bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Seed Addition on SnO2‐Based Varistors for Low Voltage Application
Authors: Cilense Mario , Ramirez Miguel Angel , Foschini Cesar Renato , Leite Daniela Russo , Simões Alexandre Zirpoli , Bassi Welson , Longo Elson , Varela José Arana 
Published: November 2012

The effect of seed addition on the microstructure and non‐ohmic properties of the SnO2 + 1%CoO + 0.05%Nb2O5 ceramic‐based system was analyzed. Two classes of seeds were prepared: 99% SnO2 + 1%CuO and 99% SnO2 + 1%CoO (mol%); both classes were added to the ceramic‐based system in the amount of 1%, 5%, and 10%. The two systems containing 1% of seeds resulted in a larger grain size and a lower breakdown voltage. The addition of 1% copper seeds produces a breakdown voltage (Vb) of ~ 37 V and a leakage current (fic) of 29 μA. On the other hand, the addition of 1% cobalt seeds produced a breakdown voltage of 57 V and a leakage current of 70 μA. Both systems are of great technological interest for low voltage varistor applications, by means of appropriate strategies to reduce the leakage current. Using larger amounts of seeds was not effective since the values of breakdown voltage in both cases are close to a system without seeds. To our knowledge, there are no reports in the literature regarding the use of seeds in the SnO2 system for low voltage applications. A potential barrier model which illustrates the formation of oxygen species (O′2(ads), O′ads, and O″ads) at the expense of clusters near the interface between grains is proposed.
Preparation of NaA Zeolite Membranes Using Poly(Ethyleneimine) as Buffer Layer, and Study of Their Permeation Behavior
Authors: Dey Kartick P. , Kundu Debtosh , Chatterjee Minati , Naskar Milan K. 
Published: November 2012

Zeolite NaA membranes were prepared hydrothermally by secondary crystallization process at different temperatures (55°C–75°C) on porous α‐alumina‐based support tubes (inner side) precoated with poly(ethyleneimine) (PEI) buffer layer and NaA seed particles. The NaA seed crystals synthesized at 65°C/2 h in the size range 100–200 nm having BET surface area of 71.57 m2g−1 were used for secondary crystallization of the membranes. The secondary crystallization at 65°C for (4 + 4) h (double‐stage) showed highly dense NaA grains in the microstructure of the membrane with a thickness of 5 μm. It rendered the permeance values of 50.6 × 10−8, 2.47 × 10−8, and 0.55 × 10−8 molm−2s−1Pa−1 for H2, N2, and CO2, respectively, with their permselectivity of 20.48 (H2/N2), 92 (H2/CO2), and 4.49 (N2/CO2). A tentative mechanism was illustrated for the interaction of PEI with the support substrate and NaA seed crystals.
Structural Evolving Sequence and Porous Ba6Zr2Nb8O30 Ferroelectric Ceramics with Ultrahigh Breakdown Field and Zero Strain
Authors: Zhang Shan‐Tao , Yuan Guoliang , Chen Jun , Gu Zheng‐Bin , Yang Bin , Yin Jiang , Cao Wenwu 
Published: November 2012

Microstructural evolving sequence of relaxor ferroelectric Ba6Zr2Nb8O30 (BZN) ceramics has been investigated and discussed. Porous BZN, which has an irregular grain network with pores, can be obtained within a narrow sintering window (sintering temperature of ~1250°C and dwelling time of ~5 h in our experiments). X‐ray diffraction‐based structure refinements determine the atomic positions and confirm that the porous ceramics has tetragonal tungsten bronze structure with P4bm space group symmetry. It is found that the most porous ceramic has the lowest dielectric constant, highest electric field breakdown strength, and nearly zero macroscopic electric field‐induced strain. These features can be related to the porous microstructures by comparing with the denser counterparts and can be well understood by using brick‐wall model. Our results may provide useful information for the understanding of microstructure evolving sequence of BZN during sintering and the structural effects on electric properties of ceramics. Our work may also provide a reliable way for developing porous ferroelectric ceramics with special properties.
Synthesis of Nanofiber‐like Mesoporous γ‐Al2O3 toward Its Adsorption Efficiency for Congo Red
Authors: Ghosh Sourav , Dey Kartick P. , Naskar Milan K. 
Published: November 2012

