bluuebunny/crossref_metadata_2025 huggingface dataset:
Tests and model calibration of high‐strength steel tubular beam‐to‐column and column‐base composite joints for moment‐resisting structures
Authors: Pucinotti Raffaele , Tondini Nicola , Zanon Gabriele , Bursi Oreste S.
Published: January 2015

Performance‐based engineering (PBE) methodologies allow for the design of more reliable earthquake‐resistant structures. Nonetheless, to implement PBE techniques, accurate finite element models of critical components are needed. With these objectives in mind, initially, we describe an experimental study on the seismic behaviour of both beam‐to‐column (BTC) and column‐base (CB) joints made of high‐strength steel S590 circular columns filled with concrete. These joints belonged to moment‐resisting frames (MRFs) that constituted the lateral‐force‐resisting system of an office building. BTC joints were conceived as rigid and of partial strength, whereas CB joints were designed as rigid and of full strength. Tests on a BTC joint composed of an S275 steel composite beam and high‐strength steel concrete‐filled tubes were carried out. Moreover, two seismic CB joints were tested with stiffeners welded to the base plate and anchor bolts embedded in the concrete foundation as well as where part of a column was embedded in the foundation with no stiffeners. A test programme was carried out with the aim of characterising these joints under monotonic, cyclic and random loads. Experimental results are presented by means of both force–interstory drift ratio and moment–rotation relationships. The outcomes demonstrated the adequacy of these joints to be used for MRFs of medium ductility class located in zones of moderate seismic hazard. Then, a numerical calibration of the whole joint subassemblies was successfully accomplished. Finally, non‐linear time‐history analyses performed on 2D MRFs provided useful information on the seismic behaviour of relevant MRFs. Copyright © 2015 John Wiley & Sons, Ltd.
A distributed parameter model of a frame pin‐supported wall structure
Authors: Pan Peng , Wu Shoujun , Nie Xin
Published: January 2015

Many reinforced‐concrete frames collapse via a soft‐story mechanism during severe earthquakes. Such collapses are mainly attributed to concentrated deformation in a soft story. Deformation control is thus important in preventing collapse. The frame pin‐supported wall structure is a type of rocking structure that releases constraints at the bottom of the wall. Previous research has obtained good results for the deformation control of this type of structure. However, the interior forces and strength demands of the pin‐supported wall have not been systematically explored. In this paper, a distributed parameter model is developed to investigate the strength demand of the wall in a frame pin‐supported wall structure. In the model, the pin‐supported wall is simplified as a bending beam and the frame is simplified as a shear beam. The two beams are joined by distributed shear connectors, so that the shear force can be transferred at any location on the interface. The model can be solved using differential equations based on equilibrium and compatibility. The accuracy of the model is verified using SAP2000 (Computers and Structures Inc., Berkeley, CA, USA). Displacement distribution of the structure and distributions of the moment and shear force within the pin‐supported wall are obtained for two typical external force profiles. It is found that the pin‐supported wall can effectively reduce the drift concentration factor. Distributions of the displacement, moment, and shear force are closely correlated with the relative stiffness of the wall and frame. Finally, recommendations on the stiffness and strength of a pin‐supported wall are made. Copyright © 2015 John Wiley & Sons, Ltd.
An effective approach for modeling fluid flow in heterogeneous media using numerical manifold method
Authors: Hu Mengsu , Wang Yuan , Rutqvist Jonny
Published: January 2015

A major challenge of modeling fluid flow in heterogeneous media is to model the material interfaces, which may be arbitrarily oriented or intersected with Dirichlet, Neumann, or other boundaries, making it difficult to mesh and accurately satisfy the boundary constraints. In order to solve these problems, we derived a new continuous approach in the numerical manifold method (NMM). NMM is an ideal method to handle boundaries, considering its flexibility and efficiency with fixed mathematical mesh and its integration precision. With the two‐cover‐meshing system, we construct physical covers containing gradient jump terms defined as extended degrees of freedom to realize the refraction law across material interfaces. In the global equilibrium equations, the jump terms are naturally considered with the energy‐work seepage model. In this approach, high accuracy is expected from the newly constructed jump function together with simplex integration. Moreover, high mesh efficiency is realized by fixed triangular mathematical mesh with algorithms fully considering interfaces intersecting with Dirichlet, Neumann, or other boundaries and simplex integration on elements in arbitrary shapes. The new approach was coded into our NMM fluid flow model. We calculated examples involving fluid flow through a domain including (1) a single interface, (2) an idealized fault represented by multiple material interfaces, (3) intersected interfaces, and (4) an octagonal inclusion. We compared the simulated results to analytical solutions or results with denser mesh to test precision and efficiency and thereby proved that the new approach is accurate, efficient, and flexible, especially when considering intense geometric change or intersections. Copyright © 2015 John Wiley & Sons, Ltd.
Transition from I‐type to A‐type magmatism in the Sanandaj–Sirjan Zone, NW Iran: an extensional intra‐continental arc
Authors: Sarjoughian Fatemeh , Kananian Ali , Haschke Michael , Ahmadian Jamshid
Published: January 2015

