bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Determination of the Tensile Strength of Fused Deposition Modeling Parts
Authors: Savvakis K. , Petousis M. , Vairis A. , Vidakis N. , Bikmeyev A. T.
Published: June 2016

Acrylonitrile–butadiene–styrene (ABS) is a popular engineering thermoplastic and it is the most common material used in fused deposition modeling (FDM) technology. This technology is nowadays used for the production of prototypes and functional parts as well. It is therefore critical to know the mechanical properties of these parts, which, is as expected different from their nominal values.

In this work the tensile strength of parts build with the FDM process is measured. ABS and ABS plus parts were built with different building parameters and were tested according to the ASTM D638-02a standard on a Schenk Trebel Co. tensile test machine. It was found that the building direction does not significantly influence the tensile strength of the parts, although the parts were anisotropic, as expected. Parts build with larger layer thickness showed lower tensile strength. The average deviation between nominal and experimental tensile strength was about 15% for the ABS and about 42% for the ABS plus material. The ABS plus showed on average 9% higher strength than ABS.
PowerGen Gas Turbine Losses and Condition Monitoring: A Loss Data Based Study
Authors: Zhou Bin
Published: June 2016

In-situ condition monitoring (CM) is a crucial element in protection and predictive maintenance of large rotating Power-Gen equipment such as gas turbines or steam turbines. In this work, selected gas turbine loss events occurring during a recent ten-year period at FM Global clients’ power generation plants were evaluated. For each loss event, a loss scenario or a chain of failures was outlined after investigating the available loss record. These loss events were then categorized based on the nature of the associated loss scenario. The study subsequently focused on the variables that could be monitored in real time to detect the abnormal turbine operating conditions, such as vibration characteristics, temperature, pressure, quality of working fluids and material degradations. These groups of condition monitoring variables were then matched with detectable failures in each loss event and prioritized based on their effectiveness for failure detection and prevention. The detectable loss events and the associated loss value were used in this evaluation process. The study finally concluded with a summary of findings and path-forward actions.
Effect of Scratch on the Mechanical Property of Injection Moldings
Authors: Liao Mengyuan , Murakami Masuo , Inoya Hiroyuki , Yang Yuqiu , Hamada Hiroyuki
Published: June 2016

As well known that material’s scratch behavior/resistance is considering as a kind of surface toughness parameter, which can affect product’s appearance quality and mechanical property reduction. Material’s surface scratch damage may also accelerate critical fracture existence in following mechanical test process.

In this paper, dumbbell and plate samples of neat polycarbonate (PC) and 20wt% of glass fiber (GF) additive corresponding GF/PC composite were fabricated by injection molding technology. Basically, scratch damage performance was investigated by applying various scratch depths in dumbbell sample thickness direction following with tensile property change discussion. Initially, cross-section of scratch path in samples was observed to investigate various scratch parameters’ effect on scratch damage. Afterwards, dumbbell tension, plate’s drop weight impact test and bending test were conducted. Finally, dumbbell sample tension’s brittle fracture and plate’s impact damage tolerance were discussed based on tension strain, impact energy absorption and fractural appearance. The results indicates that material’s critical scratch depth could make sample’s tension fracture change from ductile to brittle, affecting material’s failure early-warming. Additionally, PC material with surface damage would decrease the energy absorption during plate bending process bearing smaller maximum load and deflection.
An Ethical Roadmap for Engineering Participatory Design and Sociotechnical Participation: A Manufacturing Case Study
Authors: Townsend Victoria , Boulos Pierre , Urbanic Jill
Published: June 2016

Participatory design (PD) is a sociotechnical approach grounded in mutual learning between various stakeholders in a design process. The PD literature emphasizes that authentic participation requires a critical ethical foundation, which, in turn, requires designers to be aware of this ethical foundation and bring it to bear on the design process. Since this is an emerging field in engineering, and since the ethical foundation is critical, it is important for engineers to seek clarity around the ethical considerations for utilizing PD and other sociotechnical methods involving participation. The purpose of the research presented here is to contribute to this clarity, in the context of manufacturing systems design, with the following question: what are the ethical considerations involved in participatory design, in engineering research and practice? To answer this, a case study research methodology is positioned as a nexus between research and practice. A roadmap of ethical considerations relating PD and manufacturing is developed by triangulating between internationally accepted research ethics principles, a professional engineering code of ethics, and an industrial case study with eight participants engaged in PD. This ethical roadmap is useful to engineering researchers and practitioners when using PD and sociotechnical approaches where participation is involved, to encourage a high standard of ethical practice and supporting theory.
In-Plane Thermal Conductivities of CFRP Composites Interleaved With Dissimilar Conductive Media
Authors: Bever Alaina M. , Levy-Wendt Benjamin L. , del Rosario Vittorio , Pentz James A. , Han Yen-Lin , Shih Frank J.
Published: June 2016

