julilili42/papers huggingface dataset:
Enhanced Detection Criteria in Implantable Cardioverter Defibrillators: Sensitivity and Specificity of the Stability Algorithm at Different Heart Rates
2001-09-01

KETTERING, K., et al. : Enhanced Detection Criteria in Implantable Cardioverter Defibrillators: Sensitivity and Specificity of the Stability Algorithm at Different Heart Rates. Sensitivity and Specificity of the Stability Algorithm at Different Heart Rates. The lack of specificity in the detection of ventricular tachyarrhythmias remains a major clinical problem in the therapy with ICDs. The stability criterion has been shown to be useful in discriminating ventricular tachyarrhythmias characterized by a small variation in cycle lengths from AF with rapid ventricular response presenting a higher degree of variability of RR intervals. But RR variability decreases with increasing heart rate during AF. Therefore, the aim of the study was to determine if the sensitivity and specificity of the STABILITY algorithm for spontaneous tachyarrhythmias is related to ventricular rate. Forty‐two patients who had received an ICD (CPI Ventak Mini I, II, III or Ventak AV) were enrolled in the study. Two hundred ninety‐eight episodes of AF with rapid ventricular response and 817 episodes of ventricular tachyarrhythmias were analyzed. Sensitivity and specificity in the detection of ventricular tachyarrhythmias were calculated at different heart rates. When a stability value of 30 ms was programmed the result was a sensitivity of 82.7% and a specificity of 91.4% in the detection of slow ventricular tachyarrhythmias (heart rate &lt; 150 beats/min). When faster ventricular tachyarrhythmias with rates between 150 and 169 beats/min (170–189 beats/min) were analyzed, a stability value of 30 ms provided a sensitivity of 94.5% (94.7%) and a specificity of 76.5% (54.0%). For arrhythmia episodes ≥ 190 beats/min, the same stability value resulted in a sensitivity of 78.2% and a specificity of 41.0%. Even when other stability values were taken into consideration, no acceptable sensitivity/specificity values could be obtained in this subgroup. RR variability decreases with increasing heart rate during AF while RR variability remains almost constant at different cycle lengths during ventricular tachyarrhythmias. Thus, acceptable performance of the STABILITY algorithm appears to be limited to ventricular rate zones &lt; 170 beats/min.
Detailed analysis of successive pTRMs carried by pyrrhotite in Himalayan metacarbonates: an example from Hidden Valley, Central Nepal
2001-09-01

Low-grade metacarbonates from the Tethyan Himalaya were sampled for palaeomagnetic studies in Hidden Valley (Central Nepal). The remanence is carried by pyrrhotite, evidenced by thermomagnetic runs of susceptibility (Hopkinson peak at ∼300°C), alternating field demagnetization, isothermal remanent magnetization acquisition and subsequent thermal demagnetization. The palaeomagnetic directions reflect a Tertiary overprint after the main folding event, probably synchronous with the metamorphism. Normal and reverse remanence directions were separated and vary with altitude. It is also possible to retrieve several antiparallel components versus temperature during thermal demagnetization of a single sample. At higher altitudes (4920–5500 m), the first component recorded is reverse ( R1). At a lower temperature a normal component can be extracted ( N1). For sites sampled at lower altitudes (4700–4900 m), the high-temperature reverse component disappears but a medium-temperature reverse component ( R2) demagnetized in a narrow temperature range can be identified in between two normal components ( N1 at high temperature and N2 at low temperature). At the lowest altitudes (4450–4700 m), only a normal component ( N2) appears. The occurrence of successive normal and reverse polarities in one sample is interpreted as the record of successive reversals of the geomagnetic field during the post-metamorphic Tertiary cooling of the studied area. The polarity versus altitude function is a powerful argument for a thermomagnetic origin of the magnetization. No obvious rotations around a vertical axis with respect to the stable Indian plate are evidenced for the Tertiary. However, the inclination is not consistent with the expected inclination. Main Central Thrust ramping can be invoked to explain our observations. R1, N1 and N2 inclinations are slightly different and their tendency is consistent with tilting towards the north during magnetization acquisition. The minimum total amount of such tilting is around 25°. Accurate geochronological data from the Tethyan Himalaya would be of a great help for better resolution.
Decontaminated Single-Use Devices: An Oxymoron That May Be Placing Patients at Risk for Cross-Contamination
2001-09-01

