julilili42/papers huggingface dataset:
A Hypothetical Mechanism of Generating Magnetically Charged Fermions by CP-symmetry Breaking
2005-10-01

Based on the assumption that electroweak bosons, leptons and quarks possess a substructure of elementary fermionic constituents, in a previous paper it was demonstrated that under CP-symmetry breaking “electric” and “magnetic” electroweak bosons coexist, where the latter transmit magnetic monopole interactions. In this paper the calculation is extended to the derivation of the effective theory for electroweak bosons and leptons. It is shown that under the influence of CP-symmetry breaking charged leptons are transmuted into dyons, the interactions of which are mediated by electric and magnetic electroweak bosons. The dynamical law of the fermionic constituents is assumed to be given by a relativistically invariant nonlinear spinor field theory with local interaction, canonical quantization, selfregularization and probability interpretation. The corresponding effective theory is derived by means of weak mapping theorems and turns out to be an extension of the Standard model for dyons where owing to CP-violation SU(2)-symmetry is simultaneously broken. A mechanism of inducing CP-symmetry violation in the low energy range is proposed
Endovascular treatment of a post-traumatic thoracic false aneurysm in an adolescent. A case report.
2005-10-01

A 17 year old healthy young man suffered a motor-vehicle accident with severe polytrauma. During the rehabilitation a slight hypertension and a blood pressure difference of 30-40 mmHg between arms and legs was recognized. Mindful of a possible aortic lesion, an angio-magnetic resonance imaging (MRI) showed a 2.7x4.2 cm thoracic false aneurysm at the descending aorta. About 1 month after initial trauma, a Talent stent was implanted. The postinterventional period was uneventful. The patient was discharged on the 5th postoperative day.
Different function of pedunculopontine GABA and glutamate receptors in nucleus accumbens dopamine, pedunculopontine glutamate and operant discriminative behavior
2005-10-01

Abstract The nucleus accumbens, as the main input structure of the ventral basal ganglia loop, is described as a limbic–motor interface. Dopamine input to nucleus accumbens modulates processing of concurrent glutamate input from limbic structures carrying motor and motivational information. There is evidence that these dopamine/glutamate interactions are fundamentally involved in response selection processes. However, the pedunculopontine tegmental nucleus (PPTg) in the brainstem is connected with limbic structures as well as dopaminergic midbrain areas, which also project to the nucleus accumbens. Furthermore, behavioral studies implicate the PPTg in complex, motivated behavior. Thus, the PPTg might be involved in motivated behavior by influencing response selection processes in the nucleus accumbens. In this study we used in vivo microdialysis in freely moving rats in order to inhibit (100, 200, 300 and 400 μ m baclofen) or stimulate [5, 12.5, 25 or 50 μ m α‐amino‐3‐hydroxy‐5‐methyl‐isoxazole‐4‐propionic acid (AMPA)] the PPTg in animals that are performing an operant discrimination task for food reward. The behavioral consequences were correlated with dopamine and glutamate levels in nucleus accumbens and PPTg, respectively. PPTg inhibition by local GABA B receptors impaired the response rate and accuracy of performance in the operant discrimination task. PPTg stimulation by local AMPA receptors exclusively impaired the response rate. Both treatments blocked the performance‐driven dopamine signal in nucleus accumbens, whereas glutamate in PPTg was enhanced after AMPA administration only. The data indicate that the PPTg functionally participates in a network of subcortical and cortical structures, which is responsible for the execution of motivated behavior and response selection processes.
Post-Randomization Under Test: Estimation of the Probit Model
2005-10-01

Summary The paper analyzes effects of randomized response with respect to some binary dependent variable on the estimation of the probit model. This approach is used in interviews when asking sensitive questions or if a respondent erroneously chooses the wrong category in an interview leading to ‘misdassification’. Alternatively, randomization can be used for statistical disclosure control and then is called ‘post randomization method’ (PRAM). We consider two variants which are termed ‘ordinary’ and ‘invariant’ PRAM the latter being of importance mainly in descriptive analysis. Maximum likelihood estimation of the corrected likelihood results in consistent estimates although variances increase considerably for ‘strong’ randomization. Moreover a finite sample bias has been observed in the simulation study, but it is much less pronounced than the bias implied from use of the ‘naive’ probit estimator when the binary dependent variable has been randomized. Effects of randomization on the probit estimates are also illustrated by an empirical study using cross-section data from the German ‘ΑΒ establishment panel’ (IAB Betriebspanel). The decision of firms to accept a collective bargaining agreement (‘Tarifvertrag’) is analyzed in a binary probit model using both original data and data masked by ordinary and invariant PRAM. Here, too, a remarkable bias is observed in case of ‘strong’ randomization.
Development of a Novel Collagen-Based Biphasic Carrier for Matrix-Assisted Transplantation of Autologous Chondrocytes
2005-10-01

