julilili42/papers huggingface dataset:
Poly(ethylene-co-acrylic acid) Stationary Phases for the Separation of Shape-Constrained Isomers
2001-03-09

A new approach for the synthesis of long alkyl chain length stationary phases for use in reversed-phase liquid chromatography is described. Poly(ethylene-co-acrylic acid) copolymers (i.e., (-CH2CH2-)x[CH2CH(CO2H)-]y) with different levels of acrylic acid were covalently bonded to silica via glycidoxypropyl or aminopropyl linkages. 13C cross polarization magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR) spectroscopy was used to characterize the new reversed-phase materials. Aspects of shape selectivity were evaluated for six different columns with Standard Reference Material (SRM) 869a, Column Selectivity Test Mixture for Liquid Chromatography. Selectivity for isomer separations was enhanced for stationary phases prepared with poly(ethylene-co-acrylic acid) containing a mass fraction of 5% acrylic acid. The relationship between alkyl conformation and chromatographic properties was studied by 13C magic angle spinning (MAS) NMR measurements, and correlations were made with the composition of the polymer. Finally, the effectiveness of this phase is demonstrated by the separation of several beta-carotene isomers.
Linking experiencer-subject psych verb constructions in Modern Greek
2001-03-12

This paper focuses on the semantic properties and the syntactic behaviour of Modern Greek (hence MG) Experiencer-Subject Psych Verb Constructions (hence ESPVCs). MG ESPVCs include verbs like miso (hate), agapo (love), or latrevo (adore), which feature a nominative experiencer in agreement with the verb and an accusative theme (see examples (1)-(3)). MG ESPVCs include also predicates like fovame (fear), which feature an experiencer-subject in agreement with the verb and either an accusative theme (example (4)), or a theme as the object of a prepositional phrase (example (5)). We should underline here that examples (4) and (5) below convey the same meaning. That is, they do NOT differ semantically. O Gianis misi to sholio.the Gianis.N hate.3S the school.A"John hates school." O Gianis agapa tin Maria.the Gianis.N loves.3S the Maria.A"John loves Mary." O Gianis latrevi tin musiki.the Gianis.N adore.3S the music.A"John adores music." I Maria fovate tis kategides.the Maria.N fear.3S the storms.A"Maria is afraid of the storms." I Maria fovate me tis kategides.the Maria.N fear.3S with the storms.A"Maria is afraid of the storms." The challenge that constructions like the ones in (4) and (5) pose lies on the split syntactic realization of the "experienced" (hence EXPD) semantic role (i.e., the theme), which in constructions like (4) is syntactically realized as the object of the sentence, while in constructions like (5) it is syntactically realized as the object of a prepositional phrase. Our aim is to propose a unified linking account of the MG ESPVCs. This unified account is based on the assumption that the individual denoted by the object NP (or PP) of the MG ESPVCs is entailed to be semantically underspecified, and makes use of Wechsler's (1995) Notion Rule, Davis and Koenig's (2000) linking theory, as well as Markantonatou and Sadler's (1996) proposal for the linking of indirect arguments. References Davis, A.R. and J.-P. Koenig (2000). Linking as constraints on word classes in a hierarchical lexicon. Language 76, 56-91. Markantonatou, S. and L. Sadler (1996). Linking Indirect Arguments. Essex Research Reports in Linguistics 9, 24-63. Wechsler, S. (1995). The Semantic Basis of Argument Structure. Stanford: CSLI Publications. Series: Dissertations in Linguistics, Joan Bresnan, Sharon Inkelas, William J. Poser, and Peter Sells (eds.).
was-w construction in German
2001-03-12

