[Application of temporomandibular joint dics reduction in the operation of condylar sagittal fracture].

Science.gov (United States)

Wenli, Zeng; Wuchao, Zhou; Jingkun, Zhang; Yisen, Shao; Weihong, Xi

2017-10-01

To explore the selection of temporomandibular joint (TMJ) disc reduction and fixation methods in condylar sagittal fracture surgery. A total of 36 patients with condylar fractures were chosen. The follow-up period was more 6 months. All 36 cases of condylar sagittal fracture were fixed with long screw. In the operation, the displaced joint disc was repositioned and fixed. The fixed method included direct suture (22 cases) and anchorage (14 cases). Clinical followups were performed before surgery and 1 month, 3 months, 6 months and 1 year after surgery. Clinicians recorded data related to the Fricton craniomandibular index (CMI) and evaluated the postoperative joint function during followup before surgery and 6 months after surgery. In both groups, function of TMJ significantly improved after surgery. The CMI decreased from 0.213±0.162 and 0.273±0.154 to 0.059±0.072 and 0.064±0.068 (P0.05) before or after surgery. Both methods could effectively improve the dysfunction of the TMJ caused by trauma. The selection of joint disc reduction and fixation methods is based on the displacement and damage degree of the joint disc.

A distal femoral supra-condylar plate: biomechanical comparison with condylar plate and first clinical application for treatment of supracondylar fracture.

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Liang, Bowei; Ding, Zhenqi; Shen, Junguo; Zhai, Wenliang; Kang, Liangqi; Zhou, Liang; Sha, Mo; Liang, Dongzhu

2012-08-01

An anatomical supra-condylar plate is designed and analysed by biomechanical testing. The biomechanical properties of the supra-condylar and condylar plate were compared in six matched pairs of cadaveric femurs. A transverse osteotomy gap was created to simulate an OTA/AO type A3 supracondylar fracture. The left and right specimens were fitted with supra-condylar and condylar plate, respectively. Nondestructive axial compression, three-point bending and torsion tests were performed, and the peak load of the bone-implant construction was measured. The fracture site suitable for supra-condylar plate application and its correlation with femoral length were calculated. The gender influence on it was also discussed. The difference of stiffness between the supra-condylar and condyle groups were not significant (P > 0.05) at 363.4 and 362.5 N/mm for compression, 229.5 and 237.6 N/mm in the sagittal plane and 195.5 and 188.4 N/mm in the coronal plane for three-point bending, and 7.5 and 7.9 Nm/deg for axial torsion, respectively. The peak load was 4438 ± 136.15 N and 5215 ± 174.33 N, respectively, for the two groups. The average extent of the fracture site suitable for the application of the supra-condylar plate was 70.86 ± 4.61 mm. The femoral length and gender showed no influence on it. Despite the limited bone contact area provided by the supra-condylar plate, its construct stiffness is comparable to the condylar plate. The supra-condylar plate can be used to treat carefully-selected extra-articular supracondylar fractures.

Comparison of cutout resistance of dynamic condylar screw and proximal femoral nail in reverse oblique trochanteric fractures: A biomechanical study

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Gursimrat Singh Cheema

2012-01-01

Results: The bending moment of the PFN group was approximately 50% less than that of the DCS group (P<0.0001. The PFN group resisted more number of cycles than the DCS group (P=0.03 and showed lesser number of component failures as compared with the DCS group (P=0.003. Conclusions: The PFN is biomechanically superior to DCS for the fixation of reverse oblique trochanteric fractures of femur.

Unilateral Condylar Hyperplasia of the Mandible

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Malachovsky I

2015-12-01

Full Text Available Condylar hyperplasia (CH of the mandible is a rare pathology that occurs at the head of the condyle and can lead to facial asymmetry affecting occlusion and possible association with pain and dysfunction. Unilateral condylar hyperplasia is an uncommon condition of unknown aetiology, proper diagnosis of which has to be established, as the patients may look for surgical help. A rare case of unilateral condylar hyperplasia of the mandible is reported here.

Treatment of Pediatric Condylar Fractures: A 20-Year Experience.

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Ghasemzadeh, Ali; Mundinger, Gerhard S; Swanson, Edward W; Utria, Alan F; Dorafshar, Amir H

2015-12-01

The purpose of this study was to define patterns of injury and treatment for condylar and subcondylar fractures and evaluate short-term outcomes in the pediatric population. A retrospective chart review was performed on pediatric patients with mandibular condylar fractures who presented between 1990 and 2010. Computed tomographic imaging was reviewed for all patients to assess fracture characteristics. Mandibular fractures were codified using the Strasbourg Osteosynthesis Research Group and Lindahl classification methods. Sixty-four patients with 92 condylar fractures were identified. Of these patients, 29 had isolated condylar fracture and 35 had a condylar fracture associated with an additional mandibular arch fracture. The most common fracture patterns were diacapitular fracture in the Strasbourg Osteosynthesis Research Group system (n = 46) and vertical condylar head fracture in the Lindahl system (n = 14). Condylar fracture with additional mandibular arch fractures were treated with maxillomandibular fixation more often than patients with condylar fracture [n = 40 (74.1 percent) versus n = 14 (25.9 percent); p = 0.004]. No condylar fracture was treated in an open fashion. Forty-three patients returned for follow-up. The median follow-up period was 81 days (interquartile range, 35 to 294 days). Ten patients had complications (23.3 percent). The most common complication was malocclusion (n = 5). Nine of 10 patients with complications had condylar fracture with an additional mandibular arch fracture. Closed treatment of condylar fractures yields satisfactory results in pediatric patients. Pediatric patients with condylar fractures combined with additional arch fractures experience a higher rate of unfavorable outcomes.

Mandibular condylar morphology for bruxers with different grinding patterns.

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Tao, Jianxiang; Wu, Junhua; Zhang, Xuying

2016-07-01

The purpose of this study was to investigate the mandibular condylar morphology for bruxers with different grinding patterns. Condylar sectional morphology and condylar position of 30 subjects were determined by two viewers using cone beam computed tomography (CBCT) image data sets. The grinding patterns during sleep bruxism (SB) were determined objectively using a Brux-checker device.Chi-square tests were used for statistical analysis for the condylar morphology type between different tooth grinding patterns. Spearman's rank correlation coefficient was used for correlation analysis between condylar position and the canine guidance area during SB. Theincidence of condylarmorphologicaldivergence from idealwas35%.There isa significant difference in distribution of condylar morphology type between the group grinding (GG) and GG combined with mediotrusive side grinding (MG) (p < 0.05). There was no significant correlation between condylar position and canine guidance area during bruxism. MG during SB is associated with condylar morphology that is considered not to be ideal.

The normal range of condylar movement

International Nuclear Information System (INIS)

Choe, Han Up; Park, Tae Won

1978-01-01

The purpose of this study was to investigate the normal range of condylar movement of normal adults. The author gas observed roentgenographic images of four serial positions of condylar head taken by modified transcranial lateral oblique projection. The serial positions are centric occlusion, rest position, 1 inch open position and maximal open position. The results were obtained as follow; 1. Inter-incisal distance was 46.85 mm in maximal open position. 2. The length between the deepest point of glenoid fossa and summit of condylar head in rest position was wider than that in centric occlusion by 0.8 mm. 3. In 1 inch open position, condylar head moved forward from the standard line in 12.64 mm of horizontal direction and moved downwards from the standard line in 1.84 mm of vertical direction. 4. In maximal open position, condylar head moved forward from the standard line in 19.06 mm of horizontal direction and moved downwards from the standard line in 0.4 mm of vertical direction. 5. In centric occlusion, the width between glenoid fossa and margin of condylar head was greater in the posterior portion than in the anterior portion by 0.4 mm. 6. Except for estimated figures of 1 inch open position, all of the estimated figures was greater in male than in female.

Evaluation of Mandibular Condylar Changes in Patients Following ...

African Journals Online (AJOL)

Background: Condylar resorption as a cause of relapse after orthognathic surgery is well known. Several authors have presented evidence of the relation between orthognathic surgery and condylar remodeling and resorption. This study was done to appraise the condylar changes along with the form and function following ...

The Gothic arch (needle point) tracing and condylar inclination.

Science.gov (United States)

el-Gheriani, A S; Winstanley, R B

1987-11-01

The records of 11 patients referred for treatment of TMJ disorders were used to compare condylar inclination found by drawing a tangent and by using a mathematic technique. Needle point tracing angles were also measured for the same patients and were compared with the condylar inclination. It can be concluded that (1) the mathematic technique outlined records a more accurate condylar angulation, and (2) there is a great variation in condylar inclination values between patients and between left and right sides of the same patient, and (3) there is no direct relationship between condylar inclination and the needle point tracing angle.

Update on mandibular condylar fracture management.

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Weiss, Joshua P; Sawhney, Raja

2016-08-01

Fractures of the mandibular condyle have provided a lasting source of controversy in the field of facial trauma. Concerns regarding facial nerve injury as well as reasonable functional outcomes with closed management led to a reluctance to treat with an open operative intervention. This article reviews how incorporating new technologies and surgical methods have changed the treatment paradigm. Multiple large studies and meta-analyses continue to demonstrate superior outcomes for condylar fractures when managed surgically. Innovations, including endoscopic techniques, three-dimensional miniplates, and angled drills provide increased options in the treatment of condylar fractures. The literature on pediatric condylar fractures is limited and continues to favor a more conservative approach. There continues to be mounting evidence in radiographic, quality of life, and functional outcome studies to support open reduction with internal fixation for the treatment of condylar fractures in patients with malocclusion, significant displacement, or dislocation of the temporomandibular joint. The utilization of three-dimensional trapezoidal miniplates has shown improved outcomes and theoretically enhanced biomechanical properties when compared with traditional fixation with single or double miniplates. Endoscopic-assisted techniques can decrease surgical morbidity, but are technically challenging, require skilled assistants, and utilize specialized equipment.

[Intramedullary nailing combined with cannulated screw in treating femoral condyles fractures].

Science.gov (United States)

Shen, Guo-Qing; Zhang, Hao; Long, Da-Fu; Li, Zheng-Wen; Tan, Ying-Dong

2017-07-25

To observe the clinical effects of retrograde intramedullary nailing and cannulated screws in the treatment of femoral condylar fracture. From June 2009 to June 2015, 13 patients with femoral condyles fracture were treated by retrograde intramedullary nailing and cannulated screws including 6 males and 7 females with an average age of 46.1 years old ranging from 16 to 76 years old. There were 10 cases of closed fractures, 3 cases of open fraetures. According to AO classification criteriam, 4 cases were type C1, 7 cases were type C2, 2 cases were type C3. Postoperative reduction of fracture and the knee joint function recovery were observed. All patients were followed up for 12 to 36 months with a mean of 24 months. X-ray examination showed that the union time of fracture was 18 to 24 weeks, 21 weeks on average. There were no cases of loosening, breakage of internal fixators and re-fracture. Hospital for Special Surgery(HSS) knee score was 90.07±4.99 at 1 year after the operation. The clinical efficacy for retrograde intramedullary nailing and cannulated screw for the treatment of femoral condyles fracture was excellent. It can improve the anatomical reattachment rate and reduce the complications and promote the knee functional recovery.

Temporomandibular Joint Idiopathic Condylar Resorptions – A CBCT based case-control study

DEFF Research Database (Denmark)

Kristensen, Kasper Dahl; Schmidt, Bjarke Hjalting; Stoustrup, Peter Bangsgaard

Aim: To describe condylar deformation in the temporomandibular joint (TMJ) in subjects with idiopathic condylar resorptions (ICR) and compare these changes to a healthy control group. Materials and method: CBCT scans were analyzed using anatomical points on the skull to create a reference line....... Subsequently, anatomical structures were identified on the mandible to measure the condylar axial angle, the condylar neck angle as well as the condylar width, length, and height in 25 patients with ICR and 25 controls (50 joints in each group). Secondly, cross sections of the TMJs were evaluated for deformity...... %), cavitation defect (22 %), and flattering (22 %). In the control group condylar flattening was seen in 2 %. More than 70 % of the joints with deformity changes evaluated in the sagittal and the coronal plane respectively showed deformity changes along the entire condylar surface. Conclusion: The results...

Three dimensional assessment of condylar surface changes and remodeling after orthognathic surgery

International Nuclear Information System (INIS)

Lee, Jung Hye; Lee, Jin Woo; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Shin, Jae Myung

2016-01-01

This study was performed to evaluate condylar surface changes and remodeling after orthognathic surgery using three-dimensional computed tomography (3D CT) imaging, including comparisons between the right and left sides and between the sexes. Forty patients (20 males and 20 females) who underwent multi-detector CT examinations before and after surgery were selected. Three-dimensional images comprising thousands of points on the condylar surface were obtained before and after surgery. For the quantitative assessment of condylar surface changes, point-to-point (preoperative-to-postoperative) distances were calculated using D processing software. These point-to-point distances were converted to a color map. In order to evaluate the types of condylar remodeling, the condylar head was divided into six areas (anteromedial, anteromiddle, anterolateral, posteromedial, posteromiddle, and posterolateral areas) and each area was classified into three types of condylar remodeling (bone formation, no change, and bone resorption) based on the color map. Additionally, comparative analyses were performed between the right and left sides and according to sex. The mean of the average point-to-point distances on condylar surface was 0.11±0.03 mm. Bone resorption occurred more frequently than other types of condylar remodeling, especially in the lateral areas. However, bone formation in the anteromedial area was particularly prominent. No significant difference was found between the right and left condyles, but condylar surface changes in males were significantly larger than in females. This study revealed that condylar remodeling exhibited a tendency towards bone resorption, especially in the lateral areas. Condylar surface changes occurred, but were small

Three dimensional assessment of condylar surface changes and remodeling after orthognathic surgery

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Lee, Jung Hye; Lee, Jin Woo; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Shin, Jae Myung [Dept. of Oral and Maxillofacial Surgery, Ilsan Paik Hospital, Inje University College of Medicine, Goyang (Korea, Republic of)

2016-03-15

This study was performed to evaluate condylar surface changes and remodeling after orthognathic surgery using three-dimensional computed tomography (3D CT) imaging, including comparisons between the right and left sides and between the sexes. Forty patients (20 males and 20 females) who underwent multi-detector CT examinations before and after surgery were selected. Three-dimensional images comprising thousands of points on the condylar surface were obtained before and after surgery. For the quantitative assessment of condylar surface changes, point-to-point (preoperative-to-postoperative) distances were calculated using D processing software. These point-to-point distances were converted to a color map. In order to evaluate the types of condylar remodeling, the condylar head was divided into six areas (anteromedial, anteromiddle, anterolateral, posteromedial, posteromiddle, and posterolateral areas) and each area was classified into three types of condylar remodeling (bone formation, no change, and bone resorption) based on the color map. Additionally, comparative analyses were performed between the right and left sides and according to sex. The mean of the average point-to-point distances on condylar surface was 0.11±0.03 mm. Bone resorption occurred more frequently than other types of condylar remodeling, especially in the lateral areas. However, bone formation in the anteromedial area was particularly prominent. No significant difference was found between the right and left condyles, but condylar surface changes in males were significantly larger than in females. This study revealed that condylar remodeling exhibited a tendency towards bone resorption, especially in the lateral areas. Condylar surface changes occurred, but were small.

Long-term results of nonsurgical management of condylar fractures in children

NARCIS (Netherlands)

Hovinga, J; Boering, G; Stegenga, B

1999-01-01

Twenty-five patients with 28 condylar or subcondylar fractures, sustained during their growth period and treated nonsurgically, have been followed for an average period of 15 years. The fractures were classified as intracapsular, high condylar neck and low condylar neck fractures, In 5 patients, two

[Management of disk displacement with condylar fracture].

Science.gov (United States)

Yu, Shi-bin; Li, Zu-bing; Yang, Xue-wen; Zhao, Ji-hong; Dong, Yao-jun

2003-07-01

To investigate clinical features of disk displacement during the course of condylar fracture and to explore the techniques of disk reposition and suturation. 32 patients (10 females and 22 males) who had disk displacements with condylar fractures were followed up. Reduction and reposition of the dislocated disks simultaneously with fixation of fractures were performed. 7 patients underwent intermaxillary fixation with elastic bands for 1 to 2 weeks. The occlusions were satisfactory in all cases but one for the reason of ramus height loss. No TMJ symptom was found when examined 3 months post operation. Anterior disk displacements were most occurred with high condylar process fractures. Surgical reposition and suturation of disk play an important role for the later TMJ-function.

Radiographic normal range of condylar movement of mandible

International Nuclear Information System (INIS)

Choi, Byung Ihn; Lee, Jae Mun; Kim, Myung Jin

1981-01-01

It is the purpose of this article to determine various normal anatomic measurements of temporomandibular joint and normal range of condylar movement using relatively simple X-ray equipment and radiographic technique in consideration of popular clinical application. Author's cases consisted of 100 clinically normal adult males and temporomandibular joint radiographs of 3 serial positions of condylar head were taken by transcranial oblique lateral projection in each case. The serial positions are centric occlusion, 1 inch opening and maximal opening position. The results were as follows; 1. In centric occlusion, the length between the condylar head and glenoid fossa was 2.23 ± 0.58 mm in anterior part, 3.55 ± 0.80 mm in upper part and 2.76 ± 0.72 mm in posterior part. 2. In centric occlusion, the angle (α) between the horizontal standard line (AB) and anterior slope (BC) was 37.22 ± 3.87 .deg. . 3. In 1 inch opening position, the distance between the summit of condylar head from the standard point of articular eminence (B) was -0.64 ± 3.53 mm in horizontal direction and -1.07 ± 1.00 mm in vertical direction. 4. In maximal opening position, the distance between the summit of condylar head from the standard point of articular eminence (B) was 5.83 ± 3.05 mm in horizontal direction and +0.29 ± 1.58 mm in vertical direction. 5. In positional relationship between the condylar head and the standard point of articular eminence (B), the condyles were found to be at the eminences or anterior to them in 51% with 1 inch opening and 95% with maximal opening

Bilateral condylar resorption in down syndrome.

Science.gov (United States)

Grippaudo, Cristina; Grippaudo, Francesca Romana; Marianetti, Tito Matteo; Cacucci, Laura; Deli, Roberto; Pelo, Sandro

2014-11-01

Asymptomatic idiopathic condylar resorption is a rare disease of difficult diagnosis and treatment. We review the literature about this rare condition and report a case of a patient, affected by Down syndrome, who underwent a complete untreated bilateral condylar resorption in adolescence and then developed pain on chewing only 20 years later. Despite a precise orthodontic and surgical therapeutic plan, treatment had to be discontinued because of patient lack of compliance. This case is the first of its kind to be reported and emphasizes the need for special attention in patients with disability.

Relationship of condylar position to disc position and morphology

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Incesu, L.; Taskaya-Yilmaz, N. E-mail: nergizy@omu.edu.tr; Oeguetcen-Toller, M.; Uzun, E

2004-09-01

Introduction/objective: The purpose of this study was to assess whether condylar position, as depicted by magnetic resonance imaging, was an indicator of disc morphology and position. Methods and material: One hundred and twenty two TMJs of 61 patients with temporomandibular joint disorder were examined. Condylar position, disc deformity and degree of anterior disc displacement were evaluated by using magnetic resonance imaging. Results and discussion: Posterior condyle position was found to be the main feature of temporomandibular joints with slight and moderate anterior disc displacement. No statistical significance was found between the condylar position, and reducing and nonreducing disc positions. On the other hand, superior disc position was found to be statistically significant for centric condylar position. Conclusion: It was concluded that posterior condyle position could indicate anterior disc displacement whereas there was no relation between the position of condyle and the disc deformity.

Anatomical reconstruction of unstable trochanteric fractures through posterior approach

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Partha Saha

2015-01-01

Full Text Available Objective Unstable intertrochanteric fractures continue to be a challenge for orthopedic surgeons due to the functional limitations it results in the postoperative period. Anatomical reconstruction of the posteromedial fragment becomes difficult through conventional lateral approach, leading to excessive fracture collapse and limping. Materials and Methods: prospective, nonrandomized study was done with 40 patients. They were operated in prone position through posterior approach. Cancellous screws or SS-wires were used to fix the greater or lesser trochanteric fragments and dynamic hip screw (DHS or dynamic condylar screw (DCS for the main two fragments. Bone grafts were used to pack cavities at the posterior trochanteric regions. Results: Fracture healing occurred earlier compared to conventional lateral approach without excessive fracture collapse in majority of cases (average time to achieve union was 13.8 weeks; range: 10–18 weeks. Good functional recovery was noted with 75% 'Good' or 'Excellent' Harris Hip Scores at 24 weeks. Conclusion: Anatomical reconstruction of unstable trochanteric fractures becomes easier through posterior approach with earlier and better functional recovery.

Occlusal consequence of using average condylar guidance settings: An in vitro study.

Science.gov (United States)

Lee, Wonsup; Lim, Young-Jun; Kim, Myung-Joo; Kwon, Ho-Beom

2017-04-01

A simplified mounting technique that adopts an average condylar guidance has been advocated. Despite this, the experimental explanation of how average settings differ from individual condylar guidance remains unclear. The purpose of this in vitro study was to examine potential occlusal error by using average condylar guidance settings during nonworking side movement of the articulator. Three-dimensional positions of the nonworking side maxillary first molar at various condylar and incisal settings were traced using a laser displacement sensor attached to the motorized stages with biaxial freedom of movement. To examine clinically relevant occlusal consequences of condylar guidance setting errors, the vertical occlusal error was defined as the vertical-axis positional difference between the average setting trace and the other condylar guidance setting trace. In addition, the respective contribution of the condylar and incisal guidance to the position of the maxillary first molar area was analyzed by multiple regression analysis using the resultant coordinate data. Alteration from individual to average settings led to a positional difference in the maxillary first molar nonworking side movement. When the individual setting was lower than average, vertical occlusal error occurred, which might cause occlusal interference. The vertical occlusal error ranged from -2964 to 1711 μm. In addition, the occlusal effect of incisal guidance was measured as a partial regression coefficient of 0.882, which exceeded the effect of condylar guidance, 0.431. Potential occlusal error as a result of adopting an average condylar guidance setting was observed. The occlusal effect of incisal guidance doubled the effect of condylar guidance. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

[Clinical application of artificial condylar process for reconstructing temporomandibular joint].

Science.gov (United States)

Huang, Xiangdao; Shao, Zhanying; Wang, Fasheng; Duan, Yi

2012-01-01

To assess the feasibility and clinical outcomes of artificial condylar process in reconstruction of the temporomandibular joint. Between January 2005 and January 2010, the reconstructions of the temporomandibular joints with artificial condylar process were performed in 10 cases (11 sides, including 7 left sides and 4 right sides). There were 7 males and 3 females with an average age of 50 years (range, 40-68 years). Mandibular condyle defects were caused by mandible tumor in 7 patients with a mean disease duration of 15 months (range, 9-24 months) and by bilateral condylar fractures in 3 patients with the disease duration of 2, 3, and 2 days respectively. According to Neff classification, there were type M and A in 1 case, type M and B in 1 case, and type M in one side and subcondylar fracture in the other side in 1 case. Incisions in all patients healed by first intention, and no complication occurred. All cases were followed up 1 to 4 years, showed facial symmetry and good occluding relation, and the mouth opening was 22-38 mm (mean, 30 mm). No temporomandibular joint clicking or pain and no recurrence of tumor were observed. Most of the artificial condylar process were in good position except 1 deviated from the correct angle slightly. All the patients could have diet normally. The results of temporomandibular joint reconstruction after tumor resection with artificial condylar process are good, but the clinical outcome for intracapsular condylar fracture is expected to be further verified.

Treatment of displaced mandibular condylar fracture with botulinum toxin A.

Science.gov (United States)

Akbay, Ercan; Cevik, Cengiz; Damlar, Ibrahim; Altan, Ahmet

2014-04-01

The aim of this case report is to discuss the effect on condylar reduction of botulinum toxin A treatment used in a child with displaced fracture at condylar neck of mandible. A 3-years old boy was admitted to our clinic for incomplete fracture of mandibular symphysis and displaced condylar fracture at the left side. An asymmetrical occlusal splint with intermaxillary fixation was used instead of open reduction and internal fixation because of incomplete fracture of symphysis and possible complications of condyle surgery. However, it was observed that condylar angulation persisted despite this procedure. Thus, botulinum toxin A was administered to masseter, temporalis and pterygoideus medialis muscles. At the end of first month, it was seen that mandibular condyle was almost completely recovered and that fusion was achieved. In conclusion, Botulinum A toxin injection aiming the suppression of masticatory muscle strength facilitates the reduction in the conservative management of displaced condyle in pediatric patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Condylar volume and surface in Caucasian young adult subjects

International Nuclear Information System (INIS)

Tecco, Simona; Saccucci, Matteo; Nucera, Riccardo; Polimeni, Antonella; Pagnoni, Mario; Cordasco, Giancarlo; Festa, Felice; Iannetti, Giorgio

2010-01-01

There have been no quantitative standards for volumetric and surface measurements of the mandibular condyle in Caucasian population. However, the recently developed cone-beam computed tomography (CBCT) system allows measurement of these parameters with high accuracy. CBCT was used to measure the condylar volume, surface and the volume to surface ratio, called the Morphometric Index (MI), of 300 temporo-mandibular joints (TMJ) in 150 Caucasian young adult subjects, with varied malocclusions, without pain or dysfunction of TMJs. The condylar volume was 691.26 ± 54.52 mm 3 in males and 669.65 ± 58.80 mm 3 in, and was significantly higher (p< 0.001) in the males. The same was observed for the condylar surface, although without statistical significance (406.02 ± 55.22 mm 2 in males and 394.77 ± 60.73 mm 2 in females). Furthermore, the condylar volume (693.61 ± 62.82 mm 3 ) in the right TMJ was significantly higher than in the left (666.99 ± 48.67 mm 3 , p < 0.001) as was the condylar surface (411.24 ± 57.99 mm 2 in the right TMJ and 389.41 ± 56.63 mm 2 in the left TMJ; t = 3.29; p < 0.01). The MI is 1.72 ± 0.17 for the whole sample, with no significant difference between males and females or the right and left sides. These data from temporomandibular joints of patients without pain or clinical dysfunction might serve as examples of normal TMJ's in the general population not seeking orthodontic care

Evaluation of mandibular condylar changes in patients following orthognathic surgery: A retrospective study

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Vikas Aneja

2017-01-01

Full Text Available Background: Condylar resorption as a cause of relapse after orthognathic surgery is well known. Several authors have presented evidence of the relation between orthognathic surgery and condylar remodeling and resorption. This study was done to appraise the condylar changes along with the form and function following orthognathic surgery, as well as to assess what factors may have contributed to the problems. Methodology: A diagnosis of progressive condylar resorption (PCR was made by comparison of preoperative and postoperative radiographs (cephalometric radiograms, as well as clinical evaluations. The radiographs were taken for each patient preoperatively and postoperatively, which include immediately after osteotomy, at 6 months and 24 months. Additional radiographs were taken when required. Then, preoperative and postoperative tracings were compared at 24 months postoperatively. Results and Conclusion: It can be concluded from this study that females of relative low age (<18 years appeared to be a high-risk factor for the occurrence of condylar alteration including PCR. A steep mandibular plane angle, the low facial height ratio (post/ant, and magnitude of surgery were also significantly related to the occurrence of condylar alteration, but the multivariance regression showed that these parameters had only limited value.

Condyle and mandibular bone change after unilateral condylar neck fracture in growing rats.

Science.gov (United States)

Hu, Y; Yang, H-f; Li, S; Chen, J-z; Luo, Y-w; Yang, C

2012-08-01

Unilateral fracture of the condylar neck in immature subjects might lead to mandible asymmetry and condyle remodelling. A rat model was used to investigate mandibular deviation and condylar remodelling associated with condyle fracture. 72 4-week-old male rats were randomly divided into three groups: an experimental group (unilateral transverse condylar fracture induced surgically), a sham operation group (surgical exposure but no fracture), and a non-operative control group (no operation). The rats were killed at intervals up to 9weeks after surgery, and outcomes were assessed using various measures of mandible deviation, histological and X-ray observation, and immunohistochemical measures of expression levels of connective tissue growth factor (CTGF) and type II collagen (Col II). The fracture led to the degeneration of mandibular size, associated with atrophy of fractured condylar process. Progressive remodelling of cartilage and increasing expression levels of CTGF and Col II were found. The authors conclude that condylar fracture can lead to asymmetries in mandible and condyle remodelling and expression of CTGF and Col II in condylar cartilage on both the ipsilateral and the contralateral sides. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Radiographic study of bone deformans on charged condylar head position in TMJ arthrosis

International Nuclear Information System (INIS)

You, Dong Soo

1983-01-01

The author analyzed the morphologic changes of bone structure from 848 radiographics (424 joints) of 212 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral transcranial projection and ortho pantomography. The interrelation of the bone changes and condylar head positions the results were as follows: 1. In the 212 patients with TMJ arthrosis, 210 patients (99.05%) show the condylar positional changes. Among them, 187 patients (89.05%) show the bone changes. 2. In TMJ arthrosis patients with bone changes, 108 patients (57.75%) show both the condylar positional changes and bone changes. 66 patients show the condylar positional changes bilaterally and bone changes unilaterally. On the other hand, 11 patients (5.88%) show the condylar positional changes unilaterally and bone change bilaterally. 3. The bone changes in the TMJ arthrosis patients with the condylar positional changes were as follows: There were the flattening of articular surface in 103 cases (26.55%) the erosion in 99 cases (25.52%), and the erosion in 88 cases (22.68%). There were not much differences among the three types of bone changes. And the deformity in 70 cases (18.04%), the sclerosis in 22 cases (5.67%), the marginal proliferation in 6 cases (1.55%) were seen. 4. The regions of bone changes in TMJ arthrosis patients with condylar positional changes were as follows: They occurred at the condyle head (51.04%), the articular eminence (39.20%) and the articular fossa (9.60%) in that order. The condylar positional changes and bone changes according to the regions were as follows: a) In the bone changes at the condylar head, the flattening (34.63%) was a most frequent finding and the deformity (27.63%) the erosion (34.63%) in the order. In the condylar positional changes, the downward positioning of condyle (41.44%) was a most frequent finding in the mouth closed state and the restricted movement within the articular fossa (35.46%) in the mouth open state. b) In

Radiographic study of bone deformans on charged condylar head position in TMJ arthrosis

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You, Dong Soo [Department of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1983-11-15

The author analyzed the morphologic changes of bone structure from 848 radiographics (424 joints) of 212 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral transcranial projection and ortho pantomography. The interrelation of the bone changes and condylar head positions the results were as follows: 1. In the 212 patients with TMJ arthrosis, 210 patients (99.05%) show the condylar positional changes. Among them, 187 patients (89.05%) show the bone changes. 2. In TMJ arthrosis patients with bone changes, 108 patients (57.75%) show both the condylar positional changes and bone changes. 66 patients show the condylar positional changes bilaterally and bone changes unilaterally. On the other hand, 11 patients (5.88%) show the condylar positional changes unilaterally and bone change bilaterally. 3. The bone changes in the TMJ arthrosis patients with the condylar positional changes were as follows: There were the flattening of articular surface in 103 cases (26.55%) the erosion in 99 cases (25.52%), and the erosion in 88 cases (22.68%). There were not much differences among the three types of bone changes. And the deformity in 70 cases (18.04%), the sclerosis in 22 cases (5.67%), the marginal proliferation in 6 cases (1.55%) were seen. 4. The regions of bone changes in TMJ arthrosis patients with condylar positional changes were as follows: They occurred at the condyle head (51.04%), the articular eminence (39.20%) and the articular fossa (9.60%) in that order. The condylar positional changes and bone changes according to the regions were as follows: a) In the bone changes at the condylar head, the flattening (34.63%) was a most frequent finding and the deformity (27.63%) the erosion (34.63%) in the order. In the condylar positional changes, the downward positioning of condyle (41.44%) was a most frequent finding in the mouth closed state and the restricted movement within the articular fossa (35.46%) in the mouth open state. b) In

Correlation between Condylar Fracture Pattern after Parasymphyseal Impact and Condyle Morphological Features: A Retrospective Analysis of 107 Chinese Patients.

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Han, Lu; Long, Ting; Tang, Wei; Liu, Lei; Jing, Wei; Tian, Wei-Dong; Long, Jie

2017-02-20

The treatment of the condylar fractures is difficult. Factors that result in the fractures are complex. The objective of this morphometric study was to investigate the relationship between condylar fracture patterns and condylar morphological characteristics. We conducted a retrospective analysis of 107 patients admitted to the West China Hospital of Stomatology for bilateral condylar fractures caused by parasymphyseal impact. The patients were divided into five groups according to the type of condylar fracture. Ten parameters were evaluated on three-dimensional (3D) reconstruction mandible models through the Mimics 16.0 (Materialize Leuven, Belgium) anthropometry toolkit. Each parameter of the 3D models was analyzed using multivariate analysis. Multinomial logistic regression analyses were used to examine the relationships between the five groups. The results showed that the differences of condylar head width (M1), condylar neck width (M3), the ratio of condylar head width to condylar anteroposterior diameter (M1/M2), the ratio of condylar head width to condylar neck width (M1/M3), the ratio of condylar height to ramus height (M8/M7), and mandibular angle (M10) were statistically significant (p fractures were positively associated with M1 (compared to Type B: OR =1.627, 95% CI: 1.123, 2.359; compared to Type C: OR = 1.705, 95% CI: 1.170, 2.484) and M1/M2 (compared to Type B: OR =1.034, 95% CI: 0.879, 2.484). Type B condylar head fractures were negatively associated with M10 (compared to Type C: OR = 0.909, 95% CI: 0.821, 1.007). Condylar neck fractures were negatively associated with M3 (compared to condylar head: OR = 0.382, CI: 0.203, 0.720 ; compared to condylar base: OR = 0.436, 95% CI: 0.218, 0.874), and positively associated with M1/M3 (compared to condylar head: OR = 1.229, 95% CI: 1.063, 1.420 compared to condylar base: OR = 1.223, 95% CI: 1.034, 1.447). Condylar base fractures were positively associated with M10 (OR = 1.095, 95% CI: 1.008, 1.189) and

Dynamic compression plate (DCP) fixation of propagating medial condylar fractures of the third metacarpal/metatarsal bone in 30 racehorses: retrospective analysis (1990-2005).

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Goodrich, L R; Nixon, A J; Conway, J D; Morley, P S; Bladon, B M; Hogan, P M

2014-11-01

An in-depth review of dynamic compression plate (DCP) fixation of propagating medial condyle fractures of the third metacarpus or metatarsus has not been previously reported. To describe the technique, evaluate short-term outcome and long-term race performance of racehorses that underwent DCP fixation for repair of propagating or spiralling medial condylar fractures of the third metacarpal (McIII) or metatarsal (MtIII) bone. Retrospective case series. The surgical case records of 30 horses with propagating fractures of the medial condyle of McIII or MtIII were reviewed. Medical information included: age, breed, sex, presentation, how injury occurred (racing or training), surgical treatment and post operative complications. Racing information included: starts, top 3 placing and career earnings. Long propagating fractures of the medial condyle of Mc/tIII were identified in 23 Thoroughbred (TB) and 7 Standardbred (STB) racehorses. The fracture spiralled proximally in 22 of 30 cases (73%). Standardbreds had a higher propensity for hindlimb involvement (71%), whereas TBs tended to have more front limb involvement (61%). Twelve of 30 (40%) horses raced post surgery. Career earnings were significantly lower for TB horses with medial condylar fractures; $34,916 when compared with the national average of $60,841 (P≤0.03). Overall, horses having DCP fixation for medial condylar fractures had less starts post surgery (3.1 TBs and 5.8 STBs) compared with the national average (7 TBs and 17.3 STBs) and decreased lifetime starts 13.4 (TBs) compared with 17.3 nationally. Propagating medial condyle fractures can be repaired with plate fixation to potentially lessen the risk of catastrophic fracture destabilisation and return to racing can be expected in 40% of horses. Further prospective studies are warranted comparing lag screw fixation with DCP fixation for repair of severe medial condylar fractures of the metacarpus/metatarsus. © 2013 The Authors. Equine Veterinary Journal

Effects of intermittent versus continuous parathyroid hormone administration on condylar chondrocyte proliferation and differentiation

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Liu, Qi; Wan, Qilong; Yang, Rongtao; Zhou, Haihua; Li, Zubing

2012-01-01

Highlights: ► Different PTH administration exerts different effects on condylar chondrocyte. ► Intermittent PTH administration suppresses condylar chondrocyte proliferation. ► Continuous PTH administration maintains condylar chondrocyte proliferating. ► Intermittent PTH administration enhances condylar chondrocyte differentiation. -- Abstract: Endochondral ossification is a complex process involving chondrogenesis and osteogenesis regulated by many hormones and growth factors. Parathyroid hormone (PTH), one of the key hormones regulating bone metabolism, promotes osteoblast differentiation and osteogenesis by intermittent administration, whereas continuous PTH administration inhibits bone formation. However, the effects of PTH on chondrocyte proliferation and differentiation are still unclear. In this study, intermittent PTH administration presented enhanced effects on condylar chondrocyte differentiation and bone formation, as demonstrated by increased mineral nodule formation and alkaline phosphatase (ALP) activity, up-regulated runt-related transcription factor 2 (RUNX2), ALP, collagen type X (COL10a1), collagen type I (COL1a1), osteocalcin (OCN), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2) and osterix (OSX) mRNA and/or protein expression. On the contrary, continuous PTH administration promoted condylar chondrocyte proliferation and suppressed its differentiation, as demonstrated by up-regulated collagen type II (COL2a1) mRNA expression, reduced mineral nodule formation and down-regulated expression of the mRNAs and/or proteins mentioned above. Our data suggest that PTH can regulate condylar chondrocyte proliferation and differentiation, depending on the type of PTH administration. These results provide new insight into the effects of PTH on condylar chondrocytes and new evidence for using local PTH administration to cure mandibular asymmetry.

Open Reduction in Pediatric Condylar Fracture.

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Barbosa, Alexandre Agostini; Mariano, Ronaldo Célio

2017-05-01

Facial fractures in children are rare. Lack of pneumatization, fat pockets, mixed dentition, contribute to the elasticity and bone stability. When mandibular fractures occur in children, most often involve the condyle by indirect trauma. Such fractures are the center of discussion on the form of treatment if this should be performed conservatively, or held the reduction and fixation of the fracture with surgical exposure of the fragments. In condylar fractures in children, in most patients, the proposed treatment is closed reduction. Treatment with open reduction and fixation has its specific indications. In this case, the authors report a patient cycling accident victim, with cut-contusion injury in ment with limited mouth opening and left condylar fracture with medial rotation. The treatment was the reduction and fixation of fragments by open process.

Effects of intermittent versus continuous parathyroid hormone administration on condylar chondrocyte proliferation and differentiation

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Liu, Qi; Wan, Qilong; Yang, Rongtao; Zhou, Haihua [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079 (China); Li, Zubing, E-mail: lizubing0827@163.com [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079 (China)

2012-07-20

Highlights: Black-Right-Pointing-Pointer Different PTH administration exerts different effects on condylar chondrocyte. Black-Right-Pointing-Pointer Intermittent PTH administration suppresses condylar chondrocyte proliferation. Black-Right-Pointing-Pointer Continuous PTH administration maintains condylar chondrocyte proliferating. Black-Right-Pointing-Pointer Intermittent PTH administration enhances condylar chondrocyte differentiation. -- Abstract: Endochondral ossification is a complex process involving chondrogenesis and osteogenesis regulated by many hormones and growth factors. Parathyroid hormone (PTH), one of the key hormones regulating bone metabolism, promotes osteoblast differentiation and osteogenesis by intermittent administration, whereas continuous PTH administration inhibits bone formation. However, the effects of PTH on chondrocyte proliferation and differentiation are still unclear. In this study, intermittent PTH administration presented enhanced effects on condylar chondrocyte differentiation and bone formation, as demonstrated by increased mineral nodule formation and alkaline phosphatase (ALP) activity, up-regulated runt-related transcription factor 2 (RUNX2), ALP, collagen type X (COL10a1), collagen type I (COL1a1), osteocalcin (OCN), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2) and osterix (OSX) mRNA and/or protein expression. On the contrary, continuous PTH administration promoted condylar chondrocyte proliferation and suppressed its differentiation, as demonstrated by up-regulated collagen type II (COL2a1) mRNA expression, reduced mineral nodule formation and down-regulated expression of the mRNAs and/or proteins mentioned above. Our data suggest that PTH can regulate condylar chondrocyte proliferation and differentiation, depending on the type of PTH administration. These results provide new insight into the effects of PTH on condylar chondrocytes and new evidence for using local PTH administration to cure mandibular

Mastication markedly affects mandibular condylar cartilage growth, gene expression, and morphology.

Science.gov (United States)

Enomoto, Akiko; Watahiki, Junichi; Nampo, Tomoki; Irie, Tarou; Ichikawa, Yuuta; Tachikawa, Tetsuhiko; Maki, Koutaro

2014-09-01

Mandibular growth is believed to be strongly related to mastication. Furthermore, mandibular condylar cartilage is known to be derived from neural crest cells. We examined whether the degree of chewing affects condylar cartilage growth of the mandible. Mice were fed diets with varying hardness. Genes specific to neural crest-derived cells were measured by real-time polymerase chain reaction to compare the expression changes between the mandibular and tibia cartilages. The mandibular condylar cartilage was then evaluated histologically, and proliferation was evaluated using proliferating cell nuclear antigen. Immunostaining was conducted for osteopontin, type X collagen, and Musashi1, and real-time polymerase chain reaction was used to assess the expression levels of osteopontin and type X collagen. Markers including P75, Wnt-1, Musashi1, and Nestin were upregulated in the mandibular condylar cartilage as compared with the tibial cartilage. Histologic assessment of the mandibular cartilage showed that the hypertrophic chondrocyte zone was statistically significantly thicker in mice fed a hard diet. Chondrocyte proliferation and Musashi1 expression were lower in mice fed a hard diet. After 4 weeks, numerous osteopontin and type X collagen-positive cells were observed in mice fed a mixed diet. Mastication affects the balance between differentiation and proliferation in the mandibular condylar cartilage. This phenomenon might be attributed to the presence of neural crest-derived cells. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Removal torque of nail interlocking screws is related to screw proximity to the fracture and screw breakage.

Science.gov (United States)

White, Alexander A; Kubacki, Meghan R; Samona, Jason; Telehowski, Paul; Atkinson, Patrick J

2016-06-01

Studies have shown that titanium implants can be challenging to explant due to the material's excellent biocompatibility and resulting osseointegration. Clinically, titanium alloy nail interlocking screws may require removal to dynamize a construct or revise the nail due to nonunion, infection, pain, or periprosthetic fracture. This study was designed to determine what variables influence the removal torque for titanium alloy interlocking screws. An intramedullary nail with four interlocking screws was used to stabilize a 1-cm segmental femoral defect in a canine model for 16 weeks. The animals were observed to be active following a several-day recovery after surgery. In six animals, the femora and implanted nail/screws were first tested to failure in torsion to simulate periprosthetic fracture of an implant after which the screws were then removed. In four additional animals, the screws were removed without mechanical testing. Both intraoperative insertional and extraction torques were recorded for all screws. Mechanical testing to failure broke 10/24 screws. On average, the intact screws required 70% of the insertional torque during removal while broken screws only required 16% of the insertional torque (p torque than the outboard distal screw (p torque was ∼80°. The peak axial load did not significantly correlate with the torque required to remove the screws. On average, the removal torque was lower than at the time of insertion, and less torque was required to remove broken screws and screws remote to the fracture. However, broken screws will require additional time to retrieve the remaining screw fragment. This study suggests that broken screws and screws in prematurely active patients will require less torque to remove. © IMechE 2016.

Ball Screw Actuator Including a Compliant Ball Screw Stop

Science.gov (United States)

Wingett, Paul T. (Inventor); Hanlon, Casey (Inventor)

2017-01-01

An actuator includes a ball nut, a ball screw, and a ball screw stop. The ball nut is adapted to receive an input torque and in response rotates and supplies a drive force. The ball screw extends through the ball nut and has a first end and a second end. The ball screw receives the drive force from the ball nut and in response selectively translates between a retract position and a extend position. The ball screw stop is mounted on the ball screw proximate the first end to translate therewith. The ball screw stop engages the ball nut when the ball screw is in the extend position, translates, with compliance, a predetermined distance toward the first end upon engaging the ball nut, and prevents further rotation of the ball screw upon translating the predetermined distance.

Digital diagnosis and treatment of mandibular condylar fractures based on Extensible Neuro imaging Archive Toolkit (XNAT.

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ZhongWei Zhou

Full Text Available The treatment of condylar fractures has long been controversial. In this paper, we established a database for accurate measurement, storage, management and analysis of patients' data, in order to help determine the best treatment plan.First of all, the diagnosis and treatment database was established based on XNAT, including 339 cases of condylar fractures and their related information. Then image segmentation, registration and three-dimensional (3D measurement were used to measure and analyze the condyle shapes. Statistical analysis was used to analyze the anatomical structure changes of condyle and the surrounding tissues at different stages before and after treatment. The processes of condylar fracture reestablishment at different stages were also dynamically monitored. Finally, based on all these information, the digital diagnosis and treatment plans for condylar fractures were developed.For the patients less than 18 years old with no significant dislocation, surgical treatment and conservative treatment were equally effective for intracapsular fracture, and had no significant difference for neck and basal fractures. For patients above 18 years old, there was no significant difference between the two treatment methods for intracapsular fractures; but for condylar neck and basal fractures, surgical treatment was better than conservative treatment. When condylar fracture shift angle was greater than 11 degrees, and mandibular ramus height reduction was greater than 4mm, the patients felt the strongest pain, and their mouths opening was severely restricted. There were 170 surgical cases with condylar fracture shift angel greater than 11 degrees, and 118 of them (69.4% had good prognosis, 52 of them (30.6% had complications such as limited mouth opening. There were 173 surgical cases with mandibular ramus height reduction more than 4mm, and 112 of them (64.7% had good prognosis, 61 of them (35.3% had complications such as limited mouth opening

Conservative orthodontic fixed appliance management of pediatric mandibular bilateral condylar fracture.

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Xu, Yanhua; Gong, Siew-Ging; Zhu, Fangyong; Li, Ming; Biao, Xu

2016-07-01

Management of mandibular condylar fractures is difficult in children with their inherently dynamic and unstable deciduous and mixed dentitions. We present a variation of the conservative fixed orthodontic approach that was used as an adjunct to aid in the reduction of a bilateral condylar fracture in a pediatric patient. A boy, aged 10 years 9 months, came with clinical signs and symptoms of mandibular fracture after being involved in a motor vehicle accident. A computed tomography scan showed a vertical fracture on the left condylar head, a displaced fracture of the right condylar neck, and a mandibular symphysis fracture. The patient was treated with an orthodontic fixed appliance instead of an arch bar splint, followed by elastic traction to achieve a proper occlusion and condylar remodeling. Follow-up appointments were made 2 weeks and 1, 2, 20, 37, and 49 months after treatment. Clinical recovery was observed 2 months after treatment. At the follow-up appointments at 20, 37, and 49 months, jaw function and occlusal relationship remained stable, and no ankylosis was observed. The computed tomography scans showed that the right condyle had remodeled, and the left condyle exhibited a slight curve in the head at 49 months posttreatment. The patient's satisfaction with these treatment results was high. Conservative treatment of a mandibular fracture by fixed orthodontic means is a viable treatment option that is relatively straightforward and cost-effective and has a high level of patient acceptance and comfort. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

[Comparative effectiveness of surgical and non-surgical treatment for pediatric mandibular condylar fractures].

Science.gov (United States)

Hu, Min; Wang, Yanyi; Zhang, Lihai; Yao, Jun

2010-12-01

To compare the effectiveness of open reduction and conservative treatment for pediatric mandibular condylar fractures and to provide the evidence for the selection of clinical therapy. The clinical data were retrospectively analyzed from 25 patients with the mandibular condylar fractures between January 1988 and December 2006. Of them, 8 patients (11 fractures) were treated with surgical treatment (surgical group) and 17 patients (22 fractures) with non-surgical treatment (non-surgical group). In surgical group, there were 6 males (9 fractures) and 2 females (2 fractures) with an age range of 8-13 years; fracture was caused by tumbling in 7 cases and by traffic accident in 1 with an interval of 1-6 days between injury and hospitalization; and 5 cases were identified as unilateral condylar fractures (3 complicated by mental fractures) and 3 cases as bilateral condylar fractures complicated by mental fractures. In non-surgical group, there were 12 males (15 fractures) and 5 females (7 fractures) with an age range of 3-12 years; fracture was caused by falling from height in 4 cases, by tumbling in 10, and by traffic accident in 3 with an interval of 1-25 days between injury and hospitalization; and 12 cases were identified as unilateral condylar fractures (3 complicated by mental fractures) and 5 cases as bilateral condylar fractures (1 complicated by mental fracture). Incision healed by first intention in surgical group, and 25 cases were followed up 1-6 years with an average of 3.5 years. At 12 months after treatment, no temporomandibular joint pain, eating disorder, or limited mandibular movement occurred in 2 groups. No significant difference was observed in opening mouth extent, protrusive and lateral movements between 2 groups at 6 and 12 months (P > 0.05). During centric occlusion, mental point located at the midline with symmetric face figure. Two patients in surgical group and 3 in non-surgical group had slight snap when opening their mouths. Mandible

[Three-dimensional evaluation of condylar morphology remodeling after orthognathic surgery in mandibular retrognathism by cone-beam computed tomography].

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Chen, Shuo; Liu, Xiao-jing; Li, Zi-li; Liang, Cheng; Wang, Xiao-xia; Fu, Kai-yuan; Yi, Biao

2015-08-18

To evaluate the effect of orthognathic surgery on condylar morphology changes by comparing three-dimension surface reconstructions of condyles using cone-beam computed tomography (CBCT) data. In the study, 18 patients with mandible retrognathism deformities were included and CBCT data of 36 temporomandibular joints were collected before surgery and 12 months after surgery. Condyles were reconstructed and superimposed pre- and post-operatively to compare the changes of condylar surfaces. One-sample t test and χ2 test were performed for the analysis of three-dimension metric measurement and condylar head remodeling signs. P<0.05 was considered significant. The root-mean-square (RMS) of condylar surface changes before and after the surgery was (0.37±0.11) mm, which was significant statistically (P<0.05). The distribution of condylar remodeling signs showed significant difference (P<0.05). Bone resorption occurred predominantly in the posterior area of condylar head and bone formation occurred mainly in the anterior area. Three-dimension superimposition method based on CBCT data showed that condylar morphology had undergone remodeling after mandibular advancement.

Comparison of 99mTc-MDP SPECT qualitative vs quantitative results in patients with suspected condylar hyperplasia.

Science.gov (United States)

López Buitrago, D F; Ruiz Botero, J; Corral, C M; Carmona, A R; Sabogal, A

To compare qualitative vs quantitative results of Single Photon Emission Computerised Tomography (SPECT), calculated from percentage of 99m Tc-MDP (methylene diphosphonate) uptake, in condyles of patients with a presumptive clinical diagnosis of condylar hyperplasia. A retrospective, descriptive study was conducted on the 99m Tc-MDP SPECT bone scintigraphy reports from 51 patients, with clinical impression of facial asymmetry related to condylar hyperplasia referred by their specialist in orthodontics or maxillofacial surgery, to a nuclear medicine department in order to take this type of test. Quantitative data from 99m Tc-MDP condylar uptake of each were obtained and compared with qualitative image interpretation reported by a nuclear medicine expert. The concordances between the 51 qualitative and quantitative reports results was established. The total sample included 32 women (63%) and 19 men (37%). The patient age range was 13-45 years (21±8 years). According to qualitative reports, 19 patients were positive for right side condylar hyperplasia, 12 for left side condylar hyperplasia, with 8 bilateral, and 12 negative. The quantitative reports diagnosed 16 positives for right side condylar hyperplasia, 10 for left side condylar hyperplasia, and 25 negatives. Nuclear medicine images are an important diagnostic tool, but the qualitative interpretation of the images is not as reliable as the quantitative calculation. The agreement between the two types of report is low (39.2%, Kappa=0.13; P>.2). The main limitation of quantitative reports is that they do not register bilateral condylar hyperplasia cases. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

Simple New Screw Insertion Technique without Extraction for Broken Pedicle Screws.

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Kil, Jin-Sang; Park, Jong-Tae

2018-05-01

Spinal transpedicular screw fixation is widely performed. Broken pedicle screw rates range from 3%-7.1%. Several techniques have been described for extraction of broken pedicle screws. However, most of these techniques require special instruments. We describe a simple, modified technique for management of broken pedicle screws without extraction. No special instruments or drilling in an adjacent pedicle are required. We used a high-speed air drill with a round burr. With C-arm fluoroscopy guidance, the distal fragment of a broken pedicle screw was palpated using free-hand technique through the screw entry hole. A high-speed air drill with a round burr (not a diamond burr) was inserted through the hole. Drilling began slowly and continued until enough space was obtained for new screw insertion. Using this space, we performed new pedicle screw fixation medially alongside the distal fragment of the broken pedicle screw. We performed the insertion with a previously used entry hole and pathway in the pedicle. The same size pedicle screw was used. Three patients were treated with this modified technique. New screw insertion was successful in all cases after partial drilling of the distal broken pedicle screw fragment. There were no complications, such as screw loosening, dural tears, or root injury. We describe a simple, modified technique for management of broken pedicle screws without extraction. This technique is recommended in patients who require insertion of a new screw. Copyright © 2017. Published by Elsevier Inc.

Surgical treatment of unilateral condylar hyperplasia with piezosurgery.

Science.gov (United States)

Chiarini, Luigi; Albanese, Massimo; Anesi, Alexandre; Galzignato, Pier-Francesco; Mortellaro, Carmen; Nocini, Pierfrancesco; Bertossi, Dario

2014-05-01

Unilateral condylar hyperplasia (UCH) is a disorder of unknown etiology mainly seen in growing patients, which results in facial asymmetry. High condylectomy alone or in association with orthognathic surgery can improve the occlusion and the facial aesthetics. Between 2005 and 2012, a total of 5 patients underwent high condylectomy for UCH using a piezoelectric cutting device. All patients were treated postoperatively with functional rehabilitation. The long-term follow-up showed that all patients had a satisfactory temporomandibular joint articular function associated with stable occlusion without any recurrence of further condylar growth. High condylectomy in the surgical treatment of unilateral UCH seems to be the procedure of choice in growing patients. The use of a piezoelectric cutting device allows a safe and less invasive high condylectomy.

Development of a computer-assisted system for model-based condylar position analysis (E-CPM).

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Ahlers, M O; Jakstat, H

2009-01-01

Condylar position analysis is a measuring method for the three-dimensional quantitative acquisition of the position of the mandible in different conditions or at different points in time. Originally, the measurement was done based on a model, using special mechanical condylar position measuring instruments, and on a research scale with mechanical-electronic measuring instruments. Today, as an alternative, it is possible to take measurements with electronic measuring instruments applied directly to the patient. The computerization of imaging has also facilitated condylar position measurement by means of three-dimensional data records obtained by imaging examination methods, which has been used in connection with the simulation and quantification of surgical operation results. However, the comparative measurement of the condylar position at different points in time has so far not been possible to the required degree. An electronic measuring instrument, allowing acquisition of the condylar position in clinical routine and facilitating later calibration with measurements from later examinations by data storage and use of precise equalizing systems, was therefore designed by the present authors. This measuring instrument was implemented on the basis of already existing components from the Reference CPM und Cadiax Compact articulator and registration systems (Gamma Dental, Klosterneuburg, Austria) as well as the matching CMD3D evaluation software (dentaConcept, Hamburg).

Assessment of condylar morphology and position using MSCT in an Asian population.

Science.gov (United States)

Liu, Qi; Wei, Xiaoer; Guan, Juanjuan; Wang, Ran; Zou, Derong; Yu, Lvfeng

2018-02-01

The purpose of the present study was to investigate the volume, surface, morphometric index (MI), and position of the condyle in a normal population by applying Mimics 17.0 software. Then, the difference between left and right sides, sex, and age can be explored, which will contribute to establish the reference value of condylar morphology and position in normal individuals, and help us to study characteristics of condylar morphology and position in abnormal individuals. Three-hundred subjects were enrolled in our study from the radiology department of Shanghai Jiao Tong University Affiliated Sixth People's Hospital. They were divided into three groups according to the age: group 1 (18-24 years old), group 2 (25-34 years old), and group 3 (35-44 years old). Each group included 100 subjects (with 50 males and 50 females). They were examined using multislice computed tomography (MSCT) after that. All images of condyle were reconstructed by Mimics 17.0 software, so as to measure the volume, surface, and MI of condyle, and to analyze the position of condyle in the articular fossa by means of joint spaces. The differences of condylar volume, surface, and MI between left and right sides were not obvious (P > 0.05). The condylar volume and surface were greater in males than females (P  0.05). No statistical differences were found in volume and surface among three age groups. However, the MI of group 1 was statistically lower than that of group 3 (P position (P > 0.05). Nevertheless, there were significant differences of condylar position regarding the gender and age (P position between left and right sides, but factors of gender and age were proven to have a certain influence on the morphology and position of the condyle. This information can be clinically useful in establishing the diagnostic criteria for condylar morphology and position in the normal Asian population. Examination of condylar morphology and position is important for evaluating the

Clinical and radiological outcomes of transoral endoscope-assisted treatment of mandibular condylar fractures.

Science.gov (United States)

You, H-J; Moon, K-C; Yoon, E-S; Lee, B-I; Park, S-H

2016-03-01

Fractures of the mandibular condyle are one of the most common craniofacial fractures. However, the diagnosis and treatment of these fractures is controversial because of the multiple surgical approaches available. The purposes of this study were to identify surgery-related technical tips for better outcomes and to evaluate the results as well as complications encountered during 7 years of endoscope use to supplement the limited intraoral approach in the treatment of mandibular condylar fractures. Between 2005 and 2012, 50 patients with condylar fractures underwent endoscope-assisted reduction surgery. Postoperative facial bone computed tomography and panoramic radiography demonstrated adequate reduction of the condylar fractures in all patients. No condylar resorption was detected, and most patients displayed a satisfactory functional and structural recovery. There was no facial nerve damage or transitory hypoesthesia, and there were no visible scars after the surgery. Transoral endoscope-assisted treatment is a challenging but reliable method with lower morbidity and a rapid recovery. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Pedicle screw anchorage of carbon fiber-reinforced PEEK screws under cyclic loading.

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Lindtner, Richard A; Schmid, Rene; Nydegger, Thomas; Konschake, Marko; Schmoelz, Werner

2018-03-01

Pedicle screw loosening is a common and significant complication after posterior spinal instrumentation, particularly in osteoporosis. Radiolucent carbon fiber-reinforced polyetheretherketone (CF/PEEK) pedicle screws have been developed recently to overcome drawbacks of conventional metallic screws, such as metal-induced imaging artifacts and interference with postoperative radiotherapy. Beyond radiolucency, CF/PEEK may also be advantageous over standard titanium in terms of pedicle screw loosening due to its unique material properties. However, screw anchorage and loosening of CF/PEEK pedicle screws have not been evaluated yet. The aim of this biomechanical study therefore was to evaluate whether the use of this alternative nonmetallic pedicle screw material affects screw loosening. The hypotheses tested were that (1) nonmetallic CF/PEEK pedicle screws resist an equal or higher number of load cycles until loosening than standard titanium screws and that (2) PMMA cement augmentation further increases the number of load cycles until loosening of CF/PEEK screws. In the first part of the study, left and right pedicles of ten cadaveric lumbar vertebrae (BMD 70.8 mg/cm 3  ± 14.5) were randomly instrumented with either CF/PEEK or standard titanium pedicle screws. In the second part, left and right pedicles of ten vertebrae (BMD 56.3 mg/cm 3  ± 15.8) were randomly instrumented with either PMMA-augmented or nonaugmented CF/PEEK pedicle screws. Each pedicle screw was subjected to cyclic cranio-caudal loading (initial load ranging from - 50 N to + 50 N) with stepwise increasing compressive loads (5 N every 100 cycles) until loosening or a maximum of 10,000 cycles. Angular screw motion ("screw toggling") within the vertebra was measured with a 3D motion analysis system every 100 cycles and by stress fluoroscopy every 500 cycles. The nonmetallic CF/PEEK pedicle screws resisted a similar number of load cycles until loosening as the contralateral standard

Inhibitory effect of immature dendritic cells (iDCs phagocytizing apoptotic lymphocytes on LPS-mediated activation of iDCs

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Yu-xiang WEI

2013-09-01

Full Text Available Objective　To investigate the inhibitory effect of immature dendritic cells(iDCs on LPS-mediated maturation of iDCs phagocytizing allogeneic spleen lymphocytes after being treated bypsoralen plus ultraviolet A(PUVA. Methods　Bone marrow-derived DCs were obtained from bone marrow cells of C57BL/6 mice by co-cultivation with recombinant mouse IL-4 and GM-CSF. Spleenlymphocytes(SLP of BALB/c mice were isolated and transformed to PUVA-SLP by treatment with 8-methoxy PUVA irradiation.The bone marrow-derived iDCs of C57BL/6 were co-cultured with PUVA-SLP of BALB/c mice to obtain PUVA¬SLPDCs. After incubation, iDCs and PUVA-SP DCs were induced to maturation by LPS(10ng/ml,24h, and then they were analyzed by flow cytometry.At the same time,the concentrations of the immunoreactive proteins IL-12p70,IL-12p40andIL-10 in cell supernatants were determined by ELISA kits according to the manufacturer's recommendations. Results　PUVA-SLP DCs and iDCs were compared in terms of LPS responsiveness.The phenotype of iDCs(CD40,CD80, andCD86 was 50.58%, 66.29%, 71.20%, respectively, showed more rapid changes from immature to mature statein response to LPS stimulation compared with PUVA-SP DCs, the phenotype of which was 21.26%,38.50% and 39.78%, respectively(P0.05.PUVA-SPDCs secreted high levels of IL-10(435.6±13.9, but lowlevels of IL-12(p7018.56±1.3,p4015.22±1.2, as compared with those of iDCs (132.6±2.8, p70192.1±5.9, p40999.8±26.9, P<0.01 after LPS stimulation. Conclusions　Although PUVA-SLPDCs do not express as immature phenotype, they can be readily induced to differentiate into mature DCs in the presence of antigen or LPS. It may be suitable to use iDCs clinically in autoimmune diseases and transplantation.

