bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrafast Laser Fabrication of Hybrid Micro‐ and Nano‐Structures in Semiconductor‐doped Borosilicate Glasses
Authors: Mardilovich Pavel , Fletcher Luke B. , Troy Neil W. , Yang Lihmei , Huang Huan , Risbud Subhash H. , Krol Denise M. 
Published: April 2013

Femtosecond (fs)‐laser processing of CdSxSe1‐x‐doped borosilicate glasses was investigated to create hybrid multiscale structures consisting of semiconductor nanocrystals embedded in microscopic domains defined by the laser irradiation. Laser processing was carried out with both low (1 KHz) and high (1 MHz) repetition rate fs‐lasers using pulse fluences between 2 and 2000 J/cm2 and sample scan speeds ranging from 0.05 to 4 mm/s. The samples were subsequently heat‐treated at temperatures between 500 and 600°C and characterized using optical microscopy, electron microscopy, wave dispersive x‐ray spectroscopy (WDS), and confocal fluorescence microscopy. For 1‐KHz laser processing conditions, nanocrystal precipitation showed no significant distinction between the modified and unmodified regions in the sample. Using a 1‐MHz pulse repetition rate laser, however, we introduced chemical inhomogeneity across microscopic modifications, forming three chemically distinct regions: sodium and potassium‐rich, zinc rich, and silicon rich. These regions exhibited different semiconductor precipitation dynamics, with the sodium and potassium‐rich region showing strong preferential precipitation of cadmium sulfo‐selenide nanoparticles, thereby localizing quantum dot precipitation to these chemically defined microcrucibles in the glass.
Identification and biochemical characterization of Laodelphax striatellus neutral ceramidase
Authors: Zhou Y. , Lin X.‐W. , Zhang Y.‐R. , Huang Y.‐J. , Zhang C.‐H. , Yang Q. , Li H.‐Y. , Yuan J.‐Q. , Cheng J.‐A. , Xu R. , Mao C. , Zhu Z.‐R. 
Published: April 2013

AbstractCeramidases are a group of enzymes that catalyse hydrolysis of ceramides to generate fatty acid and sphingosine. In this study, we report the cloning and characterization of the rice small brown planthopper Laodelphax striatellus neutral ceramidase (nCDase), LsnCer. LsnCer was identified by sequencing the transcriptome of L. striatellus and is a protein of 717 amino acids with a predicted molecular weight of 79.3 kDa. Similarly to other known nCDases, the optimum pH for LsnCer is 8.0 and the optimum temperature is 37 °C for its in vitro activity. LsnCer activity is inhibited by Zn2+ significantly and Fe2+ slightly. LsnCer has broad substrate specificity with a preference for ceramides with a medium acyl‐chain or a monounsaturated long acyl‐chain. Infection with rice strip virus (RSV) or treatment with insecticides significantly increased LsnCer mRNA expression and its enzymatic activity in L. striatellus. These results suggest that LsnCer is a bona fide nCDase that may have a role in adaption of L. striatellus to environmental stresses.
Polish Contemporary Migration: From Co‐migrants to Project ME
Authors: Isański Jakub , Mleczko Agata , Eid Renata Seredyńska‐Abou 
Published: April 2013

AbstractInternational migration mirrors contemporary society in all its complexity. What has not changed for centuries is the principal motif: people leave their country of origin hoping for a better life. Poland has a long history of emigration: Poles have been migrating for more than 200 years for political, economic and social reasons. In recent decades, Polish migration patterns have undergone dramatic changes. Using online survey data, this article explores new trends in Polish migration since the country's accession to the European Union in 2004. The survey was focused on Polish migrants who stayed abroad for some time, those who stayed abroad before the accession, those who returned to Poland or those who experienced multiple travels and have an ongoing migration project.We conclude that new trends have emerged among Polish migrants. Contemporary migrants are aware of the benefits related to migration and are capable of implementing their migration project quite skilfully. Their high susceptibility to the economic setting proves their flexibility. Polish migrants highly value their new lifestyle abroad and consider friends their most important source of support.
Image cytometer method for automated assessment of human spermatozoa concentration
Authors: Egeberg D. L. , Kjærulff S. , Hansen C. , Petersen J. H. , Glensbjerg M. , Skakkebæk N. E. , Jørgensen N. , Almstrup K. 
Published: April 2013

