Measurement of laser welding pool geometry using a closed convex active contour model

International Nuclear Information System (INIS)

Zheng, Rui; Zhang, Pu; Duan, Aiqing; Xiao, Peng

2014-01-01

The purpose of this study was to develop a computer vision method to measure geometric parameters of the weld pool in a deep penetration CO 2 laser welding system. Accurate measurement was achieved by removing a huge amount of interference caused by spatter, arc light and plasma to extract the true weld pool contour. This paper introduces a closed convex active contour (CCAC) model derived from the active contour model (snake model), which is a more robust high-level vision method than the traditional low-level vision methods. We made an improvement by integrating an active contour with the information that the weld pool contour is almost a closed convex curve. An effective thresholding method and an improved greedy algorithm are also given to complement the CCAC model. These influences can be effectively removed by using the CCAC model to acquire and measure the weld pool contour accurately and relatively fast. (paper)

Magnetoencephalographic study on facial movements

Directory of Open Access Journals (Sweden)

Kensaku eMiki

2014-07-01

Full Text Available In this review, we introduced our three studies that focused on facial movements. In the first study, we examined the temporal characteristics of neural responses elicited by viewing mouth movements, and assessed differences between the responses to mouth opening and closing movements and an averting eyes condition. Our results showed that the occipitotemporal area, the human MT/V5 homologue, was active in the perception of both mouth and eye motions. Viewing mouth and eye movements did not elicit significantly different activity in the occipitotemporal area, which indicated that perception of the movement of facial parts may be processed in the same manner, and this is different from motion in general. In the second study, we investigated whether early activity in the occipitotemporal region evoked by eye movements was influenced by a face contour and/or features such as the mouth. Our results revealed specific information processing for eye movements in the occipitotemporal region, and this activity was significantly influenced by whether movements appeared with the facial contour and/or features, in other words, whether the eyes moved, even if the movement itself was the same. In the third study, we examined the effects of inverting the facial contour (hair and chin and features (eyes, nose, and mouth on processing for static and dynamic face perception. Our results showed the following: (1 In static face perception, activity in the right fusiform area was affected more by the inversion of features while that in the left fusiform area was affected more by a disruption in the spatial relationship between the contour and features, and (2 In dynamic face perception, activity in the right occipitotemporal area was affected by the inversion of the facial contour.

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.

Laser-assisted fabrication of materials

CERN Document Server

Manna, Indranil

2013-01-01

Laser assisted fabrication involves shaping of materials using laser as a source of heat. It can be achieved by removal of materials (laser assisted cutting, drilling, etc.), deformation (bending, extrusion), joining (welding, soldering) and addition of materials (surface cladding or direct laser cladding). This book on ´Laser assisted Fabrication’ is aimed at developing in-depth engineering concepts on various laser assisted macro and micro-fabrication techniques with the focus on application and a review of the engineering background of different micro/macro-fabrication techniques, thermal history of the treated zone and microstructural development and evolution of properties of the treated zone.

Efficacy and safety of 10,600-nm carbon dioxide fractional laser on facial skin with previous volume injections

Directory of Open Access Journals (Sweden)

Josiane Hélou

2013-01-01

Full Text Available Background: Fractionated carbon dioxide (CO 2 lasers are a new treatment modality for skin resurfacing. The cosmetic rejuvenation market abounds with various injectable devices (poly-L-lactic acid, polymethyl-methacrylate, collagens, hyaluronic acids, silicone. The objective of this study is to examine the efficacy and safety of 10,600-nm CO 2 fractional laser on facial skin with previous volume injections. Materials and Methods: This is a retrospective study including 14 patients treated with fractional CO 2 laser and who have had previous facial volume restoration. The indication for the laser therapy, the age of the patients, previous facial volume restoration, and side effects were all recorded from their medical files. Objective assessments were made through clinical physician global assessment records and improvement scores records. Patients′ satisfaction rates were also recorded. Results: Review of medical records of the 14 patients show that five patients had polylactic acid injection prior to the laser session. Eight patients had hyaluronic acid injection prior to the laser session. Two patients had fat injection, two had silicone injection and one patient had facial thread lift. Side effects included pain during the laser treatment, post-treatment scaling, post-treatment erythema, hyperpigmentation which spontaneously resolved within a month. Concerning the previous facial volume restoration, no granulomatous reactions were noted, no facial shape deformation and no asymmetry were encountered whatever the facial volume product was. Conclusion: CO 2 fractional laser treatments do not seem to affect facial skin which had previous facial volume restoration with polylactic acid for more than 6 years, hyaluronic acid for more than 0.5 year, silicone for more than 6 years, or fat for more than 1.4 year. Prospective larger studies focusing on many other variables (skin phototype, injected device type are required to achieve better

Multifractional microablative laser combined with spacially modulated ablative (SMA) technology for facial skin rejuvenation.

Science.gov (United States)

Hersant, Barbara; SidAhmed-Mezi, Mounia; Chossat, Adrien; Meningaud, Jean Paul

2017-01-01

Due to the increasing demand for aesthetic procedures, especially facial aesthetic surgery, a new laser technology has been developed for facial skin rejuvenation and wrinkle treatment. The aim of this study was to objectively and subjectively assess the clinical efficacy and safety of Erbium:YAG laser combined with Spatially Modulated Ablation (Er:YAG + SMA) on facial skin rejuvenation. Patients with Fitzpatrick skin type's I-IV were prospectively included. Inclusion criteria consisted of having wrinkles and irregular skin texture. All patients underwent two Er:YAG + SMA sessions (1 month apart) to stimulate tissue regeneration. Er:YAG laser emits wavelength at 2,940 nm and when combined with SMA, a resonance effect is produced in the dermis to promote tissue regeneration. Facial skin elasticity and firmness were objectively assessed by Cutometer at baseline and month 6 (M6). Aesthetic improvement was qualitatively assessed using digital photographs. Patient satisfaction with regard to their facial appearance was self-assessed using the validated FACE-Q scale and the patient-perceived age VAS scale at baseline, M1, and M6. Side effects were investigated after each session. Thirty-four patients were included, 50% (18 patients) had Fitzpatrick skin type III and 41% (14 patients) were smokers. Skin elasticity indices were significantly improved: from 0.335 ± 0.015 at baseline to 0.387 ± 0.021 at M6 (P = 0.05*) for R5 (net elasticity). Skin firmness was assessed through R7 (biological elasticity) and R6 (viscoelastic ratio) at baseline and M6: a significant increase from 0.235 ± 0.01 to 0.2709 ± 0.009 (P technology offers an effective and safe treatment alternative for facial skin rejuvenation. It reduces the recovery time compared to conventional lasers such as carbon dioxide laser. Lasers Surg. Med. 49:78-83, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Femtosecond-laser assisted cell reprogramming

Science.gov (United States)

Breunig, Hans Georg; Uchugonova, Aisada; Batista, Ana; König, Karsten

2017-02-01

Femtosecond-laser pulses can assist to transfect cells by creating transient holes in the cell membrane, thus making them temporarily permeable for extraneous genetic material. This procedure offers the advantage of being completely "virus free" since no viruses are used for the delivery and integration of gene factors into the host genome and, thereby, avoiding serious side effects which so far prevent clinical application. Unfortunately, focusing of the laser radiation onto individual cell membranes is quite elaborate and time consuming. Regarding these obstacles, we briefly review two optical setups for fast, efficient and high throughput laser-assisted cell transfection based on femtosecond laser pulse excitation. The first setup aims at assisting the transfection of adherent cells. It comprises of a modified laser-scanning microscope with beamshaping optics as well as home-made software to automate the detection, targeting and laser-irradiation process. The second setup aims at laser-assisted transfection of non-adherent cells in suspension which move in a continuous flow through the laser focus region. The setup allows to address a large number of cells, however, with much lower transfection efficiency than the individual-cell targeting approach.

Transcanalicular laser-assisted dacryocystorhinostomy.

Science.gov (United States)

Rosen, N; Barak, A; Rosner, M

1997-09-01

Current techniques of laser-assisted dacryocystorhinostomy are mostly endonasal. In this report, the authors describe their technique of laser-assisted dacryocystorhinostomy performed through the canaliculi and the surgical results they achieved. Fourteen patients with nasolacrimal duct obstruction underwent transcanalicular laser-assisted dacryocystorhinostomy. The bony ostium was perforated using a fiber optic-transmitting, giant-pulse Nd:YAG laser, with an energy of 0.5 to 4 J per pulse. The total energy used to create an ostium was 18 to 34 J. A silicone tube was inserted through the canaliculi and the ostium into the nasal cavity and kept in place for 5 to 7 months. Patients were observed for 18 to 22 months. Nine of the 14 patients (64%) reported the disappearance of epiphora following surgery. In 3 patients, no relief of epiphora was obtained. In 1 patient the operation was not completed because of severe nasal bleeding. In another, tearing began 12 months after surgery (6 months after tube removal). Transcanalicular laser-assisted dacryocystorhinostomy is a potentially useful method for performing dacryocystorhinostomy. Technical modifications and improvements are needed to increase the success rate.

Facial recognition and laser surface scan: a pilot study

DEFF Research Database (Denmark)

Lynnerup, Niels; Clausen, Maja-Lisa; Kristoffersen, Agnethe May

2009-01-01

Surface scanning of the face of a suspect is presented as a way to better match the facial features with those of a perpetrator from CCTV footage. We performed a simple pilot study where we obtained facial surface scans of volunteers and then in blind trials tried to match these scans with 2D...... photographs of the faces of the volunteers. Fifteen male volunteers were surface scanned using a Polhemus FastSCAN Cobra Handheld Laser Scanner. Three photographs were taken of each volunteer's face in full frontal, profile and from above at an angle of 45 degrees and also 45 degrees laterally. Via special...

367 cases of CO2 laser therapy on facial acne

Science.gov (United States)

Gao, Yunqing; Liu, Songhao; Zhang, You; Liu, T. C.

1996-09-01

Since 1989, we have cured 367 persons of facial acne of different course by using direct irradiation of high-power CO2 laser combing with operative therapy of low-power CO2 laser. The cure rate is 100 percent. In this paper, we stated the therapeutic approach. It was shown that this therapeutic approach is simple and effective, and its recurrence rate is zero. There are no cicatrices after healing. It is easy to accept it, and is worthy of extension.

Male Body Contouring.

Science.gov (United States)

Singh, Babu; Keaney, Terrence; Rossi, Anthony M

2015-09-01

Men are increasingly turning to dermatologists and plastic surgeons to request procedures that correct or enhance physical features. With the advent of this emerging new patient population, alterations in preexisting aesthetic techniques, gender-specific uses of existing devices and overall approaches need to be revisited and adapted to obtain results that are suitable for the male patient. Recently, body contouring has become one of the most sought out procedures by men. Although the majority of clinical studies involving body contouring esthetics are performed with female patients, gains from such studies can be extrapolated to men. Body contouring can be broadly classified as non-invasive or invasive, depending on the modality used. Non-invasive contouring is most frequently performed with devices that target subcutaneous adipose with focused electrical or thermal energy, including low-level laser, cryolipolysis, ultrasonography, and radiofrequency. Invasive body contouring modalities useful for male body contouring include liposuction, pectoral and abdominal wall etching, jawline fillers, synthetic deoxycholic acid injections, and solid silicone implants. The purpose of this review is to bring attention to the unique aspects, strategies, and modalities used in aesthetic body contouring for the male patient.

21 CFR 884.6200 - Assisted reproduction laser system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a device...

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.

A pilot study of the efficacy of the POLARGEN® ultrahigh-frequency electric field (40.68 MHz) radiofrequency device in the treatment of facial contouring.

Science.gov (United States)

Kim, Miri; Lim, Jihong; Bae, Jung Min; Park, Hyun Jeong

2017-11-01

Various radiofrequency (RF) devices are used to treat skin laxity and face contouring, but few studies have examined ultrahigh-frequency (UHF) electric field (40.68 MHz) RF devices. To evaluate the efficacy and safety of a UHF electric field (40.68 MHz) RF device for skin tightening and face contouring. Ten patients each underwent four sessions of UHF electric field RF device treatment at 2-week intervals. Clinical improvement was evaluated with the patient satisfaction score using a six-point scale, and clinical photographs taken at every visit and 2 months after the RF treatment were assessed. Skin biopsies were obtained from one patient before the first treatment and immediately after the last treatment. Adverse reactions were recorded at every follow-up visit. All patients were women with a mean age of 51.7 ± 7.2 years. The mean satisfaction score was 4.5 ± 0.9 immediately after the last treatment session. Cheek, jawline, and neck enhancement and tightening were apparent in all patients. Side effects were minimal, and there were no burns or major complications. The UHF electric field RF device was effective for skin tightening and facial contouring, without significant adverse reactions.

Relationship between the shape of the upper central incisors and the facial contour in dental students. Lima. Peru.

Directory of Open Access Journals (Sweden)

Miguel Cabello

2015-06-01

Full Text Available Determine the relationship between the shape of the face and the shape of the upper right central incisor according to “The law of harmony” proposed by Williams. Materials and methods: This was an observational, analytic and cross-sectional study. A sample of 124 subjects, male and female students between 17 and 28 years old, was selected for the research. Their facial biotype and the shape of their upper right central incisor were determined by means of direct and photographic methods. Height and facial width were clinically evaluated using the direct method, and the proximal contours of the incisors were evaluated using a Vernier digital caliper. Images were downloaded to a computer and analyzed by means of the photographic method using Adobe Photoshop 5.0. Results: The relationship between the shape of the face and the shape of the incisor was positive in 43.5% of the sample (p=0.006 in the direct method. In the photographic method, the relationship between the shape of the face and the shape of the incisor was positive in 41.1% of the sample (p=0.037. The most frequent facial biotype in the direct and photographic methods was the dolichofacial with 61.3% and 71% respectively. The most frequent shape of the tooth with the direct and photographic methods was the ovoid with 55.6% and 51.6% respectively. Conclusion: Results do not confirm “The law of harmony” proposed by Williams, therefore when choosing the most suitable anterior tooth, experience and criteria of the dentist as well as the opinion of the patient should be taken in account in order to achieve a good aesthetic result.

Efficacy of Laser Photobiomodulation on Morphological and Functional Repair of the Facial Nerve.

Science.gov (United States)

Buchaim, Daniela Vieira; Andreo, Jesus Carlos; Ferreira Junior, Rui Seabra; Barraviera, Benedito; Rodrigues, Antonio de Castro; Macedo, Mariana de Cássia; Rosa Junior, Geraldo Marco; Shinohara, Andre Luis; Santos German, Iris Jasmin; Pomini, Karina Torres; Buchaim, Rogerio Leone

2017-08-01

Evaluate the efficacy of low-level laser therapy (LLLT) on qualitative, quantitative, and functional aspects in the facial nerve regeneration process. Forty-two male Wistar rats were used, randomly divided into a control group (CG; n = 10), in which the facial nerve without lesion was collected, and four experimental groups: (1) suture experimental group (SEG) and (2) fibrin experimental group (FEG), consisting of 16 animals in which the buccal branch of the facial nerve was sectioned on both sides of the face; an end-to-end epineural suture was performed on the right side, and a fibrin sealant was used on the left side for coaptation of the stumps; and (3) laser suture experimental group (LSEG) and (4) laser fibrin experimental group (LFEG), consisting of 16 animals that underwent the same surgical procedures as SEG and FEG with the addition of laser application at three different points along the surgical site (pulsed laser of 830 nm wavelength, optical output power of 30 mW, power density of 0.2586 W/cm 2 , energy density of 6.2 J/cm 2 , beam area of 0.116 cm 2 , exposure time of 24 sec per point, total energy per session of 2.16 J, and cumulative dose of 34.56 J). The animals were submitted to functional analysis (subjective observation of whisker movement) and the data obtained were compared using Fisher's exact test. Euthanasia was performed at 5 and 10 weeks postoperative. The total number and density of regenerated axons were analyzed using the unpaired t-test (p < 0.05). Laser therapy resulted in a significant increase in the number and density of regenerated axons. The LSEG and LFEG presented better scores in functional analysis in comparison with the SEG and FEG. LLLT enhanced axonal regeneration and accelerated functional recovery of the whiskers, and both repair techniques allowed the growth of axons.

Effects of various parameters of the 1064 nm Nd:YAG laser for the treatment of enlarged facial pores.

Science.gov (United States)

Roh, Mi Ryung; Chung, Hye Jin; Chung, Kee Yang

2009-01-01

A variety of treatment modalities have been used to reduce the size of enlarged facial pores without obvious success. To assess and compare the effects of various parameters of a 1064 nm Nd:YAG laser in the treatment of enlarged facial pores. This was a prospective intra-individual left-right comparative study. A total of 40 individuals with enlarged facial pores were recruited for this study. Ten individuals were respectively treated on one half of the face with a quasi long-pulsed 1064 nm Nd:YAG laser (method 1), a Q-switched 1064 nm Nd:YAG laser (method 2), both quasi long-pulsed and Q-switched 1064 nm Nd:YAG lasers without carbon-suspended lotion (method 3), and both quasi long-pulsed and Q-switched 1064 nm Nd:YAG lasers with carbon-suspended lotion (method 4). The other half of the face was left untreated as a control. Five laser sessions were performed with a 3-week interval. The pore sizes were measured using an image analysis program and the sebum level was measured with a Sebumeter before and after the treatments. The pore size and sebum level decreased in all four methods on the treated side compared to the control (p pore size and sebum level.

Respiratory complications after diode-laser-assisted tonsillotomy.

Science.gov (United States)

Fischer, Miloš; Horn, Iris-Susanne; Quante, Mirja; Merkenschlager, Andreas; Schnoor, Jörg; Kaisers, Udo X; Dietz, Andreas; Kluba, Karsten

2014-08-01

Children with certain risk factors, such as comorbidities or severe obstructive sleep apnea syndrome (OSAS) are known to require extended postoperative monitoring after adenotonsillectomy. However, there are no recommendations available for diode-laser-assisted tonsillotomy. A retrospective chart review of 96 children who underwent diode-laser-assisted tonsillotomy (07/2011-06/2013) was performed. Data for general and sleep apnea history, power of the applied diode-laser (λ = 940 nm), anesthesia parameters, the presence of postoperative respiratory complications and postoperative healing were evaluated. After initially uncomplicated diode-laser-assisted tonsillotomy, an adjustment of post-anesthesia care was necessary in 16 of 96 patients due to respiratory failure. Respiratory complications were more frequent in younger children (3.1 vs. 4.0 years, p = 0.049, 95 % CI -1.7952 to -0.0048) and in children who suffered from nocturnal apneas (OR = 5.00, p diode-laser power higher than 13 W could be identified as a risk factor for the occurrence of a postoperative oropharyngeal edema (OR = 3.45, p diode-laser-assisted tonsillotomy. We recommend a reduced diode-laser power (<13 W) to reduce oropharyngeal edema.

The 808 nm Laser-Assisted Surgery as an Adjunct to Orthodontic Treatment of Delayed Tooth Eruption.

Science.gov (United States)

Seifi, Massoud; Vahid-Dastjerdi, Elahe; Ameli, Nazila; Badiee, Mohammad-Reza; Younessian, Farnaz; Amdjadi, Parisa

2013-01-01

Failure of teeth to erupt from gingival tissues at usual developmental time is called delayed tooth eruption (DTE). Delayed tooth eruption lead to prolonged fixed orthodontic treatment and its eventual complications. The purpose of the present study was to evaluate the effect of laser-assisted (808 nm) surgical uncovering, on the tooth emergence and orthodontic treatment of DTE. A total of 16 orthodontic patients were included in this study and were equally assigned to an experimental and a control group. Subjects for experiment consisted of eight patients (6 girls and 2 boys) with a mean age of 14±0.9 years. All patients exhibited delayed second premolar eruption. The laser wavelength was 810 nm and it was set in a continuous wave mode at a power output of 1.6 watt with a 0.3-mm diameter fiber tip. When the target tissue was sufficiently anesthetized, the tip was directed at an angle of 10 to 20 degrees to the tissue (light contact mode); and was applied continuously for approximately 12 Seconds until an acceptable tooth exposure area was visible. The facial axis of the clinical crown (FACC) line represents the most prominent portion of the facial central lobe for premolars. All orthodontic brackets are aligned along this reference and are located on FA (Facial Axis) point. The standard for adequate tooth eruption was the accessibility of facial axis of the clinical crown (FACC) for bonding the brackets. Data gathered from the patients were statistically surveyed and compared by means of Tukey's Test and Analysis of Variance (ANOVA). All patients showed good gingival status, no significant bleeding during or immediately after the surgery, and acceptable level of healing after laser surgery. The biologic width of the teeth was preserved and no violation of this important periodontal parameter was observed. The average time for accessing the FA point in experimental group was 11±1.1 weeks and the mentioned period was increased to 25±1.8 weeks in control group

Fractional versus ablative erbium:yttrium-aluminum-garnet laser resurfacing for facial rejuvenation: an objective evaluation.

Science.gov (United States)

El-Domyati, Moetaz; Abd-El-Raheem, Talal; Abdel-Wahab, Hossam; Medhat, Walid; Hosam, Wael; El-Fakahany, Hasan; Al Anwer, Mustafa

2013-01-01

Laser is one of the main tools for skin resurfacing. Erbium:yttrium-aluminum-garnet (Er:YAG) was the second ablative laser, after carbon dioxide, emitting wavelength of 2940 nm. Fractional laser resurfacing has been developed to overcome the drawbacks of ablative lasers. We aimed to objectively evaluate the histopathological and immunohistochemical effects of Er:YAG 2940-nm laser for facial rejuvenation (multiple sessions of fractional vs single session of ablative Er:YAG laser). Facial resurfacing with single-session ablative Er:YAG laser was performed on 6 volunteers. Another 6 were resurfaced using fractional Er:YAG laser (4 sessions). Histopathological (hematoxylin-eosin, orcein, Masson trichrome, and picrosirius red stains) and immunohistochemical assessment for skin biopsy specimens were done before laser resurfacing and after 1 and 6 months. Histometry for epidermal thickness and quantitative assessment for neocollagen formation; collagen I, III, and VII; elastin; and tropoelastin were done for all skin biopsy specimens. Both lasers resulted in increased epidermal thickness. Dermal collagen showed increased neocollagen formation with increased concentration of collagen types I, III, and VII. Dermal elastic tissue studies revealed decreased elastin whereas tropoelastin concentration increased after laser resurfacing. Neither laser showed significant difference between their effects clinically and on dermal collagen. Changes in epidermal thickness, elastin, and tropoelastin were significantly more marked after ablative laser. The small number of patients is a limitation, yet the results show significant improvement. Multiple sessions of fractional laser have comparable effects to a single session of ablative Er:YAG laser on dermal collagen but ablative laser has more effect on elastic tissue and epidermis. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Diode laser (980nm) cartilage reshaping

Science.gov (United States)

El Kharbotly, A.; El Tayeb, T.; Mostafa, Y.; Hesham, I.

2011-03-01

Loss of facial or ear cartilage due to trauma or surgery is a major challenge to the otolaryngologists and plastic surgeons as the complicated geometric contours are difficult to be animated. Diode laser (980 nm) has been proven effective in reshaping and maintaining the new geometric shape achieved by laser. This study focused on determining the optimum laser parameters needed for cartilage reshaping with a controlled water cooling system. Harvested animal cartilages were angulated with different degrees and irradiated with different diode laser powers (980nm, 4x8mm spot size). The cartilage specimens were maintained in a deformation angle for two hours after irradiation then released for another two hours. They were serially measured and photographed. High-power Diode laser irradiation with water cooling is a cheep and effective method for reshaping the cartilage needed for reconstruction of difficult situations in otorhinolaryngologic surgery. Key words: cartilage,diode laser (980nm), reshaping.

Advanced Laser Techniques for Filler-Induced Complications

DEFF Research Database (Denmark)

Cassuto, D.; Marangoni, O.; Santis, G. De

2009-01-01

discomfort and pain. RESULTS All 20 patients experienced reduction or complete resolution, the latter increasing with repeated treatments. CONCLUSION Laser-assisted treatment offers a successful solution for patients who have been suffering from disfiguring nodules from injected fillersFoften for many years......BACKGROUND The increasing use of injectable fillers has been increasing the occurrence of disfiguring anaerobic infection or granulomas. This study presents two types of laser-assisted evacuation of filler material and inflammatory and necrotic tissue that were used to treat disfiguring facial...... nodules after different types of gel fillers. MATERIALS AND METHODS Infectious lesions after hydrogels were drained using a lithium triborate laser at 532 nm, with subsequent removal of infected gel and pus (laser assisted evacuation). Granuloma after gels containing microparticles were treated using...

Effects of Q-switched and long-pulsed 1064 nm Nd:YAG laser on enlarged facial pores.

Science.gov (United States)

Lee, Chang Nam; Kim, You Jeong; Lee, Hyun Seung; Kim, Hei Sung

2009-12-01

'Enlarged facial pore' is a subjective term, which is not clearly defined but often complained by many. A diverse range of treatments are used though evidence of efficacy remains largely anecdotal. We report a series of nine patients who underwent a split face trial with Q-switched 1064 nm Nd:YAG and long-pulsed 1064 nm Nd:YAG laser to treat enlarged facial pores.

On Assisting a Visual-Facial Affect Recognition System with Keyboard-Stroke Pattern Information

Science.gov (United States)

Stathopoulou, I.-O.; Alepis, E.; Tsihrintzis, G. A.; Virvou, M.

Towards realizing a multimodal affect recognition system, we are considering the advantages of assisting a visual-facial expression recognition system with keyboard-stroke pattern information. Our work is based on the assumption that the visual-facial and keyboard modalities are complementary to each other and that their combination can significantly improve the accuracy in affective user models. Specifically, we present and discuss the development and evaluation process of two corresponding affect recognition subsystems, with emphasis on the recognition of 6 basic emotional states, namely happiness, sadness, surprise, anger and disgust as well as the emotion-less state which we refer to as neutral. We find that emotion recognition by the visual-facial modality can be aided greatly by keyboard-stroke pattern information and the combination of the two modalities can lead to better results towards building a multimodal affect recognition system.

The asymmetric facial skin perfusion distribution of Bell's palsy discovered by laser speckle imaging technology.

Science.gov (United States)

Cui, Han; Chen, Yi; Zhong, Weizheng; Yu, Haibo; Li, Zhifeng; He, Yuhai; Yu, Wenlong; Jin, Lei

2016-01-01

Bell's palsy is a kind of peripheral neural disease that cause abrupt onset of unilateral facial weakness. In the pathologic study, it was evidenced that ischemia of facial nerve at the affected side of face existed in Bell's palsy patients. Since the direction of facial nerve blood flow is primarily proximal to distal, facial skin microcirculation would also be affected after the onset of Bell's palsy. Therefore, monitoring the full area of facial skin microcirculation would help to identify the condition of Bell's palsy patients. In this study, a non-invasive, real time and full field imaging technology - laser speckle imaging (LSI) technology was applied for measuring facial skin blood perfusion distribution of Bell's palsy patients. 85 participants with different stage of Bell's palsy were included. Results showed that Bell's palsy patients' facial skin perfusion of affected side was lower than that of the normal side at the region of eyelid, and that the asymmetric distribution of the facial skin perfusion between two sides of eyelid is positively related to the stage of the disease (P Bell's palsy patients, and we discovered that the facial skin blood perfusion could reflect the stage of Bell's palsy, which suggested that microcirculation should be investigated in patients with this neurological deficit. It was also suggested LSI as potential diagnostic tool for Bell's palsy.

Prospective study on laser-assisted laparascopic partial nephrectomy

Science.gov (United States)

Sroka, Ronald; Hennig, Georg; Zilinberg, Katja; Khoder, Wael Y.

2012-02-01

Introduction: Developments in laparoscopic partial nephrectomy (LPN) opened a demand for surgical tools compatible with laparoscopic manipulations to make laser assisted technique safe, feasible and reproducible. Warm ischemia and bleeding during laparoscopic partial nephrectomy place technical constraints on surgeons. Therefore it was the aim to develop a safe and effective laser assisted partial nephrectomy technique without need for ischemia. Patients and methods: A diode laser emitting light at 1318nm in cw mode was coupled into a bare fibre (core diameter 600 μm) thus able to transfer up to 100W to the tissue. After dry lab experience, a total of 10 patients suffering from kidney malformations underwent laparoscopic/retroperitoneoscopic partial nephrectomy. Clinically, postoperative renal function and serum c-reactive protein (CRP) were monitored. Laser induced coagulation depth and effects on resection margins were evaluated. Demographic, clinical and follow-up data are presented. Using a commercial available fibre guidance instrument for lanringeal intervention, the demands on an innovative laser fibre guidance instrument for the laser assisted laparoscopic partial nephrectomy (LLPN) are summarized. Results: Overall, all laparascopic intervention were succesfull and could be performed without conversion to open surgery. Mean operative time and mean blood loss were comparable to conventional open and laparascopic approaches. Laser assisted resection of the kidney tissue took max 15min. After extirpation of the tumours all patients showed clinical favourable outcome during follow up period. Tumour sizes were measured to be up 5cm in diameter. The depth of the coagulation on the removed tissue ranged between laser assisted coagulated after removal. The sealing of the surface was induced by a slightly larger coagulation margin, but could not measured so far. Based on this experiences a simple and easy to use instrument described serving also for suction and

The Clinical Efficacy of Autologous Platelet-Rich Plasma Combined with Ultra-Pulsed Fractional CO2 Laser Therapy for Facial Rejuvenation.

Science.gov (United States)

Hui, Qiang; Chang, Peng; Guo, Bingyu; Zhang, Yu; Tao, Kai

2017-02-01

Ultra-pulsed fractional CO 2 laser is an efficient, precise, and safe therapeutic intervention for skin refreshing, although accompanied with prolonged edema and erythema. In recent years, autologous platelet-rich plasma (PRP) has been proven to promote wound and soft tissue healing and collagen regeneration. To investigate whether the combination of PRP and ultra-pulsed fractional CO 2 laser had a synergistic effect on therapy for facial rejuvenation. Totally, 13 facial aging females were treated with ultra-pulsed fractional CO 2 laser. One side of the face was randomly selected as experimental group and injected with PRP, the other side acted as the control group and was injected with physiological saline at the same dose. Comprehensive assessment of clinical efficacy was performed by satisfaction scores, dermatologists' double-blind evaluation and the VISIA skin analysis system. After treatment for 3 months, subjective scores of facial wrinkles, skin texture, and skin elasticity were higher than that in the control group. Similarly, improvement of skin wrinkles, texture, and tightness in the experimental group was better compared with the control group. Additionally, the total duration of erythema, edema, and crusting was decreased, in the experimental group compared with the control group. PRP combined with ultra-pulsed fractional CO 2 laser had a synergistic effect on facial rejuvenation, shortening duration of side effects, and promoting better therapeutic effect.

Assisting Gas Optimization in CO2 Laser Welding

DEFF Research Database (Denmark)

Gong, Hui; Olsen, Flemming Ove

1996-01-01

High quality laser welding is achieved under the condition of optimizing all process parameters. Assisting gas plays an important role for sound welds. In the conventional welding process assisting gas is used as a shielding gas to prevent that the weld seam oxidates. In the laser welding process...... assisting gas is also needed to control the laser induced plasma.Assisting gas is one of the most important parameters in the laser welding process. It is responsible for obtaining a quality weld which is characterized by deep penetration, no interior imperfections, i.e. porosity, no crack, homogeneous seam...... surface, etc. In this work a specially designed flexible off-axis nozzle capable of adjusting the angle of the nozzle, the diameter of the nozzle, and the distance between the nozzle end and the welding zone is tested. In addition to the nozzle parameters three gases, Nitrogen, Argon, and Helium...

Electro therapy facial and laser skin whitening: Clients' perspective.

Science.gov (United States)

Lavanya, D; Manimaran, S; Bhagyalakshmi, K

2018-01-01

There are so many beauty salons in Metropolis who provide services to women exclusively [1]. These beauty salons depend mostly on electricity for their services to customers, without it there is no effective means of operation [2]. These beauty salons are definitely leading to women empowerment. The beauty salons are run by the women for women. Since they fall under the category of micro and small enterprises, these salons may avail so many financial and non- financial advantages from the Government of India. They also provide employment opportunities to the women employees. The development of such beauty salons rests on the clients' satisfaction on the provision of their services. Hence it is essential to measure the clients attitude towards the services offered by the beauty salons, especially electro therapy facial, laser skin whitening and laser hair removal treatments, which are coming under micro current treatment as a cosmetic tool.

Efficacy and safety of fractional carbon dioxide laser for treatment of unwanted facial freckles in phototypes II-IV: a pilot study.

Science.gov (United States)

El Zawahry, Bakr; Zaki, Naglaa; Hafez, Vanessa; Abdel Hay, Rania; Hay, Rania Abdel; Fahim, Aya

2014-11-01

Facial freckles are a cosmetic concern to Egyptians, particularly young females. Several therapeutic lines exist with variable response rates and limitations. Fractional carbon dioxide (FCO2) laser provides minimal ablation and therefore less down time and less side effects. The efficacy and safety of this laser technology have still not been studied in freckles. The aim of this study is to assess the efficacy and safety of FCO2 laser in the treatment of unwanted facial freckles in Egyptians. Twenty patients undergone a single session of FCO2 laser and then were followed up clinically a month later. Photographs were taken before treatment and at follow-up visit and were assessed by three blinded investigators. Percent of global improvement was measured on a 4-point grading scale. Patient's satisfaction and adverse events were recorded. Two patients (10 %) showed grade 1 improvement, while eight patients (40 %) showed grade 2 improvement. Nine patients (45 %) showed grade 3 improvement, and only one patient (5 %) showed grade 4 improvement. FCO2 laser resurfacing is effective and safe in treatment of facial freckles in skin phototypes II-IV. It can offer a more practical alternative to topical treatments, and a cheaper alternative to Q-switched lasers.

Combined Use of Facial Osteoplasty and Orthognathic Surgery for Treatment of Dentofacial Deformities.

Science.gov (United States)

Li, Yunfeng; Hu, Zhiai; Ye, Bin; Liu, Yao; Ren, Xiaochun; Zhu, Songsong

2016-12-01

Orthognathic surgery is an efficient procedure for cosmetic and functional aims. However, when functional improvement is achieved by mandibular or maxillary operations, additional esthetic corrections may be imperative for some patients. This study aims to introduce our primary practice of simultaneous facial bone contouring and orthognathic surgery for esthetic reasons. Ten patients with dentofacial deformities as well as a prominent angle, asymmetric deformities, or a high zygoma and zygomatic arch were recruited from West China Hospital of Stomatology, Sichuan University (Chengdu, China), between January 1, 2014, and July 31, 2015. Traditional orthognathic surgical procedures such as bilateral sagittal split osteotomy and Le Fort I osteotomy combined with facial osteoplasty including mandibular angle ostectomy, outer cortex ostectomy of the mandibular angle, and zygoma and zygomatic arch reduction were performed. Radiographs and medical photographs were taken before and after surgery to compare the effectiveness of the combined use of facial osteoplasty and orthognathic surgery. All patients had an uneventful postoperative recovery, with no signs of infection, jaw displacement, or osteonecrosis. Radiographs taken 1 week after surgery and pictures of the facial profile and occlusion taken 6 months after surgery showed satisfactory esthetic outcomes. All patients were satisfied with the functional and cosmetic results. This study indicated the clinical feasibility of simultaneous facial bone contouring and orthognathic surgery for the treatment of dentofacial deformities. Simultaneous facial bone contouring seems to be an alternative procedure in addition to conventional orthognathic surgery for cosmetic aims in certain patients. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

SPF-RR sequential photothermal fractional resurfacing and remodeling with the variable pulse Er:YAG laser and scanner-assisted Nd:YAG laser.

Science.gov (United States)

Marini, Leonardo

2009-12-01

Many different lasers, polychromatic high-intensity light sources (PCLs), and RF devices have claimed clinical efficacy in rejuvenating the skin. In this study, the sequential combination of two different laser wavelengths was evaluated to produce reliably significant clinical improvements optimizing treatment parameters. The left volar aspects of the forearms of four volunteers were treated with nine different parameter settings using a variable pulsewidth fractional Er:YAG 2940-nm laser with and without air cooling. The pain perception level was recorded on a 0-10 point scale (0=No pain; 10=Most severe pain). Three evaluations were made: during treatment, immediately after treatment, and 5 minutes after treatment. The same investigation was made on the right volar aspects of the same four volunteers using a short-pulse, random pattern, 3-mm spot, scanner-assisted Nd-YAG 1064-nm laser at 0.3 ms pulsewidth at seven different parameter settings. Clinical evaluations were made concerning erythema and edema 3 days after treatment, as well as pre-operative and 60 days postoperative skin texture plus color uniformity. Considering that the majority of cosmetic patients are willing to accept a relatively short and uneventful downtime (2-4 days according to a study we are presently conducting) and do prefer to limit their intra- and postoperative pain to a minimum, the best combination of clinical improvement matching these two important parameters were selected for our study. A treatment strategy combining two sequential passes of long-pulse Nd:YAG laser (Nd:YAG-LP) at 0.3 and 35 ms followed by two passes of long-pulse fractional Er:YAG laser (Er:YAG-FT) at 600 micros was designed to treat the facial regions of 10 volunteers affected by a combination of intrinsic (chrono-) and extrinsic (mostly photo-) aging. The pain perception level was recorded on a 0-10 scale (0=No pain; 10=Most severe pain). Three evaluations were made: during, immediately after, and 5 minutes after

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

Science.gov (United States)

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

2011-07-01

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

Laser assisted hybrid additive manufacturing of thermoelectric modules

Science.gov (United States)

Zhang, Tao; Tewolde, Mahder; Longtin, Jon P.; Hwang, David J.

2017-02-01

Thermoelectric generators (TEGs) are an attractive means to produce electricity, particular from waste heat applications. However, TEGs are almost exclusively manufactured as flat, rigid modules of limited size and shape, and therefore an appropriate mounting for intimate contact of TEGs modules onto arbitrary surfaces represents a significant challenge. In this study, we introduce laser assisted additive manufacturing method to produce multi-layered thermoelectric generator device directly on flat and non-flat surfaces for waste heat recovery. The laser assisted processing spans from laser scribing of thermal sprayed thin films, curing of dispensed thermoelectric inks and selective laser sintering to functionalize thermoelectric materials.

Evaluation of a Low Energy, Low Density, Non-Ablative Fractional 1927 nm Wavelength Laser for Facial Skin Resurfacing.

Science.gov (United States)

Brauer, Jeremy A; Alabdulrazzaq, Hamad; Bae, Yoon-Soo Cindy; Geronemus, Roy G

2015-11-01

We investigated the safety, tolerability and efficacy of a low energy low density, non-ablative fractional 1,927-nm laser in the treatment of facial photodamage, melasma, and post inflammatory hyperpigmentation. Prospective non-randomized trial. Single center, private practice with a dedicated research department. Subjects with clinically diagnosed facial photodamage, melasma, or post inflammatory hyperpigmentation. Subjects received four to six treatments at 14-day intervals (+/- 3 days) with a low energy low density non-ablative fractional 1,927-nm laser (Solta Hayward, CA) with an energy level of 5 mJ, and density coverage of either 5%, 7.5%, or 10%, with a total of up to 8 passes. Blinded assessment of clinical photos for overall improvement at one and three months post final treatment. Investigator improvement scores, and subject pain and satisfaction scores for overall improvement were recorded as well. We enrolled 23 subjects, average age 45.0 years (range, 25-64 years), 22 with Fitzpatrick Skin Types I-IV and 1 with Type VI, with facial photodamage, melasma, or post inflammatory hyperpigmentation. Approximately 55% of subjects reported marked to very significant improvement at one and three months post final treatment. Blinded assessment of photography of 20 subjects revealed an average of moderate improvement at one-month follow up and mild to moderate improvement at three months. Average subject pain score was 3.4/10 during treatment. Favorable outcomes were demonstrated using the low energy low density, non-ablative fractional 1,927-nm laser in facial resurfacing for photodamage, melasma, and post inflammatory hyperpigmentation. Results were maintained at the 3-month follow up, as demonstrated by investigator and subject assessments, as well as blinded evaluations by three independent dermatologists utilizing photographs obtained from a standardized facial imaging device.

Fundamentals of laser-assisted fabrication of inorganic and organic films

DEFF Research Database (Denmark)

Schou, Jørgen

2008-01-01

The standard method for producing films by laser-assisted methods, Pulsed Laser Deposition (PLD) will be reviewed. The films considered are usually inorganic films, but also films of organic materials have been produced. Also the deposition of organic films by MAPLE (Matrix Assisted Pulsed Laser...

Restoring facial shape in face lifting: the role of skeletal support in facial analysis and midface soft-tissue repositioning.

Science.gov (United States)

Stuzin, James M

2007-01-01

Aesthetic analysis in facial rejuvenation has traditionally been subordinate to technical solutions. While concerns regarding correction of facial laxity, a reduction in the depth of the nasolabial fold, and improvement of both the jowl and the jawline are worthy goals in rhytidectomy, the aesthetic concept of restoring facial shape to a more youthful appearance is equally important. Restoring facial shape in face lifting requires an understanding of how the face ages and then the formulation of a treatment plan that is individualized for the patient. Re-establishment of facial contour is significantly influenced by the re-elevation of descended facial fat through superficial musculoaponeurotic system manipulation; it can be approached through a variety of technical solutions. Underlying skeletal support affects not only the appearance of the face in youth but also how the face ages and influences the operative plan in terms of the requirements for fat repositioning. Formulating a treatment plan that is patient specific and based on the artistic goals as influenced by skeletal support is the key element for consistency in restoring facial shape in face lifting.

The efficacy of autologous platelet-rich plasma combined with erbium fractional laser therapy for facial acne scars or acne.

Science.gov (United States)

Zhu, Jiang-Ting; Xuan, Min; Zhang, Ya-Ni; Liu, Hong-Wei; Cai, Jin-Hui; Wu, Yan-Hong; Xiang, Xiao-Fei; Shan, Gui-Qiu; Cheng, Biao

2013-07-01

The aim of this study was to evaluate the efficacy of autologous platelet-rich plasma (PRP) combined with erbium fractional laser therapy for facial acne or acne scars. PRP combined with erbium fractional laser therapy was used for the treatment of 22 patients, including 16 patients who suffered from facial acne scars and 6 patients who suffered from acne scars concomitant with acne. Whole blood (40 ml) was collected from each patient, and following differential centrifugation, PRP was harvested. After using an erbium fractional laser, we applied PRP to the entire face of every patient. Digital photos were taken before and after the treatment for evaluation by dermatologists and the patients rated the efficacy on a 5-point scale. The erythema was moderate or mild, while its total duration was 50%, and 91% of the patients were satisfied; no acne inflammation was observed after treatment. PRP combined with erbium fractional laser therapy is an effective and safe approach for treating acne scars or acne, with minimal side-effects, and it simultaneously enhanced the recovery of laser-damaged skin.

Redefining face contour with a novel anti-aging cosmetic product: an open-label, prospective clinical study

Directory of Open Access Journals (Sweden)

Garre A

2017-11-01

Full Text Available Aurora Garre,1 Gemma Martinez-Masana,1 Jaime Piquero-Casals,2 Corinne Granger1 1Innovation and Development, ISDIN S.A., Barcelona, Spain; 2Dermik Clinic, Barcelona, Spain Background: Skin aging is accelerated by multiple extrinsic factors: ultraviolet radiation, smoking and pollution increase oxidative activity, damaging cellular and extracellular components such as DNA, proteins, and lipids. With age, collagen and hyaluronic acid levels decline, resulting in loss of elasticity and moisture of the skin. Over time this damage leads to characteristic signs that make the skin look older: altered facial contour, sagging skin, wrinkles, and an uneven complexion. This study evaluated the anti-aging effects of a new facial cream formulated with carnosine, Alteromonas ferment extract, crosspolymer hyaluronic acid, and a tripeptide. Methods: An open-label intra-individual study to assess the anti-aging efficacy of the investigational product in 33 women aged 45 to 65 years. The product was applied twice daily for 56 days. Facial contour and skin deformation, elasticity, hydration, and complexion were measured with specialized equipment at baseline and days 28 and 56. Additionally, subjects completed questionnaires at days 28 and 56 on the perceived efficacy and cosmetic characteristics of the product. Results: After 56 days of use of the investigational product, a redefining effect was observed, with a significant decrease in sagging jawline (7%. Skin was significantly more hydrated (12%, firmer (29%, and more elastic (20% (P<0.001 for all. On complexion assessment, skin texture (a measure of skin smoothness and spots (brown and red skin lesions also improved significantly (12% and 6% decrease, respectively. In the subjective self-evaluation, the majority of subjects reported that the skin was visibly tightened and more elastic, flexible, and moisturized (91%, 88%, 91%, and 90%, respectively. The product was well tolerated with no adverse events reported

Long-pulsed Nd: YAG laser and intense pulse light-755 nm for idiopathic facial hirsutism: A comparative study

Directory of Open Access Journals (Sweden)

Arpit Shrimal

2017-01-01

Full Text Available Background: Hirsutism means excessive terminal hair growth in a female in male pattern distribution. Perception of hirsutism is subjective. Permanent laser hair reduction is a slow process taking many sessions and tracking of improvement parameters is tedious. Hence, a lot of confusion still exists regarding the type of laser most beneficial for treatment. Aim: The aim of this study was to compare the effectiveness and safety profile of long-pulsed Nd: YAG laser (1064 nm and intense pulse light (IPL-755 nm in management of idiopathic facial hirsutism. Settings and Design: Open-labelled, randomly allocated experimental study. Subjects and Methods: The study included 33 cases of idiopathic facial hirsutism. Patients were randomly divided into Group A, treated with long-pulsed Nd: YAG laser and Group B, treated with IPL-755 for a total of six sessions at 1 month interval. Statistical Analysis: Chi-square test was used in Medcalc® version 9.0 and the test of significance was taken to be P75% reduction in hair after six sessions in Group A was seen in fourteen (93.33% out of fifteen patients, whereas in Group B, it was seen only in three (16.66% out of eighteen patients. In Group A, erythema was seen in 26.67%, perifollicular edema and hyperpigmentation in 13.33% each. In Group B, erythema was seen in 50% patients, perifollicular edema in 16.67% and hyperpigmentation in 38.89% patients. Conclusions: Long-pulsed Nd: YAG Laser (1064 nm is better than IPL-755 nm in terms of safety and effectiveness in the management of idiopathic facial hirsutism.

A predictive thermal dynamic model for parameter generation in the laser assisted direct write process

International Nuclear Information System (INIS)

Shang Shuo; Fearon, Eamonn; Wellburn, Dan; Sato, Taku; Edwardson, Stuart; Dearden, G; Watkins, K G

2011-01-01

The laser assisted direct write (LADW) method can be used to generate electrical circuitry on a substrate by depositing metallic ink and curing the ink thermally by a laser. Laser curing has emerged over recent years as a novel yet efficient alternative to oven curing. This method can be used in situ, over complicated 3D contours of large parts (e.g. aircraft wings) and selectively cure over heat sensitive substrates, with little or no thermal damage. In previous studies, empirical methods have been used to generate processing windows for this technique, relating to the several interdependent processing parameters on which the curing quality and efficiency strongly depend. Incorrect parameters can result in a track that is cured in some areas and uncured in others, or in damaged substrates. This paper addresses the strong need for a quantitative model which can systematically output the processing conditions for a given combination of ink, substrate and laser source; transforming the LADW technique from a purely empirical approach, to a simple, repeatable, mathematically sound, efficient and predictable process. The method comprises a novel and generic finite element model (FEM) that for the first time predicts the evolution of the thermal profile of the ink track during laser curing and thus generates a parametric map which indicates the most suitable combination of parameters for process optimization. Experimental data are compared with simulation results to verify the accuracy of the model.

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

Laser assisted tunneling in a Tonks–Girardeau gas

International Nuclear Information System (INIS)

Lelas, Karlo; Drpić, Nikola; Dubček, Tena; Buljan, Hrvoje; Jukić, Dario; Pezer, Robert

2016-01-01

We investigate the applicability of laser assisted tunneling in a strongly interacting one-dimensional (1D) Bose gas (the Tonks–Girardeau gas) in optical lattices. We find that the stroboscopic dynamics of the Tonks–Girardeau gas in a continuous Wannier–Stark-ladder potential, supplemented with laser assisted tunneling, effectively realizes the ground state of 1D hard-core bosons in a discrete lattice with nontrivial hopping phases. We compare observables that are affected by the interactions, such as the momentum distribution, natural orbitals and their occupancies, in the time-dependent continuous system, to those of the ground state of the discrete system. Stroboscopically, we find an excellent agreement, indicating that laser assisted tunneling is a viable technique for realizing novel ground states and phases with hard-core 1D Bose gases. (paper)

Parameters in fractional laser assisted delivery of topical anesthetics: Role of laser type and laser settings.

Science.gov (United States)

Meesters, Arne A; Nieboer, Marilin J; Kezic, Sanja; de Rie, Menno A; Wolkerstorfer, Albert

2018-05-07

Efficacy of topical anesthetics can be enhanced by pretreatment of the skin with ablative fractional lasers. However, little is known about the role of parameters such as laser modality and laser density settings in this technique. Aims of this study were to compare the efficacy of pretreatment with two different ablative fractional laser modalities, a CO 2 laser and an Er:YAG laser, and to assess the role of laser density in ablative fractional laser assisted topical anesthesia. In each of 15 healthy subjects, four 10 × 10 mm test regions on the back were randomized to pretreatment (70-75 μm ablation depth) with CO 2 laser at 5% density, CO 2 laser at 15% density, Er:YAG laser at 5% density or Er:YAG laser at 15% density. Articaine hydrochloride 40 mg/ml + epinephrine 10 μg/ml solution was applied under occlusion to all four test regions. After 15 minutes, a pass with the CO 2 laser (1,500 μm ablation depth) was administered as pain stimulus to each test region. A reference pain stimulus was given on unanesthetized skin. The main outcome parameter, pain, was scored on a 0-10 visual analogue scale (VAS) after each pain stimulus. Median VAS scores were 1.50 [CO 2 5%], 0.50 [CO 2 15%], 1.50 [Er:YAG 5%], 0.43 [Er:YAG 15%], and 4.50 [unanesthetized reference]. VAS scores for all pretreated test regions were significantly lower compared to the untreated reference region (P laser pretreated regions. However, VAS scores were significantly lower at 15% density compared to 5% density for both for the CO 2 laser (P laser (P laser was considered slightly more painful than pretreatment with Er:YAG laser by the subjects. Fractional laser assisted topical anesthesia is effective even with very low energy settings and an occlusion time of only 15 minutes. Both the CO 2 laser and the Er:YAG laser can be used to assist topical anesthesia although the CO 2 laser pretreatment is experienced as more painful. In our study settings, using articaine

Shearography in laser material processing

International Nuclear Information System (INIS)

Gualini, M.M.S.; Steinbichler, H.

1999-01-01

Several optical methods have been presented in recent years to monitor and assist laser material process (welding, cutting, transformation hardening), from laser triangulation and laser 3D scanning to speckle. We propose the alternative use of shearography for surface investigation. Shearography is, basically, the first derivative of the interference intensities of holograms. This enables to perform real time measurements with high accuracy but less constraint to control environmental vibrations. We propose an optical head that may operate as a shearographic system or as a Twymann-Green interferometer, accordingly to certain contour conditions. We discuss some theoretical aspects and possible practical applications of the device along with some preliminary experimental results. (author)

Missing facial parts computed by a morphable model and transferred directly to a polyamide laser-sintered prosthesis: an innovation study.

Science.gov (United States)

Mueller, A A; Paysan, P; Schumacher, R; Zeilhofer, H-F; Berg-Boerner, B-I; Maurer, J; Vetter, T; Schkommodau, E; Juergens, P; Schwenzer-Zimmerer, K

2011-12-01

Mirroring of missing facial parts and rapid prototyping of templates have become widely used in the manufacture of prostheses. However, mirroring is not applicable for central facial defects, and the manufacture of a template still requires labour-intensive transformation into the final facial prosthesis. We have explored innovative techniques to meet these remaining challenges. We used a morphable model of a face for the reconstruction of missing facial parts that did not have mirror images, and skin-coloured polyamide laser sintering for direct manufacture of the prosthesis. From the knowledge gleaned from a data set of 200 coloured, three-dimensional scans, we generated a missing nose that was statistically compatible with the remaining parts of the patient's face. The planned prosthesis was manufactured directly from biocompatible skin-coloured polyamide powder by selective laser sintering, and the prosthesis planning system produced a normal-looking reconstruction. The polyamide will need adjustable colouring, and we must be able to combine it with a self-curing resin to fulfil the requirements of realistic permanent use. Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Cost-effective system for facial imaging and three-dimensional reconstruction

Science.gov (United States)

Shokouhi, S. B.; Monro, D. M.; Sherlock, Barry G.

1998-06-01

Three dimensional (3-D) images have recently received wide attention in applications involving medical treatment. Most current 3-D imaging methods focus on the internal organs of the body. However, several medical image applications such as plastic surgery, body deformities, rehabilitation, dental surgery and orthodontics, make use of the surface contours of the body. Several techniques are currently available for producing 3-D images of the body surface and most of the systems which implement these techniques are expensive, requiring complex equipment with highly trained operators. The research involves the development of a simple, low cost and non-invasive contour capturing method for facial surfaces. This is achieved using the structured light technique, employing a standard commercial slide projector, CCD camera and a frame-grabber card linked to a PC. Structured light has already been used for many applications, but only to a limited extent in the clinical environment. All current implementations involve extensive manual intervention by highly skilled operators and this has proven to be a serious hindrance to clinical acceptance of 3-D imaging. A primary objective of this work is to minimize the amount of manual intervention required, so that the system can be used by clinicians who do not have specialist training in the use of this equipment. The eventual aim is to provide a software assisted surgical procedure, which by merging the facial data, allows the manipulation of soft tissue and gives the facility to predict and monitor post-surgical appearance. The research focuses on how the images are obtained using the structured light optic system and the subsequent image processing of data to give a realistic 3-D image.

Effect of a Facial Muscle Exercise Device on Facial Rejuvenation.

Science.gov (United States)

Hwang, Ui-Jae; Kwon, Oh-Yun; Jung, Sung-Hoon; Ahn, Sun-Hee; Gwak, Gyeong-Tae

2018-01-20

The efficacy of facial muscle exercises (FMEs) for facial rejuvenation is controversial. In the majority of previous studies, nonquantitative assessment tools were used to assess the benefits of FMEs. This study examined the effectiveness of FMEs using a Pao (MTG, Nagoya, Japan) device to quantify facial rejuvenation. Fifty females were asked to perform FMEs using a Pao device for 30 seconds twice a day for 8 weeks. Facial muscle thickness and cross-sectional area were measured sonographically. Facial surface distance, surface area, and volumes were determined using a laser scanning system before and after FME. Facial muscle thickness, cross-sectional area, midfacial surface distances, jawline surface distance, and lower facial surface area and volume were compared bilaterally before and after FME using a paired Student t test. The cross-sectional areas of the zygomaticus major and digastric muscles increased significantly (right: P jawline surface distances (right: P = 0.004, left: P = 0.003) decreased significantly after FME using the Pao device. The lower facial surface areas (right: P = 0.005, left: P = 0.006) and volumes (right: P = 0.001, left: P = 0.002) were also significantly reduced after FME using the Pao device. FME using the Pao device can increase facial muscle thickness and cross-sectional area, thus contributing to facial rejuvenation. © 2018 The American Society for Aesthetic Plastic Surgery, Inc.

Laser assisted drug delivery: a review of an evolving technology.

