bluuebunny/crossref_metadata_2025 huggingface dataset:
Interrelations between plasma caffeine concentrations and neurobehavioural effects in healthy volunteers: model analysis using NONMEM
Authors: Seng Kok‐Yong , Teo Wei‐Ling Grace , Fun Chiok‐Yuen David , Law Yu‐Li Lydia , Lim Chin‐Leong
Published: June 2010

The objective was to develop a population pharmacokinetic‐pharmacodynamic model of caffeine's psychomotor effects in healthy, non‐habitual users of caffeine. Twenty Chinese males each received a single dose of 250 mg of caffeine orally. Plasma concentrations of caffeine were determined at various times within 24 h after dosing. The subjects' psychomotor performance was evaluated before and at various times after dosing by a test battery consisting of oculomotor assessment (saccadic velocity) as well as the computerised Swedish Performance Evaluation System. Nonlinear mixed‐effects modelling to analyse the pharmacokinetic‐pharmacodynamic relationships was performed using NONMEM. Model robustness was assessed by a nonparametric bootstrap. The results showed that caffeine caused significant improvements in psychomotor functioning. The time course of these effects was best described by pharmacokinetic/pharmacodynamic models involving an effect compartment. The transfer half‐lives between plasma and effect site for different domains of psychomotor functioning were in the range 24.8–49.5 min. Evaluation of the final models showed close agreement between pairs of bootstrapped and final model parameter estimates (all differences<10%). These results provided the first suggestive evidence that caffeine effects on psychomotor performance occur after some time delay relative to changes in plasma caffeine concentration. The models for the neurobehavioural tests provided similar transfer half‐lives between plasma and effect site. Copyright © 2010 John Wiley & Sons, Ltd.
Prepregnancy obesity: A complex risk factor for selected birth defects
Authors: Carmichael Suzan L. , Rasmussen Sonja A. , Shaw Gary M.
Published: June 2010

Obesity is associated with increased risk of many adverse health conditions. During pregnancy, obesity presents particularly important challenges for both mother and baby. Over the last 20 years, studies have emerged indicating an association between prepregnancy weight and risks of birth defects. However, few studies have examined the mechanisms through which this association occurs. Understanding the underlying mechanisms may provide clues to public health strategies for the prevention of birth defects associated with maternal obesity. This article briefly reviews existing literature on the association between maternal obesity and birth defects, discusses potential underlying mechanisms, and suggests research needed to improve our understanding of this important association. Birth Defects Research (Part A) 2010. © 2010 Wiley‐Liss, Inc.
Effects of alternative styles of risk information on EMF risk perception
Authors: Nielsen Jesper Bo , Elstein Arthur , Gyrd‐Hansen Dorte , Kildemoes Helle Wallach , Kristiansen Ivar Sønbø , Støvring Henrik
Published: June 2010

Risk scenarios characterized by exposures to new technologies with unknown health effects, together with limited appreciation of benefits pose a challenge to risk communication. The present report illustrates this situation through a study of the perceived risk from mobile phones and mobile masts in residential areas. Good information should objectively convey the current state of knowledge. The research question is then how to inform lay people so that they trust and understand the information. We used an Internet‐based survey with 1687 Danish participants randomized to three types of information about radiation from mobile phones and masts. The objective was to study whether different types of information were rated as equally useful, informative, comprehensible, and trustworthy. Moreover, an important issue was whether information would influence risk perception and intended behavior. The conclusion is that lay people rate information about risks associated with a new and largely unknown technology more useful and trustworthy when provided with brief statements about how to handle the risk, rather than more lengthy technical information about why the technology may or may not entail health hazards. Further, the results demonstrate that information may increase concern among a large proportion of the population, and that discrepancies exist between expressed concern and intended behavior. Bioelectromagnetics 31:504–512, 2010. © 2010 Wiley‐Liss, Inc.
Mischen von Hochleistungsbetonen
Authors: Baumert Christian , Garrecht Harald
Published: June 2010

Der aktuelle betontechnologische Kenntnisstand ermöglicht die Entwicklung von Hochleistungsbetonen, die unterschiedlichste Merkmale wie Selbstverdichtung, Festigkeiten deutlich über dem Niveau von Normalbeton und eine deutlich gesteigerte Dauerhaftigkeit aufweisen. Das für die Herstellung von Normalbetonen bekannte 4‐Stoffsystem muss dabei einem 5‐ oder 6‐Stoffsystem weichen, das sich zudem durch eine deutlich reduzierte Wasserzugabe auszeichnet. Entsprechend der komplexeren Mischungszusammensetzung stellen die Hochleistungsbetone höhere Anforderungen an den Mischprozess. Mit konventionellen Mischsystemen, die bei Normalbetonen selbst innerhalb kürzester Mischzeit eine sehr hohe Mischgüte erreichen, erfordert die Herstellung von Hochleistungsbetonen einen deutlich intensiveren Mischenergieeintrag, um die gewünschten Frischbetoneigenschaften zu erzielen.

Untersuchungen am Fachgebiet Werkstoffe im Bauwesen (WIB) an der TU Darmstadt belegen die Vorteile erhöhter Werkzeuggeschwindigkeiten auf die Frischbetoneigenschaften von Hochleistungsbeton. Durch den intensiven und schnellen Aufschluss von Zement können die rheologischen Eigenschaften verbessert und über einen längeren Zeitraum aufrecht erhalten werden. Der Suspensions‐Mischer ermöglicht bei geringem Energieeinsatz eine deutliche Verkürzung der Mischzeit.

