bluuebunny/crossref_metadata_2025 huggingface dataset:
Electro-physical characterization of individual and arrays of ZnO nanowires
Authors: Mallampati Bhargav , Singh Abhay , Shik Alex , Ruda Harry E. , Philipose U.
Published: July 2015

Capacitance measurements were made on an array of parallel ZnO nanowires embedded in a polymer matrix and provided with two electrodes perpendicular to the nanowires. The capacitance monotonically increased, and saturated at large negative (depleting) and large positive (accumulating) voltages. A qualitative explanation for this behavior is presented, taking into account specific features of quasi-one-dimensional screening. The increasing or decreasing character of the capacitance-voltage characteristics were determined by the conductivity type of the nanowires, which in our case was n-type. A dispersion of the experimental capacitance was observed over the entire frequency range of 1 kHz to 5 MHz. This phenomenon is explained by the slow discharge of the nanowires through the thin dielectric layer that separates them from the top electrode. Separate measurements on individual identical nanowires in a field effect transistor configuration yielded an electron concentration and mobility of approximately 1017 cm−3 and 150 cm2/Vs, respectively, at room temperature.
Improving grid connected hybrid generation system supervision with sensorless control
Authors: Boukettaya Ghada , Naifar Omar
Published: July 2015

In this paper, speed identification and control problems are simultaneously considered for a micro-grid power generation system (MG-PGS). To eliminate mechanical sensors, an observer has been designed to identify the speed of a wind energy conversion system based on a permanent magnet synchronous machine (PMSM). The proposed observer is an adaptive interconnected structure with online parametric estimation. Moreover, a new control based on the Lyapunov theory has been developed in order to improve sensorless control of a flywheel energy storage system based on induction machine. In fact, the main idea of this control technique is based on an appropriate choice of voltage control values that guaranty the global stability of the controlled system. Simulation results indicate that the sensorless control applied to the MG-PGS improves performances of the global control. The PMSM mechanical speed, the stator resistance, and inductance could be estimated precisely, and the dynamical property of the system is obviously improved.
Numerical experiment to estimate the validity of negative ion diagnostic using photo-detachment combined with Langmuir probing
Authors: Oudini N. , Sirse N. , Benallal R. , Taccogna F. , Aanesland A. , Bendib A. , Ellingboe A. R.
Published: July 2015

This paper presents a critical assessment of the theory of photo-detachment diagnostic method used to probe the negative ion density and electronegativity α = n-/ne. In this method, a laser pulse is used to photo-detach all negative ions located within the electropositive channel (laser spot region). The negative ion density is estimated based on the assumption that the increase of the current collected by an electrostatic probe biased positively to the plasma is a result of only the creation of photo-detached electrons. In parallel, the background electron density and temperature are considered as constants during this diagnostics. While the numerical experiments performed here show that the background electron density and temperature increase due to the formation of an electrostatic potential barrier around the electropositive channel. The time scale of potential barrier rise is about 2 ns, which is comparable to the time required to completely photo-detach the negative ions in the electropositive channel (∼3 ns). We find that neglecting the effect of the potential barrier on the background plasma leads to an erroneous determination of the negative ion density. Moreover, the background electron velocity distribution function within the electropositive channel is not Maxwellian. This is due to the acceleration of these electrons through the electrostatic potential barrier. In this work, the validity of the photo-detachment diagnostic assumptions is questioned and our results illustrate the weakness of these assumptions.
Identifying site-dependent effects of an extra Co atom on electronic states of single Co-phthalocyanine molecule
Authors: Li Jingcheng , Li Bin , Wang Yu , Zhao Aidi , Wang Bing
Published: July 2015

We investigate the modification of electronic properties of single cobalt phthalocyanine (CoPc) molecule by an extra Co atom co-adsorbed on Au (111) surface using scanning tunneling microscopy (STM), joint with density functional theory (DFT) calculations. By manipulating CoPc molecules using the STM tip to contact individually adsorbed Co atom, two types of relatively stable complexes can be formed, denoted as CoPc-Co(i) and CoPc-Co(ii). In CoPc-Co(i), the Co atom is at an intramolecular site close to aza-N atom of CoPc, which induces significant modifications of the electronic states of CoPc, such as energy shifts and splitting of nonlocal molecular orbitals. However, in CoPc-Co(ii) where the Co atom is underneath a benzene lobe of CoPc, it only slightly modifies the electronic states of CoPc, and mainly local characteristics of specific molecular orbitals are affected, even though CoPc-Co(ii) is more stable than CoPc-Co(i). Our DFT calculations give consistent results with the experiments, and related analyses based on the molecular orbital theory reveal mechanism behind the experimental observations.
Origin of the visible emission of black silicon microstructures
Authors: Fabbri Filippo , Lin Yu-Ting , Bertoni Giovanni , Rossi Francesca , Smith Matthew J. , Gradečak Silvija , Mazur Eric , Salviati Giancarlo
Published: July 2015

Silicon, the mainstay semiconductor in microelectronics, is considered unsuitable for optoelectronic applications due to its indirect electronic band gap that limits its efficiency as light emitter. Here, we univocally determine at the nanoscale the origin of visible emission in microstructured black silicon by cathodoluminescence spectroscopy and imaging. We demonstrate the formation of amorphous silicon oxide microstructures with a white emission. The white emission is composed by four features peaking at 1.98 eV, 2.24 eV, 2.77 eV, and 3.05 eV. The origin of such emissions is related to SiOx intrinsic point defects and to the sulfur doping due to the laser processing. Similar results go in the direction of developing optoelectronic devices suitable for silicon-based circuitry.
Quasi-conformal transformation optics with elasto-electromagnetic metamaterials: Design algorithm
Authors: Shin Dongheok , Kim Junhyun , Seo Ilsung , Kim Kyoungsik
Published: July 2015