Science.gov (United States)

Sklar, Lindsay R; Burnett, Christopher T; Waibel, Jill S; Moy, Ronald L; Ozog, David M

2014-04-01

Topically applied drugs have a relatively low cutaneous bioavailability. This article reviews the existing applications of laser assisted drug delivery, a means by which the permeation of topically applied agents can be enhanced into the skin. The existing literature suggests that lasers are a safe and effective means of enhancing the delivery of topically applied agents through the skin. The types of lasers most commonly studied in regards to drug delivery are the carbon dioxide (CO2 ) and erbium:yttrium-aluminum-garnet (Er:YAG) lasers. Both conventional ablative and fractional ablative modalities have been utilized and are summarized herein. The majority of the existing studies on laser assisted drug delivery have been performed on animal models and additional human studies are needed. Laser assisted drug delivery is an evolving technology with potentially broad clinical applications. Multiple studies demonstrate that laser pretreatment of the skin can increase the permeability and depth of penetration of topically applied drug molecules for both local cutaneous and systemic applications. © 2014 Wiley Periodicals, Inc.

Clinical and Histological Evaluations of Enlarged Facial Skin Pores After Low Energy Level Treatments With Fractional Carbon Dioxide Laser in Korean Patients.

Science.gov (United States)

Kwon, Hyuck Hoon; Choi, Sun Chul; Lee, Won-Yong; Jung, Jae Yoon; Park, Gyeong-Hun

2018-03-01

Enlarged facial pores can be an early manifestation of skin aging and they are a common aesthetic concern for Asians. However, studies of improving the appearance of enlarged pores have been limited. The authors aimed to study the application of CO2 fractional laser treatment in patients with enlarged facial pores. A total of 32 patients with dilated facial pores completed 3 consecutive sessions of low energy level treatments with a fractional CO2 laser at 4-week intervals. Image analysis was performed to calculate the number of enlarged pores before each treatment session and 12 weeks after the final treatment. After application of laser treatments, there was a significant decrease in the number of enlarged pores. The mean number of enlarged pores was decreased by 28.8% after the second session and by 54.5% at post-treatment evaluation. Post-treatment side effects were mild and transitory. Histological and immunohistochemical analyses demonstrated clear increases in the number of collagen fibers and the expression of transforming growth factor-β1. The short-term results showed that treatment with low energy level CO2 fractional laser therapy could be a safe and effective option for patients with Fitzpatrick skin Types III and IV who are concerned with enlarged pores.

Redefining face contour with a novel anti-aging cosmetic product: an open-label, prospective clinical study.

Science.gov (United States)

Garre, Aurora; Martinez-Masana, Gemma; Piquero-Casals, Jaime; Granger, Corinne

2017-01-01

Skin aging is accelerated by multiple extrinsic factors: ultraviolet radiation, smoking and pollution increase oxidative activity, damaging cellular and extracellular components such as DNA, proteins, and lipids. With age, collagen and hyaluronic acid levels decline, resulting in loss of elasticity and moisture of the skin. Over time this damage leads to characteristic signs that make the skin look older: altered facial contour, sagging skin, wrinkles, and an uneven complexion. This study evaluated the anti-aging effects of a new facial cream formulated with carnosine, Alteromonas ferment extract, crosspolymer hyaluronic acid, and a tripeptide. An open-label intra-individual study to assess the anti-aging efficacy of the investigational product in 33 women aged 45 to 65 years. The product was applied twice daily for 56 days. Facial contour and skin deformation, elasticity, hydration, and complexion were measured with specialized equipment at baseline and days 28 and 56. Additionally, subjects completed questionnaires at days 28 and 56 on the perceived efficacy and cosmetic characteristics of the product. After 56 days of use of the investigational product, a redefining effect was observed, with a significant decrease in sagging jawline (7%). Skin was significantly more hydrated (12%), firmer (29%), and more elastic (20%) ( P <0.001 for all). On complexion assessment, skin texture (a measure of skin smoothness) and spots (brown and red skin lesions) also improved significantly (12% and 6% decrease, respectively). In the subjective self-evaluation, the majority of subjects reported that the skin was visibly tightened and more elastic, flexible, and moisturized (91%, 88%, 91%, and 90%, respectively). The product was well tolerated with no adverse events reported during the study. This new cosmetic product demonstrated anti-aging effects after 56 days of use, most notably a redefined facial contour and improved complexion. It is a safe and effective anti-aging product.

Q-Switched Nd:YAG Laser Removal of Facial Amateur Tattoos in Patients With Fitzpatrick Type VI: Case Series.

Science.gov (United States)

Haik, Josef; Kornhaber, Rachel; Harats, Moti; Israeli, Hadar; Orenstein, Arie

2016-11-01

Q-switched neodymium:YAG (Nd:YAG) lasers are reported to be gold standard for laser tattoo removal. In particular, the Q-switched Nd:YAG laser at 1064 nm is widely recognized for the removal of blue/black amateur tattoos. However, treatment modalities in Fitzpatrick Type VI skin carry a greater risk of complications including alterations in pigmentation compared to fairer skin (Fitzpatrick Type I-IV skin). Therefore, the aim of this case series was to describe with the use of the Q-Switched Nd:YAG laser, the removal of carbon-based amateur tattoos on patients with Fitzpatrick Type VI skin as an effective and safe method. Twenty- five patients with Fitzpatrick type VI skin, from Ethiopian origins, with facial tribal tattoos, were treated with the Q- Switched Nd:YAG laser at 1064 nm. Digital images were taken upon every treatment and the clearance rates of the tattoo was evalu- ated by imaging software. We observed an average tattoo clearance rate of 95% among the 45 facial tattoos in 25 patients presented in the case series with minimal pigmentary and textual changes evident. These positive aesthetic results have a signi cant psychosocial impact on the lives of those with Fitzpatrick Type VI skin, in particular the Ethiopian Jewish population. J Drugs Dermatol. 2016;15(11):1448-1452..

Single treatment with 100-microsecond alexandrite laser clears selected acquired melanocytic nevi in type IV asian facial skin

Directory of Open Access Journals (Sweden)

Etienne CE Wang

2013-01-01

Full Text Available Context: Small common acquired melanocytic nevi (AMNs are common on Asian facial skin. Aims: To show that the 755 nm Alexandrite laser stacked at the 100-μs long-pulsed mode (μsAL is an effective modality for the removal of selected AMNs. Settings and Design: This was a retrospective case series, followed up with a telephone interview. Materials and Methods: A retrospective analysis of all patients treated between January 2010 and April 2012 with the μsAL laser for small AMNs was conducted. Pre- and post-treatment facial photographs and photographs of the individual lesions were analyzed by two independent dermatological surgeons for degree of clearance and complications. A telephone interview was conducted with the patients to assess their satisfaction with the procedure. Results: A total of 18 patients with 53 lesions were included. 7/18 (38.9% of patients had ′excellent′ results. No patients had ′mild′ or ′poor′ results. At 4 week post-treatment, 49/53 (92.5% were totally cleared, with 14/53 (26.4% reporting mild atrophy, and 11/53 (20.8% reporting mild post-inflammatory hypopigmentation. The majority of lesions had negligible complications. 9/18 (50% judged the procedure to be ′excellent′, and all patients reported that they would recommend this procedure to a friend seeking removal of small facial AMNs. Conclusion: The μsAL is an effective modality for the removal of small facial AMNs.

Treatment of Previously Treated Facial Capillary Malformations: Results of Single-Center Retrospective Objective 3-Dimensional Analysis of the Efficacy of Large Spot 532 nm Lasers.

Science.gov (United States)

Kwiek, Bartłomiej; Ambroziak, Marcin; Osipowicz, Katarzyna; Kowalewski, Cezary; Rożalski, Michał

2018-06-01

Current treatment of facial capillary malformations (CM) has limited efficacy. To assess the efficacy of large spot 532 nm lasers for the treatment of previously treated facial CM with the use of 3-dimensional (3D) image analysis. Forty-three white patients aged 6 to 59 were included in this study. Patients had 3D photography performed before and after treatment with a 532 nm Nd:YAG laser with large spot and contact cooling. Objective analysis of percentage improvement based on 3D digital assessment of combined color and area improvement (global clearance effect [GCE]) were performed. The median maximal improvement achieved during the treatment (GCE) was 59.1%. The mean number of laser procedures required to achieve this improvement was 6.2 (range 1-16). Improvement of minimum 25% (GCE25) was achieved by 88.4% of patients, a minimum of 50% (GCE50) by 61.1%, a minimum of 75% (GCE75) by 25.6%, and a minimum of 90% (GCE90) by 4.6%. Patients previously treated with pulsed dye lasers had a significantly less response than those treated with other modalities (GCE 37.3% vs 61.8%, respectively). A large spot 532 nm laser is effective in previously treated patients with facial CM.

Rapid and efficient proteolysis through laser-assisted immobilized enzyme reactors.

Science.gov (United States)

Zhang, Peng; Gao, Mingxia; Zhu, Shaochun; Lei, Jie; Zhang, Xiangmin

2011-11-25

In this report, laser radiation (808nm) for the first time was employed to enhance the efficiency of proteolysis through immobilized enzyme reactor (IMER). IMER based monolithic support was prepared in the fused-silica capillary via a simple two-step procedure including acryloylation on trypsin surface and in situ aqueous polymerization/immobilization. The feasibility and high efficiency of the laser-assisted IMER were demonstrated by the digestion of bovine serum albumin (BSA), cytochrome c (Cyt-c) and β-casein. The digestion process was achieved in 60s. The peptides were identified by MALDI-TOF-MS, yielding the sequence coverage of 33% for BSA, 73% for Cyt-c and 22% for β-casein. The comparisons between the in-solution digestion and on IMER reaction with/without laser assistance were made. To further confirm its efficiency in proteome analysis, the laser-assisted IMER was also applied to the analysis of one fraction of human serum sample through two-dimensional (2-D) separation of strong anion exchange/reversed-phase liquid chromatography (SAX/RPLC). After a database search, 49 unique peptides corresponding to 5 proteins were identified. The results showed that the laser-assisted IMER provides a promising platform for the high-throughput protein identification. Copyright © 2011 Elsevier B.V. All rights reserved.

Automated Laser Cutting In Three Dimensions

Science.gov (United States)

Bird, Lisa T.; Yvanovich, Mark A.; Angell, Terry R.; Bishop, Patricia J.; Dai, Weimin; Dobbs, Robert D.; He, Mingli; Minardi, Antonio; Shelton, Bret A.

1995-01-01

Computer-controlled machine-tool system uses laser beam assisted by directed flow of air to cut refractory materials into complex three-dimensional shapes. Velocity, position, and angle of cut varied. In original application, materials in question were thermally insulating thick blankets and tiles used on space shuttle. System shapes tile to concave or convex contours and cuts beveled edges on blanket, without cutting through outer layer of quartz fabric part of blanket. For safety, system entirely enclosed to prevent escape of laser energy. No dust generated during cutting operation - all material vaporized; larger solid chips dislodged from workpiece easily removed later.

Laser-assisted shape selective fragmentation of nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Kazakevich, P.V. [Wave Research Center, General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 117942 Moscow (Russian Federation); Simakin, A.V. [Wave Research Center, General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 117942 Moscow (Russian Federation); Shafeev, G.A. [Wave Research Center, General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 117942 Moscow (Russian Federation)]. E-mail: shafeev@kapella.gpi.ru; Viau, G. [ITODYS, UMR 7086, Universite Paris 7-Denis Diderot, case 7090, 2 place Jussieu, 75251 Paris Cedex 05 (France); Soumare, Y. [ITODYS, UMR 7086, Universite Paris 7-Denis Diderot, case 7090, 2 place Jussieu, 75251 Paris Cedex 05 (France); Bozon-Verduraz, F. [ITODYS, UMR 7086, Universite Paris 7-Denis Diderot, case 7090, 2 place Jussieu, 75251 Paris Cedex 05 (France)

2007-07-31

Experimental results are presented on laser-assisted fragmentation of gold-containing nanoparticles suspended in liquids (either ethanol or water). Two kinds of nanoparticles are considered: (i) elongated Au nanorods synthesized by laser ablation of a gold target immersed in liquid phase; (ii) gold-covered NiCo nanorods with high aspect ratio ({theta} {approx} 10) synthesized by wet chemistry processes. The shape selectivity induced by laser fragmentation of these nanorods is gained via tuning the wavelength of laser radiation into different parts of the spectrum of their plasmon resonance corresponding to different aspect ratios {theta}. Fragmentation is performed using three laser wavelengths, involving a Cu vapour laser (510 and 578 nm) and a Nd:YAG (1064 nm). Nanoparticles are characterized by UV-vis spectrometry, Transmission Electron Microscopy (TEM). The effect of laser pulse duration (nanosecond against picosecond range) is also studied in the case of fragmentation with an IR laser radiation.

Laser Assisted Free-Free Transition in Electron - Atom Collision

Science.gov (United States)

Sinha, C.; Bhatia, A. K.

2011-01-01

Free-free transition is studied for electron-Hydrogen atom system in ground state at very low incident energies in presence of an external homogeneous, monochromatic and linearly polarized laser field. The incident electron is considered to be dressed by the laser in a non perturbative manner by choosing the Volkov solutions in both the channels. The space part of the scattering wave function for the electron is solved numerically by taking into account the effect of electron exchange, short range as well as of the long range interactions. Laser assisted differential as well as elastic total cross sections are calculated for single photon absorption/emission in the soft photon limit, the laser intensity being much less than the atomic field intensity. A strong suppression is noted in the laser assisted cross sections as compared to the field free situations. Significant difference is noted in the singlet and the triplet cross sections.

Laser-assisted delivery of topical methotrexate - in vitro investigations

DEFF Research Database (Denmark)

Taudorf, Elisabeth Hjardem

2016-01-01

of the correlation between laser parameters and tissue effects was used to deliver methotrexate (MTX) topically through microscopic ablation zones (MAZs) of precise dimensions. MTX is a well-known chemotherapeutic and anti-inflammatory drug that may cause systemic adverse effects, and topical delivery is thus......Ablative fractional lasers (AFXL) are increasingly used to treat dermatological disorders and to facilitate laser-assisted topical drug delivery. In this thesis, laser-tissue interactions generated by stacked pulses with a miniaturized low-power 2,940 nm AFXL were characterized (study I). Knowledge...... zones of varying thickness. The ratio of skin deposition versus transdermal permeation was constant, regardless of MAZ depth. Impact of transport kinetics on AFXL-assisted topical MTX delivery: MTX accumulated rapidly in AFXL-processed skin. MTX was detectable in mid-dermis after 15 min. and saturated...

980 nm diode lasers in oral and facial practice: current state of the science and art.

Science.gov (United States)

Desiate, Apollonia; Cantore, Stefania; Tullo, Domenica; Profeta, Giovanni; Grassi, Felice Roberto; Ballini, Andrea

2009-11-24

To evaluate the safety and efficacy of a 980 nm diode laser for the treatment of benign facial pigmented and vascular lesions, and in oral surgery. 20 patients were treated with a 980 nm diode laser. Oral surgery: 5 patients (5 upper and lower frenulectomy). Fluence levels were 5-15 J/cm(2); pulse lengths were 20-60 ms; spot size was 1 mm. Vascular lesions: 10 patients (5 small angiomas, 5 telangiectases). Fluences were 6-10 J/cm(2); pulse lengths were 10-50 ms; spot size was 2 mm. In all cases the areas surrounding the lesions were cooled. Pigmented lesions: 5 patients (5 keratoses). All the lesions were evaluated by dermatoscopy before the treatment. Fluence levels were 7-15 J/cm(2); pulse lengths were 20-50 ms; spot size was 1 mm. All the patients were followed at 1, 4 and 8 weeks after the procedure. Healing in oral surgery was within 10 days. The melanoses healed completely within four weeks. All the vascular lesions healed after 15 days without any residual scarring. The end results for the use of the 980 nm diode laser in oral and facial surgery appears to be justified on the grounds of efficacy and safety of the device, and good degree of acceptance by the patients, without compromising their health and function.

Laser assisted robotic surgery in cornea transplantation

Science.gov (United States)

Rossi, Francesca; Micheletti, Filippo; Magni, Giada; Pini, Roberto; Menabuoni, Luca; Leoni, Fabio; Magnani, Bernardo

2017-03-01

Robotic surgery is a reality in several surgical fields, such as in gastrointestinal surgery. In ophthalmic surgery the required high spatial precision is limiting the application of robotic system, and even if several attempts have been designed in the last 10 years, only some application in retinal surgery were tested in animal models. The combination of photonics and robotics can really open new frontiers in minimally invasive surgery, improving the precision, reducing tremor, amplifying scale of motion, and automating the procedure. In this manuscript we present the preliminary results in developing a vision guided robotic platform for laser-assisted anterior eye surgery. The robotic console is composed by a robotic arm equipped with an "end effector" designed to deliver laser light to the anterior corneal surface. The main intended application is for laser welding of corneal tissue in laser assisted penetrating keratoplasty and endothelial keratoplasty. The console is equipped with an integrated vision system. The experiment originates from a clear medical demand in order to improve the efficacy of different surgical procedures: when the prototype will be optimized, other surgical areas will be included in its application, such as neurosurgery, urology and spinal surgery.

Dependence of laser assisted cleaning of clad surfaces on the laser fluence

International Nuclear Information System (INIS)

Nilaya, J.P.; Raote, P.; Sai Prasad, M.B.; Biswas, D.J.; Aniruddha Kumar

2005-01-01

The decontamination factor is studied as a function of laser fluence for three kinds of clad surfaces viz., plain zircaloy, autoclaved zircaloy and SS with cesium as the test contamination. It has been found that the decontamination factor exhibits a maximal behaviour with the laser fluence and its maximum value occurs at different laser fluences in the three cases. The maximal behaviour is attributed to reduced coupling of energy from the laser beam to the substrate due to the initiation of surface-assisted optical breakdown. The results obtained in the experiment carried out in helium environment qualitatively support this explanation (author)

CO2-laser-assisted processing of glass fiber-reinforced thermoplastic composites

Science.gov (United States)

Brecher, Christian; Emonts, Michael; Schares, Richard Ludwig; Stimpfl, Joffrey

2013-02-01

To fully exploit the potential of fiber-reinforced thermoplastic composites (FRTC) and to achieve a broad industrial application, automated manufacturing systems are crucial. Investigations at Fraunhofer IPT have proven that the use of laser system technology in processing FRTC allows to achieve high throughput, quality, flexibility, reproducibility and out-of-autoclave processing simultaneously. As 90% of the FRP in Europe1 are glass fiber-reinforced a high impact can be achieved by introducing laser-assisted processing with all its benefits to glass fiber-reinforced thermoplastics (GFRTC). Fraunhofer IPT has developed the diode laser-assisted tape placement (laying and winding) to process carbon fiber-reinforced thermoplastic composites (CFRTC) for years. However, this technology cannot be transferred unchanged to process milky transparent GFRTC prepregs (preimpregnated fibers). Due to the short wavelength (approx. 980 nm) and therefore high transmission less than 20% of the diode laser energy is absorbed as heat into non-colored GFRTC prepregs. Hence, the use of a different wave length, e.g. CO2-laser (10.6 μm) with more than 90% laser absorption, is required to allow the full potential of laser-assisted processing of GFRTC. Also the absorption of CO2-laser radiation at the surface compared to volume absorption of diode laser radiation is beneficial for the interlaminar joining of GFRTC. Fraunhofer IPT is currently developing and investigating the CO2-laser-assisted tape placement including new system, beam guiding, process and monitoring technology to enable a resource and energy efficient mass production of GFRP composites, e.g. pipes, tanks, masts. The successful processing of non-colored glass fiber-reinforced Polypropylene (PP) and Polyphenylene Sulfide (PPS) has already been proven.

Laser-assisted printing of alginate long tubes and annular constructs

International Nuclear Information System (INIS)

Yan Jingyuan; Huang Yong; Chrisey, Douglas B

2013-01-01

Laser-assisted printing such as laser-induced forward transfer has been well studied to pattern or fabricate two-dimensional constructs. In particular, laser printing has found increasing biomedical applications as an orifice-free cell and organ printing approach, especially for highly viscous biomaterials and biological materials. Unfortunately, there have been very few studies on the efficacy of three-dimensional printing performance of laser printing. This study has investigated the feasibility of laser tube printing and the effects of sodium alginate concentration and operating conditions such as the laser fluence and laser spot size on the printing quality during laser-assisted printing of alginate annular constructs (short tubes) with a nominal diameter of 3 mm. It is found that highly viscous materials such as alginate can be printed into well-defined long tubes and annular constructs. The tube wall thickness and tube outer diameter decrease with the sodium alginate concentration, while they first increase, then decrease and finally increase again with the laser fluence. The sodium alginate concentration dominates if the laser fluence is low, and the laser fluence dominates if the sodium alginate concentration is low. (paper)

Combustion-assisted laser cutting of a difficult-to-machine superalloy

International Nuclear Information System (INIS)

Molian, P.A.

1992-01-01

In laser cutting, the largest single application of lasers in manufacturing, the assist gas plays an important role in affecting the cutting performance. The assist gas is usually oxygen or an inert gas. In this paper acetylene and oxygen was employed to create combustion reactions during CO 2 laser cutting that enabled an improvement in the cutting speed, and cut quality of a difficult-to-machine superalloy. A comparison with laser cutting of a plain carbon steel under identical conditions was also made to determine the usefulness of combustion energy. Results indicate that both cutting speed and quality are enhanced by the reduction in the viscosity of slag formed during cutting (which assisted in ejection of the slag through the bottom of the kerf) due to the heat released by the acetylene burning inside the kerf. Correlations of experimental data with a theoretical model provided the influence of combustion power and gas-flow power on the cutting phenomena

Straylight before and after hyperopic laser in situ keratomileusis or laser-assisted subepithelial keratectomy

NARCIS (Netherlands)

Lapid-Gortzak, Ruth; van der Linden, Jan Willem; van der Meulen, Ivanka J. E.; Nieuwendaal, Carla P.; Mourits, Maarten P.; van den Berg, Thomas J. T. P.

2010-01-01

PURPOSE To compare straylight values before and 3 months after hyperopic laser in situ keratomileusis (LASIK) or laser-assisted subepithelial keratectomy (LASEK) and determine the cause of any change SETTING Private refractive surgery clinic, Driebergen, The Netherlands DESIGN Comparative case

Straylight measurements in laser in situ keratomileusis and laser-assisted subepithelial keratectomy for myopia

NARCIS (Netherlands)

Lapid-Gortzak, Ruth; van der Linden, Jan Willem; van der Meulen, Ivanka; Nieuwendaal, Carla; van den Berg, Tom

2010-01-01

PURPOSE: To compare straylight values before and 3 months after laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK) and to analyze the causes of any change. SETTING: Private refractive surgery clinic, Driebergen, The Netherlands. METHODS: Straylight was measured

Centralization or decentralization of facial structures in Korean young adults.

Science.gov (United States)

Yoo, Ja-Young; Kim, Jeong-Nam; Shin, Kang-Jae; Kim, Soon-Heum; Choi, Hyun-Gon; Jeon, Hyun-Soo; Koh, Ki-Seok; Song, Wu-Chul

2013-05-01

It is well known that facial beauty is dictated by facial type, and harmony between the eyes, nose, and mouth. Furthermore, facial impression is judged according to the overall facial contour and the relationship between the facial structures. The aims of the present study were to determine the optimal criteria for the assessment of gathering or separation of the facial structures and to define standardized ratios for centralization or decentralization of the facial structures.Four different lengths were measured, and 2 indexes were calculated from standardized photographs of 551 volunteers. Centralization and decentralization were assessed using the width index (interpupillary distance / facial width) and height index (eyes-mouth distance / facial height). The mean ranges of the width index and height index were 42.0 to 45.0 and 36.0 to 39.0, respectively. The width index did not differ with sex, but males had more decentralized faces, and females had more centralized faces, vertically. The incidence rate of decentralized faces among the men was 30.3%, and that of centralized faces among the women was 25.2%.The mean ranges in width and height indexes have been determined in a Korean population. Faces with width and height index scores under and over the median ranges are determined to be "centralized" and "decentralized," respectively.

Split-face comparison of long-pulse-duration neodymium-doped yttrium aluminum garnet (Nd:YAG) 1,064-nm laser alone and combination long-pulse and Q-switched Nd:YAG 1,064-nm laser with carbon photoenhancer lotion for the treatment of enlarged pores in Asian women.

Science.gov (United States)

Wattanakrai, Penpun; Rojhirunsakool, Salinee; Pootongkam, Suwimon

2010-11-01

Long-pulse and Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) 1,064-nm laser used for facial rejuvenation can improve pore size. Topical carbon has been used to enhance efficacy. To compare the efficacy and safety of a 1,064-nm long-pulse Nd:YAG laser alone with that of a combination Q-switched Nd:YAG laser with topical carbon lotion followed by long-pulse Nd:YAG to improve enlarged pores. Twenty Thai women randomly received five treatments with a long-pulse Nd:YAG laser on one facial half (LP side) and long-pulse Nd:YAG after carbon-assisted Q-switched Nd:YAG laser on the contralateral side (carbon QS+LP side) at 2-week intervals. Participants were evaluated using digital photography, complexion analysis, and a chromometer. There was significant decrease in pore counts of 35.5% and 33% from baseline on the carbon QS+LP and LP sides, respectively. Physician-evaluated pore size improvement was 67% on the carbon QS+LP sides and 60% on the LP sides. Chromometer measurement showed an increase in skin lightness index. There was no significant difference between the two treatments, although there were more adverse effects on the carbon QS+LP side. Long-pulse Nd:YAG 1,064-nm laser improves the appearance of facial pores and skin color. Adding carbon-assisted Q-switched Nd:YAG did not enhance the results but produced more side effects. © 2010 by the American Society for Dermatologic Surgery, Inc.

A Fast and On-Machine Measuring System Using the Laser Displacement Sensor for the Contour Parameters of the Drill Pipe Thread

Directory of Open Access Journals (Sweden)

Zhixu Dong

2018-04-01

Full Text Available The inconvenient loading and unloading of a long and heavy drill pipe gives rise to the difficulty in measuring the contour parameters of its threads at both ends. To solve this problem, in this paper we take the SCK230 drill pipe thread-repairing machine tool as a carrier to design and achieve a fast and on-machine measuring system based on a laser probe. This system drives a laser displacement sensor to acquire the contour data of a certain axial section of the thread by using the servo function of a CNC machine tool. To correct the sensor’s measurement errors caused by the measuring point inclination angle, an inclination error model is built to compensate data in real time. To better suppress random error interference and ensure real contour information, a new wavelet threshold function is proposed to process data through the wavelet threshold denoising. Discrete data after denoising is segmented according to the geometrical characteristics of the drill pipe thread, and the regression model of the contour data in each section is fitted by using the method of weighted total least squares (WTLS. Then, the thread parameters are calculated in real time to judge the processing quality. Inclination error experiments show that the proposed compensation model is accurate and effective, and it can improve the data acquisition accuracy of a sensor. Simulation results indicate that the improved threshold function is of better continuity and self-adaptability, which makes sure that denoising effects are guaranteed, and, meanwhile, the complete elimination of real data distorted in random errors is avoided. Additionally, NC50 thread-testing experiments show that the proposed on-machine measuring system can complete the measurement of a 25 mm thread in 7.8 s, with a measurement accuracy of ±8 μm and repeatability limit ≤ 4 μm (high repeatability, and hence the accuracy and efficiency of measurement are both improved.

Efficacy of pulsed dye laser in cosmetically distressing facial dermatoses in skin types IV and V

Directory of Open Access Journals (Sweden)

Khandpur Sujay

2008-01-01

Full Text Available Background: Pulsed dye laser (PDL has revolutionized treatment of vascular dermatoses. It has been successfully employed to treat several non-vascular conditions in fair skinned individuals without producing significant pigmentary and textural complications. Aim: A preliminary study was undertaken to assess its efficacy in cosmetically distressing facial, vascular and non-vascular dermatoses in Indian patients with skin types IV and V. Materials and Methods: Nine patients of ages 7 to 55 years, with facial verruca plana (VP- 4 cases, angiofibromas (AF- 4 cases and multiple pyogenic granulomas (PG- one case were recruited. They had no systemic complaints. Laser parameters used were (spot size/fluence/wavelength/pulse duration:VP- 5mm/5.5-7.5J/585nm/0.45ms; AF-5mm/6-8.5J/585nm/0.45ms;PG- 5mm/7J/585 and 595nm alternately/1.5ms. Response was assessed clinically and photographically. Results and Conclusions: All VP lesions completely resolved after 2-4 sessions (mean 3.25 sessions, AF showed 50% regression in all cases after 2-3 sessions (mean 2.5 sessions and ≥75% subsidence after 3-7 sessions (mean 5.5 sessions and in PG, after 3 sessions, there was complete subsidence of small satellite lesions with moderate shrinkage of larger papules and complete resolution after 5 sessions. Complications included transient hyperpigmentation/hypopigmentation only. There was no recurrence during next 6 months. PDL offers significant cosmetic improvement in facial dermatoses in Indian patients.

Experience with esthetic reconstruction of complex facial soft tissue trauma: application of the pulsed dye laser.

Science.gov (United States)

Ebrahimi, Ali; Kazemi, Hossein Mohammad; Nejadsarvari, Nasrin

2014-08-01

Facial soft tissue injury can be one of the most challenging cases presenting to the plastic surgeon. The life quality and self-esteem of the patients with facial injury may be compromised temporarily or permanently. Immediate reconstruction of most defects leads to better restoration of form and function as well as early rehabilitation. The aim of this study was to present our experience in management of facial soft tissue injuries from different causes. We prospectively studied patients treated by plastic surgeons from 2010 to 2012 suffering from different types of blunt or sharp (penetrating) facial soft tissue injuries to the different areas of the face. All soft tissue injuries were treated primarily. Photography from all patients before, during, and after surgical reconstruction was performed and the results were collected. We used early pulsed dye laser (PDL) post-operatively. In our study, 63 patients including 18 (28.5%) women and 45 (71.5%) men aged 8-70 years (mean 47 years) underwent facial reconstruction due to soft tissue trauma in different parts of the face. Sharp wounds were seen in 15 (23%) patients and blunt trauma lacerations were seen in 52 (77%) patients. Overall, 65% of facial injuries were repaired primary and the remainder were reconstructed with local flaps or skin graft from adjacent tissues. Postoperative PDL therapy done two weeks following surgery for all scars yielded good results in our cases. Analysis of the injury including location, size, and depth of penetration as well as presence of associated injuries can aid in the formulation of a proper surgical plan. We recommend PDL in the early post operation period (two weeks) after suture removal for better aesthetic results.

Translational medicine in the field of ablative fractional laser (AFXL)-assisted drug delivery

DEFF Research Database (Denmark)

Haedersdal, Merete; Erlendsson, Andrés M; Paasch, Uwe

2016-01-01

Ablative fractional lasers enhance uptake of topical therapeutics and the concept of fractional laser-assisted drug delivery has now been taken into clinical practice. Objectives We systematically reviewed preclinical data and clinical evidence for fractional lasers to enhance drug uptake...... level of evidence was reached for actinic keratoses treated with methylaminolevulinate for photodynamic therapy (level IB, 5 randomized controlled trials), substantiating superior and long-lasting efficacy versus conventional photodynamic therapy. No adverse events were reported, but ablative fractional...... laser-assisted drug delivery implies risks of systemic drug absorption, especially when performed over large skin areas. Conclusions Fractional laser-assisted drug delivery is beneficial in enhancing preclinical and clinical outcomes for certain skin conditions....

Laser-assisted vacuum arc extreme ultraviolet source: a comparison of picosecond and nanosecond laser triggering

Science.gov (United States)

Beyene, Girum A.; Tobin, Isaac; Juschkin, Larissa; Hayden, Patrick; O'Sullivan, Gerry; Sokell, Emma; Zakharov, Vassily S.; Zakharov, Sergey V.; O'Reilly, Fergal

2016-06-01

Extreme ultraviolet (EUV) light generation by hybrid laser-assisted vacuum arc discharge plasmas, utilizing Sn-coated rotating-disc-electrodes, was investigated. The discharge was initiated by localized ablation of the liquid tin coating of the cathode disc by a laser pulse. The laser pulse, at 1064 nm, was generated by Nd:YAG lasers with variable energy from 1 to 100 mJ per pulse. The impact of shortening the laser pulse from 7 ns to 170 ps on the EUV generation has been investigated in detail. The use of ps pulses resulted in an increase in emission of EUV radiation. With a fixed discharge energy of ~4 J, the EUV conversion efficiency tends to plateau at ~2.4  ±  0.25% for the ps laser pulses, while for the ns pulses, it saturates at ~1.7  ±  0.3%. Under similar discharge and laser energy conditions, operating the EUV source with the ps-triggering resulted also in narrower spectral profiles of the emission in comparison to ns-triggering. The results indicate an advantage in using ps-triggering in laser-assisted discharges to produce brighter plasmas required for applications such as metrology.

Laser-assisted vascular anastomosis

Science.gov (United States)

Kao, Race L.; Tsao-Wu, George; Magovern, George J.

1990-06-01

The milliwatt CO2 laser and a thermal activated binding compound (20% serum albumin) were used for microvascular anastomoses. Under general anesthesia, the femoral arteries (0.7 to 1.0 mm diameter) of 6 rats were isolated. After the left femoral artery in each rat was clamped and transected, the vessel was held together with 3 equidistant 10-0 Xomed sutures. The cut edges were coated 3 to 4 times with the albumin solution and sealed with the CO2 laser (power density = 120 W/cm2). The binding compound solidified to a translucent tensile substance which supported the anastomosis until self healing and repair were achieved. The right femoral artery was used as sham operated control. Complete hemostasis and patency were observed in every case immediately and at 1, 3, and 6 months following surgery. The binding compound absorbed most of the laser energy thus minimizing thermal injury to the underlying tissue. Mongrel dogs weighing 28 to 33 kg were anesthetized and prepared for sterile surgical procedures. In 5 dogs, the femoral and jugular veins were exposed, transected, and anastomosed using a CO2 laser (Sharplan 1040) with the binding compound. In another 12 dogs, cephalic veins were isolated and used for aortocoronary artery bypass procedures. The Sharplan 1040 CO2 laser and 20% albumin solution were utilized to complete the coronary anastomoses in 6 dogs, and 6 dogs were used as controls by suturing the vessels. Again, hemostasis, patency, and minimal tissue damage were observed immediately and 6 weeks after the procedures. Improved surgical results, reduced operating time, minimized tissue damage, and enhanced anastomotic integrity are the advantages of laser assisted vascular anastomosis with a thermal activated binding compound.

Laser assisted removal of fixed contamination from metallic substrate

International Nuclear Information System (INIS)

Kumar, Aniruddha; Prasad, Manisha; Prakash, Tej; Shail, Shailini; Bhatt, R.B.; Behere, P.G.; Mohd Afzal; Kumar, Arun; Biswas, D.J.

2015-01-01

A single mode pulsed fiber laser was used to remove fixed contamination from stainless steel substrate by ablation. Samples were simulated by electro-deposition technique with 232 U as the test contaminant. Laser power, repetition rate, laser beam scanning speed and number of passes were optimised to obtain the desired ablation depth in the substrate. Ablation depth varying between few microns to few hundreds of microns could be achieved through careful control of these processing parameters. The absence of any activity in laser treated samples provided experimental signature of the efficacy of the laser assisted removal of fixed contamination. (author)

Use of a biopolymer polyalkylimide filler for facial lipodystrophy in HIV-positive patients undergoing treatment with antiretroviral drugs.

Science.gov (United States)

Treacy, Patrick J; Goldberg, David J

2006-06-01

To evaluate the efficacy, overall esthetic effect, and safety of a new permanent, polyalkylimide dermal filler in HIV-infected patients with severe facial lipodystrophy. Eleven subjects with severe facial lipodystrophy secondary to HIV infection were injected bilaterally with 15 and 30 cm3 of a polyalkylimide gel into the buccal, malar, and temporal areas of the face in an attempt to restore their facial contour. The youngest treated subject was 31 years of age and the oldest 73 years of age. All 11 subjects received an immediately acceptable therapeutic esthetic effect. Injections were generally well tolerated, with only three adverse events (swelling and bruising) recorded. Subjects, assessed at 3 and 18 months after treatment, continued to show improvement. The immediate benefits of a polyalkylimide gel in the correction and restoration of facial contour in subjects having severe HIV-related facial lipodystrophy were demonstrated. This improvement was still noted at 18 months. The efficacy, ease of injection, and safety profile of polyalkylimide gel make this filling material a potentially attractive treatment for lipodystrophy. These data must be tempered with the need for significant further safety studies to determine whether this long-term filler has a safety profile consistent with other currently popular fillers.

Application of laser assisted cold spraying process for metal deposition

CSIR Research Space (South Africa)

Tlotleng, Monnamme

2014-02-01

Full Text Available Laser assisted cold spraying (LACS) process is a hybrid technique that uses laser and cold spray to deposit solid powders on metal substrates. For bonding to occur, the particle velocities must be supersonic which are achieved by entraining...

Surgical Tip for Prevention of Lip Injury During Orthognathic and Facial Bone Contouring Surgery.

Science.gov (United States)

Lee, Tae Sung; Park, Sanghoon

2017-10-01

Iatrogenic lip injury is a rather common complication after facial bone surgery, but is usually treated lightly by the surgeon compared with other more severe functional complications. However, these injuries can have permanent sequelae and can therefore be a reason for patient dissatisfaction, especially after cosmetic surgery. Intraoperative lip injuries during facial bone surgery are usually caused by heat-generating surgical instruments or forced traction on the operative fields. The authors have applied a special technical strategy using a hydrocolloid dressing material to avoid these intraoperative lip injuries. This method does not disturb the operative procedure itself, but efficiently prevents lip injuries and decreases surgical morbidities and postoperative swelling.

Matrix-assisted laser desorption fourier transform mass spectrometry for biological compounds

Energy Technology Data Exchange (ETDEWEB)

Hettich, R.; Buchanan, M.

1990-01-01

The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons). This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurement, and ion trapping experiments suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have recently demonstrated that matrix-assisted ultraviolet laser desorption can be successfully used with FTMS for the ionization of small peptides. The objective of this report is to summarize the application and current limitations of matrix-assisted laser desorption FTMS for the characterization of peptides and oligonucleotides at the isomeric level. 4 refs., 3 figs., 2 tabs.

Recent advances in femtosecond laser-assisted cataract surgery

Directory of Open Access Journals (Sweden)

Zhao-Jie Chu

2013-07-01

Full Text Available Perfect vision and fewer complications is our goal in cataract surgery, femtosecond laser-assisted cataract surgery hold the promise. Applications of femtosecond laser technology for capsulotomy, nuclear fragmentation and corneal incision in cataract surgery bring a new level of accuracy, reproducibility and predictability over the current cataract surgery. The femtosecond laser produces capsulotomies that are more precise, accurate, reproducible, and stronger than those created with the conventional manual technique, and further helps maintain proper positioning of the IOL. Femtosecond laser in nuclear fragmentation lead to a lower effective phacoemulsification time, and the corneal incision is more stable. But currently there are some complications and a clear learning curve associated with the use of femtosecond lasers for cataract surgery. The long-term safety and visual outcomes still need further investigation.

Effects of a 1,450 nm diode laser on facial sebum excretion.

Science.gov (United States)

Laubach, Hans-Joachim; Astner, Susanne; Watanabe, Kanna; Clifford, Joan; Rius-Diaz, Francisca; Zurakowski, David; Manstein, Dieter

2009-02-01

Laser therapy with a 1,450 nm diode laser is a clinically effective treatment for acne vulgaris, although the mechanism of action is unknown. To investigate this, we conducted a small, prospective, controlled clinical trial to assess this laser's effects on the facial sebum excretion rate (SER). Fourteen healthy volunteers without active acne were enrolled in this study and received three laser treatments on test areas of the nose and forehead. Nine subjects completed the treatment regimen and were available for follow-up. SER was measured with Sebumeter prior to the first treatment, and at 1 week and 1 month after the third treatment. Photographs were taken and subjective assessment of skin oiliness and pore size determined by questionnaires at 1 month follow-up. No significant reduction in SER was observed comparing treated with control on all treatment sites (P>0.05) on the nose. Reduction in the absolute SER was observed for both test and control sites on the forehead, reaching significance on the treatment site (P = 0.04) and marginal significance on the control site (P = 0.08). While our study was designed to detect only large changes in SER, we conclude that three 1,450 nm laser treatment sessions did not cause marked changes in SER compared to the control (i.e., >44%). Thus, major destruction of sebaceous glands as a result of this treatment is unlikely. However, reduced sebum production was observed on both treatment and control sides at 1 month. Therefore alternative mechanisms should also be considered to explain the clinical efficacy of this treatment for acne vulgaris. (c) 2009 Wiley-Liss, Inc.

Fractional CO(2) laser-assisted drug delivery

DEFF Research Database (Denmark)

Haedersdal, Merete; Sakamoto, Fernanda H; Farinelli, William A

2010-01-01

Ablative fractional resurfacing (AFR) creates vertical channels that might assist the delivery of topically applied drugs into skin. The purpose of this study was to evaluate drug delivery by CO(2) laser AFR using methyl 5-aminolevulinate (MAL), a porphyrin precursor, as a test drug....

Antimony sulfide thin films prepared by laser assisted chemical bath deposition

International Nuclear Information System (INIS)

Shaji, S.; Garcia, L.V.; Loredo, S.L.; Krishnan, B.

2017-01-01

Highlights: • Antimony sulfide thin films were prepared by normal CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • These films were photoconductive. - Abstract: Antimony sulfide (Sb_2S_3) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb_2S_3 thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb_2S_3 thin films for optoelectronic applications.

Antimony sulfide thin films prepared by laser assisted chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); CIIDIT—Universidad Autónoma de Nuevo León, Apodaca, Nuevo León (Mexico); Garcia, L.V. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); Loredo, S.L. [Centro de Investigación en Materiales Avanzados (CIMAV), Unidad Monterrey, PIIT, Apodaca, Nuevo León (Mexico); Krishnan, B. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); CIIDIT—Universidad Autónoma de Nuevo León, Apodaca, Nuevo León (Mexico); and others

2017-01-30

Highlights: • Antimony sulfide thin films were prepared by normal CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • These films were photoconductive. - Abstract: Antimony sulfide (Sb{sub 2}S{sub 3}) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb{sub 2}S{sub 3} thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb{sub 2}S{sub 3} thin films for optoelectronic applications.

Effect of laser-assisted bleaching with Nd:YAG and diode lasers on shear bond strength of orthodontic brackets.

Science.gov (United States)

Mirhashemi, Amirhossein; Emadian Razavi, Elham Sadat; Behboodi, Sara; Chiniforush, Nasim

2015-12-01

The aim of the present study was to assess the effect of laser-assisted bleaching with neodymium:yttrium-aluminum-garnet (Nd:YAG) and diode lasers on shear bond strength (SBS) of orthodontic brackets. One hundred and four extracted human premolars were randomly divided into four groups: group 1: No bleaching applied (control group); group 2: Teeth bleached with 40 % hydrogen peroxide; group 3: Teeth treated with 30 % hydrogen peroxide activated with Nd:YAG laser (1064 nm, 2.5 W, 25 Hz, pulse duration of 100 μs, 6 mm distance); and group 4: Teeth treated with 30 % hydrogen peroxide activated with diode laser (810 nm, 1 W, CW, 6 mm distance). Equal numbers of teeth in groups 2, 3, and 4 were bonded at start, 1 h, 24 h, and 1 week after bleaching. A universal testing machine measured the SBS of the samples 24 h after bonding. After bracket debonding, the amount of residual adhesive on the enamel surface was observed under a stereomicroscope to determine the adhesive remnant index (ARI) scores. The SBS in the unbleached group was significantly higher than that in the bleached groups bonded immediately and 1 h after laser-assisted bleaching (P laser-assisted bleaching, the SBS was found to be significantly lower than that in the control group. Significant differences in the ARI scores existed among groups as well. The SBS of brackets seems to increase quickly within an hour after laser-assisted bleaching and 24 h after conventional bleaching. Thus, this protocol can be recommended if it is necessary to bond the brackets on the same day of bleaching.

Enlarged facial pores: an update on treatments.

Science.gov (United States)

Dong, Joanna; Lanoue, Julien; Goldenberg, Gary

2016-07-01

Enlarged facial pores remain a common dermatologic and cosmetic concern from acne and rosacea, among other conditions, that is difficult to treat due to the multifactorial nature of their pathogenesis and negative impact on patients' quality of life. Enlarged facial pores are primarily treated through addressing associative factors, such as increased sebum production and cutaneous aging. We review the current treatment modalities for enlarged or dense facial pores, including topical retinoids, chemical peels, oral antiandrogens, and lasers and devices, with a focus on newer therapies.

Facial microcirculatory and biomechanical skin properties after single high energy (Er):YAG laser application.

Science.gov (United States)

Medved, Fabian; Wurm, Antonia; Held, Manuel

2017-12-01

Owing to skin aging and the growing demand for skin rejuvenation, minimal invasive aesthetic treatments such as laser procedures are increasingly coming into focus. However, until now, little has been known about the objective effects of these procedures with respect to skin microcirculation or changes in skin elasticity. Facial skin rejuvenation was performed on 32 volunteers using ablative Erbium: YAG laser. Skin microcirculation and skin elasticity have then been evaluated objectively. Microcirculation (flow, SO 2 , velocity, and rHB) has been analyzed before and directly after the laser session by using the O2C device. Skin elasticity has been evaluated by using the Cutometer device (Uf, Ua, Ur, and Ue) before and directly after the laser treatment, as well as 1 week and then 1, 3, and 6 months post treatment. Further, the outcome for the volunteers regarding their satisfactory level after laser treatment was evaluated. Twenty volunteers were available for a complete follow-up. Microcirculation displayed statistically significant increase in all values to 2 mm depth. The biomechanical skin parameter of firmness of skin displayed statistically significant improvement in superficial skin layer after 6 months. Concerning microcirculation and skin elasticity the ablative Erbium: YAG laser treatment revealed similar effects on the skin like a superficial burn injury. In contrast to the determined skin elasticity parameters, firmness of skin objectively revealed a skin tightening effect after 6 months. Along with the important epidermal effect, the suitability of ablative laser treatment for skin rejuvenation has been proved in a long-term follow-up. Lasers Surg. Med. 49:891-898, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Comparative study on Pulsed Laser Deposition and Matrix Assisted Pulsed Laser Evaporation of urease thin films

International Nuclear Information System (INIS)

Smausz, Tomi; Megyeri, Gabor; Kekesi, Renata; Vass, Csaba; Gyoergy, Eniko; Sima, Felix; Mihailescu, Ion N.; Hopp, Bela

2009-01-01

Urease thin films were produced by Matrix Assisted Pulsed Laser Evaporation (MAPLE) and Pulsed Laser Deposition from two types of targets: frozen water solutions of urease with different concentrations (1-10% m/v) and pure urease pellets. The fluence of the ablating KrF excimer laser was varied between 300 and 2200 mJ/cm 2 . Fourier transform infrared spectra of the deposited films showed no difference as compared to the original urease. Morphologic studies proved that the films consist of a smooth 'base' layer with embedded micrometer-sized droplets. Absorption-coefficient measurements contradicted the traditional 'absorptive matrix' model for MAPLE deposition. The laser energy was absorbed by urease clusters leading to a local heating-up and evaporation of the frozen matrix from the uppermost layer accompanied by the release of dissolved urease molecules. Significant enzymatic activity of urease was preserved only during matrix assisted transfer.

Convergence of anatomy, technology, and therapeutics: a review of laser-assisted drug delivers.

Science.gov (United States)

Brauer, Jeremy A; Krakowski, Andrew C; Bloom, Bradley S; Nguyen, Tuyet A; Geronemus, Roy G

2014-12-01

This is a very exciting time in cutaneous laser surgery with an ever-expanding therapeutic armamentarium and an increased sophistication of available technology. These recent trends have allowed for both a rapid development of interest and exploration of laser-assisted drug delivery and its potential applications. We review the current literature on anatomy, technology, and therapeutics as it relates to laser-assisted drug delivery. The focus of our review is on two areas of interest that have received much attention to date - photodynamic therapy in the treatment of actinic keratoses and nonmelanoma skin cancers as well as the treatment of scarring. We will also discuss potential complications of existing modalities used independently and in laser-assisted drug delivery and conclude with future indications for this burgeoning therapeutic methodology.

Facial sculpting and tissue augmentation.

Science.gov (United States)

Carruthers, Jean D A; Carruthers, Alastair

2005-11-01

Until recently, deep facial sculpting was exclusively the domain of surgical interventions. Recent advances in the available array of dermal and subdermal fillers combined with an esthetic appreciation by both surgeons and nonsurgeons alike of the positive effect of filling the volume-depleted face have led to an expansion in the indications for the use of soft tissue augmenting agents. Subdermal support of the lateral two-thirds of the brow, the nasojugal fold, the malar and buccal fat pads, the lateral lip commissures, and the perioral region, including the pre-jowl sulcus, all restore youthful facial contour and harmony. An important advance in technique is the subdermal rather than the intradermal injection plane. "Instant" facial sculpting giving a brow-lift, cheek-lift, lip expansion, and perioral augmentation is possible using modern soft tissue augmenting agents. The softer, more relaxed appearance contrasts to the somewhat "pulled" appearance of subjects who have had surgical overcorrections. Treatments can be combined with botulinum toxin and other procedures if required. Newer advances in the use of fillers include the use of fillers injected in the subdermal plane for "lunchtime" facial sculpting. Using the modern esthetic filler compounds, which are biodegradable but longer lasting, subjects can have a "rehearsal" treatment or make it ongoing. Some individuals, such as those with human immunodeficiency virus (HIV)-related lipoatrophy or those who desire to obtain a longer-lasting effect, may elect to use a nonbiodegradable filling agent.

Radiofrequency-assisted Liposuction for Arm Contouring: Technique under Local Anesthesia

Directory of Open Access Journals (Sweden)

Spero Theodorou, MD

2013-08-01

Conclusions: In appropriately selected patients, RFAL arm contouring under local anesthesia represents an alternative procedure with acceptably low morbidity and high patient satisfaction. To achieve consistent results while minimizing complications, consideration to anatomic details, infiltration of the local anesthetic, and application of the radiofrequency energy must be given.

Comparison of the external physical damages between laser-assisted and mechanical immobilized human sperm using scanning electronic microscopy.

Directory of Open Access Journals (Sweden)

David Y L Chan

Full Text Available We aim to visualize the external physical damages and distinct external phenotypic effects between mechanical and laser-assisted immobilized human spermatozoa using scanning electronic microscopy (SEM. Human spermatozoa were immobilized mechanically or with laser assistance for SEM examination and the membrane integrities were checked on both types of immobilized spermatozoa. We found evidence of external damages at SEM level on mechanically kinked sperm, but not on laser-assisted immobilized sperm. Although no external damage was found on laser-assist immobilized sperm, there were two distinct types of morphological changes when spermatozoa were stricken by infra-red laser. Coiled tails were immediately formed when Laser pulse was applied to the sperm end piece area, whereas laser applied to the sperm principal piece area resulted in a sharp bend of sperm tails. Sperm immobilized by laser did not exhibit any morphological change if the laser did not hit within the on-screen central target zone or if the laser hit the sperm mid piece or head. Our modified membrane integrity assay revealed that the external membrane of more than half of the laser-assisted immobilized sperm remained intact. In conclusion, mechanical immobilization produced membrane damages whilst laser-assisted immobilization did not result in any external membrane damages besides morphological changes at SEM level.

Influencing Factors and Workpiece's Microstructure in Laser-Assisted Milling of Titanium

Science.gov (United States)

Wiedenmann, R.; Liebl, S.; Zaeh, M. F.

Today's lightweight components have to withstand increasing mechanical and thermal loads. Therefore, advanced materials substitute conventional materials like steel or aluminum alloys. Using these high-performance materials the associated costs become prohibitively high. This paper presents the newest fundamental investigations on the hybrid process 'laser-assisted milling' which is an innovative technique to process such materials. The focus is on the validation of a numerical database for a CAD/CAM process control unit which is calculated by using simulation. Prior to that, the influencing factors on a laser-assisted milling process are systematically investigated using Design of Experiments (DoE) to identify the main influencing parameters coming from the laser and the milling operation.

Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

International Nuclear Information System (INIS)

Aronne, Antonio; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Depero, Laura E.; Fanelli, Esther; Federici, Stefania; Massoli, Patrizio; Vicari, Luciano R.M.

2015-01-01

Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence

Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

Energy Technology Data Exchange (ETDEWEB)

Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Bloisi, Francesco, E-mail: bloisi@na.infn.it [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy); Calabria, Raffaela; Califano, Valeria [Istituto Motori – CNR, Naples (Italy); Depero, Laura E. [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Federici, Stefania [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Massoli, Patrizio [Istituto Motori – CNR, Naples (Italy); Vicari, Luciano R.M. [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy)

2015-05-01

Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

Laser-assisted lip repositioning surgery: Novel approach to treat gummy smile

Directory of Open Access Journals (Sweden)

Sana Farista

2017-01-01

Full Text Available Excessive gingival display (EGD resulting in a “gummy smile” is a major esthetic concern with ramifications in an individual's personal and social life. Numerous treatment modalities have been used for the correction of EGD. The present case report describes the successful treatment of a young woman with an excess gingival display caused by a hyperactive upper lip and a mild vertical maxillary excess that was treated with a laser-assisted lip repositioning surgical technique accompanied by gingival recontouring. The procedure was accomplished by laser-assisted removal, through scraping a strip of mucosa from the maxillary buccal vestibule and suturing the mucosa of the lip to the mucogingival junction. This technique resulted in shortened vestibule and restricted the muscle pull of the elevator muscles of the lip, thereby reducing gingival display when the patient smiles. Laser-assisted lip repositioning surgery can be a viable, minimally invasive alternative to orthognathic surgery.

Laser assisted embedding of nanoparticles into metallic materials

International Nuclear Information System (INIS)

Lin Dong; Suslov, Sergey; Ye Chang; Liao Yiliang; Liu, C. Richard; Cheng, Gary J.

2012-01-01

This paper reports a methodology of half-embedding nanoparticles into metallic materials. Transparent and opaque nanoparticles are chosen to demonstrate the process of laser assisted nanoparticle embedding. Dip coating method is used to coat transparent or opaque nanoparticle on the surface of metallic material. Nanoparticles are embedded into substrate by laser irradiation. In this study, the mechanism and process of nanoparticle embedding are investigated. It is found both transparent and opaque nanoparticles embedding are with high densities and good uniformities.

Microstructure-sensitive flow stress modeling for force prediction in laser assisted milling of Inconel 718

Directory of Open Access Journals (Sweden)

Pan Zhipeng

2017-01-01

Full Text Available Inconel 718 is a typical hard-to-machine material that requires thermally enhanced machining technology such as laser-assisted milling. Based upon finite element analysis, this study simulates the forces in the laser-assisted milling process of Inconel 718 considering the effects of grain growth due to γ' and γ" phases. The γ" phase is unstable and becomes the δ phase, which is likely to precipitate at a temperature over 750 °C. The temperature around the center of spot in the experiments is 850 °C, so the phase transformation and grain growth happen throughout the milling process. In the analysis, this study includes the microstructure evolution while accounting for the effects of dynamic recrystallization and grain growth through the Avrami model. The grain growth reduces the yield stress and flow stress, which improves the machinability. In finite element analysis (FEA, several boundary conditions of temperature varying with time are defined to simulate the movement of laser spot, and the constitutive model is described by Johnson-Cook equation. In experiments, this study collects three sets of cutting forces and finds that the predicted values are in close agreements with measurements especially in feed direction, in which the smallest error is around 5%. In another three simulations, this study also examines the effect of laser preheating on the cutting forces by comparison with a traditional milling process without laser assist. When the laser is off, the forces increase in all cases, which prove the softening effect of laser-assisted milling. In addition, when the axial depth of milling increases, the laser has a more significant influence, especially in axial direction, in which the force with laser is more than 18% smaller than the one without laser. Overall, this study validates the influence of laser-assisted milling on Inconel 718 by predicting the cutting forces in FEA.