EEG Driven tDCS Versus Bifrontal tDCS for Tinnitus

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De Ridder, Dirk; Vanneste, Sven

2012-01-01

Tinnitus is the perception of a sound in the absence of any objective physical sound source. Transcranial Direct Current Stimulation (tDCS) induces shifts in membrane resting potentials depending on the polarity of the stimulation: under the anode gamma band activity increases, whereas under the cathode the opposite occurs. Both single and multiple sessions of tDCS over the dorsolateral prefrontal cortex (DLPFC; anode over right DLPFC) yield a transient improvement in tinnitus intensity and t...

Radiographic study on the interrelation between bone deformans and condylar head position in the TMJ arthrosis

International Nuclear Information System (INIS)

You, Dong Soo

1981-01-01

The author analysed the interrelation between the morphologic changes of bone structures and the position of condylar head from the routine radiographs of 134 cases of the temporomandibular joint arthrosis. The frequencies of coincidence between the site of bone deformity and condylar head positional change were examined. Also, the positional changes of condylar head and the direction of condylar movement in relation to the kind of bone deformities were observed. The results obtained were as follows; 1. In 52.65 per cent of total cases, the site of positional change of condylar head was coincided with the site of bone deformans. The frequencies of the coincidence between these in the five items among seven items examined were above 53 per cent. From the results, it seems that the positional changes of condylar head were related with the morphological change of bone structure. 2. Eburnation and erosion revealed frequently positional changes in the opening and closing position of the mouth, although in the early stages of the TMJ arthrosis. 3. In the bone deformans, during open position of the mouth 44.81 per cent of total cases revealed backward movement and 37.74 per cent showed forward movement. In closed position of the mouth, downward movement was revealed in 35.23 percent of total cases and upward movement 28.41 percent of total cases.

Radiographic study on the interrelation between bone deformans and condylar head position in the TMJ arthrosis

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You, Dong Soo [Dept. of Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1981-11-15

The author analysed the interrelation between the morphologic changes of bone structures and the position of condylar head from the routine radiographs of 134 cases of the temporomandibular joint arthrosis. The frequencies of coincidence between the site of bone deformity and condylar head positional change were examined. Also, the positional changes of condylar head and the direction of condylar movement in relation to the kind of bone deformities were observed. The results obtained were as follows; 1. In 52.65 per cent of total cases, the site of positional change of condylar head was coincided with the site of bone deformans. The frequencies of the coincidence between these in the five items among seven items examined were above 53 per cent. From the results, it seems that the positional changes of condylar head were related with the morphological change of bone structure. 2. Eburnation and erosion revealed frequently positional changes in the opening and closing position of the mouth, although in the early stages of the TMJ arthrosis. 3. In the bone deformans, during open position of the mouth 44.81 per cent of total cases revealed backward movement and 37.74 per cent showed forward movement. In closed position of the mouth, downward movement was revealed in 35.23 percent of total cases and upward movement 28.41 percent of total cases.

Basic science of tDCS

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Michael A. Nitsche

2014-04-01

Full Text Available Neuroplasticity, and functional connectivity are important physiological derivates of cognition, and behaviour. Recently introduced non-invasive brain stimulation techniques are suited to induce, and modulate respective physiological alterations. One of these techniques is transcranial direct current stimulation (tDCS. Its primary mechanism of action is a polarity-dependent subthreshold shift of resting membrane potentials, the after-effects of stimulation depend on the glutamatergic system. Beyond these regional effects, tDCS has been shown recently to alter cortical, as well as cortico-subcortical functional network connectivity. This talk will give an overview about the physiological effects of tDCS, including animal data, and will cover functional consequences of tDCS. Furthermore, new developments with regard to optimization strategies, and the complex interaction of physiological and cognitive processes, will be presented and it will be discussed how tDCS relates to other non-invasive brain stimulation techniques, like transcranial magnetic stimulation (TMS, transcranial alternating current stimulation (tACS, and paired associative stimulation (PAS.

[Condylar hyperplasia: qualitative and quantitative study of temporomandibular joints remodeling before and after condylectomy].

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Rojare, Camille; Wojcik, Thomas; Coussens, Camille; Ferri, Joël; Pertuzon, Bruno; Raoul, Gwénaël

2014-06-01

This retrospective study aimed to evaluate bone remodeling of temporo-mandibular joints (TMJ) using computed tomography (CT) before and after condylectomy for condylar hyperplasia. TMJ bone remodeling was studied by comparing the pre and postoperative CT scan of ten patients. Qualitative evaluation was performed by two-dimensional analysis. Three-dimensional analysis superimpositions were done after digital condylar units isolation. Condylar volume modifications were measured and compared on both sides. Lastly, before and after surgery, we studied the radio-clinic correlations. After surgery, all the operated condyles developed a new cortical bone. We noticed also a thickening of the glenoid fossa. Surgical condylectomy leaded to a 43.5% volume reduction on the operated side and 2.14% on the controlateral side. On the controlateral side, most of abnormalities seen preoperatively disappeared after surgery. For two patients, the condylar resection took away over 80% of the initial volume. For these patients, we observed major radiologic modifications on the controlateral TMJ associated with symptoms of dysfunction. These problems did not worsen their quality of life. Both TMJ presented with bone remodelling after condylectomy. In condylar hyperplasia, condylectomy provides orthopaedic results on dysmorphia and removal of the pathological prechondroblastic zone. In the future, an earlier detection of this pathology may help the surgeon to treat in childhood. This would limit surgical excision and would avoid important dysmorphia. © EDP Sciences, SFODF, 2014.

Working memory capacity differentially influences responses to tDCS and HD-tDCS in a retro-cue task.

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Gözenman, Filiz; Berryhill, Marian E

2016-08-26

There is growing interest in non-invasive brain stimulation techniques. A drawback is that the relationship between stimulation and cognitive outcomes for various tasks are unknown. Transcranial direct current stimulation (tDCS) provides diffuse current spread, whereas high-definition tDCS (HD-tDCS) provides more targeted current. The direction of behavioral effects after tDCS can be difficult to predict in cognitive realms such as attention and working memory (WM). Previously, we showed that in low and high WM capacity groups tDCS modulates performance in nearly equal and opposite directions on a change detection task, with improvement for the high capacity participants alone. Here, we used the retro-cue paradigm to test attentional shifting among items in WM to investigate whether WM capacity (WMC) predicted different behavioral consequences during anodal tDCS or HD-tDCS to posterior parietal cortex (PPC). In two experiments, with 24 participants each, we used different stimulus categories (colored circles, letters) and stimulation sites (right, left PPC). The results showed a significant (Experiment 1) or trending (Experiment 2) WMC x stimulation interaction. Compared to tDCS, after HD-tDCS the retro-cueing benefit was significantly greater for the low WMC group but numerically worse for the high WMC group. These data highlight the importance of considering group differences when using non-invasive neurostimulation techniques. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Condylar bony changes in patients with temporomandibular disorders: a CBCT study

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Nah, Kyung Soo [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)

2012-09-15

Diagnosis of osteoarthritis most commonly depends on clinical and radiographic findings. The present study attempted to observe the bony changes in temporomandibular joint (TMJ) patients from all age groups. The first-visit clinical records and cone beam computed tomography (CBCT) data of 440 TMJs from 220 consecutive TMJ patients were reviewed retrospectively. The most frequent condylar bony change observed was sclerosis (133 joints, 30.2%) followed by surface erosion (129 joints, 29.3%), flattening of the articular surface (112 joints, 25.5%), and deviation in form (58 joints, 13.2%), which included 33 TMJs in a cane-shape, 16 with a lateral or medial pole depression, 6 with posterior condylar surface flattening, and 3 with a bifid-shaped condyle. Fifty-three joints (12.0%) showed hypoplastic condyles but only 1 joint showed hyperplasia. Osteophyte was found in 35 joints (8.0%) and subcortical cyst in 24 joints (5.5%), 5 of which had surface erosion as well. One hundred nineteen joints (27.0%) had only one kind of condylar bony change, 66 joints (15.0%) had two, 52 joints (11.8%) had three, 12 joints (5.0%) had four, and 6 joints (1.4%) had five kinds of condylar bony changes at the same time. Eighty-five (65.9%) of 129 joints with surface erosion had pain recorded at the chief complaint. With more widespread use of CBCT, more specific or detailed guidelines for osteoarthritis are needed.

Condylar bony changes in patients with temporomandibular disorders: a CBCT study

International Nuclear Information System (INIS)

Nah, Kyung Soo

2012-01-01

Diagnosis of osteoarthritis most commonly depends on clinical and radiographic findings. The present study attempted to observe the bony changes in temporomandibular joint (TMJ) patients from all age groups. The first-visit clinical records and cone beam computed tomography (CBCT) data of 440 TMJs from 220 consecutive TMJ patients were reviewed retrospectively. The most frequent condylar bony change observed was sclerosis (133 joints, 30.2%) followed by surface erosion (129 joints, 29.3%), flattening of the articular surface (112 joints, 25.5%), and deviation in form (58 joints, 13.2%), which included 33 TMJs in a cane-shape, 16 with a lateral or medial pole depression, 6 with posterior condylar surface flattening, and 3 with a bifid-shaped condyle. Fifty-three joints (12.0%) showed hypoplastic condyles but only 1 joint showed hyperplasia. Osteophyte was found in 35 joints (8.0%) and subcortical cyst in 24 joints (5.5%), 5 of which had surface erosion as well. One hundred nineteen joints (27.0%) had only one kind of condylar bony change, 66 joints (15.0%) had two, 52 joints (11.8%) had three, 12 joints (5.0%) had four, and 6 joints (1.4%) had five kinds of condylar bony changes at the same time. Eighty-five (65.9%) of 129 joints with surface erosion had pain recorded at the chief complaint. With more widespread use of CBCT, more specific or detailed guidelines for osteoarthritis are needed.

Radiographic cephalometry analysis of condylar position after bimaxillary osteotomy in patients with mandibular prognathism

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Miković Nikola D.

2016-01-01

Full Text Available Background/Aim. Postoperative condylar position is a substantial concern in surgical correction of mandibular prognathism. Orthognathic surgery may change condylar position and this is considered a contributing factor for early skeletal relapse and the induction of temporomandibular disorders. The purpose of this study was to evaluate changes in condylar position, and to correlate angular skeletal measurements following bimaxillary surgery. Methods. On profile teleradiographs of 21 patients with mandibular angular and linear parametres, the changes in condylar position, were measured during preoperative orthodontic treatment and 6 months after the surgical treatment. Results. A statistically significant difference in values between the groups was found. The most distal point on the head of condyle point (DI moved backward for 1.38 mm (p = 0.02, and the point of center of collum mandibulae point (DC moved backward for 1.52 mm (p = 0.007. The amount of upward movement of the point DI was 1.62 mm (p = 0.04. Conclusion. In the patients with mandibular prognathism, the condyles tend to migrate upward and forward six months after bimaxillary surgery.

Endoscope-assisted conservative condylectomy combined with orthognathic surgery in the treatment of mandibular condylar osteochondroma.

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Yu, Hongbo; Jiao, Feifei; Li, Biao; Zhang, Lei; Shen, Steve Guofang; Wang, Xudong

2014-07-01

Mandibular condylar osteochondroma (OC) results in asymmetric prognathism with facial morphologic and functional disturbance. The aim of this study was to explore the feasibility of endoscope-assisted conservative condylectomy combined with simultaneous orthognathic surgery in the treatment of condylar OC. Thirteen patients with OC of the mandibular condyle were enrolled in this study. With the aid of endoscope, condylar OC resection and conservative condylectomy were carried out via intraoral approach. A direct vision of the magnified and illuminated operative field was realized. Simultaneous orthognathic surgery was used to correct facial asymmetry and malocclusion. All patients healed uneventfully. No facial nerve injury and salivary fistula occurred. Facial symmetry and morphology were greatly improved, and stable occlusion was obtained in all cases. The patients showed no signs of recurrence and temporomandibular joint ankylosis in the 16 to 54 months of follow-up. Endoscope-assisted tumor resection and condylectomy combined with simultaneous orthognathic surgery provide us a valuable option in the treatment of mandibular condylar OC.

The closely related CD103+ dendritic cells (DCs and lymphoid-resident CD8+ DCs differ in their inflammatory functions.

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Zhijun Jiao

Full Text Available Migratory CD103+ and lymphoid-resident CD8+ dendritic cells (DCs share many attributes, such as dependence on the same transcription factors, cross-presenting ability and expression of certain surface molecules, such that it has been proposed they belong to a common sub-lineage. The functional diversity of the two DC types is nevertheless incompletely understood. Here we reveal that upon skin infection with herpes simplex virus, migratory CD103+ DCs from draining lymph nodes were more potent at inducing Th17 cytokine production by CD4+ T cells than CD8+ DCs. This superior capacity to drive Th17 responses was also evident in CD103+ DCs from uninfected mice. Their differential potency to induce Th17 differentiation was reflected by higher production of IL-1β and IL-6 by CD103+ DCs compared with CD8+ DCs upon stimulation. The two types of DCs from isolated lymph nodes also differ in expression of certain pattern recognition receptors. Furthermore, elevated levels of GM-CSF, typical of those found in inflammation, substantially increased the pool size of CD103+ DCs in lymph nodes and skin. We argue that varied levels of GM-CSF may explain the contrasting reports regarding the positive role of GM-CSF in regulating development of CD103+ DCs. Together, we find that these two developmentally closely-related DC subsets display functional differences and that GM-CSF has differential effect on the two types of DCs.

Transcutaneous Spinal Direct Current Stimulation (tsDCS

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Filippo eCogiamanian

2012-07-01

Full Text Available In the past ten years renewed interest has centered on non-invasive transcutaneous weak direct currents applied over the scalp to modulate cortical excitability (brain polarization or transcranial direct current stimulation, tDCS. Extensive literature shows that tDCS induces marked changes in cortical excitability that outlast stimulation.Aiming at developing a new, non invasive, approach to spinal cord neuromodulation we assessed the after-effects of thoracic transcutaneous spinal DC stimulation (tsDCS on somatosensory potentials (SEPs evoked in healthy subjects by posterior tibial nerve (PTN stimulation. Our findings showed that thoracic anodal tsDCS depresses the cervico-medullary PTN-SEP component (P30 without eliciting adverse effects. tsDCS also modulates post-activation H-reflex dynamics. Later works further confirmed that transcutaneous electric fields modulate spinal cord function. Subsequent studies in our laboratory showed that tsDCS modulates the flexion reflex in the human lower limb. Besides influencing the laser evoked potentials, tsDCS increases pain tolerance in healthy subjects. Hence, though the underlying mechanisms remain speculative, tsDCS modulates activity in lemniscal, spinothalamic and segmental motor systems.Here we review currently available experimental evidence that non-invasive spinal cord stimulation influences spinal function in humans and argue that, by focally modulating spinal excitability, tsDCS could provide a novel therapeutic tool complementary to drugs and invasive spinal cord stimulation in managing various pathologic conditions, including pain.

Transmasseteric anterior parotid approach for condylar fractures: experience of 129 cases.

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Narayanan, Vinod; Ramadorai, Ashok; Ravi, Poornima; Nirvikalpa, Natarajan

2012-07-01

We have evaluated the transmasseteric anterior parotid (TMAP) approach in the treatment of 163 condylar fractures in 129 patients. Ninety-five patients presented with unilateral, and 34 with bilateral, fractures. The inclusion criteria were patient's choice for open reduction and internal fixation, displaced unilateral condylar fractures with occlusal derangement, and displaced bilateral condylar fractures with anterior open bite. Mean (SD) maximum interincisal opening after 3 months was 44(5)mm. There were no differences in lateral movements during the reviews 6 weeks and 3 months postoperatively. Protrusive movement at the end of 3 months was 7(2)mm. All patients achieved functional occlusion identical to the pretraumatic occlusion and good reduction of the condyles. No patient developed temporary or permanent facial palsy, sialocele, salivary fistula, or Frey syndrome. The mean (SD) operating time was 46(11)min. The TMAP approach avoids the complications of incision of the parotid gland, minimises the risk of facial nerve palsy, and offers excellent access to the fractured condyle. Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The Relationship of the Facial Nerve to the Condylar Process: A Cadaveric Study with Implications for Open Reduction Internal Fixation

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H. P. Barham

2015-01-01

Full Text Available Introduction. The mandibular condyle is the most common site of mandibular fracture. Surgical treatment of condylar fractures by open reduction and internal fixation (ORIF demands direct visualization of the fracture. This project aimed to investigate the anatomic relationship of the tragus to the facial nerve and condylar process. Materials and Methods. Twelve fresh hemicadavers heads were used. An extended retromandibular/preauricular approach was utilized, with the incision being based parallel to the posterior edge of the ramus. Measurements were obtained from the tragus to the facial nerve and condylar process. Results. The temporozygomatic division of the facial nerve was encountered during each approach, crossing the mandible at the condylar neck. The mean tissue depth separating the facial nerve from the condylar neck was 5.5 mm (range: 3.5 mm–7 mm, SD 1.2 mm. The upper division of the facial nerve crossed the posterior border of the condylar process on average 2.31 cm (SD 0.10 cm anterior to the tragus. Conclusions. This study suggests that the temporozygomatic division of the facial nerve will be encountered in most approaches to the condylar process. As visualization of the relationship of the facial nerve to condyle is often limited, recognition that, on average, 5.5 mm of tissue separates condylar process from nerve should help reduce the incidence of facial nerve injury during this procedure.

Condylar position on the lateral individualized corrected tomography in internal derangement of temporomandibular joint

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Kim, Keun Min; Hwang, Eui Hwan; Lee, Sang Rae [College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

2002-06-15

To examine the possible relationship between condylar position and disk displacement in the temporomandibular joint. 79 temporomandibular joints in 40 patients having temporomandibular disorders were classified into three categories: no disk displacement (NDD), disk displacement with reduction (DDWR), and disk displacement without reduction (DDWOR). Disk positions were assessed from clinical and MRI findings. The relationship between the three categories and condylar positions was evaluated using lateral individualized corrected tomography. Clinical findings regarding the relationship between condyle and disk positions having anterior, centric, and posterior positions were 27%, 27%, and 46%, respectively, in NDD, 43%, 17%, and 40%, respectively, in DDWR, and 44%, 22%, and 34%, respectively, in DDWOR. There were no significant differences in condylar positions between each of the groups (P>0.05). In the relationship between condyle and disk positions with MRI findings, anterior, centric, and posterior positions were 38%, 38%, and 24%, respectively, in NDD, 29%, 21%, and 50%, respectively, in DDWR, and 44%, 9%, and 47% respectively, in DDWOR. There were significant differences in the condylar positions when MRI was utilized (P<0.05). There was a significant correlation between the condyle and disk positions with MRI findings on lateral individualized corrected tomography.

Surgical treatment of adolescent internal condylar resorption (AICR) with articular disc repositioning and orthognathic surgery in the growing patient--a pilot study.

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Bodine, Trevor P; Wolford, Larry M; Araujo, Eustaquio; Oliver, Donald R; Buschang, Peter H

2016-01-01

The aim of this study was to better understand how surgical repositioning and stabilization of anteriorly displaced articular discs using the Mitek mini-anchor technique affects condylar growth in growing patients with adolescent internal condylar resorption (AICR). Twenty-two adolescent patients diagnosed with AICR and anterior temporomandibular disc displacement were compared to untreated control subjects without AICR matched for age, sex, and Angle classification. Pre-surgical (T1 and T2) and post-surgical (T3 and T4) mandibular tracings were superimposed on natural stable structures to evaluate the horizontal, vertical, and total changes in the position of condylion. The treated group showed an overall decrease in condylar height pre-surgically and statistically significant changes in condylar growth direction between the pre- and post-surgical observation periods. Pre-surgically, the treated group showed significantly more posterior condylar growth than the control group; they also showed inferior condylar growth, while the controls showed superior growth. Controls and patients in the treated group showed no significant differences in condylar growth post-surgically. Adolescent patients diagnosed with AICR and anterior disc displacement treated with mandibular ramus and maxillary osteotomies, along with Mitek anchors to reposition internally deranged discs, showed post-surgical normalization of condylar growth.

Surgical treatment of adolescent internal condylar resorption (AICR with articular disc repositioning and orthognathic surgery in the growing patient—a pilot study

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Trevor P. Bodine

2016-01-01

Full Text Available Abstract Background The aim of this study was to better understand how surgical repositioning and stabilization of anteriorly displaced articular discs using the Mitek mini-anchor technique affects condylar growth in growing patients with adolescent internal condylar resorption (AICR. Methods Twenty-two adolescent patients diagnosed with AICR and anterior temporomandibular disc displacement were compared to untreated control subjects without AICR matched for age, sex, and Angle classification. Pre-surgical (T1 and T2 and post-surgical (T3 and T4 mandibular tracings were superimposed on natural stable structures to evaluate the horizontal, vertical, and total changes in the position of condylion. Results The treated group showed an overall decrease in condylar height pre-surgically and statistically significant changes in condylar growth direction between the pre- and post-surgical observation periods. Pre-surgically, the treated group showed significantly more posterior condylar growth than the control group; they also showed inferior condylar growth, while the controls showed superior growth. Controls and patients in the treated group showed no significant differences in condylar growth post-surgically. Conclusions Adolescent patients diagnosed with AICR and anterior disc displacement treated with mandibular ramus and maxillary osteotomies, along with Mitek anchors to reposition internally deranged discs, showed post-surgical normalization of condylar growth.

Hyaline cartilage cells outperform mandibular condylar cartilage cells in a TMJ fibrocartilage tissue engineering application.

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Wang, L; Lazebnik, M; Detamore, M S

2009-03-01

To compare temporomandibular joint (TMJ) condylar cartilage cells in vitro to hyaline cartilage cells cultured in a three-dimensional (3D) environment for tissue engineering of mandibular condylar cartilage. Mandibular condylar cartilage and hyaline cartilage cells were harvested from pigs and cultured for 6 weeks in polyglycolic acid (PGA) scaffolds. Both types of cells were treated with glucosamine sulfate (0.4 mM), insulin-like growth factor-I (IGF-I) (100 ng/ml) and their combination. At weeks 0 and 6, cell number, glycosaminoglycan (GAG) and collagen content were determined, types I and II collagen were visualized by immunohistochemistry and GAGs were visualized by histology. Hyaline cartilage cells produced from half an order to a full order of magnitude more GAGs and collagen than mandibular condylar cartilage cells in 3D culture. IGF-I was a highly effective signal for biosynthesis with hyaline cartilage cells, while glucosamine sulfate decreased cell proliferation and biosynthesis with both types of cells. In vitro culture of TMJ condylar cartilage cells produced a fibrous tissue with predominantly type I collagen, while hyaline cartilage cells formed a fibrocartilage-like tissue with types I and II collagen. The combination of IGF and glucosamine had a synergistic effect on maintaining the phenotype of TMJ condylar cells to generate both types I and II collagen. Given the superior biosynthetic activity by hyaline cartilage cells and the practical surgical limitations of harvesting cells from the TMJ of a patient requiring TMJ reconstruction, cartilage cells from elsewhere in the body may be a potentially better alternative to cells harvested from the TMJ for TMJ tissue engineering. This finding may also apply to other fibrocartilages such as the intervertebral disc and knee meniscus in applications where a mature cartilage cell source is desired.

Is Motor Learning Mediated by tDCS Intensity?

OpenAIRE

Cuypers, Koen; Leenus, Daphnie J. F.; van den Berg, Femke E.; Nitsche, Michael A.; Thijs, Herbert; Wenderoth, Nicole; Meesen, Raf L. J.

2013-01-01

Although tDCS has been shown to improve motor learning, previous studies reported rather small effects. Since physiological effects of tDCS depend on intensity, the present study evaluated this parameter in order to enhance the effect of tDCS on skill acquisition. The effect of different stimulation intensities of anodal tDCS (atDCS) was investigated in a double blind, sham controlled crossover design. In each condition, thirteen healthy subjects were instructed to perform a unimanual motor (...

Spatio-temporal expression patterns of Wnt signaling pathway during the development of temporomandibular condylar cartilage.

Science.gov (United States)

Chen, Kan; Quan, Huixin; Chen, Gang; Xiao, Di

2017-11-01

There is a growing body of evidence supporting the involvement of the Wnt signaling pathway in various aspects of skeletal and joint development; however, it is unclear whether it is involved in the process of temporomandibular joint development. In order to clarify this issue, we examined the spatio-temporal distribution of mRNAs and proteins of the Wnt family during the formation of the mandibular condylar cartilage at the prenatal and postnatal stages. An in situ hybridization test revealed no mRNAs of β-catenin and Axin2 during early mesenchymal condensation; the ligands surveyed in this study (including Wnt-4, 5a, and 9a) were clearly detected at various ranges of expression, mainly in the condylar blastema and later distinct cartilaginous layers. Apart from β-catenin and Axin2, the Wnt family members surveyed in this study, including Lef-1, were found to be immunopositive during early chondrogenesis in the condylar cartilage at E14.5. After distinct chondrocyte layers were identified within the cartilage at E16.5, the expression of the Wnt signaling members was different and mainly restricted to proliferating cells and mineralized hypertrophic chondrocytes. In the adult mandibular condylar cartilage, the Wnt-4 mRNA, as well as the Wnt-4 and Wnt-9a proteins, was not observed. Our findings demonstrated that the Wnt signaling pathway was associated with the development of mandibular condylar cartilage. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Screw Configuration on the Preload Force of Implant-Abutment Screws.

Science.gov (United States)

Zipprich, Holger; Rathe, Florian; Pinz, Sören; Schlotmann, Luca; Lauer, Hans-Christoph; Ratka, Christoph

The aim of this study was to investigate the effects of tightening torque, screw head angle, and thread number on the preload force of abutment screws. The test specimens consisted of three self-manufactured components (ie, a thread sleeve serving as an implant analog, an abutment analog, and an abutment screw). The abutment screws were fabricated with metric M1.6 external threads. The thread number varied between one and seven threads. The screw head angles were produced in eight varying angles (30 to 180 degrees). A sensor unit simultaneously measured the preload force of the screw and the torsion moment inside the screw shank. The tightening of the screw with the torque wrench was performed in five steps (15 to 35 Ncm). The torque wrench was calibrated before each step. Only the tightening torque and screw head angle affected the resulting preload force of the implant-abutment connection. The thread number had no effect. There was an approximately linear correlation between tightening torque and preload force. The tightening torque and screw head angle were the only study parameters that affected the resulting preload force of the abutment screw. The results obtained from this experiment are valid only for a single torque condition. Further investigations are needed that analyze other parameters that affect preload force. Once these parameters are known, it will add value for a strong, but detachable connection between the implant and abutment. Short implants and flat-to-flat connections especially will benefit significantly from this knowledge.

Twenty-degree-tilt radiography for evaluation of lateral humeral condylar fracture in children

International Nuclear Information System (INIS)

Imada, Hideaki; Tanaka, Ryuji; Itoh, Yohei; Kishi, Kazuhiko

2010-01-01

To investigate the efficacy of '20 -tilt anteroposterior (A-P) radiography' in the assessment of lateral condylar fractures of the distal humerus. Eighteen children with lateral humeral condylar fractures were studied. Every child underwent conventional A-P and lateral radiography, and six children underwent multi-detector computed tomography (MDCT). For the investigation of 20 -tilt radiography, ten children with lateral humeral condylar fractures had conventional and 20 -tilt A-P and lateral radiography both preoperatively and postoperatively. Fragment dislocation was measured at the lateral and medial margins of the fracture on both the conventional A-P and 20 -tilt A-P radiographs. The lateral condylar fragment was triangular and was most prominent posteriorly. The fracture line was typically tilted approximately 20 to a reference line perpendicular to the long axis of the humerus in the lateral view. The extent of dislocation at the lateral and medial margins of the fracture site by 20 -tilt A-P radiography (9.3 ± 3.6 mm and 5.6 ± 2.5 mm) was significantly wider than that measured by the conventional method (6.8 ± 4.1 mm and 2.0 ± 1.5 mm), which may influence treatment. Twenty-degree-tilt A-P radiography may more precisely demonstrate fragment dislocation than standard radiographs and may influence patient treatment. (orig.)

Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

OpenAIRE

Choi, Kang-Young; Yang, Jung-Dug; Chung, Ho-Yun; Cho, Byung-Chae

2012-01-01

The incidence of condylar fractures is high, but the management of fractures of the mandibular condyle continues to be controversial. Historically, maxillomandibular fixation, external fixation, and surgical splints with internal fixation systems were the techniques commonly used in the treatment of the fractured mandible. Condylar fractures can be extracapsular or intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on the age of the patient, the co-existence of ...

On the analysis of condylar path versus real motion of the temporomandibular joint: application for Sicat Function.

Science.gov (United States)

Kordaß, Bernd; Ruge, Sebastian

2015-01-01

Analysis of temporomandibular joint (TMJ) function using condylar path tracings is a challenge in functionally oriented dentistry. In most cases, reference points on the skin surface over the TMJ region are defined as "arbitrary", "individual" or "kinematic" condylar hinge axis points, which are displayed as "condylar paths" in motion. To what extent these reference points represent the actual condylar paths in each individual patient is ultimately unclear because the geometric relationship of the actual condyle to the selected reference point is usually unknown. Depending on the location of the point on the condyle and the centers of rotation of mandibular movement, these trajectories can vary greatly during combined rotational and sliding movements (eg, opening and closing movements of the mandible); this represents a grid of points located in the vicinity of the TMJ. To record the actual condylar path as the movement trajectory of a given point (eg, the condylar center), technological solutions are needed with which to link the tracing technology with the appropriate imaging technology capable of scanning the condyle, including the points of interest, and displaying them in real dynamic motion. Sicat Function (Sicat, D-Bonn) is such a solution. Sicat Function links cone beam computed tomography (CBCT) scans (made using the Galileos CBCT scanner; Sirona, Bensheim, Germany) with ultrasound-based, three-dimensional (3D) functional jaw movement recordings of the mandible (made using the JMT+ Jaw Motion Tracker; Sicat, Bonn, Germany). Digital images of the dental arches acquired with the intraoral scanner Cerec system (Sirona) can also be superimposed. This results in the generation of a 3D model of the bony mandible, including the TMJ, which reproduces the 3D real dynamic movement of the condyles simultaneously with that of the condylar paths at defined points (with the condylar centers being a particular point of interest). Sicat Function is an integrated, digital

Open reduction and internal fixation of dislocated condylar fractures in children: long-term clinical and radiologic outcomes.

Science.gov (United States)

Deleyiannis, Frederic W-B; Vecchione, Lisa; Martin, Brian; Jiang, Shao; Sotereanos, George

2006-11-01

The purpose of this study was to investigate the long-term clinical and radiologic outcomes of treating dislocated condylar fractures sustained in childhood with open reduction and internal fixation (ORIF). Six children 14 years or younger with a condylar neck or subcondylar fracture with dislocation of the condyle from the glenoid fossa were treated with ORIF. Patients were followed for 27 to 92 months post-ORIF (mean: 67.6 months) with routine clinical and radiologic examinations. On the dislocated side, all patients radiographically showed signs of remodeling of the condylar process and shortening of the ramus. Subsequent to their fractures, 3 patients were classified with Angle class II malocclusion, retrognathism, and deviation of the mandibular symphysis. Four patients had objective and/or subjective signs of temporomandibular (TMJ) dysfunction. Until open surgery demonstrates a consistent functional advantage, nonsurgical management should be considered the first treatment option for the dislocated pediatric condylar fracture.

A radiographic study on the condylar position in temporomandibular joint dysfunction patients

International Nuclear Information System (INIS)

Bang, Seo Howan; Kim, Jae Duck

1987-01-01

The author obtained the transcranial-oblique lateral radiograms from 78 patients (26 male, 52 female) with temporom andibular dysfunction problem. And then, the author analyzed the dimensional changes of the TMJ space on centric occlusion, horizontal condylar movement and antero-posterior positional relationship of condyle to the articular eminence on 2.54 cm mouth opening with clicking, TMJ pain and mouth opening limitation respectively, which were the symptoms of the temporomandibular joint pain dysfunction problem, and compared these data with control group. The results were as follow: 1. In centric occlusion, anterior and posterior TMJ space of experimental group was slightly lesser than those of the control group, also superior TMJ space of experimental group was significantly lesser than that of the control group. (p 2. In 2.54 cm mouth opening, the condylar horizontal movement and the antero-posterior positional relationship to the articular eminence were significantly lesser than those of the control group. (p 3. Examined experimental group, the degree of condylar horizontal movement of affected side was lesser than that of the normal side in 2.54 cm mouth opening.

ATLAS DAQ/HLT rack DCS

International Nuclear Information System (INIS)

Ermoline, Yuri; Burckhart, Helfried; Francis, David; Wickens, Frederick J.

2007-01-01

The ATLAS Detector Control System (DCS) group provides a set of standard tools, used by subsystems to implement their local control systems. The ATLAS Data Acquisition and High Level Trigger (DAQ/HLT) rack DCS provides monitoring of the environmental parameters (air temperatures, humidity, etc.). The DAQ/HLT racks are located in the underground counting room (20 racks) and in the surface building (100 racks). The rack DCS is based on standard ATLAS tools and integrated into overall operation of the experiment. The implementation is based on the commercial control package and additional components, developed by CERN Joint Controls Project Framework. The prototype implementation and measurements are presented

Evaluation of Mandibular Condylar Changes in Patients Following ...

African Journals Online (AJOL)

orthognathic surgery, as well as to assess what factors may have contributed to ... study that females of relative low age (<18 years) appeared to be a high‑risk ... Maharaja Ganga Singh Dental College and Research Centre, ... cause alteration of the position of the condyle in the ... of condylar shape and decrease in mass.

Correlation of the Condylar Guidance Obtained by Protrusive Interocclusal Record and Panoramic Radiographs in Completely Edentulous Patients: An in Vivo Study

Directory of Open Access Journals (Sweden)

Khyati Shah

2014-01-01

Results: The results showed statistically significant difference between the condylar guidance values obtained from Orthopantomograph (Radiograph and the condylar guidance values obtained at the stage of jaw relation. Conclusion: Within the limitations of the study, it can be concluded that the condylar guidance values obtained from the Radiographs were higher than those obtained at the stage of jaw relation recording stage.

Positioning device for screwing or unscrewing screw nut

International Nuclear Information System (INIS)

Sevelinge, G.

1987-01-01

This automatic positioning device for screwing or unscrewing a screw nut on a closure stud has a drawed socket and means for axially centre and angularly by wedge the socket on the closure stud and generate a continuous spiral between the socket and the closure stud [fr

High condylectomy for the treatment of mandibular condylar hyperplasia

DEFF Research Database (Denmark)

Ghawsi, Sodaba; Aagaard, Esben; Thygesen, Torben Henrik

2016-01-01

Mandibular condylar hyperplasia (MCH) is a rare, idiopathic disorder, which can cause both functional and aesthetic problems. MCH has often been described in the literature, but a comprehensive analysis of the current literature on MCH has not been undertaken. This study presents a systematic rev...

Bone changes in the condylar head and mandibular fossa in patients with temporomandibular disorders. Helical CT observation

International Nuclear Information System (INIS)

Shimahara, Satoru; Ariyoshi, Yasunori; Kimura, Yoshihiro; Shimahara, Masashi

2011-01-01

In the present study, we investigated whether bone changes are present in sites impossible to observe by panoramic X-ray and Schuller's X-ray examination, namely the medial of the condylar head and mandibular fossa, in patients with type IV temporomandibular joint disorders. We observed the articular fossa using computed tomography, which is able to obtain detailed 3-dimensional information, in patients with type IV temporomandibular disorders. We examined 120 joints of 60 patiens who visited the Department of Oral Surgery, Osaka Medical College Hospital. Each condylar head was clearly visualized in panoramic X-ray and Schuller's X-ray examination findings, and shown to have possible changes unilaterally. Each joint was diagnosed as type IV, according to the diagnostic guidelines set by Japanese Society for Temporomandibular Joint, and further examined using helical CT. Changes in condylar head; We concluded that bone changes were present with considerable probability in the medial of condylar head in a manner similar to those found in the lateral and center of joints with type IV temporomandibular disorders. Changes in mandibular fossa; The bone changes occurred in various locations of the mandibular fossa, while they appeared significantly more frequently in the condylar head. We think that our finding will contribute to development of treatment strategies for temporomandibular disorders, as they clarify bone changes in sites previously unreported. (author)

Project managing your simulator DCS upgrade

International Nuclear Information System (INIS)

Carr, S.

2006-01-01

The intention of this paper is to provide helpful information and tips for the purchaser with regard to the project management of a DCS upgrade for an existing nuclear power station operator-training simulator. This paper was written shortly after STS Powergen completed two nuclear power station simulator DCS projects in the USA. Areas covered by this paper are: - Contractual documents and arrangements; - Licence and Escrow agreements; - Liquidated damages; - Project management; - Project schedules and resources; - Monitoring progress; - Defect reporting; - DCS automation code; - Access to proprietary information; - Tips for project meetings; - Testing; - Cultural issues; - Training

Association between condylar morphology and changes in bony microstructure and subsynovial inflammation in experimental temporomandibular joint arthritis

DEFF Research Database (Denmark)

Kristensen, Kasper Dahl; Hauge, Ellen Margrethe; Dalstra, Michel

2010-01-01

Association between condylar morphology and changes in bony microstructure and subsynovial inflammation in experimental temporomandibular joint arthritis. 86. Congress of the European Orthodontic Society, Slovenien, 2010.......Association between condylar morphology and changes in bony microstructure and subsynovial inflammation in experimental temporomandibular joint arthritis. 86. Congress of the European Orthodontic Society, Slovenien, 2010....

Positional change of the condylar heads after wearing complete denture on dental cone beam CT

International Nuclear Information System (INIS)

Lee, Bong Ho; Kim, Jae Duk; Chung, Chae Heon

2008-01-01

The aim of this study was to evaluate the change in the position of the mandibular condyle within articular fossa by a CBCT after wearing complete denture (CD). CBCT of 34 temporomandibular joints were taken from 9 male and 8 female patients with CB Mercuray TM (Hitachi, Japan) before and after wearing a CD for rehabilitation. Position of mandibular condyle within articular fossa at centric occlusion was evaluated with Vimplant2.0 TM (CyberMed, Korea) on the central parasagittal view and curved panoramic coronal view of the condylar head. A statistical evaluation was done with SPSS. The range of anteroposterior positional rate (AP) of condylar head within articular fossa was -16-5 and -10-12 respectively on the right and left sides. Before wearing CD, the AP rate showed discrepancy between right and left sides (p<0.05). After wearing CD, both condyles showed a tendency to decrease in posterior condylar position (right side; p<0.05). The average discrepancy between right and left side in mediolateral positional rate (MD) was 15.5 and 4.5 respectively before and after wearing CD. The improvement was observed in mediolateral relationship of both condylar heads after wearing CD (p<0.01). Before wearing CD, the average horizontal angle of long axis of condylar head was 79.6 ± 2.7 .deg. C and 80.1 ± 5.7 .deg. C respectively on the right and left sides. After wearing CD, both condyles were rotated in the same direction in average on axial plane. We observed with CBCT the significant clinical evidence in case of positional change of mandibular condyle after wearing complete denture.

Technical Support for the development of DCS

International Nuclear Information System (INIS)

Oh, In Seok; Lee, Cheol Kwon; Kim, Dong Hoon; Kim, Jung Taek; Hwang, In Koo; Park, Jae Chang; Lee, Dong Young; Park, Won Man

2008-05-01

The objective of this project is to provide a technical support to Woori Tech Co. in its design and manufacture process of the DCS as a part of KNICS development program to promote the technology self-reliance for non-safety equipment for NPPs(Nuclear Power Plants). We support Woori Tech Co. to develop a DCS which satisfies the requirements for Shinkori 3 and 4 NPPs in the aspects of reliability, applicability and technical competitiveness. As the results of this project the following items were developed and/or implemented; · Design basis and requirements for a DCS system · Design requirements for control communication networks · Architecture of control networks · Design requirements of EWS(Engineering Workstation) · Plan of software verification and validation · Operation display design · Soft control functions · Application development tools of DCS · Analysis and V/V activities on DCS control network protocols · Software verification and validation and documentation guidelines · User manual documents

Tapping insertional torque allows prediction for better pedicle screw fixation and optimal screw size selection.

Science.gov (United States)

Helgeson, Melvin D; Kang, Daniel G; Lehman, Ronald A; Dmitriev, Anton E; Luhmann, Scott J

2013-08-01

There is currently no reliable technique for intraoperative assessment of pedicle screw fixation strength and optimal screw size. Several studies have evaluated pedicle screw insertional torque (IT) and its direct correlation with pullout strength. However, there is limited clinical application with pedicle screw IT as it must be measured during screw placement and rarely causes the spine surgeon to change screw size. To date, no study has evaluated tapping IT, which precedes screw insertion, and its ability to predict pedicle screw pullout strength. The objective of this study was to investigate tapping IT and its ability to predict pedicle screw pullout strength and optimal screw size. In vitro human cadaveric biomechanical analysis. Twenty fresh-frozen human cadaveric thoracic vertebral levels were prepared and dual-energy radiographic absorptiometry scanned for bone mineral density (BMD). All specimens were osteoporotic with a mean BMD of 0.60 ± 0.07 g/cm(2). Five specimens (n=10) were used to perform a pilot study, as there were no previously established values for optimal tapping IT. Each pedicle during the pilot study was measured using a digital caliper as well as computed tomography measurements, and the optimal screw size was determined to be equal to or the first size smaller than the pedicle diameter. The optimal tap size was then selected as the tap diameter 1 mm smaller than the optimal screw size. During optimal tap size insertion, all peak tapping IT values were found to be between 2 in-lbs and 3 in-lbs. Therefore, the threshold tapping IT value for optimal pedicle screw and tap size was determined to be 2.5 in-lbs, and a comparison tapping IT value of 1.5 in-lbs was selected. Next, 15 test specimens (n=30) were measured with digital calipers, probed, tapped, and instrumented using a paired comparison between the two threshold tapping IT values (Group 1: 1.5 in-lbs; Group 2: 2.5 in-lbs), randomly assigned to the left or right pedicle on each

Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System.

Science.gov (United States)

Sim, Bo Kyun; Kim, Bongju; Kim, Min Jeong; Jeong, Guk Hyun; Ju, Kyung Won; Shin, Yoo Jin; Kim, Man Yong; Lee, Jong-Ho

2017-01-01

The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA) and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA.

[Fracture of implant abutment screws and removal of a remaining screw piece

NARCIS (Netherlands)

Broeke, S.M. van den; Baat, C. de

2008-01-01

Fracture of the implant abutment screws is a complication which can render an implant useless. The prevalence of abutment screw fracture does not exceed 2.5% after 10 years. Causes are loosening of implant abutment screw, too few, too short or too narrow implants, implants not inserted perpendicular

Effect of Repeated Screw Joint Closing and Opening Cycles and Cyclic Loading on Abutment Screw Removal Torque and Screw Thread Morphology: Scanning Electron Microscopy Evaluation.

Science.gov (United States)

Arshad, Mahnaz; Mahgoli, Hosseinali; Payaminia, Leila

To evaluate the effect of repeated screw joint closing and opening cycles and cyclic loading on abutment screw removal torque and screw thread morphology using scanning electron microscopy (SEM). Three groups (n = 10 in each group) of implant-abutment-abutment screw assemblies were created. There were also 10 extra abutment screws as new screws in group 3. The abutment screws were tightened to 12 Ncm with an electronic torque meter; then they were removed and removal torque values were recorded. This sequence was repeated 5 times for group 1 and 15 times for groups 2 and 3. The same screws in groups 1 and 2 and the new screws in group 3 were then tightened to 12 Ncm; this was also followed by screw tightening to 30 Ncm and retightening to 30 Ncm 15 minutes later. Removal torque measurements were performed after screws were subjected to cyclic loading (0.5 × 10⁶ cycles; 1 Hz; 75 N). Moreover, the surface topography of one screw from each group before and after cyclic loading was evaluated with SEM and compared with an unused screw. All groups exhibited reduced removal torque values in comparison to insertion torque in each cycle. However, there was a steady trend of torque loss in each group. A comparison of the last cycle of the groups before loading showed significantly greater torque loss value in the 15th cycle of groups 2 and 3 compared with the fifth cycle of group 1 (P abutment is definitively placed.

DCS emulator development for the ACR-1000 simulator

International Nuclear Information System (INIS)

Nakashima, Y.; Trueman, R.; Ishii, K.

2010-01-01

Nuclear Power Plant (NPP) simulators are the main means for operator training and as such are a crucial part of the NPP operation life-cycle. Hitachi, Ltd., Information and Control Systems Company (henceforth 'Hitachi') is the preferred DCS and DCS emulator developer and supplier for the ACR-1000 NPP control system. Hitachi's concept for the DCS (distributed control system) portion of the ACR-1000 simulator is 'total emulation of the DCS' by software. This paper will review the current status of the technical development and the major project milestones. (author)

[Research progress of mechanism of hypoxia-inducible factor-1α signaling pathway in condylar cartilage growth and remodeling].

Science.gov (United States)

Gaoli, Xu; Lili, Wu; Zhiwu, Wu; Zhiyuan, Gu

2016-12-01

The condylar cartilage was adapted to hypoxic conditions in vivo. However, condylar cartilage cells exposed in normoxia in vitro affect the chondrocyte phenotype and cartilage matrix formation. This condition also resulted in great difficulty in chondrocyte research. Culturing chondrocyte should be simulated in in vivo hypoxia environment as much as possible. The hypoxia-inducible factor-1α (HIF-1α) demonstrates an important transcription factor of adaptive response to hypoxic conditions. HIF-1α also plays an active role in maintaining homeostasis and function of chondrocytes. This review summarized current knowledge of the HIF-1α structure, signaling pathway, and mechanism of HIF-1α in the condylar cartilage repair.

Cellular and Matrix Response of the Mandibular Condylar Cartilage to Botulinum Toxin.

Directory of Open Access Journals (Sweden)

Eliane H Dutra

Full Text Available To evaluate the cellular and matrix effects of botulinum toxin type A (Botox on mandibular condylar cartilage (MCC and subchondral bone.Botox (0.3 unit was injected into the right masseter of 5-week-old transgenic mice (Col10a1-RFPcherry at day 1. Left side masseter was used as intra-animal control. The following bone labels were intraperitoneally injected: calcein at day 7, alizarin red at day 14 and calcein at day 21. In addition, EdU was injected 48 and 24 hours before sacrifice. Mice were sacrificed 30 days after Botox injection. Experimental and control side mandibles were dissected and examined by x-ray imaging and micro-CT. Subsequently, MCC along with the subchondral bone was sectioned and stained with tartrate resistant acid phosphatase (TRAP, EdU, TUNEL, alkaline phosphatase, toluidine blue and safranin O. In addition, we performed immunohistochemistry for pSMAD and VEGF.Bone volume fraction, tissue density and trabecular thickness were significantly decreased on the right side of the subchondral bone and mineralized cartilage (Botox was injected when compared to the left side. There was no significant difference in the mandibular length and condylar head length; however, the condylar width was significantly decreased after Botox injection. Our histology showed decreased numbers of Col10a1 expressing cells, decreased cell proliferation and increased cell apoptosis in the subchondral bone and mandibular condylar cartilage, decreased TRAP activity and mineralization of Botox injected side cartilage and subchondral bone. Furthermore, we observed reduced proteoglycan and glycosaminoglycan distribution and decreased expression of pSMAD 1/5/8 and VEGF in the MCC of the Botox injected side in comparison to control side.Injection of Botox in masseter muscle leads to decreased mineralization and matrix deposition, reduced chondrocyte proliferation and differentiation and increased cell apoptosis in the MCC and subchondral bone.

Morphometric evaluation of condylar cartilage of growing rats in response to mandibular retractive forces

Directory of Open Access Journals (Sweden)

Milena Peixoto Nogueira de Sá

2013-08-01

Full Text Available INTRODUCTION: The mandibular condylar surface is made up of four layers, i.e., an external layer composed of dense connective tissue, followed by a layer of undifferentiated cells, hyaline cartilage and bone. Few studies have demonstrated the behavior of the condylar cartilage when the mandible is positioned posteriorly, as in treatments for correcting functional Class III malocclusion. OBJECTIVE: The aim of this study was to assess the morphologic and histological aspects of rat condyles in response to posterior positioning of the mandible. METHODS: Thirty five-week-old male Wistar rats were selected and randomly divided into two groups: A control group (C and an experimental group (E which received devices for inducing mandibular retrusion. The animals were euthanized at time intervals of 7, 21 and 30 days after the experiment had began. For histological analysis, total condylar thickness was measured, including the proliferative, hyaline and hypertrophic layers, as well as each layer separately, totaling 30 measurements for each parameter of each animal. RESULTS: The greatest difference in cartilage thickness was observed in 21 days, although different levels were observed in the other periods. Group E showed an increase of 39.46% in the total layer, reflected by increases in the thickness of the hypertrophic (42.24%, hyaline (46.92% and proliferative (17.70% layers. CONCLUSIONS: Posteriorly repositioning the mandible produced a series of histological and morphological responses in the condyle, suggesting condylar and mandibular adaptation in rats.

Morphometric evaluation of condylar cartilage of growing rats in response to mandibular retractive forces.

Science.gov (United States)

de Sá, Milena Peixoto Nogueira; Zanoni, Jacqueline Nelisis; de Salles, Carlos Luiz Fernandes; de Souza, Fabrício Dias; Suga, Uhana Seifert Guimarães; Terada, Raquel Sano Suga

2013-01-01

The mandibular condylar surface is made up of four layers, i.e., an external layer composed of dense connective tissue, followed by a layer of undifferentiated cells, hyaline cartilage and bone. Few studies have demonstrated the behavior of the condylar cartilage when the mandible is positioned posteriorly, as in treatments for correcting functional Class III malocclusion. The aim of this study was to assess the morphologic and histological aspects of rat condyles in response to posterior positioning of the mandible. Thirty five-week-old male Wistar rats were selected and randomly divided into two groups: A control group (C) and an experimental group (E) which received devices for inducing mandibular retrusion. The animals were euthanized at time intervals of 7, 21 and 30 days after the experiment had began. For histological analysis, total condylar thickness was measured, including the proliferative, hyaline and hypertrophic layers, as well as each layer separately, totaling 30 measurements for each parameter of each animal. The greatest difference in cartilage thickness was observed in 21 days, although different levels were observed in the other periods. Group E showed an increase of 39.46% in the total layer, reflected by increases in the thickness of the hypertrophic (42.24%), hyaline (46.92%) and proliferative (17.70%) layers. Posteriorly repositioning the mandible produced a series of histological and morphological responses in the condyle, suggesting condylar and mandibular adaptation in rats.

[Study on the method of two dimensional polycrylamide gel electrophoresis on rat condylar chondrocyte].

Science.gov (United States)

Wu, Tuo-jiang; Li, Huang; Ma, Qiao-lin; Wang, Wen-mei

2010-08-01

To investigate the protein profile by two dimensional polycrylamide gel electrophoresis on the rat condylar chondrocyte in vitro. The third-passage chondrocytes were harvested from the mandibular condyles of 2-day-old rats in this study. The protein profile of the rat mandibular condylar chondrocytes was examined by two dimensional polycrylamide gel electrophoresis (2-DE-PAGE). The 2-DE gel maps on different pH gradients were obtained. The result of modified coomassi blue-sliver staining and sliver staining was compared using Pdquest 7.1 image analysis software. The results showed that the good protein profile of the condylar chondrocytes was obtained by standard Bio-Rad manual. The protein was mainly in the field from pH4 to pH7. The 1203±86 protein points were examined on 2-DE gel map by modified coomassi blue-sliver staining, and 1769±97 protein points was examined by sliver staining. The silver staining map showed more distinctly but higher background than modified coomassi blue-sliver staining. The protein profile of the condylar chondrocytes enriches the proteomic database and gives evidence to further proteomic research. The 2-DE map obtained by modified coomassi blue-sliver staining is more suitable for MALDI-TOF mass identification. Supported by National Natural Science Foundation of China (Grant No. C30700963), China Postdoctoral Science Foundation(Grant No.20090461088), Jiangsu Provincial Postdoctoral Science Foundation (Grant No.0802003C) and Nanjing City's Science and Technology Foundation (Grant No.200905011).

Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System

Directory of Open Access Journals (Sweden)

Bo Kyun Sim

2017-01-01

Full Text Available The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA.

Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System

Science.gov (United States)

Kim, Bongju; Shin, Yoo Jin

2017-01-01

The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA) and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA. PMID:29065610

Technical Support for the development of DCS

Energy Technology Data Exchange (ETDEWEB)

Oh, In Seok; Lee, Cheol Kwon; Kim, Dong Hoon; Kim, Jung Taek; Hwang, In Koo; Park, Jae Chang; Lee, Dong Young; Park, Won Man

2008-05-15

The objective of this project is to provide a technical support to Woori Tech Co. in its design and manufacture process of the DCS as a part of KNICS development program to promote the technology self-reliance for non-safety equipment for NPPs(Nuclear Power Plants). We support Woori Tech Co. to develop a DCS which satisfies the requirements for Shinkori 3 and 4 NPPs in the aspects of reliability, applicability and technical competitiveness. As the results of this project the following items were developed and/or implemented; {center_dot} Design basis and requirements for a DCS system {center_dot} Design requirements for control communication networks {center_dot} Architecture of control networks {center_dot} Design requirements of EWS(Engineering Workstation) {center_dot} Plan of software verification and validation {center_dot} Operation display design {center_dot} Soft control functions {center_dot} Application development tools of DCS {center_dot} Analysis and V/V activities on DCS control network protocols {center_dot} Software verification and validation and documentation guidelines {center_dot} User manual documents.

Condylar growth after non-surgical advancement in adult subject: a case report

Directory of Open Access Journals (Sweden)

Caradonna Carola

2009-07-01

Full Text Available Abstract Background A defect of condylar morphology can be caused by several sources. Case report A case of altered condylar morphology in adult male with temporomandibular disorders was reported in 30-year-old male patient. Erosion and flattening of the left mandibular condyle were observed by panoramic x-ray. The patient was treated with splint therapy that determined mandibular advancement. Eight months after the therapy, reduction in joint pain and a greater opening of the mouth was observed, although crepitation sounds during mastication were still noticeable. Conclusion During the following months of gnatologic treatment, new bone growth in the left condyle was observed by radiograph, with further improvement of the symptoms.

Roles of Ihh signaling in chondroprogenitor function in postnatal condylar cartilage.

Science.gov (United States)

Kurio, Naito; Saunders, Cheri; Bechtold, Till E; Salhab, Imad; Nah, Hyun-Duck; Sinha, Sayantani; Billings, Paul C; Pacifici, Maurizio; Koyama, Eiki

2018-04-01

Condylar articular cartilage in mouse temporomandibular joint develops from progenitor cells near the articulating surface that proliferate, undergo chondrogenesis and mature into hypertrophic chondrocytes. However, it remains unclear how these processes are regulated, particularly postnatally. Here we focused on the apical polymorphic layer rich in progenitors and asked whether the phenotype and fate of the cells require signaling by Indian hedgehog (Ihh) previously studied in developing long bones. In condyles in newborn mice, the apical polymorphic/progenitor cell layer was ~10 cell layer-thick and expressed the articular matrix marker Tenascin-C (Tn-C), and the underlying thick cell layer expressed Tn-C as well as the chondrogenic master regulator Sox9. By 1 month, condylar cartilage had gained its full width, but became thinner along its main longitudinal axis and displayed hypertrophic chondrocytes. By 3 months, articular cartilage consisted of a 2-3 cell layer-thick zone of superficial cells and chondroprogenitors expressing both Tn-C and Sox9 and a bottom zone of chondrocytes displaying vertical matrix septa. EdU cell tracing in juvenile mice revealed that conversion of chondroprogenitors into chondrocytes and hypertrophic chondrocytes required about 48 and 72 h, respectively. Notably, EdU injection in 3 month-old mice labeled both progenitors and maturing chondrocytes by 96 h. Conditional ablation of Ihh in juvenile/early adult mice compromised chondroprogenitor organization and function and led to reduced chondroprogenitor and chondrocyte proliferation. The phenotype of mutant condyles worsened over time as indicated by apoptotic chondrocyte incidence, ectopic chondrocyte hypertrophy, chondrocyte column derangement and subchondral bone deterioration. In micromass cultures of condylar apical cells, hedgehog (Hh) treatment stimulated chondrogenesis and alkaline phosphatase (APase) activity, while treatment with HhAntag inhibited both. Our findings

Effects of High-Definition and Conventional tDCS on Response Inhibition.

Science.gov (United States)

Hogeveen, J; Grafman, J; Aboseria, M; David, A; Bikson, M; Hauner, K K

2016-01-01

Response inhibition is a critical executive function, enabling the adaptive control of behavior in a changing environment. The inferior frontal cortex (IFC) is considered to be critical for response inhibition, leading researchers to develop transcranial direct current stimulation (tDCS) montages attempting to target the IFC and improve inhibitory performance. However, conventional tDCS montages produce diffuse current through the brain, making it difficult to establish causality between stimulation of any one given brain region and resulting behavioral changes. Recently, high-definition tDCS (HD-tDCS) methods have been developed to target brain regions with increased focality relative to conventional tDCS. Remarkably few studies have utilized HD-tDCS to improve cognitive task performance, however, and no study has directly compared the behavioral effects of HD-tDCS to conventional tDCS. In the present study, participants received either HD-tDCS or conventional tDCS to the IFC during performance of a response inhibition task (stop-signal task, SST) or a control task (choice reaction time task, CRT). A third group of participants completed the same behavioral protocols, but received tDCS to a control site (mid-occipital cortex). Post-stimulation improvement in SST performance was analyzed as a function of tDCS group and the task performed during stimulation using both conventional and Bayesian parameter estimation analyses. Bayesian estimation of the effects of HD- and conventional tDCS to IFC relative to control site stimulation demonstrated enhanced response inhibition for both conditions. No improvements were found after control task (CRT) training in any tDCS condition. Results support the use of both HD- and conventional tDCS to the IFC for improving response inhibition, providing empirical evidence that HD-tDCS can be used to facilitate performance on an executive function task. Copyright © 2016 Elsevier Inc. All rights reserved.

Masticatory motion after surgical or nonsurgical treatment for unilateral fractures of the mandibular condylar process.

Science.gov (United States)

Throckmorton, Gaylord S; Ellis, Edward; Hayasaki, Haruaki

2004-02-01

We sought to compare mandibular motion during mastication in patients treated in either an open or a closed fashion for unilateral fractures of the mandibular condylar process. Eighty-one male patients with unilateral condylar process fractures were treated either with (n = 37) or without (n = 44) surgical reduction and rigid fixation of their condylar process fractures. At 6 weeks, 6 months, 1 year, and 2 years after treatment, the subjects' chewing cycles were recorded using a magnetic sensor array (Sirognathograph; Siemens Corp, Bensheim, Germany) while chewing Gummi-Bears (HARIBO, Bonn, Germany) unilaterally on the same side as the fracture and on the opposite side. The chewing cycles were analyzed using a custom computer program, and the duration, excursive ranges, and 3-dimensional cycle shape were compared between the 2 treatment groups at each time interval using multilevel linear modeling statistics. The 2 treatment groups did not differ significantly for any measure of cycle duration or any excursive range (except lateral excursions at 1 year post-treatment) at any of the time intervals. However, the 3-dimensional cycle shapes of the 2 groups did differ significantly at all time intervals. Surgical correction of unilateral condylar process fractures has relatively little effect on the more standard measures (duration and excursive ranges) of masticatory function. However, surgical correction better normalizes opening incisor pathways during mastication on the side opposite the fracture.

Condylar guidance: correlation between protrusive interocclusal record and panoramic radiographic image: a pilot study.

Science.gov (United States)

Tannamala, Pavan Kumar; Pulagam, Mahesh; Pottem, Srinivas R; Swapna, B

2012-04-01

The purpose of this study was to compare the sagittal condylar angles set in the Hanau articulator by use of a method of obtaining an intraoral protrusive record to those angles found using a panoramic radiographic image. Ten patients, free of signs and symptoms of temporomandibular disorder and with intact dentition were selected. The dental stone casts of the subjects were mounted on a Hanau articulator with a springbow and poly(vinyl siloxane) interocclusal records. For all patients, the protrusive records were obtained when the mandible moved forward by approximately 6 mm. All procedures for recording, mounting, and setting were done in the same session. The condylar guidance angles obtained were tabulated. A panoramic radiographic image of each patient was made with the Frankfurt horizontal plane parallel to the floor of the mouth. Tracings of the radiographic images were made. The horizontal reference line was marked by joining the orbitale and porion. The most superior and most inferior points of the curvatures were identified. These two lines were connected by a straight line representing the mean curvature line. Angles made by the intersection of the mean curvature line and the horizontal reference line were measured. The results were subjected to statistical analysis with a significance level of p record method. The mean condylar guidance angle between the right and left side by both the methods was not statistically significant. The comparison of mean condylar guidance angles between the right side of the protrusive record method and the right side of the panoramic radiographic method and the left side of the protrusive record method and the left side of the panoramic radiographic method (p= 0.071 and p= 0.057, respectively) were not statistically significant. Within the limitations of this study, it was concluded that the protrusive condylar guidance angles obtained by panoramic radiograph may be used in programming semi-adjustable articulators. © 2012

Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System

OpenAIRE

Sim, Bo Kyun; Kim, Bongju; Kim, Min Jeong; Jeong, Guk Hyun; Ju, Kyung Won; Shin, Yoo Jin; Kim, Man Yong; Lee, Jong-Ho

2017-01-01

The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access ...

