bluuebunny/crossref_metadata_2025 huggingface dataset:
Addressing risk in the design of new healthcare services: A step‐by‐step methodology
Authors: Remus Beth
Published: July 2009

New service design can be done effectively through enterprise risk management (ERM) by identifying the clinical and administrative risks within the new service design. This article proposes a 10‐step process describing the business team's tasks and integrating risk management, quality management and patient safety concepts.
Integrating disclosure, patient safety and risk management activities
Authors: Fasler Karen
Published: July 2009

National Quality Forum safe‐practice guidelines encourage hospitals to integrate disclosure, patient safety and risk management activities. Combining collaborative law with a patient safety program in a parallel process makes it possible to achieve this integration. This combination provides for physician‐led guidance in determining whether disclosure is required — and, if so, provides mentor assistance with actual disclosure. It offers proactive error prevention by offering a means to quickly utilize information to make safety changes. Additionally, the combination provides an opportunity to access collaborative law at a time when it is still possible to resolve issues without resort to litigation.
The ECG Dilemma: Guidelines on improving interpretation
Authors: Mele Paul F.
Published: July 2009

The “ECG Dilemma” was recognized by the American College of Cardiology (ACC) and the American Heart Association more than 10 years ago. Estimates put the number of patients suffering from significant ECG interpretation errors every year in the same range as deaths from diabetes. Missed MI ranks in the top tier of malpractice dollars lost. Guidelines have been put forth to reduce these losses and improve patient safety and quality of care. These guidelines, and suggestions towards implementing them, are discussed.
Preventing and responding to medical identity theft
Authors: Amori Geraldine
Published: July 2009

Medical identity theft is a crime with two victims: patients and providers. It is easy to commit and lucrative because healthcare record keeping and business interactions are complex and mainly electronic. Patients whose identity has been stolen are vulnerable to both medical error and financial loss. Providers may suffer both reputation loss and financial loss. There are steps to help prevent and to respond appropriately to medical identity theft.
3T versus 1.5T phased‐array MRI in the presurgical work‐up of patients with partial epilepsy of uncertain focus
Authors: Zijlmans Maeike , de Kort Gérard A.P. , Witkamp Theodore D. , Huiskamp Geertjan M. , Seppenwoolde Jan‐Henry , van Huffelen Alexander C. , Leijten Frans S.S.
Published: July 2009

Purpose

To study 3T compared to 1.5T phased array magnetic resonance imaging (MRI) in the presurgical work‐up of patients with epilepsy with complex focus localization.

Materials and Methods

In all, 37 patients (>10 years) in preoperative work‐up for epilepsy surgery were offered 3T in addition to 1.5T MRI if ambiguity existed about the epileptic focus. Scans were randomly reviewed by two observers, blinded for prior imaging, patient‐identifying information, and each other's assessments, followed by a consensus meeting. The number of abnormal scans, detected lesions, and interobserver agreement were calculated and compared. The final consensus was compared to original scan reports.

Results

One observer identified 22 lesions in both 3 and 1.5T scans, while the second identified more lesions in 1.5T scans (28 vs. 20). 3T MRI had better interobserver agreement. 3T revealed more dysplasias, while 1.5T revealed more tissue loss and mesial temporal sclerosis (MTS). The final consensus yielded 29 lesions, whereas original reports identified only 17 lesions.

Conclusion

The 3T scans revealed different lesions compared to 1.5T. Patients can benefit most from 3T scans when a dysplasia is suspected. Reevaluation by another experienced neuroradiologist is advised in case of negative or equivocal MRIs. J. Magn. Reson. Imaging 2009;30:256–262. © 2009 Wiley‐Liss, Inc.
Rapid production of specialized animal handling devices using computer‐aided design and solid freeform fabrication
Authors: Howles Gabriel P. , Nouls John C. , Qi Yi , Johnson G. Allan
Published: July 2009

Purpose

To develop a process for rapidly and inexpensively producing customized animal handling devices for small animal imaging.

Materials and Methods

To meet the specific needs of a particular imaging experiment, measurements are taken from imaging data and the animal handling devices are designed using 3D computer‐aided design (CAD) software. Parts are produced in a few days using solid freeform fabrication (SFF, a.k.a. rapid prototyping).

Results

This process is illustrated with the production of an animal handling system for stereotaxically prescribed therapeutic ultrasound and MRI of the mouse brain. The device provides integrated head‐fixation, anesthesia delivery, and physiological monitoring in a modular system. Design and production took ≈1 week and the cost was a small fraction of a traditional machine shop.

Conclusion

Commercial animal handling products typically have limited functionality and are not integrated with other laboratory infrastructure. However, using CAD and SFF, sophisticated animal handling devices can be produced to meet the specific experimental needs. This process is typically faster and less expensive than using a traditional machine shop, and the products are more robust than typical homemade devices. Using high‐quality purpose‐built devices permits experiments to be executed with greater consistency and higher throughput. J. Magn. Reson. Imaging 2009;30:466–471. © 2009 Wiley‐Liss, Inc.
MRI‐guided vacuum‐assisted breast biopsy: A phantom and patient evaluation of targeting accuracy
Authors: El Khouli Riham H. , Macura Katarzyna J. , Barker Peter B. , Elkady Laila M. , Jacobs Michael A. , Vogel‐Claussen Jens , Bluemke David A.
Published: July 2009

Purpose

To determine the spatial localization errors of magnetic resonance imaging (MRI)‐guided core biopsy for breast lesions using the handheld vacuum‐assisted core biopsy device in phantoms and patients.

