bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal Invasive Pneumococcal Disease in Children: Role of Preceding Respiratory Viral Infection
Authors: Ampofo Krow , Bender Jeffrey , Sheng Xiaoming , Korgenski Kent , Daly Judy , Pavia Andrew T. , Byington Carrie L.
Published: August 2008

OBJECTIVE. Our objective was to demonstrate correlations between invasive pneumococcal disease in children and circulating respiratory viruses.

METHODS. This retrospective study included 6 winter respiratory viral seasons (2001–2007) in Intermountain Healthcare, an integrated health system in the Intermountain West, including Primary Children's Medical Center in Salt Lake City, Utah. Children <18 years of age who were hospitalized with either invasive pneumococcal disease in any Intermountain Healthcare facility or culture-confirmed invasive pneumococcal disease at Primary Children's Medical Center were included. We analyzed the correlation between invasive pneumococcal disease and circulating respiratory viruses.

RESULTS. A total of 435 children with invasive pneumococcal disease and 203 with culture-confirmed invasive pneumococcal disease were hospitalized in an Intermountain Healthcare facility or Primary Children's Medical Center during the study period. During the same period, 6963 children with respiratory syncytial virus, 1860 with influenza virus, 1459 with parainfluenza virus, and 818 with adenoviruses were evaluated at Primary Children's Medical Center. A total of 253 children with human metapneumovirus were identified during the last 5 months of the study. There were correlations between invasive pneumococcal disease and seasonal respiratory syncytial virus, influenza virus, and human metapneumovirus activity. The correlation with invasive pneumococcal disease was strong up to 4 weeks after respiratory syncytial virus activity. For influenza virus and human metapneumovirus, the correlations were strong at 2 weeks after activity of these viruses. Pneumonia was the most common clinical disease associated with culture-confirmed invasive pneumococcal disease, mostly attributable to serotypes 1, 19A, 3, and 7F.

CONCLUSIONS. In the post–pneumococcal conjugate vaccine era, seasonal increases in respiratory syncytial virus, influenza virus, and human metapneumovirus infections in children were associated with increased pediatric admissions with invasive pneumococcal disease, especially pneumonia caused by nonvaccine serotypes.
Accidental and Nonaccidental Poisonings as a Cause of Apparent Life-Threatening Events in Infants
Authors: Pitetti Raymond D. , Whitman Emily , Zaylor Abigail
Published: August 2008

BACKGROUND. Apparent life-threatening events are a relatively common event in children for which there may be a number of causes. Previous reports have suggested that poisonings, either accidental or intentional, may be causes of some events. However, this theory has not been systematically studied.

METHODS. We conducted a prospective, descriptive study of infants aged <2 years presenting to a pediatric emergency department of a large, urban tertiary care children's hospital with signs and symptoms of an apparent life-threatening event. All of the children presenting with an apparent life-threatening event were to undergo a standardized evaluation, which included obtaining a comprehensive urine toxicology screen. A positive toxicology screen result was defined as follows: a clinically insignificant screen result (identification of a medication that would not cause an apparent life-threatening event) or a clinically significant screen result (identification of a medication that could cause apnea or other event consistent with an apparent life-threatening event, even if it was a medication that the child was known to be taking).

RESULTS. During the study period, 596 children presented to the emergency department with an apparent life-threatening event, and 274 (46.0%) had a toxicology screen performed. Of 274 toxicology screen results, 50 were considered truly positive (18.2%), and 23 positive screen results were considered clinically significant (23 of 274 [8.4%]). Thirteen toxicology screen results were positive for an over-the-counter cold preparation (13 of 274 [4.7%]). No parent admitted to having given his or her child an over-the-counter cold preparation.

CONCLUSIONS. A substantial number of children presenting to the emergency department with an apparent life-threatening event had a positive toxicology screen result. In particular, a number of children were found to have been given an over-the-counter cold preparation. We would recommend that toxicology screens be included as part of the routine evaluation of children who present with an apparent life-threatening event.
Birth Weight and Cognitive Ability in Childhood Among Siblings and Nonsiblings
Authors: Yang Seungmi , Lynch John , Susser Ezra S. , Lawlor Debbie A.
Published: August 2008

OBJECTIVES. The purpose of this work was to examine whether the positive association between birth weight and childhood cognitive ability is seen within siblings from the same family, as well as between nonsiblings, and to determine whether these associations vary with age.

METHODS. We compared the association of birth weight with cognitive ability measured at ages 5 to 6, 7 to 9, and 11 to 12 years among a total of 5402 children from different families with that among 2236 to 3083 sibships from the National Longitudinal Study of Youth 1979-Children.

RESULTS. In the whole cohort, there were positive associations between birth weight and cognitive ability at all ages, with the association increasing with age from a 0.81-point increase at ages 5 to 6 years to 1.30 and 1.44 points at ages 7 to 9 and 11 to 12 years, respectively, per 1 SD of gestational age- and gender-adjusted birth weight z score. With adjustment for covariates, there was marked attenuation of these associations. Mean differences were 0.28 points in children aged 5 to 6 years, 0.67 points in those aged 7 to 9 years, and 0.52 points in those aged 11 to 12 years after adjusting for child's gender, race or ethnicity, year of birth, and age at test; maternal age, height, parity, education, smoking during pregnancy, and cognitive ability; and household income. Our family-based analyses that separated within- and between-family effects found that the between-family associations were much stronger than the within-family associations. However, adjustment for potential confounders attenuated the between-family associations, and there was no evidence for a difference in association comparing the between- and within-family associations.