We report here a design method that is used to determine the initial shapes of elasto-electromagnetic metamaterial blocks with respect to the given shape of a hiding object when these blocks are applied to the problem of carpet cloaking. Starting from the inhomogeneous permittivity distribution of a cloak, derived using transformation optics, we use an inverse process to design the initial shape of a uniform permittivity material for an arbitrary value of Poisson's ratio in the range from −1 to 0.5. Then, by elastic compression of the initially uniform metamaterial, we obtain the inhomogeneous permittivity distribution that is required for cloaking. Our design method is then experimentally verified by measurements of the electric field profiles in smart metamaterial cloaks.
Characterization and reactivity of the weakly bound complexes of the [H, N, S]− anionic system with astrophysical and biological implications
Authors: Trabelsi T. , Ajili Y. , Ben Yaghlane S. , Jaidane N.-E. , Mogren Al-Mogren M. , Francisco J. S. , Hochlaf M.
Published: July 2015

We investigate the lowest electronic states of doublet and quartet spin multiplicity states of HNS− and HSN− together with their parent neutral triatomic molecules. Computations were performed using highly accurate ab initio methods with a large basis set. One-dimensional cuts of the full-dimensional potential energy surfaces (PESs) along the interatomic distances and bending angle are presented for each isomer. Results show that the ground anionic states are stable with respect to the electron detachment process and that the long range parts of the PESs correlating to the SH− + N, SN− + H, SN + H−, NH + S−, and NH− + S are bound. In addition, we predict the existence of long-lived weakly bound anionic complexes that can be formed after cold collisions between SN− and H or SH− and N. The implications for the reactivity of these species are discussed; specifically, it is shown that the reactions involving SH−, SN−, and NH− lead either to the formation of HNS− or HSN− in their electronic ground states or to autodetachment processes. Thus, providing an explanation for why the anions, SH−, SN−, and NH−, have limiting detectability in astrophysical media despite the observation of their corresponding neutral species. In a biological context, we suggest that HSN− and HNS− should be incorporated into H2S-assisted heme-catalyzed reduction mechanism of nitrites in vivo.
Karpman-Washimi magnetization with electron-exchange effects in quantum plasmas
Authors: Hong Woo-Pyo , Jamil M. , Rasheed A. , Jung Young-Dae
Published: July 2015

The influence of quantum electron-exchange on the Karpman-Washimi ponderomotive magnetization is investigated in quantum plasmas. The ponderomotive magnetization and the total radiation power due to the non-stationary Karpman-Washimi interaction related to the time-varying field intensity are obtained as functions of the de Broglie wave length, Debye length, and electron-exchange parameter. The result shows that the electron-exchange effect enhances the cyclotron frequency due to the ponderomotive interactions in quantum plasmas. It is also shown that the electron-exchange effect on the Karpman-Washimi magnetization increases with increasing wave number. In addition, the Karpman-Washimi magnetization and the total radiation power increase with an increase in the ratio of the Debye length to the de Broglie wave length. In streaming quantum plasmas, it is shown that the electron-exchange effect enhances the ponderomotive magnetization below the resonant wave number and, however, suppresses the ponderomotive magnetization above the resonant wave number. The variation of the Karpman-Washimi magnetization and the radiation power due to the variation of the electron-exchange effect and plasma parameters is also discussed.
A Mechanism Study of a Novel Acid-Activatable Michael-Type Fluorescent Probe for Thiols
Authors: Tong Yao , Dai Chun-guang , Ren Yi , Luo Shi-wei
Published: July 2015

A Michael addition is usually taken as a base-catalysed reaction. However, our synthesized 2-(quinolin-2-ylmethylene) malonic acid (QMA) as a Michael-type thiol fluorescent probe is acid-active in its sensing reaction. In this work, based on theoretic calculation and experimental study on 7-hydroxy-2-(quinolin-2-ylmethylene) malonic acid, we demonstrated that QMA as a Michael acceptor is acid-activatable, i.e., it works only in solutions at pH<7, and the lower the pH of solutions is, the higher reactivity QMA has. In alkaline solution, the malonate QMA[-2H+]2− cannot react with both RS− and RSH. In contrast, 2-(quinolin-2-ylmethylene) malonic ester (QME), the ester of QMA, reveal a contrary pH effect on its sensing reaction, that is, it can sense thiols in alkaline solutions but not in acidic solutions, like a normal base-catalysed Michael addition. The values of activation enthalpies from theoretic calculation support the above sensing behavior of two probes under different pH conditions. In acidic solutions, the protonated QMA is more highly reactive towards electrophilic attack over its other ionized states in neutral and alkaline solutions, and so can react with lowly reactive RSH. In contrast, there is a big energy barrier in the interaction of QME with RSH (acidic solutions), and the reaction of QME with the highly reactive nucleophile RS− is a low activation energy process (in alkaline solutions). Theoretic calculation reveals that the sensing reaction of QMA undergoes a 1,4-addition process with neutral thiols (RSH), and a 1,2-addition pathway for the sensing reaction of QME with RS−. Therefore, the sensing reaction of QMA is an acid-catalysed Michael addition via a 1,4-addition, and a normal base-catalysed Michael addition via a 1,2-addition.
Influence of Water Vapor on Silica Membrane: Adsorption Properties and Percolation Effect
Authors: Song Chun-lin , Liu Gang
Published: July 2015

