bluuebunny/crossref_metadata_2025 huggingface dataset:
A low complexity selected mapping scheme for peak to average power ratio reduction with digital predistortion in OFDM systems
Authors: Mohammady S. , Sidek R. M. , Varahram P. , Hamidon M. N. , Sulaiman N.
Published: September 2011

One of the effective methods used for reducing peak‐to‐average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems is selected mapping (SLM). In this paper, a new SLM scheme called DSI‐SLM, which is a combination of dummy sequence insertion (DSI) and conventional selected mapping (C‐SLM) is proposed. Previous techniques have had some drawbacks. In DSI, increasing the number of dummy sequences to have better PAPR degrades transmission efficiency, and in C‐SLM, the complexity rises dramatically when the number of sub‐blocks increases. The proposed DSI‐SLM scheme significantly reduces the complexity because of the reduction in the number of sub‐blocks compared with the C‐SLM technique while its PAPR performance is even better. To enhance the efficiency of the OFDM system and suppress the out‐of‐band distortion from the power amplifier nonlinearity, a digital predistortion technique is applied to the DSI‐SLM scheme. Simulations are carried out with the actual power amplifier model and the OFDM signal based on the worldwide interoperability for microwave access standard and quadrature phase‐shift keying modulation. The simulation results show improvement in PAPR reduction and complexity, whereas the BER performance is slightly worse. Copyright © 2011 John Wiley & Sons, Ltd.
Contactless Conductivity Detection of 14 Inorganic Cations in Mineral and Phytotherapeutic Formulations after Capillary Electrophoretic Separation
Authors: de Carvalho Leandro M. , Raabe Alice , Martini Mariele , Sant'anna Carla S. , da Silveira Géssica D. , do Nascimento Paulo C. , Bohrer Denise
Published: September 2011

This work describes the separation and determination of 14 inorganic cations (NH4+, K+, Ca2+, Na+, Mg2+, Mn2+, Tl3+, Cr3+, Pb2+, Cd2+, Zn2+, Cu2+, Co2+, and Ni2+) as nutrients and contaminants in mineral and phytotherapeutic samples. The separated species were detected by capacitively coupled contactless conductivity detection (C4D) using working electrolytes based on 30 mmol L−1 2‐N‐morpholinoethanesulfonic acid (MES)/histidine, 1.5 mmol L−1 18‐crown‐6 ether, and 1 mmol L−1 citric acid (pH 6.0) as complexing additives for co‐migrating cations. The methodology was evaluated and validated for the cations and it was found to be reliable for determining inorganic cations in samples of mineral fertilizers and medicinal plants used in the phytotherapy.
Insight into Amyloid Formation Using Congo Red as the Electrochemical Probe
Authors: Veloso Anthony J. , Chan Tiffiny , Wing Sze Hung Vinci , Lam Leayen , Kerman Kagan
Published: September 2011

The amyloid‐β (Aβ) aggregation pathway is an important target for the discovery of drugs that can prevent or delay the onset of Alzheimer’s disease (AD). The electrochemistry of Congo Red (CR) represents a particularly promising tool for screening of Aβ‐binding therapeutics in a rapid and cost‐effective format. The results of the differential pulse voltammetry (DPV) measurements were confirmed using simultaneous UV‐vis analysis of the same incubated Aβ samples. The early changes in the electrochemical signals were attributed to the interaction of the Aβ oligomers with CR. The electrochemical approach, in principle, allowed monitoring small molecule‐Aβ interactions on the time scale of aggregation.
Terpenoids isolated from Tunisian Nigella sativa L. essential oil with antioxidant activity and the ability to inhibit nitric oxide production
Authors: Bourgou Soumaya , Pichette André , Lavoie Serge , Marzouk Brahim , Legault Jean
Published: September 2011

Fractionation of the essential oil from the seeds of Nigella sativa (Ranunculaceae) led to the isolation of four terpenoids: trans‐ (1), cis‐sabinene hydrate methyl ether (2), 1,2‐epoxy‐menth‐4‐ene (3) and 1,2‐epoxy‐menth‐4(8)‐ene (4). Structure elucidation was performed using NMR (1D and 2D NMR) experiments and mass spectral data. Compounds 3 and 4 are reported for the first time as natural products. Bioactivities of the compounds were assessed. The four compounds exhibit antioxidant activity in vitro, as assessed by the oxygen radical absorbance capacity test. Moreover, compounds 1, 2 and 4 displayed strong ability to inhibit oxidative stress in human skin WS‐1 fibroblasts cells, with IC50 values of 0.32, 0.005 and 0.43 µ m, respectively. In addition, the four tested compounds significantly inhibited nitric oxide release by lipopolysaccharide‐activated RAW 264.7 macrophages. The results show that the most effective compound was cis‐sabinene hydrate methyl ether (2). In addition, the cis‐configurated compound (2) exerted stronger activities in comparison with the trans‐configurated compound (1), suggesting geometric stereoselectivity for the biological activities. Copyright © 2011 John Wiley & Sons, Ltd.
Identification of key aroma compounds from bitter orange (Citrus aurantium L.) products: essential oil and macerate–distillate extract
Authors: Deterre Sophie , Rega Barbara , Delarue Julien , Decloux Martine , Lebrun Marc , Giampaoli Pierre
Published: September 2011

