bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Impact of Povidone‐Iodine Pocket Irrigation Use on Pacemaker and Defibrillator Infections
Authors: LAKKIREDDY DHANUNJAYA , VALASAREDDI SRILAXMI , RYSCHON KAY , BASARKODU KRISHNAMOHAN , ROVANG KAREN , MOHIUDDIN SYED M. , HEE TOM , SCHWEIKERT ROBERT , TCHOU PATRICK , WILKOFF BRUCE , NATALE ANDREA , LI HUAGUI 
Published: August 2005

Background: Infection is a devastating complication of permanent pacemakers (PMs) implantable cardioverter defibrillators (ICDs). Many implanting physicians commonly use povidone‐iodine solution to irrigate the device pocket before implanting the device. We sought to assess if such a measure would alter the rate of infection.
Methods: A total of 2,564 consecutive patients who received implantable PM or ICD devices between 1994 and 2002 were studied. Povidone‐iodine was used for pocket irrigation in 53% and saline in 47%. A total of 18 (0.7%) patients developed pocket infections with 0.7% (10/1,359) in povidone‐iodine (group I) and 0.6% (8/1,205) in saline (group II) pocket irrigation (p = ns). Groups I and II were studied for various clinical and demographic variables described in the results section.
Results: There was no statistical difference in the baseline demographic and clinical characteristics between groups I and II, respectively. ICDs were most frequently infected than PMs (56% vs 44%). Most (83%) of the devices were dual chamber. Reopening of the pocket for either lead or generator replacement had a higher incidence of infection than new implants (61% vs 39%). There was no difference in the use of preimplantation antibiotic prophylaxis. Late (61%) and deep pocket infections (78%) were more common than early (39%) and superficial infections (22%). Blood cultures were positive in 67% and Staphylococcus aureus was the common most pathogen (50%). The mean duration of antibiotics use after the diagnosis of device infection was 35 ± 23 days with 72% requiring device explantation. The device was reimplanted on the contralateral side in 56% cases. One patient in each group died due to device infection and related complications. No significant allergy to iodine was seen in either group.
Conclusion: Povidone‐iodine irrigation of the subcutaneous pocket did not alter the rates of pocket infection after pacemaker/defibrillator implantation.
Clinical and Quality of Life Comparison of Accelerometer, Piezoelectric Crystal, and Blended Sensors in DDDR‐Paced Patients with Sinus Node Dysfunction in the Mode Selection Trial (MOST)
Authors: SHUKLA HIMANSHU H. , FLAKER GREG C. , HELLKAMP ANNE S. , JAMES ERSKINE A. , LEE KERRY L. , GOLDMAN LEE , ORAV E. JOHN , LAMAS GERVASIO A. 
Published: August 2005

Introduction: Permanent pacemakers are capable of increasing heart rate in response to physical activity by a variety of sensors including accelerometers, piezoelectric crystals, or blended sensors. The impact of these different physiologic sensors on cardiovascular events and quality of life is not known.
Methods: Of 2,010 patients randomized in the Mode Selection Trial, 1,245 patients were selected with the most commonly used pacemakers with these three sensors. Clinical characteristics and quality of life were compared between groups at baseline, 3 months, and then yearly.
Results: There were 449 patients with an accelerometer sensor device, 682 with a piezoelectric sensor, and 114 with a blended sensor. The groups were similar in terms of age (mean 74 years), gender, and cardiac risk factors but differences existed in weight, heart rate, mitral regurgitation, revascularization history, and drug therapy. The median ventricular pacing frequency was 80% (25th, 75th percentiles 42, 97). After a median follow‐up of 33.1 months, the risk of death, heart failure hospitalization, atrial fibrillation, and the combined endpoint of mortality and stroke was not significantly different between the sensor types, after adjustment for baseline differences. Quality of life analyses demonstrated that patients with blended sensors had significantly worse (P < 0.01) physical function than did patients with the other two sensor systems. Moreover, patients receiving blended sensors had the poorest absolute scores, without reaching statistical significance, on 9 of 13 quality of life measures after adjusting for differences in the groups.
Conclusion: We found no significant differences among the three most utilized sensors in clinical endpoints. Those patients who received blended sensors had worse physical function quality of life scores. However, clinical selection of the most sophisticated sensor for the most ill patients cannot be excluded as an explanation of these results.
Heterochromatin differentiation shows the pathways of karyotypic evolution in Israeli mole rats (<i>Spalax</i>, Spalacidae, Rodentia)
Authors: Ivanitskaya E. , Belyayev A. , Nevo E. 
Published: August 2005

