bluuebunny/crossref_metadata_2025 huggingface dataset:
Lung T Lymphocyte Trafficking and Activation during Ischemic Acute Kidney Injury
Authors: Lie Mihaela L. , White Laura E. , Santora Rachel J. , Park Jong M. , Rabb Hamid , Hassoun Heitham T.
Published: August 2012

Despite advances in renal replacement therapy, the mortality rate for acute kidney injury (AKI) remains unacceptably high, likely owing to extrarenal organ dysfunction. Kidney ischemia–reperfusion injury (IRI) activates cellular and soluble mediators that facilitate organ crosstalk and induce caspase-dependent lung apoptosis and injury through a TNFR1-dependent pathway. Given that T lymphocytes mediate local IRI in the kidney and are known to drive TNFR1-mediated apoptosis, we hypothesized that T lymphocytes activated during kidney IRI would traffic to the lung and mediate pulmonary apoptosis during AKI. In an established murine model of kidney IRI, we identified trafficking of CD3+ T lymphocytes to the lung during kidney IRI by flow cytometry and immunohistochemistry. T lymphocytes were primarily of the CD3+CD8+ phenotype; however, both CD3+CD4+ and CD3+CD8+ T lymphocytes expressed CD69 and CD25 activation markers during ischemic AKI. The activated lung T lymphocytes did not demonstrate an increased expression of intracellular TNF-α or surface TNFR1. Kidney IRI induced pulmonary apoptosis measured by caspase-3 activation in wild-type controls, but not in T cell-deficient (Tnu/nu) mice. Adoptive transfer of murine wild-type T lymphocytes into Tnu/nu mice restored the injury phenotype with increased cellular apoptosis and lung microvascular barrier dysfunction, suggesting that ischemic AKI-induced pulmonary apoptosis is T cell dependent. Kidney–lung crosstalk during AKI represents a complex biological process, and although T lymphocytes appear to serve a prominent role in the interorgan effects of AKI, further experiments are necessary to elucidate the specific role of activated T cells in modulating pulmonary apoptosis.
Genetically Driven Target Tissue Overexpression of CD40: A Novel Mechanism in Autoimmune Disease
Authors: Huber Amanda K. , Finkelman Fred D. , Li Cheuk Wun , Concepcion Erlinda , Smith Eric , Jacobson Eric , Latif Rauf , Keddache Mehdi , Zhang Weijia , Tomer Yaron
Published: August 2012

The CD40 gene, an important immune regulatory gene, is also expressed and functional on nonmyeloid-derived cells, many of which are targets for tissue-specific autoimmune diseases, including β cells in type 1 diabetes, intestinal epithelial cells in Crohn’s disease, and thyroid follicular cells in Graves’ disease (GD). Whether target tissue CD40 expression plays a role in autoimmune disease etiology has yet to be determined. In this study, we show that target tissue overexpression of CD40 plays a key role in the etiology of autoimmunity. Using a murine model of GD, we demonstrated that thyroidal CD40 overexpression augmented the production of thyroid-specific Abs, resulting in more severe experimental autoimmune GD (EAGD), whereas deletion of thyroidal CD40 suppressed disease. Using transcriptome and immune–pathway analyses, we showed that in both EAGD mouse thyroids and human primary thyrocytes, CD40 mediates this effect by activating downstream cytokines and chemokines, most notably IL-6. To translate these findings into therapy, we blocked IL-6 during EAGD induction in the setting of thyroidal CD40 overexpression and showed decreased levels of thyroid stimulating hormone receptor-stimulating Abs and frequency of disease. We conclude that target tissue overexpression of CD40 plays a key role in the etiology of organ-specific autoimmune disease.
Natural IgM Mediates Complement-Dependent Uptake of Francisella tularensis by Human Neutrophils via Complement Receptors 1 and 3 in Nonimmune Serum
Authors: Schwartz Justin T. , Barker Jason H. , Long Matthew E. , Kaufman Justin , McCracken Jenna , Allen Lee-Ann H.
Published: August 2012

A fundamental step in the life cycle of Francisella tularensis is bacterial entry into host cells. F. tularensis activates complement, and recent data suggest that the classical pathway is required for complement factor C3 deposition on the bacterial surface. Nevertheless, C3 deposition is inefficient and neither the specific serum components necessary for classical pathway activation by F. tularensis in nonimmune human serum nor the receptors that mediate infection of neutrophils have been defined. In this study, human neutrophil uptake of GFP-expressing F. tularensis strains live vaccine strain and Schu S4 was quantified with high efficiency by flow cytometry. Using depleted sera and purified complement components, we demonstrated first that C1q and C3 were essential for F. tularensis phagocytosis, whereas C5 was not. Second, we used purification and immunodepletion approaches to identify a critical role for natural IgM in this process, and then used a wbtA2 mutant to identify LPS O-Ag and capsule as prominent targets of these Abs on the bacterial surface. Finally, we demonstrate using receptor-blocking Abs that CR1 (CD35) and CR3 (CD11b/CD18) acted in concert for phagocytosis of opsonized F. tularensis by human neutrophils, whereas CR3 and CR4 (CD11c/CD18) mediated infection of human monocyte-derived macrophages. Altogether, our data provide fundamental insight into mechanisms of F. tularensis phagocytosis and support a model whereby natural IgM binds to surface capsular and O-Ag polysaccharides of F. tularensis and initiates the classical complement cascade via C1q to promote C3 opsonization of the bacterium and phagocytosis via CR3 and either CR1 or CR4 in a phagocyte-specific manner.
Protective Role of Commensals against Clostridium difficile Infection via an IL-1β–Mediated Positive-Feedback Loop
Authors: Hasegawa Mizuho , Kamada Nobuhiko , Jiao Yizu , Liu Meng Zhen , Núñez Gabriel , Inohara Naohiro
Published: August 2012