Nanofiber‐like mesoporous γ‐Al2O3 was synthesized using freshly prepared boehmite sol in the presence of triblock copolymer, P123 following evaporation‐induced self‐assembly (EISA) process followed by calcinations at 400°C–1000°C. The samples were characterized by thermogravimetry (TG), differential thermal analysis (DTA), X‐ray diffraction (XRD), N2 adsorption–desorption, and transmission electron microscopy (TEM). The adsorption efficiency of the samples with Congo red (CR) was studied by UV–vis spectroscopy. XRD results showed boehmite phase in the as‐prepared sample while γ‐Al2O3 phase obtained at 400°C was stable up to 900°C, a little transformation of θ‐Al2O3 resulted at 1000°C. The Brunauer‐Emmett‐Teller surface area of the 400°C‐treated sample was found to be 175.5 m2g−1. The TEM micrograph showed nanofiber‐like morphology of γ‐Al2O3. The 400°C‐treated sample showed about 100% CR adsorption within 60 min.
Electrical Conduction and Dielectric Properties of the Rb‐doped CaCu3Ti4O12
Authors: Yang Zhi , Zhang Yue , Lu Zhihong , Zhang Kun , Xiong Rui , Shi Jing 
Published: November 2012

Ca1−xRbxCu3Ti4O12 (x = 0, 0.03, and 0.05) ceramics were synthesized by the sol‐gel method. Their microstructure and electrical properties were investigated. In the Rb‐doped samples, the Cu‐rich and Ti‐poor grain‐boundary layers are formed, and electrical properties are also changed by doping: With the increase in doping concentration, the grain resistivity and the grain‐boundary Schottky potential barrier are changed, the grain‐boundary resistivity is enhanced, and the low‐frequency dielectric constants and loss are reduced. These results were discussed in terms of the internal barrier layer capacitor (IBLC) mechanism, particularly focusing on the electrical properties in grains and the cationic nonstoichiometry at grain boundaries.
Effects of Pueraria mirifica and miroestrol on the antioxidation-related enzymes in ovariectomized mice
Authors: Chatuphonprasert Waranya , Udomsuk Latiporn , Monthakantirat Orawan , Churikhit Yaowared , Putalun Waraporn , Jarukamjorn Kanokwan 
Published: November 2012

Abstract

Objectives
The influences of Pueraria candollei var. mirifica (PM), a Thai medicinal plant with long tradition of medicinal consumption among menopausal women for rejuvenation and estrogen hormone replacement, on oxidative status in ovariectomized (OVX) mice were determined.

Methods
The crude extract of PM and its active phytoestrogen, miroestrol (MR), were given to OVX mice. The effect of them on antioxidation enzymes and glutathione (GSH) levels in livers and uteri were examined in OVX mice and compared with the synthetic estradiol hormone.

Key findings
Ovariectomy significantly decreased total GSH content, reduced GSH content, and the ratio of GSH to oxidized glutathione (GSSG) in both the livers and the uteri of mice. Moreover, an ovariectomy reduced the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). The crude extract of PM as well as MR significantly increased levels of GSH, levels of reduced GSH, and the ratio of GSH/GSSG in both the livers and the uteri, while estradiol did not. In addition, the potential of PM and MR to return the activities of GPx, SOD, and CAT to normal levels was noted.

Conclusions
These observations support using PM and MR as promising alternative medicine candidates for hormone replacement therapy of estradiol because of their ability to improve GSH levels and the activities of antioxidative enzymes, especially in OVX mice.
Increasing sleep duration to lower beat‐to‐beat blood pressure: a pilot study
Authors: Haack Monika , Serrador Jorge , Cohen Daniel , Simpson Norah , Meier‐Ewert Hans , Mullington Janet M. 
Published: November 2012

