bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychological Skills for Injury Prevention and Recovery
Authors: Madrigal Leilani
Published: December 2015

Psychological skills such as goal setting, imagery, relaxation and self-talk have been used in performance enhancement, emotional regulation, and increasing one’s confidence and/or motivation in sport. These skills can also be applied with athletes during recovery from injury in the rehabilitation setting or in preseason meetings for preventing injury. Research on psychological skill use with athletes has shown that such skills have helped reduce negative psychological outcomes, improve coping skills, and reduce reinjury anxiety (Evans & Hardy, 2002; Johnson, 2000; Mankad & Gordon, 2010). Although research has been limited in psychological skill implementation with injured athletes, these skills can be used when working with injured athletes or in the prevention of injury. Injured athletes may use psychological skills such as setting realistic goals in coming back from injury, imagery to facilitate rehabilitation, and relaxation techniques to deal with pain management. In prevention of injury, the focus is on factors that put an individual at-risk for injury. Thus, teaching strategies of goal setting, imagery, relaxation techniques, and attention/focus can be instrumental in preparing athletes for a healthy season.
Athletic Trainer-Athlete Communication and Injury Reporting
Authors: Stadden Stephanie A.
Published: December 2015

Through the progression of athletic training education, there has been an increased emphasis on psychosocial aspects related to the field as is evident in the 2011 Athletic Training Education Competencies. The ability to effectively communicate has been identified as an important characteristic for athletic trainers in providing quality care to patients (Raab, Wolfe, Gould, Piland, 2011). Athletic trainers must be able to communicate effectively not only with patients, but also physicians, parents, coaches, and peers. Although research examining effective communication in athletic training is limited, the session will examine existing research performed addressing communication in athletic training and other healthcare professions, such as medicine and nursing. In addition, the session will discuss research linking the athletic trainer-patient relationship and injury reporting tendencies along with practical application of the research to assist the athletic trainer in further development of their professional relationships.
Imidazopyridazine Inhibitors of Plasmodium falciparum Calcium-Dependent Protein Kinase 1 Also Target Cyclic GMP-Dependent Protein Kinase and Heat Shock Protein 90 To Kill the Parasite at Different Stages of Intracellular Development
Authors: Green Judith L. , Moon Robert W. , Whalley David , Bowyer Paul W. , Wallace Claire , Rochani Ankit , Nageshan Rishi K. , Howell Steven A. , Grainger Munira , Jones Hayley M. , Ansell Keith H. , Chapman Timothy M. , Taylor Debra L. , Osborne Simon A. , Baker David A. , Tatu Utpal , Holder Anthony A.
Published: December 2015

Imidazopyridazine compounds are potent, ATP-competitive inhibitors of calcium-dependent protein kinase 1 (CDPK1) and of
Plasmodium falciparum
parasite growth
in vitro
. Here, we show that these compounds can be divided into two classes depending on the nature of the aromatic linker between the core and the R2 substituent group. Class 1 compounds have a pyrimidine linker and inhibit parasite growth at late schizogony, whereas class 2 compounds have a nonpyrimidine linker and inhibit growth in the trophozoite stage, indicating different modes of action for the two classes. The compounds also inhibited cyclic GMP (cGMP)-dependent protein kinase (PKG), and their potency against this enzyme was greatly reduced by substitution of the enzyme's gatekeeper residue at the ATP binding site. The effectiveness of the class 1 compounds against a parasite line expressing the modified PKG was also substantially reduced, suggesting that these compounds kill the parasite primarily through inhibition of PKG rather than CDPK1. HSP90 was identified as a binding partner of class 2 compounds, and a representative compound bound to the ATP binding site in the N-terminal domain of HSP90. Reducing the size of the gatekeeper residue of CDPK1 enabled inhibition of the enzyme by bumped kinase inhibitors; however, a parasite line expressing the modified enzyme showed no change in sensitivity to these compounds. Taken together, these findings suggest that CDPK1 may not be a suitable target for further inhibitor development and that the primary mechanism through which the imidazopyridazines kill parasites is by inhibition of PKG or HSP90.
Histone Deacetylase Inhibitors Promote Mitochondrial Reactive Oxygen Species Production and Bacterial Clearance by Human Macrophages
Authors: Ariffin Juliana K. , das Gupta Kaustav , Kapetanovic Ronan , Iyer Abishek , Reid Robert C. , Fairlie David P. , Sweet Matthew J.
Published: December 2015

Broad-spectrum histone deacetylase inhibitors (HDACi) are used clinically as anticancer agents, and more isoform-selective HDACi have been sought to modulate other conditions, including chronic inflammatory diseases. Mouse studies suggest that HDACi downregulate immune responses and may compromise host defense. However, their effects on human macrophage antimicrobial responses are largely unknown. Here, we show that overnight pretreatment of human macrophages with HDACi prior to challenge with
Salmonella enterica
serovar Typhimurium or
Escherichia coli
results in significantly reduced intramacrophage bacterial loads, which likely reflect the fact that this treatment regime impairs phagocytosis. In contrast, cotreatment of human macrophages with HDACi at the time of bacterial challenge did not impair phagocytosis; instead, HDACi cotreatment actually promoted clearance of intracellular
S
. Typhimurium and
E. coli
. Mechanistically, treatment of human macrophages with HDACi at the time of bacterial infection enhanced mitochondrial reactive oxygen species generation by these cells. The capacity of HDACi to promote the clearance of intracellular bacteria from human macrophages was abrogated when cells were pretreated with MitoTracker Red CMXRos, which perturbs mitochondrial function. The HDAC6-selective inhibitor tubastatin A promoted bacterial clearance from human macrophages, whereas the class I HDAC inhibitor MS-275, which inhibits HDAC1 to -3, had no effect on intracellular bacterial loads. These data are consistent with HDAC6 and/or related HDACs constraining mitochondrial reactive oxygen species production from human macrophages during bacterial challenge. Our findings suggest that, whereas long-term HDACi treatment regimes may potentially compromise host defense, selective HDAC inhibitors may have applications in treating acute bacterial infections.
Maduramicin Rapidly Eliminates Malaria Parasites and Potentiates the Gametocytocidal Activity of the Pyrazoleamide PA21A050
Authors: Maron Maxim I. , Magle Crystal T. , Czesny Beata , Turturice Benjamin A. , Huang Ruili , Zheng Wei , Vaidya Akhil B. , Williamson Kim C.
Published: December 2015

