bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of integrating the elimination programme for lymphatic filariasis into primary health care in the Dominican Republic
Authors: Baker Margaret C. , McFarland Deborah A. , Gonzales Manuel , Diaz Mary Janet , Molyneux David H.
Published: August 2007

Integration of disease‐specific programmes into existing health care delivery systems is a challenge for many countries, made more salient as the scope and scale of disease‐specific programmes increases. This paper reports on the programmatic outcomes of 2 years of integrating the lymphatic filariasis (LF) elimination programme into primary health care (PHC) in the Dominican Republic during a period of national health care reform and decentralization. Data were collected retrospectively from community volunteers, PHC staff and LF programme staff using a mix of quantitative and qualitative methods. Benefits of integration for LF elimination included increasing the extent of the geographic coverage of mass drug administration (MDA) and a 21% increase in municipalities achieving the MDA target coverage rate of 80%. Benefits which accrued to PHC included improved information systems and strengthened relationships between the health services and the community. This study also identified challenges to implementing integration and the solutions found. These include the importance of focusing on the professional development of disease‐specific program staff as their roles change, strengthening specific weakness in the general health system and finding alternative solutions where these are not easily solved, actively engaging senior management at an early stage, continually evaluating the impact of integration and not pushing integration for the sake of integration. Copyright © 2007 John Wiley & Sons, Ltd.
Predicting unit plot soil loss in Sicily, south Italy
Authors: Bagarello V. , Di Piazza G. V. , Ferro V. , Giordano G.
Published: August 2007

Predicting soil loss is necessary to establish soil conservation measures. Variability of soil and hydrological parameters complicates mathematical simulation of soil erosion processes. Methods for predicting unit plot soil loss in Sicily were developed by using 5 years of data from replicated plots. At first, the variability of the soil water content, runoff, and unit plot soil loss values collected at fixed dates or after an erosive event was investigated. The applicability of the Universal Soil Loss Equation (USLE) was then tested. Finally, a method to predict event soil loss was developed. Measurement variability decreased as the mean increased above a threshold value but it was low also for low values of the measured variable. The mean soil loss predicted by the USLE was lower than the measured value by 48%. The annual values of the soil erodibility factor varied by seven times whereas the mean monthly values varied between 1% and 244% of the mean annual value. The event unit plot soil loss was directly proportional to an erosivity index equal to $Q_{\rm R}R_{\rm e}^{1{\cdot}609}$, being QRRe the runoff ratio times the single storm erosion index. It was concluded that a relatively low number of replicates of the variable of interest may be collected to estimate the mean for both high and particularly low values of the variable. The USLE with the mean annual soil erodibility factor may be applied to estimate the order of magnitude of the mean soil loss but it is not usable to estimate soil loss at shorter temporal scales. The relationship for estimating the event soil loss is a modified version of the USLE‐M, given that it includes an exponent for the QRRe term. Copyright © 2007 John Wiley & Sons, Ltd.
The performance of heteroskedasticity and autocorrelation robust tests: a Monte Carlo study with an application to the three‐factor Fama–French asset‐pricing model
Authors: Ray Surajit , Savin N. E.
Published: August 2007

This paper illustrates the pitfalls of the conventional heteroskedasticity and autocorrelation robust (HAR) Wald test and the advantages of new HAR tests developed by Kiefer and Vogelsang in 2005 and by Phillips, Sun and Jin in 2003 and 2006. The illustrations use the 1993 Fama–French three‐factor model. The null that the intercepts are zero is tested for 5‐year, 10‐year and longer sub‐periods. The conventional HAR test with asymptotic P‐values rejects the null for most 5‐year and 10‐year sub‐periods. By contrast, the null is not rejected by the new HAR tests. This conflict is explained by showing that inferences based on the conventional HAR test are misleading for the sample sizes used in this application. Copyright © 2007 John Wiley & Sons, Ltd.
Protein recognition via molecularly imprinted agarose gel membrane
Authors: Lin Yuan , Tang Shunqing , Mao Xuan , Bao Lei
Published: August 2007

Agarose gel membranes (AGMs), which could selectively recognize bovine serum albumin (BSA) and bovine hemoglobin (Hb), were prepared by molecular imprinting technique under moderate preparation conditions. Four imprinting processes, including gelation without any treatment, second gel‐melting, and two glutaraldehyde crosslinking processes of fumigation or direct addition of the crosslinking agent, were developed to investigate the protein‐recognition behavior of the AGMs. Results showed that the preparation processes affected the adsorption capacity and selectivity of the imprinted AGMs. Both BSA‐ and Hb‐imprinted AGMs exhibited higher adsorption abilities for the targeted proteins (3.77–5.72 times for BSA, 1.31–2.18 times for Hb) than the nonimprinted ones. And the selectivity of BSA‐imprinted AGMs for BSA molecules (the selective factor K = 3.29–4.90) was higher than that of Hb‐imprinted AGMs for Hb (K = 0.32–1.17). The optimal adsorption capacity of BSA‐ and Hb‐imprinted AGMs was 25.90 and 117.45 mg/g, respectively, when the membrane was crosslinked by glutaraldehyde with a fumigation process; the optimal selectivity of BSA‐ and Hb‐imprinted AGMs was 4.91 when the membrane was prepared by second gel‐melting process, and 0.76 when the membrane was prepared without any treatment. These findings demonstrate that the molecularly imprinted AGMs are hopeful to be used in specific protein analysis. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Oblique MR imaging of the anterior cruciate ligament based on three‐dimensional orientation
Authors: Breitenseher Martin J. , Mayerhoefer Marius E.
Published: August 2007

Purpose

To investigate the three‐dimensional (3D) course of the anterior cruciate ligament (ACL) and determine the optimum planes for oblique full‐length MRI of the ligament.