Characteristics of laser assisted machining for silicon nitride ceramic according to machining parameters

International Nuclear Information System (INIS)

Kim, Jong Do; Lee, Su Jin; Suh, Jeong

2011-01-01

This paper describes the Laser Assisted Machining (LAM) that cuts and removes softened parts by locally heating the ceramic with laser. Silicon nitride ceramics can be machined with general machining tools as well, because YSiAlON, which was made up ceramics, is soften at about 1,000 .deg. C. In particular, the laser, which concentrates on highly dense energy, can locally heat materials and very effectively control the temperature of the heated part of specimen. Therefore, this paper intends to propose an efficient machining method of ceramic by deducing the machining governing factors of laser assisted machining and understanding its mechanism. While laser power is the machining factor that controls the temperature, the CBN cutting tool could cut the material more easily as the material gets deteriorated from the temperature increase by increasing the laser power, but excessive oxidation can negatively affect the quality of the material surface after machining. As the feed rate and cutting depth increase, the cutting force increases and tool lifespan decreases, but surface oxidation also decreases. In this experiment, the material can be cut to 3 mm of cutting depth. And based on the results of the experiment, the laser assisted machining mechanism is clarified

Contouring variability of human- and deformable-generated contours in radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Gardner, Stephen J; Wen, Ning; Kim, Jinkoo; Liu, Chang; Pradhan, Deepak; Aref, Ibrahim; Cattaneo, Richard II; Vance, Sean; Movsas, Benjamin; Chetty, Indrin J; Elshaikh, Mohamed A

2015-01-01

This study was designed to evaluate contouring variability of human-and deformable-generated contours on planning CT (PCT) and CBCT for ten patients with low-or intermediate-risk prostate cancer. For each patient in this study, five radiation oncologists contoured the prostate, bladder, and rectum, on one PCT dataset and five CBCT datasets. Consensus contours were generated using the STAPLE method in the CERR software package. Observer contours were compared to consensus contour, and contour metrics (Dice coefficient, Hausdorff distance, Contour Distance, Center-of-Mass [COM] Deviation) were calculated. In addition, the first day CBCT was registered to subsequent CBCT fractions (CBCTn: CBCT2–CBCT5) via B-spline Deformable Image Registration (DIR). Contours were transferred from CBCT1 to CBCTn via the deformation field, and contour metrics were calculated through comparison with consensus contours generated from human contour set. The average contour metrics for prostate contours on PCT and CBCT were as follows: Dice coefficient—0.892 (PCT), 0.872 (CBCT-Human), 0.824 (CBCT-Deformed); Hausdorff distance—4.75 mm (PCT), 5.22 mm (CBCT-Human), 5.94 mm (CBCT-Deformed); Contour Distance (overall contour)—1.41 mm (PCT), 1.66 mm (CBCT-Human), 2.30 mm (CBCT-Deformed); COM Deviation—2.01 mm (PCT), 2.78 mm (CBCT-Human), 3.45 mm (CBCT-Deformed). For human contours on PCT and CBCT, the difference in average Dice coefficient between PCT and CBCT (approx. 2%) and Hausdorff distance (approx. 0.5 mm) was small compared to the variation between observers for each patient (standard deviation in Dice coefficient of 5% and Hausdorff distance of 2.0 mm). However, additional contouring variation was found for the deformable-generated contours (approximately 5.0% decrease in Dice coefficient and 0.7 mm increase in Hausdorff distance relative to human-generated contours on CBCT). Though deformable contours provide a reasonable starting point for contouring

The Development of Contour Interpolation: Evidence from Subjective Contours

Science.gov (United States)

Hadad, Bat-Sheva; Maurer, Daphne; Lewis, Terri L.

2010-01-01

Adults are skilled at perceiving subjective contours in regions without any local image information (e.g., [Ginsburg, 1975] and [Kanizsa, 1976]). Here we examined the development of this skill and the effect thereon of the support ratio (i.e., the ratio of the physically specified contours to the total contour length). Children (6-, 9-, and…

Rejuvenecimiento facial en "doble sigma" "Double ogee" facial rejuvenation

Directory of Open Access Journals (Sweden)

O. M. Ramírez

2007-03-01

. Este arco conecta con la convexidad superior del tercio medio facial que se une con la concavidad de la porción inferior del tercio medio (arco inferior. Los paciente con un considerable envejecimiento y ptosis de las estructuras centrales faciales se pueden beneficiar en la mayoría de los casos de nuestro abordaje endoscópico. Las cejas, las comisuras de los párpados, de los tejidos blandos nasoglaberlares, los surcos nasolabiales, la nariz, las mejillas, el ángulo de la boca y los "jowls" (mejillas de bulldog se pueden tratar con eficacia mediante este abordaje. También las ojeras y los hundimientos orbitarios inferiores. Es eficaz también en ritidectomías secundarias o terciarias que requieren rejuvenecimiento cutáneo simultaneo y para cuando se precisa aumento de los tejidos blandos así como en las desproporciones esqueléticas y de los tejidos blandos. Las estructuras óseas expuestas pueden ser aumentadas o reducidas según convenga. Recomendamos este abordaje cuando hay que cambiar o extirpar implantes faciales aloplásticos. Los procedimientos endoscópicos de la frente y del tercio medio facial permiten la reconstrucción del "Doble Sigma" que se asocia a un aspecto juvenil.Subperiosteal techniques describes by Tessier have revolutionized the treatment of the aging face advocating this approach to treat early signs of aging in young and middleage patients. Psillakis refines the technique further and Ramirez describes a safer and more effective method of subperiosteal lifting, so that this technique could be applied across the full spectrum of facial aging. The introduction of the endoscope in the treatment of facial rejuvenation ushered in a new era in Aesthetic Surgery. Today, endoscopically assisted subperiosteal undermining of the upper, middle and lower face can provide a means for repositioning the sagging facial soft tissues in addition to augmentation of the craniofacial skeleton, with a reduced preoperative facial edema, minimal injury to the

CdS thin films prepared by laser assisted chemical bath deposition

International Nuclear Information System (INIS)

Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A.; Krishnan, B.; Avellaneda, D.; Castillo, G.A.; Das Roy, T.K.; Shaji, S.

2015-01-01

Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties

CdS thin films prepared by laser assisted chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

2015-05-01

Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties.

FaceWarehouse: a 3D facial expression database for visual computing.

Science.gov (United States)

Cao, Chen; Weng, Yanlin; Zhou, Shun; Tong, Yiying; Zhou, Kun

2014-03-01

We present FaceWarehouse, a database of 3D facial expressions for visual computing applications. We use Kinect, an off-the-shelf RGBD camera, to capture 150 individuals aged 7-80 from various ethnic backgrounds. For each person, we captured the RGBD data of her different expressions, including the neutral expression and 19 other expressions such as mouth-opening, smile, kiss, etc. For every RGBD raw data record, a set of facial feature points on the color image such as eye corners, mouth contour, and the nose tip are automatically localized, and manually adjusted if better accuracy is required. We then deform a template facial mesh to fit the depth data as closely as possible while matching the feature points on the color image to their corresponding points on the mesh. Starting from these fitted face meshes, we construct a set of individual-specific expression blendshapes for each person. These meshes with consistent topology are assembled as a rank-3 tensor to build a bilinear face model with two attributes: identity and expression. Compared with previous 3D facial databases, for every person in our database, there is a much richer matching collection of expressions, enabling depiction of most human facial actions. We demonstrate the potential of FaceWarehouse for visual computing with four applications: facial image manipulation, face component transfer, real-time performance-based facial image animation, and facial animation retargeting from video to image.

LASER CUTTING MACHINES FOR 3-D THIN SHEET PARTS

Directory of Open Access Journals (Sweden)

Miroslav RADOVANOVIC

2012-11-01

Full Text Available Laser cutting machines are used for precise contour cutting thin sheet. In industrial application nowadays various types and construction of laser cutting machines can be met. For contour cutting 3-D thin sheet parts laser cutting machines with rotation movements and laser robots are used. Laser generates the light beam, that presents a tool in working process. Application of laser cutting machines made possible good quality of products, flexibility of production and enlargement of economy

Laser-assisted cartilage reshaping: in vitro and in vivo animal studies

Science.gov (United States)

Wang, Zhi; Pankratov, Michail M.; Perrault, Donald F., Jr.; Shapshay, Stanley M.

1995-05-01

Correction of cartilaginous defects in the head and neck area remains a challenge for the surgeon. This study investigated a new technique for laser-assisted cartilage reshaping. The pulsed 1.44 micrometers Nd:YAG laser was used in vitro and in vivo experiments to irradiate cartilage to change it's shape without carbonization or vaporization of tissue. Two watts of average power in non contact manner was used to irradiate and reshape the cartilage. The extracted reshaped cartilage specimens underwent testing of elastic force with a computer assisted measurement system that recorded the changes in elastic force in the specimens from 1 hr to 11 days post-irradiation. An animal model of defective tracheal cartilage (collapsed tracheal wall) was created, allowed to heal for 6 weeks and then corrected endoscopically with the laser-assisted technique. The results of the in vitro and in vivo investigations demonstrated that it was possible to alter the cartilage and that cartilage would retain its new shape. The clinical significance of the technique is evident and warrants further animal studies and clinical trials.

Study on the effect of thermal property of metals in ultrasonic-assisted laser machining

International Nuclear Information System (INIS)

Lee, Hu Seung; Kim, Gun Woo; Park, Jong Eun; Cho, Sung Hak; Yang, Min Yang; Park, Jong Kweon

2015-01-01

The laser machining process has been proposed as an advanced process for the selective fabrication of electrodes without a mask. In this study, we adapt laser machining to metals that have different thermal properties. Based on the results, the metals exhibit a different surface morphology, heat-affected zone (HAZ), and a recast layer around the machined surface according to their thermal conductivity, boiling point, and thermal diffusivity. Then, we apply ultrasonic-assisted laser machining to remove the recast layer. The ultrasonic-assisted laser machining exhibits a better surface quality in metals with higher diffusivity than those having lower diffusivity

Laser assisted decontamination of nuclear fuel elements

International Nuclear Information System (INIS)

Padma Nilaya, J.; Biswas, Dhruba J.; Kumar, Aniruddha

2010-04-01

Laser assisted removal of loosely bound fuel particulates from the clad surface following the process of pellet loading has decided advantages over conventional methods. It is a dry and noncontact process that generates very little secondary waste and can occur inside a glove box without any manual interference minimizing the possibility of exposure to personnel. The rapid rise of the substrate/ particulate temperature owing to the absorption of energy from the incident laser pulse results in a variety of processes that may lead to the expulsion of the particulates. As a precursor to the cleaning of the fuel elements, initial experiments were carried out on contamination simulated on commonly used clad surfaces to gain a first hand experience on the various laser parameters for which as efficient cleaning can be obtained without altering the properties of the clad surface. The cleaning of a dummy fuel element was subsequently achieved in the laboratory by integrating the laser with a work station that imparted simultaneous rotational and linear motion to the fuel element. (author)

Design of a femtosecond laser assisted tomographic atom probe

International Nuclear Information System (INIS)

Gault, B.; Vurpillot, F.; Vella, A.; Gilbert, M.; Menand, A.; Blavette, D.; Deconihout, B.

2006-01-01

A tomographic atom probe (TAP) in which the atoms are field evaporated by means of femtosecond laser pulses has been designed. It is shown that the field evaporation is assisted by the laser field enhanced by the subwavelength dimensions of the specimen without any significant heating of the specimen. In addition, as compared with the conventional TAP, due to the very short duration of laser pulses, no spread in the energy of emitted ions is observed, leading to a very high mass resolution in a straight TAP in a wide angle configuration. At last, laser pulses can be used to bring the intense electric field required for the field evaporation on poor conductive materials such as intrinsic Si at low temperature. In this article, the performance of the laser TAP is described and illustrated through the investigation of metals, oxides, and silicon materials

Diode Laser Assisted Filament Winding of Thermoplastic Matrix Composites

Science.gov (United States)

Quadrini, Fabrizio; Squeo, Erica Anna; Prosperi, Claudia

2010-01-01

A new consolidation method for the laser-assisted filament winding of thermoplastic prepregs is discussed: for the first time a diode laser is used, as well as long glass fiber reinforced polypropylene prepregs. A consolidation apparatus was built by means of a CNC motion table, a stepper motor and a simple tensioner. Preliminary tests were performed in a hoop winding configuration: only the winding speed was changed, and all the other process parameters (laser power, distance from the laser focus, consolidation force) were kept constant. Small wound rings with an internal diameter of 25 mm were produced and compression tests were carried out to evaluate the composite agglomeration in dependence of the winding speed. At lower winding speeds, a strong interpenetration of adjacent layers was observed.

The study on force, surface integrity, tool life and chip on laser assisted machining of inconel 718 using Nd:YAG laser source.

Science.gov (United States)

Venkatesan, K

2017-07-01

Inconel 718, a high-temperature alloy, is a promising material for high-performance aerospace gas turbine engines components. However, the machining of the alloy is difficult owing to immense shear strength, rapid work hardening rate during turning, and less thermal conductivity. Hence, like ceramics and composites, the machining of this alloy is considered as difficult-to-turn materials. Laser assisted turning method has become a promising solution in recent years to lessen cutting stress when materials that are considered difficult-to-turn, such as Inconel 718 is employed. This study investigated the influence of input variables of laser assisted machining on the machinability aspect of the Inconel 718. The comparison of machining characteristics has been carried out to analyze the process benefits with the variation of laser machining variables. The laser assisted machining variables are cutting speeds of 60-150 m/min, feed rates of 0.05-0.125 mm/rev with a laser power between 1200 W and 1300 W. The various output characteristics such as force, roughness, tool life and geometrical characteristic of chip are investigated and compared with conventional machining without application of laser power. From experimental results, at a laser power of 1200 W, laser assisted turning outperforms conventional machining by 2.10 times lessening in cutting force, 46% reduction in surface roughness as well as 66% improvement in tool life when compared that of conventional machining. Compared to conventional machining, with the application of laser, the cutting speed of carbide tool has increased to a cutting condition of 150 m/min, 0.125 mm/rev. Microstructural analysis shows that no damage of the subsurface of the workpiece.

Investigations into ultraviolet matrix-assisted laser desorption

Energy Technology Data Exchange (ETDEWEB)

Heise, Theodore W. [Iowa State Univ., Ames, IA (United States)

1993-07-01

Matrix-assisted laser desorption (MALD) is a technique for converting large biomolecules into gas phase ions. Some characteristics of the commonly used uv matrices are determined. Solubilities in methanol range from 0.1 to 0.5 M. Solid phase absorption spectra are found to be similar to solution, but slightly red-shifted. Acoustic and quartz crystal microbalance signals are investigated as possible means of uv-MALD quantitation. Evidence for the existence of desorption thresholds is presented. Threshold values are determined to be in the range of 2 to 3 MW/cm². A transient imaging technique based on laser-excited fluorescence for monitoring MALD plumes is described. Sensitivity is well within the levels required for studying matrix-assisted laser desorption, where analyte concentrations are significantly lower than those in conventional laser desorption. Results showing the effect of film morphology, particularly film thickness, on plume dynamics are presented. In particular, MALD plumes from thicker films tend to exhibit higher axial velocities. Fluorescent labeling of protein and of DNA is used to allow imaging of their uv-MALD generated plumes. Integrated concentrations are available with respect to time, making it possible to assess the rate of fragmentation. The spatial and temporal distributions are important for the design of secondary ionization schemes to enhance ion yields and for the optimization of ion collection in time-of-flight MS instruments to maximize resolution. Such information could also provide insight into whether ionization is closely associated with the desorption step or whether it is a result of subsequent collisions with the matrix gas (e.g., proton transfer). Although the present study involves plumes in a normal atmosphere, adaptation to measurements in vacuum (e.g., inside a mass spectrometer) should be straightforward.

Retrospective single center study of the efficacy of large spot 532 nm laser for the treatment of facial capillary malformations in 44 patients with the use of three-dimensional image analysis.

Science.gov (United States)

Kwiek, Bartłomiej; Rożalski, Michał; Kowalewski, Cezary; Ambroziak, Marcin

2017-10-01

We wanted to asses the efficacy of large spot 532 nm laser for the treatment of facial capillary malformations with the use of three-dimensional (3D) image analysis. Retrospective single center study on previously non-treated patients with facial capillary malformations (CM) was performed. A total of 44 consecutive Caucasian patients aged 5-66 were included. Patients had 3D photography performed before and after and had at least one single session of treatment with 532 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser with contact cooling, fluencies ranging from 8 to 11.5 J/cm 2 , pulse duration ranging from 5 to 9 milliseconds and spot size ranging from 5 to 10 mm. Objective analysis of percentage improvement based on 3D digital assessment of combined color and area improvement (global clearance effect [GCE]) were performed. Median maximal improvement achieved during the treatment (GCE max ) was 70.4%. Mean number of laser procedures required to achieve this improvement was 7.1 (ranging from 2 to 14)). Improvement of minimum 25% (GCE 25) was achieved by all patients, of minimum 50% (GCE 50) by 77.3%, of minimum 75% (GCE 75) by 38.6%, and of minimum 90% (GCE 90) by 13.64. Large spot 532 nm laser is highly effective in the treatment of facial CM. 3D color and area image analysis provides an objective method to compare different methods of facial CM treatment in future studies. Lasers Surg. Med. 49:743-749, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

UV laser-assisted fabrication of ridge waveguides in lithium niobate crystals

OpenAIRE

Sones, C.L.; Ying, C.Y.J.; Eason, R.W.; Mailis, S.; Ganguly, P.; Soergel, E.

2010-01-01

We present a UV laser-assisted method for the fabrication of ridge waveguides in lithium niobate. The UV laser irradiation step provides the refractive index change required for the vertical light confinement in the waveguide and also defines the ferroelectric domain pattern which produces the ridge structures after chemical etching.

Laser-assisted fibrinogen bonding of umbilical vein grafts.

Science.gov (United States)

Oz, M C; Williams, M R; Souza, J E; Dardik, H; Treat, M R; Bass, L S; Nowygrod, R

1993-06-01

Despite success with autologous tissue welding, laser welding of synthetic vascular prostheses has not been possible. The graft material appears inert and fails to allow the collagen breakdown and electrostatic bonding that results in tissue welding. To develop a laser welding system for graft material, we repaired glutaraldehyde-tanned human umbilical cord vein graft incisions using laser-assisted fibrinogen bonding (LAFB) technology. Modified umbilical vein graft was incised transversely (1.2 cm). Incisions were repaired using sutures, laser energy alone, or LAFB. For LAFB, indocyanine green dye was mixed with human fibrinogen and the compound applied with forceps onto the weld site prior to exposure to 808 nm diode laser energy (power density 4.8 W/cm 2). Bursting pressures for sutured repairs (126.6 +/- 23.4 mm Hg) were similar to LAFB anastomoses (111.6 +/- 55.0 mm Hg). No evidence of collateral thermal injury to the graft material was noted. In vivo evaluation of umbilical graft bonding with canine arteries demonstrates that LAFB can reliably reinforce sutured anastomoses. The described system for bonding graft material with laser exposed fibrinogen may allow creation or reinforcement of vascular anastomoses in procedures where use of autologous tissue is not feasible.

Facial aging: A clinical classification

Directory of Open Access Journals (Sweden)

Shiffman Melvin

2007-01-01

Full Text Available The purpose of this classification of facial aging is to have a simple clinical method to determine the severity of the aging process in the face. This allows a quick estimate as to the types of procedures that the patient would need to have the best results. Procedures that are presently used for facial rejuvenation include laser, chemical peels, suture lifts, fillers, modified facelift and full facelift. The physician is already using his best judgment to determine which procedure would be best for any particular patient. This classification may help to refine these decisions.

Granuloma Faciale Treatment: A Systematic Review

Directory of Open Access Journals (Sweden)

Claudia Lindhaus

2017-10-01

Full Text Available Granuloma faciale is an uncommon benign chronic dermatosis characterized by reddish-brown to violaceous asymptomatic plaques appearing predominantly on the face. The pathogenesis of granuloma faciale remains unclear, and it is frequently unresponsive to therapy. This systematic review aims to summarize all recent publications on the management of granuloma faciale. The publications are mainly individual case reports, small case series and a few retrospective studies. Treatment options included topical, intralesional and systemic corticosteroids, topical pimecrolimus and tacrolimus, topical and systemic dapsone, systemic hydroxychloroquine, clofazimine, and tumour necrosis factor-alpha inhibitors. More invasive therapies using lasers as well as cryosurgery and surgery were also reported. Topical glucocorticosteroids and tacrolimus remain treatments of first choice, possibly supplemented by topical dapsone.

One-year follow-up of femtosecond laser-assisted penetrating keratoplasty

Directory of Open Access Journals (Sweden)

Tan JCH

2013-02-01

Full Text Available Johnson Choon-Hwai Tan, Wee-Jin HengNational Healthcare Group Eye Institute, Tan Tock Seng Hospital, SingaporeBackground: The purpose of this report is to describe the initial outcomes of femtosecond laser-assisted penetrating keratoplasty.Methods: This retrospective surgical case series consisted of 10 eyes from 10 patients undergoing penetrating keratoplasty at a tertiary center. Femtosecond laser was used to perform a zig-square incision on the donor cornea with matched dimensions on the recipient cornea. Outcomes measured included: unaided visual acuity and best spectacle-corrected visual acuity preoperatively and at one, 3, 6, and 12 months postoperatively; manifest refractive and topographic astigmatism at 3, 6, and 12 months postoperatively; and endothelial cell density loss, calculated at the end of the one-year follow-up period.Results: At one-year follow-up, there was an improvement in unaided visual acuity from a mean preoperative logMAR of 1.67 to 0.44, and best spectacle-corrected visual acuity from a mean preoperative logMAR of 1.33 to 0.13. By postoperative month 3, mean manifest refractive and topographic astigmatism was 2.31 ± 1.41 D and 2.59 ± 1.57 D, respectively. The mean reduction in endothelial cell density was 20.7% after one year of follow-up.Conclusion: Femtosecond laser-assisted penetrating keratoplasty provided a good visual outcome and early visual rehabilitation due to precise graft-host alignment and reduced astigmatism in the early postoperative months.Keywords: penetrating keratoplasty, femtosecond laser-assisted keratoplasty

Joint classification and contour extraction of large 3D point clouds

Science.gov (United States)

Hackel, Timo; Wegner, Jan D.; Schindler, Konrad

2017-08-01

We present an effective and efficient method for point-wise semantic classification and extraction of object contours of large-scale 3D point clouds. What makes point cloud interpretation challenging is the sheer size of several millions of points per scan and the non-grid, sparse, and uneven distribution of points. Standard image processing tools like texture filters, for example, cannot handle such data efficiently, which calls for dedicated point cloud labeling methods. It turns out that one of the major drivers for efficient computation and handling of strong variations in point density, is a careful formulation of per-point neighborhoods at multiple scales. This allows, both, to define an expressive feature set and to extract topologically meaningful object contours. Semantic classification and contour extraction are interlaced problems. Point-wise semantic classification enables extracting a meaningful candidate set of contour points while contours help generating a rich feature representation that benefits point-wise classification. These methods are tailored to have fast run time and small memory footprint for processing large-scale, unstructured, and inhomogeneous point clouds, while still achieving high classification accuracy. We evaluate our methods on the semantic3d.net benchmark for terrestrial laser scans with >109 points.

Diode Laser Assisted Filament Winding of Thermoplastic Matrix Composites

Directory of Open Access Journals (Sweden)

Claudia Prosperi

2010-01-01

Full Text Available A new consolidation method for the laser-assisted filament winding of thermoplastic prepregs is discussed: for the first time a diode laser is used, as well as long glass fiber reinforced polypropylene prepregs. A consolidation apparatus was built by means of a CNC motion table, a stepper motor and a simple tensioner. Preliminary tests were performed in a hoop winding configuration: only the winding speed was changed, and all the other process parameters (laser power, distance from the laser focus, consolidation force were kept constant. Small wound rings with an internal diameter of 25 mm were produced and compression tests were carried out to evaluate the composite agglomeration in dependence of the winding speed. At lower winding speeds, a stronginterpenetration of adjacent layers was observed.

The study on force, surface integrity, tool life and chip on laser assisted machining of inconel 718 using Nd:YAG laser source

Directory of Open Access Journals (Sweden)

K. Venkatesan

2017-07-01

Full Text Available Inconel 718, a high-temperature alloy, is a promising material for high-performance aerospace gas turbine engines components. However, the machining of the alloy is difficult owing to immense shear strength, rapid work hardening rate during turning, and less thermal conductivity. Hence, like ceramics and composites, the machining of this alloy is considered as difficult-to-turn materials. Laser assisted turning method has become a promising solution in recent years to lessen cutting stress when materials that are considered difficult-to-turn, such as Inconel 718 is employed. This study investigated the influence of input variables of laser assisted machining on the machinability aspect of the Inconel 718. The comparison of machining characteristics has been carried out to analyze the process benefits with the variation of laser machining variables. The laser assisted machining variables are cutting speeds of 60–150 m/min, feed rates of 0.05–0.125 mm/rev with a laser power between 1200 W and 1300 W. The various output characteristics such as force, roughness, tool life and geometrical characteristic of chip are investigated and compared with conventional machining without application of laser power. From experimental results, at a laser power of 1200 W, laser assisted turning outperforms conventional machining by 2.10 times lessening in cutting force, 46% reduction in surface roughness as well as 66% improvement in tool life when compared that of conventional machining. Compared to conventional machining, with the application of laser, the cutting speed of carbide tool has increased to a cutting condition of 150 m/min, 0.125 mm/rev. Microstructural analysis shows that no damage of the subsurface of the workpiece.

Nanoparticle assisted laser desorption/ionization mass spectrometry for small molecule analytes.

Science.gov (United States)

Abdelhamid, Hani Nasser

2018-03-01

Nanoparticle assisted laser desorption/ionization mass spectrometry (NPs-ALDI-MS) shows remarkable characteristics and has a promising future in terms of real sample analysis. The incorporation of NPs can advance several methods including surface assisted LDI-MS, and surface enhanced LDI-MS. These methods have advanced the detection of many thermally labile and nonvolatile biomolecules. Nanoparticles circumvent the drawbacks of conventional organic matrices for the analysis of small molecules. In most cases, NPs offer a clear background without interfering peaks, absence of fragmentation of thermally labile molecules, and allow the ionization of species with weak noncovalent interactions. Furthermore, an enhancement in sensitivity and selectivity can be achieved. NPs enable straightforward analysis of target species in a complex sample. This review (with 239 refs.) covers the progress made in laser-based mass spectrometry in combination with the use of metallic NPs (such as AuNPs, AgNPs, PtNPs, and PdNPs), NPs consisting of oxides and chalcogenides, silicon-based NPs, carbon-based nanomaterials, quantum dots, and metal-organic frameworks. Graphical abstract An overview is given on nanomaterials for use in surface-assisted laser desorption/ionization mass spectrometry of small molecules.

Laser-assisted fixation of a nitinol stapes prosthesis.

Science.gov (United States)

Schrötzlmair, Florian; Suchan, Fabian; Pongratz, Thomas; Krause, Eike; Müller, Joachim; Sroka, Ronald

2018-02-01

Otosclerosis is an inner ear bone disease characterized by fixation of the stapes and consequently progressive hearing loss. One treatment option is the surgical replacement of the stapes by a prosthesis. When so called "smart materials" like nitinol are used, prosthesis fixation can be performed using a laser without manual crimping on the incus. However, specific laser-prosthesis interactions have not been described yet. The aim of the present study was to elucidate the thermo-mechanical properties of the NiTiBOND® prosthesis as a basis for handling instructions for laser-assisted prosthesis fixation. Closure of the NiTiBOND® prosthesis was induced ex vivo by either a diode laser emitting at λ = 940 nm or a CO 2 laser (λ = 10,600 nm). Total energy for closure was determined. Suitable laser parameters (pulse duration, power per pulse, distance between tip of the laser fiber and prosthesis) were assessed. Specific laser-prosthesis interactions were recorded. Especially the diode laser was found to be an appropriate energy source. A total energy deposit of 60 mJ by pulses in near contact application was found to be sufficient for prosthesis closure ex vivo. Energy should be transmitted through a laser fiber equipollent to the prosthesis band diameter. Specific deformation characteristics due to the zonal prosthesis composition have to be taken into account. NiTiBOND® stapes prosthesis can be closed by very little energy when appropriate energy sources like diode lasers are used, suggesting a relatively safe application in vivo. Lasers Surg. Med. 50:153-157, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Laser- and UV-assisted modification of polystyrene surfaces for control of protein adsorption and cell adhesion

International Nuclear Information System (INIS)

Pfleging, Wilhelm; Torge, Maika; Bruns, Michael; Trouillet, Vanessa; Welle, Alexander; Wilson, Sandra

2009-01-01

An appropriate choice of laser and process parameters enables new approaches for the fabrication of polymeric lab-on-chip devices with integrated functionalities. We will present our current research results in laser-assisted modification of polystyrene (PS) with respect to the fabrication of polymer devices for cell culture applications. For this purpose laser micro-patterning of PS and subsequent surface functionalization was investigated as function of laser and process parameters. A high power ArF-excimer laser radiation source with a pulse length of 19 ns as well as a high repetition ArF-excimer laser source with a pulse length of 5 ns were used in order to study the influence of laser pulse length on laser-induced surface oxidation. The change in surface chemistry was characterized by X-ray photoelectron spectroscopy and contact angle measurements. The difference between laser-assisted modification versus UV-lamp assisted modification was investigated. A photolytic activation of specific areas of the polymer surface and subsequent oxidization in oxygen or ambient air leads to a chemically modified polymer surface bearing carboxylic acid groups well-suited for controlled competitive protein adsorption or protein immobilization. Finally, distinct areas for cell growth and adhesion are obtained

Multi-scale graphene patterns on arbitrary substrates via laser-assisted transfer-printing process

KAUST Repository

Park, J. B.; Yoo, J.-H.; Grigoropoulos, C. P.

2012-01-01

A laser-assisted transfer-printing process is developed for multi-scale graphene patterns on arbitrary substrates using femtosecond laser scanning on a graphene/metal substrate and transfer techniques without using multi-step patterning processes

Energy-Based Facial Rejuvenation: Advances in Diagnosis and Treatment.

Science.gov (United States)

Britt, Christopher J; Marcus, Benjamin

2017-01-01

The market for nonsurgical, energy-based facial rejuvenation techniques has increased exponentially since lasers were first used for skin rejuvenation in 1983. Advances in this area have led to a wide range of products that require the modern facial plastic surgeon to have a large repertoire of knowledge. To serve as a guide for current trends in the development of technology, applications, and outcomes of laser and laser-related technology over the past 5 years. We performed a review of PubMed from January 1, 2011, to March 1, 2016, and focused on randomized clinical trials, meta-analyses, systematic reviews, and clinical practice guidelines including case control, case studies and case reports when necessary, and included 14 articles we deemed landmark articles before 2011. Three broad categories of technology are leading non-energy-based rejuvenation technology: lasers, light therapy, and non-laser-based thermal tightening devices. Laser light therapy has continued to diversify with the use of ablative and nonablative resurfacing technologies, fractionated lasers, and their combined use. Light therapy has developed for use in combination with other technologies or stand alone. Finally, thermally based nonlaser skin-tightening devices, such as radiofrequency (RF) and intense focused ultrasonography (IFUS), are evolving technologies that have changed rapidly over the past 5 years. Improvements in safety and efficacy for energy-based treatment have expanded the patient base considering these therapies viable options. With a wide variety of options, the modern facial plastic surgeon can have a frank discussion with the patient regarding nonsurgical techniques that were never before available. Many of these patients can now derive benefit from treatments requiring significantly less downtime than before while the clinician can augment the treatment to maximize benefit to fit the patient's time schedule.

An experimental investigation of pulsed laser-assisted machining of AISI 52100 steel

Science.gov (United States)

Panjehpour, Afshin; Soleymani Yazdi, Mohammad R.; Shoja-Razavi, Reza

2014-11-01

Grinding and hard turning are widely used for machining of hardened bearing steel parts. Laser-assisted machining (LAM) has emerged as an efficient alternative to grinding and hard turning for hardened steel parts. In most cases, continuous-wave lasers were used as a heat source to cause localized heating prior to material removal by a cutting tool. In this study, an experimental investigation of pulsed laser-assisted machining of AISI 52100 bearing steel was conducted. The effects of process parameters (i.e., laser mean power, pulse frequency, pulse energy, cutting speed and feed rate) on state variables (i.e., material removal temperature, specific cutting energy, surface roughness, microstructure, tool wear and chip formation) were investigated. At laser mean power of 425 W with frequency of 120 Hz and cutting speed of 70 m/min, the benefit of LAM was shown by 25% decrease in specific cutting energy and 18% improvement in surface roughness, as compared to those of the conventional machining. It was shown that at constant laser power, the increase of laser pulse energy causes the rapid increase in tool wear rate. Pulsed laser allowed efficient control of surface temperature and heat penetration in material removal region. Examination of the machined subsurface microstructure and microhardness profiles showed no change under LAM and conventional machining. Continuous chips with more uniform plastic deformation were produced in LAM.

Overview of Facial Plastic Surgery and Current Developments

Science.gov (United States)

Chuang, Jessica; Barnes, Christian; Wong, Brian J. F.

2016-01-01

Facial plastic surgery is a multidisciplinary specialty largely driven by otolaryngology but includes oral maxillary surgery, dermatology, ophthalmology, and plastic surgery. It encompasses both reconstructive and cosmetic components. The scope of practice for facial plastic surgeons in the United States may include rhinoplasty, browlifts, blepharoplasty, facelifts, microvascular reconstruction of the head and neck, craniomaxillofacial trauma reconstruction, and correction of defects in the face after skin cancer resection. Facial plastic surgery also encompasses the use of injectable fillers, neural modulators (e.g., BOTOX Cosmetic, Allergan Pharmaceuticals, Westport, Ireland), lasers, and other devices aimed at rejuvenating skin. Facial plastic surgery is a constantly evolving field with continuing innovative advances in surgical techniques and cosmetic adjunctive technologies. This article aims to give an overview of the various procedures that encompass the field of facial plastic surgery and to highlight the recent advances and trends in procedures and surgical techniques. PMID:28824978

Frequency-comb-assisted broadband precision spectroscopy with cascaded diode lasers

DEFF Research Database (Denmark)

Liu, Junqiu; Brasch, Victor; Pfeiffer, Martin H. P.

2016-01-01

Frequency-comb-assisted diode laser spectroscopy, employing both the accuracy of an optical frequency comb and the broad wavelength tuning range of a tunable diode laser, has been widely used in many applications. In this Letter, we present a novel method using cascaded frequency agile diode lasers......, which allows us to extend the measurement bandwidth to 37.4 THz (1355-1630 nm) at megahertz resolution with scanning speeds above 1 THz/s. It is demonstrated as a useful tool to characterize a broadband spectrum for molecular spectroscopy, and in particular it enables us to characterize the dispersion...

Correction of Facial Deformity in Sturge–Weber Syndrome

Science.gov (United States)

Yamaguchi, Kazuaki; Lonic, Daniel; Chen, Chit

2016-01-01

Background: Although previous studies have reported soft-tissue management in surgical treatment of Sturge–Weber syndrome (SWS), there are few reports describing facial bone surgery in this patient group. The purpose of this study is to examine the validity of our multidisciplinary algorithm for correcting facial deformities associated with SWS. To the best of our knowledge, this is the first study on orthognathic surgery for SWS patients. Methods: A retrospective chart review included 2 SWS patients who completed the surgical treatment algorithm. Radiographic and clinical data were recorded, and a treatment algorithm was derived. Results: According to the Roach classification, the first patient was classified as type I presenting with both facial and leptomeningeal vascular anomalies without glaucoma and the second patient as type II presenting only with a hemifacial capillary malformation. Considering positive findings in seizure history and intracranial vascular anomalies in the first case, the anesthetic management was modified to omit hypotensive anesthesia because of the potential risk of intracranial pressure elevation. Primarily, both patients underwent 2-jaw orthognathic surgery and facial bone contouring including genioplasty, zygomatic reduction, buccal fat pad removal, and masseter reduction without major complications. In the second step, the volume and distribution of facial soft tissues were altered by surgical resection and reposition. Both patients were satisfied with the surgical result. Conclusions: Our multidisciplinary algorithm can systematically detect potential risk factors. Correction of the asymmetric face by successive bone and soft-tissue surgery enables the patients to reduce their psychosocial burden and increase their quality of life. PMID:27622111

Inhibition of enamel demineralisation using "Nd-YAG and diode laser assisted fluoride therapy".

Science.gov (United States)

Chand, B R; Kulkarni, S; Mishra, P

2016-02-01

This in vitro study was to evaluate the irradiation efficacy of the Diode laser and the Nd-YAG laser either un-assisted or assisted by acidulated phosphate fluoride (APF) treatment on enamel's acid resistance. Seventy-two enamel samples, obtained from 12 extracted human molars, were randomly assigned to 6 groups as follows: (1) Control (C); (2) Exposed to APF gel (F); (3) Diode laser (DL); (4) Irradiated with Diode laser through APF gel (DL/F); (5) Nd-YAG laser (NL) and (6) Irradiated with Nd-YAG laser through APF gel (NL/F). The specimens were individually demineralised in an acidified hydroxyethylcellulose system, and the acid resistance was evaluated by determining the calcium ion dissolution using atomic absorption spectrometry. The average concentration of the calcium ion determined in groups 1 to 6 was 901, 757, 736, 592, 497 and 416 parts per million micrograms/gram, respectively. The results showed that demineralisation in the NL/F group was significantly less than the other groups and the control group was significantly greater than the other groups (P laser irradiation, used alone or in combination with APF, in decreasing the enamel demineralisation was greater than all the other groups.

The Evaluation of Surface Integrity During Machining of Inconel 718 with Various Laser Assistance Strategies

Directory of Open Access Journals (Sweden)

Wojciechowski Szymon

2017-01-01

Full Text Available The paper is focused on the evaluation of surface integrity formed during turning of Inconel 718 with the application of various laser assistance strategies. The primary objective of the work was to determine the relations between the applied machining strategy and the obtained surface integrity, in order to select the effective cutting conditions allowing the obtainment of high surface quality. The carried out experiment included the machining of Inconel 718 in the conventional turning conditions, as well as during the continuous laser assisted machining and sequential laser assistance. The surface integrity was evaluated by the measurements of machined surface topographies, microstructures and the microhardness. Results revealed that surface integrity of Inconel 718 is strongly affected by the selected machining strategy. The significant improvement of the surface roughness formed during machining of Inconel 718, can be reached by the application of simultaneous laser heating and cutting (LAM.

Laser assisted bioprinting using a femtosecond laser with and without a gold transductive layer: a parametric study

Science.gov (United States)

Desrus, H.; Chassagne, B.; Catros, S.; Artiges, C.; Devillard, R.; Petit, S.; Deloison, F.; Fricain, J. C.; Guillemot, F.; Kling, R.

2016-03-01

Experimental results of femtosecond Laser Assisted Bioprinting (LAB) are reported on. Two set-up, used to print different model bioinks and keratinocytes cells line HaCaT, were studied: first one was using a femtosecond laser with low pulse energy and an absorbing gold layer, whereas the second one used high pulse energy enabling the removal of the absorbing layer. Printed drop diameter and resulting height of the bioink jet are then quantified as a function of the LAB parameters such as laser energy, focus spot location or numerical aperture.

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.

Femtosecond laser refractive surgery: small-incision lenticule extraction vs. femtosecond laser-assisted LASIK.

Science.gov (United States)

Lee, Jimmy K; Chuck, Roy S; Park, Choul Yong

2015-07-01

Small-incision lenticule extraction (SMILE) is a novel technique devised to correct refractive errors. SMILE circumvents excimer laser photoablation of cornea, as the stromal lenticule cut by femtosecond laser is removed manually. Smaller incisions and preservation of anterior corneal biomechanical strength have been suggested as some of the advantages of SMILE over femtosecond laser-assisted LASIK (FS-LASIK). In this review, we compared previous published results of SMILE and FS-LASIK. The advantage, efficacy and safety of SMILE are compared with FS-LASIK. SMILE achieved similar efficacy, predictability and safety as FS-LASIK. Greater preservations of corneal biomechanical strength and corneal nerves were observed in SMILE when compared with LASIK or PRK. Additionally, the incidence of postoperative dry eye syndrome was found to be less problematic in SMILE than in FS-LASIK. SMILE is a promising new surgery for refractive error correction. Prospective and retrospective studies of SMILE have shown that results of SMILE are similar to FS-LASIK. With advances in femtosecond laser technology, SMILE may gain greater acceptance in the future.

Collagen crosslinking for ectasia following PRK performed in excimer laser-assisted keratoplasty for keratoconus.

Science.gov (United States)

Spadea, Leopoldo

2012-01-01

To report the results of corneal collagen crosslinking (CXL) in a patient with corneal ectasia developed after excimer laser-assisted lamellar keratoplasty for keratoconus and a secondary photorefractive keratectomy (PRK) for residual refractive error. A 33-year-old woman, who had originally been treated for keratoconus in the right eye by excimer laser-assisted lamellar keratoplasty, subsequently had her residual ametropia treated by topographically guided, transepithelial excimer laser PRK. Five years after PRK, the patient developed corneal ectasia showing concomitant visual changes of best spectacle-corrected visual acuity (BSCVA) reduced to 20/33 with a refraction of -6.00 +6.00 × 30. The minimum corneal thickness at the ectasia apex was 406 µm. A treatment of riboflavin-UVA-induced corneal CXL was performed on the right eye. Two years after the CXL treatment, the right eye improved to 20/20 BSCVA with a refraction of plano +1.00 × 50 while exhibiting a clear lamellar graft. Corneal CXL provided safe and effective management of ectasia developed after excimer laser-assisted lamellar keratoplasty and PRK.

Surface-assisted laser desorption ionization mass spectrometry techniques for application in forensics.

Science.gov (United States)

Guinan, Taryn; Kirkbride, Paul; Pigou, Paul E; Ronci, Maurizio; Kobus, Hilton; Voelcker, Nicolas H

2015-01-01

Matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) is an excellent analytical technique for the rapid and sensitive analysis of macromolecules (>700 Da), such as peptides, proteins, nucleic acids, and synthetic polymers. However, the detection of smaller organic molecules with masses below 700 Da using MALDI-MS is challenging due to the appearance of matrix adducts and matrix fragment peaks in the same spectral range. Recently, nanostructured substrates have been developed that facilitate matrix-free laser desorption ionization (LDI), contributing to an emerging analytical paradigm referred to as surface-assisted laser desorption ionization (SALDI) MS. Since SALDI enables the detection of small organic molecules, it is rapidly growing in popularity, including in the field of forensics. At the same time, SALDI also holds significant potential as a high throughput analytical tool in roadside, work place and athlete drug testing. In this review, we discuss recent advances in SALDI techniques such as desorption ionization on porous silicon (DIOS), nano-initiator mass spectrometry (NIMS) and nano assisted laser desorption ionization (NALDI™) and compare their strengths and weaknesses with particular focus on forensic applications. These include the detection of illicit drug molecules and their metabolites in biological matrices and small molecule detection from forensic samples including banknotes and fingerprints. Finally, the review highlights recent advances in mass spectrometry imaging (MSI) using SALDI techniques. © 2014 Wiley Periodicals, Inc.

Stress assisted selective ablation of ITO thin film by picosecond laser

Science.gov (United States)

Farid, Nazar; Chan, Helios; Milne, David; Brunton, Adam; M. O'Connor, Gerard

2018-01-01

Fast selective pattering with high precession on 175 nm ITO thin film with IR ps lasers is investigated. Ablation parameters are optimized with detailed studies on the scribed depth, topography, and particle generation using AFM and SEM. A comparison of 10 and 150 ps laser revealed that the shorter pulse (10 ps) laser is more appropriate in selective and partial ablation; up to 20 nm resolution for controlled depth with multipulses having energy below the damage threshold is demonstrated. The experimental results are interpreted to involve stress assisted ablation mechanism for the 10 ps laser while thermal ablation along with intense melting occurs for 150 ps laser. The transition between these regimes is estimated to occur at approximately 30 ps.

Laser-assisted growth of carbon nanotubes on laser-patterned substrates and inside sealed micro-channels

NARCIS (Netherlands)

Burgt, Y. van de; Bellouard, Y.

2014-01-01

Carbon nanotube assemblies can be used for specific applications such as sensors and filters. We present a method and proof-of-concept to directly grow vertically-aligned carbon nanotube structures within sealed enclosures by means of a feedback-controlled laser-assisted chemical vapor deposition

Visualization of Uncertain Contour Trees

DEFF Research Database (Denmark)

Kraus, Martin

2010-01-01

Contour trees can represent the topology of large volume data sets in a relatively compact, discrete data structure. However, the resulting trees often contain many thousands of nodes; thus, many graph drawing techniques fail to produce satisfactory results. Therefore, several visualization methods...... were proposed recently for the visualization of contour trees. Unfortunately, none of these techniques is able to handle uncertain contour trees although any uncertainty of the volume data inevitably results in partially uncertain contour trees. In this work, we visualize uncertain contour trees...... by combining the contour trees of two morphologically filtered versions of a volume data set, which represent the range of uncertainty. These two contour trees are combined and visualized within a single image such that a range of potential contour trees is represented by the resulting visualization. Thus...

The Application of 3D Printing Technology for Simultaneous Orthognathic Surgery and Mandibular Contour Osteoplasty in the Treatment of Craniofacial Deformities.

Science.gov (United States)

Xiao, Yanju; Sun, Xiumei; Wang, Lin; Zhang, Yaoyao; Chen, Kai; Wu, Guomin

2017-12-01

Because of the limitation of specific preoperative design and surgical templates, orthognathic surgery and mandibular contour osteoplasty are generally performed in two stages. Three-dimensional printing technology has improved the accuracy of the surgery and results in good surgical predictability easily. This study aims to confirm the effectiveness, feasibility and precision of simultaneous mandibular contour osteoplasty and orthognathic surgery with the assistance of 3D printing technology. Ten patients, who were diagnosed with mandibular hypertrophy and bimaxillary deformities, were included in the study. In addition to conventional orthognathic surgery, mandibular angle ostectomy, mandibular outer cortex grinding or mandibular border ostectomy was designed for mandibular hypertrophy. Optimal osteotomy lines and simulated surgeries were designed according the 3D printing model of the mandible. Then, surgical templates were made on the 3D printing model. No muscle excision was performed in any patient. Preoperative, predicted and postoperative measurements were taken, including the gonial angle (Ar-Go-Me) and the mandibular width (Go-Go). All the patients had a reposeful postoperative recovery, with no indication of obvious infection, facial paralysis, osteonecrosis or bone displacement. The gonial angle was improved from 110.3° ± 11.1 to 121.3° ± 2.9, and the mandibular width was improved from 117.5 mm ± 6.8 to 111.9 mm ± 4.2. The discrepancies between simulation and postoperation of the left gonial angle, the right gonial angle and the mandibular width were 0.56° ± 0.22, 0.65° ± 0.3 and 0.49 mm ± 0.43, respectively. The results of our study illustrated the predictability, feasibility and reliability of simultaneous mandibular contour osteoplasty and orthognathic surgery with the assistance of 3D printing technology. Our technique could achieve functional improvement and an aesthetic profile at the same time. This journal requires

Facial sculpting: Comprehensive approach for aesthetic correction of round face

Directory of Open Access Journals (Sweden)

M K Thomas

2012-01-01

Full Text Available Context: Standards for an aesthetic face are dynamic. The current trend is towards a leaner looking face with preservation of the inverted triangle of youth. Procedures that have been reported to be employed for correction of a chubby face include buccal fat pad excision, facial liposuction and injection lipolysis. In addition to giving the face an aesthetic triangular cut, chin and malar augmentation may be performed. The rounded appearance at the angles may further be reduced by injection of Botulinum toxin into the masseter. Materials and Methods: Forty patients who presented to us for correction of chubby (round faces were analysed and treated by facial sculpting surgery, which included at least two of the procedures in combination. The procedures included facial liposuction, buccal fat pad excision, chin augmentation, malar augmentation and injection lipolysis. All cases were followed-up for a minimum of 6 months after surgery. Results: Aesthetic expectations of the patients were met in 39 cases, one patient complained of facial asymmetry following facial liposuction and was subjected to a touch-up injection lipolysis. Conclusions: A combination of procedures is necessary to give the face an attractive contour. All the individual procedures have stood the test of time and are safe, proven and are put in mainstream. However, a thorough analysis of the face preoperatively and then subjecting the patient to a combination of these procedures in a single surgical sitting has yielded good results as seen in this study.

Chemically assisted laser ablation ICP mass spectrometry.

Science.gov (United States)

Hirata, Takafumi

2003-01-15

A new laser ablation technique combined with a chemical evaporation reaction has been developed for elemental ratio analysis of solid samples using an inductively coupled plasma mass spectrometer (ICPMS). Using a chemically assisted laser ablation (CIA) technique developed in this study, analytical repeatability of the elemental ratio measurement was successively improved. To evaluate the reliability of the CLA-ICPMS technique, Pb/U isotopic ratios were determined for zircon samples that have previously been analyzed by other techniques. Conventional laser ablation for Pb/U shows a serious elemental fractionation during ablation mainly due to the large difference in elemental volatility between Pb and U. In the case of Pb/U ratio measurement, a Freon R-134a gas (1,1,1,2-tetrafluoroethane) was introduced into the laser cell as a fluorination reactant. The Freon gas introduced into the laser cell reacts with the ablated sample U, and refractory U compounds are converted to a volatile U fluoride compound (UF6) under the high-temperature condition at the ablation site. This avoids the redeposition of U around the ablation pits. Although not all the U is reacted with Freon, formation of volatile UF compounds improves the transmission efficiency of U. Typical precision of the 206Pb/238U ratio measurement is 3-5% (2sigma) for NIST SRM 610 and Nancy 91500 zircon standard, and the U-Pb age data obtained here show good agreement within analytical uncertainties with the previously reported values. Since the observed Pb/U ratio for solid samples is relatively insensitive to laser power and ablation time, optimization of ablation conditions or acquisition parameters no longer needs to be performed on a sample-to-sample basis.

Microhardness of demineralized enamel following home bleaching and laser-assisted in office bleaching

Science.gov (United States)

Ghanbarzadeh, Majid; Akbari, Majid; Hamzei, Haniye

2015-01-01

Background There is little data regarding the effect of tooth whitening on microhardness of white spot lesions. This study was conducted to investigate the effect of home-bleaching and laser-assisted in-office bleaching on microhardness of demineralized enamel. Material and Methods Forty bovine incisors were selected and immersed in a demineralizing solution for 12 weeks to induce white spot lesions. Enamel blocks were prepared and randomly assigned to two groups of 20 each. The first group underwent home bleaching with 15% carbamide peroxide which was applied for 8 hours a day over a period of 15 days. In the second group, in-office bleaching was performed by 40% hydrogen peroxide and powered by irradiation from an 810 nm gallium-aluminum-arsenide (GaAlAs) diode laser (CW, 2W). This process was performed for 3 sessions every seven days, in 15 days. The specimens were stored in Fusayama Meyer artificial saliva during the experiment. Surface microhardness was assessed before and after the bleaching therapies in both groups. Results Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (pTooth whitening through home bleaching or laser-assisted in-office bleaching can result in a significant reduction in microhardness of white spot lesions. Therefore, it is suggested to take protective measures on bleached demineralized enamel. Key words:White spot lesion, bleaching, laser, microhardness, demineralized enamel, home bleaching, in-office bleaching. PMID:26330939

Thermally assisted nanosecond laser generation of ferric nanoparticles

Science.gov (United States)

Kurselis, K.; Kozheshkurt, V.; Kiyan, R.; Chichkov, B.; Sajti, L.

2018-03-01

A technique to increase nanosecond laser based production of ferric nanoparticles by elevating temperature of the iron target and controlling its surface exposure to oxygen is reported. High power near-infrared laser ablation of the iron target heated up to 600 °C enhances the particle generation efficiency by more than tenfold exceeding 6 μg/J. Temporal and thermal dependencies of the particle generation process indicate correlation of this enhancement with the oxidative processes that take place on the iron surface during the per spot interpulse delay. Nanoparticles, produced using the heat-assisted ablation technique, are examined using scanning electron and transmission electron microscopy confirming the presence of 1-100 nm nanoparticles with an exponential size distribution that contain multiple randomly oriented magnetite nanocrystallites. The described process enables the application of high power lasers and facilitates precise, uniform, and controllable direct deposition of ferric nanoparticle coatings at the industry-relevant rates.

Femtosecond laser-assisted compared with standard cataract surgery for removal of advanced cataracts.

Science.gov (United States)

Hatch, Kathryn M; Schultz, Tim; Talamo, Jonathan H; Dick, H Burkhard

2015-09-01

To compare effective phacoemulsification time (EPT) for the removal of brunescent cataracts treated with femtosecond laser-assisted cataract surgery with standard cataract phacoemulsification techniques. Ruhr University Eye Hospital, Bochum, Germany. Comparative prospective case study. The Lens Opacities Classification System III (LOCS III) grading system was used to measure eyes divided into 4 groups having cataract surgery. Groups 1 and 2 contained eyes with LOCS III grade nuclear opalescence (NO) 3 cataracts treated with standard cataract surgery and femtosecond laser-assisted cataract surgery, respectively. Groups 3 and 4 contained brunescent cataracts, LOCS III grades NO5, treated with standard cataract surgery and femtosecond laser-assisted cataract surgery, respectively. There were 240 eyes, with 60 eyes in each group. The EPT in Group 1 ranged from 0.46 to 3.10 (mean 1.38); the EPT in all eyes in Group 2 was 0 (P Talamo, and Dick are consultants to Abbott Medical Optics, Inc. Dr. Schultz has no financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Technical basis for the performance of radiological surveys in support of nuclear facility decommissioning/deactivation utilizing the Laser-Assisted Ranging and Data System (LARADS)

International Nuclear Information System (INIS)

Wade, C.D.

1997-06-01

This document describes the implementation of the Laser-Assisted Ranging and Data System (LARADS) as it applies to performing radiological surveys on facility exterior and interior surfaces. The LARADS enables the system operator to document scanning measurements, stationary radiological measurements, and sample locations of surfaces, with the radiological readings and exact coordinates (<2 cm [0.8 in.] precision) automatically logged in real-time. After the survey is completed, the information is downloaded to a geographical information system, and the radiological information is overlaid on a digital picture of the survey area or may be generated as a computer- aided drafted drawing. The final product is a track map or contour of the survey area that clearly shows the area covered by the detector and the locations of elevated readings. The exact reproducibility of data facilitates locating hot spots for remediation and provides for objective review by regulators and verifiers

Prefabricated neck expanded skin flap with the superficial temporal vessels for facial resurfacing.

Science.gov (United States)

Lazzeri, Davide; Su, Weijie; Qian, Yunliang; Messmer, Caroline; Agostini, Tommaso; Spinelli, Giuseppe; Marcus, Jeffrey R; Levin, L Scott; Zenn, Micheal R; Zhang, Yi Xin

2013-05-01

The achievement of a normal-appearing face after surgical resurfacing remains an elusive goal. This is due in part to insufficient color matching, restoration of contours, and the persistence of visible scars. Flap prefabrication is a staged procedure that provides an independent axial blood supply to local expanded tissues. We describe a new reconstructive alternative with superior reconstructive surgical options for facial resurfacing that better matches damaged or discarded facial tissues. A superficial temporal fascial flap was harvested as the vascular supply of the prefabricated neck flap and located in a subcutaneous neck pocket over a tissue expander. After a 5-month period for expansion and maturation, the prefabricated skin flap was raised, islanded, and rotated to resurface the facial defect. Four patients with hemifacial postburn contracture and two patients affected by hemifacial vascular malformations aged 17 to 42 years (mean 29 years) were successfully treated with no major complication after a mean period of 15 months. Prefabricated neck-expanded skin flap demonstrated an excellent color and texture match with facial skin that surrounded the repair sites, and optimal aesthetic results were obtained. Importantly, facial expression was completely maintained due to thinness and pliability of the rotated skin. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Growth of thin fullerene films by matrix assisted pulsed laser evaporation

DEFF Research Database (Denmark)

Canulescu, Stela; Schou, Jørgen; Fæster, Søren

C60 fullerene thin films of average thickness of more than 100 nm on silicon substrates can be produced in vacuum by matrix-assisted pulsed laser evaporation (MAPLE). A 355 nm Nd:YAG laser was directed onto a frozen target of anisole with a concentration of 0.67 wt% C60. At laser fluences below 1.......5 J/cm2 the dominant fraction of the film molecules are C60 transferred to the substrate without any fragmentation. For high fluences high-resolution SEM images of MAPLE deposited films reveal large circular features on the surface with high amount of material concentrated at edges. These features......, observed over a wide range of laser fluences, are caused by ejection of large matrix-fullerene liquid droplets into the gas-phase and subsequent deposition. At similar laser energies, but using an unfocused laser beam, MAPLE favours evaporation of matrix and organic molecules, resulting in films...

