julilili42/papers huggingface dataset:
Element storage in spores of Gigaspora margarita Becker & Hall measured by electron energy loss spectroscopy (EELS)
2004-09-01

The storage structures of spores of Gigaspora margarita Becker &amp; Hall, an arbuscular mycorrhizal fungus, were analyzed by a transmission electronic microscope (TEM) and electron energy loss spectroscopy (EELS). The spores were hydrated, cryofixed using high pressure freezing, submitted to freeze substitution, embedded and prepared for TEM observations. The cryotechniques revealed that the storage structures in the spores are composed of lipids, electron dense granules (EDG), protein bodies and glycogen particles. The EELS detected the presence of nitrogen (N) and carbon (C) in these storage structures and in Bacteria-like organisms (BLO). Some amount of P was detected in the vacuoles and in BLO. The TEM and EELS techniques indicate the presence of storage structures in the fungal spore, and some essential elements (N, P and C) in these structures.
Ossifying Fibroma of the Skull: Interactive Image-Guided Minimally Invasive Localization and Resection
2004-09-01

Ossifying fibroma is a benign fibro-osseous tumor commonly affecting the craniofacial bones. It is considered to be a locally aggressive and quickly expansible bone lesion. Because of its aggressive nature and high recurrence rate, early detection and complete surgical removal are essential. Usually, these lesions are excised extensively by craniectomy, and bone loss is reconstructed by cranioplasty using acrylic resin or titanium implants. Alternatively, in the management of skull-ossifying fibroma, an image-guided technique using surgical navigation may provide precise information about localization, enabling complete removal, thereby operating with minimal exposure and within narrow resection borders and avoiding significant bone deformity. A 39-year-old male patient with a history of renal cell carcinoma was admitted to our hospital because a radionuclide scintigraphic bone scan revealed increased uptake in a small area located at the left lateral skull bone. The high-resolution computed tomography scan showed that the lesion was located inside the diploe, destroying the inner table of the calvarium. The patient underwent minimally invasive bone lesion removal using an interactive image-guided approach. Complete resection of the neoplastic lesion was achieved. The histopathological examination revealed an ossifying fibroma. The postoperative course was uneventful, and the patient was discharged 3 days after intervention. To date, there has been no evidence of local recurrence. Interactive multimodal planning and intraoperative image guidance offer an interesting approach for biopsy and minimally invasive removal of small ossifying fibroma lesions of the skull, especially in less accessible locations.
A review of the weevil fauna (Coleoptera, Curculionoidea) of Araucaria angustifolia (Bert.) O. Kuntze (Araucariaceae) in South Brazil
2004-09-01

The beetle superfamily Curculionoidea includes 43 species associated with Araucaria angustifolia trees in South Brazil. These weevil species belong to the families Nemonychidae (Brarus Kuschel, 1997, Rhynchitoplesius Voss, 1952), Brentidae (Taphroderes Schönherr, 1826) and Curculionidae, the latter including the subfamilies Curculioninae (Heilipodus Kuschel, 1955, Spermologus Schönherr, 1843), Cossoninae (Araucarius Kuschel, 1966, Eurycorynophorus Voss, 1964), Scolytinae (Ambrosiodmus Hopkins, 1915, Araptus Eichhoff, 1871, Cnesinus LeConte, 1868, Corthylus Erichson, 1836, Cryptocarenus Eggers, 1936, Hypothenemus Westwood, 1834, Monarthrum Kirsch, 1866, Pagiocerus Eichhoff, 1868, Phloeotribus Latreille, 1896, Pityophthorus Eichhoff, 1864, Xylechinosomus Schedl, 1963, Xyleborus Eichhoff, 1864, Xyleborinus Reitter, 1913) and Platypodinae (Cenocephalus Chapuis, 1865, Platypus Herbst, 1893, Tesserocerus Saunders, 1836). A checklist of all species including remarks on their life histories and taxonomic notes are presented. In addition, a key for the identification of adult Curculionoidea associated with Araucaria angustifolia to genus or species level is provided.
On the Restricted and Combined Use of Rūdenberg’s Approximations in Crystal Orbital Theories of Hartree-Fock Type
2004-09-01