Materials and Methods

Twenty‐five healthy volunteers were examined. Axial proton density‐weighted (PDw) images of the knees of 20 volunteers were obtained. 3D paths along the course of the ACL and corresponding tangents were constructed. Angles between these tangents and reference lines RFL‐1 (the line connecting the posterior edges of the femoral condyles), RFL‐2 (the line through the intercondylar joint space), and RFL‐3 (the line connecting the anterior and posterior edge of the medial tibial condyle) were measured. These angles were used for oblique T2‐weighted (T2w) MRI of the knees of the remaining five volunteers, and the number of slices that depicted the entire ACL was calculated.

Results

The mean angles to the ACL were 74.0° for RFL‐1, 79.9° for RFL‐2, and 70.4° for RFL‐3. Full‐length visualization of the ACL was demonstrated by 1.4 slices using the sagittal oblique plane prescribed for RFL‐1, 2.4 slices using the sagittal oblique plane prescribed for RFL‐2, and 1.4 slices using the coronal oblique plane prescribed for RFL‐3.

Conclusion

The ACL is best depicted using a sagittal oblique imaging plane angled at 80° from a line through the intercondylar joint space. J. Magn. Reson. Imaging 2007;26:794–798. © 2007 Wiley‐Liss, Inc.
Relationship between the renal apparent diffusion coefficient and glomerular filtration rate: Preliminary experience
Authors: Xu Yufeng , Wang Xiaoying , Jiang Xuexiang
Published: August 2007

Purpose

To investigate the relationship between ADC values measured by diffusion‐weighted MRI (DWI) and the split glomerular filtration rate (GFR).

Materials and Methods

DWI (b = 0 and 500 seconds/mm2) was performed with a 1.5T MR unit in 55 patients. The ADCs were calculated with ROIs positioned in the renal parenchyma, and the split GFRs were measured by 99Tcm‐DTPA scintigraphy using Gates' method. The 110 kidneys were divided into four groups: normal renal function (GFR 40 mL · minute−1), mild renal impairment (40 > GFR ≥ 20 mL · minute−1), moderate renal impairment (20 > GFR ≥ 10 mL · minute−1), and severe renal impairment (GFR < 10 mL · minute−1). The renal ADCs between four groups were statistically compared by analysis of variance (ANOVA), and the relationship between ADCs and GFR was examined using Pearson's correlation test.

Results

The mean renal ADCs of the four groups were 2.87 ± 0.11, 2.55 ± 0.17, 2.29 ± 0.10, and 2.20 ± 0.11 × 10−3mm2/second, respectively. There was a statistically significant difference in renal ADCs among the four groups (P < 0.001). There was a positive correlation between the ADCs and split GFR (r = 0.709).

Conclusion

The ADCs were significantly lower in impaired kidneys than in normal kidneys, and there was a positive correlation between the ADCs and GFR. J. Magn. Reson. Imaging 2007;26:678–681. © 2007 Wiley‐Liss, Inc.
Diffusion‐weighted MR imaging of uterine endometrial cancer
Authors: Tamai Ken , Koyama Takashi , Saga Tsuneo , Umeoka Shigeaki , Mikami Yoshiki , Fujii Shingo , Togashi Kaori
Published: August 2007

Purpose

To determine the feasibility of diffusion‐weighted (DW) MRI of uterine endometrial cancer and to investigate whether the apparent diffusion coefficient (ADC) values of endometrial cancer differ from those of normal endometrium and whether they differ according to the histologic grade of the tumor.

Materials and Methods

Study population included 18 consecutive females with surgically proven endometrial cancer and 12 females with pathologically confirmed normal endometrium in cervical cancer patients. Visual evaluation and ADC measurement were performed in endometrial cancer and normal endometrium.

Results

All endometrial cancer and the normal endometrium appeared hyperintense on DW images. The mean ADC value (10−3 mm2/second) of endometrial cancer was 0.88 ± 0.16, which was significantly lower (P < 0.01) than that of normal endometrium (1.53 ± 0.10). The mean ADC value for each histologic grade was 0.93 ± 0.16 (G1), 0.92 ± 0.13 (G2), and 0.73 ± 0.09 (G3).

Conclusion

The present study showed that DW imaging is feasible in demonstrating uterine endometrial cancer and ADC measurement has a potential ability to differentiate between normal and cancerous tissue of the endometrium. The ADC values of endometrial cancers of higher grade show tendency to decrease compared to those of lower grade, although estimation of histologic grade based on ADC values seems difficult because of considerable overlap. J. Magn. Reson. Imaging 2007;26:682–687. © 2007 Wiley‐Liss, Inc.
T1 and T2 measurements of the fine structures of the in vivo and enucleated human eye
Authors: Patz Samuel , Bert Robert J. , Frederick Eric , Freddo Thomas F.
Published: August 2007

Purpose

To measure T1 and T2 of the fine structures of the in vivo eye.

Materials and Methods

Involuntary saccades make it difficult to obtain artifact‐free images. Using a method recently reported (Bert et al, Acad Radiol 2006;12:368–378), near artifact‐free spin‐echo images were obtained. Both an isolated enucleated eye and eight human subjects were studied at 1.5T. Spin‐echo variable TR/TE data was acquired for T1/T2 determination. Average relaxation times were calculated two ways. First, an arithmetic average over different subjects was computed. Second, all data was normalized using the fitted amplitudes of each data set and pooled to obtain a single least squares fit.

