bluuebunny/crossref_metadata_2025 huggingface dataset:
SAXS study on deformation behavior of isotactic polypropylene under pressurized CO2
Authors: Osaka Noboru , Kono Fumiya , Saito Hiromu
Published: May 2012

Tensile‐deformation behavior and structure change of isotactic polypropylene (iPP) under pressurized CO2 were investigated by using in situ tensile‐deformation instruments and small‐angle X‐ray scattering (SAXS) measurements. Tensile strength including yield stress, plateau stress, and tensile modulus decreased with increase of CO2 pressure, suggesting that expansion of amorphous regions by absorbing CO2 allows crystalline lamellae to deform easily with less entanglement. Under CO2, the specimens became opaque beyond yield point and strong equatorial streaks appeared in two‐dimensional SAXS patterns. By using Ruland's streak method, they are attributed to formation of nanometer‐sized voids larger than the periodic distance of crystalline lamellae. An azimuthal profile of the lamellar peak was sharper under pressurized CO2 than that under ambient pressure. This meant that the easy rotation of the crystalline lamellae by CO2 results in the preferred orientation of the crystalline lamellae, which caused formation of the nanometer‐sized voids at the interspace in the polymer matrix between lamellar stacks. Owing to the formation of the nanometer‐sized voids, the elongation was enhanced in the second stage stretching of the stretched iPP at ambient pressure after depressurization. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
State diagram of phase transition temperatures and solvent‐induced recovery behavior of shape‐memory polymer
Authors: Lu Haibao
Published: May 2012

In this study we analyzed the phase and state transitions of shape‐memory polymers (SMPs)/solvent mixtures using the Flory–Huggins (FH) theory by extension of Vrentas and the Couchman–Karasz theory for glass transition, as well as Clausius–Clapeyron relation for melting transition. Using scaling relations of model parameters, we have obtained a theoretical prediction of state diagrams of the phase transition temperature and solvent‐induced recovery in SMPs. The inductive decrease in transition temperature is identified as the driving force for the solvent‐induced shape‐memory effect in SMPs Consequently, the thermodynamics of the polymer solution and the relaxation theory were employed to characterize the dependencies of shape recovery time on the FH parameter and the ratio of the molar volume of solute to solvent. With the estimated model parameters, we constructed the state diagram for SMP, which provides a powerful tool for design and analysis of phase transition temperatures and solvent‐induced recovery. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and characterization of novel ultraviolet‐curing polyurethane acrylate/epoxy acrylate/SiO2 hybrid materials via sol–gel reaction
Authors: Yang Zehui , Ni Aiqing , Wang Jihui
Published: May 2012

A series of ultraviolet‐curable hybrid materials was first synthesized here by sol–gel process based on tetraethoxysilane (TEOS) and polyurethane acrylate/epoxy acrylate resin. The functional groups in the hybrid materials were investigated by infrared spectroscopy (IR) analysis. The crystallinity of the hybrid materials and polymer resin was examined by X‐ray diffraction. Then, nearly uniform dispersion of SiO2 particles with the diameters ˜100 nm were revealed by field emission scanning electron micrographs. The surface morphology was scanned by atomic force microscope. And, thermal stability was measured by thermogravimetric analysis for hybrid materials produced from different mass ratio of TEOS to polymer. The results show that the hybrid material from the mass ratio of TEOS to polymer of 0.4 : 1 performed desirable optimal thermal stability and uniform microstructure which is suitable for optical fiber coating in high temperature application. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Pharmacokinetic profiling of efavirenz–emtricitabine–tenofovir fixed dose combination in pregnant and non‐pregnant rats
Authors: Nirogi Ramakrishna , Bhyrapuneni Gopinadh , Kandikere Vishwottam , Muddana Nageswararao , Saralaya Ramanatha , Komarneni Prashanth , Mudigonda Koteshwara , Mukkanti K.
Published: May 2012

During pregnancy, the disposition of various drugs is altered due to changes in physiological condition, maternal gastrointestinal absorption, gastric secretion and motility. A fixed dose combination of antiretrovirals is commonly prescribed for the treatment of HIV infection. There is a need to understand the pharmacokinetics and placental transfer of efavirenz–emtricitabine–tenofovir in fixed dose combination during pregnancy. The pharmacokinetics and placental transfer of efavirenz–emtricitabine–tenofovir fixed dose combination was evaluated in timed pregnant and non‐pregnant Sprague–Dawley rats at 30, 10, 15 mg/kg p.o., respectively. The plasma, placental tissue, amniotic fluid and fetal tissue concentrations were measured using high performance liquid chromatography combined with tandem mass spectrometric detector (LC‐MS/MS). To summarize, the pharmacokinetic profile of efavirenz remained similar in the pregnant and non‐pregnant rats. However, a considerable difference in the pharmacokinetics of emtricitabine and tenofovir was observed in pregnant and non‐pregnant rats. Efavirenz and emtricitabine showed appreciable placental, amniotic fluid and fetal exposure compared with tenofovir. The present study suggests that a profound impact on antiretroviral pharmacokinetics was observed during pregnancy and there is a need to monitor the exposure levels of each drug when administered as a fixed dose combination during pregnancy. Further studies to explore the pharmacokinetic parameters of fixed dose antiretrovirals during the preclinical stage in a timed‐pregnancy rat model are required. Such studies can help in the development of safe and effective medications with a reduced risk of perinatal transmission of HIV‐1 infection. Copyright © 2012 John Wiley & Sons, Ltd.
Curtailment in single‐arm two‐stage phase II oncology trials
Authors: Kunz Cornelia U. , Kieser Meinhard
Published: May 2012