The Mixing Process of High Performance Concrete

Based on the current knowledge it is feasible to develop high performance concretes with special features such as self compacting ability, a compressive strength significantly above the average of standard concrete and a noticeable increased durability. The 4‐materials system, a basic principle of the standard concrete production, is substituted by a 5‐ or 6‐materials system that is characterized by a considerable reduced amount of water. Due to their complex mix composition high performance concretes show enhanced requirements concerning the mixing process. Conventional mixing systems are able to produce a high quality outcome for standard concretes within a short time. In contrast to that, a proper prediction of high performance concretes requires a more intensive input of mixing energy in order to deliver a concrete with the desired fresh concrete properties.

Current research activities at the Department of Building Materials, Building Physics and Building Chemistry at the TU Darmstadt prove considerable advantages of higher agitator velocity concerning the fresh concrete characteristics of HPC. An intensive and fast disintegration of cement particles significantly improves rheological attributes of the concrete and sustains them over a longer period of time. The usage of a suspension mixer enables a noticeable reduction of the mixing time and simultaneously decreased energy consumption.
Flow‐regulated glucose and lipid metabolism in adipose tissue, endothelial cell and hepatocyte cultures in a modular bioreactor
Authors: Vinci Bruna , Murphy Ellen , Iori Elisabetta , Marescotti Maria Cristina , Avogaro Angelo , Ahluwalia Arti
Published: June 2010

Static cell culture has serious limitations in its ability to represent cellular behaviour within a live organism. In vivo, cells are constantly exposed to the flow of bodily fluids and contact with other cell types. Bioreactors provide the opportunity to study cells in an environment that more closely resembles the in vivo setting because cell cultures can be exposed to dynamic flow in contact with or in proximity to other cell types. In this study we compared the metabolic profile of a dynamic cell culture system to that of a static cell culture in three different cellular phenotypes: adipocytes, endothelial cells and hepatocytes. Albumin, glucose, free fatty acids, glycerol, and lactate were measured over 48 h. We show that all three cell types have increased glucose uptake in the presence of flow; lactate release was also significantly affected. We provide robust evidence that the presence of flow significantly modifies cellular metabolism. While flow provides a more uniform nutrient distribution and increases metabolite turnover, our results indicate that different cell types have specific metabolic responses to flow, suggesting cell‐specific flow‐regulated activation of metabolite signalling pathways.
A novel microplate‐based screening strategy to assess the cellulolytic potential of Trichoderma strains
Authors: Cianchetta Stefano , Galletti Stefania , Burzi Pier Luigi , Cerato Claudio
Published: June 2010

Bioconversion of lignocellulosic biomass to fuel requires a hydrolysis step to obtain fermentable sugars, generally accomplished by fungal enzymes. An assorted library of cellulolytic microbial strains should facilitate the development of optimal enzyme cocktails specific for locally available feedstocks. Only a limited number of strains can be simultaneously assayed in screening based on large volume cultivation methods, as in shake flasks. This study describes a miniaturization strategy aimed at allowing parallel assessment of large numbers of fungal strains. Trichoderma strains were cultivated stationary on microcrystalline cellulose using flat bottom 24‐well plates containing an agarized medium. Supernatants obtained by a rapid centrifugation step of the whole culture plates were evaluated for extracellular total cellulase activity, measured as filter paper activity, using a microplate‐based assay. The results obtained were consistent with those observed in shake‐flask experiments and more than 300 Trichoderma strains were accordingly characterized for cellulase production. Five strains, displaying on shake‐flasks at least 80% of the activity shown by the hyper‐cellulolytic mutant Trichoderma Rut‐C30, were correctly recognized by the screening on 24‐well plates, demonstrating the feasibility of this approach. Cellulase activity distribution for the entire Trichoderma collection is also reported. One strain (T. harzianum Ba8/86) displayed the closest profile to the reference strain Rut‐C30 in time course experiments. The method is scalable and addresses a major bottleneck in screening programs, allowing small‐scale parallel cultivation and rapid supernatant extraction. It can also be easily integrated with high‐throughput enzyme assays and could be suitable for automation. Biotechnol. Bioeng. 2010;107: 461–468. © 2010 Wiley Periodicals, Inc.
Alkali‐based AFEX pretreatment for the conversion of sugarcane bagasse and cane leaf residues to ethanol
Authors: Krishnan Chandraraj , Sousa Leonardo da Costa , Jin Mingjie , Chang Linpei , Dale Bruce E. , Balan Venkatesh
Published: June 2010

