julilili42/papers huggingface dataset:
Interplay between O2 and SnO2: Oxygen Ionosorption and Spectroscopic Evidence for Adsorbed Oxygen
2006-09-06

Abstract Tin dioxide is the most commonly used material in commercial gas sensors based on semiconducting metal oxides. Despite intensive efforts, the mechanism responsible for gas‐sensing effects on SnO 2 is not fully understood. The key step is the understanding of the electronic response of SnO 2 in the presence of background oxygen. For a long time, oxygen interaction with SnO 2 has been treated within the framework of the “ionosorption theory”. The adsorbed oxygen species have been regarded as free oxygen ions electrostatically stabilized on the surface (with no local chemical bond formation). A contradiction, however, arises when connecting this scenario to spectroscopic findings. Despite trying for a long time, there has not been any convincing spectroscopic evidence for “ionosorbed” oxygen species. Neither superoxide ions O 2 − , nor charged atomic oxygen O, − nor peroxide ions O 2 2− have been observed on SnO 2 under the real working conditions of sensors. Moreover, several findings show that the superoxide ion does not undergo transformations into charged atomic oxygen at the surface, and represents a dead‐end form of low‐temperature oxygen adsorption on reduced metal oxide.
Sorption of Heterocyclic Organic Compounds to Reference Soils:  Column Studies for Process Identification
2006-09-06

In this study, the sorption behavior of a wide variety of N-, S-, and O-heterocyclic compounds (NSOs) to reference soils (Eurosoils 1-5) was characterized by a soil column chromatography (SCC) approach. The major goal was to identify the compound specific and environmental factors influencing sorption processes. The sorption of S- and O-heterocyclic compounds (thiophene, benzothiophene, 5-methylbenzo[b]thiophene, benzofuran, 2-methylbenzofuran, and 2,3-dimethylbenzofuran) was generally controlled by nonspecific interactions with soil organic carbon (OC). With regard to non-ionizable N-heterocyclic compounds, pyrrole, 1-methylpyrrole, and pyrimidine were hardly retarded in any soil. The sorption of indole, 2-hydroxyquinoline, and benzotriazole was dominated by specific interaction (e.g., complexation of surface-bound cations) rather than partition to soil OC. The sorption of ionizable N-heterocyclic compounds (quinoline, isoquinoline, quinaldine, 2-methylpyridine, and pyridine) can be described by a conceptual model including partitioning to soil OC, cation exchange, and an additional sorption process (probably surface complexation of the neutral species). Cation exchange was usually the dominant mechanism in the sorption of ionizable compounds if the protonated fraction of the compound exceeded 5%. Otherwise, surface complexation became dominant. Soil pH was the most important factor influencing the sorption of ionizable NSOs. Our study suggests that a fairly precise assessment of sorption in most soils can be expected for N-, S-, and O-heterocyclic compounds if the three sorption mechanisms are taken into accountwhere appropriate. Deviations from this behavior indicated special cases where additional soil specific properties (e.g., accessible surface, CEC, charge density) need to be considered such as for 2-methylpyridine and pyridine sorption to Eurosoil 1.
Successful treatment of disseminated mucormycosis with a combination of liposomal amphotericin B and posaconazole in a patient with acute myeloid leukaemia
2006-09-06

Abstract The combination of resection of infected tissue and antifungal therapy is the treatment of choice in mucormycosis. In disseminated mucormycosis, where surgery is impossible, the mortality is almost 90%. We report the first case of disseminated mucormycosis that was cured with a combination therapy of liposomal amphotericin B and posaconazole without surgical intervention.
The new pre-cataclysmic\\nbinary PG 2200+085
2006-09-06