Two‐stage designs that allow for early stopping if the treatment is ineffective are commonly used in phase II oncology trials. A limitation of current designs is that early stopping is only allowed at the end of the first stage, even if it becomes evident during the trial that a significant result is unlikely. One way to overcome this limitation is to implement stochastic curtailment procedures that enable stopping the trial whenever the conditional power is below a pre‐specified threshold θ. In this paper, we present the results for implementing curtailment rules in either only the second stage or both stages of the designs. In total, 102 scenarios with different parameter settings were investigated using conditional power thresholds θ between 0 and 1 in steps of 0.01. An increase in θ results not only in a decrease of the actual Type I error rate and power but also of the expected sample size. Therefore, a reasonable balance has to be found when selecting a specific threshold value in the planning phase of a curtailed two‐stage design. Given that the effect of curtailment highly depends on the underlying design parameters, no general recommendation for θ can be made. However, up to , the loss in power was less than 5% for all investigated scenarios while savings of up to 50% in expected sample size occurred. In general, curtailment is most appropriate when the outcome can be observed fast or when accrual is slow so that adequate information for making early and frequent decisions is available.
Nonparametric inference for the cumulative incidence function of a competing risk, with an emphasis on confidence bands in the presence of left‐truncation
Authors: Di Termini Susanna , Hieke Stefanie , Schumacher Martin , Beyersmann Jan
Published: May 2012

Motivated by a study on pregnancy outcome, a computationally simple resampling procedure for nonparametric analysis of the cumulative incidence function of a competing risk is investigated for left‐truncated data. We also modify the original procedure to producing the more desirable Greenwood‐type variance estimates. These approaches are used to construct simultaneous confidence bands of the cumulative incidence functions which is otherwise hampered by the complicated nature of the covariance process. Simulation results and a real data example are provided.
Interaction of cyproheptadine hydrochloride with human serum albumin using spectroscopy and molecular modeling methods
Authors: Jiang Hua , Chen Rongrong , Wang Hongcui , Pu Hanlin
Published: May 2012

The interaction between cyproheptadine hydrochloride (CYP) and human serum albumin (HSA) was investigated by fluorescence spectroscopy, UV–vis absorption spectroscopy, Fourier transform infrared spectroscopy (FT‐IR) and molecular modeling at a physiological pH (7.40). Fluorescence of HSA was quenched remarkably by CYP and the quenching mechanism was considered as static quenching since it formed a complex. The association constants Ka and number of binding sites n were calculated at different temperatures. According to Förster's theory of non‐radiation energy transfer, the distance r between donor (human serum albumin) and acceptor (cyproheptadine hydrochloride) was obtained. The effect of common ions on the binding constant was also investigated. The effect of CYP on the conformation of HSA was analyzed using FT‐IR, synchronous fluorescence spectroscopy and 3D fluorescence spectra. The thermodynamic parameters ΔH and ΔS were calculated to be −14.37 kJ mol−1 and 38.03 J mol−1 K−1, respectively, which suggested that hydrophobic forces played a major role in stabilizing the HSA‐CYP complex. In addition, examination of molecular modeling indicated that CYP could bind to site I of HSA and that hydrophobic interaction was the major acting force, which was in agreement with binding mode studies. Copyright © 2012 John Wiley & Sons, Ltd.
Heavy Metal Contamination in Arable Soils and Vegetables around a Sulfuric Acid Factory, China
Authors: Liu Juan , Wang Jin , Qi Jianying , Li Xiangping , Chen Yongheng , Wang Chunlin , Wu Yingjuan
Published: May 2012

This study was designed to investigate heavy metal (Tl, Pb, Cu, Zn, and Ni) contamination levels of arable soils and vegetables grown in the vicinity of a sulfuric acid factory in the Western Guangdong Province, China. Health risks associated with these metals by consumption of vegetables were assessed based on the hazard quotient (HQ). The soils show a most significant contamination of Tl, followed by Pb, Cu, Zn, and Ni. The heavy metal contents (µg/g, dry weight basis) in the edible parts of vegetables range from 5.60 to 105 for Tl, below detection limit to 227 for Pb, 5.0–30.0 for Cu, 10.0–82.9 for Zn, and 0.50–26.0 for Ni, mostly exceeding the proposed maximum permissible level in Germany or China. For the studied vegetables, the subterranean part generally bears higher contents of Tl and Zn than the aerial part, while the former has lower contents of Cu and Ni than the latter. In addition, the results reveal that Tl is the major risk contributor for the local people since its HQ values are mostly much higher than 1.0. The potential health risk of Tl pollution in the food chain and the issue of food safety should be highly concerned and kept under continued surveillance and control.
Stability of P Saturated Water Treatment Residuals under Different Levels of Dissolved Oxygen
Authors: Wang Changhui , Fei Chengbo , Pei Yuansheng
Published: May 2012

Water treatment residuals (WTRs) are effective phosphorus (P) immobilizers that have been used in constructed wetlands (CWs). In CWs, dissolved oxygen (DO) levels vary from location to location and fluctuate over time. Therefore, this work accessed the stability of P saturated ferric and alum water treatment residuals (FARs) under low (<1 mg/L), medium (2–4 mg/L), and high (5–8 mg/L) DO levels. In the experiments, which had a 40‐day duration, three stages of P release from the P saturated FARs were observed: an initial rapid P desorption stage, followed by a P re‐adsorption stage, and a P desorption balance stage. The strongest bonding between P and FARs occurred at the low DO level. A limited amount of Fe and Al was released from the P saturated FARs. Interestingly, the P in the FARs tended to transform from the Al bound P to the Fe bound P, and this transformation was stronger at lower DO levels. However, no more than 1.12% of the total P in the P saturated FARs was desorbed under any of these DO levels. Therefore, FARs can be considered as a safe P adsorption medium for CWs.
Removal of Selenium Species from Waters Using Various Surface‐Modified Natural Particles and Waste Materials
Authors: Yigit Nevzat O. , Tozum Seda
Published: May 2012

