bluuebunny/crossref_metadata_2025_split huggingface dataset:
Steady‐State Multiplicity in High‐Pressure Bubble Column Reactors
Authors: Shaikh A. A. , Binous H. 
Published: April 2013

AbstractThe effect of pressure on the possible existence of multiple steady states in bubble column reactors is investigated. A mathematical model involving fast pseudo first‐order kinetics is employed to describe the performance of non‐isobaric, non‐isothermal reactors. The numerical analysis reveals that the existence of multiplicity is sensitive to pressure variation, yet high‐pressure operating conditions do not necessarily lead to a higher likelihood of multiplicity in these contactors.
Numerical Study of the Solid Volume Fraction and Pressure Drop of Fibrous Media by Response Surface Methodology
Authors: Zhu X. , Qian F. , Lu J. , Zhang H. 
Published: April 2013

AbstractIn order to establish a realistic fibrous media structure, internal microscopic cross‐sectional images were taken by scanning electron microscopy and then processed by Matlab. Finally, the 3D models of the fibrous media were reconstructed using Gambit software. The influences of structural parameters of the fibrous media on solid volume fraction and pressure drop were analyzed by response surface methodology, and the internal gas flow fields of the fibrous media were simulated using Ansys Fluent. The simulation results of the pressure drop are in good agreement with the Davies experimental correlation data.
Methane Hydrate Formation and Dissociation in the presence of Bentonite Clay Suspension
Authors: Kumar Saw V. , Udayabhanu G. N. , Mandal A. , Laik S. 
Published: April 2013

AbstractThe present work reports the effect of bentonite clay on methane hydrate formation and dissociation in synthetic seawater of salinity 3.55 % of total dissolved salts. Extensive observations of pressure‐temperature equilibrium during formation and decomposition of methane hydrate under different conditions have been made. It is observed that phase equilibrium conditions of hydrate are affected on changing the concentration of bentonite clay in synthetic seawater. Induction time for hydrate nucleation has been measured under different concentrations of clay and subcooling conditions. The presence of bentonite clay in synthetic seawater reduces the induction time of hydrate formation. Enthalpy of hydrate dissociation is calculated by Clausius‐Clapeyron equation using measured phase equilibrium data. The amount of gas consumed during hydrate formation has been calculated using real gas equation. It is found that a larger amount of gas is consumed upon addition of bentonite clay in synthetic seawater.
Metathesis of Ethene and Decene to Propene over a WO3/SiO2 Catalyst
Authors: Chen S.‐L. , Wang Y. , Yuan G. , Hua D. , Zheng M. , Zhang J. 
Published: April 2013

AbstractMetathesis between decene and ethene to propene over a WO3/SiO2 catalyst was studied. The dependency of the conversion of decene, selectivity to propene, and working lifetime of the catalyst on ethane‐to‐decene molar ratio and temperature was evaluated. Low temperature was found to be favorable to the production of C6–C9 olefins, while high temperature enhanced C10+ olefins. The working lifetime of the catalyst decreased with the weight hourly space velocity. The optimum reaction conditions for the metathesis process of decene and ethene to propene were determined. An obvious induction period was found to exist in the metathesis reaction.
Safety and efficacy of adjuvant pegylated interferon therapy for metastatic tumor antigen 1‐positive hepatocellular carcinoma
Authors: Lee Danbi , Chung Young‐Hwa , Kim Jeong A. , Park Won Hyung , Jin Young‐Joo , Shim Ju Hyun , Ryu Soo Hyung , Jang Myoung Kuk , Yu, Eunsil , Lee Young Joo 
Published: April 2013

