bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of ceramic conversion layers containing Ca and P on AZ91D Mg alloys by plasma electrolytic oxidation
Authors: Yao Z. P. , Li L. L. , Liu X. R. , Jiang Z. H.
Published: April 2009

Oxide based ceramic conversion layers containing Ca and P were prepared on AZ91D Mg alloy by plasma electrolytic oxidation technique in Na2SiO3 and NaOH systems respectively. The conversion layers prepared in both systems were porous and grey white. The doping of Ca decreased the porosity of the conversion layers in Na2SiO3 system, while increasing the porosity of and the microcracks of the conversion layers in NaOH system. The conversion layer prepared in NaOH system was composed of MgO, and the one prepared in Na2SiO3 system was composed of Mg2SiO4 and MgO; P and Ca only existed in the form of amorphous state in the conversion layer. The doping of Ca decreased the relative content of P while increasing the relative content of Ca in both conversion layers. The ceramic conversion layers in both systems improved the corrosion resistance of the AZ91D Mg alloy in 0·9%NaCl solution by one or two orders of magnitude.
Influence of temperature on phase, microstructure and oxidation resistance of carbon/carbon composites modified by hydrothermal treatment
Authors: Huang J-F , Wang N-N , Cao L-Y , Wu J-P
Published: April 2009

Carbon/carbon (C/C) composites were modified by a hydrothermal treatment using phosphoric acid solution, B4C, SiC and Al2O3 powders as infiltration fillers. The influence of the hydrothermal treatment temperature on the phase, microstructure and anti-oxidation property of the as modified composites was investigated. The phase composition and microstructure of the modified composites before and after oxidation were characterised by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy techniques. Results show that the oxidation resistance of the C/C composites is effectively improved after modified by the hydrothermal treatment. The mass loss of the C/C composites modified at different hydrothermal temperatures increases parabolicly with increased oxidation time, while the relationship between hydrothermal temperature and mass loss of the modified C/C composites after oxidation at 700°C for 10 h reveals a linear dependence. The mass loss of the modified C/C composites is only 3·69×10−3 g cm−2, which is much lower than 141·55×10−3 g cm−2 of the non-modified C/C composites, after oxidised at 700°C in air for 10 h.
SiC/Cr–Al–Si/glass multilayer oxidation resistant coating for carbon/carbon composites
Authors: Huang M , Li K-Z , Li H-J , Fu Q-G , Wang Y
Published: April 2009

Multilayer oxidation resistant SiC/Cr–Al–Si/glass coating for C/C composites was prepared by a three step method of pack cementation, plasma spraying and slurry dipping. The phase composition, microstructure and oxidation resistance of multilayer SiC/Cr–Al–Si/glass coating were studied by XRD, SEM and isothermal oxidation test at 1773 K in air respectively. Double layer SiC/Cr–Al–Si coating consisting of Al3·21Cr0·47, Cr3Si and Al2O3 can protect C/C composites from oxidation for only 61 h due to its high porosity. When a layer of borosilicate glass doped with MoSi2 was coated on the surface of the as sprayed Cr–Al–Si coating, multilayers of SiC/Cr–Al–Si/glass coating were formed such that they can protect C/C composites from oxidation for 95 h with only 5·3% weight loss and the corresponding weight loss rate is only 0·92×10−4 g cm−2 h−1. The positive effect of the borosilicate glass coating on the oxidation resistance of the coating may be attributed to its own fluidity at high temperature.
Phase 3 study of dasatinib 140 mg once daily versus 70 mg twice daily in patients with chronic myeloid leukemia in accelerated phase resistant or intolerant to imatinib: 15-month median follow-up
Authors: Kantarjian Hagop , Cortes Jorge , Kim Dong-Wook , Dorlhiac-Llacer Pedro , Pasquini Ricardo , DiPersio John , Müller Martin C. , Radich Jerald P. , Khoury H. Jean , Khoroshko Nina , Bradley-Garelik M. Brigid , Zhu Chao , Tallman Martin S.
Published: April 2009

Dasatinib is the most potent BCR-ABL inhibitor, with 325-fold higher potency than imatinib against unmutated BCR-ABL in vitro. Studies have demonstrated the benefits of dasatinib 70 mg twice daily in patients with accelerated-phase chronic myeloid leukemia intolerant or resistant to imatinib. A phase 3 study compared the efficacy and safety of dasatinib 140 mg once daily with the current twice-daily regimen. Here, results from the subgroup with accelerated-phase chronic myeloid leukemia (n = 317) with a median follow-up of 15 months (treatment duration, 0.03-31.15 months) are reported. Among patients randomized to once-daily (n = 158) or twice-daily (n = 159) treatment, rates of major hematologic and cytogenetic responses were comparable (major hematologic response, 66% vs 68%; major cytogenetic response, 39% vs 43%, respectively). Estimated progression-free survival rates at 24 months were 51% and 55%, whereas overall survival rates were 63% versus 72%. Once-daily treatment was associated with an improved safety profile. In particular, significantly fewer patients in the once-daily group experienced a pleural effusion (all grades, 20% vs 39% P < .001). These results demonstrate that dasatinib 140 mg once daily has similar efficacy to dasatinib 70 mg twice daily but with an improved safety profile. This trial is registered at www.clinicaltrials.gov as #CA180-035.
Extranodal marginal zone lymphoma of the ocular adnexa
Authors: Stefanovic Alexandra , Lossos Izidore S.
Published: April 2009

