julilili42/papers huggingface dataset:
High precision film dosimetry with GAFCHROMIC® films for quality assurance especially when using small fields
2003-08-22

Treatment units for radiosurgery, brachytherapy, implementation of seeds, and IMRT generate small high dose regions together with steep dose gradients of up to 30%–50% per mm. Such devices are used to treat small complex‐shaped lesions, often located close to critical structures, by superimposing several single high dose regions. In order to test and verify these treatment techniques, to perform quality assurance tasks and to simulate treatment conditions as well as to collect input data for treatment planning, a GAFCHROMIC® film based dosimetry system for measuring two‐dimensional (2‐D) and three‐dimensional (3‐D) dose distributions was developed. The nearly tissue‐equivalent radiochromic GAFCHROMIC® film was used to measure dose distributions. A drum scanner was investigated and modified. The spectral emission of the light source and the filters together with the efficiency of the CCD filters for the red color were matched and balanced with the absorption spectra of the film. Models based on refined studies have been developed to characterize theoretically the physics of film exposure and to calibrate the film. Mathematical descriptions are given to calculate optical densities from spectral data. The effect of darkening has been investigated and is described with a mathematical model. The influence of the scan temperature has been observed and described. In order to cope with the problem of individual film inhomogeneities, a double irradiation technique is introduced and implemented that yields dose accuracies as good as 2%–3%. Special software routines have been implemented for evaluating and handling the film data.
Sensitivity of hemozoin detection by automated flow cytometry in non‐ and semi‐immune malaria patients
2003-08-22

Abstract Background Cell‐Dyn automated blood cell analyzers use laser flow cytometry technology, allowing detection of malaria pigment (hemozoin) in monocytes. We evaluated the value of such an instrument to diagnose malaria in febrile travelers returning to Berlin, Germany, the relation between the instrument's performance and the patients' immune status, and the capacity to increase its sensitivity. Methods Malaria diagnosis was routinely established by thick‐film microscopy. The patients' immune status was determined by an indirect fluorescent antibody test. Hemozoin detection was performed with a Cell‐Dyn 3000. To assess the capacity for sensitivity increase, the relative frequencies of pigment‐containing monocytes were determined for a subgroup of patients with the Cell‐Dyn 3000 in comparison with a flow cytometer specifically adapted to rare‐event analysis. Results Of 403 patients screened microscopically, 107 had malaria. Overall sensitivity with the Cell‐Dyn 3000 reached 48.6% (73.7% in semi‐immune and 28.6% in nonimmune individuals; P &lt; 0.0001). Specificity was 96.2%. The detection limit was at a relative concentration of 2 × 10 −4 pigment‐containing monocytes (PCMs). By employing rare‐event flow cytometry, the detection limit decreased to 3.25 × 10 −5 , thus yielding a considerably increased sensitivity for the subgroup studied. Conclusions The correlation between immune status and relative concentration of PCMs explains the failure of the routine instrument for nonimmune patients and its significantly higher sensitivity for semi‐immune individuals. The technique can be significantly improved by rare‐event flow cytometry. Cytometry Part B (Clin. Cytometry) 55B:46–51, 2003. © 2003 Wiley‐Liss, Inc.
Geochemistry and Geochronology of Gneiss Pebbles from Foreland Molasse Conglomerates: Geodynamic and Paleogeographic Implications for the Oligo‐Miocene Evolution of the Eastern Alps
2003-08-22