The analysis based on Rüdenberg’s well-known letter of 1951, which has been outlined for molecules in a preceding contribution, has now been transfered to translational periodic systems in one, two, or three dimensions. Entitled “On the Three- and Four-Center Integrals in Molecular Quantum Mechanics”, this letter explicitly presents two approximations only for four-center repulsion integrals. When applied to some types of three-center repulsion integrals, however, these two recipes still imply considerable oversimplifications. Using both one-electron and two-electron routes of Rüdenberg’s expansion, such shortcomings can be avoided strictly. Starting from a simple “Unrestricted and Combined” (U&amp;C) approximation scheme introduced elsewhere, an improved “Restricted and Combined” (R&amp;C) approximation picture for Fock-matrix elements now will be outlined, which does not tolerate any unnecessary oversimplifications. Although the simplicity of the U&amp;C scheme is lost in this case, R&amp;C-approximated Fock-matrix elements still can be constructed from one- and twocenter integrals alone in an effective way. Moreover, due to their dependence on a single geometric parameter, all types of two-center integrals can be calculated in advance for about one hundred fixed interatomic distances at the desired level of sophistication, and stored once and for all. A cubic spline algorithm may be taken to interpolate the actual integral value from each precomputed list.
High‐performance liquid chromatography–coordination ion spray–mass spectrometry (HPLC‐CIS/MS): a new tool for the analysis of non‐polar compound classes in plant extracts using the example of Piper methysticum forst
2004-09-01

Abstract An efficient method to characterise complex plant extracts is described using the example of Piper methysticum Forst. (kava; Piperaceae). The method is based on the on‐line coupling of high‐performance liquid chromatography to a new detection technique: coordination ion spray–mass spectrometry (CIS/MS). CIS/MS is a universal, novel ionisation technique improving selectivity as well as sensitivity. Charged complexes were formed through addition of central complexing ions such as sodium, silver and cobalt. The advantages of CIS/MS detection compared with the electrospray ionisation detection are discussed. The experimental set‐up and the application of this simple and robust technique is described to show the its various fields of application in the analysis of plant extracts. Copyright © 2004 John Wiley &amp; Sons, Ltd.
A patient with Marfan's syndrome and neurofibromatosis type 1 with polyneuropathy
2004-09-01

Both Marfan's syndrome and neurofibromatosis type 1 are hereditary, autosomal dominant conditions. Here, we report the rare case of a patient fulfilling the clinical criteria for both diseases. In the absence of a family history of either of the two conditions, two independent de novo mutations are the most likely cause.
Direct Conversion of an ortho-Allylphenol into a Chlorosulfonyl-3-methyl-1,2-benzoxathiin 2,2-Dioxide
2004-09-01

A one-pot synthesis of methyl 6-chlorosulfonyl-3-methyl-1,2-benzoxathiin-8-carboxylate 2,2- dioxide (9), characterized as its 6-(4-methylpiperazin-1-yl)sulfonyl derivative 10, is achieved via direct reaction of methyl 3-allylsalicylate (1) with chlorosulfonic acid at −7°C. The latter reagent converts methyl 2-methyl-2,3-dihydrobenzofuran-7-carboxylate (3) into the respective 5-chlorosulfonyl derivative 7 (identified as its 5-(4-methylpiperazin-1-yl)sulfonyl derivative 8), while contrary to literature reports, the aromatic δ -sultones 9, 10 (anticipated to be produced from 3) were not detected.
Lumbar Spine Fracture in a 34,100-year-old Skeleton: The Oldest Known Prehistoric Spine Fracture
2004-09-01

WE EXAMINED SPECIAL pathological changes of the lumbar spine from skeleton remains referred to as "Stetten 1," one of the earliest specimens of modern humans dating from the Early Stone Age (Upper Paleolithic). The skeleton was discovered during archaeological excavations under Riek in 1931 in the Vogelherd Cave near Stetten, close to the Lone Valley of southwestern Germany. The archaeological context is the so-called Aurignacian period (40,000-30,000 yr ago), representing the earliest cultural step of modern humans in Europe. Accelerator mass spectrometry with (14)C measurement yields a calibrated age of these remains averaging 34,100 years before the present. The L3-L4 vertebrae exhibit marginal bone fusion on the right side with a smooth surface. They show 20- to 30-degree kyphosis secondary to wedge impaction of the L4 vertebral body. The facet joints and vertebral bodies reveal small marginal osteophytes with even joint surfaces, indicating low degenerative changes. Stetten 1 is characterized by the presence of a healed lumbar spine fracture. It documents the earliest known case thus far of spine fracture among modern humans.
Novel Formulation of Nonlocal Electrostatics
2004-09-02

