bluuebunny/crossref_metadata_2025 huggingface dataset:
Repression of the cob operon of Salmonella typhimurium by adenosylcobalamin is influenced by mutations in the pdu operon
Authors: Ailion M , Roth J R
Published: November 2016

The cob operon encodes functions needed for the biosynthesis of adenosylcobalamin (Ado-B12). Propanediol induces transcription of the cob operon and the neighboring pdu operon, which encodes proteins for the B12-dependent degradation of propanediol. Expression of the cob (but not the pdu) operon is repressed by exogenous cyanocobalamin. Evidence is provided that cob operon repression is signaled by internally generated Ado-B12, which can be formed either by the CobA adenosyltransferase or by an alternative adenosyltransferase (AdoT) that we infer is encoded within the pdu operon. Repression is also affected by mutations (AdoB) in the pdu operon that map upstream of the inferred pdu adenosyltransferase gene. Such mutations allow cobalamin to mediate repression at concentrations 100-fold lower than those needed in the wild type. It is proposed that these mutations eliminate a component of the propanediol dehydratase enzyme complex (PduCDE) and that this complex competes with the cob regulatory mechanism for a limited supply of Ado-B12.
Ferrous iron uptake by a magnesium transport system is toxic for Escherichia coli and Salmonella typhimurium
Authors: Hantke K
Published: November 2016

At low magnesium concentrations, Escherichia coli and Salmonella typhimurium LT2 accumulate ferrous iron independent of the ferrous iron transport system feo. Mutant strains with mutations in the magnesium transport gene corA accumulated less ferrous iron than the parent strains. corA+ and corA strains also differed in their sensitivity to ferrous iron under oxic conditions. corA mutants were more resistant to ferrous iron than their parent corA+ strains. Part of the ferrous iron accumulated can be chased by the addition of magnesium. Much less iron was chased when ferric iron was taken up by the siderophore ferrichrome. These results may indicate that the intracellular metabolism of the iron taken up by these systems differs and that it depends on the uptake route of the iron.
Genetic diversity in temperate bacteriophages of Streptococcus pyogenes: identification of a second attachment site for phages carrying the erythrogenic toxin A gene
Authors: McShan W M , Ferretti J J
Published: November 2016

Bacteriophage T12, the prototypic bacteriophage of Streptococcus pyogenes carrying the erythrogenic toxin A gene (speA), integrates into the bacterial chromosome at a gene for a serine tRNA (W. M. McShan, Y.-F. Tang, and J. J. Ferretti, Mol. Microbiol. 23:719-728, 1997). This phage is a member of a group of related temperate phages, and we show here that not all speA-carrying phages in this group use the same attachment site for integration into the bacterial chromosome. Additionally, other phages in the group use the same serine tRNA gene attachment site as phage T12 and yet do not carry speA. The evidence suggests that recombination between phage genomes has been an important means of generating diversity and disseminating virulence-associated genes like speA.
Carbon starvation of Salmonella typhimurium does not cause a general increase of mutation rates
Authors: Hughes D , Andersson D I
Published: November 2016

Mutation rates in bacteria can vary depending on the genetic target studied and the specific growth conditions of the cells. Here, two different methods were used to determine how rates of mutation to antibiotic resistance, auxotrophy, and prototrophy were influenced by carbon starvation on agar plates. The rate of mutation to rifampin resistance was increased by starvation as measured by fluctuation tests, similar to what has been reported previously for Escherichia coli. In contrast, the rates of mutation to various types of auxotrophy were unaffected or decreased as measured by both fluctuation tests and a repeated-streaking procedure. Similarly, the rates of reversion to prototrophy of his and lac nonsense and missense mutations were unaffected by starvation. Thus, mutation rates of different genetic targets can be affected differently by starvation and we conclude that carbon starvation is not generally mutagenic in Salmonella typhimurium.
cis-Acting sequences required for light-responsive expression of the psbDII gene in Synechococcus sp. strain PCC 7942
Authors: Anandan S , Golden S S
Published: November 2016

We analyzed the sequences required for promoter activity and high-light responsiveness of the psbDII gene in the cyanobacterium Synechococcus sp. strain PCC 7942 by using transcriptional fusions to a lacZ reporter gene. The basal promoter drives high constitutive expression, although no canonical -35 element is evident. The smallest fragment that showed clear light-responsive expression extends from -38 to +160, which includes 52 bp of the psbDII open reading frame. Sequences downstream from the promoter, within the untranslated leader region from +11 to +24, were required for high-light induction.
Methylthiol:coenzyme M methyltransferase from Methanosarcina barkeri, an enzyme of methanogenesis from dimethylsulfide and methylmercaptopropionate
Authors: Tallant T C , Krzycki J A
Published: November 2016

