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Bovine pericardium (BP) is a vascular biomaterial used in cardiovascular surgery that is typically cross-linked for masking antigenicity and enhance stability. There is a need for biochemical evaluation of the tissue properties prior to implantation to ensure that quality and reliability standards are met. Here, engineered antigen removed BP (ARBP) that was cross-linked with 0.2% and 0.6% glutaraldehyde (GA), and further calcified in vitro to simulate graft calcifications upon implantation was characterized nondestructively using fluorescence lifetime imaging (FLIm) to identify regions of interest which were then assessed by Raman spectroscopy. We observed that the tissue fluorescence lifetime shortened, and that Raman bands at 856, 935, 1282, and 1682 cm-1 decreased, and at 1032 and 1627 cm-1 increased with increasing GA cross-linking. Independent classification analysis based on fluorescence lifetime and on Raman spectra discriminated between GA-ARBP and untreated ARBP with an accuracy of 91% and 66%, respectively. Pearson's correlation analysis showed a strong correlation between pyridinium cross-links measured with high-performance liquid chromatography and fluorescence lifetime measured at 380-400 nm (R = -0.76, p = 0.00094), as well as Raman bands at 856 cm-1 for hydroxy-proline (R = -0.68, p = 0.0056) and at 1032 cm-1 for hydroxy-pyridinium (R = 0.74, p = 0.0016). Calcified areas of GA cross-linked tissue showed characteristic hydroxyapatite (959 and 1038 cm-1) bands in the Raman spectrum and fluorescence lifetime shortened by 0.4 ns compared to uncalcified regions. FLIm-guided Raman imaging could rapidly identify degrees of cross-linking and detected calcified regions with high chemical specificity, an ability that can be used to monitor tissue engineering processes for applications in regenerative medicine.

The United Nations Sustainable Development Goals (SDGs) are a significant marker in global efforts to universalise a conception of ecologically sustainable human development. SDG 4's expanded vision of quality education for all extends to the Education for Sustainable Development (ESD) Agenda's call for education that contributes to all of SDGs, and prepares students to 'transform our world'. From a critical perspective, this paper considers the incompatibility of endless (compound) economic growth and capital accumulation, under capitalism, with the required CO2 reductions that the climate emergency demands. The paper shows how the ESD proposals reflect the orthodoxy of education as human capital formation for economic development, albeit within a reformed 'green growth' model. At the same time, it argues that their distinctive ambitions and transformational language provide space for critical educators to simultaneously work with and against their contradictions and limitations, and to advance non-capitalist and degrowth alternatives.

The extracellular matrix architecture of bovine pericardium (BP) has distinct biochemical and biomechanical properties that make it a useful biomaterial in the field of regenerative medicine. Collagen represents the dominant structural protein of BP and is therefore intimately associated with the properties of this biomaterial. Enzymatic degradation of collagen molecules is critical for extracellular matrix turnover, remodeling and ultimately tissue regeneration. We present a quantitative, label-free and non-destructive method for monitoring changes in biochemical and biomechanical properties of BP during tissue degradation, based on multi-spectral fluorescence lifetime imaging (ms-FLIm). Strong correlations of fluorescence intensity ratio and average fluorescence lifetime were identified with collagen content, Young's Modulus and Ultimate tensile strength during collagenase degradation, indicating the potential of optically monitoring collagen degradation using ms-FLIm. The obtained results demonstrate the value of ms-FLIm to assess the quality of biomaterials in situ for applications in regenerative medicine.

New techniques able to monitor the maturation of tissue engineered constructs over time are needed for a more efficient control of developmental parameters. Here, a label-free fluorescence lifetime imaging (FLIm) approach implemented through a single fiber-optic interface is reported for nondestructive in situ assessment of vascular biomaterials. Recellularization processes of antigen removed bovine pericardium scaffolds with endothelial cells and mesenchymal stem cells were evaluated on the serous and the fibrous sides of the scaffolds, 2 distinct extracellular matrix niches, over the course of a 7 day culture period. Results indicated that fluorescence lifetime successfully report cell presence resolved from extracellular matrix fluorescence. The recellularization process was more rapid on the serous side than on the fibrous side for both cell types, and endothelial cells expanded faster than mesenchymal stem cells on antigen-removed bovine pericardium. Fiber-based FLIm has the potential to become a nondestructive tool for the assessment of tissue maturation by allowing in situ imaging of intraluminal vascular biomaterials.

