bluuebunny/crossref_metadata_2025 huggingface dataset:
Venous calibre reduction after intermittent pneumatic compression
Authors: Harfouche J N , Theys S , Scavée V , Hanson P , Schoevaerdts J C , Sturbois X
Published: March 2005

Objective: To evaluate the effect of intermittent pneumatic compression (IPC) on venous calibre.

Methods: A total of 28 subjects were divided into three groups: 15 with venous insufficiency (Var), six with lymphoedema (Lym) and seven healthy (Hlt) subjects. One of each patient's lower limbs were treated with IPC. Both limbs were assessed by a duplex scanner, before and after the treatment, and the calibres were then compared.

Results: A significant decrease in the venous calibre was observed only on the treated limbs. The veins affected were: in the Lym group, the lesser saphena ( P<0.05); in the Var group, the greater saphena at its cross ( P<0.01), the lesser saphena ( P<0.02) and the superficial femoral vein ( P<0.05).

Conclusion: A 40 mmHg IPC was sufficient to enhance some venous tonus, especially in subjects with venous insufficiency, for 15–30 min after the 30 min of treatment.
Critical role of duplex ultrasonography for the advanced management of a venous malformation
Authors: Lee B B , Mattassi R , Choe Y H , Vaghi M , Ahn J M , Kim D I , Huh S H , Lee C H , Kim D Y
Published: March 2005

Objectives: Duplex ultrasonography was assessed for its advanced role as a contemporary guide for the safer management of venous malformation (VM) at the lower extremities through a comparison study with matching magnetic resonance imaging (MRI) and/or ascending phlebography findings.

Methods: A retrospective review of 50 patients with a VM in the lower extremities was performed using the duplex scan findings on the initial diagnosis and the subsequent follow-up assessment of the treatment response. The screening findings of deep vein thrombosis (DVT) development following ethanol sclerotherapy on 40 patients were also included. A marginal vein (lateral embryonal) compression test was also performed on 10 patients, who were candidates for a resection preoperatively, in order to assess its value in predicting the response to the subsequent resection. The duplex scan findings were compared with the available ascending phlebography results in 38 patients, and also with the MRI findings available for all 50 patients.

Results: The duplex scan on the 50 patients confirmed the existence of a normal deep vein system in the lower extremities in 43 patients as the true-positive test findings. One false-negative test finding was subsequently confirmed by an angiographic evaluation. The duplex scan also confirmed the absence of a normal deep vein system in four patients as a true-negative test. MRI subsequently confirmed two false-positive findings in one patient, and angiography confirmed two false-positive findings in another (sensitivity − 97.8%, specificity − 66.7%, positive predictive value − 95.6%, and negative predictive value − 80%). Among a total of 40 patients who received ethanol sclerotherapy, the duplex scan identified DVT in three patients, and also screened out properly in 37 patients through a total of 185 ethanol sclerotherapy sessions. The compression test predicted the surgical outcome successfully in the majority (7/8). The duplex scan appears to have comparable reliability to MRI and/or angiography for diagnosing and managing VM.

Conclusions: The duplex scan can provide the critical haemodynamic information of both the deep venous system and VM lesions quite effectively with the cost-effectiveness of a non-invasive test. In particular, the duplex scan is an excellent test for the safe management of VM of the lower extremity, including the early detection of DVT through multi-session ethanol sclerotherapy.
PLG calls for improved doctor–patient communication
Authors: Towell Elaine
Published: March 2005

You have just taken off in a plane and a voice comes over the tannoy: 'Good morning ladies and gentlemen, this is your flight captain speaking. I want to welcome you aboard this Any Airways economy flight and tell you about the new delegated teamwork flying policy that we at Any Airways have adopted. This flight is a pilot-led service; we delegate key jobs throughout the flight.

'The controls will shortly be handed over to Miss Jones who will take us over the Channel today; she has some experience in air traffic control and has been specifically trained to take aircraft over the Channel. She will then hand over to the co-pilot's assistant for landing. He is a partially trained co-pilot but has received specific training to land the plane.

'Unfortunately the flying time directive has meant that there won't be a pilot actually on your flight today but if you look out of the starboard window you will see another Any Airways plane. This is a scheduled flight and this is where I am based today but don't worry – I'm not far away should anything go wrong. Enjoy your flight.'
Race and Electronically Measured Adherence to Immunosuppressive Medications after Deceased Donor Renal Transplantation
Authors: Weng Francis L. , Israni Ajay K. , Joffe Marshall M. , Hoy Tracey , Gaughan Christina A. , Newman Melissa , Abrams John D. , Kamoun Malek , Rosas Sylvia E. , Mange Kevin C. , Strom Brian L. , Brayman Kenneth L. , Feldman Harold I.
Published: March 2005

Nonadherence to immunosuppressive medications may partly explain the worse allograft outcomes among black recipients of renal transplants. In a prospective cohort study of recipients of deceased donor renal transplants, microelectronic cap monitors were placed on bottles of one immunosuppressive medication to (

1

) measure average daily percentage adherence during the first posttransplantation year and (

2

) determine the factors associated with adherence. A total of 278 transplant recipients who provided sufficient microelectronic adherence data were grouped into four categories of average daily percentage adherence: 95 to 100% adherence (41.0% of patients), 80 to 95% adherence (32.4%), 50 to 80% adherence (12.9%), and 0 to 50% adherence (13.7%). In the unadjusted ordinal logistic regression model, black race was associated with decreased adherence (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.26 to 0.72;

P

= 0.001). Cause of renal disease, Powerful Others health locus of control, transplant center, and dosing frequency were also associated with adherence. After adjustment for transplant center and dosing frequency, the association between black race and decreased adherence was substantially attenuated (OR, 0.65; 95% CI, 0.38 to 1.14,

