bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative evaluation of breast cancer response to neoadjuvant chemotherapy by diffusion tensor imaging: Initial results
Authors: Furman‐Haran Edna , Nissan Noam , Ricart‐Selma Verónica , Martinez‐Rubio Carmen , Degani Hadassa , Camps‐Herrero Julia
Published: September 2017

Background

Diffusion tensor imaging (DTI) yields several parameters that have not been tested in response evaluation to neoadjuvant chemotherapy (NAC).

Purpose

To evaluate and compare in reference to histopathology findings the ability of DTI and dynamic contrast‐enhanced (DCE) MRI to monitor response to NAC.

Study Type

Retrospective.

Population

Twenty patients treated with neoadjuvant chemotherapy.

Field Strength/Sequence

1.5T MRI axial, bilateral T2‐weighted, DTI, and DCE‐MRI.

Assessment

A standardized blinded image analysis at pixel resolution generated color‐coded maps of DTI and DCE parameters

Statistical Tests

Pearson's correlation analysis and Bland–Altman plots of the DTI and DCE size changes and of the pathological final residual tumor diameter and DCE or DTI final diameter, from pre‐ to post‐NAC. Spearman coefficient of rank correlation between the DTI and DCE size changes from pre‐ to post‐NAC and Miller and Payne (M&P) pathological response grading. Receiver operating characteristic curve analyses to differentiate between responders to nonresponders on the basis of the DTI and DCE percent size changes and the changes in DTI parameters.

Results

DTI and DCE changes in the cancers' diameter and volume from pre‐ to post‐NAC exhibited high and significant Pearson correlation (r = 0.82 P = 1.2 × 10−5). The DTI volume changes exhibited a significant Spearman coefficient rank correlation (0.68, P = 0.001) with the pathological M&P grading and differentiated between responders and nonresponders with area‐under‐the‐curve (AUC) of 0.83 ± 0.10. A similar AUC for differentiating responders from nonresponders was exhibited by the changes in the highest diffusion coefficient (0.84 ± 0.11) and the mean diffusivity (0.83 ± 0.11). The DTI residual‐tumor‐diameter showed a high and significant Pearson correlation (r = 0.87 P = 1.2 × 10−6) to pathology tumor diameter.

Data Conclusion

DTI monitors changes in cancer size and diffusion tensor parameters in response to NAC with an accuracy equivalent to that of DCE, enabling differentiation of responders from nonresponders and assessment of residual tumor size in high congruence with pathology.

Level of Evidence: 1

Technical Efficacy: Stage 4

J. Magn. Reson. Imaging 2018;47:1080–1090.
Clinically insignificant prostate cancer suitable for active surveillance according to Prostate Cancer Research International: Active surveillance criteria: Utility of PI‐RADS v2
Authors: Yim Jae Hyun , Kim Chan Kyo , Kim Jae‐Hun
Published: September 2017

Background

Active surveillance (AS) is an important treatment strategy for prostate cancer (PCa). Prostate Imaging‐Reporting and Data System (PI‐RADS) v2 has been addressed, but few studies have reported the value of PI‐RADS v2 for assessing risk stratification in patients with PCa, especially on selecting potential candidates for AS.

Purpose

To investigate the utility of PI‐RADS v2 and apparent diffusion coefficient (ADC) in evaluating patients with insignificant PCa, who are suitable for AS.

Study Type

Retrospective.

Subjects

In all, 238 patients with PCa who met the Prostate Cancer Research International: Active Surveillance criteria underwent radical prostatectomy.

Field Strength/Sequence

3.0T, including T2‐weighted, diffusion‐weighted, and dynamic contrast‐enhanced imaging.

Assessment

Insignificant cancer was defined histopathologically as an organ‐confined disease with a tumor volume <0.5 cm3 without Gleason score 4–5. Patients were divided into two groups based on the PI‐RADS v2 and tumor ADC: A, PI‐RADS score ≤3 and ADC ≥1.095 × 10−3mm2/s; and B, PI‐RADS score 4–5 or ADC <1.095 × 10−3mm2/s. Preoperative clinical and imaging variables were evaluated regarding the associations with insignificant cancer.

Results

Of the 238 patients, 101 (42.8%) were diagnosed with insignificant cancer on pathological findings. The number of positive cores, prostate‐specific antigen density (PSAD), PI‐RADS v2 and tumor ADC were significantly associated with insignificant cancer on univariate analysis (P < 0.05). However, multivariate analysis indicated tumor ADC (odds ratio [OR] = 4.57, P < 0.001) and PI‐RADS v2 (OR = 3.60, P < 0.001) were independent predictors of insignificant cancer. Area under the receiver operating characteristics curve (AUC) reached 0.803 when PI‐RADS v2 (AUC = 0.747) was combined with tumor ADC (AUC = 0.786).

Data Conclusion

The PI‐RADS v2 together with tumor ADC may be a useful marker for predicting patients with insignificant PCa when considering AS.

