bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo measurements of limbic glutamate and GABA concentrations in epileptic patients during affective and cognitive tasks: A microdialysis study
Authors: Buchanan Robert J. , Gjini Klevest , Modur Pradeep , Meier Kevin T. , Nadasdy Zoltan , Robinson Jennifer L. 
Published: November 2015

ABSTRACTLimbic system structures such as the amygdala (AMG) and the hippocampus (HIPP) are involved in affective and cognitive processing. However, because of the limitations in noninvasive technology, absolute concentrations of the neurotransmitters underlying limbic system engagement are not known. Here, we report changes in the concentrations of the neurotransmitters glutamate (Glu) and gamma‐aminobutyric acid (GABA) in the HIPP and the AMG of patients with nonlesional temporal lobe epilepsy undergoing surgery for intracranial subdural and depth electrode implantation. We utilized an in‐vivo microdialysis technique while subjects were engaged in cognitive tasks with or without emotional content. The performance of an emotion learning task (EmoLearn) was associated with a significant increase in the concentration of glutamate in the HIPP when images with high valence content were processed, as compared to its concentration while processing images with low valence. In addition, significantly decreased levels of glutamate were found in the AMG when images with predominantly low valence content were processed, as compared to its concentration at baseline. The processing of face stimuli with anger/fear content (FaceMatch task) was accompanied with significantly decreased concentrations of GABA in the AMG and HIPP compared to its levels at the baseline. The processing of shapes on the other hand was accompanied with a significantly decreased concentration of the glutamate in the AMG as well as in the HIPP compared to the baseline. Finally, the performance of a nondeclarative memory task (weather prediction task—WPT) was associated with relatively large and opposite changes in the GABA levels compared to the baseline in the AMG (decrease) and the HIPP (increase). These data are relevant for showing an involvement of the amygdala and the hippocampus in emotional processing and provide additional neurochemical clues towards a more refined model of the functional circuitry of the human limbic system. © 2015 Wiley Periodicals, Inc.
Dissociable contributions of amygdala and hippocampus to emotion and memory in patients withAlzheimer's disease
Authors: Guzmán‐Vélez Edmarie , Warren David E. , Feinstein Justin S. , Bruss Joel , Tranel Daniel 
Published: November 2015

AbstractThe amygdala and the hippocampus are associated with emotional processing and declarative memory, respectively. Studies have shown that patients with bilateral hippocampal damage caused by anoxia/ischemia, and patients with probable Alzheimer's disease (AD), can experience emotions for prolonged periods of time, even when they cannot remember what caused the emotion in the first place (Feinstein et al. (2010) Proc Natl Acad Sci USA 107:7674‐7679; Guzmán‐Vélez et al. (2014) Cogn Behav Neurol 27:117‐129). This study aimed to investigate, for the first time, the roles of the amygdala and hippocampus in the dissociation between feelings of emotion and declarative memory for emotion‐inducing events in patients with AD. Individuals with probable AD (N = 12) and age‐matched healthy comparisons participants (HCP;N = 12) completed a high‐resolution (0.44 × 0.44 × 0.80 mm) T2‐weighted structural MR scan of the medial temporal lobe. Each of these individuals also completed two separate emotion induction procedures (sadness and happiness) using film clips. We collected real‐time emotion ratings at baseline and multiple times postinduction, and administered a test of declarative memory shortly after each induction. Consistent with previous research, hippocampal volume was significantly smaller in patients with AD compared with HCP, and was positively correlated with memory for the film clips. Sustained feelings of emotion and amygdala volume did not significantly differ between patients with AD and HCP. Follow‐up analyses showed a significant negative correlation between amygdala volume and sustained sadness, and a significant positive correlation between amygdala volume and sustained happiness. Our findings suggest that the amygdala is important for regulating and sustaining an emotion independent of hippocampal function and declarative memory for the emotion‐inducing event. © 2015 Wiley Periodicals, Inc.
The Way to the Top: Career Patterns of Fortune 100 CEOS
Authors: Koch Michael , Forgues Bernard , Monties Vanessa 
Published: November 2015