Clostridium difficile is a Gram-positive obligate anaerobic pathogen that causes pseudomembranous colitis in antibiotic-treated individuals. Commensal bacteria are known to have a significant role in the intestinal accumulation of C. difficile after antibiotic treatment, but little is known about how they affect host immunity during C. difficile infection. In this article, we report that C. difficile infection results in translocation of commensals across the intestinal epithelial barrier that is critical for neutrophil recruitment through the induction of an IL-1β–mediated positive-feedback loop. Mice lacking ASC, an essential mediator of IL-1β and IL-18 processing and secretion, were highly susceptible to C. difficile infection. ASC−/− mice exhibited enhanced translocation of commensals to multiple organs after C. difficile infection. Notably, ASC−/− mice exhibited impaired CXCL1 production and neutrophil influx into intestinal tissues in response to C. difficile infection. The impairment in neutrophil recruitment resulted in reduced production of IL-1β and CXCL1 but not IL-18. Importantly, translocated commensals were required for ASC/Nlrp3-dependent IL-1β secretion by neutrophils. Mice lacking IL-1β were deficient in inducing CXCL1 secretion, suggesting that IL-1β is the dominant inducer of ASC-mediated CXCL1 production during C. difficile infection. These results indicate that translocated commensals play a crucial role in CXCL1-dependent recruitment of neutrophils to the intestine through an IL-1β/NLRP3/ASC–mediated positive-feedback mechanism that is important for host survival and clearance of translocated commensals during C. difficile infection.
Cutting Edge: A Novel Mechanism Bridging Innate and Adaptive Immunity: IL-12 Induction of CD25 To Form High-Affinity IL-2 Receptors on NK Cells
Authors: Lee Seung-Hwan , Fragoso Maria F. , Biron Christine A.
Published: August 2012

NK cell expression and use of the IL-2Rα–chain (CD25), required for the high-affinity IL-2R, remain poorly understood. The studies reported in this article demonstrate that infections with murine CMV (MCMV), but not with lymphocytic choriomeningitis virus, induce CD25 on NK cells, along with high levels of IL-12 and IL-18. The cytokines act ex vivo to increase CD25 levels, and IL-12, IL-12R, and STAT4, but not the NK activating receptor Ly49H, are required for peak induction in vivo. All examined NK cell populations are driven into proliferation and incorporate BrdU in response to high ex vivo concentrations of IL-2, but only those from MCMV infection respond to low ex vivo concentrations of IL-2. The numbers of NK cells elicited during MCMV infection are reduced by IL-2 neutralization. Thus, a link between innate and adaptive immunity is established by which composition of innate cytokine responses sets up to promote NK cell use of a factor supporting adaptive responses.
Predictive surficial materials and geology derived from LANDSAT 7, Yellowknife, NTS 85J, Northwest
Territories
Authors: Stevens C W , Kerr D E , Wolfe S A , Eagles S
Published: August 2012

Surficial material and geology maps provide important geoscience information required for geological reconstructions, mineral exploration and development and land use planning in northern Canada. In this study, remote predictive mapping was used to derive
predictive surficial material and surficial geology maps for Yellowknife NTS 85J, located within the Slave Geological Province. The predictive maps were generated using radiometrically balanced LANDSAT 7 imagery and knowledge gained from airphoto interpretations, field observations and legacy
datasets. This Open File contains graphical and digital georeferenced versions of the predictive maps. A printable version of the predictive surficial geology map is also provided in pdf format (map scale 1:125 000).
Meeting the Occupational Needs of Mental Health Service Users: Indicative Care Packages and Actual Practice
Authors: Parkinson Sue , Morley Mary , Stewart Louise , Brockbank Helen
Published: August 2012

Payment mechanisms in English mental health services require professionals to describe treatments and demonstrate cost-effectiveness. A national occupational therapy study has prepared the way by profiling the occupational needs of service users and describing indicative care packages.

This practice analysis reports on a local survey, which was conducted in parallel with the national study. Treatment aims were found to correspond with key elements of the occupational profiles. This supports the accuracy of the profiles. It also provides evidence towards the effectiveness of the service being provided by demonstrating the ability of occupational therapists to target the proven needs of service users.
Development of optimum preplanning for maxillofacial surgery using selective laser sintering
Authors: Siva Rama Krishna L , Bal Reddy MP , Venkatesh S
Published: August 2012