The so-called was-w-construction in German has received a fair amount of attention in recent syntactic theorizing. Most of the discussion has focused on the properties of was.&#x0D; One line of research maintains that was is a scope marker that indicates the semantic scope of the wh-phrase in the embedded interrogative clause. The alternative view, usually referred to as the indirect analysis, was first developed with respect to Hindi (Dayal 1994) and then generalized to German (Dayal 1996). It holds that the was of the was-w-construction is associated not with the embedded wh-phrase, but rather with the embedded clause as a whole.&#x0D; Hinrichs and Nakazawa present some novel evidence in favor of an indirect analysis of the was-w construction. However, the main focus of their research is on two questions that by comparison have received little attention, namely:&#x0D; &#x0D; what is the set of matrix predicates that can enter into this construction, and&#x0D; how can one account for the curious fact that predicates that ordinarily do not license wh-complements allow such complements in the was-w-construction?&#x0D; &#x0D; On the basis of Ginzburg and Sag's verb classification (Ginzburg and Sag, in preparation) Hinrichs and Nakazawa identify a natural class of predicates that license this construction and utilize the notion of type coercion to account for the apparent mismatch between the syntactic form of the embedded interrogative and its semantic function.
Simulation-guided property checking based on a multi-valued AR-automata
2001-03-13

The verification of digital designs, i.e., hardware or embedded hardware/software systems, is an important task in the design process. Often more than 70% of the development time is spent for locating and correcting errors in the design. Therefore, many techniques have been proposed to support the debugging process. Recently, simulation and test methods have been accompanied by formal methods such as equivalence checking and property checking. However their industrial applicability is currently restricted to small or medium sized designs or to a specific phase in the design cycle. In this paper, we present a method for verifying temporal properties of systems described in an executable description language. Our method allows the user to specify properties about the system in finite linear time temporal logic. These properties are translated to a special kind of finite state machines which are then efficiently checked on-the-fly during each simulation run. Properties may be placed anywhere in the system description and violations are immediately indicated to the designer.
Sublethal irradiation promotes migration and invasiveness of glioma cells: implications for radiotherapy of human glioblastoma.
2001-03-15

Human malignant gliomas are highly lethal neoplasms. Involved-field radiotherapy is the most important therapeutic measure. Most relapses originate from the close vicinity of the irradiated target field. Here, we report that sublethal doses of irradiation enhance the migration and invasiveness of human malignant glioma cells. This hitherto unknown biological effect of irradiation is p53 independent, involves enhanced alphavbeta3 integrin expression, an altered profile of matrix metalloproteinase-2 and matrix metalloproteinase-9 (MMP-2 and MMP-9) expression and activity, altered membrane type 1 MMP and tissue inhibitor of metalloproteinases-2 expression, and an altered BCL-2/BAX rheostat favoring resistance to apoptosis. BCL-2 gene transfer and irradiation cooperate to enhance migration and invasiveness in a synergistic manner. Sublethal irradiation of rat 9L glioma cells results in the formation of a greater number of tumor satellites in the rat brain in vivo concomitant with enhanced MMP-2 and reduced tissue inhibitor of metalloproteinases-2 expression. Collectively, these data suggest that the current concepts of involved-field radiotherapy for malignant glioma need to be reconsidered and that the pharmacological inhibition of migration and invasion during radiotherapy may represent a new therapeutic approach to improve the therapeutic efficacy of radiotherapy for malignant glioma.
Soluble decoy receptor 3 is expressed by malignant gliomas and suppresses CD95 ligand-induced apoptosis and chemotaxis.
2001-03-15

Decoy receptor 3 (DcR3) is a newly identified soluble protein that binds to CD95 ligand (CD95L) and inhibits its proapoptotic activity. Here we report that DcR3 is expressed by the majority of long-term and ex vivo malignant glioma cell lines as well as in human glioblastoma in vivo. Expression of DcR3 correlates with the grade of malignancy: 15 of 18 (83%) glioblastomas (WHO grade IV) but none of 11 diffuse astrocytomas (WHO grade II) exhibited DcR3 immunoreactivity. We also demonstrate that human malignant glioma cells engineered to release high amounts of DcR3 into the cell culture supernatant are protected from CD95L-induced apoptotic cell death. In contrast, DcR3 does not confer protection from the death ligand Apo2 ligand (TRAIL). Importantly, ectopic expression of DcR3 resulted in substantial differences in immune cell infiltration in the 9L rat gliosarcoma model. Thus, the infiltration of CD4+ and CD8+ T cells as well as microglia/macrophages into glioma was substantially decreased in DcR3-producing tumors compared with control tumors. Chemotaxis assays revealed that DcR3 counteracts the chemotactic activity of CD95L against microglial cells in vitro. These findings suggest that DcR3 may be involved in the progression and immune evasion of malignant gliomas.
Fluorouracil Plus Leucovorin as Effective Adjuvant Chemotherapy in Curatively Resected Stage III Colon Cancer: Results of the Trial adjCCA-01
2001-03-15