The influence of water vapor on silica membrane with pore size of ∼4 Å has been investigated in terms of adsorption properties and percolation effect at 50 and 90 °C. Two methods are employed: spectroscopic ellipsometry for water vapor adsorption and gas permeation of binary mixture of helium and H2O. The adsorption behaviors on the silica membrane comply with the first-order Langmuir isotherm. The investigation demonstrates that helium flux through the silica membrane decreases dramatically in presence of H2O molecules. The transport of gas molecules through such small pores is believed not to be continuous any more, whereas it is reasonably assumed that the gas molecules hop from one occupied site to another unoccupied one under the potential gradient. When the coverage of H2O molecules on the silica surface increases, the dramatic decrease of helium flux could be related to percolation effect, where the adsorbed H2O molecules on the silica surface block the hopping of helium molecules.
Phase Equilibria of Hydrogen Bonding Fluid in a Slit Pore with Broken Symmetry
Authors: Liu Xiao-yu , Li Jiang-tao , Gu Fang , Wang Hai-jun
Published: July 2015

Phase equilibria of hydrogen bonding (HB) fluid confined in a slit pore with broken symmetry were investigated by the density functional theory incorporated with modified fundamental measure theory, where the symmetry breaking originated from the distinct interactions between fluid molecules and two walls of the slit pore. In terms of adsorption-desorption isotherms and the corresponding grand potentials, phase diagrams of HB fluid under various conditions are presented. Furthermore, through phase coexistences of laying transition and capillary condensation, the effects of HB interaction, pore width, fluid-pore interaction and the broken symmetry on the phase equilibrium properties are addressed. It is shown that these factors can give rise to apparent influences on the phase equilibria of confined HB fluid because of the competition between intermolecular interaction and fluid-pore interaction. Interestingly, a significant influence of broken symmetry of the slit pore is found, and thus the symmetry breaking can provide a new way to regulate the phase behavior of various confined fluids.
Investigation of Roughness Periodicity on the Hydrophobic Properties of Surfaces
Authors: Toster Jeremiah , Lewis David
Published: July 2015

Hydrophobic films were synthesized with a variety of silica particle sizes ranging from 58 to 1428 nm to investigate the effect of particle size on the contact and sliding angles. While the surface roughness created by varying the particle size did not appear to affect water contact angles, the sliding angles showed a significant monotonic decrease, reducing from 90° to 20°.
Generation of sequence-based data for pedigree-segregating Mendelian or Complex traits
Authors: Li Biao , Wang Gao T. , Leal Suzanne M.
Published: July 2015

Motivation: There is great interest in analyzing next generation sequence data that has been generated for pedigrees. However, unlike for population-based data there are only a limited number of rare variant methods to analyze pedigree data. One limitation is the ability to evaluate type I and II errors for family-based methods, due to lack of software that can simulate realistic sequence data for pedigrees.

Summary: We developed RarePedSim (Rare-variant Pedigree-based Simulator), a program to simulate region/gene-level genotype and phenotype data for complex and Mendelian traits for any given pedigree structure. Using a genetic model, sequence variant data can be generated either conditionally or unconditionally on pedigree members’ qualitative or quantitative phenotypes. Additionally, qualitative or quantitative traits can be generated conditional on variant data. Sequence data can either be simulated using realistic population demographic models or obtained from sequence-based studies. Variant sites can be annotated with positions, allele frequencies and functionality. For rare variants, RarePedSim is the only program that can efficiently generate both genotypes and phenotypes, regardless of pedigree structure. Data generated by RarePedSim are in standard Linkage file (.ped) and Variant Call (.vcf) formats, ready to be used for a variety of purposes, including evaluation of type I error and power, for association methods including mixed models and linkage analysis methods.

Availability and Implementation:  bioinformatics.org/simped/rare

Contact:  sleal@bcm.edu
Pretreatment Assessment
Authors: Ladouceur Robert , Lachance Stella
Published: July 2015

Chapter 2 outlines the pretreatment assessment that will be undertaken before the treatment program starts. Assessments include the Diagnostic Interview for Pathological Gambling (DPIG), a self-efficacy questionnaire, and questions to help the therapist determine whether the client meets the criteria for pathological gambling.
Follow-Up Assessment
Authors: Ladouceur Robert , Lachance Stella
Published: July 2015

Chapter 10 presents a plan for follow-up sessions that should be held with the client in the months following the conclusion of the treatment program. These sessions will include assessments to measure progress that was made during treatment, and to ensure that progress is still being made.
Association of Intraoperative Hypotension with Acute Kidney Injury after Elective Noncardiac Surgery
Authors: Sun Louise Y. , Wijeysundera Duminda N. , Tait Gordon A. , Beattie W. Scott
Published: July 2015

AbstractAbstract

In a retrospective study of 5,127 patients undergoing noncardiac surgery, an increased risk of postoperative acute kidney injury (defined as >50% or 0.3 mg/dl increase in serum creatinine concentration) was found when intraoperative mean arterial pressure was less than 60 mmHg for more than 20 min and less than 55 mmHg for more than 10 min.

