bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation of the Variations of Early Flame Development in a Spark-Ignition Direct-Injection Optical Engine
Authors: Hung David L. S. , Chen Hao , Xu Min , Yang Jie , Zhuang Hanyang
Published: March 2014

Experiments under two intake air swirl levels (swirl ratios of 0.55 and 5.68) were conducted in order to investigate the early flame development of combustion in a single-cylinder spark-ignition direct-injection engine. The engine was equipped with a quartz insert in the piston, which provided an optical access to its cylinder through the piston. The crank angle resolved combustion images through the piston window and in-cylinder pressure measurements of 250 cycles were simultaneously recorded for both swirl levels at a specified engine speed and low load condition. The early development, size, and spatial characteristics extracted from the flame images were analyzed as a function of crank angle degrees after the ignition. The experimental results revealed that the early flame development was strongly influenced by the highly directed swirl motion of intake-air into the combustion cylinder. The location of the start of the flame kernel relative to the spark plug position also changed intermittently at different swirl levels. While the structure of the early flame was found to be similar for both swirl levels, the starting location of the flame showed a vast difference in how the flame progressed. In general, the flame kernel was formed two crank-angle degrees after spark timing for the high swirl level, which was four crank-angle degrees earlier than that of the low swirl case. For the low swirl flow, the early combustion showed more cycle-to-cycle variation in terms of both the flame size and centroid location. It was quantitatively shown that increasing the swirl ratio from 0.55 to 5.68 could reduce the cycle-to-cycle variation of the early flame structure, resulting in about three to four crank-angle degrees advance of the peak pressure location and a 1% improvement for the coefficient of variation (COV) of the indicated mean effective pressure (IMEP).
MR‐based motion correction for PET imaging using wired active MR microcoils in simultaneous PET‐MR: Phantom study
Authors: Huang Chuan , Ackerman Jerome L. , Petibon Yoann , Brady Thomas J. , El Fakhri Georges , Ouyang Jinsong
Published: March 2014

Purpose:

Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction.

Methods:

Several wired active MR microcoils and a dedicated MR coil‐tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic18F‐filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list‐mode and MR tracking data were acquired simultaneously on a PET‐MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard.

Results:

Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R2 = 0.978 ± 0.007 (0.588 ± 0.010, respectively).

Conclusions:

Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast.
Long‐term stability and mechanical characteristics of kV digital imaging system for proton radiotherapy
Authors: Zhu Mingyao , Botticello Thomas , Lu Hsiao‐Ming , Winey Brian
Published: March 2014

Purpose:

To quantitatively evaluate the long‐term image panel positioning stability and gantry angle dependence for gantry‐mounted kV imaging systems.

Methods:

For patient setup digital imaging systems in isocentric rotating proton beam delivery facilities, physical crosshairs are commonly inserted into the snout to define the kV x‐ray beam isocenter. Utilizing an automatic detection algorithm, the authors analyzed the crosshair center positions in 2744 patient setup kV images acquired with the four imagers in two treatment rooms from January 2012 to January 2013. The crosshair position was used as a surrogate for imaging panel position, and its long‐term stability at the four cardinal angles and the panel flex dependency on gantry angle was investigated.

Results:

The standard deviation of the panel position distributions was within 0.32 mm (with the range of variation less than ± 1.4 mm) in both the X‐Z plane and Y direction. The mean panel inplane rotations were not more than 0.51° for the four panels at the cardinal angles, with standard deviations ≤0.26°. The panel position variations with gantry rotation due to gravity (flex) were within ±4 mm, and were panel‐specific.

Conclusions:

The authors demonstrated that the kV image panel positions in our proton treatment system were highly reproducible at the cardinal angles over 13 months and also that the panel positions can be correlated to gantry angles. This result indicates that the kV image panel positions are stable over time; the amount of panel sag is predictable during gantry rotation and the physical crosshair for kV imaging may eventually be removed, with the imaging beam isocenter position routinely verified by adequate quality assurance procedures and measurements.
Fossilized Nuclei and Chromosomes Reveal 180 Million Years of Genomic Stasis in Royal Ferns
Authors: Bomfleur Benjamin , McLoughlin Stephen , Vajda Vivi
Published: March 2014

Cytologically Informative Fossils

Fossilization processes tend to destroy fine-cell structure but, exceptionally,

Bomfleur
et al.

(p.
1376
) have found examples of fossil ferns from the Jurassic in which subcellular structures, including organelles such as nuclei and chromosomes, are well-preserved. Comparative and quantative analyses show that these cells closely resemble the fossil nuclei of extant cinnamon ferns,
Osmundastrum cinnamomea
, which indicates that this group of ferns has remained virtually unchanged for 180 million years.
To Connect More Equitably
Social Networks and Popular Understanding of Science and Health
Sharing Disparities

by Brian G. Southwell

Johns Hopkins University Press, Baltimore, and RTI Press, Research Triangle Park, NC, 2013. 145 pp. Paper, $24.95, £16. ISBN 9781421413242.
Authors: Brennan Emily
Published: March 2014

Research on the ways people learn and share information about health and science, Southwell argues, suggests that systematic reliance on social networks will increase inequity.
Dueling Visions for Agency
Authors: Mervis Jeffrey
Published: March 2014

The Democratic alternative to the Republican bill would encourage the National Science Foundation to support more of the same high-quality research it now funds.
A War Within a War
Authors: Roberts Leslie
Published: March 2014

