Nouh M.,Buffalo Lab
ASME 2016 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2016 | Year: 2016
Periodic elastic structures consisting of self-repeating geometric or material arrangements exhibit unique wave propagation characteristics culminating in frequency stop bands, i.e. ranges of frequency where elastic waves can propagate the periodic medium. Such features make periodic structures appealing for a wide range of vibration suppression and noise control applications. Stop bands in periodic media are achieved via Bragg scattering of elastic which is attributed to impedance mismatches between the different constituents of the self-repeating cells. Stop band frequencies can be numerically predicted using mathematical models which generally utilize the Bloch wave theorem and a transfer matrix method to track the spatial and temporal parameters of the propagating waves from one cell to the next. Such analysis generates what is referred to as the band structure (or the dispersion curves) of the periodic medium which can be used to predict the location of the pass and stop bands. Although capable, these models become significantly more involved when analyzing structures with dissipative constituents and/or material damping and need further adjustments to account for complex elastic moduli and frequency dependent loss factors. A new approach is presented which relies on evaluating structural intensity parameters, such as the active vibrational power and energy transmission paths. It is shown that the steady-state spatial propagation of vibrational power caused by an external disturbance accurately reflects the wave propagation pattern in the periodic medium, and can thus be reverse engineered to numerically predict the stop band frequencies for different degrees of damping via a stop band index (SBI). The developed framework is mathematically applied to a one-dimensional periodic rod to validate the proposed method. Copyright © 2016 by ASME.
Mistriotis P.,Buffalo Lab |
Andreadis S.T.,Buffalo Lab |
Andreadis S.T.,State University of New York at Buffalo |
Andreadis S.T.,Buffalo Center of Excellence
Tissue Engineering - Part B: Reviews | Year: 2013
The adult body harbors powerful reservoirs of stem cells that enable tissue regeneration under homeostatic conditions or in response to disease or injury. The hair follicle (HF) is a readily accessible mini organ within the skin and contains stem cells from diverse developmental origins that were shown to have surprisingly broad differentiation potential. In this review, we discuss the biology of the HF with particular emphasis on the various stem cell populations residing within the tissue. We summarize the existing knowledge on putative HF stem cell markers, the differentiation potential, and technologies to isolate and expand distinct stem cell populations. We also discuss the potential of HF stem cells for drug and gene delivery, tissue engineering, and regenerative medicine. We propose that the abundance of stem cells with broad differentiation potential and the ease of accessibility makes the HF an ideal source of stem cells for gene and cell therapies. © 2013, Mary Ann Liebert, Inc.
Han J.,Buffalo Lab |
Mistriotis P.,Buffalo Lab |
Lei P.,Buffalo Lab |
Wang D.,Roswell Park Cancer Institute |
And 3 more authors.
Stem Cells | Year: 2012
Although the therapeutic potential of mesenchymal stem cells (MSCs) is widely accepted, loss of cell function due to donor aging or culture senescence are major limiting factors hampering their clinical application. Our laboratory recently showed that MSCs originating from older donors suffer from limited proliferative capacity and significantly reduced myogenic differentiation potential. This is a major concern, as the patients most likely to suffer from cardiovascular disease are elderly. Here we tested the hypothesis that a single pluripotency-associated transcription factor, namely Nanog, may reverse the proliferation and differentiation potential of bone marrow-derived MSC (BM-MSC) from adult donors. Microarray analysis showed that adult (a)BM-MSC expressing Nanog clustered close to Nanog-expressing neonatal cells. Nanog markedly upregulated genes involved in cell cycle, DNA replication, and DNA damage repair and enhanced the proliferation rate and clonogenic capacity of aBM-MSC. Notably, Nanog reversed the myogenic differentiation potential and restored the contractile function of aBM-MSC to a similar level as that of neonatal (n)BM-MSC. The effect of Nanog on contractility was mediated - at least in part - through activation of the TGF-β pathway by diffusible factors secreted in the conditioned medium of Nanog-expressing BM-MSC. Overall, our results suggest that Nanog may be used to overcome the effects of organismal aging on aBM-MSC, thereby increasing the potential of MSC from aged donors for cellular therapy and tissue regeneration. © AlphaMed Press.
Bush M.A.,Buffalo Lab |
Bush P.J.,Buffalo Lab |
Sheets H.D.,Canisius College
International Journal of Legal Medicine | Year: 2011
Uniqueness of the human dentition is a fundamental premise in bitemark analysis. Despite the importance of this key aspect of bitemark methodology, systematic studies of large populations have been limited. Furthermore, there have been no investigations of the significance of the third dimension with regard to dental uniqueness. One hundred digitally scanned mandibular models were analyzed in both 2D and three dimension (3D) using Landmark software. Additionally, 500 3D maxillary and mandibular sets were investigated for determining dental match rate. Statistical analysis was performed with geometric morphometric methods. Results show that measurements in 3D preserve more information about the dentition, reducing but not eliminating random matches in a sample population of 100 mandibular dentitions. Examination of pairs of maxillary and mandibular dentitions showed a substantial number of random matches (197 maxillary, 51 mandibular, one of both maxillary and mandibular). Conclusions indicate that a zero match rate cannot be claimed for the population studied. © Springer-Verlag 2010.