CONCLUSIONS. In these data, the positive association between birth weight and childhood cognitive ability at ages 5 to 12 years is explained largely by family characteristics rather than a specific intrauterine effect.
Long-Term Outcome of the Ketogenic Diet for Intractable Childhood Epilepsy With Focal Malformation of Cortical Development
Authors: Jung Da Eun , Kang Hoon Chul , Kim Heung Dong
Published: August 2008

OBJECTIVE. We evaluated the efficacy and long-term outcome of the ketogenic diet in patients with intractable childhood epilepsy as a result of focal malformation of cortical development.

METHODS. A retrospective analysis evaluated seizure outcomes of 47 patients who had intractable epilepsy from (and) surgically remediable focal malformation of cortical development and were first treated with the classic ketogenic diet, involving the 4:1 lipid/nonlipid ratio. The long-term prognosis of 21 patients, who became seizure-free 3 months after the ketogenic diet, was followed up with that of 22 patients who eventually underwent epilepsy surgery.

RESULTS. Three months after diet initiation, 29 (61.7%) patients showed a reduction in seizure frequency of >50%, including 21 (44.7%) who became seizure-free. Of the 21 patients with complete seizure control at 3 months, 16 (76.2%) successfully completed the diet for 2 years without relapse, and 10 (47.6%) have remained seizure-free after cessation of the diet (mean follow-up for 3 years and 10 months), including 1 patient who remained seizure-free with additional medication after a relapse. Of the 22 patients who underwent epilepsy surgery, a seizure-free outcome was obtained for 13 (59.1%).

CONCLUSIONS. The ketogenic diet should be considered to be an additional option even in patients with focal malformation of cortical development, and long-term seizure-free outcome can be expected for patients who become seizure-free 3 months after the diet.
Cognitive Function and Brain Structure in Females With a History of Adolescent-Onset Anorexia Nervosa
Authors: Chui Harold T. , Christensen Bruce K. , Zipursky Robert B. , Richards Blake A. , Hanratty M. Katherine , Kabani Noor J. , Mikulis David J. , Katzman Debra K.
Published: August 2008

OBJECTIVE. Abnormalities in cognitive function and brain structure have been reported in acutely ill adolescents with anorexia nervosa, but whether these abnormalities persist or are reversible in the context of weight restoration remains unclear. Brain structure and cognitive function in female subjects with adolescent-onset anorexia nervosa assessed at long-term follow-up were studied in comparison with healthy female subjects, and associations with clinical outcome were investigated.

PATIENTS AND METHODS. Sixty-six female subjects (aged 21.3 ± 2.3 years) who had a diagnosis of adolescent-onset anorexia nervosa and treated 6.5 ± 1.7 years earlier in a tertiary care hospital and 42 healthy female control subjects (aged 20.7 ± 2.5 years) were assessed. All participants underwent a clinical examination, magnetic resonance brain scan, and cognitive evaluation. Clinical data were analyzed first as a function of weight recovery (n = 14, <85% ideal body weight; n = 52, ≥85% ideal body weight) and as a function of menstrual status (n = 18, absent/irregular menses; n = 29, oral contraceptive pill; n = 19, regular menses). Group comparisons were made across structural brain volumes and cognitive scores.

RESULTS. Compared with control subjects, participants with anorexia nervosa who remained at low weight had larger lateral ventricles. Twenty-four–hour urinary free-cortisol levels were positively correlated with volumes of the temporal horns of the lateral ventricles and negatively correlated with volumes of the hippocampi in clinical participants. Participants who were amenorrheic or had irregular menses showed significant cognitive deficits across a broad range of many domains.

CONCLUSIONS. Female subjects with adolescent-onset anorexia nervosa showed abnormal cognitive function and brain structure compared with healthy individuals despite an extended period since diagnosis. To our knowledge, this is the first study to report a specific relationship between menstrual function and cognitive function in this patient population. Possible mechanisms underlying neural and cognitive deficits with anorexia nervosa are discussed. Additional examination of the effects of estrogen on cognitive function in female subjects with anorexia nervosa is necessary.
Girls Who Disclose Sexual Abuse: Urogenital Symptoms and Signs After Genital Contact
Authors: DeLago Cynthia , Deblinger Esther , Schroeder Christine , Finkel Martin A.
Published: August 2008

BACKGROUND. Little information is available about idiosyncratic historical details provided by sexually abused girls, yet this information can help medical professionals diagnose sexual abuse.

OBJECTIVES. Our goals were to describe types and frequencies of urogenital symptoms/signs reported by girls who disclosed direct genital contact and to explore factors associated with this reporting.

METHODS. We reviewed 161 medical charts of 3- to 18-year-old girls who disclosed sexual abuse by direct genital contact for urogenital symptoms/signs, type of genital contact (oral, object, digital, or genital), time interval between last perpetrator contact and physical examination, age and sexual maturity at the time of last perpetrator contact, genital findings, and other medical diagnoses. Regression analyses were performed to determine factors that were most predictive of symptom/sign reporting.

RESULTS. Many of the girls reported multiple types of genital contact; 33% reported oral/object-genital contact, 72% reported digital-genital contact, and 55% reported genital-genital contact. Sixty percent of the girls reported experiencing ≥1 symptom/sign; 53% of the total sample had genital pain, 37% had dysuria, and 11% had genital bleeding. Symptoms/signs were highly associated with genital-genital contact: 48% of the girls reporting genital-genital contact had dysuria compared with 25% of girls not reporting genital-genital contact, 72% had genital pain/soreness compared with 32% not reporting genital-genital contact, and 16% had bleeding compared with 4% of those not reporting genital-genital contact. Using regression analysis, the strongest factor predictive of symptom reporting by the girls was genital-genital contact.