Supplemental Digital Content is available in the text.

Background:

Intraoperative hypotension (IOH) may be associated with postoperative acute kidney injury (AKI), but the duration of hypotension for triggering harm is unclear. The authors investigated the association between varying periods of IOH with mean arterial pressure (MAP) less than 55, less than 60, and less than 65 mmHg with AKI.

Methods:

The authors conducted a retrospective cohort study of 5,127 patients undergoing noncardiac surgery (2009 to 2012) with invasive MAP monitoring and length of stay of 1 or more days. Exclusion criteria were preoperative MAP less than 65 mmHg, dialysis dependence, urologic surgery, and surgical duration less than 30 min. The primary exposure was IOH. The primary outcome was AKI (50% or 0.3 mg/dl increase in creatinine) during the first 2 postoperative days. Multivariable logistic regression was used to model the exposure–outcome relationship.

Results:

AKI occurred in 324 (6.3%) patients and was associated with MAP less than 60 mmHg for 11 to 20 min and MAP less than 55 mmHg for more than 10 min in a graded fashion. The adjusted odds ratio of AKI for MAP less than 55 mmHg was 2.34 (1.35 to 4.05) for 11- to 20-min exposure and 3.53 (1.51 to 8.25) for more than 20 min. For MAP less than 60 mmHg, the adjusted odds ratio for AKI was 1.84 (1.11 to 3.06) for 11- to 20-min exposure.

Conclusions:

In this analysis, postoperative AKI is associated with sustained intraoperative periods of MAP less than 55 and less than 60 mmHg. This study provides an impetus for clinical trials to determine whether interventions that promptly treat IOH and are tailored to individual patient physiology could help reduce the risk of AKI.
Propensity Score Adjusted Comparison of MIDCAB versus Full Sternotomy Left Anterior Descending Artery Revascularization
Authors: Raja Shahzad G. , Benedetto Umberto , Alkizwini Eman , Gupta Sapna , Amrani Mohamed
Published: July 2015

Objective

Minimally invasive direct coronary artery bypass (MIDCAB) has been proposed as an attractive alternative to full sternotomy (FS) revascularization in isolated left anterior descending (LAD) artery disease not suitable for percutaneous coronary intervention. However, surgeons are still reluctant to perform MIDCAB owing to concerns about early and late outcomes. We aimed to compare short- and long-term outcomes after MIDCAB versus FS revascularization.

Methods

Prospectively collected data from institutional database were reviewed. Data for late mortality were obtained from the General Register Office. MIDCAB was performed in 318 patients, whereas 159 had FS, according to the surgeon's preference, among 477 patients with isolated LAD disease. Inverse propensity score weighting was used to estimate treatment effects on short- and long-term outcomes.

Results

In the propensity score-adjusted analysis, FS revascularization versus MIDCAB was associated increased rate of surgical site infection [4 (2.8%) versus 1 (0.7%); P = 0.04]. The 2 groups did not significantly differ with regard to other complications including operative mortality. Mean length of hospital stay was similar for the 2 groups. After a mean follow-up time of 6.2 years (interquartile range, 3.5–9.7 years), compared to MIDCAB, FS was not associated with an improved late survival (β coef, −1.42; standard error, 1.65; P = 0.39) or risk reduction for repeat revascularization (β coef, 1.22; standard error, 1.41; P = 0.15).

Conclusions

MIDCAB was associated with a trend toward better short-term outcomes and excellent long-term results comparable to FS revascularization. According to these findings, surgeons should not be reluctant to perform MIDCAB in isolated LAD disease.
In Vitro Hemocompatibility Testing of Dyneema Purity Fibers in Blood Contact
Authors: Basir Amir , de Groot Philip , Gründeman Paul F. , Tersteeg Claudia , Maas Coen , Barendrecht Arjan , Van Herwaarden Joost , Kluin Jolanda , Moll Frans , Pasterkamp Gerard , Roest Mark
Published: July 2015

Objective

Heart valve and vascular prosthesis implantation is a common procedure for patients with heart valve stenosis or regurgitation and dilated or obstructive vascular disease. Drawbacks of conventional valve prostheses are the requirement for anticoagulant drugs, moderate durability, and suboptimal resistance to fatigue and tear. Dyneema Purity fibers are made from ultra-high-molecular-weight polyethylene filaments and are very thin, flexible, and fatigue and abrasion resistant and have high strength. Therefore, prostheses made from Dyneema Purity fibers might be attractive for use in the minimally invasive treatment of valvular- and vascular diseases. The aim of this study was to test the hemocompatibility of Dyneema Purity fibers in contact with blood.

Methods

Real-time platelet adhesion in human blood of 3 volunteers was quantified after 5 minutes of perfusion on single filaments (Ø 15 μm) of Dyneema Purity and polyester fibers. Plasma thrombin generation was measured by fluoroscopy for patches of Dyneema Purity fibers and for 5 commonly used polyester and expanded polytetrafluoroethylene cardiovascular prostheses.

Results

Platelet adhesion per 1 mm was 6 ± 1.4 on Dyneema Purity filaments and 15 ± 3.4 on polyester filaments ( P = 0.02). Total formed thrombin and the time to peak of its maximum were noninferior for patches of Dyneema Purity fibers compared with the reference materials.

