Reversal of Simple Hydrogenic Isotope Scaling Laws in Tokamak Edge Turbulence.

The role of nonadiabatic electrons in regulating the hydrogenic isotope-mass scaling of gyrokinetic turbulence in tokamak fusion plasmas is assessed in the transition from ion-dominated core transport regimes to electron-dominated edge transport regimes. We propose a new isotope-mass scaling law that describes the electron-to-ion mass-ratio dependence of turbulent ion and electron energy fluxes. The mass-ratio dependence arises from the nonadiabatic response associated with fast electron parallel motion and plays a key role in altering-and in the case of the DIII-D edge, favorably reversing-the naive gyro-Bohm scaling behavior. In the reversed regime hydrogen energy fluxes are larger than deuterium fluxes, which is the opposite of the naive prediction.

Role of Microtearing Turbulence in DIII-D High Bootstrap Current Fraction Plasmas.

We report on the first direct comparisons of microtearing turbulence simulations to experimental measurements in a representative high bootstrap current fraction (f_{BS}) plasma. Previous studies of high f_{BS} plasmas carried out in DIII-D with large radius internal transport barriers (ITBs) have found that, while the ion energy transport is accurately reproduced by neoclassical theory, the electron transport remains anomalous and not well described by existing quasilinear transport models. A key feature of these plasmas is the large value of the normalized pressure gradient, which is shown to completely stabilize conventional drift-wave and kinetic ballooning mode instabilities in the ITB, but destabilizes the microtearing mode. Nonlinear gyrokinetic simulations of the ITB region performed with the cgyro code demonstrate that the microtearing modes are robustly unstable and capable of driving electron energy transport levels comparable to experimental levels for input parameters consistent with the experimental measurements. These simulations uniformly predict that the microtearing mode fluctuation and flux spectra extend to significantly shorter wavelengths than the range of linear instability, representing significantly different nonlinear dynamics and saturation mechanisms than conventional drift-wave turbulence, which is also consistent with the fundamental tearing nature of the instability. The predicted transport levels are found to be most sensitive to the magnetic shear, rather than the temperature gradients more typically identified as driving turbulent plasma transport.

Formation of a High Pressure Staircase Pedestal with Suppressed Edge Localized Modes in the DIII-D Tokamak.

We observe the formation of a high-pressure staircase pedestal (≈16-20 kPa) in the DIII-D tokamak when large amplitude edge localized modes are suppressed using resonant magnetic perturbations. The staircase pedestal is characterized by a flattening of the density and temperature profiles in midpedestal creating a two-step staircase pedestal structure correlated with the appearance of midpedestal broadband fluctuations. The pedestal oscillates between the staircase and single-step structure every 40-60 ms, correlated with oscillations in the heat and particle flux to the divertor. Gyrokinetic analysis using the cgyro code shows that when the heat and particle flux to the divertor decreases, the pedestal broadens and the E×B shear at the midpedestal decreases, triggering a transport bifurcation from the kinetic ballooning mode (KBM) to trapped electron mode (TEM) limited transport that flattens the density and temperature profiles at midpedestal and results in the formation of the staircase pedestal. As the heat flux to the divertor increases, the pedestal narrows and the E×B shear at the midpedestal increases, triggering a back transition from TEM to KBM limited transport. The pedestal pressure increases during the staircase phase, indicating that enhanced midpedestal turbulence can be beneficial for confinement.

A monolateral TMJ replacement under intraoral endoscopic assistance for jaw osteomielitis: a modified approach.

Alloplastic replacement has become a valid treatment for TMJ endstage disease. The Alkayat and Bramley pre-auricular approach combined with the submandibular incision are the current surgical approaches for TMJ surgery. The present study shows a modified approach using intraoral endoscopic assistance. A female patient affected by jaw osteomielitis with condylar detachment was treated with total left TMJ alloplastic replacement combined with a right TMJ arthroplasty. No subamandibular incision was performed and, subsequently, the risks for permanent or temporary damage to the marginalis mandibulae nerve and surgical submandibular scar were avoided. Postoperative CT-Scan evidenced a good prosthesis position. No complications occurred after two years of follow-up.