Fighting a major polio outbreak in the midst of Syria's bitter civil war is a test of commitment—and diplomacy.
Humans and Ferrets with Prior H1N1 Influenza Virus Infections Do Not Exhibit Evidence of Original Antigenic Sin after Infection or Vaccination with the 2009 Pandemic H1N1 Influenza Virus
Authors: O'Donnell Christopher D. , Wright Amber , Vogel Leatrice , Boonnak Kobporn , Treanor John J. , Subbarao Kanta
Published: March 2014

The hypothesis of original antigenic sin (OAS) states that the imprint established by an individual's first influenza virus infection governs the antibody response thereafter. Subsequent influenza virus infection results in an antibody response against the original infecting virus and an impaired immune response against the newer influenza virus. The purpose of our study was to seek evidence of OAS after infection or vaccination with the 2009 pandemic H1N1 (2009 pH1N1) virus in ferrets and humans previously infected with H1N1 viruses with various antigenic distances from the 2009 pH1N1 virus, including viruses from 1935 through 1999. In ferrets, seasonal H1N1 priming did not diminish the antibody response to infection or vaccination with the 2009 pH1N1 virus, nor did it diminish the T-cell response, indicating the absence of OAS in seasonal H1N1 virus-primed ferrets. Analysis of paired samples of human serum taken before and after vaccination with a monovalent inactivated 2009 pH1N1 vaccine showed a significantly greater-fold rise in the titer of antibody against the 2009 pH1N1 virus than against H1N1 viruses that circulated during the childhood of each subject. Thus, prior experience with H1N1 viruses did not result in an impairment of the antibody response against the 2009 pH1N1 vaccine. Our data from ferrets and humans suggest that prior exposure to H1N1 viruses did not impair the immune response against the 2009 pH1N1 virus.
Controlled Clinical Comparison of New Pediatric Medium with Adsorbent Polymeric Beads (PF Plus) versus Charcoal-Containing PF Medium in the BacT/Alert Blood Culture System
Authors: Doern Christopher D. , Mirrett Stanley , Halstead Diane , Abid Joan , Okada Pamela , Reller L. Barth
Published: March 2014

We conducted a controlled clinical comparison of PF Plus, the new pediatric medium with adsorbent polymeric beads, versus the charcoal-containing PF medium in the BacT/Alert blood culture system. A total of 2,381 pediatric cultures were enrolled, and 1,703 (71.5%) were deemed to be compliant and acceptable for analysis. Seventy-two cultures (4.2%) had a positive result with 80 clinically significant microorganisms. The results showed that the PF Plus medium yielded more clinically significant microorganisms than the BacT/Alert system (
P
< 0.05). In addition, the PF Plus bottle yielded positive results an average of 5.0 h earlier than the PF bottle for compliant clinically significant cultures (18.3 h versus 23.2 h,
P
= 0.004). PF Plus is an improved medium for detecting microorganisms that cause pediatric bloodstream infections.
Human Cathelicidin LL-37 Resistance and Increased Daptomycin MIC in Methicillin-Resistant Staphylococcus aureus Strain USA600 (ST45) Are Associated with Increased Mortality in a Hospital Setting
Authors: Sakoulas George , Guram Kripa , Reyes Katherine , Nizet Victor , Zervos Marcus
Published: March 2014

Bacteremia caused by methicillin-resistant
Staphylococcus aureus
(MRSA) USA600 has been associated with increased patient mortality. We found that USA600 MRSA exhibited significantly increased resistance to human cathelicidin LL-37 killing and daptomycin MIC creep compared to non-USA600 MRSA. Virulent health care-associated MRSA strains may coevolve innate host defense peptide and antibiotic resistances.
Multilocus Sequence Typing of Serially Collected Isolates of Cryptococcus from HIV-Infected Patients in South Africa
Authors: Van Wyk Marelize , Govender Nelesh P. , Mitchell Thomas G. , Litvintseva Anastasia P.
Published: March 2014

Patients with cryptococcal meningitis in sub-Saharan Africa frequently relapse following treatment. The natural history and etiology of these recurrent episodes warrant investigation. Here, we used multilocus sequence typing (MLST) to compare the molecular genotypes of strains of
Cryptococcus neoformans
and
Cryptococcus gattii
isolated from serial episodes of cryptococcal meningitis that were separated by at least 110 days. The most common MLST genotypes among the isolates were the dominant global clinical genotypes (M5 and M4) of molecular type VNI, as well as the VNI genotypes apparently restricted to southern Africa. In addition, there was considerable genetic diversity among these South African isolates, as 15% of the patients had unique genotypes. Eleven percent of the patients were reinfected with a genetically different strain following their initial diagnosis and treatment. However, the majority of serial episodes (89%) were caused by strains with the same genotype as the original strain. These results indicate that serial episodes of cryptococcosis in South Africa are frequently associated with persistence or relapse of the original infection. Using a reference broth microdilution method, we found that the serial isolates of 11% of the patients infected with strains of
C. neoformans
var.
grubii
with identical genotypes exhibited ≥4-fold increases in the MICs to fluconazole. Therefore, these recurrent episodes may have been precipitated by inadequate induction or consolidation of antifungal treatment and occasionally may have been due to increased resistance to fluconazole, which may have developed during the chronic infection.
Mycobacterium massiliense Bacteremia as a Consequence of M. massiliense Pneumonia in a Patient with Acute Lymphoblastic Leukemia
Authors: Kim Jaewook , Park Jeong Su , Jeong Yun Sil , Kim Dae-Young , Sung Heungsup , Kim Mi-Na
Published: March 2014