Four types of carbon fiber reinforced polymer (CFRP) specimens were prepared with prepregs. Three of the four composite specimens have embedded dissimilar material sheets intended to improve in-plane thermal conductivities. The co-cured subsurface enhancements are non-woven carbon nanotube (CNT) sheets, metallic wire mesh, and metallic surface cladding. One dimensional, steady-state, thermal conduction experiments were carried out using a thermocouple array in a well-insulated space between a heat source and a heat sink. Accounting for heat losses and thermal contact resistances, a best-fit curve from an experimental temperature distribution profile is used to calculate thermal conductivities for all composite specimens. Mechanical property degradations due to the added thermal enhancements were measured using in-plane stiffness, flexural strength, and interlaminar shear strength as benchmarks. The thermal conductivity of the CNT sheet enhanced composite improved by 18% with an insignificant decrease in mechanical properties.
Tribological Study of Magnesium Alloys for Implant Applications
Authors: McGhee Paul , Pai Devdas , Yarmolenko Sergey , Xu Zhigang , Neralla Sudheer , Chen Yongjun
Published: June 2016

Magnesium and its alloys have been found to potential candidates for biodegradable implant applications. However, magnesium and its alloys are broadly known to have poor tribological properties, but detailed specifics on wear performance are scarce. This research investigates the tribological characteristics on Mg-Zn-Ca-RE alloys and pure magnesium under as-cast and extruded conditions. Pure magnesium and Mg-Zn-Ca-RE alloys were hot extruded at 350°C and 400°C. Magnesium and Mg-Zn-Ca-Re alloy were also cast at 350°C and heat treated at 510°C. Directional wear properties were investigated using a CETR-UMT 2 microtribometer under unlubricated conditions in a reciprocating configuration for 120 cycles, with normal loads ranging from 0.5N–2.5N. Wear tests were conducted in directions: cross-sectional, longitudinal (along the extrusion direction) and transverse direction (perpendicular to the extrusion direction). Wear properties and friction properties were analyzed using a microtribometer, a mechanical stylus profiler, and microindentation. Surface morphology and microstructure were characterized using optical microscopy, scanning electron microscopy, and optical profilometry. The results show a lower wear rate in the transverse and cross-sectional direction compared to the longitudinal direction.
Physical and Structural Properties of Pulsed-DC Sputtered Al2O3, MgO and ZrO2 Coating for Mg Corrosion Control
Authors: Kotoka Ruben , Fialkova Svitlana , Yarmolenko Sergey , Pai Devdas , Sankar Jag
Published: June 2016

Magnesium has attracted a lot of attention over the last few decades, due to its light weight and potential use as biomaterial. However, the poor corrosion resistance of magnesium restricts its practical use for application where exposure to aggressive aqueous media is unavoidable. This paper describes the growth, characterization and corrosion analyses of Al2O3, MgO and ZrO2 coatings for slowing down the degradation of Mg. Different thicknesses of Al2O3, MgO and ZrO2 were deposited on pure magnesium (99.95%) substrates using pulsed-DC magnetron sputtering process. The phase composition and microstructure analyses were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The corrosion protection behavior of the Al2O3, MgO and ZrO2 coated samples were evaluated using electrochemical measurements as such open-circuit potential, potentiodynamics and EIS. The corrosion test were performed in 0.9 wt% saline solution. The results showed that the Al2O3-coated Mg alloy exhibit a much superior stability and lower corrosion rate. The surface analyses of the corroded samples showed that the coating improved the corrosion resistance, whereas the bare Mg suffered severe localized corrosion. Adhesion assay was performed on the Al2O3, MgO and ZrO2 coatings to determine their biocompatibility. The results showed significant cell attachment to the coating compare to the control (bare glass).
Investigation of a 27-Fatality Road Crash Involving a Double Road Tanker Impacting the Central Barrier
Authors: Navarrete José Antonio Romero , Guzmán Alejandro A. Lozano , Navarrete Israel Aguilera
Published: June 2016

In a context in which a succession of crashes involving double combination vehicles has occurred in Mexico during 2012 and 2013, a catastrophic accident occurred on May 7, 2013, burning-killing 27 people whose homes were located adjacent to the road. In this case, the double combination carried Liquefied Petroleum Gas (LPG) in both containers, the second of which exploded as a consequence of its decoupling from the vehicle and roll over. The impact of the tractor against the median barrier due to an excessive evasive maneuver sparked a first conflagration due to a fuel leakage, which supplied the heat for the warming and subsequent explosion of the rolled-over container. The cabin of the tractor-semitrailer caught fire but the driver was able to move the vehicle 500 meters away from the crash spot. The analysis suggests that several characteristics of the vehicle and infrastructure could have mitigated or prevented the catastrophic consequences of this event, along with an appropriate response from the emergency response agencies. In particular, both, a B-train vehicular configuration and a vertical barrier could have prevented the occurrence of the fatal roll over.
Study of Cost of Quality Behavior in Manufacturing Supply Chain Based on the Quality Maturity Status
Authors: Ayati Ehsan , Schiffauerova Andrea
Published: June 2016