The volatile compounds of bitter orange (Citrus aurantium L.) products, essential oil (EO) and the heart cut (HC) of the distillate were detected and quantified using gas chromatography (GC) coupled with a mass spectrometer and flame ionization detector. The flavour compounds were characterized using GC–olfactometry by nine trained panellists by the frequency of detection method. In total, 53 molecules were detected in the EO and 40 in the HC. The EO was characterized by 19 major odour compounds (frequency of detection from 6/9 to 9/9) with different aromatic notes among which α‐pinene (floral), octanal (green), limonene (citrus), linalool (floral), α‐terpineol (indeterminate: ‘ND’, green), linalyl acetate (floral), (E,E) or (E,Z)‐2,4‐decadienal (frying), dodecanal (ND), caryophyllene (green) and an unknown compound (IT = 1678, plastic note). The HC presented a complex mixture of several molecules in low concentrations, which characterize the bitter orange flavour. The HC was characterized by seven high FD odour compounds, three of them (myrcene, α‐phellandrene, and limonene) with citrus and mint aromatic notes, and the other four ((Z)‐linalool oxide, α‐terpinolene, linalool and neral) with floral notes. The comparison of these two products brought to light that the overall process of maceration/distillation could induce the loss of 15 strong odours previously found in simple essential oil and characterized by plastic and metal notes. These results show that macerating–distilling bitter orange peels and EO makes it possible to select the most pleasant odour compounds while eliminating some off‐odours present in the EO. This is the first time that the characterization of odour‐active compounds has been carried out on bitter orange products. This valuable information could help for further investigation on process/product optimization. Copyright © 2011 John Wiley & Sons, Ltd.
Cognitive and behavioural predictors of survival in Alzheimer disease: results from a sample of treated patients in a tertiary‐referral memory clinic
Authors: Russ Tom C. , Batty G. David , Starr John M.
Published: September 2011

Objective

This study examined the influence of cognitive and non‐cognitive factors at the time of diagnosis on the survival of patients with treated probable Alzheimer Disease (AD).

Methods

Consecutive patients seen at a regional, tertiary‐referral clinic completed a battery of cognitive tests and assessments of activities of daily living and neuropsychiatric symptoms. These clinic data were linked with death certificate data for all individuals and survival from diagnosis was calculated. Cox regression models were constructed using the baseline covariates.

Results

The sample comprised 653 patients (459 women), mean age 77.1 years (SD 7.6, range 48–94 years), diagnosed with probable AD and treated with a cholinesterase inhibitor. In the survival analysis, age was a consistently significant predictor of survival with a gender‐adjusted hazard ratio of 1.35 (95% CI 1.23, 1.48) for one standard deviation increase in age. Men were at greater risk of death than women (age‐adjusted HR 1.44, 95% CI 1.19, 1.73). In a model adjusted for all study variables, Paired‐Associate Learning (Cambridge Automated Neuropsychological Test Assessment Battery) and the psychotic factor of the Neuropsychiatric Inventory were significant predictors of survival.

Conclusions

At diagnosis, in addition to the anticipated impact of age and gender, the presence of psychotic symptoms and poor performance on paired‐associate learning are also indicators of poor prognosis. Copyright © 2011 John Wiley & Sons, Ltd.
Linking soil thickness and plot‐scale hydrological processes on the sloping lands in the Three Gorges Area of China: a hydropedological approach
Authors: Fu Zhiyong , Li Zhaoxia , Cai Chongfa , Zhao Ying , Shi Zhihua , Xu Qinxue , Wang Xiaoyan
Published: September 2011

The emerging interdisciplinary field of hydropedology promotes synergistic integration of pedology and hydrology to enhance the holistic study of soil–water interactions across space and time. Our study illustrated this integration, exemplifying from plot‐scale hydrological processes investigations on the sloping lands with different soil thickness in the Three Gorges Area of China. Our aims were to deal with (i) the watershed scale soil thickness survey, soil profiles description and hydrological processes inferential analysis for the plots with typical soil thickness from the pedological perspective, and (ii) the identification of dominant hydrological processes of these plots based on hydrological monitoring under simulated rainfall (designed as 60 mm h−1) from the hydrological perspective. The main results can be summarised as follows: (i) soil thickness of the sloping lands exhibited a wide range of variability along hillslopes. Thin soils reflected weaker pedogenesis degrees and less intense human intervention as compared with thick soils. (ii) Deep percolation and subsurface flow were the dominant processes in thin soils, whereas in thick soils, surface flow, deep percolation and storage were the dominant processes. (iii) Regarding to the surface flow, the 23‐cm plot was mainly in the form of saturated overland flow, whereas the other plots were Horton overland flow. As to the subsurface flow, both 23‐ and 31‐cm plots mainly took the form of preferential flow, the 59‐ and 76‐cm plots mainly in the form of matrix flow regardless of soil horizon and the 45‐cm plot displayed mainly the matrix flow in the A horizon and mainly the preferential flow in the AC horizon. Our study suggested that, relative to its parent disciplines of both pedology and hydrology, hydropedology improved synergies between pedology and hydrology in the plot‐scale hydrological processes investigations. Copyright © 2011 John Wiley & Sons, Ltd.
Towards improved snow water equivalent retrieval algorithms for satellite passive microwave data over the mountainous basins of western USA
Authors: Mizukami Naoki , Perica Sanja
Published: September 2011