SummaryIn the basic clinical work‐up of infertile couples, a semen analysis is mandatory and the sperm concentration is one of the most essential variables to be determined. Sperm concentration is usually assessed by manual counting using a haemocytometer and is hence labour intensive and may be subjected to investigator bias. Here we show that image cytometry can be used to accurately measure the sperm concentration of human semen samples with great ease and reproducibility. The impact of several factors (pipetting, mixing, round cell content, sperm concentration), which can influence the read‐out as well as inter‐operator and ‐cytometer variation on two different image cytometers (NC‐3000 and SP‐100) were evaluated. Furthermore, 725 semen samples were assessed both by manual assessment (WHO recommended method) and by image cytometry and tight correlations between the measured concentrations were shown. Moreover, by evaluation of repeated measurements it appeared that image cytometry produced more consistent and accurate measurements than manual counting of human spermatozoa concentration. In conclusion, image cytometry provides an appealing substitute of manual counting by providing reliable, robust and easy measurement of human sperm concentration.
Retrograde ejaculation and sexual dysfunction in men with diabetes mellitus: a prospective, controlled study
Authors: Fedder J. , Kaspersen M. D. , Brandslund I. , Højgaard A. 
Published: April 2013

SummaryRetrograde ejaculation (RE) and erectile dysfunction may be caused by diabetes mellitus (DM), but the prevalence of RE among DM patients is unknown. A prospective, blinded case–control study comparing men with DM with matched controls according to RE and erectile dysfunction was performed. Twenty‐seven men with DM matched the inclusion criteria and agreed to participate in the study, and of these 26 delivered an ejaculate. We were able to recruit 18 matching controls, and of these 16 delivered an ejaculate.Nine of 26 men with DM who delivered an ejaculate had RE, whereas none of 16 controls had RE (p < 0.01). The mean duration of DM was longer for DM patients with RE (20 years) compared with DM patients in whom RE could not be demonstrated (13 years), but the difference was not statistically significant. RE could not be associated with BMI, waist circumference, blood pressure, Haemoglobin A1c (HgbA1c), high‐density lipoprotein HDL cholesterol, triglycerides, fasting glucose, or s‐testosterone. Diabetics suffering from RE more frequently exhibited erectile dysfunction compared with non‐diabetics and diabetics without RE, and the last‐mentioned group again more frequently than controls. These findings could not be explained by use of antihypertensive drugs.Whereas none of the included control participants showed signs of abnormal ejaculation, every third man with DM exhibited retrograde ejaculation. It is important to be aware of this association, and that post‐ejaculatory urine is routinely analysed from aspermic fertility clinic attendants and diabetics with low ejaculate volumes.
Effects of Mg Substitution on Order/disorder Transition, Microstructure, and Microwave Dielectric Characteristics of Ba((Co0.6Zn0.4)1/3Nb2/3)O3 Complex Perovskite Ceramics
Authors: Ma Pian Pian , Yi Lei , Liu Xiao Qiang , Li Lei , Chen Xiang Ming 
Published: April 2013

Effects of Mg substitution on order/disorder transition, microstructure, and microwave dielectric characteristics of Ba((Co0.6Zn0.4)1/3Nb2/3)O3 complex perovskite ceramics have been investigated. The ordered complex perovskite solid solutions are obtained in Ba((Co0.6−x/2Zn0.4−x/2Mgx)1/3Nb2/3)O3 ceramics (x = 0, 0.1, 0.2, and 0.3), and the ordering degree in the as‐sintered dense ceramics increases with increasing Mg‐substitution amount. The significantly improved Qf value is obtained in the present ceramics with increasing x, whereas the dielectric constant decreases slightly together with some increase of temperature coefficient of resonant frequency. The best combination of microwave dielectric characteristics is obtained in the composition of x = 0.3: εr = 33.7, Qf = 93 800 GHz, and τf = 9.6 ppm/°C. In the Mg‐substituted compositions, clear domain boundaries are obtained and the domain size increases as x increases, the highest Qf value is obtained when the domain size is about 40–60 nm in the ceramics with x = 0.3. The increased ordering degree and the fine ordering domain structure are considered to primarily contribute to the significant increase of Qf value in the Mg‐substituted Ba((Co0.6Zn0.4)1/3Nb2/3)O3 complex perovskite ceramics.
Silicon Carbide Oxidation in High‐Pressure Steam
Authors: Cheng Ting , Tortorelli Peter F. 
Published: April 2013

