bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of an orthogonal parallel robot with redundant actuation as an earthquake simulator and its experiments
Authors: Zhang J , Gao F , Yu H , Zhao X
Published: October 2011

In this article, an orthogonal 6-degree-of-freedom (DOF) parallel robot with redundant actuation is studied as an earthquake motion simulator. Taking the practical simulation of earthquake waves into consideration, the general characteristics of natural earthquakes are analysed and complexity and variety of seismic waves, three-dimensional and multi-DOF movement, and strong devastating force are regarded as the three obvious features in this article. Based on the characteristics of this orthogonal 6-DOF parallel robot with redundant actuation and the features of earthquakes, the feasibility of using this parallel robot as an earthquake motion simulator is analysed from three aspects: orthogonal 6-DOF structure, decoupling feature, and redundant actuation module. In order to simulate an earthquake motion using this parallel robot, its inverse kinematics and dynamics models are derived. The control system of this earthquake simulator is developed based on the PXIbus development platform. The computed-torque control algorithm based on the inverse dynamics is used in the controller of this equipment. A typical three-directional earthquake motion, the El Centro earthquake, is simulated on the end-effector of this parallel robot by means of its mathematical models and control system. Three main motion parameters of simulated seismic waves, displacements, velocities, and accelerations, are measured, respectively, by laser tracker and acceleration sensors. The experimental results show this equipment is appropriate to be used as an earthquake simulator.
Optimal shape design of a floating body for minimal water wave forces
Authors: Lee D , Son I
Published: October 2011

Water waves are the most significant excitation source for floating vessels. The motion of floating vessels needs to be stable against a random water wave environment. In this study, the authors try to find an optimal shape for a floating body that gives minimal water wave excitation forces for a given water wave over a predefined frequency band. First, we propose a shape optimization formulation with a displacement constraint of which the objective function is to minimize water–structure interaction forces. For the calculation of water wave forces, high-order boundary-element analysis software is developed under an assumption of linear hydrodynamic potential theory. The analysis software is plugged into an optimization toolbox in MATLAB software in order to find the optimum under-water shape of the floating body. Two numerical examples are introduced to show the validity of the proposed optimization formulation: hemisphere and pontoon problems. Various shapes that give minimal heave and/or surge water-excitation forces are sought.
Numerical simulation of soot formation in a turbulent diffusion flame: comparison among three soot formation models
Authors: Sarlak R , Shams M , Ebrahimi R
Published: October 2011

Combustion and soot formation in a turbulent diffusion flame are simulated. Chemistry of combustion is treated with a detailed reaction mechanism that employs 49 species and 277 reactions. Turbulence is taken into account via the corrected k–ε model. Radiation heat transfer from flame is modelled by the P-1 model. An empirical model proposed by Khan and Greeves and two semi-empirical models proposed by Tesner and Lindstedt are used to simulate the soot formation in the flame. Khan and Greeves model showed to underpredict the maximum soot volume fraction. Nevertheless, the main shortcoming of Khan and Greeves model which undermines the applicability of this model to prediction of soot formation in turbulent diffusion flames is the inability to locate the highly sooting regions of the flame properly. Tesner model underpredicts the soot formation significantly, although the predicted shapes of the soot profiles are in accordance with the experimental measurements. Lindstedt model performs well in predicting both the maximum soot formation and the soot profile shapes in the chamber. Therefore, Lindstedt model can be considered as the most suitable model for the prediction of soot formation in turbulent diffusion flames.
Energy flow analysis and hybrid controller design for non-linear electromagnetic suspension
Authors: Huang K , Zhang Y-C , Zhang G-G , Yu F
Published: October 2011

In this paper, a mathematical model for the developed electromagnetic suspension actuator is established based on measured parameters and test data. A main/inner-loop control strategy is proposed for its active control and the inner loop undertakes the control of a three-phase motor by applying a hysteresis current control method to track the calculated signal by the main loop. With the simplification of the inner-loop control system, the achievable range of control current and energy flow states of the actuator are analysed. Then, owing to the non-linear damping characteristic of the actuator, a hybrid system model which involves real and integer variables is built up for the main loop and optimal control to improve vehicle ride comfort is carried out based on a model predictive control method. Simulations are carried out with bump impulse and random uneven road inputs and the results demonstrate that the electromagnetic suspension with the designed hybrid controller can improve vehicle ride comfort compared with a corresponding passive suspension while energy is consumed from the battery.
Effects of the exhaust gas recirculation rate and ambient gas temperature on the spray and combustion characteristics of soybean biodiesel and diesel
Authors: Wu Y , Huang R , Lee C F , Huang C
Published: October 2011