Level of Evidence: 4

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2018;47:1072–1079.
Antecedents of organizational and community embeddedness: The roles of support, psychological safety, and need to belong
Authors: Singh Barjinder , Shaffer Margaret A. , Selvarajan T.T.
Published: September 2017

Defining embeddedness as a psychological construct that influences individuals to stay, we draw on conservation of resources theory to develop and test a model of the influence of contextual social support resources on both organizational and community forms of embeddedness. In addition to the direct relationship between support and embeddedness, we also assess the mediating influence of organizational and community psychological safety and the moderating impact of need to belong. Using a multisource sample of employees and coworkers (N = 165), we found support for most of the hypotheses. Social support resources emanating from the organization and the community were positively associated with embeddedness in each domain, and psychological safety mediated these relationships. We also found that need to belong was an important boundary condition in the determination of organizational embeddedness. We discuss the theoretical contributions and practical implications of our findings.
Rhizospheric fungi and their link with the nitrogen‐fixing Frankia harbored in host plant Hippophae rhamnoides L
Authors: Zhou Xue , Tian Lei , Zhang Jianfeng , Ma Lina , Li Xiujun , Tian Chunjie
Published: September 2017

Sea buckthorn (Hippophae rhamnoides L.) is a pioneer plant used for land reclamation and an appropriate material for studying the interactions of symbiotic microorganisms because of its nitrogen‐fixing root nodules and mycorrhiza. We used high‐throughput sequencing to reveal the diversities and community structures of rhizospheric fungi and their link with nitrogen‐fixing Frankia harbored in sea buckthorn collected along an altitude gradient from the Qinghai Tibet Plateau to interior areas. We found that the fungal diversities and compositions varied between different sites. Ascomycota, Basidiomycota, and Zygomycota were the dominant phyla. The distribution of sea buckthorn rhizospheric fungi was driven by both environmental factors and the geographic distance. Among all examined soil characteristics, altitude, AP, and pH were found to have significant (p < 0.05) effect on the rhizospheric fungal community. The rhizospheric fungal communities became more distinct as the distance increased. Moreover, co‐inertia analysis identified significant co‐structures between Frankia and AMF communities in the rhizosphere of sea buckthorn. We conclude that at the large scale, there are certain linkages between nitrogen‐fixing bacteria and the AMF expressed in the distributional pattern.
How well does the European Centre for Medium‐Range Weather Forecasting Interim Reanalysis represent the surface air temperature in Cuban weather stations?
Authors: Rodríguez‐Vega Albeht , Antuña‐Marrero Juan C. , Mesquita Michel D. S. , Robock Alan , Toniazzo Thomas , Otterå Odd H.
Published: September 2017

In this research, we compare 2‐m air temperature from the ERA‐Interim reanalysis of the European Centre for Medium‐Range Weather Forecasting with 2‐m air temperature weather station observations in Cuba, with the goal of evaluating the behaviour and uncertainties of the ERA‐Interim data set with respect to station‐based observations. Three interpolation methods are used to determine 2‐m temperatures from the ERA‐Interim data set at the station locations. The differences were analysed utilizing root mean square error (RMSE), mean absolute error (MAE) and bias. The comparison was conducted for daily, monthly and annual time scales, and for the rainy (May–October) and less rainy (November–April) seasons. The best interpolation method is the mean of four grid points method. We find a warm bias in the ERA‐Interim reanalysis for most Cuban stations. The smallest differences are at 1800 UTC and the largest differences are at 1200 UTC. All differences are greater than 0.3 K, although many of the stations show differences in the range of 1.5–2.0 K. In some stations the differences are greater than 5.0 K. At the daily scale more than 50% of the stations show significant differences at the 95% confidence level. The differences are caused by the altitude difference between the stations and the nearest grid point of ERA‐Interim, the land‐sea mask of ERA‐Interim and the station location respect to this mask, and by local processes, such as a local breeze. At the monthly scale there are fewer stations with significant differences than for the other time scales. The ERA‐Interim reanalysis better represents the surface 2‐m temperature for coastal stations than for inland stations. Years with moderate and strong El Niño or La Niña show significant differences between ERA‐Interim and observations. The amplitude between the maximum bias and the minimum bias is greater in those years.
An event synchronization method to link heavy rainfall events and large‐scale atmospheric circulation features
Authors: Conticello Federico , Cioffi Francesco , Merz Bruno , Lall Upmanu
Published: September 2017

Heavy rainfall, floods and other hydroclimatic extremes may be related to specific states of organization of the atmospheric circulation. The identification of these states and their linkage to local extremes could facilitate a physically meaningful quantification of local extremes in future climates and could allow forecasting extremes conditioned on the large‐scale atmospheric state. A novel methodology is presented that combines non‐linear, non‐parametric methods to link heavy precipitation events (HPEs) to atmospheric circulation states. Using daily rainfall data for the period 1951–2015 from 37 gauges in the Lazio region in Italy, HPEs are defined. For the same period, two atmospheric variables, namely, the 850 hPa geopotential height field and the integrated vapour transport (IVT), are derived from reanalysis data. The geopotential configurations driving heavy precipitation in the region are identified by combing self‐organized maps and event synchronization. First, a finite number of representative geopotential configurations is identified. Rainfall gauges are pooled into clusters, which show synchronized occurrence of heavy precipitation. Furthermore, geopotential configurations are identified, which tend to drive HPEs. For these geopotential states, the probability of HPE occurrence as a function of IVT is calculated through a local logistic regression model. Finally, it is explored whether the identified patterns are related to the occurrence of atmospheric rivers, which govern the atmospheric humidity transport from the tropics and subtropics to Europe. The relation found demonstrates the reliability of the proposed methodology.
Climatic and non‐climatic controls shaping early postglacial conifer history in the northern Greater Yellowstone Ecosystem, USA
Authors: Krause Teresa R. , Whitlock Cathy
Published: September 2017