Langzeitresultate und prospektiv randomisierte Studien zeigen, dass die autologe Chondrozytentransplantation (ACT) für die biologische Rekonstruktion von umschriebenen Knorpelschäden des Kniegelenks über 4 cm2 Defektgröße beim Erwachsenen die derzeit zuverlässigste Methode ist. Die konventionelle Form der ACT weist jedoch auch einige Nachteile auf. Hierzu gehören vor allem die häufig erforderliche, langstreckige Arthrotomie für die Periostaufnaht, das Risiko einer Transplantathypertrophie, die nach dem derzeitigen Kenntnisstand vom Periostlappen ausgeht, und die eingeschränkte Anwendbarkeit bei Defekten ohne erhaltenes Containment. Zur Lösung dieser Probleme wurde von unserer Arbeitsgruppe eine kollagenbasierte biphasische Matrix für die trägergekoppelte Form der ACT entwickelt. Das neue Biomaterial stabilisiert den Phänotyp der eingesäten Chondrozyten und lässt sich mithilfe spezieller Instrumente minimalinvasiv in den Defekt implantieren. Im Zuge der Trägerentwicklung wurde eine Reihe von verschiedenen Biomaterialien synthetischer und natürlicher Herkunft mit humanen Chondrozyten in vitro und in der SCID-Maus untersucht. In der vorliegenden Arbeit werden einige der wichtigsten Ergebnisse unserer Untersuchungen mit den verschiedenen Biomaterialien beschrieben. Abschließend wird eine neue Methode zur arthroskopischen Vermessung von Knorpelschäden mit dem OrthoPilot® sowie ein neues Verfahren zur Entwicklung intelligenter Biomaterialien vorgestellt.
Rootletin forms centriole-associated filaments and functions in centrosome cohesion
2005-10-03

After duplication of the centriole pair during S phase, the centrosome functions as a single microtubule-organizing center until the onset of mitosis, when the duplicated centrosomes separate for bipolar spindle formation. The mechanisms regulating centrosome cohesion and separation during the cell cycle are not well understood. In this study, we analyze the protein rootletin as a candidate centrosome linker component. As shown by immunoelectron microscopy, endogenous rootletin forms striking fibers emanating from the proximal ends of centrioles. Moreover, rootletin interacts with C-Nap1, a protein previously implicated in centrosome cohesion. Similar to C-Nap1, rootletin is phosphorylated by Nek2 kinase and is displaced from centrosomes at the onset of mitosis. Whereas the overexpression of rootletin results in the formation of extensive fibers, small interfering RNA–mediated depletion of either rootletin or C-Nap1 causes centrosome splitting, suggesting that both proteins contribute to maintaining centrosome cohesion. The ability of rootletin to form centriole-associated fibers suggests a dynamic model for centrosome cohesion based on entangling filaments rather than continuous polymeric linkers.
HPLC‐MS/MS analysis of willow bark extracts contained in pharmaceutical preparations
2005-10-05

Abstract Preparations containing willow bark extract are popular herbal remedies, but they are mostly standardised with respect to only one compound (usually salicin). RP‐HPLC using a C 18 ‐column eluted with water:methanol: tetrahydrofuran and coupled to electrospray triple‐quadrupole MS and MS/MS was used for the characterisation of dried extracts of Salix spp. and for the identification of their constituents. Comparison with reference substances led to the identification of 13 compounds (saligenin, salicylic acid, salicin, isosalicin, picein, salidroside, triandrin, salicoylsalicin, salicortin, isosalipurposide, salipurposide, naringenin‐7‐ O ‐glucoside and tremulacin). Two pharmaceutical preparations containing willow bark extract, used in clinical trials and labelled Salix daphnoides and S. purpurea × daphnoides extracts, were compared using the described method and exhibited several clear differences, the most prominent of which was the possible presence of picein in the former preparation. The described method may be utilised for the characterisation of herbal medicines in order to ensure comparability of medication in further clinical trials. Copyright © 2005 John Wiley &amp; Sons, Ltd.
Structural and morphological characterization of hemozoin produced by Schistosoma mansoni and Rhodnius prolixus
2005-10-05