Results

In vivo T1/T2 (msec) are: arithmetic average T1, T2, normalized data T1, T2. Anterior chamber: 6233 ± 979, 468 ± 149, 5053 ± 1052, 450 ± 49. Ciliary body: 1916 ± 184, 80 ± 7, 2038 ± 114, 76 ± 3. Chorioretina: 1717 ± 500, 72 ± 25, 1511 ± 230, 78 ± 3. Extraocular muscle: 1581 ± 646, 41 ± 7, 1470 ± 231, 41 ± 1. Iris: 3334 ± 989, 163 ± 63, 3376 ± 338, 153 ± 10. Lens cortex: 1712 ± 466, 93 ± 36, 1413 ± 177, 100 ± 5. Lens nucleus: 1133 ± 40, 26 ± 3, 1138 ± 47, 25 ± 0.4. Optic nerve: 1906 ± 301, 68 ± 16, 1805 ± 244, 71 ± 2. Posterior chamber: 7915 ± 4897, 241 ± 14, 3323 ± 2154, 251 ± 38. Vitreous humor: 5768 ± 1190, 756 ± 804, 4855 ± 1846, 390 ± 8.

Conclusion

In vivo T1 and T2 for many of the fine structures of the human eye have been measured. J. Magn. Reson. Imaging 2007;26:510–518. © 2007 Wiley‐Liss, Inc.
Whole‐body MR imaging vs. FDG‐PET: Comparison of accuracy of M‐stage diagnosis for lung cancer patients
Authors: Ohno Yoshiharu , Koyama Hisanobu , Nogami Munenobu , Takenaka Daisuke , Yoshikawa Takeshi , Yoshimura Masahiro , Kotani Yoshikazu , Nishimura Yoshihiro , Higashino Takanori , Sugimura Kazuro
Published: August 2007

Purpose

To conduct a prospective comparison of the accuracy of whole‐body MR imaging and positron emission tomography (PET) with fluorine‐18 deoxyglucose (FDG) (FDG‐PET) to assess the M‐stage in lung cancer patients.

Materials and Methods

A total of 90 consecutive lung cancer patients (mean age = 68 years) underwent whole‐body MR imaging and FDG‐PET as well as other standard radiological imaging procedures before and after treatment. Probabilities of metastases on whole‐body MR imaging and FDG‐PET were assessed by using 5‐point scoring systems on a per‐site basis and on a per‐patient basis. Receiver operating characteristic (ROC) curve analysis was used to compare diagnostic capabilities. Sensitivity, specificity, and accuracy were also compared by using the McNemar's test on a per‐site and per‐patient basis.

Results

For assessment of head and neck metastases and bone metastases, accuracies of whole‐body MR imaging (95.0% and 94.8%, respectively) were significantly higher than those of FDG‐PET (89.1% and 88.2%, respectively; P < 0.05). For assessment of the M‐stage on a per‐patient basis, accuracy of whole‐body MR imaging (80.0%) was also significantly higher than that of FDG‐PET (73.3%; P < 0.05).

Conclusion

Whole‐body MR imaging is an accurate diagnostic technique and may be considered at least as effective as FDG‐PET for assessment of the M‐stage of lung cancer patients. J. Magn. Reson. Imaging 2007;26:498–509. © 2007 Wiley‐Liss, Inc.
Brain diffusivity in patients with neuropsychiatric systemic lupus erythematosus with new acute neurological symptoms
Authors: Welsh Robert C. , Rahbar Habib , Foerster Bradley , Thurnher Majda , Sundgren Pia C.
Published: August 2007

Purpose

To investigate the source of significant difference in apparent diffusion coefficient (ADC) between patients with acute symptoms of neuropsychiatric (NP) systematic lupus erythematosus (SLE) (NPSLE) and normal controls.

Materials and Methods

Diffusion‐weighted echo‐planar imaging was performed on 1.5‐T scanners in 17 female and four male NPSLE patients with acute neurological symptoms (23–76 years, mean = 42.7 years), and in 21 aged‐matched healthy controls (16 female, five male, 26–63 years, mean = 41.1 years). ADC histograms were calculated for whole brain, gray matter tissue, and white matter tissue.

Results

Of the 17 NPSLE patients, 13 (72%) had abnormal findings on MR imaging. The NPSLE patients had a mean ADC value of (1105.1 ± 23.6) × 10—6 mm2/second and the control had a mean ADC value of (1012.5 ± 9.4) × 10−6 mm2/second (P ≤ 0.0012). Significant differences were also found in white matter (P ≤ 0.0020) and gray matter (P ≤ 0.0022).

Conclusion

ADC histogram analysis demonstrated increased general diffusivity in the brain in NPSLE patients with acute symptoms compared with healthy normal controls. This finding suggests that in the brain parenchyma of NPSLE patients a loss of tissue integrity occurs facilitating motility of free‐water protons. J. Magn. Reson. Imaging 2007;26:541–551. © 2007 Wiley‐Liss, Inc.
High‐resolution MRI of the triangular fibrocartilage complex (TFCC) at 3T: Comparison of surface coil and volume coil
Authors: Bittersohl Bernd , Huang Thomas , Schneider Erika , Blazar Philip , Winalski Carl , Lang Philipp , Yoshioka Hiroshi
Published: August 2007

Purpose

To evaluate high‐resolution MRI of the triangular fibrocartilage complex (TFCC) at 3T using a surface coil (SC) or volume coil (VC).

Materials and Methods

MRI was obtained from nine volunteers in the supine position with a 3‐inch SC and in prone position with a transmit‐receiver wrist VC at 3T. Coronal two‐dimensional‐gradient echo (2D‐GRE) images (TR/TE/FA = 500 msec/15 msec/40°, 1 mm slice‐thickness, 60 mm field of view [FOV], 192 × 256 matrix) and coronal 3D‐GRE images (TR/TE/FA = 33 msec/15 msec/10°, 0.8 mm slice‐thickness, 80 mm FOV, 256 × 256 matrix) were used. Signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) of the TFCC and surrounding structures were measured. For qualitative measurement, visualization of TFCC and intercarpal ligaments was graded.