BACKGROUNDMetastatic tumor antigen 1 (MTA1) overexpression is closely associated with postoperative recurrence of hepatocellular carcinoma (HCC). It has been suggested that pegylated interferon (Peg‐IFN) can prevent the occurrence of HCC in patients who have chronic viral hepatitis. In this study, the authors examined whether postoperative adjuvant Peg‐IFN therapy can reduce the recurrence of MTA1‐positive HCC after curative surgical resection.METHODSIn this case‐control study, 93 patients with MTA1‐positive HCC who underwent curative surgical resection were prospectively enrolled. The median patient age was 53 years (range, 27‐78); there were 65 men and 28 women; the etiology was hepatitis B virus (HBV) in 77 patients, hepatitis C virus (HCV) in 6 patients, and non‐HBV/non‐HCV in 10 patients; 31 patients received Peg‐IFN (Peg‐INTRON®) subcutaneously at a dose of 50 μg per week for 12 months (the Peg‐IFN group); and the remaining 62 patients were followed only and did not receive any adjuvant therapies (control group). Patients were followed every 1 to 3 months for a median of 24 months.RESULTSHCC recurred postoperatively in 26 of 93 patients (28%), and 9 patients (10%) died during follow‐up. The overall cumulative recurrence rates were significantly lower in the Peg‐IFN group than in the control group (7% and 14% vs 24% and 34% at 1 year and 2 years, respectively; P < .05). In addition, the 1‐year and 2‐year cumulative survival rates were higher in the Peg‐IFN group compared with the control group (100% vs 93% and 100% vs 87%, respectively; P < .05). In multivariate analysis, the receipt of adjuvant Peg‐IFN therapy, in addition to having a lower Cancer of the Liver Italian Program score and being a woman, was an independent, favorable factor for a lower risk of postoperative recurrence.CONCLUSIONSThe current data indicate that adjuvant Peg‐IFN therapy may reduce the recurrence of HCC in patients who have MTA1‐positive HCC after curative surgical resection. Cancer 2013;119:2239–2246. © 2013 American Cancer Society.
Proton‐Coupled Self‐Assembly of a Porphyrin‐Naphthalenediimide Dyad
Authors: Tu Siyu , Kim Se Hye , Joseph Jojo , Modarelli David A. , Parquette Jon R. 
Published: April 2013

AbstractThe construction of an n–p heterojunction through the self‐assembly of a dyad based on tetraphenylporphyrin (TPP) and 1,4,5,8‐naphthalenedimide (NDI) (1) is described. Proton transfer from the lysine head group of 1 to the porphyrin ring occurs concomitantly with self‐assembly into 1D nanorods in CHCl3. TEM and AFM studies showed that the nanorods are formed by the lateral and vertical fusion of multilameller vesicles into networks and hollow ribbons, respectively. These intermediate structures transitioned to nanorods over the course of 4–6 days. Time‐resolved spectroscopy revealed that photoinduced charge separation occurs with rate constants that depend on the nature of the aggregation.
Postsynthetic Modification of a Metal–Organic Framework (MOF) Structure for Enantioselective Catalytic Epoxidation
Authors: Candu Natalia , Tudorache Mădălina , Florea Mihaela , Ilyes Elena , Vasiliu Florin , Mercioniu Ionel , Coman Simona M. , Haiduc Ionel , Andruh Marius , Pârvulescu Vasile I. 
Published: April 2013

AbstractPostsynthetic modification of [Cu2(mand)2(hmt)] (mand=mandelic acid, hmt=hexamethylenetetramine) with a chiral, dimeric chromium(III)–salen complex led to a robust structure. Characterization of this new material showed that it perfectly preserved the textural and structural properties of the parent metal–organic framework (MOF). Although epoxidation of trans‐methyl cinnamate with hydrogen peroxide led to copper leaching of 2–3 %, experiments performed with N‐methylmorpholine‐N‐oxide indicated no leaching, even after 72 h of exposure. The obtained chiral MOF is an effective catalyst for the enantioselective epoxidation of trans‐methyl cinnamate and leads to (2R,3S)‐phenylglycidate with a high enantiomeric excess at room temperature.
Frequency acquisition synchronization for multiple antenna systems
Authors: Ma Chixiang , Lin Ping 
Published: April 2013