Silicon carbide is a candidate cladding for fission power reactors that can potentially provide better accident tolerance than zirconium alloys. SiC has also been discussed as a host matrix for nuclear fuel. Chemical vapor–deposited silicon carbide specimens were exposed in 0.34–2.07 MPa steam at low gas velocity (~50 cm/min) and temperatures from 1000°C to 1300°C for 2–48 h. As previously observed at lower steam pressure of 0.15 MPa, a two‐layer SiO2 scale was formed during exposure to these conditions, composed of a porous cristobalite layer above a thin, dense amorphous SiO2 surface layer. Growth of both layers depends on temperature, time, and steam pressure. A quantitative kinetics model is presented to describe the SiO2 scale growth, whereby the amorphous layer is formed through a diffusion process and linearly consumed by an amorphous to crystalline phase transition process. Paralinear kinetics of SiC recession were observed after exposure in 0.34 MPa steam at 1200°C within 48 h. High‐pressure steam environments are seen to form very thick (10–100 μm) cristobalite SiO2 layers on CVD SiC even after relatively short‐term exposures (several hours). The crystalline SiO2 layer and SiC recession rate significantly depend on steam pressure. Another model is presented to describe the SiC recession rate in terms of steam pressure when a linear phase transition kl governing the recession kinetics, whereby the reciprocal of recession rate is found to follow a negative unity steam pressure power law.
Identification of Substitution Mechanism in Group VIII Metal Oxides Doped Pb(Zn1/3Nb2/3)O3–PbZrO3–PbTiO3 Ceramics with High Energy Density and Mechanical Performance
Authors: Zheng Mupeng , Hou Yudong , Wang Sai , Duan Chenghui , Zhu Mankang , Yan Hui 
Published: April 2013

Group VIII metal oxides, that is, Fe2O3, Co2O3, and NiO have been introduced to 0.2Pb(Zn1/3Nb2/3)O3–0.8Pb(Zr0.50Ti0.50)O3 (PZN–PZT) to deterministically identify the substitution mechanism and meantime to tailor mechanical and piezoelectric properties in obtaining energy harvesting materials. On the basis of the X‐ray diffraction and Raman analysis, it is clear that the group VIII metal oxides induce a phase transformation from the morphotropic phase boundary to the tetragonal phase side, and the corresponding grain size increases accordingly. It is reasonable to deduce that two types of substitution behaviors coexist in the group VIII metal oxides added PZN–PZT system. Due to the mixed valence of +2 and +3, the foreign doping ions prefer to enter the B site in the perovskite structure, not only substituting for Ti4+, Zr4+, and Nb5+ ions in the inequivalence replacement but also substituting for Zn2+ ions in the equivalence replacement. The proposed complex substitution mechanisms can give the full explanation about the grain growth phenomena and the variation in mechanical and electric properties in the modified PZN–PZT system. At the same doping level of 0.3 mol%, the maximum transduction coefficient (d33·g33 = 13120 × 10−15 m2/N) and good fracture toughness (KIC = 1.32 MPa m1/2) are obtained in Co2O3 added 0.2PZN–0.8PZT ceramics, which shows great promise as practical materials for energy harvesting device applications.
Pressureless Sintering of Hafnium Carbide–Silicon Carbide Ceramics
Authors: Liu Ji‐Xuan , Huang Xiao , Zhang Guo‐Jun 
Published: April 2013

HfC‐30 vol%SiC ceramics with a relative density of 99.7% was obtained by pressureless sintering at 2300°C for 0.5 h. The resultant ceramics showed fine microstructure with HfC grain size around 1 μm. The hardness (20.5 ± 0.2 GPa), bending strength (396 ± 56 MPa), and fracture toughness (2.81 ± 0.18 MPa·m1/2) of HfC‐30 vol%SiC ceramics were at least 20% higher than those of monolithic HfC ceramics. The influences of SiC particle size, volume fraction, and the oxide impurity on the microstructure evolution of HfC‐based ceramics were examined. The results indicate that SiC addition and the oxygen impurity introduced by ball milling play opposite roles in the HfC grain growth during sintering. The oxide impurity introduced by ball milling caused the HfC grain coarsening, whereas SiC particles inhibited the grain growth of HfC significantly.
Characterization of Elastic Properties in Porous Silicon Carbide Preforms Fabricated Using Polymer Waxes as Pore Formers
Authors: Roy Siddhartha , Schell Karl Günter , Bucharsky Ethel Claudia , Weidenmann Kay André , Wanner Alexander , Hoffmann Michael J. 
Published: April 2013