P

= 0.13). Transplant center (

P

= 0.003) and increased dosing frequency (OR, 0.43; 95% CI, 0.22 to 0.86, for three or four times per day dosing; OR, 2.35; 95% CI, 1.01 to 5.45, for daily dosing;

versus

two times per day dosing;

P

= 0.003) remained independently associated with adherence. Other baseline demographic, socioeconomic, medical, surgical, and psychosocial characteristics were not associated with adherence. The transplant center and dosing frequencies of immunosuppressive medications are associated with adherence and explain a substantial proportion of the race-adherence relationship.
Silicon Nanocrystals: Size Matters
Authors: Heitmann J. , Müller F. , Zacharias M. , Gösele U.
Published: March 2005

This paper reviews new approaches to size‐controlled silicon‐nanocrystal synthesis. These approaches allow narrowing of the size distribution of the nanocrystals compared with those obtained by conventional synthesis processes such as ion implantation into SiO2 or phase separation of sub‐stoichiometric SiOx layers. This size control is realized by different approaches to introducing a superlattice‐like structure into the synthesis process, by velocity selection of silicon aerosols, or by the use of electron lithography and subsequent oxidation processes. Nanocrystals between 2 and 20 nm in size with a full width at half maximum of the size distribution of 1 nm can be synthesized and area densities above 1012 cm–2 can be achieved. The role of surface passivation is elucidated by comparing Si/SiO2 layers with superlattices of fully passivated silicon nanocrystals within a SiO2 matrix. The demands on silicon nanocrystals for various applications such as non‐volatile memories or light‐emitting devices are discussed for different size‐controlled nanocrystal synthesis approaches.
Cover Picture: Novel Photoactive Single‐Walled Carbon Nanotube–Porphyrin Polymer Wraps: Efficient and Long‐Lived Intracomplex Charge Separation (Adv. Mater. 7/2005)
Authors: Guldi D. M. , Taieb H. , Rahman G. M. A. , Tagmatarchis N. , Prato M.
Published: March 2005

The figure on the cover portrays a novel donor–acceptor nanoassembly, based on a single‐walled carbon nanotube (SWNT) as the electron acceptor and poly(methyl methacrylate) (PMMA)‐carrying porphyrin units (H2P) as the excited‐state electron donors. In these supramolecular “polymer wraps”, reported on p. 871 by Guldi and co‐workers, SWNTs quench the photoexcited H2P chromophores, resulting in the creation of microsecond‐lived radical ion pairs.
Real‐time product morphology monitoring in crystallization using imaging technique
Authors: De Anda J. Calderon , Wang X. Z. , Lai X. , Roberts K. J. , Jennings K. H. , Wilkinson M. J. , Watson D. , Roberts D.
Published: March 2005

Many speciality organic chemical products, such as pharmaceuticals are crystals that exhibit multiple morphological forms and habits that are of critical importance not only to the end use properties of the products, but also to their downstream processing, such as in filtration and handling and in transport and storage. It is known that minor changes in operating conditions, such as cooling rates and supesaturation can have significant impact on the product leading to batch‐to‐batch variation. As a result, precision manufacture of crystalline products demands on‐line techniques for real‐time measurement of crystal morphology. The use of a non‐invasive on‐line imaging technique in a batch reactor for monitoring cooling crystallization of (L)‐glutamic acid which exhibits two polymorphs, alpha and beta is described. The technique was found to allow real‐time observation of some temporal moments that are critical in the crystallization process, in particular the crystallization onset and transformation between the two polymorphs. For validation and benchmarking purpose, an off‐line system for particle characterization, the PharmaVision 830, and photo‐microscope were also used in the study in parallel with the on‐line imaging system. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Monitoring of CaCO3 production on a spinning disc reactor using conductivity measurements
Authors: Burns J. R. , Jachuck R. J. J.
Published: March 2005

A method of monitoring CaCO3 production from absorption of CO2 into an aqueous solution of Ca(OH)2 is described. Its application to the measurement of Ca(OH)2 conversion across different radial zones on a spinning disc reactor is discussed and results from experiments are presented. Links between conversion and models based on diffusive mass transfer into a thin rotating film are examined and a correlation with Fourier and Reynolds numbers shown. Estimations of mass‐transfer coefficients based on the experimental results are provided and comparisons made with previous work. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Analysis of heterogeneously catalyzed reactions close to bubbles
Authors: Raffensberger Jodi A. , Glasser Benjamin J. , Khinast Johannes G.
Published: March 2005

The objective of this work is to use numerical simulations to show how bubble (size and shape) and particle properties can influence the selectivity of fast heterogeneously catalyzed gas–liquid reactions. For fast gas–liquid–solid reactions, the reaction occurs primarily in the wake of the bubble and is thus dependent only on the mixing in this region. This work investigates how the wake structure changes for different bubble shapes and how catalyst particles distribute for different Stokes number particles. Finally, the results of this work will be applied to two industrially relevant reaction systems to show how choosing the correct design and operating parameters of a system can significantly influence the selectivity of fast heterogeneously catalyzed gas–liquid reactions. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Dispersion coefficient prediction within a bed packed with perfusive particles
Authors: Albusairi Bader H. , Hsu James T.
Published: March 2005

