bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trace Analysis of Methyl Tert‐butyl Ether in Water Samples Using New Ultrasound‐assisted Dispersive Liquid‐liquid Microextraction and Gas Chromatography‐flame Ionization Detection
Authors: Rezaee Mohammad , Yamini Yadollah , Mashayekhi Hossein Ali , Naeeni Mohammad Hosein , Jubari Mostafa Bashiri 
Published: September 2011

AbstractIn this study, simple and efficient ultrasound‐assisted dispersive liquid‐liquid microextraction combined with gas chromatography (GC) was developed for the preconcentration and determination of methyl‐tert‐butyl ether (MTBE) in water samples. One hundred microliters of benzyl alcohol was injected slowly into 10 mL home‐designed centrifuge glass vial containing an aqueous sample with 30% (w/v) of NaCl that was located inside the ultrasonic water bath. The formed emulsion was centrifuged and 2 μL of separated benzyl alcohol was injected into a gas chromatographic system equipped with a flame ionization detector (GC‐FID) for analysis. Several factors influencing the extraction efficiency such as the nature and volume of organic solvent, extraction temperature, ionic strength and centrifugation times were investigated and optimized. Using optimum extraction conditions a detection limit of 0.05 μg L‐1 and a good linearity (r2 = 0.998) in a calibration range of 0.1‐500 μg L‐1 were achieved. This proposed method was successfully applied to the analysis of MTBE in tap, well and a ground water sam
ple contaminated by leaking gasoline from an underground storage tank (LUST) in a gasoline service station.
A Novel Improved Method to Increase the Efficiency of Dye‐Sensitized Solar Cells
Authors: Li Fei‐Tao , Wang Long‐Ge , Fu Shi‐Shu , Huo Zhuo‐Yu , Gu Yu‐Zong 
Published: September 2011

AbstractA novel improved method which employs a reflective mirror at the back of the Pt counter electrode is used in dye‐sensitized solar cells (DSSC). The direction of the light propagation in the cells was changed because of adding a mirror and the light reflected back into the DSSC in order to enhance the optical absorption of the DSSCs. Therefore, the performance of the cells was improved distinctively. The TiO2 electrodes were characterized by X‐ray diffraction, scanning electron microscopy and I‐V properties of the cells measured by Linear Sweep Voltammetry system. The results indicates that the conversion efficiency can be increased from 4.81% to 5.43% under AM 1.5 illumination when a mirror is added at the back of the Pt counter electrode in the same cell. Meanwhile, the Jsc, Voc and the fill factor can be obtained 18.65 mA/cm2, 0.728 V and 0.561, respectively.
Demonstration of inferior vena cava compression by probe pressure during subxiphoid echocardiography
Authors: Siegenthaler Nils , Giraud Raphael , Muller Hayo , Bendjelid Karim 
Published: September 2011

AbstractWe sought to compare the inferior vena cava diameter measured by transthoracic echocardiography and by transesophageal echocardiography in human and animals. Transthoracic echocardiography yielded lower inferior vena cava diameter values than transesophageal echocardiography. Adult and pediatric intensivists should pay attention to the risk of false measurement of the inferior vena cava anterior‐posterior diameter that may be due to compression of the inferior vena cava by the sonographic probe when the subxiphoid view is used. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
Sonographic diagnosis of choledochocele
Authors: Cakmakci Emin , Ugurlar Ozge Yapici , Erturk Sukru Mehmet , Ozel Alper , Basak Muzaffer 
Published: September 2011

AbstractWe present a case of a 48‐year‐old female with a history of cholecystectomy and recurrent attacks of pancreatitis whose initial abdominal sonography (US) revealed multiple conglomerated stones in the descending part of the duodenum. Abdominal CT, MRI, and magnetic resonance cholangiopancreatography showed the same findings. The distended sacciform distal intramural segment of the common bile duct was protruding into the duodenum. The imaging findings explained the etiology of the patient's recurrent attacks of pancreatitis and led to surgical excision of the choledococele. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound 40:448–450, 2012
Ontogenetic development of an exceptionally preserved Devonian cartilaginous skeleton
Authors: Johanson Zerina , Kearsley Anton , den Blaauwen Jan , Newman Michael , Smith Moya Meredith 
Published: September 2011

