WorldWideScience

Sample records for argon laser treatment

  1. Argon laser treatment of central serous chorioretinopathy

    Directory of Open Access Journals (Sweden)

    Ting- Bing Fang

    2013-04-01

    Full Text Available AIM: To observe the efficacy of the argon laser photocoagulation treatment of central serous chorioretinopathy(CSC. METHODS: The treatment groups: 18 patients(18 eyes, argon laser photocoagulation and oral jolethin, vitamin B1, inosine and venoruton tablets. Control group: 18 patients(18 eyes, oral lecithin complex iodine, vitamin B1, inosine, venoruton tablets. Foveal thickness and neuroepithelial layer detachment range were measured by optical coherence tomography(OCTbefore treatment, after 1 month and 3 months post-operation to compare the decline in value of foveal thickness and neuroepithelial layer detachment range of the two groups. RESULTS: After 1 month of treatment, the decline in value of the center foveal thickness: the value of treatment group was 256±72μm; the value of the control group was 82±57μm, and the difference of the two groups, P <0.05; the decline in value of neuroepithelial layer detachment range: the value of the treatment group was 3 548±168μm, the value of the control group was 1 520±143μm, And the difference of the two groups, P<0.05. After three months of treatment, the decline in value of the center foveal thickness: the value of treatment group was 383±75μm, the value of the control group was 312±67 μm, and the difference of the two groups, P<0.05; decline in value of neuroepithelial layer detachment range: the value of the treatment group was 4 908±172μm, the value of the control group was 4 211±153μm, and the difference of the two groups, P <0.05. The differences were statistically significant between the treatment and the control groups(two independent samples t-test. CONCLUSION:Argon laser photocoagulation treatment of CSC is an effective treatment method and can significantly shorten the course.

  2. The argon excimer laser

    International Nuclear Information System (INIS)

    Wrobel, W.G.

    1981-02-01

    The electron-beam-pumped argon eximer laser is investigated and tuned for the first time. The electron beam is generated by means of an improved coaxial field emmision diode in which argon gas is excited with power densities of 0.3 GW/cm 3 for 18 ns. The processes in the excited gas of 20 to 65 bar are described in the context of a kinetic model as a sequence of stationary states. Investigations of the amplified spontaneous emission (superfluorescence) confirm the predictions of this model. Only the absorption due to the excited Ar atoms is anomalously high. Reproducible operation of the argon eximer laser was achieved in a wide pressure range with various resonator arrangements. The wavelength of this shortest wavelength of this shortest wavelength excimer laser is 126 nm, the laser line width approx. 1.7 nm, the pulse length 7 to 13 ns, and the laser power 250 kW. The laser emission is tuned from 123.2 nm to 128.4 nm by two different methods (diffraction grating and prism). This tunable laser is thus the one with the shortest wavelength at present. Its line width is 0.25 to 0.4 nm, and the power ue 1.7 kW. (orig.)

  3. Argon laser in the treatment of diabetic retinopathy (Preliminary communication)

    International Nuclear Information System (INIS)

    Saprykin, P.I.; Simonova, K.K.; Belyaeva, M.I.

    1974-01-01

    The complications observed in the photocoagulation treatment of diabetic angiopathy and retinopathy include the following conditions: tractional retinal detachment, accelerated development of proliferating retinitis and massive hemmorrhaging into the vitreous body. (V.A.P.)

  4. Argon green-Nd: YAG dual laser posterior hyaloidotomy: An innovative approach toward treatment of premacular hemorrhage

    Directory of Open Access Journals (Sweden)

    Ashish Sharma

    2013-01-01

    Full Text Available Background: Neodymium: YAG (Nd: YAG laser and argon laser has been used to treat premacular hemorrhage either alone or rarely in combination. Materials and Methods: We describe a new technique of treating premacular hemorrhage by performing hyaloidotomy using a combination of argon green-Nd: YAG laser. We utilized subthreshold energy levels of Nd: YAG laser of 2.0 mJ as compared to the normal recommendation of 3.6-50 mJ. Results and Conclusions: This technique is easy, effective, and safe to manage premacular hemorrhage. The principle behind this combined laser treatment was to make the internal limiting membrane (ILM taut by initial exposure to argon green laser, which allowed us to employ the subthreshold energy levels of Nd: YAG laser. We would like to assess the role of this combined treatment modality in comparison to other modalities, including solitary laser therapy in the management of premacular hemorrhage by performing a prospective, randomized long-term study.

  5. Vascular anastomosis by Argon Laser

    International Nuclear Information System (INIS)

    Gomes, O.M.; Macruz, R.; Armelin, E.; Brum, J.M.G.; Ribeiro, M.P.; Mnitentog, J.; Verginelli, G.; Pileggi, F.; Zerbini, E.J.

    1982-01-01

    Twenty four mongrel dogs, wheighing 13 to 24 kilograms were studied. After anesthesia, intubation and controlled ventilation, they were submitted to three types of vascular anastomosis: Group I - eight dogs with saphenous vein inter-carotid arteries by-pass: Group II - eight dogs with left mammary artery - left anterior descending coronary artery by-pass; Group III - eight dogs with venovenous anastomosis. In all groups 0.8 to 15 watts of Argon Laser power was applied to a total time of 90 to 300 seconds. The lower power for venovenous anastomosis and the greater for the arterial ones. The mean valves of resistence of the Laser anastomosis to pressure induced rupture was 730 mmHg in the immediate post operative study, and superior to 2.500 mmHg 30 days after. No signs of occlusion was demonstrated at the anastomosis sites by the angiographic and anathomo-patological study performed. (Author) [pt

  6. Argon laser induced changes to the carbonate content of enamel

    International Nuclear Information System (INIS)

    Ziglo, M.J.; Nelson, A.E.; Heo, G.; Major, P.W.

    2009-01-01

    Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457-502 nm; 250 mW cm -2 ) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation (p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

  7. Argon laser induced changes to the carbonate content of enamel

    Energy Technology Data Exchange (ETDEWEB)

    Ziglo, M.J. [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta, Private Practice, Regina, Saskatchewan (Canada); Nelson, A.E., E-mail: aenelson@dow.com [Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta (Canada); Heo, G.; Major, P.W. [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta (Canada)

    2009-05-15

    Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457-502 nm; 250 mW cm{sup -2}) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation (p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

  8. Argon laser induced changes to the carbonate content of enamel

    Science.gov (United States)

    Ziglo, M. J.; Nelson, A. E.; Heo, G.; Major, P. W.

    2009-05-01

    Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457-502 nm; 250 mW cm -2) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation ( p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

  9. Angiolymphoid hyperplasia with eosinophilia-acquired port-wine-stain-like lesions: attempt at treatment with the argon laser.

    Science.gov (United States)

    Pasyk, K A; Elsenety, E N; Schelbert, E B

    1988-01-01

    An unusual case of angiolymphoid hyperplasia with eosinophilia (ALHE) simulating port-wine stain in a 50-year-old woman is reported. The lesions of ALHE are typically papules or subcutaneous masses that range from light pink to red-brown in color. In addition to the usual histologic findings of ALHE, the biopsy in our patient showed some fibrin-like material and fibrous long-spacing collagen on ultrastructural examination. This unusual lesion necessitates biopsy because the differential diagnosis includes port-wine stain, sarcoidosis, lupus erythematosus, and non-Hodgkin lymphoma (mycosis fungoides). Many different forms of treatment have been attempted for ALHE including radiotherapy, cytotoxic chemotherapy, corticosteroids, and antibiotics. The lesions in our patient responded to argon laser therapy and surgical excision, though there has been recurrence on the border of the treated area. Because laser energy is noncumulative in the tissues and effective in removing the lesions, we recommend it as the treatment of choice for these lesions.

  10. Argon laser photocoagulation of cyclodialysis clefts after cataract surgery

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, B. [Univ. of Lund, Dept. of Ophthalmology, Lund (Sweden)

    1995-06-01

    Three patients with cyclodialysis clefts, hypotony and hypotonic retinopathy subsequent to cataract surgery were treated with argon laser photocoagulation. The hypotony was reversed in each patient and their visual acuity was normalized. Laser photocoagulation is a noninvasive treatment that can be repeated easily and safely. The complications of the treatment are minor. A hypertensive episode commonly occurs in the early postoperative period. (au) 8 refs.

  11. Argon laser application to endodontics

    Science.gov (United States)

    Blankenau, Richard J.; Ludlow, Marvin; Anderson, David

    1993-07-01

    The application of laser technology to endodontics has been studied for some time. At the present time several major problems are being investigated: (1) removal of infected tissues, (2) sterilization of canals, (3) obturation of canals, and (4) preservation of the vitality of supporting tissues. This list is not intended to imply other problems do not exist or have been solved, but it is a starting point. This paper reviews some of the literature that relates to laser applications to endodontics and concludes with some of the findings from our investigation.

  12. Argon laser irradiation of the otolithic organ

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, T.; Nomura, Y.; Young, Y.H.; Hara, M. (Univ. of Tokyo (Japan))

    1990-12-01

    An argon laser was used to irradiate the otolithic organs of guinea pigs and cynomolgus monkeys. After stapedectomy, the argon laser (1.5 W x 0.5 sec/shot) irradiated the utricle or saccule without touching the sensory organs. The stapes was replaced over the oval window after irradiation. The animals used for acute observation were killed immediately for morphologic studies; those used for long-term observation were kept alive for 2, 4, or 10 weeks. Acute observation revealed that sensory and supporting cells were elevated from the basement membrane only in the irradiated area. No rupture of the membranous labyrinth was observed. Long-term observation revealed that the otolith of the macula utriculi had disappeared in 2-week specimens. The entire macula utricili had disappeared in 10-week specimens. No morphologic changes were observed in cochlea, semicircular canals, or membranous labyrinth. The saccule showed similar changes.

  13. Dermatological laser treatment

    International Nuclear Information System (INIS)

    Moerk, N.J.; Austad, J.; Helland, S.; Thune, P.; Volden, G.; Falk, E.

    1991-01-01

    The article reviews the different lasers used in dermatology. Special emphasis is placed on the treatment of naevus flammeus (''portwine stain'') where lasers are the treatment of choice. Argon laser and pulsed dye laser are the main lasers used in vascular skin diseases, and the article focuses on these two types. Copper-vapour laser, neodymium-YAG laser and CO 2 laser are also presented. Information is provided about the availability of laser technology in the different health regions in Norway. 5 refs., 2 figs

  14. Argon laser trabeculoplasty as primary therapy in open angle glaucoma

    International Nuclear Information System (INIS)

    Mahar, P.S.; Jamali, K.K.

    2008-01-01

    To determine the effect of Argon Laser Trabeculoplasty (ALT) as a primary mode of therapy in reducing the intraocular Pressure (IOP) of patients diagnosed with Primary Open Angle Glaucoma (POAG). A total of 35 eyes of 35 patients with the gender distribution of 27 men and 8 women who were newly diagnosed with POAG, were included in this study. Mean age of the patients was 55.2 years with the range of 32 to 76 years. All of them were treated with argon laser trabeculoplasty as a primary mode of therapy. Intra ocular pressure was measured objectively using Goldman applanation tonometer, pre-and-post laser therapy. The pre-laser mean IOP was 27.63 mmHg (range 21-40 mmHg). The post-laser mean IOP measured at 6 months follow up was 15.5 mmHg (range 11 - 33 mmHg) with mean decrease of 12.1 mmHg. The decrease in IOP was seen in 32 eyes (95%) with no change observed in 3 (5%) eyes. The result shows a marked decline in IOP in patients with POAG who underwent ALT as a primary mode of treatment. Further studies with large sample size and longer follow-up will help in making future recommendations. (author)

  15. Argon laser phototherapy of human malignancies using rhodamine-123 as a new laser dye: The intracellular role of oxygen

    International Nuclear Information System (INIS)

    Castro, D.J.; Saxton, R.E.; Markley, J.; Foote, C.S.; Fetterman, H.R.; Castro, D.J.; Ward, P.H.

    1990-01-01

    Recent studies demonstrated that the cationic, mitochondrial-specific dye Rhodamine-123 (Rh-123), is an efficient tumor photosensitizer for Argon laser treatment of human cancer cells both in vitro and in tumors grown as xenografts in athymic mice. To demonstrate the photodynamic mechanism of action of this reaction, the intracellular role of oxygen and temperature changes in treated cells have to be defined. In the current study, a large panel of human tumor cell lines of diverse histologic origin were tested for in vitro sensitivity to Rh-123 and the Argon laser (514.5 nm) in oxygen, deuterium oxide (D2O), and nitrogen (N2) environment. Tumor cells in suspension were first sensitized to Rh-123 (1 or 20 micrograms/ml for 1 hour), cooled on ice to 4 degrees C, and then exposed to the Argon laser (delta T = 14 +/- 1 degree C). Cell proliferation measured by [3H]-thymidine uptake 24 hours after sensitization with Rh-123 and laser treatment was significantly decreased in tumor cells kept in oxygen and D2O atmospheres. No decrease in DNA synthesis was seen in Rh-123 and laser treated cells kept in an N2 environment. Control tumor cells treated with Rh-123 or the Argon laser separately did not show any decreased [3H]-thymidine uptake in oxygen, D2O or N2 environment. These results provide evidence of a photodynamic process since Rh-123 sensitization and Argon laser activation occur at nonthermal levels of energy and are oxygen dependent. The high effectiveness of this technique of photodynamic therapy with the Argon laser, and low toxicity of Rh-123 could make its clinical use very attractive for the treatment of superficial malignancies

  16. Laser-induced vibrational dynamics of ozone in solid argon

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Amstrup, B.; Henriksen, Niels Engholm

    1997-01-01

    We consider the vibrational dynamics, induced by an intense infrared laser pulse, in an ozone molecule with isotopic substitution, that is, (OOO)-O-16-O-16-O-18 and compare the dynamics in the gas phase and in solid ar on. not perturbed by argon on a time-scale of a few picoseconds and selective...

  17. Argon laser choroidotomy for drainage of subretinal fluid.

    Science.gov (United States)

    Bovino, J A; Marcus, D F; Nelsen, P T

    1985-03-01

    We used the argon laser to perforate the choroid and drain subretinal fluid during retinal detachment surgery in 24 consecutive patients. The procedure was successful in 23 of 24 patients (95.8%). The laser settings required for perforation ranged from 0.02 to 0.2 s and from 200 mW to 2.0 W. Because it is not necessary to enter the subretinal space with a solid, pointed object, laser choroidotomy may reduce the incidence of retinal perforation. In addition, the laser has the advantage of cauterizing small vessels during choroidal puncture, which may reduce bleeding at the time of drainage.

  18. Cleaning of diffusion bonding surface by argon ion bombardment treatment

    International Nuclear Information System (INIS)

    Wang, Airu; Ohashi, Osamu; Yamaguchi, Norio; Aoki, Masanori; Higashi, Yasuo; Hitomi, Nobuteru

    2003-01-01

    The specimens of oxygen-free high conductivity copper, SUS304L stainless steel and pure iron were treated by argon ion bombardment and then were bonded by diffusion bonding method. The effects of argon ion bombardment treatment on faying surface morphology, tensile strength of bonding joints and inclusions at the fracture surface were investigated. The results showed that argon ion bombardment treatment was effective to remove the oxide film and contamination at the faying surface and improve the quality of joints. The tensile strength of the bonded joints was improved, and minimum bonding temperature to make the metallic bonding at the interface was lowered by argon ion bombardment treatment. At the joints with argon ion bombardment treatment, ductile fractured surface was seen and the amount of inclusions was obviously decreased

  19. Laser-induced fluorescence measurements of argon ion velocities near the sheath boundary of an argon-xenon plasma

    International Nuclear Information System (INIS)

    Lee, Dongsoo; Severn, Greg; Oksuz, Lutfi; Hershkowitz, Noah

    2006-01-01

    The Bohm sheath criterion in single- and two-ion species plasma is studied with laser-induced fluorescence using a diode laser. Xenon is added to a low pressure unmagnetized dc hot filament argon discharge confined by surface multidipole magnetic fields. The Ar II transition at 668.614 nm is adopted for optical pumping to detect the fluorescence from the plasma and to measure the argon ion velocity distribution functions with respect to positions relative to a negatively biased boundary plate. The structures of the plasma sheath and presheath are measured by an emissive probe. The ion concentrations of the two-species in the bulk plasma are calculated from ion acoustic wave experiments. Results are compared with previous experiments of Ar-He plasmas in which the argon ions were the heavier ion species. Unlike the previous results, the argon speed is slower than its own Bohm velocity near the sheath-presheath boundary in the Ar-Xe plasma where argon ions are the lighter ion species. We argue that this result is consistent with the behaviour of the helium ion required by the generalized Bohm criterion in the previous experiments with Ar-He plasmas. Further, our results suggest that the measured argon ion speed approaches the ion sound speed of the system

  20. Effects of argon laser on atheromatous plaques. A preliminary study on post-mortem arterial specimens

    International Nuclear Information System (INIS)

    Pernes, J.M.; Angel, C.Y.; Brenot, P.; Bruneval, P.; Camilleri, J.P.; Gaux, J.C.

    1985-01-01

    The effects of argon laser radiation of human atheroma were studied in vitro. Lesions produced were craters from total tissue volatilization surrounded by a thin zone of coagulation. The degree of tissue destruction was related to the energy used and the direction of the laser beam in relation to the atheromatous stenotic lesion. These findings confirm that it is possible to destroy the atheroma under controlled conditions, but a the non-negligeable risk of perforation. By allowing visual control, the angioscope should ensure increased safety in use and provide hope for future applications of this method by the percutaneous route in the treatment of established atheromatous disease [fr

  1. Resonant excitation of uranium atoms by an argon ion laser

    Energy Technology Data Exchange (ETDEWEB)

    Maeyama, H; Morikawa, M; Aihara, Y; Mochizuki, T; Yamanaka, C [Osaka Univ. (Japan)

    1979-03-01

    Photoionization of uranium atoms by UV lines, 3511 A and 3345 A, of an argon ion laser was observed and attributed due to resonant two-photon ionization. The dependence of the photoion currents on laser power was measured in focusing and non-focusing modes of laser beam, which has enabled us to obtain an absorption cross section and an ionization cross section independently. The orders of magnitude of these cross sections averaged over the fine structure were determined to be 10/sup -14/ cm/sup 2/ and 10/sup -17/ cm/sup 2/ respectively from a rate equation model. Resonance between 3511-A laser line and the absorption line of uranium isotopes was also confirmed by the ionization spectra obtained by near-single-frequency operation of the ion laser, which allowed the isotopic selective excitation of the uranium atoms. The maximum value of the enrichment of /sup 235/U was about 14%. The isotope separation of uranium atoms by this resonant excitation has been discussed.

  2. Active iris vascular tufts bleeding successfully treated with argon laser photocoagulation.

    Science.gov (United States)

    Sarmad, Ambreen; Alfaqawi, Fadi; Chakrabarti, Monali; Mitra, Arijit; Mushtaq, Bushra

    2018-03-01

    Iris vascular tufts (IVT) are rare biomicroscopic capillary outgrowths from the pupillary margins. Patients are usually asymptomatic until presenting with blurred vision due to spontaneous hyphema or with raised intraocular pressure. A 61-year-old woman presented to eye casualty with left eye (LE) blurred vision and discomfort for 1 day. Her external ocular examination was unremarkable and visual acuity was 6/6 in the right eye (RE) and 6/9 in the LE. Biomicroscopic examination revealed a 2-mm hyphema in her LE and bilateral multiple small IVT and active bleeding from IVT at the pupillary margin of the LE at the 5 o'clock position. Diagnosis of LE active bleeding from IVT was made and she underwent argon laser photocoagulation directed at the source of bleeding. The bleeding stopped immediately after the second burn. She was followed up for 3 months; her visual acuity was 6/5 and 6/6 in the RE and LE, respectively, with no further problems. Iris vascular tufts are benign and recurrent hemorrhages are unlikely. Therefore, definitive argon laser photocoagulation or surgical treatment are reserved to arrest further episodes of hyphema. Our case demonstrates the effective use of argon laser photocoagulation to completely arrest active bleeding from IVT and excellent recovery of hyphema with no further problems for 5 years.

  3. Argon laser peripheral iridoplasty for angle-closure glaucoma in sibilings with weill-marchesani syndrome.

    Science.gov (United States)

    Ritch, R; Solomon, L D

    1992-01-01

    A patient with Weill-Marchesani syndrome and angle-closure glaucoma had persistent appositional closure after laser iridotomy that was unrelieved by topical application of either miotic or cycloplegic agents. Argon laser peripheral iridoplasty successfully opened the angle. The patient's sister also had Weill-Marchesani syndrome and angle closure unrelieved by laser iridotomy. Angle closure in Weill-Marchesani syndrome and the response to laser iridotomy and treatment with either miotic or cycloplegic agents may be complex and depends on the relative proportion of pupillary block as a mechanism underlying the angle closure, the functional status of the zonular apparatus, and the degree of angle crowding by the peripheral iris in the presence or absence of peripheral anterior synechiae.

  4. Calculation of high-pressure argon plasma parameters produced by excimer laser

    International Nuclear Information System (INIS)

    Tsuda, Norio; Yamada, Jun

    2000-01-01

    When a XeCl excimer laser light was focused in a high-pressure argon gas up to 150 atm, a dense plasma developed not only backward but also forward. It is important to study on the electron density and temperature of the laser-induced plasma in the high-pressure gas. The electron density and temperature in high-pressure argon plasma produced by XeCl excimer laser has been calculated and compared with the experimental data. (author)

  5. Laser surface processing with controlled nitrogen-argon concentration levels for regulated surface life time

    Science.gov (United States)

    Obeidi, M. Ahmed; McCarthy, E.; Brabazon, D.

    2018-03-01

    Laser surface modification can be used to enhance the mechanical properties of a material, such as hardness, toughness, fatigue strength, and corrosion resistance. Surface nitriding is a widely used thermochemical method of surface modification, in which nitrogen is introduced into a metal or other material at an elevated temperature within a furnace. It is used on parts where there is a need for increased wear resistance, corrosion resistance, fatigue life, and hardness. Laser nitriding is a novel method of nitriding where the surface is heated locally by a laser, either in an atmosphere of nitrogen or with a jet of nitrogen delivered to the laser heated site. It combines the benefits of laser modification with those of nitriding. Recent work on high toughness tool steel samples has shown promising results due to the increased nitrogen gas impingement onto the laser heated region. Increased surface activity and nitrogen adsorption was achieved which resulted in a deeper and harder surface compared to conventional hardening methods. In this work, the effects of the laser power, pulse repetition frequency, and overlap percentage on laser surface treatment of 316 L SST steel samples with an argon-nitrogen jet will be presented. Resulting microstructure, phase type, microhardness, and wear resistance are presented.

  6. Protective effect of basic fibroblast growth factor on retinal injury induced by argon laser photocoagulation

    International Nuclear Information System (INIS)

    Chen, P; San, Q; Wang, C Z; Yang, Z F; Kang, H X; Qian, H W; Zhang, C P

    2010-01-01

    Laser photocoagulation treatment is often complicated by a side effect of visual impairment, which is caused by the unavoidable laser-induced retinal destruction. At present no specific is found to cure this retinopathy. The aim of this study was to observe the neuroprotective effect of bFGF on laser-induced retinal injury. Chinchilla rabbits were divided into three groups and argon laser lesions were created in the retinas. Then bFGF or dexamethasone, a widely used ophthalmic preparation, or saline was given severally by retrobulbar injection. The retinal lesions were evaluated histologically and morphometrically, and visual function was examined by ERG. The results showed that bFGF administration better preserved morphology of retinal photoreceptors and significantly diminished the area of the lesions. Furthermore, bFGF promoted the restoration of the ERG b-wave amplitude. In rabbits treated with dexamethasone, however, the lesions showed almost no ameliorative changes. This is the first study to investigate the potential role of bFGF as a remedial agent in laser photocoagulation treatment. These findings suggest that bFGF has significant neuroprotective properties in the retina and this type of neuroprotection may be of clinical significance in reducing iatrogenic laser-induced retinal injuries in humans

  7. Effect of Argon Laser on Enamel Demineralization around Orthodontic Brackets: An In Vitro Study

    Science.gov (United States)

    Miresmaeili, Amirfarhang; Etrati Khosroshahi, Mohammad; Motahary, Pouya; Rezaei-Soufi, Loghman; Mahjub, Hossein; Dadashi, Maryam; Farhadian, Nasrin

    2014-01-01

    Objective This study was designed to evaluate the effect of argon laser irradiation on development and progress of enamel demineralization around orthodontic brackets. Materials and Methods: Fifty caries-free, intact human premolars were randomly assigned to one of the following five equal groups: Groups 1 (control) and 2: The brackets were bonded using conventional halogen light for 40s and argon laser for 10s, respectively. Teeth in group 3 were lased with argon laser for 10s before bracket bonding with halogen light. Group 4 was the same as group 3 except that brackets were also bonded with argon laser. In group 5 samples were bonded conventionally, immersed in an artificial caries solution for two days and then irradiated for 10s with argon laser. All samples were subjected to demineralization by artificial caries solution for 10 days. After bracket removal, samples were buccolingually sectioned and evaluated by polarized light microscopy. Decalcified lesion depth in each section was measured by a trained examiner in a blind fashion. Data were analyzed in SPSS 14 using one-way ANOVA and Tukey’s HSD post hoc test. Results: The control group showed the greatest mean lesion depth while group 5 revealed the lowest. The laser-treated groups had significantly lower mean lesion depth compared with the control group (Pbracket bonding can increase caries resistance of intact and demineralized enamel. PMID:25584052

  8. Relative efficacy of the argon green, argon blue-green, and krypton red lasers for 10-0 nylon subconjunctival laser suture lysis.

    Science.gov (United States)

    Mudgil, A V; To, K W; Balachandran, R M; Janigian, R H; Tsiaras, W G

    1999-01-01

    To determine the optimal wavelength for subconjunctival laser suture lysis. 130 black monofilament 10-0 nylon sutures were sewn subconjunctivally into the bare sclera of enucleated rabbit globes. The lowest energy levels facilitating laser suture lysis were determined for the argon green (514.5 NM), argon blue-green (488.0 NM, 514.5 NM), and krypton red (647.1 NM) wavelengths. In addition, absorption spectroscopy was performed on the suture material and conjunctiva using the Perkin Elmer W/VIS Lambda 2 spectrometer. Krypton red produced the fewest buttonhole defects, and it was also the most efficient energy source for suture lysis (P = 0.0001) under nontenectomized conjunctiva. Absorbance spectra studies revealed peak absorbance at 628 NM for the 10-0 nylon suture material. Based on animal and absorption spectroscopy studies, krypton red may be a safer and more efficient wavelength for subconjunctival laser suture lysis.

  9. Assessment of Sesame Oil as a Radioprotector against Some Biochemical Alterations Induced by Argon Laser on Albino Rat Head

    International Nuclear Information System (INIS)

    Omran, M.F.

    2007-01-01

    The plant (Sesamum indicum) is a lovely annual shrub with white bell-shaped flowers tinged with a hint of blue, red or yellow. The rich, almost odourless oil expressed from the tiny seeds is very stable and contains an antioxidant system comprising sesamol and sesamolinol formed from sesamolin, which substantially reduces its oxidation rate. The objective of this study was designed to evaluate the efficacy of sesame oil to reduce the altered biochemical indices in brain of irradiated rats exposed to argon laser at wavelength 488 nm. Methods: Animals were divided into 4 groups. Group 1: Control group where 6 rats are dissected as control for other irradiated rats. Group 2: Irradiated with argon laser at wavelength 488 nm receiving energy (1.0 J x 3 times) on head of rats day by day. Group 3: Animals administered with sesame oil 500 mg/kg body wt/day for 20 successive days. Group 4: Irradiated with argon laser at wavelength 488 nm receiving an energy (1.0 J x 3 times) animals administered with sesame oil 500 mg/kg body wt/day through the radiation. Each group was dissected after 1, 9 and 14 days after exposure to laser radiation (presented in NCRRT). Results: The use of naturally occurring agents as antioxidant agents as sesame oil can slow the degenerative process in several neuro degenerative diseases. These data are addition to the antioxidant properties of the sesame oil against argon laser at wavelength 488 nm to indicate a possible role for the use in treatment of diseases involving free radicals and oxidative damage

  10. CW gain measurements in small-bore argon-ion laser discharges using a novel modulation technique

    International Nuclear Information System (INIS)

    Bennett, W.R. Jr.; Sze, R.C.

    1974-01-01

    A technique for small-signal gain measurements for cw laser systems is described. The method is applied to the measurement of multimode small-signal gain coefficients of small-bone argon-ion laser transitions. (U.S.)

  11. Non-linear behaviour of power density and exposure time of argon laser on ocular tissues

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed, E M; Talaat, M S; Salem, E F [Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt)

    1997-12-31

    In ophthalmology, the thermal effect of argon laser is the most widely used category of laser- tissue interaction. The rise in tissue temperature has to exceed a threshold value for photo coagulation of retinal blood vessels. This value mainly depends on the laser. The most suitable argon laser power P and exposure time (t) which would be more effective for thermal and electrical behaviour of chicken eye was studied. This was achieved by measuring the variations in ocular temperature in electroretinogram (ERG) records under the effect of argon experiment, while power density (P) and exposure time (t) were varied in four different ways for each dose (pt). Results indicated that for the same laser dose, the temperature distribution of the eye, using low power density and high exposure time was higher than that high power density and low exposure time, indicating non-linearity of the laser dose. This finding was confirmed by ERG records which showed similar variations in b-wave latency, amplitude and duration, for the laser exposure conditions. This indicates variations in retinal function due to laser-dependent temperature variations. 5 figs., 3 tabs.

  12. Laser light scattering in a laser-induced argon plasma: Investigations of the shock wave

    Energy Technology Data Exchange (ETDEWEB)

    Pokrzywka, B. [Obserwatorium Astronomiczne na Suhorze, Uniwersytet Pedagogiczny, ulica Podchorazych 2, 30-084 Krakow (Poland); Mendys, A., E-mail: agata.mendys@uj.edu.pl [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagiellonski, ulica Reymonta 4, 30-059 Krakow (Poland); Dzierzega, K.; Grabiec, M. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagiellonski, ulica Reymonta 4, 30-059 Krakow (Poland); Pellerin, S. [GREMI, site de Bourges, Universite d' Orleans, CNRS, rue Gaston Berger BP 4043, 18028 Bourges (France)

    2012-08-15

    Shock wave produced by a laser induced spark in argon at atmospheric pressure was examined using Rayleigh and Thomson scattering. The spark was generated by focusing a laser pulse from the second harmonic ({lambda} = 532 nm) of a nanosecond Nd:YAG laser using an 80 mm focal length lens, with a fluence of 2 kJ{center_dot}cm{sup -2}. Images of the spark emission were recorded for times between 30 ns and 100 {mu}s after the laser pulse in order to characterize its spatial evolution. The position of the shock wave at several instants of its evolution and for several plasma regions was determined from the Rayleigh-scattered light of another nanosecond Nd:YAG laser (532 nm, 40 J{center_dot}cm{sup -2} fluence). Simultaneously, Thomson scattering technique was applied to determine the electron density and temperature in the hot plasma core. Attempts were made to describe the temporal evolution of the shock wave within a self-similar model, both by the simple Sedov-Taylor formula as well as its extension deduced by de Izarra. The temporal radial evolution of the shock position is similar to that obtained within theory taking into account the counter pressure of the ambient gas. Density profiles just behind the shock front are in qualitative agreement with those obtained by numerically solving the Euler equations for instantaneous explosion at a point with counter pressure. - Highlights: Black-Right-Pointing-Pointer We investigated shock wave evolution by Rayleigh scattering method. Black-Right-Pointing-Pointer 2D map of shockwave position for several times after plasma generation is presented. Black-Right-Pointing-Pointer Shock wave evolution is not satisfactorily described within self-similar models. Black-Right-Pointing-Pointer Evolution of shock position similar to theory taking into account counter pressure. Black-Right-Pointing-Pointer Density profile behind the shock similar to numerical solution of Euler equations.

  13. Tensile strength of laser welded cobalt-chromium alloy with and without an argon atmosphere.

    Science.gov (United States)

    Tartari, Anna; Clark, Robert K F; Juszczyk, Andrzej S; Radford, David R

    2010-06-01

    The tensile strength and depth of weld of two cobalt chromium alloys before and after laser welding with and without an argon gas atmosphere were investigated. Using two cobalt chromium alloys, rod shaped specimens (5 cm x 1.5 mm) were cast. Specimens were sand blasted, sectioned and welded with a pulsed Nd: YAG laser welding machine and tested in tension using an Instron universal testing machine. A statistically significant difference in tensile strength was observed between the two alloys. The tensile strength of specimens following laser welding was significantly less than the unwelded controls. Scanning electron microscopy showed that the micro-structure of the cast alloy was altered in the region of the weld. No statistically significant difference was found between specimens welded with or without an argon atmosphere.

  14. XUV radiation from gaseous nitrogen and argon target laser plasmas

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Vrbová, M.; Brůža, P.; Pánek, D.; Krejčí, F.; Kroupa, M.; Jakůbek, J.

    2012-01-01

    Roč. 370, č. 1 (2012), s. 012049 ISSN 1742-6588. [Latin American Workshop on Plasma Physics (LAWPP 2011)/14/. Mar del Plata, 20.11.2011-25.11.2011] R&D Projects: GA MŠk LA08024; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : Laser plasma source of XUV radiation in water window range * RHMD Z* engine code Subject RIV: BH - Optics, Masers, Lasers http://iopscience.iop.org/1742-6596/370/1/012049/pdf/1742-6596_370_1_012049.pdf

  15. Reparative processes of the iris after irradiation with the argon-ion laser

    International Nuclear Information System (INIS)

    Huber, G.K.; Zypen, E. van der; Fankhauser, F.

    1979-01-01

    The reparative processes of the pigmented iris of the rabbit were analysed with ultrastructural methods. Clearing of the damaged area by macrophages is the first step in the reparative processes. Clump cells are macrophages which are observed from the first day of the injury until the ninth week. Repair of the anterior surface of the iris is largely finished after 32 days. The repair of collagenous fibres reaches its maximum activity 32 days after irradiation. The pigment epithelium has only an insignificant regeneration potential. Irradiation of the iris by the argon-ion laser results in an atropic, hyperpigmented scar. The rapid regeneration of a lesion induced by the argon-ion laser in the rabbit iris casts doubt as to whether this method could be applied to the human eye with equal success. (orig.) 891 AJ/orig. 892 MB

  16. cw argon laser annealing of anodic oxide on GaAs

    International Nuclear Information System (INIS)

    Chakravarti, S.N.; Das, P.; Webster, R.T.; Bhat, K.N.

    1981-01-01

    Anodic oxide films (850 +- 50 A thick) grown on n + (100) bulk GaAs were subjected to selective area annealing using a cw argon laser operating at an output power of 1.2 W. Capacitance-voltage (C-V) measurements performed on Al-anodic oxide-GaAs MOS capacitor structures show that laser-annealed capacitor dots have greatly reduced field-induced hysteresis effects in their capacitance-voltage characteristics compared to the unannealed ones. The oxide leakage current also shows a significant improvement: the leakage current magnitude of MOS capacitors in laser-annealed oxide island is over four orders of magnitude less than the oxide region which was not exposed to the laser radiation. Dielectric breakdown measurement indicates that laser-annealed capacitors have considerably higher breakdown voltages, about a factor of 2 higher than the unannealed capacitors

  17. Spectral blueshifts in laser light scattered from argon-gas-cluster plasmas

    International Nuclear Information System (INIS)

    Singhal, H.; Arora, V.; Naik, P.A.; Gupta, P.D.

    2005-01-01

    An experimental study is presented on scattering of laser light from argon gas clusters irradiated by multipicosecond Nd:glass laser pulses at moderate intensity of 10 15 W/cm 2 . Space-resolved side-scattered laser light has a predominantly blueshifted and broadened spectrum (up to ∼8 nm). The scattered signal intensity and average blueshift exhibit a marked dependence on the backing pressure of the gas. The results are explained by self-phase modulation of the laser radiation due to changing polarizability as the heated clusters pass through resonance at 3 times the critical density during which intense absorption and scattering occurs. The observed blueshift may be useful in diagnostics of this important phase of laser-cluster interactions

  18. Results of laser treatment for sub-retinal neovascular membranes ...

    African Journals Online (AJOL)

    A retrospective study was carried out to determine the results of laser treatment for choroidal neovascular membranes in age-related macular degeneration in 92 patients in whom fluorescein angiography was performed for this condition over a 7-year period. Twenty-nine of these patients, treated with the argon laser, were ...

  19. Effect of laser peripheral iridotomy using argon and neodymium-YAG lasers on corneal endothelial cell density: 7-year longitudinal evaluation.

    Science.gov (United States)

    Ono, Takashi; Iida, Masaharu; Sakisaka, Toshihiro; Minami, Keiichiro; Miyata, Kazunori

    2018-03-01

    To evaluate the changes in corneal endothelial cell density (ECD) over a 7-year period after laser peripheral iridotomy (LPI) using argon and neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers. Retrospective case series. Eyes that underwent prophylactic LPI using argon and Nd:YAG lasers were followed up for 7 years. Central corneal endothelial cells were observed by use of noncontact specular microscopy preoperatively and at 1 and 7 years postoperatively. Changes in ECD and the associations between preoperative ECD and the total energy of the Nd:YAG laser were evaluated. Fifty-one eyes of 51 patients were followed up for 7 years. The ECD significantly decreased after LPI (P laser energy. Long-term evaluation indicated that the reduction in ECD after argon-Nd:YAG laser LPI was present but small during the initial year and was negligible after 1 year.

  20. Argon laser iridoplasty : A primary mode of therapy in primary angle closure glaucoma

    Directory of Open Access Journals (Sweden)

    Agarwal H

    1991-01-01

    Full Text Available Argon laser iridoplasty was performed in 40 eyes of 33 patients of primary angle closure glaucoma. There were 12 male and 21 female patients. The mean ages of the male and female patients were 51 years and 48.4 years respectively. Forty eyes were divided into two groups. Group I consisted of ten eyes of subacute angle closure glaucoma and group II included thirty eyes of chronic angle closure glaucoma. Argon laser iridoplasty was performed with Coherent 9000 model using laser settings of spot size 200 micron, duration 0.2 second and power 0.7 watt. A total of 80 spots were applied over 360 degree circumference. The intraocular pressure control (below 22 mm Hg was achieved after iridoplasty in all the eyes (100% in group I, where as in group II the intraocular pressure was controlled in 70% eyes. The follow up period varied from 3 months to one year with a mean of eight months. The success rate with iridoplasty was directly related to the extent of peripheral anterior synechiae, optic disc cupping and presence of visual field changes.

  1. Laser-induced surface modification of metals and alloys in liquid argon medium

    International Nuclear Information System (INIS)

    Kazakevich, V S; Kazakevich, P V; Yaresko, P S; Kamynina, D A

    2016-01-01

    Micro and nanostructuring of metals and alloys surfaces (Ti, Mo, Ni, T30K4) was considered by subnanocosecond laser radiation in stationary and dynamic mode in the liquid argon, ethanol and air. Depending of structures size on the samples surface from the energy density and the number of pulses were built. Non-periodic (NSS) and periodic (PSS) surface structures with periods about λ-λ/2 were obtained. PSS formation took place as at the target surface so at the NSS surface. (paper)

  2. Production of highly charged ions of argon by optical field ionization in a relativistic laser field

    International Nuclear Information System (INIS)

    Sagisaka, Akito; Akahane, Yutaka; Aoyama, Makoto; Nakano, Fumihiko; Yamakawa, Koichi

    2001-01-01

    We observed the highly charged ions of argon by optical field ionization in a relativistic intensity regime. Charge states up to Ar 15+ were produced at the highest intensity of 800 nm, linearly polarized 20 fs Ti: sapphire laser pulses. The peak intensity of the pulse is determined by comparing the measured ion production curve for Ar 9+ with ADK theory. The results of these measurements of the ionization indicate that the maximum peak intensity is achieved to ∼2x10 19 W/cm 2 . (author)

  3. Argon laser-induced damage in the goldfish (C. auratus) retina following whole-body hyperthermia

    Science.gov (United States)

    Deaton, Michael A.; Lund, David J.; Schuschereba, Steven T.; Dahlberg, Ann M.; Cowan, Beth L.; Lester, Paul; Odom, Daniel G.

    1990-07-01

    The heat shock response is a phenomenon common to all cells and is characterized by an increase in the rate of synthesis of intracellular heat shock proteins (HSPs) . The response occurs following rapid transient increases in terrerature sufficient to cause stress but not cell death. HSPs appear to perform protective functions that raise the cell''s tolerance to diverse noxious stimuli. Thus we postulated that we could limit laser-induced retinal darriage through induction of the heat shock -response. Corrmon goldfish (C. auratus) made hyperthermic by immersion in 35C water for 15 minutes and radiolabeled with [355]methionine showed retinal liSPs with apparent molecular weights of 110 90 70 and 35 kilodaltons. To test the protective effects of HSPs against laser injury goldfish were made hyperthermic and 4 and 24 hr later their retinas were irradiated with argon laser light (51 4 . 5 nm spot size at the cornea 3. 0 mm irradiance 125 mW/cm2) . NonhyperLhermic animals served as controls. Following 24 hr of recovery fish were terminated and retinas fixed for histology. Fundus photographs were taken irrunediately after laser exposure . Lesion diameters were measured from fundus photographs and evaluated statistically. The mean retinal lesion diameters of fish not subjected to hyperthermJ. a laser exposed 4 hr post hyperLhermia and laser exposed 24 hr post hyperthermia were 10. 25 1. 4 SD 8. 82 2. 1 SD and 6. 78

  4. Volume Measurements of Laser-generated Pits for In Situ Geochronology using KArLE (Potassium-Argon Laser Experiment)

    Science.gov (United States)

    French, R. A.; Cohen, B. A.; Miller, J. S.

    2014-01-01

    The Potassium-Argon Laser Experiment( KArLE), is composed of two main instruments: a spectrometer as part of the Laser-Induced Breakdown Spectroscopy (LIBS) method and a Mass Spectrometer (MS). The LIBS laser ablates a sample and creates a plasma cloud, generating a pit in the sample. The LIBS plasma is measured for K abundance in weight percent and the released gas is measured using the MS, which calculates Ar abundance in mols. To relate the K and Ar measurements, total mass of the ablated sample is needed but can be difficult to directly measure. Instead, density and volume are used to calculate mass, where density is calculated based on the elemental composition of the rock (from the emission spectrum) and volume is determined by pit morphology. This study aims to reduce the uncertainty for KArLE by analyzing pit volume relationships in several analog materials and comparing methods of pit volume measurements and their associated uncertainties.

  5. Demonstration of a neonlike argon soft-x-ray laser with a picosecond-laser-irradiated gas puff target.

    Science.gov (United States)

    Fiedorowicz, H; Bartnik, A; Dunn, J; Smith, R F; Hunter, J; Nilsen, J; Osterheld, A L; Shlyaptsev, V N

    2001-09-15

    We demonstrate a neonlike argon-ion x-ray laser, using a short-pulse laser-irradiated gas puff target. The gas puff target was formed by pulsed injection of gas from a high-pressure solenoid valve through a nozzle in the form of a narrow slit and irradiated with a combination of long, 600-ps and short, 6-ps high-power laser pulses with a total of 10 J of energy in a traveling-wave excitation scheme. Lasing was observed on the 3p (1)S(0)?3s (1)P(1) transition at 46.9 nm and the 3d (1)P(1)?3p (1)P(1) transition at 45.1 nm. A gain of 11 cm(-1) was measured on these transitions for targets up to 0.9 cm long.

  6. The Potassium-Argon Laser Experiment (KArLE): In Situ Geochronology for Planetary Robotic Missions

    Science.gov (United States)

    Cohen, Barbara

    2016-01-01

    The Potassium (K) - Argon (Ar) Laser Experiment (KArLE) will make in situ noble-gas geochronology measurements aboard planetary robotic landers and roverss. Laser-Induced Breakdown Spectroscopy (LIBS) is used to measure the K abun-dance in a sample and to release its noble gases; the evolved Ar is measured by mass spectrometry (MS); and rela-tive K content is related to absolute Ar abundance by sample mass, determined by optical measurement of the ablated volume. KArLE measures a whole-rock K-Ar age to 10% or better for rocks 2 Ga or older, sufficient to resolve the absolute age of many planetary samples. The LIBS-MS approach is attractive because the analytical components have been flight proven, do not require further technical development, and provide complementary measurements as well as in situ geochronology.

  7. Fluorescein angiography and changes in aqueous humor protein after argon laser photomydriasis in rabbits

    International Nuclear Information System (INIS)

    Denffer, H. v.; Erhardt, W.; Neiss, A.

    1979-01-01

    In brown-eyed and blue-eyed rabbits, irises treated with argon laser photomydriasis (ALP) were studied by using fluorescein angiography and by evaluating the aqueous humor protein concentration. The following results were obtained. Immediately after ALP, a breakdown of the blood-aqueous barrier is demonstrated by a marked influx of fluorescein into the ciliary processes and into the anterior and posterior chambers. The dye flow into the aqueous humor decreases to normal values within 3 days. There is no fluorescein leakage from laser impacts themselves. Peripupillary capillary loops are permanently occluded, but in a few cases, recanalization occurs. Neovascularization did not occur during 56 days of observation. ALP initially leads to a six- to eightfold increase in normal aqueous humor protein concentration, which returns to normal values within 3 days. (orig./AJ) 891 AJ/orig.- 892 MKO [de

  8. Argon plasma treatment to enhance the electrochemical reactivity of screen-printed carbon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ghamouss, F.; Luais, E. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France); Universite de Nantes, Institut des Materiaux Jean Rouxel IMN - CNRS, 2 rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 3 (France); Thobie-Gautier, C. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France); Tessier, P.-Y. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France); Universite de Nantes, Institut des Materiaux Jean Rouxel IMN - CNRS, 2 rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 3 (France); Boujtita, M. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France)], E-mail: mohammed.boujtita@univ-nantes.fr

    2009-04-15

    Radiofrequency argon plasma was used for screen-printed carbon electrodes (SPCE) surface treatment. The cyclic voltammetry of ferri/ferrocyanide as redox couple showed a remarkable improvement of the electrochemical reactivity of the SPCE after the plasma treatment. The effect of the plasma growth conditions on the efficiency of the treatment procedure was evaluated in term of electrochemical reactivity of the SPCE surface. The electrochemical study showed that the electrochemical reactivity of the treated electrodes was strongly dependant on radiofrequency power, treatment time and argon gas pressure. X-ray photoelectron spectroscopy (XPS) analysis showed a considerable evolution on the surface chemistry of the treated electrodes. Our results clearly showed that the argon plasma treatment induces a significant increase in the C{sub sp2}/C{sub sp3} ratio. The scanning electron micrograph (SEM) also showed a drastic change on the surface morphology of the treated SPCEs.

  9. Skinning of argon clusters by Coulomb explosion induced with an intense femtosecond laser pulse

    International Nuclear Information System (INIS)

    Sakabe, S.; Shirai, K.; Hashida, M.; Shimizu, S.; Masuno, S.

    2006-01-01

    The energy distributions of ions emitted from argon clusters Coulomb exploded at an intensity of 17 W/cm 2 with an intense femtosecond laser have been experimentally studied. The power m of energy E of the ion energy distribution (dN/dE∼E m ) is expected to be 1/2 for spherical ion clusters, but it is in fact reduced smaller than 1/2 as the laser intensity is decreased. This reduction can be well interpreted as resulting from the instantaneous ionization of the surface of the cluster. The validity of this interpretation was confirmed by experiments with double pulse irradiation. A cluster irradiated by the first pulse survives as a skinned cluster, and the remaining core part is Coulomb exploded by the second pulse. It is shown that a cluster can be skinned by an intense short laser pulse, and the laser-intensity dependence of the skinned layer thickness can be reasonably explained by the laser-induced space charge field created in the cluster

  10. Argon laser peripheral iridoplasty versus systemic intraocular pressure-lowering medications as immediate management for acute phacomorphic angle closure

    Directory of Open Access Journals (Sweden)

    Lee JW

    2013-01-01

    Full Text Available Jacky WY Lee,1 Jimmy SM Lai,1 Doris WF Yick,2 Can YF Yuen21Department of Ophthalmology, University of Hong Kong, 2Department of Ophthalmology, The Caritas Medical Centre, Kowloon West Cluster, Hong Kong, People’s Republic of ChinaBackground: The purpose of this study was to compare the efficacy and safety of argon laser peripheral iridoplasty (ALPI and systemic intraocular pressure (IOP-lowering medications in the immediate management of acute phacomorphic angle closure.Methods: Consecutive cases of acute phacomorphic angle closure were randomized to receive ALPI and an intravenous or oral carbonic anhydrase inhibitor as initial treatment. Intravenous mannitol was administered for presenting IOP > 60 mmHg or IOP > 40 mmHg 2 hours posttreatment in both arms.Results: Of 10 consecutive cases, six received medical therapy and four received ALPI. Fifty percent in the medical group and none in the ALPI group required intravenous mannitol. The ALPI group took less time to achieve IOP < 25 mmHg (18.8 ± 7.5 minutes versus 115.0 ± 97.0 minutes, P = 0.001, F test; had a greater IOP reduction within 30 minutes (69.8% ± 7.7% versus 40.9 ± 23.9%, P = 0.03, t-test; and had a consistently smaller post-attack cup to disc ratio (0.50 ± 0.02 versus 0.60 ± 0.20, P = 0.002, F test.Conclusion: ALPI offers greater safety, consistency, and efficacy than systemic IOP-lowering medications as initial treatment for phacomorphic angle closure.Keywords: phacomorphic, glaucoma, argon laser peripheral iridoplasty, medical, intraocular pressure

  11. Laser treatment of cutaneous angiokeratomas: A systematic review.

    Science.gov (United States)

    Nguyen, Jannett; Chapman, Lance W; Korta, Dorota Z; Zachary, Christopher B

    2017-11-01

    Angiokeratomas can present therapeutic challenges, especially in cases of extensive lesions, where traditional surgical methods carry high risks of scarring and hemorrhage. Argon, pulsed dye (PDL), neodymium-doped yttrium aluminum garnet (Nd:YAG), copper vapor, potassium titanyl phosphate, carbon dioxide, and erbium-doped yttrium aluminum garnet (Er:YAG) lasers have emerged as alternative options. To review the use and efficacy of lasers in treating angiokeratomas. A PubMed search identified randomized clinical trials, cohort studies, case series, and case reports involving laser treatment of cutaneous angiokeratomas. Twenty-five studies were included. Quality ratings were assigned using the Oxford Centre for Evidence-Based Medicine scheme. Several laser modalities are effective in treating multiple variants of angiokeratomas. Vascular lasers like PDL, Nd:YAG, and argon are the most studied and of these, PDL offers the safest side effect profile. Nd:YAG may be more effective for hyperkeratotic angiokeratomas. Combination treatment with multiple laser modalities has also demonstrated some success. Lasers are a promising treatment option for angiokeratomas, but current use is limited by the lack of treatment guidelines. There are limited high quality studies comparing laser treatments to each other and to non-laser options. Additional studies are needed to establish guidelines and to optimize laser parameters. © 2017 Wiley Periodicals, Inc.

  12. Clinicopathologic correlation of argon laser photocoagulation of retinal angiomas in a patient with von Hippel-Lindau disease followed for more than 20 years.

    Science.gov (United States)

    Rosa, R H; Goldberg, M F; Green, W R

    1996-01-01

    The authors review the histopathologic findings in the eyes of a patient with multiple retinal angiomas and von Hippel-Lindau disease, who underwent treatment with argon laser photocoagulation with follow-up of more than 20 years. The patient was studied ophthalmoscopically and by fluorescein angiography before and after argon laser photocoagulation of retinal angiomas. The eyes were obtained postmortem, and the central portion of the right eye, including the macula and optic nerve head, was sectioned serially for light microscopy. The pupil-optic nerve segment of the left eye was step-sectioned serially for light microscopy. Histopathologic study of the right eye disclosed mild cystoid macular edema and focal areas of exudation in the midperiphery possibly secondary to irradiation of the head. A 1.5 x 0.3-mm area of residual angioma was present in the nasal peripapillary retina. Superotemporally, four chorioretinal scars were present in one photocoagulated area. These scars were composed of dense fibrous tissue with vascularization and variable retinal pigment epithelium hyperplasia. Large, nonangiomatous vessels within each of the scars were continuous with other retinal vessels. Inferotemporally, two chorioretinal scars were present in one photocoagulated area. Histopathologically, these scars were similar to the superotemporal scars, except that no patent retinal vessels traversed the inferotemporal scars. Neovascularization of the retina was associated with one superotemporal and one inferotemporal scar. No residual angiomatous tissue was present in the supero- or inferotemporal areas. Histopathologic examination of the left eye disclosed extensive vitreous organization and periretinal fibrovascular proliferation, extensive gliosis of the retina, and a 4.5 x 2-mm schisis cavity filled with fibrinous exudate. Three angiomas with variable fibrosis were present in the left eye. Despite a poor clinical course in one eye treated with xenon arc photocoagulation

  13. Energy loss of argon in a laser-generated carbon plasma.

    Science.gov (United States)

    Frank, A; Blazević, A; Grande, P L; Harres, K; Hessling, T; Hoffmann, D H H; Knobloch-Maas, R; Kuznetsov, P G; Nürnberg, F; Pelka, A; Schaumann, G; Schiwietz, G; Schökel, A; Schollmeier, M; Schumacher, D; Schütrumpf, J; Vatulin, V V; Vinokurov, O A; Roth, M

    2010-02-01

    The experimental data presented in this paper address the energy loss determination for argon at 4 MeV/u projectile energy in laser-generated carbon plasma covering a huge parameter range in density and temperature. Furthermore, a consistent theoretical description of the projectile charge state evolution via a Monte Carlo code is combined with an improved version of the CasP code that allows us to calculate the contributions to the stopping power of bound and free electrons for each projectile charge state. This approach gets rid of any effective charge description of the stopping power. Comparison of experimental data and theoretical results allows us to judge the influence of different plasma parameters.

  14. Assessment of argon ion laser dispersive Raman spectroscopy for hot cell applications

    International Nuclear Information System (INIS)

    Crawford, B.A.

    1995-01-01

    Characterization of high-level waste tank materials at Hanford is conducted to support safety assessments and waste treatment activities. Raman spectroscopy is expected to give chemical species information which may assist in defining layering in tank waste. This report describes the dispersive Raman system used in this year's investigation and the methology used to collect and evaluate data taken on tank waste samples. The current argon-ion Raman system was found not to be suitable for screening of tank cores, owing to silica interference, fluorescence interferences, and the extensive time required to collect and treat the data. Recommendations are given for further development

  15. Dynamics of ZnO laser produced plasma in high pressure argon

    International Nuclear Information System (INIS)

    Kaydashev, V.E.; Lunney, J.G.

    2011-01-01

    Pulsed laser deposition of ZnO in high pressure gas offers a route for the catalyst-free preparation of ZnO nanorods less than 10 nm in diameter. This paper describes the results of some experiments to investigate the laser plume dynamics in the high gas pressure (5 x 10 3 -10 4 Pa) regime used for PLD of ZnO nanorods. In this regime the ablation plume is strongly coupled to the gas and the plume expansion is brought to a halt within about 1 cm from the target. A 248 nm excimer laser was used to ablate a ceramic ZnO target in various pressures of argon. Time- and space-resolved UV/vis emission spectroscopy and Langmuir probe measurements were used to diagnose the plasma and follow the plume dynamics. By measuring the spatial profiles of Zn I and Zn II spectral lines it was possible to follow the propagation of the external and internal shock waves associated with the interaction of the ablation plume with the gas. The Langmuir probe measurements showed that the electron density was 10 9 -10 10 cm -3 and the electron temperature was several eV. At these conditions the ionization equilibrium is described by the collisional-radiative model. The plume dynamics was also studied for ZnO targets doped with elements which are lighter (Mg), comparable to (Ga), and heavier (Er) than Zn, to see if there is any elemental segregation in the plume.

  16. In vivo argon laser vascular welding using thermal feedback: open and closed loop patency and collagen crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Small, W., LLNL

    1997-02-28

    An in vivo study of vascular welding with a fiber-delivered argon laser was conducted using a canine model. Longitudinal arteriotomies and venotomies were treated on femoral vein and artery. Laser energy was delivered to the vessel wall via a 400 {micro}m optical fiber. The surface temperature at the center of the laser spot was monitored in real time using a hollow glass optical fiber-based two-color infrared thermometer. The surface temperature was limited by either a room-temperature saline drip or direct feedback control of the laser using a mechanical shutter to alternately pass and block the laser. Acute patency was evaluated either visually (leak/no leak) or by in vivo burst pressure measurements. Biochemical assays were performed to investigate the possible laser-induced formation or destruction of enzymatically mediated covalent crosslinks between collagen molecules. Viable welds were created both with and without the use of feedback control. Tissues maintained at 50 C using feedback control had an elevated crosslink count compared to controls, while those irradiated without feedback control experienced a decrease. Differences between the volumetric heating associated with open and closed loop protocols may account for the different effects on collagen crosslinks. Covalent mechanisms may play a role in argon laser vascular fusion.

  17. Mechanism of the immobilization of surfactants on polymeric surfaces by means of an argon plasma treatment: Influence of UV radiation

    NARCIS (Netherlands)

    Lens, J.P.; Spaay, B.; Terlingen, J.G.A.; Engbers, G.H.M.; Feijen, Jan

    1999-01-01

    The mechanism of the immobilization of the surfactant sodium 10-undecenoate (C11(:)) on poly(ethylene) (PE) by means of an argon plasma treatment has been investigated. In particular, the influence of the vacuum ultraviolet (UV) radiation emitted by the argon plasma on the immobilization was

  18. Excited argon 1s5 production in micro-hollow cathode discharges for use as potential rare gas laser sources

    Science.gov (United States)

    Peterson, Richard D.; Eshel, Ben; Rice, Christopher A.; Perram, Glen P.

    2018-02-01

    The diode-pumped rare gas laser (DPRGL) has been suggested as a potential high-gain, high-energy laser which requires densities on the order of 1013 cm-3 at pressures around 1 atmosphere for efficient operation. Argon 1s5 number densities have been measured in micro-hollow cathode discharges with electrode gaps of 127 and 254 μm and hole diameters from 100-400 μm. The dependency of the metastable argon (1s5) density on total gas pressure, electrode gap distance and hole diameter were explored. The measured densities were all in the range of 0.5 - 2 × 1013 cm-3 with the 400 μm hole diameters being the lowest.

  19. The Advanced Glaucoma Intervention Study (AGIS): 11. Risk factors for failure of trabeculectomy and argon laser trabeculoplasty.

    Science.gov (United States)

    2002-10-01

    To investigate the association of pre-intervention and post-intervention patient and eye characteristics with failure of argon laser trabeculoplasty (ALT) and trabeculectomy. Cohort study of participants in the Advanced Glaucoma Intervention Study. This multicenter study took place between 1988 and 2001. Between 1988 and 1992, 789 eyes of 591 patients aged 35 to 80 years with advanced glaucoma were randomized into one of two surgical treatment sequences: argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy or trabeculectomy-ALT-trabeculectomy. Upon study-defined failure (based on maximum medications, sustained intraocular pressure (IOP) elevation, visual field defect, and disk rim deterioration) of each intervention, patients were offered the subsequent intervention. Potential follow-up was 8 to 13 years. This report is based on data from 779 eyes that had at least 3 months of follow-up. The main outcome measures are failure of ALT and trabeculectomy, whether as first or second interventions. Effect size is measured by the hazard ratio (HR) and its corresponding 95% confidence interval (CI) obtained from Cox multiple regression analysis, where HR corresponds to the coefficient of change in risk associated with a unit increase in a factor. For binary factors, this corresponds to the change in risk in eyes with the factor relative to the risk in eyes without the factor. Pre-intervention factors associated with failure of ALT are younger age (HR = 0.98, CI = 0.96-0.99, P =.009) and higher IOP (1.11, 1.08-1.15, P <.001). Pre-intervention factors associated with failure of trabeculectomy are younger age (HR = 0.97, CI = 0.95-0.99, P =.005) and higher IOP (1.04, 1.01-1.06, P =.002), as well as diabetes (2.86, 1.88-4.36, P <.001) and any postoperative complication (1.99, 1.35-2.93, P <.001). Individual postoperative complications significantly associated with increased risk of failure of trabeculectomy are elevated IOP (3.4, 1.9-6.1, P <.001) and marked

  20. Influence of argon plasma treatment on polyethersulphone surface

    Indian Academy of Sciences (India)

    2013-01-09

    Jan 9, 2013 ... waste water treatment from heavy and toxic metals, low-level nuclear waste management and separation of Zr from ... solid surface permits a rapid and qualitative evaluation of the SFE of the polymer. The water contact angle ...

  1. Comparison of indium 111 oxine-labeled platelet aggregation between sutured and argon laser-assisted vascular anastomoses

    International Nuclear Information System (INIS)

    Fujitani, R.M.; White, R.A.; Kopchok, G.E.; Vlasak, J.; Marcus, C.S.; White, G.H.

    1988-01-01

    The thrombogenicity of argon laser-assisted vascular anastomoses (LAVAs) was compared with that of sutured vascular anastomoses (SVAs) by measurement of platelet aggregation at the site of repair in a canine model. Sequential 1 cm longitudinal carotid and femoral arteriotomies (n = 80) or jugular and femoral phlebotomies (n = 80) were performed, with each vessel having two tandem, randomly positioned arteriotomies or phlebotomies separated by a 4 cm length of intact vessel. One incision was repaired by SVA with continuous 6-0 polypropylene sutures and the other by argon LAVA. For the laser fusions, argon laser energy was applied to the adventitial surface of the vessel with a 300 micron fiberoptic probe with 0.5 W power, 1100 joules per square centimeter energy fluence, and 150 second exposure per 1 cm length. The arterial and venous segments of SVAs and LAVAs and an equivalent length of normal vessel were harvested at 48 hours (n = 16, 16, 16), 2 weeks (n = 12, 12, 12), and 4 weeks (n = 12, 12, 12). Autologous indium 111 oxine-labeled platelets were injected intravenously 48 hours before removal of the vascular repairs and the radioactivity of the specimens was determined on removal with a NaI (T1) well-type scintillation counter. Anastomotic platelet adherence index (APAI) was calculated as the ratio of emissions of SVA or LAVA to normal reference vessel

  2. Development of the Potassium-Argon Laser Experiment (KArLE) Instrument for In Situ Geochronology

    Science.gov (United States)

    Cohen, Barbara A.; Li, Z.-H.; Miller, J. S.; Brinckerhoff, W. B.; Clegg, S. M.; Mahaffy, P. R.; Swindle, T. D.; Wiens, R. C.

    2012-01-01

    Absolute dating of planetary samples is an essential tool to establish the chronology of geological events, including crystallization history, magmatic evolution, and alteration. Traditionally, geochronology has only been accomplishable on samples from dedicated sample return missions or meteorites. The capability for in situ geochronology is highly desired, because it will allow one-way planetary missions to perform dating of large numbers of samples. The success of an in situ geochronology package will not only yield data on absolute ages, but can also complement sample return missions by identifying the most interesting rocks to cache and/or return to Earth. In situ dating instruments have been proposed, but none have yet reached TRL 6 because the required high-resolution isotopic measurements are very challenging. Our team is now addressing this challenge by developing the Potassium (K) - Argon Laser Experiment (KArLE) under the NASA Planetary Instrument Definition and Development Program (PIDDP), building on previous work to develop a K-Ar in situ instrument [1]. KArLE uses a combination of several flight-proven components that enable accurate K-Ar isochron dating of planetary rocks. KArLE will ablate a rock sample, determine the K in the plasma state using laser-induced breakdown spectroscopy (LIBS), measure the liberated Ar using quadrupole mass spectrometry (QMS), and relate the two by the volume of the ablated pit using an optical method such as a vertical scanning interferometer (VSI). Our preliminary work indicates that the KArLE instrument will be capable of determining the age of several kinds of planetary samples to +/-100 Myr, sufficient to address a wide range of geochronology problems in planetary science.

  3. Enhanced high harmonic generation driven by high-intensity laser in argon gas-filled hollow core waveguide

    International Nuclear Information System (INIS)

    Cassou, Kevin; Daboussi, Sameh; Hort, Ondrej; Descamps, Dominique; Petit, Stephane; Mevel, Eric; Constant, Eric; Guilbaud, Oilvier; Kazamias, Sophie

    2014-01-01

    We show that a significant enhancement of the photon flux produced by high harmonic generation can be obtained through guided configuration at high laser intensity largely above the saturation intensity. We identify two regimes. At low pressure, we observe an intense second plateau in the high harmonic spectrum in argon. At relatively high pressure, complex interplay between strongly time-dependent ionization processes and propagation effects leads to important spectral broadening without loss of spectral brightness. We show that the relevant parameter for this physical process is the product of laser peak power by gas pressure. We compare source performances with high harmonic generation using a gas jet in loose focusing geometry and conclude that the source developed is a good candidate for injection devices such as seeded soft x-ray lasers or free electron lasers in the soft x-ray range. (authors)

  4. Effect of argon plasma treatment on the output performance of triboelectric nanogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Guang-Gui, E-mail: ggcheng@ujs.edu.cn [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Jiang, Shi-Yu; Li, Kai [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Zhang, Zhong-Qiang [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Wang, Ying; Yuan, Ning-Yi [Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Ding, Jian-Ning, E-mail: dingjn@ujs.edu.cn [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Zhang, Wei [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China)

    2017-08-01

    Highlights: • Two different kinds of PDMS films were prepared by spin-coated. • The PDMS surface was plasma treated with different power and time. • The output performance of TENG was significantly enhanced by plasma treatment. • Plasma treatment effect has time-efficient, the output declines with store time. - Abstract: Physical and chemical properties of the polymer surface play great roles in the output performance of triboelectric nanogenerator (TENG). Specific texture on the surface of polymer can enlarge the contact area and enhance the power output performance of TENG. In this paper, polydimethylsiloxane (PDMS) films with smooth and micro pillar arrays on the surface were prepared respectively. The surfaces were treated by argon plasma before testing their output performance. By changing treatment parameters such as treating time and plasma power, surfaces with different roughness and their relationship were achieved. The electrical output performances of the assembled TENG for each specimen showed that argon plasma treatment has a significant etching effect on the PDMS surface and greatly strengthen its output performance. The average surface roughness of PDMS film increases with the etching time from 5 mins to 15 mins when the argon plasma power is 60 W. Nevertheless, the average surface roughness is inversely proportional to the treatment time for the power of 90W. When treated with 90 W and 5 mins, many uniform micro pillars appeared on the both PDMS surface, and the output performance of the TENG for plasma treated smooth surface is 2.6 times larger than that before treatment. The output voltage increases from 42 V to 72 V, and the short circuit current increases from 4.2 μA to 8.3 μA after plasma treatment of the micro pillar array surface. However, this plasma treatment has time-efficient due to the hydrophobic recovery property of Ar plasma treated PDMS surface, both output voltage and short circuit current decrease significantly after 3

  5. Lasers in Cancer Treatment

    Science.gov (United States)

    ... the advantages of laser therapy? What are the disadvantages of laser therapy? What does the future hold ... therapy is appropriate for them. What are the disadvantages of laser therapy? Laser therapy also has several ...

  6. Update on Development of the Potassium-Argon Laser Experiment (KArLE) Instrument for In Situ Geochronology

    Science.gov (United States)

    Cohen, Barbara A.; Li, Z.-H.; Miller, J. S.; Brinckerhoff, W. B.; Clegg, S. M.; Mahaffy, P. R.; Swindle, T. D.; Wiens, R. C.

    2013-01-01

    Absolute dating of planetary samples is an essential tool to establish the chronology of geological events, including crystallization history, magmatic evolution, and alteration. We are addressing this challenge by developing the Potassium (K) -- Argon Laser Experiment (KArLE), building on previous work to develop a K-Ar in situ instrument. KArLE ablates a rock sample, determines the K in the plasma state using laser-induced breakdown spectroscopy (LIBS), measures the liberated Ar using quadrupole mass spectrometry (QMS), and relates the two by the volume of the ablated pit using laser confocal microscopy (LCM). Our goal is for the KArLE instrument to be capable of determining the age of several kinds of planetary samples to address a wide range of geochronolgy problems in planetary science.

  7. Generation of 275.4-nm UV output from a large-frame argon-ion laser for fluorescence detection in capillary electrophoresis.

    NARCIS (Netherlands)

    Kok, S.J.; de Ridder, T.; Brinkman, U.A.T.; Velthorst, N.H.; Gooijer, C.; Hoornweg, G.Ph.

    1998-01-01

    A standard, relatively old, large-frame argon-ion laser, which is available in many laboratories, was modified to produce output in the deep- UV (275-306 nm) region by installing a set of inexpensive, commercially available laser mirrors. The deep-UV output is generally applicable as excitation

  8. Evaluation of the hydrogen peroxide and special colorant effects under irradiation by argon and diode laser on tooth-whitening in vitro

    International Nuclear Information System (INIS)

    Gaspar, Jose Antonio

    2003-01-01

    The aim of this study is to determine if there is any interaction between special colorant found on bleaching agents that have 35 % of hydrogen peroxide on its composition, and argon or diode laser. The first part of the study was to characterize the extrinsic stain obtained through a staining solution containing products present on the day by day diet of the general population. Thirty-two inferior human extracted incisors, free of caries and without filling material were selected for the study. The laser devices employed were Argon laser (AccuCure 3000 TM - Lasermed), wave length 488 nm, with a 200 mW/cm 2 for 30 seconds in continuos mode; and diode laser (L 808 Medical Laser - Lasering do Brasil), wave length 808 ± 10 nm, with 1,6 W/cm 2 for 30 seconds in continuos mode. The application mode done by a scanning movement over the buccal surface. The bleaching agents used were: Opalescence Extra (OE) - Ultradent Products USA, hydrogen peroxide 35%, gel with Carotene to convert light into heat; Pola Office (PO) - SDI - USA single doses of hydrogen peroxide; Whiteness HP (WHP) - FGM - Brasil, hydrogen peroxide 35%; Opus White (OW) - Sharplan - Israel, hydrogen peroxide 35%. The temperature rise measurement was performed with a thermocouple model 120-202-AJ, Fenwal, inserted into the pulpar chamber. The bleaching material was applied on the tooth surface with 2 mm thickness and then the irradiation was perform. The thirty two teeth were randomized in four groups, two for each laser device. The obtain data demonstrated a superior performance of the Argon laser on tooth whitening and also better results concerning the temperature rise. The alteration on tooth coloration was verified through digital spectrophotometer (Shade-Eye EX - Shofu) and quantitative analyses showed statistical differences among the groups. The bleaching results for Argon laser combined with OE and WHP were superior for the other groups. The mean variation of the temperature rise obtained Argon

  9. Laser-induced fluorescence measurements of argon and xenon ion velocities near the sheath boundary in 3 ion species plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yip, Chi-Shung; Hershkowitz, Noah [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Severn, Greg [Department of Physics, University of San Diego, San Diego, California 92110 (United States); Baalrud, Scott D. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

    2016-05-15

    The Bohm sheath criterion is studied with laser-induced fluorescence in three ion species plasmas using two tunable diode lasers. Krypton is added to a low pressure unmagnetized DC hot filament discharge in a mixture of argon and xenon gas confined by surface multi-dipole magnetic fields. The argon and xenon ion velocity distribution functions are measured at the sheath-presheath boundary near a negatively biased boundary plate. The potential structures of the plasma sheath and presheath are measured by an emissive probe. Results are compared with previous experiments with Ar–Xe plasmas, where the two ion species were observed to reach the sheath edge at nearly the same speed. This speed was the ion sound speed of the system, which is consistent with the generalized Bohm criterion. In such two ion species plasmas, instability enhanced collisional friction was demonstrated [Hershkowitz et al., Phys. Plasmas 18(5), 057102 (2011).] to exist which accounted for the observed results. When three ion species are present, it is demonstrated under most circumstances the ions do not fall out of the plasma at their individual Bohm velocities. It is also shown that under most circumstances the ions do not fall out of the plasma at the system sound speed. These observations are also consistent with the presence of the instabilities.