The accurate modeling of the dielectric properties of water is crucial for many applications in physics, computational chemistry, and molecular biology. This becomes possible in the framework of nonlocal electrostatics, for which we propose a novel formulation allowing for numerical solutions for the nontrivial molecular geometries arising in the applications mentioned before. Our approach is based on the introduction of a secondary field psi, which acts as the potential for the rotation free part of the dielectric displacement field D. For many relevant models, the dielectric function of the medium can be expressed as the Green's function of a local differential operator. In this case, the resulting coupled Poisson (-Boltzmann) equations for psi and the electrostatic potential phi reduce to a system of coupled partial differential equations. The approach is illustrated by its application to simple geometries.
A 150 MG Magnetic White Dwarf in the Cataclysmic Variable RX J1554.2+2721
2004-09-03

We report the detection of Zeeman-split Lalpha absorption pi and sigma+ lines in the far-ultraviolet Hubble Space Telescope/Space Telescope Imaging Spectrograph spectrum of the magnetic cataclysmic variable RX J1554.2+2721. Fitting the STIS data with magnetic white dwarf model spectra, we derive a field strength of B~144MG and an effective temperature of 17000K<Teff<23000K. This measurement makes RX J1554.2+2721 only the third cataclysmic variable containing a white dwarf with a field exceeding 100MG. Similar to the other high-field polar AR UMa, RX J1554.2+2721 is often found in a state of feeble mass transfer, which suggests that a considerable number of high-field polars may still remain undiscovered.
Best linear forecast of volatility in financial time series
2004-09-03

The autocorrelation function of volatility in financial time series is fitted well by a superposition of several exponents. This case admits an explicit analytical solution of the problem of constructing the best linear forecast of a stationary stochastic process. We describe and apply the proposed analytical method for forecasting volatility. The leverage effect and volatility clustering are taken into account. Parameters of the predictor function are determined numerically for the Dow Jones 30 Industrial Average. Connection of the proposed method to the popular autoregressive conditional heteroskedasticity models is discussed.
Toward Understanding the Thermodynamic Viability of Zeolites and Related Frameworks through a Simple Topological Model
2004-09-04

Framework materials (e.g., zeolites, metallophosphates, chalcogenides, and metal organic frameworks) are widely used as catalysts, adsorbents, and ion exchangers. Although many different frameworks have been synthesized (or found in nature), numerous applications still call for frameworks with larger pores, lower framework densities, and/or higher specific absorption volumes than currently available. Thus, research into synthesizing novel framework materials with one or more of the desired properties has been extensively pursued in recent years, often however with no prior knowledge regarding their synthetic viability. In this study, we show how the decomposition of an archetypal class of framework materials (zeolites) into polyhedral tiles and the analysis of the face-size distribution obtained (using topological descriptors and periodic atomistic calculations on both synthesized and hypothetical frameworks) can lead to definite predictions regarding the thermodynamic viability of their synthesis. Moreover, it is demonstrated that pore size and framework density cannot be varied freely, but that they, at least for frameworks corresponding to simple tilings, are intimately connected to the thermodynamic viability of the framework's synthesis through its topology. These new insights allow us not only to rationalize the thermodynamic viability of a range of desirable (but as yet unmade) frameworks but also to begin to understand the physical and topological boundaries which inherently limit attempts to synthesize frameworks with ever-larger pores and lower framework densities. Although the methodology is validated for all-silica frameworks, the mode of investigation, due to its generality and nonreliance on specific geometric/chemical details, should be applicable to framework materials in general.
The Pigmentation of Human Iris Influences the Uptake and Storing of Zinc
2004-09-06