Thorough elastic analysis of porous silicon carbide preforms fabricated using two different polymer waxes as pore formers is carried out. Both the amount and the mixture ratio of the waxes were varied to fabricate preforms with different pore morphologies and porosities in the range of 27–67 vol%. Results show that both the longitudinal and the shear elastic constants decrease with increasing porosity. The rate of decrease in the elastic constants follows a model based on minimum solid area up to an intermediate porosity level. Uniaxial pressure applied prior to cold isostatic pressing and sintering significantly reduces the stiffness along the press direction. For the same initial powder mixture type, the elastic anisotropy of the preforms increases with an increase in the applied uniaxial pressure. The extent of anisotropy is strongly dependent on both the SiC/wax ratio as well as the mixture ratio between the two wax types. At low pore volume fractions a higher volume content of the smaller diameter wax and at high pore volume fractions a higher volume content of larger diameter wax lead to preforms with lowest anisotropy. A map is finally proposed to describe the dependence of the preform elastic properties on the type of initial powder mixture used.
Fabrication and Characterization of Nanoscale Ferroelectric Honeycombs
Authors: Kim Bongsoo , Hong Seungbum , Choi Hyunwoo , Ryu Won‐Hee , Paik Haemin , Choi Yoon‐Young , Kwon Hyuk‐Sang , No Kwangsoo 
Published: April 2013

Nanoscale ferroelectric honeycombs, comprised of vertically aligned PbTiO3 nanotubes, are fabricated by vapor phase reaction between lead acetate‐infiltrated TiO2 nanotubes and PbO vapor. PbTiO3 nanohoneycombs converted by vapor phase reaction at 550°C showed well‐aligned nanoscale structure with alignment angle less than 1° and well‐defined ferroelectric properties with the effective piezoelectric coefficient of 44 pm/V. This novel nanoscale structure is expected to facilitate high efficiency sensing of electromechanical and electrochemical stimuli.
Effects of Solids Loading on Sintering and Properties of Freeze‐Cast Kaolinite–Silica Porous Composites
Authors: Li Wenle , Lu Kathy , Walz John Y. 
Published: April 2013

Kaolinite–silica nanocomposites with a green porosity ranging from 75% to 87% were prepared using a freeze‐casting technique. The initial solids loading values (kaolinite platelets plus silica nanospheres) greatly influence the sintering behavior as well as the phase and strength of the resulting porous composites. The composites with lower solids loading exhibit faster sintering (e.g., larger shrinkage, more extensive thickening of the pore walls) when sintered at 1250°C, which in turn, results in a rapid increase in flexural strength. All the composites maintain a high porosity (above 50%) after sintering at 1250°C for 72 h, whereas the flexural strength of the composites increases from roughly 0.2 MPa for the green samples to 13.3, 7.5, and 6.5 MPa for 12, 18, and 24 vol% solids samples, respectively, after sintering. It is believed that solids loading affects kaolinite–silica packing during the sol‐to‐gel transition as a minimum amount of silica nanoparticles is required to build the gel network. This particle packing difference influences the amount of kaolinite–silica interfacial contact, which in turn affects the strength. The strength increase through solids loading change is a combined effect of changes in the porous structure during sintering plus the development of a new phase at the silica–kaolinite interface.
Effect of Substrate on Structure and Multiferrocity of (La,Mn) CoSubstituted BiFeO3 Thin Films
Authors: Wang D. Y. , Ding R. , Li S. 
Published: April 2013

In this article, we report the substrate effect on ferroelectric and magnetic properties of epitaxial BiFeO3‐based thin films at room temperature. (La, Mn) cosubstituted BiFeO3 (BFOLM) thin films were deposited on differently lattice mismatched single‐crystal substrates to manipulate the strain states in the as‐deposited films. All the films with 30‐nm thick CaRuO3 bottom electrodes exhibited highly epitaxial growth behavior with a slightly monoclinic distorted lattice structure while their strain states are drastically different as confirmed by X‐ray reciprocal space mapping. These films possessed significantly different macroscopic ferroelectric properties with giant remanent polarization of 101 ± 2, 65 ± 2, and 48 ± 2 μC/cm2 for the films grown on SrTiO3, (La, Sr)(Al, Ta)O3, and LaAlO3, respectively. It is found that the room‐temperature magnetic properties are also in accordance with their strain state, having a reciprocal relationship with polarization. For example, the enhanced magnetization is associated with the suppressed polarization and vice versa. The stain tunability of multiferroic properties in BFOLM thin films are presumably ascribed to the polarization rotation and oxygen octahedral tilts.
Ethical sensitivity in practice: finding tacit moral knowing
Authors: Van Der Zande Marlies , Baart Andries , Vosman Frans 
Published: April 2013