Lymphomas of the ocular adnexa are a heterogeneous group of malignancies, composing approximately 1% to 2% of non-Hodgkin lymphomas (NHLs) and 8% of extranodal lymphomas. The most common subtype, accounting for up to 80% of cases of primary ocular adnexal lymphoma, is marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type. In the recent past, there have been significant advances in our understanding of the clinical characteristics, morphology and phenotype, etiology, pathogenesis, diagnosis, natural history, treatment approaches, outcome, and prognostic factors of this disease entity. Novel immunologic and molecular techniques have aided in the distinction between MALT lymphoma and other lymphoproliferative disorders and led to the identification of tissue markers of prognostic significance. Modern imaging modalities provide invaluable tools for accurate staging and treatment planning. Besides radiotherapy and chemotherapy, a variety of new treatment options have emerged in the management of patients with ocular adnexal MALT lymphoma, especially monoclonal antibody therapy and antibiotic therapy against Chlamydia psittaci, which has been associated with the pathogenesis of ocular adnexal lymphomas in some parts of the world. In this review, we present a state-of-the-art summary of ocular adnexal MALT lymphomas.
Impact of donor CMV status on viral infection and reconstitution of multifunction CMV-specific T cells in CMV-positive transplant recipients
Authors: Zhou Wendi , Longmate Jeff , Lacey Simon F. , Palmer Joycelynne M. , Gallez-Hawkins Ghislaine , Thao Lia , Spielberger Ricardo , Nakamura Ryotaro , Forman Stephen J. , Zaia John A. , Diamond Don J.
Published: April 2009

Reconstitution of cytomegalovirus (CMV)–specific CD8+ T cells is essential to the control of CMV infection in CMV-positive recipients (R+) after allogeneic hematopoietic stem cell transplantation (HCT). Six-color flow cytometry was used to assess the functional profile of CMV-specific CD8+ T cells in 62 of 178 R+ HCT recipients followed virologically for CMV reactivation. R+ recipients receiving grafts from CMV-negative donors (D−; D−/R+) reconstituted fewer multifunctional CD8+ T cells expressing tumor necrosis factor-α (TNF-α), macrophage inflammatory protein-1β (MIP-1β), and CD107 in addition to interferon-γ (IFN-γ), compared with D+/R+ recipients. Unlike monofunctional CD8+ T cells secreting IFN-γ, which were abundantly generated during CMV reactivation in D−/R+ recipients, the relative lack of multifunctional CD8+ T cells persisted until at least 1 year post-HCT. D−/R+ recipients were more likely to require recurrent and prolonged use of antivirals. These findings were robust to statistical adjustment for pretransplant factors, as well as for posttransplant factors including graft-versus-host disease (GVHD) and its treatment by steroids. These analyses suggest that D+/R+ transplants, on average, generate higher levels of multifunctional CMV-specific T cells and require less antiviral therapy compared with D−/R+ HCT recipients. These results highlight the benefit of D+ donors in improving outcomes of R+ HCT recipients by reducing the duration and recurrent need of antiviral treatment, aided by increased levels of multifunctional CMV-specific T cells.
Imaging of the diffusion of single band 3 molecules on normal and mutant erythrocytes
Authors: Kodippili Gayani C. , Spector Jeff , Sullivan Caitlin , Kuypers Frans A. , Labotka Richard , Gallagher Patrick G. , Ritchie Ken , Low Philip S.
Published: April 2009

Membrane-spanning proteins may interact with a variety of other integral and peripheral membrane proteins via a diversity of protein-protein interactions. Not surprisingly, defects or mutations in any one of these interacting components can impact the physical and biological properties on the entire complex. Here we use quantum dots to image the diffusion of individual band 3 molecules in the plasma membranes of intact human erythrocytes from healthy volunteers and patients with defects in one of their membrane components, leading to well-known red cell pathologies (hereditary spherocytosis, hereditary elliptocytosis, hereditary hydrocytosis, Southeast Asian ovalocytosis, and hereditary pyropoikilocytosis). After characterizing the motile properties of the major subpopulations of band 3 in intact normal erythrocytes, we demonstrate that the properties of these subpopulations of band 3 change significantly in diseased cells, as evidenced by changes in the microscopic and macroscopic diffusion coefficients of band 3 and in the compartment sizes in which the different band 3 populations can diffuse. Because the above membrane abnormalities largely arise from defects in other membrane components (eg, spectrin, ankyrin), these data suggest that single particle tracking of band 3 might constitute a useful tool for characterizing the general structural integrity of the human erythrocyte membrane.
dbSMR: a novel resource of genome-wide SNPs affecting microRNA mediated regulation
Authors: Hariharan Manoj , Scaria Vinod , Brahmachari Samir K
Published: April 2009

Background

MicroRNAs (miRNAs) regulate several biological processes through post-transcriptional gene silencing. The efficiency of binding of miRNAs to target transcripts depends on the sequence as well as intramolecular structure of the transcript. Single Nucleotide Polymorphisms (SNPs) can contribute to alterations in the structure of regions flanking them, thereby influencing the accessibility for miRNA binding.