Extraction of sunflower oil by twin screw extruder: screw configuration and operating condition effects

Energy Technology Data Exchange (ETDEWEB)

Kartika, I.A. [FATETA-IPB, Bogor (Indonesia). Department of Agroindustrial Technology; Pontalier, P.Y.; Rigal, L. [Laboratoire de Chimie Agro-Industrielle, UMR 1010 INRA/INP-ENSIACET, Toulouse (France)

2006-12-15

The objective of this study was to investigate the screw configuration allowing oil extraction from sunflower seeds with a twin-screw extruder. Experiments were conducted using a co-rotating twin-screw extruder. Five screw profiles were examined to define the best performance (oil extraction yield, specific mechanical energy and oil quality) by studying the influence of operating conditions, barrel temperature, screw speed and feed rate. Generally, the position and spacing between two reversed screw elements affected oil extraction yield. An increase of oil extraction yield was observed as the reversed screw elements were moved with increased spacing between two elements and with smaller pitch elements. In addition, oil extraction yield increased as barrel temperature, screw speed and feed rate were decreased. Highest oil extraction yield (85%) with best cake meal quality (residual oil content lower than 13%) was obtained under operating conditions of 120 {sup o}C, 75 rpm and 19 kg/h. Furthermore, the operating parameters influenced energy input. A decrease in barrel temperature and feed rate followed by an increase in screw speed increased energy input, particularly specific mechanical energy input. Effect of the operating parameters on oil quality was less important. In all experiments tested, the oil quality was very good. The acid value was below 2 mg of KOH/g of oil and total phosphorus content was low, below 100 mg/kg. (author)

TileDCS web system

International Nuclear Information System (INIS)

Maidantchik, C; Ferreira, F; Grael, F

2010-01-01

The web system described here provides features to monitor the ATLAS Detector Control System (DCS) acquired data. The DCS is responsible for overseeing the coherent and safe operation of the ATLAS experiment hardware. In the context of the Hadronic Tile Calorimeter Detector (TileCal), it controls the power supplies of the readout electronics acquiring voltages, currents, temperatures and coolant pressure measurements. The physics data taking requires the stable operation of the power sources. The TileDCS Web System retrieves automatically data and extracts the statistics for given periods of time. The mean and standard deviation outcomes are stored as XML files and are compared to preset thresholds. Further, a graphical representation of the TileCal cylinders indicates the state of the supply system of each detector drawer. Colors are designated for each kind of state. In this way problems are easier to find and the collaboration members can focus on them. The user selects a module and the system presents detailed information. It is possible to verify the statistics and generate charts of the parameters over the time. The TileDCS Web System also presents information about the power supplies latest status. One wedge is colored green whenever the system is on. Otherwise it is colored red. Furthermore, it is possible to perform customized analysis. It provides search interfaces where the user can set the module, parameters, and the time period of interest. The system also produces the output of the retrieved data as charts, XML files, CSV and ROOT files according to the user's choice.

The pullout performance of pedicle screws

CERN Document Server

Demir, Teyfik

2015-01-01

This brief book systematically discusses all subjects that affect the pullout strength of pedicle screws. These screws are used in spinal surgeries to stabilize the spine. The holding strength of the pedicle screw is vital since loosening of the pedicle screws can cause revision surgeries. Once the pedicle screw is pulled out, it is harder to obtain same stabilization for the fused vertebrae. The book reviews the effect of screw designs, application techniques, cement augmentation, coating of the screw and test conditions on the pullout strength. The studies with finite element analysis were also included.

Simultaneous transcranial direct current stimulation (tDCS) and whole-head magnetoencephalography (MEG): assessing the impact of tDCS on slow cortical magnetic fields.

Science.gov (United States)

Garcia-Cossio, Eliana; Witkowski, Matthias; Robinson, Stephen E; Cohen, Leonardo G; Birbaumer, Niels; Soekadar, Surjo R

2016-10-15

Transcranial direct current stimulation (tDCS) can influence cognitive, affective or motor brain functions. Whereas previous imaging studies demonstrated widespread tDCS effects on brain metabolism, direct impact of tDCS on electric or magnetic source activity in task-related brain areas could not be confirmed due to the difficulty to record such activity simultaneously during tDCS. The aim of this proof-of-principal study was to demonstrate the feasibility of whole-head source localization and reconstruction of neuromagnetic brain activity during tDCS and to confirm the direct effect of tDCS on ongoing neuromagnetic activity in task-related brain areas. Here we show for the first time that tDCS has an immediate impact on slow cortical magnetic fields (SCF, 0-4Hz) of task-related areas that are identical with brain regions previously described in metabolic neuroimaging studies. 14 healthy volunteers performed a choice reaction time (RT) task while whole-head magnetoencephalography (MEG) was recorded. Task-related source-activity of SCFs was calculated using synthetic aperture magnetometry (SAM) in absence of stimulation and while anodal, cathodal or sham tDCS was delivered over the right primary motor cortex (M1). Source reconstruction revealed task-related SCF modulations in brain regions that precisely matched prior metabolic neuroimaging studies. Anodal and cathodal tDCS had a polarity-dependent impact on RT and SCF in primary sensorimotor and medial centro-parietal cortices. Combining tDCS and whole-head MEG is a powerful approach to investigate the direct effects of transcranial electric currents on ongoing neuromagnetic source activity, brain function and behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

Internal fixation of severely displaced mandibular condylar neck fracture with the aid of ramus osteotomy. A revised technique

DEFF Research Database (Denmark)

Hillerup, S

1997-01-01

A technique is described whereby the mandibular condyle can be located, replaced and fixed in case of a severely displaced fracture with exarticulation of the condylar head.......A technique is described whereby the mandibular condyle can be located, replaced and fixed in case of a severely displaced fracture with exarticulation of the condylar head....

Development of load calculation techniques on screw and screw press energy consumption

OpenAIRE

Татарьянц, Максим Сергеевич; Завинский, Сергей Иванович; Трошин, Алексей Георгиевич

2015-01-01

The process of pressing of wood chips in screw machines is researched. It is defined processes taking place in different parts of the screw, formulas allowing to calculate the loads acting on the screw flights, as well as to determine the power required for compression. The unit costs of energy consumption and raw materials in the degree of heat pressing are determined

Evaluation of Hanau's formula in determination of lateral condylar guidance: A clinical research study

Science.gov (United States)

Bhawsar, Sanjay Vasant; Marathe, Ashlesha Subhash; Ansari, Sadekh Abdul

2015-01-01

Statement of Problem: The accuracy and reliability of the methods used for programming the semi-adjustable articulators determine the accuracy in occlusion. The current recommended average settings using the Hanau's formula commonly used by clinicians is questionable, and thus reassessment is needed. This study was carried out to evaluate and compare the lateral condylar guidance: (1) Using the Hanau's formula and the computerized jaw tracking device (Kinesiograph). (2) On the right and left sides using both these methods. Materials and Methods: A total of 20 completely edentulous patients (14 male and 6 females) within 40–60 years of age were selected. Jaw relation was recorded followed by face bow transfer. Extraoral Gothic arch tracing was recorded; three protrusive records were obtained and condylar guidance was calculated. Lateral condylar guidance was then calculated using Hanau's formula, followed by the computerized jaw tracking device. A comparative evaluation was done of the obtained values. The same investigator worked with each of the study participants for the purpose of standardization. Results: The lateral condylar guidance values obtained using the Hanau's formula ranged from 14 to 17° while those obtained using the computerized K7 jaw tracking device ranged from 8 to 40°. Bennett angle values, obtained using the jaw tracking device and Hanau's formula showed statistically significant differences (P 0.05). Conclusion: Based on the results, dentist and dental technicians should consider reassessing the current recommended average settings and use of the Hanau's formula for programming the semi-adjustable articulators. PMID:26929535

Association between condylar morphology and inflammation in experimental temporomandibular joint TMJ arthritis

DEFF Research Database (Denmark)

Kristensen, Kasper Dahl; Stoustrup, Peter bangsgaard; Küseler, Annelise

not previously been investigated. Aim: We studied the effects of antigen-induced arthritis on the bony structures in rabbit mandibular condylar development, in particular the morphological changes and the bone micro-architecture. Materials and Methods: Included were juvenile rabbits with ovalbumin-induced TMJ...... arthritis treated with intraarticular saline, intra-articular etanercept (an anti-TNF-α drug) or subcutaneous etanercept. One TMJ from each animal was scanned using micro-computed tomography and structural parameters were calculated. Three-dimensional reconstructions of the mandibular condyle were scored...... blindly by two independent observers as normal or abnormal. TMJs were stratified for condylar morphology and evaluated against data on inflammation, trabecular structural parameters, and overall mandibular growth. Mineral apposition rate was measured using fluorochrome labelling. Results and discussion...

Mandibular condylar fractures and acute atlanto-axial subluxation Part 2 A physiopathological factor for the cervical spine sprain.

Science.gov (United States)

Cutilli, T; Corbacelli, A

2009-05-01

The aim of this study was to analyze the physiopathology of the acute cervical injure in the event of mandibular condylar fractures. As in the Part 1, 25 non-consecutive cases of condylar mandibular fractures (16 males and 9 females, mean age: 22.96/range 14-36 years) observed and treated in the Maxillofacial Surgery Department of the University of L'Aquila, have been studied. Types of fractures examined included: unilateral: 19 cases (solitary: 12; associated with other mandibular fractures: 7, homolateral: 2); bilateral: 6 cases (equivalent: 2, not equivalent: 4). A control group was constituted of 10 patients, 5 males and 5 females, aged from 19 to 24 years (mean range: 21.6) suffering from acute isolated cervical distorsion (whiplash). The study has been performed by means of the analysis of X-ray and computed tomography (CT)-CT/3D of the mandibular condylar regions, the occipital-atlanto-axial structures and the cervical region. In all the patients the following constant alterations that link up with these fractures have been observed: the rotation of atlas, the atlanto-axial subluxation and the derangement of the occipital-atlanto-epistropheal joint, homolateral to the side of the mandibular condylar fracture. The cervical spine shows the constant loss of physiological lordosis with hinge between C3 and C4. In the whiplash, as the authors have been able to assess in the control group, there are no alterations of occipital-atlanto-axial joint and the kinetic vector is placed on the longitudinal plane. In the mandibular condylar fractures the kinetic mechanism is completely different regarding the whiplash. The point of entry is the chin and the kinetic vector is oriented down-up, sometimes oblique in the opposite side. Subsequently the kinetic force is transmitted throughout the mandibular structure and causes the condylar or bicondylar fracture. The kinetic vector is placed before on the vertical plane, then on the horizontal plane and later on the vertical

2D and 3D assessment of sustentaculum tali screw fixation with or without Screw Targeting Clamp.

Science.gov (United States)

De Boer, A Siebe; Van Lieshout, Esther M M; Vellekoop, Leonie; Knops, Simon P; Kleinrensink, Gert-Jan; Verhofstad, Michael H J

2017-12-01

Precise placement of sustentaculum tali screw(s) is essential for restoring anatomy and biomechanical stability of the calcaneus. This can be challenging due to the small target area and presence of neurovascular structures on the medial side. The aim was to evaluate the precision of positioning of the subchondral posterior facet screw and processus anterior calcanei screw with or without a Screw Targeting Clamp. The secondary aim was to evaluate the added value of peroperative 3D imaging over 2D radiographs alone. Twenty Anubifix™ embalmed, human anatomic lower limb specimens were used. A subchondral posterior facet screw and a processus anterior calcanei screw were placed using an extended lateral approach. A senior orthopedic trauma surgeon experienced in calcaneal fracture surgery and a senior resident with limited experience in calcaneal surgery performed screw fixation in five specimens with and in five specimens without the clamp. 2D lateral and axial radiographs and a 3D recording were obtained postoperatively. Anatomical dissection was performed postoperatively as a diagnostic golden standard in order to obtain the factual screw positions. Blinded assessment of quality of fixation was performed by two surgeons. In 2D, eight screws were considered malpositioned when placed with the targeting device versus nine placed freehand. In 3D recordings, two additional screws were malpositioned in each group as compared to the golden standard. As opposed to the senior surgeon, the senior resident seemed to get the best results using the Screw Targeting Clamp (number of malpositioned screws using freehand was eight, and using the targeting clamp five). In nine out of 20 specimens 3D images provided additional information concerning target area and intra-articular placement. Based on the 3D assessment, five additional screws would have required repositioning. Except for one, all screw positions were rated equally after dissection when compared with 3D examinations

Transcranial direct current stimulation (tDCS) modulation of picture naming and word reading: A meta-analysis of single session tDCS applied to healthy participants.

Science.gov (United States)

Westwood, Samuel J; Romani, Cristina

2017-09-01

Recent reviews quantifying the effects of single sessions of transcranial direct current stimulation (or tDCS) in healthy volunteers find only minor effects on cognition despite the popularity of this technique. Here, we wanted to quantify the effects of tDCS on language production tasks that measure word reading and picture naming. We reviewed 14 papers measuring tDCS effects across a total of 96 conditions to a) quantify effects of conventional stimulation on language regions (i.e., left hemisphere anodal tDCS administered to temporal/frontal areas) under normal conditions or under conditions of cognitive (semantic) interference; b) identify parameters which may moderate the size of the tDCS effect within conventional stimulation protocols (e.g., online vs offline, high vs. low current densities, and short vs. long durations), as well as within types of stimulation not typically explored by previous reviews (i.e., right hemisphere anodal tDCS or left/right hemisphere cathodal tDCS). In all analyses there was no significant effect of tDCS, but we did find a small but significant effect of time and duration of stimulation with stronger effects for offline stimulation and for shorter durations (tDCS and its poor efficacy in healthy participants. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Frictional performance of ball screw

International Nuclear Information System (INIS)

Nakashima, Katuhiro; Takafuji, Kazuki

1985-01-01

As feed screws, ball screws have become to be adopted in place of trapezoidal threads. The structure of ball screws is complex, but those are the indispensable component of NC machine tools and machining centers, and are frequently used for industrial robots. As the problems in the operation of ball screws, there are damage, life and the performance related to friction. As to the damage and life, though there is the problem of the load distribution on balls, the results of the research on rolling bearings are applied. The friction of ball screws consists of the friction of balls and a spiral groove, the friction of a ball and a ball, the friction in a ball-circulating mechanism and the viscous friction of lubricating oil. It was decided to synthetically examine the frictional performance of ball screws, such as driving torque, the variation of driving torque, efficiency, the formation of oil film and so on, under the working condition of wide range, using the screws with different accuracy and the nuts of various circuit number. The experimental setup and the processing of the experimental data, the driving performance of ball screws and so on are reported. (Kako, I.)

Fetal jaw movement affects Ihh signaling in mandibular condylar cartilage development: the possible role of Ihh as mechanotransduction mediator.

Science.gov (United States)

Jahan, Esrat; Matsumoto, Akihiro; Rafiq, Ashiq Mahmood; Hashimoto, Ryuju; Inoue, Takayuki; Udagawa, Jun; Sekine, Joji; Otani, Hiroki

2014-10-01

Jaw movement is an important mechanical factor for prenatal development of the condylar cartilage of mandible. Fetal jaw movement restriction has been shown to cause deformity of the mandibular condyle. We hypothesized that this treatment affects the expression of mechanosensitive molecules, namely Indian hedgehog (Ihh) and Parathyroid hormone related protein (PTHrP) in the condyle. We restrained jaw movement by suturing the jaw of E15.5 mouse embryos and allowed them to develop until E18.5 using exo utero system, and analyzed them by immunohistochemistry and in situ hybridization methods. Morphological, histomorphometric and immunohistochemical study showed that the mandibular condylar cartilage was reduced and deformed, the volume and total cell numbers in the condylar cartilage were also reduced, and number and/or distribution of 5-bromo-2'-deoxyuridine-positive cells, Ihh-positive cells in the mesenchymal and pre-hypertrophic zones were significantly and correspondingly decreased in the sutured group. Using in situ hybridization, reduced expression of Ihh, PTHrP and their related receptors were observed in condylar cartilage of the sutured embryos. Our results revealed that the altered mechanical stress induced by prenatal jaw movement restriction decreased proliferating cells, the amount of cartilage, and altered expression of the Ihh and PTHrP, suggesting that Ihh act as mechanotransduction mediators in the development of mandibular condylar cartilage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Kinematics of Planetary Roller Screw Mechanism considering Helical Directions of Screw and Roller Threads

Directory of Open Access Journals (Sweden)

Shangjun Ma

2015-01-01

Full Text Available Based on the differential principle of thread transmission, an analytical model considering helical directions between screw and roller threads in planetary roller screw mechanism (PRSM is presented in this work. The model is critical for the design of PRSM with a smaller lead and a bigger pitch to realize a higher transmission accuracy. The kinematic principle of planetary transmission is employed to analyze the PRSM with different screw thread and roller thread directions. In order to investigate the differences with different screw thread and roller thread directions, the numerical model is developed by using the software Adams to validate the analytical solutions calculated by the presented model. The results indicate, when the helical direction of screw thread is identical with the direction of roller thread, that the lead of PRSM is unaffected regardless of whether sliding between screw and rollers occurs or not. Only when the direction of screw thread is reverse to the direction of roller thread, the design of PRSM with a smaller lead can be realized under a bigger pitch. The presented models and numerical simulation method can be used to research the transmission accuracy of PRSM.

Resorbable triangular plate for osteosynthesis of fractures of the condylar neck.

Science.gov (United States)

Lauer, Günter; Pradel, Winnie; Leonhardt, Henry; Loukota, Richard; Eckelt, Uwe

2010-10-01

We describe a new design of resorbable plate for use in the treatment of fractures of the condylar neck, and report the outcome of initial treatment in two patients. Copyright © 2009 The British Association of Oral and Maxillofacial Surgeons. All rights reserved.

Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

Directory of Open Access Journals (Sweden)

Kang-Young Choi

2012-07-01

Full Text Available The incidence of condylar fractures is high, but the management of fractures of the mandibular condyle continues to be controversial. Historically, maxillomandibular fixation, external fixation, and surgical splints with internal fixation systems were the techniques commonly used in the treatment of the fractured mandible. Condylar fractures can be extracapsular or intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on the age of the patient, the co-existence of other mandibular or maxillary fractures, whether the condylar fracture is unilateral or bilateral, the level and displacement of the fracture, the state of dentition and dental occlusion, and the surgeonnds on the age of the patient, the co-existence of othefrom which it is difficult to recover aesthetically and functionally;an appropriate treatment is required to reconstruct the shape and achieve the function ofthe uninjured status. To do this, accurate diagnosis, appropriate reduction and rigid fixation, and complication prevention are required. In particular, as mandibular condyle fracture may cause long-term complications such as malocclusion, particularly open bite, reduced posterior facial height, and facial asymmetry in addition to chronic pain and mobility limitation, great caution should be taken. Accordingly, the authors review a general overview of condyle fracture.

Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

Science.gov (United States)

Yang, Jung-Dug; Chung, Ho-Yun; Cho, Byung-Chae

2012-01-01

The incidence of condylar fractures is high, but the management of fractures of the mandibular condyle continues to be controversial. Historically, maxillomandibular fixation, external fixation, and surgical splints with internal fixation systems were the techniques commonly used in the treatment of the fractured mandible. Condylar fractures can be extracapsular or intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on the age of the patient, the co-existence of other mandibular or maxillary fractures, whether the condylar fracture is unilateral or bilateral, the level and displacement of the fracture, the state of dentition and dental occlusion, and the surgeonnds on the age of the patient, the co-existence of othefrom which it is difficult to recover aesthetically and functionally;an appropriate treatment is required to reconstruct the shape and achieve the function ofthe uninjured status. To do this, accurate diagnosis, appropriate reduction and rigid fixation, and complication prevention are required. In particular, as mandibular condyle fracture may cause long-term complications such as malocclusion, particularly open bite, reduced posterior facial height, and facial asymmetry in addition to chronic pain and mobility limitation, great caution should be taken. Accordingly, the authors review a general overview of condyle fracture. PMID:22872830

Loosening torque of Universal Abutment screws after cyclic loading: influence of tightening technique and screw coating.

Science.gov (United States)

Bacchi, Atais; Regalin, Alexandre; Bhering, Claudia Lopes Brilhante; Alessandretti, Rodrigo; Spazzin, Aloisio Oro

2015-10-01

The purpose of this study was to evaluate the influence of tightening technique and the screw coating on the loosening torque of screws used for Universal Abutment fixation after cyclic loading. Forty implants (Titamax Ti Cortical, HE, Neodent) (n=10) were submerged in acrylic resin and four tightening techniques for Universal Abutment fixation were evaluated: A - torque with 32 Ncm (control); B - torque with 32 Ncm holding the torque meter for 20 seconds; C - torque with 32 Ncm and retorque after 10 minutes; D - torque (32 Ncm) holding the torque meter for 20 seconds and retorque after 10 minutes as initially. Samples were divided into subgroups according to the screw used: conventional titanium screw or diamond like carbon-coated (DLC) screw. Metallic crowns were fabricated for each abutment. Samples were submitted to cyclic loading at 10(6) cycles and 130 N of force. Data were analyzed by two-way ANOVA and Tukey's test (5%). The tightening technique did not show significant influence on the loosening torque of screws (P=.509). Conventional titanium screws showed significant higher loosening torque values than DLC (P=.000). The use of conventional titanium screw is more important than the tightening techniques employed in this study to provide long-term stability to Universal Abutment screws.

Sacroiliac Screw Fixation

NARCIS (Netherlands)

E.W. van den Bosch

2003-01-01

textabstractThe aim of this thesis is to evaluate three major aspects of the use of sacroiliac screws in patients with unstable pelvic ring fractures: the optimal technique for sacroiliac screw fixation, the reliability of peroperative fluoroscopy and the late results. We focused on the questions

Effects of growth factors and glucosamine on porcine mandibular condylar cartilage cells and hyaline cartilage cells for tissue engineering applications.

Science.gov (United States)

Wang, Limin; Detamore, Michael S

2009-01-01

Temporomandibular joint (TMJ) condylar cartilage is a distinct cartilage that has both fibrocartilaginous and hyaline-like character, with a thin proliferative zone that separates the fibrocartilaginous fibrous zone at the surface from the hyaline-like mature and hypertrophic zones below. In this study, we compared the effects of insulin-like growth factor-I (IGF-I), basic fibroblast growth factor (bFGF), transforming growth factor beta1 (TGF-beta1), and glucosamine sulphate on porcine TMJ condylar cartilage and ankle cartilage cells in monolayer culture. In general, TMJ condylar cartilage cells proliferated faster than ankle cartilage cells, while ankle cells produced significantly greater amounts of glycosaminoglycans (GAGs) and collagen than TMJ condylar cartilage cells. IGF-I and bFGF were potent stimulators of TMJ cell proliferation, while no signals statistically outperformed controls for ankle cell proliferation. IGF-I was the most effective signal for GAG production with ankle cells, and the most potent upregulator of collagen synthesis for both cell types. Glucosamine sulphate promoted cell proliferation and biosynthesis at specific concentrations and outperformed growth factors in certain instances. In conclusion, hyaline cartilage cells had lower cell numbers and superior biosynthesis compared to TMJ condylar cartilage cells, and we have found IGF-I at 100 ng/mL and glucosamine sulphate at 100 microg/mL to be the most effective signals for these cells under the prescribed conditions.

DCS Budget Tracking System

Data.gov (United States)

Social Security Administration — DCS Budget Tracking System database contains budget information for the Information Technology budget and the 'Other Objects' budget. This data allows for monitoring...

IMF-screws or arch bars as conservative treatment for mandibular condyle fractures: Quality of life aspects.

Science.gov (United States)

van den Bergh, B; de Mol van Otterloo, J J; van der Ploeg, T; Tuinzing, D B; Forouzanfar, T

2015-09-01

Arch bars as treatment for a fractured mandibular condyle are inconvenient to patients and lead to lowered quality of life (QOL). To overcome these inconveniences, IMF-screws (IMFS) to facilitate intermaxillary fixation during surgery have been developed. The purpose of the present study is to investigate and compare QOL for patients treated for a fractured mandibular condyle with either IMFS or arch bars. This research trial was conducted from 2010 to 2014 as part of an earlier prospective, multicenter, randomized clinical trial in which the use of IMFS was compared to the use of arch bars in the treatment of mandibular condylar fractures. In total, 50 patients were included: 30 (60%) male patients and 20 (40%) female patients (mean age: 31.8 years, standard deviation [SD] = 13.9 years, range = 18-64 years). A total of 24 (48%) patients were allocated in the IMFS group, and 26 (52%) patients were assigned to the arch-bars control group. Significant results were observed in the subscales social isolation, possibility to eat and vary diet, influence on sleep, and satisfaction with the given treatment, all in favour of IMFS. In conclusion, using IMFS as a method for conservative treatment of condylar fractures led to a higher QOL during the 6-week period of fracture healing. In comparison to arch bars, patients treated with IMFS experienced less social isolation, had fewer problems with eating, and express the feeling they are able to continue their normal diet. Furthermore it seems that the use of IMFS has a lower negative impact on social and financial aspects of the patient. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Complications of syndesmotic screw removal

NARCIS (Netherlands)

Schepers, Tim; van Lieshout, Esther M. M.; de Vries, Mark R.; van der Elst, Maarten

2011-01-01

Currently, the metallic syndesmotic screw is the gold standard in the treatment of syndesmotic disruption. Whether or not this screw needs to be removed remains debatable. The aim of the current study was to determine the complications which occur following routine removal of the syndesmotic screw

Hits and Misses: Leveraging tDCS to Advance Cognitive Research

Directory of Open Access Journals (Sweden)

Marian E Berryhill

2014-07-01

Full Text Available The popularity of non-invasive brain stimulation techniques in basic, commercial, and applied settings grew tremendously over the last decade. Here, we focus on one popular neurostimulation method: transcranial direct current stimulation (tDCS. Many assumptions regarding the outcomes of tDCS are based on the results of stimulating motor cortex. For instance, the primary motor cortex is predictably suppressed by cathodal tDCS or made more excitable by anodal tDCS. However, wide-ranging studies testing cognition provide more complex and sometimes paradoxical results that challenge this heuristic. Here, we first summarize successful efforts in applying tDCS to cognitive questions, with a focus on working memory. These recent findings indicate that tDCS can result in cognitive task improvement or impairment regardless of stimulation site or direction of current flow. We then report working memory and response inhibition studies that failed to replicate and/or extend previously reported effects. From these opposing outcomes, we present a series of factors to consider that are intended to facilitate future use of tDCS when applied to cognitive questions. In short, common pitfalls include testing too few participants, using insufficiently challenging tasks, using heterogeneous participant populations, and including poorly motivated participants. Furthermore, the poorly understood underlying mechanism for long-lasting tDCS effects make it likely that other important factors predict responses. In conclusion, we argue that although tDCS can be used experimentally to understand brain function its greatest potential may be in applied or translational research.

Study on imaging analysis using three-dimensional CT system for mandibular condylar fracture. Establishing quantitative classification

International Nuclear Information System (INIS)

Kurokawa, Hideto

1997-01-01

We examined 13 patients with fractures of the condylar process (7 men, 6 women) by using 3-dimensional images. A break-down of 15 examined joints revealed 11 patients with unilateral and 2 patients with bilateral fractures of the condylar process. Eight joints of healthy control individual (2 men and 2 women) were used as controls. Fractures of the condylar process and healthy controls were compared, which comparison led to the following conclusions: Bone fragments of deviated fractures may move slightly within the joint, preferentially internally and medially; following displaced fractures, internal and downward movement of bone fragments within the joint is observed; after the occurrence of deviated dislocation fractures, bone fragments protrude from the joint and clearly move internally and inferiorly, showing a rotation of the bone fragments; after the occurrence of displaced dislocation fractures, bone fragments also protrude from the joint and clearly move anteriorly and inferiorly; sometimes an internal rotation of the bone fragments is observed; and with linear fractures there is only minimal overall increase in, and characteristic changes are not observed. Regarding diagnosis, the classical classification of fractures of the condylar process does not provide a classification for linear fractures. Thus, this type has to be newly added to the common classification: Fissure fractures (type I), Deviated fractures (type II), Displaced fractures (type III), Deviated dislocation fractures (type IV), Displaced dislocation fractures (type V), Longitudinal (type VI). (author)

Difficulties encountered in preauricular approach over retromandibular approach in condylar fracture

Directory of Open Access Journals (Sweden)

Perumal Jayavelu

2016-01-01

Full Text Available Fracture of mandible can be classified according to its anatomical location, in which condylar fracture is the most common one overall and is missed on clinical examination. Due to the unique geometry of the mandible and temporomandibular joint, without treatment the fractures can result in marked pain, dysfunction, and deformity. The condylar fracture may be further classified depending on the sides involved: unilateral/bilateral, depending on the height of fracture: intracapsular (within the head of condyle, extracapsular - head and neck (high condyle fracture, and subcondylar (low condyle fracture, and depending on displacement: nondisplaced, displaced (anteromedially, medially, and lateral, and dislocated. The clinical features include swelling and tenderness over the temporomandibular joint region, restricted mouth opening, and anterior open bite. A 34-year-old male patient reported to the Department of Oral and Maxillofacial Surgery at Madha Dental College and Hospital; suffered fall trauma resulting in bilateral condyle fracture, dentoalveolar fracture in mandible with restricted mouth opening, and anterior open bite.

Efficient Maturation and Cytokine Production of Neonatal DCs Requires Combined Proinflammatory Signals

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Doreen Krumbiegel

2005-01-01

Full Text Available Specific functional properties of dendritic cells (DCs have been suspected as being responsible for the impaired specific immune responses observed in human neonates. To analyze stimulatory requirements for the critical transition from immature, antigen-processing DCs to mature, antigen-presenting DCs, we investigated the effect of different proinflammatory mediators and antigens on phenotype and cytokine secretion of human neonatal DCs derived from hematopoietic progenitor cells (HPCs. Whereas single proinflammatory mediators were unable to induce the maturation of neonatal DCs, various combinations of IFNγ, CD40L, TNFα, LPS and antigens, induced the maturation of neonatal DCs documented by up-regulation of HLA-DR, CD83 and CD86. Combinations of proinflammatory mediators also increased cytokine secretion by neonatal DCs. Especially combined stimulation with LPS and IFNγ proved to be very efficient in inducing maturation and cytokine synthesis of neonatal DCs. In conclusion, neonatal DCs can be stimulated to express maturation as well as costimulatory surface molecules. However, induction of maturation requires combined stimulation with multiple proinflammatory signals.

Transpedicular screw fixation in the thoracic and lumbar spine with a novel cannulated polyaxial screw system

Directory of Open Access Journals (Sweden)

Lutz Weise

2008-10-01

Full Text Available Lutz Weise, Olaf Suess, Thomas Picht, Theodoros KombosNeurochirurgische Klinik, Charité – Universitätsmedizin Berlin, Berlin, GermanyObjective: Transpedicular screws are commonly and successfully used for posterior fixation in spinal instability, but their insertion remains challenging. Even using navigation techniques, there is a misplacement rate of up to 11%. The aim of this study was to assess the accuracy of a novel pedicle screw system.Methods: Thoracic and lumbar fusions were performed on 67 consecutive patients for tumor, trauma, degenerative disease or infection. A total of 326 pedicular screws were placed using a novel wire-guided, cannulated, polyaxial screw system (XIA Precision®, Stryker. The accuracy of placement was assessed post operatively by CT scan, and the patients were followed-up clinically for a mean of 16 months.Results: The total medio-caudal pedicle wall perforation rate was 9.2% (30/326. In 19 of these 30 cases a cortical breakthrough of less than 2 mm occurred. The misplacement rate (defined as a perforation of 2 mm or more was 3.37% (11/326. Three of these 11 screws needed surgical revision due to neurological symptoms or CSF leakage. There have been no screw breakages or dislocations over the follow up-period.Conclusion: We conclude that the use of this cannulated screw system for the placement of pedicle screws in the thoracic and lumbar spine is accurate and safe. The advantages of this technique include easy handling without a time-consuming set up. Considering the incidence of long-term screw breakage, further investigation with a longer follow-up period is necessary.Keywords: spinal instrumentation, pedicle screws, misplacement, pedicle wall perforation

Condylar position analysis with a new electronic condylar position measuring instrument E-CPM: influence of different examiners and a working bite on reproducibility.

Science.gov (United States)

Vahle-Hinz, K; Rybczynski, A; Jakstat, H; Ahlers, M O

2009-01-01

Condylar position analysis facilitates a quantitative comparison of the condylar position with and without a bite record, different records and changed influencing factors. Handling by the examiner when positioning the model is a significant factor with regard to the accuracy of the examination. Measurement accuracy could be improved when positioning the models by using special working bites, hence the objective of the experiments described in this study consisted in examining the extent to which the measuring results are influenced by different examiners and by using working bites. In the first trial, one examiner performed ten measurements without and with an interposed working bite for five model pairs in each case. In the second trial, nine examiners (three specialized dentists, three dental assistants, three students) performed ten measurements in each case without and with an interposed working bite. The three-dimensional position was read digitally with the E-CPM (Gamma Dental, Klosterneuburg/Vienna, Austria), recorded by means of spreadsheet software (Microsoft Excel) and diagnostic software (CMDfact, CMD3D module, dentaConcept, Hamburg), and evaluated with graphing software (Sigma Plot, Systat Software, USA). In the first trial, it was shown that the reproducibility of mounting was improved markedly (p <0.01) by using bite records in the form of working bites. In the second trial, it was shown that the mean error increased significantly (p <0.01) when several examiners performed the measurements compared with the results of one examiner alone. No significantly different results occurred (p < 0.01) in the comparison of the different groups of examiners with different educational and training backgrounds. This applied for the mounting methods without and with working bite. On the other hand, the reproducibility of mounting improved distinctly (p<0.01) in every group of examiners when working bites were used. Reproducibility of condylar position analysis was

Scaphoid Fracture Fixation with an Acutrak? Screw

OpenAIRE

Loving, Vilert A.; Richardson, Michael L.

2015-01-01

We report a case of fixation of a scaphoid fracture using an Acutrak? screw. This screw is cannulated and headless, which allows it to be implanted below the surface of the bone. It uses the same concept of variable thread pitch as the Herbert screw, but unlike the Herbert screw, is fully threaded, with continuously varying pitch along its length. This variable pitch creates constant compression across a fracture as the screw is advanced, and gives the screw its unique appearance. This featur...

TileCal TDAQ/DCS communication

CERN Document Server

Solans, C; Arabidze, G; Carneiro Ferreira, B; Sotto-Maior Peralva, B

2007-01-01

This document describes the communication between the TDAQ and DCS systems of the Hadronic Tile Calorimeter detector of the ATLAS experiment, currently under commissioning phase at CERN. It is a further step on the TDAQ and DCS communication for TileCal operation. The aim of the implementation is to increase the robustness and understanding of the detector from the two systems involved. The basic principle observed is that the two systems operate independently in parallel. Hence, the knowledge of the status of the whole detector from each of the two systems is required for further analysis of the archived data.

Orthodontic camouflage via total arch movement in a Class II with idiopathic condylar resorption

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Ji-Sung Jang

2014-01-01

Full Text Available Idiopathic condylar resorption (ICR, also known as idiopathic condylysis or condylar atrophy, is multifactorial pathology leading to severe mandibular retrognathism. The etiology has been shown to be multifactorial, such as avascular necrosis, traumatic injuries, hormone and autoimmune disease and it is largely difficult to distinguish the exact cause in each individual. In spite of the remarkable morphological alteration, surgical intervention is not readily recruited due to the possibility of recurrence of resorption. In order to restore balanced facial profile and occlusion. In this report, we present a camouflage treatment for skeletal Class II with ICR and facial asymmetry involving total arch movement, for the improvement facial profile and reconstruction of occlusion.

Can high-resolution peripheral quantitative computed tomography imaging of subchondral and cortical bone predict condylar fracture in Thoroughbred racehorses?

Science.gov (United States)

Trope, G D; Ghasem-Zadeh, A; Anderson, G A; Mackie, E J; Whitton, R C

2015-07-01

High-resolution 3D imaging may improve the prediction and/or early identification of condylar fractures of the distal metacarpus/tarsus and reduce the frequency of breakdown injury in racehorses. To test the hypotheses that horses suffering condylar fractures have higher bone volume fraction (BV/TV) of the distal metacarpal epiphysis, greater subchondral bone thickness at the fracture site and higher second moment of inertia in the metacarpal midshaft as identified with high-resolution 3D imaging. Cross-sectional study using cadaver material. Thoroughbreds that died on racetracks were grouped as: 1) horses with third metacarpal (McIII) fractures with a condylar component (cases, n = 13); 2) horses with no limb fracture (controls, n = 8); 3) horses with fractures in other bones or suspensory apparatus disruption (other fatal injuries, n = 16). The palmar condyles of McIII and the midshaft were examined with high resolution peripheral quantitative computed tomography (HR-pQCT). Statistical analysis included logistic regression and Spearman's correlation. There were no significant differences in BV/TV of distal McIII and second moment of inertia of the midshaft between cases and controls. Epiphyseal bone BV/TV was greater in injured limbs of horses with any fatal limb injury (Groups 1 and 3 combined) compared with controls (odds ratio = 1.20, 95% confidence interval 1.01-1.42, P = 0.034). An epiphyseal BV/TV>0.742 resulted in a sensitivity of 82.8% and specificity of 62.5% in identifying horses with fatal limb injury. In horses without condylar fracture, increased subchondral bone thickness was associated with palmar osteochondral disease lesions in the adjacent condyle (rs = 0.65, Phorses at risk of any fatal breakdown injury but not metacarpal condylar fractures. Measurement of parasagittal groove subchondral bone thickness is complicated by adjacent palmar osteochondral disease lesions. Thus, high-resolution imaging of the distal metacarpus appears to have limited

In vitro evaluation of force-expansion characteristics in a newly designed orthodontic expansion screw compared to conventional screws

Directory of Open Access Journals (Sweden)

Oshagh Morteza

2009-01-01

Full Text Available Objective : Expansion screws like Hyrax, Haas and other types, produce heavy interrupted forces which are unfavorable for dental movement and could be harmful to the tooth and periodontium. The other disadvantage of these screws is the need for patient cooperation for their regular activation. The purpose of this study was to design a screw and compare its force- expansion curve with other types. Materials and Methods : A new screw was designed and fabricated in the same dimension, with conventional types, with the ability of 8 mm expansion (Free wire length: 12 mm, initial compression: 4.5 mm, spring wire diameter: 0.4 mm, spring diameter: 3 mm, number of the coils: n0 ine, material: s0 tainless steel. In this in vitro study, the new screw was placed in an acrylic orthodontic appliance, and after mounting on a stone cast, the force-expansion curve was evaluated by a compression test machine and compared to other screws. Results : Force-expansion curve of designed screw had a flatter inclination compared to other screws. Generally it produced a light continuous force (two to 3.5 pounds for every 4 mm of expansion. Conclusion : In comparison with heavy and interrupted forces of other screws, the newly designed screw created light and continuous forces.

No association between types of unilateral mandibular condylar abnormalities and facial asymmetry in orthopedic-treated patients with juvenile idiopathic arthritis

DEFF Research Database (Denmark)

Stoustrup, Peter Bangsgaard; Ahlefeldt-Laurvig-Lehn, Nicole; Kristensen, Kasper Dahl

2018-01-01

with JIA. The contralateral TMJ was thereafter scored as either "normal," "deformed," or "erosive," consistent with predefined criteria. Based on the bilateral radiologic TMJ appearances, 3 JIA groups were assigned: normal/normal, normal/deformed, and normal/erosive. The severity of the dentofacial...... of the cone-beam computed tomography. Significantly greater dentofacial asymmetries were observed in the 2 groups of JIA patients with unilateral condylar abnormalities (deformation or erosion) than in the other groups. A similar degree of dentofacial asymmetry was observed in JIA patients with bilateral...... normal TMJs and in the nonarthritic control group. CONCLUSIONS: JIA patients with unilateral condylar abnormalities (deformation or erosion) exhibited significantly more severe dentofacial asymmetries than did the JIA patients without condylar abnormalities and the control subjects. We found the same...

A comparative study to evaluate the discrepancy in condylar guidance values between two commercially available arcon and non-arcon articulators: A clinical study

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Mukesh Kumar Goyal

2011-01-01

Full Text Available Aim: The purpose of this study was comparative evaluation of sagittal condylar values of arcon and non-arcon articulators with cephalometric readings and to determine the amount of discrepancy in sagittal condylar guidance values between arcon and non-arcon articulators using same protrusive record. Materials and Methods: Twenty subjects in the age group of 19-35 years, free from temporomandibular joint dysfunction, and occlusal disharmony, with healthy dentition participated in the study. Hanau H2 (non-arcon type and Hanau Wide-Vue (arcon type articulators were programmed for sagittal condylar guidance values using the same protrusive record made in polysiloxane bite registration material with edge to edge degree of protrusion. The resultant values for both the articulators on either side were compared with values obtained from tracing of digital lateral cephalogram using Kodak Dental imaging Window software 6.6.3.0-C program. The tabulated data were subjected to statistical analysis, ANOVA (Fishers ′F′ test for group comparison, Tukey′s HSD test for inter-comparison, student′s unpaired ′t′ test for intra-group comparison, and level of significance (P was calculated using the same. Results: The mean sagittal condylar guidance values of the three different groups were found to be very highly significant (P=0.001 and highly significant (P=0.002 on the right and left sides respectively. There was a very highly significant difference (P=0.001 and highly significant difference (P=0.003 between the arcon and non-arcon group on the right and left side respectively. No significant difference was found between the arcon and cephalometric group (P=0.284 right, P=0.853 left and a statistically significant difference was found between the non-arcon and cephalometric group (P=0.049 right, P=0.015 left. On intragroup comparison there was no statistically significant difference in sagittal condylar values on the right and left sides. Conclusion

Geothermal ORC Systems Using Large Screw Expanders

OpenAIRE

Biederman, Tim R.; Brasz, Joost J.

2014-01-01

Geothermal ORC Systems using Large Screw Expanders Tim Biederman Cyrq Energy Abstract This paper describes a low-temperature Organic Rankine Cycle Power Recovery system with a screw expander a derivative of developed of Kaishan's line of screw compressors, as its power unit. The screw expander design is a modified version of its existing refrigeration compressor used on water-cooled chillers. Starting the ORC development program with existing refrigeration screw compre...

The applicability of PEEK-based abutment screws.

Science.gov (United States)

Schwitalla, Andreas Dominik; Abou-Emara, Mohamed; Zimmermann, Tycho; Spintig, Tobias; Beuer, Florian; Lackmann, Justus; Müller, Wolf-Dieter

2016-10-01

The high-performance polymer PEEK (poly-ether-ether-ketone) is more and more being used in the field of dentistry, mainly for removable and fixed prostheses. In cases of screw-retained implant-supported reconstructions of PEEK, an abutment screw made of PEEK might be advantageous over a conventional metal screw due to its similar elasticity. Also in case of abutment screw fracture, a screw of PEEK could be removed more easily. M1.6-abutment screws of four different PEEK compounds were subjected to tensile tests to set their maximum tensile strengths in relation to an equivalent stress of 186MPa, which is aused by a tightening torque of 15Ncm. Two screw types were manufactured via injection molding and contained 15% short carbon fibers (sCF-15) and 40% (sCF-40), respectively. Two screw types were manufactured via milling and contained 20% TiO2 powder (TiO2-20) and >50% parallel orientated, continuous carbon fibers (cCF-50). A conventional abutments screw of Ti6Al4V (Ti; CAMLOG(®) abutment screw, CAMLOG, Wimsheim, Germany) served as control. The maximum tensile strength was 76.08±5.50MPa for TiO2-20, 152.67±15.83MPa for sCF-15, 157.29±20.11MPa for sCF-40 and 191.69±36.33MPa for cCF-50. The maximum tensile strength of the Ti-screws amounted 1196.29±21.4MPa. The results of the TiO2-20 and the Ti screws were significantly different from the results of the other samples, respectively. For the manufacturing of PEEK abutment screws, PEEK reinforced by >50% continuous carbon fibers would be the material of choice. Copyright © 2016 Elsevier Ltd. All rights reserved.

CT morphology and function of the condylar joints after conservative functional treatment of condylar fractures

International Nuclear Information System (INIS)

Eberhardt, K.; Sahm, G.

1990-01-01

In 8 adult and 13 adolescent individuals who had undergone conservative treatment for condylar fractures 4.2 and 4.5 years earlier, respectively computed tomography was performed. In addition, joint mobility was examined clinically in 18 of these patients. The results of the radiological examination allow discrimination between high-grade and low-grade remodeling and excessive bone formation. With one exception, high-grade remodeling was invariably observed after childhood fractures. In the adult patients new bone formation was rarely observed. Correlation between the mrophologic appearance and joint mobility was detectable only in cases of severely limited function. In the presence of less severe functional lesions, the size of the insertion area of the lateral pterygoid muscle might indicate the degree of functional rehabilitation. The radiological procedure is discussed. (orig.) [de

Pull out Strength of Dual Outer Diameter Pedicle Screws Compared to Uncemented and Cemented Standard Pedicle Screws: A Biomechanical in vitro Study.

Science.gov (United States)

Lorenz, Andrea; Leichtle, Carmen I; Frantz, Sandra; Bumann, Marte; Tsiflikas, Ilias; Shiozawa, Thomas; Leichtle, Ulf G

2017-05-01

To analyze the potential of the dual outer diameter screw and systematically evaluate the pull-out force of the dual outer diameter screw compared to the uncemented and cemented standard pedicle screws with special regard to the pedicle diameter and the vertebra level. Sixty vertebrae of five human spines (T 6 -L 5 ) were sorted into three study groups for pairwise comparison of the uncemented dual outer diameter screw, the uncemented standard screw, and the cemented standard screw, and randomized with respect to bone mineral density (BMD) and vertebra level. The vertebrae were instrumented, insertion torque was determined, and pull-out testing was performed using a material testing machine. Failure load was evaluated in pairwise comparison within each study group. The screw-to-pedicle diameter ratio was determined and the uncemented dual outer diameter and standard screws were compared for different ratios as well as vertebra levels. Significantly increased pull-out forces were measured for the cemented standard screw compared to the uncemented standard screw (+689 N, P dual outer diameter screw (+403 N, P dual outer diameter screw to the uncemented standard screw in the total study group, a distinct but not significant increase was measured (+149 N, P = 0.114). Further analysis of these two screws, however, revealed a significant increase of pull-out force for the dual outer diameter screw in the lumbar region (+247 N, P = 0.040), as well as for a screw-to-pedicle diameter ratio between 0.6 and 1 (+ 488 N, P = 0.028). For clinical application, cement augmentation remains the gold standard for increasing screw stability. According to our results, the use of a dual outer diameter screw is an interesting option to increase screw stability in the lumbar region without cement augmentation. For the thoracic region, however, the screw-to-pedicle diameter should be checked and attention should be paid to screw cut out, if the dual outer diameter screw is considered. �

A comparative evaluation of static and functional methods for recording centric relation and condylar guidance: a clinical study.

Science.gov (United States)

Thakur, Mridul; Jain, Veena; Parkash, Hari; Kumar, Pravesh

2012-09-01

To evaluate and compare the centric relation and horizontal condylar guidance using interocclusal wax and extra oral Gothic arch methods and subjective evaluation of dentures thus fabricated. Centric relation and horizontal condylar guidance was recorded by using interocclusal wax and gothic arch tracing in 28 completely edentulous patients. These records were transferred to the articulator and difference in both values was recorded. After that patients were divided in two groups according to the centric relation and horizontal condylar guidance recording method used to achieve balanced occlusion. Response of the dentures was subjectively evaluated using "Woelfel subjective evaluation criteria". Centric relation recorded by both the methods did coincide in 7.14 % of patients. Centric relation recorded by interocclusal wax was posterior to Gothic centric relation in 21.43 % of patients, and anterior to Gothic centric relation in 71.42 % patients. Gothic arch tracings gave higher mean guidance values on both the sides as compared to protrusive wax record in all the subjects, although the difference was statistically insignificant (P > 0.05). Subjective evaluation showed statistical insignificance for all the parameters in both groups. Gothic arch method records the centric relation at a more posterior position than the Static method, but it does not make any difference in clinical performance of the complete denture. Horizontal condylar guidance angle was approximately similar by both the methods.

Evaluation of the condylar movement on MRI during maximal mouth opening in patients with internal derangement of TMJ; comparison with transcranial view

International Nuclear Information System (INIS)

Cho, Bong Hae

2001-01-01

To evaluate the condylar movement at maximal mouth opening on MRI in patients with internal derangement. MR images and transcranial views for 102 TMJs in 51 patients were taken in closed and maximal opening positions, and the amount of condylar movement was analyzed annotatively and qualitatively. For MR images, the mean condylar movements were 9.4 mm horizontally, 4.6 mm vertically and 10.9 mm totally, while those for transcranial views were 12.5 mm, 4.6 mm, and 13.7 mm respectively. The condyle moved forward beyond the summit of the articular eminence in 41 TMJs (40.2%) for MR images than in transcranial views

Undertapping of Lumbar Pedicle Screws Can Result in Tapping With a Pitch That Differs From That of the Screw, Which Decreases Screw Pullout Force.

Science.gov (United States)

Bohl, Daniel D; Basques, Bryce A; Golinvaux, Nicholas S; Toy, Jason O; Matheis, Erika A; Bucklen, Brandon S; Grauer, Jonathan N

2015-06-15

Survey of spine surgeons and biomechanical comparison of screw pullout forces. To investigate what may be a suboptimal practice regularly occurring in spine surgery. In order for a tap to function in its intended manner, the pitch of the tap should be the same as the pitch of the screw. Undertapping has been shown to increase the pullout force of pedicle screws compared with line-to-line tapping. However, given the way current commercial lumbar pedicle screw systems are designed, undertapping may result in a tap being used that has a different pitch from that of the screw (incongruent pitch). A survey asked participants questions to estimate the proportion of cases each participant performed in the prior year using various hole preparation techniques. Participant responses were interpreted in the context of manufacturing specifications of specific instrumentation systems. Screw pullout forces were compared between undertapping with incongruent pitch and undertapping with congruent pitch using 0.16 g/cm polyurethane foam block and 6.5-mm screws. Of the 3679 cases in which participants reported tapping, participants reported line-to-line tapping in 209 cases (5%), undertapping with incongruent pitch in 1156 cases (32%), and undertapping with congruent pitch in 2314 cases (63%). The mean pullout force for undertapping with incongruent pitch was 56 N (8%) less than the mean pullout force for undertapping with congruent pitch. This is equivalent to 13 lb. This study estimates that for about 1 out of every 3 surgical cases with tapping of lumbar pedicle screws in the United States, hole preparation is being performed by undertapping with incongruent pitch. This study also shows that undertapping with incongruent pitch results in a decrease in pullout force by 8% compared with undertapping with congruent pitch. Steps should be taken to correct this suboptimal practice. 3.

Longitudinal tDCS: Consistency across Working Memory Training Studies

Directory of Open Access Journals (Sweden)

Marian E. Berryhill

2017-04-01

Full Text Available There is great interest in enhancing and maintaining cognitive function. In recent years, advances in noninvasive brain stimulation devices, such as transcranial direct current stimulation (tDCS, have targeted working memory in particular. Despite controversy surrounding outcomes of single-session studies, a growing field of working memory training studies incorporate multiple sessions of tDCS. It is useful to take stock of these findings because there is a diversity of paradigms employed and the outcomes observed between research groups. This will be important in assessing cognitive training programs paired with stimulation techniques and identifying the more useful and less effective approaches. Here, we treat the tDCS+ working memory training field as a case example, but also survey training benefits in other neuromodulatory techniques (e.g., tRNS, tACS. There are challenges associated with the broad parameter space including: individual differences, stimulation intensity, duration, montage, session number, session spacing, training task selection, timing of follow up testing, near and far transfer tasks. In summary, although the field of assisted cognitive training is young, some design choices are more favorable than others. By way of heuristic, the current evidence supports including more training/tDCS sessions (5+, applying anodal tDCS targeting prefrontal regions, including follow up testing on trained and transfer tasks after a period of no contact. What remains unclear, but important for future translational value is continuing work to pinpoint optimal values for the tDCS parameters on a per cognitive task basis. Importantly the emerging literature shows notable consistency in the application of tDCS for WM across various participant populations compared to single session experimental designs.

Indirect reduction with a condylar blade plate for osteosynthesis of subtrochanteric femoral fractures.

Science.gov (United States)

Siebenrock, K A; Müller, U; Ganz, R

1998-01-01

Subtrochanteric fractures frequently occur as high energy trauma usually in younger patients and may lead to severe comminution of the medial cortex. The medial cortex of the proximal femur is exposed to high compressive forces which make fracture stabilization a difficult problem. Bone healing may be seriously compromised due to extensive comminution and fragment devitalization. This requires reduction techniques which do not cause additional damage to the vitality of the bone. With indirect reduction techniques and the use of a condylar blade plate the results have been significantly improved in these fracture types in our department (1). In this report the essential aspects of indirect reduction for subtrochanteric fractures using a condylar blade plate and the treatment results from our department from earlier years (1) and from the last 2 1/2 years will be presented. In the latter period, fifteen patients with a mean age of 49 years (19-87 years) were treated with this method. Fractures resulted from traffic incidents or falls from a great height in 11 cases (73%). Union was achieved in 14 cases (93%) with full weight-bearing after a mean of 3 months (1-4 1/2 months). Malunion was seen in two cases (13%) without the need for further surgery. Non union occurred in one patient (7%) with a III B open injury due to early infection. After repeated debridements, bone grafting and decortication, the fracture was stabilized with a replacement condylar blade plate and healed uneventfully.

Pharyngeal Airway Space Changes After Condylar Replacement and Mandibular Advancement Surgery.

Science.gov (United States)

Yuen, Holly; Rossouw, P Emile; Wolford, Larry M; Wang, Hongyue

2018-01-03

The aim of this study was to examine the total volume and cross-sectional areas of the pharyngeal airway after bilateral condylar replacement and mandibular advancement surgery. A total of 137 patients (126 women and 11 men) underwent bilateral temporomandibular joint total joint replacement performed by 1 surgeon. A subsample of 30 patients who underwent condylar replacement and only mandibular advancement were evaluated for impact on the airway. Measurements were taken preoperatively, postoperatively, and at a follow-up 1 year after surgery on cone beam computed tomography scans. InVivoDental 3-dimensional imaging (Anatomage, San Jose, CA) was used to measure airway space regarding total volume (in cubic centimeters); minimum cross-sectional area (in square millimeters); minimum cross sections of the first, second, and third cervical vertebrae; and whether the patient had mandibular retrognathia before surgery. A second operator was used to test for interoperator error. Descriptive and bivariate statistics were computed, and the P value was set at .05. There was a significant increase in all measurements at the follow-up visit compared with the preoperative visit. There were no significant differences between groups based on simultaneous Le Fort I surgery, mandibular retrognathia, and gender. However, there were statistically significant differences in cross sections 1 and 2, as well as minimum cross-sectional area, regarding age. Condylar replacement and mandibular advancement have a significant association with an increase in airway space. The intraclass correlation coefficient showed excellent agreement between interoperator measurements. Patients undergoing bilateral temporomandibular joint replacement and mandibular advancement surgery showed an increase in pharyngeal airway space at a 1-year follow-up. In this study, age was significantly associated with the cross-sectional areas of the airway, with older patients having smaller values. Copyright © 2018

Measurement of Tip Apex Distance and Migration of Lag Screws and Novel Blade Screw Used for the Fixation of Intertrochanteric Fractures.

Directory of Open Access Journals (Sweden)

Jesse Chieh-Szu Yang

Full Text Available Fixation with a dynamic hip screw (DHS is one of the most common methods for stabilizing intertrochanteric fractures, except for unstable and reverse oblique fracture types. However, failure is often observed in osteoporotic patients whereby the lag screw effectively 'cuts out' through the weak bone. Novel anti-migration blades have been developed to be used in combination with a lag screw ('Blade Screw' to improve the fixation strength in osteoporotic intertrochanteric fractures. An in-vitro biomechanical study and a retrospective clinical study were performed to evaluate lag screw migration when using the novel Blade Screw and a traditional threaded DHS. The biomechanical study showed both the Blade Screw and DHS displayed excessive migration (≥10 mm before reaching 20,000 loading cycles in mild osteoporotic bone, but overall migration of the Blade Screw was significantly less (p ≤ 0.03. Among the patients implanted with a Blade Screw in the clinical study, there was no significant variation in screw migration at 3-months follow-up (P = 0.12. However, the patient's implanted with a DHS did display significantly greater migration (P<0.001 than those implanted with the Blade Screw. In conclusion, the Blade Screw stabilizes the bone fragments during dynamic loading so as to provide significantly greater resistance to screw migration in patients with mild osteoporosis.

Comparison of effectiveness between cork-screw and peg-screw electrodes for transcranial motor evoked potential monitoring using the finite element method.

Science.gov (United States)

Tomio, Ryosuke; Akiyama, Takenori; Ohira, Takayuki; Yoshida, Kazunari

2016-01-01

Intraoperative monitoring of motor evoked potentials by transcranial electric stimulation is popular in neurosurgery for monitoring motor function preservation. Some authors have reported that the peg-screw electrodes screwed into the skull can more effectively conduct current to the brain compared to subdermal cork-screw electrodes screwed into the skin. The aim of this study was to investigate the influence of electrode design on transcranial motor evoked potential monitoring. We estimated differences in effectiveness between the cork-screw electrode, peg-screw electrode, and cortical electrode to produce electric fields in the brain. We used the finite element method to visualize electric fields in the brain generated by transcranial electric stimulation using realistic three-dimensional head models developed from T1-weighted images. Surfaces from five layers of the head were separated as accurately as possible. We created the "cork-screws model," "1 peg-screw model," "peg-screws model," and "cortical electrode model". Electric fields in the brain radially diffused from the brain surface at a maximum just below the electrodes in coronal sections. The coronal sections and surface views of the brain showed higher electric field distributions under the peg-screw compared to the cork-screw. An extremely high electric field was observed under cortical electrodes. Our main finding was that the intensity of electric fields in the brain are higher in the peg-screw model than the cork-screw model.

Factors affecting femoral rotational angle based on the posterior condylar axis in gap-based navigation-assisted total knee arthroplasty for valgus knee.

Science.gov (United States)

Lee, Sung-Sahn; Lee, Yong-In; Kim, Dong-Uk; Lee, Dae-Hee; Moon, Young-Wan

2018-01-01

Achieving proper rotational alignment of the femoral component in total knee arthroplasty (TKA) for valgus knee is challenging because of lateral condylar hypoplasia and lateral cartilage erosion. Gap-based navigation-assisted TKA enables surgeons to determine the angle of femoral component rotation (FCR) based on the posterior condylar axis. This study evaluated the possible factors that affect the rotational alignment of the femoral component based on the posterior condylar axis. Between 2008 and 2016, 28 knees were enrolled. The dependent variable for this study was FCR based on the posterior condylar axis, which was obtained from the navigation system archives. Multiple regression analysis was conducted to identify factors that might predict FCR, including body mass index (BMI), Kellgren-Lawrence grade (K-L grade), lateral distal femoral angles obtained from the navigation system and radiographs (NaviLDFA, XrayLDFA), hip-knee-ankle (HKA) axis, lateral gap under varus stress (LGVS), medial gap under valgus stress (MGVS), and side-to-side difference (STSD, MGVS - LGVS). The mean FCR was 6.1° ± 2.0°. Of all the potentially predictive factors evaluated in this study, only NaviLDFA (β = -0.668) and XrayLDFA (β = -0.714) predicted significantly FCR. The LDFAs, as determined using radiographs and the navigation system, were both predictive of the rotational alignment of the femoral component based on the posterior condylar axis in gap-based TKA for valgus knee. A 1° increment with NaviLDFA led to a 0.668° decrement in FCR, and a 1° increment with XrayLDFA led to a 0.714° decrement. This suggests that symmetrical lateral condylar hypoplasia of the posterior and distal side occurs in lateral compartment end-stage osteoarthritis with valgus deformity.

DCS data viewer, an application that accesses ATLAS DCS historical data

International Nuclear Information System (INIS)

Tsarouchas, C; Schlenker, S; Dimitrov, G; Jahn, G

2014-01-01

The ATLAS experiment at CERN is one of the four Large Hadron Collider experiments. The Detector Control System (DCS) of ATLAS is responsible for the supervision of the detector equipment, the reading of operational parameters, the propagation of the alarms and the archiving of important operational data in a relational database (DB). DCS Data Viewer (DDV) is an application that provides access to the ATLAS DCS historical data through a web interface. Its design is structured using a client-server architecture. The pythonic server connects to the DB and fetches the data by using optimized SQL requests. It communicates with the outside world, by accepting HTTP requests and it can be used stand alone. The client is an AJAX (Asynchronous JavaScript and XML) interactive web application developed under the Google Web Toolkit (GWT) framework. Its web interface is user friendly, platform and browser independent. The selection of metadata is done via a column-tree view or with a powerful search engine. The final visualization of the data is done using java applets or java script applications as plugins. The default output is a value-over-time chart, but other types of outputs like tables, ascii or ROOT files are supported too. Excessive access or malicious use of the database is prevented by a dedicated protection mechanism, allowing the exposure of the tool to hundreds of inexperienced users. The current configuration of the client and of the outputs can be saved in an XML file. Protection against web security attacks is foreseen and authentication constrains have been taken into account, allowing the exposure of the tool to hundreds of users world wide. Due to its flexible interface and its generic and modular approach, DDV could be easily used for other experiment control systems.

Dcs Data Viewer, an Application that Accesses ATLAS DCS Historical Data

Science.gov (United States)

Tsarouchas, C.; Schlenker, S.; Dimitrov, G.; Jahn, G.

2014-06-01

The ATLAS experiment at CERN is one of the four Large Hadron Collider experiments. The Detector Control System (DCS) of ATLAS is responsible for the supervision of the detector equipment, the reading of operational parameters, the propagation of the alarms and the archiving of important operational data in a relational database (DB). DCS Data Viewer (DDV) is an application that provides access to the ATLAS DCS historical data through a web interface. Its design is structured using a client-server architecture. The pythonic server connects to the DB and fetches the data by using optimized SQL requests. It communicates with the outside world, by accepting HTTP requests and it can be used stand alone. The client is an AJAX (Asynchronous JavaScript and XML) interactive web application developed under the Google Web Toolkit (GWT) framework. Its web interface is user friendly, platform and browser independent. The selection of metadata is done via a column-tree view or with a powerful search engine. The final visualization of the data is done using java applets or java script applications as plugins. The default output is a value-over-time chart, but other types of outputs like tables, ascii or ROOT files are supported too. Excessive access or malicious use of the database is prevented by a dedicated protection mechanism, allowing the exposure of the tool to hundreds of inexperienced users. The current configuration of the client and of the outputs can be saved in an XML file. Protection against web security attacks is foreseen and authentication constrains have been taken into account, allowing the exposure of the tool to hundreds of users world wide. Due to its flexible interface and its generic and modular approach, DDV could be easily used for other experiment control systems.