A 52-year-old woman with relapsed acute lymphoblastic leukemia was diagnosed with
Mycobacterium massiliense
pneumonia after 4 months of chemotherapy. She developed
M. massiliense
bacteremia 1 month later. This is the first report of a proven case of
M. massiliense
bacteremia as a consequence of
M. massiliense
pneumonia.
Within-Host Evolution Results in Antigenically Distinct GII.4 Noroviruses
Authors: Debbink Kari , Lindesmith Lisa C. , Ferris Martin T. , Swanstrom Jesica , Beltramello Martina , Corti Davide , Lanzavecchia Antonio , Baric Ralph S.
Published: March 2014

Genogroup II, genotype 4 (GII.4) noroviruses are known to rapidly evolve, with the emergence of a new primary strain every 2 to 4 years as herd immunity to the previously circulating strain is overcome. Because viral genetic diversity is higher in chronic than in acute infection, chronically infected immunocompromised people have been hypothesized to be a potential source for new epidemic GII.4 strains. However, while some capsid protein residues are under positive selection and undergo patterned changes in sequence variation over time, the relationships between genetic variation and antigenic variation remains unknown. Based on previously published GII.4 strains from a chronically infected individual, we synthetically reconstructed virus-like particles (VLPs) representing early and late isolates from a small-bowel transplant patient chronically infected with norovirus, as well as the parental GII.4-2006b strain. We demonstrate that intrahost GII.4 evolution results in the emergence of antigenically distinct strains over time, comparable to the variation noted between the chronologically predominant GII.4 strains GII.4-2006b and GII.4-2009. Our data suggest that in some individuals the evolution that occurs during a chronic norovirus infection overlaps with changing antigenic epitopes that are associated with successive outbreak strains and may select for isolates that are potentially able to escape herd immunity from earlier isolates.

IMPORTANCE
Noroviruses are agents of gastrointestinal illness, infecting an estimated 21 million people per year in the United States alone. In healthy individuals, symptomatic infection typically resolves within 24 to 48 h. However, symptoms may persist for years in immunocompromised individuals, and development of successful treatments for these patients is a continuing challenge. This work is relevant to the design of successful norovirus therapeutics for chronically infected patients; provides support for previous assertions that chronically infected individuals may serve as reservoirs for new, antigenically unique emergent strains; and furthers our understanding of genogroup II, genotype 4 (GII.4) norovirus immune-driven molecular evolution.
Antibody-Mediated Immune Control of a Retrovirus Does Not Require the Microbiota
Authors: Wilks Jessica , Beilinson Helen , Theriault Betty , Chervonsky Alexander , Golovkina Tatyana
Published: March 2014

Commensal microbes are often required to control viral infection by facilitating host immune defenses. However, we found that this does not hold true for retroviral infection. We report that retrovirus-resistant mice control the pathogen with virus-neutralizing antibodies independently of commensal microbiota. This is in contrast to orthomyxoviruses and arenaviruses, where resistance is ablated in animals depleted of microbiota. Clearly, when it comes to antiviral immunity, the role of the microbiota cannot be generalized.
Protein Interferon-Stimulated Gene 15 Conjugation Delays but Does Not Overcome Coronavirus Proliferation in a Model of Fulminant Hepatitis
Authors: Ma Xue-Zhong , Bartczak Agata , Zhang Jianhua , He Wei , Shalev Itay , Smil David , Chen Limin , Phillips Jim , Feld Jordan J. , Selzner Nazia , Levy Gary , McGilvray Ian
Published: March 2014

Coronaviruses express a deubiquitinating protein, the papain-like protease-2 (PLP2), that removes both ubiquitin and the ubiquitin-like interferon (IFN)-stimulated gene 15 (ISG15) protein from target proteins. ISG15 has antiviral activity against a number of viruses; therefore, we examined the effect of ISG15 conjugation (ISGylation) in a model of acute viral hepatitis induced by the murine hepatitis virus strain 3 (MHV-3) coronavirus. Mice deficient in the ISG15 deconjugating enzyme, ubiquitin-specific peptidase-18 (USP18), accumulate high levels of ISG15-conjugated proteins and are hypersensitive to type I IFN. Infecting USP18
−/−
mice with MHV-3 resulted in extended survival (8 ± 1.2 versus 4 days) and in improved liver histology, a decreased inflammatory response, and viral titers 1 to 2 logs lower than in USP18
+/+
mice. The suppression of viral replication was not due to increased IFN since infected USP18
−/−
mice had neither increased hepatic IFN-α, -β, or -γ mRNA nor circulating protein. Instead, delayed MHV-3 replication coincided with high levels of cellular ISGylation. Decreasing ISGylation by knockdown of the ISG15 E1 enzyme, Ube1L, in primary USP18
+/+
and USP18
−/−
hepatocytes led to increased MHV-3 replication. Both
in vitro
and
in vivo
, increasing MHV-3 titers were coincident with increased PLP2 mRNA and decreased ISGylation over the course of infection. The pharmacologic inhibition of the PLP2 enzyme
in vitro
led to decreased MHV-3 replication. Overall, these results demonstrate the antiviral effect of ISGylation in an
in vivo
model of coronavirus-induced mouse hepatitis and illustrate that PLP2 manipulates the host innate immune response through the ISG15/USP18 pathway.