SummaryStrong evidence has accumulated over the last several years, showing that low sleep quantity and/or quality plays an important role in the elevation of blood pressure. We hypothesized that increasing sleep duration serves as an effective behavioral strategy to reduce blood pressure in prehypertension or type 1 hypertension. Twenty‐two participants with prehypertension or stage 1 hypertension, and habitual sleep durations of 7 h or less, participated in a 6‐week intervention study. Subjects were randomized to a sleep extension group (48 ± 12 years, N = 13) aiming to increase bedtime by 1 h daily over a 6‐week intervention period, or to a sleep maintenance group (47 ± 12 years, N = 9) aiming to maintain habitual bedtimes. Both groups received sleep hygiene instructions. Beat‐to‐beat blood pressure was monitored over 24 h, and 24‐h urine and a fasting blood sample were collected pre‐ and post‐intervention. Subjects in the sleep extension group increased their actigraphy‐assessed daily sleep duration by 35 ± 9 min, while subjects in the sleep maintenance condition increased slightly by 4 ± 9 min (P = 0.03 for group effect). Systolic and diastolic beat‐to‐beat blood pressure averaged across the 24‐h recording period significantly decreased from pre‐ to post‐intervention visit in the sleep extension group by 14 ± 3 and 8 ± 3 mmHg, respectively (P < 0.05). Though the reduction of 7 ± 5 and 3 ± 4 mmHg in the sleep maintenance group was not significant, it did not differ from the blood pressure reduction in the sleep extension group (P = 0.15 for interaction effect). These changes were not paralleled by pre‐ to post‐intervention changes in inflammatory or sympatho‐adrenal markers, nor by changes in caloric intake. While these preliminary findings have to be interpreted with caution due to the small sample size, they encourage future investigations to test whether behavioral interventions designed to increase sleep duration serve as an effective strategy in the treatment of hypertension.
New Evidence on the Impact of Legal Status on Immigrant Labor Market Performance: The Spanish Case
Authors: Amuedo‐Dorantes Catalina , Malo Miguel A. , Muñoz‐Bullón Fernando 
Published: November 2012

AbstractUsing a recent and rich Spanish data set on immigrants, we examine the impact of legal status on two measures of labor market performance: the likelihood of being employed and earnings. The Spanish case is of special interest given the rapid increase in immigration over the past 15 years and the large number of amnesties granted during the 1990s and 2000s. We find that a 10 per cent increase in the share of legal immigrants would raise the overall employment likelihood of immigrants by 4 percentage points and their earnings by 3.3 per cent. The results, which prove robust to alternative sample specifications, confirm the well‐known importance of being legal for the economic assimilation of immigrants.
Candiduria in haematologic malignancy patients without a urinary catheter: nothing more than a frailty marker?
Authors: Georgiadou Sarah P. , Tarrand Jeffrey , Sipsas Nikolaos V. , Kontoyiannis Dimitrios P. 
Published: November 2012

SummaryThere is scarcity of data regarding significance of candiduria in patients with haematologic malignancies and its association with invasive candidiasis. To that end, we retrospectively evaluated all hospitalised, non‐intensive care unit patients with haematologic malignancies and candiduria during a 10‐year period (2001–2011). To decrease the possibility of bladder colonisation and sample contamination, we excluded all patients with candiduria who had urinary catheters and those with concomitant bacteriuria. Twenty‐four such patients (21 females) were identified, with median age at diagnosis 62 years (range, 20–82 years). Acute leukaemia was the most common underlying disease (54%); 62% of these cases were not in remission. Twenty‐nine percent of the patients had diabetes mellitus and 25% were neutropenic. The most common isolated Candida species was Candida glabrata (37%), followed by C. albicans (29%). Only 8% of them had urinary tract infection symptoms. However, 88% received systemic antifungals. Candidemia and crude mortality rates at 4 weeks were low (4% and 12% respectively). Isolated candiduria in patients with haematologic malignancies has risk factors similar to those in other hospitalised patients, and it does not seem to be a strong predictor of subsequent invasive candidiasis.
Association genetics of chemical wood properties in black poplar (Populus nigra)
Authors: Guerra Fernando P. , Wegrzyn Jill L. , Sykes Robert , Davis Mark F. , Stanton Brian J. , Neale David B. 
Published: November 2012

Summary

Black poplar (Populus nigra) is a potential feedstock for cellulosic ethanol production, although breeding for this specific end use is required. Our goal was to identify associations between single nucleotide polymorphism (SNP) markers within candidate genes encoding cellulose and lignin biosynthetic enzymes, with chemical wood property phenotypic traits, toward the aim of developing genomics‐based breeding technologies for bioethanol production.

Pyrolysis molecular beam mass spectrometry was used to determine contents of five‐ and six‐carbon sugars, lignin, and syringyl : guaiacyl ratio. The association population included 599 clones from 17 half‐sib families, which were successfully genotyped using 433 SNPs from 39 candidate genes. Statistical analyses were performed to estimate genetic parameters, linkage disequilibrium (LD), and single marker and haplotype‐based associations.

