a comparison of fixation systems used currently for fracture reduction. Volume domains for cortical bone, cancellous bone, and teeth were created and meshed in ANSYS 8.0 based on IGES curves created from computerized tomography data. A unilateral molar clench was loaded on the model with a fracture gap simulated along the symphysis. Results based on Von Mises stress in cortical and cancellous bone surrounding the screws, and on fracture surface spatial fixation, show some relative differences between different screw-plate systems, yet all were judged to be appropriate in their reduction potential. PMID:16995751

  4. Faster imaging with a portable unilateral NMR device.

    PubMed

    Liberman, Asaf; Bergman, Elad; Sarda, Yifat; Nevo, Uri

    2013-06-01

    Unilateral NMR devices are important tools in various applications such as non-destructive testing and well logging, but are not applied routinely for imaging, primarily because B0 inhomogeneity in these scanners leads to a relatively low signal and requires use of the slow single point imaging scan scheme. Enabling high quality, fast imaging could make this affordable and portable technology practical for various imaging applications as well as for new applications that are not yet feasible with MRI technology. The goal of this work was to improve imaging times in a portable unilateral NMR scanner. Both Compressed Sensing and Fast Spin Echo were modified and applied to fit the unique characteristics of a unilateral device. Two printed phantoms, allowing high resolution images, were scanned with both methods and compared to a standard scan and to a low pass scan to evaluate performance. Both methods were found to be feasible with a unilateral device, proving ways to accelerate single point imaging in such scanners. This outcome encourages us to explore how to further accelerate imaging times in unilateral NMR devices so that this technology might become clinically applicable in the future. PMID:23597948

  5. Long Bone Fractures

    Microsoft Academic Search

    Jennifer C. Love; Sharon M. Derrick; Jason M. Wiersema

    \\u000a Fractures occurring in the humerus, ulna, radius, femur, tibia, and fibula are collectively categorized as long bone fractures.\\u000a Long bone fractures are further classified by type and location. Interpretation of the forces associated with the fracture\\u000a depends on the location, type, and extent of the fracture. Common long bone fracture types include spiral, oblique, transverse,\\u000a torus (or buckle), greenstick, and

  6. Advances of unilateral mobile NMR in nondestructive materials testing.

    PubMed

    Blümich, Bernhard; Casanova, Federico; Perlo, Juan; Anferova, Sophia; Anferov, Vladimir; Kremer, Kai; Goga, Nicolae; Kupferschläger, Klaus; Adams, Michael

    2005-02-01

    Unilateral mobile NMR employs portable instrumentation with sensors, which are applied to the object from one side. Based on the principles of well-logging NMR, a hand-held sensor, the NMR-MOUSE (MObile Universal Surface Explorer) has been developed for nondestructive materials testing. In the following, a number of new applications of unilateral NMR in materials science are reviewed. They are the state assessment of polyethylene pipes, the characterization of wood, the in situ evaluation of stone conservation treatment, high-resolution profiling of rubber tubes and 2-D imaging for defect analysis in rubber products. PMID:15833612

  7. A unilateral optic perineuritis in a teenager - A case report.

    PubMed

    Ameilia, Ahmad; Shatriah, Ismail; Wan-Hitam, Wan Hazabbah; Yunus, Rohaizan

    2015-06-01

    Optic perineuritis is an uncommon inflammatory disorder that involves optic nerve sheath. Numerous case reports have been published on optic perineuritis in adults, the majority of whom had bilateral presentation. There are limited data on optic perineuritis occurring in pediatric patients. We report a teenager who presented with a unilateral sign that mimicked the presentation of optic neuritis. The orbit and brain magnetic resonance imaging confirmed features of unilateral optic perineuritis. She was treated with a high dose of corticosteroids for 2weeks, and her final visual outcome was satisfactory. No signs of relapse were noted during follow-up visits. PMID:25457086

  8. Teaching neuroimages: anoxic brain injury with unilateral hemispheric cortical involvement.

    PubMed

    Kim, Yong-Won; Seo, Ji-Hye; Park, Sung-Pa; Hwang, Yang-Ha

    2013-04-01

    A 55-year-old woman collapsed with chest pain and cardiac arrest. Her pulse was restored after 6 minutes of cardiopulmonary resuscitation, but she remained comatose. Brain MRI (figure) revealed bilateral basal ganglia and right hemispheric cortical lesion, which was typical for anoxic brain injury except for the unilateral cortical involvement. Neck CT angiography showed severe stenosis in the right proximal internal carotid artery. The unilateral cortical injury could be explained by compromised cerebral blood flow due to preexisting carotid stenosis. This case demonstrates an atypical pattern of anoxic brain injury secondary to focal vascular stenosis. PMID:23547273

  9. The Effective Fracture Toughness in Hydraulic Fracturing

    Microsoft Academic Search

    Panos Papanastasiou

    1999-01-01

    This paper examines the effective fracture toughness approach which is used in hydraulic fracturing in order to explain the\\u000a high net-pressures that are often observed in field operations. The effective fracture toughness is calculated using a fully\\u000a deterministic elasto-plastic hydraulic fracturing model. Rock is modelled by Mohr–Coulomb flow theory of plasticity for cohesive-frictional\\u000a dilatant material. Fluid flow is modelled by

  10. Intravenous Application of CD271-selected Mesenchymal Stem Cells during Fracture Healing

    PubMed Central

    Dreger, Tina; Watson, John Tracy; DVM, Walter Akers; Molligan, Jeremy; Achilefu, Samuel; Schon, Lew C.; Zhang, Zijun

    2014-01-01

    Objectives Circulating mesenchymal stem cells (MSCs) participate in fracture healing and can be used to enhance fracture healing. This study investigated how CD271-selected MSCs travel in circulation and when it is the optimal time to apply MSCs intravenously during fracture healing. Methods Based on the expression of CD271, MSCs were isolated from human bone marrow and labeled with cypate, a near infrared fluorochrome. A unilateral closed fracture was created at the femur in immunodeficient mice. The cypate-labeled MSCs were injected into the tail vein of the mice at days 1 and 3 after fracture, and were tracked by near infrared imaging. The mice were euthanized at 3 weeks after fracture. Immunohistochemistry was performed to detect human MSCs at the fracture sites. Migration of CD271-selected MSCs, under the influence of stem cell derived factor-1 (SDF-1), was assessed in vitro. Results Intravenously injected at day1, but not day 3, after fracture, CD271-selected MSCs accumulated at the fracture sites significantly and that lasted for at least 7 days. All fractures, with or without MSC injections, healed in 3 weeks. Human cells were localized at the fracture sites in mice by immunohistochemistry. CD271-selected MSCs migrated toward the medium contained SDF-1 in vitro. Conclusions After intravenous injection, CD271-selected MSCs were recruited to fracture sites. The stages of fracture healing influenced the homing of culture-expanded MSCs. In mice, an optimal window of intravenous injection of MSCs was around 24 hours after fracture. Clinical Relevance Intravenous application of MSCs may serve as a practical route to deliver stem cells for the treatment of fracture non-union and delayed union. Levels of evidence Level I PMID:24378433

  11. On unilateral divorce and the “selection of marriages” hypothesis

    Microsoft Academic Search

    Eric Langlais

    2010-01-01

    In this paper, the unilateral divorce law is modelled through the combination of exclusive rights on the marriage dissolution and alternative compensation rules benefiting to the parent having custody of the children. Their influence are studied both in the short run (probability and efficiency of divorce) and in the long run (selection of marriages). We show that a decrease in

  12. Channel Incentives as Unilateral and Bilateral Governance Processes

    Microsoft Academic Search

    David I. Gilliland; Daniel C. Bello

    2001-01-01

    The authors investigate channel incentives as extra-contractual governance processes that maintain and extend marketing channel relationships. More specifically, instrumental incentives are monetary-based payments made by a manufacturer in a unilateral channel arrangement to motivate distributor compliance, while equity incentives are bilateral expectations of fair treatment that motivate both parties to continue to cooperate with one another. A model of the

  13. Epileptic Features of Patients With Unilateral and Bilateral Schizencephaly

    Microsoft Academic Search

    Camila F. Lopes; Fernando Cendes; Ana Maria S. G. Piovesana; Fábio Torres; Iscia Lopes-Cendes; Maria Augusta Montenegro; Marilisa M. Guerreiro

    2006-01-01

    The extent of cortical maldevelopment might correlate with the severity of the clinical manifestation, such as cognitive delay or motor dysfunction. The objective of this study was to investigate the clinical features of epilepsy in patients with unilateral and bilateral schizencephaly. We studied 44 consecutive patients with schizencephaly diagnosed by magnetic resonance imaging (MRI). The epileptic features were analyzed in

  14. Traumatic glaucoma with features of unilateral pigment dispersion

    PubMed Central

    Bowler, Gordon; Ellul, Antony; Gouws, Pieter

    2014-01-01

    Summary We report a patient with traumatic glaucoma with features of unilateral pigment dispersion. This rare form of secondary glaucoma has only been reported twice previously, with both patients demonstrating angle recession, indicating associated damage to the trabecular meshwork. To our knowledge, this is the first such case reported in which angle recession was absent. PMID:25097455

  15. Unilateral Forced Nostril Breathing Affects Dichotic Listening for Emotional Tones

    ERIC Educational Resources Information Center

    Saucier, Deborah M.; Tessem, Farzana Karim; Sheerin, Aaron H.; Elias, Lorin

    2004-01-01

    Unilateral forced nostril breathing (UFNB) through the left nostril is associated with enhanced spatial abilities, whereas UFNB through the right nostril is associated with enhanced verbal abilities. However, the effects of UFNB on standard tasks of laterality (e.g., dichotic listening) are unknown. This study employed dichotic listening for word…

  16. Unilateral convulsion after induction of anaesthesia with propofol

    Microsoft Academic Search

    D. COCHRAN; C. L. GWINNUTT

    Summary We report a case in which a 42-yr-old man suffered a unilateral convulsion immediately after i.v. in- jection of propofol, and was discovered subse- quently to have an old contralateral cerebral infarct. This complication and the current information on the relationship between propofol and abnormal neurological activity are discussed. (Br. J. Anaesth. 1996; 76: 570-572)

  17. Unilateral Subcortical Calcification: A Manifestation of Dural Arteriovenous Fistula

    Microsoft Academic Search

    Ming-Shiang Yang; Clayton Chi-Chang Chen; Yung-Yi Cheng; Da-Ming Yeh; San-Kan Lee; Yeu-Sheng Tyan

    Summary: We describe the imaging findings in a dural arteriovenous fistula (AVF) with unilateral subcortical calcification. A 50-year-old woman patient suffered from hypertension and chronic headache. Recently, marked headache and a changed consciousness level were noted. The imaging studies demonstrated left subcortical calci- fication and cerebral sulcus effacement. MR imaging and angiography revealed multiple abnormal tortuous vessels, mainly from left

  18. Unilateral internuclear ophthalmoplegia as an isolated presentation of metastatic melanoma.

    PubMed

    Kumar, Sunil; Kent, Shefalee S; Sundaram, Arun N; Sharma, Manas

    2015-03-01

    Multiple sclerosis in younger patients and brainstem infarction in the elderly are the most common causes of internuclear ophthalmoplegia (INO). We report unilateral INO as the isolated clinical manifestation of a large, solitary, metastatic melanoma in the pons. Brain metastasis can present as INO. PMID:25232840

  19. Coupling of FM Systems to Individuals with Unilateral Hearing Loss.

    ERIC Educational Resources Information Center

    Kopun, Judy G.; And Others

    1992-01-01

    This study examined the attenuation characteristics of 5 Frequency Modulation system sound delivery options for 25 adults and children (ages 5-13). Degree of ear canal occlusion was a major factor in degree of attenuation. For children with unilateral hearing impairments, the most acoustically appropriate option was the tube-fitting. (Author/JDD)

  20. Power as a Factor in Unilaterally and Bilaterally Coercive Situations.

    ERIC Educational Resources Information Center

    Bonoma, Thomas V.

    This paper discusses the concept and definition of social power as it relates to an understanding of social behavior at all levels. The author attempts to differentiate power situations in which the flow of influence is primarily unilateral from an identifiable source to a target, from those in which there is a more dynamic give-and-take between…

  1. Shipping and climate change: Scope for unilateral action

    E-print Network

    Matthews, Adrian

    Shipping and climate change: Scope for unilateral action Paul Gilbert, Tyndall Manchester Alice on international shipping emissions and climate change undertaken at The University of Manchester by the Tyndall considers the role that the shipping sector could play in mitigating total global emissions

  2. Outcomes After Unilateral Uterine Artery Embolization: A Retrospective Review

    SciTech Connect

    Bratby, M. J. [St George's Hospital, Radiology Department (United Kingdom); Hussain, F. F.; Walker, W. J. [Royal Surrey County Hospital, Radiology Department (United Kingdom)], E-mail: wj.walker@virgin.net

    2008-03-15

    Purpose. Bilateral uterine artery embolization (UAE) is considered necessary to provide effective treatment for symptomatic uterine fibroids. Occasionally, only unilateral embolization is performed, and this study evaluates these outcomes. Materials and Methods. As part of a prospective observational study of more than 1600 patients treated with UAE since 1996, there have been 48 patients in whom unilateral embolization has been performed. This study retrospectively reviews clinical response as assessed by our standard questionnaire and radiological response assessed by either magnetic resonance imaging or ultrasound. Results. Two principal groups emerged: the largest, where only the dominant unilateral arterial supply was electively embolized (30 patients); and the second, where there was technical failure to catheterize the second uterine artery as a result of anatomical constraints (12 patients). Favorable clinical response with a reduction in menorrhagia at 1 year was seen in 85.7% (18/21) of those patients with a dominant arterial supply to the fibroid(s). In contrast, in those patients where there was technical failure to embolize one uterine artery, there was a high rate of clinical failure requiring further intervention in 58.3% (7/12). Comparison of the technical failure group with the dominant uterine artery group demonstrated a statistically significant (Fisher's exact test) difference in the proportion of patients with evidence of persistent fibroid vascularity (p < 0.001) and requiring repeat intervention (p < 0.01). Conclusion. We conclude that unilateral UAE can achieve a positive clinical result in the group of patients where there is a dominant unilateral artery supplying the fibroid(s), in contrast to the poor results seen following technical failure.

  3. An analytical methodology for magnetic field control in unilateral NMR

    NASA Astrophysics Data System (ADS)

    Marble, Andrew E.; Mastikhin, Igor V.; Colpitts, Bruce G.; Balcom, Bruce J.

    2005-05-01

    Traditionally, unilateral NMR systems such as the NMR-MOUSE have used the fringe field between two bar magnets joined with a yoke in a 'U' geometry. This allows NMR signals to be acquired from a sensitive volume displaced from the magnets, permitting large samples to be investigated. The drawback of this approach is that the static field ( B0) generated in this configuration is inhomogeneous, and has a large, nonlinear, gradient. As a consequence, the sensitive volume of the instrument is both small and ill defined. Empirical redesign of the permanent magnet array producing the B0 field has yielded instruments with magnetic field topologies acceptable for varying applications. The drawback of current approaches is the lack of formalism in the control of B0. Rather than tailoring the magnet geometry to NMR investigations, measurements must be tailored to the available magnet geometry. In this work, we present a design procedure whereby the size, shape, field strength, homogeneity, and gradients in the sensitive spot of a unilateral NMR sensor can be controlled. Our design uses high permeability pole pieces, shaped according to the contours of an analytical expression, to control B0, allowing unilateral NMR instruments to be designed to generate a controlled static field topology. We discuss the approach in the context of previously published design techniques, and explain the advantages inherent in our strategy as compared to other optimization methods. We detail the design, simulation, and construction of a unilateral magnet array using our approach. It is shown that the fabricated array exhibits a B0 topology consistent with the design. The utility of the design is demonstrated in a sample nondestructive testing application. Our design methodology is general, and defines a class of unilateral permanent magnet arrays in which the strength and shape of B0 within the sensitive volume can be controlled.

  4. An analytical methodology for magnetic field control in unilateral NMR.

    PubMed

    Marble, Andrew E; Mastikhin, Igor V; Colpitts, Bruce G; Balcom, Bruce J

    2005-05-01

    Traditionally, unilateral NMR systems such as the NMR-MOUSE have used the fringe field between two bar magnets joined with a yoke in a 'U' geometry. This allows NMR signals to be acquired from a sensitive volume displaced from the magnets, permitting large samples to be investigated. The drawback of this approach is that the static field (B0) generated in this configuration is inhomogeneous, and has a large, nonlinear, gradient. As a consequence, the sensitive volume of the instrument is both small and ill defined. Empirical redesign of the permanent magnet array producing the B0 field has yielded instruments with magnetic field topologies acceptable for varying applications. The drawback of current approaches is the lack of formalism in the control of B0. Rather than tailoring the magnet geometry to NMR investigations, measurements must be tailored to the available magnet geometry. In this work, we present a design procedure whereby the size, shape, field strength, homogeneity, and gradients in the sensitive spot of a unilateral NMR sensor can be controlled. Our design uses high permeability pole pieces, shaped according to the contours of an analytical expression, to control B0, allowing unilateral NMR instruments to be designed to generate a controlled static field topology. We discuss the approach in the context of previously published design techniques, and explain the advantages inherent in our strategy as compared to other optimization methods. We detail the design, simulation, and construction of a unilateral magnet array using our approach. It is shown that the fabricated array exhibits a B0 topology consistent with the design. The utility of the design is demonstrated in a sample nondestructive testing application. Our design methodology is general, and defines a class of unilateral permanent magnet arrays in which the strength and shape of B0 within the sensitive volume can be controlled. PMID:15809175

  5. Fracture channel waves

    SciTech Connect

    Nihei, K.T.; Yi, W.; Myer, L.R.; Cook, N.G. [Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California (United States)] [Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California (United States); Schoenberg, M. [Schlumberger-Doll Research, Ridgefield, Connecticut (United States)] [Schlumberger-Doll Research, Ridgefield, Connecticut (United States)

    1999-03-01

    The properties of guided waves which propagate between two parallel fractures are examined. Plane wave analysis is used to obtain a dispersion equation for the velocities of fracture channel waves. Analysis of this equation demonstrates that parallel fractures form an elastic waveguide that supports two symmetric and two antisymmetric dispersive Rayleigh channel waves, each with particle motions and velocities that are sensitive to the normal and tangential stiffnesses of the fractures. These fracture channel waves degenerate to shear waves when the fracture stiffnesses are large, to Rayleigh waves and Rayleigh-Lamb plate waves when the fracture stiffnesses are low, and to fracture interface waves when the fractures are either very closely spaced or widely separated. For intermediate fracture stiffnesses typical of fractured rock masses, fracture channel waves are dispersive and exhibit moderate to strong localization of guided wave energy between the fractures. The existence of these waves is examined using laboratory acoustic measurements on a fractured marble plate. This experiment confirms the distinct particle motion of the fundamental antisymmetric fracture channel wave (A{sub 0} mode) and demonstrates the ease with which a fracture channel wave can be generated and detected. {copyright} 1999 American Geophysical Union

  6. Interactive fracture design model

    SciTech Connect

    Not Available

    1980-05-01

    A computer program is described that can be used to design a fracture stimulation treatment for a geothermal reservoir. The program uses state-of-the-art methods to calculate the temperature of the fracture fluid as a function of time and distance in the fracture. This information is used to determine the temperature dependent properties of the fracture fluid. These fluid properties are utilized to calculate the fracture geometry as a function of time. The fracture geometry and temperature distribution of the fracture fluid are coupled so the subroutines that calculate these distributions have been made interactive.

  7. Imaging of vertebral fractures.

    PubMed

    Panda, Ananya; Das, Chandan J; Baruah, Udismita

    2014-05-01

    Vertebral fracture is a common clinical problem. Osteoporosis is the leading cause of non-traumatic vertebral fracture. Often, vertebral fractures are not clinically suspected due to nonspecific presentation and are overlooked during routine interpretation of radiologic investigations. Moreover, once detected, many a times the radiologist fails to convey to the clinician in a meaningful way. Hence, vertebral fractures are a constant cause of morbidity and mortality. Presence of vertebral fracture increases the chance of fracture in another vertebra and also increases the risk of subsequent hip fracture. Early detection can lead to immediate therapeutic intervention improving further the quality of life. So, in this review, we wish to present a comprehensive overview of vertebral fracture imaging along with an algorithm of evaluation of vertebral fractures. PMID:24944921

  8. Imaging of vertebral fractures

    PubMed Central

    Panda, Ananya; Das, Chandan J.; Baruah, Udismita

    2014-01-01

    Vertebral fracture is a common clinical problem. Osteoporosis is the leading cause of non-traumatic vertebral fracture. Often, vertebral fractures are not clinically suspected due to nonspecific presentation and are overlooked during routine interpretation of radiologic investigations. Moreover, once detected, many a times the radiologist fails to convey to the clinician in a meaningful way. Hence, vertebral fractures are a constant cause of morbidity and mortality. Presence of vertebral fracture increases the chance of fracture in another vertebra and also increases the risk of subsequent hip fracture. Early detection can lead to immediate therapeutic intervention improving further the quality of life. So, in this review, we wish to present a comprehensive overview of vertebral fracture imaging along with an algorithm of evaluation of vertebral fractures. PMID:24944921

  9. Vertical fracture containment during massive hydraulic fracturing

    SciTech Connect

    Cormack, D.E.; Fung, R.L.; Vijayakumar, S.

    1983-01-01

    Massive hydraulic fractures are projected to play a major role in the recovery of the tremendous reserves of gas tied up in the tight gas sands of the Deep Basin of N. Alberta and British Columbia. One of the major problems in designing fractures in such formations is the uncertain vertical extent of these fractures: fracture containment. This work presents a procedure for predicting the vertical extent of fractures in multi-layered formations with varying material properties and tectonic stresses. The numeric procedure uses the finite element technique for the rock deformation calculations and employs special high order, crack-tip elements to improve the accuracy of stress intensity calculations. Furthermore, it makes use of the powerful numeric technique of static condensation to reduce computer memory and computation time. The elastic deformation calculation can be coupled to a fluid flow model to predict dynamic fracture growth.

  10. Unilateral Loss of Spontaneous Venous Pulsations in an Astronaut

    NASA Technical Reports Server (NTRS)

    Mader, Thomas H.; Gibson, C. Robert; Lee, Andrew G.; Patel, Nimesh; Hart, Steven; Pettit, Donald R.

    2014-01-01

    Spontaneous venous pulsations seen on the optic nerve head (optic disc) are presumed to be caused by fluctuations in the pressure gradient between the intraocular and retrolaminar venous systems. The disappearance of previously documented spontaneous venous pulsations is a well-recognized clinical sign usually associated with a rise in intracranial pressure and a concomitant bilateral elevation of pressure in the subarachnoid space surrounding the optic nerves. In this correspondence we report the unilateral loss of spontaneous venous pulsations in an astronaut 5 months into a long duration space flight. We documented a normal lumbar puncture opening pressure 8 days post mission. The spontaneous venous pulsations were also documented to be absent 21 months following return to Earth.. We hypothesize that these changes may have resulted from a chronic unilateral rise in optic nerve sheath pressure caused by a microgravity-induced optic nerve sheath compartment syndrome.

  11. Framework Surgery for Treatment of Unilateral Vocal Fold Paralysis

    PubMed Central

    Daniero, James J.; Garrett, C. Gaelyn; Francis, David O.

    2014-01-01

    Laryngeal framework surgery is the current gold standard treatment for unilateral vocal fold paralysis. It provides a permanent solution to glottic insufficiency caused by injury to the recurrent laryngeal nerve. Various modifications to the original Isshiki type I laryngoplasty procedure have been described to improve voice and swallowing outcomes. The success of this procedure is highly dependent on the experience of the surgeon as it epitomizes the intersection of art and science in the field. The following article reviews the evidence, controversies, and complications related to laryngoplasty for unilateral vocal fold paralysis. It also provides a detailed analysis of how and when arytenoid-positioning procedures should be considered, and summarizes the literature on postoperative outcomes. PMID:24883239

  12. Global suppression of electrocortical activity in unilateral perinatal thalamic stroke

    PubMed Central

    Kharoshankaya, Liudmila; Filan, Peter M; Bogue, Conor O; Murray, Deirdre M; Boylan, Geraldine B

    2014-01-01

    We present an unusual case of persistent generalized electroencephalography (EEG) suppression and right-sided clonic seizures in a male infant born at 40+2 weeks' gestation, birthweight 3240g, with an isolated unilateral thalamic stroke. The EEG at 13 hours after birth showed a generalized very low amplitude background pattern, which progressed to frequent electrographic seizures over the left hemisphere. The interictal background EEG pattern remained grossly abnormal over the next 48 hours, showing very low background amplitudes (<10?V). Magnetic resonance imaging revealed an isolated acute left-sided thalamic infarction. This is the first description of severe global EEG suppression caused by an isolated unilateral thalamic stroke and supports the role of the thalamus as the control centre for cortical electrical activity. PMID:24410068

  13. Ulnar styloid fracture in distal radius fractures managed with volar locking plates: to fix or not?

    PubMed

    Gogna, Paritosh; Selhi, Harpal Singh; Mohindra, Mukul; Singla, Rohit; Thora, Ankit; Yamin, Mohammad

    2014-12-01

    Distal radius fracture is usually associated with ulnar styloid fracture. Whether to fix the ulnar styloid or not remains a surgical dilemma as some surgeons believe that their repair is imperative while others feel that they should be managed conservatively. This prospective study involved 47 patients with unilateral fracture of the distal radius who met the inclusion criterion and underwent open reduction and internal fixation with volar locking plates; 28 patients (12 males and females?=?16) had an associated ulnar styloid fracture (Group A) while 19 (7 males; 12 females) did not have any ulnar styloid fracture (Group B). At the time of final evaluation both the groups were compared clinically by measuring the grip strength and range of motion around the wrist and the radiologically by measuring radial angle, radial length, volar angle and ulnar variance. Subjective assessment was done using DASH score and final assessment using Demerit point system of Saito. In Group A, average time for consolidation was 9.4 weeks, 17 patients developed non-union of the ulnar styloid, average DASH scores was 4.4 and according to Demerit point system of Saito, there were 78.5 % excellent, 17.9 % good and 3.6 % fair results; there were 2 cases of loss of reduction out of which one had persistent ulnar sided wrist pain. In Group B the average time for consolidation was 10.2 weeks, average DASH score was 3.8.and Demerit point system of Saito yielded 78.9 % excellent, 15.8 % good and 5.3 % fair results. There was one case of loss of reduction and one case of carpal tunnel syndrome which was managed conservatively. Both groups attained excellent range of motion, grip strength and well maintained the post operative radiological parameters. The comparison of clinico-radiological parameters in both groups was found to be statistically insignificant. To conclude, ulnar styloid fracture or its non union does not affect the outcome of an adequately fixed distal end radius fracture. We urge caution in electing operative treatment of non-united fracture of the ulnar styloid until better scientific report for treatment of pain associated with these fracture is available. PMID:25414551

  14. Splint renal function after captopril in unilateral renal artery stenosis

    Microsoft Academic Search

    G J Wenting; H L Tan-Tjiong; F H Derkx; J H de Bruyn; A J Man in't Veld; M A Schalekamp

    1984-01-01

    The renal extraction ratios of 131I-sodium iodohippurate (131I-Hippuran) and 125I-thalamate were greatly reduced on the affected side by 50 mg captopril in seven out of 14 patients with unilateral renal artery stenosis. With long term captopril 150 mg daily the uptake of 99mTc-diethylenetriaminepenta-acetic acid by the affected kidney, which was determined by scintillation camera renography, became almost zero in these

  15. Magnetic Vestibular Stimulation in Subjects with Unilateral Labyrinthine Disorders

    PubMed Central

    Ward, Bryan K.; Roberts, Dale C.; Della Santina, Charles C.; Carey, John P.; Zee, David S.

    2014-01-01

    We recently discovered that static magnetic fields from high-strength MRI machines induce nystagmus in all normal humans, and that a magneto-hydrodynamic Lorentz force, derived from ionic currents in the endolymph and pushing on the cupula, best explains this effect. Individuals with no labyrinthine function have no nystagmus. The influence of magnetic vestibular stimulation (MVS) in individuals with unilateral deficits in labyrinthine function is unknown and may provide insight into the mechanism of MVS. These individuals should experience MVS, but with a different pattern of nystagmus consistent with their unilateral deficit in labyrinthine function. We recorded eye movements in the static magnetic field of a 7 T MRI machine in nine individuals with unilateral labyrinthine hypofunction, as determined by head impulse testing and vestibular-evoked myogenic potentials (VEMP). Eye movements were recorded using infrared video-oculography. Static head positions were varied in pitch with the body supine, and slow-phase eye velocity (SPV) was assessed. All subjects exhibited predominantly horizontal nystagmus after entering the magnet head-first, lying supine. The SPV direction reversed when entering feet-first. Pitching chin-to-chest caused subjects to reach a null point for horizontal SPV. Right unilateral vestibular hypofunction (UVH) subjects developed slow-phase-up nystagmus and left UVH subjects, slow-phase-down nystagmus. Vertical and torsional components were consistent with superior semicircular canal excitation or inhibition, respectively, of the intact ear. These findings provide compelling support for the hypothesis that MVS is a result of a Lorentz force and suggest that the function of individual structures within the labyrinth can be assessed with MVS. As a novel method of comfortable and sustained labyrinthine stimulation, MVS can provide new insights into vestibular physiology and pathophysiology. PMID:24659983

  16. Magnetic vestibular stimulation in subjects with unilateral labyrinthine disorders.

    PubMed

    Ward, Bryan K; Roberts, Dale C; Della Santina, Charles C; Carey, John P; Zee, David S

    2014-01-01

    We recently discovered that static magnetic fields from high-strength MRI machines induce nystagmus in all normal humans, and that a magneto-hydrodynamic Lorentz force, derived from ionic currents in the endolymph and pushing on the cupula, best explains this effect. Individuals with no labyrinthine function have no nystagmus. The influence of magnetic vestibular stimulation (MVS) in individuals with unilateral deficits in labyrinthine function is unknown and may provide insight into the mechanism of MVS. These individuals should experience MVS, but with a different pattern of nystagmus consistent with their unilateral deficit in labyrinthine function. We recorded eye movements in the static magnetic field of a 7 T MRI machine in nine individuals with unilateral labyrinthine hypofunction, as determined by head impulse testing and vestibular-evoked myogenic potentials (VEMP). Eye movements were recorded using infrared video-oculography. Static head positions were varied in pitch with the body supine, and slow-phase eye velocity (SPV) was assessed. All subjects exhibited predominantly horizontal nystagmus after entering the magnet head-first, lying supine. The SPV direction reversed when entering feet-first. Pitching chin-to-chest caused subjects to reach a null point for horizontal SPV. Right unilateral vestibular hypofunction (UVH) subjects developed slow-phase-up nystagmus and left UVH subjects, slow-phase-down nystagmus. Vertical and torsional components were consistent with superior semicircular canal excitation or inhibition, respectively, of the intact ear. These findings provide compelling support for the hypothesis that MVS is a result of a Lorentz force and suggest that the function of individual structures within the labyrinth can be assessed with MVS. As a novel method of comfortable and sustained labyrinthine stimulation, MVS can provide new insights into vestibular physiology and pathophysiology. PMID:24659983

  17. Unilateral retinopathy secondary to occult primary intraocular lymphoma

    PubMed Central

    Barile, Gaetano R.; Hood, Donald C.; Marr, Brian; Hussein, Shafinaz; Tsang, Stephen H.

    2014-01-01

    Purpose The purpose of the study is to report the clinical case of a 53-year-old woman whose presenting manifestation of primary intraocular lymphoma (PIOL) was unilateral retinal degeneration. Method A case report was created with review of clinical, imaging, electrophysiologic, and pathological investigations. Results A 53-year-old woman with a distant history of ocular herpes simplex developed progressive central visual loss and intermittent photopsia over 4 years in her right eye. Ophthalmic examination revealed reduced visual acuity OD, central scotoma, and minimal ocular findings. Autofluorescence and infrared imaging revealed mild reflectance changes in the temporal macula, and spectral-domain optical coherence tomography identified mild disruptions of inner segment/outer segment junctions in the subfoveal region of the right eye. A mild window defect was seen on fluorescein angiography. Electrophysiology with multifocal electroretinogram (ERG) revealed evidence of unilateral macular dysfunction. Full-field ERGs revealed progressive global retinal dysfunction over 6 months, with unilateral decreases in amplitude and implicit time shifts, as seen in cases of autoimmune retinopathies. The eye eventually exhibited mild vitreous cellular infiltration on ophthalmoscopic examination, and vitrectomy diagnosed B cell non-Hodgkin’s lymphoma. Further evaluation revealed no evidence of central nervous system or systemic disease, consistent with occult PIOL. Conclusions This case illustrates an atypical presentation of PIOL characterized by unilateral retinal disease presenting with symptoms and signs of macular dysfunction. Clinical and ERG features evolved into an acute zonal occult outer retinopathy (AZOOR)-like phenotype. PIOL should be considered in atypical cases of AZOOR with vitreal reactions, and some cases of AZOOR may be related to B cell lymphocyte disorders. PMID:24081663

  18. Unilateral hearing during development: hemispheric specificity in plastic reorganizations

    PubMed Central

    Kral, Andrej; Heid, Silvia; Hubka, Peter; Tillein, Jochen

    2013-01-01

    The present study investigates the hemispheric contributions of neuronal reorganization following early single-sided hearing (unilateral deafness). The experiments were performed on ten cats from our colony of deaf white cats. Two were identified in early hearing screening as unilaterally congenitally deaf. The remaining eight were bilaterally congenitally deaf, unilaterally implanted at different ages with a cochlear implant. Implanted animals were chronically stimulated using a single-channel portable signal processor for two to five months. Microelectrode recordings were performed at the primary auditory cortex under stimulation at the hearing and deaf ear with bilateral cochlear implants. Local field potentials (LFPs) were compared at the cortex ipsilateral and contralateral to the hearing ear. The focus of the study was on the morphology and the onset latency of the LFPs. With respect to morphology of LFPs, pronounced hemisphere-specific effects were observed. Morphology of amplitude-normalized LFPs for stimulation of the deaf and the hearing ear was similar for responses recorded at the same hemisphere. However, when comparisons were performed between the hemispheres, the morphology was more dissimilar even though the same ear was stimulated. This demonstrates hemispheric specificity of some cortical adaptations irrespective of the ear stimulated. The results suggest a specific adaptation process at the hemisphere ipsilateral to the hearing ear, involving specific (down-regulated inhibitory) mechanisms not found in the contralateral hemisphere. Finally, onset latencies revealed that the sensitive period for the cortex ipsilateral to the hearing ear is shorter than that for the contralateral cortex. Unilateral hearing experience leads to a functionally-asymmetric brain with different neuronal reorganizations and different sensitive periods involved. PMID:24348345

  19. Sulfasalazine reduces inflammatory renal injury in unilateral ureteral obstruction

    Microsoft Academic Search

    Savas Demirbilek; Memet Hanefi Emre; Engin Nasuhi Ayd?n; Mehmet Naci Edali; Rauf Tu?rul Aksoy; Melih Ak?n; Kubilay Gürünlüo?lu; Erkan Tas; Selma Ay; Zümrüt Yilmaz

    2007-01-01

    The purpose of this study was to test whether sulfasalazine has a protective action against interstitial inflammation and\\u000a the development of renal fibrosis in obstructive nephropathy. Female rats were subjected to a sham (n?=?10) or unilateral ureteral obstruction (UUO, n?=?30). UUO was induced in rats by ligating the left ureter. Three days after operation, rats subjected to UUO were randomized

  20. Wms-r patterns among patients with unilateral brain lesions

    Microsoft Academic Search

    Gordon J. Chelune; Robert A. Bornstein

    1988-01-01

    The effects of unilateral brain lesions on memory functioning were examined among a sample of 115 patients with well lateralized lesions using the new Wechsler Memory Scale-Revised (WMS-R). Multivariate analysis of the WMS-R age-corrected summary indexes for the patients with right-(n = 56) and left-(n = 59) hemisphere lesions was significant (p<.008), although subsequent univariate comparisons revealed that only the

  1. Insufficient unilateral cerebral perfusion during emergent aortic arch surgery

    PubMed Central

    Urbanski, Paul P.; Babin-Ebell, Jörg; Fröhner, Steffen; Diegeler, Anno

    2012-01-01

    A rare case of insufficient right-sided unilateral cerebral perfusion during emergent aortic arch replacement in a patient with an acute aortic dissection is reported. On the basis of intraoperative monitoring using near-infrared spectroscopy, the insufficient perfusion of the contralateral hemisphere was detected and the bilateral perfusion was performed, which led to normalization of cerebral perfusion and an uncomplicated neurological outcome. PMID:22108941

  2. Unilateral retinal hemorrhages in documented cases of child abuse

    Microsoft Academic Search

    Arlene V Drack; Joseph Petronio; Antonio Capone

    1999-01-01

    PURPOSE:To describe the occurrence of unilateral retinal hemorrhages in four cases of documented child abuse, including a case in which retinal hemorrhages were an incidental finding on routine examination.METHODS:Case reports.RESULTS:Three children, 5 to 17 months of age, with suspected child abuse had fundus examinations with a dilated pupil as part of their evaluation. An additional child, 6 months of age,

  3. Fractures of the Fifth Metatarsal

    MedlinePLUS

    ... overlooked when they occur with an ankle sprain. Jones fracture . Jones fractures occur in a small area of the ... therefore more prone to difficulties in healing. A Jones fracture can be either a stress fracture (a ...

  4. Hydraulic Fracturing Sand

    USGS Multimedia Gallery

    Fine-grained silica sand is mixed with chemicals and water before being pumped into rock formations to prevent the newly created artificial fractures from closing after hydraulic fracturing is completed....

  5. Sprains, Strains and Fractures

    MedlinePLUS

    ... is actually a break in the bone. Causes Injuries are the most common causes of foot and ankle sprains and fractures. Many fractures and sprains occur during sports. Football players are particularly vulnerable to foot and ankle ...

  6. Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length 

    E-print Network

    Lolon, Elyezer P.

    2006-04-12

    be shorter due to fracture growth out of zone, improper proppant settling, or proppant flowback, short calculated fracture lengths can also result from incorrect analysis techniques. It is known that fracturing fluid that remains in the fracture and formation...

  7. Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length

    E-print Network

    Lolon, Elyezer P.

    2006-04-12

    be shorter due to fracture growth out of zone, improper proppant settling, or proppant flowback, short calculated fracture lengths can also result from incorrect analysis techniques. It is known that fracturing fluid that remains in the fracture and formation...

  8. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-06-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  9. Hydraulic fracture design optimization

    SciTech Connect

    Advani, S.H.; Lee, T.S. [Lehigh Univ., Bethlehem, PA (United States)

    1992-05-01

    This research and development investigation, sponsored by U.S. DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applies energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  10. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-01-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  11. Simultaneous hydraulic fracturing

    Microsoft Academic Search

    Uhri

    1989-01-01

    A process is described for simultaneous hydraulic fracturing of a hydrocarbonaceous fluid-bearing formation comprising: (a) determining a hydraulic pressure necessary to fracture the formation from at least two wells which penetrate the formation; (b) injecting a hydraulic fracturing fluid into both wells under the determined hydraulic pressure; and (c) applying simultaneously the determined hydraulic pressure to the hydraulic fluid contained

  12. Relative Permeability Through Fractures

    E-print Network

    Stanford University

    SGP-TR-170 Relative Permeability Through Fractures Gracel P. Diomampo August 2001 Financial support, California #12;#12;v Abstract The mechanism of two-phase flow through fractures is of importance in understanding many geologic processes. Currently, two-phase flow through fractures is still poorly understood

  13. OSTEOPOROTIC FRACTURES ghouling facts

    E-print Network

    Squire, Larry R.

    10/20/2011 1 OSTEOPOROTIC FRACTURES ghouling facts Maureen Benetti NP OSTEOPOROSIS · "Osteo" means architecture normal osteoporotic OSTEOPOROSIS · Leads to fragile bone and an increased risk of fracture #12;10/20/2011 2 OSTEOPOROSIS · Asymptomatic · Most common metabolic bone disease in the developed world · Fracture

  14. Creation of multiple sequential hydraulic fractures via hydraulic fracturing combined with controlled pulse fracturing

    Microsoft Academic Search

    Uhri

    1988-01-01

    A method for creating multiple sequential hydraulic fractures via hydraulic fracturing combined with controlled pulse fracturing is described comprising: (a) creating more than two simultaneous multiple vertical radial fractures via a controlled pulse fracturing method; (b) applying thereafter hydraulic pressure to the formation in an amount sufficient to fracture; (c) maintaining the hydraulic pressure on the formation while pumping alternate

  15. Unilateral divorce versus child custody and child support in the U.S

    Microsoft Academic Search

    2012-01-01

    â–º We explore the response of the divorce rate to unilateral divorce reforms. â–º We control for joint custody regime and the Child Support Enforcement program. â–º They counteract the allocation of rights generated by the unilateral divorce. â–º We do not find a reverse response of divorce rates to the unilateral divorce. â–º The decline in divorce rates is

  16. Midterm outcome after unilateral approach for bilateral decompression of lumbar spinal stenosis: 5-year prospective study

    Microsoft Academic Search

    Halit Çavu?o?lu; Ramazan Alper Kaya; Osman Nuri Türkmenoglu; Cengiz Tuncer; ?brahim Çolak; Yunus Ayd?n

    2007-01-01

    The aim of our study is to evaluate the results and effectiveness of bilateral decompression via a unilateral approach in\\u000a the treatment of degenerative lumbar spinal stenosis. We have conducted a prospective study to compare the midterm outcome\\u000a of unilateral laminotomy with unilateral laminectomy. One hundred patients with 269 levels of lumbar stenosis without instability\\u000a were randomized to two treatment

  17. [Prosthetic rehabilitation of unilateral anakusis. Study with stereoaudiometry].

    PubMed

    Vaneecloo, F M; Hanson, J N; Laroche, C; Vincent, C; Dehaussy, J

    2000-12-01

    We studied the clinical and stereoaudiometric results in two patients with unilateral anakusis who were rehabilitated with a bone-transmission prosthesis (B.A.H.A.) on the deaf side. Clinically, both patients improved considerably, recovering their capacity to communicate, particularly in a noisy environment. Sound localization tests demonstrated that the sound source was not precisely localized in space. Inversely, the spatial discrimination tests and the multidirectional tests showed an important improvement in comprehension of speech, particularly in the dead space of the defective hemifield. This recovery was certainly related to improved perception of high frequencies via intracranial transmission enabled by the prosthesis. PMID:11148346

  18. Subdural empyema and unilateral pansinusitis due to a tooth infection.

    PubMed

    Derin, Serhan; Sahan, Murat; Hazer, Derya Burcu; Sahan, Leyla

    2015-01-01

    Paranasal sinus infections are very common. Dental infections, tumours and anatomical malformations can cause unilateral sinusitis. Most cases can be treated without complications. However, rare life-threatening intracranial complications can occur. Generally, an intracranial complication progresses rapidly and can cause meningismus, focal neurological disorders, loss of consciousness and seizures. In such cases, an emergency craniotomy and concurrent sinus surgery are required. This article presents a 16-year-old patient with pansinusitis and subdural empyema that developed after a dental abscess. PMID:26123452

  19. Brooke-Spiegler syndrome complicated by unilateral hearing loss.

    PubMed

    Parren, Lizelotte J M T; Bauer, Boris; Hamm, Henning; Frank, Jorge

    2008-11-01

    Brooke-Spiegler syndrome is an autosomal dominant tumor predisposition disorder. The disease is characterized by the occurrence of multiple skin appendage tumors, including cylindroma, trichoepithelioma, and spiradenoma. In some patients, tumors cover the entire head circumference, thereby causing disfigurement and other complications. Here, we report on a man with multiple cylindroma that were distributed in a turban tumor-like fashion. One of these neoplasms arose in the meatus externus of the right ear leading to unilateral hearing loss, a complication that has been documented only on few occasions in this disease. PMID:18986490

  20. Parinaud's syndrome due to an unilateral vascular ischemic lesion.

    PubMed

    Serino, Josefina; Martins, João; Páris, Liliana; Duarte, Ana; Ribeiro, Isabel

    2015-04-01

    A 59-year-old man who complained of binocular vertical diplopia after an exploratory laparotomy, complicated by cardiorespiratory arrest during anesthetic induction, was found to have Collier's sign, anisocoria, complete paralysis of upward vertical gaze associated with convergence-retraction nystagmus on attempted upgaze and skew deviation with hypertropia in the left eye without ptosis, and an absent Bielschowsky sign. Magnetic resonance imaging of the brain showed a small lesion in the left paramedian midbrain compatible with microvascular ischemic sequelae. This patient was diagnosed with Parinaud's syndrome (dorsal midbrain syndrome) associated with a vertical strabismus from an unilateral vascular ischemic paramedian midbrain lesion. PMID:25649259

  1. Unilateral rubral tremors in Wilson's disease treated with dimercaprol.

    PubMed

    Chakor, Rahul T; Bharote, Haresh; Eklare, Nishikant; Tamboli, Khansabegum

    2015-01-01

    Tremors are reported as the most frequent neurological manifestation of Wilson's disease (WD) in some series. Postural tremors, rest tremors, action tremors and wing-beating (rubral) tremors are the different types of tremors seen in WD. We report a patient of WD with unilateral rubral tremors refractory to 1-year therapy with Penicillamine and anti-tremor medications. The tremors decreased considerably after adding chelation therapy with dimercaprol. Combination of Penicillamine and dimercaprol is an effective decoppering measure in rubral tremors of WD. PMID:25745328

  2. Unilateral coronal craniosynostosis in Abraham Lincoln and his family.

    PubMed

    Fishman, Ronald S

    2010-09-01

    Premature closure of one coronal skull suture produces a characteristic arching or relative elevation of the superior orbital rim on the involved side. This sign is associated with facial asymmetry, and both signs are usually the most conspicuous features in patients with mild unilateral coronal craniosynostosis. Photographs suggest that at least 9 individuals over 5 generations of the Abraham Lincoln family had premature closure of 1 coronal suture. In 8 males, there was involvement of the left side; in 1 female, there was involvement of the right side. PMID:20856045

  3. Primary sinonasal tuberculosis confined to the unilateral maxillary sinus

    PubMed Central

    Kim, Kyung Yeon; Bae, Jung Ho; Park, Jee Soo; Lee, Seung-Sin

    2014-01-01

    Extrapulmonary tuberculosis is not rare and occurs mainly in the head and neck region. Cervical tuberculous lymphadenopathy is the most common form of extrapulmonary tuberculosis. Sinonasal tuberculosis is known to occur very rarely due to the protective functions of sinonasal mucosa. Although some signs of sinonasal tuberculosis may be present, such as associated facial abscesses, the symptoms and signs are usually nonspecific. Clinical suspicion is important for timely diagnosis and proper management of sinonasal tuberculosis due to its rarity and nonspecific clinical presentation. We report a case of tuberculosis confined to the unilateral maxillary sinus that was first misdiagnosed as recurrent rhinosinusitis after endoscopic sinus surgery. PMID:24551309

  4. Surgical correction of unilateral and bilateral facial palsy

    PubMed Central

    Harrison, D

    2005-01-01

    Unilateral and bilateral facial palsies are debilitating and depressing conditions for the patient. For the past 30 years attempts have been made to improve the reanimation of these patients. The ability to transfer axons over significant distances with nerve grafts and the transfer of muscle that can be revascularised by microvascular surgery greatly improves results of this surgery. The revascularisation of muscle has been the important step forward but the re-focusing of interest in this condition has brought about a number of peripheral advances. PMID:16143684

  5. Hydraulic fracture geometry: fracture containment in layered formations

    Microsoft Academic Search

    van Eekelen

    1982-01-01

    One of the main problems in hydraulic fracturing technology is the prediction of fracture height. In particular, the question of what constitutes a barrier to vertical fracture propagation is crucial to the success of field operations. An analysis of hydraulic fracture containment effects has been performed. The main conclusion is that in most cases the fracture will penetrate into the

  6. Hydraulic fracturing method to control vertical fracture heights

    Microsoft Academic Search

    J. L. Fitch; L. Masse; W. L. Medlin; M. A. Biot

    1974-01-01

    A method of hydraulically fracturing a subterranean earth formation to form a vertically disposed fracture is described. More particularly, the method controls the height of the vertically disposed fracture such that the fracture does not extend into formations that are adjacent to the target formation. Hydraulic pressure is applied via a well to the formation to initiate a vertical fracture

  7. Fracture corridors in carbonates

    NASA Astrophysics Data System (ADS)

    Chatelée, Sébastien; Lamarche, Juliette; Gauthier, Bertrand D. M.

