bluuebunny/crossref_metadata_2025 huggingface dataset:
Membrane-Bound PenA β-Lactamase of Burkholderia pseudomallei
Authors: Randall Linnell B. , Dobos Karen , Papp-Wallace Krisztina M. , Bonomo Robert A. , Schweizer Herbert P.
Published: December 2015

Burkholderia pseudomallei
is the etiologic agent of melioidosis, a difficult-to-treat disease with diverse clinical manifestations. β-Lactam antibiotics such as ceftazidime are crucial to the success of melioidosis therapy. Ceftazidime-resistant clinical isolates have been described, and the most common mechanism is point mutations affecting expression or critical amino acid residues of the chromosomally encoded class A PenA β-lactamase. We previously showed that PenA was exported via the twin arginine translocase system and associated with the spheroplast fraction. We now show that PenA is a membrane-bound lipoprotein. The protein and accompanying β-lactamase activity are found in the membrane fraction and can be extracted with Triton X-114. Treatment with globomycin of
B. pseudomallei
cells expressing PenA results in accumulation of the prolipoprotein. Mass spectrometric analysis of extracted membrane proteins reveals a protein peak whose mass is consistent with a triacylated PenA protein. Mutation of a crucial lipobox cysteine at position 23 to a serine residue results in loss of β-lactamase activity and absence of detectable PenA
C23S
protein. A concomitant isoleucine-to-alanine change at position 20 in the signal peptide processing site in the PenA
C23S
mutant results in a nonlipidated protein (PenA
I20A C23S
) that is processed by signal peptidase I and exhibits β-lactamase activity. The resistance profile of a
B. pseudomallei
strain expressing this protein is indistinguishable from the profile of the isogenic strain expressing wild-type PenA. The data show that PenA membrane association is not required for resistance and must serve another purpose.
Mutation in the Hepatitis E Virus Polymerase and Outcome of Ribavirin Therapy
Authors: Lhomme Sebastien , Kamar Nassim , Nicot Florence , Ducos Jacques , Bismuth Michael , Garrigue Valerie , Petitjean-Lecherbonnier Joelle , Ollivier Isabelle , Alessandri-Gradt Elodie , Goria Odile , Barth Heidi , Perrin Peggy , Saune Karine , Dubois Martine , Carcenac Romain , Lefebvre Caroline , Jeanne Nicolas , Abravanel Florence , Izopet Jacques
Published: December 2015

Hepatitis E virus (HEV) can lead to chronic infection in solid-organ transplant patients. Ribavirin is efficient for treatment of chronically infected patients. Recently, the1634R mutation in the HEV polymerase has been associated with treatment failure. However, it is unclear if this mutation can be used as a prognostic marker of treatment outcome. We studied the prevalence of the 1634R mutation in the HEV polymerase of patients starting ribavirin therapy, the influence of the 1634R variants on the viral response, the frequency of the 1634R mutation in patients whose treatment failed, and its impact on ribavirin retreatment. We analyzed pretreatment samples from 63 solid-organ transplant patients with chronic hepatitis E using deep sequencing; 42 patients had a sustained virologic response (SVR), and 21 were non-SVR patients. We detected the 1634R variant by deep sequencing in 36.5% (23/63) of the patients (proportions, 1.3 to 100%). The 1634R variant was detected in 31.0% (13/42) of baseline plasma samples from patients with SVR and in 47.6% (10/21) in the other patients (
P
= 0.2). The presence of this mutation did not influence the initial decrease in viral RNA. Lastly, a second prolonged ribavirin treatment led to SVR in 70% of the patients who initially did not have SVR, despite the presence of the 1634R variant. We conclude that the presence of the 1634R variant at ribavirin initiation does not lead to absolute ribavirin resistance. Although its proportion increased in patients whose treatment failed, the presence of the 1634R variant did not compromise the response to a second ribavirin treatment.
Differential Mechanisms of Tenofovir and Tenofovir Disoproxil Fumarate Cellular Transport and Implications for Topical Preexposure Prophylaxis
Authors: Taneva Ekaterina , Crooker Kerry , Park Sung Hyun , Su Jonathan T. , Ott Adina , Cheshenko Natalia , Szleifer Igal , Kiser Patrick F. , Frank Bruce , Mesquita Pedro M. M. , Herold Betsy C.
Published: December 2015

Intravaginal rings releasing tenofovir (TFV) or its prodrug, tenofovir disoproxil fumarate (TDF), are being evaluated for HIV and herpes simplex virus (HSV) prevention. The current studies were designed to determine the mechanisms of drug accumulation in human vaginal and immune cells. The exposure of vaginal epithelial or T cells to equimolar concentrations of radiolabeled TDF resulted in over 10-fold higher intracellular drug levels than exposure to TFV. Permeability studies demonstrated that TDF, but not TFV, entered cells by passive diffusion. TDF uptake was energy independent but its accumulation followed nonlinear kinetics, and excess unlabeled TDF inhibited radiolabeled TDF uptake in competition studies. The carboxylesterase inhibitor bis-nitrophenyl phosphate reduced TDF uptake, suggesting saturability of intracellular carboxylesterases. In contrast, although TFV uptake was energy dependent, no competition between unlabeled and radiolabeled TFV was observed, and the previously identified transporters, organic anion transporters (OATs) 1 and 3, were not expressed in human vaginal or T cells. The intracellular accumulation of TFV was reduced by the addition of endocytosis inhibitors, and this resulted in the loss of TFV antiviral activity. Kinetics of drug transport and metabolism were monitored by quantifying the parent drugs and their metabolites by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Results were consistent with the identified mechanisms of transport, and the exposure of vaginal epithelial cells to equimolar concentrations of TDF compared to TFV resulted in ∼40-fold higher levels of the active metabolite, tenofovir diphosphate. Together, these findings indicate that substantially lower concentrations of TDF than TFV are needed to protect cells from HIV and HSV-2.
Evaluation of Daptomycin Exposure and Efficacy and Safety Endpoints To Support Risk-versus-Benefit Considerations
Authors: Bhavnani Sujata M. , Ambrose Paul G. , Hammel Jeffrey P. , Rubino Christopher M. , Drusano George L.
Published: December 2015

