bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Oesophageal Squamous Cell Carcinoma Progression by in vivo Targeting of Hyaluronan Synthesis
Authors: Twarock Sören , Freudenberger Till , Poscher Eva , Dai Guang , Jannasch Katharina , Dullin Christian , Alves Frauke , Prenzel Klaus , Knoefel Wolfram T , Stoecklein Nikolas H , Savani Rashmin C , Homey Bernhard , Fischer Jens W
Published: March 2011

Background

Oesophageal cancer is a highly aggressive tumour entity with at present poor prognosis. Therefore, novel treatment options are urgently needed. Hyaluronan (HA) is a polysaccharide present in the matrix of human oesophageal squamous cell carcinoma (ESCC). Importantly, in vitro ESCC cells critically depend on HA synthesis to maintain the proliferative phenotype. The aim of the present study is (1) to study HA-synthase (HAS) expression and regulation in human ESCC, and (2) to translate the in vitro results into a mouse xenograft model of human ESCC to study the effects of systemic versus tumour targeted HAS inhibition on proliferation and distribution of tumour-bound and stromal hyaluronan.

Methods

mRNA expression was investigated in human ESCC biopsies by semiquantitative real-time RT PCR. Furthermore, human ESCC were xenografted into NMRI nu/nu mice. The effects on tumour progression and morphology of 4-methylumbelliferone (4-MU), an inhibitor of HA-synthesis, and of lentiviral knock down of HA-synthase 3 (HAS3), the main HAS isoform in the human ESCC tissues and the human ESCC cell line used in this study, were determined. Tumour progression was monitored by calliper measurements and by flat-panel detector volume computed tomography (fpVCT). HA content, cellular composition and proliferation (Ki67) were determined histologically.

Results

mRNA of HAS isoform 3 (HAS3) was upregulated in human ESCC biopsies and HAS3 mRNA was positively correlated to expression of the epidermal growth factor (EGF) receptor. EGF was also proven to be a strong inductor of HAS3 mRNA expression in vitro. During the course of seven weeks, 4-MU inhibited progression of xenograft tumours. Interestingly, remodelling of the tumour into a more differentiated phenotype and inhibition of cell proliferation were observed. Lentiviral knockdown of HAS3 in human ESCC cells prior to xenografting mimicked all effects of 4-MU treatment suggesting that hyaluronan produced by ESCC is accountable for major changes in tumour environment in vivo.

Conclusions

Systemic inhibition of HA-synthesis and knockdown of tumour cell HAS3 cause decreased ESCC progression accompanied by tumour stroma remodelling and may therefore be used in novel approaches to ESCC therapy.
On the Forecasting of Ground-Motion Parameters for Probabilistic Seismic Hazard Analysis
Authors: Arroyo Danny , Ordaz Mario
Published: March 2011

It is well understood that the range of application for an empirical ground-motion prediction model is constrained by the range of predictor variables covered in the data used in the analysis. However, in probabilistic seismic hazard analysis (PSHA), the limits in the application of ground-motion prediction models (GMPMs) are often ignored, and the empirical relationships are extrapolated. In this paper, we show that this extrapolation leads to a quantifiable increment in the uncertainty of a GMPM when it is used to forecast a future value of a given intensity parameter. This increment, which is clearly of epistemic nature, depends on the adopted functional form, on the covariance matrix of the regression coefficients, on the used regression technique, and on the quality of the data set. In addition, through some examples using the database of the Next Generation of Ground-Motion Attenuation Models project and some currently favored functional forms we study the increment in the seismic hazard produced by the extrapolation of GMPMs.
Displacement-Based Preliminary Design of Tall Buildings Stiffened with a System of Buckling-Restrained Braces
Authors: Teran-Gilmore Amador , Coeto Guillermo
Published: March 2011

A displacement-based methodology for the preliminary design of a system of buckling-restrained braces is introduced. The methodology applies to the case of tall buildings, whose dynamic response is significantly influenced by global flexural drift mode and higher modes. The methodology is applied to the preliminary design of a 24-story building located in the Lake Zone of Mexico City. From the evaluation of the global mechanical characteristics of the building and of its seismic performance, it is concluded that the proposed methodology yields tall buildings that adequately satisfy predefined deterministic performance levels.
Association of GWAS-Based Candidate Genes with HDL-Cholesterol Levels before and after Bariatric Surgery in the Swedish Obese Subjects Study
Authors: Sarzynski Mark A. , Jacobson Peter , Rankinen Tuomo , Carlsson Björn , Sjöström Lars , Carlsson Lena M. S. , Bouchard Claude
Published: March 2011

Context and Objective:

The magnitude of weight loss-induced high-density lipoprotein cholesterol (HDL-C) changes may depend on genetic factors. We examined the associations of eight candidate genes, identified by genome-wide association studies, with HDL-C at baseline and 10 yr after bariatric surgery in the Swedish Obese Subjects study.

Methods:

Single-nucleotide polymorphisms (SNP) (n = 60) in the following gene loci were genotyped: ABCA1, APOA5, CETP, GALNT2, LIPC, LIPG, LPL, and MMAB/MVK. Cross-sectional associations were tested before (n = 1771) and 2 yr (n = 1583) and 10 yr (n = 1196) after surgery. Changes in HDL-C were tested between baseline and yr 2 (n = 1518) and yr 2 and 10 (n = 1149). A multiple testing corrected threshold of P = 0.00125 was used for statistical significance.