Materials and Methods

Biopsies were done using a 10‐gauge handheld vacuum‐assisted core biopsy system (Vacora, Bard, AZ, USA) on a 1.5T MRI scanner (Philips Achieva, Best, The Netherlands). A standardized biopsy localization protocol was followed by trained operators for multiplanar planning of the biopsy on a separate workstation. Biopsy localization errors were determined as the distance from needle tip to center of the target in three dimensions.

Results

Twenty MRI‐guided biopsies of phantoms were performed by three different operators. The biopsy target mean size was 6.8 ± 0.6 mm. The overall mean three‐dimensional (3D) biopsy targeting error was 4.4 ± 2.9 mm. Thirty‐two MRI breast biopsies performed in 22 patients were reviewed. The lesion mean size was 10.5 ± 9.4 mm. The overall mean 3D localization error was 5.7 ± 3.0 mm. No significant differences between phantom and patients biopsy errors were found (P > 0.5).

Conclusion

MRI‐guided handheld vacuum‐assisted core biopsy device shows good targeting accuracy and should allow localization of lesions to within ∼5 to 6 mm. J. Magn. Reson. Imaging 2009;30:424–429. © 2009 Wiley‐Liss, Inc.
Multi‐echo acquisition of MR angiography and venography of the brain at 3 Tesla
Authors: Du Yiping P. , Jin Zhaoyang , Hu Yuzheng , Tanabe Jody
Published: July 2009

Purpose

To improve the visibility of veins in susceptibility‐weighted imaging (SWI) using a multi‐gradient echo acquisition.

Materials and Methods

A three‐dimensional multi‐echo gradient‐echo pulse sequence was developed for simultaneous acquisition of MR angiography and multiple volumes of MR venography (MRV) of the brain. The first echo was acquired for MR angiography using the time‐of‐flight in‐flow effect. The subsequent echoes were acquired for SWI‐based MRV at different echo times (TEs).

Results

Multiple MRV datasets acquired at different TEs were complementary in depicting the venous vasculature. MRV data acquired at a longer TE had a higher venous contrast and stronger susceptibility weighting, whereas MRV data acquired at a shorter TE had a higher signal‐to‐noise ratio and less severe off‐resonance artifacts. Three‐dimensional mapping of local field gradients was calculated and the transverse relaxivity (R2*) at each voxel was quantified using multi‐TE exponential fitting.

Conclusion

Multi‐echo acquisition of MR angiography and venography demonstrated improved visibility of venous vasculature especially in regions with severe field inhomogeneity compared with conventional acquisition of SWI and dual‐echo acquisition of MR angiography and venography. J. Magn. Reson. Imaging 2009;30:449–454. © 2009 Wiley‐Liss, Inc.
Accurate liver T measurement of iron overload: A simulations investigation and in vivo study
Authors: Beaumont Marine , Odame Isaac , Babyn Paul S. , Vidarsson Logi , Kirby‐Allen Melanie , Cheng Hai‐Ling Margaret
Published: July 2009

Purpose

To investigate the accuracy of T liver iron quantification using different curve‐fitting models under varying acquisition conditions, and to compare in iron‐overloaded patients the reliability of rapid T measurements against approved and slower T2 protocols.

Materials and Methods

Simulations were conducted to assess the influence of various factors on the accuracy of T measurement: curve‐fitting model, signal‐to‐noise ratio (SNR), and echo time (TE) spacing. Fifty‐four iron‐overloaded pediatric patients were assessed using a standard T2 and two variations of T acquisitions. In both simulations and in vivo data, three analysis models were evaluated: monoexponential, constant offset, and truncated.

Results

Simulations show the truncated model provides the best accuracy but is susceptible to underestimating high iron species under low SNR or high minimum TE. In contrast, the offset model tends to overestimate but maintains the most reliable measurements across the relevant range of iron levels. Furthermore, a much lower SNR can be tolerated if the acquisition uses a low minimum TE. In vivo results confirm theoretical findings and show that T measurements can be as reliable as those from approved and slower T2 protocols.

Conclusion

Guidelines are provided on choosing an appropriate model under specific noise conditions and acquisition schemes to ensure accurate and rapid T liver iron quantification. J. Magn. Reson. Imaging 2009;30:313–320. © 2009 Wiley‐Liss, Inc.
High‐field MRSI of the prostate using a transmit/receive endorectal coil and gradient modulated adiabatic localization
Authors: Near Jamie , Romagnoli Cesare , Curtis Andrew T. , Klassen L. Martyn , Izawa Jonathan , Chin Joseph , Bartha Robert
Published: July 2009

Purpose

To demonstrate in vivo magnetic resonance spectroscopic imaging (MRSI) of the human prostate at 4.0T using a transmit/receive endorectal coil and a pulse sequence designed specifically for this application.

Materials and Methods

A solid, reusable endorectal probe was designed for both radiofrequency transmission and reception. Finite difference time domain (FDTD) simulations were performed to characterize the coil's electric field distribution, and temperature measurements were performed in a beef tissue phantom to determine the coil's safe operating limit. The localization by selective adiabatic refocusing (LASER) pulse sequence was implemented using six gradient modulated offset independent adiabatic (GOIA) pulses for very sharp, B1‐insensitive voxel localization.

Results

Based on the simulations and temperature measurements, the coil's safe operating limit was conservatively estimated to be 1.0W for 15 minutes. The transition width of the GOIA pulse selection profiles was only 6% of the bandwidth, compared with 22% for a specific absorption rate (SAR)‐matched conventional adiabatic pulse. Using the coil and pulse sequence described here, MRSI data were successfully acquired from a patient with biopsy‐proven prostate cancer, with a nominal voxel size of 0.34 cc in a scan time of 15 minutes.