The choice of an antimicrobial agent must balance optimization of efficacy endpoints with the minimization of safety events. The risk versus benefit of daptomycin for patients with
Staphylococcus aureus
bacteremia with or without infective endocarditis receiving daptomycin at 6, 8, and 10 mg/kg of body weight/day was assessed. The relationships between the area under the concentration-time curve over 24 h (AUC)/MIC ratio and both clinical response and time to decreased susceptibility were evaluated using data from patients with such infections who received daptomycin at 6 mg/kg/day. Using these relationships, plus the previously identified relationship between the minimum concentration and an elevation in the creatine phosphokinase (CPK) concentration (CPK elevation) (S. M. Bhavnani, C. M. Rubino, P. G. Ambrose, and G. L. Drusano, Clin Infect Dis 50:1568–1574, 2010) and Monte Carlo simulation, the probability of each outcome by MIC for daptomycin at 6, 8, and 10 mg/kg/day was calculated. The function for exposure-response relationships for clinical response (
P
= 0.06) and time to decreased susceptibility (
P
= 0.01) resembled U and inverted U shapes, respectively. Multivariable analyses demonstrated AUC/MIC ratio, creatinine clearance, albumin concentration, and disease category to be predictors of clinical response. The results of simulations failed to demonstrate large improvements in the probabilities of clinical success among cohorts of simulated patients defined by the above-described predictive factors or the probability of decreased susceptibility at 30 days when the daptomycin dose was increased from 6 to 10 mg/kg/day. The probability of CPK elevation increased from 0.073 to 0.156 over this dose range. These data can be used to inform risk-versus-benefit decisions for daptomycin dose selection in patients with
S. aureus
bacteremia with or without infective endocarditis. The risk of CPK elevation, which is reversible, should be weighed in the context of the mortality and severe morbidity associated with these types of serious staphylococcal infections.
Flocculation-Related Gene Identification by Whole-Genome Sequencing of Thauera aminoaromatica MZ1T Floc-Defective Mutants
Authors: Prombutara P. , Allen M. S.
Published: December 2015

Thauera aminoaromatica
MZ1T, a floc-forming bacterium isolated from an industrial activated-sludge wastewater treatment plant, overproduces exopolysaccharide (EPS), leading to viscous bulking. This phenomenon results in poor sludge settling and dewatering during the clarification process. To identify genes responsible for bacterial flocculation, a whole-genome phenotypic-sequencing technique was applied. Genomic DNA of MZ1T flocculation-deficient mutants was subjected to massively parallel sequencing. The resultant high-quality reads were assembled and compared to the reference genome of the wild type (WT). We identified nine nonsynonymous mutations and one nonsense mutation putatively involved in EPS biosynthesis. Complementation of the nonsense mutation located in an EPS deacetylase gene restored the flocculating phenotype. The Fourier transform infrared (FTIR) spectra of EPS isolated from the wild type showed a reduced C=O peak of the
N
-acetyl group at 1,665 cm
−1
compared to the spectra of MZ1T floc-deficient mutant EPS, suggesting that the WT EPS was partially deacetylated. Gene expression analysis also demonstrated that the putative deacetylase gene transcript increased before flocculation occurred. These data suggest that targeting deacetylation processes via direct chemical modification of EPS or enzyme inhibition may prove useful in combating viscous bulking in this and related bacteria.
New Coffee Plant-Infecting Xylella fastidiosa Variants Derived via Homologous Recombination
Authors: Jacques Marie-Agnès , Denancé Nicolas , Legendre Bruno , Morel Emmanuelle , Briand Martial , Mississipi Stelly , Durand Karine , Olivier Valérie , Portier Perrine , Poliakoff Françoise , Crouzillat Dominique
Published: December 2015

Xylella fastidiosa
is a xylem-limited phytopathogenic bacterium endemic to the Americas that has recently emerged in Asia and Europe. Although this bacterium is classified as a quarantine organism in the European Union, importation of plant material from contaminated areas and latent infection in asymptomatic plants have engendered its inevitable introduction. In 2012, four coffee plants (
Coffea arabica
and
Coffea canephora
) with leaf scorch symptoms growing in a confined greenhouse were detected and intercepted in France. After identification of the causal agent, this outbreak was eradicated. Three
X. fastidiosa
strains were isolated from these plants, confirming a preliminary identification based on immunology. The strains were characterized by multiplex PCR and by multilocus sequence analysis/typing (MLSA-MLST) based on seven housekeeping genes. One strain, CFBP 8073, isolated from
C. canephora
imported from Mexico, was assigned to
X. fastidiosa
subsp.
fastidiosa/X. fastidiosa
subsp.
sandyi
. This strain harbors a novel sequence type (ST) with novel alleles at two loci. The two other strains, CFBP 8072 and CFBP 8074, isolated from
Coffea arabica
imported from Ecuador, were allocated to
X. fastidiosa
subsp.
pauca
. These two strains shared a novel ST with novel alleles at two loci. These MLST profiles showed evidence of recombination events. We provide genome sequences for CFBP 8072 and CFBP 8073 strains. Comparative genomic analyses of these two genome sequences with publicly available
X. fastidiosa
genomes, including the Italian strain CoDiRO, confirmed these phylogenetic positions and provided candidate alleles for coffee plant adaptation. This study demonstrates the global diversity of
X. fastidiosa
and highlights the diversity of strains isolated from coffee plants.
Important Metabolic Pathways and Biological Processes Expressed by Chicken Cecal Microbiota
Authors: Polansky Ondrej , Sekelova Zuzana , Faldynova Marcela , Sebkova Alena , Sisak Frantisek , Rychlik Ivan
Published: December 2015

