bluuebunny/crossref_metadata_2025 huggingface dataset:
Joint generalized models for multidimensional outcomes: A case study of neuroscience data from multimodalities
Authors: Wang Xiao‐Feng
Published: April 2012

This paper is motivated from the analysis of neuroscience data in a study of neural and muscular mechanisms of muscle fatigue. Multidimensional outcomes of different natures were obtained simultaneously from multiple modalities, including handgrip force, electromyography (EMG), and functional magnetic resonance imaging (fMRI). We first study individual modeling of the univariate response depending on its nature. A mixed‐effects beta model and a mixed‐effects simplex model are compared for modeling the force/EMG percentages. A mixed‐effects negative‐binomial model is proposed for modeling the fMRI counts. Then, I present a joint modeling approach to model the multidimensional outcomes together, which allows us to not only estimate the covariate effects but also to evaluate the strength of association among the multiple responses from different modalities. A simulation study is conducted to quantify the possible benefits by the new approaches in finite sample situations. Finally, the analysis of the fatigue data is illustrated with the use of the proposed methods.
Accurate mean comparisons for paired samples with missing data: An application to a smoking‐cessation trial
Authors: Xu Jin , Harrar Solomon W.
Published: April 2012

In this paper, we consider mean comparisons for paired samples in which a certain portion of the observations are missing. This type of data commonly arises in medical researches where the outcomes are assessed at two time points after the application of treatments. New methods for statistical inference are proposed by making finiteness correction based on asymptotic expansions of some intuitive statistics. The comparison methods naturally extend to the two‐group case after some suitable manipulations. Simulation study is carried out to demonstrate the numerical accuracy of the proposed methods. Data from a smoking‐cessation trial are used to illustrate the application of the methods.
Flow injection chemiluminescence determination of 2‐methoxyestradiol based on inhibition of luminol‐potassium ferricyanide reaction
Authors: Jin Jianwen , Yao Hanchun , Chen Zheng , Pang Li , Du Bin
Published: April 2012

A novel flow‐injection chemiluminescence (FI‐CL) method is described for the determination of 2‐methoxyestradiol (2‐ME). The method is based on the inhibitory effect of 2‐ME on the CL reaction of luminol and potassium ferricyanide in alkaline solution. Under optimal conditions, net CL intensity was proportional to 2‐ME concentration in synthetic and mouse plasma samples. Corresponding linear regression equations were 8.0 x 10‐9‐1.0 x 10‐7g/mL for synthetic samples and 2.0 x 10‐9‐1.0 x 10‐7g/mL for plasma samples. Detection limit for synthetic samples and limits for quantification of plasma samples were 8.4 x 10‐10g/mL (3σ) for synthetic samples and 4.0 x 10‐9g/mL for mouse samples. A complete analysis was performed for 60 s, including washing and sampling, resulting in a throughput of ≈ 60/h. The proposed method was applied for the determination of 2‐ME in synthetic and mouse plasma samples. Percentage recoveries were 101.0‐102.8% and 98.0‐105.0%, respectively. A possible mechanism responsible for CL reaction is proposed. Copyright © 2012 John Wiley & Sons, Ltd.
Resection margin involvement and tumour origin in pancreatic head cancer
Authors: Verbeke C S , Gladhaug I P
Published: April 2012

Background

Assessment of the origin of adenocarcinoma in pancreatoduodenectomy specimens (pancreatic, ampullary or biliary) and resection margin status is not performed in a consistent manner in different centres. The aim of this review was to identify the impact of such variations on patient outcome.

Methods

A systematic literature search for articles on pancreatic, ampullary, distal bile duct and periampullary cancer was performed, with special attention to data on resection margin status, pathological examination and outcome.

Results

The frequent reclassification of tumour origin following slide review, and the wide variation in published incidence of pancreatic (33–89 per cent), ampullary (5–42 per cent) and distal bile duct (5–38 per cent) cancers indicate that the histopathological distinction between the three cancer groups is less accurate than generally believed. Recent studies have shown that the wide range of rates of microscopic margin involvement (R1) in pancreatoduodenectomy specimens (18–85, 0–27 and 0–72 per cent respectively for pancreatic, ampullary and distal bile duct cancers) is mainly caused by differences in pathological assessment rather than surgical practice and patient selection. As a consequence of the existing inconsistency in reporting of these data items, the clinical significance of microscopic margin involvement in each of the three cancer groups remains unclear.

Conclusion

Inaccurate and inconsistent distinction between pancreatic, ampullary and distal bile duct cancer, combined with inaccuracies in resection margin assessment, results in obfuscation of key clinicopathological data. Specimen dissection technique plays a key role in the quality of the assessment of both tumour origin and margin status. Unless the pathological examination is meticulous and standardized, comparison of results between centres and observations in multicentre trials will remain of limited value.
Mini‐scale bioprocessing systems for highly parallel animal cell cultures
Authors: Kim Beum Jun , Diao Jinpian , Shuler Michael L.
Published: April 2012