Conclusion

This work demonstrates the safe and effective use of a transmit/receive endorectal coil for in vivo MRSI of the prostate. J. Magn. Reson. Imaging 2009;30:335–343. © 2009 Wiley‐Liss, Inc.
Modulated repetition time look‐locker (MORTLL): A method for rapid high resolution three‐dimensional T1 mapping
Authors: Gai Neville D. , Butman John A.
Published: July 2009

Purpose

To demonstrate a modification of the Look‐Locker (LL) technique that enables rapid high resolution T1 mapping over the physiologic range of intracranial T1 values, ranging from white matter to cerebrospinal fluid (CSF). This is achieved by use of a three‐dimensional (3D) balanced steady‐state free precession (b‐SSFP) acquisition (for high signal‐to‐noise and resolution) along with variable repetition time to allow effective full recovery of longitudinal magnetization.

Materials and Methods

Two modifications to the Look‐Locker technique were made to realize high resolution imaging in a clinically reasonable scan time. The 3D b‐SSFP acquisition after an initial inversion pulse was followed by a variable repetition time. This technique makes it possible to image a volume of thin contiguous slices with high resolution and accuracy using a simple fitting procedure and is particularly useful for imaging long T1 species such as CSF. The total scan time is directly proportional to the number of slices to be acquired. The scan time was reduced by almost half when the repetition time was modified using a predesigned smooth function. Phantoms and volunteers were imaged at different resolutions on a 3 Tesla scanner. Results were compared with other accepted techniques.

Results

T1 values in the brain corresponded well with full repetition time imaging as well as inversion recovery spin echo imaging. T1 values for white matter, gray matter, and CSF were measured to be 755 ± 10 ms, 1202 ± 9 ms, and 4482 ± 71 ms, respectively. Scan times were reduced by approximately half over full repetition time measurements.

Conclusion

High resolution T1 maps can be obtained rapidly and with a relatively simple postprocessing method. The technique is particularly well suited for long T1 species. For example, changes in the composition of proteins in CSF are linked to various pathologies. The T1 values showed excellent agreement with values obtained from inversion recovery spin‐echo imaging. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Mediastinal lymph nodes: Assessment with diffusion‐weighted MR imaging
Authors: Koşucu Polat , Tekinbaş Celal , Erol Muharrem , Sari Ahmet , Kavgaci Halil , Öztuna Funda , Ersöz Şafak
Published: July 2009

Purpose

To prospectively determine whether the diffusion‐weighted magnetic resonance imaging is useful to distinguish between malignant and benign mediastinal lymph nodes.

Materials and Methods

Thirty‐five patients (14 women, 21 men; mean age 52 years) with 91 lymph nodes in the mediastinum detected by computed tomography underwent 1.5 Tesla (T) diffusion‐weighted MR imaging before mediastinoscopy (n = 29) and mediastinotomy (n = 6). Diffusion‐weighted MR images were acquired with a b factor of 50, and 400 s/mm2 using single‐shot echo‐planar sequence.

Results

Of the 35 patients, 18 had diagnosis of malignant tumor. Of the 18 patients with tumor, 8 had nonsmall cell carcinoma, and 10 had small cell carcinoma. Ninety‐one mediastinal lymph nodes were detected in the 35 untreated patients: 19 were pathologically diagnosed as metastatic lymph nodes, and 72 lymph nodes were diagnosed as nonmetastatic lymph nodes, including 50 sarcoidosis, 14 reactive lymphoid hyperplasia, and 8 necrotizing granulamatous lymphadenitis. The apparent diffusion coefficient (ADC) was significantly lower in metastatic lymph nodes (1.012 ± 0.025 × 10−3 mm2/s; P < 0.0005) than in benign lymph nodes (1.511 ± 0.075 × 10−3 mm2/s). On the ADC map, malignant nodes showed hyperintense (n = 2, 10.52%), hypointense (n = 14, 73.68%), and mixed intensity (n = 3; 15.78%), whereas benign nodes showed hyperintense (n = 57; 79.16%), hypointense (n = 3; 41.6%), isointense (n = 6; 8.33%), and mixed intensity (n = 6; 8.33%).

Conclusion

Diffusion‐weighted MR with ADC value and signal intensity can be useful in differentiation of malignant and benign mediastinal lymph nodes. J. Magn. Reson. Imaging 2009;30:292–297. © 2009 Wiley‐Liss, Inc.
Simultaneous temperature and magnetization transfer (MT) monitoring during high‐intensity focused ultrasound (HIFU) treatment: Preliminary investigation on ex vivo porcine muscle
Authors: Peng Hsu‐Hsia , Huang Teng‐Yi , Tseng Wen‐Yih Isaac , Lin En‐Li , Chung Hsiao‐Wen , Wu Chih‐Ching , Wang Yu‐Shun , Chen Wen‐Shiang
Published: July 2009

Purpose

To measure temperature change and magnetization transfer ratio (MTR) simultaneously during high‐intensity focused ultrasound (HIFU) treatment.

Materials and Methods

This study proposed an interleaved dual gradient‐echo technique to monitor the heat and tissue damage brought to the heated tissue. The technique was applied to tissue samples to test its efficacy.