The gut microbiota plays important roles in its host. However, how each microbiota member contributes to the behavior of the whole population is not known. In this study, we therefore determined protein expression in the cecal microbiota in chickens of selected ages and in 7-day-old chickens inoculated with different cecal extracts on the day of hatching.
Campylobacter
,
Helicobacter
,
Mucispirillum
, and
Megamonas
overgrew in the ceca of 7-day-old chickens inoculated with cecal extracts from donor hens.
Firmicutes
were characterized by ABC and phosphotransferase system (PTS) transporters, extensive acyl coenzyme A (acyl-CoA) metabolism, and expression of
l
-fucose isomerase.
Anaerostipes
,
Anaerotruncus
,
Pseudoflavonifractor
,
Dorea
,
Blautia
, and
Subdoligranulum
expressed spore proteins.
Firmicutes
(
Faecalibacterium
,
Butyrivibrio
,
Megasphaera
,
Subdoligranulum
,
Oscillibacter
,
Anaerostipes
, and
Anaerotruncus
) expressed enzymes required for butyrate production.
Megamonas
,
Phascolarctobacterium
, and
Blautia
(exceptions from the phylum
Firmicutes
) and all
Bacteroidetes
expressed enzymes for propionate production pathways. Representatives of
Bacteroidetes
also expressed xylose isomerase, enzymes required for polysaccharide degradation, and ExbBD, TonB, and outer membrane receptors likely to be involved in oligosaccharide transport. Based on our data,
Anaerostipes
,
Anaerotruncus
, and
Subdoligranulum
might be optimal probiotic strains, since these represent spore-forming butyrate producers. However, certain care should be taken during microbiota transplantation because the microbiota may behave differently in the intestinal tract of a recipient depending on how well the existing communities are established.
Phosphoenolpyruvate Phosphotransferase System Components Modulate Gene Transcription and Virulence of Borrelia burgdorferi
Authors: Khajanchi Bijay K. , Odeh Evelyn , Gao Lihui , Jacobs Mary B. , Philipp Mario T. , Lin Tao , Norris Steven J.
Published: December 2015

The phosphoenolpyruvate phosphotransferase system (PEP-PTS) and adenylate cyclase (AC) IV (encoded by BB0723 [
cyaB
]) are well conserved in different species of
Borrelia
. However, the functional roles of PEP-PTS and AC in the infectious cycle of
Borrelia
have not been characterized previously. We examined 12 PEP-PTS transporter component mutants by needle inoculation of mice to assess their ability to cause mouse infection. Transposon mutants with mutations in the EIIBC components (
ptsG
) (BB0645, thought to be involved in glucose-specific transport) were unable to cause infection in mice, while all other tested PEP-PTS mutants retained infectivity. Infectivity was partially restored in an in
trans
-complemented strain of the
ptsG
mutant. While the
ptsG
mutant survived normally in unfed as well as fed ticks, it was unable to cause infection in mice by tick transmission, suggesting that the function of
ptsG
is essential to establish infection by either needle inoculation or tick transmission. In Gram-negative organisms, the regulatory effects of the PEP-PTS are mediated by adenylate cyclase and cyclic AMP (cAMP) levels. A recombinant protein encoded by
B. burgdorferi
BB0723 (a putative
cyaB
homolog) was shown to have adenylate cyclase activity
in vitro
; however, mutants with mutations in this gene were fully infectious in the tick-mouse infection cycle, indicating that its function is not required in this process. By transcriptome analysis, we demonstrated that the
ptsG
gene may directly or indirectly modulate gene expression of
Borrelia burgdorferi
. Overall, the PEP-PTS glucose transporter PtsG appears to play important roles in the pathogenesis of
B. burgdorferi
that extend beyond its transport functions.
Discrete Responses to Limitation for Iron and Manganese in Agrobacterium tumefaciens: Influence on Attachment and Biofilm Formation
Authors: Heindl Jason E. , Hibbing Michael E. , Xu Jing , Natarajan Ramya , Buechlein Aaron M. , Fuqua Clay
Published: December 2015

Transition metals such as iron and manganese are crucial trace nutrients for the growth of most bacteria, functioning as catalytic cofactors for many essential enzymes. Dedicated uptake and regulatory systems have evolved to ensure their acquisition for growth, while preventing toxicity. Transcriptomic analysis of the iron- and manganese-responsive regulons of
Agrobacterium tumefaciens
revealed that there are discrete regulatory networks that respond to changes in iron and manganese levels. Complementing earlier studies, the iron-responsive gene network is quite large and includes many aspects of iron-dependent metabolism and the iron-sparing response. In contrast, the manganese-responsive network is restricted to a limited number of genes, many of which can be linked to transport and utilization of the transition metal. Several of the target genes predicted to drive manganese uptake are required for growth under manganese-limited conditions, and an
A. tumefaciens
mutant with a manganese transport deficiency is attenuated for plant virulence. Iron and manganese limitation independently inhibit biofilm formation by
A. tumefaciens
, and several candidate genes that could impact biofilm formation were identified in each regulon. The biofilm-inhibitory effects of iron and manganese do not rely on recognized metal-responsive transcriptional regulators, suggesting alternate mechanisms influencing biofilm formation. However, under low-manganese conditions the
dcpA
operon is upregulated, encoding a system that controls levels of the cyclic di-GMP second messenger. Mutation of this regulatory pathway dampens the effect of manganese limitation.