Heart failure (HF) following myocardial infarction (MI) is associated with high incidence of cardiac arrhythmias. Development of therapeutic strategy requires detailed understanding of electrophysiological remodeling. However, changes of ionic currents in ischemic HF remain incompletely understood, especially in translational large-animal models. Here, we systematically measure the major ionic currents in ventricular myocytes from the infarct border and remote zones in a porcine model of post-MI HF. We recorded eight ionic currents during the cell's action potential (AP) under physiologically relevant conditions using selfAP-clamp sequential dissection. Compared with healthy controls, HF-remote zone myocytes exhibited increased late Na+ current, Ca2+-activated K+ current, Ca2+-activated Cl- current, decreased rapid delayed rectifier K+ current, and altered Na+/Ca2+ exchange current profile. In HF-border zone myocytes, the above changes also occurred but with additional decrease of L-type Ca2+ current, decrease of inward rectifier K+ current, and Ca2+ release-dependent delayed after-depolarizations. Our data reveal that the changes in any individual current are relatively small, but the integrated impacts shift the balance between the inward and outward currents to shorten AP in the border zone but prolong AP in the remote zone. This differential remodeling in post-MI HF increases the inhomogeneity of AP repolarization, which may enhance the arrhythmogenic substrate. Our comprehensive findings provide a mechanistic framework for understanding why single-channel blockers may fail to suppress arrhythmias, and highlight the need to consider the rich tableau and integration of many ionic currents in designing therapeutic strategies for treating arrhythmias in HF.

Extracellular matrix (ECM) has emerged as a dynamic tissue component, providing not only structural support, but also functionally participating in a wide range of signaling events during development, injury, and disease remodeling. Investigation of dynamic changes in cardiac ECM proteome is challenging due to the relative insolubility of ECM proteins, which results from their macromolecular nature, extensive post-translational modification (PTM), and tendency to form protein complexes. Finally, the relative abundance of cellular and mitochondrial proteins in cardiac tissue further complicates cardiac ECM proteomic approaches. Recent developments of various techniques to enrich and analyze ECM proteins are playing a major role in overcoming these challenges. Application of cardiac ECM proteomics in disease tissues can further provide spatial and temporal information relevant to disease diagnosis, prognosis, treatment, and engineering of therapeutic candidates for cardiac repair and regeneration.

Advances in digital technologies are dramatically altering the texts and tools available to teachers and students. These technological advances have created excitement among many for their potential to be used as instructional tools for literacy education. Yet with the promise of these advances come issues that can exacerbate the literacy challenges identified in the other articles in this issue. In this article Gina Biancarosa and Gina Griffiths characterize how literacy demands have changed in the digital age and how challenges identified in other articles in the issue intersect with these new demands. Rather than seeing technology as something to be fit into an already crowded education agenda, Biancarosa and Griffiths argue that technology can be conceptualized as affording tools that teachers can deploy in their quest to create young readers who possess the higher levels of literacy skills and background knowledge demanded by today's information-based society. Biancarosa and Griffiths draw on research to highlight some of the ways technology has been used to build the skills and knowledge needed both by children who are learning to read and by those who have progressed to reading to learn. In their review of the research, Biancarosa and Griffiths focus on the hardware and software used to display and interface with digital text, or what they term e-reading technology. Drawing on studies of e-reading technology and computer technology more broadly, they also reflect on the very real, practical challenges to optimal use of e-reading technology. The authors conclude by presenting four recommendations to help schools and school systems meet some of the challenges that come with investing in e-reading technology: use only technologies that support Universal Design for Learning; choose evidence-based tools; provide technology users with systemic supports; and capitalize on the data capacities and volume of information that technology provides. (Contains 1 figure and 77 endnotes.)

The prevalence and prognostic importance of atrial fibrillation (AF) on survival in nonsmall breed dogs with myxomatous mitral valvular disease (MMVD) and congestive heart failure (CHF) remain unknown.To identify the prevalence of AF in nonsmall breed dogs with CHF because of MMVD and to characterize the impact of AF on survival outcome.Sixty-four client-owned dogs (>15 kg) with MMVD and CHF.Retrospective review of medical records for dogs weighing >15 kg with MMVD treated for CHF.Thirty-three dogs presented with AF or developed AF during follow-up examinations, and 31 dogs were free of AF until cardiac-related death. For dogs with AF, median survival time (MST) was 142 days (range: 9-478) while dogs without AF lived 234 days (range: 13-879 days). AF increased risk of cardiac-related death (HR = 2.544; 95% CI = 1.41-4.59; P = .0019) when compared to dogs without AF. MST was significantly prolonged for dogs with AF whose rates were adequately controlled (