Conclusions

Dyneema Purity fibers are noninferior in adhesion and coagulation activation compared with commonly used cardiovascular prostheses.
Thoracoscopic Occlusion of the Left Atrial Appendage
Authors: Mokracek Ales , Kurfirst Vojtech , Bulava Alan , Hanis Jiri , Tesarik Richard , Pesl Ladislav
Published: July 2015

Objective

Left atrial appendage (LAA) plays a crucial role in the etiopathogenesis and the prevention of the stroke in patients with nonvalvular atrial fibrillation (AF). This paper presents our first experience with thoracoscopic LAA occlusion using an external clip.

Methods

We performed a total of 30 LAA occlusions with the AtriClip from left thoracoscopy approach during the period from July 2012 to July 2013. AtriClip was implanted during the bilateral thoracoscopic radiofrequency (RF) as part of left atrial ablation procedure.

Results

Among the 30 procedures, AtriClip was once periprocedurally partially positioned. In the remaining procedures, the implantation was successful without complications. Of the 30 patients, 29 underwent transesophageal echocardiography and computer tomography examination at 3 months after the procedure. Apart from the patient with the partial clip placement, a residual pouch of 18 mm was detected in another patient. In the remaining group (28/30 patients, 93%), the exclusion was complete. No migration or any other clip implantation-related complications occurred during the follow-up. None of the patients experienced an embolization event.

Conclusions

Endoscopic AtriClip implantation appears to be a reproducible and safe method of LAA occlusion, with a minimal risk and a high efficiency. In our opinion, the AtriClip implantation is a reasonable part of thoracoscopic AF treatment and should be considered as an alternative tool for stroke risk reduction in patients with AF.
p40 in Conjunction With CK20 and E-Cadherin Distinguishes Primary Adnexal Neoplasms of the Skin
Authors: Andruszkow Julia H. K. , Oll Matthias , Förster Sarah , Knüchel Ruth , Jäkel Jörg
Published: July 2015

Although basal cell carcinomas (BCC) show typical histomorphologic features, they sometimes remain difficult in distinction from benign adnexal skin tumors of follicular origin like trichoepithelioma (TE) or trichoblastoma (TB). Consequently, an immunohistochemical marker panel separating described entities would be helpful in clinical routine. Thus, we stained 22 skin lesions (BCC, TE, and TB) against β-catenin, CK20, E-cadherin, p40, and p63. The staining pattern was described and quantified using an immunohistochemical score. Although p40 and p63 revealed a strong staining intensity of all skin lesions without distinction between BCC and benign lesions (P=1.000), established Merkel cell marker CK20 illustrated a loss of staining in BCC compared with TE and TB (P=0.007). In contrast, BCC exhibited an increased expression of E-cadherin in relation to TE and TB (P=0.009). Single application of CK20 or E-cadherin could predict diagnosis of BCC in 81.8% or 72.7%, respectively. Combining consecutive staining of E-cadherin and CK20 could even enhance specificity toward diagnosis of TE or TB. Hence, findings of our study imply that sequential staining of CK20 and E-cadherin prevents false-positive classification of BCC. Furthermore, our study demonstrated that p40 exhibits the same staining pattern in BCC, TE, and TB. Therefore, p40 might replace p63 equivalently establishing diagnosis of primary adnexal neoplasms of the skin in the form of BCC as well as benign adnexal tumors. As a result, the depicted immunohistochemical marker panel may be applied for adnexal skin neoplasms as a diagnostic adjunct especially in surgically challenging body regions.
The Surgical Treatment of Toxic Megacolon in Hirschsprung Disease
Authors: Khasanov Rasul , Schaible Thomas , Wessel Lucas M. , Hagl Cornelia Irene
Published: July 2015

Objectives

Enterocolitis remains the most significant cause of morbidity and mortality in Hirschsprung disease (HD). It could progress into toxic megacolon (TM)—acute dilatation of the colon as accompanying toxic complication of Hirschsprung enterocolitis. It is a devastating complication, especially in infants with so far undiagnosed HD.

Methods

A retrospective analysis of medical records of 4 infants with TM was performed. The diagnosis TM was determined on the basis of clinical information (abdominal pain or tenderness, abdominal distension, diarrhea, bloody diarrhea, and constipation), plain x-rays of the abdomen (segmental or total colonic dilation), and the presence of such criteria (fever, high heart rate, increased white blood cell count, C reactive protein, anemia, dehydration, electrolyte disturbances, hypotension). Surgical management and outcome was evaluated by retrospective chart review.

Results

The median duration of symptoms characteristic for TM was 3 days. Toxic megacolon was seen as the first manifestation of previously unknown HD in 3 patients; in 1 newborn, the contrast radiograph was suggestive of HD. In all patients, conservative treatment was failed. Three patients were treated with surgical decompression and ileostomy only. In all these cases, severe complications occurred, consequently 2 of them died. In 1 patient, a resection of the transverse dilated colon additionally was performed. This patient had no complications in postoperative period and survived.