Experiments were conducted in a constant-volume combustion chamber to investigate the spray and combustion characteristics of soybean biodiesel (B100) and diesel (B0). The in-cylinder density was kept at 15 kg/m3 and the ambient oxygen concentrations of 21, 18, and 15 per cent were maintained to simulate no exhaust gas recirculation (EGR), medium EGR, and heavy EGR in diesel engines respectively. The ambient gas temperature was varied from 800 K to 1200 K. The in-cylinder pressure and heat release rate were measured and the liquid penetration, natural flame emission, and soot formation characteristics were studied via new optical diagnostics. The results show that the peak pressure decreases with increasing ambient gas temperature and decreasing oxygen concentration for B0, except that at the oxygen concentration of 15 per cent. For B100, a higher peak pressure is obtained at the oxygen concentration of 15 per cent as opposed to that of 18 per cent. A lower heat release rate is found for B100 at the oxygen concentrations of 21 per cent and 18 per cent compared to B0, while a higher value is shown at the oxygen concentration of 15 per cent. The liquid penetration increases with decreasing oxygen concentration and ambient gas temperature. As the oxygen concentration increases for B0 at the ambient gas temperature from 800 K to 1000 K, the integrated natural flame luminosity (INFL) increases, while at 1200 K, the INFL at the oxygen concentration of 15 per cent has the highest value. For B100, with increasing oxygen concentration, the INFL increases at 800 K and 900 K, but decreases at 1000 K and 1200 K. The total soot mass increases with decreasing oxygen concentration and the soot formation duration is longer at a lower oxygen concentration. B100 has a shorter soot formation duration and soot is dramatically reduced by burning B100. The peak soot mass for B100 at 1200 K is comparable to that for B0 at 800 K.
Performance of triangle method for evaluating energy loss in vehicle collisions
Authors: Vangi D , Begani F
Published: October 2011

The present study is aimed at the validation of the triangle method for evaluating energy loss in vehicle collisions. The validation of the method is performed under two different points of view: first, the ability of the method to provide correct energy loss values; this was done by comparing the method results to experimental and numerical crash tests; and second, the ability of the method to produce results with a low scatter, due to the uncertainty in input data; this was done by performing a sensitivity analysis. It is clearly demonstrated that the triangle method can be used to evaluating energy losses involved in car crashes.
Intervening for transforming: The horizon of action in the Clinic of Activity
Authors: Clot Yves , Kostulski Katia
Published: October 2011

The article provides an account of the theoretical and methodological principles of the interventionist approach called the Clinic of Activity. A case is presented of educators working within a youth judicial protection service in centers for emergency placement of minors. As an intervention, the case did not proceed as expected and could be regarded as a failure. Ultimately what was commissioned to be an intervention for developing the professional profile of the educators in the organization became an analysis of the organization’s institutional crisis. The diagnosis proposed by the interventionists was that the impersonal dimension of work—that is, its institutional features—was underdeveloped while at the same time personal defenses among educators were increasingly manifesting themselves as ways to indicate the unbearable crisis in the organization.
Fault diagnosis and estimation for near-space hypersonic vehicle with sensor faults
Authors: Shen Q , Jiang B , Cocquempot V
Published: October 2011

This paper addresses a practical issue in fault diagnosis and estimation for a near-space hypersonic vehicle (NSHV) with sensor faults. First, the Takagi–Sugeno (T–S) fuzzy model is established to represent the NSHV non-linear dynamics, and sliding mode observers (SMO) are designed to generate a bank of residuals. Then, a novel sensor fault model is proposed, which contains time-varying bias faults and time-varying gain faults. Further, based on the Lyapunov stability theory, novel fault diagnostic algorithms are given to estimate the sensor fault, which removes the two classical assumptions in existing works that the time derivative of the output errors should be known and that the system states should be bounded. In addition, a sufficient condition for the existence of SMO is derived in the sense of the Lyapunov stability theory, which can be easily solved by Matlab® LMI toolbox. Finally, simulation results are presented to demonstrate the efficiency of the proposed approach.
Vibration suppression using two-terminal flywheel. Part II: application to vehicle passive suspension
Authors: Li Chuan , Liang Ming , Wang Yixian , Dong Yutao
Published: October 2011

The two-terminal flywheel introduced in Part I is suggested to be attached in parallel to the suspension strut whose vibration suppression performance improvement is accordingly investigated in this paper. The passenger comfort, tire grip and suspension deflection are respectively taken as the vibration suppression indices to design the optimal parameters of the proposed and conventional passive suspensions. The optimal single-objective performances of both suspensions arecompared to each other in actual dynamic parameter ranges. Due to the three conflicting and non-commensurable performance objectives, the Chebyshev goal programming approach is subsequently applied to find a multi-objective compromise for a design case. The non-ideal factors of the inverse screw transmission mechanism, which is modeled in Part I, are also taken into consideration to discuss the influence on the vibration suppression performance. The resultsshow that, owing to the presence of the two-terminal flywheel, the proposed suspension employing this novel component significantly outperforms the conventional one in terms of both passenger comfort and tire grip, with practically identical suspension deflection performance.
Numerical insight into heat transfer and power losses in spinning EHD non-Newtonian point contacts
Authors: Doki-Thonon T , Fillot N , Vergne P , Morales Espejel G E
Published: October 2011

This article focuses on thermal effects and their consequences in elastohydrodynamically lubricated spinning non-Newtonian point contacts. The particular kinematics of spin is of major interest for the understanding of flange contact in bearings (also known as rib-roller end contact) as well as in the field of continuously variable transmission where energetic efficiency is directly related to spin. A versatile finite element thermal non-Newtonian model is presented and results in terms of pressure, film thickness, temperature, heat fluxes, friction, and power losses are discussed. As spin increases, the central and minimum film thicknesses decrease drastically, the contact temperature rises, and the shearing heat source increases. The heat fluxes are totally reorganized in terms of direction and intensity. Friction values in both longitudinal and transverse directions need to be completed with the calculation of the frictional torque due to spin to take into account the total power losses in the contact. This study intends to draw attention to the necessity of an energetic approach when dealing with spinning contacts.
Effects of bearing orientation on the static performance of micropolar lubricated lobe bearings
Authors: Rahmatabadi A D , Sefid M , Rashidi Meybodi R , Nekoeimehr M
Published: October 2011