New strategies targeting
Plasmodium falciparum
gametocytes, the sexual-stage parasites that are responsible for malaria transmission, are needed to eradicate this disease. Most commonly used antimalarials are ineffective against
P. falciparum
gametocytes, allowing patients to continue to be infectious for over a week after asexual parasite clearance. A recent screen for gametocytocidal compounds demonstrated that the carboxylic polyether ionophore maduramicin is active at low nanomolar concentrations against
P. falciparum
sexual stages. In this study, we showed that maduramicin has an EC
50
(effective concentration that inhibits the signal by 50%) of 14.8 nM against late-stage gametocytes and significantly blocks
in vivo
transmission in a mouse model of malaria transmission. In contrast to other reported gametocytocidal agents, maduramicin acts rapidly
in vitro
, eliminating gametocytes and asexual schizonts in less than 12 h without affecting uninfected red blood cells (RBCs). Ring stage parasites are cleared by 24 h. Within an hour of drug treatment, 40% of the normally crescent-shaped gametocytes round up and become spherical. The number of round gametocytes increases to >60% by 2 h, even before a change in membrane potential as monitored by MitoProbe DiIC1 (5) is detectable. Maduramicin is not preferentially taken up by gametocyte-infected RBCs compared to uninfected RBCs, suggesting that gametocytes are more sensitive to alterations in cation concentration than RBCs. Moreover, the addition of 15.6 nM maduramicin enhanced the gametocytocidal activity of the pyrazoleamide PA21A050, which is a promising new antimalarial candidate associated with an increase in intracellular Na
+
concentration that is proposed to be due to inhibition of PfATP4, a putative Na
+
pump. These results underscore the importance of cation homeostasis in sexual as well as asexual intraerythrocytic-stage
P. falciparum
parasites and the potential of targeting this pathway for drug development.
Potent Antiviral Activities of the Direct-Acting Antivirals ABT-493 and ABT-530 with Three-Day Monotherapy for Hepatitis C Virus Genotype 1 Infection
Authors: Lawitz Eric J. , O'Riordan William D. , Asatryan Armen , Freilich Bradley L. , Box Terry D. , Overcash J. Scott , Lovell Sandra , Ng Teresa I. , Liu Wei , Campbell Andrew , Lin Chih-Wei , Yao Betty , Kort Jens
Published: December 2015

ABT-493 is a hepatitis C virus (HCV) nonstructural (NS) protein 3/4A protease inhibitor, and ABT-530 is an HCV NS5A inhibitor. These direct-acting antivirals (DAAs) demonstrated potent antiviral activity against major HCV genotypes and high barriers to resistance
in vitro
. In this open-label dose-ranging trial, antiviral activity and safety were assessed during 3 days of monotherapy with ABT-493 or ABT-530 in treatment-naive adults with HCV genotype 1 infection, with or without compensated cirrhosis. The presence of baseline resistance-associated variants (RAVs) was also evaluated. The mean maximal decreases in HCV RNA levels from baseline were approximately 4 log
10
IU/ml for all ABT-493 doses ranging from 100 mg to 700 mg and for ABT-530 doses of ≥40 mg. There were no meaningful differences in viral load declines for patients with versus without compensated cirrhosis. Twenty-four (50%) of the baseline samples from patients treated with ABT-493 had RAVs to NS3/4A protease inhibitors. Among 40 patients treated with ABT-530, 6 (15%) carried baseline RAVs to NS5A inhibitors. Viral load declines in patients with single baseline NS5A RAVs were similar to those in patients without RAVs. One patient harbored baseline RAVs at 3 NS5A positions and appeared to have a slightly less robust viral load decline on day 3 of monotherapy. No serious or grade 3 (severe) or higher adverse events and no clinically relevant laboratory abnormalities were observed with either compound. ABT-493 and ABT-530 demonstrated potent antiviral activity and acceptable safety during 3-day monotherapy in patients with HCV genotype 1 infection, with or without compensated cirrhosis. Based on these results, phase II studies assessing the combination of these DAAs for the treatment of chronic HCV infection in patients with or without compensated cirrhosis have been initiated. (This study has been registered at ClinicalTrials.gov under registration no. NCT01995071.)
KPC-Like Carbapenemase-Producing Enterobacteriaceae Colonizing Patients in Europe and Israel
Authors: Baraniak A. , Izdebski R. , Fiett J. , Herda M. , Derde L. P. G. , Bonten M. J. M. , Adler A. , Carmeli Y. , Goossens H. , Hryniewicz W. , Brun-Buisson C. , Gniadkowski M.
Published: December 2015