AbstractAimThis article presents a discussion of the conceptual model of ethical sensitivity.BackgroundRecent research pays little attention to the tacit dimension of ethical knowledge. We focus on care practices, drawing a distinction between explicit moral knowledge and tacit moral knowing. This focus has far‐reaching methodological consequences, influences the research design of empirical research and enables healthcare workers to discern both explicit and tacit knowing.Data sourcesThis article draws on literature about tacit knowledge, practices and ethical sensitivity, covering publications from 1958–2011. Data used in the illustrative cases were gathered in 2009 during the phenomenological phase of a multiple‐case study.DiscussionTaking practices as the point of entry for exploring ethical sensitivity makes it possible to study empirically both explicit moral knowledge and tacit moral knowing. Given how relevant practical knowledge is, we aim to put forward a theoretical framework that leaves room for the discernment of this tacit moral knowing.Implications for nursingCreating opportunities to reflect on daily ethical concerns in an inter‐professional team can contribute to improvement on quality of care.ConclusionThe broadened perspective on ethical sensitivity can be used as a heuristic device to discern what both explicit and implicit moral knowledge in care are about. This empirical way of looking at care practices can enhance the awareness of the moral knowing of the professional caregiver.
Family caregiver strategies to encourage older relatives with dementia to use social services
Authors: Takai Yukari , Yamamoto‐Mitani Noriko , Okamoto Yuko , Fukahori Hiroki , Ko Ayako , Tanaka Makoto 
Published: April 2013

AbstractAimTo elicit the strategies used by Japanese family caregivers in the community to encourage older relatives with dementia to use adult daycare and respite stays.BackgroundOlder adults with dementia often require adult daycare and respite stays for their family caregivers to gain respite from care‐giving. However, persons with dementia often face difficulty in new environments and timely access to sufficient services may be difficult to achieve. Few studies have examined how family caregivers encourage their service use.DesignA qualitative method.MethodsSemi‐structured interviews were conducted with 16 family caregivers who were caring for relatives with dementia at home between 2005–2007. Data were analysed qualitatively.ResultsFamily caregivers used various strategies to encourage older relatives to use services, allowing the older adult to decide whether to use the service, yearning and searching for the least harmful service, tailoring the service to the older adult, persuading the older adult to use the service, conforming the older adult to the service and coercing the older adult to use the service. Different strategies were used depending on factors such as desperation in needing respite, willingness to do what is best for the older adult, confidence in taking care of the older adult and the anticipated response of the older adult to services.ConclusionNurses should carefully assess caregivers' strategies in their attempts to encourage service use and should provide adequate assistance in accordance with those strategies.
Modelling landscape dynamics in a glacial refugium – or the spatial and temporal fluctuations of tree line altitudes
Authors: Marta Silvio , Mattoccia Marco , Sbordoni Valerio 
Published: April 2013

AbstractAimTo produce a dynamic model of tree line position and habitat suitability for temperate and warm temperate forests, with high spatial and temporal resolution from the Last Glacial Maximum to the present, using an approach based on the quasi‐constant altitudinal difference between the tree line altitude (TLA) and the equilibrium line altitude (ELA) of glaciers.LocationCentral Mediterranean.MethodsData sets of current tree line position and ELA were integrated and five different scenarios of tree line shifts were simulated at a millennial scale. The model was parameterized using a dense palynological data set (964 time points, representing 121 pollen sampling sites). The simulated tree line fluctuations were compared with those of the boreal forest reconstructed using field data from the southern Alps.ResultsThe reconstructed evolution of TLA yielded good results for the interval of tree line formation (correct assignment rate: lower limit = 98.29%; upper limit = 94.29%) and the best‐fitting scenario within each millennium tree line (combined scenarios: AUC ± 2 SD = 0.877 ± 0.047; Kappa ± 2 SD = 0.651 ± 0.100). There was also strong agreement between the simulated and the reconstructed tree line fluctuations for both the timing and magnitude of tree line shift.Main conclusionsAlthough all the analyses support the hypothesis of a quasi‐constant difference between TLA and ELA, we found a major relative upward shift of the tree line position within the interval of tree line formation, probably due to the increase in both precipitation and atmospheric CO2 concentration since the onset of the Bølling–Allerød Interstadial. Palaeodistribution maps may be useful for drawing inferences about the biogeography of single temperate and warm temperate species or for recolonization simulations; however, model‐based inferences will need to account for several variables, including local climate variability, fire and herbivore disturbance, and lack of complete spatial association between modelled forests and species of interest.