bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of pneumonia hospital admissions in a primary care electronic medical record database
Authors: Meropol Sharon B. , Metlay Joshua P.
Published: February 2012

Purpose

When using electronic medical record data to study drug use, hospitalizations are markers of severe outcomes. To identify events within a specified time window, it is important to validate hospitalization diagnoses and dates. Our objective was to validate pneumonia hospitalizations and their dates identified using hospitalization codes in The Health Improvement Network (THIN), a UK primary care electronic medical record.

Methods

This cross‐sectional study used a cohort of THIN adult visits for acute nonspecific respiratory infections from June 1985 to August 2006. Pneumonia hospitalizations within 30 days after the visit were identified using THIN diagnosis and hospitalization codes; 60 participants were randomly selected for validation. Patients' general practitioners (GPs) returned de‐identified hospital summaries and consultants' letters regarding overnight hospitalizations within a 180‐day window around the THIN hospitalization. Positive predictive value (PPV) was the number of GP‐validated hospitalizations divided by THIN documented hospitalizations.

Results

GPs returned 59 of 60 patient records; 52 had confirmed hospitalizations. PPV of THIN hospitalization documentation was 88% (95%CI = 77–95). One admission was not for pneumonia; PPV of THIN‐documented pneumonia admission was 86% (95%CI = 75–94). Of 52 valid THIN hospitalizations, 50 were actually admitted within 14 days of the documented THIN date (range = −2 to +18). The absolute median difference between THIN and validated admission dates was +0.5 days, and the absolute mean difference was +3.1 days. In 16 of 52 admitted patients, the THIN admission date was the actual discharge date.

Conclusions

THIN hospitalization codes performed well in identifying acute pneumonia hospitalizations and their timing. Admission date validity might be better for conditions associated with shorter versus longer hospitalizations. Copyright © 2012 John Wiley & Sons, Ltd.
Progress in development of epoxy resin systems based on wood biomass in Japan
Authors: Koike Tsuneo
Published: February 2012

This article reviews the progress in the development of wood biomass origin epoxy resin system from 1960s to recent years in Japan. The methods of using wood biomass for epoxy resin systems are classified into the following three categories; one is the method of preparing lignin‐epoxy resins after applying treatments on the industrial lignin, which has been disposed in large volume, another is that of using wood as the raw material of epoxy resin system after applying treatments directly on wood, and the other is that of composing epoxy resin and/or curing agent from woody raw materials (except the industrial lignin), which are isolated and refined from wood before the treatments. Although several promising technologies have been developed and tried to be industrialized in Japan, the full‐fledged development of wood biomass‐based epoxy resin has just started when viewed as a whole. These developments will be further accelerated toward the construction of the environment harmony type and the resources circulation type societies. As the result of continuous developmental efforts, it is expected that we can look at the scene where epoxy resins are sustainably supplied in various forms even after the depletion of oil resources. POLYM. ENG. SCI.,, 2012. © 2012 Society of Plastics Engineers
Ratcheting up protein translocation with anthrax toxin
Authors: Feld Geoffrey K. , Brown Michael J. , Krantz Bryan A.
Published: February 2012

Energy‐consuming nanomachines catalyze the directed movement of biopolymers in the cell. They are found both dissolved in the aqueous cytosol as well as embedded in lipid bilayers. Inquiries into the molecular mechanism of nanomachine‐catalyzed biopolymer transport have revealed that these machines are equipped with molecular parts, including adjustable clamps, levers, and adaptors, which interact favorably with substrate polypeptides. Biological nanomachines that catalyze protein transport, known as translocases, often require that their substrate proteins unfold before translocation. An unstructured protein chain is likely entropically challenging to bind, push, or pull in a directional manner, especially in a way that produces an unfolding force. A number of ingenious solutions to this problem are now evident in the anthrax toxin system, a model used to study protein translocation. Here we highlight molecular ratchets and current research on anthrax toxin translocation. A picture is emerging of proton‐gradient‐driven anthrax toxin translocation, and its associated ratchet mechanism likely applies broadly to other systems. We suggest a cyclical thermodynamic order‐to‐disorder mechanism (akin to a heat‐engine cycle) is central to underlying protein translocation: peptide substrates nonspecifically bind to molecular clamps, which possess adjustable affinities; polypeptide substrates compress into helical structures; these clamps undergo proton‐gated switching; and the substrate subsequently expands regaining its unfolded state conformational entropy upon translocation.
Formyl‐coenzyme A (CoA):oxalate CoA‐transferase from the acidophile Acetobacter aceti has a distinctive electrostatic surface and inherent acid stability
Authors: Mullins Elwood A. , Starks Courtney M. , Francois Julie A. , Sael Lee , Kihara Daisuke , Kappock T. Joseph
Published: February 2012