The effective medium model of perfusive particles has been used to modify the dispersion coefficient of a packed bed to account for intraparticle velocity and internal structure of the perfusive particles. In this model, the diffusivity factor has been derived by solving the steady‐state diffusion equation in the three regions (that is, external, envelope, and internal regions) of the effective medium model and proved experimentally. The diffusivity factor is incorporated with hydrodynamic parameters obtained earlier to modify the dispersion coefficient of bed packed with perfusive particles. It was found that the diffusivity factor is independent of perfusive particle shape. Also, it was found that the uniformity of perfusive particles is not a necessary condition, once average accessible porosity is considered instead of actual porosity. Finally, it was shown that a significant error would be introduced to predict the performance of bed packed with perfusive particles if the effect of perfusive phenomena on the dispersion coefficient of a packed bed were not considered. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Autosomal dominant microtia and ocular coloboma: New syndrome or an extension of the oculo‐auriculo‐vertebral spectrum?
Authors: Beck Anita E. , Hudgins Louanne , Hoyme H. Eugene
Published: March 2005

The oculo‐auriculo‐vertebral (OAV) spectrum is an etiologically heterogeneous condition classically consisting of microtia, hemifacial microsomia, epibulbar dermoids, and vertebral anomalies. Other eye findings described in OAV include upper eyelid colobomas, ptosis, and varying degrees of microphthalmia or even anophthalmia. Iris and/or retinal colobomas have rarely been reported. We describe two familial cases of apparent OAV with ocular colobomas. We postulate that iris and/or retinal colobomas associated with OAV may represent a subgroup within the OAV spectrum with autosomal dominant inheritance, as in the families described herein. Since microtia can result from aberrant migration of neural crest cells into the first and second branchial arches during early embryonic development, and concomitant deficient neural crest migration into the developing eye can lead to ocular coloboma and or iris heterochromia, it may be that the altered gene or genes in our familial cases are involved with regulation of neural crest development. © 2005 Wiley‐Liss, Inc.
Mental retardation in a boy with anterior cervical hypertrichosis
Authors: Corona‐Rivera J. Román , González‐Abarca Sergio , Hernández‐Rocha Juan , García‐Cruz Diana , Corona‐Rivera Alfredo
Published: March 2005

Anterior cervical hypertrichosis (ACH) is a rare form of localized hypertrichosis with 15 previously reported cases. ACH has been considered to be a dominant phenotype, either X‐linked or autosomal [OMIM 600457]. ACH was associated with hereditary motor and sensory neuropathy (HMSN) in one family, in which the proband also exhibited severe chorioretinal degeneration and optic atrophy, probably as a different entity [OMIM 239840]. A Mexican boy with congenital ACH associated with moderate mental retardation, abnormal EEG, mild microcephaly, hypertrichosis on the back, and hallux valgus is presented here. An equal sex ratio found in 16 reported cases as well as the suggestion of a paternal age effect in one report appear most consistent with an autosomal dominant mode of inheritance for this trait. It remains unclear if isolated ACH, ACH–HMSN, or other associated findings reported in patients with ACH, including unusual features found in our case, are part of ACH or fortuitous associations, due to the small number of affected patients and different ascertainment biases present in previous reports. © 2005 Wiley‐Liss, Inc.
Inappropriate tall stature and renal ectopy in a male patient with X‐linked congenital adrenal hypoplasia due to a novel missense mutation in the DAX‐1 gene
Authors: Franzese Adriana , Brunetti‐Pierri Nicola , Spadaro Raffaella , Mukai Tokuo , Valerio Giuliana
Published: March 2005

Mutations in DAX‐1 gene cause congenital adrenal hypoplasia (AHC). We present a male patient affected by X‐linked adrenal hypoplasia congenita due to a novel DAX‐1 missense mutation. The mutation V287G affects the C‐terminal end of the DAX‐1 protein which plays an important role in functioning of the receptor. In addition, our patient presented an inappropriate tall stature and renal ectopy, which have not been described in AHC so far. © 2005 Wiley‐Liss, Inc.
Folate supplementation in three genetic models: Implications for understanding folate‐dependent developmental pathways
Authors: Kappen Claudia
Published: March 2005

Supplementation of a pregnant mother's diet with folate has been shown to protect the developing embryo from birth defects in humans as well as rodent animal models. Folate supplementation not only reverses a potential nutritional deficiency; folate effectively prevents defects even when the mother's nutritional status is normal. These findings indicate that folate is able to interact with the molecular pathways that control normal embryonic development. Supplementation studies in animals provide the experimental starting point for the identification of such folate‐responsive pathways. This review summarizes the progress to date in understanding the folate response in genetic models of birth defects in the mouse. © 2005 Wiley‐Liss, Inc.
Mouse models of neural tube defects: Investigating preventive mechanisms
Authors: Greene Nicholas D.E. , Copp Andrew J.
Published: March 2005

Neural tube defects (NTD), including anencephaly and spina bifida, are a group of severe congenital abnormalities in which the future brain and/or spinal cord fail to close. In mice, NTD may result from genetic mutations or knockouts, or from exposure to teratogenic agents, several of which are known risk factors in humans. Among the many mouse NTD models that have been identified to date, a number have been tested for possible primary prevention of NTD by exogenous agents, such as folic acid. In genetic NTD models such as Cart1, splotch, Cited2, and crooked tail, and NTD induced by teratogens including valproic acid and fumonisins, the incidence of defects is reduced by maternal folic acid supplementation. These folate‐responsive models provide an opportunity to investigate the possible mechanisms underlying prevention of NTD by folic acid in humans. In another group of mouse models, that includes curly tail, axial defects, and the Ephrin‐A5 knockout, NTD are not preventable by folic acid, reflecting the situation in humans in which a subset of NTD appear resistant to folic acid therapy. In this group of mutants alternative preventive agents, including inositol and methionine, have been shown to be effective. Overall, the data from mouse models suggests that a broad‐based in utero therapy may offer scope for prevention of a greater proportion of NTD than is currently possible. © 2005 Wiley‐Liss, Inc.
Epithelial cell polarity genes are required for neural tube closure
Authors: Doudney Kit , Stanier Philip
Published: March 2005