Rapid prototyping is a technology that can automatically construct physical models from CAD data. It helps designers to quickly create tangible prototype of their design. This technology has numerous applications; they make excellent visual aids for communicating ideas to the customers. It plays an important role in producing complex and intricate models in both engineering and medical applications. This paper presents its application in medical field. It discusses the development of optimum preplanning for maxillofacial surgery using selective laser sintering process. It involves identifying the optimum value of various parameters like threshold value, gantry tilt angle, resolution, layer thickness and interval thickness of CT scan image. The 3D model of the CT scan image is developed and converted into .stl file. The 3D model is produced on Selective Laser Sintering machine by considering shrinkage and compensation allowances. Two case studies are presented and comparison is made with regard to time taken for surgery using RP model and without using RP model. This helps in reducing time and increase precision, as well as to decrease morbidity for maxillofacial surgery, thus resulting in less suffering to patient , thereby reducing costs and length of hospitalization and improving quality of life.
Sensor fault diagnosis for automotive engines with real data evaluation
Authors: Sangha MS , Yu DL , Gomm JB
Published: August 2012

In this paper, a new fault diagnosis method using an adaptive neural network for automotive engines is developed. A redial basis function (RBF) network is used as a fault classifier with its widths and weights on-line adapted to cope with model uncertainty and time varying dynamics caused by mechanical wear of engine parts, environment change, etc. Five different sensors are investigated for an automotive engine including throttle angle, manifold pressure, manifold temperature, crankshaft speed and engine torque. The engine data is acquired from a one-litre Volkswagen petrol engine test bed under different operating states, and then simulated multiplicative faults are superimposed. The real data experiments confirm that sensor faults as small as 2% can be detected and isolated clearly. The developed scheme is capable of diagnosing faults in on-line mode and can be directly implemented in an on-board engine diagnosis system.
Optimization of surface roughness in CNC end milling using response surface methodology and genetic algorithm
Authors: Sidda Reddy B , Suresh Kumar J , Vijaya Kumar Reddy K
Published: August 2012

Pre-hardened steel (P20) is a widely used material in the production of moulds/dies due to less wear resistance and used for large components. In this study, minimization of surface roughness has been investigated by integrating design of experiment method, Response surface methodology (RSM) and genetic algorithm. To achieve the minimum surface roughness optimal conditions are determined. The experiments were conducted using Taguchi’s L50 orthogonal array in the design of experiments (DOE) by considering the machining parameters such as Nose radius (R), Cutting speed (V), feed (f), axial depth of cut (d) and radial depth of cut(rd). A predictive response surface model for surface roughness is developed using RSM. The response surface (RS) model is interfaced with the genetic algorithm (GA) to find the optimum machining parameter values.
Bons video games e boa aprendizagem
Authors: Gee James Paul
Published: August 2012

O artigo defende que os bons  videogames  incorporam bons princípios de aprendizagem, apoiados pelas  pesquisas  atuais  em Ciência Cognitiva, e os lista:  identidade; interação; produção; riscos; customização; agência; boa ordenação dos problemas; desafio e consolidação; “na hora certa” e “a pedido”;  sentidos contextualizados; frustração prazerosa; pensamento sistemático;  exploração, pensamento lateral, revisão dos  objetivos; ferramentas inteligentes e conhecimento distribuído; equipes transfuncionais e performance anterior à competência.  O artigo conclui com a seguinte pergunta: como podemos tornar  a aprendizagem, dentro e fora das escolas, mais parecida com os games no sentido de que ela use  os tipos de princípios de aprendizagem que os jovens vêem todos os dias nos bons videogames, quando e se estiverem jogando esses games de um modo reflexivo e estratégico?
Conselho de Escola: funções, problemas e perspectivas na gestão escolar democrática
Authors: Souza Ângelo Ricardo de
Published: August 2012

O artigo, de natureza bibliográfi ca, discute os problemas e as perspectivas democráticas dos conselhos de escola. O trabalho discute inicialmente o problema da mitifi cação da técnica na constituição e uso de mecanismos organizativos de gestãoescolar. Na seqüência, o texto demonstra como as funções e potencialidades democráticas do conselho de escola são contrapostas às difi culdades cotidianas para a constituição, manutenção e desenvolvimento de espaços coletivos de gestão,demonstrando o quanto os conselhos são, em princípio, espaços do diálogo e, ao mesmo tempo, o quão distante estão da efetivação da sua função democrática. As conclusões apontam para o importante reconhecimento dos limites existentes na formulação e organização dos conselhos de escola, mas, ao mesmo tempo, sugerem a necessidade da insistência na manutenção e aperfeiçoamento dos conselhos por representarem uma contribuição signifi cativa para a gestão escolar democrática.
Trabalho, práxis social e Educação: notas para uma teoria da atividade educativa
Authors: Macário Epitácio
Published: August 2012

O artigo discute a natureza e a especificidade da atividade educativa no âmbito da práxis social. Expõe, inicialmente, as categorias “objetivação” e “apropriação” como momentos constitutivos do trabalho e da práxis social. Sobre estes fundamentos, mostra a necessidade, a função social, o sujeito e o objeto da atividade educativa. O texto fundamenta-se no pensamento de Lukács e Leontiev.
Local Scarcity of Women Predicts Higher Fertility among Married Couples and More Single Father Households
Authors: Kruger Daniel J , Vanas Sarah B
Published: August 2012

