julilili42/papers huggingface dataset:
Continuous brachial plexus blockade in combination with the NMDA receptor antagonist memantine prevents phantom pain in acute traumatic upper limb amputees
2006-05-23

Abstract Background: Hyperexcitability of N ‐methyl‐ d ‐aspartate acid (NMDA) receptors may play an important role in the development of phantom limb pain (PLP). Aim of the study: To investigate whether early treatment with the NMDA antagonist memantine attenuates phantom pain memory formation in traumatic amputees. Methods: In a randomized, double‐blind, controlled trial 19 patients with acute traumatic amputation of the upper extremity were investigated. All patients received postoperative analgesia by continuous brachial plexus anesthesia (ropivacaine 0.375% 5ml/h) for at least 7 days. In addition, the patients received either memantine (20–30mg daily, n =10) or placebo ( n =9) for 4 weeks. Results: Memantine treatment reduced the number of requested ropivacacine bolus injections during the first week and resulted in a significant decrease of PLP prevalence and intensity at 4 weeks and 6 months follow up, but not at 12 months follow up. Conclusions: We conclude that memantine can reduce intensity of phantom limb pain and might also prevent the development of PLP. However, despite the very early begin of treatment; no long‐term effect on established PLP was evident.
Synthesis and Properties of Some New 1,4‐Dihydrothieno[3,2‐e][1,2,4]triazepin‐5‐ones.
2006-05-23

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stem cell transplantation for polycythemia vera
2006-05-24

Abstract Polycythemia vera (PV) is a rare disease in children. A 9‐year‐old male was diagnosed following laboratory results acquired because of an acute appendicitis. Regular phlebotomy was performed for over 2 years followed by α‐interferon treatment. At the age of 12 years, HLA‐matched unrelated stem cell transplantation including T‐cell depletion was done. The conditioning regimen consisted of busulfan, cyclophosphamide, and ATG. Chimerism was monitored during the whole post‐transplant period. A single dose of donor T ‐lymphocytes was given at month 3. One year after transplantation, chimerism was complete. The patient is in complete remission and shows no signs of transplant‐related morbidity at month 78. Pediatr Blood Cancer 2008;50:124–126. © 2006 Wiley‐Liss, Inc.
Antiproliferative and cytotoxic properties of bevacizumab on different ocular cells
2006-05-25

These experimental findings support the safety of intravitreal bevacizumab when used at the currently applied concentration of about 0.25 mg/ml. Bevacizumab exerts a moderate growth inhibition on CEC when used in concentrations of at least 0.025 mg/ml. However, at higher doses (2.5 mg/ml) bevacizumab may be harmful to the retinal pigment epithelium.
Impact of the hepatitis B virus genotype and genotype mixtures on the course of liver disease in Vietnam†
2006-05-25

Eight genotypes (A-H) of hepatitis B virus (HBV) have been identified. However, the impact of different genotypes on the clinical course of hepatitis B infection remains controversial. We investigated the frequency and clinical outcome of HBV genotypes and genotype mixtures in HBV-infected patients from Vietnam, Europe, and Africa. In addition, we analyzed the effects of genotype mixtures on alterations in in vitro viral replication. In Asian patients, seven genotypes (A-G) were detected, with A, C, and D predominating. In European and African patients, only genotypes A, C, D, and G were identified. Genotype mixtures were more frequently encountered in African than in Asian (P = .01) and European patients (P = .06). In Asian patients, the predominant genotype mixtures included A/C and C/D, compared to C/D in European and A/D in African patients. Genotype A was more frequent in asymptomatic compared with symptomatic patients (P < .0001). Genotype C was more frequent in patients with hepatocellular carcinoma (HCC; P = .02). Genotype mixtures were more frequently encountered in patients with chronic hepatitis in comparison to patients with acute hepatitis B (P = .015), liver cirrhosis (P = .013), and HCC (P = .002). Viral loads in patients infected with genotype mixtures were significantly higher in comparison to patients with a single genotype (P = .019). Genotype mixtures were also associated with increased in vitro HBV replication. In conclusion, infection with mixtures of HBV genotypes is frequent in Asia, Africa, and Europe. Differences in the replication-phenotype of single genotypes compared to genotype-mixtures suggest that co-infection with different HBV-genotypes is associated with altered pathogenesis and clinical outcome.
Anaerobic Cometabolic Transformation of Polycyclic and Heterocyclic Aromatic Hydrocarbons: Evidence from Laboratory and Field Studies
2006-05-25

