bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterising rag‐forming solids
Authors: Kupai Morvarid Madjlessi , Yang Fan , Harbottle David , Moran Kevin , Masliyah Jacob , Xu Zhenghe
Published: May 2013

In oil sands froth treatment, an undesirable intermediate layer, often accumulates during the separation of water–oil emulsions. The layer referred to as rag layer is a complex mixture of water, oil, solids and interfacially active components. The presence of a rag layer has a detrimental impact on the separation of water and fine solids from diluted bitumen. The current study focuses on characterisation of solids from a rag layer forming stream of a naphthenic froth treatment plant in an attempt to understand the mechanism of rag layer formation. Through detailed characterisation of rag‐forming and non‐rag‐forming solids, the mineralogy of solids and their contamination were shown to be critical to rag layer formation. The iron‐based minerals such as siderite and pyrite were found to be enriched within the rag layer. Analysis of surface organic complexes confirms a high level of organic matter associated with these solids through the binding of carboxylic acid group with iron on solids, resulting in a surface hydrophobicity susceptible for rag layer formation.
Fine‐needle aspiration of histoplasmosis in the era of endoscopic ultrasound and endobronchial ultrasound
Authors: Gailey Michael P. , Klutts J. Stacey , Jensen Chris S.
Published: May 2013

BACKGROUND

Histoplasmosis has a textbook cytologic description with numerous intracellular organisms that are readily apparent on routine stains. This is based on series and reports describing histoplasmosis in immunosuppressed patients with disseminated disease. With the advent of ultrasound‐guided (US) fine‐needle aspiration (FNA) techniques, a marked increase in the cytologic diagnosis of histoplasmosis in immunocompetent patients is noted.

METHODS

A search identified all cytology cases diagnosed with Histoplasma within the past 10 years. Cases were reviewed, along with patient demographic, clinical, and laboratory data.

RESULTS

A total of 40 FNA cases of histoplasmosis were identified. Patients ranged in age from 15 years to 86 years. There were 23 female patients and 17 male patients; 37 were immunocompetent and 3 were immunosuppressed. Sixteen patients were being staged for primary tumors of other sites; others presented with primary pulmonary symptoms or histoplasmosis was noted incidentally. Specimens were composed of bland acellular necrosis, most commonly with granulomas (77.5%); only rare intracellular organisms were present on routine stains, and variable extracellular organisms were noted on Grocott methenamine silver stain (GMS) stain. GMS stain on direct smears was found to be more sensitive than cell block. Laboratory studies for urine antigen, yeast, and mycelial antibody (by compliment fixation), serum antibody (by immunodiffusion), and culture were positive in 11.8%, 59.1%, 4.5%, 47.6%, and 3.4% of cases, respectively.

CONCLUSIONS

In an endemic region, histoplasmosis presents more commonly in immunocompetent patients as localized fibrocaseous disease on FNA and is often identified by high‐resolution imaging. FNA is increasingly used in the diagnosis because of endoscopic ultrasound and endobronchial ultrasound. GMS stain on direct smears is more sensitive than cell block. In general, laboratory tests have low sensitivity in this patient population. Cancer (Cancer Cytopathol) 2013;121:508‐17. © 2013 American Cancer Society.
False‐negative rate of endoscopic ultrasound‐guided fine‐needle aspiration for pancreatic solid and cystic lesions with matched surgical resections as the gold standard
Authors: Woolf Kirsten M. W. , Liang Hua , Sletten Zachary J. , Russell Donna K. , Bonfiglio Thomas A. , Zhou Zhongren
Published: May 2013

BACKGROUND

The diagnosis of pancreatic tumors is often complicated because of sampling and interpretive challenges. The current study was performed to determine the rates, types, and causes of diagnostic discrepancies.

METHODS

The authors retrospectively reviewed cytology cases from 2004 to 2010 using matched surgical resection cases as the gold standard.

RESULTS

A total of 733 cases were divided into 3 categories: 1) positive or suspicious (290 cases); 2) negative or atypical (403 cases); and 3) unsatisfactory (40 cases). Of these cases, 101 fine‐needle aspiration (FNA) cases had matched surgical resections including 58 positive diagnoses, 39 negative diagnoses, and 4 unsatisfactory diagnoses. All 19 discrepant cases represented false‐negative diagnoses without any false‐positive cases noted, which included 2 cases with interpretive errors (10%) and 17 cases with sampling errors (90%). All matched cytology cases were divided into 5 subgroups based on the type of lesion or type of error and were analyzed for sensitivity and specificity. The sampling error rate in cystic lesions (8 of 24; 33%) was significantly higher than that in solid lesions (9 of 73; 12%). The false‐negative rate in the interpretive error group (3%) was significantly lower than that in the sampling error group (23%).