Results

Ex vivo experiments on the porcine muscle demonstrated that both temperature changes and MTR exhibited high consistency in localizing the heated regions. As the heat dissipated after the treatment, the temperature of the heated regions decreased rapidly but MTR continued to be elevated. Moreover, thermal dose (TD) maps derived from the temperature curves demonstrated a sharp margin in the heated regions, but MTR maps may show a spatial gradient of tissue damage, suggesting complimentary information provided by these two measures.

Conclusion

In a protocol of spot‐by‐spot heating over a large volume of tissue, MTR provides additional values to mark the locations of previously heated regions. By continuously recording the locations of heated spots, MTR maps could help plan the next target spots appropriately, potentially improving the efficiency of HIFU treatment and reducing undesirable damage to the normal tissue. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Quantitative MRI measurement of lung density must account for the change in T with lung inflation
Authors: Theilmann Rebecca J. , Arai Tatsuya J. , Samiee Ahsan , Dubowitz David J. , Hopkins Susan R. , Buxton Richard B. , Prisk G. Kim
Published: July 2009

Purpose

To evaluate lung water density at three different levels of lung inflation in normal lungs using a fast gradient echo sequence developed for rapid imaging.

Materials and Methods

Ten healthy volunteers were imaged with a fast gradient echo sequence that collects 12 images alternating between two closely spaced echoes in a single 9‐s breathhold. Data were fit to a single exponential to determine lung water density and T. Data were evaluated in a single imaging slice at total lung capacity (TLC), functional residual capacity (FRC), and residual volume (RV). Analysis of variance for repeated measures was used to statistically evaluate changes in T and lung water density across lung volumes, imaging plane, and spatial locations in the lung.

Results

In normal subjects (n = 10), T (and [lung density/water density]) was 1.2 ± 0.1 msec (0.10 ± 0.02), 1.8 ± 0.2 ms (0.25 ± 0.04), and 2.0 ± 0.2 msec (0.27 ± 0.03) at TLC, FRC, and RV, respectively. Results also show that there is a considerable intersubject variability in the values of T.

Conclusion

Data show that T in the lung is very short, and varies considerably with lung volume. Thus, if quantitative assessment of lung density within a breathhold is to be measured accurately, then it is necessary to also determine T. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Fast left ventricular mass and volume assessment in mice with three‐dimensional guide‐point modeling
Authors: Young Alistair A. , Barnes Hannah , Davison Dan , Neubauer Stefan , Schneider Jurgen E.
Published: July 2009

Purpose

To investigate the accuracy (vs. standard manual analysis) and precision (scan–rescan reproducibility) of three‐dimensional guide‐point modeling (GPM) for the assessment of left ventricular (LV) function in mice.

Methods

Six male wildtype C57/Bl6 mice (weight 26.2 ± 1.1 g) were scanned twice, 3 days apart. Each scan was performed twice, at 0.2 mm/pixel with one average and at 0.1 mm/pixel with two averages. The 24 studies were anonymized and analyzed in blinded fashion using GPM and standard manual slice summation.

Results

The average error between GPM and standard analysis was 2.3 ± 5.8 mg in mass, 1.7 ± 3.2 μL in end‐diastolic volume, 2.3 ± 3.1 μL in end‐systolic volume, −2.7 ± 4.3% in ejection fraction, −0.6 ± 3.3 μL in stroke volume, and −0.31 ± 1.56 ml · min−1 in cardiac output (mean difference ± SD of differences, n = 24). The average time taken was 8.0 ± 2.5 minutes for 3D GPM and 48.5 ± 8.9 minutes for standard analysis (n = 24). Scan–rescan reproducibility results were similar to the standard analysis. No significant differences were found using linear mixed effects modeling in either accuracy or precision between scan resolutions or analysis method.

Conclusion

3D GPM enables fast analysis of mouse LV function, with similar accuracy and reproducibility to standard analysis. An image resolution of 0.2 mm/pixel with one average is adequate for LV function studies. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Examination of wind storms over Central Europe with respect to circulation weather types and NAO phases
Authors: Donat Markus G. , Leckebusch Gregor C. , Pinto Joaquim G. , Ulbrich Uwe
Published: July 2009

The occurrence of wind storms in Central Europe is investigated with respect to large‐scale atmospheric flow and local wind speeds in the investigation area. Two different methods of storm identification are applied for Central Europe as the target region: one based on characteristics of large‐scale flow (circulation weather types, CWT) and the other on the occurrence of extreme wind speeds. The identified events are examined with respect to the NAO phases and CWTs under which they occur. Pressure patterns, wind speeds and cyclone tracks are investigated for storms assigned to different CWTs. Investigations are based on ERA40 reanalysis data.

It is shown that about 80% of the storm days in Central Europe are connected with westerly flow and that Central European storm events primarily occur during a moderately positive NAO phase, while strongly positive NAO phases (6.4% of all days) account for more than 20% of the storms. A storm occurs over Central Europe during about 10% of the days with a strong positive NAO index. The most frequent pathway of cyclone systems associated with storms over Central Europe leads from the North Atlantic over the British Isles, North Sea and southern Scandinavia into the Baltic Sea. The mean intensity of the systems typically reaches its maximum near the British Isles. Differences between the characteristics for storms identified from the CWT identification procedure (gale days, based on MSLP fields) and those from extreme winds at Central European grid points are small, even though only 70% of the storm days agree. While most storms occur during westerly flow situations, specific characteristics of storms during the other CWTs are also considered. Copyright © 2009 Royal Meteorological Society
Changes in volatile composition during fruit development and ripening of ‘Alphonso’ mango
Authors: Pandit Sagar S , Kulkarni Ram S , Chidley Hemangi G , Giri Ashok P , Pujari Keshav H , Köllner Tobias G , Degenhardt Jörg , Gershenzon Jonathan , Gupta Vidya S
Published: July 2009

BACKGROUND: Volatile blends of five developing and five ripening stages of mango (Mangifera indica L. cv. Alphonso) were investigated along with those of flowers and leaves. Raw and ripe fruits of cv. Sabja were also used for comparison.