\\n Aims.We present the results of spectroscopic- and orbit-sampled photometric\\nobservations of the faint UV-excess object PG 2200+085.\\n Methods.The optical CCD photometry observations of this object were performed\\nby the Russian-Turkish 1.5-m telescope RTT150 at the TUBITAK National \\nObservatory (Turkey). The long-slit optical spectroscopy observations\\nwith 2.6 Å resolution were carried out by 6-m telescope BTA at\\nthe Special Astrophysical Observatory (Russia).\\n Results.The\\nphotometric variations over two nights are almost sinusoidal\\nwith an amplitude and a period of\\n d. Such a light curve is typical of a detached close\\nbinary with an illumination effect or the ellipsoidal deformation of\\na secondary star. The observed spectrum clearly displays a featureless\\nblue continuum of a hot component and a rich\\nabsorption-line and molecular band K-star spectrum. The CaII line\\nprofiles with strong emission cores are remarkably similar to those of\\nV471 Tau.\\n Conclusions.We tentatively classify PG 2200+085 as a\\npre-cataclysmic binary of the V471 Tau type.\\n
Precursor frequency can compensate for lower TCR expression in T cell competition during priming in vivo
2006-09-06

Abstract The factors controlling clonal dominance of cytotoxic T lymphocyte (CTL) responses are currently not well understood. To study the functional impact of the strength of the interaction of a T cell with an antigen‐presenting cell in this context, we established a new mouse model comprised of two T cell receptor (TCR)‐transgenic strains expressing the identical TCR in differing amounts, hence providing two CTL clones with different avidities but identical specificity and affinity. Utilizing this new model, we show that upon antigen challenge higher‐avidity CTL expand at the expense of moderate‐avidity CTL in vivo if present in equal numbers. Beyond this, moderate‐avidity T cells can also contribute to a CTL response when present in excess. These results suggest that in addition to a proposed affinity/avidity threshold, the precursor frequency is important in defining clonal dominance. A new model in which TCR density and precursor frequency define the outcome of a CTL response is discussed.
Temporal and Spatial Enumeration Processes in the Primate Parietal Cortex
2006-09-07

Humans and animals can nonverbally enumerate visual items across time in a sequence or rapidly estimate the set size of spatial dot patterns at a single glance. We found that temporal and spatial enumeration processes engaged different populations of neurons in the intraparietal sulcus of behaving monkeys. Once the enumeration process was completed, however, another neuronal population represented the cardinality of a set irrespective of whether it had been cued in a spatial layout or across time. These data suggest distinct neural processing stages for different numerical formats, but also a final convergence of the segregated information to form most abstract quantity representations.
Syntheses and Structural Properties of Rare Earth Carbodiimides
2006-09-07

Crystalline samples of rare earth carbodiimides were synthesized by solid-state metathesis reactions of rare earth trichlorides with lithium cyanamide in sealed silica ampules. Two distinct structures were determined by single-crystal X-ray diffraction. The structure determined for Sm2(CN2)3 [C2/m, Z = 2, a = 14.534(2) Å, b = 3.8880(8) Å, c = 5.2691(9) Å, β = 95.96(2)°, R1 = 0.0267, and wR2 = 0.0667] was assigned for RE2(CN2)3 compounds with RE = Y, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er, and the structure determined for Lu2(CN2)3 [R32, Z = 3, a = 6.2732(8) Å, c = 14.681(2) Å, R1 = 0.0208, and wR2 = 0.0526] was assigned for the smallest rare earth ions with RE = Tm, Yb, and Lu by powder X-ray diffraction. Both types of crystal structures are characterized by layers of [NCN]2- ions whose arrangements can be derived from the motif of a closest packed layer of sticks. These layers alternate with layers of rare earth ions in a one-by-one sequence. Different tilting arrangements of the N−C−N-axes relative to the stacking directions (c) and different arrangements of RE3+ ions within metal atom layers account for the two distinct structures in which Sm3+ and Lu3+ ions adopt the coordination numbers 7 and 6, respectively.
The centromeric 11p15 imprinting centre is also involved in Silver–Russell syndrome
2006-09-08

Silver–Russell syndrome (SRS) is a heterogeneous disorder characterised by severe intrauterine and postnatal growth retardation, limb and body asymmetry, a typical facial appearance and less common dysmorphisms. Recently, epimutations and maternal duplications affecting the short arm of chromosome 11 have been shown to have a crucial role in the aetiology of the disease. Disturbances in the same genomic region cause the overgrowth disorder Beckwith–Wiedemann syndrome (BWS). In BWS, mutations in the telomeric as well as in the centromeric imprinting centres (ICR1 and ICR2) in 11p15 can be observed. In SRS, methylation defects in the imprinted region in 11p15 were considered to be restricted to the telomeric ICR1. They can be detected in about 30% of patients. This article reports on the first patient with SRS with a cryptic duplication restricted to the centromeric ICR2 domain in 11p15. The maternally inherited duplication in this patient included a region of 0.76–1 Mbp and affected the genes regulated by the ICR2, among them CDKN1C and LIT1 . This study provides evidence for a role for this imprinting centre in the aetiology of SRS and shows that SRS presents a picture genetically opposite to that of BWS.
Phylogenetic analysis of human parvovirus B19, indicating two subgroups of genotype 1 in Vietnamese patients
2006-09-08