Results:

In adjusted multivariate models, CETP SNP rs3764261 explained from 3.2–4.2% (P < 10−14) of the variation in HDL-C at all three time points, whereas CETP SNP rs9939224 contributed an additional 0.6 and 0.9% at baseline and yr 2, respectively. LIPC SNP rs1077834 showed consistent associations across all time points (R2 = 0.4–1.1%; 3.8 × 10−6 < P < 3 × 10−3), whereas LPL SNP rs6993414 contributed approximately 0.5% (5 × 10−4 < P < 0.0012) at yr 2 and 10. In aggregate, four SNP in three genes explained 4.2, 6.8, and 5.6% of the HDL-C variance at baseline, yr 2, and yr 10, respectively. None of the SNP was significantly associated with weight loss-related changes in HDL-C.

Conclusions:

SNP in the CETP, LIPC, and LPL loci contribute significantly to plasma HDL-C levels in obese individuals, and the associations persist even after considerable weight loss due to bariatric surgery. However, they are not associated with surgery-induced changes in HDL-C levels.
Drosophila PI4KIIIalpha is required in follicle cells for oocyte polarization and Hippo signaling
Authors: Yan Yan , Denef Natalie , Tang Charm , Schüpbach Trudi
Published: March 2011

In a genetic screen we isolated mutations in CG10260, which encodes a phosphatidylinositol 4-kinase (PI4KIIIalpha), and found that PI4KIIIalpha is required for Hippo signaling in Drosophila ovarian follicle cells. PI4KIIIalpha mutations in the posterior follicle cells lead to oocyte polarization defects similar to those caused by mutations in the Hippo signaling pathway. PI4KIIIalpha mutations also cause misexpression of well-established Hippo signaling targets. The Merlin-Expanded-Kibra complex is required at the apical membrane for Hippo activity. In PI4KIIIalpha mutant follicle cells, Merlin fails to localize to the apical domain. Our analysis of PI4KIIIalpha mutants provides a new link in Hippo signal transduction from the cell membrane to its core kinase cascade.
Differential palmitoylation regulates intracellular patterning of SNAP25
Authors: Greaves Jennifer , Chamberlain Luke H.
Published: March 2011

SNAP25 regulates membrane fusion events at the plasma membrane and in the endosomal system, and a functional pool of the protein is delivered to recycling endosomes (REs) and the trans Golgi network (TGN) through an ARF6-dependent cycling pathway. SNAP25 is a peripheral membrane protein, and palmitoylation of a cluster of four cysteine residues mediates its stable association with the membrane. Here, we report that palmitoylation also determines the precise intracellular distribution of SNAP25, and that mutating single palmitoylation sites enhances the amount of SNAP25 at the RE and TGN. The farnesylated CAAX motif from Hras was ligated onto a SNAP25 mutant truncated immediately distal to the cysteine-rich domain. This construct displayed the same intracellular distribution as full-length SNAP25, and decreasing the number of cysteine residues in this construct increased its association with the RE and TGN, confirming the dominant role of the cysteine-rich domain in directing the intracellular distribution of SNAP25. Marked differences in the localisations of SNAP25-CAAX and Hras constructs, each with two palmitoylation sites, were observed, showing that subtle differences in palmitoylated sequences can have a major impact upon intracellular targeting. We propose that the cysteine-rich domain of SNAP25 is designed to facilitate the dual function of this SNARE protein at the plasma membrane and endosomes, and that dynamic palmitoylation acts as a mechanism to regulate the precise intracellular patterning of SNAP25.
Social Entrepreneurship: A Critique and Future Directions
Authors: Dacin M. Tina , Dacin Peter A. , Tracey Paul
Published: March 2011

Work on social entrepreneurship constitutes a field of study that intersects a number of domains, including entrepreneurial studies, social innovation, and nonprofit management. Scholars are beginning to contribute to the development of this new discipline through efforts that attempt to trace the emergence of social entrepreneurship as well as by comparing it to other organizational activities such as conventional entrepreneurship. However, as a nascent field, social entrepreneurship scholars are in the midst of a number of debates involving definitional and conceptual clarity, boundaries of the field, and a struggle to arrive at a set of relevant and meaningful research questions. This paper examines the promise of social entrepreneurship as a domain of inquiry and suggests a number of research areas and research questions for future study.
Organizational Learning: From Experience to Knowledge
Authors: Argote Linda , Miron-Spektor Ella
Published: March 2011

Organizational learning has been an important topic for the journal Organization Science and for the field. We provide a theoretical framework for analyzing organizational learning. According to the framework, organizational experience interacts with the context to create knowledge. The context is conceived as having both a latent component and an active component through which learning occurs. We also discuss current and emerging research themes related to components of our framework. Promising future research directions are identified. We hope that our perspective will stimulate future work on organizational learning and knowledge.
Evaluative Schemas and the Mediating Role of Critics
Authors: Hsu Greta , Roberts Peter W. , Swaminathan Anand
Published: March 2011