Description

The entire human genome was analyzed for SNPs in and around predicted miRNA target sites. Polymorphisms within 200 nucleotides that could alter the intramolecular structure at the target site, thereby altering regulation were annotated. Collated information was ported in a MySQL database with a user-friendly interface accessible through the URL: http://miracle.igib.res.in/dbSMR.

Conclusion

The database has a user-friendly interface where the information can be queried using either the gene name, microRNA name, polymorphism ID or transcript ID. Combination queries using 'AND' or 'OR' is also possible along with specifying the degree of change of intramolecular bonding with and without the polymorphism. Such a resource would enable researchers address questions like the role of regulatory SNPs in the 3' UTRs and population specific regulatory modulations in the context of microRNA targets.
Identifying set-wise differential co-expression in gene expression microarray data
Authors: Cho Sung Bum , Kim Jihun , Kim Ju Han
Published: April 2009

Background

Previous differential coexpression analyses focused on identification of differentially coexpressed gene pairs, revealing many insightful biological hypotheses. However, this method could not detect coexpression relationships between pairs of gene sets. Considering the success of many set-wise analysis methods for microarray data, a coexpression analysis based on gene sets may elucidate underlying biological processes provoked by the conditional changes. Here, we propose a differentially coexpressed gene sets (dCoxS) algorithm that identifies the differentially coexpressed gene set pairs between conditions.

Results

dCoxS is a two-step analysis method. In each condition, dCoxS measures the interaction score (IS), which represents the expression similarity between two gene sets using Renyi relative entropy. When estimating the relative entropy, multivariate kernel density estimation was used to model gene-gene correlation structure. Statistical tests for the conditional difference between the ISs determined the significance of differential coexpression of the gene set pair. Simulation studies supported that the IS is a representative measure of similarity between gene expression matrices. Single gene coexpression analysis of two publicly available microarray datasets detected no significant results. However, the dCoxS analysis of the datasets revealed differentially coexpressed gene set pairs related to the biological conditions of the datasets.

Conclusion

dCoxS identified differentially coexpressed gene set pairs not found by single gene analysis. The results indicate that set-wise differential coexpression analysis is useful for understanding biological processes induced by conditional changes.
Non-replication of an association of CTNNBL1polymorphisms and obesity in a population of Central European ancestry
Authors: Vogel Carla IG , Greene Brandon , Scherag André , Müller Timo D , Friedel Susann , Grallert Harald , Heid Iris M , Illig Thomas , Wichmann H-Erich , Schäfer Helmut , Hebebrand Johannes , Hinney Anke
Published: April 2009

Background

A recent genome-wide association (GWA) study of U.S. Caucasians suggested that eight single nucleotide polymorphisms (SNPs) in CTNNBL1 are associated with obesity and increased fat mass. We analysed the respective SNPs in data from our previously published GWA for early onset obesity (case-control design), in GWA data from a population-based cohort of adults, and in an independent family-based obesity study. We investigated whether variants in CTNNBL1 (including rs6013029) and in three other genes (SH3PXD2B, SLIT3 and FLJ42133,) were associated with obesity.

Methods

The GWA studies were carried out using Affymetrix® SNP Chips with approximately 500,000 markers each. In the families, SNP rs6013029 was genotyped using the TaqMan® allelic discrimination assay. The German case-control GWA included 487 extremely obese children and adolescents and 442 healthy lean individuals. The adult GWA included 1,644 individuals from a German population-based study (KORA). The 775 independent German families consisted of extremely obese children and adolescents and their parents.

Results

We found no evidence for an association of the reported variants in CTNNBL1 with early onset obesity or increased BMI. Further, in our family-based study we found no evidence for over-transmission of the rs6013029 risk-allele T to obese children. Additionally, we found no evidence for an association of SH3PXD2B, SLIT3 and FLJ42133 variants in our two GWA samples.

Conclusion

We detected no confirmation of the recent association of variants in CTNNBL1 with obesity in a population of Central European ancestry.
Patient satisfaction with healthcare provided by family doctors: primary dimensions and an attempt at typology
Authors: Marcinowicz Ludmila , Chlabicz Slawomir , Grebowski Ryszard
Published: April 2009

Background

Patient satisfaction is a complex and difficult concept to measure, thus precluding the use of exclusively quantitative methods for its description. The purpose of this survey was firstly to identify particular healthcare dimensions that determine a patient's satisfaction or dissatisfaction; and secondly to attempt to typologise the patients' responses based on their evaluation of healthcare.

Methods

Using a qualitative research design, thirty-six in-depth interviews with patients of family physicians were conducted: four patients from each of 9 family practices in different regions of Poland were interviewed. The main outcome measure was factors associated with patient satisfaction/dissatisfaction.

Results

In their evaluations of their contacts with family doctors, the patients cited mostly issues concerning interpersonal relationships with the doctor. Nearly 40% of the statements referred to this aspect of healthcare, with nearly equal proportions of positive and negative comments. The second most frequent category of responses concerned contextual factors (21%) that related to conditions of medical service, with two-thirds of the evaluations being negative. Statements concerning the doctor's competencies (12.9%) and personal qualities (10.5%) were less common.