In a 2008-2011 survey, 17,945 patients in 18 hospital units in Europe and Israel were screened for carriage of
Klebsiella pneumoniae
carbapenemase (KPC)-producing
Enterobacteriaceae
, resulting in identification of 124 positive patients. The isolates were dominated by
Klebsiella pneumoniae
sequence type 258 (ST258) KPC-2 and ST512 KPC-3, mainly from Greece and Italy, respectively, whereas Israeli isolates were of diverse species, clones, and KPC variants. Various
bla
KPC
platforms were observed, among which IncFII
K
-FIB
K
plasmids with
bla
KPC-2/-3
genes in the Tn
4401
a transposon prevailed.
Dissection of Francisella-Host Cell Interactions in Dictyostelium discoideum
Authors: Lampe Elisabeth O. , Brenz Yannick , Herrmann Lydia , Repnik Urska , Griffiths Gareth , Zingmark Carl , Sjöstedt Anders , Winther-Larsen Hanne C. , Hagedorn Monica
Published: December 2015

Francisella
bacteria cause severe disease in both vertebrates and invertebrates and include one of the most infectious human pathogens. Mammalian cell lines have mainly been used to study the mechanisms by which
Francisella
manipulates its host to replicate within a large variety of hosts and cell types, including macrophages. Here, we describe the establishment of a genetically and biochemically tractable infection model: the amoeba
Dictyostelium discoideum
combined with the fish pathogen
Francisella noatunensis
subsp.
noatunensis
. Phagocytosed
F. noatunensis
subsp.
noatunensis
interacts with the endosomal pathway and escapes further phagosomal maturation by translocating into the host cell cytosol.
F. noatunensis
subsp.
noatunensis
lacking IglC, a known virulence determinant required for
Francisella
intracellular replication, follows the normal phagosomal maturation and does not grow in
Dictyostelium
. The attenuation of the
F. noatunensis
subsp.
noatunensis
Δ
iglC
mutant was confirmed in a zebrafish embryo model, where growth of
F. noatunensis
subsp.
noatunensis
Δ
iglC
was restricted. In
Dictyostelium
,
F. noatunensis
subsp.
noatunensis
interacts with the autophagic machinery. The intracellular bacteria colocalize with autophagic markers, and when autophagy is impaired (
Dictyostelium
Δ
atg1
),
F. noatunensis
subsp.
noatunensis
accumulates within
Dictyostelium
cells. Altogether, the
Dictyostelium-F. noatunensis
subsp.
noatunensis
infection model recapitulates the course of infection described in other host systems. The genetic and biochemical tractability of the system allows new approaches to elucidate the dynamic interactions between pathogenic
Francisella
and its host organism.
High Genetic Diversity of Newcastle Disease Virus in Wild and Domestic Birds in Northeastern China from 2013 to 2015 Reveals Potential Epidemic Trends
Authors: Zhang Pingze , Xie Guangyao , Liu Xinxin , Ai Lili , Chen Yanyu , Meng Xin , Bi Yuhai , Chen Jianjun , Sun Yuzhang , Stoeger Tobias , Ding Zhuang , Yin Renfu
Published: December 2015

Newcastle disease (ND), caused by the virulent Newcastle disease virus (NDV), is one of the most important viral diseases of birds globally, but little is currently known regarding enzootic trends of NDV in northeastern China, especially for class I viruses. Thus, we performed a surveillance study for NDV in northeastern China from 2013 to 2015. A total 755 samples from wild and domestic birds in wetlands and live bird markets (LBMs) were collected, and 10 isolates of NDV were identified. Genetic and phylogenetic analyses showed that five isolates from LBMs belong to class I subgenotype 1b, two (one from wild birds and one from LBMs) belong to the vaccine-like class II genotype II, and three (all from wild birds) belong to class II subgenotype Ib. Interestingly, the five class I isolates had epidemiological connections with viruses from southern, eastern, and southeastern China. Our findings, together with recent prevalence trends of class I and virulent class II NDV in China, suggest possible virus transmission between wild and domestic birds and the potential for an NDV epidemic in the future.
Endophytic Bacterium-Triggered Reactive Oxygen Species Directly Increase Oxygenous Sesquiterpenoid Content and Diversity in Atractylodes lancea
Authors: Zhou Jia-Yu , Yuan Jie , Li Xia , Ning Yi-Fan , Dai Chuan-Chao
Published: December 2015

Oxygenous terpenoids are active components of many medicinal plants. However, current studies that have focused on enzymatic oxidation reactions cannot comprehensively clarify the mechanisms of oxygenous terpenoid synthesis and diversity. This study shows that an endophytic bacterium can trigger the generation of reactive oxygen species (ROS) that directly increase oxygenous sesquiterpenoid content and diversity in
Atractylodes lancea
.
A. lancea
is a famous but endangered Chinese medicinal plant that contains abundant oxygenous sesquiterpenoids. Geo-authentic
A. lancea
produces a wider range and a greater abundance of oxygenous sesquiterpenoids than the cultivated herb. Our previous studies have shown the mechanisms behind endophytic promotion of the production of sesquiterpenoid hydrocarbon scaffolds; however, how endophytes promote the formation of oxygenous sesquiterpenoids and their diversity is unclear. After colonization by
Pseudomonas fluorescens
ALEB7B, oxidative burst and oxygenous sesquiterpenoid accumulation in
A. lancea
occur synchronously. Treatment with exogenous hydrogen peroxide (H
2
O
2
) or singlet oxygen induces oxidative burst and promotes oxygenous sesquiterpenoid accumulation
in planta
. Conversely, pretreatment of plantlets with the ROS scavenger ascorbic acid significantly inhibits the oxidative burst and oxygenous sesquiterpenoid accumulation induced by
P. fluorescens
ALEB7B. Further
in vitro
oxidation experiments show that several oxygenous sesquiterpenoids can be obtained from direct oxidation caused by H
2
O
2
or singlet oxygen. In summary, this study demonstrates that endophytic bacterium-triggered ROS can directly oxidize oxygen-free sesquiterpenoids and increase the oxygenous sesquiterpenoid content and diversity in
A. lancea
, providing a novel explanation of the mechanisms of oxygenous terpenoid synthesis
in planta
and an essential complementarity to enzymatic oxidation reactions.
Visualizing Bdellovibrio bacteriovorus by Using the tdTomato Fluorescent Protein
Authors: Mukherjee Somdatta , Brothers Kimberly M. , Shanks Robert M. Q. , Kadouri Daniel E.
Published: December 2015