Bacterial formyl‐CoA:oxalate CoA‐transferase (FCOCT) and oxalyl‐CoA decarboxylase work in tandem to perform a proton‐consuming decarboxylation that has been suggested to have a role in generalized acid resistance. FCOCT is the product of uctB in the acidophilic acetic acid bacterium Acetobacter aceti. As expected for an acid‐resistance factor, UctB remains folded at the low pH values encountered in the A. aceti cytoplasm. A comparison of crystal structures of FCOCTs and related proteins revealed few features in UctB that would distinguish it from nonacidophilic proteins and thereby account for its acid stability properties, other than a strikingly featureless electrostatic surface. The apparently neutral surface is a result of a “speckled” charge decoration, in which charged surface residues are surrounded by compensating charges but do not form salt bridges. A quantitative comparison among orthologs identified a pattern of residue substitution in UctB that may be a consequence of selection for protein stability by constant exposure to acetic acid. We suggest that this surface charge pattern, which is a distinctive feature of A. aceti proteins, creates a stabilizing electrostatic network without stiffening the protein or compromising protein–solvent interactions.
Link adaptation for Ka band low Earth orbit Earth Observation systems: A realistic performance assessment
Authors: Toptsidis Nikolaos , Arapoglou Pantelis‐Daniel , Bertinelli Massimo
Published: February 2012

In this paper, a proposal is sketched for realizing high data rate downlinks in next‐generation Ka band low Earth orbit (LEO) Earth Observation (EO) systems. The work aims at realistically assessing the throughput advantage stemming from link adaptation strategies—embraced by most wireless and satellite communication standards—compared with non‐adaptive transmission, which is the approach followed in conventional X band EO systems. The transmission strategies examined include constant, (static and dynamic) variable, and adaptive flavors of coding and modulation, each representing a different performance/system complexity trade‐off. Practicality is pursued to the extent possible by incorporating state‐of‐the‐art orbital, ground station, spacecraft, propagation, physical layer, and system implementation characteristics. The results manifest that under particular conditions, link adaptation offers throughput improvements of up to 100% against non‐adaptive transmission schemes in Ka band LEO EO systems. Copyright © 2012 John Wiley & Sons, Ltd.
A graph‐theoretic framework for isolating botnets in a network
Authors: Jaikumar Padmini , Kak Avinash C.
Published: February 2012

We present a new graph‐based approach for the detection and isolation of botnets in a computer network. Our approach depends primarily on the temporal co‐occurrences of malicious activities across the computers in a network and is independent of botnet architectures and the means used for their command and control. As practically all aspects of how a botnet manifests itself in a network—such as the online bot population, bot lifetimes, and the duration and the choice of malicious activities ordered by the bot master—can be expected to vary significantly with time, our approach includes mechanisms that allow the graph representing the infected computers to evolve with time. With regard to how such a graph varies with time, of particular importance are the edge weights that are derived from the temporal co‐occurrences of malicious activities at the endpoints of the edges. A unique advantage of our graph‐based representation of the infected computers is that it allows us to use graph‐partitioning algorithms to separate out the different botnets when a network is infected with multiple botnets at the same time. We have validated our approach by applying it to the isolation of simulated botnets, with the simulations based on a new unified temporal botnet model that incorporates the current best understanding about how botnets behave, about the lifetimes of bots, and about the growth and decay of botnets. We also validate our algorithm on real network traces. Our results indicate that our framework can isolate botnets in a network under varying conditions with a high degree of accuracy. Copyright © 2012 John Wiley & Sons, Ltd.
Comparison of surface segregation and anticoagulant property in block copolymer blended evaporation and phase inversion membranes
Authors: Ran Fen , Nie Shengqiang , Lu Yi , Cheng Chong , Wang Dongsheng , Sun Shudong , Zhao Changsheng
Published: February 2012

In our recent study, an ABA amphiphilic triblock copolymer poly(vinyl pyrrolidone)‐b‐poly(methyl methacrylate)‐b‐poly(vinyl pyrrolidone) (PVP‐b‐PMMA‐b‐PVP) was synthesized and directly blended with polyethersulfone (PES) to prepare membranes. To further investigate the effects of surface energy and miscibility on the near‐surface composition profile of the membranes, evaporation membrane and phase inversion membrane of PES/PVP‐b‐PMMA‐b‐PVP were prepared by evaporating the solvent in a vacuum oven, and by a liquid–liquid phase separation technique, respectively. The surface composition and morphology of the membranes were investigated using XPS and tapping mode atomic force microscopy, and the surface segregations of the membranes were compared and discussed. For the evaporation membrane, PVP blocks were buried below the lower surface energy PMMA blocks and PES substrate at the airside surface. For the phase inversion membrane, however, the hydrophilicity of PVP blocks were the biggest driving force because of the high speed exchange between water and solvent, and present at the membrane surface. Thus, the modified PES membrane prepared by using phase inversion method has a layer of PVP block brushes on its surface and has the better anticoagulant property, which might improve the blood compatibility of the membrane and has potential to be used in blood purification. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of annealing on the molecular orientation in polytetrafluoroethylene thin films
Authors: Kobayashi Eiichi , Okudaira Koji K. , Okajima Toshihiro
Published: February 2012