Waste red mud and natural pumice/volcanic slag particles were surface modified and their selenium adsorption from waters was investigated. Acid activation/heat treatment of original red mud (ORM) particles significantly increased their micropore and external surface area and cumulative volume of pores. Iron oxide coating of pumice/slags and acid activation of ORM decreased their pHpzc values and increased surface acidity. Selenite/selenate adsorption on iron oxide surfaces and acid activated red mud (AARM) was very fast with approximately first‐order adsorption kinetics. Iron oxide coating of pumice/slag and acid activation of ORM particles significantly enhanced their selenite and selenate uptakes. Maximum Se adsorption capacities as high as 6.3 (mg Se/g adsorbent) were obtained by AARM. The extent of selenate uptakes by the surface modified particles was generally lower than those of selenite. Due to competition among Se species and other background water matrix for iron oxide adsorption sites, reduced selenite/selenate uptakes were found in natural water compared to single solute tests. Higher Se uptakes by iron oxide surfaces were found at pH 7.5 compared to pH 8.9, due to increased electrostatic repulsion among iron oxides and Se species at higher pH. The most effective adsorbents among the tested 17 different particles for Se uptake were AARM and iron oxide coated pumice. Se concentrations less than drinking water standards (5–10 µg/L) can be achieved by these particles. These low‐cost, natural, or recyclable waste particles appear to be promising adsorbents for Se removal after their surface modification.
Atomic Layer Deposition of Copper Oxide using Copper(II) Acetylacetonate and Ozone
Authors: Alnes Mari Endresen , Monakhov Edouard , Fjellvåg Helmer , Nilsen Ola
Published: May 2012

We report on the deposition of copper oxide by atomic layer deposition (ALD) using copper acetylacetonate (Cu(acac)2) and ozone (O3) as precursors. The aim is to deposit oxides of copper as possible candidates for materials in all‐oxide photovoltaics. The present study results in ALD‐type deposition of the tenorite phase of copper(II) oxide in a temperature window of 150 °C to ca. 230 °C, with a growth rate of ∼0.038 nm per cycle. The resulting ALD characteristics, with a relatively large ALD window in deposition temperature, should be well suited for combination with additional deposition processes for the formation of complex compounds. The film thickness is studied using X‐ray reflectivity (XRR), and phase is determined by X‐ray diffraction (XRD). Surface roughness is studied using atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS) is used to investigate the chemical state of the deposited films.
A pair of transmembrane receptors essential for the retention and pigmentation of hair
Authors: Han Rong , Beppu Hideyuki , Lee Yun‐Kyoung , Georgopoulos Katia , Larue Lionel , Li En , Weiner Lorin , Brissette Janice L.
Published: May 2012

Hair follicles are simple, accessible models for many developmental processes. Here, using mutant mice, we show that Bmpr2, a known receptor for bone morphogenetic proteins (Bmps), and Acvr2a, a known receptor for Bmps and activins, are individually redundant but together essential for multiple follicular traits. When Bmpr2/Acvr2a function is reduced in cutaneous epithelium, hair follicles undergo rapid cycles of hair generation and loss. Alopecia results from a failure to terminate hair development properly, as hair clubs never form, and follicular retraction is slowed. Hair regeneration is rapid due to premature activation of new hair‐production programs. Hair shafts differentiate aberrantly due to impaired arrest of medullary‐cell proliferation. When Bmpr2/Acvr2a function is reduced in melanocytes, gray hair develops, as melanosomes differentiate but fail to grow, resulting in organelle miniaturization. We conclude that Bmpr2 and Acvr2a normally play cell‐type‐specific, necessary roles in organelle biogenesis and the shutdown of developmental programs and cell division. genesis 1–18, 2012. © 2012 Wiley Periodicals, Inc.
A conditional allele of Rspo3 reveals redundant function of R‐spondins during mouse limb development
Authors: Neufeld Stanley , Rosin Jessica M. , Ambasta Anshula , Hui Kristen , Shaneman Venessa , Crowder Ray , Vickerman Lori , Cobb John
Published: May 2012

Summary: R‐spondins are secreted ligands that bind cell surface receptors and activate Wnt/β‐catenin signaling. Human mutations and gene inactivation studies in mice have revealed a role for these four proteins (RSPO1‐4) in diverse developmental processes ranging from sex determination to limb development. Among the genes coding for R‐spondins, only inactivation of Rspo3 shows early embryonic lethality (E10.5 in mice). Therefore, a conditional allele of this gene is necessary to understand the function of R‐spondins throughout murine development. To address this need, we have produced an allele in which loxP sites flank exons 2–4 of Rspo3, allowing tissue‐specific deletion of these exons in the presence of Cre recombinase. We used these mice to investigate the role of Rspo3 during limb development and found that limbs ultimately developed normally in the absence of Rspo3 function. However, severe hindlimb truncations resulted when Rspo3 and Rspo2 mutations were combined, demonstrating redundant function of these genes. genesis 50:741–749, 2012. © 2012 Wiley Periodicals, Inc.
Bis(pyrazol‐1‐yl)methane as Non‐Chromophoric Ancillary Ligand for Charged Bis‐Cyclometalated Iridium(III) Complexes
Authors: Meng Sheng , Jung Il , Feng Jie , Scopelliti Rosario , Di Censo Davide , Grätzel Michael , Nazeeruddin M. Khaja , Baranoff Etienne
Published: May 2012