Gneiss pebbles, deposited in foreland fans during the Miocene Epoch, were studied with geochemical and thermochronological methods to reconstruct the paleodrainage evolution of the Eastern Alps and the geodynamic behavior of the source areas. Clear discrimination between upper‐plate Austroalpine and lower‐plate Penninic gneiss pebbles was achieved by single‐pebble paleocooling paths. Austroalpine gneisses showed highly variable and regionally distinctive paleocooling paths, which record Variscan to Cretaceous Rb‐Sr and K‐Ar cooling ages. Penninic gneisses showed Paleogene to lower Miocene high‐temperature (Rb‐Sr, K‐Ar) and Miocene low‐temperature (zircon and apatite fission track) cooling ages. Cooling rates of Penninic gneisses indicate maximum exhumation rates at ∼17 Ma during the climax of lateral tectonic extrusion, recording dominance of tectonic unroofing. The paleodrainage evolution was characterized by a relatively stable catchment configuration in the western part of the Eastern Alps, where northward radial dewatering to fixed foreland entry points was documented throughout molasse sedimentation in Oligo‐Miocene times. The largest river system, represented by the Paleo‐Inn River, displayed a considerably larger catchment area than today and variable entry points into the foreland. The drainage pattern of the eastern part of the Eastern Alps was governed by the fault pattern that developed during lateral extrusion. Penninic basement rocks first became exposed in the eastern part of the Tauern window at ∼13 Ma, some 4 m.yr. after the climax of tectonic unroofing.
Structural Evaluation of Systematically Enumerated Hypothetical Uninodal Zeolites
2003-08-22

Theoretisch betrachtet: 139 unterschiedliche Zeolithstrukturen sind bereits bekannt – dennoch ist die Suche nach weiteren Architekturen in Hinblick auf Anwendungen in der Katalyse oder als Ionenaustauscher von außerordentlicher Bedeutung. Durch Fortschritte in der Pflasterungstheorie konnten 294 uninodale Netze mit der empirischen Formel SiO2 identifiziert werden; das Bild zeigt ein stabiles Beispiel. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2003/z51556_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Coordinated Adenine Nucleotide Phosphohydrolysis and Nucleoside Signaling in Posthypoxic Endothelium
2003-08-25

Limited oxygen delivery to tissues (hypoxia) is common in a variety of disease states. A number of parallels exist between hypoxia and acute inflammation, including the observation that both influence vascular permeability. As such, we compared the functional influence of activated polymorphonuclear leukocytes (PMN) on normoxic and posthypoxic endothelial cells. Initial studies indicated that activated PMN preferentially promote endothelial barrier function in posthypoxic endothelial cells (&amp;gt;60% increase over normoxia). Extension of these findings identified at least one soluble mediator as extracellular adenosine triphosphate (ATP). Subsequent studies revealed that ATP is coordinately hydrolyzed to adenosine at the endothelial cell surface by hypoxia-induced CD39 and CD73 (&amp;gt;20-and &amp;gt;12-fold increase in mRNA, respectively). Studies in vitro and in cd39-null mice identified these surface ecto-enzymes as critical control points for posthypoxia-associated protection of vascular permeability. Furthermore, insight gained through microarray analysis revealed that the adenosine A2B receptor (AdoRA2B) is selectively up-regulated by hypoxia (&amp;gt;5-fold increase in mRNA), and that AdoRA2B antagonists effectively neutralize ATP-mediated changes in posthypoxic endothelial permeability. Taken together, these results demonstrate transcription coordination of adenine nucleotide and nucleoside signaling at the vascular interface during hypoxia.
Proceedings of the ACM SIGCOMM workshop on Models, methods and tools for reproducible network research
2003-08-25

Compared with other scientific areas such as experimental physics, network research appears significantly less mature concerning methodology. Internet research is affected by models that sometimes are poorly suited to the problem under investigation, by lack of understanding of properties and limitations of the models used, and by tools that have various limitations and that are poorly integrated. While each of the methods analysis, simulation, emulation, testbed experiments and Internet-wide experiments have their own particular strengths and shortcomings, typically only one of these methods is used to investigate a particular problem. Certain weaknesses of the chosen methods can have unwanted implications on the results and deductions made from them. There appears to be insufficient comparison or adjustment between results obtained by different methods.The goal of this workshop was to critically assess the current models, methods and tools for identifying shortcomings of the state-of-the-art, and to discuss approaches for improvements and innovation. The workshop aimed for sharing knowledge about how to apply today's tools most successfully, and for generating a common understanding about what is needed for network research to progress more rapidly and to ensure widely reproducible results.A great deal of effort has gone into putting together a high-quality program. The quality of submissions was very high, and the program committee had a difficult task to select eleven papers among many deserving papers.
Sodium and calcium currents shape action potentials in immature mouse inner hair cells
2003-08-26