Human neural tube defects (NTD) are a heterogeneous group that exhibit complex inheritance, making it difficult to identify the underlying cause. Due to the uniform genetic background, inbred mouse strains are a more amenable target for genetic studies. We investigated the loop‐tail (Lp) mouse as a model for the severe NTD, craniorachischisis. A homozygous point mutation was identified in the transmembrane protein Vangl2, which in Drosophila has been shown to function in the planar cell polarity (PCP) pathway. Morphological analysis of the Lp mice shows that the defect results from an abnormally broad floor plate, most likely through a failure in convergent extension. The elevated neural folds remain too far apart to contact, inhibiting neural tube closure. Recently, two other mouse mutants (crash and circletail) were described with a similar phenotype to Lp and were investigated as potentially new alleles. Mapping studies, however, showed that both mutants segregated to distinct loci. In the crash (Crsh) mouse, a mutation was identified in Celsr1, a seven pass transmembrane receptor that encodes a protein orthologous to Drosophila Flamingo. Like Vangl2, this gene also functions in the PCP pathway. While in circletail, a point mutation was identified introducing a premature stop codon into the apical‐basal cell polarity gene scribble (Scrb1). We subsequently demonstrated a genetic interaction between all three genes, where double heterozygotes exhibit the same homozygous NTD phenotype. This strongly suggests both a candidate gene pathway and that interaction between independent recessive alleles may be a possible explanation for the complex inheritance in severe human NTD. © 2005 Wiley‐Liss, Inc.
Non‐multifactorial neural tube defects
Authors: Lynch Sally Ann
Published: March 2005

Although most neural tube defects (anencephaly, spina bifida) occur as isolated malformations, a substantial proportion are attributable to chromosome anomalies, known teratogens, or component manifestations of multiple anomaly syndromes. This review describes known chromosome alterations and the candidate genes residing in the altered region, as well as syndromes associated with neural tube defects and causative genes, if known. 2005 Wiley‐Liss, Inc.
The Intermolecular Pauson–Khand Reaction
Authors: Gibson Susan E. , Mainolfi Nello
Published: March 2005

Five membered carbocycles are important building blocks for many biologically active molecules. Moreover, substituted cyclopentenones (e.g. cyclopentenone prostaglandins) exhibit characteristic biological activity. The efficiency and atom economy of the Pauson–Khand reaction render this process potentially one of the most attractive methods for the synthesis of such compounds. Although it was discovered in its intermolecular form, the scope of the intermolecular Pauson–Khand reaction has always been limited by the poor reactivity and selectivity of the alkene component. The past decade, especially the last three years, has seen concerted efforts to broaden the scope of this reaction. In this overview, we provide a comprehensive and critical coverage of the intermolecular Pauson–Khand reaction based on the reactivity characteristics of different classes of alkenes and a rationalization of successes and misfortunes in this area.
Reactive copolymerization of various monomers based on lactams and lactones in a twin‐screw extruder
Authors: Kim In , White James L.
Published: March 2005

The synthesis of polyamide–polyester‐based diblock, triblock, and random block copolymers was carried out in a modular, corotating twin‐screw extruder via reactive extrusion. ω‐Lauryllactam (LA), ϵ‐caprolactam (CA), and ϵ‐caprolactone (CL) were used as monomers for the synthesis of the copolymers in the twin‐screw extruder. Generally, CL was added downstream. Sodium hydride was the initiator, and N‐acetylcaprolactam was the coinitiator. The syntheses of poly(LA‐b‐CL), poly(LA/CA‐b‐CL), and poly(LA‐b‐CA‐b‐CL) were attempted. Poly(LA/CA‐b‐CL) was a random LA–CA copolymer with a block of CL. The simultaneous feeding of LA and CA with the initiator systems was added to the first hopper of the twin‐screw extruder, and the addition of CL downstream to a second hopper (without the initiator) was used to form this block copolymer. The thermal, mechanical, rheological, and structural properties of the various copolymers were investigated and compared with those of the homopolymers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96:1875–1887, 2005
Preparation and mechanical characteristics of poly(methylaniline) based electrorheological fluid
Authors: Choi S. B. , Choi H. J. , Choi Y. T. , Wereley N. M.
Published: March 2005

Poly(methylaniline) (PMA) was chemically synthesized and its polymerization was confirmed via an FT‐IR. Anhydrous electrorheological (ER) fluid consisting of semiconducting PMA particles dispersed in silicone oil was then prepared, and its mechanical properties such as tensile and compressive stresses were experimentally investigated using a squeeze mode type apparatus that was devised by integrating a motion controller and data acquisition system. The intensity of electric field, electrode velocity, and initial gap were chosen as important test parameters that influence the tensile and compressive characteristics of the ER fluid. The maximum tensile stresses were evaluated at each condition, and a microstructure was also investigated during compressive motion. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1924–1929, 2005
Antifungal Activity and Studies on Mode of Action of Novel Xanthoxyline‐Derived Chalcones
Authors: Boeck Paula , Leal Paulo C. , Yunes Rosendo A. , Filho Valdir Cechinel , López Silvia , Sortino Maximiliano , Escalante Andrea , Furlán Ricardo L. E. , Zacchino Susana
Published: March 2005