IMPORTANCE
There have been a number of serious worldwide pandemics due to widespread infections by coronavirus. This virus (in its many forms) is difficult to treat, in part because it is very good at finding “holes” in the way that the host (the infected individual) tries to control and eliminate the virus. In this study, we demonstrate that an important host viral defense—the ISG15 pathway—is only partially effective in controlling severe coronavirus infection. Activation of the pathway is very good at suppressing viral production, but over time the virus overwhelms the host response and the effects of the ISG15 pathway. These data provide insight into host-virus interactions during coronavirus infection and suggest that the ISG15 pathway is a reasonable target for controlling severe coronavirus infection although the best treatment will likely involve multiple pathways and targets.
Giant coronary aneurysm presenting as a cardiac mass on transthoracic echocardiogram
Authors: Mutha Vivek , Asrar ul Haq Muhammad , Anavekar Nagesh S , Barlis Peter
Published: March 2014

A 69-year-old man with a history of ischaemic heart disease and previous stent implantation in the right coronary artery (RCA) was found to have a large well-encapsulated mass attached to the right atrium on a routine transthoracic echocardiogram. Subsequent investigations including transoesophageal echocardiography and CT coronary angiogram suggested an RCA aneurysm formation in relation to the prior stented segment, further confirming on coronary angiogram a large ectatic vessel with a giant aneurysm measuring 2.4×2.7 cm. Giant coronary artery aneurysms are rare and here we present interesting images of a case initially picked up on transthoracic echocardiography.
Iliac artery pseudoaneurysm presenting as a paravertebral collection: a potentially fatal mimic
Authors: Taif Sawsan , Alrawi Asif , Al-Kalbani Jokha
Published: March 2014

Pseudoaneurysms of the iliac arteries are extremely rare and can complicate trauma, surgical or interventional procedures. We report a case of pseudoaneurysm arising from the common iliac artery in a 37-year-old man which presented as a paravertebral collection. As the MRI appearance mimicked spondylodiscitis, a CT guided biopsy was requested. However, the presence of a signal void centre guided the radiologist to the correct diagnosis, which was later confirmed on contrast-enhanced CT. Following unsuccessful treatment by percutaneous thrombin injection, open surgery was performed which revealed a leaking aneurysm associated with a huge retroperitoneal haematoma. We present this case to highlight the importance of considering vascular lesions as a differential diagnosis in patients presenting with a mass or pressure symptoms in different parts of the body. Misdiagnosing such lesions as soft tissue tumours or abscesses may result in serious consequences.
Acute shortening and angulation for limb salvage in a paediatric patient with a high-energy blast injury
Authors: Pikkel Yoav Yechezkel , Wilson Jessica Jeanne , Kassis Shokrey , Lerner Alexander
Published: March 2014

We present the case of an 8-year-old girl casualty of the Syrian conflict who arrived with open fractures of the right tibia and fibula with extensive bone and soft tissue loss as well as an open fracture of the left calcaneus as the result of a high-energy blast injury. She was successfully treated with repeated debridement procedures, external fixation with acute temporary shortening and angulation of the right leg and skin grafting to both lower limbs.
Wernicke's encephalopathy in a patient with gastric carcinoma: a diagnosis not to miss
Authors: Udyavara Kudru Chandrashekar , Kaniyoor Nagiri Shivashankara , Rao Sandeep
Published: March 2014

We describe a case of a patient who presented with a 20-day history of vomiting, generalised weakness and loss of appetite and a 2-day history of altered sensorium. On examination, he was grossly emaciated and there were no palpable lymph nodes. Central nervous system examination revealed nystagmus with bilateral lateral recti palsy and abdominal examination showed mild hepatomegaly. MRI of the brain showed bilateral and symmetrical hypertense signal changes in T2-weighted and fluid-attenuated inversion recovery sequences with diffusion restriction in the paramedian ventromedial thalamus. These findings were compatible with Wernicke's encephalopathy. He was started on thiamine supplementation with which neurological signs improved. An ultrasound of the abdomen showed mild hepatomegaly with multiple hyperechoic lesions and wall thickening of the pyloric antrum. Upper gastroduodenoscopy showed ulcerative lesions involving the antrum, pylorus and duodenum. Biopsy revealed moderately differentiated adenocarcinoma. The patient underwent palliative gastrojejunostomy and was clinically better at discharge. It is important to consider Wernicke encephalopathy in patients with gastric cancer who have acute neurological symptoms.
Practical experience with the implementation of an athlete's biological profile in athletics, cycling, football and swimming
Authors: Zorzoli M , Pipe A , Garnier P Y , Vouillamoz M , Dvorak J
Published: March 2014

The introduction of the athlete's biological passport (ABP) has been a milestone in the fight against doping. The ABP is a collection of measurements of different biological parameters influenced by the administration of doping agents through the time and for each athlete. Two different modules have been developed and validated so far: the haematological module, which aims to identify enhancement of oxygen transport, including use of erythropoiesis-stimulating agents and any form of blood transfusion or manipulation, which became effective in 2010; and the steroidal module, which intends to detect the use of endogenous anabolic androgenic steroids when administered exogenously and other anabolic agents, which was introduced in 2014. Prior to the implementation of the haematological module, it is important to define an athlete’s testing pool on whom to collect blood and/or urine in-competition and out-of-competition (for the steroidal module, this is irrelevant because all collected urine samples will be subjected to analysis for the steroidal variables) and to be compliant with the strict requirements of the World Anti-Doping Agency ABP Operating Guidelines. The established individual profile can be used either to target traditional antidoping tests (recombinant erythropoietins, or homologous blood transfusion tests for the haematological module; isotope ratio mass spectrometry (IRMS) for the steroidal module) or to support an antidoping rule violation due to the use of a forbidden substance or method. In this article, we present the experience of four major International Federations which have implemented an ABP programme, focusing on the haematological module. They constitute examples which could be followed by other antidoping organisations wishing to introduce this new, efficient and innovative antidoping tool.
The mission continues…
Authors: Gamble Luke
Published: March 2014