Results

SNR of TFCC, cartilage, and bone marrow on 2D‐GRE with SC/VC was as follows: 5.3/5.3 (TFCC), 16.5/14.4 (cartilage), and 3.61/3.96 (bone marrow). 3D‐GRE showed similar SNR. Cartilage‐TFCC/cartilage‐bone marrow CNR were 11.1/12.8 (SC‐2D‐GRE), 8.8/10.5 (VC‐2D‐GRE), 14.1/15.5 (SC‐3D‐GRE), and 11.9/15.0 (VC‐3D‐GRE). Quantitative values were not significantly different between SC and VC. Visualization of TFCC and intercarpal ligament with SC was superior to that with VC. All structures show higher scores with 3D‐GRE imaging compared to 2D‐GRE imaging.

Conclusion

SC may provide superior qualitative and quantitative results and can be an alternative in case of difficulty in prone position at 3T. J. Magn. Reson. Imaging 2007;26:701–707. © 2007 Wiley‐Liss, Inc.
Confounding effects of volatile anesthesia on CBV assessment in rodent forebrain following ethanol challenge
Authors: Luo Feng , Li Zhixin , Treistman Steven N. , Kim Young Ro , King Jean A. , Fox Gerard B. , Ferris Craig F.
Published: August 2007

Purpose

To compare and contrast the pattern and characteristics of the cerebral blood volume (CBV) response to ethanol (EtOH) in rats under awake and anesthetized conditions.

Materials and Methods

Acute EtOH (0.75 g/kg) challenge–induced CBV changes were measured using a contrast‐enhanced functional MRI CBV method in 15 male Sprague Dawley rats under three experimental conditions: 1.0% to 1.2% isoflurane (N = 5); 0.8% halothane (N = 5); and awake with no anesthetic (N = 5). Physiological parameters were collected from bench settings in nine rats from the above different conditions. Four parameters: 1) area under the curve (AUC%); 2) the maximum signal change (Max%); 3) EtOH absorption rate (α2); and 4) EtOH elimination rate (α1) were employed to compare EtOH‐induced MRI signals between the awake and anesthetized groups.

Results

Both awake and anesthetized animals responded with an increase in CBV to EtOH challenge. However, the presence of anesthesia promoted a significant preferential flow to subcortical areas not seen in the awake condition.

Conclusion

Unclear mechanisms of anesthesia add a layer of uncertainty to the already complex interpretation of EtOH's influence on neuronal activity, cellular metabolism, and hemodynamic coupling. J. Magn. Reson. Imaging 2007;26:557–563. © 2007 Wiley‐Liss, Inc.
Cepstral estimation of arterial input functions in brain perfusion imaging
Authors: Grüner Renate , Taxt Torfinn
Published: August 2007

Purpose

To investigate voxel‐specific arterial input functions (AIFs) obtained through blind deconvolution using complex cepstrum liftering. Blindly estimated AIFs have the potential of reducing dispersion effects in perfusion maps and are completely user‐independent.

Materials and Methods

The separability of AIFs and tissue residue functions (TRFs) in the cepstrum domain is exemplified using synthetic data, wherein the AIFs are modeled as gamma variate functions and the TRFs are modeled as exponential or linear functions. A novel separation filter is suggested. Initial results of different blind methods are illustrated using data from a stroke patient.

Results

The AIFs and the TRFs partly overlap in the complex cepstrum. The AIFs, obtained using the new separation filter, are closer to those obtained using noncepstral blind separation.

Conclusion

The overlap of AIFs and TRFs in the complex cepstrum makes reliable separation of the two functions more difficult than previously described. Comparison to noncepstral blind methods suggests that similar optima are found using the new separation filter. J. Magn. Reson. Imaging 2007;26:773–779. © 2007 Wiley‐Liss, Inc.
Identification of lignans by liquid chromatography‐electrospray ionization ion‐trap mass spectrometry
Authors: Eklund Patrik C. , Backman M. Josefin , Kronberg Leif Å. , Smeds Annika I. , Sjöholm Rainer E.
Published: August 2007

The fragmentation pattern of 30 compounds belonging to different classes of the lignan family was studied by liquid chromatography‐electrospray ionization ion‐trap mass spectrometry. On the basis of the observed fragmentation patterns, identification of different types of lignans was achieved. For example, dibenzylbutyrolactone lignans showed a characteristic fragmentation pathway by the loss of 44 Da (CO2) from the lactone moiety, whereas dibenzylbutanediols showed a loss of 48 Da by a combined loss of formaldehyde and water from the 1,4‐butanediol moiety. Lignan glycosides readily lost the sugar residue to give the parent lignan as their primary product ion. In addition, several compound‐specific fragmentations were observed and used for identification of individual compounds.

A versatile method for analyses of lignans was developed using LC separation on a C8 column followed by fragmentation and detection of ions produced in the ion trap. Copyright © 2007 John Wiley & Sons, Ltd.
Non‐Newtonian and thermal effects in constant flow valve compensated symmetric hole‐entry hybrid journal bearing
Authors: Garg H. C. , Kumar Vijay , Sharda H. B.
Published: August 2007

Every high speed machine, demanding high level of perfection, can operate successfully through a precise design of bearings. Such a design can be formulated after carefully studying both static and dynamic characteristics of the journal bearing. The present paper described the study of static and dynamic performance of a hole‐entry hybrid journal bearing system compensated with constant flow valve restrictor by considering the combined influence of thermal effects and non‐Newtonian behaviour of the lubricant. The variation of the viscosity due to the non‐Newtonian behaviour of the lubricant and temperature rise has been considered in the study. The numerical solution of the generalized Reynolds equation governing the flow of the lubricant, having variable viscosity along with the energy and heat conduction equations, was obtained using finite element method. The non‐Newtonian lubricant has been assumed to follow the cubic shear stress law. The study included the performance of a double row symmetric hole‐entry hybrid journal bearing configuration containing 12 holes per row. The results presented in this paper indicate that change in viscosity of lubricant affects the performance of the hole‐entry hybrid journal bearing system quite significantly. Copyright © 2007 John Wiley & Sons, Ltd.
Tailoring protective coatings for all‐oxide ceramic matrix composites in high temperature‐/high heat flux environments and corrosive media
Authors: Braue W. , Mechnich P.
Published: August 2007