Chalcones and chalcone‐like compounds, most of them new ones, prepared by base‐catalyzed condensation of appropriate aldehydes and xanthoxyline, were tested for antifungal properties against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the agar dilution assay. Results indicate that neither the sole presence of a “xanthoxyline‐like” substitution pattern nor a 2′‐OH substituent on ring A are sufficient for these compounds to have antifungal properties. The chalcone 3‐(2‐chlorophenyl)‐1‐(2′‐hydroxy‐4′,6′‐dimethoxyphenyl)prop‐2‐en‐1‐one, with a Cl atom in the ortho position of benzene ring B showed the best antifungal activity against standardized strains of Trichophyton rubrum (MIC = 12.5 μg/mL) and inhibited all of the ten clinical isolates of T. rubrum tested (MIC at which 50 % [MIC50] and 90 % [MIC90] of the isolates were inhibited = 12.5 and 25 μg/mL). Regarding its mode of action, the Neurospora crassa assay showed a blotchy appearance in the inhibition halo produced by this chalcone, strongly suggesting that it could act by inhibiting the fungal cell wall. This chalcone seems to be an hyphal malformation inducer, since a clear curling of the hypha was observed in this hazy zone at a magnification of × 400. This work strongly contributes to the knowledge of the antifungal properties of hydroxy‐chalcones.
Modellierung der Baugrund‐Tragwerk‐Interaktion: Ein Fundament der geotechnischen Entwurfspraxis
Authors: Boley Conrad , Unold Florian , Morgen Karl , Wurzer Otto
Published: March 2005

Der vorliegende Beitrag beschäftigt sich mit den Ursachen und Auswirkungen der Baugrund‐Tragwerk‐Interaktion. Welche Möglichkeiten es gibt, die Interaktion zwischen Baugrund und Tragwerk zu berücksichtigen, bzw. welche Folgen es haben kann, wenn sie vernachlässigt wird, soll anhand einiger Beispiele aus der Baupraxis verdeutlicht werden.
Beton‐Bodenplatten für Hallen‐ und Freiflächen: Konstruktion und Bemessung
Authors: Stenzel Gerhard
Published: March 2005

Beton‐Bodenplatten im Industriebau dienen als Fahrbahn, Lagerfläche und Gründungsbauteil, z. B. für Hochregallager. An die Gebrauchseigenschaften Rutschfestigkeit, Ebenheit, Verschleißfestigkeit, Widerstand gegen chemischen Angriff, Dauerhaftigkeit und Standsicherheit werden hohe Anforderungen gestellt. Deshalb ist gerade bei Beton‐Bodenplatten eine ganzheitliche Betrachtung der Planungs‐ und Bauaufgabe besonders wichtig, um eine wirtschaftliche Konstruktion (niedrige Herstellkosten und geringer Unterhaltsaufwand) gemeinsam mit dem Bauherrn festlegen zu können. In diesem Beitrag werden die wesentlichen Konstruktions‐ und Bemessungsregeln für Beton‐Bodenplatten zusammenfassend dargestellt, um das Finden der für jeden Einzelfall optimalen Lösung zu erleichtern.
Oberflächenbearbeitung von Industriebetonböden bei Verwendung von SVB mit und ohne Fasern
Authors: Satter Ingo , Linsel Stefan , Knoop Volker , Dehn Frank
Published: March 2005

Selbstverdichtender Beton (SVB) ist eine der wichtigen baustofftechnischen Innovationen der letzten Jahre, der jedoch die Hersteller und Verarbeiter bei bestimmten Anwendungen immer noch vor Probleme stellt. Hierzu zählt beispielsweise die Verwendung von SVB für Industriebetonböden. Insbesondere hinsichtlich der Oberflächenbearbeitung und Ebenheitsanforderungen werden Schwierigkeiten gesehen. Nachfolgender Bericht faßt Praxisversuche zu diesem Aspekt zusammen und zeigt, daß auch für diesen Anwendungsfall der SVB eine Alternative zur konventionellen Bauweise darstellt.
Wohin mit der “Platte”? Vergangenheit, Gegenwart und Zukunft der Plattenbausubstanz im Osten Deutschlands
Authors: Künzel Eberhard
Published: March 2005

In Deutschland wurde ab Mitte der 1950er Jahre eine Vielzahl von Wohnungen, insbesondere im Osten Deutschlands, in Plattenbauweise errichtet. Diese Bausubstanz wurde im Rahmen des Programms “Stadtumbau Ost” in den letzten Jahren umfangreich saniert und modernisiert. Heute werden vorwiegend Leistungen des Rückbaus und des Abrisses realisiert, um dem Wohnungsleerstand entgegenzuwirken. Die freigesetzten Baustoffe und Bauteile der Tragstruktur und des technischen Ausbaues sind einer effizienten weiteren Verwertung zuzuführen.
Progressiver Kollaps von Bauwerken
Authors: Starossek Uwe
Published: March 2005

Das Versagen eines Tragwerkselements kann zum Versagen anderer Tragwerkselemente führen. Auf diese Weise kann sich das Versagen als progressiver Kollaps durch große Teile oder die Gesamtheit des Bauwerks fortpflanzen. Es wird ein Überblick über den aktuellen Stand der Forschung im Bereich des progressiven Kollapses gegeben. Grundlagen für eine künftig regelhafte Gewährleistung von Resistenz gegen progressiven Kollaps werden dargelegt. Untersuchungsmethoden sowie Entwurfs‐ und Nachweisregeln werden diskutiert.
Einlagige Rundlitzenseile in Beton: Modellbildung und Anwendungsmöglichkeiten
Authors: Avak Ralf , Wille Frank
Published: March 2005

Die allgemeingültige Anwendung von nicht vorgespannten Stahlseilen als statisch anrechenbare Bewehrung erfordert genaue Kenntnisse über das Verbundverhalten derselben mit dem umgebenden Beton. Darüber hinaus wird eine Charakterisierung des Dehnverhaltens der Betondrahtseile erforderlich. Umfangreiche experimentelle Untersuchungen sind hierzu umgesetzt worden. Aus den Versuchsergebnissen von Pull‐Out Tests ist eine Verbundspannungs‐Verschiebungsbeziehung abgeleitet worden. Diese erlaubt, den Verbund zwischen einbetoniertem Drahtseil (im folgenden “Betondrahtseil”) und Beton rechnerisch zu erfassen.