Animal cells have been used extensively in therapeutic protein production. The growth of animal cells and the expression of therapeutic proteins are highly dependent on the culturing environments. A large number of experimental permutations need to be explored to identify the optimal culturing conditions. Miniaturized bioreactors are well suited for such tasks as they offer high‐throughput parallel operation and reduce cost of reagents. They can also be automated and be coupled to downstream analytical units for online measurements of culture products. This review summarizes the current status of miniaturized bioreactors for animal cell cultivation based on the design categories: microtiter plates, flasks, stirred tank reactors, novel designs with active mixing, and microfluidic cell culture devices. We compare cell density and product titer, for batch or fed‐batch modes for each system. Monitoring/controlling devices for engineering parameters such as pH, dissolved oxygen, and dissolved carbon dioxide, which could be applied to such systems, are summarized. Finally, mini‐scale tools for process performance evaluation for animal cell cultures are discussed: total cell density, cell viability, product titer and quality, substrates, and metabolites profiles. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Direct Crystallographic Observation of Catalytic Reactions inside the Pores of a Flexible Coordination Polymer
Authors: Das Raj Kumar , Aijaz Arshad , Sharma Manish K. , Lama Prem , Bharadwaj Parimal K.
Published: April 2012

A new flexible porous coordination polymer (PCP), {[Gd2(L)3(dmf)4]⋅4 DMF⋅3 H2O}n (1), was synthesized under solvothermal condition by reacting [Gd(NO3)3]⋅6 H2O with the ligand 2,6,2′,6′‐tetranitro‐biphenyl‐4,4′‐dicarboxylic acid (H2L). Compound 1 had a 3D coordination polymeric structure with two types of 1D channels (A and B) that were occupied by DMF and water molecules. When crystals of 1 were separately exposed to vapors of various aromatic aldehydes, either the lattice or both the lattice and metal‐bound solvent molecules were replaced by aldehyde molecules. The aldehyde molecules inside the pores spontaneously underwent cyanosilylation and Knoevenagel condensation reactions upon exposure to vapors of trimethylsilyl cyanide and malononitrile, respectively. These reactions took place at ambient temperature and pressure. Moreover, both the reactants and the products translocated from one cavity to another. The products that occupied the cavity were expunged upon exposure to the vapors of an aldehyde. Because crystallinity was maintained during these chemical transformations, direct crystallographic observation was possible. Herein, we showed that confinement of the reactants inside the void spaces of the PCP led to the products; we also assessed catalytic activities of this PCP in bulk quantities.
Evaluation of “click” binaphthyl chiral stationary phases by liquid chromatography
Authors: Yu Hui , Yin Chenghua , Jia Cunyu , Jin Yu , Ke Yanxiong , Liang Xinmiao
Published: April 2012

Two “click” binaphthyl chiral stationary phases were synthesized and evaluated by liquid chromatography. Their structures incorporate S‐(−)‐1,1'‐binaphthyl moiety as the chiral selector and 1,2,3‐triazole ring as the spacer. These chiral stationary phases (CSPs) allowed the efficient resolution for a wide range of racemic BINOL derivatives, particularly for nonpolar diether derivatives and 3‐phenyl indolin‐2‐one analogs. The chromatographic data showed that the π–π interaction was crucial for enantiorecognition of these CSPs. Loss of enantioselectivity observed on CSP3, which are lacking the triazole ring linkage, indicated that the triazole ring linkage took part in the enantioseparation process, although it was remote from the chiral selector of the CSP. The substitution of the phenyl group at 6 and 6' positions can significantly improve the separation ability of the CSP. The chiral recognition mechanism was also investigated by tracking the elution orders and studying the thermodynamic parameters. Chirality 24:391–399, 2012. Copyright © 2012 Wiley Periodicals, Inc.
The functional duality of HoxB4 in hematopoietic reconstituting cells
Authors: Kaplan David , Kaye Nicholas , Liu Fangfang , Fu Pingfu , Margevicius Seunghee , Meyerson Howard J. , Lazarus Hillard M.
Published: April 2012

Transplantation of CD34+ hematopoietic reconstituting cells (HRC) is an important treatment modality. The cells needed for clinical hematopoietic reconstitution after myeloablation most commonly derive from bone marrow which have been mobilized into the peripheral blood. The number of CD34+ cells in mobilized blood samples is used to indicate the appropriateness of transplantation although it does not evaluate the two necessary functions for successful transplantation: long‐term reconstitution mediated by cells with self‐renewing proliferation and short‐term hematopoietic differentiation mediated by progenitor cells. Using a novel high‐resolution immunophenotyping technology on a flow cytometric platform, we have assessed uniformly mobilized CD34+ cells for expression levels of 16 molecules previously associated with HRC function and sought correlations of these expression data with functional short‐term assays for colony formation that do predict successful transplantation. We found that colony‐forming units were significantly correlated with HoxB4 expression, which was explained by the number of CD34+ cells in the samples. However, analysis of colony‐forming units normalized to the CD34+ cell count revealed a significant negative correlation with HoxB4 expression. Thus, increased levels of HoxB4 enhance CD34+ cell number via self‐renewing expansion but concomitantly depreciate the capacity for short‐term differentiation per cell. Our findings demonstrate the translation of experimental findings into a clinical setting and suggest that the expression level of HoxB4 in CD34+ cells can be used as a measure of a sample's appropriateness for transplantation. © 2012 International Society for Advancement of Cytometry
A novel flow‐injection chemiluminescence method for determination of andrographolide in andrographis tablets
Authors: Jiang Zejun , Hao Zaibin , Wu Qiong , Li Yang , Liu Hongyan , Yan Li
Published: April 2012

