bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deep brain stimulation of the ventral intermediate nucleus of the thalamus in medically refractory orthostatic tremor: Preliminary observations
Authors: Espay Alberto J. , Duker Andrew P. , Chen Robert , Okun Michael S. , Barrett Edwin T. , Devoto Johnna , Zeilman Pamela , Gartner Maureen , Burton Noël , Miranda Helard A. , Mandybur George T. , Zesiewicz Theresa A. , Foote Kelly D. , Revilla Fredy J. 
Published: August 2008

AbstractOrthostatic tremor (OT) is a disabling movement disorder associated with postural and gait impairment in the elderly. Medical therapy often yields insufficient benefit. We report the clinical and electrophysiological data on two patients with medication‐refractory OT treated with deep brain stimulation of the ventral intermediate thalamic nucleus (Vim DBS). Patient 1 underwent bilateral deep brain stimulation (DBS) and Patient 2 unilateral Vim DBS following 28 and 30 years of disease duration, respectively. Both patients showed increased latency to symptom onset after rising from a seated position, improved tolerance for prolonged standing, and slower crescendo of tremor severity when remaining upright. Postoperative evaluation demonstrated decreased amplitude of electromyographic activity with persistence of well‐defined oscillatory behavior showing strong coherence at 15 Hz between all muscles tested in the upper and lower limbs. Postural sway was unchanged. Clinical benefits have been sustained for over 18 months in Patient 1, and receded after 3 months in Patient 2. These findings support the consideration of bilateral Vim DBS implantation as a therapeutic option in patients with medically refractory OT. Further efficacy studies on chronic stimulation to disrupt the abnormal oscillatory activity in this disorder are warranted. © 2008 Movement Disorder Society
Case series of painful legs and moving toes: Clinical and electrophysiologic observations
Authors: Alvarez Maria V. , Driver‐Dunckley Erika E. , Caviness John N. , Adler Charles H. , Evidente Virgilio Gerald H. 
Published: August 2008

AbstractWe present a retrospective review of cases of painful legs and moving toes (PLMT) syndrome. Out of 4,780 database patients with movement disorders diagnosed at Mayo Clinic Arizona from 1996 to 2006, we identified 14 cases of PLMT and its variants (6 men, 8 women). Ages ranged from 25 to 84 years (mean, 69 years). Movements were bilateral in 12 and unilateral in 2. Pain preceding the movements was most commonly burning; movements consisted of flexion/extension, abduction/adduction, fanning, or clawing of toes, fingers, and sometimes the foot or hand. The most common predisposing factors were neuropathy and radiculopathy. Surface electromyography showed movements suggestive of both chorea and dystonia. Movements were partially suppressible and were diminished but still apparent during light sleep. GABAergic agents were most effective in controlling the pain and the movements. © 2008 Movement Disorder Society
Subthalamic nucleus stimulation restores corticospinal facilitation in Parkinson's disease
Authors: Pötter‐Nerger Monika , Ilic Tihomir V. , Siebner Hartwiq R. , Deuschl Günther , Volkmann Jens 
Published: August 2008

AbstractWe have previously shown that in patients with Parkinson's disease (PD), high‐frequency stimulation (HFS) of the subthalamic nucleus (STN) modifies spinal excitability via subcortical reticulospinal routes. To investigate whether STN‐HFS also modifies spinal excitability via transcortical routes in PD, 10 patients with PD (9 men, 1 woman; 58.3 ± 8.3 years) were investigated in the medical OFF‐state with or without STN‐HFS. The H‐reflex of the right soleus muscle was recorded during slight plantar flexion at 20% of maximum force. A conditioning transcranial stimulus was applied at 95% of active motor threshold to the contralateral primary motor leg area (M1) 0–5 ms after eliciting the H‐reflex. The same paradigm was applied to 8 healthy individuals (5 men, 3 women; 50.8 ± 3.0 years). Transcranial magnetic stimulation (TMS) facilitated the H‐reflex amplitude in healthy controls. A facilitatory effect of the corticospinal input on the H‐reflex was also found in patients with PD, but only with STN‐HFS switched on. When STN‐HFS was discontinued, the H‐reflex was no longer facilitated by the TMS pulse. Accordingly, analysis of variance showed a main effect of stimulation (F = 11.15; P = 0.005), ISI (F = 6.1; P = 0.003), and an interaction between stimulation and group (PD vs. control) (F = 8.9; P = 0.01). STN‐HFS restores the normal facilitatory drive of a transcranially evoked motor cortical response to the spinal motoneuron pool. In addition to subcortical routes, STN‐DBS also alters spinal excitability via transcortical pathways. © 2008 Movement Disorder Society.
Early symptoms in spinocerebellar ataxia type 1, 2, 3, and 6
Authors: Globas Christoph , du Montcel Sophie Tezenas , Baliko Laslo , Boesch Syliva , Depondt Chantal , DiDonato Stefano , Durr Alexandra , Filla Alessandro , Klockgether Thomas , Mariotti Caterina , Melegh Bela , Rakowicz Maryla , Ribai Pascale , Rola Rafal , Schmitz‐Hubsch Tanja , Szymanski Sandra , Timmann Dagmar , Van de Warrenburg Bart P. , Bauer Peter , Schols Ludger 
Published: August 2008

