bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antegrade popliteal artery approach for the treatment of critical limb ischemia in patients with occluded superficial femoral arteries
Authors: Feiring Andrew J. , Wesolowski Amy A. 
Published: February 2007

AbstractTreating patients with critical limb ischemia (CLI) secondary to superficial femoral artery (SFA) occlusions and jeopardized tibial‐peroneal run‐off is challenging, especially when the SFA cannot be recanalized. These patients are frequently poor candidates for surgical revascularization and thus amputation is the therapy most often recommended. In this article, we describe a new technique for treating these patients, which combines antegrade popliteal arterial access with tibial arterial revascularization using drug eluting stents (DES). Five patients scheduled for below‐knee amputations were successfully treated using this endovascular approach. For the duration of follow‐up (29 ± 8 months), all patients remained free of death, amputation, or target lesion revascularization. ABI's post intervention demonstrated a modest improvement (ABI = 0.32 ± 0.09 vs. 0.58 ± 0.09 pre vs. post, P ≤≤≤ 0.01). Technical details and rationale for this approach are discussed. Thus, in a well defined subset of patients with recent onset CLI and SFA occlusion, antegrade popliteal DES supported angioplasty offers additional options for patients who might otherwise face amputation. © 2007 Wiley‐Liss, Inc.
Origin of all three major coronary arteries from the right sinus of Valsalva: Clinical, angiographic, and magnetic resonance imaging findings and incidence in a select referral population
Authors: Patel Kashyap B. , Gupta Himanshu , Nath Hrudaya , Aqel Raed A. , Zoghbi Gilbert J. , Soto Benigno , Perry Gilbert J. , Lloyd Steven G. 
Published: February 2007

AbstractObjective: We sought to determine the incidence and imaging features by coronary angiography and cardiac magnetic resonance imaging (MRI) of anomalies in which the right, circumflex, and left anterior descending coronary arteries arise separately from the right sinus of Valsalva. Background: The anomalous origin of all major coronary arteries from separate ostia in the right sinus of Valsalva has been reported as exceedingly rare, with mainly isolated cases reported. A knowledge of the origin and proximal courses of aberrant arteries is critical for patient management. Methods: 42 consecutive patients without other congenital heart disease referred to our institution for MRI evaluation of anomalous coronary artery over a six year period were evaluated. Analysis of angiograms and MRI was done to determine the anatomic origin and proximal pathway of coronary arteries (determined by conventional angiography and MRI) and degree of any stenosis (by angiography). Results: Seven of the 42 patients (17%) in this referral population had the described anatomy. Both conventional angiography and MRI depicted the origin and proximal courses of these arteries. In all patients, the circumflex passed behind the aorta. In three, the left anterior descending passed through the ventricular septum; in four, it passed anterior to the pulmonary trunk. Conclusions: This series is the largest ever reported on this complex anatomical variant and the first to give a systematic analysis of the anatomy by angiography and MRI. This constellation of multiple anomalous coronary arterial origins and proximal courses may not be as rare as previously reported. Published 2007 Wiley‐Liss, Inc.
Formation of Polymer and Nanoparticle Doped Polymer Minirods by Use of the Microsegmented Flow Principle
Authors: Groß G. A. , Hamann C. , Günther P. M. , Köhler J. M. 
Published: February 2007

AbstractThe microsegmented flow principle was applied for the preparation of polymer minirods. A microfluidic assembly was used to form monomer segments separated by an immiscible perfluorinated aliphatic solvent. These segments were transformed into polymer rods by thermal polymerization. Uniform‐sized polystyrene rods with various diameters and lengths were prepared in this way. The microfluidic geometry and polymerization conditions were tuned to obtain polymer rods of various lengths and diameters. Metal nanoparticle doped polystyrene polymer rods were obtained by thermal polymerization of appropriate nanoparticle/monomer mixtures. After polymerization, the polystyrene rods were colored by an azo coupling reaction.
Flow Boiling of n‐Hexane in Small Channels: Heat Transfer Measurements and Flow Pattern Observations
Authors: Cortina Díaz M. , Schmidt J. 
Published: February 2007