The South Dehgolan pluton, in NW Iran was emplaced into the Sanandaj–Sirjan magmatic–metamorphic zone. This composite intrusion comprises three main groups: (1) monzogabbro–monzodiorite rocks, (2) quartz monzonite–syenite rocks, and (3) a granite suite which crops out in most of the area. The granites generally show high SiO2 content from 72.1%–77.6 wt.% with diagnostic mineralogy consisting of biotite and amphibole along the boundaries of feldspar–quartz crystals which implies anhydrous primary magma compositions. The granite suite is metaluminous and distinguished by high FeOt/MgO ratios (av. 9.6 wt.%), typical of ferroan compositions with a pronounced A‐type affinity with high Na2O + K2O contents, high Ga/Al ratios, enrichment in Zr, Nb, REE, and depletion in Eu. The quartz monzonite–syenites show intermediate SiO2 levels (59.8%–64.5 wt.%) with metaluminous, magnesian to ferroan characteristics, intermediate Na2O + K2O contents, enrichment in Zr, Nb, REE, Ga/Al, and depletion in Eu. The monzogabbro–monzodiorites show overall lower SiO2 content (48.5%–55.9 wt.%) with metaluminous and calc‐alkaline compositions, relatively lower Na2O + K2O contents, low Ga/Al ratios, and FeOt/MgO (av. 1.6 wt.%) ratios, low abundances of Zr, Nb, and lower REE element concentrations relative to the granites and quartz monzonite–syenites. These geochemical differences among the three different rocks suites are likely to indicate different melt origins. We suggest that the South Dehgolan pluton resulted from a change in the geodynamic regime, from compression to extension in the Sanandaj–Sirjan zone during Mesozoic subduction of the Neo‐Tethys oceanic crust beneath the Central Iranian microcontinent. Copyright © 2015 John Wiley & Sons, Ltd.
Attenuated portal hypertension in germ‐free mice: Function of bacterial flora on the development of mesenteric lymphatic and blood vessels
Authors: Moghadamrad Sheida , McCoy Kathy D. , Geuking Markus B. , Sägesser Hans , Kirundi Jorum , Macpherson Andrew J. , De Gottardi Andrea
Published: January 2015

Intestinal bacterial flora may induce splanchnic hemodynamic and histological alterations that are associated with portal hypertension (PH). We hypothesized that experimental PH would be attenuated in the complete absence of intestinal bacteria. We induced prehepatic PH by partial portal vein ligation (PPVL) in germ‐free (GF) or mice colonized with altered Schaedler's flora (ASF). After 2 or 7 days, we performed hemodynamic measurements, including portal pressure (PP) and portosystemic shunts (PSS), and collected tissues for histomorphology, microbiology, and gene expression studies. Mice colonized with intestinal microbiota presented significantly higher PP levels after PPVL, compared to GF, mice. Presence of bacterial flora was also associated with significantly increased PSS and spleen weight. However, there were no hemodynamic differences between sham‐operated mice in the presence or absence of intestinal flora. Bacterial translocation to the spleen was demonstrated 2 days, but not 7 days, after PPVL. Intestinal lymphatic and blood vessels were more abundant in colonized and in portal hypertensive mice, as compared to GF and sham‐operated mice. Expression of the intestinal antimicrobial peptide, angiogenin‐4, was suppressed in GF mice, but increased significantly after PPVL, whereas other angiogenic factors remained unchanged. Moreover, colonization of GF mice with ASF 2 days after PPVL led to a significant increase in intestinal blood vessels, compared to controls. The relative increase in PP after PPVL in ASF and specific pathogen‐free mice was not significantly different. Conclusion: In the complete absence of gut microbial flora PP is normal, but experimental PH is significantly attenuated. Intestinal mucosal lymphatic and blood vessels induced by bacterial colonization may contribute to development of PH. (Hepatology 2015;61:1685‐1695)
Four DNA methylation biomarkers in biliary brush samples accurately identify the presence of cholangiocarcinoma
Authors: Andresen Kim , Boberg Kirsten Muri , Vedeld Hege Marie , Honne Hilde , Jebsen Peter , Hektoen Merete , Wadsworth Christopher A. , Clausen Ole Petter , Lundin Knut E.A. , Paulsen Vemund , Foss Aksel , Mathisen Øystein , Aabakken Lars , Schrumpf Erik , Lothe Ragnhild A. , Lind Guro E.
Published: January 2015

Early detection of the highly aggressive malignancy cholangiocarcinoma (CCA) remains a challenge but has the potential to render the tumor curable by surgical removal. This study evaluates a biomarker panel for the diagnosis of CCA by DNA methylation analyses of biliary brush samples. The methylation status of 13 candidate genes (CDO1, CNRIP1, DCLK1, FBN1, INA, MAL, SEPT9, SFRP1, SNCA, SPG20, TMEFF2, VIM, and ZSCAN18) was investigated in 93 tissue samples (39 CCAs and 54 nonmalignant controls) using quantitative methylation‐specific polymerase chain reaction. The 13 genes were further analyzed in a test series of biliary brush samples (15 CCAs and 20 nonmalignant primary sclerosing cholangitis controls), and the methylation status of the four best performing markers was validated (34 CCAs and 34 primary sclerosing cholangitis controls). Receiver operating characteristic curve analyses were used to evaluate the performance of individual biomarkers and the combination of biomarkers. The 13 candidate genes displayed a methylation frequency of 26%‐82% in tissue samples. The four best‐performing genes (CDO1, CNRIP1, SEPT9, and VIM) displayed individual methylation frequencies of 45%‐77% in biliary brushes from CCA patients. Across the test and validation biliary brush series, this four‐gene biomarker panel achieved a sensitivity of 85% and a specificity of 98%, with an area under the receiver operating characteristic curve of 0.944. Conclusion: We report a straightforward biomarker assay with high sensitivity and specificity for CCA, outperforming standard brush cytology, and suggest that the biomarker panel, potentially in combination with cytological evaluation, may improve CCA detection, particularly among primary sclerosing cholangitis patients. (Hepatology 2015;61:1651–1659)
Terlipressin plus albumin versus midodrine and octreotide plus albumin in the treatment of hepatorenal syndrome: A randomized trial
Authors: Cavallin Marta , Kamath Patrick S. , Merli Manuela , Fasolato Silvano , Toniutto Pierluigi , Salerno Francesco , Bernardi Mauro , Romanelli Roberto Giulio , Colletta Cosimo , Salinas Freddy , Di Giacomo Antonio , Ridola Lorenzo , Fornasiere Ezio , Caraceni Paolo , Morando Filippo , Piano Salvatore , Gatta Angelo , Angeli Paolo ,   for the Italian Association for the Study of the Liver Study Group on Hepatorenal Syndrome
Published: January 2015