Measuring Cost of Quality (COQ) seems to be a critical factor for organizations in order to keep or grow their market share. However, until now the COQ has been measured almost exclusively only internally, i.e. within a company, while the role of a supply chain in delivering quality product to end users has been ignored. In this paper we argue that all the entities within supply chain affect the quality of a product or a service and their quality related activities should thus be inevitably considered. The objective of this research is to develop a mathematical model to estimate COQ as key performance measurement within manufacturing supply chain while considering quality Excellency status. Using classic PAF (Prevention-Appraisal-Failure) model classification to develop mathematical model and its integration with significant variables in supply chain entities are the key methodology in this work. Perceived quality is assumed as an appropriate definition of quality in manufacturing supply chain. Moreover, proposed model is examined against real time quality cost data of manufacturing supply chain in two intervals, first at quality immaturity period and then at quality maturity period. Statistical tools are used to validate the model and compare its behaviour in the two intervals. The results are then analyzed and discussed, and possible future works are presented.
Static Analysis of Advanced Composites for the Optimal Design of an Experimental Lightweight Solar Vehicle Suspension System
Authors: Hurter Warren S. , Janse Van Rensburg Nickey , Madyira Daniel M. , Oosthuizen Gert Adriaan
Published: June 2016

To create an energy efficient vehicle there are a number of aspects that need to be optimized, namely; the drive train of the vehicle and energy source, aerodynamics and weight. Focusing on weight reduction, while still maintaining the desired performance and structural strength, many manufacturers are turning to advanced composites due to their superior strength to weight characteristics. Solar car racing provides a research platform that drives this innovation through technology development and efficiency. A lightweight vehicle suspension system design is being presented, together with an introduction into future testing. A suspension system is made up of a number of critical components which are dynamically loaded during standard operation due to undulating forces imposed by the road surface. Unidirectional cross-wound carbon fiber tubing is used for suspension and steering arms. The tubing is interfaced with small steel inserts and pivoting arm tie rod ends. Concerns within the design are the adhesive bonding of the carbon tubing to the steel inserts, and what type of tensile loading the interface can withstand. Due to forces imposed on the system during cornering and shock loading the components are required to withstand a minimum of 1.2 times the weight of the overall vehicle, i.e. 258 kg. Tensile test results show that the mechanical properties of the adhesive joints rely somewhat on the surface characteristics and bond preparation. The target load of 258 kg was successfully obtained under static loading for two types of sample sets. The first based on the standard for describing the lap shear strength of adhesively bonded carbon fiber to aluminum, and the second based on the working component itself.
Fatigue and Fretting of Mixed Metal Self-Piercing Riveted Joint
Authors: Huang Li , Lasecki John , Guo Haiding , Su Xuming
Published: June 2016

The fatigue behavior of self-piercing riveting (SPR) joint, joining aluminum alloy 6111T4 and steel HSLA340 sheets with lapshear geometry was investigated in this paper. Sheet crack was the dominant failure mode, while unexpected rivet shank failure tended to occur under high loading level. Fretting wear was observed at interface of aluminum and steel layers, as well as at rivet and sheets under sinusoidal cyclic tension-tension loading. An energy dispersive X-ray (EDX) analysis of fretting debris revealed the presence of oxide of aluminum and zinc. Fretting was shown to be critical as crack initiation spot. In sheet failure mode, micro cracks were found to initiate at early stage, and crack initiation life was much shorter than crack growth life.
Paper of note in
Science Translational Medicine
Authors: Ferrarelli Leslie K.
Published: June 2016

This week’s article describes how gene variant analysis might inform drug development.
Papers of note in
Science
Authors: VanHook Annalisa M.
Published: June 2016

This week’s articles highlight how components from dying cells can shape the immune response and show that a mixture of small molecules can reprogram human fibroblasts into cardiomyocytes.
Relationship between Fosfomycin Exposure and Amplification of Escherichia coli Subpopulations with Reduced Susceptibility in a Hollow-Fiber Infection Model
Authors: VanScoy Brian , McCauley Jennifer , Bhavnani Sujata M. , Ellis-Grosse Evelyn J. , Ambrose Paul G.
Published: June 2016

Understanding the relationship between antibiotic exposure and amplification of bacterial subpopulations with reduced drug susceptibility over time is important for evaluating the adequacy of dosing regimens. We utilized a hollow-fiber infection model to identify the fosfomycin intravenous dosing regimens that prevented the amplification of
Escherichia coli
bacterial subpopulations with reduced fosfomycin susceptibility. The challenge isolate was
E. coli
ATCC 25922 (agar MIC with glucose-6-phosphate, 1 mg/liter; agar MIC without glucose-6-phosphate, 32 mg/liter). The fosfomycin dosing regimens studied were 1 to 12 g every 8 h for 10 days to approximate that planned for clinical use. The studies included a no-treatment control regimen. Two bacterial subpopulations were identified, one with reduced susceptibility with agar MIC values ranging from 32 to 128 mg/liter and the other resistant with agar MIC values of 256 to >1,024 mg/liter on plates containing 5× and 256× the baseline MIC value, respectively. An inverted-U-shaped function best described the relationship between the amplification of the two bacterial subpopulations and drug exposure. The lowest fosfomycin dosing regimen that did not amplify a bacterial subpopulation with reduced susceptibility was 4 g administered every 8 h. Nearly immediate amplification of bacterial subpopulations with reduced susceptibility was observed with fosfomycin dosing regimens consisting of 1 to 2 g every 8 h. These data will be useful to support the selection of fosfomycin dosing regimens that minimize the potential for on-therapy amplification of bacterial subpopulations with reduced susceptibility.
In Vitro
Characterization of Human Cytomegalovirus-Targeting Therapeutic Monoclonal Antibodies LJP538 and LJP539
Authors: Patel Hetalkumar D. , Nikitin Pavel , Gesner Thomas , Lin James J. , Barkan David T. , Ciferri Claudio , Carfi Andrea , Akbarnejad Yazdi Tahmineh , Skewes-Cox Peter , Wiedmann Brigitte , Jarousse Nadine , Zhong Weidong , Feire Adam , Hebner Christy M.
Published: June 2016