RESULTS: A total of 55 volatiles belonging to various chemical classes such as aldehydes, alcohols, mono‐ and sesquiterpene hydrocarbons, lactones and furanones were identified. In all Alphonso tissues monoterpenes quantitatively dominated, with 57–99% contribution; in particular, (Z)‐ocimene was found in the highest amount. Ripeness was characterized by the de novo appearance of lactones and furanones in the blend of monoterpenes. Sabja was distinguished by the abundance of monoterpene hydrocarbons in the raw fruit, and that of sesquiterpene hydrocarbons and their derivatives in the ripe stage.

CONCLUSION: Various stages of the Alphonso fruit during transition from flower to ripe fruit are characterized by unique volatile signatures that are distinguished from each other by the qualitative and quantitative appearance of different volatile compounds. Thus volatiles can be highly informative markers while studying the development and ripening of mango. Copyright © 2009 Society of Chemical Industry
Chemical and sensory stability of fried‐salted peanuts flavored with oregano essential oil and olive oil
Authors: Olmedo Rubén H , Asensio Claudia , Nepote Valeria , Mestrallet Marta G , Grosso Nelson R
Published: July 2009

BACKGROUND: Synthetic antioxidants, such as BHA, BHT and PG, are used in many foods to prevent rancidity. However, their health safety is questioned. There is renewed interest in the increased use of naturally occurring antioxidants such as essential oils from aromatic plants. The objective of this work was to evaluate the effect of oregano essential oil and olive oil on the oxidative stability of fried‐salted peanuts.

RESULTS: Fried‐salted peanuts (FP), fried‐salted peanuts with oregano essential oil (FP‐O) and fried‐salted peanuts with oregano essential oil and olive oil (FP‐OO) were prepared. Peroxide value (PV), p‐anisidine value (AV) and conjugated diene (CD) measurements, and descriptive analysis were analyzed on the products during 112 days of storage. FP‐OO showed higher stability during storage. PV and AV at the end of storage were lower in FP‐OO (57.70–7.77, respectively) followed by FP‐O (63.94–8.30) and FP (76.38–9.33, respectively). The oxidized and cardboard flavor intensities increased more in FP during storage than the other products while the roasted peanutty flavor also decreased more in FP.

CONCLUSION: Oregano essential oil and olive oil showed protective effect against lipid oxidation in fried‐salted peanuts increasing the shelf‐life of this product. Copyright © 2009 Society of Chemical Industry
Modeling of protein breakthrough performance in cryogel columns by taking into account the overall axial dispersion
Authors: Yun Junxian , Kirsebom Harald , Galaev Igor Yu , Mattiasson Bo
Published: July 2009

A model considering the overall axial dispersion for describing protein adsorption and breakthrough in monolithic cryogel beds has been developed. The microstructure of cryogels was characterized by tortuous capillaries with a normal diameter distribution but a constant pore wall thickness. The axial dispersion within cryogel columns was described by using the overall axial dispersion coefficient, which can be easily obtained by matching the experimental breakthrough curves without adsorption or measuring residence time distributions (RTDs). Experimental breakthrough curves of lysozyme within a metal‐chelated affinity cryogel by Persson et al. (Biotechnol. Bioeng. 2004, 88, 224–236) and a cation‐exchange cryogel by Yao et al. (J. Chromatogr. A 2007, 1157, 246–251) were employed as examples to test the model. The results showed that by using the axial dispersion coefficient and assuming uniform radial concentration profile at a given cross‐section of the cryogel along the bed height, the model can describe the detailed behaviors of the in‐bed overall axial dispersion, the in‐pore mass transfer, as well as the protein adsorption and breakthrough. For a known overall axial dispersion coefficient, the lumped parameter of the mass transfer coefficient between the bulk liquid and the capillary wall can be determined by fitting the protein breakthrough curve at a known chromatographic condition. Once this parameter is determined, the model can be used to predict the protein breakthrough profiles under different conditions based on the basic physical parameters of the cryogel bed and the properties of the fluid and protein. The effective capillary diameters employed in the model are close to the actual pore sizes observed from the images by SEM. The model predictions of lysozyme breakthrough profiles at various flow rates are also in good agreement with the experimental data in both the metal‐chelated affinity and cation‐exchange cryogel columns.
Affinity Study of Novel Gelatin Cell Carriers for Fibronectin
Authors: Van Vlierberghe Sandra , Vanderleyden Els , Dubruel Peter , De Vos Filip , Schacht Etienne
Published: July 2009

In the present work, the gelatin/fibronectin affinity was evaluated using SPR, QCM and radiolabelling. The results indicate that type A gelatin films possess a higher affinity for Fn compared to type B gelatin. This is due to a combined hydrophobic and electrostatic interaction between gelatin type A and Fn. In a second part, the affinity of Fn for porous gelatin scaffolds was evaluated. The scaffolds were prepared by a cryogenic treatment and subsequent freeze‐drying yielding type I and type II scaffolds which possess different pore geometries/sizes. The results indicate that the Fn density on the scaffolds can be fine‐tuned by varying the Fn concentration, the gelatin type (A vs. B), the pore size/geometry (type I vs. type II scaffolds).