How do critics enable producers and consumers to come to mutually agreeable terms of trade? We propose that critics offer more guidance to those who set prices when their quality assessments are structured by clearer evaluative schemas. Schema clarity enables producers to accurately anticipate the quality assessments that critics will disseminate to the market. This allows their posted prices to center more faithfully on prevailing conceptions of quality. We then argue that the position of a producer within the market's social structure—in terms of its prior coverage, reputation, and niche width—influences the degree to which it is guided by clear evaluative schemas. We test these predictions in the market for U.S. wines. After elaborating a novel approach to inferring the clarity of evaluative schemas within different varietal categories, we demonstrate that list prices are less variable around expected levels when the schemas used to evaluate quality are clearer. Moreover, this effect is stronger among more relevant and more focused producers in each category.
Use of a fully automated immunoassay for celiac disease screening in a pediatric population
Authors: Ress Krista , Harro Jaanus , Uibo Oivi , Uibo Raivo
Published: March 2011

Background: Celiac disease (CD) is an immune-mediated disorder of the small bowel in which gluten and related cereal ingestion leads to chronic inflammation and damage to the small bowel mucosa in genetically susceptible individuals. The presence of IgA type tissue-transglutaminase antibodies (IgA-anti-tTG) in individuals without IgA deficiency is a highly-specific indicator of CD. We compared the accuracy of IgA-anti-tTG detection using a fully automated fluoroenzyme immunoassay (FEIA) with that of the standard enzyme-linked immunosorbent assay (ELISA) in a clinical setting.

Methods: We tested 1227 serum samples obtained from three groups of subjects: 1160 randomly selected schoolchildren, 36 pediatric patients with biopsy confirmed CD and 31 control children with biopsy confirmed normal small bowel mucosa. IgA-anti-tTG detection was compared using the FEIA method and the ELISA method, both of which use baculovirus-expressed recombinant human tissue-transglutaminase (tTG) as the antigen.

Results: Both tests identified pediatric patients with CD equally well in the random population (0.34% with CI: 0.09%–0.88%). Furthermore, both tests gave similar results for the CD group and the control group with normal small bowel mucosa (sensitivity: 90% and specificity: 100% for both assays).

Conclusions: The FEIA method is an equivalent substitute for the traditional ELISA for IgA-anti-tTG detection associated with CD in a random pediatric population.
Charakterisierung und Anwendung eines Doppler-Global-Velozimeters mit Laserfrequenzmodulation für die Untersuchung turbulenter Strömungen
Authors: Fischer Andreas
Published: March 2011

Zur Untersuchung komplexer turbulenter Strömungen sind berührungslose Geschwindigkeitsmessverfahren wünschenswert, die eine geringe Messunsicherheit (<1%), eine hohe Messrate (>10kHz) und eine Mehrpunktmessung gestatten. Um die Eignung und das Potential der Doppler-Global-Velozimetrie (DGV) hierfür aufzuzeigen, wurde eine Abschätzung der minimal erreichbaren Messunsicherheit auf Basis der Cramér-Rao-Ungleichung durchgeführt. Die abgeschätzte und mit einem optimierten Messsystem experimentell bestätigte Messunsicherheit beträgt minimal 0,03m/s und ist um eine Größenordnung kleiner als bei bisherigen DGV-Systemen. Zudem konnte durch den Einsatz eines schnellen Detektorarrays anstelle von üblicherweise genutzten CCD-Kameras die Messrate deutlich gesteigert werden. Im Ergebnis sind mit dem aufgebauten Messsystem erstmals berührungslose Messungen von Geschwindigkeitsspektren bis ca. 10kHz simultan an 25 Punkten möglich. Als Anwendungsbeispiele werden Messungen der Wirbel im Nachlauf eines quer angeströmten Zylinders und des Spaltwirbels bei einem ebenen Schaufelgitter vorgestellt. Das Messsystem kann zukünftig z. B. für die Erforschung von turbulenten Strömungen in Turbomaschinen genutzt werden, um deren Effizienz und Leistungsfähigkeit weiter zu steigern.
Vision restoration with implants in retinal degenerations
Authors: Kusnyerik Ákos , Resch Miklós , Roska Tamás , Karacs Kristóf , Gekeler Florian , Wilke Robert , Benav Heval , Zrenner Eberhart , Süveges Ildikó , Németh János
Published: March 2011

Up until now there has been no available treatment for diseases causing the permanent impairment of retinal photoreceptors. Currently the development of the retinal prostheses is the earliest to promise a result that can be implemented in the clinical treatment of these patients. Implants with different operating principles and in various stages of progress are presented in details, highlighting the characteristics, as well as the Hungarian aspects of the development. This survey intends to provide an overview on retinal prostheses, implantable in case of degenerative diseases of the retina, by reviewing and assessing the papers published in relevant journals and based on personal experience. Developments in microelectronics in recent years made it possible and proved to be feasible to replace the degenerated elements in the retina with electrical stimulation. Multiple comparable approaches are running simultaneously. Two types of these implants are directly stimulating the remaining living cells in the retina. Hitherto the finest resolution has been achieved with the subretinal implants. Although the epiretinal implant offer lower resolution, but requires shorter surgery for implantation. Retinal implants in certain retinal diseases are proved to be capable of generating vision-like experiences. A number of types of retinal implants can be expected to appear in clinical practice a few years after the successful conclusion of clinical trials. Orv. Hetil., 2011, 152, 537–545.
From project based sample collection to a biobank
Authors: Baranyai Zsolt , Mersich Tamás , Dede Kristóf , Besznyák István , Zaránd Attila , Teknős Dániel , Nagy Péter , Salamon Ferenc , Nagy Pál , Nagy Zsolt , Kótai Zsuzsanna , Szász Marcell , Lukács Lilla , Szállási Zoltán , Jósa Valéria , Jakab Ferenc
Published: March 2011