CONCLUSIONS

The results of the current study confirm that pancreatic endoscopic ultrasound‐guided FNA diagnosis has a very low false‐positive rate but a relatively high false‐negative rate using matched surgical resections as the gold standard. The major cause of a false‐negative cytology diagnosis is sampling error and the rate of sampling error in cystic lesions is significantly higher than that in solid lesions. Cancer (Cancer Cytopathol) 2013;121:449‐58. © 2013 American Cancer Society.
Pharmacokinetics of Irinotecan With and Without Panitumumab Coadministration in Patients With Metastatic Colorectal Cancer
Authors: Yang Bing‐Bing , Wu Chi‐Yuan , Chen Eric , Infante Jeffrey R. , Chen Alin , Gao Bing , Smith Brian , Litten Jason , Kennecke Hagen
Published: May 2013

This study examined the effects of panitumumab, a human monoclonal antibody against epidermal growth factor receptor (EGFR), on irinotecan pharmacokinetics. This phase I, open‐label, multicenter, single‐arm study enrolled patients with metastatic colorectal cancer (mCRC) without prior exposure to an EGFR inhibitor. In cycle 1, patients received irinotecan (180 mg/m2 intravenously [IV]) on day 1 and panitumumab (6 mg/kg IV) on Day 4. In cycle 2 (2 weeks after cycle 1 panitumumab administration) and subsequent every‐2‐week cycles, patients received panitumumab followed immediately by irinotecan until disease progression or intolerability. Primary and secondary endpoints included Cmax and AUC of irinotecan after irinotecan infusion in cycles 1 and 2, and adverse events, respectively. Nineteen of 27 treated patients were eligible for pharmacokinetic analysis. Pharmacokinetic profiles of irinotecan with or without panitumumab coadministration were nearly identical. The 90% confidence intervals for ratios of geometric means for irinotecan Cmax and AUC with or without panitumumab were within the 80–125% interval, indicating that panitumumab had no apparent effects on irinotecan pharmacokinetics. Adverse events were as expected for irinotecan plus panitumumab combination therapy.
Treating eating disorders over the internet: A systematic review and future research directions
Authors: Aardoom Jiska J. , Dingemans Alexandra E. , Spinhoven Philip , Van Furth Eric F.
Published: May 2013

Objective

To review the literature regarding internet‐based treatment of eating disorders (ED).

Method

Relevant studies were identified by searching electronic databases (including Medline, Embase, PsycInfo, and Web of Science). Eligible studies evaluated an internet‐based treatment for ED, or an ED treatment that included at least one internet‐based component.

Results

Twenty‐one studies were included. Methodological quality varied. Internet‐based treatments were superior to waiting lists in reducing ED psychopathology, frequency of binge eating and purging, and in improving (ED‐related) quality of life. Internet‐based treatment was more effective for individuals with less comorbid psychopathology, binge eating as opposed to restrictive problems, and individuals with binge eating disorder as opposed to bulimia nervosa. Higher levels of compliance were related to more improvements in ED symptoms. Study dropout ranged from 5.3 to 76.8%. Inclusion of face‐to‐face assessments and therapist support seemed to enhance study compliance. Overall, the internet can be considered an acceptable vehicle for delivering ED treatment.

Discussion

Future research should determine the utility of internet‐based treatment by comparing them to face‐to‐face treatment. Research should furthermore focus on unraveling predictors and mediators of treatment outcome, compliance, and dropout, respectively. Studies with good methodological quality are needed with reports according to CONSORT guidelines. © 2013 by Wiley Periodicals, Inc. (Int J Eat Disord 2013; 46:539–552)
5‐Cyanotetrazolate as a Ligand and Linker in Copper(II) Complexes and Coordination Polymers
Authors: Szafranowska Barbara , Beck Johannes
Published: May 2013

5‐Cyanotetrazole readily forms from (CN)2 and HN3. The coordination abilities of the 5‐cyanotetrazolate anion N4CCN– (ctz) towards CuII ions were examined and a series of complexes and coordination polymers were synthesized and characterized by single‐crystal structure analyses: PPh4[Cu(ctz)3] (1), [Cu(ctz)2(bipy)] (2, bipy = 2,2′‐bipyridine), [CuCl(py)4](ctz)·2py (3, py = pyridine), [Cu2(ctz)6Cu(CH3CN)2(H2O)2]·2CH3CN (4a), [Cu2(ctz)6Cu(H2O)3{(CH3)2CO}]·3(CH3)2CO (4b), [Cu(ctz)2(py)4] (5), [Cu2(ctz)4(bipy)2] (6) and [Cu2(ctz)2(tpm)2(NO3)]NO3 [7, tpm = tris(pyrazol‐1‐yl)methane]. As ctz is a multidentate linker, additional neutral coligands such as monodentate py, bidentate bipy and tridentate tpm ligands were used to avoid the formation of noncrystalline polymers. The structures of 1–7 reflect the versatile coordination abilities of ctz in the various types of coordination environments of the CuII ions and dimensionalities of the linkages. The structures represent 1D chain motifs (1, 2 and 3), 2D layered structures (4a and 4b), mononuclear (5) and dinuclear complexes (6 and 7). Magnetic coupling phenomena were detected by susceptibility measurements of 1, 4a, 6 and 7, which were fitted to the magnetic models according to antiferromagnetic spin‐pairing of two S = 1/2 systems (Bleaney–Bowers) for 6 (J = –0.53 cm–1) and 7 (J = –2.91 cm–1), to the ferromagnetic high‐temperature series expansion based on the Baker 1D (S = 1/2) chain model for 1 (J = +14.4 cm–1) and to the Néel model of ferrimagnetism for 4a. The diverse magnetic interactions between the Cu2+ sites are communicated by the bridging ctz anions.
Short Synthetic Route to Benzaldehyde‐Functionalized Idose and Talose Derivatives by Acetoxonium Ion Rearrangements
Authors: Kopitzki Sebastian , Thiem Joachim
Published: May 2013