Before the onset of hearing at postnatal day 12, mouse inner hair cells (IHCs) produce spontaneous and evoked action potentials. These spikes are likely to induce neurotransmitter release onto auditory nerve fibres. Since immature IHCs express both α1D (Ca v 1.3) Ca 2+ and Na + currents that activate near the resting potential, we examined whether these two conductances are involved in shaping the action potentials. Both had extremely rapid activation kinetics, followed by fast and complete voltage‐dependent inactivation for the Na + current, and slower, partially Ca 2+ ‐dependent inactivation for the Ca 2+ current. Only the Ca 2+ current is necessary for spontaneous and induced action potentials, and 29 % of cells lacked a Na + current. The Na + current does, however, shorten the time to reach the action‐potential threshold, whereas the Ca 2+ current is mainly involved, together with the K + currents, in determining the speed and size of the spikes. Both currents increased in size up to the end of the first postnatal week. After this, the Ca 2+ current reduced to about 30 % of its maximum size and persisted in mature IHCs. The Na + current was downregulated around the onset of hearing, when the spiking is also known to disappear. Although the Na + current was observed as early as embryonic day 16.5, its role in action‐potential generation was only evident from just after birth, when the resting membrane potential became sufficiently negative to remove a sizeable fraction of the inactivation (half inactivation was at −71 mV). The size of both currents was positively correlated with the developmental change in action‐potential frequency.
Modulation of Whole‐Cell Currents in Plasmodium Falciparum‐Infected Human Red Blood Cells by Holding Potential and Serum
2003-08-26

Recent electrophysiological studies have identified novel ion channel activity in the host plasma membrane of Plasmodium falciparum ‐infected human red blood cells (RBCs). However, conflicting data have been published with regard to the characteristics of induced channel activity measured in the whole‐cell configuration of the patch‐clamp technique. In an effort to establish the reasons for these discrepancies, we demonstrate here two factors that have been found to modulate whole‐cell recordings in malaria‐infected RBCs. Firstly, negative holding potentials reduced inward currents (i.e. at negative potentials), although this result was highly complex. Secondly, the addition of human serum increased outward currents (i.e. at positive potentials) by approximately 4‐fold and inward currents by approximately 2‐fold. These two effects may help to resolve the conflicting data in the literature, although further investigation is required to understand the underlying mechanisms and their physiological relevance in detail.
On the cranial osteology of the short-tailed opossum Monodelphis brevicaudata (Didelphidae, Marsupialia)
2003-08-27

The Section of Mammals, Carnegie Museum of Natural History houses 54 partial and complete skulls of the short-tailed opossum Monodelphis.Described in detail and illustrated are the external surfaces of the bones of the skull for M. brevicaudata CM 52729 and the external and internal surfaces of one bone of the basicranium, the petrosal, for Monodelphis sp.CM 5024.The disposition of cranial foramina ranging in size from the foramen magnum to tiny emissary and nutrient foramina was studied in all 54 specimens, which in addition to 16 M. brevicaudata, includes four M. dimidiata, 29 M. domestica, two M. osgoodi, and three Monodelphis sp.Three categories of foramina were identified: (1) foramina bilaterally present in all specimens that show no significant variation; (2) bilateral and midline foramina present in ail specimens that show variation in size, number, position, distinctness from other foramina, or elements contributing to their walls; and (3) foramina that are not present in ail specimens that also vary in size, number, and position.Comparisons were made with four outgroups, the didelphid Didelpkis albiventris, the dasyurid Dasyurus maculatus, the early Paleocene metatherian Pucadelphys andinus, and the Late Cretaceous eutherian Zalambdalestes lechei, in order to evaluate the foramina of Monodelphis in a phylogenetic context.Of the foramina considered here, four distinguish Monodelphis; three distinguish Didelphidae; 15 distinguish Marsupialia; nine distinguish Metatheria; and seven occur across Theria.
Cognitive processing in completely paralyzed patients with amyotrophic lateral sclerosis
2003-08-27