Space‐borne passive microwave snow water equivalent (SWE) retrieval algorithms are attractive for continuous SWE monitoring over large mountainous areas. The performance of three SWE retrieval algorithms, which were considered relevant for operational purposes, was examined for each month over the Colorado River Basin. In addition, statistical post‐processing was tested as a means of improving the SWE estimates from each algorithm. The evaluation started with the so‐called Chang equation, which was a pioneer algorithm and is still used in practice. Successive attempts were then made to improve the algorithm's performance through the calibration of the equation's coefficient and through the inclusion of brightness temperature data from various frequency channels. The Chang equation consistently underestimated SWE with average bias between 30 mm in November and more than 300 mm in April and root mean square error (RMSE) exceeding 500 mm at many locations in April. The statistical post‐processing effectively removed the bias and reduced the RMSE by half for all the months. When the Chang equation's coefficients were calibrated at each site, biases were reduced by approximately 85%, and RMSE was reduced by 40%–50%. Finally, the multiple channel equations produced unbiased SWE estimates with RMSEs 50%–60% of those from the Chang equation. However, the statistical post‐processing did not reduce RMSE for both calibrated algorithms. The last algorithm produced the most reliable estimates for at‐site analysis, but its skill deteriorated when analyses were performed over larger areal extents; therefore, it is only recommended for SWE monitoring over smaller areas. For larger areas, the calibrated Chang equation is desirable because it only requires interpolations of a calibrated coefficient, which was spatially coherent. Copyright © 2011 John Wiley & Sons, Ltd.
Boundary depletion rate and drawdown in leaky wedge‐shaped aquifers
Authors: Sedghi Mohammad Mahdi , Samani Nozar , Sleep Brent
Published: September 2011

This study presents analytical solutions of the three‐dimensional groundwater flow to a well in leaky confined and leaky water table wedge‐shaped aquifers. Leaky wedge‐shaped aquifers with and without storage in the aquitard are considered, and both transient and steady‐state drawdown solutions are derived. Unlike the previous solutions of the wedge‐shaped aquifers, the leakages from aquitard are considered in these solutions and unlike similar previous work for leaky aquifers, leakage from aquitards and from the water table are treated as the lower and upper boundary conditions. A special form of finite Fourier transforms is used to transform the z‐coordinate in deriving the solutions. The leakage induced by a partially penetrating pumping well in a wedge‐shaped aquifer depends on aquitard hydraulic parameters, the wedge‐shaped aquifer parameters, as well as the pumping well parameters. We calculate lateral boundary dimensionless flux at a representative line and investigate its sensitivity to the aquitard hydraulic parameters. We also investigate the effects of wedge angle, partial penetration, screen location and piezometer location on the steady‐state dimensionless drawdown for different leakage parameters. Results of our study are presented in the form of dimensionless flux‐dimensionless time and dimensionless drawdown‐leakage parameter type curves. The results are useful for evaluating the relative role of lateral wedge boundaries and leakage source on flow in wedge‐shaped aquifers. This is very useful for water management problems and for assessing groundwater pollution. The presented analytical solutions can also be used in parameter identification and in calculating stream depletion rate and volume. Copyright © 2011 John Wiley & Sons, Ltd.
Analyzing proteasomal subunit expression reveals Rpt4 as a prognostic marker in stage II colorectal cancer
Authors: McCawley Niamh , Conlon Susan , Hector Suzanne , Cummins Robert J. , Dicker Patrick , Johnston Patrick G. , Kay Elaine W. , McNamara Deborah A. , Prehn Jochen H.M. , Concannon Caoimhín G.
Published: September 2011

Colorectal cancer is a leading cause of cancer‐related deaths worldwide. Early diagnosis and treatment of colorectal cancer is the key to improving survival rates and as such a need exists to identify patients who may benefit from adjuvant chemotherapy. The dysregulation of the ubiquitin‐proteasome system (UPS) has been implicated in oncogenesis and cancer cell survival, and proteasome inhibitors are in clinical use for a number of malignancies including multiple myeloma. In our study, we examined the protein expression of several key components of the UPS in colorectal cancer using immunohistochemistry to determine expression levels of ubiquitinylated proteins and the proteasomal subunits, 20S core and Rpt4 in a cohort of 228 patients with colon cancer. Multivariate Cox analysis revealed that neither the intensity of either ubiquitinylated proteins or the 20S core was predictive in either Stage II or III colon cancer for disease free survival or overall survival. In contrast, in Stage II patients increased Rpt4 staining was significantly associated with disease free survival (Cox proportional hazard ratio 0.605; p = 0.0217). Our data suggest that Rpt4 is an independent prognostic variable for Stage II colorectal cancer and may aid in the decision of which patients undergo adjuvant chemotherapy.
Prevalence of human papillomavirus in women with invasive cervical carcinoma by HIV status in Kenya and South Africa
Authors: Vuyst Hugo De , Ndirangu Gathari , Moodley Manivasan , Tenet Vanessa , Estambale Benson , Meijer Chris J.L.M. , Snijders Peter J.F. , Clifford Gary , Franceschi Silvia
Published: September 2011

