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Sample records for relaxing incision knife

  1. Effect of blade configuration, knife action, and intraocular pressure on keratotomy incision depth and shape.

    PubMed

    Melles, G R; Wijdh, R H; Cost, B; Beekhuis, W H; Binder, P S; van Rij, G; Groot, K

    1993-07-01

    For the same diamond blade extension, uphill (centripetal) radial keratotomy incision direction achieves greater depth and consequently greater refractive effect than downhill (centrifugal) incisions. To determine which factors may account for this difference, two uphill and two downhill incisions were made with a double-edged diamond blade set to 90% central pachometry in 26 human donor eyes at 15 or 60 mm Hg. Uphill incisions made with the perpendicular blade had greater mean incision depth than downhill incisions made with the oblique blade at 15 mm Hg (83.6 +/- 3.9% and 68.2 +/- 5.2%) (p < 0.0005) and at 60 mm Hg (86.3 +/- 3.1% and 79.7 +/- 1.7%) (p < 0.0005). Uphill and downhill incisions both made with the perpendicular blade had equal depth (85.4 +/- 4.9% and 83.7 +/- 3.5%) (p > 0.1). The perpendicular blade edge created a straight, and the oblique edge an S- or J-shaped, histological incision configuration. Corneal profile pictures taken during each incision showed the knife to tilt opposite of the incision direction and to move at a constant angle to the limbal plane, producing a smaller optical clear zone (OCZ) in the posterior stroma than intended with uphill incisions. Greater refractive effect with uphill incisions may be explained by the perpendicular blade being more effective in incising corneal lamellae, and the creation of a smaller posterior OCZ. Intraocular pressure variations during surgery may affect achieved incision depth of downhill, but not of uphill, incisions. PMID:8339558

  2. A case of endophthalmitis associated with limbal relaxing incision

    PubMed Central

    Haripriya, Aravind; Syeda, Taranum S

    2012-01-01

    Limbal relaxing incisions (LRIs) are considered a relatively safe procedure with rapid stabilization and absence of infectious complications. Do we need to readdress this last impression? We report a case of nocardia endophthalmitis associated with an exudate at the site of an LRI in a patient who underwent routine cataract surgery. This case, to the best of our knowledge, is the first report of its kind, stressing the need for a cautious approach to the adoption of this method of astigmatic correction. PMID:22569388

  3. A stab in the dark: Design and construction of a novel device for conducting incised knife trauma investigations and its initial test.

    PubMed

    Humphrey, Caitlin; Kumaratilake, Jaliya; Henneberg, Maciej

    2016-05-01

    Knife attacks are commonly seen in Australia and other countries. During forensic investigations the force with which a wound was inflicted is often questioned. The ability to examine resultant trauma and particular weapons at different forces with an experimental device may lead to better interpretations of knife wounds. The objective of this study is to design, construct and test a device to analyse the characteristics and forces involved in knife attacks, particularly incised wounds. The mechanical variables (e.g. force, angle, knife geometry) involved in knife attacks have been considered to design and construct a suitable device which allows these variables to be systematically controlled and varied. A device was designed and constructed from mild steel. This included a pivoting arm and instrumented knife holder. The arm has adjustable angle and weight so that knives can be operated at different calculated forces. A device was successfully constructed and the repeatability of incised knife trauma and its characteristics in skeletal tissues were investigated. A device which allows reproducible and controlled experiments with knife wounds will be advantageous to forensic investigations. In particular, in determining forces and types of weapons associated with particular wounds, identifying or eliminating suspected weapons and more accurately answering the common question: How much force would be required to cause that particular wound. This could help to characterise the perpetrator. The device can be altered to be used in the future to investigate trauma caused by other weapons. PMID:27061866

  4. Factors Influencing Efficacy of Peripheral Corneal Relaxing Incisions during Cataract Surgery

    PubMed Central

    Hirnschall, Nino; Wiesinger, Jörg; Draschl, Petra; Findl, Oliver

    2015-01-01

    Purpose. To evaluate influencing factors on the residual astigmatism after performing peripheral corneal relaxing incisions (PCRIs) during cataract surgery. Methods. This prospective study included patients who were scheduled for cataract surgery with PCRIs. Optical biometry (IOLMaster 500, Carl Zeiss Meditec AG, Germany) was taken preoperatively, 1 week, 4 months, and 1 year postoperatively. Additionally, corneal topography (Atlas model 9000, Carl Zeiss Meditec AG, Germany), ORA (Ocular Response Analyzer, Reichert Ophthalmic Instruments, USA), and autorefraction (Autorefractometer RM 8800 Topcon) were performed postoperatively. Results. Mean age of the study population (n = 74) was 73.5 years (±9.3; range: 53 to 90) and mean corneal astigmatism preoperatively was −1.82 D (±0.59; 1.00 to 4.50). Mean corneal astigmatism was reduced to 1.14 D (±0.67; 0.11 to 3.89) 4 months postoperatively. A partial least squares regression showed that a high eccentricity of the cornea, a large deviation between keratometry and topography, and a high preoperative astigmatism resulted in a larger postoperative error concerning astigmatism. Conclusions. PCRI causes a reduction of preoperative astigmatism, though the prediction is difficult but several factors were found to be a relevant source of error. PMID:26199739

  5. Long-term outcomes of limbal relaxing incisions during cataract surgery: aberrometric analysis

    PubMed Central

    Monaco, Gaspare; Scialdone, Antonio

    2015-01-01

    Purpose To compare the final changes in corneal wavefront aberration by limbal relaxing incisions (LRIs) after cataract surgery. Methods This prospective cumulative interventional nonrandomized case study included cataract and astigmatic patients undergoing LRIs and phaco with intraocular lens implantation. LRIs were planned using Donnenfeld nomogram. The root mean square of corneal wave aberration for total Z(n,i)(1≤n≤8), astigmatism Z(2,±1), coma Z(3–5–7,±1), trefoil Z(3–5–7,±2), spherical Z(4–6–8,0), and higher-order aberration (HOA) Z(3≤n≤8) was examined before and 3 years after surgery (optical path difference-Scan II [OPD-Scan II)]. Uncorrected distance visual acuity and best-corrected distance visual acuity (CDVA) for distance, keratometric cylinder, and variations in average corneal power were also analyzed. Results Sixty-four eyes of 48 patients were included in the study. Age ranged from 42 to 92 years (70.6±8.4 years). After LRIs, uncorrected distance visual acuity and best-corrected distance visual acuity improved statistically (P<0.01). The keratometric cylinder value decreased by 40.1%, but analysis of KP90 and KP135 polar values did not show any decrease that could be statistically confirmed (P=0.22 and P=0.24). No significant changes were detected in root mean square of total (P=0.61) and HOAs (P=0.13) aberrations. LRIs did not induce alteration in central corneal power confirming a 1:1 coupling ratio. Conclusion LRIs determined a nonsignificant alteration of corneal HOA. Therefore, LRIs can be still considered a qualitatively viable mean in those cases where toric intraocular lenses are contraindicated or not available. Yet, the authors raise the question of nonpersonalized nomograms, as in the present study, LRIs did not reach the preset target cylinder. PMID:26357459

  6. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy

    PubMed Central

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  7. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy.

    PubMed

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  8. A Hot Knife Through Ice-Cream: Earthflow Response to Channel Incision (Or Channel Response to Earthflows?), Eel River Canyon, California

    NASA Astrophysics Data System (ADS)

    Mackey, B. H.; Roering, J. J.; McKean, J. A.

    2007-12-01

    Abundant glacier-like earthflow features are recognized as a primary erosional process in the highly erodable Franciscan Melange of the Eel River Basin, CA. Despite their prominence in this "melting ice-cream" topography, many questions regarding their effects on the long term sediment flux from this rapidly eroding basin remain unresolved. For example, does an earthflow's basal shear zone propagate vertically downwards with vertical river incision? What controls the upslope and lateral extent of individual earthflows? How does the erosive power of a river influence the rate of earthflow movement, or conversely do earthflow toe deposits regulate the rate of river incision? Here we present preliminary findings derived from study of 200km2 of lidar data (1m resolution) covering hillslopes adjacent to 30km of the Eel River. Lidar allows detailed analysis of the interaction between earthflows and the drainage network, and we document how inferred changes in local base level are propagated throughout adjacent hillslopes via earthflow movement. The most active earthflows (determined by field surveying and analysis of aerial photos rectified using lidar- generated digital topography) coincide with locally steep sections of channel, while downstream of the most active flows we frequently observe less-active or dormant earthflows. This observation supports the idea that the locations of the most active earthflows coincide with headward propagating knickpoints in the channel. The rate of earthflow movement appears to slow when an earthflow exhausts the upslope area of easily mobilized sediment. Earthflow toes can protrude directly into the channel, causing the channel to narrow and steepen, and even undercut the opposite bank. Large resistant boulders (>2m diameter) transported by the earthflow accumulate in the streambed and appear to both act as a check on further channel incision and earthflow movement. In contrast, areas adjacent to active earthflows exhibit smooth

  9. Use of a Toric Intraocular Lens and a Limbal-Relaxing Incision for the Management of Astigmatism in Combined Glaucoma and Cataract Surgery

    PubMed Central

    Gibbons, Allister

    2016-01-01

    Purpose We report the surgical management of a patient with glaucoma undergoing cataract surgery with high preexisting astigmatism. A combination of techniques was employed for her astigmatism management. Methods A 76-year-old female with 5.5 dpt of corneal astigmatism underwent surgery in her left eye consisting of one-site trabeculectomy, phacoemulsification, toric intraocular lens implantation and a single inferior limbal-relaxing incision. Results Intraocular pressure control was achieved with no medication at 11 mm Hg; before the filtering procedure, the pressure was 16 mm Hg on two topical drugs. Astigmatism was reduced to 0.75 dpt, and both corrected and uncorrected visual acuity improved. Conclusions Astigmatism management can have a good outcome in combined procedures. We encourage surgeons to address astigmatism in the preoperative planning of patients undergoing glaucoma surgery associated with phacoemulsification. PMID:27293408

  10. Bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes versus cold-knife transurethral incision for the treatment of posterior urethral stricture: a prospective, randomized study

    PubMed Central

    Cai, Wansong; Chen, Zhiyuan; Wen, Liping; Jiang, Xiangxin; Liu, Xiuheng

    2016-01-01

    OBJECTIVE: Evaluate the efficiency and safety of bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes for the treatment of posterior urethral stricture. Compare the outcomes following bipolar plasma vaporization with conventional cold-knife urethrotomy. METHODS: A randomized trial was performed to compare patient outcomes from the bipolar and cold-knife groups. All patients were assessed at 6 and 12 months postoperatively via urethrography and uroflowmetry. At the end of the first postoperative year, ureteroscopy was performed to evaluate the efficacy of the procedure. The mean follow-up time was 13.9 months (range: 12 to 21 months). If re-stenosis was not identified by both urethrography and ureteroscopy, the procedure was considered “successful”. RESULTS: Fifty-three male patients with posterior urethral strictures were selected and randomly divided into two groups: bipolar group (n=27) or cold-knife group (n=26). Patients in the bipolar group experienced a shorter operative time compared to the cold-knife group (23.45±7.64 hours vs 33.45±5.45 hours, respectively). The 12-month postoperative Qmax was faster in the bipolar group than in the cold-knife group (15.54±2.78 ml/sec vs 18.25±2.12 ml/sec, respectively). In the bipolar group, the recurrence-free rate was 81.5% at a mean follow-up time of 13.9 months. In the cold-knife group, the recurrence-free rate was 53.8%. CONCLUSIONS: The application of bipolar plasma-cutting and plasma-loop electrodes for the management of urethral stricture disease is a safe and reliable method that minimizes the morbidity of urethral stricture resection. The advantages include a lower recurrence rate and shorter operative time compared to the cold-knife technique. PMID:26872076

  11. Gamma Knife

    MedlinePlus

    ... results are sent to the Gamma Knife®'s planning computer system. Together, physicians ( radiation oncologists and neurosurgeons) and medical physicists delineate targets and normal anatomical structures. They use a planning computer program to determine the exact spatial relationship between ...

  12. Cold knife cone biopsy

    MedlinePlus

    A cold knife cone biopsy (conization) is surgery to remove a sample of abnormal tissue from the cervix. The ... Cold knife cone biopsy is done to detect cervical cancer or early changes that lead to cancer. ...

  13. Cold knife cone biopsy

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003910.htm Cold knife cone biopsy To use the sharing features on this page, please enable JavaScript. A cold knife cone biopsy (conization) is surgery to remove ...

  14. Incising Tibet

    NASA Astrophysics Data System (ADS)

    Yang, R.; Herman, F.; Fellin, M. G.; Willett, S.; Wang, W.

    2014-12-01

    Convergence between India and Eurasia has produced the Tibetan Plateau, which stands 5 km high over a region of 3 million km2,since collision at ~50 Ma. A key region for understanding the mechanisms and timing of uplift is the SE margin, where major rivers have incised the plateau margin, permitting the use of thermochronometry to time incision. Here we present new (U-Th)/He ages including 17 ages on apatite and 23 on zircon and 12 apatite fission track ages on the southeastern margins of the Plateau to explore rates and timing of incision. All three thermochronometric systems on the Salween suggest a regional change in the last 8 Myr and exhibit progressive younging over ~ 150 km upstream. Apatite (U-Th)/He ages of valley bottom samples from the Mekong become younger upstream whereas apatite fission-track and zircon (U-Th)/He ages show a large scatter from ~ 5 Ma to ~160 Ma, depending on the distance above the thalweg. Similarly, upstream samples north of 290N on the Yangtze yield much younger ages than downstream samples. Inversion of combined thermochronometers reveals a northward propagation of the highest rates of incision along the Salween and Mekong since 8 Ma. These results, together with analysis of river profiles, are best explained by a scenario of plateau incision that occurred in southeastern Tibet before or coeval at 8 Ma. We infer that the southeastern plateau margin was deformed under a complex context with both lateral expansion of the plateau margin and oblique indenting of the India plate localizing shortening and high uplift rates at the corner of the indenter.

  15. The Shoemaker's Knife

    ERIC Educational Resources Information Center

    Thomson, Ian

    2010-01-01

    Archimedes, the famous Greek mathematician, lived from 287 BCE until approximately 212 BCE. He thought that the figure of two semi-circles on a straight line enclosed by a larger semi-circle resembled a shoemaker's knife. Archimedes called this figure an "arbelos" since arbelos is the Greek word for a shoemaker's knife. The author describes the…

  16. Dynamic gamma knife radiosurgery

    NASA Astrophysics Data System (ADS)

    Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

    2009-03-01

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C™ and Perfexion™ units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the

  17. Pleuroscopic punch biopsy using insulated-tip diathermic knife-2 for the diagnosis of desmoplastic malignant mesothelioma.

    PubMed

    Masai, Kyohei; Sasada, Shinji; Izumo, Takehiro; Taniyama, Tomoko; Nakamura, Yukiko; Chavez, Christine; Sakurai, Hiroyuki; Tsuta, Koji; Tsuchida, Takaaki

    2013-10-01

    Desmoplastic malignant mesothelioma (DMM) is a rare subtype of malignant pleural mesothelioma (MPM) and is often difficult to distinguish from pleural fibrosis and reactive mesothelial hyperplasia, especially if the biopsy samples are small. We performed full-thickness pleural biopsy on a lesion suspected to be DMM using an insulated-tip diathermic knife-2 (IT knife-2) during flex-rigid pleuroscopy. IT knife-2 is a novel electrosurgical device for endoscopic submucosal dissection in the early gastrointestinal cancer. It consists of a needle knife with 3 short blades at the distal end attached to an insulated ceramic tip. A 54-year-old man presenting with chest wall mass and thickened pleura, in whom a computed tomography-guided percutaneous needle aspiration had remained negative, underwent flex-rigid pleuroscopy for definitive diagnosis. While applying electric current, we used the IT knife-2 to incise the pleura in a circular shape just above the endothoracic fascia. The incised pleura was removed by forceps and examined pathologically. The microscopic examination was compatible with DMM. We discovered that pleuroscopic punch biopsy using IT knife-2 can diagnose DMM. Use of IT knife-2 during flex-rigid pleuroscopy can obtain sufficient samples from densely thickened pleura, which is difficult to diagnose with small biopsies. PMID:24162121

  18. The Knife Machine. Module 15.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on the knife machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers one topic: performing special operations on the knife machine (a single needle or multi-needle machine which sews and cuts at the same time). These components are provided: an introduction, directions, an objective,…

  19. Stereotactic radiosurgery - CyberKnife

    MedlinePlus

    ... slides into a machine that delivers radiation. A robotic arm controlled by a computer moves around you. ... Accuray Incorporated. CyberKnife robotic radiosurgery system patient brochure. 2012. ... Accessed ...

  20. High grade anorectal stricture complicating Crohn's disease: endoscopic treatment using insulated-tip knife

    PubMed Central

    Chon, Hyung Ku; Shin, Ik Sang; Kim, Sang Wook

    2016-01-01

    Endoscopic treatments have emerged as an alternative to surgery, in the treatment of benign colorectal stricture. Unlike endoscopic balloon dilatation, there is limited data on endoscopic electrocautery incision therapy for benign colorectal stricture, especially with regards to safety and long-term patency. We present a case of a 29-year-old female with Crohn's disease who had difficulty in defecation and passing thin stools. A pelvic magnetic resonance imaging scan, gastrograffin enema, and sigmoidoscopy showed a high-grade anorectal stricture. An endoscopic insulated-tip knife incision was successfully performed to resolve the problem. From our experience, we suggest that endoscopic insulated-tip knife treatment may be a feasible and effective modality for patients with short-segment, very rigid, fibrotic anorectal stricture. PMID:27433152

  1. High grade anorectal stricture complicating Crohn's disease: endoscopic treatment using insulated-tip knife.

    PubMed

    Chon, Hyung Ku; Shin, Ik Sang; Kim, Sang Wook; Lee, Soo Teik

    2016-07-01

    Endoscopic treatments have emerged as an alternative to surgery, in the treatment of benign colorectal stricture. Unlike endoscopic balloon dilatation, there is limited data on endoscopic electrocautery incision therapy for benign colorectal stricture, especially with regards to safety and long-term patency. We present a case of a 29-year-old female with Crohn's disease who had difficulty in defecation and passing thin stools. A pelvic magnetic resonance imaging scan, gastrograffin enema, and sigmoidoscopy showed a high-grade anorectal stricture. An endoscopic insulated-tip knife incision was successfully performed to resolve the problem. From our experience, we suggest that endoscopic insulated-tip knife treatment may be a feasible and effective modality for patients with short-segment, very rigid, fibrotic anorectal stricture. PMID:27433152

  2. J incision in neck dissections.

    PubMed

    Acar, A; Dursun, G; Aydin, O; Akbaş, Y

    1998-01-01

    Metastasis in the neck lymph system of primary tumours of the head and neck is frequently seen. In order to prevent this metastasis, neck dissection is carried out by various types of skin incisions. In this study, types of skin incision used in neck dissections were defined, and the advantages, disadvantages and results of J incisions, which have been performed on 320 radical neck dissection patients in our clinic between 1985-1996, were compared with those of other incision types. PMID:9538447

  3. Intralesional Injection of Mitomycin C at Transurethral Incision of Bladder Neck Contracture May Offer Limited Benefit: TURNS Study Group

    PubMed Central

    Redshaw, Jeffrey D.; Broghammer, Joshua A.; Smith, Thomas G.; Voelzke, Bryan B.; Erickson, Bradley A.; McClung, Christopher D.; Elliott, Sean P.; Alsikafi, Nejd F.; Presson, Angela P.; Aberger, Michael E.; Craig, James R.; Brant, William O.; Myers, Jeremy B.

    2015-01-01

    Purpose Injection of mitomycin C may increase the success of transurethral incision of the bladder neck for the treatment of bladder neck contracture. We evaluated the efficacy of mitomycin C injection across multiple institutions. Materials and Methods Data on all patients who underwent transurethral incision of the bladder neck with mitomycin C from 2009 to 2014 were retrospectively reviewed from 6 centers in the TURNS. Patients with at least 3 months of cystoscopic followup were included in the analysis. Results A total of 66 patients underwent transurethral incision of the bladder neck with mitomycin C and 55 meeting the study inclusion criteria were analyzed. Mean ± SD patient age was 64 ± 7.6 years. Dilation or prior transurethral incision of the bladder neck failed in 80% (44 of 55) of patients. Overall 58% (32 of 55) of patients achieved resolution of bladder neck contracture after 1 transurethral incision of the bladder neck with mitomycin C at a median followup of 9.2 months (IQR 11.7). There were 23 patients who had recurrence at a median of 3.7 months (IQR 4.2), 15 who underwent repeat transurethral incision of the bladder neck with mitomycin C and 9 of 15 (60%) who were free of another recurrence at a median of 8.6 months (IQR 8.8), for an overall success rate of 75% (41 of 55). Incision with electrocautery (Collins knife) was predictive of success compared with cold knife incision (63% vs 50%, p=0.03). Four patients experienced serious adverse events related to mitomycin C and 3 needed or are planning cystectomy. Conclusions The efficacy of intralesional injection of mitomycin C at transurethral incision of the bladder neck was lower than previously reported and was associated with a 7% rate of serious adverse events. PMID:25200807

  4. Longitudinal relationship between incisal occlusion and incisal tooth wear.

    PubMed

    Silness, J; Johannessen, G; Røynstrand, T

    1993-02-01

    The purpose of the study was to evaluate the longitudinal relationship between incisal wear of central incisors and the size of vertical overbite (OB) and horizontal overjet (OJ). Stone casts of 51 subjects were used for the determinations. Casts were obtained when the subjects were 15 and 27 years old. Statistical analysis was performed with the t test for paired samples, the chi-square test of association. Pearson's product moment correlation coefficient, and Spearman's rank correlation coefficient. Both overbite and overjet diminished after 12 years, and incisal wear increased. It was concluded that increase in age, incisal wear, vertical overbite and incisal occlusion (OB/OJ) are clinical predictors of wear of maxillary and mandibular central incisors in adolescents. PMID:8451919

  5. Maintaining knife sharpness in industrial meat cutting: A matter of knife or meat cutter ability.

    PubMed

    Karltun, J; Vogel, K; Bergstrand, M; Eklund, J

    2016-09-01

    Knife sharpness is imperative in meat cutting. The aim of this study was to compare the impact of knife blade steel quality with meat cutters' individual ability to maintain the cutting edge sharp in an industrial production setting. Twelve meat cutters in two different companies using three different knives during normal production were studied in this quasi-experimental study. Methods included were measuring knife cutting force before and after knife use, time knives were used, ratings of sharpness and discomfort and interviews. Results showed that the meat cutters' skill of maintaining sharpness during work had a much larger effect on knife sharpness during work than the knife steel differences. The ability was also related to feelings of discomfort and to physical exertion. It was found that meat cutters using more knives were more likely to suffer from discomfort in the upper limbs, which is a risk for developing MSD. PMID:27184316

  6. A sharp knife for high temperatures

    NASA Technical Reports Server (NTRS)

    Heisman, R. M.; Iceland, W. F.

    1978-01-01

    Electrically heated nickel-chrome-steel alloy knife may be used to cut heat resistant plastic felt and similar materials with relative ease. Blade made of commercially available alloy RA 330 retains edge at temperatures as high as 927 C.

  7. Incisal orientation and biting efficiency.

    PubMed

    Ang, K Y; Lucas, Peter W; Tan, H T W

    2006-06-01

    Broad-edged 'spatulate' upper and lower incisors are distinctive of catarrhines and platyrrhines who use them in various ways to peel fruits, remove bark, and strip leaves from branches. The incisors of modern humans not only control the bite size of foods during ingestion, but often grip items in a number of non-food related tasks. Such uses have long been implicated for Neandertals as well. Despite the evolutionary importance of incision and the fact that the incisors feature prominently in clinical dentistry (via orthodontic practices designed both to correct incisal misalignments and adjust their orientation), little is known about what affects their functional efficiency. Few mechanical analyses of incisal action have been published and none that seem to take note of the mechanisms of both fracture and friction at the tooth-food interface. Here, we modeled the incisal tip as a wedge, finding that the efficiency of biting foods that fracture elastically is strongly dependent on both the apex angle of the incisor and the coefficient of friction. Based on apex angle measurements from a small sample of human central incisors, the overall efficiency of upper central incisors is predicted to be greatest when the angle between the apex bisector and the direction of applied force is zero. However, this is complicated greatly by friction, particularly for the lower incisors. The analysis probably applies not only to the use of incisors by humans, but also to some extent to frugivorous primates. This model should clarify the mechanics behind incision and can provide a basic foundation upon which more advanced models can be built on in the future. PMID:16530808

  8. Postoperative Granulomas at Liposuction Incision Sites.

    PubMed

    Weniger, Frederick G; White, Peter F; Barrero Castedo, Carlos E

    2016-02-01

    Since most liposuction incisions heal uneventfully, difficult healing in such incisions must be investigated. In the cases of two gynecomastia liposuction patients in which a water-based lubricating gel was used on the liposuction incisions, the incisions failed to heal. For both patients, workup uncovered palisading granulomas at the lateral inframammary fold incision sites several months after otherwise successful surgeries. These two cases are presented and the previous literature is reviewed, with consideration given to the etiology and prevention of such granulomas. LEVEL OF EVIDENCE 5: Risk. PMID:26647136

  9. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  10. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  11. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  12. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  13. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  14. Gamma Knife Surgery in Trigeminal Neuralgia.

    PubMed

    Wolf, Amparo; Kondziolka, Douglas

    2016-07-01

    Gamma knife surgery (GKS) represents a safe, effective, and relatively durable noninvasive treatment option for patients with trigeminal neuralgia (TN) and recurrent TN. By one year's time, 75% to 90% of patients will have obtained pain relief, defined as Barrow Neurological Institute grades I to IIIB. Similar rates have been demonstrated for patients undergoing a second GKS for recurrent TN. Predictors of durability of GKS in TN include type I TN, post-GKS Barrow Neurological Institute score, and the presence of post-Gamma Knife facial numbness. PMID:27324996

  15. Climatic control of bedrock river incision.

    PubMed

    Ferrier, Ken L; Huppert, Kimberly L; Perron, J Taylor

    2013-04-11

    Bedrock river incision drives the development of much of Earth's surface topography, and thereby shapes the structure of mountain belts and modulates Earth's habitability through its effects on soil erosion, nutrient fluxes and global climate. Although it has long been expected that river incision rates should depend strongly on precipitation rates, quantifying the effects of precipitation rates on bedrock river incision rates has proved difficult, partly because river incision rates are difficult to measure and partly because non-climatic factors can obscure climatic effects at sites where river incision rates have been measured. Here we present measurements of river incision rates across one of Earth's steepest rainfall gradients, which show that precipitation rates do indeed influence long-term bedrock river incision rates. We apply a widely used empirical law for bedrock river incision to a series of rivers on the Hawaiian island of Kaua'i, where mean annual precipitation ranges from 0.5 metres to 9.5 metres (ref. 12)-over 70 per cent of the global range-and river incision rates averaged over millions of years can be inferred from the depth of river canyons and the age of the volcanic bedrock. Both a time-averaged analysis and numerical modelling of transient river incision reveal that the long-term efficiency of bedrock river incision across Kaua'i is positively correlated with upstream-averaged mean annual precipitation rates. We provide theoretical context for this result by demonstrating that our measurements are consistent with a linear dependence of river incision rates on stream power, the rate of energy expenditure by the flow on the riverbed. These observations provide rare empirical evidence for the long-proposed coupling between climate and river incision, suggesting that previously proposed feedbacks among topography, climate and tectonics may occur. PMID:23579679

  16. Durability of Cutting Performance of a Knife and Micro-Structural Change of a Knife Edge

    NASA Astrophysics Data System (ADS)

    Takekoshi, Kunio; Gotoh, Manabu

    The tested knife material here is mainly SUS420J2 (a kind of stainless steel). This kind of knife is very popular for daily use. From SEM observation of the initial state of the knife-edge tip after the burr removal treatment, we find either some burr and/or a micro-groove, or no burr and no micro-groove along the edge-tip. In order to abrade intentionally, the edge of a knife is repeatedly rubbed perpendicularly to the surface of a Japanese cypress woodblock using the durability-testing machine. During this rubbing process, the abrasion and/or crushing of the edge tip are observed by SEM in detail. The frictional load between the knife-edge and the woodblock is measured. Using the cutting-test machine, the cutting performance of the abraded knives is evaluated by the number of cut pieces of paper. It is discovered that the groove evolves and grows on the edge tip with abrading operation. Moreover, it is concluded that both micro-sidewalls of the groove play a role as cutting edges (i. e., the secondary edge) and this secondary edge and the groove width govern the durability of cutting performance of the knife. Especially the groove width governs it most. These conclusions are also valid for the knives made of other materials such as SUS410 and SUP10.

  17. The “Knife-Cut Sign” Revisited

    PubMed Central

    Cohen, Philip R.

    2015-01-01

    Background: The “knife-cut sign” is a distinctive presentation of linear erosive herpes simplex virus infection in immunocompromised patients. Purpose: To describe a man whose herpes simplex virus infection-related skin lesions demonstrated the “knife-cut sign” and to review the characteristics of reported immunosuppressed individuals with “knife-cut” cutaneous herpes simplex virus lesions. Methods: A man with multiple myeloma and post-stem cell transplant cutaneous graft-versus-host disease managed with systemic prednisone and sirolimus developed disseminated cutaneous herpes simplex virus infection with virus-associated linear ulcers of the inguinal folds and the area between his ear and scalp; the lesions at both sites had a distinctive “knife-cut” appearance. Using the PubMed database, an extensive literature search was performed on herpes simplex virus, immunocompromised patient, and “knife-cut sign”. Results: Herpes simplex virus infection-associated skin lesions that demonstrate the “knife-cut sign” present in patients who are immunosuppressed secondary to either an underlying medical condition or a systemic therapy or both. The distinctive virus-related cutaneous lesions appear as linear ulcers and fissures in intertriginous areas, such as the folds in the inguinal area, the vulva, and the abdomen; in addition, other sites include beneath the breast, within the gluteal cleft, and the area between the ear and the scalp. Not only herpes simplex virus-2, but also herpes simplex virus-1 has been observed as the causative viral serotype; indeed, herpes simplex virus-1 has been associated with genital and inframammary lesions in addition to those above the neck. Direct fluorescent antibody testing is a rapid method for confirming the clinically suspected viral infection; however, since false-negative direct fluorescent antibody testing occurred in some of the patients, it may be prudent to also perform viral cultures and possibly lesional

  18. Experimental Bedrock Channel Incision: Scaling, Sculpture and Sediment Transport

    NASA Astrophysics Data System (ADS)

    Johnson, J. P.; Whipple, K. X.

    2004-12-01

    flux (all else held equal) causes renewed incision, but of an even narrower inner channel; increasing the sediment flux leads to inner channel deposition. Where erosion is most vigorous, sediment generally moving as saltating bedload becomes locally suspended by upward-directed mean flow. For example, swirling clouds of "bedload" particles are continuously suspended by vortices developed within potholes such that the upward flux of particles out of the potholes balance the total sediment flux through the flume. Potholes spontaneously form where average bed slope and fluid velocities were highest, dramatically accelerating the local erosion rate. Our experimental potholes are smaller in scale but morphologically strikingly similar to many observed in the field, and include features such as corkscrew grooves down the outside walls and a protruding horn at the pothole center. More generally, abrasion becomes focused in places where the flow is spatially accelerated, such as in scoops and bends with high curvature. The knife-edge margins and spatial distribution of erosional forms indicate abrupt transitions in erosional efficiency that are tightly coupled to near-bed fluid flow patterns, which in turn are strongly influenced by the erosional forms themselves. Our experiments suggest that, in highly sculpted bedrock channels, naturally developed bed roughness presents a physical length scale that is important to controlling the interaction between sediment impacts and the bed, rather than a length scale based explicitly on sediment transport and average flow conditions such as the saltation hop length.

  19. Hillslope-derived blocks retard river incision

    NASA Astrophysics Data System (ADS)

    Shobe, Charles M.; Tucker, Gregory E.; Anderson, Robert S.

    2016-05-01

    The most common detachment-limited river incision models ignore the effects of sediment on fluvial erosion, yet steep reaches of mountain rivers often host clusters of large (>1 m) blocks. We argue that this distribution of blocks is a manifestation of an autogenic negative feedback in which fast vertical river incision steepens adjacent hillslopes, which deliver blocks to the channel. Blocks inhibit incision by shielding the bed and enhancing form drag. We explore this feedback with a 1-D channel-reach model in which block delivery by hillslopes depends on the river incision rate. Results indicate that incision-dependent block delivery can explain the block distribution in Boulder Creek, Colorado. The proposed negative feedback may significantly slow knickpoint retreat, channel adjustment, and landscape response compared to rates predicted by current theory. The influence of hillslope-derived blocks may complicate efforts to extract base level histories from river profiles.

