julilili42/papers huggingface dataset:
Shoot Responses of Six Lythraceae Species to Flooding
2001-03-01

Abstract: The large family Lythraceae has several genera and species that show tolerance to flooding; one species, Lythrum salicaria (purple loosestrife), is considered invasive in North American wetlands. It is not clear, however, which characteristic(s) contribute to the invasive nature of L. salicaria, but those that contribute to improved flood tolerance may be responsible. This study examined the response of the shoot system of several members of the Lythraceae, three Lythrum species (L. salicaria, L. hyssopifolia, L. alatum), Decodon verticillatum, Pleurophora anomala and Heimia myrticifolia, to flooding to determine if these species differ in their response in comparison to L. salicaria. All species, except L. hyssopifolia, responded to flooding by increasing total plant height. All species, except H. myrticifolia, formed a phellem of significantly wider diameter at the stem base of flooded plants compared to controls. This phellem consisted of alternating bands of small, isodiametric cells and radially elongated cells separated by large air lacunae forming a very specialized aerenchyma. The small cells had Casparian band‐like wall modifications and occasionally displayed modifications that included all cell wall surfaces. The development of extensive aerenchymatous phellem in flooded plants may increase the air space continuum from shoot to root in shoots that have undergone secondary growth. Given that these species displayed similar responses to flooding, the purported invasiveness of L. salicaria cannot be attributed to presence of any of the characteristics studied.
Displacement Mapping using Scan Conversion Hardware Architectures
2001-03-01

This paper presents a novel algorithm and architectures for perspective correct displacement of the surface geometry of a polygonal model using a displacement map. This new displaced surface geometry is passed onto a traditional rendering pipeline. The algorithm uses a multiple pass approach in which the geometry is displaced in the first pass and then the displaced geometry is rendered. The significant features of the algorithm are that the surface is displaced after its triangle mesh is transformed into screen space and that it uses only bi‐linear interpolation for calculating the displaced geometry allowing a cheap incremental scan‐line implementation. A hardware architecture based on this algorithm is presented along with possible alternative implementations. The technique presented here allows greater photorealism by using increased detail without an increase in bandwidth for geometry or calculation time for transformation.
Effect of precursor powder properties on magnetic and electrical transport properties of (Bi,Pb)-2223-tapes
2001-03-01

The quality of superconducting silver clad (Bi,Pb)-2223-tapes essentially depends on the applied precursor powder. The choice of the processing parameters of the precursor preparation (calcination procedure) is decisive for the current carrying capability of tapes. The properties of 2212 and the occurence of secondary phases in precursors can be regulated by partial oxygen pressure, temperature, and time in the calcination annealing. Precursors containing orthorhombic (Bi,Pb)-2212 with high T/sub c/ without Pb/sup 4+/-phases yield high critical currents.
Production, purification and some properties of Bac201, a bacteriocin-like inhibitory substance produced byStaphylococcus aureus AB201
2001-03-01

Staphylococcus aureus AB201, a clinical isolate from wound pus, produced a bacteriocin-like inhibitory substance termed as Bac201, that was inhibitory to Streptococcus agalactiae, Enterococcus faecalis, Acinetobacter calcoaceticus, Neisseria meningitidis and a number of staphylococcal species. It was purified to homogeneity by ammonium sulfate precipitation, gel filtration (BioSil-SEC-125), and reversed-phase high performance liquid chromatography (Vydac C4). The native Bac201 was sized at approximately 170-kDa as determined by GF HPLC. Fraction-I (native Bac201), having antibacterial activity was also examined by transmission electron microscopy and appeared as globular structure showing resemblance with phage-like objects. The purification of Bac201 resulted in 466-fold increase in specific activity and recovery of 0.94% of total antibacterial activity. The purified Bac201 migrated as single band on SDS-PAGE with an estimated molecular mass of about 41-kDa. Bac201 was sensitive to proteolytic enzymes, resistant to heat and organic solvents, and active over a wide range of pH (2.5-10). The amino acid composition revealed a general resemblance with other reported high molecular mass bacteriocins and predominance of glycine (39%), proline (13%) and alanine (8%) residues. Further results showed that Bac201 has a bactericidal effect on sensitive cells which is not produced by either cell lysis or apparent loss of membrane permeability.
Total Synthesis of S-(+)-Argentilactone
2001-03-01