Because the reproductive strategies of men and women are somewhat divergent, influences of the sex ratio on the intensity of mating competition and selectivity for partners produce different outcomes in female biased and male biased populations. Male mating opportunities are enhanced by scarcity and incentives for long-term commitment are diminished, encouraging serial and simultaneous polygyny. Paternal investment is lower in these populations, as indicated by higher divorce rates, more out-of-wedlock births, and a greater proportion of single mother households. Scarce females are able to more effectively secure commitment from partners as well as demand higher levels of resource investment. Women marry earlier in these populations. Although single father households are relatively uncommon, we expect to see higher proportions of households with children headed by single fathers where women are scarce. We also expect to see higher fertility among married couples, both because women may have greater bargaining power in reproductive decision-making and the role of woman in childbearing may be more salient to and valued by men. Data from the 2000 U.S. Census across 318 Metropolitan Statistical Areas supported these hypotheses.
How should sparse in situ measurements be compared to continuous model data?
Authors: de Mora L. , Butenschön M. , Allen J. I.
Published: August 2012

Abstract. This work demonstrates the importance of an adequate method to sub-sample model results when comparing with in situ measurements. A test of model skill was performed by comparing a multi-decadal hindcast against a sparse, unevenly distributed historic in situ dataset. The comparison was performed using a point-to-point method. The point-to-point method masked out all hindcast cells that did not have a corresponding in situ measurement in order to compare each in situ measurement against its most similar cell from the model. The application of the point-to-point method showed that the model was successful at reproducing many inter-annual trends. Furthermore, this success was not immediately apparent using the previous comparison methods, which compared model and measurements aggregated to regional averages. Time series, data density and target diagrams were employed to illustrate the impact of switching from the previous method to the point-to-point method. The comparison based on regional averages gave significantly different and sometimes contradicting results that could lead to erroneous conclusions on the model performance. We therefore recommend that researchers take into account for the limitations of the in situ datasets, process the model to resemble the data as much as possible, and we advocate greater transparency in the publication of methodology.
General Assumption of Psychological Behavior Based on Finger Print Pattern
Authors: Kumar Agarwal Kishore , Kumar Dutt Hemant , Saxena Alok , Dimri Deepak , Singh Daulat , Bhatt Naveen
Published: August 2012

The impressions from the pulp of finger are known as fingerprints. Using fingerprints to identify indi­viduals has become an invaluable tool worldwide. A Study of finger print pattern was performed in the prisoners and normal population (non prisoners) of hilly region to compare whorls, loops, arches and composites in each hand using ink technique. The goal of the study was to identify the behavioral traits (somatic, psychological and Neurological) of these two groups on the basis of finger print pattern. Prevalence of whorls and arches were more in right hand of control group as compare to prisoners. On contrary, loops were found more in right hand of prisoners than control group. Left hand of control and prisoners showed following results: whorls and arches in control group > prisoners and loops in prisoners > control group. Aforementioned Results were found statistically significant.
Incidence of Pod Integrity on the Fungal Microflora and Ochratoxin-A Production in Cocoa
Authors: Mounjouenpou Pauline , Gueule Dominique , Tetmoun Suzanne Abeline Maboune , Guyot Bernard , Fontana-Tachon Angélique , Guiraud Joseph Pierre
Published: August 2012

Ochratoxin-A (OTA) is a mycotoxin that has nephrotoxic, tetragenic, immunotoxic and carcinogenic effects in the human organism. It contaminates several foodstuffs, notably cocoa. The purpose of our study was to compare the incidence of cocoa pod integrity on the fungal microflora and ochratoxin- A production in Cameroon. Irrespective of pod condition, fermented cocoa beans were contaminated by OTA. The maximum mould content was obtained in beans from damaged pod. However, the fungal microflora was more diversified for beans from pod damaged during harvesting than for beans from intact pods, throughout the post-harvest process. The toxigenic strains isolated belonged to the genera Aspergillus. Aspergillus carbonarius isolated from damaged pods, displayed the greatest OTA production which was 110.7 ng.g-1 on cocoa medium and 2772,0 ng.g-1  on official medium. There was a good correlation between OTA presence in the beans and isolated toxigenic strains.
Swift Foxes and Ideal Free Distribution: Relative Influence of Vegetation and Rodent Prey Base on Swift Fox Survival, Density, and Home Range Size
Authors: Thompson Craig M. , Gese Eric M.
Published: August 2012

Swift foxes (Vulpes velox) are an endemic mesocarnivore of North America subject to resource and predation-based pressures. While swift fox demographics have been documented, there is little information on the importance of top-down versus bottom-up pressures or the effect of landscape heterogeneity. Using a consumable resource-based ideal free distribution model as a conceptual framework, we isolated the effects of resource-based habitat selection on fox population ecology. We hypothesized if swift fox ecology is predominantly resource dependant, distribution, survival, and space use would match predictions made under ideal free distribution theory. We monitored survival and home range use of 47 swift foxes in southeastern Colorado from 2001 to 2004. Annual home range size was 15.4 km2, and seasonal home range size was 10.1 km2. At the individual level, annual home range size was unrelated to survival. Estimates of fox density ranged from 0.03 to 0.18 foxes/km2. Seasonal survival rates were 0.73 and 1.0 and did not differ seasonally. Foxes conformed to the predictions of the ideal free distribution model during winter, indicating foxes are food stressed and their behavior governed by resource acquisition. During the rest of the year, behavior was not resource driven and was governed by security from intraguild predation.
“On-Water” Catalyst-Free Ecofriendly Synthesis of the Hantzsch Dihydropyridines
Authors: Pramanik Amit , Saha Manabendra , Bhar Sanjay
Published: August 2012