A moderate to high heritability was observed for all traits. The LD, across all candidate genes, showed a rapid decay with physical distance. Analysis of single marker–phenotype associations identified six significant marker–trait pairs, whereas nearly 280 haplotypes were associated with phenotypic traits, in both an individual and multiple trait‐specific manner.

The rapid decay of LD within candidate genes in this population and the genetic associations identified suggest a close relationship between the associated SNPs and the causative polymorphisms underlying the genetic variation of lignocellulosic traits in black poplar.
An Arabidopsis reticulon and the atlastin homologue RHD3‐like2 act together in shaping the tubular endoplasmic reticulum
Authors: Lee Hannah , Sparkes Imogen , Gattolin Stefano , Dzimitrowicz Natasha , Roberts Lynne M. , Hawes Chris , Frigerio Lorenzo 
Published: November 2012

Summary

The endoplasmic reticulum (ER) is a network of membrane sheets and tubules connected via three‐way junctions. A family of proteins, the reticulons, are responsible for shaping the tubular ER. Reticulons interact with other tubule‐forming proteins (Dp1 and Yop1p) and the GTPase atlastin. The Arabidopsis homologue of Dp1/Yop1p is HVA22.

We show here that a seed‐specific isoform of HVA22 labels the ER in tobacco (Nicotiana tabacum) cells but its overexpression does not alter ER morphology. The closest plant homologue of atlastin is RHD3. We show that RHD3‐like 2 (RL2), the seed‐specific isoform of RHD3, locates to the ER without affecting its shape or Golgi mobility. Expression of RL2‐bearing mutations within its GTPase domain induces the formation of large ER strands, suggesting that a functional GTPase domain is important for the formation of three‐way junctions.

Coexpression of the reticulon RTNLB13 with RL2 resulted in a dramatic alteration of the ER network. This alteration did not depend on an active GTPase domain but required a functional reticulon, as no effect on ER morphology was seen when RL2 was coexpressed with a nonfunctional RTNLB13. RL2 and its GTPase mutants coimmunoprecipitate with RTNLB13.

These results indicate that RL2 and RTNLB13 act together in modulating ER morphology.
Integrative taxonomy and conservation of cryptic beetles in the Mediterranean region (Hydrophilidae)
Authors: Arribas Paula , Andújar Carmelo , Sánchez‐Fernández David , Abellán Pedro , Millán Andrés 
Published: November 2012

Arribas, P., Andújar, C., Sánchez‐Fernández, D., Abellán, P. & Millán, A. (2012). Integrative taxonomy and conservation of cryptic beetles in the Mediterranean region (Hydrophilidae). —Zoologica Scripta, 00, 000–000.Because biodiversity inventory forms the basis for the effective conservation of species and habitats, there is an imperative need to discover and describe new species. A significant part of presently unknown biodiversity is constituted by cryptic species complexes, where traditional taxonomy usually fails due to a lack of clear taxonomic characters in the external structures of specimens. Integrative taxonomy offers a powerful tool to shed light on this part of encrypted biodiversity, combining multiple operational criteria in an evolutionary context in order to delineate species boundaries. The present study used an integrative approach to explore the species boundaries in a water beetle complex (Enochrus falcarius species complex) inhabiting saline streams, a rare and threatened habitat across the Mediterranean region. First, hypotheses about the candidate species on the basis of phylogenetic analyses and biogeographical information were proposed. Second, lineage divergence was evaluated between candidate species using (i) molecular cluster delimitation, (ii) morphometry (both linear body morphometrics and pronotum outlines) and (iii) ecological niche similarity estimates. We found divergence between candidate species on the basis of molecular, biogeographical and niche information, and consequently, four species were delimited within the E. falcarius complex (i.e. Enochrus jesusarribasi sp. n., Enochrus blazquezae sp. n., Enochrus risii sp. n. and Enochrus falcarius), despite the fact that they showed high morphological similarity. Enochrus falcarius, as previously considered, had not been proposed to be of conservational concern, because until now, it had been regarded as a single broadly distributed species in the Mediterranean region. However, the four entities here delimited within this species complex displayed characteristics that categorised them as vulnerable taxa. Hence, these results show how applying integrative taxonomy approaches and rapid vulnerability assessments to lineages from threatened habitats with the potential to comprise cryptic diversity could become a fundamental tool for biodiversity conservation, driving the discovery of cryptic species and consequently the modification of previous, inadequately evaluated vulnerability categorisations.
Mycobacteriophage Ms6 LysA: a Peptidoglycan Amidase and a Useful Analytical Tool
Authors: Mahapatra Sebabrata , Piechota Charles , Gil Filipa , Ma Yufang , Huang Hairong , Scherman Michael S. , Jones Victoria , Pavelka Martin S. , Moniz-Pereira Jose , Pimentel Madalena , McNeil Michael R. , Crick Dean C. 
Published: November 2012