Bdellovibrio bacteriovorus
is a Gram-negative bacterium that belongs to the delta subgroup of proteobacteria and is characterized by a predatory life cycle. In recent years, work has highlighted the potential use of this predator to control bacteria and biofilms. Traditionally, the reduction in prey cells was used to monitor predation dynamics. In this study, we introduced pMQ414, a plasmid that expresses the tdTomato fluorescent reporter protein, into a host-independent strain and a host-dependent strain of
B. bacteriovorus
109J. The new construct was used to conveniently monitor predator proliferation in real time, in different growth conditions, in the presence of lytic enzymes, and on several prey bacteria, replicating previous studies that used plaque analysis to quantify
B. bacteriovorus
. The new fluorescent plasmid also enabled us to visualize the predator in liquid cultures, in the context of a biofilm, and in association with human epithelial cells.
AraC-Type Regulator Rsp Adapts Staphylococcus aureus Gene Expression to Acute Infection
Authors: Li Tianming , He Lei , Song Yan , Villaruz Amer E. , Joo Hwang-Soo , Liu Qian , Zhu Yuanjun , Wang Yanan , Qin Juanxiu , Otto Michael , Li Min
Published: December 2015

Staphylococcus aureus
is an important human pathogen that can cause two categories of severe infections. Acute infections are characterized by pronounced toxin production, while chronic infections often involve biofilm formation. However, it is poorly understood how
S. aureus
controls the expression of genes associated with acute versus biofilm-associated virulence. We here identified an AraC-type transcriptional regulator, Rsp, that promotes the production of key toxins while repressing major biofilm-associated genes and biofilm formation. Genome-wide transcriptional analysis and modeling of regulatory networks indicated that upregulation of the accessory gene regulator (Agr) and downregulation of the
ica
operon coding for the biofilm exopolysaccharide polysaccharide intercellular adhesin (PIA) were central to the regulatory impact of Rsp on virulence. Notably, the Rsp protein directly bound to the
agrP2
and
icaADBC
promoters, resulting in strongly increased levels of the Agr-controlled toxins phenol-soluble modulins (PSMs) and alpha-toxin and reduced production of PIA. Accordingly, Rsp was essential for the development of bacteremia and skin infection, representing major types of acute
S. aureus
infection. Our findings give important insight into how
S. aureus
adapts the expression of its broad arsenal of virulence genes to promote different types of disease manifestations and identify the Rsp regulator as a potential target for strategies to control acute
S. aureus
infection.
Essential Genome of the Metabolically Versatile Alphaproteobacterium Rhodopseudomonas palustris
Authors: Pechter Kieran B. , Gallagher Larry , Pyles Harley , Manoil Colin S. , Harwood Caroline S.
Published: December 2015

Rhodopseudomonas palustrisis an alphaproteobacterium that has served as a model organism for studies of photophosphorylation, regulation of nitrogen fixation, production of hydrogen as a biofuel, and anaerobic degradation of aromatic compounds. This bacterium is able to transition between anaerobic photoautotrophic growth, anaerobic photoheterotrophic growth, and aerobic heterotrophic growth. As a starting point to explore the genetic basis for the metabolic versatility ofR. palustris, we used transposon mutagenesis and Tn-seq to identify 552 genes as essential for viability in cells growing aerobically on semirich medium. Of these, 323 have essential gene homologs in the alphaproteobacteriumCaulobacter crescentus, and 187 have essential gene homologs inEscherichia coli. There were 24R. palustrisgenes that were essential for viability under aerobic growth conditions that have low sequence identity but are likely to be functionally homologous to essentialE. coligenes. As expected, certain functional categories of essential genes were highly conserved among the three organisms, including translation, ribosome structure and biogenesis, secretion, and lipid metabolism.R. palustriscells divide by budding in which a sessile cell gives rise to a motile swarmer cell. Conserved cell cycle genes required for this developmental process were essential in bothC. crescentusandR. palustris. Our results suggest that despite vast differences in lifestyles, members of the alphaproteobacteria have a common set of essential genes that is specific to this group and distinct from that of gammaproteobacteria likeE. coli.

IMPORTANCEEssential genes in bacteria and other organisms are those absolutely required for viability.Rhodopseudomonas palustrishas served as a model organism for studies of anaerobic aromatic compound degradation, hydrogen gas production, nitrogen fixation, and photosynthesis. We used the technique of Tn-seq to determine the essential genes ofR. palustrisgrown under heterotrophic aerobic conditions. The transposon library generated in this study will be useful for future studies to identifyR. palustrisgenes essential for viability under specialized growth conditions and also for survival under conditions of stress.
Permuting the PGF Signature Motif Blocks both Archaeosortase-Dependent C-Terminal Cleavage and Prenyl Lipid Attachment for the Haloferax volcanii S-Layer Glycoprotein
Authors: Abdul Halim Mohd Farid , Karch Kelly R. , Zhou Yitian , Haft Daniel H. , Garcia Benjamin A. , Pohlschroder Mechthild
Published: December 2015

For years, the S-layer glycoprotein (SLG), the sole component of many archaeal cell walls, was thought to be anchored to the cell surface by a C-terminal transmembrane segment. Recently, however, we demonstrated that the
Haloferax volcanii
SLG C terminus is removed by an archaeosortase (ArtA), a novel peptidase. SLG, which was previously shown to be lipid modified, contains a C-terminal tripartite structure, including a highly conserved proline-glycine-phenylalanine (PGF) motif. Here, we demonstrate that ArtA does not process an SLG variant where the PGF motif is replaced with a PFG motif (
slg