In contrast to plain circular bearings, orientation of the lobe bearings with respect to a fixed load direction can influence the bearing performance characteristics. Expressing the lobe bearing orientation in terms of an angle, which in this study is referred to as bearing orientation angle, its effect on static performance characteristics of three types of micropolar lubricated lobe bearings is investigated. For this purpose, finite element method is adopted for numerical solution of the modified Reynolds equation. It is found that against the most common mode of the lobe bearing orientation, which is with the bearing orientation angle zero, performance of the lobe bearings can be improved by suitable selection of the bearing orientation angle. Also, lobe bearings with comparatively lesser number of lobes are more affected by the orientation angle.
Effect of time of day on walking capacity and self-reported fatigue in persons with multiple sclerosis: a multi-center trial
Authors: Feys P , Gijbels D , Romberg A , Santoyo C , Gebara B , de Noordhout B Maertens , Knuts K , Béthoux F , de Groot V , Vaney C , Dalgas U
Published: October 2011

Background: Many persons with multiple sclerosis (PwMS) report increased fatigue in the afternoon and evening compared with the morning. It is commonly accepted that physical capacity also decreases as time of day progresses, potentially influencing the outcomes of testing.

Objective: The objective of this article was to determine whether self-reported fatigue level and walking capacity are influenced by time of day in PwMS.

Methods: A total of 102 PwMS from 8 centers in 5 countries, with a diverse level of ambulatory dysfunction (Expanded Disability Status Scale [EDSS] <6.5), participated. Patients performed walking capacity tests and reported fatigue level at three different time points (morning, noon, afternoon) during 1 day. Walking capacity was measured with the 6-Minute Walk Test (6MWT) and the 10-m walk test performed at usual and fastest speed. Self-reported fatigue was measured by the Rochester Fatigue Diary (RFD). Subgroups with mild (EDSS 1.5–4.0, n = 53) and moderate (EDSS 4.5–6.5, n = 49) ambulatory dysfunction were formed, as changes during the day were hypothesized to depend on disability status.

Results: Subgroups had different degree of ambulatory dysfunction ( p < 0.001) but reported similar fatigue levels. Although RFD scores were affected by time of day with significant differences between morning and noon/afternoon ( p < 0.0001), no changes in walking capacity were found in any subgroup. Additional analyses on subgroups distinguished by diurnal change in self-reported fatigue failed to reveal analogous changes in walking capacity.

Conclusions: Testing of walking capacity is unaffected by time of day, despite changes in subjective fatigue.
Multivariable Model for Time to First Treatment in Patients With Chronic Lymphocytic Leukemia
Authors: Wierda William G. , O'Brien Susan , Wang Xuemei , Faderl Stefan , Ferrajoli Alessandra , Do Kim-Anh , Garcia-Manero Guillermo , Cortes Jorge , Thomas Deborah , Koller Charles A. , Burger Jan A. , Lerner Susan , Schlette Ellen , Abruzzo Lynne , Kantarjian Hagop M. , Keating Michael J.
Published: October 2011

Purpose

The clinical course for patients with chronic lymphocytic leukemia (CLL) is diverse; some patients have indolent disease, never needing treatment, whereas others have aggressive disease requiring early treatment. We continue to use criteria for active disease to initiate therapy. Multivariable analysis was performed to identify prognostic factors independently associated with time to first treatment for patients with CLL.

Patients and Methods

Traditional laboratory, clinical prognostic, and newer prognostic factors such as fluorescent in situ hybridization (FISH), IGHV mutation status, and ZAP-70 expression evaluated at first patient visit to MD Anderson Cancer Center were correlated by multivariable analysis with time to first treatment. This multivariable model was used to develop a nomogram—a weighted tool to calculate 2- and 4-year probability of treatment and estimate median time to first treatment.

Results

There were 930 previously untreated patients who had traditional and new prognostic factors evaluated; they did not have active CLL requiring initiation of treatment within 3 months of first visit and were observed for time to first treatment. The following were independently associated with shorter time to first treatment: three involved lymph node sites, increased size of cervical lymph nodes, presence of 17p deletion or 11q deletion by FISH, increased serum lactate dehydrogenase, and unmutated IGHV mutation status.

Conclusion

We developed a multivariable model that incorporates traditional and newer prognostic factors to identify patients at high risk for progression to treatment. This model may be useful to identify patients for early interventional trials.
Metastatic Pheochromocytoma/Paraganglioma Related to Primary Tumor Development in Childhood or Adolescence: Significant Link to SDHB Mutations
Authors: King Kathryn S. , Prodanov Tamara , Kantorovich Vitaly , Fojo Tito , Hewitt Jacqueline K. , Zacharin Margaret , Wesley Robert , Lodish Maya , Raygada Margarita , Gimenez-Roqueplo Anne-Paule , McCormack Shana , Eisenhofer Graeme , Milosevic Dragana , Kebebew Electron , Stratakis Constantine A. , Pacak Karel
Published: October 2011

Purpose

To present data on the high rate of SDHB mutations in patients with metastatic pheochromocytoma/paraganglioma whose initial tumor presentation began in childhood or adolescence.

Patients and Methods

From 2000 to 2010, 263 patients with pheochromocytoma/paraganglioma were evaluated through the National Institutes of Health (NIH), Bethesda, MD. Of the 263 patients, 125 patients were found to have metastatic disease; of these 125 patients, 32 patients presented with a tumor before 20 years of age. An additional 17 patients presented with a tumor before 20 years of age but demonstrated no development of metastatic disease. Genetic testing for mutations in the VHL, MEN, and SDHB/C/D genes was performed on patients without previously identified genetic mutations.