Human cytomegalovirus (HCMV) infection is usually benign in healthy individuals but can cause life-threatening disease in those with compromised immune systems. Approved drugs available to treat HCMV disease, including ganciclovir, cidofovir, and foscarnet, have significant toxicities that limit their use in certain patient populations. LJP538 and LJP539 are human monoclonal antibodies that are being evaluated as immunoglobulin therapeutics. The antibodies target glycoproteins gB and the gH/gL/UL128/UL130/UL131a pentameric complex, respectively. Here we present an
in vitro
characterization of these antibodies. We show that LJP538 and LJP539 are more potent than a marketed immunoglobulin at inhibiting HCMV infection of various cell lines relevant to pathogenesis. We find that LJP538 and LJP539 are active against a panel of clinical isolates
in vitro
and demonstrate minor-to-moderate synergy in combination. Passage of HCMV in the presence of LJP538 or LJP539 alone resulted in resistance-associated mutations that mapped to the target genes. However, no loss of susceptibility to the combination of antibodies was observed for >400 days in culture. Finally, the binding regions of LJP538 and LJP539 are conserved among clinical isolates. Taken together, these data support the use of LJP538 and LJP539 in combination for clinical trials in HCMV patients.
Serum Albumin and Ca
2+
Are Natural Competence Inducers in the Human Pathogen Acinetobacter baumannii
Authors: Traglia German Matias , Quinn Brettni , Schramm Sareda T. J. , Soler-Bistue Alfonso , Ramirez Maria Soledad
Published: June 2016

The increasing frequency of bacteria showing antimicrobial resistance (AMR) raises the menace of entering into a postantibiotic era. Horizontal gene transfer (HGT) is one of the prime reasons for AMR acquisition.
Acinetobacter baumannii
is a nosocomial pathogen with outstanding abilities to survive in the hospital environment and to acquire resistance determinants. Its capacity to incorporate exogenous DNA is a major source of AMR genes; however, few studies have addressed this subject. The transformation machinery as well as the factors that induce natural competence in
A. baumannii
are unknown. In this study, we demonstrate that naturally competent strain A118 increases its natural transformation frequency upon the addition of Ca
2+
or albumin. We show that
comEA
and
pilQ
are involved in this process since their expression levels are increased upon the addition of these compounds. An unspecific protein, like casein, does not reproduce this effect, showing that albumin's effect is specific. Our work describes the first specific inducers of natural competence in
A. baumannii
. Overall, our results suggest that the main protein in blood enhances HGT in
A. baumannii
, contributing to the increase of AMR in this threatening human pathogen.
Antimalarial Benzoxaboroles Target Plasmodium falciparum Leucyl-tRNA Synthetase
Authors: Sonoiki Ebere , Palencia Andres , Guo Denghui , Ahyong Vida , Dong Chen , Li Xianfeng , Hernandez Vincent S. , Zhang Yong-Kang , Choi Wai , Gut Jiri , Legac Jennifer , Cooper Roland , Alley M. R. K. , Freund Yvonne R. , DeRisi Joseph , Cusack Stephen , Rosenthal Philip J.
Published: June 2016

There is a need for new antimalarials, ideally with novel mechanisms of action. Benzoxaboroles have been shown to be active against bacteria, fungi, and trypanosomes. Therefore, we investigated the antimalarial activity and mechanism of action of 3-aminomethyl benzoxaboroles against
Plasmodium falciparum
. Two 3-aminomethyl compounds, AN6426 and AN8432, demonstrated good potency against cultured multidrug-resistant (W2 strain)
P. falciparum
(50% inhibitory concentration [IC
50
] of 310 nM and 490 nM, respectively) and efficacy against murine
Plasmodium berghei
infection when administered orally once daily for 4 days (90% effective dose [ED
90
], 7.4 and 16.2 mg/kg of body weight, respectively). To characterize mechanisms of action, we selected parasites with decreased drug sensitivity by culturing with stepwise increases in concentration of AN6426. Resistant clones were characterized by whole-genome sequencing. Three generations of resistant parasites had polymorphisms in the predicted editing domain of the gene encoding a
P. falciparum
leucyl-tRNA synthetase (LeuRS; PF3D7_0622800) and in another gene (PF3D7_1218100), which encodes a protein of unknown function. Solution of the structure of the
P. falciparum
LeuRS editing domain suggested key roles for mutated residues in LeuRS editing. Short incubations with AN6426 and AN8432, unlike artemisinin, caused dose-dependent inhibition of [
14
C]leucine incorporation by cultured wild-type, but not resistant, parasites. The growth of resistant, but not wild-type, parasites was impaired in the presence of the unnatural amino acid norvaline, consistent with a loss of LeuRS editing activity in resistant parasites. In summary, the benzoxaboroles AN6426 and AN8432 offer effective antimalarial activity and act, at least in part, against a novel target, the editing domain of
P. falciparum
LeuRS.
EseE of Edwardsiella tarda Augments Secretion of Translocon Protein EseC and Expression of the
escC
-
eseE
Operon
Authors: Yi Jia , Xiao Shui Bing , Zeng Zhi Xiong , Lu Jin Fang , Liu Lu Yi , Laghari Zubair Ahmed , Nie Pin , Yu Hong Bing , Xie Hai Xia
Published: June 2016