C-banding, base-specific fluorochrome staining (CMA<sub>3</sub>/DA/DAPI), and comparative genomic hybridization (CGH) were used to analyze the constitutive heterochromatin in two Israeli <i>Spalax</i> species<i>, S. galili</i> (2n = 52) and <i>S. judai</i> (2n = 60). It was shown that C-positive centromeric heterochromatin and some telomeric sites comprise GC-rich DNA sequences in both species. Comparative genomic in situ hybridization revealed slight qualitative differences in highly repetitive sequences in the two <i>Spalax</i> species. Eight acrocentric pairs in <i>S. judai</i> that are involved in Robertsonian rearrangements, possessed composite heterochromatin with a preference of <i>S. judai</i> highly repetitive sequences in the proximal region. Heterochromatin of the sex chromosomes, two biarmed homologous pairs (4 and 5) in both species, and acrocentric chromosomes from the group with a variable centromere position in <i>S. judai</i> was entirely species-specific. The high level of homology in the composition of heterochromatin may relate to the recent divergence of Israeli <i>Spalax</i>. Interspecies heterochromatin differences are discussed in the context of possible mechanisms in the <i>Spalax</i> chromosome evolution.
Tyrosine phosphorylation and the small GTPase rac cross-talk in regulation of endothelial barrier function
Authors: Seebach Jochen , Mädler Hans-Jürgen , Wojciak-Stothard Beata , Schnittler Hans-Joachim 
Published: August 2005

SummaryEndothelial barrier function depends on the integrity of intercellular adherens junctions controlled by the association of VEcadherin/ catenin complex with cortical actin filaments. Both tyrosine phosphorylation/dephosphorylation of junctional proteins and actin reorganization mediated by rho-GTPases regulate barrier function but the relationship between these regulatory mechanisms is unclear. Here we studied the effects of factors increasing protein tyrosine phosphorylation, pervanadate (PV) and VEGF, on distribution of VE-cadherin, F-actin polymerization and transendothelial electrical resistance (TER) in human umbilical vein endothelial cells (HUVECs). Changes in protein tyrosine phosphorylation of cytoplasmic and junctional proteins, as well as the activity of rho-GTPase rac1, were also measured. We report for the first time that PV and VEGF induced a rapid transient increase in endothelial barrier function accompanied by rac1 activation, a differentiated tyrosine phosphorylation of theVE-cadherin/catenin complex, recruitment of actin filament to cell junctions and ruffle formation. A sustained decrease in endothelial barrier function was observed at later times of PV and VEGF treatment. Expression of dominant negative rac1, N17rac1 abolished the barrier-enhancing effects of PV andVEGF, while the sustained decrease in barrier function was unaffected. These observations bring into focus early shortterm effects of protein tyrosine phosphorylation in cells, often overshadowed by more pronounced and long-lasting later effects and may play an important role in the regulation of endothelial barrier function.
Clopidogrel inhibits platelet-leukocyte adhesion and plateletdependent leukocyte activation
Authors: Manarini Stefano , Dell’Elba Giuseppe , Martelli Nicola , Napoleone Emanuela , Santo Angelomaria Di , Savi Pierre , Lorenzet Roberto , Evangelista Virgilio 
Published: August 2005