The effects of annealing on the molecular orientation in polytetrafluoroethylene (PTFE) thin films evaporated on copper and silicon plates were studied using F K‐edge near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy. The intensity of the F 1 s → σ*(C‐F) transition in the NEXAFS spectrum from a non‐annealed PTFE thin film on a copper plate at a glancing X‐ray incidence angle was stronger than that at the normal incidence angle. For a thin film annealed at ~250 °C in a nitrogen atmosphere, the σ*(C‐F) peak intensity at the glancing angle was weaker than that at a normal angle. The F K‐edge NEXAFS spectra of a thin film annealed at ~350 °C showed a weakening dependence on the X‐ray incidence angle. This result indicates that the molecules in a PTFE thin film are increasingly oriented normal to the substrate surface with increasing annealing temperature and are oriented randomly. Copyright © 2012 John Wiley & Sons, Ltd.
Relative ion yields in mammalian cell components using C60 SIMS
Authors: Keskin Selda , Piwowar Alan , Hue Jonathan , Shen Kan , Winograd Nicholas
Published: February 2012

Time of flight secondary ion mass spectrometry has been used to better understand the influence of molecular environment on the relative ion yields of membrane lipid molecules found in high abundance in a model mammalian cell line, RAW264.7. Control lipid mixtures were prepared to simulate lipid–lipid interactions in the inner and outer leaflet of cell membranes. Compared with its pure film, the molecular ion yields of 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine and 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine are suppressed when mixed with 2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine. In the mixture, proton competition between 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine, 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine, and 2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine led to lower ionization efficiency. The possible mechanism for ion suppression was also investigated with 1H and 13C nuclear magnetic resonance spectroscopy. The formation of a hydroxyl bond in lipid mixtures confirms the mechanism involving proton exchange with the surrounding environment. Similar effects were observed for lipid mixtures mimicking the composition of the inner leaflet of cell membranes. The secondary molecular ion yield of 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phospho‐l‐serine was observed to be enhanced in the presence of 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphoethanolamine. Copyright © 2012 John Wiley & Sons, Ltd.
Surface characterization of biological nanodomains using NP‐ToF‐SIMS
Authors: Fernandez‐Lima F. A. , DeBord J. D. , Schweikert E. A. , Della‐Negra S. , Kellersberger K. A. , Smotherman M.
Published: February 2012

This paper describes the application of nanoparticle bombardment with time‐of‐flight secondary ion mass spectrometry (NP‐ToF‐SIMS) for the analysis of native biological surfaces for the case of sagittal sections of mammalian brain tissue. The use of high energy, single nanoparticle impacts (e.g. 520 keV Au400) permits desorption of intact lipid molecular ions, with enhanced molecular ion yield and reduced fragmentation. When coupled with complementary molecular ion fragmentation and exact mass measurement analysis, high energy nanoparticle probes (e.g. 520 keV Au400 NP) provide a powerful tool for the analysis of the lipid components from native brain sections without the need for surface preparation and with ultimate spatial resolution limited to the desorption volume per impact (~103 nm3). Copyright © 2012 John Wiley & Sons, Ltd.
Sputtered ion emission under size‐selected Arn+ cluster ion bombardment
Authors: Gnaser Hubert , Ichiki Kazuya , Matsuo Jiro
Published: February 2012

The emission of positive secondary ions from four amino acids (arginine, glycine, phenylalanine, and tyrosine) and from NaCl under irradiation with large Arn+ cluster ions was investigated by time‐of‐flight secondary ion mass spectrometry. Size‐selected 5.5‐keV Arn+ cluster ions with 300 ≤ n ≤ 2000 were used, and the flux of sputtered positive ions was monitored as function of cluster size n. For all cluster sizes, the protonated or the cationized molecular ions are observed in the mass spectra. In addition, the results show that with increasing cluster size, the number of fragment molecules strongly decreases in relation to the intact molecules, to the extent that the ratio of fragment to intact ions is 10% or less for the largest cluster ions. Generally, the ion yields Y+ were found to decrease for decreasing impact energy per cluster atom, E/n, and this attenuation was recorded down to values as low as E/n ~ 3 eV/atom. The general trend of Y+ versus E/n is similar for all targets and appears to follow a power‐law dependence, Y+ ∝ (E/n)x, with x ~ 4. This pronounced yield change could be ascribed to a reduction of the ionization probability which is envisaged to depend on the presence of free protons. Their number is expected to decrease concurrently with the decreasing amount of fragmentation for large cluster ions (i.e. for low energies/atom). Copyright © 2012 John Wiley & Sons, Ltd.
An in situ chemical reaction approach to synthesize zinc picrate energetic thin film upon zinc oxide nanowires array
Authors: Zhang Wenchao , Peng Hongzheng , Gao Xiangdong , Ye Jiahai , Zhang Zhongyuan , Chao Yimin
Published: February 2012

Nanoenergetic materials are the key to great advances in microscale energy‐demanding systems as actuation part, igniter, propulsion unit, and power. An important challenge of energetic materials for microelectromechanical system (MEMS) is the compatibility of standard microsystem techniques with technology process employed in preparing energetic materials producing a large amount of gas and heat. Picric acid is known to react with metals to form highly unstable metallic picrate, which are often employed as explosive materials. In this study, films of zinc picrate were successfully produced with an ‘in‐situ chemical reaction’ method by introducing picric acid onto a ZnO nanowire array, which is fully compatible with technology for MEMS. The films were characterized by nuclear magnetic resonance, X‐ray diffraction, XPS, and SEM. The results demonstrate that picric acid reacted with ZnO to form zinc picrate thin film. Differential scanning calorimetry and thermogravimetric analysis measurements show that zinc picrate/ZnO films exhibit producing a large amount of gas, high energy output and lower ignition temperature, which will enhance the diversity of functions on MEMS devices. Therefore, this will open the door to integrate this traditional organic energetic material into microsystem, leading to new generation of MEMS devices. Copyright © 2012 John Wiley & Sons, Ltd.
Low (linear) teacher effect on student achievement in pre‐academic physics education
Authors: Cottaar Alice
Published: February 2012