BackgroundAlthough the incidence of acute death related to coronary artery disease has decreased with the advent of new interventional therapies, myocardial infarction remains one of the leading causes of death in the US. Current animal models developed to replicate this phenomenon have been associated with unacceptably high morbidity and mortality. A new model utilizing the first diagonal branch of the left anterior descending artery (D1-LAD) was developed to provide a clinically relevant lesion, while attempting to minimize the incidence of adverse complications associated with infarct creation.MethodsEight Yucatan miniature pigs underwent percutaneous embolization of the D1-LAD via injection of 90 µm polystyrene micro-spheres. Cardiac structure and function were monitored at baseline, immediately post-operatively, and at 8-weeks post-infarct using transthoracic echocardiography. Post-mortem histopathology and biochemical analyses were performed to evaluate for changes in myocardial structure and extracellular matrix (ECM) composition respectively. Echocardiographic data were evaluated using a repeated measures analysis of variance followed by Tukey's HSD post hoc test. Biochemical analyses of infarcted to non-infarcted myocardium were compared using analysis of variance.ResultsAll eight pigs successfully underwent echocardiography prior to catheterization. Overall procedural survival rate was 83% (5/6) with one pig excluded due to failure of infarction and another due to deviation from protocol. Ejection fraction significantly decreased from 69.7 ± 7.8% prior to infarction to 50.6 ± 14.7% immediately post-infarction, and progressed to 48.7 ± 8.9% after 8-weeks (p = 0.011). Left ventricular diameter in systole significantly increased from 22.6 ± 3.8 mm pre-operatively to 30.9 ± 5.0 mm at 8 weeks (p = 0.016). Histopathology showed the presence of disorganized fibrosis on hematoxylin and eosin and Picro Sirius red stains. Collagen I and sulfated glycosaminoglycan content were significantly greater in the infarcted region than in normal myocardium (p = 0.007 and p = 0.018, respectively); however, pyridinoline crosslink content per collagen I content in the infarcted region was significantly less than normal myocardium (p = 0.048).ConclusionSystolic dysfunction and changes in ECM composition induced via embolization of the D1-LAD closely mimic those found in individuals with chronic myocardial infarction (MI), and represents a location visible without the need for anesthesia. As a result, this method represents a useful model for studying chronic MI.

Knowledge and resources derived from veterinary medicine represent an underused resource that could serve as a bridge between data obtained from diseases models in laboratory animals and human clinical trials. Naturally occurring disease in companion animals that display the defining attributes of similar, if not identical, diseases in humans hold promise for providing predictive proof of concept in the evaluation of new therapeutics and devices. Here we outline comparative aspects of naturally occurring diseases in companion animals and discuss their current uses in translational medicine, benefits, and shortcomings. Last, we envision how these natural models of disease might ultimately decrease the failure rate in human clinical trials and accelerate the delivery of effective treatments to the human clinical market.

This paper begins by connecting cosmopolitanism to notions of universal and particular knowledge in contemporary conditions. Drawing on the work of Immanuel Wallerstein, we then outline a world-systems approach to knowledge. This approach focuses on the capacity of epistemological structures to either reinforce existing inequalities or produce more egalitarian ways of being. This work centres on links between constructions of universal knowledge and the ways in which their articulation has historically underpinned the inequalities of our current world-system. Through a brief review of work in comparative education elaborating a world culture of education, we argue that like cosmopolitanism, this approach inadequately engages with the historical and political angle of a world-systems approach. We conclude by arguing for world-systems comparative research that maintains a focus on the role of knowledge in the world-system, and how such knowledge may contribute to a more just, equal and democratic world-system.

Quantitative and qualitative evaluations of structure and composition are important in monitoring development of engineered vascular tissue both in vitro and in vivo. Destructive techniques are an obstacle for performing time-lapse analyses from a single sample or animal. This study demonstrates the ability of time-resolved fluorescence spectroscopy (TRFS) and ultrasound backscatter microscopy (UBM), as nondestructive and synergistic techniques, for compositional and morphological analyses of tissue grafts, respectively. UBM images and integrated backscatter coefficients demonstrate the ability to visualize and quantify postimplantation changes in vascular graft biomaterials such as loss of the external elastic lamina and intimal/medial thickening over the grafted region as well as graft integration with the surrounding tissue. TRFS results show significant changes in spectra, average lifetime, and fluorescence decay parameters owing to changes in collagen, elastin, and cellular content between normal and grafted tissue regions. These results lay the foundation for the application of a catheter-based technique for in vivo evaluation of vascular grafts using TRFS and UBM.

