bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon Monoxide Induces Hypothermia Tolerance in Kupffer Cells and Attenuates Liver Ischemia/Reperfusion Injury in Rats†
Authors: Lee Lung-Yi , Kaizu Takashi , Toyokawa Hideyoshi , Zhang Matthew , Ross Mark , Stolz Donna B. , Huang Chao , Gandhi Chandrashekhar , Geller David A. , Murase Noriko
Published: August 2011

Ischemia/reperfusion (I/R) injury in liver grafts, which is initiated by cold preservation and is augmented by reperfusion, is a major problem that complicates graft quality, posttransplant patient care, and outcomes of liver transplantation (LT). Kupffer cells (KCs) play important roles in I/R injury; however, little is known about their changes during cold preservation. We examined whether a pretreatment with carbon monoxide (CO), a cytoprotective product of heme degradation, could influence KC activity during cold storage and protect liver grafts against LT-induced I/R injury. In vitro, primary rat KCs were stimulated for 24 hours under hypothermic conditions (4°C, 20% O2), with lipopolysaccharide, or under hypoxic conditions (37°C, 5% O2) with or without a CO pretreatment. When rat KCs were exposed to hypothermic conditions, they produced reactive oxygen species (ROS), but they did not produce tumor necrosis factor α (TNF-α) or nitric oxide. The preincubation of KCs with CO up-regulated heat shock protein 70 (HSP70) and inhibited ROS generation. When liver grafts from donor rats exposed to CO (250 ppm) for 24 hours were transplanted after 18 hours of cold preservation in University of Wisconsin solution, HSP70 expression increased in these grafts versus control grafts, and serum aspartate aminotransferase and alanine aminotransferase levels as well as necrotic areas and inflammatory infiltrates were significantly reduced after LT. CO-pretreated liver grafts showed less up-regulation of TNF-α and inducible nitric oxide synthase messenger RNA (mRNA) and reduced expression of proapoptotic B cell lymphoma 2–associated X protein mRNA, cleaved caspase-3, and poly(adenosine diphosphate ribose) polymerase. In conclusion, the pretreatment of donors with CO ameliorates LT-associated I/R injury with increased hepatic HSP70 expression, particularly in the KC population. Liver Transpl, 2011. © 2011 AASLD.
A Randomized, Multicenter Study Comparing Steroid-Free Immunosuppression and Standard Immunosuppression for Liver Transplant Recipients With Chronic Hepatitis C†
Authors: Klintmalm Göran B. , Davis Gary L. , Teperman Lewis , Netto George J. , Washburn Kenneth , Rudich Stephen M. , Pomfret Elizabeth A. , Vargas Hugo E. , Brown Robert , Eckhoff Devin , Pruett Timothy L. , Roberts John , Mulligan David C. , Charlton Michael R. , Heffron Thomas G. , Ham John M. , Douglas David D. , Sher Linda , Baliga Prabhakar K. , Kinkhabwala Milan , Koneru Baburao , Abecassis Michael , Millis Michael , Jennings Linda W. , Fasola Carlos G.
Published: August 2011

This randomized, prospective, multicenter trial compared the safety and efficacy of steroid-free immunosuppression (IS) to the safety and efficacy of 2 standard IS regimens in patients undergoing transplantation for hepatitis C virus (HCV) infection. The outcome measures were acute cellular rejection (ACR), severe HCV recurrence, and survival. The patients were randomized (1:1:2) to tacrolimus (TAC) and corticosteroids (arm 1; n = 77), mycophenolate mofetil (MMF), TAC, and corticosteroids (arm 2; n = 72), or MMF, TAC, and daclizumab induction with no corticosteroids (arm 3; n = 146). In all, 295 HCV RNA–positive subjects were enrolled. At 2 years, there were no differences in ACR, HCV recurrence (biochemical evidence), patient survival, or graft survival rates. The side effects of IS did not differ, although there was a trend toward less diabetes in the steroid-free group. Liver biopsy samples revealed no significant differences in the proportions of patients in arms 1, 2, and 3 with advanced HCV recurrence (ie, an inflammation grade ≥ 3 and/or a fibrosis stage ≥ 2) in years 1 (48.2%, 50.4%, and 43.0%, respectively) and 2 (69.5%, 75.9%, and 68.1%, respectively). Although we have found that steroid-free IS is safe and effective for liver transplant recipients with chronic HCV, steroid sparing has no clear advantage in comparison with traditional IS. Liver Transpl, 2011. © 2011 AASLD.
Computed Tomography Liver Volumetry Using 3-Dimensional Image Data in Living Donor Liver Transplantation: Effects of the Slice Thickness on the Volume Calculation†
Authors: Hori Masatoshi , Suzuki Kenji , Epstein Mark L. , Baron Richard L.
Published: August 2011