An eco-friendly “on-water” protocol for efficient catalyst-free synthesis of the Hantzsch dihydropyridines from aryl, heteroaryl, alkyl, and vinylogous aldehydes has been developed with minimum auxiliary substances, toxic reagents, organic solvents, and disposal problems.
Designing Paclitaxel Drug Delivery Systems Aimed at Improved Patient Outcomes: Current Status and Challenges
Authors: Surapaneni Madhu S. , Das Sudip K. , Das Nandita G.
Published: August 2012

Paclitaxel is one of the most widely used and effective antineoplastic agents derived from natural sources. It has a wide spectrum of antitumor activity, particularly against ovarian cancer, breast cancer, nonsmall cell lung cancer, head and neck tumors, Kaposi's sarcoma, and urologic malignancies. It is a highly lipophilic compound with a log P value of 3.96 and very poor aqueous solubility of less than 0.01 mg/mL. In addition, the compound lacks functional groups that are ionizable which could potentially lead to an increase in its solubility with the alteration in pH. Therefore, the delivery of paclitaxel is associated with substantial challenges. Until the introduction of Abraxane, only commercial formulation was solution of paclitaxel in cremophor, which caused severe side effects. However, in recent years, a number of approaches have been reported to solubilize paclitaxel using cosolvents and inclusion complexes. In addition, innovative approaches have been reported for passive targeting of tumors using nanoparticles, nanosuspensions, liposomes, emulsions, micelles, implants, pastes and gels. All approaches for delivery of improved therapeutic outcome have been discussed in this paper.
Using Analogies to Communicate Information about Health Risks
Authors: Galesic Mirta , Garcia‐Retamero Rocio
Published: August 2012

Analogies are often used to explain health‐related concepts in medical practice, but it is unclear whether they actually improve understanding and, if so, why. Here, we studied these issues in experiments on probabilistic national samples in two countries, focusing on two questions. First, we investigated whether analogies are helpful in communicating medical information to people with different levels of numeracy and for tasks of different levels of difficulty. Second, following existing theories of analogies, we studied what characteristics of analogies improve their helpfulness. Our results revealed that for difficult medical problems, analogies were helpful to high‐numeracy people but less so to low‐numeracy people. For easy medical problems, the results were reversed. Different analogies were successful in different cultural contexts. In accord with theoretical expectations, the most helpful analogies were those with high similarity of the relationships between objects in their target and base and those with highly familiar bases. Copyright © 2012 John Wiley & Sons, Ltd.
TEACHING INDIVIDUALS TO SIGNAL FOR ASSISTANCE IN A TIMELY MANNER
Authors: Saunders Muriel D. , Saunders Richard R.
Published: August 2012

The study describes the adaptive‐switch performances of eight adults with severe multiple impairments. Each was given a series of progressively more difficult discrimination tasks that, if solved, would require the participant to close the switch to activate a device that was not operating or to stay away from the switch if the device was operating. Then in a 2‐choice format, a preference test was conducted by providing two devices simultaneously that could be activated or deactivated by closure or release of the switch. Finally, a preferred device was activated and then surreptitiously deactivated. Switch closures in this contingency activated a speech‐generating device that played the message, ‘Help me’. All eight participants learned to control the devices by using their adaptive switch, but only four participants learned to make a request for help. Reasons for the different performances across learners and nonlearners are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
The Effects of Socio‐Economic Status on Infant Attention
Authors: Clearfield Melissa W. , Jedd Kelly E.
Published: August 2012

The development of visual attention is a key component of cognitive functioning in infancy and childhood. By the time children in poverty reach school, deficits in attention are readily apparent; however, when these attention delays manifest is unknown. The current study tested attention longitudinally at 6, 9 and 12 months in infants from high‐socio‐economic status (SES) and low‐SES families. Infants were tested in a free play attention task in both simple and complex conditions, and two measures each of attention and inattention were scored. High‐SES infants showed greater attention overall and greater increases in attention when the stimuli were more complex. Low‐SES infants showed higher inattention than their high‐SES peers at all ages and were less likely to modulate their attention on the basis of stimulus complexity. Thus, by 6 months of age, low‐income infants already show deficits in attention. Results are discussed in terms of adaptability, implications for social development and attention interventions. Copyright © 2012 John Wiley & Sons, Ltd.
Cardiac tissue development for delivery of embryonic stem cell‐derived endothelial and cardiac cells in natural matrices
Authors: Turner William S. , Wang Xiaoling , Johnson Scott , Medberry Christopher , Mendez Jose , Badylak Stephen F. , McCord Marian G. , McCloskey Kara E.
Published: August 2012