Time-resolved study of absorbing film assisted laser induced forward transfer of Trichoderma longibrachiatum conidia

Energy Technology Data Exchange (ETDEWEB)

Hopp, B [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Smausz, T [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Barna, N [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Vass, Cs [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Antal, Zs [Hungarian Academy of Sciences and University of Szeged, Microbiological Research Group, PO Box 533, H-6701 Szeged (Hungary); Kredics, L [Hungarian Academy of Sciences and University of Szeged, Microbiological Research Group, PO Box 533, H-6701 Szeged (Hungary); Chrisey, D [Naval Research Laboratory, Washington, DC 20375 (United States)

2005-03-21

We have characterized the absorbing film assisted transfer of Trichoderma longibrachiatum conidia using a synchronized laser for illumination. The transfer laser used was a KrF excimer laser ({lambda} = 248 nm, FWHM = 30 ns) and the ejected material was illuminated parallel to the quartz plate by a nitrogen laser pumped Coumarine 153 dye laser beam ({lambda} = 453 nm, FWHM 1 ns) electronically delayed relative to the transfer UV pulse. Our time-resolved investigations determined that the ejection velocity front of the conidia plume from the donor surface during the transfer procedure was 1150 m s{sup -1} at 355 mJ cm{sup -2} applied laser fluence. On the basis of the measured data, the acceleration of the emitted conidia at the plume front was approximately 10{sup 9} x g. The conidia survived the absorbing film assisted forward transfer and associated mechanical shear without significant damages suggesting that the technique might be applicable to other more fragile types of biological objects and applications.

Time-resolved study of absorbing film assisted laser induced forward transfer of Trichoderma longibrachiatum conidia

International Nuclear Information System (INIS)

Hopp, B; Smausz, T; Barna, N; Vass, Cs; Antal, Zs; Kredics, L; Chrisey, D

2005-01-01

We have characterized the absorbing film assisted transfer of Trichoderma longibrachiatum conidia using a synchronized laser for illumination. The transfer laser used was a KrF excimer laser (λ = 248 nm, FWHM = 30 ns) and the ejected material was illuminated parallel to the quartz plate by a nitrogen laser pumped Coumarine 153 dye laser beam (λ = 453 nm, FWHM 1 ns) electronically delayed relative to the transfer UV pulse. Our time-resolved investigations determined that the ejection velocity front of the conidia plume from the donor surface during the transfer procedure was 1150 m s -1 at 355 mJ cm -2 applied laser fluence. On the basis of the measured data, the acceleration of the emitted conidia at the plume front was approximately 10 9 x g. The conidia survived the absorbing film assisted forward transfer and associated mechanical shear without significant damages suggesting that the technique might be applicable to other more fragile types of biological objects and applications

Endobronchial Forceps-Assisted and Excimer Laser-Assisted Inferior Vena Cava Filter Removal: The Data, Where We Are, and How It Is Done.

Science.gov (United States)

Chen, James X; Montgomery, Jennifer; McLennan, Gordon; Stavropoulos, S William

2018-06-01

The recognition of inferior vena cava filter related complications has motivated increased attentiveness in clinical follow-up of patients with inferior vena cava filters and has led to development of multiple approaches for retrieving filters that are challenging or impossible to remove using conventional techniques. Endobronchial forceps and excimer lasers are tools for designed to aid in complex inferior vena cava filter removals. This article discusses endobronchial forceps-assisted and excimer laser-assisted inferior vena cava filter retrievals. Copyright © 2018 Elsevier Inc. All rights reserved.

Body contour measurements by conoscopy: application in nuclear medicine, study of feasibility

International Nuclear Information System (INIS)

Scheiber, C.; Musse, O.; Mallet, Y.; Sirat, G.

1997-01-01

The aim of this study was to obtain a precise mapping of the human body contours as viewed by the gamma camera during acquisition for pathological focus detection and as intermediary in the fusion with morphological images sources (CT, IRM, US). The measurement of the human body contours, making use of a telemeter system, was proposed by O. Peria (Ph.D Thesis, University of Grenoble) by using a laser telemeter and then structured-light sources. We proposed utilization of a non-coherent interferometer, the conoscope developed by G. Sirat, coupled to an electro-mechanical sweeping system mounted on the gamma camera rack. The first tests realized with a slow prototype (3 pt/s), have allowed the recording of visage contours (a profile obtained by angular rotation of the camera (10 deg.) on an (Elscint, Haifa) Helix gamma camera). For this experiment the voluntary subject has worn protection spectacles (the light source being a laser of 1 mW). Among the advantages of this compact system (14 x 10 x 15 cm) we stress: a) a high precision (0.2 mm); b) being installed on the rack, the calibration procedures are simplified and their shifts are potentially reduced; c) the procedures of intra-modality image matching is simplified; d) an integrated fast electronic circuitry (DSP) allows to exploit directly, in real time if necessary, the obtained results (x,y,z coordinates of the studied point). We considered that by its precision, its insensitivity to luminous environment conditions and its integration with the turning gamma camera, the system deserves to be evaluated for application in medical imaging. This system as other intermediate captors, using body contours, allows the superimposing of data, other than the image data, what helps the stereotaxic localization

Fairfax County Contours

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — This layer contains contours that were derived from the digital terrain model made up of irregularly spaced mass points and breaklines. The contours are 5 foot...

Laser assisted soldering: microdroplet accumulation with a microjet device.

Science.gov (United States)

Chan, E K; Lu, Q; Bell, B; Motamedi, M; Frederickson, C; Brown, D T; Kovach, I S; Welch, A J

1998-01-01

We investigated the feasibility of a microjet to dispense protein solder for laser assisted soldering. Successive micro solder droplets were deposited on rat dermis and bovine intima specimens. Fixed laser exposure was synchronized with the jetting of each droplet. After photocoagulation, each specimen was cut into two halves at the center of solder coagulum. One half was fixed immediately, while the other half was soaked in phosphate-buffered saline for a designated hydration period before fixation (1 hour, 1, 2, and 7 days). After each hydration period, all tissue specimens were prepared for scanning electron microscopy (SEM). Stable solder coagulum was created by successive photocoagulation of microdroplets even after the soldered tissue exposed to 1 week of hydration. This preliminary study suggested that tissue soldering with successive microdroplets is feasible even with fixed laser parameters without active feedback control.

Cell patterning by laser-assisted bioprinting.

Science.gov (United States)

Devillard, Raphaël; Pagès, Emeline; Correa, Manuela Medina; Kériquel, Virginie; Rémy, Murielle; Kalisky, Jérôme; Ali, Muhammad; Guillotin, Bertrand; Guillemot, Fabien

2014-01-01

The aim of tissue engineering is to produce functional three-dimensional (3D) tissue substitutes. Regarding native organ and tissue complexity, cell density and cell spatial 3D organization, which influence cell behavior and fate, are key parameters in tissue engineering. Laser-Assisted Bioprinting (LAB) allows one to print cells and liquid materials with a cell- or picoliter-level resolution. Thus, LAB seems to be an emerging and promising technology to fabricate tissue-like structures that have the physiological functionality of their native counterparts. This technology has additional advantages such as automation, reproducibility, and high throughput. It makes LAB compatible with the (industrial) fabrication of 3D constructs of physiologically relevant sizes. Here we present exhaustively the numerous steps that allow printing of viable cells with a well-preserved micrometer pattern. To facilitate the understanding of the whole cell patterning experiment using LAB, it is discussed in two parts: (1) preprocessing: laser set-up, bio-ink cartridge and bio-paper preparation, and pattern design; and (2) processing: bio-ink printing on the bio-paper. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of laser energy and wavelength on the analysis of LiFePO4 using laser assisted atom probe tomography

International Nuclear Information System (INIS)

Santhanagopalan, Dhamodaran; Schreiber, Daniel K.; Perea, Daniel E.; Martens, Richard L.; Janssen, Yuri; Khalifah, Peter; Meng, Ying Shirley

2015-01-01

The effects of laser wavelength (355 nm and 532 nm) and laser pulse energy on the quantitative analysis of LiFePO 4 by atom probe tomography are considered. A systematic investigation of ultraviolet (UV, 355 nm) and green (532 nm) laser assisted field evaporation has revealed distinctly different behaviors. With the use of a UV laser, the major issue was identified as the preferential loss of oxygen (up to 10 at%) while other elements (Li, Fe and P) were observed to be close to nominal ratios. Lowering the laser energy per pulse to 1 pJ/pulse from 50 pJ/pulse increased the observed oxygen concentration to nearer its correct stoichiometry, which was also well correlated with systematically higher concentrations of 16 O 2 + ions. Green laser assisted field evaporation led to the selective loss of Li (∼33% deficiency) and a relatively minor O deficiency. The loss of Li is likely a result of selective dc evaporation of Li between or after laser pulses. Comparison of the UV and green laser data suggests that the green wavelength energy was absorbed less efficiently than the UV wavelength because of differences in absorption at 355 and 532 nm for LiFePO 4 . Plotting of multihit events on Saxey plots also revealed a strong neutral O 2 loss from molecular dissociation, but quantification of this loss was insufficient to account for the observed oxygen deficiency. - Highlights: • Laser wavelength and pulse energy affect accuracy of APT analysis of LiFePO 4 . • Oxygen deficiency observed for UV laser; stronger at higher laser energies. • Selective loss of Li with green laser due to dc evaporation. • Saxey plots reveal prevalent formation of O 2 neutrals. • Quantification of molecular dissociations cannot account for O deficiency

Dispensing pico to nanolitre of a natural hydrogel by laser-assisted bioprinting

Directory of Open Access Journals (Sweden)

Deiwick Andrea

2011-03-01

Full Text Available Abstract Background Laser-assisted bioprinting of multi-cellular replicates in accordance with CAD blueprint may substantially improve our understandings of fundamental aspects of 3 D cell-cell and cell-matrix interactions in vitro. For predictable printing results, a profound knowledge about effects of different processing parameters is essential for realisation of 3 D cell models with well-defined cell densities. Methods Time-resolved imaging of the hydrogel jet dynamics and quantitative assessment of the dependence of printed droplet diameter on the process characteristics were conducted. Results The existence of a counterjet was visualised, proving the bubble collapsing theory for the jet formation. Furthermore, by adjusting the viscosity and height of the applied hydrogel layer in combination with different laser pulse energies, the printing of volumes in the range of 10 to 7000 picolitres was demonstrated. Additionally, the relationship between the viscosity and the layer thickness at different laser pulse energies on the printed droplet volume was identified. Conclusions These findings are essential for the advancement of laser-assisted bioprinting by enabling predictable printing results and the integration of computational methods in the generation of 3 D multi-cellular constructs.

Clinical assessment of diode laser-assisted endoscopic intrasphenoidal vidian neurectomy in the treatment of refractory rhinitis.

Science.gov (United States)

Lai, Wen-Sen; Cheng, Sheng-Yao; Lin, Yuan-Yung; Yang, Pei-Lin; Lin, Hung-Che; Cheng, Li-Hsiang; Yang, Jinn-Moon; Lee, Jih-Chin

2017-12-01

For chronic rhinitis that is refractory to medical therapy, surgical intervention such as endoscopic vidian neurectomy (VN) can be used to control the intractable symptoms. Lasers can contribute to minimizing the invasiveness of ENT surgery. The aim of this retrospective study is to compare in patients who underwent diode laser-assisted versus traditional VN in terms of operative time, surgical field, quality of life, and postoperative complications. All patients had refractory rhinitis with a poor treatment response to a 6-month trial of corticosteroid nasal sprays and underwent endoscopic VN between November 2006 and September 2015. They were non-randomly allocated into either a cold instrument group or a diode laser-assisted group. Vidian nerve was excised with a 940-nm continuous wave diode laser through a 600-μm silica optical fiber, utilizing a contact mode with the power set at 5 W. A visual analog scale (VAS) was used to grade the severity of the rhinitis symptoms for quality of life assessment before the surgery and 6 months after. Of the 118 patients enrolled in the study, 75 patients underwent cold instrument VN and 43 patients underwent diode laser-assisted VN. Patients in the laser-assisted group had a significantly lower surgical field score and a lower postoperative bleeding rate than those in the cold instrument group. Changes in the VAS were significant in preoperative and postoperative nasal symptoms in each group. The application of diode lasers for vidian nerve transection showed a better surgical field and a lower incidence of postoperative hemorrhage. Recent advancements in laser application and endoscopic technique has made VN safer and more effective. We recommend this surgical approach as a reliable and effective treatment for patients with refractory rhinitis.

Matrix Assisted Pulsed Laser Evaporation for growth of fullerene thin films

DEFF Research Database (Denmark)

Canulescu, Stela; Schou, Jørgen; Fæster Nielsen, Søren

C60 fullerene thin films of average thickness of more than 100 nm can be produced in vacuum by matrix-assisted pulsed laser evaporation (MAPLE). A 355 nm Nd:YAG laser was directed onto a frozen target of anisole with a concentration of 0.67 wt% C60. At laser fluences below 1.5 J/cm2, a dominant...... fraction of the film molecules are C60 transferred to the substrate without any fragmentation. Highresolution SEM images of MAPLE deposited films reveal large circular droplets on the surface with high amount of material concentrated at edges (Fig. 1A). These features, observed over a wide range of laser...... fluences, are caused by ejection of large matrix-fullerene liquid droplets into the gas-phase and subsequent deposition. At similar laser energies, but using an unfocused laser beam, MAPLE favours evaporation of matrix and organic molecules, resulting in production of films with smooth surfaces and minimal...

[Advantages and disadvantages of femtosecond laser assisted LASIK and SMILE].

Science.gov (United States)

Zhang, F J; Sun, M S

2018-01-11

With the development of excimer laser and femtosecond laser equipment, application of diversified and customized surgical decision in modern corneal refractive surgery has been an inevitable trend. However, how to make a personalized decision with an accurate surgical design to achieve better visual quality becomes the main focus in clinical applications. Small-incision lenticule extraction (SMILE) and femtosecond assisted laser in situ keratomileusis (FS-LASIK) have been commonly acknowledged as the mainstream of corneal refractive surgery for ametropia correction nowadays. Both methods have been verified by clinical practice for many years. This article compares and elaborates the different characteristics with advantages and disadvantages of the two methods so as to provide some reasonable treatment options for refractive surgery. (Chin J Ophthalmol, 2018, 54: 7-10) .

Multisample matrix-assisted laser desorption source for molecular beams of neutral peptides

International Nuclear Information System (INIS)

Lupulescu, C.; Abd El Rahim, M.; Antoine, R.; Barbaire, M.; Broyer, M.; Dagany, X.; Maurelli, J.; Rayane, D.; Dugourd, Ph.

2006-01-01

We developed and tested a multisample laser desorption source for producing stable molecular beams of neutral peptides. Our apparatus is based on matrix-assisted laser desorption technique. The source consists of 96 different targets which may be scanned by a software control procedure. Examples of molecular beams of neutral peptides are presented, as well as the influence of the different source parameters on the jet

Surface plasmon resonance assisted rapid laser joining of glass

Energy Technology Data Exchange (ETDEWEB)

Zolotovskaya, Svetlana A.; Tang, Guang; Abdolvand, Amin, E-mail: a.abdolvand@dundee.ac.uk [School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); Wang, Zengbo [School of Electronic Engineering, Bangor University, Bangor LL57 1UT (United Kingdom)

2014-08-25

Rapid and strong joining of clear glass to glass containing randomly distributed embedded spherical silver nanoparticles upon nanosecond pulsed laser irradiation (∼40 ns and repetition rate of 100 kHz) at 532 nm is demonstrated. The embedded silver nanoparticles were ∼30–40 nm in diameter, contained in a thin surface layer of ∼10 μm. A joint strength of 12.5 MPa was achieved for a laser fluence of only ∼0.13 J/cm{sup 2} and scanning speed of 10 mm/s. The bonding mechanism is discussed in terms of absorption of the laser energy by nanoparticles and the transfer of the accumulated localised heat to the surrounding glass leading to the local melting and formation of a strong bond. The presented technique is scalable and overcomes a number of serious challenges for a widespread adoption of laser-assisted rapid joining of glass substrates, enabling applications in the manufacture of microelectronic devices, sensors, micro-fluidic, and medical devices.

Facial biometrics of peri-oral changes in Crohn's disease.

Science.gov (United States)

Zou, L; Adegun, O K; Willis, A; Fortune, Farida

2014-05-01

Crohn's disease is a chronic relapsing and remitting inflammatory condition which affects any part of the gastrointestinal tract. In the oro-facial region, patients can present peri-oral swellings which results in severe facial disfigurement. To date, assessing the degree of facial changes and evaluation of treatment outcomes relies on clinical observation and semi-quantitative methods. In this paper, we describe the development of a robust and reproducible measurement strategy using 3-D facial biometrics to objectively quantify the extent and progression of oro-facial Crohn's disease. Using facial laser scanning, 32 serial images from 13 Crohn's patients attending the Oral Medicine clinic were acquired during relapse, remission, and post-treatment phases. Utilising theories of coordinate metrology, the facial images were subjected to registration, regions of interest identification, and reproducible repositioning prior to obtaining volume measurements. To quantify the changes in tissue volume, scan images from consecutive appointments were compared to the baseline (first scan image). Reproducibility test was performed to ascertain the degree of uncertainty in volume measurements. 3-D facial biometric imaging is a reliable method to identify and quantify peri-oral swelling in Crohn's patients. Comparison of facial scan images at different phases of the disease revealed precisely profile and volume changes. The volume measurements were highly reproducible as adjudged from the 1% standard deviation. 3-D facial biometrics measurements in Crohn's patients with oro-facial involvement offers a quick, robust, economical and objective approach for guided therapeutic intervention and routine assessment of treatment efficacy on the clinic.

Ethnic differences in the structural properties of facial skin.

Science.gov (United States)

Sugiyama-Nakagiri, Yoriko; Sugata, Keiichi; Hachiya, Akira; Osanai, Osamu; Ohuchi, Atsushi; Kitahara, Takashi

2009-02-01

Conspicuous facial pores are one type of serious aesthetic defects for many women. However, the mechanism(s) that underlie the conspicuousness of facial pores remains unclear. We previously characterized the epidermal architecture around facial pores that correlated with the appearance of those pores. A survey was carried out to elucidate ethnic-dependent differences in facial pore size and in epidermal architecture. The subjects included 80 healthy women (aged 30-39: Caucasians, Asians, Hispanics and African Americans) living in Dallas in the USA. First, surface replicas were collected to compare pore sizes of cheek skin. Second, horizontal cross-sectioned images from cheek skin were obtained non-invasively from the same subjects using in vivo confocal laser scanning microscopy (CLSM) and the severity of impairment of epidermal architecture around facial pores was determined. Finally, to compare racial differences in the architecture of the interfollicular epidermis of facial cheek skin, horizontal cross-sectioned images were obtained and the numbers of dermal papillae were counted. Asians had the smallest pore areas compared with other racial groups. Regarding the epidermal architecture around facial pores, all ethnic groups observed in this study had similar morphological features and African Americans showed substantially more severe impairment of architecture around facial pores than any other racial group. In addition, significant differences were observed in the architecture of the interfollicular epidermis between ethnic groups. These results suggest that facial pore size, the epidermal architecture around facial pores and the architecture of the interfollicular epidermis differ between ethnic groups. This might affect the appearance of facial pores.

Facial soft tissue thickness database of Gujarati population for forensic craniofacial reconstruction

Directory of Open Access Journals (Sweden)

Anand Lodha

2016-06-01

Full Text Available The forensic facial reconstruction is a scientific art to construct the ante-mortem face from the human skull. The facial recognition is made by reconstructing the contours of the facial soft tissue thickness (FSTT.These FSTT data are essential for probable face reconstruction but the data of FSTT at particular anthropological landmarks differ in various ethnic groups. Until now several works have been reported on different population but no study exists in which the FSTT of a Gujarati population has been measured. The aim of this study is to compile a set of soft tissue depth data of Gujarati population of India to add to existing literature on FSTT. Computed tomography (CT-scan has been utilized to measure the 25 different FSTT landmarks of 324 male and 165 female. Present study shows significant differences in certain FSTT of Gujarati population from that of other populations. Our compiled data set of FSTT for the Gujarati population is important in understanding craniofacial characteristics of the Gujarati population and potentially be helpful in forensic identification.

Processing of C60 thin films by Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

DEFF Research Database (Denmark)

Canulescu, Stela; Schou, Jørgen; Fæster, Søren

2011-01-01

Thin films of fullerenes (C60) were deposited onto silicon using matrix-assisted pulsed laser evaporation (MAPLE). The deposition was carried out from a frozen homogeneous dilute solution of C60 in anisole (0.67 wt%), and over a broad range of laser fluences, from 0.15 J/cm2 up to 3.9 J/cm2. MAPLE...

CONTOUR investigation launched

Science.gov (United States)

Showstack, Randy

On 27 August, NASA Administrator Sean O'Keefe appointed a team to investigate the apparent loss of the Comet Nucleus Tour (CONTOUR) spacecraft, which stopped communicating with the mission control operations on 15 August.On that date, CONTOUR failed to communicate following the firing of its main engine that would take it out of its orbit around the Earth. Shortly afterwards, the mission team received telescope images from several observatories showing two objects traveling along the spacecraft's predicted path. Those objects could be CONTOUR, and part of the spacecraft that may have separated from it when the spacecraft's solid rocket motor fired.

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

(Con)fusing contours

NARCIS (Netherlands)

Lier, R.J. van; Wit, T.C.J. de; Koning, A.R.

2005-01-01

We have created patterns in which illusory Kanizsa squares are positioned on top of a background grid of bars. When the illusory contours and physical contours are misaligned, the resulting percept appears to be rather confusing (van Lier et al, 2004 Perception 33 Supplement, 77). Observers often

Production of active lysozyme films by matrix assisted pulsed laser evaporation at 355 nm

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Kingshott, P.

2007-01-01

Thin lysozyme films have been produced in a dry environment by MAPLE (matrix assisted pulsed laser evaporation) from a water ice matrix irradiated by laser light at 355 nm above the absorption threshold of the protein. A significant part of the lysozyme molecules are transferred to the film without...

Theory of the photoelectric effect assisted by an elliptically polarized laser field

International Nuclear Information System (INIS)

Li Shumin; Jentschura, Ulrich D

2009-01-01

The laser-assisted photoelectric effect in atomic hydrogen is investigated for linear, circular and general elliptic polarizations. The perturbative dressed state of the atom in an elliptically polarized nonresonant laser field is derived in the velocity gauge. The continuum state of the ejected electron is described by a Coulomb-Volkov wavefunction. Numerical results show that the ionization cross section by a vacuum ultraviolet photon is enhanced at high laser field intensities and low frequencies. At small and extremely large scattering angles (measured with respect to the wave vector of the incoming vacuum ultraviolet photon), the process for emitting a laser photon is predominant, while at medium angles, the result favours the process without a laser photon exchange. The dependence of the results on the laser polarization and on various geometries is studied, and an interesting pattern is found for the dependence on the frequency of the dressing laser; an intuitive explanation is offered.

Study of the mechanisms of matrix assisted laser desorption / ionization

International Nuclear Information System (INIS)

Manuelli, Pascal

1995-01-01

This research thesis aims at a better knowledge of some aspects of a complex mechanism: the matrix-assisted laser desorption/ionization (MALDI). The author first proposes a comparative analysis of results obtained by time-of-flight (TOF) mass spectrometry and by Fourier transform mass spectrometry. He reports the study of the matrix role (notably a polymeric matrix) as a matter submitted to laser desorption. In this respect, the influence of the incident wavelength has been studied. The author also reports a comparative of ions produced by matrix laser desorption (study performed by Fourier transform mass spectrometry) and of neutral molecules (study performed by flash pyrolysis coupled with gas chromatography and with mass spectrometry). Finally, results obtained on derivatives and complexes based on beta-cyclodextrins highlight benefits as well as limitations of this technique [fr

Split-face comparison of radiofrequency versus long-pulse Nd-YAG treatment of facial laxity.

Science.gov (United States)

Taylor, Mark B; Prokopenko, Inna

2006-04-01

To improve photoaging skin with laser treatment, multiple sessions have been considered necessary to achieve results comparable with one radiofrequency (RF) treatment. We compared single-treatment improvements obtained by the long-pulse 1064 nm Nd:YAG laser and RF device. In a split-face study, patients with sagging skin were treated once with laser (left side) and once with RF (right side) energy. Improvement judged by six blinded observers was greater for wrinkles and laxity (30% median) on the laser-treated side and essentially the same with both modalities (15% median) for texture, pores, and pigmentation. Improvement was maintained for at least 2-6 months on both facial sides without adverse effects. With a single treatment, both the long-pulse 1064 nm Nd:YAG laser and ThermaCool RF device provide a modest degree of improvement in both wrinkles and laxity of facial skin and similar improvement in texture, pores, and pigmentation.

Laser-assisted electron scattering in strong-field ionization of dense water vapor by ultrashort laser pulses

International Nuclear Information System (INIS)

Wilke, M; Al-Obaidi, R; Moguilevski, A; Kothe, A; Engel, N; Metje, J; Kiyan, I Yu; Aziz, E F

2014-01-01

We report on strong-field ionization of dense water gas in a short infrared laser pulse. By employing a unique combination of photoelectron spectroscopy with a liquid micro-jet technique, we observe how the character of electron emission at high kinetic energies changes with the increase of the medium density. This change is associated with the process of laser-assisted electron scattering (LAES) on neighboring particles, which becomes a dominant mechanism of hot electron emission at higher medium densities. The manifestation of this mechanism is found to require densities that are orders of magnitude lower than those considered for heating the laser-generated plasmas via the LAES process. The experimental results are supported by simulations of the LAES yield with the use of the Kroll–Watson theory. (paper)

Preliminary observation of refractive cataract surgery assisted by femtosecond laser

Directory of Open Access Journals (Sweden)

Xiao-Li Wang

2015-12-01

Full Text Available AIM:To compare the differences of visual acuity and corneal astigmatism postoperatively between conventional refractive cataract surgery and that assisted by femtosecond laser.METHODS:Sixty patients(60 eyeswith age-related cataract and cornea astigmatism were divided into femtosecond group and conventional group randomly or voluntarily. The flat shaft, steep shaft and diopter of corneal astigmatism in patients in femtosecond group were inputted into the online vector calculators to get the location and width of the incision. Then femtosecond laser was used to make corneal releasing incision, the main and auxiliary incision. Phacoemulsification and aspheric multifocal intraocular lens implantation were undergone. Patients in conventional group received full-thickness relaxing incision by cornea paracentesis knife at the steepest meridian axis during phacoemulsification. Then aspheric multifocal intraocular lenses were implanted. Uncorrected distance visual acuity(UCDVA, uncorrected near visual acuity(UCNVAand cornea astigmatism were observed at 1d,1wk and 1mo postoperative. RESULTS:UCVA of patients in both groups was improved after the surgeries. UCDVA and UCNVA of femtosecond group were higher than those of conventional group, while the cornea astigmatism of femtosecond group was lower than that of conventional group.CONCLUSION:Refractile cataract surgery assisted by femtosecond laser canoffer better visual quality than conventional refractive cataract surgery because of lower cornea astigmatism and better visual acuity.

Thermal and thermo-mechanical simulation of laser assisted machining

International Nuclear Information System (INIS)

Germain, G.; Dal Santo, P.; Lebrun, J. L.; Bellett, D.; Robert, P.

2007-01-01

Laser Assisted Machining (LAM) improves the machinability of materials by locally heating the workpiece just prior to cutting. The heat input is provided by a high power laser focused several millimeters in front of the cutting tool. Experimental investigations have confirmed that the cutting force can be decreased, by as much as 40%, for various materials (tool steel, titanium alloys and nickel alloys). The laser heat input is essentially superficial and results in non-uniform temperature profiles within the depth of the workpiece. The temperature field in the cutting zone is therefore influenced by many parameters. In order to understand the effect of the laser on chip formation and on the temperature fields in the different deformation zones, thermo-mechanical simulation were undertaken. A thermo-mechanical model for chip formation with and without the laser was also undertaken for different cutting parameters. Experimental tests for the orthogonal cutting of 42CrMo4 steel were used to validate the simulation via the prediction of the cutting force with and without the laser. The thermo-mechanical model then allowed us to highlight the differences in the temperature fields in the cutting zone with and without the laser. In particular, it was shown that for LAM the auto-heating of the material in the primary shear zone is less important and that the friction between the tool and chip also generates less heat. The temperature fields allow us to explain the reduction in the cutting force and the resulting residual stress fields in the workpiece

Laser-assisted skin closure at 1.32 microns: the use of a software-driven medical laser system

Science.gov (United States)

Dew, Douglas K.; Hsu, Tung M.; Hsu, Long S.; Halpern, Steven J.; Michaels, Charles E.

1991-06-01

This study investigated the use of a computerized 1 .3 micron Nd:YAG laser to seal approximated wound edges in pig skin. The medical laser system used was the DLS Type 1 , 1 .32 micron Nd:YAG laser (Laser Surgery Software, Inc.). The purpose of this study was to evaluate the effectiveness of laser assisted skin closure using the DLS YAG laser in a large animal model. Effectiveness was judged on the basis of wound dehiscence, infection, unusual healing result and consistency of results. Comparative cosmetic result was also evaluated. In this study, the DLS YAG laser was used to close scalpel-induced, full-thickness wounds. The pig model was chosen for its many integumentary similarities to man. Controls included scalpel-induced wounds closed using suture, staple and some with norepair. After adequate anesthesia was achieved, the dorsum of Yucutan pigs (approximately 75- 100 pounds) each was clipped with animal hair clippers from the shoulder area to the hind legs. The area was then shaved with a razor blade, avoiding any inadvertent cuts or abrasions of the skin. The dorsum was divided into four rows of four parallel incisions made by a #15 scalpel blade. Full-thickness incisions, 9 cm long, were placed over the dorsum of the pigs and then closed either with one loosely approximating Prolene" suture (the "no repair' group), multiple interrupted 6-0 nylon sutures, staples or laser. The experimental tissue sealing group consisted of 1 69 laser assisted closures on 1 3 pigs. Sutured control wounds were closed with 6-0 nylon, full thickness, simple, interrupted sutures. Eight sutures were placed 1 cm apart along the 9 cm incision. Stapled control wounds were approximated using two evenly spaced 3-0 VicryP' sub-dermal sutures and the dermis closed using Proximate' skin staples. Eight staples were placed 1 cm apart along the 9 cm incision. The no-repair incisions were grossly approximated using a single 2-0 Prolene full thickness, simple, interrupted suture located at the

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...

Laser-assisted modification of polystyrene surfaces for cell culture applications

International Nuclear Information System (INIS)

Pfleging, Wilhelm; Bruns, Michael; Welle, Alexander; Wilson, Sandra

2007-01-01

Laser-assisted patterning and modification of polystyrene (PS) was investigated with respect to applications in micro-fluidics and cell culture. For this purpose the wettability, the adsorption of proteins and the adhesion of animal cells were investigated as function of laser- and processing parameters. The change of surface chemistry was characterized by X-ray photoelectron spectroscopy. The local formation of chemical structures suitable for improved cell adhesion was realized on PS surfaces by UV laser irradiation. Above and below the laser ablation threshold two different mechanisms affecting cell adhesion were detected. In the first case the debris deposited on and along laser irradiated areas was responsible for improved cell adhesion, while in the second case a photolytic activation of the polymer surface including a subsequent oxidization in oxygen or ambient air is leading to a highly localized alteration of protein adsorption from cell culture media and finally to increased cell adhesion. Laser modifications of PS using suitable exposure doses and an appropriate choice of the processing gas (helium or oxygen) enabled a highly localized control of wetting. The dynamic advancing contact angle could be adjusted between 2 o and 150 o . The hydrophilic and hydrophobic behaviour are caused by chemical and topographical surface changes

Restoring jawline contour with calcium hydroxylapatite: A prospective, observational study.

Science.gov (United States)

Baspeyras, Martine; Dallara, Jean-Marie; Cartier, Hugues; Charavel, Marie-Hélène; Dumas, Laurent

2017-09-01

Jawline reshaping by replacing volume has become an indispensable component of modern facial rejuvenation. To evaluate calcium hydroxylapatite (CaHA) for the treatment of an aging jawline in a routine setting. Five investigators enrolled 35 subjects requesting jawline rejuvenation with CaHA. Injections were performed according to investigators usual practice. Baseline and post-treatment scores were evaluated using Merz Aesthetics Scales®. Follow-up visits took place at Day 30 (Day 60 for those with touch-up at Day 30), 180, and 360. Physician and patient satisfaction, esthetic impact of treatment, and adverse events were recorded. Improvements in jawline contour compared with baseline were statistically significant at each visit, with scores of 2.42 (moderate to severe sagging) at baseline, 1.02 (mild) at Day 30/60 (P≤.0001), 1.11 at Day 180 (P≤.0001), and 1.45 at Day 360 (P=.0015). Statistically significant improvements in marionette line scores were also observed. Investigators rated results as "improved" to "very much improved" in all subjects up to Day 180, and in 81% of subjects at Day 360. Satisfaction with treatment was very high. Adverse events were mostly mild and related to either the procedure or injection technique. CaHA is a very effective agent for restoring jawline contour in routine practice and is associated with high levels of physician and patient satisfaction. © 2017 Wiley Periodicals, Inc.

High Resolution Elevation Contours

Data.gov (United States)

Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

Tagged Vector Contour (TVC)

Data.gov (United States)

Kansas Data Access and Support Center — The Kansas Tagged Vector Contour (TVC) dataset consists of digitized contours from the 7.5 minute topographic quadrangle maps. Coverage for the state is incomplete....

Delineation of facial archetypes by 3d averaging.

Science.gov (United States)

Shaweesh, Ashraf I; Thomas, C David L; Bankier, Agnes; Clement, John G

2004-10-01

The objective of this study was to investigate the feasibility of creating archetypal 3D faces through computerized 3D facial averaging. A 3D surface scanner Fiore and its software were used to acquire the 3D scans of the faces while 3D Rugle3 and locally-developed software generated the holistic facial averages. 3D facial averages were created from two ethnic groups; European and Japanese and from children with three previous genetic disorders; Williams syndrome, achondroplasia and Sotos syndrome as well as the normal control group. The method included averaging the corresponding depth (z) coordinates of the 3D facial scans. Compared with other face averaging techniques there was not any warping or filling in the spaces by interpolation; however, this facial average lacked colour information. The results showed that as few as 14 faces were sufficient to create an archetypal facial average. In turn this would make it practical to use face averaging as an identification tool in cases where it would be difficult to recruit a larger number of participants. In generating the average, correcting for size differences among faces was shown to adjust the average outlines of the facial features. It is assumed that 3D facial averaging would help in the identification of the ethnic status of persons whose identity may not be known with certainty. In clinical medicine, it would have a great potential for the diagnosis of syndromes with distinctive facial features. The system would also assist in the education of clinicians in the recognition and identification of such syndromes.

Amplification of pressure waves in laser-assisted endodontics with synchronized delivery of Er:YAG laser pulses.

Science.gov (United States)

Lukač, Nejc; Jezeršek, Matija

2018-05-01

When attempting to clean surfaces of dental root canals with laser-induced cavitation bubbles, the resulting cavitation oscillations are significantly prolonged due to friction on the cavity walls and other factors. Consequently, the collapses are less intense and the shock waves that are usually emitted following a bubble's collapse are diminished or not present at all. A new technique of synchronized laser-pulse delivery intended to enhance the emission of shock waves from collapsed bubbles in fluid-filled endodontic canals is reported. A laser beam deflection probe, a high-speed camera, and shadow photography were used to characterize the induced photoacoustic phenomena during synchronized delivery of Er:YAG laser pulses in a confined volume of water. A shock wave enhancing technique was employed which consists of delivering a second laser pulse at a delay with regard to the first cavitation bubble-forming laser pulse. Influence of the delay between the first and second laser pulses on the generation of pressure and shock waves during the first bubble's collapse was measured for different laser pulse energies and cavity volumes. Results show that the optimal delay between the two laser pulses is strongly correlated with the cavitation bubble's oscillation period. Under optimal synchronization conditions, the growth of the second cavitation bubble was observed to accelerate the collapse of the first cavitation bubble, leading to a violent collapse, during which shock waves are emitted. Additionally, shock waves created by the accelerated collapse of the primary cavitation bubble and as well of the accompanying smaller secondary bubbles near the cavity walls were observed. The reported phenomena may have applications in improved laser cleaning of surfaces during laser-assisted dental root canal treatments.

Clinical outcome of endonasal KTP laser assisted dacryocystorhinostomy

Directory of Open Access Journals (Sweden)

Carrie Sean

2005-03-01

Full Text Available Abstract Background To evaluate the clinical outcome of primary endonasal laser assisted dacryocystorhinostomy (ENL-DCR using the potassium-titanyl-phosphate laser. Methods We retrospectively reviewed all primary ENL-DCRs performed within a period of twelve months by the same combined Ophthalmology and Otorhinolaringology team in Freeman Hospital, Newcastle upon Tyne, UK. The main outcome measure for success was resolution or significant improvement of epiphora. Details of surgery, intraoperative and postoperative complications, as well as pathology associated with failure were also studied. Patients were followed up for at least 12 months. Results A total of 41 consecutive ENL-DCRs on 29 patients (22 females, 7 males, mean age 75 years were analysed. All patients had bicanalicular silicone intubation for at least 4 months. The success rate at 12 months postoperatively was 78.1%. Pathology associated with failure included: intranasal pathology (12.2%, mucocele (7.3%, and systemic sarcoidosis (2.4%. No significant intra-operative complications were recorded. Conclusion The ENL-DCR with potassium-titanyl-phosphate laser can be considered as a safe and efficient primary procedure for the treatment of nasolacrimal duct obstruction.

Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

Science.gov (United States)

Boll, D. I. R.; Fojón, O. A.

2017-12-01

We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets.

Ocean Sediment Thickness Contours

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

Diode laser-assisted transcanalicular dacryocystorhinostomy: the effect of age on the results

Directory of Open Access Journals (Sweden)

Fahrettin Akay

2015-06-01

Full Text Available ABSTRACT Purpose: The aim of this study was to explore the effect of age on the success of transcanalicular diode laser-assisted dacryocystorhinostomy (TCDCR. Methods: Seventy patients (70 eyes who underwent transcanalicular diode laser-assisted dacryocystorhinostomy for the treatment of nasolacrimal duct obstruction as a primary surgery were included in this retrospective, nonrandomized study. The patients were divided into two groups according to age. Mean ages were 21.3 ± 3.3 in group 1 and 60.3 ± 7.3 in group 2. The records of the 3-, 6-, and 12-month follow-up examinations were evaluated, and the anatomical and functional outcomes were noted. Functional success was defined as the absence of epiphora as indicated by the patient. Anatomical success was determined as patency of the neo-ostium with irrigation. Results: At the 3-month follow-up, 67% cases in group 1 showed anatomical success and 52% showed functional success; in group 2, the rates were 100% and 92%, respectively. Functional and anatomical success rates were the same for both the 6- and 12-month visits; 46% in group 1 and 76% in group 2. The results in group 2 were significantly better at all three follow-up visits (p<0.05. Conclusions: This study clearly showed that the older patients experienced better transcanalicular diode laser-assisted dacryocystorhinostomy results than the younger patients. The diminished inflammatory response in the older population may be a possible contributing factor to these results.

[Laser-assisted lipolysis for gynecomastia: safe and effective skin retraction].

Science.gov (United States)

Trelles, Mario; Bonanad, Enrique; Moreno-Moraga, Javier; Alcolea, Justo; Mordon, Serge; Leclère, Franck Marie

2013-01-01

To evaluate efficacy of laser lipolysis in the treatment of gynecomastia to correct breast volume, flaccidity and excess skin without its excision. Prospectively, 32 patients with gynecomastia under tumescent anaesthesia and sedation underwent laser lipolysis with 980 nm diode laser, 15W continuous emission and 8 to 12 kJ energy per breast. Externally cold air was used to protect the skin. No drainages were used but a compressive bandage. Patients evaluated results on a VAS scale. Two doctors evaluated results comparing before and 6 month after photographs and also measured the areola and chest diameter. Twenty three patients considered results as Very Good, 7 Good and 2 Fair Cutaneous retraction of the areola was noticeable one month after the surgery and was maximum 6 months after. Evaluation by doctors was 26 Very Good, 5 Good and 1 Fair. There were no burns, ischemia or lesions in areolas or nipples. Laser assisted liposuction is a simple and efficacious technique, barely traumatic and permits a rapid reincorporation to normal activities.

Automated consensus contour building for prostate MRI.

Science.gov (United States)

Khalvati, Farzad

2014-01-01

Inter-observer variability is the lack of agreement among clinicians in contouring a given organ or tumour in a medical image. The variability in medical image contouring is a source of uncertainty in radiation treatment planning. Consensus contour of a given case, which was proposed to reduce the variability, is generated by combining the manually generated contours of several clinicians. However, having access to several clinicians (e.g., radiation oncologists) to generate a consensus contour for one patient is costly. This paper presents an algorithm that automatically generates a consensus contour for a given case using the atlases of different clinicians. The algorithm was applied to prostate MR images of 15 patients manually contoured by 5 clinicians. The automatic consensus contours were compared to manual consensus contours where a median Dice similarity coefficient (DSC) of 88% was achieved.

Segmentation of breast ultrasound images based on active contours using neutrosophic theory.

Science.gov (United States)

Lotfollahi, Mahsa; Gity, Masoumeh; Ye, Jing Yong; Mahlooji Far, A

2018-04-01

Ultrasound imaging is an effective approach for diagnosing breast cancer, but it is highly operator-dependent. Recent advances in computer-aided diagnosis have suggested that it can assist physicians in diagnosis. Definition of the region of interest before computer analysis is still needed. Since manual outlining of the tumor contour is tedious and time-consuming for a physician, developing an automatic segmentation method is important for clinical application. The present paper represents a novel method to segment breast ultrasound images. It utilizes a combination of region-based active contour and neutrosophic theory to overcome the natural properties of ultrasound images including speckle noise and tissue-related textures. First, due to inherent speckle noise and low contrast of these images, we have utilized a non-local means filter and fuzzy logic method for denoising and image enhancement, respectively. This paper presents an improved weighted region-scalable active contour to segment breast ultrasound images using a new feature derived from neutrosophic theory. This method has been applied to 36 breast ultrasound images. It generates true-positive and false-positive results, and similarity of 95%, 6%, and 90%, respectively. The purposed method indicates clear advantages over other conventional methods of active contour segmentation, i.e., region-scalable fitting energy and weighted region-scalable fitting energy.

Effect of laser-assisted zona thinning, during assisted reproduction, on pregnancy outcome in women with endometriosis: randomized controlled trial.

Science.gov (United States)

Nada, Adel Mohamed; El-Noury, Amr; Al-Inany, Hesham; Bibars, Mamdouh; Taha, Tamer; Salama, Sameh; Hassan, Fatma; Zein, Eman

2018-02-01

To compare the ICSI-ET outcomes in patients with endometriosis with or without laser-assisted zona pellucida thinning. Randomized controlled trial. The study was conducted in the Obstetrics & Gynecology Department, Cairo University hospital, and two private IVF centers in Cairo & Beni-Suif from July 2015 to January 2017 upon infertile and known endometriosis patients who planned to do ICSI-ET. Before randomization, all patients received the same ovarian stimulation preparation, oocyte retrieval procedures, and the same intracytoplasmic sperm injection procedures. After randomization, laser-assisted hatching was performed only for embryos of 158 patients, while the other group (n = 150) no laser-assisted hatching was made. The verification of pregnancy was achieved by the serum hCG concentration 14 days after the embryo transfer, and the clinical pregnancy was confirmed 2 weeks later by the presence of gestational sac with pulsating fetal pole on vaginal ultrasonography. The main outcome measures were the clinical pregnancy rate and the clinical implantation rate. Both groups were comparable with regard their baseline characteristics, baseline hormonal profile, the ovarian stimulation characteristics, and the ovulation characteristics. The mean number of embryos developed per patient and the mean transferred number of embryos per patient were comparable between groups (p value > 0.05). The implantation rate was significantly higher (p value 0.002) in the study group than the control group with an odds ratio of 1.86 (CI 95% 1.24-2.80) and NNT 13.81 (CI 95% 8.35-39.94). The clinical pregnancy rate, was significantly (p value 0.022) higher in the study group than in the control group with an odds ratio of 1.79 (CI 95% 1.05-3.06) and NNT 9.57 (CI 95% 5.03-98.99). That laser-assisted hatching by thinning of the zona pellucida may be a suitable method to improve the ICSI-ET outcomes, in term of the implantation and the pregnancy rates, in cases of endometriosis. Pan

Design and Study of a Next-Generation Computer-Assisted System for Transoral Laser Microsurgery

Directory of Open Access Journals (Sweden)

Nikhil Deshpande PhD

2018-05-01

Full Text Available Objective To present a new computer-assisted system for improved usability, intuitiveness, efficiency, and controllability in transoral laser microsurgery (TLM. Study Design Pilot technology feasibility study. Setting A dedicated room with a simulated TLM surgical setup: surgical microscope, surgical laser system, instruments, ex vivo pig larynxes, and computer-assisted system. Subjects and Methods The computer-assisted laser microsurgery (CALM system consists of a novel motorized laser micromanipulator and a tablet- and stylus-based control interface. The system setup includes the Leica 2 surgical microscope and the DEKA HiScan Surgical laser system. The system was validated through a first-of-its-kind observational study with 57 international surgeons with varied experience in TLM. The subjects performed real surgical tasks on ex vivo pig larynxes in a simulated TLM scenario. The qualitative aspects were established with a newly devised questionnaire assessing the usability, efficiency, and suitability of the system. Results The surgeons evaluated the CALM system with an average score of 6.29 (out of 7 in ease of use and ease of learning, while an average score of 5.96 was assigned for controllability and safety. A score of 1.51 indicated reduced workload for the subjects. Of 57 subjects, 41 stated that the CALM system allows better surgical quality than the existing TLM systems. Conclusions The CALM system augments the usability, controllability, and efficiency in TLM. It enhances the ergonomics and accuracy beyond the current state of the art, potentially improving the surgical safety and quality. The system offers the intraoperative automated scanning of customized long incisions achieving uniform resections at the surgical site.

Laser assisted cold spraying of aluminium alloy powder on stainless steel substrate

CSIR Research Space (South Africa)

Tlotleng, Monnamme

2012-12-01

Full Text Available A newly acquired, in-house assembled laser assisted cold spraying coating technique had to be commissioned for use in future for metal coating for different industrial application which include, but not limited to chemical and orthopedic industries...

Laser-assisted turning of components made of silicon-nitride ceramics

International Nuclear Information System (INIS)

Klocke, F.; Bausch, S.

2001-01-01

The manufacture of high-precision parts made of silicon-nitride ceramic, such as roller bearing rings or valves, currently involves finishing in the form of time and cost intensive grinding operations. This has resulted in demands for the development of more efficient machining techniques and for the subsequent provision of these within a manufacturing environment. A prototype of a precision lathe with an integrated high power diode laser for laser-assisted turning has been developed at the Fraunhofer IPT in close co-operation with industrial partners. When the workpiece is heated continuously by the laser, the resultant localized material softening enables the ceramic to be machined using a defined cutting edge. The application of this technique allows complex silicon nitride ceramic parts with surface qualities of up to R a = 0.3 μm to be produced considerably more flexibly than before, with no requirement for cooling lubricant. (author)

Improving the performance of nickel-coated fluorine-doped tin oxide thin films by magnetic-field-assisted laser annealing

Energy Technology Data Exchange (ETDEWEB)

Li, Bao-jia, E-mail: li_bjia@126.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013 (China); Huang, Li-jing [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013 (China); Ren, Nai-fei [Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013 (China); School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Kong, Xia; Cai, Yun-long; Zhang, Jie-lu [Jiangsu Tailong Reduction Box Co. Ltd., Taixing 225400 (China)

2015-10-01

Highlights: • Ni/FTO films were prepared by sputtering Ni layers on commercial FTO glass. • The as-prepared Ni/FTO films underwent magnetic-field-assisted laser annealing. • Magnetic field and laser fluence were crucial for improving quality of the films. • All Ni/FTO films displayed enhanced compactness after magnetic laser annealing. • Magnetic laser annealing using a fluence of 0.9 J/cm{sup 2} led to the best film quality. - Abstract: Nickel-coated fluorine-doped tin oxide (Ni/FTO) thin films were prepared by sputtering Ni layers on commercial FTO glass. The as-prepared Ni/FTO films underwent nanosecond pulsed laser annealing in an external magnetic field (0.4 T). The effects of the presence of magnetic field and laser fluence on surface morphology, crystal structure and photoelectric properties of the films were investigated. All the films displayed enhanced compactness after magnetic-field-assisted laser annealing. It was notable that both crystallinity and grain size of the films gradually increased with increasing laser fluence from 0.6 to 0.9 J/cm{sup 2}, and then decreased slightly with an increase in laser fluence to 1.1 J/cm{sup 2}. As a result, the film obtained by magnetic-field-assisted laser annealing using a fluence of 0.9 J/cm{sup 2} had the best overall photoelectric property with an average transmittance of 81.2%, a sheet resistance of 5.5 Ω/sq and a figure of merit of 2.27 × 10{sup −2} Ω{sup −1}, outperforming that of the film obtained by pure laser annealing using the same fluence.

Pitch contour impairment in congenital amusia: New insights from the Self-paced Audio-visual Contour Task (SACT).

Science.gov (United States)

Lu, Xuejing; Sun, Yanan; Ho, Hao Tam; Thompson, William Forde

2017-01-01

Individuals with congenital amusia usually exhibit impairments in melodic contour processing when asked to compare pairs of melodies that may or may not be identical to one another. However, it is unclear whether the impairment observed in contour processing is caused by an impairment of pitch discrimination, or is a consequence of poor pitch memory. To help resolve this ambiguity, we designed a novel Self-paced Audio-visual Contour Task (SACT) that evaluates sensitivity to contour while placing minimal burden on memory. In this task, participants control the pace of an auditory contour that is simultaneously accompanied by a visual contour, and they are asked to judge whether the two contours are congruent or incongruent. In Experiment 1, melodic contours varying in pitch were presented with a series of dots that varied in spatial height. Amusics exhibited reduced sensitivity to audio-visual congruency in comparison to control participants. To exclude the possibility that the impairment arises from a general deficit in cross-modal mapping, Experiment 2 examined sensitivity to cross-modal mapping for two other auditory dimensions: timbral brightness and loudness. Amusics and controls were significantly more sensitive to large than small contour changes, and to changes in loudness than changes in timbre. However, there were no group differences in cross-modal mapping, suggesting that individuals with congenital amusia can comprehend spatial representations of acoustic information. Taken together, the findings indicate that pitch contour processing in congenital amusia remains impaired even when pitch memory is relatively unburdened.

Chiropractic management of Bell palsy with low level laser and manipulation: a case report.

Science.gov (United States)

Rubis, Lisa M

2013-12-01

The purpose of this case report is to describe chiropractic management including the use of cold laser and chiropractic manipulation in the treatment of a patient with Bell palsy. A 40-year-old male patient had a 10-day history of facial paralysis on his left side, including the inability to close his left eye, which also had tearing and a burning sensation. The patient had trouble lifting his left lip and complained of drooling while brushing his teeth. There was no previous history of similar symptoms or a recent infection. Prior treatment had included oral steroids. The patient was treated with low-level laser therapy and chiropractic manipulation 2 times in 4 days. The laser was applied along the course of the facial nerve for 30 seconds at each point and for 1 minute at the stylomastoid foramen. The laser used was a GaAs class 4 laser with a wavelength of 910 nm. The patient perceived a 70% to 80% improvement of facial movement after the first treatment. After the second treatment, the patient reported full control of his facial movements. A patient with acute facial paralysis appeared to have complete resolution of his symptoms following the application of low-level laser therapy and chiropractic manipulation.

High fluence deposition of polyethylene glycol films at 1064 nm by matrix assisted pulsed laser evaporation (MAPLE)

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Kingshott, P.

2007-01-01

Matrix assisted pulsed laser evaporation (MAPLE) has been applied for deposition of thin polyethylene glycol (PEG) films with infrared laser light at 1064 nm. We have irradiated frozen targets (of 1 wt.% PEG dissolved in water) and measured the deposition rate in situ with a quartz crystal 2...... microbalance. The laser fluence needed to produce PEG films turned out to be unexpectedly high with a threshold of 9 J/cm(2) and the deposition rate was much lower than that with laser light at 355 nm. Results from matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI......-TOF-MS) analysis demonstrate that the chemistry, molecular weight and polydispersity of the PEG films were identical to the starting material. Studies of the film surface with scanning electron microscopy (SEM) indicate that the Si-substrate is covered by a relatively homogenous PEG film with few bare spots. (c...

Integrated cooling-vacuum-assisted 1540-nm erbium:glass laser is effective in treating mild-to-moderate acne vulgaris.

Science.gov (United States)

Politi, Y; Levi, A; Enk, C D; Lapidoth, M

2015-12-01

Acne treatment by a mid-infrared laser may be unsatisfactory due to deeply situated acne-affected sebaceous glands which serve as its target. Skin manipulation by vacuum and contact cooling may improve laser-skin interaction, reduce pain sensation, and increase overall safety and efficacy. To evaluate the safety and efficacy of acne treatment using an integrated cooling-vacuum-assisted 1540-nm erbium:glass laser, a prospective interventional study was conducted. It included 12 patients (seven men and five women) suffering from mild-to-moderate acne vulgaris. The device utilizes a mid-infrared 1540-nm laser (Alma Lasers Ltd. Caesarea, Israel), which is integrated with combined cooling-vacuum-assisted technology. An acne lesion is initially manipulated upon contact by a vacuum-cooling-assisted tip, followed by three to four stacked laser pulses (500-600 mJ, 4 mm spot size, and frequency of 2 Hz). Patients underwent four to six treatment sessions with a 2-week interval and were followed-up 1 and 3 months after the last treatment. Clinical photographs were taken by high-resolution digital camera before and after treatment. Clinical evaluation was performed by two independent dermatologists, and results were graded on a scale of 0 (exacerbation) to 4 (76-100 % improvement). Patients' and physicians' satisfaction was also recorded. Pain perception and adverse effects were evaluated as well. All patients demonstrated a moderate to significant improvement (average score of 3.6 and 2.0 within 1 and 3 months, respectively, following last treatment session). No side effects, besides a transient erythema, were observed. Cooling-vacuum-assisted 1540-nm laser is safe and effective for the treatment of acne vulgaris.

Fractional erbium-doped yttrium aluminum garnet laser-assisted drug delivery of hydroquinone in the treatment of melasma

Science.gov (United States)

Badawi, Ashraf M; Osman, Mai Abdelraouf

2018-01-01

Background Melasma is a difficult-to-treat hyperpigmentary disorder. Ablative fractional laser (AFL)-assisted delivery of topically applied drugs to varied targets in the skin has been an area of ongoing study and research. Objective The objective of this study was to evaluate the efficacy and safety of fractional erbium-doped yttrium aluminum garnet (Er:YAG) laser as an assisted drug delivery for enhancing topical hydroquinone (HQ) permeation into the skin of melasma patients. Patients and methods Thirty female patients with bilateral melasma were randomly treated in a split-face controlled manner with a fractional Er:YAG laser followed by 4% HQ cream on one side and 4% HQ cream alone on the other side. All patients received six laser sessions with a 2-week interval. The efficacy of treatments was determined through photographs, dermoscopic photomicrographs and Melasma Area Severity Index (MASI) score, all performed at baseline and at 12 weeks of starting therapy. The patient’s level of satisfaction was also recorded. Results Er:YAG laser + HQ showed significantly better results (plaser + HQ side vs HQ side. Minor reversible side effects were observed on both sides. Conclusion AFL-assisted delivery of HQ is a safe and effective method for the treatment of melasma. PMID:29379308

Optimal dye concentration and irradiance for laser-assisted vascular anastomosis.