Abstract Asymmetrie Total Synthesis Asymmetrie total synthesis of S-(+)-argentilactone (2) was accomplished, using methyl-a-D-glucopyranoside (3) as carbohydrate template. Benzylidene acetal 5 was hydrolysed with t BuOOH/AlCl 3 and further manipulated to produce the aldehyde 10. A Wittig reaction and subsequent oxidation of the anomeric position yielded the target argentilactone.
MRI diagnosis of a previously undiagnosed large trabecular ventricular septal defect in an adult after multiple catheterizations and angiocardiograms
2001-03-01

Ventricular septal defect (VSD) is the most frequent congenital heart disease (25-30%). The diagnosis of VSD is usually made echocardiographically by means of colour Doppler ultrasound, and is confirmed by angiocardiography in most cases. We describe a case in which an additional large trabecular VSD was demonstrated by MRI after previous cardiac catheterizations and angiocardiography in various hospitals. MRI allows an exact presentation of the anatomy, including areas that are difficult to assess, for instance the apical septum. Determination of cardiac output, regurgitation volume and the Qp/Qs quotient in patients with shunt volume in heart defects is also possible with one examination.
Synthesis and Cyclooxygenase Inhibitory Properties of Novel (+) 2-(6-Methoxy-2-naphthyl)propanoic Acid (Naproxene) Derivatives
2001-03-01

Halomethylation of naproxene (1) occurs regioselectively in position 5 and subsequently--in situ or on treatment with silver nitrate--leads to naproxene-"dimers" with two naproxene units, 5,5'-connected through a ethenylene (3) and a methylene (4) bridge, respectively. Two of the new naproxene derivatives were screened for their cyclooxygenase inhibitory properties relative to naproxene. Both 5-chloromethyl naproxene (2) and 2-(5-((carboxyethyl)-2-methyloxynaphthyl)-6-methoxy-2-naphthyl)propanoic acid (4) were inactive in the concentration range of 0.1-10 mumole against both COX-1 and COX-2, indicating that bulky substituents in position 5 in naproxene are unfavourable for both COX-1 and COX-2 inhibition.
LC-resonant voltage response of superconducting quantum interference filters
2001-03-01

The voltage vs. magnetic field relation V(B) of superconducting interferometers consisting of two or more Josephson junctions is the basic characteristic of their operation as highly sensitive magnetometers and amplifiers. The conversion efficiency /spl part/V//spl part/B of interferometers containing two Josephson junctions, i.e. dc SQUIDs, decreases significantly with increasing loop inductance L. Therefore, the range of SQUID loop sizes for which the SQUID operates properly is very restricted. However, for sufficient coupling between the SQUID and the signal coil a large value of L is desirable. In this work theoretical and experimental results on the voltage response function of quantum interference filters (SQIFs) are presented. A SQIF consists of N Josephson junctions connected in parallel to form a 1D array. The array loop sizes are chosen such that the voltage response becomes a unique function around B=0. It is shown that for McCumber parameters /spl beta//sub C/>0.5 and sufficiently large array inductances the V(B) relation of SQIFs shows LC-resonances that lead to two pronounced minima in the response function. In the LC-resonant operation mode the conversion efficiency of SQIFs is not degraded even for large array inductances. By this, a very strong coupling to signal coils can be achieved. The experimental results agree very well with the theoretical predictions on which basis the SQIF has been fabricated.
The effect of human serum DNAases on the ability to detect antibiotic-killed Escherichia coli in blood by PCR
2001-03-01