Hepatorenal syndrome (HRS), a serious complication of cirrhosis, is associated with high mortality without treatment. Terlipressin with albumin is effective in the reversal of HRS. Where terlipressin is not available, as in the United States, midodrine and octreotide with albumin are used as an alternative treatment of HRS. The aim was to compare the effectiveness of terlipressin plus albumin versus midodrine and octreotide plus albumin in the treatment of HRS in a randomized controlled trial. Twenty‐seven patients were randomized to receive terlipressin with albumin (TERLI group) and 22 to receive midodrine and octreotide plus albumin (MID/OCT group). The TERLI group received terlipressin by intravenous infusion, initially 3 mg/24 hours, progressively increased to 12 mg/24 hours if there was no response. The MID/OCT group received midodrine orally at an initial dose of 7.5 mg thrice daily, with the dose increased to a maximum of 12.5 mg thrice daily, together with octreotide subcutaneously: initial dose 100 μg thrice daily and up to 200 μg thrice daily. Both groups received albumin intravenously 1 g/kg of body weight on day 1 and 20‐40 g/day thereafter. There was a significantly higher rate of recovery of renal function in the TERLI group (19/27, 70.4%) compared to the MID/OCT group (6/21, 28.6%), P = 0.01. Improvement in renal function and lower baseline Model for End‐Stage Liver Disease score were associated with better survival. Conclusion: Terlipressin plus albumin is significantly more effective than midodrine and octreotide plus albumin in improving renal function in patients with HRS (Hepatology 2015;62:567–574
A clinicopathological cohort study of liver pathology in 301 patients with human immunodeficiency virus/acquired immune deficiency syndrome
Authors: Sonderup Mark W. , Wainwright Helen , Hall Pauline , Hairwadzi Henry , Spearman C. Wendy N.
Published: January 2015

Liver disease complicates human immunodeficiency virus (HIV)/acquired immune deficiency syndrome; however, liver pathology data are limited, particularly from high HIV prevalence countries. We investigated the spectrum and clinicopathological correlates of liver pathology in a high HIV burden setting. In a single‐center study, all HIV/acquired immune deficiency syndrome patients with complete clinical and demographic data who underwent liver biopsy were analyzed and clinicopathologically assessed by hepatologists and one of two experienced liver pathologists. We evaluated 301 patients, with a median age of 34 (interquartile range 29‐40) years. Women (n = 143) were younger than men (n = 158), with a median age of 33 (interquartile range 28‐37) versus 35 (interquartile range 31‐41) years, P = 0.001. The majority, 76.1%, were black African. Median CD4 at time of biopsy was 127 (52‐260) cells/mm3. Drug‐induced liver injury was the predominant finding (42.2%), followed by granulomatous inflammation (29%), steatosis/steatohepatitis (19.3%), hepatitis B (19%), and hepatitis C coinfection (3.3%), with more than one pathology in 16.2%. With granulomatous inflammation, 52% met the criteria for tuberculosis immune reconstitution syndrome. By univariate analysis, cotrimoxazole and antiretroviral therapy conferred risk for drug injury (odds ratio [OR] = 2.78 [1.72‐4.48], P < 0.001; OR = 1.69 [1.06‐2.68], P = 0.027). In multivariate analysis, cotrimoxazole was associated with a cholestatic or ductopenic injury (OR = 7.05 [2.50‐19.89], P < 0.001; OR = 17.6 [3.26‐95.3], P < 0.0001); efavirenz was associated with nonspecific hepatitis or submassive necrosis (OR = 4.3 [1.92‐9.83], P < 0.001; OR = 10.46 [2.7‐40.5], P < 0.001). Cholestatic injury was associated with female gender and a CD4 of >200 cells/mm3, and submassive necrosis was associated with younger age. Hepatitis B demonstrated no association. Conclusion: In a high HIV burden area, drug‐induced liver injury due to antiretroviral therapy and cotrimoxazole was a frequent clinicopathological finding; Mycobacterium tuberculosis was the leading opportunistic infection, with more than half of patients fulfilling criteria for tuberculosis immune reconstitution syndrome; liver biopsy remains a useful diagnostic procedure in this setting. (Hepatology 2015;61:1721–1729)
Agency, communion and entitlement
Authors: Żemojtel‐Piotrowska Magdalena A. , Piotrowski Jarosław P. , Clinton Amanda
Published: January 2015

In this study, the relationship between agency, communion, and the active, passive, and revenge forms of entitlement is examined. Results indicate that active entitlement was positively related to agency, negatively to communion (Study 1), and unrelated to unmitigated agency and communion (Study 2). Passive entitlement was positively related to communion (in regular and unmitigated forms) and negatively related to agency (in both forms). Revenge entitlement was positively related to agency (unmitigated and regular), and negatively related to both regular and unmitigated communal orientations. Detected relationships were independent from self‐esteem (Study 1). The findings are discussed in relation to distinctions between narcissistic and healthy entitlement, and within the context of the three‐dimensional model of entitlement.
Social Capital and Pastoral Institutions in Conflict Management: Evidence from Eastern Ethiopia
Authors: Mohammed Ahmed , Beyene Fekadu
Published: January 2015