Intrinsic rotation driven by non-Maxwellian equilibria in Tokamak plasmas.

The effect of small deviations from a Maxwellian equilibrium on turbulent momentum transport in tokamak plasmas is considered. These non-Maxwellian features, arising from diamagnetic effects, introduce a strong dependence of the radial flux of cocurrent toroidal angular momentum on collisionality: As the plasma goes from nearly collisionless to weakly collisional, the flux reverses direction from radially inward to outward. This indicates a collisionality-dependent transition from peaked to hollow rotation profiles, consistent with experimental observations of intrinsic rotation.

Computer-assisted implant surgery and immediate loading in edentulous ridges with dental fresh extraction sockets. Two years results of a prospective case series study.

INTRODUCTION: The two-stage surgical approach for implant placement first documented in 1977 by Brånemark, represents today the most used protocol for placing implants. AIM: Aim of this prospective case series study was to compare the clinical and radiological performance of 12 edentulous jaws treated with of a modified prosthetic and surgical protocol for 3D software planning, guided surgery, immediate loading of implants inserted in edentulous jaws and extraction sockets and restored with Cad-Cam Zirconia and titanium full arch frameworks. PATIENTS AND METHODS: This work was designed as a prospective case series study. Twelve patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 72 implants, Nobel Replace Tapered Groovy; Nobel Biocare AB, Goteborg, Sweden) 26 of which were inserted in fresh extraction sockets, were inserted. Outcome measures were implants survival, radiographic marginal bone-levels and bone remodeling, soft tissue parameters and complications. RESULTS: All patients reached 24 months follow-up, and no patients dropped out from the study. The cumulative survival rate was 100%; after 24 months mean marginal bone remodelling value was: 1.35 ± 0.25, mean PPD value was 2.75 ± 0.40 mm and mean BOP value was 3.8% ± 1.8%. Only minor prosthetic complications were recorded. CONCLUSIONS: These data seem to validate this surgical and prosthetic protocol with valid results when applied in selected cases.

Circumscribed myositis ossificans of the masseter muscle: report of a case.

Myositis Ossificans (MO) is an unusual pathological entity still largely unknown, characterized by dystrophic calcification leading to heterotopic ossification of intramuscular connective tissue. The masticatory muscles are exceptionally involved. Four distinct types of myositis ossificans have been described: MO Progressiva, which is a genetic disorder involving several muscular groups; MO Circumscripta, limited to a single muscle and generally due to calcification of an intramuscular haematoma following severe trauma and progressive ossification; MO Pseudo-malignant limited to soft tissue and not associated to any trauma; MO associated to paraplegia. A case of circumscribed myositis ossificans of the masseter muscle in a 62 years-old woman is reported.

Nevoid basal cell carcinoma syndrome (Gorlin-Goltz syndrome). Case report.

Gorlin-Goltz syndrome or nevoid basal cell carcinoma syndrome (NBCCS) comprises multiple basal cell carcinomas, keratocysts of the jaw, palmar/plantar pits, spine and rib anomalies, calcifications of the falx cerebri etc. The diagnosis is made according to clinical criteria (Kimonis Criteria) and genetic ones. We studied one family where father and then his sun resulted affected by each syndrome. Gorlin-Goltz syndrome is a rare disease diagnosed according to clinical criteria sometimes difficult to integrate. The family case we presented shows how you can get diagnosis even in older age and after numerous surgeries. Patients should be given special attention and therefore should be monitorized and need multidisciplinary treatments continued in time, even a trivial change of signs and symptoms may be an important indicator of a precipitating event which puts the patient's life under threat.

Multiple synchronous bilateral neoplasms of the parotid glands.