A novel method for determination of andrographolide using flow‐injection chemiluminescence (FI‐CL) analysis is described in this paper. The chemiluminescence intensity of the solution was enhanced proportionally while the concentration of andrographolide increased. Under the selected experimental conditions, the calibration curve of andrographolide was linear within the range of 0.2 to 35.0 µg mL−1 with a linear equation of ΔI = 23.391x (µg mL−1) + 34.191, R2 = 0.9965. The detection limit (3σ) was 7.42 × 10−2 µg mL−1. At the case of continuous determination of andrographolide, the relative standard deviation (RSD, n = 11) was less than 1.82%. The method has been successfully applied to the determination of andrographis tablets with satisfactory results. Copyright © 2012 John Wiley & Sons, Ltd.
Electrochemical Synthesis and Characterization of Semiconducting Ni(TCNQF4)2(H2O)2 (TCNQF4 = 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane)
Authors: Le Thanh Hai , Nafady Ayman , Lu Jinzhen , Peleckis Germanas , Bond Alan M. , Martin Lisandra L.
Published: April 2012

An electrochemical technique has been used to synthesize Ni(TCNQF4)2(H2O)2 (TCNQF4 = 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane). The method involves the reduction of solid TCNQF4 immobilized on an electrode surface in contact with Ni2+ (aq.)‐containing electrolyte. The electrochemically irreversible, but chemically reversiblesolid–solid TCNQF4/Ni(TCNQF4)2(H2O)2 interconversion process is governed by nucleation and growth kinetics and is represented by the overall reaction: 2TCNQF4 (s, electrode) + Ni2+ (aq.) + 2H2O + 2e [rlhar2] Ni(TCNQF4)2(H2O)2 (s, electrode). Thus, the formation of Ni(TCNQF4)2(H2O)2 involves the one‐electron reduction of TCNQF4 to [TCNQF4]·– coupled with an ingress of Ni2+ (aq.) from the aqueous electrolyte, while the reverse scan represents the oxidation of [TCNQF4]·– to TCNQF4 coupled with the egress of Ni2+ (aq.). Cyclic voltammograms for the TCNQF4/Ni(TCNQF4)2(H2O)2 solid–solid phase transformation are independent of the electrode material and the identity of the Ni2+ (aq.) counteranion but are strongly dependent on the concentration of Ni2+ (aq.) and the scan rate. UV/Vis, infrared, and Raman spectra confirm the presence of [TCNQF4]·– in the newly synthesized material. The composition of Ni(TCNQF4)2(H2O)2 was deduced from thermogravimetric and elemental analyses. Scanning electron microscopic images of Ni(TCNQF4)2(H2O)2 electrocrystallized onto the surface of an indium tin oxide electrode show a thin film morphology. Magnetic and conductivity data demonstrate that the complex behaves as a classical paramagnet and is a typical semiconductor with a band gap close to that of an insulator.
Attempts Directed towards the Synthesis of Intermediate (Aryne)chromium Complexes from Aryl Triflates and from (Haloarene)chromium Complexes
Authors: Werner Georg , Butenschön Holger
Published: April 2012

The generation of (η6‐aryne)chromium complexes as reactive intermediates was investigated in two ways. Although earlier attempts directed towards triflate eliminations from a variety of tricarbonyl(phenyl triflate)chromium complexes had failed, more electron‐rich phenyl triflate complexes were considered. This was accomplished either by substitution with two methoxy groups in the arene ligand or by replacement of one of the three carbonyl ligands of the tricarbonylchromium complex with triphenylphosphane. However, the attempted elimination still did not take place; in spite of the increased electron densities in the aromatic ligands, anionic thia‐Fries rearrangements were observed in high yields at –78 °C. As an alternative, elimination of lithium fluoride was tested. Tricarbonyl(2‐lithiofluorobenzene)chromium(0) was generated by tin/lithium exchange. After hydrolytic workup, tricarbonyl(fluorobenzene)chromium was obtained as the main product, indicating that the lithiation step had been successful. A dimeric side product provided evidence for the intermediacy of (benzyne)tricarbonylchromium.
Voltammetric Sensing of Amino Acids in the Presence of Cu(II) in Acidic and Alkaline Solutions
Authors: Pauliukaite Rasa , Pinto Edilson M. , Amine Aziz , Brett Christopher M. A.
Published: April 2012

A number of amino acids have been determined at carbon film electrodes in the presence of copper. Strongly acidic, 0.1 M HCl, in the presence of 0.1 mM Cu(II), as well as alkaline, 0.1 M NaOH, solution permit successful measurement of individual amino acids, clearer separation between oxidation of Cu and Cu‐complexes occurring in alkaline solution. Electrochemical impedance showed that Cu(II) facilitates charge transfer, particularly in alkaline medium. Square wave voltammetry with preconcentration increased the response compared to linear sweep voltammetry. Protein hydrolysis rates were monitored through determination of amino acids produced by decomposition, injecting samples into alkaline electrolyte solution.
Long Distance Electron Transfer Across >100 nm Thick Au Nanoparticle/Polyion Films to a Surface Redox Protein
Authors: Chai Hongmei , Liu Hongyun , Guo Xihong , Zheng Dong , Kutes Yasemin , Huey Bryan D. , Rusling James F. , Hu Naifei
Published: April 2012