    2015-04-01

    Among fractures, Fracture Corridors (FC) are anomalous structures made of highly persistent fracture clusters having a strong effect on multi-phase fluid flow in the subsurface. While mechanical and geological conditions for diffuse fracture systems are well constrained, FC genetic conditions remain a matter of questioning. FC can be localized in larger structures such as folds and fault zones but recent studies suggest that a large amount of fractures and FC also arise as distributed in the host rock and formed in tabular layers during burial with early rock mechanical differentiation. In addition, while the mechanical stratigraphy is of prime importance for fracture stratigraphy, it is still unknown which factor prevails on FC genesis among the local versus regional stress-state, the host rock mechanical stratigraphy or the sedimentary facies. We present a study of fractures in a 400×300 m wide quarry (Calvisson, SE France) dug in homogeneous marly limestones of Hauterivian age. The quarry exhibits diffuse fractures as well as 16 FC. The aim of this study is to reveal the genetics factor for FC development, their global geometry and internal morphologic variations, but also to clear the impact of fracture corridors on diffuse fracture. For that, we measured >2500 fractures (strike, dip, spacing, filling, aperture, etc.) and studied microstructures in 80 thin sections. We calculated fracture density and acquired LiDAR data with >90 million points with a resolution of 4 to 15mm. Diffuse fractures are organized as two perpendicular sets, a main set NE-SW-trending and minor set NW-SE-trending. The FC have the same trend, but the NW-SE trend prevail on the NE-SW one. The LiDAR acquisition allows to visualize the 3D lateral continuity with corridors with a minimal extension of 30m. We distinguish 4 internal morphologic types in FC, depending on fracture morphology, occurrence of breccia and number of zones. The types may occur in a single FC with a lateral transition from one type to another. Fracture density study shows that diffuse fracture increase around FC. FC growth and variability was not dependent on facies variations, as they are inexistent in the quarry. The result of this study allows to interpret geomechanical behaviors and geological history of fractures and fracture corridors in carbonates.

  8. Fractures after antiretroviral initiation

    PubMed Central

    Yin, Michael T.; Kendall, Michelle A.; Wu, Xingye; Tassiopoulos, Katherine; Hochberg, Marc; Huang, Jeannie S.; Glesby, Marshall J.; Bolivar, Hector; McComsey, Grace A.

    2013-01-01

    Background Bone mineral density declines by 2–6% within 1–2 years after initiation of antiretroviral therapy (ART); however, it is uncertain whether this results in an immediate or cumulative increase in fracture rates. Methods We evaluated the incidence and predictors of fracture in 4640 HIV-positive participants from 26 randomized ART studies followed in the AIDS Clinical Trials Group (ACTG) Longitudinal-Linked Randomized Trial study for a median of 5 years. Fragility and nonfragility fractures were recorded prospectively at semiannual visits. Incidence was calculated as fractures/total person-years. Cox proportional hazards models evaluated effects of traditional fracture risks, HIV disease characteristics, and ART exposure on fracture incidence. Results Median (interquartile range) age was 39 (33, 45) years; 83% were men, 48% white, and median nadir CD4 cell count was 187 (65, 308) cells/?l. Overall, 116 fractures were reported in 106 participants with median time-to-first fracture of 2.3 years. Fracture incidence was 0.40 of 100 person-years among all participants and 0.38 of 100 person-years among 3398 participants who were ART naive at enrollment into ACTG parent studies. Among ART-naive participants, fracture rates were higher within the first 2 years after ART initiation (0.53/100 person-years) than subsequent years (0.30/100 person-years). In a multivariate analysis of ART-naive participants, increased hazard of fracture was associated with current smoking and glucocorticoid use but not with exposure to specific antiretrovirals. Conclusion Fracture rates were higher within the first 2 years after ART initiation, relative to subsequent years. However, continuation of ART was not associated with increasing fracture rates in these relatively young HIV-positive individuals. PMID:22951635

  9. Unilateral nerve injury produces bilateral loss of distal innervation.

    PubMed

    Oaklander, Anne Louise; Brown, Jennifer M

    2004-05-01

    There are no known anatomical connections between neurons that innervate homologous right and left body parts. Nevertheless, some patients develop bilateral abnormalities after unilateral injury, a phenomenon often unrecognized and not yet characterized. Therefore, we examined in rats the effects of ligating and cutting one tibial nerve on sensory function and on density of innervation in hind paws contralaterally as well as ipsilaterally to the injury, at times between 1 day and 5 months after surgery. Punches removed from tibial- or sural-innervated planter paw skin were immunolabeled to quantitate epidermal nerve endings. Naive and sham-operated rats provided controls. Axotomized rats had near-total loss of PGP9.5(+) innervation within ipsilateral tibial-innervated skin at all time-points. Adjacent ipsilateral sural-innervated skin had persistent hyperalgesia without denervation, and robust axonal sprouting at 5 months after surgery. Contralesional hind paws lost 54% of innervation in tibial-innervated epidermis starting 1 week after surgery and persisting throughout. Contralesional sural-innervated skin had neither neurite loss nor sprouting. These results imply that unilateral nerve injury can cause profound, long lasting, nerve-branch-specific loss of distal innervation contralaterally as well as ipsilaterally. They discredit the practice of using tissues contralateral to an injury to provide normative controls and suggest the possibility of rapid, transmedian postinjury signals between homologous mirror-image neurons. PMID:15122703

  10. Unilateral Altruism in Network Routing Games with Atomic Players

    E-print Network

    Azad, Amar Prakash

    2011-01-01

    We study a routing game in which one of the players unilaterally acts altruistically by taking into consideration the latency cost of other players as well as his own. By not playing selfishly, a player can not only improve the other players' equilibrium utility but also improve his own equilibrium utility. To quantify the effect, we define a metric called the Value of Unilateral Altruism (VoU) to be the ratio of the equilibrium utility of the altruistic user to the equilibrium utility he would have received in Nash equilibrium if he were selfish. We show by example that the VoU, in a game with nonlinear latency functions and atomic players, can be arbitrarily large. Since the Nash equilibrium social welfare of this example is arbitrarily far from social optimum, this example also has a Price of Anarchy (PoA) that is unbounded. The example is driven by there being a small number of players since the same example with non-atomic players yields a Nash equilibrium that is fully efficient.

  11. Unilateral peripheral neuropathic pain: The role of neurodiagnostic skin biopsy

    PubMed Central

    Buonocore, Michelangelo

    2014-01-01

    According to the current definition of neuropathic pain (“pain arising as a direct consequence of a lesion or disease affecting the somatosensory system”), the demonstration of a lesion or disease involving the somatosensory system is mandatory for the diagnosis of definite neuropathic pain. Although several methods are currently available for this aim, none is suitable for every type of disease (or lesion). Neurodiagnostic skin biopsy (NSB) is a relatively new technique for the diagnosis of peripheral nerve lesions. It is an objective method, completely independent from the patient’s complaining, based on immunohistochemical staining techniques that allow measurement of the density of the epidermal nerve fibers, currently considered the free nerve endings of small diameter (A-delta and C) afferent fibers. NSB has the important property of being used to investigate the skin, allowing obtaining a diagnosis of small fiber axonal neuropathy of peripheral nerves supplying every body part covered by skin. This feature appears to be very important, particularly in cases of unilateral nerve lesions, because it allows going beyond the possibilities of neurophysiological tests which are available only for a limited number of peripheral nerves. All these characteristics make NSB a precious instrument for the diagnosis of peripheral unilateral neuropathic pain. PMID:24579067

  12. Orbital Wall Restoring Surgery in Pure Blowout Fractures

    PubMed Central

    Lim, Nam Kyu; Oh, Sang Ah; Gu, Ja Hea

    2014-01-01

    Background Restoring orbital volume in large blowout fractures is still a technically challenge to the orbital surgeon. In this study, we restored the orbital wall using the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses, and we compared the surgical outcome to that of a conventional transorbital method. Methods A retrospective review of all patients with pure unilateral blowout fractures between March 2007 and March 2013 was conducted. 150 patients were classified into two groups according to the surgical method: conventional transorbital method (group A, 75 patients, control group), and the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses (group B, 75 patients, experimental group). Each group was subdivided depending on fracture location: group I (inferior wall), group IM (inferomedial wall), and group M (medial wall). The surgical results were assessed by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR) values. Results In the volumetric analysis, the OVR decreased more by the experimental groups than each corresponding control groups (P<0.05). Upon ophthalmic examination, neither the differences among the groups in the perioperative Hertel scale nor the preoperative and postoperative Hertel scales were statistically significant (P>0.05). Conclusions Our surgical results suggest that orbital volume was more effectively restored by the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses than the conventional method, regardless of the type of fracture. PMID:25396181

  13. Formation stability after hydraulic fracturing

    Microsoft Academic Search

    Panos Papanastasiou

    1999-01-01

    This paper investigates stress changes resulting from fracturing in a weak formation and estimates the reduced risk of formation failure. The analysis is based on fracture propagation and closure of a plane strain elasto-plastic fracture. It is shown that during fracture propagation the area near the fracture tip undergoes plastic deformation, with the result that the in situ stresses there

  14. Hydraulic Fracture Containment in Sand

    Microsoft Academic Search

    Y. Dong

    2010-01-01

    The mechanism of hydraulic fracturing in soft, high permeability material is considered fundamentally different from that in hard, low permeability rock, where a tensile fracture is created and conventional linear elastic fracture mechanics (LEFM) applies. The fracturing and associated modeling work is then a relatively new area. Particularly, the fracture containment in layered formations remains unknown. This research is aiming

  15. Determinants of Autobiographical Memory in Patients with Unilateral Temporal Lobe Epilepsy or Excisions

    ERIC Educational Resources Information Center

    St-Laurent, Marie; Moscovitch, Morris; Levine, Brian; McAndrews, Mary Pat

    2009-01-01

    Patients with unilateral temporal lobe epilepsy from hippocampal origin and patients with unilateral surgical excision of an epileptic focus located in the medial temporal lobe were compared to healthy controls on a version of the Autobiographical Interview (AI) adapted to assess memory for event-specific and generic personal episodes. For both…

  16. Effect of monoclonal anti-ANP antibodies on the acute functional adaptation to unilateral nephrectomy

    Microsoft Academic Search

    Jean-Pierre Valentin; Jean Ribstein; Dominik Neuser; Jürg Nüssberger; Albert Mimran

    1993-01-01

    Effect of monoclonal anti-ANP antibodies on the acute functional adaptation to unilateral nephrectomy. The role of endogenous atrial natriuretic peptide (ANP) in the immediate response of sodium excretion to unilateral nephrectomy (UNX) was investigated in anesthetized euvolemic rats through measurement of UNX-induced change in plasma ANP concentration and the response of the remaining kidney to UNX following administration of monoclonal

  17. Effects of eccentrically and concentrically induced unilateral fatigue on the involved and uninvolved limbs

    Microsoft Academic Search

    Mark D Grabiner; Tammy M Owings

    1999-01-01

    This study extended findings of others related to the fatigue resistance of maximum voluntary knee extension contractions performed eccentrically on an isokinetic dynamometer. Twelve subjects performed either 75 unilateral isokinetic concentric MVCs or 75 unilateral isokinetic eccentric MVCs at 30°s?1. A uniquely-configured dynamometer provided the opportunity to describe the effect of the concentric or eccentric fatigue protocol on the concentric

  18. Smad3 deficiency attenuates renal fibrosis, inflammation,and apoptosis after unilateral ureteral obstruction

    Microsoft Academic Search

    KUMI INAZAKI; YUTAKA KANAMARU; YUKO KOJIMA; NORIYOSHI SUEYOSHI; KO OKUMURA; KAZUNARI KANEKO; YUICHIRO YAMASHIRO; HIDEOKI OGAWA; ATSUHITO NAKAO

    2004-01-01

    Smad3 deficiency attenuates renal fibrosis, inflammation, and apoptosis after unilateral ureteral obstruction.BackgroundTransforming growth factor-? (TGF-?) has been implicated in the development of renal fibrosis induced by unilateral ureteral obstruction (UUO). However, there is little information on signaling pathways mediating TGF-? activity involved in molecular and cellular events leading to renal fibrosis induced by UUO. In this study, we sought to

  19. Identifying Live Nematodes in Diffuse Unilateral Subacute Neuroretinitis by Using the Scanning Laser Ophthalmoscope

    Microsoft Academic Search

    Lucio R. Moraes; Arnaldo P. Cialdini; Marcos P. Avila; Ann E. Elsner

    2002-01-01

    Objective: To describe use of the scanning laser oph- thalmoscope (SLO) to identify live nematodes in patients with diffuse unilateral subacute neuroretinitis. Methods: Infrared, red, and blue illumination (780, 633, and 488 nm, respectively) in an SLO were used to image and evaluate functional retinal status in patients with late- stage diffuse unilateral subacute neuroretinitis. An ex- amination to identify

  20. Unilateral mydriasis secondary to ipratropium bromide in a critically ill patient

    PubMed Central

    Santana-Cabrera, Luciano; Fernández-Tagarro, Ernesto José; del Amo-Nolasco, Beatriz; Jaén-Sánchez, Nieves; Cáceres-Agra, Juan José

    2012-01-01

    Unilateral dilated pupil in a critical patient under sedation is an important clinical sign that requires prompt evaluation. An exhaustive assessment must be performed, including neurological examination and imaging tests, and pharmacological causes must be ruled out. We describe a case of unilateral fixed dilated pupil secondary to the administration of a nebulized cholinergic antagonist, ipratropium bromide, in an unconscious patient. PMID:22787356

  1. Motor Learning of a Bimanual Task in Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Hung, Ya-Ching; Gordon, Andrew M.

    2013-01-01

    Children with unilateral cerebral palsy (CP) have been shown to improve their motor performance with sufficient practice. However, little is known about how they learn goal-oriented tasks. In the current study, 21 children with unilateral CP (age 4-10 years old) and 21 age-matched typically developed children (TDC) practiced a simple bimanual…

  2. Fracture characterization from attenuation of Stoneley waves across a fracture

    E-print Network

    Bakku, Sudhish Kumar

    2012-01-01

    Fractures contribute significantly to the permeability of a formation. It is important to understand the fracture distribution and fluid transmissivity. Though traditional well logs can image fractures intersecting the ...

  3. Simulation of Hydraulic Fractures and their Interactions with Natural Fractures 

    E-print Network

    Sesetty, Varahanaresh

    2012-10-19

    Modeling the stimulated reservoir volume during hydraulic fracturing is important to geothermal and petroleum reservoir stimulation. The interaction between a hydraulic fracture and pre-existing natural fractures exerts significant control...

  4. Quantized fracture mechanics

    Microsoft Academic Search

    Nicola M. Pugno; Rodney S. Ruoff

    2004-01-01

    A new energy-based theory, quantized fracture mechanics (QFM), is presented that modifies continuum-based fracture mechanics; stress- and strain-based QFM analogs are also proposed. The differentials in Griffith's criterion are substituted with finite differences; the implications are remarkable. Fracture of tiny systems with a given geometry and type of loading occurs at ‘quantized’ stresses that are well predicted by QFM: strengths

  5. Quantized fracture mechanics

    Microsoft Academic Search

    Nicola M. Pugno; Rodney S. Ruoff

    2004-01-01

    A new energy-based theory, quantized fracture mechanics (QFM), is presented that modifies continuum-based fracture mechanics; stress- and strain-based QFM analogs are also proposed. The differentials in Griffith's criterion are substituted with finite differences; the implications are remarkable. Fracture of tiny systems with a given geometry and type of loading occurs at 'quantized' stresses that are well predicted by QFM: strengths

  6. Dynamic quantized fracture mechanics

    Microsoft Academic Search

    N. M. Pugno; R. S. Ruoff

    2006-01-01

    A new quantum action-based theory, dynamic quantized fracture mechanics (DQFM), is presented that modifies continuum-based\\u000a dynamic fracture mechanics (DFM). The crack propagation is assumed as quantized in both space and time. The static limit case\\u000a corresponds to quantized fracture mechanics (QFM), that we have recently developed to predict the strength of nanostructures.\\u000a DQFM predicts the well-known forbidden strength and crack

  7. Natural fracture systems studies

    SciTech Connect

    Lorenz, J.C.; Warpinski, N.R.

    1992-09-01

    The objectives of this program are (1) to develop a basinal-analysis methodology for natural fracture exploration and exploitation, and (2) to determine the important characteristics of natural fracture systems for use in completion, stimulation, and production operations. Natural-fracture basinal analysis begins with studies of fractures in outcrop, core and logs in order to determine the type of fracturing and the relationship of the fractures to the lithologic environment. Of particular interest are the regional fracture systems that are pervasive in western US tight sand basins. A Methodology for applying this analysis is being developed, with the goal of providing a structure for rationally characterizing natural fracture systems basin-wide. Such basin-wide characterizations can then be expanded and supplemented locally, at sites where production may be favorable. Initial application of this analysis is to the Piceance basin where there is a wealth of data from the Multiwell Experiment (MWX), DOE cooperative wells, and other basin studies conducted by Sandia, CER Corporation, and the USGS (Lorenz and Finley, 1989, Lorenz et aI., 1989, and Spencer and Keighin, 1984). Such a basinal approach has been capable of explaining the fracture characteristics found throughout the southern part of the Piceance basin and along the Grand Hogback.

  8. Quantized fracture mechanics

    NASA Astrophysics Data System (ADS)

    Pugno, Nicola M.; Ruoff, Rodney S.

    2004-09-01

    A new energy-based theory, quantized fracture mechanics (QFM), is presented that modifies continuum-based fracture mechanics; stress- and strain-based QFM analogs are also proposed. The differentials in Griffith's criterion are substituted with finite differences; the implications are remarkable. Fracture of tiny systems with a given geometry and type of loading occurs at 'quantized' stresses that are well predicted by QFM: strengths predicted by QFM are compared with experimental results on carbon nanotubes, ?-SiC nanorods, ?-Si3N4 whiskers, and polysilicon thin films; and also with molecular mechanics/dynamics simulation of fracture of carbon nanotubes and graphene with cracks and holes, and statistical mechanics-based simulations on fracture of two-dimensional spring networks. QFM is self-consistent, agreeing to first-order with linear elastic fracture mechanics (LEFM), and to second-order with non-linear fracture mechanics (NLFM). For vanishing crack length QFM predicts a finite ideal strength in agreement with Orowan's prediction. In contrast to LEFM, QFM has no restrictions on treating defect size and shape. The different fracture Modes (opening I, sliding II and tearing III), and the stability of the fracture propagations, are treated in a simple way.

  9. Bovine Mandibular Fractures

    PubMed Central

    Trent, A. M.; Ferguson, J. G.

    1985-01-01

    A retrospective study of bovine mandibular fractures was conducted. An increased incidence in males, beef breeds and animals less than one year of age was identified when the study group of 17 was compared to the total bovine case load. Manipulation during dystocia was the most common cause of fractures. Four neonates had rostral mandibular fractures. Fractures caudal to or involving the premolars were restricted to animals over a year of age. Treatment was attempted in ten of the seventeen cases, with euthanasia or slaughter elected in the remaining seven cases. Of the five cases treated by internal fixation, all four neonates died from conditions related to septicemia. PMID:17422602

  10. Unilateral cross bite treated by corticotomy-assisted expansion: two case reports

    PubMed Central

    2010-01-01

    Background True unilateral posterior crossbite in adults is a challenging malocclusion to treat. Conventional expansion methods are expected to have some shortcomings. The aim of this paper is to introduce a new technique for treating unilateral posterior crossbite in adults, namely, corticotomy-assisted expansion (CAE) applied on two adult patients: one with a true unilateral crossbite and the other with an asymmetrical bilateral crossbite, both treated via modified corticotomy techniques and fixed orthodontic appliances. Methods Two cases with asymmetric maxillary constriction were treated using CAE. Results In both cases, effective asymmetrical expansion was achieved using CAE, and functional occlusion was established as well. Conclusions Unilateral CAE presents an effective and reliable technique to treat true unilateral crossbite. PMID:20482859

  11. Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length

    Microsoft Academic Search

    Elyezer P. Lolon

    2004-01-01

    Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may be shorter due to fracture growth out of zone, improper proppant settling, or proppant flowback, short calculated fracture lengths can also result from incorrect

  12. Fracture After Total Hip Replacement

    MedlinePLUS

    ... American Academy of Orthopaedic Surgeons. • Dislocation • Limb length inequality • Poor fracture healing • Repeat fracture • Lack of in- ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Fracture A er Total ...

  13. Apparatus for unilateral generation of a homogeneous magnetic field

    DOEpatents

    Fukushima, E.; Rath, A.R.; Roeder, S.B.W.

    1984-05-01

    An apparatus for unilaterally producing a substantially homogeneous magnetic field. The apparatus includes two circular electromagnet coils, a small coil and a large coil, which are coaxial with one another and which are separated by a distance equal to one-half the difference in the radius of the two coils. By appropriate selection of electrical currents, which are passed through the coils in opposite directions, a region of homogeneous magnetic field is formed. This region is centered on the common axis of the two coils, at a point on the axis which is at a distance from the small coil equal to one-half the radius of the small coil, and which is on the opposite side of the small coil from the large coil. The apparatus has particular application in the field of diagnostic medical NMR and other NMR applications.

  14. Apparatus for unilateral generation of a homogeneous magnetic field

    DOEpatents

    Fukushima, Eiichi (Los Alamos, NM); Rath, Alan R. (San Diego, CA); Roeder, Stephen B. W. (La Mesa, CA)

    1988-01-01

    An apparatus for unilaterally producing a substantially homogeneous magnetic field. The apparatus includes two circular electromagnet coils, a small coil and a large coil, which are coaxial with one another and which are separated by a distance equal to one-half the difference in the radius of the two coils. By appropriate selection of electrical currents, which are passed through the coil in opposite directions, a region of homogeneous magnetic field is formed. This region is centered on the common axis of the two coils, at a point on the axis which is at a distance from the small coil equal to one-half the radius of the small coil, and which is on the opposite side of the small coil from the large coil. The apparatus has particular application in the field of diagnostic medical NMR and other NMR applications.

  15. Early cavernous sinus thrombosis following unilateral pansinusitis in a child.

    PubMed

    Mallick, Ajay; Pathak, Som Dutt; Shankar, Sandeep; Sati, Alok

    2015-01-01

    Cavernous sinus thrombosis (CST) is a life-threatening entity with a high rate of mortality and lifelong morbidity. A strong clinical suspicion of the complication, early radiological detection and institution of timely, aggressive treatment are required to prevent permanent neurological disability. We present a 12-year-old girl with bilateral CST following unilateral pansinusitis. Clinical symptoms of headache and retro-orbital pain out of proportion to clinical signs on presentation prompted a suspicion of something beyond sinusitis and raised the clinical suspicion of cavernous sinus involvement. In spite of institution of an early medical treatment, she progressed to develop bilateral cranial nerve paresis. However, with the persistence of antibiotics and anticoagulation therapy, she was successfully managed with no residual neurological sequelae. The aim of this presentation is to highlight the grave consequences of cavernous sinus involvement following infections of paranasal sinus and the rare complete recovery from disability in this case. PMID:25917067

  16. Horizontal sound localization skills of unilaterally hearing-impaired children.

    PubMed

    Humes, L E; Allen, S K; Bess, F H

    1980-01-01

    The present study assessed the horizontal sound localization skills of three groups of subjects; normal-hearing adults, normal-hearing children, and unilaterally hearing-impaired children. The ability of these subjects to localize pure tones to 500 and 3000 Hz in quiet and in a background of cafeteria noise was evaluated using an array of thirteen loudspeakers mounted in a large anechoic chamber. Results indicated a significant effect of signal frequency in all three groups of listeners. In addition, the hearing-impaired children performed significantly poorer than their normal-hearing counterparts in all conditions. Individual differences in sound localization ability among the hearing-impaired listeners could be explained largely through effects of age and degree of hearing impairment. PMID:7425955

  17. Unilateral spiny hyperkeratosis: case report and review of the literature.

    PubMed

    Mevorah, Baruch; Gat, Andrea; Golan, Haim; Brenner, Sarah

    2008-01-01

    We describe the first case of unilateral spiny hyperkeratosis (SH) of the left hand, review the literature and discuss possible patho- mechanisms. SH can be sporadic or familial, often appearing in healthy individuals. However, there is an association with various malignancies in a significant number of the sporadic cases. Although there is no satisfactory explanation of this association, we agree with previous authors that a patient with SH appearing in adult life should be evaluated and followed for the presence of malignancy. Other patients with SH may suffer from a variety of nonmalignant diseases, which may be coincidental or causally related. SH is not a premalignant lesion of the skin and should not be confused with porokeratosis which has a malignant potential. Except for excision of individual lesions, there is no permanent cure. PMID:18577857

  18. Anterior decompression in the management of unilateral cervical spondylotic amyotrophy.

    PubMed

    Zhang, Jing Tao; Yang, Da Long; Shen, Yong; Zhang, Ying Ze; Wang, Lin Feng; Ding, Wen Yuan

    2012-12-01

    Cervical spondylotic amyotrophy is a rare clinical condition. The purpose of this study was to investigate the effects of anterior decompression in patients with unilateral upper-extremity amyotrophy caused by cervical spondylosis. The authors retrospectively analyzed the records of 31 patients (23 men and 8 women) who underwent anterior decompressive surgery for cervical spondylotic amyotrophy at the authors' institution between 2000 and 2011. Demographic characteristics, pre- and postoperative results of imaging studies, and postoperative muscle power improvement were reviewed at a mean follow-up of 22.2 months (range, 14-36 months). Patients were divided into proximal (n=21) and distal (n=10) types according to the most severely atrophic muscle, and the 2 groups were compared statistically. The most commonly affected intervertebral level in proximal-type patients was C4-C5, whereas that in distal-type patients was C5-C6. Impingements against the ventral nerve root and anterior horn were observed in 22 and 25 cases, respectively, with 16 cases having both impingements. Eighty-one percent of proximal-type patients gained 1 or more grades of muscle power improvement on manual muscle testing, whereas 40% of distal-type patients improved. Within 15 postoperative days, 57% of proximal-type patients attained subjective or objective improvement of muscle power, whereas all distal-type patients failed to improve. Anterior decompression was effective for most patients with unilateral cervical spondylotic amyotrophy, although postoperative muscle power improvement in distal-type patients was inferior to that in proximal-type patients. Furthermore, compared with the proximal type, the distal type showed a slower postoperative recovery. PMID:23218638

  19. Radioimmunoassay of inhibin: serum responses to unilateral and bilateral orchidectomy

    SciTech Connect

    Schanbacher, B.

    1988-11-01

    An overnight double antibody RIA using a rabbit antiserum to porcine inhibin alpha-chain (Tyr30) (1-30) NH2 (pI alpha(1-30)), radioiodinated pI alpha(1-30), and a preprecipitated second antibody complex has been developed to measure inhibin concentrations in sera and other biological fluids. The assay is accurate, precise (intraassay coefficient of variation, 4.8%), sensitive (25 pM; 2.5 fmol/tube), and specific for inhibin. The synthetic reference standard pI alpha(1-30) produced a displacement curve that paralleled intact male ovine and bovine sera, crude bovine follicular fluid, and a partially purified porcine follicular fluid reference preparation (WHO/NIH 86/690). Bilateral castration of prepubertal and postpubertal ram lambs resulted in a rapid decrease in serum inhibin concentrations and a subsequent increase in serum FSH. Inhibin levels were high in prepubertal lambs (approximately 375 pM), but these levels were not sustained near the time of puberty (approximately 180 pM). Intensive sampling by jugular venipuncture after castration indicated a 50% drop in circulating inhibin levels within 2 h of testes removal with chronic castrate levels (approximately 75 pM) achieved by 6 h postcastration. A rapid fall in circulating levels of inhibin was also observed after unilateral castration, but these values stabilized within hours to levels intermediate (i.e. approximately 200 pM) to those of intact and bilateral castrate rams. Hemicastrates exhibited a more subtle rise in serum FSH after testis removal, with FSH and inhibin levels of prepubertal hemicastrates returning to mature intact ram values by 15 weeks of age. Serum inhibin levels remained low and FSH levels high at 14 days in unilateral castrate postpubertal rams. Inhibin immunoreactivity increased abruptly in castrate ewes and rams injected iv with 5 ml bovine follicular fluid.

  20. Avulsion fractures in athletes.

    PubMed Central

    Orava, S.; Ala-Ketola, L.

    1977-01-01

    34 cases of avulsion fractures are described. Each fracture took place during athletic training or competition. Excepting six sportsmen participating in a general fitness programme, every patient was an active competitive athlete. There were six women and 28 men; their average age was 20.1 years, raised by a few middle-aged "fitness sportsmen". Most avulsion fractures took place in sprinters and hurdlers; next were middle and long distance renner, footballers, fitness joggers, skiers and ice-hockey players. The most usual location of a fracture was the anterior pelvic spines; avulsion fractures were also detected in various parts of lower limbs. There were fewer avulsion fractures in the area of the trunk and upper extremities. Roetgenologically, the diagnosis of an avulsion fracture is generally easy to make. However, the diagnosis is facilitated by knowing the mechanism of the injury, the technique of the athletic event, and some of the training methods. Generally, a fracture heals well, even if it requires both sufficient immobilisation and some delay in resuming physical exertion. PMID:884433

  1. Fracture of glass

    NASA Technical Reports Server (NTRS)

    Henshaw, John M.

    1993-01-01

    The objectives of this educational exercise are the following: to observe and understand the fracture behavior of a brittle material; and to quantify the effects of various treatments on that material designed to modify its strength. A brief introduction to beam bending, fracture mechanics, influence of surface defects, residual stress, and static fatigue is presented. A test procedure for specimen testing is also presented.

  2. Dynamic fracture of ceramics

    Microsoft Academic Search

    J. Buchar; S. Rolc

    2006-01-01

    The aim of the paper consists in the comparison of two experimental methods which are used for the study of the ceramics fracture under dynamic loading. The experimental study has been performed for the specimen of the Al{2}O{3}. The loading has been performed using of the Taylor test. The impact velocity when the fracture of the specimen starts has been

  3. Anisotropic ductile fracture

    Microsoft Academic Search

    A. A Benzerga; J Besson; A Pineau

    2004-01-01

    Deformation and fracture are investigated at room temperature in steel through tension and compression tests. Round smooth bars and cylinders are used to characterize the deformation behavior while round notched bars are used to explore stress state and specimen orientation effects on fracture. The microstructure is characterized to infer initial average values of porosity, void aspect ratio and void spacing

  4. Osteoporotic fracture models.

    PubMed

    Simpson, A Hamish; Murray, Iain R

    2015-02-01

    Animal models are widely used to investigate the pathogenesis of osteoporosis and for the clinical testing of anti-resorptive drugs. However, osteoporotic fracture models designed to investigate novel ways to treat fractures of osteoporotic bone must fulfil requirements distinct from those of pharmacological testing. Bone strength and toughness, implant fixation and osteointegration and fracture repair are of particular interest. Osteoporotic models should reflect the underlying clinical scenario be that primary type 1 (post-menopausal) osteoporosis, primary type 2 (senile) osteoporosis or secondary osteoporosis. In each scenario, small and large animal models have been developed. While rodent models facilitate the study of fractures in strains specifically established to facilitate understanding of the pathologic basis of disease, concerns remain about the relevance of small animal fracture models to the human situation. There is currently no all-encompassing model, and the choice of species and model must be individualized to the scientific question being addressed. PMID:25388154

  5. Automated bone fracture detection

    NASA Astrophysics Data System (ADS)

    Donnelley, Martin; Knowles, Greg

    2005-04-01

    Fractures of bone are a common affliction. In most developed countries the number of fractures associated with age-related bone loss is increasing rapidly. Each year many fractures are missed during x-ray diagnosis, resulting in ineffective patient management and expensive litigation. From both an orthopaedic and radiologic point of view, the fully automatic detection and classification of fractures in long-bones is an important but difficult problem. In this paper, a fully automated method of detecting fractures in the diaphysis of a long-bone is described. X-rays are very difficult to process automatically, so to extract the required information a non-linear anisotropic diffusion method, the Affine Morphological Scale Space, was implemented to smooth the image without losing information about the location of boundaries within the image. Next, an iterative peak detection algorithm is used to accurately locate the bone centreline and articular surfaces. A method based on orthogonal projections calculated from a modified Hough transform is used to automatically locate the long-bone diaphysis. At this point, our algorithm accurately localises the area of the fracture, and would allow further image registration if necessary. Finally, a gradient-based algorithm is used to detect fractures present in the region of interest. The magnitude and direction of the gradient are combined to produce a measure of the likelyhood of the presence of a fracture. A library of long-bone fracture images was created. Experimental tests performed on a series of x-ray images show that the method is capable of accurately segmenting the diaphysis from the epiphyses, and is also able to detect many mid-shaft fractures of long-bones.

  6. Entrainment of circadian rhythms: retinofugal pathways and unilateral suprachiasmatic nucleus lesions.

    PubMed

    Donaldson, J A; Stephan, F K

    1982-12-01

    The role of retinohypothalamic input to the suprachiasmatic nuclei (SCN) as well as SCN afferents from the ventrolateral geniculate nuclei (LGNV) in the entrainment of circadian drinking rhythms was investigated in the rat. Bilateral lesions of the LGNV and the primary optic tracts had no affect on the entrainment of drinking rhythms to a light-dark cycle, the response to a 12 hr phase shift of the light-dark cycle, or on the period of the free-running circadian rhythm in constant light or constant darkness. Unilateral blinding in rats with or without LGNV lesions retarded the rate of phase shifting by 2 days and decreased the period of the free-running rhythm in constant light. For rats with unilateral SCN lesions, or such lesions combined with either ipsi- or contra-lateral blinding, the rate of re-entrainment was intermediate between intact and unilaterally blinded rats indicating that unilateral SCN lesions partially reversed the effects of unilateral blinding. Unilateral SCN lesions had no effect on the period of the free-running rhythm in constant light or darkness. These results are consistent with the interpretation that the asymmetrical innervation of the two SCN by the RHT in unilaterally blinded rats delays re-entrainment by changing the phase response curve of the circadian system. This change may be mediated by neural connections between the two SCN. PMID:7163396

  7. Comparison of weight changes following unilateral and staged bilateral STN DBS for advanced PD

    PubMed Central

    Lee, Eric M; Kurundkar, Ashish; Cutter, Gary R; Huang, He; Guthrie, Barton L; Watts, Ray L; Walker, Harrison C

    2011-01-01

    Unilateral and bilateral subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson's disease (PD) result in weight gain in the initial postoperative months, but little is known about the changes in weight following unilateral and staged bilateral STN DBS over longer time intervals. A case–control comparison evaluated weight changes over 2 years in 43 consecutive unilateral STN DBS patients, among whom 25 elected to undergo staged bilateral STN DBS, and 21 age-matched and disease severity matched PD controls without DBS. Regression analyses incorporating age, gender, and baseline weight in case or control were conducted to assess weight changes 2 years after the initial unilateral surgery. Unilateral STN DBS and staged bilateral STN DBS patients gained 3.9 ± 2.0 kg and 5.6 ± 2.1 kg versus their preoperative baseline weight (P < 0.001, respectively) while PD controls without DBS lost 0.8 ± 1.1 kg. Although bilateral STN DBS patients gained 1.7 kg more than unilateral STN DBS patients at 2 years, this difference was not statistically significant (P = 0.885). Although there was a trend toward greater weight gain in staged bilateral STN DBS patients versus unilateral patients, we found no evidence for an equivalent or synergistic increase in body weight following placement of the second DBS electrode. PMID:22398977

  8. Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length

    NASA Astrophysics Data System (ADS)

    Lolon, Elyezer P.

    Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may be shorter due to fracture growth out of zone, improper proppant settling, or proppant flowback, short calculated fracture lengths can also result from incorrect analysis techniques. It is known that fracturing fluid that remains in the fracture and formation after a hydraulic fracture treatment can decrease the productivity of a gas well by reducing the relative permeability to gas in the region invaded by this fluid. However, the relationships between fracture fluid cleanup, effective fracture length, and well productivity are not fully understood. In this work I used reservoir simulation to determine the relationship between fracture conductivity, fracture fluid production, effective fracture length, and well productivity. I simulated water saturation and pressure profiles around a propped fracture, tracked gas production along the length of the propped fracture, and quantified the effective fracture length (i.e., the fracture length under single-phase flow conditions that gives similar performance as for multiphase flow conditions), the "cleanup" fracture length (i.e., the fracture length corresponding to 90% cumulative gas flow rate into the fracture), and the "apparent" fracture length (i.e., the fracture length where the ratio of multiphase to single-phase gas entry rate profiles is unity). This study shows that the proppant pack is generally cleaned up and the cleanup lengths are close to designed lengths in relatively short times. Although gas is entering along entire fracture, fracturing fluid remains in the formation near the fracture. The water saturation distribution affects the gas entry rate profile, which determines the effective fracture length. Subtle changes in the gas rate entry profile can result in significant changes in effective fracture length. The results I derived from this work are consistent with prior work, namely that greater fracture conductivity results in more effective well cleanup and longer effective fracture lengths versus time. This study provides better explanation of mechanisms that affect fracturing fluid cleanup, effective fracture length, and well productivity than previous work.

  9. Maxillofacial and mandibular fractures.

    PubMed

    Rudy, R L; Boudrieau, R J

    1992-02-01

    Any traumatic event that produces maxillofacial and/or mandibular fractures generally results in gross and usually severe patient disfigurement and often results in the patient's inability to eat and drink. These fractures are exceptionally rewarding cases as simple techniques may be performed resulting in a successful functional outcome (ability to eat and drink) within a very short period of time (24 hours) after fracture stabilization. A markedly improved cosmetic appearance follows shortly thereafter once inflammation and edema resolve. The primary principle of fracture treatment, ie, providing stable fixation to the bone fragments, may be successfully used with wiring techniques only through an appreciation and proper application of biomechanical principles. Knowledge that bending forces (divided into their tensile and compressive components) are the primary forces to be neutralized dictates the use of the wiring techniques outlined as the "standard" to which all other methods of fixation for maxillofacial and mandibular fractures are compared. The location of the tension-band surface of the bone, the alveolar (oral) surface, dictates the most appropriate position for wire placement. Successful treatment is predicted on obtaining a cosmetically acceptable and functional result (Fig 29). Anatomic reduction and rigid fixation of fractures that can be reconstructed piece-by-piece creates optimal conditions for uncomplicated healing. Fractures in which bone loss or severe comminution exists, and which cannot be anatomically reconstructed, must be reduced using dental occlusion as the template for fracture fixation, thereby avoiding malocclusion. Excessive leverage on the bone fragments may occur secondary to malocclusion, resulting in an increased risk of complications (fragment motion, loosening of implants, infection). Some fractures with comminution or bone loss may not be suitable for wire fixation and must be treated by alternate methods (eg, external skeletal fixators, plates). PMID:1570433

  10. Containment of massive hydraulic fractures

    Microsoft Academic Search

    E. R. Simonson; A. S. Abou-Sayed; R. J. Clifton

    1976-01-01

    Hydraulic fracture containment is discussed from the point of view of linear elastic fracture mechanics. Three cases are analyzed: (a) Effect of different material properties for the pay zone and the barrier formation, (b) Characteristic of fracture propagation into region of varying in situ stress and (c) Effect of hydrostatic pressure gradients on fracture propagation into overlying or underlying barrier

  11. THE FRACTURE OF ICE Ih

    Microsoft Academic Search

    E. M. SCHULSON

    1987-01-01

    The brittle fracture of ice is considered from a physical viewpoint. Fracture under uniaxial tension is discussed in terms of crack nucleation and crack propagation. Fracture under uniaxial compression is described in tenns of fracture toughness, end constraint, Coulombic friction, and crack interactions within a shear fault. Models are presented and are compared with experimental results.

  12. Formation of Network Fractures During Hydraulic Fracturing of the Barnett Shale, a Tight Gas Shale with Preexisting Fractures

    Microsoft Academic Search

    S. Busetti; Z. Reches

    2007-01-01

    Hydraulic fracturing operations generate new fractures as well as dilate preexisting fractures, creating networks of fractures. Here we model the complexity of the created network fractures and apply the results to wellbore log data and hydrofracture operations in the Barnett Shale, a tight gas-shale that requires artificial fracture stimulation to produce. It is shown that the resulting fracture geometry is

  13. Detecting Unilateral Phrenic Paralysis by Acoustic Respiratory Analysis

    PubMed Central

    Fiz, José Antonio; Jané, Raimon; Lozano, Manuel; Gómez, Rosa; Ruiz, Juan

    2014-01-01

    The consequences of phrenic nerve paralysis vary from a considerable reduction in respiratory function to an apparently normal state. Acoustic analysis of lung sound intensity (LSI) could be an indirect non-invasive measurement of respiratory muscle function, comparing activity on the two sides of the thoracic cage. Lung sounds and airflow were recorded in ten males with unilateral phrenic paralysis and ten healthy subjects (5 men/5 women), during progressive increasing airflow maneuvers. Subjects were in sitting position and two acoustic sensors were placed on their back, on the left and right sides. LSI was determined from 1.2 to 2.4 L/s between 70 and 2000 Hz. LSI was significantly greater on the normal (19.3±4.0 dB) than the affected (5.7±3.5 dB) side in all patients (p?=?0.0002), differences ranging from 9.9 to 21.3 dB (13.5±3.5 dB). In the healthy subjects, the LSI was similar on both left (15.1±6.3 dB) and right (17.4±5.7 dB) sides (p?=?0.2730), differences ranging from 0.4 to 4.6 dB (2.3±1.6 dB). There was a positive linear relationship between the LSI and the airflow, with clear differences between the slope of patients (about 5 dB/L/s) and healthy subjects (about 10 dB/L/s). Furthermore, the LSI from the affected side of patients was close to the background noise level, at low airflows. As the airflow increases, the LSI from the affected side did also increase, but never reached the levels seen in healthy subjects. Moreover, the difference in LSI between healthy and paralyzed sides was higher in patients with lower FEV1 (%). The acoustic analysis of LSI is a relevant non-invasive technique to assess respiratory function. This method could reinforce the reliability of the diagnosis of unilateral phrenic paralysis, as well as the monitoring of these patients. PMID:24718599

  14. Fracturing of a deviated well

    SciTech Connect

    Yew, C.H.; Li, Y. (Univ. of Texas, TX (US))

    1988-11-01

    The fracturing of a deviated well and the deviation of a hydraulically induced fracture plane were analyzed by applying three-dimensional (3D) elasticity theory. It was demonstrated that, under the influence of the off-plane shear-stress components, the fracture lines on the well surface were inclined at an angle with respect to the direction of the well axis and that the plane initiated from these fracture lines deviates from the plane formed by these initial fracture lines.

  15. Acting alone: U.S. unilateral uses of force, military revolutions, and hegemonic stability theory 

    E-print Network

    Podliska, Bradley Florian

    2009-06-02

    The premise of this dissertation is straight-forward – the U.S., as hegemon, acts unilaterally given the power disparity between it and the rest of the world. In solving the puzzle of why presidents make the “wrong” ...