Recently, three distinct genotypes (1, 2 and 3) of human parvovirus B19 (B19) have been identified. However, the characteristics and distribution of B19 genotypes in Vietnam have not been investigated. Phylogenetic analysis using 49 subgenomic NS1/VP1u regions and two coding NS1–VP1/VP2 regions has been applied to investigate the prevalence of B19 genotypes in Vietnamese patients co-infected with Hepatitis B virus . Genetic analysis of the subgenomic NS1/VP1u region of B19 revealed that two genotypes of B19 were identified in these populations, with predominance of genotype 1 (47/49, 96 %) followed by genotype 2 (2/49, 4 %), but not genotype 3. Further, phylogenetic analysis of subgenomic B19 genomes revealed two major subgroups within genotype 1 (B19-1A and B19-1B) with an estimated nucleotide difference of &gt;5 % between each subgroup, forming different branches. The mean percentage of amino acid variation between subgroup B19-1A and B19-1B was &gt;2 % of the NS1, VP1 and VP2 proteins. Our results indicated that two of the three known genotypes of B19 were present in Vietnamese patients, with genotype 1 predominating, and that this genotype can be classified into at least two subgroups, B19-1A and B19-1B.
Chemical induction of mixis in the rotifer Synchaeta tremula
2006-09-08

In rotifers of the genus Brachionus, a chemical factor that accumulates during population crowding is necessary and sufficient to trigger sexual reproduction (mixis). In other monogonont rotifer species, field data and some laboratory studies indicate that mixis is density-dependent; however, to date it is unknown whether this reaction is chemically mediated as in Brachionus. Here we provide experimental evidence that mixis in the rotifer Synchaeta tremula is both density-dependent and chemically mediated. S. tremula cultured at high population densities (10 individual mL−1) produced 15.4% mictic offspring, whereas those cultured at low population densities (0.25 individual mL−1) produced only 0.3% mictic offspring. Conditioned water isolated from exponentially growing mass cultures induced significantly higher levels of mixis in the offspring of individually cultured females, when compared with untreated control medium (15.7 versus 1.4% mixis). In S. tremula, the propensity of females to respond to the mixis chemical decreased strongly with age. The highest proportion of mictic offspring (up to 63%) was produced by females of the youngest adult age class (∼24–48 h old). Females older than 3 days were virtually unresponsive to the mixis stimulus.
Non-Newtonian behaviour in ferrofluids and magnetization relaxation
2006-09-08

The relaxation of magnetization, a well-accepted part of ferrofluid dynamics, is shown to give rise to a broad range of non-Newtonian behaviour in ferrofluids, including shear thinning or shear thickening, normal stress differences, a visco-elastic response and a varying Trouton, or elongational, viscosity.
Cranial osteology ofGuizhouichthyosaurus tangae(Reptilia: Ichthyosauria) from the Upper Triassic of China
2006-09-11

Abstract The cranial osteology of the large ichthyosaur Guizhouichthyosaurus tangae from the Wayao Member of the Falang Formation (Lower Carnian, Upper Triassic) of Guizhou, southwest China, is described, based on a well preserved skull and mandible and additional specimens. It can be diagnosed by a suite of cranial characters that include premaxilla without well-developed processus subnarialis, maxilla reaches far anteriorly and has a very long processus postnarialis, orbit of characteristic shape with concave dorsal and straight posterior and ventral margins, small prefrontal that forms only the anterior third of the dorsal orbital margin, postfrontal meets the supratemporal externally, postorbital forms a large part of the lateral margin of the temporal fenestra internally, deep triangular incisura postjugalis, jugal fails to meet quadratojugal externally, short postorbital skull segment; frontals and parietals form sharp ridges lateral to the area of the foramen parietale; parietals form a low and narrow sagittal crest; teeth thecodontously implanted, blunt, conical and without carinae. New data on the postcranial skeleton are also provided. The available evidence indicates that Guizhouichthyosaurus is an advanced member of the Merriamosauria, but more plesiomorphic than the parvipelvians. The taxonomy of the large ichthyosaurs from the Falang Formation remains largely problematic. It appears probable that only two taxa are valid, Guizhouichthyosaurus tangae and Guanlingsaurus liangae. They differ in the length of the snout, the number of the presacral vertebrae, vertebral proportions, the shape of the humerus and fibula, among other features.
The braincase ofPhantomosaurus neubigi(Sander, 1997), an unusual ichthyosaur from the Middle Triassic of Germany
2006-09-11