PCR has proved superior to conventional blood culture for diagnosing bacteraemia in the presence of antibiotics. Nevertheless, even PCR might yield false-negative results if the template DNA were to be cleaved by serum DNAases after antibiotics had induced bacterial death. To evaluate the cleavage of bacterial template DNA by human serum DNAase I, serum samples inoculated with purified Escherichia coli DNA were incubated with increasing amounts of recombinant human DNAase (rhDNAase) and then examined by a PCR specific for E. coli. As a prerequisite of potential DNAase attack, the release of E. coli DNA after antibiotic-induced bacterial death was quantified by fluorescence microscopy and flow cytometry. Finally, the influence of rhDNAase on the PCR-based detection of antibiotic-killed E. coli in serum was assessed. The results indicated that purified E. coli DNA is remarkably stable in human serum; positive PCR results did not decrease significantly until the ratio of recombinant human DNAase I:E. coli rose to 106:1. As only 14.8-28.4% of the total E. coli DNA was released after antibiotic killing, the PCR-based detection of E. coli fell by only 10% when cefotaxime-killed E. coli were incubated with rhDNAase. It was concluded that human serum DNAases and antibiotic killing do not compromise the reliability of PCR examinations for bacteraemia.
The Analgesic Potency of NMDA-Antagonists—A Question of Mechanism-based Use and Timing?
2001-03-01

To the Editor: We would like to contribute to the discussion of the excellent work by Nikolajsen et al. (1), a well designed and carefully conducted study of the effect of a memantine on neuropathic pain after amputation or surgery. The authors concluded that memantine at a dosage of 20 mg/d does not reduce spontaneous nor evoked pain inpatients with nerve injury pain. Successful treatment of chronic neuropathic pain remains difficult; often insufficient pain relief is achieved (2,3). However, subjects of Nikolajsen et al. (1) were patients with established chronic pain (duration between 1–28 yr). Data, suggesting a clinical role of N-methyl-d-aspartate (NMDA)-antagonists in chronic neuropathic pain are so far mainly based on single cases or a small series of patients and the use of ketamine (4–5). The exact clinical role of NMDA-blockade remains to be investigated (2,3,6,7). Strong experimental evidence points at a substantial role of the NMDA-receptor initiating central sensitization possibly leading to persistent pain-states (2,3,6–8). Consecutively, the use of NMDA-receptor antagonists in the early postinjury phase, or even before, may blunt or even preempt central sensitization and the subsequent development of chronic pain. From this point of view, the therapeutic efficacy of NMDA-antagonists once chronic pain is established seems to be questionable (2,3). Ralph-Thomas Kiefer, MD Unertl Klaus Katja Wiech, Dr. soz., Dipl. Psych Niels Birbaumer, PhD
Eliciting Paresthesias for Peripheral Nerve Block: A Harmful Clinical Standard?
2001-03-01

To the Editor: I have read with great interest the article by Sia et al. (1) comparing onset time and success rate of the multiple injection axillary brachial plexus block performed with neurostimulation guidance versus paresthesia elicitation. I would like to express my general concern against the use of needle-evoked paresthesia for peripheral nerve blocks. Recently, Kaufman et al. (2) reported a series of seven patients suffering from severe, debilitating chronic pain states after peripheral nerve blocks. In all seven cases, painful paresthesias were elicited at the time of the nerve block, be they voluntary or accidental, with a progress to a severe chronic pain condition. Neurological complications following peripheral nerve blocks, referred to as postblock neuralgia, show an incidence of 0.2%(3), 1.7%(4) up to 12.5%(5). Symptoms mostly are moderate and transitory, with a tendency of spontaneous recovery within times related to nerve regeneration and repair mechanisms (6). Therefore, I feel that deliberate needle-elicited paresthesias are at least a questionable clinical standard because growing strong evidence exists that even minor nerve damage can proceed to intractable chronic pain (7). Thus, the principle “primum non nocere” should be kept in mind when performing peripheral nerve blocks to assure maximum patient safety. Ralph-Thomas Kiefer, MD
Recognition of chronic myelogenous leukaemia cells by autologous T lymphocytes primed in vitro against the patient's dendritic cells
2001-03-01