The research group takes samples for molecular genetical examinations from tumors removed during operations within ischemic time interval. Samples are stored in liquid nitrogen. Clinical data of these patients are recorded in an informatics system developed by the group. Patients are followed in an out-patient clinic set up for this purpose not financed by the National Health Insurance Fund. Tissue samples and follow up data are used to cooperate with molecular genetical laboratories. Orv. Hetil., 2011, 152, 606–609.
Stem cells in the amniotic fluid: the new chance of regenerative medicine
Authors: Joó József Gábor
Published: March 2011

Amniotic fluid has been used in prenatal diagnosis for more than decades. It yields a simple and reliable screening and diagnostic tool for a variety of congenital malformations and genetic diseases such as chromosomal aberrations, neural tube defects or storage diseases. Nowadays the widening knowledge provides evidence that amniotic fluid is not only a screening and diagnostic tool, but it may be also the source of the effective therapy of several congenital and adult disorders. A subset of cells, the so-called stem cells were found in the amniotic fluid as well as the placenta, and they proved to be capable of maintaining prolonged undifferentiated proliferation. Stem cells are able to differentiate into multiple tissue types, originating from the three germ layers. In the near future stem cells isolated from amniotic fluid or placenta and stored by cryopreservation may play a significant role in regenerative medicine. Congenital malformations as well as certain diseases in adults might be treated by tissues coming from progenitor cells of amniotic fluid stem cell origin. This study gives a summary of the main characteristics of amniotic fluid stem cells and it also presents important examples of their possible clinical application. Orv. Hetil., 2011, 152, 581–587.
Neurological and psychiatric manifestations of systemic lupus erythematosus and antiphospholipid syndrome
Authors: Aszalós Zsuzsa
Published: March 2011

Neurological or psychiatric symptoms are present in 60% of the cases with systemic lupus erythematosus. Direct lesions of nervous system are associated with the presence of antibodies, vasculitis, thrombosis and impairments mediated by cytokines. Damages caused by injuries of other organs or those due to therapy are known as indirect causes. In the complex pathogenesis the primary cause is neuronal dysfunction mediated by autoantibodies, vasculopathia and coagulopathia. Until now, more than 20 antibodies have been identified in association with damages of the nervous system. These antibodies may impair neurons or astrocytes and may promote thrombotic processes in vessels of the brain. Activation of endothelial cells and disturbance of blood-brain barrier are also pathogenic factors. In patients with systemic lupus erythematosus the most frequent psychiatric manifestations are organic psychosyndrome, particularly deterioration of cognitive functions, and depression, while the most common neurological syndromes are epilepsy and ischemic stroke. In the pathogenesis of antiphospholipid syndrome β2-glycoprotein I. plays the most important role; binding to its antibody the complex may interact with cells and modify haemostatic actions. The most frequent neurological manifestations of antiphospholipid syndrome are headache and ischemic stroke. Orv. Hetil., 2011, 152, 597–605.
Belatacept: A Novel Biologic for Maintenance Immunosuppression After Renal Transplantation
Authors: Martin Spencer T. , Tichy Eric M. , Gabardi Steven
Published: March 2011

In the past decade, the availability of new immunosuppressive maintenance therapies for use in solid organ transplantation has remained limited. Patients and clinicians have relied on immunosuppressive drugs that require a significant amount of therapeutic monitoring and are associated with a variety of adverse effects that affect both quality of life and allograft function. Belatacept is an investigational intravenous biologic agent for long‐term use in renal transplant recipients. The costimulatory pathway (signal 2) of T‐cell activation and proliferation is produced by stimulation of the T‐cell surface marker, CD28, and is essential to the immune system's cellular response and ability to recognize an allograft as foreign. Belatacept is a potent antagonist of B7–1 (CD80) and B7–2 (CD86) ligands present on antigen‐presenting cells that are responsible for activation of CD28. Recent phase III trials describe various dosing strategies of belatacept versus a standard cyclosporine protocol in recipients of both living‐ and deceased‐donor renal transplants, as well as in patients receiving kidneys transplanted from extended‐criteria donors. Compared with cyclosporine, belatacept has been shown to be noninferior in both patient and allograft survival rates. However, the rate of biopsy‐proven acute cellular rejection occurred more frequently in the belatacept groups. Also, compared with standard calcineurin‐based regimens, the risk of posttransplant lymphoproliferative disorder is increased in patients receiving belatacept, with the greatest risk in transplant recipients who are Epstein‐Barr virus seronegative before transplantation. However, this investigational immunosuppressive agent may avert common adverse effects experienced with standard immunosuppressive protocols including renal dysfunction, metabolic disorders, neurotoxicities, glucose abnormalities, and cosmetic effects. More data on the long‐term risks of belatacept are needed to better define its role as immunosuppressive maintenance therapy. Aside from an increased risk of malignancy, belatacept's limited adverse‐effect profile and convenient dosing strategy may make it an attractive option for immuno‐suppressive maintenance for both the patient and clinician.
Design of timber gridded shell structures
Authors: Harris Richard
Published: March 2011