The packaging and delivery of cells for cardiac regeneration has been explored using a variety biomaterials and delivery methods, but these studies often ignore one or more important design factors critical for rebuilding cardiac tissue. These include the biomaterial architecture, strength and stiffness, cell alignment, and/or incorporation of multiple cell types. In this article, we explore the combinatorial use of decellularized tissues, moldable hydrogels, patterned cell‐seeding, and cell‐sheet engineering and find that a combination of these methods is optimal in the recreation of transplantable cardiac‐like tissue in vivo. We show that decellularized urinary bladder matrix (UBM), that is compliant and suturable, supports the survival of cell cultures but does not allow maintenance of cell‐to‐cell contacts of transferred cell‐sheets (presumably, due to its rough surface). Moreover, the UBM material must be filled with hyaluronan (HA) hydrogels for smoothing rough surfaces and allowing the delivery of greater cell numbers. We additionally incorporated our previously developed “wrinkled” microchip for inducing alignment of cardiac cells with a laser‐etched mask for co‐seeding patterned “channels” of cells. This article also introduces a novel method of plasma coating for cell‐sheet engineering that compares well with electron bean irradiation methods and may be combined with our “wrinkled” surfaces to facilitate the alignment of cardiac cells into sheets. Our data shows that an optimal design for generating cardiac tissue would include (1) decellularized matrix seeded with endothelial cells in a HA layered with (2) prealigned cardiac cell‐sheets fabricated using our “wrinkled” microchips and thermo‐responsive polymer [poly(N‐isopropylacrylamide)] cell sheet transfer system. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Ti–Ge binary alloy system developed as potential dental materials
Authors: Lin Wen‐Jiao , Wang Ben‐Li , Qiu Ke‐Jin , Zhou Fei‐Yu , Li Li , Lin Jun‐Pin , Wang Yan‐Bo , Zheng Yu‐Feng
Published: August 2012

As‐cast Ti–xGe (x = 2, 5, 10, 20 wt %) binary alloys were produced in this work, and various experiments were carried out to investigate the microstructure, mechanical properties, in vitro electrochemical and immersion corrosion behaviors as well as cytotoxicity with as‐cast pure Ti as control, aiming to study the feasibility of Ti–xGe alloy system as potential dental materials. The microstructure of Ti–xGe alloys changes from single α‐Ti phase to α‐Ti + Ti5Ge3 precipitation phase with the increase of Ge content. Mechanical tests show that Ti–5Ge alloy has the best comprehensive mechanical properties. The corrosion behavior of Ti–xGe alloys in artificial saliva with different NaF and lactic acid addition at 37°C indicates that Ti–2Ge and Ti–5Ge alloys show better corrosion resistance to fluorine‐containing solution. The cytotoxicity test indicates that Ti–xGe alloy extracts show no obvious reduction of cell viability to L‐929 fibroblasts and MG‐63 osteosarcoma cells, similar to pure Ti which is generally acknowledged to be biocompatible. Considering all these results, Ti–2Ge and Ti–5Ge alloys possess the optimal comprehensive performance and might be used as potential dental materials. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Tape‐cast and sintered β‐tricalcium phosphate laminates for biomedical applications: Effect of milled Al2O3 fiber additives on microstructural and mechanical properties
Authors: Tanimoto Yasuhiro , Teshima Masahiro , Nishiyama Norihiro , Yamaguchi Masaru , Hirayama Satoshi , Shibata Yo , Miyazaki Takashi
Published: August 2012

The aim of this study was to develop the tape‐cast, laminated, and sintered β‐tricalcium phosphate (β‐TCP) with milled Al2O3 fibers for biomedical applications. Moreover, the effects of Al2O3‐fiber content on the microstructural and mechanical properties of the sintered β‐TCP laminates were investigated. The milled Al2O3 fibers were added at four different contents, namely 0, 5, 10, or 15 mass%, to the initial β‐TCP slurry. Next, β‐TCP green sheets were fabricated from the β‐TCP slurry containing the milled Al2O3 fibers by a tape‐casting method. Finally, six plies of β‐TCP monolayer sheet were laminated and sintered at a maximum temperature of 1100°C in a furnace. The results showed that there were large differences between the apparent porosities, dynamic hardness, and flexural properties of the sintered β‐TCP laminates with Al2O3‐fiber contents of 0 and 5 mass%, but few differences among laminates with fiber contents of 5, 10, and 15 mass%. This indicates that the addition of only 5 mass% of Al2O3 fibers strongly affects the degree of sintering, corresponding to crystallization of the β‐TCP matrix phase. Furthermore, the flexural moduli of our materials ranged from 10.7 to 16.0 GPa when the Al2O3‐fiber content changed from 5 to 15 mass% and were the almost same as those of human bones reported by other researchers. In conclusion, sintered β‐TCP laminates with Al2O3 fibers have potential uses in a wide range of biomedical applications because the microstructural and mechanical properties of the sintered β‐TCP laminates can be controlled by adding Al2O3 fibers to the β‐TCP. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Molecular orientation analysis of organic thin films by z‐polarization Raman microscope
Authors: Mino Toshihiro , Saito Yuika , Yoshida Hiroyuki , Kawata Satoshi , Verma Prabhat
Published: August 2012

Polarization‐dependent Raman microscopy is a powerful technique to perform both structural and chemical analyses with submicron spatial resolution. In conventional Raman microscopy, the polarization measurements are limited only in the direction parallel to the sample plane. In this work, we overcome the limit of conventional measurements by controlling the incident polarization by a spatially modulated waveplate. In this method, the polarization perpendicular to the sample surface (z‐polarization) can be detected together with the parallel polarization (xy‐polarization). Because of this unique polarization control, our Raman microscope has the ability to image the molecular orientation, together with the molecular analysis. Here, we have investigated thin films of pentacene molecules that are widely studied as an organic semiconductor material. The orientations of pentacene molecules are imaged with a spatial resolution of 300 nm. Our results clearly indicate that the lamellar grains show the lower tilt angles compared to the neighboring islands, which has not been proved in conventional methods. The substrate effects and the thickness dependence of the film are also studied. These results provide knowledge about the relationship between the devise performance and the film structures, which is indispensable for future device exploitations. Copyright © 2012 John Wiley & Sons, Ltd.
High‐resolution stimulated Raman spectroscopy and analysis of the ν1 band of osmium tetroxide
Authors: Louviot M. , Boudon V. , Bermejo D. , Martínez R. Z. , Manceron L.
Published: August 2012