Carbohydrate–carbohydrate interactions (CCI) are mediated by complexation of metal ions. Angyal postulated on the requirements for hydroxy group arrangement in pyranoses to account for metal‐ion complexation. These requirements are particularly well fulfilled in α‐ido‐ and α‐talopyranosides, whose ring hydroxy groups have all axial and axial‐equatorial‐axial configurations, respectively. Surface plasmon resonance (SPR) and gold‐nanoparticle techniques have proved to be powerful tools to investigate CCIs. Benzaldehyde‐functionalized glycans can be used for attachment to both gold nanoparticles and SPR sensor surfaces. Therefore, benzaldehyde‐equipped ido‐ and talopyranosides were synthesized by the almost forgotten Paulsen acetoxonium rearrangement. This approach provides peracetylated idose and talose in only two steps from common glucose and galactose precursors, respectively, in overall yields of up to 41 % and, therefore, avoids long and laborious procedures to obtain these rare carbohydrates. The derivatives are being used in ongoing CCI studies using SPR to test Angyal's postulate about the structural requirements for hydroxy group arrangements.
A Route to 2‐Alkenyl‐3‐(tert‐butyldiphenylsilyl)amines and Application to the Construction of a Tricyclic Ring System
Authors: Yadav Veejendra K. , Narhe Bharat D. , Kumar Kamlesh , Hulikal Vijaykumar
Published: May 2013

N‐Tosyl 3,3‐dialkyl‐2‐(tert‐butyldiphenylsilylmethyl)azetidines rearrange smoothly into the corresponding 2‐alkenyl‐3‐(tert‐butyldiphenylsilyl)amines upon exposure to BF3·OEt2 in CH2Cl2. The reaction involves sequential σC–N bond cleavage, 1,2‐migration of the N‐tosyl‐aminomethyl group, and deprotonation of the resultant tert‐carbenium ions. For the instance in which the carbenium ion formed from migration of the N‐tosyl‐aminomethyl group is highly stable by virtue of being, for example, tertiary as well as benzylic, the migration takes place in sync with σC–N bond cleavage, which leads to high configurational control at the tert‐butyldiphenylsilylmethyl‐bearing carbon atom in the product.
A Ferrocene‐Tagged Amyloid‐β Fragment for Rapid Screening of Aggregation Inhibitors from Natural Compounds by HPLC‐Electrochemical Detection
Authors: Zhang Lin , Kai Tianhan , Sun Zhifang , Hao Yuanqiang , Tu Qiuyun , Zhou Feimeng
Published: May 2013

Aggregates of amyloid beta (Aβ) peptides are believed to be responsible for the neuropathology of Alzheimer’s disease. In this work, ferrocene (Fc) is attached to the aggregating core of the Aβ peptides, KLVFFAE. Inhibition of Fc‐KLVFFAE aggregation by curcumin, a natural compound, was monitored by HPLC‐electrochemical detection (HPLC‐EC). The Fc oxidation current is dependent on the incubation condition and curcumin can retain Fc‐KLVFFAE in its monomeric form. We demonstrate that tagging Fc to KLVFFAE affords a cost‐effective and electroactive mimicry of Aβ(142) and HPLC‐EC is suitable for sensitive, reproducible, and facile screening of drugs for inhibiting the aggregation of Aβ peptides.
Dependence of the climate prediction skill on spatiotemporal scales: Internal versus radiatively‐forced contribution
Authors: Volpi D. , Doblas‐Reyes F. J. , García‐Serrano J. , Guemas V.
Published: May 2013

This article aims at quantifying the improvement in climate prediction skill as a function of temporal (from monthly to decadal) and spatial scales (from grid point to global) when initializing a perturbed parameter ensemble of the Hadley Centre Climate Model. The focus is on near‐surface temperature and precipitation in the Tropical band, the Northern and Southern hemispheres. For temperature, the forecast system reproduces the dominant impact of the external forcing at global spatial scale and at decadal time scales. There are significant improvements with initialization for the first 40 forecast months in the global and tropical domains. In the Northern (Southern) hemisphere, the initialization increases the skill in the first 12 (20) months on regional but not hemispheric scales. The initialization has a stronger impact in the model variants with a weaker global‐mean temperature trend. For precipitation, the initialization corrects the negative correlation found at global and tropical scales.
Impact of CO2 fertilization on maximum foliage cover across the globe's warm, arid environments
Authors: Donohue Randall J. , Roderick Michael L. , McVicar Tim R. , Farquhar Graham D.
Published: May 2013

Satellite observations reveal a greening of the globe over recent decades. The role in this greening of the “CO2 fertilization” effect—the enhancement of photosynthesis due to rising CO2 levels—is yet to be established. The direct CO2 effect on vegetation should be most clearly expressed in warm, arid environments where water is the dominant limit to vegetation growth. Using gas exchange theory, we predict that the 14% increase in atmospheric CO2 (1982–2010) led to a 5 to 10% increase in green foliage cover in warm, arid environments. Satellite observations, analyzed to remove the effect of variations in precipitation, show that cover across these environments has increased by 11%. Our results confirm that the anticipated CO2 fertilization effect is occurring alongside ongoing anthropogenic perturbations to the carbon cycle and that the fertilization effect is now a significant land surface process.
Trabecular Homogeneity Index Derived From Plain Radiograph to Evaluate Bone Quality
Authors: Thevenot Jérôme , Hirvasniemi Jukka , Finnilä Mikko , Pulkkinen Pasi , Kuhn Volker , Link Thomas , Eckstein Felix , Jämsä Timo , Saarakkala Simo
Published: May 2013