Conclusion

To improve the quality of healthcare, family doctors should take special care to ensure the quality of their interactions with patients.
Equity and coverage of insecticide-treated bed nets in an area of intense transmission of Plasmodium falciparum in Tanzania
Authors: Bernard Jubilate , Mtove George , Mandike Renata , Mtei Frank , Maxwell Caroline , Reyburn Hugh
Published: April 2009

Background

There is no clear consensus on the most sustainable and effective distribution strategy for insecticide treated bed nets (ITNs). Tanzania has been a leader in social marketing but it is still not clear if this can result in high and equitable levels of coverage.

Methods

A cluster-randomized survey of ITN and bed net ownership and use was conducted in a rural area exposed to intense Plasmodium falciparum transmission in NE Tanzania where ITN distribution had been subject to routine delivery of national strategies and episodic free distribution through local clinics. Data were collected on household assets to assess equity of ITN coverage and a rapid diagnostic test for malaria (RDT) was performed in all ages.

Results

Among 598 households in four villages the use of any or insecticidal bed nets in children less than five years of age was 71% and 54% respectively. However there was a 19.8% increase in the number of bed nets per person (p < 0.001) and a 13.4% increase in the number of insecticidal nets per person (p < 0.001) for each quintile increase in household asset score. The odds of being RDT-positive were reduced by more than half in the least poor compared to the poorest households (OR 0.49, 95% CI 0.35–0.70). Poorer households had paid less for their nets and acquired them more recently, particularly from non-commercial sources, and bed nets in the least poor households were less likely to be insecticidal compared to nets in the poorest households (OR 0.44, 95% CI 0.26–0.74).

Conclusion

Marked inequity persists with the poorest households still experiencing the highest risk of malaria and the lowest ITN coverage. Abolition of this inequity within the foreseeable future is likely to require mass or targeted free distribution, but risks damaging what is otherwise an effective commercial market.
High level expression of the anti-retroviral protein APOBEC3G is induced by influenza A virus but does not confer antiviral activity
Authors: Pauli Eva-K , Schmolke Mirco , Hofmann Henning , Ehrhardt Christina , Flory Egbert , Münk Carsten , Ludwig Stephan
Published: April 2009

Human APOBEC3G is an antiretroviral protein that was described to act via deamination of retroviral cDNA. However, it was suggested that APOBEC proteins might act with antiviral activity by yet other mechanisms and may also possess RNA deamination activity. As a consequence there is an ongoing debate whether APOBEC proteins might also act with antiviral activity on other RNA viruses. Influenza A viruses are single-stranded RNA viruses, capable of inducing a variety of antiviral gene products. In searching for novel antiviral genes against these pathogens, we detected a strong induction of APOBEC3G but not APOBEC3F gene transcription in infected cells. This upregulation appeared to be induced by the accumulation of viral RNA species within the infected cell and occurred in an NF-κB dependent, but MAP kinase independent manner. It further turned out that APOBEC expression is part of a general IFNβ response to infection. However, although strongly induced, APOBEC3G does not negatively affect influenza A virus propagation.
Torsion of right middle lobe after a right upper lobectomy
Authors: Chen Chih-Hao , Hung Tzu-Ti , Chen Tung-Ying , Liu Hung-Chang
Published: April 2009

Lobar torsion after lung resection is a quite rare complication. A 50-year-old woman presented typical features on chest radiographs and CT(computed tomography) scan of lobar torsion after a right upper lobectomy. After emergency lobectomy of right middle lobe, the patient recovered well and discharged 10 days after the second operation.
LRP1 shedding in human brain: roles of ADAM10 and ADAM17
Authors: Liu Qiang , Zhang Juan , Tran Hien , Verbeek Marcel M , Reiss Karina , Estus Steven , Bu Guojun
Published: April 2009

Background

The low-density lipoprotein receptor-related protein 1 (LRP1) plays critical roles in lipid metabolism, cell survival, and the clearance of amyloid-β (Aβ) peptide. Functional soluble LRP1 (sLRP1) has been detected in circulating human placenta; however, whether sLRP1 is also present in the central nervous system is unclear.

Results

Here we show that abundant sLRP1 capable of binding its ligands is present in human brain tissue and cerebral spinal fluid (CSF). Interestingly, the levels of sLRP1 in CSF are significantly increased in older individuals, suggesting that either LRP1 shedding is increased or sLRP1 clearance is decreased during aging. To examine potential effects of pathological ligands on LRP1 shedding, we treated MEF cells with Aβ peptide and found that LRP1 shedding was increased. ADAM10 and ADAM17 are key members of the ADAM family that process membrane-associated proteins including amyloid precursor protein and Notch. We found that LRP1 shedding was significantly decreased in MEF cells lacking ADAM10 and/or ADAM17. Furthermore, forced expression of ADAM10 increased LRP1 shedding, which was inhibited by ADAM-specific inhibitor TIMP-3.