Sugarcane is one of the major agricultural crops cultivated in tropical climate regions of the world. Each tonne of raw cane production is associated with the generation of 130 kg dry weight of bagasse after juice extraction and 250 kg dry weight of cane leaf residue postharvest. The annual world production of sugarcane is ∼1.6 billion tones, generating 279 MMT tones of biomass residues (bagasse and cane leaf matter) that would be available for cellulosic ethanol production. Here, we investigated the production of cellulosic ethanol from sugar cane bagasse and sugar cane leaf residue using an alkaline pretreatment: ammonia fiber expansion (AFEX). The AFEX pretreatment improved the accessibility of cellulose and hemicelluloses to enzymes during hydrolysis by breaking down the ester linkages and other lignin carbohydrate complex (LCC) bonds and the sugar produced by this process is found to be highly fermentable. The maximum glucan conversion of AFEX pretreated bagasse and cane leaf residue by cellulases was ∼85%. Supplementation with hemicellulases during enzymatic hydrolysis improved the xylan conversion up to 95–98%. Xylanase supplementation also contributed to a marginal improvement in the glucan conversion. AFEX‐treated cane leaf residue was found to have a greater enzymatic digestibility compared to AFEX‐treated bagasse. Co‐fermentation of glucose and xylose, produced from high solid loading (6% glucan) hydrolysis of AFEX‐treated bagasse and cane leaf residue, using the recombinant Saccharomyces cerevisiae (424A LNH‐ST) produced 34–36 g/L of ethanol with 92% theoretical yield. These results demonstrate that AFEX pretreatment is a viable process for conversion of bagasse and cane leaf residue into cellulosic ethanol. Biotechnol. Bioeng. 2010;107: 441–450. © 2010 Wiley Periodicals, Inc.
Fibroblast response to interstitial flow: A state‐of‐the‐art review
Authors: Dan Liu , Chua Chee‐Kai , Leong Kah‐Fai
Published: June 2010

Interstitial flow (IF) modulates both the biochemical and biophysical cues surrounding cells. It represents a very important regulating mechanism for cell/tissue function and has been commonly utilized in tissue engineering (TE). This article discusses the possible regulating mechanisms of IF on fibroblasts, the various fibroblast responses to IF, the current challenges in understanding the IF–fibroblast relationship and the application of IF for fibroblast involved TE. In particular, IF can affect fibroblast growth at both intracellular (e.g., calcium signaling, protein/proteinase secretion) and cellular (e.g., autocrine/paracrine signaling, proliferation, differentiation, alignment, adhesion, migration) levels. One major challenge for understanding IF–fibroblast interaction has been the determination of the flow and cell growth condition at microlevel especially in a three‐dimensional environment. To utilize IF and optimize the fluidic environment for TE, several influencing factors in the system including perfusate composition, flow profile, nutrient supply, signaling molecule effect, scaffold property, and fibroblast type should be considered. Biotechnol. Bioeng. 2010;107: 1–10. © 2010 Wiley Periodicals, Inc.
Response to induction therapy in oesophageal and cardia carcinoma using Mandard tumour regression grade or size of residual foci (Br J Surg 2010; 97: 719–725)
Authors: Chua T C
Published: June 2010

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Novel technology to provide an enriched therapeutic cell concentrate from bone marrow aspirate
Authors: Ridgway Jonathan , Butcher Andrew , Chen Pei‐Sheng , Horner Alan , Curran Stephen
Published: June 2010

Current strategies to repair fractures rely on orthopaedic surgeons harvesting bone from one area of the body, typically pelvis and transferring it to the fracture site. The amount of tissue available is therefore limited, requiring a second surgical procedure and often causing the patient long term pain. An alternative approach is utilise therapeutic cells contained within bone marrow aspirate during the primary procedure. The number of therapeutic cells within a fresh aspirate is insufficient to provide clinically acceptable bone healing in a timescale that is satisfactory to the surgeon and the patient. Therefore methods to efficiently concentrate bone marrow in the clinical setting are required. Centrifugation is the current method of choice but has limitations in that it requires large capital equipment, servicing and there are potential issues of tissue contamination. We have developed a novel, acoustically‐assisted filtration device that addresses these limitations, delivering a concentrated bone marrow in a point of care, single use, fully disposable, compact device. An additional advantage is that the level of concentration required can be specified by the end user. The resulting bone marrow concentrate has been characterised in terms of cell number, viability and osteogenic potential using flow cytometry and alkaline phosphatase assay. When compared to recent clinical studies using bone marrow to repair non‐union fractures, the findings from our work suggest that the bone marrow concentrate is likely to be highly therapeutic and clinically efficacious as a bone fracture repair strategy. A product concept for use in the clinical setting is presented. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Nanoporous protein matrix made of amyloid fibrils of β2‐microglobulin
Authors: Ahn Minkoo , Kang Sungsoo , Koo Hee Jung , Lee Jung‐Ho , Lee Yoon‐Sik , Paik Seung R.
Published: June 2010

Amyloid fibrils are considered as novel nanomaterials because of their nanoscale width, a regular constituting structure of cross β‐sheet conformation, and considerable mechanical strength. By using an amyloidogenic protein of β2‐microglobulin (β2M) related to dialysis‐related amyloidosis, nanoporous protein matrix has been prepared. The β2M granules made of around 15 monomers showed an average size of 23.1 nm. They formed worm‐like fibrils at pH 7.4 in 20 mM sodium phosphate containing 0.15 M NaCl following vigorous nondirectional shaking incubation, in which they became laterally associated and interwound to generate the porous amyloid fibrillar matrix with an average pore size of 30–50 nm. This nanoporous protein matrix was demonstrated to be selectively disintegrated by reducing agents, such as tris‐(2‐carboxyethyl) phosphine. High surface area with nanopores on the surface has been suggested to make the matrix of β2M amyloid fibrils particularly suitable for applications in the area of nanobiotechnology including drug delivery and tissue engineering. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Polymerization of human hemoglobin using the crosslinker 1,11‐bis(maleimido)triethylene glycol for use as an oxygen carrier
Authors: Zhang Ning , Palmer Andre F.
Published: June 2010