Data on the prevalence of human papillomavirus (HPV) types in cervical carcinoma in women with HIV are scarce but are essential to elucidate the influence of immunity on the carcinogenicity of different HPV types, and the potential impact of prophylactic HPV vaccines in populations with high HIV prevalence. We conducted a multicentre case–case study in Kenya and South Africa. During 2007–2009, frozen tissue biopsies from women with cervical carcinoma were tested for HPV DNA using GP5+/6+‐PCR assay. One hundred and six HIV‐positive (mean age 40.8 years) and 129 HIV‐negative women (mean age 45.7) with squamous cell carcinoma were included. Among HIV‐positive women, the mean CD4 count was 334 cells/μL and 48.1% were on combined antiretroviral therapy. HIV‐positive women had many more multiple HPV infections (21.6% of HPV‐positive carcinomas) compared with HIV‐negative women (3.3%) (p < 0.001) and the proportion of multiple infections was inversely related to CD4 level. An excess of HPV18 of borderline statistical significance was found in HIV‐positive compared with HIV‐negative cases (Prevalence ratio (PR) = 1.9, 95% confidence interval (CI): 1.0–3.7, adjusted for study centre, age and multiplicity of infection). HPV16 and/or 18 prevalence combined, however, was similar in HIV‐positive (66.7%) and HIV‐negative cases (69.1%) (PR = 1.0, 95% CI: 0.9–1.2). No significant difference was found for other HPV types. Our data suggest that current prophylactic HPV vaccines against HPV16 and 18 may prevent similar proportions of cervical SCC in HIV‐positive as in HIV‐negative women provided that vaccine‐related protection is sustained after HIV infection.
Antennal sensory structures in Scaphoideus titanus ball (Hemiptera: Cicadellidae)
Authors: Stacconi Marco Valerio Rossi , Romani Roberto
Published: September 2011

Scaphoideus titanus Ball (Hemiptera: Cicadomorpha) is a leafhopper vector of a phytoplasma disease, the Flavescence dorée (FD), belonging to the vine yellows group. A scanning and transmission electron microscope study has been carried out to investigate the antennal sensory structures. The first two segments, the scape and the pedicel, are short, covered by cuticular scales and devoid of sensilla, with exception of some scattered hairs on the pedicel. The flagellum consists of a unique, elongated segment in which numerous subunits can be recognized, being separated by a sort of cuticular crown. The proximal five subunits bear most of the sensilla. We discovered the presence of single‐ and double‐walled coeloconic sensilla, campaniform sensilla, basiconic sensilla, and trichoid sensilla. A scolopidium is located within the proximal region of the flagellum. Ultrastructural investigations suggest that the antennal sensilla could be involved in the perception of air‐borne vibrations, temperature, and humidity variations. The most relevant feature is the extreme reduction of the olfactory sensilla, both in terms of number of sensory structures and sensory neurons per sensillum. The strong reduction in antennal olfactory sensilla to which this specie has undergone is discussed as possible consequence of the specificity toward the host plant. Microsc. Res. Tech. 2011. © 2011 Wiley‐Liss, Inc.
“They're going to unplug grandma”: Advance directive discussions and documentation do not decrease survival in patients at baseline lower risk of death
Authors: Fischer Stacy M. , Min Sung‐Joon , Sauaia Angela , Kutner Jean S.
Published: September 2011

OBJECTIVE:

To determine the effect of having advance directive (AD) discussions or having an AD in the medical record on patient survival.

DESIGN:

Prospective observational cohort study.

SETTING:

Three Colorado area hospitals: a large academic tertiary referral center, a Veteran's Affairs medical center, and an urban safety net hospital.

PARTICIPANTS:

Four hundred fifty‐eight adults admitted to the general internal medicine service interviewed about AD discussions. A concurrent chart review documented the presence of an AD in the medical record. Participants were stratified into low, medium, and high risk of death within 1 year based on validated prognostic criteria.

MEASURES:

Kaplan‐Meier survival plots were estimated for those at low and medium risk of death.

RESULTS:

No significant differences in survival for participants at low and medium risk of death who reported having had an AD discussion and those who had not (Wilcoxon low risk, P = 0.97; medium risk, P = 0.28; and log‐rank low risk, P = 0.82; medium risk, P = 0.45), and for those who had an AD in the medical record vs those who did not (Wilcoxon low risk, P = 0.84; medium risk, P = 0.78; and log‐rank low risk, P = 0.86; medium risk, P = 0.69).

CONCLUSIONS:

There is no evidence that AD discussions or documentation result in increased mortality. In regards to the current national debate about the merits of advance care planning, this study suggests that honoring patients' wishes to engage in AD discussions and documentation does not lead to harm. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine
T2‐weighted cardiac MR assessment of the myocardial area‐at‐risk and salvage area in acute reperfused myocardial infarction: Comparison of state‐of‐the‐art dark blood and bright blood T2‐weighted sequences
Authors: Viallon Magalie , Mewton Nathan , Thuny Franck , Guehring Jens , O'Donnell Thomas , Stemmer Alto , Bi Xiaoming , Rapacchi Stanislas , Zuehlsdorff Sven , Revel Didier , Croisille Pierre
Published: September 2011

Purpose:

To compare different state‐of‐the‐art T2‐weighted (T2w) imaging sequences combined with late gadolinium enhancement (LGE) for myocardial salvage area (MSA) assessment by cardiac magnetic resonance (CMR). T2w imaging has been used to assess the myocardial area at risk (AAR) in acute myocardial infarction (AMI) patients, but its clinical application is challenging due to technical and physical limitations.

Materials and Methods:

Thirty patients with reperfused AMI underwent complete CMR imaging 2–5 days after hospital admission. Myocardial AAR and MSA were quantified on four different T2w sequences: (a) free‐breathing T2‐prepared single‐shot balanced steady‐state free precession (T2p_ssbSSFP); (b) breathhold T2‐weighted acquisition for cardiac unified T2 edema (ACUTE); (c) breathhold T2w dark‐blood inversion recovery turbo‐spin echo (IR‐TSE) (short‐term inversion recovery: STIR); and (d) free‐breathing high‐resolution T2 dark‐blood navigated BLADE. The diagnostic performance of each technique was also assessed.