SUMMARYIn this paper, we consider the problem of frequency acquisition synchronization by using multiple antennas over wireless fading channels. We introduce frequency synchronization with different combining schemes including space diversity and time diversity. Their performance is estimated for a Rayleigh fading channel with an analysis both theoretically and by simulation. We investigate the relationship between the mean squared error (MSE) and the average signal‐to‐noise ratio (SNR) for combining of different blocks and antennas. Both the carrier frequency offset and the sampling frequency offset are estimated when multiple antennas are utilized for signal transmission. The estimation with maximum ratio combining (MRC) scheme is presented in detail, and the estimation with selection combining scheme and equal gain combining scheme are introduced briefly. The simulation results explicitly show that the performance of the frequency acquisition synchronization with MRC scheme is better than that of others and that the MSE at low SNR is not very close to the Cramér–Rao low bound in multiblock combining frequency synchronization. Furthermore, the results address that in order to improve the performance, the total number of receive antennas will be increased exponentially. Copyright © 2013 John Wiley & Sons, Ltd.
On the Reactivity of Silylboranes toward Lewis Bases: Heterolytic B–Si Cleavage vs. Adduct Formation
Authors: Kleeberg Christian , Borner Corinna 
Published: April 2013

AbstractSilylboranes are important reagents in a variety of catalytic silylation and silaboration reactions. While transition‐metal‐catalyzed reactions are well established, organo‐/Lewis base‐catalyzed reactions of silylboranes have only recently emerged. For both catalytic processes the reactivity of silylboranes toward Lewis bases is of relevance. While for organo‐catalyzed reactions Lewis base activation of the silylborane has been proposed, transition‐metal‐ and especially copper‐catalyzed reactions also frequently require the presence of Lewis basic alkali metal alkoxides. In the present study we explore the reaction of K(18‐crown‐6) tert‐butoxide and the NHC 1,3‐diisopropyl‐4,5‐dimethyl‐imidazol‐2‐ylidene as exemplary Lewis bases with the two silylboranes pinB‐SiMe2Ph and pinB‐SiPh3 (pin = OCMe2CMe2O). The reaction with K(18‐crown‐6) tert‐butoxide results in activation of the boron–silicon bond. The isolated product of this activation is either the potassium silyl complex [K(18‐crown‐6)SiPh3] or [K(18‐crown‐6)(thf)2][pinB(SiMe2Ph)2], the formal Lewis acid/base adduct of [K(18‐crown‐6)SiMe2Ph] with pinB‐SiMe2Ph. Both complexes react essentially as sources of nucleophilic silyl moieties in reactions with exemplary electrophiles. In contrast, usage of the carbene leads to the formation of isolable Lewis acid/base adducts of the type (NHC)pinB‐SiR3, which do not react as sources of nucleophilic silyl moieties. The identification and characterization of these species appears of relevance for the mechanistic understanding and further development of Lewis base/organo‐ as well as transition‐metal‐catalyzed silyl transfer reactions.
Total Syntheses of Eudistomins Y1–Y7 by an Efficient One‐Pot Process of Tandem Benzylic Oxidation and Aromatization of 1‐Benzyl‐3,4‐dihydro‐β‐Carbolines
Authors: Trieu Tien Ha , Dong Jing , Zhang Qiang , Zheng Bo , Meng Tian‐Zhuo , Lu Xia , Shi Xiao‐Xin 
Published: April 2013

AbstractThe first total synthesis of eudistomin Y7 (7) and total syntheses of eudistomins Y1–Y6 (1–6) are described. An efficient room‐temperature conversion of 1‐benzyl‐3,4‐dihydro‐β‐carbolines (11) into 1‐benzoyl‐β‐carbolines (14) by a one‐pot process of tandem benzylic oxidation and aromatization as the key step of these total syntheses was also studied in detail.
Gasification of Low‐Grade Coal in a Dual Fluidized‐Bed Steam Gasifier
Authors: Kern Stefan , Pfeifer Christoph , Hofbauer Hermann 
Published: April 2013