New charged cyclometalated iridium(III) complexes [Ir(ppy)2(L)](PF6) [ppy = 2‐phenylpyridine; L = bis(pyrazol‐1‐yl)methane (for 1); L = bis(3,5‐dimethylpyrazol‐1‐yl)methane (for 2)] were synthesized and their electrochemical and photophysical properties studied. These complexes with non‐π‐electron‐conjugated ancillary chelates exhibit significantly blueshifted emission relative to those of commonly used derivatives with NN ancillary ligands such as bipyridine or phenanthroline. Both X‐ray and theoretical analysis based on time‐dependent density functional theory (TD‐DFT) reveal that the binding of Ir to the bis(pyrazol‐1‐yl)methane ancillary ligand is much weaker than that to the phenylpyridine main ligand; the effect is enhanced in the excited state. As a result, the ancillary ligand does not participate in low‐energy excitations and triplet emission, and the electronic transitions are concentrated on the main chromophoric ligands. The blueshift feature is attributed to emission originating from the main cyclometalated ligands, in contrast to emitters with the NN chromophoric ancillary ligand. In addition, complex 2 exhibits a one order of magnitude higher non‐radiative decay rate than complex 1, which is attributed to the steric hindrance of the methyl groups that leads to a more loosely bound ancillary ligand.
Diphosphastannylenes: Precursors for Phosphorus–Phosphorus Coupling?
Authors: Řezníček Tomáš , Dostál Libor , Růžička Aleš , Jambor Roman
Published: May 2012

The preparation of the secondary phosphane (Ph){C6H3‐2,6‐(CH2NMe2)2}PH (1), a potentially base‐stabilized ligand, and the sterically protected carbaborane‐based phosphane (o‐CH3C2B10H10)2PH (2) is reported. Reaction of Sn{N(SiMe3)}2 with 1 gives the diphosphastannylene [(Ph){(C6H3‐2,6‐CH2NMe2)2}P]2Sn (3) in high yield. In contrast, the room‐temperature reaction of 2 with Sn{N(SiMe2)}2 does not proceed. By applying elevated temperatures, the heteroleptic amidophosphastannylene {(o‐CH3C2B10H10)2P}{(SiMe3)2N}Sn (4) was formed, instead of the expected diphosphastannylene {(o‐CH3C2B10H10)2P}2Sn. The thermal decomposition of compounds 3 and 4 was also studied. The thermal decomposition of 3 produced the new phosphorus–phosphorus‐bonded compound 5, an unprecedented 1,2‐diphosphol‐type molecule.
Reaction Mechanism of Phosphane‐Catalyzed [4+2] Annulations between α‐Alkylallenoates and Activated Alkenes: A Computational Study
Authors: Zhao Lili , Wen Mingwei , Wang Zhi‐Xiang
Published: May 2012

A DFT study has been performed to understand the [4+2] annulation reaction between α‐methylallenoate (2) and benzylidenemalononitrile (3), catalyzed by P(NMe2)3 (1). For the reaction channel to produce cyclohexene 4a as the predominated product, the catalytic cycle can be characterized by three stages: in situ generation of the 1,3‐dipole IM2 between 1 and 2 (stage I); the addition of 3 to IM2 giving six‐membered‐ring intermediate IM8 (stage II); and catalyst 1 liberation from IM8 to produce 4a (stage III). For stage II, the pathway through direct [4+2] addition, followed by [1,3]‐H transfer, enabled by the alkene carbon bearing nitrile groups, is feasible, but less favorable than the [3+2] addition pathway followed by water‐aided [1,3]‐H transfer. The pathway leading to the regioisomer of 4a (i.e., 4b) is substantially less favorable, which accounts for the exclusive regioselectivity (4a/4b = 100:0) of the reaction. The [4+2] annulations are different from the conventional [3+2] cycloadditions of allenoates and activated alkenes. For the latter, a trace of water was demonstrated to be critical, even though the reactions are carried out in so‐called “anhydrous” solvents, because water is the only available hydrogen transfer mediator. In other words, the traditional [3+2] cycloadditions would not occur if the solvent were absolutely free of water. In contrast, [4+2] annulations can take place, even though water is completely absent, because the carbon (CCN of alkene 3) bearing the nitrile groups can serve as the hydrogen transfer mediator. The substitution effects of alkenes on the addition step of alkenes to IM2 have been further investigated.
Efficient Method for Varying the Anions in Quaternary Onium Halides
Authors: Jeon Jong Yeob , Varghese Jobi Kodiyan , Park Ji Hae , Lee Suck‐Hyun , Lee Bun Yeoul
Published: May 2012

Quaternary onium salts of halides can be efficiently converted into the corresponding quaternary onium salts of various anions [NO3–, BF4–, PF6–, CF3SO3–, CH3SO3–, ClO4–, p‐CH3C6H4SO3–, CF3CO2–, 2,4‐(NO2)2C6H3O–] by treating the onium halide with trimethyl phosphate under neat condition in the presence of an equivalent amount of conjugate acid of the desired anion.
Modelling decomposition and fire behaviour of small samples of a glass‐fibre‐reinforced polyester/balsa‐cored sandwich material
Authors: Marquis Damien M. , Pavageau Michel , Guillaume Eric , Chivas‐Joly Carine
Published: May 2012