AbstractHow have theCEOsof Fortune 100 companies worked their way to the top position? Are there several paths to the top, or have most present‐dayCEOsmoved up the ranks in a similar fashion? We examine the employment trajectories of all of the current Fortune 100CEOsacross their entire working careers to answer these questions. The analysis developed in this article is carried out in two steps. We first use sequence analysis to find the patterns that are characteristic of the career paths of theseCEOs. We then apply clustering techniques to identify distinct groups of career paths that have led individuals to the uppermost management level. Our results show that the careers of the Fortune 100CEOshave largely followed traditional career paths that are symbolized by steady progression toward more responsibility, little mobility between firms and industries, and a strong focus on general management functions. © 2015 Wiley Periodicals, Inc.
Executive Pay Matters: Looking Beyond the CEO to Explore Implications of Pay Disparity on Non‐CEO Executive Turnover and Firm Performance
Authors: Pissaris Seema , Heavey Angela , Golden Peggy 
Published: November 2015

AbstractUsing a longitudinal data set covering a span of 10 years, we investigate the impact of vertical and horizontal pay disparity on non‐CEO executive turnover and subsequent firm performance. Hypothesizing differential responses to pay disparity depending on a non‐CEO executive's responsibilities, we first categorize non‐CEO executives based on their job demands and their role in the organization (e.g., oversight, divisional). We then explore how pay disparity influences the relationship between executive category and turnover, and how the level of pay disparity impacts the relationship between turnover and firm performance. We find that executive category significantly impacts the likelihood of turnover, and also influences firm performance. Theoretical and practical implications are discussed. © 2015 Wiley Periodicals, Inc.
Effects of trematode parasitism on the shell morphology of snails from flow and nonflow environments
Authors: Gustafson Kyle D. , Bolek Matthew G. 
Published: November 2015

ABSTRACTThe primary function of the gastropod shell is protection. However, shells that function well in one environment may be maladaptive in another. Upon infection, the snail shell protects internal parasites and it is to the parasite's advantage to optimize, or not interfere with, shell functionality. However, parasites, particularly trematodes, are often pathogenic and it is not clear if parasitism will induce environment‐dependent or ‐independent changes to gastropod shells. We conducted a field study and a complementary laboratory experiment to examine the effects of trematode parasitism on shell characteristics (shape, size, and crush resistance) of Physa acuta snails in flow and nonflow environments using geometric morphometrics and crush assays. Field results indicate wetland (nonflow) snails had large, crush resistant shells with narrow apertures and tall spires. In contrast, stream (flow) snails had small, weak shells with wide apertures and short spires. Parasitism had no apparent effect on the crush resistance of wetland snails but significantly reduced the crush resistance of stream snails. Parasitism had no significant effect on overall shell shape in stream or wetland snails. Similar to the results of our field study, nonflow tank snails had significantly more crush resistant shells than flow tank snails. Additionally, the shapes of flow and nonflow tank snails significantly differed where nonflow tank snails resembled wetland snails and flow tank snails resembled stream snails. For laboratory snails, parasitism reduced crush resistance regardless of flow/nonflow treatment. Our results demonstrate that habitat and/or flow treatment was the primary factor affecting P. acuta shell morphology and that trematode parasitism played a secondary role. J. Morphol. 277:316–325, 2016. © 2015 Wiley Periodicals, Inc.
Quantitative analysis of tibial subchondral bone: Texture analysis outperforms conventional trabecular microarchitecture analysis
Authors: MacKay James W. , Murray Philip J. , Low Samantha B. L. , Kasmai Bahman , Johnson Glyn , Donell Simon T. , Toms Andoni P. 
Published: November 2015

BackgroundThe aim of this study was to compare two different methods of quantitative assessment of tibial subchondral bone in osteoarthritis (OA): statistical texture analysis (sTA) and trabecular microarchitecture analysis (tMA).MethodsAsymptomatic controls aged 20–30 (n = 10), patients aged 40–50 with chronic knee pain but without established OA (n = 10) and patients aged 55–85 with advanced OA scheduled for knee replacement (n = 10) underwent knee MR imaging at 3 Tesla with a three‐dimensional gradient echo sequence to allow sTA and tMA. tMA and sTA features were calculated using region of interest creation in the medial (MT) and lateral (LT) tibial subchondral bone. Features were compared between groups using one‐way analysis of variance. The two most discriminating tMA and sTA features were used to construct exploratory discriminant functions to assess the ability of the two methods to classify participants.ResultsNo tMA features were significantly different between groups at either MT or LT. 17/20 and 11/20 sTA features were significantly different between groups at the MT/LT, respectively (P < 0.001). Discriminant functions created using tMA features classified 12/30 participants correctly (40% accuracy; 95% confidence interval [CI], 22–58%) based on MT data and 9/30 correctly (30%,; 95% CI, 14–46) based on LT data. Discriminant functions using sTA features classified 16/30 participants correctly (53%; 95% CI, 35–71) based on MT data and 14/30 correctly (47%; 95% CI, 29–65) based on LT data.ConclusionsTA features showed more significant differences between the three study groups and improved classification accuracy compared with tMA features. J. Magn. Reson. Imaging 2016;43:1159–1170.
Utility of histogram analysis of apparent diffusion coefficient maps obtained using 3.0T MRI for distinguishing uterine carcinosarcoma from endometrial carcinoma
Authors: Takahashi Masahiro , Kozawa Eito , Tanisaka Megumi , Hasegawa Kousei , Yasuda Masanori , Sakai Fumikazu 
Published: November 2015