Hemozoin (Hz) is a heme crystal produced upon the digestion of hemoglobin (Hb) by blood‐feeding organisms as a main mechanism of heme disposal. The structure of Hz consists of heme dimers bound by reciprocal iron–carboxylate interactions and stabilized by hydrogen bonds. We have recently described heme crystals in the blood fluke, Schistosoma mansoni, and in the kissing bug, Rhodnius prolixus . Here, we characterized the structures and morphologies of the heme crystals from those two organisms and compared them to synthetic β‐hematin (βH). Synchrotron radiation X‐ray powder diffraction showed that all heme crystals share the same unit cell and structure. The heme crystals isolated from S. mansoni and R. prolixus consisted of very regular units assembled in multicrystalline spherical structures exhibiting remarkably distinct surface morphologies compared to βH. In both organisms, Hz formation occurs inside lipid droplet‐like particles or in close association to phospholipid membranes. These results show, for the first time, the structural and morphological characterization of natural Hz samples obtained from these two blood‐feeding organisms. Moreover, Hz formation occurring in close association to a hydrophobic environment seems to be a common trend for these organisms and may be crucial to produce very regular shaped phases, allowing the formation of multicrystalline assemblies in the guts of S. mansoni and R. prolixus .
Effect of Spatial Smoothing on t-Maps: Arguments for Going Back from t-Maps to Masked Contrast Images
2005-10-05

Voxelwise statistical analysis has become popular in explorative functional brain mapping with fMRI or PET. Usually, results are presented as voxelwise levels of significance ( t-maps), and for clusters that survive correction for multiple testing the coordinates of the maximum t-value are reported. Before calculating a voxelwise statistical test, spatial smoothing is required to achieve a reasonable statistical power. Little attention is being given to the fact that smoothing has a nonlinear effect on the voxel variances and thus the local characteristics of a t-map, which becomes most evident after smoothing over different types of tissue. We investigated the related artifacts, for example, white matter peaks whose position depend on the relative variance (variance over contrast) of the surrounding regions, and suggest improving spatial precision with ‘masked contrast images’: color-codes are attributed to the voxelwise contrast, and significant clusters (e.g., detected with statistical parametric mapping, SPM) are enlarged by including contiguous pixels with a contrast above the mean contrast in the original cluster, provided they satisfy P &lt; 0.05. The potential benefit is demonstrated with simulations and data from a [ 11 C]Carfentanil PET study. We conclude that spatial smoothing may lead to critical, sometimes-counterintuitive artifacts in t-maps, especially in subcortical brain regions. If significant clusters are detected, for example, with SPM, the suggested method is one way to improve spatial precision and may give the investigator a more direct sense of the underlying data. Its simplicity and the fact that no further assumptions are needed make it a useful complement for standard methods of statistical mapping.
Septic shock caused by Streptococcus pneumoniae in a post-splenectomy patient successfully treated with recombinant human activated protein C
2005-10-06

We present a case of severe sepsis due to Streptococcus pneumoniae, serotype 22F treated with recombinant human activated protein C (drotrecogin alpha activated) (DrotAA). APACHE II score at admission was 34 with a predicted mortality of 81%. A wide range of cytokines, chemokines and receptors was measured before and after DrotAA treatment. Soon after infusion of 24 microg DrotAA per kg bodyweight and h (microg/kg/h) over a period of 96 h, cytokine levels fell markedly. The patient survived and was discharged after 6 weeks of hospitalization. In conclusion, administration of DrotAA in a case of Streptococcus pneumoniae-induced septic shock was followed by dramatic changes in serum levels of immuno-regulatory cytokines.
Cdk2 activity is dispensable for triggering replicon initiation after transient hypoxia in T24 cells
2005-10-06