The purpose of this study was to evaluate the relationship between the slice thickness and the calculated volume in computed tomography (CT) liver volumetry through the comparison of the results from images [including 3-dimensional (3D) images] with various slice thicknesses. Twenty potential adult liver donors (12 men and 8 women) with a mean age of 39 years (range = 24-64 years) underwent CT with a 64-section multidetector row CT scanner after the intravenous injection of a contrast material. Four image sets with slice thicknesses of 0.625, 2.5, 5, and 10 mm were used. First, a program developed in our laboratory for automated liver extraction was applied to the CT images, and the liver boundaries were determined automatically. Then, an abdominal radiologist reviewed all images onto which automatically extracted boundaries had been superimposed and then edited the boundaries on each slice to enhance the accuracy. The liver volumes were determined via the counting of the voxels within the liver boundaries. The mean whole liver volumes estimated with CT were 1322.5 cm3 from 0.625-mm images, 1313.3 cm3 from 2.5-mm images, 1310.3 cm3 from 5-mm images, and 1268.2 cm3 from 10-mm images. The volumes calculated from 3D (0.625-mm) images were significantly larger than the volumes calculated from thicker images (P < 0.001). The partial liver volumes of right lobes, left lobes, and lateral segments were evaluated in a similar manner. The estimated maximum difference in the calculated volumes of lateral segments was −10.9 cm3 (−4.63%) between 0.625- and 5-mm images. In conclusion, liver volumes calculated from 2.5-mm-thick or thicker images are significantly smaller than liver volumes calculated from 3D images. If a maximum error of 5% in the calculated graft volume will not have a significant clinical impact, 5-mm-thick images are acceptable for CT volumetry. If the impact is significant, 3D images could be essential. Liver Transpl, 2011. © 2011 AASLD.
Hot-topic debate on tolerance: Immunosuppression withdrawal
Authors: Sánchez-Fueyo Alberto
Published: August 2011

Key Points

1. Liver allografts exhibit intrinsic tolerogenic properties that result in their spontaneous acceptance in many experimental animal models.

2. In clinical transplantation, liver allografts require milder immunosuppression regimens than other organs, are relatively resistant to antibody-mediated rejection, and only very rarely are lost because of immunological insults.

3. A fraction of stable liver transplant recipients can withdraw from all immunosuppression therapy and then maintain normal graft function and not experience rejection. This phenomenon is known as spontaneous operational tolerance (SOT).

4. The intentional discontinuation of immunosuppression in stable liver transplant recipients has led to successful weaning in almost 20% of recipients, but the true prevalence of SOT in unselected recipients is still unknown.

5. The prevalence could be higher in pediatric recipients undergoing transplantation before 1 year of age and in adult recipients with more than 10 years of posttransplant follow-up.

6. Rejection occurring during medically supervised immunosuppression weaning trials tends to be mild and, in the overwhelming majority of cases, can be easily resolved without the administration of high-dose immunosuppression.

7. Tolerant liver recipients exhibit specific transcriptional patterns in peripheral blood and liver tissue that may constitute future diagnostic markers of tolerance.

8. There is still no formal proof that the discontinuation of low-dose immunosuppression in long-term survivors of liver transplantation improves the morbidity and mortality rates associated with immunosuppression therapy.
Immunosuppression in pediatric liver transplantation: Are little people different?
Authors: Dhawan Anil
Published: August 2011

Key Points

1. Children differ from adults in the pharmacokinetics and dynamics of most immunosuppressive agents.

2. A lack of clinical trials continues to be an issue for newer agents.

3. On the basis of clinical case series, mycophenolate mofetil and sirolimus are increasingly being used as renal-sparing agents.

4. In comparison with adults, the recurrence of both viral hepatitis and hepatocellular carcinoma is less of an issue in children.

5. Particular attention should be paid to complete age-appropriate immunization to avoid vaccine-preventable diseases.

6. Paying special attention to adherence and the transition to adult services is essential for minimizing graft loss.
Modeling Choices for Virtual Screening Hit Identification
Authors: Bergeron Charles , Krein Michael , Moore Gregory , Breneman Curt M. , Bennett Kristin P.
Published: August 2011

Making suitable modeling choices is crucial for successful in silico drug design, and one of the most important of these is the proper extraction and curation of data from qHTS screens, and the use of optimized statistical learning methods to obtain valid models. More specifically, we aim to learn the top‐1 % most potent compounds against a variety of targets in a procedure we call virtual screening hit identification (VISHID). To do so, we exploit quantitative high‐throughput screens (qHTS) obtained from PubChem, descriptors derived from molecular structures, and support vector machines (SVM) for model generation. Our results illustrate how an appreciation of subtle issues underlying qHTS data extraction and the resulting SVM models created using these data can enhance the effectiveness of solutions and, in doing so, accelerate drug discovery.
A Survey of Evidence‐Based Practise among Dutch Occupational Therapists
Authors: Döpp Carola M. E. , Steultjens Esther M. J. , Radel Jeff
Published: August 2011

This study explored how the evidenced‐based practise (EBP) is perceived by Dutch occupational therapists (OTs), what sources of research data are used to make clinical decisions, and what barriers are identified in implementing EBP.

A self‐administered, pre‐tested, questionnaire was distributed through an email survey and postal mail among the 200 randomly stratified selected OTs out of a total population of 2,019 Dutch OTs. Analyses of data comprised descriptive statistics of all variables and test statistics to evaluate the differences between demographical groups.

Dutch OTs have a very positive attitude toward the EBP. Barriers experienced are mostly related to a lack of skills needed to implement the EBP and to the characteristics of the work environment. The attitude, experiences and barriers are mainly similar to research findings in other countries or professions. A unique barrier to the implementation of the EBP found in this study was that Dutch OTs perceived evidence written in a foreign (non‐Dutch) language as a barrier to using evidence in non‐Dutch languages.