  20. A method for studying knife tool marks on bone.

    PubMed

    Shaw, Kai-Ping; Chung, Ju-Hui; Chung, Fang-Chun; Tseng, Bo-Yuan; Pan, Chih-Hsin; Yang, Kai-Ting; Yang, Chun-Pang

    2011-07-01

    The characteristics of knife tool marks retained on hard tissues can be used to outline the shape and angle of a knife. The purpose of this study was to describe such marks on bone tissues that had been chopped with knives. A chopping stage with a gravity accelerator and a fixed bone platform was designed to reconstruct the chopping action. A digital microscope was also used to measure the knife angle (θ) and retained V-shape tool mark angle (ψ) in a pig skull. The κ value (elasticity coefficient; θ/ψ) was derived and recorded after the knife angle (θ) and the accompanied velocity were compared with the proportional impulsive force of the knife and ψ on the bone. The constant impulsive force revealed a correlation between the V-shape tool mark angle (ψ) and the elasticity coefficient (κ). These results describe the tool marks--crucial in the medicolegal investigation--of a knife on hard tissues. PMID:21480893

  1. Relaxed Intensity

    ERIC Educational Resources Information Center

    Ramey, Kyle

    2004-01-01

    Relaxed intensity refers to a professional philosophy, demeanor, and way of life. It is the key to being an effective educational leader. To be successful one must be relaxed, which means managing stress efficiently, having fun, and enjoying work. Intensity allows one to get the job done and accomplish certain tasks or goals. Educational leaders…

  2. Gamma Knife Radiosurgery for Choroidal Hemangioma

    SciTech Connect

    Kim, Yun Taek; Kang, Se Woong; Lee, Jung-Il

    2011-12-01

    Purpose: Patients with choroidal hemangioma (CH), a benign ocular hamartoma, frequently presents with visual disturbance as a result of exudative retinal detachment (RD), which originates in subretinal fluid accumulation. We report our experience using the Leksell Gamma Knife in the management of symptomatic CH. Methods and Materials: Seven patients with symptomatic CH (circumscribed form in 3 patients and diffuse form in 4) were treated with the Leksell Gamma Knife at our institution during a 7-year period. All patients presented with exudative RD involving the macula that resulted in severe visual deterioration. The prescription dose to the target margin was 10 Gy in all cases. The mean tumor volume receiving the prescription dose was 536 mm{sup 3} (range, 151-1,057). The clinical data were analyzed in a retrospective fashion after a mean follow-up of 34.4 months (range, 9-76). Results: The resolution of exudative RD was achieved within 6 months, and the visual acuity of the affected eye had improved at the latest follow-up examination (p = .018) in all patients. No recurrence of exudative RD occurred. Thinning of the CHs was observed in most patients; however, symptomatic radiation toxicity had not developed in any of the patients. Conclusion: Symptomatic CHs can be safely and effectively managed with Gamma Knife radiosurgery using a marginal dose of 10 Gy.

  3. Optimal incision sites to reduce corneal aberration variations after small incision phacoemulsification cataract surgery

    PubMed Central

    Chu, Ling; Zhao, Jiang-Yue; Zhang, Jin-Song; Meng, Jie; Wang, Ming-Wu; Yang, Ya-Jing; Yu, Jia-Ming

    2016-01-01

    AIM To analyze the effect of steep meridian small incision phacoemulsification cataract surgery on anterior, posterior and total corneal wavefront aberration. METHODS Steep meridian small incision phacoemulsification cataract surgery was performed in age-related cataract patients which were divided into three groups according to the incision site: 12 o'clock, 9 o'clock and between 9 and 12 o'clock (BENT) incision groups. The preoperative and 3-month postoperative root mean square (RMS) values of anterior, posterior and total corneal wavefront aberration including coma, spherical aberration, and total higher-order aberrations (HOAs), were measured by Pentacam scheimpflug imaging. The mean preoperative and postoperative corneal wavefront aberrations were documented. RESULTS Total corneal aberration and total lower-order aberrations decreased significantly in three groups after operation. RMS value of total HOAs decreased significantly postoperatively in the 12 o'clock incision group (P<0.001). Corneal spherical aberration was statistically significantly lower after steep meridian small incision phacoemulsification cataract surgery in BENT incision group (P<0.05) and Pearson correlation analysis indicated that spherical aberration changes had no significant relationship with total astigmatism changes in all three corneal incision location. CONCLUSION Corneal incision of phacoemulsification cataract surgery can affect corneal wavefront aberration. The 12 o'clock corneal incision eliminated more HOAs and the spherical aberrations decreased in BENT incision group obviously when we selected steep meridian small incision. Cataract lens replacement using wavefront-corrected intraocular lens combined with optimized corneal incision site would improve ocular aberration results. PMID:27162725

  4. Clear Corneal Incision in Cataract Surgery

    PubMed Central

    Al Mahmood, Ammar M.; Al-Swailem, Samar A.; Behrens, Ashley

    2014-01-01

    Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature. PMID:24669142

  5. Clear corneal incision in cataract surgery.

    PubMed

    Al Mahmood, Ammar M; Al-Swailem, Samar A; Behrens, Ashley

    2014-01-01

    Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature. PMID:24669142

  6. Caring for Your Incision After Surgery

    MedlinePlus

    ... if the incision pulls apart. Should I avoid sun exposure? A healing scar will darken and become more noticeable if it gets sunburned. Limit your sun exposure for the first 6 months after surgery. When ...

  7. The oblique mastectomy incision: advantages and outcomes.

    PubMed

    Gronet, Edward M; Halvorson, Eric G

    2014-01-01

    Mastectomy has traditionally been performed using a transverse elliptical incision. The disadvantages of this approach are a potentially visible scar medially and poor subincisional soft-tissue coverage of implants laterally. A more natural and aesthetic result is obtained with an oblique incision running parallel to the pectoralis major muscle fibers. This approach offers women more freedom of choice in clothing as well as the potential for complete subincisional muscle coverage in alloplastic breast reconstruction, in addition to other functional advantages. PMID:24835870

  8. Knife River Indian Villages National Historic Site: Teacher's Guide.

    ERIC Educational Resources Information Center

    National Park Service (Dept. of Interior), Washington, DC. National Register of Historic Places.

    This guide provides history and social studies teachers, at all grade levels, with information and activities about the American Indians of the Northern Plains who lived in the area of the Knife River where it enters the Missouri River. Located in what is now North Dakota, this area is the Knife River Indian Villages National Historic Site. The…

  9. DNA Methylation Modulates Nociceptive Sensitization after Incision

    PubMed Central

    Sun, Yuan; Sahbaie, Peyman; Liang, DeYong; Li, Wenwu; Shi, Xiaoyou; Kingery, Paige; Clark, J. David

    2015-01-01

    DNA methylation is a key epigenetic mechanism controlling DNA accessibility and gene expression. Blockade of DNA methylation can significantly affect pain behaviors implicated in neuropathic and inflammatory pain. However, the role of DNA methylation with regard to postoperative pain has not yet been explored. In this study we sought to investigate the role of DNA methylation in modulating incisional pain and identify possible targets under DNA methylation and contributing to incisional pain. DNA methyltranferase (DNMT) inhibitor 5-Aza-2′-deoxycytidine significantly reduced incision-induced mechanical allodynia and thermal sensitivity. Aza-2′-deoxycytidine also reduced hindpaw swelling after incision, suggesting an anti-inflammatory effect. Global DNA methylation and DNMT3b expression were increased in skin after incision, but none of DNMT1, DNMT3a or DNMT3b was altered in spinal cord or DRG. The expression of proopiomelanocortin Pomc encoding β-endorphin and Oprm1 encoding the mu-opioid receptor were upregulated peripherally after incision; moreover, Oprm1 expression was further increased under DNMT inhibitor treatment. Finally, local peripheral injection of the opioid receptor antagonist naloxone significantly exacerbated incision-induced mechanical hypersensitivity. These results suggest that DNA methylation is functionally relevant to incisional nociceptive sensitization, and that mu-opioid receptor signaling might be one methylation regulated pathway controlling sensitization after incision. PMID:26535894

  10. DNA Methylation Modulates Nociceptive Sensitization after Incision.

    PubMed

    Sun, Yuan; Sahbaie, Peyman; Liang, DeYong; Li, Wenwu; Shi, Xiaoyou; Kingery, Paige; Clark, J David

    2015-01-01

    DNA methylation is a key epigenetic mechanism controlling DNA accessibility and gene expression. Blockade of DNA methylation can significantly affect pain behaviors implicated in neuropathic and inflammatory pain. However, the role of DNA methylation with regard to postoperative pain has not yet been explored. In this study we sought to investigate the role of DNA methylation in modulating incisional pain and identify possible targets under DNA methylation and contributing to incisional pain. DNA methyltranferase (DNMT) inhibitor 5-Aza-2'-deoxycytidine significantly reduced incision-induced mechanical allodynia and thermal sensitivity. Aza-2'-deoxycytidine also reduced hindpaw swelling after incision, suggesting an anti-inflammatory effect. Global DNA methylation and DNMT3b expression were increased in skin after incision, but none of DNMT1, DNMT3a or DNMT3b was altered in spinal cord or DRG. The expression of proopiomelanocortin Pomc encoding β-endorphin and Oprm1 encoding the mu-opioid receptor were upregulated peripherally after incision; moreover, Oprm1 expression was further increased under DNMT inhibitor treatment. Finally, local peripheral injection of the opioid receptor antagonist naloxone significantly exacerbated incision-induced mechanical hypersensitivity. These results suggest that DNA methylation is functionally relevant to incisional nociceptive sensitization, and that mu-opioid receptor signaling might be one methylation regulated pathway controlling sensitization after incision. PMID:26535894

  11. [LASER CONISATION VS. COLD KNIFE CONISATION FOR CIN].

    PubMed

    Karagyozov, I

    2016-01-01

    For the period of 5 years (2008-2012) at the outpatient department and the operation theater of Tokuda hospital 280 conisations were done--135 lasers and 145 cold knifes. Indications for the operation were common, with no specific choice for the aim of comparison. All patients had proven colposcopic or histologic dysplasia of the cervix. The operations were performed 2 or 3 days after menstruation. Laser conisations received local anesthesia and were not hospitalized. Cold knife conisations were done at the operation theater under regional anesthesia, they attended the hospital for 24 hours, had vaginal tapenade and urethral catheter. Indications for the operation were as follows: CIN I-14 laser and 38 cold knife conisations; CIN II-30 laser and 28 cold knife conisations; CIN III--CIS-73 laser and 74 cold knife conisations. The follow up is: 2 months after the operation-colposcopy and every 3 months afterwards--PAP smear and colposcopy for 1 year. PMID:27514128

  12. Natural orifice transluminal endoscopic wedge hepatic resection with a water-jet hybrid knife in a non-survival porcine model

    PubMed Central

    Shi, Hong; Jiang, Sheng-Jun; Li, Bin; Fu, Deng-Ke; Xin, Pei; Wang, Yong-Guang

    2011-01-01

    AIM: To explore the feasibility of a water-jet hybrid knife to facilitate wedge hepatic resection using a natural orifice transluminal endoscopic surgery (NOTES) approach in a non-survival porcine model. METHODS: The Erbe Jet2 water-jet system allows a needleless, tissue-selective hydro-dissection with a pre-selected pressure. Using this system, wedge hepatic resection was performed through three natural routes (trans-anal, trans-vaginal and trans-umbilical) in three female pigs weighing 35 kg under general anesthesia. Entry into the peritoneal cavity was via a 15-mm incision using a hook knife. The targeted liver segment was marked by an APC probe, followed by wedge hepatic resection performed using a water-jet hybrid knife with the aid of a 4-mm transparent distance soft cap mounted onto the tip of the endoscope for holding up the desired plane. The exposed vascular and ductal structures were clipped with Endoclips. Hemostasis was applied to the bleeding cut edges of the liver parenchyma by electrocautery. After the procedure, the incision site was left open, and the animal was euthanized followed by necropsy. RESULTS: Using the Erbe Jet2 water-jet system, trans-anal and trans-vaginal wedge hepatic resection was successfully performed in two pigs without laparoscopic assistance. Trans-umbilical attempt failed due to an unstable operating platform. The incision for peritoneal entry took 1 min, and about 2 h was spent on excision of the liver tissue. The intra-operative blood loss ranged from 100 to 250 mL. Microscopically, the hydro-dissections were relatively precise and gentle, preserving most vessels. CONCLUSION: The Erbe Jet2 water-jet system can safely accomplish non-anatomic wedge hepatic resection in NOTES, which deserves further studies to shorten the dissection time. PMID:21412502

  13. Low-power holmium:YAG laser urethrotomy for urethral stricture disease: comparison of outcomes with the cold-knife technique.

    PubMed

    Atak, Mustafa; Tokgöz, Hüsnü; Akduman, Bülent; Erol, Bülent; Dönmez, Ibrahim; Hancı, Volkan; Türksoy, Ozlem; Mungan, Necmettin Aydın

    2011-11-01

    In this prospective randomized clinical trial, we aimed to evaluate the safety and efficacy of endourethrotomy with holmium:yttrium-aluminium-garnet (HO:YAG) laser and compare the outcomes with the conventional cold-knife urethrotomy. Fifty-one male patients with single, iatrogenic, annular strictures of the urethra were randomly divided into two groups; 21 patients who underwent direct-vision endoscopic urethrotomy with Ho:YAG laser (15 W; 1,200-1,400 mJ; 8-12 Hz) at 12 o'clock position (laser group) and 30 patients who underwent direct-vision endoscopic urethrotomy with cold-knife incision at 12 o'clock position (cold-knife group). The results obtained were analyzed and compared at 3 months, 6 months, 9 months, and 12 months postoperatively by clinical evaluation, uroflowmetry, and retrograde urethrographies. Variables were compared among groups using Fisher's exact and Mann Whitney U tests. There were no differences between two groups in terms of patient age, preoperative Qmax value, stricture location, and length. Operative time was shorter in laser group (16.4 ± 8.04 minutes) when compared with cold-knife group (23.8 ± 5.47 minutes) (p<0.001). Recurrence-free rate at 3 months was similar between two groups (p=0.122). However, recurrence-free rates at 6 months, 9 months, and 12 months were significantly higher in laser group when compared with cold-knife group (p values were 0.045, 0.027, and 0.04, respectively). No intra- or postoperative complications were encountered. Use of Ho:YAG laser in the management of urethral stricture disease is a safe and effective method. In addition, it provides shorter operative time and lower recurrence rate when compared with the conventional technique. PMID:22005159

  14. Relaxation System

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Environ Corporation's relaxation system is built around a body lounge, a kind of super easy chair that incorporates sensory devices. Computer controlled enclosure provides filtered ionized air to create a feeling of invigoration, enhanced by mood changing aromas. Occupant is also surrounded by multidimensional audio and the lighting is programmed to change colors, patterns, and intensity periodically. These and other sensory stimulators are designed to provide an environment in which the learning process is stimulated, because research has proven that while an individual is in a deep state of relaxation, the mind is more receptive to new information.

  15. Comparison of surgically induced astigmatism in various incisions in manual small incision cataract surgery

    PubMed Central

    Jauhari, Nidhi; Chopra, Deepak; Chaurasia, Rajan Kumar; Agarwal, Ashutosh

    2014-01-01

    AIM To determine the surgically induced astigmatism (SIA) in Straight, Frown and Inverted V shape (Chevron) incisions in manual small incision cataract surgery (SICS). METHODS A prospective cross sectional study was done on a total of 75 patients aged 40y and above with senile cataract. The patients were randomly divided into three groups (25 each). Each group received a particular type of incision (Straight, Frown or Inverted V shape incisions). Manual SICS with intraocular lens (IOL) implantation was performed. The patients were compared 4wk post operatively for uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) and SIA. All calculations were performed using the SIA calculator version 2.1, a free software program. The study was analyzed using SPSS version 15.0 statistical analysis software. RESULTS The study found that 89.5% of patients in Straight incision group, 94.2% in Frown incision group and 95.7% in Inverted V group attained BCVA post-operatively in the range of 6/6 to 6/18. Mean SIA was minimum (-0.88±0.61D×90 degrees) with Inverted V incision which was statistically significant. CONCLUSION Inverted V (Chevron) incision gives minimal SIA. PMID:25540754

  16. Transconjunctival incision for total maxillectomy--an alternative for subciliary incision.

    PubMed

    Goyal, Amit; Tyagi, Isha; Jain, Shilpa; Syal, Rajan; Singh, Alok Pratap; Kapila, Rajeev

    2011-09-01

    A subciliary incision may be associated with various complications of the lower eyelid when it is used during a total maxillectomy. The use of the transconjunctival incision instead is an alternative in suitable patients. The records of 17 patients were reviewed in whom a transconjunctival incision was used during total maxillectomy. These included 13 in whom the Weber-Ferguson incision was used, and 4 who had a sublabial incision. There was mild conjunctival oedema in all the cases during the immediate postoperative period but it did not last for more than two days. Four patients had mild to moderate oedema of the lid that resolved within two days. One had mild ectropion with transient epiphora, which was caused by early removal of the medial canthal sutures. We found the approach to be cosmetically acceptable as it avoids a scar in the subciliary region. The transconjunctival incision can be used in place of the subciliary incision for lateral exposure during total maxillectomy. There are few complications associated with the lower lid, and it has good cosmetic results; if it is combined with a sublabial incision in suitable patients, the maxillectomy is virtually scar-free. PMID:20673694

  17. Knife and impact cutting of lamb bone.

    PubMed

    King, M J

    1999-05-01

    The forces and hence fracture energies required to cut bone are presented in this paper and the merits of cutting with a high speed blade are considered. A plain knife blade was used to cut cancellous and compact lamb bone using three different methods. A microtome was used to produce a range of cut thicknesses which enabled the fracture energy to be separated into friction, surface fracture and plastic deformation energies. A tensile test machine was used to produce thicker off-cuts so that the energy required to cut through full sections of bone could be determined. A high speed rail gun was used to cut at speeds up to 130 m/s. The energy required to cut bone did not change with blade speed. However, the energies measured during the cutting varied over a wide range. In situations in which the surface of the cut bone exhibited a very uneven surface high energy was required, whereas when the resulting cut surface was planar the cutting energy was low. A light weight blade which impacts the bone at high speed will transmit a small impulse to the carcass which may be absorbed without transmitting strain to the muscle/connective tissue. This may allow the development of a high speed knife which will cut bone without excessively damaging the meat surrounding the cut. PMID:22062140

  18. Peripheral dose in ocular treatments with CyberKnife and Gamma Knife radiosurgery compared to proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Zytkovicz, A.; Daftari, I.; Phillips, T. L.; Chuang, C. F.; Verhey, L.; Petti, P. L.

    2007-09-01

    Peripheral radiation can have deleterious effects on normal tissues throughout the body, including secondary cancer induction and cataractogenesis. The aim of this study is to evaluate the peripheral dose received by various regions of the body after ocular treatment delivered with the Model C Gamma Knife, proton radiotherapy with a dedicated ocular beam employing no passive-scattering system, or a CyberKnife unit before and after supplemental shielding was introduced. TLDs were used for stray gamma and x-ray dosimetry, whereas CR-39 dosimeters were used to measure neutron contamination in the proton experiments. Doses to the contralateral eye, neck, thorax and abdomen were measured on our anthropomorphic phantom for a 56 Gy treatment to a 588 mm3 posterior ocular lesion. Gamma Knife (without collimator blocking) delivered the highest dose in the contralateral eye, with 402-2380 mSv, as compared with 118-234 mSv for CyberKnife pre-shielding, 46-255 mSv for CyberKnife post-shielding and 9-12 mSv for proton radiotherapy. Gamma Knife and post-shielding CyberKnife delivered comparable doses proximal to the treatment site, with 190 versus 196 mSv at the thyroid, whereas protons doses at these locations were less than 10 mSv. Gamma Knife doses decreased dramatically with distance from the treatment site, delivering only 13 mSv at the lower pelvis, comparable to the proton result of 4 to 7 mSv in this region. In contrast, CyberKnife delivered between 117 and 132 mSv to the lower pelvis. In conclusion, for ocular melanoma treatments, a proton beam employing no double scattering system delivers the lowest peripheral doses proximally to the contralateral eye and thyroid when compared to radiosurgery with the Model C Gamma Knife or CyberKnife. At distal locations in the pelvis, peripheral doses delivered with proton and Gamma Knife are of an order of magnitude smaller than those delivered with CyberKnife.

  19. Peripheral dose in ocular treatments with CyberKnife and Gamma Knife radiosurgery compared to proton radiotherapy.

    PubMed

    Zytkovicz, A; Daftari, I; Phillips, T L; Chuang, C F; Verhey, L; Petti, P L

    2007-10-01

    Peripheral radiation can have deleterious effects on normal tissues throughout the body, including secondary cancer induction and cataractogenesis. The aim of this study is to evaluate the peripheral dose received by various regions of the body after ocular treatment delivered with the Model C Gamma Knife, proton radiotherapy with a dedicated ocular beam employing no passive-scattering system, or a CyberKnife unit before and after supplemental shielding was introduced. TLDs were used for stray gamma and x-ray dosimetry, whereas CR-39 dosimeters were used to measure neutron contamination in the proton experiments. Doses to the contralateral eye, neck, thorax and abdomen were measured on our anthropomorphic phantom for a 56 Gy treatment to a 588 mm(3) posterior ocular lesion. Gamma Knife (without collimator blocking) delivered the highest dose in the contralateral eye, with 402-2380 mSv, as compared with 118-234 mSv for CyberKnife pre-shielding, 46-255 mSv for CyberKnife post-shielding and 9-12 mSv for proton radiotherapy. Gamma Knife and post-shielding CyberKnife delivered comparable doses proximal to the treatment site, with 190 versus 196 mSv at the thyroid, whereas protons doses at these locations were less than 10 mSv. Gamma Knife doses decreased dramatically with distance from the treatment site, delivering only 13 mSv at the lower pelvis, comparable to the proton result of 4 to 7 mSv in this region. In contrast, CyberKnife delivered between 117 and 132 mSv to the lower pelvis. In conclusion, for ocular melanoma treatments, a proton beam employing no double scattering system delivers the lowest peripheral doses proximally to the contralateral eye and thyroid when compared to radiosurgery with the Model C Gamma Knife or CyberKnife. At distal locations in the pelvis, peripheral doses delivered with proton and Gamma Knife are of an order of magnitude smaller than those delivered with CyberKnife. PMID:17881812

  20. OCT-Documented Incision Features and Natural History of Clear Corneal Incisions Used for Bimanual Microincision Cataract Surgery

    PubMed Central

    Lyles, Graham W.; Cohen, Kenneth L.; Lam, Diana

    2013-01-01

    Purpose Use of anterior segment OCT to identify features and natural history of bimanual incisions used only for phacoemulsification and a main incision used only for intraocular lens insertion. Methods Prospective study of 25 subjects who had uncomplicated bimanual phacoemulsification. The Zeiss Visante OCT identified incisions at 1 day, 1 week, and 1 month postoperatively. The absence or presence of features, endothelial gaping, detachment of the Descemet membrane, endothelial misalignment, epithelial gaping, and/or loss of coaptation, was recorded. Main incision data were compared with bimanual incision data. The difference for each feature, between the main incision and the bimanual incision, at each time point and over time were calculated. Results The most common findings at 1 day, 1 week, and 1 month were main incision endothelial misalignment (52%) and bimanual incision endothelial gape (24%), main incision endothelial misalignment (60%) and bimanual incision endothelial gape (22%), and main incision endothelial misalignment (35%) and bimanual incision endothelial misalignment (14%), respectively. Only at 1 day and 1 week was endothelial misalignment significantly more common in the main incision (P = 0.0352 and 0.0005, respectively). The only other incision feature that differed significantly was endothelial gape, which was more frequent in the bimanual incision at 1 week (P = 0.0391). For each incision feature combined over all time periods, only endothelial misalignment was significantly more prevalent in the main incision (P = 0.0004), whereas endothelial gape was more common in the bimanual incision (P = 0.0352). Conclusions Using OCT, bimanual phacoemulsification did not adversely affect the anatomic incision integrity and healing. PMID:21242779

  1. Feasibility and acute healing of vocal fold microflap incisions in a rabbit model

    PubMed Central

    Suehiro, Atsushi; Bock, Jonathan M.; Hall, Joseph E.; Garrett, C. Gaelyn; Rousseau, Bernard

    2012-01-01

    Objectives The purpose of this study was to: 1) investigate the feasibility of performing mucosal elevation of a vocal fold microflap in a rabbit model, and 2) measure the acute healing of rabbit microflap incisions compared to control vocal folds. Study Design Prospective animal study Methods Ten New Zealand white rabbits were used in this study. All rabbits received a 3mm incision through the epithelium of one vocal fold using a sickle knife and mucosal elevation through this incision using a microlaryngeal fine angled spatula. The contralateral vocal fold was left intact to serve as an internal control. Student t tests were used to investigate differences in epithelial thickness, immunohistochemical staining of CD 45, and inflammatory and pro-fibrotic gene expression between vocal folds undergoing microflap and control. Results Exposure of the rabbit larynx was achieved, allowing for the identification of a surgical plane and the creation of a microflap and elevation of the vocal fold mucosa. Hematoxylin-eosin staining revealed no significant differences in epithelial thickness, immunohistochemistry for CD 45 showed no significant differences in CD 45 positive cells, and quantitative PCR revealed no significant differences in IL-1β, TGFβ-1, or COX-2 gene expression between vocal folds undergoing microflap and control. Conclusions We demonstrate the feasibility of vocal fold microflap surgery in a rabbit model. With the advantage of greater access to primers and antibodies for molecular biological studies, the application of the microflap technique in a small animal model such as rabbit has broad implications for future experimental investigations in laryngology. Level of Evidence Animal Research. PMID:22253007

  2. Minimally Invasive Cardiovascular Surgery: Incisions and Approaches

    PubMed Central

    Langer, Nathaniel B.; Argenziano, Michael

    2016-01-01

    Throughout the modern era of cardiac surgery, most operations have been performed via median sternotomy with cardiopulmonary bypass. This paradigm is changing, however, as cardiovascular surgery is increasingly adopting minimally invasive techniques. Advances in patient evaluation, instrumentation, and operative technique have allowed surgeons to perform a wide variety of complex operations through smaller incisions and, in some cases, without cardiopulmonary bypass. With patients desiring less invasive operations and the literature supporting decreased blood loss, shorter hospital length of stay, improved postoperative pain, and better cosmesis, minimally invasive cardiac surgery should be widely practiced. Here, we review the incisions and approaches currently used in minimally invasive cardiovascular surgery. PMID:27127555

  3. Surface characterization of micro-optical components by Foucault's knife-edge method: the case of a micromirror array.

    PubMed

    Zamkotsian, F; Dohlen, K

    1999-11-01

    As micro-optical components are introduced into optical systems, accurate surface characterization becomes important. We describe a method for quantitative evaluation of surface deformations based on Foucault's knife-edge test. By measurement of local slopes, the surface shape of each mirror in a micromirror array has been reconstructed with a subnanometer accuracy. In addition to low-order deformation (tilt, curvature, astigmatism), each mirror is seen to be palm-tree shaped. This may be explained by strain relaxation in the fabrication process. Measurement on a conventional concave mirror confirms our method. PMID:18324186

  4. Gamma knife radiosurgery for pituitary adenomas.

    PubMed

    Ježková, Jana; Marek, Josef

    2016-09-01

    Pituitary adenomas are frequently occurring intracranial neoplasms. The aim of the treatment of pituitary adenomas is to normalize hormonal hypersecretion, to preserve the normal pituitary function, to reserve or treat impaired pituitary function and to control tumor growth and its mechanical effects on the surrounding structures. Treatment modalities include surgical, medical and radiation therapy. Radiosurgery is mainly used as a secondary line treatment after surgery for residual or recurrent tumors. The antiproliferative effect is achieved by LKG irradiation in more than 90% of patients. Regarding the functioning pituitary adenomas, the manifestation of the treatment effect is slow and depends mainly on the type of adenoma. Gamma knife irradiation is safe when the maximal doses to pituitary and infundibulum are respected. PMID:26899535

  5. The transareolar incision for breast augmentation revisited.

    PubMed

    Kompatscher, Peter; Schuler, Christine; Beer, Gertrude M

    2004-01-01

    Of the various possible incisions for breast augmentation, the transareolar access has gained only limited popularity. The potential side effects of this incision are said to be altered nipple sensation, impaired lactation, an increased rate of infections with capsular fibrosis, well visible scar formation with hypopigmentation, and the need for an additional access in case a breast ptosis correction should prove necessary at a later date. The purpose of this retrospective study was to judge advantages and limitations of transareolar breast augmentation, and to verify whether the reluctant attitude toward this surgical approach is justified. A sample of 18 patients with a transareolar, retropectoral breast augmentation was selected for a retrospective evaluation. The suitability of the technique in general was examined together with early postoperative complications, sensory changes, and late complications on the basis of an evaluation system for cosmetic surgical results. The study showed that only women with an areolar diameter of 3.5 cm or more without pronounced breast ptosis were suitable for the transareolar access. No early infections were noted. The rate of capsular fibrosis was 11%. Two years after breast augmentation, 16 women (89%) judged their breast sensation to be normal, but objective assessment showed that mean pressure and vibration sensation were moderately compromised in all parts of the breast. The scars were of good quality, with very little hypopigmentation. With appropriate patient selection, respecting the advantages and limitations, the transareolar incision has its definite place among the different incisions for breast augmentation. PMID:15164231

  6. Small incision lenticule extraction (SMILE) in 2015.

    PubMed

    Chan, Colin; Lawless, Michael; Sutton, Gerard; Versace, Patrick; Hodge, Chris

    2016-05-01

    Small incision lenticule extraction (SMILE) represents a recent addition to the refractive surgeon's range of procedures. Although there remains a number of similarities to existing techniques in terms of patient selection and treatment parameters, consideration is required to optimise patient outcomes and satisfaction. Here, we review the selection criteria, contraindications, indications and existing published safety and efficacy outcomes. PMID:27156103

  7. Trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife: A pilot animal study

    PubMed Central

    Jiang, Sheng-Jun; Shi, Hong; Swar, Gyanendra; Wang, Hai-Xia; Liu, Xiao-Jing; Wang, Yong-Guang

    2013-01-01

    AIM: To investigate the feasibility and safety of Natural orifice trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife in a non-survival porcine model. METHODS: Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy was performed on three non-survival pigs, by transumbilical approach, using a water-jet hybrid-knife. Under general anesthesia, the following steps detailed the procedure: (1) incision of the umbilicus followed by the passage of a double-channel flexible endsocope through an overtube into the peritoneal cavity; (2) establishment of pneumoperitoneum; (3) abdominal exploration; (4) endoscopic cholecystectomy: dissection of the gallbladder performed using water jet equipment, ligation of the cystic artery and duct conducted using nylon loops; and (5) necropsy with macroscopic evaluation. RESULTS: Transumbilical endoscopic cholecystectomy was successfully completed in the first and third pig, with minor bleedings. The dissection times were 137 and 42 min, respectively. The total operation times were 167 and 69 min, respectively. And the lengths of resected specimen were 6.5 and 6.1 cm, respectively. Instillation of the fluid into the gallbladder bed produced edematous, distended tissue making separation safe and easy. Reliable ligation using double nylon loops insured the safety of cutting between the loops. There were no intraoperative complications or hemodynamic instability. Uncontrolled introperative bleeding occurred in the second case, leading to the operation failure. CONCLUSION: Pure NOTES trans-umbilical cholecystectomy with a water-jet hybrid-knife appears to be feasible and safe. Further investigation of this technique with long-term follow-up in animals is needed to confirm the preliminary observation. PMID:24187461

  8. Treatment of epidermoid tumors with gamma knife radiosurgery: Case series

    PubMed Central

    Vasquez, Javier A. Jacobo; Fonnegra, Julio R.; Diez, Juan C.; Fonnegra, Andres

    2016-01-01

    Background: Epidermoid tumors (ETs) are benign lesions that are treated mainly by means of surgical resection, with overall good results. External beam radiotherapy is an alternative treatment for those recurrent tumors, in which a second surgery might not be the best choice for the patient. A little information exists about the effectiveness of gamma knife radiosurgery for the treatment of newly diagnosed and recurrent ETs. We present three cases of ETs treated with gamma knife radiosurgery. Case Description: Case 1 is a 21-year-old female with an ET located in the left cerebellopontine angle (CPA) with symptoms related to VIII cranial nerve dysfunction. Symptom control was achieved and maintained after single session radiosurgery with gamma knife. Case 2 is a 59-year-old female patient with the history of trigeminal neuralgia secondary to a recurrent ET located in the left CPA. Significant pain improvement was achieved after treatment with gamma knife radiosurgery. Case 3 is a 29-year-old male patient with a CPA ET causing long lasting trigeminal neuralgia, pain relief was achieved in this patient after gamma knife radiosurgery. Conclusion: Long-term symptom relief was achieved in all three cases proving that gamma knife radiosurgery is a good and safe alternative for patients with recurrent or nonsurgically treated ETs. PMID:26958427

  9. Drainage basins and channel incision on Mars.

    PubMed

    Aharonson, Oded; Zuber, Maria T; Rothman, Daniel H; Schorghofer, Norbert; Whipple, Kelin X

    2002-02-19

    Measurements acquired by the Mars Orbiter Laser Altimeter on board the Mars Global Surveyor indicate that large drainage systems on Mars have geomorphic characteristics inconsistent with prolonged erosion by surface runoff. We find the topography has not evolved to an expected equilibrium terrain form, even in areas where runoff incision has been previously interpreted. By analogy with terrestrial examples, groundwater sapping may have played an important role in the incision. Longitudinally flat floor segments may provide a direct indication of lithologic layers in the bedrock, altering subsurface hydrology. However, it is unlikely that floor levels are entirely due to inherited structures due to their planar cross-cutting relations. These conclusions are based on previously unavailable observations, including extensive piece-wise linear longitudinal profiles, frequent knickpoints, hanging valleys, and small basin concavity exponents. PMID:16578863

  10. Drainage basins and channel incision on Mars

    PubMed Central

    Aharonson, Oded; Zuber, Maria T.; Rothman, Daniel H.; Schorghofer, Norbert; Whipple, Kelin X.