Results

Of the 32 patients who presented with metastatic disease and had their primary tumor in childhood or adolescence, sequence analysis of germline DNA showed SDHB mutations in 23 patients (71.9%), SDHD mutations in three patients (9.4%), VHL mutations in two patients (6.3%), and an absence of a known mutation in four patients (12.5%). The majority of these 32 patients (78.1%) presented with primary tumors in an extra-adrenal location.

Conclusion

The majority of patients with metastatic pheochromocytoma/paraganglioma who presented with a primary tumor in childhood/adolescence had primary extra-adrenal tumors and harbored SDHB mutations. Except for primary tumors located in the head and neck where SDHD genetic testing is advised, we recommend that patients who present with metastatic pheochromocytoma/paraganglioma with primary tumor development in childhood or adolescence undergo SDHB genetic testing before they undergo testing for other gene mutations, unless clinical presentation or family history suggests a different mutation.
Gemcitabine Plusnab-Paclitaxel Is an Active Regimen in Patients With Advanced Pancreatic Cancer: A Phase I/II Trial
Authors: Von Hoff Daniel D. , Ramanathan Ramesh K. , Borad Mitesh J. , Laheru Daniel A. , Smith Lon S. , Wood Tina E. , Korn Ronald L. , Desai Neil , Trieu Vuong , Iglesias Jose L. , Zhang Hui , Soon-Shiong Patrick , Shi Tao , Rajeshkumar N.V. , Maitra Anirban , Hidalgo Manuel
Published: October 2011

Purpose

The trial objectives were to identify the maximum-tolerated dose (MTD) of first-line gemcitabine plus nab-paclitaxel in metastatic pancreatic adenocarcinoma and to provide efficacy and safety data. Additional objectives were to evaluate positron emission tomography (PET) scan response, secreted protein acidic and rich in cysteine (SPARC), and CA19-9 levels in relation to efficacy. Subsequent preclinical studies investigated the changes involving the pancreatic stroma and drug uptake.

Patients and Methods

Patients with previously untreated advanced pancreatic cancer were treated with 100, 125, or 150 mg/m2nab-paclitaxel followed by gemcitabine 1,000 mg/m2on days 1, 8, and 15 every 28 days. In the preclinical study, mice were implanted with human pancreatic cancers and treated with study agents.

Results

A total of 20, 44, and three patients received nab-paclitaxel at 100, 125, and 150 mg/m2, respectively. The MTD was 1,000 mg/m2of gemcitabine plus 125 mg/m2of nab-paclitaxel once a week for 3 weeks, every 28 days. Dose-limiting toxicities were sepsis and neutropenia. At the MTD, the response rate was 48%, with 12.2 median months of overall survival (OS) and 48% 1-year survival. Improved OS was observed in patients who had a complete metabolic response on [18F]fluorodeoxyglucose PET. Decreases in CA19-9 levels were correlated with increased response rate, progression-free survival, and OS. SPARC in the stroma, but not in the tumor, was correlated with improved survival. In mice with human pancreatic cancer xenografts, nab-paclitaxel alone and in combination with gemcitabine depleted the desmoplastic stroma. The intratumoral concentration of gemcitabine was increased by 2.8-fold in mice receiving nab-paclitaxel plus gemcitabine versus those receiving gemcitabine alone.

Conclusion

The regimen of nab-paclitaxel plus gemcitabine has tolerable adverse effects with substantial antitumor activity, warranting phase III evaluation.
Incidence and Outcome of Male Breast Cancer: An International Population-Based Study
Authors: Miao Hui , Verkooijen Helena M. , Chia Kee-Seng , Bouchardy Christine , Pukkala Eero , Larønningen Siri , Mellemkjær Lene , Czene Kamila , Hartman Mikael
Published: October 2011

Purpose

Male breast cancer is a rare disease with an incidence rate less than 1% of that of female breast cancer. Given its low incidence, few studies have assessed risk and prognosis.

Methods

This population-based study, including 459,846 women and 2,665 men diagnosed with breast cancer in Denmark, Finland, Geneva, Norway, Singapore, and Sweden over the last 40 years, compares trends in incidence, relative survival, and relative excess mortality between the sexes.

Results

World standardized incidence rates of breast cancer were 66.7 per 105 person-years in women and 0.40 per 105 person-years in men. Women were diagnosed at a younger median age (61.7 years) than men (69.6 years). Male patients had a poorer 5-year relative survival ratio than women (0.72 [95% CI, 0.70 to 0.75] v 0.78 [95% CI, 0.78 to 0.78], respectively), corresponding to a relative excess risk (RER) of 1.27 (95% CI, 1.13 to 1.42). However, after adjustment for age and year of diagnosis, stage, and treatment, male patients had a significantly better relative survival from breast cancer than female patients (RER, 0.78; 95% CI, 0.62 to 0.97).

Conclusion

Male patients with breast cancer have later onset of disease and more advanced disease than female patients. Male patients with breast cancer have lower risk of death from breast cancer than comparable female patients.
Predictive Variables for the Successful Treatment of Trigeminal Neuralgia With Gamma Knife Radiosurgery
Authors: Marshall Kopriva , Chan Michael D. , McCoy Thomas P. , Aubuchon Adam C. , Bourland J. Daniel , McMullen Kevin P. , deGuzman Allan F. , Munley Michael T. , Shaw Edward G. , Tatter Stephen B. , Ellis Thomas L.
Published: October 2011

Background:

Gamma Knife radiosurgery (GKRS) has been reported to be an effective modality to treat trigeminal neuralgia.