The sulfate-reducing enrichment culture N47 can grow on naphthalene or 2-methylnaphthalene as the sole carbon and energy source. Here we show that the culture can furthermore cometabolicallytransform a variety of polycyclic and heteroaromatic compounds with naphthalene or methylnaphthalene as the auxiliary substrate. Most of the cosubstrates were converted to the corresponding carboxylic acids, frequently to several isomers. The mass spectra of specific metabolites that were extracted from supernatants of cultures containing the cosubstrates benzothiophene, benzofuran, and 1-methylnaphthalene resembled known intermediates of the anaerobic naphthalene and 2-methylnaphthalene degradation pathways (i.e., naphthyl-2-methylsuccinic acid and naphthyl-2-methylenesuccinic acid). This indicates that some of the tested compounds were first methylated and then transformed to the corresponding methylsuccinic acids by a fumarate addition to the methyl group. For some of the cosubstrates, a partial or total inhibition of growth on the auxiliary substrate was observed. This was not caused by the toxicity of the individual cosubstrate itself, but by a specific combination of auxiliary substrate and cosubstrate. None of the cosubstrates tested could be utilized as the sole carbon source and electron donor by the enrichment culture N47. Field investigations at the tar-oil-contaminated aquifer, where strain N47 originated, revealed the presence of a number of metabolites similar to the ones identified in batch culture supernatants. Our findings suggest that aromatic hydrocarbons and heterocyclic compounds can be converted by aquifer organisms and produce a variety of polar compounds that become mobile in groundwater.
Explanatory and illustrative visualization of special and general relativity
2006-05-25

This paper describes methods for explanatory and illustrative visualizations used to communicate aspects of Einstein's theories of special and general relativity, their geometric structure, and of the related fields of cosmology and astrophysics. Our illustrations target a general audience of laypersons interested in relativity. We discuss visualization strategies, motivated by physics education and the didactics of mathematics, and describe what kind of visualization methods have proven to be useful for different types of media, such as still images in popular science magazines, film contributions to TV shows, oral presentations, or interactive museum installations. Our primary approach is to adopt an egocentric point of view: The recipients of a visualization participate in a visually enriched thought experiment that allows them to experience or explore a relativistic scenario. In addition, we often combine egocentric visualizations with more abstract illustrations based on an outside view in order to provide several presentations of the same phenomenon. Although our visualization tools often build upon existing methods and implementations, the underlying techniques have been improved by several novel technical contributions like image-based special relativistic rendering on GPUs, special relativistic 4D ray tracing for accelerating scene objects, an extension of general relativistic ray tracing to manifolds described by multiple charts, GPU-based interactive visualization of gravitational light deflection, as well as planetary terrain rendering. The usefulness and effectiveness of our visualizations are demonstrated by reporting on experiences with, and feedback from, recipients of visualizations and collaborators.
On-line novelty detection by recursive dynamic principal component analysis and gas sensor arrays under drift conditions
2006-05-25

Leakage detection is a common chemical-sensing application. Leakage detection by thresholds on a single sensor signal suffers from important drawbacks when sensors show drift effects or when they are affected by other long-term cross sensitivities. In this paper, we present an adaptive method based on a recursive dynamic principal component analysis (RDPCA) algorithm that models the relationships between the sensors in the array and their past history. In normal conditions, a certain variance distribution characterizes sensor signals, however, in the presence of a new source of variance the PCA decomposition changes drastically. In order to prevent the influence of sensor drift, the model is adaptive, and it is calculated in a recursive manner with minimum computational effort. The behavior of this technique is studied with synthetic and real signals arising by oil vapor leakages in an air compressor. Results clearly demonstrate the efficiency of the proposed method
Decreased cation channel activity and blunted channel-dependent eryptosis in neonatal erythrocytes
2006-05-25