G796F
,
F797G

). Furthermore, using radiolabeling, we show that SLG lipid modification requires the PGF motif and is ArtA dependent, lending confirmation to the use of a novel C-terminal lipid-mediated protein-anchoring mechanism by prokaryotes. Similar to the case for the Δ
artA
strain, the growth, cellular morphology, and cell wall of the
slg

G796F
,
F797G

strain, in which modifications of additional
H. volcanii
ArtA substrates should not be altered, are adversely affected, demonstrating the importance of these posttranslational SLG modifications. Our data suggest that ArtA is either directly or indirectly involved in a novel proteolysis-coupled, covalent lipid-mediated anchoring mechanism. Given that archaeosortase homologs are encoded by a broad range of prokaryotes, it is likely that this anchoring mechanism is widely conserved.

IMPORTANCE
Prokaryotic proteins bound to cell surfaces through intercalation, covalent attachment, or protein-protein interactions play critical roles in essential cellular processes. Unfortunately, the molecular mechanisms that anchor proteins to archaeal cell surfaces remain poorly characterized. Here, using the archaeon
H. volcanii
as a model system, we report the first
in vivo
studies of a novel protein-anchoring pathway involving lipid modification of a peptidase-processed C terminus. Our findings not only yield important insights into poorly understood aspects of archaeal biology but also have important implications for key bacterial species, including those of the human microbiome. Additionally, insights may facilitate industrial applications, given that photosynthetic cyanobacteria encode uncharacterized homologs of this evolutionarily conserved enzyme, or may spur development of unique drug delivery systems.
Metagenomic Evidence for the Presence of Comammox
Nitrospira
-Like Bacteria in a Drinking Water System
Authors: Pinto Ameet J. , Marcus Daniel N. , Ijaz Umer Zeeshan , Bautista-de lose Santos Quyen Melina , Dick Gregory J. , Raskin Lutgarde
Published: December 2015

Nitrification plays an important role in regulating the concentrations of inorganic nitrogen species in a range of environments, from drinking water and wastewater treatment plants to the oceans. Until recently, aerobic nitrification was considered to be a two-step process involving ammonia-oxidizing bacteria or archaea and nitrite-oxidizing bacteria. This process requires close cooperation between these two functional guilds for complete conversion of ammonia to nitrate, without the accumulation of nitrite or other intermediates, such as nitrous oxide, a potent greenhouse gas. The discovery of a single organism with the potential to oxidize both ammonia and nitrite adds a new dimension to the current understanding of aerobic nitrification, while presenting opportunities to rethink nitrogen management in engineered systems.
New quantum MDS-convolutional codes derived from constacyclic codes
Authors: Li Fengwei , Yue Qin
Published: December 2015

In this paper, we utilize a family of Hermitian dual-containing constacyclic codes to construct classical and quantum MDS convolutional codes. Our classical and quantum convolutional codes are optimal in the sense that they attain the classical (quantum) generalized Singleton bound.
Surface modification and electrochemical properties of activated carbons for supercapacitor electrodes
Authors: Yang Dan , Qiu Wenmei , Xu Jingcai , Han Yanbing , Jin Hongxiao , Jin Dingfeng , Peng Xiaoling , Hong Bo , Li Ji , Ge Hongliang , Wang Xinqing
Published: December 2015

Modifications with different acids (HNO3, H2SO4, HCl and HF, respectively) were introduced to treat the activated carbons (ACs) surface. The microstructures and surface chemical properties were discussed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), ASAP, Raman spectra and Fourier transform infrared (FTIR) spectra. The ACs electrode-based supercapacitors were assembled with 6 mol ⋅ L[Formula: see text] KOH electrolyte. The electrochemical properties were studied by galvanostatic charge–discharge and cyclic voltammetry. The results indicated that although the BET surface area of modified ACs decreased, the functional groups were introduced and the ash contents were reduced on the surface of ACs, receiving larger specific capacitance to initial AC. The specific capacitance of ACs modified with HCl, H2SO4, HF and HNO3 increased by 31.4%, 23%, 21% and 11.6%, respectively.
Physical mechanism of beam splitting based on reflective embedded double-layer grating
Authors: Wang Bo , Li Hongtao , Shu Wenhao , Li Wenhua , Chen Li , Lei Liang , Zhou Jinyun
Published: December 2015

It is not easy to achieve high performance for conventional beam splitters, such as high efficiency, good uniformity, polarization-independence, and wide bandwidth. A reflective embedded double-layer grating is described for beam splitting. With optimized grating profiles, the novel beam splitter can diffract both TE and TM polarizations into two orders with high performance. For the easy production, the fabrication tolerance is investigated and given. Most importantly, efficiencies more than 45% can be split into two orders within the wide bandwidth of 1412–1647 nm for TE polarization. The beam splitter based on multilayer coatings is sensitive to the incident angle and wavelength. And the bandwidth needs to be improved for the beam splitter based on simple grating. The design is of benefit for the performance improvement of the beam splitter by new grating configuration compared with the conventional simple grating.
Shinzo Abe’s World War II Statement: Peace, Reflection and Global Contributions
Authors: LIM Tai Wei
Published: December 2015

This paper attempts to analyse Abe’s statement from two perspectives – pre-release and post-release. The approach offers an insight into how analysts were wrong/right and how different the Abe statement was from the report released by the Advisory Committee. The paper attempts to offer a balanced view of the statement while recognising the reservations from Japan’s neighbours. Comparisons between the pre-release and post-release phases would be made.
Equivalent circuit for the characterization of the resonance mode in piezoelectric systems
Authors: Fernández-Afonso Y. , García-Zaldívar O. , Calderón-Piñar F.
Published: December 2015