Conclusion

Our results demonstrate that LRP1 is shed by ADAM10 and ADAM17 and functional sLRP1 is abundantly present in human brain and CSF. Dysregulated LRP1 shedding during aging could alter its function and may contribute to the pathogenesis of AD.
Changes in S-100 protein serum levels in survivors of out-of-hospital cardiac arrest treated with mild therapeutic hypothermia: a prospective, observational study
Authors: Derwall Matthias , Stoppe Christian , Brücken David , Rossaint Rolf , Fries Michael
Published: April 2009

Introduction

Knowledge about the influence of current neuroprotective interventions on prognostic markers after survival from cardiac arrest is lacking. This study aimed to investigate the effects of mild therapeutic hypothermia on the release of the astroglial protein S-100 after cardiopulmonary resuscitation (CPR) in survivors of out-of-hospital cardiac arrest.

Methods

This was a prospective, observational study performed during a two-year period, involving medical emergency services and five collaborating hospitals at the city of Aachen, Germany. Sixty-eight subjects were enrolled by the emergency physician on duty by taking blood samples after successful attempts at resuscitation with return of spontaneous circulation (ROSC), followed by samples at 6, 12, 24, 72 and 120 hours post ROSC by the appropriate intensive care unit staff. Depending on the decision of the attending physician, subjects were cooled down to 33°C (n = 37) for 24 hours or were held at 37°C (n = 31). Patients were tracked for estimating mortality and gross neurological outcome for 14 days.

Results

S-100 levels in patients not receiving mild therapeutic hypothermia (normothermia (NT)) showed equivalent numbers as compared with cooled patients (mild therapeutic hypothermia (MTH)) on baseline (NT = 1.38 μg/l versus MTH = 1.30 μg/l; P = 0.886). S-100 levels on baseline were significantly lower in patients with a good neurological outcome at 14 days after the event in comparison to their peers with adverse outcome (P = 0.014). Although the difference in S-100 levels of MTH patients with adverse or favourable neurological outcome reached statistical significance, it did not in NT patients.

Conclusions

Although the predictive power of S-100 levels were best on admission but not at later time points, MTH had no influence on S-100 serum levels in survivors of non-traumatic out-of-hospital cardiac arrest in the particular setting of this investigation.
Conservation of core gene expression in vertebrate tissues
Authors: Chan Esther T , Quon Gerald T , Chua Gordon , Babak Tomas , Trochesset Miles , Zirngibl Ralph A , Aubin Jane , Ratcliffe Michael JH , Wilde Andrew , Brudno Michael , Morris Quaid D , Hughes Timothy R
Published: April 2009

Background

Vertebrates share the same general body plan and organs, possess related sets of genes, and rely on similar physiological mechanisms, yet show great diversity in morphology, habitat and behavior. Alteration of gene regulation is thought to be a major mechanism in phenotypic variation and evolution, but relatively little is known about the broad patterns of conservation in gene expression in non-mammalian vertebrates.

Results

We measured expression of all known and predicted genes across twenty tissues in chicken, frog and pufferfish. By combining the results with human and mouse data and considering only ten common tissues, we have found evidence of conserved expression for more than a third of unique orthologous genes. We find that, on average, transcription factor gene expression is neither more nor less conserved than that of other genes. Strikingly, conservation of expression correlates poorly with the amount of conserved nonexonic sequence, even using a sequence alignment technique that accounts for non-collinearity in conserved elements. Many genes show conserved human/fish expression despite having almost no nonexonic conserved primary sequence.

Conclusions

There are clearly strong evolutionary constraints on tissue-specific gene expression. A major challenge will be to understand the precise mechanisms by which many gene expression patterns remain similar despite extensive cis-regulatory restructuring.
Sulfation of chondroitin sulfate proteoglycans is necessary for proper Indian hedgehog signaling in the developing growth plate
Authors: Cortes Mauricio , Baria Alexis T. , Schwartz Nancy B.
Published: April 2009

In contrast to the functional role of heparan sulfate proteoglycans(HSPGs), the importance of chondroitin sulfate proteoglycans (CSPGs) in modulating signaling pathways involving hedgehog proteins, wingless-related proteins and fibroblast growth factors remains unclear. To elucidate the importance of sulfated CSPGs in signaling paradigms required for endochondral bone formation, the brachymorphic (bm) mouse was used as a model for undersulfated CSPGs. The bm mouse exhibits a postnatal chondrodysplasia caused by a mutation in the phosphoadenosine phosphosulfate (PAPS) synthetase(Papss2) gene, leading to reduced levels of PAPS and undersulfated proteoglycans. Biochemical analysis of the glycosaminoglycan (GAG) content in bm cartilage via sulfate labeling and fluorophore-assisted carbohydrate electrophoresis revealed preferential undersulfation of chondroitin chains(CS) and normal sulfation of heparan sulfate chains. In situ hybridization and immunohistochemical analysis of bm limb growth plates showed diminished Indian hedgehog (Ihh) signaling and abnormal Ihh protein distribution in the extracellular matrix. Consistent with the decrease in hedgehog signaling, BrdU incorporation exhibited a significant reduction in chondrocyte proliferation. Direct measurements of Ihh binding to defined GAG chains demonstrated that Ihh interacts with CS, particularly chondroitin-4-sulfate. Furthermore,co-immunoprecipitation experiments showed that Ihh binds to the major cartilage CSPG aggrecan via its CS chains. Overall, this study demonstrates an important function for CSPGs in modulating Ihh signaling in the developing growth plate, and highlights the importance of carbohydrate sulfation in regulating growth factor signaling.
DORNRÖSCHENis a direct target of the auxin response factor MONOPTEROS in theArabidopsisembryo
Authors: Cole Melanie , Chandler John , Weijers Dolf , Jacobs Bianca , Comelli Petra , Werr Wolfgang
Published: April 2009