Fixation strength of biocomposite wedge interference screw in ACL reconstruction: effect of screw length and tunnel/screw ratio. A controlled laboratory study

Directory of Open Access Journals (Sweden)

Herrera Antonio

2010-06-01

Full Text Available Abstract Background Primary stability of the graft is essential in anterior cruciate ligament surgery. An optimal method of fixation should be easy to insert and provide great resistance against pull-out forces. A controlled laboratory study was designed to test the primary stability of ACL tendinous grafts in the tibial tunnel. The correlation between resistance to traction forces and the cross-section and length of the screw was studied. Methods The tibial phase of ACL reconstruction was performed in forty porcine tibias using digital flexor tendons of the same animal. An 8 mm tunnel was drilled in each specimen and two looped tendons placed as graft. Specimens were divided in five groups according to the diameter and length of the screw used for fixation. Wedge interference screws were used. Longitudinal traction was applied to the graft with a Servohydraulic Fatigue System. Load and displacement were controlled and analyzed. Results The mean loads to failure for each group were 295,44 N (Group 1; 9 × 23 screw, 564,05 N (Group 2; 9 × 28, 614,95 N (Group 3; 9 × 35, 651,14 N (Group 4; 10 × 28 and 664,99 (Group 5; 10 × 35. No slippage of the graft was observed in groups 3, 4 and 5. There were significant differences in the load to failure among groups (ANOVA/P Conclusions Longer and wider interference screws provide better fixation in tibial ACL graft fixation. Short screws (23 mm do not achieve optimal fixation and should be implanted only with special requirements.

A clinico-radiographic study to compare and co-relate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in completely edentulous patients.

Science.gov (United States)

Shetty, Sanath; Kunta, Mythili; Shenoy, Kamalakanth

2018-01-01

The purpose of this study was to compare and correlate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in edentulous patients. Twelve completely edentulous patients were selected by the inclusion and exclusion criteria. Conventional steps in the fabrication of complete denture till jaw relation were carried out. Intraoral gothic arch tracing and protrusive interocclusal records were obtained for each patient. Protrusive interocclusal record was used to program the Hanau Wide-Vue semi-adjustable articulator, thus obtaining the sagittal condylar guidance angle. Using RadiAnt DICOM software, on the orthopantomogram obtained for each patient in the study, two reference lines were drawn. The Frankfort's horizontal plane and the mean curvature line (joining the most superior and the inferior points on the glenoid fossa curvature) were drawn. The mean curvature line was extended to intersect the Frankfort's horizontal plane, thus obtaining the radiographic sagittal condylar guidance angle. The condylar guidance angles obtained by these two methods were compared and subjected to paired t -test. There was no statistically significant difference between the sagittal condylar guidance angles obtained between right and left sides with intraoral gothic arch tracing and radiographic methods ( P = 0.107 and 0.07, respectively). Within the limitations of this study, it was concluded that the protrusive condylar guidance angles obtained by panoramic radiograph may be used for programming semi-adjustable articulators.

Communication between Trigger/DAQ and DCS in ATLAS

International Nuclear Information System (INIS)

Burckhart, H.; Jones, R.; Hart, R.; Khomoutnikov, V.; Ryabov, Y.

2001-01-01

Within the ATLAS experiment Trigger/DAQ and DCS are both logically and physically separated. Nevertheless there is a need to communicate. The initial problem definition and analysis suggested three subsystems the Trigger/DAQ DCS Communication (DDC) project should support the ability to: 1. exchange data between Trigger/DAQ and DCS; 2. send alarm messages from DCS to Trigger/DAQ; 3. issue commands to DCS from Trigger/DAQ. Each subsystem is developed and implemented independently using a common software infrastructure. Among the various subsystems of the ATLAS Trigger/DAQ the Online is responsible for the control and configuration. It is the glue connecting the different systems such as data flow, level 1 and high-level triggers. The DDC uses the various Online components as an interface point on the Trigger/DAQ side with the PVSS II SCADA system on the DCS side and addresses issues such as partitioning, time stamps, event numbers, hierarchy, authorization and security. PVSS II is a commercial product chosen by CERN to be the SCADA system for all LHC experiments. Its API provides full access to its database, which is sufficient to implement the 3 subsystems of the DDC software. The DDC project adopted the Online Software Process, which recommends a basic software life-cycle: problem statement, analysis, design, implementation and testing. Each phase results in a corresponding document or in the case of the implementation and testing, a piece of code. Inspection and review take a major role in the Online software process. The DDC documents have been inspected to detect flaws and resulted in a improved quality. A first prototype of the DDC is ready and foreseen to be used at the test-beam during summer 2001

Corticospinal excitability changes to anodal tDCS elucidated with NIRS-EEG joint-imaging

DEFF Research Database (Denmark)

Jindal, Utkarsh; Sood, Mehak; Chowdhury, Shubhajit Roy

2015-01-01

Transcranial direct current stimulation (tDCS) has been shown to modulate corticospinal excitability. We used near-infrared spectroscopy (NIRS) - electroencephalography (EEG) joint-imaging during and after anodal tDCS to measure changes in mean cerebral haemoglobin oxygen saturation (rSO2) along...... with changes in the log-transformed mean-power of EEG within 0.5 Hz - 11.25 Hz. In two separate studies, we investigated local post-tDCS alterations from baseline at the site of anodal tDCS using NIRS-EEG/tDCS joint-imaging as well as local post-tDCS alterations in motor evoked potentials (MEP...... that the innovative technologies for portable NIRS-EEG neuroimaging may be leveraged to objectively quantify the progress (e.g., corticospinal excitability alterations) and dose tDCS intervention as an adjuvant treatment during neurorehabilitation....

The ATLAS Tile Calorimeter DCS for Run 2

CERN Document Server

Pedro Martins, Filipe Manuel; The ATLAS collaboration

2016-01-01

TileCal is one of the ATLAS sub-detectors operating at the Large Hadron Collider (LHC), which is taking data since 2010. The Detector Control System (DCS) was developed to ensure the coherent and safe operation of the whole ATLAS detector. Seventy thousand (70000) parameters are used for control and monitoring purposes of TileCal, requiring an automated system. The TileCal DCS is mainly responsible for the control and monitoring of the high and low voltage systems but it also supervises the detector infrastructure (cooling and racks), calibration systems, data acquisition and safety. During the first period of data taking (Run 1, 2010-12) the TileCal DCS allowed a smooth detector operation and should continue to do so for the second period (Run 2) that started in 2015. The TileCal DCS was updated in order to cope with the hardware and software requirements for Run 2 operation. These updates followed the general ATLAS guidelines on the software and hardware upgrade but also the new requirements from the TileCa...

The ATLAS Tile Calorimeter DCS for Run 2

CERN Document Server

Pedro Martins, Filipe Manuel; The ATLAS collaboration

2016-01-01

TileCal is one of the ATLAS subdetectors operating at the Large Hadron Collider (LHC), which is taking data since 2010. Seventy thousand (70000) parameters are used for control and monitoring purposes, requiring an automated system. The Detector Control System (DCS) was developed to ensure the coherent and safe operation of the whole ATLAS detector. The TileCal DCS is mainly responsible for the control and monitoring of the high and low voltage systems but it also supervises the detector infrastructure (cooling and racks), calibration systems, data acquisition and safety. During the first period of data taking (Run 1, 2010-12) the TileCal DCS allowed a smooth detector operation and should continue to do so for the second period (Run 2) that started in 2015. The TileCal DCS was updated in order to cope with the hardware and software requirements for Run 2 operation. These updates followed the general ATLAS guidelines on the software and hardware upgrade but also the new requirements from the TileCal detector. ...

Parameter Optimization Analysis of Prolonged Analgesia Effect of tDCS on Neuropathic Pain Rats

Science.gov (United States)

Wen, Hui-Zhong; Gao, Shi-Hao; Zhao, Yan-Dong; He, Wen-Juan; Tian, Xue-Long; Ruan, Huai-Zhen

2017-01-01

Background: Transcranial direct current stimulation (tDCS) is widely used to treat human nerve disorders and neuropathic pain by modulating the excitability of cortex. The effectiveness of tDCS is influenced by its stimulation parameters, but there have been no systematic studies to help guide the selection of different parameters. Objective: This study aims to assess the effects of tDCS of primary motor cortex (M1) on chronic neuropathic pain in rats and to test for the optimal parameter combinations for analgesia. Methods: Using the chronic neuropathic pain models of chronic constriction injury (CCI), we measured pain thresholds before and after anodal-tDCS (A-tDCS) using different parameter conditions, including stimulation intensity, stimulation time, intervention time and electrode located (ipsilateral or contralateral M1 of the ligated paw on male/female CCI models). Results: Following the application of A-tDCS over M1, we observed that the antinociceptive effects were depended on different parameters. First, we found that repetitive A-tDCS had a longer analgesic effect than single stimulus, and both ipsilateral-tDCS (ip-tDCS) and contralateral-tDCS (con-tDCS) produce a long-lasting analgesic effect on neuropathic pain. Second, the antinociceptive effects were intensity-dependent and time-dependent, high intensities worked better than low intensities and long stimulus durations worked better than short stimulus durations. Third, timing of the intervention after injury affected the stimulation outcome, early use of tDCS was an effective method to prevent the development of pain, and more frequent intervention induced more analgesia in CCI rats, finally, similar antinociceptive effects of con- and ip-tDCS were observed in both sexes of CCI rats. Conclusion: Optimized protocols of tDCS for treating antinociceptive effects were developed. These findings should be taken into consideration when using tDCS to produce analgesic effects in clinical applications. PMID

ATLAS Muon DCS Upgrades and Optimizations

CERN Document Server

Bakalis, Christos; The ATLAS collaboration

2017-01-01

The Muon subsystem is comprised of four detector types: Resistive Plate Chambers (RPC) and Thin Gap Chambers (TGC) for trigger purposes, and Cathode Strip Chambers (CSC) and Muon Drift Tubes (MDT) for muon track reconstruction. The MDTs cover a large area at the outer part of the detector. In total, there are over a 1’000 MDT chambers, which are made of about 350’000 tubes. The luminosity upgrade of the HL-LHC is expected to pose a serious challenge to the MDTs. The expected increase of particle flux will set new, higher standards regarding the operation and control of the chambers. A step towards optimizing the ATLAS Muon Detector Control System (DCS) was to develop several DCS tools, namely a High Luminosity vs Trip Limit panel with its accompanying scripts and managers. The ultimate goal of this tool is to protect the MDT chambers from the rising particle flux and its associated increase in chamber current. In addition to optimizing the ATLAS Muon DCS, several tasks to accommodate the newly installed B...

Cryopreservation of adenovirus-transfected dendritic cells (DCs) for clinical use.

Science.gov (United States)

Gülen, D; Maas, S; Julius, H; Warkentin, P; Britton, H; Younos, I; Senesac, J; Pirruccello, Samuel M; Talmadge, J E

2012-05-01

In this study, we examined the effects of cryoprotectant, freezing and thawing, and adenovirus (Adv) transduction on the viability, transgene expression, phenotype, and function of human dendritic cells (DCs). DCs were differentiated from cultured peripheral blood (PB) monocytes following Elutra isolation using granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) for 6 days and then transduced using an Adv vector with an IL-12 transgene. Fresh, cryopreserved, and thawed transduced immature DCs were examined for their: 1) cellular concentration and viability; 2) antigenicity using an allogeneic mixed lymphocyte reaction (MLR); 3) phenotype (HLA-DR and CD11c) and activation (CD83); and 4) transgene expression based on IL-12 secretion. Stability studies revealed that transduced DCs could be held in cryoprotectant for as long as 75 min at 2-8°C prior to freezing with little effect on their viability and cellularity. Further, cryopreservation, storage, and thawing reduced the viability of the transduced DCs by an average of 7.7%; and had no significant impact on DC phenotype and activation. In summary, cryopreservation, storage, and thawing had no significant effect on DC viability, function, and transgene expression by Adv-transduced DCs. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of open reduction versus minimally invasive surgical approaches on screw position in canine sacroiliac lag-screw fixation.

Science.gov (United States)

Déjardin, Loïc M; Marturello, Danielle M; Guiot, Laurent P; Guillou, Reunan P; DeCamp, Charles E

2016-07-19

To compare accuracy and consistency of sacral screw placement in canine pelves treated for sacroiliac luxation with open reduction and internal fixation (ORIF) or minimally invasive osteosynthesis (MIO) techniques. Unilateral sacroiliac luxations created experimentally in canine cadavers were stabilized with an iliosacral lag screw applied via ORIF or MIO techniques (n = 10/group). Dorsoventral and craniocaudal screw angles were measured using computed tomography multiplanar reconstructions in transverse and dorsal planes, respectively. Ratios between pilot hole length and sacral width (PL/SW-R) were obtained. Data between groups were compared statistically (p sacroiliac luxations provides more accurate and consistent sacral screw placement than ORIF. With proper techniques, iatrogenic neurological damage can be avoided with both techniques. The PL /SW-R, which relates to safe screw fixation, also demonstrates that screw penetration of at least 60% of the sacral width is achievable regardless of surgical approach. These findings, along with the limited dissection needed for accurate sacral screw placement, suggest that MIO of sacroiliac luxations is a valid alternative to ORIF.

Percutaneous anterior C1/2 transarticular screw fixation: salvage of failed percutaneous odontoid screw fixation for odontoid fracture

OpenAIRE

Wu, Ai-Min; Jin, Hai-Ming; Lin, Zhong-Ke; Chi, Yong-Long; Wang, Xiang-Yang

2017-01-01

Background The objective of this study is to investigate the outcomes and safety of using percutaneous anterior C1/2 transarticular screw fixation as a salvage technique for odontoid fracture if percutaneous odontoid screw fixation fails. Methods Fifteen in 108 odontoid fracture patients (planned to be treated by percutaneous anterior odontoid screw fixation) were failed to introduce satisfactory odontoid screw trajectory. To salvage this problem, we chose the percutaneous anterior C1/2 trans...

Bidirectional interactions between neuronal and hemodynamic responses to transcranial direct current stimulation (tDCS: challenges for brain-state dependent tDCS

Directory of Open Access Journals (Sweden)

Anirban eDutta

2015-08-01

Full Text Available Transcranial direct current stimulation (tDCS has been shown to modulate cortical neural activity. During neural activity, the electric currents from excitable membranes of brain tissue superimpose in the extracellular medium and generate a potential at scalp, which is referred as the electroencephalogram (EEG. Respective neural activity (energy demand has been shown to be closely related, spatially and temporally, to cerebral blood flow (CBF that supplies glucose (energy supply via neurovascular coupling. The hemodynamic response can be captured by near-infrared spectroscopy (NIRS, which enables continuous monitoring of cerebral oxygenation and blood volume. This neurovascular coupling phenomenon led to the concept of neurovascular unit (NVU that consists of the endothelium, glia, neurons, pericytes, and the basal lamina. Here, recent works suggest NVU as an integrated system working in concert using feedback mechanisms to enable proper brain homeostasis and function where the challenge remains in capturing these mostly nonlinear spatiotemporal interactions within NVU during tDCS. Therefore, we propose EEG-NIRS-based whole-head monitoring of tDCS-induced neuronal and hemodynamic alterations for brain-state dependent tDCS.

Evaluation of the Effect of Fixation Angle between Polyaxial Pedicle Screw Head and Rod on the Failure of Screw-Rod Connection

Directory of Open Access Journals (Sweden)

Engin Çetin

2015-01-01

Full Text Available Introduction. Polyaxial screws had been only tested according to the ASTM standards (when they were perpendicularly positioned to the rod. In this study, effects of the pedicle screws angled fixation to the rod on the mechanical properties of fixation were investigated. Materials and Method. 30 vertically fixed screws and 30 screws fixed with angle were used in the study. Screws were used in three different diameters which were 6.5 mm, 7.0 mm, and 7.5 mm, in equal numbers. Axial pull-out and flexion moment tests were performed. Test results compared with each other using appropriate statistical methods. Results. In pull-out test, vertically fixed screws, in 6.5 mm and 7.0 mm diameter, had significantly higher maximum load values than angled fixed screws with the same diameters (P<0.01. Additionally, vertically fixed screws, in all diameters, had significantly greater stiffness according to corresponding size fixed with angle (P<0.005. Conclusion. Fixing the pedicle screw to the rod with angle significantly decreased the pull-out stiffness in all diameters. Similarly, pedicle screw instrumentation fixed with angle decreased the minimum sagittal angle between the rod and the screw in all diameters for flexion moment test but the differences were not significant.

Standard Waste Box Lid Screw Removal Option Testing

International Nuclear Information System (INIS)

Anast, Kurt Roy

2016-01-01

This report provides results from test work conducted to resolve the removal of screws securing the standard waste box (SWB) lids that hold the remediated nitrate salt (RNS) drums. The test work evaluated equipment and process alternatives for removing the 42 screws that hold the SWB lid in place. The screws were secured with a red Loctite thread locker that makes removal very difficult because the rivets that the screw threads into would slip before the screw could be freed from the rivet, making it impossible to remove the screw and therefore the SWB lid.

Standard Waste Box Lid Screw Removal Option Testing

Energy Technology Data Exchange (ETDEWEB)

Anast, Kurt Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-03-11

This report provides results from test work conducted to resolve the removal of screws securing the standard waste box (SWB) lids that hold the remediated nitrate salt (RNS) drums. The test work evaluated equipment and process alternatives for removing the 42 screws that hold the SWB lid in place. The screws were secured with a red Loctite thread locker that makes removal very difficult because the rivets that the screw threads into would slip before the screw could be freed from the rivet, making it impossible to remove the screw and therefore the SWB lid.

Misplaced Cervical Screws Requiring Reoperation.

Science.gov (United States)

Peterson, Jeremy C; Arnold, Paul M; Smith, Zachary A; Hsu, Wellington K; Fehlings, Michael G; Hart, Robert A; Hilibrand, Alan S; Nassr, Ahmad; Rahman, Ra'Kerry K; Tannoury, Chadi A; Tannoury, Tony; Mroz, Thomas E; Currier, Bradford L; De Giacomo, Anthony F; Fogelson, Jeremy L; Jobse, Bruce C; Massicotte, Eric M; Riew, K Daniel

2017-04-01

A multicenter, retrospective case series. In the past several years, screw fixation of the cervical spine has become commonplace. For the most part, this is a safe, low-risk procedure. While rare, screw backout or misplaced screws can lead to morbidity and increased costs. We report our experiences with this uncommon complication. A multicenter, retrospective case series was undertaken at 23 institutions in the United States. Patients were included who underwent cervical spine surgery from January 1, 2005, to December 31, 2011, and had misplacement of screws requiring reoperation. Institutional review board approval was obtained at all participating institutions, and detailed records were sent to a central data center. A total of 12 903 patients met the inclusion criteria and were analyzed. There were 11 instances of screw backout requiring reoperation, for an incidence of 0.085%. There were 7 posterior procedures. Importantly, there were no changes in the health-related quality-of-life metrics due to this complication. There were no new neurologic deficits; a patient most often presented with pain, and misplacement was diagnosed on plain X-ray or computed tomography scan. The most common location for screw backout was C6 (36%). This study represents the largest series to tabulate the incidence of misplacement of screws following cervical spine surgery, which led to revision procedures. The data suggest this is a rare event, despite the widespread use of cervical fixation. Patients suffering this complication can require revision, but do not usually suffer neurologic sequelae. These patients have increased cost of care. Meticulous technique and thorough knowledge of the relevant anatomy are the best means of preventing this complication.

Visualizing Transcranial Direct Current Stimulation (tDCS) in vivo using Magnetic Resonance Imaging

Science.gov (United States)

Jog, Mayank Anant

Transcranial Direct Current Stimulation (tDCS) is a low-cost, non-invasive neuromodulation technique that has been shown to treat clinical symptoms as well as improve cognition. However, no techniques exist at the time of research to visualize tDCS currents in vivo. This dissertation presents the theoretical framework and experimental implementations of a novel MRI technique that enables non-invasive visualization of the tDCS electric current using magnetic field mapping. The first chapter establishes the feasibility of measuring magnetic fields induced by tDCS currents. The following chapter discusses the state of the art implementation that can measure magnetic field changes in individual subjects undergoing concurrent tDCS/MRI. The final chapter discusses how the developed technique was integrated with BOLD fMRI-an established MRI technique for measuring brain function. By enabling a concurrent measurement of the tDCS current induced magnetic field as well as the brain's hemodynamic response to tDCS, our technique opens a new avenue to investigate tDCS mechanisms and improve targeting.

Are We Underestimating the Significance of Pedicle Screw Misplacement?

Science.gov (United States)

Sarwahi, Vishal; Wendolowski, Stephen F; Gecelter, Rachel C; Amaral, Terry; Lo, Yungtai; Wollowick, Adam L; Thornhill, Beverly

2016-05-01

A retrospective review of charts, x-rays (XRs) and computed tomography (CT) scans was performed. To evaluate the accuracy of pedicle screw placement using a novel classification system to determine potentially significant screw misplacement. The accuracy rate of pedicle screw (PS) placement varies from 85% to 95% in the literature. This demonstrates technical ability but does not represent the impact of screw misplacement on individual patients. This study quantifies the rate of screw misplacement on a per-patient basis to highlight its effect on potential morbidity. A retrospective review of charts, XRs and low-dose CT scans of 127 patients who underwent spinal fusion with pedicle screws for spinal deformity was performed. Screws were divided into four categories: screws at risk (SAR), indeterminate misplacements (IMP), benign misplacements (BMP), accurately placed (AP). A total of 2724 screws were placed in 127 patients. A total of 2396 screws were placed accurately (87.96%). A total of 247 screws (9.07%) were BMP, 52 (1.91%) were IMP, and 29 (1.06%) were considered SAR. Per-patient analysis showed 23 (18.11%) of patients had all screws AP. Thirty-five (27.56%) had IMP and 18 (14.17%) had SAR. Risk factor analysis showed smaller Cobb angles increased likelihood of all screws being AP. Sub-analysis of adolescent idiopathic scoliotic patients showed no curve or patient characteristic that correlated with IMP or SAR. Over 40% of patients had screws with either some/major concern. Overall reported screw misplacement is low, but it does not reflect the potential impact on patient morbidity. Per-patient analysis reveals more concerning numbers toward screw misplacement. With increasing pedicle screw usage, the number of patients with misplaced screws will likely increase proportionally. Better strategies need to be devised for evaluation of screw placement, including establishment of a national database of deformity surgery, use of intra-operative image guidance, and

Evaluation for nuclear safety-critical software reliability of DCS

International Nuclear Information System (INIS)

Liu Ying

2015-01-01

With the development of control and information technology at NPPs, software reliability is important because software failure is usually considered as one form of common cause failures in Digital I and C Systems (DCS). The reliability analysis of DCS, particularly qualitative and quantitative evaluation on the nuclear safety-critical software reliability belongs to a great challenge. To solve this problem, not only comprehensive evaluation model and stage evaluation models are built in this paper, but also prediction and sensibility analysis are given to the models. It can make besement for evaluating the reliability and safety of DCS. (author)

Tricortical cervical inter-body screw fixation.

Directory of Open Access Journals (Sweden)

Goel A

1997-01-01

Full Text Available A new tricortical method of screw implantation for anterior cervical interbody plate fixation is described. The screws are placed obliquely such that they engage the anterior cortex of the body and traverse through the cortices adjoining the disc space. By this method the screws not only hold the plate firmly with a tricortical purchase, but by virtue of their course stabilize the two adjoining vertebral bodies by themselves. Sixteen patients were treated by this method. In three of these cases only tricortical screws without the metal plate were used for fixation. The advantages of the technique are discussed.

Surface EEG-Transcranial Direct Current Stimulation (tDCS) Closed-Loop System.

Science.gov (United States)

Leite, Jorge; Morales-Quezada, Leon; Carvalho, Sandra; Thibaut, Aurore; Doruk, Deniz; Chen, Chiun-Fan; Schachter, Steven C; Rotenberg, Alexander; Fregni, Felipe

2017-09-01

Conventional transcranial direct current stimulation (tDCS) protocols rely on applying electrical current at a fixed intensity and duration without using surrogate markers to direct the interventions. This has led to some mixed results; especially because tDCS induced effects may vary depending on the ongoing level of brain activity. Therefore, the objective of this preliminary study was to assess the feasibility of an EEG-triggered tDCS system based on EEG online analysis of its frequency bands. Six healthy volunteers were randomized to participate in a double-blind sham-controlled crossover design to receive a single session of 10[Formula: see text]min 2[Formula: see text]mA cathodal and sham tDCS. tDCS trigger controller was based upon an algorithm designed to detect an increase in the relative beta power of more than 200%, accompanied by a decrease of 50% or more in the relative alpha power, based on baseline EEG recordings. EEG-tDCS closed-loop-system was able to detect the predefined EEG magnitude deviation and successfully triggered the stimulation in all participants. This preliminary study represents a proof-of-concept for the development of an EEG-tDCS closed-loop system in humans. We discuss and review here different methods of closed loop system that can be considered and potential clinical applications of such system.

Parameter Optimization Analysis of Prolonged Analgesia Effect of tDCS on Neuropathic Pain Rats

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Hui-Zhong Wen

2017-06-01

Full Text Available Background: Transcranial direct current stimulation (tDCS is widely used to treat human nerve disorders and neuropathic pain by modulating the excitability of cortex. The effectiveness of tDCS is influenced by its stimulation parameters, but there have been no systematic studies to help guide the selection of different parameters.Objective: This study aims to assess the effects of tDCS of primary motor cortex (M1 on chronic neuropathic pain in rats and to test for the optimal parameter combinations for analgesia.Methods: Using the chronic neuropathic pain models of chronic constriction injury (CCI, we measured pain thresholds before and after anodal-tDCS (A-tDCS using different parameter conditions, including stimulation intensity, stimulation time, intervention time and electrode located (ipsilateral or contralateral M1 of the ligated paw on male/female CCI models.Results: Following the application of A-tDCS over M1, we observed that the antinociceptive effects were depended on different parameters. First, we found that repetitive A-tDCS had a longer analgesic effect than single stimulus, and both ipsilateral-tDCS (ip-tDCS and contralateral-tDCS (con-tDCS produce a long-lasting analgesic effect on neuropathic pain. Second, the antinociceptive effects were intensity-dependent and time-dependent, high intensities worked better than low intensities and long stimulus durations worked better than short stimulus durations. Third, timing of the intervention after injury affected the stimulation outcome, early use of tDCS was an effective method to prevent the development of pain, and more frequent intervention induced more analgesia in CCI rats, finally, similar antinociceptive effects of con- and ip-tDCS were observed in both sexes of CCI rats.Conclusion: Optimized protocols of tDCS for treating antinociceptive effects were developed. These findings should be taken into consideration when using tDCS to produce analgesic effects in clinical

Comparison of various approaches for the treatment of fractures of the mandibular condylar process.

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Handschel, Jörg; Rüggeberg, Tim; Depprich, Rita; Schwarz, Frank; Meyer, Ulrich; Kübler, Norbert R; Naujoks, Christian

2012-12-01

Fractures of the mandibular condyle process are the most common fractures of the lower jaw. Unfortunately, the type of treatment is still a matter of debate. The aim of this investigation was to compare the outcome of different treatment approaches regarding function and surgical side-effects. 111 fractures of the mandibular condyle representing all types according to the classification of Spiessl and Schroll were included. Both closed reduction (CR) and open reduction with internal fixation (ORIF) including the retromandibular/transparotid, submandibular, preauricular and intraoral approach were performed. The clinical examination included functional and aesthetic aspects at least 1 year after the fracture. The majority of fractures (45%) were classified into Type II and IV according to Spiessl and Schroll followed by fractures without any displacement or dislocation (29.7%). The submandibular approach showed the worst outcome regarding permanent palsy of the facial nerve and hypertrophic scarring. No significant differences between the various approaches were detected in the functional status in any diagnosis group. Inferior condylar neck fractures benefit from ORIF by an intraoral approach whereas in high condylar neck fractures the retromandibular/transparotid approach shows the best results. Fractures of the condylar head were almost all treated by CR and our results cannot contribute to the debate of CR vs. ORIF in this type of fracture. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Bone scanning with /sup 99m/Tc phosphate to assess condylar hyperplasia. Report of two cases

International Nuclear Information System (INIS)

Matteson, S.R.; Proffit, W.R.; Terry, B.C.; Staab, E.V.; Burkes, E.J. Jr.

1985-01-01

Condylar hyperplasia poses a problem in planning treatment because it is a self-limiting process for some but not all patients. Continued growth creates a progressive deformity that requires condylectomy, whereas an enlarged condyle can be left in place after hyperplastic growth ceases, even if ramus surgery is needed to correct asymmetry. Bone scan with /sup 99m/Tc phosphate can be used to assist in making the differential diagnosis. In the two patients reported here, abnormal metabolic activity revealed by bone scans supported clinical and historical evidence that the condylar hyperplasia was active and required surgical correction, including condylectomy. The two cases demonstrate different approaches to postsurgical orthodontic treatment, depending on the amount of normal growth expected

Effects of transcranial direct current stimulation (tDCS) on binge eating disorder.

Science.gov (United States)

Burgess, Emilee E; Sylvester, Maria D; Morse, Kathryn E; Amthor, Frank R; Mrug, Sylvie; Lokken, Kristine L; Osborn, Mary K; Soleymani, Taraneh; Boggiano, Mary M

2016-10-01

To investigate the effect of transcranial direct current stimulation (tDCS) on food craving, intake, binge eating desire, and binge eating frequency in individuals with binge eating disorder (BED). N = 30 adults with BED or subthreshold BED received a 20-min 2 milliampere (mA) session of tDCS targeting the dorsolateral prefrontal cortex (DLPFC; anode right/cathode left) and a sham session. Food image ratings assessed food craving, a laboratory eating test assessed food intake, and an electronic diary recorded binge variables. tDCS versus sham decreased craving for sweets, savory proteins, and an all-foods category, with strongest reductions in men (p tDCS also decreased total and preferred food intake by 11 and 17.5%, regardless of sex (p tDCS administration (p tDCS in BED. Stimulation of the right DLPFC suggests that enhanced cognitive control and/or decreased need for reward may be possible functional mechanisms. The results support investigation of repeated tDCS as a safe and noninvasive treatment adjunct for BED. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2016; 49:930-936). © 2016 Wiley Periodicals, Inc.

Accuracy of computer-assisted cervicle pedicle screw installation

International Nuclear Information System (INIS)

Zhang Honglei; Zhou Dongsheng; Jang Zhensong

2009-01-01

Objective: To investigate the accuracy of computer-assisted cervical pedicle screw installation and the reason of screw malposition. Methods: A total of 172 cervical pedicle screws were installed by computer-assisted navigation for 30 patients with lower cervical spinal diseases. All the patients were examined by X-ray and CT after operation. Screw's position and direction were measured on the sagittal and transectional images of intraoperative navigation and post-operative CT. Then linear regression analysis was taken between navigational and post-operative CT's images. Results: Two screws perforated the upper pedicle wall, 3 perforated the lateral pedicle wall.There was a positive linear correlation between navigational and post-operative CT's images. Conclusion: Computer-assisted navigation can provide the high accuracy of cervical pedicle screw installation and excursion phenomenon is reason of screw malposition. (authors)

Comparison of Expansive Pedicle Screw and Polymethylmethacrylate-Augmented Pedicle Screw in Osteoporotic Sheep Lumbar Vertebrae: Biomechanical and Interfacial Evaluations

OpenAIRE

Liu, Da; Zhang, Yi; Zhang, Bo; Xie, Qing-yun; Wang, Cai-ru; Liu, Jin-biao; Liao, Dong-fa; Jiang, Kai; Lei, Wei; Pan, Xian-ming

2013-01-01

BACKGROUND: It was reported that expansive pedicle screw (EPS) and polymethylmethacrylate-augmented pedicle screw (PMMA-PS) could be used to increase screw stability in osteoporosis. However, there are no studies comparing the two kinds of screws in vivo. Thus, we aimed to compare biomechanical and interfacial performances of EPS and PMMA-PS in osteoporotic sheep spine. METHODOLOGY/PRINCIPAL FINDINGS: After successful induction of osteoporotic sheep, lumbar vertebrae in each sheep were random...

Postero-inferior condylar movement induced by artificial occlusal interference on the balancing side during fictive mastication in rabbits.

Science.gov (United States)

Morita, Takumi; Hiraba, Katsunari; Matsunaga, Tomoko; Ito, Yu; Maruo, Hisanobu; Kurita, Kenichi

2016-06-01

Tooth contact does not occur on the balancing side during mastication. Hence, it is possible that the presence of occlusal interference on the balancing side causes mandibular rotation followed by atypical condylar movement because the jaw-closing muscle activity on the working side is greater than on the balancing side. The aim of the present study was to investigate the relationship between occlusal contact on the balancing side and condylar movement during mastication. EMG activity of the masseter (MS), lateral pterygoid (LP) and digastric (DG) muscles and jaw movements were recorded. Condylar movements in the sagittal plane were recorded using a high speed charge-coupled device (CCD) camera. Incisal point movements were recorded using a magnet on the mentum and a magnetometric sensor on the nasal bone. A removable biting plate was used to introduce an artificial occlusal interference on the balancing side. Nine of the 10 rabbits showed large postero-inferior condylar movement (Pi-Cm) when a biting plate was applied on the balancing side. Five rabbits showed very small Pi-Cm when a biting plate was applied on the balancing side. In the small Pi-Cm group, MS activity decreased markedly and LP and DG transient activity appeared in the early occlusal phase in the presence of the biting plate. Interference on the balancing side always caused Pi-Cm on the ipsilateral side during mastication. However, the degree of Pi-Cm was often decreased by a jaw opening reflex response. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surgical treatment of adolescent internal condylar resorption (AICR) with articular disc repositioning and orthognathic surgery in the growing patient?a pilot study

OpenAIRE

Bodine, Trevor P.; Wolford, Larry M.; Araujo, Eustaquio; Oliver, Donald R.; Buschang, Peter H.

2016-01-01

Abstract Background The aim of this study was to better understand how surgical repositioning and stabilization of anteriorly displaced articular discs using the Mitek mini-anchor technique affects condylar growth in growing patients with adolescent internal condylar resorption (AICR). Methods Twenty-two adolescent patients diagnosed with AICR and anterior temporomandibular disc displacement were compared to untreated control subjects without AICR matched for age, sex, and Angle classificatio...

Understanding public (misunderstanding of tDCS for enhancement

Directory of Open Access Journals (Sweden)

Laura Yenisa Cabrera

2015-04-01

Full Text Available In order to gain insight into the public’s perspective on using the minimally invasive technique transcranial direct current stimulation (tDCS as an enhancement tool, we analyzed and compared online comments in key popular press articles from two different periods (pre-commercialization and post-commercialization. The main conclusion drawn from this exploratory investigation is that public perception regarding tDCS has shifted from misunderstanding to cautionary realism. This change in attitude can be explained as moving from a focus on an emergent technology to a focus on its applications, benefits, and risks as the technology becomes more grounded within the public domain. Future governance of tDCS should include the concerns and enthusiasms of the public.Keywords: cognitive enhancement, neuroethics, public understanding, transcranial direct current stimulation, brain stimulation, public policy.

Simple Technique for Removing Broken Pedicular Screws

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A Agrawal

2014-03-01

Full Text Available The procedure for removing a broken pedicle screw should ideally be technically easy and minimally invasive, as any damage to the pedicle, during removal of the broken screw, may weaken the pedicle, thus compromising on the success of re-instrumentation. We describe the case of a 32-year old man who had undergone surgery for traumatic third lumbar vertebral body fracture three years prior to current admission and had developed the complication of pedicle screw breakage within the vertebral body. The patient underwent re-exploration and removal of the distal screws. Through a paravertebral incision and muscle separation, the screws and rods were exposed and the implants were removed.

The effect of different screw-rod design on the anti-rotational torque: a biomechanical comparison of three conventional screw-rod constructs.

Science.gov (United States)

Huang, Zifang; Wang, Chongwen; Fan, Hengwei; Sui, Wenyuan; Li, Xueshi; Wang, Qifei; Yang, Junlin

2017-07-28

Screw-rod constructs have been widely used to correct spinal deformities, but the effects of different screw-rod systems on anti-rotational torque have not been determined. This study aimed to analyze the biomechanical effect of different rod-screw constructs on anti-rotational torque. Three conventional spinal screw-rod systems (Legacy, RF-F-10 and USSII) were used to test the anti-rotational torque in the material test machine. ANOVA was performed to evaluate the anti-rotational capacity of different pedicle screws-rod constructs. The anti-rotational torque of Legacy group, RF-F-10 group and USSII group were 12.3 ± 1.9 Nm, 6.8 ± 0.4 Nm, and 3.9 ± 0.8 Nm, with a P value lower than 0.05. This results indicated that the Legacy screws-rod construct could provide a highest anti-rotation capacity, which is 68% and 210% greater than RF-F-10 screw-rod construct and USSII screw-rod respectively. The anti-rotational torque may be mainly affected by screw cap and groove design. Our result showed the anti-rotational torque are: Legacy system > RF-F-10 system > USSII system, suggesting that appropriate rod-screw constructs selection in surgery may be vital for anti-rotational torque improvement and preventing derotation correction loss.

Delayed plastic responses to anodal tDCS in older adults

Directory of Open Access Journals (Sweden)

Hakuei eFujiyama

2014-06-01

Full Text Available Despite the abundance of research reporting the neurophysiological and behavioral effects of transcranial direct current stimulation (tDCS in healthy young adults and clinical populations, the extent of potential neuroplastic changes induced by tDCS in healthy older adults is not well understood. The present study compared the extent and time course of anodal tDCS-induced plastic changes in primary motor cortex (M1 in young and older adults. Furthermore, as it has been suggested that neuroplasiticity and associated learning depends on the brain-derived neurotrophic factor (BDNF gene polymorphisms, we also assessed the impact of BDNF polymorphism on these effects. Corticospinal excitability was examined using transcranial magnetic stimulation before and following (0, 10, 20, 30 min anodal tDCS (30 min, 1 mA or sham in young and older adults. While the overall extent of increases in corticospinal excitability induced by anodal tDCS did not vary reliably between young and older adults, older adults exhibited a delayed response; the largest increase in corticospinal excitability occurred 30 min following stimulation for older adults, but immediately post-stimulation for the young group. BDNF genotype did not result in significant differences in the observed excitability increases for either age group. The present study suggests that tDCS-induced plastic changes are delayed as a result of healthy aging, but that the overall efficacy of the plasticity mechanism remains unaffected.

Screw piles for cold climate foundations

Energy Technology Data Exchange (ETDEWEB)

Schmidt, R.; Sakr, M. [Almita Manufacturing Ltd., Edmonton, AB (Canada)

2008-07-01

Almita Manufacturing is an Alberta-based company that designs and builds screw piles with its own installation teams. It also engineers and supplies piles to numerous other companies and independent installers. The company services industries such as oil and gas; power transmission and distribution; and commercial construction. This presentation discussed the design and technical aspects of screw piles. A screw pile was defined as a steel pipe shaft with a 45 degree cut at the bottom and a formed helical plate welded to the outside of the pipe near the base and at a selected point on the shaft. The pile is screwed into the ground with a planetary drive head of suitable torque rating. The helical plate or helix helps facilitate the installation of the pile and gives the screw pile increased bearing capacity and pull-out resistance over a traditional straight-shaft pile. Screw piles were compared against cast in place concrete piles and steel driven piles. Screw piles were reported to have no tailings; no concrete curing time; no rebar, anchor belts, and no liners; and no dewatering. Screw piles can also be installed in all types of weather. Rhe Cree Burn Camp case study near Fort McMurray, Alberta was also presented. This residential camp and recreation complex consists of pre-fabricated units that make up three storey housing buildings and a single floor multi-use building. The case study provided information on soil; design parameter inputs; load testing program and pile configuration; geotechnical and structural design results; compression load test arrangement; pile test setup; and test results. The presentation also discussed fabrication as well as installation equipment. Various applications were also presented through a series of project pictures. Last, the presentation provided a simple cost analysis. tabs., figs.

Complications of syndesmotic screw removal

NARCIS (Netherlands)

T. Schepers (Tim); E.M.M. van Lieshout (Esther); M.R. de Vries (Mark); M. van der Elst (Maarten)

2011-01-01

textabstractBackground: Currently, the metallic syndesmotic screw is the gold standard in the treatment of syndesmotic disruption. Whether or not this screw needs to be removed remains debatable. The aim of the current study was to determine the complications which occur following routine removal of

Repair of a pediatric bilateral condylar and symphyseal fracture using a transfacial Steinman pin.

Science.gov (United States)

Grow, Jacob N; Flores, Roberto L; Tholpady, Sunil S

2014-01-01

The proper management of complex pediatric mandibular fractures remains a topic of debate because of the relatively uncommon presentation of these fractures, combined with concerns related with deciduous teeth, tooth buds, and growth inhibition. In this current study, we present a novel approach to the repair of bilateral condylar fractures with concomitant symphyseal fracture in a 4-year-old girl. Manual closed reduction was first obtained, followed by placement of a transfacial Steinman pin through the angles of the mandible and placement of circummandibular wires. Maxillomandibular fixation remained for 2 weeks and the Steinman pin was removed after 11 weeks. At 3 months of postsurgical follow-up, the patient displayed class I occlusion, facial symmetry, full range of jaw motion, and absence of deviation or pain on full oral excursion. Radiographic findings also revealed complete resolution of the symphyseal fracture with appropriate condylar healing and alignment.

Hydrostatic Compress Force Enhances the Viability and Decreases the Apoptosis of Condylar Chondrocytes through Integrin-FAK-ERK/PI3K Pathway

Science.gov (United States)

Ma, Dandan; Kou, Xiaoxing; Jin, Jing; Xu, Taotao; Wu, Mengjie; Deng, Liquan; Fu, Lusi; Liu, Yi; Wu, Gang; Lu, Haiping

2016-01-01

Reduced mechanical stimuli in many pathological cases, such as hemimastication and limited masticatory movements, can significantly affect the metabolic activity of mandibular condylar chondrocytes and the growth of mandibles. However, the molecular mechanisms for these phenomena remain unclear. In this study, we hypothesized that integrin-focal adhesion kinase (FAK)-ERK (extracellular signal–regulated kinase)/PI3K (phosphatidylinositol-3-kinase) signaling pathway mediated the cellular response of condylar chondrocytes to mechanical loading. Primary condylar chondrocytes were exposed to hydrostatic compressive forces (HCFs) of different magnitudes (0, 50, 100, 150, 200, and 250 kPa) for 2 h. We measured the viability, morphology, and apoptosis of the chondrocytes with different treatments as well as the gene, protein expression, and phosphorylation of mechanosensitivity-related molecules, such as integrin α2, integrin α5, integrin β1, FAK, ERK, and PI3K. HCFs could significantly increase the viability and surface area of condylar chondrocytes and decrease their apoptosis in a dose-dependent manner. HCF of 250 kPa resulted in a 1.51 ± 0.02-fold increase of cell viability and reduced the ratio of apoptotic cells from 18.10% ± 0.56% to 7.30% ± 1.43%. HCFs could significantly enhance the mRNA and protein expression of integrin α2, integrin α5, and integrin β1 in a dose-dependent manner, but not ERK1, ERK2, or PI3K. Instead, HCF could significantly increase phosphorylation levels of FAK, ERK1/2, and PI3K in a dose-dependent manner. Cilengitide, the potent integrin inhibitor, could dose-dependently block such effects of HCFs. HCFs enhances the viability and decreases the apoptosis of condylar chondrocytes through the integrin-FAK-ERK/PI3K pathway. PMID:27827993

Assessment of Condylar Changes in Patients with Temporomandibular Joint Pain Using Digital Volumetric Tomography

International Nuclear Information System (INIS)

Shetty, U.Sh.; Burde, K.N.; Naikmasur, V.G.; Sattur, A.P.

2014-01-01

Objective. To evaluate the efficiency of DVT in comparison with OPG in the assessment of bony condylar changes in patients of TMJ pain. Methods. 100 temporomandibular joints of 62 patients with the complaint of temporomandibular joint pain were included in the study. DVT and OPG radiographs were taken for all the 100 joints. Three observers interpreted the DVT and OPG radiograph for the bony changes separately for two times with an interval of one week. The bony changes seen in the condyle were given coding from 0 to 6. (0: Normal, 1: Erosion, 2: Flattening, 3: Osteophyte, 4: Sclerosis, 5: Resorption, and 6: other changes). Interobserver and intra observer variability was assessed with one-way Anoka statistics. Z test was used to see the significant difference between OPG and DVT. Results. In the present study the inter examiner reliability for Og and DVT was 0.903 and 0.978, respectively. Intra examiner reliability for OPG and DVT was 0.908 and 0.980, respectively. The most common condylar bony change seen in OPG and DVT was erosion followed by flattening and osteophyte. There was significant difference between OPG and DVT in detecting erosion and osteophytes. The other changes observed in our study were Elys cyst, pointed condyle, and bifid condyle. All the bony changes are more commonly seen in females than males. Conclusion. DVT provides more valid and accurate information on condylar bony changes. The DVT has an added advantage of lesser radiation exposure to the patient and cost effectiveness and could be easily accessible in a dental hospital

Assessment of Condylar Changes in Patients with Temporomandibular Joint Pain Using Digital Volumetric Tomography

Directory of Open Access Journals (Sweden)

Ujwala Shivarama Shetty

2014-01-01

Full Text Available Objective. To evaluate the efficiency of DVT in comparison with OPG in the assessment of bony condylar changes in patients of TMJ pain. Methods. 100 temporomandibular joints of 62 patients with the complaint of temporomandibular joint pain were included in the study. DVT and OPG radiographs were taken for all the 100 joints. Three observers interpreted the DVT and OPG radiograph for the bony changes separately for two times with an interval of one week. The bony changes seen in the condyle were given coding from 0 to 6. (0: Normal, 1: Erosion, 2: Flattening, 3: Osteophyte, 4: Sclerosis, 5: Resorption, and 6: other changes. Interobserver and intraobserver variability was assessed with one-way ANOVA statistics. Z test was used to see the significant difference between OPG and DVT. Results. In the present study the interexaminer reliability for OPG and DVT was 0.903 and 0.978, respectively. Intraexaminer reliability for OPG and DVT was 0.908 and 0.980, respectively. The most common condylar bony change seen in OPG and DVT was erosion followed by flattening and osteophyte. There was significant difference between OPG and DVT in detecting erosion and osteophytes. The other changes observed in our study were Ely’s cyst, pointed condyle, and bifid condyle. All the bony changes are more commonly seen in females than males. Conclusion. DVT provides more valid and accurate information on condylar bony changes. The DVT has an added advantage of lesser radiation exposure to the patient and cost effectiveness and could be easily accessible in a dental hospital.

Configuration-defined control algorithms with the ASDEX Upgrade DCS

Energy Technology Data Exchange (ETDEWEB)

Treutterer, Wolfgang, E-mail: Wolfgang.Treutterer@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Cole, Richard [Unlimited Computer Systems, Seeshaupter Str. 15, 82393 Iffeldorf Germany (Germany); Gräter, Alexander [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Lüddecke, Klaus [Unlimited Computer Systems, Seeshaupter Str. 15, 82393 Iffeldorf Germany (Germany); Neu, Gregor; Rapson, Christopher; Raupp, Gerhard; Zehetbauer, Thomas [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

2016-11-15

Highlights: • Control algorithm built from combination of pre-fabricated standard function blocks. • Seamless integration in multi-threaded computation context. • Block composition defined by configuration data, only. - Abstract: The ASDEX Upgrade Discharge Control System (DCS) is a distributed real-time control system executing complex control and monitoring tasks. Up to now, DCS control algorithms have been implemented by coding dedicated application processes with the C++ programming language. Algorithm changes required code modification, compilation and commissioning which only experienced programmers could perform. This was a significant constraint of flexibility for both control system operation and design. The new approach extends DCS with the capability of configuration-defined control algorithms. These are composed of chains of small, configurable standard function blocks providing general purpose functions like algebraic operations, filters, feedback controllers, output limiters and decision logic. In a later phase a graphical editor could help to compose and modify such configuration in a Simulink-like fashion. Building algorithms from standard functions can result in a high number of elements. In order to achieve a similar performance as with C++ coding, it is essential to avoid administrative bottlenecks by design. As a consequence, DCS executes a function block chain in the context of a single real-time thread of an application process. No concurrency issues as in a multi-threaded context need to be considered resulting in strongly simplified signal handling and zero performance overhead for inter-block communication. Instead of signal-driven synchronization, a block scheduler derives the execution sequence automatically from the block dependencies as defined in the configuration. All blocks and connecting signals are instantiated dynamically, based on definitions in a configuration file. Algorithms thus are not defined in the code but only in

Influence of Concurrent Finger Movements on Transcranial Direct Current Stimulation (tDCS)-Induced Aftereffects.

Science.gov (United States)

Shirota, Yuichiro; Terney, Daniella; Antal, Andrea; Paulus, Walter

2017-01-01

Transcranial direct current stimulation (tDCS) has been reported to have bidirectional influence on the amplitude of motor-evoked potentials (MEPs) in resting participants in a polarity-specific manner: anodal tDCS increased and cathodal tDCS decreased them. More recently, the effects of tDCS have been shown to depend on a number of additional factors. We investigated whether a small variety of movements involving target and non-target muscles could differentially modify the efficacy of tDCS. MEPs were elicited from the right first dorsal interosseous muscle, defined as the target muscle, by single pulse transcranial magnetic stimulation (TMS) over the primary motor cortex (M1). During M1 tDCS, which lasted for 10 min applying anodal, cathodal, or sham condition, the participants were instructed to squeeze a ball with their right hand (Task 1), to move their right index finger only in the medial (Task 2), in the lateral direction (Task 3), or in medial and lateral direction alternatively (Task 4). Anodal tDCS reduced MEP amplitudes measured in Task 1 and Task 2, but to a lesser extent in the latter. In Task 3, anodal tDCS led to greater MEP amplitudes than cathodal stimulation. Alternating movements resulted in no effect of tDCS on MEP amplitude (Task 4). The results are congruent with the current notion that the aftereffects of tDCS are highly variable relying on a number of factors including the type of movements executed during stimulation.

Transcranial Direct Current Stimulation (tDCS): A Promising Treatment for Major Depressive Disorder?

Science.gov (United States)

Bennabi, Djamila; Haffen, Emmanuel

2018-01-01

Background: Transcranial direct current stimulation (tDCS) opens new perspectives in the treatment of major depressive disorder (MDD), because of its ability to modulate cortical excitability and induce long-lasting effects. The aim of this review is to summarize the current status of knowledge regarding tDCS application in MDD. Methods: In this review, we searched for articles published in PubMed/MEDLINE from the earliest available date to February 2018 that explored clinical and cognitive effects of tDCS in MDD. Results: Despite differences in design and stimulation parameters, the examined studies indicated beneficial effects of tDCS for MDD. These preliminary results, the non-invasiveness of tDCS, and its good tolerability support the need for further research on this technique. Conclusions: tDCS constitutes a promising therapeutic alternative for patients with MDD, but its place in the therapeutic armamentarium remains to be determined. PMID:29734768

Dual-worm screw compressors; Compresseurs bi-vis

Energy Technology Data Exchange (ETDEWEB)

Baleydier, J P [Bitzer France, 69 - Lyon (France)

1998-12-31

Low power worm-screw moto-compressors are used in any king of refrigerating machineries and more and more in air conditioning systems. This paper presents the principle of dual-screw moto-compressors: worm-screw technology, role of oil (lubrication, tightness, cooling), compression, internal pressure, power reduction, lubrication, economizer, operation, model selection and accessories. (J.S.)

Dual-worm screw compressors; Compresseurs bi-vis

Energy Technology Data Exchange (ETDEWEB)

Baleydier, J.P. [Bitzer France, 69 - Lyon (France)

1997-12-31

Low power worm-screw moto-compressors are used in any king of refrigerating machineries and more and more in air conditioning systems. This paper presents the principle of dual-screw moto-compressors: worm-screw technology, role of oil (lubrication, tightness, cooling), compression, internal pressure, power reduction, lubrication, economizer, operation, model selection and accessories. (J.S.)

New cooling regulation technology of secondary cooling station in DCS

Energy Technology Data Exchange (ETDEWEB)

Zhou, Xuan; Yan, Jun-wei; Zhu, Dong-sheng; Liu, Fei-long; Lei, Jun-xi [The Key Lab of Enhanced Heat Transfer and Energy Conservation of Ministry of Education, School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510641 (China); Liang, Lie-quan [The Key Lab of E-Commerce Market Application Technology of Guangdong Province, Guangdong University of Business Studies, Guangzhou 510320 (China)

2008-07-01

In this paper, a kind of new control technology of secondary cooling station (constant flow rate/variable temperature difference) in district cooling system (DCS) is proposed in view of serial consequences including low efficiency and high operating cost caused by low temperature of supply water in DCS. This technology has been applied in DCS of Guangzhou University City. The result has already indicated that such technology can increase the supply and return temperatures of buildings, return water temperature of primary side in the plate heat exchanger unit, moreover, the efficiency of both the chiller and the whole system are improved significantly. (author)

Vertical-Screw-Auger Conveyer Feeder

Science.gov (United States)

Walton, Otis (Inventor); Vollmer, Hubert J. (Inventor)

2016-01-01

A conical feeder is attached to a vertically conveying screw auger. The feeder is equipped with scoops and rotated from the surface to force-feed regolith the auger. Additional scoops are possible by adding a cylindrical section above the conical funnel section. Such then allows the unit to collect material from swaths larger in diameter than the enclosing casing pipe of the screw auger. A third element includes a flexible screw auger. All three can be used in combination in microgravity and zero atmosphere environments to drill and recover a wide area of subsurface regolith and entrained volatiles through a single access point on the surface.

FUNCTIONAL OUTCOME OF SUPRACONDYLAR FRACTURES OF FEMUR MANAGED BY OPEN REDUCTION AND INTERNAL FIXATION WITH LOCKING COMPRESSION PLATE

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Madhusudhana

2015-10-01

Full Text Available INTRODUCTION : Incidence of distal femur fractures is approximately 37 per 1 , 00,000 person - years.¹Distal femoral fractures has two different injury mechanisms, high energy trauma and low energy trauma. In high - energy trauma, the problem of restoring the function in a destroyed knee joint persists. Complex knee ligament injuries frequently occur additionally to extensive cartilage injuries. In elderly patients, extreme osteoporosis represents a particular problem for anchoring the implant. 2 Supracondylar and inter condylar fractures often are unstable and comminuted and tend to occur in the elderly or those with multiple injuries. Treatment options are many with varied results. The final outcome would depend upon the type of fracture, stabilization of fixation and and perhaps patient general condition. 3 The options for operative treatment are traditional plating techniques that require compression of the implant to the femoral shaft (blade plate, Dynamic Condylar Screw, non - locking condylar buttress plate, antegrade nailing fixation, retrograde nailing, sub muscular locked internal fixation and external fixation. 4 However, as the complexity of fractures needing treatment has changed from simple extra - articular supra - condylar types to inter - condylar and metaphyseal comminuted types, these implants may not be ideal. Double plating, and more recently, locked plating techniques have been advocated 5 . However with double plating there is often extensive soft tissue stripping on both sides of the femur, resulting in reduced blood supply and potential non - union and failure of the implants 6 . The LCP is a single beam construct where the strength of its fixation is equal to the sum of all screw - bone interfaces rather than a single screw’s axial stiffness or pullout resistance as seen in unlocked plates 7,8 . Its unique biomechanical function is based on splinting rather than compression resulting in flexible stabilization

Anatomical Parameters of tDCS to Modulate the Motor System after Stroke: A Review

Science.gov (United States)

Lefebvre, Stephanie; Liew, Sook-Lei

2017-01-01

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method to modulate the local field potential in neural tissue and consequently, cortical excitability. As tDCS is relatively portable, affordable, and accessible, the applications of tDCS to probe brain–behavior connections have rapidly increased in the last 10 years. One of the most promising applications is the use of tDCS to modulate excitability in the motor cortex after stroke and promote motor recovery. However, the results of clinical studies implementing tDCS to modulate motor excitability have been highly variable, with some studies demonstrating that as many as 50% or more of patients fail to show a response to stimulation. Much effort has therefore been dedicated to understand the sources of variability affecting tDCS efficacy. Possible suspects include the placement of the electrodes, task parameters during stimulation, dosing (current amplitude, duration of stimulation, frequency of stimulation), individual states (e.g., anxiety, motivation, attention), and more. In this review, we first briefly review potential sources of variability specific to stroke motor recovery following tDCS. We then examine how the anatomical variability in tDCS placement [e.g., neural target(s) and montages employed] may alter the neuromodulatory effects that tDCS exerts on the post-stroke motor system. PMID:28232816

Coupling DCS and MARTe: two real-time control frameworks in collaboration

Energy Technology Data Exchange (ETDEWEB)

Rapson, Christopher J., E-mail: chris.rapson@ipp.mpg.de [Max Planck Institute for Plasma Physics, Boltzmannstrasse 2, 85748 Garching (Germany); Carvalho, Pedro [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Lüddecke, Klaus; Neto, André C. [Unlimited Computer Systems GmbH, Seeshaupterstr. 15, 82393 Iffeldorf (Germany); Santos, Bruno [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Treutterer, Wolfgang [Max Planck Institute for Plasma Physics, Boltzmannstrasse 2, 85748 Garching (Germany); Winter, Axel [ITER Organization, Route de Vinon-sur-Verdon, 13115 St.-Paul-Lès-Durance (France); Zehetbauer, Thomas [Max Planck Institute for Plasma Physics, Boltzmannstrasse 2, 85748 Garching (Germany)

2014-12-15

Highlights: • Similarities and differences between DCS and MARTe. • Identifies the state-of-the-art in terms of software frameworks for fusion control. • Interfaces developed for realtime and non-realtime communication between DCS and MARTe. • An algorithm replicated in DCS and MARTe produces identical results and good performance. • The start of collaboration to develop a new framework for ITER PCS. - Abstract: Fusion experiments place high demands on real-time control systems. Within the fusion community two modern framework-based software architectures have emerged as powerful tools for developing algorithms for real-time control of complex systems while maintaining the flexibility required when operating a physics experiment. The two frameworks are known as DCS (Discharge Control System), from ASDEX Upgrade and MARTe (Multithreaded Application Real-Time executor), originally from JET. Based on the success of DCS and MARTe, ITER has chosen to develop a framework architecture for its Plasma Control System which will adopt major design concepts from both the existing frameworks. This paper describes a coupling of the two existing frameworks, which was undertaken to explore the degree of similarity and compliance between the concepts, and to extend their capabilities. DCS and MARTe operate in parallel with synchronised state machines and a common message logger. Configuration data is exchanged before the real-time phase. During the real-time phase, structured data is exchanged via shared memory and an existing DCS algorithm is replicated within MARTe. The coupling tests the flexibility and identifies the respective strengths of the two frameworks, providing a well-informed basis on which to move forward and design a new ITER real-time framework.

Coupling DCS and MARTe: two real-time control frameworks in collaboration

International Nuclear Information System (INIS)

Rapson, Christopher J.; Carvalho, Pedro; Lüddecke, Klaus; Neto, André C.; Santos, Bruno; Treutterer, Wolfgang; Winter, Axel; Zehetbauer, Thomas

2014-01-01

Highlights: • Similarities and differences between DCS and MARTe. • Identifies the state-of-the-art in terms of software frameworks for fusion control. • Interfaces developed for realtime and non-realtime communication between DCS and MARTe. • An algorithm replicated in DCS and MARTe produces identical results and good performance. • The start of collaboration to develop a new framework for ITER PCS. - Abstract: Fusion experiments place high demands on real-time control systems. Within the fusion community two modern framework-based software architectures have emerged as powerful tools for developing algorithms for real-time control of complex systems while maintaining the flexibility required when operating a physics experiment. The two frameworks are known as DCS (Discharge Control System), from ASDEX Upgrade and MARTe (Multithreaded Application Real-Time executor), originally from JET. Based on the success of DCS and MARTe, ITER has chosen to develop a framework architecture for its Plasma Control System which will adopt major design concepts from both the existing frameworks. This paper describes a coupling of the two existing frameworks, which was undertaken to explore the degree of similarity and compliance between the concepts, and to extend their capabilities. DCS and MARTe operate in parallel with synchronised state machines and a common message logger. Configuration data is exchanged before the real-time phase. During the real-time phase, structured data is exchanged via shared memory and an existing DCS algorithm is replicated within MARTe. The coupling tests the flexibility and identifies the respective strengths of the two frameworks, providing a well-informed basis on which to move forward and design a new ITER real-time framework

Calculating Characteristics of the Screws with Constant And Variable Step

Directory of Open Access Journals (Sweden)

B. N. Zotov

2015-01-01

Full Text Available This work is devoted to creating a technique for calculating power characteristics of the screws with constant and variable step for the centrifugal pumps. The technique feature is that the reverse currents, which are observed in screws working at low flow, are numerically taken into account. The paper presents a diagram of the stream in the screw with flow to the network Q=0, and the static pressure of the screw in this mode is computed according to reverse current parameters. Maximum flow of screw is determined from the known formulas. When calculating the power characteristics and computing the overall efficiency of the screw, for the first time a volumetric efficiency of the screw is introduced. It is defined as a ratio between the flow into the network and the sum of the reverse current flows and a flow into the network. This approach allowed us to determine the efficiency of the screw over the entire range of flows.A comparison of experimental characteristics of the constant step screw with those of calculated by the proposed technique shows their good agreement.The technique is also used in calculating characteristics of the variable step screws. The variable step screw is considered as a screw consisting of two screws with a smooth transition of the blades from the inlet to the outlet. Screws in which the step at the inlet is less than that of at the outlet as well as screws with the step at the inlet being more than that of at the outlet were investigated. It is shown that a pressure of the screw with zero step and the value of the reverse currents depend only on the parameters of the input section of the screw, and the maximum flow, if the step at the inlet is more than the step at the outlet, is determined by the parameters of the output part of the screw. Otherwise, the maximum flow is determined a little bit differently.The paper compares experimental characteristics with characteristics calculated by the technique for variable step

Modulation of selective attention by polarity-specific tDCS effects.