This publication presents the experimental and numerical methods to model the devolatilization process of a glass‐fibre‐reinforced polyester/balsa‐cored sandwich material on small scale. The fundamental modelling of the source term in pyrolysis‐based fire simulations requires as input data the thermochemical properties of solid fuel and the kinetic parameters of the devolatilization process. First, the thermal decomposition of both elements composing the sandwich structure was studied by thermogravimetry coupled with gas analysis, in air and pure nitrogen atmospheres at several heating rates, in order to define a comprehensive multi‐step reaction pathway. A differential equation system is defined to model these decomposition processes. The kinetic parameters were then estimated by solving the system of equations by an inverse problem. Second, the fire behaviour of each element was studied separately and then combined in the sandwich structure on the cone calorimeter. In addition, numerical simulations with Fire Dynamics Simulator were performed to gradually assess the ability of the model(s) to reproduce each element composing the sandwich structure. Numerical and experimental results are compared and then discussed. Overall, the model provides a good agreement with the experimental data and encourages to model higher scales. Copyright © 2012 John Wiley & Sons, Ltd.
Decreased hospital stay and significant cost savings after routine use of prophylactic gastrostomy for high‐risk patients with head and neck cancer receiving chemoradiotherapy at a tertiary cancer institution
Authors: Hughes Brett G. M. , Jain Vikram K. , Brown Teresa , Spurgin Ann‐Louise , Hartnett Gemma , Keller Jacqui , Tripcony Lee , Appleyard Mark , Hodge Robert
Published: May 2012

Background

Evidence‐based nutritional and swallowing guidelines were developed to identify patients at high risk of developing malnutrition during chemoradiation for head and neck cancer. These guidelines recommended a prophylactic gastrostomy and were actively implemented at our institution in January 2007. This study assesses the effect of this policy change on patient outcomes.

Methods

This retrospective cohort study was carried out for the years before (2005) and after (2007) implementation of these guidelines.

Results

In all, 165 patients were treated with radical chemoradiation for head and neck cancer at our institution in the years 2005 and 2007. Gastrostomy tube complications were low. Patients in 2007 had significantly fewer hospital admissions, unexpected admissions, and a shorter mean duration of hospital stay in comparison with those in 2005.

Conclusions

Prophylactic gastrostomy tubes in patients with high‐risk head and neck cancer resulted in a significant decrease in hospital admissions and length of stay, and led to increased bed availability. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Head and neck squamous cell carcinoma: Differentiation of histologic grade with standard‐ and high‐b‐value diffusion‐weighted MRI
Authors: Yun Tae Jin , Kim Ji‐hoon , Kim Kwang Hyun , Sohn Chul‐Ho , Park Sun‐Won
Published: May 2012

Background

The correlation between the histologic grades and the apparent diffusion coefficient (ADC) in head and neck squamous cell carcinomas (HNSCCs) remains unclear. This study aimed to evaluate the potential of diffusion‐weighted MRI (DW‐MRI) at both standard and high b values to differentiate the histologic grades of HNSCC.

Methods

In all, 54 consecutive patients with HNSCCs (34 well‐differentiated, 10 moderately differentiated, and 10 poorly differentiated) performed DW‐MRIs at both b = 1000 and 2000 s/mm2 prior to biopsy or surgery. The ADC values were compared among the different histologic grades.

Results

The ADC values of well‐differentiated and poorly differentiated HNSCC were significantly different at both b values (p < .001 in both). However, significant difference between moderately differentiated and poorly differentiated HNSCC was revealed at only b = 2000 s/mm2 (p = .014).

Conclusions

DW‐MRIs at standard and high b values are helpful for differentiating histologic grades in HNSCC with better differentiation at a high b‐value. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Prospective study of prognostic value of Raf kinase inhibitory protein and pretreatment plasma Epstein–Barr virus DNA for distant metastasis in locoregionally advanced nasopharyngeal carcinoma
Authors: Li Si‐Wei , Wang Hua , Xiang Yan‐Qun , Zhang Hai‐bo , Lv Xing , Xia Wei‐Xiong , Zeng Mu‐Sheng , Mai Hai‐Qiang , Hong Ming‐Huang , Guo Xiang
Published: May 2012

Background

The purpose of this prospective study was to investigate the predictive significance of Raf kinase inhibitory protein (RKIP) in locoregionally advanced nasopharyngeal carcinoma (NPC) and its effect on distant metastasis.

Methods

The usual immunohistochemical stainings were performed to detect RKIP expression of cancer tissues from 210 patients with advanced NPC. After DNA samples from pretreatment plasma from these patients were extracted, real‐time polymerase chain reaction (PCR) was performed to quantitatively analyze plasma Epstein–Barr virus (EBV) DNA.

Results

RKIP expression was significantly different for different N classifications and WHO pathologic grades, respectively (p < .05). Cox regression confirmed RKIP and EBV DNA were independent prognostic markers for 5‐year distant metastasis‐free survival (DMFS). In the high RKIP expression group, chemotherapy had a positive effect on improved DMFS, but not in the low RKIP expression group.

Conclusions

RKIP could be identified as an independent prognostic factor on DMFS. For each combined treatment modality, the different impact of chemotherapy on distant metastasis might be related to the RKIP expression level. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Conventional transoral surgery for stage I–II squamous cell carcinoma of the tonsillar region
Authors: Laccourreye Ollivier , Malinvaud David , Alzahrani Hatem , Ménard Madeleine , Garcia Dominique , Bonfils Pierre , Holsinger F. Christopher
Published: May 2012

Background

The purpose of this study was to review the results of conventional transoral resection and neck dissection for stage I to II squamous carcinoma of the tonsillar region.

Methods

We conducted a retrospective review of 65 patients (stage I, 21 patients; stage II, 44 patients). Induction chemotherapy and postoperative radiation therapy (RT) were administered in 76.9% and 12.3%, respectively, of these cases.