    2002-01-01

    Measurements acquired by the Mars Orbiter Laser Altimeter on board the Mars Global Surveyor indicate that large drainage systems on Mars have geomorphic characteristics inconsistent with prolonged erosion by surface runoff. We find the topography has not evolved to an expected equilibrium terrain form, even in areas where runoff incision has been previously interpreted. By analogy with terrestrial examples, groundwater sapping may have played an important role in the incision. Longitudinally flat floor segments may provide a direct indication of lithologic layers in the bedrock, altering subsurface hydrology. However, it is unlikely that floor levels are entirely due to inherited structures due to their planar cross-cutting relations. These conclusions are based on previously unavailable observations, including extensive piece-wise linear longitudinal profiles, frequent knickpoints, hanging valleys, and small basin concavity exponents. PMID:16578863

  11. Gamma knife radiosurgery in 11 hemangioblastomas.

    PubMed

    Niemelä, M; Lim, Y J; Söderman, M; Jääskeläinen, J; Lindquist, C

    1996-10-01

    One suprasellar, one mesencephalic, and nine cerebellar hemangioblastomas were treated with the gamma knife in 10 patients (median age 48 years) in Stockholm between 1978 and 1993. Four patients had von Hippel-Lindau disease, a dominant inherited trait predisposing to multiple hemangioblastomas. Six hemangioblastomas were treated with radiotherapy at a median margin dose of 25 Gy (20-35 Gy) before 1990 and the next five with a median of 10 Gy (5-19 Gy). Computerized tomography or magnetic resonance images were available for 10 of the 11 hemangioblastomas at a median follow-up time of 26 months (4-68 months) after radiosurgery. The solid part of six hemangioblastomas shrank in a median of 30 months, whereas four hemangioblastomas were unchanged at a median of 14 months. Five hemangioblastomas had an adjoining cyst and three of these cysts had to be evacuated after radiosurgery. One solitary hemangioblastoma later developed a de novo cyst that also needed evacuation. One patient with two cerebellar hemangioblastomas (margin dose 25 Gy each) developed edema at 6 months and required a shunt and prolonged corticosteroid treatment. The combined follow-up data of the 23 hemangioblastomas in 15 patients from previous literature and the present series indicate that, first, a solitary small- or medium-sized hemangioblastoma usually shrinks or stops growing after radiosurgery. The recommended margin dose is 10 to 15 Gy. Second, the adjoining cyst often does not respond to radiosurgery but requires later, sometimes repeated evacuation. PMID:8814161

  12. Gamma Knife radiosurgery for intracranial hemangioblastoma.

    PubMed

    Silva, Danilo; Grabowski, Mathew M; Juthani, Rupa; Sharma, Mayur; Angelov, Lilyana; Vogelbaum, Michael A; Chao, Samuel; Suh, John; Mohammadi, Alireza; Barnett, Gene H

    2016-09-01

    Gamma knife radiosurgery (GKRS) has become a treatment option for intracranial hemangioblastomas, especially in patients with poor clinical status and also high-risk surgical candidates. The objective of this study was to analyze clinical outcome and tumor control rates. Retrospective chart review revealed 12 patients with a total of 20 intracranial hemangioblastomas treated with GKRS from May 1998 until December 2014. Kaplan-Meier plots were used to calculate the actuarial local tumor control rates and rate of recurrence following GKRS. Univariate analysis, including log rank test and Wilcoxon test were used on the Kaplan-Meier plots to evaluate the predictors of tumor progression. Two-tailed p value of <0.05 was considered as significant. Median follow-up was 64months (2-184). Median tumor volume pre-GKRS was 946mm(3) (79-15970), while median tumor volume post-GKRS was 356mm(3) (30-5404). Complications were seen in two patients. Tumor control rates were 100% at 1year, 90% at 3years, and 85% at 5years, using the Kaplan-Meier method. There were no statistically significant univariate predictors of progression identified, although there was a trend towards successful tumor control in solid tumors (p=0.07). GKRS is an effective and safe option for treating intracranial hemangioblastoma with favorable tumor control rates. PMID:27422585

  13. Minimizing the Submandibular Incision in Endoscopic Subcondylar Fracture Repair.

    PubMed

    Aboelatta, Yasser Abdallah; Elbarbary, Amir S; Abdelazeem, Sarah; Massoud, Karim S; Safe, Ikram I

    2015-12-01

    Endoscope-assisted treatment of mandibular condylar fractures is an evolving surgical technique of this controversial subject. The approach is performed through an intraoral and additional submandibular incision. This study presents a technique for minimizing the length of the optional submandibular incision. Ten patients with displaced subcondylar fractures and malocclusion underwent endoscope-assisted open reduction and internal fixation (ORIF). A limited (<1 cm) submandibular incision (dissected under endoscopic guidance from within) was needed in eight patients to complement the intraoral incision and facilitate the reduction in the fractures. Satisfactory small scar could be obtained in all patients with neither wound complications nor facial nerve injuries. Our technique depends on dissection first then incision. Performing the external incision after complete intraoral dissection is safe for the facial nerve and minimizes scarring markedly. This very limited submandibular incision facilitates reduction in relatively difficult cases and enables clear visualization of posterior border of the mandible to confirm adequate fracture reduction. PMID:26576236

  14. The use of a surgical incision management system on vascular surgery incisions: a pilot study.

    PubMed

    Weir, Gregory

    2014-06-01

    Health care-associated infections in hospitals, including surgical site infections, contribute significantly to morbidity as well as mortality. Surgical incision management (SIM) using negative pressure wound therapy (Prevena™ Incision Management System, Kinetic Concepts, Inc., San Antonio, TX, USA) is designed to cover and protect closed surgical incisions from external factors including infectious sources and local trauma, while negative pressure removes fluid and infectious material from the surgical incision. A prospective case-control study assessed wound complications in patients undergoing vascular bypass procedures, where both femoral areas were incised to gain access to the femoral arteries. SIM was placed on one femoral area while a standard postoperative wound dressing was placed on the contralateral femoral area. Eight patients were included in this pilot study. All of them required bilateral femoral artery access. During the follow-up period patients were monitored for wound complications. All wound complications requiring surgical intervention were considered significant. No significant wound complications occurred in wounds treated with SIM, compared with three significant complications in control wounds. These preliminary data would suggest a potential reduction in wound complications and no observed increase in haemorrhage in high-risk patients with severe co-morbidities undergoing vascular surgery. PMID:24851730

  15. Development of an air knife to remove seed coat fragments during lint cleaning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An air knife is a tool commonly used to blow off debris in a manufacturing line. The knife may also be used to break the attachment force between a lint cleaner saw and a seed coat fragment (SCF) with attached fiber, and remove them. Work continued on evaluating an auxiliary air knife mounted on t...

  16. Anomalous primary radiation from the Leksell Gamma Knife Unit.

    PubMed

    Shearer, D R; Roventine, W A; Coy, S R

    1994-12-01

    The Leksell Gamma Knife Unit, Type U, utilizes 201 separate 60Co sources intersecting at a common focus for radiosurgical treatment of the brain. It has been generally understood that all primary unattenuated radiation beams are confined within the protective housing during all phases of Gamma Knife operation. We have found that when the unit's shielding door is lowered for treatment, twelve primary beams exit the unit's door opening. Furthermore, in the original Gamma Knife unit design, two of the twelve primary beams failed to be attenuated by either the unit base or the unit wings. This has implications for the design of structural shielding and the protection of personnel during emergency procedures. Engineering modifications to eliminate the problem are discussed. PMID:7960787

  17. Minimum-incision metatarsal ray resection: an observational case series.

    PubMed

    Roukis, Thomas S

    2010-01-01

    This report describes the results of 17 metatarsal ray resections performed through a minimal incision in 13 consecutive patients. Each patient underwent minimum-incision metatarsal ray resection for either definitive treatment or as the index incision and drainage procedure followed by transmetatarsal amputation. There were 10 male and 3 female patients with a mean age of 68.8 +/- 8.5 years (range, 59-83 years). Twelve patients had diabetes mellitus and 7 had critical limb ischemia. There were 11 right feet and 6 left feet involved, and 3 second, 3 third, 3 fourth, and 8 fifth minimum-incision metatarsal ray resections performed. Direct primary-incision closure was performed 7 times (1 with adjacent percutaneous metatarsal osteotomy), delayed primary closure was performed 4 times (1 with external fixation), and conversion to a transmetatarsal amputation was performed 2 times. Fourteen of 17 minimum-incision metatarsal ray resections were deemed successful. Two failures occurred when skin necrosis developed from excessive tension along the incision line requiring conversion to a transmetatarsal amputation, and the other occurred in a patient with unreconstructed critical limb ischemia who underwent multiple repeated incision and drainage procedures and vascular bypass with ultimate healing via secondary intent. When properly performed in patients with adequate vascular inflow, minimum-incision metatarsal ray resection as the definitive procedure or in conjunction with an incision and drainage for unsalvageable toe infection or gangrene represents a safe, simple, useful technique. PMID:20123288

  18. Breathing and Relaxation

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  19. Repeat Gamma Knife surgery for vestibular schwannomas

    PubMed Central

    Lonneville, Sarah; Delbrouck, Carine; Renier, Cécile; Devriendt, Daniel; Massager, Nicolas

    2015-01-01

    Background: Gamma Knife (GK) surgery is a recognized treatment option for the management of small to medium-sized vestibular schwannoma (VS) associated with high-tumor control and low morbidity. When a radiosurgical treatment fails to stop tumor growth, repeat GK surgery can be proposed in selected cases. Methods: A series of 27 GK retreatments was performed in 25 patients with VS; 2 patients underwent three procedures. The median time interval between GK treatments was 45 months. The median margin dose used for the first, second, and third GK treatments was 12 Gy, 12 Gy, and 14 Gy, respectively. Six patients (4 patients for the second irradiation and 2 patients for the third irradiation) with partial tumor regrowth were treated only on the growing part of the tumor using a median margin dose of 13 Gy. The median tumor volume was 0.9, 2.3, and 0.7 cc for the first, second, and third treatments, respectively. Stereotactic positron emission tomography (PET) guidance was used for dose planning in 6 cases. Results: Mean follow-up duration was 46 months (range 24–110). At the last follow-up, 85% of schwannomas were controlled. The tumor volume decreased, remained unchanged, or increased after retreatment in 15, 8, and 4 cases, respectively. Four patients had PET during follow-up, and all showed a significant metabolic decrease of the tumor. Hearing was not preserved after retreatment in any patients. New facial or trigeminal palsy did not occur after retreatment. Conclusions: Our results support the long-term efficacy and low morbidity of repeat GK treatment for selected patients with tumor growth after initial treatment. PMID:26500799

  20. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    SciTech Connect

    Aubuchon, Adam C.; Chan, Michael D.; Lovato, James F.; Balamucki, Christopher J.; Ellis, Thomas L.; Tatter, Stephen B.; McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G.

    2011-11-15

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  1. Relaxation Assessment with Varied Structured Milieu (RELAX).

    ERIC Educational Resources Information Center

    Cassel, Russell N.; Cassel, Susie L.

    1983-01-01

    Describes Relaxation Assessment with Varied Structured Milieu (RELAX), a clinical program designed to assess the degree to which an individual is able to demonstrate self-control for overall general relaxation. The program is designed for use with the Cassel Biosensors biofeedback equipment. (JAC)

  2. Effect of surface roughness on contact pressure of static seals (Sealing characteristics of knife-edge seals)

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Yoshio; Hosokawa, Kazuo; Funabashi, Koichi

    1992-09-01

    The sealing mechanism of knife-edge seals was investigated experimentally by varying the width of the flat area on the apex of the knife edge. The most suitable shape of the knife edge with the lowest compressive force for sealing was determined, and a new type of knife edge was developed.

  3. Minimal inframammary incision for breast augmentation

    PubMed Central

    Fanous, Nabil; Tawilé, Caroline; Brousseau, Valérie J

    2008-01-01

    The inframammary approach in breast augmentation, still the most popular technique among plastic surgeons, has always been hampered by the undesirable appearance of its scar. The present paper describes a modified approach to inframammary augmentation with saline-filled prostheses. This approach uses a very short incision, thus resulting in a much less noticeable scar. The surgical technique is easy to learn, simple to execute, does not necessitate any special equipment and gives consistent results. Decreasing the scar length to an absolute minimum ensures higher patient and surgeon satisfaction. PMID:19554159

  4. PROSPECTIVE COMPARATIVE STUDY BETWEEN PROXIMAL TRANSVERSE INCISION AND THE CONVENTIONAL LONGITUDINAL INCISIONS FOR CARPAL TUNNEL RELEASE

    PubMed Central

    Teixeira Alves, Marcelo de Pinho

    2015-01-01

    Carpal tunnel syndrome (CTS) is a pathological condition frequently seen in orthopedic consultation offices. It is most common compressive neuropathy and also the one most often treated surgically. CTS is usually diagnosed clinically, through the clinical history, physical examination (Tinel, Phalen and Durkan tests) and complementary examinations, and more specifically, nerve conduction studies. Ultrasound scans and magnetic resonance imaging may also be used. Conservative treatment is reserved for patients presenting with mild symptoms, with little incapacitation, who show good response to non-steroidal or steroidal anti-inflammatory drugs, physiotherapy and lifestyle changes. Surgical treatment is more frequent, and a variety of techniques are used. The goal of the surgery is to decompress the carpal tunnel and, by sectioning the transverse carpal ligament, release the median nerve. The aim of this paper was to compare surgical treatment of CTS by means of a transverse mini-incision made proximally to the carpal canal, with the classic longitudinal incision over the carpal canal. The mini-incision technique was shown to be less invasive and equally effective for treating CTS, with less morbidity than with the classic longitudinal incision. PMID:27022592

  5. Optical Coherence Tomography of Clear Corneal Incisions for Cataract Surgery

    PubMed Central

    Schallhorn, Julie M.; Tang, Maolong; Li, Yan; Song, Jonathan C.; Huang, David

    2008-01-01

    Purpose To study the architecture of clear corneal incisions for phacoemulsification cataract surgery using optical coherence tomography (OCT). Setting University-based cornea practice. Methods A prospective study of twenty eyes of twenty patients one month after cataract surgery performed by two experienced surgeons. Temporal clear corneal single-plane incisions were made with 3-mm metal keratomes; five of the twenty eyes received sutures for wound closure. Each eye was scanned before and 1 month after surgery with a prototype high-speed anterior segment OCT system (Carl Zeiss Meditec Inc.). The OCT scans were repeated 3 times during the same visit. The length of the corneal incision, thickness of the cornea, and position of the incision (distance from the external wound edge to the scleral spur) were measured using a computer caliper. The angle of the incision relative to the corneal surface was then calculated. Results The mean corneal incision length was 1.81±0.27mm, the mean corneal thickness at the incision was 747±67µm, and the mean distance between the incision and the scleral spur was 1.46±0.24mm. The average angle of the incision was 26.8±5.5°. The measurements were repeatable to within 0.072mm (pooled standard deviation) for the incision length, 11µm for the corneal thickness, and 0.042mm for the position of the incision. There was no statistically significant difference in any of the parameters between eyes with sutures and those without. Conclusions OCT provides an excellent way to evaluate corneal incisions in cataract surgery postoperatively. Measurements of wound dimensions using OCT are highly repeatable. PMID:18721720

  6. Manual Small Incision Cataract Surgery: A Review.

    PubMed

    Venkatesh, Rengaraj; Chang, David F; Muralikrishnan, Radhakrishnan; Hemal, Kenia; Gogate, Pariskshit; Sengupta, Sabyasachi

    2012-01-01

    We aim at reviewing published peer-reviewed studies that evaluate the safety and efficacy of manual small incision cataract surgery (MSICS). Literature searches of the PubMed and the Cochrane Library databases were conducted with no date restrictions; the searches were limited to articles published in English only. All publications with at least level II and III evidence were studied and surgical techniques were analyzed. MSICS was also compared with phacoemulsification and large incision extracapsular cataract surgery (ECCE) with respect to visual outcome, surgery time, cost, intra and postoperative complications and suitability for high volume surgical practices in the developing world.The overall safety profile of MSICS was found to be excellent with intra and postoperative complication rates comparable to phacoemulsification and ECCE. Multiple studies reported the safety and efficacy of MSICS for complicated cases, such as brunescent and white cataract and cataracts associated with phacolytic and phacomorphic glaucoma. Compared to phacoemulsification MSICS was associated with lower and shorter operative times. Visual outcomes were excellent and comparable to phacoemulsification with up to 6 months follow up.The literature provides outcome analysis of a variety of different MSICS techniques. As a whole, MSICS provides excellent outcomes with a low rate of surgical and postoperative complications. Particularly in the developing world, MSICS appears to provide outcomes that are of comparable quality to phacoemulsification at a much lower cost. PMID:26107133

  7. 40. Main fuses and knife switch for power to the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Main fuses and knife switch for power to the bridge, located in the control house. This is one of two located at either end of the main electrical panel (photograph 41). Facing east. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  8. Electromagnetic tracker accuracy in the CyberKnife suite

    NASA Astrophysics Data System (ADS)

    Wilson, Emmanuel; Slack, Rebecca; Banovac, Filip; Dieterich, Sonja; Zhang, Hui; Cleary, Kevin

    2006-03-01

    Electromagnetic trackers have found inroads into medical applications as a tool for navigation in recent years. Their susceptibility to interference from both electromagnetic and ferromagnetic sources have prompted several accuracy assessment studies in past years. To the best of our knowledge, this is the first accuracy study conducted to characterize measurement accuracy of an NDI AURORA electromagnetic tracker within a CyberKnife radiosurgery suite. CyberKnife is a frameless, stereotactic radiosurgery device used to ablate tumors within the brain, spine and in recent years, the chest and abdomen. This paper uses a data collection protocol to collect uniformly distributed data points within a subset of the AURORA measurement volume in a CyberKnife suite. The key aim of the study is to determine the extent to which large metal components of the CyberKnife stereotactic radiosurgery device and robot mount contribute to overall system performance for the AURORA electromagnetic device. A secondary goal of the work is to determine the variation in accuracy and device behavior with the presence of ionizing radiation when the LINAC is turned on.

  9. The Shoemaker's Knife--An Approach of the Polya Type.

    ERIC Educational Resources Information Center

    Libeskind, Shlomo; Lott, Johnny W.

    1984-01-01

    Archimedes' shoemaker's knife problem is interesting in its own right and also allows the demonstration of heuristic teaching ideas and a different method of doing a routine construction. The focus in the article is on the thought processes involved and questions asked when attempting proofs with the problem. (MNS)

  10. "Fist, Stick, Knife, Gun": Getting Real in Upward Bound.

    ERIC Educational Resources Information Center

    Pace, Barbara G.; Adkins, Theresa A.

    2002-01-01

    Describes how a teacher found literature for Upward Bound students. Presents Geoffrey Canada's "Fist, Stick, Knife, Gun: A Personal History of Violence in America" as a nonfiction work to provide clarity and connections that might not have been available in a fictional work, yet it had elements of literary fiction that made the text engaging. (SG)

  11. Investigation of waste glass pouring behavior over a knife edge

    SciTech Connect

    Ebadian, M.A.

    1998-01-01

    The development of vitrification technology for converting radioactive waste into a glass solid began in the early 1960s. Some problems encountered in the vitrification process are still waiting for a solution. One of them is wicking. During pouring, the glass stream flows down the wall of the pour spout until it reaches an angled cut in the wall. At this point, the stream is supposed to break cleanly away from the wall of the pour spout and fall freely into the canister. However, the glass stream is often pulled toward the wall and does not always fall into the canister, a phenomenon known as wicking. Phase 1 involves the assembly, construction, and testing of a melter capable of supplying molten glass at operational flow rates over a break-off point knife edge. Phase 2 will evaluate the effects of glass and pour spout temperatures as well as glass flow rates on the glass flow behavior over the knife edge. Phase 3 will identify the effects on wicking resulting from varying the knife edge diameter and height as well as changing the back-cut angle of the knife edge. The following tasks were completed in FY97: Design the experimental system for glass melting and pouring; Acquire and assemble the melter system; and Perform initial research work.

  12. Strong alkalinization of Chara cell surface in the area of cell wall incision as an early event in mechanoperception.

    PubMed

    Bulychev, Alexander A; Alova, Anna V; Bibikova, Tatiana N

    2013-11-01

    Mechanical wounding of cell walls occurring in plants under the impact of pathogens or herbivores can be mimicked by cell wall incision with a glass micropipette. Measurements of pH at the surface of Chara corallina internodes following microperforation of cell wall revealed a rapid (10-30s) localized alkalinization of the apoplast after a lag period of 10-20s. The pH increase induced by incision could be as large as 3 pH units and relaxed slowly, with a halftime up to 20min. The axial pH profile around the incision zone was bell-shaped and localized to a small area, extending over a distance of about 100μm. The pH response was suppressed by lowering cell turgor upon the replacement of artificial pond water (APW) with APW containing 50mM sorbitol. Stretching of the plasma membrane during its impression into the cell wall defect is likely to activate the Ca(2+) channels, as evidenced from sensitivity of the incision-induced alkalinization to the external calcium concentration and to the addition of Ca(2+)-channel blockers, such as La(3+), Gd(3+), and Zn(2+). The maximal pH values attained at the incision site (~10.0) were close to pH in light-dependent alkaline zones of Chara cells. The involvement of cytoskeleton in the origin of alkaline patch was documented by observations that the incision-induced pH transients were suppressed by the inhibitors of microtubules (oryzalin and taxol) and, to a lesser extent, by the actin inhibitor (cytochalasin B). The results indicate that the localized increase in apoplastic pH is an early event in mechanoperception and depends on light, cytoskeleton, and intracellular calcium. PMID:23850637

  13. Knife mill operating factors effect on switchgrass particle size distributions

    SciTech Connect

    Bitra, V.S.P.; Womac, A.R.; Yang, Y.T.; Igathinathane, C.; Miu, P.I; Chevanan, Nehru; Sokhansanj, Shahabaddine

    2009-06-01

    Biomass particle size impacts handling, storage, conversion, and dust control systems. Switchgrass (Panicum virgatum L.) particle size distributions created by a knife mill were determined for integral classifying screen sizes from 12.7 to 50.8 mm, operating speeds from 250 to 500 rpm, and mass input rates from 2 to 11 kg/min. Particle distributions were classified with standardized sieves for forage analysis that included horizontal sieving motion with machined-aluminum sieves of thickness proportional to sieve opening dimensions. Then, a wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Correlation coefficient of geometric mean length with knife mill screen size, feed rate, and speed were 0.872, 0.349, and 0.037, respectively. Hence, knife mill screen size largely determined particle size of switchgrass chop. Feed rate had an unexpected influence on particle size, though to a lesser degree than screen size. The Rosin Rammler function fit the chopped switchgrass size distribution data with an R2 > 0.982. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Uniformity coefficient was more than 4.0, which indicated a large assortment of particles and also represented a well-graded particle size distribution. Knife mill chopping of switchgrass produced strongly fine skewed mesokurtic particles with 12.7 25.4 mm screens and fine skewed mesokurtic particles with 50.8 mm screen. Results of this extensive analysis of particle sizes can be applied to selection of knife mill operating parameters to produce a particular size of switchgrass chop, and will serve as a guide for relations among the various analytic descriptors of biomass particle distributions.

  14. The technical evolution of gamma knife radiosurgery for arteriovenous malformations.

    PubMed

    Lunsford, L Dade; Niranjan, Ajay; Kano, Hideyuki; Kondziolka, Douglas

    2013-01-01

    Gamma Knife stereotactic radiosurgery was first applied for the treatment of an intracranial arteriovenous malformation (AVM) in 1968. Using biplane angiography to target a small-volume, deep-seated lesion, photons were cross-fired on the pathological shunt. The AVM was obliterated within 3 years. This began a cautious introduction of Gamma Knife radiosurgery in the 1970s. As the Gamma Knife technology spread to sites in Europe, South America and the USA in the 1980s, AVM radiosurgery became a primary indication. During the early years the usual standard was to deliver a single radiosurgical isocenter to the target defined by 2-dimensional angiography. Most patients had small-volume AVMs unsuitable for surgical excision. Over time the technique of Gamma Knife AVM surgery evolved to include: careful patient selection, discussion of appropriate treatment strategies, anticonvulsant administration for lobar locations and intraoperative targeting using both high-resolution axial plane imaging--usually magnetic resonance imaging--coupled with biplane digital subtraction angiography. High-speed computer dose planning integrated with more detailed imaging strategies facilitated conformal radiation delivery in a single treatment session coupled with high selectivity of the dose delivered. Multiple isocenters became routine. Long-term follow-up care included serial imaging evaluations to assess the response and to detect complications. Imaging was critical to confirm the desired radiobiological response--complete obliteration. Long-term follow-up after obliteration confirmed that AVM radiosurgery had a high success rate for properly selected patients and a risk-benefit profile that substantiated patient safety. Twenty-year results after Gamma Knife radiosurgery for AVMs are currently available. Established roles have been found for pediatric cases and for larger-volume AVMs unsuitable for surgical removal. The role and technique of embolization prior to radiosurgery continue

  15. Visualizing morphological changes of clear corneal cataract incisions with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Rao, Bin; Zhang, Jun; Taban, Mehran; McDonnell, Peter J.; Chen, Zhongping

    2004-07-01

    Dynamic morphological changes of clear corneal cataract incisions are studied with Optical Coherence Tomography (OCT). Two opposite types of dynamic incision wound behaviors are documented. A stable incision angle range is found to be existent for single-planed, clear corneal cataract incisions. When well pressurized, incision angles within this stable range result in well-apposed incision edges that resist gapping while incision angles falling outside this range have a larger tendency for wound leakage. It is also shown that a two-planed incision can effectively expand the stable range. For incision angles outside the stable range, the farther the incision angle is away from stable range, the larger the gap between incision wound edges when well pressurized. Thus, incision construction method has a major impact on the self-sealing capability of the incision wounds. In this investigation, OCT has been demonstrated as an effective modality for imaging and monitoring corneal surgery.

  16. Detrital Zircon Record of Colorado River Incision

    NASA Astrophysics Data System (ADS)

    Kimbrough, D.; Grove, M.; Gehrels, G.; Dorsey, R.; House, K. P.; Howard, K.; Pearthree, P. A.; Spencer, J. E.; Mahoney, B.

    2007-05-01

    The Colorado River is a large, youthful, unequilibrated continental drainage system the base-level for which was established rather abruptly between 5 and 6 million years ago in conjunction with Gulf of California rifting and establishment of the modern river course through the western Grand Canyon and lower Colorado river region. New laser ablation ICPMS detrital zircon U-Pb analyses (~3000) from ~40 samples provide insight into details relating to the cause, timing and consequences of river inception. These samples encompass (1) the modern Colorado River delta, (2) major tributaries including the Green, "Grand", San Juan, Little Colorado and Gila rivers (3) late Miocene to Pliocene sediments along the lower Colorado (4) late Miocene to Pleistocene deltaic and fluvial sediments of the Imperial and Palm Spring Groups in the western Salton Trough, and (5) late Miocene- early Pliocene Bidahochi Formation of eastern Arizona. Data from the western Salton Trough and modern delta yield strata yield remarkably homogeneous age distributions that indicate there was little evolution in Colorado River sediment composition since 5.3 Ma. Detrital zircon is dominated by a mix of local southwest US cratonal basement (1.7 and 1.4 Ga) plus reworked supracrustal sequences of the Colorado Plateau that provide Neoproterozoic, 1.1 Ga, and early Paleozoic zircons. A relative paucity of Grenville-age grains in the earliest part of the delta sequence may reflect an early stage of the modern river prior to deep incision through Colorado Plateau erg deposits. The strong homogeneity of the detrital zircon record from late Miocene to the present is consistent with the `lake spillover model' for inception and integration of the modern Colorado River drainage. Abrupt integration of the lower Colorado River after 5.6 Ma is clearly recorded by detrital zircon ages from the laucustrine Bouse Formation and Bullhead alluvium aggradational package. Fluvial-laucustrine deposits of the Bidahochi

  17. Comparison of O-Type HybridKnife to Conventional Knife in Endoscopic Submucosal Dissection for Gastric Mucosal Lesions.

    PubMed

    Huang, Rui; Yan, Honglin; Ren, Gui; Pan, Yanglin; Zhang, Linhui; Liu, Zhiguo; Guo, Xuegang; Wu, Kaichun

    2016-03-01

    Endoscopic submucosal dissection (ESD) has been accepted as a minimal invasive alternative to surgery for localized superficial gastrointestinal neoplasms recently. However, the procedure remains to be technically challenging and time consuming. A new dissecting knife with partially insulated tip has been recently developed with built-in injection capability. The purpose of this study was to investigate whether the efficiency of ESD procedure could be improved with this new device. A total of 78 patients, who underwent ESD with gastric mucosal lesions including flat type polyps, adenoma or early gastric cancer, were randomly assigned to either ESD with O-type HybridKnife or conventional ESD knives without waterjet. Procedure time and related factors of ESD were analyzed. ESD procedure time was 43.0 (interquartile range, IQR 27.0-60.0) minutes in HybridKnife group compared to 60.5 (IQR 44.0-86.3) minutes in the control group (P = 0.001). There was no difference in the clinical outcome and the adverse event rate. The former demonstrated more favorable results in lesions ≤4 cm of specimen size (P ≤ 0.0001) and when located in the distal stomach (P = 0.001), also in lesions with fibrosis (P = 0.008). Multivariate regression analysis showed that O-type Knife (P ≤ 0.0001), specimen size (P ≤ 0.0001), and fibrosis (P ≤ 0.0001) were independent predictors of procedure time. The O-type HybridKnife yielded faster procedure time compared to the conventional knives in gastric ESD with a similar safety profile. PMID:27043675

  18. Comparison of O-Type HybridKnife to Conventional Knife in Endoscopic Submucosal Dissection for Gastric Mucosal Lesions

    PubMed Central

    Huang, Rui; Yan, Honglin; Ren, Gui; Pan, Yanglin; Zhang, Linhui; Liu, Zhiguo; Guo, Xuegang; Wu, Kaichun

    2016-01-01

    Abstract Endoscopic submucosal dissection (ESD) has been accepted as a minimal invasive alternative to surgery for localized superficial gastrointestinal neoplasms recently. However, the procedure remains to be technically challenging and time consuming. A new dissecting knife with partially insulated tip has been recently developed with built-in injection capability. The purpose of this study was to investigate whether the efficiency of ESD procedure could be improved with this new device. A total of 78 patients, who underwent ESD with gastric mucosal lesions including flat type polyps, adenoma or early gastric cancer, were randomly assigned to either ESD with O-type HybridKnife or conventional ESD knives without waterjet. Procedure time and related factors of ESD were analyzed. ESD procedure time was 43.0 (interquartile range, IQR 27.0–60.0) minutes in HybridKnife group compared to 60.5 (IQR 44.0–86.3) minutes in the control group (P = 0.001). There was no difference in the clinical outcome and the adverse event rate. The former demonstrated more favorable results in lesions ≤4 cm of specimen size (P ≤ 0.0001) and when located in the distal stomach (P = 0.001), also in lesions with fibrosis (P = 0.008). Multivariate regression analysis showed that O-type Knife (P ≤ 0.0001), specimen size (P ≤ 0.0001), and fibrosis (P ≤ 0.0001) were independent predictors of procedure time. The O-type HybridKnife yielded faster procedure time compared to the conventional knives in gastric ESD with a similar safety profile. PMID:27043675

  19. The stream channel incision syndrome and water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watershed development often triggers channel incision, which accounts for 60-90% of sediments leaving many disturbed watersheds. Impacts of such incision on water quality processes and the implication of such impairment on stream biota are relevant to issues associated with establishing total maxim...

  20. Modeling the Evolution of Incised Streams: III. Model Application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incision and ensuing widening of alluvial stream channels is widespread in the midsouth and midwestern United States and represents an important form of channel adjustment. Two accompanying papers have presented a robust computational model for simulating the long-term evolution of incised and resto...

  1. Single-incision laparoscopic sigmoidectomy and rectopexy case series.

    PubMed

    Adair, James; Gromski, Mark A; Nagle, Deborah

    2011-08-01

    Single-incision laparoscopic surgery has recently been investigated as a novel approach to colorectal pathology. This article describes 3 cases of single-incision laparoscopic sigmoidectomy with rectopexy for the treatment of rectal prolapse. We demonstrate our surgical approach and results from these initial patients treated with this novel technique. PMID:21810504

  2. Wound Hypoxia in Deep Tissue after Incision in the Rats

    PubMed Central

    Kang, Sinyoung; Lee, Dongchul; Theusch, Brett E.; Arpey, Christopher J.; Brennan, Timothy J.

    2013-01-01

    Our previous studies using rat models of incisional pain have demonstrated that tissue lactate levels increase and pH decreases for several days after incision, suggesting the presence of an ischemic-like condition. The purpose of this study was to evaluate the time course and the extent of tissue hypoxia that develops in incised muscle and skin. We directly measured oxygen tension at several time points after incisions of the gastrocnemius muscle, the paraspinal skin, and the plantar hindpaw in anesthetized rats using an oxygen-sensitive microelectrode. In vivo hypoxia of the incised tissues was also evaluated immunohistochemically using a hypoxia marker pimonidazole hydrochloride. To minimized inter-subject variability, unincised contralateral tissues were used as a control. Tissue oxygen tension was decreased in both skeletal muscle and skin compared to control, for several days after incision: when measured directly, oxygen tension decreased immediately and remained low for several days after incisions. Pimonidazole immunostaining revealed hypoxic areas in incised muscle and skin for several days. By postoperative day 10, tissue oxygen tension recovered to that of control tissue. These results support the evidence that a hypoxic condition is present in deep tissue after incisions and that an ischemic-like mechanism may contribute to postoperative pain. PMID:23926943

  3. Incision into the eastern Andean Plateau during Pliocene cooling.

    PubMed

    Lease, Richard O; Ehlers, Todd A

    2013-08-16

    Canyon incision into mountain topography is commonly used as a proxy for surface uplift driven by tectonic or geodynamic processes, but climatic changes can also instigate incision. The ~1250-kilometer (km)-long eastern margin of the Andean Plateau hosts a series of 1.5- to 2.5-km-deep canyons that cross major deformation zones. Using (U-Th)/He thermochronology, we document a transition from Miocene faulting to Pliocene canyon incision across the northeastern plateau margin. Regionally, widespread Pliocene incision into the eastern plateau margin is concurrent with a shift in global climate from early Pliocene warmth to late Pliocene cooling. Enhanced moisture transport onto the Andean Plateau driven by sea surface temperature changes during cooling is the likely pacemaker for canyon incision. PMID:23950534

  4. First Canadian experience with robotic single-incision pyeloplasty: Comparison with multi-incision technique

    PubMed Central

    Law, Jeffrey; Rowe, Neal; Archambault, Jason; Nastis, Sofia; Sener, Alp; Luke, Patrick P.