Science.gov (United States)

Pecchinenda, Anna; Ferlazzo, Fabio; Lavidor, Michal

2015-02-01

Selective attention relies on working memory to maintain an attention set of task priorities. Consequently, selective attention is more efficient when working memory resources are not depleted. However, there is some evidence that distractors are processed even when working memory load is low. We used tDCS to assess whether boosting the activity of the Dorsolateral Prefrontal Cortex (DLPFC), involved in selective attention and working memory, would reduce interference from emotional distractors. Findings showed that anodal tDCS over the DLPFC was not sufficient to reduce interference from angry distractors. In contrast, cathodal tDCS over the DLPFC reduced interference from happy distractors. These findings show that altering the DLPFC activity is not sufficient to establish top-down control and increase selective attention efficiency. Although, when the neural signal in the DLPFC is altered by cathodal tDCS, interference from emotional distractors is reduced, leading to an improved performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Using Transcranial Direct Current Stimulation (tDCS to study and treat aphasia

Directory of Open Access Journals (Sweden)

Nazbanou Nozari

2014-04-01

- What are the challenges of using tDCS for hypothesis testing and how can I reduce the risk of misinterpreting my results? In summary, the symposium is designed to (a promote the theoretical understanding of the basic science of tDCS, and (b to tackle several pragmatic issues when designing tDCS studies, with the ultimate goal of cultivating higher standards for using a potentially invaluable technique for both clinical and research purposes. Given the growing interest in the aphasia community for using tDCS and the sophistication of the audience, we believe that the Academy’s annual meeting is the ideal venue for this symposium.

Study on operation I and C DCS test method of EPR project

International Nuclear Information System (INIS)

Meng Ying; Lv Zhihong; Huang Xinnian; Fan Haiying; Li Zhuojia; Xiao Shushu

2014-01-01

Through summarization and optimization of the method for operation I and C DCS test of the European pressurized reactor project, the conclusions play a guiding role on the operation I and C DCS test of the domestic advanced nuclear power plant. The study of the method focuses on the test platform, the test process and the optimization of method of operation I and C DCS test with the practical experience. The reasonable and reliable test method for operation I and C DCS test of the European pressurized reactor project is worthy of the reference and the development in the project of the domestic advanced nuclear power plant. (authors)

CHANGE IN CONDYLAR POSITION AND SKELETAL STABILITY ASSESSMENT FOLLOWING BSSO FOR MANDIBULAR SET BACK

Directory of Open Access Journals (Sweden)

Manjunath

2015-09-01

Full Text Available Change in condylar position following mandibular bilateral sagittal split osteotomy (BSSO has been implicated as an important factor in the appearance of immediate postoperative relapse during rigid fixation. It has been suggested that the control of the condylar segment following BSSO is the most important aspect in preventing relapse. The study was done to evaluate changes in position of condyle taken with lateral and frontal cephalograms with 20 patients were assessed, 10 male and 10 female patients wer e divided as group 1 and group 2. Patients undergoing sagittal split ramus osteotomy for mandibular set back were selected; radiographs before operation/surgery, immediately after surgery, 3 months and 6 months post - surgery. Differences between groups were measured by PAIRED ‘T’ TEST a nd time dependent changes in cephalometric measurements were examined by FISCHERS TEST. The present study results conclude significant difference occurring in both proximal and distal segment including condyle. Occlusal stabil ity and skeletal stability also maintained post operatively

A Novel Pedicle Screw with Mobile Connection: A Pilot Study

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Yasuaki Tokuhashi

2014-01-01

Full Text Available To prevent adjacent disc problems after spinal fusion, a pedicle screw with a mobile junction between the head and threaded shaft was newly developed. The threaded shaft of the screw has 10 degrees mobility in all directions, but its structure is to prevent abnormal translation and tilting. This screw was evaluated as follows: (1 endurance test: 106 times rotational stress was applied; (2 biological reactions: novel screws with a mobile head and conventional screws with a fixed head were inserted into the bilateral pedicles of the L3, L4, and L5 in two mini pigs with combination. Eight months after surgery, vertebral units with the screw rod constructs were collected. After CT scan, the soft and bony tissues around the screws were examined grossly and histologically. As a result, none of the screws broke during the endurance test stressing. The mean amount of abrasion wear was 0.0338 g. In the resected mini pig section, though zygapophyseal joints between fixed-head screws showed bony union, the amount of callus in the zygapophyseal joints connected with mobile-head screws was small, and joint space was confirmed by CT. No metalloses were noted around any of the screws. Novel screws were suggested to be highly durable and histologically safe.

Minimally Invasive Technique for PMMA Augmentation of Fenestrated Screws

Directory of Open Access Journals (Sweden)

Jan-Helge Klingler

2015-01-01

Full Text Available Purpose. To describe the minimally invasive technique for cement augmentation of cannulated and fenestrated screws using an injection cannula as well as to report its safety and efficacy. Methods. A total of 157 cannulated and fenestrated pedicle screws had been cement-augmented during minimally invasive posterior screw-rod spondylodesis in 35 patients from January to December 2012. Retrospective evaluation of cement extravasation and screw loosening was carried out in postoperative plain radiographs and thin-sliced triplanar computed tomography scans. Results. Twenty-seven, largely prevertebral cement extravasations were detected in 157 screws (17.2%. None of the cement extravasations was causing a clinical sequela like a new neurological deficit. One screw loosening was noted (0.6% after a mean follow-up of 12.8 months. We observed no cementation-associated complication like pulmonary embolism or hemodynamic insufficiency. Conclusions. The presented minimally invasive cement augmentation technique using an injection cannula facilitates convenient and safe cement delivery through polyaxial cannulated and fenestrated screws during minimally invasive screw-rod spondylodesis. Nevertheless, the optimal injection technique and design of fenestrated screws have yet to be identified. This trial is registered with German Clinical Trials DRKS00006726.

Insertion profiles of 4 headless compression screws.

Science.gov (United States)

Hart, Adam; Harvey, Edward J; Lefebvre, Louis-Philippe; Barthelat, Francois; Rabiei, Reza; Martineau, Paul A

2013-09-01

In practice, the surgeon must rely on screw position (insertion depth) and tactile feedback from the screwdriver (insertion torque) to gauge compression. In this study, we identified the relationship between interfragmentary compression and these 2 factors. The Acutrak Standard, Acutrak Mini, Synthes 3.0, and Herbert-Whipple implants were tested using a polyurethane foam scaphoid model. A specialized testing jig simultaneously measured compression force, insertion torque, and insertion depth at half-screw-turn intervals until failure occurred. The peak compression occurs at an insertion depth of -3.1 mm, -2.8 mm, 0.9 mm, and 1.5 mm for the Acutrak Mini, Acutrak Standard, Herbert-Whipple, and Synthes screws respectively (insertion depth is positive when the screw is proud above the bone and negative when buried). The compression and insertion torque at a depth of -2 mm were found to be 113 ± 18 N and 0.348 ± 0.052 Nm for the Acutrak Standard, 104 ± 15 N and 0.175 ± 0.008 Nm for the Acutrak Mini, 78 ± 9 N and 0.245 ± 0.006 Nm for the Herbert-Whipple, and 67 ± 2N, 0.233 ± 0.010 Nm for the Synthes headless compression screws. All 4 screws generated a sizable amount of compression (> 60 N) over a wide range of insertion depths. The compression at the commonly recommended insertion depth of -2 mm was not significantly different between screws; thus, implant selection should not be based on compression profile alone. Conically shaped screws (Acutrak) generated their peak compression when they were fully buried in the foam whereas the shanked screws (Synthes and Herbert-Whipple) reached peak compression before they were fully inserted. Because insertion torque correlated poorly with compression, surgeons should avoid using tactile judgment of torque as a proxy for compression. Knowledge of the insertion profile may improve our understanding of the implants, provide a better basis for comparing screws, and enable the surgeon to optimize compression. Copyright �

Ball Screw Actuator Including a Stop with an Integral Guide

Science.gov (United States)

Wingett, Paul T. (Inventor); Perek, John (Inventor); Geck, Kellan (Inventor)

2015-01-01

An actuator includes a housing assembly, a ball nut, a ball screw, and a ball screw stop. The ball nut is rotationally mounted in the housing assembly, is adapted to receive an input torque, and is configured, upon receipt thereof, to rotate and supply a drive force. The ball screw is mounted within the housing assembly and extends through the ball nut. The ball screw has a first end and a second end, and is coupled to receive the drive force from the ball nut. The ball screw is configured, upon receipt of the drive force, to selectively translate between a stow position and a deploy position. The ball screw stop is mounted on the ball screw to translate therewith and is configured to at selectively engage the housing assembly while the ball screw is translating, and engage the ball nut when the ball screw is in the deploy position.

Transcranial Direct Current Stimulation (tDCS) Enhances the Excitability of Trigemino-Facial Reflex Circuits.

Science.gov (United States)

Cabib, Christopher; Cipullo, Federica; Morales, Merche; Valls-Solé, Josep

2016-01-01

Transcranial direct current stimulation (tDCS) causes a tiny burning sensation through activation of local cutaneous trigeminal afferents. Trigeminal sensory inputs from tDCS may generate excitability changes in the trigemino-facial reflex circuits. Sixteen healthy volunteers were submitted to 20 minutes tDCS sessions with two types of electrode-montage conditions: 1. Real vs Sham 'bi-hemispheric' tDCS (cathode/anode: C4/C3), for blinded assessment of effects, and 2. 'uni-hemispheric' tDCS (cathode/anode: Fp3/C3), for assessment of laterality of the effects. Supraorbital nerve stimuli were used to obtain blink reflexes before, during (10 minutes from onset) and after (30 minutes from onset) the tDCS session. Outcome measures were R2 habituation (R2H) to repeated stimuli, the blink reflex excitability recovery (BRER) to paired stimuli and the blink reflex inhibition by a prepulse (BRIP). Real but not sham bi-hemispheric tDCS caused a significant decrease of R2H and leftward shift of BRER curve (p tDCS on BRER and BRIP were larger on ipsilateral than on contralateral blink reflexes (p tDCS enhances the excitability of trigemino-facial reflex circuits. The finding of larger ipsilateral than contralateral effects suggests that sensitization through cutaneous trigeminal afferents adds on other possible mechanisms such as activation of cortico-nuclear or cortico-reticular connections. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of different language and tDCS interventions in PPA and their neural correlates

Directory of Open Access Journals (Sweden)

Kyrana Tsapkini

2015-05-01

Results: First, we replicated our previous results obtained with fewer participants: all improved in both tDCS and sham conditions on trained items. Generalization of treatment on untrained items was significant only in tDCS condition. Therapy gains lasted longer in tDCS condition as well. Second, preliminary analyses of rs-fMRI show changes of functional connectivity between written language areas in the tDCS and sham conditions. Conclusions: tDCS represents an increasingly valuable treatment option in language rehabilitation even in neurodegeneration. Late intervention is as beneficial as early intervention but improvement seems more dramatic in early cases. Different possibilities are discussed: tDCS may indeed change the course of the disease, i.e., it may slow down the rate of decline or, language improvement due to tDCS (or delay in language deterioration due to the course of the disease may hold the spread of decline in other cognitive functions, thus, early interventions appear more beneficial. The correlation between functional connectivity and language production outcomes is expected to shed light on how tDCS works in the brains of people with a neurodegenerative disease. Implications of functional connectivity changes between language areas involved in the targeted language function will inform further interventions.

Frontoparietal tDCS Benefits Visual Working Memory in Older Adults With Low Working Memory Capacity.

Science.gov (United States)

Arciniega, Hector; Gözenman, Filiz; Jones, Kevin T; Stephens, Jaclyn A; Berryhill, Marian E

2018-01-01

Working memory (WM) permits maintenance of information over brief delays and is an essential executive function. Unfortunately, WM is subject to age-related decline. Some evidence supports the use of transcranial direct current stimulation (tDCS) to improve visual WM. A gap in knowledge is an understanding of the mechanism characterizing these tDCS linked effects. To address this gap, we compared the effects of two tDCS montages designed on visual working memory (VWM) performance. The bifrontal montage was designed to stimulate the heightened bilateral frontal activity observed in aging adults. The unilateral frontoparietal montage was designed to stimulate activation patterns observed in young adults. Participants completed three sessions (bilateral frontal, right frontoparietal, sham) of anodal tDCS (20 min, 2 mA). During stimulation, participants performed a visual long-term memory (LTM) control task and a visual WM task. There was no effect of tDCS on the LTM task. Participants receiving right unilateral tDCS showed a WM benefit. This pattern was most robust in older adults with low WM capacity. To address the concern that the key difference between the two tDCS montages could be tDCS over the posterior parietal cortex (PPC), we included new analyses from a previous study applying tDCS targeting the PPC paired with a recognition VWM task. No significant main effects were found. A subsequent experiment in young adults found no significant effect of either tDCS montage on either task. These data indicate that tDCS montage, age and WM capacity should be considered when designing tDCS protocols. We interpret these findings as suggestive that protocols designed to restore more youthful patterns of brain activity are superior to those that compensate for age-related changes.

Changes in mineralised tissue at the site of origin of condylar fracture are present before athletic training in Thoroughbred horses.

Science.gov (United States)

Firth, E C; Doube, M; Boyde, A

2009-10-01

To show that changes are present at the site of origin of metacarpal condylar fracture in young Thoroughbred horses before they enter race training. Bone slices, 2 mm thick, in three mediolateral planes through the centre of rotation of the metacarpo-phalangeal joint (MCPJ) of both distal third metacarpal bones (Mc3) of 12 Thoroughbred horses aged 17 months, were imaged using point-projection digital X-ray imaging (muXR). In some horses, linear or ovoid radiolucency was found in articular calcified cartilage (ACC) and subchondral bone of the palmaro-distal aspect of the sagittal groove, exactly at the site of more advanced stages of condylar fatigue fracture. An incidental finding was ovoid radiolucency in the apex of the dorso-distal aspect of the sagittal ridge, with or without fragmentation or disturbance of the subchondral mineralised tissue line, resembling equine osteochondrosis. The findings imply that the aetiology of condylar fatigue fracture in young Thoroughbred horses includes abnormality in development of the bone and joint that is present before athletic activity occurs.

Ball Screw Actuator Including an Axial Soft Stop

Science.gov (United States)

Wingett, Paul T. (Inventor); Forrest, Steven Talbert (Inventor); Abel, Steve (Inventor); Woessner, George (Inventor); Hanlon, Casey (Inventor)

2016-01-01

An actuator includes an actuator housing, a ball screw, and an axial soft stop assembly. The ball screw extends through the actuator housing and has a first end and a second end. The ball screw is coupled to receive a drive force and is configured, upon receipt of the drive force, to selectively move in a retract direction and an extend direction. The axial soft stop assembly is disposed within the actuator housing. The axial soft stop assembly is configured to be selectively engaged by the ball screw and, upon being engaged thereby, to translate, with compliance, a predetermined distance in the extend direction, and to prevent further movement of the ball screw upon translating the predetermined distance.

Condylectomy and "surgery first" approach: An expedited treatment for condylar hyperplasia in a patient with facial asymmetry.

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López, Diego Fernando; Aristizábal, Juan Fernando; Martínez-Smit, Rosana

2017-01-01

Condylar Hyperplasia (CH) is a self-limiting pathology condition that produces severe facial deformity at the expense of mandibular asymmetry. In this case report a 15-year-old female patient was diagnosed with Unilateral Condylar Hiperplasia (UCH) by mean of single-photon emission computed tomography (SPECT) and histological study. A high condylectomy in the right condyle was performed to stop the active status of the hyperplasia. A month after condylectomy, orthognathic jaw impaction and asymmetric mandibular setback surgery was performed with the Surgery First Approach (SFA). After 10 days, orthodontic appointments were made every two weeks during 4 months. The active phase of treatment lasted 14 months. Excellent facial and occlusal outcomes were obtained and after 24 months in retention the results remained stable.

Correction of rabbit model with mandibular ramus shortening by distraction osteogenesis at condylar neck.

Science.gov (United States)

Meng, Qinggong; Yang, Xuewen; Long, Xing; Li, Jian; Cai, Hengxing

2012-04-01

The rabbit model has been established to mimic the effect of temporomandibular joint (TMJ) arthroplasty of ankylosis, and distraction at the level of the condylar neck is used to elongate the ascending ramus. The histomorphologic changes of TMJ and distraction gap were investigated. The unilateral condyles and articular discs were extirpated, and the experimental mandibular rami were shortened by 5 mm. An embedded distracter was used to restore the height of the mandibular ramus by unilateral condylar neck distraction (0.8 mm daily for 7 days). A total of 12 adult white rabbits were used, 8 in the experimental group and 4 in the control group. Of the 8 rabbits in the experimental group, 4 each were killed at 4 and 8 weeks after completion of distraction. The TMJ and distracted calluses were harvested and processed for radiographic and histologic examination. An open bite was seen in all rabbits postoperatively that had diminished at the end of distraction. The newly formed condyles radiologically showed remodeling, flattening, and sclerosis. The bony transport disc had gradually remodeled to a new condyle that was similar to the original condyle in appearance and structure. The surface of the transport disc was covered with a fibrous tissue. Moreover, the bony regeneration was perfect in the distraction gap. These results suggest that distraction osteogenesis at the condylar neck using the traditional preauricular approach of TMJ surgery, without the additional incision, can be performed concurrently with arthroplasty of TMJ ankylosis at the same region. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Effects of tDCS on Bimanual Motor Skills: A Brief Review.

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Pixa, Nils H; Pollok, Bettina

2018-01-01

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that allows the modulation of cortical excitability as well as neuroplastic reorganization using a weak constant current applied through the skull on the cerebral cortex. TDCS has been found to improve motor performance in general and motor learning in particular. However, these effects have been reported almost exclusively for unimanual motor tasks such as serial reaction time tasks, adaptation tasks, or visuo-motor tracking. Despite the importance of bimanual actions in most activities of daily living, only few studies have investigated the effects of tDCS on bimanual motor skills. The objectives of this review article are: (i) to provide a concise overview of the few existing studies in this area; and (ii) to discuss the effects of tDCS on bimanual motor skills in healthy volunteers and patients suffering from neurological diseases. Despite considerable variations in stimulation protocols, the bimanual tasks employed, and study designs, the data suggest that tDCS has the potential to enhance bimanual motor skills. The findings imply that the effects of tDCS vary with task demands, such as complexity and the level of expertise of the participating volunteers. Nevertheless, optimized stimulation protocols tailored to bimanual tasks and individual performance considering the underlying neural substrates of task execution are required in order to probe the effectiveness of tDCS in greater detail, thus creating an opportunity to support motor recovery in neuro-rehabilitation.

Spatial and polarity precision of concentric high-definition transcranial direct current stimulation (HD-tDCS)

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Alam, Mahtab; Truong, Dennis Q.; Khadka, Niranjan; Bikson, Marom

2016-06-01

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that applies low amplitude current via electrodes placed on the scalp. Rather than directly eliciting a neuronal response, tDCS is believed to modulate excitability—enhancing or suppressing neuronal activity in regions of the brain depending on the polarity of stimulation. The specificity of tDCS to any therapeutic application derives in part from how electrode configuration determines the brain regions that are stimulated. Conventional tDCS uses two relatively large pads (>25 cm2) whereas high-definition tDCS (HD-tDCS) uses arrays of smaller electrodes to enhance brain targeting. The 4  ×  1 concentric ring HD-tDCS (one center electrode surrounded by four returns) has been explored in application where focal targeting of cortex is desired. Here, we considered optimization of concentric ring HD-tDCS for targeting: the role of electrodes in the ring and the ring’s diameter. Finite element models predicted cortical electric field generated during tDCS. High resolution MRIs were segmented into seven tissue/material masks of varying conductivities. Computer aided design (CAD) model of electrodes, gel, and sponge pads were incorporated into the segmentation. Volume meshes were generated and the Laplace equation (\

A Biomechanical Analysis of 2 Constructs for Metacarpal Spiral Fracture Fixation in a Cadaver Model: 2 Large Screws Versus 3 Small Screws.

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Eu-Jin Cheah, Andre; Behn, Anthony W; Comer, Garet; Yao, Jeffrey

2017-12-01

Surgeons confronted with a long spiral metacarpal fracture may choose to fix it solely with lagged screws. A biomechanical analysis of a metacarpal spiral fracture model was performed to determine whether 3 1.5-mm screws or 2 2.0-mm screws provided more stability during bending and torsional loading. Second and third metacarpals were harvested from 12 matched pairs of fresh-frozen cadaveric hands and spiral fractures were created. One specimen from each matched pair was fixed with 2 2.0-mm lagged screws whereas the other was fixed with 3 1.5-mm lagged screws. Nine pairs underwent combined cyclic cantilever bending and axial compressive loading followed by loading to failure. Nine additional pairs were subjected to cyclic external rotation while under a constant axial compressive load and were subsequently externally rotated to failure under a constant axial compressive load. Paired t tests were used to compare cyclic creep, stiffness, displacement, rotation, and peak load levels. Average failure torque for all specimens was 7.2 ± 1.7 Nm. In cyclic torsional testing, the group with 2 screws exhibited significantly less rotational creep than the one with 3 screws. A single specimen in the group with 2 screws failed before cyclic bending tests were completed. No other significant differences were found between test groups during torsional or bending tests. Both constructs were biomechanically similar except that the construct with 2 screws displayed significantly less loosening during torsional cyclic loading, although the difference was small and may not be clinically meaningful. Because we found no obvious biomechanical advantage to using 3 1.5-mm lagged screws to fix long spiral metacarpal fractures, the time efficiency and decreased implant costs of using 2-2.0 mm lagged screws may be preferred. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Transoral open reduction and fixation of mandibular condylar base and neck fractures in children and young teenagers--a beneficial treatment option?

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Schiel, Sebastian; Mayer, Peter; Probst, Florian; Otto, Sven; Cornelius, Carl-Peter

2013-07-01

To evaluate the possible benefits of open surgery, endoscopically assisted reduction and fixation using a transoral route was used in a selected series of pediatric patients with displaced condylar base and neck fractures. A cohort of 6 patients (1 male and 5 female; age range, 7 to 15 yr; mean, 13.4 yr) with displaced condylar base and neck fractures (n = 9) were included. Inclusion criteria were age younger than 16 years, fracture of the condylar base or neck, and displacement of the fracture by at least 45°. Fractures were classified using conventional radiography, cone-beam computed tomography, or computed tomography. Patients underwent transoral endoscopically assisted open reduction and fixation using miniplate osteosynthesis. Postoperatively, patients were followed clinically and radiographically for 18 months. Complete follow-up varied from 18 to 35 months (median, 24.5 months). All patients showed normal occlusion and pain-free unrestricted function of the temporomandibular joint at 3, 6, 12, and 18 months postoperatively. There were no signs of incomplete remodeling or deformation of the condyles. Transoral endoscopically assisted surgical treatment of severely displaced condylar base and neck fractures in children and young teenagers offers a reliable solution to preclude the sequelae of closed treatment, such as altered morphology and functional disturbances, eliminates visible scars, and lowers the risk of facial nerve damage compared with open reduction using an extraoral approach. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Conservative approach of condylar fracture in a child by the use of rubber elastics: 7-year follow-up.

Science.gov (United States)

Noleto, José Wilson; Leão, Ellen Inácio; Braga, Cícero Luis; Yang, Sérgio; Sardow, Aline

2011-01-01

Condylar fractures in pediatric patients occur frequently, often with minimal pain and discomfort. Thus, these fractures in children are overlooked during emergency care. Condylar fractures can be treated conservatively or by open reduction. As a rule, very good healing results are achieved by conservative treatment. In these cases, jaw function restoration using physiotherapy at an early stage can prevent complications such as asymmetry, interference in the facial growth, and ankylosis. The purpose of this case report was to discuss the peculiarities of treatment of mandibular condyle fractures in pediatric patients and report a case in which the condyles were successfully treated conservatively in a 10-year-old patient. The case was followed up for seven years.

Hydraulic screw fastening devices - design, maintenance, operational experience

International Nuclear Information System (INIS)

Lachner.

1976-01-01

With hydraulic screw fastening devices, pretension values with a maximum deviation of +-2.5% from the rated value can be achieved. This high degree of pretension accuracy is of considerable importance with regard to the safety factor required for the screw connection between reactor vessel head and reactor vessel. The operating rhythm of a nuclear power station with its refuelling art regular intervals makes further demands on the screw fastening device, in particular in connection with the transport of screws and for nuts. The necessary installations extend the screw fastening device into a combination of a high-pressure hydraulic cylinder system with an electrical or pneumoelectrical driving unit and an electrical control unit. Maintenance work is complicated by the large number of identical, highly stressed structural elements in connection with an unfavourable relation operating time/outage time. The problems have been perpetually reduced by close cooperation between the manufacturers and users of screw fastening devices. (orig./AK) [de

Stress corrosion cracking lifetime prediction of spring screw

International Nuclear Information System (INIS)

Koh, S. K.; Ryu, C. H.

2004-01-01

A lifetime prediction of holddown spring screw in nuclear fuel assembly was performed using fracture mechanics approach. The spring screw was designed such that it was capable of sustaining the loads imposed by the initial tensile preload and operational loads. In order to investigate the cause of failure and to predict the stress corrosion cracking life of the screw, a stress analysis of the top nozzle spring assembly was done using finite element analysis. The elastic-plastic finite element analysis showed that the local stresses at the critical regions of head-shank fillet and thread root significantly exceeded than the yield strength of the screw material, resulting in local plastic deformation. Normalized stress intensity factors for PWSCC life prediction was proposed. Primary water stress corrosion cracking life of the Inconel 600 screw was predicted by using integration of the Scott model and resulted in 1.78 years, which was fairly close to the actual service life of the holddown spring screw

Magnesium Alloys as a Biomaterial for Degradable Craniofacial Screws

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Henderson, Sarah E.; Verdelis, Konstantinos; Maiti, Spandan; Pal, Siladitya; Chung, William L.; Chou, Da-Tren; Kumta, Prashant N.; Almarza, Alejandro J.

2014-01-01

Recently, magnesium (Mg) alloys have received significant attention as a potential biomaterial for degradable implants, and this study was directed at evaluating the suitability of Mg for craniofacial bone screws. The objective was to implant screws fabricated from commercially available Mg-alloys (pure Mg and AZ31) in-vivo in a rabbit mandible. First, Mg-alloy screws were compared to stainless steel screws in an in-vitro pull-out test and determined to have a similar holding strength (~40N). A finite element model of the screw was created using the pull-out test data, and the model can be used for future Mg-alloy screw design. Then, Mg-alloy screws were implanted for 4, 8, and 12 weeks, with two controls of an osteotomy site (hole) with no implant and a stainless steel screw implanted for 12 weeks. MicroCT (computed tomography) was used to assess bone remodeling and Mg-alloy degradation, both visually and qualitatively through volume fraction measurements for all time points. Histologic analysis was also completed for the Mg-alloys at 12 weeks. The results showed that craniofacial bone remodeling occurred around both Mg-alloy screw types. Pure Mg had a different degradation profile than AZ31, however bone growth occurred around both screw types. The degradation rate of both Mg-alloy screw types in the bone marrow space and the muscle were faster than in the cortical bone space at 12 weeks. Furthermore, it was shown that by alloying Mg, the degradation profile could be changed. These results indicate the promise of using Mg-alloys for craniofacial applications. PMID:24384125

Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance.

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Molero-Chamizo, Andrés; Alameda Bailén, José R; Garrido Béjar, Tamara; García López, Macarena; Jaén Rodríguez, Inmaculada; Gutiérrez Lérida, Carolina; Pérez Panal, Silvia; González Ángel, Gloria; Lemus Corchero, Laura; Ruiz Vega, María J; Nitsche, Michael A; Rivera-Urbina, Guadalupe N

2018-02-01

Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS-namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

Tightening techniques for the retaining screws of universal abutment

Directory of Open Access Journals (Sweden)

Alexandre Wittcinski REGALIN

Full Text Available Abstract Purpose This study evaluated the torque maintenance of universal abutment retaining screws using different tightening techniques, and coated or uncoated screws. Material and method The screws were tightened to implants as following: Control – 32 Ncm torque; H20 – holding 32 Ncm torque for 20 s; R – 32 Ncm torque, repeated after 10 min (retorque; and H20+R – combining the two tightening techniques. Titanium and coated screws were also evaluated. Result Statistical analysis showed higher maintained torque for titanium screws (p<0.001. The H20+R technique showed the highest maintained torque (p=0.003, but the H20 technique’s maintained torque was similar. Conclusion Titanium screws associating the two tightening techniques can improve maintained torque.

Evaluation of posterior lateral femoral condylar hypoplasia using axial MRI images in patients with complete discoid meniscus.

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Xu, Zhihong; Chen, Dongyang; Shi, Dongquan; Dai, Jin; Yao, Yao; Jiang, Qing

2016-03-01

Hypoplasia of the lateral femoral condyle has been reported in discoid lateral meniscus patients, but associated imaging findings in the axial plane have not been characterized. In this study, we aimed to identify differences in the lateral femoral condyle between patients with discoid lateral meniscus and those with normal menisci using axial MRI images. Twenty-three patients (24 knees) with complete discoid lateral meniscus, 43 (45 knees) with incomplete discoid lateral meniscus, and 50 with normal menisci (50 knees) were enrolled and distributed into three groups. Two new angles, posterior lateral condylar angle (PLCA) and posterior medial condylar angle (PMCA), were measured on axial MRI images; the posterior condylar angle (PCA) was also measured. Differences between the three groups in the PLCA, PMCA, PCA, and PLCA/PMCA were analysed. The predictive value of PLCA and PLCA/PMCA for complete discoid lateral meniscus was assessed. In the complete discoid lateral meniscus group, PLCA and PLCA/PMCA were significantly smaller compared with the normal meniscus group and the incomplete discoid lateral meniscus group (P meniscus group compared with the incomplete discoid lateral meniscus group (P meniscus group (P meniscus. Hypoplasia of the posterior lateral femoral condyle is typically seen in patients with complete discoid lateral meniscus. PLCA and PLCA/PMCA can be measured from axial MRI images and used as excellent predictive parameters for complete discoid lateral meniscus. Diagnostic study, Level III.

The Integration of DCS I/O to an Existing PLC

Science.gov (United States)

Sadhukhan, Debashis; Mihevic, John

2013-01-01

At the NASA Glenn Research Center (GRC), Existing Programmable Logic Controller (PLC) I/O was replaced with Distributed Control System (DCS) I/O, while keeping the existing PLC sequence Logic. The reason for integration of the PLC logic and DCS I/O, along with the evaluation of the resulting system is the subject of this paper. The pros and cons of the old system and new upgrade are described, including operator workstation screen update times. Detail of the physical layout and the communication between the PLC, the DCS I/O and the operator workstations are illustrated. The complex characteristics of a central process control system and the plan to remove the PLC processors in future upgrades is also discussed.

Translating tDCS into the field of obesity: mechanism-driven approaches

Directory of Open Access Journals (Sweden)

Miguel eAlonso-Alonso

2013-08-01

Full Text Available Transcranial direct current stimulation (tDCS is emerging as a promising technique for neuromodulation in a variety of clinical conditions. Recent neuroimaging studies suggest that modifying the activity of brain circuits involved in eating behavior could provide therapeutic benefits in obesity. One session of tDCS over the dorsolateral prefrontal cortex can induce an acute decrease in food craving, according to three small clinical trials, but the extension of these findings into the field of obesity remains unexplored. Importantly, there has been little/no interaction of our current understanding of tDCS and its mechanisms with obesity-related research. How can we start closing this gap and rationally guide the translation of tDCS into the field of obesity? In this mini-review I summarize some of the challenges and questions ahead, related to basic science and technical aspects, and suggest future directions.

Do screws and screw holes affect osteolysis in cementless cups using highly crosslinked polyethylene? A 7 to 10-year follow-up case-control study.

Science.gov (United States)

Taniguchi, N; Jinno, T; Takada, R; Koga, D; Ando, T; Okawa, A; Haro, H

2018-05-01

The use of screws and the presence of screw holes may cause acetabular osteolysis and implant loosening in cementless total hip arthroplasty (THA) using conventional polyethylene. In contrast, this issue is not fully understood using highly crosslinked polyethylene (HXLPE), particularly in large comparative study. Therefore, we performed a case-control study to assess the influence of screw usage and screw holes on: (1) implant fixation and osteolysis and (2) polyethylene steady-state wear rate, using cases with HXLPE liners followed up for 7-10 years postoperatively. The screw usage and screw holes adversely affect the implant fixation and incidence of wear-related osteolysis in THA with HXLPE. We reviewed 209 primary cementless THAs performed with 26-mm cobalt-chromium heads on HXLPE liners. To compare the effects of the use of screws and the presence of screw holes, the following groups were established: (1) with-screw (n=140); (2) without-screw (n=69); (3) no-hole (n=27) and (4) group in which a cup with screw holes, but no screw was used (n=42). Two adjunct groups (no-hole cups excluded) were established to compare the differences in the two types of HXLPE: (5) remelted group (n=100) and (6) annealed group (n=82). Implant stability and osteolysis were evaluated by plain radiography and computed tomography. The wear rate from 1 year to the final evaluation was measured using plain X-rays and PolyWare Digital software. All cups and stems achieved bony fixation. On CT-scan, no acetabular osteolysis was found, but there were 3 cases with a small area of femoral osteolysis. The mean steady-state wear rate of each group was (1) 0.031±0.022, (2) 0.033±0.035, (3) 0.031±0.024, (4) 0.029±0.018, (5) 0.030±0.018 and (6) 0.034±0.023mm/year, respectively. A comparison of the effects of screw usage or screw holes found no significant between-group differences in the implant stability, prevalence of osteolysis [no acetabular osteolysis and 3/209 at femoral side (1

A geometrical introduction to screw theory

International Nuclear Information System (INIS)

Minguzzi, E

2013-01-01

This work introduces screw theory, a venerable but little known theory aimed at describing rigid body dynamics. This formulation of mechanics unifies in the concept of screw the translational and rotational degrees of freedom of the body. It captures a remarkable mathematical analogy between mechanical momenta and linear velocities, and between forces and angular velocities. For instance, it clarifies that angular velocities should be treated as applied vectors and that, under the composition of motions, they sum with the same rules of applied forces. This work provides a short and rigorous introduction to screw theory intended for an undergraduate and general readership. (paper)

Twin screw wet granulation: Binder delivery.

Science.gov (United States)

Saleh, Mohammed F; Dhenge, Ranjit M; Cartwright, James J; Hounslow, Michael J; Salman, Agba D

2015-06-20

The effects of three ways of binder delivery into the twin screw granulator (TSG) on the residence time, torque, properties of granules (size, shape, strength) and binder distribution were studied. The binder distribution was visualised through the transparent barrel using high speed imaging as well as quantified using offline technique. Furthermore, the effect of binder delivery and the change of screw configuration (conveying elements only and conveying elements with kneading elements) on the surface velocity of granules across the screw channel were investigated using particle image velocimetry (PIV). The binder was delivered in three ways; all solid binder incorporated with powder mixture, 50% of solid binder mixed with powder mixture and 50% mixed with water, all the solid binder dissolved in water. Incorporation of all solid binder with powder mixture resulted in the relatively longer residence time and higher torque, narrower granule size distribution, more spherical granules, weaker big-sized granules, stronger small-sized granules and better binder distribution compared to that in other two ways. The surface velocity of granules showed variation from one screw to another as a result of uneven liquid distribution as well as shown a reduction while introducing the kneading elements into the screw configuration. Copyright © 2015. Published by Elsevier B.V.

Functional connectivity substrates for tDCS response in Minimally Conscious State patients

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Carlo Cavaliere

2016-11-01

Full Text Available Transcranial direct current stimulation (tDCS is a non-invasive technique recently employed in disorders of consciousness, and determining a transitory recovery of signs of consciousness in almost half of minimally conscious state (MCS patients. Although the rising evidences about its possible role in the treatment of many neurological and psychiatric conditions, no evidences exist about brain functional connectivity substrates underlying tDCS response. We retrospectively evaluated resting state functional Magnetic Resonance Imaging (fMRI of 16 sub-acute and chronic MCS patients (6 tDCS responders who successively received a single left dorsolateral prefrontal cortex (DLPFC tDCS in a double-blind randomized cross-over trial. A seed-based approach for regions of left extrinsic control network and default-mode network was performed.TDCS responders showed an increased left intra-network connectivity for regions co-activated with left DLPFC, and significantly with left inferior frontal gyrus. Non-responders MCS patients showed an increased connectivity between left DLPFC and midline cortical structures, including anterior cingulate cortex and precuneus.Our findings suggest that a prior high connectivity with regions belonging to extrinsic control network can facilitate transitory recovery of consciousness in a subgroup of MCS patients that underwent tDCS treatment. Therefore, resting state-fMRI could be very valuable in detecting the neuronal conditions necessary for tDCS to improve behavior in MCS.

Using transcranial direct-current stimulation (tDCS) to understand cognitive processing.

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Reinhart, Robert M G; Cosman, Josh D; Fukuda, Keisuke; Woodman, Geoffrey F

2017-01-01

Noninvasive brain stimulation methods are becoming increasingly common tools in the kit of the cognitive scientist. In particular, transcranial direct-current stimulation (tDCS) is showing great promise as a tool to causally manipulate the brain and understand how information is processed. The popularity of this method of brain stimulation is based on the fact that it is safe, inexpensive, its effects are long lasting, and you can increase the likelihood that neurons will fire near one electrode and decrease the likelihood that neurons will fire near another. However, this method of manipulating the brain to draw causal inferences is not without complication. Because tDCS methods continue to be refined and are not yet standardized, there are reports in the literature that show some striking inconsistencies. Primary among the complications of the technique is that the tDCS method uses two or more electrodes to pass current and all of these electrodes will have effects on the tissue underneath them. In this tutorial, we will share what we have learned about using tDCS to manipulate how the brain perceives, attends, remembers, and responds to information from our environment. Our goal is to provide a starting point for new users of tDCS and spur discussion of the standardization of methods to enhance replicability.

Anodal tDCS to V1 blocks visual perceptual learning consolidation.

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Peters, Megan A K; Thompson, Benjamin; Merabet, Lotfi B; Wu, Allan D; Shams, Ladan

2013-06-01

This study examined the effects of visual cortex transcranial direct current stimulation (tDCS) on visual processing and learning. Participants performed a contrast detection task on two consecutive days. Each session consisted of a baseline measurement followed by measurements made during active or sham stimulation. On the first day, one group received anodal stimulation to primary visual cortex (V1), while another received cathodal stimulation. Stimulation polarity was reversed for these groups on the second day. The third (control) group of subjects received sham stimulation on both days. No improvements or decrements in contrast sensitivity relative to the same-day baseline were observed during real tDCS, nor was any within-session learning trend observed. However, task performance improved significantly from Day 1 to Day 2 for the participants who received cathodal tDCS on Day 1 and for the sham group. No such improvement was found for the participants who received anodal stimulation on Day 1, indicating that anodal tDCS blocked overnight consolidation of visual learning, perhaps through engagement of inhibitory homeostatic plasticity mechanisms or alteration of the signal-to-noise ratio within stimulated cortex. These results show that applying tDCS to the visual cortex can modify consolidation of visual learning. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development of structural schemes of parallel structure manipulators using screw calculus

Science.gov (United States)

Rashoyan, G. V.; Shalyukhin, K. A.; Gaponenko, EV

2018-03-01

The paper considers the approach to the structural analysis and synthesis of parallel structure robots based on the mathematical apparatus of groups of screws and on a concept of reciprocity of screws. The results are depicted of synthesis of parallel structure robots with different numbers of degrees of freedom, corresponding to the different groups of screws. Power screws are applied with this aim, based on the principle of static-kinematic analogy; the power screws are similar to the orts of axes of not driven kinematic pairs of a corresponding connecting chain. Accordingly, kinematic screws of the outlet chain of a robot are simultaneously determined which are reciprocal to power screws of kinematic sub-chains. Solution of certain synthesis problems is illustrated with practical applications. Closed groups of screws can have eight types. The three-membered groups of screws are of greatest significance, as well as four-membered screw groups [1] and six-membered screw groups. Three-membered screw groups correspond to progressively guiding mechanisms, to spherical mechanisms, and to planar mechanisms. The four-membered group corresponds to the motion of the SCARA robot. The six-membered group includes all possible motions. From the works of A.P. Kotelnikov, F.M. Dimentberg, it is known that closed fifth-order screw groups do not exist. The article presents examples of the mechanisms corresponding to the given groups.

Effect of Nonviral Plasmid Delivered Basic Fibroblast Growth Factor and Low Intensity Pulsed Ultrasound on Mandibular Condylar Growth: A Preliminary Study

Directory of Open Access Journals (Sweden)

Harmanpreet Kaur

2014-01-01

Full Text Available Objective. Basic fibroblast growth factor (bFGF is an important regulator of tissue growth. Previous studies have shown that low intensity pulsed ultrasound (LIPUS stimulates bone growth. The objective of this study was to evaluate the possible synergetic effect of LIPUS and local injection of nonviral bFGF plasmid DNA (pDNA on mandibular growth in rats. Design. Groups were control, blank pDNA, bFGF pDNA, LIPUS, and bFGF pDNA + LIPUS. Treatments were performed for 28 days. Significant increase was observed in mandibular height and condylar length in LIPUS groups. MicroCT analysis showed significant increase in bone volume fraction in bFGF pDNA + LIPUS group. Histomorphometric analysis showed increased cell count and condylar proliferative and hypertrophic layers widths in bFGF pDNA group. Results. Current study showed increased mandibular condylar growth in either bFGF pDNA or LIPUS groups compared to the combined group that showed only increased bone volume fraction. Conclusion. It appears that there is an additive effect of bFGF + LIPUS on the mandibular growth.

Concomitant Suppurative Parotitis and Condylar Osteomyelitis.

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Vorrasi, John; Zinberg, Geoffrey

2017-03-01

Parotitis is a common occurrence in the immunocompromised, dehydrated, and malnourished patient as a result of dysfunctional ductal and parotid cells. Inflammation can be acute or chronic based on clinical history, and it can be suppurative based on the presence of micro or macro abscess formation within the substance of the gland. This report presents a case of concomitant condylar osteomyelitis and chronic suppurative parotitis in the setting of previous methicillin-susceptible Staphylococcus aureus foot infection. Ultimately, resection of osteomyelitis, drainage of parotid infection, and intravenous antibiotic therapy led to full resolution of the infection and symptoms. The final pathology of osteomyelitis of the temporomandibular joint and methicillin-resistant S aureus infection is an unusual consequence of chronic parotitis. The patient was restored with a total joint replacement approximately 3 months after resection with no recurrence of infection after 24 months. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Evidence-based guidelines on the therapeutic use of transcranial direct current stimulation (tDCS).

Science.gov (United States)

Lefaucheur, Jean-Pascal; Antal, Andrea; Ayache, Samar S; Benninger, David H; Brunelin, Jérôme; Cogiamanian, Filippo; Cotelli, Maria; De Ridder, Dirk; Ferrucci, Roberta; Langguth, Berthold; Marangolo, Paola; Mylius, Veit; Nitsche, Michael A; Padberg, Frank; Palm, Ulrich; Poulet, Emmanuel; Priori, Alberto; Rossi, Simone; Schecklmann, Martin; Vanneste, Sven; Ziemann, Ulf; Garcia-Larrea, Luis; Paulus, Walter

2017-01-01

A group of European experts was commissioned by the European Chapter of the International Federation of Clinical Neurophysiology to gather knowledge about the state of the art of the therapeutic use of transcranial direct current stimulation (tDCS) from studies published up until September 2016, regarding pain, Parkinson's disease, other movement disorders, motor stroke, poststroke aphasia, multiple sclerosis, epilepsy, consciousness disorders, Alzheimer's disease, tinnitus, depression, schizophrenia, and craving/addiction. The evidence-based analysis included only studies based on repeated tDCS sessions with sham tDCS control procedure; 25 patients or more having received active treatment was required for Class I, while a lower number of 10-24 patients was accepted for Class II studies. Current evidence does not allow making any recommendation of Level A (definite efficacy) for any indication. Level B recommendation (probable efficacy) is proposed for: (i) anodal tDCS of the left primary motor cortex (M1) (with right orbitofrontal cathode) in fibromyalgia; (ii) anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) (with right orbitofrontal cathode) in major depressive episode without drug resistance; (iii) anodal tDCS of the right DLPFC (with left DLPFC cathode) in addiction/craving. Level C recommendation (possible efficacy) is proposed for anodal tDCS of the left M1 (or contralateral to pain side, with right orbitofrontal cathode) in chronic lower limb neuropathic pain secondary to spinal cord lesion. Conversely, Level B recommendation (probable inefficacy) is conferred on the absence of clinical effects of: (i) anodal tDCS of the left temporal cortex (with right orbitofrontal cathode) in tinnitus; (ii) anodal tDCS of the left DLPFC (with right orbitofrontal cathode) in drug-resistant major depressive episode. It remains to be clarified whether the probable or possible therapeutic effects of tDCS are clinically meaningful and how to optimally perform tDCS

CT provides precise size assessment of implanted titanium alloy pedicle screws.

Science.gov (United States)

Elliott, Michael J; Slakey, Joseph B

2014-05-01

After performing instrumented spinal fusion with pedicle screws, postoperative imaging using CT to assess screw position may be necessary. Stainless steel implants produce significant metal artifact on CT, and the degree of distortion is at least partially dependent on the cross-sectional area of the implanted device. If the same effect occurs with titanium alloy implants, ability to precisely measure proximity of screws to adjacent structures may be adversely affected as screw size increases. We therefore asked whether (1) CT provides precise measurements of true screw widths; and (2) precision degrades based on the size of the titanium implant imaged. CT scans performed on 20 patients after instrumented spinal fusion for scoliosis were reviewed. The sizes of 151 titanium alloy pedicle screws were measured and compared with known screw size. The amount of metal bloom artifact was determined for each of the four screw sizes. ANOVA with Tukey's post hoc test were performed to evaluate differences in scatter, and Spearman's rho coefficient was used to measure relationship between screw size and scatter. All screws measured larger than their known size, but even with larger 7-mm screws the size differential was less than 1 mm. The four different screw sizes produced scatter amounts that were different from each other (p titanium alloy pedicle screws produces minimal artifact, thus making this the preferred imaging modality to assess screw position after surgery. Although the amount of artifact increases with the volume of titanium present, the degree of distortion is minimal and is usually less than 1 mm.

Fate of the syndesmotic screw--Search for a prudent solution.

Science.gov (United States)

Kaftandziev, Igor; Spasov, Marko; Trpeski, Simon; Zafirova-Ivanovska, Beti; Bakota, Bore

2015-11-01

Ankle fractures are common injuries. Since the recognition of the importance of syndesmotic injury in ankle fractures, much of the scientific work has been focused on concomitant syndesmotic injury. Despite the invention of novel devices for restoration and maintenance of the congruent syndesmosis following syndesmotic injury, the metallic syndesmotic screw is still considered to be the "gold standard". The aim of this study was to compare the clinical results in patients who retained the syndesmosis screw with those in whom the screw was removed following open reduction and internal fixation of the malleolar fracture associated with syndesmosis disruption. This was a retrospective study of 82 patients. Minimum follow-up was 12 months. Clinical evaluation included American Orthopaedic Foot and Ankle Society (AOFAS) score and Visual Analogue Scale (VAS) for patient general satisfaction. The condition of the screw (removed, intact or broken), presence of radiolucency around the syndesmotic screw and the tibiofibular clear space were recorded using final follow-up radiographs. Three cortices were engaged in 66 patients (80%) and quadricortical fixation was performed in the remaining 16 patients (20%). The number of engaged cortices did not correlate with the clinical outcome and screw fracture. A single syndesmotic screw was used in 71 patients (86%. The mean AOFAS score in the group with intact screw (I) was 83; the scores in the group with broken screw (B) and removed screw (R) were 92.5 and 85.5, respectively. There was a statistically significant difference between the three groups: this was due to the difference between groups I and B; the difference between groups I and R and groups B and R were not statistically significant. There were no statistically significant differences in VAS results. There were no statistically significant differences in clinical outcome between the group with the screw retained and the group in which the screw was removed; however, the

Clinical Research with Transcranial Direct Current Stimulation (tDCS): Challenges and Future Directions

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Brunoni, Andre Russowsky; Nitsche, Michael A.; Bolognini, Nadia; Bikson, Marom; Wagner, Tim; Merabet, Lotfi; Edwards, Dylan J.; Valero-Cabre, Antoni; Rotenberg, Alexander; Pascual-Leone, Alvaro; Ferrucci, Roberta; Priori, Alberto; Boggio, Paulo; Fregni, Felipe

2011-01-01

Background Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity, direct current to cortical areas facilitating or inhibiting spontaneous neuronal activity. In the past ten years, tDCS physiological mechanisms of action have been intensively investigated giving support for the investigation of its applications in clinical neuropsychiatry and rehabilitation. However, new methodological, ethical, and regulatory issues emerge when translating the findings of preclinical and phase I studies into phase II and III clinical studies. The aim of this comprehensive review is to discuss the key challenges of this process and possible methods to address them. Methods We convened a workgroup of researchers in the field to review, discuss and provide updates and key challenges of neuromodulation use for clinical research. Main Findings/Discussion We reviewed several basic and clinical studies in the field and identified potential limitations, taking into account the particularities of the technique. We review and discuss the findings into four topics: (i) mechanisms of action of tDCS, parameters of use and computer-based human brain modeling investigating electric current fields and magnitude induced by tDCS; (ii) methodological aspects related to the clinical research of tDCS as divided according to study phase (i.e., preclinical, phase I, phase II and phase III studies); (iii) ethical and regulatory concerns; (iv) future directions regarding novel approaches, novel devices, and future studies involving tDCS. Finally, we propose some alternative methods to facilitate clinical research on tDCS. PMID:22037126

Clinical predictors of acute response to transcranial direct current stimulation (tDCS) in major depression.

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D'Urso, Giordano; Dell'Osso, Bernardo; Rossi, Rodolfo; Brunoni, Andre Russowsky; Bortolomasi, Marco; Ferrucci, Roberta; Priori, Alberto; de Bartolomeis, Andrea; Altamura, Alfredo Carlo

2017-09-01

Transcranial direct current stimulation (tDCS) is a promising neuromodulation intervention for poor-responding or refractory depressed patients. However, little is known about predictors of response to this therapy. The present study aimed to analyze clinical predictors of response to tDCS in depressed patients. Clinical data from 3 independent tDCS trials on 171 depressed patients (including unipolar and bipolar depression), were pooled and analyzed to assess predictors of response. Depression severity and the underlying clinical dimensions were measured using the Hamilton Depression Rating Scale (HDRS) at baseline and after the tDCS treatment. Age, gender and diagnosis (bipolar/unipolar depression) were also investigated as predictors of response. Linear mixed models were fitted in order to ascertain which HDRS factors were associated with response to tDCS. Age, gender and diagnosis did not show any association with response to treatment. The reduction in HDRS scores after tDCS was strongly associated with the baseline values of "Cognitive Disturbances" and "Retardation" factors, whilst the "Anxiety/Somatization" factor showed a mild association with the response. Open-label design, the lack of control group, and minor differences in stimulation protocols. No differences in response to tDCS were found between unipolar and bipolar patients, suggesting that tDCS is effective for both conditions. "Cognitive disturbance", "Retardation", and "Anxiety/Somatization", were identified as potential clinical predictors of response to tDCS. These findings point to the pre-selection of the potential responders to tDCS, therefore optimizing the clinical use of this technique and the overall cost-effectiveness of the psychiatric intervention for depressed patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Acute working memory improvement after tDCS in antidepressant-free patients with major depressive disorder.

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Oliveira, Janaina F; Zanão, Tamires A; Valiengo, Leandro; Lotufo, Paulo A; Benseñor, Isabela M; Fregni, Felipe; Brunoni, André R

2013-03-14

Based on previous studies showing that transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique that employs weak, direct currents to induce cortical-excitability changes, might be useful for working memory (WM) enhancement in healthy subjects and also in treating depressive symptoms, our aim was to evaluate whether tDCS could acutely enhance WM in depressed patients. Twenty-eight age- and gender-matched, antidepressant-free depressed subjects received a single-session of active/sham tDCS in a randomized, double-blind, parallel design. The anode was positioned over the left and the cathode over the right dorsolateral prefrontal cortex. The n-back task was used for assessing WM and it was performed immediately before and 15min after tDCS onset. We found that active vs. sham tDCS led to an increase in the rate of correct responses. We also used signal detection theory analyses to show that active tDCS increased both discriminability, i.e., the ability to discriminate signal (correct responses) from noise (false alarms), and response criterion, indicating a lower threshold to yield responses. All effect sizes were large. In other words, one session of tDCS acutely enhanced WM in depressed subjects, suggesting that tDCS can improve "cold" (non affective-loaded) working memory processes in MDD. Based on these findings, we discuss the effects of tDCS on WM enhancement in depression. We also suggest that the n-back task could be used as a biomarker in future tDCS studies investigating prefrontal activity in healthy and depressed samples. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Condylectomy and “surgery first” approach: An expedited treatment for condylar hyperplasia in a patient with facial asymmetry

Science.gov (United States)

López, Diego Fernando; Aristizábal, Juan Fernando; Martínez-Smit, Rosana

2017-01-01

ABSTRACT Condylar Hyperplasia (CH) is a self-limiting pathology condition that produces severe facial deformity at the expense of mandibular asymmetry. In this case report a 15-year-old female patient was diagnosed with Unilateral Condylar Hiperplasia (UCH) by mean of single-photon emission computed tomography (SPECT) and histological study. A high condylectomy in the right condyle was performed to stop the active status of the hyperplasia. A month after condylectomy, orthognathic jaw impaction and asymmetric mandibular setback surgery was performed with the Surgery First Approach (SFA). After 10 days, orthodontic appointments were made every two weeks during 4 months. The active phase of treatment lasted 14 months. Excellent facial and occlusal outcomes were obtained and after 24 months in retention the results remained stable. PMID:28902254

Custom total knee replacement in a dog with femoral condylar bone loss.

Science.gov (United States)

Liska, William D; Marcellin-Little, Denis J; Eskelinen, Esa V; Sidebotham, Christopher G; Harrysson, Ola L A; Hielm-Björkman, Anna K

2007-06-01

To report surgical planning, technique, and outcome of custom total knee replacement (TKR) performed to manage a medial femoral condylar nonunion in a dog. Clinical case report. A 3-year-old, 20 kg Karelian Bear Hound. Computed tomographic scan of the left pelvic limb was used to build a stereolithography model of the distal portion of the femur. The model was used to create a custom augment to replace the missing medial femoral condyle and a custom stem for intramedullary condylar cemented fixation. The augment and stem were adapted to femoral and tibial components already available. The model was used to rehearse the surgery and then the custom prosthesis was implanted. Weight bearing returned 8 hours after surgery and improved thereafter. Joint alignment was normal and prosthetic joint motion was 60-165 degrees postoperatively. The dog resumed moose hunting 3 months after surgery. Peak vertical force and impulse of the operated limb measured 17 months after surgery were 65% and 47% of the normal, contralateral limb. Based on short-term follow-up, cemented canine TKR was successfully achieved for management of a severely abnormal stifle joint. With further refinement and development of commercially available prostheses, TKR should be possible for canine patients.

THE MANAGEMENT OF LIMITED MANDIBULAR MOVEMENT CAUSED BY CONDYLAR FRACTURE WITH REPOSITIONING SPLINT

Directory of Open Access Journals (Sweden)

Ira Tanti

2015-06-01

Full Text Available Fractures of the neck of condyle usually are the result of a blow to the mandible. A lateral blow to the body of the mandible commonly causes a contralateral condyle fracture. There are many signs and symptoms of a condylar fracture, for example crepitation, deviation of the mandible to the side of injury, and spasm of the associated group of muscles. These will result in a functional disability, which is usually seen as a limited mandibular movement. This paper reported a patient with a fracture of the condylar neck. Patient had been treated with closed reduction and immobilization for 2 months. After that, she felt that her bite was changed, she could not occlude her teeth well, and she had clicking sound in the right joint when she opened her mouth. Besides that, patient had difficulties to move the mandible to the left side, and she could not open her mouth widely. The patient was treated with a repositioning splint and she had to do some jaw exercises. The purposes were to regain the position of condyle, to reduce the muscle spasm and finally got the normal jaw movement.

Economics of water injected air screw compressor systems

Science.gov (United States)

Venu Madhav, K.; Kovačević, A.

2015-08-01

There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an investigation carried out to determine the current limitations of water injected screw compressor systems and how these could be overcome in the 15-315 kW power range and delivery pressures of 6-10 bar. Modern rotor profiles and approach to sealing and cooling allow reasonably inexpensive air end design. The prototype of the water injected screw compressor air system was built and tested for performance and reliability. The water injected compressor system was compared with the oil injected and oil free compressor systems of the equivalent size including the economic analysis based on the lifecycle costs. Based on the obtained results, it was concluded that water injected screw compressor systems could be designed to deliver clean air free of oil contamination with a better user value proposition than the oil injected or oil free screw compressor systems over the considered range of operations.

First Metatarsophalangeal Joint Arthrodesis: A Retrospective Comparison of Crossed-screws, Locking and Non-Locking Plate Fixation with Lag Screw

Directory of Open Access Journals (Sweden)

Leif Claassen

2017-07-01

Full Text Available Background:Locking plate fixation is increasingly used for first metatarsophalangeal joint (MTP-I arthrodesis. Still there is few comparable clinical data regarding this procedure. Methods:We retrospectively evaluated 60 patients who received an arthrodesis of the MTP-I between January 2008 and June 2010. With 20 patients each we performed a locking plate fixation with lag screw, arthrodesis with crossed-screwsor with a nonlocking plate with lag screw. Results: There were four non-unions in crossed-screws patients and one nonunion in non-locked plate group. All the patients in locking plate group achieved union. 90% of the patients were completely or mildly satisfied in locking plate group, whereas this rate was 80% for patients in both crossed screws and non-locking plate groups. Conclusions: Use of dorsal plating for arthrodesis of MTP1 joint either locking or non-locking were associated with high union rate and acceptable and comparable functional outcome. Although nonunion rate was high using two crossed screws but functional outcome was not significantly different compare to dorsal plating. Level of evidence:Ш, retrospective comparative study

The Effects of Transcranial Direct Current Stimulation (tDCS on Multitasking Throughput Capacity

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Justin Nelson

2016-11-01

Full Text Available Background: Multitasking has become an integral attribute associated with military operations within the past several decades. As the amount of information that needs to be processed during these high level multitasking environments exceeds the human operators’ capabilities, the information throughput capacity reaches an asymptotic limit. At this point, the human operator can no longer effectively process and respond to the incoming information resulting in a plateau or decline in performance. The objective of the study was to evaluate the efficacy of a non-invasive brain stimulation technique known as transcranial direct current stimulation (tDCS applied to a scalp location over the left dorsolateral prefrontal cortex (lDLPFC to improve information processing capabilities during a multitasking environment. Methods: The study consisted of 20 participants from Wright-Patterson Air Force Base (16 male and 4 female with an average age of 31.1 (SD = 4.5. Participants were randomly assigned into two groups, each consisting of eight males and two females. Group one received 2mA of anodal tDCS and group two received sham tDCS over the lDLPFC on their testing day. Results: The findings indicate that anodal tDCS significantly improves the participants’ information processing capability resulting in improved performance compared to sham tDCS. For example, the multitasking throughput capacity for the sham tDCS group plateaued near 1.0 bits/s at the higher baud input (2.0 bits/s whereas the anodal tDCS group plateaued near 1.3 bits/s. Conclusion: The findings provided new evidence that tDCS has the ability to augment and enhance multitasking capability in a human operator. Future research should be conducted to determine the longevity of the enhancement of transcranial direct current stimulation on multitasking performance, which has yet to be accomplished.

The Effects of Transcranial Direct Current Stimulation (tDCS) on Multitasking Throughput Capacity.

Science.gov (United States)

Nelson, Justin; McKinley, Richard A; Phillips, Chandler; McIntire, Lindsey; Goodyear, Chuck; Kreiner, Aerial; Monforton, Lanie

2016-01-01

Background: Multitasking has become an integral attribute associated with military operations within the past several decades. As the amount of information that needs to be processed during these high level multitasking environments exceeds the human operators' capabilities, the information throughput capacity reaches an asymptotic limit. At this point, the human operator can no longer effectively process and respond to the incoming information resulting in a plateau or decline in performance. The objective of the study was to evaluate the efficacy of a non-invasive brain stimulation technique known as transcranial direct current stimulation (tDCS) applied to a scalp location over the left dorsolateral prefrontal cortex (lDLPFC) to improve information processing capabilities during a multitasking environment. Methods: The study consisted of 20 participants from Wright-Patterson Air Force Base (16 male and 4 female) with an average age of 31.1 (SD = 4.5). Participants were randomly assigned into two groups, each consisting of eight males and two females. Group one received 2 mA of anodal tDCS and group two received sham tDCS over the lDLPFC on their testing day. Results: The findings indicate that anodal tDCS significantly improves the participants' information processing capability resulting in improved performance compared to sham tDCS. For example, the multitasking throughput capacity for the sham tDCS group plateaued near 1.0 bits/s at the higher baud input (2.0 bits/s) whereas the anodal tDCS group plateaued near 1.3 bits/s. Conclusion: The findings provided new evidence that tDCS has the ability to augment and enhance multitasking capability in a human operator. Future research should be conducted to determine the longevity of the enhancement of transcranial direct current stimulation on multitasking performance, which has yet to be accomplished.

[Topographological-anatomic changes in the structure of temporo-mandibular joint in case of fracture of the mandible condylar process at cervical level].

Science.gov (United States)

Volkov, S I; Bazhenov, D V; Semkin, V A

2011-01-01

Pathological changes in soft tissues surrounding the fracture site as well as in the structural elements of temporo-mandibular joint always occured in condylar process fracture with shift at cervical mandibular jaw level. Other changes were also seen in the joint on the opposite normal side. Modelling of condylar process fracture at mandibular cervical level by means of three-dimensional computer model of temporo-mandibular joint contributed to proper understanding of this pathology emergence as well as to prediction and elimination of disorders arising in adjacent to the fracture site tissues.

Biomechanical comparison of osteosynthesis with poly‑L‑lactic acid ...

African Journals Online (AJOL)

Background and Aims: The aim of this study was to compare the biomechanical stability of poly‑L‑lactic acid and titanium screws in the fixation of intracapsular condylar fractures, in 10 polyurethane hemimandibles. Materials and Methods: Artificial intracapsular fractures were created with a steel disk and electronic ...

