julilili42/papers huggingface dataset:
Reliability of findings around healthy implants in association with oral hygiene measures: a clinical, microbiological, and immunological follow‐up in edentulous patients
2007-08-09

Abstract Objectives: To assess the performance of clinical, microbiological, and immunological diagnosis of peri‐implant health and the influence of professional hygiene measures on them. Material and methods: Twenty‐one edentulous patients with oral implants supporting a lower overdenture were followed up over 3 months beginning 1 week before their annual recall visit. Hygiene scores, probing depth, bleeding on probing (BOP), implant stability, gingival crevicular fluid (GCF) volume, sulcular interleukin‐1β (IL‐1β) and prostaglandin E2 (PGE2) concentrations, and relative concentrations of five bacterial species (polymerase chain reaction) were investigated. Measurement variation was assessed as a function of (a) intra‐ and (b) inter‐examiner reliability, (c) inter‐implant variation in each patient, (d) time, and (e) effect of hygiene measures by accuracy, repeatability, reproducibility, and visualization with the Bland and Altman Plot. Results: Measurement means and accuracy (in parentheses) were as follows: GCF volume 1.5 μl (1.5), Interleukin‐1β 8 ng/ml (26), PGE2 63 ng/ml (185), bacteria sum score 0.2 (0.7), plaque score 1 (1), BOP score 0 (1), Periotest value −4 (3), resonance frequency analysis ISQ 66 (11), and pocket probing depth 2.3 mm (0.7). No finding exhibited any statistically significant measurement variation as explained by accuracy, repeatability, or reproducibility. Bland and Altman Plots revealed insufficient agreement for replicated BOP assessments. A short post‐treatment reduction in plaque and BOP scores was visually apparent. Still, professional oral hygiene measures exerted no sustained influence on the clinical and biochemical appearance of the peri‐implant tissues. Conclusion: All findings except BOP showed statistically acceptable repeatability and moderate vulnerability to influences present ‘chairside’ in clinical practice.
Data-based modeling of analog-mixed signal systems in automotive applications with support vector machines
2007-08-09

Functional verification by simulation is an important step during the development of present microelectronic solutions for automotive applications. Its relevance is based on the capability to compare the behavior of a developed circuit with its specification. Since the transient simulation of application specific integrated circuits (ASICs) normally shows long runtimes, the behavior of time-critical components is manually modeled in order to speed up simulation. The present article describes a data-based approach for semi-automated generation of behavioral models for analog mixed-signal (A/MS) systems. The approach is based on support vector machines and a transformation dictionary for extraction of dynamic properties. The application of this method results in highly accurate pin-compatible behavioral models for A/MS systems with a significant reduction in simulation times. Additionally, the generated models can be easily integrated in description languages like VDHL-AMS, Verilog-AMS, Simulink and MAST. Another benefit of the proposed method consists in its flexibility to model systems of different physical domains. The emphasized properties will be illustrated by the modeling of two examples belonging to analog-digital and electromechanic systems respectively.
Competition of Lamellar Orientation in Thin Films of a Symmetric Poly(styrene)-b-poly(l-lactide) Diblock Copolymer in Melt State
2007-08-10

We have studied the lamellar orientation in thin films of a model diblock copolymer, symmetric poly(styrene)-b-poly(l-lactide) (PS−PLLA), in the melt state on supported silicon wafer surface. In this system, while the PLLA block prefers to wet the polymer/substrate interface, the polymer/air as well as polymer/polymer interface is neutral for both blocks due to the similar surface energies of PS and PLLA in melt state. Our results demonstrate that the interplay of the interfaces during phase separation results in a series of structures before approaching the equilibrium state. Lamellar orientation of thin films with different initial film thicknesses at different annealing stages has been investigated using atomic force microscopy (AFM), transmission electronic microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It is found that in the early stage (annealing time t < 10 min), the polymer/substrate interface dominates the structure evolution, leading to a parallel lamellar structure with holes or islands formed depending on the initial film thickness. Later on, the neutral air interface becomes important and leads to a transition of lamellar orientation from parallel to perpendicular. It is interesting to see that for films with thickness h > 2L, where L is the bulk lamellar period, the lamellar orientation transition can occur independently in different parallel lamellar domains due to the neutrality of polymer/polymer interface. This independent transition leads to a new intermediate stage; i.e., the perpendicular lamellae in two adjacent layers can be either parallel or cross to each other. Certainly, these interlaced structures are not the thermodynamic equilibrium forms; they emerge into the uniformed perpendicular structure upon further annealing.
Nuclear matter in the crust of neutron stars
2007-08-13

