julilili42/papers huggingface dataset:
Crystal Structure of Ce3Ni2(BN)2N and Magnetic Behavior of (CeNi(BN))2(CeN)x with x = 0, 1
2008-05-05

Abstract The new compound Ce 3 Ni 2 (BN) 2 N was synthesized by a modified solid state metathesis reaction. The crystal structure of Ce 3 Ni 2 (BN) 2 N was found to be isotypic with the superconducting compound La 3 Ni 2 (BN) 2 N, according to Rietveld refinements performed on X‐ray powder data ( I4/mmm , Z = 2, a = 3.5817(1) Å, c = 20.283(1) Å). Corresponding solid state reactions of mixtures composed of CeN/NiB and CeNi/BN yielded CeNi(BN) and a mixture of the two closely related layered structures (CeNi(BN)) 2 (CeN) x with x = 0 and 1. Magnetization experiments on these samples revealed temperature independent paramagnetic behavior for Ce 3 Ni 2 (BN) 2 N and CeNi(BN) without any magnetic ordering down to 5 K.
Quantitative electron microscopy and spectroscopy of MgB2wires and tapes
2008-05-06

In MgB2 the correlation of microstructure with superconducting properties, in particular the critical current density, requires powerful analytical tools. Critical current densities and electrical resistivities of different MgB2 superconductors differ by orders of magnitudes and the current limiting mechanisms have not been fully understood. Granularity of MgB2 is one significant reason for reduced critical current densities and is introduced intrinsically by the anisotropy of Bc2 but also extrinsically by the microstructure of the material. Bc2 enhancement by doping is another important challenge for chemical analysis and, at present, doping levels are not well controlled on the sub-μm scale.
NMR Analysis of KChIP4a Reveals Structural Basis for Control of Surface Expression of Kv4 Channel Complexes
2008-05-06

Potassium channel-interacting proteins (KChIPs) are EF-hand calcium-binding proteins of the recoverin/neuronal calcium sensor 1 family that co-assemble with the pore-forming Kv4 alpha-subunits and thus control surface trafficking of the voltage-gated potassium channels mediating the neuronal I(A) and cardiac I(to) currents. Different from the other KChIPs, KChIP4a largely reduces surface expression of the Kv4 channel complexes. Using solution NMR we show that the unique N terminus of KChIP4a forms a 6-turn alpha-helix that is connected to the highly conserved core of the KChIP protein via a solvent-exposed linker. As identified by chemical shift changes, N-terminal alpha-helix and core domain of KChIP4a interact with each other through the same hydrophobic surface pocket that is involved in intermolecular interaction between the N-terminal helix of Kv4alpha and KChIP in Kv4-KChIP complexes. Electrophysiological recordings and biochemical interaction assays of complexes formed by wild-type and mutant Kv4alpha and KChIP4a proteins suggest that competition of these two helical domains for the surface groove is responsible for the reduced trafficking of Kv4-KChIP4a complexes to the plasma membrane. Surface expression of Kv4 complexes may thus be controlled by an auto-inhibitory domain in the KChIP subunit.
Cerebral processing of emotional prosody: a network model based on fMRI studies
2008-05-06

Comprehension of information conveyed by emotional tone of speech is highly important for successful social interactions.Regarding the underlying neurobiological mechanisms, successive steps of cerebral processing involving auditory analysis within the temporal cortex and evaluative judgements within the frontal lobes have been differentiated (Schirmer & Kotz, 2006;Wildgruber et al., 2006).To further disentangle the impact of stimulus properties and appraisal levels a series of fMRI studies has been performed.The results of these studies indicate a strong association of cerebral responses and acoustic properties of the stimuli in some regions (stimulusdriven effects), whereas other areas showed modulation of activation linked to the focussing of attention to specific task components (task-dependent effects).Based on these findings a refined model of prosody processing and cross-modal integration of emotional signals from face and voice is postulated.
Dyschromatosis universalis hereditaria: evidence for autosomal recessive inheritance and identification of a new locus on chromosome 12q21‐q23
2008-05-07