During growth on acetate, Methanosarcina barkeri expresses catabolic enzymes for other methanogenic substrates such as monomethylamine. The range of substrates used by cells grown on acetate was further explored, and it was found that cells grown on acetate also converted dimethylsulfide (DMS) and methylmercaptopropionate (MMPA) to methane. Cells or extracts of cells grown on trimethylamine or methanol did not utilize either DMS or MMPA. During growth on acetate, cultures demethylated MMPA, producing methane and mercaptopropionate. Extracts of acetate-grown cells possessed DMS- and MMPA-dependent coenzyme M (CoM) methylation activities. The activity peaks of CoM methylation with either DMS or MMPA coeluted upon gel permeation chromatography of extracts of acetate-grown cells consistent with an apparent molecular mass of 470 kDa. A 480-kDa corrinoid protein, previously demonstrated to be a CoM methylase but otherwise of unknown physiological function, was found to methylate CoM with either DMS or MMPA. MMPA was demethylated by the purified 480-kDa CoM methylase, consuming 1 mol of CoM and producing 1 mol of mercaptopropionate. DMS was demethylated by the purified protein, consuming 1 mol of CoM and producing 1 mol of methanethiol. The methylthiol:CoM methyltransferase reaction could be initiated only with the enzyme-bound corrinoid in the methylated state. CoM could demethylate, and DMS and MMPA could remethylate, the corrinoid cofactor. The monomethylamine corrinoid protein and the A isozyme of methylcobamide:CoM methyltransferase (proteins homologous to the two subunits comprising the 480-kDa CoM methylase) did not catalyze CoM methylation with methylated thiols. These results indicate that the 480-kDa corrinoid protein functions as a CoM methylase during methanogenesis from DMS or MMPA.
Designing recombinant Pseudomonas strains to enhance biodesulfurization
Authors: Gallardo M E , Ferrández A , De Lorenzo V , García J L , Díaz E
Published: November 2016

The dsz biodesulfurization cluster from Rhodococcus erythropolis IGTS8 has been engineered under the control of heterologous broad-host-range regulatory signals to alleviate the mechanism of sulfur repression, and it was stably inserted into the chromosomes of different Pseudomonas strains. The recombinant bacteria were able to desulfurize dibenzothiophene more efficiently than the native host. Furthermore, these new biocatalysts combine relevant industrial and environmental traits, such as production of biosurfactants, with the enhanced biodesulfurization phenotype.
The rpoN (sigma54) gene from Listeria monocytogenes is involved in resistance to mesentericin Y105, an antibacterial peptide from Leuconostoc mesenteroides
Authors: Robichon D , Gouin E , Débarbouillé M , Cossart P , Cenatiempo Y , Héchard Y
Published: November 2016

To gain insight into the mode of action of mesentericin Y105, a bacteriocin bactericidal agent against Listeria monocytogenes, we undertook to identify the listerial factors mediating this susceptibility by using a genetic approach. Transposon mutants resistant to the bacteriocin were obtained. One of them corresponded to a transposon insertion in a gene (rpoN) encoding a putative protein (447 amino acids) with strong homologies to alternative transcriptional sigma54 factors, including that of Bacillus subtilis (38% identity). Complementation experiments with the wild-type rpoN gene demonstrated that the insertion in rpoN was responsible for the resistance phenotype in L. monocytogenes. Moreover, expression of the L. monocytogenes rpoN gene in an rpoN mutant strain of B. subtilis promoted transcription of a sigma54-dependent operon in the presence of the associated regulator. These results demonstrate that the L. monocytogenes rpoN gene encodes a new sigma54 factor.
Regulation of the Escherichia coli tna operon: nascent leader peptide control at the tnaC stop codon
Authors: Konan K V , Yanofsky C
Published: November 2016

Expression of the tryptophanase (tna) operon of Escherichia coli is regulated by catabolite repression and by tryptophan-induced transcription antitermination at Rho-dependent termination sites in the leader region of the operon. Tryptophan induction is dependent on translation of a short leader peptide coding region, tnaC, that contains a single, crucial tryptophan codon. Recent studies suggest that during induction, the TnaC leader peptide acts in cis on the translating ribosome to inhibit its release at the tnaC stop codon. In the present study we use a tnaC-UGA-'lacZ construct lacking the tnaC-tnaA spacer region to analyze the effect of TnaC synthesis on the behavior of the ribosome that translates tnaC. The tnaC-UGA-'lacZ construct is not expressed significantly in the presence or absence of inducer. However, it is expressed in the presence of UGA suppressors, or when the structural gene for polypeptide release factor 3 is disrupted, or when wild-type tRNATrP is overproduced. In each situation, tnaC-UGA-'lacZ expression is reduced appreciably by the presence of inducing levels of tryptophan. Replacing the tnaC UGA stop codon with a sense codon allows considerable expression, which is also reduced, although to a lesser extent, by the addition of tryptophan. Inhibition by tryptophan is not observed when Trp codon 12 of tnaC is changed to a Leu codon. Overexpression of tnaC in trans from a multicopy plasmid prevents inhibition of expression by tryptophan. These results support the hypothesis that the TnaC leader peptide acts in cis to alter the behavior of the translating ribosome.
Roles of the tnaC-tnaA spacer region and Rho factor in regulating expression of the tryptophanase operon of Proteus vulgaris
Authors: Kamath A V , Yanofsky C
Published: November 2016

To localize the DNA regions responsible for basal-level and induced expression of the tryptophanase (tna) operon of Proteus vulgaris, short deletions were introduced in the 115-bp spacer region separating tnaC, the leader peptide coding region, from tnaA. Deletions were incorporated into a tnaA'-'lacZ reporter construct containing the intact tna promoter-leader region. Expression was examined in Escherichia coli. Deletions that removed 28 to 30 bp from the region immediately following tnaC increased basal-level expression about threefold and allowed threefold induction by 1-methyltryptophan. A deletion removing 34 bp from the distal segment of the leader permitted basal and induced expression comparable to that of the parental construct. The mutant with the largest spacer deletion, 89 bp, exhibited a 30-fold increase in basal-level expression, and most importantly, inducer presence reduced operon expression by ca. 60%. Replacing the tnaC start codon or replacing or removing Trp codon 20 of tnaC of this deletion derivative eliminated inducer inhibition of expression. These findings suggest that the spacer region separating tnaC and tnaA is essential for Rho action. They also suggest that juxtaposition of the tnaC stop codon and the tnaA ribosome binding site in the 89-bp deletion derivative allows the ribosome that has completed translation of tnaC to inhibit translation initiation at the tnaA start codon when cells are exposed to inducer. These findings are consistent with results in the companion article that suggest that inducer allows the TnaC peptide to inhibit ribosome release at the tnaC stop codon.
Calcium is required for swimming by the nonflagellated cyanobacterium Synechococcus strain WH8113
Authors: Pitta T P , Sherwood E E , Kobel A M , Berg H C
Published: November 2016