Science.gov (United States)

Ren, Zhen; Xie, Hua; Lagerquist, Kathryn A; Burke, Allen; Prahl, Scott; Gregory, Kenton W; Furnary, Anthony P

2004-04-01

This investigation was done in order to find optimal indocyanine green (ICG) concentration and energy irradiance in laser vascular welding. Many studies have shown that laser tissue welding with albumin solder/ICG may be an effective technique in surgical reconstruction. However, there are few reports regarding optimal laser settings and concentrations of ICG within the albumin solder in laser-assisted vascular anastomosis. Porcine carotid artery strips (n = 120) were welded in end-to-end by diode laser with 50% albumin solder of 0.01, 0.1, and 1.0 mM ICG at irradiance of 27.7, 56.7, and 76.9 W/cm(2), respectively. Temperature was measured by inserting thermocouples outside and inside the vessel. Tensile strength and histology were studied. Temperature and strength of the anastomosis significantly decreased (all p < 0.05) with increasing ICG concentration at 56.7 W/cm(2). Histological study showed minimal thermal injury limited to adventitia and no appreciable difference between all groups. ICG concentration within solder is the most important factor affecting both vascular temperature and tensile strength. The optimal balance between strength and minimal thermal injury may be achieved primarily at 56.7 W/cm(2) and 0.01 mM ICG.

American Academy of Facial Plastic and Reconstructive Surgery

Science.gov (United States)

... Photos Find a Surgeon For Physicians For Facial Plastic Surgery Assistants About the OFPSA OFPSA Officers Become a Member Member of the Year Award For The Media Contact Us Statistics Press Releases In the News Before & After Photos Humanitarian Programs Contact Us AAFPRS ...

Off-shell properties of the second-order Born approximation for laser-assisted potential scattering

International Nuclear Information System (INIS)

Trombetta, F.

1991-01-01

A formal method is presented to evaluate the second-order Born approximation of the laser-assisted potential scattering. It is an implicit closure technique that includes intermediate virtual-state transitions and enables one to find the exact explicit expression of the transition amplitude. This is of interest from two standpoints: first, one can deal with ranges of parameters in which the first-order Born approximation is a poor one; second, one can set limits of on-shell approximations that are also widely used to analyze recent laser-assisted experiments. The off-shell character yields new terms in the exact amplitude, and in particular, it is shown to play a crucial role in forward scattering from a long-range potential

What's behind the mask? A look at blood flow changes with prolonged facial pressure and expression using laser Doppler imaging.

Science.gov (United States)

Van-Buendia, Lan B; Allely, Rebekah R; Lassiter, Ronald; Weinand, Christian; Jordan, Marion H; Jeng, James C

2010-01-01

Clinically, the initial blanching in burn scar seen on transparent plastic face mask application seems to diminish with time and movement requiring mask alteration. To date, studies quantifying perfusion with prolonged mask use do not exist. This study used laser Doppler imaging (LDI) to assess perfusion through the transparent face mask and movement in subjects with and without burn over time. Five subjects fitted with transparent face masks were scanned with the LDI on four occasions. The four subjects without burn were scanned in the following manner: 1) no mask, 2) mask on while at rest, 3) mask on with alternating intervals of sustained facial expression and rest, and 4) after mask removal. Images were acquired every 3 minutes throughout the 85-minute study period. The subject with burn underwent a shortened scanning protocol to increase comfort. Each face was divided into five regions of interest for analysis. Compared with baseline, mask application decreased perfusion significantly in all subjects (P mask removal, all regions of the face demonstrated a hyperemic effect with the chin (P = .05) and each cheek (P mask removal. Perfusions remain constantly low while wearing the face mask, despite changing facial expressions. Changing facial expressions with the mask on did not alter perfusion. Hyperemic response occurs on removal of the mask. This study exposed methodology and statistical issues worth considering when conducting future research with the face, pressure therapy, and with LDI technology.

Pitch contour impairment in congenital amusia: New insights from the Self-paced Audio-visual Contour Task (SACT.

Directory of Open Access Journals (Sweden)

Xuejing Lu

Full Text Available Individuals with congenital amusia usually exhibit impairments in melodic contour processing when asked to compare pairs of melodies that may or may not be identical to one another. However, it is unclear whether the impairment observed in contour processing is caused by an impairment of pitch discrimination, or is a consequence of poor pitch memory. To help resolve this ambiguity, we designed a novel Self-paced Audio-visual Contour Task (SACT that evaluates sensitivity to contour while placing minimal burden on memory. In this task, participants control the pace of an auditory contour that is simultaneously accompanied by a visual contour, and they are asked to judge whether the two contours are congruent or incongruent. In Experiment 1, melodic contours varying in pitch were presented with a series of dots that varied in spatial height. Amusics exhibited reduced sensitivity to audio-visual congruency in comparison to control participants. To exclude the possibility that the impairment arises from a general deficit in cross-modal mapping, Experiment 2 examined sensitivity to cross-modal mapping for two other auditory dimensions: timbral brightness and loudness. Amusics and controls were significantly more sensitive to large than small contour changes, and to changes in loudness than changes in timbre. However, there were no group differences in cross-modal mapping, suggesting that individuals with congenital amusia can comprehend spatial representations of acoustic information. Taken together, the findings indicate that pitch contour processing in congenital amusia remains impaired even when pitch memory is relatively unburdened.

Repairing a Facial Cleft by Polyether-Ether-Ketone Implant Combined With Titanium Mesh.

Science.gov (United States)

Deng, Yuan; Tang, Weiwei; Li, Zhengkang

2018-05-15

The Tessier Number 4 cleft is one of the rarest, most complex craniofacial anomalies that presents difficulties in surgical treatment. In this article, we report a case of simultaneous facial depression, eye displacement, and medial canthus deformity. In this case, the maxillary bony defect was reconstructed using computer-assisted design computer-assisted manufacturing (CAD-CAM) polyether-ether-ketone (PEEK) material, and the orbital floor defect was repaired with AO prefabricated titanium mesh. Additionally, the medial canthus was modified with canthopexy and a single Z-plasty flap. Owing to its relative rarity and varied clinical presentations, no definitive operative methods have been accepted for Tessier No. 4 facial cleft. This study presents the combination of CAD-CAM manufactured PEEK material and titanium mesh as an alternative approach for reconstructing the bony defect of Tessier No. 4 facial clefts.

Laser-assisted preparation and photoelectric properties of grating-structured Pt/FTO thin films

Energy Technology Data Exchange (ETDEWEB)

Ren, Nai-fei, E-mail: rnf_ujs@126.com [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013 (China); Huang, Li-jing, E-mail: lij_huang@126.com [Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013 (China); School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Li, Bao-jia [Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013 (China); School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Zhou, Ming [Jiangsu Provincial Key Laboratory of Center for Photon Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013 (China); The State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

2014-09-30

Highlights: • Pt layers were deposited by DC magnetron sputtering on commercial FTO glasses. • Pt/FTO films were irradiated by laser for inducing gratings and annealing. • An ideal grating-structured Pt/FTO film was obtained using a fluence of 1.05 J/cm{sup 2}. • The grating-structured Pt/FTO film exhibited excellent photoelectric properties. • Laser-assisted treatment is effective for improving performance of FTO-based films. - Abstract: In order to improve the transparency and conductivity of commercial fluorine-doped tin oxide (FTO) glass, platinum (Pt) layers were deposited on the FTO film by direct current (DC) magnetron sputtering, followed by being irradiating with a 532 nm nanosecond pulsed laser for the dual purpose of inducing grating structures and annealing. Introducing a Pt layer decreased the average transmittance (400–800 nm) and the sheet resistance of the initial FTO film from 80.2% and 8.4 Ω/sq to 68.6% and 7.9 Ω/sq, respectively. The ideal grating-structured Pt/FTO film was obtained by laser irradiation with a fluence of 1.05 J/cm{sup 2}, and X-ray diffraction (XRD) analysis confirmed that this film underwent optimal annealing. As a result, it exhibited an average transmittance (400–800 nm) of 84.1% and a sheet resistance of 6.8 Ω/sq. These results indicated that laser-assisted treatment combined with introduction of metal layer can effectively improve photoelectric properties of FTO single-layer films.

Digital extraction of interference fringe contours

International Nuclear Information System (INIS)

Mastin, G.A.; Ghiglia, D.C.

1985-01-01

Two basic techniques for extracting interferogram contours have been discussed. The first is a global contour extracton technique based on the fast Fourier transform. The second extracts individual contours with a thinning algorithm using logical neighborhood transformations

Toward a universal, automated facial measurement tool in facial reanimation.

Science.gov (United States)

Hadlock, Tessa A; Urban, Luke S

2012-01-01

To describe a highly quantitative facial function-measuring tool that yields accurate, objective measures of facial position in significantly less time than existing methods. Facial Assessment by Computer Evaluation (FACE) software was designed for facial analysis. Outputs report the static facial landmark positions and dynamic facial movements relevant in facial reanimation. Fifty individuals underwent facial movement analysis using Photoshop-based measurements and the new software; comparisons of agreement and efficiency were made. Comparisons were made between individuals with normal facial animation and patients with paralysis to gauge sensitivity to abnormal movements. Facial measurements were matched using FACE software and Photoshop-based measures at rest and during expressions. The automated assessments required significantly less time than Photoshop-based assessments.FACE measurements easily revealed differences between individuals with normal facial animation and patients with facial paralysis. FACE software produces accurate measurements of facial landmarks and facial movements and is sensitive to paralysis. Given its efficiency, it serves as a useful tool in the clinical setting for zonal facial movement analysis in comprehensive facial nerve rehabilitation programs.

Numerical modeling of laser assisted tape winding process

Science.gov (United States)

Zaami, Amin; Baran, Ismet; Akkerman, Remko

2017-10-01

Laser assisted tape winding (LATW) has become more and more popular way of producing new thermoplastic products such as ultra-deep sea water riser, gas tanks, structural parts for aerospace applications. Predicting the temperature in LATW has been a source of great interest since the temperature at nip-point plays a key role for mechanical interface performance. Modeling the LATW process includes several challenges such as the interaction of optics and heat transfer. In the current study, numerical modeling of the optical behavior of laser radiation on circular surfaces is investigated based on a ray tracing and non-specular reflection model. The non-specular reflection is implemented considering the anisotropic reflective behavior of the fiber-reinforced thermoplastic tape using a bidirectional reflectance distribution function (BRDF). The proposed model in the present paper includes a three-dimensional circular geometry, in which the effects of reflection from different ranges of the circular surface as well as effect of process parameters on temperature distribution are studied. The heat transfer model is constructed using a fully implicit method. The effect of process parameters on the nip-point temperature is examined. Furthermore, several laser distributions including Gaussian and linear are examined which has not been considered in literature up to now.

Image Interpolation with Geometric Contour Stencils

Directory of Open Access Journals (Sweden)

Pascal Getreuer

2011-09-01

Full Text Available We consider the image interpolation problem where given an image vm,n with uniformly-sampled pixels vm,n and point spread function h, the goal is to find function u(x,y satisfying vm,n = (h*u(m,n for all m,n in Z. This article improves upon the IPOL article Image Interpolation with Contour Stencils. In the previous work, contour stencils are used to estimate the image contours locally as short line segments. This article begins with a continuous formulation of total variation integrated over a collection of curves and defines contour stencils as a consistent discretization. This discretization is more reliable than the previous approach and can effectively distinguish contours that are locally shaped like lines, curves, corners, and circles. These improved contour stencils sense more of the geometry in the image. Interpolation is performed using an extension of the method described in the previous article. Using the improved contour stencils, there is an increase in image quality while maintaining similar computational efficiency.

Spectrally accurate contour dynamics

International Nuclear Information System (INIS)

Van Buskirk, R.D.; Marcus, P.S.

1994-01-01

We present an exponentially accurate boundary integral method for calculation the equilibria and dynamics of piece-wise constant distributions of potential vorticity. The method represents contours of potential vorticity as a spectral sum and solves the Biot-Savart equation for the velocity by spectrally evaluating a desingularized contour integral. We use the technique in both an initial-value code and a newton continuation method. Our methods are tested by comparing the numerical solutions with known analytic results, and it is shown that for the same amount of computational work our spectral methods are more accurate than other contour dynamics methods currently in use

Preliminary results of laser-assisted sealing of hand-sewn canine esophageal anastomoses

Science.gov (United States)

Auteri, Joseph S.; Oz, Mehmet C.; Sanchez, Juan A.; Bass, Lawrence S.; Jeevanandam, Valluvan; Williams, Matthew R.; Smith, Craig R.; Treat, Michael R.

1991-07-01

Dehiscence rates of esophageal anastomoses range between 5 and 20%. Causative factors include ischemia, tension, foreign body reaction, microabscesses, and the negative pressure within the thoracic cavity. Laser assisted tissue sealing (LATS) has been shown to decrease anastomotic leakage rates in other tissues. Using a canine model the efficacy of LATS in enhancing single layer hand swen intrathoracic esophageal anastomoses was assessed. Via a left thoracotomy, paired two centimeter transverse incisions (one laser sealed, one control) were made in the proximal and distal esophagus in nine dogs. Both were sewn using a single layer of 4-0 polyglycolic acid. A combination of albumin (0.2 cc), sodium hyaluronate (0.4 cc), and indocyanine green (1 gtt) was applied to one of the randomly chosen hand sewn repairs. The albumin/hyaluronate combination is used to provide a protein matrix across the anastomosis for ingrowth of fibroblasts. Indocyanine green dye selectively absorbs at OM805 nm which matches the output of the diode laser (808 +/- 1 nm), thus improving uptake of laser energy by the targeted tissues. The anastomosis was then exposed to continuous wave diode laser energy for OM2 minutes at a power density of 9.6 W/cm2. The esophagus was recovered either at the time of sealing or two days postoperatively and infused with saline under pressure. Bursting pressures were considered the point of initial saline leakage. At time 0 there was no significant difference in bursting pressures between the LATS group and controls. However, at two days postoperatively controls burst at 121 +/- 14 mmHg while the laser assisted anastomoses burst at 295 +/- 35 mmHg (p anastomoses revealed minimal thermal injury to the mucosal surface initially, with some regeneration of mucosal lining at two days postoperatively. No foreign body reaction to the solder was noted. Laser reinforcement of single layer hand sewn esophageal anastomoses appears to increase bursting pressure and may result

High incidence of rainbow glare after femtosecond laser assisted-LASIK using the upgraded FS200 femtosecond laser.

Science.gov (United States)

Zhang, Yu; Chen, Yue-Guo

2018-03-05

To compare the incidence of rainbow glare (RG) after femtosecond laser assisted-LASIK (FS-LASIK) using the upgraded FS200 femtosecond laser with different flap cut parameter settings. A consecutive series of 129 patients (255 eyes) who underwent FS-LASIK for correcting myopia and/or astigmatism using upgraded WaveLight FS200 femtosecond laser with the original settings was included in group A. Another consecutive series of 129 patients (255 eyes) who underwent FS-LASIK using upgraded WaveLight FS200 femtosecond laser with flap cut parameter settings changed (decreased pulse energy, spot and line separation) was included in group B. The incidence and fading time of RG, confocal microscopic image and postoperative clinical results were compared between the two groups. There were no differences between the two groups in age, baseline refraction, excimer laser ablation depth, postoperative uncorrected visual acuity and refraction. The incidence rate of RG in group A (35/255, 13.73%) was significantly higher than that in group B (4/255, 1.57%) (P  0.05).The confocal microscopic images showed wider laser spot spacing in group A than group B. The incidence of RG was significantly correlated with age and grouping (P laser with original flap cut parameter settings could increase the incidence of RG. The narrower grating size and lower pulse energy could ameliorate this side effect.

Laser-assisted chemical vapor deposition setup for fast synthesis of graphene patterns

Science.gov (United States)

Zhang, Chentao; Zhang, Jianhuan; Lin, Kun; Huang, Yuanqing

2017-05-01

An automatic setup based on the laser-assisted chemical vapor deposition method has been developed for the rapid synthesis of graphene patterns. The key components of this setup include a laser beam control and focusing unit, a laser spot monitoring unit, and a vacuum and flow control unit. A laser beam with precision control of laser power is focused on the surface of a nickel foil substrate by the laser beam control and focusing unit for localized heating. A rapid heating and cooling process at the localized region is induced by the relative movement between the focalized laser spot and the nickel foil substrate, which causes the decomposing of gaseous hydrocarbon and the out-diffusing of excess carbon atoms to form graphene patterns on the laser scanning path. All the fabrication parameters that affect the quality and number of graphene layers, such as laser power, laser spot size, laser scanning speed, pressure of vacuum chamber, and flow rates of gases, can be precisely controlled and monitored during the preparation of graphene patterns. A simulation of temperature distribution was carried out via the finite element method, providing a scientific guidance for the regulation of temperature distribution during experiments. A multi-layer graphene ribbon with few defects was synthesized to verify its performance of the rapid growth of high-quality graphene patterns. Furthermore, this setup has potential applications in other laser-based graphene synthesis and processing.

Surface morphology of thin lysozyme films produced by matrix-assisted pulsed laser evaporation (MAPLE)

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Pryds, Nini

2007-01-01

Thin films of the protein, lysozyme, have been deposited by the matrix-assisted pulsed laser evaporation (MAPLE) technique. Frozen targets of 0.3-1.0 wt.% lysozyme dissolved in ultrapure water were irradiated by laser light at 355 mn with a fluence of 2 J/cm(2). The surface quality of the thin....... The concentration of lysozyme in the ice matrix apparently does not play any significant role for the morphology of the film. The morphology obtained with MAPLE has been compared with results for direct laser irradiation of a pressed lysozyme sample (i.e. pulsed laser deposition (PLD)). (C) 2007 Elsevier B.V. All...

UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

International Nuclear Information System (INIS)

Toftmann, B.; Papantonakis, M.R.; Auyeung, R.C.Y.; Kim, W.; O'Malley, S.M.; Bubb, D.M.; Horwitz, J.S.; Schou, J.; Johansen, P.M.; Haglund, R.F.

2004-01-01

A comparative study of thin film production based on gentle laser-ablation techniques has been carried out with the luminescent polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. Using a free-electron laser films were made by resonant infrared pulsed laser deposition (RIR-PLD). For the first time resonant infrared matrix assisted pulsed laser evaporation (RIR-MAPLE) was successfully demonstrated on a luminescent polymer system. In addition to this, an excimer laser has been used for UV-MAPLE depositions at 193 and 248-nm irradiation. Films deposited onto NaCl and quartz substrates were analyzed by Fourier transform infrared spectroscopy, UV-visible absorbance and photoluminescence. Photoluminescent material was deposited by RIR-MAPLE and 248-nm MAPLE, while the RIR-PLD and 193-nm-MAPLE depositions displayed the smoothest surfaces but did not show photoluminescence

UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

DEFF Research Database (Denmark)

Christensen, Bo Toftmann; Papantonalis, M.R.; Auyeung, R.C.Y.

2004-01-01

-PLD). For the first time resonant infrared matrix assisted pulsed laser evaporation (RIR-MAPLE) was successfully demonstrated on a luminescent polymer system. In addition to this, an excimer laser has been used for UV-MAPLE depositions at 193 and 248-nm irradiation. Films deposited onto NaCl and quartz substrates......A comparative study of thin film production based on gentle laser-ablation techniques has been carried out with the luminescent polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. Using a free-electron laser films were made by resonant infrared pulsed laser deposition (RIR...... were analyzed by Fourier transform infrared spectroscopy, UV-visible absorbance and photoluminescence. Photoluminescent material was deposited by RIR-MAPLE and 248-nm MAPLE, while the RIR-PLD and 193-nm-MAPLE depositions displayed the smoothest surfaces but did not show photoluminescence. (C) 2003...

[Hybrid (femtosecond laser-assisted) phaco surgery and the state of the macula].

Science.gov (United States)

Avetisov, K S; Bol'shunov, A V; Avetisov, S E; Yusef, Y N; Ivanov, M N; Sobol, E N; Sakalova, E D

The review covers different aspects of the impact of femtosecond laser-assisted cataract surgery on the state of the macular zone of the retina. Literature search has revealed inconsistency of the published data and indicated the need for a more detailed study of this problem.

The influence of automation on tumor contouring

NARCIS (Netherlands)

Aselmaa, A.; van Herk, Marcel; Song, Y.; Goossens, R.H.M.; Laprie, Anne

2017-01-01

Fully or semi-automatic contouring tools are increasingly being used in the tumor contouring task for radiotherapy. While the fully automatic contouring tools have not reached sufficient efficiency, the semi-automatic contouring tools balance more effectively between the human interaction and

Assessment of residual stress of 7050-T7452 aluminum alloy forging using the contour method

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zheng [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Yang, Yinfei, E-mail: yyfgoat@nuaa.edu.cn [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Li, Liang [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Chen, Bo; Tian, Hui [Xi’an Aircraft Industrial (Group) Co. Ltd., Xi’an 710000 (China)

2015-09-17

The cold-compression stress relief process has been used to reduce the quench-induced stresses in high-strength aerospace aluminum alloy forgings. However, this method does not completely relieve the stress. Longitudinal residual stresses in 7050-T7452 aluminum alloy forging were measured with contour method. The measuring procedure of the contour method including specimen cutting under clamps with a wire electrical discharge machine, contour measurement of the cut surface with a laser scanner, careful data processing and elastic finite element analysis was introduced in detail. In addition, multiple cuts were used to map cross sectional stress at different cut surfaces. Finally, the longitudinal residual stress throughout the cut plane was mapped, and through thickness longitudinal stress profiles were also analyzed. Investigated results suggest that spatial variation of stress distribution can be attributed to the non-uniform plastic deformation of the cold-compression stress relief process. The overall reduction of peak stress magnitudes is approximately 43–79%.

Assessment of residual stress of 7050-T7452 aluminum alloy forging using the contour method

International Nuclear Information System (INIS)

Zhang, Zheng; Yang, Yinfei; Li, Liang; Chen, Bo; Tian, Hui

2015-01-01

The cold-compression stress relief process has been used to reduce the quench-induced stresses in high-strength aerospace aluminum alloy forgings. However, this method does not completely relieve the stress. Longitudinal residual stresses in 7050-T7452 aluminum alloy forging were measured with contour method. The measuring procedure of the contour method including specimen cutting under clamps with a wire electrical discharge machine, contour measurement of the cut surface with a laser scanner, careful data processing and elastic finite element analysis was introduced in detail. In addition, multiple cuts were used to map cross sectional stress at different cut surfaces. Finally, the longitudinal residual stress throughout the cut plane was mapped, and through thickness longitudinal stress profiles were also analyzed. Investigated results suggest that spatial variation of stress distribution can be attributed to the non-uniform plastic deformation of the cold-compression stress relief process. The overall reduction of peak stress magnitudes is approximately 43–79%

The effect of low-level laser therapy on trismus and facial swelling following surgical extraction of a lower third molar.

Science.gov (United States)

Aras, Mutan Hamdi; Güngörmüş, Metin

2009-02-01

The purpose of this study was to evaluate the effect of low-level laser therapy (LLLT) on postoperative trismus and edema after the removal of mandibular third molars. Thirty-two patients who were to undergo surgical removal of lower third molars were studied. Patients were randomly allocated to two groups, LLLT and placebo. Patients in the LLLT group received 12 J (4 J/cm(2)) low-level laser irradiation to the operative side intraorally 1 cm from the target tissue, and to the masseter muscle extraorally immediately after surgery. In the placebo group the handpiece was inserted into the operative side intraorally and was applied to the masseter muscle extraorally each for 1 min, but laser power was not activated. Inter-incisal opening and facial swelling were evaluated on postoperative days 2 and 7. Student's t-test used to analyze the data. It was determined that the trismus and the swelling in LLLT group were significantly less than in the placebo group on postoperative days 2 and 7. Within the limitations of this study it can be concluded that LLLT can be beneficial for the reduction of postoperative trismus and swelling after third molar surgery.

Enhancement of Afterimage Colors by Surrounding Contours

Directory of Open Access Journals (Sweden)

Takao Sato

2011-05-01

Full Text Available Presenting luminance contours surrounding the adapted areas in test phase enhances color afterimages in both duration and color appearance. The presence of surrounding contour is crucial to some color phenomenon such as van Lier's afterimage, but the contour-effect itself has not been seriously examined. In this paper, we compared the contour-effect to color afterimages and to actually colored patches to examine the nature of color information subserving color-aftereffect. In the experiment, observers were adapted for 1 sec to a small colored square (red, green, yellow, or blue presented on a gray background. Then, a test field either with or without surrounding contour was presented. Observers matched the color of a test-patch located near the afterimage to the color of afterimage. It was found that the saturation of negative afterimage was almost doubled by the presence of surrounding contours. There was no effect of luminance contrast or polarity of contours. In contrast, no enhancement of saturation by surrounding contours was observed for actually colored patches even though the colors of patches were equalized to that of afterimage without contours. This dissociation in the contour-effect demonstrates the crucial difference between the color information for aftereffects and for ordinary bottom-up color perception.

Lasers in Facial Aesthetics- A Review

Directory of Open Access Journals (Sweden)

Dishant Shah

2014-01-01

Full Text Available Background: Lasers and optical technologies play a significant role in aesthetic and reconstructive surgery. The unique ability of optical technologies to target specific structures and layers in tissues to effect chemical, mechanical or thermal changes make them a powerful tool in cutaneous rejuvenation, hair removal, fat removal and treatment of vascular lesions such as port-wine stains, among many other procedures. With the development of adjunct techniques such as epidermal cooling, lasers and optical technologies have become more versatile and safe. The constant improvement of existing applications and the emergence of novel applications such as photodynamic therapy, nanoparticles, spectroscopy and noninvasive imaging continue to revolutionize aesthetic medicine by offering a minimally invasive alternative to traditional surgery. In the future, therapies will be based on individualized, maximum, safe radiant exposure to deliver optimal dosimetry. Lasers and optical technologies are headed toward safer, easier and more quantifiable individualized therapy.

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

Science.gov (United States)

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

2001-05-01

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

Effect of Laser-assisted and Conventional In-office Bleaching on Monomer Release from Microhybrid and Nanohybrid Composite.

Science.gov (United States)

Omrani, Ladan Ranjbar; Farjadfar, Shayan; Pedram, Parham; Sadray, Sima; Kamangar, Sedighe Sadat Hashemi; Chiniforoush, Nasim

2017-06-30

Bleaching might affect structural properties of composite materials, and lead to monomer release. This study aimed to evaluate the effect of Laser-assisted and conventional in-office bleaching on the release of BIS-GMA, TEGDMA, and UDMA monomers from a nanohybrid and a microhybrid BIS-GMA based composite. 32 samples of each composite, were divided into 4 subgroups; subgroup 1: Conventional in-office bleaching (CIB) with the Opalescence Boost PF 38% gel, subgroup 2: Laser-assisted bleaching (LBO) with the Opalescence Boost PF 38% gel, subgroup 3: Laser-assisted bleaching (LBH) with the JW Power bleaching gel, subgroup 4: (CO) control without bleaching. All the samples were immersed in tubes of 2cc Ethanol 75% medium. The released monomers were analyzed using the high performance liquid chromatography (HPLC) method 24 h, 7, and 28 days. Data's were analyzed by Univariate Analysis of Variance test followed by Tukeys HSD. The amount of TEGDMA monomer released was not significant. However, nanohybrid composites showed significantly more monomer release than microhybrid composites (P Bleaching by laser with JW Power Bleaching gel led to more monomer release in nanohybrid composite.

Hydroxyapatite thin films grown by pulsed laser deposition and matrix assisted pulsed laser evaporation: Comparative study

Science.gov (United States)

Popescu-Pelin, G.; Sima, F.; Sima, L. E.; Mihailescu, C. N.; Luculescu, C.; Iordache, I.; Socol, M.; Socol, G.; Mihailescu, I. N.

2017-10-01

Pulsed Laser Deposition (PLD) and Matrix Assisted Pulsed Laser Evaporation (MAPLE) techniques were applied for growing hydroxyapatite (HA) thin films on titanium substrates. All experiments were conducted in a reaction chamber using a KrF* excimer laser source (λ = 248 nm, τFWHM ≈ 25 ns). Half of the samples were post-deposition thermally treated at 500 °C in a flux of water vapours in order to restore crystallinity and improve adherence. Coating surface morphologies and topographies specific to the deposition method were evidenced by scanning electron, atomic force microscopy investigations and profilometry. They were shown to depend on deposition technique and also on the post-deposition treatment. Crystalline structure of the coatings evaluated by X-ray diffraction was improved after thermal treatment. Biocompatibility of coatings, cellular adhesion, proliferation and differentiation tests were conducted using human mesenchymal stem cells (MSCs). Results showed that annealed MAPLE deposited HA coatings were supporting MSCs proliferation, while annealed PLD obtained films were stimulating osteogenic differentiation.

University Students’ Willingness to Assist Fellow Students Who Experience Alcohol-Related Facial Flushing to Reduce Their Drinking

Directory of Open Access Journals (Sweden)

Lanyan Ding

2018-04-01

Full Text Available This study explored bystanders’ willingness to help a friend who flushes when drinking to reduce his/her drinking. Alcohol-related facial flushing is an indicator of an inherited variant enzyme, aldehyde dehydrogenase (ALDH, that impairs alcohol metabolism and increases drinkers’ lifetime risk of certain aerodigestive cancers. Individuals who flush should reduce their alcohol exposure, but they may continue to drink if social pressures and rules of etiquette make not drinking socially risky. The analysis used data from 2912 undergraduate students from 13 universities in southwestern, central and northeastern China from a survey asking how they respond to someone’s flushing in various scenarios. Latent class analysis grouped students by similar responses to flushing. A multinomial logistic regression explored how class membership was associated with knowledge, drinking status, and reactions to one’s own flushing. Five classes were derived from the latent class analysis, ranging from always intervene to mostly hesitate to help; in between were classes of students who were willing to help in some scenarios and hesitant in other scenarios. Only 11.6% students knew the connection between facial flushing and impaired alcohol metabolism, and knowledgeable students were somewhat more likely to assist when they saw someone flushing. In the absence of knowledge, other factors—such as drinking status, the gender of the bystander, the gender of the person who flushed, and degree of friendship with the person who flushed—determined how willing a person was to help someone reduce or stop drinking. Class membership was predicted by knowledge, gender, drinking status, and reactions to one’s own flushing. Of these 4 factors, knowledge and reactions to one’s own flushing could be influenced through alcohol education programs. It will take some time for alcohol education to catch up to and change social and cultural patterns of drinking. Meanwhile

University Students' Willingness to Assist Fellow Students Who Experience Alcohol-Related Facial Flushing to Reduce Their Drinking.

Science.gov (United States)

Ding, Lanyan; Yuen, Lok-Wa; Newman, Ian M; Shell, Duane F

2018-04-25

This study explored bystanders’ willingness to help a friend who flushes when drinking to reduce his/her drinking. Alcohol-related facial flushing is an indicator of an inherited variant enzyme, aldehyde dehydrogenase (ALDH), that impairs alcohol metabolism and increases drinkers’ lifetime risk of certain aerodigestive cancers. Individuals who flush should reduce their alcohol exposure, but they may continue to drink if social pressures and rules of etiquette make not drinking socially risky. The analysis used data from 2912 undergraduate students from 13 universities in southwestern, central and northeastern China from a survey asking how they respond to someone’s flushing in various scenarios. Latent class analysis grouped students by similar responses to flushing. A multinomial logistic regression explored how class membership was associated with knowledge, drinking status, and reactions to one’s own flushing. Five classes were derived from the latent class analysis, ranging from always intervene to mostly hesitate to help; in between were classes of students who were willing to help in some scenarios and hesitant in other scenarios. Only 11.6% students knew the connection between facial flushing and impaired alcohol metabolism, and knowledgeable students were somewhat more likely to assist when they saw someone flushing. In the absence of knowledge, other factors—such as drinking status, the gender of the bystander, the gender of the person who flushed, and degree of friendship with the person who flushed—determined how willing a person was to help someone reduce or stop drinking. Class membership was predicted by knowledge, gender, drinking status, and reactions to one’s own flushing. Of these 4 factors, knowledge and reactions to one’s own flushing could be influenced through alcohol education programs. It will take some time for alcohol education to catch up to and change social and cultural patterns of drinking. Meanwhile, motivational

Capturing Physiology of Emotion along Facial Muscles: A Method of Distinguishing Feigned from Involuntary Expressions

Science.gov (United States)

Khan, Masood Mehmood; Ward, Robert D.; Ingleby, Michael

The ability to distinguish feigned from involuntary expressions of emotions could help in the investigation and treatment of neuropsychiatric and affective disorders and in the detection of malingering. This work investigates differences in emotion-specific patterns of thermal variations along the major facial muscles. Using experimental data extracted from 156 images, we attempted to classify patterns of emotion-specific thermal variations into neutral, and voluntary and involuntary expressions of positive and negative emotive states. Initial results suggest (i) each facial muscle exhibits a unique thermal response to various emotive states; (ii) the pattern of thermal variances along the facial muscles may assist in classifying voluntary and involuntary facial expressions; and (iii) facial skin temperature measurements along the major facial muscles may be used in automated emotion assessment.

Anatomical contouring variability in thoracic organs at risk

Energy Technology Data Exchange (ETDEWEB)

McCall, Ross, E-mail: rmccall86@gmail.com [Medical Dosimetry Program, University of Wisconsin, La Crosse, WI (United States); MacLennan, Grayden; Taylor, Matthew; Lenards, Nishele [Medical Dosimetry Program, University of Wisconsin, La Crosse, WI (United States); Nelms, Benjamin E. [Canis Lupus LLC, Madison, WI (United States); Koshy, Matthew; Lemons, Jeffrey [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL (United States); Hunzeker, Ashley [Medical Dosimetry Program, University of Wisconsin, La Crosse, WI (United States)

2016-01-01

The purpose of this study was to determine whether contouring thoracic organs at risk was consistent among medical dosimetrists and to identify how trends in dosimetrist's education and experience affected contouring accuracy. Qualitative and quantitative methods were used to contextualize the raw data that were obtained. A total of 3 different computed tomography (CT) data sets were provided to medical dosimetrists (N = 13) across 5 different institutions. The medical dosimetrists were directed to contour the lungs, heart, spinal cord, and esophagus. The medical dosimetrists were instructed to contour in line with their institutional standards and were allowed to use any contouring tool or technique that they would traditionally use. The contours from each medical dosimetrist were evaluated against “gold standard” contours drawn and validated by 2 radiation oncology physicians. The dosimetrist-derived contours were evaluated against the gold standard using both a Dice coefficient method and a penalty-based metric scoring system. A short survey was also completed by each medical dosimetrist to evaluate their individual contouring experience. There was no significant variation in the contouring consistency of the lungs and spinal cord. Intradosimetrist contouring was consistent for those who contoured the esophagus and heart correctly; however, medical dosimetrists with a poor metric score showed erratic and inconsistent methods of contouring.

Multi-scale graphene patterns on arbitrary substrates via laser-assisted transfer-printing process

KAUST Repository

Park, J. B.

2012-01-01

A laser-assisted transfer-printing process is developed for multi-scale graphene patterns on arbitrary substrates using femtosecond laser scanning on a graphene/metal substrate and transfer techniques without using multi-step patterning processes. The short pulse nature of a femtosecond laser on a graphene/copper sheet enables fabrication of high-resolution graphene patterns. Thanks to the scale up, fast, direct writing, multi-scale with high resolution, and reliable process characteristics, it can be an alternative pathway to the multi-step photolithography methods for printing arbitrary graphene patterns on desired substrates. We also demonstrate transparent strain devices without expensive photomasks and multi-step patterning process. © 2012 American Institute of Physics.

Spectrophotometric analysis of the effectiveness of a novel in-office laser-assisted tooth bleaching method using Er,Cr:YSGG laser.

Science.gov (United States)

Dionysopoulos, Dimitrios; Strakas, Dimitrios; Tolidis, Kosmas; Tsitrou, Effrosyni; Koumpia, Effimia; Koliniotou-Koumpia, Eugenia

2017-11-01

The purpose of this in vitro study was to compare the effectiveness of a novel Er,Cr:YSGG laser-assisted in-office tooth bleaching method with a conventional method by spectrophotometric analysis of the tooth color change. Furthermore, the influence of the application time of the bleaching gel on the effectiveness of the methods and the maintenance of the results 7 days and 1 month after the treatments were also evaluated. Twenty-four bovine incisors were stained and randomly distributed into four groups. Group 1 specimens received an in-office bleaching treatment with 35% H 2 O 2 for 2 × 15 min. Group 2 specimens received the same treatment but with extended application time (2 × 20 min). In Group 3, the same in-office bleaching procedure (2 × 15 min) was carried out as that in Group 1, using Er,Cr:YSGG laser irradiation for 2 × 15 s on each specimen to catalyze the reaction of H 2 O 2 breakdown. Group 4 specimens received the same bleaching treatment as Group 3 but with extended application time (2 × 20 min). Er,Cr:YSGG laser-assisted tooth bleaching treatment is more effective than the conventional treatment regarding color change of the teeth. Application time of the bleaching agent may influence the effectiveness of the methods. The color change of the tested treatments decreases after 7 days and 1 month. The clinical relevance of this study is that this novel laser-assisted bleaching treatment may be more advantageous in color change and application time compared to the conventional bleaching treatment.

Sound-induced facial synkinesis following facial nerve paralysis

NARCIS (Netherlands)

Ma, Ming-San; van der Hoeven, Johannes H.; Nicolai, Jean-Philippe A.; Meek, Marcel F.

Facial synkinesis (or synkinesia) (FS) occurs frequently after paresis or paralysis of the facial nerve and is in most cases due to aberrant regeneration of (branches of) the facial nerve. Patients suffer from inappropriate and involuntary synchronous facial muscle contractions. Here we describe two

Comparison of fiber delivered CO2 laser and electrocautery in transoral robot assisted tongue base surgery.

Science.gov (United States)

Karaman, Murat; Gün, Taylan; Temelkuran, Burak; Aynacı, Engin; Kaya, Cem; Tekin, Ahmet Mahmut

2017-05-01

To compare intra-operative and post-operative effectiveness of fiber delivered CO 2 laser to monopolar electrocautery in robot assisted tongue base surgery. Prospective non-randomized clinical study. Twenty moderate to severe obstructive sleep apnea (OSA) patients, non-compliant with Continuous Positive Airway Pressure (CPAP), underwent Transoral Robotic Surgery (TORS) using the Da Vinci surgical robot in our University Hospital. OSA was treated with monopolar electrocautery in 10 patients, and with flexible CO 2 laser fiber in another 10 patients. The following parameters in the two sets are analyzed: Intraoperative bleeding that required cauterization, robot operating time, need for tracheotomy, postoperative self-limiting bleeding, length of hospitalization, duration until start of oral intake, pre-operative and post-operative minimum arterial oxygen saturation, pre-operative and post-operative Epworth Sleepiness Scale score, postoperative airway complication and postoperative pain. Mean follow-up was 12 months. None of the patients required tracheotomy and there were no intraoperative complications related to the use of the robot or the CO 2 laser. The use of CO 2 laser in TORS-assisted tongue base surgery resulted in less intraoperative bleeding that required cauterization, shorter robot operating time, shorter length of hospitalization, shorter duration until start of oral intake and less postoperative pain, when compared to electrocautery. Postoperative apnea-hypopnea index scores showed better efficacy of CO 2 laser than electrocautery. Comparison of postoperative airway complication rates and Epworth sleepiness scale scores were found to be statistically insignificant between the two groups. The use of CO 2 laser in robot assisted tongue base surgery has various intraoperative and post-operative advantages when compared to monopolar electrocautery.

An improved spatial contour tree constructed method

Science.gov (United States)

Zheng, Yi; Zhang, Ling; Guilbert, Eric; Long, Yi

2018-05-01

Contours are important data to delineate the landform on a map. A contour tree provides an object-oriented description of landforms and can be used to enrich the topological information. The traditional contour tree is used to store topological relationships between contours in a hierarchical structure and allows for the identification of eminences and depressions as sets of nested contours. This research proposes an improved contour tree so-called spatial contour tree that contains not only the topological but also the geometric information. It can be regarded as a terrain skeleton in 3-dimention, and it is established based on the spatial nodes of contours which have the latitude, longitude and elevation information. The spatial contour tree is built by connecting spatial nodes from low to high elevation for a positive landform, and from high to low elevation for a negative landform to form a hierarchical structure. The connection between two spatial nodes can provide the real distance and direction as a Euclidean vector in 3-dimention. In this paper, the construction method is tested in the experiment, and the results are discussed. The proposed hierarchical structure is in 3-demintion and can show the skeleton inside a terrain. The structure, where all nodes have geo-information, can be used to distinguish different landforms and applied for contour generalization with consideration of geographic characteristics.

[The pros and cons of femtosecond laser-assisted cataract surgery].

Science.gov (United States)

Li, Z H; Ye, Z

2016-02-01

Femtosecond laser-assisted cataract surgery (FLACS) is known as an innovative new technology. Compared with traditional surgical approach, FLACS is more accurate, more predictable and less energy used. However, in the current stage of development, there still may be intraoperative and postoperative complications, or even serious complications. FLACS has obvious advantages in certain surgical steps, but there are still clear disadvantages, so it still cannot completely replace the traditional phacoemulsification surgery.

Laser-assisted simultaneous transfer and patterning of vertically aligned carbon nanotube arrays on polymer substrates for flexible devices.

Science.gov (United States)

In, Jung Bin; Lee, Daeho; Fornasiero, Francesco; Noy, Aleksandr; Grigoropoulos, Costas P

2012-09-25

We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet in contact with one another. The absorbed laser heat promotes nanotube adhesion to the polymer in the irradiated regions and enables selective pattern transfer. A combination of the thermal transfer mechanism with rapid direct writing capability of focused laser beam irradiation allows us to achieve simultaneous material transfer and direct micropatterning in a single processing step. Furthermore, we demonstrate that malleability of the nanotube arrays transferred onto a flexible substrate enables post-transfer tailoring of electric conductance by collapsing the aligned nanotubes in different directions. This work suggests that the laser-assisted transfer technique provides an efficient route to using vertically aligned nanotubes as conductive elements in flexible device applications.

Efficacy and safety of Erbium-doped Yttrium Aluminium Garnet fractional resurfacing laser for treatment of facial acne scars

Directory of Open Access Journals (Sweden)

Balakrishnan Nirmal

2013-01-01

Full Text Available Background: Treatment of acne scars with ablative fractional laser resurfacing has given good improvement. But, data on Indian skin are limited. A study comparing qualitative, quantitative, and subjective assessments is also lacking. Aim: Our aim was to assess the improvement of facial acne scars with Erbium-doped Yttrium Aluminium Garnet (Er:YAG 2940 nm fractional laser resurfacing and its adverse effects in 25 patients at a tertiary care teaching hospital. Methods: All 25 patients received four treatment sessions with Er:YAG fractional laser at 1-month interval. The laser parameters were kept constant for each of the four sittings in all patients. Qualitative and quantitative assessments were done using Goodman and Barron grading. Subjective assessment in percentage of improvement was also documented 1 month after each session. Photographs were taken before each treatment session and 1 month after the final session. Two unbiased dermatologists performed independent clinical assessments by comparing the photographs. The kappa statistics was used to monitor the agreement between the dermatologists and patients. Results: Most patients (96% showed atleast fair improvement. Rolling and superficial box scars showed higher significant improvement when compared with ice pick and deep box scars. Patient′s satisfaction of improvement was higher when compared to physician′s observations. No serious adverse effects were noted with exacerbation of acne lesions forming the majority. Conclusion: Ablative fractional photothermolysis is both effective and safe treatment for atrophic acne scars in Indian skin.Precise evaluation of acne scar treatment can be done by taking consistent digital photographs.

[Facial palsy].

Science.gov (United States)

Cavoy, R

2013-09-01

Facial palsy is a daily challenge for the clinicians. Determining whether facial nerve palsy is peripheral or central is a key step in the diagnosis. Central nervous lesions can give facial palsy which may be easily differentiated from peripheral palsy. The next question is the peripheral facial paralysis idiopathic or symptomatic. A good knowledge of anatomy of facial nerve is helpful. A structure approach is given to identify additional features that distinguish symptomatic facial palsy from idiopathic one. The main cause of peripheral facial palsies is idiopathic one, or Bell's palsy, which remains a diagnosis of exclusion. The most common cause of symptomatic peripheral facial palsy is Ramsay-Hunt syndrome. Early identification of symptomatic facial palsy is important because of often worst outcome and different management. The prognosis of Bell's palsy is on the whole favorable and is improved with a prompt tapering course of prednisone. In Ramsay-Hunt syndrome, an antiviral therapy is added along with prednisone. We also discussed of current treatment recommendations. We will review short and long term complications of peripheral facial palsy.

Automatic re-contouring in 4D radiotherapy

International Nuclear Information System (INIS)

Lu, Weiguo; Olivera, Gustavo H; Chen, Quan; Chen, Ming-Li; Ruchala, Kenneth J

2006-01-01

Delineating regions of interest (ROIs) on each phase of four-dimensional (4D) computed tomography (CT) images is an essential step for 4D radiotherapy. The requirement of manual phase-by-phase contouring prohibits the routine use of 4D radiotherapy. This paper develops an automatic re-contouring algorithm that combines techniques of deformable registration and surface construction. ROIs are manually contoured slice-by-slice in the reference phase image. A reference surface is constructed based on these reference contours using a triangulated surface construction technique. The deformable registration technique provides the voxel-to-voxel mapping between the reference phase and the test phase. The vertices of the reference surface are displaced in accordance with the deformation map, resulting in a deformed surface. The new contours are reconstructed by cutting the deformed surface slice-by-slice along the transversal, sagittal or coronal direction. Since both the inputs and outputs of our automatic re-contouring algorithm are contours, it is relatively easy to cope with any treatment planning system. We tested our automatic re-contouring algorithm using a deformable phantom and 4D CT images of six lung cancer patients. The proposed algorithm is validated by visual inspections and quantitative comparisons of the automatic re-contours with both the gold standard segmentations and the manual contours. Based on the automatic delineated ROIs, changes of tumour and sensitive structures during respiration are quantitatively analysed. This algorithm could also be used to re-contour daily images for treatment evaluation and adaptive radiotherapy

Sound-induced facial synkinesis following facial nerve paralysis.

Science.gov (United States)

Ma, Ming-San; van der Hoeven, Johannes H; Nicolai, Jean-Philippe A; Meek, Marcel F

2009-08-01

Facial synkinesis (or synkinesia) (FS) occurs frequently after paresis or paralysis of the facial nerve and is in most cases due to aberrant regeneration of (branches of) the facial nerve. Patients suffer from inappropriate and involuntary synchronous facial muscle contractions. Here we describe two cases of sound-induced facial synkinesis (SFS) after facial nerve injury. As far as we know, this phenomenon has not been described in the English literature before. Patient A presented with right hemifacial palsy after lesion of the facial nerve due to skull base fracture. He reported involuntary muscle activity at the right corner of the mouth, specifically on hearing ringing keys. Patient B suffered from left hemifacial palsy following otitis media and developed involuntary muscle contraction in the facial musculature specifically on hearing clapping hands or a trumpet sound. Both patients were evaluated by means of video, audio and EMG analysis. Possible mechanisms in the pathophysiology of SFS are postulated and therapeutic options are discussed.

Er:YAG laser-assisted hair transplantation in cicatricial alopecia.

Science.gov (United States)

Podda, M; Spieth, K; Kaufmann, R

2000-11-01

Autologous hair transplantation and its combination with flap or reduction procedures is a common surgical approach to cover defects in cicatricial alopecias. Due to the poor recipient conditions present in scar tissue, it is crucial to minimize the trauma exerted on implantation holes in order to achieve good transplantation results. We sought to evaluate the "cold"-ablative properties of the Er:YAG laser for the generation of recipient holes in cicatricial alopecia. Patients with cicatricial alopecia of diverse etiology were treated with Er:YAG laser-assisted hair transplantation. Mini- or micrografts were inserted into recipient holes ablated with a pulse energy of 900-1200 mJ and a spot size of 1.0-1.6 mm. A fluence of 80-120 J/cm2 and 8-12 pulses gave an almost ideal combination of minimal thermal damage and tissue ablation down to the subcutis. With an apparent mini- and micrograft survival of 95% we achieved good cosmetic results after two to five transplant sessions in all patients. The Er:YAG laser is a novel effective tool to ablate recipient holes for autologous hair transplantation in cicatricial alopecia.

Characterization of lysozyme films produced by matrix assisted pulsed laser evaporation (MAPLE)

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Kingshott, Peter

2007-01-01

Thin lysozyme films of thickness up to more than 100 nm have been produced in a dry environment by MAPLE (matrix assisted pulsed laser evaporation) from a water ice matrix. Analysis of the films demonstrates that a significant part of the lysozyme molecules is transferred to the substrate without...

Improvement of laser keyhole formation with the assistance of arc plasma in the hybrid welding process of magnesium alloy

Science.gov (United States)

Liu, Liming; Hao, Xinfeng

2009-11-01

In the previous work, low-power laser/arc hybrid welding technique is used to weld magnesium alloy and high-quality weld joints are obtained. In order to make clear the interactions between low-power laser pulse and arc plasma, the effect of arc plasma on laser pulse is studied in this article. The result shows that the penetration of low-power laser welding with the assistance of TIG arc is more than two times deeper than that of laser welding alone and laser welding transforms from thermal-conduction mode to keyhole mode. The plasma behaviors and spectra during the welding process are studied, and the transition mechanism of laser-welding mode is analyzed in detail. It is also found that with the assistance of arc plasma, the threshold value of average power density to form keyhole welding for YAG laser is only 3.3×10 4 W/cm 2, and the average peak power density is 2.6×10 5 W/cm 2 in the present experiment. Moreover, the distribution of energy density during laser pulse is modulated to improve the formation and stability of laser keyholes.

Significance of the Resonance Condition for Controlling the Seam Position in Laser-assisted TIG Welding

Science.gov (United States)

Emde, B.; Huse, M.; Hermsdorf, J.; Kaierle, S.; Wesling, V.; Overmeyer, L.; Kozakov, R.; Uhrlandt, D.

As an energy-preserving variant of laser hybrid welding, laser-assisted arc welding uses laser powers of less than 1 kW. Recent studies have shown that the electrical conductivity of a TIG welding arc changes within the arc in case of a resonant interaction between laser radiation and argon atoms. This paper presents investigations on how to control the position of the arc root on the workpiece by means of the resonant interaction. Furthermore, the influence on the welding result is demonstrated. The welding tests were carried out on a cooled copper plate and steel samples with resonant and non-resonant laser radiation. Moreover, an analysis of the weld seam is presented.

Characterisation of bacteria by matrix-assisted laser desorption/ionisation and electrospray mass spectrometry

NARCIS (Netherlands)

Baar, B.L.M. van

2000-01-01

Chemical analysis for the characterisation of micro-organisms is rapidly evolving, after the recent advent of new ionisation methods in mass spectrometry (MS): electrospray (ES) and matrix-assisted laser desorption/ionisation (MALDI). These methods allow quick characterisation of micro-organisms,

Facial dynamics and emotional expressions in facial aging treatments.

Science.gov (United States)

Michaud, Thierry; Gassia, Véronique; Belhaouari, Lakhdar

2015-03-01

Facial expressions convey emotions that form the foundation of interpersonal relationships, and many of these emotions promote and regulate our social linkages. Hence, the facial aging symptomatological analysis and the treatment plan must of necessity include knowledge of the facial dynamics and the emotional expressions of the face. This approach aims to more closely meet patients' expectations of natural-looking results, by correcting age-related negative expressions while observing the emotional language of the face. This article will successively describe patients' expectations, the role of facial expressions in relational dynamics, the relationship between facial structures and facial expressions, and the way facial aging mimics negative expressions. Eventually, therapeutic implications for facial aging treatment will be addressed. © 2015 Wiley Periodicals, Inc.

Autologous fat graft and bone marrow-derived mesenchymal stem cells assisted fat graft for treatment of Parry-Romberg syndrome.

Science.gov (United States)

Jianhui, Zhao; Chenggang, Yi; Binglun, Lu; Yan, Han; Li, Yang; Xianjie, Ma; Yingjun, Su; Shuzhong, Guo

2014-09-01

Progressive facial hemiatrophy, also called Parry-Romberg syndrome (PRS), is characterized by slowly progressive atrophy of one side of the face and primarily involves the subcutaneous tissue and fat. The restoration of facial contour and symmetry in patients affected by PRS still remains a challenge clinically. Fat graft is a promising treatment but has some shortcomings, such as unpredictability and low rate of graft survival due to partial necrosis. To obviate these disadvantages, fat graft assisted by bone marrow-derived mesenchymal stem cells (BMSCs) was used to treat PRS patients and the outcome was evaluated in comparison with the conventional treatment by autologous fat graft. Autologous fat graft was harvested by tumescent liposuction. Bone marrow-derived mesenchymal stem cells were then isolated by human Lymphocytes Separation Medium through density gradient centrifugation. Twenty-six patients were treated with autologous fat graft only (group A), whereas 10 other patients were treated with BMSC-assisted fat graft (group B). The Coleman technique was applied in all fat graft injections. The follow-up period was 6 to 12 months in this study, In group A, satisfactory outcome judged by symmetrical appearances was obtained with 1 injection in 12 patients, 2 injections in 8 patients, and 3 injections in 4 patients. However, the result of 1 patient was not satisfactory and 1 patient was overcorrected. In group B, 10 patients obtained satisfactory outcomes and almost reached symmetry by 1 injection. No complications (infection, hematoma, or subcutaneous mass) were observed. The results suggest that BMSC-assisted fat graft is effective and safe for soft tissue augmentation and may be superior to conventional lipoinjection. Additional study is necessary to further evaluate the efficacy of this technique.

Comparison of Cellular Alterations in Fat Cells Harvested With Laser-Assisted Liposuction and Suction-Assisted Liposuction.

Science.gov (United States)

Yildiz, Kemalettin; Taşli, Pakize Neslihan; Şahin, Fikrettin; Güneren, Ethem

2016-05-01

The aim of the present study was to evaluate the viability and proliferative capacity of adipose-derived stem cells obtained by laser-assisted liposuction (LAL). Fat tissue was obtained from 7 male patients treated surgically for gynecomastia. On one side, harvesting was made before LAL, while it was implemented after LAL on the contralateral side. Viability, cell surface antigens, pluripotency, and apoptosis were assessed and compared in these samples. Cells harvested before and after LAL did not exhibit any significant difference in terms of surface cell markers. Number of viable stem cells was lower initially after exposure to laser, while this difference was reversed at the end of 72 hours. Genetic indicators of cellular differentiation were similar in both groups. Apoptosis indicators were increased remarkably after laser exposure in the first 24 hours, but this increase was absent 72 hours after LAL procedure. The authors' results have promising clinical relevance since mesenchymal stem cells harvested during LAL have maintained appropriate cellular features to be used for autologous fat transfer and fat grafting.

[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.