    2016-01-01

    Introduction: We compared the outcomes of single-incision, robot-assisted laparoscopic pyeloplasty vs. multiple-incision pyeloplasty using the da Vinci robotic system. Methods: We reviewed all consecutive robotic pyeloplasties by a single surgeon from January 2011 to August 2015. A total of 30 procedures were performed (16 single:14 multi-port). Two different single-port devices were compared: the GelPort (Applied Medical, Rancho Santa Margarita, CA) and the Intuitive single-site access port (Intuitive Surgical, Sunnyvale, CA). Results: Patient demographics were similar between the two groups. Mean operating time was similar among the single and multi-port groups (225.2 min vs. 198.9 minutes [p=0.33]). There was no significant difference in length of hospital stay in either group (86.2 hr vs. 93.2 hr [p=0.76]). There was no difference in success rates or postoperative complications among groups. Conclusions: Single-port robotic pyeloplasty is non-inferior to multiple-incision robotic surgery in terms of operative times, hospitalization time, success rates, and complications. Verifying these results with larger cohorts is required prior to the wide adoption of this technique. Ongoing objective measurements of cosmesis and patient satisfaction are being evaluated. PMID:27217850

  5. Influence of Incision Location on Transmitter Loss, Healing, Incision Lengths, Suture Retention, and Growth of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greggory L.; Woodley, Christa M.; Deters, Katherine A.

    2010-05-11

    In this study, conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, we measured differences in survival and growth, incision openness, transmitter loss, wound healing, and erythema among abdominal incisions on the linea alba, lateral and parallel to the linea alba (muscle-cutting), and following the underlying muscle fibers (muscle-sparing). A total of 936 juvenile Chinook salmon were implanted with both Juvenile Salmon Acoustic Tracking System transmitters (0.43 g dry) and passive integrated transponder tags. Fish were held at 12°C (n = 468) or 20°C (n = 468) and examined once weekly over 98 days. We found survival and growth did not differ among incision groups or between temperature treatment groups. Incisions on the linea alba had less openness than muscle-cutting and muscle-sparing incisions during the first 14 days when fish were held at 12°C or 20°C. Transmitter loss was not different among incision locations by day 28 when fish were held at 12°C or 20°C. However, incisions on the linea alba had greater transmitter loss than muscle-cutting and muscle-sparing incisions by day 98 at 12°C. Results for wound closure and erythema differed among temperature groups. Results from our study will be used to improve fish-tagging procedures for future studies using acoustic or radio transmitters.

  6. A noninvasive eye fixation monitoring system for CyberKnife radiotherapy of choroidal and orbital tumors

    SciTech Connect

    Daftari, I. K.; Petti, P. L.; Larson, D. A.; O'Brien, J. M.; Phillips, T. L.

    2009-03-15

    A new noninvasive monitoring system for fixing the eye has been developed to treat orbital and choroidal tumors with CyberKnife-based radiotherapy. This device monitors the eye during CT/MRI scanning and during treatment. The results of this study demonstrate the feasibility of the fixation light system for CyberKnife-based treatments of orbital and choroidal tumors and supports the idea that larger choroidal melanomas and choroidal metastases could be treated with CyberKnife without implanting fiducial markers.

  7. Testing bedrock incision models: Holocene channel evolution, High Cascades, Oregon

    NASA Astrophysics Data System (ADS)

    Sweeney, K. E.; Roering, J. J.; Fonstad, M. A.

    2013-12-01

    There is abundant field evidence that sediment supply controls the incision of bedrock channels by both protecting the bed from incision and providing tools to incise the bed. Despite several theoretical models for sediment-dependent bedrock abrasion, many investigations of natural channel response to climatic, lithologic, or tectonic forcing rely on the stream power model, which does not consider the role of sediment. Here, we use a well-constrained fluvial channel cut into a Holocene lava flow in the High Cascades, Oregon to compare incision predictions of the stream power model and of the full physics of theoretical models for saltation-abrasion incision by bedload and suspended load. The blocky andesite of Collier lava flow erupted from Collier Cone ~1500 years ago, paving over the existing landscape and erasing fine-scale landscape dissection. Since the eruption, a 6 km stream channel has been incised into the lava flow. The channel is comprised of three alluvial reaches with sediment deposits up to 2 m thick and two bedrock gorges with incision of up to 8 m, with larger magnitude incision in the upstream gorge. Abraded forms such as flutes are present in both gorges. Given the low magnitude and duration of modern snowmelt flow in the channel, it is likely that much of the incision was driven by sediment-laden outburst floods from the terminus of Collier Glacier, which is situated just upstream of the lava flow and has produced two outburst floods in the past 100 years. This site is well suited for comparing incision models because of the relatively uniform lithology of the lava flow and our ability to constrain the timing and depth of incision using the undissected lava surface above the channel as an initial condition. Using a simple finite difference scheme with airborne-Lidar-derived pre-incision topography as an initial condition, we predict incision in the two gorges through time with both stream power and sediment-dependent models. Field observations

  8. A Simple Approach to Specimen Retrieval via Posterior Colpotomy Incision

    PubMed Central

    Menderes, Gulden; Tower, Amanda M.; Silasi, Dan-Arin; Azodi, Masoud

    2015-01-01

    Introduction: Posterior colpotomy incision for specimen retrieval is infrequently used in gynecologic laparoscopic surgery unless a concomitant hysterectomy is performed. We aim to describe a simple and unique technique for creating the colpotomy incision and to describe intraoperative and postoperative outcomes. Methods: Fifty patients underwent adnexal specimen retrieval through a posterior colpotomy incision. After devascularization and detachment of the adnexal specimen, the posterior cul-de-sac was visualized. The colpotomy incision was created by introducing a 12- or 15-mm laparoscopic trocar through the vagina into the posterior vaginal fornix under direct visualization. Specimens were placed into laparoscopic bags and removed through the vagina. The colpotomy incision was closed vaginally. Charts were reviewed for intraoperative and postoperative outcomes. Results: Twenty-nine women underwent adnexal surgery for an adnexal mass, 14 women underwent surgery for pelvic pain, and 7 women underwent adnexal surgery for primary prevention of malignancy. The specimens removed ranged in size from 2 to 16 cm (mean 5.7). The mean time patients were under anesthesia was 103 minutes (SD 57.3). There were no operative complications related to the colpotomy incision and no cases of postoperative vaginal cellulitis or pelvic infection were reported. Only 1 woman with a prior vaginal delivery reported dyspareunia postoperatively. Conclusion: This simple technique for posterior colpotomy incision can easily be added to the gynecologic surgeon's armamentarium and can be safely used for most women. PMID:25901107

  9. Development of knife-edge ridges on ion-bombarded surfaces

    NASA Astrophysics Data System (ADS)

    Holmes-Cerfon, Miranda; Zhou, Wei; Bertozzi, Andrea L.; Brenner, Michael P.; Aziz, Michael J.

    2012-10-01

    We demonstrate in both laboratory and numerical experiments that ion bombardment of a modestly sloped surface can create knife-edge like ridges with extremely high slopes. Small pre-fabricated pits expand under ion bombardment, and the collision of two such pits creates knife-edge ridges. Both laboratory and numerical experiments show that the pit propagation speed and the precise shape of the knife edge ridges are universal, independent of initial conditions, as has been predicted theoretically. These observations suggest a method of fabrication in which a surface is pre-patterned so that it dynamically evolves to a desired target pattern made of knife-edge ridges.

  10. A knife-edge array field emission cathode

    SciTech Connect

    Lee, B.

    1994-08-01

    many cathode applications require a new type of cathode that is able to produce short pulsed electron beams at high emission current. Gated field emitter arrays of micrometer size are recognized as candidates to meet this need and have become the research focus of vacuum microelectronics. Existing fabrication methods produce emitters that are limited either in frequency response or in current emission. One reason is that the structure of these emitters are not sufficiently optimized. In this study, the author investigated the factors that affect the performance of field emitters. An optimum emitter structure, the knife-edge field emitter array, was developed from the analysis. Large field enhancement factor, large effective emission area, and small emitter capacitance are the advantages of the structure. The author next explored various options of fabricating the knife-edge emitter structure. He proposed a unique thin film process procedure and developed the fabrication techniques to build the emitters on (110) silicon wafers. Data from the initial cathode tests showed very low onset voltages and Fowler-Nordheim type emission. Emission simulation based on the fabricated emitter structure indicated that the knife-edge emitter arrays have the potential to produce high performance in modulation frequency and current emission. Several fabrication issues that await further development are discussed and possible solutions are suggested.

  11. Therapeutic advances: Single incision laparoscopic hepatopancreatobiliary surgery

    PubMed Central

    Chang, Stephen Kin Yong; Lee, Kai Yin

    2014-01-01

    Single-port laparoscopic surgery (SPLS) is proposed to be a step towards minimizing the invasiveness of surgery, and has since gained popularity in several surgical sub-specialties including hepatopancreatobiliary surgery. SPLS has since been applied to cholecystectomy, liver resection as well as pancreatectomy for a multitude of pathologies. Benefits of SPLS over conventional multi-incision laparoscopic surgery include improved cosmesis and potentially post-operative pain at specific time periods and extra-umbilical sites. However, it is also associated with longer operating time, increased rate of complications, and increased rate of port-site hernia. There is no significant difference between length of hospital stay. SPLS has a significant learning curve that affects operating time, rate of conversion and rate of complications. In this article, we review the literature on SPLS in hepatobiliary surgery - cholecystectomy, hepatectomy and pancreatectomy, and offer tips on overcoming potential technical obstacles and minimizing the complications when performing SPLS - surgeon position, position of port and instruments, instrument crossing position, standard hand grip vs reverse hand grip, snooker cue guide position, prevention of incisional hernia. SPLS is a promising direction in laparoscopic surgery, and we recommend step-wise progression of applications of SPLS to various hepatopancreatobiliary surgeries to ensure safe adoption of the surgical technique. PMID:25339820

  12. Direct measures of mechanical energy for knife mill size reduction

    SciTech Connect

    Bitra, V.S.P.; Womac, A.R.; Igathinathane, C.; Miu, P.I; Yang, Y.T.; Smith, D.R.; Chevanan, Nehru; Sokhansanj, Shahabaddine

    2009-08-01

    Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be 0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

  13. MTF measurement of IRFPA based on double-knife edge scanning method

    NASA Astrophysics Data System (ADS)

    Ying, Cheng-ping; Wu, Bin; Wang, Heng-fei; Shi, Xue-shun; Liu, Hong-yuan

    2013-09-01

    Modulation transfer function (MTF) is one of the most important parameters of infrared focal plane array (IRFPA). A double-knife edge scanning method is proposed for MTF measurement of IRFPA. In this method, a double-knife edge was used as a target, and the IRFPA under test was positioned in the focal plane of the imaging optical system by a 3-axis translation stage. With an IRFPA data acquisition system, the image of the double-knife edge was restored. By scanning in the direction orthogonal to the double-knife edge image, edge spread function (ESF) curve of each pixel swept across the knife-edge image was obtained. MTF could be calculated from the subsequent fitting, differential and Fourier transformation procedures. With double-knife edge scanning, two ESF curves of double-knife edge were obtained simultaneously, and symmetry of the two ESF curves could be used to evaluate the verticality between photosensitive surface of IRFPA and optical axis of the double-knife edge imaging system. In addition, this method can be used to judge the existing of interference from outside such as vibration, stray light and electrical noise. A measurement facility for IRFPA's MTF based on double-knife edge scanning method was also established in this study. The facility is composed of double-knife edge imaging optical system, 3-axis translation stage and data acquisition system, et al. As the kernel of the facility, the double-knife edge imaging optical system mainly comprises two symmetrical parabolic mirrors coating with reflective material, and the magnification of the optical system is 1 with an operation wavelength range of (1˜14) μm.

  14. 11. REPRESENTATIVE DETAIL VIEW OF RAILING (INCISED PATTERN IS USED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. REPRESENTATIVE DETAIL VIEW OF RAILING (INCISED PATTERN IS USED ON BOTH SIDES OF THE PARAPET) - Central of Georgia Railway, Bay Street Viaduct, U.S. 17 & Bay Street, spanning Central of Georgia Railroad, Savannah, Chatham County, GA

  15. Single-Incision Laparoscopic Combined Cholecystectomy and Appendectomy

    PubMed Central

    Chen, Yongsheng; Kong, Jing

    2014-01-01

    Background and Objectives: Single-incision laparoscopic surgery is becoming more widely used, but few combined procedures have been reported. Herein we share our experience with single-incision laparoscopic combined cholecystectomy and appendectomy. Methods: We reviewed data from 26 patients who underwent single-incision laparoscopic combined cholecystectomy and appendectomy between May 1, 2009 and June 1, 2013 at Shengjing Hospital. All the procedures were performed with conventional laparoscopic instruments placed through a single operating portal of entry created within the umbilicus. Results: All the operations were successfully completed without conversion to conventional laparoscopic or open surgery. No intraoperative complications occurred. Patients were satisfied with the therapeutic and cosmetic outcomes. Conclusions: Single-incision laparoscopic combined cholecystectomy and appendectomy appear to be a technically feasible alternative to the standard laparoscopic procedure in simultaneous management of coexisting benign gallbladder and appendix pathologies. Larger studies are required to confirm these findings. PMID:25392641

  16. Cyclic steps incised on experimental bedrock

    NASA Astrophysics Data System (ADS)

    Yokokawa, M.; Kyogoku, A.; Kotera, A.; Izumi, N.

    2013-12-01

    the step shape has been predicted by the mathematical model (Izumi et al., 2012). Among three cases of sediment supply: 1 g/sec, 3 g/sec, and 6 g/sec with fixed water discharge (52 g/sec), the erosion rate was maximized in the cases of the sediment supply of 3 g/sec both in the cement-sand-water ratios of 2:150:50 and 3:150:50. The erosion rate is higher in the case of the moderate amount of sediment supply rather than in the case of the largest amount of sediment supply in which the alluvial cover effect inhibited erosion. This result is consistent with that observed in previous studies (Sklar & Dietrich, 2004; Johnson & Whipple, 2010). References Izumi, N., Yokokawa, M. & Parker G. 2012. Cyclic step morphology formed on bedrock. Annual Journal of Hydraulic Engineering 68(4) : I_955-I_960. Johnson, J.P.L. & Whipple, K.X. 2010. Evaluating the controls of shear stress, sediment supply, alluvial cover, and channel morphology on experimental bedrock incision rate. Journal of Geophysical Research 115, F02018, doi:10.1029/2009JF001335. Sklar, L.S. & Dietrich, W.E. 2004. A mechanistic model for river incision into bedrock by sultating bedload. Water Resources Re-search 40, W06301, doi:10.1029/2003WR002496.

  17. Incision of the Colorado River in southern Utah - insights from channel profiles, local incision rates, and modeling of lithologic controls

    NASA Astrophysics Data System (ADS)

    Cook, K.; Whipple, K.; Heimsath, A.

    2009-04-01

    The Colorado River and its tributaries in southern Utah and northern Arizona provide an opportunity to study the propagation of bedrock incision through a large heterogeneous fluvial network, as the system is continuing to adjust to the baselevel fall responsible for the Grand Canyon. Although the carving of the Grand Canyon was largely complete by ~1 Ma, the canyon ends at Lee's Ferry and the incision history of Colorado River system upstream of the associated large knickpoint has been the subject of debate. In conjunction with existing incision rate estimates based on the dating of strath terraces, we use longitudinal profiles of the Colorado and tributaries between Marble Canyon and Cataract Canyon to investigate the incision history of the Colorado in this region. We find that all but two of the tributaries in this region steepen as they enter the Colorado River. The consistent presence of oversteepened reaches with similar elevation drops in the lower section of these channels, and their coincidence within a corridor of high local relief along the Colorado, suggest that the tributaries are steepening in response to an episode of increased incision rate on the Colorado River. This analysis is supported by available incision rate data, as the spatial distribution of incision rates predicted by the channel profiles is consistent with existing rate estimates. The two analyzed tributaries that show no evidence for this incision pulse, Trachyte Creek and Bullfrog Creek, have smoothly concave profiles and do not contain knickpoints. In order to evaluate the significance of these anomalous channel profiles, we measure in situ 10Be concentrations on four gravel-covered strath surfaces elevated from 1 m to 110 m above Trachyte Creek. The surfaces yield exposure ages that range from approximately 2.5 ka to 267 ka and suggest incision rates that vary between 350 and 600 m/my. These incision rates are similar to other rates determined within the high-relief corridor, and

  18. Differential stream incision in the Oregon Coast Range

    SciTech Connect

    Personius, S.F. )

    1993-04-01

    Stream incision rates are used to determine rates and styles of late quaternary deformation of the Oregon Coast Range, in the forearc of the Cascadia subduction zone. Bedrock incision rates were obtained along westward-flowing streams, from the Umpqua river in a central western Oregon to the North Fork Nehalem River in northwestern Oregon. Incision measurements were restricted mostly to nontidal reaches that are more than 20--40 km inland from the coast, to exclude areas affected by eustatic changes in sea level. Most strath ages were determined indirectly by radiocarbon dating of detrital charcoal sampled from alluvium that overlies the straths. A few incision measurements were made on straths that underlie higher, less well preserved terrace remnants. The ages of some of these higher straths were determined by thermoluminescence (TL) dating. These ages are less constrained than those established with radiocarbon dating, but they appear to yield similar rates of incision. The difference in age between the overlying sediments and the age of strath abandonment is unknown, but several lines of evidence indicate that sediment mobilization and deposition most likely were concurrent with cutting of the strath. Numerous strath height measurements indicate that rates of incision are fairly uniform along many kilometers of individual Coast Range streams, regardless of the type of bedrock traversed. Such uniform incision rates do not support the landward tilting of the Coast Range as postulated by other studies. However, regional differences in incision apparent in northern Oregon may be explained by differential uplift caused by north-south compression in the overriding North American plate, or by changes in the geometry of the subducting Juan de Fuca plate.

  19. Orchiopexy through a single high transverse scrotal incision

    PubMed Central

    Khirallah, Mohammad G.; Elafifi, Mahmoud A.; Elbatarny, Akram M.; Elsharaby, Ahmed M.

    2015-01-01

    Background: Palpable Undescended Testis (PUT) represents a common paediatric problem in many premature and some mature infants. There are several surgical techniques to correct PUT either through combined inguinal and scrotal incision or single transverse scrotal incision. This study assessed single high transverse scrotal incision for the management of PUT as regards to feasibility, postoperative success and final cosmetic results. Materials and Methods: One hundred twenty patients were managed at the Paediatric Surgery Department of Tanta University Hospital with PUT during the period from March 2010 to March 2014. They were all operated at the age of 6-12 months. We excluded recurrent cases, and cases older than 12 months. Through high transverse scrotal incision, the layers were divided, and the canal entered through the external ring, dissecting the PUT and bringing it through the incision. Hernia sac, if present, was ligated at the neck. Creation of the dartos pouch was then made through the same incision. All infants were followed-up at 1 month, 2 months and 6 months to detect any re-ascended cases, testicular atrophy and the final cosmetic appearance. Results: A total of 140 PUTs were operated upon in 120 patients. PUT was bilateral in 20 patients, right-sided in 65 cases and left-sided in 35 cases. Thirty testes were located at the external ring; the others were located within the inguinal canal. No cases needed a redo operation, and there was no case of postoperative testicular atrophy. Conclusion: Single high transverse incision was sufficient to deal with PUT especially, in young infants (age 6 months) with no need for conversion in most cases to the traditional two incisions technique, and good long term follow-up and a better cosmetic results. PMID:25659553

  20. Tensile Properties of the Murine Ventral Vertical Midline Incision

    PubMed Central

    Carlson, Mark A.; Chakkalakal, Dennis

    2011-01-01

    Background In clinical surgery, the vertical midline abdominal incision is popular but associated with healing failures. A murine model of the ventral vertical midline incision was developed in order to study the healing of this incision type. Methodology/Principal Findings The strength of the wild type murine ventral abdominal wall in the midline was contained within the dermis; the linea alba made a negligible contribution. Unwounded abdominal wall had a downward trend (nonsignificant) in maximal tension between 12 and 29 weeks of age. The incision attained 50% of its final strength by postoperative day 40. The maximal tension of the ventral vertical midline incision was nearly that of unwounded abdominal wall by postwounding day 60; there was no difference in unwounded vs. wounded maximal tension at postwounding day 120. Conclusions/Significance After 120 days of healing, the ventral vertical midline incision in the wild type mouse was not significantly different from age-matched nonwounded controls. About half of the final incisional strength was attained after 6 weeks of healing. The significance of this work was to establish the kinetics of wild type incisional healing in a model for which numerous genotypes and genetic tools would be available for subsequent study. PMID:21915298

  1. [Incisions for biaxial and coaxial microincision cataract surgery].

    PubMed

    Müller, M; Kohnen, T

    2010-02-01

    Microincision cataract surgery (MICS) represents a new level in the development of cataract surgery. Phacoemulsification with intraocular lens (IOL) implantation via incisions of incision cataract surgery, the advantages of MICS are less corneal astigmatism and fewer corneal surface irregularities, with favorable implications for visual quality and early rehabilitation. In the effort toward smaller incisions, special interest should be given to wound integrity, especially regarding the risk of endophthalmitis. With limited corneal elastic capacity, irreversible expansion of the incision with tissue laceration may occur. Smaller incisions are superior only if they cause less trauma. This requires an optimized relationship between incision size and manipulation during IOL implantation as well as attention to safety issues. MICS offers a platform for new benchmarks in phacoemulsification. PMID:20107810

  2. A geometric analysis of mastectomy incisions: Optimizing intraoperative breast volume

    PubMed Central

    Chopp, David; Rawlani, Vinay; Ellis, Marco; Johnson, Sarah A; Buck, Donald W; Khan, Seema; Bethke, Kevin; Hansen, Nora; Kim, John YS

    2011-01-01

    INTRODUCTION: The advent of acellular dermis-based tissue expander breast reconstruction has placed an increased emphasis on optimizing intraoperative volume. Because skin preservation is a critical determinant of intraoperative volume expansion, a mathematical model was developed to capture the influence of incision dimension on subsequent tissue expander volumes. METHODS: A mathematical equation was developed to calculate breast volume via integration of a geometrically modelled breast cross-section. The equation calculates volume changes associated with excised skin during the mastectomy incision by reducing the arc length of the cross-section. The degree of volume loss is subsequently calculated based on excision dimensions ranging from 35 mm to 60 mm. RESULTS: A quadratic relationship between breast volume and the vertical dimension of the mastectomy incision exists, such that incrementally larger incisions lead to a disproportionally greater amount of volume loss. The vertical dimension of the mastectomy incision – more so than the horizontal dimension – is of critical importance to maintain breast volume. Moreover, the predicted volume loss is more profound in smaller breasts and primarily occurs in areas that affect breast projection on ptosis. CONCLUSIONS: The present study is the first to model the relationship between the vertical dimensions of the mastectomy incision and subsequent volume loss. These geometric principles will aid in optimizing intra-operative volume expansion during expander-based breast reconstruction. PMID:22654531

  3. Water table fluctuations near an incised stream, Walnut Creek, Iowa

    USGS Publications Warehouse

    Schilling, K.E.; Zhang, Y.-K.; Drobney, P.

    2004-01-01

    Incised channels are common features in many agricultural watersheds, but the effects of channel incision on riparian water table conditions have been poorly documented. In this study, we evaluate the water table fluctuations in the floodplain near an incised stream (Walnut Creek, Iowa) and investigate the roles that channel incision and variable recharge play in modifying the water table configuration in the floodplain. Groundwater flows from higher landscape positions towards Walnut Creek under hydraulic gradients that were steepest near the upland/floodplain contact and in the near-stream riparian zone. Annually, water table fluctuations on the floodplain were greatest in wells located 30 m from the creek, midway between the creek and upland. Water levels monitored continuously during a runoff event indicated that bank storage was confined to a narrow zone adjacent to the channel. A steady-state, one-dimensional analytical model was developed to describe the shape of the water table surface near an incised stream and evaluate how variable groundwater recharge and channel bed lowering has affected the shape of the water table surface. Results from this study have implications for managing the riparian buffers of incised streams with successful establishment dependent upon matching buffer vegetation to riparian water table conditions. ?? 2003 Elsevier B.V. All rights reserved.

  4. Two-dimensional light-distribution measurement with a 90 deg cornered knife edge

    NASA Astrophysics Data System (ADS)

    Pernick, B. J.

    1993-07-01

    An aperture-scanning technique for determining a two-dimensional light distribution is described. Results are obtained by moving a wedge-shaped, knife-edge aperture and comparing measurements from adjacent scans. The scanning procedure described herein overcomes deficiencies inherent in alternative methods that use a two-dimensional detector array or one-dimensional motion of a knife-edge aperture.

  5. Study of internal energy flows in dipole vortex beams by knife edge test

    NASA Astrophysics Data System (ADS)

    Singh, Brijesh Kumar; Bahl, Monika; Mehta, Dalip Singh; Senthilkumaran, Paramasivam

    2013-04-01

    The rotation of Poynting vector in dipole vortex beam (DVB) during propagation has been experimentally detected in a knife edge test. The dipole vortex beam is generated, when a collimated laser beam is incident on a phase mask, displayed on spatial light modulator (SLM) in reflection mode. The knife edge test reveals dipole configurations through strikingly distinct intensity intrusions in the geometrical shadow region.

  6. Removing seed coat fragments with a lint cleaner grid bar air knife

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed coat fragments (SCF) in ginned lint cause spinning problems at the textile mill and undesirable defects in finished goods. Work continued on developing an air knife that may help remove SCF from ginned lint. The air knife is mounted on the 1st lint cleaner grid bar of a saw-type lint cleaner,...

  7. Gamma Knife 3-D dose distribution near the area of tissue inhomogeneities by normoxic gel dosimetry

    SciTech Connect

    Isbakan, Fatih; Uelgen, Yekta; Bilge, Hatice; Ozen, Zeynep; Agus, Onur; Buyuksarac, Bora

    2007-05-15

    The accuracy of the Leksell GammaPlan registered , the dose planning system of the Gamma Knife Model-B, was evaluated near tissue inhomogeneities, using the gel dosimetry method. The lack of electronic equilibrium around the small-diameter gamma beams can cause dose calculation errors in the neighborhood of an air-tissue interface. An experiment was designed to investigate the effects of inhomogeneity near the paranosal sinuses cavities. The homogeneous phantom was a spherical glass balloon of 16 cm diameter, filled with MAGIC gel; i.e., the normoxic polymer gel. Two hollow PVC balls of 2 cm radius, filled with N{sub 2} gas, represented the air cavities inside the inhomogeneous phantom. For dose calibration purposes, 100 ml gel-containing vials were irradiated at predefined doses, and then scanned in a MR unit. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. Dose distributions are the results of a single shot of irradiation, obtained by collimating all 201 cobalt sources to a known target in the phantom. Both phantoms were irradiated at the same dose level at the same coordinates. Stereotactic frames and fiducial markers were attached to the phantoms prior to MR scanning. The dose distribution predicted by the Gamma Knife planning system was compared with that of the gel dosimetry. As expected, for the homogeneous phantom the isodose diameters measured by the gel dosimetry and the GammaPlan registered differed by 5% at most. However, with the inhomogeneous phantom, the dose maps in the axial, coronal and sagittal planes were spatially different. The diameters of the 50% isodose curves differed 43% in the X axis and 32% in the Y axis for the Z=90 mm axial plane; by 44% in the X axis and 24% in the Z axis for the Y=90 mm coronal plane; and by 32% in the Z axis and 42% in the Y axis for the X=92 mm sagittal plane. The lack of ability of the GammaPlan registered to predict the rapid dose fall off, due

  8. Gamma Knife 3-D dose distribution near the area of tissue inhomogeneities by normoxic gel dosimetry.

    PubMed

    Isbakan, Fatih; Ulgen, Yekta; Bilge, Hatice; Ozen, Zeynep; Agus, Onur; Buyuksarac, Bora

    2007-05-01

    The accuracy of the Leksell GammaPlan, the dose planning system of the Gamma Knife Model-B, was evaluated near tissue inhomogeneities, using the gel dosimetry method. The lack of electronic equilibrium around the small-diameter gamma beams can cause dose calculation errors in the neighborhood of an air-tissue interface. An experiment was designed to investigate the effects of inhomogeneity near the paranosal sinuses cavities. The homogeneous phantom was a spherical glass balloon of 16 cm diameter, filled with MAGIC gel; i.e., the normoxic polymer gel. Two hollow PVC balls of 2 cm radius, filled with N2 gas, represented the air cavities inside the inhomogeneous phantom. For dose calibration purposes, 100 ml gel-containing vials were irradiated at predefined doses, and then scanned in a MR unit. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. Dose distributions are the results of a single shot of irradiation, obtained by collimating all 201 cobalt sources to a known target in the phantom. Both phantoms were irradiated at the same dose level at the same coordinates. Stereotactic frames and fiducial markers were attached to the phantoms prior to MR scanning. The dose distribution predicted by the Gamma Knife planning system was compared with that of the gel dosimetry. As expected, for the homogeneous phantom the isodose diameters measured by the gel dosimetry and the GammaPlan differed by 5% at most. However, with the inhomogeneous phantom, the dose maps in the axial, coronal and sagittal planes were spatially different. The diameters of the 50% isodose curves differed 43% in the X axis and 32% in the Y axis for the Z =90 mm axial plane; by 44% in the X axis and 24% in the Z axis for the Y=90 mm coronal plane; and by 32% in the Z axis and 42% in the Y axis for the X=92 mm sagittal plane. The lack of ability of the GammaPlan to predict the rapid dose fall off, due to the air cavities behind or near the

  9. First experience with a new negative pressure incision management system on surgical incisions after cardiac surgery in high risk patients

    PubMed Central

    2011-01-01

    Background Sternal wound infection remains a serious potential complication after cardiac surgery. A recent development for preventing wound complications after surgery is the adjunctive treatment of closed incisions with negative pressure wound therapy. Suggested mechanisms of preventive action are improving the local blood flow, removing fluids and components in these fluids, helping keep the incision edges together, protecting the wound from external contamination and promoting incision healing. This work reports on our initial evaluation and clinical experience with the Prevena™Incision Management System, a recently introduced new negative pressure wound therapy system specifically developed for treating closed surgical incisions and helping prevent potential complications. We evaluated the new treatment on sternal surgical incisions in patients with multiple co-morbidities and consequently a high risk for wound complications. Methods The Prevena™incision management system was used in 10 patients with a mean Fowler risk score of 15.1 [Range 8-30]. The negative pressure dressing was applied immediately after surgery and left in place for 5 days with a continuous application of -125 mmHg negative pressure. Wounds and surrounding skin were inspected immediately after removal of the Prevena™ incision management system and at day 30 after surgery. Results Wounds and surrounding skin showed complete wound healing with the absence of skin lesions due to the negative pressure after removal of the Prevena™ dressing. No device-related complications were observed. No wound complications occurred in this high risk group of patients until at least 30 days after surgery. Conclusions The Prevena™system appears to be safe, easy to use and may help achieve uncomplicated wound healing in patients at risk of developing wound complications after cardiothoracic surgery. PMID:22145641

  10. A randomised controlled trial of mini incision or conventional incision for saphenous vein harvesting in patients undergoing myocardial revascularization

    PubMed Central

    Gontijo de Deus, Kleber; Diogo Filho, Augusto; Cesar Santos, Paulo

    2016-01-01

    Objective Compare the evolution regarding the complications concerning two types of incision (conventional × mini-incision), for saphenectomy in patients that go under myocardial revascularization or otherwise known as coronary artery bypass surgery. Methods In January 2012 to August 2013, 66 patients were prospectively selected for coronary artery bypass with cardiopulmonary bypass surgery. These were divided into two groups: Conventional and Mini-Incision, with 33 patients in each group chosen in a random fashion and with knowledge of which technique to be used being presented only at the start of the surgery. In the conventional group, the patients received an incision to the lower member of 7–10 cm. The patients in the Mini-Incision group received an incision to the lower member of 3–4 cm, both performed without the use of any special material. Results The groups were similar in terms of clinical data and in the preoperative period. Males made up a greater part of the group with 63.7% and 81.9% in groups C and M, respectively. Among the complications analysed, edema (p = 0.011), hematoma (p = 0.020), dehiscence (p = 0.012) and infection (p = 0.012), were significantly greater in group C when compared to group M. When the matter comes to the variable in relation to the risk of Surgical Site Infections (SSI), no difference was found between the groups. Conclusion Coronary artery bypass surgery with mini-incision for saphenectomy, demonstrated a lower rate for preoperative complications when compared to saphenectomy under conventional incision procedures. PMID:27006766

  11. Fluvial incision into bedrock: Insights from morphometric analysis and numerical modeling of gorges incising glacial hanging valleys (Western Alps, France)

    NASA Astrophysics Data System (ADS)

    Valla, Pierre G.; van der Beek, Peter A.; Lague, Dimitri

    2010-06-01

    Bedrock gorges incising glacial hanging valleys potentially allow measurements of fluvial bedrock incision in mountainous relief. Using digital elevation models, topographic maps, and field reconnaissance, we identified and characterized 30 tributary hanging valleys incised by gorges near their confluence with trunk streams in the Romanche watershed, French Western Alps. Longitudinal profiles of these tributaries are all convex and have abrupt knickpoints at the upper limit of oversteepened gorge reaches. We reconstructed initial glacial profiles from glacially polished bedrock knobs surrounding the gorges in order to quantify the amount of fluvial incision and knickpoint retreat. From morphometric analyses, we find that mean channel gradients and widths, as well as knickpoint retreat rates, display a drainage area dependence modulated by bedrock lithology. However, there appears to be no relation between horizontal retreat and vertical downwearing of knickpoints. Assuming a postglacial origin of these gorges, our results imply high postglacial fluvial incision (0.5-15 mm yr-1) and knickpoint retreat (1-200 mm yr-1) rates that are, however, consistent with previous estimates. Numerical modeling was used to test the capacity of different fluvial incision models to predict the inferred evolution of the gorges. Results from simple end-member models suggest transport-limited behavior of the bedrock gorges. A more sophisticated model including dynamic width adjustment and sediment-dependent incision rates predicts present-day channel geometry only if a significant supply of sediment from the gorge sidewalls (˜10 mm yr-1) is triggered by gorge deepening, combined with pronounced inhibition of bedrock incision by sediment transport and deposition.