Abstract Objective: To determine whether reprocessed single-use devices would meet regulatory standards for sterility and meet the same materials standards as a new device. Design: The study included single-use and reusable biopsy forceps and papillotomes and a reusable stone retrieval basket. The suitability of these devices for cleaning and disinfection or sterilization was examined. Methods: Testing of cleanability was conducted on devices contaminated with technetium 99-radiolabeled human blood. Instruments were cleaned using hospital recommended practices for manual cleaning. Gamma counts per second were determined before and after cleaning to localize contaminants, which were additionally visualized using light and scanning electron microscopy. X-ray phc-toelectron spectroscopy was used to quantify contamination elements on the materials tested. Residual bioburden testing on instruments contaminated with microorganisms suspended in coagulable sheep blood was carried out to establish the efficacy of disinfection and sterilization. Results: All devices remained contaminated after cleaning, but single-use devices and the stone basket tended to be more heavily contaminated than reusable forceps and papillotomes. Cleaning procedures facilitated distribution of contaminants further into the lumens of the disposable forceps. Decreased concentrations of silicon and increased concentrations of carbon and nitrogen suggested that layers of silicon lubricant had been removed and contaminants were organic material. Reusable devices were effectively disinfected, but single-use devices were not Sterilization could not eliminate the challenge microorganisms completely. Conclusions: None of the reprocessed single-use instruments were effectively cleaned, disinfected, or sterilized. This condition may provide an opportunity for the viability of non-resistant or nosocomial organisms and viruses. Additionally, reprocessing procedures may result in material destruction of fragile devices. Cost-saving initiatives that have inspired reprocessing of single-use devices, despite the absence of data establishing the efficacy of decontamination and the durability of materials throughout reprocessing, should be pushed into the background.
Combined benefits of annual mass treatment with ivermectin and cattle zooprophylaxis on the severity of human onchocerciasis in northern Cameroon
2001-09-01

We studied the effect of 10 annual distributions of ivermectin for control of human onchocerciasis on the reduction of Onchocerca volvulus transmission by Simulium vector flies. Prevalence and infection load in the human population decreased, whilst the annual biting rates (ABR) of the vector remained unchanged. The annual transmission potential of infective larvae of O. volvulus fell to 40% of the pre‐intervention level, but was still sufficient to maintain endemicity. However, recent immigration of herds of nomadic cattle into the study area has diverted the flies from man to cattle, creating an additional zooprophylactic effect. The predominant transmission of the bovine filaria O. ochengi to man also provides some concomitant cross‐protective immunity against further infestations with O. volvulus . The effects of ivermectin on O. volvulus , combined with the zooprophylactic effects of the increased cattle population, have produced a complex beneficial influence on the transmission of human onchocerciasis.
Methods of experimental and clinical assessment of the relative measurement accuracy of an intracranial pressure transducer
2001-09-01

✓ The assessment of the actual measurement accuracy of an intracranial pressure (ICP) transducer is imperative but still very difficult in practice. The authors tested the Codman MicroSensor ICP transducer experimentally. Additionally, a bedside test for assessment of measurement accuracy was used before and after clinical monitoring. For laboratory testing, seven new transducers were examined for measurement accuracy at increasing pressures ranging from 0 to 75 mm Hg. Drift was evaluated for 10 days at six different pressure levels ranging from 0 to 50 mm Hg. Temperature drift was assessed over a temperature range from 20 to 45°C. The percentage absolute difference was used in the assessment of measurement accuracy. For clinical testing, measurement accuracy was assessed intraoperatively just before the insertion of the transducer and in an open water bath after its explantation, at 10 cm H 2 O both times. The maximum percentage absolute difference was 9% at a pressure of 10 mm Hg, and declined toward 2.3% at a pressure of 75 mm Hg. The maximum drift over 10 days was −4 mm Hg. Within the range of 30 to 40°C, temperature drift was negligible. Over a period of 2 years, between June 1997 and June 1999, 40 ICP transducers were implanted in 35 patients by one surgeon. Of these devices, a malfunction was detected in two of them by testing them in a water bath before insertion. Experimental and clinical results indicate that this miniature strain-gauge transducer measures accurately; however, control readings for the probe by means of measurement in an open water bath just before insertion are strongly recommended.
BeppoSAX spectroscopy of MR 2251-178: A test for ionized reflection in radio quiet QSOs
2001-09-01