Engineering and architecture are close disciplines with much overlap. Co-operation between design team partners to combine their experience leads to successful building structures. The paper discusses the key issues in the design of shells, giving methods of categorisation to aid communication within the design team. There has been a recent move towards freeform shells and the paper shows the necessity of working these up from clear rational parameters rather than relying on a computer-generated image alone. It shows the key material parameters that need to be addressed in grid shell design and shows how results from model tests and smaller-scale precedents can inform choice of material and size of structural elements. A review of recent shell structures includes references to timber gridshells (Downland, Savill) comparing their form-finding, modelling and construction techniques with the Pods, Scunthorpe (construction start September 2009)
Ductile moment-resistant steel–timber connections
Authors: Andreolli Mauro , Piazza Maurizio , Tomasi Roberto , Zandonini Riccardo
Published: March 2011

This paper investigates the mechanical characterisation of a joint, suitable for different configurations within a heavy timber frame, consisting of a wooden element connected to a steel stub by means of an end-plate and glued-in steel rods. This connection system has some interesting properties in terms of mechanical performance, versatility and prefabrication. An analytical model to predict the joint response in terms of its key parameters (e.g. failure mode, ultimate resistance, stiffness and rotation capacity) is proposed and validated through an extensive experimental programme. The component method, originally proposed for semi-rigid joints in steel frameworks, is adapted in order to set up a feasible general model for steel–timber joints, enabling application of the capacity design approach and offering the required ductility for applications in seismic zones. The tests carried out indicate satisfactory agreement between theoretical and experimental results: the reliable prediction of joint failure modes allows design of moment-resistant connections that can sustain high plastic deformation without brittle rupture, with a remarkable degree of global ductility and energy dissipation under alternate loading.
Long-term load test of a wood–concrete composite beam
Authors: To Lam , Fragiacomo Massimo , Balogh Jeno , Gutkowski Richard M.
Published: March 2011

This paper presents the results of an experimental investigation on the time-dependent behaviour of a layered wood–concrete composite beam specimen with notched shear key interlayer connections, under long-term static load and simultaneous exposure to naturally changing ambient environmental conditions including temperature and relative humidity. A creep test was performed to provide data about the behaviour of the wood–concrete composite beams for the first 5 month duration of the service life, while environmental conditions (relative humidity and temperature) were continuously monitored. A change in relative humidity makes the moisture content inside wood change, and the variations of moisture content in the wood create shrinkage/swelling in the wood layer. This variation also directly affects the mechanical properties of wood as well as causing the mechano-sorptive phenomenon in wood materials. In addition, an interconnected layered wood–concrete beam is an internally indeterminate structure; for example, as the wood and concrete have different thermal expansion coefficients, changing temperature in time creates thermal stress fields within the materials and deflections that vary with time. The test data presented were used to validate a three-dimensional numerical model implemented in the commercial software ABAQUS.
The photocatalytic enhancement of acrylic and PET solar water disinfection (SODIS) bottles
Authors: Carey J. M. , Perez T. M. , Arsiaga E. G. , Loetscher L. H. , Boyd J. E.
Published: March 2011

The solar water disinfection method (SODIS) was modified by the addition of a photocatalytic layer of titania on the interior surface of polyethylene terephthalate (PET) and acrylic bottles. Titania was solvent deposited on the interior of commercially available PET bottles, as well as bottles that were constructed from acrylic. Uncoated and titania-coated acrylic bottles removed 3,000,000–5,000,000 colony forming units per milliliter of K12 E. coli from 670 mL of contaminated water in 40 min of solar irradiance. After five hours of sunlight exposure, the concentration of 10 ppm methyl orange (a representative organic water contaminant), was reduced by 61% using the titania-coated acrylic bottles. The concentration of 87 ppb microcystin-LR (a representative algal toxin) was reduced by 70% after 7 hours of sunlight exposure in the titania-coated acrylic bottles. Acrylic is an effective alternative to PET for use in the SODIS method due to its greater UV transparency. The addition of titania to PET and acrylic bottles confers the ability to remove chemical contaminants in addition to inactivating microbiological contaminants.
Analysis and optimization of ammonia stripping using multi-fluid model
Authors: Yu Liang , Zhao Quanbao , Jiang Anping , Chen Shulin
Published: March 2011

Ammonia recovery from anaerobic digestion (AD) is a notably beneficial process for removing excess nitrogen, producing low cost fertilizer and enhancing odor abatement. A process was developed for nutrients recovery by integrating a simple and effective stripping process with AD system. To design, optimize and scale up this system, multi-fluid model was developed to simulate flow, mass transfer and reactions in the ammonia stripping tower. The mass and heat transfer and dissociation reactions were introduced into the CFD framework. The air/liquid ratio in each cell of the domain was considered in heterogeneous mass transfer rate. Good agreement between CFD modeling and experiments employing a packed bed was obtained on the effect of pH and temperature upon ammonia removal. It was found that the liquid to gas mass transfer rate became slower at the lower part of the packed bed with high air/liquid ratio and short liquid resident time, decreasing ammonia removal efficiency. The predicted contours at the lower part also showed decreases in liquid volume fraction and liquid temperature. These results suggest a great potential compensation to use the multi-section feed-in and recirculation for improving reactor performance.
Wastewater treatment in an anaerobic filter using small lava stones as filter media without temperature control
Authors: González-Martínez Simón , González-Barceló Óscar , Flores-Torres Carlos A.
Published: March 2011