Mountain ecosystems are characterized by their complex vegetation responses to past climate variability because of the interplay between large‐scale climate changes and local‐scale biotic and abiotic conditions. This study reconstructs the early postglacial expansion of conifer populations in the northern Greater Yellowstone Ecosystem (GYE). The objective is to examine how climate change and non‐climatic factors, including species characteristics, edaphic conditions and disturbance, governed postglacial vegetation changes. Spruce populations expanded first at 13 300 cal a BP, concurrent with soil development and warming summers. Subalpine fir populations expanded after 12 300 cal a BPand probably lagged spruce expansion due to differences in climatic tolerances and/or its poorer seed dispersing capacity. Pine species expanded nearly synchronously after 11 300 cal a BPin response to elevated summer temperatures and increased fire activity. Douglas‐fir populations expanded last after 10 200 cal a BPduring the early Holocene summer insolation maximum and cooler winters. The sequence and timing of conifer expansions in the northern GYE are consistent with the regional conifer history, indicating strong vegetation responses to millennial‐scale climate change associated with the seasonal cycle of insolation across spatial scales. Nonetheless, non‐climatic factors, including landscape stabilization and subsequent soil development, seed dispersing characteristics and fire, still shaped local‐scale patterns of conifer expansion.
Monascus‐fermented red mold dioscorea protects mice against alcohol‐induced liver injury, whereas its metabolites ankaflavin and monascin regulate ethanol‐induced peroxisome proliferator‐activated receptor‐γ and sterol regulatory element‐binding transcription factor‐1 expression in HepG2 cells
Authors: Cheng Chih‐Fu , Pan Tzu‐Ming
Published: September 2017

BACKGROUND

Alcoholic hepatitis is a necroinflammatory process that is associated with fibrosis and leads to cirrhosis in 40% of cases. The hepatoprotective effects of red mold dioscorea (RMD) from Monascus purpureus NTU 568 were evaluated in vivo using a mouse model of chronic alcohol‐induced liver disease (ALD).

RESULTS

ALD mice were orally administered vehicle (ALD group) or vehicle plus 307.5, 615.0 or 1537.5 mg kg–1 (1 ×, 2 × and 5 ×) RMD for 5 weeks. RMD lowered serum leptin, hepatic total cholesterol, free fatty acid and hepatic triglyceride levels and increased serum adiponectin, hepatic alcohol dehydrogenase and antioxidant enzyme levels. Furthermore, ankaflavin (AK) and monascin (MS), metabolites of RMD fermented with M. purpureus 568, induced peroxisome proliferator‐activated receptor‐γ expression and the concomitant suppression of ethanol‐induced elevation of sterol regulatory element‐binding transcription factor‐1 and TG in HepG2 cells.

CONCLUSION

These results indicate the hepatoprotective effect of Monascus‐fermented RMD. Moreover, AK and MS were identified as the active constituents of RMD for the first time and were shown to protect against ethanol‐induced liver damage. © 2017 Society of Chemical Industry
Inhibition of influenza virus replication by adlay tea
Authors: Nagai Emiko , Iwai Miwa , Koketsu Ritsuko , Sogabe Riho , Morimoto Ryosuke , Suzuki Yuri , Ohta Yoichiro , Okuno Yoshinobu , Ohshima Atsushi , Enomoto Toshiki , Isegawa Yuji
Published: September 2017

BACKGROUND

The present study was conducted aiming to examine the antiviral activity of adlay tea and its components against influenza viruses. We further aimed to clarify the mechanism by which these components regulate virus replication.

RESULTS

Adlay tea at a concentration suitable for drinking inhibited the multiplication of influenza viruses. Moreover, our results suggest that individual components of the tea had antiviral activities against the influenza A/PR/8/34 virus. Adlay tea inhibited multiplication of the H1N1, H3N2 and B types of influenza virus, including oseltamivir‐resistant viruses. In addition, adlay tea inhibited influenza infection during the periods of virus adsorption to the cell and virus replication. Adlay tea did not suppress hemagglutination inhibition or cell fusion, although it slightly inhibited virus binding to Malin Darby canine kidney cells. Furthermore, our findings suggest that the antiviral compounds included in adlay tea were ingredients other than polyphenols and that there were several types of effective compounds in adlay tea inhibiting several steps of viral replication.

CONCLUSION

The results of the present study demonstrate that adlay tea had antiviral effects against influenza viruses. Our findings with respect to adlay tea suggest that the polyphenols might have a small influence on its antiviral activity and that other ingredients might have more influence. © 2017 Society of Chemical Industry
Using repeated 137Cs and 210Pbex measurements to establish sediment budgets for different time windows and explore the effect of connectivity on soil erosion rates in a small experimental catchment in Southern Italy
Authors: Porto Paolo , Walling Desmond E. , Callegari Giovanni
Published: September 2017