Edwardsiella tarda
is an important Gram-negative pathogen that employs a type III secretion system (T3SS) to deliver effectors into host cells to facilitate bacterial survival and replication. These effectors are translocated into host cells through a translocon complex composed of three secreted proteins, namely, EseB, EseC, and EseD. The secretion of EseB and EseD requires a chaperone protein called EscC, whereas the secretion of EseC requires the chaperone EscA. In this study, we identified a novel protein (EseE) that also regulates the secretion of EseC. An
eseE
deletion mutant secreted much less EseC into supernatants, accompanied by increased EseC levels within bacterial cells. We also demonstrated that EseE interacted directly with EseC in a pulldown assay. Interestingly, EseC, EseE, and EscA were able to form a ternary complex, as revealed by pulldown and gel filtration assays. Of particular importance, the deletion of
eseE
resulted in decreased levels of EseB and EseD proteins in both the bacterial pellet and supernatant fraction. Furthermore, real-time PCR assays showed that EseE positively regulated the transcription of the translocon operon
escC
-
eseE
, comprising
escC
,
eseB
,
escA
,
eseC
,
eseD
, and
eseE
. These effects of EseE on the translocon components/operon appeared to have a functional consequence, since the Δ
eseE
strain was outcompeted by wild-type
E. tarda
in a mixed infection in blue gourami fish. Collectively, our results demonstrate that EseE not only functions as a chaperone for EseC but also acts as a positive regulator controlling the expression of the translocon operon
escC-eseE
, thus contributing to the pathogenesis of
E. tarda
in fish.
Interleukin-17 Pathophysiology and Therapeutic Intervention in Cystic Fibrosis Lung Infection and Inflammation
Authors: Hsu Daniel , Taylor Patricia , Fletcher Dave , van Heeckeren Rolf , Eastman Jean , van Heeckeren Anna , Davis Pamela , Chmiel James F. , Pearlman Eric , Bonfield Tracey L.
Published: June 2016

Cystic fibrosis (CF) is characterized by an excessive neutrophilic inflammatory response within the airway as a result of defective cystic fibrosis transmembrane receptor (CFTR) expression and function. Interleukin-17A induces airway neutrophilia and mucin production associated with
Pseudomonas aeruginosa
colonization, which is associated with the pathophysiology of cystic fibrosis. The objectives of this study were to use the preclinical murine model of cystic fibrosis lung infection and inflammation to investigate the role of IL-17 in CF lung pathophysiology and explore therapeutic intervention with a focus on IL-17.
Cftr
-deficient mice (CF mice) and wild-type mice (WT mice) infected with
P. aeruginosa
had robust IL-17 production early in the infection associated with a persistent elevated inflammatory response. Intratracheal administration of IL-17 provoked a neutrophilic response in the airways of WT and CF animals which was similar to that observed with
P. aeruginosa
infection. The neutralization of IL-17 prior to infection significantly improved the outcomes in the CF mice, suggesting that IL-17 may be a therapeutic target. We demonstrate in this report that the pathophysiological contribution of IL-17 may be due to the induction of chemokines from the epithelium which is augmented by a deficiency of
Cftr
and ongoing inflammation. These studies demonstrate the
in vivo
contribution of IL-17 in cystic fibrosis lung disease and the therapeutic validity of attenuating IL-17 activity in cystic fibrosis.
Investigating the Relatedness of Enteroinvasive Escherichia coli to Other E. coli and Shigella Isolates by Using Comparative Genomics
Authors: Hazen Tracy H. , Leonard Susan R. , Lampel Keith A. , Lacher David W. , Maurelli Anthony T. , Rasko David A.
Published: June 2016