Defects in immune responses are common in patients with chronic myelogenous leukaemia (CML). However, using dendritic cells (DCs) to promote T‐cell immunity in vitro may nonetheless elicit potent specific anti‐tumour responses for use in immunotherapy. Here, we show that DCs generated from CML patients had a typical dendritic phenotype and were able to stimulate autologous T cells. Three primed T‐cell lines were studied in more detail in one patient. They were stimulated by autologous CML cells, but not by normal non‐leukaemic cells from the patient's HLA‐identical sibling. This was blocked by HLA‐DR‐specific, but not HLA‐DQ‐ or HLA‐DP‐specific antibodies. CML‐stimulated cytokine secretion, including interferon‐γ and granulocyte macrophage‐colony stimulating factor, suggested a Th1‐type phenotype for these sensitized anti‐leukaemic T cells. This study therefore shows that cells with a functional dendritic phenotype can be generated from the blood of CML patients and are potent inducers of T‐cell responses to tumour cells. This approach allows sensitization of patients' T cells by their own particular tumour without the need to identify the exact leukaemia antigens involved, and may find application in immunotherapy of CML.
Vortex pairs and nonlinear inductance of high-T/sub c/ superconducting microwave resonators
2001-03-01

Recently, an unusual power dependence of two-tone intermodulation has been observed in high-T/sub c/ superconducting microwave resonators. In order to address this problem, we study the nonlinear response of a two dimensional Josephson junction array as a coupled grain model for the high-T/sub c/ films. On a microscopic scale the calculated current distributions within the array show a strong tendency to form topological Josephson vortices which organize themselves in vortex-antivortex clusters even in the absence of an external magnetic field. These vortex clusters are stable within an external ac drive and cause a redistribution of the input current. The resulting current distributions possess pronounced transversal components. On the macroscopic scale such current distributions lead to a nonlinear inductance that varies linearly with the magnitude of the input current consistent with the observed power dependence. This result suggests the dynamics of topological Josephson vortices within the coupled grains as a possible explanation for the unusual nonlinear response.
Properties and applications of the (2‐nitrofluoren‐9‐yl)methoxycarbonyl group
2001-03-01

Abstract This paper presents a new protecting group, the (2‐nitrofluoren‐9‐yl)methoxycarbonyl group. Investigations on the properties of this new modification of the Fmoc‐system, such as the solvent‐dependant photochemical cleavage, and enhanced lability towards bases, are described, as well as UV‐kinetic measurements of the cleavage reaction. In addition, the incorporation of the (2‐nitrofluoren‐9‐yl)methoxycarbonyl group into two peptides, and a sequence‐dependant photochemical cleavage reaction are reported. Copyright © 2001 European Peptide Society and John Wiley &amp; Sons, Ltd.
Production, purification and some properties of Bac201, a bacteriocin-like inhibitory substance produced by Staphylococcus aureus AB201
2001-03-01

Staphylococcus aureus AB201, a clinical isolate from wound pus, produced a bacteriocin-like inhibitory substance termed as Bac201, that was inhibitory to Streptococcus agalactiae, Enterococcus faecalis, Acinetobacter calcoaceticus, Neisseria meningitidis and a number of staphylococcal species. It was purified to homogeneity by ammonium sulfate precipitation, gel filtration (BioSil-SEC-125), and reversed-phase high performance liquid chromatography (Vydac C4). The native Bac201 was sized at approximately 170-kDa as determined by GF HPLC. Fraction-I (native Bac201), having antibacterial activity was also examined by transmission electron microscopy and appeared as globular structure showing resemblance with phage-like objects. The purification of Bac201 resulted in 466-fold increase in specific activity and recovery of 0.94% of total antibacterial activity. The purified Bac201 migrated as single band on SDS-PAGE with an estimated molecular mass of about 41-kDa. Bac201 was sensitive to proteolytic enzymes, resistant to heat and organic solvents, and active over a wide range of pH (2.5–10). The amino acid composition revealed a general resemblance with other reported high molecular mass bacteriocins and predominance of glycine (39%), proline (13%) and alanine (8%) residues. Further results showed that Bac201 has a bactericidal effect on sensitive cells which is not produced by either cell lysis or apparent loss of membrane permeability.
Daytime variations in central nervous system activation measured by a pupillographic sleepiness test
2001-03-04