The application range of porous all‐oxide ceramic matrix composites (CMCs) can be significantly extended through deposition of protective coating systems. Typical applications include protection against erosion, wear and foreign object damage as well as a reduced permeability. Environmental barrier coatings (EBC) are mandatory in order to guarantee sufficient lifetime of the CMC components under high temperature‐, high heat flux conditions and corrosive attack (combustor liners, thermal protection systems for atmospheric reentry). Limited thermal stability of today’s oxide fibers requires additional thermal barrier functionality for EBCs in order to keep the effective CMC bulk temperatures below 1200 °C. Depending on the specific application DLR’s coating concept for all‐oxide CMCs is based on either a single reaction‐bonded aluminium oxide (RBAO) coating or a hybrid coating system consisting of a RBAO bond coat followed by an EB‐PVD YSZ/FSZ top coat and is highlighted for three case studies. Deposition techniques (magnetron sputtering, MOCVD) alternative to EB‐PVD as well as the suitability of fibrous and cellular materials for thick EBC/TBC layers are explored.
Strain rate sensitivity of titanium matrix composites under tensile loading
Authors: Hausmann J. M.
Published: August 2007

Titanium matrix composites continuously reinforced by silicon carbide fibres are considered as key technology for a new generation of aero engines. High specific strength and stiffness promise significant weight savings and performance improvements. Impact loading may be one critical aspect in the design of rotating compressor components with titanium matrix composites. On the other hand the strength increases at high strain rates. Considering this additional loading capability enables a design closer to the edge. Therefore, the strength to strain rate relation needs to be examined. This paper presents results of high strain rate tests at the fly wheel device. Loadings resulting in strain rates from quasistatic loading to 740 1/s were applied. The results are discussed and the mechanism of energy consumption was investigated by determination of the plastic deformed length by scanning electron microscopy.
Biaxiale Ermüdung reibrührgeschweißter Strukturelemente
Authors: Biallas G. , Sick C. , Schneider J. , Trautmann K.‐H.
Published: August 2007

Im Rahmen des EU‐Projekts WelAir wurden Kreuzproben auf der biaxialen Prüfanlage des DLR zyklisch belastet. Die Proben wurden aus reibrührgeschweißten Überlappstößen hergestellt und enthielten versteifende Elemente. Um die reale Belastungssituation von innendruckbeaufschlagten Strukturen im Flugzeugrumpf nachzubilden, wurden proportionale, gleichphasige Belastungen aufgebracht, wobei das mit λ bezeichnete Verhältnis der Lasten in den beiden Beanspruchungsrichtungen variierte.

Die natürliche Rissinitiierung und das nachfolgende Risswachstum wurden vom Steifigkeitssprung am Nahtanfang und ‐ende bestimmt, die Risse bildeten sich dort jeweils senkrecht zur Naht aus. Die kleinste Lebensdauer wurde bei einachsiger Beanspruchung in Schweißrichtung (λ = 0) beobachtet. Zusätzliche Lastkomponenten senkrecht zur Schweißnaht (λ > 0) wirkten lebensdauerverlängernd. Ähnlich wie bei Stringerproben verlängerte eine größere Last senkrecht zum Stringer auch die Lebensdauer von reibrührgeschweißten Clip‐Stringer‐Strukturelementen, aber zusätzlich änderte sich die Lage des versagensrelevanten Risses.
Click chemistry reactions in medicinal chemistry: Applications of the 1,3‐dipolar cycloaddition between azides and alkynes
Authors: Tron Gian Cesare , Pirali Tracey , Billington Richard A. , Canonico Pier Luigi , Sorba Giovanni , Genazzani Armando A.
Published: August 2007

In recent years, there has been an ever‐increasing need for rapid reactions that meet the three main criteria of an ideal synthesis: efficiency, versatility, and selectivity. Such reactions would allow medicinal chemistry to keep pace with the multitude of information derived from modern biological screening techniques. The present review describes one of these reactions, the 1,3‐dipolar cycloaddition (“click‐reaction”) between azides and alkynes catalyzed by copper (I) salts. The simplicity of this reaction and the ease of purification of the resulting products have opened new opportunities in generating vast arrays of compounds with biological potential. The present review will outline the accomplishments of this strategy achieved so far and outline some of medicinal chemistry applications in which click‐chemistry might be relevant in the future. © 2007 Wiley Periodicals, Inc. Med Res Rev, 28, No. 2, 278–308, 2008
Laplacian decomposition of vector fields on fractal surfaces
Authors: Abreu‐Blaya R. , Bory‐Reyes J. , Moreno‐García T. , Peña‐Peña D.
Published: August 2007

In the present paper we consider domains in ℝ3 with fractal boundaries. Our main purpose is to study the boundary values of Laplacian vector fields, paying special attention to the problem of decomposing a Hölder continuous vector field on the boundary of a domain as a sum of two Hölder continuous vector fields which are Laplacian in the domain and in the complement of its closure, respectively. Our proofs are based on the intimate relationships between the theory of Laplacian vector fields and quaternionic analysis. Copyright © 2007 John Wiley & Sons, Ltd.
NMR and IR characterization of the aluminium complexes of norfloxacin and ciprofloxacin fluoroquinolones
Authors: Chattah Ana K. , Garro Linck Yamila , Monti Gustavo A. , Levstein Patricia R. , Breda Susana A. , Manzo Rubén H. , Olivera María E.
Published: August 2007