AbstractOnset of genetically determined neurodegenerative diseases is difficult to specify because of their insidious and slowly progressive nature. This is especially true for spinocerebellar ataxia (SCA) because of varying affection of many parts of the nervous system and huge variability of symptoms. We investigated early symptoms in 287 patients with SCA1, SCA2, SCA3, or SCA6 and calculated the influence of CAG repeat length on age of onset depending on (1) the definition of disease onset, (2) people defining onset, and (3) duration of symptoms. Gait difficulty was the initial symptom in two‐thirds of patients. Double vision, dysarthria, impaired hand writing, and episodic vertigo preceded ataxia in 4% of patients, respectively. Frequency of other early symptoms did not differ from controls and was regarded unspecific. Data about disease onset varied between patients and relatives for 1 year or more in 44% of cases. Influence of repeat length on age of onset was maximum when onset was defined as beginning of permanent gait disturbance and cases with symptoms for more than 10 years were excluded. Under these conditions, CAG repeat length determined 64% of onset variability in SCA1, 67% in SCA2, 46% in SCA3, and 41% in SCA6 demonstrating substantial influence of nonrepeat factors on disease onset in all SCA subtypes. Identification of these factors is of interest as potential targets for disease modifying compounds. In this respect, recognition of early symptoms that develop before onset of ataxia is mandatory to determine the shift from presymptomatic to affected status in SCA. © 2008 Movement Disorder Society
Neurological effects of recombinant human erythropoietin in Friedreich's ataxia: A clinical pilot trial
Authors: Boesch Sylvia , Sturm Brigitte , Hering Sascha , Scheiber‐Mojdehkar Barbara , Steinkellner Hannes , Goldenberg Hans , Poewe Werner 
Published: August 2008

AbstractIn a “proof‐of‐concept” study, we demonstrated that recombinant human erythropoietin (rhuEPO) increases frataxin levels in Friedreich's ataxia (FRDA) patients. We now report a 6‐month open‐label clinical pilot study of safety and efficacy of rhuEPO treatment in FRDA. Eight adult FRDA patients received 2.000 IU rhuEPO thrice a week subcutaneously. Clinical outcome measures included Ataxia Rating Scales. Frataxin levels and indicators for oxidative stress were assessed. Hematological parameters were monitored biweekly. Scores in Ataxia Rating Scales such as FARS (P = 0.0063) and SARA (P = 0.0045) improved significantly. Frataxin levels increased (P = 0.017) while indicators of oxidative stress such as urine 8‐OHdG (P = 0.012) and peroxide levels decreased (P = 0.028). Increases in hematocrit requiring phlebotomies occurred in 4 of 8 patients. In this explorative open‐label clinical pilot study, we found an evidence for clinical improvement together with a persistent increase of frataxin levels and a reduction of oxidative stress parameters in patients with FRDA receiving chronic treatment with rhuEPO. Safety monitoring with regular blood cell counts and parameters of iron metabolism is a potential limitation of this approach. © 2008 Movement Disorder Society
Structure elucidation of two new xanthone derivatives from the marine fungus Penicillium sp. (ZZF 32#) from the South China Sea
Authors: Shao Changlun , Wang Changyun , Wei Meiyan , Gu Yucheng , Xia Xuekui , She Zhigang , Lin Yongcheng 
Published: August 2008