The results of the study, derived from a partly representative group of working OTs, implicate universal problems regarding the effective implementation of the EBP. Solutions to increase the implementation of the EBP from an international point of view are called for and need to be evaluated. Copyright © 2011 John Wiley & Sons, Ltd.
Tissue doppler evaluation of systolic and diastolic cardiac functions in long‐term survivors of Hodgkin lymphoma
Authors: Alehan Dursun , Şahin Murat , Varan Ali , Yıldırım Işıl , Küpeli Serhan , Büyükpamukçu Münevver
Published: August 2011

Background

Monitoring for late adverse events is crucial in long‐term management of childhood cancer survivors. A case–control study to evaluate long‐term cardiovascular status of childhood Hodgkin lymphoma (HL) using tissue Doppler imaging (TDI) was performed.

Patients and Methods

Patients diagnosed with HL before age of 18 that completed therapy and were in remission and a control group of healthy children were evaluated by echocardiography and TDI.

Results

Total of 72 HL survivors were included in the study. Median age at diagnosis, remission time, and age at time of echocardiography were 7 (2–16), 9 (2–20), and 17.5 (7–27) years, respectively. TDI revealed decreased S′ velocity, reflecting systolic dysfunction in HL survivors, at medial and lateral mitral annuli and at middle segment of interventricular septum (IVS; P < 0.01) for all. Moreover, TDI showed decreased peak E′ velocity at medial mitral annulus [12.4 cm/s (5.5–16.3) vs. 13.3 cm/s (10.2–18.9), P = 0.03] and at middle segment of IVS [10 cm/s (5.3–16.3) vs. 11.6 cm/s (6.7–16.7), P < 0.01] and prolongation of isovolemic relaxation time at medial and lateral annuli of the mitral valve (P < 0.01) and at middle segment of IVS (P = 0.03) suggesting diastolic dysfunction in HL survivors.

Conclusion

Cardiac dysfunction after childhood cancer therapy may develop after many years. Since systolic and diastolic dysfunction can be seen in these patients periodic echocardiographic screening of both systolic and diastolic function in the survivors of HL might be useful in the follow‐up of these patients. Pediatr Blood Cancer 2012; 58: 250–255. © 2011 Wiley Periodicals, Inc.
Preclinical evaluation of pemetrexed in pediatric solid tumors
Authors: Norris Robin E. , Rappaport Eric F. , Adamson Peter C.
Published: August 2011

Renewed interest in antifols for the treatment of childhood cancers has resulted from identification of novel antifols with broad spectrums of anti‐cancer activity. We evaluated the in vitro cytotoxicity of methotrexate and pemetrexed in a panel of 12 pediatric solid tumor cell lines using the sulforhodamine‐B assay. The Ewing sarcoma (ES) cell lines demonstrated the greatest sensitivity to both methotrexate and pemetrexed. Expression of folate pathway genes (DHFR, TS, GARFT, GGH) did not correlate with in vitro drug sensitivity. Further evaluation of pemetrexed for the treatment of ES is warranted. Pediatr Blood Cancer 2011; 57: 1233–1235. © 2011 Wiley Periodicals, Inc.
Major bleeding risk associated with warfarin and co‐medications in the elderly population
Authors: Vitry Agnes I. , Roughead Elizabeth E. , Ramsay Emmae N. , Preiss Adrian K. , Ryan Philip , Gilbert Andrew L. , Caughey Gillian E. , Shakib Sepehr , Esterman Adrian , Zhang Ying , McDermott Robyn A
Published: August 2011

Purpose

Warfarin management in the elderly population is complex as medicines prescribed for concomitant diseases may further increase the risk of major bleeding associated with warfarin use. We aimed to quantify the excess risk of bleeding‐related hospitalisation when warfarin was co‐dispensed with potentially interacting medicines.

Methods

A retrospective cohort study was undertaken over a 4‐year period from July 2002 to June 2006 to examine bleeding risk associated with medications co‐administered in patients taking warfarin using an administrative claims database from the Australian Department of Veterans' Affairs. All veterans aged 65 years and over who were new users of warfarin were followed until death or study end. Risk of bleeding was assessed using a Poisson GEE model adjusting for age, gender, socioeconomic status, co‐morbidity index, previous bleeding related hospitalisations and indicators of health service use.

Results

Overall, 17661 veterans who used warfarin at any time during the study period were included. The overall incidence rate of bleeding‐related hospitalisations was 4.1 (95% CI 3.7–4.6) per 100 person‐years in veterans who were not receiving potentially interacting medicines. Bleeding‐related hospitalisation rates were significantly increased when warfarin was co‐prescribed with low‐dose aspirin (Adjusted rate ratio (AdjRR) 1.44, 95% CI 1.00–2.07), clopidogrel (AdjRR 2.23, 95% CI 1.48–3.36), clopidogrel with aspirin (AdjRR 3.44, 95% CI 1.28–9.23), amiodarone (AdjRR 3.33, 95% CI 1.38–8.00) and antibiotics (AdjRR 2.34, 95% CI 1.55–3.54).