Vasoconstriction and systemic hypertension are the main side effects associated with transfusion of current commercial polymerized hemoglobins (PolyHbs). It is hypothesized that the presence of free tetrameric hemoglobin (Hb) in the PolyHb solution is the root cause of these side effects. Therefore, increasing the size of PolyHbs and reducing the amount of free Hb in solution should dually reduce the extent of vasoconstriction and systemic hypertension. However, all current commercial PolyHb preparations have a small fraction of free Hb in solution. Hence, there is an urgent need to develop novel chemical strategies to synthesize large PolyHb molecules with a higher degree of polymerization without free Hb in solution. In this study, a Hb‐based oxygen carrier was synthesized by polymerizing human Hb using a dimaleimide poly(ethylene glycol) derivative (1,11‐bis(maleimido)triethylene glycol). The resultant PolyHb has a weight‐averaged molecular weight of 1.49 ± 0.62 MDa, O2 affinity (P50) of 2.75 ± 0.55 mm Hg, and Hill coefficient (n) of 0.97 ± 0.07. Light scattering analysis of the PolyHb dispersion confirmed the absence of free Hb monomers, dimers, and tetramers in solution. This work is significant, as it should enable future engineering of nonvasoactive PolyHbs with potential applications in transfusion medicine. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Flow cytometric analysis of genetic FRET detectors containing variable substrate sequences
Authors: Hong Lim Kok , Hsu Cheng‐Kuo , Park Sheldon
Published: June 2010

A genetic Fluorescence Resonance Energy Transfer (FRET) detector undergoes a post‐translational modification (PTM)‐induced conformational change that results in increased FRET. To test if the PTM‐dependent FRET change can be quantified by flow cytometry, we purified and immobilized a genetic detector on microbeads and used flow cytometry to measure its FRET efficiency before and after Erk‐2–mediated phosphorylation. The fluorescence ratio R between the acceptor and donor fluorescence, which was obtained by fitting a straight line through the data points in linear space, increases following phosphorylation, thus demonstrating that flow cytometry is capable of detecting a PTM‐dependent FRET response. Furthermore, when Erk‐2 and a genetic detector are coexpressed in bacteria, the measured R value changes with the substrate sequence with near single residue resolution. Similarly, the cells coexpressing the glycosylating enzyme O‐GlcNAc transferase (OGT) and a genetic detector specific for OGT exhibit a PTM‐induced change in FRET efficiency. Therefore, the combination of flow cytometry and a genetic detector may be useful to characterize the substrate specificity of a PTM enzyme and identify the sequences that are preferentially targeted for PTM in vivo. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Preliminary results of the INSPIRE trial with the novel MGuard™ stent system containing a protection net to prevent distal embolization
Authors: Maia Felipe , Ribamar Costa J. , Abizaid Alexandre , Feres Fausto , Costa Ricardo , Staico Rodolfo , Siqueira Dimytri , Esteves Vinicius , Sousa Amanda , Eduardo Sousa J.
Published: June 2010

Objective: To assess the efficacy of the MGuardTM stent combining a polymer‐mesh sleeve attached to the external surface of a bare‐metal stent in preventing distal embolization during percutaneous coronary intervention (PCI). Background: Distal embolization of thrombus/platelet agreggates is associated with worse immediate and long‐term prognosis after PCI. Treatment of saphenous vein graft (SVG) and PCI in the setting of acute coronary syndromes (ACS) is often related to this complication. Although protection and aspiration devices have been shown to reduce distal embolization, they add time and cost to PCI. Methods: A total of 30 patients were included. Inclusion criteria were de novo lesions in SVG or native vessels with angiographic evidence of instability with potential to provoke flow disturbances and/or distal embolization. Primary endpoint included the incidence of major adverse cardiac events (MACE) (composite of cardiac death, non‐fatal myocardial infarction and TLR) up to 30 days of the procedure and TIMI flow right after the PCI. Results: Mean population age was 60.8 years with 36.7% of diabetes. Overall, 53.3% presented with ACS, and most lesions were located in SVG (16 of 30). The majority of lesions had complex morphology including the presence of thrombus (30%) and ulcer (33.3%). The MGuard stent was successfully deployed in all cases with no angiographic/clinical complications including distal embolization. Final TIMI‐3/blush‐3 were achieved in all cases with no MACE up to 30 days of the procedure. Conclusions: In this preliminary evaluation, the MGuard device demonstrated excellent performance in a highly complex lesion subset, including absence of angiograhpic/procedural complications, and no adverse events up to 30‐day FU. © 2010 Wiley‐Liss, Inc.
The EXTREME registry: Titanium‐nitride‐oxide coated stents in small coronary arteries
Authors: Valdesuso Raúl , Karjalainen Pasi , García Joan , Díaz José , Portales Javier Fernández , Masotti Mónica , Picó Francisco , Serra Antonio , Burgos José Moreu , Insa Luis , Mauri Fina , Collado Javier Rodriguez , Nammas Wail
Published: June 2010