CONCLUSIONS. Sexually abused girls who experienced direct genital contact frequently reported symptoms related to the abusive episode. These symptoms were reported most frequently with genital-to-genital contact. This information sheds some light on the mechanism of injury leading to symptom reporting and can be used to further study symptoms/signs reported by sexually abused girls compared with the general population.
Minors as Living Solid-Organ Donors
Authors: Ross Lainie Friedman , Thistlethwaite J. Richard ,   and the Committee on Bioethics
Published: August 2008

In the past half-century, solid-organ transplantation has become standard treatment for a variety of diseases in children and adults. The major limitation for all transplantation is the availability of donors, and the gap between demand and supply continues to grow despite the increase in living donors. Although rare, children do serve as living donors, and these donations raise serious ethical issues. This clinical report includes a discussion of the ethical considerations regarding minors serving as living donors, using the traditional benefit/burden calculus from the perspectives of both the donor and the recipient. The report also includes an examination of the circumstances under which a minor may morally participate as a living donor, how to minimize risks, and what the informed-consent process should entail. The American Academy of Pediatrics holds that minors can morally serve as living organ donors but only in exceptional circumstances when specific criteria are fulfilled.
Care of the Adolescent Sexual Assault Victim
Authors: Kaufman Miriam ,   and the Committee on Adolescence
Published: August 2008

Sexual assault is a broad-based term that encompasses a wide range of sexual victimizations including rape. Since the American Academy of Pediatrics published its last policy statement on sexual assault in 2001, additional information and data have emerged about sexual assault and rape in adolescents and the treatment and management of the adolescent who has been a victim of sexual assault. This report provides new information to update physicians and focuses on assessment and care of sexual assault victims in the adolescent population.
A new neonatal primitive reflex: “The elbowing”. First experiences obtained on 543 Hungarian human newborns and infants
Authors: Szombati Éva , Molnár Zsuzsa , Szemenyeiné Szederháti Kamilla , Temesvári Péter
Published: August 2008

A szerzők 2007. március és 2008. március között 481 érett, valamint 62 koraszülött újszülöttön vizsgálták az érintettek újonnan leírt primitív reflexét, a könyöklés sajátosságait. Ezerháromszázhuszonkilenc vizsgálatot végeztek közvetlenül a születést követően, az újszülöttrészlegen, valamint a csecsemőosztályon, majd különböző életkorokban az első 6 élethónap során. Azt észlelték, hogy a reflex az első élethónap alatt a vizsgáltak 70–80%-ában megfigyelhető, majd fokozatosan csökkenő pozitív prevalencia kíséretében, 4–6 hónapos életkorra 25–30%-ban maradt kiváltható. Érett újszülöttek, valamint koraszülöttek vonatkozásában nem észleltek jelentős különbséget a reflex életkori prevalenciájának tárgyában. A reflex sajátosságainak további vizsgálata elsősorban gyermekgyógyászati kóros állapotokban, valamint utánkövetési célzattal is indokoltnak látszik.
Thermal and electrical transport along MWCNT arrays grown on Inconel substrates
Authors: Pal Sunil K. , Son Youngsuk , Borca-Tasciuc Theodorian , Borca-Tasciuc Diana-Andra , Kar Swastik , Vajtai Robert , Ajayan Pulickel M.
Published: August 2008

This work reports on thermal and electrical conductivities and interface resistances for transport along aligned multiwalled carbon nanotubes (CNT) films grown on a nickel superalloy (Inconel) substrate. The measured specific thermal resistance of the combined Inconel–CNT and indium–CNT interfaces is of the same order as reported for CNT and silicon or SiO2interfaces but much higher than theoretical predictions considering perfect contact between the tubes and substrate. Imperfect mechanical contact with the substrate and a large contribution caused by indium–CNT interface are thought to be mainly responsible for the high interface resistances and the low effective values of thermal and electrical conductivities. However, reported results represent an incentive for further research on CNT synthesis on metallic substrates for thermal management applications and pave the way for much easier integration of carbon nanotubes in electronic applications.
An improved energy method for determining Young’s modulus by instrumented indentation using a Berkovich tip
Authors: Ma Dejun , Ong Chung Wo , Zhang Taihua
Published: August 2008

We previously proposed a method for estimating Young’s modulus from instrumented nanoindentation data based on a model assuming that the indenter had a spherical-capped Berkovich geometry to take account of the bluntness effect. The method is now further improved by releasing the constraint on the tip shape, allowing it to have a much broader arbitrariness to range from a conical-tipped shape to a flat-ended shape, whereas the spherical-capped shape is just a special case in between. This method requires two parameters to specify a tip geometry, namely, a volume bluntness ratio Vr and a height bluntness ratio hr. A set of functional relationships correlating nominal hardness/reduced elastic modulus ratio (Hn/Er) and elastic work/total work ratio (We/W) were established based on dimensional analysis and finite element simulations, with each relationship specified by a set of Vr and hr. Young’s modulus of an indented material can be estimated from these relationships. The method was shown to be valid when applied to S45C carbon steel and 6061 aluminum alloy.
The more shearing, the thicker shear band and heat-affected zone in bulk metallic glass
Authors: Guo H. , Wen J. , Xiao N.M. , Zhang Z.F. , Sui M.L.
Published: August 2008

