Reverse Doppler Effect of Sound

We report observation of reverse Doppler effect in a double negative acoustic metamaterial. The metamaterial exhibited negative phase velocity and positive group velocity. The dispersion relation is such that the wavelength corresponding to higher frequency is longer. We observed that the frequency was down-shifted for the approaching source, and up-shifted when the source receded

Development of Laser Ruler in Rigid Laryngoscope

ObjectivesThe objective of this study was to develop a new device that provides a simple, noninvasive method of measuring accurate lesion size while using an endoscope.MethodsWe developed a rigid laryngoscope with a built-in laser-ruler using a one-light emitting diode and an acrylic plate. The invention incorporates a built-in laser diode that projects an auto-parallel beam into the optical path of the rigid laryngoscope to form two spots in the field of view.ResultsWhile the interspot distance remains consistent despite changes in focal plane, magnification, or viewing angle of the laryngoscope, projection to an uneven surface introduces certain variations in the shape, and size of the spots, and the distance between the two spots.ConclusionThe device enables a laryngologist to easily measure the distance between landmarks, as well as the change in real size, and the progressive change of vocal fold lesions in an outpatient setting

Expression of VEGF, HGF, IL-6, IL-8, MMP-9, Telomerase in Peripheral Blood of Patients with Head and Neck Squamous Cell Carcinoma

ObjectivesThis study investigated the telomerase expression in peripheral blood mononuclear cells (PBMCs) and the relationship between the serum level of several soluble factors such as vascular endothelial growth factor (VEGF), hepatocyte growth factor, interleukin (IL)-6, IL-8, and matrix metallopeptidase-9 and the clinicopathological features of patients with head and neck squamous cell carcinoma (HNSCC).MethodsPeripheral blood samples were collected from 50 HNSCC patients and 15 normal controls. The telomerase activity in the PBMCs was measured by Telomere Repeat Amplification Protocols. The serum levels of the soluble factors were analyzed by enzyme-linked immunosorbent assay.ResultsThe expression of telomerase in the PBMCs of HNSCC patients was significantly correlated with the N and American Joint Committee on Cancer (AJCC) stages. The serum VEGF level was significantly higher in the patients with an advanced T stage, N stage and AJCC stage. Serum VEGF was significantly related with the expression of telomerase in the PBMCs. The telomerase expression and the VEGF expression were shown to be independent factors associated with poor survival.ConclusionThe telomerase expression in the PBMCs and the serum VEGF level of HNSCC patients were significantly correlated with the N stage, the AJCC stage and the prognosis

Brief Report: Human Perivascular Stem Cells and Nel-Like Protein-1 Synergistically Enhance Spinal Fusion in Osteoporotic Rats

Autologous bone grafts (ABGs) are considered as the gold standard for spinal fusion. However, osteoporotic patients are poor candidates for ABGs due to limited osteogenic stem cell numbers and function of the bone microenvironment. There is a need for stem cell-based spinal fusion of proven efficacy under either osteoporotic or nonosteoporotic conditions. The purpose of this study is to determine the efficacy of human perivascular stem cells (hPSCs), a population of mesenchymal stem cells isolated from adipose tissue, in the presence and absence of NELL-1, an osteogenic protein, for spinal fusion in the osteoporosis. Osteogenic differentiation of hPSCs with and without NELL-1 was tested in vitro. The results indicated that NELL-1 significantly increased the osteogenic potential of hPSCs in both osteoporotic and nonosteoporotic donors. Next, spinal fusion was performed by implanting scaffolds with regular or high doses of hPSCs, with or without NELL-1 in ovariectomized rats (n = 41). Regular doses of hPSCs or NELL-1 achieved the fusion rates of only 20%-37.5% by manual palpation. These regular doses had previously been shown to be effective in nonosteoporotic rat spinal fusion. Remarkably, the high dose of hPSCs+NELL-1 significantly improved the fusion rates among osteoporotic rats up to approximately 83.3%. Microcomputed tomography imaging and quantification further confirmed solid bony fusion with high dose hPSCs+NELL-1. Finally, histologically, direct in situ involvement of hPSCs in ossification was shown using undecalcified samples. To conclude, hPSCs combined with NELL-1 synergistically enhances spinal fusion in osteoporotic rats and has great potential as a novel therapeutic strategy for osteoporotic patients. © 2015 AlphaMed Press