For their simplicity and using cheap support materials, biological filtration of municipal wastewater can be adequate for developing countries where the legislation is not as strict as in other countries, like the members of the European Union. Biological filters are fixed biomass reactors where the suspended pollutants can easily be retained and the dissolved substances can be transformed by microbial activity. A pilot anaerobic filter was built and filled with lava stones sieved to obtain particles with an average size of 6 mm. The filter was fed with municipal wastewater during 220 days under hydraulic retention times (HRT) of 4.3 and 9.8 hours (average organic loading rates of 0.48 and 1.23 kgCOD/m3 d). The results show that the pH did not change significantly during the process. Lower organic loading rates (higher HRT) resulted in better COD and TSS removal rates. Average biogas composition showed methane to be 67% for the lower organic loading rate and 63% for the higher one. Backwashing with air for 5 minutes every 72 hours did not negatively affect the overall anaerobic process. Average TSS removal was 79 and 73% for the higher and lower HRT (lower and higher organic loading rates), respectively. The overall performance of the anaerobic filter is comparable with the reported values in the literature. The COD and TSS removal rates are slightly inferior to the ones reported in the literature for UASB reactors treating municipal wastewater.
Bioplastic production using wood mill effluents as feedstock
Authors: Ben M. , Mato T. , Lopez A. , Vila M. , Kennes C. , Veiga M. C.
Published: March 2011

Fibreboard production is one of the most important industrial activities in Galicia (Spain). Great amounts of wastewater are generated, with properties depending on the type of wood, treatment process, final product and water reusing, among others. These effluents are characterized by a high chemical oxygen demand, low pH and nutrients limitation. Although anaerobic digestion is one of the most suitable processes for the treatment, lately bioplastics production (mainly polyhydroxyalkanoates) from wastewaters with mixed cultures is being evaluated. Substrate requirements for these processes consist of high organic matter content and low nutrient concentration. Therefore, wood mill effluents could be a suitable feedstock. In this work, the possibility of producing bioplastics from to wood mill effluents is evaluated. First, wood mill effluent was converted to volatile fatty acids in an acidogenic reactor operated at two different hydraulic retention times of 1 and 1.5 d. The acidification percentage obtained was 37% and 42%, respectively. Then, aerobic batch assays were performed using fermented wood mill effluents obtained at different hydraulic retention times. Assays were developed using different cultures as inoculums. The maximum storage yield of 0.57 Cmmol/Cmmol was obtained when when the culture was enriched on a synthetic media.
Modular operation of membrane bioreactors for higher hydraulic capacity utilisation
Authors: Veltmann K. , Palmowski L. M. , Pinnekamp J.
Published: March 2011

Using data from 6 full-scale municipal membrane bioreactors (MBR) in Germany the hydraulic capacity utilisation and specific energy consumption were studied and their connexion shown. The average hydraulic capacity utilisation lies between 14% and 45%. These low values are justified by the necessity to deal with intense rain events and cater for future flow increases. However, this low hydraulic capacity utilisation leads to high specific energy consumption. The optimisation of MBR operation requires a better utilisation of MBR hydraulic capacity, particularly under consideration of the energy-intensive membrane aeration. A first approach to respond to large influent flow fluctuations consists in adjusting the number of operating modules. This is practised by most MBR operators but so far mostly with variable flux and constant membrane aeration. A second approach is the real-time adjustment of membrane aeration in line with flux variations. This adjustment is not permitted under current manufacturers’ warranty conditions. A further opportunity is a discontinuous operation, in which filtration takes place over short periods at high flux and energy for membrane aeration is saved during filtration pauses. The integration of a buffer volume is thereby indispensable. Overall a modular design with small units, which can be activated/ inactivated according to the influent flow and always operate under optimum conditions, enables a better utilisation of MBR hydraulic capacity and forms a solid base to reduce MBR energy demand.
Potential bioavailability of phosphorus in citrus orchard soil to Microcystis aeruginosa
Authors: Okubo Y. , Inoue T. , Yokota K. , Tsushima K.
Published: March 2011

Algal blooms in eutrophic water bodies are controlled by inputs of phosphorus (P) as the growth-limiting nutrient. Runoff particulate P associated with soil from fields often predominates among P fractions. Here, an algal bioassay to investigate the potential bioavailability of particulate P in soil collected from a citrus orchard was conducted. Microcystis aeruginosa was cultured in medium containing soil as the sole source of P. The P in the soil was not notably solubilized after autoclaving. Analyses of chlorophyll-a, suspended solids, particulate organic carbon, and particulate organic nitrogen showed that M. aeruginosa could utilize some of the P present in the soil, perhaps that in particulate form, but this form of P was not sufficient to maintain optimum growth.
Primary, Nonsyndromic Vesicoureteric Reflux and Nephropathy in Sibling Pairs
Authors: Lambert Heather J. , Stewart Aisling , Gullett Ambrose M. , Cordell Heather J. , Malcolm Sue , Feather Sally A. , Goodship Judith A. , Goodship Timothy H. J. , Woolf Adrian S.
Published: March 2011

Background and objectives

Primary vesicoureteric reflux (VUR) can coexist with reflux nephropathy (RN) and impaired renal function. VUR appears to be an inherited condition and is reported in approximately one third of siblings of index cases. The objective was to establish a DNA collection and clinical database from U.K. families containing affected sibling pairs for future VUR genetics studies. The cohort's clinical characteristics have been described.