AbstractAn experimental investigation was conducted to study flow boiling heat transfer to n‐hexane. Two different test sections were employed: a single 0.3 · 12.7 mm2rectangular microchannel and a 0.5 mm concentric annulus of 6 mm inner diameter. Both test sections were electrically heated. The examined parameter ranges were: mass fluxes between 50 and 400 kg/(m2 s) and heat fluxes up to 106 kW/m2, at an outlet pressure of 0.1 MPa. Infrared thermography was employed to measure the outer wall temperatures of the rectangular channel and to determine the heat transfer coefficients. This measurement method was especially appropriate for the analysis of the transient behavior of boiling in microchannels, which has been often reported in the literature. In addition, flow visualization was carried out under comparable experimental conditions, using an inner heated circular annulus with a narrow gap.
Formation of Au/Ag Nanoparticles in a Two Step Micro Flow‐Through Process
Authors: Köhler J. M. , Held M. , Hübner U. , Wagner J. 
Published: February 2007

AbstractThe optical properties of metal nanoparticles depend strongly on their composition and size. The plasmon absorption band can be shifted between the blue range and the red range of the optical spectrum, if silver and gold are mixed and aggregation of particles is also induced. The formation of different nanoparticles and nanoparticle aggregates was studied in a two‐step flow‐through process using a glass/Si/glass static micromixer. The educt solution was pumped through the mixer chips by programmable syringe pumps. The process was monitored online by a compact spectrometer connected to the outlet tube by glass fibers. The product solution was collected and investigated by a UV/VIS spectrophotometer. Selected samples were investigated by Scanning Electron Microscopy (SEM) to evaluate the particle morphology. The typical Ag nanoparticle absorption was found, when an excess of Ag ions was introduced into the system. The intensity of the peak decreased when the flow rate of AgNO3 solution was reduced in a reaction system, which included HAuCl4 solution and polyvinyl alcohol, as well as the reducing agent (ascorbic acid). The experiments show that the educt concentration ratios as well as the total flow rates influence the shape and composition of the nanoparticles. Therefore, microreactors with fast mixing and well reproducible mixing conditions are interesting options for the synthesis of nanomaterials.
Designstudie eines kontinuierlichen Ultraschall‐Fällungsreaktors
Authors: Machunsky S. , Peuker U. A. 
Published: February 2007

AbstractDurchflussreaktoren werden für Fällungsreaktionen als Alternative zu den bisher verwendeten Rührkesselreaktoren gesehen. Der Einsatz von Ultraschall ermöglicht hier einen definierten, intensiven, lokal begrenzten Energieeintrag in den Verfahrensraum. Diese Reaktoren sind aber bisher wenig untersucht worden und damit am Markt nicht in optimierter Form erhältlich. Die hergestellten Partikel werden mittels Partikelgrößenanalyse charakterisiert. Der Effekt der Betriebsparameter Ultraschallleistung, Verweilzeit und Hilfswasserstrom auf die Partikelgröße wird herausgearbeitet. Weiterhin werden experimentelle Ergebnisse diskutiert, die sich auf das geometrische Design des Reaktionsraums konzentrieren. Dabei sind die Position des Ultraschallhorns, die Führung der Feed‐Ströme und die Strategie für die Bereitstellung des Stabilisierungsmittels von Interesse.
Zur Relevanz der Probenteilung für die Partikelgrößenanalyse
Authors: Teipel U. , Winter H. 
Published: February 2007

AbstractFür die Charakterisierung von Partikeln und dispersen Systemen ist es erforderlich, vor der Durchführung der Größenanalyse aus der vorhandenen Grundgesamtheit eine repräsentative Probe mittels systematischer Probenteilung zu erzeugen. In dieser Arbeit wird gezeigt, dass bei identischer Probennahmetechnik die Probenzuführung und die Beanspruchung des Kollektivs zur Erzeugung einer repräsentativen Probe aus der Grundgesamtheit einen entscheidenden Einfluss auf die Struktur der Probe nach der Teilung aufweist.
Polymorphisms of the neuronal and inducible nitric oxide synthase genes and the risk of cutaneous melanoma
Authors: Li Chunying , Hu Zhibin , Liu Zhensheng , Wang Li‐E , Gershenwald Jeffrey E. , Lee Jeffrey E. , Prieto Victor G. , Duvic Madeleine , Grimm Elizabeth A. , Wei Qingyi 
Published: February 2007

