Leaching of arsenic, copper and chromium from thermally treated soil.

Science.gov (United States)

Kumpiene, Jurate; Nordmark, Désirée; Hamberg, Roger; Carabante, Ivan; Simanavičienė, Rūta; Aksamitauskas, Vladislovas Česlovas

2016-12-01

Thermal treatment, if properly performed, is an effective way of destroying organic compounds in contaminated soil, while impact on co-present inorganic contaminants varies depending on the element. Leaching of trace elements in thermally treated soil can be altered by co-combusting different types of materials. This study aimed at assessing changes in mobility of As, Cr and Cu in thermally treated soil as affected by addition of industrial by-products prior to soil combustion. Contaminated soil was mixed with either waste of gypsum boards, a steel processing residue (Fe 3 O 4 ), fly ash from wood and coal combustion or a steel abrasive (96.5% Fe 0 ). The mixes and unamended soil were thermally treated at 800 °C and divided into a fine fraction 0.125 mm to simulate particle separation occurring in thermal treatment plants. The impact of the treatment on element behaviour was assessed by a batch leaching test, X-ray absorption spectroscopy and dispersive X-ray spectrometry. The results suggest that thermal treatment is highly unfavourable for As contaminated soils as it increased both the As leaching in the fine particle size fraction and the mass of the fines (up to 92%). Soil amendment with Fe-containing compounds prior to the thermal treatment reduced As leaching to the levels acceptable for hazardous waste landfills, but only in the coarse fraction, which does not justify the usefulness of such treatment. Among the amendments used, gypsum most effectively reduced leaching of Cr and Cu in thermally treated soil and could be recommended for soils that do not contain As. Fly ash was the least effective amendment as it increased leaching of both Cr and As in majority of samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

Science.gov (United States)

Liu, Ran; Wang, Jia; Liu, Jing

2015-07-01

Hyperthermia (42-46°C), treatment of tumor tissue through elevated temperature, offers several advantages including high cost-effectiveness, highly targeted ablation and fewer side effects and hence higher safety level over traditional therapies such as chemotherapy and radiotherapy. Recently, hyperthermia using heat release through exothermic acid-base neutralization comes into view owing to its relatively safe products of salt and water and highly confined ablation. However, lack of quantitative understanding of the spatial and temporal temperature profiles that are produced by simultaneous diffusion of liquid chemical and its chemical reaction within tumor tissue impedes the application of this method. This article is dedicated to quantify thermal ablation effects of acid and base both individually and as in neutralization via infrared captured thermal images. A theoretical model is used to approximate specific heat absorption rate (SAR) based on experimental measurements that contrast two types of tissue, normal pork and pig liver. According to the computation, both pork and liver tissue has a higher ability in absorbing hydrochloric acid (HCl) than sodium hydroxide, hence suggesting that a reduced dosage for HCl is appropriate in a surgery. The heating effect depends heavily on the properties of tissue types and amount of chemical reagents administered. Given thermal parameters such as SAR for different tissues, a computational model can be made in predicting temperature transitions which will be helpful in planning and optimizing surgical hyperthermia procedures.

Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

Directory of Open Access Journals (Sweden)

Ran Liu

2015-07-01

Full Text Available Hyperthermia (42-46°C, treatment of tumor tissue through elevated temperature, offers several advantages including high cost-effectiveness, highly targeted ablation and fewer side effects and hence higher safety level over traditional therapies such as chemotherapy and radiotherapy. Recently, hyperthermia using heat release through exothermic acid-base neutralization comes into view owing to its relatively safe products of salt and water and highly confined ablation. However, lack of quantitative understanding of the spatial and temporal temperature profiles that are produced by simultaneous diffusion of liquid chemical and its chemical reaction within tumor tissue impedes the application of this method. This article is dedicated to quantify thermal ablation effects of acid and base both individually and as in neutralization via infrared captured thermal images. A theoretical model is used to approximate specific heat absorption rate (SAR based on experimental measurements that contrast two types of tissue, normal pork and pig liver. According to the computation, both pork and liver tissue has a higher ability in absorbing hydrochloric acid (HCl than sodium hydroxide, hence suggesting that a reduced dosage for HCl is appropriate in a surgery. The heating effect depends heavily on the properties of tissue types and amount of chemical reagents administered. Given thermal parameters such as SAR for different tissues, a computational model can be made in predicting temperature transitions which will be helpful in planning and optimizing surgical hyperthermia procedures.

Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

Energy Technology Data Exchange (ETDEWEB)

Liu, Ran, E-mail: jliubme@tsinghua.edu.cn, E-mail: liuran@tsinghua.edu.cn; Liu, Jing, E-mail: jliubme@tsinghua.edu.cn, E-mail: liuran@tsinghua.edu.cn [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China); Wang, Jia [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States)

2015-07-15

Hyperthermia (42-46°C), treatment of tumor tissue through elevated temperature, offers several advantages including high cost-effectiveness, highly targeted ablation and fewer side effects and hence higher safety level over traditional therapies such as chemotherapy and radiotherapy. Recently, hyperthermia using heat release through exothermic acid-base neutralization comes into view owing to its relatively safe products of salt and water and highly confined ablation. However, lack of quantitative understanding of the spatial and temporal temperature profiles that are produced by simultaneous diffusion of liquid chemical and its chemical reaction within tumor tissue impedes the application of this method. This article is dedicated to quantify thermal ablation effects of acid and base both individually and as in neutralization via infrared captured thermal images. A theoretical model is used to approximate specific heat absorption rate (SAR) based on experimental measurements that contrast two types of tissue, normal pork and pig liver. According to the computation, both pork and liver tissue has a higher ability in absorbing hydrochloric acid (HCl) than sodium hydroxide, hence suggesting that a reduced dosage for HCl is appropriate in a surgery. The heating effect depends heavily on the properties of tissue types and amount of chemical reagents administered. Given thermal parameters such as SAR for different tissues, a computational model can be made in predicting temperature transitions which will be helpful in planning and optimizing surgical hyperthermia procedures.

Subsurface thermal behaviour of tissue mimics embedded with large blood vessels during plasmonic photo-thermal therapy.

Science.gov (United States)

Paul, Anup; Narasimhan, Arunn; Das, Sarit K; Sengupta, Soujit; Pradeep, Thalappil

2016-11-01

The purpose of this study was to understand the subsurface thermal behaviour of a tissue phantom embedded with large blood vessels (LBVs) when exposed to near-infrared (NIR) radiation. The effect of the addition of nanoparticles to irradiated tissue on the thermal sink behaviour of LBVs was also studied. Experiments were performed on a tissue phantom embedded with a simulated blood vessel of 2.2 mm outer diameter (OD)/1.6 mm inner diameter (ID) with a blood flow rate of 10 mL/min. Type I collagen from bovine tendon and agar gel were used as tissue. Two different nanoparticles, gold mesoflowers (AuMS) and graphene nanostructures, were synthesised and characterised. Energy equations incorporating a laser source term based on multiple scattering theories were solved using finite element-based commercial software. The rise in temperature upon NIR irradiation was seen to vary according to the position of the blood vessel and presence of nanoparticles. While the maximum rise in temperature was about 10 °C for bare tissue, it was 19 °C for tissue embedded with gold nanostructures and 38 °C for graphene-embedded tissues. The axial temperature distribution predicted by computational simulation matched the experimental observations. A different subsurface temperature distribution has been obtained for different tissue vascular network models. The position of LBVs must be known in order to achieve optimal tissue necrosis. The simulation described here helps in predicting subsurface temperature distributions within tissues during plasmonic photo-thermal therapy so that the risks of damage and complications associated with in vivo experiments and therapy may be avoided.

Thermal damage control of dye-assisted laser tissue welding: effect of dye concentration

Science.gov (United States)

Xie, Hua; Buckley, Lisa A.; Prahl, Scott A.; Shaffer, Brian S.; Gregory, Kenton W.

2001-05-01

Successful laser-assisted tissue welding was implemented to provide proper weld strength with minimized tissue thermal injury. We investigated and compared the weld strengths and morphologic changes in porcine small intestinal submucose (SIS) and porcine ureteral tissues with various concentration of indocyanine green (ICG) and with a solid albumin sheet. The study showed that the tissues were welded at lower ICG concentration (0.05 mM) with minimized tissue thermal damage using an 800-nm wavelength diode laser.

Measurement of tissue-radiation dosage using a thermal steady-state elastic shear wave.

Science.gov (United States)

Chang, Sheng-Yi; Hsieh, Tung-Sheng; Chen, Wei-Ru; Chen, Jin-Chung; Chou, Chien

2017-08-01

A biodosimeter based on thermal-induced elastic shear wave (TIESW) in silicone acellular porcine dermis (SAPD) at thermal steady state has been proposed and demonstrated. A square slab SAPD treated with ionizing radiation was tested. The SAPD becomes a continuous homogeneous and isotropic viscoelastic medium due to the generation of randomly coiled collagen fibers formed from their bundle-like structure in the dermis. A harmonic TIESW then propagates on the surface of the SAPD as measured by a nanometer-scaled strain-stress response under thermal equilibrium conditions at room temperature. TIESW oscillation frequency was noninvasively measured in real time by monitoring the transverse displacement of the TIESW on the SAPD surface. Because the elastic shear modulus is highly sensitive to absorbed doses of ionizing radiation, this proposed biodosimeter can become a highly sensitive and noninvasive method for quantitatively determining tissue-absorbed dosage in terms of TIESW’s oscillation frequency. Detection sensitivity at 1 cGy and dynamic ranges covering 1 to 40 cGy and 80 to 500 cGy were demonstrated.

Pre-treating water with non-thermal plasma

Science.gov (United States)

Cho, Young I.; Fridman, Alexander; Rabinovich, Alexander; Cho, Daniel J.

2017-07-04

The present invention consists of a method of pre-treatment of adulterated water for distillation, including adulterated water produced during hydraulic fracturing ("fracking") of shale rock during natural gas drilling. In particular, the invention is directed to a method of treating adulterated water, said adulterated water having an initial level of bicarbonate ion in a range of about 250 ppm to about 5000 ppm and an initial level of calcium ion in a range of about 500 ppm to about 50,000 ppm, said method comprising contacting the adulterated water with a non-thermal arc discharge plasma to produce plasma treated water having a level of bicarbonate ion of less than about 100 ppm. Optionally, the plasma treated water may be further distilled.

Characterization of Physical and Thermal Properties of Biofield Treated Neopentyl Glycol

OpenAIRE

Trivedi , Mahendra Kumar; Tallapragada , Rama Mohan; Branton , Alice; Trivedi , Dahryn; Nayak , Gopal; Mishra , Rakesh; Jana , Snehasis

2015-01-01

International audience; Neopentyl glycol (NPG) has been extensively used as solid-solid phase change materials (PCMs) for thermal energy storage applications. The objective of the present study was to evaluate the impact of biofield treatment on physical, spectral and thermal properties of NPG. The study was performed in two groups (control and treated). The control group remained as untreated, and treatment group was subjected to Mr. Trivedi’s biofield treatment. The control and treated NPG ...

MR-guided noninvasive thermal coagulation of in-vivo liver tissue using ultrasonic phased array

Science.gov (United States)

Daum, Douglas R.; Smith, Nadine; McDannold, Nathan; Hynynen, Kullervo H.

1999-05-01

Magnetic resonance (MR) imaging was used to guide and monitor the thermal tissue coagulation of in vivo porcine tissue using a 256 element ultrasonic phased array. The array could coagulate tissue volumes greater than 2 cm3 in liver and 0.5 cm3 in kidney using a single 20 second sonication. This sonication used multiple focus fields which were temporally cycled to heat large tissue volumes simultaneously. Estimates of the coagulated tissue using a thermal dose threshold compare well with T2-weighted images of post sonication lesions. The overlapping large focal volumes could aid in the treatment of large tumor volumes which require multiple overlapping sonications. The ability of MR to detect the presence and undesirable thermal increases at acoustic obstacle such as cartilaginous and bony ribs is demonstrated. This could have a significant impact on the ability to monitor thermal treatments of the liver and other organs which are acoustically blocked.

Characterization of Physical and Thermal Properties of Biofield Treated Neopentyl Glycol

OpenAIRE

Trivedi, Dahryn; Trivedi, Mahendra Kumar; Branton, Alice; Nayak, Gopal

2015-01-01

Neopentyl glycol (NPG) has been extensively used as solid-solid phase change materials (PCMs) for thermal energy storage applications. The objective of the present study was to evaluate the impact of biofield treatment on physical, spectral and thermal properties of NPG. The study was performed in two groups (control and treated). The control group remained as untreated, and treatment group was subjected to Mr. Trivedi’s biofield treatment. The control and treated NPG were characterized by X-...

Effectiveness of thermal annular procedures in treating discogenic low back pain.

Science.gov (United States)

Helm Ii, Standiford; Deer, Timothy R; Manchikanti, Laxmaiah; Datta, Sukdeb; Chopra, Pradeep; Singh, Vijay; Hirsch, Joshua A

2012-01-01

Persistent low back pain refractory to conservative treatment is a common problem that leads to widespread impairment, resulting in significant costs to society. The intervertebral disc is a major source of persistent low back pain. Technologies developed to treat this problem, including various surgical instrumentation and fusion techniques, have not reliably provided satisfactory results in terms of either pain relief or increased function. Thermal annular procedures (TAPs) were first developed in the late 1990s in an attempt to treat discogenic pain. The hope was that they would provide greater value than fusion in terms of efficacy, morbidity, and cost. Three technologies have been developed to apply heat to the annulus: intradiscal electrothermal therapy (IDET), discTRODE, and biacuplasty. Since nerve ingrowth and tissue regeneration in the annulus is felt to be the source of pain in discogenic low back pain, when describing the 3 above techniques we use the term "thermal annular procedures" rather than "thermal intradiscal procedures." We have specifically excluded studies treating the nucleus. TAPs have been the subject of significant controversy. Multiple reviews have been conducted resulting in varying conclusions. A systematic review of TAPs for the treatment of discogenic low back pain. To evaluate the effectiveness of TAPs in treating discogenic low back pain and to assess complications associated with those procedures. The available literature on TAPs in treating discogenic low back pain was reviewed. The quality assessment and clinical relevance criteria utilized were the Cochrane Musculoskeletal Review Group criteria for interventional techniques for randomized trials, and the criteria developed by the Newcastle-Ottawa Scale criteria for observational studies. The level of evidence was classified as good, fair, or poor based on the quality of evidence developed by the U.S. Preventive Services Task Force. Data sources included relevant literature

Computer modeling of the combined effects of perfusion, electrical conductivity, and thermal conductivity on tissue heating patterns in radiofrequency tumor ablation.

Science.gov (United States)

Ahmed, Muneeb; Liu, Zhengjun; Humphries, Stanley; Goldberg, S Nahum

2008-11-01

could not be achieved at higher inner/outer perfusions (>4 kg/m(3)-s). For varied electrical conductivities in the setting of varied perfusion, greatest RF heating occurred for inner electrical conductivities simulating injection of saline around the electrode with an outer electrical conductivity of soft tissue, and the least amount of heating occurring while simulating renal cell carcinoma in normal kidney. Characterization of these scenarios demonstrated the role of electrical and thermal conductivity interactions, with the greatest differences in effect seen in the 3-4 cm tumor range, as almost all 2 cm tumors and almost no 5 cm tumors could be treated. Optimal combinations of thermal and electrical conductivity can partially negate the effect of perfusion. For clinically relevant tumor sizes, thermal and electrical conductivity impact which tumors can be successfully ablated even in the setting of almost non-existent perfusion.

High accuracy thermal conductivity measurement of aqueous cryoprotective agents and semi-rigid biological tissues using a microfabricated thermal sensor

Science.gov (United States)

Liang, Xin M.; Sekar, Praveen K.; Zhao, Gang; Zhou, Xiaoming; Shu, Zhiquan; Huang, Zhongping; Ding, Weiping; Zhang, Qingchuan; Gao, Dayong

2015-01-01

An improved thermal-needle approach for accurate and fast measurement of thermal conductivity of aqueous and soft biomaterials was developed using microfabricated thermal conductivity sensors. This microscopic measuring device was comprehensively characterized at temperatures from 0 °C to 40 °C. Despite the previous belief, system calibration constant was observed to be highly temperature-dependent. Dynamic thermal conductivity response during cooling (40 °C to –40 °C) was observed using the miniaturized single tip sensor for various concentrations of CPAs, i.e., glycerol, ethylene glycol and dimethyl sulfoxide. Chicken breast, chicken skin, porcine limb, and bovine liver were assayed to investigate the effect of anatomical heterogeneity on thermal conductivity using the arrayed multi-tip sensor at 20 °C. Experimental results revealed distinctive differences in localized thermal conductivity, which suggests the use of approximated or constant property values is expected to bring about results with largely inflated uncertainties when investigating bio-heat transfer mechanisms and/or performing sophisticated thermal modeling with complex biological tissues. Overall, the presented micro thermal sensor with automated data analysis algorithm is a promising approach for direct thermal conductivity measurement of aqueous solutions and soft biomaterials and is of great value to cryopreservation of tissues, hyperthermia or cryogenic, and other thermal-based clinical diagnostics and treatments. PMID:25993037

Tissue engineering as a potential alternative or adjunct to surgical reconstruction in treating pelvic organ prolapse

DEFF Research Database (Denmark)

Boennelycke, M; Gräs, Søren; Lose, G

2013-01-01

Cell-based tissue engineering strategies could potentially provide attractive alternatives to surgical reconstruction of native tissue or the use of surgical implants in treating pelvic organ prolapse (POP).......Cell-based tissue engineering strategies could potentially provide attractive alternatives to surgical reconstruction of native tissue or the use of surgical implants in treating pelvic organ prolapse (POP)....

Treating high-mercury-containing lamps using full-scale thermal desorption technology.

Science.gov (United States)

Chang, T C; You, S J; Yu, B S; Chen, C M; Chiu, Y C

2009-03-15

The mercury content in high-mercury-containing lamps are always between 400 mg/kg and 200,000 mg/kg. This concentration is much higher than the 260 mg/kg lower boundary recommended for the thermal desorption process suggested by the US Resource Conservation and Recovery Act. According to a Taiwan EPA survey, about 4,833,000 cold cathode fluorescent lamps (CCFLs), 486,000 ultraviolet lamps and 25,000 super high pressure mercury lamps (SHPs) have been disposed of in the industrial waste treatment system, producing 80, 92 and 9 kg-mercury/year through domestic treatment, offshore treatment and air emissions, respectively. To deal with this problem we set up a full-scale thermal desorption process to treat and recover the mercury from SHPs, fluorescent tube tailpipes, fluorescent tubes containing mercury-fluorescent powder, and CCFLs containing mercury-fluorescent powder and monitor the use of different pre-heating temperatures and desorption times. The experimental results reveal that the average thermal desorption efficiency of SHPs and fluorescent tube tailpipe were both 99.95%, while the average thermal desorption efficiencies of fluorescent tubes containing mercury-fluorescent powder were between 97% and 99%. In addition, a thermal desorption efficiency of only 69.37-93.39% was obtained after treating the CCFLs containing mercury-fluorescent powder. These differences in thermal desorption efficiency might be due to the complexity of the mercury compounds contained in the lamps. In general, the thermal desorption efficiency of lamps containing mercury-complex compounds increased with higher temperatures.

Effect of supramolecular organization of a cartilaginous tissue on thermal stability of collagen II

Science.gov (United States)

Ignat'eva, N. Yu.; Averkiev, S. V.; Lunin, V. V.; Grokhovskaya, T. E.; Obrezkova, M. V.

2006-08-01

The thermal stability of collagen II in various cartilaginous tissues was studied. It was found that heating a tissue of nucleus pulposus results in collagen II melting within a temperature range of 60-70°C; an intact tissue of hyaline cartilage (of nasal septum and cartilage endplates) is a thermally stable system, where collagen II is not denatured completely up to 100°C. It was found that partial destruction of glycosaminoglycans in hyaline cartilage leads to an increase in the degree of denaturation of collagen II upon heating, although a significant fraction remains unchanged. It was shown that electrostatic interactions of proteoglycans and collagen only slightly affect the thermal stability of collagen II in the tissues. Evidently, proteoglycan aggregates play a key role: they create topological hindrances for moving polypeptide chains, thereby reducing the configurational entropy of collagen macromolecules in the state of a random coil.

Thermal characteristics of thermobrachytherapy surface applicators for treating chest wall recurrence

International Nuclear Information System (INIS)

Arunachalam, K; Maccarini, P F; Craciunescu, O I; Stauffer, P R; Schlorff, J L

2010-01-01

The aim of this study was to investigate temperature and thermal dose distributions of thermobrachytherapy surface applicators (TBSAs) developed for concurrent or sequential high dose rate (HDR) brachytherapy and microwave hyperthermia treatment of chest wall recurrence and other superficial diseases. A steady-state thermodynamics model coupled with the fluid dynamics of a water bolus and electromagnetic radiation of the hyperthermia applicator is used to characterize the temperature distributions achievable with TBSAs in an elliptical phantom model of the human torso. Power deposited by 915 MHz conformal microwave array (CMA) applicators is used to assess the specific absorption rate (SAR) distributions of rectangular (500 cm 2 ) and L-shaped (875 cm 2 ) TBSAs. The SAR distribution in tissue and fluid flow distribution inside the dual-input dual-output (DIDO) water bolus are coupled to solve the steady-state temperature and thermal dose distributions of the rectangular TBSA (R-TBSA) for superficial tumor targets extending 10-15 mm beneath the skin surface. Thermal simulations are carried out for a range of bolus inlet temperature (T b = 38-43 deg. C), water flow rate (Q b = 2-4 L min -1 ) and tumor blood perfusion (ω b = 2-5 kg m -3 s -1 ) to characterize their influence on thermal dosimetry. Steady-state SAR patterns of the R- and L-TBSA demonstrate the ability to produce conformal and localized power deposition inside the tumor target sparing surrounding normal tissues and nearby critical organs. Acceptably low variation in tissue surface cooling and surface temperature homogeneity was observed for the new DIDO bolus at a 2 L min -1 water flow rate. Temperature depth profiles and thermal dose volume histograms indicate bolus inlet temperature (T b ) to be the most influential factor on thermal dosimetry. A 42 deg. C water bolus was observed to be the optimal choice for superficial tumors extending 10-15 mm from the surface even under significant blood perfusion

Laser treatment of female stress urinary incontinence: optical, thermal, and tissue damage simulations

Science.gov (United States)

Hardy, Luke A.; Chang, Chun-Hung; Myers, Erinn M.; Kennelly, Michael J.; Fried, Nathaniel M.

2016-02-01

Treatment of female stress urinary incontinence (SUI) by laser thermal remodeling of subsurface tissues is studied. Light transport, heat transfer, and thermal damage simulations were performed for transvaginal and transurethral methods. Monte Carlo (MC) provided absorbed photon distributions in tissue layers (vaginal wall, endopelvic fascia, urethral wall). Optical properties (n,μa,μs,g) were assigned to each tissue at λ=1064 nm. A 5-mm-diameter laser beam and power of 5 W for 15 s was used, based on previous experiments. MC output was converted into absorbed energy, serving as input for ANSYS finite element heat transfer simulations of tissue temperatures over time. Convective heat transfer was simulated with contact cooling probe set at 0 °C. Thermal properties (κ,c,ρ) were assigned to each tissue layer. MATLAB code was used for Arrhenius integral thermal damage calculations. A temperature matrix was constructed from ANSYS output, and finite sum was incorporated to approximate Arrhenius integral calculations. Tissue damage properties (Ea,A) were used to compute Arrhenius sums. For the transvaginal approach, 37% of energy was absorbed in endopelvic fascia layer with 0.8% deposited beyond it. Peak temperature was 71°C, treatment zone was 0.8-mm-diameter, and almost all of 2.7-mm-thick vaginal wall was preserved. For transurethral approach, 18% energy was absorbed in endopelvic fascia with 0.3% deposited beyond it. Peak temperature was 80°C, treatment zone was 2.0-mm-diameter, and only 0.6 mm of 2.4-mm-thick urethral wall was preserved. A transvaginal approach is more feasible than transurethral approach for laser treatment of SUI.

Factors associated with collagen deposition in lymphoid tissue in long-term treated HIV-infected patients.

Science.gov (United States)

Diaz, Alba; Alós, Llúcia; León, Agathe; Mozos, Anna; Caballero, Miguel; Martinez, Antonio; Plana, Montserrat; Gallart, Teresa; Gil, Cristina; Leal, Manuel; Gatell, Jose M; García, Felipe

2010-08-24

The factors associated with fibrosis in lymphoid tissue in long-term treated HIV-infected patients and their correlation with immune reconstitution were assessed. Tonsillar biopsies were performed in seven antiretroviral-naive patients and 29 successfully treated patients (median time on treatment, 61 months). Twenty patients received protease inhibitors-sparing regimens and nine protease inhibitor-containing regimens. Five tonsillar resections of HIV-negative individuals were used as controls. Lymphoid tissue architecture, collagen deposition (fibrosis) and the mean interfollicular CD4(+) cell count per mum were assessed. Naive and long-term treated HIV-infected patients had a higher proportion of fibrosis than did HIV-uninfected persons (P lymphoid tissue (P = 0.03) and smaller increase in peripheral CD4(+) T cells (r = -0.40, P = 0.05). The factors independently associated with fibrosis in lymphoid tissue were age (P lymphoid tissue viral load when compared with patients with undetectable lymphoid tissue viral load (median 5 vs. 12%, respectively, P = 0.017) and patients receiving a protease inhibitor-sparing vs. a protease inhibitor-containing regimen (median 8 vs. 2.5%, respectively, P = 0.04). Fibrosis in lymphoid tissue was associated with a poor reconstitution of CD4(+) T cells and long-term antiretroviral therapy did not reverse this abnormality. HIV infection, older age, a detectable level of lymphoid tissue viral load in treated patients and protease inhibitor-sparing regimens seem to favour fibrosis in lymphoid tissue.

Thermal analysis of used and radiation treated polycarbonate (L-MW) biomaterial

International Nuclear Information System (INIS)

Jayabalan, M.; Sreenivasan, K.; Nair, P.D.; Jalajamani, K.V.

1988-01-01

γ-radiation treatment of radiation sterilized polycarbonate biomaterials has been carried out to ensure efficient disposal by incineration. Low molecular weight polycarbonate sterilized with 2.5 Mrad dose of γ-radiation was further treated with different doses of γ-radiation. The radiation-treated samples were subjected to thermogravimetry. The sterilized sample and the 7.5 Mrad-treated sample showed similar properties. These samples do not leave any residue during thermal decomposition. (author). 5 refs., 3 tables

Thermal interaction of short-pulsed laser focused beams with skin tissues

International Nuclear Information System (INIS)

Jiao Jian; Guo Zhixiong

2009-01-01

Time-dependent thermal interaction is developed in a skin tissue cylinder subjected to the irradiation of a train of short laser pulses. The skin embedded with a small tumor is stratified as three layers: epidermis, dermis and subcutaneous fat with different optical, thermal and physiological properties. The laser beam is focused to the tumor site by an objective lens for thermal therapy. The ultrafast radiation heat transfer of the focused beam is simulated by the transient discrete ordinates method. The transient Pennes bio-heat equation is solved numerically by the finite volume method with alternating direction implicit scheme. Emphasis is placed on the characterization of the focused beam propagation and absorption and the temperature rise in the focal spot. The effects of the focal spot size and location, the laser power, and the bio-heat equation are investigated. Comparisons with collimated irradiation are conducted. The focused beam can penetrate a greater depth and produce higher temperature rise at the target area, and thus reduce the possibility of thermal damage to the surrounding healthy tissue. It is ideal for killing cancerous cells and small tumors.

Thermal interaction of short-pulsed laser focused beams with skin tissues

Energy Technology Data Exchange (ETDEWEB)

Jiao Jian; Guo Zhixiong [Department of Mechanical and Aerospace Engineering, Rutgers, State University of New Jersey, Piscataway, NJ 08854 (United States)], E-mail: guo@jove.rutgers.edu

2009-07-07

Time-dependent thermal interaction is developed in a skin tissue cylinder subjected to the irradiation of a train of short laser pulses. The skin embedded with a small tumor is stratified as three layers: epidermis, dermis and subcutaneous fat with different optical, thermal and physiological properties. The laser beam is focused to the tumor site by an objective lens for thermal therapy. The ultrafast radiation heat transfer of the focused beam is simulated by the transient discrete ordinates method. The transient Pennes bio-heat equation is solved numerically by the finite volume method with alternating direction implicit scheme. Emphasis is placed on the characterization of the focused beam propagation and absorption and the temperature rise in the focal spot. The effects of the focal spot size and location, the laser power, and the bio-heat equation are investigated. Comparisons with collimated irradiation are conducted. The focused beam can penetrate a greater depth and produce higher temperature rise at the target area, and thus reduce the possibility of thermal damage to the surrounding healthy tissue. It is ideal for killing cancerous cells and small tumors.

The application of lesion sterilization and tissue repair 3Mix-MP for treating rat's dental pulp tissue

Directory of Open Access Journals (Sweden)

Raditya Nugroho

2015-03-01

Full Text Available Background: Lesion sterilization and tissue repair (LSTR 3Mix-MP are three broad-spectrum antibiotics, including metronidazole, ciprofloxacin and minocycline are mixed with propylene glycol or macrogol. There is the possibility ofthe healing process that marked proliferation ofnew blood vessels and proliferation offibroblasts in the treatment ofirreversible pulpitis by pulp capping LSTR 3MixMP because of  the principle of the method LSTR 3Mix-MP is to kill bacteria. Purpose: The purpose of this study to prove the effect of LSTR 3Mix-MP on chronic inflammation and the healing process in rat dental pulp tissue in vivo. Methods: Rattus norvegicus anaesthetized by using ketamine and xylazine dissolved in sterile isotonic saline solution (0.2 ml/50gr mm on the upper right thigh. Cavity preparation class I to perforation by using a low speed tapered diamond round bur. In the treatment group, rats were treated 3Mix-MP at a dose of10 mg and then covered with glass ionomer cement for 7 days on the pulp that has been opened for 3 days. The control group treated with saline irrigation on the pulp that has been opened for 3 days. Rats were killed after seven days, and then made preparations pulp tissue to count the number oflymphocytes, macrophages, plasma cells, blood vessels, and fibroblasts Results: There is an increase in the average number ofmacrophage cells, plasma, and fibroblasts; and decreased lymphocytes and blood vessels in the treated group exposure LSTR 3Mix-MP. Conclusion:LSTR 3Mix-MP can reduce chronic inflammation process and enhance the healing process in rat dental pulp tissue.

Evaluation of Perfusion and Thermal Parameters of Skin Tissue Using Cold Provocation and Thermographic Measurements

Directory of Open Access Journals (Sweden)

Strąkowska Maria

2016-09-01

Full Text Available Measurement of the perfusion coefficient and thermal parameters of skin tissue using dynamic thermography is presented in this paper. A novel approach based on cold provocation and thermal modelling of skin tissue is presented. The measurement was performed on a person’s forearm using a special cooling device equipped with the Peltier module. The proposed method first cools the skin, and then measures the changes of its temperature matching the measurement results with a heat transfer model to estimate the skin perfusion and other thermal parameters. In order to assess correctness of the proposed approach, the uncertainty analysis was performed.

Real-time deep-tissue thermal sensing with sub-degree resolution by thermally improved Nd{sup 3+}:LaF{sub 3} multifunctional nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Rocha, Uéslen, E-mail: ueslen.silva@fis.ufal.br [Fluorescence Imaging Group, Departamento de Física de Materiales C-04, Instituto Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid (Spain); Jacinto, Carlos; Kumar, Kagola Upendra [Grupo de Fotônica e Fluidos Complexos, Instituto de Física, Universidade Federal de Alagoas, 57072-970 Maceió, Alagoas (Brazil); López, Fernando J.; Bravo, David; Solé, José García [Fluorescence Imaging Group, Departamento de Física de Materiales C-04, Instituto Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid (Spain); Jaque, Daniel, E-mail: daniel.jaque@uam.es [Fluorescence Imaging Group, Departamento de Física de Materiales C-04, Instituto Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid (Spain); Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Ramon y Cajal, Madrid 28034 (Spain)

2016-07-15

Nd{sup 3+} ion doped LaF{sub 3} dielectric nanoparticles have recently emerged as very attractive multifunctional nanoparticles capable of simultaneous sub-tissue heating and thermal sensing. Although they have been already used for selective photothermal treatment of cancer tumors in animal models, their real application as self-monitored photothermal agents require further optimization and development. Dynamic adjustment of the therapy parameters is mandatory for non-selective damage minimization. It would require real-time (sub-second) thermal sensing with a sub-degree thermal resolution. In this work we demonstrate that meeting this challenge is, indeed, possible by performing controlled thermal treatment on as-synthesized Nd{sup 3+} doped LaF{sub 3} nanoparticles. Temperature induced lattice ordering and defect re-combination have been concluded to induce, simultaneously, a line fluorescence narrowing, fluorescence brightness enhancement and a remarkable increment in thermal sensitivity. Ex-vivo experiments have demonstrated that, thanks to this multi-parameter optimization, Neodymium doped LaF{sub 3} nanoparticles are capable of real time sub-tissue thermal reading with a temperature resolution as low as 0.7 °C.

A thermal monitoring sheet with low influence from adjacent waterbolus for tissue surface thermometry during clinical hyperthermia.

Science.gov (United States)

Arunachalam, Kavitha; Maccarini, Paolo F; Stauffer, Paul R

2008-10-01

This paper presents a complete thermal analysis of a novel conformal surface thermometer design with directional sensitivity for real-time temperature monitoring during hyperthermia treatments of large superficial cancer. The thermal monitoring sheet (TMS) discussed in this paper consists of a 2-D array of fiberoptic sensors embedded between two layers of flexible, low-loss, and thermally conductive printed circuit board (PCB) film. Heat transfer across all interfaces from the tissue surface through multiple layers of insulating dielectrics surrounding the small buried temperature sensor and into an adjacent temperature-regulated water coupling bolus was studied using 3-D thermal simulation software. Theoretical analyses were carried out to identify the most effective differential TMS probe configuration possible with commercially available flexible PCB materials and to compare their thermal responses with omnidirectional probes commonly used in clinical hyperthermia. A TMS sensor design that employs 0.0508-mm Kapton MTB and 0.2032-mm Kapton HN flexible polyimide films is proposed for tissue surface thermometry with low influence from the adjacent waterbolus. Comparison of the thermal simulations with clinical probes indicates the new differential TMS probe design to outperform in terms of both transient response and steady-state accuracy in selectively reading the tissue surface temperature, while decreasing the overall thermal barrier of the probe between the coupling waterbolus and tissue surface.

Characteristics of residues from thermally treated anaerobic sludges

International Nuclear Information System (INIS)

Friedman, A.A.; Smith, J.E.; De Santis, J.; Ptak, T.; Ganley, R.C.

1988-01-01

Sludge management and disposal are probably the most difficult and expensive operations involved in wastewater treatment today. To minimize final disposal costs many waste treatment facilities practice some form of anaerobic digestion and dewatering to reduce the volume and offensiveness of their by-product sludges. One potential alternative for reducing sludge volumes consists of high temperature, partial oxidation of these previously digested sludges (PDS) and subsequent anaerobic biological conversion of resulting soluble organics to methane. This paper describes solids destruction, residue characteristics and biodegradability factors that should be considered in the design of liquid thermal treatment processes for the management of anaerobic sludges. To date only very limited information is available concerning the suitability of thermally treated PDS to serve as a substrate for the generation of methane. The primary objective of this research was to determine the feasibility of producing methane efficiently from the residual VSS in anaerobically digested sludges. Secondary goals were to establish the ''best'' conditions for thermal treatment for solubilizing PDS, to observe the effect of the soluble products on methanogenesis and to evaluate process sidestreams for dewaterability and anaerobic biodegradability

Thermally-treated Pt-coated silicon AFM tips for wear resistance in ferroelectric data storage

International Nuclear Information System (INIS)

Bhushan, Bharat; Palacio, Manuel; Kwak, Kwang Joo

2008-01-01

In ferroelectric data storage, a conductive atomic force microscopy (AFM) probe with a noble metal coating is placed in contact with a lead zirconate titanate (PZT) film. The understanding and improvement of probe tip wear, particularly at high velocities, is needed for high data rate recording. A commercial Pt-coated silicon AFM probe was thermally treated in order to form platinum silicide at the near-surface. Nanoindentation, nanoscratch and wear experiments were performed to evaluate the mechanical properties and wear performance at high velocities. The thermally treated tip exhibited lower wear than the untreated tip. The tip wear mechanism is adhesive and abrasive wear with some evidence of impact wear. The enhancement in mechanical properties and wear resistance in the thermally treated film is attributed to silicide formation in the near-surface. Auger electron spectroscopy and electrical resistivity measurements confirm the formation of platinum silicide. This study advances the understanding of thin film nanoscale surface interactions

Thermally treated grass fibers as colonizable substrate for beneficial bacterial inoculum

NARCIS (Netherlands)

Trifonova, R.D.; Postma, J.; Ketelaars, J.J.M.H.; Elsas, van J.D.

2008-01-01

This study investigates how thermally treated (i.e., torrefied) grass, a new prospective ingredient of potting soils, is colonized by microorganisms. Torrefied grass fibers (TGF) represent a specific colonizable niche, which is potentially useful to establish a beneficial microbial community that

Parametric Thermal Models of the Transient Reactor Test Facility (TREAT)

Energy Technology Data Exchange (ETDEWEB)

Bradley K. Heath

2014-03-01

This work supports the restart of transient testing in the United States using the Department of Energy’s Transient Reactor Test Facility at the Idaho National Laboratory. It also supports the Global Threat Reduction Initiative by reducing proliferation risk of high enriched uranium fuel. The work involves the creation of a nuclear fuel assembly model using the fuel performance code known as BISON. The model simulates the thermal behavior of a nuclear fuel assembly during steady state and transient operational modes. Additional models of the same geometry but differing material properties are created to perform parametric studies. The results show that fuel and cladding thermal conductivity have the greatest effect on fuel temperature under the steady state operational mode. Fuel density and fuel specific heat have the greatest effect for transient operational model. When considering a new fuel type it is recommended to use materials that decrease the specific heat of the fuel and the thermal conductivity of the fuel’s cladding in order to deal with higher density fuels that accompany the LEU conversion process. Data on the latest operating conditions of TREAT need to be attained in order to validate BISON’s results. BISON’s models for TREAT (material models, boundary convection models) are modest and need additional work to ensure accuracy and confidence in results.

Technological and Thermal Properties of Thermoplastic Composites Filled with Heat-treated Alder Wood

Directory of Open Access Journals (Sweden)

Mürşit Tufan

2016-02-01

Full Text Available This study investigated the effect of heat-treated wood content on the water absorption, mechanical, and thermal properties of wood plastic composites (WPCs. The WPCs were produced from various loadings (30, 40, and 50 wt% of heat-treated and untreated alder wood flours (Alnus glutinosa L. using high-density polyethylene (HDPE with 3 wt% maleated polyethylene (MAPE coupling agent. All WPC formulations were compression molded into a hot press for 3 min at 170 ºC. The WPCs were evaluated using mechanical testing, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, and differential scanning calorimetry (DSC. The mechanical property values of the WPC specimens decreased with increasing amounts of the heat-treated wood flour, except for the tensile modulus values. The heat treatment of alder wood slightly increased the thermal stability of the WPCs compared with the reference WPCs. The crystallization degree (Xc and the enthalpy of crystallization of the WPCs slightly decreased with increasing content of the heat-treated wood flour. However, all WPCs containing the heat-treated alder wood flour showed a higher crystallinity degree than that of the virgin HDPE.

Use of residual hydrocarbons treated by Thermal Plasma (recovery of energy by-products)

International Nuclear Information System (INIS)

Carreno B, J.A.; Pacheco S, J.O.; Ramos F, F.; Cruz A, A.; Duran G, M.

2001-01-01

The emergence of new technologies is getting greater importance for the control of pollution. One of them is the destruction of hazardous wastes treated by thermal plasma, which is of special interest for the efficient treatment of the hazardous wastes since the heat generated by thermal plasma is able to destroy the molecular bonds generating solids and gaseous products which do not represent danger for the human being and the environment. The thermal plasma is the suitable technology for treating a wide range of hazardous wastes, including the residual hydrocarbons from the refinement process of petroleum, plasma exceeds the barrier of 3000 Centigrade. The efficiency of the degradation of residues is greater than 99.99%. Toxic emissions are not generated to environment as SO 2 , NO x and CO 2 neither dioxins and furans by being a pyrolysis process. The use of hydrogen as fuel does not generate pollution to environment. (Author)

Effects of microwave heating on the thermal states of biological tissues

African Journals Online (AJOL)

Effects of microwave heating on the thermal states of biological tissues. Nabil TM El-dabe, Mona AA Mohamed, Asma F El-Sayed. Abstract. A mathematical analysis of microwave heating equations in one-dimensional multi-layer model has been discussed. Maxwell's equations and transient bioheat transfer equation were ...

Effect of mechanical tissue properties on thermal damage in skin after IR-laser ablation

Energy Technology Data Exchange (ETDEWEB)

Frenz, M.; Romano, V.; Forrer, M.; Weber, H.P. (Inst. of Applied Physics, Bern Univ. (Switzerland)); Mischler, C.; Mueller, O.M. (Anatomical Inst., Bern Univ. (Switzerland))

1991-04-01

The damage created instantaneously in dorsal skin and in the subjacent skeletal muscle layer after CO{sub 2} and Er{sup 3+} laser incisions is histologically and ultrastructurally investigated. Light microscopical examinations show an up to three times larger damage zone in the subcutaneous layer of skeletal muscle than in the connective tissue above. The extent of thermally altered muscle tissue is classified by different zones and characterized by comparison to long time heating injuries. The unexpectedly large damage is a result of the change of elastic properties occurring abruptly at the transition between different materials. This leads to a discontinuity of the cutting dynamics that reduces the ejection of tissue material. We show that the degree of thermal damage originates from the amount of hot material that is not ejected out of the crater acting as a secondary heat source. (orig.).

A heterogeneous human tissue mimicking phantom for RF heating and MRI thermal monitoring verification.

Science.gov (United States)

Yuan, Yu; Wyatt, Cory; Maccarini, Paolo; Stauffer, Paul; Craciunescu, Oana; Macfall, James; Dewhirst, Mark; Das, Shiva K

2012-04-07

This paper describes a heterogeneous phantom that mimics a human thigh with a deep-seated tumor, for the purpose of studying the performance of radiofrequency (RF) heating equipment and non-invasive temperature monitoring with magnetic resonance imaging (MRI). The heterogeneous cylindrical phantom was constructed with an outer fat layer surrounding an inner core of phantom material mimicking muscle, tumor and marrow-filled bone. The component materials were formulated to have dielectric and thermal properties similar to human tissues. The dielectric properties of the tissue mimicking phantom materials were measured with a microwave vector network analyzer and impedance probe over the frequency range of 80-500 MHz and at temperatures of 24, 37 and 45 °C. The specific heat values of the component materials were measured using a differential scanning calorimeter over the temperature range of 15-55 °C. The thermal conductivity value was obtained from fitting the curves obtained from one-dimensional heat transfer measurement. The phantom was used to verify the operation of a cylindrical four-antenna annular phased array extremity applicator (140 MHz) by examining the proton resonance frequency shift (PRFS) thermal imaging patterns for various magnitude/phase settings (including settings to focus heating in tumors). For muscle and tumor materials, MRI was also used to measure T1/T2* values (1.5 T) and to obtain the slope of the PRFS phase change versus temperature change curve. The dielectric and thermal properties of the phantom materials were in close agreement to well-accepted published results for human tissues. The phantom was able to successfully demonstrate satisfactory operation of the tested heating equipment. The MRI-measured thermal distributions matched the expected patterns for various magnitude/phase settings of the applicator, allowing the phantom to be used as a quality assurance tool. Importantly, the material formulations for the various tissue types

Cytocompatibility of Plasma and Thermally Treated Biopolymers

Directory of Open Access Journals (Sweden)

Petr Slepička

2013-01-01

Full Text Available This paper is focused on the surface characterization of plasma and consequently thermally treated biocompatible polymers. PLLA (poly(L-lactide acid and PMP (poly-4-methyl-1-pentene are studied. The influence of Ar plasma treatment on the surface polarity of substrate measured immediately after treatment and during the polymer surface aging is studied. Surface roughness, morphology, wettability, and surface chemistry were determined. Plasma treatment leads to significant changes in PLLA surface morphology and chemistry, with the PMP being slightly affected. The higher resistance to plasma fluence results in smaller ablation of PMP than that of PLLA. The plasma treatment improves cell adhesion and proliferation on the PMP. Plasma treatment of PLLA influences mostly the homogeneity of adhered and proliferated VSMC.

Thermal Skin Damage During Reirradiation and Hyperthermia Is Time-Temperature Dependent

Energy Technology Data Exchange (ETDEWEB)

Bakker, Akke, E-mail: akke.bakker@amc.uva.nl [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands); Kolff, M. Willemijn [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands); Holman, Rebecca [Clinical Research Unit, Academic Medical Center (AMC), Amsterdam (Netherlands); Leeuwen, Caspar M. van; Korshuize-van Straten, Linda; Kroon-Oldenhof, Rianne de; Rasch, Coen R.N.; Tienhoven, Geertjan van; Crezee, Hans [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands)

2017-06-01

Purpose: To investigate the relationship of thermal skin damage (TSD) to time–temperature isoeffect levels for patients with breast cancer recurrence treated with reirradiation plus hyperthermia (reRT + HT), and to investigate whether the treatment history of previous treatments (scar tissue) is a risk factor for TSD. Methods and Materials: In this observational study, temperature characteristics of hyperthermia sessions were analyzed in 262 patients with recurrent breast cancer treated in the AMC between 2010 and 2014 with reirradiation and weekly hyperthermia for 1 hour. Skin temperature was measured using a median of 42 (range, 29-82) measurement points per hyperthermia session. Results: Sixty-eight patients (26%) developed 79 sites of TSD, after the first (n=26), second (n=17), third (n=27), and fourth (n=9) hyperthermia session. Seventy percent of TSD occurred on or near scar tissue. Scar tissue reached higher temperatures than other skin tissue (0.4°C, P<.001). A total of 102 measurement points corresponded to actual TSD sites in 35 of 79 sessions in which TSD developed. Thermal skin damage sites had much higher maximum temperatures than non-TSD sites (2.8°C, P<.001). Generalized linear mixed models showed that the probability of TSD is related to temperature and thermal dose values (P<.001) and that scar tissue is more at risk (odds ratio 0.4, P<.001). Limiting the maximum temperature of a measurement point to 43.7°C would mean that the probability of observing TSD was at most 5%. Conclusion: Thermal skin damage during reRT + HT for recurrent breast cancer was related to higher local temperatures and time–temperature isoeffect levels. Scar tissue reached higher temperatures than other skin tissue, and TSD occurred at lower temperatures and thermal dose values in scar tissue compared with other skin tissue. Indeed, TSD developed often on and around scar tissue from previous surgical procedures.

Can Rotational Atherectomy Cause Thermal Tissue Damage? A Study of the Potential Heating and Thermal Tissue Effects of a Rotational Atherectomy Device

International Nuclear Information System (INIS)

Gehani, Abdurrazzak A.; Rees, Michael R.

1998-01-01

Purpose: Thermal tissue damage (TTD) is customarily associated with some lasers. The thermal potential of rotational atherectomy (RA) devices is unknown. We investigated the temperature profile and potential TTD as well as the value of fluid flushing of an RA device. Methods: We used a high-resolution infrared imaging system that can detect changes as small as 0.1 deg. C to measure the temperature changes at the tip of a fast RA device with and without fluid flushing. To assess TTD, segments of porcine aorta were subjected to the rotating tip under controlled conditions, stained by a special histochemical stain (picrisirius red) and examined under normal and polarized light microscopy. Results: There was significant heating of the rotating cam. The mean 'peak' temperature rise was 52.8 ± 16.9 deg. C. This was related to rotational speed; thus the 'peak' temperature rise was 88.3 ± 12.6 deg. C at 80,000 rpm and 17.3 ± 3.8 deg. C at 20,000 rpm (p < 0.001, t-test). Fluid flushing at 18 ml/min reduced, but did not abolish, heating of the device (11.8 ± 2.9 deg. C). A crater was observed in all segments exposed to the rotating tip. The following features were most notable: (i) A zone of 'thermal' tissue damage extended radially from the crater reaching adventitia in some sections, especially at high speeds. This zone showed markedly reduced or absent birefringence. (ii) Fluid flushing of the catheter reduced the above changes but increased the incidence and extent of dissections in the media, especially when combined with high atherectomy speeds. (iii) These changes were observed in five of six specimens exposed to RA without flushing, but in only one of six with flushing (p < 0.05). (iv) None of the above changes was seen in control segments. Conclusion: RA is capable of generating significant heat and potential TTD. Fluid flushing reduced heating and TTD. These findings warrant further studies in vivo, and may influence the design of atherectomy devices

Thermal contribution of compact bone to intervening tissue-like media exposed to planar ultrasound

Energy Technology Data Exchange (ETDEWEB)

Moros, Eduardo G [Department of Radiation Oncology, Washington University, St Louis, MO 63108 (United States); Novak, Petr [Department of Radiation Oncology, Washington University, St Louis, MO 63108 (United States); Straube, William L [Department of Radiation Oncology, Washington University, St Louis, MO 63108 (United States); Kolluri, Prashant [Department of Radiation Oncology, Washington University, St Louis, MO 63108 (United States); Yablonskiy, Dmitriy A [Department of Radiology, Washington University, St Louis, MO 63108 (United States); Myerson, Robert J [Department of Radiation Oncology, Washington University, St Louis, MO 63108 (United States)

2004-03-21

The presence of bone in the ultrasound beam path raises concerns, both in diagnostic and therapeutic applications, because significant temperature elevations may be induced at nearby soft tissue-bone interfaces due the facts that ultrasound is (i) highly absorbed in bone and (ii) reflected at soft tissue-bone interfaces in various degrees depending on angle of incidence. Consequently, in ultrasonic thermal therapy, the presence of bone in the ultrasound beam path is considered a major disadvantage and it is usually avoided. However, based on clinical experience and previous theoretical studies, we hypothesized that the presence of bone in superficial unfocused ultrasound hyperthermia can actually be exploited to induce more uniform and enhanced (with respect to the no-bone situation) temperature distributions in superficial target volumes. In particular, we hypothesize that the presence of underlying bone in superficial target volume enhances temperature elevation not only by additional direct power deposition from acoustic reflection, but also from thermal diffusion from the underlying bone. Here we report laboratory results that corroborate previous computational studies and strengthen the above-stated hypothesis. Three different temperature measurement techniques, namely, thermometric (using fibre-optic temperature probes), thermographic (using an infrared camera) and magnetic resonance imaging (using proton resonance frequency shifts), were used in high-power short-exposure, and in low-power extended-exposure, experiments using a 19 mm diameter planar transducer operating at 1.0 and 3.3 MHz (frequencies of clinical relevance). The measurements were performed on three technique-specific phantoms (with and without bone inclusions) and experimental set-ups that resembled possible superficial ultrasound hyperthermia clinical situations. Results from all three techniques were in general agreement and clearly showed that significantly higher heating rates (greater

Thermal distribution in biological tissue at laser induced fluorescence and photodynamic therapy

Science.gov (United States)

Krasnikov, I. V.; Seteikin, A. Yu.; Drakaki, E.; Makropoulou, M.

2012-03-01

Laser induced fluorescence spectroscopy and photodynamic therapy (PDT) are techniques currently introduced in clinical applications for visualization and local destruction of malignant tumours as well as premalignant lesions. During the laser irradiation of tissues for the diagnostic and therapeutic purposes, the absorbed optical energy generates heat, although the power density of the treatment light for surface illumination is normally low enough not to cause any significantly increased tissue temperature. In this work we tried to evaluate the utility of Monte Carlo modeling for simulating the temperature fields and the dynamics of heat conduction into the skin tissue under several laser irradiation conditions with both a pulsed UV laser and a continuous wave visible laser beam. The analysis of the results showed that heat is not localized on the surface, but it is collected inside the tissue. By varying the boundary conditions on the surface and the type of the laser radiation (continuous or pulsed) we can reach higher than normal temperature inside the tissue without simultaneous formation of thermally damaged tissue (e.g. coagulation or necrosis zone).

Amide proton transfer imaging of high intensity focused ultrasound-treated tumor tissue

NARCIS (Netherlands)

Hectors, S.J.C.G.; Jacobs, I.; Strijkers, G.J.; Nicolay, K.

2014-01-01

Purpose: In this study, the suitability of amide proton transfer (APT) imaging as a biomarker for the characterization of high intensity focused ultrasound (HIFU)-treated tumor tissue was assessed. Methods: APT imaging was performed on tumor-bearing mice before (n=15), directly after (n=15) and at 3

Amide Proton Transfer Imaging of High Intensity Focused Ultrasound-Treated Tumor Tissue

NARCIS (Netherlands)

Hectors, Stefanie J. C. G.; Jacobs, Igor; Strijkers, Gustav J.; Nicolay, Klaas

2014-01-01

PurposeIn this study, the suitability of amide proton transfer (APT) imaging as a biomarker for the characterization of high intensity focused ultrasound (HIFU)-treated tumor tissue was assessed. MethodsAPT imaging was performed on tumor-bearing mice before (n=15), directly after (n=15) and at 3

Effect of reactor radiation on the thermal conductivity of TREAT fuel

Energy Technology Data Exchange (ETDEWEB)

Mo, Kun, E-mail: kunmo@anl.gov; Miao, Yinbin; Kontogeorgakos, Dimitrios C.; Connaway, Heather M.; Wright, Arthur E.; Yacout, Abdellatif M.

2017-04-15

The Transient Reactor Test Facility (TREAT) at the Idaho National Laboratory is resuming operations after more than 20 years in latency in order to produce high-neutron-flux transients for investigating transient-induced behavior of reactor fuels and their interactions with other materials and structures. A parallel program is ongoing to develop a replacement core in which the fuel, historically containing highly-enriched uranium (HEU), is replaced by low-enriched uranium (LEU). Both the HEU and prospective LEU fuels are in the form of UO{sub 2} particles dispersed in a graphite matrix, but the LEU fuel will contain a much higher volume of UO{sub 2} particles, which may create a larger area of interphase boundaries between the particles and the graphite. This may lead to a higher volume fraction of graphite exposed to the fission fragments escaping from the UO{sub 2} particles, and thus may induce a higher volume of fission-fragment damage on the fuel graphite. In this work, we analyzed the reactor-radiation induced thermal conductivity degradation of graphite-based dispersion fuel. A semi-empirical method to model the relative thermal conductivity with reactor radiation was proposed and validated based on the available experimental data. Prediction of thermal conductivity degradation of LEU TREAT fuel during a long-term operation was performed, with a focus on the effect of UO{sub 2} particle size on fission-fragment damage. The proposed method can be further adjusted to evaluate the degradation of other properties of graphite-based dispersion fuel.

Effect of acid treated carbon nanotubes on mechanical, rheological and thermal properties of polystyrene nanocomposites

KAUST Repository

Amr, Issam Thaher

2011-09-01

In this work, multiwall carbon nanotubes (CNT) were functionalized by acid treatment and characterized using Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). Polystyrene/CNT composites of both the untreated and acid treated carbon nanotubes were prepared by thermal bulk polymerization without any initiator at different loadings of CNT. The tensile tests showed that the addition of 0.5 wt.% of acid treated CNT results in 22% increase in Young\\'s modulus. The DSC measurements showed a decrease in glass transition temperature (Tg) of PS in the composites. The rheological studies at 190 °C showed that the addition of untreated CNT increases the viscoelastic behavior of the PS matrix, while the acid treated CNT acts as plasticizer. Thermogravimetric analysis indicated that the incorporation of CNT into PS enhanced the thermal properties of the matrix polymer. © 2011 Elsevier Ltd. All rights reserved.

Burn Depth Estimation Based on Infrared Imaging of Thermally Excited Tissue

Energy Technology Data Exchange (ETDEWEB)

Dickey, F.M.; Hoswade, S.C.; Yee, M.L.

1999-03-05

Accurate estimation of the depth of partial-thickness burns and the early prediction of a need for surgical intervention are difficult. A non-invasive technique utilizing the difference in thermal relaxation time between burned and normal skin may be useful in this regard. In practice, a thermal camera would record the skin's response to heating or cooling by a small amount-roughly 5 C for a short duration. The thermal stimulus would be provided by a heat lamp, hot or cold air, or other means. Processing of the thermal transients would reveal areas that returned to equilibrium at different rates, which should correspond to different burn depths. In deeper thickness burns, the outside layer of skin is further removed from the constant-temperature region maintained through blood flow. Deeper thickness areas should thus return to equilibrium more slowly than other areas. Since the technique only records changes in the skin's temperature, it is not sensitive to room temperature, the burn's location, or the state of the patient. Preliminary results are presented for analysis of a simulated burn, formed by applying a patch of biosynthetic wound dressing on top of normal skin tissue.

The Edinburgh experience of treating sarcomas of soft tissues and bone with neutron irradiation

International Nuclear Information System (INIS)

Duncan, W.; Arnott, S.J.; Jack, W.J.L.

1986-01-01

The experience of treating 30 patients with sarcomas of soft tissue and bone with d(15)+Be neutron irradiation is reported. The local control of measurable soft-tissue sarcomas was 38.5% (minimum follow-up 2 years), which is similar to that expected after photon therapy. The radiation morbidity was unacceptably high (50%). Bone tumours did not respond well; in only one out of nine was lasting local tumour control achieved. (author)

The link between tissue elasticity and thermal dose in vivo

International Nuclear Information System (INIS)

Sapin-de Brosses, Emilie; Pernot, Mathieu; Tanter, Mickaël

2011-01-01

The objective of this study was to investigate in vivo the relationship between stiffness and thermal dose. For this purpose, shear wave elastography (SWE)—a novel ultrasound-based technique for real-time mapping of the stiffness of biological soft tissues—is performed in temperature-controlled experiments. Experiments were conducted on nine anesthetized rats. Their right leg was put in a thermo-regulated waterbath. The right leg of each animal was heated at one particular temperature between 38 °C and 48.5 °C for 15 min to 3 h. Shear waves were generated in the muscle using the acoustic radiation force induced by a linear ultrasonic probe. The shear wave propagation was imaged in real time by the probe using an ultrafast scanner prototype (10 000 frames s −1 ). The local tissue stiffness was derived from the shear wave speed. Two optical fiber sensors were inserted into the muscle to measure in situ the temperature. Stiffness was found to increase strongly during the experiments. When expressed as a function of the thermal dose, the stiffness curves were found to be the same for all experiments. A thermal dose threshold was found at 202 min for an eightfold stiffness increase. Finally, the time–temperature relationship was established for different stiffness ratios. The slope of the time–temperature relationship based on stiffness measurements was found identical to the one obtained for cell death in the seminal paper on the thermal dose by Sapareto and Dewey in 1984 (Int. J. Radiat. Oncol. Biol. Phys. 10 787–800). The present results highlight the stiffness increase as a good indicator of thermal necrosis. SWE imaging can be used in vivo for necrosis threshold determination in thermal therapy.

Pixe analysis of trace elements in tissues of rats treated with anticonvulsants

Science.gov (United States)

Hurd, R. W.; Van Rinsvelt, H. A.; Kinyua, A. M.; O'Neill, M. P.; Wilder, B. J.; Houdayer, A.; Hinrichsen, P. F.

1987-04-01

Several lines of evidence implicate metals in epilepsy. Anticonvulsant drugs are noted to alter levels of metals in humans and animals. PIXE analysis was used to investigate effects of three anticonvulsant drugs on tissue and brain cortex trace elements. The content of zinc and copper was increased in liver and spleen of rats treated with anticonvulsants while selenium was decreased in cortex.

PIXE analysis of trace elements in tissues of rats treated with anticonvulsants

Energy Technology Data Exchange (ETDEWEB)

Hurd, R.W.; Van Rinsvelt, H.A.; Kinyua, A.M.; O' Neill, M.P.; Wilder, B.J.; Houdayer, A.; Hinrichsen, P.F.

1987-04-01

Several lines of evidence implicate metals in epilepsy. Anticonvulsant drugs are noted to alter levels of metals in humans and animals. PIXE analysis was used to investigate effects of three anticonvulsant drugs on tissue and brain cortex trace elements. The content of zinc and copper was increased in liver and spleen of rats treated with anticonvulsants while selenium was decreased in cortex.

PIXE analysis of trace elements in tissues of rats treated with anticonvulsants

International Nuclear Information System (INIS)

Hurd, R.W.; Van Rinsvelt, H.A.; Kinyua, A.M.; O'Neill, M.P.; Wilder, B.J.; Florida Univ., Gainesville; Houdayer, A.; Hinrichsen, P.F.

1987-01-01

Several lines of evidence implicate metals in epilepsy. Anticonvulsant drugs are noted to alter levels of metals in humans and animals. PIXE analysis was used to investigate effects of three anticonvulsant drugs on tissue and brain cortex trace elements. The content of zinc and copper was increased in liver and spleen of rats treated with anticonvulsants while selenium was decreased in cortex. (orig.)

Nutrients and heavy metal distribution in thermally treated pig manure

DEFF Research Database (Denmark)

Kuligowski, Ksawery; Poulsen, Tjalfe G.; Stoholm, Peder

2008-01-01

Ash from pig manure treated by combustion and thermal gasification was characterized and compared in terms of nutrient, i.e., potassium (K), phosphorus (P) and heavy metal, i.e., cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) contents. Total nutrient and metal concentrations...... that ash from gasified manure contained more water-extractable K in comparison with combusted manure whereas the opposite was the case with respect to P. Heavy metals Ni, Cr and Cd were present in higher concentrations in the fine particle size fractions (

Experimental evaluation of the thermal properties of two tissue equivalent phantom materials.