AbstractTwo new xanthones, 8‐(methoxycarbonyl)‐1‐hydroxy‐9‐oxo‐9H‐xanthene‐3‐carboxylic acid (1) and dimethyl 8‐methoxy‐9‐oxo‐9H‐xanthene‐1, 6‐dicarboxylate (2) and one known xanthone methyl 8‐hydroxy‐6‐methyl‐9‐oxo‐9H‐xanthene‐1‐carboxylate (3) were isolated from the culture broth of the mangrove fungus Penicillium sp. (ZZF 32#) collected from the South China Sea. Their structures were established by comprehensive analysis of one‐dimensional (1D) and two‐dimensional (2D) NMR data. The structure of compound 3 was confirmed by X‐ray crystallography, which led to the suggestion that janthinone (4) might have the same structure as 3. Compounds 1–3 were inactive against KB or KBv200 cells during cytotoxicity evaluations. Copyright © 2008 John Wiley & Sons, Ltd.
Assessing optic nerve pathology with diffusion MRI: from mouse to human
Authors: Xu Junqian , Sun Shu‐Wei , Naismith Robert T. , Snyder Abraham Z. , Cross Anne H. , Song Sheng‐Kwei 
Published: August 2008

AbstractThe optic nerve is often affected in patients with glaucoma and multiple sclerosis. Conventional MRI can detect nerve damage, but it does not accurately assess the underlying pathologies. Mean diffusivity and diffusion anisotropy indices derived from diffusion tensor imaging have been shown to be sensitive to a variety of central nervous system white matter pathologies. Despite being sensitive, the lack of specificity limits the ability of these measures to differentiate the underlying pathology. Directional (axial and radial) diffusivities, measuring water diffusion parallel and perpendicular to the axonal tracts, have been shown to be specific to axonal and myelin damage in mouse models of optic nerve injury, including retinal ischemia and experimental autoimmune encephalomyelitis. The progression of Wallerian degeneration has also been detected using directional diffusivities after retinal ischemia. However, translating these findings to human optic nerve is technically challenging. The current status of diffusion MRI of human optic nerve, including imaging sequences and protocols, is summarized herein. Despite the lack of a consensus among different groups on the optimal sequence or protocol, increased mean diffusivity and decreased diffusion anisotropy have been observed in injured optic nerve from patients with chronic optic neuritis. From different mouse models of optic nerve injuries to the emerging studies on patients with optic neuritis, directional diffusivities show great potential to be specific biomarkers for axonal and myelin injury. Copyright © 2008 John Wiley & Sons, Ltd.
TK‐AKA: using temporary key on Authentication and Key Agreement protocol on UMTS
Authors: Ou Hsia‐Hung , Lin Iuon‐Chang , Hwang Min‐Shiang , Jan Jinn‐Ke 
Published: August 2008

AbstractMobile communication is definitely one of the major high‐technology applications that offer present‐day people a modern life of appropriate convenience. In recent years, the third‐generation cell phone system has approached maturity. The Universal Mobile Telecommunication System (UMTS) is currently the most widely used system around the world. The Third Generation Partnership Project is equipped with the Authentication and Key Agreement (AKA) protocol to maintain secrecy and security both during the authentication process and during the telecommunication session through UMTS. However, Hung and Li have pointed out that the UMTS‐AKA protocol has three problems, involving bandwidth consumption, space overhead and synchronization of the sequence number, which are yet to be resolved. In addition, they have proposed an extension of the UMTS‐AKA protocol, named the X‐AKA protocol, to overcome these obstacles. Nevertheless, the X‐AKA protocol too appears to have problems of its own. In this article, the weaknesses of X‐AKA are enumerated. In addition, a more practical AKA protocol for UMTS is presented. The new protocol, based on the same framework as its predecessor, proves to be more efficient and practical, satisfying the requirements of modern living. Copyright © 2008 John Wiley & Sons, Ltd.
A dissipation‐based arc‐length method for robust simulation of brittle and ductile failure
Authors: Verhoosel Clemens V. , Remmers Joris J. C. , Gutiérrez Miguel A. 
Published: August 2008

AbstractA robust method to trace the equilibrium path in non‐linear solid mechanics problems is proposed. A general arc‐length constraint based on the energy release rate is developed. Constraints have been derived for the cases of geometrically linear damage, geometrically linear plasticity and geometrically non‐linear damage. All three constraints can efficiently be applied in a finite element context. Numerical simulations demonstrate that the proposed framework gives robust results for these cases. Applicability of the proposed framework to other types of constitutive and/or kinematic behaviour is predicted. Copyright © 2008 John Wiley & Sons, Ltd.
An efficient and conservative hybrid method for solving multidimensional conservation laws
Authors: Manzini Gianmarco 
Published: August 2008