This study investigates the effect of physics education on students' achievement in a large‐scale quantitative study of pre‐academic high school students throughout the Netherlands. Two aspects of teacher characteristics as perceived by their students are included: their “pleasantness” principally defined by their perceived friendliness and positive feedback and their “centeredness” principally defined by the perceived teacher centeredness in the lessons. Furthermore, this study includes four student aspects: their “general capability,” their “quantity of work,” their “quality of work,” and their “interest in the lessons.” Structural Equation Modeling is used in order to cluster the different variables defining the perceived pleasantness and the perceived centeredness of the teacher and the general capability, interest, and learning attitudes of the students. Furthermore, interrelations among these components and students' achievement are analyzed. Eventually, a very large effect of the students' general capability (61–72%) and a remarkably smaller effect of the remaining parameters (<3%) on achievement are detected. However, one should not yet conclude that teacher effect on high‐achieving‐students' achievement is consistently low. To the contrary, these results should be seen as an incentive to consider nonlinear effects, to vary ones viewpoint and to include more/other variables. In spite of the almost negligible correlation between the measured aspects of the physics teachers and achievement, the correlations between the teacher variables and the remaining student variables are quite significant. Both the perceived pleasantness and the centeredness of the teachers have a significant effect on the interest of their students. Furthermore, the pleasantness of the teacher correlates with the quality of the students' work and the centeredness of the teacher with their quantity of work. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 465–488, 2012
Abnormal gyration of the temporal lobe and megalencephaly are typical features of thanatophoric dysplasia and can be visualized prenatally by ultrasound
Authors: Blaas H.‐G. K. , Vogt C. , Eik‐Nes S. H.
Published: February 2012

Autopsies of fetuses with thanatophoric dysplasia (TD) have shown abnormal gyration of the temporal lobes. In addition, the head is relatively large compared with the abdomen. We evaluated by ultrasound six consecutive cases of TD at 19 + 0 to 19 + 6 gestational weeks based on last menstrual period. We observed abnormal and deep transverse sulci in the temporal lobes in all cases; these features were confirmed at autopsy. We performed biometric assessment, including biparietal diameter (BPD) and mean abdominal diameter (MAD). For each MAD value in the TD fetuses, we computed mean and SD of the corresponding BPD values from a population‐based registry in the relevant age range, and used them to calculate Z‐scores for each BPD/MAD ratio. In the general population, the average BPD/MAD ratio was 1.05. In the TD fetuses, the mean BPD was 51.5 (range, 49–54) mm, the MAD was 45 (range, 41–47) mm and the BPD/MAD ratio was 1.15 (range, 1.09–1.20). The average Z‐score of the ratios for TD fetuses was 2.44 (range, 1.05–3.39). The ratios for the TD fetuses were significantly higher than were the population ratios (P = 0.016). At autopsy, the mean brain‐to‐body weight ratio was 20.6% (range, 15.4–24.1%), which was greater than the corresponding mean ratio of 14.9% in normal fetuses. We conclude that abnormal and deep transverse gyration of the temporal lobes can be visualized by ultrasound in mid‐second‐trimester fetuses with TD. Due to megalencephaly, fetuses with TD have significantly different body proportions, with a larger BPD compared with normal fetuses. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Polarized climates: the distinctive histories of climate change and politics in the Arctic and Antarctica since the beginning of the Cold War
Authors: Luedtke Brandon , Howkins Adrian
Published: February 2012

This paper suggests that the Polar Regions are excellent places for thinking about historical interactions between climate change, science, and politics from the beginning of the Cold War up to the present. Since the second half of the 1940s, science has played a central role in contesting claims to political authority in both the Arctic and the Antarctic. Research conducted in the Polar Regions has made a major contribution to the science of climate change on a global scale, and research agendas have been closely connected in the two regions. Viewed from a comparative perspective, however, the historical experiences of global warming in the Arctic and Antarctica have been quite different. Climate research has suggested that warming is generally happening faster over much of the Arctic than the Antarctic. In addition, the recent histories of the two regions show that climate change in the Arctic is destabilizing politics there, whereas in Antarctica climate change is helping to reinforce the existing political structures framed by the Antarctic Treaty System (ATS). A comparative approach to the history of climate change in the Polar Regions helps to demonstrate that science, politics, and environmental change have each played important roles without making any single factor deterministic. WIREs Clim Change 2012, 3:145–159. doi: 10.1002/wcc.161

This article is categorized under:

Climate, History, Society, Culture > World Historical Perspectives

Trans‐Disciplinary Perspectives > Regional Reviews
The development of causal reasoning
Authors: Kuhn Deanna
Published: February 2012