Abstract: In this paper we report the rare case of a patient who came to our attention with three synchronous Warthin tumours affecting both the right and left parotid glands. The patient was a 68-year-old female, heavy smoker, with a seven-year history of painless growing nodules in both pre-auricular areas. Left-sided subtotal parotidectomy and contralateral superficial parotidectomy were performed at two differ-ent surgical times. Multiple, simultaneous and bilateral Warthin tumours represent a rare pathological entity of the salivary glands. Careful preoperative examination and radiological evaluation of the salivary glands are critical for the early diagnosis of bilateral synchronous tumours.

Neoclassical transport including collisional nonlinearity.

In the standard δf theory of neoclassical transport, the zeroth-order (Maxwellian) solution is obtained analytically via the solution of a nonlinear equation. The first-order correction δf is subsequently computed as the solution of a linear, inhomogeneous equation that includes the linearized Fokker-Planck collision operator. This equation admits analytic solutions only in extreme asymptotic limits (banana, plateau, Pfirsch-Schlüter), and so must be solved numerically for realistic plasma parameters. Recently, numerical codes have appeared which attempt to compute the total distribution f more accurately than in the standard ordering by retaining some nonlinear terms related to finite-orbit width, while simultaneously reusing some form of the linearized collision operator. In this work we show that higher-order corrections to the distribution function may be unphysical if collisional nonlinearities are ignored.

Preliminary Results of Bone Regeneration in Oromaxillomandibular Surgery Using Synthetic Granular Graft.

Traumatic, neoplastic, inflammatory, or infective dental removal promotes a gradual resorption process of bone which leads to a "nonuse" atrophy of the alveolar ridges. Many techniques allows restoring an appropriate bone thickness, but nowadays the attention is focused on the use of natural or synthetic grafts. Numerous studies have been conducted to develop and test new synthetic materials. In this article, the authors report their experience using a synthetic bone substitute in combination with Platelet Rich Fibrin (PRF). This technique was applied in different zones of the maxillomandibular district. The procedure showed a very satisfying bone regeneration without important complications.

[Transposition of the great arteries with pulmonary valvular stenosis and intact interventricular septum. Discussion of management strategies with respect to one case]. / Transposition des gros vaisseaux avec sténose valvulaire pulmonaire à septum interventriculaire intact. Discussion des enjeux thérapeutiques à propos d'un cas.

The authors report the case of a neonate with transposition of the great arteries (TGA) with pulmonary stenosis (PS) and intact Interventricular septum. The child was born at full term without a prenatal diagnosis with cyanosis developing at the 12th hour. After emergency atrioseptostomy, detransposition was performed on the 6th day. Commissurotomy and shaving of the much thickened bicuspid pulmonary valve was also performed. The postoperative course was complicated by a non-compliant left ventricle. After two months, myocardial ischaemia and persistent obstruction of the outflow tract led to severe cardiac failure and the death of the child. TGA with PS and intact interventricular septum is a very rare cardiac malformation. The prognosis is closely related to the anatomy of the pulmonary valve and the impact on the left ventricle. The therapeutic options are complex and are discussed in relation to this case.

[Slide tracheoplasty in congenital tracheal stenosis]. / Hypoplasies trachéales complexes du nourrisson: extension des limites de la "Slide Tracheoplasty".

OBJECTIVES: Slide Tracheoplasty has progressively become the gold standard in the management of long-segment tracheal stenosis in children and infants. However, in certain situations this operation might become difficult and others techniques might be preferred. MATERIAL AND METHODS: Five patients, 1 to 6 month old had surgery by our team, for complex tracheal stenosis between 2001 and 2005. Tracheal hypoplasia was considered complex because it was associated to either: an acquired critical stenosis, a cricoid stenosis, a bronchial stenosis, a tracheal bronchus or associated to oesophageal atresia and severe tracheomalacia. All of them have been treated by a modified slide tracheoplasty. RESULTS: The postoperative status required an average of 15 days in ICU, including 8 days of ventilation. Two patients had laryngeal nerve injury. Medium term follow up (27 months) demonstrated no need for re-intervention, good potential growth and normal child activity. CONCLUSIONS: Slide tracheoplasty can provide good results in certain cases of severe and complex tracheal hypoplasia in infants.