Science.gov (United States)

Craciunescu, O I; Howle, L E; Clegg, S T

1999-01-01

Tissue equivalent radio frequency (RF) phantoms provide a means for measuring the power deposition of various hyperthermia therapy applicators. Temperature measurements made in phantoms are used to verify the accuracy of various numerical approaches for computing the power and/or temperature distributions. For the numerical simulations to be accurate, the electrical and thermal properties of the materials that form the phantom should be accurately characterized. This paper reports on the experimentally measured thermal properties of two commonly used phantom materials, i.e. a rigid material with the electrical properties of human fat, and a low concentration polymer gel with the electrical properties of human muscle. Particularities of the two samples required the design of alternative measuring techniques for the specific heat and thermal conductivity. For the specific heat, a calorimeter method is used. For the thermal diffusivity, a method derived from the standard guarded comparative-longitudinal heat flow technique was used for both materials. For the 'muscle'-like material, the thermal conductivity, density and specific heat at constant pressure were measured as: k = 0.31 +/- 0.001 W(mK)(-1), p = 1026 +/- 7 kgm(-3), and c(p) = 4584 +/- 107 J(kgK)(-1). For the 'fat'-like material, the literature reports on the density and specific heat such that only the thermal conductivity was measured as k = 0.55 W(mK)(-1).

Polarized neutron reflectivity study of a thermally treated MnIr/CoFe exchange bias system.

Science.gov (United States)

Awaji, Naoki; Miyajima, Toyoo; Doi, Shuuichi; Nomura, Kenji

2010-12-01

It has recently been found that the exchange bias of a MnIr/CoFe system can be increased significantly by adding a thermal treatment to the bilayer. To reveal the origin of the higher exchange bias, we performed polarized neutron reflectivity measurements at the JRR-3 neutron source. The magnetization vector near the MnIr/CoFe interface for thermally treated samples differed from that for samples without the treatment. We propose a model in which the pinned spin area at the interface is extended due to the increased roughness and atomic interdiffusion that result from the thermal treatment.

Prevalence of oral soft tissue lesions in HIV-infected minority children treated with highly active antiretroviral therapies.

Science.gov (United States)

Flanagan, M A; Barasch, A; Koenigsberg, S R; Fine, D; Houpt, M

2000-01-01

This project studied the prevalence of oral soft tissue disease in HIV-infected children treated with highly active antiretroviral therapy (HAART). Thirty-eight HIV-infected children participated in the study. Twenty-three of these patients were treated with HAART while 14 received exclusively reverse transcriptase inhibitors (RTI) and served as controls. The children were examined three times at approximately one-month intervals while their health history and laboratory data were abstracted from medical charts. Analyses were performed to determine differences in lesion prevalence between treatment groups as well as between lesion and no lesion groups with regard to immune differences. Thirty patients (79%) had oral lesions detected in at least one visit. There were no differences in specific lesion prevalence between HAART compared with RTI-treated children. However, a trend for more oral candidiasis in the latter group was observed. Subjects with oral soft tissue lesions had lower CD4 counts (P = 0.04) and percentage (P = 0.01) but similar viral loads when compared to patients without oral soft tissue disease. HAART does not appear to significantly affect oral soft tissue disease prevalence in HIV-infected children. Presence of lesions was associated with decreased immunity and may signal advancing disease.

Head and neck soft tissue sarcomas treated with radiation therapy

Directory of Open Access Journals (Sweden)

Lucas K. Vitzthum

2016-06-01

Full Text Available Head and neck soft tissue sarcomas (HNSTSs are rare and heterogeneous cancers in which radiation therapy (RT has an important role in local tumor control (LC. The purpose of this study was to evaluate outcomes and patterns of treatment failure in patients with HNSTS treated with RT. A retrospective review was performed of adult patients with HNSTS treated with RT from January 1, 1998, to December 31, 2012. LC, locoregional control (LRC, disease-free survival (DFS, overall survival (OS, and predictors thereof were assessed. Forty-eight patients with HNSTS were evaluated. Five-year Kaplan-Meier estimates of LC, LRC, DFS, and OS were 87, 73, 63, and 83%, respectively. Angiosarcomas were found to be associated with worse LC, LRC, DFS, and OS. Patients over the age of 60 had lower rates of DFS. HNSTSs comprise a diverse group of tumors that can be managed with various treatment regimens involving RT. Angiosarcomas have higher recurrence and mortality rates.

Thermal gelation and tissue adhesion of biomimetic hydrogels

International Nuclear Information System (INIS)

Burke, Sean A; Ritter-Jones, Marsha; Lee, Bruce P; Messersmith, Phillip B

2007-01-01

Marine and freshwater mussels are notorious foulers of natural and manmade surfaces, secreting specialized protein adhesives for rapid and durable attachment to wet substrates. Given the strong and water-resistant nature of mussel adhesive proteins, significant potential exists for mimicking their adhesive characteristics in bioinspired synthetic polymer materials. An important component of these proteins is L-3,4-dihydroxylphenylalanine (DOPA), an amino acid believed to contribute to mussel glue solidification through oxidation and crosslinking reactions. Synthetic polymers containing DOPA residues have previously been shown to crosslink into hydrogels upon the introduction of oxidizing reagents. Here we introduce a strategy for stimuli responsive gel formation of mussel adhesive protein mimetic polymers. Lipid vesicles with a bilayer melting transition of 37 0 C were designed from a mixture of dipalmitoyl and dimyristoyl phosphatidylcholines and exploited for the release of a sequestered oxidizing reagent upon heating from ambient to physiologic temperature. Colorimetric studies indicated that sodium-periodate-loaded liposomes released their cargo at the phase transition temperature, and when used in conjunction with a DOPA-functionalized poly(ethylene glycol) polymer gave rise to rapid solidification of a crosslinked polymer hydrogel. The tissue adhesive properties of this biomimetic system were determined by in situ thermal gelation of liposome/polymer hydrogel between two porcine dermal tissue surfaces. Bond strength measurements showed that the bond formed by the adhesive hydrogel (mean = 35.1 kPa, SD = 12.5 kPa, n = 11) was several times stronger than a fibrin glue control tested under the same conditions. The results suggest a possible use of this biomimetic strategy for repair of soft tissues

Effect of Electrothermal Treatment on Nerve Tissue Within the Triangular Fibrocartilage Complex, Scapholunate, and Lunotriquetral Interosseous Ligaments.

Science.gov (United States)

Pirolo, Joseph M; Le, Wei; Yao, Jeffrey

2016-05-01

To evaluate the effect of thermal treatment on neural tissue in the triangular fibrocartilage complex (TFCC), scapholunate interosseous ligament (SLIL), and lunotriquetral interosseous ligament (LTIL). The intact TFCC, SLIL, and LTIL were harvested from cadaveric specimens and treated with a radiofrequency probe as would be performed intraoperatively. Slides were stained using a triple-stain technique for neurotrophin receptor p75, pan-neuronal marker protein gene product 9.5 (PGP 9.5), and 4',6-diamidino-2-phenylindole for neural identification. Five TFCC, 5 SLIL, and 4 LTIL specimens were imaged with fluorescence microscopy. Imaging software was used to measure fluorescence signals and compare thermally treated areas with adjacent untreated areas. A paired t test was used to compare treated versus untreated areas. P < .05 was considered significant. For the TFCC, a mean of 94.9% ± 2.7% of PGP 9.5-positive neural tissue was ablated within a mean area of 11.7 ± 2.5 mm(2) (P = .02). For the SLIL treated from the radiocarpal surface, 97.4% ± 1.0% was ablated to a mean depth of 2.4 ± 0.3 mm from the surface and a mean horizontal spread of 3.4 ± 0.5 mm (P = .01). For the LTIL, 96.0% ± 1.5% was ablated to a mean depth of 1.7 ± 0.7 mm and a mean horizontal spread of 2.6 ± 1.0 mm (P = .02). Differences in the presence of neural tissue between treated areas and adjacent untreated areas were statistically significant for all specimens. Our study confirms elimination of neuronal markers after thermal treatment of the TFCC, SLIL, and LTIL in cadaveric specimens. This effect penetrates below the surface to innervated collagen tissue that is left structurally intact after treatment. Electrothermal treatment as commonly performed to treat symptomatic SLIL, LTIL, and TFCC tears eliminates neuronal tissue in treated areas and may function to relieve pain through a denervation effect. Copyright © 2016 Arthroscopy Association of North America. Published by

The impact of thermal wave characteristics on thermal dose distribution during thermal therapy: A numerical study

International Nuclear Information System (INIS)

Shih, T.-C.; Kou, H.-S.; Liauh, C.-T.; Lin, W.-L.

2005-01-01

The aim of this study was to investigate the effects of the propagation speed of a thermal wave in terms of the thermal relaxation time on the temperature/thermal dose distributions in living tissue during thermal therapies. The temperature field in tissue was solved by the finite difference method, and the thermal dose was calculated from the formulation proposed by Sapareto and Dewey [Int. J. Radiat. Oncol. Biol. Phys. 10, 787-800 (1984)]. Under the same total deposited energy, for a rapid heating process the time lagging behavior of the peak temperature became pronounced and the level of the peak temperature was decreased with increasing the thermal relaxation time. When the heating duration was longer than the thermal relaxation time of tissues, there was no significant difference between the thermal dose distributions with/without considering the effect of the thermal relaxation time. In other words, when the heating duration is comparable to or shorter than the thermal relaxation time of tissue, the results of the wave bioheat transfer equation (WBHTE) are fully different from that of the Pennes' bioheat transfer equation (PBHTE). Besides, for a rapid heating process the dimension of thermal lesion was still significantly affected by perfusion, because this is what is predicted by the WBHTE but not by the PBHTE, i.e., the wave feature of the temperature field cannot fully be predicted by the PBHTE

Using kinetic models to predict thermal degradation of fire-retardant-treated plywood roof sheathing

Science.gov (United States)

Patricia Lebow; Jerrold E. Winandy; Patricia K. Lebow

2003-01-01

Between 1985-1995 a substantial number of multifamily housing units in the Eastern and Southern U.S. experienced problems with thermally degraded fire-retardant-treated (FRT) plywood roof sheathing. A series of studies conducted at the USDA Forest Service, Forest Products Laboratory (FPL), examined the materials, chemical mechanisms, and process implications and has...

Development of a quantum dot mediated thermometry for minimally invasive thermal therapy

Science.gov (United States)

Hanson, Willard L.

Thermally-related, minimally invasive therapies are designed to treat tumors while minimizing damage to the surrounding tissues. Adjacent tissues become susceptible to thermal injury to ensure the cancer is completely destroyed. Destroying tumor cells, while minimizing collateral damage to the surrounding tissue, requires the capacity to control and monitor tissue temperatures both spatially and temporally. Current devices measure the tumor's tissue temperature at a specific location leaving the majority unmonitored. A point-wise application can not substantiate complete tumor destruction. This type of surgery would be more effective if volumetric tissue temperature measurement were available. On this premise, the feasibility of a quantum dot (QD) assembly to measure the tissue temperature volumetrically was tested in the experiments described in this dissertation. QDs are fluorescence semiconductor nanoparticles having various superior optical properties. This new QD-mediated thermometry is capable of monitoring the thermal features of tissues non-invasively by measuring the aggregate fluorescence intensity of the QDs accumulated at the target tissues prior to and during the surgical procedure. Thus, such a modality would allow evaluation of tissue destruction by measuring the fluorescence intensity of the QD as a function of temperature. The present study also quantified the photoluminescence intensity and attenuation of the QD as a function of depth and wavelength using a tissue phantom. A prototype system was developed to measure the illumination through a tissue phantom as a proof of concept of the feasibility of a noninvasive thermal therapy. This prototype includes experimental hardware, software and working methods to perform image acquisition, and data reduction strategic to quantify the intensity and transport characteristics of the QD. The significance of this work is that real-time volumetric temperature information will prove a more robust tool for use

Surface modification of biphasic calcium phosphate scaffolds by non-thermal atmospheric pressure nitrogen and air plasma treatment for improving osteoblast attachment and proliferation

International Nuclear Information System (INIS)

Choi, Yu-Ri; Kwon, Jae-Sung; Song, Doo-Hoon; Choi, Eun Ha; Lee, Yong-Keun; Kim, Kyoung-Nam; Kim, Kwang-Mahn

2013-01-01

Surface modifications induced by non-thermal plasma have been used extensively in biomedical applications. The attachment and proliferation of osteoblast cells are important in bone tissue engineering using scaffolds. Hence the effect of non-thermal plasma on hydroxyapatite/β-tri-calcium phosphate (HA/β-TCP) scaffolds in terms of improving osteoblast attachment and proliferation was investigated. Experimental groups were treated with non-thermal plasma for 10 min and 20 min and a control group was not treated with non-thermal plasma. For surface chemistry analysis, X-ray photoelectron spectroscopy (XPS) analysis was carried out. The hydrophilicity was determined from contact angle measurement on the surface. Atomic force microscopy analysis (AFM) was used to test the change in surface roughness and cell attachment and proliferation were evaluated using MC3T3-E1 osteoblast cells. XPS spectra revealed a decreased amount of carbon on the surface of the plasma-treated sample. The contact angle was also decreased following plasma treatment, indicating improved hydrophilicity of plasma-treated surfaces compared to the untreated disc. A significant increase in MC3T3E-1 cell attachment and proliferation was noted on plasma-treated samples as compared to untreated specimens. The results suggest that non-thermal atmospheric pressure nitrogen and air plasma treatments provide beneficial surface characteristics on HA/β-TCP scaffolds. - Highlights: ► Non-thermal plasma increased OH- and decreased C on biphasic scaffold. ► Non-thermal plasma had no effect on surface roughness. ► Non-thermal plasma resulted in hydrophilic surface. ► Non-thermal plasma resulted in better cell attachment and proliferation. ► Non-thermal plasma treatment on biphasic scaffold is useful for tissue engineering

Cancer therapy using non-thermal atmospheric pressure plasma with ultra-high electron density

International Nuclear Information System (INIS)

Tanaka, Hiromasa; Mizuno, Masaaki; Toyokuni, Shinya; Maruyama, Shoichi; Kodera, Yasuhiro; Terasaki, Hiroko; Adachi, Tetsuo; Kato, Masashi; Kikkawa, Fumitaka; Hori, Masaru

2015-01-01

Cancer therapy using non-thermal atmospheric pressure plasma is a big challenge in plasma medicine. Reactive species generated from plasma are key factors for treating cancer cells, and thus, non-thermal atmospheric pressure plasma with high electron density has been developed and applied for cancer treatment. Various cancer cell lines have been treated with plasma, and non-thermal atmospheric plasma clearly has anti-tumor effects. Recent innovative studies suggest that plasma can both directly and indirectly affect cells and tissues, and this observation has widened the range of applications. Thus, cancer therapy using non-thermal atmospheric pressure plasma is promising. Animal experiments and understanding the mode of action are essential for clinical application in the future. A new academic field that combines plasma science, the biology of free radicals, and systems biology will be established

Cancer therapy using non-thermal atmospheric pressure plasma with ultra-high electron density

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Hiromasa [Institute of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Mizuno, Masaaki [Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Toyokuni, Shinya [Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Maruyama, Shoichi [Department of Nephrology, Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Kodera, Yasuhiro [Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Terasaki, Hiroko [Department of Ophthalmology, Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Adachi, Tetsuo [Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 501-1196 Gifu (Japan); Kato, Masashi [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Kikkawa, Fumitaka [Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya 466-8550 (Japan); Hori, Masaru [Institute of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2015-12-15

Cancer therapy using non-thermal atmospheric pressure plasma is a big challenge in plasma medicine. Reactive species generated from plasma are key factors for treating cancer cells, and thus, non-thermal atmospheric pressure plasma with high electron density has been developed and applied for cancer treatment. Various cancer cell lines have been treated with plasma, and non-thermal atmospheric plasma clearly has anti-tumor effects. Recent innovative studies suggest that plasma can both directly and indirectly affect cells and tissues, and this observation has widened the range of applications. Thus, cancer therapy using non-thermal atmospheric pressure plasma is promising. Animal experiments and understanding the mode of action are essential for clinical application in the future. A new academic field that combines plasma science, the biology of free radicals, and systems biology will be established.

Impact of an angiotensin analogue in treating thermal and combined radiation injuries

Science.gov (United States)

Jadhav, Sachin Suresh

Background: In recent years there has been a growing concern regarding the use of nuclear weapons by terrorists. Such incidents in the past have shown that radiation exposure is often accompanied by other forms of trauma such as burns, wounds or infection; leading to increased mortality rates among the affected individuals. This increased risk with combined radiation injury has been attributed to the delayed wound healing observed in this injury. The Renin-Angiotensin System (RAS) has emerged as a critical regulator of wound healing. Angiotensin II (A-II) and Angiotensin (1-7) [A(1-7)] have been shown to accelerate the rate of wound healing in different animal models of cutaneous injury. Nor-Leu3-Angiotensin (1-7) [Nor-Leu3-A (1-7)], an analogue of A(1-7), is more efficient than both A-II and A(1-7) in its ability to improve wound healing and is currently in phase III clinical trials for the treatment of diabetic foot ulcers. Aims: The three main goals of this study were to; 1) Develop a combined radiation and burn injury (CRBI) model and a radiation-induced cutaneous injury model to study the pathophysiological effects of these injuries on dermal wound healing; 2) To treat thermal and CRBI injuries using Nor-Leu 3-A (1-7) and decipher the mechanism of action of this peptide and 3) Develop an in-vitro model of CRBI using dermal cells in order to study the effect of CRBI on individual cell types involved in wound healing. Results: CRBI results in delayed and exacerbated apoptosis, necrosis and inflammation in injured skin as compared to thermal injury by itself. Radiation-induced cutaneous injury shows a radiation-dose dependent increase in inflammation as well as a chronic inflammatory response in the higher radiation exposure groups. Nor-Leu3-A (1-7) can mitigate thermal and CRBI injuries by reducing inflammation, oxidative stress and DNA damage while increasing the rate of proliferation of dermal stem cells and re-epithelialization of injured skin. The in

[Gradient elevation of temperature startup experiment of thermophilic ASBR treating thermal-hydrolyzed sewage sludge].

Science.gov (United States)

Ouyang, Er-Ming; Wang, Wei; Long, Neng; Li, Huai

2009-04-15

Startup experiment was conducted for thermophilic anaerobic sequencing batch reactor (ASBR) treating thermal-hydrolyzed sewage sludge using the strategy of the step-wise temperature increment: 35 degrees C-->40 degrees C-->47 degrees C-->53 degrees C. The results showed that the first step-increase (from 35 degrees C to 40 degrees C) and final step-increase (from 47 degrees C to 53 degrees C) had only a slight effect on the digestion process. The second step-increase (from 40 degrees C to 47 degrees C) resulted in a severe disturbance: the biogas production, methane content, CODeffluent and microorganism all have strong disturbance. At the steady stage of thermophilic ASBR treating thermal-hydrolyzed sewage sludge, the average daily gas production, methane content, specific methane production (CH4/CODinfluent), TCOD removal rate and SCOD removal rate were 2.038 L/d, 72.0%, 188.8 mL/g, 63.8%, 83.3% respectively. The results of SEM and DGGE indicated that the dominant species are obviously different at early stage and steady stage.

Tissue dyslipidemia in salmonella-infected rats treated with amoxillin and pefloxacin

Directory of Open Access Journals (Sweden)

Rotimi Solomon O

2012-11-01

Full Text Available Abstract Background This study investigated the effects of salmonella infection and its chemotherapy on lipid metabolism in tissues of rats infected orally with Salmonella typhimurium and treated intraperitoneally with pefloxacin and amoxillin. Methods Animals were infected with Salmonella enterica serovar Typhimurium strain TA 98. After salmonellosis was confirmed, they were divided into 7 groups of 5 animals each. While one group served as infected control group, three groups were treated with amoxillin (7.14 mg/kg body weight, 8 hourly and the remaining three groups with pefloxacin (5.71mg/kg body weight, 12 hourly for 5 and 10 days respectively. Uninfected control animals received 0.1ml of vehicle. Rats were sacrificed 24h after 5 and 10 days of antibiotic treatment and 5 days after discontinuation of antibiotic treatment. Their corresponding controls were also sacrificed at the same time point. Blood and tissue lipids were then evaluated. Results Salmonella infection resulted in dyslipidemia characterised by increased concentrations of free fatty acids (FFA in plasma and erythrocyte, as well as enhanced cholesterogenesis, hypertriglyceridemia and phospholipidosis in plasma, low density lipoprotein-very low density lipoprotein (LDL-VLDL, erythrocytes, erythrocyte ghost and the organs. The antibiotics reversed the dyslipidemia but not totally. A significant correlation was observed between fecal bacterial load and plasma cholesterol (r=0.456, p Conclusion The findings of this study suggest that salmonella infection in rats and its therapy with pefloxacin and amoxillin perturb lipid metabolism and this perturbation is characterised by cholesterogenesis.

The mechanism of joint capsule thermal modification in an in-vitro sheep model.

Science.gov (United States)

Hayashi, K; Peters, D M; Thabit, G; Hecht, P; Vanderby, R; Fanton, G S; Markel, M D

2000-01-01

The purpose of this study was to understand the mechanism responsible for joint capsule shrinkage after nonablative laser application in an in-vitro sheep model. Femoropatellar joint capsular tissue specimens harvested from 20 adult sheep were treated with one of three power settings of a holmium:yttrium-aluminum-garnet laser or served as a control. Laser treatment significantly shortened the tissue and decreased tissue stiffness in all three laser groups, whereas failure strength was not altered significantly by laser treatment. Transmission electron microscopic examination showed swollen collagen fibrils and loss of membrane integrity of fibroblasts. A thermometric study revealed nonablative laser energy caused tissue temperature to rise in the range of 64 degrees C to 100 degrees C. Electrophoresis after trypsin digestion of the tissue revealed significant loss of distinct alpha bands of Type I collagen in laser treated samples, whereas alpha bands were present in laser treated tissue without trypsin digestion. The results of this study support the concept that the primary mechanism responsible for the effect of nonablative laser energy is thermal denaturation of collagen in joint capsular tissue associated with unwinding of the triple helical structure of the collagen molecule.

Real-time temperature feedback for nanoparticles based tumor thermal treatment (Conference Presentation)

Science.gov (United States)

Steinberg, Idan; Tamir, Gil; Gannot, Israel

2017-02-01

Systemic hyperthermia therapy exploits the fact that cancer cells are more sensitive to elevated temperatures than healthy tissue. Systemic application of hyperthermia externally usually leads to low efficiency treatment. Recently, our group and others have proposed an antibody conjugated magnetic nanoparticles (MNPs) approach to overcome the limitation of systemic hyperthermia. MNPs can bind specifically to the tumor sites, thus delivering internal highly effective targeted hyperthermia. However, such internal mechanism requires more complicated controls and monitoring. This current work presents a deep tissue temperature monitoring method to control hyperthermia effectiveness and minimize collateral damage to surrounding tissues. A low-frequency narrowband modulation of the RF field used for MNP heating leads to the generation of diffused thermal waves which propagate to the tissue surface and captured by a thermal camera. A Fourier domain, analytical heat transfer model is used for temperature monitoring algorithm. The ill-posed thermal inverse problem is solved efficiently by iterating over the source power until both the amplitude and phase match the recorded thermal image sequence. The narrow bandwidth thermal stimulation enables acquiring deep signals with high SNR. We show that thermal transverse resolution improves as the stimulation frequency increases even slightly above DC, enabling better heat source transverse separation and margin identification in the case of distributed tumors. These results can be used as a part of an overall image and treat system for efficient detection of tumors, manipulation of MNPs and monitoring MNP based hyperthermia.

Theoretical-experimental study of the non-thermal effects of the polarized laser radiation in living tissues

International Nuclear Information System (INIS)

Ribeiro, M.S.

1991-01-01

In the present research we had as a fundamental objective to analyse the non-thermal effects of the laser polarized light in biological tissues. These effects were performed with low power laser output. The theoretical procedure consisted in looking for a simple model which connects the effect of light polarized with microscopically rough tissues using well established physical concepts. Experimentally, we created artificial wounds on the back of animals using liquid nitrogen (this method was chosen because it does not interfere in the biochemistry of the animal tissue). For the wound irradiation we have utilized a He-Ne attached to an optical system. (author)

Thermal damage produced by high-irradiance continuous wave CO2 laser cutting of tissue.

Science.gov (United States)

Schomacker, K T; Walsh, J T; Flotte, T J; Deutsch, T F

1990-01-01

Thermal damage produced by continuous wave (cw) CO2 laser ablation of tissue in vitro was measured for irradiances ranging from 360 W/cm2 to 740 kW/cm2 in order to investigate the extent to which ablative cooling can limit tissue damage. Damage zones thinner than 100 microns were readily produced using single pulses to cut guinea pig skin as well as bovine cornea, aorta, and myocardium. Multiple pulses can lead to increased damage. However, a systematic decrease in damage with irradiance, predicted theoretically by an evaporation model of ablation, was not observed. The damage-zone thickness was approximately constant around the periphery of the cut, consistent with the existence of a liquid layer which stores heat and leads to tissue damage, and with a model of damage and ablation recently proposed by Zweig et al.

Differential gene expression profile in pig adipose tissue treated with/without clenbuterol

Directory of Open Access Journals (Sweden)

Deng Xue M

2007-11-01

Full Text Available Abstract Background Clenbuterol, a beta-agonist, can dramatically reduce pig adipose accumulation at high dosages. However, it has been banned in pig production because people who eat pig products treated with clenbuterol can be poisoned by the clenbuterol residues. To understand the molecular mechanism for this fat reduction, cDNA microarray, real-time PCR, two-dimensional electrophoresis and mass spectra were used to study the differential gene expression profiles of pig adipose tissues treated with/without clenbuterol. The objective of this research is to identify novel genes and physiological pathways that potentially facilitate clenbuterol induced reduction of adipose accumulation. Results Clenbuterol was found to improve the lean meat percentage about 10 percent (P Conclusion Pig fat accumulation was reduced dramatically with clenbuterol treatment. Histological sections and global evaluation of gene expression after administration of clenbuterol in pigs identified profound changes in adipose cells. With clenbuterol stimulation, adipose cell volumes decreased and their gene expression profile changed, which indicate some metabolism processes have been also altered. Although the biological functions of the differentially expressed genes are not completely known, higher expressions of these molecules in adipose tissue might contribute to the reduction of fat accumulation. Among these genes, five lipid metabolism related genes were of special interest for further study, including apoD and apoR. The apoR expression was increased at both the RNA and protein levels. The apoR may be one of the critical molecules through which clenbuterol reduces fat accumulation.

Thermal properties of milk fat, xanthine oxidase, caseins and whey proteins in pulsed electric field-treated bovine whole milk.

Science.gov (United States)

Sharma, Pankaj; Oey, Indrawati; Everett, David W

2016-09-15

Thermodynamics of milk components (milk fat, xanthine oxidase, caseins and whey proteins) in pulsed electric field (PEF)-treated milk were compared with thermally treated milk (63 °C for 30 min and 73 °C for 15s). PEF treatments were applied at 20 or 26 kV cm(-1) for 34 μs with or without pre-heating of milk (55 °C for 24s), using bipolar square wave pulses in a continuous mode of operation. PEF treatments did not affect the final temperatures of fat melting (Tmelting) or xanthine oxidase denaturation (Tdenaturation), whereas thermal treatments increased both the Tmelting of milk fat and the Tdenaturation for xanthine oxidase by 2-3 °C. Xanthine oxidase denaturation was ∼13% less after PEF treatments compared with the thermal treatments. The enthalpy change (ΔH of denaturation) of whey proteins decreased in the treated-milk, and denaturation increased with the treatment intensity. New endothermic peaks in the calorimetric thermograms of treated milk revealed the formation of complexes due to interactions between MFGM (milk fat globule membrane) proteins and skim milk proteins. Evidence for the adsorption of complexes onto the MFGM surface was obtained from the increase in surface hydrophobicity of proteins, revealing the presence of unfolded hydrophobic regions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of non-thermal effects from laser radiation on live tissues

International Nuclear Information System (INIS)

Cotta, M.A.

1987-02-01

The functional biological effects related to the irradiation of live tissues with low power lasers, called non-thermal effects were theoretical and experimentally studied. For the experimental part, a device which allows to: irradiation lesions artificially created on the back of rats by a He-Ne laser, or put a moving ground glass in front of the laser beam, by irradiation of this same laser with its coherence degree decreased. The relevance of the radiation coherence in the lesion cicatrization process was shown. The electrical field distribution and the intensity distribution on a surface with micro-roughness when irradiated by coherent light are theoretically studied. (M.C.K.) [pt

Removal of Cd (II from Aqueous Media by Adsorption onto Chemically and Thermally Treated Rice Husk

Directory of Open Access Journals (Sweden)

María Camila Hoyos-Sánchez

2017-01-01

Full Text Available Chemically and thermally treated rice husks were evaluated as a potential decontaminant of toxic Cd (II in aqueous media. Rice husk (RH, a by-product from rice milling, was chemically treated with HCl and NaOH. Then, thermal treatments to 300, 500, and 700°C were applied. The chemical composition and morphological characteristics of RH were evaluated by different techniques. The specific surface area analysis of RH samples by BET nitrogen adsorption method provided specific surface areas ranging from 6 to 14 m2/g. SEM, FTIR, and EDX analyses of RH were carried out to determine the surface morphology, functional groups involved in metal binding mechanism, and C/O and C/Si ratios, respectively. The maximum Cd (II adsorption capacity was 28.27 mg/g at an optimum pH, 6.0. The kinetic studies revealed that adsorption process followed the pseudo-second-order kinetic model.

Calf blood flow at rest evaluated by thermal measurement with tissue temperature and heat flow and 133Xe clearance

International Nuclear Information System (INIS)

Tamura, Toshiyo; Togawa, Tatsuo; Fukuoka, Masakazu; Kawakami, Kenji.

1982-01-01

The regional blood flow in the calf was determined simultaneously by thermal measurement and by 133 Xe clearance technique. Calf blood flow (Ft) by thermal measurement was accounted for by the equation of the form Ft=(CdT*d+Ho-Mb)/rho sub(b)c su b(D) (Ta-Td), where Cd is thermal capacitance of the calf compartment, T*d is the change of calf tissue temperature, Ta is arterila blood temperature, Td is calf tissue temperature, Ho is the heat dissipation from the compartment to the environment, Mb is estimated metabolism of the calf tissue and rho sub(b)c sub(b) is the product of density and specific heat of blood. The healthy men were chosen for the experiments. Total calf blood flow was 2.53+-1.31ml/(min-100ml calf), and muscle blood flow was 2.63+-1.69ml/(min- 100ml muscle) and skin blood flow 7.19+-3.83ml/(min-100ml skin) measured by 133 Xe clearance. On the basis of the results, an estimate has been made of the proportions of the calf volume which can be ascribed to skin and muscle respectively. Estimated muscle and skin blood flow were correlated with total calf blood flow(r=0.98). (author)

Magnetic Thermal Ablation Using Ferrofluids: Influence of Administration Mode on Biological Effect in Different Porcine Tissues

International Nuclear Information System (INIS)

Bruners, Philipp; Hodenius, Michael; Baumann, Martin; Oversohl, Jessica; Guenther, Rolf W.; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2008-01-01

The purpose of this study was to compare the effects of magnetic thermal ablation in different porcine tissues using either a singular injection or a continuous infusion of superparamagnetic iron oxide nanoparticles. In the first setting samples of three ferrofluids containing different amounts of iron (1:171, 2:192, and 3:214 mg/ml) were singularly interstitially injected into specimens of porcine liver, kidney, and muscle (n = 5). Then the specimens were exposed to an alternating magnetic field (2.86 kA/m, 190 kHz) generated by a circular coil for 5 min. In the second experimental setup ferrofluid samples were continuously interstitially infused into the tissue specimens during the exposure to the magnetic field. To measure the temperature increase two fiber-optic temperature probes with a fixed distance of 0.5 cm were inserted into the specimens along the puncture tract of the injection needle and the temperature was measured every 15 s. Finally, the specimens were dissected, the diameters of the created thermal lesions were measured, and the volumes were calculated and compared. Compared to continuous infusion, a single injection of ferrofluids resulted in smaller coagulation volumes in all tissues. Significant differences regarding coagulation volume were found in kidney and muscle specimens. The continuous infusion technique led to more elliptically shaped coagulation volumes due to larger diameters along the puncture tract. Our data show the feasibility of magnetic thermal ablation using either a single interstitial injection or continuous infusion for therapy of lesions in muscle, kidney, and liver. Continuous infusion of ferrofluids results in larger zones of necrosis compared to a single injection technique.

Experimental and computational laser tissue welding using a protein patch.

Science.gov (United States)

Small, W; Heredia, N J; Maitland, D J; Eder, D C; Celliers, P M; Da Silva, L B; London, R A; Matthews, D L

1998-01-01

An in vitro study of laser tissue welding mediated with a dye-enhanced protein patch was conducted. Fresh sections of porcine aorta were used for the experiments. Arteriotomies were treated using an indocyanine green dye-enhanced collagen patch activated by an 805-nm continuous-wave fiber-delivered diode laser. Temperature histories of the surface of the weld site were obtained using a hollow glass optical fiber-based two-color infrared thermometer. The experimental effort was complemented by simulations with the LATIS (LAser-TISsue) computer code, which uses coupled Monte Carlo, thermal transport, and mass transport models. Comparison of simulated and experimental thermal data indicated that evaporative cooling clamped the surface temperature of the weld site below 100 °C. For fluences of approximately 200 J/cm2, peak surface temperatures averaged 74°C and acute burst strengths consistently exceeded 0.14×106 dyn/cm (hoop tension). The combination of experimental and simulation results showed that the inclusion of water transport and evaporative losses in the computer code has a significant impact on the thermal distributions and hydration levels throughout the tissue volume. The solid-matrix protein patch provided a means of controllable energy delivery and yielded consistently strong welds. © 1998 Society of Photo-Optical Instrumentation Engineers.

Over one thousand patients with early stage endometriosis treated with the Helica Thermal Coagulator (HELICA): safety aspects.

Science.gov (United States)

Hill, Nicholas; McQueen, John; Morey, Richard; Hanna, Leila; Chandakas, Stefanos; El-Toukhy, Tarek; Erian, John

2006-07-01

To assess the safety of the Helica Thermal Coagulator in the laparoscopic treatment of early stage endometriosis. Retrospective, observational. The Princess Royal University Hospital, The Sloane and Chelsfield Park Hospitals, Kent, UK. One thousand and sixty patients with early stage endometriosis. All patients were treated laparoscopically with the Helica Thermal Coagulator; a new laparoscopic device that combines electrical energy with helium for the treatment of endometriosis. No major bladder, ureteric or bowel injuries occurred. The only complication was a perforated vagina from the cutting probe during dissection of the cul-de-sac in a patient with a vaginal endometriotic nodule. The Helica Thermal Coagulator is a safe device for the laparoscopic treatment of endometriosis.

Percutaneous Soft Tissue Release for Treating Chronic Recurrent Myofascial Pain Associated with Lateral Epicondylitis: 6 Case Studies

Directory of Open Access Journals (Sweden)

Ming-Ta Lin

2012-01-01

Full Text Available Objective. The purpose of this pilot study is to investigate the effectiveness of the percutaneous soft tissue release for the treatment of recurrent myofascial pain in the forearm due to recurrent lateral epicondylitis. Methods. Six patients with chronic recurrent pain in the forearm with myofascial trigger points (MTrPs due to chronic lateral epicondylitis were treated with percutaneous soft tissue release of Lin’s technique. Pain intensity (measured with a numerical pain rating scale, pressure pain threshold (measured with a pressure algometer, and grasping strength (measured with a hand dynamometer were assessed before, immediately after, and 3 months and 12 months after the treatment. Results. For every individual case, the pain intensity was significantly reduced (P<0.01 and the pressure pain threshold and the grasping strength were significantly increased (P<0.01 immediately after the treatment. This significant effectiveness lasts for at least one year. Conclusions. It is suggested that percutaneous soft tissue release can be used for treating chronic recurrent lateral epicondylitis to avoid recurrence, if other treatment, such as oral anti-inflammatory medicine, physical therapy, or local steroid injection, cannot control the recurrent pain.

Solidification and Biotoxicity Assessment of Thermally Treated Municipal Solid Waste Incineration (MSWI) Fly Ash.

Science.gov (United States)

Gong, Bing; Deng, Yi; Yang, Yuanyi; Tan, Swee Ngin; Liu, Qianni; Yang, Weizhong

2017-06-10

In the present work, thermal treatment was used to stabilize municipal solid waste incineration (MSWI) fly ash, which was considered hazardous waste. Toxicity characteristic leaching procedure (TCLP) results indicated that, after the thermal process, the leaching concentrations of Pb, Cu, and Zn decreased from 8.08 to 0.16 mg/L, 0.12 to 0.017 mg/L and 0.39 to 0.1 mg/L, respectively, which well met the limits in GB5085.3-2007 and GB16689-2008. Thermal treatment showed a negative effect on the leachability of Cr with concentrations increasing from 0.1 to 1.28 mg/L; nevertheless, it was still under the limitations. XRD analysis suggested that, after thermal treatments, CaO was newly generated. CaO was a main contribution to higher Cr leaching concentrations owing to the formation of Cr (VI)-compounds such as CaCrO₄. SEM/EDS tests revealed that particle adhesion, agglomeration, and grain growth happened during the thermal process and thus diminished the leachability of Pb, Cu, and Zn, but these processes had no significant influence on the leaching of Cr. A microbial assay demonstrated that all thermally treated samples yet possessed strong bactericidal activity according to optical density (OD) test results. Among all samples, the OD value of raw fly ash (RFA) was lowest followed by FA700-10, FA900-10, and FA1100-10 in an increasing order, which indicated that the sequence of the biotoxicity for these samples was RFA > FA700-10 > FA900-10 > FA1100-10. This preliminary study indicated that, apart from TCLP criteria, the biotoxicity assessment was indispensable for evaluating the effect of thermal treatment for MSWI fly ash.

Reusable bi-directional 3ω sensor to measure thermal conductivity of 100-μm thick biological tissues

Science.gov (United States)

Lubner, Sean D.; Choi, Jeunghwan; Wehmeyer, Geoff; Waag, Bastian; Mishra, Vivek; Natesan, Harishankar; Bischof, John C.; Dames, Chris

2015-01-01

Accurate knowledge of the thermal conductivity (k) of biological tissues is important for cryopreservation, thermal ablation, and cryosurgery. Here, we adapt the 3ω method—widely used for rigid, inorganic solids—as a reusable sensor to measure k of soft biological samples two orders of magnitude thinner than conventional tissue characterization methods. Analytical and numerical studies quantify the error of the commonly used "boundary mismatch approximation" of the bi-directional 3ω geometry, confirm that the generalized slope method is exact in the low-frequency limit, and bound its error for finite frequencies. The bi-directional 3ω measurement device is validated using control experiments to within ±2% (liquid water, standard deviation) and ±5% (ice). Measurements of mouse liver cover a temperature ranging from -69 °C to +33 °C. The liver results are independent of sample thicknesses from 3 mm down to 100 μm and agree with available literature for non-mouse liver to within the measurement scatter.

Visceral adipose tissue macrophage-targeted TACE silencing to treat obesity-induced type 2 diabetes.

Science.gov (United States)

Yong, Seok-Beom; Song, Yoonsung; Kim, Yong-Hee

2017-12-01

Obesity is an increasingly prevalent global health problem. Due to its close relations with metabolic diseases and cancer, new therapeutic approaches for treating obesity and obesity-induced metabolic diseases are required. Visceral white adipose tissue (WAT) has been closely associated with obesity-induced inflammation and adipose tissue macrophages (ATMs) are responsible for obesity-induced inflammation by releasing inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6. TNF-α converting enzyme (TACE) is a transmembrane enzyme that induces the enzymatic cleavage and release of inflammatory cytokines. In this study, we developed a nonviral gene delivery system consisting of an oligopeptide (ATS-9R) that can selectively target visceral ATMs. In here we shows visceral adipose tissue-dominant inflammatory gene over-expressions in obese mouse and our strategy enabled the preferential delivery of therapeutic genes to visceral ATMs and successfully achieved ATM-targeted gene silencing. Finally, ATS-9R-mediated TACE gene silencing in visceral ATMs alleviated visceral fat inflammation and improved type 2 diabetes by reducing whole body inflammation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Treating Cutaneous T-cell Lymphoma with Highly Irregular Surfaces with Photon Irradiation Using Rice as Tissue Compensator

Directory of Open Access Journals (Sweden)

Lonika eMajithia

2015-02-01

Full Text Available Purpose: Cutaneous T-cell lymphoma (CTCL is known to have an excellent response to radiotherapy, an important treatment modality for this disease. In patients with extremity and digit involvement, the irregular surface and depth variations create difficulty in delivering a homogenous dose using electrons. We sought to evaluate photon irradiation with rice packing as tissue equivalence and determine clinical tolerance and response. Materials and Methods: Three consecutive CTCL patients with extensive lower extremity involvement including the digits were treated using external beam photon therapy with rice packing for tissue compensation. The entire foot was treated to 30-40 Gy in 2-3 Gy per fraction using 6 MV photons prescribed to the mid-plane of an indexed box filled with rice in which the foot was placed. Optically stimulated luminescence dosimeter (OSLD was used for dose measurement to determine the dose deposition to the skin surface. Treatment tolerance and response were monitored with clinical evaluation. Results: All patients tolerated the treatment without treatment breaks. Toxicities included grade 3 erythema and desquamation with resolution within 4 weeks. No late toxicities were observed. All four treated sites had partial response (PR by the end of the treatment course. All patients reported improved functionality after treatment, with less pain, drainage, or swelling. No local recurrence has been observed in these patients with a median follow-up time of 14 months. Conclusion: Tissue compensation with rice packing offers a convenient, inexpensive and reproducible method for the treatment of CTCL with highly irregular surfaces.

Thermal and mechanical properties of NaOH treated hemp fabric and calcined nanoclay-reinforced cement nanocomposites

International Nuclear Information System (INIS)

Hakamy, A.; Shaikh, F.U.A.; Low, I.M.

2015-01-01

Highlights: • Fabrication of nanoclay and hemp fabric-reinforced cement composites. • The optimum nanoclay and hemp fabric content is 1.0 and 6.9 wt.% respectively. • Surface-treated hemp fabric-reinforced cement composites demonstrated better mechanical properties. • Surface modification of hemp fabric was effective in improving the hemp fabric-cement matrix adhesion. - Abstract: Cement nanocomposites reinforced with hemp fabrics and calcined nanoclay (CNC) have been fabricated and investigated. CNC is prepared by heating nanoclay (Cloisite 30B) at 900 °C for 2 h. The influences of CNC dispersion on the mechanical properties and thermal properties of these composites have been characterized in terms of porosity, density, water absorption, flexural strength, fracture toughness, impact strength and thermal stability. The microstructure is investigated using Quantitative X-ray Diffraction Analysis (QXDA) and High Resolution Transmission Electron Microscopy (HRTEM). The effects of alkali (NaOH) treatment of hemp fabric on the mechanical properties of hemp fabric-reinforced cement composites with different fabric contents of 4.5, 5.7, 6.9 and 8.1 wt% are also investigated. Results show that the optimum hemp fabric content is 6.9 wt% (i.e. 6 fabric layers). Results also indicated that physical, mechanical and thermal properties were enhanced due to the addition of CNC into the cement matrix and the optimum content of CNC was 1 wt%. The treated hemp fabric-reinforced nanocomposites containing 1 wt% CNC exhibited the highest flexural strength, fracture toughness, impact strength and thermal stability by virtue of good fibre–matrix interface. This environmentally friendly nanocomposite can be used for various construction applications such as ceilings and roofs

Polymer scaffolds with no skin-effect for tissue engineering applications fabricated by thermally induced phase separation

Czech Academy of Sciences Publication Activity Database

Kasoju, Naresh; Kubies, Dana; Sedlačík, Tomáš; Janoušková, Olga; Koubková, Jana; Kumorek, Marta M.; Rypáček, František

2016-01-01

Roč. 11, č. 1 (2016), 015002_1-015002_13 ISSN 1748-6041 R&D Projects: GA MŠk(CZ) EE2.3.30.0029; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61389013 Keywords : tissue engineering * porous scaffolds * thermally induced phase separation Subject RIV: CE - Biochemistry Impact factor: 2.469, year: 2016

Development of a machine treating removed shells and others in thermal and nuclear power stations

International Nuclear Information System (INIS)

Daiho, Koichi; Iwao, Takenobu

1981-01-01

The living things removed form the cooling water systems in thermal and nuclear power stations, such as shells and jelly fish, have been disposed by burying in the premises, but it is the actual situation that the occurrence of bad smell and the securing of land for burying are the worries. Accordingly, a machine for deodorizing the removed living things was manufactured for trial, and the treatment experiment was carried out in Chita Power Station. This treating machine dries the removed living things around 200 deg C, and makes the deodorizing treatment. The treated products can be utilized effectively as fertilizer, and the prospect to put this machine in practical use as a waste treatment machine of resource re-utilization type was obtained. General Technical Research Institute, Chubu Electric Power Co., Inc., has developed a machine treating abandoned fish for making organic fertilizer, and its principle was applied to the development of this treating machine. The treating capacity of this machine is 1 t/day, and the power consumption is 9.3 kW. The waste oil from power stations of about 15 l/h is used as the fuel. A crusher, a constant feed screw conveyer and a rotary kiln for drying are used. In the treating experiment, about 30 t of shells and others were treated during 51 days. The results are reported. (Kako, I.)

Skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances and lower premolar extractions.

Science.gov (United States)

Abu Alhaija, Elham S J; Al-Khateeb, Susan N

2011-05-01

Mild Class III malocciusions can be treated by upper incisor proclination and lower incisor retroclination following extraction of the lower first premolars. To compare the skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances, Class III traction and lower first premolar extractions with the changes in a group of untreated Class III patients. The Treatment group consisted of 30 Class III patients (Mean age 13.69 +/- 1.48 years) who were treated by upper and lower fixed appliances, Class III intermaxillary traction and lower first premolar extractions for 2.88 +/- 1.12 years. The Control group consisted of 20 untreated Class III patients (Mean age 13.51 +/- 0.95) matched for age and gender. The T1 to T2 changes in the treated and untreated groups were compared using a paired t-test while differences between the two groups were compared with an independent t-test. During treatment, the upper incisors were proclined about 1 degree and the lower incisors were retroclined 8 degrees. Small, but statistically significant changes in SNB, Wits and the overlying soft tissues accompanied the changes in incisor inclination. At the end of treatment a positive overbite and overjet were achieved. The increase in lower facial height in the Treatment group was comparable with the change in the Control group. A range of mild to moderate Class III malocclusions can be treated by dentoalveolar compensation.

Treating Fibrous Insulation to Reduce Thermal Conductivity

Science.gov (United States)

Zinn, Alfred; Tarkanian, Ryan

2009-01-01

A chemical treatment reduces the convective and radiative contributions to the effective thermal conductivity of porous fibrous thermal-insulation tile. The net effect of the treatment is to coat the surfaces of fibers with a mixture of transition-metal oxides (TMOs) without filling the pores. The TMO coats reduce the cross-sectional areas available for convection while absorbing and scattering thermal radiation in the pores, thereby rendering the tile largely opaque to thermal radiation. The treatment involves a sol-gel process: A solution containing a mixture of transition-metal-oxide-precursor salts plus a gelling agent (e.g., tetraethylorthosilicate) is partially cured, then, before it visibly gels, is used to impregnate the tile. The solution in the tile is gelled, then dried, and then the tile is fired to convert the precursor salts to the desired mixed TMO phases. The amounts of the various TMOs ultimately incorporated into the tile can be tailored via the concentrations of salts in the solution, and the impregnation depth can be tailored via the viscosity of the solution and/or the volume of the solution relative to that of the tile. The amounts of the TMOs determine the absorption and scattering spectra.

Thermal Stability and Surface Wettability Studies of Polylactic Acid/Halloysite Nanotube Nanocomposite Scaffold for Tissue Engineering Studies

Science.gov (United States)

Nizar, M. Mohd; Hamzah, M. S. A.; Razak, S. I. Abd; Mat Nayan, N. H.

2018-03-01

This paper reports the preliminary study about the incorporation of halloysite nanotubes (HNT) into polylactic acid (PLA) scaffold to improve the thermal resistance and surface wettability properties. The fabrication of the porous scaffold requires a simple yet effective technique with low-cost materials within freeze extraction method. The thermal stability of PLA/HNT scaffold compared to neat PLA scaffold achieved with increased content of HNT by 5 wt%. Moreover, the surface wettability of the scaffold also shows a positive impact with high content of HNT by 5 wt%. This new nanocomposite scaffold may have high potential as a suitable template for tissue regeneration.

[Pedicle flap transfer combined with external fixator to treat leg open fracture with soft tissue defect].

Science.gov (United States)

Luo, Zhongchun; Lou, Hua; Jiang, Junwei; Song, Chunlin; Gong, Min; Wang, Yongcai

2008-08-01

To investigate the clinical results of treating leg open fracture with soft tissue defect by pedicle flap transfer in combination with external fixator. From May 2004 to June 2007, 12 cases of leg open fracture with soft tissue defect, 9 males and 3 females aged 18-75 years, were treated. Among them, 8 cases were caused by traffic accidents, 2 crush, 1 falling and 1 mechanical accident. According to the Gustilo Classification, there were 2 cases of type II, 5 of type IIIA and 5 of type IIIB. There were 2 cases of upper-tibia fracture, 3 of middle-tibia and 7 of middle-lower. The sizes of soft tissue defect ranged from 5 cm x 3 cm to 22 cm x 10 cm.The sizes of exposed bone ranged from 3 cm x 2 cm to 6 cm x 3 cm. The course of the disease was 1-12 hours. Fracture fixation was reached by external fixators or external fixators and limited internal fixation with Kirschner wire. The wounds with exposed tendons and bones were repaired by ipsilateral local rotation flap, sural neurocutaneous flap and saphenous nerve flap. The size of selected flap ranged from 5 cm x 4 cm to 18 cm x 12 cm. Granulation wounds were repaired by skin grafting or direct suture. All patients were followed up for 6 months to 2 years. All patients survived, among whom 2 with the wound edge infection and 1 with the distal necrosis were cured by changing the dressing, 8 with pin hole infection were treated by taking out the external fixator, 1 with nonunion received fracture healing after bone graft in comminuted fracture of lower tibia, 2 suffered delayed union in middle-lower tibia fracture. The ROM of ankle in 3 cases was mildly poor with surpass-joint fixation, with plantar extension of 0-10 degrees and plantar flexion of 10-30 degrees, while the others had plantar extension of 10-20 degrees and plantar flexion of 30-50 degrees. The method of pedicle flap transfer combined with external fixator is safe and effective for the leg open fracture with soft tissue defect.

Irreversible electroporation ablation (IRE of unresectable soft tissue tumors: learning curve evaluation in the first 150 patients treated.

Directory of Open Access Journals (Sweden)

Prejesh Philips

Full Text Available BACKGROUND: Irreversible electroporation (IRE is a novel technology that uses peri-target discrete probes to deliver high-voltage localized electric current to induce cell death without thermal-induced coagulative necrosis. "Learnability" and consistently effective results by novice practitioners is essential for determining acceptance of novel techniques. This multi-center prospectively-collected database study evaluates the learning curve of IRE. METHODS: Analysis of 150 consecutive patients over 7 institutions from 9/2010-7/2012 was performed with patients treated divided into 3 groups A (1(st 50 patients treated, B (2(nd 50 and C (3(rd 50 patients treated chronologically and analyzed for outcomes. RESULTS: A total of 167 IRE procedures were performed, with a majority being liver(39.5% and pancreatic(35.5% lesions. The three groups were similar with respect to co-morbidities and demographics. Group C had larger lesions (3.9 vs 3 cm,p=0.001, more numerous lesions (3.2 vs 2.2,p=0.07, more vascular invasion(p=0.001, underwent more associated procedures(p=0.001 and had longer operative times(p<0.001. Despite this, they had similar complication and high-grade complication rates(p=0.24. Attributable morbidity rate was 13.3%(total 29.3% and high-grade complications were seen in 4.19%(total 12.6%. Pancreatic lesions(p=0.001 and laparotomy(p=0.001 were associated with complications. CONCLUSION: The review represents that single largest review of IRE soft tissue ablation demonstrating initial patient selection and safety. Over time, complex treatments of larger lesions and lesions with greater vascular involvement were performed without a significant increase in adverse effects or impact on local relapse free survival. This evolution demonstrates the safety profile of IRE and speed of graduation to more complex lesions, which was greater than 5 cases by institution. IRE is a safe and effective alternative to conventional ablation with a demonstrable

Functional assessments and histopathology of hepatorenal tissues of rats treated with raw and processed herbs

OpenAIRE

Ojiako, Okey A.; Chikezie, Paul C.; Ukairo, Doris I.; Ibegbulem, Chiedozie O.; Nwaoguikpe, Reginald N.

2017-01-01

The present study ascertained the functional integrity of hepatic and renal tissues, concurrently with blood lipid patterns, of Wistar rats infused with CCl4 and treated with raw and hydrothermal processed herbs, namely, Monodora myristica, Chromolaena odorata, Buccholzia coriacea and Sphenostylis stenocarpa. Measurement of phytochemical contents of the herbs was according to standard methods. The rats were randomly designated on the bases of diets and treatments received for 28 consecutive d...

Analysis of opto-thermal interaction of porcine stomach tissue with 808-nm laser for endoscopic submucosal dissection

Directory of Open Access Journals (Sweden)

Seongjun Kim

2015-11-01

Full Text Available In endoscopic submucosal dissection (ESD, the narrow gastrointestinal space can cause difficulty in surgical interventions. Tissue ablation apparatuses with high-power CO2 lasers or Nd:YAG lasers have been developed to facilitate endoscopic surgical procedures. We studied the interaction of 808-nm laser light with a porcine stomach tissue, with the aim of developing a therapeutic medical device that can remove lesions at the gastrointestinal wall by irradiating a near-infrared laser light incorporated in an endoscopic system. The perforation depths at the porcine fillet and the stomach tissues linearly increased in the range of 2–8 mm in proportion to the laser energy density of 63.7–382 kJ/cm2. Despite the distinct structural and compositional difference, the variation of the perforation depth between the stomach and the fillet was not found at 808-nm wavelength in our measurement. We further studied the laser–tissue interaction by changing the concentration of the methyl blue solution used conventionally as a submucosal fluidic cushion (SFC in ESD procedures. The temperature of the mucosal layer increased more rapidly at higher concentration of the methyl blue solution, because of enhanced light absorption at the SFC layer. The insertion of the SFC would protect the muscle layer from thermal damage. We confirmed that more effective laser treatment should be enabled by tuning the opto-thermal properties of the SFC. This study can contribute to the optimization of the driving parameters for laser incision techniques as an alternative to conventional surgical interventions.

The peculiarity of aerobic energy supply of rat tissues of different age upon prolonged ionizing and thermal exposure

International Nuclear Information System (INIS)

Tsyhun, G.F.

1998-01-01

Energy-producing functions of brain, myocardium, and hepatic mitochondria in mature and immature rats in remote period after prolonged ionizing X-ray at total dose 12,9 m C/kg and thermal exposure (4 hours, 37 degrees centigrade, 25 times) were studied. Dehydrogenase activities (pyruvate-, isocitrate-, 2-oxy glutarate-, succinate- and malate dehydrogenases) were reduced in mitochondria of different tissues of adult rats and it was especially considerable after combined influence. A higher resistance of young rats, as compared to adult ones, to combined radiation-thermal treatments was established

Thermal Diffusivity Measurements in Edible Oils using Transient Thermal Lens

Science.gov (United States)

Valdez, R. Carbajal.; Pérez, J. L. Jiménez.; Cruz-Orea, A.; Martín-Martínez, E. San.

2006-11-01

Time resolved thermal lens (TL) spectrometry is applied to the study of the thermal diffusivity of edible oils such as olive, and refined and thermally treated avocado oils. A two laser mismatched-mode experimental configuration was used, with a He Ne laser as a probe beam and an Ar+ laser as the excitation one. The characteristic time constant of the transient thermal lens was obtained by fitting the experimental data to the theoretical expression for a transient thermal lens. The results showed that virgin olive oil has a higher thermal diffusivity than for refined and thermally treated avocado oils. This measured thermal property may contribute to a better understanding of the quality of edible oils, which is very important in the food industry. The thermal diffusivity results for virgin olive oil, obtained from this technique, agree with those reported in the literature.

The effects of LIPUS on soft-tissue healing: a review of literature.

Science.gov (United States)

Khanna, Anil; Nelmes, Richard T C; Gougoulias, Nikolaos; Maffulli, Nicola; Gray, Jim

2009-01-01

Ultrasound is widely used for imaging purposes and as an adjunct to physiotherapy. Low-intensity pulsed ultrasound (LIPUS), having removed the thermal component found at higher intensities, is used to improve bone healing. However, its potential role in soft-tissue healing is still under investigation. We searched on Medline using the keywords: low-intensity pulsed ultrasound, LIPUS and LIPUS and soft-tissue healing. Thirty-two suitable articles were identified. Research, mainly pre-clinical, so far has shown encouraging result, with LIPUS able to promote healing in various soft tissues such as cartilage, inter-vertebral disc, etc. The effect on the bone-tendon junction, however, is primarily on bone. The role of LIPUS in treating tendinopathies is questionable. Adequately powered human studies with standardisation of intensities and dosages of LIPUS for each target tissue are needed.

Numerical simulation of time fractional dual-phase-lag model of heat transfer within skin tissue during thermal therapy.

Science.gov (United States)

Kumar, Dinesh; Rai, K N

2017-07-01

In this paper, we investigated the thermal behavior in living biological tissues using time fractional dual-phase-lag bioheat transfer (DPLBHT) model subjected to Dirichelt boundary condition in presence of metabolic and electromagnetic heat sources during thermal therapy. We solved this bioheat transfer model using finite element Legendre wavelet Galerkin method (FELWGM) with help of block pulse function in sense of Caputo fractional order derivative. We compared the obtained results from FELWGM and exact method in a specific case, and found a high accuracy. Results are interpreted in the form of standard and anomalous cases for taking different order of time fractional DPLBHT model. The time to achieve hyperthermia position is discussed in both cases as standard and time fractional order derivative. The success of thermal therapy in the treatment of metastatic cancerous cell depends on time fractional order derivative to precise prediction and control of temperature. The effect of variability of parameters such as time fractional derivative, lagging times, blood perfusion coefficient, metabolic heat source and transmitted power on dimensionless temperature distribution in skin tissue is discussed in detail. The physiological parameters has been estimated, corresponding to the value of fractional order derivative for hyperthermia treatment therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Opto-acoustic diagnostics of the thermal action of high-intensity focused ultrasound on biological tissues: the possibility of its applications and model experiments

International Nuclear Information System (INIS)

Khokhlova, Tanya D; Pelivanov, Ivan M; Solomatin, Vladimir S; Karabutov, Aleksander A; Sapozhnikov, Oleg A

2006-01-01

The possibility of using the opto-acoustic (OA) method for monitoring high-intensity ultrasonic therapy is studied. The optical properties of raw and boiled liver samples used as the undamaged model tissue and tissue destroyed by ultrasound, respectively, are measured. Experiments are performed with samples consisting of several alternating layers of raw and boiled liver of different thickness. The position and transverse size of the thermal lesion were determined from the temporal shape of the OA signals. The results of measurements are compared with the real size and position of the thermal lesion determined from the subsequent cuts of the sample. It is shown that the OA method permits the diagnostics of variations in biological tissues upon ultrasonic therapy. (special issue devoted to multiple radiation scattering in random media)

Autoradiographic demonstration of unscheduled DNA synthesis in oral tissues treated with chemical carcinogens in short-term organ culture

International Nuclear Information System (INIS)

Ide, F.; Umemura, S.; Ishikawa, T.; Takayama, S.

1981-01-01

A system in which oral tissues of inbred F344 adult rats and Syrian golden hamster embryos were used in combination with autoradiography was developed for measurement of unscheduled DNA synthesis (UDS). For this, oral mucosa, submandibular gland, tooth germ and mandible in short-term organ cultures were treated with 4-nitroquinoline l-oxide or N-methyl-N-nitrosourea plus (methyl- 3 H)thymidine. Significant numbers of silver grains, indicating UDS, were detected over the nuclei of cells of all these tissues except rat salivary gland after treatment with carcinogens. This autoradiographic method is suitable for detection of UDS in oral tissues in conditions mimicking those in vivo. Results obtained in this study indicated a potential use of this system for studies on the mechanism of carcinogenesis at a cellular level comparable to in vivo carcinogenesis studies on oral tissues. (author)

Use of autologous tissue engineered skin to treat porcine full-thickness skin defects

Institute of Scientific and Technical Information of China (English)

CAI Xia; CAO Yi-lin; CUI Lei; LIU Wei; GUAN Wen-xiang

2005-01-01

Objective: To explore a feasible method to repair full-thickness skin defects utilizing tissue engineered techniques. Methods: The Changfeng hybrid swines were used and the skin specimens were cut from the posterior limb girdle region, from which the keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA, and type II collagenase. The cells were seeded in Petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with trypsin to separate them from the floor of the tissue culture dishes. A biodegradable material, Pluronic F-127, was prefabricated and mixed with these cells, and then the cell-Pluronic compounds were seeded evenly into a polyglycolic acid (PGA). Then the constructs were replanted to the autologous animals to repair the full-thickness skin defects. Histology and immunohistochemistry of the neotissue were observed in 1, 2, 4, and 8 postoperative weeks. Results: The cell-Pluronic F-127-PGA compounds repaired autologous full-thickness skin defects 1 week after implantation. Histologically, the tissue engineered skin was similar to the normal skin with stratified epidermis overlying a moderately thick collageneous dermis. Three of the structural proteins in the epidermal basement membrane zone, type IV collagen, laminin, and type VII collagen were detected using immunohistochemical methods. Conclusions: By studying the histology and immunohistochemistry of the neotissue, the bioengineered skin graft holds great promise for improving healing of the skin defects.