  16. Robotic Unilateral and Bilateral Upper-Limb Movement Training for Stroke Survivors Afflicted by

    E-print Network

    Rosen, Jacob

    for the upper limbs with a dual arm exoskeleton system (EXO-UL7) using three different modalities: bilateral exoskeleton was used to provide bilateral and unilateral treatments. Standard care was provided by a licensed

  17. Spatial Memory and Hippocampal Volume in Humans With Unilateral Vestibular Deafferentation

    E-print Network

    Hamilton, Derek

    2007 Wiley-Liss, Inc. KEY WORDS: hippocampus; navigation; unilateral vestibular deaf- ferentation to accurately navigate in space is thought to also depend on vestibular input (Etienne, 1980; Matthews et al

  18. The Management of Unilateral Poorly Functioning Kidneys in Patients With Posterior Urethral Valves

    Microsoft Academic Search

    Young H. Kim; Mark Horowitz; Andrew J. Combs; Victor W. Nitti; Kenneth I. Glassberg

    1997-01-01

    PurposeThere is no uniform agreement on how to manage the unilateral nonfunctioning or poorly functioning kidney associated with posterior urethral valves. We studied the results of treatment of our patients to make recommendations regarding management of these kidneys.

  19. Partial unilateral lesions of the mushroom bodies affect olfactory learning in honeybees Apis mellifera L.

    E-print Network

    Menzel, Randolf - Institut für Biologie

    Partial unilateral lesions of the mushroom bodies affect olfactory learning in honeybees Apis Toulouse cedex 04, France Keywords: brain lesion, cognition, honeybee, hydroxyurea, mushroom bodies been associated with olfactory learning and memory. Here we used hydroxyurea (HU) to treat honeybee

  20. Effect of unilateral lesion of amygdala on unmanifested response to Matatabi (Actinidia polygama) in cats.

    PubMed

    Katahira, K; Iwai, E

    1975-02-01

    The experiment was designed to elucidate the question whether the unilateral ablation of the amygdala significantly affects sexual behavior or not. For this purpose, the effect of the unilateral amygdalectomy upon Matatabi-response was investigated in the cat (R-cat), particularly in cats which showed unmanifested Matatabi-response in the innate status (NR-cat). Following the unilateral damage to the amygdala, NR-cats showed a significant manifestation in their Matatabi-response behavior, while R-cats indicated no change in it, their performance level being the same as preoperatively. It is concluded from the present results that even the unilateral ablation of the amygdala affects sexual behavior significantly, this being in contrast to many previous reprots. The present finding implies that individual differences in sexual behavior appear to depend on the neural basis of the amygdala, supporting an assumption that the amygdala is a controlling center of sexual and emotional behaviors. PMID:1129764

  1. Suspensions in hydraulic fracturing

    SciTech Connect

    Shah, S.N. [Univ. of Oklahoma, Norman, OK (United States)

    1996-12-31

    Suspensions or slurries are widely used in well stimulation and hydraulic fracturing processes to enhance the production of oil and gas from the underground hydrocarbon-bearing formation. The success of these processes depends significantly upon having a thorough understanding of the behavior of suspensions used. Therefore, the characterization of suspensions under realistic conditions, for their rheological and hydraulic properties, is very important. This chapter deals with the state-of-the-art hydraulic fracturing suspension technology. Specifically it deals with various types of suspensions used in well stimulation and fracturing processes, their rheological characterization and hydraulic properties, behavior of suspensions in horizontal wells, review of proppant settling velocity and proppant transport in the fracture, and presently available measurement techniques for suspensions and their merits. Future industry needs for better understanding of the complex behavior of suspensions are also addressed. 74 refs., 21 figs., 1 tab.

  2. Associations of Anisometropia with Unilateral Amblyopia, Interocular Acuity Difference and Stereoacuity in Preschoolers

    PubMed Central

    Ying, Gui-shuang; Huang, Jiayan; Maguire, Maureen; Quinn, Graham; Kulp, Marjean Taylor; Ciner, Elise; Cyert, Lynn; Orel-Bixler, Deborah

    2012-01-01

    Purpose To evaluate the relation of anisometropia with unilateral amblyopia, interocular acuity difference (IAD) and stereoacuity, among Head Start preschoolers, using both clinical notation and vector notation analyses. Design Multicenter, cross-sectional study. Participants 3- to 5-year-old participants in the Vision In Preschoolers (VIP) Study (N=4040). Methods Secondary analysis of VIP data from participants who had comprehensive eye examinations including monocular visual acuity (VA) testing, stereoacuity testing, and cycloplegic refraction. VA was retested with full cycloplegic correction when retest criteria were met. Unilateral amblyopia was defined as IAD ?2 lines in logarithm of the Minimum Angle of Resolution (logMAR). Anisometropia was defined as ?0.25 D (diopter) difference in spherical equivalent (SE) or in cylinder power, and also two approaches using power vector notation. The percentage with unilateral amblyopia, mean IAD, and mean stereoacuity were compared between anisometropic and isometropic children. Main Outcomes Measures The percentage with unilateral amblyopia, mean IAD, and mean stereoacuity. Results Compared with isometropic children, anisometropic children had a higher percentage of unilateral amblyopia (8% vs. 2%), larger mean IAD (0.07 vs. 0.05 logMAR) and worse mean stereoacuity (145 vs.117 arc sec) (all p<0.0001). Larger amounts of anisometropia were associated with higher percentages of unilateral amblyopia, larger IAD, and worse stereoacuity (trend p<0.001). Percentage of unilateral amblyopia was significantly increased with spherical equivalent (SE) anisometropia >0.5 D, cylindrical anisometropia >0.25 D, the vertical/horizontal meridian (J0) or oblique meridian (J45) >0.125 D, or vector dioptric distance (VDD) >0.35 D (all p<0.001). VDD had higher ability in detecting unilateral amblyopia than cylinder, SE, J0 and J45 (p<0.001). Conclusions The presence of and amount of anisometropia were associated with the presence of unilateral amblyopia, larger IAD and worse stereoacuity. The threshold level of anisometropia at which unilateral amblyopia becomes significant was lower than current guidelines. VDD is more accurate than spherical equivalent anisometropia or cylindrical anisometropia in identifying preschoolers with unilateral amblyopia. PMID:23174398

  3. Myoelectric activity during unilateral chewing in healthy subjects: Cycle duration and order of muscle activation

    Microsoft Academic Search

    Benito Rilo; José Luis da Silva; Francisco Gude; Urbano Santana

    1998-01-01

    Statement of problem. Craniomandibular disorders, unilateral mastication, and asymmetry of masticatory muscles appear to be related to each other. Thus, it is of interest to investigate masticatory muscle activity during unilateral mastication in healthy subjects.Purpose. This study monitored contractile activity of the right and left masticatory muscles during right- and left-side gum chewing.Material and methods. Electromyographic techniques were used to

  4. Survival after unilateral versus bilateral lung volume reduction surgery for emphysema

    Microsoft Academic Search

    D. L. Serna; M. Brenner; K. E. Osann; R MCKENNAJR; J. C. Chen; R. J. Fischel; B. U. Jones; A. F. Gelb; A. F. Wilson

    1999-01-01

    Objective: Bilateral staple lung volume reduction surgery (LVRS) immediately improves pulmonary function and dyspnea symptoms in patients with advanced heterogeneous emphysema to a greater degree than do unilateral procedures. However, the long-term outcome after these surgical procedures needs to be critically evaluated. We compare 2-year survival of patients who underwent unilateral versus bilateral video-assisted LVRS in a large cohort treated

  5. Genetic analysis of novel intra-species unilateral incompatibility in Brassica rapa (syn. campestris ) L

    Microsoft Academic Search

    Yoshinobu Takada; Takayuki Nakanowatari; Jun Sato; Katsunori Hatakeyama; Tomohiro Kakizaki; Akiko Ito; Go Suzuki; Hiroshi Shiba; Seiji Takayama; Akira Isogai; Masao Watanabe

    2005-01-01

    Plants have evolved many systems to prevent inappropriate fertilization. Among them, incompatibility is a well-organized system in which pollen germination or pollen-tube growth is inhibited in pistils. Self-incompatibility (SI), rejecting self-pollen, promotes outbreeding in flowering plants. On the other hand, inter-species incompatibility, preventing gene flow among species to restrict outbreeding, usually occurs unilaterally, and is known as unilateral incompatibility (UI).

  6. Do Audiologic Characteristics Predict Outcomes in Children with Unilateral Hearing Loss?

    PubMed Central

    Lieu, Judith E. C.; Karzon, Roanne K.; Ead, Banan; Tye-Murray, Nancy

    2014-01-01

    Objective To determine whether audiologic characteristics of unilateral hearing loss in children were associated with language, cognitive or achievement scores. Study design Case-control study Setting Pediatric otolaryngology ambulatory practice Patients Cases (n=109) were children aged 6–12 years with permanent unilateral hearing loss; controls (n=95) were siblings with normal bilateral hearing. Interventions Audiologic characteristics measured included side and severity of hearing loss, and word recognition scores in quiet and in noise. Main outcome measures Cognitive abilities were measured using the Wechsler Abbreviated Scale of Intelligence; reading, math and writing achievement was measured with the Wechsler Individual Achievement Test-Second Edition-Abbreviated; and oral language skills were measured with the Oral Written and Language Scales. Results Children with unilateral hearing loss had worse verbal cognitive and oral language scores than children with normal hearing, but no differences in achievement scores. Children with profound unilateral hearing loss tended to have worse cognitive scores and had significantly lower oral language scores. Higher word recognition scores in quiet of the normal hearing ear were associated with higher cognitive, oral language, and reading achievement scores. Higher word recognition scores in noise were slightly correlated with higher oral language scores. Conclusions As expected, children with unilateral hearing loss had worse language scores than their siblings with normal hearing with trends toward worse cognitive scores. Children with profound unilateral hearing loss tended to have worse outcomes than children with normal hearing or less severe unilateral loss. However, there were no differences in outcomes between children with right or left unilateral hearing loss. PMID:24232067

  7. Unilateral Eye Closure and Interhemispheric EEG Asymmetry during Sleep in the Pigeon (Columba livia)

    Microsoft Academic Search

    Niels C. Rattenborg; Charles J. Amlaner; Steven L. Lima

    2001-01-01

    Aquatic mammals (i.e., Cetaceans, eared seals and manatees) and birds show interhemispheric asymmetries (IA) in slow-wave sleep-related electroencephalographic (EEG) activity, suggesting that the depth of sleep differs between hemispheres. In birds, an association between unilateral eye closure and IA has been reported in five species from three orders (i.e., Galliformes, Charadriiformes, and Anseriformes). Moreover, unilateral eye closure has been observed

  8. Osteoporosis and Skeletal Fractures

    Microsoft Academic Search

    Michael J. Gardner; Demetris Demetrakopoulos; Michael K. Shindle; Matthew H. Griffith

    2006-01-01

    Osteoporosis affects millions of individuals worldwide, rendering them susceptible to fragility fractures of the spine, hip,\\u000a and wrist and leading to significant morbidity, mortality, and economic cost. Given the substantial impact of osteoporosis\\u000a on both patients and the medical community, it is imperative that physicians improve awareness and knowledge of osteoporosis\\u000a in the setting of low-energy fractures. In this review,

  9. [Surf and Seymour's fractures].

    PubMed

    Zipoli, B; Donon, L; Ribeyre, D

    2010-09-01

    The authors present four cases of Seymour-like juxtaepiphyseal fractures related to surf accidents. All four patients were novices at the sport, had the same fractures in identical circumstances. In all cases, reduction was achieved using an 'in-and-out' 1.2 K-wire serving as a 'joystick' which was then also used for fixation. The nail was fixed at the end. PMID:20724203

  10. Changes in contralateral protein metabolism following unilateral sciatic nerve section

    SciTech Connect

    Menendez, J.A.; Cubas, S.C.

    1990-03-01

    Changes in nerve biochemistry, anatomy, and function following injuries to the contralateral nerve have been repeatedly reported, though their significance is unknown. The most likely mechanisms for their development are either substances carried by axoplasmic flow or electrically transmitted signals. This study analyzes which mechanism underlies the development of a contralateral change in protein metabolism. The incorporation of labelled amino acids (AA) into proteins of both sciatic nerves was assessed by liquid scintillation after an unilateral section. AA were offered locally for 30 min to the distal stump of the sectioned nerves and at homologous levels of the intact contralateral nerves. At various times, from 1 to 24 h, both sciatic nerves were removed and the proteins extracted with trichloroacetic acid (TCA). An increase in incorporation was found in both nerves 14-24 h after section. No difference existed between sectioned and intact nerves, which is consistent with the contralateral effect. Lidocaine, but not colchicine, when applied previously to the nerves midway between the sectioning site and the spinal cord, inhibited the contralateral increase in AA incorporation. It is concluded that electrical signals, crossing through the spinal cord, are responsible for the development of the contralateral effect. Both the nature of the proteins and the significance of the contralateral effect are matters for speculation.

  11. Captopril induced renographic alteration in unilateral renal artery stenosis

    SciTech Connect

    Oei, H.Y.; Geyskes, G.G.; Dorhout Mees, E.J.; Puijlaert, C.B.A.J.

    1984-01-01

    In patients with unilateral renal artery stenosis (URAS) captopril administration will deteriorate glomerular filtration in the affected kidney by interruption of autoregulatory mechanisms. This effect might be detectable on renography and could be useful for the diagnosis of renovascular hypertension. After discontinuation of all medication, Tc-99m diethylene triamine pentaacetic acid (DTPA) gammacamera renography, followed by I-131 orthoiodohippurate (OIH) renography were performed in 15 hypertensive patients who were poorly controlled with medical therapy. This double examination was repeated some days later after administration of 25 mg captopril one hour prior to the examination. After this, angiography was done and patients with stenosis of the renal artery were treated by percutaneous transluminal dilatation (PTD). Five patients were excluded due to bilateral or segmental stenosis of the renal artery. Four URAS-patients, in whom the blood pressure improved after PTD, showed after administration of captopril a striking renographic alteration in the affected kidney. The DTPA-renogram which initially had an upslope phase, showed a blood disappearance curve and the OIH-renogram, which still had an upslope phase, showed a slower excretion. These renographic alteration did not occur in the other 2 URAS-patients, who had no benefit of the PTD and in the 4 remaining patients without stenosis. These findings suggest that captopril induced renographic alterations may be important for the diagnosis of hemodynamic significant URAS. For this purpose either DTPA or OIH can be used.

  12. Impaired Emotional Declarative Memory Following Unilateral Amygdala Damage

    PubMed Central

    Adolphs, Ralph; Tranel, Daniel; Denburg, Natalie

    2000-01-01

    Case studies of patients with bilateral amygdala damage and functional imaging studies of normal individuals have demonstrated that the amygdala plays a critical role in encoding emotionally arousing stimuli into long-term declarative memory. However, several issues remain poorly understood: the separate roles of left and right amygdala, the time course over which the amygdala participates in memory consolidation, and the type of knowledge structures it helps consolidate. We investigated these questions in eight subjects with unilateral amygdala damage, using several different measures. For comparison, our main task used stimuli identical to those used previously to investigate emotional declarative memory in patients with bilateral amygdala damage. Contrasts with both brain-damaged and normal control groups showed that subjects with left amygdala damage were impaired in their memory for emotional stimuli, despite entirely normal memory for neutral stimuli (because of a number of caveats, the findings from subjects with right amygdala damage were less clear). Follow-up experiments suggested that the normal facilitation of memory for emotional stimuli may develop over an extended time course (>30 min), consistent with prior findings, and that the specific impairment we report may depend in part on the lexical nature of the task used (written questionnaire). We stress the complex and temporally extended nature of memory consolidation and suggest that the amygdala may influence specific components of this process. PMID:10837507

  13. Primate translational vestibuloocular reflexes. IV. Changes after unilateral labyrinthectomy

    NASA Technical Reports Server (NTRS)

    Angelaki, D. E.; Newlands, S. D.; Dickman, J. D.

    2000-01-01

    The effects of unilateral labyrinthectomy on the properties of the translational vestibuloocular reflexes (trVORs) were investigated in rhesus monkeys trained to fixate near targets. Translational motion stimuli consisted of either steady-state lateral and fore-aft sinusoidal oscillations or short-lasting transient displacements. During small-amplitude, steady-state sinusoidal lateral oscillations, a small decrease in the horizontal trVOR sensitivity and its dependence on viewing distance was observed during the first week after labyrinthectomy. These deficits gradually recovered over time. In addition, the vertical response component increased, causing a tilt of the eye velocity vector toward the lesioned side. During large, transient lateral displacements, the deficits were larger and longer lasting. Responses after labyrinthectomy were asymmetric, with eye velocity during movements toward the side of the lesion being more compromised. The most profound effect of the lesions was observed during fore-aft motion. Whereas responses were kinematically appropriate for fixation away from the side of the lesion (e.g., to the left after right labyrinthectomy), horizontal responses were anticompensatory during fixation at targets located ipsilateral to the side of the lesion (e.g., for targets to the right after right labyrinthectomy). This deficit showed little recovery during the 3-mo post-labyrinthectomy testing period. These results suggest that inputs from both labyrinths are important for the proper function of the trVORs, although the details of how bilateral signals are processed and integrated remain unknown.

  14. Bilateral Effects of Unilateral Cochlear Implantation in Congenitally Deaf Cats

    PubMed Central

    O'Neil, Jahn N.; Limb, Charles J.; Baker, Christa A.; Ryugo, David K.

    2014-01-01

    Congenital deafness results in synaptic abnormalities in auditory nerve endings. These abnormalities are most prominent in terminals called endbulbs of Held, which are large, axosomatic synaptic endings whose size and evolutionary conservation emphasize their importance. Transmission jitter, delay, or failures, which would corrupt the processing of timing information, are possible consequences of the perturbations at this synaptic junction. We sought to determine whether electrical stimulation of the congenitally deaf auditory system via cochlear implants would restore the endbulb synapses to their normal morphology. Three and 6-month-old congenitally deaf cats received unilateral cochlear implants and were stimulated for a period of 10–19 weeks by using human speech processors. Implanted cats exhibited acoustic startle responses and were trained to approach their food dish in response to a specific acoustic stimulus. Endbulb synapses were examined by using serial section electron microscopy from cohorts of cats with normal hearing, congenital deafness, or congenital deafness with a cochlear implant. Synapse restoration was evident in endbulb synapses on the stimulated side of cats implanted at 3 months of age but not at 6 months. In the young implanted cats, post-synaptic densities exhibited normal size, shape, and distribution, and synaptic vesicles had density values typical of hearing cats. Synapses of the contralateral auditory nerve in early implanted cats also exhibited synapses with more normal structural features. These results demonstrate that electrical stimulation with a cochlear implant can help preserve central auditory synapses through direct and indirect pathways in an age-dependent fashion. PMID:20437534

  15. Recovery of function following unilateral damage to visuoparietal cortex.

    PubMed

    Rushmore, R J; Payne, Bertram; Valero-Cabre, Antoni

    2010-06-01

    Damage to the visuoparietal cortex located in the banks of the middle suprasylvian gyrus of the cat has been shown to produce a deficit in the detection and localization of moving visual cues presented in the contralesional visual hemifield. There is evidence from reversible cooling deactivation studies that the integrity of this orienting function is not completely dependent on the VP cortex and that under the right circumstances, other brain regions may come online and completely take over the processing that subserves this behavior. We examined the recovery of orienting behavior after unilateral damage to the VP cortex. We found that consistent with previous data, VP damage produced an impairment in the capacity to detect and orient to moving visual stimuli in the contralesional visual field. Over a span of days, spontaneous recovery fully occurred. The ability to detect and localize static visual stimuli was tested as a fiducial measure of parietal cortex function, and this function did not recover. We conclude that the detection and localization of moving visual stimuli is not a function that requires VP cortex and argue for the existence of a parallel and redundant subcortical-cortical brain network that serves as the substrate for recovery of function. PMID:20461362

  16. Bimanual force coordination in children with spastic unilateral cerebral palsy.

    PubMed

    Smits-Engelsman, B C M; Klingels, K; Feys, H

    2011-01-01

    In this study bimanual grip-force coordination was quantified using a novel "Gripper" system that records grip forces produced while holding a lower and upper unit, in combination with the lift force necessary to separate these units. Children with unilateral cerebral palsy (CP) (aged 5-14 years, n=12) were compared to age matched typically developing (TD) children (n=23). Compared to TD, the CP-group is much slower and takes 50% more time to generate grip and lift forces with more fixating force before lifting the upper unit. In addition the coordination between forces in both hands is reduced. The CP-group increases the lift force in the upper hand 2.5 times more than the holding force when pulling the two units apart, while this is only 1.5 times in TD. Moreover, the correlation between forces generated in both hands in the CP-group is lower. The lack of fine tuning of the forces, measured by the linearity error is increased, especially when the magnet load keeping the unit together is low. The results indicate an impaired pull-hold synergy between upper and lower hand and the lift force. Bimanual tasks evaluating bimanual grip and lift forces in children with CP and can give us new insights in the underlying force control mechanisms of the spastic hand. PMID:21592724

  17. Fracture Modeling and Flow Behavior in Shale Gas Reservoirs Using Discrete Fracture Networks

    E-print Network

    Ogbechie, Joachim Nwabunwanne

    2012-02-14

    deviation Frac Fracture Cv Coefficient of variation CI Connectivity index HF Hydraulic fracture cum Cumulative FA Fracture aperture FD Fracture density FL Fracture length HFA Hydraulic fracture aperture HFL Hydraulic fracture length NFS Number... .................................................................................................... 58 5.6 Change in cum. gas produced due to increase in fracture aperture for case 1 .................................................................................................... 58 5.7 Change in pressure response due to decrease...

  18. Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock

    SciTech Connect

    Wu, Yu-Shu; Ye, Ming; Sudicky, E.A.

    2007-12-15

    We propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity, i.e., matrix diffusion enhancement induced by rapid fluid flow within fractures. According to the boundary-layer or film theory, fracture flow enhanced matrix diffusion may dominate mass-transfer processes at fracture-matrix interfaces, because rapid flow along fractures results in large velocity and concentration gradients at and near fracture-matrix interfaces, enhancing matrix diffusion at matrix surfaces. In this paper, we present a new formulation of the conceptual model for enhanced fracture-matrix diffusion, and its implementation is discussed using existing analytical solutions and numerical models. In addition, we use the enhanced matrix diffusion concept to analyze laboratory experimental results from nonreactive and reactive tracer breakthrough tests, in an effort to validate the new conceptual model.

  19. The Unilateral, Self-Deregulation of AT&T

    NASA Astrophysics Data System (ADS)

    Maloff, Joel H.

    1990-01-01

    The provision of telecommunications products and services in the United States has been dominated by AT&T and the Bell System for more than one hundred years. From the early days of telephones, it was clear that some framework of logic was required to provide "universal" telephone services to the vast majority of American citizens. The concept was known as "natural monopoly", and for the most part, has served us well. We are all aware of statements concerning absolute power corrupting absolutely, and AT&T has not been immune to this law of human nature. Several times during the past century, action has been required by the Federal Government to regulate and constrain AT&T and the Bell System from anti-competitive and predatory actions. These have been called consent decrees, Computer Inquiry II, Computer Inquiry III, and the Modified Final Judgment. The regulations and constraints imposed upon AT&T, with good reason, are now becoming eroded. The perception of a more highly competitive marketplace capable of accommodating an unrestrained AT&T, the impact of uncoordinated national and regional government policies, and unilateral actions by AT&T themselves are bringing us to the edge of an abyss. There are substantial reasons to believe that AT&T will use its considerable might to eliminate its competitors, once free to do so. Must we be doomed to repeat history with still another antitrust case against AT&T some years from now? Logic demands that we learn from the past, and that telecommunications policies be based upon that knowledge.

  20. Fracture Conductivity of the Eagle Ford Shale 

    E-print Network

    Guzek, James J

    2014-07-25

    conductivity is influenced by several variables including fracture surface roughness, fracture closure stress, proppant size, and proppant concentration. The proppant concentration within a fracture can significantly affect the magnitude of fracture...

  1. Fracture toughness tests of structural weldments 

    E-print Network

    Weir, Breanna M

    2013-02-22

    on the determination of fracture toughness. Fracture toughness measures material resistance to the presence of a crack or other flaw. Low fracture toughness indicates brittle behavior if a flaw is present. One way to quantify fracture toughness uses crack...

  2. Fracture Conductivity of the Eagle Ford Shale

    E-print Network

    Guzek, James J

    2014-07-25

    conductivity is influenced by several variables including fracture surface roughness, fracture closure stress, proppant size, and proppant concentration. The proppant concentration within a fracture can significantly affect the magnitude of fracture...

  3. Unilateral Subthalamic Nucleus Stimulation Has a Measurable Ipsilateral Effect on Rigidity And Bradykinesia in Parkinson Disease

    PubMed Central

    Tabbal, Samer D.; Ushe, Mwiza; Mink, Jonathan W.; Revilla, Fredy J.; Wernle, Angie R.; Hong, Minna; Karimi, Morvarid; Perlmutter, Joel S.

    2008-01-01

    Background Bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor function in Parkinson disease (PD). However, little is known about the quantitative effects on motor behavior of unilateral STN DBS. Methods In 52 PD subjects with STN DBS, we quantified in a double-blinded manner rigidity (n= 42), bradykinesia (n= 38), and gait speed (n= 45). Subjects were tested in four DBS conditions: both on, left on, right on and both off. A force transducer was used to measure rigidity across the elbow, and gyroscopes were used to measure angular velocity of hand rotations for bradykinesia. About half of the subjects were rated using the Unified Parkinson Disease Rating Scale (part III) motor scores for arm rigidity and repetitive hand rotation simultaneously during the kinematic measurements. Subjects were timed walking 25 feet. Results All subjects had significant improvement with bilateral STN DBS. Contralateral, ipsilateral and bilateral stimulation significantly reduced rigidity and bradykinesia. Bilateral stimulation improved rigidity more than unilateral stimulation of either side, but there was no significant difference between ipsilateral and contralateral stimulation. Although bilateral stimulation also increased hand rotation velocity more than unilateral stimulation of either side, contralateral stimulation increased hand rotation significantly more than ipsilateral stimulation. All stimulation conditions improved walking time but bilateral stimulation provided the greatest improvement. Conclusions Unilateral STN DBS decreased rigidity and bradykinesia contralaterally as well ipsilaterally. As expected, bilateral DBS improved gait more than unilateral DBS. These findings suggest that unilateral STN DBS alters pathways that affect rigidity and bradykinesia bilaterally but do not support the clinical use of unilateral STN DBS since bilateral DBS clearly provides greater benefit. PMID:18329019

  4. Fracking, fracture, and permeability

    NASA Astrophysics Data System (ADS)

    Turcotte, D. L.; Norris, J.; Rundle, J. B.

    2013-12-01

    Injections of large volumes of water into tight shale reservoirs allows the extraction of oil and gas not previously accessible. This large volume 'super' fracking induces damage that allows the oil and/or gas to flow to an extraction well. The purpose of this paper is to provide a model for understanding super fracking. We assume that water is injected from a small spherical cavity into a homogeneous elastic medium. The high pressure of the injected water generates hoop stresses that reactivate natural fractures in the tight shales. These fractures migrate outward as water is added creating a spherical shell of damaged rock. The porosity associated with these fractures is equal to the water volume injected. We obtain an analytic expression for this volume. We apply our model to a typical tight shale reservoir and show that the predicted water volumes are in good agreement with the volumes used in super fracking.

  5. Geometrically Frustrated Fracture Mechanics

    NASA Astrophysics Data System (ADS)

    Mitchell, Noah; Koning, Vinzenz; Vitelli, Vincenzo; Irvine, William T. M.

    2015-03-01

    When a flat elastic sheet is forced to conform to a surface with Gaussian curvature, stresses arise in the sheet. The mismatch between initial and final metrics gives rise to new fracture behavior which cannot be achieved by boundary loading alone. Using experiments of PDMS sheets frustrated on 3D-printed surfaces and a linearized analytical model, we demonstrate the ability of curvature to govern the sheets' fracture phenomenology. In this talk, we first show that curvature can both stimulate and suppress fracture initiation, depending on the position and orientation of the initial slit. Secondly, we show that curvature can steer the path of a crack as it propagates through the material. Lastly, the curvature can arrest cracks which would otherwise continue to propagate.

  6. Fracture risk assessment.

    PubMed

    McCloskey, Eugene; Johansson, Helena; Oden, Anders; Kanis, John A

    2012-08-01

    Having traditionally relied on measurements of bone mineral density, it is now established that the consideration of other risk variables improves the categorisation of fracture risk. Whereas several models are available, the FRAX models are the most extensively used. The approach uses easily obtained clinical risk factors to estimate 10 year fracture probability, with or without femoral neck bone mineral density (BMD), to enhance fracture risk prediction. It has been constructed and validated using primary data from population based cohorts around the world, including centres from North America, Europe, Asia and Australia. The FRAX® tool should not be considered as a gold standard, but rather as a platform technology on which to build as new validated risk indicators become available. Notwithstanding, the present models provide an aid to enhance patient assessment by the integration of clinical risk factors alone and/or in combination with BMD. PMID:22579965

  7. Talar neck fractures.

    PubMed

    Berlet, G C; Lee, T H; Massa, E G

    2001-01-01

    Clinical management of talar neck fractures is complex and fraught with complications. As Gaius Julius Caesar stated: "The die is cast"; often the outcome of a talar neck fracture is determined at the time of injury. The authors believe, however, that better results can be achieved by following some simple guidelines. The authors advocate prompt and precise anatomic surgical reduction, preferring the medial approach with secondary anterolateral approach. Preservation of blood supply can be achieved by a thorough understanding of vascular pathways and efforts to stay within appropriate surgical intervals. The authors advocate bone grafting of medial neck comminution (if present) to prevent varus malalignment and rigid internal fixation to allow for joint mobilization postoperatively. These guidelines may seem simple, but when dealing with the complexity of talar neck fractures, the foot and ankle surgeon needs to focus and rely on easily grasped concepts to reduce poor outcomes. PMID:11465133

  8. Bone fracture repair - series (image)

    MedlinePLUS

    ... three main treatment options for bone fractures are: Casting Open reduction, and internal fixation- this involves a ... fractures not able to be realigned (reduced) by casting, or in cases in which the long-term ...

  9. Fracture characterization of multilayered reservoirs

    SciTech Connect

    Britt, L.K.; Larsen, M.J.

    1986-01-01

    Fracture treatment optimization techniques have been developed using Long-Spaced-Digital-Sonic (LSDS) log, pumpin-flowback, mini-frac, and downhole treating pressure data. These analysis techniques have been successfully applied in massive hydraulic fracturing (MHF) of ''tight gas'' wells. Massive hydraulic fracture stimulations have been used to make many tight gas reservoirs commercially attractive. However, studies have shown that short highly conductive fractures are optimum for the successful stimulation of wells in moderate permeability reservoirs. As a result, the ability to design and place optimal fractures in these reservoirs is critical. This paper illustrates the application of fracture analysis techniques to a moderate permeability multi-layered reservoir. These techniques were used to identify large zonal variations in rock properties and pore pressure which result from the complex geology. The inclusion of geologic factors in fracture treatment design allowed the placement of short highly conductive fractures which were used to improve injectivity and vertical sweep, and therefore, ultimate recovery.

  10. Fracture prediction in metal sheets

    E-print Network

    Lee, Young-Woong

    2005-01-01

    One of the most important failure modes of thin-walled structures is fracture. Fracture is predominantly tensile in nature and, in most part, is operated by the physical mechanisms of void nucleation, growth, and linkage. ...

  11. Fluid pressure variations during hydraulic fracturing

    Microsoft Academic Search

    N. Conrad; A. A. Daneshy

    1985-01-01

    Fluid pressure inside hydraulic fractures causes their propagation. The potential energy of this fluid provides the energy needed for the creation of fracture surfaces. Theoretical analysis of hydraulic fracturing has shown that fluid pressure needed for fracture extension decreases as the fracture becomes longer. Experimental work on 2-dimensional fractures shows the same trend in laboratory specimens. It also shows that

  12. What Is Hydraulic Fracturing?

    NSDL National Science Digital Library

    2012-01-01

    Hydraulic fracturing is a process used in nine out of 10 natural gas wells in the United States, where millions of gallons of water, sand and chemicals are pumped underground to break apart the rock and release the gas. Scientists are worried that the chemicals used in fracturing may pose a threat either underground or when waste fluids are handled and sometimes spilled on the surface. This poster presentation illustrates the under surface process of hydraulic fracking and the distribution flow to the market.

  13. Fractured Petroleum Reservoirs

    SciTech Connect

    Firoozabadi, Dr. Abbas

    2000-01-18

    In this report the results of experiments of water injection in fractured porous media comprising a number of water-wet matrix blocks are reported for the first time. The blocks experience an advancing fracture-water level (FWL). Immersion-type experiments are performed for comparison; the dominant recovery mechanism changed from co-current to counter-current imbibition when the boundary conditions changed from advancing FWL to immersion-type. Single block experiments of co-current and counter-current imbibition was performed and co-current imbibition leads to more efficient recovery was found.

  14. Pressurization of a fractured wellbore

    Microsoft Academic Search

    C. Atkinson; M. Thiercelin

    1997-01-01

    This paper presents the development of two-dimensional models to analyze the behaviour of a pre-existing fracture intersecting\\u000a a pressurized wellbore. The fracture has an arbitrary location and inclination with respect to the wellbore and the far-field\\u000a state of stress and it is assumed that the wellbore fluid penetrates the fracture only in the section where the fracture is\\u000a open. The

  15. Optimization of fracture treatment designs

    E-print Network

    Rueda, Jose Ignacio

    1992-01-01

    integer-linear programming to adjust a treatment fluid selection, pump rate, proppant volume and fracture dimensions to arrive at an optimal design. Through mixed integer-linear programming, Thompson showed that it is possible to design a less expensive... design, the engineer must determine the fracturing fluid properties, injection rate, fracture dimensions and the fracture conductivity that maximize the profit of the well. Conventional optimization techniques have been used by industry for many years...

  16. Ketorolac Administration Does Not Delay Early Fracture Healing in a Juvenile Rat Model

    PubMed Central

    Cappello, Teresa; Nuelle, Julia A.V.; Katsantonis, Nicolas; Nauer, Rachel K.; Lauing, Kristen L.; Jagodzinski, Jason E.; Callaci, John J.

    2014-01-01

    Background Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective at controlling pain in children, especially in the treatment of fractures. Adult animal and adult clinical studies demonstrate conflicting evidence for the inhibitory relationship between NSAIDs and fracture healing. Published pediatric orthopaedic clinical studies do not demonstrate an inhibitory effect of ketorolac on bone healing. Little is known about the effects of any NSAID on bone formation in juvenile animals. This study investigates the effects of the NSAID ketorolac on fracture healing in a juvenile rat model. Methods Unilateral surgically induced and stabilized tibial shaft fractures were created in 45 juvenile (3 to 4wk old) male Sprague-Dawley rats. Either ketorolac (5 mg/kg; n=24) or saline (0.9% normal saline; n=21) was then administered to the rats 6 d/wk by intraperitoneal injections. Animals were then randomly assigned into time groups and euthanized at 7 days (n=8 ketorolac, n=7 saline), 14 days (n=8 ketorolac, n=7 saline), or 21 days (n=8 ketorolac, n=7 saline) postfracture. Biomechanical analysis was performed using a custom-designed 4-point bending loading apparatus. Statistics for tibial stiffness and strength data were performed using software package Systat 11. Specimens were also evaluated histologically using hematoxylin and eosin staining. Results Strength and stiffness of all fractured tibiae increased over time from day 7 to day 21 regardless of treatment type. No statistical difference was found between the fractured tibiae strength or stiffness in the ketorolac or control-treated specimens at the same time point. In addition, the quality of the fracture callus was similar in both groups at each of the time points. Conclusions In this study of a juvenile rat model with a stabilized tibia fracture, fracture callus strength, stiffness, and histologic characteristics were not affected by the administration of ketorolac during the first 21 days of fracture healing. Clinical Relevance The absence of inhibitory effects of ketorolac on early juvenile rat fracture healing supports the clinical practice of utilizing NSAIDs for analgesia in children with long bone fractures. PMID:23653032

  17. Unilateral vs. bilateral STN DBS effects on working memory and motor function in Parkinson disease

    PubMed Central

    Hershey, T.; Wu, J.; Weaver, P.M.; Perantie, D.C.; Karimi, M.; Tabbal, S.D.; Perlmutter, J.S.

    2008-01-01

    Bilateral subthalamic nucleus deep brain stimulation (STN DBS) can reduce working memory while improving motor function in Parkinson disease (PD), but findings are variable. One possible explanation for this variability is that the effects of bilateral STN DBS on working memory function depend in part on functional or disease asymmetry. The goal of this study was to determine the relative contributions of unilateral DBS to the effects seen with bilateral DBS. Motor (Unified Parkinson Disease Rating Scale Part III, UPDRS) and working memory function (Spatial Delayed Response, SDR) were measured in 49 PD patients with bilateral STN DBS while stimulators were Both-off, Left-on, Right-on and Both-on in a randomized, double-blind manner. Patients were off PD medications overnight. Effects of unilateral DBS were compared to effects of bilateral STN DBS. Mean UPDRS and SDR responses to Left-on vs. Right-on conditions did not differ (p>.20). However, improvement in contralateral UPDRS was greater and SDR performance was more impaired by unilateral DBS in the more affected side of the brain than in the less affected side of the brain (p=.008). The effect of unilateral DBS on the more affected side on contralateral UPDRS and SDR responses was equivalent to that of bilateral DBS. These results suggest that motor and working memory function respond to unilateral STN DBS differentially depending on the asymmetry of motor symptoms. PMID:18162183

  18. Midterm outcome after unilateral approach for bilateral decompression of lumbar spinal stenosis: 5-year prospective study

    PubMed Central

    Kaya, Ramazan Alper; Türkmenoglu, Osman Nuri; Tuncer, Cengiz; Çolak, ?brahim; Ayd?n, Yunus

    2007-01-01

    The aim of our study is to evaluate the results and effectiveness of bilateral decompression via a unilateral approach in the treatment of degenerative lumbar spinal stenosis. We have conducted a prospective study to compare the midterm outcome of unilateral laminotomy with unilateral laminectomy. One hundred patients with 269 levels of lumbar stenosis without instability were randomized to two treatment groups: unilateral laminectomy (Group 1), and laminotomy (Group 2). Clinical outcomes were assessed with the Oswestry Disability Index (ODI) and Short Form–36 Health Survey (SF-36). Spinal canal size was measured pre- and postoperatively. The spinal canal was increased to 4–6.1-fold (mean 5.1 ± SD 0.8-fold) the preoperative size in Group 1, and 3.3–5.9-fold (mean 4.7 ± SD 1.1-fold) the preoperative size in Group 2. The mean follow-up time was 5.4 years (range 4–7 years). The ODI scores decreased significantly in both early and late follow-up evaluations and the SF-36 scores demonstrated significant improvement in late follow-up results in our series. Analysis of clinical outcome showed no statistical differences between two groups. For degenerative lumbar spinal stenosis unilateral approaches allowed sufficient and safe decompression of the neural structures and adequate preservation of vertebral stability, resulted in a highly significant reduction of symptoms and disability, and improved health-related quality of life. PMID:17712577

  19. Viscoelastic rocket grain fracture analysis

    Microsoft Academic Search

    E. C. Francis; C. H. Carlton; R. E. Thompson

    1974-01-01

    A viscoelastic fracture analysis has been developed for rocket grain fracture predictions. The fracture analysis uses a stress intensity factor technique to predict crack velocity histories under thermal and pressurization loading conditions. The theory is compared with two-dimensional pressurized tests of two typical rocket motor geometries using the viscoelastic material, Solithane 113.

  20. Containment of Massive Hydraulic Fractures

    Microsoft Academic Search

    E. R. Simonson; A. S. Abou-Sayed; R. J. Clifton

    1978-01-01

    Based on two-dimensional analyses of three cases involving the relationship of linear fracture mechanics to the containment of massive hydraulic fractures (MHF), Terra Tek Inc. concluded that the mechanical properties of the pay zone and the barrier formation, as well as the minimum horizontal in situ stresses for these layers, play important roles in the prediction of hydraulic-fracture containment. The

  1. Relative Permeability of Fractured Rock

    E-print Network

    Stanford University

    SGP-TR-172 Relative Permeability of Fractured Rock Mark D. Habana June 2002 Financial support experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach permeability of a core is especially important in a fractured rock. The rock may change as asperities

  2. Concomitant abducens and facial nerve palsies following blunt head trauma associated with bone fracture.

    PubMed

    Ji, Min-Jeong; Han, Sang-Beom; Lee, Seung-Jun; Kim, Moosang

    2015-01-01

    A 22-year-old man was referred for horizontal diplopia that worsened on left gaze. He had been admitted for a head trauma caused by a traffic accident. Brain CT scan showed a longitudinal fracture of the left temporal bone with extension to the left carotid canal and central skull base, including sphenoid lateral wall and roof, and left orbit medial wall non-displaced fracture. Prism cover test revealed 20 prism diopters of esotropia and abduction limitation in the left eye. Hess screening test results were compatible with left abducens nerve paralysis. Symptoms suggesting complete lower motor neuron palsy of the left facial nerve, such as unilateral facial drooping, inability to raise the eyebrow and difficulty closing the eye, were present. As there was no improvement in facial paralysis, the patient received surgical intervention using a transmastoidal approach. Three months postoperatively, prism cover test showed orthotropia, however, the facial nerve palsy persisted. PMID:26178005

  3. Hydraulic fracture geometry: fracture containment in layered formations

    SciTech Connect

    van Eekelen, H.A.M.

    1982-06-01

    One of the main problems in hydraulic fracturing technology is the prediction of fracture height. In particular, the question of what constitutes a barrier to vertical fracture propagation is crucial to the success of field operations. An analysis of hydraulic fracture containment effects has been performed. The main conclusion is that in most cases the fracture will penetrate into the layers adjoining the pay zone, the depth of penetration being determined by the differences in stiffness and in horizontal in-situ stress between the pay zone and the adjoining layers. For the case of a stiffness contrast, an estimate of the penetration depth is given. 35 refs.

  4. Entablature: fracture types and mechanisms

    NASA Astrophysics Data System (ADS)

    Forbes, A. E. S.; Blake, S.; Tuffen, H.

    2014-05-01

    Entablature is the term used to describe zones or tiers of irregular jointing in basaltic lava flows. It is thought to form when water from rivers dammed by the lava inundates the lava flow surface, and during lava-meltwater interaction in subglacial settings. A number of different fracture types are described in entablature outcrops from the Búrfell lava and older lava flows in Þjórsárdalur, southwest Iceland. These are: striae-bearing, column-bounding fractures and pseudopillow fracture systems that themselves consist of two different fracture types—master fractures with dimpled surface textures and subsidiary fractures with curved striae. The interaction of pseudopillow fracture systems and columnar jointing in the entablature produces the chevron fracture patterns that are commonly observed in entablature. Cube-jointing is a more densely fractured version of entablature, which likely forms when more coolant enters the hot lava. The entablature tiers display closely spaced striae and dendritic crystal shapes which indicate rapid cooling. Master fracture surfaces show a thin band with an evolved composition at the fracture surface; mineral textures in this band also show evidence of quenching of this material. This is interpreted as gas-driven filter pressing of late-stage residual melt that is drawn into an area of low pressure immediately preceding or during master fracture formation by ductile extensional fracture of hot, partially crystallised lava. This melt is then quenched by an influx of water and/or steam when the master fracture fully opens. Our findings suggest that master fractures are the main conduit for coolant entering the lava flow during entablature formation.

  5. Tibial plateau stress fracture

    Microsoft Academic Search

    Scott A Brumby; Richard Carrington; Shay Zayontz; Tim Reish; Richard D Scott

    2003-01-01

    Unicompartmental knee arthroplasty has gained popularity recently as a treatment for unicompartmental tibiofemoral non inflammatory arthritis. Tibial plateau stress fracture after unicompartmental knee arthroplasty (UKA) through guide pin holes placed in the proximal tibia has not been previously reported. In each case in this report, the compressive strength of the proximal tibia was reduced by the drilling of multiple holes

  6. Increasing Metal Fracture Toughness

    NASA Technical Reports Server (NTRS)

    Lawing, P. L.; Wood, W. H.; Sandefur, P. G. J.

    1982-01-01

    In technique developed at Langley Research Center several thin sheets of metal are diffusion-brazed together in vacuum furnace to create thick piece of metal that retains much of fracture toughness of its thin components. Technique is expected to make many of high-strength stainless steels, not currently suitable, usable at cryogenic temperatures.

  7. Injection through fractures

    SciTech Connect

    Johns, R.A.

    1987-05-01

    Tracer tests are conducted in geothermal reservoirs as an aid in forecasting thermal breakthrough of reinjection water. To interpret tracer tests, mathematical models have been developed based on the various transport mechanisms in these highly fractured reservoirs. These tracer flow models have been applied to interpret field tests. The resulting matches between the model and field data were excellent and the model parameters were used to estimate reservoir properties. However, model fitting is an indirect process and the model's ability to estimate reservoir properties cannot be judged solely on the quality of the match between field data and model predictions. The model's accuracy in determining reservoir characteristics must be independently verified in a closely controlled environment. In this study, the closely controlled laboratory environment was chosen to test the validity and accuracy of tracer flow models developed specifically for flow in fractured rocks. The laboratory tracer tests were performed by flowing potassium iodide (KI) through artificially fractured core samples. The tracer test results were then analyzed with several models to determine which best fit the measured data. A Matrix Diffusion model was found to provide the best match of the tracer experiments. The core properties, as estimated by the Matrix Diffusion model parameters generated from the indirect matching process, were then determined. These calculated core parameters were compared to the measured core properties and were found to be in agreement. This verifies the use of the Matrix Diffusion flow model in estimating fracture widths from tracer tests.

