julilili42/papers huggingface dataset:
MgB2multifilamentary tapes: microstructure, chemical composition and superconducting properties
2006-07-31

Multifilamentary Ni-sheathed Cu-stabilized MgB2 tapes with a critical current density of 2.0 × 105 A cm−2 (at 20 K and 1 T) were prepared by a powder in tube technique, using pre-reacted MgB2 powders. The microstructure and chemical composition of the superconducting core and the MgB2–Ni interface were studied using SEM, EPMA and TEM. A quick, reliable and standard-less method of B quantification using SEM-EDX is established for the analysis of MgB2 wires and tapes. Carbon-contamination-free sample preparation was crucial for the analysis of boron.
Synthese und Kristallstruktur von Na3[W3Cl13]
2006-07-31

Abstract Synthesis and Crystal Structure of Na 3 [W 3 Cl 13 ] A solid state reaction of tungsten(IV)chloride and sodium chloride yielded black plate‐like crystals of Na 3 [W 3 Cl 13 ]. The structure of this compound was determined by single crystal X‐ray diffraction. Na 3 [W 3 Cl 13 ] crystallizes in the monoclinic space group P 2 1 / c with a = 9.093(1) Å, b = 23.851(4) Å, c = 9.155(1) Å, β = 120.26(1)°, and Z = 4. The crystal structure contains trigonal tungsten clusters ( = 2.737(1) Å) surrounded by chlorine atoms. The molecular [W 3 (μ 3 ‐Cl)(μ‐Cl) 3 Cl 9 ] 3− cluster anions are forming layers parallel to the ac‐plane, sodium ions are located in and in between the layers.
Rare‐Earth Nickel Nitridoborates with (BN) Anions: Characterized RENi(BN) and Anticipated REM(BN) Compounds
2006-07-31

Abstract The compounds RE Ni(BN) with RE = Y, La, Ce, Pr, Tm and Yb were synthesized by solid state reactions from metal powders and α‐BN at temperatures between 1000° and 1200 °C. In addition, the mixed phases (Ca,Yb)Ni(BN) and (Ca,Tm)Ni(BN) were synthesized. All products were characterized by powder XRD measurements and indexed isotypic with the structure of CaNi(BN), consistent with the tetragonal space group P4/nmm. The bonding conditions of the (BN) anion are discussed in a perspective view on new nitridoborate compounds RE M(BN) containing transition metal atoms (M) other than Ni.
The Kölliker‐Fuse nucleus gates the postinspiratory phase of the respiratory cycle to control inspiratory off‐switch and upper airway resistance in rat
2006-08-01

Abstract Lesion or pharmacological manipulation of the dorsolateral pons can transform the breathing pattern to apneusis (pathological prolonged inspiration). Apneusis reflects a disturbed inspiratory off‐switch mechanism (IOS) leading to a delayed phase transition from inspiration to expiration. Under intact conditions the IOS is irreversibly mediated via activation of postinspiratory (PI) neurons within the respiratory network. In parallel, populations of laryngeal premotoneurons manifest the IOS by a brief glottal constriction during the PI phase. We investigated effects of pontine excitation (glutamate injection) or temporary lesion after injection of a GABA‐receptor agonist (isoguvacine) on the strength of PI‐pool activity determined from respiratory motor outputs or kinesiological measurements of laryngeal resistance in a perfused brainstem preparation. Glutamate microinjections into distinct parts of the pontine Kölliker‐Fuse nucleus (KF) evoked a tonic excitation of PI‐motor activity or sustained laryngeal constriction accompanied by prolongation of the expiratory phase. Subsequent isoguvacine microinjections at the same loci abolished PI‐motor or laryngeal constrictor activity, triggered apneusis and established a variable and decreased breathing frequency. In summary, we revealed that excitation or inhibition of defined areas within the KF activated and blocked PI activity and, consequently, IOS. Therefore, we conclude, first, that descending KF inputs are essential to gate PI activity required for a proper pattern formation and phase control within the respiratory network, at least during absence of pulmonary stretch receptor activity and, secondly, that the KF contains large numbers of laryngeal PI premotor neurons that might have a key role in the regulation of upper airway resistance during reflex control and vocalization.
MATHEMATICAL MODELING OF THE IMPACT OF MALARIA VACCINES ON THE CLINICAL EPIDEMIOLOGY AND NATURAL HISTORY OF PLASMODIUM FALCIPARUM MALARIA: OVERVIEW
2006-08-01