IMPORTANCE
Responses to changes in transition metal levels, such as those of manganese and iron, are important for normal metabolism and growth in bacteria. Our study used global gene expression profiling to understand the response of the plant pathogen
Agrobacterium tumefaciens
to changes of transition metal availability. Among the properties that are affected by both iron and manganese levels are those required for normal surface attachment and biofilm formation, but the requirement for each of these transition metals is mechanistically independent from the other.
Hypopharyngeal large cell neuroendocrine carcinoma
Authors: Lee Wei-I , Ameratunga Malaka , du Plessis Justin , Gan Hui
Published: December 2015

Neuroendocrine carcinoma (NEC) of the head and neck is rare. We report a case of a 56-year-old man with a 6-week history of dysphagia, a neck mass and weight loss. He was diagnosed with a hypopharyngeal large cell NEC (LCNEC) with metastases to multiple sites. He received two cycles of cisplatin and etoposide. Subsequent restaging scan revealed progressive disease. The patient declined further chemotherapy and died shortly after. This is the third case of LCNEC of hypopharynx reported in the English literature and the first to progress on platinum-based chemotherapy. Although LCNEC of the head and neck is still classified as an atypical carcinoid, there is increasing evidence it is a distinct clinicohistopathological entity that carries an especially poor prognosis. Currently, there is a paucity of data to guide treatment of this rare malignancy.
Klinefelter syndrome with low gonadotropin levels
Authors: Cherian Kripa Elizabeth , Jebasingh Felix K , Kapoor Nitin , Paul Thomas Vizhalil
Published: December 2015

Klinefelter syndrome is usually characterised by the presence of a eunuchoid body habitus and testes that are usually small and firm, with low testosterone, and elevated luteinising hormone and follicle-stimulating hormone levels, consistent with hypergonadotropic hypogonadism. Low levels of gonadotropins in karyotypically proven cases are not expected, they are extremely rare occurrences. We report a case of a patient who was diagnosed to have Klinefelter syndrome (47 XXY) with low gonadotropin levels. The rest of his anterior pituitary hormonal profile was normal with no lesions in the pituitary gland on imaging. He was continued on androgen replacement therapy.
An unusual complication of epistaxis: cerebral abscess formation after anterior ethmoidal artery ligation
Authors: Murer Karin , Holzmann David , Burkhardt Jan-Karl , Soyka Michael Benjamin
Published: December 2015

Epistaxis is a very common emergency in otorhinolaryngology. Anterior ethmoidal artery ligation using an external approach is one of the surgical options in posterior epistaxis. We present, to the best of our knowledge, the first reported case of an intracerebral abscess after epistaxis treatment with ligation of the anterior ethmoidal artery using an endoscopic-assisted external approach in a 56-year-old patient. The patient presented 4 days postoperatively with an orbital cellulitis. A CT was performed and a frontobasal hypodensity was found. An additional MR tomography the next day showed a lesion suspicious for an intracerebral abscess. Despite intravenous antibiotic therapy, the lesion increased and was successfully treated by the neurosurgeons, with abscess resection over a craniotomy and frontobasal repair using a pedicled periosteal flap. Surgeons have to be aware of this rare but possibly lethal severe complication and should consider early imaging studies, especially if a periorbital cellulitis appears.
Quantum switch in coupled-resonator array: Controlling single-photon transport by the state of two-level system
Authors: Qin Xiao-Ke
Published: December 2015

We present the model that two-level system (TLS) nonlocally interacts with one-dimensional coupled-resonator array (CRA). The coherent transport of single-photon inside CRA is well controlled by the state of TLS, which functions as quantum switch. Spin up and spin down correspond to switch on and switch off respectively, or vice versa, which originate from the constructive interference and the destructive interference of two coupling paths. We improve the fidelity of quantum switch by preadjusting the frequency of resonators which couple to TLS. Quantum switch realizes quantum beam splitter when TLS is in the superposition state. The single-photon wave packet would entangle with qubit and propagate to the remote resonators.
Analytical calculation of electron group velocity surfaces in uniform strained graphene
Authors: Gómez-Arias Wilfrido A. , Naumis Gerardo G.
Published: December 2015

Electron group velocity for graphene under uniform strain is obtained analytically by using the tight-binding (TB) approximation. Such closed analytical expressions are useful in order to calculate the electronic, thermal and optical properties of strained graphene. These results allow to understand the behavior of electrons when graphene is subjected to strong strain and nonlinear corrections, for which the usual Dirac approach is no longer valid. Some particular cases of uniaxial and shear strain were analyzed. The evolution of the electron group velocity indicates a break-up of the trigonal warping symmetry, which is replaced by a warping consistent with the symmetry of the strained reciprocal lattice. To do this, analytical expressions for the shape of the first Brillouin zone (BZ) of the honeycomb strained reciprocal lattice are provided. Finally, the Fermi velocity becomes strongly anisotropic, i.e., for a strong pure shear strain (20% of the lattice parameter), the two inequivalent Dirac cones merge and the Fermi velocity is zero in one of the principal axis of deformation. We found that nonlinear terms are essential to describe the effects of deformation for electrons near or at the Fermi energy.
Discrete resonances
Authors: Vivaldi Franco
Published: December 2015