Dyschromatosis universalis hereditaria (DUH) and dyschromatosis symmetrica hereditaria (DSH) are pigmentary dermatoses most commonly seen in Japan. Both disorders usually show autosomal dominant inheritance, although in some cases autosomal recessive inheritance was reported. DSH was mapped to chromosome 1q21.3, and mutations in the gene ADAR ( DSRAD ) were identified in Japanese, Chinese and Taiwanese families with autosomal dominant DSH. A second locus for dyschromatosis was mapped on chromosome 6q24.2‐q25.2 in two Chinese families initially reported to be affected with DSH, but later suggested to have autosomal dominant DUH. The aim of this study was to investigate whether one of these two loci is involved in the development of DUH in a consanguineous Bedouin family from Saudi Arabia with four affected and three unaffected sibs, clearly pointing to autosomal recessive inheritance. After excluding mutations in ADAR and linkage to the candidate regions on chromosomes 1 and 6, we performed an single nucleotide polymorphism‐based genome‐wide scan for linkage with other loci. Under the assumption of autosomal recessive inheritance, we have identified a new locus for dyschromatosis on chromosome 12q21‐q23 in this Arab family with a maximum logarithm of the odds (LOD) score of 3.4, spanning a distance of 18.9 cM. Our study revealed the first locus for autosomal recessive DUH and supports recent evidence that DSH and DUH are genetically distinct disorders.
Phase optimized liquid chromatography as an instrument for steroid analysis
2008-05-07

Abstract A new method using phase optimized LC (POPLC) for the analysis of steroids is described. The retention factors and the theoretical plate numbers of different steroids were determined for four different stationary phases. Based on these values, an optimal stationary phase composition and the resultant chromatogram have been calculated by an optimization software and compared to the measured data. It is demonstrated that these predicted data show only little differences to the experimental results. Furthermore, it is shown that the overall selectivity of the optimal stationary phase composition is much better than the selectivity of any individual stationary phase.
Diagnostic value of WT1 in neuroepithelial tumours
2008-05-07

Aims: Currently, clinical trials using WT1 (Wilms tumour gene) peptide vaccines are conducted in haematopoietic malignancies and solid cancers. Single reports showed that the Wilms tumour gene product WT1 is also expressed in astrocytic neoplasms. Our aim was to investigate WT1 expression in a large cohort of various neuroepithelial tumours of different World Health Organization (WHO) grades and in normal central nervous system (CNS) tissue specimens to test its potential value as a diagnostic marker. Methods: Specimens were assessed by RT‐PCR, Western blotting and immunohistochemistry. The samples investigated in our study consisted of 334 human neuroepithelial tumours, among those 33 oligodendrogliomas, 219 astrocytomas (including 105 glioblastomas) and 47 ependymomas. Results: Our results showed a de novo WT1 expression in neuroepithelial tumours. In diffuse astrocytomas and ependymomas, WT1 expression increased significantly with the grade of malignancy. In contrast, no significant difference was seen between WHO grade‐II and ‐III oligodendrogliomas. Controlling for WHO grade, the comparison of oligodendrogliomas with ependymal and astrocytic tumours showed higher expression values for the latter. Conclusions: Our study shows that WT1 is expressed de novo in numerous neuroepithelial tumours and increases with the grade of malignancy. These results suggest an important role of WT1 in tumourigenesis and progression in human brain tumours.
Antifungal agents – clinical pharmacokinetics and drug interactions
2008-05-08

Summary Achievement of therapeutic drug levels appears to be mandatory when antifungal agents are used for the treatment of manifest mycoses. Based on the marked interindividual variability of trough levels, Therapeutic Drug Monitoring is of increasing concern during treatment with itraconazole, voriconazole or posaconazole. In addition, a broad spectrum of potential drug interactions has to be kept in mind during triazole treatment. In contrast, echinocandins reveal a more comfortable class of antifungal agents in this regard with no obvious incidence of nephrotoxic side effects compared to amphotericin B and its lipid formulations.
Fragment reconstruction of coronary arteries using transesophageal echocardiography for coronary diagnostics
2008-05-08

FRC-TEE is a potential method for diagnosing coronary artery disease. FRC-TEE and angiography yield comparable findings during the evaluation of coronary lesions. Further investigations are needed to verify the encouraging findings and define FRC-TEE's applications.
Short-term treatment with risperidone or haloperidol in first-episode schizophrenia: 8-week results of a randomized controlled trial within the German Research Network on Schizophrenia
2008-05-09