Objective:

To determine predictive factors for the successful treatment of trigeminal neuralgia with GKRS.

Methods:

Between 1999 and 2008, 777 GKRS procedures for patients with trigeminal neuralgia were performed at our institution. Evaluable follow-up data were obtained for 448 patients. Median follow-up time was 20.9 months (range, 3–86 months). The mean maximum prescribed dose was 88 Gy (range, 80–97 Gy). Dosimetric variables recorded included dorsal root entry zone dose, pons maximum dose, dose to the petrous dural ridge, and cisternal nerve length.

Results:

By 3 months after GKRS, 86% of patients achieved Barrow Neurologic Institute I to III pain scores, with 43% of patients achieving a Barrow Neurologic Institute I pain score. Twenty-six percent of patients reported posttreatment facial numbness; 28% of patients reported a post-GKRS procedure for relapsed pain, and median time to next procedure was 4.4 years. Multivariate analysis revealed that the development of postsurgical numbness (odds ratio [OR], 2.76; P = .006) was the dominant factor predictive of efficacy. Longer cisternal nerve length (OR, 0.85; P = .005), prior radiofrequency ablation (OR, 0.35; P = .028), and diabetes mellitus (OR, 0.38; P = .013) predicted decreased efficacy. The mean dose delivered to the dorsal root entry zone dose in patients who developed facial numbness (57.6 Gy) was more than the mean dose (47.3 Gy) given to patients who did not develop numbness (P = .02).

Conclusion:

The development of post-GKRS facial numbness is a dominant factor that predicts for efficacy of GKRS. History of diabetes mellitus or previous radio-frequency ablation may portend worsened outcome.
The Silk Flow-Diverting Stent in the Endovascular Treatment of Complex Intracranial Aneurysms: Technical Aspects and Midterm Results in 24 Consecutive Patients
Authors: Tähtinen Olli I. , Manninen Hannu I. , Vanninen Ritva L. , Seppänen Janne , Niskakangas Tero , Rinne Jaakko , Keski-Nisula Leo
Published: October 2011

Background:

The flow-diverting stent is a new option in endovascular therapy specifically designed for the endovascular reconstruction of a segmentally diseased artery. The safety of flow-diverting stents is still equivocal.

Objective:

To evaluate the technical aspects, thromboembolic events, adjunctive therapies, and midterm results in patients with complex intracranial aneurysms treated with a flow-diverting stent (Silk; Balt Extrusion, Montmorency, France).

Methods:

We retrospectively examined angiographic images and clinical reports of 24 consecutive patients (29 stents) treated (n = 23) or attempted to treat (n = 1) with a flow-diverting device in 2 Finnish centers between March 2009 and October 2010.

Results:

The primary technical success rate was 67% (16/24). Adjunctive therapies were required in 6 (25%) patients, including 4 cases where intra-arterial abciximab was administered for the treatment of intraprocedural thromboembolic events. Technique-related complication rate and the 30-day mortality rate were each 4% (1/24). Follow-up imaging revealed 1 case of delayed in-stent thrombosis resulting in permanent disability of the patient, 1 asymptomatic occlusion, and 1 asymptomatic stenosis of the stented artery. Complete occlusion of the aneurysm with fully patent parent artery was observed in 16 of the 23 aneurysms (70%) where follow-up images were available.

Conclusion:

Many previously untreatable cerebral aneurysms may be successfully treated with the Silk flow-diverting stent, but the associated risk of thromboembolic events is justifiable only if conventional endovascular or surgical treatment options are not applicable. Perioperative thromboembolic events should be prepared for and treated without unnecessary delays because they frequently respond to adjunctive medical therapy.
Epilepsy Surgery of the Temporal Lobe in Pediatric Population: A Retrospective Analysis
Authors: Lopez-Gonzalez Miguel Angel , Gonzalez-Martinez Jorge Alvaro , Jehi Lara , Kotagal Prakash , Warbel Ann , Bingaman William
Published: October 2011

Background:

There is still some reluctance to refer pediatric patients for epilepsy surgery, despite evidence of success in retrospective series.

Objective:

To describe surgical experience and long-term outcome in pediatric temporal lobe epilepsy (TLE) at a single institution.

Methods:

Retrospective review of pediatric (<18-years-old) TLE patients who underwent surgery between November 1996 and December 2006 at Cleveland Clinic Epilepsy Center. Cox proportional hazard modeling was used to assess outcome predictors.

Results:

One hundred thirty pediatric patients met study criteria. Mean time between seizure onset and surgery was 6.3 years. Invasive evaluation was used in 32 patients (24.5%). Hippocampal sclerosis was present in 70 patients (53.8%), either alone or associated in dual pathology. The complication rate was 7%. The seizure-freedom rates at 1, 2, 5, and 12 years were 76%, 72%, 54%, and 41%, respectively (Kaplan-Meier). With the use of the Engel outcome classification, 98 (75.3%) patients were class I, 11 (8.5%) class II, 9 (7%) class III, and 12 (9.2%) were class IV at last follow-up. Only 4 (3.1%) patients underwent reoperations. Antiepileptic drugs (AEDs) were discontinued in 36 patients (28.3%) in a mean period of 18 months (SD ± 17 months; range, 6-102 months). Although left-sided resection, lower number of preoperative AED trials (≤4), and tumor pathology correlated with favorable seizure outcomes, extensive surgical resection remained the only significant outcome predictor after multivariate analysis (P = .007; HR = 0.13 [95% confidence interval 0.007–0.64]).