AbstractCartilaginous vertebrate skeletons leave few records as fossils, unless mineralized. Here, we report outstanding preservation of early stages of cartilage differentiation, present in the Devonian vertebratePalaeospondylus gunni. In large specimens ofPalaeospondylus, enlarged, hypertrophic cell spaces (lacunae) are dominant in the cartilage matrix, each defined by thin mineralized matrix, where phosphorus and calcium co‐occur. This is comparable to living endochondral cartilage, where cell hypertrophy and matrix mineralization mark the end of an ontogenetic process of cell growth and division before bone formation. New information from small individuals ofPalaeospondylusdemonstrates that the skeleton comprises mostly unmineralized organic matrix with fewer hypertrophic cell spaces, these occurring only in the central regions of each element. Only here has the surrounding matrix begun to mineralize, differing from the larger specimens in that phosphorus is dominant with little associated calcium at these earlier stages. This reflects cellular control of mineralization in living tissues through phosphate accumulation around hypertrophic cells, with later increase in calcium in the cartilaginous matrix. These features are always associated with endochondral bone development, but in thePalaeospondylusskeleton, this bone never develops. This skeletal state is thus far unique among vertebrates, with two alternative explanations: either later stages of endochondral bone development have been lost inPalaeospondylus, or, in a stepwise acquisition of the mineralized skeleton, these late stages have not yet evolved.J. Exp. Zool. (Mol. Dev. Evol.) 318:50–58, 2012. © 2011 Wiley Periodicals, Inc.
Precipitating events leading to voluntary employee turnover among information technology professionals
Authors: Von Hagel William J. , Miller Leslie A. 
Published: September 2011

AbstractVoluntary turnover rate of information technology (IT) professionals within defense contracting organizations has increased by 12.6% since 2003. The perceptions and lived experiences of IT professionals in the defense contracting industry were explored in a phenomenological study to better understand the precipitating events, or shocks, that led to their decision to voluntarily leave an organization. Twenty IT professionals at a small, service‐based, government contracting organization supporting the intelligence community in Ft. Meade, Maryland, were interviewed until data saturation was achieved. Analysis of interview responses revealed that managing relationships at multiple levels between employees, corporate management, and the direct supervisor or manager is one way that organizations can decrease their overall voluntary employee turnover. The results of the study can be used by business leaders to create innovative retention plans and enact positive organizational change to reduce the voluntary employee turnover of IT professionals.
Morphology of the embryonic and hatchling american alligator ductus arteriosi and implications for embryonic cardiovascular shunting
Authors: Jacobs Kimberley , Goy Sarah K. , Dzialowski Edward M. 
Published: September 2011

AbstractThe ductus arteriosi (DA) are embryonic blood vessels found in amniotic vertebrates that shunt blood away from the pulmonary artery and lungs and toward the aorta. Here, we examine changes in morphology of the right and left DA (LDA), and right and left aorta (LAo) from embryonic and hatchling alligators. The developing alligator has two‐patent DA that join the right and LAo. Both DA exhibit a muscular phenotype composed of an internal smooth muscle layer (2–4 cells thick). At hatching, the lumen diameter of both DA decreases as the vessels begin to close within the first 12 h of posthatch life. Between day 1 and day 12 posthatching, the vessel becomes fully occluded with endothelial and smooth muscle cells filling the lumen. A number of DA from hatchlings contained blood clots along their length. The lumen of the full term alligator DA is reduced in comparison with the full term chicken DA. The developing alligator embryo has an additional right‐to‐left shunt pathway in the LAo arising from the right ventricle. The embryonic LAo diameter is twice the diameter of either the right DA or LDA, providing a lower resistance pathway for blood leaving the right ventricle. On the basis of these findings, we propose that the paired DA of the embryonic alligator have a reduced role in the embryonic right‐to‐left shunt of blood from the right ventricle when compared with the avian DA. J. Morphol. 2011. © 2011 Wiley Periodicals, Inc.
Model‐based, semiquantitative and time intensity curve shape analysis of dynamic contrast‐enhanced MRI: A comparison in patients undergoing antiangiogenic treatment for recurrent glioma
Authors: Lavini Cristina , Verhoeff Joost J.C. , Majoie Charles B. , Stalpers Lukas J.A. , Richel Dick J. , Maas Mario 
Published: September 2011