Cognitive functions have never been studied before in completely paralyzed patients, probably due to the lack of the appropriate method. In this study, three male patients in the last stage of amyotrophic lateral sclerosis (ALS) are examined. They were totally locked‐in, i.e., incapable of any voluntary response including eye movements. Given this complete lack of motor expression, the method of event‐related brain potentials (ERPs) was used. The ERP recording was carried out at the patients’ bedside. In one patient indications of preserved cognitive abilities including adequate language comprehension were obtained. The data of the second patient also demonstrate a high degree of intactness of complex cognitive functions, but some ERP phenomena were consistently abnormal, which may be interpreted as a consequence of disease‐related degenerative processes. In the third patient no electrocortical response which might indicate higher cortical processing was found. This first ERP study of totally paralyzed patients shows that some of them can possess high, perhaps even normal, information processing capacity after a long period of severe immobility and artificial ventilation.
Role of eicosanoids in structural degradation in osteoarthritis
2003-08-27

Prostaglandins play a significant role not only in joint physiology, but also in the pathogenesis of joint disorders. In addition, it has been identified that osteoarthritis subchondral osteoblasts can synthesize leukotriene B4, indicating a role of leukotrienes in bone remodeling associated with osteoarthritis. A therapeutic intervention that blocks lipoxygenase/cyclooxygenase pathways, thereby inhibiting production of prostaglandins and leukotrienes, may therefore be very attractive for the treatment of osteoarthritis patients.
Monocyte chemoattractant protein–1 increases microglial infiltration and aggressiveness of gliomas
2003-08-28

Abstract Macrophages are thought to represent a first line of defense in anti‐tumor immunity. Despite infiltration by microglial cells, however, malignant gliomas are still highly aggressive tumors. We here identify monocyte chemoattractant protein‐1 (MCP‐1) as a critical chemoattractant for glioma‐infiltrating microglial cells. MCP‐1–transfected rat CNS‐1 gliomas were massively infiltrated by microglial cells. Whereas MCP‐1 did not promote the growth of CNS‐1 cells in vitro, intracerebral CNS‐1–transfected tumors grew more aggressively than control‐transfected tumors. This provides the first functional evidence that MCP‐1 recruits microglial cells to gliomas and promotes their growth in vivo. Microglial cells may support rather than suppress glioma growth.
Clinical features and neuropathology of autosomal dominant spinocerebellar ataxia (SCA17)
2003-08-28

Abstract Autosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative disorders clinically characterized by late‐onset ataxia and variable other manifestations. Genetically and clinically, SCA is highly heterogeneous. Recently, CAG repeat expansions in the gene encoding TATA‐binding protein (TBP) have been found in a new form of SCA, which has been designated SCA17. To estimate the frequency of SCA17 among white SCA patients and to define the phenotypic variability, we determined the frequency of SCA17 in a large sample of 1,318 SCA patients. In total, 15 patients in four autosomal dominant SCA families had CAG/CAA repeat expansions in the TBP gene ranging from 45 to 54 repeats. The clinical features of our SCA17 patients differ from other SCA types by manifesting with psychiatric abnormalities and dementia. The neuropathology of SCA17 can be classified as a “pure cerebellar” or “cerebello‐olivary” form of ataxia. However, intranuclear neuronal inclusion bodies with immunoreactivity to anti‐TBP and antipolyglutamine were much more widely distributed throughout the brain gray matter than in other SCAs. Based on clinical and genetic data, we conclude that SCA17 is rare among white SCA patients. SCA17 should be considered in sporadic and familial cases of ataxia with accompanying psychiatric symptoms and dementia.
Neuro-Oncology Working Group 01 Trial of Nimustine Plus Teniposide Versus Nimustine Plus Cytarabine Chemotherapy in Addition to Involved-Field Radiotherapy in the First-Line Treatment of Malignant Glioma
2003-08-28

