bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strong ZrB2–SiC–WC Ceramics at 1600°C
Authors: Zou Ji , Zhang Guo‐Jun , Hu Chun‐Feng , Nishimura Toshiyuki , Sakka Yoshio , Vleugels Jef , Van der Biest Omer 
Published: January 2012

High temperature flexural strength of ZrB2–20 vol% SiC ceramics (ZS) up to 1600°C in high purity argon atmosphere was significantly improved by adding 5 vol% WC, but degraded when 5 vol% ZrC was added. ZrB2–20SiC–5WC ceramic (ZSW) has a very high strength (mean ± SD) of 675 ± 33 MPa at 1600°C, and also an elastic and transgranular fracture mode was observed. According to the analysis of the fracture modes and crack origins in ZSW ceramics, the improvement in strength above 1000°C was attributed to the removal of the oxide impurities from grain boundaries.
Structural Transitions and Microwave Dielectric Properties of Ba2−2xSr2xSmSbO6 Double Perovskites
Authors: Zhou Yuanyuan , Tian Cailan , Meng Siqin , Yue Zhenxing , Li Longtu 
Published: January 2012

Structures and microwave dielectric properties of Ba2−2xSr2xSmSbO6 (x = 0–1) ceramics were studied in this article. The phase transitions were analyzed using X‐ray powder diffraction, transmission electron microscopy, and Raman spectroscopy. All structures are proved to be ordered double perovskites, and a series of composition‐induced phase transitions are confirmed in the Ba2−2xSr2xSmSbO6 system via the sequence: Fm‐3m → I2/m → P21/n. Dielectric properties of the ceramics were measured at microwave frequencies (9–11 GHz). With the increase of x, the dielectric constant (εr) varies gradually from 20.7 to 16.0, the quality factor (Q × f) decreases first from 86 500 GHz to a minimum value at x = 0.4 and then increases slightly to 93 000 GHz, and the temperature coefficient of resonant frequency (τf) decreases from +25 to −50 ppm/°C. The relationships between composition, structure, and microwave dielectric properties in Ba2−2xSr2xSmSbO6 were discussed from the phase transition consideration.
Crystallographic Orientation Relationships Between SrTiO3 and Ruddlesden‐Popper Phase
Authors: Nien Chih‐Hung , Lu Hong‐Yang 
Published: January 2012

The crystalline phase mixture and microstructure of SrO‐excess SrTiO3 powder sintered at 1350°C/4 h is analyzed using X‐ray diffractometry (XRD), and scanning and transmission electron microscopy (SEM and TEM). Second phases represented by Ruddlesden–Popper Sr3Ti2O7 (RP2) and Sr4Ti3O10 (RP3) coexist with SrTiO3 (ST), consistent with the SrO–TiO2 phase equilibrium diagram. Some ST grains contain inter‐grown RP2 lamellae that permits analysis of the ST‐RP2 interface. The ST‐RP2 boundary shared by (001)ST and (001)RP2, although containing a lattice mismatch, is accommodated by long‐range elastic strain. The crystallographic orientation relationships of ST and RP2 at the interface are determined by selected area diffraction patterns (SADP) and described by transformation matrices. The crystallographic shear structure across the ST–RP boundary exhibiting the characteristic α‐fringe pattern can be represented by a fault vector R = 1/2(111)ST.
Directionally Solidified Al2O3–Er3Al5O12–ZrO2 Eutectic Ceramics with Interpenetrating or Nanofibrillar Microstructure: Residual Stress Analysis
Authors: Mesa María Cristina , Oliete Patricia B. , Larrea Ángel , Orera Víctor M. 
Published: January 2012

Directionally solidified Al2O3–Er3Al5O12–ZrO2 eutectic ceramic rods were fabricated by the laser‐assisted float zone method at growth rates from 25 to 1200 mm/h. The microstructure of the eutectic rods was studied as a function of the solidification rate and the three eutectic phases present in the material were identified by X‐ray and electron diffraction. The size of the eutectic phases measured in the plane perpendicular to the growth direction decreased when the growth rate increased. The microstructure showed a geometrical pattern morphology at low growth rates, an irregular faceted and interpenetrating morphology at medium rates, and a nanofibrillar morphology in samples solidified at 1200 mm/h. The fibrous pattern consisted of Al2O3 trifold shaped nano‐fibers surrounded by a jacket of Er‐stabilized ZrO2 (t < 50 nm) and embedded in a matrix of Er3Al5O12 of ~150 nm width. The residual stress in the alumina phase due to the thermal contraction mismatch between phases was determined by piezospectroscopy. It decreased with solidification rate from 262 MPa compressive at room temperature in the sample with the coarsest microstructure to 135 MPa in the sample solidified at 1200 mm/h. A linear behavior of the thermoelastic stresses was found in the 110–370 K temperature range. The stress relief temperature at which the stresses become zero markedly decreased with the interphase spacing. The decrease was attributed to thermal activation of diffusional creep in the nanometric ZrO2 phase.
The Wisdom of the Crowd in Combinatorial Problems
Authors: Yi Sheng Kung Michael , Steyvers Mark , Lee Michael D. , Dry Matthew J. 
Published: January 2012