\\n We present the 0.1-200 keV BeppoSAX spectrum of MR 2251-178\\nobserved at two epochs in 1998 separated by 5 months.\\nBoth epochs show identical spectral shape and X-ray flux. \\nAnalysis of the combined spectra allow us to\\nconfirm the presence of the ionized Fe Kα line\\ndetected by ASCA and to test the presence of \\nreflection from ionized material. \\n The best self-consistent spectral fit is obtained when including a \\ncontribution from a mildly ionized reflector \\n( erg cm s-1, i.e. ) \\nwith a reflection fraction\\n . \\nAn exponential cut-off to the direct power-law continuum is \\nthen required at keV.\\nThe low energy spectrum is absorbed by ionized matter\\nwith a column density cm-2 and an X-ray ionization parameter \\n .\\nThe warm absorber column is slightly lower\\nthan that measured with ASCA. This change could be caused\\nby bulk motion. The BeppoSAX absorber ionization parameter globally\\nagrees with the "U versus Flux" correlation found for MR 2251-178 with \\nEXOSAT, Ginga and ASCA. This suggests that the\\nabsorber is in a state of instantaneous ionization equilibrium.\\n\\n\\n
Topology of the polypeptide chain in the complex of agglutinin from castor bean seeds with β-D-galactose in the crystalline state
2001-09-01

The three-dimensional structure of the complex of agglutinin from Ricinus communis with β-D-galactose was established and refined at 2.5 Å resolution by X-ray structure analysis. Biocrystals were obtained using dialysis through a semipermeable membrane. X-ray intensity data (R merge = 4.6%) were collected from one crystal at 100 K using synchrotron radiation at the DESY outstation [European Molecular Biology Laboratory (EMBL), Hamburg, Germany]. The initial phases were calculated by the molecular replacement method. The atoms of both protein and sugar molecules were localized. Unlike ricin, the ricinlike heterodimer RcA contains only one galactose-binding center in the region of the Asn46-Gly25-Trp37-Lys40 site in the first domain of the B subunit, whereas the second galactose-binding site of the B subunit is lost. One functionally important water molecule, which is bound to the residues Tyr123-Glu176-Arg179-Glu207, was revealed in the region of the active center in the A subunit.
Phase diagram of hole-doped high-Tc superconductors: Effects of Cooper-pair phase fluctuations within fluctuation-exchange theory
2001-09-01

Using the Hubbard model Hamiltonian we study spin-fluctuation exchange-induced superconductivity of d-wave symmetry. Results are presented for the characteristic temperature at which a gap appears in the spectral density, for at which Cooper-pairs are formed, for at which Cooper pairs become phase coherent, and for the superfluid density We find that, with increasing doping, for the phase coherence energy becomes larger than the Cooper-pair condensation energy. Accordingly, one has for and for the overdoped cuprates. We use our results to discuss dynamics and recent dynamical conductivity and ultrafast nonequilibrium measurements.
Arguments against one-boson-exchange models of nuclear forces and new mechanism for intermediate-and short-range nucleon-nucleon interaction
2001-09-01

Arguments against the traditional Yukawa-type approach to NN intermediate-and shortrange interaction due to scalar-isoscalar and heavy-meson exchanges are presented. Instead of the Yukawa mechanism for intermediate-range attraction, some new approach based on the formation of a symmetric six-quark bag in the state |(0s)6[6]X, L=0〉 dressed owing to strong coupling to π, σ, and ρ fields is suggested. This new mechanism offers a strong intermediate-range attraction, which replaces effective σ exchange (or excitation of two isobars in the intermediate state) in traditional force models. A similar mechanism with the production of a vector ρ meson in the intermediate six-quark state is expected to lead to a strong short-range spin-orbit nonlocal interaction in the NN system, which may resolve the long-standing puzzle of the spin-orbit force in baryons and in two-baryon systems. The effective interaction in the NN channel provided by the new mechanism will be enhanced significantly if the partial restoration of chiral symmetry is assumed to occur inside the six-quark symmetric bag. A simple illustrative model is developed that demonstrates clearly how well the suggested new mechanism can reproduce NN data. Strong interrelations have been shown to exist between the proposed microscopic model and one-component Moscow NN potential developed by the authors previously and also with some hybrid models and the one-term separable Tabakin potential. The new implications of the proposed model for nuclear physics are discussed.
Acid-sensing ion channel (ASIC) 4 gene: physical mapping, genomic organisation, and evaluation as a candidate for paroxysmal dystonia
2001-09-01