Radiographic texture analysis has been developed lately to improve the assessment of bone architecture as a determinant of bone quality. We validate here an algorithm for the evaluation of trabecular homogeneity index (HI) in the proximal femur from hip radiographs, with a focus on the impact of the principal compressive system of the trabecular bone, and evaluate its correlation with femoral strength, bone mineral density (BMD), and volumetric trabecular structure parameters. A semiautomatic custom-made algorithm was applied to calculate the HI in the femoral neck and trochanteric areas from radiographs of 178 femoral bone specimens (mean age 79.3 ± 10.4 years). Corresponding neck region was selected in CT scans to calculate volumetric parameters of trabecular structure. The site-specific BMDs were assessed from dual-energy X-ray absorptiometry (DXA), and the femoral strength was experimentally tested in side-impact configuration. Regression analysis was performed between the HI and biomechanical femoral strength, BMD, and volumetric parameters. The correlation between HI and failure load was R2 = 0.50; this result was improved to R2 = 0.58 for cervical fractures alone. The discrimination of bones with high risk of fractures (load <3000 N) was similar for HI and BMD (AUC = 0.87). Regression analysis between the HIs versus site-specific BMDs yielded R2 = 0.66 in neck area, R2 = 0.60 in trochanteric area, and an overall of R2 = 0.66 for the total hip. Neck HI and BMD correlated significantly with volumetric structure parameters. We present here a method to assess HI that can explain 50% of an experimental failure load and determines bones with high fracture risk with similar accuracy as BMD. The HI also had good correlation with DXA and computed tomography–derived data. © 2013 American Society for Bone and Mineral Research.
Siglec-15 Regulates Osteoclast Differentiation by Modulating RANKL-Induced Phosphatidylinositol 3-Kinase/Akt and Erk Pathways in Association With Signaling Adaptor DAP12
Authors: Kameda Yusuke , Takahata Masahiko , Komatsu Miki , Mikuni Shintaro , Hatakeyama Shigetsugu , Shimizu Tomohiro , Angata Takashi , Kinjo Masataka , Minami Akio , Iwasaki Norimasa
Published: May 2013

Siglecs are a family of sialic acid–binding immunoglobulin-like lectins that regulate the functions of cells in the innate and adaptive immune systems through glycan recognition. Here we show that Siglec-15 regulates osteoclast development and bone resorption by modulating receptor activator of nuclear factor κB ligand (RANKL) signaling in association with DNAX-activating protein 12 kDa (DAP12), an adaptor protein bearing an immunoreceptor tyrosine-based activation motif (ITAM). Among the known Siglecs expressed in myeloid lineage cells, only Siglec-15 was upregulated by RANKL in mouse primary bone marrow macrophages. Siglec-15–deficient mice exhibit mild osteopetrosis resulting from impaired osteoclast development. Consistently, cells lacking Siglec-15 exhibit defective osteoclast development and resorptive activity in vitro. RANKL-induced activation of phosphatidylinositol 3-kinase (PI3K)/Akt and Erk pathways were impaired in Siglec-15–deficient cells. Retroviral transduction of Siglec-15–null osteoclast precursors with wild-type Siglec-15 or mutant Siglec-15 revealed that the association of Siglec-15 with DAP12 is involved in the downstream signal transduction of RANK. Furthermore, we found that the ability of osteoclast formation is preserved in the region adjacent to the growth plate in Siglec-15–deficient mice, indicating that there is a compensatory mechanism for Siglec-15–mediated osteoclastogenesis in the primary spongiosa. To clarify the mechanism of this compensation, we examined whether osteoclast-associated receptor (OSCAR)/Fc receptor common γ (FcRγ) signaling, an alternative ITAM-mediated signaling pathway to DAP12, rescues impaired osteoclastogenesis in Siglec-15–deficient cells. The ligands in type II collagen activate OSCAR and rescue impaired osteoclastogenesis in Siglec-15–deficient cells when cultured on bone slices, indicating that Siglec-15–mediated signaling can be compensated for by signaling activated by type II collagen and other bone matrix components in the primary spongiosa. Our findings indicate that Siglec-15 plays an important role in physiologic bone remodeling by modulating RANKL signaling, especially in the secondary spongiosa. © 2013 American Society for Bone and Mineral Research.
Three‐dimensional multifluid modeling of atmospheric electrodynamics in Mars' dynamo region
Authors: Riousset Jeremy A. , Paty Carol S. , Lillis Robert J. , Fillingim Matthew O. , L. England Scott , Withers Paul G. , M. Hale John P.
Published: May 2013

The interactions between Mars' unique crustal magnetic fields and upper atmospheric particles lead to the formation of currents in the ionospheric dynamo region. This work is specifically focused on the collisions between ions, electrons, and neutrals in the atmospheric column of Mars. The remanent fields embedded in the Martian crust generate a very rich magnetic topology with important variations in terms of geometry and amplitude. Here we present mesoscale, self‐consistent, three‐dimensional, multifluid simulations of Mars' ionospheric electrodynamics in the dynamo region (∼100–400 km altitude), where differential motions of ions and electrons occur. In particular, we develop and validate a new method through the study of simple, uniform magnetic geometries. Our results demonstrate the existence of a dynamo current in the Martian atmosphere, which depends on the magnitude of the applied magnetic field and the neutral wind speeds. The simulation outputs are analyzed from mathematical and physical perspectives to identify the dominant processes at work in the formation of this current. Both case studies presented in this paper are qualitatively and quantitatively consistent with theoretical estimates and confirm the validity of the model, hence laying the groundwork for future studies of Mars' atmosphere using this new approach.
A domain decomposition approach to implementing fault slip in finite‐element models of quasi‐static and dynamic crustal deformation
Authors: Aagaard B. T. , Knepley M. G. , Williams C. A.
Published: May 2013