AbstractThe “wisdom of the crowd” phenomenon refers to the finding that the aggregate of a set of proposed solutions from a group of individuals performs better than the majority of individual solutions. Most often, wisdom of the crowd effects have been investigated for problems that require single numerical estimates. We investigate whether the effect can also be observed for problems where the answer requires the coordination of multiple pieces of information. We focus on combinatorial problems such as the planar Euclidean traveling salesperson problem, minimum spanning tree problem, and a spanning tree memory task. We develop aggregation methods that combine common solution fragments into a global solution and demonstrate that these aggregate solutions outperform the majority of individual solutions. These case studies suggest that the wisdom of the crowd phenomenon might be broadly applicable to problem‐solving and decision‐making situations that go beyond the estimation of single numbers.
Middle Cerebellar Peduncles and Pontine T2 Hypointensities in ARSACS
Authors: Shimazaki Haruo , Takiyama Yoshihisa , Honda Junko , Sakoe Kumi , Namekawa Michito , Tsugawa Jun , Tsuboi Yoshio , Suzuki Chieko , Baba Masayuki , Nakano Imaharu 
Published: January 2012

ABSTRACTBACKGROUND AND PURPOSEMagnetic resonance imaging (MRI) of autosomal recessive spastic ataxia of Charlevoix‐Saguenay (ARSACS) cases in Quebec and Europe was reported to show linear hypointensities in T2‐weighted and Fluid Attenuated Inversion Recovery (FLAIR) images of the pons. We attempted to clarify the characteristics of the brain MRI findings in ARSACS cases.METHODSEight Japanese early‐onset ataxia patients with ARSACS confirmed molecularly were investigated. We performed neurological examination, SACS gene analysis, and MRI in the patients.RESULTSHypointensity lesions in the middle cerebellar peduncles in addition to the pons were observed in T2‐weighted and FLAIR images in all eight cases. Although superior cerebellar atrophy was seen in all cases, this MRI finding might not be specific for ARSACS. Upper cervical cord and medulla oblongata atrophy was not observed in 3 of the 7 patients examined.CONCLUSIONNot only pontine but also middle cerebellar peduncle hypointensity lesions observed in T2‐weighted and FLAIR images could be specific findings for ARSACS even in cases with variable clinical phenotypes.
The Optic Radiation and the Cerebellar Peduncles in Adolescents with First‐Admission Schizophrenia —A Diffusion Tensor Imaging Study
Authors: Henze Romy , Brunner Romuald , Thiemann Ulf , Parzer Peter , Klein Jan , Resch Franz , Stieltjes Bram 
Published: January 2012

ABSTRACTBACKGROUND AND PURPOSEPrevious studies have found gray matter alterations in the cerebellum and in the visual system in both adults and adolescents with schizophrenia. The present study was conducted to investigate whether white matter tracts associated with these regions are also affected in the early stages of the disorder.METHODSUsing a 1.5 Tesla magnetic resonance imaging (MRI) scanner and fiber tracking, the optic radiations and the middle cerebellar peduncles were examined in 13 adolescents with first‐admission schizophrenia and 13 healthy controls matched for age, gender, school type, and handedness.RESULTSPatients with schizophrenia displayed significantly decreased fractional anisotropy in the optic radiations, but no differences in the middle cerebellar peduncles compared to healthy controls.CONCLUSIONSOur findings of altered fiber integrity in the optic radiations in adolescents with schizophrenia are in line with gray matter alterations in the visual cortices previously reported in the same sample and are in accordance with other studies that found decreased fractional anisotropy in these regions. These findings support the view that the visual system plays an important role in the pathogenesis of schizophrenia and may enhance our understanding of associations between the visual cortex and symptoms of the disorder.
Impact of childhood life events and trauma on the course of depressive and anxiety disorders
Authors: Hovens J. G. F. M. , Giltay E. J. , Wiersma J. E. , Spinhoven P. , Penninx B. W. J. H. , Zitman F. G. 
Published: January 2012