This paper examines the role of customary pastoral institutions in managing conflicts. It indicates thatintra‐ethnic conflicts can be managed customarily because of shared norms attributed to the social proximity and cultural homogeneity, whereas managing inter‐ethnic conflicts goes beyond the capacity of elders' council exercising customary law. The introduction of ethnic‐based federalism and historical political relations between different ethnic groups has weakened customary institutions in managing inter‐ethnic conflict. Using elders as community representatives in the formal system has negatively affected them because of community mistrust where they believe that ‘state elders’ are loyal to the state than to the community. Copyright © 2015 John Wiley & Sons, Ltd.
The prelimbic cortex muscarinic M3 receptor–nitric oxide–guanylyl cyclase pathway modulates cardiovascular responses in rats
Authors: Fassini Aline , Antero Leandro S. , Corrêa Fernando M.A. , Joca Sâmia R. , Resstel Leonardo B.M.
Published: January 2015

The prelimbic cortex (PL), a limbic structure, sends projections to areas involved in the control of cardiovascular responses. Stimulation of the PL with acetylcholine (ACh) evokes depressor and tachycardiac responses mediated by local PL muscarinic receptors. Early studies demonstrated that stimulation of muscarinic receptors induced nitric oxide (NO) synthesis and cyclic guanosine cyclic monophosphate (cGMP) formation. Hence, this study investigates which PL muscarinic receptor subtype is involved in the cardiovascular response induced by ACh and tests the hypothesis that cardiovascular responses caused by muscarinic receptor stimulation in the PL are mediated by local NO and cGMP formation. PL pretreatment with J104129 (an M3 receptor antagonist) blocked the depressor and tachycardiac response evoked by injection of ACh into the PL. Pretreatment with either pirenzepine (an M1 receptor antagonist) or AF‐DX 116 (an M2 and M4 receptor antagonist) did not affect cardiovascular responses evoked by ACh. Moreover, similarly to the antagonism of PL M3 receptors, pretreatment with Nω‐propyl‐L‐arginine (an inhibitor of neuronal NO synthase), carboxy‐PTIO(S)‐3‐carboxy‐4‐hydroxyphenylglicine (an NO scavenger), or 1H‐[1,2,4]oxadiazolol‐[4,3‐a]quinoxalin‐1‐one (a guanylate cyclase inhibitor) blocked both the depressor and the tachycardiac response evoked by ACh. The current results demonstrate that cardiovascular responses evoked by microinjection of ACh into the PL are mediated by local activation of the M3 receptor–NO–guanylate cyclase pathway. © 2015 Wiley Periodicals, Inc.
Calibration of Raman shifts of cyclohexane for quantitative analyses of methane density in natural and synthetic fluid inclusions
Authors: Chou I‐Ming
Published: January 2015

Raman shifts of cyclohexane were calibrated at room temperature based on two Ne emission lines near the ν1 peak of CH4 around 2918 cm−1. These calibrated Raman shifts of cyclohexane can be used as reference standards for obtaining accurate methane ν1 peak positions and, therefore, the pressures (or densities) of CH4 in natural or synthetic fluid inclusions. Copyright © 2015 John Wiley & Sons, Ltd.
Application of self‐organising maps towards segmentation of soybean samples by determination of inorganic compounds content
Authors: Cremasco Hágata , Borsato Dionísio , Angilelli Karina Gomes , Galão Olívio Fernandes , Bona Evandro , Valle Marcos Eduardo
Published: January 2015

BACKGROUND

In this study, 20 samples of soybean, both transgenic and conventional cultivars, which were planted in two different regions, Londrina and Ponta Grossa, both located at Paraná, Brazil, were analysed. In order to verify whether the inorganic compound levels in soybeans varied with the region of planting, K, P, Ca, Mg, S, Zn, Mn, Fe, Cu and B contents were analysed by an artificial neural network self‐organising map.

RESULTS

It was observed that with a topology 10 × 10, 8000 epochs, initial learning rate of 0.1 and initial neighbourhood ratio of 4.5, the network was able to differentiate samples according to region of origin. Among all of the variables analysed by the artificial neural network, the elements Zn, Ca and Mn were those which most contributed to the classification of the samples.

CONCLUSION

The results indicated that samples planted in these two regions differ in their mineral content; however, conventional and transgenic samples grown in the same region show no difference in mineral contents in the grain. © 2015 Society of Chemical Industry
Influence of age on resection of colorectal liver metastases
Authors: Schmidt Thomas , Strowitzki Moritz J. , Reissfelder Christoph , Rahbari Nuh N. , Nienhueser Henrik , Bruckner Thomas , Rahäuser Christoph , Keppler Ulrich , Schneider Martin , Büchler Markus W. , Ulrich Alexis
Published: January 2015

Background and Objectives

Only limited data exist investigating the outcome of patients older than 75 years after resection of colorectal liver metastases (CLM). Therefore, the present study aims to evaluate clinical and oncological outcome of elderly patients.

Methods

A cohort of 405 patients was divided into three age‐groups: (1) <65 years; (2) 65–75 years; and (3) >75 years of age. Patients' data were prospectively collected and retrospectively analyzed. We performed survival analysis and added age‐correction. Univariate and multivariate analysis was performed to determine independent prognostic risk factors.

Results

The 5‐year survival rate of the >75 years age‐group was distinctly decreased, compared to the other age‐groups. After age‐correction, the 5‐year survival rates and the survival curves increased to the greatest extent in patients older than 75 years. The MSKCC score proved to be a sufficient independent prognostic factor in the total patient cohort, patients <65 years and patients 65–75 years. In patients older than 75 years, only localization of the primary tumors was a significant prognostic factor for overall survival.