We report a major project to develop integrated mathematical models for predicting the epidemiologic and economic effects of malaria vaccines both at the individual and population level. The project has developed models of the within-host dynamics of Plasmodium falciparum that have been fitted to parasite density profiles from malariatherapy patients, and simulations of P. falciparum epidemiology fitted to field malariologic datasets from a large ensemble of settings across Africa. The models provide a unique platform for predicting both the short- and long-term effects of malaria vaccines on the burden of disease, allowing for the temporal dynamics of effects on immunity and transmission. We discuss how the models can be used to obtain robust cost-effectiveness estimates for a wide range of malaria vaccines and vaccination delivery strategies in different eco-epidemiologic settings. This paper outlines for a non-mathematical audience the approach we have taken and its underlying rationale.
Cross‐modal plasticity of the motor cortex while listening to a rehearsed musical piece
2006-08-01

Abstract Learning a musical piece requires the development of a strong linkage between sensory and motor representations. Audition plays a central role and a tight cortical auditory–motor corepresentation is a characteristic feature of music processing. Recent works have indicated the establishment of a functional connection between auditory and motor cortices during the learning of a novel piece, although no causal relation has yet been demonstrated. Here transcranial magnetic stimulation of the cortical motor representation involved in musical performance was used to test excitability changes in piano players during auditory presentation of a rehearsed and a non‐rehearsed piece. Results showed an increased motor excitability for the rehearsed but not for the non‐rehearsed piece. Moreover, we observed an increase of excitability over time as intracortical facilitation was already present after 30 min of training whereas cortico‐spinal facilitation increased after a longer training period (5 days).
RELATIONSHIP BETWEEN THE ENTOMOLOGIC INOCULATION RATE AND THE FORCE OF INFECTION FOR PLASMODIUM FALCIPARUM MALARIA
2006-08-01

We propose a stochastic model for the relationship between the entomologic inoculation rate (EIR) for Plasmodium falciparum malaria and the force of infection in endemic areas. The model incorporates effects of increased exposure to mosquito bites as a result of the growth in body surface area with the age of the host, naturally acquired pre-erythrocytic immunity, and the reduction in the proportion of entomologically assessed inoculations leading to infection, as the EIR increases. It is fitted to multiple datasets from field studies of the relationship between malaria infection and the EIR. We propose that this model can account for non-monotonic relationships between the age of the host and the parasite prevalence and incidence of disease. It provides a parsimonious explanation for the faster acquisition of natural immunity in adults than in children exposed to high EIRs. This forms one component of a new stochastic model for the entire transmission cycle of P. falciparum that we have derived to estimate the potential epidemiologic impact of malaria vaccines and other malaria control interventions.
A MODEL FOR NATURAL IMMUNITY TO ASEXUAL BLOOD STAGES OF PLASMODIUM FALCIPARUM MALARIA IN ENDEMIC AREAS
2006-08-01

Most mathematical models for acquired immunity to Plasmodium falciparum consider effects of immunity on duration of infection and infectiousness, but do not consider the most evident effect of immunity, which is to reduce parasite densities. Few attempts have been made to fit such models to field data. We propose a stochastic simulation model to predict the distributions of P. falciparum parasite densities in endemic areas, in which acquired immunity acts by reducing parasite densities. We have fitted this model to age-specific prevalence and geometric mean densities from settings in Ghana, Nigeria, and Tanzania. The model appears to reproduce reasonably well the parasitologic patterns seen in malariologic surveys in endemic areas and is appropriate for predicting the impact of interventions such as vaccination in the context of continual exposure to P. falciparum .
Cell-cycle progression and response of germ cell tumors to cisplatin in vitro
2006-08-01

