julilili42/papers huggingface dataset:
Density matrix-based variational quantum Monte Carlo providing an asymptotically linear scaling behavior for the local energy
2007-04-11

We present a reformulation of the variational quantum Monte Carlo (VQMC) method using the -particle density matrix ( -PDM VQMC), which allows us to reduce the conventional cubic scaling behavior to linear for the calculation of the local energy with the number of electrons for systems with a nonvanishing highest occupied molecular orbital--lowest unoccupied molecular orbital gap. The ``perturbation'' of the electron distribution, caused by the truncation of the self-consistent-field (SCF) one-electron density matrix, is compensated by the use of the McWeeny purification transformation in the presented scheme. The performance and accuracy of the presented method are illustrated through exemplary calculations.
Synthesis of 5‐Substituted 1,3‐Dimethylpyrazolo[4,3‐e][1,2,4]triazines.
2007-04-11

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Malignant Glioma Cells Counteract Antitumor Immune Responses through Expression of Lectin-Like Transcript-1
2007-04-15

Abstract Glioblastoma, one of the most lethal tumors, is paradigmatic for tumor-associated immunosuppression. Lectin-like transcript-1 (LLT1) is a newly identified ligand for the inhibitory natural killer (NK) cell receptor CD161. Here, we report that glioma cells express LLT1 mRNA and protein in vitro and in vivo, whereas expression levels in normal brain are low. LLT1 expression in human gliomas increases with the WHO grade of malignancy. We further show that transforming growth factor-β (TGF-β) up-regulates the expression of LLT1 in glioma cells. Small interfering RNA (siRNA)–mediated down-regulation of LLT1 in LNT-229 and LN-428 cells promotes their lysis by NK cells. Thus, LLT1 acts as a mediator of immune escape and contributes to the immunosuppressive properties of glioma cells. [Cancer Res 2007;67(8):3540–4]
Timing simulation of interconnected AUTOSAR software-components
2007-04-16

AUTOSAR is a recent specification initiative which focuses on a model-driven architecture like methodology for automotive applications. However, needed engineering steps, or how-to-come from a logical to a technical architecture respectively implementation, are not well supported by tools, yet. In contrast, SystemC offers a comprehensive way to simulate, analyze, and verify software. Furthermore, it is even able to take the timing behavior of underlying hardware and communication paths into account. Already at a first glance, there are many similarities with respect to the modeling structure between the both concepts. Therefore, this paper discusses approaches on how to use SystemC during the design process of AUTOSAR-conform systems.
A Late Miocene climate model simulation with ECHAM4/ML and its quantitative validation with terrestrial proxy data
2007-04-17

For the Tortonian (Late Miocene, 11 to 7 Ma), we present a model simulation using the atmospheric general circulation model (AGCM) ECHAM4 coupled to a mixed-layer (ML) ocean model. The Tortonian simulation with ECHAM4/ML includes an adjusted weaker than present ocean heat transport, a generally lower palaeorography and an appropriate palaeovegetation. We analyse the climatic differences between the Tortonian run and the present-day control experiment, and we validate our Tortonian model results for the mean annual temperature and the annual precipitation with quantitative terrestrial proxy data. Globally, the Tortonian run is slightly warmer (+ 0.6 °C) and the global precipitation indicates more humid conditions (+ 27 mm/a) than the PD control run. Particularly the northern high latitudes are warmer (+ 3.5 °C) in the Tortonian simulation which leads to a weaker meridional temperature gradient than today as well as to a reduction of polar sea ice. We attribute the polar warming to the lowering of the Greenland elevation (+ 20 °C) in the Miocene and to the effects of the palaeovegetation. The reduced altitude of the Tibetan Plateau causes a warming (+ 20 °C) as compared to today and leads to a weaker Asian monsoon in the Tortonian run. For Europe, the mean annual temperature is almost unaffected as compared to today because a cooling effect of the weak palaeocean heat transport is compensated by the palaeovegetation. When validating our model results, we find that the Tortonian run is largely consistent with quantitative proxy data. However, the high latitudes tend to be generally too cool in the palaeoclimate simulation and the equator-to-pole temperature gradient is too steep as compared to proxy data. For Europe the comparison with proxy data indicates that the Tortonian simulation underestimates the mean annual temperatures, but precipitation patterns are quite consistent between model results and proxy data. Overall, the Tortonian run is quite realistic and hence the model simulation contributes to a better understanding of the relevant climate processes in the Miocene. However, the discrepancies to proxy data demonstrate that we still do not sufficiently understand the Late Miocene climate.
EVOLUTION IN IMPERFECT COMMITMENT BARGAINING—STRATEGIC VERSUS IGNORANT TYPES
2007-04-17