The concept of resonance has been instrumental to the study of Hamiltonian systems with divided phase space. One can also define such systems over discrete spaces, which have a finite or countable number of points, but in this new setting the notion of resonance must be re-considered from scratch. I review some recent developments in the area of arithmetic dynamics which outline some salient features of linear and nonlinear stable (elliptic) orbits over a discrete space, and also underline the difficulties that emerge in their analysis.
Microscopic approach to the magnetoelectric coupling in RCrO3
Authors: Apostolov A. T. , Apostolova I. N. , Wesselinowa J. M.
Published: December 2015

A microscopic model is proposed to describing the multiferroic properties in [Formula: see text], where [Formula: see text] is the magnetic rare earth ion. Using the Green’s function theory, the weak ferromagnetism and the coercive field are calculated by a balance between the Dzyaloshinskii–Moriya interaction (DMI), the single-ion anisotropy and the exchange interaction. We have discussed the magnetic rotational spin-reorientation (SR) transition between [Formula: see text] and [Formula: see text] phases in [Formula: see text] and the abrupt one between [Formula: see text] and [Formula: see text] in [Formula: see text] calculating the energies in the corresponding phases. The type of the phase transition in [Formula: see text] is determined by the sign of the second magnetic anisotropy constant. In order to investigate the origin of the extraordinary ferroelectricity in [Formula: see text], we have studied the different contributions in the polarization due to the antisymmetric exchange DMI and the magnetostriction arising from the Cr-ordering. It is shown that the polarization is due to the interaction between the magnetic [Formula: see text]- and Cr-ions. The influence of a magnetic field on the polarization and of an electric field on the magnetization are also calculated as an evidence for a strong magnetoelectric coupling in [Formula: see text].
The bondage number of the strong product of a complete graph with a path and a special starlike tree
Authors: Zhao Weisheng , Zhang Heping
Published: December 2015

The bondage number [Formula: see text] of a graph [Formula: see text] is the cardinality of a minimum edge set whose removal from [Formula: see text] results in a graph with the domination number greater than that of [Formula: see text]. It is a parameter to measure the vulnerability of a communication network under link failure. In this paper, we obtain the exact value of the bondage number of the strong product of a complete graph and a path. That is, for any two integers [Formula: see text] and [Formula: see text], [Formula: see text] if [Formula: see text]; [Formula: see text] if [Formula: see text] (mod 3); [Formula: see text] if [Formula: see text] (mod 3). Furthermore, we determine the exact value of the bondage number of the strong product of a complete graph and a special starlike tree.
China and the United States: Towards a New Model of Major Power Relations?
Authors: HU Weixing
Published: December 2015

The China-US disagreement over the term of “new model of major power relations” is not just about discourse; rather, it is about who will have the upper hand in defining the terms for future China-US relations. While the Chinese want to provide a new vision and an alternative to the realist discourse of future China-US relations, the Americans believe that Beijing tries to claim a position on par with the United States in world affairs.
Who are More Nationalistic on the Chinese Internet?
Authors: SHAN Wei
Published: December 2015

A web-based public opinion survey shows that Chinese nationalism is associated with conservative ideologies in politics, economy and culture. A nationalist in China generally supports an authoritarian government, respects national unity and security, endorses state influences in socioeconomic issues and values traditional cultures. People with higher income are generally less nationalistic. Education is negatively related to nationalism. The oldest and youngest cohorts are more nationalistic than those in their middle age.
Trends of Private Consumption in the Restructuring of China’s Economy
Authors: CHEN Chien-Hsun
Published: December 2015

The benefits deriving from rapid economic growth have chiefly accrued to capital returns. Consequently, the decline in the share of Chinese gross domestic product (GDP) accounted for by labour income has been most pronounced. To sustain growth, China will have to ensure robust consumption. Increasing the labour share in GDP and hence promoting domestic consumption will play a decisive role in rebalancing China’s economy.
Pyroelectric property of SrTiO3/Si ferroelectric-semiconductor heterojunctions near room temperature
Authors: Bai Gang , Wu Dongmei , Xie Qiyun , Guo Yanyan , Li Wei , Deng Licheng , Liu Zhiguo
Published: December 2015

A nonlinear thermodynamic formalism is developed to calculate the pyroelectric property of epitaxial single domain [Formula: see text] heterojunctions by taking into account the thermal expansion misfit strain at different temperatures. It has been demonstrated that the crucial role was played by the contribution associated with the structure order parameter arising from the rotations of oxygen octahedral on pyroelectricity. A dramatic decrease in the pyroelectric coefficient due to the strong coupling between the polarization and the structure order parameter is found at ferroelectric [Formula: see text]–[Formula: see text] phase transition. At the same time, the thermal expansion mismatch between film and substrate is also found to provide an additional weak decrease of pyroelectricity. The analytic relationship of the out-of-plane pyroelectric coefficient and dielectric constant of ferroelectric phases by considering the thermal expansion of thin films and substrates has been determined for the first time. Our research provides another avenue for the investigation of the pyroelectric effects of ferroic thin films, especially, such as antiferroelectric and multiferroic materials having two or more order parameters.
Impact of Cathode Current Collector on High Temperature PEM Water Electrolysis
Authors: Li Hua , Inada Akiko , Nakajima Hinonori , Ito Kohei
Published: December 2015