Results:

Quantitative analysis showed significant differences in myocardial AAR extent as quantified by the four T2w sequences (P < 0.05). There were also significant differences in sensitivity, specificity and overall diagnostic performance.

Conclusion:

Detection and quantification of AAR, and thus of MSA, by T2wCMR in reperfused AMI patients varied significantly between different T2w sequences in the same clinical setting. J. Magn. Reson. Imaging 2012;328‐339. © 2011 Wiley Periodicals, Inc.
Cardiac motion in diffusion‐weighted MRI of the liver: artifact and a method of correction
Authors: Liau Joy , Lee Jimmy , Schroeder Michael E. , Sirlin Claude B. , Bydder Mark
Published: September 2011

Purpose:

To characterize cardiac motion artifacts in the liver and assess the use of a postprocessing method to mitigate these artifacts in repeat measurements.

Materials and Methods:

Three subjects underwent breathhold diffusion‐weighted (DW) scans consisting of 25 repetitions for three b‐values (0, 500, 1000 sec/mm2). Statistical maps computed from these repetitions were used to assess the distribution and behavior of cardiac motion artifacts in the liver. An objective postprocessing method to reduce the artifacts was compared with radiologist‐defined gold standards.

Results:

Signal dropout is pronounced in areas proximal to the heart, such as the left lobe, but also present in the right lobe and in distal liver segments. The dropout worsens with b‐value and leads to overestimation of the diffusivity. By reference to a radiologist‐defined gold standard, a postprocessing correction method is shown to reduce cardiac motion artifact.

Conclusion:

Cardiac motion leads to significant artifacts in liver DW imaging; we propose a postprocessing method that may be used to mitigate the artifact and is advantageous to standard signal averaging in acquisitions with multiple repetitions. J. Magn. Reson. Imaging 2012;318‐327. © 2011 Wiley Periodicals, Inc.
Effects of combining field strengths on auditory functional MRI group analysis: 1.5T and 3T
Authors: Han Kihwan , Talavage Thomas M.
Published: September 2011

Purpose:

To evaluate effects of combining functional magnetic resonance imaging (fMRI) data acquired from different field strengths on group analysis as a function of the number of subjects at each field strength.

Materials and Methods:

In all, 28 subjects (18 at 3T) participated in an auditory task of passively listening to a 0.75s segment of jazz music in an event‐related design. Results of single‐subject analysis were combined to create all possible subject combinations for a group size of eight subjects from each of the 3T and 1.5T pools, comprising subject mixtures of (3T/1.5T) 0/8, 2/6, 4/4, 6/2, and 8/0. Group analysis performance of each subject permutation was measured by receiver operating characteristic (ROC) curves and activation overlap maps.

Results:

While area under ROC curves, extent of activation in the gold standard region, and reliability of activation increased with the number of 3T subjects, marginal gain decreased. ROC performance overlap across mixtures was observed, indicating that some combinations of subjects markedly outperformed others. For detection of activation, 4/4 was arguably the minimum mixture level that was comparable to 3T‐only group results.

Conclusion:

Inclusion of 1.5T data does not necessarily reduce the validity of group analysis. Lower field strength data was found only to limit detection power, but did not affect specificity. Within the limits of realignment error, these results should also extend to group longitudinal analyses of subject mixtures from different field strengths. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Reproducibility of 3D 1H MR spectroscopic imaging of the prostate at 1.5T
Authors: Lagemaat Miriam W. , Zechmann Christian M. , Fütterer Jurgen J. , Weiland Elisabeth , Lu Jianping , Villeirs Geert M. , Holshouser Barbara A. , van Hecke Paul , Lemort Marc , Schlemmer Heinz‐Peter , Barentsz Jelle O. , Roell Stefan O. , Heerschap Arend , Scheenen Tom W.J.
Published: September 2011

Purpose:

To determine the reproducibility of 3D proton magnetic resonance spectroscopic imaging (1H‐MRSI) of the human prostate in a multicenter setting at 1.5T.

Materials and Methods:

Fourteen subjects were measured twice with 3D point‐resolved spectroscopy (PRESS) 1H‐MRSI using an endorectal coil. MRSI voxels were selected in the peripheral zone and combined central gland at the same location in the prostate in both measurements. Voxels with approved spectral quality were included to calculate Bland–Altman parameters for reproducibility from the choline plus creatine to citrate ratio (CC/C). The repeated spectroscopic data were also evaluated with a standardized clinical scoring system.

Results:

A total of 74 voxels were included for reproducibility analysis. The complete range of biologically interesting CC/C ratios was covered. The overall within‐voxel standard deviation (SD) of the CC/C ratio of the repeated measurements was 0.13. This value is equal to the between‐subject SD of noncancer prostate tissue. In >90% of the voxels the standardized clinical score did not differ relevantly between the measurements.