Over the last 50 years, different approaches have been employed in order to predict environmental risk due to soil erosion and to propose effective strategies to control erosion and sedimentation. The use of fallout radionuclides, mainly caesium‐137 (137Cs) and excess lead‐210 (210Pbex), has proved to be a very effective complement to existing traditional methods, especially if a resampling strategy is employed. The resampling approach involves repeating soil sampling and radionuclide measurements within the same site, after a known amount of time (generally 10 to 15 years). This strategy, in the light of the possibility to obtain independent estimates of soil erosion for different periods, makes it possible to establish sediment budgets for different time windows. The use of sediment budgets represents an important tool for providing information on catchment behaviour regarding the relationship between the sediment output at the catchment outlet and rates of sediment redistribution within the catchment. For this reason, this approach can provide important indications of possible changes of sediment connectivity at the catchment scale. The study reported here focuses on the W1 catchment (1.47 ha), located in Calabria, Southern Italy, for which long‐term measurements of sediment yield are also available. The W1 catchment supports a rangeland vegetation cover, and no change in land use occurred during the last 100 years. The catchment was sampled for 137Cs and 210Pbex analyses in 2001 and resampled in 2014 to provide estimates of soil erosion and deposition for different time windows. The uncertainty associated with these estimates is also discussed, and some guidelines for the application of 210Pbex as a soil erosion tracer are provided. The results provided by the measurements of sediment yield at the catchment outlet provide evidence of a general increase of soil erosion rates during the last 15–20 years. The estimates of sediment redistribution provided by the measurements of 210Pbex demonstrated that these results reflect an increase in the sediment delivery ratio and also emphasized how the presence of some small depositional areas associated with the occurrence of high‐magnitude events influences the change in sediment connectivity at the catchment scale.
Ice duration drives winter nitrate accumulation in north temperate lakes
Authors: Powers S. M. , Labou S. G. , Baulch H. M. , Hunt R. J. , Lottig N. R. , Hampton S. E. , Stanley E. H.
Published: September 2017

The duration of winter ice cover on lakes varies substantially with climate variability, and has decreased over the last several decades in many temperate lakes. However, little is known of how changes in seasonal ice cover may affect biogeochemical processes under ice. We examined winter nitrogen (N) dynamics under ice using a 30+ yr dataset from five oligotrophic/mesotrophic north temperate lakes to determine how changes in inorganic N species varied with ice duration. Nitrate accumulated during winter and was strongly related to the number of days since ice‐on. Exogenous inputs accounted for less than 3% of nitrate accumulation in four of the five lakes, suggesting a paramount role of nitrification in regulating N transformation and the timing of chemical conditions under ice. Winter nitrate accumulation rates ranged from 0.15 μg N L−1 d−1 to 2.7 μg N L−1 d−1 (0.011–0.19 μM d−1), and the mean for intermediate depths was 0.94 μg N L−1 d−1 (0.067 μM d−1). Given that winters with shorter ice duration (< 120 d) have become more frequent in these lakes since the late 1990s, peak winter nitrate concentrations and cumulative nitrate production under ice may be declining. As ice extent and duration change, the physical and chemical conditions supporting life will shift. This research suggests we may expect changes in the form and amount of inorganic N, and altered dissolved nitrogen : phosphorus ratios, in lakes during winters with shorter ice duration.
Surface Modification of Electrospun TPU Nanofiber Scaffold with CNF Particles by Ultrasound‐Assisted Technique for Tissue Engineering
Authors: Ye Jianhua , Si Junhui , Cui Zhixiang , Wang Qianting , Peng Kaiping , Chen Wenzhe , Peng Xiangfang , Chen Shia‐Chung
Published: September 2017

A straightforward, fast, and versatile technique is developed to fabricate nanofibrous scaffold with excellent hydrophilicity, mechanical properties, and biocompatibility for tissue engineering. The thermoplastic polyurethane (TPU) nanofiber is fabricated by utilizing electrospinning, and then its surface is modified through simply immersing it into cellulose nanofibrils (CNF) dispersion and subjecting to ultrasonication. The results show that the CNF particles are successfully absorbed on the surface of TPU nanofiber. By introducing CNF particles on the surface of TPU nanofiber, the hydrophilicity, mechanical properties of fabricated CNF‐absorbed TPU scaffold are significantly increased. Additionally, the adhesion and proliferation of human umbilical vein endothelial cells cultured on CNF‐absorbed TPU scaffold are prominently enhanced in comparison with those of cultured on TPU scaffold. These findings suggest that the ultrasound‐assisted technique opens up a new way to simply and effectively modify the surface of various scaffolds and the modified scaffold could be shown a great potential in tissue engineering.
Aspartate tightens the anchoring of staphylococcal lipoproteins to the cytoplasmic membrane
Authors: Kumari Nimerta , Götz Friedrich , Nguyen Minh‐Thu
Published: September 2017