Hovens JGFM, Giltay EJ, Wiersma JE, Spinhoven P, Penninx BWJH, Zitman FG. Impact of childhood life events and trauma on the course of depressive and anxiety disorders.Objective:  Data on the impact of childhood life events and childhood trauma on the clinical course of depressive and anxiety disorders are limited.Method:  Longitudinal data were collected from 1209 adult participants in the Netherlands Study of Depression and Anxiety (NESDA). Childhood life events and trauma at baseline were assessed with a semi‐structured interview and the clinical course after 2 years with a DSM‐IV‐based diagnostic interview and Life Chart Interview.Results:  At baseline, 18.4% reported at least one childhood life event and 57.8% any childhood trauma. Childhood life events were not predictive of any measures of course trajectory. Emotional neglect, psychological and physical abuse, but not sexual abuse, were associated with persistence of both depressive and comorbid anxiety and depressive disorder at follow‐up. Emotional neglect and psychological abuse were associated with a higher occurrence of a chronic course. Poor course outcomes were mediated mainly through a higher baseline severity of depressive symptoms.Conclusion:  Childhood trauma, but not childhood life events, was associated with an increased persistence of comorbidity and chronicity in adults with anxiety and/or depressive disorders. More unfavourable clinical characteristics at baseline mediate the relationship between childhood trauma and a poorer course of depressive and anxiety disorders.
Loss of E‐cadherin expression predicts disease recurrence and shorter survival in colorectal carcinoma
Authors: ELZAGHEID ADAM , BUHMEIDA ABDELBASET , LAATO MATTI , EL‐FAITORI OMRAN , SYRJÄNEN KARI , COLLAN YRJÖ , PYRHÖNEN SEPPO 
Published: January 2012

Elzagheid A, Buhmeida A, Laato M, El‐Faitori O, Syrjänen K, Collan Y, Pyrhönen S. Loss of E‐cadherin expression predicts disease recurrence and shorter survival in colorectal carcinoma. APMIS 2012; 120: 539–48.The traditional staging system is currently inadequate for identifying those patients with colorectal carcinoma (CRC) who carry a high risk for poor outcome. In this study, the expression of E‐cadherin was evaluated in CRC to determine its correlation with clinico‐pathological variables, and association with disease outcome in patients with long‐term follow‐up. The present series consisted of tissue samples obtained from 230 patients with stage I, II, III, or IV CRC treated during 1981–1990 at Turku University Hospital. Archival paraffin‐embedded samples were used to build up tissue microarray blocks, and E‐cadherin expression was assessed by immunohistochemistry using an automated staining system. Different grading systems were tested for expression of E‐cadherin. Fifty‐nine percent of all tumors were positive for E‐Cadherin. There was no significant correlation between E‐cadherin expression and gender (p < 0.83), localization (p < 0.45), tumor invasion (p < 0.32), or histologic grade (p < 0.41). However, loss of E‐cadherin expression was significantly associated with older age (p < 0.03) and lymph node involvement (p < 0.02), and with borderline significance with advanced stage (p < 0.09) and tumor metastasis (p < 0.09). In univariate (Kaplan–Meier) survival analysis, positive E‐cadherin significantly (p = 0.009) predicted longer disease‐free survival (DFS), and the same was true with disease‐specific survival (DSS) as well (p = 0.007). In multivariate (Cox) survival analysis, E‐cadherin retained its significance as independent predictor of DFS (HR = 1.56; 95% CI 1.01–2.42, p = 0.043), but not DSS. A sub‐group analysis revealed that E‐cadherin expression also predicts DFS (p < 0.01) and DSS (p < 0.04) in stage II CRC. Our results implicate the usefulness of E‐cadherin expression in predicting disease recurrence and long‐term survival in CRC.
Dual‐energy X‐ray absorptiometry and biochemical markers of bone turnover after autologous stem cell transplantation in myeloma
Authors: Laroche Michel , Lemaire Olivia , Bourin Philippe , Corre Jill , Gadelorge Mélanie , Roussel Muriel , Attal Michel 
Published: January 2012