ABSTRACT To commit in bargaining is crucial: in the ultimatum game with its one‐sided commitment power the ‘proposer’ (almost) receives the whole pie while the ‘responder’ is left with (almost) nothing. When bargaining parties commit simultaneously the symmetric Nash ( Econometrica , 1950, vol. 18, pp. 155–162) bargaining solution predicts equal shares. Continuously connecting these two games yields a one‐parameter family of games ( Fischer et al . , Experimental Economics , 2006, vol. 9, pp. 17–33) for which we distinguish two behavioral dispositions, namely (1) neglecting commitment power and (2) reacting to it strategically. Their pay‐off implications define the evolutionary set‐up for which we derive the evolutionarily stable behavioral disposition. Our analysis sheds light on the hypothesis that in experiments participants neglect strategic aspects such as commitment power.
3-(4-Fluorophenyl)-1-methyl-4-(4-pyridyl)quinolin-2(1H)-one
2007-04-18

The title compound, C21H15FN2O, was synthesized in the course of our studies of p38 mitogen-activated protein kinase inhibitors. It has been investigated by 1H and 13C NMR spectroscopy and was proven by X-ray crystallographic analysis to be the N-methyl rather than the O-methyl isomer. In the crystal structure, a three-dimensional network is formed consisting of quinolinone aromatic stacking interactions and weak C—H⋯O and C—H⋯N hydrogen bonds.
Patterns and prevalence of antidepressant drug use in the German state of Baden‐Wuerttemberg: a prescription‐based analysis
2007-04-19

Abstract Purpose Population‐based data about patterns and prevalence of antidepressant drug use is limited in Europe and presently unavailable for Germany. Therefore, we have identified patterns and prevalence of antidepressant use among outpatients on a population‐based scale in the German state of Baden‐Wuerttemberg. Methods We conducted a historical cohort study using a computerised prescription database referring to all members of the major German public health insurance company AOK. We assessed the prevalence of antidepressant drug use over a 3‐year period, calculated the number of prescription items purchased per patient and compared first‐line and second‐line treatments. Results The 1‐year prevalence of antidepressant drug use among more than 4 000 000 health insurance members was 7.4% (male: 4.3%; female: 10.2%). Importantly, almost 40% of the patients received only a single prescription item from 2000 to 2002. Though the use of serotonin‐reuptake inhibitors (SSRIs) markedly increased by about 65% within the study period, these are primarily used as second‐line drugs and still much less frequently than St. John's wort or tricyclic antidepressants such as amitryptiline or doxepin. Conclusions The prevalence of antidepressant drug use is higher than previously reported for other European countries. The preferred use of St. John's wort and tricyclics over SSRIs and other modern‐type antidepressants in Germany is quite unique in Europe and different from the US. The identified drug use pattern leaves a major room for improvement in view of the numerous single prescription items purchased. Copyright © 2007 John Wiley &amp; Sons, Ltd.
Autopodial skeleton evolution in side‐necked turtles (Pleurodira)
2007-04-19

Abstract Carpal and tarsal anatomy was documented based on the observation of dry skeletons of adult specimens representing 25 species in 15 genera and on data taken from the literature. In addition, histological sections and cleared and double‐stained autopodia of recently hatched and juvenile specimens representing seven chelid and pelomedusoid species were studied. There is much more morphological diversity in the manus than in the pes. Variation in autopodial skeletons includes: the astragalus and calcaneum are either separated or fused; fusion of distal carpals 3–4−5 or just 4–5; number of centralia in the carpus; and presence/absence of a pisiform and of an accessory radial element. The widespread and probably basal phalangeal formula for Pleurodira is 2.3.3.3.3. Deviations are Pelomedusa subrufa , exhibiting a reduction to 2.2.2.2.2, Pelusios spp. with one phalanx less in digit I and for one species in digit V as well, and Acanthochelys pallidipectoris with an additional phalanx in the fourth finger. Six discrete characters itemizing some of the morphological variation observed were plotted on a composite pleurodire phylogeny, revealing not only homoplastic patterns but also the utility of some characters in supporting the monophyly of several clades. The pisiform is the last carpal element to ossify in Chelus fimbriatus. We hypothesize that the so‐called fifth hooked metatarsal represents the fusion of distal tarsal 5 with metatarsal V. The accessory radial element that was occasionally present in the turtles examined may represent an atavism of the otherwise lost radiale of turtles.
Dose Performance of a 64-Channel Dual-Source CT Scanner1
2007-04-20