In gram‐negative bacteria, the ABC transporter LolCDE complex translocates outer membrane‐specific lipoproteins (Lpp) from the inner membrane to the outer membrane. Lpp possessing aspartate (Asp) at position +2 are not translocated because it functions as a LolCDE avoidance signal. In gram‐positive bacteria, lacking an outer membrane and the Lol system, Lpp are only anchored at the outer leaflet of the cytoplasmic membrane. However, the release of Lpp particularly in pathogenic or commensal species is crucial for immune modulation. Here, we provide evidence that in Staphylococcus aureus Asp at position +2 plays a role in withholding Lpp to the cytoplasmic membrane. Screening of published exoproteomic data of S. aureus revealed that Lpp mainly with Gly or Ser at position +2 were found in exoproteome, but there was no Lpp with Asp+2. The occurrence of Lpp with Asp+2 is infrequent in gram‐positive bacteria. In S. aureus USA300 only seven of the 67 Lpp possess Asp+2; among them five Lpp represented Lpl lipoproteins involved in host cell invasion. Our study demonstrated that replacing the Asp+2 present in Lpl8 with a Ser enhances its release into the supernatant. However, there is no different release of Asp+2 and Ser+2 in mprF mutant that lacks the positive charge of lysyl‐phosphatidylglycerol (Lys‐PG). Moreover, substitution of Ser+2 by Asp in SitC (MntC) did not lead to a decreased release indicating that in staphylococci positions +3 and +4 might also be important for a tighter anchoring of Lpp. Here, we show that Asp in position +2 and adjacent amino acids contribute in tightening the anchoring of Lpp by interaction of the negative charged Asp with the positive charged Lys‐PG.
Biologically active quinoline and quinazoline alkaloids part I
Authors: Shang Xiao‐Fei , Morris‐Natschke Susan L. , Liu Ying‐Qian , Guo Xiao , Xu Xiao‐Shan , Goto Masuo , Li Jun‐Cai , Yang Guan‐Zhou , Lee Kuo‐Hsiung
Published: September 2017

Quinoline and quinazoline alkaloids, two important classes ofN‐based heterocyclic compounds, have attracted tremendous attention from researchers worldwide since the 19th century. Over the past 200 years, many compounds from these two classes were isolated from natural sources, and most of them and their modified analogs possess significant bioactivities. Quinine and camptothecin are two of the most famous and important quinoline alkaloids, and their discoveries opened new areas in antimalarial and anticancer drug development, respectively. In this review, we survey the literature on bioactive alkaloids from these two classes and highlight research achievements prior to the year 2008 (Part I). Over 200 molecules with a broad range of bioactivities, including antitumor, antimalarial, antibacterial and antifungal, antiparasitic and insecticidal, antiviral, antiplatelet, anti‐inflammatory, herbicidal, antioxidant and other activities, were reviewed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.
Dual‐rotation C‐arm cone‐beam computed tomography to increase low‐contrast detection
Authors: Reshef Aymeric , Riddell Cyril , Trousset Yves , Ladjal Saïd , Bloch Isabelle
Published: September 2017

Purpose

This paper investigates the capabilities of a dual‐rotation C‐arm cone‐beam computed tomography (CBCT) framework to improve non‐contrast‐enhanced low‐contrast detection for full volume or volume‐of‐interest (VOI) brain imaging.

Method

The idea is to associate two C‐arm short‐scan rotational acquisitions (spins): one over the full detector field of view (FOV) at low dose, and one collimated to deliver a higher dose to the central densest parts of the head. The angular sampling performed by each spin is allowed to vary in terms of number of views and angular positions. Collimated data is truncated and does not contain measurement of the incoming X‐ray intensities in air (air calibration). When targeting full volume reconstruction, the method is intended to act as a virtual bow‐tie. When targeting VOI imaging, the method is intended to provide the minimum full detector FOV data that sufficiently corrects for truncation artifacts. A single dedicated iterative algorithm is described that handles all proposed sampling configurations despite truncation and absence of air calibration.

Results

Full volume reconstruction of dual‐rotation simulations and phantom acquisitions are shown to have increased low‐contrast detection for less dose, with respect to a single‐rotation acquisition. High CNR values were obtained on 1% inserts of the Catphan 515 module in 0.94 mm thick slices. Image quality for VOI imaging was preserved from truncation artifacts even with less than 10 non‐truncated views, without using the sparsity a priori common to such context.

Conclusion

A flexible dual‐rotation acquisition and reconstruction framework is proposed that has the potential to improve low‐contrast detection in clinical C‐arm brain soft‐tissue imaging.
Assessment of the spectral performance of hybrid photon counting x‐ray detectors
Authors: Trueb Peter , Zambon Pietro , Broennimann Christian
Published: September 2017

Purpose

Hybrid Photon Counting (HPC) detectors profoundly improved x‐ray diffraction experiments at third generation synchrotron facilities. Enabling the simultaneous measurement of x‐ray intensities in multiple energy bins, they also have many potential applications in the field of medical imaging. A prerequisite for this is a clean spectral response. To quantify how efficiently HPC detectors are able to assign photons to the correct energy bin, a quantity called Spectral Efficiency (SE) is introduced. This figure of merit measures the number of x‐rays with correctly assigned energy normalized to the number of incoming photons.

Methods

A prototype HPC detector has been used to perform precision measurements of x‐ray spectra at the BESSY synchrotron. The detector consists of a novel ASIC with pixels of 75 × 75 μm2 size and a 750 μm thick CdTe sensor. The experimental data are complemented by the results of a Monte‐Carlo (MC) simulation, which not only includes the physical detection process but also pulse pile‐up at high photon fluxes. The spectra and the measured photon flux are used to infer the Spectral Efficiency.

Results

In the energy range from 10 to 60 keV, both the Quantum Efficiency and the Spectral Efficiency were precisely measured and simulated. Good agreement between simulation and experiment has been achieved. For the small pixels of the prototype detector, a SE between 15% and 77% has been determined. The MC simulation is used to predict the SE for various pixel sizes at different photon fluxes. For a typical flux of 5∙107 photons/mm2/s used in human Computed Tomography (CT), the highest SE is achieved for pixel sizes in the range between 150 × 150 μm2 and 300 × 300 μm2.