The marine cyanobacterium Synechococcus strain WH8113 swims in the absence of any recognizable organelles of locomotion. We have found that calcium is required for this motility. Cells deprived of calcium stopped swimming, while addition of calcium completely restored motility. No other divalent ions tested could replace calcium. Terbium, a lanthanide ion, blocked motility even when calcium was present at 10(5)-fold-higher concentrations, presumably by occupying calcium binding sites. Calcium chelators, EGTA or EDTA, blocked motility, even when calcium was present at 25-fold-higher concentrations, presumably by acting as calcium ionophores. Finally, motility was blocked by verapamil and nitrendipine, molecules known to block voltage-gated calcium channels of eukaryotic cells by an allosteric mechanism. These results suggest that a calcium potential is involved in the mechanism of motility.
Effect of an evidence-based website on healthcare usage: an interrupted time-series study
Authors: Spoelman Wouter A , Bonten Tobias N , de Waal Margot W M , Drenthen Ton , Smeele Ivo J M , Nielen Markus M J , Chavannes Niels H
Published: November 2016

Objectives

Healthcare costs and usage are rising. Evidence-based online health information may reduce healthcare usage, but the evidence is scarce. The objective of this study was to determine whether the release of a nationwide evidence-based health website was associated with a reduction in healthcare usage.

Design

Interrupted time series analysis of observational primary care data of healthcare use in the Netherlands from 2009 to 2014.

Setting

General community primary care.

Population

912 000 patients who visited their general practitioners 18.1 million times during the study period.

Intervention

In March 2012, an evidence-based health information website was launched by the Dutch College of General Practitioners. It was easily accessible and understandable using plain language. At the end of the study period, the website had 2.9 million unique page views per month.

Main outcomes measures

Primary outcome was the change in consultation rate (consultations/1000 patients/month) before and after the release of the website. Additionally, a reference group was created by including consultations about topics not being viewed at the website. Subgroup analyses were performed for type of consultations, sex, age and socioeconomic status.

Results

After launch of the website, the trend in consultation rate decreased with 1.620 consultations/1000 patients/month (p<0.001). This corresponds to a 12% decline in consultations 2 years after launch of the website. The trend in consultation rate of the reference group showed no change. The subgroup analyses showed a specific decline for consultations by phone and were significant for all other subgroups, except for the youngest age group.

Conclusions

Healthcare usage decreased by 12% after providing high-quality evidence-based online health information. These findings show that e-Health can be effective to improve self-management and reduce healthcare usage in times of increasing healthcare costs.
Extreme ultraviolet spectra of highly charged Fe ions in the laboratory versus the excitation of spectra in astrophysical environments
Authors: Träbert Elmar
Published: November 2016

The ASOS meetings address atomic spectra and oscillator strengths for astrophysics and laboratory plasmas. Based on examples of Fe spectra from foil-excited ion beams and electron beam ion traps, some practical problems of laboratory studies using these tools in support of astrophysical observations are discussed.
Insiders and outsiders: INHIGEO seen from the sidelines
Authors: Rudwick Martin
Published: November 2016

This paper is, without apology, a sketch of my own professional trajectory from geologist to historian of geology, in relation to the history of INHIGEO. Although I was invited to its inaugural meeting in 1967 and elected as a corresponding member in 1970, my participation in its activities has been intermittent, mainly because its dominant historiography has been shaped more by its roots in the geological community than by its affinities with historians of the sciences. I illustrate this by outlining my emphasis on ‘re-treading’ the fieldwork of past geologists in terms of the evidence and ideas of their time, rather than with pervasive ‘presentist’ or anachronistic reference to modern scientific knowledge. I conclude that both geologists and historians are, in complementary senses, ‘insiders’ with much to offer to the ‘outsiders’ in the other group.
nor-BNI Antagonism of Kappa Opioid Agonist-Induced Reinstatement of Ethanol-Seeking Behavior
Authors: Harshberger Erin , Gilson Emily A. , Gillett Kelli , Stone Jasmine H. , El Amrani Laila , Valdez Glenn R.
Published: November 2016