The impedance properties in polarized piezoelectric can be described by electric equivalent circuits. The classic circuit used in the literature to describe real systems is formed by one resistor (R), one inductance (L) and one capacitance C connected in series and one capacity ([Formula: see text]) connected in parallel with the formers. Nevertheless, the equation that describe the resonance and anti-resonance frequencies depends on a complex manner of R, L, C and [Formula: see text]. In this work is proposed a simpler model formed by one inductance (L) and one capacity (C) in series; one capacity ([Formula: see text]) in parallel; one resistor ([Formula: see text]) in parallel and one resistor ([Formula: see text]) in series with other components. Unlike the traditional circuit, the equivalent circuit elements in the proposed model can be simply determined by knowing the experimental values of the resonance frequency [Formula: see text], anti-resonance frequency [Formula: see text], impedance module at resonance frequency [Formula: see text], impedance module at anti-resonance frequency [Formula: see text] and low frequency capacitance [Formula: see text], without fitting the impedance experimental data to the obtained equation.
BiFeO3 codoping with Ba, La and Ti: Magnetic and structural studies
Authors: García-Zaldívar O. , Díaz-Castañón S. , Espinoza-Beltran F. J. , Hernández-Landaverde M. A. , López G. , Faloh-Gandarilla J. , Calderón-Piñar F.
Published: December 2015

Conventional solid state reaction method, from oxides and carbonates, was employed to prepare bismuth (Bi)-based multiferroic systems. The undoped BiFeO3 (BFO) and the codoped system with Ba, La and Ti (Bi[Formula: see text]BaxFe[Formula: see text]TiyO3, Bi[Formula: see text]BaxLazFe[Formula: see text]TiyO3) with x,y,[Formula: see text] were prepared stoichiometrically and sintered at two different temperatures. The structural and magnetic properties were investigated at room temperature. XRD measurements confirm the obtaining of the rhombohedral perovskite structure of the BFO family system. For the undoped system, some reflections of undesired phases are present for two different sintering temperatures, while for the doped system only one phase is present for both temperatures. The magnetic characterization at room temperature revealed remarkable differences between the ceramic samples. The results show that for undoped BFO system, spontaneous magnetization is not observed at room temperature. Nevertheless, in doped one, a well-defined ferromagnetic behavior is observed at room temperature, possible, due to the suppression of the spatially modulated spin structure of BFO promoted by the reduction of the rhombohedral distortion and the weakening of the Bi–O bonds. The XPS results confirm the presence of oxygen vacancies and the coexistence of Fe[Formula: see text] and Fe[Formula: see text] in all the studied samples. Calorimetric measurements reveal that the dopant incorporation has not a direct effect in Néel temperature but possibly yes in ferroelectric-paraelectric transition.
A transmit/reflect switchable frequency selective surface based on all dielectric metamaterials
Authors: Yu Fei , Wang Jun , Wang Jiafu , Ma Hua , Du Hongliang , Zhuo Xu , Qu Shaobo
Published: December 2015

In this paper, we propose a novel transmit/reflect switchable frequency selective surface (FSS) in millimeter wave band based on the effective medium theory under quasi-static limit, which is designed with square-hole elements cut from continuum dielectric plates. The building elements of the surface are composed of all dielectric metamaterial rather than metal material. With proper structural design and parameters tuning, the resonance frequencies can be tuned appropriately. The frequency response of the surface can be switched from that of a reflecting structure to a transmitting one by rotating the surface [Formula: see text], which means under different incident polarizations. The reflective response can be realized due to the effect of electric and magnetic resonances. Theoretical analysis shows that the reflective response arises from impedance mismatching by electric and magnetic resonances. And the transmitting response is the left-handed passband, arises from the coupling of the electric and magnetic resonances. In addition, effective electromagnetic parameters and the dynamic induced field distributions are analyzed to explain the mechanism of the responses. The method can also be used to design switchable all-dielectric FSS with continuum structures in other frequencies.
Structural and Electrochemical Studies of Rhodium Substituted Li2MnO3
Authors: Torres-Castro Loraine , Katiyar Ram S. , Manivannan A.
Published: December 2015

The theoretical capacity of Li2MnO3 as cathodic material for Li-ion batteries is known to be among the highest because of the presence of Li in the transition metal layer, however it suffers of inactivity due to Mn in tetravalent oxidation state. Several compositions such as Li2MnO3, Li2Mn0.5Rh0.5O3 and Li2RhO3 were synthesized by conventional solid state synthesis. XRD patterns indicated the presence of monoclinic phase for pristine Li2MnO3 and Li2RhO3. The 50% rhodium substitution into Li2MnO3 seems to form a composite of both Li2MnO3 and Li2RhO3. XPS analysis for Mn 2p orbital revealed a significant decrease in binding energy for Li2Mn0.5Rh0.5O3 composition, which indicates the possible reduction in the oxidation state of manganese. Cyclic voltammetry and charge/discharge analysis were also performed. A discharge capacity of 49 mAh/g for Li2MnO3, 187 mAh/g for Li2Mn0.5Rh0.5O3 and 130 mAh/g for Li2RhO3 were obtained for the first cycle.
Experimental Development of Alkaline and Acid-Alkaline Bipolar Membrane Electrolytes
Authors: McClure Joshua P. , Grew Kyle N. , Chu Deryn
Published: December 2015