We present the first high‐resolution stimulated Raman study of osmium tetroxide (OsO4). Lines from the ν1 totally symmetric stretching fundamental have been assigned. These data together with the infrared assignments of the ν3 band previously recorded (M. Louviot et al., J. Quant. Spectrosc. Radiat. Transfer, 2012, 113, 119–127) allowed a refinement of the analysis of the ν1/ν3 stretching dyad. We found that the ν1 band has an unusual positive isotopic shift of approximately 0.32 cm− 1/amu, which gives further evidence that the stretching dyad should be perturbed by a complex nearby bending band polyad. This work is part of a global effort to analyze all fundamental bands of OsO4 to obtain a more precise experimental value of the ground state bond length for this heavy metal‐containing molecule. The result could serve as a benchmark for high‐level quantum chemistry calculations. Copyright © 2012 John Wiley & Sons, Ltd.
Stability for the finite difference schemes of the linear wave equation with nonuniform time meshes
Authors: Cho Chien‐Hong
Published: August 2012

We consider in this article the 1‐dim linear wave equation vtt = vxx(0 < x < 1,t > 0) and its finite difference analogue with nonuniform time meshes. We are going to discuss the stability for such schemes. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Characteristics of paper mill sludge‐wood fiber‐high‐density polyethylene composites
Authors: Huang H.B. , Du H.H. , Wang W.H. , Shi J.Y.
Published: August 2012

Paper mill sludge (PMS) is a waste material from pulping. In this article it was used to replace part of a wood fiber (WF) filler to reinforce high‐density polyethylene (HDPE). The properties of the PMS/WF/HDPE composites were investigated. When half of WF was replaced with PMS, the bending strength and modulus of WF/HDPE composites decreased by 16.08% and 29.91%, respectively, but their impact strength increased by 11.31%. Dynamic mechanical analysis demonstrated that with PMS addition, the storage modulus decreased and the loss tangent increased. Although the flexural properties of the PMS/WF/HDPE composites decreased compared to WF/HDPE composite, they still had satisfactorily high strengths. The 30:30:36 PMS/WF/HDPE composite presented bending and impact strengths of 61.00 MPa and 12.11 kJ m−2, respectively. The 50:20:26 PMS/WF/HDPE composite presented bending and impact strengths of 55.02 MPa and 10.37 kJ m−2, respectively. Rheological test proved that substituting part of WF with PMS would not affectmanufacture processing. This study indicated that paper mill sludge could be used in wood plastic composites, which would reduce pollution from paper manufacturing. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Capillary effects in vacuum‐assisted resin transfer molding with natural fibers
Authors: Francucci Gastón , Vázquez Analía , Ruiz Edu , Rodríguez Exequiel S.
Published: August 2012

The study of the capillary flow developed during the processing of composite materials is key because it acts as an important driving force for the impregnation of the fiber tows. It is also the main mechanism of void formation during infiltration of the fibers. In this work, capillary pressure of jute/vinylester composites was measured and the impact of capillary forces on fabric permeability was analyzed. It was found that the capillary pressure was significantly higher in vegetal than in synthetic fiber fabrics. In addition, the permeability of the fibers was characterized using various fluids. The resulting permeability was influenced by the nature of fluid and its polar property. Finally, the capillary pressure measured by this work was used to correct the experimental permeability in order to obtain a property independent of the test fluid. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Composites based on EVA and barium titanate submicrometric particles: Preparation by high‐energy ball milling and characterization
Authors: Serra‐Gómez R. , González‐Gaitano G. , González‐Benito J.
Published: August 2012

Ethylene vinyl acetate copolymer, a thermoplastic semicrystalline polymer, has been blended with barium titanate submicrometric particles (BaTiO3) by means of high‐energy ball milling (HEBM) for obtaining composites in the form of films by hot pressing. Two different milling conditions have been considered: (i) milling at room temperature and (ii) milling under the temperature of the liquid nitrogen (cryomilling). The resulting composites have been fully characterized by spectroscopic and microscopic techniques to study the structure and morphology as a function of the processing conditions. A very good dispersion of the particles is attained under cryogenic conditions and, irrespective of the milling method, structural modifications were not observed in any of the materials used. Cross‐contamination of iron from the milling tools is also reduced to acceptable values for HEBM standards, especially in the case of cryomilling, an important issue for the use of these composites in electrical applications. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Anionic nylon 6/TiO2 composite materials: Effects of TiO2 filler on the thermal and mechanical behavior of the composites
Authors: Rusu Gheorghe , Rusu Elena
Published: August 2012