PurposeWe explored the role of histogram analysis of apparent diffusion coefficient (ADC) maps for discriminating uterine carcinosarcoma and endometrial carcinoma.Materials and MethodsWe retrospectively evaluated findings in 13 patients with uterine carcinosarcoma and 50 patients with endometrial carcinoma who underwent diffusion‐weighted imaging (b = 0, 500, 1000 s/mm2) at 3T with acquisition of corresponding ADC maps. We derived histogram data from regions of interest drawn on all slices of the ADC maps in which tumor was visualized, excluding areas of necrosis and hemorrhage in the tumor. We used the Mann–Whitney test to evaluate the capacity of histogram parameters (mean ADC value, 5th to 95th percentiles, skewness, kurtosis) to discriminate uterine carcinosarcoma and endometrial carcinoma and analyzed the receiver operating characteristic (ROC) curve to determine the optimum threshold value for each parameter and its corresponding sensitivity and specificity.ResultsCarcinosarcomas demonstrated significantly higher mean vales of ADC, 95th, 90th, 75th, 50th, 25th percentiles and kurtosis than endometrial carcinomas (P < 0.05). ROC curve analysis of the 75th percentile yielded the best area under the ROC curve (AUC; 0.904), sensitivity of 100%, and specificity of 78.0%, with a cutoff value of 1.034 × 10‐3 mm2/s.ConclusionHistogram analysis of ADC maps might be helpful for discriminating uterine carcinosarcomas and endometrial carcinomas. J. Magn. Reson. Imaging 2016;43:1301–1307.
Natural history and treatment trends in hepatocellular carcinoma subtypes: Insights from a national cancer registry
Authors: Jernigan Peter L. , Wima Koffi , Hanseman Dennis J. , Hoehn Richard S. , Ahmad Syed A. , Shah Shimul A. , Abbott Daniel E. 
Published: November 2015

BackgroundHistopathologic advancements have identified several rare subtypes of hepatocellular carcinoma (HCC), but the clinical significance of these distinctions is incompletely understood. Our aim was to investigate pathologic and treatment differences between HCC variants.MethodsThe American College of Surgeons National Cancer Data Base (1998–2011) was queried to identify 784 patients with surgical management of six rare HCC subtypes: fibrolamellar (FL, n = 206), scirrhous (SC, n = 29), spindle cell (SP, n = 20), clear cell (CC, n = 169), mixed type (M, n = 291), and trabecular (T, n = 69). We examined associations between demographic, tumor and treatment‐specific variables, and overall survival (OS).ResultsPatients with FL‐HCC were younger than other variants (median age 27 vs. 54–61, P < 0.001), more commonly female (56.3%, P < 0.001), and less likely to receive a transplant (3.66%, P < 0.001). Patients with FL‐ and Sp‐HCC presented more frequently with larger tumors (>5 cm, P < 0.001) and node‐positive disease (P < 0.001). Better OS was associated with lower pathologic stage, node‐negative disease, FL‐HCC, and liver transplant. Adjuvant therapy (11% of patients) was not associated with better OS.ConclusionsThis largest series of recognized HCC variants demonstrates distinct differences in presentation, treatment, and prognosis. These findings can provide a valuable reference for clinicians and patients who encounter these rare clinical entities. J. Surg. Oncol. 2015;112:872–876. © 2015 Wiley Periodicals, Inc.
Use of a mobile tower‐based robot—The initial Xi robot experience in surgical oncology
Authors: Yuh Bertram , Yu Xian , Raytis John , Lew Michael , Fong Yuman , Lau Clayton 
Published: November 2015