The properties of inhomogeneous nuclear matter are investigated considering the self-consistent Skyrme Hartree-Fock approach with inclusion of pairing correlations. For a comparison we also consider a relativistic mean field approach. The inhomogeneous infinite matter is described in terms of cubic Wigner-Seitz cells, which leads to a smooth transition to the limit of homogeneous nuclear matter. The possible existence of various structures in the so-called pasta phase is investigated within this self-consistent approach and a comparison is made to results obtained within the Thomas-Fermi approximation. Results for the proton abundances and the pairing properties are discussed for densities for which clustering phenomena are obtained.
Semiclassical expansion of quantum characteristics for many-body potential scattering problem
2007-08-13

In quantum mechanics, systems can be described in phase space in terms of the\\nWigner function and the star-product operation. Quantum characteristics, which\\nappear in the Heisenberg picture as the Weyl's symbols of operators of\\ncanonical coordinates and momenta, can be used to solve the evolution equations\\nfor symbols of other operators acting in the Hilbert space. To any fixed order\\nin the Planck's constant, many-body potential scattering problem simplifies to\\na statistical-mechanical problem of computing an ensemble of quantum\\ncharacteristics and their derivatives with respect to the initial canonical\\ncoordinates and momenta. The reduction to a system of ordinary differential\\nequations pertains rigorously at any fixed order in . We present\\nsemiclassical expansion of quantum characteristics for many-body scattering\\nproblem and provide tools for calculation of average values of time-dependent\\nphysical observables and cross sections. The method of quantum characteristics\\nadmits the consistent incorporation of specific quantum effects, such as\\nnon-locality and coherence in propagation of particles, into the semiclassical\\ntransport models. We formulate the principle of stationary action for quantum\\nHamilton's equations and give quantum-mechanical extensions of the Liouville\\ntheorem on the conservation of phase-space volume and the Poincar\\\\'e theorem on\\nthe conservation of forms. The lowest order quantum corrections to the\\nKepler periodic orbits are constructed. These corrections show the resonance\\nbehavior.\\n
hDectin-1 is involved in uptake and cross-presentation of cellular antigens
2007-08-14

Abstract Human Dectin-1 (hDectin-1) is a member of the C-type lectin–like receptor family that was shown to be the major receptor for fungal beta-glucans and to play an important role in the cellular responses mediated by these carbohydrates. In this study, we demonstrate that hDectin-1 is involved in the uptake and cross-presentation of cellular antigens. Furthermore, activation of monocyte-derived dendritic cells (MDCs) with toll-like receptor 3 (TLR3) ligand but not with TLR2 ligand or TLR7 ligand resulted in down-regulation of hDectin-1 expression and reduced phagocytosis of apoptotic tumor cells as well as presentation of pp65-derived T-cell epitopes upon engulfment of cytomegalovirus (CMV)–infected human foreskin fibroblasts.
Differential cytokine activity and morphology during wound healing in the neonatal and adult rat skin
2007-08-14

Abstract Wound‐healing mechanisms change during transition from prenatal to postnatal stage. Cytokines are known to play a key role in this process. The current study investigated the differential cytokine activity and healing morphology during healing of incisional skin wounds in rats of the ages neonatal (p0), 3 days old (p3) and adult, after six different healing times (2 hrs to 30 days). All seven tested cytokines (Transforming Growth Factor (TGF) α, TGFβ 1 , −β 2 and −β 3 , IGF 1, Platelet Derived Growth Factor A (PDGF A), basic Fibroblast Growth Factor (bFGF) exhibited higher expression in the adult wounds than at the ages p0 and p3. Expression typically peaked between 12 hrs and 3 days post‐wounding, and was not detectable any more at days 10 and 30. The neonate specimen showed more rapid re‐epithelialization, far less inflammation and scarring, and larger restitution of original tissue architecture than their adult counterparts, resembling a prenatal healing pattern. The results may encourage the use of neonatal rat skin as a wound‐healing model for further studies, instead of the more complicated prenatal animal models. Secondly, the data may recommend inhibition of PDGF A, basic FGF or TGF‐β 1 as therapeutic targets in efforts to optimize wound healing in the adult organism.
Serum components and activated Ha‐ras antagonize expression of perivenous marker genes stimulated by β‐catenin signaling in mouse hepatocytes
2007-08-14