Enteroinvasive
Escherichia coli
(EIEC) is a unique pathovar that has a pathogenic mechanism nearly indistinguishable from that of
Shigella
species. In contrast to isolates of the four
Shigella
species, which are widespread and can be frequent causes of human illness, EIEC causes far fewer reported illnesses each year. In this study, we analyzed the genome sequences of 20 EIEC isolates, including 14 first described in this study. Phylogenomic analysis of the EIEC genomes demonstrated that 17 of the isolates are present in three distinct lineages that contained only EIEC genomes, compared to reference genomes from each of the
E. coli
pathovars and
Shigella
species. Comparative genomic analysis identified genes that were unique to each of the three identified EIEC lineages. While many of the EIEC lineage-specific genes have unknown functions, those with predicted functions included a colicin and putative proteins involved in transcriptional regulation or carbohydrate metabolism.
In silico
detection of the
Shigella
virulence plasmid (pINV), which is essential for the invasion of host cells, demonstrated that a form of pINV was present in nearly all EIEC genomes, but the Mxi-Spa-Ipa region of the plasmid that encodes the invasion-associated proteins was absent from several of the EIEC isolates. The comparative genomic findings in this study support the hypothesis that multiple EIEC lineages have evolved independently from multiple distinct lineages of
E. coli
via the acquisition of the
Shigella
virulence plasmid and, in some cases, the
Shigella
pathogenicity islands.
HtrA, a Temperature- and Stationary Phase-Activated Protease Involved in Maturation of a Key Microbial Virulence Determinant, Facilitates Borrelia burgdorferi Infection in Mammalian Hosts
Authors: Ye Meiping , Sharma Kavita , Thakur Meghna , Smith Alexis A. , Buyuktanir Ozlem , Xiang Xuwu , Yang Xiuli , Promnares Kamoltip , Lou Yongliang , Yang X. Frank , Pal Utpal
Published: June 2016

High-temperature requirement protease A (HtrA) represents a family of serine proteases that play important roles in microbial biology. Unlike the genomes of most organisms, that of
Borrelia burgdorferi
notably encodes a single HtrA gene product, termed BbHtrA. Previous studies identified a few substrates of BbHtrA; however, their physiological relevance could not be ascertained, as targeted deletion of the gene has not been successful. Here we show that Bb
htrA
transcripts are induced during spirochete growth either in the stationary phase or at elevated temperature. Successful generation of a Bb
htrA
deletion mutant and restoration by genetic complementation suggest a nonessential role for this protease in microbial viability; however, its remarkable growth, morphological, and structural defects during cultivation at 37°C confirm a high-temperature requirement for protease activation and function. The Bb
htrA
-deficient spirochetes were unable to establish infection of mice, as evidenced by assessment of culture, PCR, and serology. We show that transcript abundance as well as proteolytic processing of a borrelial protein required for cell fission and infectivity, BB0323, is impaired in Bb
htrA
mutants grown at 37°C, which likely contributed to their inability to survive in a mammalian host. Together, these results demonstrate the physiological relevance of a unique temperature-regulated borrelial protease, BbHtrA, which further enlightens our knowledge of intriguing aspects of spirochete biology and infectivity.
Genetic and Transcriptional Analyses of the Flagellar Gene Cluster in Actinoplanes missouriensis
Authors: Jang Moon-Sun , Mouri Yoshihiro , Uchida Kaoru , Aizawa Shin-Ichi , Hayakawa Masayuki , Fujita Nobuyuki , Tezuka Takeaki , Ohnishi Yasuo
Published: June 2016

Actinoplanes missouriensis
, a Gram-positive and soil-inhabiting bacterium, is a member of the rare actinomycetes. The filamentous cells produce sporangia, which contain hundreds of flagellated spores that can swim rapidly for a short period of time until they find niches for germination. These swimming cells are called zoospores, and the mechanism of this unique temporal flagellation has not been elucidated. Here, we report all of the flagellar genes in the bacterial genome and their expected function and contribution for flagellar morphogenesis. We identified a large flagellar gene cluster composed of 33 genes that encode the majority of proteins essential for assembling the functional flagella of Gram-positive bacteria. One noted exception to the cluster was the location of the
fliQ
gene, which was separated from the cluster. We examined the involvement of four genes in flagellar biosynthesis by gene disruption,
fliQ
,
fliC
,
fliK
, and
lytA
. Furthermore, we performed a transcriptional analysis of the flagellar genes using RNA samples prepared from
A. missouriensis
grown on a sporangium-producing agar medium for 1, 3, 6, and 40 days. We demonstrated that the transcription of the flagellar genes was activated in conjunction with sporangium formation. Eleven transcriptional start points of the flagellar genes were determined using the rapid amplification of cDNA 5′ ends (RACE) procedure, which revealed the highly conserved promoter sequence CTCA(N
15–17
)GCCGAA. This result suggests that a sigma factor is responsible for the transcription of all flagellar genes and that the flagellar structure assembles simultaneously.

IMPORTANCE
The biology of a zoospore is very interesting from the viewpoint of morphogenesis, survival strategy, and evolution. Here, we analyzed flagellar genes in
A. missouriensis
, which produces sporangia containing hundreds of flagellated spores each. Zoospores released from the sporangia swim for a short time before germination occurs. We identified a large flagellar gene cluster and an orphan flagellar gene (
fliQ
). These findings indicate that the zoospore flagellar components are typical of Gram-positive bacteria. However, the transcriptional analysis revealed that all flagellar genes are transcribed simultaneously during sporangium formation, a pattern differing from the orderly, regulated expression of flagellar genes in other bacteria, such as
Salmonella
and
Escherichia coli
. These results suggest a novel regulatory mechanism for flagellar formation in
A. missouriensis
.
Vitamin A toxicity presenting as bone pain
Authors: Baineni Revanth , Gulati Reena , Delhi CG Kumar
Published: June 2016