AbstractPurpose:To compare time intensity curve (TIC)‐shape analysis of dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) data with model‐based analysis and semiquantitative analysis in patients with high‐grade glioma treated with the antiangiogenic drug bevacizumab.Materials and Methods:Fifteen patients had a pretreatment and at least one posttreatment DCE‐MRI. We applied a pixel‐by‐pixel TIC shape analysis, where TICs are classified into five different types according to their shape, and calculated the occurrence of each TIC type in the region of interest (ROI). The results were compared to the pharmacokinetic model (PKM) parameters Ktrans, Kep, Ve, and Vi, and with the semiquantitative parameters maximum enhancement (ME) and initial slope of increase (ISI).Results:The relative amount of type 2 and 4 TIC shape significantly correlated with the parameter Kep but not with Ktrans or Ve. The PKM parameter Ve and the semiquantitative parameters ME and ISI showed significant changes after treatment. None of the TIC shapes individually showed significant changes.Conclusion:The semiquantitative parameters ME and ISI are more sensitive to the effect of the bevacizumab than Ktrans and Ve. The pixel‐by‐pixel TIC shape analysis parameters are not sensitive to the effect of bevacizumab, although they can be seen as surrogates for the PKM parameter Kep. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
In vivo transport of Gd‐DTPA2− in human knee cartilage assessed by depth‐wise dGEMRIC analysis
Authors: Hawezi Zana K. , Lammentausta Eveliina , Svensson Jonas , Dahlberg Leif E. , Tiderius Carl J. 
Published: September 2011

AbstractPurpose:To investigate the transport of Gd‐DTPA2− in different layers of femoral knee cartilage in vivo.Materials and Methods:T1 measurements (1.5 Tesla) were performed in femoral knee cartilage of 23 healthy volunteers. The weight‐bearing central cartilage was analyzed before contrast and at eight time points after an intravenous injection of Gd‐DTPA2−: 12–60 min (4 volunteers) and 1–4 h (19 volunteers). Three regions of interest were segmented manually: deep, middle, and superficial.Results:Before contrast injection, a depth‐wise variation of T1 was observed with 50% higher values in the superficial region compared with the deep region. In the deep region, the uptake of Gd‐DTPA2− was not detected until 36 min and the concentration increased until 240 min, whereas in the superficial region, the uptake was seen already at 12 min and the concentration decreased after 180 min (P < 0.01). There was a difference between medial and lateral compartment regarding bulk, but not superficial Gd‐DTPA2− concentration. The bulk gadolinium concentration was negatively related to the cartilage thickness (r = −0.68; P < 0.01).Conclusion:The depth‐wise and thickness dependent variations in Gd‐DTPA2 transport influence the interpretation of bulk dGEMRIC analysis in vivo. In thick cartilage, incomplete penetration of Gd‐DTPA2 will yield a falsely too long T1. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Direct MR arthrography of cadaveric wrists: Comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection
Authors: Donati Olivio F. , Nordmeyer‐Massner Jurek , Nanz Daniel , White Lawrence M. , Tami Ivan , Vich Magdalena , Pruessmann Klaas P. , Andreisek Gustav 
Published: September 2011

AbstractPurpose:To prospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography for the detection of articular cartilage abnormalities at 3.0T and 7.0T in cadaveric wrists.Materials and Methods:MR imaging (MRI) was performed in nine cadaveric wrists (four right wrists, five left; mean age, 81.0 ± 9.8 years) after the intraarticular administration of gadoterate‐meglumine. A 3.0T and 7.0T MR system, mechanically identical custom‐built 8‐channel wrist coil arrays and a similar standard MRI protocol, were used. MR images were evaluated for visibility of articular cartilage surfaces, presence of cartilage lesions, and confidence of diagnosis by two independent radiologists. Open pathologic inspection served as reference standard. Sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV), and accuracy (ACC) were calculated. Wilcoxon signed rank test was used to assess differences in the diagnostic performance.Results:Visibility of articular cartilage surfaces was significantly better at 3.0T than at 7.0T (P < 0.001). Mean sensitivity, specificity, NPV, PPV, ACC for both readers were 63%, 90%, 85%, 76%, 82% at 3.0T, respectively, and 52%, 91%, 82%, 75%, 79% at 7.0T. The difference between 3.0T and 7.0T was not significant for reader 1 (P = 0.51), but was significant for reader 2 (P = 0.01). The level of confidence was significantly higher at 3.0T than at 7.0T for both readers (P = 0.004; P = 0.03).Conclusion:MR arthrography of the wrist at 7.0T is still limited by the lack of commercially available radiofrequency coils and limited experience in sequence optimization, resulting in a significantly lower visibility of anatomy, lower diagnostic accuracy, and level of confidence in judging cartilage lesions compared to 3.0T. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Proteomic analysis of arsenite – mediated multiple antibiotic resistance in Yersinia enterocolitica biovar 1A
Authors: Mallik Sarita , Virdi Jugsharan Singh , Johri Atul Kumar 
Published: September 2011