  12. Corrections to the knife-edge based reconstruction scheme of tightly focused light beams.

    PubMed

    Huber, C; Orlov, S; Banzer, P; Leuchs, G

    2013-10-21

    The knife-edge method is an established technique for profiling light beams. It was shown, that this technique even works for tightly focused beams, if the material and geometry of the probing knife-edges are chosen carefully. Furthermore, it was also reported recently that this method fails, when the knife-edges are made from pure materials. The artifacts introduced in the reconstructed beam shape and position depend strongly on the edge and input beam parameters, because the knife-edge is excited by the incoming beam. Here we show, that the actual beam shape and spot size of tightly focused beams can still be derived from knife-edge measurements for pure edge materials and different edge thicknesses by adapting the analysis method of the experimental data taking into account the interaction of the beam with the edge. PMID:24150349

  13. PRESAGE 3D dosimetry accurately measures Gamma Knife output factors

    NASA Astrophysics Data System (ADS)

    Klawikowski, Slade J.; Yang, James N.; Adamovics, John; Ibbott, Geoffrey S.

    2014-12-01

    Small-field output factor measurements are traditionally very difficult because of steep dose gradients, loss of lateral electronic equilibrium, and dose volume averaging in finitely sized detectors. Three-dimensional (3D) dosimetry is ideal for measuring small output factors and avoids many of these potential challenges of point and 2D detectors. PRESAGE 3D polymer dosimeters were used to measure the output factors for the 4 mm and 8 mm collimators of the Leksell Perfexion Gamma Knife radiosurgery treatment system. Discrepancies between the planned and measured distance between shot centers were also investigated. A Gamma Knife head frame was mounted onto an anthropomorphic head phantom. Special inserts were machined to hold 60 mm diameter, 70 mm tall cylindrical PRESAGE dosimeters. The phantom was irradiated with one 16 mm shot and either one 4 mm or one 8 mm shot, to a prescribed dose of either 3 Gy or 4 Gy to the 50% isodose line. The two shots were spaced between 30 mm and 60 mm apart and aligned along the central axis of the cylinder. The Presage dosimeters were measured using the DMOS-RPC optical CT scanning system. Five independent 4 mm output factor measurements fell within 2% of the manufacturer’s Monte Carlo simulation-derived nominal value, as did two independent 8 mm output factor measurements. The measured distances between shot centers varied by ±0.8 mm with respect to the planned shot displacements. On the basis of these results, we conclude that PRESAGE dosimetry is excellently suited to quantify the difficult-to-measure Gamma Knife output factors.

  14. Minimal incision posterior approach levator plication for aponeurotic ptosis

    PubMed Central

    Ng, D S; Chan, E; Ko, S T

    2015-01-01

    Purpose To assess the efficacy and predictability of a minimal incision posterior approach levator plication technique for correction of involutional ptosis. Method Retrospective chart review of patients with involutional aponeurotic ptosis underwent minimal incision posterior approach levator plication technique between August 2013 and June 2014 by a single surgeon. The upper lid was double everted, and the conjunctiva and Muller's muscle layers were incised vertically until the levator aponeurosis could be identified. The incision(s) was similar to performing incision and curettage of chalazion, except that the site was above the tarsal plate and extended towards the fornix. Then insertion of aponeurosis was dissected away from the anterior tarsal surface, and the more superiorly located levator was plicated on it with double arm suture(s). No tissue was excised in this procedure. Surgical success was defined as a postoperative margin reflex distance (MRD)>2 mm and<4.5 mm, interlid height<1 mm and satisfactory contour. Results Forty-four lids of 27 patients were included. Preoperative mean MRD was 0.48 +/− 0.56 mm. Severe ptosis of MRD<1 mm was present in 34/44 patients (77.3%). The postoperative mean MRD was 2.49 +/− 0.53 mm, and mean improvement was 2.02 +/− 0.61 mm, which was statistically significant (P<0.001). The overall success rate was 38/44 (86.4%). Conclusions Minimal incision posterior approach to levator plication was effective for the correction of aponeurotic ptosis with moderate to good levator function. PMID:25613849

  15. MCNP-based computational model for the Leksell Gamma Knife

    SciTech Connect

    Trnka, Jiri; Novotny, Josef Jr.; Kluson, Jaroslav

    2007-01-15

    We have focused on the usage of MCNP code for calculation of Gamma Knife radiation field parameters with a homogenous polystyrene phantom. We have investigated several parameters of the Leksell Gamma Knife radiation field and compared the results with other studies based on EGS4 and PENELOPE code as well as the Leksell Gamma Knife treatment planning system Leksell GammaPlan (LGP). The current model describes all 201 radiation beams together and simulates all the sources in the same time. Within each beam, it considers the technical construction of the source, the source holder, collimator system, the spherical phantom, and surrounding material. We have calculated output factors for various sizes of scoring volumes, relative dose distributions along basic planes including linear dose profiles, integral doses in various volumes, and differential dose volume histograms. All the parameters have been calculated for each collimator size and for the isocentric configuration of the phantom. We have found the calculated output factors to be in agreement with other authors' works except the case of 4 mm collimator size, where averaging over the scoring volume and statistical uncertainties strongly influences the calculated results. In general, all the results are dependent on the choice of the scoring volume. The calculated linear dose profiles and relative dose distributions also match independent studies and the Leksell GammaPlan, but care must be taken about the fluctuations within the plateau, which can influence the normalization, and accuracy in determining the isocenter position, which is important for comparing different dose profiles. The calculated differential dose volume histograms and integral doses have been compared with data provided by the Leksell GammaPlan. The dose volume histograms are in good agreement as well as integral doses calculated in small calculation matrix volumes. However, deviations in integral doses up to 50% can be observed for large

  16. MCNP-based computational model for the Leksell gamma knife.

    PubMed

    Trnka, Jiri; Novotny, Josef; Kluson, Jaroslav

    2007-01-01

    We have focused on the usage of MCNP code for calculation of Gamma Knife radiation field parameters with a homogenous polystyrene phantom. We have investigated several parameters of the Leksell Gamma Knife radiation field and compared the results with other studies based on EGS4 and PENELOPE code as well as the Leksell Gamma Knife treatment planning system Leksell GammaPlan (LGP). The current model describes all 201 radiation beams together and simulates all the sources in the same time. Within each beam, it considers the technical construction of the source, the source holder, collimator system, the spherical phantom, and surrounding material. We have calculated output factors for various sizes of scoring volumes, relative dose distributions along basic planes including linear dose profiles, integral doses in various volumes, and differential dose volume histograms. All the parameters have been calculated for each collimator size and for the isocentric configuration of the phantom. We have found the calculated output factors to be in agreement with other authors' works except the case of 4 mm collimator size, where averaging over the scoring volume and statistical uncertainties strongly influences the calculated results. In general, all the results are dependent on the choice of the scoring volume. The calculated linear dose profiles and relative dose distributions also match independent studies and the Leksell GammaPlan, but care must be taken about the fluctuations within the plateau, which can influence the normalization, and accuracy in determining the isocenter position, which is important for comparing different dose profiles. The calculated differential dose volume histograms and integral doses have been compared with data provided by the Leksell GammaPlan. The dose volume histograms are in good agreement as well as integral doses calculated in small calculation matrix volumes. However, deviations in integral doses up to 50% can be observed for large

  17. Gamma knife for obsessive compulsive disorder: can it be detrimental?

    PubMed

    Tripathi, Manjul; Mukherjee, Kanchan; Chhabra, Rajesh; Radotra, Ishan; Singh, Apinder P; Radotra, Bishan

    2014-01-01

    Functional neurological disorders (FND) have been a challenge to treat both for neurologists and neurosurgeons. Various ablative as well as non-ablative techniques have been used to treat these disorders. Gamma knife radiosurgery (GKRS) is also being practised to treat refractory obsessive- compulsive disorder (OCD). The subsequent complications of GKRS reported have been variable, with headache being the most common. We discuss here a rare complication of 'late onset radiation necrosis in bilateral caudate nuclei' in a patient after receiving GKRS three years back. This case highlights the need to be more cautious before administering ablative procedures in patients suffering with functional disorders. PMID:25050687

  18. Unusual clinical case: extraluminal manifestation of a tapeworm from the eviscerated midline incision in a post-surgery patient.

    PubMed

    Dural, Ahmet Cem; Celik, Muhammet Ferhat; Temizgonul, Baha; Unsal, Mustafa Gokhan; Akarsu, Cevher; Gonenc, Murat; Kalayci, Mustafa Uygar; Alis, Halil

    2015-04-01

    Taenia saginata infestation is one of the most common cestode infestations in humans, that may cause gastrointestinal tract related complications as a result of obstruction, perforation or anastomotic leakage. A 55-year-old male patient who was receiving palliative chemotherapy for stage IV gastric cancer was admitted to the emergency department for abdominal pain. A hollow viscus organ perforation was diagnosed and an emergency surgery was performed. On postoperative day 5, the patient's midline incision eviscerated and a moving taenia emerged, with abundant particulated fluid from the incision line. The patient was admitted for abdominal surgery due to suspected bowel perforation. During the abdominal exploration, a relaxed purse stitch of the feeding tube was observed and no other bowel perforations were seen. The patient underwent two planned surgery for abdominal cavity lavage after the removal of cestode. Unfortunately, the patient died sixteen days after his admission to the intensive care unit. This is the first case describing an extraluminal manifestation of a tapeworm in a midline incision from evisceration without intestinal perforation. PMID:25881535

  19. Lateral Erosion Encourages Vertical Incision in a Bimodal Alluvial River

    NASA Astrophysics Data System (ADS)

    Gran, K. B.

    2015-12-01

    Sand can have a strong impact on gravel transport, increasing gravel transport rates by orders of magnitude as sand content increases. Recent experimental work by others indicates that adding sand to an armored bed can even cause armor to break-up and mobilize. These two elements together help explain observations from a bimodal sand and gravel-bedded river, where lateral migration into sand-rich alluvium breaks up the armor layer, encouraging further incision into the bed. Detailed bedload measurements were coupled with surface and subsurface grain size analyses and cross-sectional surveys in a seasonally-incised channel carved into the upper alluvial fan of the Pasig-Potrero River at Mount Pinatubo, Philippines. Pinatubo erupted in 1991, filling valleys draining the flanks of the volcano with primarily sand-sized pyroclastic flow debris. Twenty years after the eruption, sand-rich sediment inputs are strongly seasonal, with most sediment input to the channel during the rainy season. During the dry season, flow condenses from a wide braided planform to a single-thread channel in most of the upper basin, extending several km onto the alluvial fan. This change in planform creates similar unit discharge ranges in summer and winter. Lower sediment loads in the dry season drive vertical incision until the bed is sufficiently armored. Incision proceeds downstream in a wave, with increasing sediment transport rates and decreasing grain size with distance downstream, eventually reaching a gravel-sand transition and return to a braided planform. Incision depths in the gravel-bedded section exceeded 3 meters in parts of a 4 km-long study reach, a depth too great to be explained by predictions from simple winnowing during incision. Instead, lateral migration into sand-rich alluvium provides sufficient fine sediment to break up the armor surface, allowing incision to start anew and increasing the total depth of the seasonally-incised valley. Lateral migration is recorded in a

  20. Episodic incision of the Colorado River in Glen Canyon, Utah

    USGS Publications Warehouse

    Garvin, C.D.; Hanks, T.C.; Finkel, R.C.; Heimsath, A.M.

    2005-01-01

    Incision rates of the Colorado River are integral to understanding the development of the Colorado Plateau. Here we calculate episodic incision rates of the Colorado River based on absolute ages of two levels of Quaternary deposits adjacent to Glen Canyon, Utah, along the north flank of Navajo Mountain. Minimum surface ages are determined by a combination of cosmogenic radionuclide surface exposure ages, uranium series and soil-development formation times. Bedrock incision rates of the Colorado River between c. 500 ka and c. 250 ka, and c. 250 ka to present are c. 0??4 m ka-1 and c. 0??7 m ka-1, respectively. These rates are more than double the rates reported in the Grand Canyon, suggesting that the Colorado River above Lees Ferry is out of equilibrium with the lower section of the river. We also determine incision rates of two tributaries to the Colorado River. Oak Creek and Bridge Creek flow off Navajo Mountain into Glen Canyon from the southeast. Oak Creek and Bridge Creek both have incision rates of c. 0??6 m ka-1 over the past c. 100 ka at points about 9 km away from the main stem of the Colorado River. Copyright ?? 2005 John Wiley & Sons, Ltd.

  1. H incision--method of choice for radical neck dissection.

    PubMed

    Kambic, V; Sĭrca, A

    1977-05-01

    To prevent skin necrosis, fistula formation and rupture of the carotid arteries after RND, vascularization of the skin of the neck has been considered. The neck vessels (in cadavers) were injected with coloured media and specimens of the skin were cleared (Spalteholz method). The arteries supplying the skin of the neck followed in general an obviously longitudinal course: one group of cutaneous arteries descending from the branches of the external carotid; another group ascending from the branches of the subclavian artery. The upper and lower groups of arteries joined approximately in the middle of the neck. The density of cutaneous arteries in the neck was much poorer than in the facial skin. On the basis of these anatomic data, an incision for RND has been proposed in the form of an H or three-quarter H, in which the transverse line of the incision follows the least vascularized skin region of the neck, without interrupting the great skin vessels. Incisions in the form of a Z or a double Y, OR McFee's incision, do not fulfil this requirement. The authors also report the results of wound healing after RND in 184 patients who were operated in the period fron 1968 to 1975 at the E. N. T. clinic of Ljubljana, where the H incision or one of its modifications was used. PMID:864314

  2. Mechanism of rotational relaxation.

    NASA Technical Reports Server (NTRS)

    Polanyi, J. C.; Woodall, K. B.

    1972-01-01

    A model is presented which describes the characteristic pattern of relaxation of a nonthermal rotational distribution of hydrogen halide, peaked initially at high rotational quantum number J, to a thermal distribution without generating a peak at intermediate J. A method for correcting infrared chemiluminiscence data for modest rotational relaxation is also suggested.

  3. TEACHING NEUROMUSCULAR RELAXATION.

    ERIC Educational Resources Information Center

    NORRIS, JEANNE E.; STEINHAUS, ARTHUR H.

    THIS STUDY ATTEMPTED TO FIND OUT WHETHER (1) THE METHODS FOR ATTAINING NEUROMUSCULAR RELAXATION THAT HAVE PROVED FRUITFUL IN THE ONE-TO-ONE RELATIONSHIP OF THE CLINIC CAN BE SUCCESSFULLY ADAPTED TO THE TEACHER-CLASS RELATIONSHIP OF THE CLASSROOM AND GYMNASIUM, AND (2) NEUROMUSCULAR RELAXATION CAN BE TAUGHT SUCCESSFULLY BY AN APPROPRIATELY TRAINED…

  4. Dosimetrical evaluation of Leksell Gamma Knife 4C radiosurgery unit

    NASA Astrophysics Data System (ADS)

    Sajeev, Thomas; Mustafa, Mohamed M.; Supe, Sanjay S.

    2011-01-01

    A number of experiments was performed using standard protocols, in order to evaluate the dosimetric accuracy of Leksell Gamma Knife 4C unit. Verification of the beam alignment has been performed for all collimators using solid plastic head phantom and Gafchromic™ type MD-55 films. The study showed a good agreement of Leksell Gammaplan calculated dose profiles with experimentally determined profiles in all three axes. Isocentric accuracy is verified using a specially machined cylindrical aluminium film holder tool made with very narrow geometric tolerances aligned between trunnions of 4 mm collimator. Considering all uncertainties in all three dimensions, the estimated accuracy of the unit was 0.1 mm. Dose rate at the centre point of the unit has been determined according to the IAEA, TRS-398 protocol, using Unidose-E (PTW-Freiburg, Germany) with a 0.125 cc ion chamber, over a period of 6 years. The study showed that the Leksell Gamma Knife 4C unit is excellent radiosurgical equipment with high accuracy and precision, which makes it possible to deliver larger doses of radiation, within the limits defined by national and international guidelines, applicable for stereotactic radiosurgery procedures.

  5. [Dorso-ventral continuous irrigation using the Incise Pouch].

    PubMed

    Dittrich, K; Kriwanek, S; Armbruster, C

    1993-01-01

    Dorso-ventral lavage procedures in the treatment of abdominal sepsis are often complicated by technical and nursing problems. With the help of the Incise Pouch, which consists of an adhesive foil with a plastic bag around it, we have succeeded in solving the main problems of the dorso-ventral lavage procedure. (1) All the lavage solution is collected in the bag and drawn into a vacuum pump. The suction drains are placed directly in the bag. This enables us to measure the lavage solution exactly. (2) There is no leakage of liquid into the bed, so that the patient remains dry. (3) The danger of intestinal fistulas or intraabdominal bleeding caused by suction drains is eliminated (by putting them into the bag of the Incise Pouch). If reexploration of the abdominal cavity ("on demand" or planned) is done, the Incise Pouch remains in position. This method makes early diagnosis and treatment of postoperative complications possible. PMID:8326812

  6. Management of insertional Achilles tendinopathy through a Cincinnati incision

    PubMed Central

    Carmont, Michael R; Maffulli, Nicola

    2007-01-01

    Background About 10% of patients not responding to 3–6 months of conservative management for insertional Achilles tendinopathy undergo surgery. Traditionally, surgery of the Achilles tendon is performed through longitudinal extensile incisions. Such surgery is prone to the complications of wound healing, wound breakdown and iatrogenic nerve injury. Methods We describe our current method of exposure of the Achilles tendon insertion and debridement of the peritendinous and tendon tissue with osteotomy of the calcaneum through a transverse skin incision at the level of the Achilles insertion. Results This method has been used since 2002 on over 40 patients for exposure of the Achilles tendon insertion and the distal Achilles tendon. Conclusion The Cincinnati incision allows adequate exposure, has minimal risk of symptomatic iatrogenic nerve injury, and has minimal problems related to the scar. PMID:17697370

  7. The problem of insufficient incisal display: a case presentation.

    PubMed

    Castillo, Rodrigo

    2010-01-01

    Enhancement of facial beauty is one of the primary elective goals of patients seeking dental care. Frequently, improvements in natural beauty can be expected to follow restoration of ideal relationships between the denture and the facial soft tissues. A very important feature in a youthful appearance is the incisal tooth display; the amount of maxillary incisal exposure gradually decreases with age, accompanied by a gradual increase in mandibular incisal exposure. However, this problem could be present in young people where the effects of age should not be apparent yet. There are some other factors that could accelerate this process. The present case illustrates the improvement and rejuvenation of an unesthetic young smile through restorative treatment. PMID:20589259

  8. Force modeling for incision surgery into tissue with haptic application

    NASA Astrophysics Data System (ADS)

    Kim, Pyunghwa; Kim, Soomin; Choi, Seung-Hyun; Oh, Jong-Seok; Choi, Seung-Bok

    2015-04-01

    This paper presents a novel force modeling for an incision surgery into tissue and its haptic application for a surgeon. During the robot-assisted incision surgery, it is highly urgent to develop the haptic system for realizing sense of touch in the surgical area because surgeons cannot sense sensations. To achieve this goal, the force modeling related to reaction force of biological tissue is proposed in the perspective on energy. The force model describes reaction force focused on the elastic feature of tissue during the incision surgery. Furthermore, the force is realized using calculated information from the model by haptic device using magnetorheological fluid (MRF). The performance of realized force that is controlled by PID controller with open loop control is evaluated.

  9. Endoscopic treatment for pancreatic diseases: Needle-knife-guided cannulation via the minor papilla

    PubMed Central

    Wang, Wei; Gong, Biao; Jiang, Wei-Song; Liu, Lei; Bielike, Kouken; Xv, Bin; Wu, Yun-Lin

    2015-01-01

    AIM: To determine the efficacy and safety of meticulous cannulation by needle-knife. METHODS: Three needle-knife procedures were used to facilitate cannulation in cases when standard cannulation techniques failed. A total of 104 cannulations via the minor papilla attempted in 74 patients at our center between January 2008 and June 2014 were retrospectively reviewed. RESULTS: Standard methods were successful in 79 cannulations. Of the 25 cannulations that could not be performed by standard methods, 19 were performed by needle-knife, while 17 (89.5%) were successful. Needle-knife use improved the success rate of cannulation [76.0%, 79/104 vs 92.3%, (79 + 17)/104; P = 0.001]. When the 6 cases not appropriate for needle-knife cannulation were excluded, the success rate was improved further (80.6%, 79/98 vs 98.0%, 96/98; P = 0.000). There were no significant differences in the rates of post-endoscopic retrograde cholangiopancreatography adverse events between the group using standard methods alone and the group using needle-knife after failure of standard methods (4.7% vs 10.5%, P = 0.301). CONCLUSION: The needle-knife procedure may be an alternative method for improving the success rate of cannulation via the minor papilla, particularly when standard cannulation has failed. PMID:26019460

  10. Very long-term incision dynamics of big rivers

    NASA Astrophysics Data System (ADS)

    Grimaud, Jean-Louis; Chardon, Dominique; Beauvais, Anicet

    2014-11-01

    Constraining large-scale incision dynamics of shield and post-rift margin domains is key to understanding the sediment routing system over the overwhelming part of the continental surface. Based on dated and regionally correlated incision markers from West Africa, we reconstruct for the first time the entire paleo-long profiles of big rivers such as the Niger at ca. 24, 11 and 6 Ma, as well as the Eocene topography those rivers have dissected. The results provide boundary conditions and calibration for surface process models and paleodrainage dynamics. Though spatially and temporally variable, incision remained mostly below 10 m/my with a mean around 5 m/my. The spatial stability of both the river outlets and divides imposed maintenance or increasing concavity of the river long profiles through time, resulting from spatially contrasted adjustment of river segments bounded by recurrent lithogenic knickzones that persisted since 24 Ma. Drainages evolved preferentially by very slow slope decrease or uniform incision in between the stationary knickzones of evolving amplitude, with apparently no relation to base level change. Therefore, knickzone height or position may not simply reflect the transient response of big rivers to base level fall as predicted by stream-power incision river models. This may also challenge uplift histories of deep continental interiors retrieved from river long profiles inversion relying on such models. Very slow incision allowed amplification of the Hoggar hot spot swell and flexural uplift of the continental margin to be recorded by river long profiles, emphasizing the potential of big non-orogenic rivers as gauges of dynamic topography.

  11. [Evolution and Development Trend of Lung Cancer Surgical Incision].

    PubMed

    Xie, Dong; Chen, Chang; Jiang, Gening

    2016-06-20

    Minimally invasive, safe and tumor-free are the main principles of the choice of surgical incision in lung cancer surgery. In recent years, with the advances in minimally invasive techniques, single-port video assisted thoracic surgery (VATS), robot-assisted thoracoscopic (RATS), suboxiphoid single-port VATS, simultaneous bilateral VATS pulmonary resection, are emerging approaches, single-port VATS has become one of the most exciting new developments in minimally invasive thoracic surgery in recent years. This paper reviews the evolution and trends of surgical incision in lung cancer surgery. PMID:27335293

  12. A new glove port for single incision procedure

    PubMed Central

    Ko, Yoon Song; Yoon, Sam Youl; Han, Hyung Joon; Yim, Tae Wan

    2015-01-01

    Single-incision laparoscopic surgery has gained increasing attention due to its potential to improve the benefits of laparoscopic surgery. However, inconvenience remains for inexperienced surgeons during surgery when instruments conflict with each other, and a glove port is used hesitantly for such diagnosis related groups (DRG) because of its high cost. Authors made a new glove port by an odd surgical gloves and one wound protectors. This glove port is ease to make besides being convenient to us, and inexpensive. This new glove port has the benefit of easy utilization and cost effectiveness for surgeons performing single-incision laparoscopic surgery. PMID:26576410

  13. Development of knife-edge field emission cathodes on (110) silicon wafers

    NASA Astrophysics Data System (ADS)

    Lee, Bo; Barasch, E. F.; Mazumdar, T.; McIntyre, P. M.; Pang, Y.; Trost, H.-J.

    1993-04-01

    Knife-edge field emission cathodes have been fabricated on (110) silicon wafers. The emitter structure consists of an array of razor shaped silicon knife edges standing up on silicon substrates. The radii of the sharp edges seen with SEM are less than 250 Å; the height of the knife edges is 5 to 8 μm; and the gate-emitter spacing is ˜0.1 μm. Because of the very small gate-emitter spacing and the large height/width ratio of the emitter, the structure resembles an optimized emitter geometry concluded from our study. The fabrication process and results are presented.

  14. Application of a cervical low incision in the functional neck dissection of thyroid papillary carcinoma

    PubMed Central

    XU, JIAJIE; CHEN, CHAO; ZHENG, CHUANMING; WANG, KEJING; SHANG, JINBIAO; FANG, XIANHUA; GE, MINGHUA; TAN, ZHUO

    2016-01-01

    The present study aimed to discuss the advantage of the application of a cervical low incision for functional neck dissection in patients with thyroid papillary carcinoma. The study was a retrospective analysis of 87 thyroid papillary carcinoma patients; cervical low incision in the functional neck dissection was applied for 47 cases and the classic ‘L’ incision was applied for 40 cases. The different integrity, surgical time, blood loss and the aesthetic property of the incision were compared between the cervical low incision and the classic ‘L’ incision for lateral neck dissection of thyroid cancer. The postoperative pathological diagnosis was that the average total amount and the region II lymph nodes of the unilateral neck dissection were 33 and 10 for the cervical low incision group, and 32 and 11 for the classic ‘L’ incision group, respectively (P>0.05). The average unilateral neck dissection times were 87 and 58 min for the cervical low incision group and the classic ‘L’ incision group, respectively (P<0.05). The blood loss of the cervical low incision group was 67 ml, while the loss for the classic ‘L’ incision group was 61 ml (P>0.05). The postoperative incision of the cervical low incision group was smaller and more concealing. Additionally, the cosmetic deformities were milder for an inconspicuous cervical scar, and the sensation was improved for the patients in comparison with the classic ‘L’ incision group. These results suggest that the application of cervical low incision for functional neck dissection in thyroid papillary carcinoma patients aids in reducing postoperative complications, without increasing recurrence rates. Therefore, the classic ‘L’ incision can be replaced by the cervical low incision. PMID:27073645

  15. Imaging and investigating the effects of incision angle of clear corneal cataract surgery with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Rao, Bin; Zhang, Jun; Taban, Mehran; McDonnell, Peter J.; Chen, Zhongping

    2003-12-01

    Effects of incision angle in construction of clear corneal cataract incision are studied with optical coherence tomography (OCT). A stable incision angle range is found to be existent for single-planed, clear corneal cataract incisions. When well pressurized, incision angles within this stable range result in well-apposed incision edges that resist gapping while incision angles falling outside this range have a larger tendency for wound leakage. It is also shown that a two-planed incision can effectively expand the stable range. For incision angles outside the stable range, the farther the incision angle is away from stable range, the larger the gap between incision wound edges when well pressurized. These findings emphasize the significance of incision construction to the self-sealing property of clear corneal cataract incisions. Finally, we demonstrate that OCT could be an effective modality for imaging and monitoring corneal surgery.

  16. INVESTIGATION OF WASTE GLASS POURING PROCESS OVER A KNIFE EDGE

    SciTech Connect

    M.A. Ebadian, Ph.D.

    1999-01-01

    Vitrification is the process of capturing radioactive waste in glass. The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF) is one of the facilities using the vitrification technology to treat and immobilize radioactive waste. The objective of the project is to investigate the pouring behavior of molten glass over a pour spout knife edge. Experiments are run using simulant glass containing the same chemical formulation as the radioactive sludge glass, but without radioactive contaminants. The purpose of these tests is to obtain actual glass data that, when combined with previous cold data from other fluids, will provide an overall understanding of the physics of liquids flowing over a pour spout and knife edge, A specific objective is to verify computational fluid dynamics (CFD) models with a range of liquid data with particular emphasis on glass so as to provide confidence in use of these CFD models for designing a new improved pour spout for the DWPF melter. The work to be performed at FIU-HCET includes assembling the melting and pouring system that mimics the DWPF melter and determining the key parameters that may influence wicking. Information from the FIU-HCET melter tests will lead to better operating guidelines for the DWPF melter so as to avoid wicking. During FY98, a bench-scale melter complete with pour spout and a knife edge was designed and assembled at FIU-HCET. Initially, the system was tested with glycerine. Subsequently, glass provided by SRS was used for experimentation. Flow visualization tests were performed with the melter in FY98 to investigate the pouring behavior of molten glass over a pour spout model simulating a DWPF pour spout of the original design. Simulant glass containing the same chemical formulation as sludge glass but without radioactive contaminants was used in the tests. All the tasks and milestones mentioned in the PTP for the project were accomplished. The project completed its second year, and this document

  17. Stereotactic radiosurgery using the gamma knife for acoustic neuromas

    SciTech Connect

    Foote, R.L.; Coffey, R.J.; Swanson, J.W.

    1995-07-15

    The purpose of this investigation was to assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas. Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompasses within the prescribed isodose line varied from 266 to 8,667 mm{sup 3} (median: 3,135 mm{sup 3}). Tumors {<=} 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients < age 65 years, (b) dose to the tumor margin, (c) maximum tumor diameter {>=} 21 mm, (d) use of the 18 mm collimator, and (e) use of > five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% {plus_minus} 17.3, respectively. Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients. 30 refs., 5 tabs.