We examined whether the fast release of replicon initiation after sudden O 2 recovery of hypoxically incubated mammalian cells depends on kinase activity of Cdk2. We used a system based on starved/refed T24 cells elaborated previously for such investigations [van Betteraey‐Nikoleit M, Eisele KH, Stabenow D &amp; Probst H (2003) Eur J Biochem 270 , 3880–3890]. Cells subjected to hypoxia concurrently with refeeding accumulate the G 1 DNA content within 5–6 h. In this state they are ready to perform, within 1–2 min after O 2 recovery, a burst of replicon initiations that marks the start of a synchronous S‐phase. We found that Cdk2 binds to the chromatin fraction within 4–6 h after refeeding with fresh medium, irrespective of whether the cells were incubated normoxically or hypoxically. However, inhibition of Cdk2 by olomoucine, roscovitine or the Cdk2/cyclin inhibitory peptide II had no influence on the synchronous burst of replicon initiations. Cdc6 and pRb, possible targets of Cdk2 phosphorylation, behaved differentially. Inhibition did not affect phosphorylation of Cdc6 after reoxygenation, whilst chromatin bound pRb remained hypophosphorylated beyond the initiation burst. Thus, neither Cdk2 activity, though present at the end of the hypoxic period, nor pRb phosphorylation are necessary for releasing the burst of replicon initiations upon oxygen recovery. Consequentially, Cdk2 dependent phosphorylation(s) cannot be a critical trigger of replicon initiation in response to reoxygenation after several hours of hypoxia, at least in the T24 cells studied.
Cover Picture: Microcavity‐Controlled Single‐Molecule Fluorescence (ChemPhysChem 10/2005)
2005-10-06

The cover picture shows a dipole emitter embedded in a microresonator with variable mirror separation that is excited by a tightly focused laser beam. Single dye molecules can be forced to emit into a narrow spectral window with an enhanced fluorescence rate (red curve). The efficiency of this process is determined by the interplay between the microresonator structure and the original fluorescence spectrum of the dye (grey curve). Details can be found in the Article by M. Steiner et al. on page 2190.
Endothelial survival factors and spatial completion, but not pericyte coverage of retinal capillaries, determine vessel plasticity
2005-10-07

ABSTRACT Pericyte loss and capillary regression are characteristic for incipient diabetic retinopathy. Pericyte recruitment is involved in vessel maturation, and ligand‐receptor systems contributing to pericyte recruitment are survival factors for endothelial cells in pericyte‐free in vitro systems. We studied pericyte recruitment in relation to the susceptibility toward hyperoxia‐induced vascular remodeling using the pericyte reporter X‐LacZ mouse and the mouse model of retinopathy of prematurity (ROP). Pericytes were found in close proximity to vessels, both during formation of the superficial and the deep capillary layers. When exposure of mice to the ROP was delayed by 24 h, i.e., after the deep retinal layer had formed [at postnatal (p) day 8], preretinal neovascularizations were substantially diminished at p18. Mice with a delayed ROP exposure had 50% reduced avascular zones. Formation of the deep capillary layers at p8 was associated with a combined up‐regulation of angiopoietin‐1 and PDGF‐B, while VEGF was almost unchanged during the transition from a susceptible to a resistant capillary network. Inhibition of Tie‐2 function either by soluble Tie‐2 or by a sulindac analog, an inhibitor of Tie‐2 phosphorylation, resensitized retinal vessels to neovascularizations due to a reduction of the deep capillary network. Inhibition of Tie‐2 function had no effect on pericyte recruitment. Our data indicate that the final maturation of the retinal vasculature and its resistance to regressive signals such as hyperoxia depend on the completion of the multilayer structure, in particular the deep capillary layers, and are independent of the coverage by pericytes.
Solid-state optical properties of linear polyconjugated molecules: π-stack contra herringbone
2005-10-08