AbstractThe gasification of a bituminous coal was performed in a dual fluidized‐bed (DFB) steam gasifier at a fuel power of 90 kWth. The main aim of these tests was to prove the suitability of the DFB system for cheap low‐grade coals that are often delivered with a wide range of particle sizes and ash loads. The fine fraction in particular can become entrained in the gas stream and thus be responsible for changes in the system performance and gas quality. The selected gasifier bed material was olivine, with an applied particle size of 375 μm, the steam‐to‐carbon ratio was 1.3 kg kgC−1, and the gasification temperature was 850 °C. In addition to standard online analysis of the main components of the product gas, impurities that included NH3, H2S, and tar were also examined.
Change in antipsychotic usage pattern and risk of relapse in older patients with schizophrenia
Authors: Talaslahti Tiina , Alanen Hanna‐Mari , Hakko Helinä , Isohanni Matti , Häkkinen Unto , Leinonen Esa 
Published: April 2013

ObjectiveThe aim of this study was to explore the use of first (FGAs) and second generation antipsychotics (SGAs) in older outpatients with schizophrenia and schizoaffective disorder. Factors associated with schizophrenic relapses were also studied.MethodsThe study sample consisting of 8792 patients aged 64 years or more was collected from Finnish nationwide registers. The register data on the use of FGAs and SGAs were followed up between 1998 and 2003. Factors associated with psychiatric hospitalization in 1999 indicating relapse were studied using logistic regression analysis.ResultsThe use of SGAs increased from 2.8% to 12.4%, and the use of FGAs decreased from 57.5% to 39.4%. The use of a combination of SGAs and FGAs increased from 4.0% to 8.5%. The proportion of those who did not buy any antipsychotics varied between 35.8% and 39.7%. The number of patients hospitalized on psychiatric wards within a year (1999; relapsed) was 8.8%. Factors independently associated with relapse were use of combined FGAs and SGAs [odds ratio (OR) 1.70, p = 0.001] and use of antidepressants (OR 1.27, p = 0.019). Diagnosis of cardiovascular disease was negatively associated with risk of schizophrenic relapse (OR 0.84, p = 0.040).ConclusionThe use of SGAs increased while the use of FGAs decreased in older outpatients with schizophrenia. Almost 40% of the study sample did not use any antipsychotic medication. The 1‐year relapse rate was 8.8%. Several factors, such as combined use of FGAs and SGAs, or antidepressants, were associated with schizophrenic relapse, whereas cardiovascular disease showed a negative association with the relapse. Copyright © 2013 John Wiley & Sons, Ltd.
Polymorphisms influencing olanzapine metabolism and adverse effects in healthy subjects
Authors: Cabaleiro Teresa , López‐Rodríguez Rosario , Ochoa Dolores , Román Manuel , Novalbos Jesús , Abad‐Santos Francisco 
Published: April 2013

ObjectiveThe pharmacokinetics of olanzapine and response to treatment could be affected by polymorphisms in genes coding for drug‐metabolizing enzymes, transporters, or receptors. The aim of this study was to identify genetic markers predictive of pharmacokinetics, pharmacodynamics, and adverse effects of olanzapine.MethodsSixty‐three healthy volunteers receiving a single 5‐mg oral dose of olanzapine were genotyped for 39 genetic variants that could be related to the response to olanzapine. All genetic variants were analyzed by PharmaChip, but DRD2 Taq1A polymorphism was determined by real‐time polymerase chain reaction. Olanzapine was measured using high‐performance liquid chromatography combined with tandem mass spectrometry. The relationship of gender and polymorphisms with olanzapine pharmacokinetics, the change in prolactin levels, and the incidence of adverse effects were evaluated by multiple regression analysis.ResultsThe pharmacokinetics of olanzapine was influenced by polymorphisms in CYP3A5, GSTM3, and GRIN2B. Prolactin levels were affected by gender and polymorphisms in DRD2 and 5‐HTR2A. Polymorphisms in CYP2C9, TPMT, UGT1A1, MDR1, and 5‐HTR2A were related to some adverse effects of olanzapine.ConclusionsSeveral polymorphisms can explain differences in the pharmacokinetics, pharmacodynamics, and safety of olanzapine in healthy subjects. Whether these genetic factors influence the risk of therapeutic failure or tolerability in patients remains to be established. Copyright © 2013 John Wiley & Sons, Ltd.
Regulation of intracellular pH by glycosaminoglycans
Authors: Kathagen Nadine , Prehm Peter 
Published: April 2013