We employ a domain decomposition approach with Lagrange multipliers to implement fault slip in a finite‐element code, PyLith, for use in both quasi‐static and dynamic crustal deformation applications. This integrated approach to solving both quasi‐static and dynamic simulations leverages common finite‐element data structures and implementations of various boundary conditions, discretization schemes, and bulk and fault rheologies. We have developed a custom preconditioner for the Lagrange multiplier portion of the system of equations that provides excellent scalability with problem size compared to conventional additive Schwarz methods. We demonstrate application of this approach using benchmarks for both quasi‐static viscoelastic deformation and dynamic spontaneous rupture propagation that verify the numerical implementation in PyLith.
Multiscale variability in the Balearic Sea: An altimetric perspective
Authors: Mason Evan , Pascual Ananda
Published: May 2013

The present‐day availability of an 18 year record of
merged Mediterranean Sea sea level anomaly (SLA) data enables a contemporary description of long‐term mesoscale activity in the Balearic Sea. SLA data from satellite altimetry are used to study the variability of sea level and surface geostrophic circulation at different spatial and temporal scales within this complex and relatively understudied region in the western Mediterranean (WMED). We find that the mean Northern Current along the Iberian slope is strongest in autumn, although higher variability in winter leads to stronger peaks in kinetic energy. The Balearic Current, which flows along the northern slopes of the Balearic islands, also has its maximum expression in autumn. Across the two Balearic channels (Ibiza and Mallorca), key locations that partly regulate meridional exchange in the WMED, observed seasonal variability in geostrophic velocity anomalies conforms rather well to prior descriptions, suggesting cautious confidence in the use of the Mediterranean merged altimeter product in nearshore regions. Circulation through the channels is maximum in winter. The channel data support the hypothesis that the channel circulation may be hindered by the intermittent presence of the Western Intermediate Water mass, which sometimes forms in winter in the Gulf of Lions. This is the first time that an analysis of variability in the Balearic channels has been performed using altimetric data.
Petrological modeling of basaltic rocks from Venus: A case for the presence of silicic rocks
Authors: Shellnutt J. Gregory
Published: May 2013

The presence of highly evolved igneous rocks on Venus is a controversial issue. The formations of highland terranes and pancake domes are the two principal tectonic and volcanic features which argue in favor of the presence of silicic igneous rocks; however, the lack of water on Venus casts doubt on whether or not granites and rhyolites can form. Data returned to Earth from the Venera 13 and 14 landers show that the surface of Venus is composed of basaltic rocks similar in composition to those found on Earth. Here it is shown that anhydrous and hydrous fractional crystallization modeling using the Venera 13 and 14 data as starting materials can produce compositions similar to terrestrial phonolites and rhyolites. It is suggested that at shallow crustal levels (i.e., ≤ 0.1 GPa), mafic magmas can differentiate into silicic magmas resembling phonolites or rhyolites which may or may not erupt. Furthermore, the hydrous equilibrium partial melting models can produce rocks similar to terrestrial andesites and rhyolites, whereas anhydrous models suggest that there may be a uniquely Venusian type of silicic rock. The silicic rocks, if present, could act as “continental nucleation” sites and/or their presence may facilitate preferential sites of shearing and deformation of the Venusian crust.
Crushed rephased orthogonal slice selection (CROSS) for simultaneous acquisition of two orthogonal proton resonance frequency temperature maps
Authors: Krafft Axel J. , Rauschenberg Jaane , Maier Florian , Jenne Jürgen W. , Bock Michael
Published: May 2013

Purpose

To evaluate a novel imaging sequence termed crushed rephased orthogonal slice selection (CROSS) that uses the available time in long echo time (TE) gradient echo (GRE) imaging—as employed for proton resonance frequency (PRF) shift thermometry—to simultaneously acquire two orthogonal magnetic resonance imaging (MRI) temperature maps around the target region.

Materials and Methods

The CROSS sequence encodes a second orthogonal slice between excitation and data readout in long‐TE imaging and applies dedicated crusher (CR) gradients to separate the signals from the two slices. Numerical simulations of the Bloch equations and phantom experiments were performed to analyze the MR signal. In phantom and in vivo experiments with two domestic pigs, the applicability of the CROSS sequence for temperature mapping of thermal therapies with focused ultrasound and laser was studied.

Results

A successful separation of the signals from the two slices was achieved for CR dephasing lengths approaching the in‐plane resolution. In the two animal experiments, CROSS temperature mapping could be successfully demonstrated at a temporal resolution of 2–3 seconds and a temperature uncertainty of 3–4K.

Conclusion

At the expense of a reduced signal in the overlap of the two slices, the CROSS sequence achieves an improvement of temporal resolution by 50%, without requiring further acceleration techniques such as parallel imaging, over conventional sequential GRE sequences employing the same repetition time as the CROSS sequence acquires two slices within one repetition interval. J. Magn. Reson. Imaging 2013;38:1510–1520. © 2013 Wiley Periodicals, Inc.
Prognostic value of the D‐dimer test in oesophageal cancer during the perioperative period
Authors: Diao Dongmei , Zhu Kun , Wang Zhe , Cheng Yao , Li Kang , Pei Leilei , Dang Chengxue
Published: May 2013

Background

There has been little research on the perioperative D‐dimer levels in oesophageal cancer patients. Plasma D‐dimer levels can be used to predict the outcome in cancer patients.