Congenital mitral stenosis with or without associated defects: An evolving surgical strategy.

BACKGROUND: Congenital mitral stenosis (CMS) remains a surgical challenge, particularly when it is associated with other heart defects. As in other groups of heart defects, there is a trend toward early single-stage complete repair, but the optimal surgical approach remains unanswered. METHODS AND RESULTS: This study was designed to analyze the evolution of surgical strategies in patients with CMS and associated defects through single-stage and staged repair. Between 1980 and 1999, 72 children were operated on for congenital heart defects, including CMS. Preoperative transmitral gradient was 12.6+/-7 mm Hg. Preoperatively, all the patients were NYHA class III to IV. Thirteen patients had an isolated CMS; in 59, it was associated with other heart defects, mainly ventricular septal defect (n=28) or multilevel left ventricular obstruction (n=41). In this group of patients, 33 had a staged approach, and 26 had a single-stage approach. Early mortality was 12.5% (9 patients). There were no deaths in the isolated CMS and single-stage repair groups. Logistic regression revealed that early mortality was influenced by association with left ventricular outflow tract obstruction (P:<0.001) and by use of a staged approach (P:<0.01). There was no late mortality in isolated CMS; there were 2 late deaths in the group of single-stage repair and 6 late deaths in the staged approach group (P:<0.01). Reoperation was required in 24 patients, mainly for residual mitral valve dysfunction or residual left ventricular outflow tract obstruction. Including the reoperations, 10 patients received a prosthetic mitral valve. At 15 years after surgery, survival was 69.6+/-7.5%, freedom from reoperation was 70.8+/-6.3%, and freedom from mitral valve replacement was 69+/-6%. CONCLUSIONS: Surgery for isolated CMS gives excellent early and long-term results. In patients with associated heart defects, a single-stage operation seems superior to a staged approach. Mitral valve replacement in this category of patients should be reserved as a salvage procedure.

Coronary events after arterial switch operation for transposition of the great arteries.

BACKGROUND: Transfer of the coronary arteries is a crucial step during the arterial switch operation (ASO) for transposition of the great arteries. This retrospective study aims to assess the incidence and risk factors of coronary events after ASO and sensitivity of noninvasive tests in the diagnosis of the coronary obstruction. METHODS AND RESULTS: Between 1982 and 2001, 1304 newborn and infants had an ASO and the 1 198 hospital survivors had a 59-month mean follow-up. Coronary events occurred in 94 patients (7.2%; 95% CI, 6 to 9). Survival without coronary events were 92.7, 91, and 88.2% at 1, 10, and 15 years, respectively. The incidence was bimodal: high early and slow later. Multivariate analysis showed correlation with type B or C coronary pattern and major operative events (P<0.0001 and P=0.0024). In a subset of 324 patients who underwent a coronary artery angiography, lesions were observed in 22 patients (6.8%; 95% CI, 5 to 10). Multivariate analysis showed correlation with only type B or C coronary pattern (OR=20.8, P=0.0002). All of these patients had electrocardiogram and echocardiogram, 174 patients also had a treadmill test, and 115 patients had a myocardial scintigraphy. The association of these tests had the highest diagnosis sensitivity, 75%. CONCLUSIONS: After ASO, coronary events are not rare, occurring most often early and are an important cause of death. Coronary repair can be needed lately. Noninvasive tests are not sensitive enough to detect significant delayed coronary artery stenosis and coronary artery angiography should be performed.

Biventricular repair approach in ducto-dependent neonates with hypoplastic but morphologically normal left ventricle.