Recent work suggests that the dynorphin (DYN)/kappa opioid receptor (KOR) system may be a key mediator in the behavioral effects of alcohol. The objective of the present study was to examine the ability of the KOR antagonist norbinaltorphimine (nor-BNI) to attenuate relapse to ethanol seeking due to priming injections of the KOR agonist U50,488 at time points consistent with KOR selectivity. Male Wistar rats were trained to self-administer a 10% ethanol solution, and then responding was extinguished. Following extinction, rats were injected with U50,488 (0.1–10 mg/kg, i.p.) or saline and were tested for the reinstatement of ethanol seeking. Next, the ability of the nonselective opioid receptor antagonist naltrexone (0 or 3.0 mg/kg, s.c.) and nor-BNI (0 or 20.0 mg/kg, i.p.) to block U50,488-induced reinstatement was examined. Priming injections U50,488 reinstated responding on the previously ethanol-associated lever. Pretreatment with naltrexone reduced the reinstatement of ethanol-seeking behavior. nor-BNI also attenuated KOR agonist-induced reinstatement, but to a lesser extent than naltrexone, when injected 24 hours prior to injections of U50,488, a time point that is consistent with KOR selectivity. While these results suggest that activation of KORs is a key mechanism in the regulation of ethanol-seeking behavior, U50,488-induced reinstatement may not be fully selective for KORs.
The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure
Authors: Lucena Fausto , Barros Allan Kardec , Ohnishi Noboru
Published: November 2016

Congestive heart failure (CHF) is a cardiac disease associated with the decreasing capacity of the cardiac output. It has been shown that the CHF is the main cause of the cardiac death around the world. Some works proposed to discriminate CHF subjects from healthy subjects using either electrocardiogram (ECG) or heart rate variability (HRV) from long-term recordings. In this work, we propose an alternative framework to discriminate CHF from healthy subjects by using HRV short-term intervals based on 256 RR continuous samples. Our framework uses a matching pursuit algorithm based on Gabor functions. From the selected Gabor functions, we derived a set of features that are inputted into a hybrid framework which uses a genetic algorithm andk-nearest neighbour classifier to select a subset of features that has the best classification performance. The performance of the framework is analyzed using both Fantasia and CHF database from Physionet archives which are, respectively, composed of 40 healthy volunteers and 29 subjects. From a set of nonstandard 16 features, the proposed framework reaches an overall accuracy of 100% with five features. Our results suggest that the application of hybrid frameworks whose classifier algorithms are based on genetic algorithms has outperformed well-known classifier methods.
Upconversion Luminescence and Magnetic Turning of NaLuF4:Yb3+/Tm3+/Gd3+ Nanoparticles and Their Application for Detecting Acriflavine
Authors: Hu Shigang , Cao Huiyi , Wu Xiaofeng , Zhan Shiping , Wu Qingyang , Tang Zhijun , Liu Yunxin
Published: November 2016

Fluorescent and magnetic bifunctional NaLuF4:Yb3+/Tm3+/Gd3+ nanocrystals were synthesized by the solvothermal method and subsequent surface modification. By changing the doping concentration of Gd3+, the shape, size, luminescent properties, and magnetic properties of the nanoparticles can be modulated. These NaLuF4:Yb3+/Tm3+/Gd3+ nanocrystals present efficient blue upconversion fluorescence and excellent paramagnetic property at room temperature. Based on the luminescence resonance energy transfer (LRET), upconversion nanoparticles (UCNPs) were confirmed to be an efficient fluorescent nanoprobe for detecting acriflavine. It is easy to derive the concentration of acriflavine from the Integral Intensity Ratio of Green (emission from acriflavine) to Blue (emission from UCNPs) fluorescent signals. Based on this upconversion fluorescent nanoprobe, the detection limit of acriflavine can reach up to 0.32 μg/mL.
Comparison of the Optical Quality between Small Incision Lenticule Extraction and Femtosecond Laser LASIK
Authors: Jin Ying , Wang Yan , Xu Lulu , Zuo Tong , Li Hua , Dou Rui , Zhang Jiamei
Published: November 2016

Purpose.To investigate the visual quality after SMILE and Femto-LASIK.Methods.About 123 eyes from 63 patients were enrolled in this study. The parameters were measured preoperatively and 1 week, 1 month, and 3 months postoperatively using Sirius System.Results.The MTF curve increase slightly from low to high frequency at 3 mm and 6 mm pupil diameter after SMILE surgery (P<0.05) during the follow-up time comparing with the preoperative values. And the SR has a significant increase at various pupil diameters as well (P<0.05). However, there was little increase for MTF at intermediate to high frequency at 3 mm pupil diameter after Femto-LASIK procedure (P<0.05). And the SR had only significant increase at 3 mm pupil diameter. Between SMILE and Femto-LASIK, there was no statistic difference both in MTF and SR (P>0.05) at 3 mm pupil diameter at vertical and horizontal meridian. However, significant difference was found in MTF at low to mediate frequency at 6 mm pupil diameter at vertical meridian at 1 week postoperatively (P<0.05).Conclusions.Both SMILE and Femto-LASIK show a great improvement in optical quality at small diameter. It was found that SMILE shows better optical quality than Femto-LASIK at larger pupil diameter, which might be good for the night vision.
A Unique Case of Pancreatic Mass due to Pancreatic Elastofibromatosis
Authors: Goyal Abhinav , Jain Deepanshu , Bhat Ishfaq , Singh Shailender
Published: November 2016

Elastofibroma is a benign tumor of the musculoskeletal system characterized by the abnormal accumulation of elastinophilic fibers. It has been classically described for subscapular region but has been reported in several musculoskeletal sites over the years and rarely even in the GI tract but never in pancreas. We therefore present the case of a 45-year-old female who presented with intermittent abdominal pain. CT of abdomen revealed 1.4 cm pancreatic neck lesion without peripancreatic lymphadenopathy. Endoscopic ultrasound (EUS) guided FNA was nondiagnostic. Surgical resection was performed with central pancreatectomy. Histopathology revealed well demarcated nodules of hypocellular collagen with abundant elastic fibers, characteristic of pancreatic elastofibroma. Treatment is not needed unless symptomatic and surgical resection is the preferred therapeutic option when indicated. This case adds another entity to the differential diagnosis of pancreatic mass lesions.
The In Vitro Antimicrobial Effects of Lavandula angustifolia Essential Oil in Combination with Conventional Antimicrobial Agents
Authors: de Rapper Stephanie , Viljoen Alvaro , van Vuuren Sandy
Published: November 2016