AbstractThe intracellular pH is regulated by a delicate balance of ion distribution across the plasma membrane and the physico‐chemical properties of intra‐ and extracellular components. We analyzed the effects of glycosaminoglycans on the intracellular pH of fibroblasts by using the fluorescent pH indicator BCECF‐AM. Addition of hyaluronan, hyaluronan oligosaccharides, chondroitin sulfate, or heparin to the culture medium of fibroblasts caused intracellular acidification from pH 7.2 to 6.7 in a concentration dependent manner. High molecular weight hyaluronan acidified more than hyaluronan oligosaccharides at the same concentrations. Hyaluronidase treatment or inhibition of hyaluronan export with xanthohumol led to intracellular alkalization. These observations indicated that extracellular glycosaminoglycans participate in intracellular pH regulation. The mechanism was explained by Donnan effects and molecular crowding. J. Cell. Physiol. 228: 2071–2075, 2013. © 2013 Wiley Periodicals, Inc.
Small GTPase Rap1 regulates cell migration through regulation of small GTPase RhoA activity in response to transforming growth factor‐β1
Authors: Moon Mi‐Young , Kim Hee‐Jun , Kim Jae‐Gyu , Lee Jae‐Yong , Kim Jaebong , Kim Sung‐Chan , Choi Ihn‐Geun , Kim Pyeung‐Hyeun , Park Jae‐Bong 
Published: April 2013

AbstractTransforming growth factor (TGF)‐β1 regulates diverse cellular functions. Particularly, TGF‐β1 induces monocyte migration to sites of injury or inflammation in early period, whereas TGF‐β1 inhibits cell migration in late phase. In this study, we attempted to understand how TGF‐β1 suppresses cell migration in late phase. We found that TGF‐β1 of short exposure induces the production of chemokines, such as macrophage inflammatory protein (MIP)‐1α, by Raw 264.7 cells. However, knock‐down of small GTPase RhoA by sh‐RhoA inhibited the production of MIP‐1α and macrophage migration, suggesting that RhoA is essential for expression of this chemokine. An activator of Epac (exchange proteins directly activated by cAMP; a guanine nucleotide exchange factor of Rap1), 8CPT‐2Me‐cAMP which leads to Rap1 activation abrogated MIP‐1α expression and macrophage migration. Indeed, GTP‐RhoA and GTP‐Rap1 levels were reciprocally regulated in a time‐dependent manner following TGF‐β1 stimulation. 8CPT‐2Me‐cAMP suppressed GTP‐RhoA levels, whereas si‐Rap1 augmented GTP‐RhoA levels and cell migration. TGF‐β1 produced cAMP in late period and si‐RNAs of Epac1 and Epac2 reduced GTP‐Rap1 levels leading to promotion of GTP‐RhoA levels. Furthermore, si‐RNA of ARAP3 (Rap‐dependent RhoGAP) increased GTP‐RhoA level and cell migration. Therefore, we propose the mechanism that prolonged TGF‐β1 treatment produce cAMP, which activates sequentially Epac, Rap1 and ARAP3, resulting in suppression of RhoA, chemokine expression, and macrophage migration. Contrary to the general concept that Rap1 stimulates cell migration, we demonstrated in this study that Rap1 inhibits cell migration by suppression of RhoA activity in response to TGF‐β1. J. Cell. Physiol. 228: 2119–2126, 2013. © 2013 Wiley Periodicals, Inc.
Effects of age and sex on the concentrations of glutamate and glutamine in the human brain
Authors: Hädel Sven , Wirth Christoph , Rapp Michael , Gallinat Jürgen , Schubert Florian 
Published: April 2013