Patients with first-episode schizophrenia appear to respond to lower doses of neuroleptics, and to be more sensitive to developing extrapyramidal side-effects. The authors therefore compared in such patients the efficacy and extrapyramidal tolerability of comparatively low dosages of the atypical neuroleptic risperidone and of the conventional neuroleptic haloperidol. Risperidone was hypothesized to have better extrapyramidal tolerability and efficacy in treating negative symptoms. Patients were randomly assigned under double-blind conditions to receive risperidone (n=143) or haloperidol (n=146) for 8 wk. The primary efficacy criterion was the estimated difference in the mean change in the Positive and Negative Symptom Scale (PANSS) negative score between treatment groups; secondary efficacy criteria were changes on the PANSS total score and other PANSS subscores, and several other measures of psychopathology and general functioning. The primary tolerability criterion was the difference in baseline-adjusted occurrence rates of extrapyramidal side-effects measured with the Simpson-Angus Scale (SAS) compared between treatment groups. The main hypothesis was that risperidone would be superior in terms of improving negative symptoms and lowering the risk of extrapyramidal symptoms. Secondary tolerability criteria were the other extrapyramidal symptoms, measured with the Hillside Akathisia Scale (HAS) and the Abnormal Involuntary Movement Scale (AIMS). The average mean daily doses were 3.8 mg (s.d.=1.5) for risperidone and 3.7 mg (s.d.=1.5) for haloperidol. There were similar, significant improvements in both treatment groups in the primary and secondary efficacy criteria. At week 8 nearly all scores of extrapyramidal side-effects indicated a significantly higher prevalence of extrapyramidal side-effects with haloperidol than with risperidone [SAS: risperidone 36.5% of patients; haloperidol 51.5% of patients; likelihood ratio test, chi2(1)=7.8, p=0.005]. There were significantly fewer drop-outs [risperidone n=55, drop-out rate=38.5%; haloperidol n=79, drop-out rate=54.1%, chi2(1)=7.1, p=0.009] and a longer non-discontinuation time [risperidone: average of 50.8 d to drop-out; haloperidol: average of 44.0 d to drop-out; log rank test, chi2(1)=6.4, p=0.011] in the risperidone group. Risperidone and haloperidol appear to be equally effective in treating negative and other symptoms of first-episode schizophrenia. Risperidone has better extrapyramidal tolerability and treatment retention rate than the equivalent dose of haloperidol in these patients.
A Connection between the Mitochondrial Permeability Transition Pore, Autophagy, and Cerebral Amyloidogenesis
2008-05-09

In a drug reprofiling attempt, we explored novel neuroprotective properties of 4-azasteroids by synthesizing chemical affinity tags capturing adenine nucleotide translocator-1, as a potential target. Dutasteride inhibits the mitochondrial transition pore and induces an increase of autophagosomal structures in human cell lines. In vivo, a surprising reduction of the beta-amyloid plaque load in a model for cerebral amyloidosis appears to connect release of neurotoxic peptides, mitochondrial apoptosis and autophagy.
Effect of relative humidity on the hydrophilicity of unset elastomeric impression materials.
2008-05-09

This study aimed to analyze the effect of relative humidity (RH) on the initial hydrophilicity of unset elastomeric dental impression materials. Initial water contact angles were studied on thin unset films of 1 polyether and 4 polyvinyl siloxane (PVS) impression materials at 20%, 50%, and 80% RH by high-resolution drop shape analysis. One of 4 PVS materials reached the polyether's initial hydrophilicity. This PVS showed increased hydrophilicity with increasing RH. The initial hydrophilicity of impression materials can be influenced by the RH level. Accounting for RH will enhance the clinical relevance of hydrophilicity studies.
Titanium Phthalocyanines with Axial Phenylenevinylenes
2008-05-09

Abstract The synthesis of soluble titanium(IV) phthalocyanines, axially substituted with phenylenevinylenes (PVs) (R x PcTiX), is described. The reaction of peripherally tetra‐ and octasubstituted (phthalocyaninato)titanium oxides (R x PcTiO) 1 – 3 with chelating PV‐diols 4a – 4c leads to the formation of axially substituted R x PcTiX 5 – 7 . All compounds were characterized by IR, UV/Vis, MS, and 1 H NMR spectroscopy. Pcs 5 – 7 dissolved in dichloromethane are stable in the dark. The stability of solutions of 5 – 7 in sunlight depends on the nature of the peripheral substituents in the Pc ring and the chain length of the axial PV substituents.(© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2008)
Plant plasma membrane water channels conduct the signalling molecule H2O2
2008-05-12