AbstractBACKGROUND.Nitric oxide (NO) is a multifunctional molecule that is produced by both neuronal NO synthase (nNOS) and inducible NO synthase (iNOS), and the expression of nNOS and iNOS is up‐regulated in various cancer cells, including cutaneous melanoma (CM). The authors hypothesized that selected functional single‐nucleotide polymorphisms (SNPs) in the nNOS and iNOS genes are associated with the risk of CM.METHODS.In a hospital‐based case‐control study of 602 non‐Hispanic white patients with CM and 603 matched, cancer‐free controls, the authors genotyped the nNOS −84 guanine‐to‐adenine (G→A), nNOS 276 cytosine‐to‐thymine (C→T), iNOS Ex16+14C→T, and iNOS 974G→T SNPs and assessed their associations with the risk of CM in multivariate logistic regression models.RESULTS.A significantly increased risk of CM was associated with the nNOS −84G→A (adjusted odds ratio [OR], 1.49; 95% confidence interval [95% CI], 1.05–2.13) and −84AG+AA (OR, 1.48; 95% CI, 1.06–2.06) genotypes compared with the nNOS −84GG genotype, but not with other nNOS or iNOS SNPs. In a combined analysis, an increased risk of CM was associated with the nNOS −84AA+AG/276CT+TT genotype (OR, 1.70; 95% CI, 1.05–2.76) and the nNOS −84AA+AG/276CC genotype (OR, 1.70; 95% CI, 1.08–2.68) compared with the nNOS −84GG/276CT+TT genotypes. No altered risk of CM was associated with iNOS genotypes. In addition, there was statistical evidence of interaction of nNOS SNPs with having moles (P = .002) and sunburns (P = .017).CONCLUSIONS.Genetic variants of nNOS, but not iNOS, may be biomarkers for susceptibility to CM, and the risk of CM associated with sunburns and moles may be modulated by nNOS variant genotypes. Cancer 2007. © 2007 American Cancer Society.
Protein–Protein Interactions in Complex Cosolvent Solutions
Authors: Javid Nadeem , Vogtt Karsten , Krywka Chris , Tolan Metin , Winter Roland 
Published: February 2007

AbstractThe effects of various kosmotropic and chaotropic cosolvents and salts on the intermolecular interaction potential of positively charged lysozyme is evaluated at varying protein concentrations by using synchrotron small‐angle X‐ray scattering in combination with liquid‐state theoretical approaches. The experimentally derived static structure factors S(Q) obtained without and with added cosolvents and salts are analysed with a statistical mechanical model based on the Derjaguin–Landau–Verwey–Overbeek (DLVO) potential, which accounts for repulsive and attractive interactions between the protein molecules. Different cosolvents and salts influence the interactions between protein molecules differently as a result of changes in the hydration level or solvation, in charge screening, specific adsorption of the additives at the protein surface, or increased hydrophobic interactions. Intermolecular interaction effects are significant above protein concentrations of 1 wt %, and with increasing protein concentration, the repulsive nature of the intermolecular pair potential V(r) increases markedly. Kosmotropic cosolvents like glycerol and sucrose exhibit strong concentration‐dependent effects on the interaction potential, leading to an increase of repulsive forces between the protein molecules at low to medium high osmolyte concentrations. Addition of trifluoroethanol exhibits a multiphasic effect on V(r) when changing its concentration. Salts like sodium chloride and potassium sulfate exhibit strong concentration‐dependent changes of the interaction potential due to charge screening of the positively charged protein molecules. Guanidinium chloride (GdmCl) at low concentrations exhibits a similar charge‐screening effect, resulting in increased attractive interactions between the protein molecules. At higher GdmCl concentrations, V(r) becomes more repulsive in nature due to the presence of high concentrations of Gdm+ ions binding to the protein molecules. Our findings also imply that in calculations of thermodynamic properties of proteins in solution and cosolvent mixtures, activity coefficients may not generally be neglected in the concentration range above 1 wt % protein.
The dyslexic student and mathematics in higher education
Authors: Perkin Glynis , Croft Tony 
Published: February 2007

AbstractDifficulties that are encountered by dyslexic undergraduates with their learning and understanding of mathematics are explored. Specific consideration is given to issues arising through mathematical content, its delivery, the procedures and processes of ‘doing’ mathematics, and its assessment. Particular difficulties, which have emerged through exploratory and explanatory multiple‐case studies, and witnessed through the provision of one‐to‐one support to a dyslexic and dyspraxic engineering undergraduate, are detailed. Recommendations for the provision of mathematical support to dyslexic students and proposals for future research are given. Copyright © 2007 John Wiley & Sons, Ltd.
Escape of TA3 tumors from allogeneic immune rejection: theory and experiments
Authors: Nowotny A. , Grohsman J. , Abdelnoor A. , Rote N. , Yang Cynara , Waltersdorff R. 
Published: February 2007