Des weiteren wurden umfangreiche Dehntests an Betondrahtseilen durchgeführt, um die Gesetzmäßigkeiten des Verbundwerkstoffs zu formulieren. Aus den Versuchsergebnissen wird eine Bestimmungsgleichung für den Elastizitätsmodul der Betondrahtseile vorgeschlagen. Die Modelle erlauben die Berechnung von Verankerungslängen und können Rißbreiten abschätzen. Hieraus lassen sich Einsatzmöglichkeiten ableiten. Im vorliegenden Beitrag werden bestehende und potentielle Anwendungen von Betondrahtseilen vorgestellt und diskutiert.
Das neue Mercedes‐Benz Museum in Stuttgart. Oder: Von der Zwangsläufigkeit des dreidimensionalen Planens
Authors: Klein Dietmar
Published: March 2005

In unmittelbarer Nähe zum DaimlerChrysler‐Werk in Stuttgart‐Untertürkheim entsteht bis 2006 das neue Mercedes‐Benz Museum. Das Museum wird auf 16500 Quadratmetern Ausstellungsfläche 175 Exponate beherbergen und voraussichtlich 700000 Besucher pro Jahr anziehen. Das Gebäude zeichnet sich durch seine hochkomplexe Geometrie aus, die eine äußerst enge Zusammenarbeit aller beteiligten Planer und der ausführenden Firma verlangte sowie die völlige Planung des Gebäudes in 3D.
Fuß‐ und Radwegbrücke aus Hochleistungsbeton: Brücke über die Ackermannstraße in München
Authors: Wulf Ralf , Stante Christian , Scholz Ulrich , Krumpholz Peter
Published: March 2005

In einer städtebaulich exponierten Lage ist es geradezu obligatorisch, für ein Brückenneubauprojekt einen Realisierungswettbewerb auszuloben, wenn das Ergebnis eine wirtschaftliche Lösung mit hohem gestalterischen Anspruch sein soll. Der Siegerentwurf überzeugte die Jury nicht nur durch die elegante Linienführung und hohe Übereinstimmung zwischen landschaftlicher und gebauter Struktur, sondern auch durch die Verwendung von modernen Werkstoffen wie Hochleistungsbeton und Glas als Brüstungselement. Mit diesen innovativen Baustoffen ließ sich ein schlankes und transparentes Bauwerk verwirklichen. Eine zwingende Voraussetzung für den erfolgreichen Einsatz von Hochleistungsbeton ist jedoch die genaue Kenntnis der Material‐ und Verarbeitungseigenschaften. Eingehende Untersuchungen und Prüfungen vor Ausführungsbeginn sind für die Bauwerksqualität entscheidend, praxisnahe Versuchsanordnungen sind hierbei unumgänglich. Der Beitrag schildert die Grundlagen, Anforderungen und Ergebnisse des Wettbewerbs und berichtet über Erfahrungen im Umgang mit Hochleistungsbeton und Glas im Brückenbau.
Gene delivery through cell culture substrate adsorbed DNA complexes
Authors: Bengali Zain , Pannier Angela K. , Segura Tatiana , Anderson Brian C. , Jang Jae‐Hyung , Mustoe Thomas A. , Shea Lonnie D.
Published: March 2005

Efficient gene delivery is a fundamental goal of biotechnology and has numerous applications in both basic and applied science. Substrate‐mediated delivery and reverse transfection enhance gene transfer by increasing the concentration of DNA in the cellular microenvironment through immobilizing a plasmid to a cell culture substrate prior to cell seeding. In this report, we examine gene delivery of plasmids that were complexed with cationic polymers (polyplexes) or lipids (lipoplexes) and subsequently immobilized to cell culture or biomaterial substrates by adsorption. Polyplexes and lipoplexes were adsorbed to either tissue culture polystyrene or serum‐adsorbed tissue culture polystyrene. The quantity of DNA immobilized increased with time of exposure, and the deposition rate and final amount deposited depended upon the properties of the substrate and complex. For polyplexes, serum modification enhanced reporter gene expression up to 1500‐fold relative to unmodified substrates and yielded equivalent or greater expression compared to bolus delivery. For lipoplexes, serum modification significantly increased the number of transfected cells relative to unmodified substrates yet provided similar levels of expression. Immobilized complexes transfect primary cells with improved cellular viability relative to bolus delivery. Finally, this substrate‐mediated delivery approach was extended to a widely used biomaterial, poly(lactide‐co‐glycolide). Immobilization of DNA complexes to tissue culture polystyrene substrates can be a useful tool for enhancing gene delivery for in vitro studies. Additionally, adapting this system to biomaterials may facilitate application to fields such as tissue engineering. © 2005 Wiley Periodicals, Inc.
Validity of the Glasgow Aneurysm Score and the Hardman Index in predicting outcome after ruptured abdominal aortic aneurysm repair
Authors: Tambyraja A L , Fraser S C A , Murie J A , Chalmers R T A
Published: March 2005

Background

The Glasgow Aneurysm Score and the Hardman Index have been recommended as predictors of outcome after repair of ruptured abdominal aortic aneurysm (AAA). This study aimed to assess their validities.