Nonlinear side effects of fs pulses inside corneal tissue during photodisruption

Science.gov (United States)

Heisterkamp, A.; Ripken, T.; Mamom, T.; Drommer, W.; Welling, H.; Ertmer, W.; Lubatschowski, H.

In order to evaluate the potential for refractive surgery, fs laser pulses of 150-fs pulse duration were used to process corneal tissue of dead and living animal eyes. By focusing the laser radiation down to spot sizes of several microns, very precise cuts could be achieved inside the treated cornea, accompanied with minimum collateral damage to the tissue by thermal or mechanical effects. During histo-pathological analysis by light and transmission electron microscopy considerable side effects of fs photodisruption were found. Due to the high intensities at the focal region several nonlinear effects occurred. Self-focusing, photodissociation, UV-light production were observed, leading to streak formation inside the cornea.

Microtexture of the thermally grown alumina in commercial thermal barrier coatings

Energy Technology Data Exchange (ETDEWEB)

Karadge, M. [School of Materials, University of Manchester, Grosvenor St., Manchester M1 7HS (United Kingdom); Zhao, X. [School of Materials, University of Manchester, Grosvenor St., Manchester M1 7HS (United Kingdom); Preuss, M. [School of Materials, University of Manchester, Grosvenor St., Manchester M1 7HS (United Kingdom); Xiao, P. [School of Materials, University of Manchester, Grosvenor St., Manchester M1 7HS (United Kingdom)]. E-mail: Ping.Xiao@manchester.ac.uk

2006-02-15

otextures of the thermally grown {alpha}-alumina (TGO) in isothermally treated and thermal cycled electron beam physical vapor deposited thermal barrier coatings (EB-PVD-TBC) and isothermally treated air plasma sprayed (APS-TBC) specimens were studied by high resolution electron back-scattered diffraction. The TGO in EB-PVD specimens exhibited a basal microtexture. The TGO in APS specimens, however, did not show any significant microtexture development.

Direct plasma interaction with living tissue

Science.gov (United States)

Fridman, Gregory

For some time, plasma has been used in medicine to cauterize or cut tissue using heat and mechanical energy. In the recent decade, some researchers around the world have started to investigate how gas jets that pass through thermal plasma can be employed in medicine. This thesis presents the first investigation of biomedical uses of non-thermal plasma discharge which comes in direct contact with living tissue. It is demonstrated that the direct application of non-thermal plasma in air can cause rapid deactivation of bacteria on surfaces of tissues without causing any visible tissue damage. Medical need for such a device is discussed. Construction and operation of various types of non-thermal plasma power supplies and many types of treatment electrodes are presented as well. Application of this plasma to living organisms is shown to be safe from both the electrical perspective and from the biological perspective. Biological safety is revealed through a series of differential skin toxicity trials on human cadaver tissue, live hairless mouse skin tissue, live pig skin tissue, and finally in an open wound model on pigs. Direct non-thermal plasma in air is shown to deactivate bacteria about 100 times faster than indirect application using jets. A series of experiments reveal that this effectiveness is due to the ability of direct discharge to bring charges to tissue surfaces. It is demonstrated that neither ultraviolet (UV) radiation nor neutral active species such as hydroxyl radicals or ozone produced in plasma are responsible for the main effect on bacteria. Although much additional work remains on establishing detailed mechanism by which charges from plasma achieve this effect, the work carried out in this thesis clearly demonstrates that direct application of non-thermal plasma in air can be a very useful tool in medicine.

Skin grafting and tissue replacement for treating foot ulcers in people with diabetes.

Science.gov (United States)

Santema, Trientje B; Poyck, Paul P C; Ubbink, Dirk T

2016-02-11

Foot ulceration is a major problem in people with diabetes and is the leading cause of hospitalisation and limb amputations. Skin grafts and tissue replacements can be used to reconstruct skin defects for people with diabetic foot ulcers in addition to providing them with standard care. Skin substitutes can consist of bioengineered or artificial skin, autografts (taken from the patient), allografts (taken from another person) or xenografts (taken from animals). To determine the benefits and harms of skin grafting and tissue replacement for treating foot ulcers in people with diabetes. In April 2015 we searched: The Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE and EBSCO CINAHL. We also searched clinical trial registries to identify ongoing studies. We did not apply restrictions to language, date of publication or study setting. Randomised clinical trials (RCTs) of skin grafts or tissue replacements for treating foot ulcers in people with diabetes. Two review authors independently extracted data and assessed the quality of the included studies. We included seventeen studies with a total of 1655 randomised participants in this review. Risk of bias was variable among studies. Blinding of participants, personnel and outcome assessment was not possible in most trials because of obvious differences between the treatments. The lack of a blinded outcome assessor may have caused detection bias when ulcer healing was assessed. However, possible detection bias is hard to prevent due to the nature of the skin replacement products we assessed, and the fact that they are easily recognisable. Strikingly, nearly all studies (15/17) reported industry involvement; at least one of the authors was connected to a commercial organisation or the study was funded by a commercial organisation. In addition, the funnel plot for

Harmonic motion imaging for focused ultrasound (HMIFU): a fully integrated technique for sonication and monitoring of thermal ablation in tissues

International Nuclear Information System (INIS)

Maleke, C; Konofagou, E E

2008-01-01

FUS (focused ultrasound), or HIFU (high-intensity-focused ultrasound) therapy, a minimally or non-invasive procedure that uses ultrasound to generate thermal necrosis, has been proven successful in several clinical applications. This paper discusses a method for monitoring thermal treatment at different sonication durations (10 s, 20 s and 30 s) using the amplitude-modulated (AM) harmonic motion imaging for focused ultrasound (HMIFU) technique in bovine liver samples in vitro. The feasibility of HMI for characterizing mechanical tissue properties has previously been demonstrated. Here, a confocal transducer, combining a 4.68 MHz therapy (FUS) and a 7.5 MHz diagnostic (pulse-echo) transducer, was used. The therapy transducer was driven by a low-frequency AM continuous signal at 25 Hz, producing a stable harmonic radiation force oscillating at the modulation frequency. A pulser/receiver was used to drive the pulse-echo transducer at a pulse repetition frequency (PRF) of 5.4 kHz. Radio-frequency (RF) signals were acquired using a standard pulse-echo technique. The temperature near the ablation region was simultaneously monitored. Both RF signals and temperature measurements were obtained before, during and after sonication. The resulting axial tissue displacement was estimated using one-dimensional cross correlation. When temperature at the focal zone was above 48 deg. C during heating, the coagulation necrosis occurred and tissue damage was irreversible. The HMI displacement profiles in relation to the temperature and sonication durations were analyzed. At the beginning of heating, the temperature at the focus increased sharply, while the tissue stiffness decreased resulting in higher HMI displacements. This was confirmed by an increase of 0.8 μm deg. C -1 (r = 0.93, p -1 , r = -0.92, p -1 , prior to and after lesion formation in seven bovine liver samples, respectively. This technique was thus capable of following the protein-denatured lesion formation based on the

Changes in the vascular tissue of fresh Hass avocados treated with cobalt

International Nuclear Information System (INIS)

Arevalo, Lourdes; Bustos, Ma. Emilia; Saucedo, Cresenciano

2002-01-01

This research was based on fresh avocado fruit treated with gamma rays at quarantine doses and stored at room temperature. The effects of irradiation were analyzed and measured by three different types of studies: histological, biochemical and physiological. Histological studies were focused on the effect of Cobalt 60 gamma rays in the mesocarp of avocado irradiated at three different doses; 150, 250, and 350 Gy. Damage was observed principally in the parenchyma tissue where the cell membrane was plazmolized and a red color was observed due to the development of phenol compounds. Another important effect was an increase in the size of xylem and phloem cells in the vascular tissue even at the minimum dose of 150 Gy. The biochemical and the physiological studies were done on avocado fruit irradiated at 100 and 150 Gy. An increase in L-phenilalanine ammonialyase activity was observed and therefore, an increase in the concentration of phenol compounds. These changes were not perceived by panelists in a sensorial test. Irradiated fruits were accepted by panelists as well as control fruit as regards parameters of taste, internal color and external color. These results demonstrate the feasibility of using irradiation to disinfest avocado fruit using a minimum dose of 100 Gy

Changes in the vascular tissue of fresh Hass avocados treated with cobalt

Energy Technology Data Exchange (ETDEWEB)

Arevalo, Lourdes; Bustos, Ma. Emilia; Saucedo, Cresenciano

2002-03-01

This research was based on fresh avocado fruit treated with gamma rays at quarantine doses and stored at room temperature. The effects of irradiation were analyzed and measured by three different types of studies: histological, biochemical and physiological. Histological studies were focused on the effect of Cobalt 60 gamma rays in the mesocarp of avocado irradiated at three different doses; 150, 250, and 350 Gy. Damage was observed principally in the parenchyma tissue where the cell membrane was plazmolized and a red color was observed due to the development of phenol compounds. Another important effect was an increase in the size of xylem and phloem cells in the vascular tissue even at the minimum dose of 150 Gy. The biochemical and the physiological studies were done on avocado fruit irradiated at 100 and 150 Gy. An increase in L-phenilalanine ammonialyase activity was observed and therefore, an increase in the concentration of phenol compounds. These changes were not perceived by panelists in a sensorial test. Irradiated fruits were accepted by panelists as well as control fruit as regards parameters of taste, internal color and external color. These results demonstrate the feasibility of using irradiation to disinfest avocado fruit using a minimum dose of 100 Gy.

High-speed scanning ablation of dental hard tissues with a λ=9.3-μm CO2 laser: heat accumulation and peripheral thermal damage

Science.gov (United States)

Nguyen, Daniel; Staninec, Michal; Lee, Chulsung; Fried, Daniel

2010-02-01

A mechanically scanned CO2 laser operated at high laser pulse repetition rates can be used to rapidly and precisely remove dental decay. This study aims to determine whether these laser systems can safely ablate enamel and dentin without excessive heat accumulation and peripheral thermal damage. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. Samples were derived from noncarious extracted molars. Pulpal temperatures were recorded using microthermocouples situated at the pulp chamber roof of samples (n=12), which were occlusally ablated using a rapid-scanning, water-cooled 300 Hz CO2 laser over a two minute time course. The mechanical strength of facially ablated dentin (n=10) was determined via four-point bend test and compared to control samples (n=10) prepared with 320 grit wet sand paper to simulate conventional preparations. Composite-to-enamel bond strength was measured via single-plane shear test for ablated/non-etched (n=10) and ablated/acid-etched (n=8) samples and compared to control samples (n=9) prepared by 320 grit wet sanding. Thermocouple measurements indicated that the temperature remained below ambient temperature at 19.0°C (s.d.=0.9) if water-cooling was used. There was no discoloration of either dentin and enamel, the treated surfaces were uniformly ablated and there were no cracks observable on the laser treated surfaces. Fourpoint bend tests yielded mean mechanical strengths of 18.2 N (s.d.=4.6) for ablated dentin and 18.1 N (s.d.=2.7) for control (p>0.05). Shear tests yielded mean bond strengths of 31.2 MPa (s.d.=2.5, penamel without excessive heat accumulation and with minimal thermal damage. It is not clear whether the small (16%) but statistically significant reduction in the shear bond strength to enamel is clinically significant since the mean shear bond strength exceeded 30 MPa.

Tissue-engineered trachea regeneration using decellularized trachea matrix treated with laser micropore technique.

Science.gov (United States)

Xu, Yong; Li, Dan; Yin, Zongqi; He, Aijuan; Lin, Miaomiao; Jiang, Gening; Song, Xiao; Hu, Xuefei; Liu, Yi; Wang, Jinpeng; Wang, Xiaoyun; Duan, Liang; Zhou, Guangdong

2017-08-01

Tissue-engineered trachea provides a promising approach for reconstruction of long segmental tracheal defects. However, a lack of ideal biodegradable scaffolds greatly restricts its clinical translation. Decellularized trachea matrix (DTM) is considered a proper scaffold for trachea cartilage regeneration owing to natural tubular structure, cartilage matrix components, and biodegradability. However, cell residual and low porosity of DTM easily result in immunogenicity and incomplete cartilage regeneration. To address these problems, a laser micropore technique (LMT) was applied in the current study to modify trachea sample porosity to facilitate decellular treatment and cell ingrowth. Decellularization processing demonstrated that cells in LMT treated samples were more easily removed compared with untreated native trachea. Furthermore, after optimizing the protocols of LMT and decellular treatments, the LMT-treated DTM (LDTM) could retain their original tubular shape with only mild extracellular matrix damage. After seeding with chondrocytes and culture in vitro for 8 weeks, the cell-LDTM constructs formed tubular cartilage with relatively homogenous cell distribution in both micropores and bilateral surfaces. In vivo results further confirmed that the constructs could form mature tubular cartilage with increased DNA and cartilage matrix contents, as well as enhanced mechanical strength, compared with native trachea. Collectively, these results indicate that LDTM is an ideal scaffold for tubular cartilage regeneration and, thus, provides a promising strategy for functional reconstruction of trachea cartilage. Lacking ideal biodegradable scaffolds greatly restricts development of tissue-engineered trachea. Decellularized trachea matrix (DTM) is considered a proper scaffold for trachea cartilage regeneration. However, cell residual and low porosity of DTM easily result in immunogenicity and incomplete cartilage regeneration. By laser micropore technique (LMT), the

The Histological, Histomorphometrical and Histochemical Changes of Testicular Tissue in the Metformin Treated and Untreated Streptozotocin-Induced Adult Diabetic Rats

Directory of Open Access Journals (Sweden)

Davoud Kianifard

2011-03-01

Full Text Available In this investigation, diabetes was induced in adult male Sprague-Dawley rats by single intraperitoneal injection of streptozotocin (STZ at 45 mg kg-1 of body weight. A group comprised of 8 diabetic rats was treated with metformin at 100 mg kg-1 of body weight for reducing the elevated blood glucose level. The results revealed that, in the untreated diabetic rats, the body and testicular weight reduced in comparison with the control rats (P < 0.05 , the metformin treated diabetic rats showed body weight loss in comparison with the control group (P < 0.05. In the untreated diabetic rats, the blood glucose level significantly increased in comparison with control and metformin treated diabetic rats. Histomorphological examinations revealed a reduction in testicular capsule diameter, seminiferous tubules (STs and germinal epithelium height, increase of amorphous material of interstitial tissue, germ cell depletion, decrease in cellular population and activity and disruption of spermatogenesis in the untreated diabetic rats in comparison with control group. In metformin treated diabetic rats, the histomorphological alterations were seen in lesser part in comparison with untreated diabetic group. The results from this study proved that, there was a direct relationship between increased levels of blood glucose as a result of STZ-induced diabetes and the histomorphological changes of testicular tissue.

Photothermal effects of laser tissue soldering

International Nuclear Information System (INIS)

McNally, K.M.; Sorg, B.S.; Welch, A.J.; Dawes, J.M.; Owen, E.R.

1999-01-01

Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding technique in which a protein solder is applied to the tissue surfaces to be joined, and laser energy is used to bond the solder to the tissue surfaces. The addition of protein solders to augment tissue repair procedures significantly reduces the problems of low strength and thermal damage associated with laser tissue welding techniques. Investigations were conducted to determine optimal solder and laser parameters for tissue repair in terms of tensile strength, temperature rise and damage and the microscopic nature of the bonds formed. An in vitro study was performed using an 808 nm diode laser in conjunction with indocyanine green (ICG)-doped albumin protein solders to repair bovine aorta specimens. Liquid and solid protein solders prepared from 25% and 60% bovine serum albumin (BSA), respectively, were compared. The efficacy of temperature feedback control in enhancing the soldering process was also investigated. Increasing the BSA concentration from 25% to 60% greatly increased the tensile strength of the repairs. A reduction in dye concentration from 2.5mgml -1 to 0.25mgml -1 was also found to result in an increase in tensile strength. Increasing the laser irradiance and thus surface temperature resulted in an increased severity of histological injury. Thermal denaturation of tissue collagen and necrosis of the intimal layer smooth muscle cells increased laterally and in depth with higher temperatures. The strongest repairs were produced with an irradiance of 6.4Wcm -2 using a solid protein solder composed of 60% BSA and 0.25mgml -1 ICG. Using this combination of laser and solder parameters, surface temperatures were observed to reach 85±5 deg. C with a

Luminescent nanoprobes for thermal bio-sensing: Towards controlled photo-thermal therapies

Energy Technology Data Exchange (ETDEWEB)

Jaque, Daniel, E-mail: daniel.jaque@uam.es [Fluorescence Imaging Group, Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Madrid 28049 (Spain); Grupo de Fotônica e Fluidos Complexos (GFFC), Instituto de Física, Universidade Federal de Alagoas, 57072-900 Maceió-AL (Brazil); Jacinto, Carlos [Grupo de Fotônica e Fluidos Complexos (GFFC), Instituto de Física, Universidade Federal de Alagoas, 57072-900 Maceió-AL (Brazil)

2016-01-15

Photo-thermal therapies, based on the light-induced local heating of cancer tumors and tissues, are nowadays attracting an increasing attention due to their effectiveness, universality, and low cost. In order to avoid undesirable collateral damage in the healthy tissues surrounding the tumors, photo-thermal therapies should be achieved while monitoring tumor’s temperature in such a way that thermal therapy could be stopped before reaching the damage limit. Measuring tumor temperature is not an easy task at all and novel strategies should be adopted. In this work it is demonstrated how luminescent nanoparticles, in particular Neodymium doped LaF{sub 3} nanoparticles, could be used as multi-functional agents capable of simultaneous heating and thermal sensing. Advantages and disadvantages of such nanoparticles are discussed and the future perspectives are briefly raised. - Highlights: • Thermal control is essential in novel photo-thermal therapies. • Thermal control and heating can be achieved by Neodymium doped nanoparticles. • Perspectives of Neodymium doped nanoparticles in potential in vivo applications are discussed.

Simulating the swelling and deformation behaviour in soft tissues using a convective thermal analogy

Directory of Open Access Journals (Sweden)

Herzog Walter

2002-12-01

Full Text Available Abstract Background It is generally accepted that cartilage adaptation and degeneration are mechanically mediated. Investigating the swelling behaviour of cartilage is important because the stress and strain state of cartilage is associated with the swelling and deformation behaviour. It is well accepted that the swelling of soft tissues is associated with mechanical, chemical, and electrical events. Method The purpose of the present study was to implement the triphasic theory into a commercial finite element tool (ABAQUS to solve practical problems in cartilage mechanics. Because of the mathematical identity between thermal and mass diffusion processes, the triphasic model was transferred into a convective thermal diffusion process in the commercial finite element software. The problem was solved using an iterative procedure. Results The proposed approach was validated using the one-dimensional numerical solutions and the experimental results of confined compression of articular cartilage described in the literature. The time-history of the force response of a cartilage specimen in confined compression, which was subjected to swelling caused by a sudden change of saline concentration, was predicted using the proposed approach and compared with the published experimental data. Conclusion The advantage of the proposed thermal analogy technique over previous studies is that it accounts for the convective diffusion of ion concentrations and the Donnan osmotic pressure in the interstitial fluid.

Chronic ankle pain and fibrosis successfully treated with a new noninvasive augmented soft tissue mobilization technique (ASTM): a case report.

Science.gov (United States)

Melham, T J; Sevier, T L; Malnofski, M J; Wilson, J K; Helfst, R H

1998-06-01

This clinical case report demonstrates the clinical effectiveness of a new form of soft tissue mobilization in the treatment of excessive connective tissue fibrosis (scar tissue) around an athlete's injured ankle. The scar tissue was causing the athlete to have pain with activity, pain on palpation of the ankle, decreased range of motion, and loss of function. Surgery and several months of conventional physical therapy failed to alleviate the athlete's symptoms. As a final resort, augmented soft tissue mobilization (ASTM) was administered. ASTM is an alternative nonsurgical treatment modality that is being researched at Performance Dynamics (Muncip, IN). ASTM is a process that uses ergonomically designed instruments that assist therapists in the rapid localization and effective treatment of areas exhibiting excessive soft tissue fibrosis. This is followed by a stretching and strengthening program. Upon the completion of 6 wk of ASTM therapy, the athlete had no pain and had regained full range of motion and function. This case report is an example of how a noninvasive augmented form of soft tissue mobilization (ASTM) demonstrated impressive clinical results in treating a condition caused by connective tissue fibrosis.

A comparison of survival of patients treated for AIDS-related central nervous system lymphoma with and without tissue diagnosis

International Nuclear Information System (INIS)

Kaufmann, Thomas; Nisce, Lourdes Z.; Coleman, Morton

1996-01-01

Purpose: This is a retrospective review of the treatment outcome of radiation therapy (RT) in acquired immunedeficiency syndrome (AIDS) patients with presumed primary central nervous system (CNS) non-Hodgkin's lymphoma (NHL), with and without tissue verification. Methods and Materials: Twenty-seven patients with AIDS-related CNS NHL were treated between 1986 and 1992. They were divided into two groups. Group 1 consisted of nine patients with a positive histology for NHL. They were treated with dexamethasone (DXM) and whole brain RT. Group 2 consisted of 18 patients who, because of unique circumstances, were treated without histologic confirmation of NHL. Rapid clinical and/or radiologic response to DXM and whole-brain RT was interpreted as NHL. Results: For group 1, the response rate was 87.5%, mean survival 6.1 months, and median survival 4.5 months. For group 2, the response rate was 72.2%, mean survival 5.2 months, and median survival 4.5 months. The overall response rate was 76.9%, mean survival 5.8 months, and median survival 4.5 months. Conclusions: In instances where a tissue diagnosis cannot be established, a positive response to an empiric trial of DXM and RT to 20 Gy may constitute presumptive evidence of NHL

Combining mechanical foaming and thermally induced phase separation to generate chitosan scaffolds for soft tissue engineering.

Science.gov (United States)

Biswas, D P; Tran, P A; Tallon, C; O'Connor, A J

2017-02-01

In this paper, a novel foaming methodology consisting of turbulent mixing and thermally induced phase separation (TIPS) was used to generate scaffolds for tissue engineering. Air bubbles were mechanically introduced into a chitosan solution which forms the continuous polymer/liquid phase in the foam created. The air bubbles entrained in the foam act as a template for the macroporous architecture of the final scaffolds. Wet foams were crosslinked via glutaraldehyde and frozen at -20 °C to induce TIPS in order to limit film drainage, bubble coalescence and Ostwald ripening. The effects of production parameters, including mixing speed, surfactant concentration and chitosan concentration, on foaming are explored. Using this method, hydrogel scaffolds were successfully produced with up to 80% porosity, average pore sizes of 120 μm and readily tuneable compressive modulus in the range of 2.6 to 25 kPa relevant to soft tissue engineering applications. These scaffolds supported 3T3 fibroblast cell proliferation and penetration and therefore show significant potential for application in soft tissue engineering.

Characterisation of tissue shrinkage during microwave thermal ablation.

Science.gov (United States)

Farina, Laura; Weiss, Noam; Nissenbaum, Yitzhak; Cavagnaro, Marta; Lopresto, Vanni; Pinto, Rosanna; Tosoratti, Nevio; Amabile, Claudio; Cassarino, Simone; Goldberg, S Nahum

2014-11-01

The aim of this study was to characterise changes in tissue volume during image-guided microwave ablation in order to arrive at a more precise determination of the true ablation zone. The effect of power (20-80 W) and time (1-10 min) on microwave-induced tissue contraction was experimentally evaluated in various-sized cubes of ex vivo liver (10-40 mm ± 2 mm) and muscle (20 and 40 mm ± 2 mm) embedded in agar phantoms (N = 119). Post-ablation linear and volumetric dimensions of the tissue cubes were measured and compared with pre-ablation dimensions. Subsequently, the process of tissue contraction was investigated dynamically during the ablation procedure through real-time X-ray CT scanning. Overall, substantial shrinkage of 52-74% of initial tissue volume was noted. The shrinkage was non-uniform over time and space, with observed asymmetry favouring the radial (23-43 % range) over the longitudinal (21-29%) direction. Algorithmic relationships for the shrinkage as a function of time were demonstrated. Furthermore, the smallest cubes showed more substantial and faster contraction (28-40% after 1 min), with more considerable volumetric shrinkage (>10%) in muscle than in liver tissue. Additionally, CT imaging demonstrated initial expansion of the tissue volume, lasting in some cases up to 3 min during the microwave ablation procedure, prior to the contraction phenomenon. In addition to an asymmetric substantial shrinkage of the ablated tissue volume, an initial expansion phenomenon occurs during MW ablation. Thus, complex modifications of the tissue close to a radiating antenna will likely need to be taken into account for future methods of real-time ablation monitoring.

Biological functioning of PAH-polluted and thermal desorption-treated soils assessed by fauna and microbial bioindicators.

Science.gov (United States)

Cébron, Aurélie; Cortet, Jérôme; Criquet, Stéven; Biaz, Asmaa; Calvert, Virgile; Caupert, Cécile; Pernin, Céline; Leyval, Corinne

2011-11-01

A large number of soil bioindicators were used to assess biological diversity and activity in soil polluted with polycyclic aromatic hydrocarbons (PAHs) and the same soil after thermal desorption (TD) treatment. Abundance and biodiversity of bacteria, fungi, protozoa, nematodes and microarthropods, as well as functional parameters such as enzymatic activities and soil respiration, were assessed during a two year period of in situ monitoring. We investigated the influence of vegetation (spontaneous vegetation and Medicago sativa) and TD treatment on biological functioning. Multivariate analysis was performed to analyze the whole data set. A principal response curve (PRC) technique was used to evaluate the different treatments (various vegetation and contaminated vs. TD soil) contrasted with control (bare) soil over time. Our results indicated the value of using a number of complementary bioindicators, describing both diversity and functions, to assess the influence of vegetation on soil and discriminate polluted from thermal desorption (TD)-treated soil. Plants had an influence on the abundance and activity of all organisms examined in our study, favoring the whole trophic chain development. However, although TD-treated soil had a high abundance and diversity of microorganisms and fauna, enzymatic activities were weak because of the strong physical and chemical modifications of this soil. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

The Research on Thermal Properties and Hydrophobility of the Native Starch/hydrolysis Starch Blends with Treated CaCO3 Powder

Science.gov (United States)

Liu, Chia-I.; Huang, Chi-Yuan

2008-08-01

In this research, hydrolysis starch was added into the starch blends to study the thermal properties. The enthalpy of blends had a significant decrease to 109J/g as content of treated CaCO3 increased to 5wt%. The modified starch was degraded slightly to produce glucose in the hydrolysis treatment. The amount of glucose in native starch and hydrolysis starch was 0.09 μmol and 0.14 μmol by the DNS measurement. Moreover, CaCO3 treated with titanium coupling agent was also added to improve miscibility and hydrophobility in the starch blends. The contact angle of the blends increased from 60° to 95° when 15wt% treated CaCO3 was added. Treated CaCO3 was confirmed to improve the hydrophobility of starch blends effectively.

THE RESEARCH ON THERMAL PROPERTIES AND HYDROPHOBILITY OF THE NATIVE STARCH/HYDROLYSIS STARCH BLENDS WITH TREATED CaCO3 POWDER

International Nuclear Information System (INIS)

Liu, C.-I; Huang, C.-Y.

2008-01-01

In this research, hydrolysis starch was added into the starch blends to study the thermal properties. The enthalpy of blends had a significant decrease to 109J/g as content of treated CaCO 3 increased to 5wt%. The modified starch was degraded slightly to produce glucose in the hydrolysis treatment. The amount of glucose in native starch and hydrolysis starch was 0.09 μmol and 0.14 μmol by the DNS measurement. Moreover, CaCO 3 treated with titanium coupling agent was also added to improve miscibility and hydrophobility in the starch blends. The contact angle of the blends increased from 60 deg. to 95 deg. when 15wt% treated CaCO 3 was added. Treated CaCO 3 was confirmed to improve the hydrophobility of starch blends effectively

A deep learning approach to estimate chemically-treated collagenous tissue nonlinear anisotropic stress-strain responses from microscopy images.

Science.gov (United States)

Liang, Liang; Liu, Minliang; Sun, Wei

2017-11-01

Biological collagenous tissues comprised of networks of collagen fibers are suitable for a broad spectrum of medical applications owing to their attractive mechanical properties. In this study, we developed a noninvasive approach to estimate collagenous tissue elastic properties directly from microscopy images using Machine Learning (ML) techniques. Glutaraldehyde-treated bovine pericardium (GLBP) tissue, widely used in the fabrication of bioprosthetic heart valves and vascular patches, was chosen to develop a representative application. A Deep Learning model was designed and trained to process second harmonic generation (SHG) images of collagen networks in GLBP tissue samples, and directly predict the tissue elastic mechanical properties. The trained model is capable of identifying the overall tissue stiffness with a classification accuracy of 84%, and predicting the nonlinear anisotropic stress-strain curves with average regression errors of 0.021 and 0.031. Thus, this study demonstrates the feasibility and great potential of using the Deep Learning approach for fast and noninvasive assessment of collagenous tissue elastic properties from microstructural images. In this study, we developed, to our best knowledge, the first Deep Learning-based approach to estimate the elastic properties of collagenous tissues directly from noninvasive second harmonic generation images. The success of this study holds promise for the use of Machine Learning techniques to noninvasively and efficiently estimate the mechanical properties of many structure-based biological materials, and it also enables many potential applications such as serving as a quality control tool to select tissue for the manufacturing of medical devices (e.g. bioprosthetic heart valves). Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Parasitic loads in tissues of mice infected with Trypanosoma cruzi and treated with AmBisome.

Directory of Open Access Journals (Sweden)

Sabrina Cencig

2011-06-01

Full Text Available BACKGROUND: Chagas disease is one of the most important public health problems and a leading cause of cardiac failure in Latin America. The currently available drugs to treat T. cruzi infection (benznidazole and nifurtimox are effective in humans when administered during months. AmBisome (liposomal amphotericin B, already shown efficient after administration for some days in human and experimental infection with Leishmania, has been scarcely studied in T. cruzi infection. AIMS: This work investigates the effect of AmBisome treatment, administered in 6 intraperitoneal injections at various times during acute and/or chronic phases of mouse T. cruzi infection, comparing survival rates and parasitic loads in several tissues. METHODOLOGY: Quantitative PCR was used to determine parasitic DNA amounts in tissues. Immunosuppressive treatment with cyclophosphamide was used to investigate residual infection in tissues. FINDINGS: Administration of AmBisome during the acute phase of infection prevented mice from fatal issue. Parasitaemias (microscopic examination were reduced in acute phase and undetectable in chronic infection. Quantitative PCR analyses showed significant parasite load reductions in heart, liver, spleen, skeletal muscle and adipose tissues in acute as well as in chronic infection. An earlier administration of AmBisome (one day after parasite inoculation had a better effect in reducing parasite loads in spleen and liver, whereas repetition of treatment in chronic phase enhanced the parasite load reduction in heart and liver. However, whatever the treatment schedule, cyclophosphamide injections boosted infection to parasite amounts comparable to those observed in acutely infected and untreated mice. CONCLUSIONS: Though AmBisome treatment fails to completely cure mice from T. cruzi infection, it impedes mortality and reduces significantly the parasitic loads in most tissues. Such a beneficial effect, obtained by administrating it over a short

Temperature simulations in hyperthermia treatment planning of the head and neck region. Rigorous optimization of tissue properties

International Nuclear Information System (INIS)

Verhaart, Rene F.; Rijnen, Zef; Verduijn, Gerda M.; Paulides, Margarethus M.; Fortunati, Valerio; Walsum, Theo van; Veenland, Jifke F.

2014-01-01

Hyperthermia treatment planning (HTP) is used in the head and neck region (H and N) for pretreatment optimization, decision making, and real-time HTP-guided adaptive application of hyperthermia. In current clinical practice, HTP is based on power-absorption predictions, but thermal dose-effect relationships advocate its extension to temperature predictions. Exploitation of temperature simulations requires region- and temperature-specific thermal tissue properties due to the strong thermoregulatory response of H and N tissues. The purpose of our work was to develop a technique for patient group-specific optimization of thermal tissue properties based on invasively measured temperatures, and to evaluate the accuracy achievable. Data from 17 treated patients were used to optimize the perfusion and thermal conductivity values for the Pennes bioheat equation-based thermal model. A leave-one-out approach was applied to accurately assess the difference between measured and simulated temperature (∇T). The improvement in ∇T for optimized thermal property values was assessed by comparison with the ∇T for values from the literature, i.e., baseline and under thermal stress. The optimized perfusion and conductivity values of tumor, muscle, and fat led to an improvement in simulation accuracy (∇T: 2.1 ± 1.2 C) compared with the accuracy for baseline (∇T: 12.7 ± 11.1 C) or thermal stress (∇T: 4.4 ± 3.5 C) property values. The presented technique leads to patient group-specific temperature property values that effectively improve simulation accuracy for the challenging H and N region, thereby making simulations an elegant addition to invasive measurements. The rigorous leave-one-out assessment indicates that improvements in accuracy are required to rely only on temperature-based HTP in the clinic. (orig.) [de

Nanofluids with plasma treated diamond nanoparticles

International Nuclear Information System (INIS)

Yu Qingsong; Kim, Young Jo; Ma Hongbin

2008-01-01

In this study, diamond nanoparticles were plasma treated by glow discharges of methane and oxygen with an aim of improving their dispersion characteristics in a base fluid of water and enhancing the thermal conductivity of the resulting nanofluids. It was found that, after plasma treatment, stable nanofluids with improved thermal conductivity were obtained without using any stabilizing agents. With <0.15 vol % addition of plasma treated nanoparticles into water, a 20% increase in thermal conductivity was achieved and a 5%-10% increase in both fluid density and viscosity was observed

In vivo characterization of tissue thermal properties of the kidney during local hyperthermia induced by MR-guided high-intensity focused ultrasound.

Science.gov (United States)

Cornelis, François; Grenier, Nicolas; Moonen, Chrit T; Quesson, Bruno

2011-08-01

The purpose of this study was to evaluate quantitatively in vivo the tissue thermal properties during high-intensity focused ultrasound (HIFU) heating. For this purpose, a total of 52 localized sonications were performed in the kidneys of six pigs with HIFU monitored in real time by volumetric MR thermometry. The kidney perfusion was modified by modulation of the flow in the aorta by insertion of an inflatable angioplasty balloon. The resulting temperature data were analyzed using the bio-heat transfer model in order to validate the model under in vivo conditions and to estimate quantitatively the absorption (α), thermal diffusivity (D) and perfusion (w(b)) of renal tissue. An excellent correspondence was observed between the bio-heat transfer model and the experimental data. The absorption and thermal diffusivity were independent of the flow, with mean values (± standard deviation) of 20.7 ± 5.1 mm(3) K J(-1) and 0.23 ± 0.11 mm(2) s(-1), respectively, whereas the perfusion decreased significantly by 84% (p < 0.01) with arterial flow (mean values of w(b) of 0.06 ± 0.02 and 0.008 ± 0.007 mL(-1) mL s(-1)), as predicted by the model. The quantitative analysis of the volumetric temperature distribution during nondestructive HIFU sonication allows the determination of the thermal parameters, and may therefore improve the quality of the planning of noninvasive therapy with MR-guided HIFU. Copyright © 2010 John Wiley & Sons, Ltd.

Dynamics of tissue shrinkage during ablative temperature exposures

International Nuclear Information System (INIS)

Rossmann, Christian; Haemmerich, Dieter; Garrett-Mayer, Elizabeth; Rattay, Frank

2014-01-01

There is a lack of studies that examine the dynamics of heat-induced shrinkage of organ tissues. Clinical procedures such as radiofrequency ablation, microwave ablation or high-intensity focused ultrasound, use heat to treat diseases such as cancer and cardiac arrhythmia. When heat is applied to tissues, shrinkage occurs due to protein denaturation, dehydration and contraction of collagen at temperatures greater 50 °C. This is particularly relevant for image-guided procedures such as tumor ablation, where pre- and post-treatment images are compared and any changes in dimensions must be considered to avoid misinterpretations of the treatment outcome. We present data from ex vivo, isothermal shrinkage tests in porcine liver tissue, where axial changes in tissue length were recorded during 15 min of heating to temperatures between 60 and 95 °C. A mathematical model was developed to accurately describe the time and temperature-dependent shrinkage behavior. The shrinkage dynamics had the same characteristics independent of temperature; the estimated relative shrinkage, adjusted for time since death, after 15 min heating to temperatures of 60, 65, 75, 85 and 95 °C, was 12.3, 13.8, 16.6, 19.2 and 21.7%, respectively. Our results demonstrate the shrinkage dynamics of organ tissues, and suggest the importance of considering tissue shrinkage for thermal ablative treatments. (paper)

Thermal conductivity and diffusivity of biomaterials measured with self-heated thermistors

Science.gov (United States)

Valvano, J. W.; Cochran, J. R.; Diller, K. R.

1985-05-01

This paper presents an experimental method to measure the thermal conductivity and thermal diffusivity of biomaterials. Self-heated thermistor probes, inserted into the tissue of interest, are used to deliver heat as well as to monitor the rate of heat removal. An empirical calibration procedure allows accurate thermal-property measurements over a wide range of tissue temperatures. Operation of the instrument in three media with known thermal properties shows the uncertainty of measurements to be about 2%. The reproducibility is 0.5% for the thermal-conductivity measurements and 2% for the thermal-diffusivity measurements. Thermal properties were measured in dog, pig, rabbit, and human tissues. The tissues included kidney, spleen, liver, brain, heart, lung, pancreas, colon cancer, and breast cancer. Thermal properties were measured for 65 separate tissue samples at 3, 10, 17, 23, 30, 37, and 45°C. The results show that the temperature coefficient of biomaterials approximates that of water.

Thermal and molecular investigation of laser tissue welding

Science.gov (United States)

Small, Ward, IV

Despite the growing number of successful animal and human trials, the exact mechanisms of laser tissue welding remain unknown. Furthermore, the effects of laser heating on tissue on the molecular scale are not fully understood. To address these issues, a multi-front attack on both extrinsic (solder/patch mediated) and intrinsic (laser only) tissue welding was launched using two-color infrared thermometry, computer modeling, weld strength assessment, biochemical assays, and vibrational spectroscopy. The coupling of experimentally measured surface temperatures with the predictive numerical simulations provided insight into the sub surface dynamics of the laser tissue welding process. Quantification of the acute strength of the welds following the welding procedure enabled comparison among trials during an experiment, with previous experiments, and with other studies in the literature. The acute weld integrity also provided an indication of the probability of long-term success. Molecular effects induced in the tissue by laser irradiation were investigated by measuring the concentrations of specific collagen covalent crosslinks and measuring the infrared absorption spectra before and after the laser exposure. This investigation yielded results pertaining to both the methods and mechanisms of laser tissue welding. The combination of two-color infrared thermometry to obtain accurate surface temperatures free from emissivity bias and computer modeling illustrated the importance of including evaporation in the simulations, which effectively serves as an inherent cooling mechanism during laser irradiation. Moreover, the hydration state predicted by the model was useful in assessing the role of electrostatic versus covalent bonding in the fusion. These tools also helped elicit differences between dye- enhanced liquid solders and solid-matrix patches in laser-assisted tissue welding, demonstrating the significance of repeatable energy delivery. Surprisingly, covalent bonds

Thermal and molecular investigation of laser tissue welding

Energy Technology Data Exchange (ETDEWEB)

Small, W., IV

1998-06-01

Despite the growing number of successful animal and human trials, the exact mechanisms of laser tissue welding remain unknown. Furthermore, the effects of laser heating on tissue on the molecular scale are not fully understood. To address these issues, a multi-front attack oil both extrinsic (solder/patch mediated) and intrinsic (laser only) tissue welding was launched using two-color infrared thermometry, computer modeling, weld strength assessment, biochemical assays, and vibrational spectroscopy. The coupling of experimentally measured surface temperatures with the predictive numerical simulations provided insight into the sub-surface dynamics of the laser tissue welding process. Quantification of the acute strength of the welds following the welding procedure enabled comparison among trials during an experiment, with previous experiments, and with other studies in the literature. The acute weld integrity also provided an indication of tile probability of long-term success. Molecular effects induced In the tissue by laser irradiation were investigated by measuring tile concentrations of specific collagen covalent crosslinks and characterizing the Fourier-Transform infrared (FTIR) spectra before and after the laser exposure.

Heat transfer modelling of pulsed laser-tissue interaction

Science.gov (United States)

Urzova, J.; Jelinek, M.

2018-03-01

Due to their attributes, the application of medical lasers is on the rise in numerous medical fields. From a biomedical point of view, the most interesting applications are the thermal interactions and the photoablative interactions, which effectively remove tissue without excessive heat damage to the remaining tissue. The objective of this work is to create a theoretical model for heat transfer in the tissue following its interaction with the laser beam to predict heat transfer during medical laser surgery procedures. The dimensions of the ablated crater (shape and ablation depth) were determined by computed tomography imaging. COMSOL Multiphysics software was used for temperature modelling. The parameters of tissue and blood, such as density, specific heat capacity, thermal conductivity and diffusivity, were calculated from the chemical ratio. The parameters of laser-tissue interaction, such as absorption and reflection coefficients, were experimentally determined. The parameters of the laser beam were power density, repetition frequency, pulse length and spot dimensions. Heat spreading after laser interaction with tissue was captured using a Fluke thermal camera. The model was verified for adipose tissue, skeletal muscle tissue and heart muscle tissue.

Oral paracetamol and/or ibuprofen for treating pain after soft tissue injuries: Single centre double-blind, randomised controlled clinical trial.

Directory of Open Access Journals (Sweden)

Kevin K C Hung

Full Text Available Soft tissue injuries commonly present to the emergency department (ED, often with acute pain. They cause significant suffering and morbidity if not adequately treated. Paracetamol and ibuprofen are commonly used analgesics, but it remains unknown if either one or the combination of both is superior for pain control.To investigate the analgesic effect of paracetamol, ibuprofen and the combination of both in the treatment of soft tissue injury in an ED, and the side effect profile of these drugs.Double-blind, double dummy, placebo-controlled randomised controlled trial. 782 adult patients presenting with soft tissue injury without obvious fractures attending the ED of a university hospital in the New Territories of Hong Kong were recruited. Patients were randomised using a random number table into three parallel arms of paracetamol only, ibuprofen only and a combination of paracetamol and ibuprofen in a 1:1:1 ratio. The primary outcome measure was pain score at rest and on activity in the first 2 hours and first 3 days. Data was analysed on an intention to treat basis.There was no statistically significant difference in pain score in the initial two hours between the three groups, and no clinically significant difference in pain score in the first three days.There was no difference in analgesic effects or side effects observed using oral paracetamol, ibuprofen or a combination of both in patients with mild to moderate pain after soft tissue injuries attending the ED.The study is registered with ClinicalTrials.gov (no. NCT00528658.

Oral paracetamol and/or ibuprofen for treating pain after soft tissue injuries: Single centre double-blind, randomised controlled clinical trial.

Science.gov (United States)

Hung, Kevin K C; Graham, Colin A; Lo, Ronson S L; Leung, Yuk Ki; Leung, Ling Yan; Man, S Y; Woo, W K; Cattermole, Giles N; Rainer, Timothy H

2018-01-01

Soft tissue injuries commonly present to the emergency department (ED), often with acute pain. They cause significant suffering and morbidity if not adequately treated. Paracetamol and ibuprofen are commonly used analgesics, but it remains unknown if either one or the combination of both is superior for pain control. To investigate the analgesic effect of paracetamol, ibuprofen and the combination of both in the treatment of soft tissue injury in an ED, and the side effect profile of these drugs. Double-blind, double dummy, placebo-controlled randomised controlled trial. 782 adult patients presenting with soft tissue injury without obvious fractures attending the ED of a university hospital in the New Territories of Hong Kong were recruited. Patients were randomised using a random number table into three parallel arms of paracetamol only, ibuprofen only and a combination of paracetamol and ibuprofen in a 1:1:1 ratio. The primary outcome measure was pain score at rest and on activity in the first 2 hours and first 3 days. Data was analysed on an intention to treat basis. There was no statistically significant difference in pain score in the initial two hours between the three groups, and no clinically significant difference in pain score in the first three days. There was no difference in analgesic effects or side effects observed using oral paracetamol, ibuprofen or a combination of both in patients with mild to moderate pain after soft tissue injuries attending the ED. The study is registered with ClinicalTrials.gov (no. NCT00528658).

Optoacoustic detection of thermal lesions

Science.gov (United States)

Arsenault, Michel G.; Kolios, Michael C.; Whelan, William M.

2009-02-01

Minimally invasive thermal therapy is being investigated as an alternative cancer treatment. It involves heating tissues to greater than 55°C over a period of a few minutes, which results in tissue coagulation. Optoacoustic (OA) imaging is a new imaging technique that involves exposing tissues to pulsed light and detecting the acoustic waves that are generated. In this study, adult bovine liver tissue samples were heated using continuous wave laser energy for various times, then scanned using an optoacoustic imaging system. Large optoacoustic signal variability was observed in the native tissue prior to heating. OA signal amplitude increased with maximum tissue temperature achieved, characterized by a correlation coefficient of 0.63. In this study we show that there are detectable changes in optoacoustic signal strength that arise from tissue coagulation, which demonstrates the potential of optoacoustic technology for the monitoring of thermal therapy delivery.

High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

Science.gov (United States)

Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

2011-07-01

CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at the roof of the pulp chamber on teeth that were occlusally ablated using a rapidly-scanned CO2 laser operating at 9.3 μm with a pulse duration of 10 to 15 μs and repetition rate of 300 Hz over a 2 min time course. The adhesion strength of laser treated enamel and dentin surfaces was measured for various laser scanning parameters with and without post-ablation acid etching using the single-plane shear test. The mechanical strength of laser-ablated dentin surfaces were determined via the four-point bend test and compared to control samples prepared with 320 grit wet sand paper to simulate conventional preparations. Thermocouple measurements indicated that the temperature remained below ambient temperature if water-cooling was used. There was no discoloration of either dentin or enamel laser treated surfaces, the surfaces were uniformly ablated, and there were no cracks visible. Four-point bend tests yielded mean mechanical strengths of 18.2 N (s.d. = 4.6) for ablated dentin and 18.1 N (s.d. = 2.7) for control (p > 0.05). Shear tests yielded mean bond strengths approaching 30 MPa for both enamel and dentin under certain irradiation conditions. These values were slightly lower than nonirradiated acid-etched control samples. Additional studies are needed to determine if the slightly lower bond strength than the acid-etched control samples is clinically significant. These measurements demonstrate that enamel and dentin surfaces can be rapidly ablated by CO2 lasers with minimal

A new bioheat equation and its application to peripheral tissue and whole limb heat transfer

International Nuclear Information System (INIS)

Weinbaum, S.

1987-01-01

Much of the mathematical modeling of heat transfer in perfused tissue over the past three decades has been based on the Pennes bioheat equation. This equation assumes that blood at the local arterial supply temperature reaches the capillaries where the primary thermal equilibration occurs because of the large surface area available for heat exchange. While this argument is correct for gas, water and solute transport, recent theoretical and experimental studies have shown that virtually no heat exchange occurs in vessels under 100 μm and that the primary mechanism for microvascular heat exchange is the imperfect heat exchange between the larger paired countercurrent microvessels that occur 3 to 6 generations prior to the capillaries. A new fundamental bioheat equations has been derived to describe this heat transfer mechanism. This equation contains a basic new expression for the thermal conductivity of perfused tissue which depends on the geometry and flow in the largest microvessels of the local tissue element and the direction of the vessels relative to the local tissue temperature gradient. Although the new equation appears to be complicated, it is shown that it can be applied with relative ease to a host of problems previously treated by the Pennes equation

Temperature dynamics of soft tissues during diode laser cutting by different types of fiber opto-thermal converters

Science.gov (United States)

Belikov, Andrey V.; Skrypnik, Alexei V.; Smirnov, Sergey N.; Semyashkina, Yulia V.

2017-03-01

The results of in vitro study of the soft tissue temperature dynamics during 980 nm diode laser cutting by different types (CLEAR, FILM, VOLUMETRIC) of fiber opto-thermal converters (FOTC) are presented. It was found that the use of CLEAR fiber end (tip) at the laser power below 8.5 W doesn't lead to the soft tissue (chicken meat) destruction. The chicken meat destruction (cutting) begins when irradiated by 8.5 W laser radiation for approximately 9.0 s. At the power of 9.0 W this time decreases up to 7.0 s, at 9.5 W - to 6.0 s, at 10.0 W - to 3.5 s. The moment of soft tissue cutting start correlates with the moment of black layer (absorber) formation at the fiber end and appearance of visually identifiable laser cut walls on the photos; the temperature in this case rapidly increases up to 850 °C. It was determined that the FILM FOTC begins to cut the soft tissue immediately after exposure of laser radiation with power of 4.0 W, the temperature in this case reaches 900 °C. It was determined that the VOLUMETRIC FOTC begins to cut the tissue immediately after exposure at the power of 1.0 W, the temperature in this case reaches 600 °C. VOLUMETRIC FOTC can produce more effective cuts of the soft tissue at the laser power of 4.0 W, in this case, the temperature is above 1200 °C.

Long-term stability of soft tissue changes in anterior open bite adults treated with zygomatic miniplate-anchored maxillary posterior intrusion.

Science.gov (United States)

Marzouk, Eiman S; Kassem, Hassan E

2018-03-01

To evaluate soft tissue changes and their long-term stability in skeletal anterior open bite adults treated by maxillary posterior teeth intrusion using zygomatic miniplates and premolar extractions. Lateral cephalograms of 26 patients were taken at pretreatment (T1), posttreatment (T2), 1 year posttreatment (T3), and 4 years posttreatment (T4). At the end of treatment, the soft tissue facial height and profile convexity were reduced. The lips increased in length and thickness, with backward movement of the upper lip and forward movement of the lower lip. The total relapse rate ranged from 20.2% to 31.1%. At 4 years posttreatment, 68.9% to 79.8% of the soft tissue treatment effects were stable. The changes in the first year posttreatment accounted for approximately 70% of the total relapse. Soft tissue changes following maxillary posterior teeth intrusion with zygomatic miniplates and premolar extractions appear to be stable 4 years after treatment.

Percutaneous Soft Tissue Release for Treating Chronic Recurrent Myofascial Pain Associated with Lateral Epicondylitis: 6 Case Studies

Science.gov (United States)

Lin, Ming-Ta; Chou, Li-Wei; Chen, Hsin-Shui; Kao, Mu-Jung

2012-01-01

Objective. The purpose of this pilot study is to investigate the effectiveness of the percutaneous soft tissue release for the treatment of recurrent myofascial pain in the forearm due to recurrent lateral epicondylitis. Methods. Six patients with chronic recurrent pain in the forearm with myofascial trigger points (MTrPs) due to chronic lateral epicondylitis were treated with percutaneous soft tissue release of Lin's technique. Pain intensity (measured with a numerical pain rating scale), pressure pain threshold (measured with a pressure algometer), and grasping strength (measured with a hand dynamometer) were assessed before, immediately after, and 3 months and 12 months after the treatment. Results. For every individual case, the pain intensity was significantly reduced (P lateral epicondylitis to avoid recurrence, if other treatment, such as oral anti-inflammatory medicine, physical therapy, or local steroid injection, cannot control the recurrent pain. PMID:23243428

Structural, thermal, optical properties and cytotoxicity of PMMA/ZnO fibers and films: Potential application in tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Balen, Rodrigo; Vidotto da Costa, Wilian; Lara Andrade, Jéssica de; Piai, Juliana Francis [Programa de Pós-Graduação em Química, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900, Zona Sete, Maringá, PR (Brazil); Muniz, Edvani Curti [Programa de Pós-Graduação em Química, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900, Zona Sete, Maringá, PR (Brazil); Programa de Pós-Graduação em Biotecnologia Aplicada à Agricultura, Universidade Paranaense (UNIPAR), 87502-210, Umuarama, PR (Brazil); Programa de Pós- Graduação em Ciências de Materiais & Engenharia, Universidade Tecnológica Federal do Paraná (UTFPR-LD), 86036-370, Londrina, PR (Brazil); Companhoni, Mychelle Vianna; Nakamura, Tânia Ueda [Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900, Zona Sete, Maringá, PR (Brazil); and others

2016-11-01

Highlights: • Films and fibers of PMMA/ZnO nanocomposite were prepared. • ZnO NPs incorporated into PMMA fibers reduces their diameter and beads presence. • PMMA films containing ZnO exhibit higher thermal stability than pure polymer. • PMMA/ZnO nanocomposites show improved optical properties compared to pure polymer. • PMMA/ZnO shows potential for applications in tissue engineering. - Abstract: Films and fibers of PMMA/ZnO nanocomposites (100/0, 99/01, 97/03, 95/05, 90/10, and 85/15 wt.%) were produced by casting and electrospinning, respectively. Their structural, thermal, and optical properties were investigated by XRD, SEM, TGA, PAS, and PL. The incorporation of ZnO NPs reduced the diameter of PMMA fibers and the presence of beads. The surfaces of the fibers exhibited greater hydrophobicity, compared to the films, with contact angles of around 120° and 94°, respectively. PMMA films containing ZnO exhibited higher thermal stability than the pure polymer, while the corresponding fibers did not show any changes in thermal stability. The dispersion of the ZnO NPs at the surface and in the bulk of the nanocomposites appeared to be relatively homogeneous. ZnO improved the optical properties of the PMMA, with an intense absorption band near 370 nm observed for all the nanocomposites, which also exhibited luminescence with emission in the near-UV region, both attributed to ZnO. Biological tests demonstrated that fibers and films with up to 1% of ZnO exhibited good performance in the proliferation of fibroblast cells, indicating their potential for applications in tissue engineering. The fibers provided higher cell viability than the films, presumably due to their greater surface area and/or more suitable surface morphology. Nanocomposites with 15% ZnO inhibited cell proliferation, due to the cytotoxicity of the ZnO NPs. Although several applications of PMMA have been suggested by biomedical researchers, until now there have been no reports on the specific

Structural, thermal, optical properties and cytotoxicity of PMMA/ZnO fibers and films: Potential application in tissue engineering

International Nuclear Information System (INIS)

Balen, Rodrigo; Vidotto da Costa, Wilian; Lara Andrade, Jéssica de; Piai, Juliana Francis; Muniz, Edvani Curti; Companhoni, Mychelle Vianna; Nakamura, Tânia Ueda

2016-01-01

Highlights: • Films and fibers of PMMA/ZnO nanocomposite were prepared. • ZnO NPs incorporated into PMMA fibers reduces their diameter and beads presence. • PMMA films containing ZnO exhibit higher thermal stability than pure polymer. • PMMA/ZnO nanocomposites show improved optical properties compared to pure polymer. • PMMA/ZnO shows potential for applications in tissue engineering. - Abstract: Films and fibers of PMMA/ZnO nanocomposites (100/0, 99/01, 97/03, 95/05, 90/10, and 85/15 wt.%) were produced by casting and electrospinning, respectively. Their structural, thermal, and optical properties were investigated by XRD, SEM, TGA, PAS, and PL. The incorporation of ZnO NPs reduced the diameter of PMMA fibers and the presence of beads. The surfaces of the fibers exhibited greater hydrophobicity, compared to the films, with contact angles of around 120° and 94°, respectively. PMMA films containing ZnO exhibited higher thermal stability than the pure polymer, while the corresponding fibers did not show any changes in thermal stability. The dispersion of the ZnO NPs at the surface and in the bulk of the nanocomposites appeared to be relatively homogeneous. ZnO improved the optical properties of the PMMA, with an intense absorption band near 370 nm observed for all the nanocomposites, which also exhibited luminescence with emission in the near-UV region, both attributed to ZnO. Biological tests demonstrated that fibers and films with up to 1% of ZnO exhibited good performance in the proliferation of fibroblast cells, indicating their potential for applications in tissue engineering. The fibers provided higher cell viability than the films, presumably due to their greater surface area and/or more suitable surface morphology. Nanocomposites with 15% ZnO inhibited cell proliferation, due to the cytotoxicity of the ZnO NPs. Although several applications of PMMA have been suggested by biomedical researchers, until now there have been no reports on the specific

Studies on mechanical, thermal and dynamic mechanical properties of untreated (raw) and treated coconut sheath fiber reinforced epoxy composites

International Nuclear Information System (INIS)

Suresh Kumar, S.M.; Duraibabu, D.; Subramanian, K.

2014-01-01

Highlights: • UTCSE and TCSE composites have been fabricated by compression molding technique. • The prepared specimens were characterized by FTIR, DMA, TGA and SEM techniques. • TCSE composite showed higher mechanical properties compared to UTCSE composite. • DMA showed that TCSE composite exhibited higher storage modulus than UTCSE composite. • TCSE composite showed higher thermal stability than UTCSE composite. - Abstract: The untreated (raw) coconut sheath fiber reinforced epoxy (UTCSE) composite and treated coconut sheath fiber reinforced epoxy (TCSE) composite have been fabricated using hand layup followed by compression molding technique. The prepared specimens were characterized by Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques. The prepared specimens are cut as per ASTM Standards to measure tensile, flexural and impact strengths by using universal testing machine and izod impact tester respectively. The treated coconut sheath fiber reinforced epoxy composite (TCSE) posses higher mechanical strength and thermal stability compared to untreated (raw) coconut sheath fiber reinforced epoxy composite (UTCSE). In the SEM fracture analysis, TCSE composite showed better fiber–matrix bonding and absence of voids compared to UTCSE composite

Localized Ocular Adnexal Mucosa-Associated Lymphoid Tissue Lymphoma Treated With Radiation Therapy: A Long-Term Outcome in 86 Patients With 104 Treated Eyes

Energy Technology Data Exchange (ETDEWEB)

Harada, Ken, E-mail: keharada@ncc.go.jp [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Murakami, Naoya; Kitaguchi, Mayuka; Sekii, Shuhei; Takahashi, Kana; Yoshio, Kotaro; Inaba, Koji; Morota, Madoka; Ito, Yoshinori; Sumi, Minako [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Suzuki, Shigenobu [Department of Ophthalmic Oncology, National Cancer Center Hospital, Tokyo (Japan); Tobinai, Kensei [Department of Hematologic Oncology, National Cancer Center Hospital, Tokyo (Japan); Uno, Takashi [Department of Radiology, Chiba University School of Medicine, Chiba (Japan); Itami, Jun [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)

2014-03-01

Purpose: To evaluate the natural history, behavior of progression, prognostic factors, and treatment-related adverse effects of primary ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma (POAML). Methods and Materials: Eighty-six patients with histologically proven stage I POAML treated with radiation therapy at National Cancer Center Hospital, Tokyo between 1990 and 2010 were retrospectively reviewed. The median age was 56 years (range, 18-85 years). The median dose administered was 30 Gy (range, 30-46 Gy). Seventy-seven patients (90%) were treated by radiation therapy alone. Results: The median follow-up duration was 9 years (range, 0.9-22 years). The 5- and 10-year overall survival (OS) rates were 97.6% and 93.5%, respectively, and no patients died of lymphoma. Patients with tumor sizes ≥4 cm showed a greater risk of contralateral relapse (P=.012). Six patients with contralateral relapse were seen and treated by radiation therapy alone, and all the lesions were controlled well, with follow-up times of 3 to 12 years. There was 1 case of local relapse after radiation therapy alone, and 3 cases of relapse occurred in a distant site. Cataracts developed in 36 of the 65 eyes treated without lens shielding and in 12 of the 39 patients with lens shielding (P=.037). Conclusions: The majority of patients with POAML showed behavior consistent with that of localized, indolent diseases. Thirty gray of local irradiation seems to be quite effective. The initial bilateral involvement and contralateral orbital relapses can be also controlled with radiation therapy alone. Lens shielding reduces the risk of cataract.