Xenogeneic tissues are derived from other animal species and provide a source of material for engineering mechanically functional tissue grafts, such as heart valves, tendons, ligaments, and cartilage. Xenogeneic tissues, however, contain molecules, known as antigens, which invoke an immune reaction following implantation into a patient. Therefore, it is necessary to remove the antigens from a xenogeneic tissue to prevent immune rejection of the graft. Antigen removal can be accomplished by treating a tissue with solutions and/or physical processes that disrupt cells and solubilize, degrade, or mask antigens. However, processes used for cell and antigen removal from tissues often have deleterious effects on the extracellular matrix (ECM) of the tissue, rendering the tissue unsuitable for implantation due to poor mechanical properties. Thus, the goal of an antigen removal process should be to reduce the antigen content of a xenogeneic tissue while preserving its mechanical functionality. To expand the clinical use of antigen-removed xenogeneic tissues as biomechanically functional grafts, it is essential that researchers examine tissue antigen content, ECM composition and architecture, and mechanical properties as new antigen removal processes are developed.

There is a need for improved biomaterials for use in treating non-healing bone defects. A number of natural and synthetic biomaterials have been used for the regeneration of bone tissue with mixed results. One approach is to modify native tissue via decellularization or other treatment for use as natural scaffolding for tissue repair. In this study, our goal was to improve on our previously published alternating solution immersion (ASI) method to fabricate a robust, biocompatible, and mechanically competent biomaterial from natural demineralized bone matrix (DBM). The improved method includes an antigen removal (AR) treatment step which improves mineralization and stiffness while removing unwanted proteins. The chemistry of the mineral in the remineralized bone matrix (RBM) was consistent with dicalcium phosphate dihydrate (brushite), a material used clinically in bone healing applications. Mass spectrometry identified proteins removed from the matrix with AR treatment to include α-2 HS-glycoprotein and osteopontin, noncollagenous proteins (NCPs) and known inhibitors of biomineralization. Additionally, the RBM supported the survival, proliferation, and differentiation of human mesenchymal stromal cells (MSCs) in vitro as well or better than other widely used biomaterials including DBM and PLG scaffolds. DNA content increased more than 10-fold on RBM compared to DBM and PLG; likewise, osteogenic gene expression was significantly increased after 1 and 2 weeks. We demonstrated that ASI remineralization has the capacity to fabricate mechanically stiff and biocompatible RBM, a suitable biomaterial for cell culture applications.

A comparison of transvascular occlusion methods for closing patent ductus arteriosus (PDA) in dogs has not been done.To determine if clinically important differences exist between the approaches and devices currently used.A total of 112 client-owned dogs with left-to-right shunting PDA.Retrospective study. Records from dogs that underwent attempted transvascular PDA occlusion from January 2006 to December 2009 were examined. Dogs were placed into 4 groups: Group 1: Amplatz Canine Duct Occluder (ACDO) (transarterial) - 36 dogs; Group 2: Gianturco or MReye Flipper Detachable Embolization (Flipper) coil (transarterial) - 38 dogs; Group 3: Amplatzer Vascular Plug (AVP) (transarterial) - 23 dogs; Group 4: Flipper coil (transvenous) - 15 dogs.The overall success rate of the procedures was high (92%) with comparable success rates among groups (87-97%). There were significantly fewer complications (P < .0001) in dogs receiving an ACDO than in the remaining groups (3% for ACDO versus 26-33% for the other groups). Fluoroscopy time for the transvenous method was significantly longer (median, 13 minutes) than for the other groups (median, 6 minutes) (P < .0001). Severity of residual flow 24 hours postprocedure was significantly less in the ACDO group than in the remaining groups (P = .0001-.05).The ACDO appears superior in ease of use, complication rate, and completeness of occlusion. The remaining limiting factor with this device is patient size. Until a smaller ACDO device is marketed, coils remain the only choice for interventional closure in very small dogs.