PURPOSE: Adjuvant postoperative treatment with fluorouracil (5-FU) and levamisole in curatively resected stage III colon cancer significantly reduces the risk of cancer recurrence and improves survival. Biochemical modulation of 5-FU with leucovorin has resulted in increased remission rates in metastatic colorectal cancer, thus reflecting an increased tumor-cell kill. The impact of 5-FU plus leucovorin on survival and tumor recurrence was analyzed in comparison with the effects of 5-FU plus levamisole in the prospective multicentric trial adjCCA-01. PATIENTS AND METHODS: Patients with a curatively resected International Union Against Cancer stage III colon cancer were stratified according to T, N, and G category and randomly assigned to receive one of the two adjuvant treatment schemes: 5-FU 400 mg/m 2 body-surface area intravenously in the first chemotherapy course, then 450 mg/m 2 × 5 days; 12 cycles, plus leucovorin 100 mg/m 2 (arm A), or 5-FU plus levamisole (Moertel scheme; arm B). RESULTS: Six hundred eighty (96.9%) of 702 patients enrolled onto this study were eligible. After a median follow-up time of 46.5 months, the 5-FU plus leucovorin combination significantly improved disease-free survival (P = .037) and significantly decreased overall mortality (P = .0089) in comparison with 5-FU plus levamisole. In a multivariate proportional hazards model, adjuvant chemotherapy emerged as a significant prognostic factor for survival (P = .0059) and disease-free survival (P = .03). Adjuvant treatment with 5-FU plus levamisole as well as with 5-FU plus leucovorin was generally well tolerated; only a minority of patients experienced grade 3 and 4 toxicities. CONCLUSION: After a curative resection of a stage III colon cancer, adjuvant treatment with 5-FU plus leucovorin is generally well tolerated and significantly more effective than 5-FU plus levamisole in reducing tumor relapse and improving survival.
Novel Lysophospholipase A Secreted by Legionella pneumophila
2001-03-15

ABSTRACT We show that Legionella pneumophila possesses lysophospholipase A activity, which releases fatty acids from lysophosphatidylcholine. The NH 2 -terminal sequence of the enzyme contained FGDSLS, corresponding to a catalytic domain in a recently described group of lipolytic enzymes. Culture supernatants of a L. pneumophila pilD mutant lost the ability to cleave lysophosphatidylcholine.
Comparative study of protein tyrosine phosphatase-E isoforms: membrane localization confers specificity in cellular signalling
2001-03-15

To study the influence of subcellular localization as a determinant of signal transduction specificity, we assessed the effects of wild-type transmembrane and cytoplasmic protein tyrosine phosphatase (PTP) epsilon on tyrosine kinase signalling in baby hamster kidney (BHK) cells overexpressing the insulin receptor (BHK-IR). The efficiency by which differently localized PTPepsilon and PTPalpha variants attenuated insulin-induced cell rounding and detachment was determined in a functional clonal-selection assay and in stable cell lines. Compared with the corresponding receptor-type PTPs, the cytoplasmic PTPs (cytPTPs) were considerably less efficient in generating insulin-resistant clones, and exceptionally high compensatory expression levels were required to counteract phosphotyrosine-based signal transduction. Targeting of cytPTPepsilon to the plasma membrane via the Lck-tyrosine kinase dual acylation motif restored high rescue efficiency and abolished the need for high cytPTPepsilon levels. Consistent with these results, expression levels and subcellular localization of PTPepsilon were also found to determine the phosphorylation level of cellular proteins including focal adhesion kinase (FAK). Furthermore, PTPepsilon stabilized binding of phosphorylated FAK to Src, suggesting this complex as a possible mediator of the PTPepsilon inhibitory response to insulin-induced cell rounding and detachment in BHK-IR cells. Taken together, the present localization-function study indicates that transcriptional control of the subcellular localization of PTPepsilon may provide a molecular mechanism that determines PTPepsilon substrate selectivity and isoform-specific function.
Interlaboratory Evaluation of a New Reverse Transcriptase Polymerase Chain Reaction–Based Enzyme-Linked Immunosorbent Assay for the Detection of Circulating Melanoma Cells: A Multicenter Study of the Dermatologic Cooperative Oncology Group
2001-03-15