Objectives: We sought to explore the immediate results of Titan2® stent implantation in small coronary arteries, as well as the incidence of major adverse cardiac events (MACE) at six months follow‐up. Background: The safety of Titan2® stent has been confirmed in several studies in real‐life unselected populations. Methods: We enrolled 311 consecutive patients admitted for percutaneous intervention for at least one significant (50%) de novo lesion in a native small coronary artery (2.0–2.75 mm). All lesions were treated with Titan2® stent implantation. Patients were prospectively followed up for at least six months. The primary endpoint was MACE at six months follow‐up [death, myocardial infarction (MI), or target vessel revascularization (TVR)]. Secondary endpoints included angiographic and clinical procedural success, in‐hospital MACE, target lesion revascularization (TLR) during follow‐up, and stent thrombosis. Results: The mean age was 67.3 ± 10.9 years (65.9% males). A total of 356 Titan2® stents were implanted in 353 lesions. Angiographic and clinical procedural success was achieved in 344 (97.5%) patients. No case of in‐hospital MACE or acute stent thrombosis was reported. Clinical follow‐up was completed for an average of 8 ± 2 months. Two patients (0.7%) died, and 6 (2.1%) developed MI. TLR was performed in 12 (4.2%) and TVR in 16 (5.5%) patients, all were clinically driven. Cumulative MACE occurred in 20 (6.9%) patients. One patient suffered subacute stent thrombosis, but no late stent thrombosis. Conclusions: Titan2® stent implantation in small coronary arteries achieves excellent immediate outcome, with a low incidence of MACE at mid‐term follow‐up. © 2010 Wiley‐Liss, Inc.
Impact of chronic renal insufficiency on clinical outcomes in patients undergoing saphenous vein graft intervention with drug‐eluting stents: A multicenter Southern Californian Registry
Authors: Lee Michael S. , Hu Patrick P. , Aragon Joseph , Shah Atman , Bhatia Ravi , Jones Nathaniel , Penny William , French William , Tobis Jonathan , Mahmud Ehtisham
Published: June 2010

Objectives: To evaluate the clinical outcomes in patients with chronic renal insufficiency (CRI) who undergo saphenous vein graft (SVG) intervention with drug‐eluting stents (DES). Background: Patients with CRI have higher rates of major adverse cardiac events (MACE) after percutaneous revascularization. SVG intervention is associated with increased rates of MACE compared with percutaneous revascularization of native arteries. However, the impact of CRI on SVG intervention with DES has not been well delineated. Methods: Consecutive patients who underwent SVG intervention with DES at five medical centers from April 2003 to December 2007 were included in this analysis. Results: A total of 172 patients, 39 patients with CRI and a serum creatinine ≥1.5 mg dL−1, and 133 patients without CRI, underwent SVG intervention with DES. Patients with CRI were more often older, diabetic, and had a longer mean total stent length. At 1 year, patients with CRI had a higher MACE rate (35.9% vs. 15.8%, hazard ratio [HR] 2.48, 95% confidence interval [CI] 1.26–4.88, log rank P = 0.009), mainly driven by higher mortality (20.5% vs. 9.8%, HR 3.41, 95% CI 1.10–10.58, log rank P = 0.024). There was a trend toward higher rates of target vessel revascularization in the CRI group (21.8% vs. 10.3%, HR 2.42, 95% CI 0.94–6.24, log rank P = 0.059). Stent thrombosis rates were not different between patients with and without CRI (2.6% vs. 2.3%, P = 0.8). Multivariable analysis revealed that CRI was the only significant predictor of 1‐year MACE (HR 2.2, 95% CI 1.1–4.3; P = 0.03). Conclusions: Patients with CRI who underwent SVG intervention with DES had higher risks of MACE and death compared with patients with preserved renal function. Further treatment strategies are needed in this high‐risk group who undergo SVG intervention with DES. © 2010 Wiley‐Liss, Inc.
A novel method of hybrid intraoperative catheter‐based closure of ventricular septal defects using the Amplatzer® PDA occluder
Authors: Neukamm Christian , Bjørnstad Per G. , Fischer Gunther , Smevik Bjarne , Lindberg Harald L.
Published: June 2010

Background: In five patients, an apical muscular septal defect was closed in a hybrid approach using the Amplatzer® duct occluder during open heart surgery, whereas concomitant defects were treated surgically. In addition to their different heart defects that needed surgery, all had a muscular ventricular septal defect in the apex of the heart, poorly accessible for traditional, surgical approach. We describe the method and outcome in these patients. Methods: The tip of a forceps was advanced from the left into the right ventricle through the ventricular septal defect. The delivery sheath was caught under visual control in the right ventricle and pulled back into the left ventricle. The disc was developed and pulled back until it was felt tugging at the septum. Then the core was developed. The end of the device was visible in the right ventricle and was secured with a Prolene® suture. Results: The procedures were event‐free. During early follow‐up there were either no or only insignificant shunts in the region of the prior trabecular defects in four patients. The unsatisfactory result in the last patient was caused by inaccurate preoperative assessment. Conclusion: The method seems valuable in patients in need of other intracardiac surgery. © 2010 Wiley‐Liss, Inc.
Intracardiac echocardiography off piste? Closure of the left atrial appendage using ICE and local anesthesia
Authors: MacDonald Simon T. , Newton James D. , Ormerod Oliver J.
Published: June 2010

Left atrial appendage (LAA) occlusion is increasingly accepted to reduce the risk of stroke in patients with atrial arrhythmia who are unsuitable for routine anticoagulation. It is generally performed under general anesthesia, guided by transoesophageal echocardiography with accurate imaging being essential for correct deployment of the device. We present a case where LAA occlusion was done under local anesthesia in a high‐anesthetic risk patient, using novel placement of an intracardiac echo probe via a Mullins sheath in the right ventricular outflow tract and pulmonary artery. This allowed accurate visualization of device deployment in the LAA. This technique may increase the spectrum of patients who may benefit from the procedure and decrease procedure time, fluoroscopy, and procedure‐related morbidity. © 2010 Wiley‐Liss, Inc.
Bailout perventricular pulmonary valve implantation following failed percutaneous attempt using the Edwards Sapien transcatheter heart valve
Authors: Cubeddu Roberto J. , Hijazi Ziyad M.
Published: June 2010