Eryptosis or apoptosis-like death of erythrocytes is characterized by phosphatidylserine exposure and erythrocyte shrinkage, both typical features of nucleated apoptotic cells. Eryptosis is triggered by activation of nonselective Ca 2+ -permeable cation channels with subsequent entry of Ca 2+ and stimulation of Ca 2+ -sensitive scrambling of the cell membrane. The channels are activated and thus eryptosis is triggered by Cl − removal, osmotic shock, oxidative stress, or glucose deprivation. The present study has been performed to compare cation channel activity and susceptibility to eryptosis in neonatal and adult erythrocytes. Channel activity was determined by patch-clamp analysis, cytosolic Ca 2+ activity by fluo-3 fluorescence, phosphatidylserine exposure by FITC-labeled annexin V binding, and cell shrinkage by decrease in forward scatter in fluorescence-activated cell sorting analysis. Prostaglandin E 2 (PGE 2 ) formation, cation channel activity, Ca 2+ entry, annexin V binding, and decreased forward scatter were triggered by removal of Cl − in both adult and neonatal erythrocytes. The effects were, however, significantly blunted in neonatal erythrocytes. Osmotic shock, PGE 2, and platelet-activating factor similarly increased annexin V binding and decreased forward scatter, effects again significantly reduced in neonatal erythrocytes. On the other hand, spontaneous and oxidative (addition of tert-butylperoxide) stress-induced eryptosis was significantly larger in neonatal erythrocytes. In conclusion, cation channel activity, Ca 2+ leakage, and thus channel-dependent triggering of eryptosis are blunted, whereas spontaneous and oxidative stress-induced eryptosis is more pronounced in neonatal erythrocytes.
Progressive multifocal leukoencephalopathy: value of diffusion‐weighted and contrast‐enhanced magnetic resonance imaging for diagnosis and treatment control
2006-05-26

Progressive multifocal leukoencephalopathy (PML) is caused by the replication of JC virus in oligodendrocytes of immunocompromised patients. Diagnosis usually relies on the polymerase chain reaction (PCR)‐based demonstration of JC virus DNA in the cerebrospinal fluid. As previous reports have suggested that some patients may benefit from antiviral therapy, non‐invasive early diagnosis is highly desirable. Repetitive magnetic resonance imaging (MRI) examinations (two to nine) were obtained in seven patients (aged 40–67 years, six males, one female) with classical clinical and imaging findings of PML. Five patients had underlying hematological disorders and two acquired immune deficiency syndrome. PCR of the cerebrospinal fluid (CSF) specimen was positive for JC virus DNA in six patients. MRI sequences included T2‐, T1‐ and diffusion‐weighted (DW) images in all patients and diffusion‐tensor imaging (DTI) in four cases. DTI was once performed at 3T, in the remaining patients at 1.5T. All patients received antiviral treatment with cidofovir in addition to the treatment of the underlying disorder. MRI showed areas of T2 hyperintensity with involvement of the subcortical U‐fibers and restricted diffusion in all patients. Areas of diffusion abnormality correlated with disease progress. Contrast enhancement was encountered once after successful treatment and heralded clinical remission with virus elimination from the CSF. Hence, MRI including DW and contrast‐enhanced images may be used to evaluate disease activity. Contrast enhancement may indicate an inflammatory response and thus herald immunologic virus elimination.
Ammonium ion transport by the AMT/Rh homologue LeAMT1;1
2006-05-29