A set of new aluminium complexes of norfloxacin (NOR) and ciprofloxacin (CIP) that show an improvement in their pharmaceutical properties were studied using solution and solid‐state nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy. The complexes synthesized with two different methods were compared. One of these methods will allow formulation of the compounds at production scale. High‐resolution 13C spectra were obtained with the cross‐polarization and magic angle spinning (CP‐MAS) experiment. These spectra were assigned by comparing them with the solution data of the pure drug and by using a quaternary carbon edition technique. The carbon relaxation times in the rotating frame, T1ρC, were measured for all the complexes. A two‐exponential decay evidences that the complexes are nonhomogeneous. The short T1ρC values are in the range 320–1100 µs and the long values in the range 1.8–7 ms. 27Al MAS NMR spectra revealed an octahedral coordination between the aluminium ion and oxygens of the pure drug, supporting a 3:1 ligand:metal stoichiometry in both CIP and NOR complexes. The stretching and deformation modes of carboxylic acid and carboxylate and keto groups were analyzed by IR. This technique shows that the same modes are present in the aluminium complexes obtained by the two methods and that the coordination of the fluoroquinolone to aluminium occurs through the 4‐keto and 3‐carboxylic groups. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of airway diameter measurements from an anthropomorphic airway tree phantom using hyperpolarized 3He MRI and high‐resolution computed tomography
Authors: Tzeng Yang‐Sheng , Hoffman Eric , Cook‐Granroth Janice , Maurer Rie , Shah Niral , Mansour Joey , Tschirren Juerg , Albert Mitchell
Published: August 2007

An anthropomorphic airway tree phantom was imaged with both hyperpolarized (HP) 3He MRI using a dynamic projection scan and computed tomography (CT). Airway diameter measurements from the HP 3He MR images obtained using a newly developed model‐based algorithm were compared against their corresponding CT values quantified with a well‐established method. Of the 45 airway segments that could be evaluated with CT, only 14 airway segments (31%) could be evaluated using HP 3He MRI. No airway segments smaller than ∼4 mm in diameter and distal to the fourth generation were adequate for analysis in MRI. For the 14 airway segments measured, only two airway segments yielded a non‐equivalent comparison between the two imaging modalities, while eight more had inconclusive comparison results, leaving only four airway segments (29%) that satisfied the designed equivalence criteria. Some of the potential problems in airway diameter quantification described in the formulation of the model‐based algorithm were observed in this study. These results suggest that dynamic projection HP 3He MRI may have limited utility for measuring airway segment diameters, particularly those of the central airways. Magn Reson Med 58:636–642, 2007. © 2007 Wiley‐Liss, Inc.
Magnetically‐labeled sensitized splenocytes to identify glioma by MRI: A preliminary study
Authors: Arbab Ali S. , Rad Ali M. , Iskander A.S.M. , Jafari‐Khouzani Kourosh , Brown Stephen L. , Churchman Jamie L. , Ding Guangliang , Jiang Quan , Frank Joseph A. , Soltanian‐Zadeh Hamid , Peck Donald J.
Published: August 2007

This study investigated the feasibility of imaging the migration and incorporation of magnetically‐labeled sensitized splenocytes in an experimental 9L glioma brain tumor model. Splenocytes collected from tumor‐bearing (sensitized splenocytes) or control (nonsensitized splenocytes) host rats were analyzed to determine the population of different cells, labeled with ferumoxides‐protamine sulfate (FePro) and injected intravenously to recipient rats (N = 4, for each group) bearing intracranial 9L tumors. Day 3 postinjection of splenocytes multiecho T‐weighted and three‐dimensional (3D) gradient echo MRI were obtained using a 7 Tesla MR system. R (1/T) maps were created from the T‐weighted images. Signal intensities (SIs) and R values in the tumors and contralateral brain were determined by hand drawn regions of interest (ROIs). Brain sections were stained for the evidence of administered cells. Both 3D and T‐weighted MRI showed low signal intensity areas in and around the tumors in rats that received labeled sensitized splenocytes. Prussian blue (PB), CD45‐ and CD8‐positive cells were present in areas at the corresponding sites of low signal intensities seen on MRI. Rats that received labeled nonsensitized splenocytes did not show low signal intensity areas or PB positive cells in or around the implanted tumors. In conclusion, the immunogenic reaction can be exploited to delineate recurrent glioma using MRI following systemically delivered magnetically labeled sensitized splenocytes or T‐cells. Magn Reson Med 58:519–526, 2007. © 2007 Wiley‐Liss, Inc.
Contrast agent concentration measurements affecting quantification of bolus‐tracking perfusion MRI
Authors: Calamante Fernando , Vonken Evert‐jan P.A. , van Osch Matthias J.P.
Published: August 2007

Measurement of the concentration of the contrast agent using dynamic susceptibility contrast MRI relies on field inhomogeneities caused by the presence of the paramagnetic agent. The usual method for calculation of the concentration from dynamic T‐weighted images is based on two key assumptions: 1) a linear relation between the change in R and the contrast agent concentration, and 2) a negligible effect on the MR signal due to concurrent T1 changes. In this study the effect of inaccuracies in these two assumptions on perfusion measurements was investigated using simulations and in vivo data. The results of the simulations provide a quantitative characterization of the magnitude of these effects for various experimental conditions (e.g., when a 1‐sec TR is used with TE = 20 ms, the T1 effects can introduce up to 40% cerebral blood flow underestimation depending on the flip angle). These findings can be used as a guide to estimate the errors in specific practical implementaions, as well as to optimize the sequence parameters to minimize their effect. In summary, this study shows that the arterial input function measurement should be corrected for nonlinear R effects and that care should be taken in the study design to avoid introducing significant T1 effects in perfusion quantification. Magn Reson Med 58:544–553, 2007. © 2007 Wiley‐Liss, Inc.
Three‐dimensional cine imaging using variable‐density spiral trajectories and SSFP with application to coronary artery angiography
Authors: Kressler Bryan , Spincemaille Pascal , Nguyen Thanh D. , Cheng Liuquan , Xi Hai Zhao , Prince Martin R. , Wang Yi
Published: August 2007