ABSTRACT

Since the peptidoglycan isolated from
Mycobacterium
spp. is refractory to commercially available murolytic enzymes, possibly due to the presence of various modifications found on this peptidoglycan, the utility of a mycobacteriophage-derived murolytic enzyme was assessed for an analysis of peptidoglycan from mycobacteria. We cloned, expressed, and purified the
lysA
gene product, a protein with homology to known peptidoglycan-degrading amidases, from bacteriophage Ms6. The recombinant protein was shown to cleave the bond between
l
-Ala and
d
-muramic acid of muramyl pentapeptide and to release up to 70% of the diaminopimelic acid present in the isolated mycobacterial cell wall. In contrast to lysozyme, which, in culture, inhibits the growth of both
Mycobacterium smegmatis
and
Mycobacterium tuberculosis
, LysA had no effect on the growth of either species. However, the enzyme is useful for solubilizing the peptide chains of isolated mycobacterial peptidoglycan for analysis. The data indicate that the stem peptides from
M. smegmatis
are heavily amidated, containing few free carboxylic acids, regardless of the cross-linking status.
Use of Flow Cytometry for Rapid, Quantitative Detection of Poliovirus-Infected Cells via TAT Peptide-Delivered Molecular Beacons
Authors: Sivaraman Divya , Yeh Hsiao-Yun , Mulchandani Ashok , Yates Marylynn V. , Chen Wilfred 
Published: November 2012

ABSTRACT
Rapid and efficient detection of viral infection is crucial for the prevention of disease spread during an outbreak and for timely clinical management. In this paper, the utility of Tat peptide-modified molecular beacons (MBs) as a rapid diagnostic tool for the detection of virus-infected cells was demonstrated. The rapid intracellular delivery mediated by the Tat peptide enabled the detection of infected cells within 30 s, reaching saturation in signal in 30 min. This rapid detection scheme was coupled with flow cytometry (FC), resulting in an automated, high-throughput method for the identification of virus-infected cells. Because of the 2-order-of-magnitude difference in fluorescence intensity between infected and uninfected cells, as few as 1% infected cells could be detected. Because of its speed and sensitivity, this approach may be adapted for the practical diagnosis of multiple viral infections.
Contribution of Nitrate Assimilation to the Fitness of Pseudomonas syringae pv. syringae B728a on Plants
Authors: Parangan-Smith Audrey , Lindow Steven 
Published: November 2012

ABSTRACT

The ability of
Pseudomonas syringae
pv. syringae to use nitrate as a nitrogen source in culture and on leaves was assessed. Substantial amounts of leaf surface nitrate were detected directly and by use of a bioreporter of nitrate on bean plants grown with a variety of nitrogen sources. While a nitrate reductase mutant,
P. syringae
Δ
nasB
, exhibited greatly reduced growth in culture with nitrate as the sole nitrogen source, it exhibited population sizes similar to those of the wild-type strain on leaves. However, the growth of the Δ
nasB
mutant was much less than that of the wild-type strain when cultured in bean leaf washings supplemented with glucose, suggesting that
P. syringae
experiences primarily carbon-limited and only secondarily nitrogen-limited growth on bean leaves. Only a small proportion of the cells of a green fluorescent protein (GFP)-based
P. syringae
nitrate reductase bioreporter, LK2(pOTNas4), exhibited fluorescence on leaves. This suggests that only a subset of cells experience high nitrate levels or that nitrate assimilation is repressed by the presence of ammonium or other nitrogenous compounds in many leaf locations. While only a subpopulation of
P. syringae
consumes nitrate at a given time on the leaves, the ability of those cells to consume this resource would be strongly beneficial to those cells, especially in environments in which nitrate is the most abundant form of nitrogen.