Purpose: The role of chemotherapy in the primary treatment of malignant glioma remains controversial. The results from the German-Austrian Glioma trial (GAG, 1983 to 1988) demonstrated a survival benefit for chemotherapy using carmustine (BCNU) plus teniposide (VM26) over BCNU alone in addition to radiotherapy in patients with a Karnofsky performance score (KPS) more than 60. The Neuro-Oncology Working Group (NOA) of the German Cancer Society therefore compared the efficacy of nimustine (ACNU) plus VM26 and ACNU plus cytarabine (Ara-C) chemotherapy in addition to standard radiotherapy in patients with newly diagnosed malignant glioma. Patients and Methods: From 1994 to 2000, 375 patients were randomly assigned to receive radiotherapy and cycles of ACNU 90 mg/m 2 intravenously (IV) on day 1 and VM26 60 mg/m 2 IV on days 1 to 3 (n = 183), or ACNU 90 mg/m 2 IV on day 1 and Ara-C 120 mg/m 2 IV on days 1 to 3 (n = 179), in 6-week intervals. Thirteen patients were not eligible after central neuropathology review. The remaining 362 patients had glioblastoma (n = 301) or anaplastic glioma (n = 61). Results: Median survival and 2-year survival rates were 17.3 months and 25% for ACNU plus VM26, and 15.7 months and 29% for ACNU plus Ara-C in glioblastoma, and 60 months and 88% for ACNU plus VM26 and 62.5 months and 72% for ACNU plus Ara-C in anaplastic glioma. Multivariate analysis revealed no survival advantage for either arm or for subpopulations defined by histology, age, or KPS. Hematologic toxicity was more prominent in the ACNU plus Ara-C arm. Conclusion: The median survival times and 2-year survival rates for patients with anaplastic glioma and glioblastoma achieved in the NOA-01 trial compare favorably with historical trials and with the Radiation Therapy Oncology Group database. The toxicity profile favors ACNU plus VM26 for further evaluation.
The colicin G, H and X determinants encode microcins M and H47, which might utilize the catecholate siderophore receptors FepA, Cir, Fiu and IroN
2003-08-29

The colicin G producer Escherichia coli CA46, the colicin H producer E. coli CA58 and E. coli Nissle 1917 (DSM 6601) were shown to produce microcin H47 and the newly described microcin M. Both microcins were exported like colicin V by an RND-type export system, including TolC. The gene cluster encoding microcins H47 and M in strains CA46 and CA58 is nearly identical to that in strain DSM 6601, except that two additional genes are included. A Fur box identified in front of the microcin-encoding genes explained the observed iron regulation of microcin production. The catecholate siderophore receptors Fiu, Cir and FepA from E. coli and IroN, Cir and FepA from Salmonella were identified as receptors for microcins M, H47 and E492. IroN takes up the glucose-containing catecholate siderophore salmochelin, whose synthesis is encoded in the iro gene cluster found in Salmonella and certain, often uropathogenic, E. coli strains. A gene in this iro cluster, iroB , which encodes a putative glycosyltransferase, was also found in the microcin H47/M and microcin E492 gene clusters. These microcins could aid the producing strain in competing against enterobacteria that utilize catecholate siderophores.
Protein Kinase Cδ Induces Src Kinase Activity via Activation of the Protein Tyrosine Phosphatase PTPα
2003-08-29

Previously we have shown that protein kinase C (PKC)-mediated reorganization of the actin cytoskeleton in smooth muscle cells is transmitted by the non-receptor tyrosine kinase, Src. Several authors have described how 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulation of cells results in an increase of Src activity, but the mechanism of the PKC-mediated Src activation is unknown. Using PKC isozymes purified from Spodoptera frugiperda insect cells, we show here that PKC is not able to activate Src directly. Our data reveal that the PKC-dependent Src activation occurs via the activation of the protein tyrosine phosphatase (PTP) PTP alpha. PTP alpha becomes activated in vivo after TPA stimulation. Further, we show that PKC delta phosphorylates and activates only PTP alpha in vitro but not any other of the TPA-responsive PKC isozymes that are expressed in A7r5 rat aortic smooth muscle cells. To further substantiate our data, we show that cells lacking PKC delta have a markedly reduced PTP alpha and Src activity after 12-O-tetradecanoylphorbol-13-acetate stimulation. These data support a model in which the main mechanism of 12-O-tetradecanoylphorbol-13-acetate-induced Src activation is the direct phosphorylation and activation of PTP alpha by PKC delta, which in turn dephosphorylates and activates Src.