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Electrospun Composite Mats of Poly[(D,L‐lactide)‐co‐glycolide] and Collagen with High Porosity as Potential Scaffolds for Skin Tissue Engineering
Authors: Yang Ye , Zhu Xinli , Cui Wenguo , Li Xiaohong , Jin Yan
Published: July 2009

Electrospun composite mats of poly[(D,L‐lactide)‐co‐glycolide] and collagen with high porosities of 85–90% and extended pore sizes of 90–130 µm were prepared to mimic the ECM morphologically and chemically. The existence of collagen molecules on the fiber surface was confirmed, enabling the cells to find enhanced binding sites for their integrin receptors. The mechanical data for the blended fibrous mats indicated that they were sufficiently durable for dermal tissue engineering. Fibroblasts derived from GFP transgenic C57BL/6 mice were used to directly observe cell proliferation, and the inoculation of collagen enhanced cell attachment, proliferation and extracellular matrix secretion, which were found to be dependent on the amount of collagen in the composite scaffold.

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Preparation of Composite Polymer Particles by Seeded Dispersion Polymerization in Ionic Liquids
Authors: Minami Hideto , Yoshida Kazuhiro , Okubo Masayoshi
Published: July 2009

Summary: Submicron‐sized monodisperse PS particles were prepared by dispersion polymerization of styrene in ionic liquids with poly(vinylpyrrolidone) as stabilizer. Seeded dispersion polymerization of MMA was subsequently carried out with PS seeds in [Bmim][BF4] to prepare PS/PMMA composite particles. Observation of the obtained particles of ultrathin cross‐sections with a scanning and transmission electron microscope revealed that no secondary nucleation occurred during the seeded dispersion polymerization and that the particles have a core‐shell morphology consisting of a PS core and a PMMA shell. Successful preparation of PS/PMMA composite particles in an ionic liquid has thus been demonstrated. Moreover, PS/PAA (PS‐core/PAA‐shell) composite particles were prepared by seeded dispersion polymerization in [DEME][TFSI], illustrating that hydrophobic/hydrophilic composite particles can be readily prepared in the ionic liquid.
Monodisperse Particles Based on Copolymers of Methyl methacrylate or Styrene with N‐Vinylformamide
Authors: Menshikova Anastasia , Evseeva Tatiana , Shevchenko Natalya , Shabsels Boris , Yakimansky Alexander , Ivanchev Sergey
Published: July 2009

Sammary: Various techniques of one‐step batch emulsion copolymerization of methyl methacrylate (MMA) or styrene (St) with N‐vinylformamide (NVF) initiated by 2,2′‐azobis(2‐methylpropanamidine) (AIBA) or 2,2′‐azobis[4,5‐dihydroimidazol‐2‐yl] (AIP) dihydrochlorides in the presence of dextran, cetyltrimethylammonium bromide (CTAB) or without any stabilizers were examined to obtain monodisperse submicron and nano‐ particles, having both positive surface charge and hydrophilic surface. After hydrolysis in acidic media, the particle surface contained amino groups originating from NVF units along with carboxylic groups from hydrolyzed initiator residues. The obtained particles were tested as building blocks of hierarchic structures. Owing to their amphiphilic surface, the particles were capable of self‐assembling from their dispersions into three‐dimentional (3D) ordered arrays.
Monodisperse Magnetic Polymeric Composite Particles for Biomedical Applications
Authors: Lu Shulai , Ramos Jose , Forcada Jacqueline
Published: July 2009

Summary: Magnetic polymeric composite particles (MPCPs) were prepared by miniemulsion polymerization of styrene in the presence of hydrophobic magnetic nanoparticles with hexadecane (HD) as hydrophobe, 2,2′‐azobisisobutyronitrile (AIBN), and sodium dodecyl sulfate (SDS) as an emulsifier or sodium p‐styrenesulfonate (NaSS) as an ionic comonomer. The hydrophobic magnetite particles with an average of about 10 nm were prepared by acidification of the water‐based magnetite ferrofluid, previously synthesized by a chemical coprecipitation method. The results show that miniemulsion polymerization is an effective method for encapsulation of magnetite into a hydrophobic polymer. Exposed magnetite particles and pure polymer particles can be avoided by selection of appropriate preparation conditions.
Hydrophilic Microspheres Containing αα‐tert Butoxy‐ωω‐vinylbenzyl‐polyglycidol for Immunodiagnostics: Synthesis, Properties and Biomedical Applications
Authors: Basinska Teresa , Krolik Sylwia , Slomkowski Stanislaw
Published: July 2009

Summary: Synthesis, characteristics and medical diagnostic application of core‐shell poly(styrene/α‐tert‐butoxy‐ω‐(vinylbenzyl)polyglycidol) (P(S/PGL)) microspheres are described. The particles were prepared by soap‐free emulsion polymerization of styrene and α‐tert‐butoxy‐ω‐(vinylbenzyl)polyglycidol macromonomer (PGL) initiated with potassium persulfate. The polymerization in water yielded microspheres with diameters in the range from 220 to 650 nm, depending on concentration of the macromonomer. Polydispersity was usually below 1.06. The fraction of PGL in interfacial layer of microspheres ranged from 0 to 42 mol.% (estimated by XPS). Microspheres suspended in NaCl solutions manifested fully reversible swelling‐deswelling properties of their interfacial layer with characteristic transition temperature (Tt) slightly dependent on NaCl concentration. The adsorption of human serum albumin on the surface of P(S/PGL) microspheres was highly reduced when the PGL surface fraction exceeded 40 mol.%. P(S/PGL) microspheres with immobilized antigens Helicobacter pylori were used for detection of antibodies against. The test was based on monitoring differences in electrophoretic mobility of P(S/PGL) microspheres covalently bound H. pylori antigens and antibodies against H. pylori in blood serum.
Encapsulation of Local Anesthetic Bupivacaine in Biodegradable Poly(DL‐lactide‐co‐glycolide) Nanospheres: Factorial Design, Characterization and Cytotoxicity Studies
Authors: Moraes Carolina Morales , de Lima Renata , Rosa André Henrique , de Paula Eneida , Fraceto Leonardo Fernandes
Published: July 2009