AbstractA factor promoting tumor growth in allogeneic mice was found in the ascites fluid of TA3‐Ha tumor‐bearing mice. Preliminary attempts to isolate this factor resulted in a preparation (P3), devoid of free immunoglobulins or serum proteins, which had enhanced action in promoting tumor growth in vivo. Electron microscopy showed that the P3 preparation is of membranous origin. Biochemical assays for membrane marker enzymes were positive. 5′ ‐Nucleotidase and alkaline α‐glycerophosphatase activity was found. Chemical and gas‐liquid chromatographic analysis of long‐chain carboxylic acids present in the tumor cell membrane and in the P3 revealed the presence of fatty acids in almost identical ratios in both preparations, again indicating the membranous character of P3.The P3 preparation as well as the ascites fluid have immunogenic properties. They could induce immune tolerance if injected neonatally and the P3 preparation could immunize against the TA3‐Ha tumor if injected intramuscularly or subcutaneously into adult mice. It had no effect if injected intravenously.In vitro studies of the mode of action of the tumor growth facilitating component indicate that it acts through reaction with immunocytes. A cytotoxic effect of ascites fluid on normal thymocytes in the presence of added complement could be demonstrated. Exposure of immune spleen cells to ascites fluid abrogated their ability to adoptively transfer resistance.A working hypothesis has been proposed according to which TA3‐Ha tumor cells produce highly reactive membranous decay products which intercept incoming immunocytes or immunoglobulins before they can reach their targets on living tumor cells. Whether this self protection of TA3 ascites tumors can be applied to other tumors remains to be investigated.
The binding of anti‐immunoglobulin antibodies to rat thymocytes and thoracic duct lymphocytes
Authors: Jensenius J. C. , Williams A. F. 
Published: February 2007

AbstractAnti‐rat immunoglobulin antibodies were purified by acid elution from immunoadsorbents, and their binding to rat thoracic duct lymphocytes and thymocytes studied. Satisfactory binding was only achieved when pepsindegraded reagents were used and anomalous results were obtained if aggregated antibody was present.From the thoracic duct lymphocytes of the PVG/c strain rat, 40–50 % of cells bound 20000–150000 molecules of anti‐rat Fab antibody, or 8000–60000 molecules of anti‐IgM reagent. Only 2.5 % of the cells bound more than 8000 molecules of anti‐IgG2a+2b antibody and few thymus cells bound any antibody at this level.Thoracic duct lymphocytes without large amounts of surface immunoglobulin also bound anti‐Fab specifically. The binding was in the range of 200–3000 molecules per cell.
Cytotoxicity of human lymphocytes induced by pokeweed mitogen or in mixed lymphocyte culture. Specificity and nature of effector cells
Authors: Stejskal Vera , Härfast B. , Holm G. , Perlmann P. 
Published: February 2007

AbstractPurified human peripheral blood lymphocytes were activated in vitro with pokeweed mitogen (PWM) or with mitomycin‐treated allogeneic lymphocytes (MLC). After incubation for several days, stimulation to DNA synthesis and cytotoxicity for phytohemagglutinin (PHA)‐activated lymphoblasts or for Chang cells was tested. Lymphocytes activated with PWM for 3–6 days were cytotoxic for both autologous and allogeneic PHA‐induced lymphoblasts. In addition, they destroyed human tissue culture cells (Chang cells) effectively. In contrast, lymphocytes activated in MLC were cytotoxic for lymphoblasts bearing stimulator cell antigens, but not for autologous PHA‐lymphoblasts. Cytotoxicity for Chang cells was variable. Lymphocytes which proliferate and become cytotoxic after activation in MLC are of T cell origin, since their ability is not reduced by prior removal of non‐T cells on columns charged with human IgG‐anti‐IgG complexes. On the other hand, this procedure reduced both DNA synthesis and cytotoxicity of PWM‐activated lymphocytes. This suggests that cells equipped with surface immunoglobulin and/or Fc recptors were required for activation of these cultures, or alternatively, were among the cells which responded to PWM by DNA synthesis and cytotoxicity.
Ultrastructural distribution and redistribution of alloantigens and concanavalin A receptors on the surface of mouse lymphocytes
Authors: de Petris S. , Raff M. C. 
Published: February 2007