SummaryClopidogrel is considered to be an important therapeutic advance in anti-platelet therapy. We investigated whether inhibition by clopidogrel results in a reduced capacity of platelets to adhere and stimulate pro-atherothrombotic and inflammatory functions in polymorphonuclear leukocytes (PMN) and in monocytes (MN). An eventual effect on these processes could further substantiate anti-atherothrombotic properties of this drug. The effects of clopidogrel or of its active metabolite were investigated on ADP or thrombin receptor-induced platelet activation and on platelet-leukocyte interactions ex vivo in the mouse or in vitro in isolated human cells or whole blood, respectively. Clopidogrel inhibited platelet aggregation, expression of P-selectin, platelet-PMN adhesion and platelet-dependent ROS production in mouse PMN. Similarly pretreatment of human platelets with the active metabolite of clopidogrel in vitro resulted in a profound inhibition of platelet P-selectin expression, platelet-PMN adhesion and production of ROS by PMN. Pretreatment with the active metabolite of clopidogrel significantly impaired the ability of platelets to up-regulate the expression of TF procoagulant activity in MN, in a washed cell system. Moreover, the active metabolite of clopidogrel inhibited rapidTF exposure on platelet as well as on leukocyte surfaces in whole blood. By reducing platelet-dependent up-regulation of inflammatory and pro-atherothrombotic functions in leukocytes, clopidogrel may reduce inflammation that underlies the chronic process of atherosclerosis and its acute complications.
Rates of proximal deep vein thrombosis as assessed by compression ultrasonography in patients receiving prolonged thromboprophylaxis with low molecular weight heparin after major orthopedic surgery
Authors: Hesselschwerdt Hans-Jürgen , Dieter Paar W. , von Hanstein Karl-Ludwig , Schellong Sebastian 
Published: August 2005

SummaryPatients undergoing major orthopedic surgery are at an increased risk of thromboembolism even after the acute postoperative phase. Therefore, prolonged thromboprophylaxis is currently recommended and widely used. The length of hospital stay after major orthopedic surgery is steadily decreasing and most patients are transferred to specialized rehabilitation centers in the early postoperative phase. Consequently, thromboprophylaxis is usually given during the rehabilitation period. Previously there have been no systematic studies of how many patients with asymptomatic thrombosis are transferred to a rehabilitation center or how many patients develop deep vein thrombosis (DVT) during rehabilitation. In the present study, 238 patients who had undergone major orthopedic surgery were examined by compression ultrasonography on day 1 or 2 and on day 20 of their rehabilitation phase in order to detect asymptomatic proximal DVT. Sonograms were read centrally with blinding to the clinical course of the patients. All patients received standard thromboprophylaxis during the acute postoperative phase. Prolonged thromboprophylaxis with enoxaparin was given during the rehabilitation phase. The mean duration of thromboprophylaxis was 36.8 days. At admission to the rehabilitation center, proximal DVT was identified in 16 patients (6.7%). New proximal DVT at discharge from the rehabilitation center was identified in 3.2% of patients following prolonged thromboprophylaxis with enoxaparin. In conclusion, a considerable percentage of patients with asymptomatic proximal DVT are transferred to rehabilitation centers following major orthopedic surgery. Using prolonged thromboprophylaxis, new proximal DVTs will still develop during rehabilitation, but at a low rate.
Generation of genetically-altered mice producing very low levels of coagulation factor VII
Authors: Xu Haifeng , Liang Zhong , Martin J. Andrew , Suckow Mark , Castellino Francis J. , Rosen Elliot D. 
Published: August 2005

SummaryIt has been shown earlier that mice with a total targeted deletion of the factorVII gene (FVII-/-) die perinatally, thereby precluding study of adult animals with this total deficiency. Consequently, mice producing very low levels of FVII were developed by targeted replacement of the wild-type (WT) murine FVII gene with its corresponding cDNA, under control of the tetracycline transactivator (tTA) promoter. When backcrossed into the C57Bl/6 strain, unchallenged mice containing two replaced FVIItTA alleles (FVIItTA/tTA) produce approximately 0.7% of WT FVII levels, but yet live to adulthood despite displaying severely downregulated overall thrombin production and spontaneously developing cardiac fibrosis at a young adult age. This genetically- altered mouse line provides an excellent animal model to study consequences of a severe FVII deficiency in unchallenged mice and in mice subjected to a variety of experimental challenges.
The Impact of Ice Crystal Shapes, Size Distributions, and Spatial Structures of Cirrus Clouds on Solar Radiative Fluxes
Authors: Schlimme I. , Macke A. , Reichardt J. 
Published: August 2005