Conclusion:

Careful selection of surgical candidates by multidisciplinary evaluations is required. Long-term seizure control is achieved successfully with acceptable low complication rates.
Government Advertising and Media Coverage of Corruption Scandals
Authors: Tella Rafael Di , Franceschelli Ignacio
Published: October 2011

We construct measures of the extent to which the four main newspapers in Argentina report government corruption on their front page during the period 1998–2007 and correlate them with government advertising. The correlation is negative. The size is considerable—a one standard deviation increase in monthly government advertising is associated with a reduction in the coverage of the government's corruption scandals of 0.23 of a front page per month, or 18 percent of a standard deviation in coverage. The results are robust to the inclusion of newspaper, month, newspaper × president and individual-corruption scandal fixed effects, as well as newspaper × president specific time trends. (JEL D72, K42, L82, M37, O17)
Public Provision and Protection of Natural Resources: Groundwater Irrigation in Rural India
Authors: Sekhri Sheetal
Published: October 2011

This paper evaluates the effects of a public groundwater provision program on water tables in Northern India. I theorize that public provision leads to sustainable use of groundwater when the fixed costs for private well provision are high. I use village-level longitudinal data on aquifers and wells, and exploit the physical and technological limitations of surface pumps that generate a cost difference at a specific water depth to test this model. My findings suggest that public provision can be used as an alternative in scenarios where prohibitive monitoring costs might preclude the use of other regulatory approaches to prevent over-extraction. (JEL O13, O18, Q15, Q25, Q28, Q53, Q58)
Initially non-diagnostic ultrasound-guided fine needle aspiration cytology of thyroid nodules: value and management
Authors: Chung Jin , Youk Ji Hyun , Kim Jeong-Ah , Kwak Jin Young , Kim Eun-kyung , Ryu Young Hoon , Son Eun Ju
Published: October 2011

Background

Ultrasound (US)-guided fine needle aspiration cytology (FNAC) is an accurate, reliable, and simple method to identify a thyroid nodule as benign or malignant. However, non-diagnostic cytology results for thyroid nodules are a major limitation of US-guided FNAC.

Purpose

To investigate the incidence of thyroid cancer among cases with non-diagnostic results on FNAC and to provide suggestions for the management of thyroid nodules that are initially non-diagnostic by FNAC according to ultrasonographic findings.

Material and Methods

From July 2006 to December 2009, 10,317 thyroid nodules in 6684 consecutive patients underwent US-guided FNAC at our institute. Among these, 871 thyroid nodules (8.4%) were diagnosed as non-diagnostic on initial cytologic evaluation and 196 underwent a second or third FNAC. Twenty-seven thyroid nodules (18.9%) underwent surgery, while 116 thyroid nodules were cytologically confirmed as benign with no remarkable change on follow-up US were included. We retrospectively reviewed the US findings for a total of 143 thyroid nodules (123 benign nodules and 20 malignant nodules). The US features that we compared included composition, echogenicity, margin, calcifications, shape, and underlying echogenicity.

Results

In total, thyroid cancer was diagnosed in 20 nodules (14.0%). The size of the nodule was significantly associated with malignancy ( P < 0.05). Most of the sonographically probable benign nodules were found to be benign (97.6%). Suspicious nodules on US were thyroid cancer in 43.2% of cases. Marked hypoechogenicity, microlobulated or irregular margin, microcalcifications, and taller-than-wide shape were significant US findings that correlated with malignancy ( P < 0.05). The diagnostic performance of ultrasound for initially non-diagnostic thyroid nodules was as follows: sensitivity of 90.0%, specificity of 65.0%, positive predictive value of 29.5%, and negative predictive value of 97.6%.

Conclusion

In terms of management of thyroid nodules with non-diagnostic FNAC cytology, US evaluation is a feasible and useful method for predicting malignancy.
Calcium scoring in unenhanced and enhanced CT data of the aorta-iliacal arteries: impact of image acquisition, reconstruction, and analysis parameter settings
Authors: Komen N , Klitsie P , Hermans JJ , Niessen WJ , Kleinrensink GJ , Jeekel J , Lange JF
Published: October 2011

Background

Several studies have been published on the matter of abdominal aortic and iliac calcifications and the association to clinical entities such as diabetes mellitus and renal failure. However, comparing of these studies is questionable since quantification methods for atherosclerosis differ.

Purpose

To evaluate the effect of image acquisition settings, reconstruction parameters, and analysis methods on calcium quantification in the abdominal aorta.

Material and Methods

Calcium scores were retrospectively determined on standardized abdominal CT scans of 15 patients. Two researchers obtained calcium scores with 10 different lower thresholds (LT) (130, 145, 160, 175, 200, 300, 400, 500, 600, 1000) in CT scans with and without contrast enhancement, with slice thicknesses (ST) varying between 2.0-5.0 mm for the non-contrast-enhanced series and between 1.0-5.0 mm for the contrast-enhanced series. In addition calcium scores obtained with two convolution kernels (B10f, B20f) were compared. Inter-observer variability was calculated.