Age‐related macular degeneration (AMD) is more prevalent among the elderly Caucasians than in Africans. A significant association between light iris colour, fundus pigmentation and incidence of AMD is reported, suggesting a possible correlation with melanin pigment. Zinc is known to bind to melanin in pigmented tissues and to enhance antioxidant capacity by function as a cofactor or gene expression factor of antioxidant enzymes in the eye. In this in vitro study, we investigated the uptake and storage of zinc in human irides. Irides of blue and brown human eyes were used. The number of melanocytes was measured. Tissues without any treatment served as controls. The irides were incubated with 100 μ M zinc chloride in culture medium for 24 h. Specimens of the tissues were stored for the uptake examination. The remained pieces were further incubated for 3 and 7 d to investigate the storage of zinc. The concentration of zinc was measured by inductively coupled plasma mass spectrometry (ICP‐MS). Melanocytes count was significantly higher in the brown tissues (P &lt; 0.0001). Zinc concentration of blue coloured irides after 24 h zinc treatment was close to the controls. We did not observe any significant storing. In contrast, the concentration of zinc in brown irides was significantly increased after 24 h (P ≤ 0.01) and remained at a high level for 7 d. The uptake of zinc is likely dependent on the amount of pigmentation in human iris. Therefore, we assume that in patients suffering from AMD the degree of pigmentation of the irides and eventually fundi should be under consideration when the patients are treated with zinc supplementation.
Communication Analysis for Network-on-Chip Design
2004-09-07

In this paper we present an approach for the analysis of systems of parallel communicating processes, with regard to Network-on-Chip applications. We present a method to detect communications that synchronize the program flow of two or more processes. These synchronization points set the processes into relation and allow the determination of the global timing behavior of such a system. Using the results of our method for communication analysis, we present a new method to detect communications that might produce conflicts on shared communication resources. This information can be used to determine static routing in a packet routing network.
Developmental Regulation of Nicotinic Synapses on Cochlear Inner Hair Cells
2004-09-08

In the mature cochlea, inner hair cells (IHCs) transduce acoustic signals into receptor potentials, communicating to the brain by synaptic contacts with afferent fibers. Before the onset of hearing, a transient efferent innervation is found on IHCs, mediated by a nicotinic cholinergic receptor that may contain both α9 and α10 subunits. Calcium influx through that receptor activates calcium-dependent (SK2-containing) potassium channels. This inhibitory synapse is thought to disappear after the onset of hearing [after postnatal day 12 (P12)]. We documented this developmental transition using whole-cell recordings from IHCs in apical turns of the rat organ of Corti. Acetylcholine elicited ionic currents in 88-100% of IHCs between P3 and P14, but in only 1 of 11 IHCs at P16-P22. Potassium depolarization of efferent terminals caused IPSCs in 67% of IHCs at P3, in 100% at P7-P9, in 93% at P10-P12, but in only 40% at P13-P14 and in none of the IHCs tested between P16 and P22. Earlier work had shown by in situ hybridization that α9 mRNA is expressed in adult IHCs but thatα10 mRNA disappears after the onset of hearing. In the present study, antibodies toα10 and to the associated calcium-dependent (SK2) potassium channel showed a similar developmental loss. The correlated expression of these gene products with functional innervation suggests that Alpha10 and SK2 , but not Alpha9, are regulated by synaptic activity. Furthermore, this developmental knock-out of α10, but not α9, supports the hypothesis that functional nicotinic acetylcholine receptors in hair cells are heteromers containing both these subunits.
Polymer-phthalocyanine composite systems as solid state passive optical limiters
2004-09-08

The use of lasers as the driving force of information processing for future photonic technologies is almost inevitable. As a direct consequence of this the protecting of targets from high intensity stray optical beams, the most important being the eye, via optical limiting (high suppression of high intensity optical beams whilst allowing high transmission of ambient light) is a task of immediate importance. This contribution will discuss the application of metallo-phthalocyanine compounds doped into organic polymers to produce composite films to act as passive solid-state optical limiters. A range of phthalocyanines with different metals such as zinc, indium and vanadium substituted into the central cavity doped into the comercially available polymer poly(methyl)-methacrylate, PMMA, is investigated. The nonlinear responses exhibited by the systems are modelled and fitted using a three level orbital model to quantify the nonlinear activity in an effort to elucidate certain molecular design rules for the optical limiting application of the solid-state polymer-phthalocyanine composite. In addition to this the nature and physical properties of the films that are processed are also discussed.
[Reconstruction of a real car-pedestrian-accident. Part I: Generating an individual digital topographic image of the victim].
2004-09-08