  18. Single-incision laparoscopic surgery for biliary tract disease

    PubMed Central

    Chuang, Shu-Hung; Lin, Chih-Sheng

    2016-01-01

    Single-incision laparoscopic surgery (SILS), or laparoendoscopic single-site surgery, has been employed in various fields to minimize traumatic effects over the last two decades. Single-incision laparoscopic cholecystectomy (SILC) has been the most frequently studied SILS to date. Hundreds of studies on SILC have failed to present conclusive results. Most randomized controlled trials (RCTs) have been small in scale and have been conducted under ideal operative conditions. The role of SILC in complicated scenarios remains uncertain. As common bile duct exploration (CBDE) methods have been used for more than one hundred years, laparoscopic CBDE (LCBDE) has emerged as an effective, demanding, and infrequent technique employed during the laparoscopic era. Likewise, laparoscopic biliary-enteric anastomosis is difficult to carry out, with only a few studies have been published on the approach. The application of SILS to CBDE and biliary-enteric anastomosis is extremely rare, and such innovative procedures are only carried out by a number of specialized groups across the globe. Herein we present a thorough and detailed analysis of SILC in terms of operative techniques, training and learning curves, safety and efficacy levels, recovery trends, and costs by reviewing RCTs conducted over the past three years and two recently updated meta-analyses. All existing literature on single-incision LCBDE and single-incision laparoscopic hepaticojejunostomy has been reviewed to describe these two demanding techniques. PMID:26811621

  19. Single-incision pediatric endosurgery in newborns and infants

    PubMed Central

    Kozlov, Yury; Novozhilov, Vladimir; Baradieva, Polina; Krasnov, Pavel; Kovalkov, Konstantin; Muensterer, Oliver J

    2015-01-01

    This study focuses on the successful application of single-incision pediatric endosurgery in the treatment of congenital anomalies and acquired diseases in neonates and infants. The purpose of this scientific review consists in highlighting the spectrum, indications, applicability, and effectiveness of single-port endosurgery in children during the first 3 postnatal months. PMID:26566478

  20. Learning micro incision surgery without the learning curve

    PubMed Central

    Navin, Shoba; Parikh, Rajul

    2008-01-01

    We describe a method of learning micro incision cataract surgery painlessly with the minimum of learning curves. A large-bore or standard anterior chamber maintainer (ACM) facilitates learning without change of machine or preferred surgical technique. Experience with the use of an ACM during phacoemulsification is desirable. PMID:18292624

  1. Phenomenon of mucous retention in the incisive canal.

    PubMed

    Keith, D A

    1979-11-01

    Mucous glands are rarely found in the anterior palate but may be observed in the incisive canal. A case history is presented of a lesion that resembled a nasopalatine cyst both clinically and radiographically but which was in fact an intra-bony extravasation phenomenon. PMID:290778

  2. Z skin incision in reduced-port surgery for colorectal cancer

    PubMed Central

    FUJINO, SHIKI; MIYOSHI, NORIKATSU; OHUE, MASAYUKI; NOURA, SHINGO; FUJIWARA, YOSHIYUKI; HIGASHIYAMA, MASAHIKO; YANO, MASAHIKO

    2016-01-01

    Laparoscopic surgery for colorectal cancer (CRC) has recently gained in popularity due to the fewer trocars and shorter incision, leading to reduced wound pain and improved cosmetic outcome. In July, 2013, reduced-port surgery (RPS) was introduced and has been performed thereafter in our hospital. An umbilical incision is used for a main port in RPS, through which the specimen is removed and the anastomosis is performed. In order to make the incision shorter, we introduced the Z skin incision in RPS. In this study, we aimed to discuss this method and evaluate the short-term outcome. Among CRC patients undergoing RPS, Z skin incision (n=14) was compared to conventional skin incision (n=15). The clinical and surgical factors were evaluated and there were no significant differences in terms of gender, age, body mass index, tumor site, procedure, operative time, blood loss or complications between the two groups. The median incision length at the umbilicus was significantly shorter in the Z incision group (P=0.004). Particularly in functional end-to-end anastomosis, the median incision length was 2.5 cm in the Z skin incision group and 4.0 cm in the conventional incision group (P=0.018). In conclusion, Z skin incision is a useful technique for achieving an effective length of skin incision in RPS for CRC. PMID:27073675

  3. Cosmetic selection of skin incision for resection of choledochal cyst in young female patients

    PubMed Central

    Choi, Jong-Woo; Ha, Tae-Yong; Song, Gi-Won; Jung, Dong-Hwan

    2016-01-01

    Backgrounds/Aims Open surgery for choledochal cyst has a disadvantage of skin incision scar from operative wound, which can be a definite disadvantage especially in young female patients. This study focused on the cosmetic aspect of skin incision for resection of choledochal cyst in young female patients. Methods During a 2-year study period, 11 adult female patients aged less than 40 years underwent primary resection of choledochal cyst by a single surgeon. The cosmetic effect of two types of skin incision was evaluated. Results The patients underwent mini-laparotomy through either a right subcostal incision (n=8) or an upper midline incision (n=3). The mean length of skin incision was 10 cm for right subcostal incisions and 9 cm for upper midline incisions. It took approximately 1 hour to repair the operative wound meticulously in both groups. At the 6 month to 1 year follow-up, a slight bulge on the skin scar was observed in 3 (37.5%) patients of the right subcostal incision group and 1 (33.3%) patient of the upper midline incision group. Conclusions The results of this preliminary study support the claim that cosmetic effect of the upper midline incision for CCD surgery appears to be non-inferior to that of the right subcostal incision if the incision is placed accurately and repaired very meticulously. PMID:27621750

  4. Late Quaternary rates of stream incision in Northeast Peloponnese, Greece

    NASA Astrophysics Data System (ADS)

    Karymbalis, Efthimios; Papanastassiou, Dimitrios; Gaki-Papanastassiou, Kalliopi; Ferentinou, Maria; Chalkias, Christos

    2016-09-01

    This study focuses on defining rates of fluvial incision for the last 580±5 kyr along valley systems of eight streams that drain the eastern part of the northern Peloponnese. The streams are developed on the uplifted block of the offshore-running Xylokastro normal fault, one of the main faults bounding the southern edge of the Gulf of Corinth half-graben, and have incised a set of ten uplifted marine terraces having an amphitheatric shape. These terraces range in age from 60±5 kyr to 580±5 kyr and have been mapped in detail and correlated with late Pleistocene oxygen-isotope stages of high sea-level stands by previous studies. The terraces were used in this paper as reference surfaces in order to define fluvial incision rates at the lower reaches of the studied streams. To evaluate incision rates, thirty-three topographic valley cross-sections were drawn using fieldwork measurements as well as using a highly accurate (2×2 cell size) Digital Elevation Model (DEM) at specific locations where streams cut down the inner edges of the marine terraces. For each cross-section the ratio of valley floor width to valley height (Vf) and long-term mean stream incision rates were estimated for the last 580±5 kyr, while rock uplift rates were estimated for the last 330±5 kyr. The geomorphic evolution of the valleys on the uplifted block of the Xylokastro fault has been mainly driven by the lithology of the bedrock, sea level fluctuations during the late Quaternary, and incision of the channels due to the tectonic uplift. Stream incision rates range from 0.10±0.1 mm/yr for the last 123±7 kyr to 1.14±0.1 mm/yr for the last 310±5 kyr and are gradually greater from east to west depending on the distance from the trace of the fault. Downcutting rates are comparable with the rock uplift rates, which range from 0.4±0.02 mm/yr to 1.49±0.12 mm/yr, over the last 330±5 kyr.

  5. Late Quaternary rates of stream incision in Northeast Peloponnese, Greece

    NASA Astrophysics Data System (ADS)

    Karymbalis, Efthimios; Papanastassiou, Dimitrios; Gaki-Papanastassiou, Kalliopi; Ferentinou, Maria; Chalkias, Christos

    2016-05-01

    This study focuses on defining rates of fluvial incision for the last 580±5 kyr along valley systems of eight streams that drain the eastern part of the northern Peloponnese. The streams are developed on the uplifted block of the offshore-running Xylokastro normal fault, one of the main faults bounding the southern edge of the Gulf of Corinth half-graben, and have incised a set of ten uplifted marine terraces having an amphitheatric shape. These terraces range in age from 60±5 kyr to 580±5 kyr and have been mapped in detail and correlated with late Pleistocene oxygen-isotope stages of high sea-level stands by previous studies. The terraces were used in this paper as reference surfaces in order to define fluvial incision rates at the lower reaches of the studied streams. To evaluate incision rates, thirty-three topographic valley cross-sections were drawn using fieldwork measurements as well as using a highly accurate (2×2 cell size) Digital Elevation Model (DEM) at specific locations where streams cut down the inner edges of the marine terraces. For each cross-section the ratio of valley floor width to valley height (Vf) and long-term mean stream incision rates were estimated for the last 580±5 kyr, while rock uplift rates were estimated for the last 330±5 kyr. The geomorphic evolution of the valleys on the uplifted block of the Xylokastro fault has been mainly driven by the lithology of the bedrock, sea level fluctuations during the late Quaternary, and incision of the channels due to the tectonic uplift. Stream incision rates range from 0.10±0.1 mm/yr for the last 123±7 kyr to 1.14±0.1 mm/yr for the last 310±5 kyr and are gradually greater from east to west depending on the distance from the trace of the fault. Downcutting rates are comparable with the rock uplift rates, which range from 0.4±0.02 mm/yr to 1.49±0.12 mm/yr, over the last 330±5 kyr.

  6. A modular Geant4 model of Leksell Gamma Knife Perfexion™

    NASA Astrophysics Data System (ADS)

    Pipek, J.; Novotný, J.; Novotný, J., Jr.; Kozubíková, P.

    2014-12-01

    This work presents a Monte Carlo model of Leksell Gamma Knife Perfexion as well as the main parameters of the dose distribution in the standard phantom obtained using this model. The model is developed in the Geant4 simulation toolkit in a modular way which enables its reuse in other Perfexion studies. Large phase space files were created, containing particles that are entering the inner machine cavity after being transported through the collimation system. All 14 output factors of the machine and effective output factors for both the 4 mm (0.830 ± 0.009) and 8 mm (0.921 ± 0.004) collimators were calculated. Dose profiles along the main axes are also included for each collimator size. All results are compared to the values obtained from the treatment planning system, from experiments, and from other Monte Carlo models.

  7. Gamma knife radiosurgery for medically refractory idiopathic trigeminal neuralgia.

    PubMed

    Kang, J H; Yoon, Y S; Kang, D W; Chung, S S; Chang, J W

    2008-01-01

    Gamma knife radiosurgery (GKS) has been generally considered as a viable therapeutic option for the management of medically refractory idiopathic trigeminal neuralgia (TN). We reviewed our experience with GKS in patients with TN. Between Feb 1996 and May 2006, 77 patients with medical refractory idiopathic TN were treated using GKS. Thirty-six patients who had undergone other previous procedures, previous GKS, or had brain stem lesion, atypical symptoms, were excluded from this study. Pain improvement was achieved in 38 of the patients with TN (pain response rate 92.7%). Twenty-three patients were pain free and 15 had reduced pain. There were no serious complications. We think that GKS is an effective treatment option for patients with medical refractory idiopathic TN. PMID:18642631

  8. A modular Geant4 model of Leksell Gamma Knife Perfexion™.

    PubMed

    Pipek, J; Novotný, J; Novotný, J; Kozubíková, P

    2014-12-21

    This work presents a Monte Carlo model of Leksell Gamma Knife Perfexion as well as the main parameters of the dose distribution in the standard phantom obtained using this model. The model is developed in the Geant4 simulation toolkit in a modular way which enables its reuse in other Perfexion studies. Large phase space files were created, containing particles that are entering the inner machine cavity after being transported through the collimation system. All 14 output factors of the machine and effective output factors for both the 4 mm (0.830 ± 0.009) and 8 mm (0.921 ± 0.004) collimators were calculated. Dose profiles along the main axes are also included for each collimator size. All results are compared to the values obtained from the treatment planning system, from experiments, and from other Monte Carlo models. PMID:25415510

  9. In-line digital holography with double knife edge

    NASA Astrophysics Data System (ADS)

    Ramirez, Claudio; Iemmi, Claudio; Campos, Juan

    2015-06-01

    We study and test a new technique for in-line digital holography which avoids the formation of the conjugate images. Inline digital holography is based in a common path configuration. In this case, the hologram is produced by the interference between the reference wave front and the diffracted wave front by an almost transparent object. Twin images are obtained with obscured rings that difficult the determination of the best focusing plane. To avoid the conjugated image, the information of the magnitude and phase of the wave front are needed. In a recent work a new in-line digital holography technique was proposed. In this method the object is illuminated with a collimated wave front. A plane, close to the particles distribution is imaged onto a CCD by means of a convergent lens and at the same time, a knife edge is placed in the focal plane of the lens in order to block half of spatial frequency spectrum. In this way, by means of a numerical processing performed on the Fourier plane, it is possible to eliminate one of the components (real or conjugate) of the reconstructed images nevertheless it is observed a tiny deformation of the resulting hologram image. To compensate this effect, we propose a new configuration in which we implement the knife edge technique on both parts of the spectrum at the same time. Finally in the computer, we process the holograms to build one complete without deformation. This hologram is used to recover the wave front at different planes without the influence of the conjugate image.

  10. Thoracoscopic surgery via a single-incision subxiphoid approach is associated with less postoperative pain than single-incision transthoracic or three-incision transthoracic approaches for spontaneous pneumothorax

    PubMed Central

    Wang, Bing-Yen; Chang, Yin-Chun; Chang, Yih-Chen; Wang, Kung-Min; Lin, Ching-Hsiung; Lin, Sheng-Hao

    2016-01-01

    Background Comparison of the degree of postoperative pain associated with different thoracoscopic surgical techniques for spontaneous pneumothorax has never reported. In this study we compared perioperative outcomes and degrees of postoperative pain associated with single-incision subxiphoid thoracoscopic surgery, single-incision transthoracic thoracoscopic surgery and three-incision transthoracic thoracoscopic surgery for spontaneous pneumothorax. Methods During the period August 2013 to September 2015, fifty-seven consecutive patients with spontaneous pneumothorax were treated via single-incision subxiphoid thoracoscopic surgery, single-incision transthoracic thoracoscopic surgery or three-incision transthoracic thoracoscopic surgery. Demographic data, operative time, operative blood loss, length of hospital stay, duration of chest tube drainage, postoperative complications, and numeric pain rating scale scores were collected from the medical records for analysis. Results Among the 57 patients, 14 received single-incision subxiphoid thoracoscopic surgery, 26 underwent single-incision transthoracic surgery and 17 received three-incision thoracoscopic surgery. In all patients, surgeries were completed without the need for conversion to open surgery. Patients who underwent the single-incision subxiphoid procedure had significantly lower 1-, 8-, 24- and 32-hour postoperative pain scale scores than patients who underwent the other two procedures. The average and maximum pain scale scores during the first 24 hours were lowest in the single-incision subxiphoid group (P<0.0001). Conclusions Single-incision subxiphoid thoracoscopic surgery is associated with significantly lower postoperative pain intensity than transthoracic approaches and therefore may provide an alternative surgical technique for patients with spontaneous pneumothorax. PMID:27014474

  11. A novel technique of anesthesia induction in supine position with impaled knife in the back

    PubMed Central

    Kumar, Ajay; Saha, Kamales Kumar; Jagiasi, Bharat; Saha, Kakalee K

    2015-01-01

    Current technique of airway management for impaled knife in the back includes putting the patient in lateral position and intubation. We present here a novel technique of anesthesia induction (intubation and central line insertion) in a patient with impaled knife in the back which is simple and easily reproducible. This technique can be used for single lung ventilation using double lumen tube or bronchial blocker also if desired. PMID:25849698

  12. A novel technique of anesthesia induction in supine position with impaled knife in the back.

    PubMed

    Kumar, Ajay; Saha, Kamales Kumar; Jagiasi, Bharat; Saha, Kakalee K

    2015-01-01

    Current technique of airway management for impaled knife in the back includes putting the patient in lateral position and intubation. We present here a novel technique of anesthesia induction (intubation and central line insertion) in a patient with impaled knife in the back which is simple and easily reproducible. This technique can be used for single lung ventilation using double lumen tube or bronchial blocker also if desired. PMID:25849698

  13. Peripheral dose measurement for CyberKnife radiosurgery with upgraded linac shielding.

    PubMed

    Chuang, Cynthia F; Larson, David A; Zytkovicz, Andrea; Smith, Vernon; Petti, Paula L

    2008-04-01

    The authors investigated the peripheral dose reduction for CyberKnife radiosurgery treatments after the installation of a linac shielding upgrade. As in a previous investigation, the authors considered two treatment plans, one for a hypothetical target in the brain and another for a target in the thorax, delivered to an anthropomorphic phantom. The results of the prior investigation showed that the CyberKnife delivered significantly higher peripheral doses than comparable model C Gamma Knife or IMRT treatments. Current measurements, after the linac shielding upgrade, demonstrate that the additional shielding decreased the peripheral dose, expressed as a percentage of the delivered monitor units (MU), by a maximum of 59%. The dose reduction was greatest for cranial-caudal distances from the field edge less than 30 cm, and at these distances, the CyberKnife peripheral dose, expressed as a percentage of the delivered MU, is now comparable to that measured for the other treatment modalities in our previous investigation. For distances between 30 and 70 cm from the field edge, the additional shielding reduced the peripheral dose by between 20% and 55%. At these distances, the CyberKnife peripheral dose remains higher than doses measured in our previous study for the model C Gamma Knife and IMRT. PMID:18491544

  14. Lifting incise drapes off the skin during wound closure can cause contamination.

    PubMed

    Makki, D; Probert, N; Gedela, V; Kustos, I; Thonse, R; Banim, R

    2015-05-01

    Incise drapes adhere well to skin and reduce bacterial migration into the wound. We took skin swabs before and after the application of incise drapes during 49 hip and knee arthroplasty procedures. Contamination was detected under incise drapes in four cases (8.1%) and consisted mainly of skin flora. We conclude that it is important to clean the skin again with antiseptics if the incise drape is removed by the surgeon. PMID:26292465

  15. Modified pocket incision: a simplified technique for astigmatism control and wound closure.

    PubMed

    Kansas, P G

    1989-01-01

    Advantages of small incision cataract surgery are widely known whether performed with phacoemulsification or manual fragmentation (phacofracture). A modified pocket incision technique that allows predictable astigmatism control without reliance on expensive intraoperative keratometers is described. This technique requires less dissection than the pocket incision and is less likely to bleed. PMID:2646435

  16. Big Blocks and River Incision: A Numerical Modeling Perspective

    NASA Astrophysics Data System (ADS)

    Shobe, C. M.; Tucker, G. E.; Anderson, R. S.

    2015-12-01

    Sediment supply dynamics affect fluvial erosion in steep landscapes. Workers have explored the effects of changing sediment flux and uniform grain size on incision processes and distribution of alluvial cover. However, sediment supplied to real rivers is often highly heterogeneous in size, especially in rapidly eroding landscapes where supply processes may range from landslides to rockfall to moraine incision. We hypothesize that the pace of landscape evolution depends on the sediment size distribution supplied to rapidly eroding channels. Rivers that quickly cut steep-walled canyons may incite a negative feedback on incision by receiving an increased supply of large, immobile blocks from the canyon walls that shield significant portions of the bed from erosion. We use a 1-D numerical model that combines mass-flux continuum treatment of several grain size classes with tracking of discrete large blocks to explore fluvial response to changing grain size distribution. We compare simulations with and without a feedback between channel incision rate and the supply rate of large blocks from adjacent hillslopes. This reflects the hypothesis that slopes will be steeper and more prone to releasing large blocks when the channel at their base is eroding rapidly. Comparing model predictions with field observations shows that our models can successfully reproduce the distribution of blocks in natural channels. Results suggest that in landscapes with access to large blocks, fluvial incision may be slowed as increasing amounts of immobile material are supplied from adjacent hillslopes and canyon walls. This can act to stall knickpoint retreat in such rivers and slow the pace of landscape adjustment. The importance of channel armoring by blocks is governed by competition between two timescales: the time required for significant block cover to accumulate in the channel and the time required for blocks to abrade, fragment, or weather down to transportable sizes. Model results also

  17. Differential Uplift and Incision of the Yakima River Terraces

    NASA Astrophysics Data System (ADS)

    Bender, A. M.; Amos, C. B.; Bierman, P. R.; Rood, D. H.; Sorsby, S. J.; Kelsey, H. M.; Ladinsky, T. C.

    2014-12-01

    The Yakima fold and thrust belt comprises 12 reverse-faulted folds deforming Miocene basalts of the ~14,000 km2 Columbia River Plateau in central Washington State. Contemporary N to NE-directed shortening of ~1-2 mm/yr occurs across the belt, but the distribution of Quaternary deformation among the individual Yakima folds and faults is unclear. The Yakima River incises roughly normal to several of these structures south of Ellensburg, WA, where topography mimics structural relief and fluvial incision may be a proxy for differential rock uplift. Here, we combine LiDAR analysis, field mapping, and cosmogenic isochron burial ages of gravels above strath terraces to quantify the rate of Quaternary incision through two of these folds, Manastash and Umtanum Ridges. We mapped terraces flanking the Yakima River at five levels—individual terraces consist of mixed rock-type river gravel deposits capping basalt straths. We sampled eight terrace gravels for isochron burial dating utilizing cosmogenic 10Be and 26Al to determine terrace ages and calculate incision rates. Preliminary isochron burial ages from two sampled terraces yield mid-to-early Quaternary ages for terraces ~60 and ~15 m above the modern Yakima River (1.08 ± 0.29 Ma and 1.59 ± 0.25 Ma, respectively). Although these ages overlap within error (1s), the younger, higher terrace lies within the core of the Manastash Ridge anticline, while the lower, older deposit occurs in the intervening syncline north of Umtanum Ridge. Corresponding incision rates are < 0.10 mm/yr, and are consistent with differential uplift of the Manastash Ridge anticline, despite large age uncertainties resulting from the narrow range of relatively low 10Be concentrations for analyzed samples. We are processing additional samples to reduce burial age uncertainties, and characterize incision and uplift rates on six more strath terraces spanning heights of ~5-100 m above the active channel, distributed across the Manastash and Umtanum Ridge

  18. What can we learn from fluvial incision in high mountains?

    NASA Astrophysics Data System (ADS)

    Fuchs, Margret; Gloaguen, Richard; Krbetschek, Matthias

    2013-04-01

    High and actively deforming mountain ranges attract the attention of geoscientists as they provide natural laboratories of fast evolving process-response systems. Tectonic compressional settings, often linked to perpendicular extension, control the topographic growth and hence, erosion, transport pathways and sedimentation. High altitude differences within short horizontal distances promote material re-organisation and high rates of surface processes. Furthermore, high mountains constitute orographic barriers that affect atmospheric circulations as well as host different climate regimes similar to those of widely separated latitudinal belts. Both cause a high sensitivity of surface processes to changes in climatic conditions. However, feedbacks between climatic and tectonic forcing are complex. Additionally, the dominance of one or the other varies in space and also over time, inheriting various traces of the paleo-morphodynamic conditions to the subsequent process regimes. To unravel the forces driving the evolution of relief in active mountains, numerous studies employ the drainage network of the corresponding mountains as a proxy of landscape evolution. Especially the rates of river incision provide a powerful tool to characterize the surface response and infer causes behind it. Several parameters of river incision are available to describe the fluvial incision at individual sites (e.g. terrace incision rates), along the river course (e.g. longitudinal river profiles, Hack index) and in its perpendicular dimension (e.g. valley cross sections, valley shape ratios). But they require careful interpretation. They are sensitive to both, climatic and tectonic forcing. Therefore, the synopsis of such indices for fluvial incision is essential to evaluate the role of climatic versus tectonic forcing. Here, we use the Panj river system, the major river draining the Pamir mountains of Central Asia, as an example. The Panj experiences high altitude changes of more than 4000

  19. Dielectric relaxation time spectroscopy.

    PubMed

    Paulson, K S; Jouravleva, S; McLeod, C N

    2000-11-01

    A new mathematical method is developed to recover the permittivity relaxation spectrum of living tissue from measurements of the real and imaginary parts of the impedance. Aiming to derive information about electrical properties of living tissue without the prior selection of any impedance model, the procedure calculates the relaxation time distribution. It provides new characteristic independent parameters: time constants, their distribution, and the amplitudes of the associated dispersion. As the beta-dispersion is the most important in the area of electrical impedance spectroscopy of tissue, the paper gives an estimate of the essential frequency range to cover the whole relaxation spectrum in that area. Results are presented from both simulation and known lumped--constant element circuit. PMID:11077745

  20. Observation of Phase Objects by Using an X-ray Microscope with a Foucault Knife-Edge

    SciTech Connect

    Watanabe, N.; Sasaya, T.; Imai, Y.; Iwata, S.; Zama, K.; Aoki, S.

    2011-09-09

    An x-ray microscope with a zone plate was assembled at the synchrotron radiation source of BL3C, Photon Factory. A Foucault knife-edge was set at the back focal plate of the objective zone plate and phase retrieval was tested by scanning the knife-edge. A preliminary result shows that scanning the knife-edge during exposure was effective for phase retrieval. Phase-contrast tomography was investigated using differential projection images calculated from two Schlieren images with the oppositely oriented knife-edges. Fairly good reconstruction images of polystyrene beads and spores could be obtained.

  1. Observation of Phase Objects by Using an X-ray Microscope with a Foucault Knife-Edge

    NASA Astrophysics Data System (ADS)

    Watanabe, N.; Sasaya, T.; Imai, Y.; Iwata, S.; Zama, K.; Aoki, S.

    2011-09-01

    An x-ray microscope with a zone plate was assembled at the synchrotron radiation source of BL3C, Photon Factory. A Foucault knife-edge was set at the back focal plate of the objective zone plate and phase retrieval was tested by scanning the knife-edge. A preliminary result shows that scanning the knife-edge during exposure was effective for phase retrieval. Phase-contrast tomography was investigated using differential projection images calculated from two Schlieren images with the oppositely oriented knife-edges. Fairly good reconstruction images of polystyrene beads and spores could be obtained.

  2. The incision-excision technique in minor auricular deformities.

    PubMed

    Heppt, Werner J

    2004-11-01

    In 1972, in the search for a method to cope with all deformities in protruding ears and other common minor auricular deformities, Claus Walter published a surgical technique based on various incisions and excisions of the cartilage. The procedure consists of a complete separation of the auricle into two parts, combined with remodeling of antihelical, helical, and lobular structures without use of adjusting sutures. Thus, even in patients with stiff and unyielding cartilage and in revisional surgery, pleasing aesthetic results may be achieved. The recurrence rate has found to be reduced markedly. Considering all pros and cons and optional surgical modifications, the incision-excision technique can be adopted for every protruding ear as well as for lop ears, moderate cup ear deformities, and secondary revisions. Because of the extent of cartilage dissection, this technique is not recommended for beginners but should be restricted to experienced surgeons with profound knowledge of basic remodeling procedures. PMID:15778916

  3. Resonant Laser Incisions: Molecular Targets Using the Free Electron Laser

    NASA Astrophysics Data System (ADS)

    Reinisch, Lou; Bryant, Grady; Ossoff, Robert H.

    1996-03-01

    Laser ablation of tissue for medical incisions is normally concerned with the energy absorption and the subsequent vaporization of intracellular water. Using Fourier transform infrared spectroscopy, we have identified specific non-water resonances within tissues. Then, using the Vanderbilt Free Electron Laser (wavelength tunable from 2 to 10 microns) and our Computer Assisted Surgical Techniques program (to standardize the laser delivery), we have targeted specific molecular resonances for laser incisions and tissue removal. Using both acute and chronic studies, we can map out the resonant action spectrum to improve surgical outcomes. We have modeled these ablation mechanisms and working to establish the link between these ablation mechanisms and wound healing. This work has been supported, in part, by a grant from the Department of Defense, Medical Free Electron Laser Program, ONR Grant #N000149411023.

  4. Dual-incision laparoscopic spleen-preserving distal pancreatectomy

    PubMed Central

    Kim, Eun Young; You, Young Kyoung; Kim, Dong Goo; Lee, Soo Ho; Han, Jae Hyun; Park, Sung Kyun; Na, Gun Hyung

    2015-01-01

    Laparoscopic spleen-preserving distal pancreatectomy has been widely performed for benign and borderline malignancy in the body or tail of the pancreas when there are not oncologic indications for splenectomy. As the need for minimally invasive procedures to reduce postoperative morbidity and improve the quality of life is increasing, many surgeons have attempted to reduce the number of trocars and incision size to minimize access trauma and scarring. Single-port laparoscopic spleen-preserving distal pancreatectomy is the result of these efforts; however it has many limitations such as technical difficulty and prolonged operation time. In this article, we report the first case of dual-incision laparoscopic spleen-preserving distal pancreatectomy, proving that it can be a safe and feasible minimally invasive procedure for benign or borderline malignant tumors in the body or tail of the pancreas. PMID:25741499

  5. Modified Lanz incision in appendicectomy - the surgical trainees best friend.

    PubMed

    O'Neill, S; Abdelaziz, E A; Andrabi, S I

    2010-01-01

    Appendicitis is one of the commonest acute surgical diseases and treatment by appendicectomy is the most frequently performed surgical procedure in the western world. After obtaining adequate basic surgical experience, an open appendicectomy is an ideal procedure for junior surgical trainees to develop their operative skills and despite a reduction in training hours, recent figures suggest that surgical SHOs still perform about 30% of these cases. Although they are clearly routine and suitable for junior staff to perform under supervision, as many as 20% of appendicectomies, are for a variety of reasons considered difficult. We aim to be the first to present a modified Lanz incision that we believe provides not only a cosmetic scar but also is placed more frequently over the base of the appendix. It gives adequate access in difficult cases and we feel this is the most appropriate incision for a trainee to use when performing an appendicectomy. PMID:19897062

  6. Small-incision manual extracapsular cataract extraction using selective hydrodissection.

    PubMed

    Blumenthal, M; Ashkenazi, I; Assia, E; Cahane, M

    1992-10-01

    Hydrodissection is a technique in which balanced salt solution is injected through a cannula into various layers of a cataractous lens to separate the lens lamella in a nonspecific location. Selective hydrodissection allows separation of the lens lamella at different desired anatomical layers. The technique allows the smallest possible nucleus, ie, the hard-core nucleus, to be hydroexpressed as a separate entity, requiring, correspondingly, a relatively small capsulorhexis and limbal incision. Then, in a second maneuver, the epinucleus, which engulfs the hardcore nucleus to form the adult nucleus, also can be aspirated or hydroexpressed as a whole. Selective hydrodissection permits scleral incision and stitchless surgery in planned extracapsular cataract extraction and also may serve as an intermediate step for surgeons who wish to convert to or learn phacoemulsification techniques. PMID:1436973

  7. Gamma Knife radiosurgery with CT image-based dose calculation.

    PubMed

    Xu, Andy Yuanguang; Bhatnagar, Jagdish; Bednarz, Greg; Niranjan, Ajay; Kondziolka, Douglas; Flickinger, John; Lunsford, L Dade; Huq, M Saiful

    2015-01-01

    The Leksell GammaPlan software version 10 introduces a CT image-based segmentation tool for automatic skull definition and a convolution dose calculation algorithm for tissue inhomogeneity correction. The purpose of this work was to evaluate the impact of these new approaches on routine clinical Gamma Knife treatment planning. Sixty-five patients who underwent CT image-guided Gamma Knife radiosurgeries at the University of Pittsburgh Medical Center in recent years were retrospectively investigated. The diagnoses for these cases include trigeminal neuralgia, meningioma, acoustic neuroma, AVM, glioma, and benign and metastatic brain tumors. Dose calculations were performed for each patient with the same dose prescriptions and the same shot arrangements using three different approaches: 1) TMR 10 dose calculation with imaging skull definition; 2) convolution dose calculation with imaging skull definition; 3) TMR 10 dose calculation with conventional measurement-based skull definition. For each treatment matrix, the total treatment time, the target coverage index, the selectivity index, the gradient index, and a set of dose statistics parameters were compared between the three calculations. The dose statistics parameters investigated include the prescription isodose volume, the 12 Gy isodose volume, the minimum, maximum and mean doses on the treatment targets, and the critical structures under consideration. The difference between the convolution and the TMR 10 dose calculations for the 104 treatment matrices were found to vary with the patient anatomy, location of the treatment shots, and the tissue inhomogeneities around the treatment target. An average difference of 8.4% was observed for the total treatment times between the convolution and the TMR algorithms. The maximum differences in the treatment times, the prescription isodose volumes, the 12 Gy isodose volumes, the target coverage indices, the selectivity indices, and the gradient indices from the convolution

  8. Lung Resection Using Transumbilical Incision: An Animal Survival Study

    PubMed Central

    Yin, Shun-Ying; Yen-Chu; Wu, Yi-Cheng; Liu, Chien-Ying; Hsieh, Ming-Ju; Yuan, Hsu-Chia; Ko, Po-Jen

    2015-01-01

    Introduction: Transumbilical single-port surgery is a potentially less invasive approach to many types of abdominal surgeries and offers better cosmetic outcomes than conventional 3-port laparoscopic surgery. It avoids the complication of intercostal neuralgia and may reduce the risk of pulmonary complications after video-assisted thoracic surgery. This study evaluated the feasibility of transumbilical lung wedge resection. Methods: Lung resection was performed in 11 beagle dogs weighing 5.9 to 8.5 kg. A 3-cm umbilical incision and one diaphragmatic incision were made, and an endoscopic stapler was used. The diaphragmatic incisions were repaired under video guidance using a V-Loc knotless suturing device (Covidien, Mansfield, Massachusetts). Animals were monitored daily for signs of postoperative infection. White blood cell count, C-reactive protein level, and IL-6 level were measured in all animals. Animals were euthanized 14 days after surgery and underwent necropsy evaluation. Results: Accurate lung resection was achieved in 10 of 11 animals during a median operative time of 98 minutes (range 60–165). In 1 animal, transumbilical lung resection was not possible and was converted to thoracotomy. All animals survived without major postoperative complications. At necropsy, evidence of uneventful healing of the stapled resection margin and diaphragmatic wound were found. There was no evidence of vital organ injury or intrathoracic infection. Conclusion: A transumbilical approach to thoracic cavity exploration and stapled lung resection is technically feasible. Primary suturing of the diaphragmatic incision is a simple and effective means of diaphragmatic wound closure. This may be an alternative to video-assisted thoracic surgery for the management of simple thoracic disease. PMID:25848173

  9. Single-Incision Laparoscopic Colon and Rectal Surgery

    PubMed Central

    Keller, Deborah S.; Haas, Eric M.

    2015-01-01

    Single-incision laparoscopic surgery (SILS) was introduced to further the enhanced outcomes of multiport laparoscopy. Multiple studies have demonstrated the safety and feasibility of SILS for both benign and malignant colorectal disease. SILS provides the potential for improved cosmesis, postoperative outcomes, and patient quality of life. However, widespread use has been limited by technical demands and lack of an evidence and competency-based curriculum. PMID:26491404

  10. Mini incision open pyeloplasty - Improvement in patient outcome

    PubMed Central

    Singh, Vishwajeet; Garg, Manish; Sharma, Pradeep; Sinha, Rahul Janak; Kumar, Manoj

    2015-01-01

    ABSTRACT Purpose: To assess the subjective and objective outcomes of mini-incision dismembered Anderson-Hynes pyeloplasty in the treatment of primary ureteropelvic junction obstruction (UPJO). Materials and Methods: Between January 2008 to January 2013, Anderson-Hynes pyeloplasty was performed in 71 patients diagnosed with primary UPJO. Small subcostal muscle splitting incision was used in all cases. Sixteen patients with renal calculi underwent concomitant pyelolithotomy. Subjective outcome was assessed using visual pain analogue score (VAS). For objective assessment, the improvement in differential renal function (DRF) and radio-tracer wash out time (T1/2) on Tc-99m DTPA scan and decrease in hydronephrosis (HDN) on renal ultrasound (USG) and urography (IVU) were assessed. Results: Mean incision length was 5.2 cm. The average operating time and postoperative hospital stay was 63 (52-124) minutes and 2.5 (2–6) days respectively. Concomitant renal calculi were successfully removed in all the patients. Overall complication rates were 8.4% and overall success rate was 98.6% at median follow-up of 16 months. There was significant improvement in pain score (p=0.0001) and significant decrease in HDN after the procedure. While preoperative mean T1/2 was 26.7±6.4 minutes, postoperative half-time decreased to 7.8±4.2 minutes at 6 months and to 6.7±3.3 minutes at 1 year. Mean pre-operative DRF was 26.45% and it was 31.38% and 33.19% at 6 months and 1 year respectively. Conclusions: Mini-incision pyeloplasty is a safe and effective technique with combined advantage of high success rates of standard open pyeloplasty with decreased morbidity of laparoscopic approach. Excellent functional and objective outcomes can be achieved without extra technical difficulty. PMID:26689518

  11. Surgical robot for single-incision laparoscopic surgery.

    PubMed

    Choi, Hyundo; Kwak, Ho-Seong; Lim, Yo-An; Kim, Hyung-Joo

    2014-09-01

    This paper introduces a novel surgical robot for single-incision laparoscopic surgeries. The robot system includes the cone-type remote center-of-motion (RCM) mechanism and two articulated instruments having a flexible linkage-driven elbow. The RCM mechanism, which has two revolute joints and one prismatic joint, is designed to maintain a stationary point at the apex of the cone shape. By placing the stationary point on the incision area, the mechanism allows a surgical instrument to explore the abdominal area through a small incision point. The instruments have six articulated joints, including an elbow pitch joint, which make the triangulation position for the surgery possible inside of the abdominal area. The presented elbow pitch structure is similar to the slider-crank mechanism but the connecting rod is composed of a flexible leaf spring for high payload and small looseness error. We verified the payload of the robot is more than 10 N and described preliminary experiments on peg transfer and suture motion by using the proposed surgical robot. PMID:24835120

  12. Bedrock incision by bedload: insights from direct numerical simulations

    NASA Astrophysics Data System (ADS)

    Aubert, Guilhem; Langlois, Vincent J.; Allemand, Pascal

    2016-04-01

    Bedload sediment transport is one of the main processes that contribute to bedrock incision in a river and is therefore one of the key control parameters in the evolution of mountainous landscapes. In recent years, many studies have addressed this issue through experimental setups, direct measurements in the field, or various analytical models. In this article, we present a new direct numerical approach: using the classical methods of discrete-element simulations applied to granular materials, we explicitly compute the trajectories of a number of pebbles entrained by a turbulent water stream over a rough solid surface. This method allows us to extract quantitatively the amount of energy that successive impacts of pebbles deliver to the bedrock, as a function of both the amount of sediment available and the Shields number. We show that we reproduce qualitatively the behaviour observed experimentally by Sklar and Dietrich (2001) and observe both a "tool effect" and a "cover effect". Converting the energy delivered to the bedrock into an average long-term incision rate of the river leads to predictions consistent with observations in the field. Finally, we reformulate the dependency of this incision rate with Shields number and sediment flux, and predict that the cover term should decay linearly at low sediment supply and exponentially at high sediment supply.