Conclusions

Models assessing bleeding risk with warfarin should take account of the range of potentially harmful medicine combinations used in elderly people with comorbid conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Functionalization of graphene oxide towards thermo‐sensitive nanocomposites via moderate in situ SET‐LRP
Authors: Deng Yan , Li Yongjun , Dai Jing , Lang Meidong , Huang Xiaoyu
Published: August 2011

A mild and efficient strategy is presented for growing thermo‐sensitive polymers directly from the surface of exfoliated graphene oxide (GO). This method involves the covalent attachment of Br‐containing initiating groups onto the surface of GO sheets followed by in situ growing poly[poly(ethylene glycol) ethyl ether methacrylate] (PPEGEEMA) via single‐electron‐transfer living radical polymerization (SET‐LRP). Considering the lack of reactive functional groups on the surface of GO, exfoliated GO sheets were subjected to an epoxide ring opening reaction with tris(hydroxymethyl) aminomethane (TRIS) at room temperature. The initiating groups were grafted onto TRIS‐GO sheets by treating hydroxyls with 2‐bromo‐2‐methylpropionyl bromide at room temperature. PPEGEEMA chains were synthesized by in situ SET‐LRP using CuBr/Me6TREN as catalytic system at 40 °C in H2O/THF. The resulting materials were characterized using a range of testing techniques and it was proved that polymer chains were successfully introduced to the surface of GO sheets. After grafting with PPEGEEMA, the modified GO sheets still maintained the separated single layers and the dispersibility was significantly improved. This TRIS‐GO‐PPEGEEMA hybrid material shows reversible self‐assembly and deassembly in water by switching temperature at about 34 °C. Such smart graphene‐based materials promise important potential applications in thermally responsive nanodevices and microfluidic switches. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Three different β‐cyclodextrins direct the emulsion copolymerization of a highly fluorinated methacrylate toward distinctive nanostructured particle morphologies
Authors: Yang Chengcheng , Castelvetro Valter , Scalarone Dominique , Bianchi Sabrina , Zhang Yongming
Published: August 2011

Stable colloidal dispersions of nanostructured semifluorinated acrylic particles with an unfluorinated core and an outer layer consisting of copolymers of the highly hydrophobic and lipophobic heptadecafluorodecyl methacrylate (FMA) were successfully synthesized with the assistance of three different cyclodextrins as phase‐transfer catalysts: β‐cyclodextrin (β‐CD), hydroxypropyl β‐cyclodextrin (HpCD), and methyl β‐cyclodextrin (MeCD). While all the cyclodextrins form a stable inclusion complex (IC) with FMA, only the ICs with the more hydrophilic HpCD and MeCD are soluble in water. Nevertheless, incorporation of FMA in the particle shell copolymer could be achieved also when using β‐CD. On the other hand, the morphology of the nanostructured particles was characterized by a “patchy” fluorinated shell dependent on the cyclodextrin used, the best results being obtained with MeCD. A monomer‐starved semicontinuous emulsion polymerization procedure was essential to favor the CD‐mediated incorporation of FMA into the copolymer structure and to achieve a stable colloidal dispersion even in the presence of small amounts of mixed anionic–nonionic surfactants. The thermal and surface properties of the latex films showed a good correlation with the shell composition and patchy nanostructured morphology of the particles. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
SET‐LRP of methyl acrylate catalyzed with activated Cu(0) wire in methanol in the presence of air
Authors: Nguyen Nga H. , Percec Virgil
Published: August 2011

Single electron transfer‐living radical polymerization (SET‐LRP) of methyl acrylate (MA) in methanol, catalyzed with nonactivated and activated Cu(0) wires, was performed in the presence of nondeoxygenated reagents and was investigated under a simple blanket of nitrogen. The addition of a small amount of hydrazine hydrate mediates the deoxygenation of the reaction mixture by the consumption of oxygen through its use to oxidize Cu(0) to Cu2O, followed by the reduction of Cu2O with hydrazine back to the active Cu(0) catalyst. SET‐LRP of MA in methanol in the presence of air requires a smaller dimension of Cu(0) wire, compared to the nonactivated Cu(0) wire counterpart. Activation of Cu(0) wire allowed the polymerization in air to proceed with no induction period, linear first‐order kinetics, linear correlation between the molecular weight evolution with conversion, and narrow molecular weight distribution. The retention of chain‐end functionality of α,ω‐di(bromo) poly(methyl acrylate) (PMA) prepared by SET‐LRP was demonstrated by a combination of experiments including 1H NMR spectroscopy and matrix‐assisted laser desorption ionization–time of flight mass spectrometry after thioetherification of α,ω‐di(bromo) PMA with thiophenol. In SET‐LRP of MA in the presence of limited air, bimolecular termination is observed only above 85% conversion. However, for bifunctional initiators, the small amount of bimolecular termination observed at high conversion maintains a perfectly bifunctional polymer. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Polymer nanocomposites for electrical energy storage
Authors: Wang Qing , Zhu Lei
Published: August 2011

This review highlights the frontier scientific research in the development of polymer nanocomposites for electrical energy storage applications. Considerable progress has been made over the past several years in the enhancement of the energy densities of the polymer nanocomposites via tuning the chemical structures of ceramic fillers and polymer matrix and engineering the polymer–ceramic interfaces. This article summarizes a range of current approaches to dielectric polymer nanocomposites, including the ferroelectric polymer matrix, increase of the dielectric permittivity using high‐permittivity ceramic fillers and conductive dopants, preparation of uniform composite films based on surface‐functionalized fillers, and utilization of the interfacial coupling effect. Primary attentions have been paid to the dielectric properties at different electric fields and their correlation with film morphology, chemical structure, and filler concentration. This article concludes with a discussion of scientific issues that remain to be addressed as well as recommendations for future research. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1421–1429, 2011
Modification of the electronic structure in single‐walled carbon nanotubes with aromatic amines
Authors: Dettlaff‐Weglikowska U. , Kim G. , Bulusheva L. G. , Roth S.
Published: August 2011