This paper both draws on, and seeks to apply, world-systems analysis to a broad, critical education project that builds mass schooling's potential contribution to the process of world-systemic change. In short, this is done by first setting out the world-systems analysis account of the current state, and period of transition, of the capitalist world-system, followed by some initial consideration of strategies for curricular reform within systems of mass schooling that might contribute to a transition toward a most equal, just and democratic, a socialist, alternative world-system. These considerations intended as contributions to discussion and debate within the critical education community about what might be possible within the boundaries of existing systems of mass schooling, inspired by a world-systems perspective on an uncertain transition toward a non-capitalist future.

World culture theory (WCT) offers an explanatory framework for macro-level comparative analyses of systems of mass education, including their structures, accompanying policies and their curricular and pedagogical practices. WCT has contributed to broader efforts to overcome methodological nationalism in comparative research. In this paper, we acknowledge the contributions of world culture theory in these terms, but develop the case for an alternative explanatory framework--world-systems analysis (WSA)--rooted in the historical development and contemporary crises of the capitalist world-economy. This case is built on two major points of critique of world culture theory: first, that its consensus orientation is inadequate for a macro-level accounting of social reality; and second, that its analysis of the economic functions of mass education, in isolation from the capitalist world-economy, further weakens its explanatory power. Working from this critique, we elaborate the capacity of world-systems analysis to overcome these shortcomings by providing a more comprehensive, historical perspective. This alternative approach incorporates the identification and analysis of shared cultural understandings underpinning policy and institutional practice, linked to the development of the capitalist world-economy. We conclude this paper by affirming the value of WSA as an alternative approach for comparative research, and its potential contribution to the development of more enlightened educational policy and a more just and democratic world-system.

International education is seen as an effective form of soft power. This article reviews one of history's largest and most ambitious attempts to achieve global influence through university education, and to reshape the world--the Soviet university aid program, 1956-91. Drawing on existing research and Soviet archival materials, we lay out and contextualize characteristic features of the Soviet education aid program. Specifically, we identify its focus on students from "developing" and newly independent countries, and its ambition to form graduates who would return home to become national leaders sympathetic to Soviet socialism. We conclude by approaching the program from a world-systems perspective. Here, we highlight the intended catch-up style modernization and national economic development for countries through their participation in the Soviet university aid program as well as the intended development of the human capital of participant countries. The complex impacts on participants throughout the world and their subsequent worldview are the subject of ongoing research by the authors.

Purpose: To investigate the effect of combat-related posttraumatic stress disorder (PTSD) on 4 components underlying text-level reading comprehension. Method: A group of 17 veterans with PTSD and 17 matched control participants took part. An experimental task required participants to read and study 3-sentence paragraphs describing semantic features associated with real and unreal objects. Each paragraph was followed by true-false statements that assessed knowledge access, text memory, inference, and integration. Results: The results revealed that the PTSD group took significantly longer than the control group to study the paragraphs. Although there was no group difference in test statement accuracy, the PTSD group also took significantly longer to respond to the test statements. Conclusions: Overall, the results provide evidence for the control theory of attention but suggest that more direct measures of task-irrelevant processing during text-level reading are needed. More important, the results begin to lay a foundation for developing not only diagnostic but also intervention strategies.

Since the 1970s, using his world-systems analysis, Immanuel Wallerstein has developed a wide-ranging framework for the social sciences, with potential applications for comparative educational research. In this paper we outline key aspects of Wallerstein's theorising, and then analyse the uptake, understandings, and applications of his analysis in the field of comparative and international education, through a case study of the "Comparative Education Review" (CER) journal from 1980 to 2008. This paper examines how, and how widely, his analysis has been adopted and interpreted. Our analysis highlights significant and--given the broader emphasis in comparative education on questions of education and development--surprising absences in the application of this approach. We conclude by arguing for the use and development of three critical features of his analysis in comparative work, as relevant and timely interventions in the field.

The global dominance of neoliberal policy prescriptions in recent decades has been well documented, with particular implications for educational systems. These include reduced public expenditure and provision, the promotion of individual (parental) choice, competition, increased user-pays and the privatisation of education. Against this background, this paper reviews contemporary educational reforms in the Bolivarian Republic of Venezuela, which are moving in a counter direction. In particular, I examine the expansion of publicly funded education, and its overtly politicised objective of preparing citizens to contribute to the Bolivarian socialist project being advanced in the country. Through this counter example, I argue that the Venezuelan case highlights the potential for substantive policy alternatives to neoliberalism into the twenty-first century. (Contains 5 notes.)