AbstractThe solar radiative properties of cirrus clouds depend on ice particle shape, size, and orientation, as well as on the spatial cloud structure. Radiation schemes in atmospheric circulation models rely on estimates of cloud optical thickness only. In the present work, a Monte Carlo radiative transfer code is applied to various cirrus cloud scenarios to obtain the radiative response of uncertainties in the above-mentioned microphysical and spatial cloud properties (except orientation). First, plane-parallel homogeneous (0D) clouds with different crystal shapes (hexagonal columns, irregular polycrystals) and 114 different size distributions have been considered. The resulting variabilities in the solar radiative fluxes are in the order of a few percent for the reflected and about 1% for the diffusely transmitted fluxes. Largest variabilities in the order of 10% to 30% are found for the solar broadband absorptance. However, these variabilities are smaller than the flux differences caused by the choice of ice particle geometries.The influence of cloud inhomogeneities on the radiative fluxes has been examined with the help of time series of Raman lidar extinction coefficient profiles as input for the radiative transfer calculations. Significant differences between results for inhomogeneous and plane-parallel clouds were found. These differences are in the same order of magnitude as those arising from using extremely different crystal shapes for the radiative transfer calculations. From this sensitivity study, the ranking of cirrus cloud properties according to their importance in solar broadband radiative transfer is optical thickness, ice crystal shape, ice particle size, and spatial structure.
The Accuracy of Determining Three-Dimensional Radiative Transfer Effects in Cumulus Clouds Using Ground-Based Profiling Instruments
Authors: Pincus Robert , Hannay Cécile , Evans K. Franklin 
Published: August 2005

Abstract
Three-dimensional radiative transfer calculations are accurate, though computationally expensive, if the spatial distribution of cloud properties is known. The difference between these calculations and those using the much less expensive independent column approximation is called the 3D radiative transfer effect. Assessing the magnitude of this effect in the real atmosphere requires that many realistic cloud fields be obtained, and profiling instruments such as ground-based radars may provide the best long-term observations of cloud structure. Cloud morphology can be inferred from a time series of vertical profiles obtained from profilers by converting time to horizontal distance with an advection velocity, although this restricts variability to two dimensions. This paper assesses the accuracy of estimates of the 3D effect in shallow cumulus clouds when cloud structure is inferred in this way. Large-eddy simulations provide full three-dimensional, time-evolving cloud fields, which are sampled every 10 s to provide a “radar’s eye view” of the same cloud fields. The 3D effect for shortwave surface fluxes is computed for both sets of fields using a broadband Monte Carlo radiative transfer model, and intermediate calculations are made to identify reasons why estimates of the 3D effect differ in these fields. The magnitude of the 3D effect is systematically underestimated in the two-dimensional cloud fields because there are fewer cloud edges that cause the effect, while the random error in hourly estimates is driven by the limited sample observed by the profiling instrument.
The Relative Importance of Scavenging, Oxidation, and Ice-Phase Processes in the Production and Wet Deposition of Sulfate
Authors: Spiridonov Vlado , Curic Mladjen 
Published: August 2005

Abstract
The relative importance of various processes to sulfate production and wet deposition is examined by using a cloud-resolving model coupled with a sulfate chemistry submodel. Results using different versions of the model are then compared and principal differences with respect to their dynamics, microphysics, and chemistry are carefully discussed. The results imply that the dominant microphysical and chemical conversions of sulfate in the 3D run are nucleation, scavenging, and oxidation. Due to the lower cloud water and rainwater pH, oxidation does not contribute as significantly to the sulfate mass in the 2D run as the 3D.
Sensitivity tests have revealed that in-cloud scavenging in the 2D run for continental nonpolluted and continental polluted clouds accounted for 29.4% and 31.5% of the total sulfur deposited, respectively. The 3D run shows a lower percentage contribution to sulfur deposition for about 28.2% and 29.6%. In addition, subcloud scavenging for the 2D run contributed about 32.7% and 38.2%. In-cloud oxidation in the 2D run accounted for about 24.5% to 30.4% of the total sulfur mass deposited. Subcloud oxidation contributed from 21.0% to 20.6% of the total sulfur mass removed by wet deposition. In-cloud oxidation for the 3D run shows slightly lower percentage values when compared to those from the 2D run. The relative contribution of subcloud oxidation for continental nonpolluted and polluted clouds exceeds those values in the 2D run by approximately 7% and 10%, respectively. Ignoring the ice phase and considering those types of convective clouds in the 2D run may lead to a higher value of the total sulfur mass removed by the wet deposition of about 33.9% to 39.2% for the continental nonpolluted and 36.2% to 45.6% for the continental polluted distributions relative to the base runs.
Parameterizing the Difference in Cloud Fraction Defined by Area and by Volume as Observed with Radar and Lidar
Authors: Brooks Malcolm E. , Hogan Robin J. , Illingworth Anthony J. 
Published: August 2005