Percutaneous pulmonary valve implantation has emerged as an attractive and less invasive alternative to open‐heart surgery. Nevertheless, major technical challenges and procedural complications may still occur. We report a 44‐year‐old woman with severe dextroscoliosis, and history of Tetralogy of Fallot repair, who underwent an attempt at percutaneous implantation of a 23‐mm Edwards SAPIEN transcatheter heart valve (THV) for recurrent stenosis of the right ventricle to pulmonary artery conduit. The procedure was complicated by valve migration into the right ventricle requiring emergent surgical removal using inflow‐occlusion technique to avoid cardiopulmonary bypass. A hybrid off‐pump perventricular approach was then used in the operating room to successfully implant a 26‐mm Edwards Sapien THV under fluoroscopic guidance. © 2010 Wiley‐Liss, Inc.
Aortic annulus evaluation in transcatheter aortic valve implantation
Authors: Hutter Andrea , Opitz Anke , Bleiziffer Sabine , Ruge Hendrik , Hettich Ina , Mazzitelli Domenico , Will Albrecht , Tassani Peter , Bauernschmitt Robert , Lange Ruediger
Published: June 2010

Objectives: We compared the annulus diameters measured by transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and dual‐source computed tomography (DSCT) before transcatheter aortic valve implantation (TAVI). Background: In TAVI correct evaluation of the aortic annulus is mandatory to choose the correct prosthesis type and size and to prevent complications. There is no gold standard for the assessment of aortic annulus diameters. Methods: Preoperative assessment of the aortic annulus with TTE, TEE, and DSCT was performed in 187 consecutive patients referred for TAVI between June 2007 and May 2009. Results: The mean aortic annuli were 22.6 ± 2.0 mm measured with DSCT, 22.3 ± 2.5 mm with TTE, and 22.9 ± 2.2 mm with TEE. Despite a strong correlation between the measurement techniques, relevant statistical spread occurred with differences up to 3 mm in all measurement methods. Inter‐ and intraobserver variability was good for TEE and less satisfactory for DSCT measurements. TEE measurements taken as decisive parameter for the implantation changed the implantation strategy in 15.5% of patients and did not show an increased rate of procedural complications. Conclusion: Despite a strong correlation, the measurement techniques for the aortic annulus show relevant statistical spread, consequently one measurement technique cannot definitely predict another. TEE measurements show a more satisfactory intra‐ and interobserver variability than DSCT. Taking TEE annulus measurements as decisive parameter for the implantation has an impact on the implantation strategy and is safe with a low rate of procedural complications. © 2010 Wiley‐Liss, Inc.
Coronary angiography is a better predictor of mortality than noninvasive testing in patients evaluated for renal transplantation
Authors: Enkiri Sean A. , Taylor Angela M. , Keeley Ellen C. , Lipson Lewis C. , Gimple Lawrence W. , Ragosta Michael
Published: June 2010

Objectives: The goal of this study was to compare whether coronary angiography or noninvasive imaging more accurately identifies coronary artery disease (CAD) and predicts mortality in patients with end‐stage renal disease (ESRD) under evaluation for transplantation. Background: CAD is a leading cause of mortality in patients with ESRD. The optimal method for identifying CAD in ESRD patients evaluated for transplantation remains controversial with a paucity of prognostic data currently available comparing noninvasive methods to coronary angiography. Methods: The study cohort consisted of 57 patients undergoing both coronary angiography and stress perfusion imaging. Severe CAD was defined by angiography as ≥70% stenosis, and by noninvasive testing as ischemia in ≥1 zone. Follow‐up for all cause mortality was 3.3 years. Results: On noninvasive imaging, 63% had ischemia. On angiography, 40% had at least one vessel with severe stenoses. Abnormal perfusion was observed in 56% of patients without severe disease angiographically. Noninvasive imaging had poor specificity (24%) and poor positive predictive value (43%) for identifying severe disease. Angiography but not noninvasive imaging predicted survival; 3 year survival was 50% and 73% for patients with and without severe CAD by angiography (p<0.05). Conclusions: False positive scintigrams limited noninvasive imaging in patients with ESRD. Angiography was a better predictor of mortality compared with noninvasive testing. © 2010 Wiley‐Liss, Inc.
Percutaneous closure of a postero‐medial mitral paravalvular leak: The triple telescopic system
Authors: Yuksel Uygar Cagdas , Tuzcu E. Murat , Kapadia Samir R.
Published: June 2010

Paravalvular leaks (PVLs) still remain as a serious complication of heart valve surgery. The reported incidence of PVL is ∼ 3–12.5% and most of them become clinically manifest as worsening heart failure, hemolysis, and arrhythmias within the first 6 months. Surgical intervention is recommended for symptomatic patients, but high‐operative risk associated with the repeat procedures frequently prohibits the redo surgery for the older patients with multiple severe comorbidities. In view of the limitations of surgery, percutaneous closure techniques have been applied to PVLs with considerable achievement. However, the technique is still challenging due to the lack of specifically engineered instruments for the procedure and requires considerable operator expertise. In this case report, we presented a case of posteromedial mitral PVL, which was successfully closed using an innovative telescopic catheter system involving three different catheters. © 2010 Wiley‐Liss, Inc.
Stent malapposition caused by improper rewiring during left main intervention: The role of intravascular ultrasound in avoidance and management—A case report
Authors: Abdou Sayed M , Wu Chiung‐Jen
Published: June 2010