Hepatocytes of the periportal and perivenous zones of the liver lobule show marked differences in the contents and activities of many enzymes and other proteins. Previous studies from our and other groups have pointed towards an important role of β‐catenin‐dependent signaling in the regulation of expression of genes encoding proteins with preferential perivenous localization, whereas, in contrast, signaling through Ras‐dependent pathway(s) may induce a ‘periportal’ phenotype. We have now conducted a series of experiments to further investigate this hypothesis. In transgenic mice with scattered expression of an activated Ha‐ras (Ha‐ras G12V ) mutant in liver, expression of the perivenous markers glutamine synthetase and two cytochrome P450 isoforms was completely abolished in those hepatocytes demonstrating constitutively activated extracellular signal‐regulated kinase activity, even though they were located directly adjacent to central veins. Similarly, incubation of primary hepatocytes or hepatoma cells with increasing amounts of serum caused a concentration‐dependent attenuation of expression of perivenous marker mRNAs, whereas the expression of periportal markers was increased. The inhibitory effect of high amounts of serum on the expression of perivenous markers was also observed if their expression was stimulated by activation of β‐catenin signaling, and comparable inhibitory effects were seen in cells stably transfected with a T‐cell factor/lymphoid‐enhancing factor‐driven luciferase reporter. Epidermal growth factor could partly mimic serum effects in hepatoma cells, and its effect could be blocked by an inhibitor of extracellular signal‐regulated kinase activity. These data suggest that activation of the Ras/mitogen‐activated protein kinase (extracellular signal‐regulated kinase) pathway favors periportal gene expression while simultaneously antagonizing a perivenous phenotype of hepatocytes.
Activation of superior colliculi in humans during visual exploration
2007-08-14

Our data demonstrate the involvement of the SC in a visual search task. In contrast to the results of previous studies, signal changes could not be seen to be driven by either visual stimulation or oculomotor control on their own. Further, we can exclude the influence of any nearby neural structures (e.g. pulvinar, tegmentum) or of typical artefacts at the brainstem on the observed signal changes at the SC. Corresponding to findings in non-human primates, our data support a dependency of SC activity on functions beyond oculomotor control and visual processing.
Does Matching Versus Mismatching Message Content to Attitude Functions Lead to Biased Processing? The Role of Message Ambiguity
2007-08-14

Previous research on the question of whether matching message content to the functional basis of people's attitudes may lead to biased message processing has been inconclusive. In particular, existing evidence is open to reinterpretation such that matched strong arguments led to more attitudinal agreement because they were scrutinized more effortfully than mismatched strong arguments. The present study was conducted to examine the hypothesis that matching the message to attitude functions may lead to biased processing only given an ambiguous (vs. an unambiguous strong or weak) message. High and low self-monitors were presented with a matched message (i.e., a quality appeal for low self-monitors and an image appeal for high self-monitors) or a mismatched message (opposite combinations). The message content was strong, weak, or ambiguous. As predicted, only given an ambiguous message did biased processing lead to more agreement when the appeal matched (versus mismatched) attitude functions. In contrast, a strong message led to more agreement than a weak message regardless of functional matching (unbiased processing).
Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells
2007-08-14

To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37) on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 microm ("thin" or "thick" dendrites, respectively). Three cells (4.5%) were bistratified, having thick dendrites, and the others (95.5%) were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40%) and 2 groups with inner (50-100%) stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat beta-cells, whereas one group of cells with thick dendrites includes cells that resemble cat alpha-cells.
Polychlorinated Biphenyls 105 and 118 Form Thyroid Hormone Receptor Agonists after Cytochrome P4501A1 Activation in Rat Pituitary GH3 Cells
2007-08-15

We propose that PCB 126 induces CYP1A1 through the AhR in GH3 cells, and that CYP1A1 activates PCB 105 and/or 118 to a form a compound that acts as a TR agonist. These data suggest that some tissues may be especially vulnerable to PCBs interfering directly with TH signaling due to their capacity to express CYP1A1 in response to coplanar PCBs (or other dioxin-like molecules) if sufficient mono-ortho PCBs are present.
IMRT optimization including random and systematic geometric errors based on the expectation of TCP and NTCP
2007-08-15

The purpose of this work was the development of a probabilistic planning method with biological cost functions that does not require the definition of margins. Geometrical uncertainties were integrated in tumor control probability (TCP) and normal tissue complication probability (NTCP) objective functions for inverse planning. For efficiency reasons random errors were included by blurring the dose distribution and systematic errors by shifting structures with respect to the dose. Treatment plans were made for 19 prostate patients following four inverse strategies: Conformal with homogeneous dose to the planning target volume (PTV), a simultaneous integrated boost using a second PTV, optimization using TCP and NTCP functions together with a PTV, and probabilistic TCP and NTCP optimization for the clinical target volume without PTV. The resulting plans were evaluated by independent Monte Carlo simulation of many possible treatment histories including geometrical uncertainties. The results showed that the probabilistic optimization technique reduced the rectal wall volume receiving high dose, while at the same time increasing the dose to the clinical target volume. Without sacrificing the expected local control rate, the expected rectum toxicity could be reduced by 50% relative to the boost technique. The improvement over the conformal technique was larger yet. The margin based biological technique led to toxicity in between the boost and probabilistic techniques, but its control rates were very variable and relatively low. During evaluations, the sensitivity of the local control probability to variations in biological parameters appeared similar for all four strategies. The sensitivity to variations of the geometrical error distributions was strongest for the probabilistic technique. It is concluded that probabilistic optimization based on tumor control probability and normal tissue complication probability is feasible. It results in robust prostate treatment plans with an improved balance between local control and rectum toxicity, compared to conventional techniques.
Early Treatment to Correct Class III Relations with or without Face Masks
2007-08-15