For electrocardiographically gated coronary CT angiography, image noise equivalent to that of multi-detector row CT can be achieved with dual-source CT at doses comparable to or up to a factor of two lower than the doses at multi-detector row CT, depending on heart rate of the patient.
Galenics of dermal products – vehicles, properties and drug release
2007-04-20

Summary The efficiency, tolerability, and applicability of topical agents are directly related to employed vehicles. Thus to achieve optimum topical therapy, a solid knowledge of the vehicles, their composition, and their physical and dermato‐pharmacological actions are important. Common vehicles are complex mixtures consisting of diverse ingredients belonging to six major groups, i. e. hydrophilic and lipophilic bases, emulsifiers, gel‐forming agents, preservatives, and antioxidants.This makes it possible to optimize both the cosmetic features and to adjust a vehicle to the properties of an incorporated drug and site of application. On the other hand it makes it difficult to make a proper choice between several alternatives or to use it in individual prescriptions. In order to simplify the selection of a formulation, it is useful to categorize them systemically into several groups, such as ointments, creams, gels, emulsions, and suspensions. Within these groups some general rules can be derived for the selection of a vehicle with respect to skin conditions and the application site. When active substances are incorporated into a base the dermato‐biopharmaceutical properties of the whole system (drug + vehicle) also have to be considered. If for a given vehicle drug transport into the skin does not suffice, several methods are described to facilitate its penetration, such as by hydrating the skin or by adding chemical penetration enhancers.
Synthesis and Structure of Europium Aluminium Garnet (EAG)
2007-04-23

Abstract Europium aluminium garnet (Eu 3 Al 5 O 12 , EAG) was synthesized by an aqueous sol‐gel process and subsequent thermal annealing at 800 – 850 °C. Eu 3 Al 5 O 12 crystallizes cubic ( and its crystal structure was refined from X‐ray powder data. The refined oxygen position in the structure of EAG yields four shorter and four longer distances between europium and the eight surrounding oxygen atoms, forming a distorted dodecahedron. Pure Eu 3 Al 5 O 12 can be treated at temperatures around 1000 °C before it converts into perovskite‐like EAP near 1300 °C.
The maize (Zea mays L.) RTCS gene encodes a LOB domain protein that is a key regulator of embryonic seminal and post‐embryonic shoot‐borne root initiation
2007-04-24

Summary Maize has a complex root system composed of different root types formed during different stages of development. The rtcs ( rootless concerning crown and seminal roots ) mutant is impaired in the initiation of the embryonic seminal roots and the post‐embryonic shoot‐borne root system. The primary root of the mutant shows a reduced gravitropic response, while its elongation, lateral root density and reaction to exogenously applied auxin is not affected. We report here the map‐based cloning of the RTCS gene which encodes a 25.5 kDa LOB domain protein located on chromosome 1S. The RTCS gene has been duplicated during evolution. The RTCS‐LIKE ( RTCL ) gene displays 72% sequence identity on the protein level. Both genes are preferentially expressed in roots. Expression of RTCS in coleoptilar nodes is confined to emerging shoot‐borne root primordia. Sequence analyses of the RTCS and RTCL upstream genomic regions identified auxin response elements. Reverse transcriptase‐PCR revealed that both genes are auxin induced. Microsynteny analyses between maize and rice genomes revealed co‐linearity of 14 genes in the RTCS region. We conclude from our data that RTCS and RTCL are auxin‐responsive genes involved in the early events that lead to the initiation and maintenance of seminal and shoot‐borne root primordia formation.
TREM-1 ligand expression on platelets enhances neutrophil activation
2007-04-24