Conclusions

Because of the high mortality in patients with TM that were treated medically or with colonic decompression, a resection of massively distended part of the colon should be performed.
Notification that new names of prokaryotes, new combinations, and new taxonomic opinions have appeared in volume 65, part 3, of the IJSEM
Authors: Oren Aharon , Garrity George M.
Published: July 2015

This listing of names of prokaryotes published in a previous issue of the IJSEM is provided as a service to bacteriology to assist in the recognition of new names and new combinations. This procedure was proposed by the Judicial Commission [Minute 11(ii), Int J Syst Bacteriol 41 (1991), p. 185]. The names given herein are listed according to the Rules of priority (i.e. page number and order of valid publication of names in the original articles).
Inference of super-exponential human population growth via efficient computation of the site frequency spectrum for generalized models
Authors: Gao Feng , Keinan Alon
Published: July 2015

The site frequency spectrum (SFS) and other genetic summary statistics are at the heart of many population genetics studies. Previous studies have shown that human populations had undergone a recent epoch of fast growth in effective population size. These studies assumed that growth is exponential, and the ensuing models leave unexplained excess amount of extremely rare variants. This suggests that human populations might have experienced a recent growth with speed faster than exponential. Recent studies have introduced a generalized growth model where the growth speed can be faster or slower than exponential. However, only simulation approaches were available for obtaining summary statistics under such models. In this study, we provide expressions to accurately and efficiently evaluate the SFS and other summary statistics under generalized models, which we further implement in a publicly available software. Investigating the power to infer deviation of growth from being exponential, we observed that decent sample sizes facilitate accurate inference, e.g. a sample of 3000 individuals with the amount of data expected from exome sequencing allows observing and accurately estimating growth with speed deviating by 10% or more from that of exponential. Applying our inference framework to data from the NHLBI Exome Sequencing Project, we found that a model with a generalized growth epoch fits the observed SFS significantly better than the equivalent model with exponential growth (p-value = 3.85 × 10−6). The estimated growth speed significantly deviates from exponential (p-value << 10−12), with the best-fit estimate being of growth speed 12% faster than exponential.
Tracking the fear memory engram: discrete populations of neurons within amygdala, hypothalamus, and lateral septum are specifically activated by auditory fear conditioning
Authors: Butler Christopher W. , Wilson Yvette M. , Gunnersen Jenny M. , Murphy Mark
Published: July 2015

Memory formation is thought to occur via enhanced synaptic connectivity between populations of neurons in the brain. However, it has been difficult to localize and identify the neurons that are directly involved in the formation of any specific memory. We have previously used fos-tau-lacZ (FTL) transgenic mice to identify discrete populations of neurons in amygdala and hypothalamus, which were specifically activated by fear conditioning to a context. Here we have examined neuronal activation due to fear conditioning to a more specific auditory cue. Discrete populations of learning-specific neurons were identified in only a small number of locations in the brain, including those previously found to be activated in amygdala and hypothalamus by context fear conditioning. These populations, each containing only a relatively small number of neurons, may be directly involved in fear learning and memory.
Prediction error and trace dominance determine the fate of fear memories after post-training manipulations
Authors: Alfei Joaquín M. , Ferrer Monti Roque I. , Molina Victor A. , Bueno Adrián M. , Urcelay Gonzalo P.
Published: July 2015

Different mnemonic outcomes have been observed when associative memories are reactivated by CS exposure and followed by amnestics. These outcomes include mere retrieval, destabilization–reconsolidation, a transitional period (which is insensitive to amnestics), and extinction learning. However, little is known about the interaction between initial learning conditions and these outcomes during a reinforced or nonreinforced reactivation. Here we systematically combined temporally specific memories with different reactivation parameters to observe whether these four outcomes are determined by the conditions established during training. First, we validated two training regimens with different temporal expectations about US arrival. Then, using Midazolam (MDZ) as an amnestic agent, fear memories in both learning conditions were submitted to retraining either under identical or different parameters to the original training. Destabilization (i.e., susceptibly to MDZ) occurred when reactivation was reinforced, provided the occurrence of a temporal prediction error about US arrival. In subsequent experiments, both treatments were systematically reactivated by nonreinforced context exposure of different lengths, which allowed to explore the interaction between training and reactivation lengths. These results suggest that temporal prediction error and trace dominance determine the extent to which reactivation produces the different outcomes.
Importance of the GluN2B carboxy-terminal domain for enhancement of social memories
Authors: Jacobs Stephanie , Wei Wei , Wang Deheng , Tsien Joe Z.
Published: July 2015

The N-methyl-D-aspartate (NMDA) receptor is known to be necessary for many forms of learning and memory, including social recognition memory. Additionally, the GluN2 subunits are known to modulate multiple forms of memory, with a high GluN2A:GluN2B ratio leading to impairments in long-term memory, while a low GluN2A:GluN2B ratio enhances some forms of long-term memory. Here, we investigate the molecular motif responsible for the differences in social recognition memory and olfactory memory in the forebrain-specific transgenic GluN2A overexpression mice and the forebrain-specific transgenic GluN2B overexpression mice by using two transgenic mouse lines that overexpress chimeric GluN2 subunits. The transgenic chimeric GluN2 subunit mice were tested for their ability to learn and remember fruit scents, male juveniles of the same strain, females of the same strain, male juveniles of another strain, and rodents of another species. The data presented here demonstrate that the GluN2B carboxy-terminal domain is necessary for enhanced social recognition memory in GluN2B transgenic overexpression mice. Furthermore, the GluN2A carboxy-terminal domain is responsible for the impaired long-term olfactory and social memory observed in the GluN2A overexpression mice.
Ultra-stable sub-meV monochromator for hard X-rays
Authors: Toellner T. S. , Collins J. , Goetze K. , Hu M. Y. , Preissner C. , Trakhtenberg E. , Yan L.
Published: July 2015