  10. Morphology of the primary damage caused by the argon-ion laser to the iris of the pigmented rabbit

    International Nuclear Information System (INIS)

    Huber, G.K.; Zypen, E. van der; Frankhauser, F.

    1979-01-01

    The effect of the argon-ion laser upon the iris of the pigmented rabbit were analysed by ultrastructural methods. Apart from the physical parameters of the energy source, the damage strongly depends on the concentration, location, and distribution of the iris pigment. The irradiation of the iris results in the formation of a crater. Depending on the distance of the epicentre of the impact, various degrees of ultrastructural damage are observed. The region immediately adjacent to the crater lumen at a revealing distance of 25 μm consists of homogenous masses, revealing a vacuolar structure. As the only residuals of destroyed cells, melanin granules are observed within the homogenous masses. Destruction of the collagen fibrils and their disintegration into subfibrils with elimination of all cell compartments is found in an area ranging from 25 μm to 300 μm from the wall of the crater. Damage to the chromatin structure is visible up to a distance of 300 μm to 375 μm from the wall of the crater. Characterised by an invasion of macrophages into the damaged area, the cleaning phase starts 24 h after irradiation. The results of this experiment indicate that because of the great energy dose required for man with the inherent widespread tissue damage and low probability of a lasting iridectomy, the cw argon-ion laser appears to be an unsuitable energy source for clinical iridectomy. (orig./AJ) 891 AJ/orig.- 892 MKO [de

  11. Effect of LED and Argon Laser on Degree of Conversion and Temperature Rise of Hybrid and Low Shrinkage Composite Resins.

    Science.gov (United States)

    Pahlevan, Ayob; Tabatabaei, Masumeh Hasani; Arami, Sakineh; Valizadeh, Sara

    2016-01-01

    Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights. DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were placed in Teflon molds and cured from the top. The thermocouple under samples recorded the temperature rise. After initial radiation and specimens reaching the ambient temperature, reirradiation was done and temperature was recorded again. Both temperature rise and DC data submitted to one-way ANOVA and Tukey-HSD tests (5% significance). The obtained results revealed that DC was not significantly different between the understudy composite resins or curing units. Low shrinkage composite resin showed a significantly higher temperature rise than hybrid composite resin. Argon laser caused the lowest temperature rise among the curing units. Energy density of light curing units was correlated with the DC. Type of composite resin and light curing unit had a significant effect on temperature rise due to polymerization and curing unit, respectively.

  12. Effect of Argon Plasma Treatment Variables on Wettability and Antibacterial Properties of Polyester Fabrics

    Science.gov (United States)

    Senthilkumar, Pandurangan; Karthik, Thangavelu

    2016-04-01

    In this research work, the effect of argon plasma treatment variables on the comfort and antibacterial properties of polyester fabric has been investigated. The SEM micrographs and FTIR analysis confirms the modification of fabric surface. The Box-Behnken design was used for the optimization of plasma process variables and to evaluate the effects and interactions of the process variables, i.e. operating power, treatment time and distance between the electrodes on the characteristics of polyester fabrics. The optimum conditions of operating power 600 W, treatment time 30 s, and the distance between the electrodes of 2.8 mm was arrived using numerical prediction tool in Design-Expert software. The plasma treated polyester fabrics showed better fabric characteristics particularly in terms of water vapour permeability, wickability and antibacterial activity compared to untreated fabrics, which confirms that the modified structure of polyester fabric.

  13. Treatment of tracheal mucoepidermoid carcinoma by argon plasma coagulation during pregnancy.

    Science.gov (United States)

    Kesrouani, Assaad; Dabar, Georges; Rahal, Samir; Ghorra, Claude

    2015-05-01

    Mucoepidermoid carcinoma of the tracheobronchial tree is a rare airway tumor (cesarean section. We report the first case to be treated by Argon-Plasma Coagulation (APC) in pregnancy. A 35-year-old Caucasian woman G1P0, at 27 weeks of gestation was admitted to the emergency department because of hemoptysis and severe dyspnea. Bronchoscopy and biopsies diagnosed primary tracheal mucoepidermoid carcinoma. Following an episode of tracheal bleeding, she was intubated. After thorough explanations to the family and obtaining informed consent, therapeutic bronchoscopy, under general anesthesia using a rigid bronchoscope, was performed. The tumor was cored out with the tip of the bronchoscope and removed with an alligator forceps. The tumor bed was coagulated with APC. The obstetrical team was ready to intervene in case of maternal emergency. Immediate follow-up was good, and she left the hospital 4 days later. She delivered at 39 weeks of gestation by cesarean section because of dystocia. Five years later, the patient is doing well without any signs or symptoms of recurrence. Pediatric follow-up is normal. Argon Plasma Coagulation for treatment of mucoepidermoid tracheal carcinoma is feasible during pregnancy. Reporting this case could lead to less aggressive management of mucoepidermoid carcinoma in pregnant patients.

  14. Argon-plasma treatment in benign metastasizing leiomyoma of the lung: A case report

    Directory of Open Access Journals (Sweden)

    A. Bugalho

    2010-11-01

    Full Text Available Benign metastasizing leiomyomas of the lung are rare smooth muscle cells tumours. We report the case of a 48 year-old female who was evaluated due to persistent cough, progressive dyspnoea and constitutional symptoms. Chest computed tomography revealed a left endobronchial mass, multiple parenchyma nodules and a pleural effusion. Bronchial biopsy histological features were consistent with benign metastasizing leiomyoma. The patient was successfully treated with argon-plasma and mechanical debulking. There was no disease relapse in the last four years. Resumo: Os leiomiomas benignos metastizantes pulmonares são tumores raros de células musculares lisas. Uma doente de 48 anos foi avaliada devido a tosse persistente, dispneia progressiva e sintomas constitucionais. A tomografia computorizada do tórax revelou uma massa endobrônquica à esquerda, múltiplos nódulos do parênquima pulmonar e derrame pleural. As características histológicas da biopsia brônquica foram consistentes com o diagnóstico de leiomioma benigno metastizante. A doente foi submetida a coagulação árgon-plasma e desobstrução mecânica com eficácia terapêutica. Verificou-se estabilidade clínica nos últimos quatro anos. Keywords: Benign metastasizing leiomyoma, Lung neoplasms, Diagnosis, Bronchoscopy, Management, Argon-plasma treatment, Palavras-chave: Leiomioma benigno metastizante, Neoplasias pulmonares, Diagnóstico, Broncoscopia, Tratamento, Tratamento árgon-plasma

  15. Ultraviolet versus infrared: Effects of ablation laser wavelength on the expansion of laser-induced plasma into one-atmosphere argon gas

    International Nuclear Information System (INIS)

    Ma Qianli; Motto-Ros, Vincent; Laye, Fabrice; Yu Jin; Lei Wenqi; Bai Xueshi; Zheng Lijuan; Zeng Heping

    2012-01-01

    Laser-induced plasma from an aluminum target in one-atmosphere argon background has been investigated with ablation using nanosecond ultraviolet (UV: 355 nm) or infrared (IR: 1064 nm) laser pulses. Time- and space-resolved emission spectroscopy was used as a diagnostics tool to have access to the plasma parameters during its propagation into the background, such as optical emission intensity, electron density, and temperature. The specific feature of nanosecond laser ablation is that the pulse duration is significantly longer than the initiation time of the plasma. Laser-supported absorption wave due to post-ablation absorption of the laser radiation by the vapor plume and the shocked background gas plays a dominant role in the propagation and subsequently the behavior of the plasma. We demonstrate that the difference in absorption rate between UV and IR radiations leads to different propagation behaviors of the plasma produced with these radiations. The consequence is that higher electron density and temperature are observed for UV ablation. While for IR ablation, the plasma is found with lower electron density and temperature in a larger and more homogenous axial profile. The difference is also that for UV ablation, the background gas is principally evacuated by the expansion of the vapor plume as predicted by the standard piston model. While for IR ablation, the background gas is effectively mixed to the ejected vapor at least hundreds of nanoseconds after the initiation of the plasma. Our observations suggest a description by laser-supported combustion wave for the propagation of the plasma produced by UV laser, while that by laser-supported detonation wave for the propagation of the plasma produced by IR laser. Finally, practical consequences of specific expansion behavior for UV or IR ablation are discussed in terms of analytical performance promised by corresponding plasmas for application with laser-induced breakdown spectroscopy.

  16. In vitro comparative study of share bond of light cured composite resins with halogen light and argon laser, using stainless steel brackets on human premolars

    International Nuclear Information System (INIS)

    Carillo, Vitoria Eugenia Bismarck

    2004-01-01

    The aim of this study in vitro was to compare the share bond strength of the light-cured composite resins Transbond XT (Unitek), with halogen light and argon laser. The Adhesive Remmant Index (ARI) was also investigated. The brackets Dyna lock (3M-UNITEK) were bonded to 75 human premolars, divided into 5 groups (15 each) according to time and the polymerization: Group H20, 15 brackets bonded with halogen light for 20s (10s both sides); Group H40, 15 brackets bonded with halogen light for 40s (20s both sides); Group A40, 15 brackets bonded with argon laser for 40s (20s both sides); Group A20, 15 brackets bonded with argon laser for 20s (10s both sides); Group A10, 15 brackets bonded with argon laser for 10s (5s both sides). The pulpal temperature changes were determined during a polymerization, not exceeding 3,5 deg C. After bonding, the teeth were submitted to a thermo cycled of 700 cycles between 5 deg C and 55 deg C, to simulate the consuming that the light cured composite resin would have in a short space of time. The specimens were then placed in PVC ring and embedded in acrylic resin (Aero-Jet). The tensile bond strength test was performed on an Universal Machine set at a crosshead speed of 1,5 mm/min, and for each rupture we registered a graphic and the best load required in Newtons, was converted to MPa and kgf. The share bond strength showed bigger values for the exposure time of 20 seconds, for the Group bonded for halogen light (H20), 7,45 kgf (7,64 MPa) and for argon laser 7,50 kgf (7,69 MPa); lesser values for the exposure time of 40s for the Group with halogen light (H40), 6,15 kgf (6,30 MPa) and argon laser Group (A40), 6,20 kgf (6,35 MPa) 0; and A10, 4,85 kgf (4,97 MPa). In the ARI Index, only A40 Group showed the 1 Index, with statistical results. In this Group, less than half of the remainder adhesive stayed on the surface of the enamel, conferring specimens failed at the enamel-adhesive interface. The results of the in vitro study demonstrate that

  17. Observation of dielectronic satellites in the K-spectrum of argon ions in plasma produced by femtosecond laser pulses

    International Nuclear Information System (INIS)

    Magunov, A.I.; Faenov, A.Ya.; Skobelev, I.Yu.; Pikuz, T.A.; Biemont, E.; Quinet, P.; Blasco, F.; Bonte, C.; Dorchies, F.; Caillaud, T.; Salin, F.; Stenz, C.

    2002-01-01

    The satellite structure of 1s2p 1,3 P 1 -1s 21 S 0 lines of the He-like argon ion in plasma produced by a 45-fs laser pulse in a gas-jet cluster target is measured with a high spectral resolution. Radiation transitions 2p → 1s from autoionizing states (AISs) are detected for ions ranging from Li-like to F-like. The spectrum observed is theoretically simulated with the use of the spectroscopic data for the AISs of multicharged ions obtained within the multiconfiguration relativistic Hartree-Fock method. Good agreement with experimental data is obtained when the main population channels of these states are taken into account for typical values of cluster-target plasma parameters

  18. Long-term Outcome of Argon Laser Peripheral Iridoplasty in the Management of Plateau Iris Syndrome Eyes.

    Science.gov (United States)

    Peterson, Jeffrey R; Anderson, John W; Blieden, Lauren S; Chuang, Alice Z; Feldman, Robert M; Bell, Nicholas P

    2017-09-01

    To report long-term (>5 y) outcomes of plateau iris syndrome patients treated with argon laser peripheral iridoplasty (ALPI). A retrospective chart review was performed on all patients with plateau iris syndrome treated with ALPI from 1996 to 2007. The study included 22 eyes from 22 patients with plateau iris after peripheral iridotomy that were followed for at least 1 year after ALPI. The primary outcome was incidence of needing any intraocular pressure (IOP)-lowering medications or surgery (either a filtering procedure or phacoemulsification). Demographic and baseline clinical data were summarized by mean (±SD) or frequency (percentage). Snellen best-corrected visual acuity was converted to logMAR. The paired t test was used to compare IOP changes, number of IOP-lowering medications, and best-corrected visual acuity from baseline to annual follow-up. Mean follow-up was 76 months. Only 2 (9%) eyes maintained an IOPiris in our patient population.

  19. Effect of high power CO2 and Yb:YAG laser radiation on the characteristics of TIG arc in atmospherical pressure argon and helium

    Science.gov (United States)

    Wu, Shikai; Xiao, Rongshi

    2015-04-01

    The effects of laser radiation on the characteristics of the DC tungsten inert gas (TIG) arc were investigated by applying a high power slab CO2 laser and a Yb:YAG disc laser. Experiment results reveal that the arc voltage-current curve shifts downwards, the arc column expands, and the arc temperature rises while the high power CO2 laser beam vertically interacts with the TIG arc in argon. With the increase of the laser power, the voltage-current curve of the arc shifts downwards more significantly, and the closer the laser beam impingement on the arc to the cathode, the more the decrease in arc voltage. Moreover, the arc column expansion and the arc temperature rise occur mainly in the region between the laser beam incident position and the anode. However, the arc characteristics hardly change in the cases of the CO2 laser-helium arc and YAG laser-arc interactions. The reason is that the inverse Bremsstrahlung absorption coefficients are greatly different due to the different electron densities of the argon and helium arcs and the different wave lengths of CO2 and YAG lasers.

  20. A new argon gas-based device for the treatment of keloid scars with the use of intralesional cryotherapy

    NARCIS (Netherlands)

    van Leeuwen, M.C.E.; Bulstra, A.E.J.; van Leeuwen, P.A.M.; Niessen, F.B.

    2014-01-01

    Background: Intralesional (IL) cryotherapy is a new promising technique for the treatment of keloid scars, in which the scar is frozen from inside. Multiple devices are available, mostly based on a simple liquid nitrogen Dewar system, which have a limited freezing capacity. Argon gas-based systems

  1. Comparison study of nitrogen and argon processing in a plasma arc centrifugal treatment system

    International Nuclear Information System (INIS)

    Shuey, M.; Tsuji, Y.

    2000-01-01

    Recent testing performed at the plasma research center of Retech Services, Inc. compared nitrogen with argon as plasma gas in the processing of simulated wastes. The testing took place in a full-scale production PACT system under a cooperative research and development study between Retech Services Inc. and Toyo Engineering Corporation. This study shows that simulated waste can be processed by both nitrogen and argon plasmas. Heat losses to the torch nozzle were significantly lower with argon and should be studied further. Both argon and nitrogen plasma were able to process feeds containing both metals and oxides. Some of the drawbacks to using argon plasma are cost, higher volume flow rates, and dual mode torch nozzle erosion. (authors)

  2. Tunable Far Infrared Laser Spectroscopy of Van Der Waals Bonds: Argon-Ammonia

    Science.gov (United States)

    Gwo, Dz-Hung

    Hyperfine resolved vibration-rotation-tunneling spectra of Ar-NH_3 and (NH _3)_2, generated in a planar supersonic jet, have been measured with the Berkeley tunable far infrared laser spectrometer. Among the seven rotationally assigned bands, one band belongs to Ar-NH_3, and the other six belong to (NH_3)_2 . To facilitate the intermolecular vibrational assignment for Ar-NH_3, a dynamics study aided by a permutation-inversion group theoretical treatment is performed on the rovibrational levels. The rovibrational quantum number correlation between the free internal rotor limit and the semi-rigid limit is established to provide a basic physical picture of the evolution of intermolecular vibrational component states (K_{a } manifolds). An anomalous vibronically (not just rovibronically) allowed unique Q branch vibrational band structure is predicted to exist for a near prolate binary complex containing an inverting subunit. According to the model developed in this work, the observed band of Ar-NH_3 centered at 26.470633(17) cm^{-1} can correlate only to either (1) the fundamental dimeric stretching band for the A_2 states with the NH_3 inversional quantum number v_{i} = 1, or (2) the K_{a} = 0 >=ts 0 subband of the lowest internal-rotation -inversion difference band. Although the estimated nuclear quadrupole coupling constant favors a tentative assignment in terms of the first possibility, a definitive assignment will require more far infrared data and a dynamical model incorporating a potential surface.

  3. Nonadiabatic quantum dynamics and laser control of Br2 in solid argon.

    Science.gov (United States)

    Accardi, A; Borowski, A; Kühn, O

    2009-07-02

    A five-dimensional reaction surface-vibronic coupling model is introduced to describe the B- to C-state predissociation dynamics of Br(2) occupying a double substitutional lattice site in a face-centered cubic argon crystal at low temperatures. The quantum dynamics driven by a Franck-Condon vertical excitation is investigated, revealing the role of matrix cage compression for efficient nonadiabatic transitions. Vibrational preexcitation of the Br(2) bond in the electronic ground state can be used to access a different regime of predissociation which does not require substantial matrix compression because the Franck-Condon window shifts into the energetic range of the B-C level crossing. Using optimal control theory, it is shown how vibrational preexcitation can be achieved via a pump-dump-type mechanism involving the repulsive C state.

  4. Argon plasma treatment of silicon nitride (SiN) for improved antireflection coating on c-Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Hemanta; Mitra, Suchismita; Saha, Hiranmay; Datta, Swapan Kumar; Banerjee, Chandan, E-mail: chandanbanerjee74@gmail.com

    2017-01-15

    Highlights: • Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell. • The reduction in reflection due to the formation of a silicon oxynitride/silicon nitride double layer. • EQE reveals a relative increase of 2.72% in J{sub sc} and 4.46% in conversion efficiency. - Abstract: Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell is presented here. Hydrogenated silicon nitride (a-SiN:H) layer has been deposited on a silicon substrate by Plasma Enhanced Chemical Vapour Deposition (PECVD) using a mixture of silane (SiH{sub 4}), ammonia (NH{sub 3}) and hydrogen (H{sub 2}) gases followed by a argon plasma treatment. Optical analysis reveals a significant reduction in reflectance after argon plasma treatment of silicon nitride layer. While FESEM shows nanostructures on the surface of the silicon nitride film, FTIR reveals a change in Si−N, Si−O and N−H bonds. On the other hand, ellipsometry shows the variation of refractive index and formation of double layer. Finally, a c-Si solar cell has been fabricated with the said anti-reflection coating. External quantum efficiency reveals a relative increase of 2.72% in the short circuit current density and 4.46% in conversion efficiency over a baseline efficiency of 16.58%.

  5. Effects of introduction of argon on structural and transparent conducting properties of ZnO-In2O3 thin films prepared by pulsed laser deposition

    International Nuclear Information System (INIS)

    Moriga, Toshihiro; Mikawa, Michio; Sakakibara, Yuji; Misaki, Yukinori; Murai, Kei-ichiro; Nakabayashi, Ichiro; Tominaga, Kikuo; Metson, James B.

    2005-01-01

    Indium-zinc oxide thin films were deposited on a glass substrate from a ZnO and In 2 O 3 mixed target by a pulsed laser deposition technique. The effects on surface texture, structure and transparent conducting properties of the introduction of argon into the chamber during the depositions of amorphous and homologous ZnO-In 2 O 3 thin films were examined. The compositional range where amorphous films formed was widened by the introduction of argon. Resistivity in the region where the amorphous phase appeared increased slightly, with an increase of zinc content, due to the counteractions of decreased Hall mobility and increased carrier concentration. Introduction of argon improved surface roughness of the films and reduced and regulated particle and/or crystallite sizes of the films

  6. The Argon Geochronology Experiment (AGE)

    Science.gov (United States)

    Swindle, T. D.; Bode, R.; Fennema, A.; Chutjian, A.; MacAskill, J. A.; Darrach, M. R.; Clegg, S. M.; Wiens, R. C.; Cremers, D.

    2006-01-01

    This viewgraph presentation reviews the Argon Geochronology Experiment (AGE). Potassium-Argon dating is shown along with cosmic ray dating exposure. The contents include a flow diagram of the Argon Geochronology Experiment, and schematic diagrams of the mass spectrometer vacuum system, sample manipulation mechanism, mineral heater oven, and the quadrupole ion trap mass spectrometer. The Laser-Induced Breakdown Spectroscopy (LIBS) Operation with elemental abundances is also described.

  7. Laser treatment of infantile hemangiomas

    Directory of Open Access Journals (Sweden)

    Michelle Si Ying Ng

    2017-01-01

    Full Text Available Infantile hemangiomas (IHs are the most common benign soft tissue tumor of infancy and childhood. Many patients seek early treatment to halt progression of tumor growth and accelerate regression to achieve quick resolution with good cosmetic outcomes. We reviewed literature through PubMed search on the treatment strategies for IH and share our experience in the field of laser treatment of IH. Treatment strategies for IH include both pharmacological, laser, and surgical interventions depending on the stage and severity of the lesion. Various laser beams have been attempted with varying effects and effectiveness. The 595-nm pulsed dye laser therapy has been most widely utilized owing to its great efficacy but minimal adverse effects. It works by targeting oxyhemoglobin chromophore in blood vessels located within the dermis, causing photothermal damage of these target vessels stimulating quick involution without damaging surrounding healthy skin. It is especially useful in treating ulcerated superficial facial hemangiomas that necessitate rapid healing to avoid unsightly scarring. It has a good safety profile but small risk of epidermal burn, blistering, postinflammatory pigment changes, and scarring remains in those with darker skin types treated with higher fluences and short-pulsed duration. Combination treatment with 1064 nm neodymium-doped yttrium aluminum garnet laser, oral propranolol, and even corticosteroids remains an option, especially in treatment of deep, large, and functionally threatening IH. Careful consideration in consultation with the child's parents given the complexities and potential complications surrounding treatment should always be considered. Laser treatment remains an appropriate treatment for rapidly growing IH in exposed locations at early presentation.

  8. Scanning-probe-microscopy of polyethylene terephthalate surface treatment by argon ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza-Beltran, Francisco [Polymer & Biopolymer Group, Libramiento Norponiente no. 2000, Cinvestav Queretaro, Queretaro 76230 (Mexico); Sanchez, Isaac C. [Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712 (United States); España-Sánchez, Beatriz L.; Mota-Morales, Josué D.; Carrillo, Salvador; Enríquez-Flores, C.I. [Polymer & Biopolymer Group, Libramiento Norponiente no. 2000, Cinvestav Queretaro, Queretaro 76230 (Mexico); Poncin-Epaillard, Fabienne, E-mail: epaill@univ-lemans.fr [Institute for Molecules and Materials, UMR CNRS 6283, Av. O. Messiaen, Universitè du Maine, Le Mans 72085 (France); Luna-Barcenas, Gabriel, E-mail: gluna@qro.cinvestav.mx [Polymer & Biopolymer Group, Libramiento Norponiente no. 2000, Cinvestav Queretaro, Queretaro 76230 (Mexico)

    2015-11-01

    Highlights: • Kelvin-probe-force microscopy helps study of PET surface treated by Ar ion beam. • Ar ion beam surface treatment promotes chain scission and N insertion. • Surface roughness and work function increases as intensity of ion energy increases. • Adhesive force of PET decrease due to the surface changes by ion bombardment. - Abstract: The effect of argon (Ar{sup +}) ion beam treatment on the surface of polyethylene terephthalate (PET) samples was studied by scanning probe microscopy (SPM) and the changes in surface topography were assessed by atomic force microscopy (AFM). Kelvin probe force microscopy (KPFM) sheds light of adhesion force between treated polymer films and a Pt/Cr probe under dry conditions, obtaining the contact potential difference of material. As a result of Ar{sup +} ion bombardment, important surface chemical changes were detected by X-ray photoelectron spectroscopy (XPS) measurements such as chains scission and incorporation of nitrogen species. Ion beam treatment increases the surface roughness from 0.49 ± 0.1 nm to 7.2 ± 0.1 nm and modify the surface potential of PET samples, decreasing the adhesive forces from 12.041 ± 2.1 nN to 5.782 ± 0.06 nN, and producing a slight increase in the electronic work function (Φ{sub e}) from 5.1 V (untreated) to 5.2 V (treated). Ar{sup +} ion beam treatment allows to potentially changing the surface properties of PET, modifying surface adhesion, improving surface chemical changes, wetting properties and surface potential of polymers.

  9. Laser treatment of radish seed

    International Nuclear Information System (INIS)

    Kartalov, P.; Nidal, T.

    1987-01-01

    Trials were conducted in unheated plastic greenhouses in 1985-1986 to test the effect of laser treatment on radish seed. Seed of cv Saxia was irradiated with helio-neon laser of 632.8 Nm wave length at: 2-, 4- and 6-fold irradiation. Results showed that plants of all variants emerged almost simultaneously. The root mass was greatest for plants obtained from 4-fold irradiated seed. Treatment enhanced root production in 1985, and in 1986 4-fold irradiation boosted yield by 15%

  10. Effect of Argon Plasma Treatment on Tribological Properties of UHMWPE/MWCNT Nanocomposites

    Directory of Open Access Journals (Sweden)

    Nitturi Naresh Kumar

    2016-08-01

    Full Text Available Ultra-high molecular weight polyethylene (UHMWPE is widely used in artificial joints in the replacement of knee, hip and shoulder that has been impaired as a result of arthritis or other degenerative joint diseases. The UHMWPE made plastic cup is placed in the joint socket in contact with a metal or ceramic ball affixed to a metal stem. Effective reinforcement of multi-walled carbon nanotubes (MWCNTs in UHMWPE results in improved mechanical and tribological properties. The hydrophobic nature of the nanocomposites surface results in lesser contact with biological fluids during the physiological interaction. In this project, we investigate the UHMWPE/MWCNTs nanocomposites reinforced with MWCNTs at different concentrations. The samples were treated with cold argon plasma at different exposure times. The water contact angles for 60 min plasma-treated nanocomposites with 0.0, 0.5, 1.0, 1.5, and 2.0 wt % MWCNTs were found to be 55.65°, 52.51°, 48.01°, 43.72°, and 37.18° respectively. Increasing the treatment time of nanocomposites has shown transformation from a hydrophobic to a hydrophilic nature due to carboxyl groups being bonded on the surface for treated nanocomposites. Wear analysis was performed under dry, and also under biological lubrication, conditions of all treated samples. The wear factor of untreated pure UHMWPE sample was reduced by 68% and 80%, under dry and lubricated conditions, respectively, as compared to 2 wt % 60 min-treated sample. The kinetic friction co-efficient was also noted under both conditions. The hardness of nanocomposites increased with both MWCNTs loading and plasma treatment time. Similarly, the surface roughness of the nanocomposites was reduced.

  11. Exploring the Effects of Argon Plasma Treatment on Plasmon Frequency and the Chemiresistive Properties of Polymer-Carbon Nanotube Metacomposite

    Directory of Open Access Journals (Sweden)

    Manuel Rivera

    2017-08-01

    Full Text Available Metacomposites, composite materials exhibiting negative permittivity, represent an opportunity to create materials with depressed plasmon frequency without the need to create complex structural geometries. Although many reports exist on the synthesis and characterizations of metacomposites, very few have ventured into exploring possible applications that could take advantage of the unique electrical properties of these materials. In this article, we report on the chemiresistive properties of a polymer-CNT metacomposite and explore how these are affected by Argon plasma treatment.

  12. Trabeculoperforation? Trabeculoretraction? Trabeculoplasty? Review of the various designations used for laser treatment in primary open-angle glaucoma.

    Science.gov (United States)

    Moulin, F; Haut, J; Abboud, E

    1985-01-01

    A historical recall and an attempt to simplify the numerous terms used to designate laser treatments for primary open-angle glaucoma (POAG) are presented. There are two main types of laser treatment for POAG involving two entirely different procedures. The first one, contemporary with the beginning of laser photocoagulation, imitates the action of the scalpel, namely goniotomy ab interno or trabeculotomy ab externo. The goal of this early procedure was to produce a through and through trabecular hole but instead of the cutting edge of the knife, it uses the explosive effect of the laser. This procedure has been given numerous names. Among the most frequent ones, we find: 'laser trabeculopuncture', 'laseropuncture', 'goniopuncture', 'laser trabeculectomy', 'laser trabeculotomy', 'laser trabeculopexy'. We prefer to gather them under an explicit generic term: 'laser trabeculoperforation'. The results of this procedure have been very disappointing until now, particularly with conventional lasers, e.g. continuous-wave argon laser, owing to the predominance of their thermal effect over their explosive effect and also to the great scarring property of the trabecular meshwork. In the second type of glaucoma laser treatment, instead of trying to make a patent hole in the trabecular meshwork, the surgeon seeks to reshape the inner trabecular surface by means of argon laser microscars in order to produce a reversal of the trabecular collapse, which is now considered to be one of the major etiologies of POAG.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Time-resolved tunable diode laser absorption spectroscopy of excited argon and ground-state titanium atoms in pulsed magnetron discharges

    Czech Academy of Sciences Publication Activity Database

    Sushkov, V.; Do, H.T.; Čada, Martin; Hubička, Zdeněk; Hippler, R.

    2013-01-01

    Roč. 22, č. 1 (2013), 1-10 ISSN 0963-0252 R&D Projects: GA ČR(CZ) GAP205/11/0386; GA ČR GAP108/12/2104 Institutional research plan: CEZ:AV0Z10100522 Keywords : absorption spectroscopy * diode laser * magnetron * argon metastable * HiPIMS * titanium * time-resolved Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.056, year: 2013 http://iopscience.iop.org/0963-0252/22/1/015002/

  14. Surface wet-ability modification of thin PECVD silicon nitride layers by 40 keV argon ion treatments

    Science.gov (United States)

    Caridi, F.; Picciotto, A.; Vanzetti, L.; Iacob, E.; Scolaro, C.

    2015-10-01

    Measurements of wet-ability of liquid drops have been performed on a 30 nm silicon nitride (Si3N4) film deposited by a PECVD reactor on a silicon wafer and implanted by 40 keV argon ions at different doses. Surface treatments by using Ar ion beams have been employed to modify the wet-ability. The chemical composition of the first Si3N4 monolayer was investigated by means of X-ray Photoelectron Spectroscopy (XPS). The surface morphology was tested by Atomic Force Microscopy (AFM). Results put in evidence the best implantation conditions for silicon nitride to increase or to reduce the wet-ability of the biological liquid. This permits to improve the biocompatibility and functionality of Si3N4. In particular experimental results show that argon ion bombardment increases the contact angle, enhances the oxygen content and increases the surface roughness.

  15. A new argon gas-based device for the treatment of keloid scars with the use of intralesional cryotherapy.

    Science.gov (United States)

    van Leeuwen, Michiel C E; Bulstra, Anne-Eva J; van Leeuwen, Paul A M; Niessen, Frank B

    2014-12-01

    Intralesional (IL) cryotherapy is a new promising technique for the treatment of keloid scars, in which the scar is frozen from inside. Multiple devices are available, mostly based on a simple liquid nitrogen Dewar system, which have a limited freezing capacity. Argon gas-based systems ensure accurate and highly controlled freezing and have shown to be effective within the field of oncologic surgery. However, this technique has never been used for the treatment of keloid scars. This prospective study evaluates an argon gas-based system for the treatment of keloids in a patient population including all Fitzpatrick skin types with a 1-year follow-up. Twenty-five patients with 30 keloid scars were included and treated with a device called Seednet (Galil Medical, Yokneam, Israel). Scar quality and possible scar recurrence were assessed before treatment and post treatment (6 and 12 months) with objective devices determining scar color, scar elasticity, scar volume, and patient's skin type. In addition, scars were evaluated using the Patient and Observer Scar Assessment Scale. After 12 months, a significant volume reduction of 62% was obtained, p = 0.05. Moreover, complaints of pain and itching were alleviated and scar quality had improved according to the Patient and Observer Scar Assessment Scale. Scar pigmentation recovered in 62% of all keloid scars within 12 months. Five out of 30 (17%) scars recurred within 12 months, three of which had previously been treated with liquid nitrogen-based IL cryotherapy. Both recurrent and persistent hypopigmentation were mainly seen in Afro-American patients. IL cryotherapy with the use of an argon gas-based system proves to be effective in the treatment of keloid scars, yielding volume reduction and low recurrence rates. Although hypopigmentation recovered in most cases, it is strongly related to non-Caucasian patients. Finally, additional treatment of keloid scars previously unresponsive to IL cryotherapy is predisposed to a high

  16. Semiconductor lasers in rheumatological treatment

    Science.gov (United States)

    Pascu, Mihail-Lucian; Suteanu, S.; Ignat, P.; Pruna, Simion; Chitu, A.

    1995-03-01

    A computer controlled equipment, containing 6 lasers (HeNe and 5 diode lasers--DL) conceived to be used in rheumatological treatment is reported. DL emit at 895 nm and for typical applications, their expanded spots are superposed within the irradiation plane, on the HeNE defocused spot used to define the surface to be irradiated. DL emit 100 nsec pulses between 0.5 KHz and 1.5 KHz repetition rate and 0.5 mW average power (measured at 1 KHz). 150 patients with rheumathologic diseases were treated: lumbar spondylosis (75), gonarthrosis (30), cervical spondylosis (21), coxarthrosis (15), Heberden and Bouchard (9). The treatment consisted of: group I, 50 patients--laser therapy, 10 min/day, 10 days; group II, 50 patients--classical antirheumatic treatment; group III, 50 patients--mixed treatment. Assessment of sympathetic skin activity made using reactometry measurements, shows that latency time was longer before irradiation, 1867 +/- 289) msec then after, (1234 +/- 321) msec. Pain rating indexes decreasing for all three groups of patients were measured. Better results for more superficial diseases were obtained and best results were observed after irradiation with 1 KHz - 1.5 KHz repetition rate IR pulses. Better results were obtained when spot irradiation in a few points combined with zone irradiations was used.

  17. Laser Induced Fluorescence (LIF) Measurements of Neutral (ArI) and singly-ionized (ArII) Argon in a LargeScale Helicon Plasma

    Science.gov (United States)

    Kelly, R. F.; Fisher, D. M.; Hatch, M. W.; Gilmore, M.; Dwyer, R. H.; Meany, K.; Zhang, Y.; Desjardins, T. R.

    2017-10-01

    In order to investigate the role of neutral dynamics in helicon discharges in the HelCat (Helicon-Cathode) plasma device at U. New Mexico, a Laser Induced Fluorescence (LIF) system has been developed. The LIF system is based on a >250 mW, tunable diode laser with a tuning range between 680 and 700nm. For neutral Argon, the laser pumps the metastable (2P3/20) 4s level to the (2P1/20) 4p level using 696. 7352 nm light. The fluorescence radiation from decay to the (2P1/20) 4s level at 772. 6333 nm is observed. For singly ionized Argon, the laser pumps the 3s23p4(3 P)3d level to the 3s23p4(3 P)4p level using 686.3162nm light. The fluorescence radiation from the decay to the 3s23p4(3 P)4s level is observed. The system design, and velocity measurements in the axial, azimuthal and radial directions for ArI, and in the axial direction for ArII will be presented. Supported by U.S. National Science Foundation Award 1500423.

  18. Temporal and spatial dynamics of laser-induced aluminum plasma in argon background at atmospheric pressure: Interplay with the ambient gas

    International Nuclear Information System (INIS)

    Ma, Q.L.; Motto-Ros, V.; Lei, W.Q.; Boueri, M.; Bai, X.S.; Zheng, L.J.; Zeng, H.P.; Yu, J.

    2010-01-01

    Laser ablation in background gas implies supplementary complexities with respect to what happens in the vacuum. It is however essential to understand in detail the involved mechanisms for a number of applications requiring the ablation to be performed in an ambient gas at relative high pressure, such as pulsed-laser deposition, or laser-induced breakdown spectroscopy. In this paper, the expansion of a vapor plume ablated from an aluminum target into an argon gas at atmospheric pressure is experimentally investigated using time- and space-resolved emission spectroscopy. The obtained results provide a detailed description of the interplay between the vapor and the gas. The electron density, the temperature and the number densities (and therefore the partial pressures) of aluminum vapor and argon gas have been measured in and surrounding the vapor plume. Our observations show a confinement of the vapor plume by the gas, which is expected as predicted by the usual hydrodynamics models. The result is a plasma core with quite uniform distributions in electron density, temperature and number densities. Such plasma core presents an ideal emission source for spectroscopic applications. It is however evidenced by our observations that a large amount of argon is mixed into the aluminum plume in the plasma core, which invalidates in the experimental conditions that we used, the hydrodynamic 'piston' model where the background gas is pushed out by the shock wave surrounding the vapor plume. Instead, other mechanisms such as laser-supported detonation wave should play important roles in the early stage of the expansion of the plasma for the determination of its morphology at longer delays.

  19. Dynamics of the spectral behaviour of an ultrashort laser pulse in an argon-gas-filled capillary discharge-preformed plasma channel

    Directory of Open Access Journals (Sweden)

    Sakai S.

    2013-11-01

    Full Text Available We have reported the argon plasma waveguide produced in an alumina (Al2O3 capillary discharge and used to guide ultrashort laser pulses at intensities of the order of 1016  W/cm2. A one-dimensional magnetohydrodynamic (MHD code was used to evaluate the average degree of ionization of Ar in the preformed plasma channel. The spectrum of the propagated laser pulse in the Ar plasma waveguide was not modified and was well reproduced by a particle-in-cell (PIC simulation under initial ion charge state of Ar3+ in the preformed plasma waveguide. The optimum timing for the laser pulse injection was around 150 ns after initiation of a discharge with a peak current of 200 A.

  20. The study of selective emission lines from plasma, obtained by evaporating as sample by laser radiation in air and argon media

    International Nuclear Information System (INIS)

    Sufian, A.; Dimitrov, G.

    1993-01-01

    Ultra violet visible emission spectroscopic analysis of a plasma produced through laser interaction with a solid probe in different gaseous atmospheres is conducted. Reported are the effects of air and argon, as enveloping media, on the spectral intensities of some lines. The temperature gradient of the plasma, in different atmosphere, is also plotted. In order to improve the detection limits of individual elements, suggested are the possible areas of illuminating the slit of the spectroscopic from the plasma, in respect of the height, above the sample, when working in different gaseous media. (author)

  1. Investigation of local thermodynamic equilibrium of laser induced Al2O3–TiC plasma in argon by spatially resolved optical emission spectroscopy

    Directory of Open Access Journals (Sweden)

    K. Alnama

    2016-06-01

    Full Text Available Plasma plume of Al2O3–TiC is generated by third harmonic Q-switched Nd:YAG nanosecond laser. It is characterized using Optical Emission Spectroscopy (OES at different argon background gas pressures 10, 102, 103, 104 and 105 Pa. Spatial evolution of excitation and ionic temperatures is deduced from spectral data analysis. Temporal evolution of Ti I emission originated from different energy states is probed. The correlation between the temporal behavior and the spatial temperature evolution are investigated under LTE condition for the possibility to use the temporal profile of Ti I emission as an indicator for LTE validity in the plasma.

  2. Laser photoradiation therapy in the treatment of malignant tumors

    International Nuclear Information System (INIS)

    Tomio, L.; Corti, L.; Polico, C.

    1987-01-01

    Photoradiation theraphy or, as more recently defined, photodynamic theraphy (PDT) has been effective in the treatment of several kinds of cancers, above all the skin, lung, esophagus and bladder. It is based on the preferential retention by tumor and photosensitizing properties of certains porphyrins.It has been initiated to investigate this technique experimentally in 1978 and clinically in september 1982, with report of the initial results in 38 patients in 1985. In this paper the more recent experience of PDT in 18 patients affected by different tumors and treated with a new double argon-dye laser system is described. These tumors included 8 carcinomas of the esophagus, 5 basal cell skin cancers, 2 carcinomas of the lung, 2 squamous cell carcinomas of the oral cavity and 1 early gastric cancer. Clinical results and technical problems of PDT are discussed

  3. Sensibilidade ao contraste na retinopatia diabética tratada por panfotocoagulação com laser de argônio Contrast sensitivity in diabetic retinopathy treated with argon laser panphotocoagulation

    Directory of Open Access Journals (Sweden)

    Otacílio de Oliveira Maia Júnior

    2007-10-01

    Full Text Available OBJETIVO: Avaliar a sensibilidade ao contraste na retinopatia diabética (RD tratada por panfotocoagulação com laser de argônio. MÉTODOS: Estudo prospectivo de portadores de retinopatia diabética e acuidade visual de 20/20, tratados com panfotocoagulação retiniana, conforme critérios do ETDRS. Os pacientes foram submetidos, inicialmente, a exame oftalmológico completo e teste de sensibilidade ao contraste (Vision Contrast Test System. Após 3 meses do tratamento, foram reavaliados por meio da acuidade visual e sensibilidade ao contraste. RESULTADOS: A amostra foi composta por 28 pacientes (28 olhos, todos portadores de diabetes tipo 2. A idade variou entre 45 a 77 anos (média de 57,8 ± 8,0, sendo 19 pacientes (67,9% do sexo masculino e 9 (32,1% do feminino. Quanto ao tipo de retinopatia, 18 (64,3% apresentavam RD proliferativa e 10 (35,7%, RD não proliferativa muito grave. Não foi observada nenhuma alteração na acuidade visual pós-tratamento. Quanto à sensibilidade ao contraste, não houve alteração entre o pré e pós-tratamento em todas freqüências espaciais avaliadas: 1,5 (p=0,191; 3,0 (p=0,850; 6,0 (p=0,374; 12,0 (p=0,674 e 18,0 (p=0,443. CONCLUSÃO: Não foi evidenciada alteração significante na sensibilidade ao contraste de portadores de retinopatia diabética após panfotocoagulação com laser de argônio no período estudado.PURPOSE: To evaluate contrast sensitivity in patients with diabetic retinopathy (DR treated with argon laser panphotocoagulation. METHODS: Prospective study of patients with diabetic retinopathy and 20/20 visual acuity, treated with retinal panphotocoagulation, following ETDRS criteria. The patients were submitted, initially, to complete ophthalmologic evaluation and contrast sensitivity testing (Vision Contrast Test System. After 3 months of treatment, they were reevaluated by means of visual acuity and contrast sensitivity. RESULTS: The sample comprised 28 patients (28 eyes, all with type II

  4. Laser treatment of plasma sprayed HA coatings

    NARCIS (Netherlands)

    Khor, KA; Vreeling, A; Dong, ZL; Cheang, P

    1999-01-01

    Laser treatment was conducted on plasma sprayed hydroxyapatite (HA) coatings using a Nd-YAG pulse laser. Various laser parameters were investigated. The results showed that the HA surface melted when an energy level of greater than or equal to 2 J and a spot size of 2 mm was employed during

  5. Evaluation of the hydrogen peroxide and special colorant effects under irradiation by argon and diode laser on tooth-whitening in vitro; Avaliacao do efeito de corantes especiais e peroxido de hidrogenio irradiados por laser de argonio e laser de diodo no clareamento dental 'in vitro'

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar, Jose Antonio

    2003-07-01

    The aim of this study is to determine if there is any interaction between special colorant found on bleaching agents that have 35 % of hydrogen peroxide on its composition, and argon or diode laser. The first part of the study was to characterize the extrinsic stain obtained through a staining solution containing products present on the day by day diet of the general population. Thirty-two inferior human extracted incisors, free of caries and without filling material were selected for the study. The laser devices employed were Argon laser (AccuCure 3000 TM - Lasermed), wave length 488 nm, with a 200 mW/cm{sup 2} for 30 seconds in continuos mode; and diode laser (L 808 Medical Laser - Lasering do Brasil), wave length 808 {+-} 10 nm, with 1,6 W/cm{sup 2} for 30 seconds in continuos mode. The application mode done by a scanning movement over the buccal surface. The bleaching agents used were: Opalescence Extra (OE) - Ultradent Products USA, hydrogen peroxide 35%, gel with Carotene to convert light into heat; Pola Office (PO) - SDI - USA single doses of hydrogen peroxide; Whiteness HP (WHP) - FGM - Brasil, hydrogen peroxide 35%; Opus White (OW) - Sharplan - Israel, hydrogen peroxide 35%. The temperature rise measurement was performed with a thermocouple model 120-202-AJ, Fenwal, inserted into the pulpar chamber. The bleaching material was applied on the tooth surface with 2 mm thickness and then the irradiation was perform. The thirty two teeth were randomized in four groups, two for each laser device. The obtain data demonstrated a superior performance of the Argon laser on tooth whitening and also better results concerning the temperature rise. The alteration on tooth coloration was verified through digital spectrophotometer (Shade-Eye EX - Shofu) and quantitative analyses showed statistical differences among the groups. The bleaching results for Argon laser combined with OE and WHP were superior for the other groups. The mean variation of the temperature rise

  6. Evaluation of the hydrogen peroxide and special colorant effects under irradiation by argon and diode laser on tooth-whitening in vitro; Avaliacao do efeito de corantes especiais e peroxido de hidrogenio irradiados por laser de argonio e laser de diodo no clareamento dental 'in vitro'

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar, Jose Antonio

    2003-07-01

    The aim of this study is to determine if there is any interaction between special colorant found on bleaching agents that have 35 % of hydrogen peroxide on its composition, and argon or diode laser. The first part of the study was to characterize the extrinsic stain obtained through a staining solution containing products present on the day by day diet of the general population. Thirty-two inferior human extracted incisors, free of caries and without filling material were selected for the study. The laser devices employed were Argon laser (AccuCure 3000 TM - Lasermed), wave length 488 nm, with a 200 mW/cm{sup 2} for 30 seconds in continuos mode; and diode laser (L 808 Medical Laser - Lasering do Brasil), wave length 808 {+-} 10 nm, with 1,6 W/cm{sup 2} for 30 seconds in continuos mode. The application mode done by a scanning movement over the buccal surface. The bleaching agents used were: Opalescence Extra (OE) - Ultradent Products USA, hydrogen peroxide 35%, gel with Carotene to convert light into heat; Pola Office (PO) - SDI - USA single doses of hydrogen peroxide; Whiteness HP (WHP) - FGM - Brasil, hydrogen peroxide 35%; Opus White (OW) - Sharplan - Israel, hydrogen peroxide 35%. The temperature rise measurement was performed with a thermocouple model 120-202-AJ, Fenwal, inserted into the pulpar chamber. The bleaching material was applied on the tooth surface with 2 mm thickness and then the irradiation was perform. The thirty two teeth were randomized in four groups, two for each laser device. The obtain data demonstrated a superior performance of the Argon laser on tooth whitening and also better results concerning the temperature rise. The alteration on tooth coloration was verified through digital spectrophotometer (Shade-Eye EX - Shofu) and quantitative analyses showed statistical differences among the groups. The bleaching results for Argon laser combined with OE and WHP were superior for the other groups. The mean variation of the temperature rise

  7. Laser welding, cutting and surface treatment

    International Nuclear Information System (INIS)

    Crafer, R.C.

    1984-01-01

    Fourteen articles cover a wide range of laser applications in welding, cutting and surface treatment. Future trends are covered as well as specific applications in shipbuilding, the manufacture of heart pacemakers, in the electronics industry, in automobile production and in the aeroengine industry. Safety with industrial lasers and the measurement of laser beam parameters are also included. One article on 'Lasers in the Nuclear Industry' is indexed separately. (U.K.)

  8. Basal body and striated rootlet changes in primate macular retinal pigmented epithelium after low level diffuse argon laser radiation. Final report 1981-1982

    Energy Technology Data Exchange (ETDEWEB)

    Schuschereba, S.T.; Zwick, H.; Stuck, B.E.; Beatrice, E.S.

    1982-09-01

    Basal bodies or centrioles (BB - microtubule organizing centers) and striated rootlets (SR - bundles of 60 A action-like filaments) have a close association in primate retinal pigmented epithelial (RPE) cells. The frequency of occurrence of these structures was evaluated in the macular RPE after repeated exposure to low level diffuse argon laser radiation (DALR). The awake chaired animal's head was restrained and positioned near the center of the 0.75 m hemisphere which was diffusely irradiated with 514.5 nm laser radiation. The right eye of each subject was occluded during the two-hour exposure session. The first subject received 24 cumulative hours of exposure, the second, 40 hours and the third, 42 hours.

  9. Análise química e morfológica do esmalte dentário humano tratado com laser argônio durante a colagem ortodôntica Chemical and morphological analysis of the human dental enamel treated with argon laser during orthodontic bonding

    Directory of Open Access Journals (Sweden)

    Glaucio Serra Guimarães

    2011-04-01

    reason, were selected and sectioned across the long axis in two equal segments. One section of each tooth was treated and the other remained untreated. A total of thirty samples was analyzed, creating the laser group (n =15 and the control group (n =15. The treatment was done with 250 mW argon laser beam for 5 seconds, with energy density of 8 J/cm². RESULTS: The X-ray analysis demonstrated two different phases in both groups, the apatite and the monetite phases. The reduction of the monetite phase was significant following laser treatment, suggesting higher crystallinity. The EDS analysis showed an increase in the calcium-phosphorus ratio in the laser group, linked with the decrease of the monetite phase. CONCLUSIONS: The surface morphology was smoother after the laser exposure. The results of high crystallinity and superficial enamel smoothness in the laser group are suggestive of the caries resistance increase of the tooth enamel.

  10. Endoscopic laser treatment for rectosigmoid villous adenoma: factors effecting the results

    Science.gov (United States)

    Brunetaud, Jean Marc; Maunoury, Vincent; Cochelard, Dominique; Boniface, Brigitte

    1994-12-01

    This present work reports the long term results after endoscopic laser treatment in 474 patients with benign rectosigmoid villous adenomas revealed by biopsy. Two types of wavelength were used: The 1.06 micrometers infrared light from the Nd:YAG laser and the green light from the argon laser or the Nd:YAG frequency doubled laser. In some patients, both wavelengths were used. Treatment was completed in 415 patients. Total tumor destruction was obtained in 92.8% of them, a carcinoma was detected in 6.5% on biopsy specimens obtained during laser treatment, and benign villous tissue persisted in 0.7%. During the average 30 mo. follow up period of the patients with total tumor destruction, 18% had a tumor recurrence. Treatment was well tolerated with a 1.8% complication rate (one perforation, one hemorrhage, and 7 stenosis requiring dilatation). Because treatment is long and difficult and cancer rate is high, endoscopic laser should be limited in patients with a circumferential villous adenoma to nonsurgical candidates. The risk of complication after surgery (some being fatal) has to be balanced against the risk of undetected carcinoma in the other patients and the indication for endoscopic laser treatment should be discussed case by case.

  11. [Research on the laser atomization treatment machine].

    Science.gov (United States)

    Jiang, Bei-sheng; Tian, Rong-zhe; Zhang, Liang

    2005-07-01

    This text has introduces a new-type laser treatment device. It utilizes the ultrasound atomized gas passage as its optics and makes the laser beams together with the atomized medicine to be transmitted to the patient's respiratory track and lungs for treatment.

  12. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

    Science.gov (United States)

    Ritts, Andy Charles; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

    2010-01-01

    The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces for composite restoration. Extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated by using a non-thermal atmospheric argon plasma brush for various durations. The molecular changes of the dentin surfaces were analyzed using FTIR/ATR and an increase in carbonyl groups on dentin surfaces was detected with plasma treated dentin. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars as the specimens for tensile test. Student Newman Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment. However, the bonding strength to plasma treated inner dentin did not show any improvement. It was found that plasma treatment of peripheral dentin surface up to 100 s gave an increase in interfacial bonding strength, while a prolong plasma treatment of dentin surfaces, e.g., 5 min treatments, showed a decrease in interfacial bonding strength. PMID:20831586

  13. Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

    Science.gov (United States)

    Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

    2017-07-01

    In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

  14. Investigations of the cathode region of an argon arc plasma by degenerate four-wave mixing laser spectroscopy and optical emission spectroscopy

    International Nuclear Information System (INIS)

    Dzierzega, K; Pokrzywka, B; Pellerin, S

    2004-01-01

    Degenerate four-wave mixing (DFWM) laser spectroscopy was used in local studies of atmospheric pressure argon plasma generated in a free-burning arc. The results of plasma diagnostics using the DFWM method were compared to the results obtained with optical emission measurements. In the cathode region of the arc the maxima of both the DFWM signal and the emission coefficient for the 696.5 nm Ar I line depend on the distance from the cathode tip. This effect proves the departure of the plasma state from local thermal equilibrium (LTE) as it has been reported by many authors. On the other hand the Stark shifts of the 696.5 nm Ar I line determined by the DFWM method in relation to plasma diagnostic results show no deviations from LTE on the arc axis down to 1.0 mm from the cathode tip

  15. Clinical application of argon-helium cryotherapy system in the treatment of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Guo Zhi Xin Wenge; Liu Fang; Yu Haipeng; Li Baoguo; Guo Xiuying; Zhang Sheng; Fu Li; Xing Jizhong; Zhang Junyi; Wang Youju; Gong Bing

    2005-01-01

    Objective: To explore the efficacy of Argon-Helium cryotherapy system (AHCS) after transarterial chemoembolization (TACE) in treating the large hepatocellular carcinoma (HCC) with diameter over 10 cm. Methods: Forty-eight HCC patients were randomly divided into therapy group (n=26) and control group (n=22), and patients in the therapy group were treated with AHCS [(Cryocare) TM Surgical System] 4 weeks after TACE. Tumor size ranged from 10 to 13 cm. All tumors were hypervascular with Child A in 38 cases and Child B in 10 cases. AFP was positive in 40 cases and negative in 8. Reexamination included pathology, tumor marker, T-lymphocyte subgroup, ultrasound, CT, or MRI. Necrosis rate was calculated with Cavalieri theory. Numerical rating scale (NRS) for pain evaluation and EORTC QLQ-C30 for life quality evaluation were performed. Results: Technical success rate was 100%. Follow-up time varied from 6 to 14 months, and follow-up rate was 100%. Average neoplasm necrosis rate was 8.07% after TACE, and 28.65% after AHCS. Tumor marker significantly deceased after AHCS. The necrosis after AHCS was more significant than that after TACE alone. AST and ALT deteriorated for 2 weeks after TACE and for 1 week after AHCS. Local pain 48 hours after AHCS was the only more serious side effect than after TACE. Immunological function was significantly suppressed after TACE. CD 3 + , CD 4 + , and NK increased after AHCS, and abnormal distribution was corrected. Coagulative necrosis was founded in the tumor target area pathologically. Quality of life increased according EORTC QLQ-C30 results after AHCS. No severe complication occurred. Conclusion: AHCS after TACE can reduce tumor load in short term, and it can improve cellular immunity, ameliorate the liver function, increase the quality of life, and make satisfactory effect in the near future. The key point to increase therapeutic efficacy is the embolization of blood vessel and control of heat sink effect by TACE. Interventional

  16. Effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded high strength aluminium alloy

    International Nuclear Information System (INIS)

    Balasubramanian, V.; Ravisankar, V.; Reddy, G. Madhusudhan

    2007-01-01

    This paper reveals the effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded AA7075 aluminium alloy. This alloy has gathered wide acceptance in the fabrication of light weight structures requiring high strength-to-weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due to their comparatively easier applicability and better economy. Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results inferior weld mechanical properties and poor resistance to hot cracking. In this investigation, an attempt has been made to refine the fusion zone grains by applying pulsed current welding technique. Four different welding techniques have been used to fabricate the joints and they are: (i) continuous current GTAW (CCGTAW), (ii) pulsed current GTAW (PCGTAW), (iii) continuous current GMAW (CCGMAW) and (iv) pulsed current GMAW (PCGMAW) processes. As welded joint strength is much lower than the base metal strength and hence, a simple aging treatment has been given to improve the tensile strength of the joints. Current pulsing leads to relatively finer and more equi-axed grain structure in GTA and GMA welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain structures. Post weld aging treatment is accompanied by an increase in tensile strength and tensile ductility

  17. Laser treatment of Port-wine stains

    OpenAIRE

    Boffa, Michael J.

    2001-01-01

    A state-of-the-art pulsed dye laser machine to treat port-wine stains and other vascular lesions has been available in the Malta Health Service since 1999. This article reviews the pathophysiology and clinical features of port- wine stains and describes the principles of laser treatment for this condition.

  18. Analysis of Indium Tin Oxide Film Using Argon Fluroide (ArF) Laser-Excited Atomic Fluorescence of Ablated Plumes.

    Science.gov (United States)

    Ho, Sut Kam; Garcia, Dario Machado

    2017-04-01

    A two-pulse laser-excited atomic fluorescence (LEAF) technique at 193 nm wavelength was applied to the analysis of indium tin oxide (ITO) layer on polyethylene terephthalate (PET) film. Fluorescence emissions from analytes were induced from plumes generated by first laser pulse. Using this approach, non-selective LEAF can be accomplished for simultaneous multi-element analysis and it overcomes the handicap of strict requirement for laser excitation wavelength. In this study, experimental conditions including laser fluences, times for gating and time delay between pulses were optimized to reveal high sensitivity with minimal sample destruction and penetration. With weak laser fluences of 100 and 125 mJ/cm 2 for 355 and 193 nm pulses, detection limits were estimated to be 0.10% and 0.43% for Sn and In, respectively. In addition, the relation between fluorescence emissions and number of laser shots was investigated; reproducible results were obtained for Sn and In. It shows the feasibility of depth profiling by this technique. Morphologies of samples were characterized at various laser fluences and number of shots to examine the accurate penetration. Images of craters were also investigated using scanning electron microscopy (SEM). The results demonstrate the imperceptible destructiveness of film after laser shot. With such weak laser fluences and minimal destructiveness, this LEAF technique is suitable for thin-film analysis.

  19. Electrocautery Snare Is Combined with CO2 Cryosurgery and Argon Plasma Coagulation for the Treatment of Airway Tumors and Granulomas

    Directory of Open Access Journals (Sweden)

    Hongwu WANG

    2013-06-01

    Full Text Available Background and objective To observe the clinical effects and safety of endobronchial electrocautery snare combined with CO2 cryosurgery for the treatment of tracheobronchial obstructive lesions. Materials and methods Seventy-seven patients with airway tumor or granuloma were retrospectively reviewed, including 70 malignant airway obstruction and 7 benign airway lesions, for the treatment of endobronchial electrocautery snare plus CO2 cryosurgery and argon plasma coagulation (APC. Results Eighty-five endobronchial snares were performed in 77 cases. 42.9% of the obstructive lesions were located in right bronchial orifice, 38.3% in main trachea 21.4% in left bronchial orifice. 89.7% of the malignant tumor was mixed type of lesions (endobronchial plus bronchial or external bronchial, only 10.3% was endobronchial. Obstructive stenosis was significant relieved after snare (80% before vs 20% after, P<0.01 in all patients. Karnofsky Performance Status (KPS and shortbreath score were obviously improved after snare. There was no severe complications related to the procedures. Conclusion Endobronchial electrocautery snare is an effective and safe approach for tracheobronchial obstructions with few complications.

  20. Krypton laser membranotomy in the treatment of dense premacular hemorrhage.

    Science.gov (United States)

    Chen, Yung-Jen; Kou, His-Kung

    2004-12-01

    Neodymium:YAG (Nd:YAG) laser and argon laser membranotomy have been used in patients with premacular hemorrhage to drain premacular blood into the vitreous cavity and rapidly clear the hemorrhage. However, the Nd:YAG laser appears to be difficult to use, and argon laser energy may be more likely to be absorbed by the ocular media. We performed a study to evaluate the safety and effectiveness of krypton laser membranotomy in selected cases of premacular hemorrhage. Sixteen patients (17 eyes) with dense premacular hemorrhage for 2 weeks or less were enrolled from April 1998 to February 2004. The causes of premacular hemorrhage were proliferative diabetic retinopathy (PDR) in 12 eyes, Valsalva retinopathy in 3 eyes, leukemia in I eye and retinal arterial macroaneurysm in I eye. Krypton laser was used to create a membranotomy on the sloping edge of the premacular hemorrhage. Five eyes with PDR were treated with inferior panretinal photocoagulation and laser membranotomy simultaneously. After intravitreal dispersion of premacular blood, fundus examination was performed in all eyes and fluorescein angiography in five eyes to evaluate retinal damage. All eyes had visual improvement within 2 weeks postoperatively. No retinal damage was seen at the site of membranotomy in any eye. No eye needed vitrectomy postoperatively during a mean follow-up duration of 18.6 months. Krypton laser membranotomy appears to be a safe and simple alternative procedure for treating selected cases of premacular hemorrhage. Further trials are necessary to evaluate its benefit.

  1. Side effects of endobronchial laser treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dierkesmann, R.; Huzly, A.

    1985-03-01

    Side effects that have occurred in over 250 endobronchial laser treatments are reported. The laser has been used in severe tracheal and in bronchial obstructions. In two cases significant bleeding had to be treated with tamponade. In one patient an emphysema of the mediastinum developed, in 2 further patients a small pneumothorax. Perforation of the airway was not detected and no special treatment was necessary. Three patients with life-threatening tracheal stenoses and one patient with severe stenosis of both the mainstem bronchi due to metastasis in the bifurcation lymph node had a large defect in the tracheal or bronchial wall with a deep necrosis five to twelve weeks after laser treatment; all these patients had extensive radiotherapy in addition. One patient died due to severe respiratory insufficiency, probably caused by smoke intoxication. After the laser treatment, rubber-like fibrin-rich plaques may develop, which can lead to life-threatening obstructions of the airway. It is recommended that laser bronchoscopy should be performed with the rigid bronchoscope. After treatment of tracheal lesion an endoscopic check must be performed within 24 hours. The combination of laser treatment and radiotherapy seems to involve a certain risk of large defects in the bronchial wall due to necrosis of the tumor.

  2. Nonablative laser treatment of facial rhytides

    Science.gov (United States)

    Lask, Gary P.; Lee, Patrick K.; Seyfzadeh, Manouchehr; Nelson, J. Stuart; Milner, Thomas E.; Anvari, Bahman; Dave, Digant P.; Geronemus, Roy G.; Bernstein, Leonard J.; Mittelman, Harry; Ridener, Laurie A.; Coulson, Walter F.; Sand, Bruce; Baumgarder, Jon; Hennings, David R.; Menefee, Richard F.; Berry, Michael J.

    1997-05-01

    The purpose of this study is to evaluate the safety and effectiveness of the New Star Model 130 neodymium:yttrium aluminum garnet (Nd:YAG) laser system for nonablative laser treatment of facial rhytides (e.g., periorbital wrinkles). Facial rhytides are treated with 1.32 micrometer wavelength laser light delivered through a fiberoptic handpiece into a 5 mm diameter spot using three 300 microsecond duration pulses at 100 Hz pulse repetition frequency and pulse radiant exposures extending up to 12 J/cm2. Dynamic cooling is used to cool the epidermis selectively prior to laser treatment; animal histology experiments confirm that dynamic cooling combined with nonablative laser heating protects the epidermis and selectively injures the dermis. In the human clinical study, immediately post-treatment, treated sites exhibit mild erythema and, in a few cases, edema or small blisters. There are no long-term complications such as marked dyspigmentation and persistent erythema that are commonly observed following ablative laser skin resurfacing. Preliminary results indicate that the severity of facial rhytides has been reduced, but long-term follow-up examinations are needed to quantify the reduction. The mechanism of action of this nonablative laser treatment modality may involve dermal wound healing that leads to long- term synthesis of new collagen and extracellular matrix material.

  3. Children acceptance of laser dental treatment

    Science.gov (United States)

    Lazea, Andreea; Todea, Carmen

    2016-03-01

    Objectives: To evaluate the dental anxiety level and the degree of acceptance of laser assisted pedodontic treatments from the children part. Also, we want to underline the advantages of laser use in pediatric dentistry, to make this technology widely used in treating dental problems of our children patients. Methods: Thirty pediatric dental patients presented in the Department of Pedodontics, University of Medicine and Pharmacy "Victor Babeş", Timişoara were evaluated using the Wong-Baker pain rating scale, wich was administered postoperatory to all patients, to assess their level of laser therapy acceptance. Results: Wong-Baker faces pain rating scale (WBFPS) has good validity and high specificity; generally it's easy for children to use, easy to compare and has good feasibility. Laser treatment has been accepted and tolerated by pediatric patients for its ability to reduce or eliminate pain. Around 70% of the total sample showed an excellent acceptance of laser dental treatment. Conclusions: Laser technology is useful and effective in many clinical situations encountered in pediatric dentistry and a good level of pacient acceptance is reported during all laser procedures on hard and soft tissues.

  4. The effect of thermal pre-treatment of titanium hydride (TiH2) powder in argon condition

    Science.gov (United States)

    Franciska P., L.; Erryani, Aprilia; Annur, Dhyah; Kartika, Ika

    2018-04-01

    Titanium hydride (TiH2) powders are used to enhance the foaming process in the formation of a highly porous metallic material with a cellular structure. But, the low temperature of hydrogen release is one of its problems. The present study, different thermal pre-treatment temperatures were employed to investigate the decomposition behavior of TiH2 to retard or delay a hydrogen gas release process during foaming. As a foaming agent, TiH2 was subjected to various heat treatments prior at 450 and 500°C during 2 hours in argon condition. To study the formation mechanism, the thermal behavior of titanium hydride and hydrogen release are investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The morphology of pre-treated titanium hydride powders were examined using Scanning Electron Microscope (SEM) while unsure mapping and elemental composition of the pre-treated powders processed by Energy Dispersive Spectroscopy (EDS). To study the phase formation was characterized by X-ray diffraction analysis (XRD). In accordance with the results, an increase in pre-treatment temperature of TiH2 to higher degrees are changing the process of releasing hydrogen from titanium hydride powder. DTA/TGA results showed that thermal pre-treatment TiH2 at 450°C, released the hydrogen gas at 560°C in heat treatment when foaming process. Meanwhile, thermal pre-treatment in TiH2 at 500°C, released the hydrogen gas at 670°C when foaming process. There is plenty of direct evidence for the existence of oxide layers that showed by EDS analysis obtained in SEM. As oxygen is a light element and qualitative proof shows that the higher pre-treatment temperature produces more and thicker oxygen layers on the surface of the TiH2 powder particles. It might the thickness of oxide layer are different from different pre-treatment temperatures, which leading to the differences in the decomposition temperature. But from SEM result that oxidation of the powder does not

  5. Induction heat treatment of laser welds

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove; Sørensen, Joakim Ilsing

    2003-01-01

    of an induction coil. A number of systematic laboratory tests were then performed in order to study the effects of the coil on bead-on-plate laser welded samples. In these tests, important parameters such as coil current and distance between coil and sample were varied. Temperature measurements were made...... the laser beam as close as possible. After welding, the samples were quality assessed according to ISO 13.919-1 and tested for hardness. The metallurgical phases are analysed and briefly described. A comparison between purely laser welded samples and induction heat-treated laser welded samples is made......In this paper, a new approach based on induction heat-treatment of flat laser welded sheets is presented. With this new concept, the ductility of high strength steels GA260 with a thickness of 1.8 mm and CMn with a thickness of 2.13 mm is believed to be improved by prolonging the cooling time from...

  6. Application of Laser Irradiation for Restorative Treatments.

    Science.gov (United States)

    Davoudi, Amin; Sanei, Maryam; Badrian, Hamid

    2016-01-01

    Nowadays, lasers are widely used in many fields of medicine. Also, they can be applied at many branches of dental practice such as diagnosis, preventive procedures, restorative treatments, and endodontic therapies. Procedures like caries removal, re-mineralization, and vital pulp therapy are the most noticeable effects of laser irradiation which has gained much attention among clinicians. With controlled and appropriate wavelength, they can help stimulating dentinogenesis, controlling pulpal hemorrhage, sterilization, healing of collagenic proteins, formation of a fibrous matrix, and inducing hard tissue barrier. Nevertheless, there are many controversies in literatures regarding their effects on the quality of bonded restorations. It hampered a wide application of lasers in some aspects of restorative dentistry and requirements to identify the best way to use this technology. The aim of this mini review is to explain special characteristics of laser therapy and to introduce the possible applications of laser devices for dental purposes.

  7. Two-photon excitation of argon

    International Nuclear Information System (INIS)

    Pindzola, P.S.; Payne, M.C.

    1982-01-01

    The authors calculate two photon excitation parameters for various excited states of argon assuming the absorption of near resonance broad-bandwidth laser radiation. Results are given for the case of two photons absorbed for the same laser beam as well as the case of absorbing photons of different frequency from each of two laser beams. The authors use multiconfiguration Hartree-Fock wave functions to evaluate the second-order sums over matrix elements. Various experimental laser schemes are suggested for the efficient excitation and subsequent ionization of argon

  8. Laser Surface Treatment of Sintered Alumina

    Science.gov (United States)

    Hagemann, R.; Noelke, C.; Kaierle, S.; Wesling, V.

    Sintered alumina ceramics are used as refractory materials for industrial aluminum furnaces. In this environment the ceramic surface is in permanent contact with molten aluminum resulting in deposition of oxidic material on its surface. Consequently, a lower volume capacity as well as thermal efficiency of the furnaces follows. To reduce oxidic adherence of the ceramic material, two laser-based surface treatment processes were investigated: a powder- based single-step laser cladding and a laser surface remelting. Main objective is to achieve an improved surface quality of the ceramic material considering the industrial requirements as a high process speed.