Acid-sensing ion channels (ASICs) are protongated Na(+) channels. They have been implicated with synaptic transmission, pain perception as well as mechanoperception. ASIC4 is the most recent member of this gene family. It shows expression throughout the central nervous system with strongest expression in pituitary gland. ASIC4 is inactive by itself and its function is unknown. Mutations in ion channel subunits, which are homologues of ASICs lead to neurodegeneration in Caenorhabditis elegans. It has, therefore, been speculated that similar mutations in ASICs may be responsible for neurodegeneration in humans. Here, we show that ASIC4 maps to the long arm of chromosome 2 in close proximity to the locus for paroxysmal dystonic choreoathetosis (PDC), a movement disorder with unknown cause. Ion channel genes have been shown to cause several other paroxysmal neurologic disorders and are important candidate genes for PDC. We established the genomic organisation of the ASIC4 gene and screened a PDC pedigree for mutations in the coding region. Although we identified three polymorphisms in the Cterminal part of the ASIC4 protein, these were not present in each affected subject in the PDC kindred we analysed. Therefore, although the ASIC4 gene is physically mapped to the PDC locus, our data indicates that ASIC4 gene mutation is not the cause of PDC. It remains to be established if mutations in ASIC4 or other ASIC subunits may cause neurological disorders.
Group 12 Metal Complexes of 2-Formylpyrrole-(4PL1) and 2-Acetylpyrrole-N(4)-phenylthiosemicarbazone (4Pl2), as Examples form Different Donor Modes. Crystal and Molecular Structures of [Hg(4PL1- H)Br]2 and [Zn(4PL2)2Br2] · 2 EtOH
2001-09-01

Abstract The reactions of 4 N-phenyl-2-[ 1 -(pyrrol-2-yl)methylidene]-hydrazine carbothioamide (4PL 1 ) and 4 N-phenyl-2-[l-(pyrrol-2-yl)ethylidene]-hydrazine carbothioamide (4PL 2 ) with Group 12 metal halides afford complexes of types [M(L) 2 X 2 ] [M = Zn, L = 4PL 1 or 4PL 2 , X = Cl, Br or I; M = Cd, L = 4PL 1 , and X = Cl, or L = 4PL 2 and X = Cl, Br or I] and [M(L)X 2 ] [M = Cd, L = 4PL 1 , X = Br or I; M = Hg, L = 4PL 1 or 4PL 2 , X = Cl, Br or I]. The new compounds were characterized by elemental analysis, FAB mass spectrometry, IR spectroscopy, and, in the case of sufficiently soluble compounds, 1 H, 13 C and, when appropriate, 113 Cd or 199 Hg NMR spectrometry. The structures of [Hg(4PL 1 -H)Br] and [Zn(4PL 2 ) 2 Br 2 ] · 2 EtOH were also studied by single-crystal X-ray diffractometry. In [Hg(4PL 1 -H)Br] crystallized from the mother liquor of its synthesis, 4PL 1 behaves as a monodeprotonated S,N-bidentate ligand. Otherwise, with Hg(II), Zn(II) and Cd(II), 4PL 1 and 4PL 2 both behave as neutral S-monodentate ligands.
Gene Dosage Analysis in Silver-Russell Syndrome: Use of Quantitative Competitive PCR and Dual-Color FISH to Estimate the Frequency of Duplications in 7p11.2–p13
2001-09-01

Silver-Russell syndrome (SRS) describes a heterogeneous malformation syndrome mainly characterized by intrauterine and postnatal growth retardation (IUGR/PNGR). Approximately 10% of SRS cases have been associated with maternal uniparental disomy (matUPD) 7. This suggests the involvement of at least one imprinted gene on chromosome 7 in the pathogenesis of SRS. Additionally, two familial and one single SRS patients have been published with an interstitial duplication in 7p11.2-p13, including the genes GRB10 and IGFBP1; IGFBP3 was investigated in only one case revealing duplication; conversely, double gene dosage of EGFR was excluded in all 3 patients. Two further cytogenetically abnormal cases, one with a paracentric inversion (7)(p14p12) and one with matUPD7/partial trisomy for 7p13–q11, confirmed that the proximal short arm of chromosome represents an interesting region possibly harboring (a) candidate gene(s) for SRS. Although previously published investigations on the genes GRB10, IGFBP1, IGFBP3, and EGFR report neither disease-relevant mutations nor abnormal imprinting patterns, the SRS cases with chromosomal duplications suggest that variation of gene copy number might be a further type of mutation. To obtain meaningful results on the frequency of duplications in proximal 7p, we screened 32 SRS patients using quantitative PCR assays for GRB10, IGFBP1, IGFBP3, and EGFR. The data were confirmed by dual-color fluorescence in situ hybridization (FISH) of spot check samples. Results obtained by both methods exclude duplications in all analyzed patients and indicate an overall percentage of duplication among SRS patients between 2.4% (GRB10) and 5% (IGFBP1). By testing and evaluating quantitative competitive PCR for various loci, we developed a practical approach for gene dosage analysis which can be easily established for routine purposes.
Determination of the enantiomerization barrier of thalidomide by dynamic capillary electrokinetic chromatography
2001-09-01