In a compression test for a Zr-based bulk metallic glass, a dominant shear band was preserved before fracture by a cylindrical stopper. A heat-affected zone (HAZ) ∼10 μm thick together with shear band was discovered in the center of the deformed sample by preferential ion milling. By using a low aspect ratio sample for compression, diverse micron-scaled HAZs among multiple shear bands were also revealed. Based on above experimental results and the isothermal source model, it was found that the thickness of shear band and its HAZ increased continuously with the progression of shear deformation.
Mechanism of anomalous eutectic formation in the solidification of undercooled Ni–Sn eutectic alloy
Authors: Li J.F. , Li X.L. , Liu L. , Lu S.Y.
Published: August 2008

Anomalous eutectics in the solidification structure of undercooled Ni–18.7 at.% Sn eutectic alloy were examined by optical metallography and electron backscattered diffraction. It was revealed that α–Ni particulates are, in principle, randomly distributed in the anomalous eutectics in the undercooling range investigated. Another eutectic phase, β–Ni3Sn, is well orientated at low undercoolings but gradually becomes inconsistent in orientation as undercooling increases, accompanied by an increasing number of grain boundaries in it. As the solidification structure changes from a mixture of anomalous eutectics plus lamellar eutectics to full anomalous eutectics beyond a critical undercooling of 130 K, however, misorientation in the β–Ni3Sn phase disappears completely from the measurement area. Partial remelting of the primary solid was proposed to be the origin of the anomalous eutectic formation, and quantitative analyses were performed.
Synthesis and elastic and mechanical properties of Cr2GeC
Authors: Amini Shahram , Zhou Aiguo , Gupta Surojit , DeVillier Andrew , Finkel Peter , Barsoum Michel W.
Published: August 2008

Herein we report on the synthesis and characterization of Cr2GeC, a member of the so-called Mn+1AXn(MAX) phase family of layered machinable carbides and nitrides. Polycrystalline samples were synthesized by hot pressing pure Cr, Ge, and C powders at 1350 °C at ∼45 MPa for 6 h. No peaks other than those associated with Cr2GeC and Cr2O3, in the form of eskolaite, were observed in the x-ray diffraction spectra. The samples were readily machinable and fully dense. The steady-state Vickers hardness was 2.5 ± 0.1 GPa. The Young’s moduli measured in compression and by ultrasound were 200 ± 10 and 245 ± 3 GPa, respectively; the shear modulus and Poisson’s ratio deduced from the ultrasound results were 80 GPa and 0.29, respectively. The ultimate compressive strength for a ∼20 μm grain size sample was 770 ± 30 MPa. Samples compressively loaded from 300 to ∼570 MPa exhibited nonlinear, fully reversible, reproducible, closed hysteretic loops that dissipated ∼20% of the mechanical energy, a characteristic of the MAX phases, in particular, and kinking nonlinear elastic solids, in general. The energy dissipated is presumably due to the formation and annihilation of incipient kink bands. The critical resolved shear stress of the basal plane dislocations—estimated from our microscale model—is ∼22 MPa. The incipient kink band and reversible dislocation densities, at the maximum stress of 568 MPa, are estimated to be 1.2 × 10−2μm−3and 1.0 × 1010cm−2, respectively.
Effect of zirconia content on electrical conductivities of mullite/zirconia composites measured by impedance spectroscopy
Authors: Ko Hong-Da , Lin Chien-Cheng , Chiu Kuo-Chuang
Published: August 2008

Electrical conductivities of various mullite/zirconia composites, as well as monolithic mullite and zirconia, were measured using AC impedance spectroscopy from 100 Hz to 10 MHz at temperatures ranging from 150 to 1300 °C. The impedance spectra of monolithic zirconia and mullite/zirconia composites showed two semicircles because of the contributions from grains and grain boundaries, while those of monolithic mullite had one semicircle due to the predominant contribution from grains. This indicates that the conductivities of the mullite/zirconia composites increased with zirconia content. The activation energies of electrical conduction in mullite and zirconia were about 65 and 79 kJ/mol, respectively, and those of mullite/zirconia composites were between 65 and 79 kJ/mol. While the conductivities of various composites at 1 MHz were fitted by Lichtenecker’s rule, the general mixing equation could be applied to the conductivities measured at 1 kHz.
High-resolution transmission electron microscopy (HRTEM) observation of dislocation structures in AlN thin films
Authors: Tokumoto Yuki , Shibata Naoya , Mizoguchi Teruyasu , Sugiyama Masakazu , Shimogaki Yukihiro , Yang Jung-Seung , Yamamoto Takahisa , Ikuhara Yuichi
Published: August 2008

The structure and configuration of threading dislocations (TDs) in AlN films grown on (0001) sapphire by metal–organic vapor phase epitaxy (MOVPE) were characterized by high-resolution transmission electron microscopy (HRTEM). It was found that the TDs formed in the films were mainly the perfect edge dislocations with the Burgers vector of b = ⅓〈11¯20〉. The majority of the edge TDs were not randomly formed but densely arranged in lines. The arrays of the edge TDs were mainly observed on the {11¯20} and {10¯10} planes. These two planes showed different configurations of TDs. TD arrays on both of these planes constituted low-angle boundaries. We suggest that these TDs are introduced to compensate for slight misorientations between the subgrains during the film growth.
Sol-gel synthesis of biocompatible silica-chitosan hybrids and hydrophobic coatings
Authors: Smitha S. , Shajesh P. , Mukundan P. , Warrier K.G.K.
Published: August 2008