DORNRÖSCHEN (DRN), which encodes a member of the AP2-type transcription factor family, contributes to auxin transport and perception in the Arabidopsis embryo. Live imaging performed with transcriptional or translational GFP fusions shows DRN to be activated in the apical cell after the first zygotic division, to act cell-autonomously and to be expressed in single cells extending laterally from the apical shoot stem-cell zone at the position of incipient leaf primordia. Here, we show that the Auxin response factor (ARF) MONOPTEROS (MP) directly controls DRN transcription in the tips of the embryonic cotyledons,which depends on the presence of canonical Auxin response elements (AuxREs),potential ARF-binding sites flanking the DRN transcription unit. Chromatin immunoprecipitation experiments show that MP binds in vivo to two AuxRE-spanning fragments in the DRN promoter, and that MP is required for expression of DRN in cotyledon tips. Hence, DRNrepresents a direct target of MP and functions downstream of MP in cotyledon development.
Neuroepithelial cells require fucosylated glycans to guide the migration of vagus motor neuron progenitors in the developing zebrafish hindbrain
Authors: Ohata Shinya , Kinoshita Shigeharu , Aoki Ryo , Tanaka Hideomi , Wada Hironori , Tsuruoka-Kinoshita Sachiko , Tsuboi Takashi , Watabe Shugo , Okamoto Hitoshi
Published: April 2009

The molecular mechanisms by which neurons migrate and accumulate to form the neural layers and nuclei remain unclear. The formation of vagus motor nuclei in zebrafish embryos is an ideal model system in which to address this issue because of the transparency of the embryos and the availability of established genetic and molecular biological techniques. To determine the genes required for the formation of the vagus motor nuclei, we performed N-ethyl-N-nitrosourea-based mutant screening using a zebrafish line that expresses green fluorescent protein in the motor neurons. In wild-type embryos, the vagus motor neuron progenitors are born in the ventral ventricular zone, then migrate tangentially in the dorsolateral direction, forming the nuclei. However, in towhead(twdrw685) mutant embryos, the vagus motor neuron progenitors stray medially away from the normal migratory pathway and fail to stop in the right location. The twdrw685 mutant has a defect in the GDP-mannose 4,6 dehydratase (gmds) gene, which encodes a key enzyme in the fucosylation pathway. Levels of fucosylated glycans were markedly and specifically reduced in twdrw685mutant embryos. Cell transplantation analysis revealed that GMDS is not essential in the vagus motor neuron progenitors for correct formation of the vagus motor nuclei, but is required in the neuroepithelial cells that surround the progenitors. Together, these findings suggest that fucosylated glycans expressed in neuroepithelial cells are required to guide the migration of vagus motor neuron progenitors.
FGF-regulated BMP signaling is required for eyelid closure and to specify conjunctival epithelial cell fate
Authors: Huang Jie , Dattilo Lisa K. , Rajagopal Ramya , Liu Ying , Kaartinen Vesa , Mishina Yuji , Deng Chu-Xia , Umans Lieve , Zwijsen An , Roberts Anita B. , Beebe David C.
Published: April 2009

There are conflicting reports about whether BMP signaling is required for eyelid closure during fetal development. This question was addressed using mice deficient in BMP or TGFβ signaling in prospective eyelid and conjunctival epithelial cells. Genes encoding two type I BMP receptors, the type II TGFβ receptor, two BMP- or two TGFβ-activated R-Smads or the co-Smad Smad4 were deleted from the ocular surface ectoderm using Cre recombinase. Only mice with deletion of components of the BMP pathway had an`eyelid open at birth' phenotype. Mice lacking Fgf10 or Fgfr2 also have open eyelids at birth. To better understand the pathways that regulate BMP expression and function during eyelid development,we localized BMPs and BMP signaling intermediates in Fgfr2 and Smad4 conditional knockout (CKO) mice. We found that Fgfr2 was required for the expression of Bmp4, the normal distribution of Shh signaling and for preserving the differentiation of the conjunctival epithelium. FGF signaling also promoted the expression of the Wnt antagonist Sfrp1 and suppressed Wnt signaling in the prospective eyelid epithelial cells,independently of BMP function. Transcripts encoding Foxc1 and Foxc2, which were previously shown to be necessary for eyelid closure, were not detectable in Smad4CKO animals. c-Jun, another key regulator of eyelid closure, was present and phosphorylated in eyelid periderm cells at the time of fusion, but failed to translocate to the nucleus in the absence of BMP function. Smad4CKO mice also showed premature differentiation of the conjunctival epithelium, conjunctival hyperplasia and the acquisition of epidermal characteristics, including formation of an ectopic row of hair follicles in place of the Meibomian glands. A second row of eyelashes is a feature of human lymphedema-distichiasis syndrome, which is associated with mutations in FOXC2.
Start of the embryonic cell cycle is dually locked in unfertilized starfish eggs
Authors: Hara Masatoshi , Mori Masashi , Wada Tadashi , Tachibana Kazunori , Kishimoto Takeo
Published: April 2009