Localized Ocular Adnexal Mucosa-Associated Lymphoid Tissue Lymphoma Treated With Radiation Therapy: A Long-Term Outcome in 86 Patients With 104 Treated Eyes

International Nuclear Information System (INIS)

Harada, Ken; Murakami, Naoya; Kitaguchi, Mayuka; Sekii, Shuhei; Takahashi, Kana; Yoshio, Kotaro; Inaba, Koji; Morota, Madoka; Ito, Yoshinori; Sumi, Minako; Suzuki, Shigenobu; Tobinai, Kensei; Uno, Takashi; Itami, Jun

2014-01-01

Purpose: To evaluate the natural history, behavior of progression, prognostic factors, and treatment-related adverse effects of primary ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma (POAML). Methods and Materials: Eighty-six patients with histologically proven stage I POAML treated with radiation therapy at National Cancer Center Hospital, Tokyo between 1990 and 2010 were retrospectively reviewed. The median age was 56 years (range, 18-85 years). The median dose administered was 30 Gy (range, 30-46 Gy). Seventy-seven patients (90%) were treated by radiation therapy alone. Results: The median follow-up duration was 9 years (range, 0.9-22 years). The 5- and 10-year overall survival (OS) rates were 97.6% and 93.5%, respectively, and no patients died of lymphoma. Patients with tumor sizes ≥4 cm showed a greater risk of contralateral relapse (P=.012). Six patients with contralateral relapse were seen and treated by radiation therapy alone, and all the lesions were controlled well, with follow-up times of 3 to 12 years. There was 1 case of local relapse after radiation therapy alone, and 3 cases of relapse occurred in a distant site. Cataracts developed in 36 of the 65 eyes treated without lens shielding and in 12 of the 39 patients with lens shielding (P=.037). Conclusions: The majority of patients with POAML showed behavior consistent with that of localized, indolent diseases. Thirty gray of local irradiation seems to be quite effective. The initial bilateral involvement and contralateral orbital relapses can be also controlled with radiation therapy alone. Lens shielding reduces the risk of cataract

Biothermomechanical behavior of skin tissue

Institute of Scientific and Technical Information of China (English)

F.Xu; T.J.Lu; K.A.Seffen

2008-01-01

Advances in laser,microwave and similar tech nologies have led to recent developments of thermal treatments involving skin tissue.The effectiveness of these treatments is governed by the coupled thermal,mechanical,biological and neural responses of the affected tissue:a favorable interaction results in a procedure with relatively little pain and no lasting side effects.Currently,even though each behavioral facet is to a certain extent established and understood,none exists to date in the interdisciplinarv area.A highly interdisciplinary approach is required for studying the biothermomechanical behavior of skin,involving bioheat transfer.biomechanics and physiology.A comprehensive literature review penrtinent to the subject is presented in this paper,covering four subject areas:(a)skin structure,(b)skin bioheat transfer and thermal damage,(c)skin biomechanics,and(d)skin biothermomechanics.The major problems,issues,and topics for further studies are also outlined.This review finds that significant advances in each of these aspects have been achieved in recent years.Although focus is placed upon the biothermomechanical behavior of skin tissue,the fundamental concepts and methodologies reviewed in this paper may also be applicable for studying other soft tissues.

Morphology and gas sensing properties of as-deposited and thermally treated doped thin SnO{sub x} layers

Energy Technology Data Exchange (ETDEWEB)

Georgieva, B; Pirov, J; Podolesheva, I [Acad. J. Malinowski Central Laboratory of Photoprocesses, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl.109, 1113 Sofia (Bulgaria); Nihtianova, D, E-mail: biliana@clf.bas.b [Central Laboratory of Mineralogy and Crystallography, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl.107, 1113 Sofia (Bulgaria)

2010-04-01

Thin layers intended for gas sensors are prepared by vacuum co-evaporation of TeO{sub 2} and Sn. The as-deposited layers consist of a nanosized oxide matrix and finely dispersed dopants (Te, Sn, TeO{sub 2} or SnTe, depending on the atomic ratio R{sub Sn/Te}). In order to improve the characteristics of the layers they are additionally doped with platinum. The gas sensing properties are strongly dependent on the atomic ratio R{sub Sn/Te}, as well as on the structure, composition and surface morphology. The as-deposited layers with R{sub Sn/Te} 0.8 are highly sensitive humidity sensors working at room temperature. Thermally treated Pt-doped layers with R{sub Sn/Te} 2.3 are promising as ethanol sensors. With the aim of obtaining more detailed knowledge about the surface morphology, structure and composition of layers sensitive to different environments, various techniques -TEM, SAED, SEM, EDS in SEM and white light interferometry (WLI), are applied. It is shown that all layers with 1.0 > R{sub Sn/Te} > 2, as-deposited and thermally treated, exhibit a columnar structure and a very smooth surface along with the nanograined matrix. The thermal treatment causes changes in the structure and composition of the layers. The ethanol-sensitive layers consist of nanosized polycrystalline phases of SnO{sub 2}, Sn{sub 2}O{sub 3}, Sn{sub 3}O{sub 4} and TeO{sub 2}. This knowledge could help us understand better the behaviour and govern the characteristics of layers obtained by co-evaporation of Sn and TeO{sub 2}.

Integrated fiber optical and thermal sensor for noninvasive monitoring of blood and human tissue

Science.gov (United States)

Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Schiffner, Gerhard

2007-05-01

A novel concept of noninvasive monitoring of human tissue and blood based on optical diffuse reflective spectroscopy combined with metabolic heat measurements has been under development. A compact integrated fiber optical and thermal sensor has been developed. The idea of the method was to evaluate by optical spectroscopy haemoglobin and derivative concentrations and supplement with data associated with the oxidative metabolism of glucose. Body heat generated by glucose oxidation is based on the balance of capillary glucose and oxygen supply to the cells. The variation in glucose concentration is followed also by a difference from a distance (or depth) of scattered through the body radiation. So, blood glucose can be estimated by measuring the body heat and the oxygen supply. The sensor pickup contains of halogen lamp and LEDs combined with fiber optical bundle to deliver optical radiation inside and through the patient body, optical and thermal detectors. Fiber optical probe allows diffuse scattering measurement down to a depth of 2.5 mm in the skin including vascular system, which contributes to the control of the body temperature. The sensor pickup measures thermal generation, heat balance, blood flow rate, haemoglobin and derivative concentrations, environmental conditions. Multivariate statistical analysis was applied to convert various signals from the sensor pickup into physicochemical variables. By comparing the values from the noninvasive measurement with the venous plasma result, analytical functions for patient were obtained. Cluster analysis of patient groups was used to simplify a calibration procedure. Clinical testing of developed sensor is being performed.

A functionalizable reverse thermal gel based on a polyurethane/PEG block copolymer

Science.gov (United States)

Park, Daewon; Wu, Wei; Wang, Yadong

2010-01-01

Injectable reverse thermal gels have great potentials as biomaterials for tissue engineering and drug delivery. However, most existing gels lack functional groups that can be modified with biomolecules that can guide cell/material interactions. We created an amine-functionalized ABA block copolymer, poly(ethylene glycol)-poly(serinol hexamethylene urethane), or ESHU. This reverse thermal gel consists of a hydrophobic block (B): poly(serinol hexamethylene urethane) and a hydrophilic block (A): poly(ethylene glycol). The polymer was characterized by GPC, FTIR and 1H FTNMR. Rheological study demonstrated that ESHU solution in phosphate-buffered saline initiated phase transition at 32°C and reached maximum elastic modulus at 37°C. The in vitro degradation tests performed in PBS and cholesterol esterase solutions revealed that the polymer was hydrolyzable and the presence of cholesterol esterase greatly accelerated the hydrolysis. The in vitro cytotoxicity tests carried out using baboon smooth muscle cells demonstrated that ESHU had good cytocompatibility with cell viability indistinguishable from tissue culture treated polystyrene. Subcutaneous implantation in rats revealed well tolerated accurate inflammatory response with moderate ED-1 positive macrophages in the early stages, which largely resolved 4 weeks post-implantation. We functionalized ESHU with a hexapeptide, Ile-Lys-Val-Ala-Val-Ser (IKVAVS), which gelled rapidly at body temperature. We expect this new platform of functionalizable reverse thermal gels to provide versatile biomaterials in tissue engineering and regenerative medicine. PMID:20937526

Evaluation of laser radiation regimes at thermal tissue destruction

Science.gov (United States)

Ivanov, Anatoly; Kazaryan, Mishik A.; Molodykh, E. I.; Shchetinkina, T. A.

1996-01-01

The existing methods of laser destruction of biotissues, widely spread in surgery and coagulation action, are based on local heat emission in the tissues after light absorption. Here we present the results of the simulation of tissues heat destruction, taking into account the influence of blood and lymph circulation on the processes of heat transfer. The problem is adapted to the case of liver tissue with tumor. A liver is considered as a capillary-porous body with internal blood circulation. Heatconductivity and tissue-blood heat transfer are considered. Heat action is assumed to be implemented with contact laser scalpel. The mathematical model consists of two inhomogeneous nonlinear equations of heatconductivity with spherical symmetry. Nonstationary temperature fields of tissue and blood are determined and the main parameters are: (1) coefficients of heatconductivity and capacitance of blood and tissue, (2) blood and tissue density, (3) total metabolic energy, (4) volume coefficient accounting for heat-exchange between tissue and blood, and (5) blood circulation velocity. The power of laser radiation was taken into account in boundary conditions set for the center of coagulated tissue volume. We also took into account the process connected with changing of substance phase (vaporization). The original computer programs allow one to solve the problem varying in a wide range of the main parameters. Reasonable agreement was found between the calculation results and the experimental data for operations on microsamples and on test animals. It was demonstrated, in particular, that liver tissue coagulation regime is achieved at 10 W laser power during 25 s. The coagulation radius of 0.7 cm with the given tumor radius of 0.5 cm corresponds to the real clinical situation in case of metastasis liver affection.

Biocompatibility of plasma-treated poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanofiber mats modified by silk fibroin for bone tissue regeneration

Energy Technology Data Exchange (ETDEWEB)

Unalan, Irem [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Dokuz Eylul University, Izmir (Turkey); Colpankan, Oylum [Metallurgical and Materials Engineering Department, Faculty of Engineering, Dokuz Eylul University, Izmir (Turkey); Albayrak, Aylin Ziylan, E-mail: aylin.albayrak@deu.edu.tr [Metallurgical and Materials Engineering Department, Faculty of Engineering, Dokuz Eylul University, Izmir (Turkey); Gorgun, Cansu [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Ege University, Izmir (Turkey); Urkmez, Aylin Sendemir [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Ege University, Izmir (Turkey); Bioengineering Department, Faculty of Engineering, Ege University, Izmir (Turkey)

2016-11-01

The objective of this study was to produce biocompatible plasma-treated and silk-fibroin (SF) modified poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofiber mats. The mats were plasma-treated using O{sub 2} or N{sub 2} gas to increase their hydrophilicity followed by SF immobilization for the improvement of biocompatibility. Contact angle measurements and SEM showed increased hydrophilicity and no disturbed morphology, respectively. Cell proliferation assay revealed that SF modification together with N{sub 2} plasma (PS/N{sub 2}) promoted higher osteoblastic (SaOs-2) cell viability. Although, O{sub 2} plasma triggered more mineral formation on the mats, it showed poor cell viability. Consequently, the PS/N{sub 2} nanofiber mats would be a potential candidate for bone tissue engineering applications. - Highlights: • N{sub 2}-plasma treated and silk fibroin modified mats do not show hydrophobic recovery. • Biomineralization is better on O{sub 2}-plasma treated and silk fibroin modified mats. • SaOS-2 cells like to proliferate on N{sub 2}-plasma treated surfaces.

Treat upgrade fuel fabrication

International Nuclear Information System (INIS)

Davidson, K.V.; Schell, D.H.

1979-01-01

An extrusion and thermal treatment process was developed to produce graphite fuel rods containing a dispersion of enriched UO 2 . These rods will be used in an upgraded version of the Transient Reactor Test Facility (TREAT). The improved fuel provides a higher graphite matrix density, better fuel dispersion and higher thermal capabilities than the existing fuel

FEM modeling and histological analyses on thermal damage induced in facial skin resurfacing procedure with different CO2 laser pulse duration

Science.gov (United States)

Rossi, Francesca; Zingoni, Tiziano; Di Cicco, Emiliano; Manetti, Leonardo; Pini, Roberto; Fortuna, Damiano

2011-07-01

Laser light is nowadays routinely used in the aesthetic treatments of facial skin, such as in laser rejuvenation, scar removal etc. The induced thermal damage may be varied by setting different laser parameters, in order to obtain a particular aesthetic result. In this work, it is proposed a theoretical study on the induced thermal damage in the deep tissue, by considering different laser pulse duration. The study is based on the Finite Element Method (FEM): a bidimensional model of the facial skin is depicted in axial symmetry, considering the different skin structures and their different optical and thermal parameters; the conversion of laser light into thermal energy is modeled by the bio-heat equation. The light source is a CO2 laser, with different pulse durations. The model enabled to study the thermal damage induced into the skin, by calculating the Arrhenius integral. The post-processing results enabled to study in space and time the temperature dynamics induced in the facial skin, to study the eventual cumulative effects of subsequent laser pulses and to optimize the procedure for applications in dermatological surgery. The calculated data where then validated in an experimental measurement session, performed in a sheep animal model. Histological analyses were performed on the treated tissues, evidencing the spatial distribution and the entity of the thermal damage in the collageneous tissue. Modeling and experimental results were in good agreement, and they were used to design a new optimized laser based skin resurfacing procedure.

Structure and wettability property of the growth and nucleation surfaces of thermally treated freestanding CVD diamond films

Science.gov (United States)

Pei, Xiaoqiang; Cheng, Shaoheng; Ma, Yibo; Wu, Danfeng; Liu, Junsong; Wang, Qiliang; Yang, Yizhou; Li, Hongdong

2015-08-01

This paper reports the surface features and wettability properties of the (1 0 0)-textured freestanding chemical vapor deposited (CVD) diamond films after thermal exposure in air at high temperature. Thermal oxidation at proper conditions eliminates selectively nanodiamonds and non-diamond carbons in the films. The growth side of the films contains (1 0 0)-oriented micrometer-sized columns, while its nucleation side is formed of nano-sized tips. The examined wettability properties of the as-treated diamond films reveal a hydrophilicity and superhydrophilicity on the growth surface and nucleation surface, respectively, which is determined by oxygen termination and geometry structure of the surface. When the surface termination is hydrogenated, the wettability of nucleation side converted from superhydrophilicity to high hydrophobicity, while the hydrophilicity of the growth side does not change significantly. The findings open a possibility for realizing freestanding diamond films having not only novel surface structures but also multifunction applications, especially proposed on the selected growth side or nucleation side in one product.

Volatility and leachability of heavy metals and radionuclides in thermally treated HEPA filter media generated from nuclear facilities

International Nuclear Information System (INIS)

Yoon, In-Ho; Choi, Wang-Kyu; Lee, Suk-Chol; Min, Byung-Youn; Yang, Hee-Chul; Lee, Kune-Woo

2012-01-01

Highlights: ► Thermally treated HEPA filter media was transformed into glassy bulk materials. ► Main radionuclide and heavy metal were Cs-137 and Zn. ► Cs and Zn were transformed into stable form without volatilization and leaching. ► The proposed technique is simple and energy efficient procedure. - Abstract: The purpose of the present study was to apply thermal treatments to reduce the volume of HEPA filter media and to investigate the volatility and leachability of heavy metals and radionuclides during thermal treatment. HEPA filter media were transformed to glassy bulk material by thermal treatment at 900 °C for 2 h. The most abundant heavy metal in the HEPA filter media was Zn, followed by Sr, Pb and Cr, and the main radionuclide was Cs-137. The volatility tests showed that the heavy metals and radionuclides in radioactive HEPA filter media were not volatilized during the thermal treatment. PCT tests indicated that the leachability of heavy metals and radionuclides was relatively low compared to those of other glasses. XRD results showed that Zn and Cs reacted with HEPA filter media and were transformed into crystalline willemite (ZnO·SiO 2 ) and pollucite (Cs 2 OAl 2 O 3 4SiO 2 ), which are not volatile or leachable. The proposed technique for the volume reduction and transformation of radioactive HEPA filter media into glassy bulk material is a simple and energy efficient procedure without additives that can be performed at relatively low temperature compared with conventional vitrification process.

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

International Nuclear Information System (INIS)

Pérez, Juan J.; Pérez-Cajaraville, Juan J.; Muñoz, Víctor; Berjano, Enrique

2014-01-01

Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m −1 ) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

Energy Technology Data Exchange (ETDEWEB)

Pérez, Juan J. [Instituto de Investigación Interuniversitario en Bioingeniería y Tecnología Orientada al Ser Humano, Universitat Politècnica de València, Valencia 46022 (Spain); Pérez-Cajaraville, Juan J. [Pain Unit and Department of Anesthesia and Critical Care, Clínica Universidad de Navarra, University of Navarra, Pamplona 31008 (Spain); Muñoz, Víctor [Neurotherm Spain, Barcelona 08303 (Spain); Berjano, Enrique, E-mail: eberjano@eln.upv.es [Biomedical Synergy, Electronic Engineering Department, Universitat Politècnica de València 46022 (Spain)

2014-07-15

Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m{sup −1}) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of

Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief.

Science.gov (United States)

Pérez, Juan J; Pérez-Cajaraville, Juan J; Muñoz, Víctor; Berjano, Enrique

2014-07-01

Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a "strip lesion" to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m(-1)) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal damage zone dimension.

Processing of baby food using pressure-assisted thermal sterilization (PATS) and comparison with thermal treatment

Science.gov (United States)

Wang, Yubin; Ismail, Marliya; Farid, Mohammed

2017-10-01

Currently baby food is sterilized using retort processing that gives an extended shelf life. However, this type of heat processing leads to reduction of organoleptic and nutrition value. Alternatively, the combination of pressure and heat could be used to achieve sterilization at reduced temperatures. This study investigates the potential of pressure-assisted thermal sterilization (PATS) technology for baby food sterilization. Here, baby food (apple puree), inoculated with Bacillus subtilis spores was treated using PATS at different operating temperatures, pressures and times and was compared with thermal only treatment. The results revealed that the decimal reduction time of B. subtilis in PATS treatment was lower than that of thermal only treatment. At a similar spore inactivation, the retention of ascorbic acid of PATS-treated sample was higher than that of thermally treated sample. The results indicated that PATS could be a potential technology for baby food processing while minimizing quality deterioration.

Late bone and soft tissue sequelae of childhood radiotherapy. Relevance of treatment age and radiation dose in 146 children treated between 1970 and 1997

Energy Technology Data Exchange (ETDEWEB)

Doerr, W. [Technical Univ. of Dresden (Germany). Dept. of Radiotherapy and Radiation Oncology; Medical University / AKH Vienna (Austria). Dept. of Radiation Oncology; Kallfels, S. [Technical Univ. of Dresden (Germany). Dept. of Radiotherapy and Radiation Oncology; Kinder- und Jugendmedizin, Chemnitz [Germany; Herrmann, T. [Technical Univ. of Dresden (Germany). Dept. of Radiotherapy and Radiation Oncology

2013-07-15

Purpose: The present retrospective study was initiated to characterize the effect of oncological treatments in children and adolescents on bone and soft tissues, and to assess their dependence on radiation dose and age at exposure. Patients and methods: The study included 146 patients treated between 1970 and 1997. All patients received external beam radiotherapy to the trunk or extremities, but no cranial irradiation. Median age at treatment was 8.8 years. Patients were screened at 18 years (median time interval since treatment 9.2 years, range 0.9-17.7 years) for pathological changes in the skeletal system and soft tissues (scoliosis, kyphosis, bony hypoplasia, soft tissue defects, asymmetries), which were classified as minor/moderate (grade 1) or substantial (grade 2). Results: Pathological findings were recorded in 75/146 patients (51 %). These were scored as minor in 44 (59 %) and substantial in 31 patients (41 %). Most pathological changes occurred in children treated under the age of 6 years. At 6 years and older, only doses > 35 Gy caused an effect, and no substantial changes were seen for treatment ages exceeding 12 years. Significant effects of radiation dose and age at exposure were observed for kyphoscoliosis (with vertebral body dose gradients < 35 Gy), hypoplasia and soft tissue defects and asymmetrical growth. Conclusion: Tolerance doses of 20 Gy need to be respected for growing bone, particularly in children treated under the age of 6 years. The late treatment sequelae analysed in the present study are largely avoided with the use of current therapeutic protocols. However, the systematic evaluation, documentation and continuous analysis of adverse events in paediatric oncology remains essential, as does the evaluation of novel radio(chemo)therapeutic approaches. (orig.)

Boron concentration measurements by alpha spectrometry and quantitative neutron autoradiography in cells and tissues treated with different boronated formulations and administration protocols

International Nuclear Information System (INIS)

Bortolussi, Silva; Ciani, Laura; Postuma, Ian; Protti, Nicoletta; Luca Reversi,; Bruschi, Piero; Ferrari, Cinzia; Cansolino, Laura; Panza, Luigi; Ristori, Sandra; Altieri, Saverio

2014-01-01

The possibility to measure boron concentration with high precision in tissues that will be irradiated represents a fundamental step for a safe and effective BNCT treatment. In Pavia, two techniques have been used for this purpose, a quantitative method based on charged particles spectrometry and a boron biodistribution imaging based on neutron autoradiography. A quantitative method to determine boron concentration by neutron autoradiography has been recently set-up and calibrated for the measurement of biological samples, both solid and liquid, in the frame of the feasibility study of BNCT. This technique was calibrated and the obtained results were cross checked with those of α spectrometry, in order to validate them. The comparisons were performed using tissues taken form animals treated with different boron administration protocols. Subsequently the quantitative neutron autoradiography was employed to measure osteosarcoma cell samples treated with BPA and with new boronated formulations. - Highlights: • A method for 10B measurements in samples based on neutron autoradiography was developed. • The results were compared with those of alpha spectrometry applied on tissue and cell samples. • Boronated liposomes were developed and administered to osteosarcoma cell cultures. • Neutron autoradiography was employed to measure boron concentration due to liposomes. • Liposomes were proved to be more effective in concentrating boron in cells than BPA

Normal Tissue Complication Probability Modeling of Acute Hematologic Toxicity in Cervical Cancer Patients Treated With Chemoradiotherapy

International Nuclear Information System (INIS)

Rose, Brent S.; Aydogan, Bulent; Liang, Yun; Yeginer, Mete; Hasselle, Michael D.; Dandekar, Virag; Bafana, Rounak; Yashar, Catheryn M.; Mundt, Arno J.; Roeske, John C.; Mell, Loren K.

2011-01-01

Purpose: To test the hypothesis that increased pelvic bone marrow (BM) irradiation is associated with increased hematologic toxicity (HT) in cervical cancer patients undergoing chemoradiotherapy and to develop a normal tissue complication probability (NTCP) model for HT. Methods and Materials: We tested associations between hematologic nadirs during chemoradiotherapy and the volume of BM receiving ≥10 and 20 Gy (V 10 and V 20 ) using a previously developed linear regression model. The validation cohort consisted of 44 cervical cancer patients treated with concurrent cisplatin and pelvic radiotherapy. Subsequently, these data were pooled with data from 37 identically treated patients from a previous study, forming a cohort of 81 patients for normal tissue complication probability analysis. Generalized linear modeling was used to test associations between hematologic nadirs and dosimetric parameters, adjusting for body mass index. Receiver operating characteristic curves were used to derive optimal dosimetric planning constraints. Results: In the validation cohort, significant negative correlations were observed between white blood cell count nadir and V 10 (regression coefficient (β) = -0.060, p = 0.009) and V 20 (β = -0.044, p = 0.010). In the combined cohort, the (adjusted) β estimates for log (white blood cell) vs. V 10 and V 20 were as follows: -0.022 (p = 0.025) and -0.021 (p = 0.002), respectively. Patients with V 10 ≥ 95% were more likely to experience Grade ≥3 leukopenia (68.8% vs. 24.6%, p 20 > 76% (57.7% vs. 21.8%, p = 0.001). Conclusions: These findings support the hypothesis that HT increases with increasing pelvic BM volume irradiated. Efforts to maintain V 10 20 < 76% may reduce HT.

Development of the fluidized bed thermal treatment process for treating mixed waste

International Nuclear Information System (INIS)

Semones, G.B.; Williams, P.M.; Stiefvater, S.P.; Mitchell, D.L.; Roecker, B.D.

1993-01-01

A fluidized bed system is being developed at Rocky Flats for the treatment of mixed waste (a mixture of radioactive and chemically hazardous waste). The current program builds on experience gained in the 1970's and 1980's in tests with bench-scale, pilot-scale, and demonstration-scale fluidized bed systems. The system operates at low temperatures (∼ 525--600 degree C) which eliminates many of the disadvantages associated with high temperature thermal treatment processes. The process has shown the ability to destroy polychlorinated biphenyls (PCB's) with 99.9999% (''six-nines'') destruction efficiency in tests monitored by the Environmental Protection Agency (EPA). The bed makes use of in situ neutralization of acidic off-gases by incorporating sodium carbonate (Na 2 CO 3 ) in the bed media. This eliminates using wet scrubbers to treat the off-gas; these produce a high volume of secondary waste. Once in operation, it is expected that the fluidized bed process will yield up to a 40:1 reduction in the volume of the waste

Differences in breast tissue oxygenation following radiotherapy

International Nuclear Information System (INIS)

Dornfeld, Ken; Gessert, Charles E.; Renier, Colleen M.; McNaney, David D.; Urias, Rodolfo E.; Knowles, Denise M.; Beauduy, Jean L.; Widell, Sherry L.; McDonald, Bonita L.

2011-01-01

Tissue perfusion and oxygenation changes following radiotherapy may result from and/or contribute to the toxicity of treatment. Breast tissue oxygenation levels were determined in the treated and non-treated breast 1 year after radiotherapy for breast conserving treatment. Transcutaneous oxygenation varied between subjects in both treated and non-treated breast. Subjects without diabetes mellitus (n = 16) had an average oxygenation level of 64.8 ± 19.9 mmHg in the irradiated breast and an average of 72.3 ± 18.1 mmHg (p = 0.018) at the corresponding location in the control breast. Patients with diabetes (n = 4) showed a different oxygenation pattern, with lower oxygenation levels in control tissue and no decrease in the irradiated breast. This study suggests oxygenation levels in normal tissues vary between patients and may respond differently after radiotherapy.

In vivo non-thermal irreversible electroporation impact on rat liver galvanic apparent internal resistance

International Nuclear Information System (INIS)

Golberg, A; Laufer, S; Rabinowitch, H D; Rubinsky, B

2011-01-01

Non-thermal irreversible electroporation (NTIRE) is a biophysical phenomenon which involves application of electric field pulses to cells or tissues, causing certain rearrangements in the membrane structure leading to cell death. The treated tissue ac impedance changes induced by electroporation were shown to be the indicators for NTIRE efficiency. In a previous study we characterized in vitro tissue galvanic apparent internal resistance (GAIR) changes due to NTIRE. Here we describe an in vivo study in which we monitored the GAIR changes of a rat liver treated by NTIRE. Electrical pulses were delivered through the same Zn/Cu electrodes by which GAIR was measured. GAIR was measured before and for 3 h after the treatment at 15 min intervals. The results were compared to the established ac bioimpedance measurement method. A decrease of 33% was measured immediately after the NTIRE treatment and a 40% decrease was measured after 3 h in GAIR values; in the same time 40% and 47% decrease respectively were measured by ac bioimpedance analyses. The temperature increase due to the NTIRE was only 0.5 deg. C. The results open the way for an inexpensive, self-powered in vivo real-time NTIRE effectiveness measurement.

In vivo non-thermal irreversible electroporation impact on rat liver galvanic apparent internal resistance

Energy Technology Data Exchange (ETDEWEB)

Golberg, A; Laufer, S [Center for Bioengineering in the Service of Humanity and Society, School of Computer Science and Engineering, Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Rabinowitch, H D [Robert H Smith Faculty of Agriculture, Food and Environment, Robert H Smith Institute of Plant Science and Genetics in Agriculture, Hebrew University of Jerusalem, Rehovot 76 100 (Israel); Rubinsky, B, E-mail: Rabin@agri.huji.ac.il [Department of Mechanical Engineering, Graduate Program in Biophysics, University of California at Berkeley, Berkeley, CA 84720 (United States)

2011-02-21

Non-thermal irreversible electroporation (NTIRE) is a biophysical phenomenon which involves application of electric field pulses to cells or tissues, causing certain rearrangements in the membrane structure leading to cell death. The treated tissue ac impedance changes induced by electroporation were shown to be the indicators for NTIRE efficiency. In a previous study we characterized in vitro tissue galvanic apparent internal resistance (GAIR) changes due to NTIRE. Here we describe an in vivo study in which we monitored the GAIR changes of a rat liver treated by NTIRE. Electrical pulses were delivered through the same Zn/Cu electrodes by which GAIR was measured. GAIR was measured before and for 3 h after the treatment at 15 min intervals. The results were compared to the established ac bioimpedance measurement method. A decrease of 33% was measured immediately after the NTIRE treatment and a 40% decrease was measured after 3 h in GAIR values; in the same time 40% and 47% decrease respectively were measured by ac bioimpedance analyses. The temperature increase due to the NTIRE was only 0.5 deg. C. The results open the way for an inexpensive, self-powered in vivo real-time NTIRE effectiveness measurement.

Survival and growth of Alfalfa (Medicago sativa l.) inoculated with an am fungus (Glomus intraradices) in contaminated soils treated with two different remediation technologies (bio-pile and thermal desorption)

International Nuclear Information System (INIS)

Norini, M.P.; Beguiristain, Th.; Leyval, C.

2005-01-01

Polycyclic aromatic hydrocarbons (PAHs) represent a group of persistent and toxic soil pollutants that are of major public concern due to their mutagenic and carcinogenic property. Phyto-remediation is the use of plants and their associated microorganisms for remediation of polluted soils. Phyto-remediation could be used in conjunction with other remediation technologies to reduce the contamination to safe levels and maintain or restore soil physico-chemical and biological properties. Most plant species form mycorrhizas with symbiotic fungi. It was shown that AM fungi enhance survival and plant growth in PAH contaminated soils. Mycorrhizal fungi also enhance the biotransformation or biodegradation of PAH, although the effect differed between soils. A rhizosphere and myco-rhizosphere gradient of PAH concentrations was observed, with decreased PAH concentration with decreased distance to roots. Different microbial communities were found in the rhizosphere of AM and non-mycorrhizal plants in comparison to bulk soil, suggesting that AM could affect PAH degradation by changing microbial communities. We investigated the effect of mycorrhizal fungi and nutrients on the ability of alfalfa to grow on soil contaminated with PAHs before and after two remediation treatments. We used soil from an industrial site (Homecourt, North East part of France) highly contaminated with PAH (2000 mg kg -1 ), which has been partially treated by two different remediation technologies (bio-pile and thermal desorption). The bio-pile treatment consisted of piling the contaminated soil with stimulation of aerobic microbial activity by aeration and addition of nutrient solution, and reduced PAH concentration to around 300 mg kg-1. With the thermal desorption treatment the soil was heated to around 500 deg. C so that PAH vaporized and were separated from the soil. The residual PAH concentration in soil was 40 mg kg -1 . Treated and non-treated contaminated soil was planted with alfalfa (Medicago

Thermal coagulation-induced changes of the optical properties of normal and adenomatous human colon tissues in vitro in the spectral range 400-1100 nm

International Nuclear Information System (INIS)

Ao Huilan; Xing Da; Wei Huajiang; Gu Huaimin; Wu Guoyong; Lu Jianjun

2008-01-01

The absorption coefficients, the reduced scattering coefficients and the optical penetration depths for native and coagulated human normal and adenomatous colon tissues in vitro were determined over the range of 400-1100 nm using a spectrophotometer with an internal integrating sphere system, and the inverse adding-doubling method was applied to calculate the tissue optical properties from diffuse reflectance and total transmittance measurements. The experimental results showed that in the range of 400-1100 nm there were larger absorption coefficients (P < 0.01) and smaller reduced scattering coefficients (P < 0.01) for adenomatous colon tissues than for normal colon tissues, and there were smaller optical penetration depths for adenomatous colon tissues than for normal colon tissues, especially in the near-infrared wavelength. Thermal coagulation induced significant increase of the absorption coefficients and reduced scattering coefficients for the normal and adenomatous colon tissues, and significantly reduced decrease of the optical penetration depths for the normal and adenomatous colon tissues. The smaller optical penetration depth for coagulated adenomatous colon tissues is a disadvantage for laser-induced thermotherapy (LITT) and photodynamic therapy (PDT). It is necessary to adjust the application parameters of lasers to achieve optimal therapy

Heat dissipation by blood circulation and airway tissue heat absorption in a canine model of inhalational thermal injury.

Science.gov (United States)

Wan, Jiangbo; Zhang, Guoan; Qiu, Yuxuan; Wen, Chunquan; Fu, Tairan

2016-05-01

This study aimed to further explore heat dissipation by blood circulation and airway tissue heat absorption in an inhalational thermal injury model. Twelve adult male Beagle dogs were divided into four groups to inhale heated air for 10min: the control group, group I (100.5°C), group II (161.5°C), and group III (218°C). The relative humidity and temperature of the inhaled heated air were measured in the heating tube and trachea, as were blood temperatures and flow velocities in both common jugular veins. Formulas were used to calculate the total heat quantity reduction of the heated air, heat dissipation by the blood, and airway tissue heat absorption. The blood temperatures of both the common jugular veins increased by 0.29°C±0.07°C to 2.96°C±0.24°C and the mean blood flow volume after injury induction was about 1.30-1.74 times greater than before injury induction. The proportions of heat dissipated by the blood and airway tissue heat absorption were 68.92%±14.88% and 31.13%±14.87%, respectively. The heat dissipating ability of the blood circulation was demonstrated and improved upon along with tissue heat absorption owing to increased regional blood flow. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Temperature-monitored optical treatment for radial tissue expansion.

Science.gov (United States)

Bak, Jinoh; Kang, Hyun Wook

2017-07-01

Esophageal stricture occurs in 7-23% of patients with gastroesophageal reflux disease. However, the current treatments including stent therapy, balloon dilation, and bougienage involve limitations such as stent migration, formation of the new strictures, and snowplow effect. The purpose of the current study was to investigate the feasibility of structural expansion in tubular tissue ex vivo during temperature-monitored photothermal treatment with a diffusing applicator for esophageal stricture. Porcine liver was used as an ex vivo tissue sample for the current study. A glass tube was used to maintain a constant distance between the diffuser and tissue surface and to evaluate any variations in the luminal area after 10-W 1470-nm laser irradiation for potential stricture treatment. The 3D goniometer measurements confirmed roughly isotropic distribution with less than 10% deviation from the average angular intensity over 2π (i.e., 0.86 ± 0.09 in arbitrary unit) from the diffusing applicator. The 30-s irradiation increased the tissue temperature up to 72.5 °C, but due to temperature feedback, the interstitial tissue temperature became saturated at 70 °C (i.e., steady-state error = ±0.4 °C). The irradiation times longer than 5 s presented area expansion index of 1.00 ± 0.04, signifying that irreversible tissue denaturation permanently deformed the lumen in a circular shape and secured the equivalent luminal area to that of the glass tube. Application of a temperature feedback controller for photothermal treatment with the diffusing applicator can regulate the degree of thermal denaturation to feasibly treat esophageal stricture in a tubular tissue.

Optical clearing of vaginal tissues in cadavers

Science.gov (United States)

Chang, Chun-Hung; Hardy, Luke A.; Peters, Michael G.; Bastawros, Dina A.; Myers, Erinn M.; Kennelly, Michael J.; Fried, Nathaniel M.

2018-02-01

A nonsurgical laser procedure is being developed for treatment of female stress urinary incontinence (SUI). Previous studies in porcine vaginal tissues, ex vivo, as well as computer simulations, showed the feasibility of using near-infrared laser energy delivered through a transvaginal contact cooling probe to thermally remodel endopelvic fascia, while preserving the vaginal wall from thermal damage. This study explores optical properties of vaginal tissue in cadavers as an intermediate step towards future pre-clinical and clinical studies. Optical clearing of tissue using glycerol resulted in a 15-17% increase in optical transmission after 11 min at room temperature (and a calculated 32.5% increase at body temperature). Subsurface thermal lesions were created using power of 4.6 - 6.4 W, 5.2-mm spot, and 30 s irradiation time, resulting in partial preservation of vaginal wall to 0.8 - 1.1 mm depth.

Application of Thermal Desorption Unit (TDU) to treat low-toxicity mineral oil base cuttings in Barinas District, Venezuela

Energy Technology Data Exchange (ETDEWEB)

Rendon, Ruben [Petroleos de Venezuela, Caracas (Venezuela); Luzardo, Janeth; Alcoba, Alcides [M-I SWACO, Houston, TX (United States)

2008-07-01

The potential environmental impact of oil-based drill cuttings is generating increased scrutiny in the oil and gas industry. If left untreated, oil-based cuttings not only increase the risk of environmental liabilities, but also affect revenue, as drilling generates wastes that in most cases require special treatment before disposal. Consequently, the oil industry is looking for technologies to help minimize environmental liabilities. Accordingly, the Barinas District of PDVSA has started a pilot trial to treat oil-based drilling cuttings by applying thermal desorption technology. The main objective of this technology is recovering trapped hydrocarbons, while minimizing wastes and preparing solids to be disposed of through a mobile treatment plant. This novel technology has been used worldwide to treat organic pollutants in soil. Thermal desorption is a technology based on the application of heat in soils polluted with organic compounds. With this technology, target temperatures vary according to the type and concentration of detected pollutants along with its characterization, in such a way that compounds are disposed of by volatilization. As part of the integral waste management development along with the pilot trial for hydrocarbon-contaminated solid waste treatment, trials on soils were undertaken by applying process-generated ashes in equally-sized bins, with different mixtures (ashes, ashes organic material, ashes-organic material-sand, ashes-land). The resulting process offers an immediate soil remediation and final disposal solution for toxic and dangerous waste. (author)

Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

Energy Technology Data Exchange (ETDEWEB)

Gallyamov, Marat O., E-mail: glm@spm.phys.msu.ru [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Chaschin, Ivan S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Khokhlova, Marina A. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Grigorev, Timofey E. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E. [Bakulev Scientific Center for Cardiovascular Surgery of the Russian Academy of Medical Sciences, Roublyevskoe Sh. 135, Moscow 121552 (Russian Federation); Badun, Gennadii A.; Chernysheva, Maria G. [Radiochemistry Division, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Khokhlov, Alexei R. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation)

2014-04-01

Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H{sub 2}O and CO{sub 2}. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA

Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

International Nuclear Information System (INIS)

Gallyamov, Marat O.; Chaschin, Ivan S.; Khokhlova, Marina A.; Grigorev, Timofey E.; Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E.; Badun, Gennadii A.; Chernysheva, Maria G.; Khokhlov, Alexei R.

2014-01-01

Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H 2 O and CO 2 . Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA-stabilised bovine

Non-thermal dielectric barrier discharge plasma induces angiogenesis through reactive oxygen species.

Science.gov (United States)

Arjunan, Krishna Priya; Friedman, Gary; Fridman, Alexander; Clyne, Alisa Morss

2012-01-07

Vascularization plays a key role in processes such as wound healing and tissue engineering. Non-thermal plasma, which primarily produces reactive oxygen species (ROS), has recently emerged as an efficient tool in medical applications including blood coagulation, sterilization and malignant cell apoptosis. Liquids and porcine aortic endothelial cells were treated with a non-thermal dielectric barrier discharge plasma in vitro. Plasma treatment of phosphate-buffered saline (PBS) and serum-free medium increased ROS concentration in a dose-dependent manner, with a higher concentration observed in serum-free medium compared with PBS. Species concentration inside cells peaked 1 h after treatment, followed by a decrease 3 h post treatment. Endothelial cells treated with a plasma dose of 4.2 J cm(-2) had 1.7 times more cells than untreated samples 5 days after plasma treatment. The 4.2 J cm(-2) plasma dose increased two-dimensional migration distance by 40 per cent compared with untreated control, while the number of cells that migrated through a three-dimensional collagen gel increased by 15 per cent. Tube formation was also enhanced by plasma treatment, with tube lengths in plasma-treated samples measuring 2.6 times longer than control samples. A fibroblast growth factor-2 (FGF-2) neutralizing antibody and ROS scavengers abrogated these angiogenic effects. These data indicate that plasma enhanced proliferation, migration and tube formation is due to FGF-2 release induced by plasma-produced ROS. Non-thermal plasma may be used as a potential tool for applying ROS in precise doses to enhance vascularization.

Detecting thermal phase transitions in corneal stroma by fluorescence micro-imaging analysis

Science.gov (United States)

Matteini, P.; Rossi, F.; Ratto, F.; Bruno, I.; Nesi, P.; Pini, R.

2008-02-01

Thermal modifications induced in corneal stroma were investigated by the use of fluorescence microscopy. Freshly extracted porcine corneas were immersed for 5 minutes in a water bath at temperatures in the 35-90°C range and stored in formalin. The samples were then sliced in 200-μm-thick transversal sections and analyzed under a stereomicroscope to assess corneal shrinkage. Fluorescence images of the thermally treated corneal samples were acquired using a slow-scan cooled CCD camera, after staining the slices with Indocyanine Green (ICG) fluorescent dye which allowed to detect fluorescence signal from the whole tissue. All measurements were performed using an inverted epifluorescence microscope equipped with a mercury lamp. The thermally-induced modifications to the corneal specimens were evaluated by studying the grey level distribution in the fluorescence images. For each acquired image, Discrete Fourier Transform (DFT) and entropy analyses were performed. The spatial distribution of DFT absolute value indicated the spatial orientation of the lamellar planes, while entropy was used to study the image texture, correlated to the stromal structural transitions. As a result, it was possible to indicate a temperature threshold value (62°C) for high thermal damage, resulting in a disorganization of the lamellar planes and in full agreement with the measured temperature for corneal shrinkage onset. Analysis of the image entropy evidenced five strong modifications in stromal architecture at temperatures of ~45°C, 53°C, 57°C, 66°C, 75°C. The proposed procedure proved to be an effective micro-imaging method capable of detecting subtle changes in corneal tissue subjected to thermal treatment.

FLAMMABILITY OF HERBICIDE-TREATED GUAVA FOLIAGE

Science.gov (United States)

Guava leaves treated with herbicide were found to be less flammable than untreated green leaves or dead leaves . Differences in flammability were...determined by small-scale laboratory fires, differential thermal analysis, and thermogravimetric analysis. The herbicide-treated leaves had a higher ash

Uptake and Tissue Distribution of Pharmaceuticals and Personal Care Products in Wild Fish from Treated-Wastewater-Impacted Streams.

Science.gov (United States)

Tanoue, Rumi; Nomiyama, Kei; Nakamura, Haruna; Kim, Joon-Woo; Isobe, Tomohiko; Shinohara, Ryota; Kunisue, Tatsuya; Tanabe, Shinsuke

2015-10-06

A fish plasma model (FPM) has been proposed as a screening technique to prioritize potential hazardous pharmaceuticals to wild fish. However, this approach does not account for inter- or intraspecies variability of pharmacokinetic and pharmacodynamic parameters. The present study elucidated the uptake potency (from ambient water), tissue distribution, and biological risk of 20 pharmaceutical and personal care product (PPCP) residues in wild cyprinoid fish inhabiting treated-wastewater-impacted streams. In order to clarify the uncertainty of the FPM for PPCPs, we compared the plasma bioaccumulation factor in the field (BAFplasma = measured fish plasma/ambient water concentration ratio) with the predicted plasma bioconcentration factor (BCFplasma = fish plasma predicted by use of theoretical partition coefficients/ambient water concentration ratio) in the actual environment. As a result, the measured maximum BAFplasma of inflammatory agents was up to 17 times higher than theoretical BCFplasma values, leading to possible underestimation of toxicological risk on wild fish. When the tissue-blood partition coefficients (tissue/blood concentration ratios) of PPCPs were estimated, higher transportability into tissues, especially the brain, was found for psychotropic agents, but brain/plasma ratios widely varied among individual fish (up to 28-fold). In the present study, we provide a valuable data set on the intraspecies variability of PPCP pharmacokinetics, and our results emphasize the importance of determining PPCP concentrations in possible target organs as well as in the blood to assess the risk of PPCPs on wild fish.

Thermal modelling using discrete vasculature for thermal therapy: a review

Science.gov (United States)

Kok, H.P.; Gellermann, J.; van den Berg, C.A.T.; Stauffer, P.R.; Hand, J.W.; Crezee, J.

2013-01-01

Reliable temperature information during clinical hyperthermia and thermal ablation is essential for adequate treatment control, but conventional temperature measurements do not provide 3D temperature information. Treatment planning is a very useful tool to improve treatment quality and substantial progress has been made over the last decade. Thermal modelling is a very important and challenging aspect of hyperthermia treatment planning. Various thermal models have been developed for this purpose, with varying complexity. Since blood perfusion is such an important factor in thermal redistribution of energy in in vivo tissue, thermal simulations are most accurately performed by modelling discrete vasculature. This review describes the progress in thermal modelling with discrete vasculature for the purpose of hyperthermia treatment planning and thermal ablation. There has been significant progress in thermal modelling with discrete vasculature. Recent developments have made real-time simulations possible, which can provide feedback during treatment for improved therapy. Future clinical application of thermal modelling with discrete vasculature in hyperthermia treatment planning is expected to further improve treatment quality. PMID:23738700

Ultrasonic Histotripsy for Tissue Therapy

Science.gov (United States)

Pahk, K. J.; Dhar, D. K.; Malago, M.; Saffari, N.

2015-01-01

Hepatocyte transplantation has been considered and investigated as a promising and alternative method to liver transplantation for treating liver-based metabolic disorder in newborns over the past two decades. Although some clinical trials have been conducted and shown clinical benefits and outcomes, it is difficult to deliver and achieve a desired level of integration and transplantation of hepatocytes in the liver parenchyma. To overcome this problem, this work introduces an alternative method to a portal-infused-hepatocyte cell transplantation. To improve the level of engraftment of transplantable hepatocytes, these are injected directly into cavities generated by ultrasonic histotripsy. Histotripsy is an extracorporeal noninvasive technique which has been recently developed using high intensity focused ultrasound (HIFU) for inducing tissue fractionation with no coagulative necrosis. The exact mechanisms for the tissue fractionation are not well understood yet; but the possible mechanisms are thought to be a combination of nonlinear wave propagation effect, explosive bubble growth and ultrasonic atomization. The main objectives of this work are to demonstrate the feasibility of this new cell therapy and evaluate and distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion. In the present work, numerical studies on the bubble dynamics (the Gilmore-Akulichev bubble model coupled with the Khokhlov-Zabolotskaya-Kuznetsov equation) and both ex- and in vivo liver experiments are conducted with histological analysis (haematoxylin and eosin stain). The numerical and the experimental results suggest that (a) the acoustic emissions emitted during the thermal ablation and the histotripsy exposure can be distinguished both numerically and experimentally and (b) the proposed cell therapy may potentially form an effective and safe clinical treatment for replacing and correcting disordered hepatocytes, although the

Ultrasonic Histotripsy for Tissue Therapy

International Nuclear Information System (INIS)

Pahk, K J; Saffari, N; Dhar, D K; Malago, M

2015-01-01

Hepatocyte transplantation has been considered and investigated as a promising and alternative method to liver transplantation for treating liver-based metabolic disorder in newborns over the past two decades. Although some clinical trials have been conducted and shown clinical benefits and outcomes, it is difficult to deliver and achieve a desired level of integration and transplantation of hepatocytes in the liver parenchyma. To overcome this problem, this work introduces an alternative method to a portal-infused-hepatocyte cell transplantation. To improve the level of engraftment of transplantable hepatocytes, these are injected directly into cavities generated by ultrasonic histotripsy. Histotripsy is an extracorporeal noninvasive technique which has been recently developed using high intensity focused ultrasound (HIFU) for inducing tissue fractionation with no coagulative necrosis. The exact mechanisms for the tissue fractionation are not well understood yet; but the possible mechanisms are thought to be a combination of nonlinear wave propagation effect, explosive bubble growth and ultrasonic atomization. The main objectives of this work are to demonstrate the feasibility of this new cell therapy and evaluate and distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion. In the present work, numerical studies on the bubble dynamics (the Gilmore-Akulichev bubble model coupled with the Khokhlov-Zabolotskaya-Kuznetsov equation) and both ex- and in vivo liver experiments are conducted with histological analysis (haematoxylin and eosin stain). The numerical and the experimental results suggest that (a) the acoustic emissions emitted during the thermal ablation and the histotripsy exposure can be distinguished both numerically and experimentally and (b) the proposed cell therapy may potentially form an effective and safe clinical treatment for replacing and correcting disordered hepatocytes, although the

Thyroid tissue: US-guided percutaneous laser thermal ablation.

Science.gov (United States)

Pacella, Claudio Maurizio; Bizzarri, Giancarlo; Spiezia, Stefano; Bianchini, Antonio; Guglielmi, Rinaldo; Crescenzi, Anna; Pacella, Sara; Toscano, Vincenzo; Papini, Enrico

2004-07-01

To evaluate in vivo the safety and effectiveness of percutaneous laser thermal ablation (LTA) in the debulking of thyroid lesions. Twenty-five adult patients at poor surgical risk with cold nodules (n = 8), autonomously hyperfunctioning thyroid nodules (n = 16), or anaplastic carcinoma (n = 1) underwent LTA. One to four 21-gauge spinal needles were inserted with ultrasonographic (US) guidance into the thyroid lesions. A 300-microm-diameter quartz optical fiber was advanced through the sheath of the needle. Nd:YAG laser was used with output power of 3-5 W. Side effects, complications, and clinical and hormonal changes were evaluated at the end of LTA and during follow-up. Linear regression analysis was used to investigate the correlation between energy delivered and reduction in nodule volume. Volume of induced necrosis and reduction in nodule volume were assessed with US or computed tomography. LTA was performed without difficulties in 76 LTA sessions. After treatment with 5 W, two patients experienced mild dysphonia, which resolved after 48 hours and 2 months. Improvement of local compression symptoms was experienced by 12 of 14 (86%) patients. Thyroid-stimulating hormone (TSH) was detectable in five of 16 (31%) patients with hyperfunctioning nodules at 6 months after LTA. Volume of induced necrosis ranged from 0.8 to 3.9 mL per session. Anaplastic carcinoma treated with four fibers yielded 32.0 mL of necrosis. Echo structure and baseline volume did not influence response. Energy load and reduction in nodule volume were significantly correlated (r(2) =.75, P nodule volume reduction at 6 months in hyperfunctioning nodules was 3.3 mL +/- 2.8 (62% +/- 21.4 [SD]) and in cold nodules was 7.7 mL +/- 7.5 (63% +/- 13.8). LTA may be a therapeutic tool for highly selected problems in the treatment of thyroid lesions. Copyright RSNA, 2004

[Lasers in dentistry. Part B--Interaction with biological tissues and the effect on the soft tissues of the oral cavity, the hard tissues of the tooth and the dental pulp].

Science.gov (United States)

Moshonov, J; Stabholz, A; Leopold, Y; Rosenberg, I; Stabholz, A

2001-10-01

The interaction of laser energy with target tissue is mainly determined by two non operator-dependent factors: the specific wavelength of the laser and the optical properties of the target tissues. Power density, energy density, pulse repetition rate, pulse duration and the mode of energy transferring to the tissue are dictated by the clinician. Combination of these factors enables to control optimal response for the clinical application. Four responses are described when the laser beam hits the target tissue: reflection, absorption, transmission and scattering. Three main mechanisms of interaction between the laser and the biological tissues exist: photothermic, photoacoustic and photochemical. The effect of lasers on the soft tissues of the oral cavity is based on transformation of light energy into thermal energy which, in turn heats the target tissue to produce the desirable effect. In comparison to the scalpel used in surgical procedures, the laser beam is characterized by tissue natural sterility and by minimum bleeding during the surgical procedures due to blood vessels welding. The various effects achieved by the temperature elevation during the laser application on the soft tissue are: I. coagulation and hemostasis II. tissue sterilization III. tissue welding IV. incision and excision V. ablation and vaporization Ablation and melting are the two basic modalities by which the effect of lasers on the hard tissues of the tooth is produced. When discussing the effect of laser on dental hard tissues, the energy absorption in the hydroxyapatite plays a major role in addition to its absorption in water. When laser energy is absorbed in the water of the hard tissues, a rapid volume expansion of the evaporating water occurs as a result of a substantial temperature elevation in the interaction site. Microexplosions are produced causing hard tissue disintegration. If pulp temperatures are raised beyond 5 degrees C level, damage to the dental pulp is irreversible

Effect of lunar materials on plant tissue culture.

Science.gov (United States)

Walkinshaw, C. H.; Venketeswaran, S.; Baur, P. S.; Croley, T. E.; Scholes, V. E.; Weete, J. D.; Halliwell, R. S.; Hall, R. H.

1973-01-01

Lunar material collected during the Apollo 11, 12, 14, and 15 missions has been used to treat 12 species of higher plant tissue cultures. Biochemical and morphological studies have been conducted on several of these species. Tobacco tissue cultures treated with 0.22 g of lunar material exhibited increased greening more complex chloroplasts, less cytoplasmic vacuolation and greater vesiculation. Pine tissue cultures reacted to treatment by an increased deposition of tannin-like materials. The percentage of dry weight and soluble protein was increased in cultures treated with either lunar or terrestrial rock materials.

Thermal conductivity of polymer composites with oriented boron nitride

International Nuclear Information System (INIS)

Ahn, Hong Jun; Eoh, Young Jun; Park, Sung Dae; Kim, Eung Soo

2014-01-01

Highlights: • Thermal conductivity depended on the orientation of BN in the polymer matrices. • Hexagonal boron nitride (BN) particles were treated by C 27 H 27 N 3 O 2 and C 14 H 6 O 8 . • Amphiphilic-agent-treated BN particles are more easily oriented in the composite. • BN/PVA composites with C 14 H 6 O 8 -treated BN showed the highest thermal conductivity. • Thermal conductivity of the composites was compared with several theoretical models. - Abstract: Thermal conductivity of boron nitride (BN) with polyvinyl alcohol (PVA) and/or polyvinyl butyral (PVB) was investigated as a function of the degree of BN orientation, the numbers of hydroxyl groups in the polymer matrices and the amphiphilic agents used. The composites with in-plane orientation of BN showed a higher thermal conductivity than the composites with out-of-plane orientation of BN due to the increase of thermal pathway. For a given BN content, the composites with in-plane orientation of BN/PVA showed higher thermal conductivity than the composites with in-plane orientation of BN/PVB. This result could be attributed to the improved degree of orientation of BN, caused by a larger number of hydroxyl groups being present. Those treated with C 14 H 6 O 8 amphiphilic agent demonstrated a higher thermal conductivity than those treated by C 27 H 27 N 3 O 2 . The measured thermal conductivity of the composites was compared with that predicted by the several theoretical models

High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

OpenAIRE

Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

2011-01-01

CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at ...

Collecting and Storing Tissue, Blood, and Bone Marrow Samples From Patients With Rhabdomyosarcoma or Other Soft Tissue Sarcoma

Science.gov (United States)

2017-12-11

Adult Rhabdomyosarcoma; Childhood Desmoplastic Small Round Cell Tumor; Chordoma; Desmoid Tumor; Metastatic Childhood Soft Tissue Sarcoma; Nonmetastatic Childhood Soft Tissue Sarcoma; Previously Treated Childhood Rhabdomyosarcoma; Previously Untreated Childhood Rhabdomyosarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Stage I Adult Soft Tissue Sarcoma; Stage II Adult Soft Tissue Sarcoma; Stage III Adult Soft Tissue Sarcoma; Stage IV Adult Soft Tissue Sarcoma

A portable thermal imaging device as a feedback system for breast cancer treatment

Science.gov (United States)

Hoffer, Oshrit A.; Ben-David, Merav A.; Katz, Eyal; Sholomov, Meny; Kelson, Itzhak; Gannot, Israel

2018-02-01

Breast cancer is the most frequently diagnosed cancer among women in the Western world. Currently, no imaging technique assesses tumor heat generation and vasculature changes during radiotherapy in viable tumor and as adjuvant therapy. Thermography is a non-ionizing, non-invasive, portable and low-cost imaging modality. The purpose of this study was to investigate the use of thermography in cancer treatment monitoring for feedback purposes. Six stage-IV breast cancer patients with viable breast tumor and 8 patients (9 breasts) who underwent tumor resection were monitored by a thermal camera prior to radiotherapy sessions over several weeks of radiation treatment. The thermal changes over the treated breast were calculated and analyzed for comparison with healthy surrounded breast tissue or contralateral breast. A model of a breast with a tumor was created. The COMSOL FEM software was used to carry out the analysis. The effects of tumor metabolism and breast tissue perfusion on the temperature difference were analyzed. All patients with active tumors exhibited drops in maximal temperature of the tumor during radiation therapy. The patients who underwent radiotherapy as adjuvant treatment exhibited a rise in maximal temperature over the treated breast in correlation with skin erythema during radiation. This difference between the groups was statistically significant (P=0.001). The simulated human breast cancer models analysis showed that tumor aggressiveness reduction causes decrease in the tumor temperature. Inflammation causes vasodilatation and increases tissue perfusion, resulted in an increase in breast tissue temperature. A correlation was demonstrated between the clinical outcome and the simulation. We report a method for monitoring cancer response to radiation therapy, which measures the physiological response along with clinical response. These anticipatory efficacy evaluations of radiotherapy during treatment may further promote changes in treatment regimen

Tissue injuries of wistar rats treated with hydroalcoholic extract of Sonchus oleraceus L.

Directory of Open Access Journals (Sweden)

Franciele Carla Prichoa

2011-09-01

Full Text Available The use of plant species is emerging as an important alternative in the treatment of injuries. Therefore, the extract of Sonchus oleraceus 10% was employed in the repair of skin lesions. A total of 36 male Wistar rats were subjected to a punch injury and divided into three groups: a negative control, receiving no treatment, a positive control, treated with Dersani, and the experimental group treated with the extract. The injury was assessed macroscopically and microscopically. Morphometric data was collected at the 3rd, 5th and 7th postoperative day, and the experimental group showed greater changes in shrinkage of the lesion compared to control groups. On the 3rd postoperative day, the injury in the experimental group showed less necrotic tissue, lower slough and more granulation tissue in relation to the positive control group. On the 7th and 10th postoperative day, the injury in the experimental group showed lower slough compared to the positive control group. Microscopic analysis of lesions on the 5th postoperative day revealed increased fibroplasia in the experimental group compared to control groups, while on the 14th postoperative day less neovascularization was evident in the experimental group and increased formation of hair follicles in the negative control group. The extract of S. oleraceus provided tissue repair in accordance with normal physiological patterns thus confirming empirical evidence for its use.O emprego de espécies vegetais vem surgindo como alternativa no tratamento de lesões. Dessa forma, foi utilizado o extrato hidroalcoólico de Sonchus oleraceus a 10% na reparação de lesões cutâneas. Trinta e seis ratos machos Wistar, foram submetidos a uma lesão com "punch" e distribuídos em três grupos: controle negativo, não recebeu tratamento; controle positivo, tratado com Dersani; e o experimental, tratado com extrato. A lesão foi avaliada macroscopicamente e microscopicamente. Os dados morfométricos mostraram que

Real-time optoacoustic monitoring of temperature in tissues

International Nuclear Information System (INIS)

Larina, Irina V; Larin, Kirill V; Esenaliev, Rinat O

2005-01-01

To improve the safety and efficacy of thermal therapy, it is necessary to map tissue temperature in real time with submillimetre spatial resolution. Accurate temperature maps may provide the necessary control of the boundaries of the heated regions and minimize thermal damage to surrounding normal tissues. Current imaging modalities fail to monitor tissue temperature in real time with high resolution and accuracy. We investigated a non-invasive optoacoustic method for accurate, real-time monitoring of tissue temperature during thermotherapy. In this study, we induced temperature gradients in tissue and tissue-like samples and monitored the temperature distribution using the optoacoustic technique. The fundamental harmonic of a Q-switched Nd : YAG laser (λ = 1064 nm) was used for optoacoustic wave generation and probing of tissue temperature. The tissue temperature was also monitored with a multi-sensor temperature probe inserted in the samples. Good agreement between optoacoustically measured and actual tissue temperatures was obtained. The accuracy of temperature monitoring was better than 1 0 C, while the spatial resolution was about 1 mm. These data suggest that the optoacoustic technique has the potential to be used for non-invasive, real-time temperature monitoring during thermotherapy

Pulsed photothermal radiometry in investigation of tissue destruction caused by CO2 laser action

Science.gov (United States)

Chebotareva, Galina P.; Zubov, Boris V.; Nikitin, Alexander P.; Rakcheev, Anatolii P.; Alexeeva, Larisa R.

1994-12-01

Pulsed photothermal radiometry (PPTR) of tissue based on the analysis of thermal radiation kinetics measured from tissue at laser heating is an effective method of laser-tissue interaction investigation. The processes of destruction under laser radiation action (coagulation, fusion and welding), which are characterized by definite dynamics of temperature in the region of laser heating, have been studied. The amplitude and kinetics of the thermal signal registered by PPTR technique depend on space and temporal temperature changes in the zone of heating, which is conditioned by the regime of laser action and internal processes in tissue. In the present study the investigation of thermal tissue destruction under action of high-power pulsed CO2 and YAG:Er-laser radiation has been carried out using PPTR. Soft and hard tissues have been examined. The nonlinear dependencies of thermal emission kinetics, the thermal signal amplitude, and the integral absorption on laser energy density are presented and discussed. We represent PPTR as a technique which can be used for the definition of the destruction threshold and for the regulation of laser action on tissue. PPTR method has been applied in clinics with the aim of more accurate definition of CO2 pulsed medical laser radiation dose for treatment of patients with different dermatological diseases.

Optimization of Non-Thermal Plasma Treatment in an In Vivo Model Organism.

Directory of Open Access Journals (Sweden)

Amanda Lee

Full Text Available Non-thermal plasma is increasingly being recognized for a wide range of medical and biological applications. However, the effect of non-thermal plasma on physiological functions is not well characterized in in vivo model systems. Here we use a genetically amenable, widely used model system, Drosophila melanogaster, to develop an in vivo system, and investigate the role of non-thermal plasma in blood cell differentiation. Although the blood system in Drosophila is primitive, it is an efficient system with three types of hemocytes, functioning during different developmental stages and environmental stimuli. Blood cell differentiation in Drosophila plays an essential role in tissue modeling during embryogenesis, morphogenesis and also in innate immunity. In this study, we optimized distance and frequency for a direct non-thermal plasma application, and standardized doses to treat larvae and adult flies so that there is no effect on the viability, fertility or locomotion of the organism. We discovered that at optimal distance, time and frequency, application of plasma induced blood cell differentiation in the Drosophila larval lymph gland. We articulate that the augmented differentiation could be due to an increase in the levels of reactive oxygen species (ROS upon non-thermal plasma application. Our studies open avenues to use Drosophila as a model system in plasma medicine to study various genetic disorders and biological processes where non-thermal plasma has a possible therapeutic application.