TU-C-17A-03: An Integrated Contour Evaluation Software Tool Using Supervised Pattern Recognition for Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Chen, H; Tan, J; Kavanaugh, J; Dolly, S; Gay, H; Thorstad, W; Anastasio, M; Altman, M; Mutic, S; Li, H [Washington University School of Medicine, Saint Louis, MO (United States)

2014-06-15

Purpose: Radiotherapy (RT) contours delineated either manually or semiautomatically require verification before clinical usage. Manual evaluation is very time consuming. A new integrated software tool using supervised pattern contour recognition was thus developed to facilitate this process. Methods: The contouring tool was developed using an object-oriented programming language C# and application programming interfaces, e.g. visualization toolkit (VTK). The C# language served as the tool design basis. The Accord.Net scientific computing libraries were utilized for the required statistical data processing and pattern recognition, while the VTK was used to build and render 3-D mesh models from critical RT structures in real-time and 360° visualization. Principal component analysis (PCA) was used for system self-updating geometry variations of normal structures based on physician-approved RT contours as a training dataset. The inhouse design of supervised PCA-based contour recognition method was used for automatically evaluating contour normality/abnormality. The function for reporting the contour evaluation results was implemented by using C# and Windows Form Designer. Results: The software input was RT simulation images and RT structures from commercial clinical treatment planning systems. Several abilities were demonstrated: automatic assessment of RT contours, file loading/saving of various modality medical images and RT contours, and generation/visualization of 3-D images and anatomical models. Moreover, it supported the 360° rendering of the RT structures in a multi-slice view, which allows physicians to visually check and edit abnormally contoured structures. Conclusion: This new software integrates the supervised learning framework with image processing and graphical visualization modules for RT contour verification. This tool has great potential for facilitating treatment planning with the assistance of an automatic contour evaluation module in avoiding

Understanding Physiological and Degenerative Natural Vision Mechanisms to Define Contrast and Contour Operators

Science.gov (United States)

Demongeot, Jacques; Fouquet, Yannick; Tayyab, Muhammad; Vuillerme, Nicolas

2009-01-01

Background Dynamical systems like neural networks based on lateral inhibition have a large field of applications in image processing, robotics and morphogenesis modeling. In this paper, we will propose some examples of dynamical flows used in image contrasting and contouring. Methodology First we present the physiological basis of the retina function by showing the role of the lateral inhibition in the optical illusions and pathologic processes generation. Then, based on these biological considerations about the real vision mechanisms, we study an enhancement method for contrasting medical images, using either a discrete neural network approach, or its continuous version, i.e. a non-isotropic diffusion reaction partial differential system. Following this, we introduce other continuous operators based on similar biomimetic approaches: a chemotactic contrasting method, a viability contouring algorithm and an attentional focus operator. Then, we introduce the new notion of mixed potential Hamiltonian flows; we compare it with the watershed method and we use it for contouring. Conclusions We conclude by showing the utility of these biomimetic methods with some examples of application in medical imaging and computed assisted surgery. PMID:19547712

Understanding physiological and degenerative natural vision mechanisms to define contrast and contour operators.

Directory of Open Access Journals (Sweden)

Jacques Demongeot

Full Text Available BACKGROUND: Dynamical systems like neural networks based on lateral inhibition have a large field of applications in image processing, robotics and morphogenesis modeling. In this paper, we will propose some examples of dynamical flows used in image contrasting and contouring. METHODOLOGY: First we present the physiological basis of the retina function by showing the role of the lateral inhibition in the optical illusions and pathologic processes generation. Then, based on these biological considerations about the real vision mechanisms, we study an enhancement method for contrasting medical images, using either a discrete neural network approach, or its continuous version, i.e. a non-isotropic diffusion reaction partial differential system. Following this, we introduce other continuous operators based on similar biomimetic approaches: a chemotactic contrasting method, a viability contouring algorithm and an attentional focus operator. Then, we introduce the new notion of mixed potential Hamiltonian flows; we compare it with the watershed method and we use it for contouring. CONCLUSIONS: We conclude by showing the utility of these biomimetic methods with some examples of application in medical imaging and computed assisted surgery.

Selective tuning of high-Q silicon photonic crystal nanocavities via laser-assisted local oxidation.

Science.gov (United States)

Chen, Charlton J; Zheng, Jiangjun; Gu, Tingyi; McMillan, James F; Yu, Mingbin; Lo, Guo-Qiang; Kwong, Dim-Lee; Wong, Chee Wei

2011-06-20

We examine the cavity resonance tuning of high-Q silicon photonic crystal heterostructures by localized laser-assisted thermal oxidation using a 532 nm continuous wave laser focused to a 2.5 μm radius spot-size. The total shift is consistent with the parabolic rate law. A tuning range of up to 8.7 nm is achieved with ∼ 30 mW laser powers. Over this tuning range, the cavity Qs decreases from 3.2×10(5) to 1.2×10(5). Numerical simulations model the temperature distributions in the silicon photonic crystal membrane and the cavity resonance shift from oxidation.

Electrospray ionization and matrix assisted laser desorption/ionization mass spectrometry: powerful analytical tools in recombinant protein chemistry

DEFF Research Database (Denmark)

Andersen, Jens S.; Svensson, B; Roepstorff, P

1996-01-01

Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy is presen......Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy...... is presented encompassing protein characterization prior to and after cloning of the corresponding gene....

Multiracial Facial Golden Ratio and Evaluation of Facial Appearance.

Directory of Open Access Journals (Sweden)

Mohammad Khursheed Alam

Full Text Available This study aimed to investigate the association of facial proportion and its relation to the golden ratio with the evaluation of facial appearance among Malaysian population. This was a cross-sectional study with 286 randomly selected from Universiti Sains Malaysia (USM Health Campus students (150 females and 136 males; 100 Malaysian Chinese, 100 Malaysian Malay and 86 Malaysian Indian, with the mean age of 21.54 ± 1.56 (Age range, 18-25. Facial indices obtained from direct facial measurements were used for the classification of facial shape into short, ideal and long. A validated structured questionnaire was used to assess subjects' evaluation of their own facial appearance. The mean facial indices of Malaysian Indian (MI, Malaysian Chinese (MC and Malaysian Malay (MM were 1.59 ± 0.19, 1.57 ± 0.25 and 1.54 ± 0.23 respectively. Only MC showed significant sexual dimorphism in facial index (P = 0.047; P<0.05 but no significant difference was found between races. Out of the 286 subjects, 49 (17.1% were of ideal facial shape, 156 (54.5% short and 81 (28.3% long. The facial evaluation questionnaire showed that MC had the lowest satisfaction with mean score of 2.18 ± 0.97 for overall impression and 2.15 ± 1.04 for facial parts, compared to MM and MI, with mean score of 1.80 ± 0.97 and 1.64 ± 0.74 respectively for overall impression; 1.75 ± 0.95 and 1.70 ± 0.83 respectively for facial parts.1 Only 17.1% of Malaysian facial proportion conformed to the golden ratio, with majority of the population having short face (54.5%; 2 Facial index did not depend significantly on races; 3 Significant sexual dimorphism was shown among Malaysian Chinese; 4 All three races are generally satisfied with their own facial appearance; 5 No significant association was found between golden ratio and facial evaluation score among Malaysian population.

Drawing Contour Trees in the Plane.

Science.gov (United States)

Heine, C; Schneider, D; Carr, Hamish; Scheuermann, G

2011-11-01

The contour tree compactly describes scalar field topology. From the viewpoint of graph drawing, it is a tree with attributes at vertices and optionally on edges. Standard tree drawing algorithms emphasize structural properties of the tree and neglect the attributes. Applying known techniques to convey this information proves hard and sometimes even impossible. We present several adaptions of popular graph drawing approaches to the problem of contour tree drawing and evaluate them. We identify five esthetic criteria for drawing contour trees and present a novel algorithm for drawing contour trees in the plane that satisfies four of these criteria. Our implementation is fast and effective for contour tree sizes usually used in interactive systems (around 100 branches) and also produces readable pictures for larger trees, as is shown for an 800 branch example.

Visualizing Contour Trees within Histograms

DEFF Research Database (Denmark)

Kraus, Martin

2010-01-01

Many of the topological features of the isosurfaces of a scalar volume field can be compactly represented by its contour tree. Unfortunately, the contour trees of most real-world volume data sets are too complex to be visualized by dot-and-line diagrams. Therefore, we propose a new visualization...... that is suitable for large contour trees and efficiently conveys the topological structure of the most important isosurface components. This visualization is integrated into a histogram of the volume data; thus, it offers strictly more information than a traditional histogram. We present algorithms...... to automatically compute the graph layout and to calculate appropriate approximations of the contour tree and the surface area of the relevant isosurface components. The benefits of this new visualization are demonstrated with the help of several publicly available volume data sets....

On the Gas Dynamics of Inert-Gas-Assisted Laser Cutting of Steel Plate

Science.gov (United States)

Brandt, A. D.; Settles, G. S.; Scroggs, S. D.

1996-11-01

Laser beam cutting of sheet metal requires an assist gas to blow away the molten material. Since the assist-gas dynamics influences the quality and speed of the cut, the orientation of the gas nozzle with respect to the kerf is also expected to be important. A 1 kW cw CO2 laser with nitrogen assist gas was used to cut mild steel sheet of 1 to 4 mm thickness, using a sonic coaxial nozzle as a baseline. Off-axis nozzles were oriented from 20 deg to 60 deg from normal with exit Mach numbers from 1 to 2.4. Results showed maximum cutting speed at a 40 deg nozzle orientation. Shadowgrams of a geometrically-similar model kerf then revealed a separated shock wave-boundary layer interaction within the kerf for the (untilted) coaxial nozzle case. This was alleviated, resulting in a uniform supersonic flow throughout the kerf and consequent higher cutting speeds, by tilting the nozzle between 20 deg and 45 deg from the normal. This result did not depend upon the exit Mach number of the nozzle. (Research supported by NSF Grant DMI-9400119.)

Rapid selective metal patterning on polydimethylsiloxane (PDMS) fabricated by capillarity-assisted laser direct write

KAUST Repository

Lee, Ming-Tsang; Lee, Daeho; Sherry, Alexander; Grigoropoulos, Costas P

2011-01-01

direct write (LDW) technology. To achieve good metal film quality, a capillarity-assisted laser direct writing (CALDW) of nanoparticle suspensions on a low surface energy material (PDMS) was utilized. Experimental results showed controllable electrical

Laser-Assisted Simultaneous Transfer and Patterning of Vertically Aligned Carbon Nanotube Arrays on Polymer Substrates for Flexible Devices

KAUST Repository

In, Jung Bin

2012-09-25

We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet in contact with one another. The absorbed laser heat promotes nanotube adhesion to the polymer in the irradiated regions and enables selective pattern transfer. A combination of the thermal transfer mechanism with rapid direct writing capability of focused laser beam irradiation allows us to achieve simultaneous material transfer and direct micropatterning in a single processing step. Furthermore, we demonstrate that malleability of the nanotube arrays transferred onto a flexible substrate enables post-transfer tailoring of electric conductance by collapsing the aligned nanotubes in different directions. This work suggests that the laser-assisted transfer technique provides an efficient route to using vertically aligned nanotubes as conductive elements in flexible device applications. © 2012 American Chemical Society.

Orientation-crowding within contours.

Science.gov (United States)

Glen, James C; Dakin, Steven C

2013-07-15

We examined how crowding (the breakdown of object recognition in the periphery caused by interference from "clutter") depends on the global arrangement of target and distracting flanker elements. Specifically we probed orientation discrimination using a near-vertical target Gabor flanked by two vertical distractor Gabors (one above and one below the target). By applying variable (opposite-sign) horizontal offsets to the positions of the two flankers we arranged the elements so that on some trials they formed contours with the target and on others they did not. While the presence of flankers generally elevated orientation discrimination thresholds for the target we observe maximal crowding not when flanker and targets were co-aligned but when a small spatial offset was applied to flanker location, so that contours formed between flanker and targets only when the target orientation was cued. We also report that observers' orientation judgments are biased, with target orientation appearing either attracted or repulsed by the global/contour orientation. A second experiment reveals that the sign of this effect is dependent both on observer and on eccentricity. In general, the magnitude of repulsion is reduced with eccentricity but whether this becomes attraction (of element orientation to contour orientation) is dependent on observer. We note however that across observers and eccentricities, the magnitude of repulsion correlates positively with the amount of release from crowding observed with co-aligned targets and flankers, supporting the notion of fluctuating bias as the basis for elevated crowding within contours.

Laser-assisted delivery of synergistic combination chemotherapy in in vivo skin.

Science.gov (United States)

Wenande, Emily; Tam, Joshua; Bhayana, Brijesh; Schlosser, Steven Kyle; Ishak, Emily; Farinelli, William A; Chlopik, Agata; Hoang, Mai P; Pinkhasov, Omar R; Caravan, Peter; Rox Anderson, R; Haedersdal, Merete

2018-04-10

The effectiveness of topical drugs for treatment of non-melanoma skin cancer is greatly reduced by insufficient penetration to deep skin layers. Ablative fractional lasers (AFLs) are known to enhance topical drug uptake by generating narrow microchannels through the skin, but information on AFL-drug delivery in in vivo conditions is limited. In this study, we examined pharmacokinetics, biodistribution and toxicity of two synergistic chemotherapy agents, cisplatin and 5-fluorouracil (5-FU), following AFL-assisted delivery alone or in combination in in vivo porcine skin. Detected at 0-120 h using mass spectrometry techniques, we demonstrated that fractional CO 2 laser pretreatment (196 microchannels/cm 2 , 852 μm ablation depth) leads to rapid drug uptake in 1500 μm deep skin layers, with a sixfold enhancement in peak cisplatin concentrations versus non-laser-treated controls (5 h, P = 0.005). Similarly, maximum 5-FU deposition was measured within an hour of AFL-delivery, and exceeded peak deposition in non-laser-exposed skin that had undergone topical drug exposure for 5 days. Overall, this accelerated and deeper cutaneous drug uptake resulted in significantly increased inflammatory and histopathological effects. Based on clinical scores and transepidermal water loss measurement, AFL intensified local toxic responses to drugs delivered alone and in combination, while systemic drug exposure remained undetectable. Quantitative histopathologic analyses correspondingly revealed significantly reduced epidermal proliferation and greater cellular apoptosis after AFL-drug delivery; particularly after combined cisplatin + 5-FU exposure. In sum, by overcoming the primary limitation of topical drug penetration and providing accelerated, enhanced and deeper delivery, AFL-assisted combination chemotherapy may represent a promising treatment strategy for non-melanoma skin cancer. Copyright © 2018 Elsevier B.V. All rights reserved.

Nanocomposited coatings produced by laser-assisted process to prevent silicone hydogels from protein fouling and bacterial contamination

International Nuclear Information System (INIS)

Huang, Guobang; Chen, Yi; Zhang, Jin

2016-01-01

Graphical abstract: Nanocomposited-coating was deposited on silicone hydrogel by using the matrix-assisted pulsed laser evaporation (MAPLE) process. The ZnO–PEG nanocomposited coating reduces over 50% protein absorption on silicone hydrogel, and can inhibit the bacterial growth efficiently. - Highlights: • We developed a nanocomposited coating to prevent silicone hydrogel from biofouling. • Matrix-assisted pulsed laser evaporation can deposit inorganic–organic nanomaterials. • The designed nanocomposited coating reduces protein absorption by over 50%. • The designed nanocomposited coating shows significant antimicrobial efficiency. - Abstract: Zinc oxide (ZnO) nanoparticles incorporating with polyethylene glycol (PEG) were deposited together on the surface of silicone hydrogel through matrix-assisted pulsed laser evaporation (MAPLE). In this process, frozen nanocomposites (ZnO–PEG) in isopropanol were irradiated under a pulsed Nd:YAG laser at 532 nm for 1 h. Our results indicate that the MAPLE process is able to maintain the chemical backbone of polymer and prevent the nanocomposite coating from contamination. The ZnO–PEG nanocomposited coating reduces over 50% protein absorption on silicone hydrogel. The cytotoxicity study shows that the ZnO–PEG nanocomposites deposited on silicone hydrogels do not impose the toxic effect on mouse NIH/3T3 cells. In addition, MAPLE-deposited ZnO–PEG nanocomposites can inhibit the bacterial growth significantly.

Multiracial Facial Golden Ratio and Evaluation of Facial Appearance.

Science.gov (United States)

Alam, Mohammad Khursheed; Mohd Noor, Nor Farid; Basri, Rehana; Yew, Tan Fo; Wen, Tay Hui

2015-01-01

This study aimed to investigate the association of facial proportion and its relation to the golden ratio with the evaluation of facial appearance among Malaysian population. This was a cross-sectional study with 286 randomly selected from Universiti Sains Malaysia (USM) Health Campus students (150 females and 136 males; 100 Malaysian Chinese, 100 Malaysian Malay and 86 Malaysian Indian), with the mean age of 21.54 ± 1.56 (Age range, 18-25). Facial indices obtained from direct facial measurements were used for the classification of facial shape into short, ideal and long. A validated structured questionnaire was used to assess subjects' evaluation of their own facial appearance. The mean facial indices of Malaysian Indian (MI), Malaysian Chinese (MC) and Malaysian Malay (MM) were 1.59 ± 0.19, 1.57 ± 0.25 and 1.54 ± 0.23 respectively. Only MC showed significant sexual dimorphism in facial index (P = 0.047; Pmean score of 2.18 ± 0.97 for overall impression and 2.15 ± 1.04 for facial parts, compared to MM and MI, with mean score of 1.80 ± 0.97 and 1.64 ± 0.74 respectively for overall impression; 1.75 ± 0.95 and 1.70 ± 0.83 respectively for facial parts. 1) Only 17.1% of Malaysian facial proportion conformed to the golden ratio, with majority of the population having short face (54.5%); 2) Facial index did not depend significantly on races; 3) Significant sexual dimorphism was shown among Malaysian Chinese; 4) All three races are generally satisfied with their own facial appearance; 5) No significant association was found between golden ratio and facial evaluation score among Malaysian population.

Laser-Assisted Simultaneous Transfer and Patterning of Vertically Aligned Carbon Nanotube Arrays on Polymer Substrates for Flexible Devices

KAUST Repository

In, Jung Bin; Lee, Daeho; Fornasiero, Francesco; Noy, Aleksandr; Grigoropoulos, Costas P.

2012-01-01

We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet

Laser assisted self-pierce riveting of AZ31 magnesium alloy strips

International Nuclear Information System (INIS)

Durandet, Y.; Deam, R.; Beer, A.; Song, W.; Blacket, S.

2010-01-01

Laser assisted self-piercing riveting (LSPR) is a new solid state process that enables low ductility materials to be mechanically joined without cracking. A simple but effective thermal analysis of LSPR is presented that enabled both the absorption of the laser radiation and heat transfer between plies to be determined. The approach was applied to experimental data for LSPR joining of AZ31B-H24 magnesium alloy sheets. It is shown that by using this analytical approach, the temperature at the onset of joining could be estimated and related to observations of joint quality. It was found that crack-free joints were produced at strip temperatures above 200 o C at the time of rivet insertion.

Development of a contour meter

International Nuclear Information System (INIS)

Andrada C, F.A.; Sanz, D.E.

2006-01-01

The dosimetric calculation in patients that receive radiotherapy treatment it requires the one knowledge of the geometry of some anatomical portions, which differs from a patient to another. Making reference to the specific case of mammary neoplasia, one of the measurements that is carried out on the patient is the acquisition of the contour of the breast, which is determined from a point marked on the breastbone until another point marked on the lateral of the thorax, below the armpit, with the patient located in the irradiation position. This measurement is carried out with the help of a mechanical contour meter that is a device conformed by a series of wires with a polymeric coating, which support on the breast of the patient and it reproduces its form. Then it is transported in the more careful possible form on a paper and the contour is traced with a tracer one. The geometric error associated to this procedure is of ±1 cm, which is sensitive of being reduced. The present work finds its motivation in the patient's radiological protection radiotherapy. The maximum error in dose allowed in radiotherapeutic treatments is 5%. It would be increase the precision and with it to optimize the treatment received by the patient, reducing the error in the acquisition process of the mammary contour. With this objective, a digital device is designed whose operation is based in the application of a spatial transformation on a picture of the mammary contour, which corrects the geometric distortion introduced in the process of the photographic acquisition. An algorithm that allows to obtain a front image (without distortion) of the plane of the contour was developed. A software tool especially developed carries out the processing of the digital images. The maximum geometric error detected in the validation process is 2 mm located on a small portion of the contour. (Author)

Laser Resurfacing

OpenAIRE

Janik, Joseph P.; Markus, Jodi L.; Al-Dujaili, Zeena; Markus, Ramsey F.

2007-01-01

In a society desiring images of beauty and youthfulness, the world of cutaneous surgery offers the gifts of facial rejuvenation for those determined to combat the signs of aging. With the development of novel laser and plasma technology, pigmentary changes, scarring, and wrinkles can be conquered providing smoother, healthier, younger-looking skin. This review highlights five of the most popular resurfacing technologies in practice today including the carbon dioxide (CO2) laser, the erbium:yt...

Traumatic facial nerve neuroma with facial palsy presenting in infancy.

Science.gov (United States)

Clark, James H; Burger, Peter C; Boahene, Derek Kofi; Niparko, John K

2010-07-01

To describe the management of traumatic neuroma of the facial nerve in a child and literature review. Sixteen-month-old male subject. Radiological imaging and surgery. Facial nerve function. The patient presented at 16 months with a right facial palsy and was found to have a right facial nerve traumatic neuroma. A transmastoid, middle fossa resection of the right facial nerve lesion was undertaken with a successful facial nerve-to-hypoglossal nerve anastomosis. The facial palsy improved postoperatively. A traumatic neuroma should be considered in an infant who presents with facial palsy, even in the absence of an obvious history of trauma. The treatment of such lesion is complex in any age group but especially in young children. Symptoms, age, lesion size, growth rate, and facial nerve function determine the appropriate management.

Fuzzy model for Laser Assisted Bending Process

Directory of Open Access Journals (Sweden)

Giannini Oliviero

2016-01-01

Full Text Available In the present study, a fuzzy model was developed to predict the residual bending in a conventional metal bending process assisted by a high power diode laser. The study was focused on AA6082T6 aluminium thin sheets. In most dynamic sheet metal forming operations, the highly nonlinear deformation processes cause large amounts of elastic strain energy stored in the formed material. The novel hybrid forming process was thus aimed at inducing the local heating of the mechanically bent workpiece in order to decrease or eliminate the related springback phenomena. In particular, the influence on the extent of springback phenomena of laser process parameters such as source power, scan speed and starting elastic deformation of mechanically bent sheets, was experimentally assessed. Consistent trends in experimental response according to operational parameters were found. Accordingly, 3D process maps of the extent of the springback phenomena according to operational parameters were constructed. The effect of the inherent uncertainties on the predicted residual bending caused by the approximation in the model parameters was evaluated. In particular, a fuzzy-logic based approach was used to describe the model uncertainties and the transformation method was applied to propagate their effect on the residual bending.

Efficacy of Punch Elevation Combined with Fractional Carbon Dioxide Laser Resurfacing in Facial Atrophic Acne Scarring: A Randomized Split-face Clinical Study

Science.gov (United States)

Faghihi, Gita; Nouraei, Saeid; Asilian, Ali; Keyvan, Shima; Abtahi-Naeini, Bahareh; Rakhshanpour, Mehrdad; Nilforoushzadeh, Mohammad Ali; Hosseini, Sayed Mohsen

2015-01-01

Background: A number of treatments for reducing the appearance of acne scars are available, but general guidelines for optimizing acne scar treatment do not exist. The aim of this study was to compare the clinical effectiveness and side effects of fractional carbon dioxide (CO2) laser resurfacing combined with punch elevation with fractional CO2 laser resurfacing alone in the treatment of atrophic acne scars. Materials and Methods: Forty-two Iranian subjects (age range 18–55) with Fitzpatrick skin types III to IV and moderate to severe atrophic acne scars on both cheeks received randomized split-face treatments: One side received fractional CO2 laser treatment and the other received one session of punch elevation combined with two sessions of laser fractional CO2 laser treatment, separated by an interval of 1 month. Two dermatologists independently evaluated improvement in acne scars 4 and 16 weeks after the last treatment. Side effects were also recorded after each treatment. Results: The mean ± SD age of patients was 23.4 ± 2.6 years. Clinical improvement of facial acne scarring was assessed by two dermatologists blinded to treatment conditions. No significant difference in evaluation was observed 1 month after treatment (P = 0.56). Their evaluation found that fractional CO2 laser treatment combined with punch elevation had greater efficacy than that with fractional CO2 laser treatment alone, assessed 4 months after treatment (P = 0.02). Among all side effects, coagulated crust formation and pruritus at day 3 after fractional CO2 laser treatment was significant on both treatment sides (P < 0.05). Conclusion: Concurrent use of fractional laser skin resurfacing with punch elevation offers a safe and effective approach for the treatment of acne scarring. PMID:26538695

Efficacy of punch elevation combined with fractional carbon dioxide laser resurfacing in facial atrophic acne scarring: A randomized split-face clinical study

Directory of Open Access Journals (Sweden)

Gita Faghihi

2015-01-01

Full Text Available Background: A number of treatments for reducing the appearance of acne scars are available, but general guidelines for optimizing acne scar treatment do not exist. The aim of this study was to compare the clinical effectiveness and side effects of fractional carbon dioxide (CO 2 laser resurfacing combined with punch elevation with fractional CO 2 laser resurfacing alone in the treatment of atrophic acne scars. Materials and Methods: Forty-two Iranian subjects (age range 18-55 with Fitzpatrick skin types III to IV and moderate to severe atrophic acne scars on both cheeks received randomized split-face treatments: One side received fractional CO 2 laser treatment and the other received one session of punch elevation combined with two sessions of laser fractional CO 2 laser treatment, separated by an interval of 1 month. Two dermatologists independently evaluated improvement in acne scars 4 and 16 weeks after the last treatment. Side effects were also recorded after each treatment. Results: The mean ± SD age of patients was 23.4 ± 2.6 years. Clinical improvement of facial acne scarring was assessed by two dermatologists blinded to treatment conditions. No significant difference in evaluation was observed 1 month after treatment (P = 0.56. Their evaluation found that fractional CO 2 laser treatment combined with punch elevation had greater efficacy than that with fractional CO 2 laser treatment alone, assessed 4 months after treatment (P = 0.02. Among all side effects, coagulated crust formation and pruritus at day 3 after fractional CO 2 laser treatment was significant on both treatment sides (P < 0.05. Conclusion: Concurrent use of fractional laser skin resurfacing with punch elevation offers a safe and effective approach for the treatment of acne scarring.

The Influence of Different Assist Gases on Ductile Cast Iron Cutting by CO2 Laser

Directory of Open Access Journals (Sweden)

Meško J.

2017-12-01

Full Text Available This article deals with the technology and principles of the laser cutting of ductile cast iron. The properties of the CO2 laser beam, input parameters of the laser cutting, assist gases, the interaction of cut material and the stability of cutting process are described. The commonly used material (nodular cast iron - share of about 25% of all castings on the market and the method of the laser cutting of that material, including the technological parameters that influence the cutting edge, are characterized. Next, the application and use of this method in mechanical engineering practice is described, focusing on fixing and renovation of mechanical components such as removing the inflow gate from castings with the desired quality of the cut, without the further using of the chip machining technology. Experimental samples from the nodular cast iron were created by using different technological parameters of laser cutting. The heat affected zone (HAZ, its width, microstructure and roughness parameter Pt was monitored on the experimental samples (of thickness t = 13 mm. The technological parameters that were varied during the experiments included the type of assist gases (N2 and O2, to be more specific the ratio of gases, and the cutting speed, which ranged from 1.6 m/min to 0.32 m/min. Both parameters were changed until the desired properties were achieved.

Laser cladding assisted by friction stir processing for preparation of deformed crack-free Ni-Cr-Fe coating with nanostructure

Science.gov (United States)

Xie, Siyao; Li, Ruidi; Yuan, Tiechui; Chen, Chao; Zhou, Kechao; Song, Bo; Shi, Yusheng

2018-02-01

Although laser cladding has find its widespread application in surface hardening, this technology has been significantly limited by the solidification crack, which usually initiates along grain boundary due to the brittle precipitation in grain boundary and networks formation during the laser rapid melting/solidification process. This paper proposed a novel laser cladding technology assisted by friction stir processing (FSP) to eliminate the usual metallurgical defects by the thermomechanical coupling effect of FSP with the Ni-Cr-Fe as representative coating material. By the FSP assisted laser cladding, the crack in laser cladding Ni-Cr-Fe coating was eliminated and the coarse networks of laser cladding coating was transformed into dispersed nanoparticles. Moreover, the plastic layers with thicknesses 47-140 μm can be observed, with gradient grain refinement from substrate to the top surface in which grain size reached 300 nm and laser photocoagulation net second phase crushed in the layer. In addition, cracks closed in the plastic zone. The refinement of grain resulted the hardness increased to over 400 HV, much higher than the 300 HV of the laser cladding structure. After FSP, the friction coefficient decreased from 0.6167 to 0.5645 which promoted the wear resistance.

Focusators for laser-branding

Science.gov (United States)

Doskolovich, L. L.; Kazanskiy, N. L.; Kharitonov, S. I.; Uspleniev, G. V.

A new method is investigated for synthesis of computer-generated optical elements: focusators that are able to focus the radial-symmetrical laser beam into complex focal contours, in particular into alphanumeric symbols. The method is based on decomposition of the focal contour into segments of straight lines and semi-circles, following corresponding spacing out of the focusator on elementary segments (concentric rings or sectors) and solution of the inverse task of focusing from focusator segments into corresponding elements of the focal contour. The results of numerical computing of the field from synthesized focusators into the letters are presented. The theoretical efficiency of the focusators discussed is no less than 85%. The amplitude masks and the results of operational studies of synthesized focusators are presented.

Atmospheric pressure plasma-assisted femtosecond laser engraving of aluminium

Science.gov (United States)

Gerhard, Christoph; Gimpel, Thomas; Tasche, Daniel; Koch née Hoffmeister, Jennifer; Brückner, Stephan; Flachenecker, Günter; Wieneke, Stephan; Schade, Wolfgang; Viöl, Wolfgang

2018-05-01

In this contribution, we report on the impact of direct dielectric barrier discharge argon plasma at atmospheric pressure on femtosecond laser engraving of aluminium. It is shown that the assisting plasma strongly affects the surface geometry and formation of spikes of both laser-engraved single lines and patterns of adjacent lines with an appropriate overlap. Further, it was observed that the overall ablation depth is significantly increased in case of large-scale patterning whereas no notable differences in ablation depth are found for single lines. Several possible mechanisms and underlying effects of this behaviour are suggested. The increase in ablation depth is supposed to be due to a plasma-induced removal of debris particles from the cutting point via charging and oxidation as supported by EDX analysis of the re-solidified debris. Furthermore, the impact of a higher degree of surface wrinkling as well as direct interactions of plasma species with the aluminium surface on the ablation process are discussed.

Safe teleoperation based on flexible intraoperative planning for robot-assisted laser microsurgery.

Science.gov (United States)

Mattos, Leonardo S; Caldwell, Darwin G

2012-01-01

This paper describes a new intraoperative planning system created to improve precision and safety in teleoperated laser microsurgeries. It addresses major safety issues related to real-time control of a surgical laser during teleoperated procedures, which are related to the reliability and robustness of the telecommunication channels. Here, a safe solution is presented, consisting in a new planning system architecture that maintains the flexibility and benefits of real-time teleoperation and keeps the surgeon in control of all surgical actions. The developed system is based on our virtual scalpel system for robot-assisted laser microsurgery, and allows the intuitive use of stylus to create surgical plans directly over live video of the surgical field. In this case, surgical plans are defined as graphic objects overlaid on the live video, which can be easily modified or replaced as needed, and which are transmitted to the main surgical system controller for subsequent safe execution. In the process of improving safety, this new planning system also resulted in improved laser aiming precision and improved capability for higher quality laser procedures, both due to the new surgical plan execution module, which allows very fast and precise laser aiming control. Experimental results presented herein show that, in addition to the safety improvements, the new planning system resulted in a 48% improvement in laser aiming precision when compared to the previous virtual scalpel system.

Colesteatoma causando paralisia facial Cholesteatoma causing facial paralysis

Directory of Open Access Journals (Sweden)

José Ricardo Gurgel Testa

2003-10-01

Full Text Available A paralisia facial causada pelo colesteatoma é pouco freqüente. As porções do nervo mais acometidas são a timpânica e a região do 2º joelho. Nos casos de disseminação da lesão colesteatomatosa para o epitímpano anterior, o gânglio geniculado é o segmento do nervo facial mais sujeito à injúria. A etiopatogenia pode estar ligada à compressão do nervo pelo colesteatoma seguida de diminuição do seu suprimento vascular como também pela possível ação de substâncias neurotóxicas produzidas pela matriz do tumor ou pelas bactérias nele contidas. OBJETIVO: Avaliar a incidência, as características clínicas e o tratamento da paralisia facial decorrente da lesão colesteatomatosa. FORMA DE ESTUDO: Clínico retrospectivo. MATERIAL E MÉTODO: Estudo retrospectivo envolvendo dez casos de paralisia facial por colesteatoma selecionados através de levantamento de 206 descompressões do nervo facial com diferentes etiologias, realizadas na UNIFESP-EPM nos últimos dez anos. RESULTADOS: A incidência de paralisia facial por colesteatoma neste estudo foi de 4,85%,com predominância do sexo feminino (60%. A idade média dos pacientes foi de 39 anos. A duração e o grau da paralisia (inicial juntamente com a extensão da lesão foram importantes em relação à recuperação funcional do nervo facial. CONCLUSÃO: O tratamento cirúrgico precoce é fundamental para que ocorra um resultado funcional mais adequado. Nos casos de ruptura ou intensa fibrose do tecido nervoso, o enxerto de nervo (auricular magno/sural e/ou a anastomose hipoglosso-facial podem ser sugeridas.Facial paralysis caused by cholesteatoma is uncommon. The portions most frequently involved are horizontal (tympanic and second genu segments. When cholesteatomas extend over the anterior epitympanic space, the facial nerve is placed in jeopardy in the region of the geniculate ganglion. The aetiology can be related to compression of the nerve followed by impairment of its

A Method for Denoising Image Contours

Directory of Open Access Journals (Sweden)

Ovidiu COSMA

2017-12-01

Full Text Available The edge detection techniques have to compromise between sensitivity and noise. In order for the main contours to be uninterrupted, the level of sensitivity has to be raised, which however has the negative effect of producing a multitude of insignificant contours (noise. This article proposes a method of removing this noise, which acts directly on the binary representation of the image contours.

User-assisted video segmentation system for visual communication

Science.gov (United States)

Wu, Zhengping; Chen, Chun

2002-01-01

Video segmentation plays an important role for efficient storage and transmission in visual communication. In this paper, we introduce a novel video segmentation system using point tracking and contour formation techniques. Inspired by the results from the study of the human visual system, we intend to solve the video segmentation problem into three separate phases: user-assisted feature points selection, feature points' automatic tracking, and contour formation. This splitting relieves the computer of ill-posed automatic segmentation problems, and allows a higher level of flexibility of the method. First, the precise feature points can be found using a combination of user assistance and an eigenvalue-based adjustment. Second, the feature points in the remaining frames are obtained using motion estimation and point refinement. At last, contour formation is used to extract the object, and plus a point insertion process to provide the feature points for next frame's tracking.

Aesthetic facial surgery for the asian male.

Science.gov (United States)

Lam, Samuel M

2005-11-01

Cosmetic surgery of the Asian face has become increasingly popular in the Far East and the West. The Asian male identity has undergone an evolution in Western media toward a more positive change. The standards of beauty have also changed, being defined by more multicultural models and styles of dress than before. To undertake cosmetic surgery of the Asian face, particularly of the Asian male, requires a different psychological understanding of the individual as well as an entirely different surgical technique in most cases. This brief article does not delve into the technical details of each procedure but concentrates on the salient differences in how to approach the Asian male patient for each of the different procedures, including Asian blepharoplasty, augmentation rhinoplasty, lip reduction, dimple fabrication, otoplasty, facial contouring and aging face procedures, and hair restoration.

New software tools for enhanced precision in robot-assisted laser phonomicrosurgery.

Science.gov (United States)

Dagnino, Giulio; Mattos, Leonardo S; Caldwell, Darwin G

2012-01-01

This paper describes a new software package created to enhance precision during robot-assisted laser phonomicrosurgery procedures. The new software is composed of three tools for camera calibration, automatic tumor segmentation, and laser tracking. These were designed and developed to improve the outcome of this demanding microsurgical technique, and were tested herein to produce quantitative performance data. The experimental setup was based on the motorized laser micromanipulator created by Istituto Italiano di Tecnologia and the experimental protocols followed are fully described in this paper. The results show the new tools are robust and effective: The camera calibration tool reduced residual errors (RMSE) to 0.009 ± 0.002 mm under 40× microscope magnification; the automatic tumor segmentation tool resulted in deep lesion segmentations comparable to manual segmentations (RMSE= 0.160 ± 0.028 mm under 40× magnification); and the laser tracker tool proved to be reliable even during cutting procedures (RMSE= 0.073 ± 0.023 mm under 40× magnification). These results demonstrate the new software package can provide excellent improvements to the previous microsurgical system, leading to important enhancements in surgical outcome.

Mandarin-Speaking Children’s Speech Recognition: Developmental Changes in the Influences of Semantic Context and F0 Contours

Directory of Open Access Journals (Sweden)

Hong Zhou

2017-06-01

Full Text Available The goal of this developmental speech perception study was to assess whether and how age group modulated the influences of high-level semantic context and low-level fundamental frequency (F0 contours on the recognition of Mandarin speech by elementary and middle-school-aged children in quiet and interference backgrounds. The results revealed different patterns for semantic and F0 information. One the one hand, age group modulated significantly the use of F0 contours, indicating that elementary school children relied more on natural F0 contours than middle school children during Mandarin speech recognition. On the other hand, there was no significant modulation effect of age group on semantic context, indicating that children of both age groups used semantic context to assist speech recognition to a similar extent. Furthermore, the significant modulation effect of age group on the interaction between F0 contours and semantic context revealed that younger children could not make better use of semantic context in recognizing speech with flat F0 contours compared with natural F0 contours, while older children could benefit from semantic context even when natural F0 contours were altered, thus confirming the important role of F0 contours in Mandarin speech recognition by elementary school children. The developmental changes in the effects of high-level semantic and low-level F0 information on speech recognition might reflect the differences in auditory and cognitive resources associated with processing of the two types of information in speech perception.

Patient-specific reconstruction plates are the missing link in computer-assisted mandibular reconstruction: A showcase for technical description.

Science.gov (United States)

Cornelius, Carl-Peter; Smolka, Wenko; Giessler, Goetz A; Wilde, Frank; Probst, Florian A

2015-06-01

Preoperative planning of mandibular reconstruction has moved from mechanical simulation by dental model casts or stereolithographic models into an almost completely virtual environment. CAD/CAM applications allow a high level of accuracy by providing a custom template-assisted contouring approach for bone flaps. However, the clinical accuracy of CAD reconstruction is limited by the use of prebent reconstruction plates, an analogue step in an otherwise digital workstream. In this paper the integration of computerized, numerically-controlled (CNC) milled, patient-specific mandibular plates (PSMP) within the virtual workflow of computer-assisted mandibular free fibula flap reconstruction is illustrated in a clinical case. Intraoperatively, the bone segments as well as the plate arms showed a very good fit. Postoperative CT imaging demonstrated close approximation of the PSMP and fibular segments, and good alignment of native mandible and fibular segments and intersegmentally. Over a follow-up period of 12 months, there was an uneventful course of healing with good bony consolidation. The virtual design and automated fabrication of patient-specific mandibular reconstruction plates provide the missing link in the virtual workflow of computer-assisted mandibular free fibula flap reconstruction. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Development of a CONTOUR-METER

International Nuclear Information System (INIS)

Andrada Contardi, F.A.

2004-01-01

Dose calculation in patients undergoing radiotherapy treatments requires the knowledge of their anatomical geometry.Making reference to the specific case of breast cancer, one of the measurement that are made on the patients is the acquisition of the breast's contour, determined in an axial plane from a point marked on the breastbone until another point marked on the thorax side under the armpit.This measurement is normally made with a mechanic contour-meter: a device formed by a series of plastic-covered wires designed to be applied on the patient's skin copying the breast contour after it deformation.The geometrical error associated with this procedure is ± 1 cm. The precision of the dose calculation could be increased acquiring a breast contour more accurate.This objective was achieved developing a method based on breast images from a digital camera.The algorithms to obtain an axial-plane image of the contour from digital photographs taken from arbitrary positions were developed.A geometric transformation is applied to the photograph to correct for perspective distortions, obtaining a frontal - undistorted image (axial-plane image).A software tool to make all the image processing was developed under MatLab.The maximum geometrical error detected during the validation of the process was 2 mm [es

Evaporation mechanisms of MgO in laser assisted atom probe tomography

KAUST Repository

Mazumder, Baishakhi

2011-05-01

In this paper the field evaporation properties of bulk MgO and sandwiched MgO layers in Fe are compared using laser assisted Atom Probe Tomography. The comparison of flight time spectra gives an estimate of the evaporation times as a function of the wavelength and the laser energy. It is shown that the evaporation takes place in two steps on two different time scales in MgO. It is also shown that as long as the MgO layer is buried in Fe, the evaporation is dominated by the photon absorption in Fe layer at the tip apex. Eventually the evaporation process of MgO is discussed based on the difference between the bulk materials and the multilayer samples. © 2010 Elsevier B.V.

Evaporation mechanisms of MgO in laser assisted atom probe tomography

KAUST Repository

Mazumder, Baishakhi; Vella, Angela; Dé conihout, Bernard; Al-Kassab, Talaat

2011-01-01

In this paper the field evaporation properties of bulk MgO and sandwiched MgO layers in Fe are compared using laser assisted Atom Probe Tomography. The comparison of flight time spectra gives an estimate of the evaporation times as a function of the wavelength and the laser energy. It is shown that the evaporation takes place in two steps on two different time scales in MgO. It is also shown that as long as the MgO layer is buried in Fe, the evaporation is dominated by the photon absorption in Fe layer at the tip apex. Eventually the evaporation process of MgO is discussed based on the difference between the bulk materials and the multilayer samples. © 2010 Elsevier B.V.

Calibration of matrix-assisted laser desorption/ionization time-of-flight peptide mass fingerprinting spectra

DEFF Research Database (Denmark)

Hjernø, Karin; Højrup, Peter

2007-01-01

This chapter describes a number of aspects important for calibration of matrix-assisted laser desorption/ionization time-of-flight spectra prior to peptide mass fingerprinting searches. Both multipoint internal calibration and mass defect-based calibration is illustrated. The chapter describes ho...

"Blow-torch phenomenon" during laser assisted excision of a thyroglossal cyst at the base of the tongue

Directory of Open Access Journals (Sweden)

Anitha G Bhat

2012-01-01

Full Text Available We report a case of blow-torch phenomenon encountered during diode laser assisted excision of a thyroglossal cyst in a child. This is first such case report from India and highlights an unusual complication which anesthesiologists need to be aware of due to the increasing use of operative laser.

Drawing a different picture with pencil lead as matrix-assisted laser desorption/ionization matrix for fullerene derivatives.

Science.gov (United States)

Nye, Leanne C; Hungerbühler, Hartmut; Drewello, Thomas

2018-02-01

Inspired by reports on the use of pencil lead as a matrix-assisted laser desorption/ionization matrix, paving the way towards matrix-free matrix-assisted laser desorption/ionization, the present investigation evaluates its usage with organic fullerene derivatives. Currently, this class of compounds is best analysed using the electron transfer matrix trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene] malononitrile (DCTB), which was employed as the standard here. The suitability of pencil lead was additionally compared to direct (i.e. no matrix) laser desorption/ionization-mass spectrometry. The use of (DCTB) was identified as the by far gentler method, producing spectra with abundant molecular ion signals and much reduced fragmentation. Analytically, pencil lead was found to be ineffective as a matrix, however, appears to be an extremely easy and inexpensive method for producing sodium and potassium adducts.

Is energy pooling necessary in ultraviolet matrix-assisted laser desorption/ionization?

Science.gov (United States)

Lin, Hou-Yu; Song, Botao; Lu, I-Chung; Hsu, Kuo-Tung; Liao, Chih-Yu; Lee, Yin-Yu; Tseng, Chien-Ming; Lee, Yuan-Tseh; Ni, Chi-Kung

2014-01-15

Energy pooling has been suggested as the key process for generating the primary ions during ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI). In previous studies, decreases in fluorescence quantum yields as laser fluence increased for 2-aminobenzoic acid, 2,5-dihydroxybenzoic acid (2,5-DHB), and 3-hydroxypicolinic acid were used as evidence of energy pooling. This work extends the research to other matrices and addresses whether energy pooling is a universal property in UV-MALDI. Energy pooling was investigated in a time-resolved fluorescence experiment by using a short laser pulse (355 nm, 20 ps pulse width) for excitation and a streak camera (1 ps time resolution) for fluorescence detection. The excited-state lifetime of 2,5-DHB decreased with increases in laser fluence. This suggests that a reaction occurs between two excited molecules, and that energy pooling may be one of the possible reactions. However, the excited-state lifetime of 2,4,6-trihydroxyacetophenone (THAP) did not change with increases in laser fluence. The upper limit of the energy pooling rate constant for THAP is estimated to be approximately 100-500 times smaller than that of 2,5-DHB. The small energy pooling rate constant for THAP indicates that the potential contribution of the energy pooling mechanism to the generation of THAP matrix primary ions should be reconsidered. Copyright © 2013 John Wiley & Sons, Ltd.

Evaluation of Laser-Assisted Trans-Nail Drug Delivery with Optical Coherence Tomography

Directory of Open Access Journals (Sweden)

Meng-Tsan Tsai

2016-12-01

Full Text Available The nail provides a functional protection to the fingertips and surrounding tissue from external injuries. The nail plate consists of three layers including dorsal, intermediate, and ventral layers. The dorsal layer consists of compact, hard keratins, limiting topical drug delivery through the nail. In this study, we investigate the application of fractional CO2 laser that produces arrays of microthermal ablation zones (MAZs to facilitate drug delivery in the nails. We utilized optical coherence tomography (OCT for real-time monitoring of the laser–skin tissue interaction, sparing the patient from an invasive surgical sampling procedure. The time-dependent OCT intensity variance was used to observe drug diffusion through an induced MAZ array. Subsequently, nails were treated with cream and liquid topical drugs to investigate the feasibility and diffusion efficacy of laser-assisted drug delivery. Our results show that fractional CO2 laser improves the effectiveness of topical drug delivery in the nail plate and that OCT could potentially be used for in vivo monitoring of the depth of laser penetration as well as real-time observations of drug delivery.

The role of great auricular-facial nerve neurorrhaphy in facial nerve damage.

Science.gov (United States)

Sun, Yan; Liu, Limei; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo

2015-01-01

Facial nerve is easy to be damaged, and there are many reconstructive methods for facial nerve reconstructive, such as facial nerve end to end anastomosis, the great auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. However, there is still little study about great auricular-facial nerve neurorrhaphy. The aim of the present study was to identify the role of great auricular-facial nerve neurorrhaphy and the mechanism. Rat models of facial nerve cut (FC), facial nerve end to end anastomosis (FF), facial-great auricular neurorrhaphy (FG), and control (Ctrl) were established. Apex nasi amesiality observation, electrophysiology and immunofluorescence assays were employed to investigate the function and mechanism. In apex nasi amesiality observation, it was found apex nasi amesiality of FG group was partly recovered. Additionally, electrophysiology and immunofluorescence assays revealed that facial-great auricular neurorrhaphy could transfer nerve impulse and express AChR which was better than facial nerve cut and worse than facial nerve end to end anastomosis. The present study indicated that great auricular-facial nerve neurorrhaphy is a substantial solution for facial lesion repair, as it is efficiently preventing facial muscles atrophy by generating neurotransmitter like ACh.

Contours - MO 2012 Greene County 5ft Contours (SHP)

Data.gov (United States)

NSGIC State | GIS Inventory — 5ft cartographic contour file for Greene County, Missouri. This file was created using the elevation data from the 2011 LiDAR flight. It includes indexes for 10, 25,...

Medical makeup for concealing facial scars.

Science.gov (United States)

Mee, Donna; Wong, Brian J F

2012-10-01

Surgical, laser, and pharmacological therapies are all used to correct scars and surgical incisions, though have limits with respect to how well facial skin can be restored or enhanced. The use of cosmetics has long been a relevant adjunct to all scar treatment modalities. In recent years, technical advancements in the chemistry and composition of cosmetic products have provided the patient with a broader range of products to employ for concealing scars. This review will provide an overview of contemporary methods for concealing facial scars, birthmarks, and pigmentary changes without the use of traditional/dated, heavy appearing camouflage products. Additionally, general guidelines and information will be provided with respect to identifying competent makeup artists for care of the medical patient. The article by no means is meant to be a tutorial, but rather serves as a starting point in this allied field of medicine. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

In vivo laser assisted end-to-end anastomosis with ICG-infused chitosan patches

Science.gov (United States)

Rossi, Francesca; Matteini, Paolo; Esposito, Giuseppe; Scerrati, Alba; Albanese, Alessio; Puca, Alfredo; Maira, Giulio; Rossi, Giacomo; Pini, Roberto

2011-07-01

Laser assisted vascular repair is a new optimized technique based on the use of ICG-infused chitosan patch to close a vessel wound, with or even without few supporting single stitches. We present an in vivo experimental study on an innovative end-to-end laser assisted vascular anastomotic (LAVA) technique, performed with the application of ICGinfused chitosan patches. The photostability and the mechanical properties of ICG-infused chitosan films were preliminary measured. The in vivo study was performed in 10 New Zealand rabbits. After anesthesia, a 3-cm segment of the right common carotid artery was exposed, thus clamped proximally and distally. The artery was then interrupted by means of a full thickness cut. Three single microsutures were used to approximate the two vessel edges. The ICG-infused chitosan patch was rolled all over the anastomotic site and welded by the use of a diode laser emitting at 810 nm and equipped with a 300 μm diameter optical fiber. Welding was obtained by delivering single laser spots to induce local patch/tissue adhesion. The result was an immediate closure of the anastomosis, with no bleeding at clamps release. Thus animals underwent different follow-up periods, in order to evaluate the welded vessels over time. At follow-up examinations, all the anastomoses were patent and no bleeding signs were documented. Samples of welded vessels underwent histological examinations. Results showed that this technique offer several advantages over conventional suturing methods: simplification of the surgical procedure, shortening of the operative time, better re-endothelization and optimal vascular healing process.

Laser-assisted endoscopic third ventriculostomy: long-term results in a series of 202 patients

NARCIS (Netherlands)

van Beijnum, Janneke; Hanlo, Patrick W.; Fischer, Kathelijn; Majidpour, Mohsen M.; Kortekaas, Marlous F.; Verdaasdonk, Rudolf M.; Vandertop, W. Peter

2008-01-01

OBJECTIVE: Endoscopic third ventriculostomy is a well-known surgical option in the treatment of noncommunicating hydrocephalus. We studied complications and long-term success in 202 patients to demonstrate the safety and efficacy of laser-assisted endoscopic third ventriculostomy (LA-ETV) using a

The minimum amount of "matrix " needed for matrix-assisted pulsed laser deposition of biomolecules

DEFF Research Database (Denmark)

Tabetah, Marshall; Matei, Andreea; Constantinescu, Catalin

2014-01-01

The ability of matrix-assisted pulsed laser evaporation (MAPLE) technique to transfer and deposit high-quality thin organic, bioorganic, and composite films with minimum chemical modification of the target material has been utilized in numerous applications. One of the outstanding problems in MAPLE...

MRI of the facial nerve in idiopathic facial palsy

International Nuclear Information System (INIS)

Saatci, I.; Sahintuerk, F.; Sennaroglu, L.; Boyvat, F.; Guersel, B.; Besim, A.

1996-01-01

The purpose of this prospective study was to define the enhancement pattern of the facial nerve in idiopathic facial paralysis (Bell's palsy) on magnetic resonance (MR) imaging with routine doses of gadolinium-DTPA (0.1 mmol/kg). Using 0.5 T imager, 24 patients were examined with a mean interval time of 13.7 days between the onset of symptoms and the MR examination. Contralateral asymptomatic facial nerves constituted the control group and five of the normal facial nerves (20.8%) showed enhancement confined to the geniculate ganglion. Hence, contrast enhancement limited to the geniculate ganglion in the abnormal facial nerve (3 of 24) was referred to a equivocal. Not encountered in any of the normal facial nerves, enhancement of other segments alone or associated with geniculate ganglion enhancement was considered to be abnormal and noted in 70.8% of the symptomatic facial nerves. The most frequently enhancing segments were the geniculate ganglion and the distal intracanalicular segment. (orig.)

MRI of the facial nerve in idiopathic facial palsy

Energy Technology Data Exchange (ETDEWEB)

Saatci, I. [Dept. of Radiology, Hacettepe Univ., Hospital Sihhiye, Ankara (Turkey); Sahintuerk, F. [Dept. of Radiology, Hacettepe Univ., Hospital Sihhiye, Ankara (Turkey); Sennaroglu, L. [Dept. of Otolaryngology, Head and Neck Surgery, Hacettepe Univ., Hospital Sihhiye, Ankara (Turkey); Boyvat, F. [Dept. of Radiology, Hacettepe Univ., Hospital Sihhiye, Ankara (Turkey); Guersel, B. [Dept. of Otolaryngology, Head and Neck Surgery, Hacettepe Univ., Hospital Sihhiye, Ankara (Turkey); Besim, A. [Dept. of Radiology, Hacettepe Univ., Hospital Sihhiye, Ankara (Turkey)

1996-10-01

The purpose of this prospective study was to define the enhancement pattern of the facial nerve in idiopathic facial paralysis (Bell`s palsy) on magnetic resonance (MR) imaging with routine doses of gadolinium-DTPA (0.1 mmol/kg). Using 0.5 T imager, 24 patients were examined with a mean interval time of 13.7 days between the onset of symptoms and the MR examination. Contralateral asymptomatic facial nerves constituted the control group and five of the normal facial nerves (20.8%) showed enhancement confined to the geniculate ganglion. Hence, contrast enhancement limited to the geniculate ganglion in the abnormal facial nerve (3 of 24) was referred to a equivocal. Not encountered in any of the normal facial nerves, enhancement of other segments alone or associated with geniculate ganglion enhancement was considered to be abnormal and noted in 70.8% of the symptomatic facial nerves. The most frequently enhancing segments were the geniculate ganglion and the distal intracanalicular segment. (orig.)

A laser unit for photodynamic therapy and robot-assisted microsurgery in dentistry

Science.gov (United States)

Chunikhin, A. A.; Bazikyan, E. A.; Pikhtin, N. A.

2017-06-01

Results are presented of photochemical experiments with an IR-laser unit for microsurgery and photodynamic therapy in dentistry. The efficiency of direct generation of singlet oxygen in model organic media in the continuous-wave and pulsed nanosecond modes is examined. The unit can serve both as an independent instrument and as a part of a complex for robot-assisted surgery and dentistry.

Oxygen-assisted multipass cutting of carbon fiber reinforced plastics with ultra-short laser pulses

Energy Technology Data Exchange (ETDEWEB)

Kononenko, T. V.; Komlenok, M. S.; Konov, V. I. [Natural Sciences Center, General Physics Institute, Vavilov str. 38, 119991 Moscow (Russian Federation); National Research Nuclear University, “MEPhI,” Kashirskoye shosse 31, 115409 Moscow (Russian Federation); Freitag, C. [Universität Stuttgart, Institut für Strahlwerkzeuge (IFSW), Pfaffenwaldring 43, 70569 Stuttgart (Germany); GSaME Graduate School of Excellence Advanced Manufacturing Engineering, Nobelstrasse 12, 70569 Stuttgart (Germany); Onuseit, V.; Weber, R.; Graf, T. [Universität Stuttgart, Institut für Strahlwerkzeuge (IFSW), Pfaffenwaldring 43, 70569 Stuttgart (Germany)

2014-03-14

Deep multipass cutting of bidirectional and unidirectional carbon fiber reinforced plastics (CFRP) with picosecond laser pulses was investigated in different static atmospheres as well as with the assistance of an oxygen or nitrogen gas flow. The ablation rate was determined as a function of the kerf depth and the resulting heat affected zone was measured. An assisting oxygen gas flow is found to significantly increase the cutting productivity, but only in deep kerfs where the diminished evaporative ablation due to the reduced laser fluence reaching the bottom of the kerf does not dominate the contribution of reactive etching anymore. Oxygen-supported cutting was shown to also solve the problem that occurs when cutting the CFRP parallel to the fiber orientation where a strong deformation and widening of the kerf, which temporarily slows down the process speed, is revealed to be typical for processing in standard air atmospheres.