The effect of cathode current collectors on polymer electrolyte membrane water electrolysis (PEMWE) was evaluated with I-V and I-high frequency resistance (HFR) characteristics. Results reveal that cathode current collectors can impact water electrolysis performance by controlling the amount of water accumulation there, which is proved with overpotential analysis and systematic operation such as feeding additional nitrogen gas to cathode. The hydrophilic cathode current collectors invited better performance than hydrophobic ones, because the hydrophilic ones gives less water accumulation there and enough water content in catalyst coated membrane (CCM). The thickness of cathode current collector did not impact the performance.
Preparation of NiCl2 Nanorods with Enhanced Electrochemical Properties in Thermal Batteries
Authors: Zhu Yan-Li , Xing Jia-Chao , Yang Bo , Jiao Qing-Jie
Published: December 2015

Single-crystalline NiCl2 nanorods with approximately 80-200 nm in diameter have been successfully prepared via recrystallization. Thermal batteries consisting of six single cells were fabricated for discharge measurements. The results showed that thermal batteries employing NiCl2 nanorods as cathode could maintain 114 s and 95 s until the potential fell to 10.5 V at constant current densities of 0.303 A cm-1 and 0.424 A cm-1, respectively. The average open circuit voltage of a singel cell after activation can reach as high as 2.445 V, close to its theoretical electrochemical window of 2.640 V in molten electrolytes.
Improving Battery Safety for Electric Vehicles through the Optimization of Battery Design Parameters
Authors: Liu Changhong , Liu Lin
Published: December 2015

Battery safety is crucial to electric vehicles (EVs). Battery degradation is closely related to battery safety. Degraded battery cells can cause potential safety issues. In order to improve battery safety, it is essential to reduce battery degradation. Battery degradation is mainly caused by side reactions, which can cause solid electrolyte interphase (SEI) layer growth. This paper aims to reduce degradation and improve battery safety by optimizing battery design parameters. The proposed framework develops a reduced-order electrochemical battery model to predict battery performance as well as SEI layer growth. Battery design parameters (i.e., electrode thickness, particle size, conductivity, and electrode porosity) are optimized to improve battery health and reduce battery capacity loss during cycling. The simulation results show that battery health has been improved from 46% to 68% and battery capacity loss has been reduced more than 22% during the first 100 cycles.
Mechanism of Gas Generation in Lithium Ion Batteries by Overdischarge
Authors: Hashimoto Mana , Yamashiro Midori , Ichihashi Toshinari , Toda Akio , Miyazaki Takashi , Fujieda Shinji
Published: December 2015

We found that over-discharging (ODC) LiMn2O4-based lithium ion batteries (LIBs) generates H2 gas. To investigate the origin of the H2 gas, we performed isotope-labeling of the electrolyte in addition to physical and chemical analyses. ODC proved to destroy SEI films on the anode surface. Also, the volume of the ODC-induced gas increased with charge/discharge cycles, which we attribute to a thicker SEI with H atoms after the cycles. Our isotope-labeling experiment shows that the H2 is not derived from the electrolytes; rather, H-impurities in the cathode active material seem to be the H2 source.
Impact of FEC Additive on SEI Structure Formed on a Carbon Negative Electrode Studied by HAXPES
Authors: Matsumoto Masashi , Sanada Takashi , Takao Naoki , Mogi Masato , Matsuda Tomoyuki , Ando Keisuke , Imamura Daichi , Imai Hideto
Published: December 2015

In order to understand the impact of fluoroethylene carbonate (FEC) additive on the improvement of the battery performance, such as the solid electrolyte interphase (SEI) stability, we investigated the structure, composition and dynamics for formation of the SEI formed on the carbon negative electrodes by using hard X-ray photoelectron spectroscopy (HAX-PES). The organic SEI species such as CH3CH2 OCO2-Li (LEC), (CH2O-CO2-Li)2 (LEDC), (CH2O-Li)2 and (CO2-Li)2 are the main reduction components of the SEI during discharge. The SEI layer continues to grow gradually as the number of the charge and discharge cycling increases. The stable SEI components, LiF and polymerization products, produced from FEC additives suppress the formation of the unstable SEI species such as LEC, LEDC, (CH2O-Li)2 and (CO2-Li)2 and the growth of the SEI with the charge and discharge cycle increase. This leads to the improvement of the battery performance such as the capacity retention and the overall impedance.
Degradation Behavior in Lithium Iron Phosphate Secondary Cells Under High Rate Pulsed Discharge
Authors: Wong Derek Nathan , Wetz David Alan , Heinzel John M , Mansour Azzam
Published: December 2015

Three 26650 LiFePO4 (LFP) cells cycled at 15C (40 A) under a pulsed discharge (PD) profile showed an abrupt drop in their 15C recharge capacity to 0 Ahr within a 60 cycle span. EIS at 100% state of charge (SOC) shows separation in the mid-frequency semi-circle indicating rapid increase of one electrochemical component’s impedance. XAS analyses on cycled cathodes show 85% retention of active material at the bulk level and almost 100% in the surface region. XPS on PD anodes show surface films that are rich in LiF which have high impedance compared to Li2CO3 rich films. LiF rich films on the anode cause the real impedance of the anodic half-cell to increase faster than the other, slowing the charge transfer kinetics of the battery dramatically. Results indicate the bipolar PD profile increases the rate of LiF deposition on the surface of the anode compared to high rate continuous cycling.
Dilatometric Study of the Electrochemical Intercalation of Bis(trifluoromethanesulfonyl) imide and Hexafluorophosphate Anions into Carbon-Based Positive Electrodes
Authors: Huesker Jessica Maria , Winter Martin , Placke Tobias
Published: December 2015