Results

The postoperative course was uneventful in 96.9% of patients. Five‐year actuarial estimates for local recurrence, nodal recurrence, distant metastasis, and survival were 0% to 7.6%, 0% to 7.8%, 0% to 7.3%, and 70.8% to 71.5% for patients with T1 to T2 carcinoma, respectively. Contralateral and retropharyngeal recurrence occurred in only 1 patient.

Conclusion

Conventional transoral resection with ipsilateral neck dissection provides an alternative approach for patients with stage I to II squamous cell carcinoma (SCC) of the tonsillar region. A primary surgical approach spares the use of radiotherapy to eliminate late effects and to permit its use for subsequent management of metachronous head and neck second primary cancer. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Impact of disease severity on healthcare costs in patients with chronic hepatitis C (CHC) virus infection
Authors: Gordon Stuart C. , Pockros Paul J. , Terrault Norah A. , Hoop Robert S. , Buikema Ami , Nerenz David , Hamzeh Fayez M.
Published: May 2012

Hepatitis C virus (HCV) infection increases total healthcare costs but the effect of the severity of liver disease associated with chronic hepatitis C (CHC) on healthcare costs has not been well studied. We analyzed the demographics, healthcare utilization, and healthcare costs of CHC patients in a large U.S. private insurance database (January, 2002 to August, 2010), with at least 1 year of baseline enrollment and 30 days of continuous follow-up. Patients were stratified by liver disease severity: noncirrhotic liver disease (NCD), compensated cirrhosis (CC), and endstage liver disease (ESLD), as defined by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9) codes. Mean all-cause and HCV-related healthcare costs per-patient-per-month (PPPM) during follow-up (mean 634 days) are reported in 2010 U.S.$ from the payer's perspective. A total of 53,796 patients with CHC were included (NCD: 41,858 [78%]; CC: 3,718 [7%]; and ESLD: 8,220 [15%]). Mean all-cause PPPM healthcare costs were 32% and 247% higher for patients with CC and ESLD compared to those with NCD ($1,870 and $4,931 versus $1,420;

P

< 0.001) and were independent of age or comorbid conditions. Pharmacy, ambulatory, and inpatient care collectively accounted for 90% of NCD costs and 93% of CC and ESLD costs. The largest cost components were inpatient costs for those with ESLD (56%) and ambulatory costs for those with CC and NCD (37% and 36%, respectively). Overall, 56% of costs were HCV-related and this proportion increased with severity (46%, 57%, and 71% for patients with NCD, CC, and ESLD, respectively).

Conclusion :

The direct healthcare costs associated with CHC are high, increase in association with the progression of liver disease, and are highest in those with ESLD.
Hepatitis C virus-induced up-regulation of microRNA-155 promotes hepatocarcinogenesis by activating Wnt signaling
Authors: Zhang Yiliang , Wei Wei , Cheng Na , Wang Kaihui , Li Bin , Jiang Xiaoqing , Sun Shuhan
Published: May 2012

Hepatitis C virus (HCV) infection usually induces chronic hepatic inflammation, which favors the initiation and progression of hepatocellular carcinoma (HCC). Moreover, microRNA-155 (miR-155) plays an important role in regulating both inflammation and tumorigenesis. However, little is known about whether and how miR-155 provides the link between inflammation and cancer. In this study we found that miR-155 levels were markedly increased in patients infected with HCV. MiR-155 transcription was regulated by nuclear factor kappa B (NF-κB), and p300 increased NF-κB-dependent miR-155 expression. The overexpression of miR-155 significantly inhibited hepatocyte apoptosis and promoted cell proliferation, whereas miR-155 inhibition induced G0/G1 arrest. Up-regulated miR-155 resulted in nuclear accumulation of β-catenin and a concomitant increase in cyclin D1, c-myc, and survivin. Gain-of-function and loss-of-function studies demonstrated that miR-155 promoted hepatocyte proliferation and tumorigenesis by increasing Wnt signaling

in vitro

and

in vivo

, and DKK1 (Wnt pathway inhibitor) overexpression inhibited the biological role of miR-155 in hepatocytes. Finally, adenomatous polyposis coli (APC), which negatively regulates Wnt signaling, was identified as the direct and functional target of miR-155.

Conclusion :

HCV-induced miR-155 expression promotes hepatocyte proliferation and tumorigenesis by activating Wnt signaling. The present study provides a better understanding of the relationship between inflammation and tumorigenesis, and thus may be helpful in the development of effective diagnosis and treatment strategies against HCV-HCC.
Rare inborn errors associated with chronic hepatitis B virus infection
Authors: Zhao Qiang , Peng Liang , Huang Weijun , Li Qibin , Pei Yuanyuan , Yuan Ping , Zheng Lingyan , Zhang Yongling , Deng Jia , Zhong Cheng , Hu Bin , Ding Hongke , Fang Wei , Li Ru , Liao Qijun , Lin Chaoshuang , Deng Weiping , Yan Huijun , Hou Jinghui , Wu Qiuliang , Xu Tingting , Liu Jinsong , Hu Longbo , Peng Tao , Chen Suqing , Lai Kar N. , Yuen Man-Fung , Wang Yue , Maini Mala K. , Li Caixia , Li Miaoxin , Wang Jian , Zhang Xiuqing , Sham Pak-Chung , Wang Jun , Gao Zhi-Liang , Wang Yiming
Published: May 2012