MR characterization of post-irradiation soft tissue edema

International Nuclear Information System (INIS)

Richardson, M.L.; Zink-Brody, G.C.; Patten, R.M.; Koh Wuijin; Conrad, E.U.

1996-01-01

Objective. Radiation therapy is often used to treat bone und soft tissue neoplasms, and commonly results in soft tissue edema in the radiation field. However, the time course, distribution and degree of this edema have not been well characterized. Our study was carried out to better define these features of the edema seen following neutron and photon radiation therapy. Results. In general, soft tissue signal intensity in the radiation field initially increased over time, peaking at about 6 months for neutron-treated patients and at about 12-18 months for photon-treated patients. Signal intensity then decreased slowly over time. However, at the end of the follow-up period, signal intensity remained elevated for most patients in both groups. Signal intensity in a particular tissue was greater and tended to persist longer on STIR sequences than on T2-weighted sequences. Survival analysis of signal intensity demonstrated much longer edema survival times for neutron-treated patients than for photon-treated patients. Signal intensity increase in the intramuscular septa persisted for much longer than for fat or muscle. A mild increase in size was noted in the subcutaneous fat and intramuscular septa. Muscle, on the other hand, showed a decrease in size following treatment. This was mild for the photon-treated group and more marked for the neutron-treated group. Conclusions. There is a relatively wide variation in the duration and degree of post-irradiation edema in soft tissues. This edema seems to persist longer in the intramuscular septa than in fat or muscle. Although the duration of follow-up was limited, our study suggests that this edema resolves in roughly half the photon-treated patients within 2-3 years post-treatment and in less than 20% of neutron-treated patients by 3-4 years post-treatment. Muscle atrophy was seen in both photon- and neutron-treated patients, but was more severe in the neutron-treated group. (orig./vhe). With 4 figs

Disrupted G1 to S phase clearance via cyclin signaling impairs liver tissue repair in thioacetamide-treated type 1 diabetic rats

International Nuclear Information System (INIS)

Devi, Sachin S.; Mehendale, Harihara M.

2005-01-01

Previously we reported that a nonlethal dose of thioacetamide (TA, 300 mg/kg) causes 90% mortality in type 1 diabetic (DB) rats because of irreversible acute liver injury owing to inhibited hepatic tissue repair, primarily due to blockage of G 0 to S phase progression of cell division cycle. On the other hand, DB rats receiving 30 mg TA/kg exhibited equal initial liver injury and delayed tissue repair compared to nondiabetic (NDB) rats receiving 300 mg TA/kg, resulting in a delay in recovery from liver injury and survival. The objective of the present study was to test the hypothesis that impaired cyclin-regulated progression of G 1 to S phase of the cell cycle may explain inhibited liver tissue repair, hepatic failure, and death, contrasted with delayed liver tissue repair but survival observed in the DB rats receiving 300 in contrast to 30 mg TA/kg. In the TA-treated NDB rats sustained MAPKs and cyclin expression resulted in higher phosphorylation of retinoblastoma (pRb), explaining prompt tissue repair and survival. In contrast, DB rats receiving the same dose of TA (300 mg/kg) exhibited suppressed MAPKs and cyclin expression that led to inhibition of pRb, inhibited tissue repair, and death. On the other hand, DB rats receiving 30 mg TA/kg exhibited delayed up regulation of MAPK signaling that delayed the expression of CD1 and pRb, explaining delayed stimulation of tissue repair observed in this group. In conclusion, the hepatotoxicant TA has a dose-dependent adverse effect on cyclin-regulated pRb signaling: the lower dose causes a recoverable delay, whereas the higher dose inhibits it with corresponding effect on the ultimate outcomes on hepatic tissue repair; this dose-dependent adverse effect is substantially shifted to the left of the dose response curve in diabetes

Linearly chirped fiber Bragg grating response to thermal gradient: from bench tests to the real-time assessment during in vivo laser ablations of biological tissue

Science.gov (United States)

Saccomandi, Paola; Varalda, Ambra; Gassino, Riccardo; Tosi, Daniele; Massaroni, Carlo; Caponero, Michele A.; Pop, Raoul; Korganbayev, Sanzhar; Perrone, Guido; Diana, Michele; Vallan, Alberto; Costamagna, Guido; Marescaux, Jacques; Schena, Emiliano

2017-09-01

The response of a fiber optic sensor [linearly chirped fiber Bragg grating (LCFBG)] to a linear thermal gradient applied on its sensing length (i.e., 1.5 cm) has been investigated. After these bench tests, we assessed their feasibility for temperature monitoring during thermal tumor treatment. In particular, we performed experiments during ex vivo laser ablation (LA) in pig liver and in vivo thermal ablation in animal models (pigs). We investigated the following: (i) the relationship between the full width at half maximum of the LCFBG spectrum and the temperature difference among the extremities of the LCFBG and (ii) the relationship between the mean spectrum wavelength and the mean temperature acting on the LCFBG sensing area. These relationships showed a linear trend during both bench tests and LA in animal models. Thermal sensitivity was significant although different values were found with regards to bench tests and animal experiments. The linear trend and significant sensitivity allow hypothesizing a future use of this kind of sensor to monitor both temperature gradient and mean temperature within a tissue undergoing thermal treatment.

Measuring surface temperature and grading pathological changes of airway tissue in a canine model of inhalational thermal injury.

Science.gov (United States)

Zhao, Ran; Di, La-na; Zhao, Xiao-zhuo; Wang, Cheng; Zhang, Guo-an

2013-06-01

Airway tissue shows unexpected invulnerability to heated air. The mechanisms of this phenomenon are open to debate. This study was designed to measure the surface temperatures at different locations of the airway, and to explore the relationship between the tissue's surface temperature and injury severity. Twenty dogs were randomly divided into four groups, including three experimental groups (six dogs in each) to inhale heated air at 70-80 °C (group I), 150-160 °C (group II) and 310-320 °C (group III) and a control group (two dogs, only for histological observation). Injury time was 20 min. Mucosal surface temperatures of the epiglottis (point A), cricoid cartilage (point B) and lower trachea (point C) were measured. Dogs in group I-III were divided into three subgroups (two in each), to be assayed at 12, 24 and 36 h after injury, respectively. For each dog, four tissue parts (epiglottis, larynx, lower trachea and terminal bronchiole) were microscopically observed and graded according to an original pathological scoring system (score range: 0-27). Surface temperatures of the airway mucosa increased slowly to 40.60±3.29 °C, and the highest peak temperature was 48.3 °C (group III, point A). The pathological score of burned tissues was 4.12±4.94 (0.0-18.0), suggesting slight to moderate injuries. Air temperature and airway location both influenced mucosal temperature and pathological scores very significantly, and there was a very significant positive correlation between tissue temperature and injury severity. Compared to the inhalational air hyperthermia, airway surface temperature was much lower, but was still positively correlated with thermal injury severity. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Vascular thermal adaptation in tumors and normal tissue in rats

International Nuclear Information System (INIS)

Nah, Byung Sik; Choi, Ihl-Bohng; Oh, Won Young; Osborn, James L.; Song, Chang W.

1996-01-01

Purpose: The vascular thermal adaptation in the R3230 adenocarcinoma, skin and muscle in the legs of Fischer rats was studied. Methods and Materials: The legs of Fischer rats bearing the R3230 AC adenocarcinoma (subcutaneously) were heated once or twice with a water bath, and the blood flow in the tumor, skin and muscle of the legs was measured with the radioactive microsphere method. Results: The blood flow in control R3230 AC tumors was 23.9 ml/100 g/min. The tumor blood flow increased about 1.5 times in 30 min and then markedly decreased upon heating at 44.5 deg. C for 90 min. In the tumors preheated 16 h earlier at 42.5 deg. C for 60 min, reheating at 44.5 deg. C increased the tumor blood flow by 2.5-fold in 30 min. Contrary to the decline in blood flow following an initial increase during the 44.5 deg. C heating without preheating, the tumor blood flow remained elevated throughout the 90 min reheating at 44.5 deg. C. These results indicated that thermal adaptation or thermotolerance developed in the tumor vasculatures after the preheating at 42.5 deg. C for 60 min. The magnitude of vascular thermal adaptation in the tumors 24 h and 48 h after the preheating, as judged from the changes in blood flow, were smaller than that 16 h after the preheating. Heating at 42.5 deg. C for 60 min induced vascular thermal adaptation also in the skin and muscle, which peaked in 48 h and 24 h, respectively, after the heating. Conclusion: Heating at 42.5 deg. C for 1 h induced vascular thermal adaptation in the R3230 AC tumor, skin, and muscle of rats that peaked 16-48 h after the heating. When the tumor blood vessels were thermally adapted, the tumor blood flow increased upon heating at temperatures that would otherwise reduce the tumor blood flow. Such an increase in tumor blood flow may hinder raising the tumor temperature while it may increase tumor oxygenation.

Supplementary feeding with thermally treated cereals in common carp (Cyprinus carpio L.) pond farming and its effects on water quality, nutrient budget and zooplankton and zoobenthos assemblages

Czech Academy of Sciences Publication Activity Database

Hlaváč, D.; Anton-Pardo, M.; Másílko, J.; Hartman, P.; Regenda, J.; Vejsada, P.; Baxa, M.; Pechar, L.; Valentová, O.; Všetičková, Lucie; Drozd, B.; Adámek, Z.

2016-01-01

Roč. 24, č. 6 (2016), s. 1681-1697 ISSN 0967-6120 Institutional support: RVO:68081766 Keywords : Common carp * Nutrient budget * Supplementary feeding * Thermally treated cereals Subject RIV: EH - Ecology, Behaviour Impact factor: 1.095, year: 2016

Effects of pressure rise on cw laser ablation of tissue

Science.gov (United States)

LeCarpentier, Gerald L.; Motamedi, Massoud; Welch, Ashley J.

1991-06-01

The objectives of this research were to identify mechanisms responsible for the initiation of continuous wave (cw) laser ablation of tissue and investigate the role of pressure in the ablation process. Porcine aorta samples were irradiated in a chamber pressurized from 1 X 10-4 to 12 atmospheres absolute pressure. Acrylic and Zn-Se windows in the experimental pressure chamber allowed video and infrared cameras to simultaneously record mechanical and thermal events associated with cw argon laser ablation of these samples. Video and thermal images of tissue slabs documented the explosive nature of cw laser ablation of soft biological media and revealed similar ablation threshold temperatures and ablation onset times under different environmental pressures; however, more violent initiation explosions with decreasing environmental pressures were observed. These results suggest that ablation initiates with thermal alterations in the mechanical strength of the tissue and proceeds with an explosion induced by the presence superheated liquid within the tissue.

Efficacy of curcumin to reduce hepatic damage induced by alcohol and thermally treated oil in rats

Directory of Open Access Journals (Sweden)

Nasr A.M.N. El-Deen

2010-03-01

Full Text Available The authors investigated the effect of curcumin on markers of oxidative stress and liver damage in rats that chronically ingested alcohol and heated oil. Nine groups of ten Wistar male rats received combinations of curcumin 100 mg/kg body weight daily, ethanol 5 mg/kg, 15% dietary sunflower oil and 15% heated sunflower oil for 12 weeks. Serum and liver tissue were collected. Groups 4-6, which had received compounds causing oxidative stress, showed increased serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, cholesterol, triglycerides, low density lipoprotein, very low density lipoprotein and reduced high density lipoprotein, protein and albumin, compared with the controls. Reductions were observed in glutathione peroxidase and reductase gene expression, superoxide dismutase activity, glutathione peroxidase activity, glutathione reductase activity, reduced glutathione concentration and catalase enzyme activity. Groups 7, 8 and 9 which received curcumin with heated oil, ethanol or both, showed lower elevations in serum and oxidative damage markers compared with the corresponding non-curcumin treated groups.It can be concluded that curcumin reduces markers of liver damage in rats treated with heated sunflower oil or ethanol.

Effects of edaravone on early outcomes in acute ischemic stroke patients treated with recombinant tissue plasminogen activator.

Science.gov (United States)

Wada, Tomoki; Yasunaga, Hideo; Inokuchi, Ryota; Horiguchi, Hiromasa; Fushimi, Kiyohide; Matsubara, Takehiro; Nakajima, Susumu; Yahagi, Naoki

2014-10-15

We investigated whether edaravone could improve early outcomes in acute ischemic stroke patients treated with recombinant tissue plasminogen activator (rtPA). We conducted a retrospective cohort study using the Japanese Diagnosis Procedure Combination database. We identified patients admitted with a primary diagnosis of ischemic stroke from 1 July 2010 to 31 March 2012 and treated with rtPA on the same day of stroke onset or the following day. Thereafter, we selected those who received edaravone on the same day of rtPA administration (edaravone group), and those who received rtPA without edaravone (control group). The primary outcomes were modified Rankin Scale (mRS) scores at discharge. One-to-one propensity-score matching was performed between the edaravone and control groups. An ordinal logistic regression analysis for mRS scores at discharge was performed with adjustment for possible variables as well as clustering of patients within hospitals using a generalized estimating equation. We identified 6336 eligible patients for inclusion in the edaravone group (n=5979; 94%) and the control group (n=357; 6%) as the total population. In 356 pairs of the propensity-matched population, the ordinal logistic regression analysis showed that edaravone was significantly associated with lower mRS scores of patients at discharge (adjusted odds ratio: 0.74; 95% confidence interval: 0.57-0.96). Edaravone may improve early outcomes in acute ischemic stroke patients treated with rtPA. Copyright © 2014 Elsevier B.V. All rights reserved.

HIV DNA Is Frequently Present within Pathologic Tissues Evaluated at Autopsy from Combined Antiretroviral Therapy-Treated Patients with Undetectable Viral Loads.

Science.gov (United States)

Lamers, Susanna L; Rose, Rebecca; Maidji, Ekaterina; Agsalda-Garcia, Melissa; Nolan, David J; Fogel, Gary B; Salemi, Marco; Garcia, Debra L; Bracci, Paige; Yong, William; Commins, Deborah; Said, Jonathan; Khanlou, Negar; Hinkin, Charles H; Sueiras, Miguel Valdes; Mathisen, Glenn; Donovan, Suzanne; Shiramizu, Bruce; Stoddart, Cheryl A; McGrath, Michael S; Singer, Elyse J

2016-10-15

HIV infection treatment strategies have historically defined effectiveness through measuring patient plasma HIV RNA. While combined antiretroviral therapy (cART) can reduce plasma viral load (pVL) to undetectable levels, the degree that HIV is eliminated from other anatomical sites remains unclear. We investigated the HIV DNA levels in 229 varied autopsy tissues from 20 HIV-positive (HIV(+)) cART-treated study participants with low or undetectable plasma VL and cerebrospinal fluid (CSF) VL prior to death who were enrolled in the National Neurological AIDS Bank (NNAB) longitudinal study and autopsy cohort. Extensive medical histories were obtained for each participant. Autopsy specimens, including at least six brain and nonbrain tissues per participant, were reviewed by study pathologists. HIV DNA, measured in tissues by quantitative and droplet digital PCR, was identified in 48/87 brain tissues and 82/142 nonbrain tissues at levels >200 HIV copies/million cell equivalents. No participant was found to be completely free of tissue HIV. Parallel sequencing studies from some tissues recovered intact HIV DNA and RNA. Abnormal histological findings were identified in all participants, especially in brain, spleen, lung, lymph node, liver, aorta, and kidney. All brain tissues demonstrated some degree of pathology. Ninety-five percent of participants had some degree of atherosclerosis, and 75% of participants died with cancer. This study assists in characterizing the anatomical locations of HIV, in particular, macrophage-rich tissues, such as the central nervous system (CNS) and testis. Additional studies are needed to determine if the HIV recovered from tissues promotes the pathogenesis of inflammatory diseases, such as HIV-associated neurocognitive disorders, cancer, and atherosclerosis. It is well-known that combined antiretroviral therapy (cART) can reduce plasma HIV to undetectable levels; however, cART cannot completely clear HIV infection. An ongoing question is

[A case of mucosa-associated lymphoid tissue lymphoma with penicillin allergy successfully treated with levofloxacin, minomycin and rabeprazole].

Science.gov (United States)

Konno, Tomoko; Motoori, Shigeatsu; Iwamoto, Nozomi; Miyazawa, Tomoe; Saito, Shigeyo; Kitagawa, Naoko; Saisho, Hiromitsu; Furuse, Junji; Itabashi, Masayuki

2010-10-01

A 52-year-old Japanese woman was referred to our Institute because of Helicobacter pylori(H. pylori)-positive gastric mucosa-associated lymphoid tissue(MALT)lymphoma. Since she had a penicillin allergy, we could not eradicate H. pylori using the standard triple therapy including amoxicillin. Additionally, H. pylori was resistant to both clarithromycin and metronidazole. So she was treated with minomycin (MINO), levofloxacin (LVFX), and rabeprazole (RPZ) based on a drug sensitivity test. MINO+LVFX+RPZ appear to be a promising, appropriate, and well-tolerated eradication regimen for H. pylori demonstrating resistance to both clarithromycin and metronidazole, and for patients who are allergic to penicillin.

Photothermal lesions in soft tissue induced by optical fiber microheaters.

Science.gov (United States)

Pimentel-Domínguez, Reinher; Moreno-Álvarez, Paola; Hautefeuille, Mathieu; Chavarría, Anahí; Hernández-Cordero, Juan

2016-04-01

Photothermal therapy has shown to be a promising technique for local treatment of tumors. However, the main challenge for this technique is the availability of localized heat sources to minimize thermal damage in the surrounding healthy tissue. In this work, we demonstrate the use of optical fiber microheaters for inducing thermal lesions in soft tissue. The proposed devices incorporate carbon nanotubes or gold nanolayers on the tips of optical fibers for enhanced photothermal effects and heating of ex vivo biological tissues. We report preliminary results of small size photothermal lesions induced on mice liver tissues. The morphology of the resulting lesions shows that optical fiber microheaters may render useful for delivering highly localized heat for photothermal therapy.

Photobiomodulation with non-thermal lasers: Mechanisms of action and therapeutic uses in dermatology and aesthetic medicine.

Science.gov (United States)

Nestor, Mark; Andriessen, Anneke; Berman, Brian; Katz, Bruce E; Gilbert, Dore; Goldberg, David J; Gold, Michael H; Kirsner, Robert S; Lorenc, Paul Z

2017-08-01

Non-thermal laser therapy in dermatology, is a growing field in medical technology by which therapeutic effects are achieved by exposing tissues to specific wavelengths of light. The purpose of this review was to gain a better understanding of the science behind non-thermal laser and the evidence supporting its use in dermatology. A group of dermatologists and surgeons recently convened to review the evidence supporting the use of non-thermal laser for body sculpting, improving the appearance of cellulite, and treating onychomycosis. The use of non-thermal laser for body sculpting is supported by three randomized, double-blind, sham-controlled studies (N = 161), one prospective open-label study (N = 54), and two retrospective studies (N = 775). Non-thermal laser application for improving the appearance of cellulite is supported by one randomized, double-blind, sham-controlled study (N = 38). The use of non-thermal laser for the treatment of onychomycosis is supported by an analysis of three non-randomized, open-label studies demonstrating clinical improvement of nails (N = 292). Non-thermal laser is steadily moving into mainstream medical practice, such as dermatology. Although present studies have demonstrated the safety and efficacy of non-thermal laser for body sculpting, cellulite reduction and onychomycosis treatment, studies demonstrating the efficacy of non-thermal laser as a stand-alone procedure are still inadequate.

Preliminary development of thermal nuclear cell homogenization code

International Nuclear Information System (INIS)

Su'ud, Z.; Shafii, M. A.; Yudha, S. P.; Waris, A.; Rijal, K.

2012-01-01

Nuclear fuel cell homogenization for thermal reactors usually include three main parts, i.e., fast energy resonance part which usually adopt narrow resonance approximation to treat the resonance, low (intermediate) energy region in which the resonance can not be treated accurately using NR approximation and therefore we should use intermediate resonance treatment, and thermal energy region (very low) in which the effect of thermal must be treated properly. In n this study the application of the intermediate resonance approximation treatment for low energy nuclear resonance is discussed. The method is iterative based. As a sample the method is applied in U-235 low lying resonance and the result is presented and discussed.

Flavor characterization of sugar-added pennywort (Centella asiatica L.) juices treated with ultra-high pressure and thermal processes.

Science.gov (United States)

Apichartsrangkoon, Arunee; Wongfhun, Pronprapa; Gordon, Michael H

2009-01-01

The flavor characteristics of pennywort juices with added sugar treated by ultra-high pressure, pasteurization, and sterilization were investigated using solid phase microextraction combined with gas chromatography-mass spectrometry. It was found that sesquiterpene hydrocarbons comprised the major class of volatile components present and the juices had a characteristic aroma due to the presence of volatiles including beta-caryophyllene and humulene and alpha-copaene. In comparison with heated juices, HPP-treated samples could retain more volatile compounds such as linalool and geraniol similar to those present in fresh juice, whereas some volatiles such as alpha-terpinene and ketone class were apparently formed by thermal treatment. All processing operations produced juice that was not significantly different in the concentration of total volatiles. Practical Application: Pennywort juice is considered a nutraceutical drink for health benefits. Therefore, to preserve all aroma and active components in this juice, a nonthermal process such as ultra-high pressure should be a more appropriate technique for retention of its nutritive values than pasteurization and sterilization.

Irbesartan increased PPARγ activity in vivo in white adipose tissue of atherosclerotic mice and improved adipose tissue dysfunction

International Nuclear Information System (INIS)

Iwai, Masaru; Kanno, Harumi; Senba, Izumi; Nakaoka, Hirotomo; Moritani, Tomozo; Horiuchi, Masatsugu

2011-01-01

Research highlights: → Atherosclerotic apolipoprotein E-deficient (ApoEKO) mice were treated with irbesartan. → Irbesartan decreased white adipose tissue weight without affecting body weight. → DNA-binding for PPARγ was increased in white adipose tissue in vivo by irbesartan. → Irbesartan increased adipocyte number in white adipose tissue. → Irbesatan increased the expression of adiponectin and leptin in white adipose tissue. -- Abstract: The effect of the PPARγ agonistic action of an AT 1 receptor blocker, irbesartan, on adipose tissue dysfunction was explored using atherosclerotic model mice. Adult male apolipoprotein E-deficient (ApoEKO) mice at 9 weeks of age were treated with a high-cholesterol diet (HCD) with or without irbesartan at a dose of 50 mg/kg/day for 4 weeks. The weight of epididymal and retroperitoneal adipose tissue was decreased by irbesartan without changing food intake or body weight. Treatment with irbesartan increased the expression of PPARγ in white adipose tissue and the DNA-binding activity of PPARγ in nuclear extract prepared from adipose tissue. The expression of adiponectin, leptin and insulin receptor was also increased by irbesartan. These results suggest that irbesartan induced activation of PPARγ and improved adipose tissue dysfunction including insulin resistance.

Understanding the effect of pulsed electric fields on thermostability of connective tissue isolated from beef pectoralis muscle using a model system.

Science.gov (United States)

Alahakoon, A U; Oey, I; Silcock, P; Bremer, P

2017-10-01

Brisket is a low value/tough meat cut that contains a large amount of connective tissue. Conversion of collagen into gelatin during heating reduces the toughness of the connective tissue however this conversion is slow at low cooking temperatures (around 60°C). The objective of this project was to determine the ability of pulsed electric field (PEF) processing to reduce the thermal stability of connective tissue. To achieve this, a novel model system was designed in which connective tissue obtained from beef deep pectotalis muscle (brisket) was exposed to PEF at combinations of electric field strength (1.0 and 1.5kV/cm) and specific energy (50 and 100kJ/kg) within an agar matrix at electrical conductivities representing the electrical conductivity found in brisket. Differential scanning calorimetry showed that PEF treatment significantly (pconnective tissue compared to untreated samples. Increasing electric field strength and the specific energy increased the Ringer soluble collagen fraction. PEF treated samples showed higher solubilization compared to the untreated samples at both 60°C and 70°C in heat solubility test. SEM examination of PEF treated (at 1.5kV/cm and 100kJ/kg) and untreated samples revealed that PEF appeared to increase the porosity of the connective tissue structure. These finding suggest that PEF processing is a technology that could be used to improve the tenderness and decrease the cooking time of collagen rich, meat cuts. Copyright © 2017 Elsevier Ltd. All rights reserved.

ICG-assisted blood vessel detection during stereotactic neurosurgery: simulation study on excitation power limitations due to thermal effects in human brain tissue.

Science.gov (United States)

Rühm, Adrian; Göbel, Werner; Sroka, Ronald; Stepp, Herbert

2014-09-01

Intraoperative blood vessel detection based on intraluminal indocyanin-green (ICG) would allow to minimize the risk of blood vessel perforation during stereotactic brain tumor biopsy. For a fiber-based approach compatible with clinical conditions, the maximum tolerable excitation light power was derived from simulations of the thermal heat load on the tissue. Using the simulation software LITCIT, the temperature distribution in human brain tissue was calculated as a function of time for realistic single-fiber probes (0.72mm active diameter, numerical aperture 0.35, optional focusing to 0.29mm diameter) and for the optimum ICG excitation wavelength of 785nm. The asymptotic maximum temperature in the simulated tissue region was derived for different radiant fluxes at the distal fiber end. Worst case values were assumed for all other parameters. In addition to homogeneous (normal and tumor) brain tissue with homogeneous blood perfusion, models with localized extra blood vessels incorporated ahead of the distal fiber end were investigated. If one demands that destruction of normal brain tissue must be excluded by limiting the tissue heating to 42°C, then the radiant flux at the distal fiber end must be limited to 33mW with and 43mW without focusing. When considering extra blood vessels of 0.1mm diameter incorporated into homogeneously perfused brain tissue, the tolerable radiant flux is reduced to 22mW with and 32mW without focusing. The threshold value according to legal laser safety regulations for human skin tissue is 28.5mW. For the envisaged modality of blood vessel detection, light power limits for an application-relevant fiber configuration were determined and found to be roughly consistent with present legal regulations for skin tissue. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of some wood preservatives on the thermal degradation of Scots pine

International Nuclear Information System (INIS)

Tomak, Eylem D.; Baysal, Ergun; Peker, Huseyin

2012-01-01

Highlights: ► Scots pine samples were impregnated with 10 commercial wood preservatives. ► Thermal degradation of wood was evaluated by TG, DTG and DTA. ► The thermal behavior of treated wood differed from that of untreated wood. ► Boron containing wood preservatives yielded more charcoal than other preservatives. ► Boric oxide and metal compounds in the formulations may affect char weight. - Abstract: Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effectiveness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups.

Tissue photoablation process with short-pulsed lasers

Science.gov (United States)

Mueller, Gerhard J.; Doerschel, Klaus; Kar, Hasan

1992-03-01

Since Hippocrates, physicians have three weapons to fight malignant diseases of the human body: Quae medicamenta non sanat, ferrum sanat; quae ferrum non sanat, ignis sanat; and quae vero ignis non sanat, insanabilia reputari oportet. Today there are various possibilities to use the ''fire'': electrical and optical cauterization; mono- and bipolar rf-surgery; ionizing radiation for tumor treatment; and last but not least, the laser of laser tissue interactions, all can be used to remove malignant tissue either by biological digestion or immediate ablation, i.e., photovaporization or photodecomposition. This paper will discuss a semiempirical theory of the so-called photoablation process and the thermal side effects of the surrounding tissue. The term ''Photoablation; has to be well differentiated with the terms photovaporization, photodisruption and photofragmentation. As will be shown in this paper, photoablation is a microscale fast thermal explosion.

Uric acid therapy improves the outcomes of stroke patients treated with intravenous tissue plasminogen activator and mechanical thrombectomy.

Science.gov (United States)

Chamorro, Ángel; Amaro, Sergio; Castellanos, Mar; Gomis, Meritxell; Urra, Xabier; Blasco, Jordi; Arenillas, Juan F; Román, Luis S; Muñoz, Roberto; Macho, Juan; Cánovas, David; Marti-Fabregas, Joan; Leira, Enrique C; Planas, Anna M

2017-06-01

Background Numerous neuroprotective drugs have failed to show benefit in the treatment of acute ischemic stroke, making the search for new treatments imperative. Uric acid is an endogenous antioxidant making it a drug candidate to improve stroke outcomes. Aim To report the effects of uric acid therapy in stroke patients receiving intravenous thrombolysis and mechanical thrombectomy. Methods Forty-five patients with proximal vessel occlusions enrolled in the URICO-ICTUS trial received intravenous recombinant tissue plasminogen activator within 4.5 h after stroke onset and randomized to intravenous 1000 mg uric acid or placebo (NCT00860366). These patients also received mechanical thrombectomy because a brain computed tomogaphy angiography confirmed the lack of proximal recanalization at the end of systemic thrombolysis. The primary outcome was good functional outcome at 90 days (modified Rankin Score 0-2). Safety outcomes included mortality, symptomatic intracerebral bleeding, and gout attacks. Results The rate of successful revascularization was >80% in the uric acid and the placebo groups but good functional outcome was observed in 16 out of 24 (67%) patients treated with uric acid and 10 out of 21 (48%) treated with placebo (adjusted Odds Ratio, 6.12 (95% CI 1.08-34.56)). Mortality was observed in two out of 24 (8.3%) patients treated with uric acid and one out of 21 (4.8%) treated with placebo (adjusted Odds Ratio, 3.74 (95% CI 0.06-226.29)). Symptomatic cerebral bleeding and gout attacks were similar in both groups. Conclusions Uric acid therapy was safe and improved stroke outcomes in stroke patients receiving intravenous thrombolysis followed by thrombectomy. Validation of this simple strategy in a larger trial is urgent.

Thermal shock effect on Mechanical and Physical properties of pre-moisture treated GRE composite

Science.gov (United States)

Chakraverty, A. P.; Panda, A. B.; Mohanty, U. K.; Mishra, S. C.; Biswal, B. B.

2018-03-01

Many practical situations may be encountered under which a GFRP (Glass fibre reinforced polymer) composite, during its service life, is exposed to the severities of sudden temperature fluctuations. Moisture absorption of GRE (Glass fibre reinforced epoxy) composites followed by various gradients of temperature fluctuations may cause thermo- mechanical degradation. It is on this context, the hand layed GRE composite samples are exposed to up-thermal shock (-40°C to +50°C) and down-thermal shock (+50°C to -40°C) for various time interval after several periods of moisture (hydrothermal/hygrothermal) conditioning. The thermally shocked GRE specimens are put to 3-point bend test to divulge inter laminar shear strength (ILSS). Least ILSS values are recorded for the samples with maximum period of moisture treatments under with both up-thermal and down-thermal shock conditions. Lower glass transition temperature (Tg) values, as revealed through the low temperature DSC test, are exhibited at maximum durations of both up-thermal and down-thermal shock for the samples with higher periods of hygrothermal/hydrothermal treatments. SEM fractographs of representative GRE specimens after optimum period of moisture treatments and thermal shock show the various modes of failures.

Bio-based polyurethane for tissue engineering applications: How hydroxyapatite nanoparticles influence the structure, thermal and biological behavior of polyurethane composites.

Science.gov (United States)

Gabriel, Laís P; Santos, Maria Elizabeth M Dos; Jardini, André L; Bastos, Gilmara N T; Dias, Carmen G B T; Webster, Thomas J; Maciel Filho, Rubens

2017-01-01

In this work, thermoset polyurethane composites were prepared by the addition of hydroxyapatite nanoparticles using the reactants polyol polyether and an aliphatic diisocyanate. The polyol employed in this study was extracted from the Euterpe oleracea Mart. seeds from the Amazon Region of Brazil. The influence of hydroxyapatite nanoparticles on the structure and morphology of the composites was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), the structure was evaluated by Fourier transform infrared spectroscopy (FT-IR), thermal properties were analyzed by thermogravimetry analysis (TGA), and biological properties were studied by in vitro and in vivo studies. It was found that the addition of HA nanoparticles promoted fibroblast adhesion while in vivo investigations with histology confirmed that the composites promoted connective tissue adherence and did not induce inflammation. In this manner, this study supports the further investigation of bio-based, polyurethane/hydroxyapatite composites as biocompatible scaffolds for numerous tissue engineering applications. Copyright © 2016 Elsevier Inc. All rights reserved.

Temperature measurement by thermal strain imaging with diagnostic power ultrasound, with potential for thermal index determination.

Science.gov (United States)

Liang, Hai-Dong; Zhou, Li-Xia; Wells, Peter N T; Halliwell, Michael

2009-05-01

Over the years, there has been a substantial increase in acoustic exposure in diagnostic ultrasound as new imaging modalities with higher intensities and frame rates have been introduced; and more electronic components have been packed into the probe head, so that there is a tendency for it to become hotter. With respect to potential thermal effects, including those which may be hazardous occurring during ultrasound scanning, there is a correspondingly growing need for in vivo techniques to guide the operator as to the actual temperature rise occurring in the examined tissues. Therefore, an in vivo temperature estimator would be of considerable practical value. The commonly-used method of tissue thermal index (TI) measurement with a hydrophone in water could underestimate the actual value of TI (in one report by as much as 2.9 times). To obtain meaningful results, it is necessary to map the temperature elevation in 2-D (or 3-D) space. We present methodology, results and validation of a 2-D spatial and temporal thermal strain ultrasound temperature estimation technique in phantoms, and its apparently novel application in tracking the evolution of heat deposition at diagnostic exposure levels. The same ultrasound probe is used for both transmission and reception. The displacement and thermal strain estimation methods are similar to those used in high-intensity focused ultrasound thermal monitoring. The use of radiofrequency signals permits the application of cross correlation as a similarity measurement for tracking feature displacement. The displacement is used to calculate the thermal strain directly related to the temperature rise. Good agreement was observed between the temperature rise and the ultrasound power and scan duration. Thermal strain up to 1.4% was observed during 4000-s scan. Based on the results obtained for the temperature range studied in this work, the technique demonstrates potential for applicability in phantom (and possibly in vivo tissue

In situ spray deposition of cell-loaded, thermally and chemically gelling hydrogel coatings for tissue regeneration.

Science.gov (United States)

Pehlivaner Kara, Meryem O; Ekenseair, Adam K

2016-10-01

In this study, the efficacy of creating cellular hydrogel coatings on warm tissue surfaces through the minimally invasive, sprayable delivery of thermoresponsive liquid solutions was investigated. Poly(N-isopropylacrylamide)-based (pNiPAAm) thermogelling macromers with or without addition of crosslinking polyamidoamine (PAMAM) macromers were synthesized and used to produce in situ forming thermally and chemically gelling hydrogel systems. The effect of solution and process parameters on hydrogel physical properties and morphology was evaluated and compared to poly(ethylene glycol) and injection controls. Smooth, fast, and conformal hydrogel coatings were obtained when pNiPAAm thermogelling macromers were sprayed with high PAMAM concentration at low pressure. Cellular hydrogel coatings were further fabricated by different spraying techniques: single-stream, layer-by-layer, and dual stream methods. The impact of spray technique, solution formulation, pressure, and spray solution viscosity on the viability of fibroblast and osteoblast cells encapsulated in hydrogels was elucidated. In particular, the early formation of chemically crosslinked micronetworks during bulk liquid flow was shown to significantly affect cell viability under turbulent conditions compared to injectable controls. The results demonstrated that sprayable, in situ forming hydrogels capable of delivering cell populations in a homogeneous therapeutic coating on diseased tissue surfaces offer promise as novel therapies for applications in regenerative medicine. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2383-2393, 2016. © 2016 Wiley Periodicals, Inc.

Pressure-assisted thermal sterilization of soup

Science.gov (United States)

Shibeshi, Kidane; Farid, Mohammed M.

2010-12-01

The overall efficiency of an existing scale-up pressure-assisted thermal sterilization (PATS) unit was investigated with regards to inactivation of Geobacillus stearothermophilus spores suspended in pumpkin soup. The PATS unit is a double pipe heat exchanger in which the soup is pumped into its inner high pressure tube and constrained by two high pressure valves, while steam is continuously passed through the annular region to heat the content. The technology is based on pressure generation by thermal expansion of the liquid in an enclosure. In this work, the addition of an air line to push the treated liquid food out of the existing PATS unit has improved the overall quality of the treated samples, as evidenced by achieving higher log reduction of the spores. Compared with thermal processing, the application of PATS shows the potential for lowering the thermal treatment temperature, offering improved food quality.

The effect of some wood preservatives on the thermal degradation of Scots pine

Energy Technology Data Exchange (ETDEWEB)

Tomak, Eylem D., E-mail: eylemdizman@yahoo.com [Karadeniz Technical University, Faculty of Forestry, Forest Industrial Engineering Department, 61080 Trabzon (Turkey); Baysal, Ergun, E-mail: bergun@mu.edu.tr [Mugla University, Faculty of Technology, Department of Wood Science and Technology, Kotekli, 48000 Mugla (Turkey); Peker, Huseyin, E-mail: peker100@hotmail.com [Artvin Coruh University, Faculty of Forestry, Forest Industrial Engineering Department, 06100 Artvin (Turkey)

2012-11-10

Highlights: Black-Right-Pointing-Pointer Scots pine samples were impregnated with 10 commercial wood preservatives. Black-Right-Pointing-Pointer Thermal degradation of wood was evaluated by TG, DTG and DTA. Black-Right-Pointing-Pointer The thermal behavior of treated wood differed from that of untreated wood. Black-Right-Pointing-Pointer Boron containing wood preservatives yielded more charcoal than other preservatives. Black-Right-Pointing-Pointer Boric oxide and metal compounds in the formulations may affect char weight. - Abstract: Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effectiveness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups.

SDF-1 improves wound healing ability of glucocorticoid-treated adipose tissue-derived mesenchymal stem cells.

Science.gov (United States)

Kato, Toshiki; Khanh, Vuong Cat; Sato, Kazutoshi; Takeuchi, Kosuke; Carolina, Erica; Yamashita, Toshiharu; Sugaya, Hisashi; Yoshioka, Tomokazu; Mishima, Hajime; Ohneda, Osamu

2017-11-18

Glucocorticoids cause the delayed wound healing by suppressing inflammation that is required for wound healing process. Adipose tissue-derived mesenchymal stem cells (AT-MSCs) play an important role for wound healing by their cytokine productions including stromal derived factor 1 (SDF-1). However, it has not been clear how glucocorticoids affect the wound healing ability of AT-MSCs. In this study, we found that glucocorticoid downregulated SDF-1 expression in AT-MSCs. In addition, glucocorticoid-treated AT-MSCs induced less migration of inflammatory cells and impaired wound healing capacity compared with glucocorticoid-untreated AT-MSCs. Of note, prostaglandin E2 (PGE2) synthesis-related gene expression was downregulated by glucocorticoid and PGE2 treatment rescued not only SDF-1 expression in the presence of glucocorticoid but also their wound healing capacity in vivo. Furthermore, we found SDF-1-overexpressed AT-MSCs restored wound healing capacity even after treatment of glucocorticoid. Consistent with the results obtained from glucocorticoid-treated AT-MSCs, we found that AT-MSCs isolated from steroidal osteonecrosis donors (sAT-MSCs) who received chronic glucocorticoid therapy showed less SDF-1 expression and impaired wound healing capacity compared with traumatic osteonecrosis donor-derived AT-MSCs (nAT-MSCs). Moreover, the SDF-1 level was also reduced in plasma derived from steroidal osteonecrosis donors compared with traumatic osteonecrosis donors. These results provide the evidence that concomitant application of AT-MSCs with glucocorticoid shows impaired biological modulatory effects that induce impaired wound healing. Copyright © 2017 Elsevier Inc. All rights reserved.

Microscopic View of Defect Evolution in Thermal Treated AlGaInAs Quantum Well Revealed by Spatially Resolved Cathodoluminescence

Directory of Open Access Journals (Sweden)

Yue Song

2018-06-01

Full Text Available An aluminum gallium indium arsenic (AlGaInAs material system is indispensable as the active layer of diode lasers emitting at 1310 or 1550 nm, which are used in optical fiber communications. However, the course of the high-temperature instability of a quantum well structure, which is closely related to the diffusion of indium atoms, is still not clear due to the system’s complexity. The diffusion process of indium atoms was simulated by thermal treatment, and the changes in the optical and structural properties of an AlGaInAs quantum well are investigated in this paper. Compressive strained Al0.07Ga0.22In0.71As quantum wells were treated at 170 °C with different heat durations. A significant decrement of photoluminescence decay time was observed on the quantum well of a sample that was annealed after 4 h. The microscopic cathodoluminescent (CL spectra of these quantum wells were measured by scanning electron microscope-cathodoluminescence (SEM-CL. The thermal treatment effect on quantum wells was characterized via CL emission peak wavelength and energy density distribution, which were obtained by spatially resolved cathodoluminescence. The defect area was clearly observed in the Al0.07Ga0.22In0.71As quantum wells layer after thermal treatment. CL emissions from the defect core have higher emission energy than those from the defect-free regions. The defect core distribution, which was associated with indium segregation gradient distribution, showed asymmetric character.

Performance Enhancement of Silicon Alloy-Based Anodes Using Thermally Treated Poly(amide imide) as a Polymer Binder for High Performance Lithium-Ion Batteries.

Science.gov (United States)

Yang, Hwi Soo; Kim, Sang-Hyung; Kannan, Aravindaraj G; Kim, Seon Kyung; Park, Cheolho; Kim, Dong-Won

2016-04-05

The development of silicon-based anodes with high capacity and good cycling stability for next-generation lithium-ion batteries is a very challenging task due to the large volume changes in the electrodes during repeated cycling, which results in capacity fading. In this work, we synthesized silicon alloy as an active anode material, which was composed of silicon nanoparticles embedded in Cu-Al-Fe matrix phases. Poly(amide imide)s, (PAI)s, with different thermal treatments were used as polymer binders in the silicon alloy-based electrodes. A systematic study demonstrated that the thermal treatment of the silicon alloy electrodes at high temperature made the electrodes mechanically strong and remarkably enhanced the cycling stability compared to electrodes without thermal treatment. The silicon alloy electrode thermally treated at 400 °C initially delivered a discharge capacity of 1084 mAh g(-1) with good capacity retention and high Coulombic efficiency. This superior cycling performance was attributed to the strong adhesion of the PAI binder resulting from enhanced secondary interactions, which maintained good electrical contacts between the active materials, electronic conductors, and current collector during cycling. These findings are supported by results from X-ray photoelectron spectroscopy, scanning electron microscopy, and a surface and interfacial cutting analysis system.

The effect of the shape and size of gold seeds irradiated with ultrasound on the bio-heat transfer in tissue.

Science.gov (United States)

Gkigkitzis, Ioannis; Austerlitz, Carlos; Haranas, Ioannis; Campos, Diana

2015-01-01

The aim of this report is to propose a new methodology to treat prostate cancer with macro-rod-shaped gold seeds irradiated with ultrasound and develop a new computational method for temperature and thermal dose control of hyperthermia therapy induced by the proposed procedure. A computer code representation, based on the bio-heat diffusion equation, was developed to calculate the heat deposition and temperature elevation patterns in a gold rod and in the tissue surrounding it as a result of different therapy durations and ultrasound power simulations. The numerical results computed provide quantitative information on the interaction between high-energy ultrasound, gold seeds and biological tissues and can replicate the pattern observed in experimental studies. The effect of differences in shapes and sizes of gold rod targets irradiated with ultrasound is calculated and the heat enhancement and the bio-heat transfer in tissue are analyzed.

Model of optical phantoms thermal response upon irradiation with 975 nm dermatological laser

Science.gov (United States)

Wróbel, M. S.; Bashkatov, A. N.; Yakunin, A. N.; Avetisyan, Yu. A.; Genina, E. A.; Galla, S.; Sekowska, A.; Truchanowicz, D.; Cenian, A.; Jedrzejewska-Szczerska, M.; Tuchin, V. V.

2018-04-01

We have developed a numerical model describing the optical and thermal behavior of optical tissue phantoms upon laser irradiation. According to our previous studies, the phantoms can be used as substitute of real skin from the optical, as well as thermal point of view. However, the thermal parameters are not entirely similar to those of real tissues thus there is a need to develop mathematical model, describing the thermal and optical response of such materials. This will facilitate the correction factors, which would be invaluable in translation between measurements on skin phantom to real tissues, and gave a good representation of a real case application. Here, we present the model dependent on the data of our optical phantoms fabricated and measured in our previous preliminary study. The ambiguity between the modeling and the thermal measurements depend on lack of accurate knowledge of material's thermal properties and some exact parameters of the laser beam. Those parameters were varied in the simulation, to provide an overview of possible parameters' ranges and the magnitude of thermal response.

Three-dimensional bioprinting in tissue engineering and regenerative medicine.

Science.gov (United States)

Gao, Guifang; Cui, Xiaofeng

2016-02-01

With the advances of stem cell research, development of intelligent biomaterials and three-dimensional biofabrication strategies, highly mimicked tissue or organs can be engineered. Among all the biofabrication approaches, bioprinting based on inkjet printing technology has the promises to deliver and create biomimicked tissue with high throughput, digital control, and the capacity of single cell manipulation. Therefore, this enabling technology has great potential in regenerative medicine and translational applications. The most current advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review, including vasculature, muscle, cartilage, and bone. In addition, the benign side effect of bioprinting to the printed mammalian cells can be utilized for gene or drug delivery, which can be achieved conveniently during precise cell placement for tissue construction. With layer-by-layer assembly, three-dimensional tissues with complex structures can be printed using converted medical images. Therefore, bioprinting based on thermal inkjet is so far the most optimal solution to engineer vascular system to the thick and complex tissues. Collectively, bioprinting has great potential and broad applications in tissue engineering and regenerative medicine. The future advances of bioprinting include the integration of different printing mechanisms to engineer biphasic or triphasic tissues with optimized scaffolds and further understanding of stem cell biology.

Thermally promoted addition of undecylenic acid on thermally hydrocarbonized porous silicon optical reflectors

OpenAIRE

Jalkanen, Tero; Mäkilä, Ermei; Sakka, Tetsuo; Salonen, Jarno; Ogata, Yukio H

2012-01-01

Thermally promoted addition of undecylenic acid is studied as a method for modifying porous silicon optical reflectors that have been pre-treated with thermal hydrocarbonization. Successful derivatization of undecylenic acid is demonstrated and confirmed with Fourier transform infrared and X-ray photoelectron spectroscopies. The results indicate that the hydrocarbonization pre-treatment considerably improves stability against oxidation and chemical dissolution in basic environments. The two-s...

Tissue banking for management of nuclear casualties

International Nuclear Information System (INIS)

Singh, Rita

2014-01-01

The proliferation of nuclear material and technology has made the acquisition and adversarial use more probable than ever. Devastating medical consequences would follow a nuclear detonation due to the thermal, blast and radiation effects of the weapon. Atomic explosions at Hiroshima and Nagasaki demonstrated the human agonies on vast scale. A full range of medical modalities are required to decrease the morbidity and mortality as a result of the use of nuclear weapons. Biological tissues from human donor like bone, skin, amniotic membrane and other soft tissues can be used for repair or reconstruction of the injured part of the body. Tissues from human donor can be processed and banked for orthopaedic, spinal, trauma and other surgical procedures. Processed tissues can be provided by the tissue banks and can be of great assistance in the treatment of injuries due to the nuclear weapon. The use of allograft tissue avoids the donor site morbidity and reduces the operating time, expense and trauma associated with the acquisition of autografts. Further, allografts have the added advantage of being available in large quantities. This has led to a global increase in allogeneic transplantation and development of tissue banking. The aim of the tissue bank is to provide a wide range of processed biological tissues free from any transmissible disease, that help to restore the growth and function of the damaged tissues. Skin dressings or skin substitutes like allograft skin, xenograft skin and amniotic membrane can be used for the treatment of thermal burns and radiation induced skin injuries. Bone allografts can be used for reconstructive approaches to the skeletal system. Tissue banking would thus ensure health care to the military personnel and population following a nuclear detonation. (author)

Neutron activation analysis of trace elements in biological tissue

Energy Technology Data Exchange (ETDEWEB)

Velandia, J A; Perkons, A K

1974-01-01

Thermal Neutron Activation Analysis with Instrumental Ge(Li) Gamma Spectrometry was used to determine the amounts of more than 30 trace constituents in heart tissue of rats and kidney tissue of rabbits. The results were confirmed by a rapid ion-exchange group separation method in the initial stages of the experiments. The samples were exposed to thermal neutrons for periods between 3 minutes and 14 hours. Significant differences in the amounts and types of trace elements in the two different tissue types are apparent, however, are probably due to specific diets. Tables of relevant nuclear data, standard concentrations, radiochemical separation recoveries, and quantitative analytical results are presented. The ion-exchange group separation scheme and typical examples of the instrumental gamma ray spectra are shown. The techniques developed in this study are being used for a large scale constituent survey of various diseased and healthy human tissues.

Polyploidy Analysis and Attenuation of Oxidative Stress in Hepatic Tissue of STZ-Induced Diabetic Rats Treated with an Aqueous Extract of Vochysia rufa

Directory of Open Access Journals (Sweden)

Izabela Barbosa Moraes

2015-01-01

Full Text Available Diabetes mellitus (DM is characterized by hyperglycemia and alterations in the metabolism of lipids, carbohydrates, and proteins. Due to its hypoglycemic effect Vochysia rufa is frequently used in Uberlandia, Brazil, to treat DM. Despite its popularity, there is little information about its effect on hepatic tissue. Therefore, we evaluated the histoarchitecture, oxidative stress parameters, and polyploidy of liver tissue from streptozotocin- (STZ- induced diabetic rats treated with aqueous extract of Vochysia rufa (AEV. Histology was determined by fixing the livers, processing, and staining with HE. Oxidative stress was determined by evaluating CAT, GPx, and SOD activity in liver homogenates and hepatic mitochondria fraction and by measuring GST, GSH levels and lipid peroxidation (MDA. Polyploidy was determined by subjecting isolated hepatocyte nuclei to flow cytometry. In the diabetic group, GST activity and GSH rates decreased whereas liver homogenate analysis showed that GPx, SOD activity and MDA increased. AEV treatment restored all parameters to normal levels. The oxidative stress analysis of hepatic mitochondria fraction showed similar results. Lower polyploid cell populations were found in the diabetic rat livers, even after glibenclamide treatment. Thus, AEV treatment efficiently reduced hepatic oxidative stress caused by STZ-induced diabetes and produced no morphological changes in the histological analysis.

Induced thermal resistance in the mouse ear

International Nuclear Information System (INIS)

Law, M.P.; Coultas, P.G.; Field, S.B.

1979-01-01

The mouse ear (pinna) was used to investigate the effect of two hyperthermic treatments. Heating was by immersion in hot water at 43.5 0 C. A single treatment of about 50 minutes was required to cause necrosis in 50% of the ears treated. When heat treatment was given in two equal fractions the total heating time had to be increased if the interval between fractions was greater than four hours. By 24 hours a total treatment of about 100 minutes was required, indicating almost complete recovery from the first heating. Priming treatments at 43.5 0 C induced thermal resistance to a second heat treatment at 43.5 0 C. Maximum resistance was observed one day after a 20 minute priming and two days after a 40 minute priming, when the heating time had to be increased to 120 minutes, an increase by a factor of 2.4. Shorter priming treatments induced less resistance, the minimum heating time to produce an effect being two minutes. In all cases the effect decreased during the next four to five days. These results indicate that the reduced response of tissues to fractionated hyperthermia is due both to the repair of sublethal heat damage and induction of thermal resistance. (author)

Prognostic Value of Cardiac Time Intervals by Tissue Doppler Imaging M-Mode in Patients With Acute ST-Segment-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

DEFF Research Database (Denmark)

Biering-Sørensen, Tor; Mogelvang, Rasmus; Søgaard, Peter

2013-01-01

Background- Color tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to estimate all cardiac time intervals from 1 cardiac cycle and thereby obtain the myocardial performance index (MPI). However, the prognostic value of the cardiac time intervals and the MPI...... assessed by color tissue Doppler imaging M-mode through the mitral leaflet in patients with ST-segment-elevation myocardial infarction (MI) is unknown. Methods and Results- In total, 391 patients were admitted with an ST-segment-elevation MI, treated with primary percutaneous coronary intervention...

Irbesartan increased PPAR{gamma} activity in vivo in white adipose tissue of atherosclerotic mice and improved adipose tissue dysfunction

Energy Technology Data Exchange (ETDEWEB)

Iwai, Masaru; Kanno, Harumi; Senba, Izumi; Nakaoka, Hirotomo; Moritani, Tomozo [Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University Graduate School of Medicine, Shitsukawa, Tohon, Ehime 791-0295 (Japan); Horiuchi, Masatsugu, E-mail: horiuchi@m.ehime-u.ac.jp [Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University Graduate School of Medicine, Shitsukawa, Tohon, Ehime 791-0295 (Japan)

2011-03-04

Research highlights: {yields} Atherosclerotic apolipoprotein E-deficient (ApoEKO) mice were treated with irbesartan. {yields} Irbesartan decreased white adipose tissue weight without affecting body weight. {yields} DNA-binding for PPAR{gamma} was increased in white adipose tissue in vivo by irbesartan. {yields} Irbesartan increased adipocyte number in white adipose tissue. {yields} Irbesatan increased the expression of adiponectin and leptin in white adipose tissue. -- Abstract: The effect of the PPAR{gamma} agonistic action of an AT{sub 1} receptor blocker, irbesartan, on adipose tissue dysfunction was explored using atherosclerotic model mice. Adult male apolipoprotein E-deficient (ApoEKO) mice at 9 weeks of age were treated with a high-cholesterol diet (HCD) with or without irbesartan at a dose of 50 mg/kg/day for 4 weeks. The weight of epididymal and retroperitoneal adipose tissue was decreased by irbesartan without changing food intake or body weight. Treatment with irbesartan increased the expression of PPAR{gamma} in white adipose tissue and the DNA-binding activity of PPAR{gamma} in nuclear extract prepared from adipose tissue. The expression of adiponectin, leptin and insulin receptor was also increased by irbesartan. These results suggest that irbesartan induced activation of PPAR{gamma} and improved adipose tissue dysfunction including insulin resistance.

Fe-catalyzed thermal conversion of sodium lignosulfonate to graphene

Science.gov (United States)

Sung Phil Mun; Zhiyong Cai; Jilei Zhang

2013-01-01

Sodium lignosulfonate (LS) from sulfite pulping processing was used as a carbon source to synthesize graphene. LS was mixed with Fe nanoparticles (FeNPs) as a catalyst and thermally treated at 1000 °C for 1 h. The Raman spectrum and X-ray diffraction pattern suggested that graphene sheets were formed in LS thermally treated with FeNPs (Fe-HTLS). Scanning...

Time-dependent change of blood flow in the prostate treated with high-intensity focused ultrasound.

Science.gov (United States)

Shoji, Sunao; Tonooka, Akiko; Hashimoto, Akio; Nakamoto, Masahiko; Tomonaga, Tetsuro; Nakano, Mayura; Sato, Haruhiro; Terachi, Toshiro; Koike, Junki; Uchida, Toyoaki

2014-09-01

Avascular areas on contrast-enhanced magnetic resonance imaging have been considered to be areas of localized prostate cancer successfully treated by high-intensity focused ultrasound. However, the optimal timing of magnetic resonance imaging has not been discussed. The thermal effect of high-intensity focused ultrasound is degraded by regional prostatic blood flow. Conversely, the mechanical effect of high-intensity focused ultrasound (cavitation) is not affected by blood flow, and can induce vessel damage. In this series, the longitudinal change of blood flow on contrast-enhanced magnetic resonance imaging was observed from postoperative day 1 to postoperative day 14 in 10 patients treated with high-intensity focused ultrasound. The median rates of increase in the non-enhanced volume of the whole gland, transition zone and peripheral zone from postoperative day 1 to postoperative day 14 were 36%, 39%, and 34%, respectively. In another pathological analysis of the prostate tissue of 17 patients immediately after high-intensity focused ultrasound without neoadjuvant hormonal therapy, we observed diffuse coagulative degeneration and partial non-coagulative prostate tissue around arteries with vascular endothelial cell detachment. These observations on contrast-enhanced magnetic resonance imaging support a time-dependent change of the blood flow in the prostate treated with high-intensity focused ultrasound. Additionally, our pathological findings support the longitudinal changes of these magnetic resonance imaging findings. Further large-scale studies will investigate the most appropriate timing of contrast-enhanced magnetic resonance imaging for evaluation of the effectiveness of high-intensity focused ultrasound for localized prostate cancer. © 2014 The Japanese Urological Association.

Bioprinting Cartilage Tissue from Mesenchymal Stem Cells and PEG Hydrogel.

Science.gov (United States)

Gao, Guifang; Hubbell, Karen; Schilling, Arndt F; Dai, Guohao; Cui, Xiaofeng

2017-01-01

Bioprinting based on thermal inkjet printing is one of the most attractive enabling technologies for tissue engineering and regeneration. During the printing process, cells, scaffolds , and growth factors are rapidly deposited to the desired two-dimensional (2D) and three-dimensional (3D) locations. Ideally, the bioprinted tissues are able to mimic the native anatomic structures in order to restore the biological functions. In this study, a bioprinting platform for 3D cartilage tissue engineering was developed using a commercially available thermal inkjet printer with simultaneous photopolymerization . The engineered cartilage demonstrated native zonal organization, ideal extracellular matrix (ECM ) composition, and proper mechanical properties. Compared to the conventional tissue fabrication approach, which requires extended UV exposure, the viability of the printed cells with simultaneous photopolymerization was significantly higher. Printed neocartilage demonstrated excellent glycosaminoglycan (GAG) and collagen type II production, which was consistent with gene expression profile. Therefore, this platform is ideal for anatomic tissue engineering with accurate cell distribution and arrangement.

"Why throw away something useful?": Attitudes and opinions of people treated for bipolar disorder and their relatives on organ and tissue donation.

Science.gov (United States)

Padoan, Carolina S; Garcia, Lucas F; Rodrigues, Aline A; Patusco, Lucas M; Atz, Mariana V; Kapczinski, Flavio; Goldim, José R; Magalhães, Pedro V S

2017-03-01

In regard to mental illness, brain donation is essential for the biological investigation of central pathology. Nevertheless, little is known about the thoughts of people with mental disorders on tissue donation for research. Here, our objective was to understand the attitudes and opinions of people treated for bipolar disorder and their relatives regarding donation in general, and particularly donation for research. This is a qualitative study that used in-depth interviews to determine the thoughts of participants regarding tissue donation for research. Theoretical sampling was used as a recruitment method. Grounded theory was used as a framework for content analyses of the interviews. A semi-structured interview guide was applied with the topics: donation in general; donation for research; mental health and body organs; opinion regarding donation; feelings aroused by the topic. Although all participants were aware of organ donation for transplant, they were surprised that tissue could be donated for research. Nevertheless, once they understood the concept they were usually in favor of the idea. Although participants demonstrated a general lack of knowledge on donation for research, they were willing to learn more and viewed it as a good thing, with altruistic reasons often cited as a motive for donation. We speculate that bridging this knowledge gap may be a fundamental step towards a more ethical postmortem tissue donation process.

Thermal lens measurements in the cornea.

Science.gov (United States)

Venkatesh, S; Guthrie, S; Cruickshank, F R; Bailey, R T; Foulds, W S; Lee, W R

1985-02-01

Q-switched pulses from a neodymium/YAG (yttrium-aluminium-garnet) laser were passed through corneal discs taken from the enucleated eyes of three baboons and four rabbits. The time course of heat dissipation following absorption of laser energy by the tissue was studied with the use of a second continuous wave laser beam acting as a probe. It was found that the absorption of each neodymium/YAG pulse created a transient divergent lens within the cornea as theoretical considerations predicted. The relaxation time that characterised the decay of this thermal lens for a 1/e laser beam diameter of 2.0 mm was found to be 2.3 +/- 0.1 s (mean +/- standard error for 12 separate groups of measurements). Our results show that Q-switched laser pulses passing through apparently unaffected transparent tissues can induce thermal lens effects which persist for several seconds. The optical transfer of each pulse in a stream will be identical only if enough time is left between pulses for the tissues to return to their initial state. Therefore, when such laser pulses sharply focused to perform high precision intraocular surgery are used, thermal lensing in the transparent ocular media must limit the rate at which pulses can be usefully delivered.

A Novel Composite PMMA-based Bone Cement with Reduced Potential for Thermal Necrosis.

Science.gov (United States)

Lv, Yang; Li, Ailing; Zhou, Fang; Pan, Xiaoyu; Liang, Fuxin; Qu, Xiaozhong; Qiu, Dong; Yang, Zhenzhong

2015-06-03

Percutaneous vertebroplasty (VP) and balloon kyphoplasty (BKP) are now widely used to treat patients who suffer painful vertebral compression fractures. In each of these treatments, a bone cement paste is injected into the fractured vertebral body/bodies, and the cement of choice is a poly(methyl methacrylate) (PMMA) bone cement. One drawback of this cement is the very high exothermic temperature, which, it has been suggested, causes thermal necrosis of surrounding tissue. In the present work, we prepared novel composite PMMA bone cement where microcapsules containing a phase change material (paraffin) (PCMc) were mixed with the powder of the cement. A PCM absorbs generated heat and, as such, its presence in the cement may lead to reduction in thermal necrosis. We determined a number of properties of the composite cement. Compared to the values for a control cement (a commercially available PMMA cement used in VP and BKP), each composite cement was found to have significantly lower maximum exothermic temperature, increased setting time, significantly lower compressive strength, significantly lower compressive modulus, comparable biocompatibility, and significantly smaller thermal necrosis zone. Composite cement containing 20% PCMc may be suitable for use in VP and BKP and thus deserves further evaluation.