PURPOSE: Reverse transcription-polymerase chain reaction (RT-PCR)–based detection of tyrosinase mRNA is the most frequently used laboratory method for the detection of circulating tumor cells in melanoma patients. However, previously published results showed considerable variability in the PCR positivity rates. MATERIALS AND METHODS: We designed a collaborative study to assess the sensitivity, specificity, and clinical relevance of a new standardized RT-PCR–based enzyme-linked immunosorbent assay (ELISA) for the detection of circulating melanoma cells. Blood samples of healthy donors mixed with cells of a melanoma cell line were prepared in a blinded fashion, and aliquots were sent to seven participating laboratories experienced in RT-PCR. RESULTS: The results demonstrate a high sensitivity (1 melanoma cell/mL blood) and specificity (no false-negatives and 7.4% [2 of 28] false-positives) of the assay and a satisfactory rate of interlaboratory reproducibility. The analysis of aliquots of blinded samples derived from 60 melanoma patients identified tyrosinase mRNA in 17 of 60 (28.3%): three (20%) of 15 stage I patients, two (13.3%) of 15 stage II patients, five (35.7%) of 14 stage III patients, and seven (43.8%) of 16 stage IV patients. The interlaboratory reproducibility of positive samples, however, was extremely low and indicates the presence of low amounts of target mRNA. CONCLUSION: Reverse transcriptase-PCR ELISA has a high sensitivity and specificity for the detection of tyrosinase mRNA in peripheral blood cells. The low interlaboratory reproducibility for the detection of tumor cells in blood samples of melanoma patients, however, raises the question of relevance of this assay for clinical use.
Proton magnetic resonance spectroscopic imaging reveals differences in spinocerebellar ataxia types 2 and 6
2001-03-21

Abstract The objective of this study was to investigate cerebellar metabolism in patients with autosomal dominant cerebellar ataxia type 1 (ADCA‐I) carrying two distinct mutations of spinocerebellar ataxia (SCA). Non‐invasive image‐guided proton magnetic resonance spectroscopy imaging (1H‐MRSI) was performed in 4 patients with SCA2, and 3 patients carrying the SCA6 mutation. For MRSI, we employed a spin‐echo sequence (TR = 1500 msec, TE = 135 msec, slice thickness = 15 mm, FOV = 240 mm) and a stimulated‐echo sequence (TR = 1500 msec, TE = 20 msec, slice thickness = 15 mm, FOV = 240 mm). Measures included the peak integral ratios of neuronal and glial markers [N‐acetylaspartate (NA) to creatine (Cr), choline‐containing compounds (CHO) to Cr, and lactate (LAC) to Cr]. We found NA:Cr ratios were significantly lower in patients with SCA2 (40.4% lower) compared to patients carrying the SCA6 mutation. CHO:Cr ratios differed between the two mutations using short echo time (30.8% lower in SCA2), but not when applying long echo time 1H‐MRSI. Measurements using long echo time revealed LAC peaks in all SCA2 patients. 1H‐MRSI revealed metabolic differences between SCA2 and SCA6 patients. NA:Cr ratios were significantly lower in patients with the SCA2 mutation compared to the SCA6 mutation, and LAC signals were obtained in the cerebella of SCA2 patients. In addition, CHO:Cr ratios showed different behavior using short and long TE, indicating differences in relaxation times of choline compounds in SCA2. J. Magn. Reson. Imaging 2001;13:553–559. © 2001 Wiley‐Liss, Inc.
Brief communication: Neurotraumatological aspects of head injuries resulting from sharp and blunt force in the early medieval period of southwestern Germany
2001-03-22