Design, setting, participants, & measurements

Most patients were identified from tertiary pediatric nephrology centers; each family had an index case with cystography-proven primary, nonsyndromic VUR. Affected siblings had radiologically proven VUR and/or radiographically proven RN.

Results

One hundred eighty-nine index cases identified families with an additional 218 affected siblings. More than 90% were <20 years at the study's end. Blood was collected and leukocyte DNA extracted from all 407 patients and from 189 mothers and 183 fathers. Clinical presentation was established in 122; 92 had urinary tract infections and 16 had abnormal antenatal renal scans. RN was radiologically proven in 223 patients. Four patients had been transplanted; none were on dialysis. In 174 others aged >1 year, estimated GFR (eGFR) was calculated. Five had eGFR 15 to 59 and 48 had eGFR 60 to 89 ml/min per 1.73 m2. Values were lower in bilateral RN patients than in those with either unilateral or absent RN.

Conclusions

The large DNA collection from families with VUR and associated RN constitutes a resource for researchers exploring the most likely complex, genetic components predisposing to VUR and RN.
Outcomes of Simultaneous Pancreas-Kidney Transplantation in Type 2 Diabetic Recipients
Authors: Sampaio Marcelo Santos , Kuo Hung-Tien , Bunnapradist Suphamai
Published: March 2011

Background and objectives

Type 2 diabetic patients with end-stage renal disease may receive a simultaneous pancreas-kidney (SPK) transplant. However, outcomes are not well described. Risks for death and graft failure were examined in SPK type 2 diabetic recipients.

Design, setting, participants, & measurements

Using the United Network for Organ Sharing database, outcomes of SPK transplants were compared between type 2 and type 1 diabetic recipients. All primary SPK adult recipients transplanted between 2000 and 2007 (n = 6756) were stratified according to end-stage pancreas disease diagnosis (type 1: n=6141, type 2: n=582). Posttransplant complications and risks for death and kidney/pancreas graft failure were compared.

Results

Of the 6756 SPK transplants, 8.6% were performed in recipients with a type 2 diabetes diagnosis. Rates of delayed kidney graft function and primary kidney nonfunction were higher in the type 2 diabetics. Five-year overall and death-censored kidney graft survival were inferior in type 2 diabetics. After adjustment for other risk factors, including recipient (age, race, body weight, dialysis time, and cardiovascular comorbidities), donor, and transplant immune characteristics, type 2 diabetes was not associated with increased risk for death or kidney or pancreas failure when compared with type 1 diabetic recipients.

Conclusions

After adjustment for other risk factors, SPK recipients with type 2 diabetes diagnosis were not at increased risk for death, kidney failure, or pancreas failure when compared with recipients with type 1 diabetes.
A Comparison of Novel and Commonly-Used Indices of Insulin Sensitivity in African American Chronic Hemodialysis Patients
Authors: Hung Adriana M. , Sundell Mary B. , Egbert Phyllis , Siew Edward D. , Shintani Ayumi , Ellis Charles D. , Bian Aihua , Ikizler T. Alp
Published: March 2011

Background

Insulin resistance (IR) is highly prevalent in chronic hemodialysis (CHD) patients and is associated with poor cardiovascular outcomes. Hyperinsulinemic euglycemic glucose clamp (HEGC) is the gold standard for measuring IR. The comparison of commonly-used indirect indices of IR to HEGC has not been adequately performed in this population. Furthermore, the validity of newly proposed adipokine-based IR indices has not been explored.

Design, setting, participants, & measurements

This is an observational study performed in a single center, involving 12 prevalent CHD patients (50 ± 9 years old, 100% African American, 33% women, body mass index of 34.4 ± 7.6 kg/m2) who were studied three consecutive times. IR was assessed by HEGC (glucose-disposal rate [GDR]), homeostatic model assessment of IR (HOMA-IR), HOMA-IR corrected by adiponectin (HOMA-AD), leptin adiponectin ratio (LAR), QUICKI, and the McAuley's index at each time point.

Results

Eighty-three percent of the subjects displayed either glucose intolerance or overt insulin resistance by HEGC (GDR median, 5.71; interquartile range [IQR], 4.16, 6.81). LAR and HOMA-AD were the best correlates of IR measured by HEGC (r = −0.72, P < 0.001, and −0.67, P < 0.001), respectively. Fat percentage, interleukin-6, and adipokines (leptin, adiponectin, and resistin) were strongly associated with GDR. HEGC, LAR, and HOMA-AD had the best intraclass correlation coefficients.