Abstract
Most current general circulation models (GCMs) calculate radiative fluxes through partially cloudy grid boxes by weighting clear and cloudy fluxes by the fractional area of cloud cover (Ca), but most GCM cloud schemes calculate cloud fraction as the volume of the grid box that is filled with cloud (Cυ). In this paper, 1 yr of cloud radar and lidar observations from Chilbolton in southern England, are used to examine this discrepancy. With a vertical resolution of 300 m it is found that, on average, Ca is 20% greater than Cυ, and with a vertical resolution of 1 km, Ca is greater than Cυ by a factor of 2. The difference is around a factor of 2 larger for liquid water clouds than for ice clouds, and also increases with wind shear. Using Ca rather than Cυ, calculated on an operational model grid, increases the mean total cloud cover from 53% to 63%, and so is of similar importance to the cloud overlap assumption.
A simple parameterization, Ca = [1 + e(−f )(C−1υ − 1)]−1, is proposed to correct for this underestimate based on the observation that the observed relationship between the mean Ca and Cυ is symmetric about the line Ca = 1 − Cυ. The parameter f is a simple function of the horizontal (H) and vertical (V) grid-box dimensions, where for ice clouds f = 0.0880 V 0.7696 H−0.2254 and for liquid clouds f = 0.1635 V 0.6694 H−0.1882.
Implementing this simple parameterization, which excludes the effect of wind shear, on an independent 6-month dataset of cloud radar and lidar observations, accounts for the mean underestimate of Ca for all horizontal and vertical resolutions considered to within 3% of the observed Ca, and reduces the rms error for each individual box from typically 100% to approximately 30%. Small biases remain for both weakly and strongly sheared cases, but this is significantly reduced by incorporating a simple shear dependence in the calculation of the parameter f, which also slightly improves the overall performance of the parameterization for all of the resolutions considered.
Prediction Rules for Regime Changes and Length in a New Regime for the Lorenz Model
Authors: Yadav Rama Shankar , Dwivedi Suneet , Mittal Ashok Kumar 
Published: August 2005

AbstractDespite the widespread use of the Lorenz model as a conceptual model for predictability studies in meteorology, only Evans et al. seem to have studied the prediction of occurrence of regime changes and their duration. In this paper, simpler rules are presented for forecasting regime changes and their lengths, with near-perfect forecasting accuracy. It is found that when |x(t)| is greater than a critical value xc, the current regime will end after it completes the current orbit. Moreover, the length n of the new regime increases monotonically with the maximum value xm of |x(t)| in the previous regime. A best-fit cubic expression provides a very good estimate of n for the next regime, given xm for the previous regime.Similar forecasting rules are also obtained for regime changes in the forced Lorenz model. This model was introduced by Palmer and used as a conceptual model to explore the effects of sea surface temperature on seasonal mean rainfall. It was found that for the forced Lorenz model, the critical value xc changed linearly with the forcing parameter providing bias to one of the regimes. Similar regime prediction rules have been found in some other two-regime attractors. It seems these forecasting rules are a generic property of a large class of two-regime attractors. Although as a conceptual model, the Lorenz model cannot be taken very literally, these results suggest a relationship between magnitudes of maximum anomaly in one regime, for example, the active spell, and duration of the subsequent break spell.