The intermolecular arrangement in the solid state and the consequences on the optical and photophysical properties are studied on different derivatives of oligophenylenevinylenes by UV/VIS absorption and angular-resolved polarized fluorescence spectroscopy. Unsubstituted distyrylbenzene (DSB) organizes in a herringbone manner, with the long axes of the molecules oriented in parallel, but the short axes almost perpendicular to each other. Fluorinated distyrylbenzene (F12DSB) as well as the DSB:F12DSB cocrystals prefer cofacial π-stacking in the solid state. For all structures, the consequence of the parallel alignment of the transition moments is a strongly blueshifted H-type absorption spectrum and a low radiative rate constant kF. Significant differences are observed for the emission spectra: the perpendicular arrangement of the short axes in DSB crystals leads to only very weak intermolecular vibronic coupling. Hence the emission spectrum is well structured, very similar to the one in solution. For F12DSB and DSB:F12DSB, the cofacial arrangement of the adjacent molecules enables strong intermolecular vibronic coupling of adjacent molecules. Thus, an unstructured and strongly redshifted excimerlike emission spectrum is observed. The differences in the electronic nature of the excited states are highlighted by quantum-chemical calculations, revealing the contribution of interchain excitations to the electronic transitions.
Determining the apical terminus of root‐end resected teeth using three modern apex locators: a comparative ex vivo study
2005-10-10

Abstract Aim To assess ex vivo the accuracy of various electronic apex locators in locating the apical terminus of root‐end resected teeth. Methodology Ninety extracted human posterior teeth (182 root canals) were prepared to a minimum size of 40 and filled with gutta‐percha and sealer. After resection of the apical 3 mm of the root, the root canal filling was removed using HERO rotary instruments. The size of the root canal at the apical terminus after removal of the filling ranged from size 50 to 90. The root canal length to the apical terminus was determined using 3 apex locators (Root ZX, Raypex ® 4 and Apex Pointer). A new mounting model that utilized a micrometer was used to perform the measurements and to visually determine the actual position of the apical terminus. The frequency of locating the apical terminus and the corresponding 95% confidence interval (CI) were calculated. Additionally, the coefficient of repeatability of each apex locator and the limits of inter‐operator agreement were determined. Results All apex locators showed an acceptable repeatability (0.02–0.03 mm coefficient of repeatability) and narrow limits of inter‐operator agreement (+0.07 and −0.07 mm). The accuracy of determining the apical terminus within 1 mm in the root canal was as follows: Root ZX 90% (164/182 root‐canals) [95%CI: 86–94%], Raypex ® 4 74% (135/182 root‐canals) [95%CI: 68–80%], and Apex Pointer 71% (129/182 root canals) [95%CI: 65–77%]. No over‐instrumentation resulted when the Root ZX device was used. In contrast, using the Raypex ® 4 or the Apex Pointer device resulted in over‐instrumentation in 8 of 182 root canals (4%). Conclusions Under the conditions of this study all three apex locators were able to detect the apical terminus of root‐end resected teeth with an acceptable range. The Root ZX device was the most accurate without over‐instrumentation of the root canals.
Immune stimulatory effects of CD70 override CD70‐mediated immune cell apoptosis in rodent glioma models and confer long‐lasting antiglioma immunity in vivo
2005-10-10

Abstract CD70 (CD27 ligand) promotes the expansion of primed lymphocytes by enhancing cell survival. Surprisingly, we previously observed that CD70 aberrantly expressed on human glioma cells promoted immune cell apoptosis and inhibited alloreactive lysis. Here we report that ectopic expression of CD70 in mouse glioma cells enhances apoptosis of T, B and NK cells in coculture, but nevertheless promotes glioma cell lysis by NK cells in vitro . In nude mice, CD70 expression in SMA‐560 gliomas delays the glioma growth upon subcutaneous (s.c.) or intracerebral (i.c.) inoculation, suggesting a role for CD70/CD27‐dependent NK cell activity in tumor surveillance. In syngeneic immunocompetent VM/Dk mice, CD70 allows the rejection of s.c. and i.c. implanted SMA‐560 tumors. The tumorigenicity of CD70‐expressing glioma cells is abrogated when TGF‐β signaling is blocked. Moreover, mice surviving the s.c. CD70 glioma challenge subsequently also reject wild‐type glioma cells administered i.c. Similarly, CD70‐expressing GL‐261 gliomas are rejected in syngeneic C57BL/6 mice, while glioma growth is restored in C57BL/6 CD27 −/− mice, suggesting that the CD70/CD27 interaction recruits a tumor‐specific T‐cell repertoire and induces tumor‐specific memory. Altogether, these observations indicate that the net effect of aberrant CD70 expression in gliomas is immune stimulatory rather than immune paralytic and encourage its application in tumor immunotherapy. © 2005 Wiley‐Liss, Inc.