H2O2 is a relatively long-lived reactive oxygen species that signals between cells and organisms. H2O2 signalling in plants is essential for response to stress, defence against pathogens and the regulation of programmed cell death. Although H2O2 diffusion across membranes is often considered as a passive property of lipid bilayers, native membranes represent significant barriers for H2O2. In the present study we addressed the question of whether channels might facilitate H2O2 conduction across plasma membranes. The expression of several plant plasma membrane aquaporins in yeast, including PIP2;1 from Arabidopsis (where PIP is plasma membrane intrinsic protein), enhanced the toxicity of H2O2 and increased the fluorescence of dye-loaded yeast when exposed to H2O2. The sensitivity of aquaporin-expressing yeast to H2O2 was altered by mutations that alter gating and the selectivity of the aquaporins. The conduction of water, H2O2 and urea was compared, using molecular dynamics simulations based on the crystal structure of SoPIP2;1 from spinach. The calculations identify differences in the conduction between the substrates and reveal channel residues critically involved in H2O2 conduction. The results of the calculations on tetramers and monomers are in agreement with the biochemical data. Taken together, the results strongly suggest that plasma membrane aquaporin pores determine the efficiency of H2O2 signalling between cells. Aquaporins are present in most species and their capacity to facilitate the diffusion of H2O2 may be of physiological significance in many organisms and particularly in communication between different species.
Bimanual Response Grouping in Dual-Task Paradigms
2008-05-12

In three experiments we measured response time (RT) and peak force (PF) to investigate the grouping of left- and right-hand key press responses in a dual-task paradigm involving two independent go/no-go tasks. Within each task, a go stimulus within one of two modalities (i.e., visual versus auditory) required a response by one hand. In Experiment 1 with simultaneous go stimuli in the two tasks, responses appeared to be grouped in approximately 75–80% of trials, compared with nearly 100% grouping in a single-task condition requiring bimanual responses to the onset of any stimulus in either modality. In Experiment 2 with stimulus onset asynchronies (SOAs) of 0–400 ms between the two go stimuli, response grouping clearly declined as SOA increased, although some grouping was still evident even at the longest SOA. The same pattern was observed in Experiment 3 with the same range of SOAs but unpredictable stimulus order, suggesting that grouping is not strongly dependent on prior knowledge of the likely response order. These results emphasize the pervasiveness of response grouping in bimanual dual-task RT paradigms and provide useful clues as to its nature.
Motor limitation in dual-task processing with different effectors
2008-05-12

According to the extended bottleneck model, dual-task interference does not arise only from a central bottleneck but also from processing limitations at the motor stage. Evidence for this assumption has previously been found only for same-effector tasks but not for different-effector tasks. In order to examine the existence of motor interference with different effectors, we used the psychological refractory period paradigm and employed response sequences of different length in Task 1 (R1 sequence length). Experiment 1 incorporated vocal response sequences in Task 1 and a manual response in Task 2. In Experiment 2, the assignment of the effectors to the two tasks was reversed. In both experiments, the long R1 sequence prolonged reaction time for Task 2 (RT2), and this effect was reduced with decreasing temporal overlap of the two tasks. Thus, the present experiments demonstrate motor interference between different-effector tasks. This interference may be due to on-line programming or to central response monitoring.
Bounds on the estimation error in the chain ladder method
2008-05-12

Buchwalder et al. (2006) have illustrated that there are different approaches for the derivation of an estimate for the parameter estimation error in the distribution-free chain ladder reserving method. In this paper, we demonstrate that these approaches provide estimates that are close to each other for typical parameters. This is carried out by proving upper and lower bounds.
Analysis of complex protein kinase B signalling pathways in human prostate cancer samples
2008-05-12