OBJECTIVES: Increased afterload and multilevel LV obstruction is constant. We assumed that restoration of normal loading conditions by relief of LV obstructions promotes its growth, provided that part of the cardiac output was preoperatively supported by the LV, whatever the echocardiographic indexes. BACKGROUND: Whether to perform uni- or biventricular repair in ducto dependent neonates with hypoplastic but morphologically normal LV (hypoplastic left heart syndrome classes II & III) remains unanswered. Echocardiographic criteria have been proposed for surgical decision. METHODS: Twenty ducto dependent neonates presented with this anomaly. All had aortic coarctation associated to multilevel LV obstruction. Preoperative echocardiographic assessment showed: mean EDLW of 12.4 +/- 3.03 ml/m2 and mean Rhodes score of -1.73 +/-0.8. Surgery consisted in relief of LV outflow tract obstruction by coarctation repair in all associated to aortic commissurotomy in one and ASD closure in 2. RESULTS: There were 3 early and 2 late deaths. Failure of biventricular repair and LV growth was obvious in patients with severe anatomic mitral stenosis. The other demonstrated growth of the left heart. At hospital discharge the EDLVV was 19.4+/-3.12 ml/m2 (p = 0.0001) and the Rhodes score was -0.38+/-1.01 (p = 0.0003). Actuarial survival and freedom from reoperation rates at 5 years were 72.5% and 46%, respectively. CONCLUSIONS: Biventricular repair can be proposed to ducto dependent neonates with hypoplastic but morphologically normal LV provided that all anatomical causes of LV obstruction can be relieved. Secondary growth of the left heart then occurs; however, the reoperation rate is high.

[Surgical repair of atrial septal defect in 1011 consecutive patients]. / Traitement chirurgical des communications interauriculaires chez 1011 patients consécutifs. Incidence des complications postopératoires précoces.

The immediate postoperative complications of 1011 consecutive patients undergoing surgical repair of atrial septal defects between 1980 and 1998 at Marie Lannelongue Hospital were analysedwith the ultimate objective of comparing their incidence with that of percutaneous closure. Five patients died (0.49%) of low cardiac output (N=3), pulmonary oedema (N=1) or pulmonary hypertension (N=1). A total of 356 patients (35.2%) had 448 postoperative complications. There were 77% minor and 23% major complications. The minor complications included arrhythmias and conduction defects (N=130), respiratory complications (N=90) and pericardial effusions (N=64). The main major complications were cardiac failure (N=27), cardiac tamponade (N=13), neurological complications (N=8) and reoperation (N=28). Of the survivors, 95.6% of patients were discharged from hospital with no residual problem and 41 (4.4%) had sequellae: arrhythmias (N=29, including one pacemaker implantation), neurological complications (N=4), acquired mitral regurgitation (N=2), phrenic nerve paralysis (N=1) and minimal residual shunt (N=10). Factors correlated with surgical morbidity were age, the severity of pulmonary hypertension, the type of atrial septal defect (less morbidity with ostium secundum defects), the presence of associated malformations, the surgical approach (less morbidity with the right postero-lateral thoracic approach). This study demonstrated the incompressible risk of open heart cardiac surgery. It will form a basis for a comparative study of the two modern methods of treating atrial septal defect: surgical and percutaneous closure.

Giant pleomorphic adenoma of the submandibular gland. Case report.

Salivary glands are sites for a great variety of tumors. The parotid gland is the most common site followed by the submandibular gland. The pleomorphic adenoma represents the 60-70% of all tumors involving the major salivary glands, while the submandibular gland is involved in 8% of cases. The pleomorphic adenoma of the submandibular gland is rare and can present difficulty in diagnosis. The heterogeneous histology, a possible malignant transformation, an incomplete capsule that can determine a recurrence, are the most important characteristics of pleomorphic adenoma. A complete surgical removal of the tumor is the treatment of choice. In the case presented, the mass showed an unusual vascularization and remarkable dimensions.