Methods

A cancer group of 66 oesophageal cancer patients and a control group of 12 patients with benign disease were enrolled in this cohort study. The plasma D‐dimer levels during the pre‐operation and 3rd and 9th day post‐operation periods were prospectively examined and analysed between the two groups. Plasma D‐dimer levels were also compared with the clinicopathological characteristics and 3‐year survival of the oesophageal cancer patients.

Results

Plasma D‐dimer levels increased in both groups after surgery, but they were significantly higher in the cancer group. In oesophageal cancer patients, pre‐operation plasma D‐dimer levels were significantly higher in TNM stage IV patients. Perioperative plasma D‐dimer levels significantly increased after surgery, and the survival was shortened in those patients whose D‐dimer levels on the 3rd and 9th post‐operative day above the median. In addition, increased plasma D‐dimer levels at the 3rd and 9th days after surgery were influenced by the patient's age.

Conclusion

In oesophageal cancer patients, D‐dimer levels increased after surgery, and the increases were associated with poor outcomes. J. Surg. Oncol. 2013 108:34–41. © 2013 Wiley Periodicals, Inc.
The Role of Shape and Size of Guest Molecules in the Formation of Clathrates and Intercalates of Syndiotactic Polystyrene
Authors: Tarallo Oreste , Auriemma Finizia , de Ballesteros Odda Ruiz , Di Girolamo Rocco , Diletto Claudia , Malafronte Anna , De Rosa Claudio
Published: May 2013

The crystal structure of syndiotactic polystyrene (sPS) co‐crystals of δ‐class is discussed with the aim of identifying molecular descriptors that allow predicting the lattice distortions induced by the inclusion of guest molecules inside the cavities of the nanoporous δ‐form. Based on the consideration that monoclinic and triclinic clathrates and intercalates of sPS form as a result of the unique deformability of the cavities of the δ‐form, the identified parameters are the fractional occupancy factors of the undeformed cavity of the δ‐form from guests along the a‐axis, the c‐axis, and the normal to the (010) planes of the crystals, and the relative orientation of the guests to the chain axes.

magnified image
Association between baseline fetal hemoglobin levels and incidence of severe vaso‐occlusive pain episodes in children with sickle cell anemia
Authors: Bhatnagar Pallav , Keefer Jeffrey R. , Casella James F. , Barron‐Casella Emily A. , Bean Christopher J. , Hooper Craig W. , Payne Amanda B. , Arking Dan E. , Debaun Michael R.
Published: May 2013

The ameliorating effect of high fetal hemoglobin (HbF) levels on the incidence of pain episodes in sickle cell anemia (SCA) is well‐known; however, in children this relationship is less clearly established. We hypothesized that higher HbF levels in children with SCA are associated with fewer severe pain episodes. A meta‐analysis of data from the Silent Infarct Transfusion Trial (n = 456) and the Cooperative Study of Sickle Cell Disease (n = 764), demonstrated that baseline HbF levels were associated with the incidence of severe pain, commonly defined across studies as an event requiring hospitalization (P‐value = 0.02). Pediatr Blood Cancer 2013;60:E125–E127. © 2013 Wiley Periodicals, Inc.
The role of noninvasive prenatal testing as a diagnostic versus a screening tool – a cost‐effectiveness analysis
Authors: Ohno Mika , Caughey Aaron
Published: May 2013

Objective

As the sensitivity and specificity of noninvasive prenatal testing (NIPT) that uses cell‐free fetal DNA in maternal serum to identify Down syndrome (DS) in utero improves, NIPT could be considered a diagnostic test, thus avoiding the complications of chorionic villus sampling or amniocentesis. This study investigates the cost‐effectiveness of NIPT as a diagnostic versus a screening tool.

Method

A decision‐analytic model compared NIPT as a diagnostic tool (NIPT Dx) that did not require a confirmatory amniocentesis versus NIPT used for screening (NIPT Scr) that allowed a confirmatory amniocentesis for screen positive results. Baseline case, univariate, and multivariate sensitivity analyses were performed.

Results

For a high‐risk population, NIPT Dx would result in three more DS babies born and 2432 more elective terminations compared with NIPT Scr. Furthermore, there would be many more terminations of fetuses without DS with NIPT Dx (2424) than procedure‐related losses associated with NIPT Scr (29). NIPT Scr is more expensive but cost‐effective at $7687 per quality‐associated life year (QALY), less than the standard cost‐effectiveness limit of $100 000/QALY.

Conclusions

Noninvasive prenatal testing as a screening tool that requires a confirmatory amniocentesis is cost‐effective compared with its use as a diagnostic tool and leads to far fewer losses of normal pregnancies. © 2013 John Wiley & Sons, Ltd.
Euglycaemic ketoacidosis in patients with and without diabetes
Authors: Le Neveu Francine , Hywel Brython , Harvey John N
Published: May 2013

Ketoacidosis in individuals with diabetes is usually associated with a raised plasma glucose concentration. However, ketoacidosis in diabetes can occur with normal (≤11mmol/L) plasma glucose levels. Ketoacidosis is also seen in patients who do not have diabetes, most commonly in pregnancy or following alcoholic binges, rarely with starvation, anorexia nervosa or inborn errors of metabolism. The aim of this review is to compare the clinical features, pathophysiology and management of these conditions.