Metabolic aspects of growth in HU-treated crown-gall tissue cultures. I. Nicotiana tabacum

Directory of Open Access Journals (Sweden)

Aldona Rennert

2015-01-01

Full Text Available An influence of hydroxyurea (HU on the growth, DNA and RNA contents and protein synthesis in the tobacco tumour tissue culture was studied in comparison with a homologous callus tissue. In conformity with expectations considerable decrease of DNA level in both tissues is a primary effect of HU activity. This results in the growth inhibition and in the secondary metabolic effects; these effects depend not only on the concentration of inhibitor but also on the age of tissue. In spite of some common features the character of these changes shows a distinct differentiation depending on the tissue type. TMs points to specific modifications of the biochemical regulation of growth in a tumour.

TU-B-210-01: MRg HIFU - Bone and Soft Tissue Tumor Ablation

International Nuclear Information System (INIS)

Ghanouni, P.

2015-01-01

MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advanced techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips

TU-B-210-01: MRg HIFU - Bone and Soft Tissue Tumor Ablation

Energy Technology Data Exchange (ETDEWEB)

Ghanouni, P. [Stanford University (United States)

2015-06-15

MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advanced techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips.

Development of stereotactically guided laser interstitial thermotherapy of breast cancer: in situ measurement and analysis of the temperature field in ex vivo and in vivo adipose tissue.

Science.gov (United States)

Milne, P J; Parel, J M; Manns, F; Denham, D B; Gonzalez-Cirre, X; Robinson, D S

2000-01-01

The size (0.5-1.0 cm) of early nonpalpable breast tumors currently detected by mammography and confirmed by stereotactic core biopsy is of the order of the penetration depth of near infrared photons in breast tissue. In principle, stereotactically biopsied tumors, therefore, could be safely and efficiently treated with laser thermotherapy. The aim of the current study is to confirm the controlled heating produced by clinically relevant power levels delivered with an interstitial laser fiber optic probe adapted for use with stereotactic mammography and biopsy procedures. Temperature increases and the resultant thermal field produced by the irradiation of ex vivo (porcine and human) and in vivo (porcine) tissue models appropriate to the treatment of human breast tissue by using cw Nd:YAG laser radiation delivered with a interstitial fiber optic probe with a quartz diffusing tip, were recorded with an array of fifteen 23-gauge needle thermocouple probes connected to a laboratory computer-based data acquisition system. By using a stepwise decreasing power cycle to avoid tissue charring, acceptably symmetric thermal fields of repeatable volumetric dimensions were obtained. Reproducible thermal gradients and predictable tissue necrosis without carbonization could be induced in a 3-cm-diameter region around the fiber probe during a single treatment lasting only 3 minutes. The time-dependences of the temperature rise of the thermocouples surrounding the LITT probe were quantitatively modeled with simple linear functions during the applied laser heating cycles. Analysis of our experimental results show that reproducible, symmetric and predictable volumetric temperature increases in time can be reliably produced by interstitial laser thermotherapy. Copyright 2000 Wiley-Liss, Inc.

Study of temperature increase and optic depth penetration in photo irradiated human tissues

International Nuclear Information System (INIS)

Stolik, Suren; Delgado, Jose A.; Perez, Arllene M.; Anasagasti, Lorenzo

2009-01-01

Optical radiation is widely applied in the treatment and diagnosis of different pathologies. If the power density of the incident light is sufficiently high to induce a significant temperature rise in the irradiated tissue, then it is also needed the knowledge of the thermal properties of the tissue for a complete understanding of the therapeutic effects. The thermal penetration depth of several human tissues has been measured applying the diffusion approximation of the radiative transfer equation for the distribution of optical radiation. The method, the experimental setup and the results are presented and discussed. (Author)

Thermally Induced Magnetite-Haematite Transformation

International Nuclear Information System (INIS)

Mazo-Zuluaga, J.; Barrero, C. A.; Diaz-Teran, J.; Jerez, A.

2003-01-01

The products of thermal treatments of pure and copper doped magnetites have been investigated using Moessbauer spectrometry, XRD and thermal analysis techniques. The samples were heated in air between RT and 800 o C at several heating rates. Samples treated at 520 o C during 12 and 24 hours consist only of well-crystallized haematite. On the other hand, magnetites treated at 350 o C consisted of mixtures of haematite, maghemite and magnetite, with relative amount of each phase depending on the presence of copper as well as on the heating time. Results show that the transformation of magnetite to haematite goes through the formation of maghemite, and that the presence of copper delays this transformation.

Thermally Induced Magnetite-Haematite Transformation

Energy Technology Data Exchange (ETDEWEB)

Mazo-Zuluaga, J.; Barrero, C. A. [Universidad de Antioquia, Grupo de Estado Solido, Instituto de Fisica (Colombia); Diaz-Teran, J.; Jerez, A. [Universidad Nacional de Educacion a Distancia UNED, Po Senda del Rey 9, Departamento de Quimica Inorganica y Quimica Tecnica (Spain)

2003-06-15

The products of thermal treatments of pure and copper doped magnetites have been investigated using Moessbauer spectrometry, XRD and thermal analysis techniques. The samples were heated in air between RT and 800{sup o}C at several heating rates. Samples treated at 520{sup o}C during 12 and 24 hours consist only of well-crystallized haematite. On the other hand, magnetites treated at 350{sup o}C consisted of mixtures of haematite, maghemite and magnetite, with relative amount of each phase depending on the presence of copper as well as on the heating time. Results show that the transformation of magnetite to haematite goes through the formation of maghemite, and that the presence of copper delays this transformation.

Treated of type 1 diabetes mellitus in non-obese diabetic mice by transplantation of allogeneic bone marrow and pancreatic tissue

International Nuclear Information System (INIS)

Yasumizu, R.; Sugiura, K.; Iwai, H.

1987-01-01

Non-obese diabetic (NOD) mice provide a model for type 1 diabetes mellitus. We previously showed that allogeneic bone marrow transplantation (ABMT) can prevent and treat insulitis and overt diabetes in NOD mice. However, ABMT alone could not be used to treat overt diabetes in NOD mice whose islets had been completely destroyed. To provide insulin-producing cells, pancreatic tissue from newborn mice was grafted under the renal capsules in combination with ABMT. The aims of concomitant ABMT are as follows. (i) It induces immunological tolerance to the donor-type major histocompatibility complex determinants and permits the host to accept subsequent pancreatic allografts from the bone marrow donor. (ii) ABMT replaces abnormal stem cells with normal stem cells. After transplantation of bone marrow plus newborn pancreas, NOD mice showed reduction of the glycosuria and a normal response in the glucose-tolerance test. Immunohistological study revealed the presence of clustered insulin-containing beta cells in the grafted pancreatic transplants. ABMT may become a viable treatment of established type 1 diabetes mellitus in humans

Intracavitary ultrasound phased arrays for thermal therapies

Science.gov (United States)

Hutchinson, Erin

Currently, the success of hyperthermia and thermal surgery treatments is limited by the technology used in the design and fabrication of clinical heating devices and the completeness of the thermometry systems used for guidance. For both hyperthermia and thermal surgery, electrically focused ultrasound generated by phased arrays provides a means of controlling localized energy deposition in body tissues. Intracavitary applicators can be used to bring the energy source close to a target volume, such as the prostate, thereby minimizing normal tissue damage. The work performed in this study was aimed at improving noninvasive prostate thermal therapies and utilized three research approaches: (1) Acoustic, thermal and optimization simulations, (2) Design and fabrication of multiple phased arrays, (3) Ex vivo and in vivo experimental testing of the heating capabilities of the phased arrays. As part of this study, a novel aperiodic phased array design was developed which resulted in a 30- 45% reduction in grating lobe levels when compared to conventional phased arrays. Measured acoustic fields generated by the constructed aperiodic arrays agreed closely with the fields predicted by the theoretical simulations and covered anatomically appropriate ranges. The power capabilities of these arrays were demonstrated to be sufficient for the purposes of hyperthermia and thermal surgery. The advantage of using phased arrays in place of fixed focus transducers was shown by demonstrating the ability of electronic scanning to increase the size of the necrosed tissue volume while providing a more uniform thermal dose, which can ultimately reduce patient treatment times. A theoretical study on the feasibility of MRI (magnetic resonance imaging) thermometry for noninvasive temperature feedback control was investigated as a means to improve transient and steady state temperature distributions achieved in hyperthermia treatments. MRI guided ex vivo and in vivo experiments demonstrated

A flexible infrared sensor for tissue oximetry

DEFF Research Database (Denmark)

Petersen, Søren Dahl; Thyssen, Anders; Engholm, Mathias

2013-01-01

We present a flexible infrared sensor for use in tissue oximetry with the aim of treating prematurely born infants. The sensor will detect the oxygen saturation in brain tissue through near infrared spectroscopy. The sensor itself consists of several individual silicon photo detectors fully...

Phosphorylation of ribosomal proteins induced by auxins in maize embryonic tissues

International Nuclear Information System (INIS)

Perez, L.; Aguilar, R.; Mendez, A.P.; de Jimenez, E.S.

1990-01-01

The effect of auxin on ribosomal protein phosphorylation of germinating maize (Zea mays) tissues was investigated. Two-dimensional gel electrophoresis and autoradiography of [ 32 P] ribosomal protein patterns for natural and synthetic auxin-treated tissues were performed. Both the rate of 32 P incorporation and the electrophoretic patterns were dependent on 32 P pulse length, suggesting that active protein phosphorylation-dephosphorylation occurred in small and large subunit proteins, in control as well as in auxin-treated tissues. The effect of ribosomal protein phosphorylation on in vitro translation was tested. Measurements of poly(U) translation rates as a function of ribosome concentration provided apparent K m values significantly different for auxin-treated and nontreated tissues. These findings suggest that auxin might exert some kind of translational control by regulating the phosphorylated status of ribosomal proteins

Normalization of periodontal tissues in osteopetrotic mib mutant rats, treated with CSF-1

Science.gov (United States)

Wojtowicz, A.; Yamauchi, M.; Sotowski, R.; Ostrowski, K.

1998-01-01

The osteopetrotic mib mutation in rats causes defects in the skeletal bone tissue in young animals. These defects, i.e. slow bone remodelling, changes in both crystallinity and mineral content, are transient and undergo normalization, even without any treatment in 6-wk-old animals. Treatment with CSF-1 (colony stimulating factor-1) accelerates the normalization process in skeletal bones. The periodontal tissues around the apices of incisors show abnormalities caused by the slow remodelling process of the mandible bone tissue, the deficiency of osteoclasts and their abnormal morphology, as well as the disorganization of periodontal ligament fibres. In contrast to the skeletal tissues, these abnormalities would not undergo spontaneous normalization. Under treatment with colony stimulating factor 1 (CSF-1), the primitive bone trabeculae of mandible are resorbed and the normalization of the number of osteoclasts and their cytology occurs. The organization of the periodontal ligament fibres is partially restored, resembling the histological structure of the normal one.

Effect of heat treatment temperature on binder thermal conductivities

International Nuclear Information System (INIS)

Wagner, P.

1975-12-01

The effect of heat treatment on the thermal conductivities of a pitch and a polyfurfuryl alcohol binder residue was investigated. Graphites specially prepared with these two binders were used for the experiments. Measured thermal conductivities were treated in terms of a two-component system, and the binder thermal conductivities were calculated. Both binder residues showed increased thermal conductivity with increased heat treatment temperature

Nd : YAG surgical laser effects in canine prostate tissue: temperature and damage distribution

NARCIS (Netherlands)

van Nimwegen, S. A.; L'Eplattenier, H. F.; Rem, A. I.; van der Lugt, J. J.; Kirpensteijn, J.

2009-01-01

An in vitro model was used to predict short-term, laser-induced, thermal damage in canine prostate tissue. Canine prostate tissue samples were equipped with thermocouple probes to measure tissue temperature at 3, 6, 9 and 12 mm depths. The tissue surface was irradiated with a Nd:YAG laser in contact

Investigation of non-thermal plasma effects on lung cancer cells within 3D collagen matrices

Science.gov (United States)

Karki, Surya B.; Thapa Gupta, Tripti; Yildirim-Ayan, Eda; Eisenmann, Kathryn M.; Ayan, Halim

2017-08-01

Recent breakthroughs in plasma medicine have identified a potential application for the non-thermal plasma in cancer therapy. Most studies on the effects of non-thermal plasma on cancer cells have used traditional two-dimensional (2D) monolayer cell culture. However, very few studies are conducted employing non-thermal plasma in animal models. Two dimensional models do not fully mimic the three-dimensional (3D) tumor microenvironment and animal models are expensive and time-consuming. Therefore, we used 3D collagen matrices that closely resemble the native geometry of cancer tissues and provide more physiologically relevant results than 2D models, while providing a more cost effective and efficient precursor to animal studies. We previously demonstrated a role for non-thermal plasma application in promoting apoptotic cell death and reducing the viability of A549 lung adenocarcinoma epithelial cells cultured upon 2D matrices. In this study, we wished to determine the efficacy of non-thermal plasma application in driving apoptotic cell death of A549 lung cancer cells encapsulated within a 3D collagen matrix. The percentage of apoptosis increased as treatment time increased and was time dependent. In addition, the anti-viability effect of plasma was demonstrated. Twenty-four hours post-plasma treatment, 38% and 99% of cell death occurred with shortest (15 s) and longest treatment time (120 s) respectively at the plasma-treated region. We found that plasma has a greater effect on the viability of A549 lung cancer cells on the superficial surface of 3D matrices and has diminishing effects as it penetrates the 3D matrix. We also identified the nitrogen and oxygen species generated by plasma and characterized their penetration in vertical and lateral directions within the 3D matrix from the center of the plasma-treated region. Therefore, the utility of non-thermal dielectric barrier discharge plasma in driving apoptosis and reducing the viability of lung cancer cells

Investigation of non-thermal plasma effects on lung cancer cells within 3D collagen matrices

International Nuclear Information System (INIS)

Karki, Surya B; Gupta, Tripti Thapa; Yildirim-Ayan, Eda; Ayan, Halim; Eisenmann, Kathryn M

2017-01-01

Recent breakthroughs in plasma medicine have identified a potential application for the non-thermal plasma in cancer therapy. Most studies on the effects of non-thermal plasma on cancer cells have used traditional two-dimensional (2D) monolayer cell culture. However, very few studies are conducted employing non-thermal plasma in animal models. Two dimensional models do not fully mimic the three-dimensional (3D) tumor microenvironment and animal models are expensive and time-consuming. Therefore, we used 3D collagen matrices that closely resemble the native geometry of cancer tissues and provide more physiologically relevant results than 2D models, while providing a more cost effective and efficient precursor to animal studies. We previously demonstrated a role for non-thermal plasma application in promoting apoptotic cell death and reducing the viability of A549 lung adenocarcinoma epithelial cells cultured upon 2D matrices. In this study, we wished to determine the efficacy of non-thermal plasma application in driving apoptotic cell death of A549 lung cancer cells encapsulated within a 3D collagen matrix. The percentage of apoptosis increased as treatment time increased and was time dependent. In addition, the anti-viability effect of plasma was demonstrated. Twenty-four hours post-plasma treatment, 38% and 99% of cell death occurred with shortest (15 s) and longest treatment time (120 s) respectively at the plasma-treated region. We found that plasma has a greater effect on the viability of A549 lung cancer cells on the superficial surface of 3D matrices and has diminishing effects as it penetrates the 3D matrix. We also identified the nitrogen and oxygen species generated by plasma and characterized their penetration in vertical and lateral directions within the 3D matrix from the center of the plasma-treated region. Therefore, the utility of non-thermal dielectric barrier discharge plasma in driving apoptosis and reducing the viability of lung cancer cells

Ocular adnexal mucosa-associated lymphoid tissue lymphoma treated with radiotherapy

International Nuclear Information System (INIS)

Ejima, Yasuo; Sasaki, Ryohei; Okamoto, Yoshiaki; Maruta, Tsutomu; Azumi, Atsushi; Hayashi, Yoshitake; Demizu, Yusuke; Ota, Yosuke; Soejima, Toshinori; Sugimura, Kazuro

2006-01-01

Forty-two patients with stage IE ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma were retrospectively analyzed. Five-year local control and progression-free survival rates were 100 and 77%, respectively. The most common relapsed site was the contralateral orbit. Thirty Gy of local irradiation seemed to be quite effective and safe

Improving thermal stability and efficacy of BCNU in treating glioma cells using PAA-functionalized graphene oxide

Directory of Open Access Journals (Sweden)

Lu YJ

2012-03-01

Full Text Available Yu-Jen Lu1,2,#, Hung-Wei Yang1,#, Sheng-Che Hung3, Chiung-Yin Huang2, Shin-Ming Li4, Chen-Chi M Ma4, Pin-Yuan Chen2, Hong-Chieh Tsai2, Kuo-Chen Wei2, Jyh-Ping Chen1 1Department of Chemical and Materials Engineering, Chang Gung University, Kwei-San, Taoyuan, Taiwan; 2Department of Neurosurgery, Chang Gung Memorial Hospital, Kwei-San, Taoyuan, Taiwan; 3Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan; 4Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan#These authors contributed equally to this workBackground: 1,3-bis(2-chloroethyl-1-nitrosourea (BCNU, a commercial chemotherapeutic drug for treating malignant brain tumors, has poor thermal stability and a short half-life. Immobilization of BCNU on a nanocarrier might increase the thermal stability of BCNU and extend its half-life.Methods: Nanosized graphene oxide (GO could be modified by polyacrylic acid (PAA to improve the aqueous solubility and increase the cell penetration efficacy of the nanocarrier. PAA–GO intended as a drug carrier for BCNU was prepared and characterized in this study. The size and thickness of PAA–GO was investigated by transmission electron microscopy and atomic force microscopy, and the presence of PAA functional groups was confirmed by electron spectroscopy for chemical analysis and thermogravimetric analysis. BCNU was conjugated to PAA–GO by covalent binding for specific killing of cancer cells, which could also enhance the thermal stability of the drug.Results: Single layer PAA–GO (about 1.9 nm with a lateral width as small as 36 nm was successfully prepared. The optimum drug immobilization condition was by reacting 0.5 mg PAA–GO with 0.4 mg BCNU, and the drug-loading capacity and residual drug activity were 198 µg BCNU/mg PAA–GO and 70%, respectively. This nanocarrier significantly prolonged the half-life of bound BCNU from 19 to 43 hours compared with free drug and showed efficient intracellular

Imposed Thermal Fatigue and Post-Thermal-Cycle Wear Resistance of Biomimetic Gray Cast Iron by Laser Treatment

Science.gov (United States)

Sui, Qi; Zhou, Hong; Zhang, Deping; Chen, Zhikai; Zhang, Peng

2017-08-01

The present study aims to create coupling biomimetic units on gray cast iron substrate by laser surface treatment (LST). LSTs for single-step (LST1) and two-step (LST2) processes, were carried out on gray cast iron in different media (air and water). Their effects on microstructure, thermal fatigue, and post-thermal-cycle wear (PTW) resistance on the specimens were studied. The tests were carried out to examine the influence of crack-resistance behavior as well as the biomimetic surface on its post-thermal-cycle wear behavior and different units, with different laser treatments for comparison. Results showed that LST2 enhanced the PTW behaviors of gray cast iron, which then led to an increase in its crack resistance. Among the treated cast irons, the one treated by LST2 in air showed the lowest residual stress, due to the positive effect of the lower steepness of the thermal gradient. Moreover, the same specimen showed the best PTW performance, due to its superior crack resistance and higher hardness as a result of it.

Temperature dependent capacity contribution of thermally treated anode current collectors in lithium ion batteries

International Nuclear Information System (INIS)

Kim, Tae Kwon; Li Xifei; Wang Chunlei

2013-01-01

Highlights: ► We studied the influence of the thermal treatment of current collectors on the energy capacity. ► Different current collectors show different thermal treatment effect on performance. ► The non-negligible capacity contribution is closely related to the treatment temperatures. ► Our results could be beneficial to designing battery architectures. - Abstract: Metal current collectors, offering a good connection between the active materials and the external circuit, is an important component in a rechargeable lithium ion battery. Some necessary thermal treatment in the battery fabrication and assembly procedure results in current collectors with some non-negligible reversible energy capacities; however, these energy capacities were negligible in the previous references. In this research, for the first time, we investigated the influence of the thermal treatment of current collectors (such as copper foil and stainless steel disk) on energy capacities. Our results indicate that different current collector materials have different thermal treatment effects on their electrochemical performance. The non-negligible capacity contribution is closely related to the treatment temperature.

Optoacoustic monitoring of cutting efficiency and thermal damage during laser ablation.

Science.gov (United States)

Bay, Erwin; Douplik, Alexandre; Razansky, Daniel

2014-05-01

Successful laser surgery is characterized by a precise cut and effective hemostasis with minimal collateral thermal damage to the adjacent tissues. Consequently, the surgeon needs to control several parameters, such as power, pulse repetition rate, and velocity of movements. In this study we propose utilizing optoacoustics for providing the necessary real-time feedback of cutting efficiency and collateral thermal damage. Laser ablation was performed on a bovine meat slab using a Q-switched Nd-YAG laser (532 nm, 4 kHz, 18 W). Due to the short pulse duration of 7.6 ns, the same laser has also been used for generation of optoacoustic signals. Both the shockwaves, generated due to tissue removal, as well as the normal optoacoustic responses from the surrounding tissue were detected using a single broadband piezoelectric transducer. It has been observed that the rapid reduction in the shockwave amplitude occurs as more material is being removed, indicating decrease in cutting efficiency, whereas gradual decrease in the optoacoustic signal likely corresponds to coagulation around the ablation crater. Further heating of the surrounding tissue leads to carbonization accompanied by a significant shift in the optoacoustic spectra. Our results hold promise for real-time monitoring of cutting efficiency and collateral thermal damage during laser surgery. In practice, this could eventually facilitate development of automatic cut-off mechanisms that will guarantee an optimal tradeoff between cutting and heating while avoiding severe thermal damage to the surrounding tissues.

Histochemical characterization of human osteochondral tissue: comparison between healthy cartilage, arthrotic tissues, and cartilage defect treated with MACI technique

Directory of Open Access Journals (Sweden)

F. Tessarolo

2011-01-01

Full Text Available Matrix-induced sutologous chondrocytes implantation (MACI is a promising technique for the treatment of articular cartilage lesions, but long time outcome have to be established. We developed and optimized specific techniques of histochemical staining to characterize healthy and pathologic osteochondral tissue. Seven different staining protocols were applied to assess tissue architecture, cells morphology, proteoglycan content, and collagen fibers distribution. Potentialities of histochemical staining and histomorphology of biopsies from second look arthroscopy will be presented.

Bioengineering Strategies to Treat Female Infertility.

Science.gov (United States)

Kuo, Che-Ying; Baker, Hannah; Fries, Melissa H; Yoo, James J; Kim, Peter C W; Fisher, John P

2017-06-01

Bioengineering strategies have demonstrated enormous potential to treat female infertility as a result of chemotherapy, uterine injuries, fallopian tube occlusion, massive intrauterine adhesions, congenital uterine malformations, and hysterectomy. These strategies can be classified into two broad categories as follows: (i) Transplantation of fresh or cryopreserved organs into the host and (ii) tissue engineering approaches that utilize a combination of cells, growth factors, and biomaterials that leverages the body's inherent ability to regenerate/repair reproductive organs. While whole organ transplant has demonstrated success, the source of the organ and the immunogenic effects of allografts remain challenging. Even though tissue engineering strategies can avoid these issues, their feasibilities of creating whole organ constructs are yet to be demonstrated. In this article we summarize the recent advancements in the applications of bioengineering to treat female infertility.

Thermal wave propagation in blood perfused tissues under hyperthermia treatment for unique oscillatory heat flux at skin surface and appropriate initial condition

Science.gov (United States)

Dutta, Jaideep; Kundu, Balaram

2018-05-01

This paper aims to develop an analytical study of heat propagation in biological tissues for constant and variable heat flux at the skin surface correlated with Hyperthermia treatment. In the present research work we have attempted to impose two unique kind of oscillating boundary condition relevant to practical aspect of the biomedical engineering while the initial condition is constructed as spatially dependent according to a real life situation. We have implemented Laplace's Transform method (LTM) and Green Function (GFs) method to solve single phase lag (SPL) thermal wave model of bioheat equation (TWMBHE). This research work strongly focuses upon the non-invasive therapy by employing oscillating heat flux. The heat flux at the skin surface is considered as constant, sinusoidal, and cosine forms. A comparative study of the impact of different kinds of heat flux on the temperature field in living tissue explored that sinusoidal heat flux will be more effective if the time of therapeutic heating is high. Cosine heating is also applicable in Hyperthermia treatment due to its precision in thermal waveform. The result also emphasizes that accurate observation must be required for the selection of phase angle and frequency of oscillating heat flux. By possible comparison with the published experimental research work and published mathematical study we have experienced a difference in temperature distribution as 5.33% and 4.73%, respectively. A parametric analysis has been devoted to suggest an appropriate procedure of the selection of important design variables in viewpoint of an effective heating in hyperthermia treatment.

CO2 laser milling of hard tissue

Science.gov (United States)

Werner, Martin; Ivanenko, Mikhail; Harbecke, Daniela; Klasing, Manfred; Steigerwald, Hendrik; Hering, Peter

2007-02-01

Drilling of bone and tooth tissue belongs to recurrent medical procedures (screw- and pin-bores, bores for implant inserting, trepanation etc.). Small round bores can be in general quickly produced with mechanical drills. Problems arise however by angled drilling, by the necessity to fulfill the drilling without damaging of sensitive soft tissue beneath the bone, or by the attempt to mill precisely noncircular small cavities. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The "milling" is done with a CO2 laser (10.6 μm) with pulse duration of 50 - 100 μs, combined with a PC-controlled galvanic beam scanner and with a fine water-spray, which helps to avoid thermal side-effects. The damaging of underlying soft tissue can be prevented through control of the optical or acoustical ablation signal. The ablation of hard tissue is accompanied with a strong glowing, which is absent during the laser beam action on soft tissue. The acoustic signals from the diverse tissue types exhibit distinct differences in the spectral composition. Also computer image analysis could be a useful tool to control the operation. Laser "milling" of noncircular cavities with 1 - 4 mm width and about 10 mm depth is particularly interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser "milling" of the cavities without thermal damage and with minimal tapering. It included exploration of different filling patterns (concentric rings, crosshatch, parallel lines and their combinations), definition of maximal pulse duration, repetition rate and laser power, optimal position of the spray. The optimized results give evidences for the applicability of the CO2 laser for biologically tolerable "milling" of deep cavities in the hard tissue.

Cryotherapy usage to treat plantar warts

International Nuclear Information System (INIS)

Miranda Diaz, BelkisTamara

2010-01-01

Treating dermatosis with liquid nitrogen as cryogen (substance generating cold) allows cellular destruction in more than 5 mm depth, making it indispensable to use it treating cutaneous cancers; besides that, it is cheap, easy to conserve and manage, and it is not considered flammable or toxic. Its applying retains the growth factor inside the injury, the collagen is not damaged as it is in burning by hot, there is not almost injury contraction, the perineurium is not altered, and when the tissue necrosis takes place, it retains tissue necrosis factor, helping to increase the necrosis of tissues. Taking into account the high incidence of dermatosis that can be treated with cryogen, in our consultation; we decided to generalize this treatment at the Provincial Interior Ministry Clinic. Plantar warts represent a big percent, limiting our patients in developing their working activities. This cutaneous viral disease is favored by the patients' systemic immunodepressions, hyperhidrosis and podalic disturbances. We selected the patients assisting to our extern al consultation with plantar wart clinical diagnosis in the period from September 2006 to September 2007. They signed an act of informed consent where the possible side effects are explained. Liquid nitrogen was applied with cotton applicators once a week after mechanical reduction. We made a clinical evolving evaluation fortnightly during the treatment, according to the elements and clinical characteristics referred by the patient, and proved by the physical examination carried out by the main investigator, because of the likelihood of short and long time side effects. This investigation demonstrated that cryotherapy is efficacious in treating plantar warts, since all the patients were healed in a short time period, most of them without side effects

Electrospun polyurethane membranes for Tissue Engineering applications

Energy Technology Data Exchange (ETDEWEB)

Gabriel, Laís P., E-mail: lagabriel@gmail.com [National Institute of Biofabrication, Campinas (Brazil); Department of Chemical Engineering, University of Campinas, Campinas (Brazil); Rodrigues, Ana Amélia [National Institute of Biofabrication, Campinas (Brazil); Department of Medical Sciences, University of Campinas, Campinas (Brazil); Macedo, Milton; Jardini, André L.; Maciel Filho, Rubens [National Institute of Biofabrication, Campinas (Brazil); Department of Chemical Engineering, University of Campinas, Campinas (Brazil)

2017-03-01

Tissue Engineering proposes, among other things, tissue regeneration using scaffolds integrated with biological molecules, growth factors or cells for such regeneration. In this research, polyurethane membranes were prepared using the electrospinning technique in order to obtain membranes to be applied in Tissue Engineering, such as epithelial, drug delivery or cardiac applications. The influence of fibers on the structure and morphology of the membranes was studied using scanning electron microscopy (SEM), the structure was evaluated by Fourier transform infrared spectroscopy (FT-IR), and the thermal stability was analyzed by thermogravimetry analysis (TGA). In vitro cells attachment and proliferation was investigated by SEM, and in vitro cell viability was studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays and Live/Dead® assays. It was found that the membranes present an homogeneous morphology, high porosity, high surface area/volume ratio, it was also observed a random fiber network. The thermal analysis showed that the membrane degradation started at 254 °C. In vitro evaluation of fibroblasts cells showed that fibroblasts spread over the membrane surface after 24, 48 and 72 h of culture. This study supports the investigation of electrospun polyurethane membranes as biocompatible scaffolds for Tissue Engineering applications and provides some guidelines for improved biomaterials with desired properties.

Controlled destruction and temperature distributions in biological tissues subjected to monoactive electrocoagulation.

Science.gov (United States)

Erez, A; Shitzer, A

1980-02-01

An analysis of the temperature fields developed in a biological tissue undergoing a monoactive electrical coagulating process is presented, including thermal recovery following prolonged heating. The analysis is performed for the passage of alternating current and assumes a homogeneous and isotropic tissue model which is uniformly perfused by blood at arterial temperature. Solution for the one-dimensional spherical geometry is obtained by a Laplace transform and numerical integrations. Results obtained indicate the major role which blood perfusion plays in determining the effects of the coagulating process; tissue temperatures and depth of destruction are drastically reduced as blood perfusion increases. Metabolic heat generation rate is found to have negligible effects on tissue temperatures whereas electrode thermal inertia affects temperature levels appreciably. However, electrodes employed in practice would have a low thermal inertia which might be regarded as zero for all practical purposes. It is also found that the depth of tissue destruction is almost directly proportional to the electrical power and duration of application. To avoid excessively high temperatures and charring, it would be advantageous to reduce power and increase the time of application. Results of this study should be regarded as a first approximation to the rather complex phenomena associated with electrocoagulation. They may, nevertheless, serve as preliminary guidelines to practicing surgeons applying this technique.

Overview of thermal conductivity models of anisotropic thermal insulation materials

Science.gov (United States)

Skurikhin, A. V.; Kostanovsky, A. V.

2017-11-01

Currently, the most of existing materials and substances under elaboration are anisotropic. It makes certain difficulties in the study of heat transfer process. Thermal conductivity of the materials can be characterized by tensor of the second order. Also, the parallelism between the temperature gradient vector and the density of heat flow vector is violated in anisotropic thermal insulation materials (TIM). One of the most famous TIM is a family of integrated thermal insulation refractory material («ITIRM»). The main component ensuring its properties is the «inflated» vermiculite. Natural mineral vermiculite is ground into powder state, fired by gas burner for dehydration, and its precipitate is then compressed. The key feature of thus treated batch of vermiculite is a package structure. The properties of the material lead to a slow heating of manufactured products due to low absorption and high radiation reflection. The maximum of reflection function is referred to infrared spectral region. A review of current models of heat propagation in anisotropic thermal insulation materials is carried out, as well as analysis of their thermal and optical properties. A theoretical model, which allows to determine the heat conductivity «ITIRM», can be useful in the study of thermal characteristics such as specific heat capacity, temperature conductivity, and others. Materials as «ITIRM» can be used in the metallurgy industry, thermal energy and nuclear power-engineering.

Microstructure and Mechanical Property of Glutaraldehyde-Treated Porcine Pulmonary Ligament.

Science.gov (United States)

Chen, Huan; Zhao, Xuefeng; Berwick, Zachary C; Krieger, Joshua F; Chambers, Sean; Kassab, Ghassan S

2016-06-01

There is a significant need for fixed biological tissues with desired structural and material constituents for tissue engineering applications. Here, we introduce the lung ligament as a fixed biological material that may have clinical utility for tissue engineering. To characterize the lung tissue for potential clinical applications, we studied glutaraldehyde-treated porcine pulmonary ligament (n = 11) with multiphoton microscopy (MPM) and conducted biaxial planar experiments to characterize the mechanical property of the tissue. The MPM imaging revealed that there are generally two families of collagen fibers distributed in two distinct layers: The first family largely aligns along the longitudinal direction with a mean angle of θ = 10.7 ± 9.3 deg, while the second one exhibits a random distribution with a mean θ = 36.6 ± 27.4. Elastin fibers appear in some intermediate sublayers with a random orientation distribution with a mean θ = 39.6 ± 23 deg. Based on the microstructural observation, a microstructure-based constitutive law was proposed to model the elastic property of the tissue. The material parameters were identified by fitting the model to the biaxial stress-strain data of specimens, and good fitting quality was achieved. The parameter e0 (which denotes the strain beyond which the collagen can withstand tension) of glutaraldehyde-treated tissues demonstrated low variability implying a relatively consistent collagen undulation in different samples, while the stiffness parameters for elastin and collagen fibers showed relatively greater variability. The fixed tissues presented a smaller e0 than that of fresh specimen, confirming that glutaraldehyde crosslinking increases the mechanical strength of collagen-based biomaterials. The present study sheds light on the biomechanics of glutaraldehyde-treated porcine pulmonary ligament that may be a candidate for tissue engineering.

Visualization of thermally activated nanocarriers using in situ atomic force microscopy

DEFF Research Database (Denmark)

Dong, M. D.; Howard, K. A.; Oupicky, D.

2007-01-01

Thermo-responsive nanocarriers aim to improve the delivery of drugs into target tissue by a process of size-mediated deposition activated by thermal stimuli. The direct imaging of thermally-induced changes in nanocarrier morphology was demonstrated using in situ liquid AFM over a nano-scale and t......-scale and temperature range relevant for clinical approaches. In situ AFM proved to be a unique method for investigating the dynamic conformational changes of individual nanoparticles, promoting its application in the future development of stimuli-responsive nanocarriers.......Thermo-responsive nanocarriers aim to improve the delivery of drugs into target tissue by a process of size-mediated deposition activated by thermal stimuli. The direct imaging of thermally-induced changes in nanocarrier morphology was demonstrated using in situ liquid AFM over a nano...

A principle for the noninvasive measurement of steady-state heat transfer parameters in living tissues

Directory of Open Access Journals (Sweden)

S. Yu. Makarov

2014-01-01

Full Text Available Measuring the parameters of biological tissues (include in vivo is of great importance for medical diagnostics. For example, the value of the blood perfusion parameter is associated with the state of the blood microcirculation system and its functioning affects the state of the tissues of almost all organs. This work describes a previously proposed principle [1] in generalized terms. The principle is intended for noninvasive measuring the parameters of stationary heat transfer in biological tissues. The results of some experiments (natural and numeric are also presented in the research.For noninvasive measurement of thermophysical parameters a number of techniques have been developed using non-stationary thermal process in biological tissue [2][3]. But these techniques require the collecting a lot of data to represent the time-dependent thermal signal. In addition, subsequent processing with specialized algorithms is required for optimal selecting the parameters. The goal of this research is to develop an alternative approach using stationary thermal process for non-invasive measuring the parameters of stationary heat transfer in living tissues.A general principle can be formulated for the measurement methods based on this approach. Namely, the variations (changes of two physical values are measured in the experiment at the transition from one thermal stationary state to another. One of these two physical values unambiguously determines the stationary thermal field into the biological tissue under specified experimental conditions while the other one is unambiguously determined through the thermal field. Then, the parameters can be found from the numerical (or analytical functional dependencies linking the measured variations because the dependencies contain unknown parameters.The dependencies are expressed in terms of the formula:dqi = fi({pj},Ui dUi,Here dqi is a variation of a physical value q which is unambiguously determined from the

Laser-induced photo-thermal strain imaging

Science.gov (United States)

Choi, Changhoon; Ahn, Joongho; Jeon, Seungwan; Kim, Chulhong

2018-02-01

Vulnerable plaque is the one of the leading causes of cardiovascular disease occurrence. However, conventional intravascular imaging techniques suffer from difficulty in finding vulnerable plaque due to limitation such as lack of physiological information, imaging depth, and depth sensitivity. Therefore, new techniques are needed to help determine the vulnerability of plaque, Thermal strain imaging (TSI) is an imaging technique based on ultrasound (US) wave propagation speed that varies with temperature of medium. During temperature increase, strain occurs in the medium and its variation tendency is depending on the type of tissue, which makes it possible to use for tissue differentiation. Here, we demonstrate laser-induced photo-thermal strain imaging (pTSI) to differentiate tissue using an intravascular ultrasound (IVUS) catheter and a 1210-nm continuous-wave laser for heating lipids intensively. During heating, consecutive US images were obtained from a custom-made phantom made of porcine fat and gelatin. A cross correlation-based speckle-tracking algorithm was then applied to calculate the strain of US images. In the strain images, the positive strain produced in lipids (porcine fat) was clearly differentiated from water-bearing tissue (gelatin). This result shows that laser-induced pTSI could be a new method to distinguish lipids in the plaque and can help to differentiate vulnerability of plaque.

Improved numerical modelling of heat transfer in human tissue exposed to RF

International Nuclear Information System (INIS)

Prishvin, Mikheil; Zaridze, Revaz; Bit-Babik, Georgi; Faraone, Antonio

2010-01-01

Full text: A novel numerical model to simulate thermal response of human body tissues exposed to RF energy is presented in this article. It is based on a new algorithm for the construction of a realistic blood vessel network, a new model of blood flow velocity distribution and an approach to solve the bio-heat equation in human tissue with variable and initially unknown blood temperature distribution. The algorithm generates a discrete 3D representation of both arterial and venous vascular networks and a continuous blood velocity vector field for arbitrary enclosed geome tries required to represent the complex anatomy of human body and blood flow. The results obtained in this article by applying the developed method to realistic exposure con ditions demonstrates relative difference in thermal response of the exposed tissue compared to results obtained by conventional bio-heat equation with constant blood perfusion and temperature. The developed technique may provide more accurate and realistic modelling in thermal dosimetry studies of human body RF exposure.

Supercritical carbon dioxide extracted extracellular matrix material from adipose tissue

Energy Technology Data Exchange (ETDEWEB)

Wang, Jun Kit; Luo, Baiwen; Guneta, Vipra [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Li, Liang; Foo, Selin Ee Min [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Dai, Yun; Tan, Timothy Thatt Yang [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Tan, Nguan Soon [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, 61 Biopolis Drive, Proteos, Singapore 138673 (Singapore); KK Research Centre, KK Women' s and Children' s Hospital, 100 Bukit Timah Road, Singapore 229899 (Singapore); Choong, Cleo, E-mail: cleochoong@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); KK Research Centre, KK Women' s and Children' s Hospital, 100 Bukit Timah Road, Singapore 229899 (Singapore); Wong, Marcus Thien Chong [Plastic, Reconstructive & Aesthetic Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore)

2017-06-01

Adipose tissue is a rich source of extracellular matrix (ECM) material that can be isolated by delipidating and decellularizing the tissue. However, the current delipidation and decellularization methods either involve tedious and lengthy processes or require toxic chemicals, which may result in the elimination of vital proteins and growth factors found in the ECM. Hence, an alternative delipidation and decellularization method for adipose tissue was developed using supercritical carbon dioxide (SC-CO{sub 2}) that eliminates the need of any harsh chemicals and also reduces the amount of processing time required. The resultant SC-CO{sub 2}-treated ECM material showed an absence of nuclear content but the preservation of key proteins such as collagen Type I, collagen Type III, collagen Type IV, elastin, fibronectin and laminin. In addition, other biological factors such as glycosaminoglycans (GAGs) and growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were also retained. Subsequently, the resulting SC-CO{sub 2}-treated ECM material was used as a bioactive coating on tissue culture plastic (TCP). Four different cell types including adipose tissue-derived mesenchymal stem cells (ASCs), human umbilical vein endothelial cells (HUVECs), immortalized human keratinocyte (HaCaT) cells and human monocytic leukemia cells (THP-1) were used in this study to show that the SC-CO{sub 2}-treated ECM coating can be potentially used for various biomedical applications. The SC-CO{sub 2}-treated ECM material showed improved cell-material interactions for all cell types tested. In addition, in vitro scratch wound assay using HaCaT cells showed that the presence of SC-CO{sub 2}-treated ECM material enhanced keratinocyte migration whilst the in vitro cellular studies using THP-1-derived macrophages showed that the SC-CO{sub 2}-treated ECM material did not evoke pro-inflammatory responses from the THP-1-derived macrophages. Overall

Supercritical carbon dioxide extracted extracellular matrix material from adipose tissue.

Science.gov (United States)

Wang, Jun Kit; Luo, Baiwen; Guneta, Vipra; Li, Liang; Foo, Selin Ee Min; Dai, Yun; Tan, Timothy Thatt Yang; Tan, Nguan Soon; Choong, Cleo; Wong, Marcus Thien Chong

2017-06-01

Adipose tissue is a rich source of extracellular matrix (ECM) material that can be isolated by delipidating and decellularizing the tissue. However, the current delipidation and decellularization methods either involve tedious and lengthy processes or require toxic chemicals, which may result in the elimination of vital proteins and growth factors found in the ECM. Hence, an alternative delipidation and decellularization method for adipose tissue was developed using supercritical carbon dioxide (SC-CO 2 ) that eliminates the need of any harsh chemicals and also reduces the amount of processing time required. The resultant SC-CO 2 -treated ECM material showed an absence of nuclear content but the preservation of key proteins such as collagen Type I, collagen Type III, collagen Type IV, elastin, fibronectin and laminin. In addition, other biological factors such as glycosaminoglycans (GAGs) and growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were also retained. Subsequently, the resulting SC-CO 2 -treated ECM material was used as a bioactive coating on tissue culture plastic (TCP). Four different cell types including adipose tissue-derived mesenchymal stem cells (ASCs), human umbilical vein endothelial cells (HUVECs), immortalized human keratinocyte (HaCaT) cells and human monocytic leukemia cells (THP-1) were used in this study to show that the SC-CO 2 -treated ECM coating can be potentially used for various biomedical applications. The SC-CO 2 -treated ECM material showed improved cell-material interactions for all cell types tested. In addition, in vitro scratch wound assay using HaCaT cells showed that the presence of SC-CO 2 -treated ECM material enhanced keratinocyte migration whilst the in vitro cellular studies using THP-1-derived macrophages showed that the SC-CO 2 -treated ECM material did not evoke pro-inflammatory responses from the THP-1-derived macrophages. Overall, this study shows the efficacy

Supercritical carbon dioxide extracted extracellular matrix material from adipose tissue

International Nuclear Information System (INIS)

Wang, Jun Kit; Luo, Baiwen; Guneta, Vipra; Li, Liang; Foo, Selin Ee Min; Dai, Yun; Tan, Timothy Thatt Yang; Tan, Nguan Soon; Choong, Cleo; Wong, Marcus Thien Chong

2017-01-01

Adipose tissue is a rich source of extracellular matrix (ECM) material that can be isolated by delipidating and decellularizing the tissue. However, the current delipidation and decellularization methods either involve tedious and lengthy processes or require toxic chemicals, which may result in the elimination of vital proteins and growth factors found in the ECM. Hence, an alternative delipidation and decellularization method for adipose tissue was developed using supercritical carbon dioxide (SC-CO 2 ) that eliminates the need of any harsh chemicals and also reduces the amount of processing time required. The resultant SC-CO 2 -treated ECM material showed an absence of nuclear content but the preservation of key proteins such as collagen Type I, collagen Type III, collagen Type IV, elastin, fibronectin and laminin. In addition, other biological factors such as glycosaminoglycans (GAGs) and growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were also retained. Subsequently, the resulting SC-CO 2 -treated ECM material was used as a bioactive coating on tissue culture plastic (TCP). Four different cell types including adipose tissue-derived mesenchymal stem cells (ASCs), human umbilical vein endothelial cells (HUVECs), immortalized human keratinocyte (HaCaT) cells and human monocytic leukemia cells (THP-1) were used in this study to show that the SC-CO 2 -treated ECM coating can be potentially used for various biomedical applications. The SC-CO 2 -treated ECM material showed improved cell-material interactions for all cell types tested. In addition, in vitro scratch wound assay using HaCaT cells showed that the presence of SC-CO 2 -treated ECM material enhanced keratinocyte migration whilst the in vitro cellular studies using THP-1-derived macrophages showed that the SC-CO 2 -treated ECM material did not evoke pro-inflammatory responses from the THP-1-derived macrophages. Overall, this study shows the efficacy

Influence of nano-AlN particles on thermal conductivity, thermal stability and cure behavior of cycloaliphatic epoxy/trimethacrylate system

Directory of Open Access Journals (Sweden)

2011-02-01

Full Text Available We have prepared a series of nano-sized aluminium nitride (nano-AlN/cycloaliphatic epoxy/trimethacrylate (TMPTMA systems and investigated their morphology, thermal conductivity, thermal stability and curing behavior. Experimental results show that the thermal conductivity of composites increases with the nano-AlN filler content, the maximum value is up to 0.47 W/(m.K. Incorporation of a small amount of the nano-AlN filler into the epoxy/TMPTMA system improves the thermal stability. For instance, the thermal degradation temperature at 5% weight loss of nano-AlN/epoxy/TMPTMA system with only 1 wt% nano-AlN was improved by ~8ºC over the neat epoxy/TMPTMA system. The effect of nano-AlN particles on the cure behavior of epoxy/TMPTMA systems was studied by dynamic differential scanning calorimetry. The results showed that the addition of silane treated nano-AlN particles does not change the curing reaction mechanism and silane treated nano-AlN particles could bring positive effect on the processing of composite since it needs shorter pre-cure time and lower pre-temperature, meanwhile the increase of glass transition temperature of the nanocomposite improves the heat resistance.

SEM evaluation of the morphological changes in hard dental tissues prepared by Er: YAG laser and rotary instruments

Directory of Open Access Journals (Sweden)

Tomov Georgi

2010-09-01

Full Text Available Effective ablation of dental hard tissues by means of the erbium:yttrium-aluminum garnet (Er: YAG laser has been reported recently, and its application to caries removal and cavity preparation has been expected. However, few studies have investigated the morphological changes in hard dental tissues after Er: YAG laser caries treatment. In the present study the morphological changes in hard dental tissues after Er: YAG laser caries ablation in vitro was compared with that of conventional mechanical treatment. Thirty extracted human teeth with caries were used. Ten tooth was treated with the Er: YAG laser, and the other was treated with a conventional steel and diamond burs. Laser treatment was performed by means of a non-contact irradiation modes with cooling water spray, with a new Er: YAG laser (LiteTouch. Conventional bur treatment was conducted by means of a low-speed micromotor and air turbine with water cooling. Scanning electron microscope (SEM observations were performed for each treatment. The Er: YAG laser ablated carious dentin effectively with minimal thermal damage to the surrounding intact dentin, and removed infected and softened carious dentin to the same degree as the burtreatment. In addition, a lower degree of vibration was noted with the Er: YAG laser treatment. The SEM examination revealed characteristic micro-irregularities of the lased dentin and enamel surfaces with potential benefits for adhesive restorations. Our results show that the Er: YAG laser is promising as a new technical modality for caries treatment

{sup 99}Mo sorption by thermally treated hydrotalcites

Energy Technology Data Exchange (ETDEWEB)

Serrano, J.; Bertin, V.; Bulbulian, S.

2000-04-04

MoO{sub 4}{sup {minus}2} ions were sorbed in calcined hydrotalcite contained in a column. It was found that 98% of {sup 99m}Tc formed by {sup 99}Mo decay was eluted through the column in the form of pertechnetate. The content of radionuclides was determined by {gamma}-spectrometry, and natural molybdenum was measured by neutron activation analysis. Solids were characterized by thermal analysis, X-ray diffraction, and infrared spectroscopy. Through batch experiments, the hydrotalcite capacity toward molybdate ions (1.12 x 10{sup {minus}3} M) was found to be 3.2 mequiv g{sup {minus}1}. It was found that the high molybdate adsorbing capacity of calcined hydrotalcite could be utilized in designing a {sup 99m}Tc generator made with low specific activity {sup 99}Mo-molybdate samples.

Symptomatic heterotopic suprarenal splenic tissue

International Nuclear Information System (INIS)

Heider, J.; Kreft, B.; Winter, P.

1998-01-01

We report on a 33-year-old man with symptomatic heterotopic suprarenal splenic tissue. Heterotopic splenic tissue can often be found after posttraumatic splenectomy. It is a result of autotransplantation induced by trauma (splenosis). Additionally it can grow during embryogenic development. Such an accessory spleen is found in 10-44% of all autopsies. In this case report the patient was treated by resection due to increasing flank pain and suspected neoplasm. (orig.) [de

Subepithelial connective tissue graft with and without the use of plasma rich in growth factors for treating root exposure

Science.gov (United States)

Lafzi, Ardeshir; Shirmohammadi, Adileh; Behrozian, Ahmad; Kashefimehr, Atabak; Khashabi, Ehsan

2012-01-01

Purpose The aim of this study was to evaluate the clinical efficiency of the subepithelial connective tissue graft (SCTG) with and without plasma rich in growth factor (PRGF) in the treatment of gingival recessions. Methods Twenty bilateral buccal gingival Miller's Class I and II recessions were selected. Ten of the recessions were treated with SCTG and PRGF (test group). The rest ten of the recessions were treated with SCTG (control group). The clinical parameters including recession depth (RD), percentage of root coverage (RC), mucogingival junction (MGJ) position, clinical attachment level (CAL), and probing depth (PD) were measured at the baseline, and 1 and 3 months later. The data were analyzed using the Wilcoxon signed rank and Mann-Whitney U tests. Results After 3 months, both groups showed a significant improvement in all of the mentioned criteria except PD. Although the amount of improvement was better in the SCTG+PRGF group than the SCTG only group, this difference was not statistically significant. The mean RC was 70.85±12.57 in the test group and 75.83±24.68 in the control group. Conclusions Both SCTG+PRGF and SCTG only result in favorable clinical outcomes, but the added benefit of PRGF is not evident. PMID:23346462

Shape memory alloy fixator system for suturing tissue in minimal access surgery.

Science.gov (United States)

Xu, W; Frank, T G; Stockham, G; Cuschieri, A

1999-01-01

A new technique for suturing human tissue is described in which tissue closure is achieved by means of small fixators made from shape memory alloy. The aim of the development is to provide an alternative to thread suturing in minimal access surgery, which is quicker and requires less skill to achieve the required suturing quality. The design of the fixators is described in terms of the thermal shape recovery of shape memory alloy and a novel form of finite element analysis, which uses a nonlinear elastic element for the material property. Thermal analysis of the fixators and surrounding tissue is used to predict the temperature distribution during and after the application of electric current heating. This was checked in an in vitro experiment, which confirmed that deployment caused no detectable collateral damage to surrounding tissue. In vivo animal studies on the use of the shape memory alloy fixator for suturing tissue are ongoing to establish safety and healing effects.

Preliminary laboratory investigation of thermally treated recycled concrete aggregate for general use in concrete

NARCIS (Netherlands)

Larbi, J.A.; Heijnen, W.M.M.; Brouwer, J.P.; Mulder, E.

2000-01-01

This paper deals with a preliminary laboratory study to assess the effectiveness of thermal treatment methods to improve the quality of recycled concrete aggregate. The samples used for the study consisted of sieved fractions of crushed concrete that were subjected to various thermal treatments at

Optimization and real-time control for laser treatment of heterogeneous soft tissues.

Science.gov (United States)

Feng, Yusheng; Fuentes, David; Hawkins, Andrea; Bass, Jon M; Rylander, Marissa Nichole

2009-01-01

Predicting the outcome of thermotherapies in cancer treatment requires an accurate characterization of the bioheat transfer processes in soft tissues. Due to the biological and structural complexity of tumor (soft tissue) composition and vasculature, it is often very difficult to obtain reliable tissue properties that is one of the key factors for the accurate treatment outcome prediction. Efficient algorithms employing in vivo thermal measurements to determine heterogeneous thermal tissues properties in conjunction with a detailed sensitivity analysis can produce essential information for model development and optimal control. The goals of this paper are to present a general formulation of the bioheat transfer equation for heterogeneous soft tissues, review models and algorithms developed for cell damage, heat shock proteins, and soft tissues with nanoparticle inclusion, and demonstrate an overall computational strategy for developing a laser treatment framework with the ability to perform real-time robust calibrations and optimal control. This computational strategy can be applied to other thermotherapies using the heat source such as radio frequency or high intensity focused ultrasound.

Microjet-assisted dye-enhanced diode laser ablation of cartilaginous tissue

Science.gov (United States)

Pohl, John; Bell, Brent A.; Motamedi, Massoud; Frederickson, Chris J.; Wallace, David B.; Hayes, Donald J.; Cowan, Daniel

1994-08-01

Recent studies have established clinical application of laser ablation of cartilaginous tissue. The goal of this study was to investigate removal of cartilaginous tissue using diode laser. To enhance the interaction of laser light with tissue, improve the ablation efficiency and localize the extent of laser-induced thermal damage in surrounding tissue, we studied the use of a novel delivery system developed by MicroFab Technologies to dispense a known amount of Indocyanine Green (ICG) with a high spatial resolution to alter the optical properties of the tissue in a controlled fashion. Canine intervertebral disks were harvested and used within eight hours after collection. One hundred forty nL of ICG was topically applied to both annulus and nucleus at the desired location with the MicroJet prior to each irradiation. Fiber catheters (600 micrometers ) were used and positioned to irradiate the tissue with a 0.8 mm spot size. Laser powers of 3 - 10 W (Diomed, 810 nm) were used to irradiate the tissue with ten pulses (200 - 500 msec). Discs not stained with ICG were irradiated as control samples. Efficient tissue ablation (80 - 300 micrometers /pulse) was observed using ICG to enhance light absorption and confine thermal damage while there was no observable ablation in control studied. The extent of tissue damage observed microscopically was limited to 50 - 100 micrometers . The diode laser/Microjet combination showed promise for applications involving removal of cartilaginous tissue. This procedure can be performed using a low power compact diode laser, is efficient, and potentially more economical compared to procedures using conventional lasers.

Bioheat model evaluations of laser effects on tissues: role of water evaporation and diffusion

Science.gov (United States)

Nagulapally, Deepthi; Joshi, Ravi P.; Thomas, Robert J.

2011-03-01

A two-dimensional, time-dependent bioheat model is applied to evaluate changes in temperature and water content in tissues subjected to laser irradiation. Our approach takes account of liquid-to-vapor phase changes and a simple diffusive flow of water within the biotissue. An energy balance equation considers blood perfusion, metabolic heat generation, laser absorption, and water evaporation. The model also accounts for the water dependence of tissue properties (both thermal and optical), and variations in blood perfusion rates based on local tissue injury. Our calculations show that water diffusion would reduce the local temperature increases and hot spots in comparison to simple models that ignore the role of water in the overall thermal and mass transport. Also, the reduced suppression of perfusion rates due to tissue heating and damage with water diffusion affect the necrotic depth. Two-dimensional results for the dynamic temperature, water content, and damage distributions will be presented for skin simulations. It is argued that reduction in temperature gradients due to water diffusion would mitigate local refractive index variations, and hence influence the phenomenon of thermal lensing. Finally, simple quantitative evaluations of pressure increases within the tissue due to laser absorption are presented.

Non-invasive tissue temperature measurements based on quantitative diffuse optical spectroscopy (DOS) of water

Energy Technology Data Exchange (ETDEWEB)

Chung, S H [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Cerussi, A E; Tromberg, B J [Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road, Irvine 92612, CA (United States); Merritt, S I [Masimo Corporation, 40 Parker, Irvine, CA 92618 (United States); Ruth, J, E-mail: bjtrombe@uci.ed [Department of Bioengineering, University of Pennsylvania, 210 S. 33rd Street, Room 240, Skirkanich Hall, Philadelphia, PA 19104 (United States)

2010-07-07

We describe the development of a non-invasive method for quantitative tissue temperature measurements using Broadband diffuse optical spectroscopy (DOS). Our approach is based on well-characterized opposing shifts in near-infrared (NIR) water absorption spectra that appear with temperature and macromolecular binding state. Unlike conventional reflectance methods, DOS is used to generate scattering-corrected tissue water absorption spectra. This allows us to separate the macromolecular bound water contribution from the thermally induced spectral shift using the temperature isosbestic point at 996 nm. The method was validated in intralipid tissue phantoms by correlating DOS with thermistor measurements (R = 0.96) with a difference of 1.1 {+-} 0.91 {sup 0}C over a range of 28-48 {sup 0}C. Once validated, thermal and hemodynamic (i.e. oxy- and deoxy-hemoglobin concentration) changes were measured simultaneously and continuously in human subjects (forearm) during mild cold stress. DOS-measured arm temperatures were consistent with previously reported invasive deep tissue temperature studies. These results suggest that DOS can be used for non-invasive, co-registered measurements of absolute temperature and hemoglobin parameters in thick tissues, a potentially important approach for optimizing thermal diagnostics and therapeutics.

A biphasic model for bleeding in soft tissue

Science.gov (United States)

Chang, Yi-Jui; Chong, Kwitae; Eldredge, Jeff D.; Teran, Joseph; Benharash, Peyman; Dutson, Erik

2017-11-01

The modeling of blood passing through soft tissues in the body is important for medical applications. The current study aims to capture the effect of tissue swelling and the transport of blood under bleeding or hemorrhaging conditions. The soft tissue is considered as a non-static poro-hyperelastic material with liquid-filled voids. A biphasic formulation effectively, a generalization of Darcy's law-is utilized, treating the phases as occupying fractions of the same volume. The interaction between phases is captured through a Stokes-like friction force on their relative velocities and a pressure that penalizes deviations from volume fractions summing to unity. The soft tissue is modeled as a hyperelastic material with a typical J-shaped stress-strain curve, while blood is considered as a Newtonian fluid. The method of Smoothed Particle Hydrodynamics is used to discretize the conservation equations based on the ease of treating free surfaces in the liquid. Simulations of swelling under acute hemorrhage and of draining under gravity and compression will be demonstrated. Ongoing progress in modeling of organ tissues under injuries and surgical conditions will be discussed.

The value of 99mTc-HDP scan in the diagnosis of tibial avascular necrosis caused by thermal injury: a case with multi-image correlation analysis

International Nuclear Information System (INIS)

Bahk, Yong Whee

2007-01-01

Basic pathology in thermal injury is coagulative soft tissue necorsis that may occasionally be complicated by infection and later by scarring and vascular changes. Radiological features were discussed in detail by Resnick. The early changes consist of soft tissue defect, porosis and periostitis and the late changes include osteophytosis, periarticular calcification or ossification and arthropathy with ankylosis. Acromutilation can occur when small bones of the hand and foot are burned and scarred. This communication describes 99m Tc-HDP pnhole bone scan manifestations of thermal bone injuries observed in a case of skin-bone burns of the mid-tibial shaft that was complicated by infection, soft tissue scarring and osteonecrosis. Patient was a 49-year-old female thermal burn involving a mid-tibial shaft segment along with overlying skin. The injury was accidental to medullary rimming to fit intramedullary nail to fix fracture. The heat produced during drilling spread to burn the pretibial skin that is sparse in subcutaneous buffer tissue and vessels. The soft tissue burn was infected and healed by repeated skin grafts and scar over a period of 2 years. Concomitantly, the underlying bone was infected locally and treated but ensued in osteonecrosis that was accompanied by osteolysis. Indeed. pinhole 99m Tc-HDP scan played a unique role in this case in detecting that live lateral cortex had sustained the large dead bone that involved the main volume of the mid-tibial shaft. Importantly, the scan could confirm live cortex to have sustained dead bone uncollapsed. Anatomical and metabolic data gained from bone scanning prompted us to systematically scrutinize radiograph and CT to specifically identify the preserved lateral cortex. As mentioned the existence of healthy cortex is biomechanically and tactically vital to surgically replace and restore the devitalized bone

Polymer scaffolds with no skin-effect for tissue engineering applications fabricated by thermally induced phase separation

International Nuclear Information System (INIS)

Kasoju, Naresh; Kubies, Dana; Sedlačík, Tomáš; Kumorek, Marta M.; Rypáček, František; Janoušková, Olga; Koubková, Jana

2016-01-01

Thermally induced phase separation (TIPS) based methods are widely used for the fabrication of porous scaffolds for tissue engineering and related applications. However, formation of a less-/non-porous layer at the scaffold’s outer surface at the air–liquid interface, often known as the skin-effect, restricts the cell infiltration inside the scaffold and therefore limits its efficacy. To this end, we demonstrate a TIPS-based process involving the exposure of the just quenched poly(lactide-co-caprolactone):dioxane phases to the pure dioxane for a short time while still being under the quenching strength, herein after termed as the second quenching (2Q). Scanning electron microscopy, mercury intrusion porosimetry and contact angle analysis revealed a direct correlation between the time of 2Q and the gradual disappearance of the skin, followed by the widening of the outer pores and the formation of the fibrous filaments over the surface, with no effect on the internal pore architecture and the overall porosity of scaffolds. The experiments at various quenching temperatures and polymer concentrations revealed the versatility of 2Q in removing the skin. In addition, the in vitro cell culture studies with the human primary fibroblasts showed that the scaffolds prepared by the TIPS based 2Q process, with the optimal exposure time, resulted in a higher cell seeding and viability in contrast to the scaffolds prepared by the regular TIPS. Thus, TIPS including the 2Q step is a facile, versatile and innovative approach to fabricate the polymer scaffolds with a skin-free and fully open porous surface morphology for achieving a better cell response in tissue engineering and related applications. (paper)

A comparative study of the physical properties of Sb2S3 thin films treated with N2 AC plasma and thermal annealing in N2

International Nuclear Information System (INIS)

Calixto-Rodriguez, M.; Martinez, H.; Pena, Y.; Flores, O.; Esparza-Ponce, H.E.; Sanchez-Juarez, A.; Campos-Alvarez, J.; Reyes, P.