Surgical treatment of subaortic stenosis after biventricular repair of double-outlet right ventricle.

Out of 180 patients who underwent biventricular repair of double-outlet right ventricle between 1980 and 1995, 9 (5%) required reoperation because of subaortic stenosis. Two other patients who initially underwent operation elsewhere underwent reoperation at our institution because of subaortic stenosis. The median age at biventricular repair was 4 months. Repair consisted of tunnel construction from the left ventricle to the aorta in nine patients; the remaining two patients received an arterial switch operation with ventricular septal defect closure. Subaortic stenosis developed with time: the mean postoperative left ventricle-to-aorta gradient after repair was 10 +/- 19 mm Hg (range, 0 to 50 mm Hg) and became 84 +/- 27 mm Hg (range, 40 to 124 mm Hg) in a mean delay of 45 +/- 66 months (range, 1 to 213 months). At reoperation, the obstruction was caused by the protrusion of the inferior rim of the ventricular septal defect into the left ventricular outflow tract associated with subaortic hypertrophied muscle and membrane. The 11 patients underwent 15 reoperations. Surgical technique consisted of an extended septoplasty in 6 reoperations. In this technique an incision was made in the septal patch and was extended into the muscle toward the apex until a large opening of the left ventricular outflow pathway was obtained. A new patch was then secured to streamline the left ventricular outflow tract. None of the patients who underwent extended septoplasty had to undergo reoperation. There were no early or late deaths. At 115 +/- 85 months after biventricular repair, all patients were in New York Heart Association functional class I or II and the mean postoperative left ventricle-to-aorta gradient was 20 +/- 24 mm Hg (range, 0 to 60 mm Hg). We conclude that after biventricular repair of double-outlet right ventricle, the subaortic region is at risk for the development of stenosis. Surgical treatment adapted to the anatomy of the obstruction can offer good early and midterm results. It seems that an aggressive approach by an extended septoplasty avoids multiple reoperations.

Surgical treatment of subaortic stenosis: a seventeen-year experience.

OBJECTIVE: The aim of the study was to analyze the long-term results of subaortic stenosis relief and the risk factors associated with recurrence and reoperation. METHODS: One hundred sixty patients with subaortic stenosis underwent biventricular repair. Before the operation the mean left ventricle-aorta gradient was 80 +/- 35 mm Hg, 57 patients had aortic regurgitation, and 34 were in New York Heart Association functional class III or IV. Median age at repair was 10 years. For discrete subaortic stenosis (n = 120), 39 patients underwent isolated membranectomy, 67 underwent membranectomy with associated septal myotomy, and 14 underwent septal myectomy. Tunnel subaortic stenosis (n = 34) was treated by myotomy in 10 cases, myectomy in 12, septoplasty in 7, Konno procedure in 3, and apical conduit in 2. Aortic valve replacement was performed in 6 cases, mitral valve replacement in 2 cases, and mitral valvuloplasty in 4 cases. RESULTS: There were 5 early (3.1%) and 4 late (4.4%) deaths. Within 3.6 +/- 3.3 years a recurrent gradient greater than 30 mm Hg was found in 42 patients (27%), 20 of whom had 26 reoperations. According to multivariable Cox regression analysis survival was influenced by hypoplastic aortic anulus (P =.01) and mitral stenosis (P =.048); recurrence and reoperation were influenced by coarctation and immediate postoperative left ventricular outflow tract gradients. At a median follow-up of 13.3 years, mean left ventricle-aorta gradient was 20 +/- 13 mm Hg. Relief of the subaortic stenosis improved the degree of aortic regurgitation in 86% of patients with preoperative aortic regurgitation. Actuarial survival and freedom from reoperation rates at 15 years were 94% +/- 1.3% and 85% +/- 6%, respectively. CONCLUSION: Although surgical treatment provides good results, recurrence and reoperation are significantly influenced by previous coarctation repair and by the quality of initial relief of subaortic stenosis.