Chronic hepatitis B (CHB) is a major global health issue. The role of rare genetic variants in CHB has not been elucidated. We aimed to identify rare allelic variants predisposing to CHB. We performed exome sequencing in 50 CHB patients who had no identifiable risk factors for CHB and 40 controls who were healthy and hepatitis B surface antibody-positive, but had never received hepatitis B vaccination. We selected six rare variant alleles and followed up their association with disease status by Sanger sequencing in a case-control study comprising 1,728 CHB patients and 1,636 healthy controls. The latter had either not been immunized with hepatitis B vaccine or had uncertain vaccination status. Our results showed that

transmembrane protein 2

p.Ser1254Asn,

interferon alpha 2

p.Ala120Thr, its regulator

NLR family member X1

p.Arg707Cys, and

complement component 2

p.Glu318Asp were associated with CHB, with

P

values of <1.0 × 10−7, 2.76 × 10−5, 5.08 × 10−5, 2.78 × 10−4 and odds ratios (ORs) of 2.45, 4.08, 2.34, and 1.97, respectively. The combined

P

value was <2.0 × 10−16. As there has been no indication of immunological functions for the associated gene,

transmembrane protein 2

, we further studied its expression by immunohistochemistry, real-time polymerase chain reaction, and western blotting. Our results showed that it was strongly expressed by healthy hepatocytes, but its expression was reduced in liver tissues with CHB, hepatitis B viral (HBV) genome-containing HepG2.2.15 cells, as compared with healthy liver tissues and non-HBV genome-containing HepG2 cells (

P

= 0.022 and 0.0036, respectively).

Conclusion :

We identified four missense mutations associated with CHB, our results providing evidence for rare inborn genetic defects that contribute to increased host susceptibility to CHB.
The centrosomal protein tax1 binding protein 2 is a novel tumor suppressor in hepatocellular carcinoma regulated by cyclin-dependent kinase 2
Authors: Lai Wai-Lung , Hung Wing-Yan , Wong Leo Lap-Yan , Zhou Yuan , Leong Veronica Yee-Law , Lee Joyce Man-Fong , Ng Irene Oi-Lin , Jin Dong-Yan , Ching Yick-Pang
Published: May 2012

Deregulation of cellular-signaling pathways by the inactivation of tumor-suppressor genes is one of the major causes of hepatocellular carcinoma (HCC). In this study, we identified Tax1 binding protein 2 (TAX1BP2) as a novel tumor-suppressor gene in HCC. TAX1BP2 transcript was frequently underexpressed (42.2% with T/NT <0.5;

P

< 0.03) in HCCs, and underexpression of TAX1BP2 was associated with poorer overall survival rates in patients after surgical resection. An effector domain (ED) for TAX1BP2 tumor-suppressor activity was mapped to the amino-acid residues 267-756. Transient or stable expression of either full-length or ED of TAX1BP2 significantly suppressed HCC cell tumorigenicity through the activation of the p38/p53/p21 pathway. In contrast, silencing of TAX1BP2 by short interfering RNA remarkably suppressed the activation of the p38/p53/p21 pathway. Finally, phosphorylation of TAX1BP2 at serine-763 by cyclin-dependent kinase (CDK)2 abolished the TAX1BP2-mediated p38 activation and tumor-suppressive activity, indicating that TAX1BP2 can adapt CDK2 signaling to the p38/p53/p21 pathway.

Conclusion :

Taken together, our data provide the first evidence that TAX1BP2 is a CDK2-regulated tumor-suppressor gene in HCC and is a novel activator of the p38/p53/p21 pathway.
Prenatal stress changes learning strategies in adulthood
Authors: Schwabe Lars , Bohbot Veronique D. , Wolf Oliver T.
Published: May 2012

It is well known that stressful experiences may shape hippocampus‐dependent learning and memory processes. However, although most studies focused on the impact of stress at the time of learning or memory testing, very little is known about how stress during critical periods of brain development affects learning and memory later in life. In this study, we asked whether prenatal stress exposure may influence the engagement of hippocampus‐dependent spatial learning strategies and caudate nucleus‐dependent response learning strategies in later life. To this end, we tested healthy participants whose mothers had experienced major negative life events during their pregnancy in a virtual navigation task that can be solved by spatial and response strategies. We found that young adults with prenatal stress used rigid response learning strategies more often than flexible spatial learning strategies compared with participants whose mothers did not experience major negative life events during pregnancy. Individual differences in acute or chronic stress do not account for these findings. Our data suggest that the engagement of hippocampal and nonhippocampal learning strategies may be influenced by stress very early in life. © 2012 Wiley Periodicals, Inc.
Isolated central nervous system relapses in primary mediastinal large B‐cell lymphoma after CHOP‐like chemotherapy with or without Rituximab
Authors: Papageorgiou Sotirios G. , Diamantopoulos Panayiotis , Levidou Georgia , Angelopoulou Maria K. , Economopoulou Panagiota , Efthimiou Anna , Constantinou Nikos , Katsigiannis Andreas , Korkolopoulou Penelope , Pappa Vassiliki , Economopoulou Christina , Georgiou George , Dimou Maria , Tsirigotis Panagiotis , Kyrtsonis Marie‐Christine , Kotsianidis Ioannis , Kalpadakis Christina , Dimopoulos Meletios‐Athanassios , Beris Photis , Meletis John , Pangalis Gerassimos A. , Dervenoulas John , Panayiotidis Panayiotis , Vassilakopoulos Theodoros P.
Published: May 2012