A new organic–inorganic hybrid synthesized through a sol-gel process starting from alkoxysilane and chitosan is reported. Functionalization of the hybrid was effected through in situ hydrolysis–condensation reaction of methyltrimethoxysilane (MTMS) and vinyltrimethoxysilane (VTMS) in the reaction medium. The process yields highly transparent and hydrophobic silica–chitosan hybrids. The hybrid gel was investigated with respect to chemical modification, thermal degradation, hydrophobicity, and transparency under the ultraviolet-visible region. The extent of hydrophobicity had been tailored by varying the precursor ratio. SiO2–chitosan–MTMS hybrids showed a higher thermal stability than SiO2–chitosan–VTMS (SCV) hybrids with respect to hydrophobicity. Condensation of silsesquioxanes generated from the hydrolysis of MTMS and VTMS over the silica-chitosan particles impart hydrophobicity to the hybrid. The coatings of functionalized SiO2–chitosan precursor sol on glass substrates showed nearly 100% optical transmittance in the visible region. The present hybrid material may find application in optics and other industries.
Oxide nanodot arrays templated from polymer nano-channels via a novel vapor-transport-assisted wet chemistry process
Authors: Lin Yi-Feng , Tseng Wen-Hsien , Luan Hong-Zhi , Chen Liang-Yu , Lu Shih-Yuan , Ho Rong-Ming
Published: August 2008

A novel vapor-transport-assisted wet chemistry process was developed to fabricate oxide nanodot arrays from soft polymer templates. The feasibility and wide applicability of the proposed process was demonstrated with creation of high-density oxide nanodot arrays of TiO2, ZnO, and Co3O4. The present process not only avoids the over-growth problem inevitable in wet chemistry processes but also enables formation of oxide nanodots at low temperatures. The process can be readily extended to other compound systems in which the products can be formed through reactions of two reactants, one in liquid phase and the other in vapor phase.
Phase evolution in Ba–(Nd,Eu,Gd)–Cu–O-coated conductor films
Authors: Wong-Ng W. , Levin I. , Ritter J. , Cook L.P. , Liu G. , Otani M. , Vaudin M. , Lucas C. , Diwanji S.P. , Feenstra R.
Published: August 2008

Phases that are in equilibrium with BaR2CuO6+x (R=lanthanides and Y), such as the “green-phase” and “brown-phase” structural variants of BaR2CuO5 in bulk samples, are attractive choices for flux-pinning for coated conductor applications because of the guaranteed chemical stability. In films, high-temperature x-ray diffraction studies of Ba2RCu3O6+x superconductor deposited on SrTiO3 substrate using the trifluoroacetate solution method demonstrate that while BaNd2CuO5 (“brown-phase” structure) develops at 735 °C and 100 Pa pO2, neither BaGd2CuO5 nor Ba(Nd1/3Eu1/3Gd1/3)2CuO5 (both green-phase structure) form at these conditions. As a result, Ba2(Nd1/3Eu1/3Gd1/3)Cu3O6+x in thin films is in equilibrium with the brown-phase, and Ba2GdCu3O6+x is in equilibrium with Gd2O3 in the Ba–Gd–Cu–O system, in contrast to the bulk systems. Different phase relationships in the vicinity of the Ba2RCu3O6+x phase imply different phases are available for flux-pinning applications. These differences will need to be considered carefully in designing optimized superconducting coated conductors.
Upconversion luminescence properties of Li+-doped ZnWO4:Yb,Er
Authors: Luo Xi-xian , Cao Wang-he
Published: August 2008

Upconversion luminescence (UPL) characteristics and effects of Li+ion on the UPL of ZnWO4:Yb,Er polycrystalline phosphors were investigated. It was shown that introduction of Li+ions could reduce the calcination temperature by about 200 °C and increase the crystallinity of ZnWO4:Yb,Er by a liquid-phase sintering process via formation of Li2WO4and other intermediates. UPL efficiency is remarkably promoted by Li+ions. Moreover, the UPL spectrum of Li+-doped ZnWO4:Yb,Er presents a red shift, and the strongest peak position shifts from 553 to 559 nm. These can be attributed to a shift in the 4f level barycenter to lower energy, which results from lowering of the symmetry of the crystal field around Er3+.
Enhanced tensile ductility in an electrodeposited nanocrystalline copper
Authors: Wang Guoyong , Jiang Zhonghao , Zhang Hanzhuo , Lian Jianshe
Published: August 2008

A fully dense nanocrystalline (nc) Cu with mean grain size of 72 nm and a broad grain size distribution was synthesized by electrodeposition. Uniaxial tensile tests were done at different strain rates and room temperature. A very high strength of 1.04 G was obtained at strain rate of 0.1 s−1. The nearly perfect plasticity with a large strain of close to 20% was displayed at specific low strain rates of 4 × 10−5 to 10−4 s−1. With increasing strain rate, the nearly perfect plasticity disappeared. Strain rate sensitivity and activation volume of the nc Cu were estimated from the flow stress at a fixed strain of 1% and a strain rate change (jump) test. It was deduced from the high strain rate sensitivity exponent of 0.08 and small activation volume of 12b3 that both dislocation and grain boundary activities would take place in this nc Cu, which explained the nearly perfect plasticity observed in the tensile test.
Thermal stability of phases in a NiCoCrAlY coating alloy
Authors: Liang J.J. , Wei H. , Hou G.C. , Zheng Q. , Sun X.F. , Guan H.R. , Hu Z.Q.
Published: August 2008