Alkaline and acid-alkaline bipolar membrane electrolytes were prepared from cast and electrospun polymer membranes. The alkaline anion-exchange membrane (AEM) consisted of a polyphenylene oxide (PPO) backbone containing side-chain alkyl amine groups of various lengths. Different AEM membranes were investigated to down-select to a stable chemistry for preparing the acid-alkaline bipolar membrane. Nafion 117 was utilized as the proton-exchange membrane (PEM) component, and the PEM was joined to the AEM to form a PEM-AEM acid-alkaline bipolar membrane electrolyte. Different methods for joining the PEM-AEM were evaluated to determine compatibility matching between layers. In some cases, an electrospun layer junction between the PEM-AEM was created to assist in development. In-plane and through-plane ionic conductivity measurements were performed to evaluate the isolated AEM, PEM and PEM-AEM membranes.
Safety Characteristics of Chemically Delithiated Cathode Active Materials
Authors: Aoki Yasuhito , Yanagisawa Chika , Nakagawa Takeshi , Furushima Yoshitomo , Hasegawa Yuichi , Oda Mami
Published: December 2015

Cathode active materials in their charged state are obtained by chemical extraction of lithium, and the thermal and structural stability of cathode active materials alone were evaluated. Oxygen release was detected by TPD-MS and the cause of the oxygen release was assigned to the chemical structural change of cathode active material. During heating process, the surface structural changes were detected by Laser Raman spectroscopy, and the bulk structural changes were detected by XRD. The oxygen release were attributed to the crystallographic change from R3-m to Fd3m at around 270 °C and Fd3m to Fm3m at around 350 °C and the surface structural change started at around 150 °C . It was elucidated that surface decomposition starts 100 °C lower than the bulk decomposition in the charged state.
In-Situ Examination of Microstructural Changes within a Lithium-Ion Battery Electrode Using Synchrotron X-ray Microtomography
Authors: Taiwo Oluwadamilola O. , Eastwood David S , Lee Peter D , Paz-García Juan M. , Hall Stephen A , Brett Daniel J.L , Shearing Paul R.
Published: December 2015

In this work, we use synchrotron X-ray microtomographic imaging to examine in-situ changes in a silicon / lithium half-cell before and after lithiation. We visualize volume expansion within the silicon electrode matrix and active particle fracturing as a result of the lithiation process. A change in volume fraction of silicon with respect to electrode state-of-charge was also characterized.
Investigating the Aging Effect of Current Ripple on Lithium-Ion Cells
Authors: Bessman Alexander , Soares Rudi , Behm Mårten , Lindbergh Göran , Wallmark Oskar , Leksell Mats , Svens Pontus
Published: December 2015

We have built an experimental setup which exposes twelve cells to a well-defined ripple current. It consists of a system for cycling high capacity cells in parallel with a triangular current waveform superimposed on top of the direct current. The frequency of the waveform is variable up to 50 Hz, and the sum of the DC and AC components can have a magnitude of -40 A to 40 A. Current is measured over a 500 µΩ shunt resistor. The voltage and current of each cell is read simultaneously at a sample rate up to 4 MS/s, allowing for precise impedance measurements even for high frequency harmonics. The cells are cycled at 40 °C. The experiment has been designed to eliminate indirect effects of the AC harmonics as far as possible. This system is being used to test whether or not AC harmonics affect Li-ion aging.
A Bifunctional Air Electrode Catalyzed by Lead Ruthenate for Li-Air Batteries
Authors: Yuan Xiao-Zi , Toupin Mathieu , Qu Wei , Laforgue Alexis , Fahlman Jason , Jiang Max
Published: December 2015

The performance of a catalyst enforced commercially available gas diffusion layer (GDL) electrode was evaluated at different discharge rates and depths in non-aqueous Li-O2 batteries. The lead ruthenate (PbRuO) powder with a pyrochlore structure was employed as the catalyst. The lead ruthenate pyrochlore was prepared using a direct soft template method and characterized by X-ray diffraction (XRD), nitrogen physisorption techniques and transmission electron microscopy (TEM). The charge/discharge capabilities of the PbRuO/Ketjenblack (KB) composite were studied in tetraethyleneglycol dimethyl ether (TEGDME) containing 1M lithium triflate. The results show that PbRuO/KB can enhance the cell performance at high charge/discharge rates. Moreover, at a current density of 0.1mA/cm2 it significantly increases the cell cyclability. With a cut-off capacity of 1000 mAh/g (PbRuO/KB only) the cell reached 100 cycles. As such, lead ruthenate has the potential to be used as an efficient bifunctional electrocatalyst for non-aqueous Li-O2 batteries.
The Carbon-Electrolyte Interface at High Cathodic Voltages
Authors: Eikeland Nilssen Benedicte , Tezel Ahmet Oguz , Svensson Ann Mari
Published: December 2015

Different carbon materials (graphitic and carbon black) were investigated with respect to their electrochemical stability at high voltages in organic electrolytes typically used for Li-ion batteries. The materials were characterized with respect to crystallinity, surface area and surface structure. Electrodes were fabricated from all materials, and characterized by electrochemical techniques, including galvanostatic cycling, cyclic voltammetry, as well as by in-situ XRD. The results from galvanostatic cycling show that the first cycle irreversible loss correlates with the edge surface area, and that the decomposition products are limiting intercalation and de-intercalation after multiple cycles. Structural damage is observed for both graphitic materials by in-situ XRD during the first cycle, no further damage was observed upon repeated cycling. A means of improving reversibility and preventing structural damage of the carbon materials is finally suggested, based on results obtained with an anion receptor additive.
Nonvolatile Memory Based on Polymer-Suspended Graphene Nanoplatelets with Fractional and Integer Quantum Conductance at 300K and Zero Magnetic Field
Authors: Kang Yuhong , Ruan Hang , Heremans Jean J , Orlowski Marius K
Published: December 2015