How do inference rules for causal learning themselves change developmentally? A model of the development of causal reasoning must address this question, as well as specify the inference rules. Here, the evidence for developmental changes in processes of causal reasoning is reviewed, with the distinction made between diagnostic causal inference and causal prediction. Also addressed is the paradox of a causal reasoning literature that highlights the competencies of young children and the proneness to error among adults. WIREs Cogn Sci 2012, 3:327–335. doi: 10.1002/wcs.1160

This article is categorized under:

Psychology > Learning
Small molecule screening in zebrafish: swimming in potential drug therapies
Authors: Tamplin Owen J. , White Richard M. , Jing Lili , Kaufman Charles K. , Lacadie Scott A. , Li Pulin , Taylor Alison M. , Zon Leonard I.
Published: February 2012

Phenotype‐driven chemical genetic screens in zebrafish have become a proven approach for both dissection of developmental mechanisms and discovery of potential therapeutics. A library of small molecules can be arrayed into multiwell plates containing zebrafish embryos. The embryo becomes a whole organism in vivo bioassay that can produce a phenotype upon treatment. Screens have been performed that are based simply on the morphology of the embryo. Other screens have scored complex phenotypes using whole mount in situ hybridization, fluorescent transgenic reporters, and even tracking of embryo movement. The availability of many well‐characterized zebrafish mutants has also enabled the discovery of chemical suppressors of genetic phenotypes. Importantly, the application of chemical libraries that already contain FDA‐approved drugs has allowed the rapid translation of hits from zebrafish chemical screens to clinical trials. WIREs Dev Biol 2012, 1:459–468. doi: 10.1002/wdev.37

This article is categorized under:

Technologies > Perturbing Genes and Generating Modified Animals
Ink4‐Arf locus in cancer and aging
Authors: Sherr Charles J.
Published: February 2012

Three tumor suppressor genes at the small (<50 kb) INK4‐ARF (CDKN2A/B) locus on human chromosome 9p21 coordinate a signaling network that depends on the activities of the retinoblastoma (RB) protein and the p53 transcription factor. Disruption of this circuitry, frequently by codeletion of INK4‐ARF, is a hallmark of cancer, begging the question of why the intimate genetic linkage of these tumor suppressor genes has been maintained in mammals despite the risk of their coinactivation. The INK4‐ARF locus is not highly expressed under normal physiologic conditions in young mammals, but its induction becomes more pronounced as animals age. Notably, INK4‐ARF is actively silenced en bloc in embryonic, fetal, and adult stem cells but becomes poised to respond to oncogenic stress signals as stem cells lose their self‐renewal capacity and differentiate, thereby providing a potent barrier to tumor formation. Epigenetic remodeling of the locus as a whole provides a mechanism for coordinating the activities of RB and p53. A hypothesis is that the INK4‐ARF locus may have evolved to physiologically restrict the self‐renewal capacities and numbers of stem and progenitor cells with the attendant consequence of limiting tissue regenerative capacity, particularly as animals age. Deletion of INK4‐ARF contributes to the aberrant self‐renewal capacity of tumor cells and occurs frequently in many forms of human cancer. WIREs Dev Biol 2012 doi: 10.1002/wdev.40

For further resources related to this article, please visit the WIREs website.
Structure–activity relationships of serotonin 5‐HT2A agonists
Authors: Nichols David E.
Published: February 2012

Of the 14 known types of serotonin receptors one of the most extensively studied is the 5‐HT2A (5‐hydroxytryptamine) receptor. In the brain, this receptor plays a key role in regulation of cortical function and cognition, appears to be the principal target for the hallucinogenic/psychedelic drugs such as lysergic acid diethylamide (LSD), and also is a target for the newest atypical antipsychotic agents, which are antagonists or inverse agonists at this site. Among the structure–activity relationships that are known for this receptor type, there are three chemical classes of agonists: tryptamines, ergolines, and phenethylamines. Important structural features are identified for agonist activity and some of these agonists have features in common. In addition to effects at the receptor will be the focus, these drugs are also hallucinogenic (psychedelic) agents, and much of the SAR was developed on the basis of effects in humans, before modern pharmacological techniques were available. A certain amount of our knowledge therefore relies on those human studies. WIREs Membr Transp Signal 2012, 1:559–579. doi: 10.1002/wmts.42

For further resources related to this article, please visit the WIREs website.
A Pyrazole‐Expanded EDTA Ligand and its Pentanuclear Iron(III) Complex
Authors: Fischer Stefan , Demeshko Serhiy , Dechert Sebastian , Meyer Franc
Published: February 2012

A new ligand H5L has been synthesized that is composed of a central pyrazole bridging unit with two iminodiacetate chelate arms, thus providing two potentially tetradentate {N2O2} binding pockets. Its pentanuclear ferric complex [L2Fe5(μ3‐O)2(μ‐OH)2(py)2(H2O)2]– (1) was obtained under aerobic conditions and characterized by X‐ray crystallography as well as Mößbauer spectroscopy. SQUID data suggest the presence of competing spin interactions and an S = 5/2ground state, which is discussed in the light of the structural features. The new ligand H5L appears to be suitable for producing a variety of new multinuclear oxo‐ and hydroxo‐bridged iron(III) aggregates and for stabilizing high‐valent diiron cores.
Esophagogastroduodenoscopy in a Public Referral Hospital in Lilongwe, Malawi: Spectrum of Disease and Associated Risk Factors
Authors: Wolf Lindsey L. , Ibrahim Rahim , Miao Changchun , Muyco Arturo , Hosseinipour Mina C. , Shores Carol
Published: February 2012

Background

Esophagogastroduodenoscopy (EGD) is a valuable tool for diagnosing and treating upper gastrointestinal disease. Prioritizing the use of EGD in resource‐limited settings must be customized to local populations to maximize population benefit from the examination.