Conclusions

The Spectral Efficiency turns out to be a useful figure of merit to quantify the spectral performance of HPC detectors. It allows a quantitative comparison of detectors with different sensor and ASIC configurations over a broad range of x‐ray energies and fluxes. The maximization of the SE is a prerequisite for a successful usage of HPC detectors in the field of medical imaging.
Optimization of the geometry and speed of a moving blocker system for cone‐beam computed tomography scatter correction
Authors: Chen Xi , Ouyang Luo , Yan Hao , Jia Xun , Li Bin , Lyu Qingwen , Zhang You , Wang Jing
Published: September 2017

Purpose

X‐ray scatter is a significant barrier to image quality improvements in cone‐beam computed tomography (CBCT). A moving blocker‐based strategy was previously proposed to simultaneously estimate scatter and reconstruct the complete volume within the field of view (FOV) from a single CBCT scan. A blocker consisting of lead stripes is inserted between the X‐ray source and the imaging object, and moves back and forth along the rotation axis during gantry rotation. While promising results were obtained in our previous studies, the geometric design and moving speed of the blocker were set empirically. The goal of this work is to optimize the geometry and speed of the moving block system.

Methods

Performance of the blocker was examined through Monte Carlo (MC) simulation and experimental studies with various geometry designs and moving speeds. All hypothetical designs employed an anthropomorphic pelvic phantom. The scatter estimation accuracy was quantified by using lead stripes ranging from 5 to 100 pixels on the detector plane. An iterative reconstruction based on total variation minimization was used to reconstruct CBCT images from unblocked projection data after scatter correction. The reconstructed image was evaluated under various combinations of lead strip width and interspace (ranging from 10 to 60 pixels) and different moving speed (ranging from 1 to 30 pixels per projection).

Results

MC simulation showed that the scatter estimation error varied from 0.8% to 5.8%. Phantom experiment showed that CT number error in the reconstructed CBCT images varied from 13 to 35. Highest reconstruction accuracy was achieved when the strip width was 20 pixels and interspace was 60 pixels and the moving speed was 15 pixels per projection.

Conclusions

Scatter estimation can be achieved in a large range of lead strip width and interspace combinations. The moving speed does not have a very strong effect on reconstruction result if it is above 5 pixels per projection. Geometry design of the blocker affected image reconstruction accuracy more. The optimal geometry of the blocker has a strip width of 20 pixels and an interspace three times the strip width, which means 25% detector is covered by the blocker, while the optimal moving speed is 15 pixels per projection.
A service‐agnostic method for predicting service metrics in real time
Authors: Yanggratoke Rerngvit , Ahmed Jawwad , Ardelius John , Flinta Christofer , Johnsson Andreas , Gillblad Daniel , Stadler Rolf
Published: September 2017

We predict performance metrics of cloud services using statistical learning, whereby the behaviour of a system is learned from observations. Specifically, we collect device and network statistics from a cloud testbed and apply regression methods to predict, in real‐time, client‐side service metrics for video streaming and key‐value store services. Results from intensive evaluation on our testbed indicate that our method accurately predicts service metrics in real time (mean absolute error below 16% for video frame rate and read latency, for instance). Further, our method is service agnostic in the sense that it takes as input operating systems and network statistics instead of service‐specific metrics. We show that feature set reduction significantly improves the prediction accuracy in our case, while simultaneously reducing model computation time. We find that the prediction accuracy decreases when, instead of a single service, both services run on the same testbed simultaneously or when the network quality on the path between the server cluster and the client deteriorates. Finally, we discuss the design and implementation of a real‐time analytics engine, which processes streams of device statistics and service metrics from testbed sensors and produces model predictions through online learning.
Consistent development of a beam‐to‐beam contact algorithm via the curve‐to‐solid beam contact: Analysis for the nonfrictional case
Authors: Konyukhov Alexander , Mrenes Oana , Schweizerhof Karl
Published: September 2017

Beam‐to‐beam contact can be dually described depending on the scale as contact between curves or contact between surfaces. The surface‐to‐surface algorithm requires a computationally expensive continuum description of the beams. The curve‐to‐curve contact algorithm is generated from the corresponding closest point projection procedure determining a minimal distance between curves and involves less expensive beam finite elements.

The existence and uniqueness criterion of the closest point projection procedure formulated already in earlier publications is analyzed in detail, especially in the case of multiple solutions for “parallel curves.” It is shown that the curve‐to‐curve contact algorithm cannot be applied for general parallel curves, which can be generated in an arbitrary range of angles between the tangent lines. A new curve‐to‐solid beam contact algorithm is here developed. This algorithm requires a special solid‐beam finite element and is combining the advantages of surface contact together with the flexibility of the application to beam‐to‐beam contact.