In September last year, more than 400 volunteers from 14 different countries set out to vaccinate 50,000 dogs in India against rabies, as part of a project that ultimately aims to eliminate the disease. Here, Luke Gamble, the driving force behind Mission Rabies, discusses why such initiatives are needed, how the first mass vaccination campaign went and what the goals are for the future
Solution properties of metal ion complexes formed with the antiviral and cytostatic nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]-2-amino-6-dimethylaminopurine (PME2A6DMAP)
Authors: Gómez-Coca Raquel B. , Sigel Astrid , Operschall Bert P. , Holý Antonín , Sigel Helmut
Published: March 2014

The acidity constants of protonated 9-[2-(phosphonomethoxy)ethyl]-2-amino-6-dimethylaminopurine (H3(PME2A6DMAP)+) are considered, and the stability constants of the M(H;PME2A6DMAP)+ and M(PME2A6DMAP) complexes (M2+ = Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, or Cd2+) were measured by potentiometric pH titrations in aqueous solution (25 °C; I = 0.1 mol/L, NaNO3). In the M(H;PME2A6DMAP)+ species, H+ and M2+ (mainly outersphere) are at the phosphonate group; this is relevant for phosphoryl-diester bridges in nucleic acids because, in the present system, there is no indication for a M2+–purine binding. This contrasts, for example, with the complexes formed by 9-[2-(phosphonomethoxy)ethyl]adenine, M(H;PMEA)+, where M2+ is mainly situated at the adenine residue. Application of log [Formula: see text] vs. [Formula: see text] plots for simple phosph(on)ate ligands, R–PO32− (R being a residue that does not affect M2+ binding), proves that all M(PME2A6DMAP) complexes have larger stabilities than what would be expected for a M2+–phosphonate coordination. Comparisons with M(PME–R) complexes, where R is a noncoordinating residue of the (phosphonomethoxy)ethane chain, allow one to conclude that the increased stability is due to the formation of five-membered chelates involving the ether–oxygen of the –CH2–O–CH2–PO32− residue: the percentages of formation of these M(PME2A6DMAP)cl/O chelates, which occur in intramolecular equilibria, vary between 20% (Sr2+, Ba2+) and 50% (Zn2+, Cd2+), up to a maximum of 67% (Cu2+). Any M2+ interaction with N3 or N7 of the purine moiety, as in the parent M(PMEA) complexes, is suppressed by the (C2)NH2 and (C6)N(CH3)2 substituents. This observation, together with the previously determined stacking properties, offers an explanation why PME2A6DMAP2– has remarkable therapeutic effects.
Complete periodic adaptive antisynchronization of memristor-based neural networks with mixed time-varying delays
Authors: Wu Huaiqin , Li Ruoxia , Ding Sanbo , Zhang Xiaowei , Yao Rong
Published: March 2014

This paper is concerned with the complete periodic antisynchronization issue of memristor-based neural networks with mixed time-varying delays. Under the framework of Filippov solutions of the differential equations with discontinuous right-hand side, based on Mawhin-like coincidence theorem in set-valued analysis theory, the proof of the existence of periodic solution is presented. By applying the Lyapunov–Krasovskii functional approach, adaptive controller is designed and unknown control parameters of the slave system are determined by adaptive laws, and the complete periodic adaptive antisynchronization condition is addressed to ensure the slave system global antisynchronization with the master system. An illustrative example is given to demonstrate the effectiveness of the obtained results.
Photophysical characteristics of two novel coumarin derivatives: Experimental and theoretical estimation of dipole moments using the solvatochromic shift method
Authors: Patil Shivaram N. , Sanningannavar F.M. , Navati B.S. , Patil N.R. , Kusanur R.A. , Melavanki R.M.
Published: March 2014

The exited state (μe) dipole moment of a molecule is an important parameter, which gives information about electronic and geometrical structure of the molecule in the short-lived state. We have experimentally estimated the exited state (μe) dipole moment of two novel coumarin derivatives, namely, diethyl 2-acetamido-2-((6-methyl-2-oxo-2H-chromen-4-yl) methyl) malamute (DAM) and 5,6-Benzo-3-[1-(4,5-dicarbomethoxy-1,2,3-triazoloacetyl)] coumarin (5BDTC) by three methods, namely, Lippert’s, Bakhshiev’s, and Kawski–Chamma–Viallet’s. In the Solvatochromic shift method, spectral shift is due to internal excitation of the molecule. We have recorded absorption and emission spectra of the above two novel coumarin derivatives at room temperature using solvents of different polarities. The geometry of the molecules were fully optimized and the ground state dipole moment (μg) were also calculated theoretically by Gaussian 03 software using B3LYP/6-31g* level of theory. The excited state dipole moment was calculated using CIS/6-31G* level of theory. The μg and μe were calculated using the solvatochromic shift method and μe was also determined in combination with μg. It was observed that μe were greater than those of μg, indicating a substantial redistribution of the π-electron densities in a more polar excited state for this coumarin. Further, the changes in dipole moment (Δμ) were calculated both from the solvatochromic shift method and on the basis of microscopic empirical solvent polarity ([Formula: see text]) and the values are compared.
Effects of pyruvate on the energetics of rat ventricles stunned by ischemia–reperfusion
Authors: Bonazzola Patricia , Ragone María Inés , Consolini Alicia E.
Published: March 2014