Methods

Cross‐sectional, retrospective review of EGD reports was conducted at Kamuzu Central Hospital (KCH), Lilongwe, Malawi. Esophageal tumors were defined as obstructive or nonobstructive and esophageal varices were graded on a scale of I to IV. Descriptive statistics were calculated and logistic regression performed for each disease state compared with all other reports.

Results

A total of 1,034 cases were reviewed (56% male; mean age (standard deviation), 44 (17) years). The most common indications were dysphagia (37%), hematemesis (21%), and epigastric pain (16%). The most common diagnoses were normal (36%), esophageal cancer (27%), and esophageal varices (17%). Eighty‐six percent of esophageal tumors were obstructive and 45% of esophageal varices were grade III or IV. Normal examinations were more likely to be female, younger, and present with dyspepsia. Esophageal cancers were more likely to be male, older, present with dysphagia, and present from districts outside Lilongwe. Esophageal varices were more likely to present with hematemesis.

Conclusions

EGD is a limited resource at KCH; patient selection should be guided by patient age and indication. The high burden of esophageal cancer and varices in Malawi suggests that therapeutic endoscopy would be beneficial.
Role of Caudate Lobectomy in Type IIIA and IIIB Hilar Cholangiocarcinoma: A 15‐year Experience in a Tertiary Institution
Authors: Kow Alfred Wei‐Chieh , Wook Choi Dong , Song Sun Choon , Kim Woo Seok , Kim Min Jung , Park Hyo Jun , Heo Jin Soek , Choi Seong Ho
Published: February 2012

Background

Concomitant liver resection for type III hilar cholangiocarcinoma could improve the R0 resection rate and long‐term outcome. In the present study, we examine the specific role of caudate lobectomy in liver resection for type IIIA and IIIB hilar cholangiocarcinoma and the prognostic factors for survival in this group of patients.

Methods

We reviewed all patients with type IIIA and IIIB hilar cholangiocarcinoma who underwent liver resection in Samsung Medical Center from January 1995 to July 2010. Patients were divided into those with and without caudate lobectomy (CL). The log rank test and Cox regression analysis were employed to investigate for prognostic factors of survival.

Results

There were 127 patients in this cohort, 57 without CL (44.9%) and 70 with CL (55.1%). The demographics and symptoms of presentation were comparable. The median preoperative bilirubin level was significantly higher in the group undergoing CL (p = 0.017). Patients with CL had a significantly better overall survival (OS) (CL: 64.0 months vs without CL: 34.6 months) (p = 0.010) and disease‐free survival (DFS) (CL: 40.5 months vs without CL: 27.0 months) (p = 0.031). Multivariate analysis showed that presence of symptoms (p = 0.025) and positive lymph node (LN) metastasis (p < 0.001) were negative prognostic factors for OS. Furthermore, multivariate analysis for DFS found that caudate lobectomy (p = 0.016) and positive LN metastasis (p = 0.001) were positive and negative prognostic factors, respectively.

Conclusions

Caudate lobectomy contributed to improvement of DFS and OS in type III hilar cholangiocarcinoma. Other prognostic factors include positive LN metastasis and presence of symptoms.
Short Bowel Syndrome: A Practical Pathway Leading to Successful Enteral Autonomy
Authors: Ba’ath M. E. , Almond S. , King B. , Bianchi A. , Khalil B. A. , Morabito A.
Published: February 2012

Background

Short bowel syndrome is a multisystemic disorder that results from the loss of a significant amount of small bowel. The goal of treatment in these patients is to achieve complete enteral autonomy while minimizing complications. Our unit has 30 years of experience in the management of short gut patients. During the past decade, our results have improved significantly, especially in children with severe short bowel syndrome. This brief communication looks at the algorithm presently used in our unit.

Methods

In this communication, the principles in management of short bowel syndrome in our unit are discussed. In addition, our algorithm is published for the first time. A brief summary of our results is provided.

Results

Twenty‐seven children were enrolled from 2000 to 2009. In this cohort, two patients died because of significant liver disease: one after having two liver and bowel transplants. Overall, survival stands at 92%. All had autologous gastrointestinal reconstruction, and 19 patients underwent bowel lengthening (longitudinal intestinal lengthening and tailoring). The median residual length of bowel of this subgroup at first operation was 25 cm in those who had their gut measured. Two patients were lost to follow‐up. Two patients remain on supplemental total parenteral nutrition (TPN), with an overall 91% of surviving patients off TPN at a median of 6 months after reconstruction.

Conclusions

We believe this improvement is related to the development—over many years—of a structured pathway for managing these patients.
Predictors of the Development of Surgical Complications among Hematopoietic Stem Cell Transplantation Recipients
Authors: Anabtawi Iyad , Abdelrahman Fawzi , Alomari Ahamd , Ba’ba’ Murad , Al Masri Mahmoud
Published: February 2012

Background

This study was designed to determine possible risk factors for the development of surgical complications after hematopoietic stem cell transplantation (HSCT). HSCT carries the possibility for the development of surgical morbidities and mortalities; certain populations of patients are at higher risk for developing complications. Defining those risk factors will help surgeons to anticipate and manage these complications.