Effect of Botulinum Toxin Type A on a Rat Surgical Wound Model

ObjectivesThe tension on a wound is one of the important factors that determine the degree of fibrosis and scar formation. We hypothesized that local botulinum toxin type A (Botox) induced paralysis of the musculature subjacent to a surgical wound with a skin defect would minimize the repetitive tensile forces on the surgical wound's edges, and this will result in a decreased fibroplastic response and fibrosis of the wound.MethodsThis is a prospective randomized experimental study. Two distinct surgical wounds were made to the dorsum of 15 adult rats, respectively. One of the 2 wounds was injected with Botox, and the other wound was used as a control, and this was done for all the rats' wounds. We evaluated the wound size, the degree of fibrosis and inflammation, the blood vessel proliferation, the thickness of the wound and the expression of transforming growth factor (TGF)-β1 in the wounds.ResultsThere were significant differences of wound size at the 3rd and 4th week between the Botox and control groups (P<0.05). The Botox group showed less infiltration of inflammatory cells than the control group at the 2nd week (P<0.05). The Botox group showed a smaller number of fibroblasts and less fibrosis than the control group at the 4th week (P<0.05). The Botox group showed much strong collagen density than the control group at the 8th week (P<0.05). For the immunohistochemical staining, there was a lower transforming growth factor (TGF)-β1 expression in the Botox group than that of the control group at the 4th week (P<0.05).ConclusionThe wounds of the Botox-treated group showed a larger wound size, less infiltration of inflammatory cells and less fibrosis, a much greater amount of collagen and a lower expression of TGF-β1 than did the control group. Botox might be used to decrease the fibrosis of a surgical wound without damaging the epithelial growth in situations for which decreased fibrosis is necessary, such as for treating laryngeal, tracheal and nasal stenosis

Acoustic Metameterial with Negative Modulus

We present experimental and theoretical results on an acoustic metamaterial that exhibits negative effective modulus in a frequency range from 0 to 450 Hz. One-dimensional acoustic metamaterial with an array of side holes on a tube was fabricated. We observed that acoustic waves above 450 Hz propagated well in this structure, but no sound below 450 Hz passed through. The frequency characteristics of the metamaterial has the same form as that of the permittivity in metals due to the plasma oscillation. We also provide a theory to explain the experimental results

Aldose Reductase Inhibitor Ameliorates Renal Vascular Endothelial Growth Factor Expression in Streptozotocin-Induced Diabetic Rats

PURPOSE: The vascular endothelial growth factor (VEGF) expression of podocyte is one of the well-known major factors in development of diabetic nephropathy. In this study, we investigated the effects of aldose reductase inhibitor, fidarestat on diabetic nephropathy, and renal VEGF expression in a type 1 diabetic rat model. MATERIALS AND METHODS: Twenty four Sprague-Dawley male rats which were performed intraperitoneal injection of streptozotocin and normal six rats were divided into four groups including a normal control group, untreated diabetic control group, aldose reductase (AR) inhibitor (fidarestat, 16 mg kg(-1) day(-1)) treated diabetic group, and angiotensin receptor blocker (losartan, 20 mg kg(-1) day(-1)) treated diabetic group. We checked body weights and blood glucose levels monthly and measured urine albumin-creatinine ratio (ACR) at 8 and 32 weeks. We extracted the kidney to examine the renal morphology and VEGF expressions. RESULTS: The ACR decreased in fidarestat and losartan treated diabetic rat groups than in untreated diabetic group (24.79 +/- 11.12, 16.11 +/- 9.95, and 84.85 +/- 91.19, p < 0.05). The renal VEGF messenger RNA (mRNA) and protein expression were significantly decreased in the fidarestat and losartan treated diabetic rat groups than in the diabetic control group. CONCLUSION: We suggested that aldose reductase inhibitor may have preventive effect on diabetic nephropathy by reducing renal VEGF overexpression.ope

Selecting utilities placement techniques in urban underground engineering

Placement of utilities has not been generally accomplished in any sustainable technique resulting in a veritable maze in high density urban areas. As underground space scarcity grows in our cities due to the increasing demands for utility services, subsurface facilities such as utility tunnels are becoming more efficient in providing the required infrastructure. There is a growing public awareness of aesthetic considerations and impatience with street cuts and their associated costs, traffic interferences, noise and accidental utility cuts. Unfortunately the lack of data and the difficulty in quantifying the intangibles has made it impossible to arrive at a reasonably accurate figure of overall negative impact on the urban environment of street cuts. Due to this, current practices of traditional trenching depending only on cost indicators remain as first option in urban planning instead of more sustainable techniques, like utility tunnels. However, it is well known that intangible costs to the public and the utilities might make the utility tunnel concept to be economically feasible in the long run. This paper presents a methodology based on AHP and Delphi processes for the selection of utilities placement techniques in which the intangibles are also assessed to avoid short-sighted urban underground planning.Curiel Esparza, J.; Cantó Perelló, J. (2013). Selecting utilities placement techniques in urban underground engineering. Archives of Civil and Mechanical Engineering. 13(2):276-285. doi:10.1016/j.acme.2013.02.001S27628513