Results

Calcium scoring at higher STs is overestimated compared to smaller STs and this effect was more pronounced with increasing calcium loads. Concerning the convolution kernel, scores obtained with kernel B10f were overestimated compared to kernel B20f. Increase of LT resulted in a decrease of the calcium score and scoring in contrast-enhanced series resulted in higher scores compared to non-contrast-enhanced series. These effects are more apparent in patients with higher calcium loads. Calcium scoring reproducibility with the reference standard is limited for the aorta-iliac trajectory, whereas scoring with the remaining settings is reproducible.

Conclusion

Scores obtained with different settings cannot be compared. The inter-observer reproducibility was limited using the reference standard and practical difficulties were substantial. Scoring with higher LT, ST, and contrast enhancement is faster and has less practical difficulties.
Environmentally benign and effective syntheses of N-substituted carbamates via alcoholysis of disubstituted ureas over TiO2/SiO2 catalyst
Authors: Wang Liguo , Shang Jianpeng , Liu Shimin , Liu Lequan , Zhang Shiguo , Deng Youquan
Published: October 2011

Catalytic syntheses of cyclohexyl carbamates via alcoholysis of dicyclohexyl urea (DCU), which can be synthesized from CO2 and amines, were first investigated with low-molecular-weight alcohols, i.e., methanol, ethanol, butan-1-ol. TiO2/SiO2 catalyst was prepared by wet impregnation method using tetrabutyl titanate as titanium source. The catalyst was characterized by inductively coupled plasma/atomic emission spectroscopy (ICP/AES), N2 adsorption, X-ray diffraction (XRD), field emission/scanning electron microscopy (FE/SEM), transmission electron microscopy TEM), and NH3/temperature-programmed desorption (TPD) in detail. TiO2/SiO2 with 5 wt % loadings and calcination at 600 °C exhibited better catalytic activity, and excellent yields of >95 % with 98 % selectivities for desired carbamates were achieved. Accordingly, the strong acidity was considered to be responsible for its superior activity. Moreover, the catalytic activity can essentially be preserved during the recycling tests. The scope was also expanded to synthesize other alkyl or aryl carbamates via alcoholysis of the corresponding disubstituted ureas, and 94 % yields with 96 % selectivities can be achieved. It provided a good candidate for the organic carbamates syntheses via a phosgene/halogen-free and effective route.
gem-Dibromocyclopropanes and enzymatically derived cis-1,2-dihydrocatechols as building blocks in alkaloid synthesis
Authors: Banwell Martin G. , Gao Nadia Yuqian , Ma Xinghua , Petit Laurent , White Lorenzo V. , Schwartz Brett D. , Willis Anthony C. , Cade Ian A.
Published: October 2011

The application of the title building blocks, the 6,6-dibromobicyclo[3.1.0]hexanes and the cis-1,2-dihydrocatechols, to the total synthesis of crinine and lycorinine alkaloids is described.
Mechanical properties of biomorphic silicon carbide ceramics
Authors: Gordic M.V. , Babic B.M. , Stasic J.M. , Trtica M.S. , Volkov-Husovic T. , Posarac M.B. , Matovic B.Z.
Published: October 2011

Biomorphous ?-SiC ceramics were produced from linden wood by impregnation
with tetraethyl orthosilicate (TEOS), followed pyrolysis and high temperature
treatment at 1580?C. Six specimen groups included charcoal and five groups
with different number of impregnation were analyzed. Flexural and
compressional strength of charcoal and woodlike SiC ceramic were
characterized using three-point and compression testing. Mechanicall
properties increased slightly with number of impregnation cycles. Ultrasonic
pulse velocity testing (UPVT) was used to determine dynamic young modulus of
elasticity. Laser surface modification was studied by interaction with Nd:YAG
laser, operating at 1064 or 532 nm wavelengthss and pulse duration of 150 ps.
Reformulation of Current Recommendations for Target Serum Lithium Concentration According to Clinical Indication, Age and Physical Comorbidity
Authors: Wijeratne Chanaka , Draper Brian
Published: October 2011

Background: There have been significant changes in the nature of psychiatric patient populations and patterns of drug prescribing in mood disorders since serum lithium monitoring was introduced. It seems opportune to review current guidelines for target lithium concentration given the decline in lithium monotherapy and increase in the numbers of older people and those with comorbid physical disease administered lithium.

Method: A review was made of the literature of lithium monitoring and target serum concentration in mood disorders, older people, and comorbid physical illness.

Results: Current guidelines, which generally recommend a target serum concentration of 0.5/0.6 to 1.1/1.2 mmol/L, have a number of limitations. A target lithium level of > 0.8 mmol/L is inappropriate given poor tolerability, and adequate efficacy when combination lithium-antipsychotic therapy is used at this or lower levels. Guidelines have largely failed to match specific clinical indications to serum levels, and to consider comorbid physical illness factors known to be associated with lithium toxicity.