Conclusion

IR is common in CHD patients. Adipokine-based indices are the best correlates of IR measurements by HEGC. HOMA-IR and QUICKI are reasonable alternatives. Use of these indices may allow better detection of alterations in insulin sensitivity in CHD patients.
Are the Creatinine-Based Equations Accurate to Estimate Glomerular Filtration Rate in African American Populations?
Authors: Delanaye Pierre , Mariat Christophe , Maillard Nicolas , Krzesinski Jean-Marie , Cavalier Etienne
Published: March 2011

Regarding the high prevalence of African American patients with ESRD, it is important to estimate the prevalence of early stages of chronic kidney disease in this specific population. Because serum creatinine concentration is dependent on muscular mass, an ethnic factor has to be applied to creatinine-based equations. Such ethnic factors have been proposed in the Modification of Diet in Renal Disease (MDRD) study equation and in the more recent Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. This review analyzes how these correction factors have been developed and how they have, or have not, been validated in external populations. It will be demonstrated that the African American factor in the MDRD study equation is accurate in African American chronic kidney disease (CKD) patients. However, it will be shown that this factor is probably too high for subjects with a GFR of ≥60 ml/min per 1.73 m2, leading to an underestimation of the prevalence of CKD in the global African American population. It will also be confirmed that this ethnic factor is not accurate in African (non-American) subjects. Lastly, the lack of true external validation of the new CKD-EPI equations will be discussed. Additional trials seem necessary in American African and African populations to better estimate GFR and apprehend the true prevalence of CKD in this population with a high renal risk.
Early Childhood Education in Pakistan: An International Slogan Waiting for National Attention
Authors: Ahmad Mumtaz
Published: March 2011

The World Conference on Education for All (1990) stated that learning begins at birth. The Dakar Framework for Action (2000) included the expansion and improvement of early childhood care and education as the first of six global goals. A number of countries have launched a variety of efforts to meet their global commitment to the development of care and education services for their young children. Pakistan is one of the signatories of the Education for All movement. However, Pakistan has not nationally agreed to implement a systematic scheme of early childhood education. Thus, Pakistan is considered ‘far behind’ in its progress towards meeting the goal of early childhood education. One strategy in some countries has been to use mothers in the education of the young. However, this policy option is problematic in Pakistan, since educating mothers to become literate and more knowledgeable about contemporary childrearing will require far more extensive efforts and resources than in other countries. This article is an effort to uncover the basic issues around early childhood education in Pakistan and to provide practicable, research-based suggestions regarding early childhood education.
Effect of Reduced Exposure Times on the Microhardness of Nanocomposites Polymerized by QTH and Second-generation LED Curing Lights
Authors: Marchan S. M. , White D. , Smith W. A. , Raman V. , Coldero L. , Dhuru V.
Published: March 2011

Clinical Relevance

Reduced polymerization times suggested with newer generation LED-curing lights may not be suitable to ensure sufficient conversion of all types of nanocomposites at depths of 2 mm.
Marginal, Internal Fit and Microleakage of Zirconia Infrastructures: An In-Vitro Study
Authors: Korkut L. , Cotert H. S. , Kurtulmus H.
Published: March 2011

Clinical Relevance

Fitting accuracy and microleakage dominate prognostic covariates for the long-term durability of crown restorations. The fitting accuracy and microleakage potential of zirconia infrastructures might be influenced by manufacturing technology.
Assessment of Tooth Sensitivity Using a Desensitizer Before Light-activated Bleaching
Authors: Reis A. , Dalanhol A. P. , Cunha T. S. , Kossatz S. , Loguercio A. D.
Published: March 2011

Clinical Relevance

The use of a desensitizing gel before light-activated in-office bleaching does not eliminate, but may reduce, the duration of this side effect.
Tolerances of joint gaps in Nd:YAG laser welded Ti-6Al-4V alloy with the addition of filler wire
Authors: Cao X. , Debaecker G. , Poirier E. , Marya S. , Cuddy J. , Birur A. , Wanjara P.
Published: March 2011

The effect of joint gap on the butt joint quality of Ti-6Al-4V alloy welded using a 4 kW Nd:yttrium aluminum garnet laser was evaluated in terms of the welding defects, microstructure, hardness, and tensile properties. The joint gap was proportionally filled using the filler wire with the compositions of the parent alloy. Fully penetrated welds without cracking were obtained up to a joint gap of 0.5 mm. The main defects observed in the welds were porosity and underfill. Specifically, the porosity area increased with increasing joint gap but remained less than 1% of the fusion zone area. Large underfill defects appeared in the weldments in the absence of a joint gap, but filler wire addition was observed to reduce this defect in the presence of a joint gap. The weld hardness decreased slightly with increasing joint gap, but the tensile properties were optimized at an intermediary gap size, probably due to the compromise between the low underfill (after the use of a filler wire) and a limited amount of porosity.
Picosecond laser-induced color centers in glass optics
Authors: Ashkenasi David , Lemke Andreas
Published: March 2011

It is known that ionizing radiation (x ray, gamma rays, and electrons) can induce numerous changes in the physical properties of glasses. The most obvious effect is visible coloration, which is caused by the accumulation of color centers (defects) in the irradiated volume. The application of such induced color centers has prompted a renewed interest since they can be generated and bleached reversibly. We present results on laser-induced color centers in different types of glasses using picosecond laser pulses. By applying different focusing optics the influence of changing focal length and energy flux density on the volume coloring effect has been analyzed. The changes in the optical transmission compared to the unperturbed state are significant.