The nylon 6‐based composite materials containing untreated and surface‐treated TiO2 particles with 3‐aminopropyltriethoxysilane (APTEOS), as coupling agent were prepared by in situ anionic polymerization of ε‐caprolactam in the presence TiO2 as a filler using the rotational molding technique. The thermal behavior and mechanical properties of the neat nylon 6 and its composites were investigated using various techniques such as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), a tensile and flexural test and impact strength. Experimental results revealed that both untreated and surface‐modified TiO2 had distinct influence on the melting temperature (Tm), crystallization temperature (Tc), and degree of crystallinity (αDSC), thermal stability, storage modulus (E′), and loss factor (tan δ), and mechanical properties of nylon 6 matrix. Dynamical mechanical analysis indicated that addition of TiO2 particles into nylon 6 matrix increased both the storage modulus and the glass transition temperature. The corresponding values of nylon 6 composites with modified filler were higher than that of nylon 6 composite with untreated TiO2 particles. Tensile and flexural characteristics of the nylon 6 composites were found to increase while the elongation at break and impact strength with increase in TiO2 concentration relative to neat nylon 6. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Effect of compressive loading speed and stacking sequence on mechanical characteristics of satin weave E‐glass/epoxy composites
Authors: Wang Na , Cho Chongdu
Published: August 2012

This article experimentally investigated the in‐plane loading speed dependent mechanical properties and failure modes of satin weave E‐glass/epoxy composite laminates [45/−45/0/90]ns. Two types of E‐glass fabric/epoxy pre‐impregnated tapes were used to manufacture the composite laminates specimens. The low strain rate tests were conducted with an INSTRON™ testing machine, and the high strain rate tests done using a pulse shape modified compressive Split Hopkinson Pressure Bar apparatus. From the experimental result, it was concluded that under different strain rate loading, compressive strength, modulus, and strain at peak stress were rate sensitive. Optical and microscopic photos of the specimens were taken to determine operative failure modes. Within the studied strain rate regimes, the failure mode changed from splitting followed by fiber kink buckling to predominantly delamination and shear fracture as strain rate increases from quasi‐static to high strain rates. Compressive properties and failure modes were severely affected by strain rate, stacking sequence, and fabric material. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
Cholinergic Involvement and Synaptic Dynamin 1 Expression in Yokukansan‐mediated Improvement of Spatial Memory in a Rat Model of Early Alzheimer's Disease
Authors: Uchida Naoki , Takasaki Kotaro , Sakata Yuri , Nogami Ai , Oishi Hiroshi , Watanabe Takuya , Shindo Taro , Egashira Nobuaki , Kubota Kaori , Katsurabayashi Shutaro , Mishima Kenichi , Fujiwara Michihiro , Nishimura Ryoji , Iwasaki Katsunori
Published: August 2012

The aim of this study was to investigate the effect of Yokukansan (YKS) on the impairment of spatial memory and cholinergic involvement in a rat model of early‐phase Alzheimer's disease (AD). In this model, rats underwent four‐vessel transient cerebral ischemia and then were treated with beta amyloid oligomers injected intracerebroventricularly once daily for 7 days. These animals showed memory impairment in an eight‐arm radial maze task without histological evidence of apoptosis but with a decrease in expression of hippocampal dynamin 1, an important factor in synaptic vesicle endocytosis. Oral administration of YKS for 2 weeks significantly increased the number of correct choices and decreased the number of error choices in the eight‐arm radial maze task (P < 0.05). Moreover, YKS significantly increased high K+‐evoked potentiation of acetylcholine (ACh) release (P < 0.05) and significantly increased the expression of dynamin 1 (P < 0.01) in the hippocampus. The ameliorative effect of YKS on spatial memory impairment in our rat model of early‐phase AD may be mediated in part by an increase in ACh release and modulation of dynamin 1 expression, leading to improved synaptic function. Future studies will determine whether YKS is similarly useful in the treatment of memory defects in patients diagnosed with early‐stage AD. Copyright © 2012 John Wiley & Sons, Ltd.
Sorbitol counteracts temperature- and chemical-induced denaturation of a recombinant α-amylase from alkaliphilicBacillussp. TS-23
Authors: Chi Meng-Chun , Wu Tai-Jung , Chen Hsing-Ling , Lo Huei-Fen , Lin Long-Liu
Published: August 2012

Enzymes are highly complex systems with a substantial degree of structural variability in their folded state. In the presence of cosolvents, fluctuations among vast numbers of folded and unfolded conformations occur via many different pathways; alternatively, certain conformations can be stabilized or destabilized. To understand the contribution of osmolytes to the stabilization of structural changes and enzymatic activity of a truncated Bacillus sp. TS-23 α-amylase (BACΔNC), we monitored amylolytic activity, circular dichroism, and fluorescence as a function of osmolytes. In the presence of trimethylamine N-oxide (TMAO) and sorbitol, BACΔNC activity was retained significantly at elevated temperatures. As compared to the control, the secondary structures of this enzyme were essentially conserved upon the addition of these two kinds of osmolytes. Fluorescence results revealed that the temperature-induced conformational change of BACΔNC was prevented by TMAO and sorbitol. However, glycerol did not provide profound protection against thermal denaturation of the enzyme. Sorbitol was further found to counteract guanidine hydrochloride- and SDS-induced denaturation of BACΔNC. Thus, some well-known naturally occurring osmolytes make a dominant contribution to the stabilization of BACΔNC.