Conclusions

Patients' age is no reason to deny surgical treatment of CLM. Prognostic factors, such as MSKCC score, are not sufficient predictors of survival in patients older than 75 years. J. Surg. Oncol. 2015 111:729–739. © 2015 Wiley Periodicals, Inc.
Prognostic value of lymph node density in high‐grade salivary gland cancers
Authors: Hong Hye Ran , Roh Jong‐Lyel , Cho Kyung‐Ja , Choi Seung‐Ho , Nam Soon Yuhl , Kim Sang Yoon
Published: January 2015

Background

To investigate the role of lymph node density (LND) as an independent prognostic factor in high‐grade salivary gland cancers.

Methods

All 87 patients with high‐grade salivary gland cancers underwent curative surgery combined with neck dissection and most of them received postoperative radiotherapy or chemoradiotherapy. LND was calculated as the ratio of positive lymph nodes to total lymph nodes harvested. Clinicopathologic variables associated with cancer‐specific survival (CSS) and overall survival (OS) were identified by univariate and multivariate analyses using the Cox‐proportional hazards model.

Results

Salivary duct carcinoma was the most common tumor (54%), followed by carcinoma ex pleomorphic adenoma (22%), and others. The 5‐year CSS and OS were 50.9% and 49.6%, respectively, during a median follow‐up of 61 months. In univariate analysis, tumor site, pathologic nodal stage, overall tumor‐node‐metastasis (TNM) stage, primary tumor size >3 cm, lymphovascular invasion, perineural invasion, extranodal extension, number of metastatic lymph nodes, and LND >4.0 were significant prognostic factors for CSS and OS (P < 0.05 each). Tumor site, perineural invasion, and LND were independent prognostic factors for both CSS and OS in multivariate analysis (P < 0.01).

Conclusion

Our findings support the prognostic value of LND for high‐grade salivary gland cancers. J. Surg. Oncol. 2015 111:784–789. © 2015 Wiley Periodicals, Inc.
Cucurbit(6)uril immobilized on silica: A novel high‐performance liquid chromatographic stationary phase
Authors: Ma Liyun , Liu Simin , Wang Qing , Yao Lin , Xu Li
Published: January 2015

In the present study, one of the new generation of host molecules, cucurbit(6)uril (CB(6)), was immobilized onto silica (CB(6)/SiO2) by a sol–gel approach. CB(6)/SiO2was characterized by NMR spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis. It was used as a high‐performance liquid chromatographic stationary phase and its chromatographic performance was systematically investigated with different types of analytes as probes. The results revealed that the CB(6)/SiO2stationary phase exhibited weak hydrophobic and strong hydrophilic properties. Hence, the variables for hydrophilic interaction liquid chromatography, including components and pH of the mobile phase, were further investigated to explore the retention mechanism of this CB(6)/SiO2stationary phase. For less polar analytes, both hydrophobic and hydrophilic interactions could contribute to the retention, while for polar analytes, hydrophilic interaction may be predominant. Compared to the tetraethoxylsilane‐coated SiO2stationary phases, the CB(6)/SiO2stationary phase exhibited a different retention behavior toward basic analytes with excellent stability. It is a novel promising hydrophilic interaction liquid chromatography stationary phase.
Synthesis of metronidazole‐imprinted molecularly imprinted polymers by distillation precipitation polymerization and their use as a solid‐phase adsorbent and chromatographic filler
Authors: Liu Jiang , Zhang Lu , Li Han Song Le , Liu Yuan , Tang Hui , Li Yingchun
Published: January 2015

Metronidazole‐imprinted polymers with superior recognition properties were prepared by a novel strategy called distillation–precipitation polymerization. The as‐obtained polymers were characterized by Fourier‐transform infrared spectroscopy, laser particle size determination and scanning electron microscopy, and their binding performances were evaluated in detail by static, kinetic and dynamic rebinding tests, and Scatchard analysis. The results showed that when the fraction of the monomers was 5 vol% in the whole reaction system, the prepared polymers afforded good morphology, monodispersity, and high adsorption capacity and excellent selectivity to the target molecule, metronidazole. The optimal binding performance is 12.41 mg/g for metronidazole just before leakage occurred and 38.51 mg/g at saturation in dynamic rebinding tests. Metronidazole‐imprinted polymers were further applied as packing agents in solid‐phase extraction and as chromatographic filler, both of which served for the detection of metronidazole in fish tissue. The results illustrated the recoveries of spiked samples ranged from 82.97 to 87.83% by using molecularly imprinted solid‐phase extraction combined with a C18 commercial column and 93.7 to 101.2% by directly using the polymer‐packed chromatographic column. The relative standard deviation of both methods was less than 6%.
Determination of fat‐soluble vitamins in vegetable oils through microwave‐assisted high‐performance liquid chromatography
Authors: Carballo Silvia , Prats Soledad , Maestre Salvador , Todolí José‐Luis
Published: January 2015

In this manuscript, a study of the effect of microwave radiation on the high‐performance liquid chromatography separation of tocopherols and vitamin K1 was conducted. The novelty of the application was the use of a relatively low polarity mobile phase in which the dielectric heating effect was minimized to evaluate the nonthermal effect of the microwave radiation over the separation process. Results obtained show that microwave‐assisted high‐performance liquid chromatography had a shorter analysis time from 31.5 to 13.3 min when the lowest microwave power was used. Moreover, narrower peaks were obtained; hence the separation was more efficient maintaining or even increasing the resolution between the peaks. This result confirms that the increase in mobile phase temperature is not the only variable for improving the separation process but also other nonthermal processes must intervene. Fluorescence detection demonstrated better signal‐to‐noise compared to photodiode arrayed detection mainly due to the independent effect of microwave pulses on the baseline noise, but photodiode array detection was finally chosen as it allowed a simultaneous detection of nonfluorescent compounds. Finally, a determination of the content of the vitamin E homologs was carried out in different vegetable oils. Results were coherent with those found in the literature.
Kinetic Study of Di‐Tert‐Butyl Peroxide: Thermal Decomposition and Product Reaction Pathways
Authors: Sebbar Nadia , Bozzelli Joseph W. , Bockhorn Henning
Published: January 2015