The paper focuses on the in vitro antimicrobial activity of Lavandula angustifolia Mill. (lavender) essential oil in combination with four commercial antimicrobial agents. Stock solutions of chloramphenicol, ciprofloxacin, nystatin, and fusidic acid were tested in combination with L. angustifolia essential oil. The antimicrobial activities of the combinations were investigated against the Gram‐positive bacterial strain Staphylococcus aureus (ATCC 6538) and Gram‐negative Pseudomonas aeruginosa (ATCC 27858) and Candida albicans (ATCC 10231) was selected to represent the yeasts. The antimicrobial effect was performed using the minimum inhibitory concentration (MIC) microdilution assay. Isobolograms were constructed for varying ratios. The most prominent interaction was noted when L. angustifolia essential oil was combined with chloramphenicol and tested against the pathogen P. aeruginosa (ΣFIC of 0.29). Lavendula angustifolia essential oil was shown in most cases to interact synergistically with conventional antimicrobials when combined in ratios where higher volumes of L. angustifolia essential oil were incorporated into the combination.
A Compact Novel Three-Port Integrated Wide and Narrow Band Antennas System for Cognitive Radio Applications
Authors: Kumar N. Anvesh , Gandhi A. S.
Published: November 2016

The design of a three-port radiating structure, integrating wide and narrow band antennas for cognitive radio applications, is presented. It consists of a UWB antenna for spectrum sensing and two narrow band antennas for wireless communication integrated on the same substrate. The UWB antenna covers the complete UWB spectrum (3.1 GHz to 10.6 GHz) approved by FCC. In the two narrow band antennas, each antenna presents dual bands. In particular, the first narrowband antenna resonates at 6.5 GHz, covering the frequency band between 6.36 GHz and 6.63 GHz, and at 9 GHz, covering the frequency band between 8.78 GHz and 9.23 GHz, presenting minimum return loss values of 28.3 dB at 6.5 GHz and 20.5 dB at 9 GHz, respectively. Similarly, the second one resonates at 7.5 GHz, covering the frequency band between 7.33 GHz and 7.7 GHz, and at 9.5 GHz, covering the frequency band between 9.23 GHz and 9.82 GHz, presenting minimum return loss values of 19.6 dB at 7.5 GHz and 28.8 dB at 9.5 GHz, respectively. Isolation among the three antennas is less than −20 dB over the UWB frequency spectrum. These antennas are realized on a FR4 substrate of dimensions 30 mm × 30 mm × 1.6 mm. Experimental results show a good agreement between the simulated and measured results.
The First Moment of Azimuthal Anisotropy in Nuclear Collisions from AGS to LHC Energies
Authors: Singha Subhash , Shanmuganathan Prashanth , Keane Declan
Published: November 2016

We review topics related to the first moment of azimuthal anisotropy (v1), commonly known as directed flow, focusing on both charged particles and identified particles from heavy-ion collisions. Beam energies from the highest available, at the CERN LHC, down to projectile kinetic energies per nucleon of a few GeV per nucleon, as studied in experiments at the Brookhaven AGS, fall within our scope. We focus on experimental measurements and on theoretical work where direct comparisons with experiment have been emphasized. The physics addressed or potentially addressed by this review topic includes the study of Quark Gluon Plasma and, more generally, investigation of the Quantum Chromodynamics phase diagram and the equation of state describing the accessible phases.
Focusing of Spotlight Tandem-Configuration Bistatic Data with Frequency Scaling Algorithm
Authors: Chen Shichao , Liu Ming , Wang Jun , Lu Fugang , Xing Mengdao
Published: November 2016

A frequency scaling (FS) imaging algorithm is proposed for spotlight bistatic SAR data processing. Range cell migration correction (RCMC) is realized through phase multiplication. The proposed algorithm is insensitive to the length of the baseline due to the high precision of the point target (PT) spectrum that we are based on. It is capable of handling bistatic SAR data with a large baseline to range ratio. The algorithms suitable for small and high squint angles are both discussed according to whether the range dependence of the second range compression (SRC) can be neglected or not. Simulated experiments validate the effectiveness of the proposed algorithm.
An Efficient Approach for Real-Time Prediction of Rate of Penetration in Offshore Drilling
Authors: Shi Xian , Liu Gang , Gong Xiaoling , Zhang Jialin , Wang Jian , Zhang Hongning
Published: November 2016