Further, a special case with “parallel tangent” vectors is considered from the classical Hertzian contact problem. It is found numerically that the corresponding length of a contact zone is well correlated with the Hertz theory. A possible application of the developed strategy for wire ropes is analyzed numerically.
Food Rituals and Their Social Significance in the Mid‐Second Millennium BC in the Southern Levant: A View From Megiddo
Authors: Sapir‐Hen L. , Martin M. A. S. , Finkelstein I.
Published: September 2017

Ceremonies involving intentional burial of animals with humans are acknowledged to bear religious, social and political connotations, and we explored both the ritual activity and the social trajectory of these activities. To date, these ceremonies have rarely been examined within the context of nearby daily activities. We studied faunal remains associated with intramural burials in comparison with contemporaneous daily life in the midsecond millennium bc at Tel Megiddo, as well as comparison with concomitant extramural burials and locations of public feasts. Our study highlights the human interaction with animals that are not often treated as bearing social meaning or having interrelationships with human, the livestock animals. We demonstrate that livestock animals in the second millennium bc had a significant social role as well as economic value. The choice of animals consumed and sacrificed in these rituals is strongly related to the animal's symbolic potency and is based on the desired social message that the population aims to convey. Finally, the form of luxury food that is found in the Megiddo funerary rituals supports the hypothesis regarding the intramural burials' role in creating and enhancing social family bonds. Copyright © 2017 John Wiley & Sons, Ltd.
Proteomics Insights into Autophagy
Authors: Cudjoe Emmanuel K. , Saleh Tareq , Hawkridge Adam M. , Gewirtz David A.
Published: September 2017

Autophagy, a conserved cellular process by which cells recycle their contents either to maintain basal homeostasis or in response to external stimuli, has for the past two decades become one of the most studied physiological processes in cell biology. The 2016 Nobel Prize in Medicine and Biology awarded to Dr. Ohsumi Yoshinori, one of the first scientists to characterize this cellular mechanism, attests to its importance. The induction and consequent completion of the process of autophagy results in wide ranging changes to the cellular proteome as well as the secretome. MS‐based proteomics affords the ability to measure, in an unbiased manner, the ubiquitous changes that occur when autophagy is initiated and progresses in the cell. The continuous improvements and advances in mass spectrometers, especially relating to ionization sources and detectors, coupled with advances in proteomics experimental design, has made it possible to study autophagy, among other process, in great detail. Innovative labeling strategies and protein separation techniques as well as complementary methods including immuno‐capture/blotting/staining have been used in proteomics studies to provide more specific protein identification. In this review, we will discuss recent advances in proteomics studies focused on autophagy.
Ethylene/POSS copolymerization behavior of postmetallocene catalysts and copolymer characteristics
Authors: Groch Paweł , Dziubek Katarzyna , Czaja Krystyna , Białek Marzena , Adamczyk‐Tomiak Katarzyna , Rabiej Stanisław , Dudziec Beata
Published: September 2017

Copolymerization of ethylene with iso‐butyl substituted monoalkenyl(siloxy)‐ or monoalkenylsilsesquioxane (POSS) comonomers over bis(phenoxy‐imine) and salen‐type titanium and zirconium catalysts was studied. It was found that the polyreaction performance was significantly depended by the kind of the catalyst and by the structure and concentration of POSS in the feed. The POSS comonomer was efficiently incorporated into the polymer chain at up to 0.2 mol %. The differences in the copolymer compositions as the functions of the catalyst kind and the POSS comonomer were observed, including the varied number‐average sequence length of ethylene and unsaturated end groups, as determined by 1H NMR and FT‐IR. The presence of POSS comonomers affected also the melting and crystallization behavior of the copolymers, as evidenced by DSC, because of influence on the polymer chain arrangement. The POSS units could act as the nucleating agents. Moreover, the crystal and structural parameters of ethylene/POSS copolymers were evaluated on the basis of X‐ray results, and the limited self‐aggregation of POSS incorporated into the polymer chain, the small number and size of POSS aggregates, and the increased crystallinity degree of copolymers were demonstrated. The ethylene/POSS copolymers produced by postmetallocenes offered also high thermal stability and interesting morphological properties. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3918–3934
High diffusion barrier and piezoelectric nanocomposites based on polyvinylidene fluoride‐trifluoroethylene copolymer and hydrophobized clay
Authors: Dalle Vacche Sara , Oliveira Fabiane , Sereda Olha , Neels Antonia , Dommann Alex , Damjanovic Dragan , Leterrier Yves
Published: September 2017

Nanocomposites based on polyvinylidene fluoride–trifluoroethylene copolymer and up to 4 vol % of hydrophobized clay nanoparticles are investigated. The structure, piezoelectric properties, and oxygen permeability of solvent cast films are analyzed before and after annealing above the Curie temperature of the polymer. Exfoliation of the clay takes place at concentrations up to 1 vol %, beyond which it rapidly drops and is absent at a concentration of 4 vol %. The presence of clay does not change the crystallinity of the polymer, but leads to a threefold decrease of the oxygen permeability at a concentration of 0.5 vol %. Annealing at 130 °C increases the crystallinity, the proportion of β phase up to 94%, and the piezoelectric coefficient by 20–40% at clay fractions below 1 vol %. Annealing also leads to a remarkable 3‐ to 10‐fold decrease of O2 permeability and to intriguing changes of the activation energy for O2 transport, which decreases from 56 kJ/mol for the as‐cast polymer to below 10 kJ/mol for the polymer and exfoliated composite. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1828–1836
Controlling Reduction Kinetics in the Galvanic Replacement Involving Metal Oxides Templates: Elucidating the Formation of Bimetallic Bowls, Rattles, and Dendrites from Cu2O Spheres
Authors: Rodrigues Thenner S. , da Silva Anderson G. M. , Alves Rafael S. , de Freitas Isabel C. , Oliveira Daniela C. , Camargo Pedro H. C.
Published: September 2017