2010-01-01

As-deposited antimony sulfide thin films prepared by chemical bath deposition were treated with nitrogen AC plasma and thermal annealing in nitrogen atmosphere. The as-deposited, plasma treated, and thermally annealed antimony sulfide thin films have been characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy, scanning electron microscopy, atomic force microscopy, UV-vis spectroscopy, and electrical measurements. The results have shown that post-deposition treatments modify the crystalline structure, the morphology, and the optoelectronic properties of Sb 2 S 3 thin films. X-ray diffraction studies showed that the crystallinity of the films was improved in both cases. Atomic force microscopy studies showed that the change in the film morphology depends on the post-deposition treatment used. Optical emission spectroscopy (OES) analysis revealed the plasma etching on the surface of the film, this fact was corroborated by the energy dispersive X-ray spectroscopy analysis. The optical band gap of the films (E g ) decreased after post-deposition treatments (from 2.36 to 1.75 eV) due to the improvement in the grain sizes. The electrical resistivity of the Sb 2 S 3 thin films decreased from 10 8 to 10 6 Ω-cm after plasma treatments.

Thermal expansion anomaly and thermal conductivity of U3O8

International Nuclear Information System (INIS)

Schulz, B.

1975-01-01

The anomaly in the thermal expansion of U 3 O 8 and results of the thermal conductivity of this compound are described. U 3 O 8 powder heat treated at 1,223 K was consolidated by pressing and sintering in air at 1,223 and 1,373 K to a density of 66% and 80.8% TD. The O/U ratio was 2.67 and 2.63 respectively, the crystal structure being orthorhombic in both cases. For UOsub(2.63) the thermal linear expansion was measured in the temperature range 293 K-1,063 K in pressing direction and normal to it, while for UOsub(2.67) measurements were done parallel to the pressing direction. The curves of the linear thermal expansion from 373 K up to 623 K show negative values and above positive for the three curves. The results are related to known data of phase-transition-temperatures of the orthorhombic U 3 O 8 . Measurements of the thermal conductivity were done on UOsub(2.67). Because of the high porosity of the samples, known relationships for the porosity correction of the thermal conductivity were proved on alumina with 34 % porosity. The values of the thermal conductivity of UOsub(2.67) (corrected to zero porosity) show a very slight temperature dependence, they are about three times lower than those of the stoichiometric uranium dioxide in the same temperature range

Study on thermal conductive BN/novolac resin composites

International Nuclear Information System (INIS)

Li, Shasha; Qi, Shuhua; Liu, Nailiang; Cao, Peng

2011-01-01

Highlights: → Boron nitride (BN) particles were used to modify novolac resin. → BN particles were pretreated by γ-aminopropyltriethoxysilane. → The thermal conductivity trend of composite almost agrees with the predicted data from the Maxwell-Eucken model. → At BN concentration of 80 wt.%, thermal conductivity value of composite is 4.5 times that of pure novolac resin. → Combined use of the larger and smaller particles with a mass ratio of 1:2 provides the composites with the maximum thermal conductivity among the testing systems. → The composite thermal property also increases with an increase in the BN concentration. - Abstract: In this study, γ-aminopropyltriethoxysilane-treated boron nitride (BN) particles were used to modify novolac resin. The effect of varying the BN concentration, particle size, and hybrid BN fillers with the binary particle size distribution on the thermal conductivity of the composites was investigated. Scanning electron microscopy (SEM) imaging showed homogeneously dispersed treated BN particles in the matrix. Furthermore, the thermal conductivity increased as the BN concentration was increased. This behavior was also observed when the filler size was increased. Experimentally obtained thermal conductivity values agree with the predicted data from the Maxwell-Eucken model well at less than 70 wt.% BN loading. A larger particle size BN-filled novolac resin exhibits a higher thermal conductivity than a smaller particle size BN-filled one. The combined use of 0.5 and 15 μm particles with a mass ratio of 2:1 achieved the maximum thermal conductivity among the testing systems. The thermal resistance properties of the composites were also studied.

Spectroscopic and thermal characterization of bovine enamel and dentine using the photoacoustic effect

International Nuclear Information System (INIS)

Stolf, Sandro Fernando

2003-01-01

The optical and thermal properties of dental tissues determine the nature and extent of the tissue response through the processes of absorption, transmission, reflection and scattering of the laser light and the heat produced by the absorption of that light. The spectroscopic characterization of bovine dentine and enamel, and the determination of the thermal diffusivity were the aim of this study. The photoacoustic spectra from these tissues were obtained in the Near-Infrared range 900 - 2500 nm, which is the clinical range for odontological application of most lasers. Photoacoustic spectra were taken from block, slices and powder of enamel and dentine. Also photoacoustic spectra were registered before and after 2, 5 and 10 h of topical fluoride (2.26%) application. Using the same technique spectra were taken from dentine and enamel after irradiation with Nd:YAG, Er:YAG, Ho:YLF and CO 2 . It is evident from the results that the presence of O-H in the composition of hydroxyapatite and the water present in the teeth tissue make the obtention of spectrum from components other than O-H bond a very difficult task. In this way, only bands assigned to overtones and combinations of O-H stretch were observed. The thermal diffusivity of the bovine dentine was also measured using the photoacoustic technique. The thermal diffusivity is the physical quantity which measures the rate of heat diffusion throughout the sample. For higher values of the thermal diffusivity the heat diffusion and temperature rise will be faster. As there is many studies devoted to the processes of heat transfer throughout dental tissues using bovine teeth, it is important the determination of its thermal diffusivity. The measured value was found to be a = 2.0 (±0.1).1O -3 cm 2 /s for the both direction, perpendicular and parallel to the dentinal tubules. These a lues indicate that there is no difference between the thermal diffusivities for the both directions. (author)

Revisiting the effects of organic solvents on the thermal reduction of graphite oxide

International Nuclear Information System (INIS)

Barroso-Bujans, Fabienne; Fierro, José Luis G.; Alegría, Angel; Colmenero, Juan

2011-01-01

Highlights: ► Retention of organic solvent on graphite oxide interlayer space. ► Decreasing exfoliation temperature. ► Close link between structure and thermal behavior of solvent treated graphite oxide. ► Restacking inhibition of thermally reduced graphite oxide sheets. ► Changes in kinetic mechanisms of thermal reduction. - Abstract: Treatment of graphite oxide (GO) with organic solvents via sorption from either liquid or gas phase, and subsequent desorption, induces profound changes in the layered GO structure: loss of stacking order, retention of trace amounts of solvents and decreasing decomposition temperature. This study presents new evidences of the effect of organic solvents on the thermal reduction of GO by means of thermogravimetric analysis, X-ray diffraction and X-ray photoelectron spectroscopy. The results reveal a relative higher decrease of the oxygen amounts in solvent-treated GO as compared to untreated GO and the restacking inhibition of the thermally reduced GO sheets upon slow heating. The kinetic experiments evidence changes occurring in the reduction mechanisms of the solvent-treated GO, which support the close link between GO structure and thermal properties.

Two-photon induced collagen cross-linking in bioartificial cardiac tissue

Science.gov (United States)

Kuetemeyer, Kai; Kensah, George; Heidrich, Marko; Meyer, Heiko; Martin, Ulrich; Gruh, Ina; Heisterkamp, Alexander

2011-08-01

Cardiac tissue engineering is a promising strategy for regenerative therapies to overcome the shortage of donor organs for transplantation. Besides contractile function, the stiffness of tissue engineered constructs is crucial to generate transplantable tissue surrogates with sufficient mechanical stability to withstand the high pressure present in the heart. Although several collagen cross-linking techniques have proven to be efficient in stabilizing biomaterials, they cannot be applied to cardiac tissue engineering, as cell death occurs in the treated area. Here, we present a novel method using femtosecond (fs) laser pulses to increase the stiffness of collagen-based tissue constructs without impairing cell viability. Raster scanning of the fs laser beam over riboflavin-treated tissue induced collagen cross-linking by two-photon photosensitized singlet oxygen production. One day post-irradiation, stress-strain measurements revealed increased tissue stiffness by around 40% being dependent on the fibroblast content in the tissue. At the same time, cells remained viable and fully functional as demonstrated by fluorescence imaging of cardiomyocyte mitochondrial activity and preservation of active contraction force. Our results indicate that two-photon induced collagen cross-linking has great potential for studying and improving artificially engineered tissue for regenerative therapies.

Detection of Chlamydia in postmortal formalin-fixed tissue

DEFF Research Database (Denmark)

Lundemose, AG; Lundemose, JB; Birkelund, Svend

1989-01-01

A procedure to detect Chlamydia in postmortal formalin-fixed tissue is described. Monoclonal antibodies against a genus specific chlamydia epitope were used in immunofluorescence to detect chlamydia inclusions in formalin-fixed tissue sections. Lung sections from chlamydia-infected mice were....... Background and non-specific fluorescence were reduced by treating the tissue sections with trypsin, rabbit serum and Evans blue counterstain. Besides giving an exact diagnosis at autopsy, the method provides the possibility of determining the occurrence of chlamydia infections in various tissues, based...

The use of animal tissues alongside human tissue: Cultural and ethical considerations.

Science.gov (United States)

Kaw, Anu; Jones, D Gareth; Zhang, Ming

2016-01-01

Teaching and research facilities often use cadaveric material alongside animal tissues, although there appear to be differences in the way we handle, treat, and dispose of human cadaveric material compared to animal tissue. This study sought to analyze cultural and ethical considerations and provides policy recommendations on the use of animal tissues alongside human tissue. The status of human and animal remains and the respect because of human and animal tissues were compared and analyzed from ethical, legal, and cultural perspectives. The use of animal organs and tissues is carried out within the context of understanding human anatomy and function. Consequently, the interests of human donors are to be pre-eminent in any policies that are enunciated, so that if any donors find the presence of animal remains unacceptable, the latter should not be employed. The major differences appear to lie in differences in our perceptions of their respective intrinsic and instrumental values. Animals are considered to have lesser intrinsic value and greater instrumental value than humans. These differences stem from the role played by culture and ethical considerations, and are manifested in the resulting legal frameworks. In light of this discussion, six policy recommendations are proposed, encompassing the nature of consent, respect for animal tissues as well as human remains, and appropriate separation of both sets of tissues in preparation and display. © 2015 Wiley Periodicals, Inc.

Tissue Acoustoelectric Effect Modeling From Solid Mechanics Theory.

Science.gov (United States)

Song, Xizi; Qin, Yexian; Xu, Yanbin; Ingram, Pier; Witte, Russell S; Dong, Feng

2017-10-01

The acoustoelectric (AE) effect is a basic physical phenomenon, which underlies the changes made in the conductivity of a medium by the application of focused ultrasound. Recently, based on the AE effect, several biomedical imaging techniques have been widely studied, such as ultrasound-modulated electrical impedance tomography and ultrasound current source density imaging. To further investigate the mechanism of the AE effect in tissue and to provide guidance for such techniques, we have modeled the tissue AE effect using the theory of solid mechanics. Both bulk compression and thermal expansion of tissue are considered and discussed. Computation simulation shows that the muscle AE effect result, conductivity change rate, is 3.26×10 -3 with 4.3-MPa peak pressure, satisfying the theoretical value. Bulk compression plays the main role for muscle AE effect, while thermal expansion makes almost no contribution to it. In addition, the AE signals of porcine muscle are measured at different focal positions. With the same magnitude order and the same change trend, the experiment result confirms that the simulation result is effective. Both simulation and experimental results validate that tissue AE effect modeling using solid mechanics theory is feasible, which is of significance for the further development of related biomedical imaging techniques.

The value of {sup 99m}Tc-HDP scan in the diagnosis of tibial avascular necrosis caused by thermal injury: a case with multi-image correlation analysis

Energy Technology Data Exchange (ETDEWEB)

Bahk, Yong Whee [Sung-Ae General Hospital, Seoul (Korea, Republic of)

2007-10-15

Basic pathology in thermal injury is coagulative soft tissue necorsis that may occasionally be complicated by infection and later by scarring and vascular changes. Radiological features were discussed in detail by Resnick. The early changes consist of soft tissue defect, porosis and periostitis and the late changes include osteophytosis, periarticular calcification or ossification and arthropathy with ankylosis. Acromutilation can occur when small bones of the hand and foot are burned and scarred. This communication describes {sup 99m}Tc-HDP pnhole bone scan manifestations of thermal bone injuries observed in a case of skin-bone burns of the mid-tibial shaft that was complicated by infection, soft tissue scarring and osteonecrosis. Patient was a 49-year-old female thermal burn involving a mid-tibial shaft segment along with overlying skin. The injury was accidental to medullary rimming to fit intramedullary nail to fix fracture. The heat produced during drilling spread to burn the pretibial skin that is sparse in subcutaneous buffer tissue and vessels. The soft tissue burn was infected and healed by repeated skin grafts and scar over a period of 2 years. Concomitantly, the underlying bone was infected locally and treated but ensued in osteonecrosis that was accompanied by osteolysis. Indeed. pinhole {sup 99m}Tc-HDP scan played a unique role in this case in detecting that live lateral cortex had sustained the large dead bone that involved the main volume of the mid-tibial shaft. Importantly, the scan could confirm live cortex to have sustained dead bone uncollapsed. Anatomical and metabolic data gained from bone scanning prompted us to systematically scrutinize radiograph and CT to specifically identify the preserved lateral cortex. As mentioned the existence of healthy cortex is biomechanically and tactically vital to surgically replace and restore the devitalized bone.

Treating chancroid with enoxacin.

Science.gov (United States)

Naamara, W; Kunimoto, D Y; D'Costa, L J; Ndinya-Achola, J O; Nsanze, H; Ronald, A R; Plummer, F A

1988-01-01

Increasing resistance of Haemophilus ducreyi to antimicrobials necessitates further trials of new antimicrobial agents for treating chancroid. Enoxacin has excellent in vitro activity against H ducreyi, and a randomised clinical trial of three doses of enoxacin 400 mg at intervals of 12 hours compared with a single dose of trimethoprim/sulphametrole (TMP/SMT) 640/3200 mg was therefore conducted. Of 169 men enrolled in the study, 86 received enoxacin and 83 received TMP/SMT. Ulcers were improved or cured in 65/73 men treated with enoxacin and 57/70 men treated with TMP/SMT. This difference was not significant. At 72 hours after treatment, H ducreyi was eradicated from ulcers of 72/77 men treated with enoxacin and of 67/74 of those treated with TMP/SMT. Patients with buboes responded equally well to both treatments. Of 100 H ducreyi strains tested, all were susceptible to both 0.25 mg/l enoxacin and the combination of 0.25 mg/l TMP and 5 mg/l SMT. Although most men treated with either regimen were cured, neither regimen appeared to be the optimum treatment for chancroid. This study shows the efficacy of enoxacin for a soft tissue infection caused by Gram negative organisms. PMID:3044978

A Micro-Thermal Sensor for Focal Therapy Applications

Science.gov (United States)

Natesan, Harishankar; Hodges, Wyatt; Choi, Jeunghwan; Lubner, Sean; Dames, Chris; Bischof, John

2016-02-01

There is an urgent need for sensors deployed during focal therapies to inform treatment planning and in vivo monitoring in thin tissues. Specifically, the measurement of thermal properties, cooling surface contact, tissue thickness, blood flow and phase change with mm to sub mm accuracy are needed. As a proof of principle, we demonstrate that a micro-thermal sensor based on the supported “3ω” technique can achieve this in vitro under idealized conditions in 0.5 to 2 mm thick tissues relevant to cryoablation of the pulmonary vein (PV). To begin with “3ω” sensors were microfabricated onto flat glass as an idealization of a focal probe surface. The sensor was then used to make new measurements of ‘k’ (W/m.K) of porcine PV, esophagus, and phrenic nerve, all needed for PV cryoabalation treatment planning. Further, by modifying the sensor use from traditional to dynamic mode new measurements related to tissue vs. fluid (i.e. water) contact, fluid flow conditions, tissue thickness, and phase change were made. In summary, the in vitro idealized system data presented is promising and warrants future work to integrate and test supported “3ω” sensors on in vivo deployed focal therapy probe surfaces (i.e. balloons or catheters).

Tissue Engineering of the Penis

Directory of Open Access Journals (Sweden)

Manish N. Patel

2011-01-01

Full Text Available Congenital disorders, cancer, trauma, or other conditions of the genitourinary tract can lead to significant organ damage or loss of function, necessitating eventual reconstruction or replacement of the damaged structures. However, current reconstructive techniques are limited by issues of tissue availability and compatibility. Physicians and scientists have begun to explore tissue engineering and regenerative medicine strategies for repair and reconstruction of the genitourinary tract. Tissue engineering allows the development of biological substitutes which could potentially restore normal function. Tissue engineering efforts designed to treat or replace most organs are currently being undertaken. Most of these efforts have occurred within the past decade. However, before these engineering techniques can be applied to humans, further studies are needed to ensure the safety and efficacy of these new materials. Recent progress suggests that engineered urologic tissues and cell therapy may soon have clinical applicability.

[Clinical effect modified Chevron osteotomy combined with lateral tissue loosening in treating mild-moderate hallux valgus through internal signal approach].

Science.gov (United States)

Chen, Xue-Qiang; Wu, Qun-Feng; Dong, Wei-Qin; Yu, Li-Xin; Li, Xiong-Feng

2018-03-25

To explore clinical effect of modified Chevron osteotomy combined with lateral tissue loosening for the treatment of mild-moderate hallux valgus through internal signal approach. From July 2015 to June 2016, 26 patients with mild-moderate hallux valgus treated with modified Chevron osteotomy combined with lateral tissue loosening through internal signal approach, including 2 males and 24 females aged from 45 to 65 years old with an average of(54.6±4.8) years old;the courses of diseases ranged from 1 to 5 months with an average of (7.5±3.3) months. Hallux valgus angle(HVA), inter metatarsal angle(IMA) were measured at 12 months after operation, and AOFAS score was applied to evaluate clinical effect before and after operation. All incisions were healed at stage I. No incision occurred infection, metatarsal necrosis and recurrence of hallux valgus deformity. Two patients occurred skin numbness caused by musculocutaneous nerve injury. Twenty-six patients were followed up from 6 to 12 months with an average of(9.12±2.06) months. HVA, IMA were(30.01±3.71)°, (14.00±1.50)° before operation and(9.41±4.16)°, (7.00±0.60)° after operation, which had significant difference. There was statistical significance in AOFAS score before operation 54.77±9.59 and after operation 92.73±5.47, and 19 cases obtained excellent results and 7 moderate. Modified Chevron osteotomy combined with full thread headless pressure screw fixation and lateral tissue loosening for the treatment of mild-moderate hallux valgus has advantages of excellent exposure, simple operation, stable fixation, rapid recovery. Akin osteotomy with internal capsulorrhaphy were used with lateral loosening and could recover soft tissue balance between lateral and internal, and could receive satisfied clinical effects. Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.

Wound trauma mediated inflammatory signaling attenuates a tissue regenerative response in MRL/MpJ mice

Directory of Open Access Journals (Sweden)

Elster Eric A

2010-05-01

Full Text Available Abstract Background Severe trauma can induce pathophysiological responses that have marked inflammatory components. The development of systemic inflammation following severe thermal injury has been implicated in immune dysfunction, delayed wound healing, multi-system organ failure and increased mortality. Methods In this study, we examined the impact of thermal injury-induced systemic inflammation on the healing response of a secondary wound in the MRL/MpJ mouse model, which was anatomically remote from the primary site of trauma, a wound that typically undergoes scarless healing in this specific strain. Ear-hole wounds in MRL/MpJ mice have previously displayed accelerated healing and tissue regeneration in the absence of a secondary insult. Results Severe thermal injury in addition to distal ear-hole wounds induced marked local and systemic inflammatory responses in the lungs and significantly augmented the expression of inflammatory mediators in the ear tissue. By day 14, 61% of the ear-hole wounds from thermally injured mice demonstrated extensive inflammation with marked inflammatory cell infiltration, extensive ulceration, and various level of necrosis to the point where a large percentage (38% had to be euthanized early during the study due to extensive necrosis, inflammation and ear deformation. By day 35, ear-hole wounds in mice not subjected to thermal injury were completely closed, while the ear-hole wounds in thermally injured mice exhibited less inflammation and necrosis and only closed partially (62%. Thermal injury resulted in marked increases in serum levels of IL-6, TNFα, KC (CXCL1, and MIP-2α (CXCL2. Interestingly, attenuated early ear wound healing in the thermally injured mouse resulted in incomplete tissue regeneration in addition to a marked inflammatory response, as evidenced by the histological appearance of the wound and increased transcription of potent inflammatory mediators. Conclusion These findings suggest that the

Prediction and measurement of thermally induced cambial tissue necrosis in tree stems

Science.gov (United States)

Joshua L. Jones; Brent W. Webb; Bret W. Butler; Matthew B. Dickinson; Daniel Jimenez; James Reardon; Anthony S. Bova

2006-01-01

A model for fire-induced heating in tree stems is linked to a recently reported model for tissue necrosis. The combined model produces cambial tissue necrosis predictions in a tree stem as a function of heating rate, heating time, tree species, and stem diameter. Model accuracy is evaluated by comparison with experimental measurements in two hardwood and two softwood...

Metabolic aspects of growth in HU-treated crown-gall tissue cultures. II. Helianthus annuus

Directory of Open Access Journals (Sweden)

Aldona Rennert

2015-01-01

Full Text Available The dynamics of growth and changes in nucleic acid and protein contents in sunflower calluses and tumours cultured in hydroxyurea (HU containing media were examined. HU-induced changes in healthy tissues ran in parallel always in the same direction, in tumourous ones however an uncoupling between DNA synthesis and tissue growth on one hand and RNA and protein synthesis on the other took place. A detailed analysis of the results allows to suppose that the specific activity of HU on tumourous tissue could be an index of: 1 quantitative disturbances in its genes function (2 degree of the lass of sensitivity to the factors of regulation.

Citric acid facilitated thermal treatment: An innovative method for the remediation of mercury contaminated soil

International Nuclear Information System (INIS)

Ma, Fujun; Peng, Changsheng; Hou, Deyi; Wu, Bin; Zhang, Qian; Li, Fasheng; Gu, Qingbao

2015-01-01

Highlights: • Hg content was reduced to <1.5 mg/kg when treated at 400 °C with citric acid. • The treated soil retained most of its original soil physicochemical properties. • Proton provided by citric acid facilitates thermal removal of mercury. • This thermal treatment method is expected to reduce energy input by 35%. - Abstract: Thermal treatment is a promising technology for the remediation of mercury contaminated soils, but it often requires high energy input at heating temperatures above 600 °C, and the treated soil is not suitable for agricultural reuse. The present study developed a novel method for the thermal treatment of mercury contaminated soils with the facilitation of citric acid (CA). A CA/Hg molar ratio of 15 was adopted as the optimum dosage. The mercury concentration in soils was successfully reduced from 134 mg/kg to 1.1 mg/kg when treated at 400 °C for 60 min and the treated soil retained most of its original soil physiochemical properties. During the treatment process, CA was found to provide an acidic environment which enhanced the volatilization of mercury. This method is expected to reduce energy input by 35% comparing to the traditional thermal treatment method, and lead to agricultural soil reuse, thus providing a greener and more sustainable remediation method for treating mercury contaminated soil in future engineering applications.

Citric acid facilitated thermal treatment: An innovative method for the remediation of mercury contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Ma, Fujun [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Peng, Changsheng [The Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Hou, Deyi [Geotechnical and Environmental Research Group, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ (United Kingdom); Wu, Bin; Zhang, Qian; Li, Fasheng [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Gu, Qingbao, E-mail: guqb@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)

2015-12-30

Highlights: • Hg content was reduced to <1.5 mg/kg when treated at 400 °C with citric acid. • The treated soil retained most of its original soil physicochemical properties. • Proton provided by citric acid facilitates thermal removal of mercury. • This thermal treatment method is expected to reduce energy input by 35%. - Abstract: Thermal treatment is a promising technology for the remediation of mercury contaminated soils, but it often requires high energy input at heating temperatures above 600 °C, and the treated soil is not suitable for agricultural reuse. The present study developed a novel method for the thermal treatment of mercury contaminated soils with the facilitation of citric acid (CA). A CA/Hg molar ratio of 15 was adopted as the optimum dosage. The mercury concentration in soils was successfully reduced from 134 mg/kg to 1.1 mg/kg when treated at 400 °C for 60 min and the treated soil retained most of its original soil physiochemical properties. During the treatment process, CA was found to provide an acidic environment which enhanced the volatilization of mercury. This method is expected to reduce energy input by 35% comparing to the traditional thermal treatment method, and lead to agricultural soil reuse, thus providing a greener and more sustainable remediation method for treating mercury contaminated soil in future engineering applications.

Effect of retinol on the hyperthermal response of normal tissue in vivo

International Nuclear Information System (INIS)

Rogers, M.A.; Marigold, J.C.L.; Hume, S.P.

1983-01-01

The effect of prior administration of retinol, a membrane labilizer, on the in vivo hyperthermal response of lysosomes was investigated in the mouse spleen using a quantitative histochemical assay for the lysosomal enzyme acid phosphatase. A dose of retinol which had no effect when given alone enhanced the thermal response of the lysosome, causing an increase in lysosomal membrane permeability. In contrast, the same dose of retinol had no effect on the gross hyperthermal response of mouse intestine; a tissue which is relatively susceptible to hyperthermia. Thermal damage to intestine was assayed directly by crypt loss 1 day after treatment or assessed as thermal enhancement of x-ray damage by counting crypt microcolonies 4 days after a combined heat and x-ray treatment. Thus, although the hyperthermal response of the lysosome could be enhanced by the administration of retinol, thermal damage at a gross tissue level appeared to be unaffected, suggesting that lysosomal membrane injury is unlikely to be a primary event in hyperthermal cell killing

Study of tissue engineered bone nodules by Fourier transform infrared spectroscopy.

Science.gov (United States)

Aydin, Halil Murat; Hu, Bin; Suso, Josep Sulé; El Haj, Alicia; Yang, Ying

2011-02-21

The key criteria for assessing the success of bone tissue engineering are the quality and quantity of the produced minerals within the cultured constructs. The accumulation of calcium ions and inorganic phosphates in culture medium serves as nucleating agents for the formation of hydroxyapatite, which is the main inorganic component of bone. Bone nodule formation is one of the hallmarks of mineralization in such cell cultures. In this study, we developed a new two-step procedure to accelerate bone formation in which mouse bone cell aggregates were produced first on various chemically treated non-adhesive substrates. After this step, the bone cells' growth and mineralization were followed in conventional culture plates. The number and size of cell aggregates were studied with light microscopy. The minerals' formation in the form of nodules produced by the cell aggregates and the bone crystal quality were studied with Fourier Transform Infrared (FTIR) spectroscopy. The FTIR spectra of the ash specimens (mineral phase only) from thermal gravimetric analysis (TGA) provided valuable information of the quality of the minerals. The υ(4) PO(4) region (550-650 cm(-1)), which reveals apatitic and non-apatitic HPO(4) or PO(4) environments, and phosphate region (910-1180 cm(-1)) were examined for the minerals produced in the form of nodules. The peak position and intensity of the spectra demonstrate that the quality of the bone produced by cell aggregates, especially from the bigger ones, which were formed on Plunoric treated substrates, exhibit a composition more similar to that of native bone. This work establishes a new protocol for high quality bone formation and characterization, with the potential to be applied to bone tissue engineering.

Thermal Plumes in Ventilated Rooms

DEFF Research Database (Denmark)

Kofoed, Peter

Axisymmeric circular buoyant jets are treated both theoretically and experimentally. From a literature study the author concludes that the state of experimental knowledge is less satisfactory. Further three different measuring methods have been established to investigate the thermal plumes from...

Influence of Gamma Aminobutyric Acid on Some Biochemical Alterations in Irradiated and Streptozotocin Treated Rats

International Nuclear Information System (INIS)

Mohamed, A.S.M.

2015-01-01

The objective of this study was to evaluate the role of GABA on some metabolic complications in STZ-treated, γ- irradiated and STZ-treated-γ-irradiated rats. Animals sacrificed 3 weeks after the different treatments showed that the intraperitoneal administration of STZ (60 mg/Kg) to male albino Sprague Dawley rats induced hyperglycemia and insulin deficiency (DM type 1). While whole body γ-irradiation with 6 Gy using Cs-137 source provoked hyperglycemia, hyperinsulinaemia and insulin resistance (DM type 2) and whole body γ-irradiation of STZ-treated rats induced hyperglycemia, insulin deficiency and insulin resistance. Dyslipidemia (elevated triglycerides, total cholesterol and LDL-C and decreased HDL-C) was recorded in STZ-treated, γ-irradiated and STZ-treated-γ-irradiated rats. Oxidative stress evidenced by significant decreases of SOD, catalase and GSH-Px activities and significant increases of MDA and AOPP was recorded in pancreas, liver and kidney tissues. Oxidative stress in pancreatic tissues was associated with damage of islets of Langerhans and significant decreases of GABA level and GAD activity. Oxidative stress in liver was accompanied by significant elevation of serum ALT and AST activities. Oxidative stress in kidney tissues was associated with significant increases of urea and creatinine levels. The administration of GABA daily via gavages (200 mg/Kg/day) during 3 weeks to STZ-treated, γ-irradiated and STZ-treated-γ-irradiated rats rectified insulin, glucose and lipid levels, reduced oxidative stress in pancreatic tissues accompanied by regenerating pancreatic islets of Langerhans and elevation of GABA level and GAD activity. GABA reduced also oxidative stress in liver and kidney tissues accompanied by lower serum ALT and AST activities and urea and creatinine levels

Effect of aluminum anodizing in phosphoric acid electrolyte on adhesion strength and thermal performance

Science.gov (United States)

Lee, Sulki; Kim, Donghyun; Kim, Yonghwan; Jung, Uoochang; Chung, Wonsub

2016-01-01

This study examined the adhesive bond strength and thermal performance of the anodized aluminum 6061 in phosphoric acid electrolyte to improve the adhesive bond strength and thermal performance for use in metal core printed circuit boards (MCPCB). The electrolyte temperature and applied voltage were altered to generate varied pore structures. The thickness, porosity and pore diameter of the anodized layer were measured. The pore morphologies were affected most by temperature, which was the driving force for ion transportation. The mechanism of adhesive bond was penetration of the epoxy into the pores. The optimal anodization conditions for maximum adhesive bond strength, 27 MPa, were 293 K and 100V. The maximum thermal conductivity of the epoxy-treated anodized layer was 1.6 W/m·K at 273 K. Compared with the epoxy-treated Al layer used for conventional MCPCBs, the epoxy-treated anodized layer showed advanced thermal performance due to a low difference of thermal resistance and high heat dissipation.

Comparison of LIFE-4 and TEMECH code predictions with TREAT transient test data

International Nuclear Information System (INIS)

Gneiting, B.C.; Bard, F.E.; Hunter, C.W.

1984-09-01

Transient tests in the TREAT reactor were performed on FFTF Reference design mixed-oxide fuel pins, most of which had received prior steady-state irradiation in the EBR-II reactor. These transient test results provide a data base for calibration and verification of fuel performance codes and for evaluation of processes that affect pin damage during transient events. This paper presents a comparison of the LIFE-4 and TEMECH fuel pin thermal/mechanical analysis codes with the results from 20 HEDL TREAT experiments, ten of which resulted in pin failure. Both the LIFE-4 and TEMECH codes provided an adequate representation of the thermal and mechanical data from the TREAT experiments. Also, a criterion for 50% probability of pin failure was developed for each code using an average cumulative damage fraction value calculated for the pins that failed. Both codes employ the two major cladding loading mechanisms of differential thermal expansion and central cavity pressurization which were demonstrated by the test results. However, a detailed evaluation of the code predictions shows that the two code systems weigh the loading mechanism differently to reach the same end points of the TREAT transient results

Analytical formulae in fractionated irradiation of normal tissue

International Nuclear Information System (INIS)

Kozubek, S.

1982-01-01

The new conception of the modeling of the cell tissue kinetics after fractionated irradiation is proposed. The formulae given earlier are compared with experimental data on various normal tissues and further adjustments are considered. The tissues are shown to exhibit several general patterns of behaviour. The repopulation, if it takes place, seems to start after some time, independently of fractionation in first approximation and can be treated as simple autogenesis. The results are compared with the commonly used NSD conception and the well-known Cohen cell tissue kinetic model

A Raman spectroscopic study of thermally treated glushinskite--the natural magnesium oxalate dihydrate.

Science.gov (United States)

Frost, Ray L; Adebajo, Moses; Weier, Matt L

2004-02-01

Raman spectroscopy has been used to study the thermal transformations of natural magnesium oxalate dihydrate known in mineralogy as glushinskite. The data obtained by Raman spectroscopy was supplemented with that of infrared emission spectroscopy. The vibrational spectroscopic data was complimented with high resolution thermogravimetric analysis combined with evolved gas mass spectrometry. TG-MS identified two mass loss steps at 146 and 397 degrees C. In the first mass loss step water is evolved only, in the second step carbon dioxide is evolved. The combination of Raman microscopy and a thermal stage clearly identifies the changes in the molecular structure with thermal treatment. Glushinskite is the dihydrate phase in the temperature range up to the pre-dehydration temperature of 146 degrees C. Above 397 degrees C, magnesium oxide is formed. Infrared emission spectroscopy shows that this mineral decomposes at around 400 degrees C. Changes in the position and intensity of the CO and CC stretching vibrations in the Raman spectra indicate the temperature range at which these phase changes occur.

Smart thermal patch for adaptive thermotherapy

KAUST Repository

Hussain, Muhammad Mustafa

2015-11-12

A smart thermal patch for adaptive thermotherapy is provided. In an embodiment, the patch can be a stretchable, non-polymeric, conductive thin film flexible and non-invasive body integrated mobile thermal heater with wireless control capabilities that can be used to provide adaptive thermotherapy. The patch can be geometrically and spatially tunable on various pain locations. Adaptability allows the amount of heating to be tuned based on the temperature of the treated portion.

Structural Design Optimization On Thermally Induced Vibration

International Nuclear Information System (INIS)

Gu, Yuanxian; Chen, Biaosong; Zhang, Hongwu; Zhao, Guozhong

2002-01-01

The numerical method of design optimization for structural thermally induced vibration is originally studied in this paper and implemented in application software JIFEX. The direct and adjoint methods of sensitivity analysis for thermal induced vibration coupled with both linear and nonlinear transient heat conduction is firstly proposed. Based on the finite element method, the structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat conduction. In the thermal analysis model, the nonlinear heat conduction considered is result from the radiation and temperature-dependent materials. The sensitivity analysis of transient linear and nonlinear heat conduction is performed with the precise time integration method. And then, the sensitivity analysis of structural transient dynamics is performed by the Newmark method. Both the direct method and the adjoint method are employed to derive the sensitivity equations of thermal vibration, and there are two adjoint vectors of structure and heat conduction respectively. The coupling effect of heat conduction on thermal vibration in the sensitivity analysis is particularly investigated. With coupling sensitivity analysis, the optimization model is constructed and solved by the sequential linear programming or sequential quadratic programming algorithm. The methods proposed have been implemented in the application software JIFEX of structural design optimization, and numerical examples are given to illustrate the methods and usage of structural design optimization on thermally induced vibration

Ultrasound elastographic imaging of thermal lesions and temperature profiles during radiofrequency ablation

Science.gov (United States)

Techavipoo, Udomchai

Manual palpation to sense variations in tissue stiffness for disease diagnosis has been regularly performed by clinicians for centuries. However, it is generally limited to large and superficial structures and the ability of the physician performing the palpation. Imaging of tissue stiffness or elastic properties via the aid of modern imaging such as ultrasound and magnetic resonance imaging, referred to as elastography, enhances the capability for disease diagnosis. In addition, elastography could be used for monitoring tissue response to minimally invasive ablative therapies, which are performed percutaneously to destruct tumors with minimum damage to surrounding tissue. Monitoring tissue temperature during ablation is another approach to estimate tissue damage. The ultimate goal of this dissertation is to improve the image quality of elastograms and temperature profiles for visualizing thermal lesions during and after ablative therapies. Elastographic imaging of thermal lesions is evaluated by comparison of sizes, shapes, and volumes with the results obtained using gross pathology. Semiautomated segmentation of lesion boundaries on elastograms is also developed. It provides comparable results to those with manual segmentation. Elastograms imaged during radiofrequency ablation in vitro show that the impact of gas bubbles during ablation on the ability to delineate the thermal lesion is small. Two novel methods to reduce noise artifacts in elastograms, and an accurate estimation of displacement vectors are proposed. The first method applies wavelet-denoising algorithms to the displacement estimates. The second method utilizes angular compounding of the elastograms generated using ultrasound signal frames acquired from different insonification angles. These angular frames are also utilized to estimate all tissue displacement vector components in response to a deformation. These enable the generation of normal and shear strain elastograms and Poisson's ratio

Radiosensitivity of soft tissue sarcomas

International Nuclear Information System (INIS)

Hirano, Toru; Iwasaki, Katsuro; Suzuki, Ryohei; Monzen, Yoshio; Hombo, Zenichiro

1989-01-01

The correlation between the effectiveness of radiation therapy and the histology of soft tissue sarcomas was investigated. Of 31 cases with a soft tissue sarcoma of an extremity treated by conservative surgery and postoperative radiation of 3,000-6,000 cGy, local recurrence occurred in 12; 5 out of 7 synovial sarcomas, 4 of 9 MFH, one of 8 liposarcomas, none of 4 rhabdomyosarcomas and 2 of 3 others. As for the histological subtyping, the 31 soft tissue sarcomas were divided into spindle cell, pleomorphic cell, myxoid and round cell type, and recurrence rates were 75%, 33.3%, 16.7% and 0%, respectively. From the remarkable difference in recurrent rate, it was suggested that round cell and myxoid type of soft tissue sarcomas showed a high radiosensitivity compared to the spindle cell type with low sensitivity. Clarifying the degree of radiosensitivity is helpful in deciding on the management of limb salvage in soft tissue sarcomas of an extremity. (author)

Initial screening of thermal desorption for soil remediation

International Nuclear Information System (INIS)

Yezzi, J.J. Jr.; Tafuri, A.N.; Rosenthal, S.; Troxler, W.L.

1994-01-01

Petroleum-contaminated soils--caused by spills, leaks, and accidental discharges--exist at many sites throughout the United States. Thermal desorption technologies which are increasingly being employed to treat these soils, have met soil cleanup criteria for a variety of petroleum products. Currently the United States Environmental Protection Agency is finalizing a technical report entitled Use of Thermal Desorption for Treating Petroleum-Contaminated Soils to assist remedial project managers, site owners, remediation contractors, and equipment vendors in evaluating the use of thermal desorption technologies for petroleum-contaminated soil applications. The report will present a three-level screening method to help a reader predict the success of applying thermal desorption at a specific site. The objective of screening level one is to determine the likelihood of success in a specific application of thermal desorption. It will take into account procedures for collecting and evaluating data on site characteristics, contaminant characteristics, soil characteristics, and regulatory requirements. This level will establish whether or not thermal desorption should be evaluated further for site remediation, whether treatment should occur on-site or off-site, and if on-site is a viable option, what system size will be most cost-effective. The scope of this paper addresses only screening level one which provides a preliminary assessment of the applicability of thermal desorption to a particular site. This topic encompasses worksheets that are an integral part of the ''user friendly'' screening process. Level one screening provides a foundation for the subsequent two levels which follow a similar ''user friendly'' worksheet approach to evaluating thermal desorption technologies and establishing costs for thermal desorption in an overall remediation project

Leaching from waste incineration bottom ashes treated in a rotary kiln

DEFF Research Database (Denmark)

Hyks, Jiri; Nesterov, Igor; Mogensen, Erhardt

2011-01-01

Leaching from municipal solid waste incineration bottom ash treated in a rotary kiln was quantified using a combination of lab-scale leaching experiments and geochemical modelling. Thermal treatment in the rotary kiln had no significant effect on the leaching of Al, Ba, Ca, Mg, Si, Sr, Zn, sulfate...... the thermal treatment. Overall, rotary kiln thermal treatment of bottom ashes can be recommended to reduce the leaching of Cu, Pb, Cl and DOC; however, increased leaching of Cr and Mo should be expected....

Thermal diffusivity imaging with the thermal lens microscope.

Science.gov (United States)

Dada, Oluwatosin O; Feist, Peter E; Dovichi, Norman J

2011-12-01

A coaxial thermal lens microscope was used to generate images based on both the absorbance and thermal diffusivity of histological samples. A pump beam was modulated at frequencies ranging from 50 kHz to 5 MHz using an acousto-optic modulator. The pump and a CW probe beam were combined with a dichroic mirror, directed into an inverted microscope, and focused onto the specimen. The change in the transmitted probe beam's center intensity was detected with a photodiode. The photodiode's signal and a reference signal from the modulator were sent to a high-speed lock-in amplifier. The in-phase and quadrature signals were recorded as a sample was translated through the focused beams and used to generate images based on the amplitude and phase of the lock-in amplifier's signal. The amplitude is related to the absorbance and the phase is related to the thermal diffusivity of the sample. Thin sections of stained liver and bone tissues were imaged; the contrast and signal-to-noise ratio of the phase image was highest at frequencies from 0.1-1 MHz and dropped at higher frequencies. The spatial resolution was 2.5 μm for both amplitude and phase images, limited by the pump beam spot size. © 2011 Optical Society of America

Cemented carbide cutting tool: Laser processing and thermal stress analysis

Energy Technology Data Exchange (ETDEWEB)

Yilbas, B.S. [Mechanical Engineering Department, KFUPM, Box 1913, Dhahran 31261 (Saudi Arabia)]. E-mail: bsyilbas@kfupm.edu.sa; Arif, A.F.M. [Mechanical Engineering Department, KFUPM, Box 1913, Dhahran 31261 (Saudi Arabia); Karatas, C. [Engineering Faculty, Hacettepe University, Ankara (Turkey); Ahsan, M. [Mechanical Engineering Department, KFUPM, Box 1913, Dhahran 31261 (Saudi Arabia)

2007-04-15

Laser treatment of cemented carbide tool surface consisting of W, C, TiC, TaC is examined and thermal stress developed due to temperature gradients in the laser treated region is predicted numerically. Temperature rise in the substrate material is computed numerically using the Fourier heating model. Experiment is carried out to treat the tool surfaces using a CO{sub 2} laser while SEM, XRD and EDS are carried out for morphological and structural characterization of the treated surface. Laser parameters were selected include the laser output power, duty cycle, assisting gas pressure, scanning speed, and nominal focus setting of the focusing lens. It is found that temperature gradient attains significantly high values below the surface particularly for titanium and tantalum carbides, which in turn, results in high thermal stress generation in this region. SEM examination of laser treated surface and its cross section reveals that crack initiation below the surface occurs and crack extends over the depth of the laser treated region.

Human adipose-derived stem cell spheroid treated with photobiomodulation irradiation accelerates tissue regeneration in mouse model of skin flap ischemia.

Science.gov (United States)

Park, In-Su; Chung, Phil-Sang; Ahn, Jin Chul; Leproux, Anais

2017-11-01

Skin flap grafting is a form of transplantation widely used in plastic surgery. However, ischemia/reperfusion injury is the main factor which reduces the survival rate of flaps following grafting. We investigated whether photobiomodulation (PBM) precondition prior to human adipose-derived stromal cell (hASC) spheroid (PBM-spheroid) transplantation improved skin tissue functional recovery by the stimulation of angiogenesis and tissue regeneration in skin flap of mice. The LED had an emission wavelength peaked at 660 ± 20 nm (6 J/cm 2 , 10 mW/cm 2 ). The expression of angiogenic growth factors in PBM-spheroid hASCs was much greater than that of not-PBM-treated spheroid or monolayer-cultured hASCs. From immunochemical staining analysis, the hASCs of PBM-spheroid were CD31 + , KDR + , and CD34 + , whereas monolayer-cultured hASCs were negative for these markers. To evaluate the therapeutic effect of hASC PBM-spheroid in vivo, PBS, monolayer-cultured hASCs, and not-PBM-spheroid were transplanted into a skin flap model. The animals were observed for 14 days. The PBM-spheroid hASCs transplanted into the skin flap ischemia differentiated into endothelial cells and remained differentiated. Transplantation of PBM-spheroid hASCs into the skin flap ischemia significantly elevated the density of vascular formations through angiogenic factors released by the skin flap ischemia and enhanced tissue regeneration at the lesion site. Consistent with these results, the transplantation of PBM-spheroid hASCs significantly improved functional recovery compared with PBS, monolayer-cultured hASCs, and not-PBM-spheroid treatment. These findings suggest that transplantation of PBM-spheroid hASCs may be an effective stem cell therapy for the treatment of skin flap ischemia.

Diode laser-induced tissue effects: in vitro tissue model study and in vivo evaluation of wound healing following non-contact application.

Science.gov (United States)

Havel, Miriam; Betz, Christian S; Leunig, Andreas; Sroka, Ronald

2014-08-01

The basic difference between the various common medical laser systems is the wavelength of the emitted light, leading to altered light-tissue interactions due to the optical parameters of the tissue. This study examines laser induced tissue effects in an in vitro tissue model using 1,470 nm diode laser compared to our standard practice for endonasal applications (940 nm diode laser) under standardised and reproducible conditions. Additionally, in vivo induced tissue effects following non-contact application with focus on mucosal healing were investigated in a controlled intra-individual design in patients treated for hypertrophy of nasal turbinate. A certified diode laser system emitting the light of λ = 1470 nm was evaluated with regards to its tissue effects (ablation, coagulation) in an in vitro setup on porcine liver and turkey muscle tissue model. To achieve comparable macroscopic tissue effects the laser fibres (600 µm core diameter) were fixed to a computer controlled stepper motor and the laser light was applied in a reproducible procedure under constant conditions. For the in vivo evaluation, 20 patients with nasal obstruction due to hyperplasia of inferior nasal turbinates were included in this prospective randomised double-blinded comparative trial. The endoscopic controlled endonasal application of λ = 1470 nm on the one and λ = 940 nm on the other side, both in 'non-contact' mode, was carried out as an outpatient procedure under local anaesthesia. The postoperative wound healing process (mucosal swelling, scab formation, bleeding, infection) was endoscopically documented and assessed by an independent physician. In the experimental setup, the 1,470 nm laser diode system proved to be efficient in inducing tissue effects in non-contact mode with a reduced energy factor of 5-10 for highly perfused liver tissue to 10-20 for muscle tissue as compared to the 940 nm diode laser system. In the in vivo evaluation scab formation

Non-Fourier thermal transport induced structural hierarchy and damage to collagen ultrastructure subjected to laser irradiation.

Science.gov (United States)

Sahoo, Nilamani; Narasimhan, Arunn; Dhar, Purbarun; Das, Sarit K

2018-05-01

Comprehending the mechanism of thermal transport through biological tissues is an important factor for optimal ablation of cancerous tissues and minimising collateral tissue damage. The present study reports detailed mapping of the rise in internal temperature within the tissue mimics due to NIR (1064 nm) laser irradiation, both for bare mimics and with gold nanostructures infused. Gold nanostructures such as mesoflowers and nanospheres have been synthesised and used as photothermal converters to enhance the temperature rise, resulting in achieving the desired degradation of malignant tissue in targeted region. Thermal history was observed experimentally and simulated considering non-Fourier dual phase lag (DPL) model incorporated Pennes bio-heat transfer equation using COMSOL Multiphysics software. The gross deviation in temperature i.e. rise from the classical Fourier model for bio-heat conduction suggests additional effects of temperature rise on the secondary structures and morphological and physico-chemical changes to the collagen ultrastructures building the tissue mass. The observed thermal denaturation in the collagen fibril morphologies have been explained based on the physico-chemical structure of collagen and its response to thermal radiation. The large shift in frequency of amides A and B is pronounced at a depth of maximum temperature rise compared with other positions in tissue phantom. Observations for change in band of amide I, amide II, and amide III are found to be responsible for damage to collagen ultra-structure. Variation in the concentration of gold nanostructures shows the potentiality of localised hyperthermia treatment subjected to NIR radiation through a proposed free radical mechanism.

Glucose-Treated Manganese Hexacyanoferrate for Sodium-Ion Secondary Battery

OpenAIRE

Moritomo, Yutaka; Goto, Kensuke; Shibata, Takayuki

2015-01-01

Manganese hexacyanoferrate (Mn-PBA) is a promising cathode material forsodium-ion secondary battery (SIB) with high average voltage (=3.4 V) against Na. Here,we find that the thermal decomposition of glucose modifies the surface state of Mn-PBA,without affecting the bulk crystal structure. The glucose treatment significantly improves therate properties of Mn-PBA in SIB. The critical discharge rate increases from 1 C (as-grown)to 15 C (glucose-treated). Our observation suggests that thermal tr...

Optimization of tissue physical parameters for accurate temperature estimation from finite-element simulation of radiofrequency ablation

International Nuclear Information System (INIS)

Subramanian, Swetha; Mast, T Douglas

2015-01-01

Computational finite element models are commonly used for the simulation of radiofrequency ablation (RFA) treatments. However, the accuracy of these simulations is limited by the lack of precise knowledge of tissue parameters. In this technical note, an inverse solver based on the unscented Kalman filter (UKF) is proposed to optimize values for specific heat, thermal conductivity, and electrical conductivity resulting in accurately simulated temperature elevations. A total of 15 RFA treatments were performed on ex vivo bovine liver tissue. For each RFA treatment, 15 finite-element simulations were performed using a set of deterministically chosen tissue parameters to estimate the mean and variance of the resulting tissue ablation. The UKF was implemented as an inverse solver to recover the specific heat, thermal conductivity, and electrical conductivity corresponding to the measured area of the ablated tissue region, as determined from gross tissue histology. These tissue parameters were then employed in the finite element model to simulate the position- and time-dependent tissue temperature. Results show good agreement between simulated and measured temperature. (note)

Optimization of tissue physical parameters for accurate temperature estimation from finite-element simulation of radiofrequency ablation.

Science.gov (United States)

Subramanian, Swetha; Mast, T Douglas

2015-10-07

Computational finite element models are commonly used for the simulation of radiofrequency ablation (RFA) treatments. However, the accuracy of these simulations is limited by the lack of precise knowledge of tissue parameters. In this technical note, an inverse solver based on the unscented Kalman filter (UKF) is proposed to optimize values for specific heat, thermal conductivity, and electrical conductivity resulting in accurately simulated temperature elevations. A total of 15 RFA treatments were performed on ex vivo bovine liver tissue. For each RFA treatment, 15 finite-element simulations were performed using a set of deterministically chosen tissue parameters to estimate the mean and variance of the resulting tissue ablation. The UKF was implemented as an inverse solver to recover the specific heat, thermal conductivity, and electrical conductivity corresponding to the measured area of the ablated tissue region, as determined from gross tissue histology. These tissue parameters were then employed in the finite element model to simulate the position- and time-dependent tissue temperature. Results show good agreement between simulated and measured temperature.

Effect of non-thermal air atmospheric pressure plasma jet treatment on gingival wound healing

International Nuclear Information System (INIS)

Lee, Jung-Hwan; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

2016-01-01

Non-thermal atmospheric pressure plasmas have been applied in the biomedical field for the improvement of various cellular activities. In dentistry, the healing of gingival soft tissue plays an important role in health and aesthetic outcomes. While the biomedical application of plasma has been thoroughly studied in dentistry, a detailed investigation of plasma-mediated human gingival fibroblast (HGF) migration for wound healing and its underlying biological mechanism is still pending. Therefore, the aim of this study is to apply a non-thermal air atmospheric pressure plasma jet (NTAAPPJ) to HGF to measure the migration and to reveal the underlying biological mechanisms involved in the migration. After the characterization of NTAAPPJ by optical emission spectroscopy, the adherent HGF was treated with NTAAPPJ or air with a different flow rate. Cell viability, lipid peroxidation, migration, intracellular reactive oxygen species (ROS), and the expression of migration-related genes (EGFR, PAK1, and MAPK3) were investigated. The level of statistical significance was set at 0.05. NTAAPPJ and air treatment with a flow rate of 250–1000 standard cubic centimetres per minute (sccm) for up to 30 s did not induce significant decreases in cell viability or membrane damage. A significant increase in the migration of mitomycin C-treated HGF was observed after 30 s of NTAAPPJ treatment compared to 30 s air-only treatment, which was induced by high levels of intracellular reactive oxygen species (ROS). An increase in migration-related gene expression and EGFR activation was observed following NTAAPPJ treatment in an air flow rate-dependent manner. This is the first report that NTAAPPJ treatment induces an increase in HGF migration without changing cell viability or causing membrane damage. HGF migration was related to an increase in intracellular ROS, changes in the expression of three of the migration-related genes (EGFR, PAK1, and MAPK1), and EGFR activation. Therefore

Mechanics of fresh, frozen-thawed and heated porcine liver tissue.

Science.gov (United States)

Wex, Cora; Stoll, Anke; Fröhlich, Marlen; Arndt, Susann; Lippert, Hans

2014-06-01

For a better understanding of the effects of thermally altered soft tissue, the biothermomechanics of these tissues need to be studied. Without the knowledge of the underlying physical processes and the parameters that can be controlled clinically, thermal treatment of cancerous hepatic tissue or the preservation of liver grafts are based primarily on trial and error. Thus, this study is concerned with the investigation of the influence of temperature on the rheological properties and the histological properties of porcine liver. Heating previously cooled porcine liver tissue above 40 °C leads to significant, irreversible stiffness changes observed in the amplitude sweep. The increase of the complex shear module of healthy porcine liver from room temperature to 70 °C is approximately 9-fold. Comparing the temperatures -20 °C and 20 °C, no significant difference of the mechanical properties was observed. Furthermore, there is a strong relation between the mechanical and histological properties of the porcine liver. Temperatures above 40 °C destroy the collagen matrix within the liver tissue. This results in the alteration of the biomechanical properties. The time-temperature superposition principle is applied to generate temperature-dependent shift factors that can be described by a two-part exponential function model with an inflection temperature of 45 °C. Tumor ablation techniques such as heating or freezing have a significant influence on the histology of liver tissue. However, only for temperatures above body temperature an influence on the mechanical properties of hepatic tissues was noticeable. Freezing up to -20 °C did not affect the liver mechanics.

Low thermal expansion glass ceramics

CERN Document Server

1995-01-01

This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

Zicam-induced damage to mouse and human nasal tissue.

Directory of Open Access Journals (Sweden)

Jae H Lim

Full Text Available Intranasal medications are used to treat various nasal disorders. However, their effects on olfaction remain unknown. Zicam (zinc gluconate; Matrixx Initiatives, Inc, a homeopathic substance marketed to alleviate cold symptoms, has been implicated in olfactory dysfunction. Here, we investigated Zicam and several common intranasal agents for their effects on olfactory function. Zicam was the only substance that showed significant cytotoxicity in both mouse and human nasal tissue. Specifically, Zicam-treated mice had disrupted sensitivity of olfactory sensory neurons to odorant stimulation and were unable to detect novel odorants in behavioral testing. These findings were long-term as no recovery of function was observed after two months. Finally, human nasal explants treated with Zicam displayed significantly elevated extracellular lactate dehydrogenase levels compared to saline-treated controls, suggesting severe necrosis that was confirmed on histology. Our results demonstrate that Zicam use could irreversibly damage mouse and human nasal tissue and may lead to significant smell dysfunction.

Analysis of thermal effects in endoscopic nanocarriers-based photodynamic therapy applied to esophageal diseases

Science.gov (United States)

Salas-García, I.; Fanjul-Vélez, F.; Ortega-Quijano, N.; Wilfert, O.; Hudcova, L.; Poliak, J.; Barcik, P.; Arce-Diego, J. L.

2014-02-01

In this work we propose a predictive model that allows the study of thermal effects produced when the optical radiation interacts with an esophageal or stomach disease with gold nanoparticles embedded. The model takes into account light distribution in the tumor tissue by means of a Monte Carlo method. Mie theory is used to obtain the gold nanoparticles optical properties and the thermal model employed is based on the bio-heat equation. The complete model was applied to two types of tumoral tissue (squamous cell carcinoma located in the esophagus and adenocarcinoma in the stomach) in order to study the thermal effects induced by the inclusion of gold nanoparticles.

Effects of microwave heating on the thermal states of biological tissues

African Journals Online (AJOL)

A mathematical analysis of microwave heating equations in one-dimensional multi-layer model has been discussed. Maxwell's equations and transient bioheat transfer equation were numerically calculated by using finite difference method to predict the effects of thermal physical properties on the transient temperature of ...

Influence trend of temperature distribution in skin tissue generated by different exposure dose pulse laser

Science.gov (United States)

Shan, Ning; Wang, Zhijing; Liu, Xia

2014-11-01

Laser is widely applied in military and medicine fields because of its excellent capability. In order to effectively defend excess damage by laser, the thermal processing theory of skin tissue generated by laser should be carried out. The heating rate and thermal damage area should be studied. The mathematics model of bio-tissue heat transfer that is irradiated by laser is analyzed. And boundary conditions of bio-tissue are discussed. Three layer FEM grid model of bio-tissue is established. The temperature rising inducing by pulse laser in the tissue is modeled numerically by adopting ANSYS software. The changing trend of temperature in the tissue is imitated and studied under the conditions of different exposure dose pulse laser. The results show that temperature rising in the tissue depends on the parameters of pulse laser largely. In the same conditions, the pulse width of laser is smaller and its instant power is higher. And temperature rising effect in the tissue is very clear. On the contrary, temperature rising effect in the tissue is lower. The cooling time inducing by temperature rising effect in the tissue is longer along with pulse separation of laser is bigger. And the temperature difference is bigger in the pulse period.

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

Science.gov (United States)

Picolloto, A. M.; Mariucci, V. V. G.; Szpak, W.; Medina, A. N.; Baesso, M. L.; Astrath, N. G. C.; Astrath, F. B. G.; Santos, A. D.; Moraes, J. C. S.; Bento, A. C.

2013-11-01

The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (˜7 min) and with similar thermal expansion (˜12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10-3 cm2/s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s0.5/cm2 K and volume heat capacity (5.2 ± 0.7) J/cm3 K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water).

Effect of thermal-treatment sequence on sound absorbing and mechanical properties of porous sound-absorbing/thermal-insulating composites

Directory of Open Access Journals (Sweden)

Huang Chen-Hung

2016-01-01

Full Text Available Due to recent rapid commercial and industrial development, mechanical equipment is supplemented massively in the factory and thus mechanical operation causes noise which distresses living at home. In livelihood, neighborhood, transportation equipment, jobsite construction noises impact on quality of life not only factory noise. This study aims to preparation technique and property evaluation of porous sound-absorbing/thermal-insulating composites. Hollow three-dimensional crimp PET fibers blended with low-melting PET fibers were fabricated into hollow PET/low-melting PET nonwoven after opening, blending, carding, lapping and needle-bonding process. Then, hollow PET/low-melting PET nonwovens were laminated into sound-absorbing/thermal-insulating composites by changing sequence of needle-bonding and thermal-treatment. The optimal thermal-treated sequence was found by tensile strength, tearing strength, sound-absorbing coefficient and thermal conductivity coefficient tests of porous composites.

CO II laser free-form processing of hard tissue

Science.gov (United States)

Werner, Martin; Klasing, Manfred; Ivanenko, Mikhail; Harbecke, Daniela; Steigerwald, Hendrik; Hering, Peter

2007-07-01

Drilling and surface processing of bone and tooth tissue belongs to standard medical procedures (bores and embeddings for implants, trepanation etc.). Small circular bores can be generally quickly produced with mechanical drills. However problems arise at angled drilling, the need to execute drilling procedures without damaging of sensitive soft tissue structures underneath the bone or the attempt to mill small non-circular cavities in hard tissue with high precision. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The processing of bone is done with a CO II laser (10.6 μm) with pulse durations of 50 - 100 μs, combined with a PC-controlled fast galvanic laser beam scanner and a fine water-spray, which helps keeping the ablation process effective and without thermal side-effects. Laser "milling" of non-circular cavities with 1 - 4 mm width and about 10 mm depth can be especially interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser processing of these cavities without thermal damage and with minimised tapering. It included the exploration of different filling patterns (concentric rings, crosshatch, parallel lines, etc.), definition of maximal pulse duration, repetition rate and laser power, and optimal water spray position. The optimised results give evidence for the applicability of pulsed CO II lasers for biologically tolerable effective processing of deep cavities in hard tissue.