Effect of tDCS with an extracephalic reference electrode on cardio-respiratory and autonomic functions

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Jamart Jacques

2010-03-01

Full Text Available Abstract Background Transcranial direct current stimulation (tDCS is used in human physiological studies and for therapeutic trials in patients with abnormalities of cortical excitability. Its safety profile places tDCS in the pole-position for translating in real-world therapeutic application. However, an episode of transient respiratory depression in a subject receiving tDCS with an extracephalic electrode led to the suggestion that such an electrode montage could modulate the brainstem autonomic centres. We investigated whether tDCS applied over the midline frontal cortex in 30 healthy volunteers (sham n = 10, cathodal n = 10, anodal n = 10 with an extracephalic reference electrode would modulate brainstem activity as reflected by the monitoring and stringent analysis of vital parameters: heart rate (variability, respiratory rate, blood pressure and sympatho-vagal balance. We reasoned that this study could lead to two opposite but equally interesting outcomes: 1 If tDCS with an extracephalic electrode modulated vital parameters, it could be used as a new tool to explore the autonomic nervous system and, even, to modulate its activity for therapeutic purposes. 2 On the opposite, if applying tDCS with an extracephalic electrode had no effect, it could thus be used safely in healthy human subjects. This outcome would significantly impact the field of non-invasive brain stimulation with tDCS. Indeed, on the one hand, using an extracephalic electrode as a genuine neutral reference (as opposed to the classical "bi-cephalic" tDCS montages which deliver bi-polar stimulation of the brain would help to comfort the conclusions of several modern studies regarding the spatial location and polarity of tDCS. On the other hand, using an extracephalic reference electrode may impact differently on a given cortical target due to the change of direct current flow direction; this may enlarge the potential interventions with tDCS. Results Whereas the respiratory

DCS cabinet power loss analysis for CPR1000 nuclear power plant

International Nuclear Information System (INIS)

Zhou Liang; Zhao Yanfeng; Sun Yongbin

2014-01-01

The DCS overall structure of CRP1000 nuclear power plant was introduced. Based on the RPC, the signal interface character and signal processing mechanism on the key root were analyzed. By the power loss analyzing of RPC, the RPC loss power may lead reactor trip signal from anticipated transient without scram (ATWS) system. The results indicate that it is necessary to search DCS cabinet power loss analysis. Optimizing and assigning the main water flow signals can avoid trigger reactor trip signal by mistake. The DCS cabinet power loss analysis can optimize the I and C (instrumentation and control) design and increase the nuclear plant's reliability. (authors)

Modified endaural approach for the treatment of condylar fractures: A review of 75 cases

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S M Balaji

2016-01-01

Conclusion: Surgery for mandibular condyle fractures with modified approach allows direct vision of the fracture and reduces surgical trauma to the site while avoiding permanent facial nerve injury. Hence, the author's modified Al-Kayat Bramley incision via endaural approach could be considered as the best approach for open reduction and internal fixation of condylar neck and subcondylar mandibular fractures.

Anodal tDCS applied during multitasking training leads to transferable performance gains.

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Filmer, Hannah L; Lyons, Maxwell; Mattingley, Jason B; Dux, Paul E

2017-10-11

Cognitive training can lead to performance improvements that are specific to the tasks trained. Recent research has suggested that transcranial direct current stimulation (tDCS) applied during training of a simple response-selection paradigm can broaden performance benefits to an untrained task. Here we assessed the impact of combined tDCS and training on multitasking, stimulus-response mapping specificity, response-inhibition, and spatial attention performance in a cohort of healthy adults. Participants trained over four days with concurrent tDCS - anodal, cathodal, or sham - applied to the left prefrontal cortex. Immediately prior to, 1 day after, and 2 weeks after training, performance was assessed on the trained multitasking paradigm, an untrained multitasking paradigm, a go/no-go inhibition task, and a visual search task. Training combined with anodal tDCS, compared with training plus cathodal or sham stimulation, enhanced performance for the untrained multitasking paradigm and visual search tasks. By contrast, there were no training benefits for the go/no-go task. Our findings demonstrate that anodal tDCS combined with multitasking training can extend to untrained multitasking paradigms as well as spatial attention, but with no extension to the domain of response inhibition.

An Alternative Method of Intermaxillary Fixation for Simple Pediatric Mandible Fractures.

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Farber, Scott J; Nguyen, Dennis C; Harvey, Alan A; Patel, Kamlesh B

2016-03-01

Mandibular fractures represent a substantial portion of facial fractures in the pediatric population. Pediatric mandibles differ from their adult counterparts in the presence of mixed dentition. Avoidance of injury to developing tooth follicles is critical. Simple mandibular fractures can be treated with intermaxillary fixation (IMF) using arch bars or bone screws. This report describes an alternative to these methods using silk sutures and an algorithm to assist in treating simple mandibular fractures in the pediatric population. A retrospective chart review was performed and the records of 1 surgeon were examined. Pediatric patients who underwent treatment for a mandibular fracture in the operating room from 2011 to 2015 were identified using Common Procedural Terminology codes. Data collected included age, gender, type of fracture, type of treatment used, duration of fixation, and presence of complications. Five patients with a mean age of 6.8 years at presentation were identified. Fracture types were unilateral fractures of the condylar neck (n = 3), bilateral fractures of the condylar head (n = 1), and a unilateral fracture of the condylar head with an associated parasymphyseal fracture (n = 1). IMF was performed in 4 patients using silk sutures, and bone screw fixation was performed in the other patient. No post-treatment complications or malocclusion were reported. Average duration of IMF was 18.5 days. An algorithm is presented to assist in the treatment of pediatric mandibular fractures. Silk suture fixation is a viable and safe alternative to arch bars or bone screws for routine mandibular fractures. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Effects of HD-tDCS on memory and metamemory for general knowledge questions that vary by difficulty

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Chua, Elizabeth F.; Ahmed, Rifat; Garcia, Sandry

2016-01-01

Background The ability to monitor one’s own memory is an important feature of normal memory and is an aspect of ‘metamemory’. Lesion studies have shown dissociations between memory and metamemory, but only single dissociations have been shown using transcranial direct current stimulation (tDCS). One potential reason that only single dissociations have been shown is that tDCS effects may be moderated by task difficulty. Objective/Hypothesis We used high definition (HD) tDCS to test for dissociable roles of the dorsolateral prefrontal cortex (DLPFC) and anterior temporal lobe (ATL) in semantic long-term memory and metamemory tasks. We also tested whether general knowledge question difficulty moderated the effects of HD-tDCS. Methods Across 3 sessions, participants received active HD-tDCS over the left DLPFC or left ATL, or sham HD-tDCS during general knowledge recall and recognition tests, and a ‘feeling-of-knowing’ metamemory task. General knowledge questions were blocked by difficulty. Repeated measures ANOVAs were used to examine the effects of HD-tDCS on memory and metamemory tasks by memory question difficulty. Results HD-tDCS over the ATL led to improved recall compared to DLPFC and sham HD-tDCS, and this occurred only for medium difficulty questions. In contrast, for non-recalled questions, HD-tDCS over the DLPFC led to improved recognition accuracy and improved feeling-of-knowing accuracy compared to ATL and sham HD-tDCS, and this was not moderated by memory question difficulty. Conclusion(s) HD-tDCS can be used to dissociate the roles of the ATL and DLPFC in different memory and ‘metamemory’ tasks. The effects of HD-tDCS on task may be moderated by task difficulty, depending on the nature of the task and site of stimulation. PMID:27876306

Transcranial direct-current stimulation (tDCS) for bipolar depression: A systematic review and meta-analysis.

Science.gov (United States)

Dondé, Clément; Amad, Ali; Nieto, Isabel; Brunoni, André Russowsky; Neufeld, Nicholas H; Bellivier, Frank; Poulet, Emmanuel; Geoffroy, Pierre-Alexis

2017-08-01

Bipolar disorder (BD) is a severe and recurrent brain disorder that can manifest in manic or depressive episodes. Transcranial Direct Current Stimulation (tDCS) has been proposed as a novel therapeutic modality for patients experiencing bipolar depression, for which standard treatments are often inefficient. While several studies have been conducted in this patient group, there has been no systematic review or meta-analysis that specifically examines bipolar depression. We aimed to address this gap in the literature and evaluated the efficacy and tolerability of tDCS in patients fulfilling DSM-IV-TR criteria for BD I, II, or BD not otherwise specified (NOS). We systematically searched the literature from April 2002 to November 2016 to identify relevant publications for inclusion in our systematic review and meta-analysis. Effect sizes for depression rating-scale scores were expressed as the standardized mean difference (SMD) before and after tDCS. Thirteen of 382 identified studies met eligibility criteria for our systematic review. The meta-analysis included 46 patients from 7 studies with depression rating-scale scores pre- and post-tDCS. Parameters of tDCS procedures were heterogeneous. Depression scores decreased significantly with a medium effect size after acute-phase of treatment (SMD 0.71 [0.25-1.18], z=3.00, p=0.003) and at the furthest endpoint (SMD 1.27 [0.57-1.97], z=3.57, p=0.0004). Six cases of affective switching under tDCS treatment protocols were observed. Depressive symptoms respond to tDCS in patients with BD. Additional studies, and particularly randomized controlled trials, are needed to clarify the effectiveness of tDCS in bipolar depression, the frequency of tDCS-emergent hypomania/mania, and which tDCS modalities are most efficient. Copyright © 2017 Elsevier Inc. All rights reserved.

Quantitative analysis by MRI on condylar motion of the temporomandibular joint in patients applied with occlusal splints

International Nuclear Information System (INIS)

Saito, Hiroki

1999-01-01

The purpose of this study was to assess the feasibility of a newly developed quantitative motion analysis method for the mandibular condyle before and after application of occlusal splints. The subjects were 50 consecutive patients with internal derangement. Stabilization type splints were applied in 23 cases (46%), anterior repositioning type in 18 cases (36%) and pivot type in 9 cases (18%). All patients underwent MR imaging with a 1.5-T MR unit with a 3-inch dual surface coil. Pseudodynamic MR study of the opening cycle was obtained using multiplanar GRASS sequence (MPGR). Incremental and decremental sagittal MR images before and after splint application were transferred to the workstation. Software originally developed by Nakasato and Katsuragawa was used to analyze the condylar motion and path. After splint application, normalized position of displaced discs was seen in 11 cases (22%), and occurred most frequently with anterior repositioning type splints. In patients with anterior repositioning type splints, improvement in the condylar motion was most significant, In patients with normalized disc position after application of occlusal splints, abnormal figure-eight-shaped'' condylar paths were corrected in 9 of 10 cases. In the case with normalized disc position after application of anterior repositioning splint, the maximum rotational angle before application of the splint is larger than that of the case without normalized disc position. Rotational function of the condyle in the inferior joint space may be associated with disc recapturing. (K.H.)

Screw-worm eradication in the Americas - Overview

International Nuclear Information System (INIS)

Wyss, John H.

2000-01-01

Screw-worms (Cochliomyia hominivorax, Coquerel) are found only in the Americas, and are known, therefore, as the New World Screw-worm (NWS). The larval stages of the fly feed on the living flesh of their host. A screw-worm infestation can kill an adult animal in 7-10 days if not treated. All warm-blooded animals are affected including man. Although screw-worms had long been recognised as a severe pest of animals in the southwestern United States, they had never been detected east of the Mississippi River before 1933. In July 1933, screw-worms were transported on infested cattle to Georgia and became established east of the Mississippi River. Screw-worms spread quickly in the southeastern United States and were able to overwinter in southern Florida. Being new to the region, they were quickly recognised as a severe pest with a tremendous economic impact on livestock production. The livestock owners in the southeastern United States immediately noticed an increase in the number of animal deaths and increased costs of insecticides, veterinary medicines, veterinary services, inspection and handling. At the same time, they observed a decrease in animal weights and in milk production. Due to these observations, the livestock industry in the southeastern United States requested help in controlling screw-worms. Because of these requests, the research community became interested in control and eradication measures for this pest. Early work by Crushing and Patton in 1933 recognised that C. hominivorax was an obligatory animal parasite and different from the secondary blowfly, Cochliomyia macellaria. In 1934, the US Department of Agriculture (USDA), Agricultural Research Service (ARS) opened a research station in Valdosa, Georgia, and E.W. Laake and E.F. Knipling were assigned to work there. In September 1935, R.C. Bushland was hired by ARS to do research related to screw-worms at an ARS Research Laboratory in Dallas, Texas. Melvin and Bushland in 1936 developed artificial

Feasibility of using high-definition transcranial direct current stimulation (HD-tDCS) to enhance treatment outcomes in persons with aphasia.

Science.gov (United States)

Richardson, Jessica; Datta, Abhishek; Dmochowski, Jacek; Parra, Lucas C; Fridriksson, Julius

2015-01-01

Transcranial direct current stimulation (tDCS) enhances treatment outcomes post-stroke. Feasibility and tolerability of high-definition (HD) tDCS (a technique that increases current focality and intensity) for consecutive weekdays as an adjuvant to behavioral treatment in a clinical population has not been demonstrated. To determine HD-tDCS feasibility outcomes: 1) ability to implement study as designed, 2) acceptability of repeated HD-tDCS administration to patients, and 3) preliminary efficacy. Eight patients with chronic post-stroke aphasia participated in a randomized crossover trial with two arms: conventional sponge-based (CS) tDCS and HD-tDCS. Computerized anomia treatment was administered for five consecutive days during each treatment arm. Individualized modeling/targeting procedures and an 8-channel HD-tDCS device were developed. CS-tDCS and HD-tDCS were comparable in terms of implementation, acceptability, and outcomes. Naming accuracy and response time improved for both stimulation conditions. Change in accuracy of trained items was numerically higher (but not statistically significant) for HD-tDCS compared to CS-tDCS for most patients. Regarding feasibility, HD-tDCS treatment studies can be implemented when designed similarly to documented CS-tDCS studies. HD-tDCS is likely to be acceptable to patients and clinicians. Preliminary efficacy data suggest that HD-tDCS effects, using only 4 electrodes, are at least comparable to CS-tDCS.

The accuracy and safety of fluoroscopically guided percutaneous pedicle screws in the lumbosacral junction and the lumbar spine: a review of 880 screws.

Science.gov (United States)

Chiu, C K; Kwan, M K; Chan, C Y W; Schaefer, C; Hansen-Algenstaedt, N

2015-08-01

We undertook a retrospective study investigating the accuracy and safety of percutaneous pedicle screws placed under fluoroscopic guidance in the lumbosacral junction and lumbar spine. The CT scans of patients were chosen from two centres: European patients from University Medical Center Hamburg-Eppendorf, Germany, and Asian patients from the University of Malaya, Malaysia. Screw perforations were classified into grades 0, 1, 2 and 3. A total of 880 percutaneous pedicle screws from 203 patients were analysed: 614 screws from 144 European patients and 266 screws from 59 Asian patients. The mean age of the patients was 58.8 years (16 to 91) and there were 103 men and 100 women. The total rate of perforation was 9.9% (87 screws) with 7.4% grade 1, 2.0% grade 2 and 0.5% grade 3 perforations. The rate of perforation in Europeans was 10.4% and in Asians was 8.6%, with no significant difference between the two (p = 0.42). The rate of perforation was the highest in S1 (19.4%) followed by L5 (14.9%). The accuracy and safety of percutaneous pedicle screw placement are comparable to those cited in the literature for the open method of pedicle screw placement. Greater caution must be taken during the insertion of L5 and S1 percutaneous pedicle screws owing to their more angulated pedicles, the anatomical variations in their vertebral bodies and the morphology of the spinal canal at this location. ©2015 The British Editorial Society of Bone & Joint Surgery.

Conceptual design of ball-screw type control element drive mechanism

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Ho; Kim, Jong In; Huh, Hyung [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-10-01

In this report, the design features of ball-screw type CEDM with fine-step movement capability are described. The contents of this report are as follows: -Review of Design Requirements for Ball-screw type CEDM -System Description for Ball-screw type CEDM -Design of Ball Bearing and Ball-screw Assembly -Detail Design of Rotary Step Motor -Detail Design of Angular Position Indicator -Materials. The Ball-screw type CEDM described in this report is to be utilized as the starting point for design development of CEDM for SMART. 11 refs., 43 figs., 3 tabs. (Author)

Passage of an Anterior Odontoid Screw through Gastrointestinal Tract.

Science.gov (United States)

Leitner, L; Brückmann, C I; Gilg, M M; Bratschitsch, G; Sadoghi, P; Leithner, A; Radl, R

2017-01-01

Purpose . Anterior screw fixation has become a popular surgical treatment method for instable odontoid fractures. Screw loosening and migration are a rare, severe complication following anterior odontoid fixation, which can lead to esophagus perforation and requires revision operation. Methods . We report a case of screw loosening and migration after anterior odontoid fixation, which perforated the esophagus and was excreted without complications in a 78-year-old male patient. Results . A ventral dislocated anterior screw perforated through the esophagus after eight years after implantation and was excreted through the gastrointestinal (GI) tract. At a 6-month follow-up after the event the patient was asymptomatic. Conclusion . Extrusion via the GI tract is not safe enough to be considered as a treatment option for loosened screws. Some improvements could be implemented to prevent such an incident. Furthermore, this case is a fine example that recent preoperative imaging is mandatory before revision surgery for screw loosening.

Passage of an Anterior Odontoid Screw through Gastrointestinal Tract

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L. Leitner

2017-01-01

Full Text Available Purpose. Anterior screw fixation has become a popular surgical treatment method for instable odontoid fractures. Screw loosening and migration are a rare, severe complication following anterior odontoid fixation, which can lead to esophagus perforation and requires revision operation. Methods. We report a case of screw loosening and migration after anterior odontoid fixation, which perforated the esophagus and was excreted without complications in a 78-year-old male patient. Results. A ventral dislocated anterior screw perforated through the esophagus after eight years after implantation and was excreted through the gastrointestinal (GI tract. At a 6-month follow-up after the event the patient was asymptomatic. Conclusion. Extrusion via the GI tract is not safe enough to be considered as a treatment option for loosened screws. Some improvements could be implemented to prevent such an incident. Furthermore, this case is a fine example that recent preoperative imaging is mandatory before revision surgery for screw loosening.

Range of motion, sacral screw and rod strain in long posterior spinal constructs: a biomechanical comparison between S2 alar iliac screws with traditional fixation strategies.

Science.gov (United States)

Sutterlin, Chester E; Field, Antony; Ferrara, Lisa A; Freeman, Andrew L; Phan, Kevin

2016-12-01

S1 screw failure and L5/S1 non-union are issues with long fusions to S1. Improved construct stiffness and S1 screw offloading can help avoid this. S2AI screws have shown to provide similar stiffness to iliac screws when added to L3-S1 constructs. We sought to examine and compare the biomechanical effects on an L2-S1 pedicle screw construct of adding S2AI screws, AxiaLIF, L5-S1 interbody support via transforaminal lumbar interbody fusion (TLIF), and to examine the effect of the addition of cross connectors to each of these constructs. Two S1 screws and one rod with strain gauges (at L5/S1) were used in L2-S1 screw-rod constructs in 7 L1-pelvis specimens (two with low BMD). ROM, S1 screw and rod strain were assessed using a pure-moment flexibility testing protocol. Specimens were tested intact, and then in five instrumentation states consisting of: (I) Pedicle screws (PS) L2-S1; (II) PS + S2AI screws; (III) PS + TLIF L5/S1; (IV) PS + AxiaLIF L5/S1; (V) PS + S2AI + AxiaLIF L5/S1. The five instrumentation conditions were also tested with crosslinks at L2/3 and S1/2. Tests were conducted in flexion-extension, lateral bending and axial torsion with no compressive preload. S2A1 produces reduced S1 screw strain for flexion-extension, lateral bending and axial torsion, as well as reduced rod strain in lateral bending and axial torsion in comparison to AxiaLIF and interbody instrumentation, at the expense of increased rod flexion-extension strain. Cross-connectors may have a role in further reduction of S1 screw and rod strain. From a biomechanical standpoint, the use of the S2AI technique is at least equivalent to traditional iliac screws, but offers lower prominence and ease of assembly compared to conventional sacroiliac stabilization.

The Role of Telehealth to Assist In-Home tDCS: Opportunities, Promising Results and Acceptability

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Brenton Hordacre

2018-06-01

Full Text Available Transcranial direct current stimulation (tDCS has shown great promise as a neuromodulatory intervention capable of improving behavioral outcomes in a range of neurological and psychiatric populations. Evidence indicates that the neuromodulatory effect of stimulation may be cumulative, with greater improvements in behavior observed following multiple treatment sessions. However, the requirement to attend clinical or research departments for multiple treatment sessions may present a barrier for many people, particularly those with greater disability or living remotely. The portability of tDCS suggests that in-home stimulation may become an avenue for further investigation. However, safe and effective use of tDCS by a participant within their home requires a form of monitoring. This review discusses how telehealth may provide real-time visual monitoring to ensure correct tDCS set-up and adherence to stimulation protocols, manage technical issues and monitor adverse events. The combination of telehealth to supplement in-home tDCS use has potential to transform the way tDCS is delivered.

Experimental study of pedicle screw stability on low BMD vertebrae

International Nuclear Information System (INIS)

Li Qi; Yang Huilin; Tang Tiansi; Wu Yiwei; Wang Yijin

2005-01-01

Objective: To conduct biomechanical study of different pedicle screws stability on spinal specimen, discuss the relationship between design parameter of screw, insertion torgue and BMD, establish the theoretical foundation for application of pedicle screw on osteoporotic patients. Methods: Six fixed lumbar cadavers were collected, the effects of design parameter, insertion torque and etc on fixation stability were determined under various BMD by using biomechanical ways. Results: According to in vitro study: (1) There was a significant difference among pullout strength of all screws (P 2 >U 1 >SF 1 >SF 2 >RF. Conclusions: There is a close correlated between type of screw, BMD and stability. The U-type screw displays the best fixation effect on specimen of low BMD. (authors)

Safety and surgical techniques of C1 lateral mass screws

International Nuclear Information System (INIS)

Kubo, Shinichiro; Kuroki, Hiroshi; Hanado, Shoji; Hamanaka, Hideaki; Inomata, Naoki; Kuroki, Shuji; Chosa, Etsuo

2010-01-01

The objectives of this study were to evaluate the proper insertion techniques of C1 lateral mass screws. Eighteen consecutive patients were examined after upper cervical fusion using twenty-nine C1 lateral mass screws. Screws were placed by three different techniques; Goel's technique (4), Tan's technique (20), Notching technique (5). Pre and post-operative CT scans with multiplanar reconstruction were used to detect cortical breaches and direction of screws. No transverse foramen and vertebral groove violation was found in CT scans. Three had breached superior articular facet of the atlas. However, the range of motion (R.O.M) of atlanto-occipital joints had not changed postoperatively. Theses screws were inserted with Tan's technique and two of three were directed medially. It is feasible to safely insert C1 lateral mass screws when correct insertion point and direction are considered preoperatively. However, care should be taken because screws can violate the atlanto-occipital joint especially with Tan's technique. (author)

Condylectomy and “surgery first” approach: An expedited treatment for condylar hyperplasia in a patient with facial asymmetry

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Diego Fernando López

Full Text Available ABSTRACT Condylar Hyperplasia (CH is a self-limiting pathology condition that produces severe facial deformity at the expense of mandibular asymmetry. In this case report a 15-year-old female patient was diagnosed with Unilateral Condylar Hiperplasia (UCH by mean of single-photon emission computed tomography (SPECT and histological study. A high condylectomy in the right condyle was performed to stop the active status of the hyperplasia. A month after condylectomy, orthognathic jaw impaction and asymmetric mandibular setback surgery was performed with the Surgery First Approach (SFA. After 10 days, orthodontic appointments were made every two weeks during 4 months. The active phase of treatment lasted 14 months. Excellent facial and occlusal outcomes were obtained and after 24 months in retention the results remained stable.

JACoW ADAPOS: An architecture for publishing ALICE DCS conditions data

CERN Document Server

Lång, John; Bond, Peter; Chochula, Peter; Kurepin, Alexander; Lechman, Mateusz; Pinazza, Ombretta

2018-01-01

ALICE Data Point Service (ADAPOS) is a software architecture being developed for the RUN3 period of LHC, as a part of the effort to transmit conditions data from ALICE Detector Control System (DCS) to Event Processing Network (EPN), for distributed processing. The key processes of ADAPOS, Engine and Terminal, run on separate machines, facing different networks. Devices connected to DCS publish their state as DIM services. Engine gets updates to the services, and converts them into a binary stream. Terminal receives it over 0MQ, and maintains an image of the DCS state. It sends copies of the image, at regular intervals, over another 0MQ connection, to a readout process of ALICE Data Acquisition.

The Immunomodulatory Potential of tolDCs Loaded with Heat Shock Proteins

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Willem van Eden

2017-11-01

Full Text Available Disease suppressive T cell regulation may depend on cognate interactions of regulatory T cells with self-antigens that are abundantly expressed in the inflamed tissues. Heat shock proteins (HSPs are by their nature upregulated in stressed cells and therefore abundantly present as potential targets for such regulation. HSP immunizations have led to inhibition of experimentally induced inflammatory conditions in various models. However, re-establishment of tolerance in the presence of an ongoing inflammatory process has remained challenging. Since tolerogenic DCs (tolDCs have the combined capacity of mitigating antigen-specific inflammatory responses and of endowing T cells with regulatory potential, it seems attractive to combine the anti-inflammatory qualities of tolDCs with those of HSPs.

The effects of tDCS upon sustained visual attention are dependent on cognitive load.

Science.gov (United States)

Roe, James M; Nesheim, Mathias; Mathiesen, Nina C; Moberget, Torgeir; Alnæs, Dag; Sneve, Markus H

2016-01-08

Transcranial Direct Current Stimulation (tDCS) modulates the excitability of neuronal responses and consequently can affect performance on a variety of cognitive tasks. However, the interaction between cognitive load and the effects of tDCS is currently not well-understood. We recorded the performance accuracy of participants on a bilateral multiple object tracking task while undergoing bilateral stimulation assumed to enhance (anodal) and decrease (cathodal) neuronal excitability. Stimulation was applied to the posterior parietal cortex (PPC), a region inferred to be at the centre of an attentional tracking network that shows load-dependent activation. 34 participants underwent three separate stimulation conditions across three days. Each subject received (1) left cathodal / right anodal PPC tDCS, (2) left anodal / right cathodal PPC tDCS, and (3) sham tDCS. The number of targets-to-be-tracked was also manipulated, giving a low (one target per visual field), medium (two targets per visual field) or high (three targets per visual field) tracking load condition. It was found that tracking performance at high attentional loads was significantly reduced in both stimulation conditions relative to sham, and this was apparent in both visual fields, regardless of the direction of polarity upon the brain's hemispheres. We interpret this as an interaction between cognitive load and tDCS, and suggest that tDCS may degrade attentional performance when cognitive networks become overtaxed and unable to compensate as a result. Systematically varying cognitive load may therefore be a fruitful direction to elucidate the effects of tDCS upon cognitive functions. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Accuracy of pedicle screw placement in patients with Marfan syndrome.

Science.gov (United States)

Qiao, Jun; Zhu, Feng; Xu, Leilei; Liu, Zhen; Sun, Xu; Qian, Bangping; Jiang, Qing; Zhu, Zezhang; Qiu, Yong

2017-03-21

There is no study concerning safety and accuracy of pedicle screw placement in Marfan syndrome. The objective of this study is to investigate accuracy and safety of pedicle screw placement in scoliosis associated with Marfan syndrome. CT scanning was performed to analyze accuracy of pedicle screw placement. Pedicle perforations were classified as medial, lateral or anterior and categorized to four grades: ≤ 2 mm as Grade 1, 2.1-4.0 mm as Grade 2, 4.1-6.0 mm as Grade 3, ≥6.1 mm as Grade 4. Fully contained screws or with medial wall perforation ≤ 2 mm or with lateral wall perforation ≤ 6 mm and without injury of visceral organs were considered acceptable, otherwise were unacceptable. 976 pedicle screws were placed, 713 screws (73.1%) were fully contained within the cortical boundaries of the pedicle. 924 (94.7%) screws were considered as acceptable, and 52 (5.3%) as unacceptable. The perforation rate was higher using free-hand technique than O-arm navigation technique (30.8% VS. 11.4%, P Marfan syndrome is accuracy and safe. O-arm navigation was an effective modality to ensure the safety and accuracy of screw placement. Special attention should be paid when screws were placed at the lumber spine and the concave side of spine deformity to avoid the higher rate of complications.

LILRB4 Decrease on uDCs Exacerbate Abnormal Pregnancy Outcomes Following Toxoplasma gondii Infection

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Shaowei Zhan

2018-03-01

Full Text Available Toxoplasma gondii (T. gondii infection in early pregnancy can result in miscarriage, dead fetus, and other abnormalities. The LILRB4 is a central inhibitory receptor in uterine dendritic cells (uDCs that plays essential immune-regulatory roles at the maternal–fetal interface. In this study, T. gondii-infected human primary uDCs and T. gondii-infected LILRB4-/- pregnant mice were utilized. The immune mechanisms underlying the role of LILRB4 on uDCs were explored in the development of abnormal pregnancy outcomes following T. gondii infection in vitro and in vivo. Our results showed that the expression levels of LILRB4 on uDCs from normal pregnant mice were obviously higher than non-pregnant mice, and peaked in mid-gestation. The LILRB4 expression on uDC subsets, especially tolerogenic subsets, from mid-gestation was obviously down-regulated after T. gondii infection and LILRB4 decrease could further regulate the expression of functional molecules (CD80, CD86, and HLA-DR or MHC II on uDCs, contributing to abnormal pregnancy outcomes. Our results will shed light on the molecular immune mechanisms of uDCs in abnormal pregnancy outcomes by T. gondii infection.

Process and remote device for unscrewing and extracting an assembly screw

International Nuclear Information System (INIS)

Lagarrigue, F.

1990-01-01

The device comprises a C-shaped frame, with two parallel arms and a joining section fixed at one end of a long support, an extraction screw engaged in a hole through one arm and having one end made of a centre punch directed towards the inside of the frame and a remote mean for screwed or unscrewed the extraction screw. A supporting and centering piece can also be fixed to the second branch of the frame. The screw is extracted by exerting a moment about the axis of the screw through the support and frame after tightening the extraction screw. This device can be used particularly for the unscrewing and the extraction of the screw of the springs of a nuclear fuel assembly [fr

Stress and stability of plate-screw fixation and screw fixation in the treatment of Schatzker type IV medial tibial plateau fracture: a comparative finite element study.

Science.gov (United States)

Huang, Xiaowei; Zhi, Zhongzheng; Yu, Baoqing; Chen, Fancheng

2015-11-25

The purpose of this study is to compare the stress and stability of plate-screw fixation and screw fixation in the treatment of Schatzker type IV medial tibial plateau fracture. A three-dimensional (3D) finite element model of the medial tibial plateau fracture (Schatzker type IV fracture) was created. An axial force of 2500 N with a distribution of 60% to the medial compartment was applied to simulate the axial compressive load on an adult knee during single-limb stance. The equivalent von Mises stress, displacement of the model relative to the distal tibia, and displacement of the implants were used as the output measures. The mean stress value of the plate-screw fixation system was 18.78 MPa, which was significantly (P stress value of the triangular fragment in the plate-screw fixation system model was 42.04 MPa, which was higher than that in the screw fixation model (24.18 MPa). But the mean stress of the triangular fractured fragment in the screw fixation model was significantly higher in terms of equivalent von Mises stress (EVMS), x-axis, and z-axis (P < 0.001). This study demonstrated that the load transmission mechanism between plate-screw fixation system and screw fixation system was different and the stability provided by the plate-screw fixation system was superior to the screw fixation system.

Augmentation of Fear Extinction by Transcranial Direct Current Stimulation (tDCS

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Natalie Dittert

2018-04-01

Full Text Available Although posttraumatic stress disorder (PTSD; DSM-V 309.82 and anxiety disorders (DSM-V 300.xx are widely spread mental disorders, the effectiveness of their therapy is still unsatisfying. Non-invasive brain-stimulation techniques like transcranial direct current stimulation (tDCS might be an option to improve extinction learning, which is a main functional factor of exposure-based therapy for anxiety disorders. To examine this hypothesis, we used a fear conditioning paradigm with female faces as conditioned stimuli (CS and a 95-dB female scream as unconditioned stimulus (UCS. We aimed to perform a tDCS of the ventromedial prefrontal cortex (vmPFC, which is mainly involved in the control of extinction-processes. Therefore, we applied two 4 × 4 cm electrodes approximately at the EEG-positions F7 and F8 and used a direct current of 1.5 mA. The 20-min stimulation was started during a 10-min break between acquisition and extinction and went on overall extinction-trials. The healthy participants were randomly assigned in two double-blinded process into two sham stimulation and two verum stimulation groups with opposite current flow directions. To measure the fear reactions, we used skin conductance responses (SCR and subjective ratings. We performed a generalized estimating equations model for the SCR to assess the impact of tDCS and current flow direction on extinction processes for all subjects that showed a successful conditioning (N = 84. The results indicate that tDCS accelerates early extinction processes with a significantly faster loss of CS+/CS– discrimination. The discrimination loss was driven by a significant decrease in reaction toward the CS+ as well as an increase in reaction toward the CS– in the tDCS verum groups, whereas the sham groups showed no significant reaction changes during this period. Therefore, we assume that tDCS of the vmPFC can be used to enhance early extinction processes successfully. But before it should be

BIOMECHANICAL EVALUATION OF THE INFLUENCE OF CERVICAL SCREWS TAPPING AND DESIGN.

Science.gov (United States)

Silva, Patricia; Rosa, Rodrigo César; Shimano, Antonio Carlos; Albuquerque de Paula, Francisco José; Volpon, José Batista; Aparecido Defino, Helton Luiz

2009-01-01

To assess if the screw design (self-drilling/self-tapping) and the pilot hole tapping could affect the insertion torque and screw pullout strength of the screw used in anterior fixation of the cervical spine. Forty self-tapping screws and 20 self-drilling screws were inserted into 10 models of artificial bone and 10 cervical vertebrae of sheep. The studied parameters were the insertion torque and pullout strength. The following groups were created: Group I-self-tapping screw insertion after pilot hole drilling and tapping; Group II-self-tapping screw insertion after pilot hole drilling without tapping; Group III-self-drilling screw insertion without drilling and tapping. In Groups I and II, the pilot hole had 14.0 mm in depth and was made with a 3mmn drill, while tapping was made with a 4mm tap. The insertion torque was measured and the pullout test was performed. The comparison between groups was made considering the mean insertion torque and the maximum mean pullout strength with the variance analysis (ANOVA; p≤ 0.05). Previous drilling and tapping of pilot hole significantly decreased the insertion torque and the pullout strength. The insertion torque and pullout strength of self-drilling screws were significantly higher when compared to self-tapping screws inserted after pilot hole tapping.

Anodal tDCS targeting the right orbitofrontal cortex enhances facial expression recognition

Science.gov (United States)

Murphy, Jillian M.; Ridley, Nicole J.; Vercammen, Ans

2015-01-01

The orbitofrontal cortex (OFC) has been implicated in the capacity to accurately recognise facial expressions. The aim of the current study was to determine if anodal transcranial direct current stimulation (tDCS) targeting the right OFC in healthy adults would enhance facial expression recognition, compared with a sham condition. Across two counterbalanced sessions of tDCS (i.e. anodal and sham), 20 undergraduate participants (18 female) completed a facial expression labelling task comprising angry, disgusted, fearful, happy, sad and neutral expressions, and a control (social judgement) task comprising the same expressions. Responses on the labelling task were scored for accuracy, median reaction time and overall efficiency (i.e. combined accuracy and reaction time). Anodal tDCS targeting the right OFC enhanced facial expression recognition, reflected in greater efficiency and speed of recognition across emotions, relative to the sham condition. In contrast, there was no effect of tDCS to responses on the control task. This is the first study to demonstrate that anodal tDCS targeting the right OFC boosts facial expression recognition. This finding provides a solid foundation for future research to examine the efficacy of this technique as a means to treat facial expression recognition deficits, particularly in individuals with OFC damage or dysfunction. PMID:25971602

Posterior cervical spine arthrodesis with laminar screws. A report of two cases

International Nuclear Information System (INIS)

Nakanishi, Kazuo; Tanaka, Masato; Sugimoto, Yoshihisa; Ozaki, Toshifumi

2007-01-01

We performed fixation using laminar screws in 2 patients in whom lateral mass screws, pedicle screws or transarticular screws could not be inserted. One was a 56-year-old woman who had anterior atlantoaxial subluxation (AAS). When a guide wire was inserted using an imaging guide, the hole bled massively. We thought the re-insertion of a guide wire or screw would thus increase the risk of vascular injury, so we used laminar screws. The other case was an 18-year-old man who had a hangman fracture. Preoperative magnetic resonance angiography showed occlusion of the left vertebral artery. A laminar screw was inserted into the patent side (i.e., the right side of C2). Cervical pedicle screws are the most biomechanically stable screws. However, their use carries a high risk of neurovascular complications during screw insertion, because the cervical pedicle is small and is adjacent laterally to the vertebral artery, medially to the spinal cord, and vertically to the nerve roots. Lateral mass screws are also reported to involve a risk of neurovascular injuries. The laminar screw method was thus thought to be useful, since arterial injuries could thus be avoided and it could also be used as a salvage modality for the previous misinsertion. (author)

tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.

Science.gov (United States)

Vanderhasselt, Marie-Anne; De Raedt, Rudi; Brunoni, Andre R; Campanhã, Camila; Baeken, Chris; Remue, Jonathan; Boggio, Paulo S

2013-01-01

Transcranial Direct Current Stimulation (tDCS) is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP) as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation), we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right) prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.

A comparative study of the detectability of TMJ radiographic techniques for artificial mandibular condylar lesions

International Nuclear Information System (INIS)

Jeong, Hee Jeong; Jung, Yeon Hwa; Cho, Bong Hae

1997-01-01

The purpose of this study was to evaluate the detectability of various radiographic techniques for mandibular condylar lesions. Erosive lesion, osteophyte and flattening were formed on the artificial mandibular condyle, and panoramic, transcranial, transorbital radiography, lateral and frontal tomography were taken. The results were as follows; 1. The detectability for erosive lesions was superior in the order of frontal tomography (96%), lateral tomography (78%), transorbital (59%), transcranial (56%) and panoramic (48%) radiography. 2. The location of erosive lesion that showed the highest detectability was the medial third in panoramic, the lateral third in transcranial, the central portion of anteroposterior direction in transorbital, the central portion of mediolateral direction and the posterior third in lateral tomography. Frontal tomography disclosed all erosive lesions except one anterolateral lesion. 3. The detectability of osteophyte was 100% in lateral tomography, 78% in transcranial and 56% in panoramic radiography. 4. For flattening, lateral tomography showed the flattened condyle, but both panoramic and transcranial views showed only decreased bone density without the change of condylar shape.

Modeling and Analyzing the Slipping of the Ball Screw

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Nannan Xu

Full Text Available AbstractThis paper aims to set up the ball systematic slipping model and analyze the slipping characteristics caused by different factors for a ball screw operating at high speeds. To investigate the ball screw slipping mechanism, transformed coordinate system should be established firstly. Then it is used to set up mathematical modeling for the ball slipping caused by the three main reasons and the speed of slipping can be calculated. Later, the influence of the contact angle, helix angle and screw diameter for ball screw slipping will be analyzed according to the ball slipping model and slipping speeds equation and the slipping analysis will be obtained. Finally, curve of slipping analysis and that of mechanical efficiency of the ball screw analysis by Lin are compared, which will indirectly verify the correctness of the slipping model. The slipping model and the curve of slipping analysis established in this paper will provide theory basis for reducing slipping and improving the mechanical efficiency of a ball screw operating at high speeds.

No significant effect of prefrontal tDCS on working memory performance in older adults

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Jonna eNilsson

2015-12-01

Full Text Available Transcranial direct current stimulation (tDCS has been put forward as a non-pharmacological alternative for alleviating cognitive decline in old age. Although results have shown some promise, little is known about the optimal stimulation parameters for modulation in the cognitive domain. In this study, the effects of tDCS over the dorsolateral prefrontal cortex (dlPFC on working memory performance were investigated in thirty older adults. An N-back task assessed working memory before, during and after anodal tDCS at a current strength of 1mA and 2mA, in addition to sham stimulation. The study used a single-blind, cross-over design. The results revealed no significant effect of tDCS on accuracy or response times during or after stimulation, for any of the current strengths. These results suggest that a single session of tDCS over the dlPFC is unlikely to improve working memory, as assessed by an N-back task, in old age.

Molecular and elemental effects underlying the biochemical action of transcranial direct current stimulation (tDCS) in appetite control

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Surowka, Artur D.; Ziomber, Agata; Czyzycki, Mateusz; Migliori, Alessandro; Kasper, Kaja; Szczerbowska-Boruchowska, Magdalena

2018-04-01

Recent studies highlight that obesity may alter the electric activity in brain areas triggering appetite and craving. Transcranial direct current brain stimulation (tDCS) has recently emerged as a safe alternative for treating food addiction via modulating cortical excitability without any high-risk surgical procedure to be utilized. As for anodal-type tDCS (atDCS), we observe increased excitability and spontaneous firing of the cortical neurons, whilst for the cathodal-type tDCS (ctDCS) a significant decrease is induced. Unfortunately, for the method to be fully used in a clinical setting, its biochemical action mechanism must be precisely defined, although it is proposed that molecular remodelling processes play in concert with brain activity changes involving the ions of: Na, Cl, K and Ca. Herein, we proposed for the first time Fourier transform infrared (FTIR) and synchrotron X-ray fluorescence (SRXRF) microprobes for a combined molecular and elemental analysis in the brain areas implicated appetite control, upon experimental treatment by either atDCS or ctDCS. The study, although preliminary, shows that by stimulating the prefrontal cortex in the rats fed high-caloric nutrients, the feeding behavior can be significantly changed, resulting in significantly inhibited appetite. Both, atDCS and ctDCS produced significant molecular changes involving qualitative and structural properties of lipids, whereas atDCS was found with a somewhat more significant effect on protein secondary structure in all the brain areas investigated. Also, tDCS was reported to reduce surface masses of Na, Cl, K, and Ca in almost all brain areas investigated, although the atDCS deemed to have a stronger neuro-modulating effect. Taken together, one can report that tDCS is an effective treatment technique, and its action mechanism in the appetite control seems to involve a variety of lipid-, protein- and metal/non-metal-ion-driven biochemical changes, regardless the current polarization.

Current Concepts in the Mandibular Condyle Fracture Management Part I: Overview of Condylar Fracture

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Kang-Young Choi

2012-07-01

Full Text Available The incidence of condylar fractures is high,but the management of fractures of the mandibularcondyle continues to be controversial. Historically, maxillomandibular fixation, externalfixation, and surgical splints with internal fixation systems were the techniques commonlyused in the treatment of the fractured mandible. Condylar fractures can be extracapsularor intracapsular, undisplaced, deviated, displaced, or dislocated. Treatment depends on theage of the patient, the co-existence of other mandibular or maxillary fractures, whether thecondylar fracture is unilateral or bilateral, the level and displacement of the fracture, thestate of dentition and dental occlusion, and the surgeonnds on the age of the patient, theco-existence of othefrom which it is difficult to recover aesthetically and functionally;anappropriate treatment is required to reconstruct the shape and achieve the function oftheuninjured status. To do this, accurate diagnosis, appropriate reduction and rigid fixation, andcomplication prevention are required. In particular, as mandibular condyle fracture may causelong-term complications such as malocclusion, particularly open bite, reduced posterior facialheight, and facial asymmetry in addition to chronic pain and mobility limitation, great cautionshould be taken. Accordingly, the authors review a general overview of condyle fracture.

Remotely-Supervised Transcranial Direct Current Stimulation (tDCS for Clinical Trials: Guidelines for Technology and Protocols

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Leigh E Charvet

2015-03-01

Full Text Available The effect of transcranial direct current stimulation (tDCS is cumulative. Treatment protocols typically require multiple consecutive sessions spanning weeks or months. However, traveling to clinic for a tDCS session can present an obstacle to subjects and their caregivers. With modified devices and headgear, tDCS treatment can be administered remotely under clinical supervision, potentially enhancing recruitment, throughput, and convenience. Here we propose standards and protocols for clinical trials utilizing remotely-supervised tDCS with the goal of providing safe, reproducible and well-tolerated stimulation therapy outside of the clinic. The recommendations include: 1 training of staff in tDCS treatment and supervision, 2 assessment of the user’s capability to participate in tDCS remotely, 3 ongoing training procedures and materials including assessments of the user and/or caregiver, 4 simple and fail-safe electrode preparation techniques and tDCS headgear, 5 strict dose control for each session, 6 ongoing monitoring to quantify compliance (device preparation, electrode saturation/placement, stimulation protocol, with corresponding corrective steps as required, 7 monitoring for treatment-emergent adverse effects, 8 guidelines for discontinuation of a session and/or study participation including emergency failsafe procedures tailored to the treatment population’s level of need. These guidelines are intended to provide a minimal level of methodological rigor for clinical trials seeking to apply tDCS outside a specialized treatment center. We outline indication-specific applications (Attention Deficit Hyperactivity Disorder, Depression, Multiple Sclerosis, Palliative Care following these recommendations that support a standardized framework for evaluating the tolerability and reproducibility of remote-supervised tDCS that, once established, will allow for translation of tDCS clinical trials to a greater size and range of patient populations.

Dual-tDCS Enhances Online Motor Skill Learning and Long-Term Retention in Chronic Stroke Patients

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Lefebvre, S.; Laloux, P.; Peeters, A.; Desfontaines, P.; Jamart, J.; Vandermeeren, Y.

2013-01-01

Background: Since motor learning is a key component for stroke recovery, enhancing motor skill learning is a crucial challenge for neurorehabilitation. Transcranial direct current stimulation (tDCS) is a promising approach for improving motor learning. The aim of this trial was to test the hypothesis that dual-tDCS applied bilaterally over the primary motor cortices (M1) improves online motor skill learning with the paretic hand and its long-term retention. Methods: Eighteen chronic stroke patients participated in a randomized, cross-over, placebo-controlled, double bind trial. During separate sessions, dual-tDCS or sham dual-tDCS was applied over 30 min while stroke patients learned a complex visuomotor skill with the paretic hand: using a computer mouse to move a pointer along a complex circuit as quickly and accurately as possible. A learning index involving the evolution of the speed/accuracy trade-off was calculated. Performance of the motor skill was measured at baseline, after intervention and 1 week later. Results: After sham dual-tDCS, eight patients showed performance worsening. In contrast, dual-tDCS enhanced the amount and speed of online motor skill learning compared to sham (p dual-tDCS (n = 10) than after sham (n = 3). More importantly, 1 week later, online enhancement under dual-tDCS had translated into superior long-term retention (+44%) compared to sham (+4%). The improvement generalized to a new untrained circuit and to digital dexterity. Conclusion: A single-session of dual-tDCS, applied while stroke patients trained with the paretic hand significantly enhanced online motor skill learning both quantitatively and qualitatively, leading to successful long-term retention and generalization. The combination of motor skill learning and dual-tDCS is promising for improving post-stroke neurorehabilitation. PMID:23316151

Comparative effect of implant-abutment connections, abutment angulations, and screw lengths on preloaded abutment screw using three-dimensional finite element analysis: An in vitro study.

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Kanneganti, Krishna Chaitanya; Vinnakota, Dileep Nag; Pottem, Srinivas Rao; Pulagam, Mahesh

2018-01-01

The purpose of this study is to compare the effect of implant-abutment connections, abutment angulations, and screw lengths on screw loosening (SL) of preloaded abutment using three dimensional (3D) finite element analysis. 3D models of implants (conical connection with hex/trilobed connections), abutments (straight/angulated), abutment screws (short/long), and crown and bone were designed using software Parametric Technology Corporation Creo and assembled to form 8 simulations. After discretization, the contact stresses developed for 150 N vertical and 100 N oblique load applications were analyzed, using ABAQUS. By assessing damage initiation and shortest fatigue load on screw threads, the SL for 2.5, 5, and 10 lakh cyclic loads were estimated, using fe-safe program. The obtained values were compared for influence of connection design, abutment angulation, and screw length. In straight abutment models, conical connection showed more damage (14.3%-72.3%) when compared to trilobe (10.1%-65.73%) at 2.5, 5, and 10 lakh cycles for both vertical and oblique loads, whereas in angulated abutments, trilobe (16.1%-76.9%) demonstrated more damage compared to conical (13.5%-70%). Irrespective of the connection type and abutment angulation, short screws showed more percentage of damage compared to long screws. The present study suggests selecting appropriate implant-abutment connection based on the abutment angulation, as well as preferring long screws with more number of threads for effective preload retention by the screws.

A four lumen screwing device for multiparametric brain monitoring.

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Feuerstein, T H; Langemann, H; Gratzl, O; Mendelowitsch, A

2000-01-01

We describe multiparametric monitoring in severe head trauma using a new screwing device. Our aim was to create a screw which would make the implantation of the probes and thus multiparametric monitoring easier. The new screw allows us to implant 3 probes (microdialysis, Paratrend and an intracranial pressure device) through one burr hole. The screw has four channels, the fourth being for ventricular drainage. We monitored 13 patients with severe head trauma (GCS = 3-8) for up to 7 days. Brain tissue pO2, pCO2, pH, and temperature were measured on-line with the Paratrend 7 machine. The microdialytic parameters glucose, lactate, pyruvate and glutamate were determined semi on-line with a CMA 600 enzymatic analyser. There were no complications in any of the patients that could be ascribed to the screw.

Experiments on screw-pinch plasmas with elongated cross section

International Nuclear Information System (INIS)

Lassing, H.W.

1989-01-01

In this thesis experiments are described carried out with SPICA II, a toroidal screw-pinch plasma device. this device is the last one in a series of plasma machines of the toroidal screw-pinch differing from its predecessor in its race-track shaped section. In devices of the type toroidal screw-pinch stable confinement is possible of plasmas with larger β values than in a tokamak discharge. In a pinch the plasma is screwed up, during the formation, in such a way that in a relatively small volume a plasma is formated with a high pressure. During the screwing up the plasma is heated by shock heating as well as adiabatic compression. With the modified snowplow model the density and temperature after the formation can be calculated, starting from the initial conditions. When all ions arrive into the plasma column, the density in the column is determined by the volume compression. First purpose of the experiments was to find a stable discharge. Subsequently discharges have been made with a high as possible β in order to investigate at which maximum β it is possible to confine screw-pinch plasmas stably. When these had been found, the nature and importance could be investigated of the processes following which the screw-pinch plasma looses its energy. (author), 75 res.; 95 figs.; 8 tabs

Determination of Screw and Nail Withdrawal Resistance of Some Important Wood Species

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Alper Aytekin

2008-04-01

Full Text Available In this study, screw and nail withdrawal resistance of fir (Abies nordmanniana, oak (Quercus robur L. black pine (Pinus nigra Arnold and Stone pine (Pinus pinea L. wood were determined and compared. The data represent the testing of withdrawal resistance of three types of screws as smart, serrated and conventional and common nails. The specimens were prepared according to TS 6094 standards. The dimensions of the specimens were 5x5x15cm and for all of the directions. Moreover, the specimens were conditioned at ambient room temperature and 65±2% relative humidity. The screws and nails were installed according to ASTM-D 1761 standards. Nail dimensions were 2.5mm diameter and 50 mm length, conventional screws were 4x50mm, serrated screws were 4x45mm and smart screws were 4x50mm. Results show that the maximum screw withdrawal resistance value was found in Stone pine for the serrated screw. There were no significant differences between Stone pine and oak regarding screw withdrawal resistance values. Conventional screw yielded the maximum screw withdrawal resistance value in oak, followed by Stone pine, black pine and fir. Oak wood showed the maximum screw withdrawal resistance value for the smart screw, followed by Stone pine, black pine, and fir. Oak wood showed higher nail withdrawal resistances than softwood species. It was also determined that oak shows the maximum nail withdrawal resistance in all types. The nail withdrawal resistances at the longitudinal direction are lower with respect to radial and tangential directions.

Enhancement of Orthodontic Anchor Screw Stability Under Immediate Loading by Ultraviolet Photofunctionalization Technology.

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Takahashi, Maiko; Motoyoshi, Mitsuru; Inaba, Mizuki; Hagiwara, Yoshiyuki; Shimizu, Noriyoshi

Ultraviolet (UV)-mediated photofunctionalization technology is intended to enhance the osseointegration capability of titanium implants. There are concerns about orthodontic anchor screws loosening under immediate loading protocols in adolescent orthodontic treatment. The purpose of this in vivo study was to evaluate the effects of photofunctionalization on the intrabony stability of orthodontic titanium anchor screws and bone-anchor screw contact under immediate loading in growing rats. Custom-made titanium anchor screws (1.4 mm in diameter and 4.0 mm in length) with or without photofunctionalization pretreatment were placed on the proximal epiphysis of the tibial bone in 6-week-old male Sprague-Dawley rats and were loaded immediately after placement. After 2 weeks of loading, the stability of the anchor screws was evaluated using a Periotest device, and the bone-anchor screw contact ratio (BSC) was assessed by a histomorphometric analysis using field-emission scanning electron microscopy. In the unloaded group, Periotest values (PTVs) were ~25 for UV-untreated screws and 13 for UVtreated screws (P < .01), while in the immediate-loading group, PTVs were 28 for UV-untreated screws and 16 for UV-treated screws (P < .05). Significantly less screw mobility was observed in both UV-treated groups regardless of the loading protocol. The BSC was increased ~1.8 fold for UV-treated screws, compared with UV-untreated screws, regardless of the loading protocol. Photofunctionalization enhanced the intrabony stability of orthodontic anchor screws under immediate loading in growing rats by increasing bone-anchor screw contact.

Transcranial direct current stimulation (tDCS) of frontal cortex decreases performance on the WAIS-IV intelligence test.

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Sellers, Kristin K; Mellin, Juliann M; Lustenberger, Caroline M; Boyle, Michael R; Lee, Won Hee; Peterchev, Angel V; Fröhlich, Flavio

2015-09-01

Transcranial direct current stimulation (tDCS) modulates excitability of motor cortex. However, there is conflicting evidence about the efficacy of this non-invasive brain stimulation modality to modulate performance on cognitive tasks. Previous work has tested the effect of tDCS on specific facets of cognition and executive processing. However, no randomized, double-blind, sham-controlled study has looked at the effects of tDCS on a comprehensive battery of cognitive processes. The objective of this study was to test if tDCS had an effect on performance on a comprehensive assay of cognitive processes, a standardized intelligence quotient (IQ) test. The study consisted of two substudies and followed a double-blind, between-subjects, sham-controlled design. In total, 41 healthy adult participants were included in the final analysis. These participants completed the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) as a baseline measure. At least one week later, participants in substudy 1 received either bilateral tDCS (anodes over both F4 and F3, cathode over Cz, 2 mA at each anode for 20 min) or active sham tDCS (2 mA for 40 s), and participants in substudy 2 received either right or left tDCS (anode over either F4 or F3, cathode over Cz, 2 mA for 20 min). In both studies, the WAIS-IV was immediately administered following stimulation to assess for performance differences induced by bilateral and unilateral tDCS. Compared to sham stimulation, right, left, and bilateral tDCS reduced improvement between sessions on Full Scale IQ and the Perceptual Reasoning Index. This demonstration that frontal tDCS selectively degraded improvement on specific metrics of the WAIS-IV raises important questions about the often proposed role of tDCS in cognitive enhancement. Copyright © 2015 Elsevier B.V. All rights reserved.

Probing and Tapping: Are We Inserting Pedicle Screws Correctly?

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Prasad, Vishal; Mesfin, Addisu; Lee, Robert; Reigrut, Julie; Schmidt, John

2016-11-01

Although there are a significant number of research publications on the topic of bone morphology and the strength of bone, the clinical significance of a failed pedicle screw is often revision surgery and the potential for further postoperative complications; especially in elderly patients with osteoporotic bone. The purpose of this report is to quantify the mechanical strength of the foam-screw interface by assessing probe/pilot hole diameter and tap sizes using statistically relevant sample sizes under highly controlled test conditions. The study consisted of two experiments and used up to three different densities of reference-grade polyurethane foam (ASTM 1839), including 0.16, 0.24, and 0.32 g/cm 3 . All screws and rods were provided by K2M Inc. and screws were inserted to a depth of 25 mm. A series of pilot holes, 1.5, 2.2, 2.7, 3.2, 3.7, 4.2, 5.0, and 6.0 mm in diameter were drilled through the entire depth of the material. A 6.5 × 45-mm pedicle screw was inserted and axially pulled from the material (n = 720). A 3.0-mm pilot hole was drilled and tapped with: no tap, 3.5-, 4.5-, 5.5-, and 6.5-mm taps. A 6.5 × 45-mm pedicle screw was inserted and axially pulled from the material (n = 300). The size of the probe/pilot hole had a nonlinear, parabolic effect on pullout strength. This shape suggests an optimum-sized probe hole for a given size pedicle screw. Too large or too small of a probe hole causes a rapid falloff in pullout strength. The tap data demonstrated that not tapping and undertapping by two or three sizes did not significantly alter the pullout strength of the screws. The data showed an exponential falloff of pullout strength when as tap size increased to the diameter of the screw. In the current study, the data show that an ideal pilot hole size half the diameter of the screw is a starting point. Also, that if tapping was necessary, to use a tap two sizes smaller than the screw being implanted. A similar optimum pilot hole or tap size may be

tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.

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Marie-Anne Vanderhasselt

Full Text Available Transcranial Direct Current Stimulation (tDCS is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation, we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.

Economics of water injected air screw compressor systems

OpenAIRE

Madhav, K. V.; Kovacevic, A.

2015-01-01

There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an in...

Adjacent-segment disease after thoracic pedicle screw fixation.

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Agarwal, Nitin; Heary, Robert F; Agarwal, Prateek

2018-03-01

OBJECTIVE Pedicle screw fixation is a technique widely used to treat conditions ranging from spine deformity to fracture stabilization. Pedicle screws have been used traditionally in the lumbar spine; however, they are now being used with increasing frequency in the thoracic spine as a more favorable alternative to hooks, wires, or cables. Although safety concerns, such as the incidence of adjacent-segment disease (ASD) after cervical and lumbar fusions, have been reported, such issues in the thoracic spine have yet to be addressed thoroughly. Here, the authors review the literature on ASD after thoracic pedicle screw fixation and report their own experience specifically involving the use of pedicle screws in the thoracic spine. METHODS Select references from online databases, such as PubMed (provided by the US National Library of Medicine at the National Institutes of Health), were used to survey the literature concerning ASD after thoracic pedicle screw fixation. To include the authors' experience at Rutgers New Jersey Medical School, a retrospective review of a prospectively maintained database was performed to determine the incidence of complications over a 13-year period in 123 consecutive adult patients who underwent thoracic pedicle screw fixation. Children, pregnant or lactating women, and prisoners were excluded from the review. By comparing preoperative and postoperative radiographic images, the occurrence of thoracic ASD and disease within the surgical construct was determined. RESULTS Definitive radiographic fusion was detected in 115 (93.5%) patients. Seven incidences of instrumentation failure and 8 lucencies surrounding the screws were observed. One patient was observed to have ASD of the thoracic spine. The mean follow-up duration was 50 months. CONCLUSIONS This long-term radiographic evaluation revealed the use of pedicle screws for thoracic fixation to be an effective stabilization modality. In particular, ASD seems to be less of a problem in the

tDCS stimulation segregates words in the brain: evidence from aphasia

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Valentina eFiori

2013-06-01

Full Text Available A number of studies have already shown that modulating cortical activity by means of transcranial direct current stimulation (tDCS improves noun or verb naming in aphasic patients. However, it is not yet clear whether these effects are equally obtained through stimulation over the frontal or the temporal regions. In the present study, the same group of aphasic subjects participated in two randomized double-blind experiments involving two intensive language treatments for their noun and verb retrieval difficulties. During each training, each subject was treated with tDCS (20 min., 1mA over the left hemisphere in three different conditions: anodic tDCS over the temporal areas, anodic tDCS over the frontal areas and sham stimulation, while they performed a noun and an action naming tasks. Each experimental condition was run in five consecutive daily sessions over three weeks with 6 days of intersession interval. The order of administration of the two language trainings was randomly assigned to all patients. Overall, with respect to the other two conditions, results showed a significant greater improvement in noun naming after stimulation over the temporal region, while verb naming recovered significantly better after stimulation of the frontal region. These improvements persisted at one month after the end of each treatment suggesting a long-term effect on recovery of the patients’ noun and verb difficulties. These data clearly suggest that the mechanisms of recovery for naming can be segregated coupling tDCS with an intensive language training.

Cerebellar tDCS does not affect performance in the N-back task.

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van Wessel, Brenda W V; Claire Verhage, M; Holland, Peter; Frens, Maarten A; van der Geest, Jos N

2016-01-01

The N-back task is widely used in cognitive research. Furthermore, the cerebellum's role in cognitive processes is becoming more widely recognized. Studies using transcranial direct current stimulation (tDCS) have demonstrated effects of cerebellar stimulation on several cognitive tasks. Therefore, the aim of this study was to investigate the effects of cerebellar tDCS on cognitive performance by using the N-back task. The cerebellum of 12 participants was stimulated during the task. Moreover, the cognitive load was manipulated in N = 2, N = 3, and N = 4. Every participant received three tDCS conditions (anodal, cathodal, and sham) divided over three separated days. It was expected that anodal stimulation would improve performance on the task. Each participant performed 6 repetitions of every load in which correct responses, false alarms, and reaction times were recorded. We found significant differences between the three levels of load in the rate of correct responses and false alarms, indicating that subjects followed the expected pattern of performance for the N-back task. However, no significant differences between the three tDCS conditions were found. Therefore, it was concluded that in this study cognitive performance on the N-back task was not readily influenced by cerebellar tDCS, and any true effects are likely to be small. We discuss several limitations in task design and suggest future experiments to address such issues.

Cerebellar tDCS does not enhance performance in an implicit categorization learning task

NARCIS (Netherlands)

M.C. Verhage (Claire); E. Avila (Eric); M.A. Frens (Maarten); O. Donchin (Opher); J.N. van der Geest (Jos)

2017-01-01

textabstractBackground: Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive electrical stimulation that changes neuronal excitability in a polarity and site-specific manner. In cognitive tasks related to prefrontal and cerebellar learning, cortical tDCS arguably facilitates

Positioning of pedicle screws in adolescent idiopathic scoliosis using electromyography

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Bruno Moreira Gavassi

2015-06-01

Full Text Available OBJECTIVE: To analyze the occurrence of poor positioning of pedicle screws inserted with the aid of intraoperative electromyographic stimulation in the treatment of Adolescent Idiopathic Scoliosis (AIS.METHODS: This is a prospective observational study including all patients undergoing surgical treatment for AIS, between March and December 2013 at a single institution. All procedures were monitored by electromyography of the inserted pedicle screws. The position of the screws was evaluated by assessment of postoperative CT and classified according to the specific AIS classification system.RESULTS: Sixteen patients were included in the study, totalizing 281 instrumented pedicles (17.5 per patient. No patient had any neurological deficit or complaint after surgery. In the axial plane, 195 screws were found in ideal position (69.4% while in the sagittal plane, 226 screws were found in ideal position (80.4%. Considering both the axial and the sagittal planes, it was observed that 59.1% (166/281 of the screws did not violate any cortical wall.CONCLUSION: The use of pedicle screws proved to be a safe technique without causing neurological damage in AIS surgeries, even with the occurrence of poor positioning of some implants.