Methods

Patients admitted to a single unit with a ruptured AAA over a 2-year interval (2000–2001) were identified from a prospectively compiled database. Hospital records of all patients undergoing attempted operative repair were reviewed. The Glasgow Aneurysm Score and the Hardman Index were calculated retrospectively and related to clinical outcome.

Results

One hundred patients were admitted with a ruptured AAA. Of these, 82 underwent attempted operative repair and were included in the study: 68 men and 14 women, of median age 73 (range 54–87) years. Thirty (37 per cent) patients died after the operation. The Glasgow Aneurysm Score was a poor predictor of postoperative mortality. The area under the Receiver–Operator Characteristic curve was 0·606 (P = 0·112, 95 per cent c.i. 0·483–0·729). Similarly, the Hardman Index failed to predict postoperative mortality accurately (P = 0·211, χ2 for trend). Of nine patients in this series with three or more Hardman criteria, generally held to be fatal, six survived.

Conclusion

Contrary to previous reports, The Glasgow Aneurysm Score and the Hardman Index were poor predictors of postoperative mortality after repair of a ruptured AAA in this study.
The role of primary repair for colonic injuries in wartime
Authors: Hudolin T , Hudolin I
Published: March 2005

Background

The study reviewed an experience of selective primary repair for penetrating colonic injuries incorporating a number of procedures during the 1992–1995 Bosnia-Herzegovina conflict.

Methods

Of 5370 casualties, 259 (4·8 per cent) had injuries to the colon. The patients were divided into two groups: those who had primary repair and those who needed a colostomy. The patients' records were reviewed to determine the cause of injury (explosive weapons or bullets), the position and type of colon injury, associated injuries, the surgical procedure(s) done, complications related to the colonic wound or its management, and mortality.

Results

Some 122 (47·1 per cent) patients had primary colonic repair and 137 (52·9 per cent) had a colostomy. One hundred and fifty (57·9 per cent) were injured by explosive weapons, 108 (41·7 per cent) had bullet wounds and one (0·4 per cent) a stab injury. Associated injuries were seen in 249 (96·1 per cent) patients. Complications related to the colonic wound or its management developed in 27 per cent of patients after primary repair and 30 per cent after colostomy. Mortality rates were 8·2 per cent and 7·2 per cent, respectively.

Conclusion

Primary repair was a safe and effective treatment for penetrating colonic injuries during war.
Laparoscopic repair of large hiatal hernias
Authors: Aly A , Munt J , Jamieson G G , Ludemann R , Devitt P G , Watson D I
Published: March 2005

Background

The repair of large hiatal hernias can be technically challenging. Most series describing laparoscopic repair report only symptomatic outcomes and the true recurrence rate, including asymptomatic recurrence, is not well documented. This study evaluated the long-term outcome of laparoscopic repair of large hiatal hernias.

Methods

All patients who had undergone laparoscopic repair of a large hiatus hernia (more than 50 per cent of the stomach in the hernia) with a minimum 2-year clinical follow-up were identified from a prospectively maintained database. A standardized questionnaire was used to assess symptoms and a barium swallow radiograph was performed to determine anatomy. Multivariate analysis was used to identify factors associated with recurrence.

Results

Of 100 eligible patients, clinical follow-up was available in 96. Follow-up ranged from 2 to 8 (median 4) years. In patients with preoperative reflux symptoms, there were significant improvements in heartburn and dysphagia scores after surgery. Overall, 80 per cent of patients rated their outcome as good or excellent. Sixty patients underwent a postoperative barium meal examination that identified 14 radiological hernia recurrences (eight small, three medium and three large). Four other patients in this group of 60 had previously undergone reoperation for early and late recurrence (two of each), giving an overall recurrence rate of 18 of 60 (30 per cent). One third of patients with recurrence were totally asymptomatic and the presence of postoperative symptoms did not reliably predict the presence of anatomical recurrence. Younger age and increased weight at operation were independent risk factors contributing to recurrence.

Conclusions

Laparoscopic repair of large hiatal hernias yields good clinical outcome. Recurrence after laparoscopic repair seems to be more common than previously thought. Objective anatomical studies are required to determine the true recurrence rate. The majority of recurrences are not large and do not cause significant symptoms.
Cutting balloon recanalization for femoral artery stenosis in a child: A case report
Authors: Garty Yael , Benson Lee
Published: March 2005

A chronic femoral artery stenosis associated with an ipsilateral leg length discrepancy was found resistant to high‐pressure balloon angioplasty. Improvement in vessel caliber and relief of the stenosis were achieved after a cutting balloon. © 2005 Wiley‐Liss, Inc.
Rapid prototyping to create vascular replicas from CT scan data: Making tools to teach, rehearse, and choose treatment strategies
Authors: Knox K. , Kerber Charles W. , Singel S.A. , Bailey M.J. , Imbesi S.G.
Published: March 2005