Glutathione‐decorated 5 nm gold nanoparticles (AuNPs) and oppositely charged poly(allylamine hydrochloride) (PAH) were assembled into {PAH/AuNP}n films fabricated layer‐by‐layer (LbL) on pyrolytic graphite (PG) electrodes. These AuNP/polyion films utilized the AuNPs as electron hopping relays to achieve direct electron transfer between underlying electrodes and redox proteins on the outer film surface across unprecedented distances >100 nm for the first time. As film thickness increased, voltammetric peak currents for surface myoglobin (Mb) on these films decreased but the electron transfer rate was relatively constant, consistent with a AuNP‐mediated electron hopping mechanism.
Hexokinase II knockdown results in exaggerated cardiac hypertrophy via increased ROS production
Authors: Wu Rongxue , Wyatt Eugene , Chawla Kusum , Tran Minh , Ghanefar Mohsen , Laakso Markku , Epting Conrad L. , Ardehali Hossein
Published: April 2012

Hexokinase‐II (HKII) is highly expressed in the heart and can bind to the mitochondrial outer membrane. Since cardiac hypertrophy is associated with a substrate switch from fatty acid to glucose, we hypothesized that a reduction in HKII would decrease cardiac hypertrophy after pressure overload. Contrary to our hypothesis, heterozygous HKII‐deficient (HKII+/−) mice displayed increased hypertrophy and fibrosis in response to pressure overload. The mechanism behind this phenomenon involves increased levels of reactive oxygen species (ROS), as HKII knockdown increased ROS accumulation, and treatment with the antioxidant N‐acetylcysteine (NAC) abrogated the exaggerated response. HKII mitochondrial binding is also important for the hypertrophic effects, as HKII dissociation from the mitochondria resulted in de novo hypertrophy, which was also attenuated by NAC. Further studies showed that the increase in ROS levels in response to HKII knockdown or mitochondrial dissociation is mediated through increased mitochondrial permeability and not by a significant change in antioxidant defenses. Overall, these data suggest that HKII and its mitochondrial binding negatively regulate cardiac hypertrophy by decreasing ROS production via mitochondrial permeability.
INVESTIGATING ATTRIBUTE NON‐ATTENDANCE AND ITS CONSEQUENCES IN CHOICE EXPERIMENTS WITH LATENT CLASS MODELS
Authors: Lagarde Mylene
Published: April 2012

A growing literature, mainly from transport and environment economics, has started to explore whether respondents violate some of the axioms about individuals' preferences in Discrete Choice Experiments (DCEs) and use simple strategies to make their choices. One of these strategies, termed attribute non‐attendance (ANA), consists in ignoring one or more attributes. Using data from a DCE administered to healthcare providers in Ghana to evaluate their potential resistance to changes in clinical guidelines, this study illustrates how latent class models can be used in a step‐wise approach to account for all possible ANA strategies used by respondents and explore the consequences of such behaviours. Results show that less than 3% of respondents considered all attributes when choosing between the two hypothetical scenarios proposed, with a majority looking at only one or two attributes. Accounting for ANA strategies improved the goodness‐of‐fit of the model and affected the magnitude of some of the coefficient and willingness‐to‐pay estimates. However, there was no difference in the predicted probabilities of the model taking into account ANA and the standard approach. Although the latter result is reassuring about the ability of DCEs to produce unbiased policy guidance, it should be confirmed by other studies. Copyright © 2012 John Wiley & Sons, Ltd.
Microtopography, water storage and flow patterns in a fine‐textured soil under agricultural use
Authors: Bogner Christina , Mirzaei Mohammadreza , Ruy Stéphane , Huwe Bernd
Published: April 2012

Agricultural use of soils implies tillage and often compaction and therefore influences processes on soil surface and affects infiltration of water into the subsoil. Although many studies on soil surface processes or flow patterns in soils exist, works relating both are rare in literature. We did two tracer experiments with Brilliant Blue FCF on a tilled and compacted plot and a non‐tilled one to investigate water storage on the soil surface during simulated rainfall and changes of soil microtopography, to analyse the associated flow patterns in the soil and to relate both to tillage and compaction. Our results show that storage was larger on the tilled and compacted plot than on the non‐tilled one. After tillage, transport processes above the plough pan were partly disconnected from those underneath because macropores were disrupted and buried by the tillage operation. However, preferential flow along cracks occurred on both plots and the macropores buried below the tillage pan still functioned as preferential flow paths. Therefore, we conclude that the studied soil is susceptible to deep vertical solute propagation at dry conditions when cracks are open, irrespective of tillage and compaction. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of hydration on assessment of early enamel lesion using swept‐source optical coherence tomography
Authors: Nazari Amir , Sadr Alireza , Campillo‐Funollet Marc , Nakashima Syozi , Shimada Yasushi , Tagami Junji , Sumi Yasunori
Published: April 2012