Quantized conductance is observed at room temperature in metal-insulator-metal structures with graphene submicron-sized nanoplatelets embedded in a 3-hexylthiophene (P3HT) polymer layer. In devices with medium concentration of graphene platelets, integer multiples of conductance Go=2e2/h (=12.9 kΩ)-1 are observed. In some devices partial quantized conductance steps are observed,, including a series with (n/7)×Go steps. As an organic memory, the device exhibits reliable memory operation with an ON/OFF ratio of more than 10. We attribute the quantized conduction to the existence of a 1D electron waveguide along the conductive path. Such a memory device can be viewed as a realization of a quantum memristor.
Corrosion Protection of Silicon Micro Systems with Ultra-Thin Barrier Films for Miniaturized Medical Devices
Authors: Herrera Morales Jorge Mario , Souriau Jean-Charles , Simon Gilles
Published: December 2015

Implantable micro devices employing packaging technologies other than metallic enclosures are yet to be developed. Packaging films deposited by chemical vapor deposition are good candidates for this task due to their low permeability to gases, low chemical reactivity and high conformality. Nine biocompatible materials were studied: Al2O3, BN, DLC, HfO2, SiC, SiN, SiO2, SiOC and TiO2. Ultra-thin films (5─100 nm) were deposited by plasma enhanced chemical vapor deposition (PECVD) or atomic layer deposition (ALD) on substrates commonly found in microelectronic devices: crystalline silicon, copper and tungsten nitride. It was found that deposited films of BN, SiC, SiO2 and SiN do not offer corrosion protection of substrates in hot saline solution. Whereas, films of Al2O3, DLC, SiOC and TiO2 showed very low chemical reactivity in saline baths, and multilayers of TiO2 on top of Al2O3 displayed remarkable corrosion protection of selected substrates.
The Effect of Brighteners on the Fabrication of Electroplated Bright Aluminum Films Using an AlCl3-EMIC-Toluene Bath
Authors: Uehara Kazuma , Gunji Takao , Tanabe Toyokazu , Kaneko Shingo , Matsumoto Futoshi
Published: December 2015

The effect of brighteners such as 4-pyridinecarboxylic acid hydrazide (4-PCAH), 3-pyridinecarboxylic acid hydrazide (3-PCAH), 2-pyridinecarboxylic acid hydrazide (2-PCAH) and conventional 1,10-phenanthroline (PH) on the electrodeposition efficiency and brightness of aluminum (Al) was investigated. Electrodeposited Al films were prepared with constant currents in an aluminum chloride (AlCl3)-ethyl-3-methylimidazolium chloride (EMIC)-toluene bath, and the results were compared using a scanning electron microscope (SEM) and UV-vis spectrometer. Among the four brighteners used in this study, 4-PCAH exhibited the highest brightness on the electrodeposited Al surfaces.
On the Applications of Newly Architectured CdTe Nanostructures from Ionic Liquid Medium
Authors: Chauhan Khushbu R , Patel Dipal B , Mukhopadhyay Indrajit
Published: December 2015

The 2D nanostructures are gaining lot of interest in the field of electronics and solar photovoltaics. We have recently developed new shape and architecture of CdTe nanostructures on the low cost F:SnO2 (FTO) substrate by electrodeposition from ionic liquid (IL) medium. The initial results of the Schottky and p-n junction solar cells out of nanostructured CdTe thin films are shown in this paper. With the Schottky junction solar cells of such nanostructured films higher Voc of 790 mV was obtained. On the other hand, it was found that stoichiometric CdTe films can only be deposited on less than 50 nm thick film of CdS. The first ever successful deposition of stoichiometric CdTe film on CdS buffer layer resulted in a solar cell with Voc of 150 mV, Jsc of 500 µA/cm2, Fill Factor of 27% and efficiency of 0.02%.
Electrodeposition and Characterization of Selective Coatings Based on Black Cobalt for Solar-to-Thermal Energy Conversion
Authors: Herrera-Zamora Dallely Melissa , Lizama-Tzec Francisco Ivan , Arés Oscar , Oskam Gerko
Published: December 2015

The desired optical properties of selective coatings for solar-to-thermal energy conversion include a high absorbance in the wavelength region of the solar spectrum, coupled with a low thermal emittance in the infrared upon heating of the substrate and coating. Selective coatings consisting of a metallic nickel interlayer and black cobalt top layer have been deposited onto a copper substrate using electrodeposition. The coatings have been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The total reflectance spectra in the UV-visible and IR were evaluated before and after a thermal treatment at 300 ºC, and it was observed that the optical properties were not affected, suggesting a good thermal stability of the selective coatings. The solar absorbance of around 90% and thermal emissivity of 15-20% indicate that the optical properties of these selective coatings are suitable for low to medium temperature solar-to-thermal energy conversion applications.
Properties of Pulse Electrodeposited CuInGaSe2 Films
Authors: Murali Kollegal Ramakrishna , Chitra V
Published: December 2015

CuIn1-xGaxSe2 films of different composition (0< x <1), were pulse electrodeposited on indium tin oxide coated glass and molybdenum substrates at 50 % duty cycle and at room temperature. The films exhibited single phase chalcopyrite structure. The band gap of the films increased from 1.11 eV to 1.62 eV as the gallium concentration increased. The magnitude of the room temperature resistivity increased from 0.8 ohm cm to 23.52 ohm cm as the gallium concentration is increased. . Films of composition CuIn0.7Ga0.3Se2 exhibit maximum Voc. The power output characteristics after 80s photoetching indicates a Voc of 0.70V, Jsc of 20.0 mA cm-2, ff of 0.71 and h of 14.33 %, for 60 mW cm-2 illumination.