The major reaction path for oxidation of di‐tert‐butyl peroxide (DTBP) is generally considered to occur via fission of the weak peroxide ROOR bond at temperatures above 393 K. The initial stable intermediates in the thermal decomposition or combustion of DTBP are acetone and ethane, and the overall reaction is accompanied by an important heat release which when mixed with air (oxygen) may exceed the self‐ignition temperatures. A kinetic study on plausible DTBP reaction paths was initiated in this work, and a detailed study of the thermochemistry of new intermediates, transition state structures, and products is reported. The density functional theory (DFT; B3LYP/6‐311g(d,p)), which is practical for large compounds along with the composite ab initio G3MP2B3 and G3 calculations, (when possible), are used. Computational chemistry results from DFT and ab initio calculations are coupled with isodesmic reaction analysis which, as demonstrated in previous studies, results in good accuracy. Over 10 unimolecular decomposition pathways are identified and reported.
Reactivity of Dinuclear Copper(II) Complexes with N‐Salicylidene Glycine Schiff Bases as Carboxylesterase Models
Authors: Xu Bin , Jiang Weidong , Liu Fuan , Yu Yongde , Dong Juan
Published: January 2015

Two phenoxo‐bridged dinuclear copper(II) complexes (Cu2L12, Cu2L22) with N‐salicylidene glycine Schiff bases were prepared and evaluated their performance for catalyzing the hydrolysis of p‐nitrophenyl picolinate (PNPP). The observations reveal that the as‐prepared dinuclear copper(II) complexes exhibited better activity by two to three orders of magnitude rate enhancement in comparison with the autohydrolysis rate of PNPP. Chloro‐containing Cu2L22 aroused approximately three times kinetic advantage over chloro‐free Cu2L12 at pH 7.0, which is probably contributed to the electron‐withdrawing inductive effect of the 5′‐chloride group. Moreover, it was found that the pH‐responded kinetic behavior displayed an enzyme‐like property for the PNPP hydrolysis by the two complexes.
Runoff and Inter‐Rill Erosion Affected by Wildfire and Pre‐Fire Ploughing in Eucalypt Plantations of North‐Central Portugal
Authors: Malvar Maruxa C. , Prats Sergio A. , Keizer J. Jacob
Published: January 2015

Increases in post‐fire runoff and erosion have been reported worldwide, but little is known about the combined effect of wildfires and pre‐existent ploughing operations. A previous study using simulated rainfall found a similar runoff for an unploughed and a pre‐fire ploughed site, but clearly showed lower erosion for the pre‐fire ploughed site. This study measured post‐fire runoff and erosion at the same two sites, with the same experimental design, but under natural rainfall conditions. Four micro‐plots were installed on each of two eucalypt stands, one of which was rip‐ploughed 20 years before the fire. The rainfall amount was 35% lower during the first post‐fire year than during the second, but the runoff coefficient was approximately 20% for both years and sites. The sediment losses were significantly higher on the unploughed than on the pre‐fire ploughed site during the first year (378 vs. 112 g m−2 y−1) and especially during the second year (552 vs. 67 g m−2 y−1). Half of the eroded sediments consisted of organic matter. On the unploughed site, both the natural and the extreme‐intensity simulated rainfall produced specific sediment losses of 0·35 gm−2 mm−1 rain, whereas the high‐intensity simulated rainfall produced approximately half (0·16 g m−2 mm−1 rain). At the pre‐fire ploughed site, the natural, high, and extreme‐intensity simulated rainfall produced similarly low‐specific sediment losses (0·07 g m−2 mm−1 rain). These low rates and the absence of differences between methodologies and simulated intensities suggested a depletion of soil stocks 20 years after the rip‐ploughing. Copyright © 2015 John Wiley & Sons, Ltd.
Migration of di‐(2‐ethylhexyl)adipate (DEHA) and acetyl tributyl citrate (ATBC) plasticizers from PVC film into the food stimulant of isooctane
Authors: Lajqi‐Makolli V. , Kerolli‐Mustafa M. , Malollari I. , Lajqi J.
Published: January 2015

Chemical migration from food packing is influenced by several factors such as nature of chemicals, complexity of food, temperature, packing material used and properties of the migrating substances. Chemical compounds that are incorporated within polymeric packaging materials may interact with food components during processing or storage and migrate into the food by jeopardizing the food safety. This migration is higher if food remains in contact with packing material for extended time. Polyvinyl chloride (PVC) film such as di‐(2‐ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC) are still widely used as a food packing material due to its flexibility, transparency and low water permeability. The present study covers the main migration phenomena of both plasticizers (di‐(2‐ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC)) from PVC‐film into isooctane food stimulant using a direct gas chromatographic method. An exposure period of 48 h at 30 °C and 4 °C was used. The obtained results showed DEHA levels ranging of 7.2 mg/dm2 while, no ATBC migration from PVC‐film was observed. Results are discussed in relation to EU legislation proposed upper limit for DEHA specific migration (18 mg/L or 3 mg/dm2) and overall migration limit (OM) of 10 mg/dm2.
Combined vacuum plasma surface treatment for increase of durability of face milling cutters from high‐speed steel
Authors: Grigoriev S. , Volosova M. , Melnik Y. , Cherkasova N.
Published: January 2015