  8. Statistical Physics of Fracture

    SciTech Connect

    Alava, Mikko [Helsinki University of Technology, Helsinki, Finland; Nukala, Phani K [ORNL; Zapperi, Stefano [University of La Sapienza, Rome

    2006-05-01

    Disorder and long-range interactions are two of the key components that make material failure an interesting playfield for the application of statistical mechanics. The cornerstone in this respect has been lattice models of the fracture in which a network of elastic beams, bonds, or electrical fuses with random failure thresholds are subject to an increasing external load. These models describe on a qualitative level the failure processes of real, brittle, or quasi-brittle materials. This has been particularly important in solving the classical engineering problems of material strength: the size dependence of maximum stress and its sample-to-sample statistical fluctuations. At the same time, lattice models pose many new fundamental questions in statistical physics, such as the relation between fracture and phase transitions. Experimental results point out to the existence of an intriguing crackling noise in the acoustic emission and of self-affine fractals in the crack surface morphology. Recent advances in computer power have enabled considerable progress in the understanding of such models. Among these partly still controversial issues, are the scaling and size-effects in material strength and accumulated damage, the statistics of avalanches or bursts of microfailures, and the morphology of the crack surface. Here we present an overview of the results obtained with lattice models for fracture, highlighting the relations with statistical physics theories and more conventional fracture mechanics approaches.

  9. Posterior vertebral rim fractures

    Microsoft Academic Search

    I BEGGS; J ADDISON

    Fracture of the posterior vertebral endplate is a cause of low back pain in adolescents and young adults. Clinically it resembles an acute disc prolapse with low back pain and radiculopa- thy, but may present with neurogenic claudication due to spinal stenosis in older patients. The lesions may be incidental findings. Plain radiographs are diagnostic in about 40% of cases.

  10. Pediatric maxillary fractures.

    PubMed

    Yu, Jack; Dinsmore, Robert; Mar, Philip; Bhatt, Kirit

    2011-07-01

    Pediatric craniofacial structures differ from those of adults in many ways. Because of these differences, management of pediatric craniofacial fractures is not the same as those in adults. The most important differences that have clinical relevance are the mechanical properties, craniofacial anatomy, healing capacity, and dental morphology. This article will review these key differences and the management of pediatric maxillary fractures. From the mechanical properties' perspective, pediatric bones are much more resilient than adult bones; as such, they undergo plastic deformation and ductile failure. From the gross anatomic perspective, the relative proportion of the cranial to facial structures is much larger for the pediatric patients and the sinuses are not yet developed. The differences related to dentition and dental development are more conical crowns, larger interdental spaces, and presence of permanent tooth buds in the pediatric population. The fracture pattern, as a result of all the above, does not follow the classic Le Fort types. The maxillomandibular fixation may require circum-mandibular wires, drop wires, or Ivy loops. Interfragmentary ligatures using absorbable sutures play a much greater role in these patients. The use of plates and screws should take into consideration the future development with respect to growth centers and the location of the permanent tooth buds. Pediatric maxillary fractures are not common, require different treatments, and enjoy better long-term outcomes. PMID:21772207

  11. Fracture design modelling

    SciTech Connect

    Crichlow, H.B.; Crichlow, H.B. (ed.)

    1980-02-07

    A design tool is discussed whereby the various components that enter the design process of a hydraulic fracturing job are combined to provide a realistic appraisal of a stimulation job in the field. An interactive computer model is used to solve the problem numerically to obtain the effects of various parameters on the overall behavior of the system.

  12. Anisotropic ductile fracture

    Microsoft Academic Search

    A. A. Benzerga; J. Besson; A. Pineau

    2004-01-01

    A theory of anisotropic ductile fracture is outlined and applied to predict failure in a low alloy steel. The theory accounts for initial anisotropy and microstructure evolution (plastic anisotropy, porosity, void shape, orientation and spacing) and is supplemented by a recent micromechanical model of void-coalescence. A rate-dependent version of the theory is employed to solve boundary value problems. The application

  13. Numerical simulation research to both the external fixation surgery scheme of intertrochanteric fracture and the healing process, and its clinical application.

    PubMed

    Wang, Xian-Kang; Ye, Jin-Duo; Gu, Fu-Shun; Wang, Ai-guo; Zhang, Chun-Qiu; Tian, Qian-Qian; Li, Xue; Dong, Li-Min

    2014-01-01

    In this paper, the single arm external fixation of intertrochanteric fracture healing process after surgery was simulated to obtain a postoperative fracture healing and stress distribution in the external fixator. Firstly CT images of intertrochanteric fracture are reconstructed into the femur solid model. Then based, the external fixator is installed on the model, which lastly formed a finite element model of unilateral external fixation for intertrochanteric fracture. The calculated results show: during the beginning of the fracture healing, there is much higher stress in both screws and femur in the model with solid screws than that in the model with hollow screw. The stress of the femur in the model with hollow screw is more evenly. During the middle time of Fracture healing, stress in the femoral head significantly decreases. And the stress at fracture site gradually increased with the healing occurrence. According to the results, the authors designed hollow screws to use external fixation surgery. Surgery confirmed that the use of hollow screws in fractures treatment can satisfy the strength requirements, and can effectively reduce operative time, less patient suffering. The research for external fixation can provide a reference, and promote the use of external fixation hollow screws. PMID:24211947

  14. A Case of Generalized Auditory Agnosia with Unilateral Subcortical Brain Lesion

    PubMed Central

    Suh, Hyee; Kim, Soo Yeon; Kim, Sook Hee; Chang, Jae Hyeok; Shin, Yong Beom; Ko, Hyun-Yoon

    2012-01-01

    The mechanisms and functional anatomy underlying the early stages of speech perception are still not well understood. Auditory agnosia is a deficit of auditory object processing defined as a disability to recognize spoken languages and/or nonverbal environmental sounds and music despite adequate hearing while spontaneous speech, reading and writing are preserved. Usually, either the bilateral or unilateral temporal lobe, especially the transverse gyral lesions, are responsible for auditory agnosia. Subcortical lesions without cortical damage rarely causes auditory agnosia. We present a 73-year-old right-handed male with generalized auditory agnosia caused by a unilateral subcortical lesion. He was not able to repeat or dictate but to perform fluent and comprehensible speech. He could understand and read written words and phrases. His auditory brainstem evoked potential and audiometry were intact. This case suggested that the subcortical lesion involving unilateral acoustic radiation could cause generalized auditory agnosia. PMID:23342322

  15. Treatment of unilateral posterior crossbite with facial asymmetry in a female patient with transverse discrepancy.

    PubMed

    Jung, Seok-Ki; Kim, Tae-Woo

    2015-07-01

    A unilateral posterior crossbite with facial asymmetry is difficult to correct with orthodontic treatment alone. This case report describes the orthodontic treatment and additional plasty without orthognathic surgery for a 19-year-old woman with a transverse discrepancy. The posterior crossbite was resolved by expansion of the narrow maxillary arch and space closure in the mandibular arch. This accelerated the correction of the functional shift of the mandible. After resolution of the unilateral posterior crossbite, the problems of the anteroposterior molar relationship were treated using orthodontic mini-implants. Mandibular angle reduction plasty was performed for the asymmetric mandibular border to improve the facial appearance. After treatment, the patient had a more symmetrical facial appearance, normal overjet and overbite, and midline coincidence. The treatment results remained stable 1 year after treatment. This case report demonstrates that a minimally invasive treatment can successfully correct a unilateral posterior crossbite with a transverse discrepancy. PMID:26124038

  16. Fracture management in general practice.

    PubMed

    Wood, T

    1996-09-01

    General practitioners are often confronted with patients who have sustained fractures. A clear understanding of the principles governing fracture management is essential particularly for those GPs who do not have easy access to orthopaedic surgeons. Inappropriately treated fractures can lead to chronic pain and deformity as well as the obvious medico-legal complications. If in doubt over the management of any fracture, obtain a second opinion. This article will aim to cover the important principles of fracture management, using a 'cook's tour' of the body to highlight these principles. PMID:8840559

  17. [Osteoporotic fractures of axial skeleton].

    PubMed

    Scheyerer, M J; Simmen, H-P; Wanner, G A; Werner, C M L

    2012-08-01

    Osteoporotic fractures most frequently first occur in the axial skeleton, especially in the vertebral bodies of the thoracolumbar transition. Beside pain, these fractures cause increasing kyphosis leading to changes in statics and a shift of the bodies' center of gravity. This results in physiological, functional as well as neurological consequences that cannot be managed by means of a conservative therapy. The purpose of this article is to provide a brief overview on diagnostics and therapy of such fractures. Furthermore, fractures of the pubic rami need to be mentioned. They pose another frequent location for osteoporotic fractures and are also associated with a high rate of morbidity and mortality. PMID:22878945

  18. Alinhamento da cabeça de pacientes com hipofunção vestibular periférica unilateral submetidos à fisioterapia aquática para reabilitação vestibular Head alignment on patients with unilateral vestibular hypofunction submitted to aquatic physiotherapy for vestibular rehabilitation

    Microsoft Academic Search

    Yeda Pereira; Lima Gabilan; Karen Renate Mazzetti; Adamar Nunes; Juliana Maria Gazzola; Monica Rodrigues Perracini; Fernando Freitas Ganança

    AIM: To verify the effect of the aquatic physiotherapy protocol for vestibular rehabilitation (APVR) upon the head alignment of patients with unilateral peripheral vestibular hypofunction through computerized biophotogrammetry (CB), and to verify the association between those effects and the variables sex and age. METHOD: Experimental study with a sample of 21 patients with unilateral peripheral vestibular hypofunction, ranging in age

  19. Controversial Issues in Kyphoplasty and Vertebroplasty in Osteoporotic Vertebral Fractures

    PubMed Central

    Papanastassiou, Ioannis D.; Filis, Andreas; Gerochristou, Maria A.; Vrionis, Frank D.

    2014-01-01

    Kyphoplasty (KP) and vertebroplasty (VP) have been successfully employed for many years for the treatment of osteoporotic vertebral fractures. The purpose of this review is to resolve the controversial issues raised by the two randomized trials that claimed no difference between VP and SHAM procedure. In particular we compare nonsurgical management (NSM) and KP and VP, in terms of clinical parameters (pain, disability, quality of life, and new fractures), cost-effectiveness, radiological variables (kyphosis correction and vertebral height restoration), and VP versus KP for cement extravasation and complications profile. Cement types and optimal filling are analyzed and technological innovations are presented. Finally unipedicular/bipedicular techniques are compared. Conclusion. VP and KP are superior to NSM in clinical and radiological parameters and probably more cost-effective. KP is superior to VP in sagittal balance improvement and cement leaking. Complications are rare but serious adverse events have been described, so caution should be exerted. Unilateral procedures should be pursued whenever feasible. Upcoming randomized trials (CEEP, OSTEO-6, STIC-2, and VERTOS IV) will provide the missing link. PMID:24724106

  20. Renography with captopril. Changes in a patient with hypertension and unilateral renal artery stenosis

    SciTech Connect

    Geyskes, G.G.; Oei, H.Y.; Puylaert, C.B.; Dorhout Mees, E.J.

    1986-09-01

    In a 56-year-old man with severe familial hypertension and unilateral renal artery stenosis, captopril induced striking changes in the renograms of the affected kidney. After injection of orthoiodohippurate sodium I 131, the uptake phase was unchanged but the later curve showed continuous accumulation. In contrast, the uptake of technetium Tc 99m diethylenetriamine pentracetic acid was abolished. These changes are compatible with a cessation of filtration and maintenance of renal blood flow. After balloon dilatation of the stenosis, the blood pressure became lower, and these changes could no longer be demonstrated. The captopril renogram may provide useful information on the dependency of hypertension on unilateral renal artery stenosis.

  1. Levator transposition and frontalis sling procedure in severe unilateral ptosis and the paradoxically innervated levator.

    PubMed

    Dryden, R M; Fleming, J C; Quickert, M H

    1982-03-01

    Symmetry in severe unilateral ptosis, the jaw-winking syndrome, and ptosis with aberrant third-nerve regeneration is best achieved with bilateral frontalis suspension. However, the levator function needs to be removed in the normal side with unilateral ptosis and bilaterally with the paradoxically innervated levator. Levator transposition to the arcus marginalis is a reversible methods of establishing a complete ptosis. the reversibility of the procedure is demonstrated in the rhesus monkey. The procedure, when combined with frontalis suspension in humans, demonstrates the needed elimination of levator function. PMID:7065968

  2. Ambiguous genitalia in a fertile, unilaterally cryptorchid male miniature schnauzer dog.

    PubMed

    Breshears, M A; Peters, J L

    2011-09-01

    A 7-year-old male miniature schnauzer dog with unilateral cryptorchidism was presented for elective orchiectomy. Surgery to remove the cryptorchid testis revealed a fully formed uterus with horns attached to both testis and the body and cervix terminating at the prostate gland. The gross and microscopic diagnosis for the genital tract was persistent Müllerian duct syndrome with unilateral cryptorchidism. Additional associated lesions included cystic endometrial hyperplasia and a solitary, intratubular seminoma within the undescended testis. Persistent Müllerian duct syndrome is rare among domestic animals but is more common in miniature schnauzer dogs because of inheritance as an autosomal recessive trait. PMID:21248100

  3. [Unilateral Creutzfeld-Jakob disease: report of a probable case on electroclinical, MRI and biological criteria].

    PubMed

    Moisset, X; Vitello, N; Cornut-Chauvinc, C; Taithe, F; Dionet, E; Lauxerois, M; Guy, N; Clavelou, P

    2013-02-01

    We report the case of a 70-year-old man who developed probable unilateral Creutzfeldt-Jakob disease. Clinically, he presented with right hemiparesis, progressive aphasia, temporospatial disorientation and cerebellar ataxia and later on, myoclonia. The MRI showed a hypersignal from the left caudate in DWI with decreased ADC. Repeated electroencephalograms showed a slow background rhythm in the left hemisphere with superimposed periodic, biphasic and triphasic sharp-wave complexes in the left temporal region. Death occurred after 5weeks. Although exceptional, unilateral Creutzfeldt-Jakob disease was retained as possible. PMID:23079855

  4. Management of Unilateral Masseter Hypertrophy and Hypertrophic Scar—A Case Report

    PubMed Central

    Shetty, Naresh; Malaviya, Rajanikanth K.; Gupta, M. K.

    2012-01-01

    Masseter muscle hypertrophy is a rare condition of idiopathic cause. It clinically presents as an enlargement of one or both masseter muscles. Most patients complain of facial asymmetry; however, symptoms such as trismus, protrusion, and bruxism may also occur. Several treatment options reported for masseter hypertrophy are present, which range from simple pharmacotherapy to more invasive surgical reduction. Keloid scar with unilateral masseter hypertrophy is a rarely seen in clinical practice. This paper reports a case of unilateral masseter hypertrophy with keloid scar in the angle of the mandible for which surgical treatment was rendered to the patient by using a single approach. PMID:22844620

  5. Performance of Adults with Auditory Figure-Ground Disorders under Conditions of Unilateral and Bilateral Ear Occlusion.

    ERIC Educational Resources Information Center

    Hasbrouck, Jon M.

    1987-01-01

    The effects of unilateral and bilateral ear occlusion on auditory discrimination in background noise was tested among 36 adults with auditory figure-ground disorders and normal auditory discrimination ability. Results indicated that unilateral occlusion effectively eliminated the figure-ground disorder in most subjects. (Author/DB)

  6. Fracture mechanics validity limits

    NASA Technical Reports Server (NTRS)

    Lambert, Dennis M.; Ernst, Hugo A.

    1994-01-01

    Fracture behavior is characteristics of a dramatic loss of strength compared to elastic deformation behavior. Fracture parameters have been developed and exhibit a range within which each is valid for predicting growth. Each is limited by the assumptions made in its development: all are defined within a specific context. For example, the stress intensity parameters, K, and the crack driving force, G, are derived using an assumption of linear elasticity. To use K or G, the zone of plasticity must be small as compared to the physical dimensions of the object being loaded. This insures an elastic response, and in this context, K and G will work well. Rice's J-integral has been used beyond the limits imposed on K and G. J requires an assumption of nonlinear elasticity, which is not characteristic of real material behavior, but is thought to be a reasonable approximation if unloading is kept to a minimum. As well, the constraint cannot change dramatically (typically, the crack extension is limited to ten-percent of the initial remaining ligament length). Rice, et al investigated the properties required of J-type parameters, J(sub x), and showed that the time rate, dJ(sub x)/dt, must not be a function of the crack extension rate, da/dt. Ernst devised the modified-J parameter, J(sub M), that meets this criterion. J(sub M) correlates fracture data to much higher crack growth than does J. Ultimately, a limit of the validity of J(sub M) is anticipated, and this has been estimated to be at a crack extension of about 40-percent of the initial remaining ligament length. None of the various parameters can be expected to describe fracture in an environment of gross plasticity, in which case the process is better described by deformation parameters, e.g., stress and strain. In the current study, various schemes to identify the onset of the plasticity-dominated behavior, i.e., the end of fracture mechanics validity, are presented. Each validity limit parameter is developed in detail, and then data is presented and the various schemes for establishing a limit of the validity are compared. The selected limiting parameter is applied to a set of fracture data showing the improvement of correlation gained.

  7. Fracture fixation problems in osteoporosis.

    PubMed

    Strømsøe, Knut

    2004-02-01

    Osteoporosis, or loss of bone mass and microarchitectural deterioration of bone tissue, does not only enhance risk of fracture but also represents a problem in osteofixation of fractures in fracture treatment. Aging of the western population changes the epidemiology of fractures. An increasing socioeconomic interest in geriatric traumatology makes the need for much urgent study in the field of osteoporotic fractures self evident. It is no longer the province of only one medical group to look for fragmented solutions in the treatment of osteoporotic fractures. Efforts have to be united across professional boundaries to meet the challenge of this problem. Assessment of bone mineral may be used in evaluation of fracture risk but also in the choice of implant as well as in the design of implants used in fracture treatment. The differences in mechanical properties of different types of bone in the same individual have to be respected. Changes in the pattern of fractures and problems with implant anchorage in bone, due to a demographic increase in patients with osteoporosis remain problems requiring new solutions. Still basic principals in fracture treatment may not be eclipsed by new fixation devices. PMID:14736465

  8. Fractures of the cervical spine

    PubMed Central

    Marcon, Raphael Martus; Cristante, Alexandre Fogaça; Teixeira, William Jacobsen; Narasaki, Douglas Kenji; Oliveira, Reginaldo Perilo; de Barros Filho, Tarcísio Eloy Pessoa

    2013-01-01

    OBJECTIVES: The aim of this study was to review the literature on cervical spine fractures. METHODS: The literature on the diagnosis, classification, and treatment of lower and upper cervical fractures and dislocations was reviewed. RESULTS: Fractures of the cervical spine may be present in polytraumatized patients and should be suspected in patients complaining of neck pain. These fractures are more common in men approximately 30 years of age and are most often caused by automobile accidents. The cervical spine is divided into the upper cervical spine (occiput-C2) and the lower cervical spine (C3-C7), according to anatomical differences. Fractures in the upper cervical spine include fractures of the occipital condyle and the atlas, atlanto-axial dislocations, fractures of the odontoid process, and hangman's fractures in the C2 segment. These fractures are characterized based on specific classifications. In the lower cervical spine, fractures follow the same pattern as in other segments of the spine; currently, the most widely used classification is the SLIC (Subaxial Injury Classification), which predicts the prognosis of an injury based on morphology, the integrity of the disc-ligamentous complex, and the patient's neurological status. It is important to correctly classify the fracture to ensure appropriate treatment. Nerve or spinal cord injuries, pseudarthrosis or malunion, and postoperative infection are the main complications of cervical spine fractures. CONCLUSIONS: Fractures of the cervical spine are potentially serious and devastating if not properly treated. Achieving the correct diagnosis and classification of a lesion is the first step toward identifying the most appropriate treatment, which can be either surgical or conservative. PMID:24270959

  9. Dynamic fracture of ceramics

    NASA Astrophysics Data System (ADS)

    Buchar, J.; Rolc, S.

    2006-08-01

    The aim of the paper consists in the comparison of two experimental methods which are used for the study of the ceramics fracture under dynamic loading. The experimental study has been performed for the specimen of the Al{2}O{3}. The loading has been performed using of the Taylor test. The impact velocity when the fracture of the specimen starts has been determined. Using of the numerical simulation of the given test, the dynamic strength of the given material has been evaluated. In the next step, the dynamic Brazilian tests has been performed with a Hopkinson bar, at strain rates 76 s-1. The numeric simulation showed the agreement between results of both methods.

  10. Pelvic and acetabular fractures

    SciTech Connect

    Mears, D.C.; Rubash, H.E.

    1986-01-01

    This treatise focuses primarily on the clinical aspects of diagnosis and treatments of pelvic and acetabular fractures. However, considerable attention is also paid to the radiographic diagnosis of trauma and postoperative effects. The book begins with a succinct review of pelvic and acetabular anatomy and pelvic biomechanics. It continues with a radiographic classification of pelvic injury, which will represent the major source of the book's interest for radiologists. The remainder of the book is concerned with clinical management of pelvic and acetabular trauma, including preoperative planning, surgical approaches, techniques of reduction, internal fixation, eternal fixation, post-operative care, and late problems. Even throughout this later portion of the book there are extensive illustrations, including plain radiographs, computed tomographic (CT) scans, reconstructed three-dimensional CT scans, and schematic diagrams of diverse pelvic and acetabular fractures and the elementary surgical techniques for their repair.

  11. Fracture Modeling and Flow Behavior in Shale Gas Reservoirs Using Discrete Fracture Networks 

    E-print Network

    Ogbechie, Joachim Nwabunwanne

    2012-02-14

    Gen and NFflow) for fracture modeling of a shale gas reservoir and also studies the interaction of the different fracture properties on reservoir response. The most important results of the study are that a uniform fracture network distribution and fracture...

  12. Relative Dating Via Fractures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    This VIS image of the eastern part of the Tharsis region illustrates how fractures can be used in relative dating of a surface. The fractured materials on the right side of the image are embayed by younger volcanic flows originating to the west of the image. Note how the younger flows cover the ends of the fractures, and are not at all fractured themselves.

    Image information: VIS instrument. Latitude 43.2, Longitude 269.4 East (90.6 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Melt fracture revisited

    SciTech Connect

    Greenberg, J. M.

    2003-07-16

    In a previous paper the author and Demay advanced a model to explain the melt fracture instability observed when molten linear polymer melts are extruded in a capillary rheometer operating under the controlled condition that the inlet flow rate was held constant. The model postulated that the melts were a slightly compressible viscous fluid and allowed for slipping of the melt at the wall. The novel feature of that model was the use of an empirical switch law which governed the amount of wall slip. The model successfully accounted for the oscillatory behavior of the exit flow rate, typically referred to as the melt fracture instability, but did not simultaneously yield the fine scale spatial oscillations in the melt typically referred to as shark skin. In this note a new model is advanced which simultaneously explains the melt fracture instability and shark skin phenomena. The model postulates that the polymer is a slightly compressible linearly viscous fluid but assumes no slip boundary conditions at the capillary wall. In simple shear the shear stress {tau}and strain rate d are assumed to be related by d = F{tau} where F ranges between F{sub 2} and F{sub 1} > F{sub 2}. A strain rate dependent yield function is introduced and this function governs whether F evolves towards F{sub 2} or F{sub 1}. This model accounts for the empirical observation that at high shears polymers align and slide more easily than at low shears and explains both the melt fracture and shark skin phenomena.

  14. Rehabilitation in extremity fractures.

    PubMed

    Moskowitz, E

    1975-03-01

    General principles in the rehabilitation of a patient with an extremity fracture include: treat the patient, not the x-ray; move all joints not immobilized; prevent disuse atrophy; use gravity to assist in mobilizing a joint; stabilize proximal joints to avoid reverse action of biarticular muscles; permit early protected weight bearing until adequate joint mobility is achieved; appropriately instruct the patient in a home program, and avoid all stretching. PMID:1114932

  15. Fractured Craters on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two highly fractured craters are visible in this high resolution image of Jupiter's moon, Ganymede. NASA's Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the Jovian system. North is to the top of the picture and the sun illuminates the surface from the southeast. The two craters in the center of the image lie in the ancient dark terrain of Marius Regio, at 40 degrees latitude and 201 degrees longitude, at the border of a region of bright grooved terrain known as Byblus Sulcus (the eastern portion of which is visible on the left of this image). Pervasive fracturing has occurred in this area that has completely disrupted these craters and destroyed their southern and western walls. Such intense fracturing has occurred over much of Ganymede's surface and has commonly destroyed older features. The image covers an area approximately 26 kilometers (16 miles) by 18 kilometers (11 miles) across at a resolution of 86 meters (287 feet) per picture element. The image was taken on September 6, 1996 by the solid state imaging (CCD) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  16. Posterior pelvic ring fractures: Closed reduction and percutaneous CT-guided sacroiliac screw fixation

    SciTech Connect

    Jacob, Augustinus Ludwig [Kantonsspital-Universitaetskliniken, Institute of Diagnostic Radiology (Switzerland); Messmer, Peter [Kantonsspital-Universitaetskliniken, Department of Surgery (Switzerland); Stock, Klaus-Wilhelm [Kantonsspital-Universitaetskliniken, Institute of Diagnostic Radiology (Switzerland); Suhm, Norbert [Kantonsspital-Universitaetskliniken, Department of Surgery (Switzerland); Baumann, Bernard [Kantonsspital-Universitaetskliniken, Institute of Diagnostic Radiology (Switzerland); Regazzoni, Pietro [Kantonsspital-Universitaetskliniken, Department of Surgery (Switzerland); Steinbrich, Wolfgang [Kantonsspital-Universitaetskliniken, Institute of Diagnostic Radiology (Switzerland)

    1997-07-15

    Purpose. To assess the midterm results of closed reduction and percutaneous fixation (CRPF) with computed tomography (CT)-guided sacroiliac screw fixation in longitudinal posterior pelvic ring fractures. Methods. Thirteen patients with 15 fractures were treated. Eleven patients received a unilateral, two a bilateral, screw fixation. Twenty-seven screws were implanted. Continuous on-table traction was used in six cases. Mean radiological follow-up was 13 months. Results. Twenty-five (93%) screws were placed correctly. There was no impingement of screws on neurovascular structures. Union occurred in 12 (80%), delayed union in 2 (13%), and nonunion in 1 of 15 (7%) fractures. There was one screw breakage and two axial dislocations. Conclusion. Sacroiliac CRPF of longitudinal fractures of the posterior pelvic ring is technically simple, minimally invasive, well localized, and stable. It should be done by an interventional/surgical team. CT is an excellent guiding modality. Closed reduction may be a problem and succeeds best when performed as early as possible.

  17. Evaluation of Five Fracture Models in Taylor Impact Fracture

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Xiao, Xinke; Wei, Gang; Guo, Zitao

    2011-06-01

    Taylor impact test presented in a previous study on a commercial high strength and super hard aluminum alloy 7A04-T6 are numerically evaluated using the finite element code ABAQUS/Explicit. In the present study, the influence of fracture criterion in numerical simulations of the deformation and fracture behavior of Taylor rod has been studied. Included in the paper are a modified version of Johnson-Cook, the Cockcroft-Latham(C-L), the constant fracture strain, the maximum shear stress and the maximum principle stress fracture models. Model constants for each criterion are calibrated from material tests. The modified version of Johnson-Cook fracture criterion with the stress triaxiality cut off idea is found to give good prediction of the Taylor impact fracture behavior. However, this study will also show that the C-L fracture criterion where only one simple material test is required for calibration, is found to give reasonable predictions. Unfortunately, the other three criteria are not able to repeat the experimentally obtained fracture behavior. The study indicates that the stress triaxiality cut off idea is necessary to predict the Taylor impact fracture. The National Natural Science Foundation of China (No.: 11072072).

  18. Upper Limb Function and Cortical Organization in Youth with Unilateral Cerebral Palsy

    PubMed Central

    Mackey, Anna; Stinear, Cathy; Stott, Susan; Byblow, Winston D.

    2014-01-01

    Aim: To explore the relationship between motor cortical and descending motor pathway reorganization, lesion type, and upper limb function in youth with unilateral cerebral palsy (CP). Methods: Twenty participants with unilateral CP (mean age 15?±?3?years; 11 males) completed a range of upper limb functional measures. Structural MRI, diffusion-weighted, and functional MRI were conducted to determine type and extent of brain lesion, descending white matter integrity, and whole-brain activity during affected hand use. Single pulse transcranial magnetic stimulation (TMS) (n?=?12) was used to examine functional integrity of the corticospinal pathway as well as primary motor cortex intracortical and interhemispheric inhibition from motor-evoked potentials and silent periods. Results: Fractional anisotropy measures within the posterior limb of the internal capsule were a predictor of upper limb function (R2?=?0.41, F?=?11.3, p?=?0.004). Participants with periventricular lesions tended to have better upper limb function [F(2, 17)?=?42.48, p?Unilateral Upper Limb Function: Mann Whitney p?=?0.02). Conclusion: Neuroimaging and TMS can provide useful information related to hand function of individuals with unilateral CP and may have potential to assist as a predictive tool and/or guide rehabilitation. PMID:25071705

  19. Side by side treadmill walking reduces gait asymmetry induced by unilateral ankle weight.

    PubMed

    Nessler, Jeff A; Gutierrez, Veronica; Werner, Judea; Punsalan, Andrew

    2015-06-01

    Asymmetric gait is a hallmark of many neurological and musculoskeletal conditions. This behavior is often the result of a decrease in the stability of interlimb coordination, and synchronization to external signals such as auditory cuing or another walking individual may be helpful for altering abnormal movement patterns. The purpose of this study was to investigate the interaction between interlimb coordination and unintentional, interpersonal synchronization of gait in healthy individuals in response to unilateral ankle loading. Fifty participants completed four trials while walking on a motorized treadmill: (1) by themselves, (2) with a partner on an adjacent treadmill, (3) by themselves with additional weight applied unilaterally to their right ankle, and (4) with both a partner and unilateral weight. As expected, the addition of unilateral weight increased asymmetry according to several spatiotemporal measures of gait, but the presence of a partner on an adjacent treadmill significantly reduced this effect. Further, the amount of unintentional, interpersonal synchronization among pairings was relatively unaffected by the addition of ankle weight to one of the partners. All pairings realized a beneficial effect on asymmetrical gait but this effect was greater for pairings that consistently synchronized unintentionally. These results suggest that side by side walking might be an effective approach for influencing bilateral coordination of gait and may hold insight for understanding gait asymmetry and interlimb movement variability. PMID:25744595

  20. Long term outcome of unilateral pallidotomy: follow up of 15 patients for 3 years

    Microsoft Academic Search

    P K Pal; A Samii; A Kishore; M Schulzer; E Mak; S Yardley; I M Turnbull; D B Calne

    2000-01-01

    OBJECTIVESWith the advent of new antiparkinsonian drug therapy and promising results from subthalamic and pallidal stimulation, this study evaluated the long term efficacy of unilateral pallidotomy, a technique which has gained popularity over the past decade for the management of advanced Parkinson's disease.METHODSThe 15 patients reported here are part of the original cohort of 24 patients who underwent posteroventral pallidotomy

  1. Unilateral divorce versus child custody and child support in the U.S

    Microsoft Academic Search

    Rafael González-Val; Miriam Marcén

    2011-01-01

    This paper explores the response of the divorce rate to law reforms introducing unilateral divorce after controlling for law reforms concerning the aftermath of divorce, which are omitted from most previous studies. We introduce two main policy changes that have swept the US since the late 1970s: the approval of the joint custody regime and the Child Support Enforcement program.

  2. Loading of a Unilateral Temporomandibular Joint Prosthesis: A Three-dimensional Mathematical Study

    Microsoft Academic Search

    J.-P. van Loon; E. Otten; C. H. Falkenström; L. G. M. de Bont; G. J. Verkerke

    1998-01-01

    The load on the prosthetic side and the influence of the design on the remaining natural contralateral TMJ must be known before a unilateral temporomandibular joint (TMJ) prosthesis can be developed. The aim of the present study was to determine the maximum loading of the TMJ prosthetic side and the natural contralateral TMJ and to investigate the influence of the

  3. Q What is a unilateral hearing loss? What causes a hearing loss in only one ear?

    E-print Network

    O'Toole, Alice J.

    Q· What is a unilateral hearing loss? · What causes a hearing loss in only one ear? · Will the hearing in my child's better ear get worse? · Why would my child have trouble hearing if one ear has normal hearing? · Will my child benefit from wearing a hearing aid in the ear with the hearing loss

  4. A Model of Transient Unilateral Focal Ischemia With Reperfusion in the P7 Neonatal Rat

    E-print Network

    Cossart, Rosa

    A Model of Transient Unilateral Focal Ischemia With Reperfusion in the P7 Neonatal Rat. Charriaut-Marlangue, PhD Background and Purpose--The mechanisms leading to delayed cell death after hypoxic of transient focal ischemia in the neonatal rat in an attempt to create a reperfusion phase since

  5. A Comparative Study to Evaluate the Functional Effect of Unilateral Uvuloplasty after Primary Palatoplasty

    PubMed Central

    Olivencia-Flores, Claudia; Gavino-Gutierrez, Arquímedes M.; Caceres-Nano, Evelyn; Cotrina-Rabanal, Omar

    2015-01-01

    Background: The conventional method for uvular repair suturing the 2 hemi-uvulas of the palatal cleft together in the midline does not allow us to obtain a proper anatomical repair. In our hands, the midline straight closure frequently causes retraction of the uvular tissues with the consequent abnormal appearance of the uvula. We described before a method for uvular repair in patients with cleft palate. The technique consists in preserving one of the hemi-uvulas, which is moved to the midline to form the definitive uvula. The purpose of this study was to evaluate the functional effects of the unilateral uvuloplasty for uvular repair in a group of patients with bilateral cleft palate. Methods: This is a retrospective, single-blinded cohort study between 2 groups of 90 patients with bilateral cleft palate who were operated on using the conventional and unilateral uvuloplasty methods of uvular repair from 2000 to 2009. Data collection was accomplished by physical examination to evaluate the presence of postoperative fistulas and hypernasal speech determined at 6 months to 5 years after surgery. In addition, postoperative dimensions of the velopharynx were measured by a single-blind examiner using a computed tomography scan. Results: Our comparative study found statistically significant differences between the 2 groups in favor of the unilateral uvuloplasty group. Conclusions: We observed that the use of unilateral uvuloplasty for uvular reconstruction reduces the velopharyngeal space and the frequency of hypernasality in patients with bilateral cleft palate. PMID:26180716

  6. A battery of tests for the quantitative assessment of unilateral neglect 1

    Microsoft Academic Search

    Philippe Azouvi; Paolo Bartolomeo; Jean-Marie Beis; Dominic Perennou; Pascale Pradat-Diehl; Marc Rousseaux

    2006-01-01

    Purpose: The lack of agreement regarding assessment methods is responsible for the variability in the reported rate of occurrence of unilateral neglect (UN) after stroke. In addition, dissociations have been reported between performance on traditional paper-and-pencil tests and UN in everyday life situations. Methods: In this paper, we present the validation studies of a quantitative test battery for UN, including

  7. Measuring Unilateral Market Power in Wholesale Electricity Markets: The California Market, 1998–2000

    Microsoft Academic Search

    Frank A. Wolak

    2003-01-01

    This paper measures the unilateral incentive each of the five largest electricity suppliers in California had to exercise market power in the state's wholesale market during the four-month period from 1 June to 30 September of 1998, 1999, and 2000. Using the actual bids submitted to the California Independent System Opera- tor's (CAISO) real-time energy market, I com- pute the

  8. Comparison of the Electromyographic Activation Level and Unilateral Selectivity of Erector Spinae during Different Selected Movements

    ERIC Educational Resources Information Center

    Guo, Lan-Yuen; Wang, Yu-Lin; Huang, Yu-Han; Yang, Chich-Haung; Hou, Yi-You; Harn, Hans I-Chen; You, Yu-Lin

    2012-01-01

    For patients with scoliosis, core stabilization exercises may be beneficial in improving muscle strength and trunk dynamic control. However, few studies have examined whether the erector spinae (ES) activation status during unilateral spinal extensor strengthening meets the guideline for patients with spinal scoliosis. To determine ES activation…

  9. Ocular Rotation Axes during Dynamic Bielschowsky Head-Tilt Testing in Unilateral Trochlear Nerve Palsy

    E-print Network

    Haslwanter, Thomas

    Ocular Rotation Axes during Dynamic Bielschowsky Head-Tilt Testing in Unilateral Trochlear Nerve inward relative to the other axis. This convergence of axes increased with gaze toward the unaffected parallel to the paretic SO in the covered unaffected eye. The horizontal incomitance of rotation axes along

  10. The Course and Outcome of Unilateral Intracranial Arteriopathy in 79 Children with Ischaemic Stroke

    ERIC Educational Resources Information Center

    Braun, K. P. J.; Bulder, M. M. M.; Chabrier, S.; Kirkham, F. J.; Uiterwaal, C. S. P.; Tardieu, M.; Sebire, G.

    2009-01-01

    Arteriopathies are the commonest cause of arterial ischaemic stroke (AIS) in children. Repeated vascular imaging in children with AIS demonstrated the existence of a "transient cerebral arteriopathy" (TCA), characterized by lenticulostriate infarction due to non-progressive unilateral arterial disease affecting the supraclinoid internal carotid…

  11. Why Bilateral Damage Is Worse than Unilateral Damage to the Brain

    E-print Network

    McClelland, James L. "Jay"

    in the 1950s, when Scoville produced a profound memory loss in patient HM by removing the hippocampus bilaterally. Scovilles motivation for publish- ing these findings was not only to warn other neuro- surgeons patients after unilateral resections, in whom the observed memory deficit is relatively mild (Scoville

  12. Verbal Competence in Narrative Retelling in 5-Year-Olds with Unilateral Cleft Lip and Palate

    ERIC Educational Resources Information Center

    Klintö, Kristina; Salameh, Eva-Kristina; Lohmander, Anette

    2015-01-01

    Background: Research regarding expressive language performance in children born with cleft palate is sparse. The relationship between articulation/phonology and expressive language skills also needs to be further explored. Aims: To investigate verbal competence in narrative retelling in 5-year-old children born with unilateral cleft lip and palate…

  13. COMPARISON OF BILATERAL VERSUS UNILATERAL VARICOCELECTOMY IN MEN WITH PALPABLE BILATERAL VARICOCELES

    Microsoft Academic Search

    DOUGLAS SCHERR; MARC GOLDSTEIN

    1999-01-01

    PurposeThe left varicocele is usually larger in men with bilateral varicoceles. We hypothesized that most of the benefit of varicocelectomy would derive from repair of the larger varicocele. To test this hypothesis we prospectively compared the effect of unilateral versus bilateral microsurgical varicocelectomy in men with large (grade III) or moderate (II) left varicocele associated with small but palpable (I)

  14. Gender Differences in Unilateral Spatial Neglect within 24 Hours of Ischemic Stroke

    ERIC Educational Resources Information Center

    Kleinman, Jonathan T.; Gottesman, Rebecca F.; Davis, Cameron; Newhart, Melissa; Heidler-Gary, Jennifer; Hillis, Argye E.

    2008-01-01

    Hemispatial neglect is a common and disabling consequence of stroke. Previous reports examining the relationship between gender and the incidence of unilateral spatial neglect (USN) have included either a large numbers of patients with few neglect tests or small numbers of patients with multiple tests. To determine if USN was more common and/or…

  15. Sex Similarities in Verbal and Performance IQ Deficits Following Unilateral Cerebral Lesions.

    ERIC Educational Resources Information Center

    Herring, Sheldon; Reitan, Ralph M.

    1986-01-01

    Investigated whether men and women produced similar Verbal Intelligence Quotient (IQ) and Performance IQ patterns following unilateral cerebral lesions. No consistent evidence of Sex X Lesioned Hemisphere interactions was found. Differences in the lateralization effects between men and women were not reflected in direction or pattern but only in…

  16. Long-Term Renal Function in the Posterior Urethral Valves, Unilateral Reflux and Renal Dysplasia Syndrome

    Microsoft Academic Search

    Peter M. Cuckow; M. D. Dinneen; R. A. Risdon; P. G. Ransley; P. G. Duffy

    1997-01-01

    PurposeThe syndrome of posterior urethral valves, persistent unilateral reflux and renal dysplasia (VURD) is said to be protective of the contralateral nonrefluxing kidney and the outcome for renal function is reported to be excellent. We tested this hypothesis in our patients by replicating previous studies but with longer followup and glomerular filtration rate data.

  17. Audiol Neurootol 2000;5:225234 Unilateral Neglect after Right-Hemisphere

    E-print Network

    Deouell, Leon Y.

    of the lesion [De Renzi et al., 1984; Heilman et al., 1970; Rapcsak et al., 1987]. Both unilateral neglect], suggesting that the #12;226 Audiol Neurootol 2000;5:225­234 Deouell/Hämäläinen/Bentin source of the disorder also be manifested in the auditory and tac- tile modalities [De Renzi et al., 1984, 1989; Soroker et al

  18. Language-specific dysgraphia in Korean patients with right brain stroke: influence of unilateral spatial neglect.

    PubMed

    Jang, Dae-Hyun; Kim, Min-Wook; Park, Kyoung Ha; Lee, Jae Woo

    2015-03-01

    The purpose of the present study was to investigate the relationship between Korean language-specific dysgraphia and unilateral spatial neglect in 31 right brain stroke patients. All patients were tested for writing errors in spontaneous writing, dictation, and copying tests. The dysgraphia was classified into visuospatial omission, visuospatial destruction, syllabic tilting, stroke omission, stroke addition, and stroke tilting. Twenty-three (77.4%) of the 31 patients made dysgraphia and 18 (58.1%) demonstrated unilateral spatial neglect. The visuospatial omission was the most common dysgraphia followed by stroke addition and omission errors. The highest number of errors was made in the copying and the least was in the spontaneous writing test. Patients with unilateral spatial neglect made a significantly higher number of dysgraphia in the copying test than those without. We identified specific dysgraphia features such as a right side space omission and a vertical stroke addition in Korean right brain stroke patients. In conclusion, unilateral spatial neglect influences copy writing system of Korean language in patients with right brain stroke. PMID:25729257

  19. "No-Show": Therapist Racial/Ethnic Disparities in Client Unilateral Termination

    ERIC Educational Resources Information Center

    Owen, Jesse; Imel, Zac; Adelson, Jill; Rodolfa, Emil

    2012-01-01

    In the present study, the authors examined the source of racial/ethnic minority (REM) disparities in unilateral termination (i.e., the client ending therapy without informing the therapist)--a form of dropout that is associated with poor alliance and outcome. First, the authors tested whether some therapists were more likely to have clients who…

  20. Post unilateral lesion response biases modulate memory: Crossed double dissociation of hemispheric specialisations

    Microsoft Academic Search

    Claude M. J. Braun; Josée Delisle; Anik Guimond; Rafaël Daigneault

    2009-01-01

    We propose that what appears to be hemispheric specialisation in the memory domain, as indexed by effects of unilateral brain lesions, is to a great extent explainable as response bias: left hemisphere lesions result in an omissive response bias or error pattern whereas right hemisphere lesions result in a commissive response bias or error pattern. To test this prediction a

  1. Unilateral recession–resection in children with exotropia of the convergence insufficiency type

    Microsoft Academic Search

    M Y Choi; S-M Hyung; J-M Hwang

    2007-01-01

    PurposeThe surgical success rates for intermittent exotropia of the convergence insufficiency type have been reported to be variable, and most were studied retrospectively in adults. The purpose of this study was to evaluate prospectively the long-term surgical results of unilateral lateral rectus (LR) muscle recession and medial rectus (MR) muscle resection in children with intermittent exotropia of the convergence insufficiency

  2. Domain decomposition methods for problems of unilateral contact between elastic bodies with nonlinear Winkler covers

    E-print Network

    Ihor I. Prokopyshyn; Ivan I. Dyyak; Rostyslav M. Martynyak; Ivan A. Prokopyshyn

    2012-11-30

    In this paper we propose on continuous level a class of domain decomposition methods of Robin-Robin type to solve the problems of unilateral contact between elastic bodies with nonlinear Winkler covers. These methods are based on abstract nonstationary iterative algorithms for nonlinear variational equations in reflexive Banach spaces. We also provide numerical investigations of obtained methods using finite element approximations.

  3. New approach to management of unilateral tension pulmonary interstitial emphysema in premature infants.

    PubMed

    Swingle, H M; Eggert, L D; Bucciarelli, R L

    1984-09-01

    Conservative management of unilateral tension pulmonary interstitial emphysema is reported. Treatment consisted of (1) positioning the infant on his or her side with the emphysematous lung dependent, (2) minimal chest physiotherapy and endotracheal suctioning, and (3) appropriate ventilator management. Conservative therapy is effective and appears to be safer than selective bronchial intubation or surgical therapy. PMID:6472967

  4. Action Planning in Typically and Atypically Developing Children (Unilateral Cerebral Palsy)

    ERIC Educational Resources Information Center

    Craje, Celine; Aarts, Pauline; Nijhuis-van der Sanden, Maria; Steenbergen, Bert

    2010-01-01

    In the present study, we investigated the development of action planning in children with unilateral Cerebral Palsy (CP, aged 3-6 years, n = 24) and an age matched control group. To investigate action planning, participants performed a sequential movement task. They had to grasp an object (a wooden play sword) and place the sword in a hole in a…

  5. Unilateral syphilitic perioptic neuritis in a patient coinfected with human immunodeficiency virus type 1.

    PubMed

    Basta, Medhat S T; Sankar, K Nathan; Dayan, Margaret

    2007-06-01

    Perioptic neuritis caused by secondary syphilis is a rare ophthalmic manifestation in the HIV-infected host. Early diagnosis and treatment of this condition is required to prevent further visual damage. We report a case of unilateral syphilitic perioptic neuritis in a patient coinfected with HIV-1. PMID:17569719

  6. Asymmetrical use of eye information from faces following unilateral amygdala damage

    E-print Network

    Gosselin, Frédéric

    Asymmetrical use of eye information from faces following unilateral amygdala damage Fre, Pasadena, CA 91101, USA The human amygdalae are involved in processing visual information about the eyes with real people. However, the roles played here by the left and right amygdala individually remain unknown

  7. Differentially expressed DNA sequences following recovery from unilateral testicular torsion in rat

    Microsoft Academic Search

    Farag A. Ahmed; Anne M. Jequier; James M. Cummins; James Whelan

    2001-01-01

    The molecular response during recovery from torsion-induced stress in the testis is diverse with a variety of mechanisms. In this study, using unilateral testicular torsion in rat as a model, we used subtractive hybridisation to identify differentially expressed DNA sequences in the torsioned and control testes. Three genes were identified as being down regulated in the torsioned testis compared with

  8. Damage Induced Anisotropy: On the Difficulties Associated with the Active\\/Passive Unilateral Condition

    Microsoft Academic Search

    J.-L. Chaboche

    1992-01-01

    Continuum damage theories have been developed that incorporate both the damage induced anisotropy and the unilateral effect of damage. Four of them are discussed in this paper using respectively scalar damage variables, vectors, second-order tensors, and fourth-order damage tensors.