Oxygen-assisted multipass cutting of carbon fiber reinforced plastics with ultra-short laser pulses

International Nuclear Information System (INIS)

Kononenko, T. V.; Komlenok, M. S.; Konov, V. I.; Freitag, C.; Onuseit, V.; Weber, R.; Graf, T.

2014-01-01

Deep multipass cutting of bidirectional and unidirectional carbon fiber reinforced plastics (CFRP) with picosecond laser pulses was investigated in different static atmospheres as well as with the assistance of an oxygen or nitrogen gas flow. The ablation rate was determined as a function of the kerf depth and the resulting heat affected zone was measured. An assisting oxygen gas flow is found to significantly increase the cutting productivity, but only in deep kerfs where the diminished evaporative ablation due to the reduced laser fluence reaching the bottom of the kerf does not dominate the contribution of reactive etching anymore. Oxygen-supported cutting was shown to also solve the problem that occurs when cutting the CFRP parallel to the fiber orientation where a strong deformation and widening of the kerf, which temporarily slows down the process speed, is revealed to be typical for processing in standard air atmospheres

Facial paralysis

Science.gov (United States)

... otherwise healthy, facial paralysis is often due to Bell palsy . This is a condition in which the facial ... speech, or occupational therapist. If facial paralysis from Bell palsy lasts for more than 6 to 12 months, ...

Questioning the observation of laser-assisted ionization in fast collisions of He(2 /sup 1,3/S) with He

International Nuclear Information System (INIS)

Gillen, K.T.

1989-01-01

In four recent papers Pradel et al. [Phys. Rev. Lett. 54, 2600 (1985); Phys. Rev. A 35, 1062 (1987)] and Monchicourt et al. [Phys. Rev. A 33, 3515 (1986); Chem. Phys. Lett. 152, 336 (1988)] give arguments claiming the observation of laser-assisted ionization of the short-lived collision complex formed during collisions of He/sup */(2 /sup 1,3/S) with He. However, estimates of the relative sizes of the assisted and unassisted ion signals observed make it very unlikely that laser-assisted ionization has been observed in those experiments. Collisional excitation to higher He/sup */ states, followed by (single-photon) ionization of the excited states, seems a more likely explanation at all energies considered

Laser-assisted lead extraction: the European experience.

Science.gov (United States)

Kennergren, C; Bucknall, C A; Butter, C; Charles, R; Fuhrer, J; Grosfeld, M; Tavernier, R; Morgado, T B; Mortensen, P; Paul, V; Richter, P; Schwartz, T; Wellens, F

2007-08-01

The aim of this study is to investigate the safety and effectiveness of Excimer laser-assisted lead extraction in Europe. The final European multi-centre study experience is presented. The Excimer is a cool cutting laser (50 degrees C) with a wavelength of 308 nm. The energy is emitted from the tip of a flexible sheath and is absorbed by proteins and lipids, 64% of the energy is absorbed at a tissue depth of 0.06 mm. The sheath is positioned over the lead, and the fibrosis surrounding the lead is vaporized while advancing the sheath without damaging other leads. From August 1996 to March 2001, 383 leads (170 atrial, 213 ventricular) in 292 patients (mean age 61.6 years, range 13-96) were extracted at 14 European centres. Mean implantation time was 74 months (3-358). Most frequent indications were pocket infection (26%), non-functional leads (21%), patient morbidity (21%), septicaemia or endocarditis (14%), erosion (5%), and lead interference (8%). Median extraction time was 15 min (1-300). Complete extraction was achieved in 90.9% of the leads and partial extraction in 3.4%. Extraction failed in 5.7% of the leads. Major complications = perforations caused 10/22 (3.4/5.7%) of the failures. Most partially extracted patients were considered clinically successful, as only minor lead parts without clinical significance were left. Femoral non-laser technique was used to remove 8/12 of the non-complication failures. The total complication rate, including five minor complications (1.7%), was 5.1%. No in-hospital mortality occurred. Pacing and implantable cardioverter-defibrillator leads can safely, effectively, and predictably be extracted. Open-heart extractions can be limited to special cases. The results indicate that the traditional policy of abandoning redundant leads, instead of removing them, may be obsolete in many patients.

Influence of laser fluence in ArF-excimer laser assisted crystallisation of a-SiGe:H films

International Nuclear Information System (INIS)

Chiussi, S.; Lopez, E.; Serra, J.; Gonzalez, P.; Serra, C.; Leon, B.; Fabbri, F.; Fornarini, L.; Martelli, S.

2003-01-01

Polycrystalline silicon germanium (poly-SiGe) coatings are drawing increasing attention as active layers in solar cells, bolometers and various microelectronic devices. As a consequence, alternative low-cost production techniques, capable to produce such alloys with uniform and controlled grain size, become more and more attractive. Excimer laser assisted crystallisation, already assessed in thin film transistor production, has proved to be a valuable 'low-thermal budget' technique for the crystallisation of amorphous silicon. Main advantages are the high process quality and reproducibility as well as the possibility of tailoring the grain size in both, small selected regions and large areas. The feasibility of this technique for producing poly-SiGe films has been studied irradiating hydrogenated amorphous SiGe films with spatially uniform ArF-laser pulses of different fluences. Surface morphology, structure and chemical composition have been extensively characterised, demonstrating the need of using a 'step-by-step' process and a careful adjustment of both, total number of shots and laser fluence at each 'step' in order to diminish segregation effects and severe damages of the film surface and of segregation effects

The Use of CAD/CAM Trial Pattern for Facial Prosthesis Fabrication of a Maxillofacial Patient with Large Defect

Directory of Open Access Journals (Sweden)

Nina Ariani

2017-12-01

Full Text Available Treatment of maxillofacial patients needs a multidisciplinary approach of several expertise based on the complexityof the case. Prosthodontists often work together with e.g. ENT, oral or plastic surgeons to provide patient with betterprosthesis and optimum treatment. Case report: A 55 years old male was referred to Dental Teaching Hospital ofUniversitas Indonesia for facial prosthesis fabrication. Patient had undergone squamous cell carcinoma ablationsurgery that encompassed nose, cheek, sinuses, upper lip and most of the hard palate. Due to the extensive natureof the defect, Department of Prosthodontics collaborated with Department of Biomedical Engineering to employ3D printing technique using general purpose machine for fabricating the trial pattern for the prosthesis, withattention given especially to margin areas and facial contours. This technique helps for prosthesis fabrication ofthis patient because manual wax carving is no longer necessary. Wax carving usually is a labor/skill intensive stepand takes longer time. Conclusion: 3D printing of the trial pattern for the prosthesis help minimizes the labor/skill intensive part of facial prosthesis fabrication.

Study of titania nanorod films deposited by matrix-assisted pulsed laser evaporation as a function of laser fluence

Science.gov (United States)

Caricato, A. P.; Belviso, M. R.; Catalano, M.; Cesaria, M.; Cozzoli, P. D.; Luches, A.; Manera, M. G.; Martino, M.; Rella, R.; Taurino, A.

2011-11-01

Chemically synthesized brookite titanium dioxide (TiO2) nanorods with average diameter and length dimensions of 3-4 nm and 35-50 nm, respectively, were deposited by the matrix-assisted pulsed laser evaporation technique. A toluene nanorod solution was frozen at the liquid-nitrogen temperature and irradiated with a KrF excimer laser ( λ=248 nm, τ=20 ns) at the repetition rate of 10 Hz, at different fluences (25 to 350 mJ/cm2). The deposited films were structurally characterized by high-resolution scanning and transmission electron microscopy. single-crystal Si wafers and carbon-coated Cu grids were used as substrates. Structural analyses evidenced the occurrence of brookite-phase crystalline nanospheres coexisting with individually distinguishable TiO2 nanorods in the films deposited at fluences varying from 50 to 350 mJ/cm2. Nanostructured TiO2 films comprising only nanorods were deposited by lowering the laser fluence to 25 mJ/cm2. The observed shape and phase transitions of the nanorods are discussed taking into account the laser-induced heating effects, reduced melting temperature and size-dependent thermodynamic stability of nanoscale TiO2.

The business of refractive laser assisted cataract surgery (ReLACS).

Science.gov (United States)

Berdahl, John P; Jensen, Matthew P

2014-01-01

Refractive Laser Assisted Cataract Surgery (ReLACS) combines the femtosecond laser with other noncovered tests and services in an attempt to reduce spectacle dependence in combination with cataract surgery. Significant interest is present among ophthalmologists who are considering adopting this technology, however significant capital outlays and continuing expenses can make the decision to adopt ReLACS foreboding. We review the financial considerations of ReLACS and review the trends seen in early adopters of this technology. Recent findings have shown that ReLACS is a growing segment of cataract surgery. Most practices who have implemented the technology have broken even and have a positive outlook on the financial return of implementing the ReLACS program. The average break-even analysis point for practices is around 230 cases a year. ReLACS is growing and appears to be a financial viable approach for many practices.

Facial Sports Injuries

Science.gov (United States)

... Marketplace Find an ENT Doctor Near You Facial Sports Injuries Facial Sports Injuries Patient Health Information News ... should receive immediate medical attention. Prevention Of Facial Sports Injuries The best way to treat facial sports ...

Facial Cosmetic Surgery

Science.gov (United States)

... to find out more. Facial Cosmetic Surgery Facial Cosmetic Surgery Extensive education and training in surgical procedures ... to find out more. Facial Cosmetic Surgery Facial Cosmetic Surgery Extensive education and training in surgical procedures ...

Layered double hydroxides/polymer thin films grown by matrix assisted pulsed laser evaporation

Energy Technology Data Exchange (ETDEWEB)

Birjega, R.; Matei, A.; Mitu, B.; Ionita, M.D.; Filipescu, M.; Stokker-Cheregi, F.; Luculescu, C.; Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., 77125 Bucharest–Magurele (Romania); Zavoianu, R.; Pavel, O.D. [University of Bucharest, Faculty of Chemistry, Department of Chemical Technology and Catalysis, 4-12 Regina Elisabeta Bd., Bucharest (Romania); Corobea, M.C. [National R. and S. Institute for Chemistry and Petrochemistry, ICECHIM, 202 Splaiul Independentei Str., CP-35-274, 060021, Bucharest (Romania)

2013-09-30

Due to their highly tunable properties, layered double hydroxides (LDHs) are an emerging class of the favorably layered crystals used for the preparation of multifunctional polymer/layered crystal nanocomposites. In contrast to cationic clay materials with negatively charge layers, LDHs are the only host lattices with positively charged layers (brucite-like), with interlayer exchangeable anions and intercalated water. In this work, the deposition of thin films of Mg and Al based LDH/polymers nanocomposites by laser techniques is reported. Matrix assisted pulsed laser evaporation was the method used for thin films deposition. The Mg–Al LDHs capability to act as a host for polymers and to produce hybrid LDH/polymer films has been investigated. Polyethylene glycol with different molecular mass compositions and ethylene glycol were used as polymers. The structure and surface morphology of the deposited LDH/polymers films were examined by X-ray diffraction, Fourier transform infra-red spectroscopy, atomic force microscopy and scanning electron microscopy. - Highlights: • Hybrid composites deposited by matrix assisted pulsed laser evaporation (MAPLE). • Mg–Al layered double hydroxides (LDH) and polyethylene glycol (PEG) are used. • Mixtures of PEG1450 and LDH were deposited by MAPLE. • Deposited thin films preserve the properties of the starting material. • The film wettability can be controlled by the amount of PEG.

A systematic review of filler agents for aesthetic treatment of HIV facial lipoatrophy (FLA).

Science.gov (United States)

Jagdeo, Jared; Ho, Derek; Lo, Alex; Carruthers, Alastair

2015-12-01

HIV facial lipoatrophy (FLA) is characterized by facial volume loss. HIV FLA affects the facial contours of the cheeks, temples, and orbits, and is associated with social stigma. Although new highly active antiretroviral therapy medications are associated with less severe FLA, the prevalence of HIV FLA among treated individuals exceeds 50%. The goal of our systematic review is to examine published clinical studies involving the use of filler agents for aesthetic treatment of HIV FLA and to provide evidence-based recommendations based on published efficacy and safety data. A systematic review of the published literature was performed on July 1, 2015, on filler agents for aesthetic treatment of HIV FLA. Based on published studies, poly-L-lactic acid is the only filler agent with grade of recommendation: B. Other reviewed filler agents received grade of recommendation: C or D. Poly-L-lactic acid may be best for treatment over temples and cheeks, whereas calcium hydroxylapatite, with a Food and Drug Administration indication of subdermal implantation, may be best used deeply over bone for focal enhancement. Additional long-term randomized controlled trials are necessary to elucidate the advantages and disadvantages of fillers that have different biophysical properties, in conjunction with cost-effectiveness analysis, for treatment of HIV FLA. Published by Elsevier Inc.

Performance Improvement of Microcrystalline p-SiC/i-Si/n-Si Thin Film Solar Cells by Using Laser-Assisted Plasma Enhanced Chemical Vapor Deposition

Directory of Open Access Journals (Sweden)

Hsin-Ying Lee

2014-01-01

Full Text Available The microcrystalline p-SiC/i-Si/n-Si thin film solar cells treated with hydrogen plasma were fabricated at low temperature using a CO2 laser-assisted plasma enhanced chemical vapor deposition (LAPECVD system. According to the micro-Raman results, the i-Si films shifted from 482 cm−1 to 512 cm−1 as the assisting laser power increased from 0 W to 80 W, which indicated a gradual transformation from amorphous to crystalline Si. From X-ray diffraction (XRD results, the microcrystalline i-Si films with (111, (220, and (311 diffraction were obtained. Compared with the Si-based thin film solar cells deposited without laser assistance, the short-circuit current density and the power conversion efficiency of the solar cells with assisting laser power of 80 W were improved from 14.38 mA/cm2 to 18.16 mA/cm2 and from 6.89% to 8.58%, respectively.

A vision-based system for fast and accurate laser scanning in robot-assisted phonomicrosurgery.

Science.gov (United States)

Dagnino, Giulio; Mattos, Leonardo S; Caldwell, Darwin G

2015-02-01

Surgical quality in phonomicrosurgery can be improved by open-loop laser control (e.g., high-speed scanning capabilities) with a robust and accurate closed-loop visual servoing systems. A new vision-based system for laser scanning control during robot-assisted phonomicrosurgery was developed and tested. Laser scanning was accomplished with a dual control strategy, which adds a vision-based trajectory correction phase to a fast open-loop laser controller. The system is designed to eliminate open-loop aiming errors caused by system calibration limitations and by the unpredictable topology of real targets. Evaluation of the new system was performed using CO(2) laser cutting trials on artificial targets and ex-vivo tissue. This system produced accuracy values corresponding to pixel resolution even when smoke created by the laser-target interaction clutters the camera view. In realistic test scenarios, trajectory following RMS errors were reduced by almost 80 % with respect to open-loop system performances, reaching mean error values around 30 μ m and maximum observed errors in the order of 60 μ m. A new vision-based laser microsurgical control system was shown to be effective and promising with significant positive potential impact on the safety and quality of laser microsurgeries.

Graphene synthesis by laser-assisted chemical vapor deposition on Ni plate and the effect of process parameters on uniform graphene growth

International Nuclear Information System (INIS)

Jiang, Juan; Lin, Zhe; Ye, Xiaohui; Zhong, Minlin; Huang, Ting; Zhu, Hongwei

2014-01-01

A fast, simple technique was developed to fabricate few-layer graphene films at ambient pressure and room temperature by laser-assisted chemical vapor deposition on polycrystalline Ni plates. Laser scanning speed was found as the most important factor in the production of few-layer graphene. The quality of graphene films was controlled by varying the laser power. Uniform graphene ribbons with a width of 1.5 mm and a length of 16 mm were obtained at a scanning speed of 1.3 mm/s and a laser power of 600 W. The developed technique provided a promising application of a high-power laser system to fabricate a graphene film. - Highlights: • Uniform few-layer graphene was fabricated at room temperature and ambient conditions. • Laser-assisted chemical vapor deposition was used to grow the layers in a few seconds. • The effect of process parameters on graphene growth was discussed. • This cost effective method could facilitate the integration of graphene in electronic devices

Facial Fractures.

Science.gov (United States)

Ricketts, Sophie; Gill, Hameet S; Fialkov, Jeffery A; Matic, Damir B; Antonyshyn, Oleh M

2016-02-01

After reading this article, the participant should be able to: 1. Demonstrate an understanding of some of the changes in aspects of facial fracture management. 2. Assess a patient presenting with facial fractures. 3. Understand indications and timing of surgery. 4. Recognize exposures of the craniomaxillofacial skeleton. 5. Identify methods for repair of typical facial fracture patterns. 6. Discuss the common complications seen with facial fractures. Restoration of the facial skeleton and associated soft tissues after trauma involves accurate clinical and radiologic assessment to effectively plan a management approach for these injuries. When surgical intervention is necessary, timing, exposure, sequencing, and execution of repair are all integral to achieving the best long-term outcomes for these patients.

Pancreatic gross tumor volume contouring on computed tomography (CT) compared with magnetic resonance imaging (MRI): Results of an international contouring conference.

Science.gov (United States)

Hall, William A; Heerkens, Hanne D; Paulson, Eric S; Meijer, Gert J; Kotte, Alexis N; Knechtges, Paul; Parikh, Parag J; Bassetti, Michael F; Lee, Percy; Aitken, Katharine L; Palta, Manisha; Myrehaug, Sten; Koay, Eugene J; Portelance, Lorraine; Ben-Josef, Edgar; Erickson, Beth A

Accurate identification of the gross tumor volume (GTV) in pancreatic adenocarcinoma is challenging. We sought to understand differences in GTV delineation using pancreatic computed tomography (CT) compared with magnetic resonance imaging (MRI). Twelve attending radiation oncologists were convened for an international contouring symposium. All participants had a clinical and research interest in pancreatic adenocarcinoma. CT and MRI scans from 3 pancreatic cases were used for contouring. CT and MRI GTVs were analyzed and compared. Interobserver variability was compared using Dice's similarity coefficient (DSC), Hausdorff distances, and Jaccard indices. Mann-Whitney tests were used to check for significant differences. Consensus contours on CT and MRI scans and constructed count maps were used to visualize the agreement. Agreement regarding the optimal method to determine GTV definition using MRI was reached. Six contour sets (3 from CT and 3 from MRI) were obtained and compared for each observer, totaling 72 contour sets. The mean volume of contours on CT was significantly larger at 57.48 mL compared with a mean of 45.76 mL on MRI, P = .011. The standard deviation obtained from the CT contours was significantly larger than the standard deviation from the MRI contours (P = .027). The mean DSC was 0.73 for the CT and 0.72 for the MRI (P = .889). The conformity index measurement was similar for CT and MRI (P = .58). Count maps were created to highlight differences in the contours from CT and MRI. Using MRI as a primary image set to define a pancreatic adenocarcinoma GTV resulted in smaller contours compared with CT. No differences in DSC or the conformity index were seen between MRI and CT. A stepwise method is recommended as an approach to contour a pancreatic GTV using MRI. Copyright © 2017 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

One-Stage Treatment for Adult Patients With Crouzonoid Appearance by Orthognathic and Face Contouring Surgery.

Science.gov (United States)

Kim, Byung Jun; Bae, Hahn Sol; Lee, Yoonho

2017-07-01

Crouzon syndrome is a rare genetic disorder with autosomal-dominant inheritance that shows a triad of hallmark characteristics: craniosynostosis, exophthalmos, and midface retrusion. General treatment protocol for patients with Crouzon syndrome has already been established, but there is no standard treatment strategy for adult patients with Crouzonoid appearance. The authors present clinical patients of 1-stage orthognathic and face contouring surgery to achieve functional and aesthetic improvement.One-stage surgery was performed in adult patients with Crouzonoid appearance without a history of facial surgery. Orthognathic 2-jaw surgery was first performed to treat class III malocclusion. Face contouring surgery was conducted next to improve the aesthetic appearance using midface augmentation with onlay rib bone graft, advancement genioplasty, augmentation rhinoplasty, and ancillary procedures such as neck lift, fat graft, or fillers.Five patients (2 men, 3 women) were enrolled in this study. The mean age at the time of surgery was 19.0 years. No specific surgery-related complications such as infection, nerve injury, or recurred malocclusion were observed during the 3.5 years of follow-up. Normal class I occlusion was reached in all patients. The frontonasal angle, nasolabial angle, and labiomental angle improved from 125.1° to 135.1° (P > 0.05), 60.9° to 86.3° (P = 0.018), and 146.3° to 125.0° (P = 0.018), respectively. The Global Aesthetic Improvement Scale score was 4.75 and 5.00 in frontal and profile views, respectively.One-stage orthognathic and face contouring surgery may be an effective surgical option with good postoperative functional and aesthetic improvement in adult patients with Crouzonoid appearance.

Laparoscopy-assisted micropercutaneous choledocholithotripsy with holmium laser in a cholecystectomized patient: an initial report.

Science.gov (United States)

Gökçen, Kaan; Atabey, Mustafa; Gökçen, Pınar; Gökçe, Gökhan

2017-12-01

We present a novel minimally invasive technique, laparoscopy-assisted micropercutaneous choledocholithotripsy, for choledocholithiasis that cannot be treated with other endoscopic techniques. This technique includes standard laparoscopic exploration of the common bile duct, combined with an all-seeing needle and holmium laser lithotripsy. As is known, an all-seeing needle is used in micropercutaneous nephrolithotomy for middle-sized renal stones. In this technique, an all-seeing needle was inserted into the dilatated common bile duct under laparoscopic vision and then a lithotripsy procedure was performed with a holmium laser behind the biliary stent. A cholecystectomized female patient with a 21-mm stone in the common bile duct who previously underwent an unsuccessful endoscopic retrograde cholangiopancreatography procedure was operated on in our service with laparoscopy-assisted micropercutaneous choledocholithotomy without a T-tube. This novel procedure was completed uneventfully and the patient was discharged without any complications. In the future, this procedure will hopefully be a treatment modality in choledocholithiasis that cannot be treated by other minimally invasive techniques.

The Prevalence of Cosmetic Facial Plastic Procedures among Facial Plastic Surgeons.

Science.gov (United States)

Moayer, Roxana; Sand, Jordan P; Han, Albert; Nabili, Vishad; Keller, Gregory S

2018-04-01

This is the first study to report on the prevalence of cosmetic facial plastic surgery use among facial plastic surgeons. The aim of this study is to determine the frequency with which facial plastic surgeons have cosmetic procedures themselves. A secondary aim is to determine whether trends in usage of cosmetic facial procedures among facial plastic surgeons are similar to that of nonsurgeons. The study design was an anonymous, five-question, Internet survey distributed via email set in a single academic institution. Board-certified members of the American Academy of Facial Plastic and Reconstructive Surgery (AAFPRS) were included in this study. Self-reported history of cosmetic facial plastic surgery or minimally invasive procedures were recorded. The survey also queried participants for demographic data. A total of 216 members of the AAFPRS responded to the questionnaire. Ninety percent of respondents were male ( n  = 192) and 10.3% were female ( n  = 22). Thirty-three percent of respondents were aged 31 to 40 years ( n  = 70), 25% were aged 41 to 50 years ( n  = 53), 21.4% were aged 51 to 60 years ( n  = 46), and 20.5% were older than 60 years ( n  = 44). Thirty-six percent of respondents had a surgical cosmetic facial procedure and 75% has at least one minimally invasive cosmetic facial procedure. Facial plastic surgeons are frequent users of cosmetic facial plastic surgery. This finding may be due to access, knowledge base, values, or attitudes. By better understanding surgeon attitudes toward facial plastic surgery, we can improve communication with patients and delivery of care. This study is a first step in understanding use of facial plastic procedures among facial plastic surgeons. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Video-Assisted Laser Resection of Lung Metastases-Feasibility of a New Surgical Technique.

Science.gov (United States)

Meyer, Christian; Bartsch, Detlef; Mirow, Nikolas; Kirschbaum, Andreas

2017-08-01

Background  Our pilot study describes our initial experience to do a laser resection of lung metastases under video-assisted thoracoscopic control via a minithoracotomy. With this approach, if needed, mediastinal lymphadenectomy is also possible. Methods  In this study, 15 patients (11 men and 4 women, mean age: 60 years) with resectable lung metastases of different solid primary tumors (colorectal cancer in seven patients, melanoma in three patients, renal cell carcinoma in two patients, and one each with oropharyngeal cancer, breast cancer, and seminoma) were included. An anterior minithoracotomy incision (approximately 5-7 cm length) was created in the fifth intercostal space and a soft tissue retractor (Alexis Protector; Applied Medical) was positioned. Two additional working ports were inserted. The entire lung was palpated via the minithoracotomy. All detected lung metastases were removed under thoracoscopic control. Nonanatomic resections were performed using a diode-pumped neodymium-doped yttrium aluminium garnet laser (LIMAX120; KLS Martin GmbH & Co KG) with a laser power of 80 W in a noncontact modus. Deeper parenchymal lesions were sutured. Results  A total of 29 lung metastases up to 30 mm in size were resected and all metastases diagnosed on preoperative imaging were detected. All diagnosed lung metastases were completely resected (R0). The median operation time was 102 (range: 85-120) minutes. Median blood loss was 47.6 mL and no postoperative complications occurred. Neither local recurrences nor new lung metastases were observed within 6 months after the procedures. Conclusion  Video-assisted laser resection of lung metastases is safe, effective, and fulfills the requirements of modern lung metastases surgery. Georg Thieme Verlag KG Stuttgart · New York.

Lubricant depletion under various laser heating conditions in Heat Assisted Magnetic Recording (HAMR)

Science.gov (United States)

Xiong, Shaomin; Wu, Haoyu; Bogy, David

2014-09-01

Heat assisted magnetic recording (HAMR) is expected to increase the storage areal density to more than 1 Tb/in2 in hard disk drives (HDDs). In this technology, a laser is used to heat the magnetic media to the Curie point (~400-600 °C) during the writing process. The lubricant on the top of a magnetic disk could evaporate and be depleted under the laser heating. The change of the lubricant can lead to instability of the flying slider and failure of the head-disk interface (HDI). In this study, a HAMR test stage is developed to study the lubricant thermal behavior. Various heating conditions are controlled for the study of the lubricant thermal depletion. The effects of laser heating repetitions and power levels on the lubricant depletion are investigated experimentally. The lubricant reflow behavior is discussed as well.

Characterization of ethylcellulose and hydroxypropyl methylcellulose thin films deposited by matrix-assisted pulsed laser evaporation

Energy Technology Data Exchange (ETDEWEB)

Palla-Papavlu, A., E-mail: apalla@nipne.ro [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania); Rusen, L.; Dinca, V.; Filipescu, M. [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania); Lippert, T. [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen PSI (Switzerland); Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania)

2014-05-01

In this study is reported the deposition of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC) by matrix-assisted pulsed laser evaporation (MAPLE). Both HPMC and EC were deposited on silicon substrates using a Nd:YAG laser (266 nm, 5 ns laser pulse and 10 Hz repetition rate) and then characterized by atomic force microscopy and Fourier transform infrared spectroscopy. It was found that for laser fluences up to 450 mJ/cm{sup 2} the structure of the deposited HPMC and EC polymer in the thin film resembles to the bulk. Morphological investigations reveal island features on the surface of the EC thin films, and pores onto the HPMC polymer films. The obtained results indicate that MAPLE may be an alternative technique for the fabrication of new systems with desired drug release profile.

Characterization of ethylcellulose and hydroxypropyl methylcellulose thin films deposited by matrix-assisted pulsed laser evaporation

Science.gov (United States)

Palla-Papavlu, A.; Rusen, L.; Dinca, V.; Filipescu, M.; Lippert, T.; Dinescu, M.

2014-05-01

In this study is reported the deposition of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC) by matrix-assisted pulsed laser evaporation (MAPLE). Both HPMC and EC were deposited on silicon substrates using a Nd:YAG laser (266 nm, 5 ns laser pulse and 10 Hz repetition rate) and then characterized by atomic force microscopy and Fourier transform infrared spectroscopy. It was found that for laser fluences up to 450 mJ/cm2 the structure of the deposited HPMC and EC polymer in the thin film resembles to the bulk. Morphological investigations reveal island features on the surface of the EC thin films, and pores onto the HPMC polymer films. The obtained results indicate that MAPLE may be an alternative technique for the fabrication of new systems with desired drug release profile.

Reproducibility of the dynamics of facial expressions in unilateral facial palsy.

Science.gov (United States)

Alagha, M A; Ju, X; Morley, S; Ayoub, A

2018-02-01

The aim of this study was to assess the reproducibility of non-verbal facial expressions in unilateral facial paralysis using dynamic four-dimensional (4D) imaging. The Di4D system was used to record five facial expressions of 20 adult patients. The system captured 60 three-dimensional (3D) images per second; each facial expression took 3-4seconds which was recorded in real time. Thus a set of 180 3D facial images was generated for each expression. The procedure was repeated after 30min to assess the reproducibility of the expressions. A mathematical facial mesh consisting of thousands of quasi-point 'vertices' was conformed to the face in order to determine the morphological characteristics in a comprehensive manner. The vertices were tracked throughout the sequence of the 180 images. Five key 3D facial frames from each sequence of images were analyzed. Comparisons were made between the first and second capture of each facial expression to assess the reproducibility of facial movements. Corresponding images were aligned using partial Procrustes analysis, and the root mean square distance between them was calculated and analyzed statistically (paired Student t-test, PFacial expressions of lip purse, cheek puff, and raising of eyebrows were reproducible. Facial expressions of maximum smile and forceful eye closure were not reproducible. The limited coordination of various groups of facial muscles contributed to the lack of reproducibility of these facial expressions. 4D imaging is a useful clinical tool for the assessment of facial expressions. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Fractional laser-assisted drug uptake

DEFF Research Database (Denmark)

Banzhaf, Christina A; Thaysen-Petersen, Daniel; Bay, Christiane

2017-01-01

BACKGROUND AND OBJECTIVE: Ablative fractional laser (AFXL) is acknowledged to increase uptake of topically applied agents in skin. AFXL channels gradually close over time, which may impair this capability. The time frame for applying a drug after AFXL exposure remains to be established. The aim...... in laser-exposed and non-laser-exposed skin at 24-48 hours. CONCLUSIONS: The time frame to maintain enhanced drug delivery sustained for several hours after AFXL exposure, corresponding to channel morphology and loss of skin integrity. Lasers Surg. Med. 49:348-354, 2017. © 2016 Wiley Periodicals, Inc....

Autologous fat transplantation for depressed linear scleroderma-induced facial atrophic scars.

Science.gov (United States)

Roh, Mi Ryung; Jung, Jin Young; Chung, Kee Yang

2008-12-01

Facial linear scleroderma results in depressed atrophic scars. Autologous fat transplantation has been widely used, and fat appears to be an ideal material for filling depressed atrophic scars and contour deformities, but long-term results for autologous fat transplantation are controversial. To review the short- and long-term results of 20 patients who underwent multiple autologous fat transplantations for depressed atrophic scar correction. Twenty patients with clinically inactive facial linear scleroderma were included. They received at least two transplantations and had a 12-month follow-up evaluation. On the forehead, 51% to 75% improvement (average grading scale: 2.4) was achieved when observed at least 12 months after the last treatment. For the chin, correction was poor (average grading scale: 0.7) with less than 25% improvement. The infraorbital area showed fair correction, but the nose showed poor correction. Two of three patients with scalp reduction surgery showed excellent results, showing only slight scar widening. Autologous fat transplantation is an effective method for long-term correction of depressed atrophic scars left by linear scleroderma on the forehead but is less effective for corrections on the nose, infraorbital area, and chin.

Ventajas de la cicatrización cutánea asistida por láser (LASH Advantages of laser assisted scar healing (LASH

Directory of Open Access Journals (Sweden)

S. Mordon

2011-12-01

Full Text Available La fase final de toda cirugía es la sutura y su cicatriz correspondiente y, frecuentemente, ésta es la única secuela visible de una intervención. La técnica LASH (cicatrización cutánea asistida por láser, estimula los mecanismos de reparación de la piel por efecto térmico, condicionando la calidad de la cicatrización. Estudios experimentales en ratones comparando los resultados obtenidos en heridas quirúrgicas radiadas con laser diodo 810 nm tras ser suturadas, con los obtenidos en igual tipo de heridas suturadas de manera convencional, han demostrado que se consiguen cicatrices mucho menos visibles cuando se practica el tratamiento con láser. La histología confirma, comparativamente, una notable aceleración del proceso cicatricial con modificación del TGFβ (Transforming Growth Factor-Beta directamente implicado en la reparación tisular, en los animales en los que la sutura fue asistida por láser. Igualmente, el análisis tensiométrico demostró mayor resistencia a la acción de estiramiento mecánico en estas heridas. Estudios clínicos en pacientes sometidos a dermolipectomia, reducción mamaria y estiramiento facial, demuestran que al tratar con LASH una parte o una de las líneas de sutura, los análisis realizados tanto por los pacientes como por cirujanos independientes a los 8 días, 3 meses y un año, evidencian resultados más favorables para la técnica láser, Las dosis eficaces determinadas para las fluencias láser están entre 80 y 120 J/cm². La técnica LASH es simple de efectuar, reproducible, rápida y ofrece una clara evidencia de que es posible reducir considerablemente la cicatriz, logrando que ésta sea de mejor calidad y más estética.Suture is the final stage of surgery and as a consequence, a scar is frequently the only visible effect after an operation. LASH technique (Laser Assisted Scar Healing produces thermal effects to stimulate mechanisms for tissue repair that will determine the quality of

Facial Asymmetry-Based Age Group Estimation: Role in Recognizing Age-Separated Face Images.

Science.gov (United States)

Sajid, Muhammad; Taj, Imtiaz Ahmad; Bajwa, Usama Ijaz; Ratyal, Naeem Iqbal

2018-04-23

Face recognition aims to establish the identity of a person based on facial characteristics. On the other hand, age group estimation is the automatic calculation of an individual's age range based on facial features. Recognizing age-separated face images is still a challenging research problem due to complex aging processes involving different types of facial tissues, skin, fat, muscles, and bones. Certain holistic and local facial features are used to recognize age-separated face images. However, most of the existing methods recognize face images without incorporating the knowledge learned from age group estimation. In this paper, we propose an age-assisted face recognition approach to handle aging variations. Inspired by the observation that facial asymmetry is an age-dependent intrinsic facial feature, we first use asymmetric facial dimensions to estimate the age group of a given face image. Deeply learned asymmetric facial features are then extracted for face recognition using a deep convolutional neural network (dCNN). Finally, we integrate the knowledge learned from the age group estimation into the face recognition algorithm using the same dCNN. This integration results in a significant improvement in the overall performance compared to using the face recognition algorithm alone. The experimental results on two large facial aging datasets, the MORPH and FERET sets, show that the proposed age group estimation based on the face recognition approach yields superior performance compared to some existing state-of-the-art methods. © 2018 American Academy of Forensic Sciences.

Excimer laser-assisted anterior lamellar keratoplasty for keratoconus, corneal problems after laser in situ keratomileusis, and corneal stromal opacities.

Science.gov (United States)

Bilgihan, Kamil; Ozdek, Sengül C; Sari, Ayça; Hasanreisoğlu, Berati

2006-08-01

To evaluate excimer laser-assisted anterior lamellar keratoplasty to augment thin corneas as in keratoconus ( .05). This technique presents a different modality for the treatment of keratoconus, post-LASIK corneal problems, and other corneal stromal opacities with anterior lamellar keratoplasty. Additional studies with more patients and longer follow-up will help determine the role of this technique as a substitute for penetrating keratoplasty in these patients.

Matrix-assisted laser-desorption-ionization mass spectrometry of proteins using a free-electron laser

International Nuclear Information System (INIS)

Cramer, R.; Hillenkamp, F.; Haglund, R.

1995-01-01

Matrix-assisted laser desorption-ionization (MALDI) mass spectrometry (MS) is one of the most promising techniques for spectral fingerprinting large molecules, such as proteins, oligonucleotides and carbohydrates. In the usual implementation of this technique, the analyte molecule is dissolved in an aromatic liquid matrix material which resonantly absorbs ultraviolet laser light. Resonant absorption by π-π* transitions volatilizes the matrix and initiates subsequent charge transfer to the analyte molecules, which are detected by time-of-flight mass spectrometry. Recent MALDI-MS studies with Er:YAG (2.94 μm) and CO 2 4 (9.4-10.6 μm) lasers suggest that them is significant unexplored potential for mass spectrometry of macromolecules, including oligonucleotide, in the mid-infrared. Preliminary experiments show that it is possible to capitalize on the rich rovibronic absorption spectrum of virtually all organics to initiate resonant desorption in matrix material over the entire range of pH values. However, the mechanism of charge transfer is particularly problematic for infrared MALDI because of the low photon energy. In this paper, we report the results of MALI-MS studies on small proteins using the Vanderbilt FEL and several matrix materials. Proteins with masses up to roughly 6,000 amu were detected with high resolution in a linear time-of-flight mass spectrometer. By varying the pulse duration using a broadband Pockels cell, we have been able to compare the results of relatively long (5 μs) and short (0.1 μs) irradiation on the desorption and ionization processes. Compared to uv-MALDI spectra of identical analytes obtained with a nitrogen laser (337 nm) in the same time-of-flight spectrometer, the infrared results appear to show that the desorption and ionization process goes on over a somewhat longer time scale

The influence of different facial components on facial aesthetics.

NARCIS (Netherlands)

Faure, J.C.; Rieffe, C.; Maltha, J.C.

2002-01-01

Facial aesthetics have an important influence on social behaviour and perception in our society. The purpose of the present study was to evaluate the effect of facial symmetry and inter-ocular distance on the assessment of facial aesthetics, factors that are often suggested as major contributors to

Cell-Assisted Lipotransfer for the Treatment of Parry-Romberg Syndrome

OpenAIRE

Yanko Castro-Govea; Oscar De La Garza-Pineda; Jorge Lara-Arias; Hernán Chacón-Martínez; Gabriel Mecott-Rivera; Abel Salazar-Lozano; Everardo Valdes-Flores

2012-01-01

Progressive facial hemiatrophy, also known as Parry-Romberg syndrome, is a progressive and self-limited deformation of the subcutaneous tissue volume on one side of the face that creates craniofacial asymmetry. We present the case of a patient with a five-year history of progressive right facial hemiatrophy, who underwent facial volumetric restoration using cell-assisted lipotransfer (CAL), which consists of an autologous fat graft enriched with adipose-derived stem cells (ASCs) extracted fro...

Fiber laser with combined feedback of core and cladding modes assisted by an intracavity long-period grating.

Science.gov (United States)

Sáez-Rodriguez, D; Cruz, J L; Díez, A; Andrés, M V

2011-05-15

We present a fiber laser made in a single piece of conventional doped-core fiber that operates by combined feedback of the fundamental core mode LP((0,1)) and the high-order cladding mode LP((0,10)). The laser is an all-fiber structure that uses two fiber Bragg gratings and a long-period grating to select the modes circulating in the cavity; the laser emits at the coupling wavelength between the core mode LP((0,1)) and the counterpropagating cladding mode LP((0,10)) in the Bragg gratings. This work demonstrates the feasibility of high-order mode fiber lasers assisted by long-period gratings. © 2011 Optical Society of America

Influence of multi-hit capability on quantitative measurement of NiPtSi thin film with laser-assisted atom probe tomography

International Nuclear Information System (INIS)

Kinno, T.; Akutsu, H.; Tomita, M.; Kawanaka, S.; Sonehara, T.; Hokazono, A.; Renaud, L.; Martin, I.; Benbalagh, R.; Sallé, B.; Takeno, S.

2012-01-01

Highlights: ► Laser-assisted atom probe tomography was applied to NiPtSi films on Si substrates. ► Comparison of depth profiles of single-hit events and those of multi-hit events. ► ∼80% of Pt atoms were detected in multi-hit events. ► Multiple-ion detection is important for Laser-assisted atom probe tomography. - Abstract: Laser-assisted atom probe tomography (LA-APT) was applied to NiPtSi (0, 30, and 50% Pt contents) thin films on Si substrates. Consistent results with those of high-resolution Rutherford backscattering spectrometry (HR-RBS) were obtained. Based on the obtained data sets, the composition profiles from only the signals of single-hit events, meaning detection of one ion by one laser pulse, were compiled. The profiles from only the signals of multi-hit events, meaning detection of multiple ions by one laser pulse, were also compiled. There were large discrepancies with respect to Ni and Pt concentrations among the compiled profiles and the original profiles including the signals of both types of detection events. Additionally, the profiles compiled from single-hit events showed that Si concentration in NiPtSi layer became smaller toward the surface, differing from the original profiles and the multi-hit profiles. These results suggest that capability of simultaneous multiple-ion detection is important for appropriate LA-APT analyses.

A cognitive evaluation procedure for contour based shape descriptors

NARCIS (Netherlands)

Ghosh, Anarta; Petkov, Nicolai

2005-01-01

Present image processing algorithms are unable to extract a neat and closed contour of an object of interest from a natural image. Advanced contour detection algorithms extract the contour of an object of interest from a natural scene with a side effect of depletion of the contour. Hence in order to

Quantitative Anthropometric Measures of Facial Appearance of Healthy Hispanic/Latino White Children: Establishing Reference Data for Care of Cleft Lip With or Without Cleft Palate

Science.gov (United States)

Lee, Juhun; Ku, Brian; Combs, Patrick D.; Da Silveira, Adriana. C.; Markey, Mia K.

2017-06-01

Cleft lip with or without cleft palate (CL ± P) is one of the most common congenital facial deformities worldwide. To minimize negative social consequences of CL ± P, reconstructive surgery is conducted to modify the face to a more normal appearance. Each race/ethnic group requires its own facial norm data, yet there are no existing facial norm data for Hispanic/Latino White children. The objective of this paper is to identify measures of facial appearance relevant for planning reconstructive surgery for CL ± P of Hispanic/Latino White children. Quantitative analysis was conducted on 3D facial images of 82 (41 girls, 41 boys) healthy Hispanic/Latino White children whose ages ranged from 7 to 12 years. Twenty-eight facial anthropometric features related to CL ± P (mainly in the nasal and mouth area) were measured from 3D facial images. In addition, facial aesthetic ratings were obtained from 16 non-clinical observers for the same 3D facial images using a 7-point Likert scale. Pearson correlation analysis was conducted to find features that were correlated with the panel ratings of observers. Boys with a longer face and nose, or thicker upper and lower lips are considered more attractive than others while girls with a less curved middle face contour are considered more attractive than others. Associated facial landmarks for these features are primary focus areas for reconstructive surgery for CL ± P. This study identified anthropometric measures of facial features of Hispanic/Latino White children that are pertinent to CL ± P and which correlate with the panel attractiveness ratings.

Efficacy of the fractional photothermolysis system with dynamic operating mode on acne scars and enlarged facial pores.

Science.gov (United States)

Cho, Sung Bin; Lee, Ju Hee; Choi, Moon Jung; Lee, Kyu-Yeop; Oh, Sang Ho

2009-01-01

Current treatments for acne scars and enlarged facial pores have shown limited efficacy. To evaluate the efficacy and safety of the fractional photothermolysis system (FPS) with dynamic operating mode on acne scars and enlarged pores. Twelve patients with mild to moderate atrophic acne scars and enlarged pores were included in this study. Three sessions of FPS treatment were performed for acne scars and facial pores monthly. Two blinded dermatologists who compared before and after photos based on a quartile grading scale conducted objective clinical assessments of acne scar- and facial pore-treated areas. We took a biopsy immediately after one treatment with the laser from one of the authors to assess the histologic effects of the laser on facial pores. Follow-up results at 4 months after the last treatment revealed that, of the 12 patients, for acne scars, five demonstrated clinical improvements of 51% to 75% and three demonstrated improvements of 76% to 100%, and for facial pores, five demonstrated moderate clinical improvements of 26% to 50% and three demonstrated improvements of 76% to 100%. Side effects, including pain, post-treatment erythema, and edema, were resolved within 1 week. We suggest that the FPS may provide a new treatment algorithm in some cases with acne scars and enlarged pores. Considering the lack of placebo-controlled, split-face design of our study, optimized, prospective studies should be conducted to fully assess the efficacy of FPS with dynamic operating mode.

The role of great auricular-facial nerve neurorrhaphy in facial nerve damage

OpenAIRE

Sun, Yan; Liu, Limei; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo

2015-01-01

Background: Facial nerve is easy to be damaged, and there are many reconstructive methods for facial nerve reconstructive, such as facial nerve end to end anastomosis, the great auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. However, there is still little study about great auricular-facial nerve neurorrhaphy. The aim of the present study was to identify the role of great auricular-facial nerve neurorrhaphy and the mechanism. Methods: Rat models of facia...

A Biologically Motivated Multiresolution Approach to Contour Detection

Directory of Open Access Journals (Sweden)

Alessandro Neri

2007-01-01

Full Text Available Standard edge detectors react to all local luminance changes, irrespective of whether they are due to the contours of the objects represented in a scene or due to natural textures like grass, foliage, water, and so forth. Moreover, edges due to texture are often stronger than edges due to object contours. This implies that further processing is needed to discriminate object contours from texture edges. In this paper, we propose a biologically motivated multiresolution contour detection method using Bayesian denoising and a surround inhibition technique. Specifically, the proposed approach deploys computation of the gradient at different resolutions, followed by Bayesian denoising of the edge image. Then, a biologically motivated surround inhibition step is applied in order to suppress edges that are due to texture. We propose an improvement of the surround suppression used in previous works. Finally, a contour-oriented binarization algorithm is used, relying on the observation that object contours lead to long connected components rather than to short rods obtained from textures. Experimental results show that our contour detection method outperforms standard edge detectors as well as other methods that deploy inhibition.

Facial soft tissue analysis among various vertical facial patterns

International Nuclear Information System (INIS)

Jeelani, W.; Fida, M.; Shaikh, A.

2016-01-01

Background: The emergence of soft tissue paradigm in orthodontics has made various soft tissue parameters an integral part of the orthodontic problem list. The purpose of this study was to determine and compare various facial soft tissue parameters on lateral cephalograms among patients with short, average and long facial patterns. Methods: A cross-sectional study was conducted on the lateral cephalograms of 180 adult subjects divided into three equal groups, i.e., short, average and long face according to the vertical facial pattern. Incisal display at rest, nose height, upper and lower lip lengths, degree of lip procumbency and the nasolabial angle were measured for each individual. The gender differences for these soft tissue parameters were determined using Mann-Whitney U test while the comparison among different facial patterns was performed using Kruskal-Wallis test. Results: Significant differences in the incisal display at rest, total nasal height, lip procumbency, the nasolabial angle and the upper and lower lip lengths were found among the three vertical facial patterns. A significant positive correlation of nose and lip dimensions was found with the underlying skeletal pattern. Similarly, the incisal display at rest, upper and lower lip procumbency and the nasolabial angle were significantly correlated with the lower anterior facial height. Conclusion: Short facial pattern is associated with minimal incisal display, recumbent upper and lower lips and acute nasolabial angle while the long facial pattern is associated with excessive incisal display, procumbent upper and lower lips and obtuse nasolabial angle. (author)

Quantitation of peptides and proteins by matrix-assisted laser desorption/ionization mass spectrometry using (18)O-labeled internal standards

DEFF Research Database (Denmark)

Mirgorodskaya, O A; Kozmin, Y P; Titov, M I

2000-01-01

A method for quantitating proteins and peptides in the low picomole and sub-picomole range has been developed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) with internal (18)O-labeled standards. A simple procedure is proposed to produce such internal standards for...... inhibitor, were quantified by MALDI-time-of-flight (TOF) mass spectrometry.......A method for quantitating proteins and peptides in the low picomole and sub-picomole range has been developed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) with internal (18)O-labeled standards. A simple procedure is proposed to produce such internal standards...

The equivalent internal orientation and position noise for contour integration.

Science.gov (United States)

Baldwin, Alex S; Fu, Minnie; Farivar, Reza; Hess, Robert F

2017-10-12

Contour integration is the joining-up of local responses to parts of a contour into a continuous percept. In typical studies observers detect contours formed of discrete wavelets, presented against a background of random wavelets. This measures performance for detecting contours in the limiting external noise that background provides. Our novel task measures contour integration without requiring any background noise. This allowed us to perform noise-masking experiments using orientation and position noise. From these we measure the equivalent internal noise for contour integration. We found an orientation noise of 6° and position noise of 3 arcmin. Orientation noise was 2.6x higher in contour integration compared to an orientation discrimination control task. Comparing against a position discrimination task found position noise in contours to be 2.4x lower. This suggests contour integration involves intermediate processing that enhances the quality of element position representation at the expense of element orientation. Efficiency relative to the ideal observer was lower for the contour tasks (36% in orientation noise, 21% in position noise) compared to the controls (54% and 57%).

Dynamic Facial Prosthetics for Sufferers of Facial Paralysis

Directory of Open Access Journals (Sweden)

Fergal Coulter

2011-10-01

Full Text Available BackgroundThis paper discusses the various methods and the materialsfor the fabrication of active artificial facial muscles. Theprimary use for these will be the reanimation of paralysedor atrophied muscles in sufferers of non-recoverableunilateral facial paralysis.MethodThe prosthetic solution described in this paper is based onsensing muscle motion of the contralateral healthy musclesand replicating that motion across a patient’s paralysed sideof the face, via solid state and thin film actuators. Thedevelopment of this facial prosthetic device focused onrecreating a varying intensity smile, with emphasis ontiming, displacement and the appearance of the wrinklesand folds that commonly appear around the nose and eyesduring the expression.An animatronic face was constructed with actuations beingmade to a silicone representation musculature, usingmultiple shape-memory alloy cascades. Alongside theartificial muscle physical prototype, a facial expressionrecognition software system was constructed. This formsthe basis of an automated calibration and reconfigurationsystem for the artificial muscles following implantation, soas to suit the implantee’s unique physiognomy.ResultsAn animatronic model face with silicone musculature wasdesigned and built to evaluate the performance of ShapeMemory Alloy artificial muscles, their power controlcircuitry and software control systems. A dual facial motionsensing system was designed to allow real time control overmodel – a piezoresistive flex sensor to measure physicalmotion, and a computer vision system to evaluate real toartificial muscle performance.Analysis of various facial expressions in real subjects wasmade, which give useful data upon which to base thesystems parameter limits.ConclusionThe system performed well, and the various strengths andshortcomings of the materials and methods are reviewedand considered for the next research phase, when newpolymer based artificial muscles are constructed

Facial Fractures.

Science.gov (United States)

Ghosh, Rajarshi; Gopalkrishnan, Kulandaswamy

2018-06-01

The aim of this study is to retrospectively analyze the incidence of facial fractures along with age, gender predilection, etiology, commonest site, associated dental injuries, and any complications of patients operated in Craniofacial Unit of SDM College of Dental Sciences and Hospital. This retrospective study was conducted at the Department of OMFS, SDM College of Dental Sciences, Dharwad from January 2003 to December 2013. Data were recorded for the cause of injury, age and gender distribution, frequency and type of injury, localization and frequency of soft tissue injuries, dentoalveolar trauma, facial bone fractures, complications, concomitant injuries, and different treatment protocols.All the data were analyzed using statistical analysis that is chi-squared test. A total of 1146 patients reported at our unit with facial fractures during these 10 years. Males accounted for a higher frequency of facial fractures (88.8%). Mandible was the commonest bone to be fractured among all the facial bones (71.2%). Maxillary central incisors were the most common teeth to be injured (33.8%) and avulsion was the most common type of injury (44.6%). Commonest postoperative complication was plate infection (11%) leading to plate removal. Other injuries associated with facial fractures were rib fractures, head injuries, upper and lower limb fractures, etc., among these rib fractures were seen most frequently (21.6%). This study was performed to compare the different etiologic factors leading to diverse facial fracture patterns. By statistical analysis of this record the authors come to know about the relationship of facial fractures with gender, age, associated comorbidities, etc.

A novel computerized surgeon-machine interface for robot-assisted laser phonomicrosurgery.

Science.gov (United States)

Mattos, Leonardo S; Deshpande, Nikhil; Barresi, Giacinto; Guastini, Luca; Peretti, Giorgio

2014-08-01

To introduce a novel computerized surgical system for improved usability, intuitiveness, accuracy, and controllability in robot-assisted laser phonomicrosurgery. Pilot technology assessment. The novel system was developed involving a newly designed motorized laser micromanipulator, a touch-screen display, and a graphics stylus. The system allows the control of a CO2 laser through interaction between the stylus and the live video of the surgical area. This empowers the stylus with the ability to have actual effect on the surgical site. Surgical enhancements afforded by this system were established through a pilot technology assessment using randomized trials comparing its performance with a state-of-the-art laser microsurgery system. Resident surgeons and medical students were chosen as subjects in performing sets of trajectory-following exercises. Image processing-based techniques were used for an objective performance assessment. A System Usability Scale-based questionnaire was used for the qualitative assessment. The computerized interface demonstrated superiority in usability, accuracy, and controllability over the state-of-the-art system. Significant ease of use and learning experienced by the subjects were demonstrated by the usability score assigned to the two compared interfaces: computerized interface = 83.96% versus state-of-the-art = 68.02%. The objective analysis showed a significant enhancement in accuracy and controllability: computerized interface = 90.02% versus state-of-the-art = 75.59%. The novel system significantly enhances the accuracy, usability, and controllability in laser phonomicrosurgery. The design provides an opportunity to improve the ergonomics and safety of current surgical setups. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Corneal biomechanical properties after laser-assisted in situ keratomileusis and photorefractive keratectomy

Directory of Open Access Journals (Sweden)

Hwang ES

2017-10-01

Full Text Available Eileen S Hwang,1 Brian C Stagg,1 Russell Swan,1 Carlton R Fenzl,1 Molly McFadden,2 Valliammai Muthappan,1 Luis Santiago-Caban,1 Mark D Mifflin,1 Majid Moshirfar1,3 1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, 2Department of Internal Medicine, University of Utah, Salt Lake City, 3HDR Research Center, Hoopes Vision, Draper, UT, USA Background: The purpose of this study was to evaluate the effects of laser-assisted in situ keratomileusis (LASIK and photorefractive keratectomy (PRK on corneal biomechanical properties.Methods: We used the ocular response analyzer to measure corneal hysteresis (CH and corneal resistance factor (CRF before and after refractive surgery.Results: In all, 230 eyes underwent LASIK and 115 eyes underwent PRK without mitomycin C (MMC. Both procedures decreased CH and CRF from baseline. When MMC was used after PRK in 20 eyes, it resulted in lower corneal biomechanical properties at 3 months when compared to the other procedures, but all three procedures had similar values at 12 months.Conclusion: Significant but similar decreases in corneal biomechanical properties after LASIK, PRK without MMC, and PRK with MMC were noted. Keywords: corneal biomechanics, photorefractive keratectomy, laser-assisted in situ keratomileusis, corneal hysteresis, corneal resistance factor, mitomycin C

Image Interpolation with Contour Stencils

OpenAIRE

Pascal Getreuer

2011-01-01

Image interpolation is the problem of increasing the resolution of an image. Linear methods must compromise between artifacts like jagged edges, blurring, and overshoot (halo) artifacts. More recent works consider nonlinear methods to improve interpolation of edges and textures. In this paper we apply contour stencils for estimating the image contours based on total variation along curves and then use this estimation to construct a fast edge-adaptive interpolation.