Anion intercalation into graphitic carbons typically occurs at high cathode potentials, i.e., above 4.5 V vs. Li/Li+, and is accompanied by a gallery height expansion and volume increase. The volume increase by accommodation of guest ions such as hexafluorophosphate (PF6
-) or bis(trifluoromethanesulfonyl) imide (TFSI-) is in the range of 130% to 140% according to a gallery height increase from 3.35 Å for pristine graphite to 7.74 to 7.99 Å for the graphite intercalation compounds. The gallery height expansion upon intercalation/de-intercalation in turn also results in an expansion/shrinkage behavior of the thickness of the composite graphite cathode which thus influences the mechanical integrity of the electrode and therefore the overall cycling stability. Furthermore, the type of polymeric binder will have a strong influence on the mechanical stability of the graphite-based cathodes. In this work, the expansion and shrinkage behavior of graphite positive electrodes related to PF6
- and TFSI- anion intercalation/de-intercalation into/from graphite was studied with electrochemical dilatometry technique. In particular, the reversibility of the expansion behavior as well as the maximum electrode thickness for the different anions/electrolytes is studied.
Constant-Phase Element Characteristics Caused by Resistivity Distribution in High Performance Anti-Corrosion Organic Coating Applied to Oil Storage Tank
Authors: Tokutake Koya , Nishi Haruki , Ito Daisuke , Okazaki Shinji , Serizawa Yukitaka
Published: December 2015

A constant-phase element (CPE) is often used for interpreting the coating impedance in correspondence with its physical property. To clarify the degradation mechanism of a high performance anti-corrosion organic coating on the internal bottom plate of an oil storage tank, the CPE characteristics in the coating impedance were investigated. Electrical impedance measurements were conducted on the actual oil storage tank immersed in a corrosive electrolyte solution for 16 years. By using the impedance equations related to CPE parameter values, the intrinsic coating capacitance (effective capacitance) was calculated. As a result, the appropriate effective capacitance could be obtained by the power-law model of the distribution of the coating resistivity according to a power-law along its thickness. In addition, this result indicates that the CPE behavior in the coating impedance is caused as the result from the electrolyte solution permeation into the coating.
Corrosion Behavior of 13Cr Casing Steel in Cement-Synthetic Pore Solution Exposed to High Pressure CO2 and H2S
Authors: Feng Ruishu , Beck Justin , Hall Derek M. , Buyuksagis Aysel , Ziomek-Moroz Margaret , Lvov Serguei N.
Published: December 2015

The electrochemical corrosion behavior of grade L-80, type 13Cr casing steel was investigated in cement-synthetic pore solution (CSPS) exposed to CO2 and H2S using in-situ electrochemical methods and ex-situ surface analyses at 85 and 200 °C, respectively. Total system pressure was 10 MPa. Corrosion rates increased significantly when the temperature increased from 85 to 200 °C. Limiting current behavior was observed for the anode reaction, while charge-transfer control was observed for the cathode reaction. Surface analyses revealed the presence of CaCO3 on the surface at both temperatures and FeCO3-like deposits at 200 °C.
Corrosion Protection of Friction Stir Spot Welds Produced in an AZ31B Magnesium Alloy
Authors: Savguira Yuri , Busef Sarah , North Tom H. , Thorpe Steven J.
Published: December 2015

Magnesium alloys can be joined by friction stir spot welding (FSSW) to achieve high mechanical integrity of the weld. Previous work done on AZ31B FSSW joints has shown that the welding process reduced their corrosion resistance, and resulted in localized attack around the weldment. The present work explores the possibility of a post-welding plasma electrolytic oxidation (PEO) treatment to minimize the negative effect of welding on the corrosion resistance of AZ31B. A mass loss testing approach was adopted to assess the corrosion resistance of PEO coated base metal and welded specimens. PEO coatings were found to drastically improve the corrosion resistance of welded and monolithic AZ31B, eliminating the localized corrosion associated with welding. Further improvement to the corrosion resistance of PEO coatings was achieved by adding polyethylene glycol to the electrolyte. The scanning reference electrode technique revealed that the breakdown mechanisms of the coating was governed by cathodic activation.
Microelectrochemical Investigation of Pit Initiation Site on Austenitic Cast Stainless Steel
Authors: Otake Asako , Muto Izumi , Chiba Aya , Sugawara Yu , Hara Nobuyoshi
Published: December 2015

A microelectrochemical technique was applied to ascertain the pit initiation behavior at the δ/γ-grain boundary of Type 304L austenitic cast stainless steel in 1 M NaCl solution. The size of electrode area was changed from ca. 0.01 mm2 (100 μm×100 μm) to ca. 100 mm2 (10 mm×10 mm). The density for pit initiation site of Type 304L cast stainless steel was estimated to be around 1 site/mm2. From anodic polarization, transmission electron microscopy, and energy-dispersive X-ray fluorescence analysis, P- and S-segregation was confirmed to be associated with the pit initiation at δ/γ-grain boundary. In addition to this, Si-segregation or Si-containing inclusion at the boundaries was thought to be a factor affecting the pit initiation at the δ/γ-grain boundary.
Electrodeposition of Zn Alloys with Cu and Sn from Citrate Electrolytes
Authors: Zahmi Salem , Podlaha Elizabeth J
Published: December 2015