Predicting the rate of penetration (ROP) is critical for drilling optimization because maximization of ROP can greatly reduce expensive drilling costs. In this work, the typical extreme learning machine (ELM) and an efficient learning model, upper-layer-solution-aware (USA), have been used in ROP prediction. Because formation type, rock mechanical properties, hydraulics, bit type and properties (weight on the bit and rotary speed), and mud properties are the most important parameters that affect ROP, they have been considered to be the input parameters to predict ROP. The prediction model has been constructed using industrial reservoir data sets that are collected from an oil reservoir at the Bohai Bay, China. The prediction accuracy of the model has been evaluated and compared with the commonly used conventional artificial neural network (ANN). The results indicate that ANN, ELM, and USA models are all competent for ROP prediction, while both of the ELM and USA models have the advantage of faster learning speed and better generalization performance. The simulation results have shown a promising prospect for ELM and USA in the field of ROP prediction in new oil and gas exploration in general, as they outperform the ANN model. Meanwhile, this work provides drilling engineers with more choices for ROP prediction according to their computation and accuracy demand.
Unruptured Basilar Tip Aneurysm with Internal Septation: Coiling Implications?
Authors: Khalil Ayman , Kok Hong Kuan , Schembri Mark , Brennan Paul , Javadpour Mohsen , Thornton John , O’Hare Alan , Asadi Hamed
Published: November 2016

An internal septum within a basilar artery aneurysm is an infrequent anomaly and is very rarely reported in the literature. We report a 62-year-old lady that was incidentally diagnosed with basilar tip aneurysm. Further imaging with magnetic resonance imaging (MRI) revealed internal septation within this aneurysm which was later confirmed with digital subtraction angiography (DSA). She underwent coil embolisation, which involved technical manipulation of the microcatheter and the balloon to enable coiling of each separate aneurysm compartment. We present this case to illustrate the effect of this anatomical variation on the selection of endovascular treatment strategy.
Bounds on the Spectral Radius of a Nonnegative Matrix and Its Applications
Authors: Huang Danping , You Lihua
Published: November 2016

We obtain the sharp bounds for the spectral radius of a nonnegative matrix and then obtain some known results or new results by applying these bounds to a graph or a digraph and revise and improve two known results.
Noninvasive Positive Pressure Ventilation in Chronic Heart Failure
Authors: Jiang Hao , Han Yi , Xu Chenqi , Pu Jun , He Ben
Published: November 2016

Instruction and Objectives. Noninvasive positive pressure ventilation (NPPV) alleviates sleep-disordered breathing (SDB) and it may improve cardiac function in SDB patients. Because large randomized controlled trials directly evaluating the impact of NPPV on cardiac function are lacking, we conducted a meta-analysis of published data on effectiveness of NPPV in improving cardiac function in patients with chronic heart failure regardless of SDB presence.Methods. Controlled trials were identified in PubMed, OVID, and EMBASE databases. Both fixed and randomized models were used in meta-analysis with primary outcomes of left ventricular ejection fraction (LVEF).Results. Nineteen studies were included with a total of 843 patients. Compared to standard medical treatment (SMT) plus sham-NPPV or SMT only, NPPV plus SMT was associated with improvement in LVEF (weighted mean difference 5.34, 95% CI,[3.85,6.82];P<0.00001) and plasma brain natriuretic peptide (BNP) level (weighted mean difference −117.37, 95% CI,[-227.22,-7.52];P=0.04) and no influence on overall mortality (RR 1.00, 95% CI,[0.96,1.04];P=0.95).Conclusions. In the present meta-analysis, use of NPPV plus SMT improved LVEF and reduced plasma BNP level but did not improve overall mortality in patients with chronic heart failure.
Brief Overview on Nitinol as Biomaterial
Authors: Wadood Abdul
Published: November 2016

Shape memory alloys remember their shape due to thermoelastic martensitic phase transformation. These alloys have advantages in terms of large recoverable strain and these alloys can exert continuous force during use. Equiatomic NiTi, also known as nitinol, has a great potential for use as a biomaterial as compared to other conventional materials due to its shape memory and superelastic properties. In this paper, an overview of recent research and development related to NiTi based shape memory alloys is presented. Applications and uses of NiTi based shape memory alloys as biomaterials are discussed. Biocompatibility issues of nitinol and researchers’ approach to overcome this problem are also briefly discussed.
Antiviral Nanodelivery Systems: Current Trends in Acyclovir Administration
Authors: Hassan Haniza , Adam Siti Khadijah , Othman Fauziah , Shamsuddin Ahmad Fuad , Basir Rusliza
Published: November 2016

Poor bioavailability of acyclovir in the treatment of viral infections remains one of the major drug delivery concerns of pharmaceutical manufacturers and researchers. Nanoparticulate systems have been exploited with the aim of improving the current pharmacological limitations of acyclovir administration. In fact, nanoparticles do offer many advantages, especially in terms of their physicochemical stability and sustained-release properties. Besides, they are made of biocompatible materials, which are nontoxic to cells. Acyclovir has been a focus since the last decade as one of the low bioavailability drug models loaded in various types of newly synthesized drug delivery vehicles. In this review, compositions and formulations of nanosized acyclovir particles, as well as their stability and pharmacokinetic profile, are discussed in further detail.
Results from 10 Years of a CBT Pain Self-Management Outpatient Program for Complex Chronic Conditions
Authors: Boschen Kathryn A. , Robinson Edward , Campbell Kent A. , Muir Sarah , Oey Elvina , Janes Kristen , Fashler Samantha R. , Katz Joel
Published: November 2016