Summary: Local anesthetic agents cause temporary blockade of nerve impulses productiong insensitivity to painful stimuli in the area supplied by that nerve. Bupivacaine (BVC) is an amide‐type local anesthetic widely used in surgery and obstetrics for sustained peripheral and central nerve blockade. In this study, we prepared and characterized nanosphere formulations containing BVC. To achieve these goals, BVC loaded poly(DL‐lactide‐co‐glycolide) (PLGA) nanospheres (NS) were prepared by nanopreciptation and characterized with regard to size distribution, drug loading and cytotoxicity assays. The 23‐1 factorial experimental design was used to study the influence of three different independent variables on nanoparticle drug loading. BVC was assayed by HPLC, the particle size and zeta potential were determined by dynamic light scattering. BVC was determined using a combined ultrafiltration‐centrifugation technique. The results of optimized formulations showed a narrow size distribution with a polydispersivity of 0.05%, an average diameter of 236.7 ± 2.6 nm and the zeta potential −2.93 ± 1,10 mV. In toxicity studies with fibroblast 3T3 cells, BVC loaded‐PLGA‐NS increased cell viability, in comparison with the effect produced by free BVC. In this way, BVC‐loaded PLGA‐NS decreased BVC toxicity. The development of BVC formulations in carriers such as nanospheres could offer the possibility of controlling drug delivery in biological systems, prolonging the anesthetic effect and reducing toxicity.
pH‐ and Ionic‐Strength‐Induced Structural Changes in Poly(acrylic acid)‐Lipid‐Based Self‐Assembled Materials
Authors: Crisci Anthony , Hay Daniel N. T. , Seifert Sönke , Firestone Millicent A.
Published: July 2009

Summary: The effect of a polyanion introduced as a lipid conjugate (poly(acrylic acid)‐ dimyristoyl‐sn‐glycero‐3‐phosphoethanolamine, PAA‐DMPE) on the structure of a self‐assembled, biomembrane mimetic has been evaluated using synchrotron small‐angle X‐ray scattering (SAXS). At high grafting density (8–11 mol.%), the PAA chains were found to produce significant changes in structure in response to changes in pH and electrolyte composition. At low pH and in the absence of salt (NaCl), the neutral PAA chains adopt a coil conformational state that leads to the formation of a swollen lamellar structure. Upon the addition of salt at low to intermediate pH values, two lamellar phases, a collapsed and an expanded structure, coexist. Finally, when the polymer is fully ionized (at high pH), the extended conformation of the polymer generates a cubic phase. The results of this study contribute to an understanding of how polyelectrolytes may ultimately be harnessed for the preparation of self‐assembling materials responsive to external stimuli.
A Novel Estimation Method of the Distribution of Carboxyl Groups Within Copolymer Particles Using Isothermal Titration Calorimeter
Authors: Suzuki Toyoko , Yanagisawa Miyuki , Okubo Masayoshi
Published: July 2009

Summary: A novel quantitative method using isothermal titration calorimeter (ITC) for the estimation of the distribution of carboxyl groups within polymer particles has been proposed. The method has been employed to clarify the difference in the distribution between the particles prepared by batch emulsion copolymerization of styrene and methacrylic acid under inefficient and efficient stirring conditions. At inefficient stirring, monomer was floating as a layer on the aqueous medium, whereas at efficient stirring, the monomer phase was dispersed as droplets. Under inefficient stirring, methacrylic acid (MAA) polymerized faster than styrene (S) due to a slower diffusion rate of S than MAA into the aqueous medium, while under efficient stirring, S and MAA copolymerized at similar rates. ITC measurement showed that under inefficient stirring, the carboxyl groups were distributed mainly in the center of the particles, and their number decreased toward the surface. On the other hand, under efficient stirring, carboxyl groups were distributed homogeneously inside the particle.
Functionalised Microgels for Acrylic Coatings
Authors: Machotová Jana , Šňupárek Jaromír
Published: July 2009

Summary: Aqueous acrylic dispersions of hydroxy‐functionalised copolymer microgel particles crosslinked with allyl methacrylate were synthesized by emulsion polymerization. The microgels were investigated as reactive polymer fillers in mixtures with a water‐borne film‐forming dispersion. Properties of coatings cast from mixtures of aqueous dispersion of hard microgel particles and film‐forming water‐borne dispersion were investigated. The swelling behaviour of microgels in selected solvents (aliphatic ketones) as a function of microgel composition is discussed as well. It was found that the swelling ability of microgels decreased with growing degree of crosslinking. Microgels comprising copolymerised butyl methacrylate swelled less in aliphatic ketones than microgels without this comonomer. This work was focused mainly on the influence of microgels incorporated in the commercial solvent‐borne acrylic binders on the properties of coatings. It was shown that the application of microgels that were redispersed in acetone did not affect the surface appearance and transparency of coatings. Moreover, the presence of microgel network precursors accelerated film curing at ambient temperature and improved the final hardness of coatings.
Detection and climatology of fronts in a high‐resolution model reanalysis over the Alps
Authors: Jenkner J. , Sprenger M. , Schwenk I. , Schwierz C. , Dierer S. , Leuenberger D.
Published: July 2009