A single breath‐hold 3D cardiac phase resolved steady‐state free precession (SSFP) sequence was developed, allowing 3D visualization of the moving coronary arteries. A 3D stack of spirals was acquired continuously throughout the cardiac cycle, and a sliding window reconstruction was used to achieve high temporal resolution. A coil specific field of view reconstruction technique was combined with Parallel Imaging with Localized Sensitivities (PILS) to allow acquisition of a reduced field of view. A view ordering incorporating fat suppression was employed to allow use of sliding window reconstruction. The technique was evaluated on healthy volunteers (n = 8), yielding images with 102 ms temporal resolution and 1.35 mm in‐plane resolution, and reasonable visualization of the left and right coronary arteries was achieved. Magn Reson Med 58:535–543, 2007. © 2007 Wiley‐Liss, Inc.
Fast, accurate, and precise mapping of the RF field in vivo using the 180° signal null
Authors: Dowell Nicholas G. , Tofts Paul S.
Published: August 2007

RF field B1 nonuniformity is the largest cause of error in the quantitative measurement of many clinically relevant parameters in MR images and spectra. Knowledge of the absolute flip angles at every region will improve the accuracy and precision of such parameters. This method uses the 180° signal null to construct a flip angle map of the entire brain in less than 4 min, independent of T1, T2, and proton density. Three spoiled gradient echo volume acquisitions of the whole brain were made with three different flip angles. The optimum choice of flip angles was determined to be 145°, 180°, and 215°. Linear regression analysis was used to determine the nominal (system calibrated) flip angle required for a signal null at every pixel and thence determine the absolute flip angle at that location. The experiment utilizes an existing MR sequence supplied by the scanner manufacturer. The technique is validated experimentally and a theoretical investigation into the optimum experimental parameters is presented. Magn Reson Med 58:622–630, 2007. © 2007 Wiley‐Liss, Inc.
Structure–function relations of the giant elastic protein titin in striated and smooth muscle cells
Authors: Granzier Henk , Labeit Siegfried
Published: August 2007

The striated muscle sarcomere contains, in addition to thin and thick filaments, a third myofilament comprised of titin. The extensible region of titin spans the I‐band region of the sarcomere and develops passive force in stretched sarcomeres. This force positions the A‐bands in the middle of the sarcomere, maintains sarcomere length homogeneity and, importantly, is responsible for myocardial passive tension that determines diastolic filling. Recent work suggests that smooth muscle expresses a truncated titin isoform with a short extensible region that is predicted to develop high passive force levels. Several mechanisms for tuning the titin‐based passive tension have been discovered that involve alternative splicing as well as posttranslational modification, mechanisms that are at play both during normal muscle function as well as during disease. Muscle Nerve, 2007
Phrenic nerve conduction studies: Technical aspects and normative data
Authors: Resman‐Gǎspěrsč Anita , Podnar Simon
Published: August 2007

In our clinical work we have occasionally encountered difficulties (e.g., no response, concomitant brachial plexus stimulation) in performing phrenic nerve conduction studies. The aim of this study was to overcome these difficulties and obtain our own set of normative data. In 29 healthy volunteers (15 men), aged 21–65 years, phrenic nerve conduction studies were performed using bipolar surface stimulation electrodes and a standard recording montage. Stimulation just above the clavicle, between the sternal and clavicular heads of the sternocleidomastoid muscles, elicited responses at the lowest stimulation strength, without concomitant brachial plexus stimulation. M‐wave amplitude and duration changed with respiration, whereas latency and area did not. The normative limit for M‐wave latency was 8.0 ms (upper), for amplitude it was 0.46/0.33 mV (lower: inspiration/expiration), and for area it was 4.4 mVms (lower). We suggest a slight modification of the generally used position for phrenic nerve stimulation, and the use of M‐wave latency and area (unaffected by the respiratory cycle) in future phrenic nerve conduction studies. Muscle Nerve, 2007
Effects of nandrolone on denervation atrophy depend upon time after nerve transection
Authors: Zhao Jingbo , Zhang Yuangfei , Zhao Weidong , Wu Yong , Pan Jiangping , Bauman William A. , Cardozo Christopher
Published: August 2007

Anabolic steroids prevent disuse atrophy and reverse atrophy caused by glucocorticoids. To determine whether these beneficial effects extend to denervation atrophy, we tested whether nandrolone blocked denervation atrophy acutely or reversed subacute denervation atrophy. We also tested the association of such anabolic effects with expression of MAFbx, MuRF1 (both of which accelerate denervation atrophy), and IGF‐1 (which prevents such atrophy). When begun at the time of denervation, nandrolone did not alter atrophy or expression of MAFbx, MuRF1, or IGF‐1 measured 3, 7, or 14 days thereafter. When nandrolone administration was begun 28 days after denervation, atrophy was significantly reduced 7 and 28 days later (16% and 30%, respectively), and this was associated with significant reductions in expression of MAFbx and MuRF1, without alterations in the expression of IGF‐1. The findings indicate that the actions of nandrolone depend on time after nerve transection and that the timing of anabolic steroid administration is an important determinant of responses of atrophying muscle to these agents. Muscle Nerve, 2007
Expression of transforming growth factor β1 gene, basic fibroblast growth factor gene and hydroxyproline in diabetes‐induced bladder dysfunction in a rat model
Authors: Yongzhi Li , Benkang Shi , Jianping Zhang , Lingxia Ran , Wei Bian , Yaofeng Zhu , Keqin Zhang , Laudon Vincent
Published: August 2007

Aims

To investigate the content of hydroxyproline (Hyp) and the expression of transforming growth factor beta1 (TGFβ1) and basic fibroblast growth factor (bFGF) in the bladder 8 weeks after diabetes induction.