Background and ObjectivesThe da Vinci Xi platform provides expanded movement of the arms relative to the base, theoretically allowing increased versatility in complex multi‐field or multi‐quadrant surgery. We describe the initial Xi experience in oncologic surgery at a tertiary cancer center.MethodsOne hundred thirty unique robot‐assisted procedures were performed using the Xi between 2014 and 2015, 112 of which were oncology surgeries. For procedures involving multiple quadrants, the robot was re‐targeted. Complications were assessed according to Martin criteria and the Clavien–Dindo classification up to 90 days after operation.ResultsThirteen different operations were performed in five oncology subspecialties (urology, gynecology, thoracic, hepatobiliary, and gastrointestinal surgery). Median operative times ranged from 183 min for nephroureterectomy to 543 min for esophagogastrectomy. Median estimated blood loss did not exceed 200 ml for any of the categorized procedures . No patients were transfused intraoperatively and no positioning injuries occurred. Conversions to open operation occurred in three cases (2.7%), though not related to complications or technical considerations. Overall complication rate was 26% with major complication rate of 4%. Readmissions were necessary in 11 (10%) patients.ConclusionsThe da Vinci Xi can be safely assimilated into a surgical oncology program. The Xi offers versatility to various oncologic procedures with satisfactory complication and readmission rates. J. Surg. Oncol. 2016;113:5–7. © 2015 Wiley Periodicals, Inc.
Radical Chain Polymerization Catalyzed by Graphene Oxide and Cooperative Hydrogen Bonding
Authors: Zhu Zhongcheng , Shi Shengjie , Wang Huiliang 
Published: November 2015

Graphene oxide (GO) is effective in catalyzing a wide variety of organic reactions and a few types of polymerization reactions. No radical chain polymerizations catalyzed by GO have been reported. In this article, we probe the catalytic role and acceleration effect of GO for self‐initiated radical chain polymerizations of acrylic acid (AA) in the presence of GO and a pre‐existing polymer, poly(N‐vinylpyrrolidone) (PVP), from a calorimetric perspective. Gelation experiments and DSC studies show that GO can function as a catalyst to accelerate the radical chain polymerization of AA. Isothermal polymerization kinetic data shows that the addition of GO diminishes the induction periods and increases the polymerization rates, as indicated by the much enhanced overall kinetic rate constants and lowered activation energies. The catalytic effect of GO for the polymerization of AA is attributed to the acidity of GO and the hydrogen bonding interactions between GO and monomer molecules and/or polymers.
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Study of Dielectric Properties of Nanocrystalline Cobalt Ferrite Upto Microwave Frequencies
Authors: Sharma Jyoti , Parashar Jyoti , Saxena V.K. , Bhatnagar D. , Sharma K.B. 
Published: November 2015

SummaryThe dielectric properties of cobalt ferrite, prepared by sol‐gel auto combustion technique, were studied from low frequencies to microwave frequencies. The single phase cubic spinel structure has been confirmed by using X‐ray diffraction (XRD). The dielectric properties of the sample were studied in the low frequency range from 100 Hz to 120 MHz as well as in the high frequency range from 3.95 GHz to 5.85 GHz at room temperature. The dielectric dispersion observed at lower frequency region is due to Maxwell–Wagner two layer model, which is in agreement with Koops phenomenological theory. There is a strong co‐relation between the conduction mechanism and the dielectric behaviour of ferrites. The dielectric constant remains almost constant at microwave frequencies due to the fact that it is contributed by atomic and electronic polarization. The dielectric loss tangent shows two dielectric loss peaks at about 4.332 GHz and 4.525 GHz frequencies.
Dielectric Behaviour of Ni0.2Cu0.2Zn0.6Fe2O4 Spinel Ferrite
Authors: Parashar Jyoti , Saxena V. K. , Sharma Jyoti , Bhatnagar Deepak , Sharma K. B. 
Published: November 2015

SummaryDielectric properties such as dielectric constant (ϵ′) and dielectric loss tangent (tan δ) are reported for Cu substituted Ni‐Zn ferrite having formula Ni0.2Cu0.2Zn0.6Fe2O4 prepared by sol–gel auto combustion method. T he variation of dielectric constant, dielectric loss tangent and A. C. conductivity with frequency are measured in the frequency range 1000 Hz to 120 MHz at room temperature. the real part of dielectric constant decreases with the increase in frequency where as the A. C. conductivity (σac) increases with increase in frequency. The relation of tan δ with frequency shows resonance peak. Dielectric constant as a function of temperature is studied at different temperatures ranging from 353 K to 583 K.
VEGF Cancer Biomarker Protein Detection in Real Human Serum Using Capacitive Label‐Free Aptasensor
Authors: Qureshi Anjum , Roci Irena , Gurbuz Yasar , Niazi Javed H. 
Published: November 2015