Testicular germ cell tumors (GCTs) are highly sensitive to cisplatin-based chemotherapy. It has been suggested that the chemosensitivity of GCTs can be partially attributed to the preference of apoptosis induction over a p21-mediated G1/S phase cell-cycle arrest following induction of p53. Since cell-cycle progression can be manipulated by a growing number of targeted agents, a thorough understanding of the impact of cell-cycle progression on drug-induced cell death might help to enhance the efficacy of chemotherapy. The aim of this study was to assess the cell-cycle dependence of cisplatin-induced cell death in an in vitro model of GCTs. Cell-cycle progression and induction of apoptosis were assessed by flow cytometry and Western blot analysis of PARP cleavage in the GCT derived cell lines, NT2 and 2102 EP, and compared with the breast carcinoma cell line MCF-7. Response to treatment was assessed in different phases of the cell cycle after synchronization by serum depletion and contact inhibition. Following cisplatin exposure, unsynchronized cells accumulated in G2/M after 28 h. This arrest was reversible at sublethal cisplatin doses (0.5-4.5 microM for 2 h). At higher concentrations, cells accumulated in G2 and died in G2/M-arrest. A 2-h exposure of cells in G2/M with 10 microM cisplatin resulted in a higher apoptotic index 70 h after treatment (74 and 70% for NT2 and 2102 EP, respectively) compared to treatment in G1/S (34 and 38%). Synchronized cells treated in G1 showed PARP cleavage after 48 h following cisplatin exposure, whereas treatment in G2 resulted in PARP cleavage already after 24 h. Cisplatin-induced cell death in GCTs is highly dependent on cell-cycle phase. All crucial events are restricted to the G2/M phase: cisplatin-induced DNA-damage is sensed, the apoptotic process is initiated and eventually executed in this phase of the cell cycle. The cells are most sensitive to cisplatin in this phase of the cell cycle. As far as the development of targeted agents is concerned, inhibition of the cell cycle in G1/S phase is likely to result in a protective effect against cisplatin, whereas agents arresting cells in G2/M may exert a synergistic effect.
IGF-independent effects of IGFBP-2 on the human breast cancer cell line Hs578T
2006-08-01

There is evidence that insulin-like growth factor-binding protein (IGFBP-2), a modulator of the actions of IGFs, also has IGF-independent effects in human tumor cell lines. These involve specific binding of IGFBP-2 to α5β1-integrin, followed by alterations in the phosphorylation status of downstream signaling molecules. Previously, IGFBP-2 has also been shown to be associated with cell proliferation, adhesion and migration. Here, we investigated direct effects of IGFBP-2 on apoptosis and alterations in the expression of related proteins. The breast cancer cell line Hs578T, which shows no IGFBP-2 production of its own and is independent of the IGF-I receptor, was treated with human recombinant IGFBP-2 in order to study the changes in gene expression induced by IGFBP-2. The methods employed for this purpose were oligonucleotide microarrays, real-time RT-PCR, western blotting, and immunoassays. Out of the 440 genes covered by the Oligo GEArray Human Cancer Microarray OHS-802, the expression of 77 genes was directly influenced by IGFBP-2. By the use of real-time quantitative RT-PCR, the gene expression of Nuclear Factor (NF)κB, p53, transforming growth factor β (TGF β-1), LAMB1 (Laminin, Beta 1), Bcl-2, and IIp45 was found to be significantly upregulated (by 1.2- to 3.05-fold; all P &lt; 0.001). Accordingly, NFκB, p53, and TGF β-1 proteins, as measured by Western blotting and immunoassay, were upregulated &gt; 1.5-fold. By using an ELISA-based and a flow cytometry-based apoptosis assay, IGFBP-2 was found to have a pro-apoptotic effect on Hs578T cells. Our results suggest that IGFBP-2-induced gene expressions are of functional significance for proliferation, cell adhesion, cell migration and apoptosis, and showed that IGFBP-2 can promote apoptosis in tumor cells independent of IGF.
Conduction model of SnO2 thin films based on conductance and Hall effect measurements
2006-08-01

Thin and porous SnO2 films (70nm thick with grain size between 10 and 30nm) have been prepared by e-beam evaporation onto alumina substrate provided with platinum electrodes. The Ohmic character of the contacts was preserved in all measurement conditions utilized for investigations. The dependence of electrical conduction on the composition of the ambient atmosphere has been studied by means of Hall and four point conductance measurements. The experiments were performed in different gas atmospheres containing N2, O2, and CO and at different operation temperatures (between room temperature and 420°C). A relatively low effective mobility (5–30cm2V−1s−1) and a high charge carrier effective concentration (1018–1019cm−3) were deduced when using the single crystals recipe, as required by the established models for granular materials. The analysis of these experimental data showed the inadequacy of the geometrical models and effective medium theories to correctly extract the electrokinetic parameters from conductance and Hall measurements in the case of gas sensitive layers and to predict their temperature and gas composition dependences. The conventional approach fails because it considers the samples at different temperatures as one physical system while, in fact, the surface chemistry in oxygen atmosphere leads to new trap generation, which is equivalent to the doping level modification. The use of a nonconventional approach, taking into account the film interaction with the ambient through quasichemical equations, and associated mass action laws together with the surface scattering influence on the carrier mobility allowed for the understanding of the involved mechanisms and good fits for the experimental data.
Discovery of very high energyγ-ray emission from the BL Lacertae object H 2356-309 with the HESS Cherenkov telescopes
2006-08-01