  13. Pleistocene drainage incision in the upper Mississippi Valley Driftless Area

    SciTech Connect

    Knox, J.C.

    1985-01-01

    The deep dissection of the Wisconsin Driftless Area and topographically similar, but glaciated areas in adjacent states is generally acknowledged to have occurred during the Pleistocene, but the precise chronology has been poorly understood. The distribution of pre-Illinoian glacial outwash gravels on uplands and valley side benches near the Mississippi River, on the western margin of the Wisconsin Driftless Area, indicates that the major incision (50-60 m) of drainage had occurred during the very early Pleistocene. Deposits in cut-off valley meanders, a common feature in the lower reaches of Driftless Area rivers, provide a basis for relative dating of the valley incision. The cut-offs appear to have evolved episodically when, at various times during the Pleistocene, glacial debris blocked the drainages of the Mississippi and Wisconsin Rivers causing massive alluviation of side valley tributaries. A radiocarbon date of 21,910 +/- 350 year B.P., representing a buried soil horizon at 22 m depth and about 9 m above the bedrock floor of a cut-off valley meander and 18 m above the bedrock floor of the adjacent present-day valley, supports stratigraphic interpretations that suggest modest valley incision into bedrock probably occurred during the Illinoian and may have also occurred during the early Wisconsinan.

  14. Erosive dynamics of channels incised by subsurface water flow

    NASA Astrophysics Data System (ADS)

    Lobkovsky, Alexander E.; Smith, Braunen E.; Kudrolli, Arshad; Mohrig, David C.; Rothman, Daniel H.

    2007-09-01

    We propose a dynamical model for channels incised into an erodible bed by subsurface water flow. The model is validated by the time-resolved topographic measurements of channel growth in a laboratory-scale experiment. Surface heights in the experiment are measured via a novel laser-aided imaging technique. The erosion rate in the model is composed of diffusive and advective components as well as a simple driving term due to the seeping water. Steady driving conditions may exist whenever channels are incised into a flat and level erodible bed by a water table replenished via steady (on average) rainfall. Under such steady driving conditions, the model predicts an asymptotically self-similar growing shape for the channel transects. Conversely, given a transect shape that evolved under steady driving conditions and an estimate of the erosion rate at the bottom of the channel, granular transport coefficients can be inferred from the static channel shape. We report an estimate of these transport coefficients for a system of ravines incised into unconsolidated sand in the Apalachicola River basin, Florida.

  15. Air kerma based dosimetry calibration for the Leksell Gamma Knife

    SciTech Connect

    Meltsner, Sheridan Griffin; DeWerd, Larry A.

    2009-02-15

    No accepted official protocol exists for the dosimetry of the Leksell Gamma Knife registered (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial-hemisphere arrangement of 201 individual {sup 60}Co beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself. This article proposes an air kerma based dosimetry protocol using either an in-air or in-acrylic phantom measurement to determine the absorbed dose rate of fields of the 18 mm helmet of a GK unit. A small-volume air ionization chamber was used to make measurements at the physical isocenter of three GK units. The absorbed dose rate to water was determined using a modified version of the AAPM Task Group 21 protocol designed for use with {sup 60}Co-based teletherapy machines. This experimentally determined absorbed dose rate was compared to the treatment planning system (TPS) absorbed dose rate. The TPS used with the GK unit is Leksell GammaPlan. The TPS absorbed dose rate at the time of treatment is the absorbed dose rate determined by the physicist at the time of machine commissioning decay corrected to the treatment date. The TPS absorbed dose rate is defined as absorbed dose rate to water at the isocenter of a water phantom with a radius of 8 cm. Measurements were performed on model B and C Gamma Knife units. The absorbed dose rate to water for the 18 mm helmet determined using air-kerma based calculations is consistently between 1.5% and 2.9% higher than the absorbed dose rate provided by the TPS. These air kerma based measurements allow GK dosimetry to be performed with an established dosimetry protocol and without complications arising from the use of and possible variations in solid phantom material. Measurements were also made with the same ionization chamber in a spherical acrylic phantom for comparison. This methodology will allow further development of calibration methods appropriate for the

  16. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    SciTech Connect

    Womac, A.R.; Igathinathane, C.; Sokhansanj, Shahabaddine; Narayan, S.

    2009-04-01

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.

  17. RELAX: detecting relaxed selection in a phylogenetic framework.

    PubMed

    Wertheim, Joel O; Murrell, Ben; Smith, Martin D; Kosakovsky Pond, Sergei L; Scheffler, Konrad

    2015-03-01

    Relaxation of selective strength, manifested as a reduction in the efficiency or intensity of natural selection, can drive evolutionary innovation and presage lineage extinction or loss of function. Mechanisms through which selection can be relaxed range from the removal of an existing selective constraint to a reduction in effective population size. Standard methods for estimating the strength and extent of purifying or positive selection from molecular sequence data are not suitable for detecting relaxed selection, because they lack power and can mistake an increase in the intensity of positive selection for relaxation of both purifying and positive selection. Here, we present a general hypothesis testing framework (RELAX) for detecting relaxed selection in a codon-based phylogenetic framework. Given two subsets of branches in a phylogeny, RELAX can determine whether selective strength was relaxed or intensified in one of these subsets relative to the other. We establish the validity of our test via simulations and show that it can distinguish between increased positive selection and a relaxation of selective strength. We also demonstrate the power of RELAX in a variety of biological scenarios where relaxation of selection has been hypothesized or demonstrated previously. We find that obligate and facultative γ-proteobacteria endosymbionts of insects are under relaxed selection compared with their free-living relatives and obligate endosymbionts are under relaxed selection compared with facultative endosymbionts. Selective strength is also relaxed in asexual Daphnia pulex lineages, compared with sexual lineages. Endogenous, nonfunctional, bornavirus-like elements are found to be under relaxed selection compared with exogenous Borna viruses. Finally, selection on the short-wavelength sensitive, SWS1, opsin genes in echolocating and nonecholocating bats is relaxed only in lineages in which this gene underwent pseudogenization; however, selection on the functional

  18. Relaxation techniques for stress

    MedlinePlus

    ... Know. February 2013. Available at: nccih.nih.gov/health/stress/relaxation.htm . Accessed September 21, 2015. National Center ... A.D.A.M. Editorial team. Related MedlinePlus Health Topics Stress Browse the Encyclopedia A.D.A.M., Inc. ...

  19. Bedrock River Incision Following Aggradation: Observations from the Waipaoa River Regarding Tributary Response to Mainstem Incision and the Role of Paleotopography

    NASA Astrophysics Data System (ADS)

    Crosby, B. T.; Whipple, K. X.

    2005-12-01

    Following a period of valley-filling aggradation, the form and extent of subsequent alluvial and bedrock incision is governed by the pre-aggradation topography and the position of the channel at the time of incision. We present findings from an extensive along-stream survey of the Waihuka Stream, a tributary to the Waipaoa River on the North Island of New Zealand. Never glaciated, this basin aggraded 5 to 25 m of coarse alluvial sediment during the last glacial period, creating an extensive and distinctive valley-fill surface. ~18 ka, aggradation ceased and a subsequent pulse of fluvial incision abandoned the aggradational surface. At present, the river gorge is incised 25 to 60 m into alluvial fill and mudstone bedrock beneath the top of the aggradational surface. Using a laser range-finder and GPS-enabled GIS surveying tool, we surveyed ~17 km of the Waihuka Stream (4.8×106 m2 to 6.3×107 m2). We collected a longitudinal profile and the relative elevations of fill and strath surfaces exposed in channel banks. We also surveyed a total of ~9 km in 14 tributaries to the Waihuka. Drainage areas of tributaries ranged between 5×105 m2 and 9.9×106 m2. In the Waihuka, we find that the amount of bedrock incision depends on whether the incising channel locally lowered through alluvial fill to reoccupy the preaggradation channel or whether it locally had to cut an entirely new valley into bedrock. Reaches dominated by bedrock incision were observed where alluvial fan deposits laterally shifted the mainstem channel out of the paleovalley and against the opposite bedrock hillslope. The along-stream variation in bed erodability forced by whether the re-incising channel encountered bedrock or alluvium had a significant effect on the propagation of the incision signal into tributaries. Where the channel dominantly re-incised alluvial fill, tributaries have stepped but not dramatically over-steepened longitudinal profiles that appear to be adjusting to the new base-level. In

  20. Gamma Knife radiosurgery for the treatment of cavernous sinus hemangiomas

    PubMed Central

    XU, QINGSHENG; SHEN, JIAN; FENG, YIPING; ZHAN, RENYA

    2016-01-01

    The present retrospective study aimed to analyze the outcome of patients with cavernous sinus hemangioma (CSH) treated with Gamma Knife radiosurgery (GKS). Between August 2011 and April 2014, 7 patients with CSHs underwent GKS. GKS was performed as the sole treatment option in 5 patients, whilst partial resection had been performed previously in 1 patient and biopsy had been performed in 1 patient. The mean volume of the tumors at the time of GKS was 12.5±10.2 cm3 (range, 5.3–33.2 cm3), and the median prescription of peripheral dose was 14.0 Gy (range, 10.0–15.0 Gy). The mean follow-up period was 20 months (range, 6–40 months). At the last follow-up, the lesion volume had decreased in all patients, and all cranial neuropathies observed prior to GKS had improved. There were no radiation-induced neuropathies or complications during the follow-up period. GKS appears to be an effective and safe treatment modality for the management of CSHs. PMID:26893777

  1. Measurement of Gamma Knife registered helmet factors using MOSFETs

    SciTech Connect

    Kurjewicz, Laryssa; Berndt, Anita

    2007-03-15

    The relative dose rate for the different Gamma Knife registered helmets (4, 8, 14, and 18 mm) is characterized by their respective helmet factors. Since the plateau of the dose profile for the 4 mm helmet is at most 1 mm wide, detector choices are limited. Traditionally helmet factors have been measured using 1x1x1 mm{sup 3} thermoluminescent dosimeters (TLDs). However, these are time-consuming, cumbersome measurements. This article investigates the use of metal-oxide-semiconductor field effect transistors (MOSFETs) (active area of 0.2x0.2 mm{sup 2}) as a more accurate and convenient dosimeter. Their suitability for these measurements was confirmed by basic characterization measurements. Helmet factors were measured using both MOSFETs and the established TLD approach. A custom MOSFET cassette was designed in analogy to the Elekta TLD cassette (Elekta Instruments AB) for use with the Elekta dosimetry sphere. Although both dosimeters provided values within 3% of the manufacturer's suggestion, MOSFETs provided superior accuracy and precision, in a fraction of the time required for the TLD measurements. Thus, MOSFETs proved to be a reasonable alternative to TLDs for performing helmet factor measurements.

  2. Class characteristics of serrated knife stabs to cartilage.

    PubMed

    Pounder, Derrick J; Cormack, Lesley; Broadbent, Elizabeth; Millar, John

    2011-06-01

    A total of 136 stab wounds were made in cartilage with 8 serrated knives and 72 stabs with 4 nonserrated knives. The walls of the stab track were documented by photography, cast with dental impression material, and the casts photographed. Staining the translucent cartilage surface with blue or green food dye improved photography. Serrated blades produced striations on cartilage in all stabbings. Patterns of blade serration beyond the broad categories of coarse and fine were recognizable. The overall pattern of striations was "irregularly regular." The distance between the blade-spine wound end and the first serration striation is a class characteristic of the knife which produced the defect, as are distances to the subsequent serration striations, which become ever close together and eventually merge near the blade-edge wound end. Serrated knives may be ground (scalloped) on either the left side or the right side of the blade and this class characteristic is identifiable from the walls of the wound track, on which the scalloped blade surface produces broad ridges and narrow striation valleys, with a reverse image on the opposing wound wall. A drop point serrated blade consistently produced an additional oblique mark angled from the blade-spine wound end, accurately reflecting the shape of the blade tip, and representing a chatter mark. PMID:20407362

  3. Ruptured Pseudoaneurysm after Gamma Knife Surgery for Vestibular Schwannoma

    PubMed Central

    MURAKAMI, Mamoru; KAWARABUKI, Kentaro; INOUE, Yasuo; OHTA, Tsutomu

    2016-01-01

    Ruptured aneurysms of anterior inferior cerebellar artery (AICA) after radiotherapy for vestibular schwannoma (VS) are rare, and no definite treatment has been established for distal AICA pseudoaneurysms. We describe a 61-year-old man who underwent Gamma Knife surgery (GKS) for left VS. Follow-up magnetic resonance imaging (MRI) revealed partial regression of the tumor. Twelve years after GKS, he suffered from subarachnoid hemorrhage. Initial angiogram showed no vascular lesions; second left vertebral angiogram, 10 days after admission, demonstrated a pseudoaneurysm in the lateral pontine segment of the left AICA. The proximal portion of the AICA was occluded by a coil. Postoperative MRI revealed an infarction on the left side of the pons and brachium pontis. Although the patient suffered from mild postoperative cerebellar ataxia and facial and abducens nerve palsy, he was discharged 1 month postoperatively requiring no assistance with activities of daily living. Twelve months later, he recovered satisfactorily with a modified Rankin Scale grade of 1, and no recanalization of the aneurysm was found on MR angiography. Endovascular parent artery occlusion for ruptured aneurysms at distal AICA carries the risk of brain stem infarction, but should be considered when no other option is available such as after radiotherapy for VS. PMID:26667081

  4. Numerical modeling of tectonically driven river dynamics and deposition in an upland incised valley

    NASA Astrophysics Data System (ADS)

    Bianchi, Valeria; Salles, Tristan; Ghinassi, Massimiliano; Billi, Paolo; Dallanave, Edoardo; Duclaux, Guillaume

    2015-07-01

    Within upstream reaches of incised valleys, fluvial sedimentation occurs where it is controlled by interaction between climate and tectonics. This study focuses on a Plio-Pleistocene fluvial paleovalley, which drained the northeastern margin of Siena basin (northern Apennines, Italy). Valley filling resulted from the interaction between river drainage and active normal faults striking perpendicular and parallel to the main valley. Through numerical modeling, this study aims to refine temporal and spatial mesoscale deposit variations, which highlight the upset of fluvial architectures derived from the interplay between the river system and uplift. Geomorphological and hydrodynamic parameter calibration was performed integrating field studies with paleohydraulic and paleomagnetic data. The numerical model simulates the evolution of valley formation with the development of (i) a pre-tectonic steady state system, followed by (ii) a syntectonic aggradation and avulsion phase, and (iii) a post-tectonic relaxation phase. The syntectonic phase shows fine sediment back-filling upstream of the uplifted area and coarse sediment down-filling downstream of the upwarping. The recorded aggradations are asynchronous with upstream deposition preceding downstream deposition.

  5. Some effects of the microtome knife and electron beam on methacrylate-embedded thin sections.

    PubMed

    MOORE, D H; MORGAN, C; ROSE, H M

    1956-07-25

    A technique for the examination of specimens at low electron beam intensity has been presented. Sections micrographed with this technique showed numerous knife scratches and frequently contained bands running parallel to the knife edge. Banding with an average spacing of 0.2 micro appeared to result from periodic distortion produced by impact of the knife. At the beam intensities customarily employed, differential sublimation and probably flow of the methacrylate resulted in obliteration of the bands and all but the deepest knife scratches. In addition, changes in the size, shape, and orientation of certain structures were noted. Artifacts resulting from incineration or sublimation of tissue components fixed in formalin were illustrated, and the suggestion was made that such instability to the electron beam accounted in part for the differences observed in osmium- and formalin-fixed tissues. The deformation revealed in serial sections was discussed, and it was pointed out that shortening in the axis perpendicular to the knife edge was associated with elongation in the axis parallel to the cutting edge, the elongation usually occurring locally without change in the width of the section. It was noted that the material causing contamination of the surface of sections during examination exhibited no structure but caused progressive loss of contrast. PMID:13357516

  6. Shielding requirements on-site loading and acceptance testing on the Leksell gamma knife.

    PubMed

    Maitz, A H; Lunsford, L D; Wu, A; Lindner, G; Flickinger, J C

    1990-02-01

    On August 14, 1987, the first stereotactic radiosurgical procedure using the gamma knife was performed in North America. Located in a self-contained radiosurgical suite in the basement of Presbyterian-University Hospital in Pittsburgh, Pennsylvania. This device uses 201 highly focused beams 60Co for the single-treatment closed-skull irradiation of brain lesions localized by stereotactic techniques (radiosurgery). One hundred and fifty-two patients with intracranial arteriovenous malformations or brain tumors were treated in the first year of operation. The Presbyterian University Hospital of Pittsburgh gamma knife is the first such unit in which the 60Co sources were loaded on-site. This effort required us to solve some difficult and unusual problems encountered during site preparation, delivery, and loading of the unit in a busy hospital setting. The solutions developed enabled installation and use of the gamma knife with minimal disruption of hospital activities while maintaining acceptable levels of exposure to radiation. Environmental surveys performed during the loading of the 201 radioactive sources (total, 219 TBq) confirmed that on-site loading is possible and practical. Our experience in the design, construction, and implementation of the first North American gamma knife supports the practicality and safety of on-site loading and may be of value in the planning and development of future gamma knife installations. PMID:2406231

  7. Hair Dye and Hair Relaxers

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Hair Dye and Hair Relaxers Share Tweet Linkedin Pin it More sharing ... products. If you have a bad reaction to hair dyes and relaxers, you should: Stop using the ...

  8. Influence of Incision Location on Transmitter Loss, Healing, Survival, Growth, and Suture Retention of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greg L.; Deters, Katherine A.; Woodley, Christa M.; Eppard, M. Brad

    2011-11-01

    Fisheries research involving surgical implantation of transmitters necessitates the use of methods that minimize transmitter loss and fish mortality and optimize healing of the incision. We evaluated the effects of three incision locations on transmitter loss, healing, survival, growth, and suture retention in juvenile Chinook salmon Oncorhynchus tshawytscha. The three incision locations were (1) on the linea alba (LA incision), (2) adjacent and parallel to the LA (muscle-cutting [MC] incision), and (3) extending from the LA towards the dorsum at a 45° angle, between the parallel lines of myomeres (muscle-sparing [MS] incision). A Juvenile Salmon Acoustic Telemetry System acoustic transmitter (0.44 g in air) and a passive integrated transponder tag (0.10 g in air) were implanted into each fish (total N = 936 fish). The fish were held at 12°C or 20°C and were examined weekly for 98 d. The progression of healing among incision locations and the variability in transmitter loss made it difficult to identify one incision location as the best choice. The LA incisions had a much smaller wound extent (area of visible subepidermal tissue) than MC and MS incisions during the first 28 d of the study. In both temperature treatments, apposition of incisions through day 14 was better for LA incisions than for MC and MS incisions. However, MC and MS incisions were less likely than LA incisions to reopen over time and thus were less likely to allow transmitter loss through the incision.

  9. Dielectric Relaxation of Hexadeutero Dimethylsulfoxide

    NASA Astrophysics Data System (ADS)

    Betting, H.; Stockhausen, M.

    1999-11-01

    The dielectric relaxation parameters of the title substance (DMSO-d6) in its pure liquid state are determined from meas-urements up to 72 GHz at 20°C in comparison to protonated DMSO. While the relaxation strengths do not differ, the relax-ation time of DMSO-d 6 is significantly longer (21.3 ps) than that of DMSO (19.5 ps).

  10. Relaxation in Physical Education Curricula.

    ERIC Educational Resources Information Center

    Coville, Claudia A.

    1979-01-01

    A theoretical framework for incorporating relaxation instruction in the physical education curriculum is presented based on the assumption that relaxation is a muscular-skeletal skill benefitting general motor skill acquisition. Theoretical principles, a definition of relaxation, and an analysis of stages of skill development are also used in the…

  11. Relaxation phenomena in disordered systems

    NASA Astrophysics Data System (ADS)

    Sciortino, F.; Tartaglia, P.

    1997-02-01

    In this article we discuss how the assumptions of self-similarity imposed on the distribution of independently relaxing modes, as well as on their amplitude and characteristic times, manifest in the global relaxation phenomena. We also review recent applications of such approach to the description of relaxation phenomena in microemulsions and molecular glasses.

  12. A Comparison of Relaxation Strategies.

    ERIC Educational Resources Information Center

    Matthews, Doris B.

    Some researchers argue that all relaxation techniques produce a single relaxation response while others support a specific-effects hypothesis which suggests that progressive relaxation affects the musculoskeletal system and that guided imagery affects cognitive changes. Autogenics is considered a technique which is both somatic and cognitive. This…

  13. [Stereotactic Body Radiotherapy with CyberKnife®for Liver Metastases from Colorectal Cancer].

    PubMed

    Mihara, Koki; Kaihara, Masaki; Sunahori, Sayaka; Yamashiro, Naotsugu; Nishiya, Shin; Ito, Yasuhiro; Funakoshi, Kazuto; Egawa, Tomohisa; Tsukamoto, Nobuhiro; Nagashima, Atsushi

    2015-10-01

    For treatment of colorectal liver metastases, liver resection is recommended for resectable cases in the clinical guidelines for colorectal cancer. On the other hand, there are currently no data supporting the efficacy of radiation therapy as a topical treatment, and this treatment can therefore not presently be recommended. With CyberKnife®, it is possible to perform stereotactic radiation therapy using a linear accelerator with high accuracy, even for lesions in the trunk area such as liver metastases. Between December 2009 and September 2014 in our hospital, we performed radiation treatment using CyberKnife® for 14 cases with 22 colorectal liver metastases. As a result, we obtained response and local control rates of 76.2%and 81.0%, respectively. Moreover, no advanced adverse events were observed. Thus, we consider that CyberKnife® treatment for colorectal liver metastases is effective as a topical treatment, with low invasiveness and high safety. PMID:26489566

  14. Jael syndrome: removal of a knife blade impacted in the maxillofacial region under local anaesthesia

    PubMed Central

    Dominguete, Paulo Roberto; Matos, Bruno Figueiredo; Meyer, Tufi Neder; Oliveira, Lucinei Roberto

    2013-01-01

    The presence of retained foreign bodies in the maxillofacial region as a consequence of penetrating injuries from knives is poorly documented in the scientific literature. This manuscript reports the case of a 30-year-old Caucasian with a knife blade lodged in the maxillofacial skeleton. Following clinical and radiographic exams, it was determined that the object had penetrated through the left nostril and nasal septum, in the direction of the right maxillary sinus, and remained impacted without causing injury to important anatomical structures. After systemic assessment and determination of the exact location of the knife blade, the object was removed in an outpatient setting under local anaesthesia. This manuscript aims to report a rare case of a transfacial penetrating injury involving a knife blade that was removed in an outpatient setting while also discussing the proper conduct and treatment options for similar cases in the context of a brief literature review. PMID:23580680

  15. Acute necrosis after Gamma Knife surgery in vestibular schwannoma leading to multiple cranial nerve palsies.

    PubMed

    Kapitza, Sandra; Pangalu, Athina; Horstmann, Gerhard A; van Eck, Albert T; Regli, Luca; Tarnutzer, Alexander A

    2016-08-01

    We discuss a rare acute complication after Gamma Knife therapy (Elekta AB, Stockholm, Sweden) in a single patient. A 52-year-old woman presented with vertigo, facial weakness and hearing loss emerging 48hours following Gamma Knife radiosurgery for a right-sided vestibular schwannoma. Neurological examination 6days after symptom onset showed right-sided facial palsy, spontaneous left-beating nystagmus and pathologic head-impulse testing to the right. Pure-tone audiogram revealed right-sided sensorineural hearing loss. A diagnosis of acute vestibulocochlear and facial neuropathy was made. Brain MRI demonstrated focal contrast sparing within the schwannoma, likely related to acute radiation necrosis. Acute multiple cranial neuropathies of the cerebellopontine angle after Gamma Knife treatment should raise suspicion of acute tissue damage within the schwannoma and should result in urgent MRI. Treatment with steroids may be considered based on accompanying swelling and edema. PMID:26947104

  16. [Acupoint position and manipulation of needle knife treating shoulder bi syndrome].

    PubMed

    Zhao, Li; Guo, Changqing

    2016-03-01

    With Jianyu (LI 15), Jianliao (TE 14) and Jianzhen (SI 9) for instance, the three acupoints used to treat shoulder bi syndrome by needle knife, and through traceability and researching constant structure, the acupoint position, insertion trace, manipulation and clinical significance of needle knife medicine were discussed. Accurate position is one of the characteristics of acupoints selection of needle knife medicine. As for the acupoints selection method, the mean of body surface localization is always used. The phanerous or palpable bone processes, muscles and tendons are taken as positioning marks; pressing areas where appear sour, numb, or distensible and other sensations is considered as the principle of press positioning. So acupoints position method is the combination of observation and palpation. Different insertion methods can effectively relieve the accretive bursae synovialis, tendon, joint capsule and the compressed nerve, so that shoulder bi syndrome is relieved. PMID:27344840

  17. Wound construction in manual small incision cataract surgery

    PubMed Central

    Haldipurkar, S S; Shikari, Hasanain T; Gokhale, Vishwanath

    2009-01-01

    The basis of manual small incision cataract surgery is the tunnel construction for entry to the anterior chamber. The parameters important for the structural integrity of the tunnel are the self-sealing property of the tunnel, the location of the wound on the sclera with respect to the limbus, and the shape of the wound. Cataract surgery has gone beyond just being a means to get the lens out of the eye. Postoperative astigmatism plays an important role in the evaluation of final outcome of surgery. Astigmatic consideration, hence, forms an integral part of incisional considerations prior to surgery. PMID:19075401

  18. Metal Fatigue Causing Cystoscope Rupture During Bladder Neck Incision

    PubMed Central

    Fernandez, Alfonso

    2011-01-01

    The modern cystoscope is the result of the advancement in technology in numerous areas and is an invaluable tool that allows the urologist to perform a number of diagnostic and therapeutic procedures. Although various degrees of endoscope failure have been widely reported, instrument breakage that leads to a foreign body has not. While performing a bladder neck stricture incision for a 72-year-old male patient with a previous radical prostatectomy for prostate cancer and a resulting bladder neck stricture, we documented a major 17-French cystoscope malfunction and a resulting foreign body that was retrieved from the bladder using a 22-French scope and alligator forceps. PMID:21985739

  19. Review of single incision laparoscopic surgery in colorectal surgery

    PubMed Central

    Madhoun, Nisreen; Keller, Deborah S; Haas, Eric M

    2015-01-01

    As surgical techniques continue to move towards less invasive techniques, single incision laparoscopic surgery (SILS), a hybrid between traditional multiport laparoscopy and natural orifice transluminal endoscopic surgery, was introduced to further the enhanced outcomes of multiport laparoscopy. The safety and feasibility of SILS for both benign and malignant colorectal disease has been proven. SILS provides the potential for improved cosmesis, postoperative pain, recovery time, and quality of life at the drawback of higher technical skill required. In this article, we review the history, describe the available technology and techniques, and evaluate the benefits and limitations of SILS for colorectal surgery in the published literature. PMID:26478673

  20. Conjunctival inclusion cysts following small incision cataract surgery.

    PubMed

    Narayanappa, Shylaja; Dayananda, S; Dakshayini, M; Gangasagara, Suresh Babu; Prabhakaran, Venkatesh C

    2010-01-01

    The occurrence of acquired conjunctival inclusion cysts following various ophthalmic surgeries such as strabismus surgery, scleral buckling, pars plana vitrectomy, ptosis surgery and phacoemulsification has been reported. We report two cases of conjunctival inclusion cysts following manual Small Incision Cataract Surgery (SICS) in two male patients aged 65 and 67 years. The cysts originated from the scleral tunnel used for manual SICS. Both were treated by excision and confirmed histopathologically. No recurrence was noted at three months follow-up. To our knowledge, conjunctival inclusion cysts following SICS have not been reported previously. Careful reflection of conjunctiva during tunnel construction and posterior chamber intraocular lens implantation may prevent their occurrence. PMID:20689201

  1. Adaptive hypofractionated gamma knife radiosurgery for a large brainstem metastasis

    PubMed Central

    Sinclair, Georges; Bartek, Jiri; Martin, Heather; Barsoum, Pierre; Dodoo, Ernest

    2016-01-01

    Background: To demonstrate how adaptive hypofractionated radiosurgery by gamma knife (GK) can be successfully utilized to treat a large brainstem metastasis - a novel approach to a challenging clinical situation. Case Description: A 42-year-old woman, diagnosed with metastatic nonsmall cell lung cancer in July 2011, initially treated with chemotherapy and tyrosine kinase inhibitors, developed multiple brain metastases March 2013, with subsequent whole brain radiotherapy, after which a magnetic resonance imaging (MRI) showed a significant volume regression of all brain metastases. A follow-up MRI in October 2013 revealed a growing brainstem lesion of 26 mm. Linear accelerator-based radiotherapy and microsurgery were judged contraindicated, why the decision was made to treat the patient with three separate radiosurgical sessions during the course of 1 week, with an 18% tumor volume reduction demonstrated after the last treatment. Follow-up MRI 2.5 months after her radiosurgical treatment showed a tumor volume reduction of 67% compared to the 1st day of treatment. Later on, the patient developed a radiation-induced perilesional edema although without major clinical implications. An MRI at 12 months and 18-fluoro-deoxyglucose positron emission tomography of the brain at 13 months showed decreased edema with no signs of tumor recurrence. Despite disease progression during the last months of her life, the patient's condition remained overall acceptable. Conclusion: GK-based stereotactic adaptive hypofractionation proved to be effective to achieve tumor control while limiting local adverse reactions. This surgical modality should be considered when managing larger brain lesions in critical areas. PMID:26958430

  2. Gamma knife surgery for epilepsy related to hypothalamic hamartomas.

    PubMed

    Régis, Jean; Scavarda, Didier; Tamura, Manabu; Villeneuve, Nathalie; Bartolomei, Fabrice; Brue, Thierry; Morange, Isabelle; Dafonseca, David; Chauvel, Patrick

    2007-06-01

    Numerous neurosurgical approaches are available for children presenting with hypothalamic hamartomas (HHs) associated with severe epilepsy. A concern regarding the impairment of short-term memory after resective surgery is promoting the exploration of less invasive alternatives like radiosurgery. Gamma knife radiosurgery (GKS) can lead to a real reversal of the epileptic encephalopathy. Three years after radiosurgery, 60% of the children have an excellent result with complete seizure cessation in 40% and rare nondisabling seizures in 20%, often in association with dramatic behavioral and cognitive improvement. No permanent neurologic complications have thus far been reported. Rare transient cases of poikilothermia have been observed. GKS is clearly the safer approach for these difficult patients. Young patients with severe epilepsy and neurocognitive comorbidity must be treated by using a curative approach as early as possible. Topological type (according to our original classification) is the major feature for selection of the best treatment strategy. Type I HH deeply embedded in the hypothalamus is treated safely and efficiently by GKS. Type II HH can be resected by either endoscopic or transcallosal approaches or treated by GKS depending on the parent's choice and severity of epilepsy. In small type III HH, GKS is the safer procedure because of the very close relationship to the fornix and mammillary bodies. Types V (rarely epileptic) and IV are frequently operable by disconnection. Very large type VI (or mixed type) with a large component above the floor of the third ventricle must be disconnected, and then the upper remnant is best treated by GKS using a staged technique. Overall, when the lesion is sufficiently small, GKS offers a rate of seizure control comparable to microsurgery but with much lower risk. The disadvantage of radiosurgery is its delayed action. Longer follow-up is mandatory for a reliable evaluation of the role of GKS. PMID:17544950

  3. Salvage Gamma Knife Stereotactic Radiosurgery for Surgically Refractory Trigeminal Neuralgia

    SciTech Connect

    Little, Andrew S.; Shetter, Andrew G. Shetter, Mary E.; Kakarla, Udaya K.; Rogers, C. Leland

    2009-06-01

    Purpose: To evaluate the clinical outcome of patients with surgically refractory trigeminal neuralgia (TN) treated with rescue gamma knife radiosurgery (GKRS). Methods and Materials: Seventy-nine patients with typical TN received salvage GKRS between 1997 and 2002 at the Barrow Neurological Institute (BNI). All patients had recurrent pain following at least one prior surgical intervention. Prior surgical interventions included percutaneous destructive procedures, microvascular decompression (MVD), or GKRS. Thirty-one (39%) had undergone at least two prior procedures. The most common salvage dose was 80 Gy, although 40-50 Gy was typical in patients who had received prior radiosurgery. Pain outcome was assessed using the BNI Pain Intensity Score, and quality of life was assessed using the Brief Pain Inventory. Results: Median follow-up after salvage GKRS was 5.3 years. Actuarial analysis demonstrated that at 5 years, 20% of patients were pain-free and 50% had pain relief. Pain recurred in patients who had an initial response to GKRS at a median of 1.1 years. Twenty-eight (41%) required a subsequent surgical procedure for recurrence. A multivariate Cox proportional hazards model suggested that the strongest predictor of GKRS failure was a history of prior MVD (p=0.029). There were no instances of serious morbidity or mortality. Ten percent of patients developed worsening facial numbness and 8% described their numbness as 'very bothersome.' Conclusions: GKRS salvage for refractory TN is well tolerated and results in long-term pain relief in approximately half the patients treated. Clinicians may reconsider using GKRS to salvage patients who have failed prior MVD.