The aim of forensic biomechanics is the reconstruction of traumatic events based on the pathological findings in the victim's morphology, the accident traces and the car damages. The use of forensic documentation tools (e.g. Streifenlichttopometrie) enables 3-dimensional and proportional accurate documentation of the victim's body, of its injuries and of the car damages with submillimeter precision. The generated topographic image serves as input for a multi-body system model of the victim. It allows further to determine exactly the contact points between car and victim for a computer simulated dynamical reconstruction of the impact situation. In the case of an accident involving a car and a pedestrian the generation and application of computer aided 3-dimensional reconstruction models are shown.
Arf1p Provides an Unexpected Link between COPI Vesicles and mRNA inSaccharomyces cerevisiae
2004-09-09

The small GTPase Arf1p is involved in different cellular processes that require its accumulation at specific cellular locations. The recruitment of Arf1p to distinct points of action might be achieved by association of Arf1p with different proteins. To identify new interactors of Arf1p, we performed an affinity chromatography with GTP- or GDP-bound Arf1p proteins. A new interactor of Arf1p-GTP was identified as Pab1p, which binds to the polyA-tail of mRNAs. Pab1p was found to associate with purified COPI-coated vesicles generated from Golgi membranes in vitro. The stability of the Pab1p–Arf1p complex depends on the presence of mRNA. Both symmetrically distributed mRNAs as well as the asymmetrically localized ASH1 mRNA are found in association with Arf1p. Remarkably, Arf1p and Pab1p are both required to restrict ASH1 mRNA to the bud tip. Arf1p and coatomer play an unexpected role in localizing mRNA independent and downstream of the SHE machinery. Hereby acts the SHE machinery in long-range mRNA transport, whereas COPI vesicles could act as short-range and localization vehicles. The endoplasmic reticulum (ER)–Golgi shuttle might be involved in concentrating mRNA at the ER.
Prognostic significance of serum HER2 and CA 15-3 at the time of diagnosis of metastatic breast cancer.
2004-09-09

Serum HER2 is a strong independent prognostic factor for survival after relapse in metastatic breast cancer even when adjusted for tumor load. Therefore, the prognostic significance of serum HER2 may not only be related to the tumor load but also to the biological behavior of the tumor.
Desulfoglucosinolate Sulfotransferases from Arabidopsis thaliana Catalyze the Final Step in the Biosynthesis of the Glucosinolate Core Structure
2004-09-10

The phytotoxin coronatine is a structural analog of octadecanoid signaling molecules, which are well known mediators of plant defense reactions. To isolate novel coronatine-regulated genes from Arabidopsis thaliana, differential mRNA display was performed. Transcript levels of CORI-7 (coronatine induced-7) were rapidly and transiently increased in coronatine-treated plants, and the corresponding cDNA was found to encode the sulfotransferase AtST5a. Likewise, upon wounding, an immediate and transient increase in AtST5a mRNA levels could be observed in both locally wounded and unwounded (systemic) leaves. Furthermore, application of octadecanoids and ethylene as compounds involved in plant wound defense reactions resulted in AtST5a gene activation, whereas pathogen defense-related signals (yeast elicitor and salicylic acid) were inactive. AtST5a and its close homologs AtST5b and AtST5c were purified as His6-tagged proteins from Escherichia coli. The three enzymes were shown to catalyze the final step in the biosynthesis of the glucosinolate (GS) core structure, the sulfation of desulfoglucosinolates (dsGSs). They accept a broad range of dsGSs as substrates. However, in a competitive situation, AtST5a clearly prefers tryptophan- and phenylalanine-derived dsGSs, whereas long chain dsGSs derived from methionine are the preferred substrates of AtST5b and AtST5c. Treatment of Arabidopsis plants with low concentrations of coronatine resulted in an increase in the amounts of specific GSs, primarily glucobrassicin and neoglucobrassicin. Hence, it is suggested that AtST5a is the sulfotransferase responsible for the biosynthesis of tryptophan-derived GSs in vivo.