Establishing reproducible methodologies for assessment of early enamel lesions using optical coherence tomography (OCT) appears to be challenging. This in vitro study longitudinally evaluated the subsurface enamel lesion progression after 3, 9 and 15 days by cross‐sectional scanning using 1310 nm centered swept‐source OCT (SS‐OCT) under hydrated and dry conditions. The positive difference between the depth‐integrated OCT signals at dry and hydrated conditions were calculated and adopted as dehydration parameter (DH). A linear regression was found between DH and the square root of demineralization time (R2 = 0.99). Significant differences were found in DH between sound and demineralized enamel, and between different periods of demineralization (p < 0.001). Hydration state affects the reflectivity of demineralized porous enamel, and the effect can be potentially used for assessment of early enamel lesion using OCT. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of a dual joystick‐controlled laser trapping and cutting system for optical micromanipulation of chromosomes inside living cells
Authors: Harsono Marcellinus S. , Zhu Qingyuan , Shi Linda Z. , Duquette Michelle , Berns Michael W.
Published: April 2012

A multi‐joystick robotic laser microscope system used to control two optical traps (tweezers) and one laser scissors has been developed for subcellular organelle manipulation. The use of joysticks has provided a “user‐friendly” method for both trapping and cutting of organelles such as chromosomes in live cells. This innovative design has enabled the clean severing of chromosome arms using the laser scissors as well as the ability to easily hold and pull the severed arm using the laser tweezers. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab initio study of the positronation of the CaO and SrO molecules including calculation of annihilation rates
Authors: Buenker Robert J. , Liebermann Heinz‐Peter
Published: April 2012

Ab initio multireference single‐ and double‐excitation configuration interaction calculations have been performed to compute potential curves for ground and excited states of the CaO and SrO molecules and their positronic complexes, e+CaO, and e+SrO. The adiabatic dissociation limit for the 2Σ+ lowest states of the latter systems consists of the positive metal ion ground state (M+) and the OPs complex (e+O−), although the lowest energy limit is thought to be e+M + O. Good agreement is found between the calculated and experimental spectroscopic constants for the neutral diatomics wherever available. The positron affinity of the closed‐shell X
1Σ+ ground states of both systems is found to lie in the 0.16–0.19 eV range, less than half the corresponding values for the lighter members of the alkaline earth monoxide series, BeO and MgO. Annihilation rates (ARs) have been calculated for all four positronated systems for the first time. The variation with bond distance is generally similar to what has been found earlier for the alkali monoxide series of positronic complexes, falling off gradually from the OPs AR value at their respective dissociation limits. The e+SrO system shows some exceptional behavior, however, with its AR value reaching a minimum at a relatively large bond distance and then rising to more than twice the OPs value close to its equilibrium distance. © 2012 Wiley Periodicals, Inc.
Density functional theory study of 1,2‐dioxetanone decomposition in condensed phase
Authors: da Silva Luís Pinto , da Silva Joaquim C.G. Esteves
Published: April 2012

The decomposition of 1,2‐dioxetanone into a CO2 molecule and into an excited state formaldehyde molecule was studied in condensed phase, using a density functional theory approach. Singlet and triplet ground and excited states were all included in the calculations. The calculations revealed a novel mechanism for the chemiluminescence of this compound. The triplet excitation can be explained by two intersystem crossings (ISCs) with the ground state, while the singlet excitation can be accounted by an ISC with the triplet state. The experimentally verified small excitation yield can then be explained by the presence of an energy barrier present in the potential energy surface of the triplet excited state, which will govern both triplet and singlet excitation. It was also found that the triplet ground state interacts with both the triplet excited and singlet ground states. A MPWB1K/mPWKCIS approach provided results in agreement with the existent literature. © 2012 Wiley Periodicals, Inc.
Determination of five priority haloacetic acids by capillary electrophoresis with contactless conductivity detection and solid phase extraction preconcentration
Authors: Kubáň Petr , Makarõtševa Natalja , Kiplagat Isaac K. , Kaljurand Mihkel
Published: April 2012

A sensitive capillary electrophoretic separation method with contactless conductivity detection (C4D) for analysis of five priority haloacetic acids (HAA5) is presented. The analytes were baseline separated in an electrolyte composed of 20 mM 2‐(N‐Morpholino) ethanesulfonic acid (MES), 20 mM L‐histidine (HIS), and 30 μM cetyltrimethylammonium bromide (CTAB) at pH 6.0 in less than 4 min. A simplified solid‐phase extraction (SPE) preconcentration procedure on highly cross‐linked polystyrene‐divinylbenzene (PS‐DVB) type sorbent was developed and optimized with respect to short preconcentration time. HAA5 from a 25‐mL sample aliquot of tap and swimming pool water could be preconcentrated in less than 5 min using an in‐house made SPE column with recoveries ranging from 23 to 98%. Combining the SPE preconcentration procedure with capillary electrophoretic analysis, the attained limits of detection were between 6.1 and 12.2 μg/L with total analysis time of less than 10 min.
Online extraction and isolation of highly polar chemical constituents from Brassica napusL. pollen by high shear technique coupled with high‐performance counter‐current chromatography
Authors: Feng Zu-fei , Chen Xiao‐fen , Di Duo‐long
Published: April 2012