  9. Application of Laser Irradiation for Restorative Treatments

    OpenAIRE

    Davoudi, Amin; Sanei, Maryam; Badrian, Hamid

    2016-01-01

    Nowadays, lasers are widely used in many fields of medicine. Also, they can be applied at many branches of dental practice such as diagnosis, preventive procedures, restorative treatments, and endodontic therapies. Procedures like caries removal, re-mineralization, and vital pulp therapy are the most noticeable effects of laser irradiation which has gained much attention among clinicians. With controlled and appropriate wavelength, they can help stimulating dentinogenesis, controlling pulpal ...

  10. LASER TREATMENT OF BENIGN CUTANEOUS VASCULAR LESIONS

    Directory of Open Access Journals (Sweden)

    Uroš Ahčan

    2004-07-01

    Full Text Available Background. Congenital and acquired vascular lesions of the skin and subcutis are a common health problem from aesthetic and also from psycho-social point of view. However, recent advances in laser technology have enabled an efficient and safe treatment. This study presents our experience with treatment of cutaneous vascular lesions using modern laser systems. Most common benign cutaneous vascular lesions are described.Patients and methods. In years 2002 and 2003, 109 patients, 4 to 80 (mean 39 years old, Fitzpatrick skin type 1–4, with 210 benign cutaneous vascular lesions were treated using the Dualis VP® laser system (Fotona, Slovenia which incorporates the KTP and Nd:YAG lasers. Vascular lesions in the upper layers of the skin with diameter up to 1 mm were treated with the KTP laser (wavelength 532 nm. For larger vessels in deeper layer we used the Nd:YAG laser (wavelength 1064 nm. Patients graded the pain during treatment on a scale of 1–10. Clinical outcomes were evaluated 1–3 months after the last treatment: according to the percentage of clearance of the lesion compared to the adjacent normal skin and for the presence of adverse effects. According to these criteria each lesion was assigned a score: poor (0–25%, fair (26–50%, good (51–75%, excellent (76–100%.Results. Immediate response after application of a laser beam with proper characteristics was whitish-grey discoloration of treated area. Treatment results after 1–3 months were excellent in 48.1%, good 40.9%, fair in 8.6% and poor in 2.4%. Patients without prior anaesthesia graded pain during treatment from 1 to 8 (mean 4.0 and patients with EMLA® anaesthesia from 1 to 6 (mean 2.6. Side effects were frequent but minimal and transient. Erythema disappeared in several days after treatment while crusting persisted for 14 days. 3 permanent hyperpigmentations, 2 permanent hypopigmentations, 2 hypertrophic scars and 1 beam sized atrophic scar were detected at last follow

  11. The neuroprotective effect of hyperbaric oxygen treatment on laser-induced retinal damage in rats

    Science.gov (United States)

    Vishnevskia-Dai, Victoria; Belokopytov, Mark; Dubinsky, Galina; Nachum, Gal; Avni, Isaac; Belkin, Michael; Rosner, Mordechai

    2005-04-01

    Retinal damage induced by mechanical trauma, ischemia or laser photocoagulation increases considerably by secondary degeneration processes. The spread of damage may be ameliorated by neuroprotection that is aimed at reducing the extent of the secondary degeneration and promote healing processes. Hyperbaric oxygen (HBO) treatment consists of inspiration of oxygen at higher than one absolute atmospheric pressure. Improved neural function was observed in patients with acute brain trauma or ischemia treated with HBO. This study was designed to evaluate the neuroprotective effect of hyperbaric oxygen (HBO) on laser induced retinal damage in a rat model. Standard argon laser lesions were created in 25 pigmented rats divided into three groups: Ten rats were treated immediately after the irradiation with HBO three times during the first 24 hr followed by 12 consecutive daily treatments. Five rats received a shorter treatment regimen of 10 consecutive HBO treatments. The control group (10 rats) underwent the laser damage with no additional treatment. The retinal lesions were evaluated 20 days after the injury. All outcome measures were improved by the longer HBO treatment (Ptreatment was less effective, showing an increase only in nuclei density at the central area of lesion (Pretinal damage in a rat model. In the range of HBO exposures studied, longer exposure provides more neuroprotection. These results encourage further evaluation of the potential therapeutic use of hyperbaric oxygen in diseases and injuries of the retina.

  12. Broadband Ftmw Spectroscopy of the Urea-Argon and Thiourea-Argon Complexes

    Science.gov (United States)

    Medcraft, Chris; Bittner, Dror M.; Cooper, Graham A.; Mullaney, John C.; Walker, Nick

    2017-06-01

    The rotational spectra complexes of argon-urea, argon-thiourea and water-thiourea have been measured by chirped-pulse Fourier transform microwave spectroscopy from 2-18.5 GHz. The sample was produced via laser vaporisation of a rod containing copper and the organic sample as a stream of argon was passed over the surface and subsequently expanded into the vacuum chamber cooling the sample. Argon was found to bind to π system of the carbonyl bond for both the urea and thiourea complexes.

  13. [Laser biostimulation in the treatment of pleurisy].

    Science.gov (United States)

    Milojević, Momir; Kuruc, Vesna

    2003-01-01

    Low-intensity lasers have been utilized in medicine in two ways: for local stimulation and for stimulation of acupuncture points. Literature data reveal that this method has been indiscriminately applied in psychiatry, rheumatology, gynecology, dermatology, otorhinolaryngology, in diverse acute and chronic pains, inflammations, vascular disorders, angina pectoris, bronchial asthma. Most commonly reported clinical effects are analgesia, spasmolytic and anti-inflammatory effects, as well as faster wound and bone healing. This prospective study analyses effects of laser biostimulation on patients with pleurisy. The analysis included 25 patients treated at the Institute of Lung Diseases in Sremska Kamenica during 2000, 2001 and 2002. Apart from conservative treatment, these patients were treated with laser biostimulation of acupuncture points and local region for ten days. During treatment, changes of present clinical signs, general symptoms, radiological findings, as well as changes of some relevant biochemical parameters were recorded. Results were compared with the control group which included the same number of patients, who differed from the examined group only by not being exposed to laser biostimulation. The examined group of patients with pleuritis presented with quicker resorption of pleural effusion, less pleural adhesions, more significant decrease of clinical symptoms, especially pain, as well as more significant increase of cortisol and immunoglobulin A and decrease of circulating immune complexes (CIC), leukocytes and sedimentation rate than the control group. Mechanisms of laser biostimulation in treatment of pleurisy were described in detail and the obtained results were correlated to those reported by other authors. 1. Patients with pleurisy undergoing laser stimulation presented with faster resorption of effusion and remission of the subjective symptoms, as well as significant decrease of biochemical acute inflammation parameters in the peripheral

  14. Endoscopic Laser Treatment for Rectosigmoid Villous Adenoma: Factors Affecting the Results

    Directory of Open Access Journals (Sweden)

    JM Brunetaud

    1992-01-01

    Full Text Available Endoscopic laser treatment is now commonly used for palliation of advanced digestive cancers in nonsurgical candidates. lt has also been used for treatment of benign rectosigmoid villous adenoma. The present work reports the long term results in 387 patients with benign rectosigmoid villous adenomas revealed by biopsy. Patients included 39% who had contraindications to surgery, 19% who had a tumour recurrence after a nonlaser treatment, 41 % for whom surgical resection appeared to be too drastic for a tumour found benign on biopsy, and 1 % who refused surgery. Two types of wavelength were used: the 1.06 µm infrared light from the Nd:YAG laser and the green light from the argon laser or the Nd:YAG frequency doubled laser. In some patients, both wavelengths were used. Treatment was completed in 343 patients. Total tumour destruction was achieved in 92.8% of patients, a carcinoma was detected in 6.4% on biopsy specimens obtained during laser treatment and benign villous tissue persisted in 0.8%. During the average 30-month follow-up period of the patients with total tumour destruction , 16% had a recurrence. Treatment was well-tolerated with a complication race of 2.3% (one patient with a perforation, one with hemorrhage and seven with stenosis requiring dilation. Circumferential extension of the tumour base was the only factor affecting the duration of treatment, the rate of cancers detected during treatment and the rate of complications. Recurrence rate after initial treatment was higher in patients treated for a recurrence after a previous nonlaser treatment than in patients treated only by laser (P<0.01. It was also higher when the initial histology showed low grade dysplasia as opposed to high grade dysplasia (P<0.01 and when the tumour was located in the lower or middle rectum rather than in the upper rectum or sigmoid (P<0.01. Direct cost of laser treatments was estimated to be 28 to 40% of the surgery charges for lesions of identical size

  15. [Argon plasma coagulation combined with cryotherapy via bronchoscopy for the treatment of one child with severe post-intubation tracheal stenosis and literature review].

    Science.gov (United States)

    Zhou, Kuo; Liang, Jun; Cui, Ai-hua; Fu, Ai-xia; Yang, Qiao-zhi

    2013-10-01

    To observe the short term effect of argon plasma coagulation (APC) combined with cryotherapy via bronchoscopy for treatment of severe post-intubation tracheal stenosis in a child. A 3-year old boy was admitted for cephalothorax abdominal compound trauma and dyspnea, who had severe post-incubation tracheal stenosis. The agreement about the operation risk was signed by the parents. Endotracheal APC procedure was performed with a bronchoscope under general anesthesia. The APC probe was put into the working channel of the bronchoscope. The stenotic lesion was endoscopically visualized and then coagulated by argon plasma. Such coagulation was carried out several times at the stenotic site until it gradually became dilated. The devitalized tissue was mechanically removed with grasping forceps. Thereafter, bronchoscopic cryosurgery was repeatedly performed at the stenotic site. Clinical symptoms, signs and bronchoscopic manifestations were observed right after operation, after 1 day, 10 days, 1 month and 6 months separately. Tracheal tissue hyperplasia and cyanosis disappeared, laryngeal stridor and dyspnea improved obviously right after the operation. General condition of the patient was well, there was no laryngeal stridor and dyspnea 10 days after operation. The mucosa of the surgical site was smooth and no tracheostenosis was seen under bronchoscope at 1 month and 6 months after the operation. Argon plasma coagulation combined with cryotherapy via bronchoscope is an effective method to treat tracheal stenosis of children, which needs further exploration for the application.

  16. Functional Changes of Dendritic Cells in C6 Glioma-Bearing Rats That Underwent Combined Argon-Helium Cryotherapy and IL-12 Treatment.

    Science.gov (United States)

    Li, Ming; Cui, Yao; Li, Xiqing; Guo, Yanwu; Wang, Bin; Zhang, Jiadong; Xu, Jian; Han, Shuangyin; Shi, Xiwen

    2016-08-01

    The aim of this study was to explore changes in tumor tissues of glioma-bearing rats that underwent argon-helium cryoablation as well as changes in antitumor immunity before and after combined interleukin 12 treatment. Two hundred sixty Wistar rats were randomly divided into a blank control group, intravenous injection interleukin-12 group, cryotherapy group, and cryotherapy + intravenous injection group. C6 glioma cells proliferated in vitro were implanted subcutaneously on the backs of rats to establish C6 glioma-bearing animal models. Each group underwent the corresponding treatments, and morphological changes in tumor tissues were examined using hematoxylin-eosin staining. CD11c staining was examined using immunohistochemistry, and differences in dendritic cells and T-cell subsets before and after treatment were analyzed using flow cytometry. The control group showed no statistical changes in terms of tumor tissue morphology and cellular immunity, cryotherapy group, and cryotherapy + intravenous injection group, among which the count for the cryotherapy + intravenous injection group was significantly higher than those of all other groups. In the argon-helium cryotherapy group, tumor cells were damaged and dendritic cell markers were positive. The number of CD11c+ and CD86+ cells increased significantly after the operation as did the cytokine interferon-γ level (P < .01), suggesting a shift toward Th1-type immunity. Combined treatment of argon-helium cryoablation and interleukin 12 for gliomas not only effectively injured tumor tissues but also boosted immune function and increased antitumor ability. Therefore, this approach is a promising treatment measure for brain gliomas. © The Author(s) 2015.

  17. Influence of matrices on electron temperature of laser micro-plasma in argon atmosphere at reduced pressure

    International Nuclear Information System (INIS)

    Guo Qinlin; Zhou Yulong; Zhang Bo; Zhang Qiulin; Zhang Jinping; Huai Sufang

    2007-01-01

    Laser micro-spectral analysis coupled with CCD spectrometer was used in this experiment. With Fe I 356.54 nm and Fe I 358.12 nm as analysis spectral lines, the micro-plasma temperature and its spatial distribution were investigated in different matrices, namely Mg, Al, Si, and steel alloy6-0. The electron temperature as a function of location in each matrix and the differences of that at the same location in different matrices were determined and an explanation was given. Finally, with Cu I 324.75 nm and Zn I 394.50 nm as analysis spectral lines, we have successfully used the calculated micro-plasma temperature to discuss the matrix effect. (authors)

  18. Influence of argon/oxygen atmospheric dielectric barrier discharge treatment on desizing and scouring of poly (vinyl alcohol) on cotton fabrics

    International Nuclear Information System (INIS)

    Peng Shujing; Gao Zhiqiang; Sun Jie; Yao Lan; Qiu Yiping

    2009-01-01

    The effect of argon/oxygen atmospheric dielectric barrier discharge (DBD) treatment on desizing and scouring of polyvinyl alcohol (PVA) on cotton fabric was studied with respect to the treatment duration of 1, 2, 4 and 6 min. X-ray photoelectron spectroscopy (XPS) analysis indicated that oxygen concentration increased for the plasma treated PVA film. Solubility measurement revealed that plasma treatment increased PVA solubility in hot washing but less effective in cold washing. Scanning electron microscopy (SEM) showed that the fiber surfaces were as clean as unsized fibers after 6 min treatment followed by hot washing. Wickability analysis indicated that the capillary heights of plasma treated fabrics increased significantly as the plasma treatment duration increased. The results of the yarn tensile strength test showed that the plasma treatment did not have a negative effect on fabric tensile strength.

  19. Treatments of the oral leukoplakia by laser

    Science.gov (United States)

    Capocci, M.; Mohsen, M.; Lo Giudice, R.; Del Vecchio, A.; Gaimari, G.; Tribolati, L.; Palaia, G.; Romeo, U.

    2016-03-01

    Oral leukoplakia is catalogued under the group of "potentially malignant disorders". In daily practice, the World Health Organization definition "white patch or plaque that cannot be characterized clinically or histologically as any other disease" is completed by including the observation that it cannot be removed by simple scraping, thereby distinguishing it from pseudo-membranous candidiasis. The aim of this study is to find a definitive treatment of oral leukoplakia, because of its recurrence and its potentiality to the malignant transformation. There are currently different approaches to oral leukoplakia: scalpel surgery, systemic therapy (carotenoids, vitamins, etc.), electro-cauterization, cryotherapy and the use of the laser. In every lesion, biopsy and histological analysis has been performed to identify the stage and classification of the oral leukoplakia. Laser can be used for the complete excision of the lesion (which is more effective, but also more invasive), for the photodynamic therapy (non-invasive procedure, which requires several applications) or for the vaporization of the lesion (very precise treatment and relatively easy to perform). Laser treatments have shown better healing, less soft tissues retraction and less post-operative pain, comparing with traditional surgery. The use of systemic therapies and smoking habit interruption (where present) has been also useful to reduce the lesions before the clinical treatments. The treatment has always to be supported by histological analysis to identify the risk and consequently planning the clinical approach.

  20. Laser therapy in the periodontitis treatment

    International Nuclear Information System (INIS)

    Pinto Nancassa, Raul; Quintana Gonzalez, Julio; Rodriguez de Bernardo, Carlos; Hernandez Cruz, Hector; Hernandez Alvarez, Victor

    2009-01-01

    We performed a controlled clinical trial to evaluate the efficacy of low-power laser surgery combined with parodontal in the treatment of periodontitis in patients undergoing surgical treatment for this condition in the municipality of Moron North Clinic from February to July 2006. The world of work consisted of all patients diagnosed with periodontitis in this period of time were operated on at the Clinic of North County Moron (N = 86), leaving the sample for 80 patients. In patients where surgery was applied parodontal combined with low power laser radiation pain appeared in only a small number of cases 48 hours and none required the use of analgesics. For seven days the largest percentage of individuals submitted a total healing of soft tissue. No side effects to treatment. Patients treated with surgery parodontal, in whole required the use of analgesics in the first 24 hours and even at 72 hours after surgery in some patients, the seven days the number of patients with partial healing of the soft tissues was although the prevailing high total healing. There was no bone gain, the patients were stable, resulting in only stop. Statistically significant differences were found between groups suggesting that allowing the treatment of low-power laser in the surgery of periodontitis as well as being easy to apply proved to be effective. (Author)

  1. Endoscopic laser treatment of glottic carcinoma

    International Nuclear Information System (INIS)

    Peretti, G.; Cappiello, J.; Renaldini, G.; Antonelli, A.R.; Villanacci, V.; Marocolo, D.

    1992-01-01

    Histological diagnosis of laryngeal epithelial abnormalities may range from mucosal aberration, without risk of progressing into invasive neoplasm, to in situ or invasive carcinoma. Precise identification of epithelial abnormalities of laryngeal mucosa requires biopsy and microscopic evaluation. Random biopsies are frequently inadequate, since they are not representative for the entire lesion. Excisional Biopsy, allowing removal of lesion together with a rim of healthy tissue is ideal for both diagnosis and treatment. If completely removed, the cancer should not require further treatment; if the margins are not free of disease, re-excision or radiotherapy is considered as alternative options. Laser excision represents an extension of the clinical application of endoscopy, allowing the laryngologist to perform an accurate and bloodless surgery. Endoscopic laser treatment for selected glottic SCC (squamous cell carcinoma) has been shown to provide an excellent alternative to radiotherapy or open neck surgery in terms of cure rate and functional results. Preliminary results are presented with the purpose of stressing the role of EB with CO2 laser in diagnosis and treatment of selected glottic carcinoma. (author). 16 refs

  2. In vitro comparative study of share bond of light cured composite resins with halogen light and argon laser, using stainless steel brackets on human premolars; Estudo comparativo in vitro da capacidade adesiva da resina fotoativada pela luz halogena e por laser de argonio, utilizando-se brackets metalicos em pre-molares humanos

    Energy Technology Data Exchange (ETDEWEB)

    Carillo, Vitoria Eugenia Bismarck

    2004-07-01

    The aim of this study in vitro was to compare the share bond strength of the light-cured composite resins Transbond XT (Unitek), with halogen light and argon laser. The Adhesive Remmant Index (ARI) was also investigated. The brackets Dyna lock (3M-UNITEK) were bonded to 75 human premolars, divided into 5 groups (15 each) according to time and the polymerization: Group H20, 15 brackets bonded with halogen light for 20s (10s both sides); Group H40, 15 brackets bonded with halogen light for 40s (20s both sides); Group A40, 15 brackets bonded with argon laser for 40s (20s both sides); Group A20, 15 brackets bonded with argon laser for 20s (10s both sides); Group A10, 15 brackets bonded with argon laser for 10s (5s both sides). The pulpal temperature changes were determined during a polymerization, not exceeding 3,5 deg C. After bonding, the teeth were submitted to a thermo cycled of 700 cycles between 5 deg C and 55 deg C, to simulate the consuming that the light cured composite resin would have in a short space of time. The specimens were then placed in PVC ring and embedded in acrylic resin (Aero-Jet). The tensile bond strength test was performed on an Universal Machine set at a crosshead speed of 1,5 mm/min, and for each rupture we registered a graphic and the best load required in Newtons, was converted to MPa and kgf. The share bond strength showed bigger values for the exposure time of 20 seconds, for the Group bonded for halogen light (H20), 7,45 kgf (7,64 MPa) and for argon laser 7,50 kgf (7,69 MPa); lesser values for the exposure time of 40s for the Group with halogen light (H40), 6,15 kgf (6,30 MPa) and argon laser Group (A40), 6,20 kgf (6,35 MPa) 0; and A10, 4,85 kgf (4,97 MPa). In the ARI Index, only A40 Group showed the 1 Index, with statistical results. In this Group, less than half of the remainder adhesive stayed on the surface of the enamel, conferring specimens failed at the enamel-adhesive interface. The results of the in vitro study demonstrate that

  3. Alpha alumina synthesis by laser treatment of bi-phasic nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Aktas, Cenk, E-mail: cenk.aktas@inm-gmbh.de [Leibniz Institute for New Materials, D2 2 Campus, 66123 Saarbrücken (Germany); Lee, Juseok; Míro, Marina Martinez [Leibniz Institute for New Materials, D2 2 Campus, 66123 Saarbrücken (Germany); Barnoush, Afrooz [Norwegian University of Science and Technology, Trondheim (Norway); Saarland University, D2 2 Campus, 66123 Saarbrücken (Germany); Veith, Michael [Leibniz Institute for New Materials, D2 2 Campus, 66123 Saarbrücken (Germany)

    2013-08-01

    Al/Al{sub 2}O{sub 3} bi-phasic nanowires (Al-core/Al{sub 2}O{sub 3} shell) are prepared by chemical vapor deposition (CVD) using single source precursor (SSP) approach. Such bi-phasic nanostructures were heat-treated using an argon laser operating at visible wavelengths. Al core seems to act as an active binder, which might decrease the inhomogeneous heating and thermal gradients. Nanoindentation method is used to estimate the hardness of the laser treated surfaces. Hardness values and pop-in behaviour in loading-curve indicate a formation of α-Al{sub 2}O{sub 3} with very low defect density. It is believed that Al/Al{sub 2}O{sub 3} bi-phasic layers exhibit a dynamic change by transforming into alumina after the laser irradiation and this leads to alteration of the optical absorption especially in the visible wavelength region. Following the full transformation to alumina, the surface reflects back the laser light which hinders inhomogeneous and excessive heating. In this context, laser treatment of Al/Al{sub 2}O{sub 3} bi-phasic nanowires provides a controlled sintering process which can open up various applications in different fields.

  4. UV excimer laser and low temperature plasma treatments of polyamide materials

    Science.gov (United States)

    Yip, Yiu Wan Joanne

    Polyamides have found widespread application in various industrial sectors, for example, they are used in apparel, home furnishings and similar uses. However, the requirements for high quality performance products are continually increasing and these promote a variety of surface treatments for polymer modification. UV excimer laser and low temperature plasma treatments are ideally suited for polyamide modification because they can change the physical and chemical properties of the material without affecting its bulk features. This project aimed to study the modification of polyamides by UV excimer laser irradiation and low temperature plasma treatment. The morphological changes in the resulting samples were analysed by scanning electron microscopy (SEM) and tapping mode atomic force microscopy (TM-AFM). The chemical modifications were studied by x-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and chemical force microscopy (CFM). Change in degree of crystallinity was examined by differential scanning calorimetry (DSC). After high-fluence laser irradiation, topographical results showed that ripples of micrometer size form on the fibre surface. By contrast, sub-micrometer size structures form on the polyamide surface when the applied laser energy is well below its ablation threshold. After high-fluence laser irradiation, chemical studies showed that the surface oxygen content of polyamide is reduced. A reverse result is obtained with low-fluence treatment. The DSC result showed no significant change in degree of crystallinity in either high-fluence or low-fluence treated samples. The same modifications in polyamide surfaces were studied after low temperature plasma treatment with oxygen, argon or tetrafluoromethane gas. The most significant result was that the surface oxygen content of polyamide increased after oxygen and argon plasma treatments. Both treatments induced many hydroxyl (-OH) and carboxylic acid (-COOH

  5. Laser tattoo removal with preceding ablative fractional treatment

    Science.gov (United States)

    Cencič, Boris; Možina, Janez; Jezeršek, Matija

    2013-06-01

    A combined laser tattoo removal treatment, first the ablative fractional resurfacing (AFR) with an Er:YAG laser and then the q-switched (QSW) Nd:YAG laser treatment, was studied. Experiments show that significantly higher fluences can be used for the same tissue damage levels.

  6. Laser treatment of oral vascular malformations

    Science.gov (United States)

    Romeo, U.; Gaimari, G.; Mohsen, M.; Tenore, G.; Palaia, G.

    2014-01-01

    Oral Vascular Malformations (OVM) are congenital anomalies characterized by morph-structural and/or functional changes of nature in severity and extension. OVM can affect any type of vessels arterial, venous or lymphatic and any capillary or anatomical. They are divided into two categories: low and high flow. In this study were treated 40 patients with OVM with a range size from 2 mm to 44 mm; they were subjected to clinical examination supported by Colour-Doppler Ultrasound instrumental examination and only for doubt cases the Magnetic Resonance Imaging (MRI) was prescribed. Only low flow venous and capillary malformations were treated by GaAlAs laser (Wiser®, Lambda, Brindole,Italy, 980nm) and KTP laser (SmartLite®, DEKA, Florence, Italy, 532nm) with two different techniques: the Transmucosal Thermophotocoagulation (TMT) and the Intralesional Photocoagulation (ILP). These techniques permitted a good control of haemostasis, avoiding bleeding both during surgery and in the postoperative. It is obtained an excellent and good healing respectively in 10% and 60% of cases, a moderate and poor resolution respectively in 22.5% and 7.5% of cases. A clear diagnosis allowed the management of Venous malformations (VM) by laser devices with wavelengths highly absorbed in haemoglobin in safety and efficacy and according to the principles of minimal invasive surgery. The aim of this study was to verify if the laser is effective in the treatment of OVM for the purpose of the clinical findings and the postoperative course. The Authors concluded that the laser can be considered the "gold standard" for treating OVM.

  7. Laser Treatment of Tattoos: Basic Principles.

    Science.gov (United States)

    Bäumler, Wolfgang

    2017-01-01

    Tattooing has become very popular worldwide during the past decades, and millions of people have one or many tattoos at different anatomical sites. The color of tattoos is mainly black, followed by red, green, blue, and other colors. A part of the tattooed people regret tattooing or have permanent problems with tattoos and therefore seek for tattoo removal. Tattoos consist of solid pigment particles in the skin. Thus, tattoo removal requires fragmentation of these permanently incorporated particles. The gold standard of tattoo removal is laser therapy. Short light pulses at high intensities are applied to the tattooed skin surface. The laser light penetrates the skin and is selectively absorbed in the pigment particles. The absorbed laser light leads to heat-up and fragmentation of the particles. Due to the complex chemistry of the various tattoo pigments, the efficacy of this fragmentation process is frequently unpredictable. Due to the short and intense pulses, nonlinear effects of light and thermal properties of tattoo particles may play a role, and the assumptions of selective photothermolysis may not reflect the real process of tattoo particle fragmentation as a whole. In case fragmentation occurs, the concentration of pigment particles in the skin decreases, yielding a fading of the tattoo color in the skin. Laser therapy is most effective in black tattoos and less effective for colored tattoos. The rate of side effects is low due to the selectivity of the treatment. Laser light may change the chemistry of the tattoo pigments and hence provoke toxic decomposition products. © 2017 S. Karger AG, Basel.

  8. Krypton red laser photocoagulation of the ocular fundus. 1982.

    Science.gov (United States)

    Yannuzzi, Lawrence A; Shakin, Jeffrey L

    2012-02-01

    The theoretical rationale, the histopathologic evidence, and the preliminary clinical studies related to krypton red laser (KRL) photocoagulation of the ocular fundus are reviewed. The authors report on their experience with currently available laser systems using this wavelength (647.1 nm) for photocoagulation of retinal vascular proliferative diseases and chorioretinal diseases associated with exudative manifestations. A histopathologic and clinical comparison of argon blue-green laser (ABGL), the pure argon green laser (AGL), and the krypton yellow laser (KYL), with reference to photocoagulation treatment of the ocular fundus is also discussed.

  9. Laser in caries treatment--patients' experiences and opinions.

    Science.gov (United States)

    Sarmadi, R; Hedman, E; Gabre, P

    2014-02-01

    The aim of this study was to obtain a deeper understanding of patient's experiences and perspectives after dental caries treatment with Er:YAG laser technology. Twelve patients aged 15-30 years who had undergone at least one laser caries excavation agreed to participate in an interview study. All the interviews were tape recorded and transcribed by a transcription agency. The transcribed texts were analysed using manifest and latent qualitative content analysis. The categories in this study were identified as choosing laser, understanding laser, encouraging dental care and my oral health. The motivation for laser treatment was described as dental fear in general, specific fear of needles or discomfort with the drill. The informants described the dentist's role as initiators of treatment and willing or unwilling facilitators. Laser treatment was described as safer and more carefully considered treatment. They felt generally safe with laser and were able to relax during the treatment. All interviewers described a positive impression of the laser, and words like 'up to date' and 'future-oriented' were used to describe laser. Laser treatment was considered less painful. The results indicate that patients find laser a feasible and convenient treatment option. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Cicatrização da membrana timpânica na timpanocentese com laser de argônio comparado à técnica com microlanceta: estudo experimental em ratos Tympanic membrane healing in myringotomies performed with argon laser or microknife: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Lucio Almeida Castagno

    2006-12-01

    Full Text Available Otite média secretora (OMS e otite média aguda recorrente (OMAR podem necessitar tratamento cirúrgico para adequada ventilação da orelha média. A abertura clássica do tímpano (timpanocentese requer incisão por microlanceta sob controle de microscópio cirúrgico e mantém-se patente por alguns dias. Estudos recentes sugerem que a timpanocentese feita por diferentes lasers pode permanecer permeável por maior tempo, o que possibilitaria a normalização da otite média. MATERIAL E MÉTODOS: Neste estudo experimental 34 ratos linhagem Wistar, albinos, machos adultos pesando cerca de 300g, foram anestesiados com cetamina 27 mg/kg e xilazina 2,7 mg/kg. A seguir, foram submetidos à timpanocentese incisional com microlanceta no ouvido direito (ML-OD, e à timpanocentese mediada por laser de argônio no ouvido esquerdo (LA-OE. RESULTADOS: Não houve diferença significativa no tempo de cicatrização das timpanocenteses feitas com laser de argônio ou microlanceta. Todas as timpanocenteses cicatrizaram em 10 dias. CONCLUSÃO: A timpanocentese com laser de argônio apresentou patência e cicatrização semelhantes à técnica clássica com microlanceta realizada em ratos Wistar sem enfermidades de orelha média.Secretory otitis media (SOM and recurrent acute otitis media (RAOM may require surgical treatment to proper ventilate the middle ear. Incisional myringotomy is usually done under microscopy with a micro-knife , but it remains patent for just a few days. Recent research indicates that laser assisted myringotomies remain open much longer, allowing middle ear ventilation and healing. MATERIAL AND METHODS: In this experimental study 34 white, male, adult, Wistar rats, without middle ear disease were submited to anesthesia with ketamine 27 mg/kg and xylazine 2,7 mg/kg. Incisional myringotomy was done on the right ear, while laser myringotomy was done on the left. Myringotomies were evaluated periodically until healing. RESULTS: The healing

  11. Dynamics of imploding argon plasmas

    International Nuclear Information System (INIS)

    Clark, W.; Richardson, R.; Brannon, J.; Wilkinson, M.; Katzenstein, J.

    1982-01-01

    The BLACKJACK 5 pulse generator has been used to implode annular argon plasmas to form dense Z pinches. Visible streak photography, framing photography, and laser shadowgraphy were used to observe the radial position and velocity of the plasmas as they imploded. The measured position and velocity of the imploding plasmas have been compared with the results of calculations based on a one-dimensional snowplow model. Good agreement is obtained between the snowplow calculations and the optical measurements. Empirically determined optimum implosion parameters are also found to agree with those predicted by the model

  12. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  13. The Effect of Laser Surface Treatment on Structure and Mechanical Properties Aluminium Alloy ENAC-AlMg9

    Directory of Open Access Journals (Sweden)

    Pakieła W.

    2016-09-01

    Full Text Available In this work, the influence of a high power diode laser surface treatment on the structure and properties of aluminium alloy has been determined. The aim of this study was to improve the mechanical and tribological properties of the surface layer of the aluminium alloy by simultaneously melting and feeding tungsten carbide particles into the molten pool. During the process was used high-power diode laser HPDL. In order to remelt the aluminium alloy surface the HPDL laser of 1.8, 2.0 and 2.2 kW laser beam power has been used. The linear laser scan rate of the beam was set 0.5 cm/s. In order to protect the liquid metal during laser treatment was used argon. As a base material was used aluminium alloy ENAC-AlMg9. To improve the surface mechanical and wear properties of the applied aluminium alloy was used biphasic tungsten carbide WC/W2C. The size of alloying powder was in the range 110-210 µm. The ceramic powder was introduced in the remelting zone by a gravity feeder at a constant rate of 8 g/m.

  14. Volumetric optoacoustic monitoring of endovenous laser treatments

    Science.gov (United States)

    Fehm, Thomas F.; Deán-Ben, Xosé L.; Schaur, Peter; Sroka, Ronald; Razansky, Daniel

    2016-03-01

    Chronic venous insufficiency (CVI) is one of the most common medical conditions with reported prevalence estimates as high as 30% in the adult population. Although conservative management with compression therapy may improve the symptoms associated with CVI, healing often demands invasive procedures. Besides established surgical methods like vein stripping or bypassing, endovenous laser therapy (ELT) emerged as a promising novel treatment option during the last 15 years offering multiple advantages such as less pain and faster recovery. Much of the treatment success hereby depends on monitoring of the treatment progression using clinical imaging modalities such as Doppler ultrasound. The latter however do not provide sufficient contrast, spatial resolution and three-dimensional imaging capacity which is necessary for accurate online lesion assessment during treatment. As a consequence, incidence of recanalization, lack of vessel occlusion and collateral damage remains highly variable among patients. In this study, we examined the capacity of volumetric optoacoustic tomography (VOT) for real-time monitoring of ELT using an ex-vivo ox foot model. ELT was performed on subcutaneous veins while optoacoustic signals were acquired and reconstructed in real-time and at a spatial resolution in the order of 200μm. VOT images showed spatio-temporal maps of the lesion progression, characteristics of the vessel wall, and position of the ablation fiber's tip during the pull back. It was also possible to correlate the images with the temperature elevation measured in the area adjacent to the ablation spot. We conclude that VOT is a promising tool for providing online feedback during endovenous laser therapy.

  15. Laser tumor treatment in oral and maxillofacial surgery

    Science.gov (United States)

    Neukam, F. W.; Stelzle, F.

    Cancer treatment is an integral part of oral and maxillofacial surgery. Oral cancer in particular is a highly prevalent neoplasm. Standard treatment for most of the tumors is radical surgery combined with stage-based neo-/adjuvant therapy. Laser surgery has become a reliable treatment option for oral cancer as well as for precancerous lesions. Widely used lasers in oral and maxillofacial tumor surgery are the CO2 laser, the Er:YAG laser, the Nd:YAG laser and the KTM laser. The use of lasers in tumor surgery has several advantages: remote application, precise cutting, hemostasis, low cicatrization, reduced postoperative pain and swelling, can be combined with endoscopic, microscopic and robotic surgery. However, laser surgery has some major drawbacks: In contrast to conventional incisions with scalpels, the surgeon gets no feedback during laser ablation. There is no depth sensation and no tissue specificity with a laser incision, increasing the risk of iatrogenic damage to nerves and major blood vessels. Future prospects may solve these problems by means of an optical feedback mechanism that provides a tissue-specific laser ablation. First attempts have been made to perform remote optical tissue differentiation. Additionally, real time optical tumor detection during laser surgery would allow for a very precise and straight forward cancer resection, enhancing organ preservation and hence the quality of life for patients with cancer in the head and neck region.

  16. Preliminary Report On Combined Surgical- And Laser-Treatment Of Large Hemangiomas And Tattoos

    Science.gov (United States)

    Ginsbach, G.

    1981-05-01

    As most hemangiomas and tattoos require many sessions to be cured completely by argon-laser or conventional therapy I developed a new combined surgical and laser-therapy method for large hemangiomas and tattoos. This is a three step method. First: The skin lesion is treated by argon-laser with the point by point method, developed by ourself. Second: Under local or general anaesthesia a) the hemangioma is partially excised and undermined letting only the skin which is already treated by argon-laser-beams. Than the hemangioma is exstirpated in toto, the wound closed by running intradermal sutures and a pressure bandage applied, b) the tattoo is abraded as deep as possible, draped by lyofoam. Then a pressure bandage is applied. Third: The hemangioma as well as the tattoo are treated by argon-laser-beams after the operation. This method is safe and effective, gives good results, minimal scars in the case of hemangiomas and tattoos. In this paper the method is described and some cases are illustrated by pre- and postoperational photographs.

  17. Laser treatment of infantile hemangioma: A systematic review.

    Science.gov (United States)

    Chinnadurai, Sivakumar; Sathe, Nila A; Surawicz, Tanya

    2016-03-01

    To systematically review studies of laser treatment of infantile hemangioma (IH). We searched multiple databases including MEDLINE® and EMBASE from 1982 to June 2015. Two investigators independently screened studies against predetermined criteria and extracted key data. Investigators independently assessed study risk of bias and the strength of the evidence of the body of literature. We identified 29 studies addressing lasers: 4 randomized controlled trials, 8 retrospective cohort studies, and 17 case series. Lasers varied across studies in type, pulse width, or cooling materials. Most comparative studies (n = 9) assessed variations of pulsed dye laser (PDL) and examined heterogeneous endpoints. Most studies reported on treatment of cutaneous lesions. Overall, longer pulse PDL with epidermal cooling was the most commonly used laser for cutaneous lesions; Nd:YAG was the most commonly used intralesionally. Most studies reported a higher success rate with longer pulse PDL compared with observation in managing the size of IH, although the magnitude of effect differed substantially. CO2 laser was used for subglottic IH in a single study, and was noted to have a higher success rate and lower complication rate than both Nd:YAG and observation. Studies comparing laser with β-blockers or in combination with β-blockers reported greater improvements in lesion size in combination arms versus β-blockers alone and greater effects of lasers on mixed superficial and deep IH. Strength of the evidence for outcomes after laser treatments ranged from insufficient to low for effectiveness outcomes. Strength of the evidence was insufficient for the effects of laser compared with β-blockers or in combination with β-blockers as studies evaluated different agents and laser types. Studies assessing outcomes after CO2 and Nd:YAG lasers typically reported some resolution of lesion size, but heterogeneity among studies limits our abilities to draw conclusions. Studies of laser

  18. Micropulse diode laser trabeculoplasty -- 180-degree treatment.

    Science.gov (United States)

    Rantala, Elina; Välimäki, Juha

    2012-08-01

    To evaluate the outcome of 180° micropulse diode laser trabeculoplasty (MDLT) in patients with open-angle glaucoma. A retrospective review of 40 eyes of 29 MDLT-treated patients with a minimum follow-up time of 6 months. Successful outcome was defined as follows: (i) a ≥20% or (ii) a ≥3-mmHg decrease of intraocular pressure (IOP), no further need for laser- or incisional surgery and the number of glaucoma medication was the same or less than preoperative. These definitions will from now on be referred to as definition one and definition two. Life-table analysis showed an overall success rate of 2.5% (1/40) and 7.5% (3/40) (according to definitions one and two, respectively) after up to 19 months of follow-up. The average time for failure was by definition one 2.9 months (standard deviation, SD ± 3.5, range 1-12 months) and by definition two 3.3 months (SD ± 3.9, range 1-16 months). There were no intra- or postoperative complications caused by MDLT. Postoperative inflammatory reaction, cells and flare, was scanty. Our results suggest that 180° MDLT is a safe but ineffective treatment in patients with open-angle glaucoma. © 2010 The Authors. Acta Ophthalmologica © 2010 Acta Ophthalmologica Scandinavica Foundation.

  19. Diode laser heat treatment of lithium manganese oxide films

    International Nuclear Information System (INIS)

    Pröll, J.; Kohler, R.; Mangang, A.; Ulrich, S.; Bruns, M.; Seifert, H.J.; Pfleging, W.

    2012-01-01

    The crystallization of lithium manganese oxide thin films prepared by radio frequency magnetron sputtering on stainless steel substrates under 10 Pa argon pressure is demonstrated by a laser annealing technique. Laser annealing processes were developed as a function of annealing time and temperature with the objective to form an electrochemically active lithium manganese oxide cathode. It is demonstrated, that laser annealing with 940 nm diode laser radiation and an annealing time of 2000 s at 600 °C delivers appropriate parameters for formation of a crystalline spinel-like phase. Characteristic features of this phase could be detected via Raman spectroscopy, showing the characteristic main Raman band at 627 cm -1 . Within cyclic voltammetric measurements, the two characteristic redox pairs for spinel lithium manganese oxide in the 4 V region could be detected, indicating that the film was well-crystallized and de-/intercalation processes were reversible. Raman post-analysis of a cycled cathode showed that the spinel-like structure was preserved within the cycling process but mechanical degradation effects such as film cracking were observed via scanning electron microscopy. Typical features for the formation of an additional surface reaction layer could be detected using X-ray photoelectron spectroscopy.

  20. Laser treatment of otitis media in children

    Energy Technology Data Exchange (ETDEWEB)

    Podoynitsyna, L.F.

    1984-08-01

    Clinical trials were conducted with the helium-neon LG-75 laser (632.8 nm, 0.1 W/cm/sup 2/) in the management of 50 children with acute and chronic otitis media. The sessions consisted of 30 sec irradiation directed at the middle ear through the external meatus for a period of 5 days. Positive results were obtained in 45 of the patients with cessation of discharge on the 2nd or 3rd day, and return of hearing by the end of the week. The remission was not permanent in one patient with recurrent otitis media. These observations indicate that the anti-inflammatory effects of helium-neon irradiation constitute an effective treatment modality in children with otitis media. 6 references.

  1. Argon analytical procedures for potassium-argon dating

    International Nuclear Information System (INIS)

    Gabites, J.E.; Adams, C.J.

    1981-01-01

    A manual for the argon analytical methods involved in potassium-argon geochronology, including: i) operating procedures for the ultra-high vacuum argon extraction/purification equipment for the analysis of nanolitre quantities of radiogenic argon in rocks, minerals and gases; ii) operating procedures for the AEI-MS10 gas source mass spectrometer

  2. Laser treatment of medical skin disease in women.

    Science.gov (United States)

    LaRosa, C; Chiaravalloti, A; Jinna, S; Berger, W; Finch, J

    2017-09-01

    Laser treatment is a relatively new and increasingly popular modality for the treatment of many dermatologic conditions. A number of conditions that predominantly occur in women and that have a paucity of effective treatments include rosacea, connective tissue disease, melasma, nevus of Ota, lichen sclerosus (LS), notalgia paresthetica and macular amyloidosis, and syringomas. Laser therapy is an important option for the treatment of patients with these conditions. This article will review the body of literature that exists for the laser treatment of women with these medical conditions.

  3. Laser treatment of medical skin disease in women

    Directory of Open Access Journals (Sweden)

    C. LaRosa, MD

    2017-09-01

    Full Text Available Laser treatment is a relatively new and increasingly popular modality for the treatment of many dermatologic conditions. A number of conditions that predominantly occur in women and that have a paucity of effective treatments include rosacea, connective tissue disease, melasma, nevus of Ota, lichen sclerosus (LS, notalgia paresthetica and macular amyloidosis, and syringomas. Laser therapy is an important option for the treatment of patients with these conditions. This article will review the body of literature that exists for the laser treatment of women with these medical conditions.

  4. Effects of high-pressure argon and nitrogen treatments on respiration, browning and antioxidant potential of minimally processed pineapples during shelf life.

    Science.gov (United States)

    Wu, Zhi-shuang; Zhang, Min; Wang, Shao-jin

    2012-08-30

    High-pressure (HP) inert gas processing causes inert gas and water molecules to form clathrate hydrates that restrict intracellular water activity and enzymatic reactions. This technique can be used to preserve fruits and vegetables. In this study, minimally processed (MP) pineapples were treated with HP (∼10 MPa) argon (Ar) and nitrogen (N) for 20 min. The effects of these treatments on respiration, browning and antioxidant potential of MP pineapples were investigated after cutting and during 20 days of storage at 4 °C. Lower respiration rate and ethylene production were found in HP Ar- and HP N-treated samples compared with control samples. HP Ar and HP N treatments effectively reduced browning and loss of total phenols and ascorbic acid and maintained antioxidant capacity of MP pineapples. They did not cause a significant decline in tissue firmness or increase in juice leakage. HP Ar treatments had greater effects than HP N treatments on reduction of respiration rate and ethylene production and maintenance of phenolic compounds and DPPH(•) and ABTS(•+) radical-scavenging activities. Both HP Ar and HP N processing had beneficial effects on MP pineapples throughout 20 days of storage at 4 °C. Copyright © 2012 Society of Chemical Industry.

  5. Density of atoms in Ar*(3p5 4s) states and gas temperatures in an argon surfatron plasma measured by tunable laser spectroscopy

    NARCIS (Netherlands)

    Hübner, S.; Sadeghi, N.; Carbone, E.A.D.; Mullen, van der J.J.A.M.

    2013-01-01

    This study presents the absolute argon 1 s (in Paschens’s notation) densities and the gas temperature, Tg, obtained in a surfatron plasma in the pressure range 0:65

  6. Potassium-argon technology

    International Nuclear Information System (INIS)

    Cassignol, Charles; Cornette, Yves; David, Benjamin; Gillot, P.-Y.

    1978-04-01

    The main features of the method of processing rocks and minerals and measuring the extracted argon, for the purpose of potassium-argon dating are described. It differs in several respects from the conventional one, as described, f.i., in Dalrymple and Lanphere's monography. Principally it was established that the continual purification of the gases in the mass spectrometer cell during the measurement, stops the peaks of current drift, and renders them representative of the introduced argon. This allows on the one hand to improve the reliability and accuracy of measurements, on the other hand to get rid of the isotopic dilution method, with 38 A as a spike. Moreover the reliability of the radiogenic argon is improved by taking into account the mislinearness of the M.S. response. All this results in a higher performance of the K/Ar dating method, especially in the recent ages range. The technological side of the problem was only dealt with [fr

  7. Laser treatment of medical skin disease in women

    OpenAIRE

    C. LaRosa, MD; A. Chiaravalloti, MD; S. Jinna, MD; W. Berger, BS; J. Finch, MD

    2017-01-01

    Laser treatment is a relatively new and increasingly popular modality for the treatment of many dermatologic conditions. A number of conditions that predominantly occur in women and that have a paucity of effective treatments include rosacea, connective tissue disease, melasma, nevus of Ota, lichen sclerosus (LS), notalgia paresthetica and macular amyloidosis, and syringomas. Laser therapy is an important option for the treatment of patients with these conditions. This article will review the...

  8. Trapping cold ground state argon atoms.

    Science.gov (United States)

    Edmunds, P D; Barker, P F

    2014-10-31

    We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39)  C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10)  cm(3) s(-1).

  9. Treatment of oral soft tissues benign tumors using laser

    Science.gov (United States)

    Crisan, Bogdan; Baciut, Mihaela; Crisan, Liana; Bran, Simion; Rotar, Horatiu; Dinu, Cristian; Moldovan, Iuliu; Baciut, Grigore

    2014-01-01

    The present study aimed to assess the efficacy and indications of surgical laser therapy in the treatment of oral soft tissues benign tumors compared to classic surgery. A controlled clinical study was conducted in a group of 93 patients presenting various forms of oral soft tissues benign tumors. These patients were examined pre-and postoperatively and the oral benign tumors were measured linearly and photographed. The surgery of laser-assisted biopsy excision of oral benign tumors was carried out using a diode laser device of 980 nm. In patients who received surgical laser treatment, therapeutic doses of laser to biostimulate the operated area were administered on the first day after the surgery. The interventions of conventional excision of oral soft tissues benign tumors consisted in removing them using scalpel. In patients who have received therapeutic doses of laser for biostimulation of the operated area, a faster healing of wound surfaces and tumor bed was observed during the first days after surgery. Two weeks after the surgical treatment, good healing without scarring or discomfort in the area of excision was documented. Surgical treatment of oral soft tissues benign tumors with laser assisted postoperative therapy confirms the benefits of this surgical procedure. A faster healing process of the excision area due to laser biostimulation of low intensity has been observed in patients with surgical laser assisted treatment in the postoperative period.

  10. Is argon plasma coagulation an effective and safe treatment option for patients with chronic radiation proctitis after high doses of radiotherapy?

    Directory of Open Access Journals (Sweden)

    Eduardo Hortelano

    Full Text Available Introduction: In severe cases refractory to medical treatment, APC appears to be the preferred alternative to control persistent rectal bleeding of patients with chronic radiation proctitis. Although successful outcomes have been demonstrated in patients previously treated with moderate doses of radiotherapy, there is reluctance towards its indication due to the concern of severe adverse events in patients treated with high doses of radiation. Objectives: The aim of this study was to assess the efficacy and toxicity of APC in the management of bleeding radiation-induced proctitis in patients treated with high doses of radiation for prostate cancer. Methods and materials: Data from 30 patients were treated with APC due to chronic radiation proctitis, were reviewed retrospectively. All cases had prostate cancer and 9 of them (30 % underwent previous radical prostatectomy. The median dose of conformal 3D External Beam Radiotherapy (EBRT delivered was 74 Gy (range 46-76. Median rectal D1cc and D2cc was 72.5 and 72.4 Gy respectively. Median rectal V70, V60 and V40 was 12, 39.5 and 80 %. Cardiovascular and digestive disease, diabetes, smoking behaviour, lowest haemoglobin and transfusion requirements were recorded. Indications for treatment with APC were anemia and persistent bleeding despite medical treatment. Argon gas flow was set at 1.8 l/min with an electrical power setting of 50 W. Results: Median age of all patients was 69.6 years. The median lowest haemoglobin level was 9.6 g/dL. Median time between completion of radiotherapy and first session of APC was 13 months. Ninety-four therapeutic sessions were performed (median 3 sessions. Median time follow-up was 14.5 months (range 2-61. Complete response with resolved rectal bleeding was achieved in 23 patients (77 %, partial response in 5 (16 % and no control in 2 (6 %. No patients required transfusion following therapy. Two patients developed long-term (> 6 weeks grade 2 rectal ulceration and

  11. Utilização do laser de argônio na remoção de sutura corneana Use of argon laser in corneal suture removal

    Directory of Open Access Journals (Sweden)

    Edélcio Vieira

    2004-12-01

    Full Text Available OBJETIVO: Descrever a técnica da retirada de sutura em córnea clara, evitando-se o contato da parte externa do fio com o meio intra-ocular e avaliar se esse procedimento evitaria infecções. MÉTODOS: Foi realizado estudo retrospectivo de 1.233 casos de retirada de sutura de mononylon 10.0 em córnea clara, utilizando-se laser de argônio para cortar o fio, no qual se avaliou a incidência de infecções. RESULTADOS: Em 1.071 olhos, um tiro foi suficiente para cortar o ponto. Em 162 olhos, o tiro do laser atingiu a parte epitelial da sutura, sendo necessários disparos extras para cortar a parte intra-estromal e, assim, retirá-la sem que a parte externa do fio passasse pelo interior da córnea. Não ocorreram complicações após a retirada da sutura. CONCLUSÕES: A técnica utilizada mostrou-se eficaz na remoção das suturas e possivelmente apresenta risco menor de infecção, uma vez que a parte do fio sobrejacente ao epitélio não entra em contato com as camadas mais internas da córnea, nem com a câmara anterior, não tendo sido observado nenhum caso de infecção nesta pesquisa.PURPOSE: To describe the technique of clear-cornea suture removal, that avoids the contact of the external part of the thread with the intraocular medium, and to evaluate whether this procedure would prevent infections. METHODS: A retrospective study of 1.233 cases of clear-cornea mononylon 10.0 suture removal, by the use of an argon laser to cut the thread, was performed. Incidence of infection was then assessed. RESULTS: In 1.071 eyes, one shot was enough to cut the stitch. In 162 eyes, the laser shot hit the epithelial part of the suture, making new shots necessary to cut the intrastromal part, and thus to remove it assuring that the outer part of the stitch would not come in to contact with the interior of the cornea. There were no complications after suture removal. CONCLUSIONS: The technique has shown to be effective in suture removal. And, possibly

  12. Surface Treatment of PEOT/PBT (55/45 with a Dielectric Barrier Discharge in Air, Helium, Argon and Nitrogen at Medium Pressure

    Directory of Open Access Journals (Sweden)

    Pieter Cools

    2018-03-01

    Full Text Available This work describes the surface modification of 300PEO-PEOT/PBT 55/45 thin films using a medium pressure dielectric barrier discharge system operated in argon, helium, nitrogen or dry air to improve cell-surface interactions of this established biomaterial. The first part of the paper describes the optimization of the plasma processing parameters using water contact angle goniometry. The optimized samples are then characterized for changes in surface topography and surface chemical composition using atomic force microscopy (AFM and X-ray fluorescence spectroscopy (XPS respectively. For all plasma treatments, a pronounced increase in surface wettability was observed, of which the extent is dependent on the used plasma discharge gas. Except for dry air, only minor changes in surface topography were noted, while XPS confirmed that the changes in wettability were mainly chemical in nature with the incorporation of 5–10% of extra oxygen as a variety of polar groups. Similarly, for the nitrogen plasma, 3.8% of nitrogen polar groups were additionally incorporated. Human foreskin fibroblast (HFF in vitro analysis showed that within the first 24 h after cell seeding, the effects on cell-surface interactivity were highly dependent on the used discharge gas, nitrogen plasma treatment being the most efficient. Differences between untreated and plasma-treated samples were less pronounced compared to other biodegradable materials, but a positive influence on cell adhesion and proliferation was still observed.

  13. Surface hardening using cw CO2 laser: laser heat treatment, modelation, and experimental work

    Science.gov (United States)

    Muniz, German; Alum, Jorge

    1996-02-01

    In the present work are given the results of the application of laser metal surface hardening techniques using a cw carbon dioxide laser as an energy source on steel 65 G. The laser heat treatment results are presented theoretically and experimentally. Continuous wave carbon dioxide laser of 0.6, 0.3, and 0.4 kW were used. A physical model for the descriptions of the thermophysical laser metal interactions process is given and a numerical algorithm is used to solve this problem by means of the LHT code. The results are compared with the corresponding experimental ones and a very good agreement is observed. The LHT code is able to do predictions of transformation hardening by laser heating. These results will be completed with other ones concerning laser alloying and cladding presented in a second paper.

  14. Laser: A powerful tool for treatment of pyogenic granuloma

    Directory of Open Access Journals (Sweden)

    Shalu Rai

    2011-01-01

    Full Text Available Lasers have opened a new door for the treatment of various disorders. Treatment of soft tissue intraoral mucosal growth by laser has profound effect on the patient acceptability taking the functional and aesthetic factor into consideration. The patient is able to get the outdoor treatment without the phobia of local anaesthetic and is out of the clinic in few minutes in contrast to the traditional method of surgical excision. Very few cases have been reported in literature regarding treatment of mucosal growth by soft tissue lasers. We present a case of recurrent pyogenic granuloma in a patient treated with an alternative approach, that is, diode laser, without the use of anaesthesia, sutures, anti-inflammatory drugs, or analgesics. The diagnosis of this lesion is equally important for correct treatment planning.

  15. Bioactive Ti metal analogous to human cancellous bone: Fabrication by selective laser melting and chemical treatments.

    Science.gov (United States)

    Pattanayak, Deepak K; Fukuda, A; Matsushita, T; Takemoto, M; Fujibayashi, S; Sasaki, K; Nishida, N; Nakamura, T; Kokubo, T

    2011-03-01

    Selective laser melting (SLM) is a useful technique for preparing three-dimensional porous bodies with complicated internal structures directly from titanium (Ti) powders without any intermediate processing steps, with the products being expected to be useful as a bone substitute. In this study the necessary SLM processing conditions to obtain a dense product, such as the laser power, scanning speed, and hatching pattern, were investigated using a Ti powder of less than 45 μm particle size. The results show that a fully dense plate thinner than 1.8 mm was obtained when the laser power to scanning speed ratio was greater than 0.5 and the hatch spacing was less than the laser diameter, with a 30 μm thick powder layer. Porous Ti metals with structures analogous to human cancellous bone were fabricated and the compressive strength measured. The compressive strength was in the range 35-120 MPa when the porosity was in the range 75-55%. Porous Ti metals fabricated by SLM were heat-treated at 1300 °C for 1h in an argon gas atmosphere to smooth the surface. Such prepared specimens were subjected to NaOH, HCl, and heat treatment to provide bioactivity. Field emission scanning electron micrographs showed that fine networks of titanium oxide were formed over the whole surface of the porous body. These treated porous bodies formed bone-like apatite on their surfaces in a simulated body fluid within 3 days. In vivo studies showed that new bone penetrated into the pores and directly bonded to the walls within 12 weeks after implantation into the femur of Japanese white rabbits. The percentage bone affinity indices of the chemical- and heat-treated porous bodies were significantly higher than that of untreated implants. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  16. High power visible diode laser for the treatment of eye diseases by laser coagulation

    Science.gov (United States)

    Heinrich, Arne; Hagen, Clemens; Harlander, Maximilian; Nussbaumer, Bernhard

    2015-03-01

    We present a high power visible diode laser enabling a low-cost treatment of eye diseases by laser coagulation, including the two leading causes of blindness worldwide (diabetic retinopathy, age-related macular degeneration) as well as retinopathy of prematurely born children, intraocular tumors and retinal detachment. Laser coagulation requires the exposure of the eye to visible laser light and relies on the high absorption of the retina. The need for treatment is constantly increasing, due to the demographic trend, the increasing average life expectancy and medical care demand in developing countries. The World Health Organization reacts to this demand with global programs like the VISION 2020 "The right to sight" and the following Universal Eye Health within their Global Action Plan (2014-2019). One major point is to motivate companies and research institutes to make eye treatment cheaper and easily accessible. Therefore it becomes capital providing the ophthalmology market with cost competitive, simple and reliable technologies. Our laser is based on the direct second harmonic generation of the light emitted from a tapered laser diode and has already shown reliable optical performance. All components are produced in wafer scale processes and the resulting strong economy of scale results in a price competitive laser. In a broader perspective the technology behind our laser has a huge potential in non-medical applications like welding, cutting, marking and finally laser-illuminated projection.

  17. [INVITED] Laser treatment of Inconel 718 alloy and surface characteristics

    Science.gov (United States)

    Yilbas, B. S.; Ali, H.; Al-Aqeeli, N.; Karatas, C.

    2016-04-01

    Laser surface texturing of Inconel 718 alloy is carried out under the high pressure nitrogen assisting gas. The combination of evaporation and melting at the irradiated surface is achieved by controlling the laser scanning speed and the laser output power. Morphological and metallurgical changes in the treated surface are analyzed using the analytical tools including optical, electron scanning, and atomic force microscopes, energy dispersive spectroscopy, and X-ray diffraction. Microhardnes and friction coefficient of the laser treated surface are measured. Residual stress formed in the surface region is determined from the X-ray diffraction data. Surface hydrophobicity of the laser treated layer is assessed incorporating the sessile drop method. It is found that laser treated surface is free from large size asperities including cracks and the voids. Surface microhardness increases significantly after the laser treatment process, which is attributed to the dense layer formation at the surface under the high cooling rates, dissolution of Laves phase in the surface region, and formation of nitride species at the surface. Residual stress formed is compressive in the laser treated surface and friction coefficient reduces at the surface after the laser treatment process. The combination of evaporation and melting at the irradiated surface results in surface texture composes of micro/nano-poles and pillars, which enhance the surface hydrophobicity.

  18. SLD liquid argon calorimeter

    International Nuclear Information System (INIS)

    Vella, E.

    1992-10-01

    The liquid argon calorimeter (LAC) of the SLD detector is a parallel plate -- liquid argon sampling calorimeter, used to measure particle energies in Z 0 decays at the Stanford Linear Collider. The LAC module design is based on a unique projective tower structure, in which lead plates and segmented lead tiles serve both as absorbers and electrodes. The LAC front end electronics incorporates several novel features, including extensive multiplexing and optical fiber readout, which take advantage of the low SLC beam crossing frequency. The operational performance of the LAC during the recently completed SLD physics run (which recorded over 10,000 Z 0 events) is discussed

  19. Neuroprotective Treatment of Laser-Induced Retinal Injuries

    National Research Council Canada - National Science Library

    Rosner, Mordechai

    2001-01-01

    .... It is not possible to prevent all these injuries and there is no treatment. This study was designed to evaluate the neuroprotective effect of dextromethorphan, memantine and brimonidine in our rat model of laser- induced retinal-lesions Methods...

  20. Using laser irradiation for the surgical treatment of periodontal disease

    Science.gov (United States)

    Vieru, Rozana D.; Lefter, Agafita; Herman, Sonia

    2002-10-01

    In the marginal pr ogressive profound periodontities, we associated low level laser therapy (LLLT) to the classical surgical treatment with implant of biovitroceramics. From a total of 50 patients, 37 where irradiated with the laser. We used a diode laser, =830 nm, energy density up to 2 J cm2, in Nogier pulsed mode. The laser treatment is used in a complex of therapeutic procedures: odontal, local anti-inflammatory -- as well as in the cabinet and at home --, prosthetic, and for the morphologic and functional rebalancing. The immediate effects where: an evolution without bleeding and without post-surgical complications, as can appear at the patients who didn't benefit of laser irradiation (hematom, pain, functional alteration in the first post-surgical week). Operated tissue is recovering faster. The percentage of recurrences decreases and the success depends less on the biological potential and the immunity of each individual.

  1. Avaliação da camada de fibras nervosas na retinopatia diabética tratada por panfotocoagulação com laser de argônio Examination of the retinal nerve fiber layer in diabetic retinopathy treated by argon laser panphotocoagulation

    Directory of Open Access Journals (Sweden)

    Otacílio de Oliveira Maia Júnior

    2008-04-01

    Full Text Available OBJETIVO: Avaliar alterações na camada de fibras nervosas da retina na retinopatia diabética tratada por panfotocoagulação com laser de argônio. MÉTODOS: Estudo prospectivo de portadores de retinopatia diabética submetidos a panfotocoagulação retiniana. Inicialmente, foram realizados exame oftalmológico completo e tomografia de coerência óptica. Todos pacientes foram submetidos a panfotocoagulação em um dos olhos. A camada de fibras nervosas foi avaliada por meio da tomografia de coerência óptica na 1ª semana, no primeiro, terceiro e sexto meses do tratamento. RESULTADOS: A amostra foi composta por 27 pacientes (27 olhos portadores de diabetes mellitus tipo 2. A idade variou entre 41 e 64 anos (média de 53,7 ± 6,2 anos, sendo 10 (37% pacientes do sexo masculino e 17 (63% do feminino. Quanto ao tipo de retinopatia, 22,2% apresentavam RD proliferativa e 77,8%, RD não proliferativa muito grave. Houve aumento significante nas medidas da espessura da camada de fibras nervosas, permanecendo nos setores temporal, 3 e 4 horas após seis meses de seguimento. Não foi observada qualquer redução na espessura em todos parâmetros analisados. CONCLUSÃO: Não foi evidenciada, a curto e médio prazo, redução na espessura da camada de fibras nervosas em portadores de retinopatia diabética tratada por panfotocoagulação que possa ser identificável por meio da tomografia de coerência óptica. Por outro lado, alguns setores mostraram aumento na espessura durante o seguimento.PURPOSE: To evaluate the alterations in the retinal nerve fiber layer in diabetic retinopathy treated by argon laser panphotocoagulation. METHODS: Prospective study of patients with diabetic retinopathy submitted to retinal panphotocoagulation. Initially, complete ophthalmologic examination and optical coherence tomography were performed. All patients were submitted to panphotocoagulation with argon laser in one of the eyes. The retinal fiber layer was evaluated

  2. Argon in action

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    Over the past few days, the SPS has been accelerating argon ions, which have started to be sent to the NA61/SHINE experiment. This operating mode, using a new type of ion, required a number of modifications to the accelerator.   Picture 1: a “super-cycle” of the SPS, featuring a proton cycle for the LHC, followed by an argon ion cycle for the North Area. Today, the accelerators are once again juggling particles and even performing completely new tricks. The SPS is supplying beams of argon ions for the first time, at energies never before achieved for this type of beam. They are destined for the NA61/SHINE experiment (see box) located in the North Area, which began receiving the beams on 11 February. Argon ions have a relatively large mass, as they consist of 40 nucleons, so they can be used in a similar way to lead ions. The main difficulty in accelerating them lies in the SPS, where the variation in acceleration frequency is limited. “The SPS was designed for a...

  3. Ocular Injury in Cosmetic Laser Treatments of the Face.

    Science.gov (United States)

    Huang, Amy; Phillips, Arianna; Adar, Tony; Hui, Andrea

    2018-02-01

    BACKGROUND: The eye is a vulnerable and commonly injured organ in cosmetic laser procedures of the face. Treatment of the eyelids and periorbital areas increases this risk, especially when ocular protection devices are not used or are removed during the procedure. A study has shown that injury from laser epilation of the periocular areas is one of the most common causes of litigation in cutaneous laser surgery. OBJECTIVE: The goal of this review is to determine the causes of ocular injury in cosmetic laser procedures and derive lessons on critical safety elements to prevent future injury. METHODS: We conducted a review of the current literature through a PubMed search on case reports of ocular injury in cosmetic laser treatments of the face. Twenty-one cases are examined. RESULTS: In more than 62 percent of cases, ocular protection was not used or protection was used but removed during the procedure to treat areas close to the eye. However, despite the proper use of intraocular corneal shields and wavelength-specific goggles, accidents occurred in 33 percent of cases. CONCLUSION: Ocular protection devices are essential to prevent most cases of laser-induced eye injury. Use of high fluence and long wavelength lasers increases the risk of ocular injury due to deeper penetration of the organ by radiation. Inadequate cooling between pulses also predisposes to injury by cosmetic lasers.

  4. Synergistic skin heat shock protein expression in response to combined laser treatment with a diode laser and ablative fractional lasers.

    Science.gov (United States)

    Paasch, Uwe; Sonja, Grunewald; Haedersdal, Merete

    2014-06-01

    Diode laser-based skin heating has been shown to minimise scars by interfering with wound healing responses through the induction of heat shock proteins (HSP). HSP are also induced after ablative fractional laser (AFXL) wound healing. AFXL itself is highly recommended for scar treatment. Therefore, the sequential combination of both modalities may produce superior outcomes. The aim of this study was to examine the pretreatment effects of a diode laser before AFXL on wound healing responses in terms of HSP up-regulation in an in vitro model. Immediate responses and responses on days 1, 3 or 6 post-procedure were studied in an in vitro porcine skin model (n = 240). Untreated samples served as control. Immunohistochemical investigation (Hsp70) was performed in all untreated controls, diode laser-, AFXL-, and in diode laser + AFXL-treated samples. Hsp70 was shown to be up-regulated by all interventions between days 1 and 6 after interventions. The largest effect was caused by the combination of a diode laser and an AFXL procedure. Diode laser exposure induces a skin HSP response that can be further enhanced by sequential AFXL treatment. Clinical studies are necessary to investigate the dose response of HSP on scar formation and refine suitable laser exposure settings.

  5. Diode laser: In treatment of recurrent verrucous leukoplakia

    Directory of Open Access Journals (Sweden)

    Debanti Giri

    2016-01-01

    Full Text Available Laser first came into light in 1960 and had been used extensively in various fields of medicine. Laser has been experimented in the various dental field, and its utility is being recognized and established well in the dentistry. Lasers are widely used for a number of procedures such as cavity preparation, scaling, and root planning, surgical procedures like excision of soft tissue growths, etc., Improved healing, hemostasis, and sutureless excisions are some of the many advantages of laser over conventional treatment modalities. It is because of these advantages that laser is becoming more and more popular as a treatment option in various aspects of dentistry. We hereby present a case report, where we have used diode laser for surgical management of a proliferative verrucous leukoplakia (PVL, because of its many advantages over conventional methods. It presents very specific characteristics, mainly a more aggressive biological behavior than other forms of leukoplakia expressed by: A tendency toward multifocality (field cancerization; a high prospect of recurrence; and a high rate of malignant transformation, which can range between 40% and 100% in a follow-up period of 4.4–11.6 years. In this case, we evaluated the advantages of diode laser for the treatment of verrucous leukoplakia, where the results that we obtained were excellent. The patient had come for evaluation till the time of complete healing.

  6. Pulsed photothermal depth profiling of tattoos undergoing laser removal treatment

    Science.gov (United States)

    Milanic, Matija; Majaron, Boris

    2012-02-01

    Pulsed photothermal radiometry (PPTR) allows noninvasive determination of temperature depth profiles induced by pulsed laser irradiation of strongly scattering biological tissues and organs, including human skin. In present study, we evaluate the potential of this technique for investigational characterization and possibly quantitative evaluation of laser tattoo removal. The study involved 5 healthy volunteers (3 males, 2 females), age 20-30 years, undergoing tattoo removal treatment using a Q-switched Nd:YAG laser. There were four measurement and treatment sessions in total, separated by 2-3 months. Prior to each treatment, PPTR measurements were performed on several tattoo sites and one nearby healthy site in each patient, using a 5 ms Nd:YAG laser at low radiant exposure values and a dedicated radiometric setup. The laser-induced temperature profiles were then reconstructed by applying a custom numerical code. In addition, each tatoo site was documented with a digital camera and measured with a custom colorimetric system (in tristimulus color space), providing an objective evaluation of the therapeutic efficacy to be correlated with our PPTR results. The results show that the laser-induced temperature profile in untreated tattoos is invariably located at a subsurface depth of 300 μm. In tattoo sites that responded well to laser therapy, a significant drop of the temperature peak was observed in the profiles obtained from PPTR record. In several sites that appeared less responsive, as evidenced by colorimetric data, a progressive shift of the temperature profile deeper into the dermis was observed over the course of consecutive laser treatments, indicating that the laser tattoo removal was efficient.

  7. The Effect of Laser Treatment as a Weed Control Method

    DEFF Research Database (Denmark)

    Mathiassen, Solvejg K; Bak, Thomas; Christensen, Svend

    2006-01-01

    at the cotyledon stage. Experiments were carried out under controlled conditions, using pot-grown weeds. Two lasers and two spot sizes were tested and different energy doses were applied by varying the exposure time. The biological efficacy was examined on three different weed species: Stellaria media (common...... was related to wavelength, exposure time, spot size and laser power. The efficacy also varied between the weed species. The results indicate that the efficacy of laser treatments can be improved by a more precise pointing of the laser beam towards the apical meristems and optimisation of the energy density...... (exposure time and spot size of the laser beam). The experiment also showed a significant difference between two wavelengths. In order to improve the performance and to validate the efficacy on a broader spectrum of weed species, further research and development is needed....

  8. [Low power laser biostimulation in the treatment of bronchial asthma].