Common clinical features due to a raised anion gap metabolic acidosis are seen. Reduced carbohydrate intake is a usual contributor to ketogenesis. Treatment is primarily with intravenous glucose, insulin if there is insulin deficiency and potassium as needed. The value of using bedside monitors to measure β‐hydroxybutyrate levels both for diagnosis and monitoring of response to treatment is emphasised. Early recognition of ketoacidosis and treatment with glucose rather than saline is important for optimum outcome. Copyright © 2013 John Wiley & Sons. Practical Diabetes 2013; 30(4): 167–171
Vinylimidazole‐based asymmetric ion pair comonomers: Synthesis, polymerization studies and formation of ionically crosslinked PMMA
Authors: Jana Satyasankar , Vasantha Vivek Arjunan , Stubbs Ludger Paul , Parthiban Anbanandam , Vancso Julius G.
Published: May 2013

Vinylimidazole‐based asymmetric ion pair comonomers (IPCs) which are free from nonpolymerizable counter ions have been synthesized, characterized and polymerized by free radical polymerization (FRP), atom transfer radical polymerization (ATRP), and reversible addition‐fragmentation chain transfer (RAFT) mediated polymerizations in solution and by dispersion polymerization in water. The asymmetric nature of IPCs is due to the fact that cationic component of these IPCs is derived from vinylimidazole (VIm) and anionic component is derived from either styrenesulfonate (SS) or 2‐acrylamido‐2‐methyl‐1‐propanesulfonate. Although under ATRP, conversions are either very low or negligible, FRP and RAFT produces polymers with high to moderate monomer conversions but with different solubility characteristics. This investigation provides insight to the polymerization behavior of each component of the asymmetric IPCs and also its effects on composition and solubility characteristics of the resulting polymers. The IPCs studied here are high temperature ionic liquid and thus the polymers synthesized from these IPCs are highly ionic in nature and possess very strong intermolecular interactions which makes some of these IPC based polymers completely insoluble in organic and aqueous solvents. This highly ionic interaction is exploited to synthesize ionically crosslinked PMMA. MMA on copolymerization with 5–6 mol % of IPC yielded copolymer which is insoluble in common organic solvents like THF, DMF, etc., unlike homo PMMA. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3260–3273
Aldose Reductase Inhibitors of Plant Origin
Authors: Veeresham Ciddi , Rama Rao Ajmeera , Asres Kaleab
Published: May 2013

Diabetic complications are attributed to hyperglycaemic condition which is in turn associated with the polyol pathway and advanced glycation end products. Aldose reductase (AR) is the principal enzyme of polyol pathway which plays a vital role in the development of diabetic complications. AR inhibitory activity can be screened by both in vitro and in vivo methods. In vitro assays for AR enzyme are further classified on the basis of the source of enzyme such as rat lens, rat kidney, cataracted human eye lens, bovine eyes and human recombinant AR enzymes, whereas the in vivo model is based on the determination of lens galactitol levels. A number of synthetic AR inhibitors (ARIs) including tolrestat and sorbinil have been developed, but all of these suffer from drawbacks such as poor permeation and safety issues. Therefore, pharmaceutical companies and many researchers have been carrying out research to find new, potent and safe ARIs from natural sources. Thus, many naturally occurring compounds have been reported to have AR inhibitory activity. The present review attempts to highlight phytochemicals and plant extracts with potential AR inhibitory activity. It also summarizes the classes of compounds which have proven AR inhibitory activity. Phytochemicals such as quercetin, kaempferol and ellagic acid are found to be the most promising ARIs. The exhaustive literature presented in this article clearly indicates the role of plant extracts and phytochemicals as potential ARIs. Copyright © 2013 John Wiley & Sons, Ltd.
Learners' Beliefs as Mediators of What Is Noticed and Learned in the Language Classroom
Authors: Kartchava Eva , Ammar Ahlem
Published: May 2013

The goal of this study was to determine whether learner beliefs regarding corrective feedback mediate what is noticed and learned in the language classroom. The participants were four groups of high‐beginner college‐level francophone English as a second language learners and their teachers. Each teacher was assigned to a treatment condition that fit his corrective feedback style, and each provided feedback in response to errors with the past tense and questions in the past. Participants (N = 197) completed a beliefs questionnaire, and half (n = 99) took part in the intervention that followed. Beliefs were probed using a 40‐item questionnaire, and average belief scores were calculated for each learner. These were then correlated both with the noticing reported on an immediate recall measure and with the test scores on picture description and spot‐the‐differences tasks. The results reveal four common beliefs, two of which mediated the noticeability of the supplied feedback, but none of which impacted the learning outcomes.
Haptic perception
Authors: Kappers Astrid M.L. , Bergmann Tiest Wouter M.
Published: May 2013

Fueled by novel applications, interest in haptic perception is growing. This paper provides an overview of the state of the art of a number of important aspects of haptic perception. By means of touch we can not only perceive quite different material properties, such as roughness, compliance, friction, coldness and slipperiness, but we can also perceive spatial properties, such as shape, curvature, size and orientation. Moreover, the number of objects we have in our hand can be determined, either by counting or subitizing. All these aspects will be presented and discussed in this paper. Although our intuition tells us that touch provides us with veridical information about our environment, the existence of prominent haptic illusions will show otherwise. Knowledge about haptic perception is interesting from a fundamental viewpoint, but it also is of eminent importance in the technological development of haptic devices. At the end of this paper, a few recent applications will be presented. WIREs Cogn Sci 2013, 4:357–374. DOI: 10.1002/wcs.1238