The effect of Zn concentration on the electrodeposition of Zn, CuZn, SnZn, and CuSnZn was investigated using an upside down rotating disk electrode at pH 2. At a constant potential the alloys were both Cu- or Sn-rich at low Zn(II) ion electrolyte concentration and then jumped to Zn-rich at higher Zn (II) ion electrolyte concentration. The effect of codepositing Zn with Cu (or Sn) on the reaction order of Zn was studied by varying the Zn concentration in the electrolyte. A first order reaction order of Zn was found when Zn was singly deposited, but to capture the influence of the alloys the solid state activity was found to play an important role in the Tafel rate expression. When all three elements were present in the electrolyte at equimolar concentration the amount of Zn was between 18 - 44 wt %, in contrast to the upper and lower limits found with the binary alloys.
Copper Oxide Layers Obtained Via Anodization for Electrowetting on Dielectrics
Authors: Bernasconi Roberto , Bellantone Andrea , Liberale Francesco , Magagnin Luca
Published: December 2015

In the present work copper was anodized in alkaline environment and the resulting oxide was employed as dielectric layer together with a fluoropolymer to test the possibility of performing electrowetting. The influence of some process variables on the anodization was evaluated and the optimized conditions were employed to obtain adherent and compact oxide layers, formed of pure cuprite. After the application of the polymeric layer, the possibility to perform electrowetting on the samples was investigated. Promising results were obtained after saturation and hysteresis tests, demonstrating the possibility to perform changes of wettability on coupled copper oxide/fluoropolymer surfaces.
The Device-Perimeter Dependency in the Transient Current of a Metal-Insulator-Metal-Insulator-Semiconductor Capacitor with Anodic Oxide Films
Authors: Liao Chien-Shun , Hwu Jenn-Gwo
Published: December 2015

The fabrication and electrical characteristics of a capacitor with metal-insulator-metal-insulator-semiconductor structure, Al/Al2O3/ Al/AlSixOy/SiO2/Si(p), is demonstrated. Both the SiO2 and Al2O3 layers were grown by anodic oxidation at room temperature. There are three different pattern sizes of the fabricated devices. The transient currents of the devices after applying voltage pulse stresses were investigated. After applying positive voltage stress, negative transient current could be read, and vice versa. It was found that the positive read currents of the devices are proportional to device perimeters, and the negative read currents are independent of the device areas. The possible contributing factors of the results are fringing field effect and the change of stored charge in the AlSixOy layer.
Genetically Engineered Cyanobacteria Enhances Photocurrent Generation in Photo-bioelectrochemical Cell
Authors: Sekar Narendran , Ramasamy Ramaraja P.
Published: December 2015

Cyanobacteria exhibit light dependent exoelectrogenic activity in photo-bioelectrochemical cells (PBEC) generating substantial photocurrent. However compared to the other competing technologies such as photovoltaics, the photocurrent generated by cyanobacteria is lower and is not suitable yet to become a viable alternative technology. Initiatives to understand and enhance the exoelectrogenicity of cyanobacteria are crucial to resolve this caveat. In this perspective, a cyanobacterium named Synechococcus elongatus PCC7942 was genetically engineered to express a heterologous protein called outer membrane cytochrome S for enhancing its exoelectrogenicity. The genetically engineered cyanobacteria exhibited nearly 9 fold higher photocurrent generation than the corresponding wild-type cyanobacterium. Further, power density generated by the genetically engineered cyanobacteria in a rudimentary PBEC was found to be five times higher than that generated by wild-type. The multidisciplinary research work presented here highlights the scope for enhancing photocurrent generation by cyanobacteria thereby benefiting faster advancement of PBEC technology.
Dye-Sensitized Solar Cell with Electrophoretic Deposited Photocatalytic Carbon Nanotube Counter Electrode: Nanotube Density and Cell Performance
Authors: Das Suprem , Logsdon Seth , Caneff Drew , Kinser Robert , Hu Shan
Published: December 2015

Among the emerging solar cell technologies, dye-sensitized solar cell (DSSC) is so far most promising in terms of its efficiency, stability and reliability in air compared to organic photovoltaics (OPV) and Quantum dot solar cells. While platinum is used as a primary catalyst material in the counter electrode of a conventional DSSC, nanostructured alternatives could potentially further reduce the cost of these emerging solar cells and enhance the functionalities in flexible platform. In this work, we present the possibility of electrophoretic carbon nanotubes (CNTs) thin film as catalytic counter electrode in DSSC without compromising its efficiency. These electrodes can decrease both material and fabrication cost of DSSC while providing comparable performance with platinum counter electrode. The CNT thin film also has enhanced mechanical flexibility and paves the pathway towards flexible DSSC.
Fabrication of Low-Invasive Patch Glucose Sensors
Authors: Li Jiang , Hiura Kentaro , Yasuzawa Mikito , Fuchiwaki Yusuke
Published: December 2015

A low invasive glucose sensor, which has sensing region at the tip of a fine tapered electrode, was developed for continuous glucose monitoring. Platinum-Iridium alloy electrode was settled at the middle of tapered PEEK tube and was employed as sensing electrode. Electrodeposition of glucose oxidase in the presence of surfactant, Triton X-100, was performed for high-density enzyme immobilization, and was followed by the electropolymerization of o-phenylenediamine for the formation of functional entrapping and permselective polymer membrane. Amperometric responses of the prepared sensors to glucose were measured at a potential of 0.60 V (vs. Ag/AgCl). The sensor showed the sensitivity of 5.387 mA/cm2 mM, r2=0.992, and a good linear range from up to 21.6 mM glucose.