We investigated the interactions of two aromatic amines, N,N,N′N′‐tetramethyl‐p‐phenylenediamine (TMPD) and tetramethylpyrazine (TMP) with single‐walled carbon nanotube (SWNT) networks. Adsorption and intercalation of amine molecules in bundled SWNTs is expected to modify the electronic structure of nanotubes in a similar way as has already been observed for alkali metals. Our ab initio density functional calculations demonstrate that TMPD donates electron to the nanotube and produces donor‐like states below the conduction band whereas the effect of the TMP treatment is very weak. The electron transfer to the nanotubes has been supported experimentally by the XPS valence band spectra which show strongly modified spectral features. Especially an increase of the electronic density at the Fermi level upon adsorption of TMPD and TMP is clearly demonstrated. Rather intensive features between π* and σ* transitions in the NEXAFS spectrum of the pristine SWNTs attributed to the oxidized carbon functional groups are chemically modified upon adsorption of amines on the networks. This fact suggests that the aromatic amines evidently react with the defects, remove or replace oxygen species responsible for the p‐type doping of SWNTs, and therefore are acting as a de‐doping agent for the naturally p‐type doped semiconducting SWNTs.
Formation of MoS2 nanoparticles on the surface of reduced graphite oxide
Authors: Koroteev V. O. , Bulusheva L. G. , Okotrub A. V. , Yudanov N. F. , Vyalikh D. V.
Published: August 2011

MoS2 nanoparticles were formed on the graphitic surface by annealing of a mixture of amorphous MoS3 and reduced graphite oxide at 1000 °C in high‐vacuum conditions. High‐resolution transmission electron microscopy (HRTEM) revealed that the nanoparticles are ranged from 5 to 12 nm. The large variation in nanoparticle size resulted in optical absorbance of the composite within a 1.5–6.0 eV interval. From analysis of Raman and near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy data, development of covalent bonding between MoS2 nanoparticles and graphitic surface was proposed.

HRTEM of MoS2 nanoparticles ∼5–12 nm in size, deposited on reduced graphite oxide substrate.

magnified image
Pd/MWCNTs catalytic activity in the formic acid electrooxidation dependent on catalyst surface treatment
Authors: Mazurkiewicz Marta , Malolepszy Artur , Mikolajczuk Anna , Stobinski Leszek , Borodzinski Andrzej , Lesiak Beata , Zemek Josef , Jiricek Petr
Published: August 2011

The catalytic activity in the formic acid (HCOOH) electrooxidation reaction of the Pd multiwall carbon nanotubes (MWCNTs) supported catalyst, prepared by a microwave‐assisted polyol method, treated under different gas atmospheres, and temperatures (200 and 300 °C), was investigated. Their respective catalysts surface characterization proceeded in UHV using the electron spectroscopy methods. Content of constituents, i.e., Pd nanoparticles, C and O, was examined quantitatively. Content of Pd phases and chemical forms of C atoms was analyzed assuming respective binding energy (BE) values to Pd 3d and C 1s X‐ray photoelectron spectra (XPS) spectra fitted to Gaussian–Lorentzian components. Surface structure was examined from the 3D nanostructure analysis by quantitative analysis of surfaces by electron spectroscopy (QUASES). Catalytic activity of Pd/MWCNTs after various surface treatments was attributed to different surface content and forms of Pd nanoparticles, and PdOx/C overlayer morphology, coverage, and thickness.
The key role of diabatic processes in modifying the upper‐tropospheric wave guide: a North Atlantic case‐study
Authors: Grams Christian M. , Wernli Heini , Böttcher Maxi , Čampa Jana , Corsmeier Ulrich , Jones Sarah C. , Keller Julia H. , Lenz Claus‐Jürgen , Wiegand Lars
Published: August 2011

This study highlights the importance of diabatic processes for the complex interaction of weather systems in the North Atlantic–European sector during the week of 7–14 September 2008. A chain of events occurred including the extratropical transition (ET) of hurricane Hanna, a subsequently developing extratropical cyclone, the formation of an upper‐level potential vorticity (PV) streamer that protruded towards Europe and triggered intense rainfall, and the genesis of a Mediterranean cyclone. A PV perspective is adopted along with trajectory calculations to elucidate the diabatic modification of the midlatitude flow.

Important diabatic PV modifications occurred at upper levels, associated with the cross‐isentropic transport of low‐PV air within warm conveyor belts (WCBs). These were diagnosed during the ET of Hanna and the development of the extratropical cyclone near Newfoundland. The WCBs contributed to the amplification of ridges downstream of each cyclone and to the subsequent elongation of Hanna's upstream trough into a PV streamer. This streamer eventually triggered the Mediterranean cyclogenesis. The second major effect of the diabatic processes occurred on smaller scales, in the low and middle troposphere. The remnants of Hanna's tropical PV core advected moist air towards the baroclinic zone leading to condensational PV production in the lower troposphere. In contrast, in the case of the extratropical cyclone, diabatic PV production occurred within its WCB at mid levels. These diagnostic analyses corroborate the potential of diabatic processes associated with extratropical flow systems for the modification of both the low‐level vortices and the upper‐level Rossby wave guide. Copyright © 2011 Royal Meteorological Society
Influence of Mg2+, Ni2+, and Cu2+ on DNA assembly on HOPG surfaces: atomic force microscopy study
Authors: Zhao Lin , Liu Zhiguo , Zu Yuangang , Zhou Zhen , Sun Tongze
Published: August 2011