The article deals with the influence of the vacuum plasma surface treatment on the life of the face milling cutter of high‐speed steel R6M5 (analog M2 (USA, AISI/ASTM)). Such processing combines ion nitriding in gas plasma and the deposition of the wear‐resistant TiAlN layer in the metal gas plasma of the vacuum‐arc discharge. Research verifies that the use of vacuum plasma treatment combining the formation of the transition nitrided layer in the gas plasma and the subsequent deposition of TiAlN coating in metal gas plasma created by a vacuum‐arc discharge is an effective way to improve the tool life of high‐speed steel face milling cutters.
Management of composition cathodic products in the electrolysis of molybdenum‐, tungsten‐ and carbon‐ bearing halogenide‐oxide and oxide melts
Authors: Malyshev V. V. , Soloviev V. V. , Chernenko L. A. , Rozhko V. N.
Published: January 2015

It is shown that the cathode products of electrolysis of melts based on a eutectic mixture of sodium chloride and lithium fluoride as well as melts based on sodium tungstate in which dissolved oxides of molybdenum (VI) or tungsten (VI), molybdate, tungstate and lithium or sodium carbonates are molybdenum, tungsten, their bronzes and carbides, carbon.

It is established that the phase composition of electrolysis products is determined by the concentration of carbonate in the melt.

Particular conditions of plating coating of molybdenum and tungsten carbides on carbon, nickel and copper materials are determined.

Molybdenum carbide coatings of electrolyte Na2WO4–Li2MoO4–Li2CO3 are deposited at equality (within 2.5 mol%) of concentrations molybdate and lithium carbonate. However, their concentrations should not exceed 10 mol%. At lower concentrations of molybdate in the precipitate are detected carbon, molybdenum, molybdenum carbide, and at high concentrations – molybdenum oxides. At lower concentrations of carbonate in the sediment dominates molybdenum and at large concentrations mainly free carbon is released. More affordable industrial reagent‐source of molybdenum is its oxide.
Influence of nitriding on corrosion resistance of martensitic X17CrNi16‐2 stainless steel
Authors: Cajner F. , Kovačić S. , Rafael H. , Vugrinčić A. , Šimunović V. , Gržeta B.
Published: January 2015

Nitriding increases surface hardness and improves wear resistance of stainless steels. However, nitriding can sometimes reduce their corrosion resistance. In this paper, the influence of nitriding on the corrosion resistance of martensitic stainless steel was investigated. Plasma nitriding at 440 °C and 525 °C and salt bath nitrocarburizing were carried out on X17CrNi16‐2 stainless steel. Microhardness profiles of the obtained nitrided layers were examined. Phase composition analysis and quantitative depth profile analysis of the nitrided layers were preformed by X‐ray diffraction (XRD) and glow‐discharge optical emission spectrometry (GD‐OES), respectively. Corrosion behaviour was evaluated by immersion test in 1% HCl, salt spray test in 5% NaCl and electrochemical corrosion tests in 3.5% NaCl aqueous solution. Results show that salt bath nitrocarburizing, as well as plasma nitriding at low temperature, increased microhardness without significantly reducing corrosion resistance. Plasma nitriding at a higher temperature increased the corrosion tendency of the X17CrNi16‐2 steel.
Targeting cannabinoid receptor‐2 pathway by phenylacetylamide suppresses the proliferation of human myeloma cells through mitotic dysregulation and cytoskeleton disruption
Authors: Feng Rentian , Tong Qin , Xie Zhaojun , Cheng Haizi , Wang Lirong , Lentzsch Suzanne , Roodman G.David , Xie Xiang‐Qun
Published: January 2015

Cannabinoid receptor‐2 (CB2) is expressed dominantly in the immune system, especially on plasma cells. Cannabinergic ligands with CB2 selectivity emerge as a class of promising agents to treat CB2‐expressing malignancies without psychotropic concerns. In this study, we found that CB2 but not CB1 was highly expressed in human multiple myeloma (MM) and primary CD138+ cells. A novel inverse agonist of CB2, phenylacetylamide but not CB1 inverse agonist SR141716, inhibited the proliferation of human MM cells (IC50: 0.62∼2.5 μM) mediated by apoptosis induction, but exhibited minor cytotoxic effects on human normal mononuclear cells. CB2 gene silencing or pharmacological antagonism markedly attenuated phenylacetylamide's anti‐MM effects. Phenylacetylamide triggered the expression of C/EBP homologous protein at the early treatment stage, followed by death receptor‐5 upregulation, caspase activation, and β‐actin/tubulin degradation. Cell cycle related protein cdc25C and mitotic regulator Aurora A kinase were inactivated by phenylacetylamide treatment, leading to an increase in the ratio inactive/active cdc2 kinase. As a result, phosphorylation of CDK substrates was decreased, and the MM cell mitotic division was largely blocked by treatment. Importantly, phenylacetylamide could overcome the chemoresistance of MM cells against dexamethasone or melphalan. Thus, targeting CB2 may represent an attractive approach to treat cancers of immune origin. © 2015 Wiley Periodicals, Inc.
Melatonin modulated autophagy and Nrf2 signaling pathways in mice with colitis‐associated colon carcinogenesis
Authors: Trivedi P.P. , Jena G.B. , Tikoo﻿ K.B. , Kumar V.
Published: January 2015