A high-resolution silicon monochromator suitable for 21.541 keV synchrotron radiation is presented that produces a bandwidth of 0.27 meV. The operating energy corresponds to a nuclear transition in151Eu. The first-of-its-kind, fully cryogenic design achieves an energy-alignment stability of 0.017 meV r.m.s. per day, or a 100-fold improvement over other meV-monochromators, and can tolerate higher X-ray power loads than room-temperature designs of comparable resolution. This offers the potential for significantly more accurate measurements of lattice excitation energies using nuclear resonant vibrational spectroscopy if combined with accurate energy calibration using, for example, high-speed Doppler shifting. The design of the monochromator along with its performance and impact on transmitted beam properties are presented.
Development of dispersive XAFS system for analysis of time-resolved spatial distribution of electrode reaction
Authors: Katayama Misaki , Miyahara Ryota , Watanabe Toshiki , Yamagishi Hirona , Yamashita Shohei , Kizaki Terue , Sugawara Yoshimi , Inada Yasuhiro
Published: July 2015

Apparatus for a technique based on the dispersive optics of X-ray absorption fine structure (XAFS) has been developed at beamline BL-5 of the Synchrotron Radiation Center of Ritsumeikan University. The vertical axis of the cross section of the synchrotron light is used to disperse the X-ray energy using a cylindrical polychromator and the horizontal axis is used for the spatially resolved analysis with a pixel array detector. The vertically dispersive XAFS (VDXAFS) instrument was designed to analyze the dynamic changeover of the inhomogeneous electrode reaction of secondary batteries. The line-shaped X-ray beam is transmitted through the electrode sample, and then the dispersed transmitted X-rays are detected by a two-dimensional detector. An array of XAFS spectra in the linear footprint of the transmitted X-ray on the sample is obtained with the time resolution of the repetition frequency of the detector. Sequential measurements of the space-resolved XAFS data are possible with the VDXAFS instrument. The time and spatial resolutions of the VDXAFS instrument depend on the flux density of the available X-ray beam and the size of the light source, and they were estimated as 1 s and 100 µm, respectively. The electrode reaction of the LiFePO4lithium ion battery was analyzed during the constant current charging process and during the charging process after potential jumping.
Crystal structure of 4-(4-chlorophenyl)-6-(morpholin-4-yl)pyridazin-3(2H)-one
Authors: Aydın Abdullah , Akkurt Mehmet , Şüküroğlu Murat , Büyükgüngör Orhan
Published: July 2015

In the title compound, C14H14ClN3O2, the morpholine ring adopts a chair conformation, with the exocyclic N—C bond in an equatorial orientation. The 1,6-dihydropyridazine ring is essentially planar, with a maximum deviation of 0.014 (1) Å, and forms a dihedral angle of 40.16 (7)° with the plane of the benzene ring. In the crystal, pairs of centrosymmetrically related molecules are linked into dimersviaN—H...O hydrogen bonds, formingR22(8) ring motifs. The dimers are connectedviaC—H...O and C—H...Cl hydrogen bonds, forming a three-dimensional network. Aromatic π–π stacking interactions [centroid–centroid distance = 3.6665 (9) Å] are also observed. Semi-empirical molecular orbital calculations were carried out using the AM1 method. The calculated dihedral angles between the pyridizine and benzene rings and between the pyridizine and morpholine (all atoms) rings are 34.49 and 76.96°, respectively·The corresponding values obtained from the X-ray structure determination are 40.16 (7) and 12.97 (9)°, respectively. The morpholine ring of the title compound in the calculated gas-phase seems to have a quite different orientation compared to that indicated by the X-ray structure determination.
Crystal structure of (ferrocenylmethyl)dimethylammonium hydrogen oxalate
Authors: Ndiaye Mamadou , Samb Abdoulaye , Diop Libasse , Maris Thierry
Published: July 2015

The crystal structure of the title salt, [Fe(C5H5)(C8H13N)](HC2O4), consists of discrete (ferrocenylmethyl)dimethylammonium cations and hydrogen oxalate anions. The anions are connected through a strong O—H...O hydrogen bond, forming linear chains running parallel to [100]. The cations are linked to the anions through bifurcated N—H...(O,O′) hydrogen bonds. Weak C—H...π interactions between neighbouring ferrocenyl moieties are also observed.
Crystal structure of bis[μ-bis(diphenylphosphanyl)methane-κ2P:P′]digold(I) dichloride acetone monosolvate monohydrate
Authors: Yeo Chien Ing , Tan Yee Seng , Tiekink Edward R. T.
Published: July 2015

In the title complex salt, [Au2{(C6H5)2PCH2P(C6H5)2}]Cl2·(CH3)2C=O·H2O, the dication forms an eight-membered {—PCPAu}2ring with a transannular aurophilic interaction [Au...Au = 2.9743 (2) Å]. The ring approximates a flattened boat conformation, with the two methylene C atoms lyingca0.58–0.59 Å above the least-squares plane defined by the Au2P4atoms (r.m.s. deviation = 0.0849 Å). One Cl−anion functions as a weak bridge between the AuIatoms [Au...Cl = 2.9492 (13) and 2.9776 (12) Å]. The second Cl−anion forms two (water)O—H...Cl hydrogen bonds about a centre of inversion, forming a centrosymmetric eight-membered {...HOH...Cl}2supramolecular square. Globally, the dications and loosely associated Cl−anions assemble into layers lying parallel to theacplane, being connected by C—H...Cl,π(phenyl) interactions. The supramolecular squares and solvent acetone molecules are sandwiched in the inter-layer region, being connected to the layers on either side by C—H...Cl,O(acetone) interactions.
Crystal structure of 1-benzyl-2-hydroxy-5-oxopyrrolidin-3-yl acetate
Authors: Caracelli Ignez , Zukerman-Schpector Julio , Stefani Hélio A. , Ali Bakhat , Tiekink Edward R. T.
Published: July 2015