AbstractArsenic is one of the most important global environmental pollutants. In the present study, fifty one clinical strains of Yersinia enterocolitica biovar 1A showed high resistance to arsenite and arsenate. The minimum inhibitory concentration (MIC) of arsenite (0.625–20 mM) was lower than arsenate (10–80 mM). Growth of Y. enterocolitica in 2 mM arsenite led to 2–8 fold increase in MICs of the five antibiotics (amikacin, ciprofloxacin, gentamycin, kanamycin and tetracycline), suggesting expression of arsenite‐induced multiple antibiotic resistance among the strains. Proteomic analysis of Y. enterocolitica revealed differential expression of certain proteins following arsenite exposure, which included a putative outer membrane porin (OmpA) and a putative amino acid transporter protein. In conclusion, modulation of membrane permeability may be involved in the induction of arsenite–mediated expression of multiple antibiotic resistance in Y. enterocolitica. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of host‐specific Bacteroidales 16S rDNA sequences from human sewage and ruminant feces
Authors: Dorai‐Raj Siobhán , O'Grady Justin , Cormican Martin , Colleran Emer 
Published: September 2011

AbstractThe need to identify the source of fecal contamination of water has led to the development of various fecal source identification methods, a field known as microbial source tracking (MST). One promising method of MST focuses on fecal members of the order Bacteroidales, some of which exhibit a high degree of host‐specificity. In order to identify host‐specific Bacteroidales genetic markers, a ∼1060 bp section of Bacteroidales 16S rDNA was amplified from human sewage (n = 6), and bovine (n = 6) and ovine fecal (n = 5) samples and used for the generation of three clone libraries. Phylogenetic analysis of sequences from the three clone libraries revealed that the Bacteroidales species found in both human sewage and bovine and ovine feces were a highly diverse group of organisms, many of which were not represented by previously characterised 16S rDNA. Ovine and bovine feces appear to host similar populations of Bacteroidales species and these species were more diverse and less closely related to cultivated species than the Bacteroidales population found in human sewage. Species of Bacteroidales from the ruminant and human feces formed isolated clusters containing putatively host‐specific sequences. These sequences were subsequently exploited for the design of host‐specific primers which were used in MST studies. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of foliar and fruit addition of sodium selenate on selenium accumulation and fruit quality
Authors: Pezzarossa Beatrice , Remorini Damiano , Gentile Marialetizia L , Massai Rossano 
Published: September 2011

AbstractBACKGROUND: We investigated the effects of the foliar and fruit application of sodium selenate on selenium (Se) accumulation, fruit growth and ripening in peach and pear. Trials were conducted in two growing seasons. In 2008 selenate was applied at a rate of 0.1 and 1.0 mg Se L−1 to the leaves of peach. In 2009 selenate was applied at a rate of 1 mg Se L−1 via foliar (LT) or fruit (FT) application to peach and pear.RESULTS: The foliar addition of selenate to peach resulted in an increase in Se concentration both in leaves and fruit. The higher Se content in fruit resulted in an increase in flesh firmness and a decrease in soluble solid content. LT significantly increased the Se content in the leaves and fruit of peach and pear, and leaves showed the highest Se concentrations. FT increased the fruit Se concentration in both crops, and it was more effective than LT in increasing Se content. After storage, flesh firmness decreased in all treatments, but it was significantly higher in FT compared to LT and control samples.CONCLUSION: Foliar and fruit selenium spraying appeared effective in increasing the Se content of fruit in peach and pear. The enhanced Se concentration affected the shelf life of fruit, delaying the reduction in flesh firmness and fruit ripening, thus positively affecting fruit storage. Copyright © 2011 Society of Chemical Industry
Effect of dextran layer on protein uptake to dextran‐grafted adsorbents for ion‐exchange and mixed‐mode chromatography
Authors: Yu Lin‐Ling , Shi Qing‐Hong , Sun Yan 
Published: September 2011