Pyruvate (Pyr) was proposed as an additive to cold high-K+–low-Ca2+cardioplegia (CPG) to protect the heart during surgery. We explored whether Pyr and CPG would work synergistically to protect rat hearts from stunning during ischemia–reperfusion (I/R). We measured the heat release and contractility of perfused ventricles during I/R, and the cytosolic and mitochondrial [Ca2+] in cardiomyocytes by confocal microscopy. We found that under cold-CPG (30 °C), 10 mmol·L−1Pyr reduced the post-ischemic contractile recovery (PICR) as well as muscle economy, when added either before ischemia or during I/R, which was reversed by blockade of UCam. In noncardioplegic hearts, Pyr was cardioprotective when it was present during I/R, more so at 37 °C than at 30 °C, with improved economy. In cardiomyocytes, the addition of Pyr to CPG slightly increased the mitochondrial [Ca2+] but decreased cytosolic [Ca2+]. The results suggest that Pyr only protects hearts from stunning when present before ischemia and during reperfusion, and that it dampens the cardioprotective properties of CPG. The mechanisms underlying such different behavior depend on the dynamic balance between Pyr stimulation of the energetic state and mitochondrial Ca2+uptake. Our results support the use of Pyr in stunned hearts, but not in cold high-K+cardioplegia.
A long-term study reveals multiple reproductive behavior strategies among territorial adult male Steller sea lions (Eumetopias jubatus)
Authors: Parker Pamela , Maniscalco John M.
Published: March 2014

We conducted a long-term study to assess how tenure and territorial behaviors influence reproductive success among male Steller sea lions (Eumetopias jubatus (Schreber, 1776)). Copulations by males (n = 44) that maintained territories on a rookery in the Gulf of Alaska from 2001 to 2009 were observed using a remote video system. Approximately half of postpartum females copulated with a male in a different territory from where they gave birth. Nearly two-thirds of territorial males with known tenure were unsuccessful in copulating during their first year. Number of copulations for territorial males increased from acquisition year to year 2 with no change in subsequent years. Cluster analysis of tenure and territorial tactic variables for 15 males with observed lifetime reproductive success was used to describe multiple reproductive strategies. Characteristics of the two most successful strategies were the following: (i) males typically copulated in their first year, retained the same territories for 3–5 years, and occupied centrally located coastal territories where the highest percentage of females gave birth and (ii) males did not copulate until at least their third year and occupied peripheral territories with fewer births for a longer tenure of 7–8 years. Results indicated that lifetime reproductive success was not achieved solely by time on the breeding area; rather, it was achieved from a combination of tenure and territorial tactics.
A generic target for species recovery
Authors: Hutchings Jeffrey A. , Kuparinen Anna
Published: March 2014

Recovery targets for threatened species are typically developed on a species- or population-specific basis. Such narrow taxonomic specificity stands in contrast with widely applied species-independent metrics of conservation status. Here, we propose a generic protocol that can be used to specify broadly applicable targets intended to recover the ecological and evolutionary functionality of threatened species. The method is based on basic density-dependent population dynamics, draws on first principles related to population growth, and explicitly incorporates habitat by accounting for changes in carrying capacity. It offers a consistently applied, methodologically transparent, and predictable biological benchmark for recovery purposes. The benefits of a generic method for articulating recovery targets, particularly from a policy- and statute-implementation perspective, are substantive.
Computing the Cassels–Tate pairing on the 3-Selmer group of an elliptic curve
Authors: Fisher Tom , Newton Rachel
Published: March 2014

We extend the method of Cassels for computing the Cassels–Tate pairing on the 2-Selmer group of an elliptic curve, to the case of 3-Selmer groups. This requires significant modifications to both the local and global parts of the calculation. Our method is practical in sufficiently small examples, and can be used to improve the upper bound for the rank of an elliptic curve obtained by 3-descent.
Hecke operators on certain subspaces of integral weight modular forms
Authors: Boylan Matthew , Brown Kenny
Published: March 2014

Recent works of F. G. Garvan ([Congruences for Andrews' smallest parts partition function and new congruences for Dyson's rank, Int. J. Number Theory6(12) (2010) 281–309; MR2646759 (2011j:05032)]) and Y. Yang ([Congruences of the partition function, Int. Math. Res. Not.2011(14) (2011) 3261–3288; MR2817679 (2012e:11177)] and [Modular forms for half-integral weights on SL 2(ℤ), to appear in Nagoya Math. J.]) concern a certain family of half-integral weight Hecke-invariant subspaces which arise as multiples of fixed odd powers of the Dedekind eta-function multiplied by SL 2(ℤ)-forms of fixed weight. In this paper, we study the image of Hecke operators on subspaces which arise as multiples of fixed even powers of eta multiplied by SL 2(ℤ)-forms of fixed weight.
EFFECT OF SUBSTITUENTS IN THE IMIDAZOLIUM RING ON THE PERFORMANCE OF SOLID-STATE DYE-SENSITIZED SOLAR CELLS
Authors: LI JUAN , LV KAI , SUN HONG , WANG ZHONG-SHENG
Published: March 2014