Abstract Objective: To determine what therapeutic effects can be expected in the case of early treatment of Class III relations with removable appliances with or without face masks. Materials and Methods: Records available at the university clinic of Tübingen for 41 patients who had undergone early treatment because of prognathic abnormalities were retrospectively evaluated. Lateral cephalograms taken and casts obtained at baseline and at the end of early treatment were included in the analysis. Two treatment strategies were compared. The first group included removable functional orthopedic appliances only (FOA group), while the second group was treated with removable appliances and with face masks mounted on a cemented maxillary expansion appliance (face mask group). Results: Positive changes were achieved in both groups for overjet (FOA group: +1.3 mm; face mask group: +2.2 mm) and Wits values (FOA group: +0.4 mm; face mask group: 1.7 mm). Moreover, a change in mean ANB values was achieved in the face mask group (+0.9°). The FOA group exhibited a reduction in mandibular angles. Changes in maxillary inclination with reduced inclination angles led to increases in overjet and overbite. The face mask group showed dorsal rotation of the mandible with reduced SNB values (−0.8°). Conclusion: Early treatment of prognathism is a meaningful option, as demonstrated by the dentoskeletal (and hence functional) improvements observed in the present study.
Substrate-dependent wetting layer formation during GaN growth: Impact on the morphology of the films
2007-08-15

We have compared epitaxial growth of GaN films on 6H-SiC(0001)-(3×3)R30°−Ga and on (0001)-sapphire. Predeposited Ga layers were nitrided by ion beam assisted molecular beam epitaxy. Whereas on SiC the initially deposited Ga covers the substrate surface completely, on sapphire only Ga droplets are present. The different distribution of the predeposited Ga affects the morphology of GaN significantly. Scanning electron microscopy and atomic force microscopy analysis of the grown films show that the complete wetting of the SiC substrate with Ga enhances finally the size and the flatness of GaN terraces and thus the quality of the film. X-ray photoelectron spectroscopy measurements reveal that metallic Ga resides also on top of the GaN films during the growth.
5-Hydrazino-1,3-dimethyl-4-nitro-1H-pyrazole
2007-08-15

Three distinct N—H⋯O,N interactions connect molecules of the title compound, C5H9N5O2, into a supramolecular assembly. The molecules are stacked in columns along the b axis. In this arrangement, the molecules are linked to each other by four two-center hydrogen bonds in an R42(12) ring motif. The N—H⋯O,N interactions have D⋯A distances ranging from 3.044 (2) to 3.182 (3) Å and D—H⋯A angles ranging from 138 (2) to 164 (2)° (where D and A are donor and acceptor, respectively).
Making Your Own Order: Order Effects in System- and User-Controlled Settings for Learning and Problem Solving
2007-08-16

Abstract This chapter addresses the question of how tasks should be ordered to foster learning and the transfer of knowledge. It first reviews the existing findings on simple-to-complex sequencing and sequencing according to the structural variability of tasks. Second, for the explanation of order effects, it outlines a model that supports deriving testable hypotheses for when and why instructional sequences should vary in performance. Third, it describes the results from two experiments that confirm these hypotheses. Fourth, the model of order effects is applied to user-controlled settings (i.e. those in which the students are allowed to determine the order of the problems). The role of rearranging problems is investigated by means of a questionnaire and an experiment. The chapter ends with a discussion of the instructional implications and some suggestions for future research in this area.
Faculty Opinions recommendation of Gene-specific control of inflammation by TLR-induced chromatin modifications.
2007-08-16

Toll-like receptors (TLRs) induce a multi-component inflammatory response that must be tightly regulated to avoid tissue damage. Most known regulatory mechanisms target TLR signalling pathways and thus broadly inhibit multiple aspects of the inflammatory response. Given the functional diversity of TLR-induced genes, we proposed that additional, gene-specific regulatory mechanisms exist to allow individual aspects of the TLR-induced response to be differentially regulated. Using an in vitro system of lipopolysaccharide tolerance in murine macrophages, we show that TLR-induced genes fall into two categories on the basis of their functions and regulatory requirements. We demonstrate that representatives from the two classes acquire distinct patterns of TLR-induced chromatin modifications. These gene-specific chromatin modifications are associated with transient silencing of one class of genes, which includes pro-inflammatory mediators, and priming of the second class, which includes antimicrobial effectors. These findings illustrate an adaptive response in macrophages and reveal component-specific regulation of inflammation. PMID: 17538624