  9. Unilateral lesions of the globus pallidus: report of four patients presenting with focal or segmental dystonia

    PubMed Central

    Munchau, A; Mathen, D; Cox, T; Quinn, N; Marsden, C; Bhatia, K

    2000-01-01

    OBJECTIVES—To interpret clinical features after unilateral lesions of the globus pallidus on the basis of physiology of the basal ganglia.?METHODS—Four patients with unilateral lesions in the globus pallidus (GP) were clinically examined and the literature on patients with pallidal lesions was reviewed.?RESULTS—Three patients presented with contralateral dystonia largely confined to one arm in one case and one leg in two cases. One patient had predominant contralateral hemiparkinsonism manifested mainly as micrographia and mild dystonia in one arm. The cause of the lesions was unknown in two patients. In the other two symptoms had developed after head trauma and after anoxia. All lesions involved the internal segment of the GP. Two patients, including the patient with hemiparkinsonism, had additional involvement of the external segment of the GP. In the literature reports on 26 patients with bilateral lesions restricted to the GP only two with unilateral lesions were found. The patients with bilateral pallidal lesions manifested with dystonia, parkinsonism, or abulia. One of the patients with unilateral GP lesions had contralateral hemidystonia, the other contralateral arm tremor.?CONCLUSION—These cases emphasise the importance of the GP, particularly its internal segment, in the pathophysiology of dystonia.?? PMID:10990510

  10. Unilateral laminotomy for bilateral decompression of lumbar spinal stenosis part II: Clinical experiences

    Microsoft Academic Search

    U. Spetzger; H. Bertalanffy; M. H. T. Reinges; J. M. Gilsbach

    1997-01-01

    Summary The surgical aim in the treatment of symptomatic lumbar spinal stenosis is the relief of the patient's complaints by an adequate neural decompression. Unilateral laminotomy and bilateral spinal canal decompression represents such a safe, effective and minimally invasive surgical method. This technique has been successfully used in the operative treatment of 29 patients with symptomatic mono- or multisegmental lumbar

  11. Hydraulic fracture propagation in layered formations

    Microsoft Academic Search

    Daneshy

    1976-01-01

    This paper reports theoretical and experimental developments on propagation of hydraulic fractures in layered formations. Experimentally, it is shown that unobstructed fractures propagate with a decreasing fracturing fluid pressure. This general trend is in agreement with theoretical predictions. Obstructions to fracture propagation result in an increase in fluid pressure. Also, it is shown that the relative fracturability of rocks can

  12. Repair of long bone fractures in cats

    Microsoft Academic Search

    Harry Scott

    2005-01-01

    LONG bone fractures are common and account for 50 per cent of all feline fractures. They are usually caused by road traffic accidents, but may also result from falls, fights and gunshot wounds. Fractures of the hindquarters predominate, with reports of 73 per cent of fractures involving the hindlimbs, pelvis or sacrum. Although the broad principles of long bone fracture

  13. Fractography: Determining the sites of fracture initiation

    Microsoft Academic Search

    John J. Mecholsky

    1995-01-01

    Fractography is the analysis of fracture surfaces. Here, it refers to quantitative fracture surface analysis (FSA) in the context of applying the principles of fracture mechanics to the topography observed on the fracture surface of brittle materials. The application of FSA is based on the principle that encoded on the fracture surface of brittle materials is the entire history of

  14. Fracture healing: mechanisms and interventions

    PubMed Central

    Einhorn, Thomas A.; Gerstenfeld, Louis C.

    2015-01-01

    Fractures are the most common large-organ, traumatic injuries to humans. The repair of bone fractures is a postnatal regenerative process that recapitulates many of the ontological events of embryonic skeletal development. Although fracture repair usually restores the damaged skeletal organ to its pre-injury cellular composition, structure and biomechanical function, about 10% of fractures will not heal normally. This article reviews the developmental progression of fracture healing at the tissue, cellular and molecular levels. Innate and adaptive immune processes are discussed as a component of the injury response, as are environmental factors, such as the extent of injury to the bone and surrounding tissue, fixation and the contribution of vascular tissues. We also present strategies for fracture treatment that have been tested in animal models and in clinical trials or case series. The biophysical and biological basis of the molecular actions of various therapeutic approaches, including recombinant human bone morphogenetic proteins and parathyroid hormone therapy, are also discussed. PMID:25266456

  15. FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly different from that of gas displacement processes. The work is of experimental nature and clarifies several misconceptions in the literature. Based on experimental results, it is established that the main reason for high efficiency of solution gas drive from heavy oil reservoirs is due to low gas mobility. Chapter III presents the concept of the alteration of porous media wettability from liquid-wetting to intermediate gas-wetting. The idea is novel and has not been introduced in the petroleum literature before. There are significant implications from such as proposal. The most direct application of intermediate gas wetting is wettability alteration around the wellbore. Such an alteration can significantly improve well deliverability in gas condensate reservoirs where gas well deliverability decreases below dewpoint pressure. Part I of Chapter III studies the effect of gravity, viscous forces, interfacial tension, and wettability on the critical condensate saturation and relative permeability of gas condensate systems. A simple phenomenological network model is used for this study, The theoretical results reveal that wettability significantly affects both the critical gas saturation and gas relative permeability. Gas relative permeability may increase ten times as contact angle is altered from 0{sup o} (strongly liquid wet) to 85{sup o} (intermediate gas-wetting). The results from the theoretical study motivated the experimental investigation described in Part II. In Part II we demonstrate that the wettability of porous media can be altered from liquid-wetting to gas-wetting. This part describes our attempt to find appropriate chemicals for wettability alteration of various substrates including rock matrix. Chapter IV provides a comprehensive treatment of molecular, pressure, and thermal diffusion and convection in porous media Basic theoretical analysis is presented using irreversible thermodynamics.

  16. Contaminant transport in fractured porous media: Analytical solution for a single fracture

    Microsoft Academic Search

    D. H. Tang; E. O. Frind; E. A. Sudicky

    1981-01-01

    A general analytical solution is developed for the problem of contaminant transport along a discrete fracture in a porous rock matrix. The solution takes into account advective transport in the fracture, longitudinal mechanical dispersion in the fracture, molecular diffusion in the fracture fluid along the fracture axis, molecular diffusion from the fracture into the matrix, adsorption onto the face of

  17. Fracture analysis of optical fibers

    SciTech Connect

    Mecholsky, J.J.

    1980-01-01

    The fracture markings on glass optical fiber surfaces are quantitatively related to the strength and time under load. Knowledge of the fracture-initiating defects and the surrounding topography pinpoints the source of failure, aids in troubleshooting, and improves production procedures. It is shown that the techniques of fracture surface analysis help analyze in-service failures as well as improve fiber optic production control.

  18. Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models

    E-print Network

    Kim, Tae Hyung

    2009-05-15

    and natural fractures were investigated in this study using an X-Ray CT Scanner. Fractal dimension, D, and amplitude parameter, A, of fracture aperture approaches a constant value with increased sampling area, similar to the behavior of fracture roughness...

  19. Fracture characterization and estimation of fracture porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models 

    E-print Network

    Kim, Tae Hyung

    2009-05-15

    and natural fractures were investigated in this study using an X-Ray CT Scanner. Fractal dimension, D, and amplitude parameter, A, of fracture aperture approaches a constant value with increased sampling area, similar to the behavior of fracture roughness...

  20. Unilateral Versus Bilateral Prostatic Arterial Embolization for Lower Urinary Tract Symptoms in Patients with Prostate Enlargement

    SciTech Connect

    Bilhim, Tiago, E-mail: tiagobilhim@hotmail.com [Universidade Nova de Lisboa (UNL), Departamento Universitario de Anatomia, Faculdade de Ciencias Medicas (FCM) (Portugal)] [Universidade Nova de Lisboa (UNL), Departamento Universitario de Anatomia, Faculdade de Ciencias Medicas (FCM) (Portugal); Pisco, Joao; Rio Tinto, Hugo; Fernandes, Lucia [Interventional Radiology, Saint Louis Hospital (Portugal)] [Interventional Radiology, Saint Louis Hospital (Portugal); Campos Pinheiro, Luis [Universidade Nova de Lisboa (UNL), Departamento Universitario de Urologia, Faculdade de Ciencias Medicas (FCM) (Portugal)] [Universidade Nova de Lisboa (UNL), Departamento Universitario de Urologia, Faculdade de Ciencias Medicas (FCM) (Portugal); Duarte, Marisa; Pereira, Jose A. [Interventional Radiology, Saint Louis Hospital (Portugal)] [Interventional Radiology, Saint Louis Hospital (Portugal); Oliveira, Antonio G. [Universidade Nova de Lisboa (UNL), Biostatistics Department, Faculdade de Ciencias Medicas (FCM) (Portugal)] [Universidade Nova de Lisboa (UNL), Biostatistics Department, Faculdade de Ciencias Medicas (FCM) (Portugal); O'Neill, Joao [Universidade Nova de Lisboa (UNL), Departamento Universitario de Anatomia, Faculdade de Ciencias Medicas (FCM) (Portugal)] [Universidade Nova de Lisboa (UNL), Departamento Universitario de Anatomia, Faculdade de Ciencias Medicas (FCM) (Portugal)

    2013-04-15

    This study was designed to compare baseline data and clinical outcome between patients with prostate enlargement/benign prostatic hyperplasia (PE/BPH) who underwent unilateral and bilateral prostatic arterial embolization (PAE) for the relief of lower urinary tract symptoms (LUTS). This single-center, ambispective cohort study compared 122 consecutive patients (mean age 66.7 years) with unilateral versus bilateral PAE from March 2009 to December 2011. Selective PAE was performed with 100- and 200-{mu}m nonspherical polyvinyl alcohol (PVA) particles by a unilateral femoral approach. Bilateral PAE was performed in 103 (84.4 %) patients (group A). The remaining 19 (15.6 %) patients underwent unilateral PAE (group B). Mean follow-up time was 6.7 months in group A and 7.3 months in group B. Mean prostate volume, PSA, International prostate symptom score/quality of life (IPSS/QoL) and post-void residual volume (PVR) reduction, and peak flow rate (Qmax) improvement were 19.4 mL, 1.68 ng/mL, 11.8/2.0 points, 32.9 mL, and 3.9 mL/s in group A and 11.5 mL, 1.98 ng/mL, 8.9/1.4 points, 53.8 mL, and 4.58 mL/s in group B. Poor clinical outcome was observed in 24.3 % of patients from group A and 47.4 % from group B (p = 0.04). PAE is a safe and effective technique that can induce 48 % improvement in the IPSS score and a prostate volume reduction of 19 %, with good clinical outcome in up to 75 % of treated patients. Bilateral PAE seems to lead to better clinical results; however, up to 50 % of patients after unilateral PAE may have a good clinical outcome.

  1. Unilateral Prostate Cancer Cannot be Accurately Predicted in Low-Risk Patients

    SciTech Connect

    Isbarn, Hendrik, E-mail: hendrikisbarn@gmail.co [Martiniclinic, Prostate Cancer Center Hamburg-Eppendorf, Hamburg (Germany); University Hospital Hamburg-Eppendorf, Department of Urology, Hamburg (Germany); Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Quebec (Canada); Karakiewicz, Pierre I. [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Quebec (Canada); Vogel, Susanne [University Hospital Hamburg-Eppendorf, Department of Urology, Hamburg (Germany)

    2010-07-01

    Purpose: Hemiablative therapy (HAT) is increasing in popularity for treatment of patients with low-risk prostate cancer (PCa). The validity of this therapeutic modality, which exclusively treats PCa within a single prostate lobe, rests on accurate staging. We tested the accuracy of unilaterally unremarkable biopsy findings in cases of low-risk PCa patients who are potential candidates for HAT. Methods and Materials: The study population consisted of 243 men with clinical stage {<=}T2a, a prostate-specific antigen (PSA) concentration of <10 ng/ml, a biopsy-proven Gleason sum of {<=}6, and a maximum of 2 ipsilateral positive biopsy results out of 10 or more cores. All men underwent a radical prostatectomy, and pathology stage was used as the gold standard. Univariable and multivariable logistic regression models were tested for significant predictors of unilateral, organ-confined PCa. These predictors consisted of PSA, %fPSA (defined as the quotient of free [uncomplexed] PSA divided by the total PSA), clinical stage (T2a vs. T1c), gland volume, and number of positive biopsy cores (2 vs. 1). Results: Despite unilateral stage at biopsy, bilateral or even non-organ-confined PCa was reported in 64% of all patients. In multivariable analyses, no variable could clearly and independently predict the presence of unilateral PCa. This was reflected in an overall accuracy of 58% (95% confidence interval, 50.6-65.8%). Conclusions: Two-thirds of patients with unilateral low-risk PCa, confirmed by clinical stage and biopsy findings, have bilateral or non-organ-confined PCa at radical prostatectomy. This alarming finding questions the safety and validity of HAT.

  2. Coupled Fracture and Flow in Shale in Hydraulic Fracturing

    NASA Astrophysics Data System (ADS)

    Carey, J. W.; Mori, H.; Viswanathan, H.

    2014-12-01

    Production of hydrocarbon from shale requires creation and maintenance of fracture permeability in an otherwise impermeable shale matrix. In this study, we use a combination of triaxial coreflood experiments and x-ray tomography characterization to investigate the fracture-permeability behavior of Utica shale at in situ reservoir conditions (25-50 oC and 35-120 bars). Initially impermeable shale core was placed between flat anvils (compression) or between split anvils (pure shear) and loaded until failure in the triaxial device. Permeability was monitored continuously during this process. Significant deformation (>1%) was required to generate a transmissive fracture system. Permeability generally peaked at the point of a distinct failure event and then dropped by a factor of 2-6 when the system returned to hydrostatic failure. Permeability was very small in compression experiments (< 1 mD), possibly because of limited fracture connectivity through the anvils. In pure share experiments, shale with bedding planes perpendicular to shear loading developed complex fracture networks with narrow apertures and peak permeability of 30 mD. Shale with bedding planes parallel to shear loading developed simple fractures with large apertures and a peak permeability as high as 1 D. Fracture systems held at static conditions for periods of several hours showed little change in effective permeability at hydrostatic conditions as high as 140 bars. However, permeability of fractured systems was a function of hydrostatic pressure, declining in a pseudo-linear, exponential fashion as pressure increased. We also observed that permeability decreased with increasing fluid flow rate indicating that flow did not follow Darcy's Law, possibly due to non-laminar flow conditions, and conformed to Forscheimer's law. The coupled deformation and flow behavior of Utica shale, particularly the large deformation required to initiate flow, indicates the probable importance of activation of existing fractures in hydraulic fracturing and that these fractures can have adequate permeability for the production of hydrocarbon.

  3. Boxer's fracture: management and outcomes.

    PubMed

    Eldridge, Julie; Apau, Daniel

    2015-07-10

    Boxer's fractures are common hand injuries, but their management varies greatly. Two years ago, a boxer's fracture care pathway was developed for use in the Royal London Hospital emergency department to standardise management. This article describes a clinical service evaluation carried out to test the validity of the pathway. The evaluation examined the functional outcomes of patients with boxer's fractures with 50° or less palmar angulation who were discharged with no follow up. Findings show that most returned to work immediately and had good functional outcomes, which suggests that the pathway is safe for uncomplicated fractures with 50° or less palmar angulation. PMID:26159346

  4. Management of femoral shaft fractures.

    PubMed

    Neumann, M V; Südkamp, N P; Strohm, P C

    2015-01-01

    Femoral shaft fractures are severe injuries and are often associated with a high impact trauma mechanism, frequently seen in multiple injured patients. In contrast an indirect trauma mechanism can lead to a complex femoral shaft fracture especially in elderly patients with minor bone stock quality. Hence management of femoral shaft fractures is often directed by co-morbidities, additional injuries and the medical condition of the patient. Timing of fracture stabilization is depended on the overall medical condition of the patient, but definite fracture fixation can often be implemented in the early total care concept in management of multiple injured patients. The treatment of choice is intramedullary fracture fixation. Further development of existing intramedullary nailing systems now offer comfortable handling and different locking options. Ipsilateral fractures of the neck and shaft are therefore facilitated in management. Then again increasing numbers of obese patient are representing a new patient group with challenging co-factors in fracture management. Sufficient preoperative planning is helpful to choose the most adequate fixation device. Correct reduction of the fracture and perioperative control of the axis and rotation is mandatory to avoid postoperative malrotation, which still represents the most frequent complication. PMID:25748658

  5. Perioperative Risk Assessment in Patients Aged 75 Years or Older: Comparison between Bilateral and Unilateral Total Knee Arthroplasty

    PubMed Central

    Choi, Young-Joon; Ra, Ho Jong; Hwang, Do-Yon; Kim, Tae-Kyung; Shim, Sang-Jun

    2014-01-01

    Purpose The purpose of this study is to evaluate the risk of sequential bilateral total knee arthroplasty (TKA) under 1 anesthesia in patients 75 years or older. Materials and Methods Patients aged 75 years or older who underwent sequential bilateral TKA (bilateral group, n=159) and unilateral TKA (unilateral group, n=159) between 2002 and 2012 were selected. All patients were evaluated for underlying medical diseases, such as cardiac, pulmonary, and renal problems, and high-risk patients were recommended to postpone the surgery. We compared the underlying diseases, major postoperative complications, and the length of hospital stay between bilateral and unilateral groups. Results The prevalence of underlying diseases of the bilateral group was 74.8% and major complications occurred in 6 patients (3.8%). The prevalence of underlying diseases of the unilateral group was 52.4% and complications were observed in 4 patients (2.4%). Although the complication rate of the bilateral group was slightly higher than that of the unilateral group, the difference was not statistically meaningful (p=0.204). The length of hospital stay was 21.9 days for the bilateral group and 24.9 days for the unilateral group. Conclusions There was no significant difference in postoperative complications between groups. The result shows that bilateral TKA can be relatively safe compared with unilateral TKA in patients 75 years or older. However, careful selection of low-risk patients is advised. PMID:25505704

  6. Fracture compliance estimation using borehole tube waves

    E-print Network

    Bakku, Sudhish Kumar

    We tested two models, one for tube-wave generation and the other for tube-wave attenuation at a fracture intersecting a borehole that can be used to estimate fracture compliance, fracture aperture, and lateral extent. In ...

  7. Hydraulic Fracturing in Michigan Integrated Assessment

    E-print Network

    Kamat, Vineet R.

    Hydraulic Fracturing in Michigan Integrated Assessment #12;Agenda · Welcome and introduction and timeline · Panel presentation and discussion · Facilitated Q & A · Closing remarks #12;Hydraulic Fracturing · Leverages resources IA BENEFITS Benefits of Integrated Assessment #12;Key Points: · Hydraulic Fracturing (HF

  8. Investigation of Created Fracture Geometry through Hydraulic Fracture Treatment Analysis 

    E-print Network

    Ahmed, Ibraheem 1987-

    2012-11-30

    fracture geometry illustrates that it is not possible to reach the full fracture geometry implied by microseismic given the finite amount of fluid and proppant that was pumped. The model does show however that the created geometry appears to be much larger...

  9. Fracture\\/matrix interaction in a fracture of finite extent

    Microsoft Academic Search

    Jerry P. Fairley

    2010-01-01

    The behavior of a wetting front invading a fracture in an unsaturated, porous matrix is of some importance for understanding infiltration and recharge processes, contaminant transport, and similar topics. Previous investigators have examined this problem, and a number of models have been published in the literature. It is, however, difficult to observe processes inside a fracture, particularly in a field

  10. Leakage losses from a hydraulic fracture and fracture propagation

    Microsoft Academic Search

    Robert E. Johnson; Craig W. Gustafson

    1988-01-01

    The fluid mechanics of viscous fluid injection into a fracture embedded in a permeable rock formation is studied. Coupling between flow in the fracture and flow in the rock is retained. The analysis is based on a perturbation scheme that assumes the depth of penetration of the fluid into the rock is small compared to the characteristic length w30\\/k, where

  11. Leakage losses from a hydraulic fracture and fracture propagation

    Microsoft Academic Search

    Robert E. Johnson; Craig W. Gustafson

    1988-01-01

    The fluid mechanics of viscous fluid injection into a fracture embedded in a permeable rock formation is studied. Coupling between flow in the fracture and flow in the rock is retained. The analysis is based on a perturbation scheme that assumes the depth of penetration of the fluid into the rock is small compared to the characteristic length w³â\\/k, where

  12. Permeability damage to natural fractures caused by fracturing fluid polymers

    SciTech Connect

    Gall, B.L.; Sattler, A.R.; Maloney, D.R.; Raible, C.J.

    1988-04-01

    Formation damage studies using artificially fractured, low-permeability sandstone cores indicate that viscosified fracturing fluids can severely restrict gas flow through these types of narrow fractures. These studies were performed in support of the Department of Energy's Multiwell Experiment (MWX). Extensive geological and production evaluations at the MWX site indicate that the presence of a natural fracture system is largely responsible for unstimulated gas production. The laboratory formation damage studies were designed to examine changes in cracked core permeability to gas caused by fracturing fluid residues introduced into such narrow fractures during fluid leakoff. Polysaccharide polymers caused significant reduction (up to 95%) to gas flow through cracked cores. Polymer fracturing fluid gels used in this study included hydroxypropyl guar, hydroxyethyl cellulose, and xanthan gum. In contrast, polyacrylamide gels caused little or no reduction in gas flow through cracked cores after liquid cleanup. Other components of fracturing fluids (surfactants, breakers, etc.) caused less damage to gas flows. Other factors affecting gas flow through cracked cores were investigated, including the effects of net confining stress and non-Darcy flow parameters. Results are related to some of the problems observed during the stimulation program conducted for the MWX. 24 refs., 4 figs., 7 tabs.

  13. Numerical Investigation of Interaction Between Hydraulic Fractures and Natural Fractures 

    E-print Network

    Xue, Wenxu

    2011-02-22

    .3) where 2 2 2 2 1( , ) [ (arctan arctan ) 4 (1 ) ( ) ( ) ( ) ( ) ] y yf x y y x a x a x a In x a y x a In x a y pi ?= ? ? ?? ? + ? ? + + + + + ....................................... (2.4) Knowing the analytical solution... of Hydraulic Fractures and Natural Fractures ................................ 7 1.4 Research Objectives ..................................................................................... 12 1.5 Sign Convention...

  14. Effect of unilateral, bilateral, and combined plyometric training on explosive and endurance performance of young soccer players.

    PubMed

    Ramírez-Campillo, Rodrigo; Burgos, Carlos H; Henríquez-Olguín, Carlos; Andrade, David C; Martínez, Cristian; Álvarez, Cristian; Castro-Sepúlveda, Mauricio; Marques, Mário C; Izquierdo, Mikel

    2015-05-01

    Ramírez-Campillo, R, Burgos, CH, Henríquez-Olguín, C, Andrade, DC, Martínez, C, Álvarez, C, Castro-Sepúlveda, M, Marques, MC, and Izquierdo, M. Effect of unilateral, bilateral, and combined plyometric training on explosive and endurance performance of young soccer players. J Strength Cond Res 29(5): 1317-1328, 2015-The aim of the study was to compare the effects of bilateral, unilateral, or combined bilateral and unilateral plyometric training (PT) on muscle power output, endurance, and balance performance adaptations in young soccer players. Four groups of young soccer players (age 11.4 ± 2.2 years) were divided into control group (CG; n = 14), bilateral group (BG; n = 12), unilateral group (UG; n = 16), and bilateral + unilateral group (B + UG; n = 12). Players were measured in unilateral and bilateral countermovement jump with arms, 5 multiple bounds test, 20-cm drop jump reactive strength index, maximal kicking velocity, sprint and agility test time, endurance, and balance performance. The PT was applied during 6 weeks, 2 sessions per week, for a total of 2,160 jumps. After intervention, all PT groups showed a statistically significant (p ? 0.05) change in all performance measures, with no statistically significant differences between treatments. Among the 21 performance measures, the B + UG showed a significantly (p ? 0.05) higher performance change in 13 of them vs. the CG, whereas the UG and BG showed only 6 and 3, respectively. The current study showed that bilateral, unilateral, and combined bilateral and unilateral PT ensured significant improvement in several muscular power and endurance performance measures in young soccer players. However, the combination of unilateral and bilateral drills seems more advantageous to induce superior performance improvements. PMID:25474338

  15. Femoral neck stress fracture.

    PubMed

    Konetsky, Michael; Miller, Joseph; Tripp, Courtney

    2013-04-01

    The patient was a 19-year-old woman who recently completed a military basic training program. She was evaluated by a physical therapist in a direct-access capacity for a chief complaint of anterior right hip pain that limited her ability to run. Due to the limited sensitivity of radiographs, magnetic resonance imaging of the right hip was obtained, which revealed a stress fracture of the right distal femoral neck.J Orthop Sports Phys Ther 2013;43(4):275. doi:10.2519/jospt.2013.0407. PMID:23542438

  16. Fatigue and fracture: Overview

    NASA Technical Reports Server (NTRS)

    Halford, G. R.

    1984-01-01

    A brief overview of the status of the fatigue and fracture programs is given. The programs involve the development of appropriate analytic material behavior models for cyclic stress-strain-temperature-time/cyclic crack initiation, and cyclic crack propagation. The underlying thrust of these programs is the development and verification of workable engineering methods for the calculation, in advance of service, of the local cyclic stress-strain response at the critical life governing location in hot section compounds, and the resultant crack initiation and crack growth lifetimes.

  17. Laboratory Simulations of Hydraulic Fracturing

    Microsoft Academic Search

    J. M. Papadopoulos; V. M. Narendran; M. P. Cleary

    1983-01-01

    Two novel distinctly different laboratory apparatus have been developed to allow controlled, precise, repeatable and observable experimental simulations of hydraulic fracturing over a broad range of well-determined dominant parameters and practical geometries. One system avoids specimen preparation (by using predetermined interface separation), while the other most efficiently employs castable blocks with proper scaling of fracture toughness to correctly capture crack

  18. Electrothermal fracturing of tensile specimens

    NASA Technical Reports Server (NTRS)

    Blinn, H. O.; Hanks, J. G.; Perkins, H. P.

    1970-01-01

    Pulling device consisting of structural tube, connecting rod, spring-loaded nuts, loading rod, heating element, and three bulkheads fractures tensile specimens. Alternate heating and cooling increases tensile loading by increments until fracturing occurs. Load cell or strain gage, applied to pulling rod, determines forces applied.

  19. [Fractures of the distal radius].

    PubMed

    Rueger, J M; Hartel, M J; Ruecker, A H; Hoffmann, M

    2014-11-01

    The most prevalent fractures managed by trauma surgeons are those involving the distal radius. The injury occurs in two peaks of prevalence: the first peak around the age of 10 years and the second peak around the age of 60 years. Distal radius fracture management requires sensitive diagnostics and classification. The objectives of treatment are the reconstruction of a pain-free unlimited durable functioning of the wrist and avoidance of typical fracture complications. Non-operative conservative management is generally employed for stable non-displaced fractures of the distal radius with the expectation of a good functional outcome. Unstable comminuted fractures with intra-articular and extra-articular fragment zones are initially set in a closed operation and finally by osteosynthesis. An armament of surgical implants is available for instable fractures requiring fixation. Palmar locked plate osteosynthesis has been established in recent years as the gold standard for operative management of distal radius fractures. Complex Working Group on Osteosynthesis (AO) classification type 3 fractures require extensive preoperative diagnostics to identify and treat typical associated injuries around the wrist. PMID:25398510

  20. Toward automated bone fracture classification

    NASA Astrophysics Data System (ADS)

    Funk, Michael W.; El-Kwae, Essam A.; Kellam, James F.

    2001-07-01

    A model is developed for the automated classification of bone fractures via image analysis techniques. The model is based on the widely used fracture classification system developed by the M.E. Mueller Foundation of Bern, Switzerland. The system describes a hierarchy of fractures, six layers deep. It also describes a series of questions to be asked about a given fracture, in which each question answered classifies the fracture into more descriptive subcategories. The model developed considers fracture classification as a tree traversal problem, in which the lower layers of the tree represent more precise categorizations. At each of the tree's nodes, algorithms specific to that subcategory determine which of the child nodes will be visited. Digital image processing techniques are most readily applicable to the largest number of nodes. Thus, the initial algorithms in this work are based on image processing techniques. The main contributions of this paper include a model for automated bone fracture classification and the algorithms for classification of a subset of long bone fractures. This work aims to provide a solid model and initial results that will serve as the basis for further research into this challenging and potentially rewarding field.

  1. The Relationship Between Maximum Unilateral Squat Strength and Balance in Young Adult Men and Women

    PubMed Central

    McCurdy, Kevin; Langford, George

    2006-01-01

    The purpose of this study was to determine the relationship between unilateral squat strength and measures of static balance to compare balance performance between the dominant and non-dominant leg. Seventeen apparently healthy men (mean mass 90.5 ± 20.9 kg and age 21.7 ± 1.8 yrs) and 25 women (mean mass 62.2 ± 14.5 kg and age 21.9 ± 1.3 yrs) completed the study. Weight bearing unilateral strength was measured with a 1RM modified unilateral squat on the dominant and non-dominant leg. The students completed the stork stand and wobble board tests to determine static balance on the dominant and non-dominant leg. Maximum time maintained in the stork stand position, on the ball of the foot with the uninvolved foot against the involved knee with hands on the hips, was recorded. Balance was measured with a 15 second wobble board test. No significant correlations were found between the measurements of unilateral balance and strength (r values ranged between -0.05 to 0.2) for the men and women. Time off balance was not significantly different between the subjects’ dominant (men 1.1 ± 0.4 s; women 0.3 ± 0.1 s) and non-dominant (men 0.9 ± 0.3 s; women 0.3 ± 0.1 s) leg for the wobble board. Similar results were found for the time balanced during the stork stand test on the dominant (men 26.4 ± 6.3 s; women 24.1 ± 5.6 s) and non-dominant (men 26.0 ± 5.7 s; women 21.3 ± 4.1 s) leg. The data indicate that static balance and strength is unrelated in young adult men and women and gains made in one variable after training may not be associated with a change in performance of the other variable. These results also suggest that differences in static balance performance between legs can not be determined by leg dominance. Similar research is needed to compare contralateral leg balance in populations who participate in work or sport activities requiring repetitive asymmetrical use. A better understanding of contralateral balance performance will help practitioners make evaluative decisions during the rehabilitation process. Key Points 1RM unilateral squat strength is unrelated to measures of unilateral static balance in young adult men and women Static balance is similar between the dominant and non-dominant leg in young adult men and women Side-to-side differences in balance warrant assessment and training to correct imbalances prior to participation in activities that present a high risk for injury. PMID:24260001

  2. Fracture detection and mapping

    SciTech Connect

    Goldstein, N.E.; Iovenitti, J.L.

    1986-03-01

    Because the costs of drilling, completing, and testing a well can be extremely high, it is important to develop better tools and methods for locating high permeability zones prior to drilling, and to develop better tools and methods for identifying and characterizing major fracture zones during the drilling and well testing stages. At the recommendation of the LBL Industry Review Panel on Geothermal Reservoir Technology, we organized and convened a one-day workshop this past July to discuss various aspects of DOE's current and planned activities in fracture detection, to review the geothermal industry's near-term and long-term research needs, to determine the priority of those needs, to disseminate to industry the status of research in progress, and to discuss the possibility of future joint research between industry and DOE. In this paper we present a brief overview of the workshop from the perspective of those who participated in it and provided us with written comments to a questionnaire that was distributed.

  3. Osteoporosis, Fractures, and Diabetes

    PubMed Central

    2014-01-01

    It is well established that osteoporosis and diabetes are prevalent diseases with significant associated morbidity and mortality. Patients with diabetes mellitus have an increased risk of bone fractures. In type 1 diabetes, the risk is increased by ?6 times and is due to low bone mass. Despite increased bone mineral density (BMD), in patients with type 2 diabetes the risk is increased (which is about twice the risk in the general population) due to the inferior quality of bone. Bone fragility in type 2 diabetes, which is not reflected by bone mineral density, depends on bone quality deterioration rather than bone mass reduction. Thus, surrogate markers and examination methods are needed to replace the insensitivity of BMD in assessing fracture risks of T2DM patients. One of these methods can be trabecular bone score. The aim of the paper is to present the present state of scientific knowledge about the osteoporosis risk in diabetic patient. The review also discusses the possibility of problematic using the study conclusions in real clinical practice. PMID:25050121

  4. Fracture technology for brittle materials

    NASA Technical Reports Server (NTRS)

    Salem, Jonathan A.

    1988-01-01

    Ceramics materials have the potential for use in high-temperature, fuel-efficient engines. However, because these materials are brittle, their fracture characteristics must be well documented prior to their application. Thus Lewis is working to understand the fracture and strength properties of brittle ceramic and ceramic matrix materials. An understanding of fracture properties aids both designers who are attempting to design high-temperature structures and materials scientists who seek to design more temperature-resistant materials. Both analytical and experimental approaches to fracture analysis are being taken. Methods for testing fracture toughness, crack growth resistance, and strength are being developed. The failure mechanisms at both room and elevated temperatures are also being investigated. Such investigations aid materials scientists in developing better high-temperature materials. Of concern is the anisotropy of ceramic materials and the experimental verification of ceramic design codes that will allow brittle material behavior to be accurately predicted at high temperature.

  5. Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial

    PubMed Central

    2011-01-01

    Background The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%), non-union (5-21%) and early osteo-arthritis (up to 32%) which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences. Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid. Methods/Design This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning). Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory. Study parameters are clinical consolidation, radiological consolidation evaluated by CT-scanning, functional status of the wrist, including assessment by means of the patient rated wrist evaluation (PRWE) questionnaire and quality of life using SF-36 health survey questionnaire. Primary endpoint is number of scaphoid unions at six weeks, secondary endpoints are time interval to clinical and radiological consolidation, number of non-unions, functional status at 52 weeks and non-adherence to the treatment protocol. Trial registration Netherlands Trial Register (NTR): NTR2064 PMID:21548951

  6. A Rare Entity: Bilateral First Rib Fractures Accompanying Bilateral Scapular Fractures

    PubMed Central

    Gulbahar, Gultekin; Kaplan, Tevfik; Turker, Hasan Bozkurt; Gundogdu, Ahmet Gokhan; Han, Serdar

    2015-01-01

    First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare entity. PMID:26175916

  7. Fractures in childhood in Khartoum.

    PubMed

    Doumi, B A; Ahmed, M E; Hassan, R; Elnour, S H; Kashan, A

    1994-06-01

    A prospective study of fractures in 231 children received at Khartoum North Teaching Hospital(KNTH) was carried out for a period of six months. The incidence of child fracture rated as one per day, then it increased from the age of 5 years onwards in boys and between 6 and 8 years in girls. Most injuries were sustained during the day time, especially between late afternoon and sunset. 82% of injured children presented to a medical facility, while 18% were taken to native healers first. Non-road traffic accidents accounted for 84% of the fractures mainly due to sports, domestic injuries and falls; whereas road traffic accidents were 16% and occurred mainly in pedestrians. Forty three percent of the fractures needed only first aid and splintage while 42% needed closed reduction. Thirty one percent of all patients were treated as inpatients. The long bones were affected in 91% of all fractures, the commonest site being the distal end of the forearm (26%), followed by supracondylar fracture of the humerus (15.6%). In the upper limb, left-sided fractures predominated. The epiphyseal injuries were 3.5% of all fractures, mainly at the distal radial epiphysis. Boys were commonly affected between 13-15 years of age. Open fractures constituted 9.8% of the series and were mainly due to traffic accidents in town dwellers, the most vulnerable bones were those of the leg and foot. Pathological fractures accounted for 2.2% and were due to bone cysts and osteogenesis imperfecta. The problem of child safety and the preventive measures need to be more stressed. PMID:7835253

  8. Simultaneous bilateral elbow dislocation with bilateral medial epicondyle fractures in a 13-year-old female gymnast with hyperlaxity.

    PubMed

    Bauer, Stefan; Dunne, Ben; Whitewood, Colin

    2012-01-01

    Bilateral simultaneous elbow dislocations are extremely rare and have only been described in 12 cases. In the paediatric population unilateral elbow dislocations are rare with 3-6% of all elbow injuries and there are only few studies describing this injury exclusively in children. There is only one case report of a paediatric patient who sustained a simultaneous bilateral elbow dislocation with medial epicondyle fractures. We present a second paediatric case of simultaneous bilateral elbow dislocation with associated displaced bilateral medial epicondyle fractures in a gymnast with joint hyperlaxity (3 of 5 Wynne-Davies criteria) treated with closed reduction and short-term immobilisation (3 weeks). The patient returned to full trampoline gymnastics between 4 and 5 months postinjury and made an uneventful recovery. PMID:23234820

  9. SURGERY VERSUS OBSERVATION FOR MANAGING OBSTRUCTIVE GRADE 3 TO 4 UNILATERAL HYDRONEPHROSIS: A REPORT FROM THE SOCIETY FOR FETAL UROLOGY

    Microsoft Academic Search

    Max Maizels; Patrick C. Cartwright; Sandra K. Fernbach; James J. Conway

    1998-01-01

    PurposeThe Society for Fetal Urology has undertaken the first multicenter prospective randomized study of high grade obstructive unilateral hydronephrosis to evaluate the natural history of untreated obstruction and compare it to the benefits of pyeloplasty.

  10. The Impact of Unilateral or Bilateral Cataract Surgery on Visual Acuity and Life Quality of Elderly Patients

    PubMed Central

    Zuo, Lei; Zou, Haidong; Fei, Xinfeng; Xu, Weiqi; Zhang, Jianhong

    2015-01-01

    In the current study, the CLVQOL was used to assess VRQOL before unilateral or bilateral cataract surgery and at the end of the follow-up period in order to determine the greater beneficial mode of surgery for patients, if one of the two surgical methods is more beneficial over the other. The patients were classified as receiving unilateral (group A) and bilateral cataract surgery (group B). There were no significant differences between groups A and B before the operation in terms of life quality scores, binocular weighted average LogMAR BCVA, age, educational level, gender, systematic and ocular comorbidities, and the complications of the operation. It was shown that visual acuity improved more significantly with bilateral cataract surgery than with unilateral surgery in elderly patients with a high preoperative disease burden in Shanghai city. However, the improvement in life quality was not different in patients receiving either bilateral or unilateral cataract surgery. PMID:25874115

  11. Subjective visual horizontal and stabilometer findings in patients with unilateral severe vestibular dysfunction.

    PubMed

    Takai, Yoshinari; Iwasaki, Shinichi; Murofushi, Toshihisa

    2005-01-01

    The records of both stabilometer and subjective visual horizontal (SVH) testing can be used to evaluate vestibular compensation. When results of SVH testing have a strong significant correlation to those of stabilometer testing, clinicians can omit one of two tests from the test battery. To investigate the correlation, results of these two tests of patients with unilateral severe vestibular dysfunction were studied. Twenty-eight patients, 20 men and 8 women, with unilateral severe vestibular dysfunction were enrolled in this study. The correlation between these two tests was considered not significant according to the results. In conclusion, we cannot omit either stabilometer testing or SVH testing for the evaluation of patients with vestibular dysfunction. PMID:16327274

  12. A 12-year-old boy presenting with unilateral proximal interphalangeal joint swelling.

    PubMed

    Small, S; Murthy, V; Sridhar, A V

    2011-01-01

    Pachydermodactyly is a rare and benign superficial dermal fibromatosis, characterised by asymptomatic soft tissue hypertrophy of the lateral and dorsal aspects of the proximal interphalangeal joints. The majority affected are males, with only a few reported female cases, and usually begins to develop around the age of puberty. Pachydermodactyly affects the second, middle and ring fingers of the hand symmetrically and bilaterally. The majority of reported cases demonstrate bilateral involvement of joints, only a small proportion report unilateral involvement. In this case report the authors review literature and discuss a case of pachydermodactyly presenting a unilateral swelling of the proximal interphalangeal joints of only the left hand in a right-handed young male. PMID:22700997

  13. Unilateral NMR investigation of multifunctional treatments on stones based on colloidal inorganic and organic nanoparticles.

    PubMed

    Di Tullio, Valeria; Cocca, Mariacristina; Avolio, Roberto; Gentile, Gennaro; Proietti, Noemi; Ragni, Pietro; Errico, Maria Emanuela; Capitani, Donatella; Avella, Maurizio

    2015-01-01

    Consolidation and protection are among the most important treatments usually carried out in conservation of stone artifacts and monuments. In this paper, portable unilateral NMR and conventional techniques were used for investigating new multifunctional treatments based on tetraethoxysilane, silica, and polytetrafluoroethylene nanoparticles. The study was carried out on a very complex and heterogeneous porous stone such as tuff. NMR study allowed to obtain detailed information on the penetration depth of treatments, the hydrophobic effect, and changes in the open porosity caused by treatments. Physical and chemical inhomogeneities between the impregnated layers of tuff and the layers underneath were also detected. The average pores radius and pores interconnection obtained from NMR diffusion measurements were used for the first time to compare effects of different consolidating and/or protective treatments on stone. Because unilateral NMR technique is neither destructive nor invasive, investigation of treatments can be also carried out and optimized directly on buildings and monuments of interest for Cultural Heritage. PMID:25178927

  14. Brain damage and IQ in unilateral Sturge-Weber Syndrome: Support for a “fresh start” hypothesis

    PubMed Central

    Behen, Michael E; Juhász, Csaba; Wolfe-Christensen, Cortney; Guy, William; Halverson, Stacey; Rothermel, Robert; Janisse, James; Chugani, Harry T

    2011-01-01

    We tested the hypothesis that extent of severe hypometabolism measured by glucose PET has a U-shaped (non-linear) relationship to IQ in children with unilateral Sturge-Weber Syndrome. Thirty-five consecutive children (age range, 30 to 153 months) with SWS and unilateral brain involvement were enrolled in the study. Participants underwent cognitive assessment and interictal glucose PET scans. Regression analyses tested whether a quadratic model best accounted for the relationship between extent of severe cortical hypometabolism and IQ, controlling for seizure variables. A significant quadratic relationship was found between IQ and extent of severe (but not total) hypometabolism. Seizure variables also contributed significant variance to cognitive functions. Results suggest that intermediate size of severe hemispheric hypometabolism is associated with the worst, small or absent lesions the best, cognitive outcomes. Children with very large extent of the hemisphere severely affected are likely to have relatively preserved cognitive function. PMID:21852199

  15. Emergent Unilateral Renal Artery Stenting for Treatment of Flash Pulmonary Edema: Fact or Fiction?

    PubMed Central

    Khan, Asaad Akbar; McFadden, Eugene Patrick

    2015-01-01

    Flash pulmonary edema is characteristically sudden in onset with rapid resolution once appropriate therapy has been instituted (Messerli et al., 2011). Acute increase of left ventricular (LV) end diastolic pressure is the usual cause of sudden decompensated cardiac failure in this patient population. Presence of bilateral renal artery stenosis or unilateral stenosis in combination with a single functional kidney in the susceptible cohort is usually blamed for this condition. We describe a patient who presented with flash pulmonary edema in the setting of normal coronary arteries. Our case is distinct as our patient developed flash pulmonary edema secondary to unilateral renal artery stenosis in the presence of bilateral functioning kidneys. Percutaneous stent implantation in the affected renal artery resulted in rapid resolution of pulmonary edema. PMID:25793128

  16. Direct and indirect effects of unilateral divorce law on marital stability.

    PubMed

    Kneip, Thorsten; Bauer, Gerrit; Reinhold, Steffen

    2014-12-01

    Previous research examining the impact of unilateral divorce law (UDL) on the prevalence of divorce has provided mixed results. Studies based on cross-sectional cross-country/cross-state survey data have received criticism for disregarding unobserved heterogeneity across countries, as have studies using country-level panel data for failing to account for possible mediating mechanisms at the micro level. We seek to overcome both shortcomings by using individual-level event-history data from 11 European countries (SHARELIFE) and controlling for unobserved heterogeneity over countries and cohorts. We find that UDL in total increased the incidence of marital breakdown by about 20 %. This finding, however, neglects potential selection effects into marriage. Accordingly, the estimated effect of unilateral divorce laws becomes much larger when we control for age at marriage, which is used as indicator for match quality. Moreover, we find that UDL particularly affects marital stability in the presence of children. PMID:25354572

  17. Unilateral nevoid hyperkeratosis of the nipple: a report of two cases.

    PubMed

    Shastry, Veeranna; Betkerur, Jayadev; Kushalappa, P A

    2006-01-01

    Nevoid hyperkeratosis of the nipple and areola is an unusual condition. Two female patients aged 31 and 18 years presented with chronic unilateral warty lesions of the nipple. One patient had difficulty in breastfeeding from the affected side. A skin biopsy showed acanthosis, hyperkeratosis, papillomatosis and lymphocytic infiltrate in the dermis. There was no significant improvement with topical tretinoin cream in both the patients. PMID:16880580

  18. Reduction of gastrointestinal motility by unilateral thyroparathyroidectomy plus subdiaphragmatic vagotomy in rats

    PubMed Central

    Lee, Jun Ho; Kwon, Oh Deog; Ahn, Seon Ho; Choi, Keun Han; Park, Ji Hye; Lee, Seoul; Choi, Bong Kyu; Jung, Kyu Yong

    2012-01-01

    AIM: To investigate whether the combined methods of unilateral thyroparathyroidectomy (TPX) and subdiaphragmatic vagotomy (VAX) can be adapted for rats and used as a reliable method to produce a rat model of long-term reduction of gastrointestinal (GI) motor function. METHODS: Male Sprague-Dawley rats were randomly divided into 3 groups, normal, sham-operated and unilateral TPX plus VAX. The TPX plus VAX rats received VAX 7 d after application of TPX, and dietary intake and fecal output were then measured daily for 1 wk. After completion of the experiments, gastric emptying and small bowel transit were measured in vivo, and the contractile responses of colonic strips to excitatory and inhibitory neurotransmitters were estimated using isometric force transducers in vitro. RESULTS: In comparison with normal and sham-operated rats, rats which received unilateral TPX plus VAX showed a significant decrease in body weight and in fecal pellet number and weight throughout the entire week. Application of TPX plus VAX to rats markedly delayed gastric emptying and small bowel transit. In TPX plus VAX rats, the longitudinal muscles of the proximal colon showed a significant reduction in contractile responses to acetylcholine (5 × 10-6 mol/L), and a dramatic attenuation of contractile responses was also observed in both the longitudinal and circular muscles of the distal colon. However, the spontaneous contractility of the colonic strips from TPX plus VAX rats was not significantly affected by treatment with N-nitro-L-arginine-methyl ester (0.1 mol/L). CONCLUSION: The results indicate that unilateral TPX plus VAX reduced the motor function of the GI tract in rats, and the reduced gut motility is likely mediated, at least in part, by inhibition of the excitatory neurotransmitter system. PMID:22969231

  19. Acute management of a unilateral incarcerated spigelian hernia in a patient with bilateral spigelian hernias

    PubMed Central

    Monkhouse, SJW

    2013-01-01

    Spigelian hernias were first described by Joseph Klinkosch in the 18th century, and have since posed a diagnostic and surgical problem owing to their non-specific presentation and rarity. While the management of unilateral hernias is fairly well described in today’s literature, bilateral Spigelian hernias are very rare. We describe the emergency management of a patient with bilateral Spigelian hernias, diagnosed on computed tomography. PMID:24025275

  20. Altered phospholipid profile in urine of rats with unilateral ureteral obstruction

    Microsoft Academic Search

    Yasuko Yoshioka; Toshihiko Tsutsumi; Mika Adachi; Akira Tokumura

    2009-01-01

    Little is known about renal damage to the contralateral kidney after unilateral ureteral obstruction (UUO). Using liquid chromatography-time\\u000a of flight-mass spectrometry combined with principal component analysis (PCA), we compared urinary phospholipid profiles before\\u000a and two weeks after UUO in rats. PCA revealed that negative ions corresponding to three molecular species of phosphatidylethanolamine\\u000a (PE) and two species of phosphatidylglycerol (PG) had

  1. Acting alone: U.S. unilateral uses of force, military revolutions, and hegemonic stability theory

    E-print Network

    Podliska, Bradley Florian

    2009-06-02

    .........................................................................194 Introduction.....................................................................194 1991 Gulf War (Multilateral Case).................................196 Bay of Pigs (Unilateral Case)..........................................219..........................................140 7.1 Sequential Model of Bush?s Gulf War Use of Force Decision Making..210 7.2 Sequential Model of Kennedy?s Use of Force Decision Making............234 7.3 Sequential Model of Bush?s Panama Use of Force Decision Making....247 x...