OBJECTIVE To provide a rational basis for targeted treatment approaches in prostate cancer deregulation of the phosphatidylinositol‐3‐kinase (PI3K)/protein kinase B (PKB/Akt) system was analysed. PATIENTS AND METHODS In all, 45 patients with primary localized prostate cancer that underwent radical prostatectomy were included in the present study. Upon scoring of the pathological grade, expression and phosphorylation levels of PKB/Akt and relevant downstream targets were determined in tissue specimens by immunohistochemistry using specific antibodies against PTEN, PKB/Akt, its downstream targets, and the respective phosphorylated proteins. RESULTS Most patients (&gt;90%) had up‐regulated expression and/or phosphorylation of PKB/Akt in the malignant tissue compared with the surrounding benign tissue, with a higher prevalence of increased phosphorylated PKB/Akt in patients with Gleason scores of ≥6 (100%) compared with those with Gleason scores of 4–5 (five of 13 patients), and in particular in patients with clinical progression. Up‐regulated phosphorylation of PKB/Akt occurred either in association with loss or inactivation of PTEN or in a PTEN‐independent manner. Enhanced phosphorylation levels of the PKB/Akt substrates glycogen synthase kinase 3, the mammalian target of rapamycin or the forkhead transcription factor like 1 (FKHRL1) were found in 29%, 42% and 40% of the tumours, respectively. Of these, only increased phosphorylated‐FKHRL1 levels correlated with clinical progression. Interestingly, 80% of patients had a notable overexpression but not phosphorylation of the eucaryotic initiation factor 4E binding protein. CONCLUSION Deregulation of p‐PKB/Akt is common in localized prostate cancer and has a putative value as predictive marker for disease progression and as therapeutic target. However, as a consequence of the substantial heterogeneity in the expression and phosphorylation levels of relevant PKB/Akt effector pathways, for a rational use of specified inhibitors of the PI3K/PKB system a complex pattern testing of expression and activity of the respective target proteins for prediction of efficacy and prognosis seems mandatory.
Automated overexpression and isotopic labelling of biologically active oncoproteins in the cyanobacterium Anabaena sp. PCC 7120
2008-05-12

We have previously shown the cyanobacterium Anabaena sp. PCC 7120 to be a suitable host for the production of isotopically labelled recombinant proteins using the nitrate‐inducible nir expression system. However, the expression of toxic proteins such as oncoproteins proved to be difficult, as expression levels decreased shortly after induction, while growth continued. To overcome this limitation, we have developed a method of auto‐induction of the nir promoter in which cells are grown to high cell density in a bioreactor in the presence of ammonium and nitrate. Since ammonium is the preferred nitrogen source and acts as a repressor of the nir promoter, induction occurs only when the ammonium had been depleted. Using this novel auto‐induction method, both oncoproteins E6 and gankyrin were expressed at high levels in a folded conformation and were shown to be biologically active after purification. Furthermore, under similar conditions of growth in auto‐inducing medium, the use of 15 N‐ and 13 C‐labelled mineral salts yielded isotopic enrichment of these proteins at levels above 95%, making them suitable for NMR‐based structural analysis in a cost‐effective manner.
Cerebellar-dependent motor learning is based on pruning a Purkinje cell population response
2008-05-14

The improvement of motor behavior, based on experience, is a form of learning that is critically dependent on the cerebellum. A well studied example of cerebellar motor learning is short-term saccadic adaptation (STSA). In STSA, information on saccadic errors is used to improve future saccades. The information optimizing saccade metrics is conveyed by Purkinje cells simple spikes (PC-SS) because they are the critical input to the premotor circuits for saccades. We recorded PC-SS of monkeys undergoing STSA to reveal the code used for improving behavior. We found that the discharge of individual PC-SS was unable to account for the behavioral changes. The PC-SS population burst (PB), however, exhibited changes that closely paralleled the qualitatively different changes of saccade kinematics associated with gain-increase and gain-decrease STSA, respectively. Gain-increase STSA, characterized by an increase in saccade duration, replicates the relationship between saccade duration and the end of the PB valid for unadapted saccades. In contrast, gain-decrease STSA, which sports normal saccade duration but reduced saccadic velocity, is characterized by a PB that ends well before the adapted saccade. This suggests that the duration of normal as well as gain-increased saccades is determined by appropriately setting the end of PB end. However, the duration of gain-decreased saccades is apparently not modified by the cerebellum because the PB signals ends too early to determine saccade end. In summary, STSA, and most probably cerebellar-dependent learning in general, is based on optimizing the shape of a PC-SS population response.