This article is categorized under:

Psychology > Perception and Psychophysics
Interpolation of precipitation under topographic influence at different time scales
Authors: Bárdossy András , Pegram Geoffrey
Published: May 2013

In this paper, new methodologies for interpolating rainfall data in individual time intervals (ranging from a day to a year) using Gaussian copulas and unsymmetrical v‐copulas, with a variety of treatments of altitude as an exogenous variable, are described. For shorter time aggregations, zeros were treated as censored variables. For each selected time step, the marginal distributions of precipitation amounts were modeled using nonparametric density estimators, while the spatial dependence structures were estimated using a maximum likelihood methodology. The methodology was compared to other common geostatistical interpolators such as ordinary kriging and external drift kriging. Several measures of bias and error structure have been used to assess the efficacy of the methods in a range of comparative split‐sampling studies. The data set chosen for the study comprises daily precipitation time series over 41 years in three regions in Germany measured at more than 1200 locations over a large area (126,144 km2). Among the many findings in the paper, the ones that stand out are: (i) correlation between precipitation and topography increases with the length of time interval and is significantly improved by directional smoothing of topography; (ii) the copula methods are superior to kriging methods in terms of quality of interpolation (bias and uncertainty estimation); (iii) the treatment of zeros as censored variables improves interpolation quality for daily and pentad values (monthly and annual data in this region present no dry periods); (iv) the copula methods yield full conditional distributions of estimates at a target point, in an interval, improving substantially on the simple uncertainty estimates derived from kriging; and (v) the Gauss copula in particular performs best overall in terms of computational efficiency, combined with useful error profiles in the interpolations, and of all methods is the most realistic in its error estimates.
Translation regulation gets its ‘omics’ moment
Authors: Kuersten Scott , Radek Agnes , Vogel Christine , Penalva Luiz O. F.
Published: May 2013

The fate of cellular RNA is largely determined by complex networks of protein–RNA interactions through ribonucleoprotein (RNP) complexes. Despite their relatively short half‐life, transcripts associate with many different proteins that process, modify, translate, and degrade the RNA. Following biogenesis some mRNPs are immediately directed to translation and produce proteins, but many are diverted and regulated by processes including miRNA‐mediated mechanisms, transport and localization, as well as turnover. Because of this complex interplay estimates of steady‐state expression by methods such as RNAseq alone cannot capture critical aspects of cellular fate, environmental response, tumorigenesis, or gene expression regulation. More selective and integrative tools are needed to measure protein–RNA complexes and the regulatory processes involved. One focus area is measurements of the transcriptome associated with ribosomes and translation. These so‐called polysome or ribosome profiling techniques can evaluate translation efficiency as well as the interplay between translation initiation, elongation, and termination—subject areas not well understood at a systems biology level. Ribosome profiling is a highly promising technique that provides mRNA positional information of ribosome occupancy, potentially bridging the gap between gene expression (i.e., RNAseq and microarray analysis) and protein quantification (i.e., mass spectrometry). In combination with methods such as RNA immunoprecipitation, miRNA profiling, or proteomics, we obtain a fresh view of global post‐transcriptional and translational gene regulation. In addition, these techniques also provide new insight into new regulatory elements, such as alternative open reading frames, and translation regulation under different conditions. WIREs RNA 2013, 4:617–630. doi: 10.1002/wrna.1173

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes

Translation > Translation Mechanisms

Translation > Translation Regulation
A First‐Principles Study of Electronic Structure of the Laves Phase MgZn2
Authors: Andrae Dirk , Paulus Beate , Wedig Ulrich , Jansen Martin
Published: May 2013

The electronic structure of the intermetallic compound MgZn2, a prototypical Laves phase, was investigated by first‐principles calculations based on Kohn‐Sham density‐functional theory. A variety of six exchange‐correlation energy density functionals, from local density approximation to hybrid functionals, was used to fully optimize the crystal structure. Cell parameters and mass density calculated with the density functional parameterization by Perdew, Burke, and Ernzerhof (PBE) were found closest to their corresponding experimental values. The revised version of the functional, PBEsol, recommended for solid state applications, gave inferior results. The electronic structure was analysed in terms of band structure, density of states and electron density.
R-charge conservation and more in factorizable and non-factorizable orbifolds
Authors: Bizet Nana G. Cabo , Kobayashi Tatsuo , Peña Damián K. Mayorga , Parameswaran Susha L. , Schmitz Matthias , Zavala Ivonne
Published: May 2013

Abstract

We consider the string theory origin of R-charge conservation laws in heterotic orbifold compactifications, deriving the corresponding string coupling selection rule for factorizable and non-factorizable orbifolds, with prime ordered and non-prime ordered point groups. R-charge conservation arises due to symmetries among the worldsheet instantons that can mediate the couplings. Among our results is a previously missed non-trivial contribution to the conserved R-charges from the γ-phases in non-prime orbifolds, which weakens the R-charge selection rule. Symmetries among the worldsheet instantons can also lead to additional selection rules for some couplings. We make a similar analysis for Rule 4 or the “torus lattice selection rule”. Moreover, we identify a new string selection rule, that we call Rule 6 or the “coset vector selection rule”.