This study demonstrates that the precursor reduction kinetics can be employed to control the morphology and composition of bimetallic metal/metal oxides systems obtained by galvanic replacement reaction using metal oxides as sacrificial templates. This work investigated Cu2O as a proof‐of‐concept example, in which the relative rates of Cu2O oxidation by O2 and by noble metal precursors determined the morphology and composition of the products. We focused on three metal precursors with fast, medium, and slow reduction kinetics in the presence of Cu2O under aerobic conditions: , , and Ru3+, respectively. It was found that metal‐oxide‐based bowls, rattles, or dendrites can be obtained by simply changing the precursor reduction kinetics. These results provide novel insights over the versatility and mechanistic understanding of galvanic replacement to the synthesis of metal/metal‐oxide bimetallic nanoparticles.
The SubCons webserver: A user friendly web interface for state‐of‐the‐art subcellular localization prediction
Authors: Salvatore M. , Shu N. , Elofsson A.
Published: September 2017

SubCons is a recently developed method that predicts the subcellular localization of a protein. It combines predictions from four predictors using a Random Forest classifier. Here, we present the user‐friendly web‐interface implementation of SubCons. Starting from a protein sequence, the server rapidly predicts the subcellular localizations of an individual protein. In addition, the server accepts the submission of sets of proteins either by uploading the files or programmatically by using command line WSDL API scripts. This makes SubCons ideal for proteome wide analyses allowing the user to scan a whole proteome in few days. From the web page, it is also possible to download precalculated predictions for several eukaryotic organisms. To evaluate the performance of SubCons we present a benchmark of LocTree3 and SubCons using two recent mass‐spectrometry based datasets of mouse and drosophila proteins. The server is available at http://subcons.bioinfo.se/
Early flowering and rapid grain filling determine early maturity and escape from harvesting in weedy rice
Authors: Zhao Can , Xu Wenrong , Song Xiaoling , Dai Weimin , Dai Lei , Zhang Zheng , Qiang Sheng
Published: September 2017

BACKGROUND

Early maturity is an important trait that is essential to the survival of weedy rice. To explore the mechanism of early maturity in weedy rice, the reproductive development of a large sample of weedy rice accessions and cultivars was compared in a common garden study. A selected sample of both weedy and cultivated rice was sown at different dates in two years to study in more detail their flowering and grain‐filling patterns.

RESULTS

The weedy rice from three major cropping regions matured 7‐8 days earlier than their associated cultivars. Representative weedy rice accessions planted on conventional sowing dates flowered 3‐26 days earlier than cultivars; delayed sowing caused divergence in the flowering regimes in weedy rice. However, regardless of the sowing date, weedy rice filled its grain 7‐21 days faster than cultivars in both study years. Vegetative and reproductive traits of weedy and cultivated rice have different patterns of variation with delayed planting.

CONCLUSION

Early maturity is an essential factor determining the persistence of weedy rice by contributing to the escape of its seed from being harvested with the rice crop. Both early flowering and shorter grain‐filling stages determine early maturity, and flowering is more plastic than grain filling. © 2017 Society of Chemical Industry
Improving Performance of Algan‐Based Deep‐Ultraviolet Light‐Emitting Diodes by Inserting a Higher Al‐Content Algan Layer Within the Multiple Quantum Wells
Authors: Lu Lin , Wan Zhi , Xu Fu Jun , Shen Bo , Lv Chen , Jiang Ming , Chen Qi Gong
Published: September 2017

Characteristics of AlGaN‐based deep‐ultraviolet light‐emitting diodes (DUV‐LEDs) with light‐emitting wavelength around 265 nm are investigated by inserting a higher Al‐content AlGaN layer within the multiple quantum wells (MQWs). It is found that there is a significant enhancement of light output power (LOP) and efficiency droop for DUV‐LEDs with the inserted higher Al‐content AlGaN layer compared to those with the conventional one. The location of the AlGaN layer with higher Al‐content in the MQWs is proven to greatly affect the distribution of carriers and the overlap of electron and hole wave functions. The optimal structure can be achieved when the higher Al‐content layer is placed on the right side within the MQWs. The key factors for the performance improvements for this specific design is the enhanced hole transport and reduced electron leakage.
Ridge‐Valley Nanostructured Samaria‐Doped Ceria Interlayer for Thermally Stable Cathode Interface in Low‐Temperature Solid Oxide Fuel Cell
Authors: Kim Hyong June , Yu Jin‐Geun , Hong Soonwook , Park Chan Hyung , Kim Young‐Beom , An Jihwan
Published: September 2017

Agglomeration of the metal electrode decreases the performance of low‐temperature solid oxide fuel cells (LT‐SOFC) during operation at elevated temperatures. Here, we report a Pt electrode/ridge‐valley nanostructured samaria‐doped ceria (SDC) layer interface with extended lifetime. LT‐SOFCs with RF‐sputtered SDC interlayers with thicknesses in the range 65–260 nm show a >20 times lower degradation of performance as compared to cells without interlayer when operated at 450 °C (1.8% h−1 vs. 45% h−1). Micromorphological analysis reveals that the coarsening of the Pt electrode is significantly suppressed by the presence of the nanostructured SDC interlayer, possibly due to a stronger bonding between this layer and the Pt grains.