AbstractThe distribution of theta, TL and H‐2 alloantigens and concanavalin A (Con A) receptor sites on mouse lymphocytes was studied using immunoferritin electron microscopy. The alloantigens were demonstrated using alloantibodies followed by either a mono‐ or divalent anti‐mouse Ig‐ferritin conjugate, while Con A receptors were labeled directly with Con A‐ferritin and in some cases, cross‐linked by an additional layer of anti‐ferritin antibody. The results indicate that these membrane macromolecules are mobile in the plane of the membrane and that their distribution can be altered by cross‐linking them with multivalent antibodies or ligands. It is concluded that all lymphocyte membrane macromolecules are probably potentially mobile and diffusely dispersed in the unperturbed membrane, and that any patchy distribution seen is artifactually induced by the multivalent ligands used to demonstrate them.
T cell synergy in mixed lymphocyte culture‐induced cytolysis
Authors: Häyry P. , Andersson L. C. 
Published: February 2007

AbstractWhen 0.9 × 106 mouse thymus cells plus 0.1 × 106 peripheral lymph node cells are primed together by allogeneic cells in one‐way mixed lymphocyte culture (MLC), both the MLC blast response and subsequent target cell lysis in cell‐mediated cytolysis are 5–10 times higher than the sum of separate responses. When 0.5 × 106 thymus cells plus 0.5 × 106 peripheral lymph node cells are similarly primed, the MLC response is still superadditive. However, this is no longer so when 0.1 × 106 thymus cells plus 0.9 × 106 peripheral lymph node cells are used as responders. The results confirm the earlier observation on similar T cell synergism in the graft‐vs‐host response. Furthermore, the in vitro method, that can be split into proliferative and effector phases, enables the investigation of the cooperative mechanism in detail.
IgM in bone marrow‐derived lymphocytes. Changes in synthesis, turnover and secretion, and in numbers of molecules on the surface of B cells after mitogenic stimulation
Authors: Melchers F. , Andersson J. 
Published: February 2007

AbstractStimulation of small, resting B cells by the mitogen lipopolysaccharide from E. coli induces changes in synthesis, turnover, carbohydrate composition, surface deposition and active secretion of IgM. With increasing time stimulation, the rate of synthesis of the glycoprotein IgM increases over the rates of syntheses of other proteins and carbohydrate‐containing macromolecules. IgM synthesis, being actinomycin D‐sensitive in small, resting lymphocytes, becomes more and more actinomycin D‐resistant. IgM molecules with a median disappearance time around 4 h are synthesized in increasing amounts. These rapidly turning over IgM molecules are no longer shed from the cells as 7–8 S subunits, but are actively secreted as 19 S pentamers. In the secreted 19 S form, they contain the branch sugars galactose and fucose attached to the Hμ‐chains.Within 20 min after addition of the mitogen to unstimulated B cells, surface‐bound Ig determinants disappear and can no longer be approached from the outside of intact cells by anti‐Ig antibodies. “De novo” synthesis refurnishes the original amount of surface‐bound IgM molecules within 12 h. Beyond 12 h after exposure to the mitogen, more and more IgM molecules appear on the surface. At 40 to 60 h after stimulation, between 35 and 100 times more surface‐bound IgM molecules are on the stimulated B cells. The majority of these surface‐bound IgM molecules turn over rapidly with a median disappearance time around 5 h. The surface membrane appears to be an intermediate station in the migration of IgM molecules out of the cell during active secretion.IgM synthesis before and after mitogenic stimulation is discussed as a part of the overall biogenesis of membranes in B cells.
Response of human thymus‐derived (T) and non‐thymus‐derived (B) lymphocytes to mitogenic stimulation in vitro
Authors: Geha R. S. , Merler E. 
Published: February 2007

AbstractHighly pure populations of human T and B lymphocytes were prepared from tonsils using a two‐step fractionation procedure. Cells were first fractionated on discontinuous gradients of bovine serum albumin, then separated on the basis of their reactivity with the sheep red cell intermediates, E and EACl423. More than 95 % of the cells in the final suspensions were either T or B lymphocytes. Phytohemagglutinin and concanavalin A were mitogenic exclusively for T cells. Pokeweed was mitogenic for both T and B cells. T cell proliferation occurred in response to two antigens to which the cell donors were immune: tetanus toxoid (TT) and polyribosephosphate (PRP) capsular antigen of Hemophilus influenzae, type b. B lymphocytes did not transform in response to either PRP, soluble TT, or insoluble TT, but transformed vigorously in the presence of supernatants obtained from TT‐activated T cells.