AbstractIn the current research, a series of dextran‐grafted adsorbents were prepared using sulfopropyl and 4‐(1H‐imidazol‐1‐yl) aniline as chromatographic ligands for ion‐exchange (IEC) and mixed‐mode chromatography (MMC) to respectively investigate the influence of dextran layer on adsorption of γ‐globulin. Experimental evidences of static adsorption on dextran‐grafted IEC adsorbents showed that adsorption capacity of γ‐globulin increased with dextran content. It could be attributed to the multilayer adsorption of charged protein in dextran layer and thus further induced a significant electrical potential gradient at the boundary of adsorbed area and its proximity, improving mass transfer in combination with concentration gradient. In contrast to IEC adsorbents, adsorption capacity and effective diffusivity of dextran‐grafted MMC adsorbents did not change obviously with dextran grafting. It was considered that hydrophobic ligands immobilized onto dextran‐grafted MMC adsorbents were stuck together at pH 8.0, resulting in the collapse of dextran layer. In concert with measured effective porosity for γ‐globulin at pH 4.0, it was confirmed that dextran layer in MMC adsorbent was more complicated and influenced significantly by buffer pH. It was also manifested by protein adsorption at different pHs. Thus, it revealed the complexity in intraparticle mass transfer of the protein in dextran‐grafted MMC adsorbent.
Molecular Design of Core‐Shell Type Allylic Nanoparticles Based on Crosslinking Multiallyl/Multivinyl Copolymerizations
Authors: Inoue Satoshi , Miwa Yuta , Aota Hiroyuki , Matsumoto Akira , Yokoyama Katsutoshi , Matoba Yasuo , Shibano Michirou 
Published: September 2011

AbstractThis article is referred to the clarification of polymerization characteristics of microgel‐like network polymer precursor (NPP), closely related to the inhomogeneous polymer network formation, in the free‐radical crosslinking (co)polymerization of multivinyl monomers. Firstly, the gelation in free‐radical crosslinking allyl benzoate/diallyl terephthalate (DAT) copolymerization governed by Flory‐Stockmayer gelation theory was explored in the presence of ethylene glycol dimethacrylate (EGDMA) as a typical multivinyl monomer. Since the copolymerizability of allyl monomer with methacrylate monomer is very poor, the crosslinking EGDMA polymerization accompanied by in situ nanogel‐ or microgel‐like methacrylate‐NPP formation was preceded. Secondly, DAT polymerization was carried out with in situ inhomogeneous network formation by a preceded crosslinking EGDMA polymerization. The structures of resulting NPPs were characterized by SEC‐MALLS‐viscometry. Here, the preceded in situ methacrylate‐NPP formation promoted the gelation, never leading to delayed gelation. Finally, our aforementioned discussion was extended to the preparation of novel core‐shell type allylic nanoparticles based on crosslinking multiallyl/multivinyl copolymerizations.
Ultrahigh Tensibility and Stimuli‐Response of Polymer‐Hectorite Nanocomposite Hydrogels
Authors: Hu Xiaobo , Xiong Lijun , Wang Tao , Zhu Meina , Liu Xinxing , Tong Zhen 
Published: September 2011

AbstractSummary: In the field of hydrogels with high mechanical performance, the nanocomposite hydrogel (NC gel) is widely interested due to its unique network structure with extraordinary mechanical, optical, and swelling/deswelling properties. Over the past few years, our group has investigated the fabrication and mechanical properties of a variety of the NC gels with different monomers. The effective network chain density and relaxation were well characterized by dynamic mechanical measurements. From these efforts, we found that the high tensibility of the NC gels came from the low effective network chain density with moderate relaxation. Besides, transparent and ultratensible NC gels with pH response and dual response of pH and temperature have successfully fabricated and characterized. This review will give a brief introduction of our achievements on the understanding of the preparation and properties of NC gels.