AMT (ammonium transporter)/Rh (Rhesus) ammonium transporters/channels are identified in all domains of life and fulfil contrasting functions related either to ammonium acquisition or excretion. Based on functional and crystallographic high-resolution structural data, it was recently proposed that the bacterial AmtB (ammonium transporter B) is a gas channel for NH3 [Khademi, O'Connell, III, Remis, Robles-Colmenares, Miercke and Stroud (2004) Science 305, 1587–1594; Zheng, Kostrewa, Berneche, Winkler and Li (2004) Proc. Natl. Acad. Sci. U.S.A. 101, 17090–17095]. Key residues, proposed to be crucial for NH3 conduction, and the hydrophobic, but obstructed, pore were conserved in a homology model of LeAMT1;1 from tomato. Transport by LeAMT1;1 was affected by mutations of residues that were predicted to constitute the aromatic recruitment site for NH4+ at the external pore entrance. Despite the structural similarities, LeAMT1;1 was shown to transport only the ion; each transported 14C-methylammonium molecule carried a single positive elementary charge. Similarly, NH4+ (or H+/NH3) was transported, but NH3 conduction was excluded. It is concluded that related proteins and a similar molecular architecture can apparently support contrasting transport mechanisms.
Bees of Santa Catarina Island, Brazila first survey and checklist (Insecta: Apoidea)
2006-05-30

On Santa Catarina Island bees were collected between 1999 and 2006 using various methods, including netting, trap nesting, and baiting. Vegetation types sampled comprised secondary forests, dunes, pastures, and parks. A checklist of 166 species of bees is presented. The family Apidae was represented by the highest number of species, followed by Megachilidae and Halictidae. Only a few species of Colletidae and Andrenidae were recorded. Species richness and occurrence of genera are compared to the results of other collections performed in the neighboring states of Paraná and Rio Grande do Sul.
Fostering collaborative knowledge construction in a video‐based learning setting: effects of a shared workspace and a content‐specific graphical representation
2006-05-30

Abstract This study examined means of fostering videoconference‐based collaborative learning. An experiment was conducted with 15 learning dyads divided into three conditions of videoconference‐based learning: without shared workspace, with shared workspace and with shared workspace plus a content‐specific graphical representation. Compared with those with a shared workspace, learning dyads without a shared workspace in the videoconference‐based setting tended to make more effort at verbal coordination. This coordination effort did not affect the quality of collaboratively written texts or individual knowledge acquisition. Without shared workspace, participants’ coordinative utterances involved more frequent referrals to the learning content, which might have facilitated the cognitive processing of the learning content and might have compensated for the potential disadvantage of verbal coordination load. The content‐specific graphical representation led to more coherent content‐related dialogues and had positive effects on the quality of the collaboratively written texts and on individual knowledge acquisition. The study shows that content‐specific graphical representation can be a meaningful support measure in videoconference‐based learning settings, whereas the effects of a shared workspace should be further investigated.
Porphyrins, Phthalocyanines and Related Compounds as Materials for Optical Limiting
2006-05-30

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Calcium Tetraboride—Does It Exist? Synthesis and Properties of a Carbon‐Doped Calcium Tetraboride that Is Isotypic with the Known Rare Earth Tetraborides.
2006-05-30

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Radiotherapy and Temozolomide for Newly Diagnosed Glioblastoma: Recursive Partitioning Analysis of the EORTC 26981/22981-NCIC CE3 Phase III Randomized Trial
2006-05-31

Purpose The European Organisation for Research and Treatment of Cancer and National Cancer Institute of Canada trial on temozolomide (TMZ) and radiotherapy (RT) in glioblastoma (GBM) has demonstrated that the combination of TMZ and RT conferred a significant and meaningful survival advantage compared with RT alone. We evaluated in this trial whether the recursive partitioning analysis (RPA) retains its overall prognostic value and what the benefit of the combined modality is in each RPA class. Patients and Methods Five hundred seventy-three patients with newly diagnosed GBM were randomly assigned to standard postoperative RT or to the same RT with concomitant TMZ followed by adjuvant TMZ. The primary end point was overall survival. The European Organisation for Research and Treatment of Cancer RPA used accounts for age, WHO performance status, extent of surgery, and the Mini-Mental Status Examination. Results Overall survival was statistically different among RPA classes III, IV, and V, with median survival times of 17, 15, and 10 months, respectively, and 2-year survival rates of 32%, 19%, and 11%, respectively (P &lt; .0001). Survival with combined TMZ/RT was higher in RPA class III, with 21 months median survival time and a 43% 2-year survival rate, versus 15 months and 20% for RT alone (P = .006). In RPA class IV, the survival advantage remained significant, with median survival times of 16 v 13 months, respectively, and 2-year survival rates of 28% v 11%, respectively (P = .0001). In RPA class V, however, the survival advantage of RT/TMZ was of borderline significance (P = .054). Conclusion RPA retains its prognostic significance overall as well as in patients receiving RT with or without TMZ for newly diagnosed GBM, particularly in classes III and IV.
The Role of Multiple Contralesional Motor Areas for Complex Hand Movements after Internal Capsular Lesion
2006-05-31