AbstractWe have developed an efficient hybrid technique for solving nonlinear conservation laws. Previous hybrid techniques have been accurate but lacked the property of conservation, whereas our technique is both accurate and conservative. To achieve this, we superimposed all possible stencils for ENO polynomials and weighted the value from each cells in a way that depends on the numerical solution. Computational efficiency relies on switching from central data where the exact solution is smooth to noncentral data near discontinuities. We prove the theoretical consistency of the technique and discuss the connection with ENO and WENO methods. We introduce time dependency by combining our method with Runge‐Kutta schemes that are TVD preserving. We have verified our technique experimentally by solving a suite of test problems with convex and non‐convex flux functions taken from the literature. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2009
Functional a posteriori error estimates for discontinuous Galerkin approximations of elliptic problems
Authors: Lazarov Raytcho , Repin Sergey , Tomar Satyendra K. 
Published: August 2008

AbstractIn this article, we develop functional a posteriori error estimates for discontinuous Galerkin (DG) approximations of elliptic boundary‐value problems. These estimates are based on a certain projection of DG approximations to the respective energy space and functional a posteriori estimates for conforming approximations developed by S. Repin (see e.g., Math Comp 69 (2000) 481–500). On these grounds, we derive two‐sided guaranteed and computable bounds for the errors in “broken” energy norms. A series of numerical examples presented confirm the efficiency of the estimates. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
An upwind finite volume element method based on quadrilateral meshes for nonlinear convection‐diffusion problems
Authors: Gao Fu‐Zheng , Yuan Yi‐Rang 
Published: August 2008

AbstractConsidering an upwind finite volume element method based on convex quadrilateral meshes for computing nonlinear convection‐diffusion problems, some techniques, such as calculus of variations, commutating operator, and the theory of prior error estimates and techniques, are adopted. Discrete maximum principle and optimal‐order error estimates in H1 norm for fully discrete method are derived to determine the errors in the approximate solution. Thus, the well‐known problem [(Li et al., Generalized difference methods for differential equations: numerical analysis of finite volume methods, Marcel Dekker, New York, 2000), p 365.] has been solved. Some numerical experiments show that the method is a very effective engineering computing method for avoiding numerical dispersion and nonphysical oscillations. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2009
Mode I and Mode II delamination resistance and mechanical properties of woven glass/epoxy–PU IPN composites
Authors: Sampath P.S. , Murugesan V. , Sarojadevi M. , Thanigaiyarasu G. 
Published: August 2008

AbstractThe effect of polyurethane on the mechanical properties and Mode I and Mode II interlaminar fracture toughness of glass/epoxy composites were studied. Polyurethanes (PU) synthesized using polyols and toluene diisocyanate were employed as modifier for epoxy resin by forming interpenetrating polymer network. The PU/Epoxy IPN was used as matrix material for GFRP. PU modified epoxy composite laminates having varying PU contents were prepared. The effect of PU content on the mechanical properties like interlaminar fracture toughness (Mode I, G1c and Mode II, GIIc), tensile strength, flexural strength, and Izod impact strength were studied. The morphological studies were conducted on the fractured surface of the composite specimen by scanning electron microscopy (SEM). Tensile strength, flexural strength, and impact strength of PU‐modified epoxy composite laminates were found to increase inline with interlaminar fracture toughness (G1c and GIIc) with increasing PU content to a certain limit and then it was found to decrease with increase in PU content. It was observed that toughening of epoxy with PU increases the Mode I and Mode II delamination toughness up to 17 and 120% higher than that of untoughened composite specimen, respectively. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Nonisothermal crystallization behavior and crystals morphology of poly(trimethylene terephthalate)/nano‐calcium carbonate composites
Authors: Run Mingtao , Yao Chenguang , Wang Yingjin , Song Hongzan 
Published: August 2008

AbstractNonisothermal crystallization behavior and crystal morphology of poly(trimethylene terephthalate) (PTT) composites filled with modified nano‐calcium carbonate (CaCO3) had been investigated by using differential scanning calorimetry and polarized optical microscopy. The modified Avrami equation and Ozawa theory were used to investigate the nonisothermal crystallization, respectively. The particles of nano‐CaCO3, acting as a nucleation agent in composites, accelerated the crystallization rate by decreasing the half‐time of crystallization or increasing the parameters of Zc and K(T). Moreover, the nano‐composite with 2 wt% nano‐CaCO3 exhibited the highest crystallization rate. The Avrami and the Ozawa exponents, n and m of the nano‐composites, were higher than those of neat PTT, suggesting more complicated interaction between molecular chains and the nanoparticles that cause the changes of the nucleation mode and the crystal growth dimension. The effective activation energy calculated from the Friedman formula was reduced as nano‐CaCO3 content increased, suggesting that the nano‐CaCO3 made the molecular chains of PTT easier to crystallize during the nonisothermal crystallization process. The optical micrographs showed that much smaller or less perfect crystals were formed in composites because of the presence of the nano‐CaCO3 particles. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Development of novel conducting composites of nanostructured poly(1‐naphthylamine) with poly(vinyl chloride)
Authors: Riaz Ufana , Ahmad Sharif , Ashraf S.M. 
Published: August 2008