Thermal Conversion of Pine Wood Char to Carbon Nanomaterials in the Presence of Iron Nanoparticles

Science.gov (United States)

Sung Phil Mun; Zhiyong Cai; Fumiya Watanabe; Umesh P. Agarwal; Jilei. Zhang

2012-01-01

Southern yellow pine (Pinus taeda) wood char powder was thermally treated at 1,000:C in the presence of a 25-nm-size Fe nanoparticle catalyst. The thermally treated carbon materials were analyzed by Raman spectroscopy and high-resolution transmission electron microscopy. Well-aligned graphitic carbon structures with 15 to 17 layers on...

Control of thermal therapies with moving power deposition field

International Nuclear Information System (INIS)

Arora, Dhiraj; Minor, Mark A; Skliar, Mikhail; Roemer, Robert B

2006-01-01

A thermal therapy feedback control approach to control thermal dose using a moving power deposition field is developed and evaluated using simulations. A normal tissue safety objective is incorporated in the controller design by imposing constraints on temperature elevations at selected normal tissue locations. The proposed control technique consists of two stages. The first stage uses a model-based sliding mode controller that dynamically generates an 'ideal' power deposition profile which is generally unrealizable with available heating modalities. Subsequently, in order to approximately realize this spatially distributed idealized power deposition, a constrained quadratic optimizer is implemented to compute intensities and dwell times for a set of pre-selected power deposition fields created by a scanned focused transducer. The dwell times for various power deposition profiles are dynamically generated online as opposed to the commonly employed a priori-decided heating strategies. Dynamic intensity and trajectory generation safeguards the treatment outcome against modelling uncertainties and unknown disturbances. The controller is designed to enforce simultaneous activation of multiple normal tissue temperature constraints by rapidly switching between various power deposition profiles. The hypothesis behind the controller design is that the simultaneous activation of multiple constraints substantially reduces treatment time without compromising normal tissue safety. The controller performance and robustness with respect to parameter uncertainties is evaluated using simulations. The results demonstrate that the proposed controller can successfully deliver the desired thermal dose to the target while maintaining the temperatures at the user-specified normal tissue locations at or below the maximum allowable values. Although demonstrated for the case of a scanned focused ultrasound transducer, the developed approach can be extended to other heating modalities with

Thermal degradation of ethanolic biodiesel: Physicochemical and thermal properties evaluation

International Nuclear Information System (INIS)

Silva, Wellington Costa; Castro, Maria Priscila Pessanha; Perez, Victor Haber; Machado, Francisco A.; Mota, Leonardo; Sthel, Marcelo Silva

2016-01-01

The aim of this paper was to study the thermal degradation of soybean biodiesel attained by ethanolic route. The soybean biodiesel samples were subjected to heating treatment at 150 °C for 24 h in a closed oven under controlled atmosphere. During the experiments, samples were withdrawn at intervals of 3, 6, 9, 12, 15 and 24 h for physicochemical and thermophysical properties analysis. The biodiesel degradation was validated by Thermogravimetric analysis since their profiles for control and treated biodiesel were different. Also, "1H NMR confirmed this result due to a significant reduction at the signals related to the "1H located near to the double bonds in the unsaturated ethyl esters in agreement with an iodine index reduction and viscosity increase observed during degradation. Nevertheless, degraded biodiesel, under study conditions, preserved its thermophysical properties. These results may be relevant to qualify the produced biodiesel quality and collect physicochemical and thermophysical data important for applications in combustion studies including project of fuel injection systems. - Highlights: • Soybean biodiesel from ethanolic route was subjected to thermal degradation to verify its stability. • Thermal degradation of biodiesel was correlated with physicochemical properties. • Thermal effusivity, diffusivity and conductivity were estimate by photothermal techniques.

Always cleave up your mess: targeting collagen degradation to treat tissue fibrosis

Science.gov (United States)

McKleroy, William; Lee, Ting-Hein

2013-01-01

Pulmonary fibrosis is a vexing clinical problem with no proven therapeutic options. In the normal lung there is continuous collagen synthesis and collagen degradation, and these two processes are precisely balanced to maintain normal tissue architecture. With lung injury there is an increase in the rate of both collagen production and collagen degradation. The increase in collagen degradation is critical in preventing the formation of permanent scar tissue each time the lung is exposed to injury. In pulmonary fibrosis, collagen degradation does not keep pace with collagen production, resulting in extracellular accumulation of fibrillar collagen. Collagen degradation occurs through both extracellular and intracellular pathways. The extracellular pathway involves cleavage of collagen fibrils by proteolytic enzyme including the metalloproteinases. The less-well-described intracellular pathway involves binding and uptake of collagen fragments by fibroblasts and macrophages for lysosomal degradation. The relationship between these two pathways and their relevance to the development of fibrosis is complex. Fibrosis in the lung, liver, and skin has been associated with an impaired degradative environment. Much of the current scientific effort in fibrosis is focused on understanding the pathways that regulate increased collagen production. However, recent reports suggest an important role for collagen turnover and degradation in regulating the severity of tissue fibrosis. The objective of this review is to evaluate the roles of the extracellular and intracellular collagen degradation pathways in the development of fibrosis and to examine whether pulmonary fibrosis can be viewed as a disease of impaired matrix degradation rather than a disease of increased matrix production. PMID:23564511

Radiotherapy in patients with connective tissue diseases.

Science.gov (United States)

Giaj-Levra, Niccolò; Sciascia, Savino; Fiorentino, Alba; Fersino, Sergio; Mazzola, Rosario; Ricchetti, Francesco; Roccatello, Dario; Alongi, Filippo

2016-03-01

The decision to offer radiotherapy in patients with connective tissue diseases continues to be challenging. Radiotherapy might trigger the onset of connective tissue diseases by increasing the expression of self-antigens, diminishing regulatory T-cell activity, and activating effectors of innate immunity (dendritic cells) through Toll-like receptor-dependent mechanisms, all of which could potentially lead to breaks of immune tolerance. This potential risk has raised some debate among radiation oncologists about whether patients with connective tissue diseases can tolerate radiation as well as people without connective tissue diseases. Because the number of patients with cancer and connective tissue diseases needing radiotherapy will probably increase due to improvements in medical treatment and longer life expectancy, the issue of interactions between radiotherapy and connective tissue diseases needs to be clearer. In this Review, we discuss available data and evidence for patients with connective tissue diseases treated with radiotherapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Studies on thermal degradation and termite resistant properties of chemically modified wood

Energy Technology Data Exchange (ETDEWEB)

Deka, M.; Saikia, C.N. [Council for Scientific and Industrial Research (CSIR), Regional Research Laboratory, Jorhat (India); Baruah, K.K. [Assam Agricultural University, Jorhat (India)

2002-09-01

A series of experiments were carried out to examine the resistant capacity of a chemically treated hard wood, Anthocephalus cadamba (Roxb) Miq. to thermal and termite degradation. The treatment with thermosetting resins viz. urea formaldehyde (UF), melamine formaldehyde (MF) and phenol formaldehyde (PF) at 31-33 levels of weight percent gain (WPG) increased the strength property i.e. modulus of rupture (MOR) by 7.50-21.02% and stiffness i.e. modulus of elasticity (MOE) by 9.50-12.18% over the untreated one with no remarkable effect on specific gravity. The treated samples were found resistant to termite attack, while the untreated one was badly damaged by termites on 12 months' exposure to a termite colony. The thermal degradations of untreated and treated wood samples were studied using thermogravimetric (TGA) and differential thermogravimetric (DTG) techniques at heating rates 20 and 30 {sup o}Cmin{sup -1} in temperature range 30-650{sup o}C. The treated wood was found to be thermally more stable than the untreated one. (author)

Dynamics of hydrated mucopolysaccharides in cartilaginous tissues treated by laser radiation

Science.gov (United States)

Omelchenko, Alexander I.; Sobol, Emil N.; Ignatieva, Natalia Y.; Lunin, Valerii V.; Jumel, Kornelia; Harding, Stephen E.; Jones, Nicholas

2001-05-01

Dynamic mechanical properties of hydrated mucopolysaccharides have been studied in heated solutions by means of molecular hydrodynamic and acoustic techniques. These experiments model the thermal condition used for laser reshaping of cartilage. It has been shown that elastic modulus and internal friction depends on concentration of chondroitine sulphate in the solution and temperature. Maximum of internal friction was revealed at about 40 degree(s)C that corresponds to temperature of breakdown of hydrophobic bonds. Temperature dependence of internal friction manifests structural changes in polysaccharides molecules under laser heating.

Transient Diabetes Insipidus Following Thermal Burn; A Case Report and Literature Review.

Science.gov (United States)

Dash, Suvashis; Ghosh, Shibajyoti

2017-10-01

Diabetes insipidus is a disease charaterised by increased urine production and thrist. Neurogenic diabetes insipidus following head trauma,autoimmune disease and infection is quite common but diabetes insipidus following thermal burn injury is a rare complication.We should know about this complication as its management need a comprehensive approach for satisfactory outcome. Thermal burn can cause different complications in early post burn period like electrolyte imbalance, dehydration, acute renal failure, but diabetes insipidus is a very rare and unusual complication that may come across in thermal burn. We should be aware about this condition to prevent and treat mortality and morbidity in burn patients. We have reported a case of transient diabetes insipidus in a patient of thermal burn in early post burn period. Patient was treated accordingly, leading to complete recovery.

A Tissue Propagation Model for Validating Close-Proximity Biomedical Radiometer Measurements

Science.gov (United States)

Bonds, Q.; Herzig, P.; Weller, T.

2016-01-01

The propagation of thermally-generated electromagnetic emissions through stratified human tissue is studied herein using a non-coherent mathematical model. The model is developed to complement subsurface body temperature measurements performed using a close proximity microwave radiometer. The model takes into account losses and reflections as thermal emissions propagate through the body, before being emitted at the skin surface. The derivation is presented in four stages and applied to the human core phantom, a physical representation of a stomach volume of skin, muscle, and blood-fatty tissue. A drop in core body temperature is simulated via the human core phantom and the response of the propagation model is correlated to the radiometric measurement. The results are comparable, with differences on the order of 1.5 - 3%. Hence the plausibility of core body temperature extraction via close proximity radiometry is demonstrated, given that the electromagnetic characteristics of the stratified tissue layers are known.

Tissue-Engineered Skin Substitute Enhances Wound Healing after Radiation Therapy.

Science.gov (United States)

Busra, Mohd Fauzi bin Mh; Chowdhury, Shiplu Roy; bin Ismail, Fuad; bin Saim, Aminuddin; Idrus, Ruszymah Bt Hj

2016-03-01

When given in conjunction with surgery for treating cancer, radiation therapy may result in impaired wound healing, which, in turn, could cause skin ulcers. In this study, bilayer and monolayer autologous skin substitutes were used to treat an irradiated wound. A single dose of 30 Gy of linear electron beam radiation was applied to the hind limb of nude mice before creating the skin lesion (area of 78.6 mm). Monolayer tissue-engineered skin substitutes (MTESSs) were prepared by entrapping cultured keratinocytes in fibrin matrix, and bilayer tissue-engineered skin substitutes (BTESSs) were prepared by entrapping keratinocytes and fibroblasts in separate layers. Bilayer tissue-engineered skin substitute and MTESS were implanted to the wound area. Gross appearance and wound area were analyzed to evaluate wound healing efficiency. Skin regeneration and morphological appearance were observed via histological and electron microscopy. Protein expressions of transforming growth factor β1 (TGF-β1), platelet-derived growth factor BB (PDGF-BB), and vascular endothelial growth factor (VEGF) in skin regeneration were evaluated by immunohistochemistry (IHC). Macroscopic observation revealed that at day 13, treatments with BTESS completely healed the irradiated wound, whereas wound sizes of 1.1 ± 0.05 and 6.8 ± 0.14 mm were measured in the MTESS-treated and untreated control groups, respectively. Hematoxylin-eosin (H&E) analysis showed formation of compact and organized epidermal and dermal layers in the BTESS-treated group, as compared with MTESS-treated and untreated control groups. Ultrastructural analysis indicates maturation of skin in BTESS-treated wound evidenced by formation of intermediate filament bundles in the dermal layer and low intercellular space in the epidermal layer. Expressions of TGF-β1, PDGF-BB, and VEGF were also higher in BTESS-treated wounds, compared with MTESS-treated wounds. These results indicate that BTESS is the preferred treatment for

Soy Protein Scaffold Biomaterials for Tissue Engineering and Regenerative Medicine

Science.gov (United States)

Chien, Karen B.

Developing functional biomaterials using highly processable materials with tailorable physical and bioactive properties is an ongoing challenge in tissue engineering. Soy protein is an abundant, natural resource with potential use for regenerative medicine applications. Preliminary studies show that soy protein can be physically modified and fabricated into various biocompatible constructs. However, optimized soy protein structures for tissue regeneration (i.e. 3D porous scaffolds) have not yet been designed. Furthermore, little work has established the in vivo biocompatibility of implanted soy protein and the benefit of using soy over other proteins including FDA-approved bovine collagen. In this work, freeze-drying and 3D printing fabrication processes were developed using commercially available soy protein to create porous scaffolds that improve cell growth and infiltration compared to other soy biomaterials previously reported. Characterization of scaffold structure, porosity, and mechanical/degradation properties was performed. In addition, the behavior of human mesenchymal stem cells seeded on various designed soy scaffolds was analyzed. Biological characterization of the cell-seeded scaffolds was performed to assess feasibility for use in liver tissue regeneration. The acute and humoral response of soy scaffolds implanted in an in vivo mouse subcutaneous model was also investigated. All fabricated soy scaffolds were modified using thermal, chemical, and enzymatic crosslinking to change properties and cell growth behavior. 3D printing allowed for control of scaffold pore size and geometry. Scaffold structure, porosity, and degradation rate significantly altered the in vivo response. Freeze-dried soy scaffolds had similar biocompatibility as freeze-dried collagen scaffolds of the same protein content. However, the soy scaffolds degraded at a much faster rate, minimizing immunogenicity. Interestingly, subcutaneously implanted soy scaffolds affected blood

Development of a test device to characterize thermal protective performance of fabrics against hot steam and thermal radiation

International Nuclear Information System (INIS)

Su, Yun; Li, Jun

2016-01-01

Steam burns severely threaten the life of firefighters in the course of their fire-ground activities. The aim of this paper was to characterize thermal protective performance of flame-retardant fabrics exposed to hot steam and low-level thermal radiation. An improved testing apparatus based on ASTM F2731-11 was developed in order to simulate the routine fire-ground conditions by controlling steam pressure, flow rate and temperature of steam box. The thermal protective performance of single-layer and multi-layer fabric system with/without an air gap was studied based on the calibrated tester. It was indicated that the new testing apparatus effectively evaluated thermal properties of fabric in hot steam and thermal radiation. Hot steam significantly exacerbated the skin burn injuries while the condensed water on the skin’s surface contributed to cool down the skin tissues during the cooling. Also, the absorbed thermal energy during the exposure and the cooling was mainly determined by the fabric’s configuration, the air gap size, the exposure time and the existence of hot steam. The research provides a effective method to characterize the thermal protection of fabric in complex conditions, which will help in optimization of thermal protection performance of clothing and reduction of steam burn. (paper)

Implantable oxygen microelectrode suitable for medium-term investigations of post-surgical tissue hypoxia and changes in tumor tissue oxygenation produced by radiotherapy

International Nuclear Information System (INIS)

Burke, T.R.; Johnson, R.J.; Krishnamsetty, C.B.; Sako, K.; Karakousis, C.; Wojtas, F.

1980-01-01

Teflon-covered platinum oxygen probes were used to monitor tissue oxygen levels in post-surgical cancer patients and those treated with radiotherapy. Progressive wound healing was usually accompanied by a decrease in tissue pO2. Radiotherapy produced a slight increase in pO2 while hyperthermia effected a significant increase in the oxygen level during 100% oxygen breathing

Pulsed Tm:YAG laser ablation of knee joint tissues

Science.gov (United States)

Shi, Wei-Qiang; Vari, Sandor G.; Duffy, J. T.; Miller, J. M.; Weiss, Andrew B.; Fishbein, Michael C.; Grundfest, Warren S.

1992-06-01

We investigated the effect of a free-running 2.01 micron pulsed Tm:YAG laser on bovine knee joint tissues. Ablation rates of fresh fibrocartilage, hyaline cartilage, and bone were measured in saline as a function of laser fluence (160 - 640 J/cm2) and fiber core size (400 and 600 microns). All tissues could be effectively ablated and the ablation rate increased linearly with the increasing fluence. Use of fibers of different core sizes, while maintaining constant energy fluence, did not result in significant difference in ablation rate. Histology analyses of the ablated tissue samples reveal average Tm:YAG radiation induced thermal damage (denatunalization) zones ranging between 130 and 540 microns, depending on the laser parameters and the tissue type.

Osmotic dehydration of some agro-food tissue pre-treated by pulsed electric field: Impact of impeller’s Reynolds number on mass transfer and color

Directory of Open Access Journals (Sweden)

E. Amami

2014-01-01

Full Text Available Tissues of apple, carrot and banana were pre-treated by pulsed electric field (PEF and subsequently osmotically dehydrated in an agitated flask at ambient temperature using a 65% sucrose solution as osmotic medium. The effect of stirring intensity was investigated through water loss (WL and solid gain (SG. Changes in product color were also considered to analyze the impact of the treatment. The impeller’s Reynolds number was used to quantify the agitation. The Reynolds number remained inferior to 300 thus displaying laminar flow regime. Water loss (WL and solid gain (SG increase with the increase of Reynolds number. Mass transfer in osmotic dehydration of all three test particles has been studied on the basis of a two-exponential kinetic model. Then, mass transfer coefficients were related to the agitation intensity. This paper shows that the proposed empirical model is able to describe mass transfer phenomena in osmotic dehydration of these tissues. It is also shown that a higher agitation intensity improves both the kinetics of water loss and solid gain.

Effect of heat stress on contractility of tissue-engineered artificial skeletal muscle.

Science.gov (United States)

Takagi, Shunya; Nakamura, Tomohiro; Fujisato, Toshia

2018-01-23

The effects of heat stress on tissue like skeletal muscle have been widely studied. However, the mechanism responsible for the effect of heat stress is still unclear. A useful experimental tissue model is necessary because muscle function in cell culture may differ from native muscle and measuring its contractility is difficult. We previously reported three-dimensional tissue-engineered artificial skeletal muscle (TEM) that can be easily set in a measurement apparatus for quantitative evaluation of contractility. We have now applied TEM to the investigation of heat stress. We analyzed contractility immediately after thermal exposure at 39 °C for 24 or 48 h to evaluate the acute effects and after thermal exposure followed by normal culture to evaluate the aftereffects. Peak twitch contractile force and time-to-peak twitch were used as contractile parameters. Heat stress increased the TCF in the early stage (1 week) after normal culture; the TCF decreased temporarily in the middle to late stages (2-3 weeks). These results suggest that heat stress may affect both myoblast fusion and myotube differentiation in the early stage of TEM culture, but not myotube maturation in the late stage. The TCF increase rate with thermal exposure was significantly higher than that without thermal exposure. Although detailed analysis at the molecular level is necessary for further investigation, our artificial skeletal muscle may be a promising tool for heat stress investigation.

Necrotising soft tissue infection following mastectomy

Directory of Open Access Journals (Sweden)

Jackson P

2010-03-01

Full Text Available Necrotising fasciitis is a rare but rapidly progressive soft tissue disease which can lead to extensive necrosis, systemic sepsis and death. Including this case, only 7 other cases have been reported in the world literature with only 2 others affecting the patient post mastectomy.This 59 year old Caucasian lady presented with severe soft tissue infection soon after mastectomy, which was successfully treated with a combination of debridement, triangulation, VAC© dressing and skin grafting.Necrotising soft tissue infections following mastectomy are rapidly progressive and potentially extremely serious. It is essential that a high index of clinical suspicion is maintained together with prompt aggressive treatment in a multidisciplinary environment to prevent worsening physical and psychological sequelae.

Radiogenomics: predicting clinical normal tissue radiosensitivity

DEFF Research Database (Denmark)

Alsner, Jan

2006-01-01

Studies on the genetic basis of normal tissue radiosensitivity, or  'radiogenomics', aims at predicting clinical radiosensitivity and optimize treatment from individual genetic profiles. Several studies have now reported links between variations in certain genes related to the biological response...... to radiation injury and risk of normal tissue morbidity in cancer patients treated with radiotherapy. However, after these initial association studies including few genes, we are still far from being able to predict clinical radiosensitivity on an individual level. Recent data from our own studies on risk...

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

Energy Technology Data Exchange (ETDEWEB)

Picolloto, A. M.; Mariucci, V. V. G.; Szpak, W.; Medina, A. N.; Baesso, M. L.; Astrath, N. G. C.; Astrath, F. B. G.; Bento, A. C., E-mail: acbento@uem.br [Departamento de Física, Grupo de Espectroscopia Fotoacústica e Fototérmica, Universidade Estadual de Maringá – UEM, Av. Colombo 5790, 87020-900 Maringá, Paraná (Brazil); Santos, A. D.; Moraes, J. C. S. [Departamento de Física e Química, Universidade Estadual Paulista Júlio de Mesquita Filho – UNESP, Av. Brasil 56, 15385-000 Ilha Solteira, SP (Brazil)

2013-11-21

The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (∼7 min) and with similar thermal expansion (∼12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10{sup −3} cm{sup 2}/s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s{sup 0.5}/cm{sup 2} K and volume heat capacity (5.2 ± 0.7) J/cm{sup 3} K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water)

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

International Nuclear Information System (INIS)

Picolloto, A. M.; Mariucci, V. V. G.; Szpak, W.; Medina, A. N.; Baesso, M. L.; Astrath, N. G. C.; Astrath, F. B. G.; Bento, A. C.; Santos, A. D.; Moraes, J. C. S.

2013-01-01

The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (∼7 min) and with similar thermal expansion (∼12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10 −3 cm 2 /s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s 0.5 /cm 2 K and volume heat capacity (5.2 ± 0.7) J/cm 3 K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water)

Temperature dependence of the shear modulus of soft tissues assessed by ultrasound

International Nuclear Information System (INIS)

Sapin-de Brosses, E; Gennisson, J-L; Pernot, M; Fink, M; Tanter, M

2010-01-01

Soft tissue stiffness was shown to significantly change after thermal ablation. To better understand this phenomenon, the study aims (1) to quantify and explain the temperature dependence of soft tissue stiffness for different organs, (2) to investigate the potential relationship between stiffness changes and thermal dose and (3) to study the reversibility or irreversibility of stiffness changes. Ex vivo bovine liver and muscle samples (N = 3 and N = 20, respectively) were slowly heated and cooled down into a thermally controlled saline bath. Temperatures were assessed by thermocouples. Sample stiffness (shear modulus) was provided by the quantitative supersonic shear imaging technique. Changes in liver stiffness are observed only after 45 deg. C. In contrast, between 25 deg. C and 65 deg. C, muscle stiffness varies in four successive steps that are consistent with the thermally induced proteins denaturation reported in the literature. After a 6 h long heating and cooling process, the final muscle stiffness can be either smaller or bigger than the initial one, depending on the stiffness at the end of the heating. Another important result is that stiffness changes are linked to thermal dose. Given the high sensitivity of ultrasound to protein denaturation, this study gives promising prospects for the development of ultrasound-guided HIFU systems.

Temperature dependence of the shear modulus of soft tissues assessed by ultrasound

Energy Technology Data Exchange (ETDEWEB)

Sapin-de Brosses, E; Gennisson, J-L; Pernot, M; Fink, M; Tanter, M [Langevin Institute (CNRS UMR 7587), INSERM ERL U979, ESPCI ParisTech, 10 rue Vauquelin, 75 005 Paris (France)], E-mail: emilie.sapin@espci.fr

2010-03-21

Soft tissue stiffness was shown to significantly change after thermal ablation. To better understand this phenomenon, the study aims (1) to quantify and explain the temperature dependence of soft tissue stiffness for different organs, (2) to investigate the potential relationship between stiffness changes and thermal dose and (3) to study the reversibility or irreversibility of stiffness changes. Ex vivo bovine liver and muscle samples (N = 3 and N = 20, respectively) were slowly heated and cooled down into a thermally controlled saline bath. Temperatures were assessed by thermocouples. Sample stiffness (shear modulus) was provided by the quantitative supersonic shear imaging technique. Changes in liver stiffness are observed only after 45 deg. C. In contrast, between 25 deg. C and 65 deg. C, muscle stiffness varies in four successive steps that are consistent with the thermally induced proteins denaturation reported in the literature. After a 6 h long heating and cooling process, the final muscle stiffness can be either smaller or bigger than the initial one, depending on the stiffness at the end of the heating. Another important result is that stiffness changes are linked to thermal dose. Given the high sensitivity of ultrasound to protein denaturation, this study gives promising prospects for the development of ultrasound-guided HIFU systems.

Influences of thermal decontamination on mercury removal, soil properties, and repartitioning of coexisting heavy metals.

Science.gov (United States)

Huang, Yu-Tuan; Hseu, Zeng-Yei; Hsi, Hsing-Cheng

2011-08-01

Thermal treatment is a useful tool to remove Hg from contaminated soils. However, thermal treatment may greatly alter the soil properties and cause the coexisting contaminants, especially trace metals, to transform and repartition. The metal repartitioning may increase the difficulty in the subsequent process of a treatment train approach. In this study, three Hg-contaminated soils were thermally treated to evaluate the effects of treating temperature and duration on Hg removal. Thermogravimetric analysis was performed to project the suitable heating parameters for subsequent bench-scale fixed-bed operation. Results showed that thermal decontamination at temperature>400°C successfully lowered the Hg content tosoil particle size was less significant, even when the soils were thermally treated to 550°C. Soil clay minerals such as kaolinite were shown to be decomposed. Aggregates were observed on the surface of soil particles after the treatment. The heavy metals tended to transform into acid-extractable, organic-matter bound, and residual forms from the Fe/Mn oxide bound form. These results suggest that thermal treatment may markedly influence the effectiveness of subsequent decontamination methods, such as acid washing or solvent extraction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Tissue Engineering for Human Urethral Reconstruction : Systematic Review of Recent Literature

NARCIS (Netherlands)

de Kemp, Vincent; de Graaf, Petra; Fledderus, Joost O.; Bosch, JLHR; de Kort, Laetitia

2015-01-01

Background Techniques to treat urethral stricture and hypospadias are restricted, as substitution of the unhealthy urethra with tissue from other origins (skin, bladder or buccal mucosa) has some limitations. Therefore, alternative sources of tissue for use in urethral reconstructions are

The thermal properties of a carbon nanotube-enriched epoxy: Thermal conductivity, curing, and degradation kinetics

KAUST Repository

Ventura, Isaac Aguilar

2013-05-31

Multiwalled carbon nanotube-enriched epoxy polymers were prepared by solvent evaporation based on a commercially available epoxy system and functionalized multiwalled carbon nanotubes (COOH-MWCNTs). Three weight ratio configurations (0.05, 0.5, and 1.0 wt %) of COOH-MWCNTs were considered and compared with neat epoxy and ethanol-treated epoxy to investigate the effects of nano enrichment and processing. Here, the thermal properties of the epoxy polymers, including curing kinetics, thermal conductivity, and degradation kinetics were studied. Introducing the MWCNTs increased the curing activation energy as revealed by differential scanning calorimetry. The final thermal conductivity of the 0.5 and 1.0 wt % MWCNT-enriched epoxy samples measured by laser flash technique increased by up to 15% compared with the neat material. The activation energy of the degradation process, investigated by thermogravimetric analysis, was found to increase with increasing CNT content, suggesting that the addition of MWCNTs improved the thermal stability of the epoxy polymers. © 2013 Wiley Periodicals, Inc.

Tissue Engineering Bionanocomposites Based on Poly(propylene fumarate

Directory of Open Access Journals (Sweden)

Ana M. Diez-Pascual

2017-06-01

Full Text Available Poly(propylene fumarate (PPF is a linear and unsaturated copolyester based on fumaric acid that has been widely investigated for tissue engineering applications in recent years due to its tailorable mechanical performance, adjustable biodegradability and exceptional biocompatibility. In order to improve its mechanical properties and spread its range of practical applications, novel approaches need to be developed such as the incorporation of fillers or polymer blending. Thus, PPF-based bionanocomposites reinforced with different amounts of single-walled carbon nanotubes (SWCNT, multi-walled carbon nanotubes (MWCNT, graphene oxide nanoribbons (GONR, graphite oxide nanoplatelets (GONP, polyethylene glycol-functionalized graphene oxide (PEG-GO, polyethylene glycol-grafted boron nitride nanotubes (PEG-g-BNNTs and hydroxyapatite (HA nanoparticles were synthesized via sonication and thermal curing, and their morphology, biodegradability, cytotoxicity, thermal, rheological, mechanical and antibacterial properties were investigated. An increase in the level of hydrophilicity, biodegradation rate, stiffness and strength was found upon increasing nanofiller loading. The nanocomposites retained enough rigidity and strength under physiological conditions to provide effective support for bone tissue formation, showed antibacterial activity against Gram-positive and Gram-negative bacteria, and did not induce toxicity on human dermal fibroblasts. These novel biomaterials demonstrate great potential to be used for bone tissue engineering applications.

Glucose-Treated Manganese Hexacyanoferrate for Sodium-Ion Secondary Battery

Directory of Open Access Journals (Sweden)

Yutaka Moritomo

2015-09-01

Full Text Available Manganese hexacyanoferrate (Mn-PBA is a promising cathode material forsodium-ion secondary battery (SIB with high average voltage (=3.4 V against Na. Here,we find that the thermal decomposition of glucose modifies the surface state of Mn-PBA,without affecting the bulk crystal structure. The glucose treatment significantly improves therate properties of Mn-PBA in SIB. The critical discharge rate increases from 1 C (as-grownto 15 C (glucose-treated. Our observation suggests that thermal treatment is quite effectivefor insulating coordination polymers.

SU-E-J-212: MR Diffusion Tensor Imaging for Assessment of Tumor and Normal Brain Tissue Responses of Juvenile Pilocytic Astrocytoma Treated by Proton Therapy

Energy Technology Data Exchange (ETDEWEB)

Hou, P; Park, P; Li, H; Zhu, X; Mahajan, A; Grosshans, D [M.D. Anderson Cancer Center, Houston, TX (United States)

2015-06-15

Purpose: Diffusion tensor imaging (DTI) can measure molecular mobility at the cellular level, quantified by the apparent diffusion coefficient (ADC). DTI may also reveal axonal fiber directional information in the white matter, quantified by the fractional anisotropy (FA). Juvenile pilocytic astrocytoma (JPA) is a rare brain tumor that occurs in children and young adults. Proton therapy (PT) is increasingly used in the treatment of pediatric brain tumors including JPA. However, the response of both tumors and normal tissues to PT is currently under investigation. We report tumor and normal brain tissue responses for a pediatric case of JPA treated with PT assessed using DTI. Methods: A ten year old male with JPA of the left thalamus received passive scattered PT to a dose of 50.4 Gy (RBE) in 28 fractions. Post PT, the patient has been followed up in seven years. At each follow up, MRI imaging including DTI was performed to assess response. MR images were registered to the treatment planning CT and the GTV mapped onto each MRI. The GTV contour was then mirrored to the right side of brain through the patient’s middle line to represent normal brain tissue. ADC and FA were measured within the ROIs. Results: Proton therapy can completely spare contra lateral brain while the target volume received full prescribed dose. From a series of MRI ADC images before and after PT at different follow ups, the enhancement corresponding to GTV had nearly disappeared more than 2 years after PT. Both ADC and FA demonstrate that contralateral normal brain tissue were not affect by PT and the tumor volume reverted to normal ADC and FA values. Conclusion: DTI allowed quantitative evaluation of tumor and normal brain tissue responses to PT. Further study in a larger cohort is warranted.

SU-E-J-212: MR Diffusion Tensor Imaging for Assessment of Tumor and Normal Brain Tissue Responses of Juvenile Pilocytic Astrocytoma Treated by Proton Therapy

International Nuclear Information System (INIS)

Hou, P; Park, P; Li, H; Zhu, X; Mahajan, A; Grosshans, D

2015-01-01

Purpose: Diffusion tensor imaging (DTI) can measure molecular mobility at the cellular level, quantified by the apparent diffusion coefficient (ADC). DTI may also reveal axonal fiber directional information in the white matter, quantified by the fractional anisotropy (FA). Juvenile pilocytic astrocytoma (JPA) is a rare brain tumor that occurs in children and young adults. Proton therapy (PT) is increasingly used in the treatment of pediatric brain tumors including JPA. However, the response of both tumors and normal tissues to PT is currently under investigation. We report tumor and normal brain tissue responses for a pediatric case of JPA treated with PT assessed using DTI. Methods: A ten year old male with JPA of the left thalamus received passive scattered PT to a dose of 50.4 Gy (RBE) in 28 fractions. Post PT, the patient has been followed up in seven years. At each follow up, MRI imaging including DTI was performed to assess response. MR images were registered to the treatment planning CT and the GTV mapped onto each MRI. The GTV contour was then mirrored to the right side of brain through the patient’s middle line to represent normal brain tissue. ADC and FA were measured within the ROIs. Results: Proton therapy can completely spare contra lateral brain while the target volume received full prescribed dose. From a series of MRI ADC images before and after PT at different follow ups, the enhancement corresponding to GTV had nearly disappeared more than 2 years after PT. Both ADC and FA demonstrate that contralateral normal brain tissue were not affect by PT and the tumor volume reverted to normal ADC and FA values. Conclusion: DTI allowed quantitative evaluation of tumor and normal brain tissue responses to PT. Further study in a larger cohort is warranted

Oxidation and thermal shock behavior of thermal barrier coated 18/10CrNi alloy with coating modifications

Energy Technology Data Exchange (ETDEWEB)

Guergen, Selim [Vocational School of Transportation, Anadolu University, Eskisehir (Turkmenistan); Diltemiz, Seyid Fehmi [Turkish Air Force1st Air Supply and Maintenance Center Command, Eskisehir (Turkmenistan); Kushan, Melih Cemal [Dept. of Mechanical Engineering, Eskisehir Osmangazi University, Eskisehir (Turkmenistan)

2017-01-15

In this study, substrates of 18/10CrNi alloy plates were initially sprayed with a Ni-21Cr-10Al-1Y bond coat and then with an yttria stabilized zirconia top coat by plasma spraying. Subsequently, plasma-sprayed Thermal barrier coatings (TBCs) were treated with two different modification methods, namely, vacuum heat treatment and laser glazing. The effects of modifications on the oxidation and thermal shock behavior of the coatings were evaluated. The effect of coat thickness on the bond strength of the coats was also investigated. Results showed enhancement of the oxidation resistance and thermal shock resistance of TBCs following modifications. Although vacuum heat treatment and laser glazing exhibited comparable results as per oxidation resistance, the former generated the best improvement in the thermal shock resistance of the TBCs. Bond strength also decreased as coat thickness increased.

Thermal-stable proteins of fruit of long-living Sacred Lotus Nelumbo nucifera Gaertn var. China Antique.

Science.gov (United States)

Shen-Miller, J; Lindner, Petra; Xie, Yongming; Villa, Sarah; Wooding, Kerry; Clarke, Steven G; Loo, Rachel R O; Loo, Joseph A

2013-09-01

Single-seeded fruit of the sacred lotus Nelumbo nucifera Gaertn var. China Antique from NE China have viability as long as ~1300 years determined by direct radiocarbon-dating, having a germination rate of 84%. The pericarp, a fruit tissue that encloses the single seeds of Nelumbo , is considered one of the major factors that contribute to fruit longevity. Proteins that are heat stable and have protective function may be equally important to seed viability. We show proteins of Nelumbo fruit that are able to withstand heating, 31% of which remained soluble in the 110°C-treated embryo-axis of a 549-yr-old fruit and 76% retained fluidity in its cotyledons. Genome of Nelumbo is published. The amino-acid sequences of 11 "thermal proteins" (soluble at 100°C) of modern Nelumbo embryo-axes and cotyledons, identified by mass spectrometry, Western blot and bioassay, are assembled and aligned with those of an archaeal-hyperthermophile Methancaldococcus jannaschii (Mj; an anaerobic methanogen having a growth optimum of 85°C) and with five mesophile angiosperms. These thermal proteins have roles in protection and repair under stress. More than half of the Nelumbo thermal proteins (55%) are present in the archaean Mj, indicating their long-term durability and history. One Nelumbo protein-repair enzyme exhibits activity at 100°C, having a higher heat-tolerance than that of Arabidopsis. A list of 30 sequenced but unassembled thermal proteins of Nelumbo is supplemented.

Multispectral tissue characterization for intestinal anastomosis optimization

Science.gov (United States)

Cha, Jaepyeong; Shademan, Azad; Le, Hanh N. D.; Decker, Ryan; Kim, Peter C. W.; Kang, Jin U.; Krieger, Axel

2015-10-01

Intestinal anastomosis is a surgical procedure that restores bowel continuity after surgical resection to treat intestinal malignancy, inflammation, or obstruction. Despite the routine nature of intestinal anastomosis procedures, the rate of complications is high. Standard visual inspection cannot distinguish the tissue subsurface and small changes in spectral characteristics of the tissue, so existing tissue anastomosis techniques that rely on human vision to guide suturing could lead to problems such as bleeding and leakage from suturing sites. We present a proof-of-concept study using a portable multispectral imaging (MSI) platform for tissue characterization and preoperative surgical planning in intestinal anastomosis. The platform is composed of a fiber ring light-guided MSI system coupled with polarizers and image analysis software. The system is tested on ex vivo porcine intestine tissue, and we demonstrate the feasibility of identifying optimal regions for suture placement.

Loss and thermal model for power semiconductors including device rating information

DEFF Research Database (Denmark)

Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon

2014-01-01

The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal models, only the electrical loadings are focused and treated as design variables, while the device rating is normally...

Thermally treated polyaniline/polybenzimidazole blend membranes: structural changes and gas transport properties

Czech Academy of Sciences Publication Activity Database

Giel, Verena; Morávková, Zuzana; Peter, Jakub; Trchová, Miroslava

2017-01-01

Roč. 537, 1 September (2017), s. 315-322 ISSN 0376-7388 R&D Projects: GA MŠk(CZ) LO1507; GA ČR(CZ) GA16-02787S Institutional support: RVO:61389013 Keywords : polybenzimidazole * polyaniline * thermal treatment Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 6.035, year: 2016

Effects of alkali treatment on the mechanical and thermal properties of Sansevieria trifasciata fiber

Science.gov (United States)

Mardiyati, Steven, Rizkiansyah, Raden Reza; Senoaji, A.; Suratman, R.

2016-04-01

In this study, Sansevieria trifasciata fibers were treated by NaOH with concentration 1%,3%, and 5wt% at 100°C for 2 hours. Chesson-Datta methods was used to determine the lignocellulose content of raw sansevieria fibers and to investigate effect of alkali treatment on lignin content of the fiber. Mechanical properties and thermal properties of treated and untreated fibers were measured by means of tensile testing machine and thermogravimetric analysis (TGA).The cellulose and lignin contents of raw sansevieria fiber obtained from Chesson-Datta method were 56% and 6% respectively. Mechanical testing of fibers showed the increase of tensile strength from 647 MPa for raw fibers to 902 MPa for 5wt% NaOH treated fibers. TGA result showed the alkali treatment increase the thermal resistance of fibers from 288°C for raw fibers to 307°C for 5% NaOH treated fiber. It was found that alkali treatment affect the mechanical properties and thermal properties of sansevieria fibers.

Tissue analysis of Clarias gariepinus juveniles injected with different ...

African Journals Online (AJOL)

The starch value (SV) and unsaponification values (USPV) were not affected, the saponification value (SPV) only increased between 25.00 and 0.0 μlg-1 and declined at 75 μlg-1. The decrease in values of SPV in treated fish tissues has implication on energy metabolism. Of the four tissues values (PV, SV, SPV and USPV) ...

Fibrolipoma of the lip treated by diode laser surgery: A case report

Directory of Open Access Journals (Sweden)

Capodiferro Saverio

2008-09-01

Full Text Available Abstract Introduction Several neoplasms of the adipose tissue can involve the soft tissues of the head and neck region. These neoplasms are mainly treated surgically and an accurate histological examination is mandatory for a precise diagnosis. Case presentation We report a case of fibrolipoma involving the lower lip of a 43-year-old man, which was successfully treated by diode laser surgery. This approach allowed adequate resection of the neoplasm with minimal damage to the adjacent tissues, thus reducing post-surgical scarring. Conclusion Diode laser surgery for the treatment of benign lesions of the oral mucosa appears to be a convenient alternative to conventional blade surgery and has proved to be effective for the excision of fibrolipoma of the lip. The possibility of avoiding direct suture after excision is surely helpful when aesthetic areas, such as the lip, are surgically treated. For these reasons, and also considering the lower histological alteration of the specimen obtained with diode laser surgery if adequately used, the diode laser is undoubtedly a good alternative to conventional surgery.

Multiscale thermal transport.

Energy Technology Data Exchange (ETDEWEB)

Graham, Samuel Jr. (; .); Wong, C. C.; Piekos, Edward Stanley

2004-02-01

A concurrent computational and experimental investigation of thermal transport is performed with the goal of improving understanding of, and predictive capability for, thermal transport in microdevices. The computational component involves Monte Carlo simulation of phonon transport. In these simulations, all acoustic modes are included and their properties are drawn from a realistic dispersion relation. Phonon-phonon and phonon-boundary scattering events are treated independently. A new set of phonon-phonon scattering coefficients are proposed that reflect the elimination of assumptions present in earlier analytical work from the simulation. The experimental component involves steady-state measurement of thermal conductivity on silicon films as thin as 340nm at a range of temperatures. Agreement between the experiment and simulation on single-crystal silicon thin films is excellent, Agreement for polycrystalline films is promising, but significant work remains to be done before predictions can be made confidently. Knowledge gained from these efforts was used to construct improved semiclassical models with the goal of representing microscale effects in existing macroscale codes in a computationally efficient manner.

Tissue integration of polyacrylamide hydrogel: an experimental study of periurethral, perivesical, and mammary gland tissue in the pig

DEFF Research Database (Denmark)

Christensen, Lise H; Nielsen, John B; Mouritsen, Lone

2008-01-01

BACKGROUND Polyacrylamide hydrogel (PAAG) is a nondegradable water-based polymer with high viscoelasticity. The gel is used as a tissue filler, the only risk being prolonged infection with anaerobic, contaminating microorganisms if not treated early with broad-spectrum antibiotics. OBJECTIVE...... With silicone gel as reference, PAAG tissue integration and migration was studied in a longitudinal study of the pig. MATERIALS AND METHODS Forty-one pigs were used. PAAG and silicone gel were injected into mammary tissue, and PAAG was injected into urethral or bladder wall or the anal canal. Tissues...... and regional lymph nodes were examined at 1, 1 1/2, 3, 3 1/2, 6, 12, and 14 months, and other lymph nodes and organs were examined at 1, 6, 12, and 14 months. RESULTS PAAG was invaded by macrophages and giant cells that were gradually replaced by a network of fibrous tissue. Silicone gel was seen inside...

Magnetomotive optical coherence elastography (MM-OCE) for thermal therapy dosimetry (Conference Presentation)

Science.gov (United States)

Huang, Pin-Chieh; Marjanovic, Marina; Spillman, Darold R.; Odintsov, Boris M.; Boppart, Stephen A.

2016-03-01

Biomechanical properties of tissues have been utilized for disease detection, diagnosis, and progression, however they have not been extensively utilized for therapy dosimetry. Magnetic hyperthermia aims to kill cells and ablate tumors using magnetic nanoparticles (MNPs) either injected in or targeted to tumors. Upon application of an appropriate AC magnetic field, MNPs can heat target tissue while sparing non-targeted healthy tissue. However, a sensitive monitoring technique for the dose of magnetic hyperthermia is needed to prevent over-treatment and collateral injury. During hyperthermia treatments, the viscoelastic properties of tissues are altered due to protein denaturation, coagulation, and tissue dehydration, making these properties candidates for dosimetry. Magnetomotive optical coherence elastography (MM-OCE) utilizes MNPs as internal force transducers to probe the biomechanical properties of tissues. Therefore, we aim to evaluate the hyperthermia dose based on the elastic changes revealed by MM-OCE. In this study, MNPs embedded in tissues were utilized for both hyperthermia and MM-OCE measurements. Tissue temperature and elastic modulus were obtained, where the elastic modulus was extracted from the resonance frequency detected by MM-OCE. Results showed a correlation between stiffness and temperature change following treatment. To investigate the thermal-dose-dependent changes, intervals of hyperthermia treatment were repeatedly performed on the same tissue sequentially, interspersed with MM-OCE. With increasing times of treatment, tissue stiffness increased, while temperature rise remained relatively constant. These results suggest that MM-OCE may potentially identify reversible and irreversible tissue changes during thermal therapy, supporting the use of MM-OCE for dosimetric control of hyperthermia in future applications.

Correlation of p63 immunohistochemistry with histology and contrast enhanced MRI in characteristic lesions induced by minimally invasive thermal treatments in a dog prostate

Science.gov (United States)

Pascal, A.; Butts-Pauly, K.; Plata, J.; Sommer, G.; Daniel, B.; Bouley, D. M.

2017-03-01

Thermal ablation techniques are important tools to treat low grade tumors in the prostate gland. The use of Magnetic Resonance Imaging (MRI) has been an excellent tool to visualize and assess the thermally ablated areas in real time. In this study slides from dog prostates previously treated with cryoablation or High Intensity Focal Ultrasound (HIFU) were immunohistochemically stained with the biomarker p63, in order to determine if this marker would be helpful for differentiatiating between viable, sub lethally damaged and normal glands. Digitized slides were analyzed using Sedeen Viewer software, and compared with corresponding representative H&E slides and MR images. p63 staining in the cryoablated acute duration prostates was negative in the coagulation necrosis zone (region of interest subjected to the coldest temperatures). In acute duration HIFU treated prostates, the central heat-fixed zone (region of interest subjected to the hottest temperatures) still displayed + p63 staining. Cryoablated or HIFU subacute duration treated prostates were very hemorrhagic, but presented the same stain pattern in the treated areas as the acute duration prostates, and in chronic duration prostates, whether treated with cryo or HIFU, glands displayed robust p63 staining most prevalent in the outer edges of the lesion where there was extensive glandular regeneration. In conclusion, this study demonstrates the value of p63 IHC and its usefulness in detecting viable prostate basal cells in normal dog prostates following either cryoablation of HIFU. Our results suggest that the portions of the lesion with complete loss of p63 staining correspond well to the non-enhancing region in cryoablated prostates, as viewed with MRI. However, p63 staining in the heat-fixed zone in acute harvested HIFU treated prostates remains positive, suggesting either inadequate heat to destroy basal cells, or heat-fixation of the p63 antigen and false positive staining. Therefore p63 staining does not

Tissue Engineering: Current Strategies and Future Directions

OpenAIRE

Olson, Jennifer L.; Atala, Anthony; Yoo, James J.

2011-01-01

Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, or other clinical issues. Currently, patients with diseased and injured organs are often treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and as the number of new cases of organ failure increases. Scientists in the field of regenerative medicine and tissue eng...

Tissue engineering in dentistry.

Science.gov (United States)

Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Salih, Vehid M; Kim, Hae-Won; Knowles, Jonathan C

2014-08-01

of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry. The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa". Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry. Only those articles that dealt with the tissue engineering in dentistry were selected. There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region. Considering the

Non-invasive characterization of normal and pathological tissues through dynamic infrared imaging in the hamster cheek pouch oral cancer model

Science.gov (United States)

Herrera, María. S.; Monti Hughes, Andrea; Salva, Natalia; Padra, Claudio; Schwint, Amanda; Santa Cruz, Gustavo A.

2017-05-01

Biomedical infrared thermography, a non-invasive and functional imaging method, provides information on the normal and abnormal status and response of tissues in terms of spatial and temporal variations in body infrared radiance. It is especially attractive in cancer research due to the hypervascular and hypermetabolic activity of solid tumors. Moreover, healthy tissues like skin or mucosa exposed to radiation can be examined since inflammation, changes in water content, exudation, desquamation, erosion and necrosis, between others, are factors that modify their thermal properties. In this work we performed Dynamic Infrared Imaging (DIRI) to contribute to the understanding and evaluation of normal tissue, tumor and precancerous tissue response and radiotoxicity in an in vivo model, the hamster cheek pouch, exposed to Boron Neutron Capture Therapy. In this study, we particularly focused on the observation of temperature changes under forced transient conditions associated with mass moisture transfer in the tissue-air interface, in each tissue with or without treatment. We proposed a simple mathematical procedure that considerers the heat transfer from tissue to ambient through convection and evaporation to model the transient (exponential decay o recover) thermal study. The data was fitted to determined the characteristic decay and recovery time constants of the temperature as a function of time. Also this model allowed to explore the mass flux of moisture, as a degree of evaporation occurring on the tissue surface. Tissue thermal responses under provocation tests could be used as a non-invasive method to characterize tissue physiology.

Phase change material thermal capacitor clothing

Science.gov (United States)

Buckley, Theresa M. (Inventor)

2005-01-01

An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the apparatus also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

Effects of Surface Nitrification on Thermal Conductivity of Modified Aluminum Oxide Nanofibers-Reinforced Epoxy Matrix Nanocomposites

International Nuclear Information System (INIS)

Kim, Byungjoo; Bae, Kyongmin; An, Kayhyeok; Park, Soojin

2012-01-01

Aluminum oxide (Al 2 O 3 ) nanofibers were treated thermally under an ammonia (NH 3 ) gas stream balanced by nitrogen to form a thin aluminum nitride (AlN) layer on the nanofibers, resulting in the enhancement of thermal conductivity of Al 2 O 3 /epoxy nanocomposites. The micro-structural and morphological properties of the NH 3 -assisted thermally-treated Al 2 O 3 nanofibers were characterized by X-ray diffraction (XRD) and atomic force microscopy (AEM), respectively. The surface characteristics and pore structures were observed by X-ray photoelectron spectroscopy (XPS), Zeta-potential and N 2 /77 K isothermal adsorptions. From the results, the formation of AlN on Al 2 O 3 nanofibers was confirmed by XRD and XPS. The thermal conductivity (TC) of the modified Al 2 O 3 nanofibers/epoxy composites increased with increasing treated temperatures. On the other hand, the severely treated Al 2 O 3 /epoxy composites showed a decrease in TC, resulting from a decrease in the probability of heat-transfer networks between the filler and matrix in this system due to the aggregation of nanofiber fillers

Fabrication, thermal properties and thermal stabilities of microencapsulated n-alkane with poly(lauryl methacrylate) as shell

International Nuclear Information System (INIS)

Qiu, Xiaolin; Lu, Lixin; Wang, Ju; Tang, Guoyi; Song, Guolin

2015-01-01

Highlights: • Microencapsulation of octadecane and paraffin by crosslinked poly(lauryl methacrylate). • Octadecane microcapsules have a melting enthalpy of about 118 J g −1 . • Weight loss temperatures of the microcapsules were increased by 67 °C and 28 °C. • Phase change enthalpies decreased by around 10 wt% after 500 thermal cycles. • Foams with microcapsules can be applied for passive temperature control. - Abstract: Microencapsulation of n-octadecane or paraffin with poly(lauryl methacrylate) (PLMA) shell was performed by a suspension-like polymerization. The polymer shell was crosslinked by pentaerythritol tetraacrylate (PETRA). The surface morphologies of microcapsules were investigated by scanning electron microscopy (SEM). Phase change properties, thermal reliabilities and thermal stabilities of microcapsules were determined by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The n-octadecane microcapsule exhibits higher melting enthalpy (118.0 J g −1 ) and crystallization enthalpy (108.3 J g −1 ) compared with the paraffin microcapsule. The thermal resistant temperatures were enhanced by more than 25 °C when n-alkanes were microencapsulated by PLMA. The PCM contents of microcapsules decreased by less than 4 wt% and 6 wt% after 500 and 1000 thermal cycles, respectively. Heat-up experiments indicated that microcapsule-treated foams exhibited upgraded thermal regulation capacities. Consequently, microencapsulated n-octadecane or paraffin with PLMA as shell possesses good potentials for heat storage and thermal regulation.

High-frequency irreversible electroporation (H-FIRE for non-thermal ablation without muscle contraction

Directory of Open Access Journals (Sweden)

Arena Christopher B

2011-11-01

Full Text Available Abstract Background Therapeutic irreversible electroporation (IRE is an emerging technology for the non-thermal ablation of tumors. The technique involves delivering a series of unipolar electric pulses to permanently destabilize the plasma membrane of cancer cells through an increase in transmembrane potential, which leads to the development of a tissue lesion. Clinically, IRE requires the administration of paralytic agents to prevent muscle contractions during treatment that are associated with the delivery of electric pulses. This study shows that by applying high-frequency, bipolar bursts, muscle contractions can be eliminated during IRE without compromising the non-thermal mechanism of cell death. Methods A combination of analytical, numerical, and experimental techniques were performed to investigate high-frequency irreversible electroporation (H-FIRE. A theoretical model for determining transmembrane potential in response to arbitrary electric fields was used to identify optimal burst frequencies and amplitudes for in vivo treatments. A finite element model for predicting thermal damage based on the electric field distribution was used to design non-thermal protocols for in vivo experiments. H-FIRE was applied to the brain of rats, and muscle contractions were quantified via accelerometers placed at the cervicothoracic junction. MRI and histological evaluation was performed post-operatively to assess ablation. Results No visual or tactile evidence of muscle contraction was seen during H-FIRE at 250 kHz or 500 kHz, while all IRE protocols resulted in detectable muscle contractions at the cervicothoracic junction. H-FIRE produced ablative lesions in brain tissue that were characteristic in cellular morphology of non-thermal IRE treatments. Specifically, there was complete uniformity of tissue death within targeted areas, and a sharp transition zone was present between lesioned and normal brain. Conclusions H-FIRE is a feasible technique for

Thermal mapping on male genital and skin tissues of laptop thermal sources and electromagnetic interaction.

Science.gov (United States)

Safari, Mahdi; Mosleminiya, Navid; Abdolali, Ali

2017-10-01

Since the development of communication devices and expansion of their applications, there have been concerns about their harmful health effects. The main aim of this study was to investigate laptop thermal effects caused by exposure to electromagnetic fields and thermal sources simultaneously; propose a nondestructive, replicable process that is less expensive than clinical measurements; and to study the effects of positioning any new device near the human body in steady state conditions to ensure safety by U.S. and European standard thresholds. A computer simulation was designed to obtain laptop heat flux from SolidWorks flow simulation. Increase in body temperature due to heat flux was calculated, and antenna radiation was calculated using Computer Simulation Technology (CST) Microwave Studio software. Steady state temperature and specific absorption rate (SAR) distribution in user's body, and heat flux beneath the laptop, were obtained from simulations. The laptop in its high performance mode caused 420 (W/m 2 ) peak two-dimensional heat flux beneath it. The cumulative effect of laptop in high performance mode and 1 W antenna radiation resulted in temperatures of 42.9, 38.1, and 37.2 °C in lap skin, scrotum, and testis, that is, 5.6, 2.1, and 1.4 °C increase in temperature, respectively. Also, 1 W antenna radiation caused 0.37 × 10 -3 and 0.13 × 10 -1 (W/kg) peak three-dimensional SAR at 2.4 and 5 GHz, respectively, which could be ignored in reference to standards and temperature rise due to laptop use. Bioelectromagnetics. 38:550-558, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Soft tissue freezing process. Identification of the dual-phase lag model parameters using the evolutionary algorithm

Science.gov (United States)

Mochnacki, Bohdan; Majchrzak, Ewa; Paruch, Marek

2018-01-01

In the paper the soft tissue freezing process is considered. The tissue sub-domain is subjected to the action of cylindrical cryoprobe. Thermal processes proceeding in the domain considered are described using the dual-phase lag equation (DPLE) supplemented by the appropriate boundary and initial conditions. DPLE results from the generalization of the Fourier law in which two lag times are introduced (relaxation and thermalization times). The aim of research is the identification of these parameters on the basis of measured cooling curves at the set of points selected from the tissue domain. To solve the problem the evolutionary algorithms are used. The paper contains the mathematical model of the tissue freezing process, the very short information concerning the numerical solution of the basic problem, the description of the inverse problem solution and the results of computations.

Thermal plasmas: fundamental aspects

International Nuclear Information System (INIS)

Fauchais, P.

2005-01-01

This article treats of thermal plasmas, i.e. mainly produced by electric arcs and RF discharges. Their main characteristic is that they are generated at a pressure close to the atmospheric pressure (between 10 4 and 10 6 Pa) and refer to the classical kinetics of the Boltzmann equation. Because of the pressure, the collisions between particles are numerous and ionization is mainly due to a thermal effect. They correspond to electron densities between 10 20 and 10 24 m -3 and temperatures between 6000 and 25000 K. In these plasmas, the electric fields and the average free trajectories are too weak to generate a ionization state by direct inelastic collision. Ionization is thus essentially a thermal phenomenon due to elastic collisions. This article presents: 1 - the particles present in a plasma: definition, energy states; 2 - characteristic data: collisions, average free path and collision cross-section, distribution function, ionization types, charged particles mobility inside an electric field, scattering, Debye length; 3 - plasmas at the thermodynamical equilibrium: conditions of equilibrium, calculation of composition, thermodynamic properties, transport properties, radiation; 4 - thermal plasmas away from equilibrium: conditions of non-equilibrium, calculation of plasma composition, calculation of transport properties, quenching phenomenon. (J.S.)

NMR imaging of cell phone radiation absorption in brain tissue

Science.gov (United States)

Gultekin, David H.; Moeller, Lothar

2013-01-01

A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry. PMID:23248293

Treatment of mixed wastes by thermal plasma discharges

International Nuclear Information System (INIS)

Diaz A, L.V.

2007-01-01

The present study has as purpose to apply the technology of thermal plasma in the destruction of certain type of waste generated in the ININ. As first instance, origin, classification and disposition of the radioactive waste generated in the ININ is identified. Once identified the waste, the waste to treat is determined based on: the easiness of treating him with plasma, classification and importance. Later on, a substance or compound settles down (sample model) that serves as indicative of the waste for its physical-chemical characteristics, this is made because in the Thermal Plasma Applications Laboratory is not had the license to work with radioactive material. The sample model and the material to form the vitreous matrix are characterized before and after the treatment in order to evaluating their degradation and vitrification. During the treatment by means of the thermal plasma, the appropriate conditions are determined for the degradation and vitrification of the waste. Also, it is carried out an energy balance in the system to know the capacity to fuse the material depending the transfer of existent heat between the plasma and the material to treat. Obtaining favorable results, it thought about to climb in the project and by this way to help to solve one of the environmental problems in Mexico, as they are it the mixed wastes. (Author)

Soft tissue response in orthognathic surgery patients treated by bimaxillary osteotomy: cephalometry compared with 2-D photogrammetry.

Science.gov (United States)

Rustemeyer, Jan; Martin, Alice

2013-03-01

Since improvement of facial aesthetics after orthognathic surgery moves increasingly into the focus of patients, prediction of soft tissue response to hard tissue movement becomes essential for planning. The aim of this study was to assess the facial soft tissue response in skeletal class II and III patients undergoing orthognathic surgery and to compare the potentials of cephalometry and two-dimensional (2-D) photogrammetry for predicting soft tissue changes. Twenty-eight patients with class II relationship and 33 with class III underwent bimaxillary surgery. All subjects had available both a traced lateral cephalogram and a traced lateral photogram taken pre- and postsurgery in natural head position (median follow-up, 9.4 ± 0.6 months). Facial convexity and lower lip length were highly correlated with hard tissue movements cephalometrically in class III patients and 2-D photogrammetrically in both classes. In comparison, cephalometric correlations for class II patients were weak. Correlations of hard and soft tissue movements between pre- and postoperative corresponding landmarks in horizontal and vertical planes were significant for cephalometry and 2-D photogrammetry. No significant difference was found between cephalometry and 2-D photogrammetry with respect to soft to hard tissue movement ratios. This study revealed that cephalometry is still a feasible standard for evaluating and predicting outcomes in routine orthognathic surgery cases. Accuracy could be enhanced with 2-D photogrammetry, especially in class II patients.

Effect of acid treatment on thermal extraction yield in ashless coal production

Energy Technology Data Exchange (ETDEWEB)

Chunqi Li; Toshimasa Takanohashi; Takahiro Yoshida; Ikuo Saito; Hideki Aoki; Kiyoshi Mashimo [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan). Institute for Energy Utilization

2004-04-01

Coals of different ranks were acid-treated in aqueous methoxyethoxy acetic acid (MEAA), acetic acid (AA), and HCl. The acid-treated coals were extracted with polar N-methyl-2-pyrrolidinone (NMP) and nonpolar 1-methylnaphthalene (1MN) solvents at temperatures from 200 to 360{sup o}C for 10 60 min. The thermal extraction yields with NMP for some acid-treated low-rank coals increased greatly; for example, the extraction yield for Wyodak coal (%C; 75.0%) increased from 58.4% for the raw coal to 82.9% for coal treated in 1.0 M MEAA. Conversely, the extraction yields changed minimally for all the acid-treated coals extracted in 1-MN. The type and concentration of acid affected the extraction yield when NMP was used as the extraction solvent. With increasing MEAA concentration from 0.01 to 0.1 M, the extraction yield for Wyodak coal increased from 66.3 to 81.4%, and subsequently did not change clearly with concentration. Similar changes in the extraction yield with acid concentration were also observed with AA and HCl. The de-ashing ratio for coals acid-treated in MEAA, AA, and HCl also increased greatly with concentration from 0.01 to 0.1 M, which corresponded to the change in the thermal extraction yield in NMP. For the acid-treated coals, high extraction yields were obtained at lower extraction temperatures and shorter extraction times than for the raw coal. The mechanisms for the acid treatment and thermal extraction are discussed. 27 refs., 6 figs., 3 tabs.