The temperature dependence of the thermal stability in a NiCoCrAlY coating alloy was examined by experimental observation and thermodynamic modeling in the 400–1200 °C temperature range. The results indicated that the thermal stabilities of primary β–NiAl, β–NiAl/α–Cr eutectic, and γ–Ni were slightly temperature dependent, but those of γ′–Ni3Al, σ–(Cr,Co,Ni), and α–Cr were strongly temperature dependent in the annealed NiCoCrAlY specimens. The temperature dependence of the thermal stabilities among γ′–Ni3Al, σ–(Cr,Co,Ni), and α–Cr might be ascribed to the σ → α transformation at ∼1100 °C and the γ′ → γ transformation at ∼800 °C. Further, using Thermocalc associated with TTNi7 database, thermodynamic equilibria were calculated. The modeling results were compared with the experimental results and found to be in reasonable agreement with the experimental observations of β–NiAl, σ–(Cr,Co,Ni), and γ′–Ni3Al. Some deviations observed are discussed in the light of both limited availability of thermodynamic data and experimental problems.
Chemical characteristics of the passive surface films formed on newly developed Cu–Zr–Ag–Al bulk metallic glasses
Authors: Qin C.L. , Zhang W. , Zhang Q.S. , Asami K. , Inoue A.
Published: August 2008

In this paper, we systematically demonstrate the corrosion behavior and surface characteristics of a newly developed Cu36Zr48Ag8Al8 bulk metallic glass (BMG). The Cu36Zr48Ag8Al8 BMG exhibits excellent corrosion resistance in acidic and alkaline solutions without Cl− ions. The alloy is spontaneously passivated with a markedly low current density in 1 N H2SO4 solution. The formation of the bilayered passive film of the present alloy immersed in 1 N H2SO4 solution, which is composed mostly of Zr4+ cations in the exterior part and Zr4+- and Al3+-enriched cations in the inner part, could be responsible for the high corrosion resistance.
Keratinocyte Growth Factor Prevents Radiation Damage to Salivary Glands by Expansion of the Stem/Progenitor Pool
Authors: Lombaert Isabelle M.A. , Brunsting Jeanette F. , Wierenga Pieter K. , Kampinga Harm H. , de Haan Gerald , Coppes Robert P.
Published: August 2008

Irradiation of salivary glands during radiotherapy treatment of patients with head and neck cancer evokes persistent hyposalivation. This results from depletion of stem cells, which renders the gland incapable of replenishing saliva to produce acinar cells. The aim of this study was to investigate whether it is possible to expand the salivary gland stem/progenitor cell population, thereby preventing acinar cell depletion and subsequent gland dysfunction after irradiation. To induce cell proliferation, keratinocyte growth factor (ΔN23-KGF, palifermin) was administered to C57BL/6 mice for 4 days before and/or after local irradiation of salivary glands. Salivary gland vitality was quantified by in vivo saliva flow rates, morphological measurements, and a newly developed in vitro salisphere progenitor/stem cell assay. Irradiation of salivary glands led to a pronounced reduction in the stem cells of the tissues, resulting in severe hyposalivation and a reduced number of acinar cells. ΔN23-KGF treatment for 4 days before irradiation indeed induced salivary gland stem/progenitor cell proliferation, increasing the stem and progenitor cell pool. This did not change the relative radiation sensitivity of the stem/progenitor cells, but, as a consequence, an absolute higher number of stem/progenitor cells and acinar cells survived after radiation. Postirradiation treatment with ΔN23-KGF also improved gland function, and this effect was much more pronounced in ΔN23-KGF pretreated animals. Post-treatment with ΔN23-KGF seemed to act through accelerated expansion of the pool of progenitor/stem cells that survived the irradiation treatment. Overall, our data indicate that ΔN23-KGF is a promising drug to enhance the number of salivary gland progenitor/stem cells and consequently prevent radiation-induced hyposalivation.

Disclosure of potential conflicts of interest is found at the end of this article.
CD105-Positive Cells in Pulmonary Arterial Blood of Adult Human Lung Cancer Patients Include Mesenchymal Progenitors
Authors: Chiba Haruki , Ishii Genicihro , Ito Ta-Kashi , Aoyagi Kazuhiro , Sasaki Hiroki , Nagai Kanji , Ochiai Atsushi
Published: August 2008

Mesenchymal progenitor cells (MPCs) exhibit fibroblast-like morphology and are multipotent cells capable of differentiating into various mesenchymal tissues. Although MPCs have been found in adult bone marrow and umbilical cord blood, there is still controversy as to whether the MPCs are present in adult human blood. To determine whether they are, we cultured mononuclear cells (MNCs) from the pulmonary arterial blood of lung cancer patients. In 94% (29 of 31) of the cases, fibroblasts were expanded ex vivo and were differentiated into an osteogenic lineage or an adipogenic lineage, depending on the specific inducing medium used. These results indicated that pulmonary arterial blood (PA) in the vicinity of lung cancers contains MPCs (PA-MPCs). The cDNA profiles of PA-MPCs, MPCs derived from bone marrow (BM-MPCs), and lung tissue-derived fibroblasts were clustered with a hierarchical classification algorithm. The expression profiles of PA-MPCs (three cases) and BM-MPCs were clearly separated from those of the tissue-derived fibroblasts, and the profiles of the PA-MPCs from the two patients were separated from those of the BM-MPCs. To identify the source of the PA-MPCs, the MNCs from pulmonary arterial blood were exposed to anti-CD14, anti-CD105, anti-CD3, and anti-CD20 antibodies. CD105+ MNCs generated MPCs in eight of eight cases (100%), whereas CD14+, CD3+, and CD20+ mononuclear cells generated MPCs in three of five cases (60%), two of five cases (40%), and zero of three cases (0%), respectively. These findings are the first clear proof that the CD105+ MNC fraction in the pulmonary arterial blood of adult lung cancer patients includes MPCs.