    Science.gov (United States)

    Milojević, Momir; Kuruc, Vesna

    2003-01-01

    Modern concept of acupuncture is based on the fact there are designated locations on the surface of human body, which are related to integrative systems of an organism by means of sensory nerves, correlating and synchronizing organ functioning, depending on external and internal conditions, by means of nervous and neurohumoral regulation of metabolic and regenerative processes, including also mobilisation of immunological, protective and antistress reactions. Apart from standard needle acupuncture, other methods of stimulating acupuncture points are also applied. Due to invention of low power lasers, irradiation laser acupuncture has been introduced into routine medical practice, characterised by painless and aseptic technique and outstanding clinical results. The investigation was aimed at defining therapeutic effects of low power laser irradiation by stimulating acupuncture points or local treatment of asthma. A prospective analysis included 50 patients treated at the Institute of Pulmonary Diseases in Sremska Kamenica during 2000, 2001 and 2002. Together with conservative treatment of present disease, these patients were treated with laser stimulation of acupuncture points in duration of ten days. During treatment changes of functional respiratory parameters were recorded. Results were compared with those in the control group. The control group consisted of the same number of patients and differed from the examination group only by not using laser stimulation. Patients with bronchial asthma presented with significant improvement (p lower frequency and intensity of attacks. The mechanism of laser stimulation activity in treatment of bronchial asthma is explained in detail, correlating our results to those obtained by other authors. A ten-day course of low-power laser stimulation of acupuncture points in patients with bronchial asthma improves both the lung function and gas exchange parameters. Positive effects of laser treatment in patients with bronchial asthma

  9. Treatment of Gingival Hyperpigmentation by Diode Laser for Esthetical Purposes

    Directory of Open Access Journals (Sweden)

    Hanaa M. El Shenawy

    2015-08-01

    Full Text Available BACKGROUND: Gingival hyperpigmentation is a common esthetical concern in patients with gummy smile or excessive gingival display. Laser ablation has been recognized recently as the most effective, pleasant and reliable technique. It has the advantage of easy handling, short treatment time, hemostasis, decontamination, and sterilization effect. AIM: In the present study we wanted to explore the efficacy of a 980 nm wavelength diode laser in gingival depigmentation clinically by using both VAS and digital imaging method as means of assessment. METHODS: Diode laser ablation was done for 15 patients who requested cosmetic therapy for melanin pigmented gums. The laser beam delivered by fiberoptic with a diameter of 320 µm, the diode laser system has 980 nm wave lengths and 3 W irradiation powers, in a continuous contact mode in all cases, the entire surface of each pigmented maxillary and mandibular gingiva that required treatment was irradiated in a single session. Clinical examination and digital image analysis were done and the patients were followed up for 3 successive months. RESULTS: There was a statistically significant change in prevalence of bleeding after treatment, as none of the cases showed any signs of bleeding 1 week, 1 month and 3 months after ablation. No statistically significant change was observed in the prevalence of swelling after treatment The VAS evaluation demonstrated that only 4 patients complained of mild pain immediately after the procedure. No pain was perceived from the patients in the rest of the follow up period. There was no statistically significant change in prevalence of pain immediately after treatment compared to pain during treatment. There was a decrease in cases with mild pain after 1 week, 1 month as well as 3 months compared to pain during treatment and immediately after treatment. CONCLUSION: Within the limitations of this study, the use of diode laser was shown to be a safe and effective treatment

  10. Efficiency of laser treatment in patients with hereditary hemorrhagic telangiectasia

    DEFF Research Database (Denmark)

    Jørgensen, Gita; Lange, Bibi; Wanscher, Jens Højberg

    2011-01-01

    Earlier studies have shown the effect of laser treatment on epistaxis in patients with hereditary hemorrhagic telangiectasia (HHT). At the present time, only very few prospective trials have been performed, and many studies are based on patients' subjective assessment of the severity of epistaxis....... This prospective study measures the objective effect of laser treatment in HHT patients with mild to moderate epistaxis. We introduce an objective measure to assess the severity of epistaxis: the bleeding time (BT). Before and after treatment, the quality of life, as measured by the patient, was assessed...

  11. Medium-Level Laser in Chronic Tinnitus Treatment

    OpenAIRE

    Dejakum, K.; Piegger, J.; Plewka, C.; Gunkel, A.; Thumfart, W.; Kudaibergenova, S.; Goebel, G.; Kral, F.; Freysinger, W.

    2013-01-01

    The purpose of this study was to evaluate the effect of medium-level laser therapy in chronic tinnitus treatment. In a prospective double-blind placebo-controlled trial, either active laser (450 mW, 830 nm combined Ga-Al-As diode laser) or placebo irradiation was applied through the external acoustic meatus of the affected ear towards the cochlea. Fourty-eight patients with chronic tinnitus were studied. The main outcome was measured using the Goebel tinnitus questionnaire, visual analogue sc...

  12. Isentropic Compression of Argon

    International Nuclear Information System (INIS)

    Oona, H.; Solem, J.C.; Veeser, L.R.; Ekdahl, C.A.; Rodriquez, P.J.; Younger, S.M.; Lewis, W.; Turley, W.D.

    1997-01-01

    We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal

  13. Fractionated laser skin resurfacing treatment complications: a review.

    Science.gov (United States)

    Metelitsa, Andrei I; Alster, Tina S

    2010-03-01

    Fractional photothermolysis represents a new modality of laser skin resurfacing that was developed to provide a successful clinical response while minimizing postoperative recovery and limiting treatment complications. To review all of the reported complications that develop as a result of fractional ablative and nonablative laser skin resurfacing. A literature review was based on a MEDLINE search (1998-2009) for English-language articles related to laser treatment complications and fractional skin resurfacing. Articles presenting the highest level of evidence and the most recent reports were preferentially selected. Complications with fractional laser skin resurfacing represent a full spectrum of severity and can be longlasting. In general, a greater likelihood of developing post-treatment complications is seen in sensitive cutaneous areas and in patients with intrinsically darker skin phototypes or predisposing medical risk factors. Although the overall rate of complications associated with fractional laser skin resurfacing is much lower than with traditional ablative techniques, recent reports suggest that serious complications can develop. An appreciation of all of the complications associated with fractional laser skin resurfacing is important, especially given that many of them can be potentially prevented. The authors have indicated no significant interest with commercial supporters.

  14. Laser Doppler flowmetry evaluation of gingival recovery response after laser treatment

    Science.gov (United States)

    Todea, Carmen; Cânjǎu, Silvana; Dodenciu, Dorin; Miron, Mariana I.; Tudor, Anca; Bǎlǎbuc, Cosmin

    2013-06-01

    This study was performed in order to evaluate in vivo the applicability of Laser Doppler Flowmetry (LDF) in recording the gingival blood flow and to assess the changes of gingival blood flow following gingival reshaping performed with Er:YAG and 980 nm diode lasers. The LDF evaluation was performed on 20 anterior teeth, which underwent reshaping of gingiva, corresponding to 5 female patients (4 anterior teeth/patient), aged between 20 and 35. One part of the mouth was treated with Er:YAG laser (LP, VLP modes, 140 - 250 mJ, 10 - 20 Hz, using cylindrical sapphire tips) and other part with 980 nm diode laser (CW, 4 W, contact mode and saline solution cooling). The gingival blood flow was monitored using a MoorLab laser Doppler equipment (Moor Instruments Ltd., Axminster, UK) with a straight optical probe, MP3b, 10 mm. The data were processed using statistical analysis software SPSS v16.0.1. The investigation showed an evident decrease in perfusion for both areas in comparison with the baseline values 24 hours after treatment. The microvascular blood flow increased significantly after 7 days in both areas but mostly in diode area (pdiode area remained at a high level after 14 days. Both lasers proved efficiency in the surgical treatment of gingival tissue. Moreover, Laser Doppler Flowmetry is adequate for recording changes in gingival blood flow following periodontal surgery.

  15. [Prognostic factors for laser treatment in retinopathy of prematurity].

    Science.gov (United States)

    Talu, Simona; Cormos, Diana; Zaharia, Gabriela; Stefanut, Claudia; Popa, Monica; Lucaci, Daiana Ioana

    2011-01-01

    The paper aims to determine the anatomical results of the eyes treated by laser photocoagulation for "threshold" retinopathy of prematurity (ROP) and to identify the potential risk factors for the unfavorable outcomes. A retrospective study including all the consecutive ROPs that were treated by laser photocoagulation between January the 1st 2006 and September the 1st 2009 has been conducted. The followed criteria has been the anatomical result after the laser treatment. The outcomes have been correlated with: the gestational ages, the birth weights, the moment of treatment (postnatal and post-conceptional ages), the sex of the premature infants, the stage and zone of ROR. RESULTS The total number of prematurely newborns that met the screening criteria for ROP in the above-mentioned period has been 474. Of these, 350 (74%) presented no ROP and the remaining 124 (26%) developed various stages of the disease. Within the ROP group, 54 patients required laser therapy (44% of the retinopathies, representing 11% of all the prematures). The anatomical outcome has been favorable in 84% of the treated eyes, the remaining 16% presenting the progression of ROP The results of the treatment depended on the type of ROP, being significantly better in the classic disease as in the agressive posterior disease (APD) (p < 0.05). The gender also influenced the outcome: the results were better in girls as compared with boys (p < 0.05). The precocity of the laser treatment (evaluated by the postnatal and postconceptional age) has positively influenced the ROP evolution (p < 0.05). Laser photocoagulation has proved its efficacy in the treatment of ROP on our cases. The factors that have negatively influenced the postlaser outcome were: the aggressive posterior disease, the delayed moment of the laser therapy and the male gender.

  16. Carbon dioxide laser versus erbium:YAG laser in treatment of epidermal verrucous nevus: a comparative randomized clinical study.

    Science.gov (United States)

    Osman, Mai Abdel Raouf; Kassab, Ahmed Nazmi

    2017-08-01

    A verrucous epidermal nevus (VEN) is a skin disorder that has been treated using different treatment modalities with varying results. Ablative lasers such as carbon dioxide laser (CO 2 ) and erbium:yttrium-aluminum-garnet (Er:YAG) laser have been considered as the gold standard for the treatment of epidermal nevi. To evaluate and compare the efficacy, postoperative wound healing and side effects of pulsed CO 2 laser and Er:YAG laser for the treatment of verrucous epidermal nevi. Twenty patients with localized VEN were randomly divided into two groups. Group 1 was administered CO 2 laser and group 2 underwent Er:YAG laser treatment. A blinded physician evaluated the photographs and dermoscopic photomicrographs for the efficacy and possible side effects. All patients received one treatment session and were followed up over a 6-month period. Both lasers induced noticeable clinical improvement, but there were no significant differences between two lasers in treatment response, patient satisfaction, duration of erythema and side effects. The average time to re-epithelialization was 13.5 days with CO 2 and 7.9 days with Er:YAG laser (plaser group and no lesional recurrence was detected in CO 2 laser group since treatment. Apart from re-epithelialization, both lasers showed equivalent outcomes with respect to treatment response, patient satisfaction, side effects and complications.

  17. Light/laser therapy in the treatment of acne vulgaris.

    Science.gov (United States)

    Nouri, Keyvan; Villafradez-Diaz, L Magaly

    2005-12-01

    Acne vulgaris is one of the most prevalent skin diseases known. As common as this condition is, the social and psychological consequences are limitless. Although current treatments are available and include topical or oral antibiotics, it is crucial to develop a less risky and more effective therapy such as light/laser therapy. This article focuses specifically on the benefits of the light/laser treatment on acne vulgaris. Porphyrins accumulated in the bacteria, Propionibacterium acnes, one of the etiologic factors involved in the pathogenesis, allows phototherapy to be a successful modality. They have specific absorption peaks at which lasers have optimal effects. The longer the wavelength of the light is, the deeper its penetration and thus the greater its damage to the sebaceous glands. Although blue light is best for the activation of porphyrins, red light is best for deeper penetration and an anti-inflammatory effect. Ultraviolet (UV) light, although it may have initial an anti-inflammatory effects, has been proven to be potentially carcinogenic and have adverse effects such as aging (by UV-A) and burning (by UV-B). Previous studies indicate successful long-term intervention and selective damage of the sebaceous glands by using a diode laser with indocyanine green (ICG) dye. Mid-infrared lasers have been found to decrease lesion counts while also reducing the oiliness of skin and the scarring process. Nonablative laser treatment of acne scars using the Er:YAG laser with a short-pulsed mode has been successful in reducing the appearance of scars by stimulating neocollagenesis. The light/laser therapy has started to be explored with promising results in highly selected patients that require further investigation in greater populations and well-designed protocols.

  18. Laser removal of water repellent treatments on limestone

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Heras, Miguel; Alvarez de Buergo, Monica; Rebollar, Esther; Oujja, Mohamed; Castillejo, Marta; Fort, Rafael

    2003-12-15

    Protective and water repellent treatments are applied on stone materials used on buildings or sculptures of artistic value to reduce water intrusion without limiting the natural permeability to water vapour of the material. The effect of the wavelength associated with the laser removal of two water repellent treatments applied on limestone, Paraloid B-72, a copolymer of methyl acrylate and ethyl methacrylate, and Tegosivin HL-100, a modified polysiloxane resin, was investigated by using the four harmonics of a Q-switched Nd:YAG laser (1064, 532, 355 and 266 nm). The modifications induced on the surface of limestone samples by laser irradiation were studied using colorimetry, roughness measurements and scanning electron microscopy (SEM). The removal of the treatments was found to be dependent on the laser irradiation conditions and on the characteristics of the coatings. The fundamental laser radiation was effective in removing both treatments, but thermal alteration processes were induced on the constituent calcite crystals. The best results were obtained by irradiation in the near UV at 355 nm.

  19. Treatment of oral lichen planus using 308-nm excimer laser.

    Science.gov (United States)

    Liu, Wei-Bing; Sun, Li-Wei; Yang, Hua; Wang, Yan-Fei

    2017-09-01

    Oral lichen planus (OLP) is a chronic inflammatory disease, has prolonged courses, repeated attacks and resistance to treatment. The traditional narrow spectrum UVB treatment has an established efficacy on skin lichen planus, and high safety. However, most of ultraviolet phototherapy devices have a huge volume, thereby cannot be used in the treatment of OLP. Lymphocytic infiltration is evident in the lesions of lichen planus, and the direct irradiation of 308-nm excimer laser can induce apoptosis of the T lymphocytes in skin lesions, thereby has a unique therapeutic effect on the diseases involving T lymphocytes. This study aims to investigate the efficacy of 308-nm excimer laser in the treatment of OLP. A total of six OLP patients were enrolled into this study, and further pathological diagnosis was conducted, then 308-nm excimer laser was used in the treatment. The efficacy of 308-nm excimer laser in the treatment of OLP was satisfactory. The clinical symptoms of five patients were significantly improved. In two patients, the erosion surface based on congestion and the surrounding white spots completely disappeared, and clinical recovery was achieved. Three patients achieved partial remission, that is, the erosion surface healed, congestion and white spot area shrunk by more than 1/2 of the primary skin lesions. In the remaining one patient, the erosion surface had not completely healed after treatment, and congestion and white spot area shrunk by less than 1/2 of the primary skin lesions. Only one patients had developed mild pain during the treatment, and this symptom alleviated by itself. The 308-nm excimer laser therapy can serve as a safe and effective treatment for OLP. © 2017 Wiley Periodicals, Inc.

  20. The physical mechanism on the threshold voltage temperature stability improvement for GaN HEMTs with pre-fluorination argon treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yun-Hsiang [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); A*STAR Institute of Microelectronics, Singapore 117685 (Singapore); Liang, Yung C., E-mail: chii@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); National University of Singapore (Suzhou) Research Institute, Suzhou 215123 (China); Samudra, Ganesh S. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); Huang, Chih-Fang [Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Kuo, Wei-Hung [Industrial Technology Research Institute, Chutung 31040, Taiwan (China); Lo, Guo-Qiang [A*STAR Institute of Microelectronics, Singapore 117685 (Singapore)

    2016-06-06

    In this paper, a normally-off AlGaN/GaN MIS-HEMT with improved threshold voltage (V{sub TH}) thermal stability is reported with investigations on its physical mechanism. The normally-off operation of the device is achieved from novel short argon plasma treatment (APT) prior to the fluorine plasma treatment (FPT) on Al{sub 2}O{sub 3} gate dielectrics. For the MIS-HEMT with FPT only, its V{sub TH} drops from 4.2 V at room temperature to 0.5 V at 200 °C. Alternatively, for the device with APT-then-FPT process, its V{sub TH} can retain at 2.5 V at 200 °C due to the increased amount of deep-level traps that do not emit electrons at 200 °C. This thermally stable V{sub TH} makes this device suitable for high power applications. The depth profile of the F atoms in Al{sub 2}O{sub 3}, measured by the secondary ion mass spectroscopy, reveals a significant increase in the F concentration when APT is conducted prior to FPT. The X-ray photoelectron spectroscopy (XPS) analysis on the plasma-treated Al{sub 2}O{sub 3} surfaces observes higher composition of Al-F bonds if APT was applied before FPT. The enhanced breaking of Al-O bonds due to Ar bombardment assisted in the increased incorporation of F radicals at the surface during the subsequent FPT process. The Schrödinger equation of Al{sub 2}O{sub x}F{sub y} cells, with the same Al-F compositions as obtained from XPS, was solved by Gaussian 09 molecular simulations to extract electron state distribution as a function of energy. The simulation results show creation of the deeper trap states in the Al{sub 2}O{sub 3} bandgap when APT is used before FPT. Finally, the trap distribution extracted from the simulations is verified by the gate-stress experimental characterization to confirm the physical mechanism described.

  1. Desensitization of stainless steels by laser surface heat-treatment

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Yoshikuni; Nishimoto, Kazutoshi

    1987-11-01

    Laser heating was applied for the desensitization heat-treatment of the surface layer in the sensitized HAZ of Type 304 stainless steel. The degree of sensitization was examined by EPR technique and the 10 % oxalic acid electrolytic etch test. The CO/sub 2/ laser with maximum power of 1.5 kW was used for heat-treatment. Time-Temperature-Desensitization diagram (TTDS diagram) for sensitized Type 304 stainless steels were developed by calculation assuming the chromium diffusion control for desensitization which might occur when the chromium depleted zone was healed up due to dissolution of chromium carbide and chromium diffusion from the matrix being heated at the solution annealing temperatures. TTDS diagrams calculated agree fairly well with ones determined by corrosion tests. Laser irradiation conditions (e.g., Laser power, beam diameter and traveling velocity) required for desensitization of sensitized Type 304 stainless steels were calculated using additivity rule from the TTDS diagram calculated and theoretical thermal curve of laser heating derived from the heat conduction theory. After laser beam irradiated under an optimum condition predicted by calculation, the sensitized HAZ of Type 304 stainless steel restored complete resistance to intergranular corrosion.

  2. Lasers in endodontics: an overview

    Science.gov (United States)

    Frentzen, Matthias; Braun, Andreas; Koort, Hans J.

    2002-06-01

    The interest in endodontic use of dental laser systems is increasing. Developing laser technology and a better understanding of laser effects widened the spectrum of possible endodontic indications. Various laser systems including excimer-, argon+-, diode-, Nd:YAG-, Er:YAG- and CO2-lasers are used in pulp diagnosis, treatment of hypersensitivity, pulp capping, sterilization of root canals, root canal shaping and obturation or apicoectomy. With the development of new delivery systems - thin and flexible fibers - for many different wavelengths laser applications in endodontics may increase. Since laser devices are still relatively costly, access to them is limited. Most of the clinical applications are laser assisted procedures such as the removing of pulp remnants and debris or disinfection of infected root canals. The essential question is whether a laser can provide improved treatment over conventional care. To perform laser therapy in endodontics today different laser types with adopted wavelengths and pulse widths are needed, each specific to a particular application. Looking into the future we will need endodontic laser equipment providing optimal laser parameters for different treatment modalities. Nevertheless, the quantity of research reports from the last decade promises a genuine future for lasers in endodontics.

  3. Palliation of oesophagogastric neoplasms with Nd:YAG laser treatment

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, S.; Fischerman, K. (Rigshospitalet, Copenhagen (Denmark))

    1990-01-01

    The palliative effect of endoscopic Nd:YAG laser treatment of malignant strictures of the oesophagus and cardia was prospectively evaluated in 30 patients. Most were primarily treated for dysphagia, and swallowing was improved in 21 and normalized in 14 of these patients. Two patients were successfully treated for bleeding. Six patients developed complications (including two perforations), and four of these were fatal. The median survival was four months. It is concluded that in a great number of patients with inoperable cancer of the oesophagus and cardia, laser treatment is better than other palliative procedures. 23 refs., 2 tabs.

  4. Chromium surface alloying of structural steels during laser treatment

    International Nuclear Information System (INIS)

    Kurov, I.E.; Nagornykh, S.N.; Sivukhin, G.A.; Solenov, S.V.

    1987-01-01

    Results of matrix alloying from the surface layer and creation of considerably increased chromium concentration in the depth which permits to increase the efficiency of laser treatment of steels (12Kh18N10T and 38KhN3M) in the process of their further mechanical polishing, are presented. The treatment was realized by continuous CO 2 -laser at different power densities and scanning rates are presented. A model describing the creation of anomalous distributions of the alloying element in steels is plotted

  5. Laser Surface Treatment and Modification of Aluminum Alloy Matrix Composites

    Science.gov (United States)

    Abbass, Muna Khethier

    2018-02-01

    The present work aimed to study the laser surface treatment and modification of Al-4.0%Cu-1.0%Mg alloy matrix composite reinforced with 10%SiC particles produced by stir casting. The specimens of the base alloy and composite were irradiated with an Nd:YAG laser of 1000 mJ, 1064 nm and 3 Hz . Dry wear test using the pin-on -disc technique at different sliding times (5-30 min) at a constant applied load and sliding speed were performed before and after laser treatment. Micro hardness and wear resistance were increased for all samples after laser hardening treatment. The improvement of these properties is explained by microstructural homogenization and grain refinement of the laser treated surface. Modification and refinement of SiC particles and grain refinement in the microstructure of the aluminum alloy matrix (α-Al) were observed by optical and SEM micrographs. The highest increase in hardness was 21.4% and 26.2% for the base alloy and composite sample respectively.

  6. Fractional photothermolysis laser treatment of male pattern hair loss.

    Science.gov (United States)

    Kim, Won-Serk; Lee, Hye In; Lee, Jin Woong; Lim, Yun Young; Lee, Seung Jae; Kim, Beom Joon; Kim, Myeung Nam; Song, Kye Yong; Park, Won Serk

    2011-01-01

    Various trials have been conducted on the management of male pattern hair loss (MPHL). A variety of laser and light sources have been used for the treatment of MPHL. To understand the effects of a 1,550-nm fractional erbium-glass laser on the hair cycle in an alopecia mouse model and to study the clinical effects of the same laser used as treatment for MPHL. Irradiation was applied to the shaved skin of C3H/HeN mice using various energy and density settings and varied irradiation intervals. In a clinical pilot study involving human subjects, 20 participants were treated over five sessions at 2-week intervals. A fractional photothermolysis laser was used at the energy of 5 mJ and a total density of 300 spots/cm(2). In the animal study, the hair stimulation effects were dependent upon the energy level, density, and irradiation interval. The anagen conversion of hair and the increase in Wnt 5a, β-catenin signals were observed. In the human pilot study, incremental improvements in hair density and growth rate were observed. This pilot study showed that a 1,550-nm fractional erbium-glass laser might induce hair growth, but more intensive studies are required to clarify the clinical applications of this treatment. © 2010 by the American Society for Dermatologic Surgery, Inc.

  7. Diode laser for the treatment of telangiectasias following hemangioma involution.

    Science.gov (United States)

    Cerrati, Eric W; O, Teresa M; Chung, Hoyun; Waner, Milton

    2015-02-01

    Infantile hemangiomas are well known for their rapid growth during the first 6 to 9 months of life, followed by a spontaneous but slow involution. The standard of care is to treat these lesions at an early age with propranolol to expedite the involution process; however, surgery still remains an active component in the management. Medical treatment with propranolol or natural involution will often result in residual telangiectasias. We evaluated the efficacy of using a diode laser as a treatment for telangiectasias following cervicofacial infantile hemangioma involution. Case series with chart review. Tertiary care hospital and practice specializing in the care of vascular anomalies. Twenty patients, aged 4 months to 11 years (average 2.69 years), underwent treatment with a 532-nm diode laser to treat the residual telangiectasias following hemangioma involution. All procedures were performed in the operating room. To assess the efficacy, we independently evaluated pre- and posttreatment digital photographs and ranked them on a 0- to 4-point scale (0 = no change and 4 = complete response). Adverse reactions were also recorded. The telangiectasias showed considerable improvement following treatment. In more than half of the patients treated, the affected area demonstrated a complete response. No adverse reactions were noted. A 532-nm diode laser effectively treats the remaining telangiectasias following hemangioma involution. Whether used independently or in conjunction with other treatment modalities, the diode laser should be part of the surgical armamentarium when treating infantile hemangiomas. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  8. Negative phototropism in Vaucheria terrestris regulated by calcium, 3: The role of calcium characterized by use of a high-power argon-ion laser as the source of unilateral blue light

    International Nuclear Information System (INIS)

    Kataoka, H.; Watanabe, M.

    1993-01-01

    A tip-growing Xanthophycean algal coenocyte, Vaucheria terrestris sensu Gotz, is able to change the sign of its phototropic response from positive to negative as a result of its ability to sense the fluence rate (= intensity) of unilateral blue light (BL). The mechanism that determines the sign of phototropism was investigated using a high-power argon-ion laser (457.9 nm) as a source of very strong unilateral BL. The fluence-response relationship was determined by changing both the fluence rate and the duration of irradiation. Positive phototropic bending was induced when the fluence rate of BL from the laser was below 60 W m-2. The positive bending obeyed the reciprocity law and was not affected by the concentrations of external Ca2+ ions between 0.4 mM and 4.4 mM. The positive curvature decreased when the alga was exposed to aunilateral pulse of BL with a duration of 10-300 s at fluence rates higher than 60 W m-2. The alga finally showed a deep negative curvature when either the fluence rate or the duration of irradiation was further increased. The inversion of the phototropic response and development of the negative phototropic response was greatly enhanced in the presence of 4.4 mM Ca2+ ions. However, the mechanism that determine the sign of phototropism seemed to require a BL pulse of longer than several seconds, even when the fluence rate was sufficiently high. The role of cytoplasmic Ca2+ ions in positive and negative phototropic responses is discussed

  9. Laser Treatment of Professional Tattoos With a 1064/532-nm Dual-Wavelength Picosecond Laser.

    Science.gov (United States)

    Kauvar, Arielle N B; Keaney, Terrence C; Alster, Tina

    2017-12-01

    Picosecond-domain laser pulses improve the photomechanical disruption of tattoos. This study evaluates the efficacy and safety of a novel, dual-wavelength, 1,064/532-nm, picosecond-domain laser for tattoo clearance. This was a prospective, self-controlled, clinical study of 34 subjects with 39 tattoos treated at 2 sites with an interval of 4.8 ± 1.6 weeks and up to 10 treatments (mean, 7.5). Blinded evaluation and investigator assessment of serial digital images was performed to evaluate treatment efficacy in the 36 tattoos that received at least 3 treatments. Investigators also assessed efficacy before each treatment visit up to 10 treatments. Safety and tolerability was evaluated for all 39 tattoos that underwent at least 1 treatment. Blinded evaluation demonstrated that lightening of tattoos was achieved in all subjects, with 86% (31 of 36 tattoos) showing at least a 50% clearance after 3 treatments. Adverse events were few and transient in nature. Patient satisfaction and treatment tolerability were high. Treatment of single-colored and multicolored tattoos with this novel 1,064/532-nm picosecond laser is highly safe and effective.

  10. Wavefront-Guided and Wavefront-Optimised Laser Treatments

    Directory of Open Access Journals (Sweden)

    Canan Aslı Utine

    2012-12-01

    Full Text Available Optical aberrations of the eye are the errors of the optical system that limit the resolution, contrast and amount of detail in the image formed on the retina. Wavefront technology allows us to measure these optical aberrations, calculate mathematically, and transfer this information into excimer laser system to perform customized treatment on the cornea. Two treatment algorithms developed to create low aberration-corneal profile are wavefront-optimised (WF-O and wavefront-guided (WF-G treatments. WF-O treatment, aims not to increase the existing spherical aberration while treatment is based on manifest refractive error as in conventional laser treatments. By increasing the number of laser spots applied peripherally in order to optimize the corneal asphericity, the preoperative central:peripheral keratometry ratio is preserved and optic zone shrinkage is prevented. On the other hand, WF-G treatment is based on aberrometry measurements and aims to correct the existing high-order aberrations in the eye. Thus, retinal image with high spatial details can be achieved. However, presence of postoperative defocus can abolish the successful results obtained with WF-G treatment. Clinical randomized controlled trials showed that in patients with preoperative RMS value of <0.3 μm, higher order aberration outcomes are similar after WF-G and WF-O treatments, but WF-G treatment yields better results when it is ≥0.4 μm. In normal eyes, very limited visual advantage can be achieved with WF-G treatment and preservation of asphericity value with WF-O treatment carries greater importance. On the other hand, in case of high astigmatism or higher order aberrations other than spherical aberration, decreasing aberrations with WF-G treatment becomes more important. In this study, we aimed to make a comparative analysis of characteristics and outcomes of the two treatment algorithms. (Turk J Ophthalmol 2012; 42: 474-8

  11. Liquid-argon calorimetry

    International Nuclear Information System (INIS)

    Fabjan, C.W.

    1989-01-01

    In this paper the viability of liquid-argon calorimetric techniques in the experimental environment of the Superconducting Super Collider (SSC) is briefly analyzed. The authors compare the required and achievable energy resolution with benchmark figures obtained using practical instruments. Comments on the desirable (i.e. required) temporal performance are made and compared with the state of the art. Some of the major engineering challenges are listed, for which solutions will have to be developed if such instruments are to find a place in an SSC experimental area

  12. Can laser treatment improve quality of life of hirsute women?

    Directory of Open Access Journals (Sweden)

    Alizadeh N

    2017-10-01

    Full Text Available Narges Alizadeh,1 Sharad Ayyoubi,2 Mohammadreza Naghipour,3 Rasool Hassanzadeh,2 Zahra Mohtasham-Amiri,3 Shirin Zaresharifi,4 Kaveh Gharaei Nejad1 1Dermatology Department, School of Medicine, Guilan University of Medical Sciences, 2General Practice, School of Medicine, Guilan University of Medical Sciences, 3Community Medicine Department, School of Medicine, Guilan University of Medical Sciences, Rasht, 4General Practitioner, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Background: Hirsutism can have negative impacts on psychosocial aspects of women’s lives and reduce their quality of life (QOL. The aim of this study was to assess the QOL of these women during laser treatment. Patients and methods: Eighty-eight women with unwanted facial hair underwent laser therapy. Each patient completed a questionnaire consisting of a modified Dermatology Life Quality Index (DLQI and visual analog scale (VAS before the first, third, and fifth sessions of laser therapy. Interval between the sessions was 4–6 weeks. Statistical analyses were done using SPSS software version18. Results: The DLQI scores before treatment, and at third and fifth sessions were 7.75±2.36, 5.55±1.88, and 4.14±0.64, respectively (P<0.0001. Also, VAS scores had a decreasing trend between the first and second treatment sessions as the mean patient VAS score fell from 10±0.04 to 5.53±2.41 (P<0.0001. The DLQI scores were significantly different according to areas of hair growth and number of involved areas. There were no significant differences with regard to response to treatment and mean of DLQI score according to the level of education, marital status, and employment status. Conclusion: Hair removal with laser therapy can improve the QOL in hirsute women. Also, socioeconomic status does not affect the satisfaction rate of laser therapy for hair removal. Keywords: hirsutism, laser, quality of life, satisfaction, psychosocial

  13. Laser beam diameter for port wine stain treatment

    NARCIS (Netherlands)

    Keijzer, M.; Pickering, J. W.; van Gemert, M. J.

    1991-01-01

    Optimal port wine stain treatment requires the selective absorption of light by the ectatic blood vessels. We investigated whether deeper blood vessels can be coagulated, without damaging other cutaneous structures, by varying the laser beam diameter. The penetration of the light was simulated with

  14. Assiut Experience in the Application of Holmium Laser in Treatment ...

    African Journals Online (AJOL)

    Assiut Experience in the Application of Holmium Laser in Treatment of Ureteral Calculi in Adults. A.M. Abdel Lateef, A.E. Abdel Moniem, M.I. Taha, M.A. Shalaby. Abstract. Internal Optical Urethrotomy at the National Medical Center of Sanou Souro in Bobo-Dioulasso: Feasibility, Safety and Short-Term Results Objective To ...

  15. Laser heat treatment of welds for various stainless steels

    Science.gov (United States)

    Dontu, O.; Ganatsios, S.; Alexandrescu, N.; Predescu, C.

    2008-03-01

    The paper presents a study concerning the post - weld heat treatment of a duplex stainless steel. Welded joint samples were surface - treated using the same laser source adopted during welding in order to counterbalance the excess of ferrite formed in the welding process.

  16. Application of laser therapy for the treatment of dentinal hyperesthesia

    International Nuclear Information System (INIS)

    Fumero Sanchez, Yanisley; Rodriguez Jorrin, Daimy; Castanneda Marin, Raul

    2009-01-01

    An experimental study was carried out, to evaluate the effectiveness of the low - power laser combined with fluoride varnish to 2% (Profilac) in the treatment of the Dentinal Hyperesthesia in patients attended to in the Stomatology Clinic of Ciro Redondo in the period from October 2007 to January 2008. The universe of study was constituted by 75 patients diagnosed with dentinal hyperesthesia in the period of time indicated above, being conformed the sample by those 25 who fulfilled the pre-established criteria for the study. With the application of the laser combined with Lacquer Fluorine (Profilac), a remission of the pain was observed that increased gradually with the treatment sessions, having been obtained to almost eliminate in the totality of the cases the group of symptoms when finalizing it, evaluating the treatment of effective in 100% of the cases. We only found a recidivism after a year of treatment

  17. Corrosion performance of 7075 alloy under laser heat treatment

    Science.gov (United States)

    Liu, Tong; Su, Ruiming; Qu, Yingdong; Li, Rongde

    2018-05-01

    Microstructure, exfoliation corrosion (EXCO), intergranular corrosion (IGC) and potentidynamic polarization test of the 7075 aluminum alloy after retrogression and re-aging (RRA) treatment, and laser retrogression and re-aging (LRRA), respectively, were studied by using scanning electron microscope, and transmission electron microscope (TEM). The results show that after pre-aging, laser treatment (650 W, 2 mm s‑1) and re-aging a lot of matrix precipitates of alloy were precipitated again. The semi-continuous grain boundary precipitates and the wider precipitate-free zones (PFZ) improve the corrosion resistance of the alloy. The corrosion properties of the alloy after LRRA (650 W, 2 mm s‑1) treatment are better than that after RRA treatment.

  18. Laser Atherectomy for Treatment of Femoropopliteal In-Stent Restenosis.

    Science.gov (United States)

    Armstrong, Ehrin J; Thiruvoipati, Thejasvi; Tanganyika, Kundai; Singh, Gagan D; Laird, John R

    2015-08-01

    To investigate if laser atherectomy with adjunctive balloon angioplasty can improve endovascular treatment outcomes for femoropopliteal in-stent restenosis (ISR). A dual center study included 135 symptomatic patients (mean age 71 years; 76 men) who underwent endovascular treatment of femoropopliteal ISR between 2006 and 2013. Of these, 54 (40%) were treated with laser atherectomy and the remaining 81 patients with balloon angioplasty alone. Angiographic images were reviewed for lesion morphology and characteristics, TransAtlantic InterSociety Consensus (TASC) II classification, and distal runoff. Class I ISR was defined as focal lesions ≤50 mm, class II ISR as lesions >50 mm, and class III ISR as stent total occlusion. Recurrent ISR was determined by a peak systolic velocity ratio >2.4 by duplex ultrasound. Patients treated with laser atherectomy had longer mean ISR lesion length (222 vs 114 mm, patherectomy and rates of recurrent restenosis or occlusion for patients with class I/II ISR, but there was a significantly lower rate of target lesion revascularization at 2 years among patients treated with laser atherectomy (14% vs 44%, p=0.05). In comparison, patients with class III ISR treated with laser atherectomy had lower rates of recurrent restenosis at 1 year (54% vs 91%, p=0.05) and 2 years (69% vs 100%, p=0.05). Patients with class III ISR treated with laser atherectomy also had lower rates of recurrent in-stent occlusion at 2-year follow-up (33% vs 71%, p=0.04). When used to treat complex ISR, including in-stent occlusions, laser atherectomy with adjunctive balloon angioplasty may be associated with improved patency. © The Author(s) 2015.

  19. Treatment of extensive urethral hemangioma with KTP/532 laser.

    Science.gov (United States)

    Lauvetz, R W; Malek, R S; Husmann, D A

    1996-01-01

    Urethral hemangiomas are rare. They vary in size from pinpoint masses to extensive honeycomb-shape deformities leading to significant hematuria. For extensive lesions, therapeutic options have included extensive surgical resection and reconstruction or multistaged neodymium:yttrium-aluminum-garnet (Nd:YAG) laser photocoagulation. We report our experience with the use of potassium titanyl phosphate (KTP/532) laser for treatment of the extensive form. A 7-year-old boy presented with a 2-week history of urethral bleeding. He had extensive hemangiomas of the genital and perineal regions. Cystourethroscopy disclosed diffusely scattered honeycomb-shape hemangiomatous malformation of the anterior urethra. KTP/532 laser energy was delivered transurethrally to the hemangiomatous areas until they blanched. The Foley catheter was removed 24 hours postoperatively, and the patient voided clear urine without difficulty. He has remained trouble-free for more than 2 years. Judicious endoscopic single-stage therapy with KTP/532 laser may obviate open surgical intervention in most cases of extensive and symptomatic urethral hemangiomas. In view of our observation and the literature, KTP/532 laser therapy should be considered the first line of treatment.

  20. Medium-level laser in chronic tinnitus treatment.

    Science.gov (United States)

    Dejakum, K; Piegger, J; Plewka, C; Gunkel, A; Thumfart, W; Kudaibergenova, S; Goebel, G; Kral, F; Freysinger, W

    2013-01-01

    The purpose of this study was to evaluate the effect of medium-level laser therapy in chronic tinnitus treatment. In a prospective double-blind placebo-controlled trial, either active laser (450 mW, 830 nm combined Ga-Al-As diode laser) or placebo irradiation was applied through the external acoustic meatus of the affected ear towards the cochlea. Fourty-eight patients with chronic tinnitus were studied. The main outcome was measured using the Goebel tinnitus questionnaire, visual analogue scales measuring the perceived loudness of tinnitus, the annoyance associated with tinnitus, and the degree of attention paid to tinnitus as well as psycho-acoustical matches of tinnitus pitch and loudness. The results did show only very moderate temporary improvement of tinnitus. Moreover, no statistically relevant differences between laser and placebo group could be found. We conclude that medium-level laser therapy cannot be regarded as an effective treatment of chronic tinnitus in our therapy regime considering the limited number of patients included in our study.

  1. Medium-Level Laser in Chronic Tinnitus Treatment

    Directory of Open Access Journals (Sweden)

    K. Dejakum

    2013-01-01

    Full Text Available The purpose of this study was to evaluate the effect of medium-level laser therapy in chronic tinnitus treatment. In a prospective double-blind placebo-controlled trial, either active laser (450 mW, 830 nm combined Ga-Al-As diode laser or placebo irradiation was applied through the external acoustic meatus of the affected ear towards the cochlea. Fourty-eight patients with chronic tinnitus were studied. The main outcome was measured using the Goebel tinnitus questionnaire, visual analogue scales measuring the perceived loudness of tinnitus, the annoyance associated with tinnitus, and the degree of attention paid to tinnitus as well as psycho-acoustical matches of tinnitus pitch and loudness. The results did show only very moderate temporary improvement of tinnitus. Moreover, no statistically relevant differences between laser and placebo group could be found. We conclude that medium-level laser therapy cannot be regarded as an effective treatment of chronic tinnitus in our therapy regime considering the limited number of patients included in our study.

  2. Argon solubility in liquid steel

    NARCIS (Netherlands)

    Boom, R; Dankert, O; Van Veen, A; Kamperman, AA

    2000-01-01

    Experiments have been performed to establish the solubility of argon in liquid interstitial-free steel. The solubility appears to be lower than 0.1 at ppb, The results are in line with argon solubilities reported in the literature on liquid iron. Semiempirical theories and calculations based on the

  3. Low energy collisions of spin-polarized metastable argon atoms with ground state argon atoms

    Science.gov (United States)

    Taillandier-Loize, T.; Perales, F.; Baudon, J.; Hamamda, M.; Bocvarski, V.; Ducloy, M.; Correia, F.; Fabre, N.; Dutier, G.

    2018-04-01

    The collision between a spin-polarized metastable argon atom in Ar* (3p54s, 3P2, M = +2) state slightly decelerated by the Zeeman slower-laser technique and a co-propagating thermal ground state argon atom Ar (3p6, 1S0), both merged from the same supersonic beam, but coming through adjacent slots of a rotating disk, is investigated at the center of mass energies ranging from 1 to 10 meV. The duration of the laser pulse synchronised with the disk allows the tuning of the relative velocity and thus the collision energy. At these sub-thermal energies, the ‘resonant metastability transfer’ signal is too small to be evidenced. The explored energy range requires using indiscernibility amplitudes for identical isotopes to have a correct interpretation of the experimental results. Nevertheless, excitation transfers are expected to increase significantly at much lower energies as suggested by previous theoretical predictions of potentials 2g(3P2) and 2u(3P2). Limits at ultra-low collisional energies of the order of 1 mK (0.086 μeV) or less, where gigantic elastic cross sections are expected, will also be discussed. The experimental method is versatile and could be applied using different isotopes of Argon like 36Ar combined with 40Ar, as well as other rare gases among which Krypton should be of great interest thanks to the available numerous isotopes present in a natural gas mixture.

  4. Efficacy of long pulse Nd:YAG laser versus fractional Er:YAG laser in the treatment of hand wrinkles.

    Science.gov (United States)

    Robati, Reza M; Asadi, Elmira; Shafiee, Anoosh; Namazi, Nastaran; Talebi, Atefeh

    2018-04-01

    There are different modalities for hand rejuvenation. Fractional Er:YAG laser and long pulse Nd:YAG laser were introduced for treating hand wrinkles. We plan to compare fractional Er:YAG laser and long pulse Nd:YAG laser in a randomized controlled double-blind design with multiple sessions and larger sample size in comparison with previous studies. Thirty-three participants with hand wrinkles entered this study. They were randomly allocated to undergo three monthly laser treatments on each hand, one with a fractional Er:YAG laser and the other with a long pulse Nd:YAG laser. The evaluations included assessment of clinical improvement determined by two independent dermatologists not enrolled in the treatment along with measuring skin biomechanical property of hands using a sensitive biometrologic device with the assessment of cutaneous resonance running time (CRRT). Moreover, potential side effects and patients' satisfaction have been documented at baseline, 1 month after each treatment, and 3 months after the final treatment session. Clinical evaluation revealed both modalities significantly reduce hand wrinkles (p value lasers. Mean CRRT values also decreased significantly after the laser treatment compared to those of the baseline in both laser groups. There was no serious persistent side effect after both laser treatments. Both fractional Er:YAG and long pulse Nd:YAG lasers show substantial clinical improvement of hand skin wrinkles with no serious side effects. However, combination treatment by these lasers along with the other modalities such as fat transfer could lead to better outcomes in hand rejuvenation. IRCT2016032020468N4.

  5. Treatment of the calcaneal spur with infrared laser

    International Nuclear Information System (INIS)

    Orellana, Alina; Larrea, Pedro; Hernandez, Adel; Combarro, Andres; Corcho, Carlos; Fernandez, Sandra; Morales, Omar; Porrua, Agustin; Perez Ares, Jose

    2009-01-01

    The treatment with low power laser offers a beneficial and regenerating effect over nervous, muscular and skeletal tissues, soft tissues, and skin. This therapy has been used for more than three decades, based on the properties and effects of lasers in almost all medical specialties, due to it constitutes a novel, painless, non invasive, and easy to apply, in addition to the absence of any risk for patient and to have very good clinical results. Knowing the biological effects of the low power laser therapy (analgesic, anti-inflammatory, an tissue regenerator), we were dedicated to investigate the analgesic effect achieved with the application of infrared laser radiation in patients that suffering form calcaneal spur, who attended to the Natural and Traditional Medical Service of the clinic '30 de november', from January 2005 to January 2008. The whole of patients was 62, and the sample included 52 individuals from different sexes, races, and ages between 20 and 80 years, excluding pregnant women and neoplasia patients. Pain relief was achieved since second session of treatment, with 61,5 % of cases cured and 38,5 % improved, no one was worse, neither keep the same initial symptoms. (Author)

  6. Choice of the laser wavelength for a herpetic keratitis treatment

    Science.gov (United States)

    Razhev, Alexander M.; Bagayev, Sergei N.; Chernikh, Valery V.; Kargapoltsev, Evgeny S.; Trunov, Alexander; Zhupikov, Andrey A.

    2002-06-01

    For the first time the effect of the UV laser radiation to human eye cornea with herpetic keratitis was experimentally investigated. In experiments the UV radiation of ArF (193 nm), KrCl (223 nm), KrF (248 nm) excimer lasers were used. Optimal laser radiation parameters for the treatment of the herpetic keratitis were determined. The immuno-biochemical investigations were carried out and the results of clinical trials are presented. The maximum ablation rate was obtained for the 248 nm radiation wavelength. The process of healing was successful but in some cases the haze on the surface of the cornea was observed. When used the 193 nm radiation wavelength the corneal surface was clear without any hazes but the epithelization process was slower than for 248 nm wavelength and in some cases the relapse was occurred. The best results for herpetic keratitis treatment have been achieved by utilizing the 223 nm radiation wavelength of the KrCl excimer laser. The use of the 223 nm radiation wavelength allows treating the herpetic keratitis with low traumatic process of ablation and provides high quality of corneal surface.

  7. Pseudoxanthoma Elasticum Treatment with Fractional CO2 Laser

    Directory of Open Access Journals (Sweden)

    Alessandra Grassi Salles, MD, PhD

    2014-09-01

    Full Text Available Summary: Pseudoxanthoma elasticum (PE is a rare genetic disease characterized by calcification and fragmentation of elastic fibers of the skin, retina, and cardiovascular system. We report a case of PE in which fractional carbon dioxide laser treatment was successfully used to achieve improvement of the cervical skin with 2-year follow-up, in a patient with Fitzpatrick skin type IV. After the fifth session, the patient presented with a local herpes infection. The postlaser reaction of the PE skin was similar to that of the normal skin, in terms of the duration of redness, pain, swelling, and duration of crusting. The overall cosmetic result was satisfactory, with improvement in skin texture, irregularity, volume, and distensibility. The herpetic infection reinforces the value of antiviral prophylaxis during laser treatment of extrafacial areas.

  8. Interstitial laser coagulation in the treatment of benign prostatic hyperplasia using a diode laser system: results of an evolving technology

    NARCIS (Netherlands)

    Mårtenson, A. C.; de la Rosette, J. J. M. C. H.

    1999-01-01

    Interstitial laser coagulation (ILC) treatment is a recent technique in the treatment of BPH that is evolving rapidly. The results of a prospective randomised study vs transurethral resection of the prostate (TURP) is presented as well as results of patients treated with a temperature sensing laser

  9. Optical spectroscopy of high-L Rydberg states of argon

    International Nuclear Information System (INIS)

    Wright, L. E.; Snow, E. L.; Lundeen, S. R.; Sturrus, W. G.

    2007-01-01

    High-L fine structure patterns in n=9 and n=17 Rydberg levels of argon have been studied using a Doppler-tuned CO 2 laser and a fast beam of argon atoms. Analysis of the measured pattern using the polarization model yields the scalar dipole polarizability and quadrupole moment of the 2 P 3 at ∼sol∼ at 2 Ar + ion. The results are α S =6.83(8)a 0 3 and Q=-0.5177(15)ea 0 2 . Within the precision of this study, no vector component of the structure was observed

  10. Transscleral contact krypton laser cyclophotocoagulation for treatment of posttraumatic glaucoma.

    Science.gov (United States)

    Raivio, V E; Immonen, I J; Laatikainen, L T; Puska, P M

    2001-04-01

    To evaluate the usefulness of the krypton laser for transscleral contact cyclophotocoagulation in the treatment of posttraumatic glaucoma. A total of 18 eyes of 18 patients with therapy-resistant posttraumatic glaucoma treated with krypton laser cyclophotocoagulation from 1991 to 1996 were included in this review. The krypton laser was delivered by a fiberoptic probe with simultaneous compression of the sclera. The energy used was 3 to 5 J per application at the tip of the probe, with an exposure time of 10 seconds. The treatment covered 90 to 360 degrees of the ciliary body with approximately 10 applications per quadrant. With one or more cyclophotocoagulation treatments, the intraocular pressure decreased from the baseline mean (+/- standard deviation) of 32.6 +/- 12.8 mm Hg to 23.6 +/- 10.3 mm Hg (n = 17) at 1 month, to 21.8 +/- 7.5 mm Hg (n = 13) at 3 months, to 22.5 +/- 7.6 mm Hg (n = 13) at 6 months, and to 19.6 +/- 10.5 mm Hg (n = 18) at the last control visit (mean, 19.4 months; range, 3 weeks to 73 months) after cyclophotocoagulation but no other glaucoma procedure. At baseline, 17 (94%) of 18 patients were taking glaucoma medication, as were 15 (83%) of 18 patients at the last control visit. One (6%) case of phthisis occurred. Krypton laser cyclophotocoagulation is an effective and reasonably well tolerated means of lowering intraocular pressure in posttraumatic glaucoma. Because of the refractory nature of the disease, repeated treatments may be needed.

  11. The Argon Dark Matter Experiment

    CERN Document Server

    AUTHOR|(CDS)2071720

    2009-01-01

    The ArDM experiment, a 1 ton liquid argon TPC/Calorimeter, is designed for the detection of dark matter particles which can scatter off the spinless argon nucleus, producing nuclear recoils. These events will be discerned by their light to charge ratio, as well as the time structure of the scintillation light. The experiment is presently under construction and commissioning on surface at CERN. Cryogenic operation and light detection performance was recently confirmed in a test run of the full 1 ton liquid argon target under purely calorimetric operation and with a prototype light readout system. This note describes the experimental concept, the main detector components and presents some first results.

  12. Treatment of rosacea with long-pulsed Nd: YAG laser

    Directory of Open Access Journals (Sweden)

    Ekin Meşe Say

    2013-03-01

    Full Text Available Background and Design: Rosacea is a chronic inflammatory disorder of the face. There is no curative treatment for the disease. Facial flushing and vascular lesions due to rosacea may significantly affect a patient’s quality of life. Topical and oral antibiotics are not effective for treating rosacea. Currently, laser treatment of vascular lesions has been reported in the literature. We aimed to investigate the efficacy of long-pulse 1064-nm neodymium: YAG (Nd: YAG laser in the treatment of vascular lesions (erythema and telangiectasia in rosacea patients. Materials and Methods: Thirty-nine patients (29 women, 10 men with erythematotelangiectatic rosacea (ETR were recruited into the study. Severity of the disease (ETR-score: 0-3 was assessed for all patients. We used long-pulsed Nd: YAG laser for vascular lesions at 3-4 weeks intervals. The face was divided into seven anatomic regions for evaluation. Assessment was made by comparing pretreatment and posttreatment photographs by using ETR-scores. For evaluating patient satisfaction, a scale of 0 to 3 was used. Results: The patients were divided into three groups according to the ETR scores [ETR-1 (n=12, ETR-2 (n=9, ETR-3 (n=18]. Following an average of 3.95 (2-8 sessions laser treatments, the clinical improvement was statistically significant in all groups (p<0.05. The mean reduction of ETR-score was 91.70% in patients with ETR-1 and. the clinical improvement was to be decreased in severe forms of ETR. The most common sites for the lesions were the malar region, ala nasi and the nasal dorsum, respectively. The lesions on the ala nasi were more recalcitrant to the treatment than those on the other areas. Regarding to physician assessment of treatment’s success, 97% of the patients was associated with moderate and excellent improvement. According to physicians’ assessment, excellent improvement was noticed in 43.58% and, 61.5% of patients reported a high degree of satisfaction with this

  13. Pulsed dye laser treatment of rosacea using a novel 15 mm diameter treatment beam.

    Science.gov (United States)

    Bernstein, Eric F; Schomacker, Kevin; Paranjape, Amit; Jones, Christopher J

    2018-04-10

    The pulsed-dye laser has been used to treat facial redness and rosacea for decades. Recent advances in dye laser technology enable 50% higher output energies supporting 50% larger treatment areas, and beam-diameters up to 15 mm with clinically-relevant fluences. In this study, we investigate this novel pulsed-dye laser using a 15 mm diameter beam for treatment of rosacea. Twenty subjects with erythemato-telangiectatic rosacea were enrolled in the study. A total of 4 monthly treatments were administered, first treating linear vessels with a 3 × 10 mm elliptical beam, then diffuse redness with a 15-mm diameter circular beam. Blinded assessment of digital, cross-polarized photographs taken 2 months following the last treatment was performed using an 11-point clearance scale. Nineteen subjects completed the study. Blinded reviewers correctly identified baseline photos in 55 out of the total of 57 images (96.5%). The blinded reviewers scored 17 of the 19 subjects with an improvement greater than 40%, and 11 of the 19 subjects greater than 50%. The average improvement was 53.9%. Side effects were limited to mild edema, mild to moderate erythema, and mild to moderate bruising. This study demonstrates that a newly designed pulsed-dye laser having a novel 15-mm diameter treatment beam improves the appearance of rosacea with a favorable safety profile. Lasers Surg. Med. 9999:1-5, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

  14. International registry results for an interstitial laser BPH treatment device

    Science.gov (United States)

    Conn, Richard L.; Muschter, Rolf; Adams, Curtis S.; Esch, Victor C.

    1996-05-01

    Benign prostatic hyperplasia (BPH) can significantly impair quality of life in older men. Most men over 60 experience some symptoms due to BPH and it is thought that essentially all men would eventually be affected by it if they lived long enough. At present, transurethral resection of the prostate (TURP), a surgical treatment for BPH, is one of the more common procedures performed in the developed world, particularly in the United States. A number of other treatments are also often used, including open prostatectomy, side-firing lasers, and drug therapy. With the population in the developed world rapidly aging, BPH is expected to affect an even larger group of men in the future. Current methods of therapy carry significant disadvantages. Open prostatectomy carries a fairly high risk of impotence and incontinence, as well as sometimes significant risk of death depending on the patient's age and medical conditions. TURP also carries similar risks, albeit reduced, including the risk of substantial blood loss and a small but meaningful risk of death. Side-firing lasers are thought to have a reduced risk of death compared to TURP due to significantly reduced bleeding; however, patients often experience an extended period of pain during voiding due to prolonged tissue sloughing. Drug treatment, although useful for some patients, does not strongly improve symptoms in the majority of patients. Even with the current range of treatments, many patients with symptomatic BPH elect to avoid any current treatment due to risks and side effects. As a possible solution to this problem, previous writers have suggested the possibility of treating BPH through interstitial thermotherapy. In this treatment, prostatic tissue is heated from within the prostate to the point of irreversible necrosis. Healing processes then reduce the volume of the affected tissue, even in the absence of sloughing. This study covers initial human use of such a device, using an 810 nm wavelength diode laser

  15. Hybrid fuzzy logic control of laser surface heat treatments

    International Nuclear Information System (INIS)

    Perez, Jose Antonio; Ocana, Jose Luis; Molpeceres, Carlos

    2007-01-01

    This paper presents an advanced hybrid fuzzy logic control system for laser surface heat treatments, which allows to increase significantly the uniformity and final quality of the obtained product, reducing the rejection rate and increasing the productivity and efficiency of the treatment. Basically, the proposed hybrid control structure combines a fuzzy logic controller, with a pure integral action, both fully decoupled, improving the performances of the process with a reasonable design cost, since the system nonlinearities are fully compensated by the fuzzy component of the controller, while the integral action contributes to eliminate the steady-state error

  16. Laser trabeculoplasty as the primary therapy in simple and capsular glaucoma

    International Nuclear Information System (INIS)

    Tuulonen, A.

    1984-01-01

    Very little is known about the efficacy of Argon laser trabeculoplasty as an initial therapy in early glaucomatous eyes. Owing to the favourable results gained with laser trabeculoplasty in the treatment of advanced stages of glaucoma and the low rate of complications reported, laser trabeculoplasty was accepted as an alternative to conventional medical therapy in early open angle glaucoma. In this paper, a retrospective study of 54 treated patients, the therapy is reported to be highly effective. (Auth.)

  17. The Liquid Argon Purity Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Adamowski, M.; Carls, B.; Dvorak, E.; Hahn, A.; Jaskierny, W.; Johnson, C.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Stancari, M.; Tope, T.; Voirin, E.; Yang, T.

    2014-07-01

    The Liquid Argon Purity Demonstrator was an R&D test stand designed to determine if electron drift lifetimes adequate for large neutrino detectors could be achieved without first evacuating the cryostat. We describe here the cryogenic system, its operations, and the apparatus used to determine the contaminant levels in the argon and to measure the electron drift lifetime. The liquid purity obtained by this system was facilitated by a gaseous argon purge. Additionally, gaseous impurities from the ullage were prevented from entering the liquid at the gas-liquid interface by condensing the gas and filtering the resulting liquid before returning to the cryostat. The measured electron drift lifetime in this test was greater than 6 ms, sustained over several periods of many weeks. Measurements of the temperature profile in the argon, to assess convective flow and boiling, were also made and are compared to simulation.

  18. Clinical and histological responses of congenital melanocytic nevi after single treatment with Q-switched lasers

    NARCIS (Netherlands)

    Grevelink, JM; vanLeeuwen, RL; Anderson, RR; Byers, HR

    Background: Laser irradiation of congenital melanocytic nevi is a controversial treatment. Recurrence of lesions after laser treatment appears to be the rule, and the effects of laser irradiation on cellular biological behavior and the possible mutagenic responses of nevomelanocytes that have

  19. Transurethral laser therapy of tumours of the bladder

    International Nuclear Information System (INIS)

    Noeske, H.D.; Rothauge, C.F.; Kraushaar, J.

    1979-01-01

    Surgical treatment of tumours of the bladder is still not generally accepted, and its results are unsatisfactory. To ameliorate this situation, the new energy source of laser is now being tested in transurethral treatment. There are several groups of scientists who study the use of lasers suited for human medicine: CO 2 laser (Tel Aviv), YAG neodymium laser (Munich), and argon laser (Giessen). In the urological university hospital at Giessen, where a human bladder carcinoma received laser treatment for the first time in the world in 1976, 45 argon laser operations on 38 patients are investigated. There were 37 bladder tumours of different stages and one haemangioma. Laser monotherapy was applied in 11 cases. The bulk of the cases, however, was treated by combined electro-laser-surgical treatment where the tumour bed and its immediate neighbourhood were irradiated after TUR. The results do not give a satisfactory answer as to the therapeutic value of laser. Advantages over TUR will probably be purely technical. (orig.) [de

  20. A widespread allergic reaction to black tattoo ink caused by laser treatment.

    Science.gov (United States)

    Bernstein, Eric F

    2015-02-01

    This is the first reported case of a local and widespread reaction in a 39 year old woman, to black tattoo ink, induced by Q-switched laser treatment. A 39 year old woman was treated with the Q-switched Nd:YAG laser for removal of a decorative tattoo of her lower back. Subsequent to laser treatment, a severe, widespread allergic reaction developed within and surrounding the treated tattoo. Tattoo reactions subsequent to laser treatment should be considered in addition to reactions to topical antibiotics or wound dressings, following laser treatment of tattoos. © 2015 Wiley Periodicals, Inc.

  1. Behavior of Excited Argon Atoms in Inductively Driven Plasmas

    International Nuclear Information System (INIS)

    HEBNER, GREGORY A.; MILLER, PAUL A.

    1999-01-01

    Laser induced fluorescence has been used to measure the spatial distribution of the two lowest energy argon excited states, 1s 5 and 1s 4 , in inductively driven plasmas containing argon, chlorine and boron trichloride. The behavior of the two energy levels with plasma conditions was significantly different, probably because the 1s 5 level is metastable and the 1s 4 level is radiatively coupled to the ground state but is radiation trapped. The argon data is compared with a global model to identify the relative importance of processes such as electron collisional mixing and radiation trapping. The trends in the data suggest that both processes play a major role in determining the excited state density. At lower rfpower and pressure, excited state spatial distributions in pure argon were peaked in the center of the discharge, with an approximately Gaussian profile. However, for the highest rfpowers and pressures investigated, the spatial distributions tended to flatten in the center of the discharge while the density at the edge of the discharge was unaffected. The spatially resolved excited state density measurements were combined with previous line integrated measurements in the same discharge geometry to derive spatially resolved, absolute densities of the 1s 5 and 1s 4 argon excited states and gas temperature spatial distributions. Fluorescence lifetime was a strong fi.mction of the rf power, pressure, argon fraction and spatial location. Increasing the power or pressure resulted in a factor of two decrease in the fluorescence lifetime while adding Cl 2 or BCl 3 increased the fluorescence lifetime. Excited state quenching rates are derived from the data. When Cl 2 or BCl 3 was added to the plasma, the maximum argon metastable density depended on the gas and ratio. When chlorine was added to the argon plasma, the spatial density profiles were independent of chlorine fraction. While it is energetically possible for argon excited states to dissociate some of the

  2. Estimating the best laser parameters for skin cancer treatment using finite element models

    International Nuclear Information System (INIS)

    El-Berry, A.A.; El-Berry, A.A.; Solouma, N.H.; Hassan, F.; Ahmed, A.S.

    2010-01-01

    Skin cancer is an intimidating disease which necessitates the presence of a non-invasive treatment. Laser-induced thermo therapy is one of the recent noninvasive modalities of superficial lesion treatment. Although of its promising effect, this method still needs more effort to be quantized. Many studies are being conducted for this purpose. Modeling and simulating the process of skin lesion treatment by laser can lead to the best quantization of the treatment protocol. In this paper, we provide finite element models for the treatment of skin cancer using laser thermal effect. A comparison between the effects of using different laser parameters of diode laser (800nm) and Nd: Yag laser (1064 nm) revealed that Nd: Yag laser can be used effectively foe skin cancer treatment specially with high intensities of about 106 w/m 2 .

  3. Electron densities and energies of a guided argon streamer in argon and air environments

    International Nuclear Information System (INIS)

    Hübner, S; Hofmann, S; Van Veldhuizen, E M; Bruggeman, P J

    2013-01-01

    In this study we report the temporally and spatially resolved electron densities and mean energies of a guided argon streamer in ambient argon and air obtained by Thomson laser scattering. The plasma is driven by a positive monopolar 3.5 kV pulse, with a pulse width of 500 ns and a frequency of 5 kHz which is synchronized with the high repetition rate laser system. This configuration enables us to use the spatial and temporal stability of the guided streamer to accumulate a multitude of laser/plasma shots by a triple grating spectrometer equipped with an ICCD camera and to determine the electron parameters. We found a strong initial n e -overshoot with a maximum of 7 × 10 19  m −3 and a mean electron energy of 4.5 eV. This maximum is followed by a fast decay toward the streamer channel. Moreover, a 2D distribution of the electron density is obtained which exhibits a peculiar mushroom-like shape of the streamer head with a diameter significantly larger than that of the emission profile. A correlation of the width of the streamer head with the expected pre-ionization channel is found. (paper)

  4. Visualization of laser tattoo removal treatment effects in a mouse model by two-photon microscopy.

    Science.gov (United States)

    Jang, Won Hyuk; Yoon, Yeoreum; Kim, Wonjoong; Kwon, Soonjae; Lee, Seunghun; Song, Duke; Choi, Jong Woon; Kim, Ki Hean

    2017-08-01

    Laser tattoo removal is an effective method of eliminating tattoo particles in the skin. However, laser treatment cannot always remove the unwanted tattoo completely, and there are risks of either temporary or permanent side effects. Studies using preclinical animal models could provide detailed information on the effects of laser treatment in the skin, and might help to minimize side effects in clinical practices. In this study, two-photon microscopy (TPM) was used to visualize the laser treatment effects on tattoo particles in both phantom specimens and in vivo mouse models. Fluorescent tattoo ink was used for particle visualization by TPM, and nanosecond (ns) and picosecond (ps) lasers at 532 nm were used for treatment. In phantom specimens, TPM characterized the fragmentation of individual tattoo particles by tracking them before and after the laser treatment. These changes were confirmed by field emission scanning electron microscopy (FE-SEM). TPM was used to measure the treatment efficiency of the two lasers at different laser fluences. In the mouse model, TPM visualized clusters of tattoo particles in the skin and detected their fragmentation after the laser treatment. Longitudinal TPM imaging observed the migration of cells containing tattoo particles after the laser treatment. These results show that TPM may be useful for the assessment of laser tattoo removal treatment in preclinical studies.

  5. Rabi oscillations in extreme ultraviolet ionization of atomic argon

    Science.gov (United States)

    Flögel, Martin; Durá, Judith; Schütte, Bernd; Ivanov, Misha; Rouzée, Arnaud; Vrakking, Marc J. J.

    2017-02-01

    We demonstrate Rabi oscillations in nonlinear ionization of argon by an intense femtosecond extreme ultraviolet (XUV) laser field produced by high-harmonic generation. We monitor the formation of A r2 + as a function of the time delay between the XUV pulse and an additional near-infrared (NIR) femtosecond laser pulse, and show that the population of an A r+* intermediate resonance exhibits strong modulations both due to an NIR laser-induced Stark shift and XUV-induced Rabi cycling between the ground state of A r+ and the A r+* excited state. Our experiment represents a direct experimental observation of a Rabi-cycling process in the XUV regime.

  6. Pattern scan laser versus single spot laser in panretinal photocoagulation treatment for proliferative diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Shu Zhang

    2017-02-01

    Full Text Available AIM: To investigate the efficacy of 577-nm pattern scan laser in panretinal photocoagulation(PRPtreatment in newly diagnosed proliferative diabetic retinopathy(PDR.METHODS:Prospective and comparative observation was performed in totally 32 patients with high-risk PDR. They were randomly divided into group 1(using pattern scan laser, PSLand 2(using single spot laser, SSL, each containing 16 subjects to which totally 20 eyes received PRP. Non-perfusion region was identified with fundus fluorescein angiography(FFAbefore and 3mo after final PRP. The advantage of PSL was verified in terms of the number and the duration of PRP sessions needed for satisfactory outcomes, and the pain score.RESULTS: Three PRP sessions were needed for each eye to complete the treatment using PSL, while 4 sessions were needed using SSL. The duration of each session with PSL in group 1 was 7.3±2.3min, which was significantly shorter than that with SSL in group 2(13.2±4.1, t38=5.596, PPCONCLUSION: PSL showed clear advantages over SSL in the PRP treatment of PDR, not only in the improved efficacy, but also in the reduction of pain and the improvement of effectiveness.

  7. Watermelon stomach: clinical aspects and treatment with argon plasma coagulation Ectasia vascular do antro gástrico ("watermelon stomach": aspectos clínicos e tratamento com coagulação com plasma de argônio

    Directory of Open Access Journals (Sweden)

    Dalton M. Chaves

    2006-09-01

    Full Text Available BACKGROUND: Gastric antral vascular ectasia is a disorder whose pathogenetic mechanism is unknown. The endoscopic treatment with argon plasma coagulation has been considered one of the best endoscopic therapeutic options. AIM: To analyze the endoscopic and clinical features of gastric antral vascular ectasia and its response to the argon plasma coagulation treatment. PATIENTS AND METHODS: Eighteen patients were studied and classified into two groups: group 1 - whose endoscopic aspect was striped (watermelon or of the diffuse confluent type; group 2 - diffuse spotty nonconfluent endoscopic aspect. RESULTS: Group 1 with eight patients, all having autoimmune antibodies, but one, whose antibodies were not searched for. Three were cirrhotic and three had hypothyroidism. All had gastric mucosa atrophy. In group 2, with 10 patients, all had non-immune liver disease, with platelet levels below 90.000. Ten patients were submitted to argon plasma coagulation treatment, with 2 to 36 months of follow-up. Lesions recurred in all patients who remained in the follow-up program and one did not respond to treatment for acute bleeding control. CONCLUSION: There seem to be two distinct groups of patients with gastric antral vascular ectasia: one related to immunologic disorders and other to non-immune chronic liver disease and low platelets. The endoscopic treatment using argon plasma coagulation had a high recurrence in the long-term evaluation.RACIONAL: "Watermelon stomach" ou ectasia vascular do antro gástrico é uma doença de etiopatogenia desconhecida. O tratamento endoscópico através da coagulação com plasma de argônio é considerado uma das melhores opções terapêuticas. OBJETIVO: Analisar os aspectos clínicos e endoscópicos da ectasia vascular do antro gástrico e a resposta ao tratamento com coagulação com plasma de argônio. PACIENTES E MÉTODOS: Dezoito pacientes foram estudados e classificados em dois grupos: grupo I - oito pacientes que

  8. Treatment of Dentine Hypersensitivity by Diode Laser: A Clinical Study

    Directory of Open Access Journals (Sweden)

    Romeo Umberto

    2012-01-01

    Full Text Available Introduction. Dentine hypersensitivity (DH is characterized by pain after stimuli that usually provoke no symptoms. This study compared the effectiveness of GaAlAs diode laser alone and with topical sodium fluoride gel (NaF. Materials and Methods. The study was conducted on 10 patients (8 F/2 M, age 25–60 and 115 teeth with DH assessed by air and tactile stimuli measured by Numeric Rating Scale (NRS. Teeth were randomly divided into G1 (34 teeth treated by 1.25% NaF; G2 (33 teeth lased at 0.5 W PW (T on 100 m and T off 100 ms, fluence 62.2 J/cm2 in defocused mode with a 320 μ fiber. Each tooth received three 1′ applications; G3 (48 teeth received NaF gel plus laser at same G2 parameters. NRS was checked at each control. Results. Significant pain reduction was showed. The NRS reduction percentages were calculated, and there was a concrete decrease of DH above all in G3 than G2 and G1. Conclusion. Diode laser is a useful device for DH treatment if used alone and mainly if used with NaF gel.

  9. 308-nm excimer laser for the treatment of alopecia areata.

    Science.gov (United States)

    Al-Mutairi, Nawaf

    2007-12-01

    Alopecia areata is loss of hair from localized or diffuse areas of hair-bearing area of the skin. Recently there are reports of efficacy of the 308-nm excimer radiation for this condition. To study the effect of the 308-nm excimer laser in the treatment of alopecia areata. Eighteen patients with 42 recalcitrant patches (including 1 adult with alopecia totalis) were enrolled in this study. The lesions were treated with the 308-nm excimer laser twice a week for a period of 12 weeks; one lesion on each patient was left as a control for comparison. There were 7 males and 11 females in this study. Regrowth of hair was observed in 17 (41.5%) patches. Thirteen of the 18 lesions in scalp showed a complete regrowth of hair. The extremity regions failed to show a response. Atopic diatheses had an unfavorable effect on the outcome in our patients. The 308-nm excimer laser is an effective therapeutic option for patchy alopecia areata of the scalp and for some cases with patchy alopecia areata of the beard area. It does not work for patchy alopecia areata of the extremities.