Abstract The structure of the braincase and the posterior portion of the palate of the type and only known specimen of Phantomosaurus neubigi (Sander, 1997) from the Upper Muschelkalk (Late Anisian) of Franconia (Southern Germany) is redescribed. P. neubigi is unique among hitherto known ichthyosaurs in numerous features of braincase morphology. These include an anteroposteriorly compressed, elongate and slender processus paroccipitalis, a clear sutural connection between the basioccipital and opisthotic, a foramen metoticum that is completely enclosed by the exoccipital and opisthotic, fusion between exoccipital and opisthotic, the retention of rudimentary postparietals -which are recorded in ichthyosaurs for the first time- and a concave occipital condyle (the latter feature is also known in a limited number of other Triassic ichthyosaurs). These characters of the Phantomosaurus braincase differ from post-Triassic ichthyosaurs, which are characterized by a strong reduction of braincase ossification, particularly with regard to the otic capsule. A short survey of current knowledge on ichthyosaur braincase anatomy as well as comparison to well-known basal amniotes and basal diapsids suggests, that the features shown by Phantomosaurus must largely be regarded as plesiomorphic and that its braincase is the most plesiomorphic ichthyosaur braincase currently known. This leads to a new view on the primitive condition of the ichthyosaur braincase that has to be considered in any further studies on ichthyosaur origins and evolution.
Changes of epidermodysplasia verruciformis in benign skin lesions: the EV acanthoma
2006-09-12

Abstract: Foci of histological changes of epidermodysplasia verruciformis (EV) were noted in five benign skin lesions. These skin lesions included an intradermal nevus, a pigmented seborrheic keratosis, an isolated papule on the forearm, a perianal lesion, and an acantholytic acanthoma. Because the changes resembled true EV so strongly despite the absence of clinical EV in these patients, we searched for EV‐human papilloma virus (HPV) types in these skin lesions. Polymerase chain reaction (PCR) analysis on the formalin‐fixed, paraffin‐embedded blocks was performed. As a positive control, we included tissue from two HIV‐positive patients with clinical EV proven by biopsy. Studies were also performed on five other archived biopsies that did not show changes of EV on multiple tissue sections. A nested PCR method detected EV‐HPV types in three of the five benign skin lesions showing EV changes as well as in the positive controls. EV changes and EV‐HPV can be found incidentally on biopsy in the absence of clinical EV; when such changes are the major histopathological finding in an isolated skin lesion, the lesion should be termed an EV acanthoma.
Three-Dimensional Cerebral Contrast-Enhanced Magnetic Resonance Venography at 3.0 Tesla
2006-09-13

High spatial resolution 3D cerebral CE-MR venography is feasible and promising. Using a 32-channel 3.0 T system combined with multichannel array coils effectively supports highly accelerated parallel imaging, enabling subsequent acquisition of both high spatial resolution CE-MR angiography and CE-MR venography after a single contrast injection without impairing the image quality. More extensive clinical studies are warranted to establish the range of applications and confirm the accuracy of this technique.
Comparison of large basis set DFT and MP2 calculations in the study of the barrier for internal rotation of 2,3,5,6‐tetrafluoroanisole
2006-09-13