Pupil size is regulated exclusively by the autonomic nervous system, and in darkness is proportional to the level of central sympathetic tone. Spontaneous pupillary movements, while at rest in darkness and quiet, were recorded for a period of 11 min, using infrared video pupillography. Thirteen young adults took part in a 30‐h experiment lasting from 08.00 h to 14.00 h on the following day. Pupillographic testing and completion of a self‐rated scale for the estimate of sleepiness were repeated every two hours. Pupillary unrest index (PUI), as a measure of pupil size instability associated with daytime sleepiness, showed the lowest values at 09.00 h, when pupil size was found to be maximal, and 23.00 h. During the course of the day, amplitude spectrum ≤0.8 Hz and PUI showed increasing values during the afternoon hours, followed by a decrease during the evening. Daytime variations in the pupillary unrest index in healthy normal subjects were found to be positively correlated with the level of alertness. These findings are similar to the daytime variations found by the MSLT (multiple sleep latency test) in young adults.
The clinical relevance of an elevated lactate level after surgery for congenital heart disease
2001-03-06

Lactate is a product of anaerobic glycolysis, and may be increased due to inadequate oxygen supply, excessive oxygen demand, liver failure or exogenous supply with blood products. Children after cardiothoracic operations may therefore be at risk for elevated lactate concentrations. We examined the impact of elevated lactate levels on postoperative outcome.
ChemInform Abstract: Synthesis and Properties of Some 2,3‐Disubstituted 6‐Fluoro‐7‐(4‐methyl‐1‐piperazinyl)quinoxalines.
2001-03-06

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Comparative study of protein tyrosine phosphatase-ɛ isoforms: membrane localization confers specificity in cellular signalling
2001-03-08

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) ε on tyrosine kinase signalling in baby hamster kidney (BHK) cells overexpressing the insulin receptor (BHK-IR). The efficiency by which differently localized PTPε and PTPα 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 cytPTPε to the plasma membrane via the Lck-tyrosine kinase dual acylation motif restored high rescue efficiency and abolished the need for high cytPTPε levels. Consistent with these results, expression levels and subcellular localization of PTPε were also found to determine the phosphorylation level of cellular proteins including focal adhesion kinase (FAK). Furthermore, PTPε stabilized binding of phosphorylated FAK to Src, suggesting this complex as a possible mediator of the PTPε 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 PTPε may provide a molecular mechanism that determines PTPε substrate selectivity and isoform-specific function.
Modification of Slow Cortical Potentials in Patients with Refractory Epilepsy: A Controlled Outcome Study
2001-03-09

Summary: Purpose: To compare self‐regulation of low‐frequency EEG components (slow cortical potentials, SCPs) with other methods of seizure control for patients with drug‐refractory partial epilepsy and to separate the real anticonvulsive effect from placebo effects. Methods: Results of a treatment program of SCP self‐regulation (experimental group) are compared with two groups of patients, one of which learned self‐control of respiratory parameters (end‐tidal CO 2 and respiration rate: RES group); the other received medication with new anticonvulsive drugs (AEDs) in combination with psychosocial counseling (MED group). Clinical, cognitive, behavioral, and personality measures were assessed before and after treatment. In addition, to control for placebo responses, patients repeatedly estimated their beliefs in the efficiency of the respective treatment, their satisfaction and expectations, and the quality of the relationship with their therapists. Results: SCP and MED groups showed a significant decrease of seizure frequency, but the RES group did not. Clear positive changes in the sociopsychological adjustment were obtained in all three groups, with the maximal improvement being attained in the RES group. Conclusions: All kinds of therapy result in considerable improvement of patients' emotional state, which may in part be due to potential placebo effects; however, this improvement is not related to the quality of the therapeutic effect proper (i.e., seizure reduction). Traditional double‐blind control group designs are inappropriate for behavioral interventions or treatments with psychoactive pharmacologic drugs. Rather, specific tests can be developed to control the placebo effect and to separate it from the genuine therapeutic effects.