A study of the machining characteristics of AISI 1045 steel and Inconel 718 with a cylindrical shape in laser-assisted milling

International Nuclear Information System (INIS)

Woo, Wan-Sik; Lee, Choon-Man

2015-01-01

Laser-assisted machining (LAM) is an effective and economic technique for enhancing the machinability of materials which are difficult-to-cut, such as nickel alloys, titanium alloys and various ceramics. Recently, many researchers have studied the effectiveness of laser-assisted turning (LAT) by measuring its cutting force, tool wear, specific cutting energy and surface roughness. However, research on laser-assisted milling (LAMill) is still in progress because it is difficult to control the laser heating source and tool path to machine the varying shape of the workpiece using this method. Moreover, there have been no researches of workpieces with three-dimensional shapes. During the LAMill process, the material is softened and the mechanical strength of the material is reduced when a laser is used to irradiate the surface of the workpiece. As a result, the cutting force is reduced and the surface roughness is improved with LAMill. The purpose of this study was to develop three-dimensional LAMill and to verify the effectiveness of this approach by comparing it to the conventional machining (CM) method. A thermal analysis was also conducted in order to determine the effective depth of cut (DOC). Also, the cutting force and surface roughness of AISI 1045 steel and Inconel 718 with cylindrical shapes were measured. Measured results of machining characteristics were also analyzed according to the cutting method, i.e., up cut milling, down cut milling and milling style. - Highlights: • The materials with cylindrical shape is first applied to laser-assisted milling (LAMill). • The method determining the depth of cut through thermal analysis is proposed. • The effectiveness of LAMill is verified by comparing the conventional machining. • Down cut milling is recommended for the case of Inconel 718.

Interactive 3D segmentation using connected orthogonal contours

NARCIS (Netherlands)

de Bruin, P. W.; Dercksen, V. J.; Post, F. H.; Vossepoel, A. M.; Streekstra, G. J.; Vos, F. M.

2005-01-01

This paper describes a new method for interactive segmentation that is based on cross-sectional design and 3D modelling. The method represents a 3D model by a set of connected contours that are planar and orthogonal. Planar contours overlayed on image data are easily manipulated and linked contours

Contour plotting programs for printer and Calcomp plotter

International Nuclear Information System (INIS)

Moller, P.

1980-07-01

Contour plotting programs for plotting contour diagrams on printers or Calcomp plotters are described. The subroutines also exist in versions that are useful for the special application of finding minima and saddlepoints of nuclear potential energy surfaces generated by the subroutine PETR3 of another program package. For the general user, however, the most interesting aspect of the plotting package is probably the possibility of generating printer contour plots. The plotting of printer contour plots is a very fast and convenient way of displaying two-dimensional functions. 3 figures

Depth-resolved phase retardation measurements for laser-assisted non-ablative cartilage reshaping

Energy Technology Data Exchange (ETDEWEB)

Youn, Jong-In [Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 (United States); Vargas, Gracie [Center for Bioengineering, University of Texas Medical Branch, Galveston, TX 77555 (United States); Wong, Brian J F [Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612 (United States); Milner, Thomas E [Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 (United States)

2005-05-07

Since polarization-sensitive optical coherence tomography (PS-OCT) is emerging as a new technique for determining phase retardation in biological materials, we measured phase retardation changes in cartilage during local laser heating for application to laser-assisted cartilage reshaping. Thermally-induced changes in phase retardation of nasal septal cartilage following Nd:YAG laser irradiation were investigated using a PS-OCT system. A PS-OCT system and infrared imaging radiometer were used to record, respectively, depth-resolved images of the Stokes parameters of light backscattered from ex vivo porcine nasal septal cartilage and radiometric temperature changes following laser irradiation. PS-OCT images of cartilage were recorded before (control), during and after laser irradiation. From the measured Stokes parameters (I, Q, U and V), an estimate of the relative phase retardation between two orthogonal polarizations was computed to determine birefringence in cartilage. Phase retardation images of light backscattered from cartilage show significant changes in retardation following laser irradiation. To investigate the origin of retardation changes in response to local heat generation, we differentiated two possible mechanisms: dehydration and thermal denaturation. PS-OCT images of cartilage were recorded after dehydration in glycerol and thermal denaturation in heated physiological saline. In our experiments, observed retardation changes in cartilage are primarily due to dehydration. Since dehydration is a principal source for retardation changes in cartilage over the range of heating profiles investigated, our studies suggest that the use of PS-OCT as a feedback control methodology for non-ablative cartilage reshaping requires further investigation.

Depth-resolved phase retardation measurements for laser-assisted non-ablative cartilage reshaping

International Nuclear Information System (INIS)

Youn, Jong-In; Vargas, Gracie; Wong, Brian J F; Milner, Thomas E

2005-01-01

Since polarization-sensitive optical coherence tomography (PS-OCT) is emerging as a new technique for determining phase retardation in biological materials, we measured phase retardation changes in cartilage during local laser heating for application to laser-assisted cartilage reshaping. Thermally-induced changes in phase retardation of nasal septal cartilage following Nd:YAG laser irradiation were investigated using a PS-OCT system. A PS-OCT system and infrared imaging radiometer were used to record, respectively, depth-resolved images of the Stokes parameters of light backscattered from ex vivo porcine nasal septal cartilage and radiometric temperature changes following laser irradiation. PS-OCT images of cartilage were recorded before (control), during and after laser irradiation. From the measured Stokes parameters (I, Q, U and V), an estimate of the relative phase retardation between two orthogonal polarizations was computed to determine birefringence in cartilage. Phase retardation images of light backscattered from cartilage show significant changes in retardation following laser irradiation. To investigate the origin of retardation changes in response to local heat generation, we differentiated two possible mechanisms: dehydration and thermal denaturation. PS-OCT images of cartilage were recorded after dehydration in glycerol and thermal denaturation in heated physiological saline. In our experiments, observed retardation changes in cartilage are primarily due to dehydration. Since dehydration is a principal source for retardation changes in cartilage over the range of heating profiles investigated, our studies suggest that the use of PS-OCT as a feedback control methodology for non-ablative cartilage reshaping requires further investigation

Relativistic electronic dressing in laser-assisted ionization of atomic hydrogen by electron impact

International Nuclear Information System (INIS)

Attaourti, Y.; Taj, S.

2004-01-01

Within the framework of the coplanar binary geometry where it is justified to use plane wave solutions for the study of the (e,2e) reaction and in the presence of a circularly polarized laser field, we introduce as a first step the Dirac-Volkov plane wave Born approximation 1 where we take into account only the relativistic dressing of the incident and scattered electrons. Then, we introduce the Dirac-Volkov plane wave Born approximation 2 where we take totally into account the relativistic dressing of the incident, scattered, and ejected electrons. We then compare the corresponding triple differential cross sections for laser-assisted ionization of atomic hydrogen by electron impact both for the nonrelativistic and the relativistic regime

GPU based contouring method on grid DEM data

Science.gov (United States)

Tan, Liheng; Wan, Gang; Li, Feng; Chen, Xiaohui; Du, Wenlong

2017-08-01

This paper presents a novel method to generate contour lines from grid DEM data based on the programmable GPU pipeline. The previous contouring approaches often use CPU to construct a finite element mesh from the raw DEM data, and then extract contour segments from the elements. They also need a tracing or sorting strategy to generate the final continuous contours. These approaches can be heavily CPU-costing and time-consuming. Meanwhile the generated contours would be unsmooth if the raw data is sparsely distributed. Unlike the CPU approaches, we employ the GPU's vertex shader to generate a triangular mesh with arbitrary user-defined density, in which the height of each vertex is calculated through a third-order Cardinal spline function. Then in the same frame, segments are extracted from the triangles by the geometry shader, and translated to the CPU-side with an internal order in the GPU's transform feedback stage. Finally we propose a "Grid Sorting" algorithm to achieve the continuous contour lines by travelling the segments only once. Our method makes use of multiple stages of GPU pipeline for computation, which can generate smooth contour lines, and is significantly faster than the previous CPU approaches. The algorithm can be easily implemented with OpenGL 3.3 API or higher on consumer-level PCs.

Active contour-based visual tracking by integrating colors, shapes, and motions.

Science.gov (United States)

Hu, Weiming; Zhou, Xue; Li, Wei; Luo, Wenhan; Zhang, Xiaoqin; Maybank, Stephen

2013-05-01

In this paper, we present a framework for active contour-based visual tracking using level sets. The main components of our framework include contour-based tracking initialization, color-based contour evolution, adaptive shape-based contour evolution for non-periodic motions, dynamic shape-based contour evolution for periodic motions, and the handling of abrupt motions. For the initialization of contour-based tracking, we develop an optical flow-based algorithm for automatically initializing contours at the first frame. For the color-based contour evolution, Markov random field theory is used to measure correlations between values of neighboring pixels for posterior probability estimation. For adaptive shape-based contour evolution, the global shape information and the local color information are combined to hierarchically evolve the contour, and a flexible shape updating model is constructed. For the dynamic shape-based contour evolution, a shape mode transition matrix is learnt to characterize the temporal correlations of object shapes. For the handling of abrupt motions, particle swarm optimization is adopted to capture the global motion which is applied to the contour in the current frame to produce an initial contour in the next frame.

Facial Curvature Detects and Explicates Ethnic Differences in Effects of Prenatal Alcohol Exposure.

Science.gov (United States)

Suttie, Michael; Wetherill, Leah; Jacobson, Sandra W; Jacobson, Joseph L; Hoyme, H Eugene; Sowell, Elizabeth R; Coles, Claire; Wozniak, Jeffrey R; Riley, Edward P; Jones, Kenneth L; Foroud, Tatiana; Hammond, Peter

2017-08-01

Our objective is to help clinicians detect the facial effects of prenatal alcohol exposure by developing computer-based tools for screening facial form. All 415 individuals considered were evaluated by expert dysmorphologists and categorized as (i) healthy control (HC), (ii) fetal alcohol syndrome (FAS), or (iii) heavily prenatally alcohol exposed (HE) but not clinically diagnosable as FAS; 3D facial photographs were used to build models of facial form to support discrimination studies. Surface curvature-based delineations of facial form were introduced. (i) Facial growth in FAS, HE, and control subgroups is similar in both cohorts. (ii) Cohort consistency of agreement between clinical diagnosis and HC-FAS facial form classification is lower for midline facial regions and higher for nonmidline regions. (iii) Specific HC-FAS differences within and between the cohorts include: for HC, a smoother philtrum in Cape Coloured individuals; for FAS, a smoother philtrum in Caucasians; for control-FAS philtrum difference, greater homogeneity in Caucasians; for control-FAS face difference, greater homogeneity in Cape Coloured individuals. (iv) Curvature changes in facial profile induced by prenatal alcohol exposure are more homogeneous and greater in Cape Coloureds than in Caucasians. (v) The Caucasian HE subset divides into clusters with control-like and FAS-like facial dysmorphism. The Cape Coloured HE subset is similarly divided for nonmidline facial regions but not clearly for midline structures. (vi) The Cape Coloured HE subset with control-like facial dysmorphism shows orbital hypertelorism. Facial curvature assists the recognition of the effects of prenatal alcohol exposure and helps explain why different facial regions result in inconsistent control-FAS discrimination rates in disparate ethnic groups. Heavy prenatal alcohol exposure can give rise to orbital hypertelorism, supporting a long-standing suggestion that prenatal alcohol exposure at a particular time causes

Noninvasive Body Contouring: A Male Perspective.

Science.gov (United States)

Wat, Heidi; Wu, Douglas C; Goldman, Mitchel P

2018-01-01

Noninvasive body contouring is an attractive therapeutic modality to enhance the ideal male physique. Men place higher value on enhancing a well-defined, strong, masculine jawline and developing a V-shaped taper through the upper body. An understanding of the body contour men strive for allows the treating physician to focus on areas that are of most concern to men, thus enhancing patient experience and satisfaction. This article discusses noninvasive body contouring techniques, taking into account the unique aesthetic concerns of the male patient by combining an analysis of the existing literature with our own clinical experience. Copyright © 2017 Elsevier Inc. All rights reserved.

The Characterization of Laser Ablation Patterns and a New Definition of Resolution in Matrix Assisted Laser Desorption Ionization Imaging Mass Spectrometry (MALDI-IMS).

Science.gov (United States)

O'Rourke, Matthew B; Raymond, Benjamin B A; Padula, Matthew P

2017-05-01

Matrix assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS) is a technique that has seen a sharp rise in both use and development. Despite this rapid adoption, there have been few thorough investigations into the actual physical mechanisms that underlie the acquisition of IMS images. We therefore set out to characterize the effect of IMS laser ablation patterns on the surface of a sample. We also concluded that the governing factors that control spatial resolution have not been correctly defined and therefore propose a new definition of resolution. Graphical Abstract ᅟ.

Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration.

Science.gov (United States)

Bourget, Jean-Michel; Kérourédan, Olivia; Medina, Manuela; Rémy, Murielle; Thébaud, Noélie Brunehilde; Bareille, Reine; Chassande, Olivier; Amédée, Joëlle; Catros, Sylvain; Devillard, Raphaël

2016-01-01

Tissue engineering of large organs is currently limited by the lack of potent vascularization in vitro . Tissue-engineered bone grafts can be prevascularized in vitro using endothelial cells (ECs). The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors.

Adolescents with HIV and facial lipoatrophy: response to facial stimulation

Directory of Open Access Journals (Sweden)

Jesus Claudio Gabana-Silveira

2014-08-01

Full Text Available OBJECTIVES: This study evaluated the effects of facial stimulation over the superficial muscles of the face in individuals with facial lipoatrophy associated with human immunodeficiency virus (HIV and with no indication for treatment with polymethyl methacrylate. METHOD: The study sample comprised four adolescents of both genders ranging from 13 to 17 years in age. To participate in the study, the participants had to score six or less points on the Facial Lipoatrophy Index. The facial stimulation program used in our study consisted of 12 weekly 30-minute sessions during which individuals received therapy. The therapy consisted of intra- and extra-oral muscle contraction and stretching maneuvers of the zygomaticus major and minor and the masseter muscles. Pre- and post-treatment results were obtained using anthropometric static measurements of the face and the Facial Lipoatrophy Index. RESULTS: The results suggest that the therapeutic program effectively improved the volume of the buccinators. No significant differences were observed for the measurements of the medial portion of the face, the lateral portion of the face, the volume of the masseter muscle, or Facial Lipoatrophy Index scores. CONCLUSION: The results of our study suggest that facial maneuvers applied to the superficial muscles of the face of adolescents with facial lipoatrophy associated with HIV improved the facial area volume related to the buccinators muscles. We believe that our results will encourage future research with HIV patients, especially for patients who do not have the possibility of receiving an alternative aesthetic treatment.

Prosthodontist contribution in treating post-burn hypertrophic facial scars

Directory of Open Access Journals (Sweden)

Padmanabhan T

2010-01-01

Full Text Available The formation of hypertrophic scars is common following healing of the burn wound, particularly in children. The face is one of the areas of the body most frequently affected by burns. Scar formation as a result of burn wounds leads to contraction of the formed granulation tissue, which causes both aesthetic and functional impairment for the patient. Scarring has major psychological and physical repercussions. Scarring on the face and visible regions of the body can be very distressing for the patient. Prevention of scars involves early and continuous use of a compressive orthesis. However, their efficacy is often limited to the facial region because of the contours of this area of body. This paper describes a clinical case of post-burn hypertrophic scars treated with silicone gel sheeting applied with pressure under custom made auto-polymerizing resin stent.

Ejection of matrix-polymer clusters in matrix-assisted laser evaporation: Experimental observations

International Nuclear Information System (INIS)

Sellinger, Aaron T; Leveugle, Elodie; Gogick, Kristy; Peman, Guillaume; Zhigilei, Leonid V; Fitz-Gerald, James M

2007-01-01

The morphology of polymer films deposited with the matrix-assisted pulsed laser evaporation (MAPLE) technique is explored for various target compositions and laser fluences. Composite targets of 1 to 5 wt.% poly(methyl methacrylate), PMMA, dissolved in a volatile matrix material, toluene, were ablated using an excimer laser at fluences ranging from 0.045 J/cm 2 to 0.75 J/cm 2 . Films were deposited on Si substrates at room temperature in a dynamic 100 mTorr Ar atmosphere. Scanning electron microscopy (SEM) imaging revealed that the morphology of the deposited films varied significantly with both laser fluence and PMMA concentration. The morphologies of large deposited particles were similar to that of deflated ''balloons''. It is speculated that during ablation of the frozen target, clusters comprised of both polymer and solvent ranging from 100 nm to 10 μm in size are ejected and deposited onto the substrate. The solvent begins to evaporate from the clusters during flight from the target, but does not completely evaporate until deposited on the room temperature substrate. The dynamics of the toluene evaporation may lead to the formation of the deflated structures. This explanation is supported by the observation of stable polymer-matrix droplets ejected in molecular dynamics simulations of MAPLE

Heat transfer and material flow during laser assisted multi-layer additive manufacturing

International Nuclear Information System (INIS)

Manvatkar, V.; De, A.; DebRoy, T.

2014-01-01

A three-dimensional, transient, heat transfer, and fluid flow model is developed for the laser assisted multilayer additive manufacturing process with coaxially fed austenitic stainless steel powder. Heat transfer between the laser beam and the powder particles is considered both during their flight between the nozzle and the growth surface and after they deposit on the surface. The geometry of the build layer obtained from independent experiments is compared with that obtained from the model. The spatial variation of melt geometry, cooling rate, and peak temperatures is examined in various layers. The computed cooling rates and solidification parameters are used to estimate the cell spacings and hardness in various layers of the structure. Good agreement is achieved between the computed geometry, cell spacings, and hardness with the corresponding independent experimental results.

Summing over Feynman histories by functional contour integration

International Nuclear Information System (INIS)

Garrison, J.C.; Wright, E.M.

1986-01-01

The authors show how complex paths can be consistently introduced into sums for Feynman histories by using the notion of functional contour integration. For a kappa-dimensional system specified by a potential with suitable analyticity properties, each coordinate axis is replaced by a copy of the complex plane, and at each instant of time a contour is chosen in each plane. This map from the time axis into the set of complex contours defines a functional contour. The family of contours labelled by time generates a (kappa+1)-dimensional submanifold of the (2kappa+1)-dimensional space defined by the cartesian product of the time axis and the coordinate planes. The complex Feynman paths lie on this submanifold. An application of this idea to systems described by absorptive potentials yields a simple derivation of the correct WKB result in terms of a complex path that extremalises the action. The method can also be applied to spherically symmetric potentials by using a partial wave expansion and restricting the contours appropriately. (author)

A facial marker in facial wasting rehabilitation.

Science.gov (United States)

Rauso, Raffaele; Tartaro, Gianpaolo; Freda, Nicola; Rusciani, Antonio; Curinga, Giuseppe

2012-02-01

Facial lipoatrophy is one of the most distressing manifestation for HIV patients. It can be stigmatizing, severely affecting quality of life and self-esteem, and it may result in reduced antiretroviral adherence. Several filling techniques have been proposed in facial wasting restoration, with different outcomes. The aim of this study is to present a triangular area that is useful to fill in facial wasting rehabilitation. Twenty-eight HIV patients rehabilitated for facial wasting were enrolled in this study. Sixteen were rehabilitated with a non-resorbable filler and twelve with structural fat graft harvested from lipohypertrophied areas. A photographic pre-operative and post-operative evaluation was performed by the patients and by two plastic surgeons who were "blinded." The filled area, in both patients rehabilitated with structural fat grafts or non-resorbable filler, was a triangular area of depression identified between the nasolabial fold, the malar arch, and the line that connects these two anatomical landmarks. The cosmetic result was evaluated after three months after the last filling procedure in the non-resorbable filler group and after three months post-surgery in the structural fat graft group. The mean patient satisfaction score was 8.7 as assessed with a visual analogue scale. The mean score for blinded evaluators was 7.6. In this study the authors describe a triangular area of the face, between the nasolabial fold, the malar arch, and the line that connects these two anatomical landmarks, where a good aesthetic facial restoration in HIV patients with facial wasting may be achieved regardless of which filling technique is used.

A Pilot Study Assessing the Feasibility of a Facial Emotion Training Paradigm for School-Age Children with Autism Spectrum Disorders

Science.gov (United States)

Russo-Ponsaran, Nicole M.; Evans-Smith, Bernadette; Johnson, Jason K.; McKown, Clark

2014-01-01

Many children with autism spectrum disorders (ASDs) demonstrate facial emotion recognition and expression impairments. These impairments may contribute to social disability and may put children with ASDs at risk for developing further mental health problems. In this pilot study, we examined the use of a coach- and computer-assisted facial emotion…

Combining prior day contours to improve automated prostate segmentation

International Nuclear Information System (INIS)

Godley, Andrew; Sheplan Olsen, Lawrence J.; Stephans, Kevin; Zhao Anzi

2013-01-01

Purpose: To improve the accuracy of automatically segmented prostate, rectum, and bladder contours required for online adaptive therapy. The contouring accuracy on the current image guidance [image guided radiation therapy (IGRT)] scan is improved by combining contours from earlier IGRT scans via the simultaneous truth and performance level estimation (STAPLE) algorithm. Methods: Six IGRT prostate patients treated with daily kilo-voltage (kV) cone-beam CT (CBCT) had their original plan CT and nine CBCTs contoured by the same physician. Three types of automated contours were produced for analysis. (1) Plan: By deformably registering the plan CT to each CBCT and then using the resulting deformation field to morph the plan contours to match the CBCT anatomy. (2) Previous: The contour set drawn by the physician on the previous day CBCT is similarly deformed to match the current CBCT anatomy. (3) STAPLE: The contours drawn by the physician, on each prior CBCT and the plan CT, are deformed to match the CBCT anatomy to produce multiple contour sets. These sets are combined using the STAPLE algorithm into one optimal set. Results: Compared to plan and previous, STAPLE improved the average Dice's coefficient (DC) with the original physician drawn CBCT contours to a DC as follows: Bladder: 0.81 ± 0.13, 0.91 ± 0.06, and 0.92 ± 0.06; Prostate: 0.75 ± 0.08, 0.82 ± 0.05, and 0.84 ± 0.05; and Rectum: 0.79 ± 0.06, 0.81 ± 0.06, and 0.85 ± 0.04, respectively. The STAPLE results are within intraobserver consistency, determined by the physician blindly recontouring a subset of CBCTs. Comparing plans recalculated using the physician and STAPLE contours showed an average disagreement less than 1% for prostate D98 and mean dose, and 5% and 3% for bladder and rectum mean dose, respectively. One scan takes an average of 19 s to contour. Using five scans plus STAPLE takes less than 110 s on a 288 core graphics processor unit. Conclusions: Combining the plan and all prior days via

Real-time laser holographic interferometry for aerodynamics

International Nuclear Information System (INIS)

Lee, G.

1987-01-01

Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil pressure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer. 13 references

Variation in contour and cancer of stomach

International Nuclear Information System (INIS)

Lee, Won Hong; Hwang, Seon Moon; Yoon, Kwon Ha

1999-01-01

There were four types of stomach contour included eutonic, hypotonic, steerhorn, and cascade. The aim of this study is to clarify relationship between incidence of stomach cancer and contour variation of the stomach. Double- contrast upper gastrointestinal study was performed in 1,546 patients, who had dyspepsia or other gastrointestinal tract symptoms. The radiographs were classified into the four types including eutonic, hypotonic, steerhorn, and cascade according to stomach contour in relation to body build. We also reviewed pathologic reports on endoscopic biopsy or surgical specimen. We studied the presence of relationship between incidence of stomach cancer and variation of stomach contour. We also examined the incidence of gastritis and gastric ulcer to the stomach contour variation. Of total 1,546 patients, eutonic stomach were 438(28.3%), hypotonic 911(58.9%), steerhorn 102(6.5%) and cascade 95(6.2%). Stomach cancer was found in 139(31.7%) of 438 eutonic stomachs, in 135(14.8%) of 911 hypotonic, in 42(41.2%) of 102 steerhorn, and in 24(36.9%) of 95 cascade (P=0.001). In hypotonic stomach, the incidence of stomach cancer was lower compared to the other three types significantly (p<0.05). Gastritis or gastric ulcer was found in 146(33.3%) of eutonic stomach, in 293(32.1%) of hypotonic, in 36(35.2%) of steerhorn, and in 26(27.3%) of cascade (p=0.640). In conclusion, gastric contour variation seems to be a factor affecting development of stomach cancer. The patients with hypotonic stomach may have lower incidence of stomach cancer than that of the other types. There was no relationship between the contour and gastric ulcer

Variation in contour and cancer of stomach

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Hong; Hwang, Seon Moon [Asan Medical Center, Asan (Korea, Republic of); Yoon, Kwon Ha [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

1999-04-01

There were four types of stomach contour included eutonic, hypotonic, steerhorn, and cascade. The aim of this study is to clarify relationship between incidence of stomach cancer and contour variation of the stomach. Double- contrast upper gastrointestinal study was performed in 1,546 patients, who had dyspepsia or other gastrointestinal tract symptoms. The radiographs were classified into the four types including eutonic, hypotonic, steerhorn, and cascade according to stomach contour in relation to body build. We also reviewed pathologic reports on endoscopic biopsy or surgical specimen. We studied the presence of relationship between incidence of stomach cancer and variation of stomach contour. We also examined the incidence of gastritis and gastric ulcer to the stomach contour variation. Of total 1,546 patients, eutonic stomach were 438(28.3%), hypotonic 911(58.9%), steerhorn 102(6.5%) and cascade 95(6.2%). Stomach cancer was found in 139(31.7%) of 438 eutonic stomachs, in 135(14.8%) of 911 hypotonic, in 42(41.2%) of 102 steerhorn, and in 24(36.9%) of 95 cascade (P=0.001). In hypotonic stomach, the incidence of stomach cancer was lower compared to the other three types significantly (p<0.05). Gastritis or gastric ulcer was found in 146(33.3%) of eutonic stomach, in 293(32.1%) of hypotonic, in 36(35.2%) of steerhorn, and in 26(27.3%) of cascade (p=0.640). In conclusion, gastric contour variation seems to be a factor affecting development of stomach cancer. The patients with hypotonic stomach may have lower incidence of stomach cancer than that of the other types. There was no relationship between the contour and gastric ulcer.

The Effect of Collimating Lens Focusing on Laser Beam Shape in Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS).

Science.gov (United States)

O'Rourke, Matthew B; Raymond, Benjamin B A; Djordjevic, Steven P; Padula, Matthew P

2018-03-01

Tissue imaging using matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a well-established technique that, in recent years, has seen wider adoption and novel application. Applications such imaging mass spectrometry (IMS) and biotyping are beginning to gain greater exposure and use; however, with limitations in optimization methods, producing the best result often relies on the ability to customize the physical characteristics of the instrumentation, a task that is challenging for most mass spectrometry laboratories. With this in mind, we have described the effect of making simple adjustments to the laser optics at the final collimating lens area, to adjust the laser beam size and shape in order to allow greater customization of the instrument for improving techniques such as IMS. We have therefore been able to demonstrate that improvements can be made without requiring the help of an electrical engineer or external funding in a way that only costs a small amount of time. Graphical Abstract ᅟ.

Lorentz laser-assisted stripping (Lolas) for H-/H0 injection into proton drivers

International Nuclear Information System (INIS)

Gastaldi, Ugo

2002-01-01

We discuss the main components of schemes for Lorentz laser-assisted stripping (abbreviated Lolas henceforth) proposed for injection into proton driver accumulators: H- → H0 + e- Lorentz stripping, H0→H0(n) laser excitation, H0(n)→p+ + e- Lorentz stripping. We mention results obtained in practice of H- beam transport and storage and of experiments addressing physics of the H- ion, of the H0 atom and of vacuum, which prove the feasibility of each Lolas component. For high enough injection energies, it is feasible to split without losses the H0 beam sent towards the accumulator into a fraction stripped to p+s and stored inside the accumulator and a complementary fraction of H0s delivered to high duty-cycle users. The fraction of stored beam can exceed 50% with one single Fabry-Perot cavity used to enhance the laser power density. Aspects of Lolas integration and optimization are pointed out

Laser projection positioning of spatial contour curves via a galvanometric scanner

Science.gov (United States)

Tu, Junchao; Zhang, Liyan

2018-04-01

The technology of laser projection positioning is widely applied in advanced manufacturing fields (e.g. composite plying, parts location and installation). In order to use it better, a laser projection positioning (LPP) system is designed and implemented. Firstly, the LPP system is built by a laser galvanometric scanning (LGS) system and a binocular vision system. Applying Single-hidden Layer Feed-forward Neural Network (SLFN), the system model is constructed next. Secondly, the LGS system and the binocular system, which are respectively independent, are integrated through a datadriven calibration method based on extreme learning machine (ELM) algorithm. Finally, a projection positioning method is proposed within the framework of the calibrated SLFN system model. A well-designed experiment is conducted to verify the viability and effectiveness of the proposed system. In addition, the accuracy of projection positioning are evaluated to show that the LPP system can achieves the good localization effect.

Ingenious Snake: An Adaptive Multi-Class Contours Extraction

Science.gov (United States)

Li, Baolin; Zhou, Shoujun

2018-04-01

Active contour model (ACM) plays an important role in computer vision and medical image application. The traditional ACMs were used to extract single-class of object contours. While, simultaneous extraction of multi-class of interesting contours (i.e., various contours with closed- or open-ended) have not been solved so far. Therefore, a novel ACM model named “Ingenious Snake” is proposed to adaptively extract these interesting contours. In the first place, the ridge-points are extracted based on the local phase measurement of gradient vector flow field; the consequential ridgelines initialization are automated with high speed. Secondly, the contours’ deformation and evolvement are implemented with the ingenious snake. In the experiments, the result from initialization, deformation and evolvement are compared with the existing methods. The quantitative evaluation of the structure extraction is satisfying with respect of effectiveness and accuracy.

Anterior and posterior capsule densitometry levels after femtosecond laser-assisted cataract surgery

Directory of Open Access Journals (Sweden)

Txomin Alberdi

2018-04-01

Full Text Available AIM: To analyze and compare five different variables over one year follow-up (1wk, 1, 3, 6 and 12mo: anterior capsule (AC, and posterior capsule (PC area densitometry values, AC and PC linear densitometry values, and AC opening area reduction ratio after femtosecond laser-assisted cataract surgery. METHODS: This was a prospective comparative study. Seventy-one patients underwent femtosecond laser-assisted cataract surgery on single eye between June 2014 and December 2015. A 5.0 mm diameter laser assisted anterior capsulotomy was performed on all eyes. In every post-surgery evaluation, AC opacificaction (ACO and PC opacification (PCO density levels were provided by Oculus Pentacam®HR using area and linear densitometry methods. Digital images were captured with a slit-lamp Topcon photographic camera and IMAGEnet® 5 software. The AC opening area on the digital images was measured using the Sketchandcalc area calculator and converted to reduction ratio levels. RESULTS: Using Pearson correlation coefficient (PCC, we found no correlation (r=-0.091, P=0.46 in the twelfth month assessment between the evolution of ACO area densitometry values and PCO area densitometry values considered as independent variables. We found no correlation, using PCC (r=-0.096, P=0.43 between the evolution of ACO linear densitometry values and PCO linear densitometry values, in the twelfth month visit, working both as independent variables. AC linear densitometry levels and AC area densitometry levels continued to grow strongly from sixth to twelfth months. Analysis of the values of AC opening area reduction ratio (1wk, 1, 3, 6, 12mo revealed statistically significant differences between the values of successive examinations but the magnitude of the change decreased. In the final period of monitoring between six and twelve months the magnitude of change was low. CONCLUSION: Our results show strong increases of Scheimpflug ACO densitometry values from the sixth to the

Photoluminescence of Eu-doped LiYF4 thin films grown by pulsed laser deposition and matrix-assisted pulsed laser evaporation

International Nuclear Information System (INIS)

Stokker-Cheregi, F; Matei, A; Dinescu, M; Secu, C E; Secu, M

2014-01-01

Matrix-assisted pulsed laser evaporation (MAPLE) has been investigated as an alternative to the pulsed laser deposition (PLD) technique for Eu 3+ -doped crystalline LiYF 4 thin-films deposition. MAPLE assumes laser ablation of a frozen target made of the material of interest diluted in a solvent, rather than that of a bulk target, of either pressed powder or single crystal, used in the case of PLD. Our approach stems from the assumption that laser ablation of a frozen dilute target would result in thin films with improved morphology, as compared to PLD. Indeed, we find that roughness values of samples obtained by the MAPLE technique are four times lower than in the case of PLD. A lower transmittance was noticed for PLD obtained layers with respect to those grown by MAPLE due to strong scattering of light by the morphological defects. Photoluminescence spectra are showing characteristic Eu 3+ -ion luminescence bands at 578, 591, 612, 650 and 698 nm ( 5 D 0  →  7 F J ); crystal field splitting of the bands indicates dopant ions incorporation in the host material during transfer by either PLD or MAPLE. (paper)

[Facial nerve neurinomas].

Science.gov (United States)

Sokołowski, Jacek; Bartoszewicz, Robert; Morawski, Krzysztof; Jamróz, Barbara; Niemczyk, Kazimierz

2013-01-01

Evaluation of diagnostic, surgical technique, treatment results facial nerve neurinomas and its comparison with literature was the main purpose of this study. Seven cases of patients (2005-2011) with facial nerve schwannomas were included to retrospective analysis in the Department of Otolaryngology, Medical University of Warsaw. All patients were assessed with history of the disease, physical examination, hearing tests, computed tomography and/or magnetic resonance imaging, electronystagmography. Cases were observed in the direction of potential complications and recurrences. Neurinoma of the facial nerve occurred in the vertical segment (n=2), facial nerve geniculum (n=1) and the internal auditory canal (n=4). The symptoms observed in patients were analyzed: facial nerve paresis (n=3), hearing loss (n=2), dizziness (n=1). Magnetic resonance imaging and computed tomography allowed to confirm the presence of the tumor and to assess its staging. Schwannoma of the facial nerve has been surgically removed using the middle fossa approach (n=5) and by antromastoidectomy (n=2). Anatomical continuity of the facial nerve was achieved in 3 cases. In the twelve months after surgery, facial nerve paresis was rated at level II-III° HB. There was no recurrence of the tumor in radiological observation. Facial nerve neurinoma is a rare tumor. Currently surgical techniques allow in most cases, the radical removing of the lesion and reconstruction of the VII nerve function. The rate of recurrence is low. A tumor of the facial nerve should be considered in the differential diagnosis of nerve VII paresis. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

Contralateral botulinum toxin injection to improve facial asymmetry after acute facial paralysis.

Science.gov (United States)

Kim, Jin

2013-02-01

The application of botulinum toxin to the healthy side of the face in patients with long-standing facial paralysis has been shown to be a minimally invasive technique that improves facial symmetry at rest and during facial motion, but our experience using botulinum toxin therapy for facial sequelae prompted the idea that botulinum toxin might be useful in acute cases of facial paralysis, leading to improve facial asymmetry. In cases in which medical or surgical treatment options are limited because of existing medical problems or advanced age, most patients with acute facial palsy are advised to await spontaneous recovery or are informed that no effective intervention exists. The purpose of this study was to evaluate the effect of botulinum toxin treatment for facial asymmetry in 18 patients after acute facial palsy who could not be optimally treated by medical or surgical management because of severe medical or other problems. From 2009 to 2011, nine patients with Bell's palsy, 5 with herpes zoster oticus and 4 with traumatic facial palsy (10 men and 8 women; age range, 22-82 yr; mean, 50.8 yr) participated in this study. Botulinum toxin A (Botox; Allergan Incorporated, Irvine, CA, USA) was injected using a tuberculin syringe with a 27-gauge needle. The amount injected per site varied from 2.5 to 3 U, and the total dose used per patient was 32 to 68 U (mean, 47.5 +/- 8.4 U). After administration of a single dose of botulinum toxin A on the nonparalyzed side of 18 patients with acute facial paralysis, marked relief of facial asymmetry was observed in 8 patients within 1 month of injection. Decreased facial asymmetry and strengthened facial function on the paralyzed side led to an increased HB and SB grade within 6 months after injection. Use of botulinum toxin after acute facial palsy cases is of great value. Such therapy decreases the relative hyperkinesis contralateral to the paralysis, leading to greater symmetric function. Especially in patients with medical

Low level constraints on dynamic contour path integration.

Directory of Open Access Journals (Sweden)

Sophie Hall

Full Text Available Contour integration is a fundamental visual process. The constraints on integrating discrete contour elements and the associated neural mechanisms have typically been investigated using static contour paths. However, in our dynamic natural environment objects and scenes vary over space and time. With the aim of investigating the parameters affecting spatiotemporal contour path integration, we measured human contrast detection performance of a briefly presented foveal target embedded in dynamic collinear stimulus sequences (comprising five short 'predictor' bars appearing consecutively towards the fovea, followed by the 'target' bar in four experiments. The data showed that participants' target detection performance was relatively unchanged when individual contour elements were separated by up to 2° spatial gap or 200 ms temporal gap. Randomising the luminance contrast or colour of the predictors, on the other hand, had similar detrimental effect on grouping dynamic contour path and subsequent target detection performance. Randomising the orientation of the predictors reduced target detection performance greater than introducing misalignment relative to the contour path. The results suggest that the visual system integrates dynamic path elements to bias target detection even when the continuity of path is disrupted in terms of spatial (2°, temporal (200 ms, colour (over 10 colours and luminance (-25% to 25% information. We discuss how the findings can be largely reconciled within the functioning of V1 horizontal connections.

Rejuvenecimiento facial

Directory of Open Access Journals (Sweden)

L. Daniel Jacubovsky, Dr.

2010-01-01

Full Text Available El envejecimiento facial es un proceso único y particular a cada individuo y está regido en especial por su carga genética. El lifting facial es una compleja técnica desarrollada en nuestra especialidad desde principios de siglo, para revertir los principales signos de este proceso. Los factores secundarios que gravitan en el envejecimiento facial son múltiples y por ello las ritidectomías o lifting cérvico faciales descritas han buscado corregir los cambios fisonómicos del envejecimiento excursionando, como se describe, en todos los planos tisulares involucrados. Esta cirugía por lo tanto, exige conocimiento cabal de la anatomía quirúrgica, pericia y experiencia para reducir las complicaciones, estigmas quirúrgicos y revisiones secundarias. La ridectomía facial ha evolucionado hacia un procedimiento más simple, de incisiones más cortas y disecciones menos extensas. Las suspensiones musculares han variado en su ejecución y los vectores de montaje y resección cutánea son cruciales en los resultados estéticos de la cirugía cérvico facial. Hoy estos vectores son de tracción más vertical. La corrección de la flaccidez va acompañada de un interés en reponer el volumen de la superficie del rostro, en especial el tercio medio. Las técnicas quirúrgicas de rejuvenecimiento, en especial el lifting facial, exigen una planificación para cada paciente. Las técnicas adjuntas al lifting, como blefaroplastias, mentoplastía, lipoaspiración de cuello, implantes faciales y otras, también han tenido una positiva evolución hacia la reducción de riesgos y mejor éxito estético.

Long-pulsed dye laser versus long-pulsed dye laser-assisted photodynamic therapy for acne vulgaris: A randomized controlled trial

DEFF Research Database (Denmark)

Haedersdal, M.; Togsverd, K.; Wiegell, S.R.

2008-01-01

Background: Long-pulsed dye laser (LPDL)-assisted photodynamic therapy has been suggested to be superior to laser alone for acne vulgaris but no evidence is available. Objective: To evaluate the efficacy and safety of LPDL alone versus LPDL in photodynamic therapy with methylaminolevulinic acid...... (MAL-LPDL) for acne vulgaris. Methods: Fifteen patients received a series of 3 full-face LPDL treatments and half-face prelaser MAL treatments; the latter being randomly assigned to the left or right side. Results: Inflammatory lesions were reduced more on MAL-LPDL-treated than on LPDL-treated sides...... to draw conclusions about the efficacy of the LPDL, only about the efficacy of MAL-LPDL compared with LPDL alone. Conclusions: MAL-LPDL is slightly superior to LPDL for the treatment of inflammatory acne Udgivelsesdato: 2008/3...

Rapid selective metal patterning on polydimethylsiloxane (PDMS) fabricated by capillarity-assisted laser direct write

KAUST Repository

Lee, Ming-Tsang

2011-08-12

In this study we demonstrate a novel approach for the rapid fabricating micro scale metal (silver) patterning directly on a polydimethylsiloxane (PDMS) substrate. Silver nanoparticles were sintered on PDMS to form conductive metal films using laser direct write (LDW) technology. To achieve good metal film quality, a capillarity-assisted laser direct writing (CALDW) of nanoparticle suspensions on a low surface energy material (PDMS) was utilized. Experimental results showed controllable electrical conductivities and good film properties of the sintered silver patterns. This study reveals an advanced method of metal patterning on PDMS, and proposes a new research application of LDW in a nanoparticle colloidal environment. © 2011 IOP Publishing Ltd.

Spatial profile of contours inducing long-range color assimilation.

Science.gov (United States)

Devinck, Frédéric; Spillmann, Lothar; Werner, John S

2006-01-01

Color induction was measured using a matching method for two spatial patterns, each composed of double contours. In one pattern (the standard), the contours had sharp edges to induce the Watercolor Effect (WCE); in the other, the two contours had a spatial taper so that the overall profile produced a sawtooth edge, or ramped stimulus. These patterns were chosen based on our previous study demonstrating that the strength of the chromatic WCE depends on a luminance difference between the two contours. Low-pass chromatic mechanisms, unlike bandpass luminance mechanisms, may be expected to be insensitive to the difference between the two spatial profiles. The strength of the watercolor spreading was similar for the two patterns at narrow widths of the contour possibly because of chromatic aberration, but with wider contours, the standard stimulus produced stronger assimilation than the ramped stimulus. This research suggests that luminance-dependent chromatic mechanisms mediate the WCE and that these mechanisms are sensitive to differences in the two spatial profiles of the pattern contours only when they are wide.

Optical shaping of a nano-scale tip by femtosecond laser assisted field evaporation

Science.gov (United States)

Di Russo, E.; Houard, J.; Langolff, V.; Moldovan, S.; Rigutti, L.; Deconihout, B.; Blavette, D.; Bogdanowicz, J.; Vella, A.

2018-04-01

We have investigated the morphology of a nanotip under femtosecond laser pulse illumination and a high electric field. We show that both the symmetry and the local radius of the tip change with the direction of laser polarization as against the tip axis. The experiments were performed on the very same GaN nanotip by laser-assisted atom probe tomography and electron tomography. This allowed an accurate assessment of the tip features by following the order of evaporation of single atoms from the surface. A change of atom emission sites was observed when a change of the angle between the tip axis and the linearly polarized electric field of the laser was imposed. This enables an optical control of field-evaporation sites. A close optical control of the tip morphology on a scale below 10 nm is thus achievable. Calculations of the field at nanotip apex and absorption maps support the experimental observations. Based on the present study, methods can be developed for reshaping nanotips at the nanometer level. This finding opens perspectives for numerous applications, making use of nanotips as probes or field emitters, and for plasmonic devices.

Resurfacing of Facial Acne Scars With a New Variable-Pulsed Er:YAG Laser in Fitzpatrick Skin Types IV and V.

Science.gov (United States)

Chathra, Namitha; Mysore, Venkataram

2018-01-01

The Er:YAG laser, considered to be less effective than CO 2 laser in its traditional form, in its new modulated version has variable pulse technology that is claimed to be superior to the earlier versions of the laser. The aim of the study was to check efficacy and safety of the new variable square pulse (VSP) Er:YAG laser in the management of acne scar in patients with Fitzpatrick skin types IV and V. This retrospective study consisted of 80 patients (Fitzpatrick skin types IV and V) with atrophic and hypertrophic facial acne scars. Records of the patients who had undergone four treatment sessions with VSP technology equipped with Er:YAG laser were extracted. Each patient had undergone a minimum of four sessions. Fractional mode at medium laser pulse (SP) and long pulse (LP) was employed for the depressed center of the scars to stimulate neocollagenogenesis. Short laser pulse (MSP) in nonfractionated mode was used for ablating the raised scar border and hypertrophic scars. Goodman and Baron global scarring grading system was used for qualitative and quantitative assessments. Patient's satisfaction to the treatment and observer's assessment of improvement (based on photographs) was graded as poor (75% improvement). At the end of the four sessions, the number of patients in grade IV postacne scarring reduced from 16 to 2 and that in grade III from 47 to 29. The mean score significantly dropped from 36.94 to 27.5. Subjective assessment revealed that 78 of 80 patients had noticed more than 25% improvement, with 50 of them showing more than 50% improvement at the end of four sessions. Eight patients perceived an excellent response and 42 reported a good response. This is notably higher than the observer's grading, which showed an excellent response in only 2 patients and a good response in 35. Adverse effects were limited to prolonged erythema (two patients), prolonged crusting (one patient), and postinflammatory hyperpigmentation (one patient). Ninety-seven percent of

The influence of assist gas on magnetic properties of electrotechnical steel sheets cut with laser

International Nuclear Information System (INIS)

Gaworska-Koniarek, Dominika; Szubzda, Bronislaw; Wilczynski, Wieslaw; Drosik, Jerzy; Karas, Kazimierz

2011-01-01

The paper presents the influence of assist gas (air and nitrogen) during laser cutting on magnetization, magnetic permeability and loss characteristics of non-oriented electrical steels. The research was made on an non-oriented M330-50A grade electrical steels by means of single sheet tester. In order to enhance the effect of cutting and the same degradation zone on magnetic properties, strips with different width were achieved. Measurements results indicate that application of air as assist gas has more destructive effect on magnetic properties of electrical steels than nitrogen one.

The influence of assist gas on magnetic properties of electrotechnical steel sheets cut with laser

Science.gov (United States)

Gaworska-Koniarek, Dominika; Szubzda, Bronisław; Wilczyński, Wiesław; Drosik, Jerzy; Karaś, Kazimierz

2011-07-01

The paper presents the influence of assist gas (air and nitrogen) during laser cutting on magnetization, magnetic permeability and loss characteristics of non-oriented electrical steels. The research was made on an non-oriented M330-50A grade electrical steels by means of single sheet tester. In order to enhance the effect of cutting and the same degradation zone on magnetic properties, strips with different width were achieved. Measurements results indicate that application of air as assist gas has more destructive effect on magnetic properties of electrical steels than nitrogen one.

Quantitative facial asymmetry: using three-dimensional photogrammetry to measure baseline facial surface symmetry.

Science.gov (United States)

Taylor, Helena O; Morrison, Clinton S; Linden, Olivia; Phillips, Benjamin; Chang, Johnny; Byrne, Margaret E; Sullivan, Stephen R; Forrest, Christopher R

2014-01-01

Although symmetry is hailed as a fundamental goal of aesthetic and reconstructive surgery, our tools for measuring this outcome have been limited and subjective. With the advent of three-dimensional photogrammetry, surface geometry can be captured, manipulated, and measured quantitatively. Until now, few normative data existed with regard to facial surface symmetry. Here, we present a method for reproducibly calculating overall facial symmetry and present normative data on 100 subjects. We enrolled 100 volunteers who underwent three-dimensional photogrammetry of their faces in repose. We collected demographic data on age, sex, and race and subjectively scored facial symmetry. We calculated the root mean square deviation (RMSD) between the native and reflected faces, reflecting about a plane of maximum symmetry. We analyzed the interobserver reliability of the subjective assessment of facial asymmetry and the quantitative measurements and compared the subjective and objective values. We also classified areas of greatest asymmetry as localized to the upper, middle, or lower facial thirds. This cluster of normative data was compared with a group of patients with subtle but increasing amounts of facial asymmetry. We imaged 100 subjects by three-dimensional photogrammetry. There was a poor interobserver correlation between subjective assessments of asymmetry (r = 0.56). There was a high interobserver reliability for quantitative measurements of facial symmetry RMSD calculations (r = 0.91-0.95). The mean RMSD for this normative population was found to be 0.80 ± 0.24 mm. Areas of greatest asymmetry were distributed as follows: 10% upper facial third, 49% central facial third, and 41% lower facial third. Precise measurement permitted discrimination of subtle facial asymmetry within this normative group and distinguished norms from patients with subtle facial asymmetry, with placement of RMSDs along an asymmetry ruler. Facial surface symmetry, which is poorly assessed

Holmium laser assisted ′anatomical′ enucleation of adenoma of benign hyperplasia of prostate

Directory of Open Access Journals (Sweden)

Shivadeo S Bapat

2006-01-01

Full Text Available Aims: To present our technique of Holmium Laser assisted "ANATOMICAL" enucleation of the benign prostatic adenoma (HoLEP in 219 patients. Procedure is based on the principle of digital enucleation of the adenoma from its surgical capsule, but performed entirely by perurethral endoscopic technique assisted by Holmium Laser. Materials and Methods: From March 2001 to November 2004, 219 patients under went HoLEP. After the initial cuts from bladder neck to verumontanum at 5 and 7 o′clock position, capsule is identified. The beak of the resectoscope sheath was inserted in the plane between the capsule and the adenoma and the adenoma was physically pushed away towards the urethra from the capsule. Laser was used to coagulate the bleeders, to cut the mucosal attachments and tough stromal tissue. Procedure was repeated for median and two lateral lobes. There was minimal bleeding and fluid absorption. Complications were few. Results: In 206 cases successful enucleation of the adenoma was carried out. First 13 cases formed part of the learning curve and were completed by standard transurethral resection of prostate (TURP. IPSS score dropped from average of 23 to 8 and peak flow improved from 20. No patient had postoperative urinary incontinence or stricture. Conclusions: HoLEP is an effective alternative to TURP. Ultimate end results replicate the end results of open enucleation of BPH without its morbidity and have all the advantages of endoscopic surgery. It offers distinct advantages over standard TURP as the incidence of blood transfusion and fluid absorption are greatly minimized.

Observation of a laser-assisted ionization of the He(21S,23S)+He(11S) collision system involving a bound-free transition

International Nuclear Information System (INIS)

Pradel, P.; Monchicourt, P.; Dubreuil, D.; Heuze, J.; Laucagne, J.J.; Spiess, G.

1985-01-01

We report the first observation of an assisted He + yield arising from single collisions between a He(2 1 S,2 3 S) atom beam on a He(1 1 S) target in the presence of an intense laser field. A time-of-flight analysis shows that the pulsed laser-assisted ion signal is reproducible, energy dependent, and appears in addition to the continuous ion flux coming from a known field-free diabatic channel. From the estimated value of the diabatic ionization cross section sigma/sub d/, the order of magnitude of the assisted-ionization cross section sigma/sub a/ is given

Method of surface error visualization using laser 3D projection technology

Science.gov (United States)

Guo, Lili; Li, Lijuan; Lin, Xuezhu

2017-10-01

In the process of manufacturing large components, such as aerospace, automobile and shipping industry, some important mold or stamped metal plate requires precise forming on the surface, which usually needs to be verified, if necessary, the surface needs to be corrected and reprocessed. In order to make the correction of the machined surface more convenient, this paper proposes a method based on Laser 3D projection system, this method uses the contour form of terrain contour, directly showing the deviation between the actually measured data and the theoretical mathematical model (CAD) on the measured surface. First, measure the machined surface to get the point cloud data and the formation of triangular mesh; secondly, through coordinate transformation, unify the point cloud data to the theoretical model and calculate the three-dimensional deviation, according to the sign (positive or negative) and size of the deviation, use the color deviation band to denote the deviation of three-dimensional; then, use three-dimensional contour lines to draw and represent every coordinates deviation band, creating the projection files; finally, import the projection files into the laser projector, and make the contour line projected to the processed file with 1:1 in the form of a laser beam, compare the Full-color 3D deviation map with the projection graph, then, locate and make quantitative correction to meet the processing precision requirements. It can display the trend of the machined surface deviation clearly.

Fractional laser-assisted drug delivery

DEFF Research Database (Denmark)

Erlendsson, Andrés M; Doukas, Apostolos G; Farinelli, William A

2016-01-01

BACKGROUND AND OBJECTIVE: Ablative fractional laser (AFXL) is rapidly evolving as one of the foremost techniques for cutaneous drug delivery. While AFXL has effectively improved topical drug-induced clearance rates of actinic keratosis, treatment of basal cell carcinomas (BCCs) has been challenging......, potentially due to insufficient drug uptake in deeper skin layers. This study sought to investigate a standardized method to actively fill laser-generated channels by altering pressure, vacuum, and pressure (PVP), enquiring its effect on (i) relative filling of individual laser channels; (ii) cutaneous...

Ghost peaks observed after atmospheric pressure matrix-assisted laser desorption/ionization experiments may disclose new ionization mechanism of matrix-assisted hypersonic velocity impact ionization.

Science.gov (United States)

Moskovets, Eugene

2015-08-30

Understanding the mechanisms of matrix-assisted laser desorption/ionization (MALDI) promises improvements in the sensitivity and specificity of many established applications in the field of mass spectrometry. This paper reports a serendipitous observation of a significant ion yield in a post-ionization experiment conducted after the sample had been removed from a standard atmospheric pressure (AP)-MALDI source. This post-ionization is interpreted in terms of collisions of microparticles moving with a hypersonic velocity into a solid surface. Calculations show that the thermal energy released during such collisions is close to that absorbed by the top matrix layer in traditional MALDI. The microparticles, containing both the matrix and analytes, could be detached from a film produced inside the inlet capillary during the sample ablation and accelerated by the flow rushing through the capillary. These observations contribute some new perspective to ion formation in both laser and laser-less matrix-assisted ionization. An AP-MALDI ion source hyphenated with a three-stage high-pressure ion funnel system was utilized for peptide mass analysis. After the laser had been turned off and the MALDI sample removed, ions were detected during a gradual reduction of the background pressure in the first funnel. The constant-rate pressure reduction led to the reproducible appearance of different singly and doubly charged peptide peaks in mass spectra taken a few seconds after the end of the MALDI analysis of a dried-droplet spot. The ion yield as well as the mass range of ions observed with a significant delay after a completion of the primary MALDI analysis depended primarily on the background pressure inside the first funnel. The production of ions in this post-ionization step was exclusively observed during the pressure drop. A lower matrix background and significant increase in relative yield of double-protonated ions are reported. The observations were partially consistent

Asians' Facial Responsiveness to Basic Tastes by Automated Facial Expression Analysis System.

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Zhi, Ruicong; Cao, Lianyu; Cao, Gang

2017-03-01

Growing evidence shows that consumer choices in real life are mostly driven by unconscious mechanisms rather than conscious. The unconscious process could be measured by behavioral measurements. This study aims to apply automatic facial expression analysis technique for consumers' emotion representation, and explore the relationships between sensory perception and facial responses. Basic taste solutions (sourness, sweetness, bitterness, umami, and saltiness) with 6 levels plus water were used, which could cover most of the tastes found in food and drink. The other contribution of this study is to analyze the characteristics of facial expressions and correlation between facial expressions and perceptive hedonic liking for Asian consumers. Up until now, the facial expression application researches only reported for western consumers, while few related researches investigated the facial responses during food consuming for Asian consumers. Experimental results indicated that facial expressions could identify different stimuli with various concentrations and different hedonic levels. The perceived liking increased at lower concentrations and decreased at higher concentrations, while samples with medium concentrations were perceived as the most pleasant except sweetness and bitterness. High correlations were founded between perceived intensities of bitterness, umami, saltiness, and facial reactions of disgust and fear. Facial expression disgust and anger could characterize emotion "dislike," and happiness could characterize emotion "like," while neutral could represent "neither like nor dislike." The identified facial expressions agree with the perceived sensory emotions elicited by basic taste solutions. The correlation analysis between hedonic levels and facial expression intensities obtained in this study are in accordance with that discussed for western consumers. © 2017 Institute of Food Technologists®.

Launch and capture of a single particle in a pulse-laser-assisted dual-beam fiber-optic trap

Science.gov (United States)

Fu, Zhenhai; She, Xuan; Li, Nan; Hu, Huizhu

2018-06-01

The rapid loading and manipulation of microspheres in optical trap is important for its applications in optomechanics and precision force sensing. We investigate the microsphere behavior under coaction of a dual-beam fiber-optic trap and a pulse laser beam, which reveals a launched microsphere can be effectively captured in a spatial region. A suitable order of pulse duration for launch is derived according to the calculated detachment energy threshold of pulse laser. Furthermore, we illustrate the effect of structural parameters on the launching process, including the spot size of pulse laser, the vertical displacement of beam waist and the initial position of microsphere. Our result will be instructive in the optimal design of the pulse-laser-assisted optical tweezers for controllable loading mechanism of optical trap.