A 4-year-old boy presented with severe bone pains, refusal to walk, diffuse bony swelling of forelimbs, skin changes and abdominal pain, with symptoms evolving over 6 weeks. Blood screening tests were normal except for raised aspartate aminotransferase (AST). Radiographs revealed thickened periosteum, widening of the diaphyses of long bones and lifted periosteum in mid-shaft of ulnae and right femur. Skeletal scintigraphy showed a high uptake of radionuclide at clinically affected and unaffected sites, suggestive of multifocal osteoblastic skeletal lesions. After repeated enquiries, his parents admitted to giving him massive doses of preformed vitamin A for over 3 months as ‘health tablets’. Surprisingly, he did not have overt liver disease typically found with much smaller doses, although the dermal changes and musculoskeletal pathology were florid. He made a full clinical recovery within 2 months of cessation of vitamin A.
Electronic nicotine delivery system landscape in licensed tobacco retailers: results of a county-level survey in Oklahoma
Authors: Brame L S , Mowls D S , Damphousse K E , Beebe L A
Published: June 2016

Objectives

Electronic nicotine delivery systems (ENDS) have recently emerged as a component of the tobacco retail environment. The aims of this study were to describe the availability, types of ENDS and placement of ENDS relative to traditional tobacco products at franchised licensed tobacco retailers and non-franchised licensed tobacco retailers.

Design

Observational study.

Setting

Franchised and non-franchised tobacco retailers in Cleveland County, Oklahoma, USA.

Primary and secondary outcome measures

The number of stores selling ENDS, the variability in brands of ENDS sold, the location of the ENDS within the retailers, the quantity of ENDS sold compared with traditional tobacco products, and the presence of outdoor signage.

Results

Data from 57 randomly sampled tobacco retailers were used to describe the presence of ENDS at independent non-franchised and franchised tobacco retailers. The overwhelming majority (90%) of licensed tobacco retailers sold ENDS, and differences were observed between franchised and non-franchised stores. 45 of the 51 retailers (88%) selling ENDS had them placed at the point of sale. 2 of the 21 franchised retailers (9.5%) had ENDS placed at ≤3½ feet above floor level compared to none of the 30 non-franchised retailers (0%).

Conclusions

This small study is the first to characterise ENDS within the tobacco retail environment in a county in Oklahoma, USA. The results from this study demonstrate the complexity of the tobacco retail landscape and generate questions for future studies regarding the incorporation and placement of ENDS in tobacco retail environments.
Longitudinal trends in use and costs of targeted therapies for common cancers in Taiwan: a retrospective observational study
Authors: Hsu Jason C , Lu Christine Y
Published: June 2016

Objectives

Some targeted therapies have improved survival and overall quality of cancer care generally, but these increasingly expensive medicines have led to increases in pharmaceutical expenditure. This study examined trends in use and expenditures of antineoplastic agents in Taiwan, and estimated market shares by prescription volume and costs of targeted therapies over time. We also determined which cancer types accounted for the highest use of targeted therapies.

Design

This is a retrospective observational study focusing on the utilisation of targeted therapies for treatment of cancer.

Setting

The monthly claims data for antineoplastic agents were retrieved from Taiwan's National Health Insurance Research Database (2009–2012).

Main outcome measures

We calculated market shares by prescription volume and costs for each class of antineoplastic agent by cancer type. Using a time series design with Autoregressive Integrated Moving Average (ARIMA) models, we estimated trends in use and costs of targeted therapies.

Results

Among all antineoplastic agents, use of targeted therapies grew from 6.24% in 2009 to 12.29% in 2012, but their costs rose from 26.16% to 41.57% in that time. Monoclonal antibodies and protein kinase inhibitors contributed the most (respectively, 23.84% and 16.12% of costs for antineoplastic agents in 2012). During 2009–2012, lung (44.64% of use; 28.26% of costs), female breast (16.49% of use; 27.18% of costs) and colorectal (12.11% of use; 13.16% of costs) cancers accounted for the highest use of targeted therapies.

Conclusions

In Taiwan, targeted therapies are increasingly used for different cancers, representing a substantial economic burden. It is important to establish mechanisms to monitor their use and outcomes.
Improving the quality of handover in a liaison psychiatry team
Authors: Brook Jennifer , Amaro Calcia Marilia
Published: June 2016

Handover is a high risk point for errors in clinical care, in many cases leading to adverse events or near misses. The timely transfer of accurate and useful information between professionals is vital to ensure quality and safety, and to ensure the transfer of accountability for care.

In this project standards were developed for quality handover between doctors in a liaison psychiatry department. The aim of these were to ensure adequate identification of patients, clear communication of tasks to be completed and relevant risk issues, as well as a guide to the priority of jobs. We measured compliance with these standards for all patients documented in the handover book during three week periods in 2013, 2014 (following delivery of education and guidance on handover to all doctors), and finally in 2015 after implementation of a proforma for handover.

Handover documentation prior to the implementation of standards was of poor quality with significant absences of information. Key information to identify patients was frequently absent, for example hospital number was only recorded in 1% of cases. Only 81% of entries included the reason for the patient's referral, and 27% made no mention of the outstanding tasks for completion. Despite guidance and education of all doctors regarding the standards, there was no consistent improvement in compliance. It was particularly concerning that risk issues were only mentioned in 18% of cases, even when assessed immediately after education was given. Following introduction of the proforma compliance increased with overall completeness of handover improving from 40% to 71%.