Our goal was to develop and prove the accuracy of a system that would allow us to re‐create live patient arterial pathology. Anatomically accurate replicas of blood vessels could allow physicians to teach and practice dangerous interventional techniques and might also be used to gather basic physiologic information. The preparation of replicas has, until now, depended on acquisition of fresh cadaver material. Using rapid prototyping, it should be able to replicate vascular pathology in a live patient. We obtained CT angiographic scan data from two patients with known arterial abnormalities. We took such data and, using proprietary software, created a 3D replica using a commercially available rapid prototyping machine. From the prototypes, using a lost wax technique, we created vessel replicas, placed those replicas in the CT scanner, then compared those images with the original scans. Comparison of the images made directly from the patient and from the replica showed that with each step, the relationships were maintained, remaining within 3% of the original, but some smoothing occurred in the final computer manipulation. From routinely obtainable CT angiographic data, it is possible to create accurate replicas of human vascular pathology with the aid of commercially available stereolithography equipment. Visual analysis of the images appeared to be as important as the measurements. With 64 and 128 slice detector scanners becoming available, acquisition times fall enough that we should be able to model rapidly moving structures such as the aortic root. © 2005 Wiley‐Liss, Inc.
IMPULSE – A New Approach to Process Design
Authors: Bayer T. , Jenck J. , Matlosz M.
Published: March 2005

The methodology of structured multiscale process design offers a unique opportunity for challenging interdisciplinary theoretical and experimental research in an European context, capable of leading to significant improvement in industrial competitiveness in the process industries. In addition, the new approach should have a lasting impact on the teaching of chemical engineering and industrial chemistry, and should contribute to the attractiveness and acceptability of the chemical process industries as well.
Formation of Monomeric and Novolak Azo Dyes in Nanofluid Segments by Use of a Double Injector Chip Reactor
Authors: Günther P. M. , Möller F. , Henkel T. , Köhler J. M. , Groß G. A.
Published: March 2005

The azo coupling of 2‐naphthol and cresol novolaks was performed as an example for organic reactions in a microsegmented flow system with microspectrophotometric on‐line characterization. A lithographically prepared glass/glass chip microreactor was used for the generation of segments and the mixing of reaction partners. The formation of segments and their transport behavior is strongly influenced by the addition of surfactants. The reaction rates were high in alkaline media at room temperature, so that the formation of dyes could be observed by a microscope‐video system. The single reaction volumes were in the range between about 0.05 and 1 μL. The spectrum of each segment was registered with a measuring frequency of 45–50 Hz. The residence time of segments inside the optical measurement channels varied between 0.1 and 1.5 s and is in the range of 0.3 s for typical segment sizes of about 150 nL. The single reaction segments containing azo dyes as well as polymer‐based azo dyes were stored in segment sequences inside capillary Teflon tubes.
Microstructured Mixers for Gas‐Phase Processes – Manufacture, Characterization and Applications
Authors: Pfeifer P. , Bohn L. , Görke O. , Haas‐Santo K. , Schygulla U. , Schubert K.
Published: March 2005

The extremely high mixing quality reached by microstructured mixers in diffusion mixing under laminar flow conditions, as well as in mixing under turbulent flows is attributed to short mixing paths. The design of the micro devices and mixing volumes determine the flow condition to be achieved. In devices fabricated according to the multi‐lamination principle, for instance, both laminar and turbulent mixing may take place due to the generally large mixing volumes. In microstructures, where the mixing volume is only a bit larger than the supply channels of the fluids, the mixing quality is dependent on diffusion or secondary flow, which may improve the mixing results. Commonly, the latter mixers can be scaled up by multiplying the mixing geometry (numbering up of the devices). As very rapid reactions between the mixed media frequently occur in the gas mixing range (e.g., combustion reactions) and turbulent flow is preferred, the present contribution primarily deals with mixers designed by the Institute for Micro Process Engineering (IMVT) on the basis of the multi‐lamination principle. Among the key aspects covered are the manufacture of the pressure‐resistant metal devices by the microstructurization of foil bands and the characterization of these devices by determining their mixing qualities in the gas phase. Studies carried out to assess the suitability of these mixers as flame arresters are also presented. Some model applications will be highlighted.
Microstructured Reactors for Heterogeneously Catalyzed Gas‐Phase Reactions on an Industrial Scale
Authors: Markowz G. , Schirrmeister S. , Albrecht J. , Becker F. , Schütte R. , Caspary K. J. , Klemm E.
Published: March 2005

Heterogeneously catalyzed gas‐phase reactions are of great technical and economic importance in the chemical industry. Enormous resources continue to be expended on the development and optimization of catalysts, technical concepts for reactors, and/or operating conditions. Microreaction technology is very well suited to making extremely valuable contributions here in many different ways. On account of the geometric ratios and also the high specific surface areas, heat‐ and mass‐transport limitations can generally be largely excluded or drastically reduced. This allows process conditions that cannot be realized in most conventional apparatus, as is convincingly demonstrated by, for example, the possibility of safely carrying out reactions involving explosive mixtures.
Mixers with Microstructured Foils for Chemical Production Purposes
Authors: Werner B. , Hessel V. , Löb P.
Published: March 2005

For about the past ten years the Institut für Mikrotechnik Mainz GmbH (IMM) has been engaged in the application of micro structures for chemical micro process engineering. Their advantages – more efficient heat exchange and mass transport – lead to, among other things, an increase in yield and selectivity even while saving resources. The development of microstructured mixers thereby played a key role for carrying out advanced syntheses of fine chemicals, as well as for the generation of dispersions, creams, foams and emulsions. So far, microstructured mixers have been mainly limited to laboratory‐scale or at best pilot plant‐scale – typical maximum flow rates were from 2–100 L/h for low viscosity systems. With the introduction of the StarLaminators StarLam300 and StarLam3000, this barrier could be lifted far beyond 300 L/h up to the m3/h domain. Both apparatus yield at high flow rates a mixing efficiency which reaches the high performance of today's low‐capacity (L/h) micromixers. Therefore, continuity exists from the “real” micromixers and the high‐throughput tools described below to conventionally manufactured static mixers with even higher flow rates. A classification of the mixing efficiency versus the power input confirms this continuity as well.