Theoretical performance of cross-wind axis turbines with results for a catenary vertical axis configuration

A general analysis capable of predicting performance characteristics of cross-wind axis turbines was developed, including the effects of airfoil geometry, support struts, blade aspect ratio, windmill solidity, blade interference and curved flow. The results were compared with available wind tunnel results for a catenary blade shape. A theoretical performance curve for an aerodynamically efficient straight blade configuration was also presented. In addition, a linearized analytical solution applicable for straight configurations was developed. A listing of the computer program developed for numerical solutions of the general performance equations is included in the appendix

Using molecular imaging to assess the delivery and infection of protease activated virus in animal model of myocardial infarction

Cardiovascular diseases remain the greatest cause of death in the US and gene therapy has the potential to be an effective therapy. In this study, we demonstrated MMP-9 based protease-activatable virus (PAV) for selective infection of myocardial infarct (MI) that is associated with active MMP-9 expression. To test the specificity of PAV, we used expression of a far-red fluorescence protein (iRFP) delivered by the PAV together with a dual PET/NIRF imaging agent specific for active MMP-9 activity at the site of MI in a murine model. Calibrated fluorescence imaging employed a highly-sensitive intensified camera, laser diode excitation sources, and filtration schemes based upon the spectra of iRFP and the NIRF agent. One to two days after ligation of the left anterior descending artery, the PAV or WT AAV9 virus encoding for iRFP (5x1010 genomic particles) and radiolabeled MMP-9 imaging agent (3 nmol) were injected intravenously (i.v.). PET imaging showed MMP activity was associated with adverse tissue remodeling at the site of the MI. One week after, animals were again injected i.v. with the MMP-9 agent (3 nmol) and 18-24 h later, the animals were euthanized and the hearts were harvested, sliced, and imaged for congruent iRFP transgene expression and NIRF signals associated with MMP-9 tissue activity. The fluorescent margins of iRFP and NIRF contrasted tissues were quantified in terms Standard International units of mW/cm2/sr. The sensitivity, specificity, and accuracy of PAV and WT targeting to sites of MI was determined from these calibrated fluorescence measurements. The PAV demonstrated significantly higher delivery performance than that of the WT AAV9 virus

Edge phonons in black phosphorus

Exfoliated black phosphorus has recently emerged as a new two-dimensional crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have potentially important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and the behavior of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.Comment: 15 pages, 4 figure

Advancing the translation of optical imaging agents for clinical imaging

Despite the development of a large number of promising candidates, few contrast agents for established medical imaging modalities have successfully been translated over the past decade. The emergence of new imaging contrast agents that employ biomedical optics is further complicated by the relative infancy of the field and the lack of approved imaging devices compared to more established clinical modalities such as nuclear medicine. Herein, we propose a navigational approach (as opposed to a fixed “roadmap”) for translation of optical imaging agents that is (i) proposed through consensus by four academic research programs that are part of the cooperative U54 NCI Network for Translational Research, (ii) developed through early experiences for translating optical imaging agents in order to meet distinctly varied needs in cancer diagnostics, and (iii) adaptable to the rapidly changing environment of academic medicine. We describe the pathways by which optical imaging agents are synthesized, qualified, and validated for preclinical testing, and ultimately translated for “first-in-humans” studies using investigational optical imaging devices. By identifying and adopting consensus approaches for seemingly disparate optical imaging modalities and clinical indications, we seek to establish a systematic method for navigating the ever-changing “roadmap” to most efficiently arrive at the destination of clinical adoption and improved outcome and survivorship for cancer patients

Human bone marrow mesenchymal stem cell-derived extracellular vesicles attenuate neuroinflammation evoked by focal brain injury in rats

Background Ischemic stroke is the major cause of long-term severe disability and death in aged population. Cell death in the infarcted region of the brain induces immune reaction leading to further progression of tissue damage. Immunomodulatory function of mesenchymal stem cells (MSCs) has been shown in multiple preclinical studies; however, it has not been successfully translated to a routine clinical practice due to logistical, economical, regulatory, and intellectual property obstacles. It has been recently demonstrated that therapeutic effect of intravenously administered MSCs can be recapitulated by extracellular vesicles (EVs) derived from them. However, in contrast to MSCs, EVs were not capable to decrease stroke-induced neuroinflammation. Therefore, the aim of the study was to investigate if intra-arterial delivery of MSC-derived EVs will have stronger impact on focal brain injury-induced neuroinflammation, which mimics ischemic stroke, and how it compares to MSCs. Methods The studies were performed in adult male Wistar rats with focal brain injury induced by injection of 1 mu l of 50 nmol ouabain into the right hemisphere. Two days after brain insult, 5 x 10(5) human bone marrow MSCs (hBM-MSCs) labeled with Molday ION or 1.3 x 10(9) EVs stained with PKH26 were intra-arterially injected into the right hemisphere under real-time MRI guidance. At days 1, 3, and 7 post-transplantation, the rats were decapitated, the brains were removed, and the presence of donor cells or EVs was analyzed. The cellular immune response in host brain was evaluated immunohistochemically, and humoral factors were measured by multiplex immunoassay. Results hBM-MSCs and EVs transplanted intra-arterially were observed in the rat ipsilateral hemisphere, near the ischemic region. Immunohistochemical analysis of brain tissue showed that injection of hBM-MSCs or EVs leads to the decrease of cell activation by ischemic injury, i.e., astrocytes, microglia, and infiltrating leucocytes, including T cytotoxic cells. Furthermore, we observed significant decrease of pro-inflammatory cytokines and chemokines after hBM-MSC or EV infusion comparing with non-treated rats with focal brain injury. Conclusions Intra-arterially injected EVs attenuated neuroinflammation evoked by focal brain injury, which mimics ischemic stroke, and this effect was comparable to intra-arterial hBM-MSC transplantation. Thus, intra-arterial injection of EVs might be an attractive therapeutic approach, which obviates MSC-related obstacles