  2. Robotic unilateral and bilateral upper-limb movement training for stroke survivors afflicted by chronic hemiparesis.

    PubMed

    Simkins, Matt; Kim, Hyuchul; Abrams, Gary; Byl, Nancy; Rosen, Jacob

    2013-06-01

    Stroke is the leading cause of long-term neurological disability and the principle reason for seeking rehabilitative services in the US. Learning based rehabilitation training enables independent mobility in the majority of patients post stroke, however, restoration of fine manipulation, motor function and task specific functions of the hemiplegic arm and hand is noted in fewer than 15% of the stroke patients. Brain plasticity is the innate mechanism enabling the recovery of motor skills through neurological reorganization of the brain as a response to limbs' manipulation. The objective of this research was to evaluate the therapeutic efficacy for the upper limbs with a dual arm exoskeleton system (EXO-UL7) using three different modalities: bilateral mirror image with symmetric movements of both arms, unilateral movement of the affected arm and standard care. Five hemiparetic subjects were randomly assigned to each therapy modality. An upper limb exoskeleton was used to provide bilateral and unilateral treatments. Standard care was provided by a licensed physical therapist. Subjects were evaluated before and after the interventions using 13 different clinical measures. Following these treatments all of the subjects demonstrated significant improved of their fine motor control and gross control across all the treatment modalities. Subjects exhibited significant improvements in range of motion of the shoulder, and improved muscle strength for bilateral training and standard care, but not for unilateral training. In conclusion, a synergetic approach in which robotic treatments (unilateral and bilateral depending on the level of the motor control) are supplemented by the standard of care may maximize the outcome of the motor control recover following stroke. PMID:24187321

  3. Unilateral lower limb suspension: integrative physiological knowledge from the past 20 years (1991–2011)

    Microsoft Academic Search

    K. J. Hackney; L. L. Ploutz-Snyder

    In 1991, Hans Berg and colleagues published the first research investigation using unilateral lower limb suspension (ULLS)\\u000a as a human model to study the influence of unloading on skeletal muscle. ULLS requires a participant to perform all activities\\u000a with axillary crutches while wearing one thick-soled shoe. The elevated shoe eliminates ground contact with the adjacent foot,\\u000a thereby unloading the lower

  4. Unilateral inferior temporal lobectomy with hippocampectomy for relief of incisural herniation

    Microsoft Academic Search

    W. B. Scoville; D. B. Bettis

    1979-01-01

    Summary 1.The syndrome of incisural hippocampal herniation, accompanied by unilateral and then bilateral fixed pupils, deepening coma, respiratory irregularity (Cheyne-Stokes), contralateral hemiplegia, ipsilateral decerebrate posturing, rising blood pressure, and finally renal shutdown, indicates a terminal state that requires immediate relief.2.Accepted methods of relief by brain shrinkage, dexamethasone, subtemporal decompression, anterior temporal lobectomy, cutting of the tentorium, and even massive uncapping

  5. Auditory Abilities after Cochlear Implantation in Adults with Unilateral Deafness: A Pilot Study

    PubMed Central

    Firszt, Jill B.; Holden, Laura K.; Reeder, Ruth M.; Waltzman, Susan B.; Arndt, Susan

    2012-01-01

    Objective This pilot study examined speech recognition, localization, temporal and spectral discrimination and subjective reports of cochlear implant (CI) recipients with unilateral deafness. Study Design Three adult males with short-term unilateral deafness (< 5 years) participated. All had sudden onset of severe to profound hearing loss in one ear, which then received a CI, and normal or near normal hearing in the other ear. Speech recognition in quiet and noise, localization, discrimination of temporal and spectral cues and a subjective questionnaire were obtained over several days. Listening conditions were CI, normal hearing (NH) ear, and bilaterally (CI and NH). Results All participants had open-set speech recognition and excellent audibility (250–6000 Hz) with the CI. Localization improved bilaterally compared to the NH ear alone. Word recognition in noise was significantly better bilaterally than with the NH ear for two participants. Sentence recognition in various noise conditions did not show significant bilateral improvement; however, the CI did not hinder performance in noise even when noise was toward the CI side. The addition of the CI improved temporal difference discrimination for two participants and spectral difference discrimination for all participants. Participants wore the CI full time and subjective reports were positive. Conclusion Overall, the CI recipients with unilateral deafness obtained open-set speech recognition, improved localization, improved word recognition in noise, and improved perception of their ability to hear in everyday life. A larger study is warranted to further quantify the benefits and limitations of cochlear implantation in individuals with unilateral deafness. PMID:22935813

  6. Coupling analysis at the coupler and edge-coupled unilateral fin line

    Microsoft Academic Search

    Humberto C. Fernandes; Sidney A. Silva; Jose P. Silva

    1998-01-01

    Computer programs are developed in FORTRAN 77 and Matlab for Windows languages, given the results in 3-D of the dispersion and of the coupling, as functions of the frequency, conductivity and permittivity for the unilateral fin lines coupler asymmetric in E-plane, on semiconductor substrate. The characteristic impedance and complex propagation constant, for the odd and even-modes excitation are obtained by

  7. Spinal manipulation results in immediate H-reflex changes in patients with unilateral disc herniation

    Microsoft Academic Search

    Y. Floman; N. Liram; A. N. Gilai

    1997-01-01

    The aim of this clinical investigation was to determine whether the abnormal H-reflex complex present in patients with S 1 nerve root compression due to lumbosacral disc herniation is improved by single-session lumbar manipulation. Twenty-four patients with unilateral disc herniation at the L5-S1 level underwent spinal H-reflex electro-physiological evaluation. This was carried out before and after single-session lumbar manipulation in

  8. Effect of unilateral forced nostril breathing on tonic accommodation and intraocular pressure

    Microsoft Academic Search

    Jennifer C. Chen; Brian Brown; Katrina L. Schmid

    2004-01-01

    \\u000a Abstract\\u000a \\u000a Background\\u000a   Unilateral forced nostril breathing (UFNB) has specific measurable effects on the autonomic nervous system. Ocular accommodation, which is controlled by the autonomic nervous system, would be expected to be under the influence of UFNB when it is applied. The purpose of this study was to investigate the effect of UFNB on the resting state of the accommodation system,

  9. Common and uncommon adult unilateral renal masses other than renal cell carcinoma

    PubMed Central

    Le, Ott; Roy, Anjali; Silverman, Paul M.; Kundra, Vikas

    2012-01-01

    Abstract Many different masses can involve the kidney other than the commonly encountered renal cell carcinoma (RCC). The purpose of this article is to review the characteristic clinical and imaging findings of common and uncommon masses that predominantly present unilaterally in the adult patient, other than RCC. Awareness of such lesions and knowing the clinical scenario is important for appropriate diagnosis and management, especially in a multidisciplinary care setting. PMID:22752221

  10. Unilateral transurethral incision for primary bladder neck obstruction: symptom relief and fertility preservation

    Microsoft Academic Search

    Wachira Kochakarn; Panuwat Lertsithichai

    2003-01-01

    Our aim was to review the results of unilateral transurethral incision (TUI) of the bladder neck for the treatment of primary bladder neck obstruction. A total of 35 patients with the mean age of 40.31 years were included in the study. The international prostate symptom score (I-PSS), quality of life (QoL) score, uroflowmetry and sperm count were determined. The mean preoperative

  11. Sensory strategies in human postural control before and after unilateral vestibular neurotomy

    Microsoft Academic Search

    M. Lacour; J. Barthelemy; L. Borel; J. Magnan; C. Xerri; A. Chays; M. Ouaknine

    1997-01-01

    Vestibular inputs tonically activate the antigravitative leg muscles during normal standing in humans, and visual information\\u000a and proprioceptive inputs from the legs are very sensitive sensory loops for body sway control. This study investigated the\\u000a postural control in a homogeneous population of 50 unilateral vestibular-deficient patients (Ménière’s disease patients).\\u000a It analyzed the postural deficits of the patients before and after

  12. Relocation of ventricular catheter trough ventriculostomy due to congenital unilateral hydrocephalus: Nine year follow-up

    PubMed Central

    Zoran, Milenkovic J.; Biljana, Stevanovic S.; Ivana, Markovic P.

    2011-01-01

    Background: Congenital unilateral hydrocephalus is an uncommon entity occurring almost exclusively in children. Atresia, stenosis, membranous occlusion and even functional obstruction of the foramen of Monro have been described to be the main cause of this type of hydrocephalus. There are two options available in the surgical management of unilateral hydrocephalus: one is the placement of shunt CSF diversion from the dilated ventricle and the other is fenestration of the occluded foramen of Monro or septum pellucidum by endoscopy or by stereotactic method. Migration of the ventriculoperitoneal (VP) shunt in or out of ventricles is not so uncommon, but the relocation of the ventricular tip of a catheter from the ventricle into the quadrigeminal cisterns and superior vermis in association with ventriculostomy is extremely rare. Spontaneous ventriculostomy is a rare event and results from spontaneous rupture of a ventricle into the subarachnoid space. Case Description: A 5½-month-old baby with a right-sided congenital unilateral hydrocephalus underwent a VP shunt andhad experienced an uneventful outcome. Four years later on an MR imaging examination, the tip of the ventricular catheter passing through the medial wall of the ventricle and the quadrigeminal cistern was found to be situated in the superior vermis. During the follow-up period, there were no neurological difficulties. The cognitive and motor skill development corresponded well with the child's age. It transpired that the hydrocephalic ventricle reduced its size dramatically to normal. Conclusion: We have described the extremely rare site of the relocation of the ventricular catheter after the treatment of the congenital unilateral hydrocephalus by VP shunting. Spontaneous ventriculostomy as a rare phenomenon may be the explanation of the relocation of the ventricular catheter. PMID:22059136

  13. Two Cases of Unilateral Lichen Planus Following the Lines of Blaschko

    PubMed Central

    Yayla, Derya; O?uz, I??l Deniz; Gönül, Müzeyyen; Özhamam, Esra; Çolak, Aysel; Gül, Ülker

    2014-01-01

    A 50-year-old man and 71-year-old woman presented to our clinic with unilateral, linear, erythematous, pruritic lesions along the lines of Blaschko. On the basis of clinical and histopathological findings, the lesions were diagnosed as lichen planus with a Blaschkoian distribution, which is a rare form of lichen planus. The patients were treated with topical corticosteroids and antihistamines. PMID:25324660

  14. Routine MRI findings of the asymptomatic foot in diabetic patients with unilateral Charcot foot

    Microsoft Academic Search

    Ludger W Poll; Ernst A Chantelau

    2010-01-01

    BACKGROUND: Imaging studies of bones in patients with sensory deficits are scarce. AIM: To investigate bone MR images of the lower limb in diabetic patients with severe sensory polyneuropathy, and in control subjects without sensory deficits. METHODS: Routine T1 weighted and T2-fat-suppressed-STIR-sequences without contrast media were performed of the asymptomatic foot in 10 diabetic patients with polyneuropathy and unilateral inactive

  15. Steady-state pattern electroretinogram following long term unilateral administration of timolol to ocular hypertensive subjects

    Microsoft Academic Search

    Ronit Nesher; Gary L. Trick; Michael A. Kass; Mae O. Gordon

    1990-01-01

    To determine whether long-term reduction of intraocular pressure leads to a corresponding preservation of the pattern electroretinogram (PERG), PERGs were studied in 21 patients with ocular hypertension who had received unilateral timolol therapy for a minimum of 6 years. The mean difference in intraocular pressure (IOP) between the placebotreated and the timolol-treated eyes (over 6 years) was 2.4mm Hg. Steady-state

  16. High risk of unilateral recurrent laryngeal nerve paralysis after esophagectomy using cervical anastomosis

    Microsoft Academic Search

    L. Pertl; J. Zacherl; G. Mancusi; J. N. Gächter; R. Asari; S. Schoppmann; W. Bigenzahn; B. Schneider-Stickler

    The goal of this study was to estimate the incidence of temporary and permanent unilateral recurrent laryngeal nerve paralysis\\u000a (URLNP) after esophagectomies with cervical anastomosis and to determine the impact of surgical technique, tumor type, tumor\\u000a localization and age on the incidence of URLNP. From March 2002 to November 2009, 84 patients underwent a laryngoscopical\\u000a evaluation before and after esophagectomy

  17. Left unilateral dysgraphia in a patient with an atypical pattern of handedness: A cognitive analysis

    Microsoft Academic Search

    Pascal Zesiger; Eugène Mayer

    1992-01-01

    Certain patients with a lesion of the corpus callosum have been reported as exhibiting unusual writing difficulties with their non-dominant hand. This deficit has been termed unilateral agraphia and classically interpreted as a disconnection between left-hemisphere language centres and right-hemisphere motor areas. The present study was designed to investigate the writing abilities of both hands of a corpus callosum-lesioned patient

  18. Bilateral diffuse choroidal hemangiomas with unilateral facial nevus flammeus in Sturge–Weber Syndrome

    Microsoft Academic Search

    Arezo Amirikia; Ingrid U Scott; Timothy G Murray

    2000-01-01

    PURPOSE: To report bilateral choroidal hemangiomas associated with unilateral facial nevus flammeus in Sturge–Weber syndrome.METHODS: Case report.RESULTS: A 6-year-old male with a left facial nevus flammeus and a history of a left cerebral angioma had been followed 2 years for increasing esotropia. Examination demonstrated bilateral diffuse choroidal hemangiomas with overlying exudative retinal detachments. After bilateral external beam radiotherapy, the retinal

  19. Normative Temporal Values of CRP and ESR in Unilateral and Staged Bilateral TKA

    Microsoft Academic Search

    Kwan Kyu Park; Tae Kyun Kim; Chong Bum Chang; Su Won Yoon; Kyoung Un Park

    2008-01-01

    C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) play helpful roles in determining the presence of infection\\u000a after TKA. To provide baseline values, we documented normative temporal values of CRP and ESR in unilateral and staged bilateral\\u000a TKAs for osteoarthritis. Levels of CRP and ESR were evaluated before surgery and on the first, second, fifth, seventh, fourteenth,\\u000a forty-second, and ninetieth

  20. Unilateral rhino–orbital–cerebral mucormycosis with contralateral endogenous fungal endophthalmitis

    PubMed Central

    Ho, Hao Chi; Liew, On Heong; Teh, Swee Sew; Hanizasurana, Hashim; Ibrahim, Mohtar; Shatriah, Ismail

    2015-01-01

    Rhino–orbital–cerebral mucormycosis (ROCM) is an uncommon but fatal fungal infection. We report a rare case of unilateral ROCM with ipsilateral central retinal artery occlusion and contralateral choroiditis, which later progressed to endogenous fungal endophthalmitis. The patient was successfully treated with sinuses debridement, systemic liposomal amphotericin B, and intravitreal amphotericin B. The endophthalmitis completely resolved with good vision, but the ROCM eye remained blind due to central retinal artery occlusion. PMID:25848206

  1. C- fos expression in the rat brain after unilateral labyrinthectomy and its relation to the uncompensated and compensated stages

    Microsoft Academic Search

    C. Cirelli; M. Pompeiano; P. D'Ascanio; P. Arrighi; O. Pompeiano

    1996-01-01

    The expression of the immediate early gene c-fos has been studied in the entire brain of rats 3, 6 and 24 h after surgical unilateral labyrinthectomy. We combinedin situ hybridization for c-fos messenger RNA with immunocytochemistry for Fos protein to document very early changes in c-fos expression and to identify with cellular resolution neuronal populations activated by unilateral labyrinthectomy. Three

  2. Altered Regulation of Renin-Angiotensin, Endothelin and Natriuretic Peptide Systems in Rat Kidney with Chronic Unilateral Ureteral Obstruction

    Microsoft Academic Search

    Eun Hui Bae; In Jin Kim; Jeong Woo Park; Seong Kwon Ma; Ki Chul Choi; Jong Un Lee; Soo Wan Kim

    2007-01-01

    Background: The present study was designed to investigate the role of the local renin-angiotensin-aldosterone system (RAAS), endothelin (ET) and the natriuretic peptide system (NPS) for the development of renal fibrosis and progressive renal disease in experimental unilateral ureteral obstructed (UUO) rats. Methods: Male Sprague-Dawley rats (180–200 g) were unilaterally obstructed by ligation of the proximal ureters for 14 days. Control

  3. Values of Ultrasonography, Sestamibi Scintigraphy, and Intraoperative Measurement of 1-84 PTH for Unilateral Neck Exploration of Primary Hyperparathyroidism

    Microsoft Academic Search

    Yves Chapuis; Yvonne Fulla; Philippe Bonnichon; Emmanuel Tarla; Bassam Abboud; Jol Pitre; Bruno Richard

    1996-01-01

    . Unilateral neck exploration (UNE) is a controversial approach to the treatment of primary hyperparathyroidism (PHP),\\u000a and most surgeons favor bilateral neck exploration. The aim of this study was to assess the value of ultrasonography, sestamibi\\u000a scintigraphy, and intraoperative measurement of urinary cyclic AMP (UcAMP) or 1-84 PTH in 200 patients undergoing unilateral\\u000a neck exploration under local anesthesia. Conditions for

  4. Unilateral proptosis in thyroid eye disease with subsequent contralateral involvement: retrospective follow-up study

    PubMed Central

    2013-01-01

    Background The purpose of this retrospective follow-up study is to evaluate the prevalence of patients with thyroid eye disease presenting with apparent unilateral proptosis and determine the occurrence of exophthalmos in contralateral non-proptotic eye over the time. Associated features with this event were evaluated. Methods A cohort of 655 consecutive patients affected by thyroid eye disease with a minimum follow-up of 10 years was reviewed. Exophthalmos was assessed by using both Hertel exophthalmometer and computed tomography (CT). The influence of age, gender, hormonal status and of different therapies such as corticosteroids, radiotherapy and surgical decompression on this disease progression was evaluated. Results A total of 89 patients (13.5%) (95% confidence interval [CI] 15%-10%) had clinical evidence of unilateral exophthalmos at the first visit. Among these, 13 patients (14%) (95% CI 22%-7%) developed subsequent contralateral exophthalmos. The increase of protrusion ranged from 2 to 7 mm (mean of 4.2). The time of onset varied from 6 months to 7 years (mean time: 29 months). Smoking status, young age and surgical decompression are significantly associated with development of contralateral proptosis (p< .05). Conclusions Asymmetric thyroid eye disease with the appearance of unilateral exophthalmos at the initial examination is a fairly frequent event, while subsequent contralateral proptosis occurs less commonly. However, physicians should be aware that young patients, particularly if smokers, undergoing orbital decompression in one eye may need further surgery on contralateral side over time. PMID:23721066

  5. Determinants of autobiographical memory in patients with unilateral temporal lobe epilepsy or excisions.

    PubMed

    St-Laurent, Marie; Moscovitch, Morris; Levine, Brian; McAndrews, Mary Pat

    2009-09-01

    Patients with unilateral temporal lobe epilepsy from hippocampal origin and patients with unilateral surgical excision of an epileptic focus located in the medial temporal lobe were compared to healthy controls on a version of the Autobiographical Interview (AI) adapted to assess memory for event-specific and generic personal episodes. For both types of episodes, patients with unilateral (left and right) temporal lobe epilepsy or excision (TLE) reported fewer internal details, which are bits of information pertaining to the recollected episode. The source of this deficit was mainly the paucity of perceptual information about the personal episodes, but temporal and spatial information was also deficient. Information about the episode's story elements was preserved in both AM conditions. Participants were also tested on a script generation task to assess retrieval of semantic information. Patients with TLE excision, but not pre-surgical patients, reported significantly fewer actions per script in comparison to controls, suggesting that the temporal neocortex is more involved than mesial temporal structures in recall of this type of information. Together, these results indicate that the hippocampus is essential to the recollection of sensory perceptual aspects of past experiences. Detailed story elements and gist information, as collected during the AI and the script generation task, respectively, are more resilient to hippocampal damage. The similarity of the impairment between the event-specific and the generic memory conditions also suggests that temporal specificity is not a key determinant of hippocampal engagement in autobiographical retrieval. PMID:19524089

  6. Aldosterone deficiency after unilateral adrenalectomy for Conn’s syndrome: a case report and literature review

    PubMed Central

    Yorke, Ekua; Stafford, Sara; Holmes, Daniel; Sheth, Sachiv; Melck, Adrienne

    2015-01-01

    Introduction Approximately 35% of cases of Conn’s syndrome (primary aldosteronism) result from a solitary functioning adrenal adenoma, and these patients are best managed by adrenalectomy. Postoperative hypoaldosteronism after unilateral adrenalectomy is uncommon. Case presentation We present a case and literature review of hypoaldosteronism after unilateral adrenalectomy for Conn’s syndrome, which demonstrates the insidious and sometimes delayed presentation. Discussion In this clinical case we summarize the previously published cases of post-adrenalectomy hypoaldosteronism based on a PUBMED and EBSCOhost search of all peer-reviewed publications (original articles and reviews) on this topic. A few cases of aldosterone insufficiency post-adrenalectomy for Conn’s syndrome were identified. The etiological factors for prolonged selective suppression of aldosterone secretion after unilateral adrenalectomy remain unclear. Conclusion It is important to be aware of the risk of postoperative hypoaldosteronism in this patient population. Close postoperative follow-up is necessary and strongly recommended, especially in patients with certain risk factors. Patients may need mineralocorticoid supplementation during this period. PMID:25604311

  7. Unilateral periventricular heterotopia and epilepsy in a girl with Ehlers–Danlos syndrome

    PubMed Central

    Savasta, Salvatore; Verrotti, Alberto; Spartà, Maria Valentina; Foiadelli, Thomas; Villa, Maria Pia; Parisi, Pasquale

    2015-01-01

    Purpose Ehlers–Danlos syndrome (EDS), comprising a variety of inherited connective tissue disorders, has already been described in association with various neurological features, particularly with epilepsy and periventricular heterotopia (PH). Until now, there are reports of only bilateral periventricular heterotopia associated with Ehlers–Danlos syndrome. Methods and results Here we describe a 1-year, 4-month-old female who came under our care in the Pediatric Emergency Room because of prolonged afebrile generalized seizures, whose clinical picture allowed us to suspect a diagnosis of Ehlers–Danlos syndrome. Neuroradiological investigations showed unilateral periventricular heterotopias, and genetic analyses confirmed the hypothesized diagnosis, identifying in particular a mutation in the COL5A1 gene. After starting anticonvulsant therapy, her seizures showed a good response with seizure control and she had a favorable long-term course. Conclusion To our knowledge, this is the first report of unilateral periventricular heterotopia associated with Ehlers–Danlos syndrome. We first hypothesized a mosaicism as the cause of both, a unilateral localization of the heterotopias and a favorable long-term course with good response to anticonvulsant therapy; however, intriguingly, we could not demonstrate a mosaicism as the genetic condition in our patient and the neuroradiological findings and the favorable clinical outcome still remain unexplained. PMID:26110114

  8. Epidemiology of Unilateral Sensorineural Hearing Loss with Universal Newborn Hearing Screening

    PubMed Central

    Ghogomu, Nsangou; Umansky, Amy; Lieu, Judith E. C.

    2013-01-01

    Objective Compare the epidemiology of pediatric Unilateral Sensorineural Hearing Loss before and after implementation of Universal Newborn Hearing Screening in Missouri. Study Design Inception cohort Methods Charts of 134 children born between January 1 1990 and December 31 2007 diagnosed with Unilateral Sensorineural Hearing Loss at a single institution in Missouri were reviewed to determine the effects of Universal Newborn Hearing Screening on age of detection and etiology of hearing loss. Results Mean age of detection declined from 4.4 (SD 1.8) to 2.6 (SD 2.6) years of age while rate of detection by six months of age increased from 3% to 42%. The majority (58%) of cases had normal hearing at birth. The most common etiological category was unknown (41%) before screening and congenital (45%) after screening. The use of Magnetic Resonance Imaging has increased by 21% (2-fold) while use of Computed Tomography has declined by 8% since 2002. Yields of Connexin, Pendred, electrocardiogram, and syphilis testing were 0/48 and 2/31 before and after screening respectively. Conclusion Implementation of Universal Newborn Hearing Screening in Missouri is associated with a decrease in age of detection of Unilateral Sensorineural Hearing Loss. The majority of cases are either not present or not detectable at birth. The combination of hearing status at birth and imaging findings suggests that the majority of cases are congenital rather than of unknown etiology. PMID:23553416

  9. Assessment of self-selection bias in a pediatric unilateral hearing loss study

    PubMed Central

    Lieu, Judith E C; Dewan, Karuna

    2010-01-01

    Objective To examine the differences between participants and non-participants in a study of children with unilateral hearing loss that might contribute to selection bias. Study Design Case-control study Setting Academic pediatric otolaryngology practice Subjects and Methods Comparison of clinical and socio-demographic characteristics between the 81 participants and 78 non-participants with unilateral hearing loss in a case-control study. Results Compared to non-participants, the study participants were younger but diagnosed at an older age. Participants were more likely to have been diagnosed through a primary care screen and have normal ear anatomy, and less likely to have an attributed etiology for their unilateral hearing loss or tried assistive hearing devices. No other significant demographic, socioeconomic or clinical differences were identified. Conclusions Self-selection bias may jeopardize both internal and external validity of study results and should be evaluated whenever possible. Methods to minimize self-selection bias should be considered and implemented during the planning stages of clinical studies. PMID:20172393

  10. The changes of heart rate variability after unilateral stellate ganglion block

    PubMed Central

    Kim, Jang Jae; Lee, Hee Seung; Han, Jong In

    2010-01-01

    Background The effect of the unilateral stellate ganglion block (SGB) on cardiovascular regulation remains controversial. We wished to evaluate the changes in heart rate variability (HRV) after a unilateral stellate ganglion block in patients with head and neck pain in the present study. Methods Patients with head and neck pain (n = 89) were studied. HRV was determined before and after a C6 unilateral stellate ganglion block (right-sided SGB, 40; left-sided SGB, 49) using a paratracheal technique with 1% mepivacaine (6 ml). Results There were no significant differences in HRV indices before and after right-sided SGB. The log scale of power in the high frequency range (lnHF) was increased and ratio of power in the low frequency range (LF) to power in the high frequency range (HF) ratio was decreased after left-sided SGB. Conclusions These results demonstrated that left-sided SGB increased parasympathetic activities in patients with head and neck pain. PMID:20498813

  11. Preoperative operant circling training facilitates recovery following unilateral substantia nigra lesion in rats.

    PubMed

    Carrera, M P; Mattioli, R; Tomaz, C

    1992-07-01

    This study was undertaken to examine (1) whether pre- and/or postoperative training, using water reinforcement, to turn in circles (rotation) affects the behavioral symptoms induced by unilateral 6-hydroxydopamine (6-OHDA)-induced DA denervation of the rat substantia nigra (SN); (2) whether there was any influence of this training on the temporal pattern of recovery; and (3) whether the rotational training influences turning induced by systemic injection of dopaminergic drugs. In the first experiment, rats were trained either ipsi- or contraversive (TI or TO) to the side to be damaged 11 days before and 23 days after lesion, and tested in an open field for rotational behavior following systemic administration of apomorphine and amphetamine. In the second experiment rats were trained only before the lesion was made and tested in the open field for spontaneous circling and thigmotactic behavior. The results of the first experiment indicated maintenance of the training performance after the lesion. At the 14th day after the lesion, the ipsiversive trained group showed a higher contraversive circling frequency after apomorphine injection in relation to the contralateral trained group. In the second experiment, rats trained only before the surgery, showed asymmetrical spontaneous circling in the trained direction before and 14 days after surgery, indicating, in a drug free condition, that training direction can be restored after unilateral SN lesions, even to the contralateral body side. Moreover, thigmotactic behavior indicated a lack of habituation in an open field in unilateral lesion rats.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1417669

  12. An Experimental Lymphoscintigraphy Study in an Acute Unilateral Deep Venous Thrombosis Model

    PubMed Central

    Burma, Oktay; Uysal, Ayhan; Mitil, Hüseyin Ayd?n

    2013-01-01

    Abstract Background The aim of this study is to investigate the effect of both inguinal exploration and deep venous thrombosis on lymphatic flow in an experimental model of unilateral acute obstruction of the femoral vein. Methods and Results Eighteen male New Zealand White rabbits were the subjects of this study. The rabbits were divided into three groups; Group 1 (n=6, control), Group 2 (n=6, sham), and Group 3 (n=6, operation). After the lymphoscintigraphy was performed on the Group 1 animals, the rabbits in Group 2 and Group 3 underwent intervention. In Group 3, the femoral vein was clipped and excised. In Group 2, an inguinal incision was performed and the clip materials were placed beneath the femoral vein. After the surgical intervention, lower extremity lymphoscintigraphy by subcutaneous administration of Tc-99m nanocolloid was performed in dynamic and static manner in Groups 2 and 3 on the second, fifteenth and thirtieth days after the operation. Unilateral impairment of the lymphatic flow in the operated extremity was observed in Group 3 in the early and late postoperative period but unilateral lymphatic impairment was observed in Group 2 in only the late postoperative period. Conclusion The lymphatic impairment in an operated extremity might be the consequence of surgical intervention rather than acute venous obstruction in cases where both situations are observed. PMID:23772717

  13. Spontaneous Intracranial Hypotension Manifesting as a Unilateral Subdural Hematoma with a Marked Midline Shift

    PubMed Central

    Inamasu, Joji; Moriya, Shigeta; Shibata, Junpei; Kumai, Tadashi; Hirose, Yuichi

    2015-01-01

    Spontaneous intracranial hypotension (SIH) is a syndrome in which hypovolemia of the cerebrospinal fluid (CSF) results in various symptoms. Although its prognosis is usually benign, cases with a rapid neurologic deterioration resulting in an altered mental status have been reported. One of the characteristic radiographic findings in such cases is the presence of bilateral accumulation of subdural fluid (hematoma/hygroma). When SIH-related subdural hematoma is present only unilaterally with a concomitant midline shift, making an accurate diagnosis may be challenging, and inadvertent hematoma evacuation may result in further neurologic deterioration. We report a 58-year-old woman with an altered mental status who had visited a local hospital and in whom a brain CT showed a unilateral subdural hematoma with a marked midline shift. She was referred to our department because of her neurologic deterioration after hematoma evacuation. A CT myelography revealed a massive CSF leakage in the entire thoracic epidural space. She made a full neurologic recovery following blood patch therapy. Our case is unique and educational because the suspicion for SIH as an underlying cause of subdural hematoma is warranted in nongeriatric patients not only with bilateral but also unilateral lesions. An immediate search for CSF leakage may be important in cases with failed hematoma evacuation surgery. PMID:25969682

  14. Unilateral Blood Flow Decrease Induces Bilateral and Symmetric Responses in the Immature Brain

    PubMed Central

    Villapol, Sonia; Bonnin, Philippe; Fau, Sébastien; Baud, Olivier; Renolleau, Sylvain; Charriaut-Marlangue, Christiane

    2009-01-01

    The effects of hemodynamic changes in the developing brain have yet to be fully understood. The aim of this study was to explore the relationship between perturbations of the cerebral blood flow in the developing brain via unilateral hypoperfusion in P7 rats. As expected, nuclear caspase-3 (casp3) cleavage and DNA fragmentation were detected at 48 hours after stroke in the injured cortex. Surprisingly, casp3 was also cleaved in the contralateral cortex, although without cell death markers. Delayed (48 hours) casp3 cleavage without DNA fragmentation was also identified after unilateral common carotid artery occlusion, both in the hypoperfused cortex and the unaffected cortex, producing mirror images. Upstream calpain activation, caspase-2 cleavage, and mitochondrial cytochrome c release initiated casp3 cleavage, but did not produce preconditioning. The neuronal marker NeuN co-localized with cleaved casp3 in cortical layers II–III and VI and with gaba-amino butyric acid in layer III. Indeed, collateral supply was provided from the opposite side during carotid artery occlusion but not after reperfusion, and the number of cleaved casp3-positive cells significantly negatively correlated with the common carotid artery immediate reperfusion percentage. In summary, unilateral hypoperfusion, while insufficient to induce cell death, may active bilateral and symmetric casp3 in the P7 rat brain. Additionally, the opposite healthy hemisphere is altered due to the injury and thus should not be used as an internal control. PMID:19815715

  15. Ankle arthroscopy for ankle fractures.

    PubMed

    Sherman, Thomas I; Casscells, Nick; Rabe, Joe; McGuigan, Francis X

    2015-02-01

    In many patients who undergo open reduction-internal fixation of ankle fractures, there is a failure to achieve good clinical outcomes despite radiographic evidence of anatomic reduction. One possible reason for this is the high incidence of concomitant intra-articular pathology associated with ankle fractures that may go unrecognized using traditional open approaches. Arthroscopy in the setting of acute operative management of ankle fractures provides a means to completely assess intra-articular pathology, as well as provide direct therapeutic intervention in many instances. Arthroscopic management techniques include debridement of loose intra-articular fragments, assisted fracture reduction, microfracture of chondral injuries, and assessment of syndesmotic stability. The indications for arthroscopy in the setting of ankle fractures have not been fully defined; however, it is our practice to perform an arthroscopic assessment of all ankle fractures requiring surgical intervention. We present a sample of our experience using this technique that shows the severity of intra-articular pathology that is often found and occurs even in association with fracture patterns with seemingly innocuous radiographic appearances. PMID:25973379

  16. Slator Ranch fracture optimization study

    SciTech Connect

    Ventura, J.L.

    1985-07-01

    The Las Ovejas (Lobo) field in Zapata County, TX, is being developed actively. The field was discovered on Tenneco Oil EandP's Slator Ranch lease with the successful completion of the Sanchez-O'Brien Vaquillas Ranch Well 1. Tenneco operates all of the 17,712-acre (71 678 X 10/sup 3/-m/sup 2/) lease (with the exception of a 320-acre (1295 X 10/sup 3/-m/sup 2/) tract assigned to the Vaquillas Ranch Well 1) and has successfully completed five wells in the Lobo field subsequent to the discovery well. The Lobo interval in the Slator Ranch area is a tight gas sand, and all these wells require fracture stimulation. Because a successful fracture is essential for a good Lobo completion and because hydraulic fracturing represents a significant portion of the completed well cost, it is important to optimize this phase of the completion. The purpose of this study was to determine the following for Slator Ranch Lobo completions: an optimum fracture length as a function of permeability; whether wells should be tailed-in with bauxite, or fractured with all bauxite or sand (if an optimum tail-in does exist, to determine the optimum tail-in for a fixed fracture length as a function of permeability); the drainage area and abandonment pressure for Slator Ranch Well 2; the effect of compression on reserves; and closure pressure as a function of time and distance along the fracture for Slator Ranch Well 2.

  17. Fracture of the penis.

    PubMed

    Kamil, N; Hisham, A N; Abdullah, M; Khairullah, A

    1993-09-01

    Fracture of the penis is not an uncommon urological emergency. Six patients with this injury, treated at the Institute of Urology, General Hospital, Kuala Lumpur, since 1988, were reviewed. Their ages ranged from 21 to 30 years old (mean 25). Four cases were self-inflicted by abnormal bending and 2 cases occurred during sexual intercourse. A sudden "cracking sound", violent pain, rapid flaccidity and deformity of the penis were documented. Duration of injury at presentation ranged from 12 to 90 hours (mean 35 hours). Primary repair of the tunica albuginea with absorbable suture was performed in all cases. The results of surgery was excellent, with restoration of normal function in 4 patients (2 patients defaulted follow-up). We advocate immediate surgical repair for this injury. PMID:8183157

  18. Late auditory evoked potentials in elderly long-term hearing-aid users with unilateral or bilateral fittings.

    PubMed

    Bertoli, Sibylle; Probst, Rudolf; Bodmer, Daniel

    2011-10-01

    This study investigated the effects of long-term unilateral and bilateral amplification on central auditory processing in elderly people with symmetrical hearing loss using late auditory evoked potentials. It was hypothesized that in the unilateral setting stimulation of the aided ear would yield an acclimatization effect with larger amplitudes and shorter latencies of the components P1, N1 and P2 compared to those of the unaided ear. Auditory evoked potentials were elicited by 500, 1000 and 2000 Hz pure tones at 55, 70 and 85 dB SPL presentation level delivered either to the left or right ear. Unilaterally and bilaterally fitted experienced hearing-aid users and a control group of normally hearing adults, all aged at least 60 years, participated. The responses of the unilateral hearing-aid users did not differ significantly for any of the components P1, N1 or P2 between the aided and unaided ears, but a significant interaction between ear and frequency was present for P2 amplitudes. P2 amplitudes were significantly smaller for the 0.5- and 1-kHz stimuli and tended to be larger for the 2-kHz stimulus in the aided ear suggesting an acclimatization effect. Larger P2 amplitudes were observed in the unilaterally fitted group, which was interpreted as a correlate of more effortful auditory processing in unilaterally fitted people. PMID:21569828

  19. Unilateral and bilateral fatiguing contractions similarly alter postural stability but differently modify postural position on bipedal stance.

    PubMed

    Paillard, Thierry; Borel, Liliane

    2013-04-01

    The aim of the present study was to compare the effects of unilateral and bilateral muscle fatigue on bipedal postural control and neuromuscular activities. Nineteen subjects completed bilateral fatiguing contractions (BI group), and seventeen subjects completed unilateral fatiguing contractions (UNI group) of the quadriceps femoris. Postural control, maximal voluntary contraction (MVC) and central activation ratio (CAR) were measured before and after the completion of fatiguing tasks for both groups. Postural control was evaluated by using a force platform, which recorded the center of foot pressure (COP). MVC was quantified with an ergometer and CAR was determined with the superimposed electrical stimulation technique. Spatio-temporal COP parameters were used to evaluate postural stability (displacements of COP) and postural position (coordinates of COP) and a frequency analysis of COP excursions (wavelet transform) was performed to estimate the contribution of different neuronal loops. Postural stability, MVC and CAR were similarly affected after unilateral and bilateral fatiguing contractions. Moreover, the impairment of postural position was higher after unilateral fatiguing contractions than after bilateral fatiguing contractions. The study's results indicated that unilateral and bilateral fatigue equally disturbs postural control as well as central drive. However, unilateral muscle fatigue creates postural asymmetries while bilateral muscle fatigue does not engender any. PMID:23628361

  20. Hydraulic fracturing pressures in permeable surface layers

    Microsoft Academic Search

    Hagoort

    1978-01-01

    A theoretical analysis is presented of hydraulic fracturing pressures in permeable subsurface layers situated in a tectonically relaxed area. The analysis is based on the theory of linear poro-elasticity. Three different fracturing pressures can be distinguished: (1) fracture initiation pressure: the pressure in the borehole needed to part undamaged rock around the borehole; (2) fracture opening\\/closing pressure: the pressure in

  1. Hydraulic-Fracture-Treatment Design Simulation

    Microsoft Academic Search

    Ruma Acharya

    1988-01-01

    Hydraulic fracturing is a technique for simulating wells completed in low-permeability reservoirs. The process involves the pressurization of an isolated perforated section of the wellbore with a viscous fluid until the induced stresses exceed the formation strength, which causes a failure and thus creates the fracture. Proppants are then pumped into the newly created fracture with viscous fracturing fluid as

  2. Dry snow slab shear fracture speeds

    Microsoft Academic Search

    D. M. McClung

    2007-01-01

    Dry snow slab avalanches release by propagating shear fractures within thin weak layers underneath thicker, stronger planar slabs. In this paper, measured shear fracture speeds from small scale snow slabs are compared with theoretical estimates compatible with dynamic fracture mechanics. Given the important physical quantities including density and elastic shear modulus, it is concluded that estimated snow slab shear fracture

  3. Amifostine Protects Vascularity and Improves Unions in a Model of Irradiated Mandibular Fracture Healing

    PubMed Central

    Sarhaddi, Deniz; Tchanque-Fossuo, Catherine N.; Poushanchi, Behdod; Donneys, Alexis; Deshpande, Sagar S.; Weiss, Daniela M.; Buchman, Steven R.

    2013-01-01

    Background Pathologic fractures after irradiation (XRT) can be a devastating problem for cancer patients as XRT has a pernicious effect on bone healing in a large part due to impairment of vascularity. Our aim is to ascertain whether Amifostine (AMF), a radio-protective drug, will preserve the vascularity of the irradiated mandible, thereby improving bony healing and unions after exposure to a human equivalent dose of radiation (HEDR) in our murine model of mandibular fracture repair. Methods Rats were randomized into: Fx (n=9), XRT/Fx (n=5) and AMF/XRT/Fx (n=7). XRT/Fx and AMF/XRT/Fx underwent HEDR directed at the left hemimandible. AMF/XRT/Fx received AMF concomitantly with HEDR. All animals underwent unilateral left-mandibular osteotomy with external fixation set to a 2.1mm fracture gap. Fracture healing was allowed for 40 days prior to perfusion with Microfil. Vascular radiomorphometrics were quantified with micro-computed tomography. Results We observed a 100% rate of bony union in the non-irradiated Fx compared to 25% in XRT/Fx. Union rate in AMF/XRT/Fx more than doubled to 57%. We also saw substantial increase in Vessel Number (123%,p<0.05) and a corresponding decrease in Vessel Separation (55.5%,p<0.05) in AMF/XRT/Fx versus XRT/Fx and no differences between Fx and AMF/XRT/Fx. Conclusions We report that AMF prophylaxis maintains vascularity at levels seen in non-irradiated Fx specimens, correlating with a significant increase in bony unions after HEDR. Our results set the stage for exploration of this targeted therapy alone, and in combination with other treatments, to mitigate the harmful effects of XRT on fracture repair and bone healing in the clinical setting. PMID:24281582

  4. Hydraulic-fracture propagation in layered rock: experimental studies of fracture containment

    Microsoft Academic Search

    L. W. Teufel; J. A. Clark

    1981-01-01

    Fracture geometry is an important concern in the design of a massive hydraulic fracture treatment for improved natural gas recovery from tight gas sands. Possible prediction of vertical fracture growth and containment in layered rock requires an improved understanding of the parameters which may control fracture growth across layer interfaces. We have conducted laboratory hydraulic fracture experiments and elastic finite

  5. Hydraulic fracture propagation in layered rock: experimental studies of fracture containment

    Microsoft Academic Search

    L. W. Teufel; J. A. Clark

    1981-01-01

    Fracture geometry is an important concern in the design of a massive hydraulic fracture treatment for improved natural gas recovery from tight gas sands. Possible prediction of vertical fracture growth and containment in layered rock requires an improved understanding of the parameters which may control fracture growth across layer interfaces. Laboratory hydraulic fracture experiments and elastic finite element studies have

  6. Nonlinear fracture mechanics. Volume 1. Time-dependent fracture

    SciTech Connect

    Saxena, A.; Landes, J.D.; Bassani, J.L.