The extreme synchrotron BL Lac object H 2356-309, located at a redshift of z = 0.165, was observed from June to December 2004 with a total exposure of 40 h live-time with the HESS (High Energy Stereoscopic System) array of atmospheric-Cherenkov telescopes (ACTs). Analysis of this data set yields, for the first time, a strong excess of 453 -rays (10 standard deviations above background) from H 2356-309, corresponding to an observed integral flux above 200 GeV of I(&gt;200 GeV) = (4.1 0.5) 10-12 cm-2 s-1 (statistical error only). The differential energy spectrum of the source between 200 GeV and 1.3 TeV is well-described by a power law with a normalisation (at 1 TeV) of N0 = (4.1 0.5) 10-13 cm-2 s-1 TeV-1 and a photon index of = . H 2356-309 is one of the most distant BL Lac objects detected at very-high-energy -rays so far. Results from simultaneous observations from ROTSE-III (optical), RXTE (X-rays) and NRT (radio) are also included and used together with the HESS data to constrain a single-zone homogeneous synchrotron self-Compton (SSC) model. This model provides an adequate fit to the HESS data when using a reasonable set of model parameters.
MATHEMATICAL MODEL OF THE FIRST WAVE OF PLASMODIUM FALCIPARUM ASEXUAL PARASITEMIA IN NON-IMMUNE AND VACCINATED INDIVIDUALS
2006-08-01

We present a dynamic model of the highly pathogenic first wave of Plasmodium falciparum asexual parasitemia in non-immune persons. The model was successfully fitted to malaria therapy data. This required four case-specific parameters: the basic two-day multiplication factor, the time of onset of adaptive immunity, and the effective dose 50 densities for the innate and adaptive immune responses, respectively. All four parameters show large case-dependent variation that is mainly attributable to host factors. According to the model, the maximum value of the first wave is controlled mainly by the innate immune response. We used the model to explore the expected effects of vaccines targeting the parasite’s asexual blood stages on the basis of what we consider to be the biologically most plausible assumptions concerning the parameter modifications induced by vaccination. According to our simulations, the benefit of antiparasitic vaccination is strongly host dependent and vaccine efficacy at low immunogenicity is much larger against severe disease than against fever. This has implications for the early testing of the protective efficacy of a vaccine in humans.
Identification of blottin: A novel gastric trefoil factor family‐2 binding protein
2006-08-01

Abstract The trefoil factor family (TFF) peptides are important in gastro‐intestinal mucosal protection and repair. Their mechanism of action remains unclear and receptors are sought. We aimed to identify and characterise proteins binding to TFF2. A fusion protein of mouse TFF2 with alkaline phosphatase was generated and used to probe 2‐D protein blots of mouse stomach. The resulting spots were analysed by MS. The protein identified was characterised by bioinformatics, rapid amplification of cDNA ends, in situ hybridisation (ISH) and immunohistochemistry (IHC). Functional assays were performed in gastrointestinal cell lines. A single major murine protein was identified and named blottin. It was previously unknown as a translated product. Blottin is also present in rat and human; the latter gene is also known as GDDR. The predicted full‐length proteins are 184 amino acids long (20 kDa), reducing to 164 amino acids (18 kDa) after signal peptide cleavage. ISH of gastrointestinal tissues shows abundant blottin mRNA in gastric surface and foveolar epithelium. IHC shows cytoplasmic staining for blottin protein, and by immunoelectron microscopy in mucus granules and Golgi stacks. Previous work showed that blottin is down‐regulated in gastric cancers. Blottin contains a BRICHOS domain, and has 56% similarity with gastrokine‐1. Cultured HT‐29 cells express blottin and show increased DNA synthesis with antiblottin antibody; however, this effect is reversed by the immunising peptide. We have identified and characterised a TFF2‐binding protein produced by gastric epithelium. Blottin may play a role in gastrointestinal mucosal protection and modulate gut epithelial cell proliferation.
Interobserver and Intraobserver Agreement of Lenke and King Classifications for Idiopathic Scoliosis and the Influence of Level of Professional Training
2006-08-01