Methods

The records of 165 patients at King Hussein Cancer Center (KHCC) were reviewed from January 2007 to December 2008. Patients’ characteristics, including age, source and type of transplant, behavior of disease, total body irradiation (TBI), immunity status, and intensity of conditioning were studied.

Results

According to our data, abdominal complications were more common among patients who received TBI versus patients who did not, and in patients who received peripheral blood versus bone marrow and cord blood as the source of stem cells. Ear, nose, and throat (ENT) complications were found more in patients who underwent nonmyeloablation conditioning. Catheter‐related complications were found more significantly in immune‐compromised patients during the post‐engraftment period. We also found that ENT complications were more frequent in patients with cord blood as the source of stem cells, although the results are inconclusive due to the small sample size.

Conclusions

Pretransplantation factors can be used as predictors for the development of surgical complications in HSCT recipients. Abdominal complications were significantly more common in patients who received total body irradiation as part of their conditioning regimen and when the peripheral blood was a source for stem cell transplantation.
Hepatic S4a + S5 and bile duct resection for gallbladder carcinoma
Authors: Miyazaki Masaru , Shimizu Hiroaki , Ohtsuka Masayuki , Yoshidome Hiroyuki , Kato Atsushi , Yoshitomi Hideyuki , Furukawa Katsunori , Kimura Fumio
Published: February 2012

In the surgical treatment of gallbladder cancer, segment 4a + 5 hepatic resection and bile duct resection is usually recommended for T2 and/or T3 gallbladder cancer involving hepatic parenchyma without hepatic biliary confluence. This procedure does not affect liver function excessively, provided there is correct identification of hepatic S4a and S5, the most important aspect of this procedure. In this paper, the technique of hepatic S4a + 5 and bile duct resection is described in detail. This surgical procedure could be a useful option for the surgical treatment of the hepatobiliary pancreatic malignancies. Surgeons should therefore master the surgical techniques for this procedure.
Non-photorealistic neural sketching
Authors: de Arruda Francisco de Assis Pereira Vasconce , de Queiroz José Eustáquio Rangel , Gomes Herman Martins
Published: February 2012

We present and evaluate a neural network-based technique to automatically enable NPR renderings from digital face images, which resemble semi-detailed sketches. The technique has been experimentally evaluated and compared with traditional approaches to edge detection (Canny and Difference of Gaussians, or DoG) and with a more recent variant, specifically designed for stylization purposes (Flow Difference of Gaussians, or FDoG). An objective evaluation showed, after an ANOVA analysis and a Tukey t-test, that the proposed approach was equivalent to the FDoG technique and superior to the DoG. A subjective experiment involving the opinion of human observers proved to be complementary to the objective analysis.
Safe Injection Practices for Administration of Propofol
Authors: King Cecil A. , Ogg Mary
Published: February 2012

Sepsis and postoperative infection can occur as a result of unsafe practices in the administration of propofol and other injectable medications. Investigations of infection outbreaks have revealed the causes to be related to bacterial growth in or contamination of propofol and unsafe medication practices, including reuse of syringes on multiple patients, use of single‐use medication vials for multiple patients, and failure to practice aseptic technique and adhere to infection control practices. Surveys conducted by AORN and other researchers have provided additional information on perioperative practices related to injectable medications. In 2009, the US Food and Drug Administration and the Centers for Disease Control and Prevention convened a group of clinicians to gain a better understanding of the issues related to infection outbreaks and injectable medications. The meeting participants proposed collecting data to persuade clinicians to adopt new practices, developing guiding principles for propofol use, and describing propofol‐specific, site‐specific, and practitioner‐specific injection techniques. AORN provides resources to help perioperative nurses reduce the incidence of postoperative infection related to medication administration.
Clinical Issues—March 2012
Authors: Denholm Bonnie
Published: February 2012

This Month

Using multidose vials

Key words: multidose vials, cross contamination, single‐dose vials, safe injection practices.

Perioperative incremental local anesthetic injections

Key words: multiple injections, safe injection practices, incremental doses, local anesthetics.

Placing unsterile solutions on the sterile field

Key words: safe medication practices, unsterile solutions, nonmedications, chemical solutions.

Sterilizing or disinfecting ureteroscopes and colonoscopes

Key words: flexible scopes, cystoscopy, ureteroscopy, colon reanastomosis, high‐level disinfection.
Implementing Evidence‐Based Practice: Real‐Life Success Stories
Authors: Cote Deborah
Published: February 2012

Implementing Evidence‐Based Practice: Real‐Life Success Stories Bernadette Mazurek Melnyk, Ellen Fineout‐Overholt 2011, Sigma Theta Tau International 352 pages, softcover
Implementing AORN Recommended Practices for Electrosurgery
Authors: Spruce Lisa , Braswell Melanie L.
Published: February 2012