Methods

Thirty wistar rats were divided into three groups: control (n = 10), streptozotocin‐induced diabetic group (n = 10), TAD group (n = 10; diabetic rats were fed with Tadenan100 mg kg−1 day−1). Eight weeks later, the bladders were dissected. RT‐PCR, immunohistochemistry, and ELISA were used to detect the expression of TGFβ1 and bFGF in the bladder. Also hydroxyproline (Hyp) was measured using a method based on alkaline hydrolysis.

Results

The content of hydroxyproline in the diabetic group was greater than that of control group (P < 0.05); we found significantly increased expression of TGFβ1 mRNA and bFGF mRNA in the bladder from the diabetic group compared with the control group; immunohistochemical and ELISA studies showed a statistically significant increased expression of TGFβ1 protein and bFGF protein in the bladder from the diabetic group compared with the control group (P < 0.05). The content of hydroxyproline in TAD group was less than that of diabetic group (P < 0.05); mRNA expression of TGFβ1 and bFGF greatly decreased in TAD group compared with that of the diabetic group; immunohistochemical and ELISA studies showed decreased levels of TGFβ1 protein and bFGF protein in the bladder from TAD group compared with the diabetic group (P < 0.05).

Conclusions

Rats with streptozoticin‐induced diabetes mellitus showed significant increase in hydroxyproline, TGFβ1 and bFGF levels in their bladders, which may be an important mechanism inducing diabetic cystopathy. Tadenan could effectively reduce hydroxyproline, TGFβ1, and bFGF levels. Neurourol. Urodynam. 27:254–259, 2008. © 2007 Wiley‐Liss, Inc.
Tandem duplications of MLL and FLT3 are correlated with poor prognoses in pediatric acute myeloid leukemia: A study of the Japanese childhood AML Cooperative Study Group
Authors: Shimada Akira , Taki Tomohiko , Tabuchi Ken , Taketani Takeshi , Hanada Ryoji , Tawa Akio , Tsuchida Masahiro , Horibe Keizo , Tsukimoto Ichiro , Hayashi Yasuhide
Published: August 2007

Background

Mixed‐lineage leukemia (MLL)‐partial tandem duplication (PTD) is associated with poor prognosis in adult acute myeloid leukemia (AML), but its relationship to pediatric AML is unknown.

Procedure

One hundred fifty‐eight newly diagnosed AML patients, including 13 FAB‐M3 and 10 Down syndrome (DS) patients, who were treated on the Japanese Childhood AML Cooperative Treatment Protocol AML 99 were analyzed for MLL‐PTD, as well as internal tandem duplication (ITD) and the kinase domain mutation (D835Mt) in the FLT3 gene.

Results

We found MLL‐PTD in 21 (13.3%) of 158 AML patients, but not in FAB‐M3 or DS patients. The differences between patients with and without MLL‐PTD were significant for 3‐year overall survival (OS) (56.3% vs. 83.2%, P = 0.018), disease‐free survival (DFS) (41.7% vs. 69.6%, P = 0.010), and relapse rate (RR) (54.3% vs. 27.6%, P = 0.0085) of 135 AML patients excluding the FAB‐M3 and DS patients. Furthermore, ITD and D835Mt in the FLT3 gene were found in 17 (12.6%) and 8 (5.9%) of these 135 patients, respectively. The differences between patients with FLT3‐ITD and the wild‐type allele were significant for 3‐year OS (35.3% and 84.3%, P < 0.0000001), DFS (40.0% and 66.9%, P < 0.003), and RR (52.4% and 30.3%, P < 0.005). Coduplication of both genes was found in only 3 (1.9%) patients.

Conclusion

AML patients with FLT3‐ITD, but not D835Mt, showed a poor prognosis. AML patients with MLL‐PTD were also correlated with poor prognosis in this study. Pediatr Blood Cancer 2008;50:264–269. © 2007 Wiley‐Liss, Inc.
Prevention and management of central venous catheter occlusion and thrombosis in children with cancer
Authors: Skinner Roderick , Koller Karin , McIntosh Nan , McCarthy Anthony , Pizer Barry
Published: August 2007

Background

The views and clinical practice of children's cancer units were surveyed regarding management of central venous catheter (CVC) occlusion (CVC‐occlusion), CVC‐related thrombosis (CVC‐thrombosis) and thromboembolism (CVC‐thromboembolism).

Procedure

A questionnaire was sent to all 22 United Kingdom Children's Cancer Study Group centres, requesting information about their views of the importance of, and their practices regarding, prophylaxis, diagnosis and treatment of CVC‐occlusion/thrombosis.

Results

Twenty (91%) centres responded. Eighty percent, 80% and 70%, respectively, stated that CVC‐occlusion, CVC‐thrombosis and CVC‐thromboembolism were clinically important concerns. All centres used heparinised saline flushes as prophylaxis against CVC‐occlusion, with little variation (≤30% centres) in frequency, volume and heparin concentration. Symptoms or signs suggesting partial CVC‐occlusion, total CVC‐occlusion, or CVC‐thrombosis/thromboembolism were always investigated in 20%, 55% and 85% of centres, respectively, but with considerable variability in the nature and sequence of investigations performed, which included (depending on the clinical scenario) chest X‐ray, contrast linography or venography, ultrasonography, echocardiography and magnetic resonance venography. A fibrinolytic lock was administered before investigation of CVC‐occlusion in 75% of centres. Although 45%, 60% and 80%, respectively, always treated partial CVC‐occlusion, total CVC‐occlusion or CVC‐thrombosis/thromboembolism, the type and order of treatments differed greatly between centres, especially for CVC‐thrombosis/thromboembolism, in which CVC removal, systemic anticoagulation (heparin or warfarin), local or systemic fibrinolysis, or thrombectomy were performed in at least some centres.

Conclusions

The clinical practice of UKCCSG centres regarding prevention, investigation and treatment of CVC‐occlusion/thrombosis varies greatly. Additional trials should facilitate development of evidence‐based guidelines. Pediatr Blood Cancer 2008;50:826–830. © 2007 Wiley‐Liss, Inc.