PurposeTo determine the effects of age and sex on cerebral glutamate and glutamine concentrations in a large sample of healthy humans using a dedicated measuring and evaluation procedure. Exploratory examinations of other brain metabolites were also conducted.Materials and MethodsIn 118 healthy subjects aged 19 to 55 years (59 female) absolute concentrations of glutamate, glutamine, N‐acetylaspartate (NAA), total creatine, and total choline (tCho) in voxels comprising the left hippocampus (HC) and the anterior cingulate cortex (ACC) were investigated using point‐resolved spectroscopy with an echo time of 80 ms at 3 Tesla in combination with a reliable quantification procedure. Special care was taken to correct for multiple comparisons.ResultsAn age‐related decline of the concentrations of glutamate in both regions studied was observed whereas glutamine levels in ACC increased with age. Statistically significant sex‐related differences were detected for glutamate in the HC and for tCho in the ACC. NAA decreased with age in both regions, the significance not surviving Bonferroni correction.ConclusionThe results demonstrate effects of age and gender on glutamate, glutamine, choline containing compounds, and NAA in healthy human brain. They add to the growing evidence for gender‐specific differences in cerebral neurotransmission, metabolism, and structure across the lifespan. J. Magn. Reson. Imaging 2013;38:1480–1487. © 2013 Wiley Periodicals, Inc.
Geographic Information Systems in the Service of Alternative Tourism – Methods with Landscape Evaluation and Target Group Preference Weighting
Authors: Varjú Viktor , Suvák Andrea , Dombi Péter 
Published: April 2013

ABSTRACTThere is a large variety of types of rural areas and many of them are rich in landscape beauty. However, their preserved culture and traditions are revalued in today's rapid transformation of lifestyles. Alternative tourism is thus an emerging potential to economically support these areas, at the same time helps to preserve natural and cultural heritage.The methods provide sophisticated means to analyse the characteristics and the potential attractiveness of landscape and cultural attractions from the viewpoint of alternative tourism development. Homogenous tourism sub‐regions can be defined, and the most suitable development scenarios can be found to the certain areas. Copyright © 2013 John Wiley & Sons, Ltd.
Sex is not an independent risk factor for survival in differentiated thyroid cancer
Authors: Oyer Sam L. , Smith Valerie A. , Lentsch Eric J. 
Published: April 2013

Objectives/HypothesisTo determine the impact of sex on disease‐specific survival (DSS) in differentiated thyroid cancer.Study DesignRetrospective analysis of population database.MethodsAdult patients with papillary thyroid carcinoma (PTC) or follicular thyroid carcinoma (FTC) were identified from the Surveillance, Epidemiology, and End Results Database between 1988 and 2003. Patients were grouped according to tumor type (PTC or FTC), with age, sex, tumor size, extension, and nodal or distant metastases recorded. The Kaplan‐Meier method was used to compare DSS based on sex in each group.ResultsWe identified 36,725 patients, of which 77% were female and 23% were male. PTC represented 91.3% of patients and FTC the remaining 8.7%. Males with PTC and FTC were diagnosed at an older age and were significantly more likely to present with advanced‐stage disease. In patients ≥45 years old, DSS was similar in male and female patients; however, in patients <45 years old, DSS was significantly worse in males. When compared by stage, DSS was similar among male and female patients with stage II PTC; however, males with stage I PTC had a minimally reduced DSS. Stage‐stratified analysis revealed no DSS difference between male and female patients with FTC.ConclusionsMale sex does not portray an independent survival risk in differentiated thyroid cancer when survival is compared by disease stage. Men present at a later age with more advanced disease, which may explain their poorer survival seen in some studies.Level of Evidence4. Laryngoscope, 123:2913–2919, 2013