  10. Laser laparoscopy in the treatment of polycystic ovarian disease

    Science.gov (United States)

    Mutrynowski, Andrzej; Zabielska, Renata

    1996-03-01

    A polycystic ovaries disease occurs in the case of women with anovulatory cycles as the result of neurohormonal disorders. Patients with this disease suffer from infertility and many symptoms, such as: irregular menstrual bleeding, hirsutism, obesity. The paper presents a method of the carbon dioxide laser laparoscopy in the polycystic ovary disease treatment. The study included 96 women operated on (carbon dioxide laser laparoscopy) in the II Clinic Of Obstetric and Gynecology in Warsaw. Each woman measured her body temperature in order to evaluate her menstrual cycle and had vaginal USG examination or a cytohormonal one before laparoscopy and within 6 months after the surgery. Performing the laparoscopy the operator punctured each ovary in at least 15 points using the carbon dioxide laser. The patients were followed-up for 6 months. The Chi test was used to make the statistic analysis. Comparing the percent of ovulatory cycles and regular ones before and after surgery we noticed that the differences were statistically relevant. Eighty-five patients (88%) had regular cycles and in 88 cases (92%) there was a diphasic curve of the body temperature after the laparoscopy. Fourteen percent of infertile women with polycystic ovary disease conceived.

  11. Unwanted facial hair removal with laser treatment improves quality of life of patients.

    Science.gov (United States)

    Maziar, Ali; Farsi, Nader; Mandegarfard, Manijeh; Babakoohi, Shahab; Gorouhi, Farzam; Dowlati, Yahya; Firooz, Alireza

    2010-02-01

    Unwanted facial hair can have adverse psychological effects on women and reduce their quality of life. To assess the effects of unwanted facial hair removal with laser on improving quality of life. In this study, 70 patients treated for unwanted facial hair by laser were assessed by Dermatology Life Quality Index (DLQI) questionnaire on admission and 3 months later after three sessions of laser treatment. The DLQI score before treatment was 9.42 +/- 5.99, which was reduced to 3.12 +/- 3.40 after laser treatment (p facial hair removal with laser can improve the quality of life of patients.

  12. Influence of argon impurities on the elastic scattering of x-rays from imploding beryllium capsules

    Science.gov (United States)

    Saunders, A. M.; Chapman, D. A.; Kritcher, A. L.; Schoff, M.; Shuldberg, C.; Landen, O. L.; Glenzer, S. H.; Falcone, R. W.; Gericke, D. O.; Döppner, T.

    2018-03-01

    We investigate the effect of argon impurities on the elastic component of x-ray scattering spectra taken from directly driven beryllium capsule implosions at the OMEGA laser. The plasma conditions were obtained in a previous analysis [18] by fitting the inelastic scattering component. We show that the known argon impurity in the beryllium modifies the elastic scattering due to the larger number of bound electrons. We indeed find significant deviations in the elastic scattering from roughly 1 at.% argon contained in the beryllium. With knowledge of the argon impurity fraction, we use the elastic scattering component to determine the charge state of the compressed beryllium, as the fits are rather insensitive to the argon charge state. Finally, we discuss how doping small fractions of mid- or high-Z elements into low-Z materials could allow ionization balance studies in dense plasmas.

  13. Dentine bond strength of a composite resin polymerized with conventional light and argon laser Resistência de união à dentina de resina composta polimerizada com luz halógena e laser de argônio

    Directory of Open Access Journals (Sweden)

    Patricia Ramos Lloret

    2004-09-01

    Full Text Available The use of argon laser (488 nm has been suggested as a new alternative for polymerizing adhesive materials. This study aimed to evaluate the tensile bond strength of a microfilled composite (A110, 3M inserted by incremental technique (3 increments of 1 mm and by single increment (3 mm polymerized by argon laser for 10, 20 and 30 seconds and halogen light for 40 seconds. Eighty (8 groups of 10 teeth freshly extracted bovine teeth were stored in a freezer in distilled water for one week. The crowns were cross-sectioned from the roots. Pulpectomy was performed and the pulp chambers were sealed with wax. The buccal surfaces of the teeth were ground with wet sandpaper (grains: 120, 400, and 600 to expose the surface dentin, and the teeth were then included in acrylic resin. A metal device was used to fix each sample and a black propylene matrix25 (3 mm high with an internal millimetric delimitation was used to insert the material according to the groups studied. The polymerization intervals were of 10, 20 and 30 seconds for the laser polymerization and 40 seconds for the conventional polymerization. Tensile tests were performed by a Universal Testing Machine 4442 (Instron at a speed of 0.5 mm/min and 500 N load. According to the methodology used, the incremental technique increased bond strength values. There was no difference between the studied polymerization techniques when resin was filled in 3 increments.O uso do laser de argônio (488 nm tem sido sugerido como uma nova alternativa para polimerização de materiais adesivos. Este estudo tem o objetivo de avaliar a resistência adesiva de uma resina composta microparticulada (A110, 3M inserida pela técnica incremental (3 incrementos de 1 mm e de incremento único (3 mm polimerizada com laser de argônio por 10, 20 e 30 segundos e com luz halógena por 40 segundos. Oitenta (8 grupos com 10 dentes dentes bovinos recém-extraídos foram armazenados em geladeira, em água destilada, por uma semana

  14. Bronchology Treatment Of The Malignant Airway Stenosis

    International Nuclear Information System (INIS)

    Slivka, R. et al

    2007-01-01

    Central airway stenosis is benign or malignant etiology. Multidiscplinary approach is useful in treatment central airway stenosis. In inoperable cases, interventional bronchology is good therapeutic alternative. We can use NdYAG laser, argon plasma coagulation, elektrocautery, cryotherapy, photodynamic therapy and stents for obstruction release. In malignant stenosis, we combine often methods of the interventional bronchology with brachytherapy, chemotherapy and external radiotherapy. (author)

  15. Laser Phototherapy As Modality of Clinical Treatment in Bell's Palsy

    Science.gov (United States)

    Marques, A. M. C.; Soares, L. G. P.; Marques, R. C.; Pinheiro, A. L. B.; Dent, M.

    2011-08-01

    Bell's palsy is defined as a peripheral facial nerve palsy, idiophatic, and sudden onset and is considered the most common cause of this pathology. It is caused by damage to cranial nerves VII, resulting in complete or partial paralysis of the facial mimic. May be associated with taste disturbances, salivation, tearing and hyperacusis. It is diagnosed after ruling out all possible etiologies, because its cause is not fully understood.Some researches shows that herpes virus may cause this type of palsy due to reactivation of the virus or by imunnomediated post-viral nerve demielinization. Physical therapy, corticosteroids and antiviral therapy have become the most widely accepted treatments for Bell's palsy. Therapy with low-level laser (LLLT) may induce the metabolism of injured nerve tissue for the production of proteins associated with its growth and to improve nerve regeneration. The success of the treatment of Bell's palsy by using laser phototherapy isolated or in association with other therapeutic approach has been reported on the literature. In most cases, the recovery occurs without uneventfully (complications), the acute illness is not associated with serious disorders. We will present a clinical approach for treating this condition.

  16. Combined laser and photodynamic treatment in extensive purulent wounds

    Science.gov (United States)

    Solovieva, A. B.; Tolstih, P. I.; Melik-Nubarov, N. S.; Zhientaev, T. M.; Kuleshov, I. G.; Glagolev, N. N.; Ivanov, A. V.; Karahanov, G. I.; Tolstih, M. P.; Timashev, P. S.

    2010-05-01

    Recently, photodynamic therapy (PDT) has been used for the treatment of festering wounds and trophic ulcers. An important advantage of PDT is its ability to affect bacterial cultures that are resistant to antibiotics. However the use of PDT alone does not usually guarantee a stable antiseptic effect and cannot prevent an external infection of wounds and burns. In this work attention is focused on the healing of the extensive soft tissues wounds with combined laser therapy (LT) and PDT treatment. At the first stage of this process festering tissues (for example spacious purulent wounds with area more than 100 cm2) were illuminated with high-energy laser beam (with power 20 W) in continues routine. The second stage involves “softer” PDT affect, which along with the completion stages of destruction pathological cells, stimulating the process of wound granulation and epithelization. Also, according to our previous results, photosensitizer (photoditazin) is introduced inside the wound with different amphiphilic polymers for increasing the PDT efficacy.

  17. [ISO 9001-2000 certification for refractive laser treatment].

    Science.gov (United States)

    Lebuisson, D A; Arson, B; Abenhaïm, A; Albou-Ganem, C; Assouline, M; Chong Sit, D; Danan, A; Montefiore, G; Montin, J-F; Nguyen-Khoa, J-L; Pietrini, D; Saragoussi, J-J; Trong, Th; Amar, R

    2005-05-01

    To obtain ISO 9001-2000 certification for laser corneal refractive treatment, never before sought in Europe. The consulting firm Veritas led the certification process with the clinic's staff manager. This ISO norm is dedicated to the implementation of a quality management system. We assessed and optimized all necessary resources, evaluating customer satisfaction using patient and referring-physician surveys. We started quality rounds including surgeons, nurses, and technicians. Based on this preparation, we redefined and explained all processes including staff responsibilities and necessary resources in the quality manual. The procedure lasted 14 months with substantial involvement on the part of the management. Unconditional ISO 9001-2000 certification was granted by the independent audit firm, BVQI, in december 2003 for refractive laser treatment. The 2000 version of the new ISO 9001-2000 seeks to meet the demand for improving health care delivery in this field, most particularly by establishing a clear procedural orientation. Such certification enhances team work, stabilizes methodologies, and reinforces cohesion and self-audit. Patients notice that the center follows a consistent quality policy and are assured that the clinic respects rules and regulations. Certification is an advantageous alternative when accreditation cannot be considered. Our article discusses the steps taken in upper management, quality management, procedural guidance, as well as customer and staff counselling. It also discusses the project's cost/benefit ratio for the organization.

  18. Modelling electroluminescence in liquid argon

    International Nuclear Information System (INIS)

    Stewart, D Y; Barker, G J; Bennieston, A J; Harrison, P F; McConkey, N; Morgan, B; Ramachers, Y A; Lightfoot, P K; Robinson, M; Spooner, N J C; Thompson, L

    2010-01-01

    We present Monte-Carlo simulations of electron transport through liquid argon motivated by our recent observation of electroluminescence light emanating from a thick gaseous electron multiplier (THGEM) in a liquid argon volume. All known elastic and inelastic reaction cross-sections have been accounted for, providing electroluminescence light yield predictions for arbitrary electrostatic fields. This study concludes that the large field gradients needed to produce electroluminescence cannot be accounted for by straightforward electrostatic field calculations based on ideal THGEM holes, suggesting that further experimental investigations are required.

  19. Laser in situ keratomileusis enhancements with the Ziemer FEMTO LDV femtosecond laser following previous LASIK treatments.

    Science.gov (United States)

    Pietilä, Juhani; Huhtala, Anne; Mäkinen, Petri; Uusitalo, Hannu

    2013-02-01

    The aim of this paper is to present the accuracy, predictability, and safety outcomes of LASIK enhancements performed with the FEMTO LDV femtosecond laser (Ziemer Ophthalmic Systems, Port, Switzerland) and the Allegretto Wave Concerto 500 Hz excimer laser (Wavelight AG, Erlangen, Germany), following previous LASIK treatments. FEMTO LDV was used for flap creation in 85 previously LASIK-treated eyes of 62 patients. The intended flap thickness was 90 μm in 81 eyes and 140 μm in 4 eyes. The size of the suction ring was 9.0 mm in 72 eyes and 9.5 mm in 13 eyes. Flap dimensions were measured and correlated to preoperative characteristics. With the intended flap thickness of 90 μm in previously LASIK-treated eyes, the actual flap thickness was 90.2 ± 6.6 μm (range 80-122), and the flap diameter was 9.2 ± 0.2 mm (range 8.7-9.9). The mean hinge length was 4.0 ± 0.2 mm (range 3.0-4.8). Flap thickness correlated positively with patient age and hinge length. Complications were reported in 12 eyes (14.1 %). Most of the complications were very mild, and none of them prevented further refractive laser treatment. One eye lost two Snellen lines of best spectacle-corrected visual acuity. Femtosecond LASIK enhancement is warranted only in rare cases. Surgical experience is needed and special caution must be practiced. For cases of a primary free cap, femtosecond LASIK is not recommended.

  20. Trapping cold ground state argon atoms for sympathetic cooling of molecules

    OpenAIRE

    Edmunds, P. D.; Barker, P. F.

    2014-01-01

    We trap cold, ground-state, argon atoms in a deep optical dipole trap produced by a build-up cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of co-trapped metastable argon atoms using a new type of parametric loss spectroscopy. Using this technique we als...

  1. Changes in nail keratin observed by Raman spectroscopy after Nd:YAG laser treatment.

    Science.gov (United States)

    Shin, Min Kyung; Kim, Tae In; Kim, Wan Sun; Park, Hun-Kuk; Kim, Kyung Sook

    2017-04-01

    Lasers and photodynamic therapy have been considered a convergence treatment for onychomycosis, which is a fungal infection on the nail bed and nail plate. Laser therapies have shown satisfactory results without significant complications for onychomycosis; however, the mechanism of clearing remains unknown. In this work, we investigated changes in the chemical structure of nail keratin induced by Nd:YAG laser using Raman spectroscopy. Toe nails with onychomycosis were treated with 1064 nm Nd:YAG laser. After laser treatment, the disulfide band (490-590 cm -1 ) of nail keratin was rarely observed or was reduced in intensity. The amide I band (1500-1700 cm -1 ) also showed changes induced by the laser. The α-helical (1652 cm -1 ) structures dominated the β-sheet (1673 cm -1 ) in nontreated nail, but the opposite phenomenon was observed after laser treatment. © 2016 Wiley Periodicals, Inc.

  2. [Laser thermokeratoplasty in the treatment of hyperopia in children].

    Science.gov (United States)

    Kulikova, I L; Pashtaev, N P; Suslikov, S V

    2006-01-01

    The effectiveness, safety, and stability of multimodality treatment for hyperopia, hyperopic and mixed astigmatism complicated by amblyopia and anisometropia were studied in 117 patients (117 eyes) aged 9 to 16 years, by using the new laser units "Lik-100" and "Glasser" at 1.54 microm. The patients were divided into 3 groups: 1) 43 patients (43 eyes) with hyperopia, spheric anisometropia and amblyopia; 2) 38 patients (38 eyes) with hyperopia, simple and complicated hyperopic astigmatism, astigmatic anisometropia, and amblyopia; 3) 36 patients (36 eyes) with hyperopia, simple and complicated hyperopic astigmatism, mixed anisometropia, and amblyopia. All the groups underwent multimodality treatment involving laser thermokeratoplasty and drug therapy for amblyopia. In children and adolescents, the refraction effect was 2.99 and 3.61 (mean 3.37 +/- 0.60) diopters, respectively. Astigmatism diminished by 2.01 diopters (63%) in children and by 2.62 diopters (79%) in adolescents (mean 2/35 diopters). The predictability of a refraction effect in the range of +/- 0.5 diopters averaged 77% in all the groups. Anisometropia diminished by an average of 2.88 +/- 0.8 diopters, which was 85% of the baseline data (the upper range of residual refraction was not more than 1.5 diopters. In all the groups, uncorrectable visual acuity increased by an average of 0.36 diopters (0.43 and 0.4 diopters in children and adolescents, respectively); correctable visual acuity increased by an average of 0.22 diopters (0.36 and 0.31 diopters in children and adolescents, respectively). Loss of correctable visual acuity lines did not greater than 2.7% (5 eyes). That of endothelial cells was not more than 6-8%. The angle of squint strabismus could be decreased or corrected in 79% after treatment. Binocular vision restored in 57%.

  3. The Dose That Works: Low Level Laser Treatment of Tendinopathy

    International Nuclear Information System (INIS)

    Tumilty, Steve; Munn, Joanne; David Baxter, G.; McDonough, Suzanne; Hurley, Deirdre A.; Basford, Jeffrey R.

    2010-01-01

    Background: Low Level Laser Therapy (LLLT) is used in the treatment of tendon injuries. However, the clinical effectiveness of this modality remains controversial with limited agreement on the most efficacious dosage and parameter choices. Purpose: To assess the clinical effectiveness of LLLT in the treatment of tendinopathy and the validity of current dosage recommendations for treatment. Method: Medical databases were searched from inception to 1st August 2008. Controlled clinical trials evaluating LLLT as a primary intervention for any tendinopathy were included in the review. Methodological quality was classified using the PEDro scale. Appropriateness of treatment parameters were assessed using established guidelines. Results: Twenty five trials met the inclusion criteria. There was conflicting findings from multiple trials: 12 showed positive effects and 13 were inconclusive or showed no effect. Dosages used in the 12 positive studies support the existence of an effective dosage window that closely resembled current guidelines. Where pooling of data was possible, LLLT showed a positive effect size; in high quality studies of lateral epicondylitis, participants' grip strength was 9.59 Kg higher than the control group; for participants with Achilles tendinopathy, the effect was 13.6 mm less pain on a 100 mm visual analogue scale. Conclusion: This study found conflicting evidence as to the effectiveness of LLLT in the treatment of tendinopathy. However, an effective dosage window emerged showing benefit in the treatment of tendinopathy. Strong evidence exists from the 12 positive studies that positive outcomes are associated with the use of current dosage recommendations for the treatment of tendinopathy.

  4. The Dose That Works: Low Level Laser Treatment of Tendinopathy

    Science.gov (United States)

    Tumilty, Steve; Munn, Joanne; McDonough, Suzanne; Hurley, Deirdre A.; Basford, Jeffrey R.; David Baxter, G.

    2010-05-01

    Background: Low Level Laser Therapy (LLLT) is used in the treatment of tendon injuries. However, the clinical effectiveness of this modality remains controversial with limited agreement on the most efficacious dosage and parameter choices. Purpose: To assess the clinical effectiveness of LLLT in the treatment of tendinopathy and the validity of current dosage recommendations for treatment. Method: Medical databases were searched from inception to 1st August 2008. Controlled clinical trials evaluating LLLT as a primary intervention for any tendinopathy were included in the review. Methodological quality was classified using the PEDro scale. Appropriateness of treatment parameters were assessed using established guidelines. Results: Twenty five trials met the inclusion criteria. There was conflicting findings from multiple trials: 12 showed positive effects and 13 were inconclusive or showed no effect. Dosages used in the 12 positive studies support the existence of an effective dosage window that closely resembled current guidelines. Where pooling of data was possible, LLLT showed a positive effect size; in high quality studies of lateral epicondylitis, participants' grip strength was 9.59 Kg higher than the control group; for participants with Achilles tendinopathy, the effect was 13.6 mm less pain on a 100 mm visual analogue scale. Conclusion: This study found conflicting evidence as to the effectiveness of LLLT in the treatment of tendinopathy. However, an effective dosage window emerged showing benefit in the treatment of tendinopathy. Strong evidence exists from the 12 positive studies that positive outcomes are associated with the use of current dosage recommendations for the treatment of tendinopathy.

  5. Electron scattering and transport in liquid argon

    International Nuclear Information System (INIS)

    Boyle, G. J.; Cocks, D. G.; White, R. D.; McEachran, R. P.

    2015-01-01

    The transport of excess electrons in liquid argon driven out of equilibrium by an applied electric field is revisited using a multi-term solution of Boltzmann’s equation together with ab initio liquid phase cross-sections calculated using the Dirac-Fock scattering equations. The calculation of liquid phase cross-sections extends previous treatments to consider multipole polarisabilities and a non-local treatment of exchange, while the accuracy of the electron-argon potential is validated through comparison of the calculated gas phase cross-sections with experiment. The results presented highlight the inadequacy of local treatments of exchange that are commonly used in liquid and cluster phase cross-section calculations. The multi-term Boltzmann equation framework accounting for coherent scattering enables the inclusion of the full anisotropy in the differential cross-section arising from the interaction and the structure factor, without an a priori assumption of quasi-isotropy in the velocity distribution function. The model, which contains no free parameters and accounts for both coherent scattering and liquid phase screening effects, was found to reproduce well the experimental drift velocities and characteristic energies

  6. Electron scattering and transport in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, G. J.; Cocks, D. G.; White, R. D. [College of Science, Technology and Engineering, James Cook University, Townsville 4810 (Australia); McEachran, R. P. [Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2015-04-21

    The transport of excess electrons in liquid argon driven out of equilibrium by an applied electric field is revisited using a multi-term solution of Boltzmann’s equation together with ab initio liquid phase cross-sections calculated using the Dirac-Fock scattering equations. The calculation of liquid phase cross-sections extends previous treatments to consider multipole polarisabilities and a non-local treatment of exchange, while the accuracy of the electron-argon potential is validated through comparison of the calculated gas phase cross-sections with experiment. The results presented highlight the inadequacy of local treatments of exchange that are commonly used in liquid and cluster phase cross-section calculations. The multi-term Boltzmann equation framework accounting for coherent scattering enables the inclusion of the full anisotropy in the differential cross-section arising from the interaction and the structure factor, without an a priori assumption of quasi-isotropy in the velocity distribution function. The model, which contains no free parameters and accounts for both coherent scattering and liquid phase screening effects, was found to reproduce well the experimental drift velocities and characteristic energies.

  7. Improvement of the technique in treatment of internal hemorrhoids with Nd:YAG laser

    Science.gov (United States)

    Bao, Xiao-qing; Zhu, Jing; Shi, Hong-Min

    2005-07-01

    Objective: To observe and study the improvement of the technique in treatment of internal hemorrhoids with Nd:YAG laser and evaluate the effective rate. Methods: 60 patients of internal hemorrhoids were treated with Nd:YAG laser (10-15mw) irradiating on the mucosa of the lesions. Results: Among 60 patients, 57 patients were primarily cured with one treatment, 3 patients were primarily cured with two treatments. The effective rate was 95% with one treatment, and it reached to 100% with two treatments. Conclusions: the improvement of the technique in treatment of internal hemorrhoids with Nd:YAG laser is effective and easy to operate.

  8. A comparison of diode laser and Er:YAG lasers in the treatment of gingival melanin pigmentation.

    Science.gov (United States)

    Simşek Kaya, Göksel; Yapici Yavuz, Günay; Sümbüllü, Muhammed A; Dayi, Ertunç

    2012-03-01

    This study compared the use of diode and Er:YAG lasers in treating gingival melanin pigmentation (GMP) in terms of gingival depigmentation, local anesthesia requirements, postoperative pain/discomfort, depigmentation effectiveness, and total treatment duration. Twenty patients (13 female, 7 male) referred with GMP were enrolled in the study. Patients were randomly divided into 2 groups. Group 1 was treated with a gallium aluminum arsenide diode laser with a continuous wavelength of 808 nm, and group 2 was treated with an Er:YAG laser with a continuous wavelength of 2,940 nm. Gingival depigmentation was performed by applying the laser at 1 W. Treatment was administered on a weekly basis until a normal pink gingival color was observable in clinical examination and photographs. In addition, patients were asked to evaluate the procedure by using a self-administered questionnaire. Procedures were carried out without the need for any topical or local anesthetic, and no unpleasant events occurred during the actual procedure or the healing period. The total length of treatment was significantly shorter with the diode laser (group 1) than with the Er:YAG laser (group 2; P Diode and Er:YAG lasers administered at 1 W both result in satisfactory depigmentation of GMP. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Geminate recombination in liquid argon

    International Nuclear Information System (INIS)

    Freeman, G.R.

    1984-01-01

    The extended Onsager model for geminate neutralization is supported by the field dependence of the ionization yield in liquid argon irradiated by high energy electrons or x rays. Attempts to employ the model fail unless the distribution of initial separation distances between the thermalized electrons and their sibling ions (secondary electron thermalization ranges) is included. Data of Scalettar and co-workers are reanalyzed

  10. Investigations into localized re-treatment of the retina with a 3-nanosecond laser.

    Science.gov (United States)

    Chidlow, Glyn; Plunkett, Malcolm; Casson, Robert J; Wood, John P M

    2016-08-01

    Subvisual retinal lasers necessarily cause clinically invisible lesions, hence, they could intentionally or inadvertently be targeted at precisely the same or an overlapping location during repeat laser treatment. Herein, we investigated the structural integrity and cellular responses of localized re-treatment using a nanosecond laser (2RT) currently in trials for early age-related macular degeneration. Rats were randomly assigned to one of five groups: sham, subvisual 2RT, subvisual 2RT re-treatment, visual effect 2RT, visual effect 2RT re-treatment. Re-treatment groups were lasered on days 0 and 21; single laser groups were only lasered on day 21. All rats were euthanized at day 28 and eyes were then dissected and processed for immunohistochemistry. For re-treatment, the laser was targeted at precisely the same locations on both delivery occasions. Analytical endpoints included monitoring of retinal vascular integrity overlying lesions, investigation into any potential choroidal neovascularization, assessment of the RPE, quantification of collateral injury to photoreceptors or other neuronal classes, and delineation of glial reactivity. Repeat laser administration to rats caused ostensibly identical retinal-RPE-choroid responses to those obtained in age-matched rats that received only a single application. Specifically, 7 days after treatment, RPE cells were re-populating lesion sites. No obvious consistent differences were evident between the single and repeat laser groups. Moreover, repeat laser caused no (measurable) additive injury to photoreceptors or other retinal neuronal classes from single laser treatment. In re-lasered animals, there was no increase in microglial activity overlying and adjacent to lesion sites relative to single lasered rats. Finally, there was no evidence of choroidal neovascularization after repeat laser treatment. The overall results provide a measure of confidence that re-treatment of patients with 2RT should not provide any

  11. Genomic Physics. Multiple Laser Beam Treatment of Alzheimer's Disease

    Science.gov (United States)

    Stefan, V. Alexander

    2014-03-01

    The synapses affected by Alzheimer's disease can be rejuvenated by the multiple ultrashort wavelength laser beams.[2] The guiding lasers scan the whole area to detect the amyloid plaques based on the laser scattering technique. The scanning lasers pinpoint the areas with plaques and eliminate them. Laser interaction is highly efficient, because of the focusing capabilities and possibility for the identification of the damaging proteins by matching the protein oscillation eigen-frequency with laser frequency.[3] Supported by Nikola Tesla Labs, La Jolla, California, USA.

  12. Fractional CO2 lasers contribute to the treatment of stable non-segmental vitiligo.

    Science.gov (United States)

    Yuan, Jinping; Chen, Hongqiang; Yan, Ru; Cui, Shaoshan; Li, Yuan-Hong; Wu, Yan; Gao, Xing-Hua; Chen, Hong-Duo

    2016-12-01

    Stable non-segmental vitiligo is often resistant to conventional therapies. The purpose of this study was to investigate the effect of three types of fractional lasers in the treatment of stable non-segmental vitiligo. Twenty patients were enrolled in the study. The vitiligo lesions of each patient were divided into four treatment parts, and all parts were treated with narrowband ultraviolet-B (NB-UVB). Three of the four parts were respectively treated with three types of fractional lasers (two ablative 10,600-nm CO 2 lasers and one non-ablative 1,565-nm laser), followed by topical betamethasone solution application. The treatment period lasted six months. Efficacy and satisfaction were respectively assessed by dermatologists and patients. The ablative CO 2 lasers, in combination with topical betamethasone solution and NB-UVB, achieved marked to excellent improvement on white patches assessed by dermatologists. Patients showed high satisfaction scores for the treatments. The non-ablative 1,565-nm fractional laser did not provide any further benefit in the treatment of vitiligo. No severe adverse events developed for any of the treatments. The treatment protocol with ablative CO 2 lasers, in combination with topical betamethasone solution and NB-UVB, was suitable for stable non-segmental vitiligo. For vitiligo, the ablative fractional CO 2 laser is more effective than the non-ablative fractional laser.

  13. Bleaching Dengan Teknologi Laser

    OpenAIRE

    Eliwaty

    2008-01-01

    Penulisan tentang bleaching dengan laser dimaksudkan untuk menambah wawasan serta pengetahuan dari pembaca di bidang kedokteran gigi. Macam-macam laser yang dipergunakan dalam bleaching yaitu argon, CO2 serta dioda laser. Contoh merek produk laser yaitu Blulaze, Dentcure untuk argonlaser, Novapulse untuk C02 serta Opus 5 untuk dioda laser. Laser bleaching hasilnya dapat dicapai dalam satu kunjungan saja, cepat, efisien namun biayanya relatif mahal, dapat menimbulkan burn, sensitivitas se...

  14. Laser surgery in ear, nose and throat

    International Nuclear Information System (INIS)

    Winter, F.Oe.; Teig, E.; Haye, R.

    1991-01-01

    This survey is based on own experiences and a study of the literature. The CO 2 laser has certain advantages in the surgical treatment of otosclerosis, both in the primary operation and in reoperation. In rhinal surgery the argon laser has been used with good results in Osler's disease. Laser surgery is not recommended for vasomotoric rhinitis and polyposis. The CO-2 laser has improved the quality of treatment of laryngeal papilloma. With high precision and minimal bleeding the postoperative voice is better than with conventional surgery. The CO 2 laser can also be used to exstirpate small malignant tumours of the tongue and leukoplasia of the oral mucosa. Healing is rapid and involves relatively little pain. The postoperative functional results is usually good, due to moderate formation of scars. 11 refs., 2 tabs

  15. Behavior of Excited Argon Atoms in Inductively Driven Plasmas

    CERN Document Server

    Hebner, G A

    1999-01-01

    Laser induced fluorescence has been used to measure the spatial distribution of the two lowest energy argon excited states, 1s sub 5 and 1s sub 4 , in inductively driven plasmas containing argon, chlorine and boron trichloride. The behavior of the two energy levels with plasma conditions was significantly different, probably because the 1s sub 5 level is metastable and the 1s sub 4 level is radiatively coupled to the ground state but is radiation trapped. The argon data is compared with a global model to identify the relative importance of processes such as electron collisional mixing and radiation trapping. The trends in the data suggest that both processes play a major role in determining the excited state density. At lower rfpower and pressure, excited state spatial distributions in pure argon were peaked in the center of the discharge, with an approximately Gaussian profile. However, for the highest rfpowers and pressures investigated, the spatial distributions tended to flatten in the center of the disch...

  16. New laser sources for clinical treatment and diagnostics of neonatal jaundice

    Science.gov (United States)

    Hamza, Mostafa; El-Ahl, Mohammad H. S.; Hamza, Ahmad M.

    2001-06-01

    An elevated serum bilirubin concentration in the newborn infant presents a therapeutic as well as a diagnostic problem to the physician. It has long been recognized that high levels of bilirubin cause irreversible brain damage and even death. The authors introduce the use of semiconductor diode lasers and diode-pumped solid-state lasers that can be used for solving such diagnostic and therapeutic problems. These new laser sources can improve the ergonomics of using laser, enhance performance capabilities and reduce the cost of employing laser energy to pump bilirubin out of an infant's body. The choice of laser wavelengths follows the principles of bilirubinometry and phototherapy of neonatal jaundice. The wide spread use of these new laser sources for clinical monitoring and treatment of neonatal hyperbilirubinemia will be made possible as each incremental or quantum jump cost reduction is achieved. Our leading clinical experience as well as the selection rules of laser wavelengths will be presented.

  17. Non-invasive determination of port wine stain anatomy and physiology for optimal laser treatment strategies

    NARCIS (Netherlands)

    van Gemert, M. J.; Nelson, J. S.; Milner, T. E.; Smithies, D. J.; Verkruysse, W.; de Boer, J. F.; Lucassen, G. W.; Goodman, D. M.; Tanenbaum, B. S.; Norvang, L. T.; Svaasand, L. O.

    1997-01-01

    The treatment of port wine stains (PWSs) using a flashlamp-pumped pulsed dye laser is often performed using virtually identical irradiation parameters. Although encouraging clinical results have been reported, we propose that lasers will only reach their full potential provided treatment parameters

  18. Improve the material absorption of light and enhance the laser tube bending process utilizing laser softening heat treatment

    Science.gov (United States)

    Imhan, Khalil Ibraheem; Baharudin, B. T. H. T.; Zakaria, Azmi; Ismail, Mohd Idris Shah B.; Alsabti, Naseer Mahdi Hadi; Ahmad, Ahmad Kamal

    2018-02-01

    Laser forming is a flexible control process that has a wide spectrum of applications; particularly, laser tube bending. It offers the perfect solution for many industrial fields, such as aerospace, engines, heat exchangers, and air conditioners. A high power pulsed Nd-YAG laser with a maximum average power of 300 W emitting at 1064 nm and fiber-coupled is used to irradiate stainless steel 304 (SS304) tubes of 12.7 mm diameter, 0.6 mm thickness and 70 mm length. Moreover, a motorized rotation stage with a computer controller is employed to hold and rotate the tube. In this paper, an experimental investigation is carried out to improve the laser tube bending process by enhancing the absorption coefficient of the material and the mechanical formability using laser softening heat treatment. The material surface is coated with an oxidization layer; hence, the material absorption of laser light is increased and the temperature rapidly rises. The processing speed is enhanced and the output bending angle is increased to 1.9° with an increment of 70% after the laser softening heat treatment.

  19. Current treatments of acne: Medications, lights, lasers, and a novel 650-μs 1064-nm Nd: YAG laser.

    Science.gov (United States)

    Gold, Michael H; Goldberg, David J; Nestor, Mark S

    2017-09-01

    The treatment of acne, especially severe acne, remains a challenge to dermatologists. Therapies include retinoids, antibiotics, hormones, lights, lasers, and various combinations of these modalities. Acne is currently considered a chronic rather than an adolescent condition. The appropriate treatment depends on the patient and the severity of disease. The purpose of this study was to review current therapies for acne of all severities and to introduce the 650-μs 1064-nm laser for the treatment of acne. © 2017 Wiley Periodicals, Inc.

  20. Laser treatment of a neodymium magnet and analysis of surface characteristics

    Science.gov (United States)

    Yilbas, B. S.; Ali, H.; Rizwan, M.; Kassas, M.

    2016-08-01

    Laser treatment of neodymium magnet (Nd2Fe14B) surface is carried out under the high pressure nitrogen assisting gas. A thin carbon film containing 12% WC carbide particles with 400 nm sizes are formed at the surface prior to the laser treatment process. Morphological and metallurgical changes in the laser treated layer are examined using the analytical tools. The corrosion resistance of the laser treated surface is analyzed incorporating the potentiodynamic tests carried out in 0.05 M NaCl+0.1 M H2SO4 solution. The friction coefficient of the laser treated surface is measured using the micro-scratch tester. The wetting characteristics of the treated surface are assessed incorporating the sessile water drop measurements. It is found that a dense layer consisting of fine size grains and WC particles is formed in the surface region of the laser treated layer. Corrosion resistance of the surface improves significantly after the laser treatment process. Friction coefficient of laser treated surface is lower than that of the as received surface. Laser treatment results in superhydrophobic characteristics at the substrate surface. The formation of hematite and grain size variation in the treated layer slightly lowers the magnetic strength of the laser treated workpiece.

  1. Stem Cell Physics. Multiple-Laser-Beam Treatment of Parkinson's Disease

    Science.gov (United States)

    Stefan, V.

    2013-03-01

    A novel method for the treatment of Parkinson's disease is proposed. Pluripotent stem cells are laser cultured, using ultrashort wavelength, (around 0.1 micron-ultraviolet radiation-with intensities of a few mW/cm2) , multiple laser beams.[2] The multiple-energy laser photons[3] interact with the neuron DNA molecules to be cloned. The laser created dopaminergic substantia nigra neurons can be, (theoretically), laser transplanted, (a higher focusing precision as compared to a syringe method), into the striatum or substantia nigra regions of the brain, or both. Supported by Nikola Tesla Labs, Stefan University.

  2. A comparative study of pulsed dye laser versus long pulsed Nd:YAG laser treatment in recalcitrant viral warts.

    Science.gov (United States)

    Shin, Yo Sup; Cho, Eun Byul; Park, Eun Joo; Kim, Kwang Ho; Kim, Kwang Joong

    2017-08-01

    Viral warts are common infectious skin disease induced by human papillomavirus (HPV). But the treatment of recalcitrant warts is still challenging. In this study, we compared the effectiveness of pulsed dye laser (PDL) and long pulsed Nd:YAG (LPNY) laser in the treatment of recalcitrant viral warts. We retrospectively analyzed the medical records of patients with recalcitrant warts treated with laser therapy between January 2013 and February 2016. Seventy-two patients with recalcitrant warts were evaluated. Thirty-nine patients were treated with pulsed dye laser and thirty-three patients were treated with LPNY laser. The following parameters were used: PDL (spot size, 7 mm; pulse duration, 1.5 ms; and fluence, 10-14 J/cm 2 ) and LPNY (spot size, 5 mm; pulse duration, 20 ms; and fluence, 240-300 J/cm 2 ). Complete clearance of two patients (5.1%) in PDL group, and three patients (9.1%) in LPNY group were observed without significant side effects. The patients who achieved at least 50% improvement from baseline were 20 (51.3%) in PDL and 22 (66.7%) in LPNY, respectively. This research is meaningful because we compared the effectiveness of the PDL and LPNY in the recalcitrant warts. Both PDL and LPNY laser could be used as a safe and alternative treatment for recalcitrant warts.

  3. Fractional CO2 laser is as effective as Q-switched ruby laser for the initial treatment of a traumatic tattoo.

    Science.gov (United States)

    Seitz, Anna-Theresa; Grunewald, Sonja; Wagner, Justinus A; Simon, Jan C; Paasch, Uwe

    2014-12-01

    Q-switched laser treatments are considered the standard method for removing both regular and traumatic tattoos. Recently, the removal of tattoo ink using ablative fractional lasers has been reported. Ablative fractional CO2 laser and q-switched ruby laser treatments were used in a split-face mode to compare the safety and efficacy of the two types of laser in removing a traumatic tattoo caused by the explosion of a firework. A male patient suffering from a traumatic tattoo due to explosive deposits in his entire face was subjected to therapy. A series of eleven treatments were performed. The right side of the face was always treated using an ablative fractional CO2 laser, whereas the left side was treated only using a q-switched ruby laser. After a series of eleven treatments, the patient demonstrated a significant lightening on both sides of his traumatic tattoo, with no clinical difference. After the first six treatments, the patient displayed greater lightening on the right side of his face, whereas after another five treatments, the left side of the patient's face appeared lighter. No side effects were reported. In the initial stage of removing the traumatic tattoo, the ablative fractional laser treatment appeared to be as effective as the standard ruby laser therapy. However, from the 6th treatment onward, the ruby laser therapy was more effective. Although ablative fractional CO2 lasers have the potential to remove traumatic tattoos, they remain a second-line treatment option.

  4. Test results of the experimental laser device for potato tubers radiation treatment

    International Nuclear Information System (INIS)

    Anufrik, S.S.; Korzun, O.S.

    2007-01-01

    Results of 3 year investigation of the influence of the presowing low intensity laser radiation treatment of potato (Solanum tuberosum L.) tubers with the help of laser device with various spectral composition and exposition on plant growth, development and productivity and potato tubers quality and starch content in the conditions of the Republic of Belarus were presented. Presowing tubers treatment of potato cultivars Sante, Yavar and Arkhideya was realized by He-Ne, Ar-, Cu (in course of 3 and 5 minutes) and CO2 (in course of 5 seconds) lasers. Research results have shown that presowing treatment with CO2 laser promoted the higher (on 1,7-6,6%) potato germination capacity in comparison with the control variant without radiation treatment. Height of potato plants of Sante variety after radiation treatment fell behind the control ones. Haulm quantity per one plant and yield quality did not depend on radiation treatment Treatment with CO2 laser exercised the stimulatory action on productivity of Sante variety without changing the starch content in tubers. Tuber weight increased up to 0,4 kg (0,2 kg in the control variant). Similar effect for Arkhideya and Yavar varieties was obtained after Cu-laser treatment in course of 5 minutes. Radiation treatment with He-Ne laser caused the increased starch accumulation (on 0,4-0,6% in comparison with the control variant) in potato tubers of all studied varieties

  5. Combination treatment with excimer laser and narrowband UVB light in vitiligo patients.

    Science.gov (United States)

    Shin, Sungsik; Hann, Seung-Kyung; Oh, Sang Ho

    2016-01-01

    For the treatment of vitiligo, narrowband UVB (NBUVB) light is considered the most effective for nonsegmental vitiligo, while excimer laser treatment is commonly used for localized vitiligo. However, treatment areas may potentially be missed with excimer laser treatment. We aimed to evaluate the effect of combinational treatment with NBUVB light and excimer laser on vitiligo. All patients were first treated with NBUVB; excimer laser was then applied in conjunction with NBUVB phototherapy due to a slow response or no further improvement with continuous NBUVB treatment alone. To minimize adverse effects, a fixed dose of NBUVB was administered, and the dose of excimer laser was increased based on patient response. Among 80 patients, 54 patients showed responses after combination with excimer laser; however, 26 patients (32.5%) showed no remarkable change after combination therapy. Of the 26 patients who showed no further response, 12 patients (46.1%) presented with vitiligo on the acral areas, which are known to the least responsive sites. Our study suggests that combined treatment of NBUVB and excimer laser in vitiligo may enhance the treatment response without remarkable side effects, therefore might also increase the compliance of the patients to the treatment. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Laser irradiation of penile blood as treatment of sexual dysfunctions

    Science.gov (United States)

    Koultchavenia, Ekaterina V.; Khomyakov, Victor T.

    2001-05-01

    40-60% of the men of average age suffer from the violations of sexual functions. Impotence doesn't make direct threat to life; nevertheless this disease essentially reduces quality of life, and consequently deserves the most steadfast attention. There are many methods of treatment of erectile dysfunction. However they are connected with a reception of medicines, which is expensive and has a number of contraindications, or with invasive procedures, or with surgical intervention, that also not always is desirable. We have developed the original device permitting to cause passive erection by creation of a local decompression. The second stage is the effect by an infrared laser radiation (denseness of a potency 4.2 mWt/sm2, continuous radiation with length of a wave 0.89 microns, exposition 5 minutes) on erection glans penis. We observed 24 patients with the complaints on insufficient erection (18), premature ejaculation (6); 2 patients in addition presented the complaint on small sizes of the penis. Age of the patients was 24-46 years, on the average 34.3 years. All have received treatment from 15 sessions in day.

  7. Lasers in primary open angle glaucoma

    Directory of Open Access Journals (Sweden)

    Sihota Ramanjit

    2011-12-01

    Full Text Available Lasers have been used in the treatment of primary open angle glaucoma (POAG over the years, with the hope that they would eventually replace medical and surgical therapy. Laser trabeculoplasty (LT is an application of argon, diode, or selective laser energy to the surface of the trabecular meshwork to increase the aqueous outflow. The mechanisms by which intraocular pressure (IOP is lowered could be mechanical, biologic, or by division of adjacent cells. It is commonly used as an adjunct to medical therapy, but is contraindicated if the angle is obstructed, e.g., peripheral anterior synechia (PAS or developmental glaucomas. About 75% of individuals will show a significant fall in IOP after argon laser trabeculoplasty (ALT, and the response is similar with selective laser trabeculoplasty (SLT. The effects of LT are not always long lasting, with about 10% of individuals showing a rise in IOP with every passing year. Laser thermal sclerostomy, ab interno or externo, is an alternative to other full-thickness filtration procedures. Longer wavelengths in the infrared range have water-absorptive characteristics that facilitate perforation of the sclera. These lasers can be used to avoid intraocular instrumentation and minimize conjunctival trauma.

  8. Liquid Argon Barrel Cryostat Arrived

    CERN Multimedia

    Pailler, P

    Last week the first of three cryostats for the ATLAS liquid argon calorimeter arrived at CERN. It had travelled for 46 days over several thousand kilometers from Japan to CERN. During three years it has been fabricated by Kawasaki Heavy Industries Ltd. at Harima, close to Kobe, under contract from Brookhaven National Laboratory (BNL) of the U.S.. This cryostat consists of two concentric cylinders made of aluminium: the outer vacuum vessel with a diameter of 5.5 m and a length of 7 m, and the inner cold vessel which will contain the electromagnetic barrel calorimeter immersed in liquid argon. The total weight will be 270 tons including the detectors and the liquid argon. The cryostat is now located in building 180 where it will be equipped with 64 feed-throughs which serve for the passage of 122,880 electrical lines which will carry the signals of the calorimeter. After integration of the calorimeter, the solenoidal magnet of ATLAS will be integrated in the vacuum vessel. A final cold test of the cryostat inc...

  9. APPLICATION OF PULSE-PERIODICAL MODE FOR IMPROVEMENT OF LASER TREATMENT EFFICIENCY

    Directory of Open Access Journals (Sweden)

    V. V. Apollonov

    2014-01-01

    Full Text Available The purpose of the paper is to estimate an application of pulse-periodical mode for improvement of laser treatment efficiency. Laser technologies have been widely used in the processes of material treatment with the purpose to provide them the required surface properties and also for high accuracy cutting of sheet materials. Application of complex treatment is of great interest and especially when it is used for worn-out surfaces with formation of a coating by gas-flame laying of powder mixture of specific composition and subsequent laser fusion.Increase of laser unit capacity is very important task for higher efficiency of laser technology application in mechanical engineering. Nowadays technological processes using lasers with high average power (more than 100 W have been applying only sources that are working in two modes, namely: continuous and pulse- periodical (P-P with pulse repetition rate from some units to several hundred hertz and pulse duration within dozens to hundreds of microseconds and even within milliseconds. On the other hand, in some cases shielding effect of plasma cloud formed during laser alloying, cladding or welding reduces the efficiency of laser treatment up to 50 % depending on plasma composition and laser beam length. High frequency P-P laser systems with high average power working in mode of Q-factor modulation allow to realize principally other mechanism of irradiation interaction with materials that is an ablation. In this case it is possible to provide local energy release both in space and time.The performed analysis has revealed that P-P mode of laser operation for a majority of treatment processes is much better and more efficient from energetic point of view in comparison with the continuous mode. On the basis of the developments it is possible to make a conclusion that there is a possibility to create laser systems working in high frequency P-P mode with high average power above hundreds watt.

  10. Hydrogen–argon plasma pre-treatment for improving the anti-corrosion properties of thin Al2O3 films deposited using atomic layer deposition on steel

    International Nuclear Information System (INIS)

    Härkönen, Emma; Potts, Stephen E.; Kessels, Wilhelmus M.M.; Díaz, Belén; Seyeux, Antoine; Światowska, Jolanta; Maurice, Vincent; Marcus, Philippe; Radnóczi, György; Tóth, Lajos; Kariniemi, Maarit; Niinistö, Jaakko; Ritala, Mikko

    2013-01-01

    The effect of H 2 –Ar plasma pre-treatment prior to thermal atomic layer deposition (ALD) and plasma-enhanced atomic layer deposition (PEALD) of Al 2 O 3 films on steel for corrosion protection was investigated. Time-of-flight secondary ion mass spectrometry and transmission electron microscopy were used to observe the changes in the interface. The electrochemical properties of the samples were studied with polarization measurements, and the coating porosities were calculated from the polarization results for easier comparison of the coatings. Prior to thermal ALD the plasma pre-treatment was observed to reduce the amount of impurities at the interface and coating porosity by 1–3 orders of magnitude. The anti-corrosion properties of the PEALD coatings could also be improved by the pre-treatment. However, exposure of the pre-treatment plasma activated steel surface to oxygen plasma species in PEALD led to facile oxide layer formation in the interface. The oxide layer formed this way was thicker than the native oxide layer and appeared to be detrimental to the protective properties of the coating. The best performance for PEALD Al 2 O 3 coatings was achieved when, after the plasma pre-treatment, the surface was given time to regrow a thin protective interfacial oxide prior to exposure to the oxygen plasma. The different effects that thermal and plasma-enhanced ALD have on the substrate-coating interface were compared. The reactivity of the oxygen precursor was shown to have a significant influence on substrate surface in the early stages of film growth and thereafter also on the overall quality of the protective film. - Highlights: • Influence of H 2 –Ar plasma pre-treatment to ALD coatings on steel was studied. • The pre-treatment modified the coating–substrate interface composition and thickness. • The pre-treatment improved the barrier properties of the coatings

  11. Muscle relaxation for individuals having tattoos removed through laser treatment: possible effects regarding anxiety and pain.

    Science.gov (United States)

    Huang, Faye; Chou, Wen-Jiun; Chen, Tien-Hsing; Chen, Ching; Hsieh, Yu-Lian; Chong, Mian-Yoon; Hung, Chi-Fa; Lin, Shu-Ching; Tsai, Hsiu-Huang; Wang, Liang-Jen

    2016-08-01

    Effectively managing pain is vital for the well-being and satisfaction of patients undergoing dermatologic treatments involving lasers. This study investigates the potential outcome of using muscle relaxation techniques to reduce pain among people having their tattoos removed with laser treatment. This study consists of 56 participants (mean age 18.1 ± 2.1 years) that had tattoos removed using the principle of selective photothermolysis. These participants underwent muscle relaxation before receiving the laser treatment. Their peripheral skin temperatures (PST) were measured both at the beginning and the end of the muscle relaxation period. Then, the Beck Anxiety Inventory was applied to evaluate anxiety levels. Once the laser treatment was completed, pain levels were measured using a visual analogue scale. A total of 125 person-sessions of laser treatment and psychometric assessments were performed in this study. The muscle relaxation method significantly increased the PST of the participants while reducing the levels of anxiety and pain throughout the course of the laser treatment procedure. The PST, anxiety scores, and pain scores all showed significant correlations with one another. According to the results obtained, this study proposes that muscle relaxation techniques be considered possibly auxiliary treatment options for individuals having tattoos removed through laser treatment. Additional studies with a comparison group and a larger sample size are required in the future to confirm the effectiveness of such intervention.

  12. Measurement of the main and critical parameters for optimal laser treatment of heart disease

    Science.gov (United States)

    Kabeya, FB; Abrahamse, H.; Karsten, AE

    2017-10-01

    Laser light is frequently used in the diagnosis and treatment of patients. As in traditional treatments such as medication, bypass surgery, and minimally invasive ways, laser treatment can also fail and present serious side effects. The true reason for laser treatment failure or the side effects thereof, remains unknown. From the literature review conducted, and experimental results generated we conclude that an optimal laser treatment for coronary artery disease (named heart disease) can be obtained if certain critical parameters are correctly measured and understood. These parameters include the laser power, the laser beam profile, the fluence rate, the treatment time, as well as the absorption and scattering coefficients of the target treatment tissue. Therefore, this paper proposes different, accurate methods for the measurement of these critical parameters to determine the optimal laser treatment of heart disease with a minimal risk of side effects. The results from the measurement of absorption and scattering properties can be used in a computer simulation package to predict the fluence rate. The computing technique is a program based on the random number (Monte Carlo) process and probability statistics to track the propagation of photons through a biological tissue.

  13. Combined pulsed dye laser and fiberoptic Nd-YAG laser for the treatment of hypertrophic port wine stain.

    Science.gov (United States)

    Radmanesh, Mohammed; Radmanesh, Ramin

    2017-10-01

    The hypertrophic Port Wine Stain (PWS) is only partially and superficially treated with the Pulsed dye laser (PDL) because of its limited depth of penetration. We used combined PDL and fiberoptic 1444-nm Nd-YAG laser to treat a case with hypertrophic PWS. After tumescent anesthesia, few holes were made by a 16-gauge needle on different sides of the lesion. The fiberoptic tip of 1444-nm Nd-YAG laser was inserted within the holes and was pushed forward while triggering. In a fan pattern and by a back and forth movement, the subcutaneous and deep dermal areas were coagulated. The skin and outer mucosal surfaces were then treated by PDL. The fiberoptic system used was Accusculpt 1444-nm Nd-YAG laser (Lutronic lasers, South Korea), and the PDL used was 585 nm Nlite system (Chromogenex UK). The parameters used for PDL were fluence = 9 Joules/cm 2 and the spot size was 5 mm. The parameters used for fiberoptic 1444-nm Nd-YAG laser were: Pulse rate = 30 Hz, pulse energy = 300 mJ, power = 6 W, and the total energy = 4000 J for the whole face and mucosa. Little sign of regression and moderate purpura were detected immediately after combined fiberoptic Nd-YAG and PDL therapy. The lesion gradually regressed within 4 months with satisfactory color and volume change. Combined fiberoptic Nd-YAG laser and PDL can be used for the treatment of deeper and superficial layers of hypertrophic PWS.

  14. Excimer laser corneal surgery and free oxygen radicals.

    Science.gov (United States)

    Bilgihan, K; Bilgihan, A; Akata, F; Hasanreisoğlu, B; Türközkan, N

    1996-01-01

    Corneal photoablation with 193 nm argon fluoride excimer laser is a new technique for the treatment of refractive errors and for removing corneal opacities and irregularities. Ultraviolet radiation and thermal injury induce free radical formation in the tissues. The aim of this study was to confirm the production of free radicals by excimer laser photoablation in rabbits. The thermal changes of the posterior corneal surface were recorded during excimer laser photoablation. The lipid peroxide (LPO) levels and superoxide dismutase (SOD) activities of aqueous humour were measured after excimer laser keratectomy. The aqueous LPO levels were not changed after excimer laser ablation, but both the thermal increase in the cornea during the photoablation and the decreased aqueous SOD activities suggest that free radicals are formed in the cornea during excimer laser keratectomy, and that they may be responsible for some of the complications of excimer laser corneal surgery.

  15. OUTCOMES AFTER LASER VERSUS COMBINED LASER AND BEVACIZUMAB TREATMENT FOR TYPE 1 RETINOPATHY OF PREMATURITY IN ZONE I.

    Science.gov (United States)

    Yoon, Je Moon; Shin, Dong Hoon; Kim, Sang Jin; Ham, Don-Il; Kang, Se Woong; Chang, Yun Sil; Park, Won Soon

    2017-01-01

    To investigate the anatomical and refractive outcomes in patients with Type 1 retinopathy of prematurity in Zone I. The medical records of 101 eyes of 51 consecutive infants with Type 1 retinopathy of prematurity in Zone I were analyzed. Infants were treated by conventional laser photocoagulation (Group I), combined intravitreal bevacizumab injection and Zone I sparing laser (Group II), or intravitreal bevacizumab with deferred laser treatment (Group III). The proportion of unfavorable anatomical outcomes including retinal fold, disc dragging, retrolental tissue obscuring the view of the posterior pole, retinal detachment, and early refractive errors were compared among the three groups. The mean gestational age at birth and the birth weight of all 51 infants were 24.3 ± 1.1 weeks and 646 ± 143 g, respectively. In Group I, an unfavorable anatomical outcome was observed in 10 of 44 eyes (22.7%). In contrast, in Groups II and III, all eyes showed favorable anatomical outcomes without reactivation or retreatment. The refractive error was less myopic in Group III than in Groups I and II (spherical equivalent of -4.62 ± 4.00 D in Group I, -5.53 ± 2.21 D in Group II, and -1.40 ± 2.19 D in Group III; P prematurity in Zone I, intravitreal bevacizumab with concomitant or deferred laser therapy yielded a better anatomical outcome than conventional laser therapy alone. Moreover, intravitreal bevacizumab with deferred laser treatment resulted in less myopic refractive error.

  16. Laser therapy and sclerotherapy in the treatment of oral and maxillofacial hemangioma and vascular malformations

    Science.gov (United States)

    Crişan, Bogdan; BǎciuÅ£, Mihaela; BǎciuÅ£, Grigore; Crişan, Liana; Bran, Simion; Rotar, Horatiu; Moldovan, Iuliu; Vǎcǎraş, Sergiu; Mitre, Ileana; Barbur, Ioan; Magdaş, Andreea; Dinu, Cristian

    2016-03-01

    Hemangioma and vascular malformations in the field of oral and maxillofacial surgery is a pathology more often found in recent years in patients. The aim of this study was to evaluate the efficacy of the laser photocoagulation performed with a diode laser (Ga-Al-As) 980 nm wavelength in the treatment of vascular lesions which are located on the oral and maxillofacial areas, using color Doppler ultrasonography for evaluation of the results. We also made a comparison between laser therapy and sclerotherapy in order to establish treatment protocols and recommendations associated with this pathology. We conducted a controlled study on a group of 92 patients (38 male and 54 female patients, with an average age of 36 years) having low flow hemangioma and vascular malformations. Patients in this trial received one of the methods of treatment for vascular lesions such as hemangioma and vascular malformations: laser therapy or sclerotherapy. After laser therapy we have achieved a reduction in size of hemangioma and vascular malformations treated with such a procedure, and the aesthetic results were favorable. No reperfusion or recanalization of laser treated vascular lesions was observed after an average follow-up of 6 to 12 months. In case of sclerotherapy a reduction in the size of vascular lesions was also obtained. The 980 nm diode laser has been proved to be an effective tool in the treatment of hemangioma and vascular malformations in oral and maxillofacial area. Laser therapy in the treatment of vascular lesions was more effective than the sclerotherapy procedure.

  17. Early treatment using fractional CO2 laser before skin suture during scar revision surgery in Asians.

    Science.gov (United States)

    Du, Feiya; Yu, Yusheng; Zhou, Zhiqin; Wang, Liujia; Zheng, Shusen

    2018-04-01

    Fractional CO 2 laser is one of the most effective treatment options used to resurface scars. However, most previous studies have been performed on mature scars at least 2 months after surgery. Recent studies have emphasized the importance of early treatment to reduce scar formation. In the present study, we described our experience with fractional CO 2 laser intervention before skin suture during scar revision surgery in Asians, and found the treatment was safe and effective.

  18. Bacterial Adhesion on the Titanium and Stainless-Steel Surfaces Undergone Two Different Treatment Methods: Polishing and Ultrafast Laser Treatment

    Science.gov (United States)

    Chik, N.; Zain, W. S. Wan Md; Mohamad, A. J.; Sidek, M. Z.; Ibrahim, W. H. Wan; Reif, A.; Rakebrandt, J. H.; Pfleging, W.; Liu, X.

    2018-05-01

    Bacterial adhesion has become a significant problem in many industries causing billions of dollars for its complicated removal treatment and maintenance. In this study, metal surfaces undergone treatment with ultrafast laser with varies power. The microstructure produced on its original surfaces were expected to prevent the adhesion of Escherichia coli (E. coli) ATCC 8739 and Staphylococcus aureus (S. aureus) ATCC 6838. The laser treatment was performed at 380 fs pulse duration, 515 µm central wavelength and a repetition rate of 200 kHz. Stainless steel AISI 316L was treated with an average laser power of 0.04 W (SS-0.04) and 0.11 W (SS-0.11), while Grade 5 titanium alloy was tested with high laser power 0.11 W (T-0.11). The adhesion was observed after 16 hours and the number of adhering bacteria was counted per cm2. The result achieved shows that, increasing the average laser power is leading to an enhanced S. aureus adhesion while E. coli adhesion is reduced which is due to the hydrophobicity interaction and difference in surface texture. Meanwhile, the laser treatment showed significant reduction of the bacterial adhesion on its surface compared to the polished surfaces. Thus, ultrafast laser texturing can be suggested as a promising method to reduce the bacterial adhesion, which reduced the adhesion of >80% for E. coli and >20% for S. aureus.

  19. Laser scanning dental probe for endodontic root canal treatment

    Science.gov (United States)

    Blank, Molly A. B.; Friedrich, Michal; Hamilton, Jeffrey D.; Lee, Peggy; Berg, Joel; Seibel, Eric J.

    2011-03-01

    Complications that arise during endodontic procedures pose serious threats to the long-term integrity and health of the tooth. Potential complexities of root canals include residual pulpal tissue, cracks, mesial-buccal 2 and accessory canals. In the case of a failed root canal, a successful apicoectomy can be jeopardized by isthmuses, accessory canals, and root microfracture. Confirming diagnosis using a small imaging probe would allow proper treatment and prevent retreatment of endodontic procedures. An ultrathin and flexible laser scanning endoscope of 1.2 to 1.6mm outer diameter was used in vitro to image extracted teeth with varied root configurations. Teeth were opened using a conventional bur and high speed drill. Imaging within the opened access cavity clarified the location of the roots where canal filing would initiate. Although radiographs are commonly used to determine the root canal size, position, and shape, the limited 2D image perspective leaves ambiguity that could be clarified if used in conjunction with a direct visual imaging tool. Direct visualization may avoid difficulties in locating the root canal and reduce the number of radiographs needed. A transillumination imaging device with the separated illumination and light collection functions rendered cracks visible in the prepared teeth that were otherwise indiscernible using reflected visible light. Our work demonstrates that a small diameter endoscope with high spatial resolution may significantly increase the efficiency and success of endodontic procedures.

  20. Fractional CO2 laser treatment for vaginal laxity: A preclinical study.

    Science.gov (United States)

    Kwon, Tae-Rin; Kim, Jong Hwan; Seok, Joon; Kim, Jae Min; Bak, Dong-Ho; Choi, Mi-Ji; Mun, Seok Kyun; Kim, Chan Woong; Ahn, Seungwon; Kim, Beom Joon

    2018-05-07

    Various studies have investigated treatment for vaginal laxity with microablative fractional carbon dioxide CO 2 laser in humans; however, this treatment has not yet been studied in an animal model. Herein, we evaluate the therapeutic effects of fractional CO 2 laser for tissue remodeling of vaginal mucosa using a porcine model, with the aim of improving vaginal laxity. The fractional CO 2 laser enables minimally invasive and non-incisional procedures. By precisely controlling the laser energy pulses, energy is sent to the vaginal canal and the introitus area to induce thermal denaturation and contraction of collagen. We examined the effects of fractional CO 2 laser on a porcine model via clinical observation and ultrasound measurement. Also, thermal lesions were histologically examined via hematoxylin-eosin staining, Masson's trichrome staining, and Elastica van Gieson staining and immunohistochemistry. The three treatment groups, which were determined according to the amount of laser-energy applied (60, 90, and 120 mJ), showed slight thermal denaturation in the vaginal mucosa, but no abnormal reactions, such as excessive hemorrhaging, vesicles, or erythema, were observed. Histologically, we also confirmed that the denatured lamina propria induced by fractional CO 2 laser was dose-dependently increased after laser treatment. The treatment groups also showed an increase in collagen and elastic fibers due to neocollagenesis and angiogenesis, and the vaginal walls became firmer and tighter because of increased capillary and vessel formation. Also, use of the fractional CO 2 laser increased HSP (heat shock protein) 70 and collagen type I synthesis. Our results show that microablative fractional CO 2 laser can produce remodeling of the vaginal connective tissue without causing damage to surrounding tissue, and the process of mucosa remodeling while under wound dressings enables collagen to increase and the vaginal wall to become thick and tightened. Lasers Surg. Med

  1. Semiclassical treatment of laser excitation of the hydrogen atom

    DEFF Research Database (Denmark)

    Billing, Gert D.; Henriksen, Niels Engholm; Leforestier, C.

    1992-01-01

    We present an alternative method for studying excitation of atoms in intense laser fields. In the present paper we focus upon the optical harmonic generation by hydrogen atoms.......We present an alternative method for studying excitation of atoms in intense laser fields. In the present paper we focus upon the optical harmonic generation by hydrogen atoms....

  2. Intracorporal Alexandrite-laser lithotripsy in the treatment of ureteral calculi

    Science.gov (United States)

    Zumbe, Juergen; Fischer, Hermann; Kimont, Hans-Georg; Kierfeld, Gerd

    1994-02-01

    Extracorporal shock wave lithotripsy (ESWL) is the standard therapy in the treatment of urinary calculi. the high rate of fragmentation and simultaneous stone selectivity makes laser lithotripsy an alternative method in the treatment of obstructing ureteral calculi. In comparison to the success rate of ESWL, laser lithotripsy as a minimally invasive endoscopic procedure seems to be superior in disintegrating calculi in the distal ureter. Together with the advance of miniaturized semiflexible endoscopes, intracorporal laser lithotripsy presents a new aspect in the treatment of urinary calculi.

  3. Comparative Study of Diode Laser Versus Neodymium-Yttrium Aluminum: Garnet Laser Versus Intense Pulsed Light for the Treatment of Hirsutism.

    Science.gov (United States)

    Puri, Neerja

    2015-01-01

    Lasers are widely used for the treatment of hirsutism. But the choice of the right laser for the right skin type is very important. Before starting with laser therapy, it is important to assess the skin type, the fluence, the pulse duration and the type of laser to be used. To compare the efficacy and side effects of Diode laser, Neodymium-yttrium aluminum - garnet (Nd: YAG) laser and intense pulsed light (IPL) on 30 female patients of hirsutism. Thirty female patients with hirsutism were selected for a randomised controlled study. The patients were divided into three groups of 10 patients each. In group I patients diode laser was used, in group II patients long pulsed Nd: YAG laser was used and in group III, IPL was used. The patients were evaluated and result graded according to a 4-point scale as excellent, >75% reduction; good, 50-75% reduction; fair; 25-50% reduction; and poor, diode laser group, followed by 35% hair reduction in the Nd: Yag laser group and 10% hair reduction in the IPL group. The percentage of hair reduction after four sessions of treatment was maximum (64%) in the diode laser group, followed by 62% hair reduction in the Nd: Yag laser group and 48% hair reduction in the IPL group. The percentage of hair reduction after eight sessions of treatment was maximum (92%) in the diode laser group, followed by 90% hair reduction in the Nd: YAG group and 70% hair reduction in the IPL group. To conclude for the Indian skin with dark hairs, the diode laser still stands the test of time. But, since the diode laser has a narrow margin of safety, proper pre and post-procedure cooling is recommended. Although, the side effects of Nd: YAG laser are less as compared to the diode laser, it is less efficacious as compared to the diode laser.

  4. A study of laser surface treatment in bonded repair of composite aircraft structures.

    Science.gov (United States)

    Li, Shaolong; Sun, Ting; Liu, Chang; Yang, Wenfeng; Tang, Qingru

    2018-03-01

    Surface pre-treatment is one of the key processes in bonded repair of aircraft carbon fibre reinforced polymer composites. This paper investigates the surface modification of physical and chemical properties by laser ablation and conventional polish treatment techniques. Surface morphology analysed by laser scanning confocal microscopy and scanning electron microscopy showed that a laser-treated surface displayed higher roughness than that of a polish-treated specimen. The laser-treated laminate exhibited more functional groups in the form of O 1 s/C 1 s atomic ratio of 30.89% for laser-treated and 20.14% for polish-treated as evidenced by X-ray photoelectron spectroscopy observation. Contact angle goniometry demonstrated that laser treatment can provide increased surface free energy and wettability. In the light of mechanical interlocking, molecular bonding and thermodynamics theories on adhesion, laser etching process displayed enhanced bonding performance relative to the polishing surface treatment. These properties resulted in an increased single lap shear strength and a cohesive failure mode for laser etching while an adhesive failure mode occurred in polish-treated specimen.

  5. LASIK flap breakthrough in Nd:YAG laser treatment of epithelial ingrowth

    NARCIS (Netherlands)

    Lapid-Gortzak, Ruth; Hughes, John M.; Nieuwendaal, Carla P.; Mourits, Maarten P.; van der Meulen, Ivanka J. E.

    2015-01-01

    To present two cases with complications after Nd:YAG laser treatment of epithelial ingrowth. Case reports. Dense central recurrent epithelial ingrowth was treated with a Nd:YAG laser directed at the epithelial nests in the LASIK flap interface in one case. Misalignment of the aiming beam after

  6. Ruby laser for treatment of tattoos: technical considerations affecting clinical use

    Science.gov (United States)

    Grove, Robert E.

    1990-06-01

    Recent clinical research on the use of ruby lasers for the treatment of tattoos and FIlk approval of a commercial system have renewed interest in this device. In this paper the principles of Q-switched ruby laser operation are reviewed, and potential sources of error in the estimation of delivered fluence are discussed.

  7. Pattern of intraocular pressure reduction following laser trabeculoplasty in open-angle glaucoma patients: comparison between selective and nonselective treatment

    Directory of Open Access Journals (Sweden)

    Almeida Jr ED

    2011-07-01

    Full Text Available Eglailson Dantas Almeida Júnior1, Luciano Moreira Pinto1,2, Rodrigo Antonio Brant Fernandes1,2, Tiago Santos Prata1,31Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil; 2Cerpo Oftalmologia, São Paulo, Brazil; 3Hospital Medicina dos Olhos, São Paulo, BrazilObjective: To compare the pattern of intraocular pressure (IOP reduction following selective laser trabeculoplasty (SLT versus argon laser trabeculoplasty (ALT in open-angle glaucoma (OAG patients, and to investigate the ability of initial IOP reduction to predict mid-term success.Methods: A prospective, nonrandomized, interventional case series was carried out. Consecutive uncontrolled OAG glaucoma patients underwent SLT or ALT; the same preoperative medical regimen was maintained during follow-up. Data collected included age, type of OAG, pre- and postoperative IOP, number of glaucoma medications, and surgical complications. Post-treatment assessments were scheduled at day 1 and 7 and months 1, 3, and 6.Results: A total of 45 patients (45 eyes were enrolled [SLT group (n = 25; ALT group (n = 20]. Groups were similar for age, baseline IOP, and number of glaucoma medications (P ≥ 0.12. We found no significant differences in mean IOP reduction between SLT (5.1 ± 2.5 mmHg; 26.6% and ALT (4.4 ± 2.8 mmHg; 22.8% groups at month 6 (P = 0.38. Success rates (IOP ≤ 16 mmHg and IOP reduction ≥25% at last follow-up visit were similar for SLT (72% and ALT (65% groups (P = 0.36. Comparing the pattern of IOP reduction (% of IOP reduction at each visit between groups, we found a greater effect following SLT compared with ALT at day 7 (23.7% ± 13.7% vs 8.1% ± 9.5%; P < 0.001. No significant differences were observed at other time points (P ≥ 0.32. Additionally, the percentage of IOP reduction at day 7 and at month 6 were significantly correlated in the SLT group (R2 = 0.36; P < 0.01, but not in the ALT group (P = 0.89. Early postoperative success predicted late

  8. Treatment of keloid scars with a 1210-nm diode laser in an animal model.

    Science.gov (United States)

    Philandrianos, Cécile; Bertrand, Baptiste; Andrac-Meyer, Lucile; Magalon, Guy; Casanova, Dominique; Kerfant, Nathalie; Mordon, Serge

    2015-12-01

    A temperature increase can improve wound healing by activation of heat shock protein 70 and stimulation of fibroblasts. Since keloids are a dysfunction of collagen fiber synthesis and organization, this study aimed to evaluate if a 1,210 nm diode laser could have effects in a new animal model of keloid scars. A total of 39 nude mice were used for this study. Phototypes IV and V human keloids were grafted into their backs and after 1 month of healing, the mice were divided into four groups: Control, Laser, Resection, Resection/Laser. In the Laser group, the keloids were treated with a 1,210-nm diode-laser with the following parameters: 4 W; 10 seconds; fluence: 51 J/cm(2) ; spot: 18.9 × 3.7 mm(2) . In the Resection group, surgical intra-lesional excision was performed. In the Resection/Laser group, keloids were treated with the 1,210-nm laser-diode after surgical intra-lesional excision. Temperature measurements were made during the laser treatment. Clinical examination and histological study were performed on the day of treatment and 1 month, 2 months, and 3 months later. Mean temperature measurement was of 44.8°C (42-48°) in the Laser groups. No healing complications or keloid proliferation was observed in any group. Keloid histologic characters were confirmed in all grafts. No histologic particularity was observed in the laser groups in comparison with the Control and Resection groups. First, this keloid animal model appears to be adapted for laser study. Secondly, the 1,210-nm diode laser does not induce keloid thermal damage in vivo. Further studies with different 1,210-nm laser diode parameters should be performed in order to observe significant effects on keloids. © 2015 Wiley Periodicals, Inc.