Background.Traditional unimodal interventions may be insufficient for treating complex pain, as they do not address cognitive and behavioural contributors to pain. Cognitive Behavioural Therapy (CBT) and physical exercise (PE) are empirically supported treatments that can reduce pain and improve quality of life.Objectives.To examine the outcomes of a pain self-management outpatient program based on CBT and PE at a rehabilitation hospital in Toronto, Ontario.Methods.The pain management group (PMG) consisted of 20 sessions over 10 weeks. The intervention consisted of four components: education, cognitive behavioural skills, exercise, and self-management strategies. Outcome measures included the sensory, affective, and intensity of pain experience, depression, anxiety, pain disability, active and passive coping style, and general health functioning.Results.From 2002 to 2011, 36 PMGs were run. In total, 311 patients entered the program and 214 completed it. Pairedt-tests showed significant pre- to posttreatment improvements in all outcomes measured. Patient outcomes did not differ according to the number or type of diagnoses. Both before and after treatment, women reported more active coping than men.Discussion.The PMGs improved pain self-management for patients with complex pain. Future research should use a randomized controlled design to better understand the outcomes of PMGs.
Chitosan-Based Coating with Antimicrobial Agents: Preparation, Property, Mechanism, and Application Effectiveness on Fruits and Vegetables
Authors: Xing Yage , Xu Qinglian , Li Xingchen , Chen Cunkun , Ma Li , Li Shaohua , Che Zhenming , Lin Hongbin
Published: November 2016

Chitosan coating is beneficial to maintaining the storage quality and prolonging the shelf life of postharvest fruits and vegetables, which is always used as the carrier film for the antimicrobial agents. This review focuses on the preparation, property, mechanism, and application effectiveness on the fruits and vegetables of chitosan-based coating with antimicrobial agents. Chitosan, derived by deacetylation of chitin, is a modified and natural biopolymer as the coating material. In this article, the safety and biocompatible and antimicrobial properties of chitosan were introduced because these attributes are very important for its application. The methods to prepare the chitosan-based coating with antimicrobial agents, such as essential oils, acid, and nanoparticles, were developed by other researchers. Meanwhile, the application of chitosan-based coating is mainly due to its antimicrobial activity and other functional properties, which were investigated, introduced, and analyzed in this review. Furthermore, the surface and mechanical properties were also investigated by researchers and concluded in this article. Finally, the effects of chitosan-based coating on the storage quality, microbial safety, and shelf life of fruits and vegetables were introduced. Their results indicated that chitosan-based coating with different antimicrobial agents would probably have wide prospect in the preservation of fruits and vegetables in the future.
Yonjung High-Speed Railway Bridge Assessment Using Output-Only Structural Health Monitoring Measurements under Train Speed Changing
Authors: Kaloop Mosbeh R. , Hu Jong Wan , Sayed Mohamed A.
Published: November 2016

Yonjung Bridge is a hybrid multispan bridge that is designed to transport high-speed trains (HEMU-430X) with maximum operating speed of 430 km/h. The bridge consists of simply supported prestressed concrete (PSC) and composite steel girders to carry double railway tracks. The structural health monitoring system (SHM) is designed and installed to investigate and assess the performance of the bridge in terms of acceleration and deformation measurements under different speeds of the passing train. The SHM measurements are investigated in both time and frequency domains; in addition, several identification models are examined to assess the performance of the bridge. The drawn conclusions show that the maximum deflection and acceleration of the bridge are within the design limits that are specified by the Korean and European codes. The parameters evaluation of the model identification depicts the quasistatic and dynamic deformations of PSC and steel girders to be different and less correlated when higher speeds of the passing trains are considered. Finally, the variation of the frequency content of the dynamic deformations of the girders is negligible when high speeds are considered.
Speaker Recognition Using Wavelet Cepstral Coefficient, I-Vector, and Cosine Distance Scoring and Its Application for Forensics
Authors: Lei Lei , Kun She
Published: November 2016

An important application of speaker recognition is forensics. However, the accuracy of speaker recognition in forensic cases often drops off rapidly because of the ill effect of ambient noise, variable channel, different duration of speech data, and so on. Therefore, finding a robust speaker recognition model is very important for forensics. This paper builds a new speaker recognition model based on wavelet cepstral coefficient (WCC), i-vector, and cosine distance scoring (CDS). This model firstly uses the WCC to transform the speech into spectral feature vecors and then uses those spectral feature vectors to train the i-vectors that represent the speeches having different durations. CDS is used to compare the i-vectors to give out the evidence. Moreover, linear discriminant analysis (LDA) and the within-class covariance normalization (WCNN) are added to the CDS algorithm to deal with the channel variability problem. Finally, the likelihood ratio estimates the strength of the evidence. We use the TIMIT database to evaluate the performance of the proposed model. The experimental results show that the proposed model can effectively solve the troubles of forensic scenario, but the time cost of the method is high.
Intrahepatic Cholestasis of Pregnancy with Severe Elevation of Bile Acids in the Setting of Acute Hepatitis C Infection
Authors: Lawlor Megan L. , Critchfield Agatha S.
Published: November 2016

Intrahepatic cholestasis of pregnancy (ICP) is a complication of pregnancy resulting in elevation of serum bile acid levels. ICP is often associated with underlying liver disease, including hepatitis C. Bile acids in relationship to the acute infection of hepatitis C virus have not yet been delineated in the literature. A 26-year-old gravida 4 para 2103 with dichorionic, diamniotic twin gestation and history of intravenous drug abuse developed ICP in the setting of acute hepatitis C infection. In addition to clinical symptoms of pruritus and right upper quadrant pain, she developed severe elevation in bile acids, 239 micromol/L, and transaminitis aspartate aminotransferase 1033 U/L, and alanine aminotransferase 448 U/L. She received ursodeoxycholic acid and antenatal testing was performed. Patient delivered vaginally at 33-week gestation following preterm rupture of membranes. Neonates were admitted to NICU and had uncomplicated neonatal courses. In the setting of ICP with significant transaminitis and severe elevation of bile acids, consideration of acute viral hepatitis is important, especially considering the worsening opioid epidemic and concurrent increase in intravenous drug use in the United States. Further study is needed regarding the acute form of HCV infection and its effect on ICP and associated bile acids.
Giant Coronary Artery Aneurysm Causing Acute Anterior Myocardial Infarction
Authors: Yanık Ahmet , Arslan Uğur , Akçay Murat , Menekşe Serdar , Yazgan Uğur Gökmen
Published: November 2016