Conclusion:

Repeated measurements of in vivo 3D 1H‐MRSI of the complete prostate at 1.5T produce equal and quantitative results. The reproducibility of the technique is high enough to provide it as a reliable tool in assessing tumor presence in the prostate. J. Magn. Reson. Imaging 2012;35:166‐173. © 2011 Wiley Periodicals, Inc.
The relationship between Lamb weather types and long‐term changes in flood frequency, River Eden, UK
Authors: Pattison Ian , Lane Stuart N.
Published: September 2011

Research has found that both flood magnitude and frequency in the UK may have increased over the last five decades. However, evaluating whether or not this is a systematic trend is difficult because of the lack of longer records. Here we compile and consider an extreme flood record that extends back to 1770. Since 1770, there have been 137 recorded extreme floods. However, over this period, there is not a unidirectional trend of rising extreme flood risk over time. Instead, there are clear flood‐rich and flood‐poor periods. Three main flood‐rich periods were identified: 1873–1904, 1923–1933, and 1994 onwards. To provide a first analysis of what is driving these periods, and given the paucity of more sophisticated datasets that extend back to the 18th century, objective Lamb weather types were used. Of the 27 objective Lamb weather types, only 11 could be associated with the extreme floods during the gauged period, and only 5 of these accounted for > 80% of recorded extreme floods The importance of these five weather types over a longer timescale for flood risk in Carlisle was assessed, through calculating the proportion of each hydrological year classified as being associated with these flood‐generating weather types. Two periods clearly had more than the average proportions of the year classified as one of the flood causing weather types; 1900–1940 and 1983–2007; and these two periods both contained flood‐rich hydrological records. Thus, the analysis suggests that systematic organisation of the North Atlantic climate system may be manifest as periods of elevated and reduced flood risk, an observation that has major implications for analyses that assume that climatic drivers of flood risk can be either statistically stationary or are following a simple trend. Copyright © 2011 Royal Meteorological Society
Contribution of late spring Eurasian snow cover extent to Canadian winter temperatures
Authors: Shabbar Amir , Zhao Hongxu
Published: September 2011

This study examines intercontinental linkages between late spring and early summer Eurasian snow cover extent (SCEss) anomalies and the following winter temperature anomalies over Canada for the 1972–2006 period. The structure of the second interannual mode of Canadian winter temperatures variability captures the SCEss related modulation. The North Atlantic winter atmospheric circulation changes associated with the SCEss, resembling the negative phase of the North Atlantic Oscillation (NAO), suggest a possible pathway for the SCEss influences on the Canadian winter temperatures.

Regression and composite analyses show that the SCEss relate robustly to the Canadian winter climate. Larger‐than‐normal SCEss is associated with below normal winter temperatures in south‐central Canada and above normal temperatures over northeastern Canada. Predictive skill of Canadian winter temperatures based on a cross‐validated regression model shows that the SCEss offers the predictive potential over regions of Canada where El Niño‐Southern Oscillation (ENSO) related skill is weak or nonexistent. Analysis of winter extreme minimum temperatures, by a non‐stationary generalized extreme value model, with the SCEss as a covariate, exhibits statistically significant changes over Canada resembling a pattern similar to that of winter mean temperatures. Wavelet analysis shows significant coherence between the SCEss and the second mode of winter temperature variability in the 8–12‐year band. Copyright © 2011 Crown in the right of Canada. Published by John Wiley & Sons, Ltd
Kyphoplasty in patients with multiple myeloma a retrospective comparative pilot study
Authors: Kasperk Christian , Haas Andreas , Hillengass Jens , Weiss Christel , Neben Kai , Goldschmidt Hartmut , Sommer Ulrike , Nawroth Peter , Meeder Peter‐Jürgen , Wiedenhöfer Bernd , Schmidmaier Gerhard , Tanner Michael , Neuhof Dirk , Nöldge Gerd , Grafe Ingo A.
Published: September 2011

Background

This retrospective study of 73 myeloma patients with painful vertebral lesions compares clinical and radiomorphological outcomes up to 2 years after additional kyphoplasty, radiation therapy or systemic treatment only.

Methods

We assessed pain, disability and radiomorphological parameters by visual analogue scale (VAS 0‐100), Oswestry Disability Index and by re‐evaluating available follow‐up X‐rays, respectively, in patients that were treated according to a clinical pathway.

Results

After 2 years the VAS score was reduced in all groups by 66 ± 8.2 (kyphoplasty), 35 ± 10.5 (radiation therapy) and 38 ± 20.5 (systemic therapy only). Only after kyphoplasty we observed a significantly reduced Oswestry Disability Index after 1 year (P < 0.001). Vertebral height remained stable after kyphoplasty (P = 0.283), in contrast to a progressive height loss in the other groups (P = 0.013 and P = 0.015 for radiation and systemic therapy only, respectively). Two years after kyphoplasty and radiotherapy the overall vertebral fracture incidence was significantly decreased as compared to the group after systemic therapy only (9.7% of all thoracic and lumbar vertebrae had new vertebral fractures after systemic therapy only, 2% after kyphoplasty (P < 0.001), 4.8% after radiation (P = 0.032)).

Conclusion

Additional kyphoplasty was more effective than additional radiation or systemic therapy in terms of pain relief, reduction of pain associated disability and reduction of fracture incidence of the entire lumbar and thoracic spine. J. Surg. Oncol. 2012; 105:679–686. © 2011 Wiley Periodicals, Inc.
Influence of Interfacial Activity and Micelle Formation on Rheological Behavior and Microstructure of Reactively Compatibilized PP/PET Blends
Authors: Entezam Mahdi , Khonakdar Hossein Ali , Yousefi Ali Akbar , Jafari Seyed Hassan , Wagenknecht Udo , Heinrich Gert , Kretzschmar Bernd
Published: September 2011

Dynamic and start‐up shear flow experiments along with SEM analysis are described for a PP/PET blend compatibilized by two reactive compatibilizers with different interfacial activity and rheological characteristics. The linear viscoelastic behavior of the blends is discussed using Palierne and fractional Zener models (FZMs). The nonzero value of Ge, the elastic modulus of spring element of FZM, is explained by the network‐like structure of the blends attributed to the interconnectivity between dispersed‐phase domains. Ge increases with increasing interfacial activity. Micelle formation due to extra amounts of compatibilizer in a system with higher interfacial activity leads to an increase of the elastic modulus, but to Ge = 0 in system with lower interfacial activity.