  9. Prospects for photosensitive dopants in liquid argon

    International Nuclear Information System (INIS)

    Anderson, D.F.

    1990-12-01

    Evidence is presented that the addition of a few ppM of a photosensitive dopant to a U/liquid argon or Pb/liquid argon calorimeter will make a substantial reduction in the e/π ratio. Previous results indicating high voltage problems and no change in the e/π ratio in tests of photosensitive dopants with the Fermilab D0 experiment's U/liquid argon tests calorimeter are also explained. 13 refs., 3 figs

  10. Laser Photoradiation Therapy For Neonatal Jaundice

    Science.gov (United States)

    Hamza, Mostafa; Hamza, Mohammad

    1987-04-01

    This paper describes our leading experience in the clinical application of laser in the treatment of neonatal jaundice. Currently, the irradiation of jaundiced infants during neonatal life to fluorescent light is the most common treatment of neonatal hyperbilirubinemia. The authors have investigated the photodegradation of bilirubin by laser in vitro and in Gunn rats before embarking on its clinical application in the treatment of jaundice in the new born child. This work was done to study the theraputic effect of laser compared to the currently used phototherapy in the treatment of neonatal jaundice. We selected 16 full term neonates with jaundice to be the subject of this study. The neonates of the study were devided into two groups. The first group was treated with continuous phototherapy . The second group recieved photoradiation therapy with gas laser The laser used was a CW argon-ion laser tuned to oscillate at 488.0 nm wavelength. This wavelength selection was based on our previous studies on the effect of laser irradiation of Gunn rats at different wavelengths. Comparison of the results of both methods of treatment will be reported in detail. The advantages and limitations of laser photoradiation therapy for neonatal jaundice will be discussed.

  11. The impact of treatment density and molecular weight for fractional laser-assisted drug delivery

    DEFF Research Database (Denmark)

    Haak, Christina S; Bhayana, Brijesh; Farinelli, William A

    2012-01-01

    Ablative fractional lasers (AFXL) facilitate uptake of topically applied drugs by creating narrow open micro-channels into the skin, but there is limited information on optimal laser settings for delivery of specific molecules. The objective of this study was to investigate the impact of laser...... treatment density (% of skin occupied by channels) and molecular weight (MW) for fractional CO(2) laser-assisted drug delivery. AFXL substantially increased intra- and transcutaneous delivery of polyethylene glycols (PEGs) in a MW range from 240 to 4300 Da (Nuclear Magnetic Resonance, p...

  12. Effect of Thermal Fields on the Structure of Corrosion-Resistant Steels Under Different Modes of Laser Treatment

    Science.gov (United States)

    Tarasova, T. V.; Gusarov, A. V.; Protasov, K. E.; Filatova, A. A.

    2017-11-01

    The influence of temperature fields on the structure and properties of corrosion-resistant chromium steels under different modes of laser treatment is investigated. A model of heat transfer under laser impact on target is used to plot thermal fields and cycles and cooling rates. It is shown that the model used for computing thermal fields gives tentative geometric sizes of the fusion zones under laser treatment and selective laser fusion. The cooling rate is shown to have decisive influence on the structure of corrosion-resistant steels after laser treatment with surface fusion in devices for pulsed, continuous, and selective laser melting.

  13. Comparison of pulsed dye laser versus combined pulsed dye laser and Nd:YAG laser in the treatment of inflammatory acne vulgaris.

    Science.gov (United States)

    Salah El Din, Manal Mohamed; Samy, Nevien Ahmed; Salem, Amira Eid

    2017-06-01

    Both pulsed dye laser and combined 585/1064-nm (sequential dual-wavelength PDL and Nd:YAG) laser improves inflammatory skin disorders including acne vulgaris. To compare the efficacy of 585-nm pulsed dye laser versus sequential dual-wavelength PDL and Nd:YAG in treatment of acne vulgaris. Thirty patients with acne vulgaris were treated by PDL alone on half of the face while contra lateral half was treated by combined 585/1064 nm laser. The study showed that inflammatory acne lesions count was significantly reduced by 82.5% (p 0.0001) on PDL sides and by 83.5% (p 0.00001) on combined 585/1064-nm side after 8 weeks, while reduction of non-inflammatory acne lesions was observed at 8 weeks by 58.4% and 71.5% respectively. However, difference between the two modalities was not statistically significant. PDL and combined PDL/Nd:YAG laser treatment were found to be an effective, safe and well-tolerated treatment option for inflammatory and non-inflammatory acne vulgaris.

  14. Thoracoscopic CO laser coagulation shrinkage of blebs in treatment of spontaneous pneumothorax

    Science.gov (United States)

    Sensaki, Koji; Arai, Tsunenori; Kikuchi, Keiichi; Takagi, Keigo; Tanaka, Susumu; Kikuchi, Makoto

    1992-06-01

    Spontaneous pneumothorax is a common disease in young people. Operative intervention has been done in most of the recurrent cases. Recently thoracoscopic treatment has been tested as a less invasive treatment modarity. We adopted carbon monoxide (CO) laser for thoracoscopic treatment of recurrent spontaneous pneumothorax. CO laser (wavelength; 5.4 micrometers ) could be delivered by chalcogenide glass (As - S) covered with a teflon sheath and ZnSe fiber tip. The sterilized flexible bronchoscope was inserted through the thoracoscopic outer sheath under local anesthesia. Shrinkage of blebs was obtained by non-contact method of CO laser irradiation. Laser power at the tip was 2.5 - 5 W and irradiation duration was 0.5 s each. Excellent shrinkage of bleb and bulla could be obtained by CO laser without perforation complication. Advantages of CO laser as a thoracoscopic treatment were: (1) capability of fiber delivery (flexible thoracoscopy was easy to operate and clear to visualize the blebs which were frequently found at the apical portion of the lung, and (2) shallow extinction length (good shrinkage of blebs, low risk of perforation, and thin layer of carbonization). In conclusion, our new technique of thoracoscopic CO laser irradiation was found to be a safe and effective treatment of spontaneous pneumothorax.

  15. Treatment of dilated pores with 1410-nm fractional erbium-doped fiber laser.

    Science.gov (United States)

    Suh, Dong-Hye; Chang, Ka-Yeun; Lee, Sang-Jun; Song, Kye-Yong; Choi, Jeong Hwee; Shin, Min Kyung; Jeong, Ki-Heon

    2015-04-01

    Dilated pores can be an early sign of skin aging and are a significant cosmetic concern. The 1410-nm wavelength is optimal for superficial dermal treatments up to 650 μm deep. The aim of the present study was to evaluate the clinical effectiveness and safety of the fractional erbium-doped fiber 1410-nm laser in the treatment of dilated pores. Fifteen patients with dilated facial pores underwent three laser treatments at 3-week intervals. Posttreatment skin responses and side effects were assessed at treatment and follow-up visits by study physicians. Clinical effectiveness of treatment was assessed by both study physicians and patients 3 months after the final laser treatment using a quartile grading scale. Histological examination was performed using biopsy samples taken at baseline (pretreatment) and 3 months after the last treatment. This study showed that greater than 51 % improvement in dilated pores was demonstrated in 14 of 15 patients after three sessions of laser treatments. Improvements in skin texture, tone, and smoothness were reported in all patients. Treatment was well tolerated in all patients, with no unanticipated side effects. This study demonstrates that the 1410-nm fractional erbium fiber laser is effective and safe for treatment of dilated facial pores in Fitzpatrick skin types III-IV.

  16. Laser treatment of dental ceramic/cement layers: transmitted energy, temperature effects and surface characterisation.

    Science.gov (United States)

    Pich, Olena; Franzen, René; Gutknecht, Norbert; Wolfart, Stefan

    2015-02-01

    In the present paper, we investigate the behaviour of different dental materials under laser irradiation. We have used e.max Ceram, e.max ZirCAD, and e.max Press dental ceramics and glass ionomer cement Ketac Cem in the present study. The dental ceramics were prepared in the form of samples with thickness of 0.5-2 mm. We used two lasers [solid-state laser (Er:YAG, Fidelis III+, Fotona) and an 810- nm diode laser (FOX, A.R.C)] for the transillumination of ceramic samples. It has been shown that the laser energy transmitted through the ceramic material decreases to 30-40% of the original values along with an increase in the thickness of the irradiated sample. Pigmented ceramic samples show more laser energy loss compared to the samples containing no pigment. We investigated the temperature evolution in composite sandwiched ceramic/cement samples under laser treatment. The increase in the irradiation time and laser power led to a temperature increase of up to 80 °C. The surfaces of irradiated ceramic samples were examined with X-ray photoelectron spectroscopy to evaluate changes in chemical composition, such as a decrease in the C signal, accompanied by a strong increase in the Zr peak for the Er:YAG laser, while the 810-nm diode laser showed no change in the ratio of elements on the surface.

  17. Spectroscopic characterization of post-cluster argon plasmas during the blast wave expansion

    International Nuclear Information System (INIS)

    Chung, H.-K.; Fournier, K.B.; Edwards, M.J.; Scott, H.A.; Lee, R.W.; Cattolica, R.; Ditmire, T.

    2002-01-01

    In this work we present temperature diagnostics of an expanding laser-produced argon plasma. A short-pulse (35fs) laser with an intensity of I = 1017 W/cm deposits ∼ 100 mJ of energy into argon clusters. This generates a hot plasma filament that develops into a cylindrically expanding shock. We develop spectral diagnostics for the temperatures of the argon plasma in the shock region and the preionized region ahead of the shock. A collisional-radiative model is applied to explore line intensity ratios derived from Ar II-Ar IV spectra that are sensitive to temperatures in a few eV range. The results of hydrodynamic simulations are employed to derive a time dependent radiative transport calculation that generates the theoretical emission spectra from the expanding plasma

  18. Spectroscopic Characterization of Post-Cluster Argon Plasmas During the Blast Wave Expansion

    International Nuclear Information System (INIS)

    Ching, H-K.; Fournier, K.B.; Edwards, M.J.; Scott, H.A.; Cattolica, R.; Ditmire, T.; Lee, R.W.

    2002-01-01

    In this work we present temperature diagnostics of an expanding laser-produced argon plasma. A short-pulse (35fs) laser with an intensity of I = 10 17 W/cm 2 deposits ∼ 100 mJ of energy into argon clusters. This generates a hot plasma filament that develops into a cylindrically expanding shock. We develop spectral diagnostics for the temperatures of the argon plasma in the shock region and the preionized region ahead of the shock. A collisional-radiative model is applied to explore line intensity ratios derived from Ar II - Ar IV spectra that are sensitive to temperatures in a few eV range. The results of hydrodynamic simulations are employed to derive a time dependent radiative transport calculation that generates the theoretical emission spectra from the expanding plasma

  19. Holmium laser use in the treatment of selected dry eye syndrome complications

    Science.gov (United States)

    Kecik, Dariusz; Kecik, Tadeusz; Kasprzak, Jan; Kecik, Mariusz

    1996-03-01

    The authors present initial results of treatment selected complications of dry eye syndrome with holmium laser. The lacrimal puncta obliteration and coagulation of the corneal ulcer surface were done.

  20. Output of CT images and treatment planning data to a laser printer

    International Nuclear Information System (INIS)

    Kleinschmidt, C.; Gfirtner, H.; Goetzfried, M.

    1992-01-01

    We introduce a program for the digital output of CT images with overlaid isodose maps to a laser printer. The high quality prints permit the additional output of treatment planning data on the same sheet. (orig.) [de

  1. Oral Dextrose for Pain Management during Laser Treatment of Retinopathy of Prematurity under Topical Anesthesia.

    Science.gov (United States)

    Kataria, Manisha; Narang, Subina; Chawla, Deepak; Sood, Sunandan; Gupta, Parul Chawla

    2015-08-01

    To evaluate efficacy of oral dextrose, in addition to topical anesthesia in providing pain relief during laser ablation therapy of retinopathy of prematurity (ROP). In this randomized controlled trial, neonates with type 1 ROP undergoing laser ablation of peripheral retina were randomized to receive or not to receive 2 ml of 25 % dextrose orally just before the laser therapy. In both the groups, topical anesthesia was provided by instilling paracaine eye drops twice at 10 min interval just before the laser treatment. Main outcome was Premature Infant Pain Profile (PIPP) recorded before and 30 s after starting the laser treatment. Birth weight, gestation, stage and extent of ROP and other baseline variables were comparable among neonates randomized to dextrose (n = 12) or control (n = 12) groups. Both groups required comparable number of laser spots. PIPP scores was comparable in neonates randomized to dextrose or control groups and indicated significant amount of pain felt during laser ablation despite local anesthesia with or without oral dextrose. Single dose of oral dextrose did not significantly reduce pain during laser treatment in premature neonates. Further studies with multiple doses of dextrose and its combination with other non-pharmacological (e.g., behavioral, physical) interventions may be needed.

  2. Time resolved laser induced fluorescence on argon intermediate pressure microwave discharges : measuring the depopulation rates of the 4p and 5p excited levels as induced by electron and atom collisions

    NARCIS (Netherlands)

    Palomares Linares, J.M.; Graef, W.A.A.D.; Hubner, S.; Mullen, van der J.J.A.M.

    2013-01-01

    The reaction kinetics in the excitation space of Ar is explored by means of Laser Induced Fluorescence (LIF) experiments using the combination of high rep-rate YAG–Dye laser systems with a well defined and easily controllable surfatron induced plasma setup. The high rep-rate favors the photon

  3. Picosecond Laser Treatment for Tattoos and Benign Cutaneous Pigmented Lesions (Secondary publication).

    Science.gov (United States)

    Kasai, Kenichiro

    2017-12-31

    The selective removal of tattoos and benign cutaneous pigmented lesions with laser energy evolved rapidly with the development of the nanosecond-domain Q-switched laser (ns-laser). Recently, however, a series of picosecond-domain lasers (ps-lasers) with pulsewidths less than 1 ns has become commercially available, enabling more efficient and faster removal of pigmented lesions in the field of dermatologic laser surgery. The efficacy of the ns-laser depended on the theory of selective photothermolysis, whereby an extremely short pulse width was delivered less than the thermal relaxation time (TRT) of a target. At sub-ns pulsewidths, i.e. in the ps-domain, this efficacy is dramatically extended through defeating the stress relaxation time (SRT) of a target allowing for even more effective pigment destruction with even less damage to the surrounding normal tissue. This will be discussed in detail. The ps-laser has been reported as achieving tattoo removal in fewer sessions than the ns-laser, with less in the way of unwanted side effects. Tattoos recalcitrant to ns-laser treatment have responded well to the ps-laser, and although true 'color blindness' is not yet completely achieved with the ps-domain pulses currently available, multicolored tattoos have also responded very favorably. The ability to limit damage precisely to the pigment target gives greater efficacy in treatment of epidermal lesions with less induction of post-inflammatory hyperpigmentation in the PIH-susceptible Asian skin, and dermal melanocytosis also respond very well to ps-laser treatment. Illustrative clinical examples from the author's experience are given. Current ps-lasers could be a revolutionary advance for laser tattoo removal but may be less effective for some specific aesthetic indications such as melasma and other cosmetic procedures. Manufacturers must make an effort to reduce the current comparatively long ps-domain pulsewidths to deliver a 'true' ps-domain laser, with more basic

  4. Treatment of Large Bulla Formation after Tattoo Removal with a Q-Switched Laser

    Science.gov (United States)

    Kartono, Francisca; Desai, Alpesh; Kaur, Ravneet R.; Desai, Tejas

    2010-01-01

    Widely considered the gold standard treatment option for tattoo removal, the use of Q-switched lasers may very rarely result in the formation of large bulla. While very disconcerting to patients, these lesions are easily managed and, with proper care, heal quickly with no long-term consequences. The authors present three cases of patients who had bullous reactions shortly after receiving Q-switched laser treatment of tattoo ink. Bullous formation in all three patients was treated successfully. PMID:20725537

  5. Two-micron (Thulium) Laser Prostatectomy: An Effective Method for BPH Treatment.

    Science.gov (United States)

    Jiang, Qi; Xia, Shujie

    2014-01-01

    The two-micron (thulium) laser is the newest laser technique for treatment of bladder outlet obstruction resulting from benign prostatic hyperplasia (BPH). It takes less operative time than standard techniques, provides clear vision and lower blood loss as well as shorter catheterization times and hospitalization times. It has been identified to be a safe and efficient method for BPH treatment regardless of the prostate size.

  6. Continuum radiation of argon plasma

    International Nuclear Information System (INIS)

    D'Yachkov, L.G.

    1995-01-01

    A simple completely analytical method of the calculation of radiative continuum of plasmas is derived and an analysis of experimental data on continuum radiation of argon plasma is made. The method is based on the semiclassical quantum defect theory. To calculate radial matrix elements of dipole transitions the asymptotic expansion in powers of E c /ω 2/3 , with an accuracy to the linear term, where E, is the arithmetic mean of the initial and final energies of the transition, is used. This expansion has the same form for free-free, free-bound and bound-bound transitions. If the quantum defects are also approximated by a linear function of energy, the integration over the electron energy (the Maxwell-Boltzmann distribution is assumed) can be performed in analytical form. For Rydberg states the sum of photoionization continua can be replaced by an integral. We have calculated the absorption coefficient pf argon plasma. The photoionization cross section is calculated for all the states of 4s, 5s, 6s, 4p, 5p, 3d, 4d, 4s', 5s', 6s', 4p', 5p', 3d' and 4d' configurations taking into account P-coupling and multiplet splitting (56 states). Other excited states are allowed for by the integral formula together with free-free transitions

  7. Treatment of alopecia areata with the 308-nm xenon chloride excimer laser: case report of two successful treatments with the excimer laser.

    Science.gov (United States)

    Gundogan, Cuneyt; Greve, Bärbel; Raulin, Christian

    2004-01-01

    Alopecia areata is a common disease of unknown etiology; it causes significant cosmetic and psycho-social distress for most of the people it affects. We report on an innovative form of treatment in two patients with typical alopecia areata on the capillitium. We successfully treated two patients whose alopecia areata had worsened progressively for 3 and 14 weeks. The treatment involved the use of a 308 nm xenon chloride excimer laser (dosage 300-2,300 mJ/cm(2) per session). After 11 and 12 sessions within a 9-week and 11-week period, the entire affected focus showed homogenous and thick regrowth. No relapse was observed during the follow-up period of 5 and 18 months. The use of the excimer laser is an effective, elegant, and safe means of treatment and has good tolerability. Analogous to topical treatment of alopecia areata, the immunosuppressive mechanism of the excimer laser can be interpreted as an induction of T-cell apoptosis. This new means of treatment has yet to be discussed in medical literature. Further studies with greater numbers are needed to assess its potential more precisely and evaluate the excimer laser in treating alopecia areata. Copyright 2004 Wiley-Liss, Inc.

  8. Enhanced graphitization of c-CVD grown multi-wall carbon nanotube arrays assisted by removal of encapsulated iron-based phases under thermal treatment in argon

    International Nuclear Information System (INIS)

    Boncel, Slawomir; Koziol, Krzysztof K.K.

    2014-01-01

    Graphical abstract: - Highlights: • Annealing of the c-CVD MWCNT arrays toward complete removal of iron nanoparticles. • The ICP-AES protocol established for quantitative analysis of Fe-content in MWCNTs. • The vertical alignment from the as-grown MWCNT arrays found intact after annealing. • A route to decrease number of defects/imperfections in the MWCNT graphene walls. • A foundation for commercial purification of c-CVD derived MWCNTs. - Abstract: The effect of annealing on multi-walled carbon nanotube (MWCNT) arrays grown via catalytic Chemical Vapour Deposition (c-CVD) was studied. The treatment enabled to decrease number of defects/imperfections in the graphene walls of MWCNTs’, which was reflected in Raman spectroscopy by reduction of the I D /I G ratio by 27%. Moreover, the vertical alignment from the as-synthesized nanotube arrays was found intact after annealing. Not only graphitization of the nanotube walls occurred under annealing, but the amount of metal iron-based catalyst residues (interfering with numerous physicochemical properties, and hence applications of MWCNTs) was reduced from 9.00 wt.% (for pristine MWCNTs) to 0.02 wt.% as detected by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). This value, established by a new analytical protocol, is the lowest recorded by now for purified c-CVD MWCNTs and, due to operating under atmospheric pressure, medium temperature regime (as for annealing processes), reasonable time-scale and metal residue non-specificity, it could lay the foundation for commercial purification of c-CVD derived MWCNTs

  9. Enhanced graphitization of c-CVD grown multi-wall carbon nanotube arrays assisted by removal of encapsulated iron-based phases under thermal treatment in argon

    Energy Technology Data Exchange (ETDEWEB)

    Boncel, Slawomir, E-mail: slawomir.boncel@polsl.pl [Department of Organic Chemistry, Biochemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, 44-100 Gliwice (Poland); Koziol, Krzysztof K.K., E-mail: kk292@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, CB3 0FS Cambridge (United Kingdom)

    2014-05-01

    Graphical abstract: - Highlights: • Annealing of the c-CVD MWCNT arrays toward complete removal of iron nanoparticles. • The ICP-AES protocol established for quantitative analysis of Fe-content in MWCNTs. • The vertical alignment from the as-grown MWCNT arrays found intact after annealing. • A route to decrease number of defects/imperfections in the MWCNT graphene walls. • A foundation for commercial purification of c-CVD derived MWCNTs. - Abstract: The effect of annealing on multi-walled carbon nanotube (MWCNT) arrays grown via catalytic Chemical Vapour Deposition (c-CVD) was studied. The treatment enabled to decrease number of defects/imperfections in the graphene walls of MWCNTs’, which was reflected in Raman spectroscopy by reduction of the I{sub D}/I{sub G} ratio by 27%. Moreover, the vertical alignment from the as-synthesized nanotube arrays was found intact after annealing. Not only graphitization of the nanotube walls occurred under annealing, but the amount of metal iron-based catalyst residues (interfering with numerous physicochemical properties, and hence applications of MWCNTs) was reduced from 9.00 wt.% (for pristine MWCNTs) to 0.02 wt.% as detected by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). This value, established by a new analytical protocol, is the lowest recorded by now for purified c-CVD MWCNTs and, due to operating under atmospheric pressure, medium temperature regime (as for annealing processes), reasonable time-scale and metal residue non-specificity, it could lay the foundation for commercial purification of c-CVD derived MWCNTs.

  10. Real efficiency of ambulatory laser treatment at the patients with different rheumatic diseases

    Science.gov (United States)

    Sidenco, Elena-Luminita; Ristache, Sanda; Belu, Luminita

    2001-06-01

    We consulted 189 patients, with different locomotory diseases: degenerative, posttraumatic and chronic inflammatory rheumatic diseases. We followed the main clinical parameters: pain, limitation of mobility, affected function, inflammation and disorders of sensitivity. We applied an infrared LASER source of 100 mW (BTL), daily, for 5 days. The tolerance of the patients at the LASER treatment was excellent (100%). The evolution of the clinical parameters was variated, but inflammation, limitation of mobility and the affected function significantly improved (30-50%). We found a significant diminution of pain (27- 39%). We believe the LASER treatment in ambulatory conditions is essential for the function of the patients with different locomotory diseases.

  11. BET 2: LASER THERAPY IN THE TREATMENT OF ACUTE HAMSTRING MUSCLE INJURIES.

    Science.gov (United States)

    Hughes, Tom; Callaghan, Michael

    2017-04-01

    Local laser therapy has been suggested as a promising treatment for acute hamstring muscle tears. We carried out a shortcut systematic review to establish whether therapeutic lasers are beneficial for patients with acute hamstring tears. Despite a comprehensive literature search, no studies that were directly relevant to the question could be identified. The clinical bottom line is therefore that there is currently no evidence for the use of any form of laser therapy in the treatment of acute hamstring muscle tears. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Low-power laser use in the treatment of alopecia and crural ulcers

    Science.gov (United States)

    Ciuchita, Tavi; Usurelu, Mircea; Antipa, Ciprian; Vlaiculescu, Mihaela; Ionescu, Elena

    1998-07-01

    The authors tried to verify the efficacy of Low Power Laser (LPL) in scalp alopecia and crural ulcers of different causes. Laser used was (red diode, continuous emission, 8 mW power, wave length 670 nm spot size about 5 mm diameter on some points 1 - 2 minutes per point. We also use as control classical therapy. Before, during and after treatment, histological samples were done for alopecia. For laser groups (alopecia and ulcers) the results were rather superior and in a three or twice time shorter than control group. We conclude that LPL therapy is a very useful complementary method for the treatment of scalp alopecia and crural ulcers.

  13. Combination laser treatment for immediate post-surgical scars: a retrospective analysis of 33 immature scars.

    Science.gov (United States)

    Lee, Yongsoo; Kim, Wooram

    2017-07-01

    The application of laser treatments beginning on the day of stitch removal has been demonstrated to improve scar quality. However, there are few guidelines for the treatment of immature scars (ISs), which are defined as "scars whose features are not yet expressed." The purpose of this study was to extract information about early combination laser treatment (CLT) beyond what is currently known by analyzing 33 pairs of pre-treatment and post-treatment photographs of ISs. Two hundred fifty medical records of patients with scars were reviewed, and 33 scars were included in the study. The included scars were treated with vascular lasers (585 or 532 nm) followed by 1550-nm fractional lasers from May 2014 to July 2015 (fewer than 52 days after stitch removal, Fitzpatrick's skin types III-IV, mean age = 16.0 years). Blinded evaluators (one plastic surgeon and two dermatologists) evaluated the pre-treatment and post-treatment photographs. The pre-treatment photographs were scored on a spectrum from "0," when no difference with the surrounding unaffected skin was observed, to "100," when the worst scarring was present. The pre-treatment and post-treatment photographs were compared, and the results were graded on a spectrum from 0, when no difference between the pre-treatment and post-treatment photographs was observed, to 100, when no difference was observed between the post-treatment skin and the surrounding unaffected skin. Statistical analyses were performed with PASW 17.0, SPSS Korea, Seoul, Korea (p laser groups. Patient age and Wtd score were negatively correlated, and a significant difference was observed in the Wtd scores between the age groups (≥15 and lasers are equally effective for CLT of ISs.

  14. Er:YAG Laser Dental Treatment of Patients Affected by Epidermolysis Bullosa

    Directory of Open Access Journals (Sweden)

    Angela Galeotti

    2014-01-01

    Full Text Available Aim. The purpose of this study was to evaluate the efficacy of Er:YAG laser used for treating hard dental tissue in patients with epidermolysis bullosa (EB. Methods. We report two cases of EB in which an Er:YAG laser was used for conservative treatments. In the first case, the Er:YAG laser (2,940 μm, 265 mJ, 25 Hz was used to treat caries on a deciduous maxillary canine in an 8-year-old male patient affected by dystrophic EB. In the second case, we treated a 26-year-old female patient, affected by junctional EB, with generalized enamel hypoplasia, and an Er:YAG laser (2,940 μm, 265 mJ, 25 Hz was used to remove the damaged enamel on maxillary incisors. Results. The use of the Er:YAG laser, with the appropriate energy, was effective in the selective removal of carious tissue and enamel hypoplasia. During dental treatment with the Er:YAG laser, patients required only a few interruptions due to the absence of pain, vibration, and noise. Conclusions. Laser treatment of hard dental tissues is a valuable choice for patients affected by EB since it is less invasive compared to conventional treatment, resulting in improved patient compliance.

  15. Management of Liver Cancer Argon-helium Knife Therapy with Functional Computer Tomography Perfusion Imaging.

    Science.gov (United States)

    Wang, Hongbo; Shu, Shengjie; Li, Jinping; Jiang, Huijie

    2016-02-01

    The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy. © The Author(s) 2014.

  16. Comparison of diode laser and Er:YAG lasers in the treatment of ankyloglossia.

    Science.gov (United States)

    Aras, Mutan Hamdi; Göregen, Mustafa; Güngörmüş, Metin; Akgül, Hayati Murat

    2010-04-01

    The purpose of this study was to compare the tolerance of lingual frenectomy with regard to a local anesthesia requirement and comparison of postsurgical discomfort experienced by patients operated on with both diode and erbium:yttrium-aluminium-garnet (Er:YAG) lasers. Ankyloglossia, commonly known as tongue-tie, is a congenital oral anomaly characterized by a short lingual frenulum. A short lingual frenulum may contribute to feeding, speech, and mechanical tongue problems. Sixteen referred patients with tongue mobility complaints were included in this study. A GaAlAs laser device with a continuous wavelength of 808 nm was used in the diode group. Frenulums were incised by applying 2 W of laser power. The Er:YAG laser device with a continuous wavelength of 2940 nm was used in the Er:YAG group. Frenulums were incised by applying 1 W of laser power. The acceptability of the lingual frenectomy without local anesthesia and the degree of the postsurgical discomfort were evaluated. Although the majority of patients (six) could be operated on without local anesthesia in the Er:YAG group, all patients could not be operated on without local anesthetic agent in the diode group. There were no differences between the two groups with regard to pain, chewing, and speaking on the first or seventh day after surgery, whereas patients had more pain in the Er:YAG group than in the diode group the first 3 h after surgery. The results indicate that only the Er:YAG laser can be used for lingual frenectomy without local anesthesia, and there was no difference between the two groups regarding the degree of the postsurgical discomfort except in the first 3 h. In conclusion, these results indicate that the Er:YAG laser is more advantageous than the diode laser in minor soft-tissue surgery because it can be performed without local anesthesia and with only topical anesthesia.

  17. Fractional CO 2 laser resurfacing as monotherapy in the treatment of atrophic facial acne scars

    Directory of Open Access Journals (Sweden)

    Imran Majid

    2014-01-01

    Full Text Available Background: While laser resurfacing remains the most effective treatment option for atrophic acne scars, the high incidence of post-treatment adverse effects limits its use. Fractional laser photothermolysis attempts to overcome these limitations of laser resurfacing by creating microscopic zones of injury to the dermis with skip areas in between. Aim: The aim of the present study is to assess the efficacy and safety of fractional CO 2 laser resurfacing in atrophic facial acne scars. Materials and Methods: Sixty patients with moderate to severe atrophic facial acne scars were treated with 3-4 sessions of fractional CO 2 laser resurfacing at 6-week intervals. The therapeutic response to treatment was assessed at each follow up visit and then finally 6 months after the last laser session using a quartile grading scale. Response to treatment was labelled as ′excellent′ if there was >50% improvement in scar appearance and texture of skin on the grading scale while 25-50% response and <25% improvement were labelled as ′good′ and ′poor′ response, respectively. The overall satisfaction of the patients and any adverse reactions to the treatment were also noted. Results: Most of the patients showed a combination of different morphological types of acne scars. At the time of final assessment 6 months after the last laser session, an excellent response was observed in 26 patients (43.3% while 15 (25% and 19 patients (31.7% demonstrated a good and poor response respectively. Rolling and superficial boxcar scars responded the best while pitted scars responded the least to fractional laser monotherapy. The commonest reported adverse effect was transient erythema and crusting lasting for an average of 3-4 and 4-6 days, respectively while three patients developed post-inflammatory pigmentation lasting for 8-12 weeks. Conclusions: Fractional laser resurfacing as monotherapy is effective in treating acne scars especially rolling and superficial boxcar

  18. Polydiagnostic calibration performed on a low pressure surface wave sustained argon plasma

    NARCIS (Netherlands)

    Vries, de N.; Palomares, J.M.; Iordanova, E.I.; Veldhuizen, van E.M.; Mullen, van der J.J.A.M.

    2008-01-01

    The electron density and electron temperature of a low pressure surface wave sustained argon plasma have been determined using passive and active (laser) spectroscopic methods simultaneously. In this way the validity of the various techniques is established while the plasma properties are determined

  19. Feasibility of LED-Assisted CMOS Camera: Contrast Estimation for Laser Tattoo Treatment

    Directory of Open Access Journals (Sweden)

    Ngot Thi Pham

    2018-04-01

    Full Text Available Understanding the residual tattoo ink in skin after laser treatment is often critical for achieving good clinical outcomes. The current study aims to investigate the feasibility of a light-emitting diode (LED-assisted CMOS camera to estimate the relative variations in tattoo contrast after the laser treatment. Asian mice were tattooed using two color inks (black and red. The LED illumination was a separate process from the laser tattoo treatment. Images of the ink tattoos in skin were acquired under the irradiation of three different LED colors (red, green, and blue for pre- and post-treatment. The degree of contrast variation due to the treatment was calculated and compared with the residual tattoo distribution in the skin. The black tattoo demonstrated that the contrast consistently decreased after the laser treatment for all LED colors. However, the red tattoo showed that the red LED yielded an insignificant contrast whereas the green and blue LEDs induced a 30% (p < 0.001 and 26% (p < 0.01 contrast reduction between the treatment conditions, respectively. The proposed LED-assisted CMOS camera can estimate the relative variations in the image contrast before and after the laser tattoo treatment.

  20. Liquid argon calorimetry for the SSC

    International Nuclear Information System (INIS)

    Gordon, H.A.

    1990-01-01

    Liquid argon calorimetry is a mature technique. However, adapting it to the challenging environment of the SSC requires a large amount of R ampersand D. The advantages of the liquid argon approach are summarized and the issues being addressed by the R ampersand D program are described. 18 refs

  1. Efficacy of low level laser therapy in the treatment of burning mouth syndrome: A systematic review.

    Science.gov (United States)

    Al-Maweri, Sadeq Ali; Javed, Fawad; Kalakonda, Butchibabu; AlAizari, Nader A; Al-Soneidar, Walid; Al-Akwa, Ameen

    2017-03-01

    Burning mouth syndrome (BMS) is a chronic pain condition with indefinite cure, predominantly affecting post-menopausal women. The aim of this study was to systematically review the efficacy of low level laser therapy in the treatment of burning mouth syndrome (BMS). PubMed, Embase and Scopus were searched from date of inception till and including October 2016 using various combinations of the following keywords: burning mouth syndrome, BMS, stomatodynia, laser therapy, laser treatment and phototherapy. The inclusion criteria were: Prospective, retrospective and case series studies. Letter to editors, reviews, experimental studies, studies that were not published in English, theses, monographs, and abstracts presented in scientific events were excluded. Due to heterogeneity of data no statistical analyses were performed. Ten clinical studies fulfilled the eligibility criteria, five of which were randomized clinical trials. In these studies, the laser wavelengths, power output and duration of irradiation ranged between 630-980nm, 20-300mW, 10s-15min, respectively. Most of studies reported laser to be an effective therapy strategy for management of BMS. Majority of the studies showed that laser therapy seemed to be effective in reducing pain in BMS patients. However, due to the varied methodologies and substantial variations in laser parameters among these studies, more clinical trials are required to ascertain the efficacy of laser for treating BMS. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. The application of diode laser in the treatment of oral soft tissues lesions. A literature review.

    Science.gov (United States)

    Ortega-Concepción, Daniel; Cano-Durán, Jorge A; Peña-Cardelles, Juan-Francisco; Paredes-Rodríguez, Víctor-Manuel; González-Serrano, José; López-Quiles, Juan

    2017-07-01

    Since its appearance in the dental area, the laser has become a treatment of choice in the removal of lesions in the oral soft tissues, due to the numerous advantages they offer, being one of the most used currently the diode laser. The aim of this review was to determine the efficacy and predictability of diode laser as a treatment of soft tissue injuries compared to other surgical methods. A literature review of articles published in PubMed/MEDLINE, Scopus and the Cochrane Library databases between 2007 and 2017 was performed. "Diode laser", "soft tissue", "oral cavity" and "oral surgery" were employed for the search strategy. Only articles published English or Spanish were selected. The diode laser is a minimally invasive technology that offers great advantages, superior to those of the conventional scalpel, such as reduction of bleeding, inflammation and the lower probability of scars. Its effectiveness is comparable to that of other types of lasers, in addition to being an option of lower cost and greater ease of use. Its application in the soft tissues has been evaluated, being a safe and effective method for the excision of lesions like fibromas, epulis fissuratum and the accomplishment of frenectomies. The diode laser can be used with very good results for the removal of lesions in soft tissues, being used in small exophytic lesions due to their easy application, adequate coagulation, no need to suture and the slightest inflammation and pain. Key words: Diode laser, soft tissues, oral cavity, oral surgery.

  3. Inflammatory responses, matrix remodeling, and re-epithelialization after fractional CO2 laser treatment of scars.

    Science.gov (United States)

    DeBruler, Danielle M; Blackstone, Britani N; Baumann, Molly E; McFarland, Kevin L; Wulff, Brian C; Wilgus, Traci A; Bailey, J Kevin; Supp, Dorothy M; Powell, Heather M

    2017-09-01

    Fractional CO 2 laser therapy has been used to improve scar pliability and appearance; however, a variety of treatment protocols have been utilized with varied outcomes. Understanding the relationship between laser power and extent of initial tissue ablation and time frame for remodeling could help determine an optimum power and frequency for laser treatment. The characteristics of initial injury caused by fractional CO 2 laser treatment, the rates of dermal remodeling and re-epithelialization, and the extent of inflammation as a function of laser stacking were assessed in this study in a porcine scar model. Full-thickness burn wounds were created on female Red Duroc pigs followed by immediate excision of the eschar and split-thickness autografting. Three months after injury, the resultant scars were treated with a fractional CO 2 laser with 70 mJ of energy delivered as either a single pulse or stacked for three consecutive pulses. Immediately prior to laser treatment and at 1, 24, 96, and 168 hours post-laser treatment, transepidermal water loss (TEWL), erythema, and microscopic characteristics of laser injury were measured. In addition, markers for inflammatory cytokines, extracellular matrix proteins, and re-epithelialization were quantified at all time points using qRT-PCR. Both treatments produced erythema in the scar that peaked 24 hours after treatment then decreased to basal levels by 168 hours. TEWL increased after laser treatment and returned to normal levels between 24 and 96 hours later. Stacking of the pulses did not significantly increase the depth of ablated wells or extend the presence of erythema. Interleukin 6 and monocyte chemoattractant protein-1 were found to increase significantly 1 hour after treatment but returned to baseline by 24 hours post laser. In contrast, expression of transforming growth factor β1 and transforming growth factor β3 increased slowly after treatment with a more modest increase than interleukin 6 and monocyte

  4. Different lasers in the treatment of benign prostatic hyperplasia: a network meta-analysis

    Science.gov (United States)

    Zhang, Xingming; Shen, Pengfei; He, Qiying; Yin, Xiaoxue; Chen, Zhibin; Gui, Haojun; Shu, Kunpeng; Tang, Qidun; Yang, Yaojing; Pan, Xiuyi; Wang, Jia; Chen, Ni; Zeng, Hao

    2016-01-01

    All available surgical treatments for benign prostatic hyperplasia (BPH) have their individual advantages or disadvantages. However, the lack of head-to-head studies comparing different surgeries makes it unavailable to conduct direct analysis. To compare the efficacy and safety among different lasers and transurethral resection of prostate (TURP) for BPH, randomized controlled trials were searched in MEDLINE, EMBASE, Cochrane library, WHO International Clinical Trial Registration Platform, and Clinical Trial.gov by 2015.5; and the effectiveness-, perioperation- and complication-related outcomes were assessed by network meta-analysis. 36 studies involving 3831 patients were included. Holmium laser through resection and enucleation had the best efficacy in maximum flow rate. Thulium laser through vapo-resection was superior in improving international prostate symptom score and holmium laser through enucleation was the best for post-voiding residual volume improvement. Diode laser through vaporization was the rapidest in removing postoperative indwelling catheter, while TURP was the longest. TURP required the longest hospitalization and thulium laser through vapo-resection was relatively shorter. Holmium and thulium lasers seem to be relatively better in surgical efficacy and safety, so that these two lasers might be preferred in selection of optimal laser surgery. Actually, more large-scale and high quality head-to-head RCTs are suggested to validate the conclusions. PMID:27009501

  5. Effect of Low-power Laser on Treatment of Orofacial Pain

    Directory of Open Access Journals (Sweden)

    Hamid Reza Khalighi

    2010-09-01

    Full Text Available Low-power lasers are a group of lasers with a power less than 250 mW and unlike high-power lasers they have no effect on tissue temperature; they produce light-dependent chemical reactions in tissues. These lasers have analgesic features with their ability to trigger reactions that reduce pain and inflammatory mediators. Low-power lasers can also be used instead of needles in acupuncture to decrease pain. Due to these features they have been used in the treatment of orofacial pain, including tooth hypersensitivity, post-operative flare-ups, mucositis, facial myalgia, temporomandibular joint disorders and neuralgia. In this article we review the effects of low-power lasers and their success rate in different studies. As the name implies (LASER: Light Amplification by the Stimulated Emission of Radiation, laser amplifies light by stimulated and excited radiation; in other words, it is amplification of excited light emission. Such radiation usually has some characteristic features, including mono-chromaticity, coherency, high intensity and polarity. There are various classifications for lasers based on their active material (solid, fluid and gas, wavelength, emission type and power.

  6. Implementation of laser technology and treatment at county level in the Swedish Public Dental Service.

    Science.gov (United States)

    Bergholm, Åsa; Östberg, Anna-Lena; Gabre, Pia

    2014-01-01

    The aim of this study was to obtain an understanding of the factors that affected the way new technology and methods were used in dentistry after a training program. A qualitative research method was used to collect data. Nine dentists working in the Public Dental Service (PDS) in Uppsala County in Sweden agreed to be interviewed in the study. They worked in five different clinics, all with laser equipment, and had received training in the use of lasers. The interviews were tape recorded and transcribed, and were analysed using manifest and latent qualitative content analysis. The categories in this study were identified as "Prerequisites and obstacles to imple- mentation", "Attitudes to laser technology and treatments" and "Laser technology in the future'". The dentists described working with lasers as complicated and problematic. They had concerns about the method relating to the working environment, evidence of efficacy of treatment, costs, and benefits for patients and dentists. The main finding was that the decision to adopt the technology seemed to be based on individual perceptions of the value of lasers compared to other ways of achieving the same goal. They provided uniform proposals regarding how an organization should implement new methods, including an emphasis on the importance of preparation and having opportunities to be able to test and evaluate the technology. Another important factor was support from surrounding staff, colleagues and management. Despite all the barriers, the respondents were positive about working with lasers in the future, mainly due to their belief that patients would demand laser treatment. In conclusion both individual and organizational factors affected the extent to which the respondents used the laser. The main finding was the individual perception of the value of lasers compared to other methods which could achieve the same goal.

  7. Near-UV laser treatment of extrinsic dental enamel stains.

    Science.gov (United States)

    Schoenly, J E; Seka, W; Featherstone, J D B; Rechmann, P

    2012-04-01

    The selective ablation of extrinsic dental enamel stains using a 400-nm laser is evaluated at several fluences for completely removing stains with minimal damage to the underlying enamel. A frequency-doubled Ti:sapphire laser (400-nm wavelength, 60-nanosecond pulse duration, 10-Hz repetition rate) was used to treat 10 extracted human teeth with extrinsic enamel staining. Each tooth was irradiated perpendicular to the surface in a back-and-forth motion over a 1-mm length using an ∼300-µm-diam 10th-order super-Gaussian beam with fluences ranging from 0.8 to 6.4 J/cm(2) . Laser triangulation determined stain depth and volume removed by measuring 3D surface images before and after irradiation. Scanning electron microscopy evaluated the surface roughness of enamel following stain removal. Fluorescence spectroscopy measured spectra of unbleached and photobleached stains in the spectral range of 600-800 nm. Extrinsic enamel stains are removed with laser fluences between 0.8 and 6.4 J/cm(2) . Stains removed on sound enamel leave behind a smooth enamel surface. Stain removal in areas with signs of earlier cariogenic acid attacks resulted in isolated and randomly located laser-induced, 50-µm-diam enamel pits. These pits contain 0.5-µm diam, smooth craters indicative of heat transfer from the stain to the enamel and subsequent melting and water droplet ejection. Ablation stalling of enamel stains is typically observed at low fluences (Laser ablation of extrinsic enamel stains at 400 nm is observed to be most efficient above 3 J/cm(2) with minimal damage to the underlying enamel. Unsound underlying enamel is also observed to be selectively removed after irradiation. Copyright © 2012 Wiley Periodicals, Inc.

  8. [INVITED] Laser gas assisted treatment of Ti-alloy: Analysis of surface characteristics

    Science.gov (United States)

    Yilbas, B. S.; Ali, H.; Karatas, C.

    2016-04-01

    Laser gas assisted treatment of Ti6Al4V alloy surface is carried out and nitrogen/oxygen mixture with partial pressure of PO2/PN2=1/3 is introduced during the surface treatment process. Analytical tools are used to characterize the laser treated surfaces. The fracture toughness at the surface and the residual stress in the surface region of the laser treated layer are measured. Scratch tests are carried out to determine the friction coefficient of the treated surface. It is found that closely spaced regular laser scanning tracks generates a self-annealing effect in the laser treated layer while lowering the stress levels in the treated region. Introducing high pressure gas mixture impingement at the surface results in formation of oxide and nitride species including, TiO, TiO2, TiN and TiOxNy in the surface region. A dense layer consisting of fine size grains are formed in the surface region of the laser treated layer, which enhances the microhardness at the surface. The fracture toughness reduces after the laser treatment process because of the microhardness enhancement at the surface. The residual stress formed is comprehensive, which is in the order of -350 MPa.

  9. Outcomes of treatment of nine cases of recalcitrant severe hidradenitis suppurativa with carbon dioxide laser.

    Science.gov (United States)

    Madan, V; Hindle, E; Hussain, W; August, P J

    2008-12-01

    Hidradenitis suppurativa (HS) is a chronic and often a recalcitrant inflammatory skin condition. To present the results of carbon dioxide (CO2) laser treatment of recalcitrant HS in nine patients who had failed to improve on medical and other surgical treatments. HS lesions consisting of abscesses, sinuses and granulation tissue were completely excised using the cutting mode of a CO2 laser, leaving only healthy residual subcutaneous fat. The wounds were closed by primary intention where possible and left to granulate otherwise. Outcomes were determined by clinical review and questionnaire. Twenty-seven sites were treated in 19 sessions on nine patients. Seven procedures were performed under general anaesthesia and 12 under local. All patients rated their postoperative discomfort as less or equal to their preoperative state. Seven of the nine patients had complete remission for 12 months or longer after their last laser treatment and ceased all medications. High levels of patient satisfaction were reported with CO2 laser treatment. The main complication was axillary scar contracture in two patients but this was insufficient to limit limb movement. CO2 laser treatment should be considered as a treatment option in recalcitrant HS, where multiple medical treatments have been ineffective.

  10. Treatment of onychomycosis using radiation of excimer laser

    Czech Academy of Sciences Publication Activity Database

    Urzová, J.; Jelínek, Miroslav; Mikšovský, Jan; Kymplová, J.

    2013-01-01

    Roč. 647, JAN (2013), s. 636-641 ISSN 1022-6680 R&D Projects: GA MŠk LD12069 Institutional support: RVO:68378271 Keywords : excimer laser * UV-C radiation * nails * onychomycosis Subject RIV: BM - Solid Matter Physics ; Magnetism

  11. The treatment of late radiation skin ulcers by laser radiation

    International Nuclear Information System (INIS)

    Kim, Yu.A.; Klimanov, M.E.; Bardychev, M.S.

    1985-01-01

    There are presented the results of laser stimulation of reparation processes in 25 patients with late radiation skin ulcers. Short-term therapeutic results turned out to be favorable in 18 (72%) patients, a complete cicatrization of ulcers was observed in 9 patients, significant improvement in 9

  12. Excimer laser for the treatment of psoriasis: safety, efficacy, and patient acceptability

    Directory of Open Access Journals (Sweden)

    Abrouk M

    2016-12-01

    Full Text Available Michael Abrouk,1 Ethan Levin,2 Merrick Brodsky,1 Jessica R Gandy,1 Mio Nakamura,2 Tian Hao Zhu,3 Benjamin Farahnik,4 John Koo,2 Tina Bhutani2 1Irvine School of Medicine, Irvine, 2Department of Dermatology, Psoriasis and Skin Treatment Center, University of California, San Francisco, 3Department of Dermatology, University of Southern California Keck School of Medicine, Los Angeles, CA, 4Department of Dermatology, University of Vermont College of Medicine, Burlington, VT, USA Introduction: The 308 nm excimer laser is a widely used device throughout the field of dermatology for many diseases including psoriasis. Although the laser has demonstrated clinical efficacy, there is a lack of literature outlining the safety, efficacy, and patient acceptability of the excimer laser. Methods: A literature search on PubMed was used with combinations of the terms “excimer”, “excimer laser”, “308 nm”, “psoriasis”, “protocol”, “safety”, “efficacy”, acceptability”, “side effects”, and “dose”. The search results were included if they contained information pertaining to excimer laser and psoriasis treatment and description of the safety, efficacy, and patient acceptability of the treatment. Results: The 308 nm excimer laser is generally safe and well tolerated with minimal side effects including erythema, blistering, and pigmentary changes. It has a range of efficacies depending on the protocol used with several different treatment protocols, including the induration protocol, the minimal erythema dose protocol, and the newer minimal blistering dose protocol. Conclusion: Although the excimer laser is not a first-line treatment, it remains an excellent treatment option for psoriasis patients and has been demonstrated to be an effective treatment with little to no side effects. Keywords: excimer, laser, 308 nm, psoriasis, safety, efficacy

  13. Patient Self-Report of Prior Laser Treatment Reliably Indicates Presence of Severe Diabetic Retinopathy

    Science.gov (United States)

    GRASSI, MICHAEL A.; MAZZULLA, D. ANTHONY; KNUDTSON, MICHAEL D.; HUANG, WENDY W.; LEE, KRISTINE E.; KLEIN, BARBARA E.; NICOLAE, DAN L.; KLEIN, RONALD

    2009-01-01

    PURPOSE To determine whether patient self-report of prior laser treatment can be used as a reliable tool for assessing the presence of severe diabetic retinopathy. DESIGN This was a retrospective study on two groups of diabetic subjects. METHODS One hundred patients with diabetes were recruited from the general eye and retina clinics at the University of Chicago Hospitals. The patients were asked, “Have you ever received laser treatment for your diabetic eye disease (DED)?” A chart review was then conducted noting if the patient had received either focal laser treatment for diabetic macular edema or panretinal photocoagulation for proliferative diabetic retinopathy. Data from the Wisconsin Epidemiological Study of Diabetic Retinopathy (WESDR) were also analyzed. Participant responses to the question “Have you had laser photocoagulation treatment for your eyes?” were analyzed with documentation of photocoagulation scars determined by grading seven-standard field color fundus photographs. RESULTS In the University of Chicago group, 96 of 100 (96%) of patients were accurate in reporting whether they had received previous laser treatment for DED (sensitivity 95.8%, specificity 96.1%, and positive predictive value 88.5%). In the WESDR analysis, 2,329 of 2,348 (99%) of participants were accurate in reporting whether they had prior laser treatment for DED (sensitivity 96.0%, specificity 99.5%, and positive predictive value 95.6%). CONCLUSIONS The high sensitivity and specificity of our results validate the use of patient self-report as a useful tool in assessing past laser treatment for severe diabetic retinopathy. Patient self-report may be a useful surrogate to clinical examination or medical record review to determine the presence of severe diabetic retinopathy. PMID:19054495

  14. Fractional CO2 Laser Resurfacing as Monotherapy in the Treatment of Atrophic Facial Acne Scars.

    Science.gov (United States)

    Majid, Imran; Imran, Saher

    2014-04-01

    While laser resurfacing remains the most effective treatment option for atrophic acne scars, the high incidence of post-treatment adverse effects limits its use. Fractional laser photothermolysis attempts to overcome these limitations of laser resurfacing by creating microscopic zones of injury to the dermis with skip areas in between. The aim of the present study is to assess the efficacy and safety of fractional CO2 laser resurfacing in atrophic facial acne scars. Sixty patients with moderate to severe atrophic facial acne scars were treated with 3-4 sessions of fractional CO2 laser resurfacing at 6-week intervals. The therapeutic response to treatment was assessed at each follow up visit and then finally 6 months after the last laser session using a quartile grading scale. Response to treatment was labelled as 'excellent' if there was >50% improvement in scar appearance and texture of skin on the grading scale while 25-50% response and resurfacing as monotherapy is effective in treating acne scars especially rolling and superficial boxcar scars with minimal adverse effects.

  15. Comparison between carbondioxide laser and cold instruments in treatment of vocal nodule

    International Nuclear Information System (INIS)

    Kundi, N.A.; Qayyum, A.; Ahmed, B.; Raza, M.

    2013-01-01

    Background: Vocal cord nodules are one of the most frequent disorders in both children and adults who use their voice excessively. Main symptom with which patient presents is hoarseness of voice. The treatment in early stages is voice therapy. Various methods are used for its treatment e.g. surgical removal with cold instruments and carbon dioxide laser ablation. Response to the treatment is measured by improvement in voice quality. Objective: To compare the results of Carbon dioxide laser and cold instruments in the treatment of vocal nodule. Study Design: Quasi-experimental study. Place and Duration of Study: This study was conducted at Otolaryngology Department Combined Military Hospital Rawalpindi. Patients and Methods: In this study 50 patients undergoing treatment of vocal cord nodule were included, 25 patients were treated by surgical removal with cold instruments and 25 patients were treated with carbon dioxide laser ablation. The main comparative outcomes were measured by patients' perception of voice quality (worse, same, improved) one week post operatively. Results: Improvement in voice quality with carbon dioxide laser was found to be clinically superior. Voice quality was significantly improved as compared to cold surgical instruments. Conclusion: Carbon dioxide laser causes early improvement in quality of voice as compared to cold instruments in the treatment of vocal nodules. (author)

  16. Multimodal scanning laser ophthalmoscopy for image guided treatment of age-related macular degeneration

    Science.gov (United States)

    Hammer, Daniel X.; Ferguson, R. D.; Patel, Ankit H.; Iftimia, Nicusor V.; Mujat, Mircea; Husain, Deeba

    2009-02-01

    Subretinal neovascular membranes (SRNM) are a deleterious complication of laser eye injury and retinal diseases such as age-related macular degeneration (AMD), choroiditis, and myopic retinopathy. Photodynamic therapy (PDT) and anti-vascular endothelial growth factor (VEGF) drugs are approved treatment methods. PDT acts by selective dye accumulation, activation by laser light, and disruption and clotting of the new leaky vessels. However, PDT surgery is currently not image-guided, nor does it proceed in an efficient or automated manner. This may contribute to the high rate of re-treatment. We have developed a multimodal scanning laser ophthalmoscope (SLO) for automated diagnosis and image-guided treatment of SRNMs associated with AMD. The system combines line scanning laser ophthalmoscopy (LSLO), fluorescein angiography (FA), indocyanine green angiography (ICGA), PDT laser delivery, and retinal tracking in a compact, efficient platform. This paper describes the system hardware and software design, performance characterization, and automated patient imaging and treatment session procedures and algorithms. Also, we present initial imaging and tracking measurements on normal subjects and automated lesion demarcation and sizing analysis of previously acquired angiograms. Future pre-clinical testing includes line scanning angiography and PDT treatment of AMD subjects. The automated acquisition procedure, enhanced and expedited data post-processing, and innovative image visualization and interpretation tools provided by the multimodal retinal imager may eventually aid in the diagnosis, treatment, and prognosis of AMD and other retinal diseases.

  17. HairMax LaserComb laser phototherapy device in the treatment of male androgenetic alopecia: A randomized, double-blind, sham device-controlled, multicentre trial.

    Science.gov (United States)

    Leavitt, Matt; Charles, Glenn; Heyman, Eugene; Michaels, David

    2009-01-01

    The use of low levels of visible or near infrared light for reducing pain, inflammation and oedema, promoting healing of wounds, deeper tissue and nerves, and preventing tissue damage has been known for almost 40 years since the invention of lasers. The HairMax LaserComb is a hand-held Class 3R lower level laser therapy device that contains a single laser module that emulates 9 beams at a wavelength of 655 nm (+/-5%). The device uses a technique of parting the user's hair by combs that are attached to the device. This improves delivery of distributed laser light to the scalp. The combs are designed so that each of the teeth on the combs aligns with a laser beam. By aligning the teeth with the laser beams, the hair can be parted and the laser energy delivered to the scalp of the user without obstruction by the individual hairs on the scalp. The primary aim of the study was to assess the safety and effectiveness of the HairMax LaserComb laser phototherapy device in the promotion of hair growth and in the cessation of hair loss in males diagnosed with androgenetic alopecia (AGA). This double-blind, sham device-controlled, multicentre, 26-week trial randomized male patients with Norwood-Hamilton classes IIa-V AGA to treatment with the HairMax LaserComb or the sham device (2 : 1). The sham device used in the study was identical to the active device except that the laser light was replaced by a non-active incandescent light source. Of the 110 patients who completed the study, subjects in the HairMax LaserComb treatment group exhibited a significantly greater increase in mean terminal hair density than subjects in the sham device group (p laser phototherapy device for the treatment of AGA in males.

  18. Evaluation of Mechanical Properties of Glass Fiber Posts Subjected to Laser Surface Treatments.

    Science.gov (United States)

    Barbosa Siqueira, Carolina; Spadini de Faria, Natália; Raucci-Neto, Walter; Colucci, Vivian; Alves Gomes, Erica

    2016-10-01

    The aim of this study was to evaluate the influence of laser irradiation on flexural strength, elastic modulus, and surface roughness and morphology of glass fiber posts (GFPs). Laser treatment of GFPs has been introduced to improve its adhesion properties. A total of 40 GFPs were divided into 4 groups according to the irradiation protocol: GC-no irradiation, GYAG-irradiation with erbium:yttrium-aluminum-garnet [Er:YAG], GCR-irradiation with erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG), and GDI-irradiation with diode laser. The GFP roughness and morphology were evaluated through laser confocal microscopy before and after surface treatment. Three-point bending flexural test measured flexural strength and elastic modulus. Data about elastic modulus and flexural strength were subjected to one-way ANOVA and Bonferroni test (p properties of GFPs.

  19. Fabrication of superhydrophilic and underwater superoleophobic metal mesh by laser treatment and its application

    Science.gov (United States)

    Yu, Peng; Lian, Zhongxu; Xu, Jinkai; Yu, Zhanjiang; Ren, Wanfei; Yu, Huadong

    2018-04-01

    In this paper, a lot of micron-sized sand granular structures were formed on the substrate of the stainless steel mesh (SSM) by laser treatment. The rough surface with sand granular structures showed superhydrophilic in air and superoleophobic under water. With its special wettability, the SSM by laser treatment could achieve the separation of the oil/water mixture, showing good durability and high separation efficiency, which was very useful in the practical application of large-scale oil/water separation facility for reducing the impacts of oil leaked on the environment. In addition, it showed that the laser-treated SSM had a very high separation rate. The development of the laser-treated SSM is a simple, environmental, economical and high-efficiency method, which provides a new approach to the production of high efficiency facilities for oil/water separation.

  20. Laser Annealing on the Surface Treatment of Thin Super Elastic NiTi Wire

    Science.gov (United States)

    Samal, S.; Heller, L.; Brajer, J.; Tyc, O.; Kadrevek, L.; Sittner, P.

    2018-05-01

    Here the aim of this research is annealing the surface of NiTi wire for shape memory alloy, super-elastic wire by solid state laser beam. The laser surface treatment was carried out on the NiTi wire locally with fast, selective, surface heat treatment that enables precisely tune the localized material properties without any precipitation. Both as drawn (hard) and straight annealing NiTi wire were considered for laser annealing with input power 3 W, with precisely focusing the laser beam height 14.3 % of the Z-axis with a spot size of 1 mm. However, straight annealing wire is more interest due to its low temperature shape setting behavior and used by companies for stent materials. The variable parameter such as speed of the laser scanning and tensile stress on the NiTi wire were optimized to observe the effect of laser response on the sample. Superelastic, straight annealed NiTi wires (d: 0.10 mm) were held prestrained at the end of the superelastic plateau (ε: 5 ∼6.5 %) above the superelastic region by a tensile machine ( Mitter: miniature testing rig) at room temperature (RT). Simultaneously, the hardness of the wires along the cross-section was performed by nano-indentation (NI) method. The hardness of the NiTi wire corresponds to phase changes were correlated with NI test. The laser induced NiTi wire shows better fatigue performance with improved 6500 cycles.

  1. Emissive spectra of shock-heated argon

    International Nuclear Information System (INIS)

    Tang Jingyou; Gu Yan; Peng Qixian; Bai Yulin; Li Ping

    2003-01-01

    To study the radiant properties of argon under weak shock compression, an aluminum target filled with gaseous argon at ambient states was impacted by a tungsten alloy projectile which was launched from a two-stage light gun to 2.00 km/s. The radiant signals of single shock-compressed argon were recorded by a six-channel pyrometer and oscilloscopes, which varied with time linearly for the five channels from 405 nm to 700 nm and exponentially for the channel 800 nm, and the corresponding velocity of shock wave was determined to be 4.10 ± 0.09 km/s. By the present experiment, it has been shown that the absorbability of the shock-heated argon is low for visual light and the optical depths of argon gas turn from thin to thick as wavelengths gradually increase. The time-resolved spectra in the rising-front of the radiant signal in the re-shocked argon were recorded by means of an OMA, and strong emissive spectrum bands near 450 nm light-wave length but no linear spectrum were found. The emissive spectrum properties of shock-compression argon were qualitatively explained by the state parameters and ionization degree

  2. Endovenous Laser Ablation as a Treatment for Postsurgical Recurrent Saphenous Insufficiency

    International Nuclear Information System (INIS)

    Anchala, Praveen R.; Wickman, Christopher; Chen, Richard; Faundeen, Tonya; Pearce, William; Narducy, Lisa; Resnick, Scott A.

    2010-01-01

    The purpose of this study was to investigate the safety and efficacy of endovenous laser ablation as a treatment for recurrent symptomatic saphenous insufficiency occurring after saphenous vein ligation and stripping. A single-center retrospective review of patients who received endovenous laser ablation as a treatment for recurrent symptomatic saphenous insufficiency after ligation and stripping between November 2003 and October 2006 was performed. Fifty-six insufficient saphenous systems were identified in 38 patients. Follow-up consisted of a clinical examination in all patients as well as selective lower-extremity duplex ultrasound as clinically indicated. All 38 patients demonstrated complete closure of the insufficient saphenous vein by clinical examination and/or duplex ultrasound evaluation. Preoperative symptoms resolved after treatment in all 38 patients. No major complications were identified. Endovenous laser ablation of recurrent symptomatic saphenous venous insufficiency is a safe and effective treatment in patients who develop recurrent symptoms after saphenous vein ligation and stripping.

  3. A New Approach for the Treatment of Lateral Periodontal Cysts with an 810-nm Diode Laser.

    Science.gov (United States)

    Isola, Gaetano; Matarese, Giovanni; Lo Giudice, Giuseppe; Briguglio, Francesco; Alibrandi, Angela; Crupi, Andrea; Cordasco, Giancarlo; Ramaglia, Luca

    The aim of this study was to test whether the combination of diode laser therapy and surgical treatment for a lateral periodontal cyst (LPC) would result in greater clinical improvement compared with surgery alone. A total of 18 patients with LPCs were assessed for eligibility for this study. At baseline, each patient was randomly allocated to one of two regimens: diode laser plus surgery (test group) or traditional surgical treatment alone (control group). Healing parameters were assessed at 7 to 21 days to monitor short-term complications, and periodontal parameters were assessed at 3, 6, and 12 months to evaluate long-term healing. The test group demonstrated highly significant differences in both the short-term and long-term parameters compared with the control group. This study showed that diode laser treatment results in a shorter wound-healing period and could be considered valuable for the surgical treatment of LPCs.

  4. Comparative analysis of the development of collateral vessels in macular edema due to branch retinal vein occlusion following grid laser or ranibizumab treatment

    Directory of Open Access Journals (Sweden)

    Kokolaki AE

    2015-09-01

    Full Text Available Afroditi Eleni Kokolaki, Ilias Georgalas, Chryssanthi Koutsandrea, Athanasios Kotsolis, Maria Niskopoulou, Ioannis LadasDepartment of Ophthalmology, University of Athens, Athens, Greece Purpose: To evaluate the differences in the development of collateral vessels in patients with macular edema due to branch retinal vein occlusion (BRVO after treatment with either grid laser or ranibizumab (RNB.Methods: Comparative study including patients with macular edema due to acute BRVO and best-corrected visual acuity (BCVA between 20/40 and 20/200. The sample was divided into two groups according to the treatment applied: laser group, including eyes treated with Argon laser when retinal hemorrhages were sufficiently absorbed to perform the treatment, and RNB group,  including patients treated initially with one monthly intravitreal injection for a period of 3 months of RNB and more injections according to need thereafter.. Before treatment patients in both groups, received a complete ophthalmic examination, including BCVA, fundus examination, optical coherence tomography, fundus color photography, and fundus fluorescein angiography (FA. This same protocol of examination was repeated in every visit after treatment, except FA that was only repeated every 3 months. The detection of the collateral vessels was done by two experienced examiners based on the analysis of the early phase of the FA. If there was a discrepancy in their judgment, the criterion of a third examiner evaluating the FA was considered.Results: Mean baseline BCVA was 0.86±0.26 and 0.82±0.25 (logMAR [logarithm of the minimum angle of resolution] in the RNB and laser groups, respectively (P=0.83. At the end of the follow-up, mean BCVA was 0.38±0.18 and 0.64±0.33 (logMAR in the RNB and laser groups, respectively. The difference in the final BCVA between both groups was statistically significant (P=0.002. Collaterals developed in both groups; 66.67% of patients (14 out of 21

  5. Evaluation of an ablative and non-ablative laser procedure in the treatment of striae distensae

    Directory of Open Access Journals (Sweden)

    Sule Gungor

    2014-01-01

    Full Text Available Background: Striae distensae or stretch marks are atrophic linear dermal scars with epidermal atrophy. There are many therapeutic options for management, but no consistently effective modality is available yet. Objective: We compared the efficacy of 1064 nm long pulse (LP Nd: YAG laser and 2940 nm variable square pulse (VSP erbium: YAG laser in the treatment of striae distensae. Methods: Twenty female volunteers (Fitzpatrick skin types II-V aged between 20 and 40 years with striae (3 patients with the rubra type and 17 with the alba type were enrolled in the study. The duration of striae ranged from 4 months to 12 years. Lesions were located on the abdomen in all patients except one patient who had striae on the arms and two patients with striae in the lumbar region. Treatments were randomly allocated to both sides of the body in each patient, one side being treated with VSP erbium: YAG laser and the opposite side with LP Nd: YAG laser. All subjects were treated monthly for a total of three treatments. Two 3-mm punch biopsies were obtained from six subjects, both of the same striae, one before the first treatment and one 4 weeks after the last session. Results: Response was evaluated clinically by photographic comparison and was found to be poor in 17 subjects, both on the LP Nd: YAG laser treated side and VSP erbium YAG laser treated side. All these patients had mature lesions (striae distensae alba. Three subjects had a moderate response on both sides; these patients′ striae were immature (striae distensae rubra. Histologically, elastic fibers were slightly increased in post-treatment samples compared with pretreatment skin biopsies. Conclusion: We observed no satisfactory clinical improvement in striae distensae alba lesions although histopathological changes were seen. We suggest that variable square pulse Er: YAG and long pulse Nd: YAG lasers are not useful in the treatment of striae distensae alba.

  6. Drift velocity of free electrons in liquid argon

    International Nuclear Information System (INIS)

    Walkowiak, W.

    2000-01-01

    A measurement of the drift velocity of free electrons in liquid argon has been performed. Free electrons have been produced by photoelectric effect using laser light in a so-called 'laser chamber'. The results on the drift velocity v d are given as a function of the electric field strength in the range 0.5 kV/cm≤|E|≤12.6 kV/cm and the temperature in the range 87 K≤T≤94 K. A global parametrization of v d (|E|,T) has been fitted to the data. A temperature dependence of the electron drift velocity is observed, with a mean value of Δv d /(ΔT v d )=(-1.72±0.08)%/K in the range of 87-94 K

  7. Successful treatment of laser induced hypopigmentation with narrowband ultraviolet B targeted phototherapy

    Directory of Open Access Journals (Sweden)

    Venkataram Mysore

    2013-01-01

    Full Text Available Q-switched 1064 nm neodymium-doped yttrium aluminium garnet (Qs 1064 nm Nd: YAG laser plays an important role in the treatment of pigmentary skin disorders, including tattoos. Although it has high efficacy and safety, adverse effect like hypopigmentation may occur causing anxiety to patients. We present a case report of Qs 1064 nm Nd: YAG laser induced hypopigmentation which was successfully treated with ultraviolet B targeted phototherapy, with rapid and satisfactory re-pigmentation.

  8. Argon cover gas purity control on LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hiroshi; Kobayashi, Takayoshi [PNC (Japan); Ishiyama, Satoshi [Toshiba (Japan); Motonaga, Tetsuji [Hitachi (Japan)

    1987-07-01

    Various control methods on chemical impurities and radioactive materials (fission products) in the primary argon gas of LMFBRs' have been studied based on experiences in Joyo and results of research and development. These results are reflected on MONJU design. On-line gas chromatographs are installed both in the Primary and in the Secondary Argon Gas Systems in JOYO. Also, chemical analysis has been done by batch sampling in JOYO. Though the rise of impurity concentration had been measured after periodical fuel exchange operation, impurity concentration has been controlled sufficiently under target control limits. In MONJU detailed design, the Rare Gas Removal and Recovery System which consisted of cryogenic distillation equipment had been eliminated and the capacity of Charcoal Beds in the Primary Argon Gas System has been improved to keep the concentration of radioactive materials sufficient low levels. The necessity to control the impurities in fresh argon gas which is supplied to the Primary Argon Gas System is now considered to keep the concentration of Kr and Xe isotopes in specified level, because their isotopes may make background rise for the Tagging Gas Failed Fuel Detection and Location System. Based on various investigations performed on sodium vapor trapping to obtain its detailed characteristics, design specifications and operating conditions of MONJU's Vapor Traps have been decided. To keep the level of radioactivity in gaseous effluents to the environment as low as reasonably achievable, the following means are now adopted in MONJU: the Primary Argon Gas System is composed of a closed recirculating path, but the exhaust gas discharged has different path after the Charcoal Beds; fresh argon gas is blown down to prevent Primary Argon Gas from releasing to the circumference during opening of the primary argon gas boundary, such as fuel exchange operations. (author)

  9. Use of krypton laser stimulation in the treatment of dry eye syndrome

    Science.gov (United States)

    Kecik, Tadeusz; Switka-Wieclawska, Iwona; Ciszewska, Joanna; Portacha, Lidia

    1991-08-01

    We''d like to present the use of krypton laser stimulation in the treatment of dry eye syndrom. 10 patients with dry eye syndrom were treated with irradiation of the lacrimal gland. Schirmer test and break up time were performed before and after therapy. After 10 days of treatment we observed higher value of secreted tear amount.