Bush M.A.,Buffalo Lab |
Bush P.J.,Buffalo Lab |
Sheets H.D.,Canisius College
Journal of Forensic Sciences | Year: 2011
Recent scrutiny of forensic science has focused on unreliability of expert witness testimony when based on statements of individuality. In bitemark analysis, assumptions regarding uniqueness of the dentition have been based on use of the product rule while ignoring correlation and nonuniformity of dental arrangement. To examine the effect of these factors, two separate sets of scanned dental models (n = 172 and n = 344) were measured and statistically tested to determine match rates. Results were compared to those of a prior study. Seven and 16 matches of the six anterior lower teeth were found in the respective data sets. Correlations and nonuniform distributions of tooth positions were observed. Simulation tests were performed to verify results. Results indicate that given experimental measurement parameters, statements of dental uniqueness with respect to bitemark analysis in an open population are unsupportable and that use of the product rule is inappropriate. © 2010 American Academy of Forensic Sciences.
Guskey M.T.,Buffalo Lab |
Tsuji B.T.,Buffalo Lab |
Tsuji B.T.,Roswell Park Cancer Institute
Pharmacotherapy | Year: 2010
Resistance to antibiotics among gram-positive bacteria, especially enterococci and staphylococci, has led to the need to develop new antibiotics. Vancomycin, a glycopeptide antibiotic, has been used for over 3 decades to treat serious methicillin-resistant Staphylococcus aureus infections. The increased frequency of multidrug-resistant bacteria, especially vancomycin-resistant strains, has focused interest on three new lipoglycopeptides for the treatment of infections caused by gram-positive bacteria: oritavancin, dalbavancin, and telavancin. Although oritavancin and dalbavancin are still in development, telavancin received approval from the United States Food and Drug Administration in September 2009 for treatment of complicated skin and skin structure infections. Structurally different from vancomycin and teicoplanin, all three lipoglycopeptides have greater potency and less potential for development of resistant organisms. Of particular importance is the activity of oritavancin, dalbavancin, and telavancin against vancomycin-resistant organisms. In addition, the pharmacokinetic properties of these new antimicrobials substantially differ from those of vancomycin. Both oritavancin and dalbavancin have long terminal half-lives, which may allow for infrequent dosing. In addition, oritavancin is primarily cleared through hepatic pathways, which makes it potentially useful in patients with renal compromise. In animal models, these new lipoglycopeptides were effective in treating serious gram-positive infections, including complicated skin and skin structure infections, endocarditis, bacteremia, and pneumonia; in clinical studies, however, efficacy was shown only in complicated skin and skin structure infections for all three agents. According to preliminary data, the adverse-effect profile of these lipoglycopeptides is generally similar to that of drugs currently used to treat severe gram-positive infections. However, further evaluation and monitoring is necessary as more patients are exposed to these agents. As antimicrobial resistance continues to increase worldwide, the lipoglycopeptides may provide clinicians with a useful antimicrobial in the continued fight against multidrug-resistant gram-positive bacteria.
Kim C.,Buffalo Lab |
Jeon M.,Buffalo Lab |
Wang L.V.,Washington University in St. Louis
Optics Letters | Year: 2011
We demonstrate the feasibility of a novel and nonionizing process for bladder imaging in vivo, called photoacoustic cystography (PAC). Using a photoacoustic imaging system, we have successfully imaged a rat bladder filled with clinically used Methylene Blue (MB) dye. An image contrast of ∼8 was achieved. Further, spectroscopic PAC confirmed the accumulation of MB in the bladder. Using a laser pulse energy of less than 1 mJ/cm2 (1/20 of the ANSI safety limit), a deeply (1:2 cm) positioned bladder in biological tissues was clearly visible in the PA image. Our results suggest that PAC can potentially provide a nonionizing, relatively cheap, and portable tool for bladder mapping. Among our clinical interests, nonionizing PAC with an injection of MB can potentially monitor vesicoureteral reflux in children. © 2011 Optical Society of America.
Lee Y.,Buffalo Lab |
Basaran C.,Buffalo Lab
Computational Materials Science | Year: 2013
Viscoplasticity in β-Sn lattice and grain boundaries is studied at the atomic level. Two kinds of β-Sn lattice structures are studied. Model I is the perfect β-Sn lattice structure in  orientation. Model II is β-Sn lattice structure with several symmetric tilt grain boundaries. The β-Sn models are simulated by Molecular Dynamics (MD) simulation package, LAMMPS. Modified Embedded-Atom Method (MEAM) is employed for the β-Sn potential. In order to study the effects of strain rate on β-Sn, a range of strain rates are applied. Simulation is conducted for NVT ensemble. Thermal effects are also studied. The results of molecular dynamics simulations are compared with experimental data of viscoplastic behavior of bulk tin. © 2012 Elsevier B.V. All rights reserved.
Mesmer B.L.,Buffalo Lab |
Bloebaum C.L.,Buffalo Lab
Safety Science | Year: 2012
The importance of the incorporation of personal communication devices in emergency evacuation simulators will be discussed. Four case studies are examined to identify usage statistics and human behavior when using the devices in an emergency. The case studies are: 9/11 World Trade Center Attacks, London train bombings, Virginia Tech shooting and United Flight #93. The case studies' findings are implemented into the Vacate evacuation simulator, which uses particle swarm optimization to mimic human pedestrian behavior. The physical actions of using a device, as well as the reaction to the information transmitted during usage, are examined. Findings show that the effects of the personal communication devices can affect individuals that are close to the user of the device, as well as those not in the local vicinity of the user. These effects, combined with the rapid mainstream acceptance of communication technologies, justify the implementation of personal communication devices into evacuation simulators. © 2011 Elsevier Ltd.