Colon carcinogenesis is long known to be associated with ulcerative colitis (UC), a chronic gastrointestinal disorder. Various pre‐clinical and clinical studies have shown that melatonin (MEL) has beneficial effects in cancer. However, elucidation of the detailed molecular mechanisms involved in MEL‐mediated protection against the colon carcinogenesis deserves further investigation. The present study was aimed at deciphering the effect of MEL on autophagy and Nrf2 signaling pathways in a mouse model of colitis‐associated colon carcinogenesis (CACC). For the induction of CACC, male Swiss Albino mice were administered a single ip injection of 20 mg 1, 2‐dimethylhydrazine dihydrochloride (DMH)/kg bw, followed by 3 cycles of 3% w/v dextran sulfate sodium (DSS) in drinking water treatment initiated 1 wk after DMH injection. One week after the initiation of DSS treatment, MEL was administered at the dose of 1 mg/kg, bw, po for 8 and 18 wk. Mice were sacrificed at 10 and 20 wk after DMH injection. MEL treatment decreased the progression of CACC by down regulating the process of autophagy as revealed by the expression pattern of various autophagy markers such as Beclin‐1, LC3B‐II/LC3B‐I ratio and p62. These findings were accompanied with the increased expression of Nrf2 and the associated antioxidant enzymes, NAD(P)H:quinone oxidoreductase (NQO‐1) and heme oxygenase‐1 (HO‐1) in the colon of mice with CACC. MEL intervention reduced autophagy by ameliorating inflammation and oxidative stress in the colon of mice with CACC. We conclude that MEL treatment attenuates the progression of CACC in mice by modulating autophagy and Nrf2 signaling pathways. © 2015 Wiley Periodicals, Inc.
Microstructural changes in white matter associated with freezing of gait in Parkinson's disease
Authors: Vercruysse Sarah , Leunissen Inge , Vervoort Griet , Vandenberghe Wim , Swinnen Stephan , Nieuwboer Alice
Published: January 2015

In Parkinson's disease (PD), freezing of gait (FOG) is associated with widespread functional and structural gray matter changes throughout the brain. Previous study of freezing‐related white matter changes was restricted to brainstem and cerebellar locomotor tracts. This study was undertaken to determine the spatial distribution of white matter damage associated with FOG by combining whole brain and striatofrontal seed‐based diffusion tensor imaging. Diffusion‐weighted images were collected in 26 PD patients and 16 age‐matched controls. Parkinson's disease groups with (n = 11) and without freezing of gait (n = 15) were matched for age and disease severity. We applied tract‐based spatial statistics to compare fractional anisotropy and mean diffusivity of white matter structure across the whole brain between groups. Probabilistic tractography was used to evaluate fractional anisotropy and mean diffusivity of key subcortico‐cortical tracts. Tract‐based spatial statistics revealed decreased fractional anisotropy in PD with FOG in bilateral cerebellar and superior longitudinal fascicle clusters. Increased mean diffusivity values were apparent in the right internal capsule, superior frontal cortex, anterior corona radiata, the left anterior thalamic radiation, and cerebellum. Tractography showed consistent white matter alterations in striatofrontal tracts through the putamen, caudate, pallidum, subthalamic nucleus, and in connections of the cerebellar peduncle with subthalamic nucleus and pedunculopontine nucleus bilaterally. We conclude that FOG is associated with diffuse white matter damage involving major cortico‐cortical, corticofugal motor, and several striatofrontal tracts in addition to previously described cerebello‐pontine connectivity changes. These distributed white matter abnormalities may contribute to the motor and non‐motor correlates of FOG. © 2015 International Parkinson and Movement Disorder Society
Freezing of gait in Parkinson's disease is related to impaired motor switching during stepping
Authors: Smulders Katrijn , Esselink Rianne A. , Bloem Bastiaan R. , Cools Roshan
Published: January 2015

Background

Parkinson's disease (PD) has been associated with set switching difficulty in both the motor and the cognitive domain. However, the contribution of these set switching deficits to the primary motor symptoms of the disease is unclear. We investigated whether set switching deficits contribute to gait and stepping problems in PD. By contrasting motor and cognitive set switching within the same paradigm, we investigated the nature of set switching deficits associated with freezing of gait (FOG).

Methods

We integrated step initiation with set switching within one task and compared patients with and without FOG with healthy subjects. Motor set switching was defined as a change in stepping direction from one trial to the next. Cognitive set switching was defined as a change in task rule (ie, respond according to the shape or color of the presented stimulus).

Results

We found delayed motor switching in PD patients with FOG. We did not observe impaired cognitive switching.

Conclusions

These findings suggest that motor set switching deficits, commonly reported in tasks using verbal or tapping responses, extend to stepping and can contribute to the occurrence of freezing episodes during gait initiation. © 2015 International Parkinson and Movement Disorder Society
Dynamical behavior for a class of predator–prey system with general functional response and discontinuous harvesting policy
Authors: Cai Zuowei , Huang Lihong , Zhang Lingling , Hu Xiaolian
Published: January 2015

In this paper, we introduce a class of predator–prey system with general functional response, whose harvesting policy is modeled by a discontinuous function. Based on the differential inclusions theory, topological degree theory in set‐valued analysis and generalized Lyapunov approach, we analyze the existence, uniqueness and global asymptotic stability of positive periodic solution. In particular, a series of useful criteria on existence, uniqueness and global asymptotic stability of the positive equilibrium point are established for the autonomous system corresponding to the non‐autonomous biological and mathematical model with a discontinuous right‐hand side. Moreover, some new sufficient conditions are provided to guarantee the global convergence in measure of harvesting solution and convergence in finite time of any positive solution for the autonomous discontinuous biological system. The obtained results, which improve and generalize previous works on dynamical behavior in the literature, are of interest for understanding and designing biological system with not only continuous or even Lipschitz continuous but also discontinuous harvesting function. Finally, we give three examples with numerical simulations to show the applicability and effectiveness of our main results. Copyright © 2015 John Wiley & Sons, Ltd.