The results confirm that both classifications have a good reliability. On nonmeasured radiographs, the degree of professional training and the measurement process seem to influence the outcome. On premeasured radiographs, the interobserver agreement does not seem to be influenced by the level of professional training.
Spectrin mutations in spinocerebellar ataxia (SCA)
2006-08-01

Abstract Recently, βIII spectrins have been recognized as ataxia disease genes, with the identification by Ikeda and co‐workers of pathogenic mutations in the SPTBN2 gene in three large (and mapped) SCA5 families of American and European origin. (1) With their discovery, the large “Lincoln” family has been traced back to the underlying genetic defect for the slowly progressive cerebellar ataxia. In addition, the involvement of this component of the cytoskeleton directs attention towards the possible role of organelle stability during neurodegeneration. The findings suggest that the mechanical properties of neurons and their dynamics may be as important as altered Ca 2+ homeostasis, transcriptional dysregulation, and impaired protein degradation in neurodegeneration conditions. BioEssays 28: 785–787, 2006. © 2006 Wiley Periodicals, Inc.
Integral pumping test analyses of linearly sorbed groundwater contaminants using multiple wells: Inferring mass flows and natural attenuation rates
2006-08-01

This paper addresses a field‐scale application of the integral pumping test (IPT) method, which is a method for quantitative characterization of contaminant plumes (e.g., benzene, toluene, ethylbenzene, and xylenes (BTEX), chlorinated hydrocarbons, and polyaromatic hydrocarbons) in groundwater. We extend the associated analytical framework by formal consideration of linear, instantaneous sorption/retardation and provide novel nonrecursive analytical solutions for estimation of field‐scale contaminant mass flows. We find that estimates of the average concentration obtained through IPTs are independent of the retardation factor under equilibrium conditions, although linear retardation due to sorption decreases the investigation volume in comparison with the nonretarded case. Furthermore, whereas previous studies were based on single‐well analyses, we present in this paper developments relevant for multiple‐well analyses by introducing a simple, analytical multiple‐well framework for evaluation of IPTs considering overall water budgets. Although single‐well analyses provide consistent results in isolation, their applicability on multiwell systems suffer from the fact that the theory does not include mass balance considerations for the gallery of wells that constitutes a control plane. Through application of the developed multiple‐well methods to measurement data from the field we show that the estimated total mass flows across well galleries can differ considerably from corresponding estimates using single‐well methods, which to some extent, also influences natural attenuation (NA) rate estimates. We believe that the developments presented here can provide a useful basis for biogeochemical studies of field‐scale NA processes, including assessments of changes in isotope ratios.
Long-Term Results after Metatarsal Head Resection in the Treatment of Rheumatoid Arthritis
2006-08-01

Background: In this retrospective study, both the patients' and surgeons' satisfaction with resection of the first through fifth metatarsal heads for long-standing rheumatoid forefoot deformity was evaluated. Methods: Thirty-four patients (56 feet) had first through fifth metatarsal head resection. After a mean time of 5.3 years, 39 feet (69.6%) (26 patients) were examined clinically and radiographically. Results: The complication rate was 14% (8 of 56). There were four superficial and four deep wound infections. Plantar pressure pain under the resected metatarsal heads occurred in six feet. Most patients rated their cosmetic and functional results as good. Eighteen percent of patients (6 of 34) were satisfied and 78% (26 of 34) were satisfied with reservations. Thirty-three percent of patients (11 of 34) were pain free and 53% (18 of 34) had mild pain. The surgeons assessment of the patients' anatomical correction (cosmesis) was good in 90% (50 of 56) and poor in 10% (6 of 56). Conclusions: Our results, which are comparable to those of other studies, confirm the success of metatarsal head resection for the treatment of inflammatory forefoot destruction in rheumatoid arthritis to correct deformity, reduce pain, improve ambulation, and offer the patient a greater variety of shoewear.