A 70-year-old man with hypertension was admitted to our coronary ICU with acute anterior MI. Emergent primary PCI was planned and coronary angiography was performed. LAD artery was totally occluded in the proximal segment just after a huge 32 × 26 mm sized aneurysm. Emergent CABG operation was performed in 75 minutes because of multivessel disease including the RCA and left circumflex artery. Aneurysm was ligated and coronary bypass was performed using LIMA and saphenous grafts. The postoperative course of the patient was uneventful. He was discharged with medical therapy including ASA, clopidogrel, and atorvastatin. He was asymptomatic at his polyclinic visit in the first month.
The Association between VDR Gene Polymorphisms and Diabetic Retinopathy Susceptibility: A Systematic Review and Meta-Analysis
Authors: Zhang Yun , Xia Wei , Lu Ping , Yuan Huijuan
Published: November 2016

Aims. Studies on the associations of vitamin D receptor (VDR) gene polymorphisms with diabetic retinopathy (DR) susceptibility reported conflicting results. A systematic meta-analysis was undertaken to clarify this topic.Methods. A systematic search of electronic databases (PubMed, EMBASE, and CNKI) was carried out until March 31, 2016. The pooled odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of the association.Results. A total of 7 studies fulfilling the inclusion criteria were included in this meta-analysis (649 cases and 707 controls). Pooled ORs showed a significant association between FokI polymorphism and DR risk in all the four genetic models (OR=1.612(1.354~1.921), 1.988 (1.481~2.668), 1.889 (1.424~2.505), and 2.674 (1.493~4.790) in allelic, dominant, recessive, and additive models, resp.,PZ<0.01), but not for TaqI or BsmI polymorphism (PZ>0.05). Similar results were found in the subgroup analysis. Sensitivity analysis indicated that the results were relatively stable and reliable. Results of Begg’s and Egger’s tests suggested a lack of publication bias.Conclusions. Our meta-analysis demonstrated that DR was significantly associated with VDR gene FokI polymorphism. However, due to the relatively small sample size in this meta-analysis, further studies with a larger sample size should be done to confirm the findings.
A Silent and Chronic Complication of Percutaneous Endoscopic Gastrostomy Tube: Small Bowel Enterocutaneous Fistula
Authors: Cheung Sai Wah
Published: November 2016

Percutaneous endoscopic gastrostomy (PEG) has gradually gained the popularity since its invention and become the most preferred method for gastrostomy insertion in recent years. PEG is associated with lower morbidity and mortality and has the advantages of being minimally invasive and more convenient over the conventional open gastrostomy. However, significant rates of major complication still occur. Enterocutaneous fistula is one of the key complications that can be easily neglected due to its asymptomatic nature. We present a case of small bowel enterocutaneous fistula which was only found 8 years after the PEG insertion, being diagnosed after the longest duration of delay in diagnosis reported in literature.
Effects of Different Raw Materials in the Synthesis of Boehmite andγ- andα-Alumina
Authors: Padilla Isabel , López-Andrés Sol , López-Delgado Aurora
Published: November 2016

Two alumina polymorphs, the metaestableγ-Al2O3and the stableα-Al2O3, were obtained from thermal treatment of the precursorγ-AlOOH (boehmite). This precursor was prepared by a precipitation method employing different raw materials in order to study their effect on the synthesis process and several characteristics of the materials, such as the crystallite size, the thermal behavior, and the surface area. Aluminum chloride (AlCl3·6H2O) and an aluminum waste were used as the source of aluminum. A 1 M NaOH solution and a 1 M n-butylamine solution were used as alkalizing agents, due to their strong and weak alkaline characteristics, respectively. The XRD profiles of the boehmites obtained from waste show lower crystallinity than samples obtained from aluminum chloride. The content of water, from TG studies, was higher in the samples obtained from waste, which fit well with the smaller crystallite size. The use of n-butylamine as alkalizing agent favors the formation ofγ-alumina with higher surface area (177.2 cm2 g−1, for aluminum waste, and 159.4 cm2 g−1, for aluminum pure reagent). The temperature of transformation from gamma to alpha, from DTA results, is higher for samples obtained from the waste, and accordingly the presence of impurities in the waste stabilizes the metastable alumina phase.
Lyme Carditis: An Interesting Trip to Third-Degree Heart Block and Back
Authors: Afari Maxwell Eyram , Marmoush Fady , Rehman Mobeen Ur , Gorsi Umama , Yammine Joseph F.
Published: November 2016

Carditis is an uncommon presentation of the early disseminated phase of Lyme disease. We present the case of a young female who presented with erythema migrans and was found to have first-degree heart block which progressed to complete heart block within hours. After receiving ceftriaxone, there was complete resolution of the heart block in sequential fashion. Our case illustrates the importance of early recognition and anticipation of progressive cardiac conduction abnormalities in patients presenting with Lyme disease.