The optimal technique for bifurcation stenting of distal Left main (LM) lesions remains unestablished and controversial. Some techniques with superior stent apposition, such as culotte technique were supposed to be associated with lower rate of stent thrombosis. However, with culotte technique, the double‐stent layer at the carina and in the proximal part of the bifurcation, may lead to difficult or improper rewiring of the side branch before final kissing balloon postdilatation (KBP). We describe a case of distal LM disease associated with distal left circumflex (LCX) and posterior descending artery stenosis. During LM stenting using culotte technique, improper rewiring of LCX before final KBP caused malapposition of the inner sent layer at the mid part of LM. Despite the optimal angiographic result, intravascular ultrasound (IVUS) was able to detect stent malapposition and guided further management to achieve complete stent apposition. The present case indicates that IVUS is an essential tool for LM stenting particularly when applying double stent strategy requiring final rewiring before KBP. Moreover, we suggest that some tools, such as Crusade and Venture catheters, can be used to ensure proper rewiring and hence, prevent subsequent stent malapposition, which may lead to catastrophic complications such as early and late LM stent thrombosis. © 2011 Wiley‐Liss, Inc.
Impact of chronic total occlusions on markers of reperfusion, infarct size, and long‐term mortality: A substudy from the TAPAS‐trial
Authors: Lexis Chris P.H. , van der Horst Iwan C.C. , Rahel Braim M. , Lexis Monique A.S. , Kampinga Marthe A. , Gu Youlan L. , de Smet Bart J.G.L. , Zijlstra Felix
Published: June 2010

Objectives: This study evaluated the impact of a chronic total occlusion (CTO) in a non‐infarct related coronary artery (IRA) on markers of reperfusion, infarct size, and long‐term cardiac mortality in patients with ST‐elevation myocardial infarction (STEMI). Background: A concurrent CTO in STEMI patients has been associated with impaired left ventricular function and outcome. However, the impact on markers of reperfusion is unknown. Methods: All 1,071 STEMI patients included in the TAPAS‐trial between January 2005 and December 2006 were used for this substudy. Endpoints were the association between a CTO in a non‐IRA and myocardial blush grade (MBG) of the IRA, ST‐segment elevation resolution (STR), enzymatic infarct size, and clinical outcome. Results: A total of 90 patients (8.4%) had a CTO. MBG 0 or 1 occurred more often in the CTO group (34.2% versus 20.6% (Odds Ratio [OR] 2.00, 95% confidence interval [CI]: 1.22–3.23, P = 0.006)). Incomplete STR occurred more often in the CTO group, (63.6% versus 48.2% [OR 1.96, 95% CI: 1.22–3.13, P = 0.005]). Median level of maximal myocardial‐band of creatinin kinase (CK‐MB) in the CTO group was 75 μg/l (IQR 28‐136) and 51 μg/l (IQR 18–97) in the no‐CTO group (P = 0.021). The presence of a CTO in a non‐IRA in STEMI patients was an independent risk factor for cardiac mortality (HR 2.41, 95% CI: 1.26–4.61, P = 0.008) at 25 months follow‐up. Conclusion: A CTO in a non‐IRA is associated with impaired reperfusion markers and impaired long‐term outcome in STEMI patients. © 2010 Wiley‐Liss, Inc.
An Integrated Fouling Monitoring Technique for a Water Treatment Microfiltration Process
Authors: Chen W.‐H. , Hsieh Y.‐H. , Tung K. L. , Li Y. L. , Lai S. C. , Lin N. J.
Published: June 2010

An integrated, online fouling monitoring technique that provides dynamic and real‐time information of membrane fouling during a water treatment membrane process was developed. This technique has preliminarily been demonstrated for monitoring particulate fouling in a water treatment microfiltration process using a single photo sensor. The results of the online dynamic analysis suggest that this technique provides in situ measurement of fouling layer thickness, dynamic analysis of the fouling layer structure, and monitoring of water quality during the membrane filtration process.
Effect of Volume Fraction of Material on Separation by Density Difference in a Liquid‐Fluidized Bed of Inert Particles
Authors: Tatemoto Y. , Ishii A. , Suzuki Y. , Higashino T.
Published: June 2010

A liquid‐fluidized bed was used to separate a pure material from a mixture. A quantity of relatively large sized material was immersed in an inert‐particle fluidized bed and the behavior of materials was examined for different liquid velocities. In particular, the volume fraction of the material was varied and its effect on the separation characteristics was examined.