Conclusion: For most patients, a target serum lithium concentration range of 0.5–0.8 mmol/L, varying according to clinical indication, age and concurrent physical status, seems most appropriate in enhancing efficacy and minimizing adverse effects. The lower end of this range (0.5–0.6 mmol/L) is recommended for patients 50 years and over; those with diabetes insipidus, renal impairment or thyroid dysfunction; those administered diuretics, angiotensin converting enzyme (ACE) inhibitors or non-steroidal anti-inflammatory drugs (NSAIDs)/COX-2 inhibitors; and in the prophylaxis of bipolar depression and management of acute unipolar depression. The higher end of this range (0.7–0.8 mmol/L) is recommended in the management of acute mania and prophylaxis of mania.
Another Journal on Mathematical Logic and Mathematical Physics?
Authors: Garrido Angel
Published: October 2011

It is my great pleasure to welcome you to Axioms: Mathematical Logic and Mathematical Physics, a new open access journal, which is dedicated to the foundations (structure and axiomatic basis, in particular) of mathematical and physical theories, not only on crisp or strictly classical sense, but also on fuzzy and generalized sense. This includes the more innovative current scientific trends, devoted to discover and solving new, defying problems. Our new journal does not try to be the same as those journals already dedicated to this field. Below we highlight what makes Axioms: Mathematical Logic and Mathematical Physics different. [...]
Anti-Ro/SSA Antibodies Are an Independent Factor Associated with an Insufficient Response to Tumor Necrosis Factor Inhibitors in Patients with Rheumatoid Arthritis
Authors: MATSUDAIRA RAN , TAMURA NAOTO , SEKIYA FUMIO , OGASAWARA MICHIHIRO , YAMANAKA KENJIRO , TAKASAKI YOSHINARI
Published: October 2011

Objective.

To study the significance of anti-Ro/SSA antibodies (anti-Ro) in the clinical response to tumor necrosis factor (TNF) inhibitors in patients with rheumatoid arthritis (RA).

Methods.

The clinical responses of a cohort of 190 patients with RA who were treated with infliximab, etanercept, or adalimumab (n = 112, 64, and 14, respectively) as the first biologics were examined using the Disease Activity Score in 28 joints (DAS28) at 24 weeks and the discontinuation rate at 56 weeks. The baseline characteristics of responders and the nonresponders were compared. The clinical response was compared between anti-Ro-negative and -positive patients. The factors associated with the inefficiency of TNF inhibitors were estimated with a multivariable logistic regression analysis.

Results.

The positive rate of anti-Ro was significantly higher in patients with no European League Against Rheumatism (EULAR) response at 24 weeks (OR 3.64, 95% CI 1.45–9.01, p = 0.003). In anti-Ro-positive patients, a moderate or good EULAR response rate was significantly lower with a sustaining higher median DAS28 (p = 0.006), and this difference was greater among infliximab-treated patients. The discontinuation rate for TNF inhibitors due to inefficacy at 56 weeks was also higher in anti-Ro-positive patients (OR 4.68, 95% CI 1.82–11.99, p = 0.0005), and 75% of these patients received infliximab. The presence of anti-Ro was strongly associated with no EULAR response at 24 weeks and a higher discontinuation rate of TNF inhibitors by 56 weeks (OR 5.22, 95% CI 1.75–15.57, p = 0.003 and OR 10.18, 95% CI 2.18–49.56, p = 0.003).

Conclusion.

The presence of anti-Ro might be related to the lesser clinical response to infliximab compared to other TNF inhibitors, suggesting that the presence of anti-Ro should be considered when choosing the appropriate biologics for patients with RA.
Analysis of the Validation Status of Quality of Life and Functional Disability Measures in Pulmonary Arterial Hypertension Related to Systemic Sclerosis: Results of a Systematic Literature Analysis by the Expert Panel on Outcomes Measures in Pulmonary Arterial Hypertension Related to Systemic Sclerosis (EPOSS)
Authors: KOWAL-BIELECKA OTYLIA , AVOUAC JEROME , PITTROW DAVID , HUSCHER DOERTE , BEHRENS FRANK , DENTON CHRISTOPHER P. , FOELDVARI IVAN , HUMBERT MARC , MATUCCI-CERINIC MARCO , NASH PETER , OPITZ CHRISTIAN F. , RUBIN LEWIS J. , SEIBOLD JAMES R. , STRAND VIBEKE , FURST DANIEL E. , DISTLER OLIVER
Published: October 2011

Objective.

We aimed to assess the current validity status of the Health Assessment Questionnaire–Disability Index (HAQ-DI) and the 36-item Medical Outcomes Study Short Form Health Survey (SF-36).

Methods.

Studies using HAQ-DI and/or SF-36 in patients with pulmonary arterial hypertension (PAH) associated with systemic sclerosis (PAH-SSc) were identified through a systematic literature review and assessed according to the Outcome Measures in Rheumatology Clinical Trials (OMERACT) consensus group criteria.

Results.

Both HAQ-DI and SF-36 were considered credible (having face validity) and feasible. Based on expert opinion, neither HAQ-DI nor SF-36 was specific for PAH-SSc since their results may be influenced by other aspects of SSc (judged “unclear” with respect to the content validity criterion). In the overall SSc population, there was significant albeit weak correlation between physical component SF-36 scores and pulmonary artery systolic pressure (PASP) by echocardiography (Kendall tau b = −0.2, p < 0.01). Although HAQ-DI also correlated with PASP by echocardiography, there were no significant correlations in SSc patients with PAH proven by right heart catheterization between changes in HAQ-DI over time and changes in other PAH measures including 6-min walk distance (r = −0.04, p = 0.86), expert global assessment (r = 0.06, p = 0.97), and New York Heart Association functional class (r = 0.38, p = 0.39), indicating lack of construct validity for HAQ-DI in PAH-SSc. No studies enabling assessment of criterion validity or discrimination of HAQ-DI or SF-36 in PAH-SSc could be identified.

Conclusion.

Further validation of HAQ and SF-36 in PAH-SSc is needed. Alternatively, more specific assessments for functional disability or quality of life in PAH-SSc might be required.