Three solid-state imidazolium iodides have been designed and synthesized for use as all-solid-state electrolytes in solid-state dye-sensitized solar cells (ssDSSCs). The effect of substituents in the imidazolium ring on the ionic conductivity and solar cell performance of ssDSSCs has been investigated. As compared to the methyl-ethyl-substituted imidazolium iodide, replacement of one alkyl group (the methyl group) with an ester group increases the ionic conductivity and solar cell performance significantly, and further replacement of the other alkyl group (the ethyl group) with a hydroxyethyl group further increases the ionic conductivity and solar cell performance significantly. A power conversion efficiency of 7.45% has been achieved under the irradiation of simulated AM1.5G solar light (100 mW cm-2) with the ssDSSC using the hydroxyethyl and ester co-functionalized imidazolium iodide based solid-state electrolyte and a metal-free organic dye sensitizer.
TiO2 SUB-MICROSPHERES AS A BI-FUNCTIONAL SCATTERING LAYER FOR HIGH-PERFORMANCE DYE-SENSITIZED SOLAR CELLS
Authors: DING YONG , MO LI'E , TAO LI , MA YANMEI , HU LINHUA , JIANG LING , LI ZHAOQIAN , ZHANG CHANGNENG , ZHANG BING , YAO JIANXI , DAI SONGYUAN
Published: March 2014

The sub-microspheres play multiple roles in enhancing dye adsorption and light-scattering to improve the performance of dye-sensitized solar cells (DSSCs). In this work, the well-defined TiO 2 sub-microspheres with anatase granular-like nanocrystals are prepared in high yield by combining hydrolytic process with solvothermal treatment. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results indicated that plenty of rhombic nanoparticles with ~ 18 nm diameter having mutual contacts to neighboring nanoparticles were densely self-assembled into sub-microspheres, and abundant mesopores existed in the whole sub-microspheres with superior light scattering ability. The appropriate pore diameter and relatively high specific surface area of the as-obtained sub-microsphere result in a higher dye adsorption. As expected, by using the sub-microspheres as a scattering layer, a higher photovoltaic conversion efficiency of 10.15% is obtained for DSSCs.
SYNTHESIS AND ORGANIZATION OF PLATINUM NANOPARTICLES AND NANOSHELLS ON A NATIVE VIRUS BIOSCAFFOLD
Authors: HOU LI , TONG DANDAN , JIANG YANG , GAO FAMING
Published: March 2014

A wild type virion, bacteriophage T4, was used as an organic template for the controlled synthesis and organization of Pt nanoparticles and nanoshells on its capsid. A long incubation of T4 virions with the metalchloride solution is necessary to the specific binding of the external surface of T4 capsid with PtIVby means of interactions between PtIVand the chemical functionality found inherently on the surface of the proteinaceous viral capsid. After chemical reduction with dimethylaminoborane (DMAB), the highly dispersive Pt nanoparticles with a uniform size of 3–4 nm were synthesized and covered the whole viral capsid. The packing density of Pt nanoparticles was enhanced by increasing the incubation cycles of the virions in metal salt solution. Moreover, Pt @T4 shell/core structures could be achieved by increasing the amount of metal ions around virons. UV/vis spectroscopy was used to follow the course of the reaction, and the formation mechanism was discussed. Both the small Pt nanoparticles and Pt @T4 shell/core structures show high electrocatalytic activity in electrochemical measurement, and therefore are expected to have potential applications in electrocatalysis.
Almost periodic solution of a modified Leslie–Gower predator–prey model with Holling-type II schemes and mutual interference
Authors: Yu Shengbin , Chen Fengde
Published: March 2014

In this paper, we consider a modified Leslie–Gower predator–prey model with Holling-type II schemes and mutual interference. By applying the comparison theorem of the differential equation and constructing a suitable Lyapunov function, sufficient conditions which guarantee the permanence and existence of a unique globally attractive positive almost periodic solution of the system are obtained. Our results not only supplement but also improve some existing ones.
On a reaction–diffusion model for sterile insect release method on a bounded domain
Authors: Jiang Weihua , Li Xin , Zou Xingfu
Published: March 2014

We consider a system of partial differential equations that describes the interaction of the sterile and fertile species undergoing the sterile insect release method (SIRM). Unlike in the previous work [M. A. Lewis and P. van den Driessche, Waves of extinction from sterile insect release, Math. Biosci.5 (1992) 221–247] where the habitat is assumed to be the one-dimensional whole space ℝ, we consider this system in a bounded one-dimensional domain (interval). Our goal is to derive sufficient conditions for success of the SIRM. We show the existence of the fertile-free steady state and prove its stability. Using the releasing rate as the parameter, and by a saddle-node bifurcation analysis, we obtain conditions for existence of two co-persistence steady states, one stable and the other unstable. Biological implications of our mathematical results are that: (i) when the fertile population is at low level, the SIRM, even with small releasing rate, can successfully eradicate the fertile insects; (ii) when the fertile population is at a higher level, the SIRM can succeed as long as the strength of the sterile releasing is large enough, while the method may also fail if the releasing is not sufficient.
N-glycosylation and topology of the human SLC26 family of anion transport membrane proteins
Authors: Li Jing , Xia Fan , Reithmeier Reinhart A. F.
Published: March 2014