Preoperative CT planning of screw length in arthroscopic Latarjet.

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Hardy, Alexandre; Gerometta, Antoine; Granger, Benjamin; Massein, Audrey; Casabianca, Laurent; Pascal-Moussellard, Hugues; Loriaut, Philippe

2018-01-01

The Latarjet procedure has shown its efficiency for the treatment of anterior shoulder dislocation. The success of this technique depends on the correct positioning and fusion of the bone block. The length of the screws that fix the bone block can be a problem. They can increase the risk of non-union if too short or be the cause of nerve lesion or soft tissue discomfort if too long. Suprascapular nerve injuries have been reported during shoulder stabilisation surgery up to 6 % of the case. Bone block non-union depending on the series is found around 20 % of the cases. The purpose of this study was to evaluate the efficiency of this CT preoperative planning to predict optimal screws length. The clinical importance of this study lies in the observation that it is the first study to evaluate the efficiency of CT planning to predict screw length. Inclusion criteria were patients with chronic anterior instability of the shoulder with an ISIS superior to 4. Exclusion criteria were patients with multidirectional instability or any previous surgery on this shoulder. Thirty patients were included prospectively, 11 of them went threw a CT planning, before their arthroscopic Latarjet. Optimal length of both screws was calculated, adding the size of the coracoid at 5 and 15 mm from the tip to the glenoid. Thirty-two-mm screws were used for patients without planning. On a post-operative CT scan with 3D reconstruction, the distance between the screw tip and the posterior cortex was measured. A one-sample Wilcoxon test was used to compare the distance from the tip of the screw to an acceptable positioning of ±2 mm from the posterior cortex. In the group without planning, screw 1 tended to differ from the acceptable positioning: mean 3.44 mm ± 3.13, med 2.9 mm, q1; q3 [0.6; 4.75] p = 0.1118, and screw 2 differed significantly from the acceptable position: mean 4.83 mm ± 4.11, med 3.7 mm, q1; q3 [1.7; 5.45] p = 0.0045. In the group with planning, position of

Transcranial direct current stimulation (tDCS) to the supplementary motor area (SMA) influences performance on motor tasks.

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Hupfeld, K E; Ketcham, C J; Schneider, H D

2017-03-01

The supplementary motor area (SMA) is believed to be highly involved in the planning and execution of both simple and complex motor tasks. This study aimed to examine the role of the SMA in planning the movements required to complete reaction time, balance, and pegboard tasks using anodal transcranial direct current stimulation (tDCS), which passes a weak electrical current between two electrodes, in order to modulate neuronal activity. Twenty healthy adults were counterbalanced to receive either tDCS (experimental condition) or no tDCS (control condition) for 3 days. During administration of tDCS, participants performed a balance task significantly faster than controls. After tDCS, subjects significantly improved their simple and choice reaction time. These results demonstrate that the SMA is highly involved in planning and executing fine and gross motor skill tasks and that tDCS is an effective modality for increasing SMA-related performance on these tasks. The findings may be generalizable and therefore indicate implications for future interventions using tDCS as a therapeutic tool.

Neonatal plasmacytoid dendritic cells (pDCs display subset variation but can elicit potent anti-viral innate responses.

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Xiaoming Zhang

Full Text Available Neonates are highly susceptible to infectious diseases and defective antiviral pDC immune responses have been proposed to contribute to this phenomenon. Isolated cord blood pDCs innately responded to a variety of TLR7 and TLR9 dependent viruses, including influenza A virus (IAV, human immunodeficiency virus (HIV or herpes-simplex virus (HSV by efficiently producing IFN-α, TNF-α as well as chemokines. Interestingly, following activation by CpGA, but not viruses, cord pDCs tend to survive less efficiently. We found that a hallmark of pDCs in neonates is an extended CD2+pDCs compartment compared to adult pDCs without affecting the antiviral IFN-α response. Within CD2+pDCs, we identified a subpopulation expressing CD5 and responsible for IL-12p40 production, however this population is significantly decreased in cord blood compared to adult blood. Therefore, neonatal pDCs clearly display variation in phenotype and subset composition, but without major consequences for their antiviral responses.

Study on pedicle screw fixation of cervical spine assisted CT-based navigation system compared with the individual cervical peddle screws placement technique

International Nuclear Information System (INIS)

He Xishun; Yang Huilin; Zhu Ruofu; Tan Xiangqi; Wang Genlin; Tang Tiansi

2008-01-01

Objective: To explore a safe and effective method for placing the cervical pedicle screws. Methods: There were ten adult cadaver specimens of cervica spine (C 1 -C 7 ) with intact structures including ligament and perivertebral muscles. The spiral computed tomography scan (Elscint CT Twin flash) at the section of 1 mm and three-dimensional reconstruction of all 10 cervical specimens were taken. By CT scan, the parameters of the cervical pedicles were measure,Then taking randomly 5 cervical specimens, according to the CT measurements, an appropriate screw was inserted into pedicle individually. In the other 5 human cadaver cervical vertebraes, Φ3.5 mm screws were inserted into the C 2 -C 7 pedicles by assisted by CT-based navigation system. Cortical integrity of every sample was examined by anatomic dissection, the spiral computed tomography scan and arrows,and coronal reconstruction. Results: Sixty screws was inserted into pedicle individually, and the achievement ratio was 90%, the perfectness ratio was 75%, 60 screws was placed into pedicle assisted by CT-based navigation system, and the achievement ratio was 96.6%, the perfectness ratio was 90%. By chi-square test for statistical analysis, there were no statistical significance between the accuracy rate of two methods(P>0.05). However there was statistical significance between the perfectness ratio between two methods(P<0.05). Conclusion: Compared with the individual cervical peddle screws placement technique, the perfectness ratio of pedicle screw fixation of cervical spine assisted by CT-based navigation system is higher, but there are no significant difference in accuracy. (authors)

[Clinical efficacy of unilateral percutaneous transfacet screws combined with contralateral pedicle screw versus bilateral pedicle screws fixation in the treatment of the degenerative lumbar disease].

Science.gov (United States)

Hao, Rong-Xue; Zhou, Hui; Pan, Hao; Yue, Jun; Chen, Hui-Guo; Yang, He-Jie; Jia, Gao-Yong; Wang, Dong; Lin, Yan; Xu, Hua-Zi

2017-09-25

To investigate the surgical outcome of unilateral pedicle screw(UPS) after TLIF technique combined with contralateral percutaneous transfacet screw(PTS) fixation vs bilateral pedicle screws(BPS) fixation in treatment of degenerative lumbar disease. From January 2009 to June 2012, 46 patients with degenerative lumbar diseases, including 30 males and 16 females with an average age of 51.5 years old, who were divided into two groups according to different fixation methods. Twenty-two cases underwent UPS after TLIF technique combined with contralateral PTS fixation (group A), while the others underwent BPS fixation(group B). The relative data were analyzed, such as blood loss volume, operative time, fusion rate, ODI score, JOA score and so on. All the patients were followed up for 1 to 3 years with an average of 22 months. Except one case of each group was uncertainty fusion, the rest have obtained bony fusion, and the fusion rates in group A and B were 95.5% and 95.8%, respectively. No displacement and breakage of screw were found during follow-up. Operative time and blood loss volume in group A were better than of group B( P 0.05). Two approaches had similar clinical outcomes for degenerative lumbar disease with no severe instability. Compared with BPS fixation, the UPS after TLIF technique and contralateral PTS fixation has the advantages of less trauma, shorter operative time and less blood loss, and it is a safe and feasible surgical technique.

Multiaxial pedicle screw designs: static and dynamic mechanical testing.

Science.gov (United States)

Stanford, Ralph Edward; Loefler, Andreas Herman; Stanford, Philip Mark; Walsh, William R

2004-02-15

Randomized investigation of multiaxial pedicle screw mechanical properties. Measure static yield and ultimate strengths, yield stiffness, and fatigue resistance according to an established model. Compare these measured properties with expected loads in vivo. Multiaxial pedicle screws provide surgical versatility, but the complexity of their design may reduce their strength and fatigue resistance. There is no published data on the mechanical properties of such screws. Screws were assembled according to a vertebrectomy model for destructive mechanical testing. Groups of five assemblies were tested in static tension and compression and subject to three cyclical loads. Modes of failure, yield, and ultimate strength, yield stiffness, and cycles to failure were determined for six designs of screw. Static compression yield loads ranged from 217.1 to 388.0 N and yield stiffness from 23.7 to 38.0 N/mm. Cycles to failure ranged from 42 x 10(3) to 4,719 x 10(3) at 75% of static ultimate load. There were significant differences between designs in all modes of testing. Failure occurred at the multiaxial link in static and cyclical compression. Bending yield strengths just exceeded loads expected in vivo. Multiaxial designs had lower static bending yield strength than fixed screw designs. Five out of six multiaxial screw designs achieved one million cycles at 200 N in compression bending. "Ball-in-cup" multiaxial locking mechanisms were vulnerable to fatigue failure. Smooth surfaces and thicker material appeared to be protective against fatigue failure.

Applying anodal tDCS during tango dancing in a patient with Parkinson's disease.

Science.gov (United States)

Kaski, D; Allum, J H; Bronstein, A M; Dominguez, R O

2014-05-07

Gait disturbance in patients with Parkinson's disease remains a therapeutic challenge, given its poor response to levodopa. Dance therapy is of recognised benefit in these patients, particularly partnered dance forms such as the tango. In parallel, non-invasive brain stimulation has begun to show promise for the rehabilitation of patients with Parkinson's disease, although effects on gait, compared to upper limbs, have been less well defined. We applied transcranial direct current stimulation (tDCS) in a 79 year old male patient with moderate Parkinson's disease during tango dancing to assess its effect on trunk motion and balance. The patient performed a total of four dances over two days, two 'tango+tDCS' and two 'tango+sham' in a randomised double-blind fashion. In a separate experimental session we also assessed the isolated effect of tDCS (and sham) on gait without tango dancing. For the dance session, trunk peak velocity during tango was significantly greater during tDCS compared to sham stimulation. In the gait experiments we observed a modest but significant reduction in the time taken to complete the 3m 'timed up and go' and 6m walk, and an increase in overall gait velocity and peak pitch trunk velocity with tDCS compared to sham. Our findings suggest that tDCS may be a useful adjunct to gait rehabilitation for patients with PD, although studies in a larger group of patients are needed to evaluate the therapeutic use of non-invasive brain stimulation during dance therapy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

On Helical Projection and Its Application in Screw Modeling

Directory of Open Access Journals (Sweden)

Riliang Liu

2014-04-01

Full Text Available As helical surfaces, in their many and varied forms, are finding more and more applications in engineering, new approaches to their efficient design and manufacture are desired. To that end, the helical projection method that uses curvilinear projection lines to map a space object to a plane is examined in this paper, focusing on its mathematical model and characteristics in terms of graphical representation of helical objects. A number of interesting projective properties are identified in regard to straight lines, curves, and planes, and then the method is further investigated with respect to screws. The result shows that the helical projection of a cylindrical screw turns out to be a Jordan curve, which is determined by the screw's axial profile and number of flights. Based on the projection theory, a practical approach to the modeling of screws and helical surfaces is proposed and illustrated with examples, and its possible application in screw manufacturing is discussed.

Impact of antipsychotic medication on transcranial direct current stimulation (tDCS) effects in schizophrenia patients.

Science.gov (United States)

Agarwal, Sri Mahavir; Bose, Anushree; Shivakumar, Venkataram; Narayanaswamy, Janardhanan C; Chhabra, Harleen; Kalmady, Sunil V; Varambally, Shivarama; Nitsche, Michael A; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

2016-01-30

Transcranial direct current stimulation (tDCS) has generated interest as a treatment modality for schizophrenia. Dopamine, a critical pathogenetic link in schizophrenia, is also known to influence tDCS effects. We evaluated the influence of antipsychotic drug type (as defined by dopamine D2 receptor affinity) on the impact of tDCS in schizophrenia. DSM-IV-TR-diagnosed schizophrenia patients [N=36] with persistent auditory hallucinations despite adequate antipsychotic treatment were administered add-on tDCS. Patients were divided into three groups based on the antipsychotic's affinity to D2 receptors. An auditory hallucinations score (AHS) was measured using the auditory hallucinations subscale of the Psychotic Symptom Rating Scales (PSYRATS). Add-on tDCS resulted in a significant reduction inAHS. Antipsychotic drug type had a significant effect on AHS reduction. Patients treated with high affinity antipsychotics showed significantly lesser improvement compared to patients on low affinity antipsychotics or a mixture of the two. Furthermore, a significant sex-by-group interaction occurred; type of medication had an impact on tDCS effects only in women. Improvement differences could be due to the larger availability of the dopamine receptor system in patients taking antipsychotics with low D2 affinity. Sex-specific differences suggest potential estrogen-mediated effects. This study reports a first-time observation on the clinical utility of antipsychotic drug type in predicting tDCS effects in schizophrenia. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Accuracy of S2 Alar-Iliac Screw Placement Under Robotic Guidance.

Science.gov (United States)

Laratta, Joseph L; Shillingford, Jamal N; Lombardi, Joseph M; Alrabaa, Rami G; Benkli, Barlas; Fischer, Charla; Lenke, Lawrence G; Lehman, Ronald A

Case series. To determine the safety and feasibility of S2 alar-iliac (S2AI) screw placement under robotic guidance. Similar to standard iliac fixation, S2AI screws aid in achieving fixation across the sacropelvic junction and decreasing S1 screw strain. Fortunately, the S2AI technique minimizes prominent instrumentation and the need for offset connectors to the fusion construct. Herein, we present an analysis of the largest series of robotic-guided S2AI screws in the literature without any significant author conflicts of interest with the robotics industry. Twenty-three consecutive patients who underwent spinopelvic fixation with 46 S2AI screws under robotic guidance were analyzed from 2015 to 2016. Screws were placed by two senior spine surgeons, along with various fellow or resident surgical assistants, using a proprietary robotic guidance system (Renaissance; Mazor Robotics Ltd., Caesara, Israel). Screw position and accuracy was assessed on intraoperative CT O-arm scans and analyzed using three-dimensional interactive viewing and manipulation of the images. The average caudal angle in the sagittal plane was 31.0° ± 10.0°. The average horizontal angle in the axial plane using the posterior superior iliac spine as a reference was 42.8° ± 6.6°. The average S1 screw to S2AI screw angle was 11.3° ± 9.9°. Two violations of the iliac cortex were noted, with an average breach distance of 7.9 ± 4.8 mm. One breach was posterior (2.2%) and one was anterior (2.2%). The overall robotic S2AI screw accuracy rate was 95.7%. There were no intraoperative neurologic, vascular, or visceral complications related to the placement of the S2AI screws. Spinopelvic fixation achieved using a bone-mounted miniature robotic-guided S2AI screw insertion technique is safe and reliable. Despite two breaches, no complications related to the placement of the S2AI screws occurred in this series. Level IV, therapeutic. Copyright © 2017 Scoliosis Research Society. Published by Elsevier

Development and Testing of X-Ray Imaging-Enhanced Poly-L-Lactide Bone Screws.

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Wei-Jen Chang

Full Text Available Nanosized iron oxide particles exhibit osteogenic and radiopaque properties. Thus, iron oxide (Fe3O4 nanoparticles were incorporated into a biodegradable polymer (poly-L-lactic acid, PLLA to fabricate a composite bone screw. This multifunctional, 3D printable bone screw was detectable on X-ray examination. In this study, mechanical tests including three-point bending and ultimate tensile strength were conducted to evaluate the optimal ratio of iron oxide nanoparticles in the PLLA composite. Both injection molding and 3D printing techniques were used to fabricate the PLLA bone screws with and without the iron oxide nanoparticles. The fabricated screws were implanted into the femoral condyles of New Zealand White rabbits. Bone blocks containing the PLLA screws were resected 2 and 4 weeks after surgery. Histologic examination of the surrounding bone and the radiopacity of the iron-oxide-containing PLLA screws were evaluated. Our results indicated that addition of iron oxide nanoparticles at 30% significantly decreased the ultimate tensile stress properties of the PLLA screws. The screws with 20% iron oxide exhibited strong radiopacity compared to the screws fabricated without the iron oxide nanoparticles. Four weeks after surgery, the average bone volume of the iron oxide PLLA composite screws was significantly greater than that of PLLA screws without iron oxide. These findings suggested that biodegradable and X-ray detectable PLLA bone screws can be produced by incorporation of 20% iron oxide nanoparticles. Furthermore, these screws had significantly greater osteogenic capability than the PLLA screws without iron oxide.

Comprehensive evaluation method in application of nuclear DCS product design

International Nuclear Information System (INIS)

Wang Weixin; Zhao Zhemin; Shi Yingbin

2014-01-01

In order to select the best design proposal in short time, the TOPSIS comprehensive evaluation method in the nuclear power plant DCS product design was introduced. It can intuitively show the different design proposals good or not good by data and shorten the time of the design proposal optimization. The design proposal selected by this method will be more reasonable and has good comprehensive performance indexes. The TOPSIS comprehensive evaluation method achieves good result in one of the nuclear power plant DCS cabinet design proposal optimization. (authors)

Biomechanical properties of a novel biodegradable magnesium-based interference screw

Directory of Open Access Journals (Sweden)

Marco Ezechieli

2016-06-01

Full Text Available Magnesium-based interference screws may be an alternative in anterior/posterior cruciate ligament reconstruction. The well-known osteoconductive effects of biodegradable magnesium alloys may be useful. It was the purpose of this study to evaluate the biomechanical properties of a magnesium based interference screw and compare it to a standard implant. A MgYREZr-alloy interference screw and a standard implant (Milagro®; De Puy Mitek, Raynham, MA, USA were used for graft fixation. Specimens were placed into a tensile loading fixation of a servohydraulic testing machine. Biomechanical analysis included pretensioning of the constructs at 20 N for 1 min following cyclic pretensioning of 20 cycles between 20 and 60 N. Biomechanical elongation was evaluated with cyclic loading of 1000 cycles between 50 and 200 N at 0.5 Hz. Maximum load to failure was 511.3±66.5 N for the Milagro® screw and 529.0±63.3 N for magnesium-based screw (ns, P=0.57. Elongations after preload, during cyclical loading and during failure load were not different between the groups (ns, P>0.05. Stiffness was 121.1±13.8 N/mm for the magnesiumbased screw and 144.1±18.4 for the Milagro® screw (ns, P=0.32. MgYREZr alloy interference screws show comparable results in biomechanical testing to standard implants and may be an alternative for anterior cruciate reconstruction in the future.

Evaluation of occupational and patient radiation doses in orthopedic surgery

International Nuclear Information System (INIS)

Sulieman, A.; Alzimami, K.; Habeeballa, B.; Osman, H.; Abdelaziz, I.; Sassi, S.A.; Sam, A.K.

2015-01-01

This study intends to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (DHS) and (ii) Dynamic Cannula Screw (DCS) and to evaluate entrance surface Air kerma (ESAK) dose and organ doses and effective doses. Calibrated Thermoluminescence dosimeters (TLD-GR200A) were used. The mean patients’ doses were 0.46 mGy and 0.07 mGy for DHS and DCS procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean organ and effective dose for patients and staff were higher in DHS compared to DCS. Orthopedic surgeons were exposed to unnecessary radiation doses due to the lack of protection measures. The radiation dose per hip procedure is within the safety limit and less than the previous studies

Transcranial Direct Current Stimulation and Power Spectral Parameters: a tDCS/EEG co-registration study

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Anna Lisa Mangia

2014-08-01

Full Text Available Transcranial direct current stimulation (tDCS delivers low electric currents to the brain through the scalp. Constant electric currents induce shifts in neuronal membrane excitability, resulting in secondary changes in cortical activity. Concomitant electroencephalography (EEG monitoring during tDCS can provide valuable information on the tDCS mechanisms of action. This study examined the effects of anodal tDCS on spontaneous cortical activity in a resting brain to disclose possible modulation of spontaneous oscillatory brain activity. EEG activity was measured in ten healthy subjects during and after a session of anodal stimulation of the postero-parietal cortex to detect the tDCS-induced alterations. Changes in the theta, alpha, beta and gamma power bands were investigated. Three main findings emerged: 1 an increase in theta band activity during the first minutes of stimulation; 2 an increase in alpha and beta power during and after stimulation; 3 a widespread activation in several brain regions.

Increased contextual cue utilization with tDCS over the prefrontal cortex during a recognition task

Science.gov (United States)

Pergolizzi, Denise; Chua, Elizabeth F.

2016-01-01

The precise role of the prefrontal and posterior parietal cortices in recognition performance remains controversial, with questions about whether these regions contribute to recognition via the availability of mnemonic evidence or via decision biases and retrieval orientation. Here we used an explicit memory cueing paradigm, whereby external cues probabilistically predict upcoming memoranda as old or new, in our case with 75% validity, and these cues affect recognition decision biases in the direction of the cue. The present study applied bilateral transcranial direct current stimulation (tDCS) over prefrontal or posterior parietal cortex, or sham tDCS, to test the causal role of these regions in recognition accuracy or decision biasing. Participants who received tDCS over prefrontal cortex showed increased cue utilization compared to tDCS over posterior parietal cortex and sham tDCS, suggesting that the prefrontal cortex is involved in processes that contribute to decision biases in memory. PMID:27845032

Motor/Prefrontal Transcranial Direct Current Stimulation (tDCS) Following Lumbar Surgery Reduces Postoperative Analgesia Use.

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Glaser, John; Reeves, Scott T; Stoll, William David; Epperson, Thomas I; Hilbert, Megan; Madan, Alok; George, Mark S; Borckardt, Jeffrey J

2016-05-01

Randomized, controlled pilot trial. The present study is the first randomized, double-blind, sham-controlled pilot clinical trial of transcranial direct current stimulation (tDCS) for pain and patient-controlled analgesia (PCA) opioid usage among patients receiving spine surgery. Lumbar spinal surgeries are common, and while pain is often a complaint that precedes surgical intervention, the procedures themselves are associated with considerable postoperative pain lasting days to weeks. Adequate postoperative pain control is an important factor in determining recovery and new analgesic strategies are needed that can be used adjunctively to existing strategies potentially to reduce reliance on opioid analgesia. Several novel brain stimulation technologies including tDCS are beginning to demonstrate promise as treatments for a variety of pain conditions. Twenty-seven patients undergoing lumbar spine procedures at Medical University of South Carolina were randomly assigned to receive four 20-minute sessions of real or sham tDCS during their postsurgical hospital stay. Patient-administered hydromorphone usage was tracked along with numeric rating scale pain ratings. The effect of tDCS on the slope of the cumulative PCA curve was significant (P tDCS was associated with a 23% reduction in PCA usage. In the real tDCS group a 31% reduction was observed in pain-at-its-least ratings from admission to discharge (P = 0.027), but no other changes in numeric rating scale pain ratings were significant in either group. The present pilot trial is the first study to demonstrate an opioid sparing effect of tDCS after spine surgical procedures. Although this was a small pilot trial in a heterogeneous sample of spinal surgery patients, a moderate effect-size was observed for tDCS, suggesting that future work in this area is warranted. 2.

Imaging transcranial direct current stimulation (tDCS) of the prefrontal cortex-correlation or causality in stimulation-mediated effects?

Science.gov (United States)

Wörsching, Jana; Padberg, Frank; Ertl-Wagner, Birgit; Kumpf, Ulrike; Kirsch, Beatrice; Keeser, Daniel

2016-10-01

Transcranial current stimulation approaches include neurophysiologically distinct non-invasive brain stimulation techniques widely applied in basic, translational and clinical research: transcranial direct current stimulation (tDCS), oscillating transcranial direct current stimulation (otDCS), transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS). Prefrontal tDCS seems to be an especially promising tool for clinical practice. In order to effectively modulate relevant neural circuits, systematic research on prefrontal tDCS is needed that uses neuroimaging and neurophysiology measures to specifically target and adjust this method to physiological requirements. This review therefore analyses the various neuroimaging methods used in combination with prefrontal tDCS in healthy and psychiatric populations. First, we provide a systematic overview on applications, computational models and studies combining neuroimaging or neurophysiological measures with tDCS. Second, we categorise these studies in terms of their experimental designs and show that many studies do not vary the experimental conditions to the extent required to demonstrate specific relations between tDCS and its behavioural or neurophysiological effects. Finally, to support best-practice tDCS research we provide a methodological framework for orientation among experimental designs. Copyright © 2016 Elsevier Ltd. All rights reserved.

DCS-Neural-Network Program for Aircraft Control and Testing

Science.gov (United States)

Jorgensen, Charles C.

2006-01-01

A computer program implements a dynamic-cell-structure (DCS) artificial neural network that can perform such tasks as learning selected aerodynamic characteristics of an airplane from wind-tunnel test data and computing real-time stability and control derivatives of the airplane for use in feedback linearized control. A DCS neural network is one of several types of neural networks that can incorporate additional nodes in order to rapidly learn increasingly complex relationships between inputs and outputs. In the DCS neural network implemented by the present program, the insertion of nodes is based on accumulated error. A competitive Hebbian learning rule (a supervised-learning rule in which connection weights are adjusted to minimize differences between actual and desired outputs for training examples) is used. A Kohonen-style learning rule (derived from a relatively simple training algorithm, implements a Delaunay triangulation layout of neurons) is used to adjust node positions during training. Neighborhood topology determines which nodes are used to estimate new values. The network learns, starting with two nodes, and adds new nodes sequentially in locations chosen to maximize reductions in global error. At any given time during learning, the error becomes homogeneously distributed over all nodes.

Transcranial Direct Current Stimulation (tDCS: A Beginner's Guide for Design and Implementation

Directory of Open Access Journals (Sweden)

Hayley Thair

2017-11-01

Full Text Available Transcranial direct current stimulation (tDCS is a popular brain stimulation method that is used to modulate cortical excitability, producing facilitatory or inhibitory effects upon a variety of behaviors. There is, however, a current lack of consensus between studies, with many results suggesting that polarity-specific effects are difficult to obtain. This article explores some of these differences and highlights the experimental parameters that may underlie their occurrence. We provide a general, practical snapshot of tDCS methodology, including what it is used for, how to use it, and considerations for designing an effective and safe experiment. Our aim is to equip researchers who are new to tDCS with the essential knowledge so that they can make informed and well-rounded decisions when designing and running successful experiments. By summarizing the varied approaches, stimulation parameters, and outcomes, this article should help inform future tDCS research in a variety of fields.

Transcranial Direct Current Stimulation (tDCS): A Beginner's Guide for Design and Implementation

Science.gov (United States)

Thair, Hayley; Holloway, Amy L.; Newport, Roger; Smith, Alastair D.

2017-01-01

Transcranial direct current stimulation (tDCS) is a popular brain stimulation method that is used to modulate cortical excitability, producing facilitatory or inhibitory effects upon a variety of behaviors. There is, however, a current lack of consensus between studies, with many results suggesting that polarity-specific effects are difficult to obtain. This article explores some of these differences and highlights the experimental parameters that may underlie their occurrence. We provide a general, practical snapshot of tDCS methodology, including what it is used for, how to use it, and considerations for designing an effective and safe experiment. Our aim is to equip researchers who are new to tDCS with the essential knowledge so that they can make informed and well-rounded decisions when designing and running successful experiments. By summarizing the varied approaches, stimulation parameters, and outcomes, this article should help inform future tDCS research in a variety of fields. PMID:29213226

Effects on Subtalar Joint Stress Distribution After Cannulated Screw Insertion at Different Positions and Directions.

Science.gov (United States)

Yuan, Cheng-song; Chen, Wan; Chen, Chen; Yang, Guang-hua; Hu, Chao; Tang, Kang-lai

2015-01-01

We investigated the effects on subtalar joint stress distribution after cannulated screw insertion at different positions and directions. After establishing a 3-dimensional geometric model of a normal subtalar joint, we analyzed the most ideal cannulated screw insertion position and approach for subtalar joint stress distribution and compared the differences in loading stress, antirotary strength, and anti-inversion/eversion strength among lateral-medial antiparallel screw insertion, traditional screw insertion, and ideal cannulated screw insertion. The screw insertion approach allowing the most uniform subtalar joint loading stress distribution was lateral screw insertion near the border of the talar neck plus medial screw insertion close to the ankle joint. For stress distribution uniformity, antirotary strength, and anti-inversion/eversion strength, lateral-medial antiparallel screw insertion was superior to traditional double-screw insertion. Compared with ideal cannulated screw insertion, slightly poorer stress distribution uniformity and better antirotary strength and anti-inversion/eversion strength were observed for lateral-medial antiparallel screw insertion. Traditional single-screw insertion was better than double-screw insertion for stress distribution uniformity but worse for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion was slightly worse for stress distribution uniformity than was ideal cannulated screw insertion but superior to traditional screw insertion. It was better than both ideal cannulated screw insertion and traditional screw insertion for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion is an approach with simple localization, convenient operation, and good safety. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Electromagnetic Lead Screw for Potential Wave Energy Application

DEFF Research Database (Denmark)

Lu, Kaiyuan; Wu, Weimin

2014-01-01

This paper presents a new type electromagnetic lead screw (EMLS) intended for wave energy application. Similar to the mechanical lead screw, this electromagnetic version can transfer slow linear motion to high-rotational motion, offering gearing effects. Compared with the existing pure magnetic...

Modulation of Brain Activity with Noninvasive Transcranial Direct Current Stimulation (tDCS): Clinical Applications and Safety Concerns

Science.gov (United States)

Zhao, Haichao; Qiao, Lei; Fan, Dongqiong; Zhang, Shuyue; Turel, Ofir; Li, Yonghui; Li, Jun; Xue, Gui; Chen, Antao; He, Qinghua

2017-01-01

Transcranial direct current stimulation (tDCS) is a widely-used tool to induce neuroplasticity and modulate cortical function by applying weak direct current over the scalp. In this review, we first introduce the underlying mechanism of action, the brief history from discovery to clinical scientific research, electrode positioning and montages, and parameter setup of tDCS. Then, we review tDCS application in clinical samples including people with drug addiction, major depression disorder, Alzheimer's disease, as well as in children. This review covers the typical characteristics and the underlying neural mechanisms of tDCS treatment in such studies. This is followed by a discussion of safety, especially when the current intensity is increased or the stimulation duration is prolonged. Given such concerns, we provide detailed suggestions regarding safety procedures for tDCS operation. Lastly, future research directions are discussed. They include foci on the development of multi-tech combination with tDCS such as with TMS and fMRI; long-term behavioral and morphological changes; possible applications in other research domains, and more animal research to deepen the understanding of the biological and physiological mechanisms of tDCS stimulation. PMID:28539894

New Concept For Alarm Structure And Management In Dcs Systems

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Mohammed Hegazy

2015-08-01

Full Text Available The objective of this paper is to set new standard for good design and best practice to applied when any DCS ManufacturesSuppliers configure process alarm system in any oil refining oil and gas production gas-handling facilities gasification plant or any chemical processing plant and thereby to optimizeminimize unnecessary alarms from reporting to operator workstations CAD Control Alarm Display. These views based on the experience acquired and implemented during involvement with the commissioning and startup of two DCS projects in Mina Al-Ahmadi Refinery Kuwait.

A reliability evaluation method for NPP safety DCS application software

International Nuclear Information System (INIS)

Li Yunjian; Zhang Lei; Liu Yuan

2014-01-01

In the field of nuclear power plant (NPP) digital i and c application, reliability evaluation for safety DCS application software is a key obstacle to be removed. In order to quantitatively evaluate reliability of NPP safety DCS application software, this paper propose a reliability evaluating method based on software development life cycle every stage's v and v defects density characteristics, by which the operating reliability level of the software can be predicted before its delivery, and helps to improve the reliability of NPP safety important software. (authors)

Bioresorbable screws reinforced with phosphate glass fibre: manufacturing and mechanical property characterisation.

Science.gov (United States)

Felfel, R M; Ahmed, I; Parsons, A J; Rudd, C D

2013-01-01

Use of bioresorbable screws could eliminate disadvantages associated with metals such as removal operations, corrosion, MRI interference and stress shielding. Mechanical properties of bioresorbable polymers alone are insufficient for load bearing applications application as screws. Thus, reinforcement is necessary to try and match or surpass the mechanical properties of cortical bone. Phosphate based glass fibres were used to reinforce polylactic acid (PLA) in order to produce unidirectionally aligned (UD) and unidirectionally plus randomly distributed (UD/RM) composite screws (P40 UD and P40 UD/RM). The maximum flexural and push-out properties for the composite screws (P40 UD and P40 UD/RM) increased by almost 100% in comparison with the PLA screws. While the pull-out strength and stiffness of the headless composite screws were ∼80% (strength) and ∼130% (stiffness) higher than for PLA, those with heads exhibited properties lower than those for PLA alone as a result of failure at the heads. An increase in the maximum shear load and stiffness for the composite screws (∼30% and ∼40%) in comparison to the PLA screws was also seen. Maximum torque for the PLA screws was ∼1000 mN m, while that for the composite screws were slightly lower. The SEM micrographs for P40 UD and P40 UD/RM screws revealed small gaps around the fibres, which were suggested to be due to buckling of the UD fibres during the manufacturing process. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of prefrontal tDCS on executive function: Methodological considerations revealed by meta-analysis.

Science.gov (United States)

Imburgio, Michael J; Orr, Joseph M

2018-05-01

A meta-analysis of studies using single-session transcranial direct current stimulation (tDCS) to target the dorsolateral prefrontal cortex (DLPFC) was undertaken to examine the effect of stimulation on executive function (EF) in healthy samples. 27 studies were included in analyses, yielding 71 effect sizes. The most relevant measure for each task was determined a priori and used to calculate Hedge's g. Methodological characteristics of each study were examined individually as potential moderators of effect size. Stimulation effects on three domains of EF (inhibition of prepotent responses, mental set shifting, and information updating and monitoring) were analyzed separately. In line with previous work, the current study found no significant effect of anodal unilateral tDCS, cathodal unilateral tDCS, or bilateral tDCS on EF. Further moderator and subgroup analyses were only carried out for anodal unilateral montages due to the small number of studies using other montages. Subgroup analyses revealed a significant effect of anodal unilateral tDCS on updating tasks, but not on inhibition or set-shifting tasks. Cathode location significantly moderated the effect of anodal unilateral tDCS. Extracranial cathodes yielded a significant effect on EF while cranial cathodes yielded no effect. Anode size also significantly moderated effect of anodal unilateral tDCS, with smaller anodes being more effective than larger anodes. In summary, anodal DLPFC stimulation is more effective at improving updating ability than inhibition and set-shifting ability, but anodal stimulation can significantly improve general executive function when extracranial cathodes or small anodes are used. Future meta-analyses may examine how stimulation's effects on specific behavioral tasks, rather than broader domains, might be affected by methodological moderators. Copyright © 2018 Elsevier Ltd. All rights reserved.

Clinical significance of condylar chondromalacia after arthroscopic resection of flap-tears of the medial meniscus. A prospective study of 93 cases.

Science.gov (United States)

Aune, A K; Madsen, J E; Moen, H

1995-01-01

We describe the results after arthroscopic resection of flap-tears of the medial meniscus posterior horn in 93 patients with (40) or without (53) chondromalacia of the adjacent condylar cartilage at the time of operation. These were 93 consecutive patients presenting with medial flap-tears during the period 1988-1990 in our departments. The follow-up averaged 42 (range 26-50) months. There was a significant difference in the functional results at review depending on the presence or absence of condylar chondromalacia at arthroscopy. Among the 40 patients with chondromalacia, the Lysholm score was significantly lower (P chondromalacia with age (P < 0.001). In conclusion, the presence of minor degenerative changes in the articular cartilage adjacent to meniscal flap-tears correlated with a less favourable outcome.

Open versus closed reduction: mandibular condylar fractures in children.

Science.gov (United States)

Chrcanovic, Bruno Ramos

2012-09-01

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of mandibular condylar fractures (MCFs) in children. An electronic search in PubMed was undertaken in May 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies published in English or German from the last 20 years (from 1992 onwards) reporting clinical series of MCFs in children and adolescents until the age of 18. The search strategy initially identified 542 studies. The references from 1992 onwards totaled 339 articles. Twenty-seven studies were identified without repetition within the selection criteria. Additional hand-searching yielded two additional papers. Pediatric MCFs require thoughtful consideration in management to avoid significant growth disturbance. Early treatment is indicated in order to improve the chances for favorable development. Long-term follow-up is required, in order to properly treat late complications that may appear. Coronal computed tomography is helpful in substantiating the correct final diagnosis. Many studies show that conservative treatment (CTR) has satisfactory long-term outcome of jaw function, occlusion, and facial esthetics, despite a high frequency of radiological aberrations. Surgery before puberty should be reserved for exceptional cases such as missile injuries, in cases with extensive dislocation and lack of contact between the fragments, in cases with multiple midfacial fractures, in which the mandible has to serve as a guide to reposition the midfacial bones, and in cases which the dislocation of the fractured stump creates a functional impediment that cannot be resolved by CTR. As the craniofacial skeleton becomes more adult-like in its form at about 12 years of age, the decreased remodeling capacity in the adolescents may occasionally result in abnormally shaped condylar heads or shortened ramus heights that may

Process and apparatus for optimizing screwing position for closure stud

International Nuclear Information System (INIS)

Bourdonne, J.C.; Briand, A.

1987-01-01

The stud is fixed to a screwing and unscrewing device. The vertical position and alignment of the stud with the axis of the threated hole is checking. The stud is descended into the hole and rotated in the unscrewing direction. After detection of the point of engagement, the stud is rotated in the screwing direction. When a gamming is detected the descent is stopped and the screwing device is positioned in a new position. When the screwing couple returns below the disconnection couple, the stud is rotated with a reduced speed and then with a normal speed until the end [fr

Analysis of effect of safety classification on DCS design in nuclear power plants

International Nuclear Information System (INIS)

Gou Guokai; Li Guomin; Wang Qunfeng

2011-01-01

By analyzing the safety classification for the systems and functions of nuclear power plants based on the general design requirements for nuclear power plants, especially the requirement of availability and reliability of I and C systems, the characteristics of modem DCS technology and I and C products currently applied in nuclear power field are interpreted. According to the requirements on the safety operation of nuclear power plants and the regulations for safety audit, the effect of different safety classifications on DCS design in nuclear power plants is analyzed, by considering the actual design process of different DCS solutions in the nuclear power plants under construction. (authors)

Grid deformation strategies for CFD analysis of screw compressors

OpenAIRE

Rane, S.; Kovacevic, A.; Stosic, N.; Kethidi, M.

2013-01-01

Customized grid generation of twin screw machines for CFD analysis is widely used by the refrigeration and air-conditioning industry today, but is currently not suitable for topologies such as those of single screw, variable pitch or tri screw rotors. This paper investigates a technique called key-frame re-meshing that supplies pre-generated unstructured grids to the CFD solver at different time steps. To evaluate its accuracy, the results of an isentropic compression-expansion process in a r...

Building up analgesia in humans via the endogenous μ-opioid system by combining placebo and active tDCS: a preliminary report.

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Marcos F DosSantos

Full Text Available Transcranial Direct Current Stimulation (tDCS is a method of non-invasive brain stimulation that has been frequently used in experimental and clinical pain studies. However, the molecular mechanisms underlying tDCS-mediated pain control, and most important its placebo component, are not completely established. In this pilot study, we investigated in vivo the involvement of the endogenous μ-opioid system in the global tDCS-analgesia experience. Nine healthy volunteers went through positron emission tomography (PET scans with [11C]carfentanil, a selective μ-opioid receptor (MOR radiotracer, to measure the central MOR activity during tDCS in vivo (non-displaceable binding potential, BPND--one of the main analgesic mechanisms in the brain. Placebo and real anodal primary motor cortex (M1/2mA tDCS were delivered sequentially for 20 minutes each during the PET scan. The initial placebo tDCS phase induced a decrease in MOR BPND in the periaqueductal gray matter (PAG, precuneus, and thalamus, indicating activation of endogenous μ-opioid neurotransmission, even before the active tDCS. The subsequent real tDCS also induced MOR activation in the PAG and precuneus, which were positively correlated to the changes observed with placebo tDCS. Nonetheless, real tDCS had an additional MOR activation in the left prefrontal cortex. Although significant changes in the MOR BPND occurred with both placebo and real tDCS, significant analgesic effects, measured by improvements in the heat and cold pain thresholds, were only observed after real tDCS, not the placebo tDCS. This study gives preliminary evidence that the analgesic effects reported with M1-tDCS, can be in part related to the recruitment of the same endogenous MOR mechanisms induced by placebo, and that such effects can be purposely optimized by real tDCS.

Multi-session transcranial direct current stimulation (tDCS elicits inflammatory and regenerative processes in the rat brain.

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Maria Adele Rueger

Full Text Available Transcranial direct current stimulation (tDCS is increasingly being used in human studies as an adjuvant tool to promote recovery of function after stroke. However, its neurobiological effects are still largely unknown. Electric fields are known to influence the migration of various cell types in vitro, but effects in vivo remain to be shown. Hypothesizing that tDCS might elicit the recruitment of cells to the cortex, we here studied the effects of tDCS in the rat brain in vivo. Adult Wistar rats (n = 16 were randomized to either anodal or cathodal stimulation for either 5 or 10 consecutive days (500 µA, 15 min. Bromodeoxyuridine (BrdU was given systemically to label dividing cells throughout the experiment. Immunohistochemical analyses ex vivo included stainings for activated microglia and endogenous neural stem cells (NSC. Multi-session tDCS with the chosen parameters did not cause a cortical lesion. An innate immune response with early upregulation of Iba1-positive activated microglia occurred after both cathodal and anodal tDCS. The involvement of adaptive immunity as assessed by ICAM1-immunoreactivity was less pronounced. Most interestingly, only cathodal tDCS increased the number of endogenous NSC in the stimulated cortex. After 10 days of cathodal stimulation, proliferating NSC increased by ∼60%, with a significant effect of both polarity and number of tDCS sessions on the recruitment of NSC. We demonstrate a pro-inflammatory effect of both cathodal and anodal tDCS, and a polarity-specific migratory effect on endogenous NSC in vivo. Our data suggest that tDCS in human stroke patients might also elicit NSC activation and modulate neuroinflammation.

Locking screw apparatus and method for underwater remote replacement

International Nuclear Information System (INIS)

Balog, L.J.

1987-01-01

A method is described for locking in place a screw which secures together first and second structures in the internal region of a nuclear reactor core. The first structure has a screw bore with a counterbore portion formed in an outer surface. The method comprises the steps of: forming a lateral recess in the counterbore portion and spaced from the outer surface, providing an elongated screw having an enlarged shoulder flange and an angular drive head with a lateral width substantially less than that of the counterbore portion, disposing the screw through the screw bore in threaded engagement with the second structure and with the shoulder rotatably seated in the counterbore portion. This provides a locking member having an angular opening and disposing it in the counterbore portion against the flange with the drive head received in the opening for engagement with the locking member to prevent rotation. This deforms a portion of the locking member into the recess for engagement to prevent movement of the locking member with respect to the first structure

Tests for the dynamic behavior of insulation valve screws

International Nuclear Information System (INIS)

Tulke, K.D.; Stoppler, W.; Stern, G.

1994-01-01

Thermal tensile tests were performed at a temperature of 270 C, with two new original insulation valve conical screws M30-Tx92,5 mm (material: 21 CrMo V 5 7)and two prestrained ones during the event on 27.12.92. In order to assure the results obtained with regard to the dynamic load on the insulation valve during ''quick opening'', in addition tensile impact tests were performed at 270 C with six original insulation valve conical screws. Impact velocity reached 13,5 m/s at four screws and 6 m/s at two screws. Test conditions regarding collision damping and mass distribution were adapted, by means of parameter studies, to the situation of the insulation valve. During thermal tensile tests, strength and deformation values, such as stress at flow start, tensile strength, fracture prolongation and strain, necking at fracture as well as energy absorption up to maximum force and up to rupture, were determined. During tensile impact tests, deformation values, such as elongation, strain and necking, and energy absorption by the screw, were determined. (orig.) [de

Antigen Loading (e.g., Glutamic Acid Decarboxylase 65 of Tolerogenic DCs (tolDCs Reduces Their Capacity to Prevent Diabetes in the Non-Obese Diabetes (NOD-Severe Combined Immunodeficiency Model of Adoptive Cotransfer of Diabetes As Well As in NOD Mice

Directory of Open Access Journals (Sweden)

David P. Funda

2018-02-01

Full Text Available Tolerogenic DCs (tolDCs are being researched as a promising intervention strategy also in autoimmune diseases including type 1 diabetes (T1D. T1D is a T-cell-mediated, organ-specific disease with several well-defined and rather specific autoantigens, i.e., proinsulin, insulin, glutamic acid decarboxylase 65 (GAD65, that have been used in animal as well as human intervention trials in attempts to achieve a more efficient, specific immunotherapy. In this study, we have tested tolerogenic DCs for their effectiveness to prevent adoptive transfer of diabetes by diabetogenic splenocytes into non-obese diabetes (NOD-severe combined immunodeficiency (NOD-SCID recipients. While i.p. application of tolDCs prepared from bone marrow of prediabetic NOD mice by vitamin D2 and dexamethasone significantly reduced diabetes transfer into the NOD-SCID females, this effect was completely abolished when tolDCs were loaded with the mouse recombinant GAD65, but also with a control protein—ovalbumin (OVA. The effect was not dependent on the presence of serum in the tolDC culture. Similar results were observed in NOD mice. Removal of possible bystander antigen-presenting cells within the diabetogenic splenocytes by negative magnetic sorting of T cells did not alter this surprising effect. Tolerogenic DCs loaded with an immunodominant mouse GAD65 peptide also displayed diminished diabetes-preventive effect. Tolerogenic DCs were characterized by surface maturation markers (CD40, CD80, CD86, MHC II and the lipopolysaccharide stability test. Data from alloreactive T cell proliferation and cytokine induction assays (IFN-γ did not reveal the differences observed in the diabetes incidence. Migration of tolDCs, tolDCs-GAD65 and tolDCs-OVA to spleen, mesenteric- and pancreatic lymph nodes displayed similar, mucosal pattern with highest accumulation in pancreatic lymph nodes present up to 9 days after the i.p. application. These data document that mechanisms by which tolDCs

Correction Capability in the 3 Anatomic Planes of Different Pedicle Screw Designs in Scoliosis Instrumentation.

Science.gov (United States)

Wang, Xiaoyu; Aubin, Carl-Eric; Coleman, John; Rawlinson, Jeremy

2017-05-01

Computer simulations to compare the correction capabilities of different pedicle screws in adolescent idiopathic scoliosis (AIS) instrumentations. To compare the correction and resulting bone-screw forces associated with different pedicle screws in scoliosis instrumentations. Pedicle screw fixation is widely used in surgical instrumentation for spinal deformity treatment. Screw design, correction philosophies, and surgical techniques are constantly evolving to achieve better control of the vertebrae and correction of the spinal deformity. Yet, there remains a lack of biomechanical studies that quantify the effects and advantages of different screw designs in terms of correction kinematics. The correction capabilities of fixed-angle, multiaxial, uniaxial, and saddle axial screws were kinematically analyzed, simulated, and compared. These simulations were based on the screw patterns and correction techniques proposed by 2 experienced surgeons for 2 AIS cases. Additional instrumentations were assessed to compare the correction and resulting bone-screw forces associated with each type of screw. The fixed-angle, uniaxial and saddle axial screws had similar kinematic behavior and performed better than multiaxial screws in the coronal and transverse planes (8% and 30% greater simulated corrections, respectively). Uniaxial and multiaxial screws were less effective than fixed-angle and saddle axial screws in transmitting compression/distraction to the anterior spine because of their sagittal plane mobility between the screw head and shank. Only the saddle axial screws allow vertebra angle in the sagittal plane to be independently adjusted. Pedicle screws of different designs performed differently for deformity corrections or for compensating screw placement variations in different anatomic planes. For a given AIS case, screw types should be determined based on the particular instrumentation objectives, the deformity's stiffness and characteristics so as to make the best of

Maturation and upregulation of functions of murine dendritic cells (DCs) under the influence of purified aromatic-turmerone (AR).

Science.gov (United States)

Yonggang, Tan; Yiming, Meng; Heying, Zhang; Cheng, Sun; Qiushi, Wang; Xianghong, Yang; Wei, Zheng; Huawei, Zhou; Shan, Fengping

2012-10-01

The aim of this work is to evaluate the effects of purified aromatic-turmerone (ar-turmerione, AR) on murine dendritic cells (DCs). These impacts of AR on DCs from bone marrow derived DCs(BMDCs) were assessed with use of conventional scanning electron microscopy (SEM), fluorescence activated cell sorting (FACS), transmission electron microscopy (TEM), cytochemistry assay, FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA). We found that AR induced phenotypic maturation as evidenced by increased expression of CD86, CD40, CD83, CD80 and major histocompatibility complex II (MHC II). The functional tests showed the activity of acidic phosphatase (ACP) inside the DCs were downregulated after treatment with AR (which occurs when phagocytosis of DCs were decreased). Finally, we proved that AR increased the production of IL-12 and tumor necrosis factor α (TNF-α). These data suggested that AR could promote phenotypic and functional maturation of DCs and this adjuvant-like activity may have potential therapeutic value. It is therefore concluded that AR could exert positive modulation on murine DCs.

Impact of DCS-facilitated cue exposure therapy on brain activation to cocaine cues in cocaine dependence.

Science.gov (United States)

Prisciandaro, James J; Myrick, Hugh; Henderson, Scott; McRae-Clark, Aimee L; Santa Ana, Elizabeth J; Saladin, Michael E; Brady, Kathleen T

2013-09-01

The development of addiction is marked by a pathological associative learning process that imbues incentive salience to stimuli associated with drug use. Recent efforts to treat addiction have targeted this learning process using cue exposure therapy augmented with d-cycloserine (DCS), a glutamatergic agent hypothesized to enhance extinction learning. To better understand the impact of DCS-facilitated extinction on neural reactivity to drug cues, the present study reports fMRI findings from a randomized, double-blind, placebo-controlled trial of DCS-facilitated cue exposure for cocaine dependence. Twenty-five participants completed two MRI sessions (before and after intervention), with a cocaine-cue reactivity fMRI task. The intervention consisted of 50mg of DCS or placebo, combined with two sessions of cocaine cue exposure and skills training. Participants demonstrated cocaine cue activation in a variety of brain regions at baseline. From the pre- to post-study scan, participants experienced decreased activation to cues in a number of regions (e.g., accumbens, caudate, frontal poles). Unexpectedly, placebo participants experienced decreases in activation to cues in the left angular and middle temporal gyri and the lateral occipital cortex, while DCS participants did not. Three trials of DCS-facilitated cue exposure therapy for cocaine dependence have found that DCS either increases or does not significantly impact response to cocaine cues. The present study adds to this literature by demonstrating that DCS may prevent extinction to cocaine cues in temporal and occipital brain regions. Although consistent with past research, results from the present study should be considered preliminary until replicated in larger samples. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Anodal-tDCS over the human right occipital cortex enhances the perception and memory of both faces and objects.

Science.gov (United States)

Barbieri, Marica; Negrini, Marcello; Nitsche, Michael A; Rivolta, Davide

2016-01-29

Accurate face processing skills are pivotal for typical social cognition, and impairments in this ability characterise various clinical conditions (e.g., prosopagnosia). No study to date has investigated whether transcranial direct current stimulation (tDCS) can causally enhance face processing. In addition, the category- and the process-specificity of tDCS effects, as well as the role of the timing of neuromodulation with respect to the execution of cognitive tasks are still unknown. In this single-blind, sham-controlled study, we examined whether the administration of anodal-tDCS (a-tDCS) over the right occipital cortex of healthy volunteers (N=64) enhances performance on perceptual and memory tasks involving both face and object stimuli. Neuromodulation was delivered in two conditions: online (a-tDCS during task execution) and offline (a-tDCS before task execution). The results demonstrate that offline a-tDCS enhances the perception and memory performance of both faces and objects. There was no effect of online a-tDCS on behaviour. Furthermore, the offline effect was site-specific since a-tDCS over the sensory-motor cortex did not lead to behavioural changes. Our results add relevant information about the breadth of cognitive processes and visual stimuli that can be modulated by tDCS, and about the design of effective neuromodulation protocols, which have implications for advancing theories in cognitive neuroscience and clinical applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Transcranial direct current stimulation (tDCS) for depression: Results of nearly a decade of clinical research].

Science.gov (United States)

Palm, U; Ayache, S S; Padberg, F; Lefaucheur, J-P

2016-02-01

Since 2006 transcranial direct current stimulation (tDCS) has been investigated in the treatment of depression. In this review, we discuss the implications and clinical perspectives that tDCS may have as a therapeutic tool in depression from the results reported in this domain. A comprehensive literature review has found nearly thirty articles - all in English - on this topic, corresponding to clinical studies, placebo-controlled or not, case reports and reviews. Several meta-analyses showed that the antidepressant effects of active tDCS are significant against placebo, but variable, mainly due to the heterogeneity of the patients included in the studies, for example regarding the resistance to antidepressant treatment. Specific recommendations for the use of tDCS in treating depression may not yet be available, but some elements of good practice can be highlighted. Of particular note is that anodal tDCS of the left prefrontal cortex at 2mA for 20 minutes per day has a potential therapeutic value without risk of significant side effects: tDCS offers safe conditions for clinical use in the treatment of depression. Copyright © 2015 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

The improvement of screw compressor performance using a newly developed rotor profile

International Nuclear Information System (INIS)

Kishi, Takayuki; Nishio, Toshio; Matsui, Akira; Ino, Nobumi

1994-01-01

An oil-compression phenomenon occurs at two portions of a conventional oil injected screw compressor that degrades the isothermal efficiency of the screw compressor. Hence a new screw rotor profile and lubricant have been developed in order to avoid the above oil-compression phenomena. Mycom and Fermi National Accelerator Laboratory have measured the performance of a new Mycom compound type screw compressor 2016C using the new profile rotors and the new lubricant. In the experiments, a 33% enhancement rate in the isothermal efficiency of the new screw compressor installed in Fermilab was achieved

Numerical study of internal flow in twin screw extruder and its mixing performance analysis

International Nuclear Information System (INIS)

Kim, Nak Soo; Kim, Hong Bum; Lee, Jae Wook

2006-01-01

We analyzed the non-Newtonian and non-isothermal flow in the melt conveying zone in co-rotating and counter-rotating screw extruder system with the commercial code, STAR-CD, and compared the mixing performance with respect to screw speed and rotating direction. The viscosity of fluid was described by power-law model. The dynamics of mixing was studied numerically by tracking the motion of particles in a twin screw extruder system. The extent of mixing was characterized in terms of the residence time distribution and average strain. The results showed that high screw speed decreases the residence time but increases the shear rate. Therefore higher screw speed increases the strain and has better mixing performance. Counter-rotating screw extruder system and co-rotating screw extruder has the similar shear rate with the same screw speed in spite of different rotating direction. However, the counter-rotating screw has good mixing performance, which is resulted from longer residence time than that of co-rotating screw extruder

The biomechanical consequences of rod reduction on pedicle screws: should it be avoided?

Science.gov (United States)

Paik, Haines; Kang, Daniel G; Lehman, Ronald A; Gaume, Rachel E; Ambati, Divya V; Dmitriev, Anton E

2013-11-01

Rod contouring is frequently required to allow for appropriate alignment of pedicle screw-rod constructs. When residual mismatch is still present, a rod persuasion device is often used to achieve further rod reduction. Despite its popularity and widespread use, the biomechanical consequences of this technique have not been evaluated. To evaluate the biomechanical fixation strength of pedicle screws after attempted reduction of a rod-pedicle screw mismatch using a rod persuasion device. Fifteen 3-level, human cadaveric thoracic specimens were prepared and scanned for bone mineral density. Osteoporotic (n=6) and normal (n=9) specimens were instrumented with 5.0-mm-diameter pedicle screws; for each pair of comparison level tested, the bilateral screws were equal in length, and the screw length was determined by the thoracic level and size of the vertebra (35 to 45 mm). Titanium 5.5-mm rods were contoured and secured to the pedicle screws at the proximal and distal levels. For the middle segment, the rod on the right side was intentionally contoured to create a 5-mm residual gap between the inner bushing of the pedicle screw and the rod. A rod persuasion device was then used to engage the setscrew. The left side served as a control with perfect screw/rod alignment. After 30 minutes, constructs were disassembled and vertebrae individually potted. The implants were pulled in-line with the screw axis with peak pullout strength (POS) measured in Newton (N). For the proximal and distal segments, pedicle screws on the right side were taken out and reinserted through the same trajectory to simulate screw depth adjustment as an alternative to rod reduction. Pedicle screws reduced to the rod generated a 48% lower mean POS (495±379 N) relative to the controls (954±237 N) (p.05). In circumstances where a rod is not fully seated within the pedicle screw, the use of a rod persuasion device decreases the overall POS and work energy to failure of the screw or results in outright

Low Intensity Focused tDCS Over the Motor Cortex Shows Inefficacy to Improve Motor Imagery Performance

Directory of Open Access Journals (Sweden)

Irma N. Angulo-Sherman

2017-07-01

Full Text Available Transcranial direct current stimulation (tDCS is a brain stimulation technique that can enhance motor activity by stimulating the motor path. Thus, tDCS has the potential of improving the performance of brain-computer interfaces during motor neurorehabilitation. tDCS effects depend on several aspects, including the current density, which usually varies between 0.02 and 0.08 mA/cm2, and the location of the stimulation electrodes. Hence, testing tDCS montages at several current levels would allow the selection of current parameters for improving stimulation outcomes and the comparison of montages. In a previous study, we found that cortico-cerebellar tDCS shows potential of enhancing right-hand motor imagery. In this paper, we aim to evaluate the effects of the focal stimulation of the motor cortex over motor imagery. In particular, the effect of supplying tDCS with a 4 × 1 ring montage, which consists in placing an anode on the motor cortex and four cathodes around it, over motor imagery was assessed with different current densities. Electroencephalographic (EEG classification into rest or right-hand/feet motor imagery was evaluated on five healthy subjects for two stimulation schemes: applying tDCS for 10 min on the (1 right-hand or (2 feet motor cortex before EEG recording. Accuracy differences related to the tDCS intensity, as well as μ and β band power changes, were tested for each subject and tDCS modality. In addition, a simulation of the electric field induced by the montage was used to describe its effect on the brain. Results show no improvement trends on classification for the evaluated currents, which is in accordance with the observation of variable EEG band power results despite the focused stimulation. The lack of effects is probably related to the underestimation of the current intensity required to apply a particular current density for small electrodes and the relatively short inter-electrode distance. Hence, higher current

Pullout strength of misplaced pedicle screws in the thoracic and lumbar vertebrae - A cadaveric study

Directory of Open Access Journals (Sweden)

Shyam K Saraf

2013-01-01

Full Text Available Background: The objective of this cadaveric study was to analyze the effects of iatrogenic pedicle perforations from screw misplacement on the mean pullout strength of lower thoracic and lumbar pedicle screws. We also investigated the effect of bone mineral density (BMD, diameter of pedicle screws, and the region of spine on the pullout strength of pedicle screws. Materials and Methods: Sixty fresh human cadaveric vertebrae (D10-L2 were harvested. Dual-energy X-ray absorptiometry (DEXA scan of vertebrae was done for BMD. Titanium pedicle screws of different diameters (5.2 and 6.2 mm were inserted in the thoracic and lumbar segments after dividing the specimens into three groups: a standard pedicle screw (no cortical perforation; b screw with medial cortical perforation; and c screw with lateral cortical perforation. Finally, pullout load of pedicle screws was recorded using INSTRON Universal Testing Machine. Results: Compared with standard placement, medially misplaced screws had 9.4% greater mean pullout strength and laterally misplaced screws had 47.3% lesser mean pullout strength. The pullout strength of the 6.2 mm pedicle screws was 33% greater than that of the 5.2 mm pedicle screws. The pullout load of pedicle screws in lumbar vertebra was 13.9% greater than that in the thoracic vertebra ( P = 0.105, but it was not statistically significant. There was no significant difference between pullout loads of vertebra with different BMD ( P = 0.901. Conclusion: The mean pullout strength was less with lateral misplaced pedicle screws while medial misplaced pedicle screw had more pullout strength. The pullout load of 6.2 mm screws was greater than that of 5.2 mm pedicle screws. No significant correlation was found between bone mineral densities and the pullout strength of vertebra. Similarly, the pullout load of screw placed in thoracic and lumbar vertebrae was not significantly different.

The impact of cerebellar transcranial direct current stimulation (tDCS) on learning fine-motor sequences.

Science.gov (United States)

Shimizu, Renee E; Wu, Allan D; Samra, Jasmine K; Knowlton, Barbara J

2017-01-05

The cerebellum has been shown to be important for skill learning, including the learning of motor sequences. We investigated whether cerebellar transcranial direct current stimulation (tDCS) would enhance learning of fine motor sequences. Because the ability to generalize or transfer to novel task variations or circumstances is a crucial goal of real world training, we also examined the effect of tDCS on performance of novel sequences after training. In Study 1, participants received either anodal, cathodal or sham stimulation while simultaneously practising three eight-element key press sequences in a non-repeating, interleaved order. Immediately after sequence practice with concurrent tDCS, a transfer session was given in which participants practised three interleaved novel sequences. No stimulation was given during transfer. An inhibitory effect of cathodal tDCS was found during practice, such that the rate of learning was slowed in comparison to the anodal and sham groups. In Study 2, participants received anodal or sham stimulation and a 24 h delay was added between the practice and transfer sessions to reduce mental fatigue. Although this consolidation period benefitted subsequent transfer for both tDCS groups, anodal tDCS enhanced transfer performance. Together, these studies demonstrate polarity-specific effects on fine motor sequence learning and generalization.This article is part of the themed issue 'New frontiers for statistical learning in the cognitive sciences'. © 2016 The Author(s).