Abstract The triggering receptor expressed on myeloid cells 1 (TREM-1) plays an important role in the innate immune response related to severe infections and sepsis. Modulation of TREM-1–associated activation improves the outcome in rodent models for pneumonia and sepsis. However, the identity and occurrence of the natural TREM-1 ligands are so far unknown, impairing the further understanding of the biology of this receptor. Here, we report the presence of a ligand for TREM-1 on human platelets. Using a recombinant TREM-1 fusion protein, we demonstrate specific binding of TREM-1 to platelets. TREM-1–specific signals are required for the platelet-induced augmentation of polymorphonuclear leukocyte (PMN) effector functions (provoked by LPS). However, TREM-1 interaction with its ligand is not required for platelet/PMN complex formation, which is dependent on integrins and selectins. Taken together, the results indicate that the TREM-1 ligand is expressed by platelets, and the TREM-1/ligand interaction contributes to the amplification of LPS-induced PMN activation. Our results shed new light on our understanding of TREM-1 and its role in the innate inflammatory response in infections and might contribute to the development of future concepts to treat sepsis.
Novel ultrahigh resolution data acquisition and image reconstruction for multi‐detector row CT
2007-04-24

We present and evaluate a special ultrahigh resolution mode providing considerably enhanced spatial resolution both in the scan plane and in the ‐axis direction for a routine medical multi‐detector row computed tomography (CT) system. Data acquisition is performed by using a flying focal spot both in the scan plane and in the ‐axis direction in combination with tantalum grids that are inserted in front of the multi‐row detector to reduce the aperture of the detector elements both in‐plane and in the ‐axis direction. The dose utilization of the system for standard applications is not affected, since the grids are moved into place only when needed and are removed for standard scanning. By means of this technique, image slices with a nominal section width of (measured full width at half maximum= ) can be reconstructed in spiral mode on a CT system with a detector configuration of . The measured 2% value of the in‐plane modulation transfer function (MTF) is , the measured 2% value of the longitudinal ( axis) MTF is . In a resolution phantom with metal line pair test patterns, spatial resolution of can be demonstrated both in the scan plane and along the axis. This corresponds to an object size of that can be resolved. The new mode is intended for ultrahigh resolution bone imaging, in particular for wrists, joints, and inner ear studies, where a higher level of image noise due to the reduced aperture is an acceptable trade‐off for the clinical benefit brought about by the improved spatial resolution.
Large-scale prediction of the parity distribution in the nuclear level density and application to astrophysical reaction rates
2007-04-24

A generalized method to calculate the excitation-energy dependent parity ratio in the nuclear level density is presented, using the assumption of Poisson distributed independent quasi particles combined with BCS occupation numbers. It is found that it is crucial to employ a sufficiently large model space to allow excitations both from low-lying shells and to higher shells beyond a single major shell. Parity ratios are only found to equilibrate above at least 5-10 MeV of excitation energy. Furthermore, an overshooting effect close to major shells is found where the parity opposite to the ground state parity may dominate across a range of several MeV before the parity ratio finally equilibrates. The method is suited for large-scale calculations as needed, for example, in astrophysical applications. Parity distributions were computed for all nuclei from the proton dripline to the neutron dripline and from Ne up to Bi. These results were then used to recalculate astrophysical reaction rates in a Hauser-Feshbach statistical model. Although certain transitions can be considerably enhanced or suppressed, the impact on astrophysically relevant reactions remains limited, mainly due to the thermal population of target states in stellar reaction rates.
Reovirus Binding Determinants in Junctional Adhesion Molecule-A
2007-04-24