    1989-01-01

    Various papers on time-dependent fracture in nonlinear fracture mechanics are presented. Individual subjects considered include: numerical study of non-steady-state creep at stationary crack tips, crack growth in small-scale creep, growth of macroscopic cracks by void coalescence under extensive creeping conditions, creep embrittlement susceptibility and creep crack growth behavior in low-alloy steels, and experimental determination of the high-temperature crack growth behavior of Incoloy 800H. Also discussed are: three-dimensional transient analysis of a dynamically loaded three-point-bend ductile fracture specimen, experimental study of the validity of a Delta J criterion for fatigue crack growth, combined-mode low-cycle fatigue crack growth under torsional loading, fatigue crack-tip mechanics in 7075-T6 aluminum alloy from high-sensitivity displacement field measurements, and nonlinear fracture of concrete and ceramics.

  7. Compression Fracture in Postpartum Osteoporosis

    PubMed Central

    Kim, Tae-Hee; Jeon, Dong-Su; Byun, Dong Won

    2013-01-01

    Osteoporosis is mainly a problem in postmenopausal women. However, we had a case of postpartum compression fracture associated with osteoporosis. A 42-year-old multiparous woman had undergone tertiary cesarean section without complications 1 month before. She was breast-feeding her baby and had no other bone-related complication history. She did not exercise on a regular basis. She experienced back pain abruptly and was diagnosed with a recent compression fracture of T12, L1, and L3. We evaluated this rare case of postpartum osteoporosis and compression fracture. PMID:24524068

  8. Dynamic fracture toughness of glass

    NASA Technical Reports Server (NTRS)

    Kobayashi, A. S.; Emery, A. F.; Liaw, B. M.

    1983-01-01

    Experimentally determined dynamic crack propagation histories in wedge-loaded, modified tapered, and rectangular double cantilever beam specimens were used to drive a dynamic finite element code in its generation phase. The resultant dynamic fracture toughness versus crack velocity relation, during the initial crack acceleration phase of these dynamic fracture specimens, was erratic but followed the standard Gamma-shaped curves of brittle polymers and metals during subsequent crack propagation at terminal velocity and crack deceleration phases. The distinct initiation phase of dynamic crack propagation, which was not observed in dynamic fracture of brittle polymer and metal specimens, is attributed to the lower stored energy in the glass specimen.

  9. Fracture problems in composite materials.

    NASA Technical Reports Server (NTRS)

    Erdogan, F.

    1972-01-01

    In this paper a series of fracture problems in composite materials are identified, their methods of solution are briefly discussed, and some sample results are presented. The main problem of interest is the determination of the stress state in the neighborhood of localized imperfections such as cracks and inclusions which may exist in the composite. Particular emphasis is placed on the evaluation of quantities such as the stress intensity factors, the power of the stress singularity, and the strain energy release rate, which may be used directly or indirectly in connection with an appropriate fracture criterion for the prediction of fracture initiation and propagation load levels.

  10. Studying Cryogenic Fracturing Process and Fracture Morphology using Transparent Specimens

    NASA Astrophysics Data System (ADS)

    Cha, M.; Yin, X.; Kneafsey, T. J.; Wu, Y. S.; Alqahtani, N.; Patterson, T.; Yao, B.; Miskimins, J.

    2014-12-01

    Cryogenic fracturing exploits thermal gradient and resulting local tensile stress to initiate fractures / cracks on a surface exposed to cryogenic fluids. This study investigates the development and morphology of cracks generated from cryogenic thermal shock in a borehole geometry. The study evaluates cryogenic thermal shock under no external confining stress to specimens. To better understand this process in a geometry relevant to applications, a borehole was drilled through transparent acrylic specimens representing a wellbore. This borehole was partially cased with stainless steel tubing set by a high yield epoxy. Liquid nitrogen was injected into the wellbore through a stainless steel tube. The pressure was low (< 10 psia) and the fractures were initiated by the thermal shock; these initiated fractures allowed further penetration of the cryogen, which helped to propagate fractures throughout the specimen. A major advantage of performing this experiment in a transparent cryogenic specimen is the ability to observe fracture proliferation through time. It is observed that fracture growth was characterized by abrupt starts and stops, which suggest that the tensile stress generated inside the borehole must reach a certain threshold for fracture initiation and growth. Two distinctive patterns in crack development were observed: one is horizontal-planar-radial pattern created by longitudinal thermal contraction, and another is vertical cracks by circumferential contraction. The horizontal cracks appeared to be spaced by a certain length, known as the exclusion distance, which exists because a set of cracks cannot be created closer than a certain length due to limited amount of thermal contraction. The vertical tension cracks tend to initiate between the horizontal radial cracks and bridge them, as it may be energy-efficient to start from and propagate to existing defects.

  11. Effect of Intravenous Methylprednisolone on Pain after Intertrochanteric Femoral Fracture Surgery

    PubMed Central

    Rahimzadeh, Poupak; Imani, Farnad; Nikoubakht, Nasim; Sayarifard, Azadeh

    2014-01-01

    Background: Pain after surgery is one of the major problems in patients with intertrochanteric fracture. This study investigates administration of single-dose Methylprednisolone prior to surgery with the goal of reducing Post-operative pain. Materials and Methods: The study was a Double Blind Randomized Clinical Trial. Eighty two patients with stable intertrochanteric unilateral fracture were selected and divided into two groups: one received Methylprednisolone (MP) 125 mg and the other received placebo. Pain was evaluated at rest and 45° flexion of the hip in times 4, 6, 8, 12, 24, 36, and 48 hours and during walking in times 24, 36, and 48 hours after the surgery. Post-operative nausea, vomiting and fatigue and changes in C - reactive protein (CRP) levels before and after the surgery were also recorded. Results: Pain at rest, 45° flexion of the hip and during walking after the surgery was significantly lower in the MP group compared to the control group (p < 0.001). Fatigue (p = 0.002) and changes in CRP (p=0.001) were significantly lower in MP group. Incidence of nausea, vomiting (p = 0.37) and opioid consumption (p = 0.49) were not significantly different between the two groups. Conclusion: Single-dose methylprednisolone 125 mg (IV) can reduce Post-operative pain in patients with intertrochanteric fracture undergoing elective surgery. PMID:24959459

  12. Simultaneous Bilateral Femoral Neck Stress Fracture in a Young Stone Mason

    PubMed Central

    Khadabadi, Nikhil A.; Patil, Kiran S.

    2015-01-01

    Unilateral stress fractures of the femoral neck are very uncommon and bilateral involvement is even rarer. They commonly occur in athletes, military recruits, older persons, or individuals with underlying metabolic disorders and very seldom in normal individuals. We present a rare case of simultaneous bilateral fracture neck of femur in a 25-year-old man who came with complaints of pain in bilateral groin for 1 month. There was no history of trauma or history suggestive of excessive activity prior to the onset of pain, but there was history of lifting heavy weights daily. On evaluation with MRI scan bilateral fracture of the femur neck was diagnosed and patient was operated on bilaterally with internal fixation done using dynamic hip screw. Patient then regained his routine activity over a period of 6 months and on follow-up at 1 year no avascular necrosis changes were seen in the femur head. We presented this case because of its unusual presentation and the diagnostic challenge it poses. PMID:26101680

  13. Bilateral calcaneal stress fractures in two cats.

    PubMed

    Cantatore, M; Clements, D N

    2015-06-01

    Two cats that developed bilateral calcaneal stress fractures are reported. One cat developed lameness associated with incomplete fractures at the base of both calcanei, both of which progressed to acute, complete fractures 2 months later. The second cat presented with acute complete calcaneal fracture, with evidence of remodelling of the contralateral calcaneus, which subsequently fractured two years later. The calcaneal fractures were successfully stabilised with lateral bone plates in each case. Stress fractures were suspected because of the bilateral nature, the simple and similar configuration, the consistent location of the fractures, the absence of other signs of trauma in both cases and the suspected insidious onset of the lameness. The feline calcaneus is susceptible to stress fracture, and cats presenting with calcaneal fractures without evidence of trauma should be evaluated for concurrent skeletal pathology. PMID:25929309

  14. Proximal humeral fractures: pin, plate, or replace.

    PubMed

    Neviaser, Robert J; Resch, Herbert; Neviaser, Andrew S; Crosby, Lynn A

    2015-01-01

    Proximal humeral fractures are becoming increasingly common in individuals older than 60 years, with only fractures of the hip and distal radius occurring with a higher frequency. Most proximal humeral fractures can be managed without surgery; however, if a fracture is displaced or angulated, surgical treatment may be required. There are four main options for the surgical management of proximal humeral fractures: minimally invasive percutaneous reduction and fixation, open reduction and periarticular plating, hemiarthroplasty, and reverse total shoulder arthroplasty. PMID:25745906

  15. Evaluation of hydraulic fracturing by transient pressure analysis methods

    Microsoft Academic Search

    Cinco

    1982-01-01

    A brief description is given of flow models currently used for transient pressure analysis in fractured wells. Four such models are considered: (1) infinite conductivity vertical fracture; (2) uniform flux vertical fracture; (3) uniform plan horizontal fracture; and (4) finite conductivity vertical fracture. Modified versions of these models are presented for the cases of damaged fractures and heterogeneous fractures. Methods

  16. Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present

    NASA Astrophysics Data System (ADS)

    Liu, Yuwei; Dong, Ning; Fehler, Mike; Fang, Xinding; Liu, Xiwu

    2015-06-01

    Fractures in reservoirs significantly affect reservoir flow properties in subsequent years, which means that fracture characteristics such as preferred orientation, crack density or fracture compliance, what filling is in the fractures and so on are of great importance for reservoir development. When fractures are vertical, aligned and their dimensions are small relative to the seismic wavelength, the medium can be considered to be an equivalent horizontal transverse isotropic (HTI) medium. However, geophysical data acquired over naturally fractured reservoirs often reveal the presence of multiple fracture sets. We investigate a case where there are two vertical sets of fractures having differing length scales. One fracture set has length scale that is much smaller than the seismic wavelength but the other has length scale that is similar to the seismic wavelength. We use synthetic data to investigate the ability to infer the properties of the small-scale fractures in the presence of the large-scale fracture set. We invert for the Thomsen-type anisotropic coefficients of the small-scale fracture set by using the difference of the P wave amplitudes at two azimuths, which makes the inversion convex. Then we investigate the influence of the presence of the large-scale fractures on our ability to infer the properties of the small-scale fracture set. Surprisingly, we find that we can reliably infer the fracture density of the small-scale fractures even in the presence of large-scale fractures having significant compliance values. Although the inversion results for Thomsen-type anisotropic coefficients of small-scale fractures for one model are not good enough to figure out whether it is gas-filled or fluid-filled, we can find a big change of Thomsen-type anisotropic coefficient {{\\varepsilon}(V)} between the models in which small-scale fractures are filled with gas and fluid.

  17. Patellar Fracture Following Patellofemoral Arthroplasty.

    PubMed

    King, Alexander H; Engasser, William M; Sousa, Paul L; Arendt, Elizabeth A; Dahm, Diane L

    2015-07-01

    This study aims to report the incidence of patellar fracture after patellofemoral arthroplasty (PFA) and to determine associated factors as well as outcomes of patients with and without this complication. 77 knees in 59 patients with minimum two-year follow-up were included. Seven (9.1%) patients experienced a patellar fracture at a mean of 34 (range 16-64) months postoperatively. All were treated nonoperatively. Lower BMI (P = 0.03), change in patellar thickness (P < 0.001), amount of bone resected (P = 0.001), and larger trochlear component size (P = 0.01) were associated with a greater incidence of fracture. Fewer fractures occurred when the postoperative patellar height exceeded the preoperatively measured height. No statistically significant differences were found in outcome scores between groups at mean four-year follow-up. PMID:25737384

  18. Fracture of aluminum naval structures

    E-print Network

    Galanis, Konstantinos, 1970-

    2007-01-01

    Structural catastrophic failure of naval vessels due to extreme loads such as underwater or air explosion, high velocity impact (torpedoes), or hydrodynamic loads (high speed vessels) is primarily caused by fracture. ...

  19. Viscoelastic fracture of biological composites

    NASA Astrophysics Data System (ADS)

    Bouchbinder, Eran; Brener, Efim A.

    2011-11-01

    Soft constituent materials endow biological composites, such as bone, dentin and nacre, with viscoelastic properties that may play an important role in their remarkable fracture resistance. In this paper we calculate the scaling properties of the quasi-static energy release rate and the viscoelastic contribution to the fracture energy of various biological composites, using both perturbative and non-perturbative approaches. We consider coarse-grained descriptions of three types of anisotropic structures: (i) liquid-crystal-like composites, (ii) stratified composites, (iii) staggered composites, for different crack orientations. In addition, we briefly discuss the implications of anisotropy for fracture criteria. Our analysis highlights the dominant lengthscales and scaling properties of viscoelastic fracture of biological composites. It may be useful for evaluating crack velocity toughening effects and structure-dissipation relations in these materials.

  20. Seismic anisotropy of fractured rock

    E-print Network

    M. Schoenberg, C. M. Sayers

    2000-02-18

    Henyey, F., and Pomphrey, N., 1982, Self-consistent moduli of a cracked solid: ... Reiss, L., 1980, The reservoir engineering aspects of fractured formations: ... Schoenberg, M., 1983, Reflection of elastic waves from periodically stratified media ...

  1. Scaphoid Fracture of the Wrist

    MedlinePLUS

    ... when a cast was needed for a long time or when the fracture required more extensive surgery. It is very important to maintain full ? nger motion throughout the recovery period. Your doctor will provide ...

  2. Computed tomography of calcaneal fractures

    SciTech Connect

    Heger, L.; Wulff, K.; Seddiqi, M.S.A.

    1985-07-01

    Computed tomography (CT) of 25 fractured calcanei was performed to investigate the potential of CT in evaluating the pattern and biomechanics of these fractures. The characteristic findings of typical fractures are presented, including the number and type of principal fragments, size and dislocation of the sustentacular fragment, and involvement of the anterior and posterior facets of the subtalar joint. In 17 cases, the calcaneus consisted of four or more fragments. Furthermore, in 17 cases the sustentacular fragment included all or part of the posterior facet joint. In 18 of the 25 cases, the sustentacular fragment was displaced. It is concluded that well performed CT is an invaluable adjunct in understanding the fracture mechanism and in detecting pain-provoking impingement between the fibular malleolus and the tuberosity fragment.

  3. Fracture Mechanics and Failure Analysis

    E-print Network

    New South Wales, University of

    Analysis (Weeks 7-12) Prof Alan Crosky 10 General practice in failure analysis 7 11 Ductile and brittle Final exam Course Outline Fracture mechanics, remnant life assessment, general practice in failure

  4. Hydrostructural Characterization of Fracture Networks

    NASA Astrophysics Data System (ADS)

    Doe, T. W.; Hermanson, J.

    2007-12-01

    Over the past 30 years, research in underground laboratories for radioactive waste has led to the development of integrated site investigation and modeling methods for fracture networks. These activities began with the Stripa Project in central Sweden from 1977 to 1992 and have continued worldwide. Experiments on the scale of 100- 200 meter blocks have demonstrated the effectiveness of integrating testing during drilling, pressure monitoring, geologic description, flow logging, pressure transient testing, and groundwater chemistry to define fracture network geometries, particularly with respect to the identification of major features, background fractures, and compartmentalization. Major features are those large fractures or fracture zones that control the flow at the scale of interest, and must be simulated as deterministic features. Background fractures are defined stochastically, and provide connectivity between deterministic features. Based on the experience of block-scale investigations, it is possible to develop a clear picture of hydraulic networks using an integrated structural geologic, hydraulic, and hydrochemical approach. Although fracture network characterization requires a good geologic description of fractures and fracture zones from core and image logging, not all geologic features are water-conducting. Identifying water-conducting fractures begins with measurements of flow during drilling and flow logging immediately afterwards to identify significant conducting features. Major flow features must be hydraulically isolated using multiple point piezometer systems, if subsequent investigation methods are to be successful. Once installed, the pressure responses in the piezometers to subsequent drilling provide key information on connectivity and compartmentalization. Generally with three holes are sufficient to develop initial conceptual models of the major, controlling features. Subsequent boreholes test these geometric hypotheses and provide bases for their refinement. Confirmation of the network geometries comes from pressure transient testing. Although flow logging is very useful for locating conductive fractures, their steady-flow analysis methods do not allow for skin effects or accurate determination of hydraulic properties. Transient tests using single hole and interference data provide accurate hydraulic properties of the networks as well as insights to the network geometry and its boundaries. Geochemical data provide further constraints on connectivity and compartmentalization. The hydro-structural characterization of block scale experiments at the Äspö Hard Rock Laboratory provides an example of this integration approach.

  5. Evaluation and management of toe fractures.

    PubMed

    Hatch, Robert L; Hacking, Scott

    2003-12-15

    Fractures of the toe are one of the most common lower extremity fractures diagnosed by family physicians. Toe fractures most frequently are caused by a crushing injury or axial force such as stubbing a toe. Joint hyperextension and stress fractures are less common. Most patients have point tenderness at the fracture site or pain with gentle axial loading of the digit. Anteroposterior and oblique radiographs generally are most useful for identifying fractures, determining displacement, and evaluating adjacent phalanges and digits. Referral is indicated in patients with circulatory compromise, open fractures, significant soft tissue injury, fracture-dislocations, displaced intra-articular fractures, or fractures of the first toe that are unstable or involve more than 25 percent of the joint surface. Most children with fractures of the physis should be referred, but children with selected nondisplaced Salter-Harris types I and II fractures may be treated by family physicians. Stable, nondisplaced toe fractures should be treated with buddy taping and a rigid-sole shoe to limit joint movement. Displaced fractures of the lesser toes should be treated with reduction and buddy taping. Patients with displaced fractures of the first toe often require referral for stabilization of the reduction. PMID:14705761

  6. Hydraulic conductivity of rock fractures

    Microsoft Academic Search

    Robert W. Zimmerman; Gudmundur S. Bodvarsson

    1996-01-01

    The flow of a single-phase fluid through a rough-walled rock fracture is discussed within the context of fluid mechanics. The derivation of the ‘cubic law’ is given as the solution to the Navier-Stokes equations for flow between smooth, parallel plates - the only fracture geometry that is amenable to exact treatment. The various geometric and kinematic conditions that are necessary

  7. Rotational Deformity Following Metacarpal Fracture

    Microsoft Academic Search

    S. G. ROYLE

    1990-01-01

    Ninety-one consecutive patients with 98 metacarpal fractures were looked at prospectively for rotational deformity. Whilst a quarter had minor rotation of the fracture of less than 10?, only five had more than this. In just two cases, was there rotational instability requiring operative intervention. Assessment of rotational deformity must include an end-on view of the finger-nail, as there is often

  8. Fracturing fluid characterization facility (FFCF)

    SciTech Connect

    Evans, R.D.; Roegiers, J.C.; Fagan, J.

    1993-12-31

    The Fracturing Fluid Characterization Facility project has as its main focus the design, fabrication, and construction of a high pressure simulator (HPS) and a low pressure simulator (LPS) to be used to experimentally investigate the rheological properties and transport characteristics of proppant laden fracturing fluids. A discussion of each apparatus is provided as well as the auxiliary equipment, and data acquisition and control systems associated with the simulators.

  9. Rehabilitative strategies following hand fractures.

    PubMed

    Hays, Peyton L; Rozental, Tamara D

    2013-11-01

    The importance of rehabilitation in the management of hand fractures cannot be overstated. The breadth of rehabilitative strategies ranges from heat and range-of-motion exercises to more complex splinting and tendon gliding modalities. The goals, however, are clear: control pain; limit soft tissue swelling; provide support for fracture healing; restore motion, strength, and function; and enable the return to work and daily activities. PMID:24209956

  10. Fracture morphology and viscous transport

    Microsoft Academic Search

    J. Schmittbuhl; A. Steyer; L. Jouniaux; R. Toussaint

    2008-01-01

    The morphology of a fracture in a granite block is sampled using a high resolution profiler providing a 3999×4000 pixel image of the roughness. We checked that a self-affine model is an accurate geometrical model of the fracture morphology on the basis of a spectral analysis. We also estimated the topothesy of the experimental surface to be lr?2×10-7mm and the

  11. Fracture measurements on cement paste

    Microsoft Academic Search

    D. D. Higgins; J. E. Bailey

    1976-01-01

    This paper describes an investigation into the fracture behaviour of hardened cement paste. Notched specimens of the material\\u000a were tested to failure in flexure and tension. In the initial flexural tests on beams of fixed overall depth, the stress intensity\\u000a factor at failure as calculated from linear-elastic fracture mechanics appeared to be a material constant. However, further\\u000a investigation showed that

  12. Ultrasonic Monitoring of Fracture Healing

    Microsoft Academic Search

    Vasilios C. Protopappas; Maria G. Vavva; Konstantinos N. Malizos; Demos Polyzos; Dimitrios I. Fotiadis

    \\u000a Quantitative ultrasound has been used to evaluate bone fracture healing for over five decades. Animal and clinical studies\\u000a have showed that the propagation velocity and attenuation are significantly different between fresh fractures, bone unions,\\u000a and delayed unions or non-unions. Follow-up measurements have also indicated that the velocity typically increases during\\u000a healing which makes feasible to monitor the healing progress and

  13. Seismic characteristics of tensile fracture growth induced by hydraulic fracturing

    NASA Astrophysics Data System (ADS)

    Eaton, D. W. S.; Van der Baan, M.; Boroumand, N.

    2014-12-01

    Hydraulic fracturing is a process of injecting high-pressure slurry into a rockmass to enhance its permeability. Variants of this process are used for unconventional oil and gas development, engineered geothermal systems and block-cave mining; similar processes occur within volcanic systems. Opening of hydraulic fractures is well documented by mineback trials and tiltmeter monitoring and is a physical requirement to accommodate the volume of injected fluid. Numerous microseismic monitoring investigations acquired in the audio-frequency band are interpreted to show a prevalence of shear-dominated failure mechanisms surrounding the tensile fracture. Moreover, the radiated seismic energy in the audio-frequency band appears to be a miniscule fraction (<< 1%) of the net injected energy, i.e., the integral of the product of fluid pressure and injection rate. We use a simple penny-shaped crack model as a predictive framework to describe seismic characteristics of tensile opening during hydraulic fracturing. This model provides a useful scaling relation that links seismic moment to effective fluid pressure within the crack. Based on downhole recordings corrected for attenuation, a significant fraction of observed microseismic events are characterized by S/P amplitude ratio < 5. Despite the relatively small aperture of the monitoring arrays, which precludes both full moment-tensor analysis and definitive identification of nodal planes or axes, this ratio provides a strong indication that observed microseismic source mechanisms have a component of tensile failure. In addition, we find some instances of periodic spectral notches that can be explained by an opening/closing failure mechanism, in which fracture propagation outpaces fluid velocity within the crack. Finally, aseismic growth of tensile fractures may be indicative of a scenario in which injected energy is consumed to create new fracture surfaces. Taken together, our observations and modeling provide evidence that failure mechanisms documented by passive monitoring of hydraulic fractures may contain a significant component of tensile failure, including fracture opening and closing, although creation of extensive new fracture surfaces may be a seismically inefficient process that radiates at sub-audio frequencies.

  14. Capillary fracturing in granular media

    NASA Astrophysics Data System (ADS)

    Szulczewski, Michael; Holtzman, Ran; Trojer, Mathias; Juanes, Ruben

    2013-03-01

    The invasion of gas into liquid-saturated, deformable porous media occurs in many processes including gas venting, hydrocarbon recovery, and geologic CO2 sequestration. While fracturing during gas invasion has been observed in several studies, the underlying mechanisms and macroscopic patterns remain poorly understood. Here, we experimentally investigate the fracturing mechanism and resulting patterns during the invasion of air into a thin bed of water-saturated glass beads. The control parameters are the air injection rate, the bead size, and the vertical confining stress applied to the top of the bed. We identify three invasion regimes: capillary fingering, viscous fingering, and ``capillary fracturing,'' where capillary forces overcome frictional resistance and induce the opening of fracture-like conduits. We show that the transitions between the regimes are governed by a modified capillary number and a fracturing number. We then extend the experiments to investigate the effect of wettability. Our analysis predicts the emergence of fracturing in fine-grained media under low confining stress, a phenomenon that likely plays a fundamental role in many natural systems.

  15. Global Trends in Maxillofacial Fractures

    PubMed Central

    Lee, Kai

    2012-01-01

    Background?The etiology, demographics, fracture site in facial injury patients have been reported worldwide. However, few studies have attempted to identify changes in maxillofacial fractures over time periods and between countries. The statistics are vastly different due to variations in social, environmental, and cultural factors. Methods?Data were collected from departmental records between 1996 and 2006 for patients treated at Christchurch Hospital for facial fractures. Variables examined included incidence, demographics, site of fracture, and treatment methods. Results?A total of 2563 patients presented during the study period, 1158 patients in the first half and 1404 patients in the second half. Male-to-female ratio was 4:1 in both periods and males in 16- to 30-year group accounted for about half of all patients. Interpersonal violence was the most common cause of injuries, and there was a decrease in injuries caused by motor vehicle accidents. Approximately half of all patients required hospitalization and surgery, and the most common method of treatment was open reduction and internal fixation. Conclusion?Maxillofacial fracture is a common injury in young males following interpersonal violence in New Zealand. Studies in other countries and over different time periods yield interesting differences in the etiology, demographics, and fractures patterns. These are due to environmental, societal, cultural, and legislative differences. PMID:24294404

  16. Tracer mixing at fracture intersections

    SciTech Connect

    Li, Guomin

    2001-02-10

    Discrete network models are one of the approaches used to simulate a dissolved contaminant, which is usually represented as a tracer in modeling studies, in fractured rocks. The discrete models include large numbers of individual fractures within the network structure, with flow and transport described on the scale of an individual fracture. Numerical simulations for the mixing characteristics and transfer probabilities of a tracer through a fracture intersection are performed for this study. A random-walk, particle-tracking model is applied to simulate tracer transport in fracture intersections by moving particles through space using individual advective and diffusive steps. The simulation results are compared with existing numerical and analytical solutions for a continuous intersection over a wide range of Peclet numbers. This study attempts to characterize the relative concentration at the outflow branches for a continuous intersection with different flow fields. The simulation results demonstrate that the mixing characteristics at the fracture intersections are a function not only of the Peclet number but also of the flow field pattern.

  17. Seismic attenuation in fractured media

    NASA Astrophysics Data System (ADS)

    Rao, Ying; Wang, Yanghua

    2015-02-01

    The prime objective of this paper is to quantitatively estimate seismic attenuation caused by fractures with different physical parameters. In seismic wave simulation, the fractured media are treated as the anisotropic media and fractures are represented by frequency-dependent elastic constants. Based on numerical experiments with three different parameters, namely viscosity, porosity and the Lamé parameters, this paper has the following observations. First, seismic attenuation is not affected by the viscosity within fractures, although it increases with the increase of porosity and decreases with the increase of the Lamé parameters within fractures. Among the latter two parameters, seismic attenuation is more sensitive to the Lamé parameters than to the porosity. Second, for the attenuation anisotropy, low frequencies have more anisotropic effect than high frequencies. For example, a 50?Hz wavefield has the strongest anisotropy effect if compared to 100 and 150?Hz wavefields. The attenuation anisotropy for low frequency (say 50?Hz) is more sensitive to the viscosity than the porosity and the Lamé parameters have the weakest effect among these three parameters. These observations suggest that low-frequency seismic attenuation, and especially the attenuation anisotropy in low frequency, would have great potential for fluid discrimination within fractured media.

  18. Avulsion fractures of the scapula

    SciTech Connect

    Heyse-Moore, G.H.; Stoker, D.J.

    1982-11-01

    Fractures of the scapula due to direct violence are relatively common. Wilber and Evans (18) reported 40 scapular fractures and reviewed the literature. All those injured has received direct trauma to the shoulder and they were able to divide their cases into two groups, based on anatomical location and functional results. Scapular fractures due to avulsion of the muscular attachments are uncommon and, as reports of these injuries in the literature are usually confined to single cases, no classification has been established which takes account of the anatomical sites at which these fractures occur and the mechanism of injury involved. In this paper the more common sites of avulsion injury of the scapula are described and illustrated by case reports. In several of these the skeletal injury resulted from muscle contraction against a resisted force on the upper limb during the course of an accident. This mechanism has been implicated in fractures of the coracoid and acromion, but is shown in this paper to contribute to other avulsion fractures.

  19. Capillary fracture of soft gels

    NASA Astrophysics Data System (ADS)

    Bostwick, Joshua B.; Daniels, Karen E.

    2013-10-01

    A liquid droplet resting on a soft gel substrate can deform that substrate to the point of material failure, whereby fractures develop on the gel surface that propagate outwards from the contact line in a starburst pattern. In this paper, we characterize (i) the initiation process, in which the number of arms in the starburst is controlled by the ratio of the surface tension contrast to the gel's elastic modulus, and (ii) the propagation dynamics showing that once fractures are initiated they propagate with a universal power law L?t3/4. We develop a model for crack initiation by treating the gel as a linear elastic solid and computing the deformations within the substrate from the liquid-solid wetting forces. The elastic solution shows that both the location and the magnitude of the wetting forces are critical in providing a quantitative prediction for the number of fractures and, hence, an interpretation of the initiation of capillary fractures. This solution also reveals that the depth of the gel is an important factor in the fracture process, as it can help mitigate large surface tractions; this finding is confirmed with experiments. We then develop a model for crack propagation by considering the transport of an inviscid fluid into the fracture tip of an incompressible material and find that a simple energy-conservation argument can explain the observed material-independent power law. We compare predictions for both linear elastic and neo-Hookean solids, finding that the latter better explains the observed exponent.

  20. Impact of unilateral tubal blockage diagnosed by hysterosalpingography on the success rate of treatment with controlled ovarian stimulation and intrauterine insemination.

    PubMed

    Berker, B; ?ükür, Y E; Kahraman, K; Atabeko?lu, C S; Sönmezer, M; Özmen, B; Ate?, C

    2014-02-01

    The aim of this study was to evaluate the success rates of intrauterine insemination (IUI) in infertile women with unilateral proximal and distal tubal blockage. A total of 161 couples with unilateral tubal blockage and unexplained infertility were included. The primary outcome measure was the cumulative pregnancy rate (CPR). The CPRs after three cycles of IUI were 26.3% (10/38) in patients with unilateral tubal blockage, and 44.7% (55/123) in patients with unexplained infertility (p = 0.043). CPRs were similar in patients with proximal unilateral tubal blockage and unexplained infertility (38.1% vs 44.7%, respectively, p = 0.572). CPR was significantly lower in patients with distal unilateral tubal blockage than in patients with unexplained infertility (11.7% vs 44.7%, respectively, p = 0.01). In conclusion, IVF instead of IUI may be a more appropriate approach for distal unilateral tubal blockage patients. PMID:24295028

  1. Clinician approach to diagnosis of stress fractures including bisphosphonate-associated fractures.

    PubMed

    McKenna, M J; Heffernan, E; Hurson, C; McKiernan, F E

    2014-02-01

    Stress fractures are repetitive strain injuries that occur in normal bones and in abnormal bones. Stress fractures share many features in common but differences depend on the status of the underlying bone. This review article for clinicians addresses aspects about stress fractures with particular respect to fatigue fractures, Looser zones of osteomalacia, atypical Looser zones, atypical femoral fractures associated with bisphosphonate therapy and stress fractures in Paget's disease of bone. PMID:24106312

  2. A Practical Hydraulic Fracturing Model Simulating Necessary Fracture Geometry, Fluid Flow and Leakoff, and Proppant Transport

    Microsoft Academic Search

    Usman Ahmed

    1984-01-01

    Hydraulic fracturing model using various sets of fracture flow\\/geometry equations are available in the industry. The majority of these models assume a constant fracture height selected at the start of the design, and simulate two-dimensional fracture geometry (width and length) and one dimensional fluid flow in both the fracture and the formation. The two-dimensional fracture geometry simulation can lead to

  3. Fracture opening/propagation behavior and their significance on pressure-time records during hydraulic fracturing

    SciTech Connect

    Takashi Kojima; Yasuhiko Nakagawa; Koji Matsuki; Toshiyuki Hashida

    1992-01-01

    Hydraulic fracturing with constant fluid injection rate was numerically modeled for a pair of rectangular longitudinal fractures intersecting a wellbore in an impermeable rock mass, and numerical calculations have been performed to investigate the relations among the form of pressure-time curves, fracture opening/propagation behavior and permeability of the mechanically closed fractures. The results have shown that both permeability of the fractures and fluid injection rate significantly influence the form of the pressure-time relations on the early stage of fracture opening. Furthermore it has been shown that wellbore pressure during fracture propagation is affected by the pre-existing fracture length.

  4. Optimal scaling in ductile fracture

    NASA Astrophysics Data System (ADS)

    Fokoua Djodom, Landry

    This work is concerned with the derivation of optimal scaling laws, in the sense of matching lower and upper bounds on the energy, for a solid undergoing ductile fracture. The specific problem considered concerns a material sample in the form of an infinite slab of finite thickness subjected to prescribed opening displacements on its two surfaces. The solid is assumed to obey deformation-theory of plasticity and, in order to further simplify the analysis, we assume isotropic rigid-plastic deformations with zero plastic spin. When hardening exponents are given values consistent with observation, the energy is found to exhibit sublinear growth. We regularize the energy through the addition of nonlocal energy terms of the strain-gradient plasticity type. This nonlocal regularization has the effect of introducing an intrinsic length scale into the energy. We also put forth a physical argument that identifies the intrinsic length and suggests a linear growth of the nonlocal energy. Under these assumptions, ductile fracture emerges as the net result of two competing effects: whereas the sublinear growth of the local energy promotes localization of deformation to failure planes, the nonlocal regularization stabilizes this process, thus resulting in an orderly progression towards failure and a well-defined specific fracture energy. The optimal scaling laws derived here show that ductile fracture results from localization of deformations to void sheets, and that it requires a well-defined energy per unit fracture area. In particular, fractal modes of fracture are ruled out under the assumptions of the analysis. The optimal scaling laws additionally show that ductile fracture is cohesive in nature, i.e., it obeys a well-defined relation between tractions and opening displacements. Finally, the scaling laws supply a link between micromechanical properties and macroscopic fracture properties. In particular, they reveal the relative roles that surface energy and microplasticity play as contributors to the specific fracture energy of the material. Next, we present an experimental assessment of the optimal scaling laws. We show that when the specific fracture energy is renormalized in a manner suggested by the optimal scaling laws, the data falls within the bounds predicted by the analysis and, moreover, they ostensibly collapse---with allowances made for experimental scatter---on a master curve dependent on the hardening exponent, but otherwise material independent.

  5. Modelling the graphite fracture mechanisms

    SciTech Connect

    Jacquemoud, C.; Marie, S. [CEA Saclay, Gif-sur-Yvette, (France); Nedelec, M. [IRSN/PSN-EXP/SES, Fontenay-aux-Roses, (France)

    2012-07-01

    In order to define a design criterion for graphite components, it is important to identify the physical phenomena responsible for the graphite fracture, to include them in a more effective modelling. In a first step, a large panel of experiments have been realised in order to build up an important database; results of tensile tests, 3 and 4 point bending tests on smooth and notched specimens have been analysed and have demonstrated an important geometry related effects on the behavior up to fracture. Then, first simulations with an elastic or an elastoplastic bilinear constitutive law have not made it possible to simulate the experimental fracture stress variations with the specimen geometry, the fracture mechanisms of the graphite being at the microstructural scale. That is the reason why a specific F.E. model of the graphite structure has been developed in which every graphite grain has been meshed independently, the crack initiation along the basal plane of the particles as well as the crack propagation and coalescence have been modelled too. This specific model has been used to test two different approaches for fracture initiation: a critical stress criterion and two criteria of fracture mechanic type. They are all based on crystallographic considerations as a global critical stress criterion gave unsatisfactory results. The criteria of fracture mechanic type being extremely unstable and unable to represent the graphite global behaviour up to the final collapse, the critical stress criterion has been preferred to predict the results of the large range of available experiments, on both smooth and notched specimens. In so doing, the experimental observations have been correctly simulated: the geometry related effects on the experimental fracture stress dispersion, the specimen volume effects on the macroscopic fracture stress and the crack propagation at a constant stress intensity factor. In addition, the parameters of the criterion have been related to experimental observations: the local crack initiation stress of 8 MPa corresponds to the non-linearity apparition on the global behavior observed experimentally and the the maximal critical stress defined for the particle of 30 MPa is equivalent to the fracture stress of notched specimens. This innovative combination of crack modelling and a local crystallographic critical stress criterion made it possible to understand that cleavage initiation and propagation in the graphite microstructure was driven by a mean critical stress criterion. (authors)

  6. Changes in Fracture Compliance Due to Roughness

    NASA Astrophysics Data System (ADS)

    Ahmadi, M.; Dahi Taleghani, A.; Sayers, C. M.

    2014-12-01

    Rock fractures are a source of extra compliance, and the effect of fractures on seismic wave propagation can be quantified in terms of the normal and shear fracture compliances. However, fractures are usually assumed to be smooth discontinuities with no preferential orientation for slippage. This assumption rarely matches with outcrop studies. Irregularities always exist on the fracture faces in the form of hackles, slickensides, or gouges. These features may facilitate movement in one direction while oppose shear deformation in the other direction due to the saw-tooth structure of irregularities. This direction dependence of the shear compliance of the fracture planes may affect the measured ratio of normal to shear fracture compliance for different locations along the fracture. Furthermore, these effects may contribute to the pressure dependence of fracture compliance, because fracture opening or shear sliding would change the number of asperities in contact and, consequently, affect the ratio of the normal to shear compliance. Here, we use numerical modeling to investigate the change in normal and shear compliance caused by the presence of slickensides. The effect of the hackles' geometry, the friction coefficient between the fracture surfaces, and the offset between the fracture faces will be discussed in this presentation. Our analysis shows that even in the case of low asperity angles or small offsets between the fracture faces, the fracture compliance ratio could be greater than one, in agreement with several field observations available in the literature.

  7. Five-Year Follow-up of a Randomized Clinical Trial of Unilateral Thyroid Lobectomy with or Without Postoperative Levothyroxine Treatment

    Microsoft Academic Search

    Marcin Barczy?ski; Aleksander Konturek; Filip Go?kowski; Alicja Hubalewska-Dydejczyk; Stanis?aw Cicho?; Wojciech Nowak

    2010-01-01

    Background  The aim of this study was to compare the prevalence of recurrent nodular goiter in the contralateral thyroid lobe among patients\\u000a after unilateral thyroid lobectomy for unilateral multinodular goiter (MNG) receiving versus not receiving postoperative prophylactic\\u000a levothyroxine (LT4) treatment.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  From January 2000 through December 2003, 150 consenting patients underwent a unilateral thyroid lobectomy for unilateral MNG\\u000a at our institution. They

  8. Fracture process zone in granite

    USGS Publications Warehouse

    Zang, A.; Wagner, F.C.; Stanchits, S.; Janssen, C.; Dresen, G.

    2000-01-01

    In uniaxial compression tests performed on Aue granite cores (diameter 50 mm, length 100 mm), a steel loading plate was used to induce the formation of a discrete shear fracture. A zone of distributed microcracks surrounds the tip of the propagating fracture. This process zone is imaged by locating acoustic emission events using 12 piezoceramic sensors attached to the samples. Propagation velocity of the process zone is varied by using the rate of acoustic emissions to control the applied axial force. The resulting velocities range from 2 mm/s in displacement-controlled tests to 2 ??m/s in tests controlled by acoustic emission rate. Wave velocities and amplitudes are monitored during fault formation. P waves transmitted through the approaching process zone show a drop in amplitude of 26 dB, and ultrasonic velocities are reduced by 10%. The width of the process zone is ???9 times the grain diameter inferred from acoustic data but is only 2 times the grain size from optical crack inspection. The process zone of fast propagating fractures is wider than for slow ones. The density of microcracks and acoustic emissions increases approaching the main fracture. Shear displacement scales linearly with fracture length. Fault plane solutions from acoustic events show similar orientation of nodal planes on both sides of the shear fracture. The ratio of the process zone width to the fault length in Aue granite ranges from 0.01 to 0.1 inferred from crack data and acoustic emissions, respectively. The fracture surface energy is estimated from microstructure analysis to be ???2 J. A lower bound estimate for the energy dissipated by acoustic events is 0.1 J. Copyright 2000 by the American Geophysical Union.

  9. Memories for emotional autobiographical events following unilateral damage to medial temporal lobe.

    PubMed

    Buchanan, Tony W; Tranel, Daniel; Adolphs, Ralph

    2006-01-01

    Abnormalities of both memory and emotion have been reported in patients with unilateral damage to the anteromedial temporal lobe, probably reflecting the functions of the amygdala and hippocampus in these processes. Emotion and memory are also known to interact: emotional experiences often leave remarkably durable autobiographical memories. To explore this interaction, and to extend prior studies to the domain of autobiographical memory, we investigated the recollection of real-life emotional events in patients with unilateral damage to the anteromedial temporal lobe. Twenty-three patients who had undergone unilateral temporal lobectomy for the treatment of epilepsy (12 left, 11 right) and 20 healthy comparison participants completed an emotional autobiographical memory test. Participants were asked to recollect their five most emotional memories from any time in their lives and then they completed a word-cued autobiographical memory task. Participants dated each memory and gave ratings on scales of pleasantness, intensity, significance, novelty, vividness and frequency of rehearsal. Left temporal lobectomy (LTL) and healthy comparison groups generated similar numbers of pleasant and unpleasant memories, whereas the right temporal lobectomy (RTL) group produced significantly fewer memories of unpleasant events (P < 0.01). When memories were further categorized according to pleasantness and intensity, the RTL group produced significantly fewer unpleasant/high intensity memories than the other groups (P < 0.01). All groups reported more memories from between the ages of 10 and 30 (the so-called autobiographical memory 'bump'). The results demonstrate a positive bias in the recollection of autobiographical memory following right-sided anteromedial temporal damage. This finding is consistent with the notion that the right, but not the left, anteromedial temporal lobe is involved in the retrieval of negatively valenced, high-intensity memories. PMID:16291807

  10. Vibration-induced nystagmus in patients with unilateral peripheral vestibular disorders.

    PubMed

    Xie, Sujiang; Guo, Jia; Wu, Ziming; Qiang, Dongchang; Huang, Jing; Zheng, Yingjuan; Yao, Qin; Chen, Shan; Tian, Dawei

    2013-12-01

    This study was done to clarify the clinical significance of vibration-induced nystagmus (VIN) and to calculate the sensitivity and the specificity of the vibration test. One hundred and twelve patients with unilateral peripheral vestibular disorders and thirty normal subjects were enrolled into this study. However, patients with spontaneous nystagmus were excluded. Vibration stimuli (approximately 100 Hz) were presented to the mastoids and the forehead. Patients and normal subjects also underwent head shaking nystagmus (HSN) test and caloric testing. Among the 112 patients, 91(81 %) showed VIN which were mainly horizontal. VIN was more frequently elicited on the mastoids than on the forehead. In the majority of patients (76 cases), the direction of VIN was toward the healthy side, whereas patients with Meniere's disease (15 cases), showed nystagmus toward the affected side. None of 30 normal subjects showed VIN. Whereas HSN was found in 70 (63 %) patients and 9 (30 %) in normal subjects. Among 112 patients, 10 showed a canal paresis (CP) value of caloric testing less than 25 %, while 32 with a CP value between 25 and 40 %, 48 with a CP value between 40 and 70 %, and 22 with a CP value no less than 70 %. It is notable that with increasing CP value on caloric testing, VIN was more likely to be elicited. So VIN test is a simple, non-invasive and well-tolerated clinical test that indicates unilateral peripheral vestibular dysfunction. VIN test had greater sensitivity and specificity than HSN test in the diagnosis of unilateral peripheral vestibular disorders. PMID:24427594

  11. Bilateral disruption of conditioned responses after unilateral blockade of cerebellar output in the decerebrate ferret.