Technology is constantly changing, and it is important for perioperative nurses to stay current on new products and technologies in the perioperative setting. AORN's “Recommended practices for electrosurgery” addresses safety standards that all perioperative personnel should follow to minimize risks to both patients and staff members during the use of electrosurgical devices. Recommendations include how to select electrosurgical units and accessories for purchase, how to minimize the potential for patient and staff member injuries, what precautions to take during minimally invasive surgery, and how to avoid surgical smoke hazards. The recommendations also address education/competency, documentation, policies and procedures, and quality assurance/performance improvement. Perioperative nurses should consider the use of checklists and safety posters to remind staff members of the dangers of electrosurgery and the steps to take to minimize the risks for injury.
Inhibitory effects of choline‐O‐sulfate on amyloid formation of human islet amyloid polypeptide
Authors: Hagihara Mamoru , Takei Ayaka , Ishii Takeshi , Hayashi Fumio , Kubota Kenji , Wakamatsu Kaori , Nameki Nobukazu
Published: February 2012

Choline‐O‐sulfate (2‐(trimethylammonio)ethyl sulfate, COS) is a naturally occurring osmolyte that is synthesized by plants, lichens, algae, fungi, and several bacterial species. We examined the inhibitory effects of COS on amyloid formation of the human islet amyloid polypeptide (hIAPP or amylin) using a thioflavin T (ThT) fluorescence assay, circular dichroism spectroscopy and transmission electron microscopy. The results showed that COS suppresses a conformational change of hIAPP from a random coil to a β‐sheet structure, resulting in the inhibition of amyloid formation. Comparisons with various structural analogs including carnitine, acetylcholine and non‐detergent sulfobetaines (NDSBs) using the ThT fluorescence assay showed that COS is the most effective inhibitor of hIAPP amyloid formation, suggesting that the sulfate group, which is unique to COS, significantly contributes to the inhibition.
Elliptic and hyperbolic interior solutions of piecewise-constant potential vorticity geophysical vortices
Authors: Viúdez Álvaro
Published: February 2012

Elliptic and hyperbolic geopotential solutions, for a homogeneous distribution of potential vorticity (PV), are obtained via PV inversion in geophysical vortices. The flow in the axisymmetrical three-dimensional vortices is steady and horizontal, where the centripetal acceleration plus the Coriolis acceleration equals the pressure anomaly gradient term (gradient wind or cyclo-geostrophic balance). It is found that the family of geopotential solutions in the vortex interior is completely parameterized by the PV density in the vortex and the squared aspect ratio between the horizontal and vertical semi-axes of the ellipsoidal or hyperbolic geopotential surfaces. Thus, the PV inversion task consists of obtaining, via solution of algebraic cubic equations, the absolute vertical vorticity and vertical stratification as a function of PV and aspect ratio. It is found that there is always a critical aspect ratio, which depends on PV, beyond which the PV inversion solutions are multi-valued. The complete vorticity and stratification solutions for the different regions in the PV and aspect ratio space are obtained and analysed with emphasis on the inertial and static instability of the vortex flow.
MAXIMUM SIZE OF SUBSETS OF PAIRWISE NONCOMMUTING ELEMENTS IN FINITE METACYCLIC p-GROUPS
Authors: FOULADI S. , ORFI R.
Published: February 2012

Let G be a finite group. A subset X of G is a set of pairwise noncommuting elements if any two distinct elements of X do not commute. In this paper we determine the maximum size of these subsets in any finite nonabelian metacyclic p-group for an odd prime p.
Dietary fatty acid intake, its food sources and determinants in European adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study
Authors: Vyncke Krishna E. , Libuda Lars , De Vriendt Tineke , Moreno Luis A. , Van Winckel Myriam , Manios Yannis , Gottrand Frederic , Molnar Denes , Vanaelst Barbara , Sjöström Michael , González-Gross Marcela , Censi Laura , Widhalm Kurt , Michels Nathalie , Gilbert Chantal C. , Xatzis Christos , Cuenca García Magdalena , de Heredia Fátima Pérez , De Henauw Stefaan , Huybrechts Inge ,   on behalf of the HELENA consortium
Published: February 2012

Dietary fatty acids (FA) play a role in several (patho)physiological processes at any age, and different FA have different effects on lipid status and health outcome. The present study aims to describe the FA intake and its main food sources in a population of healthy European adolescents and to assess the variation in intake as a function of non-dietary factors. FA intake was assessed with 24 h recall interviews in 1804 adolescents aged 12·5–17·5 years. Usual intakes were calculated using the multiple source method. Multilevel analyses, adjusting for study centre, were used to investigate the influence of non-dietary factors. The mean total fat intake was 33·3 (sd1·2) % of total energy intake (%E). The mean SFA intake was 13·8 (sd1·2) %E, with 99·8 % of the population exceeding the recommendations. SFA was mainly delivered by meat and cake, pies and biscuits. In most adolescents, the PUFA intake was too low, and 35·5 % of the population did not achieve the minimum recommended intake for α-linolenic acid (ALA). The main determinants of FA intake in the present study population were age and sex, as well as physical activity in the male subgroup. No contributions of body composition, socio-economic status or sexual maturation to the variance in FA intake were observed. In conclusion, the most important public health concerns regarding FA intake in this adolescent population were the low intake of ALA and the high intake of SFA, mainly seen in the younger-aged boys. In this group the major contributor to SFA was meat.