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The contribution of β‐carotene to vitamin A supply of humans
Authors: Weber Daniela , Grune Tilman
Published: September 2011

Populations that administer highly restrictive diets using a strong dietary regime, excluding certain types of food, might be at risk of vitamin A insufficiency, even in developed countries. Thus, provitamin A carotenoids from plants represent an additional major dietary source of vitamin A for most of the world's population. Our aim was to estimate the contribution of β‐carotene to vitamin A supply in industrialized countries using available data from the literature. A total of 11 studies from 8 countries were used, representing data of 121 256 participants. Intakes of total vitamin A, provitamin A carotenoids, including β‐carotene were retrieved and used to calculate the retinol activity equivalents (RAE) utilizing current conversion factors. Mean total daily dietary intake of RAE was 1083±175. The mean β‐carotene intake was 3.9 mg/day. Preformed vitamin A accounts for nearly 65% of total vitamin A intake, carotenoids make up 35%. No statistical differences between men and women in total intake of retinol were observed. We conclude that a safe vitamin A intake in general cannot be reached by consuming only one component (vitamin A or β‐carotene) alone, even in Western countries where animal products are commonly available.
Genetic variations involved in interindividual variability in carotenoid status
Authors: Borel Patrick
Published: September 2011

As shown in most clinical studies dedicated to carotenoids, there is a huge interindividual variability in absorption, and blood and tissue responses, of dietary carotenoids. The recent discovery that several proteins are involved in carotenoid metabolism in humans has prompted a possible explanation for this phenomenon: genetic variants in genes encoding for these proteins may affect their expression or activity, and in turn carotenoid metabolism and carotenoid status. The proteins clearly identified so far are (i) the carotene oxygenases β,β‐carotene‐15,15′‐monooxygenase (BCMO1) and β,β‐carotene‐9′,10′‐oxygenase (BCDO2), which are involved in carotenoid cleavage, (ii) scavenger receptor class B type I (SR‐BI), cluster determinant 36 (CD36), and Niemann Pick C1‐like 1 (NPC1L1), which are involved in carotenoid uptake by cells, and (iii) glutathione S‐transferase Pi 1 (GSTP1) and human retinal lutein‐binding protein (HR‐LBP), which are involved in the transport of xanthophylls in the retina. Other proteins, such as ATP‐binding cassette subfamily G member 5 (ABCG5) and the fatty acid‐binding proteins (FABPs) are also apparently involved although firmer evidence is still required. A genome‐wide association study, as well as several candidate gene association studies, has shown that groups of subjects bearing different alleles in single nucleotide polymorphisms located in or near several of the above‐mentioned genes display different blood and/or tissue concentrations of carotenoids. Further studies are needed to identify all the proteins involved in carotenoid metabolism and assess whether other types of genetic variation, e.g. copy number variants and epigenetic modifications, can modulate carotenoid status. One potential application of such research could be personalized dietary guidelines for carotenoids according to individual genetic characteristics.
Mechanisms underlying somatostatin receptor 2 down‐regulation of vascular endothelial growth factor expression in response to hypoxia in mouse retinal explants
Authors: Mei Sara , Cammalleri Maurizio , Azara Danilo , Casini Giovanni , Bagnoli Paola , Dal Monte Massimo
Published: September 2011

Hypoxia is a trigger of VEGF expression, the primary cause of retinal pathologies characterized by neovascularization. During hypoxia, transcription factors such as STAT3 and HIF‐1 promote the increase in VEGF expression. Octreotide, a somatostatin receptor 2 (sst2)‐preferring agonist, reduces retinal VEGF expression and neovascularization. To investigate the intracellular pathways linking sst2 activation to the inhibition of hypoxia‐induced VEGF up‐regulation, we used pharmacological approaches and siRNA in mouse retinal explants cultured in normoxia or hypoxia. In hypoxic explants in which STAT3 or HIF‐1 was inhibited, we observed the existence of reciprocal interactions between STAT3 and HIF‐1, which synergistically induced VEGF expression. Octreotide prevented hypoxia‐induced activation of STAT3 and HIF‐1, and the downstream increase in VEGF expression, as evaluated in hypoxic explants treated with pharmacological inhibitors of STAT3 or HIF‐1 and in normoxic explants in which pharmacological activators of STAT3 or HIF‐1 were used to mimic a hypoxia‐like response. The effect of octreotide on STAT3 activation is in part indirect, through the blockade of VEGFR‐2 phosphorylation. The effect of octreotide on STAT3, HIF‐1, VEGFR‐2, and VEGF required Src homology region 2 domain‐containing phosphatase 1 (SHP‐1). In hypoxic extracts, octreotide induced SHP‐1 phosphorylation and activation, and inhibiting SHP‐1 abolished the octreotide effect on STAT3, HIF‐1, VEGFR‐2, and VEGF. The central role of SHP‐1 in the modulation of STAT3 and HIF‐1 was confirmed in normoxic explants in which pharmacologically activated SHP‐1 prevented the effect of STAT3 or HIF‐1 activation. Immunohistochemical studies showed that under hypoxia sst2 and VEGF are expressed by retinal vessels, thus indicating a possible direct effect of octreotide on VEGF‐containing endothelial cells. These data clarify the mechanism by which octreotide prevents hypoxia‐induced VEGF up‐regulation and support the effectiveness of octreotide in treatment of oxygen‐induced retinopathies. These results may have implications in designing therapies targeting STAT3 and/or HIF‐1 aimed at preventing retinal neovascularization. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Severity of doxorubicin‐induced small intestinal mucositis is regulated by the TLR‐2 and TLR‐9 pathways
Authors: Kaczmarek Agnieszka , Brinkman Brigitta M , Heyndrickx Liesbeth , Vandenabeele Peter , Krysko Dmitri V
Published: September 2011