Enantioselective chromatographic methods, representing the most commonly used techniques for the determination of enantiomeric ratios, can also be used for the evaluation of stereochemical integrity. In the present study, dynamic capillary electrokinetic chromatography (DEKC) was employed to determine the enantiomerization barrier of thalidomide. In the presence of the chiral mobile phase additive carboxymethyl-β-cyclodextrin, the interconverting enantiomers of thalidomide produced characteristic elution profiles exhibiting plateaus and/or peak broadening between 25 and 55°C at pH 8. To obtain the enantiomerization barrier of thalidomide from experimental data, the fast and efficient simulation program ChromWin was used to simulate the experimental interconversion profiles and to obtain the apparent rate constants k1app(T). Additionally, these values were compared with the novel approximation function for the direct calculation of enantiomerization barriers from chromatographic parameters of elution profiles. From the rate constants k1app(T) of temperature-dependent measurements the kinetic activation parameters ΔG(T)#,ΔH#, and ΔS# of the enantiomerization of thalidomide were obtained. At 25°C, the enantiomerization barrier ΔG#was determined to be 102±1 kJ/mol at pH 8 in the dynamic electrokinetic chromatographic experiment.
Transcatheter occlusion of a large coronary arterial fistula with new detachable platinum microcoils
2001-09-01

We report a 17 year old boy with a large fistula from the right coronary artery to the right ventricle. The fistula consisted of two major branches. The smaller branch could be embolised with three detachable platinum microcoils without problems. The high flow of blood in the larger branch, however, prevented conventional occlusion using coils. Interventional occlusion of this branch was achieved in a second attempt. Following creation of an arterio-venous wire-loop, we advanced a balloon catheter into the distal end of the fistula. Under temporary occlusion of the fistula, complete closure was achieved by delivery of 7 detachable platinum microcoils. Thus, even large coronary arterial fistulas can be closed safely with these new platinum detachable microcoils. The procedure, however, requires temporary control of the flow of blood by balloon occlusion.
Trifunctional Phosphane Ligands and Their Application in the Synthesis of Novel Cage-Structured Platinacyclophanes and Trinuclear Chain-Like Platinacycles by Self-Assembly
2001-09-01

The synthesis of the 1,3,5-tris[(diphenylphosphoryl)alkyl]benzenes 7−10 succeeds by reaction of the corresponding 1,3,5-tris(bromoalkyl)benzenes 3−6 with ethyl diphenylphosphinite in an Arbusov-type reaction. Reduction of these phosphane oxides leads to the trifunctional phosphane ligands 11−14. Their potency of self-assembly was examined by the employment of platinum(II) complex fragments. A five-component self-assembly consisting of 3 equiv. of the platinum complex Cl2Pt(NCPh)2 and 2 equiv. of the ligands 11−14 under high-dilution conditions led to the formation of the nanoscaled triplatinacyclophanes 1 and 15−17. Polymers were formed as by-products from the reactions between 11−13 and Cl2Pt(NCPh)2, whereas in the case of 14 three other platinacyles 18−20 with a chain-like structure were formed. The structures of the metallacycles 1 and 15−17 as well as 18−20 were elucidated by 31P{1H}, 13C{1H}, and 195Pt{1H} NMR spectroscopic investigations.
Fizeau interferometer for phase shifting interferometry in ultrahigh vacuum
2001-09-01

We describe a phase shifting interferometer which is based on a frequency-tunable diode laser in a Littrow configuration and is suitable for operation in ultrahigh vacuum. A wave front distortion measurement of a thin glass plate with a repeatability of λ/1000 is presented.