Adsorption of circular DNA onto bare highly oriented pyrolytic graphite (HOPG) surfaces by the addition of Mg2+, Ni2+, and Cu2+ has been investigated by atomic force microscopy (AFM). AFM results revealed that the topography and height of DNA on HOPG surface by the addition of different metal ions are quite different. After the addition of Mg2+ for incubation, DNA molecules tend to form many loops on HOPG surfaces, which are derived from the crossover of intramolecular and intermolecular chains. After the addition of Ni2+, DNA molecules can form network on HOPG surfaces, and the density of DNA network was significantly increased with increasing DNA concentration. Consequently, dense DNA network can be obtained by using relatively low concentration of DNA and Ni2+. As for the addition of Cu2+, angular DNA loops composed of flat chains were observed. The observed flat DNA chains with an average height of 0.52 nm can be ascribed to Cu2+ insert into the site between bases and phosphate group of DNA inducing denaturation of DNA molecules. This study is very helpful for understanding the interactions of metal ions and DNA molecules, and for constructing various DNA structures on the carbonaceous surfaces. SCANNING 34: 68–75, 2012. © 2011 Wiley Periodicals, Inc.
Multivariate meta‐analysis: A method to summarize non‐linear associations
Authors: Gasparrini A. , Armstrong B.
Published: August 2011

Multivariate meta‐analysis represents a promising statistical tool in several research areas. Here, we provide a brief overview of the application of this methodology to combining complex multi‐parameterized relationships, such as non‐linear or delayed associations, in multi‐site studies. The discussion focuses on the advantages over simpler univariate methods, estimation and computational issues and directions for further research. Copyright © 2011 John Wiley & Sons, Ltd.
Nonparametric multiple imputation for receiver operating characteristics analysis when some biomarker values are missing at random
Authors: Long Qi , Zhang Xiaoxi , Hsu Chiu‐Hsieh
Published: August 2011

The receiver operating characteristics (ROC) curve is a widely used tool for evaluating discriminative and diagnostic power of a biomarker. When the biomarker value is missing for some observations, the ROC analysis based solely on complete cases loses efficiency because of the reduced sample size, and more importantly, it is subject to potential bias. In this paper, we investigate nonparametric multiple imputation methods for ROC analysis when some biomarker values are missing at random and there are auxiliary variables that are fully observed and predictive of biomarker values and/or missingness of biomarker values. Although a direct application of standard nonparametric imputation is robust to model misspecification, its finite sample performance suffers from curse of dimensionality as the number of auxiliary variables increases. To address this problem, we propose new nonparametric imputation methods, which achieve dimension reduction through the use of one or two working models, namely, models for prediction and propensity scores. The proposed imputation methods provide a platform for a full range of ROC analysis and hence are more flexible than existing methods that primarily focus on estimating the area under the ROC curve. We conduct simulation studies to evaluate the finite sample performance of the proposed methods and find that the proposed methods are robust to various types of model misidentification and outperform the standard nonparametric approach even when the number of auxiliary variables is moderate. We further illustrate the proposed methods by using an observational study of maternal depression during pregnancy. Copyright © 2011 John Wiley & Sons, Ltd.
Public perceptions and governance of controversial technologies to tackle climate change: nuclear power, carbon capture and storage, wind, and geoengineering
Authors: Poumadère Marc , Bertoldo Raquel , Samadi Jaleh
Published: August 2011

The role carbon emissions play in contributing to climate change makes clear the necessity for a global reconsideration of current modes of energy production. In recent years, as concerns over the threats of climate change (CC) have become more acute, four technologies have notably risen to the forefront of academic and public discourse: nuclear power, carbon capture and storage (CCS), wind power, and geoengineering. The particular interest of these four approaches lies in the fact that they reflect both energy production and climate control technologies, are often socially controversial, and present complex challenges of governance. Nuclear and wind power both deserve an important place among the variety of low‐carbon energy options. In countries where public acceptance is evaluated, although, support for nuclear energy appears to be conditional upon simultaneous development of other renewable energies alongside a feasible plan to address the disposal of nuclear waste. The Fukushima accident sharply increased public concern about the safety and vulnerability of nuclear reactors. While wind power receives general public support, issues of accommodation can arise when it comes to siting wind farms. Persistent dependency upon carbon‐producing energy has made favorable the option of CCS. However, in addition to technical and geological factors, social resistance to the placement of carbon storage units remains a key obstacle. Geoengineering offers the technological capacity to directly act on the climate should levels of atmospheric CO2 become dangerously high. Public perception regarding the risk of climate change can be labile, and the alternatives reviewed here share the characteristic that their technical and political dimensions are intertwined. The variety of options for combining and implementing these technologies, coupled with the inherently time‐sensitive nature of CC, underscore the complexity of the endeavor. In order to bridge these various levels of analysis and decision making, and to better understand and integrate people's involvement, exercises in risk governance could be developed at both the national and international levels. WIREs Clim Change 2011 2 712–727 DOI: 10.1002/wcc.134

This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Social Amplification/Attenuation of Climate Risks

The Carbon Economy and Climate Mitigation > Policies, Instruments, Lifestyles, Behavior
Sea level and climate: measurements and causes of changes
Authors: Cazenave Anny , Remy Frédérique
Published: August 2011