The material floats on the inert‐particle fluidized bed when the density of the material is lower than the apparent density of the bed, regardless of the volume fraction of the material. The apparent density of the bed can be adjusted by changing the liquid velocity. The materials in the upper portion of the bed affect the properties of the bed below them, i.e., the void fraction decreases and the apparent density increases in the inert‐particle suspension when materials are present in the upper portion of the bed. Therefore, the materials float on the bed although the apparent density of the inert‐particle suspension obtained from the case without material is less than the density of the material at a relatively high volume fraction of material. This phenomenon occurs more easily for lighter and smaller materials. This means that small inert particles and low liquid velocities are the optimum operating conditions for the separation.
Accelerated Formulation Development for Nanomilled Active Pharmaceutical Ingredients Using a Screening Approach
Authors: Juhnke M. , Berghausen J. , Timpe C.
Published: June 2010

In order to enable the accelerated preclinical and clinical pharmaceutical development of formulations based on nanomilling, a screening media mill was developed and evaluated for the production of nanoparticulate active pharmaceutical ingredients (API). The screening media mill is based on the principle of a conventional planetary mill, equipped with up to 24 milling beakers of 0.05–1.0 mL individual milling chamber volume. The applicability of the screening media mill was evaluated by 0.7–12.8 mg naproxen (2 wt %) per batch with a nanomilling formulation known from the literature. A case study for the preclinical formulation development is presented, applying 42 screening experiments by one operator within 5 working days, using in total 110 mg API. Promising nanomilling formulations with median particle sizes below 200 nm could be identified, suitable for preclinical in vivo studies. A second case study for the early clinical development of another proprietary API showed the successful formulation development within 12 working days. Up‐scaling to a miniaturized stirred media mill of 10 mL milling chamber volume resulted in a satisfying comparability of the selected formulations, with varying performance. Further up‐scaling of the most promising formulation to a laboratory‐scale stirred‐media mill showed the successful production of 250 g API with a median particle size of 140 nm.
Procedural Investigations of the Lautering Process
Authors: Tippmann J. , Scheuren H. , Voigt J. , Sommer K.
Published: June 2010

Beer production begins in the brewhouse, where milled malt is mixed with water. Relevant ingredients of the malt are converted and dissolved into wort. The solids have to be separated from the remaining liquid. This step is done in the lauter tun and is still a very time‐consuming process. Additionally, the procedural knowledge of this production step is still rather poor. Another aim in beer production is the evaporation of unwanted aroma compounds. Usually this is done during wort boiling. The latest research showed that the preliminary steps should be done before boiling. The developed system is the result of these two principles, evaporation of unwanted flavoring substances and prevention of blocking of the filter cake. The approach was the integration of a bubble generator in the lauter tun, which blows nitrogen bubbles (inert gas, not oxidizing) through the mash and filter cake.
Dead‐End Liposomal Electro‐Filtration: Phenol Removal by Dioctadecyl Dimethyl Ammonium Chloride as a Case Study
Authors: Hakimhashem M. , Saveyn H. , De Bock B. , Van der Meeren P.
Published: June 2010

Among the important efforts that have been made for the removal of trace organic molecules, sorption by micelles and subsequent membrane filtration is a promising method which, however, still suffers from a number of disadvantages such as low efficiency and high energy consumption. In this article, we present the results of the sorption of phenol (as an important trace organic pollutant in industrial wastewater) to dioctadecyl dimethyl ammonium chloride (DODAC) liposomes, as well as the filtration properties of the resulting dispersion. Whereas the sorption of phenol by a 0.5 wt % DODAC dispersion at neutral pH and ambient temperature was only 26–35 %, it increased to above 95 % at pH 11. Applying an electric field during the filtration process considerably improved both the filtrate flow rate and the retention. An electric field of 5 V/cm increased the filtrate flow rate at 200 kPa 30‐fold.
Persistent Mixed‐Valence [(TTF)2]+. Dyad of a Chiral Bis(binaphthol)–tetrathiafulvalene (TTF) Derivative
Authors: Saad Ali , Barrière Frédéric , Levillain Eric , Vanthuyne Nicolas , Jeannin Olivier , Fourmigué Marc
Published: June 2010

Mixed‐valence dyadic [(TTF)2]+. (TTF=tetrathiafulvalene) species—the elementary building blocks of organic conductors—are usually too weakly associated to be observed in solution, unless covalently bound in dimers or physically constrained into a cage structure. We demonstrate here that a novel chiral tetrathiafulvalene functionalised with two 1,1′‐binaphthol units (1) is able to associate in solution into persistent mixed‐valence [(TTF)2]+. dyadic moieties through a stereospecific recognition pattern. This redox active molecule exhibits different electrochemical and spectroscopic responses, as enantiopure RR, SS or meso isomers, a rare example of a chiral system in which different diastereoisomers do not exhibit the same electrochemical features, with a selective formation of the mixed‐valence species in the enantiopure (RR)‐1 or (SS)‐1 isomers only, whereas the meso form does not show this association ability. A rationale for the selective self‐association of the RR and SS enantiomers upon oxidation is provided, based on the different molecular geometries and accessibility of the TTF core toward the formation of the mixed‐valence species.
Car–Parrinello Molecular Dynamics Study of the Thermal Decomposition of Sodium Fulminate
Authors: Damianos Konstantina , Frank Irmgard
Published: June 2010

Depending on the metal cation, metal fulminates exhibit a characteristic sensitivity with respect to heat and mechanical stress. In the present paper we study the high‐temperature reactions of bulk sodium fulminate using Car–Parrinello molecular dynamics simulations. We find that the initiating reaction is the formation of the fulminate dimer, while in earlier studies an electron transfer was assumed to be the first reaction step. The initial carboncarbon bond formation is followed by fast consecutive reactions leading to polymerisation. The resulting species remain charged on the timescale of the simulations.