AbstractObjectives:  To evaluate the effect of high‐dose chemotherapy (HDT) followed by autologous stem cell transplantation (ASCT) on bone turnover and bone mineral density in a cohort of 39 consecutive patients with multiple myeloma (MM).Methods:  Phosphorus and calcium parameters, bone turnover markers, and bone mineral density were studied. Timepoints were diagnosis (T1), just before ASCT (T2), 6 months (T3) after ASCT, and 1 yr (T4) after ASCT.Results:  No bone mineral loss was shown on dual‐energy X‐ray absorptiometry (DXA) at T1 (lumbar Z‐score −0.02, femoral neck Z‐score 0.77) or during follow‐up. Chronic vitamin D deficiency (25OHD3 11.7 ± 7.7 ng/mL at T1) and relative hyperparathyroidism from T2 to T4 were observed. In spite of this moderate hyperparathyroidism, serum C‐telopeptide of type I collagen (CTX) decreased significantly between T1 and T4. Bone alkaline phosphatase levels were low at diagnosis and showed no significant change after ASCT, unlike DKK1 levels that were high at diagnosis and decreased 6 months after ASCT in patients not previously treated with bisphosphonates.Conclusion:  Bone demineralization is moderate in multiple myeloma. ASCT induces a decrease in bone resorption but no changes in bone formation, remaining low despite the decrease in DKK1. Bone mineral loss, evaluated by DXA, is moderate in multiple myeloma. High‐dose chemotherapy followed by ASCT leads to decreased bone resorption but osteoblastic bone formation remains low, in spite of reduced circulating DKK1.
Hypoxia improves expansion potential of human cord blood–derived hematopoietic stem cells and marrow repopulation efficiency
Authors: Roy Sushmita , Tripathy Manjul , Mathur Nitin , Jain Asish , Mukhopadhyay Asok 
Published: January 2012

AbstractObjectives:  In bone marrow, hematopoietic stem cells (HSCs) reside in the most hypoxic endosteum niche, whereas the proliferating progenitors are located near the relatively oxygen‐rich vascular region. High oxygen tension is potentially detrimental to HSCs. The objective of this investigation was to compare cellular, functional, and molecular responses of human umbilical cord blood (UCB)‐derived hematopoietic stem and progenitor cells in culture under hypoxic and normoxic conditions.Methods:  CD133‐enriched UCB cells were cultured in growth factor containing serum‐free and serum‐supplemented medium under 5% O2 (hypoxia) or 21% O2 (normoxia) for 10 d. The phenotypes of expanded cells were analyzed by flow cytometry and the engraftability by SCID‐repopulation assay. The expression of hypoxia‐inducible factor (HIF)‐1α and some of its target genes was analyzed by real‐time RT‐PCR.Results:  In hypoxic culture, CD34+ CD38− cells were expanded about 27‐fold, which was significantly (P < 0.01) higher than that obtained in normoxic culture. Serum‐free culture did not support the growth of cells in the presence of 21% O2. Myeloid colony‐forming potential of cells was significantly (P < 0.05) increased in 5% O2 compared with 21% O2 culture. SCID‐repopulation efficiency seems to be better preserved in the cells cultured under hypoxic conditions. Hypoxia significantly (P < 0.05) induced the expression of HIF‐1α, vascular endothelial growth factor (VEGF), and ABCG2 genes and also upregulated CXCR4 receptor expression.Conclusions:  Low oxygen tension enhanced the proliferation of UCB‐derived HSC/progenitor cells and maintenance of SCID‐repopulating cells than normoxia. These expanded cells are expected to be beneficial in the patients who lack human leukocyte antigen (HLA)‐matched donors.
Development of an ELISA method for testing VWF ristocetin cofactor activity with improved sensitivity and reliability in the diagnosis of von Willebrand disease
Authors: Zhao Yiming , Gu Ying , Ji Shundong , Yang Jianfeng , Yu Ziqian , Ruan Changgeng 
Published: January 2012

AbstractObjectives:  Current methods in assessing von Willebrand factor (VWF) ristocetin cofactor activity for Von Willebrand’s disease (VWD) diagnosis include platelet agglutination by aggregometer or macroscopic slide examination, which are both time‐consuming with suboptimal interassay and intra‐assay variation. The purpose of this study is to establish a sensitive assay to detect VWF:RCo activity and evaluate its performance in VWD diagnosis.Methods:  We have established a sensitive VWF:RCo–ELISA method using a monoclonal antibody, SZ‐151, to immobilize the recombinant fragment of platelet glycoprotein Ib (rfGPIbα). VWF was captured by rfGPIbα in the presence of ristocetin, and then detected by HRP‐conjugated rabbit anti‐human VWF IgG. We tested the VWF:RCo level by this VWF:RCo–ELISA in 25 patients with different types of VWD and 36 healthy donors, and compared this method to a previously reported ELISA using 2D4 coating antibody.Results:  The sensitivity of VWF:RCo–ELISA was greatly improved with this assay (0.008 IU/dL compared to 0.031 IU/dL by 2D4 antibody). The interassay and intra‐assay coefficient variation were 8% and 12%, respectively. The mean values (ranges) of VWF:RCo in patients with type 1, type 2A, type 2B, type 2M, and type 3 of VWD and control group are 31.8 (22.3–56.9), 4.8 (0.6–11.8), 8.6 (1.6–19.7), 3.9 (1.0–6.8), 1.0 (0.5–1.6), and 91.5 (47.3–169.2) IU/dL, respectively. The corresponding ratios (ranges) of VWF:RCo/VWF:Ag are 0.83 (0.70–1.16), 0.27 (0.08–0.58), 0.31 (0.15–0.40), 0.18 (0.14–0.21), 0.52 (0.13–1.19), and 0.92 (0.62–1.26).Conclusion:  The VWF:RCo–ELISA using monoclonal anti‐rfGPIbα antibody SZ‐151 showed improved sensitivity and reliability in detecting VWF:RCo activity, and its clinical application would facilitate the diagnosis and classification of VWD.
Bisphosphonate‐induced osteonecrosis of the jaw in a rat model arises first after the bone has become exposed. No primary necrosis in unexposed bone
Authors: Abtahi Jahan , Agholme Fredrik , Sandberg Olof , Aspenberg Per 
Published: January 2012