Junctional adhesion molecule-A (JAM-A) serves as a serotype-independent receptor for mammalian orthoreoviruses (reoviruses). The membrane-distal immunoglobulin-like D1 domain of JAM-A is required for homodimerization and binding to reovirus attachment protein sigma1. We employed a structure-guided mutational analysis of the JAM-A dimer interface to identify determinants of reovirus binding. We purified mutant JAM-A ectodomains for solution-phase and surface plasmon resonance binding studies and expressed mutant forms of full-length JAM-A in Chinese hamster ovary cells to assess reovirus binding and infectivity. Mutation of residues in the JAM-A dimer interface that participate in salt-bridge or hydrogen-bond interactions with apposing JAM-A monomers abolishes the capacity of JAM-A to form dimers. JAM-A mutants incapable of dimer formation form complexes with the sigma1 head that are indistinguishable from wild-type JAM-A-sigma1 head complexes, indicating that sigma1 binds to JAM-A monomers. Residues Glu(61) and Lys(63) of beta-strand C and Leu(72) of beta-strand C' in the dimer interface are required for efficient JAM-A engagement of strain type 3 Dearing sigma1. Mutation of neighboring residues alters the kinetics of the sigma1-JAM-A binding interaction. Prototype reovirus strains type 1 Lang and type 2 Jones share similar, although not identical, binding requirements with type 3 Dearing. These results indicate that reovirus engages JAM-A monomers via residues found mainly on beta-strands C and C' of the dimer interface and raise the possibility that the distinct disease phenotypes produced in mice following infection with different strains of reovirus are in part attributable to differences in contacts with JAM-A.
Evidence for Deuterium Astration in the Planetary Nebula Sh 2-216?
2007-04-24

We present FUSE observations of the line of sight to WD0439+466 (LS V +46 21), the central star of the old planetary nebula Sh2-216. The FUSE data shows absorption by many interstellar and stellar lines, in particular D I, H2 (J = 0 - 9), HD (J = 0 - 1), and CO. Many other stellar and ISM lines are detected in the STIS E140M HST spectra of this sightline, which we use to determine N(HI). We derive, for the neutral gas, D/H=(0.76 +0.12 -0.11)E-5, O/H = (0.89 +0.15 -0.11)E-4 and N/H = (3.24 +0.61-0.55)E-5. We argue that most of the gas along this sightline is associated with the planetary nebula. The low D/H ratio is likely the result of this gas being processed through the star (astrated) but not mixed with the ISM. This would be the first time that the D/H ratio has been measured in predominantly astrated gas. The O/H and N/H ratios derived here are lower than typical values measured in other planetary nebulae likely due to unaccounted for ionization corrections.
OLFACTORY GROOVE MENINGIOMAS
2007-04-25

Olfactory groove meningiomas were removed mainly through two different surgical approaches. Even in large tumors, high rates of total tumor resection could also be achieved with low recurrence rates using the simple and minimally invasive frontolateral approach. In recent years, we have preferred to use the frontolateral approach, which provides quick access to the tumor with less brain exposure while still enabling total tumor removal with a low morbidity rate and no mortality.
The Rho-Kinase Inhibitor H-1152P Suppresses the Wound-Healing Activities of Human Tenon’s Capsule Fibroblasts In Vitro
2007-04-25

These findings imply a role for Rho-kinase in the wound-healing activities of human Tenon's capsule fibroblasts and show the potential of H-1152P as a safe and specific means to suppress these events.
Effects of deletions of mbtH-like genes on clorobiocin biosynthesis in Streptomyces coelicolor
2007-04-26

In the biosynthetic gene cluster of the aminocoumarin antibiotic clorobiocin, the small ORF cloY encodes a 71 aa protein which shows significant sequence similarity to mbtH from the mycobactin biosynthetic gene cluster of Mycobacterium tuberculosis. mbtH-like genes are frequently found in the biosynthetic gene clusters of peptide antibiotics and siderophores, but their function has remained enigmatic. In a recent publication it has been suggested that these genes may have no function for secondary metabolite biosynthesis. An in-frame deletion of cloY in the clorobiocin cluster has now been carried out. When the modified cluster was expressed in the heterologous host Streptomyces coelicolor M512, clorobiocin was still formed. However, when the two further mbtH-like genes from elsewhere in the host genome were inactivated as well, clorobiocin formation was reduced dramatically. Complementation with cloY or with any of three other mbtH-like genes restored clorobiocin formation. This is the first report proving the requirement of an mbtH-like gene for secondary metabolite formation, and the first proof that different mbtH-like genes can functionally replace each other. Feeding of an mbtH-defective triple mutant strain with an intact 3-amino-4,7-dihydroxy-coumarin moiety restored antibiotic production, showing that cloY is specifically required for the formation of this moiety of the clorobiocin molecule.