The human solute carrier ( SLC26) family of anion transporters consists of 10 members ( SLCA1–11, SLCA10 being a pseudogene) that encode membrane proteins containing ∼12 transmembrane (TM) segments with putative N-glycosylation sites (-NXS/T-) in extracellular loops and a COOH-terminal cytosolic STAS domain. All 10 members of the human SLC26 family, FLAG-tagged at the NH2 terminus, were transiently expressed in HEK-293 cells. While most proteins were observed to contain both high-mannose and complex oligosaccharides, SLC26A2 was mainly in the complex form, SLC26A4 in the high-mannose form, and SLC26A8 was not N-glycosylated. Mutation of the putative N-glycosylation sites showed that most members contain multiple N-glycosylation sites in the second extracytosolic (EC) loop, except SLC26A11, which was N-glycosylated in EC loop 4. Immunofluorescence staining of permeabilized cells localized the proteins to the plasma membrane and the endoplasmic reticulum, with SLC26A2 highly localized to the plasma membrane. N-glycosylation was not a necessary requirement for cell surface expression as the localization of nonglycosylated proteins was similar to their wild-type counterparts, although a lower level of cell-surface biotinylation was observed. No immunostaining of intact cells was observed for any SLC26 members, demonstrating that the NH2-terminal FLAG tag was located in the cytosol. Topological models of the SLC26 proteins that contain an even number of transmembrane segments with both the NH2 and COOH termini located in the cytosol and utilized N-glycosylation sites defining the positions of two EC loops are presented.
Female spontaneously hypertensive rats are more dependent on ANG (1-7) to mediate effects of low-dose AT1 receptor blockade than males
Authors: Zimmerman Margaret A. , Harris Ryan A. , Sullivan Jennifer C.
Published: March 2014

ANG (1-7) contributes to the blood pressure (BP)-lowering effect of angiotensin receptor blockers (ARBs) in male experimental animals. Females have greater ANG (1-7) concentrations than males; however, the contribution of ANG (1-7) to ARB-mediated decreases in BP in females is unknown. The current study tested the hypothesis that female spontaneously hypertensive rats (SHR) have a larger ANG (1-7) contribution to the BP-lowering effects of the ARB candesartan than male SHR. Twelve-week-old male and female SHR were randomized to receive candesartan (0.5 mg·kg−1·day−1; 7 days), candesartan plus ANG II (200 ng·kg−1·min−1; 7 days), the ANG (1-7) antagonist A-779 (48 μg·kg−1·h−1) plus candesartan and ANG II. Candesartan decreased basal BP in males and females (baseline vs. candesartan: 142 ± 2 vs. 122 ± 3 and 129 ± 1 vs. 115 ± 1 mmHg, respectively; P < 0.05); however, the decrease was greater in males. ANG II increased BP in males in the presence of candesartan (149 ± 2 mmHg; P < 0.05); candesartan blocked ANG II-induced increases in BP in females (116 ± 1 mmHg). Pretreatment with A-779 abolished candesartan-mediated decreases in BP in females, but not males. A-779 also exacerbated ANG II-induced proteinuria (26 ± 6 vs. 77 ± 11 μg·kg−1·day−1, respectively; P < 0.05) and nephrinuria (20 ± 5 vs. 202 ± 58 μg·kg−1·day−1, respectively; P < 0.05) in candesartan-treated female SHR, with no effect in males. In conclusion, females are more sensitive to the BP-lowering effect of ARBs during ANG II infusion, whereas males are more sensitive under basal conditions. In addition, ANG (1-7) has a greater contribution to ARB-mediated decreases in BP, protein, and nephrin excretion in females relative to males.
Cells of renin lineage take on a podocyte phenotype in aging nephropathy
Authors: Pippin Jeffrey W. , Glenn Sean T. , Krofft Ronald D. , Rusiniak Michael E. , Alpers Charles E. , Hudkins Kelly , Duffield Jeremy S. , Gross Kenneth W. , Shankland Stuart J.
Published: March 2014

Aging nephropathy is characterized by podocyte depletion accompanied by progressive glomerulosclerosis. Replacement of terminally differentiated podocytes by local stem/progenitor cells is likely a critical mechanism for their regeneration. Recent studies have shown that cells of renin lineage (CoRL), normally restricted to the kidney's extraglomerular compartment, might serve this role after an abrupt depletion in podocyte number. To determine the effects of aging on the CoRL reserve and if CoRL moved from an extra- to the intraglomerular compartment during aging, genetic cell fate mapping was performed in aging Ren1cCre × Rs-ZsGreen reporter mice. Podocyte number decreased and glomerular scarring increased with advanced age. CoRL number decreased in the juxtaglomerular compartment with age. There was a paradoxical increase in CoRL in the intraglomerular compartment at 52 and 64 wk of age, where a subset coexpressed the podocyte proteins nephrin, podocin, and synaptopodin. Transmission electron microscopy studies showed that a subset of labeled CoRL in the glomerulus displayed foot processes, which attached to the glomerular basement membrane. No CoRL in the glomerular compartment stained for renin. These results suggest that, despite a decrease in the reserve, a subpopulation of CoRL moves to the glomerulus after chronic podocyte depletion in aging nephropathy, where they acquire a podocyte-like phenotype. This suggests that they might serve as adult podocyte stem/progenitor cells under these conditions, albeit in insufficient numbers to fully replace podocytes depleted with age.