Imaging techniques document enhanced activity in multiple motor areas of the damaged and contralesional (intact) hemisphere (CON-H) after stroke. In the subacute stage, increased activity within motor areas in the CON-H during simple movements of the affected hand has been shown to correlate with poorer motor outcome. For those patients in the chronic stage who recovered well, the functional relevance of an increased activation within the CON-H is unclear. Using trains of repetitive transcranial magnetic stimulation (TMS) during performance of complex finger movements, we tested the behavioral relevance of regional functional magnetic resonance imaging (fMRI) activation within the CON-H for sequential finger movement performance of the recovered hand in seven patients who had experienced a subcortical stroke. TMS was navigated over fMRI activation maxima within anatomically preselected regions of the CON-H, and effects were compared with those of healthy controls. Stimulation over the dorsal premotor cortex (dPMC), the primary motor cortex (M1), and the superior parietal lobe (SPL) resulted in significant interference with recovered performance in patients. Interference with the dPMC and M1 induced timing errors only, SPL stimulation caused both timing and accuracy deficits. The present results argue for a persistent beneficial role of the dPMC, M1, and SPL of the CON-H on some aspects of effectively recovered complex motor behavior after subcortical stroke.
Lesion-induced right-hemispheric language and organization of nonverbal functions
2006-05-31

Early left-hemispheric brain lesions may lead to a reorganization of language into the right hemisphere. Language functions are consecutively spared, but visuospatial functions show slight deficits. Cortical 'crowding' of the right hemisphere has been suggested as an explanation for this effect, but no direct evidence has as yet been put forward. We examined six patients with early left-hemispheric brain lesions and subsequent right-hemispheric language organization with functional magnetic resonance imaging and compared their activation patterns in a verbal and two nonverbal tasks with the patterns of six controls. In the patient group, nonverbal functions were reorganized neither interhemispherically nor intrahemispherically. Instead, verbal and nonverbal functions were mediated by a common right-hemispheric network. This argues in favour of the 'crowding hypothesis'.
On the maximal cliques in c-max-tolerance graphs and their application in clustering molecular sequences
2006-05-31

Abstract Given a set S of n locally aligned sequences, it is a needed prerequisite to partition it into groups of very similar sequences to facilitate subsequent computations, such as the generation of a phylogenetic tree. This article introduces a new method of clustering which partitions S into subsets such that the overlap of each pair of sequences within a subset is at least a given percentage c of the lengths of the two sequences. We show that this problem can be reduced to finding all maximal cliques in a special kind of max-tolerance graph which we call a c-max-tolerance graph. Previously we have shown that finding all maximal cliques in general max-tolerance graphs can be done efficiently in O ( n 3 + out ). Here, using a new kind of sweep-line algorithm, we show that the restriction to c -max-tolerance graphs yields a better runtime of O ( n 2 log n + out ). Furthermore, we present another algorithm which is much easier to implement, and though theoretically slower than the first one, is still running in polynomial time. We then experimentally analyze the number and structure of all maximal cliques in a c -max-tolerance graph, depending on the chosen c -value. We apply our simple algorithm to artificial and biological data and we show that this implementation is much faster than the well-known application Cliquer. By introducing a new heuristic that uses the set of all maximal cliques to partition S , we finally show that the computed partition gives a reasonable clustering for biological data sets.