Intestinal mucositis is a serious complication of cancer chemotherapy and radiotherapy; it frequently compromises treatment and dramatically reduces the quality of life of patients. Different approaches to limit the damage to the intestine during anti‐cancer therapy have been largely ineffective due to insufficient knowledge of the mechanism of mucositis development. This study aimed to define the role of TLR‐2 and TLR‐9 in the modulation of small intestinal damage in a model of doxorubicin‐induced mucositis. Doxorubicin‐induced intestinal damage was verified by a histological score (HS), analysis of leukocyte influx into the lamina propria, and determination of the number of apoptotic cells. Additionally, the activation status of glycogen synthase kinase 3β (GSK‐3β) was assessed. Wild‐type (WT) mice injected with doxorubicin demonstrated severe intestinal damage (HS 8.0 ± 0.81), reduction of villus length to 43.9% ± 13.7% of original length, and increased influx of leukocytes as compared to vehicle‐injected mice (HS 1.33 ± 1.15). The protective effect of TLR‐2 or TLR‐9 deficiency was associated with a significant decrease of the HS as compared to WT mice. In the ileum, a minor reduction of villus length and a decreased number of infiltrating leukocytes and TUNEL‐positive cells was observed. We demonstrate that the TLR‐9 antagonist ODN2088 reduces doxorubicin‐induced intestinal damage. Furthermore, we show that GSK‐3β activity is inhibited in the absence of TLR‐2. The protective capacity of GSK‐3β suppression was observed in WT mice by inhibiting it with the specific inhibitor SB216763. Overall, our findings demonstrate that the TLR‐2/GSK‐3β and TLR‐9 signalling pathways play a central role in the development of intestinal mucositis and we suggest a new therapeutic strategy for limiting doxorubicin‐induced intestinal inflammation. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Application of free‐volume theory to self diffusion of solvents in polymers below the glass transition temperature: A review
Authors: Ramesh N. , Davis P. K. , Zielinski J. M. , Danner R. P. , Duda J. L.
Published: September 2011

Theories based on free‐volume concepts have been developed to characterize the self and mutual‐diffusion coefficients of low molecular weight penetrants in rubbery and glassy polymer‐solvent systems. These theories are applicable over wide ranges of temperature and concentration. The capability of free‐volume theory to describe solvent diffusion in glassy polymers is reviewed in this article. Two alternative free‐volume based approaches used to evaluate solvent self‐diffusion coefficients in glassy polymer‐solvent systems are compared in terms of their differences and applicability. The models can correlate/predict temperature and concentration dependencies of the solvent diffusion coefficient. With the appropriate accompanying thermodynamic factors they can be used to model concentration profiles in mutual diffusion processes that are Fickian such as drying of coatings. The free‐volume methodology has been found to be consistent with molecular dynamics simulations. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Psychometric properties of the Functional Assessment of Chronic Illness Therapy—Spiritual Well‐being (FACIT‐Sp) in an Arabic‐speaking, predominantly Muslim population
Authors: Lazenby Mark , Khatib Jamal , Al‐Khair Feda' , Neamat Majdoleen
Published: September 2011

Objective

This study determined the psychometric properties of the Arabic Functional Assessment of Chronic Illness Therapy—Spiritual Well‐being (FACIT‐Sp) Version 4 and explored associations between its three factors (Peace, Meaning, and Faith) and health‐related quality of life (HrQoL) among Arab patients with cancer.

Methods

A total of 205 Arabic‐speaking, study‐eligible cancer patients who were in treatment at the King Hussein Cancer Center, Amman, Jordan, completed the FACIT‐Sp scale.

Results

Cronbach's alpha reliability coefficients suggest that the Arabic FACIT‐Sp is reliable and that moderate to strong correlations among subscales suggest validity. Correlation analyses showed that the 12‐item Spiritual Well‐being scale was associated with Social (r = 0.45, p = 0.01) and Functional Well‐being (r = 0.48, p = 0.01). Hierarchical multiple regressions revealed that the Peace factor added 7.5% and the Meaning factor 3.8% to the prediction of HrQoL (p < 0.001). Faith did not significantly contribute to the unique prediction of HrQoL. Correlation analyses revealed that Peace was most prominently associated with the HrQoL subscale of Functional Well‐being (r = 0.53, p = 0.01).

Conclusions

This first study of Arabic‐speaking, predominantly Muslim Jordanian cancer patients using the FACIT‐Sp indicates that it is a psychometrically sound instrument for detailed assessment of the spiritual well‐being of Arabic‐speaking cancer patients. The three‐factor model appears to allow for discrimination among factors that are most highly associated with different aspects of HrQoL. Copyright © 2011 John Wiley & Sons, Ltd.