A key event in the oocyte-to-embryo transition is the start of the embryonic mitotic cell cycle. Prior to this start, the cell cycle in oocytes is generally arrested at a particular stage during meiosis, and the meiotic arrest is released by fertilization. However, it remains unclear how release from the meiotic arrest is implicated in the start of the embryonic cell cycle. To elucidate this link, we have used starfish eggs, in which G1 phase arrest occurs after completion of meiosis if the mature oocytes are not fertilized, and fertilization simply directs the start of the embryonic cell cycle. The starfish G1 arrest is known to rely on the Mos-MAPK-Rsk (p90 ribosomal S6 kinase) pathway, and inactivation of Rsk induces S phase in the absence of fertilization. However, here we show that this S phase is not followed by M phase when MAPK remains active, owing to poly(A)-independent repression of cyclin A and B synthesis. By contrast, inactivation of MAPK alone induces M phase, even when S phase is inhibited by constitutively active Rsk. Thus, there is a divergence of separate pathways downstream of MAPK that together block the start of the embryonic mitotic cycle. One is the previously known Rsk-dependent pathway that prevents S phase, and the other is a novel pathway that is not mediated by Rsk and that leads to prevention of the first mitotic M phase through suppression of protein synthesis of M phase cyclins. Release from such a `dual-lock' by fertilization results in the start of the embryonic cell cycle.
An investigation on springback/negative springback phenomena using finite element method and experimental approach
Authors: Rahmani B , Alinejad G , Bakhshi-Jooybari M , Gorji A
Published: April 2009

In sheet metal forming processes, one of the main problems is the occurrence of springback/negative springback which can be influenced by various factors. A number of research scientists have conducted valuable investigation on springback phenomenon. However, the negative springback problem has rarely been investigated. In this study, the effect of geometric and non-geometric parameters such as sheet thickness, sheet anisotropy, and punch tip radius on the springback/negative springback phenomena was investigated using the finite element method (FEM) and experiment in V-die bending of CK67 anisotropic steel sheet. The two approaches illustrated the occurrence of negative springback in smaller punch tip radii of the punch. Also, variations of springback and negative springback angle versus punch tip radius were shown. It was observed that increasing the sheet thickness results in a decrease in the springback and negative springback angle. Furthermore, it was shown that by increasing the bending orientation to the rolling direction, the amount of yield stress, springback, and negative springback angle increased.
Statistical modeling of deposition rate in twin-wire submerged arc welding
Authors: Sharma A , Arora N , Mishra B K
Published: April 2009

The present article offers statistical modeling of deposition rate in twin-wire submerged arc welding. ‘Best subset selection method’ and ‘Mallows criterion’ have been used for model development. The deposition rate has been experimentally measured under varying process parameters including welding current, welding voltage, welding speed, contact-tube-to-workpiece-distance, and wire-diameter. Models for two polarities — direct current electrode positive and direct current electrode negative — have been presented. The models have been validated and have been further confirmed with the data points other than that used for model development. The models have been checked for their predictability and also compared with the models developed with conventionally used technique. The developed models of deposition rate in twin-wire submerged arc welding can be used for practical purposes with admissible error in prediction and better predictability compared with conventional models. The effects of process parameters on the deposition rate have also been presented.
Semantic web in manufacturing
Authors: Khilwani N , Harding J A , Choudhary A K
Published: April 2009

Advances in manufacturing systems include attempts to create collaborative networks for enterprise integration and information interoperability. To achieve collaboration and sharing effectively, various networking technologies have been proposed in the literature. The web has emerged as a basic entity for interconnecting man and machine and almost all parts of the enterprise community are being reshaped to exploit the opportunities that it offers. Apart from web technology, there are various other tools and techniques that have attracted research communities for representing data in ways that both machines and humans can understand. Semantic web, the second-generation web technology, is enriched by machine-processable information to support the users in their tasks. This paper presents the vision of the semantic web and describes ontologies and associated metadata as the building blocks of the semantic web. It reviews the literature dealing with the application of the semantic web and ontology in the broad domain of manufacturing. First, brief details about key enablers, i.e. web services, semantic web, semantic services, and ontology, are presented. Then the implementation of these approaches in different sectors of manufacturing is discussed. A knowledge base for all the information resources concerned with the manufacturing domain is also built up in this paper. An ontology model for a knowledge base of information resources is designed in Protégé software, which can be used for storing and searching information about authors, journals, blogs, newspapers, and many other sources of information.
Enriching balancing information using the unbalance covariance matrix
Authors: Jiffri S , Garvey S D , Rix A I J
Published: April 2009

Traditionally, rotor balancing is performed based only on vibration readings from either a balancing machine or from a machine in which the rotor is being balanced in-situ. These readings cannot reflect the complete state of unbalance in the rotor. The reason for this is that higher frequency modes do not make a significant contribution to response in any one operating condition. The resolution of measuring instrumentation is always limited and, as demands grow for ever-improved balance quality, this instrumentation struggles more and more with reducing signal-to-noise ratios. When balance corrections are made to a rotor based only on these vibration readings, the components of unbalance that tend to excite only the higher modes of the original configuration can make a significant contribution to response if the properties of the stator change.