Abstract The barrier for internal rotation around the OCH 3 bond in 2,3,5,6‐tetrafluoroanisole was calculated using the density functional theory (DFT) and second‐order Møller–Plesset (MP2) methods with Pople's basis sets up to 6‐311++G(3 df ,2 p ) and Jensen basis sets up to pc‐3. The results are converged only if fairly large basis sets are used (at least 6‐311++G(3 df ,2 pd ) or pc‐2). Both the DFT and MP2 potential energy curves show internal structure. Two minima and three maxima are observed on the curves, arising from the interplay between lone‐pair delocalization and changes in the hybridization around the oxygen atom, together with the attraction between the positively polarized hydrogens in the methyl group and the negatively polarized fluorine atom at the ortho position. These critical points are somehow ironed out by the addition of zero‐point and thermal corrections to the energy curves. At this level, the MP2 method can describe reasonably well the previously determined single‐well experimental rotational barrier, 2.7 ± 2.0 kcal/mol at 298 K, while all DFT methods yield a much smaller result. As observed experimentally, the OCH 3 group is perpendicular to the aryl ring in the equilibrium structure, although two very close minima with an intermediate hump at 90° are still observable. The theoretical free energy barrier of rotation at the MP2(full)/pc‐2 level is 2.0 ± 1.0 kcal/mol, in reasonable agreement with the experimental determination. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Acute activation of NHE3 by dexamethasone correlates with activation of SGK1 and requires a functional glucocorticoid receptor
2006-09-14

Glucocorticoids stimulate the intestinal absorption of Na + and water partly by regulation of the Na + /H + exchanger 3 (NHE3). Previous studies have shown both genomic and nongenomic regulation of NHE3 by glucocorticoids. Serum and glucocorticoid-inducible kinase 1 (SGK1) has been shown to be part of this cascade, where phosphorylation of NHE3 by SGK1 initiates the translocation of NHE3 to the cell surface. In the present work, we examined a series of changes in SGK1 and NHE3 induced by glucocorticoids using human colonic Caco-2 and opossum kidney cells. We found that dexamethasone rapidly stimulated SGK1 mRNAs, but a significant change in protein abundance was not detected. Instead, there was an increase in SGK1 kinase activity as early as at 2 h. An increase in NHE3 protein abundance was not detected until 12 h of dexamethasone exposure, although the transport activity was significantly stimulated at 4 h. These data demonstrate that the changes of SGK1 precede those of NHE3. Chronic regulation (24 h) of NHE3 was blocked completely by prevention of protein synthesis with cycloheximide or actinomycin D and by the glucocorticoid receptor blocker RU486. The acute effect of dexamethasone was similarly abrogated by RU486, but was insensitive to cycloheximide and actinomycin D. Similarly, the stimulation of SGK1 activity by dexamethasone was blocked by RU486 but not by actinomycin D. Together, these data show that the acute effect of glucocorticoids on NHE3 is mediated by a glucocorticoid receptor dependent mechanism that activates SGK1 in a nongenomic manner.
Self‐reported defence mechanisms as an outcome measure in psychotherapy: A study on the German version of the Defence Style Questionnaire DSQ 40
2006-09-14

The psychoanalytically informed construct of ‘defence mechanisms’ is of central importance for the understanding of the dynamics of inner conflicts and the onset of neurotic symptoms. Objective and valid assessment of ‘defence’ is difficult. There are a number of observer rating instruments but only few self‐report questionnaires. The German version of the ‘Defence Style Questionnaire ‐ DSQ 40’ () was examined with regard to its factorial and content validity, and its sensitivity to change during inpatient psychotherapy. One hundred and fifty‐five patients with mixed diagnoses were administered the DSQ 40 and the SCL‐90‐R before and after 3 months of inpatient psychotherapy. Diagnoses were mostly affective and anxiety disorders as well as eating disorders, and there was a high comorbidity of personality disorders. After deletion of some items due to insufficient pairwise item‐intercorrelation or false classification to a defence mechanism by experienced clinicians, we found three stable factors of defence (maladaptive, intermediate‐neurotic and adaptive) consistent with the previous research. After 3 months of therapy, a decrease in maladaptive mechanisms and an increase in adaptive patterns were found, while neurotic mechanisms did not change on average. Our shortened version of the DSQ 40 was shown to be a valid instrument for the assessment of defence mechanisms and change in these mechanisms after psychotherapy. Our design did not permit an assessment of whether or not the change in defence mechanisms was due to the therapeutic treatment.