Abstract Approximately 10% (33 of 304) of the predominantly male skulls from the 6th through 8th centuries in southwestern Germany exhibit cranial fractures derived from blunt or sharp force trauma. No evidence of fracture healing characterizes 24% (n = 8) of these individuals. All nonhealed fractures were caused by sharp force, and four of these wounds cross the sagittal sinus. The lengths of these straight‐edged wounds, produced exclusively by sword blows, measure around 8.0 cm for fatal, and about 5.0 cm for nonfatal wounds. Seventy‐six percent (n = 25) of these skulls exhibit some healing, which indicates that these injuries did not lead to immediate death. In this group are all depressed fractures resulting from blunt force blows. Two thirds of the 45 cranial injuries noted on these 33 skulls are located on the left side of these individuals, with a concentration in the frontoparietal region. Bony indications of wound infection occur in four cases (12%). Three crania exhibit circular trepanations in association with fractures. These phenomena are discussed in the context of modern neurotraumatological knowledge. Am J Phys Anthropol 114:352–356, 2001. © 2001 Wiley‐Liss, Inc.
Cardiac Output and Central Distribution of Blood Flow in the Human Fetus
2001-03-27

Background —The objectives of this study were to establish reference ranges for left and right cardiac output and to investigate blood flow distribution through the foramen ovale, ductus arteriosus, and pulmonary bed in human fetuses. Methods and Results —A prospective study was performed in 222 normal fetuses from 13 to 41 weeks of gestation with high-resolution color Doppler ultrasound. Cardiac output and ductal flow were calculated by use of vessel diameter and the time-velocity integral. Pulmonary blood flow was expressed as the difference between right cardiac output and ductal flow. Foramen ovale flow was estimated as the difference between pulmonary flow and left cardiac output. Gestational age–specific reference ranges are given for left, right, and biventricular output and volume of ductal blood flow, showing an exponential increase with gestational age. Median ratio of right to left cardiac output was 1.42 and was not associated with gestational age. Right cardiac output was 59% and left cardiac output was 41% of biventricular cardiac output. Median biventricular cardiac output was estimated to be 425 mL · min −1 · kg −1 fetal weight. Ductal blood flow was 46%, estimated pulmonary flow was 11%, and estimated foramen ovale flow was 33% of biventricular output. Conclusions —The study establishes reference ranges for fetal cardiac output and offers insights into the central blood flow distribution in human fetuses from 13 weeks to term. There is a clear right heart dominance. The estimated ratio of pulmonary blood flow to cardiac output is higher than in fetal lamb studies.
Capillary Electrochromatography
2001-03-29

Capillary electrochromatography (CEC) is a new and exciting hybrid separation technique that seeks to exploit the combined advantages of both capillary electrophoresis (high efficiencies) and HPLC (mobile and stationary phase selectivity). It is a technique with tremendous potential, especially in the pharmaceutical and biomedical fields. This is the first book to be devoted to the topic and presents reviews by the world leaders in the field on the theory and development of the technique and current and potential future applications. Capillary Electrochromatography provides an excellent introduction to the field for graduates and professionals in industry and academia with an interest in separation science.
A sequence motif responsible for ER export and surface expression of Kir2.0 inward rectifier K+ channels
2001-03-30

Integral membrane proteins are sorted via the secretory pathway. It was proposed that this pathway is non‐selective provided that the cargo protein is properly assembled and lacks an endoplasmic reticulum (ER) retention signal. However, recent experimental evidence suggests that efficient export of proteins from the ER to the Golgi complex is not simply a default pathway. Here we demonstrate a novel sequence motif (FxYENEV) in the cytoplasmic C‐terminus of mammalian inward rectifier potassium (Kir) channels which determines ER export. This motif is found to be both necessary and sufficient for efficient export from the ER that eventually leads to efficient surface expression of Kir2.1 channels.
Oral Glucose Tolerance Test Indexes for Insulin Sensitivity and Secretion Based on Various Availabilities of Sampling Times
2001-04-01

We have recently proposed a series of indexes for β-cell function and insulin sensitivity to be calculated from glucose and insulin concentrations obtained during a classic World Health Organization oral glucose tolerance test (OGTT) (1). The models were validated by the euglycemic-hyperinsulinemic and the hyperglycemic clamp technique, respectively. The generation of these indexes was based on simple statistical models using stepwise linear regression analysis. The variables in the model assumed the availability of determinations at 0, 30, ...