High shear technique coupled with high‐performance counter‐current chromatography was successfully used for the extraction and online isolation of seven highly polar chemical constituents from the Brassica napus L. The lower phase of ethyl acetate–n‐butanol–water (1:4:5, v:v:v) was used as both the high shear technique solvent and high‐performance counter‐current chromatography mobile phase. Seven compounds of 14.2 mg of uridine, 4.6 mg of xanthosine, 7.8 mg of guanosine, 5.3 mg of adenosine, 19.5 mg of kaempferol‐3,4'‐di‐O‐β‐D‐glucopyranoside, 17.7 mg of kaempferol‐3‐O‐(2‐O‐β‐D‐glucopyranosy1)‐β‐D‐glucopyranoside, and 25.7 mg of an unknown compound, with a high‐performance liquid chromatography (HPLC) purity over 95.0%, were obtained in a one‐step extraction‐separation process within 130 min from 20.0 g of raw material of pollen of Brassica napus L. Moreover, the mode of elution–extrusion was employed for the separation of the last one compound. The isolated compounds were analyzed by HPLC, and the chemical structures of the compounds mentioned above were identified by UV and NMR. It is the first time to combine the high shear technique and high‐performance counter‐current chromatography for the online isolation of the nature products.
Remission of PTSD after victims of intimate partner violence leave a shelter
Authors: Johnson Dawn M. , Zlotnick Caron
Published: April 2012

Intimate partner violence (IPV) is a significant public health problem associated with high rates of posttraumatic stress disorder (PTSD). Few longitudinal studies have investigated IPV‐related PTSD and we know of only 1 longitudinal study to date that has explored IPV‐related PTSD in residents of battered women's shelters. The current report describes a prospective study of IPV‐related PTSD in an initial sample of 147 residents of battered women's shelters. Baseline correlates of remission of IPV‐related PTSD (i.e., PTSD and IPV severity, loss of personal and social resources, cessation of abuse, reunion with abuser, and length of shelter stay) over a 6‐month follow‐up period were investigated. Although findings are consistent with prior research suggesting a natural recovery of PTSD in IPV‐victims, they also show that a significant number (46.8%) of women exhibit chronic PTSD. Participants whose PTSD remitted over follow‐up had at baseline less severe IPV‐related PTSD (partial η2 = .104) and fewer loss of personal and social resources (partial η2 = .095), and were less likely to reunite with their abuser after leaving the shelter than participants with chronic PTSD (3.3% and 22.4%, respectively). Clinical implications and limitations of findings are discussed.
Finding meaning in a traumatic loss: A families approach
Authors: Davis Christopher G. , Harasymchuk Cheryl , Wohl Michael J. A.
Published: April 2012

Meaning‐making, like much of coping research, has been conceptualized and assessed as an individual‐centered phenomenon. On the premise that most traumas affect families as a whole, we assessed the extent to which meanings following a traumatic loss were congruent within families. Qualitative and quantitative data from family members coping with the loss of a family member in a mine explosion indicated moderate family congruence in meanings and global well‐being. Furthermore, greater family similarity in meaning was associated with less depressive affect in individuals (pseudoR2= .063), but was not associated with individual differences in well‐being. The research highlights the important role that families play in coping with trauma.
A pilot study of a 12‐week model of group‐based exposure therapy for veterans with PTSD
Authors: Sutherland Roy John , Mott Juliette M. , Lanier Stacey Holmes , Williams Wright , Ready David J. , Teng Ellen J.
Published: April 2012

Group‐based exposure therapy (GBET) is an intensive group treatment that targets posttraumatic stress disorder (PTSD) symptoms through repeated imaginal and in vivo exposure. The purpose of the present study was to assess the feasibility and acceptability of a modified 12‐week course of GBET (modified from the standard 16 weeks) and to examine its effectiveness in reducing veterans' PTSD symptoms. Participants were 10 male Operation Iraqi Freedom and Vietnam‐era veterans recruited from a PTSD specialty clinic at a large Veterans Affairs Medical Center. All participants were retained and demonstrated clinically significant reductions in PTSD symptoms (η2 = .84–.87) comparable to the standard protocol. The findings from this small sample indicate that the abbreviated 12‐week GBET protocol is a potentially effective treatment for PTSD.
Risk factors for PTSD, anxiety, and depression among adolescents in gaza
Authors: Kolltveit Silje , Lange‐Nielsen Ida Ingridsdatter , Thabet Abdel Aziz Mousa , Dyregrov Atle , Pallesen Ståle , Johnsen Tom Backer , Laberg Jon Christian
Published: April 2012

The present study examined among adolescents in Gaza the relationship between exposure to war stressors and psychological distress as well as the effects of age, gender, and socioeconomic status. Data were collected from a sample of 139 adolescents 12 to 17 years old. Results showed that adolescents reported elevated levels of intrusion, avoidance, and depression compared to levels in communities not affected by war in the recent past. The proportion scoring within the clinical range of posttraumatic stress disorder (PTSD) was 56.8% compared to 6.3% in peacetime populations, reflecting a Hedges'sgof 1.29 (p< .001). Significant risk factors for PTSD were exposure (β = .377,p< .001), female gender (β = −.257,p< .001), older age (β = .280,p< .01), and an unemployed father (β = −.280,p< .01). Risk factors for anxiety were exposure (β = .304,p< .001), female gender (β = −.125,p< .01), and older age (β = 272,p< .01), whereas female gender (β = <.238,p< .001) was the only significant risk factor for depression. The present study suggests large individual differences in how adolescents are affected by war stressors.
Neural substrates for processing task‐irrelevant emotional distracters in maltreated adolescents with depressive disorders: A pilot study
Authors: De Bellis Michael D. , Hooper Stephen R.
Published: April 2012