J Oral Pathol Med (2012) 41: 494–499Background:  Bisphosphonate‐related osteonecrosis of the jaw was first described to start with sterile osteocyte death, similar to osteonecrosis in other parts of the skeleton. The typical chronic osteomyelitis was thought to develop when the dead bone was exposed to the oral cavity. An alternative explanation would be that the chronic osteomyelitis is a result of a bisphosphonate‐related inability of infected bony lesions to heal. We tested the hypothesis that primary osteocyte death is not necessary for the development of jaw osteonecrosis.Material and methods:  Forty rats were randomly allocated to four groups of 10. All animals underwent unilateral molar extraction and received the following drug treatments: Group I, controls with no drug treatment; Group II, 200 μg/kg per day alendronate; Groups III and IV, 200 μg/kg per day alendronate and 1 mg/kg of dexamethasone. All rats were euthanized after 14 days. Presence of osteonecrosis was determined by clinical and histological observations for groups I–III. For group IV, osteocyte viability at the contralateral uninjured site was examined using lactate dehydrogenase histochemistry (LDH).Results:  All animals in the alendronate plus dexamethasone groups developed large ONJ‐like lesions. Lactate dehydrogenase staining showed viable osteocytes in the contralateral jaw with no tooth extraction. No signs of osteonecosis were seen in the other groups.Conclusion:  Bisphosphonates and dexamethasone caused no osteocyte death in uninjured bone, but large ONJ‐like lesions after tooth extraction. Osteonecrosis of the jaw appears to arise first after the bone has been exposed. Possibly, bisphosphonates hamper the necessary resorption of bone that has become altered because of infection.
Myogenic capacity of muscle progenitor cells from head and limb muscles
Authors: Grefte Sander , Kuijpers Mette A.R. , Kuijpers‐Jagtman Anne M. , Torensma Ruurd , Von den Hoff Johannes W. 
Published: January 2012

Grefte S, Kuijpers MAR, Kuijpers‐Jagtman AM, Torensma R, Von den Hoff JW. Myogenic capacity of muscle progenitor cells from head and limb muscles.

Eur J Oral Sci 2012; 120: 38–45. © 2012 Eur J Oral SciThe restoration of muscles in the soft palate of patients with cleft lip and/or palate is accompanied by fibrosis, which leads to speech and feeding problems. Treatment strategies that improve muscle regeneration have only been tested in limb muscles. Therefore, in the present study the myogenic potential of muscle progenitor cells (MPCs) isolated from head muscles was compared with that of limb muscles. Muscle progenitor cells were isolated from the head muscles and limb muscles of rats and cultured. The proliferation of MPCs was analysed by DNA quantification. The differentiation capacity was analysed by quantifying the numbers of fused cells, and by measuring the mRNA levels of differentiation markers. Muscle progenitor cells were stained to quantify the expression of paired box protein Pax 7 (Pax‐7), myoblast determination protein 1 (MyoD), and myogenin. Proliferation was similar in the head MPCs and the limb MPCs. Differentiating head and limb MPCs showed a comparable number of fused cells and mRNA expression levels of myosin‐1 (Myh1), myosin‐3 (Myh3), and myosin‐4 (Myh4). During proliferation and differentiation, the number of Pax‐7+, MyoD+, and myogenin+ cells in head and limb MPCs was equal. It was concluded that head and limb MPCs show similar myogenic capacities in vitro. Therefore, in vivo myogenic differences between those muscles might rely on the local microenvironment. Thus, regenerative strategies for limb muscles might also be used for head muscles.