Disclosure of potential conflicts of interest is found at the end of this article.
Embryonic Stem Cell Therapy of Heart Failure in Genetic Cardiomyopathy
Authors: Yamada Satsuki , Nelson Timothy J. , Crespo-Diaz Ruben J. , Perez-Terzic Carmen , Liu Xiao-Ke , Miki Takashi , Seino Susumu , Behfar Atta , Terzic Andre
Published: August 2008

Pathogenic causes underlying nonischemic cardiomyopathies are increasingly being resolved, yet repair therapies for these commonly heritable forms of heart failure are lacking. A case in point is human dilated cardiomyopathy 10 (CMD10; Online Mendelian Inheritance in Man #608569), a progressive organ dysfunction syndrome refractory to conventional therapies and linked to mutations in cardiac ATP-sensitive K+ (KATP) channel subunits. Embryonic stem cell therapy demonstrates benefit in ischemic heart disease, but the reparative capacity of this allogeneic regenerative cell source has not been tested in inherited cardiomyopathy. Here, in a Kir6.2-knockout model lacking functional KATP channels, we recapitulated under the imposed stress of pressure overload the gene-environment substrate of CMD10. Salient features of the human malignant heart failure phenotype were reproduced, including compromised contractility, ventricular dilatation, and poor survival. Embryonic stem cells were delivered through the epicardial route into the left ventricular wall of cardiomyopathic stressed Kir6.2-null mutants. At 1 month of therapy, transplantation of 200,000 cells per heart achieved teratoma-free reversal of systolic dysfunction and electrical synchronization and halted maladaptive remodeling, thereby preventing end-stage organ failure. Tracked using the lacZ reporter transgene, stem cells engrafted into host heart. Beyond formation of cardiac tissue positive for Kir6.2, transplantation induced cell cycle activation and halved fibrotic zones, normalizing sarcomeric and gap junction organization within remuscularized hearts. Improved systemic function induced by stem cell therapy translated into increased stamina, absence of anasarca, and benefit to overall survivorship. Embryonic stem cells thus achieve functional repair in nonischemic genetic cardiomyopathy, expanding indications to the therapy of heritable heart failure.

Disclosure of potential conflicts of interest is found at the end of this article.
Enhancing the Reliability and Throughput of Neurosphere Culture on Hydrogel Microwell Arrays
Authors: Cordey Myriam , Limacher Monika , Kobel Stefan , Taylor Verdon , Lutolf Matthias P.
Published: August 2008

The neurosphere assay is the standard retrospective assay to test the self-renewal capability and multipotency of neural stem cells (NSCs) in vitro. However, it has recently become clear that not all neurospheres are derived from a NSC and that on conventional cell culture substrates, neurosphere motility may cause frequent neurosphere “merging” [Nat Methods 2006;3:801–806; Stem Cells 2007;25:871–874]. Combining biomimetic hydrogel matrix technology with microengineering, we developed a microwell array platform on which NSC fate and neurosphere formation can be unequivocally attributed to a single founding cell. Using time-lapse microscopy and retrospective immunostaining, the fate of several hundred single NSCs was quantified. Compared with conventional neurosphere culture methods on plastic dishes, we detected a more than 100% increase in single NSC viability on soft hydrogels. Effective confinement of single proliferating cells to microwells led to neurosphere formation of vastly different sizes, a high percentage of which showed stem cell phenotypes after one week in culture. The reliability and increased throughput of this platform should help to better elucidate the function of sphere-forming stem/progenitor cells independent of their proliferation dynamics.

Disclosure of potential conflicts of interest is found at the end of this article.
Physiology of the pancreatic α-cell and glucagon secretion: role in glucose homeostasis and diabetes
Authors: Quesada Ivan , Tudurí Eva , Ripoll Cristina , Nadal Ángel
Published: August 2008

The secretion of glucagon by pancreatic α-cells plays a critical role in the regulation of glycaemia. This hormone counteracts hypoglycaemia and opposes insulin actions by stimulating hepatic glucose synthesis and mobilization, thereby increasing blood glucose concentrations. During the last decade, knowledge of α-cell physiology has greatly improved, especially concerning molecular and cellular mechanisms. In this review, we have addressed recent findings on α-cell physiology and the regulation of ion channels, electrical activity, calcium signals and glucagon release. Our focus in this review has been the multiple control levels that modulate glucagon secretion from glucose and nutrients to paracrine and neural inputs. Additionally, we have described the glucagon actions on glycaemia and energy metabolism, and discussed their involvement in the pathophysiology of diabetes. Finally, some of the present approaches for diabetes therapy related to α-cell function are also discussed in this review. A better understanding of the α-cell physiology is necessary for an integral comprehension of the regulation of glucose homeostasis and the development of diabetes.
Porosity, gas permeability, carbonation and their interaction in high-volume fly ash concrete
Authors: Lammertijn S. , De Belie N.
Published: August 2008