  10. Characterization of weakly ionized argon flows for radio blackout mitigation experiments

    Science.gov (United States)

    Steffens, L.; Koch, U.; Esser, B.; Gülhan, A.

    2017-06-01

    For reproducing the so-called E × B communication blackout mitigation scheme inside the L2K arc heated facility of the DLR in weakly ionized argon §ows, a §at plate model has been equipped with a superconducting magnet, electrodes, and a setup comprising microwave plasma transmission spectroscopy (MPTS). A thorough characterization of the weakly ionized argon §ow has been performed including the use of microwave interferometry (MWI), Langmuir probe measurements, Pitot probe pro¦les, and spectroscopic methods like diode laser absorption spectroscopy (DLAS) and emission spectroscopy.

  11. High-resolution measurement, line identification, and spectral modeling of the Kβ spectrum of heliumlike argon emitted by a laser-produced plasma using a gas-puff target

    International Nuclear Information System (INIS)

    Skobelev, I.Y.; Faenov, A.Y.; Dyakin, V.M.; Fiedorowicz, H.; Bartnik, A.; Szczurek, M.; Beiersdorfer, P.; Nilsen, J.; Osterheld, A.L.

    1997-01-01

    We present an analysis of the spectrum of satellite transitions to the He-β line in ArXVII. High-resolution measurements of the spectra from laser-heated Ar-gas-puff targets are made with spectral resolution of 10000 and spatial resolution of better than 50 μm. These are compared with tokamak measurements. Several different lines are identified in the spectra and the spectral analysis is used to determine the plasma parameters in the gas-puff laser-produced plasma. The data complement those from tokamak measurements to provide more complete information on the satellite spectra. copyright 1997 The American Physical Society

  12. Novel methotrexate soft nanocarrier/fractional erbium YAG laser combination for clinical treatment of plaque psoriasis.

    Science.gov (United States)

    Ramez, Shahenda A; Soliman, Mona M; Fadel, Maha; Nour El-Deen, Faisal; Nasr, Maha; Youness, Eman R; Aboel-Fadl, Dalea M

    2018-02-15

    Psoriasis is a commonly encountered chronic dermatological disease, presenting with inflammatory symptoms in patients. Systemic treatment of psoriasis is associated with several adverse effects, therefore the development of a customized topical treatment modality for psoriasis would be an interesting alternative to systemic delivery. The therapeutic modality explored in this article was the comparative treatment of psoriatic patients using nanoparticulated methotrexate in the form of jojoba oil-based microemulsion with or without fractional erbium YAG laser. Assessment parameters included follow-up photography for up to 8 weeks of treatment, estimation of the psoriasis severity [TES (thickness, erythema, scales)] score, and histopathological skin evaluation. The prepared methotrexate microemulsion was clinically beneficial and safe in treatment of psoriasis vulgaris. The concomitant use of the fractional laser provided improvement in the psoriatic plaques within shorter time duration (3 weeks compared to 8 weeks of treatment), presenting an alternative topical treatment modality for psoriasis vulgaris.

  13. Effect of laser treatment on first-intention incisional wound healing in ball pythons (Python regius).

    Science.gov (United States)

    Cole, Grayson L; Lux, Cassie N; Schumacher, Juergen P; Seibert, Rachel L; Sadler, Ryan A; Henderson, Andrea L; Odoi, Agricola; Newkirk, Kim M

    2015-10-01

    To evaluate effects of laser treatment on incisional wound healing in ball pythons (Python regius). 6 healthy adult ball pythons. Snakes were sedated, a skin biopsy specimen was collected for histologic examination, and eight 2-cm skin incisions were made in each snake; each incision was closed with staples (day 0). Gross evaluation of all incision sites was performed daily for 30 days, and a wound score was assigned. Four incisions of each snake were treated (5 J/cm(2) and a wavelength of 980 nm on a continuous wave sequence) by use of a class 4 laser once daily for 7 consecutive days; the other 4 incisions were not treated. Two excisional skin biopsy specimens (1 control and 1 treatment) were collected from each snake on days 2, 7, 14, and 30 and evaluated microscopically. Scores were assigned for total inflammation, degree of fibrosis, and collagen maturity. Generalized linear models were used to investigate the effect of treatment on each variable. Wound scores for laser-treated incisions were significantly better than scores for control incisions on day 2 but not at other time points. There were no significant differences in necrosis, fibroplasia, inflammation, granuloma formation, or bacterial contamination between control and treatment groups. Collagen maturity was significantly better for the laser-treated incisions on day 14. Laser treatment resulted in a significant increase in collagen maturity at day 14 but did not otherwise significantly improve healing of skin incisions.

  14. Virial Coefficients for the Liquid Argon

    Science.gov (United States)

    Korth, Micheal; Kim, Saesun

    2014-03-01

    We begin with a geometric model of hard colliding spheres and calculate probability densities in an iterative sequence of calculations that lead to the pair correlation function. The model is based on a kinetic theory approach developed by Shinomoto, to which we added an interatomic potential for argon based on the model from Aziz. From values of the pair correlation function at various values of density, we were able to find viral coefficients of liquid argon. The low order coefficients are in good agreement with theoretical hard sphere coefficients, but appropriate data for argon to which these results might be compared is difficult to find.

  15. Treatment of inflammatory facial acne vulgaris with combination 595-nm pulsed-dye laser with dynamic-cooling-device and 1,450-nm diode laser.

    Science.gov (United States)

    Glaich, Adrienne S; Friedman, Paul M; Jih, Ming H; Goldberg, Leonard H

    2006-03-01

    The 585-nm pulsed-dye laser and the 1,450-nm diode laser have been found effective for the treatment of mild-to-moderate inflammatory facial acne. This study was designed to evaluate the efficacy and safety of the combined treatment with the 595-nm pulsed-dye laser and the 1,450-nm diode laser for inflammatory facial acne. Fifteen patients with inflammatory facial acne were treated with a combination of the 595-nm pulsed-dye laser and the 1,450-nm diode laser. Patients' subjective response to treatment was evaluated regarding improvement in acne, acne scarring, oiliness, and redness of the skin. All patients had reductions in acne lesion counts. Mean lesion counts decreased 52% (P < 0.01), 63% (P < 0.01), and 84% (P < 0.01) after one, two, and three treatments, respectively. Patients described moderate-to-marked improvement in acne, acne scarring, and post-inflammatory erythema. Adverse effects were limited to mild, transient erythema. The combination of the 595-nm pulsed-dye laser and the 1,450-nm diode laser is safe and effective for the treatment of inflammatory facial acne, acne scarring, and post-inflammatory erythema. 2005 Wiley-Liss, Inc.

  16. Macular Structures, Optical Components, and Visual Acuity in Preschool Children after Intravitreal Bevacizumab or Laser Treatment.

    Science.gov (United States)

    Lee, Yung-Sung; See, Lai-Chu; Chang, Shu-Hao; Wang, Nan-Kai; Hwang, Yih-Shiou; Lai, Chi-Chun; Chen, Kuan-Jen; Wu, Wei-Chi

    2018-05-10

    To investigate the macular structures, optical components, and visual acuity in preschool-aged children with a history of type I retinopathy of prematurity who underwent either intravitreal bevacizumab (IVB), laser, or a combination of treatments. Comparative interventional case series. A referred medical center in Taiwan. 80 eyes from 42 patients (33 IVB-treated eyes from 17 children, 24 laser-treated eyes from 13 children, and 23 laser + IVB-treated eyes from 12 children). Spectral-domain optical coherence tomography. The retinal thickness in the foveal area and the associated morphologic changes in foveal depression. Compared with the laser-treated and laser + IVB-treated eyes, the IVB-treated eyes had less myopia and deeper anterior chamber depths but presented similar axial lengths and corneal curvatures (P = .001, .002, .95 and .16, respectively). The IVB-treated eyes had significantly thinner foveal, parafoveal, and perifoveal retinal thicknesses (P < .01 for all) and a higher incidence of foveal depression than the laser- or laser + IVB-treated eyes. The macular and subfoveal choroidal thicknesses did not differ among the groups (P = .21 and .63, respectively). Moreover, compared with the eyes treated with laser or laser + IVB, the IVB-treated eyes had better uncorrected visual acuity, although a significant difference was not observed in best-corrected visual acuity (P = .008 and .29, respectively). Compared with laser therapy, IVB-treated eyes were associated with deeper anterior chamber depths and thinner foveal, parafoveal and perifoveal thicknesses. Moreover, these IVB-treated eyes had less refractive errors and better uncorrected visual acuity. Copyright © 2018. Published by Elsevier Inc.

  17. Split lesion randomized comparative study between long pulsed Nd:YAG laser 532 and 1,064 nm in treatment of facial port-wine stain.

    Science.gov (United States)

    Al-Dhalimi, Muhsin A; Al-Janabi, Murtadha H

    2016-11-01

    Lasers have been the treatment of choice for Port-wine stain (PWS). However, only one type of laser is not a panacea for all PWS malformations. This is may be due to the great heterogeneity of phenotypic presentation of this congenital anomaly as color, depth, and the site of the lesion. For the treatment of PWS, flash lamp-pumped pulsed dye laser, carbon dioxide, argon, krypton, copper bromide, frequency-doubled neodymium:yttrium-aluminum-garnet (Nd:YAG), and also intense pulsed light sources can be used. To assess and compare the effectiveness of wavelength 532 and 1,064 nanometers (nm) long pulse Nd:YAG laser in the treatment of facial port-wine stain. This was a comparative therapeutic study for the treatment of facial port-wine stain. We divided the lesion into two halves, medial and lateral, and then each half was treated by 532 or 1,064 nm Nd:YAG. The sessions were done every 4 weeks for six sessions and follow-up after 3 months, then assess the response before and after the sessions and at the end follow-up period objectively (degree of improvement, Photo comparison) and subjectively (Patient satisfaction). Fourteen out of nineteen patients completed all sessions of the treatment, and the other five patients were defaulted from the study due to different causes, including marriage, poor compliance for treatment, and for unknown causes. They were 13 (92.85%) females and 1 (7.15%) male. The mean age of patients was 22.07 ± 9.003 years (range 8-44 years). Three patients (21.4%) were Fitzpatrick's skin type III and four patients (78.6%) were typed IV. There was no hypertrophy in any of the lesions. All facial PWSs lie along the distribution of the trigeminal nerve. Four patients (28.6%) have V1 (ophthalmic), 12 patients (85.7%) have V2 (maxillary), and 9 (64.3%) have V3 (mandibular). The color of PWSs was pink-red in eight patients (57.1%), dark-red in four patients (28.6%), and purple-dark two patients (14.3%). The improvement score for the halves of

  18. Time resolved laser induced fluorescence on argon intermediate pressure microwave discharges: Measuring the depopulation rates of the 4p and 5p excited levels as induced by electron and atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Palomares, J.M., E-mail: j.m.palomares-linares@tue.nl; Graef, W.A.A.D.; Hübner, S.; Mullen, J.J.A.M. van der, E-mail: jjamvandermullen@gmail.com

    2013-10-01

    The reaction kinetics in the excitation space of Ar is explored by means of Laser Induced Fluorescence (LIF) experiments using the combination of high rep-rate YAG–Dye laser systems with a well defined and easily controllable surfatron induced plasma setup. The high rep-rate favors the photon statistics while the low energy per pulse avoids intrusive plasma laser interactions. An analysis shows that, despite the low energy per pulse, saturation can still be achieved even when the geometrical overlap and spectral overlap are optimal. Out of the various studies that can be performed with this setup we confine the current paper to the study of the direct responses to the laser pump action of three 4p and one 5p levels of the Ar system. By changing the plasma in a controlled way one gets for these levels the rates of electron and atom quenching and therewith the total destruction rates of electron and atom collisions. Comparison with literature shows that the classical hard sphere collision rate derived for hydrogen gives a good description for the observed electron quenching (e-quenching) in Ar whereas for heavy particle quenching (a-quenching) this agreement was only found for the 5p level. An important parameter in the study of electron excitation kinetics is the location of the boundary in the atomic system for which the number of electron collisions per radiative life time equals unity. It is observed that for the Ar system this boundary is positioned lower than what is expected on grounds of H-like formulas. - Highlights: • Time resolved laser induced fluorescence at high repetition rate • Decay times as function of pressure, electron density and temperature • Measurement of total electron atom depopulation rates • Reasonable agreement of electron total rates with hard sphere approximations.

  19. Radio and chemioinduced oral mucositis treatment: comparison between conventional drug protocol and treatments with low intensity lasers

    International Nuclear Information System (INIS)

    Alencar, Anelise Ribeiro Peixoto

    2011-01-01

    In this clinical study verified the effects of low intensity laser in the prevention and treatment of oral mucositis radio and/or chemical induced. Thirty one patients with head and neck cancer were selected before being submitted to cancer exclusive radiotherapy or radio and associated chemotherapy. The patients were distributed into three randomly groups as follows: group 1- (control) conventional medicine treatment; group 2 - conventional medicine treatment and daily laser therapy as soon as grade two oral mucositis appeared; group 3 - conventional medicine treatment and daily laser therapy to be initiated immediately before radiotherapy sessions.The irradiation parameters were: wavelength of 660nm, potency of 100mW, continuous mode, punctual application, 2J energy on thirty pre-determined 30 points, with 20s of exposure per point. The control group received medical treatment which consisted in using a set of preventive and therapeutic approach for acute radiation-induced adverse effects. Results were evaluated observing occurrence and grade of oral mucositis, score of pain, loss of body mass, use of nasogastric sound line, internment and interruption of oncologic treatment due to oral mucositis. The results showed that the preventive protocol as used was the most effective in prevention and treatment of oral mucositis and that its daily application contributed in relieving the painful symptomatology so collaborating to maintain and/or bettering the life quality of oncologic patients. (author)

  20. New possibilities for efficient laser surface treatment by diode-pumped kW-class lasers

    Czech Academy of Sciences Publication Activity Database

    Brajer, Jan; Švábek, Roman; Rostohar, Danijela; Divoký, Martin; Lucianetti, Antonio; Mocek, Tomáš; Madl, J.; Pitrmuc, Z.

    2015-01-01

    Roč. 2015, Aug (2015), s. 1-3 ISSN 1823-3430 R&D Projects: GA MŠk ED2.1.00/01.0027; GA MŠk EE2.3.20.0143 Grant - others:HILASE(XE) CZ.1.05/2.1.00/01.0027; OP VK 6(XE) CZ.1.07/2.3.00/20.0143 Institutional support: RVO:68378271 Keywords : amplifier Subject RIV: BH - Optics, Masers, Lasers

  1. [Laser therapy and famotidine in complex restorative treatment of primary chronic gastroduodenitis].

    Science.gov (United States)

    Filimonov, R M; Musaeva, O M

    2003-01-01

    Primary chronic gastroduodenitis (PCG) is one of the most frequent diseases of the gastrointestinal tract. Timely and efficient treatment of patients with PCG promotes ulcer prevention. In this connection, an urgent problem of restorative medicine is to develop medical programs with active introduction of pharmacophysiotherapeutic complexes, in particular, laser therapy and anti-secretory preparation (famotidine) that increase therapeutic efficacy of treatment of this disease. To this end, we give results of treatment of 50 patients with primary chronic gastroduodenitis (26 having undergone laser therapy only, and 24 having had a combination of laser therapy and famotidine), which demonstrated that the complex action method has a more adequate effect on pathogenetic components in this disease than monotherapy.

  2. Low-intensity laser irradiation use for oral and lip precancer treatment

    Science.gov (United States)

    Kunin, Anatoly A.; Podolskaya, Elana E.; Stepanov, Nicolay N.; Petrov, Anatoly; Erina, Stanislava V.; Pankova, Svetlana N.

    1996-09-01

    Precancer and background diseases of the oral mucosa and lips, such as lichen planus, chronic ulcers and fissures, meteorological heilit, lupus erythematosus, after radiation heilit were treated by low-intensity laser irradiation. Laser therapy of the over-mentioned diseases was combined with medicinal treatment. All the patients were selected and treated in the limits of dispensary system. THe choice of diagnostic methods were made according to each concrete nosological form. A great attention was paid to the goal- directly sanitation of the oral cavity and treatment of attended internal diseases. The etiological factors were revealed and statistically analyzed. The results received during our researches demonstrated high effectiveness of laser irradiation combined with medicinal therapy in the treatment of oral mucosa and lips precancer diseases.

  3. Type 1 Retinopathy of Prematurity and Its Laser Treatment of Large Preterm Infants in East China.

    Science.gov (United States)

    Shan, Haidong; Ni, Yinqing; Xue, Kang; Yu, Jia; Huang, Xin

    2015-01-01

    To describe Type 1 retinopathy of prematurity (ROP) and its laser treatment outcomes in premature infants with birth weight > 1250 g in Eastern China. A retrospective review of 3175 ROP records was conducted at Shanghai Eye & ENT Hospital of Fudan University. The records were collected at the ROP clinic from 2006 to 2014, including their demographic and medical information such as gestational age, birth weight, supplemental oxygen therapy, systemic complications, ROP stage, location, presence of plus disease. All infants were examined by RetCam fundus camera. Those with Type 1 ROP were also examined by indirect ophthalmoscope before undergoing transpupillary laser treatment. A total of 12 infants (24 eyes) with Type 1 ROP and birth weight > 1250 g were enrolled. All infants enrolled had plus disease and ROP in zone II retina. Specifically, 16 eyes (67%) had stage 2 ROP. 8 eyes (33%) had stage 3 ROP. ROP regressed in 23 eyes (96%) following laser treatment. Partial retinal detachment developed in one eye (4%). No severe involution sequelaes or laser-related complications were recorded. Mean follow-up was 30±6 weeks. Type 1 ROP may occur in large premature infants who have undergone supplemental oxygen therapy. This Type 1 ROP is mainly located in zone II retina. Laser treatment is a safe and effective intervention for these infants.

  4. Functionalized Ormosil Scaffolds Processed by Direct Laser Polymerization for Application in Tissue Engineering

    DEFF Research Database (Denmark)

    Matei, A.; Schou, Jørgen; Canulescu, Stela

    The N,N’-(methacryloyloxyethyl triehtoxy silyl propyl carbamoyl-oxyhexyl)-urea hybrid methacrylate for applications in tissue engineering was synthesized and afterwards polymerized by direct laser polymerization using femtosecond laser pulses with the aim of using it for further applications...... in tissue engineering. The as-obtained scaffolds were modified either by low pressure argon plasma treatment or by using two different proteins (lysozyme, fibrinogen). For improved adhesion, the proteins were deposited by matrix assisted pulsed laser evaporation. The functionalized structures were tested...

  5. New and Advanced Picosecond Lasers for Tattoo Removal.

    Science.gov (United States)

    Adatto, Maurice A; Amir, Ruthie; Bhawalkar, Jayant; Sierra, Rafael; Bankowski, Richard; Rozen, Doran; Dierickx, Christine; Lapidoth, Moshe

    2017-01-01

    Early methods of tattoo removal ultimately resulted in unacceptable cosmetic outcomes. While the introduction of laser technology was an improvement over the existing chemical, mechanical, and surgical procedures, the use of nonselective tattoo removal with carbon dioxide and argon lasers led to scarring. Q-switched lasers with nanosecond (10-9) pulse domains were considered to have revolutionized tattoo treatment, by selectively heating the tattoo particles, while reducing the adverse sequelae to adjacent normal skin. Theoretical considerations of restricting pulse duration, to heat tattoo particles to higher temperatures, proposed the use of sub-nanosecond pulses to target particles with thermal relaxation times lower than the nanosecond pulses in Q-switched lasers. Initial studies demonstrated that picosecond (10-12) pulses were more effective than nanosecond pulses in clearing black tattoos. Advances in picosecond technology led to the development of commercially available lasers, incorporating several different wavelengths, to further refine pigment targeting. © 2017 S. Karger AG, Basel.

  6. Method for Cleaning Laser-Drilled Holes on Printed Wiring Boards by Plasma Treatment

    Science.gov (United States)

    Hirogaki, Toshiki; Aoyama, Eiichi; Minagi, Ryu; Ogawa, Keiji; Katayama, Tsutao; Matsuoka, Takashi; Inoue, Hisahiro

    We propose a new method for cleaning blind via holes after laser drilling of PWBs using oxygen plasma treatment. This report dealt with three kinds of PWB materials: epoxy resin and two kinds of aramid fiber reinforced plastics (AFRP: Technora or Kevlar fiber reinforcement). We observed the drilled holes after plasma treatment using both an optical and a scanning electric microscope (SEM). It was confirmed that adequate etching took place in the drilled holes by plasma treatment. We also compared the hole wall and hole bottom after plasma treatment with ones after chemical etching. It was clear that there was no damage to the aramid fiber tip on the hole wall, and that a smooth roughness of the hole wall was obtained by means of plasma treatment. As a result, we demonstrated that the plasma treatment is effective in cleaning the laser drilled holes of PWBs.

  7. Negative corona current pulses in argon and in mixture argon with SF6

    International Nuclear Information System (INIS)

    Zahoranova, A.; Zahoran, M.; Bucek, A.; Cernak, M.; Bosko, J.

    2004-01-01

    Waveforms of the first negative current pulses in a short negative point-to plane gap in pure argon and argon with SF 6 admixture have been investigated with a nanosecond time resolution at a gas pressure 50 kPa as a function of applied gap voltage and content of SF 6 in the mixture. We have made an attempt to explain the differences in the discharge development in pure argon and in argon with admixture of SF 6 based on the observed changes of the pulse shape. The experimental results obtained will be discussed in context with existing computer simulation models (Authors)

  8. Comparison of KrF and ArF excimer laser treatment of biopolymer surface

    Energy Technology Data Exchange (ETDEWEB)

    Michaljaničová, I. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Heitz, J.; Barb, R.A. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Sajdl, P. [Department of Power Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic)

    2015-06-01

    Highlights: • The influence of ArF and KrF laser on biopolymer surface was determined. • ArF laser acts predominantly on biopolymer surface. • PHB roughness is increased similarly for both applied wavelengths. • Roughness of nanostructures can be precisely controlled. • ArF laser introduces nitrogen on PHB surface. - Abstract: The goal of this work was the investigation of the impact of two different excimer lasers on two biocompatible and biodegradable polymers (poly-L-lactide and poly hydroxybutyrate). Both polymers find usage in medical and pharmaceutical fields. The polymers were modified by KrF and ArF excimer lasers. Subsequently the impact on surface morphology, surface chemistry changes, and thermal properties was studied by means of confocal and AFM microscopy, FTIR and XPS spectroscopy and DSC calorimetry. Under the same conditions of laser treatment it was observed that ArF laser causes more significant changes on surface chemistry, surface morphology and pattern formation on the polymers under investigation. The data obtained in this work can be used for a wide range of possible applications, in tissue engineering or in combination with metallization in electronics, e.g. for biosensors.

  9. Pain Reduction After Laser Acupuncture Treatment in Geriatric Patients with Knee Osteoarthritis: a Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Dwi R Helianthi

    2016-09-01

    Full Text Available Aim: to compare the effectiveness of active laser acupuncture with placebo on reducing pain intensity and improving functional outcome in geriatric patients with knee osteoarthritis (OA. Methods: a double-blind randomized controlled trial was conducted in geriatrics with knee OA at Medical Acupuncture Outpatient Clinic, Integrated Geriatric Outpatient Clinic, Rheumatology Outpatient Clinic of Cipto Mangunkusumo Hospital, Jakarta, during May to October 2015. Sixty two patients with knee OA  were randomly assigned into two groups: active laser acupuncture group or placebo laser acupuncture group. Interventions were carried out using a gallium aluminum arsenide laser device at the ST35 Dubi, ST36 Zusanli, SP9 Yinlingquan, GB34 Yanglingquan and EX - LE - 4 Neixiyan acupuncture points on the affected knee for ten sessions of treatment, i.e. twice a week. Patients were assessed using a visual analogue scale (VAS and Lequesne index at baseline, after four sessions, after nine sessions and at 2 weeks after the treatment had been stopped. Results: the VAS scores were significantly improved in the active laser acupuncture group compared to the placebo group. The evaluation of VAS scores was carried out after four treatment sessions (mean difference: 0.39; p<0.001, after nine treatment sessions (mean difference: 37.48; p<0.001 and at 2 weeks post intervention (mean difference: 39.15; p<0.001. The evaluation also showed significant improvement of Lequesne index after four treatment sessions (mean difference: 4.68; p<0.001, after nine treatment sessions (mean difference: 5.90; p<0.001 and at 2 weeks post intervention (mean difference: 6.48; p<0.001. Conclusion: active laser acupuncture is effective in reducing pain.

  10. Experimental studies of the argon-puff Z-pinch implosion process

    International Nuclear Information System (INIS)

    Huang Xianbin; Yang Libing; Gu Yuanchao; Deng Jianjun; Zhou Rongguo; Zou Jie; Zhou Shaotong; Zhang Siqun; Chen Guanghua; Chang Lihua; Li Fengping; Ouyang Kai; Li Jun; Yang Liang; Wang Xiong; Zhang Zhaohui

    2006-01-01

    A preliminary experiment for studying the argon-puff Z-pinch implosion process has been performed on the Yang accelerator. The ten-frame nanosecond temporal and spatial gated camera, visible high-speed scanning camera, differential laser interferometer, X-ray time integration pinhole camera and X-ray power system have been used to investigated the evolution of the argon-puff Z-pinch. Some typical results of argon-puff Z-pinch during implosion and pinch phase, including the 'zipper' effect, necking phenomenon, sausage instability, temperature changes and the effect of load current rise time, are given and analyzed as examples, and some relevant conclusions are drawn. (authors)

  11. Fractional CO2 laser treatment for vulvovaginal atrophy symptoms and vaginal rejuvenation in perimenopausal women

    Directory of Open Access Journals (Sweden)

    Arroyo C

    2017-08-01

    Full Text Available César Arroyo HM Montepríncipe University Hospital Laser Unit, Madrid, Spain Background: This study investigated a novel fractional carbon dioxide (CO2 laser for treatment of symptoms associated with vulvovaginal atrophy (VVA in perimenopausal women.Methods: The study included 21 perimenopausal women (mean age 45±7 years treated three times by CO2 laser resurfacing and coagulation of the vaginal canal tissue and mucosal tissue of the introitus. Vaginal health index (VHI scores were computed by the investigator at baseline and follow-ups. Subjects reported on sexual function, satisfaction, and improvement with treatment. A visual analog scale was used to measure discomfort with treatment.Results: Vaginal health and subject assessment of vaginal symptoms improved with successive treatments. At 12 weeks following the third treatment, 82% of the patients showed a statistically significant improvement in VHI (P<0.05. Additionally, 81% of subjects reported improvement in sexual gratification, 94% reported improvement in vaginal rejuvenation, and 100% reported satisfaction with treatment. VHI improvement remained significant at 6–8 months after treatments (P<0.01. Most patients (97% reported no to mild discomfort with treatment. Responses were mild and transient following treatment, with itching being the most commonly reported (20% side effect.Conclusion: In this study, fractional CO2 laser treatment was associated with improvement of vaginal health and amelioration of symptoms of VVA, resulting in improved sexual function in perimenopausal women. Treatment time was quick, and there was minimal discomfort associated with treatment. Investigation of clinical outcome in a larger study population is warranted. Keywords: genitourinary syndrome of menopause, vaginal rejuvenation, stress urinary incontinence, collagen remodeling, sexual dysfunction, vulvovaginal atrophy

  12. Treatment of recurrent pilonidal cysts with nd-YAG laser: report of our experience.

    Science.gov (United States)

    Dragoni, F; Moretti, S; Cannarozzo, G; Campolmi, P

    2018-02-01

    Surgical treatment remains the first-line therapy of pilonidal cyst but is associated with high levels of postoperative pain, adverse events and a recurrence rate of 30%. We report our experience with laser hair removal using the Nd-YAG laser for the treatment of pilonidal cyst. Ten patients affected by pilonidal cyst were examined and treated from October 2011 to November 2016. Treatments were carried out using the Nd-YAG laser (Deka M.E.L.A, Calenzano, Florence, Italy) at a wavelength of 1064 nm at 30-day interval. Nine patients were asymptomatic after the second treatment, while in one case the symptom disappeared after the fourth session. After 4-8 treatments, the pilonidal cyst had clinically disappeared and patients subjectively felt healed. In all cases, the soft-tissue ultrasounds performed before the first and after the last session showed the disappearance of the pilonidal cyst. In the follow-up, all the patients remained asymptomatic without any disease recurrence. Nd-YAG laser is an effective treatment for pilonidal cysts, providing excellent results with quick healing and no risk of serious adverse side-effects. It could be a very attractive alternative to open surgery, enabling patients to prevent the frequent and severe postoperative issues associated with surgery.

  13. Development of the medical apparatus for Doppler-controlled treatment of hemorrhoids using laser coagulation

    Directory of Open Access Journals (Sweden)

    Nikolay A. Gryaznov

    2017-12-01

    Full Text Available In the article authors present the concept of the surgical manipulator delivering laser radiation to the target area. For the implementation of Doppler-controlled treatment of hemorrhoids by laser coagulation, an important circumstance is the necessity to realize by means of the dopplerograph the possibility of controlling the efficiency of coagulation of the pathological vessel immediately after the impact, which will create the prerequisites for the formation of a program cycle with the inclusion of control elements by feedback. In this regard, the structure of the laser medical apparatus is developed, which allows determining the location, size and flow of arterial and venous vessels, performing laser coagulation of pathologically damaged sites under constant Doppler control. The developed adaptive power management system includes several functional units for the processing of the data from ultrasound scanner and the Doppler. Medical apparatus for minimally invasive treatment of hemorrhoids based on the laser coagulator and ultrasound Doppler will allow performing surgeries in automated and half-automated modes. The suggested medical apparatus helps to determine pathological vessels, choose the required radiation mode and provides vessel obliteration. Successful realization of constructive combination of real-time diagnostics and surgical manipulation with a laser can result in a unique minimally invasive solution to treat hemorrhoids that currently doesn’t have analogues.

  14. Laser treatment of amateur tattoos in Arabs in Kuwait: effectiveness and safety.

    Science.gov (United States)

    Qasem, Kholoud Darwish; Alotaibi, Mohammad Fehan

    2012-04-01

    Laser treatment of amateur tattoos on Fitzpatrick type V skin produces a considerable risk of complications because of the increased incidence of adverse pigmentary changes. The principle of selective photothermolysis predicts that the Q-switched alexandrite laser should be effective in removing tattoo ink with minimal side effects in patients with skin phototype V. To study the effectiveness of the Q-switched alexandrite (755 nm, 50 ns) laser in the treatment of amateur tattoos in Arabs in Kuwait. One hundred patients, each with multiple tattoos, were treated until total clearance. Fluences used ranged from 5 to 7 J/cm(2) with a spot size of 3 mm. Clinical evaluation was performed at baseline and at each follow-up visit until dyspigmentation resolved. Total clearing was observed in all tattoos after an average of six sessions. Both tattoo clearing and post-laser hypopigmentation (29%) and hyperpigmentation (38%) increased with higher fluences. In this prospective study, our findings suggest that the Q-switched alexandrite laser is an effective laser in removing amateur tattoos in patients with skin phototype V, but with a high incidence of pigmentary changes.

  15. Improving the properties of stainless steel electron-beam welds by laser treatment

    International Nuclear Information System (INIS)

    Wu Xueyi; Zhou Changchi

    1991-10-01

    For improving the properties of corrosion resistance of stainless steel, which is widely used in nuclear engineering, the technological test on rapid fusing and setting formed by using laser treatment in electron-beam welds on stainless steel was investigated and the analytical results of welding structure and properties were reported. The experimental results show that after laser treatment more finegrained structure in the surface of the welding centreline and welding heat-affected zone was observed. Segregation of chemical composition was reduced. Plasticity and corrosion resistance in the welding zone was increased. Intergranular corrosion of heat-affected zone was improved

  16. Low-energy laser in the treatment of alopecia of the scalp

    Science.gov (United States)

    Ciuchita, Tavi; Usurelu, Mircea; Antipa, Ciprian

    1997-12-01

    The authors tried to verify the efficacy of low energy laser (LEL) in scalp alopecia. Sixty patients were divided in two groups: A) laser group, 33 patients treated with both LEL and classical therapy; B) control group, 27 patients treated only with classical therapy, Before, during and after treatment, historical samples were done. For the group A the results were rather superior but in a twice shorter time shorter time than group B. The maintenance of the good results needed classical therapy for a long period. We conclude that LEL therapy could have a useful complementary method for the treatment of scalp alopecia.

  17. Conventional operation and laser therapy in the treatment of varicose veins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To evaluate the effectiveness of endovenous laser therapy and conventional therapy on the varicose of great saphenous vein. Methods: Thirty-two patients received endovenous laser therapy and 32 patients were operated by conventional therapy (high ligation and stripping). The observation results of great saphenous vein(GSV) were recorded by clinical evaluation and duplex ultrasound examination. And the operating time, intraoperative blood loss, time to become moveable, duration of hospitalization and degree of feeling pain were compared between the two groups. Results: Compared with conventional therapy, laser therapy had good curative effect with less complications and no scars and no pains. There were significant differences between the two groups (P<0.01). Conclusion: Laser therapy for varicose of great saphenous vein is better than the conventional therapy. It deserves to be widely used in clinical treatment.

  18. Effectiveness of soft tissue diode laser in treatment of oral mucosal lesions

    Directory of Open Access Journals (Sweden)

    Amanpreet Kaur

    2017-01-01

    Full Text Available Soft tissue diode lasers are becoming popular among clinicians due to their potential value in surgical procedures providing surface sterilization, dry surgical field, and increased patient acceptance. Two patients with different soft tissue lesions were selected, and soft tissue diode laser was used for excision and wound healing was assessed by visual method with photographs. No discomfort to the patient during and after the laser procedure was observed. Inspite of using minimal local anesthesia, avoiding placement of sutures, and not prescribing any antibiotics, minimal bleeding, no edema, and good wound healing was observed. We conclude that lasers treatments can be superior to conventional approaches with regards to easy ablation, decontamination, and hemostasis, and are less painful during and after the procedure.

  19. Laser treatment of an oral squamous papilloma in a pediatric patient: A case report

    Directory of Open Access Journals (Sweden)

    Ahmet Ferhat Misir

    2013-01-01

    Full Text Available Oral squamous papilloma is a benign proliferation of the stratified squamous epithelium, which results in a papillary or verrucous exophytic mass induced by human papilloma virus (HPV. These oral mucosa lesions are most often asymptomatic and have small progression. Laser assisted surgery is common nowadays with several advantages including successful hemostasis, devoid of sutures, wound sterilization and minimal post-operative pain and edema. The aim of this report is to present the oral squamous papilloma in a pediatric patient and its treatment with soft tissue laser. The lesion was excised with diode laser and the healing was uneventful in follow-up visit after one year. Oral squamous papillomas can be found in child′s oral cavity and laser dentistry can be used by dental clinicians to treat these kinds of oral lesions and should be considered as an alternative to conventional surgery.

  20. outcome of diode laser cyclophotocoagulation in neovascular ...

    African Journals Online (AJOL)

    Duke

    including, ruby, ND:YAG, argon, krypton and, more recently, trans scleral cyclophotocoagulation with the diode laser, which has been shown to be more effective with less side effects than the others. The diode laser, 810nm, has. 4,5 greater melanin absorption compared to other lasers. Of the various cyclodestructive laser ...

  1. Time resolved laser induced fluorescence on argon intermediate pressure microwave discharges: Measuring the depopulation rates of the 4p and 5p excited levels as induced by electron and atom collisions

    Science.gov (United States)

    Palomares, J. M.; Graef, W. A. A. D.; Hübner, S.; van der Mullen, J. J. A. M.

    2013-10-01

    The reaction kinetics in the excitation space of Ar is explored by means of Laser Induced Fluorescence (LIF) experiments using the combination of high rep-rate YAG-Dye laser systems with a well defined and easily controllable surfatron induced plasma setup. The high rep-rate favors the photon statistics while the low energy per pulse avoids intrusive plasma laser interactions. An analysis shows that, despite the low energy per pulse, saturation can still be achieved even when the geometrical overlap and spectral overlap are optimal. Out of the various studies that can be performed with this setup we confine the current paper to the study of the direct responses to the laser pump action of three 4p and one 5p levels of the Ar system. By changing the plasma in a controlled way one gets for these levels the rates of electron and atom quenching and therewith the total destruction rates of electron and atom collisions. Comparison with literature shows that the classical hard sphere collision rate derived for hydrogen gives a good description for the observed electron quenching (e-quenching) in Ar whereas for heavy particle quenching (a-quenching) this agreement was only found for the 5p level. An important parameter in the study of electron excitation kinetics is the location of the boundary in the atomic system for which the number of electron collisions per radiative life time equals unity. It is observed that for the Ar system this boundary is positioned lower than what is expected on grounds of H-like formulas.

  2. Serial in-office laser treatment of vocal fold leukoplakia: Disease control and voice outcomes.

    Science.gov (United States)

    Koss, Shira L; Baxter, Peter; Panossian, Haig; Woo, Peak; Pitman, Michael J

    2017-07-01

    Although vocal fold (VF) leukoplakia is commonly treated with in-office laser, there is no data on its long-term effectiveness. This study hypothesizes that VF leukoplakia treated by serial in-office laser results in long-term disease control with maintenance of voice and minimal morbidity. Retrospective review (2008-2015). Forty-six patients with VF leukoplakia treated by in-office KTP (potassium titanyl phosphate) or PDL (pulsed dye laser) were included. Median follow-up from final laser treatment was 19.6 months. Main outcomes included: 1) rate of disease control, 2) percentage of disease regression using ImageJ analysis. Secondary outcomes included vocal assessment using the Voice Handicap Index-10 (VHI-10). Patients underwent a median of 2 (range: 1-6) in-office laser treatments. Time between treatments was median 7.6 months. After final treatment, 19 patients (41.3%) had no disease; two patients (4.3%) progressed to invasive cancer; overall disease regression was median 77.1% (P office treatment only); failures were 13 patients (28.3%) who required operative intervention and two patients (4%) who underwent radiation. Compared to responders, failures demonstrated significantly shorter duration between treatments (median 2.3 vs. 8.9 months, P = 0.038) and significantly less regression (median 49.3% vs. 100%, P = 0.006). Serial outpatient KTP or PDL treatment of VF leukoplakia is effective for disease control with minimal morbidity and preservation of voice quality. We suggest that patients requiring repeated in-office treatment every 6 months may benefit from earlier operative intervention; other factors associated with in-office success remain unclear. 4. Laryngoscope, 127:1644-1651, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  3. Comparison between Er:YAG laser and bipolar radiofrequency combined with infrared diode laser for the treatment of acne scars: Differential expression of fibrogenetic biomolecules may be associated with differences in efficacy between ablative and non-ablative laser treatment.

    Science.gov (United States)

    Min, Seonguk; Park, Seon Yong; Moon, Jungyoon; Kwon, Hyuck Hoon; Yoon, Ji Young; Suh, Dae Hun

    2017-04-01

    Fractional Er:YAG minimizes the risk associated with skin ablation. Infrared diode laser and radiofrequency have suggested comparable improvements in acne scar. We compared the clinical efficacy of Er:YAG laser and bipolar radiofrequency combined with diode laser (BRDL) for the treatment of acne scars. Moreover, acute molecular changes of cytokine profile associated with wound healing have been evaluated to suggest mechanisms of improvement of acne scar. Twenty-four subjects with mild-to-moderate acne scars were treated in a split-face manner with Er:YAG and BRDL, with two treatment sessions, 4 weeks apart. Objective and subjective assessments were done at baseline, 1, 3, 7 days after each treatment and 4 weeks after last treatment. Skin biopsy specimens were obtained at baseline, 1, 3, 7, 28 days after one session of treatment for investigation of molecular profile of acute skin changes by laser treatment. Investigator's Global Assessment representing the improvement degree shows 2.1 (50%) in fractional Er:YAG and 1.2 (25%) in BRDL. Er:YAG induced the later and higher peak expression of TGFβs and collagenases, whereas BRDL induced earlier and lower expression of TGFβ and collagenases, relatively. PPARγ dropped rapidly after a peak in Er:YAG-treated side, which is associated with tissue inhibitor of metalloproteinase (TIMP) expression. We observed higher expression of TIMP after Er:YAG treatment compared with BRDL by immunohistochemistry, which may be associated with the expression of upregulation of collagen fibers. The superior efficacy of Er:YAG to BRDL in the treatment of acne scars may be associated with higher expression of collagen which is associated with differential expression of TGFβs, collagenases, PPARγ, and TIMP. Lasers Surg. Med. 49:341-347, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Nanoparticles for diagnostics and laser medical treatment of cartilage in orthopaedics

    Science.gov (United States)

    Baum, O. I.; Soshnikova, Yu. M.; Omelchenko, A. I.; Sobol, Emil

    2013-02-01

    Laser reconstruction of intervertebral disc (LRD) is a new technique which uses local, non-destructive laser irradiation for the controlled activation of regenerative processes in a targeted zone of damaged disc cartilage. Despite pronounced advancements of LRD, existing treatments may be substantially improved if laser radiation is absorbed near diseased and/or damaged regions in cartilage so that required thermomechanical stress and strain at chondrocytes may be generated and non-specific injury reduced or eliminated. The aims of the work are to study possibility to use nanoparticles (NPs) to provide spatial specificity for laser regeneration of cartilage. Two types of porcine joint cartilage have been impregnated with magnetite NPs: 1) fresh cartilage; 2) mechanically damaged cartilage. NPs distribution was studied using transition electron microscopy, dynamic light scattering and analytical ultracentrifugation techniques. Laser radiation and magnetic field have been applied to accelerate NPs impregnation. It was shown that NPs penetrate by diffusion into the mechanically damaged cartilage, but do not infiltrate healthy cartilage. Temperature dynamics in cartilage impregnated with NPs have been theoretically calculated and measurements using an IR thermo vision system have been performed. Laser-induced alterations of cartilage structure and cellular surviving have been studied for cartilage impregnated with NPs using histological and histochemical techniques. Results of our study suggest that magnetite NPs might be used to provide spatial specificity of laser regeneration. When damaged, the regions of cartilage impreganted with NPs have higher absorption of laser radiation than that for healthy areas. Regions containing NPs form target sites that can be used to generate laser-induced thermo mechanical stress leading to regeneration of cartilage of hyaline type.

  5. Hair regrowth through wound healing process after ablative fractional laser treatment in a murine model.

    Science.gov (United States)

    Bae, Jung Min; Jung, Han Mi; Goo, Boncheol; Park, Young Min

    2015-07-01

    Alopecia is one of the most common dermatological problems in the elderly; however, current therapies for it are limited by low efficacy and undesirable side effects. Although clinical reports on fractional laser treatment for various alopecia types are increasing, the exact mechanism remains to be clarified. The purposes of this study were to demonstrate the effect of ablative fractional laser treatment on hair follicle regrowth in vivo and investigate the molecular mechanism after laser treatment. Ablative CO2 fractional laser was applied to the shaved dorsal skin of 7-week-old C57BL/6 mice whose hair was in the telogen stage. After 12 mice were treated at various energy (10-40 mJ/spot) and density (100-400 spots/cm(2) ) settings to determine the proper dosage for maximal effect. Six mice were then treated at the decided dosage and skin specimens were sequentially obtained by excision biopsy from the dorsal aspect of each mouse. Tissue samples were used for the immunohistochemistry and reverse transcription polymerase chain reaction assays to examine hair follicle status and their related molecules. The most effective dosage was the 10 mJ/spot and 300 spots/cm(2) setting. The anagen conversion of hair was observed in the histopathological examination, while Wnt/β-catenin expression was associated with hair regrowth in the immunohistochemistry and molecular studies. Ablative fractional lasers appear to be effective for inducing hair regrowth via activation of the Wnt/β-catenin pathway in vivo. Our findings indicate that fractional laser treatment can potentially be developed as new treatment options for stimulating hair regrowth. © 2015 Wiley Periodicals, Inc.

  6. Lasers

    CERN Document Server

    Milonni, Peter W

    1988-01-01

    A comprehensive introduction to the operating principles and applications of lasers. Explains basic principles, including the necessary elements of classical and quantum physics. Provides concise discussions of various laser types including gas, solid state, semiconductor, and free electron lasers, as well as of laser resonators, diffraction, optical coherence, and many applications including holography, phase conjugation, wave mixing, and nonlinear optics. Incorporates many intuitive explanations and practical examples. Discussions are self-contained in a consistent notation and in a style that should appeal to physicists, chemists, optical scientists and engineers.

  7. Diffuse Urticarial Reaction Associated with Titanium Dioxide Following Laser Tattoo Removal Treatments.

    Science.gov (United States)

    Willardson, Hal Bret; Kobayashi, Todd T; Arnold, Jason G; Hivnor, Chad M; Bowen, Casey D

    2017-03-01

    Local and generalized allergic reactions following laser tattoo removal have been documented, but are rare. To our knowledge, this is the fourth documented case of widespread urticarial eruptions following laser tattoo removal treatment. Unlike previously documented cases, this patient's reaction was found to be associated with titanium dioxide within the tattoo and her symptoms were recalcitrant to medical therapy. A 46-year-old female experienced diffuse urticarial plaques, erythema, and pruritis following multiple laser tattoo removal treatments with an Nd:YAG laser. The systemic allergic reaction was recalcitrant to increasing doses of antihistamines and corticosteroids. The tattoo was finally surgically excised. The excised tissue was analyzed by scanning electron microscopy and energy-dispersive X-ray analysis and contained high levels of titanium dioxide. Two weeks following the excision, and without the use of medical therapy, the patient had complete resolution of her generalized urticaria. Ours is the first documented case of a diffuse urticarial reaction following laser tattoo removal treatments that shows a strong association to titanium dioxide within the tattoo pigment. Herein, we describe a novel surgical approach to treat recalcitrant generalized allergic reaction to tattoo pigment.

  8. Fracture behaviour of a magnesium–aluminium alloy treated by selective laser surface melting treatment

    International Nuclear Information System (INIS)

    Taltavull, C.; López, A.J.; Torres, B.; Rams, J.

    2014-01-01

    Highlights: • β-Mg 17 Al 12 presents fragile fracture behavior decreasing the ductility of AZ91D. • SLSM treatment only modifies the β-Mg 17 Al 12 phase whilst α-Mg remains unaltered. • In-situ SEM bending test allows to observe and data record of the crack propagation. • Eutectic microestructure of modified β-phase presents ductile fracture behaviour. • Fracture toughness of laser treated specimen is 40% greater than as-received alloy. - Abstract: Fracture behaviour of AZ91D magnesium alloy is dominated by the brittle fracture of the β-Mg 17 Al 12 phase so its modification is required to improve the toughness of this alloy. The novel laser treatment named as Selective Laser Surface Melting (SLSM) is characterized by the microstructural modification of the β-Mg 17 Al 12 phase without altering the α-Mg matrix. We have studied the effect of the selected microstructural modification induced by the laser treatment in the fracture behaviour of the alloy has been studied using in situ Scanning Electron Microscopy bending test. This test configuration allows the in situ observation of the crack progression and the record of the load–displacement curve. It has been observed that the microstructural modification introduced by SLSM causes an increase of 40% of the fracture toughness of the treated specimen. This phenomenon can be related with the transition from brittle to ductile fracture behaviour of the laser modified β-phase

  9. Laser Therapy in the Treatment of Achilles Tendinopathy: A Randomised Controlled Trial

    Science.gov (United States)

    Tumilty, Steve; Munn, Joanne; Haxby Abbott, J.; Mcdonough, Suzanne; Hurley, Deirdre A.; Basford, Jeffrey R.; David Baxter, G.

    2010-05-01

    Background: Low Level Laser Therapy (LLLT) has emerged as a possible treatment modality for tendinopathies. Human studies have investigated LLLT for Achilles Tendinopathy and the effectiveness remains contentious. Purpose: To assess the clinical effectiveness of Low-Level Laser Therapy (LLLT) in the management of Achilles Tendinopathy. Method: Forty patients were randomised into an active laser or placebo group; all patients, therapists and investigator were blinded to allocation. All patients were given an eccentric exercise program and irradiated 3 times per week for 4 weeks with either an active or placebo laser at 6 standardized points over the affected tendons. Irradiation parameters in the active laser group were: 810 nm, 100 mW, applied to 6 points on the tendon for 30 seconds giving a dose of 3 J per point and 18 J per session; power density 100 mW/cm2. Outcome measures were the VISA-A questionnaire and a visual analogue scale of pain. Patients were measured before treatment, at 4 and 12 weeks. ANCOVA was used to analyze data, using the effects of baseline measurements as a covariate. Results: Within groups, there were significant improvements (p0.05). Conclusion: This use of the above parameters demonstrated no added benefit of LLLT over that of eccentric exercise in the treatment of Achilles Tendinopathy.

  10. Laboratory model for the study and treatment of traumatic tattoos with the Q-switched ruby laser

    Science.gov (United States)

    Silverman, Richard T.; Lach, Elliot

    1994-09-01

    The outcome of laser tattoo removal is dependent on the type of laser and characteristics of the tattoo. A rabbit model was developed to study the Q-switched ruby laser in the treatment of traumatic tattooing. On the backs of white New Zealand rabbits, three 3 cm patches were dermabraded and dressed with carbon black and antibiotic ointment. After a healing period of eight weeks, pre-treatment biopsies were obtained, and the rabbits were treated with the Q- switched ruby laser at various fluence settings with a pulse width of 34 nsec. At set intervals, further biopsies were obtained and studied with light and electron microscopic analysis, and photodocumentation was performed. Grossly, clearance of the tattooed areas was noted in the laser treated specimens. More effective clearance was observed with higher fluence treatment. No infections occurred, and hair regrowth was noted in all cases, though the rate seemed to be altered by laser treatment.

  11. Efficacy of patterned scan laser in treatment of macular edema and retinal neovascularization

    Directory of Open Access Journals (Sweden)

    Dimple Modi

    2009-08-01

    Full Text Available Dimple Modi, Paulpoj Chiranand, Levent AkdumanSaint Louis University School of Medicine, Department of Ophthalmology, Saint Louis University Eye Institute, St. Louis, Missouri, USAPurpose: To analyze the benefits, efficacy, and complications of the PASCAL® photocoagulation laser system (OptiMedica, Santa Clara, CA, USA in patients treated at our institution.Methods: We conducted a retrospective chart review of 19 patients (28 eyes who underwent laser treatment using the PASCAL® photocoagulation system from November 2006 to November 2007. These 28 eyes were divided into two groups; group 1 eyes underwent macular grid laser and group 2 eyes underwent panretinal photocoagulation. Treatment was performed for macular edema or for iris or retinal neovascularization. Outcomes measured included best-corrected visual acuity (BCVA, efficacy of laser treatment, complications, duration of the procedure, and pain perception, which were noted in the charts for panretinal treatments.Results: Follow-up was 5.9 ± 2.6 months for group 1 and 5.9 ± 4.0 months for group 2. In group 1, 9/28 eyes required a second treatment for remaining edema. BCVA was stable or better in 66% (14/21 and average central foveal thickness on ocular coherence tomography improved in 71% (15/21. Time to completion for a number of laser patterns for grid photocoagulation was felt to be too long for completing the total pattern safely, although we have not noted any related complications. In group 2, the neovascularization regressed at least partially in 3/7 patients. Patient-reported pain perception was 3.6 on a scale of 1 to 10 for group 2. Occasional hemorrhages occurred secondary to irregular laser uptake at different spots in the patterns. We observed no visual outcome consequences because of these hemorrhages during follow-up.Conclusions: Retinal photocoagulation by the PASCAL® laser has comparable efficacy to historical results with conventional retinal photocoagulation in short

  12. Increase in Central Retinal Edema after Subthreshold Diode Micropulse Laser Treatment of Chronic Central Serous Chorioretinopathy

    Directory of Open Access Journals (Sweden)

    Maciej Gawęcki

    2015-01-01

    Full Text Available Purpose. Subthreshold diode micropulse laser (SDM treatment is believed to be safe method of treating clinical entities involving retinal edema. We present a case of serous edematous reaction of the retina to SDM treatment. Methods. Case report. Results. A patient with chronic central serous chorioretinopathy (CSCR was treated with SDM Yellow multispot laser. Procedure had been preceded by careful titration of the laser power, which after achieving of the threshold parameter was decreased by 50%. The follow-up visit two days after treatment revealed significant central retinal edema and subretinal fluid. Fundus autofluorescence image showed thermal reaction from the RPE in the form of small spots of hyperfluorescence corresponding to the laser multispot pattern used for treatment. Retinal edema resolved after topical bromfenac and single intravitreal bevacizumab injection. Slight pigmentary reaction from the RPE persisted. Conclusion. In the treatment of CSCR, there is a need to significantly reduce threshold SDM power parameters or simply use very low power without titration.

  13. Clinical research of retinal laser photocoagulation and Ranibizumab on the treatment of neovascular glaucoma

    Directory of Open Access Journals (Sweden)

    Wei-Peng Jiang

    2015-10-01

    Full Text Available AIM: To explore the improvement of visual function and the adverse reactions of retinal laser photocoagulation combined with ranibizumab for the treatment of neovascular glaucoma(NVG, to provide the basis for clinical treatment.METHODS: One hundred patients with 129 eyes in our hospital from January 2012 to June 2014 were selected. They were randomly divided into the observation group and the control group, 50 cases in each one. Patients in the control group(67 eyeswere treated with retinal laser photocoagulation, and those in the observation group(62 eyeswere given retinal laser photocoagulation combined with ranibizumab treatment. After the treatment, the degeneration of iris neovascularization, visual acuity, intraocular pressure, ocular fundus and the adverse reactions were evaluated. Optical coherence tomography(OCTwas used to detect retinal nerve fiber layer(RNFLthickness and visual field defect. RESULTS: The degeneration rate of the iris neovascularization in the observation group was 95.2%(59/62, higher than that of the control group 83.6%(56/67(PPPPPP>0.05.CONCLUSION: The treatment of NVG with laser photocoagulation combined with ranibizumab has good clinical efficacy, and can significantly improve the vision and retinal structure and function of the patients, and is safer.

  14. Treatment of striae distensae with needling therapy versus CO2 fractional laser.

    Science.gov (United States)

    Khater, Mohamed H; Khattab, Fathia M; Abdelhaleem, Manal R

    2016-01-01

    Striae are atrophic dermal scars with overlying epidermal atrophy causing cosmetic concern. This study assesses and compares the efficacy and safety of needling therapy versus CO2 fractional laser in treatment of striae. Twenty Egyptian female patients with striae in the abdomen and lower limbs were involved in the study. The patients were treated with needling therapy and CO2 laser every 1 month for 3 sessions. Follow-up by digital photography and skin biopsy was conducted at baseline and 6 months after treatment. Clinical improvement was assessed by comparing photographs and patient's satisfaction before and after treatment. Nine of 10 (90%) needle-treated patients showed improvement. Among them, 3 (30%) had good, 4 (40%) had fair, and 2 (20%) had poor improvements; however, 1 (10%) did not show any improvement after the treatment. In CO2-laser treated patients, 5 of 10 (50%) of the patients showed clinical improvement; 1 (10%) were good, 3 (30%) were fair, and 1 (10%) were poor; however, 5 (50%) did not show improvement. The results support the use of microneedle therapy over CO2 lasers for striae treatment.

  15. Treatment of burning mouth syndrome with a low-level energy diode laser.

    Science.gov (United States)

    Yang, Hui-Wen; Huang, Yu-Feng

    2011-02-01

    To test the therapeutic efficacy of low-level energy diode laser on burning mouth syndrome. Burning mouth syndrome is characterized by burning and painful sensations in the mouth, especially the tongue, in the absence of significant mucosal abnormalities. Although burning mouth syndrome is relatively common, little is known regarding its etiology and pathophysiology. As a result, no treatment is effective in all patients. Low-level energy diode laser therapy has been used in a variety of chronic and acute pain conditions, including neck, back and myofascial pain, degenerative osteoarthritis, and headache. A total of 17 patients who had been diagnosed with burning mouth syndrome were treated with an 800-nm wavelength diode laser. A straight handpiece was used with an end of 1-cm diameter with the fiber end standing 4 cm away from the end of handpiece. When the laser was applied, the handpiece directly contacted or was immediately above the symptomatic lingual surface. The output used was 3 W, 50 msec intermittent pulsing, and a frequency of 10 Hz, which was equivalent to an average power of 1.5 W/cm(2) (3 W × 0.05 msec × 10 Hz = 1.5 W/cm(2)). Depending on the involved area, laser was applied to a 1-cm(2) area for 70 sec until all involved area was covered. Overall pain and discomfort were analyzed with a 10-cm visual analogue scale. All patients received diode laser therapy between one and seven times. The average pain score before the treatment was 6.7 (ranging from 2.9 to 9.8). The results showed an average reduction in pain of 47.6% (ranging from 9.3% to 91.8%). The burning sensation remained unchanged for up to 12 months. Low-level energy diode laser may be an effective treatment for burning mouth syndrome.

  16. Hypopigmentation Induced by Frequent Low-Fluence, Large-Spot-Size QS Nd:YAG Laser Treatments.

    Science.gov (United States)

    Wong, Yisheng; Lee, Siong See Joyce; Goh, Chee Leok

    2015-12-01

    The Q-switched 1064-nm neodymium-doped yttrium aluminum garnet (QS 1064-nm Nd:YAG) laser is increasingly used for nonablative skin rejuvenation or "laser toning" for melasma. Multiple and frequent low-fluence, large-spot-size treatments are used to achieve laser toning, and these treatments are associated with the development of macular hypopigmentation as a complication. We present a case series of three patients who developed guttate hypomelanotic macules on the face after receiving laser toning treatment with QS 1064-nm Nd:YAG.

  17. Effects of heat treatments on laser welded Mg-rare earth alloy NZ30K

    International Nuclear Information System (INIS)

    Dai Jun; Huang Jian; Li Min; Li Zhuguo; Dong Jie; Wu Yixiong

    2011-01-01

    Highlights: → Firstly find the tadpole-shape precipitates in the welding joint. → The precipitation strengthening can account for 79% of the total strength. → The results can provide some insights on the application of Mg-RE alloy. - Abstract: In this study, the effects of heat treatments on the quality of laser welded Mg-rare earth alloy NZ30K were systematically studied. The microstructure and mechanical properties of joints, welded by a 15 kW high power CO 2 laser, under different heat treatments had been tested and analyzed. The results indicated that the heat treatment plays an important role in the mechanical strength of laser welded joint of NZ30K. The microstructure of samples after the solution treatment as well as aging treatment is different from that of the as-received welded joint. For solution treatment, although the microstructure is much different from that of as-received welded joint, the solution strengthening effect is not obvious. There are lots of precipitates in the fusion zone after the aging treatment, which will significantly enhance the ultimate tensile strength (UTS) and the yield tensile strength (YTS) of the welding joint. 79% of YTS is caused by precipitation strengthening. Therefore, the results implied that the UTS and YTS can be greatly improved by proper heat treatment.

  18. Long-term results of carbon dioxide laser treatment of meatal condylomata acuminata

    DEFF Research Database (Denmark)

    Krogh, J; Beuke, H P; Miskowiak, J

    1990-01-01

    A group of 74 men who underwent carbon dioxide laser treatment of meatal condylomata were observed for an average of 18 months. The cure rate after 1 treatment of isolated meatal lesions was 78%; the presence of external lesions lowered the rate to 32% and additional external and urethral warts...... to 25%. Following multiple treatments all but 6 patients were cured; 83% of the recurrences developed within 3 months. One urethral and 6 meatal strictures occurred more than 3 months after treatment; 9 patients had a spraying stream many years after treatment and 2 complained of frequency....

  19. The Successful Treatment of Elephantiasis Nostras Verrucosa With Ablative Carbon Dioxide Laser.

    Science.gov (United States)

    Robinson, Caitlin G; Lee, Kory R; Thomas, Valencia D

    2018-03-01

    Elephantiasis nostras verrucosa (ENV) is a disfiguring skin condition that is difficult to treat. Existing treatment modalities serve to improve cosmesis or treat symptoms. Herein, we report a case of ENV with lymphocutaneous fistula successfully treated with ablative carbon dioxide laser. A 57-year-old woman with biopsy-proven ENV with lymphocutaneous fistula was treated with ablative carbon dioxide laser to the symptomatic area of her right thigh in 3 treatment sessions over 6 months. The patient had resolution of lymphocutaneous drainage as well as 90% improvement in the appearance of ENV lesions at the 1-month follow-up visit. Ablative carbon dioxide laser may provide cosmetic, symptomatic, and medical benefit for patients with localized ENV.

  20. Histological study of subcutaneous fat at NIR laser treatment of the rat skin in vivo

    Science.gov (United States)

    Yanina, I. Y.; Svenskaya, Yu. I.; Navolokin, N. A.; Matveeva, O. V.; Bucharskaya, A. B.; Maslyakova, G. N.; Gorin, D. A.; Sukhorukov, G. B.; Tuchin, V. V.

    2015-07-01

    The goal of this work is to quantify impact of in vivo photochemical treatment using indocyanine green (ICG) or encapsulated ICG and NIR laser irradiation through skin of rat with obesity by the follow up tissue sampling and histochemistry. After 1 hour elapsed since 1-min light exposure samples of rat skin with subcutaneous tissue of thickness of 1.5-2.5 mm were taken by surgery from rats within marked 4-zones of the skin site. For hematoxylin-eosin histological examination of excised tissue samples, fixation was carried out by 10%-formaldehyde solution. For ICG and encapsulated ICG subcutaneous injection and subsequent 1-min diode laser irradiation with power density of 8 W/cm2, different necrotic regions with lipolysis of subcutaneous fat were observed. The obtained data can be used for safe layer-by-layer laser treatment of obesity and cellulite.

  1. Enhancement of the Laser Transmission Weldability between Polyethylene and Polyoxymethylene by Plasma Surface Treatment

    Directory of Open Access Journals (Sweden)

    Huixia Liu

    2017-12-01

    Full Text Available Due to their large compatibility difference, polyethylene (PE and polyoxymethylene (POM cannot be welded together by laser transmission welding. In this study, PE and POM are pretreated using plasma that significantly enhances their laser transmission welding strength. To understand the mechanism underlying the laser welding strength enhancement, surface modification is analyzed using contact angle measurements, atomic force microscopy (AFM, optical microscopy, and X-ray photoelectron spectroscopy (XPS. Characterization results show that the plasma surface treatment improves the surface free energy, significantly enhancing the wettability of the materials. The increase in surface roughness and the generation of homogeneous bubbles contribute to the formation of mechanical micro-interlocking. The oxygen-containing groups introduced by the oxygen plasma treatment improve the compatibility of PE and POM, and facilitate the diffusion and entanglement of molecular chains and the formation of van der Waals force.

  2. Bacteriophage amplification assay for detection of Listeria spp. using virucidal laser treatment

    Directory of Open Access Journals (Sweden)

    I.C. Oliveira

    2012-09-01

    Full Text Available A protocol for the bacteriophage amplification technique was developed for quantitative detection of viable Listeria monocytogenes cells using the A511 listeriophage with plaque formation as the end-point assay. Laser and toluidine blue O (TBO were employed as selective virucidal treatment for destruction of exogenous bacteriophage. Laser and TBO can bring a total reduction in titer phage (ca. 10(8 pfu/mL without affecting the viability of L. monocytogenes cells. Artificially inoculated skimmed milk revealed mean populations of the bacteria as low as between 13 cfu/mL (1.11 log cfu/mL, after a 10-h assay duration. Virucidal laser treatment demonstrated better protection of Listeria cells than the other agents previously tested. The protocol was faster and easier to perform than standard procedures. This protocol constitutes an alternative for rapid, sensitive and quantitative detection of L. monocytogenes.

  3. Non-ablative fractionated laser skin resurfacing for the treatment of aged neck skin.

    Science.gov (United States)

    Bencini, Pier Luca; Tourlaki, Athanasia; Galimberti, Michela; Pellacani, Giovanni

    2015-06-01

    Aging of the neck skin includes poikiloderma of Civatte, skin laxity and wrinkles. While the vascular alterations of poikiloderma of Civatte can be effectively treated with lasers or intense pulsed light, a successful treatment of dyschromia, skin laxity and wrinkles is still difficult to achieve. To evaluate the safety and efficacy of non-ablative fractional 1540 erbium glass laser for the treatment of aged neck skin, also by means of in vivo reflectance confocal microscopy (RCM). A prospective study for neck resurfacing in 18 women with aged neck skin. Six laser treatments were performed in 4-week intervals with a 1540-nm erbium-glass fiber laser. By using a 6-point grading scale, the mean score (±SD; range) at baseline was 3.6 (±1.5; 1-6) for skin dyschromia, 2.9 (±1.4; 1-6) for laxity and 3.3 (±1.3; 1-5) for wrinkles. Three months after the last laser session, we found a significant clinical improvement of dyschromia (p = 0.0002; Wilcoxon test), and wrinkles (p = 0.0004; Wilcoxon test), with a mean (±SD) reduction of 2.5 (±1.0) and 1.9 (±1.1) points in the 6-point grading scale, respectively. No change was observed in laxity. These results were also supported by structural changes documented by RCM. Non-ablative fractional 1540 erbium glass laser was both safe and effective for the treatment of dyschromia and wrinkles, but not effective for the laxity of the neck skin.

  4. Laser (755 nm) and cryotherapy as depigmentation treatments for vitiligo: a comparative study.

    Science.gov (United States)

    van Geel, N; Depaepe, L; Speeckaert, R

    2015-06-01

    Depigmentation therapy can be an option in adults with extensive and refractory vitiligo. Remaining pigmented patches can be removed using depigmentation creams (monobenzyl ether of hydroquinone 20%), laser therapy or cryotherapy. In contrast to cream treatment, laser therapy and cryotherapy are fast and targeted methods, capable of destroying melanocytes selectively on one specific area. Up till now, controlled trials comparing laser and cryotherapy as depigmenting treatment in vitiligo are lacking. We performed a retrospective comparative study in 22 generalized vitiligo patients. Thirty-one pigmented test regions were exposed to cryotherapy and 20 to 755 nm laser therapy. The mean surface area per test region was 3.55 cm2 and number of treatments per test region was limited to one single session in 84.3% and varied up to four sessions (2.0%). Overall no significant difference in the capacity to induce depigmentations was observed between cryotherapy (46.7%) and laser therapy (42.9%) after one treatment. The percentage of induced depigmentation was significantly different according to the body location (P = 0.005) with best results on the trunk, followed by the arms, face, neck and less on the hands. Variables that positively influenced depigmentation results were a younger age of vitiligo onset (P = 0.012), skin type V (P cryotherapy and concerned mainly hyperpigmentation in the face. To our knowledge, this is the first study comparing head-to-head depigmentation strategies intra- and inter-individually. We could demonstrate that in general laser and cryotherapy are equally effective in inducing depigmentations in generalized vitiligo patients. Retreatment of the same area may be required in case of initial failure. © 2014 European Academy of Dermatology and Venereology.

  5. Treatment of recurrent aphthous stomatitis by laser therapy: A systematic review of the literature

    Directory of Open Access Journals (Sweden)

    Pavlić Verica

    2015-01-01

    Full Text Available Background/Aim. Recurrent aphthous stomatitis (RAS is defined as multifactor immunologic inflammatory lesions in the oral cavity, characterized by painful, recurrent single/multiple, shallow, round or ovoid ulcerations of mucosal tissues. To date, a considerable number of RAS treatment protocols have been suggested, but since the etiology of RAS is idiopathic, these treatment options have symptomatic rather than curative or preventive effect. Recently, it has been suggested that laser therapy could be successfully used as an efficient treatment approach in therapy of RAS. Therefore, the aim of this review was to estimate the effects of laser therapy in treatment of RAS analyzing results of clinical studies published in peer reviewed journals. Methods. The studies published until 31 December 2013 were obtained from the Medline/PubMed, Science Direct and Cochrane Library of the Cochrane Collaboration (CENTRAL online databases, using following search terms and key words: “laser” AND “recurrent aphthous stomatitis”, “laser” AND “aphthous”, and “laser” AND “aphthae”. In total 4 original research articles met the all required inclusion/exclusion criteria, and were used for this review. The main outcome measures assessed were: a reduction of pain associated with RAS and a reduction in episode duration (faster RAS healing. Results. The assessed literature demonstrates the benefits of laser therapy mainly due to immediate analgesia and ability to speed up a RAS healing process. Conclusion. Even though the assessed literature suggests beneficial outcomes of laser therapy in treatment of RAS, these results should be interpreted with caution. The issues related to the study designs and different sets of laser irradiation parameters of a limited number of available studies with the same treatment outcomes prevent us from making definite conclusions.

  6. Lasers in Ophthalmology

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    In recent years,lasers have entered every fieldof medicine and especially so in ophthalmol-ogy.The scientific basis of lasers in ophthal-mology is based on three mechanisms:1.Photothermal effectLasers:argon,krypton,dye and diodeA thermal effect is generated when laserenergy is absorbed by pigment leading to in-creased vibration and therefore heat content.A

  7. [Treatment of small and sublingual salivary glands cysts by laser].

    Science.gov (United States)

    Bogatov, V V; Vybornov, V V; Malinovskiĭ, I Iu

    2011-01-01

    The differents variants of treatment of retention cysts of mucous membrane of oral cavity and sublingual salivary gland cysts were presented and analysed. Results of doppler examination as a method of research blood microcirculation in postoperation time were presented.

  8. Insufficient scientific evidence for efficacy of widely used electrotherapy, laser therapy, and ultrasound treatment in physiotherapy

    NARCIS (Netherlands)

    Bouter, L M

    2000-01-01

    The Dutch Health Council recently published a report on the efficacy of electrotherapy, laser therapy and ultrasound treatment for musculoskeletal disorders. The assessment was based on three systematic reviews, including 169 randomized clinical trials, and focused on a best-evidence synthesis.

  9. Endoscopic treatment of pharyngeal pouches: electrocoagulation vs carbon dioxide (CO2) laser

    NARCIS (Netherlands)

    Flikweert, D. C.; van der Baan, S.