    PubMed Central

    Ivarsson, M; Svensson, P; Hesslow, G

    1997-01-01

    1. Lesions of the cerebellar cortex can abolish classically conditioned eyeblink responses, but some recovery with retraining has been observed. It has been suggested that the recovered responses are generated by the intact contralateral cerebellar hemisphere. In order to investigate this suggestion, bilaterally acquired conditioned responses were studied after the unilateral blockade of cerebellar output. 2. Decerebrate ferrets were trained with ipsilateral electrical forelimb stimulation (300 ms, 50 Hz, 1 mA) as the conditioned stimulus and bilaterally applied peri-orbital stimulation (40 ms, 50 Hz, 3 mA) as the unconditioned stimulus. The conditioned and unconditioned eyeblink responses were monitored by EMG recordings from the orbicularis oculi muscle. The output from one cerebellar hemisphere was blocked either by injecting small amounts of lignocaine (lidocaine; 0.5-1.0 microliter) into the brachium conjunctivum, or by a restricted mechanical lesion of the brainstem rostral to the cerebellum. 3. As described by previous investigators, the unilateral blockade of cerebellar output abolished ipsilateral conditioned responses. 4. More importantly, such blockade also abolished or strongly depressed contralateral conditioned responses. When mechanical lesions of the brachium conjunctivum were made, contralateral responses, in contrast to ipsilateral responses, recovered within 1-2.5 h. 5. When the unconditioned stimulus was removed on one side, causing extinction of conditioned responses on this side, conditioned responses were temporarily depressed on the trained side as well. 6. Unilateral interruption of cerebellar output had no clear effect on contralateral unconditioned reflex responses. 7. The results demonstrate that one cerebellar hemisphere in ferrets exerts a marked control of contralateral conditioned eyeblink responses, probably via premotor neurones involved specifically in conditioned, and not in unconditioned, responses. PMID:9234206

  12. Bilateral Sensory Abnormalities in Patients with Unilateral Neuropathic Pain; A Quantitative Sensory Testing (QST) Study

    PubMed Central

    Konopka, Karl-Heinz; Harbers, Marten; Houghton, Andrea; Kortekaas, Rudie; van Vliet, Andre; Timmerman, Wia; den Boer, Johan A.; Struys, Michel M.R.F.; van Wijhe, Marten

    2012-01-01

    In patients who experience unilateral chronic pain, abnormal sensory perception at the non-painful side has been reported. Contralateral sensory changes in these patients have been given little attention, possibly because they are regarded as clinically irrelevant. Still, bilateral sensory changes in these patients could become clinically relevant if they challenge the correct identification of their sensory dysfunction in terms of hyperalgesia and allodynia. Therefore, we have used the standardized quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain (DFNS) to investigate somatosensory function at the painful side and the corresponding non-painful side in unilateral neuropathic pain patients using gender- and age-matched healthy volunteers as a reference cohort. Sensory abnormalities were observed across all QST parameters at the painful side, but also, to a lesser extent, at the contralateral, non-painful side. Similar relative distributions regarding sensory loss/gain for non-nociceptive and nociceptive stimuli were found for both sides. Once a sensory abnormality for a QST parameter at the affected side was observed, the prevalence of an abnormality for the same parameter at the non-affected side was as high as 57% (for Pressure Pain Threshold). Our results show that bilateral sensory dysfunction in patients with unilateral neuropathic pain is more rule than exception. Therefore, this phenomenon should be taken into account for appropriate diagnostic evaluation in clinical practice. This is particularly true for mechanical stimuli where the 95% Confidence Interval for the prevalence of sensory abnormalities at the non-painful side ranges between 33% and 50%. PMID:22629414

  13. Left and Right Lung Asynchrony as a Physiological Indicator for Unilateral Bronchial Obstruction in Interventional Bronchoscopy

    PubMed Central

    Mineshita, Masamichi; Kida, Hirotaka; Nishine, Hiroki; Handa, Hiroshi; Inoue, Takeo; Miyazawa, Teruomi

    2014-01-01

    Background In patients with bronchial obstruction, pulmonary function tests may not change significantly after intervention. The airflow asynchrony in both lungs due to unilateral bronchial obstruction may be applicable as a physiological indicator. The airflow asynchrony is reflected by the difference in the left and right lung sound development at tidal breathing. Objectives To investigate the usefulness of left and right lung asynchrony due to unilateral bronchial obstruction as a physiological indicator for interventional bronchoscopy. Methods Fifty cases with central airway obstruction were classified into three groups: tracheal, bronchial and extensive obstruction. The gap index was defined as the absolute value of the average of gaps between the left and right lung sound intensity peaks for a 12-second duration. Results Before interventional bronchoscopy, the gap index was significantly higher in the bronchial (p<0.05) and extensive obstruction groups (p<0.05) than in the tracheal group. The gap index in cases with unilateral bronchial obstruction of at least 80% (0.18±0.04 seconds) was significantly higher than in cases with less than 80% obstruction (0.02±0.01 seconds, p<0.05). After intervention for bronchial obstruction, the dyspnea scale (p<0.001) and gap index significantly improved (p<0.05), although no significant improvements were found in spirometric assessments. The responder rates for dyspnea were 79.3% for gap indexes over 0.06 seconds and 55.6% for gap indexes of 0.06 seconds or under. Conclusions Assessment of left and right lung asynchrony in central airway obstruction with bronchial involvement may provide useful physiological information for interventional bronchoscopy. PMID:25133760

  14. Acute neuronal and vascular changes following unilateral cerebellar pedunculotomy in the neonatal rat

    PubMed Central

    SHERRARD, RACHEL M.; BOWER, ADRIAN J.

    1997-01-01

    During development of the central nervous system (CNS) both deafferentation and axotomy induce increased neuronal death and result in a smaller brain with diminished function at maturity. Unilateral cerebellar pedunculotomy has been used as a model to study the relative importance of these 2 types of lesion on the survival of developing CNS neurons. Within the cerebellum, unilateral pedunculotomy causes deafferentation of the hemicerebellum and axotomy in the efferent pathway from the ipsilateral deep cerebellar nuclei. This results in a smaller hemicerebellum with normal cortical laminae but no extracerebellar outflow. In order to identify the sequence of events which leads to this altered structure and therefore to understand the relative importance of afferent versus target-derived trophic support, unilateral cerebellar pedunculotomy was performed on neonatal rat pups, aged between 1 and 3 days. The cerebella were analysed for histological and vascular changes after survival times of 0, 3, 6, 9, 12, 18, 21, 24 and 48 h. The results show that the effects of axotomy on the deep cerebellar nuclear neurons begin within 3 h of the lesion and apoptotic neuronal degeneration occurs within 48 h. However, the cerebellar cortical neurons continue to undergo normal histological development for at least 48 h after deafferentation. In addition, since ischaemia induces similar effects, a study of the vascular tree was made. The results indicate that the pedunculotomy does not alter the blood supply to the cerebellum, nor induce ischaemia of the cerebellar neurons. From this it may be hypothesised that target-derived trophic support is more crucial for the survival of immature neurons than is the trophic effect of afferent input. PMID:9306195

  15. Pedobarographic Analysis Following Pemberton's Pericapsular Osteotomy for Unilateral Developmental Dysplasia of the Hip: An Observational Study.

    PubMed

    Xu, Chao; Yan, Ya-Bo; Zhao, Xiong; Wen, Xin-Xin; Shang, Lei; Huang, Lu-Yu; Lei, Wei

    2015-06-01

    Successful clinical and radiographic outcomes have been reported in patients with unilateral developmental dysplasia of the hip (DDH) following Pemberton pericapsular osteotomy (PPO). However, residual gait deviations are seen in both the affected and unaffected limbs. To date it is not known whether these deviations result in abnormal plantar pressure in such patients.This study investigated this possibility by performing pedobarographic, clinical, and radiographic examinations after PPO in 20 patients (age: 102.5?±?19.0 months) with unilateral DDH who underwent PPO at 34.2?±?9.8 months of age. Plantar pressure was evaluated using the Footscan pressure plate (RsScan International, Olen, Belgium). Each foot was subdivided into 10 zones and peak pressure, force-time integral as a percentage of total FTI, and contact time as a percentage of total stance time was estimated. The minimum duration of follow-up was 24 months (mean: 68.3?±?20.3 months). The data were compared with 20 age- and weight-matched healthy controls.Despite clinical and radiographic examinations showing satisfactory results according to modified McKay and Severin criteria, significant differences in plantar pressure parameters were identified between the affected limbs, the unaffected limbs, and normal controls. No significant differences were found between patients classified as "excellent or good" and those rated as "fair" according to the modified Severin criteria.Pedobarographic results showed the existence of the residual plantar pressure deviations during walking in patients treated with PPO for unilateral DDH. Longer follow-up will be needed to more fully evaluate the effect of these deviations on gait. PMID:26061319

  16. Unilateral fixation for treatment of occipitocervical instability in children with congenital vertebral anomalies of the craniocervical junction.

    PubMed

    Mazur, Marcus D; Ravindra, Vijay M; Brockmeyer, Douglas L

    2015-04-01

    OBJECT Patients with occipitocervical (OC) instability from congenital vertebral anomalies (CVAs) of the craniocervical junction (CCJ) often have bony abnormalities that make instrumentation placement difficult. Within this patient population, some bilateral instrumentation constructs either fail or are not feasible, and a unilateral construct must be used. The authors describe the surgical management and outcomes of this disorder in patients in whom unilateral fixation constructs were used to treat OC instability. METHODS From a database of OC fusion procedures, the authors identified patients who underwent unilateral fixation for the management of OC instability. Patient characteristics, surgical details, and radiographic outcomes were reviewed. In each patient, CT scans were performed at least 4 months after surgery to evaluate for fusion. RESULTS Eight patients with CVAs of the CCJ underwent unilateral fixation for the treatment of OC instability. For 4 patients, the procedure occurred after a bilateral OC construct failed or infection forced hardware removal. For the remainder, it was the primary procedure. Two patients required reoperation for hardware revision and 1 developed nonunion requiring revision of the bone graft. Ultimately, 7 patients demonstrated osseous fusion on CT scans and 1 had a stable fibrous union. CONCLUSIONS These findings demonstrate that a unilateral OC fixation is effective for the treatment of OC instability in children with CVAs of the CCJ in whom bilateral screw placement fails or is not feasible. PMID:25828503

  17. Influence of dual task constraints on gait performance and bimanual coordination during walking in children with unilateral cerebral palsy.

    PubMed

    Hung, Ya-Ching; Meredith, Geneva S

    2014-04-01

    The purpose of the current study was to evaluate the effects of dual task constraints on walking and bimanual coordination for children with and without unilateral Cerebral Palsy (CP). Ten children with unilateral CP (age 7-11 years; MACS levels I-II) and ten age-matched typically developed children were asked to first stand still while holding a box level (standing condition), second, to walk along a path (baseline condition), and third to walk again while carrying a box steady and level (dual task condition) at a preferred speed. The results showed that children with unilateral CP decreased their walking speed, stride length, step width, and toe clearance from the floor under dual task constraints when compared to the baseline condition (all p's<0.05), however, typically developing children did not change. Children with unilateral CP also had less level box carrying, larger vertical box movement, and larger elbow movements when compared to typically developing children under dual task condition (all p's<0.05). Dual task constraints with a secondary motor task like the current walking with a box task seemed challenging for children with unilateral CP. Therefore, future treatments or assessments should consider using dual task constraints to manipulate the difficulty of tasks. PMID:24529863

  18. Increased Ocular Pulse Amplitude Associated with Unilateral Dysgenesis of the Orbital Roof

    PubMed Central

    Vira, Ami Shah; Mahmoud, Ashraf M.; Roberts, Cynthia J.; Katz, Steven E.

    2015-01-01

    Introduction Two patients (one with neurofibromatosis type 1) presented with unilateral ocular pulsation. Methods A CT scan of the orbits revealed extensive dysgenesis of the orbital roof with herniation of the frontal lobe into the orbit in both cases. PASCAL dynamic contour tonometry was performed. Results The ipsilateral ocular pulse amplitude (OPA) was greater than the contralateral side, and the ocular pulse waveform morphology more closely approximated the known intracranial waveform in these patients. Conclusions We hypothesize that the greater OPA was due to stronger transmission of the intracranial pressure waveform amplitude and morphology in the absence of the orbital roof.

  19. Anesthesia Management of a 20-Month-Old Patient with Giant Unilateral Wilms Tumor

    PubMed Central

    Matinyan, Nune; Saltanov, Alexander; Martynov, Leonid; Kazantsev, Anatolij

    2015-01-01

    Wilms tumour (WT) (or nephroblastoma) is one of the most common malignant kidney tumors in children. On subsequent stages clinically it is often characterized by abdominal hypertension syndrome, which, in turn, leads to development of respiratory insufficiency. Other symptoms comprise renal deficiency, hypertension, and abnormalities of hemostasis and hemogram. Treatment includes rounds of preoperative chemotherapy and subsequent surgery. We report a case of perioperative management for nephrectomy in 20-month-old patient with a giant unilateral WT. The complexity of anesthesia was determined by the size of tumor, increased intra-abdominal pressure, respiratory deficiency, and hypercoagulation. PMID:25815216

  20. Unilateral Axillary Arch and Variations in the Axillary Vein and Intercostal Nerves: A Case Report

    PubMed Central

    Ramanadham, Sharada; Kalthur, Sneha Guruprasad; Pai, Shakunthala R

    2011-01-01

    Knowledge of muscular, vascular, and neural variations in the axilla is of great clinical importance, especially in mastectomies, breast reconstruction, and axillary bypass operations. In the present paper, we report unilateral variations observed in the axillary region of a male cadaver. A fibromuscular axillary arch was observed on the right side. On the same side, there was a bifurcated axillary vein; a medial cutaneous nerve of the arm passed through and later ran beneath this axillary vein. In addition, the intercostobrachial nerve was absent on the right side. The clinical significance of the variations observed and their embryological basis are discussed in this paper. PMID:22135576

  1. Unilateral movement disorder as a presenting sign of paediatric post-varicella angiopathy

    PubMed Central

    Bulder, Marcel M M; Houten, Robert ten; Klijn, Catharina J M; Braun, Kees P J

    2013-01-01

    Diagnosing ischaemic stroke in children is often difficult. Post-varicella angiopathy (PVA) is a well-recognised and frequent cause of childhood ischaemic stroke, particularly affecting the basal ganglia. When a previously healthy child presents with unilateral abnormal involuntary movements, cerebral infarction should be included in the differential diagnosis and PVA should be considered, even when there is no recent history of rash and cerebrospinal fluid is normal. Medical history and intracranial vascular imaging are important for early diagnosis and treatment. PMID:23744858

  2. Unilateral compressive optic neuropathy due to skull hyperostosis secondary to nutritional vitamin A deficiency

    PubMed Central

    Zayed, Mohammed G.; Hickman, Simon J.; Batty, Ruth; McCloskey, Eugene V.; Pepper, Irene M.

    2015-01-01

    Summary We report a 17-year-old boy who presented with a chronic left unilateral optic neuropathy. Computerized tomography and magnetic resonance imaging demonstrated compression of the left optic nerve due to skull hyperostosis. He was found to be profoundly vitamin A deficient secondary to an unusual diet consisting predominantly of potato chips and crisps. Skull hyperostosis with cranial neuropathies and other neurological abnormalities has been described in growing animals fed vitamin A deficient diets but has not been previously reported in humans. PMID:26136803

  3. Microsurgical Anterior Cervical Foraminotomy (Uncoforaminotomy) for Unilateral Radiculopathy: Clinical Results of a new Technique

    Microsoft Academic Search

    W. Saringer; I. Nöbauer; M. Reddy; M. Tschabitscher; A. Horaczek

    2002-01-01

    Summary.\\u000a Summary.  \\u000a ?\\u000a \\u000a \\u000a \\u000a \\u000a Background:   The authors report the clinical application of a new microsurgical technique. The cervical anterior foraminotomy (uncoforaminotomy),\\u000a which is used for the surgical treatment of unilateral cervical radiculopathy secondary to posterolateral disc herniations\\u000a or spondylotic foraminal stenoses.\\u000a \\u000a ?\\u000a \\u000a \\u000a \\u000a \\u000a Method:   Between June 2000 and May 2001, 34 patients (16 men and 18 women with a mean age of

  4. A case of unilateral phthiriasis palpebrarum infestation involving the left eye.

    PubMed

    Ashraf, Mohammad; Waris, Abdul; Kumar, Ashwini; Akhtar, Nahid

    2014-01-01

    Phthiriasis palpebrarum is a rare cause of eyelid infestation. We report a case of unilateral phthiriasis palpebrarum. A 28-year-old man presented with moderate itching associated with lacrimation and irritation in the left eye. The initial evaluation of the patient revealed multiple white dots on the left upper eyelashes. Slit-lamp examination revealed multiple nits attached to the base and shaft of the cilia. There was no hyperaemia or discharge present in the conjunctiva and the cornea was clear and shiny. The right eye was perfectly normal. The patient was treated with moxifloxacin eye ointment and was completely cured in 1 week. PMID:24907211

  5. 'Unilateral cone dystrophy': ERG changes implicate abnormal signaling by hyperpolarizing bipolar and/or horizontal cells.

    PubMed Central

    Sieving, P A

    1994-01-01

    The two cases described here appear to represent the infrequently reported entity of "unilateral cone (cone-rod) dystrophy." Both cases give the suggestion that daylight vision can be affected by abnormalities in visual signals in the proximal retina, after they leave the cone photoreceptors themselves. The ERG waveform changes in these two cases are consistent with a deficit in signaling by the hyperpolarizing bipolar cells, and the complaint of abnormal color perception in both cases presented here raises the possibility that the OFF-pathway through hyperpolarizing bipolar cells may be important for color processing. PMID:7886877

  6. Ventilation-perfusion scintigraphy in an adult with congenital unilateral hyperlucent lung

    SciTech Connect

    Wegener, W.A.; Velchik, M.G. (Hospital of the University of Pennsylvania, Philadelphia (USA))

    1990-10-01

    A variety of congenital and acquired etiologies can give rise to the radiographic finding of a unilateral hyperlucent lung. An unusual case of congenital lobar emphysema diagnosed in a young adult following the initial discovery of a hyperexpanded, hyperlucent lung is reported. Although subsequent bronchoscopy and radiologic studies detailed extensive anatomic abnormalities, functional imaging also played an important role in arriving at this rare diagnosis. In particular, ventilation-perfusion scintigraphy identified the small contralateral lung as the functional lung and helped narrow the differential diagnosis to etiologies involving obstructive airway disorders.

  7. Is the Ecstasy-induced ipsilateral rotation in 6-hydroxydopamine unilaterally lesioned rats dopamine independent?

    Microsoft Academic Search

    H. B. Lebsanft; A. Mayerhofer; K.-A. Kovar; W. J. Schmidt

    2003-01-01

    Summary.   3,4-Methylenedioxymethamphetamine (MDMA) has recently been hypothesized to be effective against the symptoms of Parkinson's\\u000a disease. Therefore we tested the effects of MDMA-derivatives in the rotational behavioural model. Male Sprague Dawley rats\\u000a were lesioned unilaterally with 6-hydroxydopamine at the medial forebrain bundle. MDMA was administered at doses of 2.5, 5.0\\u000a and 10.0?mg\\/kg, its derivatives N-Methyl-1-(1,3-benzodioxol-5-yl)-2-butananamine (MBDB), 3,4-Methylenedioxy-N-ethylamphetamine\\u000a (MDE) and 3,4-Methylenedioxyamphetamine

  8. Ewing's sarcoma of the orbit with intracranial extension: A rare cause of unilateral proptosis

    PubMed Central

    Nair, Anup P.; Bettaswamy, Guruprasad; Jaiswal, Awdhesh K.; Garg, Pallav; Jaiswal, Sushila; Behari, Sanjay

    2011-01-01

    Ewing's sarcoma causing unilateral proptosis along with bifrontal extradural infiltration in a child is an unusual presentation. A female patient presented with features of painless proptosis of the left eye with visual deterioration. Her radiology revealed an infiltrating intraorbital, extraconal tumor with intracranial bifrontal extradural extension causing mass effect. Total excision of the intraorbital and intracranial part of the tumor along with postoperative chemo- and radiotherapy brought about a substantial relief. The clinicoradiological presentation and management of this rare entity are discussed. PMID:21977086

  9. [Unilateral auditory hallucinations due to left temporal lobe ischemia: a case report].

    PubMed

    Anegawa, T; Hara, K; Yamamoto, K; Matsuda, M

    1995-10-01

    Unilateral auditory hallucinations are a rare lateralization phenomenon experienced in one ear or from one direction. We recently encountered a 63-year-old right-handed man who developed transient unilateral auditory hallucinations associated with pure word deafness. The patient had a past history of myocardial infarction, lung cancer and aortic aneurysm, but no previous psychiatric or convulsive disorders. About six months before admission, he developed right hemiparesis and motor aphasia caused by a hemorrhagic left parietal infarct. These symptoms gradually improved over three weeks. Two days before admission, he suddenly lost the ability to understand spoken words. He concurrently experienced auditory hallucinations arising from the right anterior direction. On admission, he was very embarrassed to simple verbal commands. He was unable to comprehend spoken words and repeat speech, although he could fairly follow written commands. Confrontation naming, reading aloud, comprehension, spontaneous writing remained relatively unaffected, although he occasionally made paraphasic errors. He could distinguish environmental sounds such as a telephone ringing or running water. After gradual improvement of his auditory incomprehension, he began to describe auditory hallucinations of verbal, musical and elementary types. He was fully aware of the hallucinatory nature of his experience, and took some notes. Two days before admission, from the right anterior side of his head he heard a familiar radio announcer reporting news about the earthquake in Osaka Prefecture and the recommended places of refuge. After similar experiences over several days, he repetitively heard a familiar Japanese traditional song from the right side, which was followed by elementary auditory hallucinations such as a car engine and a siren. These symptoms spontaneously disappeared after nine days. Besides his auditory hallucinations, visual hallucinations and illusional emotion were temporarily present. The Wechsler adult intelligence scale revealed a verbal IQ of 91 and a performance IQ of 100. Pure tone audiometry revealed bilateral, mild peripheral sensorineural hearing loss. Brainstem auditory evoked potentials were unrevealing. The EEG showed slow activities in the left temporoparietal region. Magnetic resonance imaging of the brain failed to reveal any relevant abnormalities except for an old hemorrhagic parietal infarct. The SPECT with Tc99m-HMPAO, however, showed reduced blood flow in the left temporal lobe including the first temporal convolution as well as in the left parietal lobe. Based on the SPECT findings, unilateral auditory hallucinations in our patient are considered to have resulted from the left temporal lobe ischemia. Our case indicates that unilateral auditory hallucinations may have a clinicoanatomical correlation with contralateral temporal lobe lesions. PMID:8821499

  10. Unilateral twin tubal ectopic pregnancy in a patient following tubal surgery

    PubMed Central

    Ghanbarzadeh, Nahid; Nadjafi-Semnani, Mohammad; Nadjafi-Semnani, Ali; Nadjfai-Semnani, Fatemeh; Shahabinejad, Sima

    2015-01-01

    We report a spontaneous unilateral live tubal twin pregnancy in a patient with a history of previous ectopic pregnancy (EP) and tubal surgery. Transvaginal ultrasound showed one pregnancy sac containing two fetal poles with cardiac activity, which appeared to be sited within the right adnexum. The right tubal EP was removed by salpingectomy. Ultrasound findings of suspected adnexal mass and free liquid in the Douglas pouch along with an increased a beta-human chorionic gonadotrophin levels, especially in association of risk factors, can help the early diagnosis of EP and reduce the related mortality and morbidity. PMID:25983775

  11. “Pathologic” Fractures: Should These Be Included in Epidemiologic Studies of Osteoporotic Fractures?

    PubMed Central

    Curtis, Jeffrey R.; Taylor, Allison J.; Matthews, Robert S.; Ray, Midge; Becker, David J.; Gary, Lisa C.; Kilgore, Meredith L.; Morrisey, Michael A.; Saag, Kenneth G; Warriner, Amy; Delzell, Elizabeth

    2009-01-01

    Introduction Analyses of osteoporosis-related fractures that use administrative data often exclude pathologic fractures (ICD-9 733.1x) due to concern that these are caused by cancer. We examined “pathologic” fractures of the vertebrae and hip to evaluate their contribution to fracture incidence and assessed the evidence for a malignancy. Methods We studied U.S. Medicare beneficiaries age ? 65 with new fractures identified using ICD-9 diagnosis codes 733.13 (pathologic vert), 805.0, 805.2, 805.4, 805.8 (non-pathologic vert); and 733.14 (pathologic hip), 820.0, 820.2 820.8 (non-pathologic hip). We further examined the proportion of cases with a diagnosis of a malignancy proximate to the fracture. Results We identified 44,120 individuals with a vertebral fracture and 60,354 with a hip fracture. Approximately 50% of vertebral fractures and 3% of hip fractures were coded as pathologic. For only approximately 25% of persons with a “pathologic” vertebral fracture ICD-9 code, but 66% of persons with a “pathologic” hip fracture, there was evidence of a possible cancer diagnosis. Conclusion Among U.S. Medicare beneficiaries, one-fourth of pathologic vertebral fracture and two-thirds of pathologic hip fracture cases had evidence for a malignancy. Particularly for vertebral fractures, excluding persons with pathologic fractures in epidemiologic analyses that utilize administrative claims data substantially underestimates the burden of fractures due to osteoporosis. PMID:19184268

  12. Fracture and Medium Modeling, by Analizing Hidraulic Fracturing Induced Microseismicity

    NASA Astrophysics Data System (ADS)

    Gomez Alba, S.; Vargas Jiménez, C. A.

    2014-12-01

    Hydraulic fracturing is an essential technology for most unconventional hydrocarbon resources and many conventional ones as well. The primary limitation on the improvement and optimization of the fracturing process is the minimal access to observe the behavior of the fracture in the subsurface. Without direct observational evidence, hypothetical mechanisms must be assumed and then tested for their validity with indirect information such as wellbore measurements, indirect production and pressure behavior. One of the most important sources of information today is the relation made between micro seismic source mechanisms and fracture behavior. Hydraulic fractures induce some level of micro seismicity when the stress conditions in the Earth are altered by changes in stress during the operations. The result is the sudden movement between rock elements and the radiation of both compressional and shear energy in a seismic range that can be detected and recorded with sensitive receivers. The objective of this work is to provide reasonable information when applying inversion methods in order to estimate the vertical and horizontal spatial heterogeneities in medium and energy radiation distribution of microseisms while fracking operations. The method consist in record microseisms at a previous lineal array of stations (triaxial accelerometers) which are located close to the source coordinates and cover the area of study. The analysis clarify some ideas about what information can be gained from the micro seismic source data and according to the obtained results, what kind of comparisons and associations might be done to evaluate the fracking performance operation. Non uniformities in medium such as faults would be revealed by interpreted scattering coefficients. Fracture properties like distance, velocity and orientation would be also determined by analyzing energy radiation.

  13. Locating hydraulically active fracture planes

    SciTech Connect

    Malzahn, Mark; Dreesen, Donald; Fehler, Michael

    1988-01-01

    If analysis of the microseismicity accompanying fluid injections is to be of maximum use in predicting hot dry rock (HDR) reservoir performance, it should lead to the determination of both the rock volume and active flowing surface area of the reservoir. In the granitic rock at the HDR geothermal site at Fenton Hill, New Mexico, the micro-earthquakes located during hydraulic fracturing occur in large three-dimensional volumes called seismic clouds. Cores cut from the region prior to fracturing show numerous planar fractures, some mineral-filled, at virtually random orientations. Evidence supports the hypothesis that only a few of these planes make up the flow path between wells for most of the injected fluid. If this is indeed the case, then it is necessary to be able to distinguish between fractures that accept flow from those which do not. We accomplish this by defining “flow-probable” planes to be those which have seismicity located relatively farther away from lines where other planes intersect. We show that these flow probable planes intercept wellbores at locations where other data confirm the presence of hydraulically active fractures.

  14. Falls, fractures, and hip pads.

    PubMed

    Sinaki, Mehrsheed

    2004-12-01

    Improvement of balance along with bone-enhancing pharmacotherapy can improve the level of an individual's physical activity and mobility. Balance can be improved with enhancement of postural proprioception and muscular strength. Postural deformities have been shown to impair quality of life of osteoporotic individuals. Kyphotic posture has been demonstrated to contribute to propensity to fall in osteoporotic individuals. Kyphotic posturing and gait disorders can be managed through proprioceptive training, use of a weighted kypho-orthosis, muscle re-education, and safe resistance exercises. Proprioceptive balance training can reduce falls and fracture. Sarcopenia and osteoporotic fractures create musculoskeletal challenges that cannot be met with pharmacotherapy alone. Bone loss, imbalance, and gait disorder along with cognitive concerns can increase with aging. Even in healthy persons, predisposition to falls increases with age-related neuromuscular changes. Muscle strength decreases approximately 50% from age 30 to 80. Furthermore, the amount of body sway increases with reduction of proprioception. Therefore, measures that can decrease imbalance can reduce the risk for falls and fracture. In normal balance, ankle strategies are recruited rather than hip strategies. Strengthening of the lower extremity muscles reduces the risk for falls. Gait aids can also decrease the risk for falls. During a fall, the risk for hip fracture increases 30-fold if there is direct impact to the hip. The use of hip protectors can decrease the risk for hip fracture during a sideways fall. Training in effective safe-landing strategies should be included in fall prevention programs. PMID:16036094

  15. Gel placement in fractured systems

    SciTech Connect

    Seright, R.S. [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States)

    1995-11-01

    This paper examines several factors that can have an important effect on gel placement in fractured systems, including gelant viscosity, degree of gelation, and gravity. For an effective gel treatment, the conductivity of the fracture must be reduced and a viable flow path must remain open between the wellbore and mobile oil in the reservoir. During placement, the gelant that``leaks off`` from the fracture into the rock plays an important role in determining how well a gel treatment will reduce channeling. For a given volume of gelant injected the distance of gelant leakoff is greater for a viscous gelant than for a low-viscosity gelant. In one method to minimize gelant leakoff, sufficient gelation is designed to occur before the gelant leaves the wellbore. The authors investigated this approach in numerous experiments with both fractured and unfractured cores. They studied Cr(III)/acetate/hydrolyzed polyacrylamide (HPAM), resorcinol/formaldehyde, Cr(III)/xanthan, aluminum/citrate/HPAM, and other gelants and gels with various delay times between gelant preparation and injection. Their results suggest both hope and caution concerning the injection of gels into fractured systems.

  16. Evaluation and Effect of Fracturing Fluids on Fracture Conductivity in Tight Gas Reservoirs Using Dynamic Fracture Conductivity Test 

    E-print Network

    Correa Castro, Juan

    2011-08-08

    of “dynamical fracture conductivity test”, were carried out. This procedure simulates the proppant/frac fluid slurries flow into the fractures in a low-permeability rock, as it occurs in the field, using different combinations of polymer and breaker...

  17. Evaluation and Effect of Fracturing Fluids on Fracture Conductivity in Tight Gas Reservoirs Using Dynamic Fracture Conductivity Test

    E-print Network

    Correa Castro, Juan

    2011-08-08

    of “dynamical fracture conductivity test”, were carried out. This procedure simulates the proppant/frac fluid slurries flow into the fractures in a low-permeability rock, as it occurs in the field, using different combinations of polymer and breaker...

  18. The Performance of Fractured Horizontal Well in Tight Gas Reservoir 

    E-print Network

    Lin, Jiajing

    2012-02-14

    of semi-analytical response of a rectilinear reservoir with closed outer boundaries. A statistically assigned fracture network is used in the study to represent natural fractures based on the spacing between fractures and fracture geometry. The multiple...

  19. A PKN Hydraulic Fracture Model Study and Formation Permeability Determination 

    E-print Network

    Xiang, Jing

    2012-02-14

    and unconventional hydraulic fracturing operations, fracturing during water-flooding of petroleum reservoirs, shale gas, and injection/extraction operation in a geothermal reservoir. Designing a hydraulic fracturing job requires an understanding of fracture growth...

  20. Incidence of fractures requiring inpatient care

    PubMed Central

    Somersalo, Axel; Kautiainen, Hannu; Lönnroos, Eija; Heinänen, Mikko; Kiviranta, Ilkka

    2014-01-01

    Background The overall incidence of fractures has been addressed in several studies, but there are few data on different types of fractures that require inpatient care, even though they account for considerable healthcare costs. We determined the incidence of limb and spine fractures that required hospitalization in people aged ? 16 years. Patients and methods We collected data on the diagnosis (ICD10 code), procedure code (NOMESCO), and 9 additional characteristics of patients admitted to the trauma ward of Central Finland Hospital between 2002 and 2008. Incidence rates were calculated for all fractures using data on the population at risk. Results and interpretation During the study period, 3,277 women and 2,708 men sustained 3,750 and 3,030 fractures, respectively. The incidence of all fractures was 4.9 per 103 person years (95% CI: 4.8–5.0). The corresponding numbers for women and men were 5.3 (5.1–5.4) and 4.5 (4.3–4.6). Fractures of the hip, ankle, wrist, spine, and proximal humerus comprised two-thirds of all fractures requiring hospitalization. The proportion of ankle fractures (17%) and wrist fractures (9%) was equal to that of hip fractures (27%). Four-fifths of the hospitalized fracture patients were operated. In individuals aged < 60 years, fractures requiring hospitalization were twice as common in men as in women. In individuals ? 60 years of age, the opposite was true. PMID:24694275

  1. Nonplanar fracture propagation from a horizontal wellbore: Experimental study

    SciTech Connect

    Abass, H.H.; Hedayati, S.; Meadows, D.L.

    1996-08-01

    This paper presents experimental results related to hydraulic fracturing of a horizontal well, specifically the nonplanar fracture geometries resulting from fracture initiation and propagation. Experiments were designed to investigate nonplanar fracture geometries. This paper discusses how these nonplanar fractures can be responsible for premature screenout and excessive treatment pressure when a horizontal well is hydraulically fractured. Reasons for unsuccessful hydraulic fracturing treatments of a horizontal well are presented and recommendations to ensure clear communication channels between the wellbore and the fracture are given.

  2. Rio Blanco massive hydraulic fracture

    SciTech Connect

    Not Available

    1973-01-01

    The Piceance Basin in Colorado contains an estimated 600 trillion cu ft of natural gas in place. Both the Rulison and Rio Blanco events have been detonated to determine the feasibility of nuclear fracturing to stimulate natural gas production in this basin. A demonstration program to test the relative effectiveness of massive hydraulic fracturing (MHF) to achieve natural gas production stimulation from the same gas reservoir is presented. Details are included on MHF design parameters, including surface and subsurface equipment, pumping requirements, evaluation of fracturing results, and all associated test programs; site characteristics and preparation; proposal for gas utilization program; environmental surveillance and comparative analysis of environmental aspects of MHF and nuclear stimulation; gas delivery estimates; project administration; and costs and scheduling.

  3. Capillary fracturing in granular media.

    PubMed

    Holtzman, Ran; Szulczewski, Michael L; Juanes, Ruben

    2012-06-29

    We study the displacement of immiscible fluids in deformable, noncohesive granular media. Experimentally, we inject air into a thin bed of water-saturated glass beads and observe the invasion morphology. The control parameters are the injection rate, the bead size, and the confining stress. We identify three invasion regimes: capillary fingering, viscous fingering, and "capillary fracturing," where capillary forces overcome frictional resistance and induce the opening of conduits. We derive two dimensionless numbers that govern the transition among the different regimes: a modified capillary number and a fracturing number. The experiments and analysis predict the emergence of fracturing in fine-grained media under low confining stress, a phenomenon that likely plays a fundamental role in many natural processes such as primary oil migration, methane venting from lake sediments, and the formation of desiccation cracks. PMID:23004989

  4. Capillary Fracturing in Granular Media

    NASA Astrophysics Data System (ADS)

    Holtzman, Ran; Szulczewski, Michael L.; Juanes, Ruben

    2012-06-01

    We study the displacement of immiscible fluids in deformable, noncohesive granular media. Experimentally, we inject air into a thin bed of water-saturated glass beads and observe the invasion morphology. The control parameters are the injection rate, the bead size, and the confining stress. We identify three invasion regimes: capillary fingering, viscous fingering, and “capillary fracturing,” where capillary forces overcome frictional resistance and induce the opening of conduits. We derive two dimensionless numbers that govern the transition among the different regimes: a modified capillary number and a fracturing number. The experiments and analysis predict the emergence of fracturing in fine-grained media under low confining stress, a phenomenon that likely plays a fundamental role in many natural processes such as primary oil migration, methane venting from lake sediments, and the formation of desiccation cracks.

  5. Fracture surfaces of irradiated composites

    NASA Technical Reports Server (NTRS)

    Milkovich, Scott M.; Sykes, George F., Jr.; Herakovich, Carl T.

    1987-01-01

    Electron microscopy was used to analyze the fracture surfaces of T300/934 graphite/epoxy unidirectional off-axis tensile coupons which were subjected to 1.0-MeV electron radiation at a rate of 50 Mrad/h for a total dose of 10 Grad. Fracture surfaces from irradiated and nonirradiated specimens tested at 116 K, room temperature, and 394 K were analyzed to assess the influence of radiation and temperature on the mode of failure and variations in constituent material as a function of environmental exposure. Micrographs of fracture surfaces indicate that irradiated specimens are more brittle than nonirradiated specimens at low temperatures. However, at elevated temperatures the irradiated specimens exhibit significantly more plasticity than nonirradiated specimens.

  6. Fracture mechanics of cellular glass

    NASA Technical Reports Server (NTRS)

    Zwissler, J. G.; Adams, M. A.

    1981-01-01

    The fracture mechanics of cellular glasses (for the structural substrate of mirrored glass for solr concentrator reflecting panels) are discussed. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials were developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region 1 may be slower, by orders of magnitude, than that found in dense glasses.

  7. Hydraulic fracturing process and compositions

    SciTech Connect

    Constien, V. G.; King, M. T.

    1985-09-17

    Improved fracturing processes are described which use novel aqueous hydraulic fracturing fluids. The fluids comprise: (a) an aqueous medium, and (b) a thickening amount of a thickener composition comprising (i) a water-soluble or water-dispersible interpolymer having pendant hydrophobic groups chemically bonded thereto, (ii) a nonionic surfactant having a hydrophobic group(s) that is capable of associating with the hydrophobic groups on said organic polymer, and (iii) a water-soluble electrolyte. Additionally, the fluids preferably contain a stabilizing amount of a thiosulfate salt. As an example, an interpolymer of acrylamide and dodecyl acrylate was used in combination with a nonionic surfactant (HLB of about 10 to about 14) to thicken a dilute aqueous solution of KCl and sodium thiosulfate; the aqueous solution had excellent properties for use as a high temperature hydraulic fracturing fluid.

  8. Fracture problems in composite materials

    NASA Technical Reports Server (NTRS)

    Erdogan, F.

    1972-01-01

    A series of fracture problems in composite materials are identified, their methods of solution are briefly discussed, and some sample results are presented. The main problem of interest is the determination of the stress state in the neighborhood of localized imperfections such as cracks and inclusions which may exist in the composite. Particular emphasis is placed on the evaluation of quantities such as the stress intensity factors, the power of the stress singularity, and the strain energy release rate, which may be used directly or indirectly in connection with an appropriate fracture criterion for the prediction of fracture initiation and propagation load levels. The topics discussed include a crack in layered composites, a crack terminating at and going through a bi-material interface, a penny-shaped crack in a filament-reinforced elastic matrix, and inclusion problems in bonded materials.

  9. Numerical Modeling of Fracture Permeability Change in Naturally Fractured Reservoirs Using a Fully Coupled Displacement Discontinuity Method. 

    E-print Network

    Tao, Qingfeng

    2010-07-14

    an increase in effective stress in naturally fractured reservoirs. The change of effective stress induces fracture deformation and changes fracture aperture and permeability, which in turn influences the production. Coupled interactions exist in the fractured...

  10. Acoustic Character Of Hydraulic Fractures In Granite

    E-print Network

    Paillet, Frederick I.

    1983-01-01

    Hydraulic fractures in homogeneous granitic rocks were logged with conventional acoustic-transit-time, acoustic-waveform, and acoustic-televiewer logging systems. Fractured intervals ranged in depth from 45 to 570m. and ...

  11. Oblique angled view for coracoid fractures

    SciTech Connect

    Goldberg, R.P.; Vicks, B.

    1983-02-01

    In cases of shoulder injury when clinical signs suggest a possible coracoid fracture, a 20 degree posterior oblique film with 20 degrees of cephalad angulation has been shown to demonstrate coracoid fractures when other views have been inconclusive.

  12. Capillary fracture of soft gels.

    PubMed

    Bostwick, Joshua B; Daniels, Karen E

    2013-10-01

    A liquid droplet resting on a soft gel substrate can deform that substrate to the point of material failure, whereby fractures develop on the gel surface that propagate outwards from the contact line in a starburst pattern. In this paper, we characterize (i) the initiation process, in which the number of arms in the starburst is controlled by the ratio of the surface tension contrast to the gel's elastic modulus, and (ii) the propagation dynamics showing that once fractures are initiated they propagate with a universal power law L[proportional]t(3/4). We develop a model for crack initiation by treating the gel as a linear elastic solid and computing the deformations within the substrate from the liquid-solid wetting forces. The elastic solution shows that both the location and the magnitude of the wetting forces are critical in providing a quantitative prediction for the number of fractures and, hence, an interpretation of the initiation of capillary fractures. This solution also reveals that the depth of the gel is an important factor in the fracture process, as it can help mitigate large surface tractions; this finding is confirmed with experiments. We then develop a model for crack propagation by considering the transport of an inviscid fluid into the fracture tip of an incompressible material and find that a simple energy-conservation argument can explain the observed material-independent power law. We compare predictions for both linear elastic and neo-Hookean solids, finding that the latter better explains the observed exponent. PMID:24229192

  13. Intense fracturing and fracture sealing induced by mineral growth in porous rocks Catherine Noiriel a

    E-print Network

    Intense fracturing and fracture sealing induced by mineral growth in porous rocks Catherine Noiriel 2009 Editor: J. Fein Keywords: Force of crystallization Crystallization pressure Fracture sealing Salt look on the way fractures may develop and seal in natural systems. Cylindrical core samples of porous

  14. Contaminant transport in fractured porous media: Analytical solutions for a system of parallel fractures

    Microsoft Academic Search

    E. A. Sudicky; E. O. Frind

    1982-01-01

    An exact analytical solution is developed for the problem of transient contaminant transport in discrete parallel fractures situated in a porous rock matrix. The solution takes into account advective transport in the fractures, molecular diffusion and mechanical dispersion along the fracture axes, molecular diffusion from the fracture to the porous matrix, adsorption onto the face of the matrix, adsorption within

  15. Fracture Toughness and Fracture Roughness Interrelationship in Thermally treated Westerly Granite

    Microsoft Academic Search

    M. H. B. Nasseri; B. S. A. Tatone; G. Grasselli; R. P. Young

    2009-01-01

    This paper presents an experimental work aimed at assessing the correlation between fracture toughness ( K IC ) and fracture roughness for a series of Westerly granite specimens thermally treated up to 850°C. Mode I fracture toughness as a function of thermal treatment is determined using Cracked Chevron Notched Brazilian Disc specimens. The degree of roughness of the resultant fracture

  16. Surrogate-based optimization of hydraulic fracturing in pre-existing fracture networks

    E-print Network

    Lu, Zhiming

    Surrogate-based optimization of hydraulic fracturing in pre-existing fracture networks Mingjie Chen Keywords: Hydraulic fracturing Fractal dimension Surrogate model Optimization Global sensitivity a b s t r a c t Hydraulic fracturing has been used widely to stimulate production of oil, natural gas

  17. Measuring Changes in Fracture Aperture During Injection to Estimate Characteristics of Fractured Rock Near a Well

    Microsoft Academic Search

    T. Schweisinger; L. Murdoch

    2002-01-01

    Fracture networks are critical to ground water flow, but details of the geometry of networks in the subsurface can be difficult to determine with currently available technology. Sheet fractures, or other flat-lying fractures, are an important component of fracture networks in crystalline rock. Using a televiewer, or other borehole geophysical technique, it is possible to determine the depth a sheet

  18. Individuals who sustain nonosteoporotic fractures continue to also sustain fragility fractures

    Microsoft Academic Search

    Magnus K. Karlsson; Ralph Hasserius; Karl J. Obrant

    1993-01-01

    Summary This retrospective case control study was done in order to investigate whether patients who sustain a “nonosteoporotic fracture” early in life also continue to sustain fragility fractures later in life. All patients who had been treated at the Department of Orthopedics in Malmo with a tibial shaft fracture from 1949 to 1963 (n = 767) or an ankle fracture

  19. Prospective Study on Retinal Nerve Fibre Layer Thickness Changes in Isolated Unilateral Retrobulbar Optic Neuritis

    PubMed Central

    Yau, Gordon S. K.; Lee, Jacky W. Y.; Lau, Patrick P. K.; Tam, Victor T. Y.; Wong, Winnie W. Y.; Yuen, Can Y. F.

    2013-01-01

    Purpose. To investigate the retinal nerve fibre layer (RNFL) thickness after unilateral acute optic neuritis using optical coherence tomography (OCT). Patients and Methods. This prospective cohort study recruited consecutive patients with a first episode of isolated, unilateral acute optic neuritis. RNFL thickness and visual acuity (VA) of the attack and normal fellow eye were measured at presentation and 3 months in both the treatment and nontreatment groups. Results. 11 subjects received systemic steroids and 9 were treated conservatively. The baseline RNFL thickness was similar in the attack and fellow eye (P ? 0.4). At 3 months, the attack eye had a thinner temporal (P = 0.02) and average (P = 0.05) RNFL compared to the fellow eye. At 3 months, the attack eye had significant RNFL thinning in the 4 quadrants and average thickness (P ? 0.0002) compared to baseline. The RNFL thickness between the treatment and nontreatment groups was similar at baseline and 3 months (P ? 0.1). Treatment offered better VA at 3 months (0.1 ± 0.2 versus 0.3 ± 0.2 LogMAR, P = 0.04). Conclusion. Generalized RNFL thinning occurred at 3 months after a first episode of acute optic neuritis most significantly in the temporal quadrant and average thickness. Visual improvement with treatment was independent of RNFL thickness. PMID:24459442

  20. Unilateral deafness in children affects development of multi-modal modulation and default mode networks

    PubMed Central

    Schmithorst, Vincent J.; Plante, Elena; Holland, Scott

    2014-01-01

    Monaural auditory input due to congenital or acquired unilateral hearing loss (UHL) may have neurobiological effects on the developing brain. Using functional magnetic resonance imaging (fMRI), we investigated the effect of UHL on the development of functional brain networks used for cross-modal processing. Children ages 7–12 with moderate or greater unilateral hearing loss of sensorineural origin (UHL-SN; N = 21) and normal-hearing controls (N = 23) performed an fMRI-compatible adaptation of the Token Test involving listening to a sentence such as “touched the small green circle and the large blue square” and simultaneously viewing an arrow touching colored shapes on a video. Children with right or severe-to-profound UHL-SN displayed smaller activation in a region encompassing the right inferior temporal, middle temporal, and middle occipital gyrus (BA 19/37/39), evidencing differences due to monaural hearing in cross-modal modulation of the visual processing pathway. Children with UHL-SN displayed increased activation in the left posterior superior temporal gyrus, likely the result either of more effortful low-level processing of auditory stimuli or differences in cross-modal modulation of the auditory processing pathway. Additionally, children with UHL-SN displayed reduced deactivation of anterior and posterior regions of the default mode network. Results suggest that monaural hearing affects the development of brain networks related to cross-modal sensory processing and the regulation of the default network during processing of spoken language. PMID:24723873