In this pilot study, neural systems related to cognitive and emotional processing were examined using event‐related functional magnetic resonance imaging in 5 maltreated youth with depressive disorders and 11 nonmaltreated healthy participants. Subjects underwent an emotional oddball task, where they detected infrequent ovals (targets) within a continual stream of phase‐scrambled images (standards). Sad and neutral images were intermittently presented as task‐irrelevant distracters. The maltreated youth revealed significantly decreased activation in the left middle frontal gyrus and right precentral gyrus to target stimuli and significantly increased activation to sad stimuli in bilateral amygdala, left subgenual cingulate, left inferior frontal gyrus, and right middle temporal cortex compared to nonmaltreated subjects. Additionally, the maltreated youth showed significantly decreased activation to both attentional targets and sad distracters in the left posterior middle frontal gyrus compared to nonmaltreated subjects. In this exploratory study of dorsal control and ventral emotional circuits, we found that maltreated youth with distress disorders demonstrated dysfunction of neural systems related to cognitive control and emotional processing.
Identification of trauma exposure and PTSD in adolescent psychiatric inpatients: An exploratory study
Authors: Havens Jennifer F. , Gudiño Omar G. , Biggs Emily A. , Diamond Ursula N. , Weis J. Rebecca , Cloitre Marylene
Published: April 2012

Trauma exposure and posttraumatic stress disorder (PTSD), though prevalent among adolescent psychiatric inpatients, are underidentified in standard clinical practice. In a retrospective chart review of 140 adolescents admitted to a psychiatric inpatient unit, we examined associations between probable PTSD identified through the Child PTSD Symptom Scale and adolescents' service use and clinical characteristics. Results suggest a large discrepancy between rates of probable PTSD identified through standardized assessment and during the emergency room psychiatric evaluation (28.6% vs. 2.2%). Adolescents with probable PTSD had greater clinical severity and service utilization, an increased likelihood of being diagnosed with bipolar disorder (27.5% vs. 9.2%) and being prescribed antipsychotic medications (47.5% vs. 27.6%), and were prescribed more psychotropic medications. Upon discharge, those with probable PTSD were more than those without to be assigned a diagnosis of PTSD (45% vs. 7.1%), a comorbid diagnosis of major depressive disorder (30% vs. 14.3%), to be prescribed an antidepressant medication (52.5% vs. 33.7%), and to be prescribed more medications. The underidentification of trauma exposure and PTSD has important implications for the care of adolescents given that accurate diagnosis is a prerequisite for providing effective care. Improved methods for identifying trauma‐related problems in standard clinical practice are needed.
The role of shame in distinguishing perpetrators of intimate partner violence in U.S. veterans
Authors: Hundt Natalie E. , Holohan Dana R.
Published: April 2012

Increasing attention is being paid to the fact that exposure to traumatic stressors in military combat may lead to perpetration of intimate partner violence (IPV). Because shame has been identified as a factor in posttraumatic stress disorder (PTSD), the current cross‐sectional study examined the relationship in U.S. veterans between IPV and PTSD, depression, guilt, and shame. We hypothesized that shame would be the strongest correlate of perpetration of IPV and that shame would mediate the relationship between PTSD and IPV. Participants were 264 primarily male and Caucasian mixed‐era veterans presenting for psychological treatment at a Veterans Affairs hospital. They completed standard measures of depression, PTSD symptoms, shame, and guilt and a local checklist was used to dichotomize the sample regarding IPV. Discriminant analysis indicated that shame contributed most (standardized canonical discriminant function coefficient = .44) to distinguishing perpetrators of IPV. In addition, the results were consistent with shame as a mediator of the relationship between PTSD and IPV. These results are in line with studies indicating that shame is linked to IPV perpetration in nonveteran samples (Harmon, 2002; Rand, 2004; Schibik, 2002) and suggests that shame may be an important aspect of the relationship between PTSD and IPV.
Harvest of red‐legged partridge in central Spain
Authors: Díaz‐Fernández Silvia , Viñuela Javier , Arroyo Beatriz
Published: April 2012

A basic rule to attain sustainable use of harvested resources is to adjust take to availability. Populations of red‐legged partridges in Spain have decreased in recent decades, and releases of farm‐bred partridges to improve short‐term availability are increasingly common. We used questionnaires and bird surveys to assess whether harvest was related to availability of wild partridges or intensity of farm‐bred partridge releases. We studied 50 hunting estates, including 6 administratively labeled as intensive (with few numerical and temporal restrictions to releases). In addition, we considered hunting pressure (number of hunters × hunting days/km2) and habitat as explanatory variables in the analyses. In intensive estates, annual harvest was exclusively related to release intensity, indicating that in these estates hunting is detached from natural resources and approaches an industrial activity based on external inputs. In non‐intensive estates, harvest was affected by wild stock availability, walked‐up shooting pressure, and habitat (greater harvest in estates with more Mediterranean shrubland). In these estates, releases did not increase annual harvest, and can be considered an inefficient practice. Additionally, the relationship between abundance estimates and harvest disappeared in estates with low partridge abundance estimates, suggesting possibilities for overharvesting in a large proportion of estates. Increasing the abundance of wild red‐legged partridge through techniques like habitat management, and improving the adjustment of harvest to availability, may be a good strategy to increase long‐term harvest in non‐intensive estates. Additionally, Government and managers must create ways to segregate and label the estates where only wild red‐legged partridges are managed from those where releases are used, to reduce ecological costs of management decisions. © 2012 The Wildlife Society.
Thermal decomposition of 4‐hydroxy‐2‐butanone in m‐xylene solution: Experimental and computational study
Authors: Murillo Juliana , Henao Diana , Vélez Ederley , Castaño Carolina , Quijano Jairo , Gaviria Jair , Zapata Edilma
Published: April 2012