The identification of low‐level thermal fronts is particularly challenging in high‐resolution model fields over complex terrain. Firstly, direct model output often contains numerical noise which spuriously influences the high‐frequency variability of thermal parameters. Secondly, the boundary layer interferes via convection and consequently leaves its thermal marks on low levels. Here, an automated objective method for the detection of frontal lines is introduced which is designed to be insusceptible to consequences of small grid spacings. To this end, existing algorithms are readopted and combined in a novel way. The overall technique subdivides into a basic detection of fronts and a supplemental division into local fronts and synoptic fronts. The fundamental parts of the detection are: (1) a smoothing of the initial fields, (2) a definition of the frontal strength, and, (3) a localisation with the thermal front parameter. The local fronts are identified by means of a classification of open and closed thermal contours. The resulting data comprise the spatial outline of the frontal structures in a binary field as well as their type and movement. The novel methodology is applied to a 3 year high‐resolution reanalysis over central Europe computed with the COSMO model using a grid spacing of 7 km. Grid‐point based climatologies are derived for the Alpine region. Frequencies of occurrence and characteristics of motion are analysed for different frontal types. The novel climatology also provides quantitative evidence of dynamical properties such as the retardation of cold fronts ahead of mountains and the dissolution of warm fronts over mountains. Copyright © 2009 Royal Meteorological Society
Effect of gate‐to‐source capacitance of high‐power Si‐LDMOS FET on the asymmetrical intermodulation and modulation bandwidth of base‐station amplifiers
Authors: Chung Younkyu
Published: July 2009

This letter presents the effect of the gate‐to‐source capacitance (Cgs) on the imbalance of the intermodulation distortion (IMD) and modulation bandwidth of Si‐LDMOS field effect transistor (FET) high‐power base‐station PAs. It is revealed that the strong Cgsnonlinearity at the input gate of the LDMOS significantly contributes to the output intermodulation imbalance and plays an important role in determining the modulation bandwidth. The Volterra series analysis is used to qualitatively understand and describe the mechanism. The frequency‐sensitive baseband impedance, which is presented to Cgsand is proven to be one of the main factors to the imbalance in the analysis, is experimentally changed by manipulating the bias circuitry. The output IMD imbalance behavior is examined with two‐tone signals for the PA with the MRF5S18060 Si‐LDMOS FET. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2448–2451, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24597
Prediction of radiated EMI from PCB excited by switching noise of IC
Authors: Park Hyun Ho , Jung Jin‐Hwan , Jang Tae‐Sun , Han Sang‐Tae , Song Seung‐Hyun , Park Jae‐Jin , Park Hark‐Byeong
Published: July 2009

This article describes a methodology to predict radiated emission from the printed circuit boards (PCBs) excited by switching noise of integrated circuits (ICs). Radiation characteristics of PCBs were simulated by using commercial 3D full‐wave softwares. IC's switching noise was obtained by measurement. The radiated emission can be calculated by these two factors. To verify the calculation, test PCBs composed of power and ground plane were designed and measured in a 3 m semi‐anechoic chamber. The calculated radiated emission showed a good agreement with the measured results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2262–2266, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24603
Wideband coupled‐fed PIFA for HAC penta‐band clamshell mobile phone
Authors: Chen Wei‐Yu , Wong Kin‐Lu
Published: July 2009

A wideband coupled‐fed PIFA suitable for application in the clamshell mobile phone for achieving WWAN operation and meeting hearing‐aid compatibility (HAC) standard ANSI C63.19‐2007 is presented. The coupled‐fed PIFA is formed by two coupled strips (a longer one and a shorter one) capacitively fed by a common feeding strip, all printed on a thin 0.8‐mm FR4 substrate and folded into a small size of 6 × 5.8 × 45 mm3(about 1.6 cm3). The coupled‐fed PIFA is mounted at the hinge of the clamshell mobile phone and provides a very wide operating band of about 1.5 GHz (from about 0.8–2.3 GHz) to cover the penta‐band operation of GSM850/900/1800/1900/UMTS. With the wideband operation obtained, the radiated E‐field and H‐field strengths on the 50 × 50 mm2observation plane centered 15 mm above the center of the acoustic output of the clamshell mobile phone are evaluated to be in the M3 or M4 Category, making the mobile phone as a hearing‐aid compatible communication device. The clamshell mobile phone with the coupled‐fed PIFA also meets the SAR (specific absorption rate) limit of 1.6 W/kg for the 1‐g head tissue. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2369–2374, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24620
Modulated backscatter microwave security sensor
Authors: Cantú Horacio I. , Fusco Vincent F.
Published: July 2009

A system capable of deployment as a microwave security sensor which can automatically reject background clutter is presented. The principle of operation is based on analog homodyne detection using I, Q single side‐band down conversion of an AM backscattered modulating signal envelope. A demonstrator is presented which operates with a carrier frequency of 2 GHz and 500 KHz backscattered signal. When deployed in a multipath rich open plan office environment the S/N ratio obtained at the detection output was better than 20 dB at 20 m range with 20 dBm EIRP in a 2 MHz detection bandwidth despite the presence of time varying and static clutter. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2492–2495, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24636