    1992-01-01

    Endoscopic treatment of a hypopharyngeal diverticulum was performed in 75 patients during the period 1976-1990. Initially electrocoagulation was used to divide the septum between the diverticulum and oesophagus. More recently, the CO2 laser combined with the operating microscope has been used.

  10. Laser ablation of a biliary duct for treatment of a persistent biliary-cutaneous fistula.

    Science.gov (United States)

    Eicher, Chad A; Adelson, Anthony B; Himmelberg, Jeffrey A; Chintalapudi, Udaya

    2008-02-01

    A persistent biliary-cutaneous fistula detected after biliary drainage catheter removal could not be resolved with diversionary techniques and Gelfoam and fibrin glue administration in the fistulous tract. As an alternative approach for treatment of the fistula, obliteration of the contributing bile duct with laser ablation was performed.

  11. Successful Treatment of Stent Knot in the Proximal Ureter Using Ureteroscopy and Holmium Laser

    Directory of Open Access Journals (Sweden)

    Masters M. Richards

    2011-01-01

    Full Text Available Knotted ureteral stent is rare yet tedious complication that might represent a treatment challenge to the endourologist. Only twelve cases of knotted stent have been reported. Different management options have been reported, including simple traction, ureteroscopy, percutaneous removal, and open surgery. In this paper, we present the successful untying of the knot using ureteroscopy with holmium laser.

  12. Redarkening of port-wine stains 10 years after pulsed-dye-laser treatment

    NARCIS (Netherlands)

    Huikeshoven, Menno; Koster, Petra H. L.; de Borgie, Corianne A. J. M.; Beek, Johan F.; van Gemert, Martin J. C.; van der Horst, Chantal M. A. M.

    2007-01-01

    BACKGROUND: Although pulsed-dye-laser therapy is currently the gold standard for the treatment of port-wine stains, few objective data are available on its long-term efficacy. Using objective color measurements, we performed a 10-year follow-up of a previously conducted prospective clinical study of

  13. Surface properties tuning of welding electrode-deposited hardfacings by laser heat treatment

    Science.gov (United States)

    Oláh, Arthur; Croitoru, Catalin; Tierean, Mircea Horia

    2018-04-01

    In this paper, several Cr-Mn-rich hardfacings have been open-arc deposited on S275JR carbon quality structural steel and further submitted to laser treatment at different powers. An overall increase with 34-98% in the average microhardness and wear resistance of the coatings has been obtained, due to the formation of martensite, silicides, as well as simple and complex carbides on the surface of the hardfacings, in comparison with the reference, not submitted to laser thermal treatment. Surface laser treatment of electrode-deposited hardfacings improves their chemical resistance under corrosive saline environments, as determined by the 43% lower amount of leached iron and respectively, 28% lower amount of manganese ions leached in a 10% wt. NaCl aqueous solution, comparing with the reference hardfacings. Laser heat treatment also promotes better compatibility of the hardfacings with water-based paints and oil-based paints and primers, through the relative increasing in the polar component of the surface energy (with up to 65%) which aids both water and filler spreading on the metallic surface.

  14. Laser Therapy in the Treatment of Paresthesia: A Retrospective Study of 125 Clinical Cases.

    Science.gov (United States)

    de Oliveira, Renata Ferreira; da Silva, Alessandro Costa; Simões, Alyne; Youssef, Michel Nicolau; de Freitas, Patrícia Moreira

    2015-08-01

    The aim of this retrospective study was to evaluate the effectiveness of laser therapy for acceleration and recovery of nerve sensitivity after orthognathic or minor oral surgeries, by analysis of clinical records of patients treated at the Special Laboratory of Lasers in Dentistry (LELO, School of Dentistry, University of São Paulo), throughout the period 2007-2013. Nerve tissue lesions may occur during various dental and routine surgical procedures, resulting in paresthesia. Laser therapy has been shown to be able to accelerate and enhance the regeneration of the affected nerve tissue; however, there are few studies in the literature that evaluate the effects of treatment with low-power laser on neural changes after orthognathic or minor oral surgeries. A total of 125 clinical records were included, and the data on gender, age, origin of the lesion, nerve, interval between surgery and onset of laser therapy, frequency of laser irradiation (one or two times per week), final evolution, and if there was a need to change the irradiation protocol, were all recorded. These data were related to the recovery of sensitivity in the affected nerve area. Descriptive analyses and modeling for analysis of categorical data (α=5%) were performed. The results from both analyses showed that the recovery of sensitivity was correlated with patient age (p=0.015) and interval between surgery and onset of laser therapy (p=0.002). Within the limits of this retrospective study, it was found that low- power laser therapy with beam emission band in the infrared spectrum (808 nm) can positively affect the recovery of sensitivity after orthognathic or minor oral surgeries.

  15. Effect of infrared laser in the prevention and treatment of paresthesia in orthognathic surgery.

    Science.gov (United States)

    Prazeres, Lady Dayane Kalline Travassos; Muniz, Yuri Victor Siqueira; Barros, Keylla Marinho Albuquerque; Gerbi, Marleny Elizabeth Marquez de Martinez; Laureano Filho, José Rodrigues

    2013-05-01

    Orthognathic surgery is the surgical procedure that makes correcting deformities of the bones in the region of the maxilla and mandible a reality in the Brazilian dentistry. However, this type of surgery usually involves paresthesia in the postoperative period, concerning the surgeons who perform them and generating discomfort to patients. This study aimed at evaluating the effect of infrared laser (830 nm) in the prevention and treatment of paresthesias after orthognathic surgery. Six patients underwent orthognathic surgery: the experimental group composed of 4 patients and the control group that did not receive laser therapy composed of 2 patients. The experimental group received laser applications during the transoperative and 12 postoperative sessions. Tests for mechanical (deep and shallow) and thermal (cold) sensitivity were performed in the preoperative and postoperative period (during 12 sessions) in the lip and chin areas by the same operator. The paresthesia was classified into 1, strong; 2, moderate; 3, mild; and 4, absent, through the patient's response to stimuli. The results showed that all patients had no disturbance of sensitivity in the preoperative period, but paresthesia was presented at various levels in the postoperative period. Both groups showed recovery of deep mechanical sensitivity within a shorter time interval compared with the superficial mechanical and thermal sensitivity. However, at the 12th assessment, patients who underwent the laser therapy showed better reduction in the level of paresthesia or even complete regression of this. The laser, therefore, brought benefits to the treatment of paresthesia, accelerating the return of neurosensorial sensitivity.

  16. Shock velocity in weakly ionized nitrogen, air, and argon

    International Nuclear Information System (INIS)

    Siefert, Nicholas S.

    2007-01-01

    The goal of this research was to determine the principal mechanism(s) for the shock velocity increase in weakly ionized gases. This paper reports experimental data on the propagation of spark-generated shock waves (1< Mach<3) into weakly ionized nitrogen, air, and argon glow discharges (1 < p<20 Torr). In order to distinguish between effects due solely to the presence of electrons and effects due to heating of the background gas via elastic collisions with electrons, the weakly ionized discharge was pulsed on/off. Laser deflection methods determined the shock velocity, and the electron number density was collected using a microwave hairpin resonator. In the afterglow of nitrogen, air, and argon discharges, the shock velocity first decreased, not at the characteristic time for electrons to diffuse to the walls, but rather at the characteristic time for the centerline gas temperature to equilibrate with the wall temperature. These data support the conclusion that the principal mechanism for the increase in shock velocity in weakly ionized gases is thermal heating of the neutral gas species via elastic collisions with electrons

  17. [What is the value of low-energie lasers in the treatment of androgenetic alopecia ?

    Science.gov (United States)

    Paquet, Ph; Orduz, M; Franchimont, C; Nikkels, A F

    2017-12-01

    Male and female androgenetic alopecia is a common, chronic, psychologically stressful disorder affecting more than 50 % of the individuals by 50 years of age. Despite the current topical (minoxidil) or oral (the inhibitors of 5-? reductase finasteride or dutasteride) treatments, there is a need for more effective management options. The current clinical evidence, the possible mechanisms of action and the rare adverse events of the low level laser therapy in the treatment of androgenetic alopecia are presented.

  18. Treatment of tattoos with a 755-nm Q-switched alexandrite laser and novel 1064 nm and 532 nm Nd:YAG laser handpieces pumped by the alexandrite treatment beam.

    Science.gov (United States)

    Bernstein, Eric F; Bhawalkar, Jay; Clifford, Joan; Hsia, James

    2010-11-01

    Multi-colored and even black tattoos often require more than one wavelength to remove the target pigment. The authors report here a novel alexandrite laser with two Nd:YAG laser handpieces pumped by the alexandrite treatment beam enabling the delivery of three wavelengths from a single device. To describe and evaluate the effectiveness of a novel Q-switched laser-pumped laser for treating tattoos. Twenty tattoos in 14 subjects were treated at four-week intervals using a combination of available wavelengths (532, 755 and 1064 nm) as determined by the treating physician. Digital cross-polarized photographs were taken before treatment and two months following the fourth and final treatment. Photographs were evaluated by three physician observers blinded as to the treatment condition and rated for clearance by the following scale: 1 = > 95 percent, 2 = 76-95 percent, 3 = 51-75 percent, 4 = 26-50 percent and 5 = 0-25 percent clearance. The average clearance score was 3.1, in the 51-75 percent range, two months following four treatments. No scarring, hyper- or hypopigmentation was noted on post-treatment photographs or by the treating physician. The alexandrite and alexandrite-pumped 532 nm and 1064 nm Q-switched lasers are effective for removing decorative tattoos, and represents the first commercial laser with laser-pumped, laser handpieces.

  19. Endoscopic Nd-YAG laser treatment and adjuvant therapy for metastatic lesions of airway

    Energy Technology Data Exchange (ETDEWEB)

    Okitsu, Hiroshi; Oho, Kenkichi; Naitoh, Jun; Tajika, Eishiro; Amemiya, Ryuta; Hayata, Yoshihiro [Tokyo Medical Coll. (Japan)

    1989-06-01

    Endoscopic Nd-YAG laser treatment and adjuvant therapy were performed in 44 cases with metastatic lesions of airway. The best results were obtained in 31 cases (93.9%) out of 33 cases complaining of ventilatory disturbance in which endoscopic Nd-YAG laser treatment was indicated as an emergency procedure. In most of these cases with metastatic lesions of airway consisted of respiratory tract invasion from mediastinal lymph nodes in cases of esophageal cancer or lung cancer. In these cases, after laser treatment for ventilatory disturbance, the patients condition improved to the extent that adjuvant therapy could be performed. Adjuvant therapy was performed in 38 cases, there were 7 cases treated surgically resection of the metastatic lesions of airway in 3 cases, tracheal tube stent operation in 4 cases 0, 28 radiotherapy in 28 cases Linac irradiation in 24 cases, /sup 60/Co intraluminal irradiation of the trachea in 4 cases 0, and 32 cases were treated with chemotherapy. Tracheal tube stent operation was useful for maintenance of the tracheal lumen following laser treatment, and /sup 60/Co intraluminal irradiation was effective for the residual intratracheal tumor. The 1-year survival rate of 44 cases with metastatic lesions of airway was 42% and the 2-year survival rate was 22%, so this result suggested endoscopic Nd-YAG laser treatment and adjuvant therapy for metastatic lesions of airway was useful to prolong survival time. However the main value of this modality is for the rapid relief of severe ventilatory disturbance due to obstructive airway lesions. (author).

  20. Puncture laser microdiscectomy in treatment of large lumbar spinal hernias

    Directory of Open Access Journals (Sweden)

    Zorin M.M.

    2013-06-01

    Full Text Available Degree of hernia size influence on final result of PLME in 34 patients with discogenic neurocompressive lumbar spinal syndrome was detected. In medical center "Endoscopic Neurosurgery" from 2006 to 2010 we examined and treated 34 patients with hernia size from 6 to 8 mm by CT data. Patients were from 19 to 49 years of age. Average age was 35.9 ± 1.5 years. Males – 16 (47.1%, females – 18 (52.9%. Disease duration – 5.53 ± 0.44 months with duration of last exacerbation – 1.87 ± 0.21 months. Duration of conservative therapy is 4.6 ± 2.1 weeks. During survey and objec¬tive examination we determined pain syndrome intensity, pain location, degree of spinal static – dynamic function disorder. Neurological examination determined severity of sensory and motor disorders. Pain syndrome intensity, quality of life in patients before and after surgery, surgery effectiveness were determined by common scales: VAS, OSWESTRY, Roland - Morris, McNab. Before PLME we evaluated preoperative spondylograms performed with functional load. Height of intervertebral fissure was determined by these images. By SCT and MRI data we measured hernia size, its shape and location as well as intervertebral disk dehydration degree. For PLME performance we used neodymium laser with aluminum garnet (Dorinyer Fibertom Medilas 4060 with wave-length of 1.06 micrometers. In the next period of observation after PLME its effectiveness was 79%, and in 3-5 years - 76%. At the same time it must be emphasized that 75% of patients with discogenic neurocompressive lumbar spinal syndrome significantly and for a long time improved their life quality avoiding more traumatic surgery. Satisfactory results with PLM use in the nearest future could be obtained in 79% of patients, in the remote term - in 76% of patients with large hernia size.

  1. Comparison of photosensitivity in germanium doped silica fibers using 244 nm and 266 nm continuous wave lasers

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo; Varming, Poul; Liu, B.

    2001-01-01

    Diode pumped continuous-wave UV lasers offer an interesting alternative to frequency doubled argon-ion lasers. We report the first photosensitivity comparison using these lasers on deuterium loaded standard telecommunication fibers and unloaded experimental fibers....

  2. Research Thinking of Low-intensity laser For the Treatment of Menopausal Syndrome

    International Nuclear Information System (INIS)

    Chen, G Z; Wang, X Y; Xu, Y X; Li, L J; Liu, S H

    2011-01-01

    Female climacteric syndrome is a clinical syndrome due to autonomic nerve dysfunction occurring in women during climacteric period, which may affect their physical and mental health. Therefore, how to pass climacteric period for women without any problems, avoid or reduce the occurrence of climacteric syndrome, prevent geriatric diseases and improve life quality is a key issue now for great attention. Looking for a convenient, effective, and safer method without toxic-side effects to control the disease is a modern medical problem. By analyzing the relationship between laser technology and traditional acupuncture and moxibustion, the advantage and the existing problems on acupuncture and moxibustion for the treatment of menopausal syndrome, the application of laser methods for the mechanism research on TCM diagnosis and treatment of menopausal syndrome was discussed. It's pointed out that the laser acupuncture is safe and effective to treat menopausal syndrome. Breakthrough will be achieved from the research of the selection of the acupoint prescription and mechanism of Acupuncture and Moxibustion for the treatment of menopausal syndrome by utilizing the advantage of interdisciplinary intersection. Laser technology will make the development of acupuncture and moxibustion science possess an unprecedented field.

  3. Research Thinking of Low-intensity laser For the Treatment of Menopausal Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Chen, G Z; Wang, X Y [Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, 510405 (China); Xu, Y X; Li, L J [Acupuncture and Massage College, Guangzhou University of Chinese Medicine, Guangzhou, 510405 (China); Liu, S H, E-mail: xuyx1968@163.com [South China Normal University, Guangzhou, 510631 (China)

    2011-02-01

    Female climacteric syndrome is a clinical syndrome due to autonomic nerve dysfunction occurring in women during climacteric period, which may affect their physical and mental health. Therefore, how to pass climacteric period for women without any problems, avoid or reduce the occurrence of climacteric syndrome, prevent geriatric diseases and improve life quality is a key issue now for great attention. Looking for a convenient, effective, and safer method without toxic-side effects to control the disease is a modern medical problem. By analyzing the relationship between laser technology and traditional acupuncture and moxibustion, the advantage and the existing problems on acupuncture and moxibustion for the treatment of menopausal syndrome, the application of laser methods for the mechanism research on TCM diagnosis and treatment of menopausal syndrome was discussed. It's pointed out that the laser acupuncture is safe and effective to treat menopausal syndrome. Breakthrough will be achieved from the research of the selection of the acupoint prescription and mechanism of Acupuncture and Moxibustion for the treatment of menopausal syndrome by utilizing the advantage of interdisciplinary intersection. Laser technology will make the development of acupuncture and moxibustion science possess an unprecedented field.

  4. Effective of diode laser on teeth enamel in the teeth whitening treatment

    Science.gov (United States)

    Klunboot, U.; Arayathanitkul, K.; Chitaree, R.; Emarat, N.

    2011-12-01

    This research purpose is to investigate the changing of teeth color and to study the surface of teeth after treatment by laser diode at different power densities for tooth whitening treatment. In the experiment, human-extracted teeth samples were divided into 7 groups of 6 teeth each. After that laser diode was irradiated to teeth, which were coated by 38% concentration of hydrogen peroxide, during for 20, 30 and 60 seconds at power densities of 10.9 and 52.1 W/cm2. The results of teeth color change were described by the CIEL*a*b* systems and the damage of teeth surface were investigated by scanning electron microscopy (SEM). The results showed that the power density of the laser diode could affect the whiteness of teeth. The high power density caused more luminous teeth than the low power density did, but on the other hand the high power density also caused damage to the teeth surface. Therefore, the laser diode at the low power densities has high efficiency for tooth whitening treatment and it has a potential for other clinical applications.

  5. The effects of photodynamic laser therapy in the treatment of marginal chronic periodontitis

    Science.gov (United States)

    Chifor, Radu; Badea, Iulia; Avram, Ramona; Chifor, Ioana; Badea, Mîndra Eugenia

    2016-03-01

    The aim of this study was to assess the effects of the antimicrobial photodynamic laser therapy performed during the treatment of deep periodontal disease by using 40 MHz high frequency ultrasonography. The periodontal data recorded during the clinical examination before each treatment session were compared with volumetric changes of the gingiva measured on periodontal ultrasound images. The results show a significant decrease of gingival tissue inflammation proved both by a significant decrease of bleeding on probing as well as by a decrease of the gingival tissues volume on sites where the laser therapy was performed. Periodontal tissues that benefit of laser therapy besides classical non-surgical treatment showed a significant clinical improvement of periodontal status. Based on these findings we were able to conclude that the antimicrobial photodynamic laser therapy applied on marginal periodontium has important anti-inflamatory effect. The periodontal ultrasonography is a method which can provide useful data for assessing the volume changes of gingival tissues, allowing a precise monitoring of marginal periodontitis.

  6. Retinal screening acceptance, laser treatment uptake and follow-up response in diabetics requiring laser therapy in an urban diabetes care centre

    International Nuclear Information System (INIS)

    Memon, S.

    2015-01-01

    To determine the acceptance of retinal screening, Laser uptake and subsequent follow-up in diabetic patients attending the Diabetes Centre of Diabetic Association of Pakistan (DAP), Karachi. Study Design: Observational case series. Place and Duration of Study: Diabetic Centre of Diabetic Association of Pakistan (DAP), Karachi, from January 2011 to December 2012. Methodology: All the diabetic patients were screened for Diabetic Retinopathy (DR) with non-Mydriatic Fundus Camera (NMFC). Patients with DR were examined by the ophthalmologist using fundus lens and slit lamp. DR was graded for severity on the basis of modified Airlie House Classification. Patients with Sight Threatening Diabetic Retinopathy (STDR) were advised Laser treatment. Each patient was followed-up for at least 6 months. The records of patients recommended Laser were retrieved, and called for re-examination. Results: Retinal screening was accepted by all of the 8368 registered diabetics attending DAP Centre. On fundus photography, 21.2% (1777) individuals were found to have DR. Seven hundred and five (39.5%) patients were found to have STDR. Laser was advised to 96.4% (680) of STDR patients; amongst whom 70.5% (480) accepted Laser treatment. Out of 480 patients who had Laser treatment, 21.2% (107) turned out for follow-up after 6 months. Conclusion: Acceptance of retinal screening and Laser application was good; but follow-up was suboptional. (author)

  7. Sodium evaporation into a forced argon flow

    International Nuclear Information System (INIS)

    Kumada, Toshiaki; Kasahara, Fumio; Ishiguro, Ryoji

    1975-01-01

    Evaporation from a rectangular sodium free surface into an argon flow was measured. Tests were carried out with varying sodium temperature, argon velocity and argon temperature respectively under conditions of fog formation being possible. In order to clarify the enhancement of evaporation by fog formation, convection heat transfer from a plate of the same geometry into an air flow was also measured. The evaporation rate and Sherwood number were compared with those predicted by both the heat transfer experiment and the theory proposed by Hill and Szekely, and also a comparison was run with the previously reported experimental results of sodium evaporation. As a result it was shown that the sodium evaporation rate in this experiment is at least four times as large as that predicted by the heat transfer experiment and varies almost linearly with the heat transfer rate and the sodium vapour pressure. (auth.)

  8. Cryogenic digital data links for the liquid argon time projection chamber

    International Nuclear Information System (INIS)

    Liu, T; Gong, D; Liu, C; Xiang, A C; Ye, J; Hou, S; Su, D-S; Teng, P-K

    2012-01-01

    In this paper we present the cryogenic functionality of the components of data links for the Liquid Argon Time Projection Chamber (LArTPC), a potential far site detector technology of the Long-Baseline Neutrino Experiment (LBNE). We have confirmed that an LVDS driver can drive a 20-meter CAT5E twisted pair up to 1 gigabit per second at the liquid nitrogen temperature (77 K). We have verified that a commercial-off-the-shelf (COTS) serializer, a laser diode driver, laser diodes, optical fibers and connectors, and field-programming gate arrays (FPGA's) continue to function at 77 K. A variety of COTS resistors and capacitors have been tested at 77 K. All tests we have conducted show that the cryogenic digital data links for the liquid argon time projection chamber are promising.

  9. Electron-ion recombination study in argon at atmospheric pressure

    International Nuclear Information System (INIS)

    Kafrouni, Hanna.

    1979-01-01

    This study deals with a wall-stabilized arc burning in argon at atmospheric pressure. A transient mode is obtained using a fast thyristor connected to the electrodes, which short-circuits the discharge. By means of two wavelengths laser interferometry and spectroscopy measurements we have determined the temporal changes of the electron density, ground state atom density and excited atom density. We have shown that, when the electric field is suppressed, the electron temperature rapidly decreases to the gas temperature before changing electron and atom densities. This phenomenon is applied to determine the gas temperature and to evaluate the role played by ionization in electron density balance. The coefficients of ambipolar diffusion, ionization and recombination and an apparent recombination coefficient are determined versus electron temperature and compared with theoretical values [fr

  10. [Physical treatment methods for acne. Light, laser, photodynamic therapy and peeling].

    Science.gov (United States)

    Borelli, C; Korting, H C

    2010-02-01

    The medical treatment of acne is generally sufficient to meet the expectations of acne patients. However, in a number of situations additional therapeutic approaches may be advisable. There are a wide variety of useful physical methods. They range from electromagnetic waves, usually light, to peeling and manual therapy. Phototherapy of acne includes not just visible light but also laser and flash lamp therapy. The present review provides an overview on the evidence. Visible light, in particular blue light, provides an effective option for treatment of inflammatory acne. Photodynamic therapy also is efficacious; however, it should not be used because of an unfavorable risk-benefit ratio. UV treatment of acne is obsolete. Newer studies on the use of a variety of laser systems and flash lamps have demonstrated in part rewarding results.

  11. Short-pulsed laser for the treatment of tattoos, pigmented lesions, scars and rejuvenation.

    Science.gov (United States)

    Tanghetti, Emil A; Hoffmann, Kristina Andrea; Hoffmann, Klaus

    2017-12-01

    This review describes the use of picosecond lasers for the treatment of tattoos, pigmented lesions, scars, and their use in rejuvenation. These devices have delivered enhanced efficacy for the treatment of tattoos and pigmented lesions when compared to the older 40-50 nanosecond devices. The fractional delivery with the picosecond devices have opened up a new method of rejuvenation for photodamaged skin and the treatment of scars. The delivery of these high-energy short pulses have created zones of injury in the skin referred to as areas of laser-induced optical breakdown. These areas of damage appear to produce cytokines and chemokines which result in epidermal and dermal repair and remodeling. The dual use of these devices with the flat and the fractional optics have made these devices useful in many ways that have been unanticipated. ©2017 Frontline Medical Communications.

  12. Argon isotopes as recorders of magmatic processes

    Science.gov (United States)

    Layer, P. W.; Gardner, J. E.; Mora Chaparro, J. C.; Arce, J. L.

    2003-12-01

    Argon isotopic ratios vary enough between different reservoirs (atmosphere, crust, mantle) and diffuse fast enough through most minerals at magmatic temperatures (700-1200 C) to make them ideal for looking at magma chamber dynamics. Indeed, diffusion is sufficiently fast to allow short time scales to be deciphered, setting argon apart from many other isotopic methods. A mineral's ability to retain "excess" argon (40Ar/36Ar ratios greater than the atmospheric value and apparent ages older than the known eruption age) during post-eruption cooling is key to Ar studies. Previous work shows that both phenocrysts (crystallizing in the magma chamber; e.g. Mt St. Helens; Layer and Gardner, 2001) and xenocrysts (introduced into the magma chamber; e.g Toba; Gardner et al., 2002) preserve excess argon, which enables magma chamber processes to be deciphered through the variable diffusion rates between crystal phases. Single crystal 40Ar/39Ar step-heating of biotite from the 10.5 ka eruption of Nevado de Toluca volcano, Mexico indicates that they are xenocrystic and resided for only a short (< 1 year) time in the magma before it erupted. The biotite has reaction rims of hornblende, orthopyroxene and plagioclase, and failed to grow experimentally at pressure-temperature conditions of the magma, confirming the xenocrystic nature of this phase. Single-step fusion of plagioclase phenocrysts from eruptions of El Chichon volcano, Mexico, shows evidence of excess (mantle) argon, whereas hornblende from the same eruptions contains little or none. In this case, faster diffusion of Ar in plagioclase than in hornblende allow plagioclase to incorporate excess argon during magma recharge; hornblende does not. Combining such results with other isotopic systems may in fact better determine magma chamber processes. At El Chichon, Sr isotopes suggest magma recharges ocurred (Tepley et al., 2000), whereas the argon isotopes suggest such pulses occurred just before each eruption. The fast and

  13. A pilot study of treatment of striae distensae with variable square pulse Erbium: YAG laser resurfacing.

    Science.gov (United States)

    Wanitphakdeedecha, Rungsima; Meeprathom, Walailak; Manuskiatti, Woraphong

    2017-12-01

    Striae distensae (SD) are a frequent skin condition for which treatment remains a challenge. Various laser treatments have been employed to remove the epidermis and cause dermal wound and heating with subsequent dermal collagen remodeling. To determine the efficacy and safety of a variable square pulse Erbium: YAG (VSP Er:YAG) laser for the treatment of striae in skin phototypes III-IV. Twenty-one women with SD were treated monthly for 2 months with VSP Er:YAG laser resurfacing using a 7-mm spot size. One side of their striae was randomly treated with one pass of 400 mJ in short pulse (SP) mode with 50% overlapping and one pass of 2.2 J/cm 2 in smooth (SM) mode with nonoverlapping. The other side of their striae was treated with two passes of 400 mJ in SP mode with 50% overlapping. Objective and subjective assessments were obtained at baseline and 1-, 3-, and 6-month after treatment. In both SP&SM and SP only group, volume of SD measured by Visioscan VC98 reduced significantly at 6-month follow-up visit (P=.017 and P=.034, respectively). There were no statistically significant differences in skin roughness (SER), skin smoothness (SESM), and surface measured by Visioscan VC98. Transient postinflammatory hyperpigmentation (PIH) is the common side effect found in patients with darker skin tone even in nonsun exposure areas and can last as long as 6 months. VSP Er:YAG laser resurfacing is a promising treatment option for SD. Lower fluence should be used in patients with darker skin phototype to avoid the risk of PIH. In addition, pre- and post-treatment with topical preparations for PIH prevention may be needed. © 2017 Wiley Periodicals, Inc.

  14. The measurement of argon metastable atoms in the barrier discharge plasma

    Science.gov (United States)

    Ghildina, Anna R.; Mikheyev, Pavel Anatolyevich; Chernyshov, Aleksandr Konstantinovich; Lunev, Nikolai Nikolaevich; Azyazov, Valeriy Nikolaevich

    2018-04-01

    The mandatory condition for efficient operation of an optically-pumped all-rare-gas laser (OPRGL) is the presence of rare gas metastable atoms in the discharge plasma with number density of the order of 1012-1013 cm-3. This requirement mainly depends on the choice of a discharge system. In this study the number density values of argon metastable atoms were obtained in the condition of the dielectric-barrier discharge (DBD) at an atmospheric pressure.

  15. Treatment outcome and prognostic factor of CO2 laser cordectomy for early glottic cancer

    Science.gov (United States)

    Chung, Phil-Sang; Lee, Sang Joon

    2012-02-01

    Objectives: Laser cordectomy is very popular nowadays and become one of the treatments of choice for early glottis carcinoma. Transoral laser microsurgery has many advantages comparing conventional open surgery or radiation therapy. In this study, we examined the oncologic results of laser cordectomy for early glottic cancer and analyzed the prognostic impact on the survival of the several tumor-related and treatment-related factors. Methods: Patients who were diagnosed as early glottic squamous cell carcinoma, treated by laser cordectomy with curative intent were analyzed. Patients with preivous radiation therapy were included. From June 1988 to March 2005, 202 patients from five hospitals were analyzed (174 T1, 28 T2). Results: Five-year overall survival and disease-free survival were 98.4% and 84.9%. Twenty two patients developed local recurrence. Total laryngectomy was done in 6 patients and laryngeal preservation rate was 97%. Recurrence was higher in the patients with anterior commissure involvement (9/39) than without anterior commissure involvement (13/163). Recurrence was higher in T1b (4/15) than T1a (13/159). Previous radiation was also highly related to the recurrence (7/20 vs 15/182). Twenty patients with local recurrence after radiation therapy were treated by salvage laser cordectomy. Of them, 7 patients developed local recurrence and 5 year disease-free survival was 57%. Complication was rare with one case of hemorrhage. Tracheotomy was not necessary in all patients. Conclusions: Laser cordectomy for early glottic carcinoma showed high survival, laryngeal preservation rate and low complication rate. The prognostic factors were anterior commissure involvement, both vocal fold involvement and previous radiotherapy.

  16. Endobronchial Electrocautery and Argon Plasma Coagulation: A Practical Approach

    Directory of Open Access Journals (Sweden)

    Alain Tremblay

    2004-01-01

    Full Text Available The present review covers the technical and practical aspects of endobronchial electrocautery, including argon plasma coagulation, which have great potential for widespread use by pulmonologists around the world. The various electrocautery modes, power settings and electrode probes are described in detail, and the authors' clinical and technical approach is demonstrated with a narrative description and brief case presentations. Malignant airway obstruction, hemoptysis, web-like stenosis, stent related granulation tissue and early lung carcinomas are the most common indications for treatment. Advantages of electrocautery, such as low cost, rapid effect, safety and ease of use, are contrasted to other endobronchial therapeutic modalities. Published experience with electrocautery is reviewed.

  17. DNA repair in bacterial cultures and plasmid DNA exposed to infrared laser for treatment of pain

    International Nuclear Information System (INIS)

    Canuto, K S; Sergio, L P S; Marciano, R S; Guimarães, O R; Polignano, G A C; Geller, M; Fonseca, A S; Paoli, F

    2013-01-01

    Biostimulation of tissues by low intensity lasers has been described on a photobiological basis and clinical protocols are recommended for treatment of various diseases, but their effects on DNA are controversial. The objective of this work was to evaluate effects of low intensity infrared laser exposure on survival and bacterial filamentation in Escherichia coli cultures, and induction of DNA lesions in bacterial plasmids. In E. coli cultures and plasmids exposed to an infrared laser at fluences used to treat pain, bacterial survival and filamentation and DNA lesions in plasmids were evaluated by electrophoretic profile. Data indicate that the infrared laser (i) increases survival of E. coli wild type in 24 h of stationary growth phase, (ii) induces bacterial filamentation, (iii) does not alter topological forms of plasmids and (iv) does not alter the electrophoretic profile of plasmids incubated with exonuclease III or formamidopyrimidine DNA glycosylase. A low intensity infrared laser at the therapeutic fluences used to treat pain can alter survival of E. coli wild type, induce filamentation in bacterial cells, depending on physiologic conditions and DNA repair, and induce DNA lesions other than single or double DNA strand breaks or alkali-labile sites, which are not targeted by exonuclease III or formamidopyrimidine DNA glycosylase. (letter)

  18. Experimental microendoscopic photoablative laser goniotomy as a surgical model for the treatment of dysgenetic glaucoma.

    Science.gov (United States)

    Jacobi, P C; Dietlein, T S; Krieglstein, G K

    1996-11-01

    The aim of this study was to investigate the feasibility of photoablative Er:YAG laser goniotomy under microendoscopic control in a surgical cloudy corneal model of primary infantile glaucoma. Pectinate ligaments of 12 freshly enucleated cadaver porcine eyes were treated by ab interno single-pulse (5 mJ, 200 microseconds) Er:YAG laser (2.94 microns) photoablation. Through a clear corneal incision near the limbus an ophthalmic microendoscope (18 and 20 gauge) was inserted into the anterior chamber. Internal structures were observed and photoablative laser goniotomy was conducted under video guidance. Following treatment all eyes were prepared for light and scanning electron microscopy. Anterior chamber angle structures and tissue photoablation were clearly visualized on the videoscreen using ophthalmic microendoscopy. Energy settings of 5 mJ per pulse proved to be sufficient for reproducible photoablation of pectinate ligaments, accompanied by the root of the iris falling back and exposing trabecular meshwork. This was confirmed histopathologically. Scatter thermal damage was less than 30 microns. This new therapeutic modality, which combines endoscopic visualization of the internal structures with photoablative laser goniotomy, can be effective in the management of dysgenetic glaucoma in the presence of a cloudy cornea. High reproducibility of contact laser photoablation enabled sufficient control of incision depth and was not accompanied by inadvertent tissue damage to adjacent intraocular structures.

  19. Towards novel compact laser sources for non-invasive diagnostics and treatment

    Science.gov (United States)

    Rafailov, Edik U.; Litvinova, Karina S.; Sokolovski, Sergei G.

    2015-08-01

    An important field of application of lasers is biomedical optics. Here, they offer great utility for diagnosis, therapy and surgery. For the development of novel methods of laser-based biomedical diagnostics careful study of light propagation in biological tissues is necessary to enhance our understanding of the optical measurements undertaken, increase research and development capacity and the diagnostic reliability of optical technologies. Ultimately, fulfilling these requirements will increase uptake in clinical applications of laser based diagnostics and therapeutics. To address these challenges informative biomarkers relevant to the biological and physiological function or disease state of the organism must be selected. These indicators are the results of the analysis of tissues and cells, such as blood. For non-invasive diagnostics peripheral blood, cells and tissue can potentially provide comprehensive information on the condition of the human organism. A detailed study of the light scattering and absorption characteristics can quickly detect physiological and morphological changes in the cells due to thermal, chemical, antibiotic treatments, etc [1-5]. The selection of a laser source to study the structure of biological particles also benefits from the fact that gross pathological changes are not induced and diagnostics make effective use of the monochromatic directional coherence properties of laser radiation.

  20. Saturation spectroscopy of an optically opaque argon plasma

    Science.gov (United States)

    Eshel, Ben; Rice, Christopher A.; Perram, Glen P.

    2018-02-01

    A pure argon (Ar) plasma formed by a capacitively coupled radio-frequency discharge was analyzed using Doppler-free saturation spectroscopy. The expected line shape was a characteristic of sub-Doppler spectra in the presence of velocity-changing collisions, a narrow Lorentzian centered on a Doppler pedestal, but the observed line shapes contain a multi-peak structure, attributed to opacity of the medium. Laser absorption and inter-modulated fluorescence spectroscopy measurements were made to validate opacity as a driving factor of the observed line shapes. Spectral line shapes are further complicated by the spatial dependence of the pump laser, probe laser and of the absorbing medium, as well as the large absorbance of the transition under investigation. A numerical line shape was derived by accounting for the spatial variation of the pump and probe with a saturated line shape obtained from the rate equations for an equivalent two-level system. This simulated line shape shows good qualitative agreement with the trends observed in the data.

  1. Soft-laser use in the preoperative preparation and postoperative treatment of the patients with chronic lung abscesses

    Science.gov (United States)

    Ledin, A. O.; Dobkin, V. G.; Sadov, A. Y.; Galichev, K. V.; Rzeutsky, V. S.

    1999-07-01

    We counted expedient to include different methods of the soft-laser use in the preoperative medicinal program and in the postoperative period. During the preoperative preparation the basic group patients together with standard treatment received the combined soft-laser therapy, which included intravenous laser blood irradiation (ILBI) by He-Ve laser and external transcutaneous irradiation of the abscess projection by semi-conductorial arrenite-gallium laser. During postoperative treatment with ILBI remarkable changes were observed in the functional activity of the T- and B- cell. The soft-laser use allowed to achieve improvement of quality and shortening of terms of the preoperative preparation of 1,4 times, to level the immunosuppressive influence of surgery to reduce amount of the postoperative complications in 1,8 times and duration of the postoperative period in 1,5 times.

  2. Non surgical laser and light in the treatment of chronic diseases: a review based on personal experiences

    Science.gov (United States)

    Longo, L.

    2010-11-01

    Since many years some effects of non surgical laser and light on biological tissue have been demonstrated, in vitro and in vivo. This review is based on the results obtained by me and my colleagues/follower in Italy. Aim of our study is to verify the anti-inflammatory and regenerative effects of non surgical laser and light therapy on patients with chronic diseases not good treatable with traditional therapies, as diabetes, and central nervous system injuries. In addition, many clinical data have emerged from double-blind trials on laser treatment of rheumatic diseases and in sports medicine. So, we would like to do a review on the state of the art of non surgical laser treatment in medicine, included aesthetic laser and light therapy field. We discuss the indications and limitations of aesthetic laser medicine, as concluded from the data analysis of the published literature and from over thirty years of personal experiences.

  3. Non surgical laser and light in the treatment of chronic diseases: a review based on personal experiences

    International Nuclear Information System (INIS)

    Longo, L

    2010-01-01

    Since many years some effects of non surgical laser and light on biological tissue have been demonstrated, in vitro and in vivo. This review is based on the results obtained by me and my colleagues/follower in Italy. Aim of our study is to verify the anti-inflammatory and regenerative effects of non surgical laser and light therapy on patients with chronic diseases not good treatable with traditional therapies, as diabetes, and central nervous system injuries. In addition, many clinical data have emerged from double-blind trials on laser treatment of rheumatic diseases and in sports medicine. So, we would like to do a review on the state of the art of non surgical laser treatment in medicine, included aesthetic laser and light therapy field. We discuss the indications and limitations of aesthetic laser medicine, as concluded from the data analysis of the published literature and from over thirty years of personal experiences

  4. Microperimetry and fundus autofluorescence in diabetic macular edema: subthreshold micropulse diode laser versus modified early treatment diabetic retinopathy study laser photocoagulation.

    Science.gov (United States)

    Vujosevic, Stela; Bottega, Elisa; Casciano, Margherita; Pilotto, Elisabetta; Convento, Enrica; Midena, Edoardo

    2010-06-01

    The purpose of this study was to evaluate and compare microperimetry and fundus autofluorescence (FAF) after subthreshold micropulse diode laser versus modified Early Treatment Diabetic Retinopathy Study photocoagulation for clinically significant diabetic macular edema. A prospective randomized clinical trial including 62 eyes (50 patients) with untreated, center-involving, clinically significant diabetic macular edema was performed. All patients underwent best-corrected visual acuity determination (logarithm of the minimum angle of resolution), slit-lamp biomicroscopy, FAF, optical coherence tomography, microperimetry (macular sensitivity), and fluorescein angiography before and after treatment. Best-corrected visual acuity, optical coherence tomography, microperimetry, and FAF were repeated at 1-, 3-, 6-, 9-, and 12-month follow-up examinations. Fluorescein angiography was performed at baseline and at 6 and 12 months. Before treatment, demographic and macular parameters were not different between the two treatment groups. At 12 months, best-corrected visual acuity remained stable in both groups (P = 0.41 and P = 0.82), mean central retinal thickness decreased in both groups (P = 0.0002 and P autofluorescence never changed in the micropulse diode laser group even after retreatment. In the Early Treatment Diabetic Retinopathy Study group, FAF increased up to 9 months and decreased in 6 eyes (20%) at 12 months. Micropulse diode laser seems to be as effective as modified Early Treatment Diabetic Retinopathy Study laser photocoagulation in the treatment of clinically significant diabetic macular edema. Micropulse diode laser treatment does not determine any change on FAF showing (at least) nonclinically visible damage of the retinal pigment epithelium. Microperimetry data encourage the use of a new, less aggressive laser therapeutic approach in the treatment of clinically significant diabetic macular edema.

  5. Assessment of the effectiveness of low level laser in the treatment of alveolar osteitis

    Directory of Open Access Journals (Sweden)

    Jovanović Goran

    2011-01-01

    Full Text Available Background/Aim. Alveolar osteitis (AO is the extraction wound healing disorder with a presence of severe pain. Low level laser therapy stimulates cell metabolism and microcirculation, have has pronounced analgesic, antiedematous and anti-inflammatory effect and speeds up wound healing process. The aim of this study was to present results of clinical research that examined the effectiveness of low level laser in pain relief and healing of extraction wounds with alveolar osteitis in the lower jaw which was formed on the second day after tooth extraction. Methods. The study was conducted on 60 subjects divided into the study and the control group. In both groups extraction wounds were processed in similar way, except that in the study group was applied daily treatment of low level laser with a total of eight sessions of radiation, while in the control group extraction wounds were dressed with zinc oxide eugenol paste, which was changed every 48 hours up to the pain cessation. Measurement of pain intensity was done with a visual analogue scale (VAS 10 min prior to processing of extraction wounds and daily for the next eight days. Assessment of the effectiveness of low level laser on healing of extraction wounds was performed on the day eight of the treatment. Results. On the day five after beginning of the treatment of extraction wounds with alveolar osteitis in the patients of the study group a lower average value of pain as compared to the control group was registered. This difference was increased within the following days. Extraction wounds healing in the study group was more successful and faster than in the control group. Conclusion. This study suggested that the reduction of pain was more pronounced in the patients with alveolar osteitis whose extraction wounds were subjected to low level laser radiation in comparison to those in which extraction wounds were treated with zinc oxide eugenol paste.

  6. Comparison of Pneumatic and Laser Lithotripsy in the Endoscopic Treatment of Upper Ureteral Stones

    Directory of Open Access Journals (Sweden)

    Ozer Guzel

    2016-04-01

    Full Text Available Aim: We aimed to compare the success rate of the use of a pneumatic and a holmium laser lithotripter for endoscopic treatment of upper ureteral calculi with semirigid uretero-renoscopy (URS. Material and Method: A total of 74 patients were included in this study. The patients were divided into two groups; a ballistic lithotripter was used for group 1 containing 33 and a Holmium-YAG laser lithotripter for the remaining 41 patients in group 2. Both groups were compared in terms of stone size the duration of the operation, postoperative hospitalization time, stone-free rate and complications. Results: The mean age of the patients was 47.6. The mean stone size in groups 1 and 2 were 16.4mm and 11.0mm, respectively (p=0.043. The mean stone-free rate groups 1 and 2 were 78.7% and 80.5% respectively at the approximately 1 month follow-up (p=0.391. In group 1 two patients and in group 2 two patients had a minor complication (ClavienI-II. In group 1 three patients had major complications due to ureteral perforation (Clavien 3a and 3b. No major complications (Clavien III-V occurred in Group 2. Discussion: Based on these findings laser lithotripsy can be regarded as safer. If laser lithotripter is available in medical centers, we argue that it should be the first choice for the treatment of upper ureteral stones.

  7. Intravitreal bevacizumab versus laser treatment in type 1 retinopathy of prematurity: report on fluorescein angiographic findings.

    Science.gov (United States)

    Lepore, Domenico; Quinn, Graham E; Molle, Fernando; Baldascino, Antonio; Orazi, Lorenzo; Sammartino, Maria; Purcaro, Velia; Giannantonio, Carmen; Papacci, Patrizia; Romagnoli, Costantino

    2014-11-01

    To compare the structural outcome at 9 months of eyes treated with intravitreal injection of bevacizumab with fellow eyes treated with conventional laser photoablation in zone I type 1 retinopathy of prematurity (ROP). Single randomized controlled trial. All inborn babies with type 1 zone I ROP at a single institution were included in the study. One eye was randomized to receive an intravitreal injection of 0.5 mg bevacizumab; the fellow eye received conventional laser photoablation. Digital fundus photographs and fluorescein angiography (FA) using the RetCam (Clarity Medical Systems Inc., Pleasanton, CA) were performed before treatment and 9 months after treatment. Presence of retinal and choroidal abnormalities on FA at 9 months. Thirteen infants were enrolled; 1 died 3 months after birth. One laser-treated eye progressed to stage 5 retinal detachment. The remaining 23 eyes had favorable structural results at the 9-month follow-up and provided FA results. At 9 months of age, all eyes treated with a bevacizumab injection were noted to have abnormalities at the periphery (large avascular area, abnormal branching, shunt) or the posterior pole (hyperfluorescent lesion, absence of foveal avascular zone). These posterior and peripheral lesions were not observed in the majority of the lasered eyes. This study documents significant vascular and macular abnormalities of eyes in the bevacizumab group. Long-lasting implications of these abnormalities for visual function of the child need to be studied. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  8. Comparison of Q-switched Nd:YAG laser alone versus its combination with ultrapulse CO2 laser for the treatment of black tattoo.

    Science.gov (United States)

    Vanarase, Mithila; Gautam, Ram Krishan; Arora, Pooja; Bajaj, Sonali; Meena, Neha; Khurana, Ananta

    2017-10-01

    Q-switched lasers are conventionally used for the treatment of black tattoo. However, they require multiple sittings, and the response may be slow due to competing epidermal pigment in dark skin. To compare the efficacy of Q-switched Nd:YAG laser alone with its combination with ultrapulse CO 2 for the removal of black tattoo. Sixty patients with black tattoo were randomized into two groups viz., group A and group B. Group A was treated with QS Nd:YAG laser (1064 nm) alone, and group B received combination of ablative ultrapulse CO 2 followed by fixed-dose QS Nd:YAG laser (1064 nm), at 6-week interval for a maximum of 6 sittings. After each sitting, 3 independent physicians noted percentage of improvement that was evaluated using visual analogue scale (VAS) and grading system for tattoo ink lightening (TIL). Combination laser (group B) showed statistically significant improvement in mean VAS score in the last 2 noted visits as compared to 1st session (p tattoos, combination of ultrapulse CO 2 laser and QS Nd:YAG laser is superior to QS Nd:YAG laser alone.

  9. Development of electrical excited CO2-laser with transversal gas flow as well an axial flowed CO2-laser for material treatment, in particular for cutting

    International Nuclear Information System (INIS)

    Wollermann-Windgasse, R.; Ackermann, F.

    1987-04-01

    The project describes the development of a new generation of CO 2 -lasers using high frequency discharge (13.56 MHz) for laser excitation by capacitive dielectrical input. HF-excitation has a lot of advantages compared with direct current technology, these are higher electrical input power into the plasma, better homogeneity and stability of discharges. In addition to this, HF-excitation shows excellent possibilities for pulsing and modulation. As a result of this, there are compact powerful laser systems with the possibility of scaling up to the multi-kW-range. The examination included fast transversal flowed as well as fast axial flowed systems. In the end of this project development prototypes with laser output power of 1000 W, 1500 W and 3000 W were available. Detailed attempts of application show that these lasers on grounds of excellent laser output quality and controlability of laser power specifically to each process make possible new ways for material treatment by laser. (orig./HP) [de

  10. Comparison of treatment with an Alexandrite picosecond laser and Nd:YAG nanosecond laser for removing blue-black Chinese eyeliner tattoos.

    Science.gov (United States)

    Zhang, Mengli; Huang, Yuqing; Lin, Tong; Wu, Qiuju

    2018-02-28

    To retrospectively evaluate the efficacy of an Alexandrite picosecond laser versus Nd:YAG nanosecond laser for removing blue-black eyeliner tattoos which have existed more than 10 years. A total of 40 patients were treated with an Alexandrite picosecond laser in our department from August 2015 to July 2017, with a fluence of 1.96-6.37J/cm 2 , spot size of 2.0-3.6 mm, and pulse width of 750 ps. Another 32 patients were treated with an Nd:YAG nanosecond laser, with a fluence of 2.80-7.00 J/cm 2 , spot size of 3 mm, and pulse width of 5-20 ns. All analysed patients completed at least one treatment and follow-up. The median number of treatment for all the patients was 1 (range, 1-4). After a single session, no difference was found between the two lasers for the eyeliner removal (p > 0.05). For the people who achieved an excellent response of tattoo clearance, there was still no difference between the two groups (p > 0.05). Transient side effects were observed in two groups, but neither group had significant adverse reactions. To treat blue-black Chinese eyeliner tattoos over 10 years, Alexandrite picosecond laser does not provide better clearance than the Nd:YAG nanosecond laser.

  11. Patterns of Traditional Chinese Medicine Diagnosis in Thermal Laser Acupuncture Treatment of Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Lizhen Wang

    2013-01-01

    Full Text Available Knee osteoarthritis (OA manifests with pain, joint stiffness, and limited function. In traditional Chinese medicine, knee OA is differentiated into three patterns: yang deficiency and cold coagulation, kidney deficiency, and blood stasis. The objective of this study was to determine whether yang deficiency cold coagulation patients respond better to thermal laser acupuncture treatment than do non-yang deficient patients. Fifty-two patients with OA were allocated to group A (yang deficient, n=26 or B (non-yang deficient, n=26. All patients received a 20-min thermal laser acupuncture treatment at acupoint Dubi (ST 35 three times a week for two weeks and twice a week for another four weeks. Outcome assessments were performed immediately after the first treatment, and at weeks 2, 6, and 10. Group A function scores were significantly better than those of Group B at weeks 2 (P=0.049, 6 (P=0.046, and 10 (P=0.042, but no significant differences were found between the two groups in pain and stiffness scores at any time point. No significant adverse effect was observed. The combined 10.6 μm–650 nm laser treatment might be most beneficial to yang deficiency cold coagulation knee OA patients, particularly in improving function.

  12. Frequency-doubled dual-pulse freddy lithrotripsy laser in the treatment of urinary tract calculi

    Science.gov (United States)

    Huang, Xuyuan; Bo, Juanjie; Chen, Bin; Wang, Yi-Xin

    2005-07-01

    Background and Purpose: The Frequency-Doubled Dual-Pulse Nd:YAG FREDDY laser is a short-pulsed, solid-state laser with wavelengths of 532 and 1064 nm that was developed for intracorporeal lithothripsy. This clinical study is designed to test its fragmentation efficiency in the treatment of urinary tract calculi. Patients and Methods: 500 urinary tract calculi treated in 194 female and 306 male patients with a mean age of 46 years. All patients were assessed one week post-op with a plain film of the kidneys, ureters and bladder. Stone-free rate and final outcome have been evaluated. Final outcome is defined as stone-free or residual fragments. Analysis has been made according to stone size, location and number of stones. The analgesia requirements during each treatment and complications have also been analyzed. Results: The overall stone-free rate for patients was 92.4%. The success rate for upper ureteral was 85.1% (126/148), while the rate for mid/lower was 95.3% (307/322). Bladder stone success rate 96.6% (29/30). Of all 38 incomplete fragmentations, 20 cases (4%) were treated with ESWL and 18 cases (3.6%) had open surgery. Neither fever nor pyonephrosis was reported. The average laser treatment time was 3.3 minutes and the average post-op hospitalization was 2.5 days. Conclusions: The FREDDY laser is an extremely efficient and safe minimally invasive lithotripsy treatment for urinary stones. It should be considered as an alternative treatment for urolithiasis.

  13. Electron impact with argon excitation out of the e-Ar(3p54s,J = 2)

    International Nuclear Information System (INIS)

    Jin Shiqi; Xu Zhizhan

    1998-01-01

    It is shown that the electron impact with argon excitation out of the metastable to the 3p 5 4p levels is very important for spectrum, laser physics and plasma processing. Analysis of the cross sections of 3p 5 4p, J = 3 level in manifolds of 3p 5 4p is valuable. It also provides the atomic character of emission harmonics in intense laser field

  14. Contraction ionization waves in the argon contracted discharge

    International Nuclear Information System (INIS)

    Golubovskij, Yu.B.; Kulikov, V.V.; Nekutchaev, V.O.

    1985-01-01

    An investigation of ionization waves in the argon contracted discharge and a definition of their arising propagation mechanism accounting for the specificity of elementary pocesses characteristic of argon are presented. (author)

  15. Osteogenesis differentiation of human periodontal ligament cells by CO2 laser-treatment stimulating macrophages via BMP2 signalling pathway

    International Nuclear Information System (INIS)

    Hsieh, Wen-Hui; Chen, Yi-Jyun; Hung, Chi-Jr; Huang, Tsui-Hsien; Kao, Chia-Tze; Shie, Ming-You

    2014-01-01

    Immune reactions play an important role in determining the biostimulation of bone formation, either in new bone formation or inflammatory fibrous tissue encapsulation. Macrophage cell, the important effector cells in the immune reaction, which are indispensable for osteogenesis and their heterogeneity and plasticity, render macrophages a primer target for immune system modulation. However, there are very few studies about the effects of macrophage cells on laser treatment-regulated osteogenesis. In this study, we used CO 2 laser as a model biostimulation to investigate the role of macrophage cells on the CO 2 laser stimulated osteogenesis. Bone morphogenetic protein 2 (BMP2) was also significantly up regulated by the CO 2 laser stimulation, indicating that macrophage may participate in the CO 2 laser stimulated osteogenesis. Interestingly, when laser treatment macrophage-conditioned medium were applied to human periodontal ligament cells (hPDLs), the osteogenesis differentiation of hPDLs was significantly enhanced, indicating the important role of macrophages in CO 2 laser-induced osteogenesis. These findings provided valuable insights into the mechanism of CO 2 laser-stimulated osteogenic differentiation, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of laser treatment. (paper)

  16. Iridotomy with red krypton laser.

    Science.gov (United States)

    Yassur, Y; David, R; Rosenblatt, I; Marmour, U

    1986-01-01

    Iridotomy with red krypton laser instead of blue-green argon laser was performed on 68 eyes with various types of angle-closure glaucoma. Patent iridotomy was obtained in all the eyes, mostly in one working session. In eight eyes secondary closure by pigment needed reopening with a few applications at the iridotomy site. There were no immediate or late complications of importance, the main advantage of the technique being the avoidance of the corneal epithelial and endothelial burns which commonly occur during argon laser iridotomy, particularly when the anterior chamber is shallow. PMID:3964628

  17. Argon-ion contamination of the plasmasphere

    International Nuclear Information System (INIS)

    Chiu, Y.T.; Cornwall, J.M.; Luhmann, J.G.; Schulz, M.

    1979-01-01

    This paper applies present observational and analytic knowledge on effects of plasma beam interaction wth the magnetosphere to the plasmasphere contamination problem of the argon ion engine exhaust expected to be deposited in the magnetosphere during the construction phase of the Satellite Power System. Effects of plasmasphere, ionosphere, and radiation belt modifications are discussed

  18. Silicon compounds of neon and argon

    Czech Academy of Sciences Publication Activity Database

    Roithová, J.; Schröder, Detlef

    -, č. 46 (2009), s. 8788-8790 ISSN 1433-7851 R&D Projects: GA ČR GA203/09/1223 Grant - others: ERC (XE) Adg HORIZOMS Institutional research plan: CEZ:AV0Z40550506 Keywords : argon * bond formation * dications * neon Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 11.829, year: 2009

  19. Performance of a uranium liquid argon calorimeter

    International Nuclear Information System (INIS)

    Tuts, P.M.

    1987-01-01

    The author presents results on the performance of a uranium and liquid argon colorimeter in the NW test beam at Fermilab. This study describes the calorimeter, and discusses its performance with electrons, pions and muons from 10 GeV to 150 GeV. The performance parameters measure response, linearity, resolution, compensation, and e/π separation

  20. SLD liquid argon calorimeter prototype test results

    International Nuclear Information System (INIS)

    Dubois, R.; Eigen, G.; Au, Y.

    1985-10-01

    The results of the SLD test beam program for the selection of a calorimeter radiator composition within a liquid argon system are described, with emphasis on the study of the use of uranium to obtain equalization of pion and electron responses

  1. Commissioning of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Cooke, Mark S

    2009-01-01

    A selection of ATLAS liquid argon (LAr) calorimeter commissioning studies are presented. These include a coherent noise study, a measurement of the quality of the physics pulse shape prediction, and energy and time reconstruction analyses with cosmic and single beam signals.

  2. Thermal decomposition of barium valerate in argon

    DEFF Research Database (Denmark)

    Torres, P.; Norby, Poul; Grivel, Jean-Claude

    2015-01-01

    The thermal decomposition of barium valerate (Ba(C4H9CO2)(2)/Ba-pentanoate) was studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage optical microscopy. Melting takes place in two different steps, at 200 degrees C and 280...

  3. [Efficiency of combined methods of hemorroid treatment using hal-rar and laser destruction].

    Science.gov (United States)

    Rodoman, G V; Kornev, L V; Shalaeva, T I; Malushenko, R N

    2017-01-01

    To develop the combined method of treatment of hemorrhoids with arterial ligation under Doppler control and laser destruction of internal and external hemorrhoids. The study included 100 patients with chronic hemorrhoids stage II and III. Combined method of HAL-laser was used in study group, HAL RAR-technique in control group 1 and closed hemorrhoidectomy with linear stapler in control group 2. Сomparative evaluation of results in both groups was performed. Combined method overcomes the drawbacks of traditional surgical treatment and limitations in external components elimination which are inherent for HAL-RAR. Moreover, it has a higher efficiency in treating of hemorrhoids stage II-III compared with HAL-RAR and is equally safe and well tolerable for patients. This method does not increase the risk of recurrence, reduces incidence of complications and time of disability.

  4. Enhancement of methane gas sensing characteristics of graphene oxide sensor by heat treatment and laser irradiation.

    Science.gov (United States)

    Assar, Mohammadreza; Karimzadeh, Rouhollah

    2016-12-01

    The present study uses a rapid, easy and practical method for cost-effective fabrication of a methane gas sensor. The sensor was made by drop-casting a graphene oxide suspension onto an interdigital circuit surface. The electrical conductivity and gas-sensing characteristics of the sensor were determined and then heat treatment and in situ laser irradiation were applied to improve the device conductivity and gas sensitivity. Real-time monitoring of the evolution of the device current as a function of heat treatment time revealed significant changes in the conductance of the graphene oxide sensor. The use of low power laser irradiation enhanced both the electrical conductivity and sensing response of the graphene oxide sensor. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Application of double-layered skin phantoms for optical flow imaging during laser tattoo treatments

    Science.gov (United States)

    Lee, Byeong-il; Song, Woosub; Kim, Hyejin; Kang, Hyun Wook

    2016-05-01

    The feasible application of double-layered skin phantoms was evaluated to identify artificial blood flow with a Doppler optical coherence tomography (DOCT) system for laser tattoo treatments. Polydimethylsiloxane (PDMS) was used to fabricate the artificial phantoms with flow channels embedded. A double-integrating sphere system with an inverse adding-doubling method quantified both the absorption and the reduced scattering coefficients for epidermis and dermis phantoms. Both OCT and caliper measurements confirmed the double-layered phantom structure (epidermis = 136 ± 17 µm vs. dermis = 3.0 ± 0.1 mm). The DOCT method demonstrated that high flow rates were associated with high image contrast, visualizing the position and the shape of the flow channel. Application of the channel-embedded skin phantoms in conjunction with DOCT can be a reliable technique to assess dynamic variations in the blood flow during and after laser tattoo treatments.

  6. Numerical algorithm for laser treatment of powder layer with variable thickness

    Science.gov (United States)

    Soboleva, Polina; Knyazeva, Anna

    2017-12-01

    Two-dimensional model of laser treatment of powder layer on the substrate is proposed in this paper. The model takes into account the shrinkage of powder layer due to the laser treatment. Three simplified variants of the model were studied. Firstly, the influence of optical properties of powder layer on the maximal temperature was researched. Secondly, two-dimensional model for given thickness of powder layer was studied where practically uniform temperature distribution across thin powder layer was demonstrated. Then, the numerical algorithm was developed to calculate the temperature field for the area of variable size. The impact of the optical properties of powder material on the character of the temperature distribution was researched numerically.

  7. The use of laser therapy in complex treatment of ulcer diseases in participants of Chernobyl accident clean-up

    International Nuclear Information System (INIS)

    Simonova, L.Yi.; Rozdyil's'kij, S.Yi.; Kulyinyich, G.V.; Fertman, V.Z.; Krapivnij, O.O.; Abramova, L.P.; Byilogurova, L.V.; Levchenko, A.P.

    2001-01-01

    The study involved 59 male patients with relapsing duodenal ulcer who had participated in Chernobyl accident clean-up. Laser therapy was administrated daily on the projection of the zone of the ulcer and acupuncture zones. The obtained results allow to conclude that transcutaneous laser therapy is an effective method of treatment of ulcer disease

  8. Single-treatment skin tightening by radiofrequency and long-pulsed, 1064-nm Nd: YAG laser compared.

    Science.gov (United States)

    Key, Douglas J

    2007-02-01

    To compare single-treatment facial skin tightening achieved with the current radiofrequency (RF) protocol with single-treatment tightening achieved with the long-pulsed, 1064-nm Nd:YAG laser. A total of 12 patients were treated with RF energy on one side of the face and laser energy on the other. Results were evaluated on a numerical scale (0-12 with 12 = greatest enhancement) from pre- and posttreatment photographs by a blinded panel. Upper face improvement (posttreatment score minus pretreatment score) was essentially the same on both sides (30.2 and 31.3% improvement for laser and RF, respectively, P=0.89). Lower face improvement was greater in the laser-treated side (35.7 and 23.8% improvement for laser and RF, respectively), but the difference was not significant (P=0.074). Overall face improvement was significantly greater on the laser-treated side (47.5 and 29.8% improvement for laser and RF, respectively, P=0.028). A single high-fluence treatment with the long-pulse 1064-nm Nd:YAG laser may improve skin laxity more than a single treatment with the RF device. Further controlled split-face or very large non-self controlled studies are needed to conclusively determine the relative efficacies of the two technologies. (c) 2007 Wiley-Liss, Inc.

  9. Localized changes in Retinal Vessel Caliber after focal/grid laser treatment in Patients with Diabetic Macular Edema

    DEFF Research Database (Denmark)

    Lundberg, Lars Kristian; Kawasaki, Ryo; Sjølie, Anne K

    2013-01-01

    PURPOSE:: To compare retinal vessel caliber changes at the macula region and surrounding the optic disk after focal/grid laser treatment for diabetic macular edema. METHODS:: The study included 69 eyes from 46 patients treated with focal/grid laser for diabetic macular edema. Retinal photographs...

  10. 46 CFR 151.50-36 - Argon or nitrogen.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Argon or nitrogen. 151.50-36 Section 151.50-36 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-36 Argon or nitrogen. (a) A cargo tank that contains argon or nitrogen and that has a maximum allowable working pressure of 172 kPa (25...

  11. Detrapping of tungsten nanoparticles in a direct-current argon glow discharge

    Energy Technology Data Exchange (ETDEWEB)

    Couëdel, L., E-mail: lenaic.couedel@univ-amu.fr; Kumar, K. Kishor; Arnas, C. [Laboratoire de Physique des Interactions Ioniques et Moléculaires, CNRS, Aix-Marseille Université, 13397 Marseille (France)

    2014-12-15

    Nanoparticles are grown from the sputtering of a tungsten cathode in a direct current argon glow discharge. Laser light scattering of a vertical laser sheet going through the plasma reveals that the dust particle cloud is compressed and pushed towards the anode during the discharge. Scanning electron microscopy images of substrates exposed to the plasma for given durations show that dust particles are continuously falling down on the anode during the discharge. These observations are explained by the fact that the electrostatic force at the negative glow-anode sheath boundary cannot balance the ion drag, gravity, and thermophoresis forces for particles of more than a few tens of nanometres in diameter.

  12. Laser acupuncture therapy in patients with treatment-resistant temporomandibular disorders.

    Directory of Open Access Journals (Sweden)

    Wen-Long Hu

    Full Text Available To investigate the clinical effects of laser acupuncture therapy for temporomandibular disorders (TMD after ineffective previous treatments.A retrospective observational study was conducted in 29 treatment-resistant TMD patients (25 women, 4 men; age range, 17-67 years. Subjects were treated 3 times per week for 4 weeks with the Handylaser Trion (GaAlAs laser diode, 810 nm, 150 mW, pulsed waves, which delivered 0.375 J of energy (5 s to ST7, ST6, and LI4 and 3 J (40 s to each Ashi point, 7.5-26.25 J/cm2 in total. The visual analog scale (VAS and maximal mouth opening (MMO were evaluated before and after treatment.VAS analysis showed that the patients were free of pain at rest (endpoint after 5.90±6.08 sessions of laser acupuncture for acute TMD and after 16.21±17.98 sessions for chronic TMD. The VAS score on palpation of the temporomandibular joint reduced to 0.30±0.67 for patients with acute TMD (p = 0.005 and to 0.47±0.84 for those with chronic TMD (p<0.001. The MMO significantly increased in patients with acute TMD (7.80±5.43 mm, p = 0.008 and in patients with chronic TMD (15.58±7.87 mm, p<0.001.Our study shows that laser acupuncture therapy improves the symptoms of treatment-resistant TMD. Further studies with a more appropriate design, involving long-term follow-up examinations in a larger patient sample, are needed to evaluate its efficacy.

  13. Cold surface treatments on fiber-reinforced plastics by pulsed laser

    OpenAIRE

    Gebauer, Jana; Franke, Volker; Klotzbach, Udo; Beyer, Eckhard

    2017-01-01

    The importance of lightweight materials increases in all aspects of manufacturing, e.g. automotive, sports equipment and aerospace [1]. Making fiber reinforced plastics suitable for use in mass production new technologies have to be developed to overcome existing challenges e.g. shorter cycle times or more efficient resource usage. Innovative laser systems are used for a full range of treatments for all materials, like structuring, drilling, joining and cutting [2] - [4]. This paper presents ...

  14. Endoscopic laser-induced steam generator: a new method of treatment for early gastric cancer

    Science.gov (United States)

    Hayashi, Takuya; Arai, Tsunenori; Tajiri, Hisao; Nogami, Yashiroh; Hino, Kunihiko; Kikuchi, Makoto

    1996-05-01

    The minimum invasive endoscopic treatment for early gastric cancer has been popular in Japan. The endoscopic mucosal resection and laser coagulation by Nd:YAG laser irradiation has been the popular treatment method in this field. However, the submucosal cancer has not been successfully treated by these methods. To treat the submucosal cancer endoscopically, we developed a new coagulation therapy using hot steam generated by Nd:YAG laser. The steam of which temperature was over 10 deg. in Celsius was generated by the laser power of 30 W with 5 ml/min. of saline. The steam was emitted to canine gastric wall under laparotomy or endoscopy for 50 s respectively. Follow up endoscopy was performed on 3, 7, 14, 28 days after the treatment. Histological examination was studied on 7, 28 days, and just after the emission. In the acute observation, the submucosal layer was totally coagulated. On the 7th day, ulceration with white coat was seen. The mucosal defect, submucosal coagulation, and marked edema without muscle degeneration were found by the histological study. On the 14th day, the ulcer advanced in the scar stage. On the 28th day, it completely healed into white scar with mucosal regeneration and mucosal muscle thickening. We could obtain reproducible coagulation up to deep submucosal layer with large area in a short operation time. Moreover there were no degeneration of proper muscle. This treatment effectiveness could be easily controlled by the steam temperature and emission duration. We think that this method can be applied to early gastric cancer including the submucosal cancer, in particular poor risk case for operation. Further study should be done to apply this method to clinical therapy.

  15. Use of the pulsed infrared diode laser (904 nm) in the treatment of alopecia areata.

    Science.gov (United States)

    Waiz, Makram; Saleh, Anmar Z; Hayani, Raafa; Jubory, Samar O

    2006-04-01

    Alopecia areata is a rapid and complete loss of hair in one or several patches, usually on the scalp, affecting both males and females equally. It is thought to be an autoimmune disease which is treated with different modalities with variable success. Laser treatment of different wavelengths has been used in the management of this problem. To study the effect of the pulsed infrared diode laser (904 nm) in the treatment of alopecia areata.Methods. Sixteen patients with 34 resistant patches that had not responded to different treatment modalities for alopecia areata were enrolled in this study. In patients with multiple patches, one patch was left as a control for comparison. Patients were treated on a four-session basis, once a week, with a pulsed diode laser (904 nm) at a pulse rate of 40/s. A photograph was taken of each patient before and after treatment. The treated patients were 11 males (68.75%) and five females (31.25%). Their ages ranged between 4 and 50 years with a mean of 26.6+/-SD of +/-13.8, and the durations of their disease were between 12 months and 6 years with a mean of 13.43+/-SD of +/-18.34. Regrowth of hair was observed in 32 patches (94%), while only two patches (6%) failed to show any response. No regrowth of hair was observed in the control patches. The regrowth of hair appeared as terminal hair with its original color in 29 patches (90.6%), while three patches (9.4%) appeared as a white villous hair. In patients who showed response, the response was detected as early as 1 week after the first session in 24 patches (75%), while eight patients (25%) started to show response from the second session. The pulsed infrared diode laser is an effective mode of therapy with a high success rate for resistant patches of alopecia areata.

  16. Different lasers and techniques for proliferative diabetic retinopathy.

    Science.gov (United States)

    Moutray, Tanya; Evans, Jennifer R; Lois, Noemi; Armstrong, David J; Peto, Tunde; Azuara-Blanco, Augusto

    2018-03-15

    Diabetic retinopathy (DR) is a chronic progressive disease of the retinal microvasculature associated with prolonged hyperglycaemia. Proliferative DR (PDR) is a sight-threatening complication of DR and is characterised by the development of abnormal new vessels in the retina, optic nerve head or anterior segment of the eye. Argon laser photocoagulation has been the gold standard for the treatment of PDR for many years, using regimens evaluated by the Early Treatment of Diabetic Retinopathy Study (ETDRS). Over the years, there have been modifications of the technique and introduction of new laser technologies. To assess the effects of different types of laser, other than argon laser, and different laser protocols, other than those established by the ETDRS, for the treatment of PDR. We compared different wavelengths; power and pulse duration; pattern, number and location of burns versus standard argon laser undertaken as specified by the ETDRS. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 5); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 8 June 2017. We included randomised controlled trials (RCTs) of pan-retin