The mechanism of thermal decomposition of 4‐hydroxy‐2‐butanone in m‐xylene solution was studied experimentally and theoretically at the M05‐2X/6‐31G(d, p) level of theory. It follows first‐order kinetics and appears to be homogeneous and unimolecular. The proposed mechanism is via a six‐membered cyclic transition state to give a mixture of formaldehyde and acetone. Rate constant values were experimentally determined at three temperatures: 483.15, 493.15, and 503.15 K. Calculated rate constants are of the same order of magnitude than the experimental ones. Calculated Gibbs energies of activation agree very well with the experimental values. Computationally, the progress of the reactions was followed by means of the Wiberg bond index. The results indicate that the transition state has an intermediate character between reactants and products, and the calculated synchronicity shows that the reaction is slightly asynchronous. The bond‐breaking processes are more advanced than the bond‐forming ones, indicating a bond deficiency in the transition state. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 407–413, 2012
Merkel cell carcinoma: Identification of prognostic factors unique to tumors located in the head and neck based on analysis of SEER data
Authors: Smith Valerie A. , Camp E. Ramsay , Lentsch Eric J.
Published: April 2012

Objectives/Hypothesis:

Merkel cell carcinoma (MCC) is an aggressive cutaneous neoplasm that occurs most frequently in the head and neck region. Because of its rarity, prognostic factors are poorly characterized. Head and neck MCC (HN‐MCC) may require separate consideration from MCC that occurs in other anatomic regions. Our objective was to determine the relevance of clinicopathologic parameters as prognostic factors in a large series of patients with HN‐MCC and to compare these to a series of patients with non–head and neck MCC (NHN‐MCC).

Study Design:

Retrospective analysis of large population database.

Methods:

Patients with MCC were identified using the Surveillance, Epidemiology, and End Results database and categorized according to tumor location either 1) within or 2) outside of the head and neck region. Clinicopathologic data were compared between groups. Retrospective univariable and multivariable analyses of factors associated with disease‐specific survival (DSS) were performed.

Results:

We identified 2,104 patients with HN‐MCC and 2,272 with NHN‐MCC. DSS was similar between groups. Independent prognostic factors in HN‐MCC are male sex (P < .001), lip primary site (P = .005), tumor extension beyond the dermis (P = .03), histologically confirmed nodal disease (P < .001), absence of histologic lymph node evaluation (P = .01), and distant metastasis (P = .001). Male sex and tumor extension limited to the subcutis are prognostic factors that are unique to HN‐MCC.

Conclusions:

Because independent markers of aggressive disease appear to be unique in HN‐MCC, it is important that future studies provide separate consideration for HN‐MCC to allow for the most accurate identification of prognostic indicators and assessment of treatment outcomes accordingly.
Postoperative hemorrhage following adenoidectomy
Authors: Tomkinson Alun , Harrison Wendy , Owens David , Fishpool Samuel , Temple Mark
Published: April 2012

Objectives/Hypothesis:

To examine postoperative hemorrhage following adenoidectomy.

Study Design:

Prospective multicenter observational study.

Methods:

The Surgical Instrument Surveillance Programme (SISP) was established in 2003 to monitor tonsil and adenoid surgery in all hospitals in Wales. Data were examined between April 1, 2003 and June 30, 2008, for risk factors that may contribute to primary (R1) or secondary (R2) postoperative hemorrhage from the adenoid bed, of a severity sufficient to require a return to the operating room.

Results:

There were 5,588 procedures included, of which 4,225 included simultaneous tonsillectomy. The study included 2,903 (52%) males with a median age of 5.8 years (interquartile range [IQR], 4.5–7.7 years) and 2,685 (48%) females with a median age of 6.5 years (IQR, 5.0–9.1 years). There were 22 patients (0.4%; confidence interval [CI], 0.2‐0.6) who returned to the operating room with a postoperative hemorrhage arising from the adenoid bed. These were exclusively R1 hemorrhage; there were no instances of R2 hemorrhage (0.0%; CI, 0.0‐0.1). No specific risk factors for R1 hemorrhage could be identified. There were 38 patients in the adenotonsillectomy group who returned to operating room with a postoperative hemorrhage arising from the tonsil bed (0.5%; CI, 0.3‐0.8). R1 was seen in 22 patients (0.5%; CI, 0.3‐0.8) and R2 in 16 patients (0.4%; CI, 0.2‐0.6).

Conclusions:

Adenoidectomy appears to be primarily a procedure performed in childhood. The rate of R1 hemorrhage following adenoidectomy is one in 200 (0.5%) and is similar to the R1 hemorrhage rate for tonsillectomy. R2 hemorrhage following an adenoidectomy appears to be extremely rare. In children, the risk of a serious primary hemorrhage following an adenotonsillectomy is double that of either procedure when performed alone.