In the title compound, C13H15NO4, the oxopyrrolidin-3-yl ring has an envelope conformation, with the C atom bearing the acetate group being the flap. The acetate and phenyl groups are inclined with respect to the central ring, forming dihedral angles of 50.20 (12) and 87.40 (9)°, respectively, with the least-squares plane through the ring. The dihedral angle between the acetate group and the phenyl ring is 63.22 (8)°, indicating a twisted conformation in the molecule. In the crystal, supramolecular chains along thebaxis are formed by (hydroxy)O—H...O(ring carbonyl) hydrogen bonds. The chains are consolidated into the three-dimensional architecture by C—H...O interactions.
Crystal structure of 1-[(1S,2R)-2-hydroxy-1-methyl-2-phenylethyl]pyrrolidinium 2-amino-5-chlorobenzoate
Authors: Li Yunli , Li Zhanjun , Hu Yanjie , Li Wen
Published: July 2015

In the cation of the title molecular salt, C13H20NO+·C7H5ClNO2−, the five-membered ring adopts a twisted conformation about one of the C—N bonds. The exocyclic N—C bond has an equatorial orientation. The dihedral angle between the five-membered ring (all atoms) and the benzene ring is 76.56 (19)°. In the anion, the dihedral angle between the carboxylate group and the benzene ring is 18.57 (14)°, and an intramolecular N—H...O hydrogen bond closes anS(6) ring. In the crystal, the components are linked by O—H...O and N—H...O hydrogen bonds, generating [100] chains.
Crystal structure of 4-oxo-4H-chromene-3-carboxylic acid
Authors: Ishikawa Yoshinobu
Published: July 2015

In the title compound, C10H6O4, also known as 3-carboxychromone, the non-H atoms of the chromone ring are essentially coplanar (r.m.s. deviation = 0.0057 Å), with the maximum deviation from their least-squares plane [0.011 (2) Å] being for a pyran C atom. The dihedral angle between the fused ring and plane of the carboxy group is 3.06 (2)°. An intramolecular hydrogen bond is formed between the ring carbonyl O atom and the carboxy O—H atom, closing anS(6) loop. In the crystal, molecules are assembled by stacking interactions [centroid–centroid distance between the benzene and pyran rings = 3.844 (3) Å] and C—H...O hydrogen bonds, generating a three-dimensional network. Short contacts are also observed between the carboxy O and C atoms [C=O...C=O = 3.002 (3) Å].
Innovative behaviour in the workplace
Authors: Wojtczuk-Turek Agnieszka , Turek Dariusz
Published: July 2015

Purpose

– The purpose of this paper is to describe and explain the manner in which HR system’s flexibility, in combination with employees’ individual flexibility (IF) and their positive character traits, such as: optimism, hope, resistance or self-efficacy (which comprise psychological capital (PsychCap)), allow to predict employees’ readiness to display innovative behaviors in the workplace.

Design/methodology/approach

– A quantitative research methodology was adopted which resulted in the development of a both self-administered online survey instrument (n=166) and employees students in the postgraduate program at the Warsaw School of Economics (n=70). Using a national database of service companies, a random sample of 700 e-mail addresses was generated and respondents were invited to participate in the online survey. This resulted in the completion of 166 online surveys, representing a response rate of 26 percent. The second group of respondents consisted of 70 employees from different organizations in Poland.

Findings

– On the basis of the analyses it was shown that HR flexibility (HRF) and IF are a generally weak predictor of innovative behaviors. However, in a situation when PsychCap is set to be a mediator, these variables allow to predict innovative work behavior.

Originality/value

– Research on the relation of HRF to innovative behaviors has not been sufficiently clarified so far. The achieved results shed new light on the relations of these two variables and indicate that HRF does not translate directly into behaviors of the personnel. However, it should be noted that the relationship of these variables are of indirect nature.
Selecting ideas for new product development
Authors: Cui Geng , Peng Ling , Florès Laurent Pierre
Published: July 2015

Purpose

– New product concept screening, i.e., selecting a few viable innovative concepts from numerous candidates, involves high stakes and is complicated and resource intensive. Over the years, there has been heated debate about the relative merit of monadic (sequential) tests vs that of preference-based paired comparisons. The paper aims to discuss these issues.

Design/methodology/approach

– This study proposes the Generalizability Theory as a framework to assess and compare the performance of traditional monadic test with the Adaptive Concept Screening (ACS) in terms of their testing results and psychometric quality.

Findings

– Using 50 yogurt concepts and two independent groups of respondents, the results indicate that ACS requires a significant smaller sample of respondents to achieve a necessary minimum G coefficient for decision making. Moreover, ACS offers a more discriminating and reliable solution for early stage concept screening as manifested by a higher G coefficient and greater percentage of variance due to the selected concepts given the same sampling design.

Practical implications

– The results lend strong support to ACS as a more cost-effective method for screening new product concepts and the Generalizability Theory as a systematic framework for assessing concept testing methods.

Originality/value

– This study adopts the Generalizability Theory framework to assess the validity of new product concept screening method.