Central nervous system (CNS) involvement in patients with primary mediastinal large B‐cell (PMLBCL) lymphoma is a rare event, occurring in approximately 6% of patients, on the basis of the review of the literature prior to induction of Rituximab. The aim of this retrospective study was to describe the incidence of CNS relapse among 100 consecutive patients with PMLBCL who were treated with R‐CHOP ± RT in comparison to patients treated with CHOP ± RT (n = 45) in 11 hospitals in Greece. Two patients experienced a CNS relapse, representing an overall frequency of 2.0% in R‐CHOP treated patients and a 2‐year actuarial incidence of 2.3%. Both patients had isolated CNS relapses. The incidence of CNS relapse after CHOP without Rituximab was 2/45 (4.4%) for a 2‐year actuarial incidence of 7.5% (p = 0.29). Again, both patients had isolated CNS relapses. Parenchymal‐only localizations accounted for 3/4 cases. Risk factors for CNS involvement could include leukocytosis, poor performance status and higher age‐adjusted International Prognostic Index, although their impact was weakened by competing risk survival analysis. Both patients relapsing after R‐CHOP required CNS radiotherapy to achieve a complete remission and be forwarded to high‐dose therapy and autologous stem cell transplantation: They are both alive and disease‐free 18 and 23 months after CNS relapse. Both cases relapsing after CHOP without Rituximab were salvaged by CNS radiotherapy (one also received intrathecal chemotherapy) entering long‐term remissions. In conclusion, CNS relapses are rare in PMLBCL tending to be isolated in the CNS, probably reflecting the persistence of latent CNS disease than dissemination of resistant disease. The impact of Rituximab in reducing CNS relapses remains unknown. Established risk factors for CNS involvement in aggressive lymphomas may not be helpful in assessing the risk of CNS recurrence in this disease. Routine CNS prophylaxis is not probably required in PMLBCL. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of bare surface soil moisture from combined temporal evolution of land surface temperature and net surface shortwave radiation
Authors: Zhao Wei , Li Zhao‐Liang , Wu Hua , Tang Bo‐Hui , Zhang Xiaoyu , Song Xiaoning , Zhou Guoqing
Published: May 2012

Land surface soil moisture (SSM) is an important variable for hydrological, ecological, and meteorological applications. A multi‐linear model has recently been proposed to determine the SSM content from the combined diurnal evolution of both land surface temperature (LST) and net surface shortwave radiation (NSSR) with the parameters TN (the LST mid‐morning rising rate divided by the NSSR rising rate during the same period) and td (the time of daily maximum temperature). However, in addition to the problem that all the coefficients of the multi‐linear model depend on the atmospheric conditions, the model also suffers from the problems of the nonlinearity of TN as a function of the SSM content and the uncertainty of determining the td from the diurnal evolution of the LST. To address these problems, a modified multi‐linear model was developed using the logarithm of TN and normalizing td by the mid‐morning temperature difference instead of using the TN and td. Except for the constant term, the coefficients of all other variables in the modified multi‐linear model proved to be independent of the atmospheric conditions. Using the relevant simulation data, results from the modified multi‐linear model show that the SSM content can be determined with a root mean square error (RMSE) of 0.030m3/m3, provided that the constant term is known or estimated day to day. The validation of the model was conducted using the field measurements at the Langfang site in 2008 in China. A higher correlation is achieved (coefficient of determination: R2 = 0.624, RMSE = 0.107m3/m3) between the measured SSM content and the SSM content estimated using the modified multi‐linear model with the coefficients determined from the simulation data. Another experiment is also conducted to estimate the SSM content using the modified model with the constant term calibrated each day by one‐spot measurements at the site. The estimation result has a relatively larger error (RMSE = 0.125m3/m3). Additionally, the uncertainty of the determination of the coefficients is analysed using the field measurements, and the results indicate that the SSM content obtained using the modified model accurately characterizes the surface soil moisture condition. Copyright © 2012 John Wiley & Sons, Ltd.
The APTIMA HPV assay versus the hybrid capture 2 test in triage of women with ASC‐US or LSIL cervical cytology: A meta‐analysis of the diagnostic accuracy
Authors: Arbyn Marc , Roelens Jolien , Cuschieri Kate , Cuzick Jack , Szarewski Ann , Ratnam Sam , Reuschenbach Miriam , Belinson Suzanne , Belinson Jerome L. , Monsonego Joseph
Published: May 2012

Testing for DNA of 13 high‐risk HPV types with the Hybrid Capture 2 (HC2) test has consistently been shown to perform better in triage of women with cervical cytology results showing atypical squamous cells of undetermined significance (ASC‐US) but often not in triage of low‐grade squamous intraepithelial lesions (LSIL) detected in cervical cancer screening. In a meta‐analysis, we compared the accuracy of the APTIMA HPV test, which identifies RNA of 14 high‐risk HPV types, to HC2 for the triage of women with ASC‐US or LSIL. Literature search‐targeted studies where the accuracy of APTIMA HPV and HC2 for detection of underlying CIN2/3+ was assessed concomitantly including verification of all cases of ASC‐US and LSIL. HSROC (Hierarchical Summary ROC) curve regression was used to compute the pooled absolute and relative sensitivity and specificity. Eight studies, comprising 1,839 ASC‐US and 1,887 LSIL cases, were retrieved. The pooled sensitivity and specificity of APTIMA to triage ASC‐US to detect underlying CIN3 or worse was 96.2% (95% CI = 91.7–98.3%) and 54.9% (95% CI = 43.5–65.9%), respectively. APTIMA and HC2 showed similar pooled sensitivity; however, the specificity of the former was significantly higher (ratio: 1.19; 95% CI = 1.08–1.31 for CIN2+). The pooled sensitivity and specificity of APTIMA to triage LSIL were 96.7% (95% CI = 91.4–98.9%) and 38.7% (95% CI = 30.5–47.6%) for CIN3+. APTIMA was as sensitive as HC2 but more specific (ratio: 1.35; 95% CI = 1.11–1.66). Results were similar for detection of CIN2 or worse. In both triage of ASC‐US and LSIL, APTIMA is as sensitive but more specific than HC2 for detecting cervical precancer.