We review present‐day observations of sea level change and variability at global and regional scales, focusing on the altimetry era starting in the early 1990s. Over the past ∼18‐years, the rate of global mean sea level rise has reached 3.3 ± 0.4 mm/year, nearly twice that of the previous decades, although the observed larger sea level rise rate may be influenced by decadal or longer variations in the ocean. Moreover, sea level rates are not geographically uniform; in some regions like the tropical western Pacific, rates are up to 3–4 times higher than the global mean rate. We next discuss the climate‐related components of the global mean sea level rise. Over the last ∼18‐years, ocean thermal expansion contributes about one third to the observed rise while total land ice (glacier melting plus ice sheet mass loss) contribute the other two third. The spatial trend patterns evidenced over the altimetry period mostly result from nonuniform steric sea level changes (effects of ocean temperature and salinity), largely caused by wind‐driven ocean circulation changes. Such patterns are not stationary but oscillate through time on decadal/multidecadal time scale, in response to natural modes of the coupled ocean‐atmosphere system. We close up this review by briefly discussing future (21st century) sea level rise. Current limited knowledge of the future evolution of the mass balance of the Greenland and Antarctica ice sheets leads to high uncertainty on the global mean sea level rise expected for the next 50–100 years. WIREs Clim Change 2011 2 647–662 DOI: 10.1002/wcc.139

This article is categorized under:

Paleoclimates and Current Trends > Earth System Behavior
Computing ro‐vibrational spectra of van der Waals molecules
Authors: Carrington Tucker , Wang Xiao‐Gang
Published: August 2011

This article reviews methods for computing ro‐vibrational spectra of van der Waals molecules. Due to the presence of large‐amplitude motion, calculations often play an important role in assigning and understanding the spectra of van der Waals molecules. Fortunately, it is possible to make usefully accurate calculations because important parts of the spectrum can be understood by doing calculations that omit the intramolecular coordinates. In this article, we present new ideas for deriving kinetic energy operators and discuss choosing basis functions and doing the matrix–vector products that are required to obtain a spectrum using the Lanczos algorithm. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 952–963 DOI: 10.1002/wcms.73

This article is categorized under:

Theoretical and Physical Chemistry > Spectroscopy
Substrate analysis of the Pneumocystis carinii protein kinases PcCbk1 and PcSte20 using yeast proteome microarrays provides a novel method for Pneumocystis signalling biology
Authors: Kottom Theodore J. , Limper Andrew H.
Published: August 2011

Pneumocystis carinii (Pc) undergoes morphological transitions between cysts and trophic forms. We have previously described two Pc serine/threonine kinases, termed PcCbk1 and PcSte20, with PcSte20 belonging to a family of kinases involved in yeast mating, while PcCbk1 is a member of a group of protein kinases involved in regulation of cell cycle, shape, and proliferation. As Pc remains genetically intractable, knowledge on specific substrates phosphorylated by these kinases remains limited. Utilizing the phylogenetic relatedness of Pc to Saccharomyces cerevisiae, we interrogated a yeast proteome microarray containing >4000 purified protein based peptides, leading to the identification of 18 potential PcCbk1 and 15 PcSte20 substrates (Z‐score > 3.0). A number of these potential protein substrates are involved in bud site selection, polarized growth, and response to mating α factor and pseudohyphal and invasive growth. Full‐length open reading frames suggested by the PcCbk1 and PcSte20 protoarrays were amplified and expressed. These five proteins were used as substrates for PcCbk1 or PcSte20, with each being highly phosphorylated by the respective kinase. Finally, to demonstrate the utility of this method to identify novel PcCbk1 and PcSte20 substrates, we analysed DNA sequence data from the partially complete Pc genome database and detected partial sequence information of potential PcCbk1 kinase substrates PcPxl1 and PcInt1. We additionally identified the potential PcSte20 kinase substrate PcBdf2. Full‐length Pc substrates were cloned and expressed in yeast, and shown to be phosphorylated by the respective Pc kinases. In conclusion, the yeast protein microarray represents a novel crossover technique for identifying unique potential Pc kinase substrates. Copyright © 2011 John Wiley & Sons, Ltd.
Accuracy of Macroscopic Intraoperative Diagnosis of Serosal Invasion and Risk of Over‐ and Underestimation in Gastric Carcinoma
Authors: Jeong Oh , Ryu Seong Yeop , Jeong Mi Ran , Sun Jang Won , Park Young Kyu
Published: August 2011

Background

Accurate intraoperative diagnosis of serosal invasion is a prerequisite for proper application of invasive procedures, such as intraperitoneal chemohyperthermia, for serosa positive gastric carcinomas.

Methods

We reviewed the prospectively constructed data of 1,265 gastric cancer patients who underwent surgery between 2007 and 2009. Accuracies of macroscopic diagnoses of serosal invasion were determined by comparing with pathological findings. The risk factors of over‐ and underestimation of serosal invasion were analyzed in the univariate and multivariate model.

Results

The accuracy of macroscopic intraoperative diagnosis of serosal invasion was 88%. Serosal invasion was underestimated in 34 of 187 serosa positive patients and overestimated in 117 of 1,078 serosa negative patients; a sensitivity and specificity of 82 and 89%, respectively. When pT1 tumors were excluded, the accuracy, sensitivity, and specificity of macroscopic diagnosis of serosal invasion were 71.5, 81.8, and 65.3%, respectively. Univariate and multivariate analysis revealed that a tumor size of >4 cm and preoperative CT finding of serosa positive were independent risk factors for macroscopic overestimation as serosal invasion in pT2 gastric cancer. Meanwhile, Borrmann type 1, preoperative CT finding of serosa negative, lesser/posterior surface location, and tumor size of <4 cm were independent risk factors for underestimation of serosal invasion in pT3 gastric carcinoma.