This article presents a novel approach to robust balancing. It relies on the use of additional information in the form of a rotor unbalance covariance matrix. In theory, this covariance matrix could be obtained if a large sample from the population of all rotors of this type could be tested in a very high-quality (and high-speed) balancing machine. This suggestion is impracticable in all real situations. However, it is entirely conceivable that modelling of the manufacturing processes used to create the rotor could deliver this covariance matrix. This article begins by illustrating how such a covariance matrix might be obtained from modelling and then goes on to explain how the information within the covariance matrix can be combined with a set of measurements from a specific rotor to provide an improved estimate of the actual state of unbalance on that rotor. Examples are included to demonstrate the proposed robust balancing method.
The computation of torsional, dynamic stresses
Authors: Whalley R , A-Ameer A
Published: April 2009

The torsional dynamics of spatially dispersed, mechanical, power transmission system models are considered. Distributed—lumped parameter modelling methods are employed in the analysis of configurations comprising rotors, bearings, and relatively slender shaft arrangements. Analysis procedures enabling the computation of the torsional shear stress and velocity response of these drive systems are outlined and block diagram representations are formulated. The transient characteristics for shaft—rotor arrangements following deterministic input changes are computed. Typical rotor—shaft assemblies are investigated, illustrating thereby the procedures involved. Graphical results and comparative studies are presented and the generality of the techniques detailed is commented upon.
An iterative scheme for axisymmetric supercavitating flow
Authors: Nouri N M , Eslamdoost A
Published: April 2009

This article presents a numerical investigation of axisymmetric supercavitating flow. It is assumed that such a flow field could be estimated by a potential flow that neglects the viscosity effects and rotational motion of the fluid and assumes the flow as an irrotational flow field. One of the most adequate methods for modelling potential fields is the boundary element method, which is employed in this article. A novel iterative scheme is used to capture the free surface of an axisymmetric supercavity. This numerical algorithm is based on updating an initial guess for the cavity's boundary; the convergence criterion is the pressure amount on the free surface of the cavity, which converges to a constant value. To obtain finite lengths for supercavities, a cavity closure model is applied. The results are in good agreement with similar analytical and numerical solutions as well as the existing experimental data for supercavities characteristic properties and the drag coefficient on cavitators. The present iterative numerical algorithm is reliable for predicting the characteristics of a supercavitating flow. Moreover, the feasibility of the cavity capturing in a flow field with low cavitation number is especially attractive.
A numerical study of the effect on flow structure and heat transfer of a rectangular winglet pair in a plate fin heat exchanger
Authors: Gupta M , Kasana K S , Vasudevan R
Published: April 2009

Longitudinal vortices have a great capability of disrupting the growth of boundary layers and bring about the heat transfer enhancement between the fluid and its neighbouring surface. The potential of a winglet pair type vortex generator for the heat transfer enhancement in a plate fin heat exchanger, with triangular fins as inserts, is numerically evaluated in this article. The rectangular winglet pair is mounted on the triangular fins. The numerical computations are performed by solving an unsteady, three-dimensional Navier—Stokes equation, and an energy equation by using the modified MAC method. Air is taken as the working fluid. This study shows the flow structure and the performance of the winglet pair in improving the heat transfer. The computations are performed at Re=200 and placing the winglet at an angle of attack, β=20°. The results show that the heat transfer is increased by 13 per cent, even at the exit, with the winglet pair. The heat transfer enhancement with a winglet pair for different Re=200—500 and Pr=0.71 and for varying heights of the winglet pair is also predicted.
Conditions for the planes of symmetry of an elastically supported rigid body
Authors: Jang S J , Choi Y J
Published: April 2009

Introducing the planes of symmetry into an oscillating rigid body suspended by springs simplifies the complexity of the equations of motion and decouples the modes of vibration into in-plane and out-of-plane modes. There have been some research results from the investigation into the conditions for planes of symmetry in which prior conditions for the simplification of the equations of motion are required. In this article, the conditions for the planes of symmetry that do not need prior conditions for simplification are presented. The conditions are derived from direct expansions of eigenvalue problems for stiffness and mass matrices that are expressed in terms of in-plane and out-of-plane modes and the orthogonality condition with respect to the mass matrix. Two special points, the planar couple point and the perpendicular translation point are identified, where the expressions for stiffness and compliance matrices can be greatly simplified. The simplified expressions are utilized to obtain the analytical expressions for the axes of vibration of a vibration system with planes of symmetry.
Downstream particle image velocimetry measurements of a circular cylinder—plate junction
Authors: Ozturk N A , Akcayoglu A , Sahin B
Published: April 2009

In the present investigation, special attention was given to the flow characteristics downstream of a circular cylinder mounted on a flat surface for Reynolds numbers of 4000 and 7000. A series of experiments were performed in successive end-view planes with the range of 0≤ XL/ d≤5 using the particle image velocimetry (PIV) technique in order to demonstrate characteristics of wake flow structure and interactions between the shear layers caused by shedding vortices and tails of the horseshoe vortex system emanating from the upstream base of the cylinder. The development and growth of primary vortices in the end-view planes caused by the interactions of core flow and wake flow regions along the inner face of the shedding shear layers were examined quantitatively. Finally, it was concluded that the PIV technique was also capable of providing accurate velocity readings in the end-view planes of the wake flow regions.