SummaryVascular Endothelial Growth Factor (VEGF) is a signalling protein known as a serum biomarker for a number of diseases including cancer. Therefore, it is necessary to develop a label‐free, rapid and sensitive method for detecting VEGF in its native forms in human serum. In this work, we have demonstrated the proof‐of‐concept of a sensitive label‐free biosensor based on capacitance changes induced by capturing of VEGF in human serum using anti‐VEGF aptamers functionalized on interdigitated (IDE) capacitor arrays (aptasensors). Limit of detection of VEGF protein using this aptasensor was in the range 0.5–2 ng/mL in dilute human serum. The label‐free capacitive aptasensing strategy provides a simple, reliable and effective means of biosensing serum VEGF levels for early cancer diagnosis.
Comparative Study of Fe‐Doped ZnO Nanowire Bundle and Their Thin Film for NO2 and CH4 Gas Sensing
Authors: Vyas Rishi , Sharma Sarla , Khan Shabana , Divakar R. , Sachdev K. , Sharma S. K. 
Published: November 2015

SummaryThe free standing Fe‐doped ZnO nanowire bundle is synthesized by employing a typical vapor phase transport method in single step from Fe+Zn powder in O2+Ar flow. Fe‐doped ZnO nanowires are characterized by Transmission Electron Microscopy (TEM) and Energy Dispersive Spectroscopy (EDS) suggesting formation of hexagonal wurtzite phase of ZnO with 7 at% Fe in ZnO with typical nanowire diameter in the range of 20 nm–70 nm. These nanowire bundles are ultrasonicated and processed into thin film using spin coating technique. Both of the Fe‐ doped ZnO nanowire bundle and thin films are tested for their NO2 and CH4 (20–100 ppm) sensing properties. The thin film exhibited higher operating temperature (300°C) and response time (45 sec) as compared to nanowire bundle (150°C and 15 sec).
Investigations on Multilayered TCO as Transparent Electrode in Organic Devices
Authors: Sharma Vikas , Meena Pooja , Salim Amena , Vyas Rishi , Sachdev K. 
Published: November 2015

SummaryA sandwiched structure with a metal layer embedded between two metal oxide layers was fabricated on glass substrate to be used as transparent electrode in organic devices. The oxide layers of ZnO were dip coated with a thickness of about 60 nm each while the metal inter layer was sputter coated with a thickness of about 5 nm at room temperature. The deposited films were annealed at 200°C for 2 hrs to remove all additives. Such structures have been found to be suitable for applications in organic solar cell and OLED. The samples have been characterized using XRD, SEM and EDAX. Optical properties were measured by UV‐VIS and AFM was used to measure the roughness. The XRD pattern indicates the nearly amorphous structure of the thin film. The size of the aggregates as given by FESEM ranges from 30–50 nm and EDAX confirms the presence of elements of the three layers. The roughness as calculated using AFM is about 2.40 nm. UV‐VIS spectroscopy showed a high transparency of over 87% in the visible region for the sandwich structure making it suitable for TCO applications.
Dynamics of Loop Formation in Active Chains
Authors: Sarkar Debarati , Brahmanandan Abhishekamole , Thakur Snigdha 
Published: November 2015

SummaryWe have developed a model of chemically active polymers and investigated the role of activity in loop formation. The active chain contains catalytic and non‐catalytic sites responsible for ring closure. A chemical reaction at the catalytic bead produces a self‐generated concentration gradient and the non‐catalytic bead responds to this gradients which causes these two beads to move towards each other hence forming the loop. Because of this chemotactic response the dynamics of these active polymers are very different from the inactive chain. In particular we show that the loop formation is much more rapid in active chains in comparison to the inactive chains, which rely primarily on diffusion to bring distant portions of the chain in close proximity. Here we will also investigate the effect of macromolecuar crowder particles in loop formation time of such active polymers. The mechanism presented in this paper can be extended to other chemical systems which rely on diffussion to bring reagents into contact for reactions to occur.