Intermaxillary Fixation Screw Morbidity in Treatment of Mandibular Fractures

DEFF Research Database (Denmark)

Florescu, Vlad-Andrei; Kofod, Thomas; Pinholt, Else Marie

2016-01-01

Purpose The aim of the present retrospective study was to investigate the morbidity of screws used for intermaxillary fixation (IMF) in the treatment of mandibular fractures. A review of the published data was also performed for a comparison of outcomes. Our hypothesis was that the use of screws...... for IMF of mandibular fractures would result in minimal morbidity. Materials and Methods Patients treated for mandibular fractures from 2007 to 2013, using screws for IMF, using the international diagnosis code for mandibular fracture, DS026, were anonymously selected (Department of Oral and Maxillofacial...... Surgery, Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark). The fracture type, radiographic findings, treatment modality, screw type and number, and root damage were recorded. For the outcome comparison, a review of the published data regarding iatrogenic dental root damage caused...

The Analysis of Soil Resistance During Screw Displacement Pile Installation

Science.gov (United States)

Krasinski, Adam

2015-02-01

The application of screw displacement piles (SDP) is still increasing due to their high efficiency and many advantages. However, one technological problem is a serious disadvantage of those piles. It relates to the generation of very high soil resistance during screw auger penetration, especially when piles are installed in non-cohesive soils. In many situations this problem causes difficulties in creating piles of designed length and diameter. It is necessary to find a proper method for prediction of soil resistance during screw pile installation. The analysis of screw resistances based on model and field tests is presented in the paper. The investigations were carried out as part of research project, financed by the Polish Ministry of Science and Higher Education. As a result of tests and analyses the empirical method for prediction of rotation resistance (torque) during screw auger penetration in non-cohesive subsoil based on CPT is proposed.

Transcranial direct current stimulation (tDCS) for idiopathic Parkinson's disease.

Science.gov (United States)

Elsner, Bernhard; Kugler, Joachim; Pohl, Marcus; Mehrholz, Jan

2016-07-18

Idiopathic Parkinson's disease (IPD) is a neurodegenerative disorder, with the severity of the disability usually increasing with disease duration. IPD affects patients' health-related quality of life, disability, and impairment. Current rehabilitation approaches have limited effectiveness in improving outcomes in patients with IPD, but a possible adjunct to rehabilitation might be non-invasive brain stimulation by transcranial direct current stimulation (tDCS) to modulate cortical excitability, and hence to improve these outcomes in IPD. To assess the effectiveness of tDCS in improving motor and non-motor symptoms in people with IPD. We searched the following databases (until February 2016): the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library ; 2016 , Issue 2), MEDLINE, EMBASE, CINAHL, AMED, Science Citation Index, the Physiotherapy Evidence Database (PEDro), Rehabdata, and Inspec. In an effort to identify further published, unpublished, and ongoing trials, we searched trial registers and reference lists, handsearched conference proceedings, and contacted authors and equipment manufacturers. We included only randomised controlled trials (RCTs) and randomised controlled cross-over trials that compared tDCS versus control in patients with IPD for improving health-related quality of life , disability, and impairment. Two review authors independently assessed trial quality (JM and MP) and extracted data (BE and JM). If necessary, we contacted study authors to ask for additional information. We collected information on dropouts and adverse events from the trial reports. We included six trials with a total of 137 participants. We found two studies with 45 participants examining the effects of tDCS compared to control (sham tDCS) on our primary outcome measure, impairment, as measured by the Unified Parkinson's Disease Rating Scale (UPDRS). There was very low quality evidence for no effect of tDCS on change in global UPDRS score ( mean

Assessment of anodal and cathodal transcranial direct current stimulation (tDCS) on MMN-indexed auditory sensory processing.

Science.gov (United States)

Impey, Danielle; de la Salle, Sara; Knott, Verner

2016-06-01

Transcranial direct current stimulation (tDCS) is a non-invasive form of brain stimulation which uses a very weak constant current to temporarily excite (anodal stimulation) or inhibit (cathodal stimulation) activity in the brain area of interest via small electrodes placed on the scalp. Currently, tDCS of the frontal cortex is being used as a tool to investigate cognition in healthy controls and to improve symptoms in neurological and psychiatric patients. tDCS has been found to facilitate cognitive performance on measures of attention, memory, and frontal-executive functions. Recently, a short session of anodal tDCS over the temporal lobe has been shown to increase auditory sensory processing as indexed by the Mismatch Negativity (MMN) event-related potential (ERP). This preliminary pilot study examined the separate and interacting effects of both anodal and cathodal tDCS on MMN-indexed auditory pitch discrimination. In a randomized, double blind design, the MMN was assessed before (baseline) and after tDCS (2mA, 20min) in 2 separate sessions, one involving 'sham' stimulation (the device is turned off), followed by anodal stimulation (to temporarily excite cortical activity locally), and one involving cathodal stimulation (to temporarily decrease cortical activity locally), followed by anodal stimulation. Results demonstrated that anodal tDCS over the temporal cortex increased MMN-indexed auditory detection of pitch deviance, and while cathodal tDCS decreased auditory discrimination in baseline-stratified groups, subsequent anodal stimulation did not significantly alter MMN amplitudes. These findings strengthen the position that tDCS effects on cognition extend to the neural processing of sensory input and raise the possibility that this neuromodulatory technique may be useful for investigating sensory processing deficits in clinical populations. Copyright © 2016 Elsevier Inc. All rights reserved.

Microbial carriage state of peripheral blood dendritic cells (DCs) in chronic periodontitis influences DC differentiation, atherogenic potential.

Science.gov (United States)

Carrion, Julio; Scisci, Elizabeth; Miles, Brodie; Sabino, Gregory J; Zeituni, Amir E; Gu, Ying; Bear, Adam; Genco, Caroline A; Brown, David L; Cutler, Christopher W

2012-09-15

The low-grade oral infection chronic periodontitis (CP) has been implicated in coronary artery disease risk, but the mechanisms are unclear. In this study, a pathophysiological role for blood dendritic cells (DCs) in systemic dissemination of oral mucosal pathogens to atherosclerotic plaques was investigated in humans. The frequency and microbiome of CD19(-)BDCA-1(+)DC-SIGN(+) blood myeloid DCs (mDCs) were analyzed in CP subjects with or without existing acute coronary syndrome and in healthy controls. FACS analysis revealed a significant increase in blood mDCs in the following order: healthy controls < CP < acute coronary syndrome/CP. Analysis of the blood mDC microbiome by 16S rDNA sequencing showed Porphyromonas gingivalis and other species, including (cultivable) Burkholderia cepacia. The mDC carriage rate with P. gingivalis correlated with oral carriage rate and with serologic exposure to P. gingivalis in CP subjects. Intervention (local debridement) to elicit a bacteremia increased the mDC carriage rate and frequency in vivo. In vitro studies established that P. gingivalis enhanced by 28% the differentiation of monocytes into immature mDCs; moreover, mDCs secreted high levels of matrix metalloproteinase-9 and upregulated C1q, heat shock protein 60, heat shock protein 70, CCR2, and CXCL16 transcripts in response to P. gingivalis in a fimbriae-dependent manner. Moreover, the survival of the anaerobe P. gingivalis under aerobic conditions was enhanced when within mDCs. Immunofluorescence analysis of oral mucosa and atherosclerotic plaques demonstrate infiltration with mDCs, colocalized with P. gingivalis. Our results suggest a role for blood mDCs in harboring and disseminating pathogens from oral mucosa to atherosclerosis plaques, which may provide key signals for mDC differentiation and atherogenic conversion.

Inter- and Intra-individual Variability in Response to Transcranial Direct Current Stimulation (tDCS) at Varying Current Intensities.

Science.gov (United States)

Chew, Taariq; Ho, Kerrie-Anne; Loo, Colleen K

2015-01-01

Translation of transcranial direct current stimulation (tDCS) from research to clinical practice is hindered by a lack of consensus on optimal stimulation parameters, significant inter-individual variability in response, and in sufficient intra-individual reliability data. Inter-individual differences in response to anodal tDCS at a range of current intensities were explored. Intra-individual reliability in response to anodal tDCS across two identical sessions was also investigated. Twenty-nine subjects participated in a crossover study. Anodal-tDCS using four different current intensities (0.2, 0.5, 1 and 2 mA), with an anode size of 16 cm2, was tested. The 0.5 mA condition was repeated to assess intra-individual variability. TMS was used to elicit 40 motor-evoked potentials (MEPs) before 10 min of tDCS, and 20 MEPs at four time-points over 30 min following tDCS. ANOVA revealed no main effect of TIME for all conditions except the first 0.5 mA condition, and no differences in response between the four current intensities. Cluster analysis identified two clusters for the 0.2 and 2 mA conditions only. Frequency distributions based on individual subject responses (excitatory, inhibitory or no response) to each condition indicate possible differential responses between individuals to different current intensities. Test-retest reliability was negligible (ICC(2,1) = -0.50). Significant inter-individual variability in response to tDCS across a range of current intensities was found. 2 mA and 0.2 mA tDCS were most effective at inducing a distinct response. Significant intra-individual variability in response to tDCS was also found. This has implications for interpreting results of single-session tDCS experiments. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Third metacarpal condylar fatigue fractures in equine athletes occur within previously modelled subchondral bone.

Science.gov (United States)

Whitton, R Christopher; Trope, Gareth D; Ghasem-Zadeh, Ali; Anderson, Garry A; Parkin, Timothy D H; Mackie, Eleanor J; Seeman, Ego

2010-10-01

Bone modelling and remodelling reduce the risk of fatigue fractures; the former by adapting bone to its loading circumstances, the latter by replacing fatigued bone. Remodelling transiently increases porosity because of the normal delay in onset of the formation phase of the remodelling sequence. Protracted intense loading suppresses remodelling leaving modelling as the only means of maintaining bone strength. We therefore hypothesized that race horses with fatigue fractures of the distal third metacarpal bone (MC3) will have reduced porosity associated with suppressed remodelling while continued adaptive modelling will result in higher volume fraction (BV/TV) at this site. Using high resolution peripheral quantitative computed tomography (HR-pQCT), we measured the distal aspect of the MC3 obtained at postmortem from 13 thoroughbred race horses with condylar fractures of the MC3 (cases), 8 horses without fractures (training controls), 14 horses with a fracture at another site (fractured controls) and 9 horses resting from training (resting controls). Porosity of the subchondral bone of MC3 was lower in cases than resting controls (12±1.4% vs. 18±1.6%, P=0.017) although areas of focal porosity were observed adjacent to fractures in 6/13 horses. BV/TV of the distal metacarpal epiphysis tended to be higher in horses with condylar fractures (0.79±0.015) than training controls (0.74±0.019, P=0.070), but also higher in controls with a fracture elsewhere (0.79±0.014) than the training controls (0.74±0.019, P=0.040). BV/TV was higher in horses over three years of age than those aged two or three years (0.79±0.01 vs. 0.74±0.01, P=0.016). All metacarpal condylar fractures occurred within focal areas of high BV/TV. We infer that intense training in equine athletes suppresses remodelling of third metacarpal subchondral bone limiting damage repair while modelling increases regional bone volume in an attempt to minimise local stresses but may fail to offset bone

Enhancement of selective attention by tDCS: interaction with interference in a Sternberg task

NARCIS (Netherlands)

Gladwin, T.E.; den Uyl, T.E.; Fregni, F.F.; Wiers, R.W.

2012-01-01

Transcranial Direct Current Stimulation (tDCS) enhances performance on working memory tasks. However, such effects may be dependent on modulation of specific aspects of working memory. We therefore tested the hypothesis that tDCS improves selective attention in the context of a Sternberg task.

Comparison of accuracy of lag screw placement in cephalocondylic nails and sliding hip screw plate fixation for extracapsular fractures of the neck of femur

OpenAIRE

Shyam Kumar, A. J.; Parmar, V.; Bankart, J.; Williams, S. C.; Harper, W. M.

2006-01-01

This study compared the accuracy of lag screw placement between extracapsular femoral fractures fixed with sliding hip screw plate systems and those fixed with cephalocondylic nails. It involved 75 retrospective radiographs of fractures fixed with either a cephalocondylic nail (32) or a sliding hip screw plate system (43). Postoperative anteroposterior and lateral radiographs of the hip were scanned using a digital X-ray scanner and measured using computer software. Measurements were conducte...

Chronic sleep restriction induces changes in the mandibular condylar cartilage of rats: roles of Akt, Bad and Caspase-3.

Science.gov (United States)

Zhu, Yong; Wu, Gaoyi; Zhu, Guoxiong; Ma, Chuan; Zhao, Huaqiang

2014-01-01

The aim of the present study was to observe changes in the temporomandibular joint (TMJ) of rats that had been subjected to chronic sleep restriction and to investigate whether Akt, Bad and Caspase3 play a role in the mechanism underlying the changes. One hundred and eighty male Wistar rats were randomly divided into three groups (n = 60 in each): cage control group, large-platform control group, and sleep restriction group. Each group was divided into three subgroups (n = 20 in each) of three different time points (7, 14 and 21 days), respectively. The modified multiple platform method was used to induce chronic sleep restriction. The TMJ tissue histology was studied by staining with haematoxylin and eosin. The expression of Akt, p-Aktser473, Bad, p-Badser136 and Caspase3 proteins was detected by immunohistochemistry and western blotting. The expression of Akt, Bad and Caspase3 mRNAs was measured by real-time quantitative polymerase chain reaction (RT-qPCR). Compared with the large-platform and cage control groups, condylar cartilage pathological alterations were found in the sleep restriction group. There were significantly decreased expression levels of Akt, p-Aktser473 and p-Badser136 and significantly increased expression levels of Bad and Caspase3 after sleep restriction. These data suggest that sleep restriction may induce pathological alterations in the condylar cartilage of rats. Alterations in Akt, Bad and Caspase3 may be associated with the potential mechanism by which chronic sleep restriction influences the condylar cartilage.

Process and device for the ultrasonic testing of slotted screws screwed into a head of a nuclear reactor fuel element for cracks

International Nuclear Information System (INIS)

Scharpenberg, R.

1986-01-01

To achieve correct echo signals, a test head is set separately on each area limited by a slot of the top of the slotted screw and the screw head is ultrasonically sounded in the direction of the suspected cracks. (orig./HP) [de

Anodal tDCS over the Primary Motor Cortex Facilitates Long-Term Memory Formation Reflecting Use-Dependent Plasticity.

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Orjon Rroji

Full Text Available Previous research suggests that anodal transcranial direct current stimulation (tDCS over the primary motor cortex (M1 modulates NMDA receptor dependent processes that mediate synaptic plasticity. Here we test this proposal by applying anodal versus sham tDCS while subjects practiced to flex the thumb as fast as possible (ballistic movements. Repetitive practice of this task has been shown to result in performance improvements that reflect use-dependent plasticity resulting from NMDA receptor mediated, long-term potentiation (LTP-like processes. Using a double-blind within-subject cross-over design, subjects (n=14 participated either in an anodal or a sham tDCS session which were at least 3 months apart. Sham or anodal tDCS (1 mA was applied for 20 min during motor practice and retention was tested 30 min, 24 hours and one week later. All subjects improved performance during each of the two sessions (p < 0.001 and learning gains were similar. Our main result is that long term retention performance (i.e. 1 week after practice was significantly better when practice was performed with anodal tDCS than with sham tDCS (p < 0.001. This effect was large (Cohen's d=1.01 and all but one subject followed the group trend. Our data strongly suggest that anodal tDCS facilitates long-term memory formation reflecting use-dependent plasticity. Our results support the notion that anodal tDCS facilitates synaptic plasticity mediated by an LTP-like mechanism, which is in accordance with previous research.

[Differential expression of IGF-I and its mRNA in mandibular condylar cartilage of rat--direct evidence for servosystem theory of facial growth].

Science.gov (United States)

Zhou, Z; Luo, S

1998-05-01

It was studied the expression of IGF-I and its mRNA in the condylar cartilage of 10 7-week-old SD male rats by using in situ hybridization and immunohisto-chemistry technique. The results showed both IGF-I and its gene expressed in growing rat condyle. IGF-I peptide was abundant in germinal zone, and positive reaction of its mRNA was strongest in transitional and maturational zones. These indicate that condylar cartilage has the capability of local production and secretion of IGF-I, mediating the command effect of STH, and differential expression of IGF-I and its mRNA might establish the local feedback loop, which supply a direct evidence for servosystem theory of facial growth.

The Analysis of Soil Resistance During Screw Displacement Pile Installation

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Krasinski Adam

2015-02-01

Full Text Available The application of screw displacement piles (SDP is still increasing due to their high efficiency and many advantages. However, one technological problem is a serious disadvantage of those piles. It relates to the generation of very high soil resistance during screw auger penetration, especially when piles are installed in non-cohesive soils. In many situations this problem causes difficulties in creating piles of designed length and diameter. It is necessary to find a proper method for prediction of soil resistance during screw pile installation. The analysis of screw resistances based on model and field tests is presented in the paper. The investigations were carried out as part of research project, financed by the Polish Ministry of Science and Higher Education. As a result of tests and analyses the empirical method for prediction of rotation resistance (torque during screw auger penetration in non-cohesive subsoil based on CPT is proposed.

Preload, Coefficient of Friction, and Thread Friction in an Implant-Abutment-Screw Complex.

Science.gov (United States)

Wentaschek, Stefan; Tomalla, Sven; Schmidtmann, Irene; Lehmann, Karl Martin

To examine the screw preload, coefficient of friction (COF), and tightening torque needed to overcome the thread friction of an implant-abutment-screw complex. In a customized load frame, 25 new implant-abutment-screw complexes including uncoated titanium alloy screws were torqued and untorqued 10 times each, applying 25 Ncm. Mean preload values decreased significantly from 209.8 N to 129.5 N according to the number of repetitions. The overall COF increased correspondingly. There was no comparable trend for the thread friction component. These results suggest that the application of a used implant-abutment-screw complex may be unfavorable for obtaining optimal screw preload.

Noninvasive transcranial direct current stimulation (tDCS) for the treatment of orofacial pain.

Science.gov (United States)

Fricova, Jitka; Englerova, Katerina; Rokyta, Richard

2016-10-01

tDCS is a promising method for the treatment of chronic pain. Electrode placement locations must be chosen in accordance with the density and the time course of the current in order to prevent pathological changes in the underlying tissue. In order to reduce current spatial variability, more electrodes of the same polarity are placed in a circle around the second electrode of the opposite polarity. The applied current produced the greatest changes directly beneath the electrodes: the cathode reduces the excitability of cortical neurons, while the anode has the opposite effect. Based on inclusion criteria, 10 patients with chronic orofacial pain, secondary trigeminal neuralgia after oral surgery, were enrolled and underwent both anode and cathode stimulation. Before the first session we measured pain intensity on a numeric pain rating scale and tactile and thermal stimulation were used to assess somatosensory status. tDCS was applied for five consecutive days. At the end of tDCS application, somatosensory status was assessed again. From our results we can conclude that the application of tDCS improves the perception of some types of pain. When we increase our sample size, we would expect confirmation not only on our positive results, but also some additional findings for explaining the pathophysiology of orofacial pain. These pathophysiological findings and explanations are very important for the application of tDCS in the treatment of orofacial pain and also for other types of neuropathic pain.

Translaminar screw fixation in the lumbar spine: technique, indications, results

OpenAIRE

Grob, D.; Humke, T.

1998-01-01

Translaminar screw fixation of the lumbar spine represents a simple and effective technique for short segment fusion in the degenerative spine. Clinical experience with 173 patients who underwent translaminar screw fixation revealed a fusion rate of 94%. The indications for translaminar screw fixation as a primary fixation procedure are: segmental dysfunction, lumbar spinal stenosis with painful degenerative changes, segmental revision surgery after discectomies, and painful disc-related synd...

Spelling rehabilitation using transcranial direct current (tDCS in primary progressive aphasia (PPA.

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Constantine Frangakis

2014-04-01

Full Text Available Introduction: Spelling impairments are one of the first deficits that occur early in PPA and can usually predict the variant of PPA in which the patient may progress (Sepelyak et al., 2011. PPA is a neurodegenerative disease that affects people relatively early in life (between 55-65 years and therefore it is important to find ways to alleviate the symptoms or impede the degree of degeneration. We present and discuss new data indicating that a neuromodulatory treatment, using transcranial direct current stimulation (tDCS combined with a spelling intervention, shows promise for maintaining or even improving language abilities in PPA. The aim of this research is to determine whether tDCS plus language therapy is more effective than language therapy alone in treating written language deficits in PPA. Methods: Eight PPA participants underwent anodal tDCS or sham plus spelling intervention in a randomized order using a within-subject cross-over design. They were evaluated before, after, and at 2 weeks and 2 months post-intervention. Spelling intervention varied for each participant according to the main spelling deficit: 3 patients had phoneme-to-grapheme conversion (PGC intervention, 2 had lexical intervention and 3 had advanced PGC intervention (combined with written fluency and PGC practice. Four more patients have already finished the first period of stimulations (ether sham or tDCS and all their other sessions and evaluations will be completed in the next couple months. Analyses-Results: We analyzed the existing set of full data using both within-subject analyses (McNemar tests and across-subjects analyses while taking into account carry-over effects. We evaluated therapy effects by the Generalized Estimating Equation approach (Liang & Zeger, 1986. All participants showed improvement in spelling after spelling intervention in trained items (with either sham or tDCS. There was, however, a significant improvement for untrained items only in the tDCS

Enhancing performance in numerical magnitude processing and mental arithmetic using transcranial Direct Current Stimulation (tDCS

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Tobias U. Hauser

2013-06-01

Full Text Available The ability to accurately process numerical magnitudes and solve mental arithmetic is of highest importance for schooling and professional career. Although impairments in these domains in disorders such as developmental dyscalculia (DD are highly detrimental, remediation is still sparse. In recent years, transcranial brain stimulation methods such as transcranial Direct Current Stimulation (tDCS have been suggested as a treatment for various neurologic and neuropsychiatric disorders. The posterior parietal cortex (PPC is known to be crucially involved in numerical magnitude processing and mental arithmetic. In this study, we evaluated whether tDCS has a beneficial effect on numerical magnitude processing and mental arithmetic. Due to the unclear lateralization, we stimulated the left, right as well as both hemispheres simultaneously in two experiments. We found that left anodal tDCS significantly enhanced performance in a number comparison and a subtraction task, while bilateral and right anodal tDCS did not induce any improvements compared to sham. Our findings demonstrate that the left PPC is causally involved in numerical magnitude processing and mental arithmetic. Furthermore, we show that these cognitive functions can be enhanced by means of tDCS. These findings encourage to further investigate the beneficial effect of tDCS in the domain of mathematics in healthy and impaired humans.

Detection of tibial condylar fractures using 3D imaging with a mobile image amplifier (Siemens ISO-C-3D): Comparison with plain films and spiral CT

International Nuclear Information System (INIS)

Kotsianos, D.; Rock, C.; Wirth, S.; Linsenmaier, U.; Brandl, R.; Fischer, T.; Pfeifer, K.J.; Reiser, M.; Euler, E.; Mutschler, W.

2002-01-01

Purpose: To analyze a prototype mobile C-arm 3D image amplifier in the detection and classification of experimental tibial condylar fractures with multiplanar reconstructions (MPR). Method: Human knee specimens (n=22) with tibial condylar fractures were examined with a prototype C-arm (ISO-C-3D, Siemens AG), plain films (CR) and spiral CT (CT). The motorized C-arm provides fluoroscopic images during a 190 orbital rotation computing a 119 mm data cube. From these 3D data sets MP reconstructions were obtained. All images were evaluated by four independent readers for the detection and assessment of fracture lines. All fractures were classified according to the Mueller AO classification. To confirm the results, the specimens were finally surgically dissected. Results: 97% of the tibial condylar fractures were easily seen and correctly classified according to the Mueller AO classification on MP reconstruction of the ISO-C-3D. There is no significant difference between ISO-C and CT in detection and correct classification of fractures, but ISO-CD-3D is significant by better than CR. (orig.) [de

Two New Chroman Derivations from the Endophytic Penicillium sp. DCS523

OpenAIRE

Li, Jun-Tian; Fu, Xiao-Li; Tan, Chun; Zeng, Ying; Wang, Qi; Zhao, Pei-Ji

2011-01-01

Strain DCS523 was isolated from the branch tissue of Daphniphyllum longeracemosum and determined to be a Penicillium sp. according to the ITS sequence analysis. The extracts from the PDA solid fermentation media of Penicillium sp. DCS523 were purified to give two new chroman derivatives as well as six known compounds. Based on their spectral data the new compounds were identified as (Z)-6-acetyl- 3-(1,2-dihydroxypropylidene)-5-hydroxy-8-methylchroman-2-one (1) and 6-acetyl-2α,5- dihydroxy-2-(...

Inspection and replacement of baffle assembly screws inside American reactor vessels

International Nuclear Information System (INIS)

Neal, K.; Chaumont, J.C.

1999-01-01

The baffle assembly inside the vessel of a 900 MWe reactor designed by Framatome, is made up of 44 plates fixed on 8 horizontal supports by a system of about 1000 screws. These plates undergo high neutron flux and the problem of screw cracking appeared at the end of the eighties in the first-generation reactors. The first operation on a large scale concerning the screws of a Westinghouse type reactor, was performed on the Tihange-1 power plant where Framatome controlled 960 screws and replaced 91. In 1997 as a consequence of the Belgian and French feedback experience, American plant operators launched a vast program of preventive actions: material analysis, inspection of baffle plate screws and replacement of defective screws. This program was held in cooperation with EPRI (electric power research institute) and under the control of NRC (nuclear regulatory commission). Framatome Technologies Inc (FTI) was in charge of the in-situ inspection and replacement of the screws. FTI designed special tools and equipment adapted to the 2-loop American reactors but the basis ideas were those applied on the Tihange reactor. The successful experience of FTI has allowed the firm to be commissioned for 6 2-loops American reactors. (A.C.)

Self-Administered Domiciliary tDCS Treatment for Tinnitus: A Double-Blind Sham-Controlled Study.

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Petteri Hyvärinen

Full Text Available Transcranial direct current stimulation (tDCS has shown potential for providing tinnitus relief, although positive effects have usually been observed only during a short time period after treatment. In recent studies the focus has turned from one-session experiments towards multi-session treatment studies investigating long-term outcomes with double-blinded and sham-controlled study designs. Traditionally, tDCS has been administered in a clinical setting by a healthcare professional but in studies involving multiple treatment sessions, often a trade-off has to be made between sample size and the amount of labor needed to run the trial. Also, as the number of required visits to the clinic increases, the dropout rate is likely to rise proportionally.The aim of the current study was to find out if tDCS treatment for tinnitus could be patient-administered in a domiciliary setting and whether the results would be comparable to those from in-hospital treatment studies. Forty-three patients with chronic (> 6 months tinnitus were involved in the study, and data on 35 out of these patients were included in final analysis. Patients received 20 minutes of left temporal area anodal (LTA or bifrontal tDCS stimulation (2 mA or sham stimulation (0.3 mA for ten consecutive days. An overall reduction in the main outcome measure, Tinnitus Handicap Inventory (THI, was found (mean change -5.0 points, p < 0.05, but there was no significant difference between active and sham treatment outcomes. Patients found the tDCS treatment easy to administer and they all tolerated it well. In conclusion, self-administered domiciliary tDCS treatment for tinnitus was found safe and feasible and gave outcome results similar to recent randomized controlled long-term treatment trials. The results suggest better overall treatment response-as measured by THI-with domiciliary treatment than with in-hospital treatment, but this advantage is not related to the tDCS variant. The study

Fracture resistance of abutment screws made of titanium, polyetheretherketone, and carbon fiber-reinforced polyetheretherketone

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Eduardo Aloisio Fleck NEUMANN

2014-08-01

Full Text Available Fractured abutment screws may be replaced; however, sometimes, the screw cannot be removed and the entire implant must be surgically removed and replaced. The aim of this study was to compare the fracture resistance of abutment retention screws made of titanium, polyetheretherketone (PEEK and 30% carbon fiber-reinforced PEEK, using an external hexagonal implant/UCLA-type abutment interface assembly. UCLA-type abutments were fixed to implants using titanium screws (Group 1, polyetheretherketone (PEEK screws (Group 2, and 30% carbon fiber-reinforced PEEK screws (Group 3. The assemblies were placed on a stainless steel holding apparatus to allow for loading at 45o off-axis, in a universal testing machine. A 200 N load (static load was applied at the central point of the abutment extremity, at a crosshead speed of 5 mm/minute, until failure. Data was analyzed by ANOVA and Tukey’s range test. The titanium screws had higher fracture resistance, compared with PEEK and 30% carbon fiber-reinforced PEEK screws (p 0.05. Finally, visual analysis of the fractions revealed that 100% of them occurred at the neck of the abutment screw, suggesting that this is the weakest point of this unit. PEEK abutment screws have lower fracture resistance, in comparison with titanium abutment screws.

Fracture resistance of abutment screws made of titanium, polyetheretherketone, and carbon fiber-reinforced polyetheretherketone.

Science.gov (United States)

Neumann, Eduardo Aloisio Fleck; Villar, Cristina Cunha; França, Fabiana Mantovani Gomes

2014-01-01

Fractured abutment screws may be replaced; however, sometimes, the screw cannot be removed and the entire implant must be surgically removed and replaced. The aim of this study was to compare the fracture resistance of abutment retention screws made of titanium, polyetheretherketone (PEEK) and 30% carbon fiber-reinforced PEEK, using an external hexagonal implant/UCLA-type abutment interface assembly. UCLA-type abutments were fixed to implants using titanium screws (Group 1), polyetheretherketone (PEEK) screws (Group 2), and 30% carbon fiber-reinforced PEEK screws (Group 3). The assemblies were placed on a stainless steel holding apparatus to allow for loading at 45o off-axis, in a universal testing machine. A 200 N load (static load) was applied at the central point of the abutment extremity, at a crosshead speed of 5 mm/minute, until failure. Data was analyzed by ANOVA and Tukey's range test. The titanium screws had higher fracture resistance, compared with PEEK and 30% carbon fiber-reinforced PEEK screws (p 0.05). Finally, visual analysis of the fractions revealed that 100% of them occurred at the neck of the abutment screw, suggesting that this is the weakest point of this unit. PEEK abutment screws have lower fracture resistance, in comparison with titanium abutment screws.

Strength evaluation of top nozzle holddown spring screw for nuclear fuel assembly

International Nuclear Information System (INIS)

Koh, S. K.; Won, S. Y.; Ryu, C. H.; Kim, Y. J.; Lee, K. S.; Jeon, K. L.

2002-01-01

Holddown springs are required to maintain the nuclear fuel assembly in contact with lower core plate and permit thermal and irradiation-induced length changes. Therefore, the holddown spring screw must be designed such that it is capable of sustaining the loads imposed by the initial tensile preload and operational loads. Prior to assessing the structural integrity of the spring screw in the corrosive and irradiating environment throughout the design lifetime of the fuel assembly, the strength evaluation of screw was made in this paper using the mechanics of materials and finite element methods. Calculations based on the mechanics of materials, showed that the preloaded screw with an operating holddown force had a quite large margin of safety in strength. However, the elastic-plastic finite element analysis showed that the local stresses at the critical regions of head-shank fillet and thread root significantly exceeded than the yield strength of the screw material, resulting in local plastic deformation. Preloading on the screw applied for tightening had beneficial effects on the screw strength by reducing the stress level at the critical regions, compared to the screw without preload. Calculated spring deflection using the finite element analysis was in close agreement with the experimentally measured deflection

Comparative effect of implant-abutment connections, abutment angulations, and screw lengths on preloaded abutment screw using three-dimensional finite element analysis: An in vitro study

OpenAIRE

Krishna Chaitanya Kanneganti; Dileep Nag Vinnakota; Srinivas Rao Pottem; Mahesh Pulagam

2018-01-01

Purpose: The purpose of this study is to compare the effect of implant-abutment connections, abutment angulations, and screw lengths on screw loosening (SL) of preloaded abutment using three dimensional (3D) finite element analysis. Materials and Methods: 3D models of implants (conical connection with hex/trilobed connections), abutments (straight/angulated), abutment screws (short/long), and crown and bone were designed using software Parametric Technology Corporation Creo and assembled t...

Transcranial direct current stimulation (tDCS) neuromodulatory effects on mechanical hyperalgesia and cortical BDNF levels in ovariectomized rats.

Science.gov (United States)

da Silva Moreira, Sônia Fátima; Medeiros, Liciane Fernandes; de Souza, Andressa; de Oliveira, Carla; Scarabelot, Vanessa Leal; Fregni, Felipe; Caumo, Wolnei; Torres, Iraci L S

2016-01-15

Epidemiological studies show that painful disorders are more prevalent in women than in men, and the transcranial direct current stimulation (tDCS) technique has been tested in chronic pain states. We explored the effect of tDCS on pain behavior and brain-derived neurotrophic factor (BDNF) levels in ovariectomized rats. Forty-five female Wistar adult rats were distributed into five groups: control (CT), ovariectomy + tDCS (OT), ovariectomy + sham tDCS (OS), sham ovariectomy + tDCS (ST), and sham ovariectomy+shamtDCS (SS). The rats were subjected to cathodal tDCS. The vaginal cytology and the estradiol levels confirmed the hormonal status. In addition, nociceptive behavior was evaluated using the tail-flick, von Frey, and hot-plate tests, as well as the BDNF levels in the serum, hypothalamus, hippocampus, spinal cord, and cerebral cortex. One-way analysis of variance (ANOVA) or two-way ANOVA was used for statistical analysis, followed by the Bonferroni, and P-value b 0.05 was considered significant. The ovariectomized animals presented a hypersensitivity response in the hot-plate (P b 0.01) and von Frey (P b 0.05) tests, as well as increased serum BDNF (P b 0.05) and decreased hypothalamic BDNF (P b 0.01) levels. The OT, OS, ST, and SS groups showed decreased hippocampal BDNF levels as compared with the control group (P b 0.001). The interaction between tDCS and ovariectomy on the cortical BDNF levels (P b 0.01) was observed. The ovariectomy induced nociceptive hypersensitivity and altered serum and hypothalamic BDNF levels. The cathodal tDCS partially reversed nociceptive hypersensitivity.

Screw expander for light duty diesel engines

Science.gov (United States)

1983-01-01

Preliminary selection and sizing of a positive displacement screw compressor-expander subsystem for a light-duty adiabatic diesel engine; development of a mathematical model to describe overall efficiencies for the screw compressor and expander; simulation of operation to establish overall efficiency for a range of design parameters and at given engine operating points; simulation to establish potential net power output at light-duty diesel operating points; analytical determination of mass moments of inertia for the rotors and inertia of the compressor-expander subsystem; and preparation of engineering layout drawings of the compressor and expander are discussed. As a result of this work, it was concluded that the screw compressor and expander designed for light-duty diesel engine applications are viable alternatives to turbo-compound systems, with acceptable efficiencies for both units, and only a moderate effect on the transient response.

Transcranial direct current stimulation (tDCS) facilitates overall visual search response times but does not interact with visual search task factors.

Science.gov (United States)

Sung, Kyongje; Gordon, Barry

2018-01-01

Whether transcranial direct current stimulation (tDCS) affects mental functions, and how any such effects arise from its neural effects, continue to be debated. We investigated whether tDCS applied over the visual cortex (Oz) with a vertex (Cz) reference might affect response times (RTs) in a visual search task. We also examined whether any significant tDCS effects would interact with task factors (target presence, discrimination difficulty, and stimulus brightness) that are known to selectively influence one or the other of the two information processing stages posited by current models of visual search. Based on additive factor logic, we expected that the pattern of interactions involving a significant tDCS effect could help us colocalize the tDCS effect to one (or both) of the processing stages. In Experiment 1 (n = 12), anodal tDCS improved RTs significantly; cathodal tDCS produced a nonsignificant trend toward improvement. However, there were no interactions between the anodal tDCS effect and target presence or discrimination difficulty. In Experiment 2 (n = 18), we manipulated stimulus brightness along with target presence and discrimination difficulty. Anodal and cathodal tDCS both produced significant improvements in RTs. Again, the tDCS effects did not interact with any of the task factors. In Experiment 3 (n = 16), electrodes were placed at Cz and on the upper arm, to test for a possible effect of incidental stimulation of the motor regions under Cz. No effect of tDCS on RTs was found. These findings strengthen the case for tDCS having real effects on cerebral information processing. However, these effects did not clearly arise from either of the two processing stages of the visual search process. We suggest that this is because tDCS has a DIFFUSE, pervasive action across the task-relevant neuroanatomical region(s), not a discrete effect in terms of information processing stages.

Control of influence of a thread on a bending of screws

International Nuclear Information System (INIS)

Proskuriakov, N E; Lopa, I V; Trapeznikov, E V

2017-01-01

The influence of the threads and the bending of screw on their moments of inertia of the cross section considered. This problem is actual since existing methods exclude from calculations the influence of supporting the thread, using as the basic geometrical parameter such as the internal diameter of the thread (diameter of cavities). Fundamental difference of a bend of the screw from a bend of a smooth rod consists that moment of inertia of the screw is a variable. It is shown that the change in cross-section moment of inertia along the length of the screw are essential and have periodic character. Analytical interrelation of the bending of the screw and the decreasing of moment of inertia of its cross section is established and equation describing this phenomenon is suggested. The greatest decrease of the moment of inertia occurs in the middle of the screw length, and the lowest - at its ends. Function and approximate coefficients for the main types of thread are proposed, which take into account this change. (paper)

Bioabsorbable metal screws in traumatology: A promising innovation

Directory of Open Access Journals (Sweden)

Roland Biber

2017-04-01

Full Text Available MAGNEZIX® CS (Syntellix AG, Hanover, Germany is a bioabsorbable compression screw made of a magnesium alloy (MgYREZr. Currently there are only two clinical studies reporting on a limited number of elective patients who received this screw in a hallux valgus operation. We applied MAGNEZIX® CS for fixation of distal fibular fracture in a trauma patient who had sustained a bimalleolar fracture type AO 44-B2.3. Clinical course was uneventful, fracture healing occurred within three months. Follow-up X-rays showed a radiolucent area around the implant for some months, yet this radiolucent area had disappeared in the 17-months follow-up X-ray. Keywords: Magnesium, Bioabsorbable, Compression screw, Osteosynthesis, Ankle fracture

Long-term clinical outcomes and survivorship of press-fit condylar sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients.

Science.gov (United States)

Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik; Kulkarni, Sourabh S; Kim, Yoon-Hong

2014-10-01

We are aware of no study that has compared press-fit condylar Sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients after more than ten years of follow-up. The purpose of the current study was to compare these two implants with respect to the functional and radiographic results, prevalence of osteolysis, and overall revision rates at a mean of 12.1 years of follow-up. The study consisted of a consecutive series of 444 patients (mean age [and standard deviation], 66.5 ± 7.4 years) who underwent simultaneous bilateral total knee arthroplasty, with one side treated immediately after the other. All of the patients received a press-fit condylar Sigma mobile-bearing prosthesis on one side and a press-fit condylar Sigma fixed-bearing prosthesis on the contralateral side. The minimum duration of follow-up was ten years (mean, 12.1 years; range, ten to thirteen years). At the time of each follow-up visit, the patients were assessed clinically and radiographically. Postoperative total knee scores (95 and 94 points), Western Ontario and McMaster Universities Osteoarthritis Index (19 and 18 points), University of California, Los Angeles activity score (both prostheses, 5 points), range of motion (129° ± 6.3° and 127° ± 6.8°), and radiographic findings did not differ significantly between the press-fit condylar Sigma mobile and fixed-bearing designs at the final follow-up. The prevalence of aseptic loosening (1.4% and 1.8%) did not differ significantly between the mobile and fixed-bearing implant designs. No knee in either group had osteolysis. The estimated survival rate with revision as the end point was 98.2% (95% confidence interval, 91% to 99%) and 97.5% (95% confidence interval, 91% to 99%) at 12.1 years for the mobile and fixed-bearing implant groups, respectively. The results of the present long-term clinical study suggest that excellent clinical and radiographic results were achieved with both the press-fit condylar Sigma mobile and

History of Retractor Technologies for Percutaneous Pedicle Screw Fixation Systems.

Science.gov (United States)

Mobbs, Ralph J; Phan, Kevin

2016-02-01

Minimally invasive techniques aimed at minimizing surgery-associated risk and morbidity of spinal surgery have increased in popularity in recent years. Their potential advantages include reduced length of hospital stay, blood loss, and requirement for post-operative analgesia and earlier return to work. One such minimally invasive technique is the use of percutaneous pedicle screw fixation, which is paramount for promoting rigid and stable constructs and fusion in the context of trauma, tumors, deformity and degenerative disease. Percutaneous pedicle screw insertion can be an intimidating prospect for surgeons who have only been trained in open techniques. One of the ongoing challenges of this percutaneous system is to provide the surgeon with adequate access to the pedicle entry anatomy and adequate tactile or visual feedback concerning the position and anatomy of the rod and set-screw construct. This review article discusses the history and evolution of percutaneous pedicle screw retractor technologies and outlines the advances over the last decade in the rapidly expanding field of minimal access surgery for posterior pedicle screw based spinal stabilization. As indications for percutaneous pedicle screw techniques expand, the nuances of the minimally invasive surgery techniques and associated technologies will also multiply. It is important that experienced surgeons have access to tools that can improve access with a greater degree of ease, simplicity and safety. We here discuss the technical challenges of percutaneous pedicle screw retractor technologies and a variety of systems with a focus on the pros and cons of various retractor systems. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

The Improvement of Bone-Tendon Fixation by Porous Titanium Interference Screw: A Rabbit Animal Model.

Science.gov (United States)

Tsai, Pei-I; Chen, Chih-Yu; Huang, Shu-Wei; Yang, Kuo-Yi; Lin, Tzu-Hung; Chen, San-Yuan; Sun, Jui-Sheng

2018-05-04

The interference screw is a widely used fixation device in the anterior cruciate ligament (ACL) reconstruction surgeries. Despite the generally satisfactory results, problems of using interference screws were reported. By using additive manufacturing (AM) technology, we developed an innovative titanium alloy (Ti 6 Al 4 V) interference screw with rough surface and inter-connected porous structure designs to improve the bone-tendon fixation. An innovative Ti 6 Al 4 V interference screws were manufactured by AM technology. In vitro mechanical tests were performed to validate its mechanical properties. Twenty-seven New Zealand white rabbits were randomly divided into control and AM screw groups for biomechanical analyses and histological analysis at 4, 8 and 12 weeks postoperatively; while micro-CT analysis was performed at 12 weeks postoperatively. The biomechanical tests showed that the ultimate failure load in the AM interference screw group was significantly higher than that in the control group at all tested periods. These results were also compatible with the findings of micro-CT and histological analyses. In micro-CT analysis, the bone-screw gap was larger in the control group; while for the additive manufactured screw, the screw and bone growth was in close contact. In histological study, the bone-screw gaps were wider in the control group and were almost invisible in the AM screw group. The innovative AM interference screws with surface roughness and inter-connected porous architectures demonstrated better bone-tendon-implant integration, and resulted in stronger biomechanical characteristics when compared to traditional screws. These advantages can be transferred to future interference screw designs to improve their clinical performance. The AM interference screw could improve graft fixation and eventually result in better biomechanical performance of the bone-tendon-screw construct. The innovative AM interference screws can be transferred to future

Two new chroman derivations from the endophytic Penicillium sp. DCS523.

Science.gov (United States)

Li, Jun-Tian; Fu, Xiao-Li; Tan, Chun; Zeng, Ying; Wang, Qi; Zhao, Pei-Ji

2011-01-18

Strain DCS523 was isolated from the branch tissue of Daphniphyllum longeracemosum and determined to be a Penicillium sp. according to the ITS sequence analysis. The extracts from the PDA solid fermentation media of Penicillium sp. DCS523 were purified to give two new chroman derivatives as well as six known compounds. Based on their spectral data the new compounds were identified as (Z)-6-acetyl- 3-(1,2-dihydroxypropylidene)-5-hydroxy-8-methylchroman-2-one and 6-acetyl-2α,5- dihydroxy-2-(2-hydroxypropyl)- 3α,8-dimethylchroman, respectively.

Hitachi's proposed DCS solution for new build CANDU EC6 using the G-HIACS unified platform

Energy Technology Data Exchange (ETDEWEB)

Tan, D.; Ishii, K.; Otsuka, Y.; Uemura, K., E-mail: daisuke.tan.ye@hitachi.com [Hitachi Ltd., Infrastructure Systems Co., Ibaraki (Japan); Marko, P.E. [Hitachi Power Systems Canada Ltd., Power and Industry Div., Ontario (Canada)

2013-07-01

Hitachi Ltd. has developed the safe and secure functional safety DCS controller for potential new build NPP projects in the global market. Hitachi has improved the availability, maintainability, and reliability for its latest DCS systems named G-HIACS. In this latest paper on its DCS product development program, Hitachi would like to report a proposed DCS solution for new build CANDU NSP and BOP based on the G-HIACS Unified Architecture (R800FS/HSC800FS vSAFE Functional Safety Controller and R900/HSC900 General Purpose Controller) hybrid control system. (author)

Failure analysis of top nozzle holddown spring screw for nuclear fuel assembly

International Nuclear Information System (INIS)

Koh, S. K.; Ryu, C. H.; Na, E. G.; Baek, T. H.; Jeon, K. L.

2003-01-01

A failure analysis of holddown spring screw was performed using fracture mechanics approach. The spring screw was designed such that it was capable of sustaining the loads imposed by the initial tensile preload and operational loads. In order to investigate the cause of failure, a stress analysis of the top nozzle spring assembly was done using finite element analysis and a life prediction of the screw was made using a fracture mechanics approach. The elastic-plastic finite element analysis showed that the local stresses at the critical regions of head-shank fillet and thread root significantly exceeded than the yield strength of the screw material, resulting in local plastic deformation. Primary water stress corrosion cracking life of the Inconel 600 screw was predicted by using integration of the Scott model and resulted in 1.42 years, which was fairly close to the actual service life of the holddown spring screw

The Study of Vibration Processes in Oil Flooded Screw Compressors

Directory of Open Access Journals (Sweden)

I. V. Filippov

2014-01-01

Full Text Available Vibration processes that accompany most of machines and mechanisms are of interest to the researcher, as a source of information about the technical condition and the nature of the business processes flow. Vibration-based diagnostics of oil flooded screw compressors allows us to estimate the deviation of their operation from the main mode in accordance with changing the settings of vibration processes.The oil flooded screw compressor transition from the main mode of operation to the abnormal one is accompanied by complex gas-dynamic phenomena i.e. the initial gaps and their decays. This leads to changes in the nature of vibration processes, prompting suggestions that there is a relationship to a change of vibration parameters and mode of compressor operation.Studies were conducted by combined method using an analytical calculation of the decay parameters of the initial discontinuity and an experimental one based on the measurement of acceleration on the body of the real oil flooded screw compressor. A virtually adequate reaction of the decay parameters of the initial gap and the peak values of vibration acceleration to the change of operation mode of oil flooded screw compressor has been received. The peak value of the vibration acceleration was selected by the method of Gating being time-coinciding with the beginning discharge phase of the oil flooded screw compressor, and therefore, with the decay time of the initial discontinuity.This indicates a large degree of hypothesis likelihood on an existing initial break in oil flooded screw compressor when operating in abnormal conditions. This work contains the study results of vibration processes and their relationship to the operating mode of the oil flooded screw compressor, which distinguish it from the other works studied vibration processes in reciprocating compressors. The vibration parameters control of operating oil flooded screw compressor allows us to create an automatic capacity control

Test-retest reliability of prefrontal transcranial Direct Current Stimulation (tDCS) effects on functional MRI connectivity in healthy subjects.

Science.gov (United States)

Wörsching, Jana; Padberg, Frank; Helbich, Konstantin; Hasan, Alkomiet; Koch, Lena; Goerigk, Stephan; Stoecklein, Sophia; Ertl-Wagner, Birgit; Keeser, Daniel

2017-07-15

Transcranial Direct Current Stimulation (tDCS) of the prefrontal cortex (PFC) can be used for probing functional brain connectivity and meets general interest as novel therapeutic intervention in psychiatric and neurological disorders. Along with a more extensive use, it is important to understand the interplay between neural systems and stimulation protocols requiring basic methodological work. Here, we examined the test-retest (TRT) characteristics of tDCS-induced modulations in resting-state functional-connectivity MRI (RS fcMRI). Twenty healthy subjects received 20minutes of either active or sham tDCS of the dorsolateral PFC (2mA, anode over F3 and cathode over F4, international 10-20 system), preceded and ensued by a RS fcMRI (10minutes each). All subject underwent three tDCS sessions with one-week intervals in between. Effects of tDCS on RS fcMRI were determined at an individual as well as at a group level using both ROI-based and independent-component analyses (ICA). To evaluate the TRT reliability of individual active-tDCS and sham effects on RS fcMRI, voxel-wise intra-class correlation coefficients (ICC) of post-tDCS maps between testing sessions were calculated. For both approaches, results revealed low reliability of RS fcMRI after active tDCS (ICC (2,1) = -0.09 - 0.16). Reliability of RS fcMRI (baselines only) was low to moderate for ROI-derived (ICC (2,1) = 0.13 - 0.50) and low for ICA-derived connectivity (ICC (2,1) = 0.19 - 0.34). Thus, for ROI-based analyses, the distribution of voxel-wise ICC was shifted to lower TRT reliability after active, but not after sham tDCS, for which the distribution was similar to baseline. The intra-individual variation observed here resembles variability of tDCS effects in motor regions and may be one reason why in this study robust tDCS effects at a group level were missing. The data can be used for appropriately designing large scale studies investigating methodological issues such as sources of variability and

Effects of transcranial direct current stimulation (tDCS) on multiscale complexity of dual-task postural control in older adults.

Science.gov (United States)

Zhou, Diange; Zhou, Junhong; Chen, Hu; Manor, Brad; Lin, Jianhao; Zhang, Jue

2015-08-01

Transcranial direct current stimulation (tDCS) targeting the prefrontal cortex reduces the size and speed of standing postural sway in younger adults, particularly when performing a cognitive dual task. Here, we hypothesized that tDCS would alter the complex dynamics of postural sway as quantified by multiscale entropy (MSE). Twenty healthy older adults completed two study visits. Center-of-pressure (COP) fluctuations were recorded during single-task (i.e., quiet standing) and dual-task (i.e., standing while performing serial subtractions) conditions, both before and after a 20-min session of real or sham tDCS. MSE was used to estimate COP complexity within each condition. The percentage change in complexity from single- to dual-task conditions (i.e., dual-task cost) was also calculated. Before tDCS, COP complexity was lower (p = 0.04) in the dual-task condition as compared to the single-task condition. Neither real nor sham tDCS altered complexity in the single-task condition. As compared to sham tDCS, real tDCS increased complexity in the dual-task condition (p = 0.02) and induced a trend toward improved serial subtraction performance (p = 0.09). Moreover, those subjects with lower dual-task COP complexity at baseline exhibited greater percentage increases in complexity following real tDCS (R = -0.39, p = 0.05). Real tDCS also reduced the dual-task cost to complexity (p = 0.02), while sham stimulation had no effect. A single session of tDCS targeting the prefrontal cortex increased standing postural sway complexity with concurrent non-postural cognitive task. This form of noninvasive brain stimulation may be a safe strategy to acutely improve postural control by enhancing the system's capacity to adapt to stressors.

Analysis of Material Flow in Screw Extrusion of Aluminum

International Nuclear Information System (INIS)

Haugen, Bjoern; Oernskar, Magnus; Welo, Torgeir; Wideroee, Fredrik

2010-01-01

Screw extrusion of aluminum is a new process for production of aluminum profiles. The commercial potential could be large. Little experimental and numerical work has been done with respect to this process.The material flow of hot aluminum in a screw extruder has been analyzed using finite element formulations for the non-Newtonian Navier-Stokes equations. Aluminum material properties are modeled using the Zener-Holloman material model. Effects of stick-slip conditions are investigated with respect to pressure build up and mixing quality of the extrusion process.The numerical results are compared with physical experiments using an experimental screw extruder.

Consensus: "Can tDCS and TMS enhance motor learning and memory formation?"

Science.gov (United States)

Reis, Janine; Robertson, Edwin; Krakauer, John W; Rothwell, John; Marshall, Lisa; Gerloff, Christian; Wassermann, Eric; Pascual-Leone, Alvaro; Hummel, Friedhelm; Celnik, Pablo A; Classen, Joseph; Floel, Agnes; Ziemann, Ulf; Paulus, Walter; Siebner, Hartwig R; Born, Jan; Cohen, Leonardo G

2008-10-01

Noninvasive brain stimulation has developed as a promising tool for cognitive neuroscientists. Transcranial magnetic (TMS) and direct current (tDCS) stimulation allow researchers to purposefully enhance or decrease excitability in focal areas of the brain. The purpose of this paper is to review information on the use of TMS and tDCS as research tools to facilitate motor memory formation, motor performance and motor learning in healthy volunteers. Studies implemented so far have mostly focused on the ability of TMS and tDCS to elicit relatively short lasting motor improvements and the mechanisms underlying these changes have been only partially investigated. Despite limitations including the scarcity of data, work that has been already accomplished raises the exciting hypothesis that currently available noninvasive transcranial stimulation techniques could modulate motor learning and memory formation in healthy humans and potentially in patients with neurological and psychiatric disorders.

Investigation of tDCS volume conduction effects in a highly realistic head model

Science.gov (United States)

Wagner, S.; Rampersad, S. M.; Aydin, Ü.; Vorwerk, J.; Oostendorp, T. F.; Neuling, T.; Herrmann, C. S.; Stegeman, D. F.; Wolters, C. H.

2014-02-01

Objective. We investigate volume conduction effects in transcranial direct current stimulation (tDCS) and present a guideline for efficient and yet accurate volume conductor modeling in tDCS using our newly-developed finite element (FE) approach. Approach. We developed a new, accurate and fast isoparametric FE approach for high-resolution geometry-adapted hexahedral meshes and tissue anisotropy. To attain a deeper insight into tDCS, we performed computer simulations, starting with a homogenized three-compartment head model and extending this step by step to a six-compartment anisotropic model. Main results. We are able to demonstrate important tDCS effects. First, we find channeling effects of the skin, the skull spongiosa and the cerebrospinal fluid compartments. Second, current vectors tend to be oriented towards the closest higher conducting region. Third, anisotropic WM conductivity causes current flow in directions more parallel to the WM fiber tracts. Fourth, the highest cortical current magnitudes are not only found close to the stimulation sites. Fifth, the median brain current density decreases with increasing distance from the electrodes. Significance. Our results allow us to formulate a guideline for volume conductor modeling in tDCS. We recommend to accurately model the major tissues between the stimulating electrodes and the target areas, while for efficient yet accurate modeling, an exact representation of other tissues is less important. Because for the low-frequency regime in electrophysiology the quasi-static approach is justified, our results should also be valid for at least low-frequency (e.g., below 100 Hz) transcranial alternating current stimulation.

Decrease in Hydrogen Embrittlement Susceptibility of 10B21 Screws by Bake Aging

Directory of Open Access Journals (Sweden)

Kuan-Jen Chen

2016-08-01

Full Text Available The effects of baking on the mechanical properties and fracture characteristics of low-carbon boron (10B21 steel screws were investigated. Fracture torque tests and hydrogen content analysis were performed on baked screws to evaluate hydrogen embrittlement (HE susceptibility. The diffusible hydrogen content within 10B21 steel dominated the fracture behavior of the screws. The fracture torque of 10B21 screws baked for a long duration was affected by released hydrogen. Secondary ion mass spectroscopy (SIMS result showed that hydrogen content decreased with increasing baking duration, and thus the HE susceptibility of 10B21 screws improved. Diffusible hydrogen promoted crack propagation in high-stress region. The HE of 10B21 screws can be prevented by long-duration baking.

Towards unravelling reading-related modulations of tDCS-induced neuroplasticity in the human visual cortex

Directory of Open Access Journals (Sweden)

Andrea eAntal

2014-06-01

Full Text Available Stimulation using weak electrical direct currents has shown to be capable of inducing polarity dependent diminutions or elevations in motor and visual cortical excitability. The aim of the present study was to test if reading during transcranial direct current stimulation (tDCS is able to modify stimulation-induced plasticity in the visual cortex. Phosphene thresholds (PT in 12 healthy subjects were recorded before and after 10 minutes of anodal, cathodal and sham tDCS in combination with reading. Reading alone decreased PTs significantly, compared to the sham tDCS condition without reading. Interestingly, after both anodal and cathodal stimulation there was a tendency toward smaller PTs. Our results support the observation that tDCS-induced plasticity is highly dependent on the cognitive state of the subject during stimulation, not only in the case of motor cortex but also in the case of visual cortex stimulation.

The movement of screw dislocations in tungsten

International Nuclear Information System (INIS)

Tian Xiaogeng; Woo Chungho

2004-01-01

Using Acland potential for tungsten, the movement of 1/2a screw dislocation under shear stress was investigated by molecular dynamics simulation. Equilibrated core structure was obtained by relaxation of screw dislocation with proper boundary conditions. We found that the equilibrium dislocation core has three-fold symmetry and spread out in three direction on {1 1 0} planes. The screw dislocation core could not keep the original shape when the shear stress applied. The dislocation could not move until the shear stress became large enough. The dislocation moved in zigzag when the shear stress neared the Peierls stress. When the shear stress became larger, the dislocation moved in zigzag at the beginning and than moved almost in straight line in [2-bar11] direction. The large shear stress applied, the long distance moved before the dislocation stilled in z-direction and the large velocity in y-direction

Screw Remaining Life Prediction Based on Quantum Genetic Algorithm and Support Vector Machine

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Xiaochen Zhang

2017-01-01

Full Text Available To predict the remaining life of ball screw, a screw remaining life prediction method based on quantum genetic algorithm (QGA and support vector machine (SVM is proposed. A screw accelerated test bench is introduced. Accelerometers are installed to monitor the performance degradation of ball screw. Combined with wavelet packet decomposition and isometric mapping (Isomap, the sensitive feature vectors are obtained and stored in database. Meanwhile, the sensitive feature vectors are randomly chosen from the database and constitute training samples and testing samples. Then the optimal kernel function parameter and penalty factor of SVM are searched with the method of QGA. Finally, the training samples are used to train optimized SVM while testing samples are adopted to test the prediction accuracy of the trained SVM so the screw remaining life prediction model can be got. The experiment results show that the screw remaining life prediction model could effectively predict screw remaining life.

Ball Nut Preload Diagnosis of the Hollow Ball Screw through Support Vector Machine

Directory of Open Access Journals (Sweden)

Yi-Cheng Huang

2018-01-01

Full Text Available This paper studies the diagnostic results of hollow ball screws with different ball nut preload through the support vector machine (SVM process. The method is testified by considering the use of ball screw pretension and different ball nut preload. SVM was used to discriminate the hollow ball screw preload status through the vibration signals and servo motor current signals. Maximum dynamic preloads of 2%, 4%, and 6% ball screws were predesigned, manufactured, and conducted experimentally. Signal patterns with different preload features are separatedby SVM. The irregularity development of the ball screw driving motion current and rolling balls vibration of the ball screw can be discriminated via SVM based on complexity perception. The experimental results successfully show that the prognostic status of ball nut preload can be envisaged by the proposed methodology. The smart reasoning for the health of the ball screw is available based on classification of SVM. This diagnostic method satisfies the purposes of prognostic effectiveness on knowing the ball nut preload status

Finite element model predicts current density distribution for clinical applications of tDCS and tACS

Directory of Open Access Journals (Sweden)

Toralf eNeuling

2012-09-01

Full Text Available Transcranial direct current stimulation (tDCS has been applied in numerous scientific studies over the past decade. However, the possibility to apply tDCS in therapy of neuropsychiatric disorders is still debated. While transcranial magnetic stimulation (TMS has been approved for treatment of major depression in the United States by the Food and Drug Administration (FDA, tDCS is not as widely accepted. One of the criticisms against tDCS is the lack of spatial specificity. Focality is limited by the electrode size (35 cm2 are commonly used and the bipolar arrangement. However, a current flow through the head directly from anode to cathode is an outdated view. Finite element (FE models have recently been used to predict the exact current flow during tDCS. These simulations have demonstrated that the current flow depends on tissue shape and conductivity. Toface the challenge to predict the location, magnitude and direction of the current flow induced by tDCS and transcranial alternating current stimulation (tACS, we used a refined realistic FE modeling approach. With respect to the literature on clinical tDCS and tACS, we analyzed two common setups for the location of the stimulation electrodes which target the frontal lobe and the occipital lobe, respectively. We compared lateral and medial electrode configuration with regard to theirusability. We were able to demonstrate that the lateral configurations yielded more focused stimulation areas as well as higher current intensities in the target areas. The high resolution of our simulation allows one to combine the modeled current flow with the knowledge of neuronal orientation to predict the consequences of tDCS and tACS. Our results not only offer a basis for a deeper understanding of the stimulation sites currently in use for clinical applications but also offer a better interpretation of observed effects.

Locking screw-plate interface stability in carbon-fibre reinforced polyetheretherketone proximal humerus plates.

Science.gov (United States)

Hak, David J; Fader, Ryan; Baldini, Todd; Chadayammuri, Vivek B S

2017-09-01

Carbon-fibre reinforced polyetheretherketone (CFR-PEEK) plates have recently been introduced for proximal humerus fracture treatment. The purpose of this study was to compare the locking screw-plate interface stability in CFR-PEEK versus stainless steel (SS) proximal humerus plates. Locking screw mechanical stability was evaluated independently in proximal and shaft plate holes. Stiffness and load to failure were tested for three conditions: (1) on-axis locking screw insertion in CFR-PEEK versus SS plates, (2) on-axis locking screw insertion, removal, and reinsertion in CFR-PEEK plates, and (3) 10-degree off-axis locking screw insertion in CFR-PEEK plates. Cantilever bending at a rate of 1 mm/minute was produced by an Instron machine and load-displacement data recorded. Shaft locking screw load to failure was significantly greater in CFR-PEEK plates compared to SS plates (746.4 ± 89.7 N versus 596.5 ± 32.6 N, p PEEK plates (p PEEK plates. The mechanical stability of locking screws in CFR-PEEK plates is comparable or superior to locking screws in SS plates.

tDCS for Memory Enhancement: Analysis of the Speculative Aspects of Ethical Issues.

Science.gov (United States)

Voarino, Nathalie; Dubljević, Veljko; Racine, Eric