AbstractInvestigations on the synthesis of nanoconducting polymers have gained much popularity during the past few decades. The processibility of the nanostructured conducting polymers is poor, which hinders their commercial application. Considering the drawbacks of nanostructured conducting polymers, this article reports for the first time the synthesis of processible composites of nanostructured poly(1‐naphthylamine) (PNA), a polyaniline derivative with poly(vinyl chloride) (PVC). The composites were prepared by loading different weight ratios of PNA (2–10 wt%) in PVC. The composites were characterized by spectral, thermal, morphological, and conductivity studies. The particle size of PNA/PVC composites was confirmed by transmission electron microscopy and was found to be in the range of 5–20 nm. The highest conductivity of 2.5 × 10−2 S/cm was obtained in the composite with 4 wt% loading of PNA. The high conductivity of the composites was correlated to the agglomerate‐free uniform dispersion of self‐assembled nanofibrillar network of PNA particles in the PVC matrix. The PNA/PVC composites exhibited good mechanical properties, which holds potential for use in semiconductor nanodevices. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Die Entdeckung der Langsamkeit. Dünenbildung auf dem Mars
Authors: Ribeiro Parteli Eric Josef , Herrmann Hans‐Jürgen 
Published: August 2008

AbstractMarsdünen zeigen große Formenvielfalt. Sie reichen von charakteristischen Wanderdünen, den von der Erde bekannten Barchanen, bis zu exotischen Dünenformen. Die Marsmissionen warfen die Frage auf, ob diese Dünen in der heutigen Marsatmosphäre überhaupt noch entstehen oder wandern können. Computersimulationen zeigen nun, dass das möglich ist. Allerdings treten die zum Sandtransport erforderlichen Windgeschwindigkeiten sehr selten auf. Deshalb brauchen die Dünen für solche Prozesse je nach Form vermutlich Zehntausende bis mehrere Millionen Jahre. Auch die Entstehung exotischer Dünenformen konnte erfolgreich simuliert werden. Die Ursache ist Wind, der zwischen zwei festen Richtungen oszilliert.
Verschränkung von Spins in Diamant
Authors: Rempp Florian , Neumann Philipp , Wrachtrup Jörg 
Published: August 2008

AbstractIn den letzten Jahren ist es gelungen, freie Teilchen, wie Photonen oder Atome, miteinander zu verschränken. Unsere Gruppe an der Universität Stuttgart konnte jüngst einzelne Kernspins in Diamant verschränken. Da das Experiment bei Raumtemperatur funktioniert, könnte diese Technik für die zukünftige Entwicklung eines Quantencomputers von Bedeutung sein.
Licht auf die Spitze getrieben
Authors: Pettinger Bruno 
Published: August 2008

AbstractKlassische optische Mikroskope unterscheiden Stoffe an Hand ihrer Farbspektren, können aber bisher einzelne Atome oder Moleküle nicht abbilden. Unsere Gruppe am Fritz‐Haber‐Institut der Max‐Planck‐Gesellschaft in Berlin hat nun ein optisches Mikroskop entwickelt, das einzelne Moleküle mit Hilfe ihres abgestrahlten Raman‐Lichtes abbildet. Seine Auflösung von 15 Nanometer ist mit der von Rasterkraftmikroskopen vergleichbar und liegt damit weit unter der Beugungsgrenze optischer Mikroskope.
Vom Experiment im Gartenlabor zum Nanoinstrument
Authors: Junk Andreas 
Published: August 2008

AbstractLange Zeit galt Röntgenstrahlung als nicht fokussierbar. Deswegen waren abbildende Instrumente wie Mikroskope oder Teleskope für diesen Bereich elektromagnetischer Strahlung nicht realisierbar. 1967 gelang mit dem holografischen Ansatz von Astronomen der Universitätssternwarte Göttingen der Durchbruch bei der Fertigung von Optiken für weiche Röntgenstrahlung. In den Folgejahren bauten sie das transmittierende Zonenplatten‐Röntgenmikroskop (TXM), das heute ein wertvolles Instrument in der Nanotechnologie ist.