  4. Gamma Knife Radiosurgery for the Treatment of Cystic Cerebral Metastases

    SciTech Connect

    Ebinu, Julius O.; Lwu, Shelly; Monsalves, Eric; Arayee, Mandana; Chung, Caroline; Laperriere, Normand J.; Kulkarni, Abhaya V.; Goetz, Pablo; Zadeh, Gelareh

    2013-03-01

    Purpose: To assess the role of Gamma Knife radiosurgery (GKRS) in the treatment of nonsurgical cystic brain metastasis, and to determine predictors of response to GKRS. Methods: We reviewed a prospectively maintained database of brain metastases patients treated at our institution between 2006 and 2010. All lesions with a cystic component were identified, and volumetric analysis was done to measure percentage of cystic volume on day of treatment and consecutive follow-up MRI scans. Clinical, radiologic, and dosimetry parameters were reviewed to establish the overall response of cystic metastases to GKRS as well as identify potential predictive factors of response. Results: A total of 111 lesions in 73 patients were analyzed; 57% of lesions received prior whole-brain radiation therapy (WBRT). Lung carcinoma was the primary cancer in 51% of patients, 10% breast, 10% colorectal, 4% melanoma, and 26% other. Fifty-seven percent of the patients were recursive partitioning analysis class 1, the remainder class 2. Mean target volume was 3.3 mL (range, 0.1-23 mL). Median prescription dose was 21 Gy (range, 15-24 Gy). Local control rates were 91%, 63%, and 37% at 6, 12, and 18 months, respectively. Local control was improved in lung primary and worse in patients with prior WBRT (univariate). Only lung primary predicted local control in multivariate analysis, whereas age and tumor volume did not. Lesions with a large cystic component did not show a poorer response compared with those with a small cystic component. Conclusions: This study supports the use of GKRS in the management of nonsurgical cystic metastases, despite a traditionally perceived poorer response. Our local control rates are comparable to a matched cohort of noncystic brain metastases, and therefore the presence of a large cystic component should not deter the use of GKRS. Predictors of response included tumor subtype. Prior WBRT decreased effectiveness of SRS for local control rates.

  5. Clinical outcomes following salvage Gamma Knife radiosurgery for recurrent glioblastoma

    PubMed Central

    Larson, Erik W; Peterson, Halloran E; Lamoreaux, Wayne T; MacKay, Alexander R; Fairbanks, Robert K; Call, Jason A; Carlson, Jonathan D; Ling, Benjamin C; Demakas, John J; Cooke, Barton S; Lee, Christopher M

    2014-01-01

    Glioblastoma multiforme (GBM) is the most common malignant primary brain tumor with a survival prognosis of 14-16 mo for the highest functioning patients. Despite aggressive, multimodal upfront therapies, the majority of GBMs will recur in approximately six months. Salvage therapy options for recurrent GBM (rGBM) are an area of intense research. This study compares recent survival and quality of life outcomes following Gamma Knife radiosurgery (GKRS) salvage therapy. Following a PubMed search for studies using GKRS as salvage therapy for malignant gliomas, nine articles from 2005 to July 2013 were identified which evaluated rGBM treatment. In this review, we compare Overall survival following diagnosis, Overall survival following salvage treatment, Progression-free survival, Time to recurrence, Local tumor control, and adverse radiation effects. This report discusses results for rGBM patient populations alone, not for mixed populations with other tumor histology grades. All nine studies reported median overall survival rates (from diagnosis, range: 16.7-33.2 mo; from salvage, range: 9-17.9 mo). Three studies identified median progression-free survival (range: 4.6-14.9 mo). Two showed median time to recurrence of GBM. Two discussed local tumor control. Six studies reported adverse radiation effects (range: 0%-46% of patients). The greatest survival advantages were seen in patients who received GKRS salvage along with other treatments, like resection or bevacizumab, suggesting that appropriately tailored multimodal therapy should be considered with each rGBM patient. However, there needs to be a randomized clinical trial to test GKRS for rGBM before the possibility of selection bias can be dismissed. PMID:24829861

  6. The guillotine knife: a novel tool for safe endoscopic cutting of intracranial membranes.

    PubMed

    El Damaty, Ahmed; Manwaring, Jotham C; Schroeder, Henry W S

    2014-09-01

    This article describes a new endoscopic cutting tool that acts like a guillotine. It enables safe cutting of membranes overlying neurovascular structures because the footplate protects these structures from inadvertent injury. The footplate is introduced under the membrane, elevating it slightly, and then the membrane is cut while pushing the blade down into the footplate. The guillotine knife has been used in various endoscopic procedures such as septostomies, arachnoid cyst fenestrations, colloid cysts resections, and fenestrations of other intraventricular membranes. The authors think that the guillotine knife is a useful addition to the neuroendoscopic armamentarium. PMID:24926646

  7. Transurethral incision of prostate compared with transurethral resection of prostate in 132 matching cases.

    PubMed

    Orandi, A

    1987-10-01

    In a prospective project during a 2-year period 132 patients with bladder outlet obstruction who were candidates for transurethral incision of the prostate were managed alternately by transurethral incision and transurethral resection of the prostate. Both operations were compared in matched patients. The results and complications favored transurethral incision, although there was no statistical significance except for the high incidence of bladder neck contracture after transurethral resection (p equals 0.028). PMID:2443728

  8. Correlation between Corneal Endothelial Cell Loss and Location of Phacoemulsification Incision

    PubMed Central

    Gharaee, Hamid; Kargozar, Abbas; Daneshvar-Kakhki, Ramin; Sharepour, Maria; Hassanzadeh, Samira

    2011-01-01

    Purpose To assess the relationship between corneal endothelial cell loss after phacoemulsification and the location of the clear corneal incision. Methods A total of 92 patients (92 eyes) with senile cataracts who met the study criteria were included in this cross sectional study and underwent phacoemulsification. The incision site was determined based on the steep corneal meridian according to preoperative keratometry. Endothelial cell density was measured using specular microscopy in the center and 3 mm from the center of the cornea in the meridian of the incisions (temporal, superior, and superotemporal). Phacoemulsification was performed by a single surgeon using the phaco chop technique through a 3.2 mm clear cornea incision. Endothelial cell loss (ECL) was evaluated 1 week, and 1 and 3 months postoperatively. Results At all time points during follow-up, ECL was comparable among the 3 incision sites, both in the central cornea and in the meridian of the incision (P > 0.05 for all comparisons). However, 3 months postoperatively, mean central ECL with superior incisions and mean sectoral ECL with temporal incisions were slightly higher. Superotemporal incisions entailed slightly less ECL than the other 2 groups. Overall, one month after surgery, mean central ECL was 10.8% and mean ECL in the sector of the incisions was 14.0%. Axial length and effective phaco time (EFT) were independent predictors of postoperative central ECL (P values 0.005 and < 0.0001, respectively). Conclusion A superotemporal phacoemulsification incision may entail less ECL as compared to other incisions (although not significantly different). The amount of central ECL may be less marked in patients with longer axial lengths and with procedures utilizing less EFT. PMID:22454701

  9. Sutureless cataract incision closure using laser-activated tissue glues

    NASA Astrophysics Data System (ADS)

    Eaton, Alexander M.; Bass, Lawrence S.; Libutti, Steven K.; Schubert, Herman D.; Treat, Michael R.

    1991-06-01

    With the advent of phacoemulsification and foldable intraocular lenses, there is renewed interest in sutureless cataract wound. We report the use of laser activated tissue glues for the closure of scleral tunnel cataract incisions. Two glue mixtures were tested in enucleated porcine eyes. Glue A was composed of hyaluronic acid, human albumin, and indocyanine green dye. Glue B contained hyaluronic acid, chondroitin sulfate, human albumin, and indocyanine green dye. A Spectra Physics diode laser (808 nm) with a power density of 7-1 1 watts/cm2 was used for glue activation. Wound bursting pressures, as determined by the presence of fluid at the wound margin, was significantly higher with both glue combinations than without the glue (Pincisions.

  10. Single incision laparoscopic liver resection (SILL) – a systematic review

    PubMed Central

    Benzing, Christian; Krenzien, Felix; Atanasov, Georgi; Seehofer, Daniel; Sucher, Robert; Zorron, Ricardo; Pratschke, Johann; Schmelzle, Moritz

    2015-01-01

    Background: Today, minimally invasive liver resections for both benign and malignant tumors are routinely performed. Recently, some authors have described single incision laparoscopic liver resection (SILL) procedures. Since SILL is a relatively young branch of laparoscopy, we performed a systematic review of the current literature to collect data on feasibility, perioperative results and oncological outcome. Methods: A literature research was performed on Medline for all studies that met the eligibility criteria. Titles and abstracts were screened by two authors independently. A study was included for review if consensus was obtained by discussion between the authors on the basis of predefined inclusion criteria. A thorough quality assessment of all included studies was performed. Data were analyzed and tabulated according to predefined outcome measures. Synthesis of the results was achieved by narrative review. Results: A total of 15 eligible studies were identified among which there was one prospective cohort study and one randomized controlled trial comparing SILL to multi incision laparoscopic liver resection (MILL). The rest were retrospective case series with a maximum of 24 patients. All studies demonstrated convincing results with regards to feasibility, morbidity and mortality. The rate of wound complications and incisional hernia was low. The cosmetic results were good. Conclusions: This is the first systematic review on SILL including prospective trials. The results of the existing studies reporting on SILL are favorable. However, a large body of scientific evidence on the field of SILL is missing, further randomized controlled studies are urgently needed. PMID:26734538

  11. Single-incision laparoscopic surgery for colorectal cancer

    PubMed Central

    Hirano, Yasumitsu; Hattori, Masakazu; Douden, Kenji; Ishiyama, Yasuhiro; Hashizume, Yasuo

    2016-01-01

    AIM: To determine the effect of single-incision laparoscopic colectomy (SILC) for colorectal cancer on short-term clinical and oncological outcomes by comparison with multiport conventional laparoscopic colectomy (CLC). METHODS: A systematic review was performed using MEDLINE for the time period of 2008 to December 2014 to retrieve all relevant literature. The search terms were “laparoscopy”, “single incision”, “single port”, “single site”, “SILS”, “LESS” and “colorectal cancer”. Publications were included if they were randomized controlled trials, case-matched controlled studies, or comparative studies, in which patients underwent single-incision (SILS or LESS) laparoscopic colorectal surgery. Studies were excluded if they were non-comparative, or not including surgery involving the colon or rectum. A total of 15 studies with 589 patients who underwent SILC for colorectal cancer were selected. RESULTS: No significant differences between the groups were noted in terms of mortality or morbidity. The benefit of the SILC approach included reduction in conversion rate to laparotomy, but there were no significant differences in other short-term clinical outcomes between the groups. Satisfactory oncological surgical quality was also demonstrated for SILC for the treatment of colorectal cancer with a similar average lymph node harvest and proximal and distal resection margin length as multiport CLC. CONCLUSION: SILC can be performed safely with similar short-term clinical and oncological outcomes as multiport CLC. PMID:26843918

  12. Rapid incision of the Colorado River in Glen Canyon - insights from channel profiles, local incision rates, and modeling of lithologic controls

    USGS Publications Warehouse

    Cook, K.L.; Whipple, K.X.; Heimsath, A.M.; Hanks, T.C.

    2009-01-01

    The Colorado River system in southern Utah and northern Arizona is continuing to adjust to the baselevel fall responsible for the carving of the Grand Canyon. Estimates of bedrock incision rates in this area vary widely, hinting at the transient state of the Colorado and its tributaries. In conjunction with these data, we use longitudinal profiles of the Colorado and tributaries between Marble Canyon and Cataract Canyon to investigate the incision history of the Colorado in this region. We find that almost all of the tributaries in this region steepen as they enter the Colorado River. The consistent presence of oversteepened reaches with similar elevation drops in the lower section of these channels, and their coincidence within a corridor of high local relief along the Colorado, suggest that the tributaries are steepening in response to an episode of increased incision rate on the mainstem. This analysis makes testable predictions about spatial variations in incision rates; these predictions are consistent with existing rate estimates and can be used to guide further studies. We also present cosmogenic nuclide data from the Henry Mountains of southern Utah. We measured in situ 10Be concentrations on four gravel-covered strath surfaces elevated from 1 m to 110 m above Trachyte Creek. The surfaces yield exposure ages that range from approximately 2??5 ka to 267 ka and suggest incision rates that vary between 350 and 600 m/my. These incision rates are similar to other rates determined within the high-relief corridor. Available data thus support the interpretation that tributaries of the Colorado River upstream of the Grand Canyon are responding to a recent pulse of rapid incision on the Colorado. Numerical modeling of detachment-limited bedrock incision suggests that this incision pulse is likely related to the upstream-dipping lithologic boundary at the northern edge of the Kaibab upwarp. ?? 2009 John Wiley & Sons, Ltd.

  13. Safety of cesarean delivery through placental incision in patients with anterior placenta previa

    PubMed Central

    Hong, Deok-Ho; Kim, Eugene; Kyeong, Kyu-Sang; Hong, Seung Hwa

    2016-01-01

    Objective To demonstrate the safety of fetal delivery through placental incision in a placenta previa pregnancy. Methods We examined the medical records of 80 women with singleton pregnancy diagnosed with placenta previa who underwent cesarean section between May 2010 and May 2015 at the Department of Obstetrics and Gynecology, Chungbuk National University Hospital. Among the women with placenta previa, those who did not have the placenta in the uterine incision site gave birth via conventional uterine incision, while those with anterior placenta previa or had placenta attached to the uterine incision site gave birth via uterine incision plus placental incision. We compared the postoperative hemoglobin level and duration of hospital stay for the mother and newborn of the two groups. Results There was no difference between the placental incision group and non-incision group in terms of preoperative and postoperative hemoglobin change, the amount of blood transfusions required by the mother, newborns with 1-min or 5-min Apgar scores below 7 points or showing signs of acidosis on umbilical cord blood gas analysis result of pH below 7.20. Moreover, neonatal hemoglobin levels did not differ between the two groups. Conclusion Fetal delivery through placental incision during cesarean section for placenta previa pregnancy does not negatively influence the prognosis of the mother or the newborn, and therefore, is considered a safe surgical technique. PMID:27004200

  14. An episode of rapid bedrock channel incision during the last glacial cycle, measured with 10Be

    USGS Publications Warehouse

    Reusser, L.; Bierman, P.; Pavich, M.; Larsen, J.; Finkel, R.

    2006-01-01

    We use 10Be to infer when, how fast, and why the Susquehanna River incised through bedrock along the U.S. Atlantic seaboard, one of the world's most prominent and ancient passive margins. Although the rate at which large rivers incise rock is a fundamental control on the development of landscapes, relatively few studies have directly measured how quickly such incision occurs either in tectonically active environments or along passive margins. Exposure ages of fluvially carve d, bedrock strath terraces, preserved along the lower Susquehanna River, demonstrate that even along a passive margin, large rivers are capable of incising through rock for short periods of time at rates approaching those recorded in tectonically active regions, such as the Himalayas. Over eighty samples, collected along and between three prominent levels of strath terraces within Holtwood Gorge, indicate that the Susquehanna River incised more than 10 meters into the Appalachian Piedmont during the last glacial cycle. Beginning ???36 ka, incision rates increased dramatically, and remained elevated until ???14 ka. The northern half of the Susquehanna basin was glaciated during the late Wisconsinan; however, similar rates and timing of incision occurred in the unglaciated Potomac River basin immediately to the south. The concurrence of incision periods on both rivers suggests that glaciation and associated meltwater were not the primary drivers of incision. Instead, it appears that changing climatic conditions during the late Pleistocene promoted an increase in the frequency and magnitude of flood events capable of exceeding thresholds for rock detachment and bedrock erosion, thus enabling a short-lived episode of rapid incision into rock. Although this study has constraine d the timing and rate of bedrock incision along the largest river draining the Atlantic passive margin, the dates alone cannot explain fully why, or by what processes, this incision occurred. However, cosmogenic dating offers

  15. Paraglacial fluvial bedrock incision in postglacial landscapes: the NW Scottish Highlands

    NASA Astrophysics Data System (ADS)

    Whitbread, Katie; Jansen, John; Bishop, Paul; Fabel, Derek

    2010-05-01

    Glacial landscape forms are inherited by rivers following deglaciation. Hillslopes and valley floors configured by glacial erosion control the distribution of bedrock channels and potential sites for fluvial incision. The importance of 'stream power' parameters, channel slope and drainage area (discharge), in controlling the rate of incision is widely accepted, but the rate, timing and mechanisms of incision have yet to be quantified in these settings. The dual controls of glacially conditioned bedrock slopes and sediment supply set two of the key boundary conditions for temporally and spatially dynamic fluvial bedrock incision. Measurement of incision rates in these settings is key to understanding the influence of controls on fluvial erosion, and the role of the process in long-term evolution of deglaciated landscapes. In tectonically-passive, hard-rock terrains, such as the Scottish Highlands, incisional fluvial features such as bedrock channels, gorges and waterfalls are common on glacially carved valley steps. Here we report preliminary data on fluvial incision rates measured with cosmogenic 10Be. Our results confirm a postglacial age of bedrock straths in the NW Scottish Highlands and indicate a vertical incision rate of 0.3 mm/yr into resistant quartzites. Further work will explore erosion mechanisms and rates of incision across the Scottish Highlands, and assess controls on fluvial incision, including the potential role of paraglacial sediment.

  16. Comparison of fibrin glue and suture in the healing of teat incisions in lactating goats.

    PubMed

    Alan, M; Yener, Z; Tasal, I; Bakir, B

    2008-05-01

    The aims of this study were to investigate whether fibrin glue can be used to close experimentally induced incisions of the teat (mammary papillae) in lactating goats and to compare the healing of the glued with the sutured incisions. Four clinically healthy lactating dairy goats, namely 8 mammary papillae were used. After surgical preparation of the papillae, a 3.5 cm long incision of each papilla was made through skin, muscular layer and mucosa into the papillary sinus. The wounds in the right papillae in all goats were closed with U-shaped uninterrupted 00 chromic catgut sutures. The wounds in the left papillae in all goats were closed, using fibrin glue. One incision was seen to be dehisced and fistulous one day after in fibrin glued teats. The animals were slaughtered 8 days after surgical manipulation. The mammary papillae were removed and examined in the viewpoint on gross and microscopic findings. The healing of wounds was slower and feeble in glued mammary papillary incisions, however faster and stronger in sutured incisions on day 8 after operations. But, available outcomes like less tissue thickness and positive cosmetic results could be obtained byfibrin glue used on mammary papillary incisions, which are very important for teats to be milked by hand and milking machine. Results suggest that it is advisable to use only one or two simple interrupted sutures in teat incisions glued with fibrin to prevent the dehiscence but with a more reliable healing than the sutured incisions. PMID:18547021

  17. MAGAT gel and EBT2 film-based dosimetry for evaluating source plugging-based treatment plan in Gamma Knife stereotactic radiosurgery.

    PubMed

    Natanasabapathi, Gopishankar; Subbiah, Vivekanandhan; Kale, Shashank Sharad; Rath, Goura Kishor; Senthilkumaran, S; Thulkar, Sanjay; Subramani, Vellaiyan; Laviraj, M A; Bisht, Raj Kishor; Mahapatra, A K

    2012-01-01

    This work illustrates a procedure to assess the overall accuracy associated with Gamma Knife treatment planning using plugging. The main role of source plugging or blocking is to create dose falloff in the junction between a target and a critical structure. We report the use of MAGAT gel dosimeter for verification of an experimental treatment plan based on plugging. The polymer gel contained in a head-sized glass container simulated all major aspects of the treatment process of Gamma Knife radiosurgery. The 3D dose distribution recorded in the gel dosimeter was read using a 1.5T MRI scanner. Scanning protocol was: CPMG pulse sequence with 8 equidistant echoes, TR = 7 s, echo step = 14 ms, pixel size = 0.5mm × 0.5mm, and slice thickness of 2 mm. Using a calibration relationship between absorbed dose and spin-spin relaxation rate (R2), we converted R2 images to dose images. Volumetric dose comparison between treatment planning system (TPS) and gel measurement was accomplished using an in-house MATLAB-based program. The isodose overlay of the measured and computed dose distribution on axial planes was in close agreement. Gamma index analysis of 3D data showed more than 94% voxel pass rate for different tolerance criteria of 3%/2 mm, 3%/1 mm and 2%/2 mm. Film dosimetry with GAFCHROMIC EBT 2 film was also performed to compare the results with the calculated TPS dose. Gamma index analysis of film measurement for the same tolerance criteria used for gel measurement evaluation showed more than 95% voxel pass rate. Verification of gamma plan calculated dose on account of shield is not part of acceptance testing of Leksell Gamma Knife (LGK). Through this study we accomplished a volumetric comparison of dose distributions measured with a polymer gel dosimeter and Leksell GammaPlan (LGP) calculations for plans using plugging. We propose gel dosimeter as a quality assurance (QA) tool for verification of plug-based planning. PMID:23149780

  18. Relaxing music for anxiety control.

    PubMed

    Elliott, Dave; Polman, Remco; McGregor, Richard

    2011-01-01

    The purpose of this investigation was to determine the characteristics of relaxing music for anxiety control. Undergraduate students (N=84) were instructed to imagine themselves in an anxiety producing situation while listening to a selection of 30 music compositions. For each composition, level of relaxation, the factors that either enhanced or detracted from its relaxing potential and the emotional labels attached were assessed. Participants were also asked to state which music components (e.g., tempo, melody) were most conducive to relaxation. Additional information was obtained through the use of a focus group of 6 undergraduate music students. This paper presents details on the characteristics of relaxing-music for anxiety control and emotional labels attached to the relaxing compositions. Furthermore, an importance value has been attached to each of the music components under scrutiny, thus providing an indication of which music components should receive greatest attention when selecting music for anxiety control. PMID:22097099

  19. Dose De-Escalation With Gamma Knife Radiosurgery in the Treatment of Choroidal Melanoma

    SciTech Connect

    Schirmer, Clemens M.; Chan, Michael; Mignano, John; Duker, Jay; Melhus, Christopher S.; Williams, Lloyd B.; Wu, Julian K.; Yao, Kevin C.

    2009-09-01

    Purpose: Single-fraction targeted radiation therapy delivered by the Leksell Gamma Knife system is a minimally invasive treatment option for choroidal melanoma that has been used as an alternative to enucleation, proton beam therapy, or brachytherapy. Previously reported Gamma Knife series involved the treatment of choroidal melanomas with a dose of 40 to 50 Gy at the tumor margin. We report our institutional experience using a significantly lower dose. Methods and Materials: Fourteen patients with choroidal melanoma were treated with the Leksell Gamma Knife at our institution over a 7-year period. The treatment and clinical data were analyzed in a retrospective fashion after a mean follow-up of 32.2 months. Results: The mean dose to the tumor margin was 22.2 {+-} 2.4 Gy (range, 20- 25 Gy). Mean treated tumor volume was 1.1 {+-} 1.2 cc. Local control was achieved in 13 cases (93%). In 1 patient both intraocular spread and distant metastatic disease developed after treatment. Visual function of the affected eye was preserved in 5 patients (36%) at latest follow-up, in 9 patients (64%) visual loss ensued. Mild to moderate radiation toxicity developed in 8 patients. Conclusions: Choroidal melanoma can be safely and effectively treated using Leksell Gamma Knife stereotactic radiosurgery with a marginal dose of less than 25 Gy.

  20. 18. DETAIL OF COMBINATION HANDWASH SINK/KNIFE STERILIZER ON SPLITTERS' PLATFORM; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAIL OF COMBINATION HANDWASH SINK/KNIFE STERILIZER ON SPLITTERS' PLATFORM; KNIVES AND CLEAVERS WERE CLEANED FREQUENTLY BY DIPPING THEM INTO STEAM-HEATED WATER IN THE RECTANGULAR TANK; NOTE FOOT-OPERATED FAUCETS - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  1. Chief Dull Knife Community Is Strengthening the Northern Cheyenne Language and Culture.

    ERIC Educational Resources Information Center

    Littlebear, Richard E.

    2003-01-01

    Language revitalization programs should focus on whether they want to teach the language, teach about the language, teach with the language, or teach the language for academic credit. A program at Chief Dull Knife College (Montana) teaches the Cheyenne language using the Total Physical Response method, which replicates the manner in which first…

  2. CT-Guided Fiducial Placement for CyberKnife Stereotactic Radiosurgery: An Initial Experience

    SciTech Connect

    Sotiropoulou, Evangelia; Stathochristopoulou, Irene; Stathopoulos, Konstantinos; Verigos, Kosmas; Salvaras, Nikolaos; Thanos, Loukas

    2010-06-15

    CyberKnife frameless image-guided radiosurgery has become a widely used system for parenchymal extracranial lesions. Gold fiducials are required for the planning and aiming of CyberKnife therapy. We report our initial experience and describe the technique of positioning tumor markers, under CT guidance. We conducted a retrospective review of 105 patients who were referred for CyberKnife stereotactic radiosurgery at Iatropolis CyberKnife Center in Athens. All patients underwent percutaneous fiducial placement via CT guidance. At the desired location, the 18-G needle was advanced into or near the tumor. Data collected included number and locations of fiducials placed and complications experienced to date. One hundred five patients underwent fiducial placement under CT guidance and a total number of 319 gold seeds were implanted. We experienced one episode of pneumothorax that required drainage, one mild pneumothorax, and three episodes of perifocal pulmonary hemorrhage. In conclusion, fiducial implantation under CT guidance appears to be a safe and efficient procedure, as long as it is performed by an experienced interventional radiologist.

  3. "Liquid Knife" to Fabricate Patterning Single-Crystalline Perovskite Microplates toward High-Performance Laser Arrays.

    PubMed

    Feng, Jiangang; Yan, Xiaoxu; Zhang, Yifan; Wang, Xuedong; Wu, Yuchen; Su, Bin; Fu, Hongbin; Jiang, Lei

    2016-05-01

    A facile and effective "liquid knife" is created by controlling the dewetting process of the liquid precursor, yielding patterning single-crystalline perovskite microplates with uniform size, precise positioning, high quality, and low lasing thresholds. The sizes and location of single-crystalline perovskite are controllable, leading to mode-tunable lasing emission and patterned lasers. PMID:27000628

  4. Development of an air-knife system for highly reproducible fabrication of polydimethylsiloxane microstencils

    NASA Astrophysics Data System (ADS)

    Choi, Jin Ho; Kim, Gyu Man

    2015-08-01

    In this study, an air-knife system was developed for the automated fabrication of polymer microstencils with microscale perforated patterns. Blowing compressed N2 gas through the air knife provided a uniform laminar gas flow of high intensity suitable for perforating holes in the stencil. The polydimethylsiloxane (PDMS) stencil was replicated from a master mold prepared by photolithography. When the prepolymer of PDMS was spin-coated onto the master mold, a thin layer of the prepolymer remained on top of the master's structure and consequently prevented the formation of the perforated patterns. This residual layer was easily removed by the presented air knife. The air-knife system controlled the flow rate of N2 gas and the conveying speed of the master mold; therefore, the system possessed high reproducibility compared to manual gas blowing. Its use reduced the fabrication time for perforated biocompatible polymer microstencils, allowing for their mass production via an automated system. The validity of this suggested method was proven through experiments and was evaluated by application in various fields.

  5. Stereotactic ablative radiotherapy with CyberKnife for advanced thymic carcinoma: a case report

    PubMed Central

    Fan, C.Y.; Huang, W.Y.; Jen, Y.M.; Lin, M.J.; Lin, K.T.

    2015-01-01

    Thymic carcinoma is a rare but lethal mediastinal cancer. The optimal treatment for advanced thymic carcinoma is not yet established. This report is the first known of stereotactic ablative radiotherapy (sabr) with CyberKnife (Accuray, Sunnyvale, CA, U.S.A.) as definitive therapy for thymic carcinoma. The patient, a 70-year-old woman with thymic carcinoma, invasion into neighboring organs, and pleural metastases—underwent CyberKnife sabr at 40 Gy in 5 fractions for two lesions, one in the thymus and one in the right paraspinal pleura. After 61 months of observation, a partial response was observed in the irradiated fields. However, disease progression in the non-irradiated pleura was noted. The patient underwent salvage CyberKnife sabr for the four initially nonirradiated pleural lesions. Computed tomography images obtained 10 months after the salvage therapy revealed a partial response. The patient is living, with progression-free irradiated lesions and no radiation-related toxicity. CyberKnife sabr is feasible for patients who are unable to undergo either surgery or conventionally fractionated radiation therapy. PMID:26628883

  6. Gentlemen (and ladies), choose your weapons: Gamma knife vs. linear accelerator radiosurgery.

    PubMed

    Stieber, Volker W; Bourland, J Daniel; Tome, Wolfgang A; Mehta, Minesh P

    2003-04-01

    This article compares and contrasts Gamma Knife radiosurgery with linear accelerator-based radiosurgery; where appropriate, Cyberknife technology is discussed. Topics covered are: positioning of the head (invasive versus non-invasive positioning systems); collimator construction; beam properties; beam arrangements; treatment planning; and issues regarding manpower (including a discussion of patient repositioning during treatment), machine availability, and financial considerations. PMID:12680787

  7. Endoscopic Submucosal Dissection Using a Novel Versatile Knife: An Animal Feasibility Study (with Video)

    PubMed Central

    Kwon, Chang-Il; Kim, Gwangil; Kim, Won Hee; Ko, Kwang Hyun; Hong, Sung Pyo; Jeong, Seok; Lee, Don Haeng

    2014-01-01

    Background/Aims In order to reduce the procedure time and the number of accessory changes during endoscopic submucosal dissection (ESD), we developed a novel versatile knife, which has the combined advantages of several conventional knives. The aim of this study was to compare the efficacy, safety, and histological quality of ESD performed using this novel versatile knife and a combination of several conventional knives. Methods This was an in vivo animal study comparing two different modalities of ESD in mini-pigs. Completion time of each resection was documented, and the resected specimens were retrieved and evaluated for completeness. To assess the quality control of the procedures and adverse events, detailed histopathological examinations were performed. Results A total of 18 specimens were dissected by ESD safely and easily (nine specimens using the new versatile knife; nine specimens by mixing conventional knives). All resections were completed as en bloc resections. There was no significant difference in procedure time between the 2 modalities (456 seconds vs. 355 seconds, p=0.258) and cutting speed (1.983 mm2/sec vs. 1.57 mm2/sec, p=1.000). The rate of adverse events and histological quality did not statistically differ between the modalities. Conclusions ESD with a versatile knife appeared to be an easy, safe, and technically efficient method. PMID:25505721

  8. Whole-procedure clinical accuracy of Gamma Knife treatments of large lesions

    SciTech Connect

    Ma Lijun; Chuang, Cynthia; Descovich, Martina; Petti, Paula; Smith, Vernon; Verhey, Lynn

    2008-11-15

    The mechanical accuracy of Gamma Knife radiosurgery based on single-isocenter measurement has been established to within 0.3 mm. However, the full delivery accuracy for Gamma Knife treatments of large lesions has only been estimated via the quadrature-sum analysis. In this study, the authors directly measured the whole-procedure accuracy for Gamma Knife treatments of large lesions to examine the validity of such estimation. The measurements were conducted on a head-phantom simulating the whole treatment procedure that included frame placement, computed tomography imaging, treatment planning, and treatment delivery. The results of the measurements were compared with the dose calculations from the treatment planning system. Average agreements of 0.1-1.6 mm for the isodose lines ranging from 25% to 90% of the maximum dose were found despite potentially large contributing uncertainties such as 3-mm imaging resolution, 2-mm dose grid size, 1-mm frame registration, multi-isocenter deliveries, etc. The results of our measurements were found to be significantly smaller (>50%) than the calculated value based on the quadrature-sum analysis. In conclusion, Gamma Knife treatments of large lesions can be delivered much more accurately than predicted from the quadrature-sum analysis of major sources of uncertainties from each step of the delivery chain.

  9. Quantitative phase tomography by using x-ray microscope with Foucault knife-edge scanning filter

    NASA Astrophysics Data System (ADS)

    Watanabe, Norio; Tsuburaya, Yuji; Shimada, Akihiro; Aoki, Sadao

    2016-01-01

    Quantitative phase tomography was evaluated by using a differential phase microscope with a Foucault knife-edge scanning filter. A 3D x-ray phase image of polystyrene beads was obtained at 5.4 keV. The reconstructed refractive index was fairly good agreement with the Henke's tabulated data.

  10. Implementation of a quantitative Foucault knife-edge method by means of isophotometry

    NASA Astrophysics Data System (ADS)

    Zhevlakov, A. P.; Zatsepina, M. E.; Kirillovskii, V. K.

    2014-06-01

    Detailed description of stages of computer processing of the shadowgrams during implementation of a modern quantitative Foucault knife-edge method is presented. The map of wave-front aberrations introduced by errors of an optical surface or a system, along with the results of calculation of the set of required characteristics of image quality, are shown.