Without guidelines handover between shifts is of a poor quality, and often lacks key information to allow colleagues to identify patients and prioritise need. Education of those performing these handovers did not produce any benefits, either immediately following its delivery or in longer term follow up. The implementation of a template to aid clinicians in recording this data did produce improvements and received positive feedback from doctors.
A change of culture: reducing blood culture contamination rates in an Emergency Department
Authors: Bentley James , Thakore Shobhan , Muir L , Baird Alastair , Lee Jennifer
Published: June 2016

Blood cultures are an important investigation to help tailor effective management for patients with severe sepsis. Frequent contaminated samples increase laboratory workload and can delay or cause incorrect changes to patient management. This can prolong patient hospitalisation, increase the risk of harm and increase cost to health boards. Current guidelines advocate a contamination rate of 2–3%. From January 2013 to November 2014 inclusive, the contamination rate was 4.74% in our Emergency Department, responsible for initial management and investigation of over 40 cases of sepsis per month. A Quality Improvement team was created to try to reduce contamination rates to the recommended target.

An initial baseline survey of local staff showed good understanding of when to obtain a blood culture but there was variability in the methods and equipment used. A project was then conducted which focused on rationalising and standardising equipment and technique for blood culture sampling along with staff education to support this change. A simple department target of 30 days free from a contaminated blood culture was created which, if achieved, would ensure a contamination rate of less than 3%. This was supported by ongoing surveillance of contamination rates and investigation of contaminated sample cases. We were able to then identify high risk patients and factors which increased the chance of blood culture contamination. This allowed us to formulate solutions to help reduce the risks of contamination. Department achievements and learning points to help prevent further contamination were fed back positively to all staff. This project operated for 12-months and successfully reduced local contamination rates to 2.0%.
Improving admission medication reconciliation compliance using the electronic tool in admitted medical patients
Authors: Taha Haytham , abdulhay dana , Luqman Neama , Ellahham Samer
Published: June 2016

Sheikh Khalifa Medical City (SKMC) in Abu Dhabi is the main tertiary care referral hospital in the United Arab Emirates (UAE) with 560 bed capacity that is fully occupied most of the time.

SKMC senior management has made a commitment to make quality and patient safety a top priority. Our governing body Abu Dhabi Health Services Company has identified medication reconciliation as a critical patient safety measure and key performance indicator (KPI). The medication reconciliation electronic form a computerized decision support tool was introduced to improve medication reconciliation compliance on transition of care at admission, transfer and discharge of patients both in the inpatient and outpatient settings. In order to improve medication reconciliation compliance a multidisciplinary task force team was formed and led this quality improvement project. The purpose of this publication is to indicate the quality improvement interventions implemented to enhance compliance with admission medication reconciliation and the outcomes of those interventions.

We chose to conduct the pilot study in general medicine as it is the busiest department in the hospital, with an average of 390 patients admitted per month during the study period. The study period was from April 2014 till October 2015 and a total of 8576 patients were evaluated. The lessons learned were disseminated throughout the hospital. Our aim was to improve admission medication reconciliation compliance using the electronic form in order to ensure patient safety and reduce preventable harm in terms of medication errors. Admission medication reconciliation compliance improved in general medicine from 40% to above 85%, and this improvement was sustained for the last four months of the study period.
Improving the management of iron deficiency in ambulatory heart failure patients
Authors: Hayward Carl , Patel Hitesh , Allen Chris , Vazir Ali
Published: June 2016

Based on clinical trial data patients with heart failure (HF) and evidence of iron deficiency should be offered intravenous (iv) iron with the aim of improving exercise capacity and symptoms. Baseline measurement in outpatient HF clinics demonstrated that only 50% of patients who may be eligible for iv iron were investigated with iron studies. Our aim was to make sure that 90% of the patients attending our heart failure clinics who were symptomatic and had an ejection fraction (EF) ≤45% should have their iron studies checked within the last six months.

In an effort to increase the proportion of suitable patients in whom iron studies are requested, we carried out three plan-do-study-act (PDSA) cycles each with a different intervention. These interventions included a presentation of the clinical trial evidence at a HF multidisciplinary meeting, email reminders prior to clinic and stickers in the patient notes (repeated twice). The effect of each intervention was measured with the outcome being the proportion of eligible patients in whom iron studies were documented within the previous 6 months. The interventions increased the number of suitable patients who had iron studies checked, to as high as 100%, however this effect was not sustained. Root cause analysis revealed that clinicians were unenthusiastic to continue performing iron studies due to inefficiency in the process of admitting patients and giving them iv iron. For example median in-hospital stay of seven hours for an infusion that is given over 15 minutes.

In an attempt to improve patient and physician satisfaction we piloted an ambulatory outpatient service to deliver iv iron. We demonstrated that this service was feasible and more efficient as less time was required waiting for a bed or spent in hospital and was less costly. In summary we have demonstrated interventions which can increase the identification of patients who would benefit from iv iron and piloted a new time and cost efficient system of administration of iv iron.