Conclusions

The macroscopic diagnosis of serosal invasion is largely consistent with pathological findings. However, great care should be taken with regard to the risk of over‐ and underestimation of serosal invasion when making a decision for invasive treatments based on macroscopic findings of serosal invasion.
Surgical Strategies for Management of the Open Abdomen
Authors: Regner Justin L. , Kobayashi Leslie , Coimbra Raul
Published: August 2011

Since the mid‐1990s the surgical community has seen a surge in the prevalence of open abdomens (OAs) reported in the surgical literature and in clinical practice. The OA has proven to be effective in decreasing mortality and immediate postoperative complications; however, it may come at the cost of delayed morbidity and the need for further surgical procedures. Indications for leaving the abdomen open have broadened to include damage control surgery, abdominal compartment syndrome, and abdominal sepsis. The surgical options for management of the OA are now more diverse and sophisticated, but there is a lack of prospective randomized controlled trials demonstrating the superiority of any particular method. Additionally, critical care strategies for optimization of the patient with an OA are still being developed. Review of the literature suggests a bimodal distribution of primary closure rates, with early closure dependent on postoperative intensive care management and delayed closure more affected by the choice of the temporary abdominal closure technique. Invariably, a small fraction of patients requiring OA management fail to have primary fascial closure and require some form of biologic fascial bridge with delayed ventral hernia repair in the future.
Pancreatic Cancer, Healthcare Cost, and Loss of Productivity: A Register‐based Approach
Authors: Tingstedt Bobby , Andersson Erik , Flink Anton , Bolin Kristian , Lindgren Björn , Andersson Roland
Published: August 2011

Background

Despite the fact that pancreatic cancer is the fourth leading cause of cancer‐related death, there is little empirical evidence on its direct healthcare costs and, especially, its indirect costs due to loss of production.

Methods

The present study is a retrospective analysis of all patients with pancreatic cancer (excluding endocrine cancer) in the primary catchment area of Lund University Hospital, Sweden, during the period 2005–2007. Detailed information on all diagnostic and therapeutic investigations, interventions, and postoperative course and long‐term follow‐up was collected, as well as absenteeism from work due to the health problem, from which direct costs were calculated. The indirect costs for loss of production due to sickness and premature death were calculated by the human capital method. A total of 83 patients were included, for an incidence rate of 9.9 patients/100,000 inhabitants.

Results

Direct treatment cost per pancreatic‐cancer patient was estimated at EUR 16,066 for each patient’s remaining lifetime. Hospitalization accounted for the major expenditure—60% of the lifetime treatment cost. Patients with resectable tumor had a mean cost of EUR 19,809; locally advanced disease, EUR 14,899; and metastatic disease, €16,179. Younger patients and men had a higher than average lifetime treatment cost. The loss of productivity was estimated at EUR 287,420 per patient younger than 65 years of age, of which premature mortality accounted for 79%.

Conclusions

Adding the cost of palliative care estimated in a previous Swedish study, health‐care costs and productivity losses for pancreatic cancer would add up to a substantial economic burden for Sweden at large in 2009 (population 9.1 million), between EUR 86 million and EUR 93 million.
Ten Years After Arterial Bypass Surgery for Claudication: Venous Bypass is the Primary Procedure for TASC C and D Lesions
Authors: Eugster Thomas , Marti Regula , Gurke Lorenz , Stierli Peter
Published: August 2011

Background

The appropriate role for surgery and endovascular therapy for severe intermittent claudication (IC) remains controversial. We present our results after infrainguinal autogenous bypass for severe IC more than 10 years ago giving a reasoned argument to perform vein bypass as the primary procedure for severe IC.

Methods

Our prospectively designed database includes more than 1,000 infrainguinal bypasses following an all‐autogenous policy. For this review only patients operated on for severe IC at least 10 years ago were included. The primary end points were survival and primary and assisted‐primary patency rates.

Results

From October 1988 until December 2000, 124 bypasses for IC were performed. Ninety‐five patients were male and the mean age was 64.5 ± 10.8 years. Survival after 10 years was 50.3% according to life table analysis. Forty bypasses were to the supragenicular artery, 62 to the infragenicular popliteal artery, and 22 to the tibial artery. Thirty‐day mortality was 0.8% (1 patient). The primary patency rate after 10 years was 63.5% and the assisted‐primary patency rate 87.3%.

Conclusion

Infrainguinal venous bypass for severe IC has excellent long‐term results. Our results are strong arguments against the liberal use of stenting long lesions of the femoropopliteal artery. Venous bypass remains the primary procedure for TASC C and D lesions in claudicants.
Money, organization and the state: The partial cartelization of party politics in Slovenia
Authors: Krašovec Alenka , Haughton Tim
Published: August 2011

A detailed analysis of party organization, party funding and voting behaviour in parliament in Slovenia indicates a partial cartelization of Slovene party politics. In line with the cartel thesis, parties in Slovenia are heavily dependent on the state for their finances and there is evidence that parties have used the resources of the state to limit competition. Nonetheless, there is much less evidence of cartelization in terms of party organization indicating more cartelization in the party system as a whole than within individual parties.
Weakly s-supplementally embedded minimal subgroups of finite groups
Authors: Zhao Tao , Li Xianhua , Xu Yong
Published: August 2011

Suppose that G is a finite group and H is a subgroup of G. We call H a weakly s-supplementally embedded subgroup of G if there exist a subgroup T of G and an s-quasinormally embedded subgroup Hse of G contained in H such that G = HT and H ∩ T ≤ Hse. We investigate the influence of the weakly s-supplementally embedded property of some minimal subgroups on the structure of finite groups. As an application of our results, some earlier results are generalized.