This paper describes the results of research into porosity, gas permeability and carbonation of high-volume fly ash (FA) concrete, including a literature review and comparison between models and experimental results. Four mixtures were made, each with a different FA replacement level—0, 35, 50 and 67 %—but with the same water-to-cementitious materials ratio. A vacuum saturation technique and a gas permeation experiment indicate that both porosity and gas permeability increase with increasing FA content. A reduction is noticed between 1 and 3 months for the FA mixtures owing to the pozzolanic reaction. No existing models seem to predict the porosity and gas permeability correctly for all mixtures. Carbonation tests show that the carbonation depth is considerably higher for the 50 and 67% FA mixtures at all ages compared to the ordinary Portland cement concrete. The Jiang model overestimates the carbonation depth for high-volume FA concrete significantly, while the Atiş models predict the depth rather well. Carbonation seems to have a negative effect on gas permeability, especially for the 50 and 67% mixtures.
Alveolar Bone Preservation in Extraction Sockets Using Non‐Resorbable dPTFE Membranes: A Retrospective Non‐Randomized Study
Authors: Hoffmann Oliver , Bartee Barry K. , Beaumont Christian , Kasaj Adrian , Deli Giorgio , Zafiropoulos Gregor‐Georg
Published: August 2008

Background: The aim of this study was to investigate the clinical regeneration of extraction sockets using high‐density polytetrafluoroethylene (dPTFE) membranes without the use of a graft material.

Methods: A total of 276 extraction sockets were evaluated in 276 subjects (151 males and 125 females; mean age, 50.2 years; age range: 24 to 73 years). After extraction, flaps were elevated and a dPTFE membrane was placed over the extraction site. The flaps were repositioned and sutured into place. Primary closure was not obtained over the membranes. The cemento‐enamel junctions of the adjacent teeth were used as reference points. Measurements were taken postextraction and 12 months after surgery in the same areas with the help of a stent and were defined as the distance from the reference points to the bone level. Hard tissue biopsies were taken from 10 representative cases during implant placement 12 months after socket preservation. The bone core samples were submitted for histologic evaluation. A stringent plaque‐control regimen was enforced in all subjects during the 12‐month observation period.

Results: A significant regeneration of the volume of sockets could be noted by histologic evaluation, indicating that the newly formed tissue in extraction sites was mainly bone. No influence of gender, smoking, age, or clinical bone level before treatment was found on the percentage of bone gain.

Conclusion: The use of dPTFE membranes predictably led to the preservation of soft and hard tissue in extraction sites.
Treatment Outcomes of Dental Flossing in Twins: Molecular Analysis of the Interproximal Microflora
Authors: Corby Patricia M.A. , Biesbrock Aaron , Bartizek Robert , Corby Andrea L. , Monteverde Robin , Ceschin Rafael , Bretz Walter A.
Published: August 2008

Background: The purpose of this study was to assess the effects of dental flossing on the microbial composition of interproximal plaque samples in matched twins.

Methods: The study was a two‐treatment, examiner‐masked, randomized, parallel‐group, controlled study. Fifty‐one twin pairs between 12 and 21 years of age were randomized to a 2‐week supervised and unsupervised treatment regimen consisting of tongue brushing and toothbrushing or tongue brushing and toothbrushing plus flossing. The reverse‐capture checkerboard hybridization assay was used to assess levels (abundance) of 26 microbial species in interproximal plaque samples collected from six sites per subject. An integrative computational predictive model estimated average changes in microbial abundance patterns of selected bacterial species from baseline to 2 weeks by comparing treatment groups.

Results: After the 2‐week study period, putative periodontal pathogens and cariogenic bacteria were overabundant in the group that did not floss compared to the group that performed flossing. Those included Treponema denticola, Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), Prevotella intermedia, Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), and Streptococcus mutans. Microbial species that are not consistent with the development of periodontal disease or dental caries were overabundant in the group that did floss compared to the non‐flossing group.

Conclusion: In a well‐matched twin cohort, tooth and tongue brushing plus flossing significantly decreased the abundance of microbial species associated with periodontal disease and dental caries after a 2‐week program.
Periostin Is Essential for the Integrity and Function of the Periodontal Ligament During Occlusal Loading in Mice
Authors: Rios H.F. , Ma D. , Xie Y. , Giannobile W.V. , Bonewald L.F. , Conway S.J. , Feng J.Q.
Published: August 2008

Background: The ability of the periodontal ligament (PDL) to absorb and distribute forces is necessary for periodontal homeostasis. This adaptive response may be determined, in part, by a key molecule, periostin, which maintains the integrity of the PDL during occlusal function and inflammation. Periostin is primarily expressed in the PDL and is highly homologous to βig‐H3 (transforming growth factor‐beta [TGF‐β] inducible gene). Cementum, alveolar bone, and the PDL of periostin‐null mice dramatically deteriorate following tooth eruption. The purpose of this study was to determine the role of periostin in maintaining the functional integrity of the periodontium.

Methods: The periodontia from periostin‐null mice were characterized followed by unloading the incisors. The effect of substrate stretching on periostin expression was evaluated using a murine PDL cell line. Real‐time reverse transcription‐polymerase chain reaction was used to quantify mRNA levels of periostin and TGF‐β. TGF‐β1 neutralizing antibodies were used to determine whether the effects of substrate stretching on periostin expression are mediated through TGF‐β.

Results: Severe periodontal defects were observed in the periostin‐null mice after tooth eruption. The removal of masticatory forces in periostin‐null mice rescue the periodontal defects. Periostin expression was increased in strained PDL cells by 9.2‐fold at 48 hours and was preceded by a transient increase in TGF‐β mRNA in vitro. Elevation of periostin in response to mechanical stress was blocked by the addition of 2.5 ng/ml neutralizing antibody to TGF‐β1, suggesting that mechanical strain activates TGF‐β to have potential autocrine effects and to increase periostin expression.

Conclusion: Mechanical loading maintains sufficient periostin expression to ensure the integrity of the periodontium in response to occlusal load.